JP6936682B2 - Belt offset correction method, belt offset correction device and image forming device - Google Patents

Description

The present invention relates to a belt deviation correction method, a belt deviation correction device, and an image forming apparatus such as a copying machine, a multifunction device, a printer, and a facsimile machine provided with the belt deviation correction device.

Belts wound around the plurality of belt rollers, by variations in components, biased often in a width direction orthogonal to the rotating direction of the belt. Therefore, a means for correcting the deviation of the belt has been conventionally proposed. For example, in Patent Document 1, as a detection unit for detecting the position of the belt in the width direction, a photo sensor is provided at the left and right ends in the width direction of the belt to detect the left side belt, and the right side belt is detected. It is described that two detectors with a photosensor are used (see paragraph [0041] of Patent Document 1). Further, in Patent Document 2, as a detection unit for detecting the position of the belt in the width direction, at least one edge of the belt is sandwiched between a light source and a photodetector, and the light emitted from the light source is blocked by the belt to detect light. It is described that a belt edge sensor that changes the light receiving area of the device is used (see paragraph [0038] of Patent Document 2).

Japanese Unexamined Patent Publication No. 2009-282419 Japanese Unexamined Patent Publication No. 2003-316101

However, in the configuration described in Patent Document 1, since the position in the width direction of the belt is detected by using the two detection units, the configuration is complicated and the cost is high accordingly. Further, in the configuration described in Patent Document 2, the position in the width direction of the belt is detected by using a special detection unit such that the light receiving area changes when the belt blocks the light emitted from the light source, so that the detection unit can be used as a detection unit. It is not possible to use a general-purpose and inexpensive one.

Accordingly, the present invention provides a belt Katayose correction method for correcting the deviation of the wound around belts to a plurality of belt rollers, it is possible to simplify the structure, thereby on can be suppressed to be low cost An object of the present invention is to provide a belt deviation correction method, a belt deviation correction device, and an image forming device, which can use a general-purpose and inexpensive one as a detection unit for detecting a position of a belt in the width direction.

In order to solve the above problems, the following first and second aspects of the belt deviation correction method , the first and second aspects of the belt deviation correction device , and the image forming apparatus are provided.

(1) Belt Katayose correcting method of the first aspect according to the first aspect of the belt Katayose correction method of the present invention is a belt Katayose correction method for correcting the deviation of the wound around belts to a plurality of belt rollers, A single base point detection unit that detects a predetermined base point in the width direction of the belt is used as a detection unit that detects a position in the width direction orthogonal to the circumferential direction of the belt, and in correcting the deviation of the belt. , if the previous SL base detection unit does not detect the base, while the base point in the width direction before moving the belt on the detection side closer to the base point detecting unit, the base point detecting unit said base point when detecting, the base point to move the belt to the non-detection side moving away from the base point detecting portion opposite to the said detection side, of the belt correcting roller for moving the belt in the width direction By swinging the belt at a predetermined swing speed so as to be tiltable with respect to the circumferential axis, the belt is moved in the width direction, and from the detection time when the base point detection unit detects the base point to the non-detection time when the base point is not detected. The detection time and the non-detection time from the non-detection time to the detection time are measured, and the inclination range of the correction roller is set so that the time difference between the detection time and the non-detection time falls within a predetermined time range. is shifted, the correction roller is swung at a predetermined oscillation speed range, when shifting the tilt range of the correction roller, the Rukoto swung the correction roller at the maximum speed of the swing speed range It is a feature.
(2) Belt offset correction method of the second aspect
The belt deviation correction method of the second aspect according to the present invention is a belt deviation correction method for correcting the deviation of the belt wound around a plurality of belt rollers, and the position in the width direction orthogonal to the circumferential direction of the belt. As a detection unit for detecting, a single base point detection unit that detects a predetermined base point in the width direction of the belt is used, and the base point detection unit detects the base point when correcting the deviation of the belt. If not, the belt is moved to the detection side where the base point approaches the base point detection unit in the width direction, while when the base point detection unit detects the base point, the base point is the detection side. The belt is moved to the non-detection side away from the base point detection unit on the opposite side, and the correction roller for moving the belt in the width direction can be tilted with respect to the circumferential axis of the belt at a predetermined swing speed. By swinging, the belt is moved in the width direction, and the detection time from the detection time when the base point detection unit detects the base point to the non-detection time when the base point is not detected, and from the non-detection time to the detection time. The non-detection time is measured, the inclination range of the correction roller is shifted so that the time difference between the detection time and the non-detection time falls within a predetermined time range, and the correction roller is swung at a plurality of steps. When swinging and correcting the deviation of the belt, if there is no change in the detection of the base point by the base point detection unit even if the predetermined reference elapsed time is exceeded, the step of the swing speed of the correction roller is set. It is characterized in that when the base point detection unit changes the detection of the base point, the step of the swing speed of the correction roller is lowered.

(3) Belt Katayose correcting device of the first embodiment according to the first aspect of the belt Katayose correction device the present invention is a belt Katayose correcting device for correcting a deviation of belts wound around a plurality of belt rollers, comprises a single base detection unit for detecting a predetermined reference point in the width direction orthogonal to the rotating direction of the belt, when correcting the offset of the belt, if the previous SL base detection unit does not detect the base point the while the base point in the width direction Before moving the belt on the detection side closer to the base point detecting unit, when the base point detecting unit detects the base point, opposite to the base point the detecting side The belt is moved to the non-detection side away from the base point detection unit on the side, and the correction roller for moving the belt in the width direction is shaken at a predetermined swing speed so as to be tiltable with respect to the circumferential axis of the belt. By moving the belt, the belt is moved in the width direction, and the detection time from the detection time when the base point detection unit detects the base point to the non-detection time when the base point is not detected and the non-detection time from the non-detection time to the detection time. The detection time is measured, the inclination range of the correction roller is shifted so that the time difference between the detection time and the non-detection time falls within a predetermined time range, and the correction roller is shaken within a predetermined swing speed range. is moving, when shifting the tilt range of the correction roller is characterized Rukoto swung the correction roller at the maximum speed of the swing speed range.
(4) Belt offset correction device of the second aspect
The belt deviation correction device of the second aspect according to the present invention is a belt deviation correction device that corrects the deviation of the belt wound around a plurality of belt rollers, and is predetermined in the width direction orthogonal to the circumferential direction of the belt. A single base point detecting unit for detecting the base point of the belt is provided, and when the base point detecting unit does not detect the base point when correcting the deviation of the belt, the base point detects the base point in the width direction. While the belt is moved to the detection side approaching the unit, when the base point detection unit detects the base point, the belt is moved to the non-detection side where the base point is away from the base point detection unit on the side opposite to the detection side. The belt is moved in the width direction by swinging the correction roller for moving the belt in the width direction at a predetermined swing speed so as to be tiltable with respect to the circumferential axis of the belt. The detection time from the detection time when the base point detection unit detects the base point to the non-detection time when the base point is not detected and the non-detection time from the non-detection time to the detection time are measured, and the detection time and the non-detection time are measured. When the inclination range of the correction roller is shifted so that the time difference from the time falls within a predetermined time range, the correction roller is oscillated at a plurality of swing speeds, and the deviation of the belt is corrected. If there is no change in the detection of the base point by the base point detection unit even after the predetermined reference elapsed time is exceeded, the stage of the swing speed of the correction roller is increased, and the detection change of the base point by the base point detection unit is performed. In some cases, it is characterized in that the step of the swing speed of the correction roller is lowered.

( 5 ) Image Forming Device An image forming device comprising the belt offset correction device of the first aspect or the second aspect according to the present invention.

According to the present invention, the configuration can be simplified, thereby keeping the cost low, and it becomes possible to use a general-purpose and inexpensive detection unit for detecting the position of the belt in the width direction. ..

It is schematic cross-sectional view of the image forming apparatus provided with the belt offset correction apparatus which carries out the belt offset correction method which concerns on embodiment of this invention, as seen from the front. It is a schematic front view which shows the fixing device shown in FIG. It is a schematic plan view which shows the fixing device shown in FIG. It is a schematic front view which shows the operation mechanism, the drive transmission mechanism and the drive part in the fixing device shown in FIG. It is the schematic cross-sectional view which shows the 1st cam and the 1st engaging part part in the actuating mechanism shown in FIG. 4 in an enlarged manner. It is the schematic cross-sectional view which shows the 2nd cam and the 2nd engaging part part in the actuating mechanism shown in FIG. 4 in an enlarged manner. It is the schematic perspective view which looked at the actuating mechanism shown in FIG. 4 from obliquely above toward the other side. FIG. 6 is a schematic perspective view of the operating mechanism shown in FIG. 4 viewed from diagonally above with one side portion in the width direction facing one side. It is a figure which shows the detachable member which comprises the actuated member in the actuating mechanism shown in FIG. be. FIG. 6 is a schematic perspective view of a first cam and a second cam provided on a rotation shaft on one side of the operating mechanism shown in FIG. 4 as viewed from diagonally above toward one side. FIG. 4 is a diagram showing a state in which one side of the pressure roller is tilted so as to move in one direction in the swing direction in a pressure contact state of the pressure roller with the fixing roller in the operating mechanism shown in FIG. 4 (a). Is a schematic front view of the first cam and the first engaging portion portion, and (b) is a schematic cross-sectional view of the second cam and the second engaging portion portion. 11 is an enlarged view showing an operating state of the operating mechanism shown in FIG. 11, and FIG. 11A is a schematic front view showing an enlarged view of a first cam and a first engaging portion shown in FIG. 11A. (B) is a schematic cross-sectional view showing an enlarged view of the second cam and the second engaging portion shown in FIG. 11 (b). FIG. 4 is a view showing a state in which one side of the pressure roller is tilted so as to move in the other direction in the swing direction in the state of pressure contact of the pressure roller with the fixing roller in the operation mechanism shown in FIG. 4 (a). Is a schematic front view of the first cam and the first engaging portion portion, and (b) is a schematic cross-sectional view of the second cam and the second engaging portion portion. 13 is an enlarged view showing an operating state of the operating mechanism shown in FIG. 13, and FIG. 13A is a schematic front view showing an enlarged view of a first cam and a first engaging portion shown in FIG. 13A. (B) is a schematic cross-sectional view showing an enlarged view of the second cam and the second engaging portion shown in FIG. 13 (b). 4A and 4B are views showing a state in which the pressure roller is parallel to the fixing roller in a pressure contact state of the pressure roller to the fixing roller in the operating mechanism shown in FIG. 4, and FIG. 4A shows a first cam and a first cam. 1 is a schematic front view of the engaging portion portion, and FIG. 3B is a schematic cross-sectional view of the second cam and the second engaging portion portion. FIG. 15 is an enlarged view showing an operating state of the operating mechanism shown in FIG. 15, and FIG. 15A is a schematic front view showing an enlarged view of a first cam and a first engaging portion shown in FIG. 15A. (B) is a schematic cross-sectional view showing an enlarged view of the second cam and the second engaging portion shown in FIG. 15 (b). It is a system block diagram which shows the schematic structure of the control system in the image forming apparatus which concerns on this embodiment. It is a flowchart which shows an example of the belt deviation correction control by a control part. It is a graph for demonstrating the inconvenience when correcting the deviation of a fixing belt, and (a) shows the state which the inclination range of a pressure roller by an actuating mechanism is balanced in the width direction, and (a) b) shows a state in which the tilting range of the pressurizing roller by the operating mechanism is shifted to the detection side, and (c) is a state in which the tilting range of the pressurizing roller by the operating mechanism is shifted to the non-detection side. Indicates the state. It is explanatory drawing for demonstrating the inclination range shift mechanism, (a) is the schematic perspective view which looked at the locking part from diagonally above on the back side, (b) is the front side of the locking part. It is a schematic perspective view seen from obliquely above, FIG. 3C is a schematic rear view showing an opening in the detachable member of the actuated member, and FIG. It is a schematic rear view which shows the inserted state. It is a chart showing the formulas (1) and (2) of the calculation formula used when adjusting the shift amount of the inclination range of the pressure roller and the adjustment table, and (a) is the formula (1) of the calculation formula. ) Is used as the detection time, and (b) shows the case where the molecule of the formula (2) is the non-detection time. It is a flowchart which shows another example of the belt deviation correction control by a control part.

Hereinafter, embodiments according to the present invention will be described with reference to the drawings. In the following description, the same parts are designated by the same reference numerals. Their names and functions are the same. Therefore, the detailed description of them will not be repeated.

[Overall configuration of image forming apparatus]
FIG. 1 is a schematic cross-sectional view of an image forming apparatus 200 including a belt offset correction device 300 that implements the belt offset correction method according to the embodiment of the present invention, as viewed from the front. In FIG. 1, reference numeral X indicates a width direction (depth direction), reference numeral Y indicates a left-right direction Y orthogonal to the width direction X, and reference numeral Z indicates a vertical direction. This also applies to FIGS. 2 to 16 described later.

The image forming apparatus 200 shown in FIG. 1 uses an electrophotographic method for multicoloring on a sheet P such as recording paper according to the image data read by the document reading apparatus 208 or the image data transmitted from the outside. It is a color image forming apparatus that forms a monochromatic image. The image forming apparatus 200 may be a monochrome image forming apparatus. Further, the image forming apparatus 200 may be a color image forming apparatus of another form.

The image forming apparatus 200 includes a document reading apparatus 208 and an image forming apparatus main body 210, and the image forming apparatus main body 210 is provided with an image forming unit 202 and a sheet conveying system 203.

The image forming unit 202 includes an exposure device 1 (specifically, an exposure unit of a writing optical system), a plurality of developing devices 2 and 2 (specifically, a developing unit), a plurality of photoconductor drums 3 to 3, and a plurality of photosensitizers. Body cleaners 4-4, multiple chargers 5-5, primary transfer belt device 6 (specifically, primary transfer belt unit), multiple toner cartridge devices 21-21 (specifically, toner cartridge unit) And a fixing device 17 (specifically, a fixing unit) is provided. Further, the sheet transport system 203 includes a paper feed tray 81, a manual paper feed tray 82, and a discharge tray 15.

An image reading device 92 made of transparent glass on which a document (not shown) is placed is provided on the upper part of the image forming apparatus main body 210, and an image reading device for reading an image of the document is provided on the lower part of the document placing table 92. 90 is provided. A document reading device 208 is provided on the upper side of the document mounting table 92. The image of the original document read by the document reading device 208 is sent to the image forming apparatus main body 210 as image data, and the image formed based on the image data in the image forming apparatus main body 210 is recorded on the sheet P.

The image data handled by the image forming apparatus 200 corresponds to a color image using a plurality of colors (in this example, each color of black (K), cyan (C), magenta (M), and yellow (Y)). .. Therefore, there are a plurality of types of developing devices 2 to 2, photoconductor drums 3 to 3, photoconductor cleaners 4 to 4, chargers 5 to 5, and toner cartridge devices 21 to 21 (4 types in this example). Each is set to a plurality (4 each in this example, black, cyan, magenta, and yellow, respectively) so as to form the image of, and a plurality of (4 in this example) image stations are configured by these. There is.

In the image forming apparatus 200, when forming an image, the sheet P is supplied from the paper feed tray 81 or the manual paper feed tray 82, and the sheets up to the resist roller 13 are supplied by the transport rollers 12a to 12a provided along the sheet transport path S. Transport P. Next, the sheet P is conveyed by the secondary transfer belt device 10 at the timing of matching the toner images on the primary transfer belt 61 that is orbitably moved in the circumferential direction M between the sheet P and the primary transfer belt device 6, and the sheet P is conveyed. Transfer the toner image onto it. After that, the unfixed toner on the sheet P is melted and fixed by heat by passing the sheet P between the fixing roller 171 and the pressure roller 172 in the fixing device 17, and the unfixed toner on the sheet P is melted and fixed by heat, and passes through the transport roller 12a and the discharge roller portion 31. Discharge onto the discharge tray 15. Further, in the image forming apparatus 200, when forming an image not only on the front surface of the sheet P but also on the back surface, the sheet P is conveyed in the reverse direction from the discharge roller portion 31 to the reversing path Sr, and the sheet P is conveyed through the conveying roller 12b. The front and back surfaces of P are inverted and guided to the resist roller 13 again, and the toner image is fixed on the back surface of the sheet P in the same manner as the front surface of the sheet P and discharged to the discharge tray 15. In this way, the image forming apparatus 200 completes a series of printing operations.

It is also possible to form a monochrome image using at least one of the four image forming stations and transfer the monochrome image to the primary transfer belt 61 of the primary transfer belt device 6. Like the color image, this monochrome image is also transferred from the primary transfer belt 61 to the sheet P and fixed on the sheet P.

<Fixing device>
Next, an example in which the belt offset correction device 300 according to the present embodiment is applied to the belt fixing type fixing device 17 will be described below.

The fixing device 17 includes a plurality of belt rollers (fixing roller 171 and heating roller 174 in this example) and an endless belt wound around the plurality of belt rollers (fixing belt 173 in this example). The fixing belt 173 can transfer heat from the heating roller 174 to the fixing roller 171. In the fixing device 17, the pressure roller 172 is pressed against the fixing roller 171 via the fixing belt 173. Further, the fixing belt 173 is heated by a heat source 178 provided inside the heating roller 174, and is maintained at a predetermined fixing temperature based on a signal from the temperature detecting means 177 (specifically, a temperature sensor such as a thermistor). It has become like.

2 and 3 are a schematic front view and a schematic plan view showing the fixing device 17 shown in FIG. 1, respectively. Further, FIG. 4 is a schematic front view showing the operating mechanism 100, the drive transmission mechanism 180, and the drive unit 190 in the fixing device 17 shown in FIG. FIG. 4 shows a state in which the pressure roller 172 is released from pressure contact with the fixing roller 171. In addition, in FIGS. 2 and 3, some components and the like of the fixing device 17 shown in FIG. 4 are not shown. Further, in FIG. 4, the configuration of the other side (back side in this example) is the other side (back side in this example) except for the configuration in which the pressure roller 172 is swung in the swing direction W, as will be described later. ) Is substantially the same as the configuration of), and the illustration is omitted here. This also applies to FIGS. 5, 6, 8, and 10 to 16 described later.

In the present embodiment, the fixing device 17 is in a state where the fixing roller 171 and the pressure roller 172 are mutually pressed by an urging member 175 (in this example, a pressure welding spring such as a coil spring) with the fixing belt 173 in between. , A fixing nip area N (an example of a nip portion) is formed between the fixing belt 173 and the pressure roller 172. The fixing device 17 further includes an operating mechanism 100. As will be described later, the operating mechanism 100 acts as a means for performing pressure contact, pressure adjustment, and pressure contact release of the pressure roller 172 with respect to the fixing roller 171, and corrects the deviation of the fixing belt 173 by swinging the pressure roller 172. Act as a means Act as a means. The operating mechanism 100 will be described in detail later.

In the fixing roller 171, the rotating shaft 171a is rotatably provided on the main body (specifically, the main body frame FL) of the fixing device 17 via bearings 171b and 171b. The fixing roller 171 sandwiches the fixing belt 173 together with the pressure roller 172, and faces the unfixed toner image T on the sheet P between the fixing belt 173 and the pressure roller 172, and the unfixed toner image T. To fix. The fixing roller 171 has an elastic layer 171c made of a rubber member such as silicone rubber. In the pressure roller 172, a rotating shaft 172a is rotatably provided on the actuated member 110 (specifically, the main body member 110a) via bearings 110d and 110d. The pressure roller 172 has an elastic layer 172b made of a rubber member such as silicone rubber. The fixing belt 173 is provided with an elastic layer (not shown) made of a rubber member such as silicone rubber on a base material (not shown) made of a metal such as nickel. Further, in the heating roller 174, the rotating shaft 174a is rotatably provided on the main body (specifically, the main body frame FL) of the fixing device 17 via the bearing 174b. The heating roller 174 includes a heat source 178 such as a halogen heater, and is heated by the heat source 178 to heat the fixing belt 173 via the heating roller 174. The heating roller 174 includes a cylindrical core metal. Inside the heating roller 174, a heat source 178 for heating the heating roller 174 is provided. As a result, the heating roller 174 is heated by the heat source 178, and the heat of the heating roller 174 is conducted to the fixing belt 173 to heat the fixing belt 173. The heating roller 174 has a metal raw tube 174c such as aluminum.

In the fixing device 17 described above, the rotational driving force from the operating mechanism (not shown) on the image forming device main body 210 side is fixed via the gear (not shown) in the state of being mounted on the image forming device main body 210. The fixing roller 171 is rotationally driven in a predetermined rotation direction E1 by being transmitted to the rotation shaft 171a of the roller 171. As the fixing roller 171 rotates, the fixing belt 173 orbits in the same circumferential direction E as the rotation direction E1 of the fixing roller 171, the heating roller 174 rotates in the rotation direction E1, and the pressure roller 172 is further fixed. The roller 171 is driven to rotate in the direction E2 opposite to the rotation direction E1. Then, the sheet P to which the unfixed toner image T is formed and is conveyed in the sheet conveying direction H is received, the sheet P is sandwiched between the fixing belt 173 and the pressure roller 172 and conveyed, and the sheet P is conveyed in the fixing nip area N. Heat and pressurize.

Even if the fixing device 17 is arranged inside or outside the fixing belt 173 and includes a tension roller that presses the fixing belt 173 to the outside or the inside so as to apply the tension force of the fixing belt 173. good. The fixing device 17 includes, in place of or in addition to the tension roller, an urging member (for example, a coil spring) that applies urging force to both ends of the rotating shaft 174a of the heating roller 174 to the side opposite to the fixing roller 171. You may. Further, the fixing roller 171 and / or the pressure roller 172 may be provided with a heat source 178. When a tension roller is provided, the tension roller may be provided with a heat source 178. Further, when the fixing belt 173 is further wound around another roller, a heat source 178 may be provided on at least one of the other rollers.

<Operating mechanism>
In the present embodiment, the operating mechanism 100 drives the first engaging portion 111 and the second engaging portion 112, and has a single rotary shaft 120 (specifically, a rotary drive shaft) and a first rotary shaft 120. A cam 131 and a second cam 132 (an example of a swing cam) are provided.

A driving force is transmitted from a single driving unit 190 (specifically, a rotational driving source) to the single rotating shaft 120. The first cam 131 and the second cam 132 operate the first engaging portion 111 and the second engaging portion 112 by a driving force from a single rotating shaft 120, respectively.

FIG. 5 is a schematic cross-sectional view showing an enlarged view of the first cam 131 and the first engaging portion 111 portion of the operating mechanism 100 shown in FIG. FIG. 6 is a schematic cross-sectional view showing an enlarged view of the second cam 132 and the second engaging portion 112 portion of the operating mechanism 100 shown in FIG. FIG. 7 is a schematic perspective view of the operating mechanism 100 shown in FIG. 4 viewed from diagonally above toward the other side (back side in this example). FIG. 8 is a schematic perspective view of the operating mechanism 100 shown in FIG. 4 viewed from diagonally above with one side (front side in this example) of the operating mechanism 100 in the width direction X facing one side.

FIG. 9 is a diagram showing a detachable member 110b constituting the actuated member 110 in the actuating mechanism 100 shown in FIG. 9 (a) and 9 (b) are a schematic front view and a schematic rear view of the detachable member 110b constituting the actuated member 110, respectively.

FIG. 10 is a schematic perspective view of the first cam 131 and the second cam 132 provided on the rotating shaft 120 on one side of the operating mechanism 100 shown in FIG. 4 as viewed obliquely from above toward one side.

FIG. 11 shows a state in which one side of the pressure roller 172 is inclined so as to move in one direction W1 in the swing direction W in the state of pressure contact of the pressure roller 172 with the fixing roller 171 in the operating mechanism 100 shown in FIG. It is a figure which shows. FIG. 11A is a schematic front view of the first cam 131 and the first engaging portion 111 portion, and FIG. 11B is a schematic cross-sectional view of the second cam 132 and the second engaging portion 112 portion. be. FIG. 12 is an enlarged view showing an operating state of the operating mechanism 100 shown in FIG. 12 (a) is a schematic front view showing an enlarged view of the first cam 131 and the first engaging portion 111 shown in FIG. 11 (a), and FIG. 12 (b) is shown in FIG. 11 (b). It is the schematic sectional drawing which shows the 2nd cam 132 and the 2nd engaging part 112 part enlarged.

FIG. 13 shows a state in which one side of the pressure roller 172 is inclined so as to move in the other direction W2 in the swing direction W in the state of pressure contact of the pressure roller 172 with the fixing roller 171 in the operating mechanism 100 shown in FIG. It is a figure which shows. 13 (a) is a schematic front view of the first cam 131 and the first engaging portion 111 portion, and FIG. 13 (b) is a schematic cross-sectional view of the second cam 132 and the second engaging portion 112 portion. be. FIG. 14 is an enlarged view showing an operating state of the operating mechanism 100 shown in FIG. 14 (a) is a schematic front view showing an enlarged view of the first cam 131 and the first engaging portion 111 shown in FIG. 13 (a), and FIG. 14 (b) is shown in FIG. 13 (b). It is the schematic sectional drawing which shows the 2nd cam 132 and the 2nd engaging part 112 part enlarged.

FIG. 15 is a diagram showing a state in which the pressure roller 172 is parallel to the fixing roller 171 in a pressure contact state of the pressure roller 172 to the fixing roller 171 in the operating mechanism 100 shown in FIG. FIG. 15A is a schematic front view of the first cam 131 and the first engaging portion 111 portion, and FIG. 15B is a schematic cross-sectional view of the second cam 132 and the second engaging portion 112 portion. be. FIG. 16 is an enlarged view showing an operating state of the operating mechanism 100 shown in FIG. 16 (a) is a schematic front view showing an enlarged view of the first cam 131 and the first engaging portion 111 shown in FIG. 15 (a), and FIG. 16 (b) is shown in FIG. 15 (b). It is the schematic sectional drawing which shows the 2nd cam 132 and the 2nd engaging part 112 part enlarged.

In addition, in FIG. 11 (b), FIG. 13 (b) and FIG. 15 (b), the fixing roller 171 and the pressure roller 172, the fixing belt 173 and the like are not shown.

Further, FIG. 17 is a system block diagram showing a schematic configuration of a control system in the image forming apparatus 200 according to the present embodiment.

In the present embodiment, the first cam 131 has an operating state maintaining region γ1a for maintaining the operating state of the first engaging portion 111. The second cam 132 has an operating state change region γ2b that changes the operating state of the second engaging portion 112. Then, when the operating state of one operation (roller pressure welding operation in this example) with respect to the first engaging portion 111 is maintained in the operating state maintaining region γ1a of the first cam 131, the operating state changing region of the second cam 132 is changed. γ2b is configured to change the operating state of the belt offset correction operation with respect to the second engaging portion 112. The operating mechanism 100 changes the operating state of the roller pressure welding operation to the first engaging portion 111 in the operating state changing region γ1b of the first cam 131, and the belt to the second engaging portion 112 by the second cam 132. It is configured so that the offset correction operation is not performed. The first cam 131 and the second cam 132 are rotated so that, for example, the phase in which the diameter r1 of the first cam 131 is displaced and the phase in which the diameter (radius r2) of the second cam 132 is displaced do not match (shift). It is provided on the shaft 120. The actuating mechanism 100 further includes a actuated member 110 (specifically, a support member, in this example, a pressurizing lever) provided with a first engaging portion 111 and a second engaging portion 112. The first cam 131 reciprocates the actuated member 110 in one reciprocating movement direction (rotation direction V in this example) at the first engaging portion 111. The second cam 132 reciprocates the actuated member 110 at the second engaging portion 112 in a reciprocating movement direction (in this example, the swing direction W) different from the rotation direction V. One reciprocating movement direction includes a rotation direction V that rotates around a rotation axis β4 that is parallel or substantially parallel to the rotation axis β3 direction (width direction X in this example) of the rotation axis 120. The other reciprocating movement direction includes a swing direction W that swings around the swing axis β5 that intersects (specifically, orthogonally or substantially orthogonally) the rotation axis β4. The actuated member 110 is configured to be rotatable in the rotation direction V and swingable in the swing direction W. By doing so, the actuated member 110 can be rotated in the rotation direction V and can be swung in the swing direction W. As a result, the actuated member 110 can be moved in a plurality of directions different from each other. The actuated member 110 is a main body member 110a provided with a first engaging portion 111 and a detachable member 110b provided with a second engaging portion 112 detachably provided on the main body member 110a (in this example, a swing guide). And have. The actuated member 110 is a pair of actuated members 110, 110 located on both sides of the rotating shaft 120.

By the way, when the actuated member 110 is a pair of actuated members 110, 110 located on both sides of the rotating shaft 120, if a single cam is used as the first cam 131, the pair of actuated members 110, 110 It becomes difficult to reliably reciprocate the cams in the same direction in the rotation direction V. In this respect, in the present embodiment, the first cam 131 is a pair of first cams 131, 131 provided on both sides of the rotation shaft 120, and a pair when the rotation shaft 120 is rotationally driven around the rotation axis β3. The actuated members 110 and 110 are reciprocated in the same direction in the rotation direction V, respectively. By doing so, when the rotary shaft 120 is rotationally driven around the rotary axis β3 by the pair of first cams 131 and 131 provided on both sides of the rotary shaft 120, the pair of actuated members 110 and 110 are rotated in the rotational directions, respectively. It can be reliably reciprocated in the same direction at V. As a result, the first engaging portions 111, 111 of the pair of members to be operated 110, 110 can be reliably operated in the same direction in the rotation direction V on both sides of the rotation shaft 120. In this case, in the pair of members to be operated 110, 110, at least the portions that abut with the first engaging portions 111, 111 have the same or substantially the same shape, and the pair of the first cams 131, 131 have the same or substantially the same shape, and the pair. The phases in which the diameters r1 and r1 of the first cams 131 and 131 are displaced can be the same or substantially the same phase.

By the way, when the actuated member 110 is a pair of actuated members 110, 110 located on both sides of the rotating shaft 120, a single cam may be used as the second cam 132, or the pair of cams may be used. You may use it. In the present embodiment, the second cam 132 is a single second cam 132 provided on any one side (front side in this example) of the rotating shaft 120. Of the pair of members 110 and 110 to be operated, the member 110 to be operated on the side where the single second cam 132 is provided (the front side in this example) is reciprocated in the swing direction W. By doing so, even if a single second cam 132 provided on any one side of the rotating shaft 120 is used, the single second cam 132 causes a single second of the pair of actuated members 110, 110. The actuated member 110 on the 2 cam 132 side can be reliably reciprocated in the swing direction W, whereby the second engaging portion 112 of the actuated member 110 is moved in the swing direction W on one side of the rotating shaft 120. It can be operated without any trouble.

Although not shown here, in the present embodiment, the second cam 132 is a pair of second cams 132 and 132 provided on both sides of the rotating shaft 120, and the rotating shaft 120 is rotated around the rotation axis β3. The pair of actuated members 110 and 110 may be reciprocated in opposite directions W1 and W2 in the swing direction W when the driven members are rotationally driven. In other words, in the pair of second cams 132 and 132, one second cam 132 moves one acted member 110 in one direction W1 in the swing direction W, and the other second cam 132 is the other. The actuated member 110 is moved in the other direction W2 in the swing direction W. Further, a pair of second cams 132 and 132 and one second cam 132 move one acted member 110 to the other direction W2 in the swing direction W, and the other second cam 132 is actuated by the other. The member 110 is moved in one direction W1 in the swing direction W. By doing so, when the rotary shaft 120 is rotationally driven around the rotary axis β3 by the pair of second cams 132 and 132 provided on both sides of the rotary shaft 120, the pair of actuated members 110 and 110 are swung in the swing direction, respectively. It can be reliably reciprocated in the opposite directions W1 and W2 in W. As a result, the second engaging portions 112 of the pair of members to be operated 110 and 110 can be reliably operated in the opposite directions W1 and W2 in the swing direction W on both sides of the rotating shaft 120. In this case, the portion of the pair of members to be operated 110 and 110 that abuts at least the second engaging portion 112 has the same shape, the pair of second cams 132 and 132 have the same or substantially the same shape, and the pair of second cams 132. The phases in which the diameters of, 132 are displaced can be different from each other.

In the present embodiment, the first cam 131 performs a roller pressure contact operation of pressing the pressure roller 172 against the fixing roller 171, and the second cam 132 performs a belt deviation correction operation for correcting the deviation of the fixing belt 173. It is configured in. By doing so, the roller pressure welding operation and the belt offset correction operation can be preferably performed.

<Detailed configuration of operating mechanism>
Next, the detailed configuration of the operating mechanism 100 according to the present embodiment will be specifically described below.

The operating mechanism 100 is configured to sandwich and convey the fixing belt 173 while rotating each other in a state where the fixing rollers 171 and the pressure rollers 172 facing each other are in pressure contact with each other. The operating mechanism 100 makes the pressure roller 172 rotatable around the axis of the fixing roller 171 and moves the rotation axes β1 and β2 of the fixing roller 171 and the pressure roller 172 away from each other in one direction V1 and close to each other in the other direction V2. The actuated member 110 that supports the movable member 110 is provided. The actuated member 110 is rotatably supported by the fixing roller 171 around the rotation axis β4 which is parallel to or substantially parallel to the rotation axis β2 of the pressure roller 172.

In this example, the actuated member 110 supports the pressure roller 172 so that the pressure roller 172 rotates in one direction V1 and the other direction V2 with respect to the fixing roller 171. The operating mechanism 100 presses the pressurizing roller 172 via the actuated member 110 toward the fixing roller 171 by the urging member 175 to adjust the pressure, and further presses the pressure roller 172 with respect to the fixing roller 171 via the actuated member 110. The pressure contact of the pressure roller 172 is released. The actuated member 110 (specifically, the main body member 110a) rotatably supports the rotation shaft 172a of the pressure roller 172, and is a rotation support shaft parallel to or substantially parallel to the rotation shaft 172a of the pressure roller 172. It is rotatably provided around the rotation axis β4 of 113 (specifically, the rotation pin). The actuated member 110 is a pair of actuated members 110, 110 provided along a direction orthogonal to or substantially orthogonal to the rotation axis 172a of the pressurizing roller 172 on the outside of both ends in the width direction X of the pressurizing roller 172. (In this example, the actuated plate, specifically the support plate). The pair of actuated members 110 and 110 have recesses 110c and 110c on the sides of the pressure roller 172 facing the rotating shafts 172a and 172a, and are added to the recesses 110c and 110c via bearings 110d and 110d, respectively. Both rotating shafts 172a and 172a of the pressure roller 172 are rotatably supported. In the pair of members to be operated 110, 110, the peripheral portion of the pressure roller 172 between the rotation axis β1 of the fixing roller 171 and the rotation axis β2 of the pressure roller 172 (in the example shown in FIG. 4, diagonally to the left of the pressure roller 172). On the lower side), through elongated holes 110e and 110e penetrating along the rotation axis β4 direction are provided. The through elongated holes 110e and 110e extend in the swing direction W or substantially the swing direction W. The rotary support shaft 113 is rotatably supported by the main body (specifically, the main body frame FL) of the fixing device 17. The through elongated holes 110e and 110e are movably locked to the rotation support shaft 113 along the swing direction W. As a result, the pair of actuated members 110, 110 can be configured to be rotatable in the rotation direction V and swingable in the swing direction W.

Here, the swing direction W is a direction around the swing axis β5 that is orthogonal or substantially orthogonal to the rotation axis β4, but in this example, the swing axis β5 is orthogonal or substantially orthogonal to the rotation axis β4. And, an axis passing through the rotation axis β1 of the fixing roller 171 or its vicinity and the rotation axis β2 of the pressure roller 172 or its vicinity [more specifically, one side end or the center of the rotation axis β2 of the pressure roller 172 or Axis located approximately in the center (in this example, the rear end)]. By doing so, the pressure roller 172 can be swung in the twisting direction with respect to the fixing roller 171. The rocking direction W passes through the rotating axis β2 or its vicinity, and is orthogonal to or substantially orthogonal to both the rocking axis β5 and the rotating axis β2 (more specifically, the pressurizing roller 172). It may be in a direction of swinging around (one end of the rotation axis β2 or an axis located at the center or substantially the center). In this case, the pressure roller 172 swings with respect to the fixing roller 171 so that the fixing pressure differs between one side and the other side of the rotation axis β2, but the amount of inclination of the pressure roller 172 is very small. Deterioration of fixability can be at an acceptable level. Further, in any case, since the fixing roller 171 receives the drive from one side end portion (rear side end portion in this example) of the rotation axis β1, the drive transmission mechanism 180 is attached to one side end portion of the rotation axis β1 of the fixing roller 171. It is effective that the swing axis β5 is located at the side end portion where the drive transmission mechanism 180 of the pressurizing roller 172 is provided.

Further, the through elongated holes 110e and 110e further have an open portion 110e1 open to the outside (downward in this example). As a result, the pair of actuated members 110 and 110 can be easily and easily attached to and detached from the rotary support shaft 113, and the workability of attaching the pair of actuated members 110 and 110 to the rotary support shaft 113 is improved. Can be made to.

Specifically, the through elongated holes 110e and 110e have a U-shape with an open end on the side opposite to the pressure roller 172 side. The rotary support shaft 113 has a shape corresponding to the through elongated holes 110e and 110e (in this example, an oval shape). Through elongated holes 110f and 110f penetrating along the rotation axis β3 direction are provided at positions corresponding to the rotation axis 120 in the pair of actuated members 110 and 110 (main body member 110a and attachment / detachment member 110b in this example). There is. The through elongated holes 110f and 110f extend in the rotation direction V or substantially in the rotation direction V. Through the elongated holes 110f and 110f, the rotating shaft 120 is inserted. As a result, the rotation shaft 120 can be reciprocated in the rotation direction V or substantially in the rotation direction V. Further, the through elongated holes 110f and 110f further have an opening portion 110f1 that is open to the outside (upper in this example). As a result, the rotating shaft 120 can be easily and easily attached to and detached from the through elongated holes 110f and 110f, and the workability of attaching the rotating shaft 120 to the through elongated holes 110f and 110f can be improved.

Specifically, the through elongated holes 110f and 110f have a U-shape with an open end on the side opposite to the first engaging portion 111 side. Further, in the pair of members to be operated 110 and 110, the end portion on the side opposite to the rotation support shaft 113 with the pressurizing roller 172 in between (the diagonally upper right side of the pressurizing roller 172 in FIG. 4, the upper portion of the detachable member 110b). ) Are provided with locking portions 110 g and 110 g (for example, a mounting boss). In the pair of urging members 175 and 175, one end portions 175a and 175a are locked to the locking portions 110g and 110g, while the other end portions 175b and 175b are the main body of the fixing device 17 (specifically, the main body frame FL, It is locked to the locking portions FLa and FLa of FL). The detachable member 110b is movably fixed to the main body member 110a on one side of the pair of members to be operated 110, 110 in the swing direction W or the swing direction W side direction (in this example, the swing direction W side direction). ing. In this example, as shown in FIG. 8, the detachable member 110b is provided with an elongated hole 110b1 along the swing direction W or the swing direction W side direction (in this example, the swing direction W side direction). The main body member 110a is provided with a female hole 110a1 corresponding to the elongated hole 110b1. The detachable member 110b is fixed to the main body member 110a by screwing fixing members SC, SC such as screws from the inside in the direction of the rotation axis β3 into the female hole 110a1 via the elongated hole 110b1.

(1st cam and 1st engaging part)
The pair of first cams 131, 131 are provided at both ends of the rotating shaft 120. The operating state maintenance regions γ1a and γ1a of the pair of first cams 131 and 131 are regions in which the diameter r1 is constant or substantially constant in the circumferential direction of the pair of first cams 131 and 131. The operating state change regions γ1b and γ1b in the pair of first cams 131 and 131 are regions in which the diameter r1 gradually increases or decreases in the circumferential direction of the pair of first cams 131 and 131. The first engaging portions 111 and 111 each have a contact portion 111a that comes into contact with the pair of first cams 131 and 131. In this example, the first engaging portions 111 and 111 have a cylindrical shape. The first engaging portions 111 and 111 come into contact with the pair of first cams 131 and 131 at the contact portions 111a on the outer peripheral surface of the cylindrical shape.

Specifically, the pair of first cams 131, 131 is separate from the rotating shaft 120 and is fixed to the rotating shaft 120. The first engaging portions 111 and 111 form a ball bearing in which the outer rings 111b and 111b rotate around the rotation axis β6 which is parallel to or substantially parallel to the rotation axis β3 direction of the rotation shaft 120. The first engaging portions 111 and 111 are the first engaging portions of the operating state maintaining regions γ1a and γ1a in the pair of first cams 131 and 131, respectively, in the main body members 110a and 110a of the pair of operated members 110 and 110. The pressurizing roller 172 is provided at a position where the pressure roller 172 is in a pressure contact state with the fixing roller 171 at a position where the 111 and 111 are operated. Here, the pressure welding state is a state of a reference fixing pressure as a reference (in this example, a state of the maximum rated pressure for fixing a standard sheet such as standard paper). In addition, the first engaging portions 111 and 111 are the first of the operating state change regions γ1b and γ1b in the pair of first cams 131 and 131 in the main body members 110a and 110a of the pair of actuated members 110 and 110, respectively. The pressurizing roller 172 is provided at a position where the engaging portions 111 and 111 are operated and is in a pressure adjusting state and / or a pressure contact releasing state with respect to the fixing roller 171. Here, the pressure adjustment state is a state of a low fixing pressure adjusted to be lower than the reference fixing pressure (in this example, a state of the minimum rated pressure for fixing a thick sheet such as an envelope or thick paper), and the pressure welding is released. The state is a state in which no pressure is applied from the pressure roller 172 by the urging member 175 toward the fixing roller 171.

The first cam 131 is configured so that the fixing pressure of the pressurizing roller 172 with respect to the fixing roller 171 is set as the reference fixing pressure at the position where the first engaging portions 111 and 111 of the operating state maintaining regions γ1a and γ1a are operated. ..

Specifically, at the position where the first engaging portions 111, 111 of the operating state maintaining regions γ1a, γ1a in the pair of first cams 131, 131 are operated, the pair of first cams 131, 131 is one in the rotation direction R. Even when rotated in the direction R1 and the other direction R2, the distance d between the contact portion 111a of the first engaging portions 111 and 111 with the pair of first cams 131 and 131 and the rotation axis β3 of the rotation shaft 120 is predetermined. It is configured to maintain the first constant distance (for example, the minimum distance). As a result, the pressure contact state of the pressure roller 172 to the fixing roller 171 can be maintained.

Further, the first cam 131 is configured to adjust the fixing pressure of the pressurizing roller 172 with respect to the fixing roller 171 at the position where the first engaging portions 111 and 111 of the operating state change regions γ1b and γ1b are operated.

Specifically, from the position where the first engaging portions 111 and 111 of the operating state maintaining regions γ1a and γ1a in the pair of first cams 131 and 131 are operated, the first engaging portions 111 of the operating state changing regions γ1b and γ1b, The pair of first cams 131, 131 is rotated in one direction R1 in the rotation direction R toward the position where 111 is operated, and the first engaging portions 111, 111 come into contact with the pair of first cams 131, 131. The distance d between the portion 111a and the rotation axis β3 of the rotation shaft 120 is set to a variable distance (for example, a distance larger than the minimum distance and smaller than the maximum distance). As a result, the pressure roller 172 can be brought into a pressure-adjusted state with respect to the fixing roller 171.

Further, the first cam 131 is configured to release the fixing pressure of the pressurizing roller 172 with respect to the fixing roller 171 at the position where the first engaging portions 111 and 111 of the operating state change regions γ1b and γ1b are operated.

Specifically, from the position where the first engaging portions 111 and 111 of the operating state maintaining regions γ1a and γ1a in the pair of first cams 131 and 131 are operated, the first engaging portions 111 of the operating state changing regions γ1b and γ1b, The pair of first cams 131, 131 is rotated in one direction R1 in the rotation direction R toward the position where 111 is operated, and the first engaging portions 111, 111 come into contact with the pair of first cams 131, 131. The distance d between the portion 111a and the rotation axis β3 of the rotation shaft 120 is set to a predetermined second constant distance (for example, the maximum distance) larger than the first constant distance. As a result, the pressure roller 172 can be brought into a pressure contact release state with respect to the fixing roller 171.

In this example, the first cam 131 adjusts the fixing pressure of the pressurizing roller 172 with respect to the fixing roller 171 to a stepless set pressure. However, the present invention is not limited to this, and the first cam 131 may adjust the fixing pressure between the pressurizing rollers 172 with respect to the fixing roller 171 to a set pressure of one or a plurality of steps.

(2nd cam and 2nd engaging part)
The second cam 132 is provided at one end (front side in this example) of the rotating shaft 120. The operating state change region γ2b in the pair of first cams 131 and 131 is a region in which the diameter (radius r2) gradually increases or decreases in the circumferential direction of the second cam 132. The operating state maintenance region γ2a in the second cam 132 is a region in which the diameter (radius r2) is constant or substantially constant in the circumferential direction of the second cam 132. The second engaging portion 112 has contact portions 112a and 112a that come into contact with the second cam 132. In this example, the second engaging portion 112 has a curved portion 112b (specifically, a U-shaped groove portion) that is curved over substantially half a circumference along the circumferential direction of the second cam 132. The second engaging portion 112 comes into contact with the second cam 132 at the contact portion 112a on the inner peripheral surface of the curved portion 112b. The size between the facing contact portions 112a and 112a of the second engaging portion 112 is slightly larger than the diameter of the second cam 132 (the size is such that the second cam 132 can be smoothly inserted). The contact portion 112a has an extension portion 112a1 extending along the rotation direction V or substantially the rotation direction V. As a result, the second engaging portion 112 can reliably bring the second cam 132 into contact with the contact portion 112a. Further, the second engaging portion 112 further has an open portion 112c whose end portion opposite to the bottom portion of the curved portion 112b is open. As a result, the second cam 132 can be easily and easily attached to and detached from the operated member 110.

Specifically, the second cam 132 is eccentric with a diameter smaller than the diameter of the rotating shaft 120. The second cam 132 is formed by subjecting the rotary shaft 120 to a predetermined process (specifically, by cutting), and is integrally formed with the rotary shaft 120. The second engaging portion 112 operates the second engaging portion 112 of the operating state change region γ2b in the second cam 132 in the detachable member 110b of the actuated member 110 on one side of the pair of actuated members 110 and 110. At the position where the pressure roller 172 is to be moved, one side of the pressurizing roller 172 moves in one direction W1 or the other direction W2 in the swing direction W (in this example, it becomes higher or lower) with respect to the fixing roller 171. It is provided in the following position.

The amount of inclination of the pressure roller 172 with respect to the fixing roller 171 is not limited to that, but for example, in an A4 vertical size configuration (specifically, about 300 mm), it is about ± 0.5 mm (inclination angle is ± 0. (About 09 degrees) can be mentioned.

At the position where the second engaging portion 112 of the operating state change region γ2b in the second cam 132 is operated, when the second cam 132 is rotated in one direction R1 in the rotation direction R, the second engaging portion 112 is swung in the swing direction. It can be moved in one direction W1 in W. As a result, the pressure roller 172 can be tilted with respect to the fixing roller 171 so that one side moves in one direction W1 in the swing direction W (higher in this example). Further, at the position where the second engaging portion 112 of the operating state change region γ2b in the second cam 132 is operated, when the second cam 132 is rotated in the other direction R2 in the rotation direction R, the second engaging portion 112 is shaken. It can be moved to the other direction W2 in the moving direction W. As a result, the pressure roller 172 can be tilted with respect to the fixing roller 171 so that one side moves in the other direction W2 in the swing direction W (lower in this example). Further, at the position where the second engaging portion 112 of the operating state change region γ2b in the second cam 132 is operated, when the second cam 132 is returned from one direction R1 or the other direction R2 in the rotation direction R, the second engaging portion The 112 can be returned from one direction W1 or the other direction W2 in the swing direction W. Thereby, the pressure roller 172 can be made parallel or substantially parallel to the fixing roller 171.

By the way, when the fixing pressure between the fixing roller 171 and the pressurizing roller 172 is equal to or higher than a predetermined pressure or larger than a predetermined pressure, the fixing belt 173 is tentatively biased to one side or the other side and is close to the fixing belt 173. When it comes into contact with a member (for example, the fixing roller 171 or the flange 174d of the heating roller 174), the fixing belt 173 is easily damaged. On the other hand, when the fixing pressure between the fixing roller 171 and the pressurizing roller 172 is smaller than the predetermined pressure or equal to or lower than the predetermined pressure, the fixing belt 173 is offset to one side or the other side, and various members close to the fixing belt 173. Even if it comes into contact with (for example, the fixing roller 171 or the flange 174d of the heating roller 174), the fixing belt 173 can be prevented from being damaged. In this respect, in the present embodiment, the pair of first cams 131, 131 attaches the pressurizing roller 172 to the fixing roller 171 at the position where the first engaging portions 111, 111 of the operating state change regions γ1b, γ1b are operated. On the other hand, when the pressure is adjusted and / or the pressure contact is released, the second cam 132 does not perform the belt offset correction operation on the second engaging portion 112.

More specifically, the pair of first cams 131, 131 uses the pair of first cams 131, 131 to connect the second cam 132 at the position where the first engaging portions 111, 111 of the operating state change regions γ1b, γ1b are operated. It is retracted from the second engaging portion 112. In this example, one of the pair of actuated members 110 and 110, the actuated member 110 (detachable member 110b in this example), has the rotation direction of the second engaging portion 112 in addition to the second engaging portion 112. Rotating shaft retracting portions 114 and 114 are provided at both ends of the R. The pair of first cams 131, 131 is a portion of the rotation shaft 120 adjacent to the second cam 132 and the second cam 132 at the position where the first engaging portions 111, 111 of the operating state change regions γ1b, γ1b are operated. At least the portion of the rotating shaft 120 (both in this example) is retracted to the rotating shaft retracting portions 114 and 114. In this example, the rotating shaft retracting portions 114 and 114 are configured to make the pressure roller 172 parallel or substantially parallel to the fixing roller 171. Specifically, the rotary shaft retracting portions 114 and 114 are insertion portions through which the rotary shaft 120 is reciprocally movable in the rotation direction V at a position where the pressure roller 172 is parallel to or substantially parallel to the fixing roller 171. It is said that. The rotating shaft retracting portions 114 and 114 are operated so that the rotating shaft 120 reciprocates in the rotational direction V at the position where the first engaging portions 111 and 111 of the operating state change region γ1b of the first cam 131 are operated. It is provided on the member 110 (in this example, the detachable member 110b). The size between the rotating shaft retracting portions 114 and 114 is slightly larger than the diameter of the rotating shaft 120 (a size that allows the rotating shaft 120 to be smoothly inserted). As a result, when the operating state of the first engaging portion 111 is changed at the position where the first engaging portions 111, 111 of the operating state changing region γ1b of the first cam 131 are operated, the second engaging portion 112 causes the second. 2 It can be configured not to operate on the engaging portion 112, and the rotating shaft 120 is inserted through the rotating shaft retracting portions 114 and 114 to make the pressure roller 172 parallel or substantially parallel to the fixing roller 171. Can be.

In this way, when the operating state of the first engaging portion 111 is changed at the position where the first engaging portions 111, 111 of the operating state changing region γ1b of the first cam 131 are operated (specifically, the pressure roller Even if it is configured so that the second engaging portion 112 does not operate on the second engaging portion 112 (specifically, the belt offset correction operation) when the pressure is adjusted to the fixing roller 171 of 172). When the fixing pressure between the fixing roller 171 and the pressurizing roller 172 is smaller than the predetermined pressure or equal to or lower than the predetermined pressure, the fixing belt 173 is offset and is close to the fixing belt 173 (for example, the fixing roller 171 or heating). Even if the roller 174 comes into contact with the flange 174d), the fixing belt 173 can be prevented from being damaged. Further, when the operating state of the first engaging portion 111 is changed at the position where the first engaging portions 111, 111 of the operating state changing region γ1b of the first cam 131 are operated (specifically, the pressure roller 172 The pressurizing roller 172 can be parallel to or substantially parallel to the fixing roller 171 (when the pressure is adjusted to the fixing roller 171), thereby minimizing the deviation of the fixing belt 173. be able to. Further, in this example, the second cam 132 located at the rotating shaft retracting portions 114 and 114 is guided to the abutting portions 112a and 112a between the rotating shaft retracting portions 114 and 114 and the contact portions 112a and 112a. Guide portions 115 and 115 are provided. To be described in detail, the guide portions 115, 115 are formed so that the size between the guide portions 115, 115 facing each other gradually decreases from the rotating shaft retracting portions 114, 114 to the contact portions 112a, 112a.

(Drive transmission mechanism)
In the present embodiment, the fixing device 17 serves as a drive transmission mechanism 180 that acts as a drive transmission means that transmits a rotational driving force to the rotary shaft 120, and as a drive means that rotationally drives the rotary shaft 120 via the drive transmission mechanism 180. It further includes a working drive unit 190. The drive transmission mechanism 180 is configured to transmit a rotational driving force from the driving unit 190 in the first rotational direction A1 and a rotational driving force in the second rotational direction A2 to the rotary shaft 120.

More specifically, the drive transmission mechanism 180 is a gear train including a plurality of gears. Specifically, the drive transmission mechanism 180 has a first gear 181 connected to the rotation shaft 191 of the drive unit 190, a second gear 182 connected to the rotation shaft 120, and a rotation driving force from the first gear 181. Is provided with a relay gear group 180a for transmitting the above to the second gear 182. The relay gear group 180a includes a plurality of (three in this example) coupling gears in which gears having different outer diameters (number of teeth) are coaxially coupled [in this example, the first coupling gear 183, the second coupling gear 184, and the first coupling gear. It is provided with a 3-coupling gear 185]. In the first coupling gear 183, the large diameter gear meshes with the first gear 181 while the small diameter gear meshes with the large diameter gear of the second coupling gear 184. In the second coupling gear 184, the large diameter gear meshes with the small diameter gear of the first coupling gear 183, while the small diameter gear meshes with the large diameter gear of the third coupling gear 185. In the third coupling gear 185, the large diameter gear meshes with the small diameter gear of the second coupling gear 184, while the small diameter gear meshes with the second gear 182. In the first coupling gear 183, the second coupling gear 184, and the third coupling gear 185, the respective rotation shafts 183a, 184a, and 185a are rotatable with respect to the image forming apparatus main body 210 (specifically, a main body frame (not shown)). It is fixed and supported.

(Control unit)
As shown in FIG. 17, the image forming apparatus 200 further includes a control unit 220 that controls the entire image forming apparatus 200. The control unit 220 may be provided in the fixing device 17 or the belt deviation correction device 300. The control unit 220 is a storage unit 222 including a processing unit 221 composed of a microcomputer such as a CPU (Central Processing Unit), a non-volatile memory such as a ROM (Read Only Memory), and a volatile memory such as a RAM (Random Access Memory). And have. The control unit 220 controls the operation of various components by loading the control program stored in the ROM of the storage unit 222 in advance into the RAM of the storage unit 222 and executing the processing unit 221. ..

-Roller pressure welding detection-
A detected portion 182a is provided on a part of the peripheral portion of the second gear 182 (see FIG. 4). The detected unit 182a is detected by the rotation position detection unit 186 that detects the rotation position of the rotation shaft 120. In this example, the detected portion 182a is a protruding portion protruding outward in the width direction X. In this example, the rotation position detecting unit 186 includes a movable unit 186a that is turned on when pressed by an external force, while is turned off when not pressed by an external force. The rotation position detection unit 186 is a sensor that turns on when the movable portion 186a is pressed by the detected portion 182a, and turns off when the pressing of the movable portion 186a by the detected portion 182a is released. The rotation position detection unit 186 is electrically connected to the input system of the control unit 220. As a result, the control unit 220 can detect (recognize) the home position (origin position) of the rotation shaft 120 by receiving an on signal from the rotation position detection unit 186 when the movable unit 186a is pressed by the detected unit 182a. can. The drive unit 190 (stepping motor in this example) is fixed to and provided on the image forming apparatus main body 210 (specifically, a main body frame (not shown) so that the rotation shaft 191 faces the rotation axis β3 direction. The drive unit 190 is electrically connected to the output system of the control unit 220.

-Roller pressure welding operation-
The control unit 220 outputs an operation signal (specifically, a pulse signal) indicating the rotation position (rotation angle) of the rotation shaft 120 with reference to the home position (origin position) of the rotation shaft 120 obtained by the rotation position detection unit 186. It is output to the drive unit 190 to control the start and stop of rotation of the pair of first cams 131, 131. As a result, the control unit 220 presses and pressurizes the pressurizing roller 172 against the fixing roller 171 by rotating the pair of first cams 131 and 131 by the drive unit 190 via the drive transmission mechanism 180 and the rotating shaft 120. Adjustment and pressure welding release can be performed.

-Belt offset detection-
On the outside of one side (front side in this example) of the fixing belt 173 in the width direction X, a single base point detecting unit 187 for detecting a predetermined base point in the width direction X orthogonal to the circumferential direction E of the fixing belt 173 is provided. It is provided. In this example, the base point detection unit 187 includes a transmissive photo sensor 187a and a movable unit 187b (specifically, an actuator) (see FIG. 8). The transmissive photosensor 187a has a light emitting unit 187a1 that emits light and a light receiving unit 187a2 that receives light from the light emitting unit 187a1. The movable portion 187b is rotatably supported by the rotating shaft 187c in the rotational direction Q around the axis of the rotating shaft 187c between the light transmitting position and the light blocking position with respect to the transmissive photo sensor 187a. The movable portion 187b has a main body portion 187b1 rotatably provided on the rotating shaft 187c, a detected portion 187b2 provided on the main body portion 187b1, and a detected portion 187b2 on the main body portion 187b1 at different angles in the circumferential direction. It has a contact portion 187b3 provided. The main body portion 187b1 is a cylindrical member, and movement in the axial direction is restricted by a pair of regulating members 187c1 and 187c1 provided on the rotating shaft 187c. The detected unit 187b2 rotates in one direction Q1 or the other direction Q2 in the rotation direction Q to block light from the light emitting unit 187a1 to the light receiving unit 187a2 in the transmissive photosensor 187a in the rotation direction Q. , A translucent position for transmitting light from the light emitting unit 187a1 to the light receiving unit 187a2 is taken. The contact portion 187b3 abuts on one end (front side in this example) of the fixing belt 173 in the width direction X. The movable portion 187b is urged by the urging member 187d (specifically, a winding spring) in the direction in which the abutting portion 187b3 abuts on the fixing belt 173 (one direction Q1 in this example).

The base point detection unit 187 (specifically, the transmissive photosensor 187a) is electrically connected to the input system of the control unit 220. As a result, the control unit 220 receives an off signal or an on signal from the base point detection unit 187 to the light receiving unit 187a2 at the light-shielding position or the light-transmitting position of the detected unit 187b2, so that the one-sided end portion of the fixing belt 173 ( The presence or absence of (an example of a base point) can be detected (recognized).

-Belt offset correction-
In the present embodiment, the control unit 220 corrects the deviation of the fixing belt 173, and when the base point detection unit 187 detects the base point, the control unit 220 does not detect that the base point in the width direction X moves away from the base point detection unit 187. The fixing belt 173 is moved to the side ST2. On the other hand, when the base point detection unit 187 does not detect the base point, the control unit 220 moves the fixing belt 173 to the detection side ST1 where the base point in the width direction X approaches the base point detection unit 187.

FIG. 18 is a flowchart showing an example of belt deviation correction control by the control unit 220. In the belt offset correction control shown in FIG. 18, the control unit 220 first determines whether or not the base point detection unit 187 has detected the base point (S1). Next, when the base point detection unit 187 detects the base point (S1: Yes), the control unit 220 moves the fixing belt 173 to the non-detection side ST2 (S2). In this example, the second cam 132 is rotated in one direction R1 in the rotation direction R at the position where the first engaging portions 111 and 111 of the operating state maintaining regions γ1a and γ1a in the pair of first cams 131 and 131 are operated. The second engaging portion 112 is moved in one direction W1 in the swing direction W, and the pressure roller 172 is moved in one direction W1 in the swing direction W with respect to the fixing roller 171 on one side (front side). Tilt to (higher in this example).

On the other hand, when the base point detection unit 187 does not detect the base point (S1: No), the control unit 220 moves the fixing belt 173 to the detection side ST1 (S3). In this example, the second cam 132 is rotated in the other direction R2 in the rotation direction R at the position where the first engaging portions 111 and 111 of the operating state maintaining regions γ1a and γ1a in the pair of first cams 131 and 131 are operated. The second engaging portion 112 is moved in the other direction W2 in the swing direction W, and one side (front side) of the pressurizing roller 172 with respect to the fixing roller 171 is moved in the other direction W2 in the swing direction W. Tilt to (lower in this example).

In this way, the control unit 220 can correct the deviation of the fixing belt 173 by detecting the base point on the fixing belt 173 by the single base point detecting unit 187.

Then, the control unit 220 determines whether or not there is an instruction to end the process (S4), and if there is no instruction to end the process (S4: No), the process proceeds to step S1 and the processes of S1 to S4 are repeated. On the other hand, when there is an instruction to end the process (S4: Yes), the process ends.

According to the present embodiment, since a single base point detection unit 187 is used as the detection unit for detecting the position of the fixing belt 173 in the width direction X, the configuration can be simplified and the cost can be kept low. be able to. Further, since the base point detection unit 187 detects a predetermined base point in the width direction X of the fixing belt 173, the base point detection unit 187 is a general-purpose and inexpensive one (for example, a photo sensor including a light emitting unit and a light receiving unit). Can be used. Moreover, when the base point detection unit 187 detects the base point, the fixing belt 173 is moved to the non-detection side ST2, while when the base point detection unit 187 does not detect the base point, the fixing belt 173 is moved to the detection side ST1. Therefore, the control configuration for belt deviation correction can be simplified.

In this example, the base point detection unit 187 is a transmissive photosensor including a light emitting unit 187a1 and a light receiving unit 187a2. The base point detection unit 187 uses the end of one side (front side in this example) of the fixing belt 173 in the width direction X as the base point and the end of one side (front side in this example) of the fixing belt 173 in the width direction X. Detect. Therefore, the detection side ST1 is one side in the width direction X (front side in this example), and the non-detection side ST2 is the other side in the width direction X (back side in this example). By doing so, the base point on the fixing belt 173 can be easily detected by the base point detection unit 187.

The base point is the end of the fixing belt 173 on the other side (back side in this example) in the width direction X, and the base point detecting unit 187 is on the other side (back side in this example) of the fixing belt 173 in the width direction X. The end may be detected. In this case, the detection side ST1 is the other side in the width direction X (the back side in this example), and the non-detection side ST2 is the one side in the width direction X (the front side in this example). Further, the base point detection unit 187 is a reflective photosensor provided with a light emitting unit 187a1 and a light receiving unit 187a2, and a predetermined width (for example, in the tilting direction of the pressurizing roller 172) is formed between both ends of the fixing belt 173 in the width direction X. A detected region having a width equal to or greater than the moving distance of the fixing belt 173 required for switching (for example, a detected region having a reflectance equal to or higher than a predetermined threshold for the light reflectance of the fixing belt 173) is covered over the entire circumferential direction. The base point detection unit 187 may detect the detected area on the fixing belt 173 with the detected area as the base point. In this case, the detection side ST1 is one side in the width direction X (front side in this example), the non-detection side ST2 is the other side in the width direction X (back side in this example), and / or the detection side ST1 Can be the other side in the width direction X (the back side in this example), and the non-detection side ST2 can be the one side in the width direction X (the front side in this example).

Here, when the base point detection unit 187 detects the end portion of the fixing belt 173 in the width direction X as the base point, the non-detection side ST2 for moving the fixing belt 173 is on the center side of the fixing belt 173 in the width direction X. be. Further, when the base point detection unit 187 detects the detected area provided between both ends of the fixing belt 173 as the base point, the non-detection side ST2 for moving the fixing belt 173 is in the width direction X of the fixing belt 173. It is on the end side of either one. In any case, the detection side ST1 that moves the fixing belt 173 when the base point detection unit 187 does not detect the base point is on the opposite side to the non-detection side ST2. When the base point detection unit 187 detects the detected area, the control unit 220 sets the fixing belt 173 on one side in the width direction X (in this example, the front side) when the detected area is not detected at the initial stage. ) And the other side (in this example, the back side) for a predetermined initial movement time, and after the base point detection unit 187 detects the detected area, the belt deviation correction can be started. If the base point detection unit 187 does not detect the detected area even after the initial movement time has elapsed, the control unit 220 can gradually increase the initial movement time.

In the present embodiment, the operating mechanism 100 swings the correction roller (pressurizing roller 172 in this example) for moving the fixing belt 173 in the width direction X so as to be tiltable with respect to the circumferential axis of the fixing belt 173. It is configured.

FIG. 19 is a graph for explaining the inconvenience when correcting the deviation of the fixing belt 173. FIG. 19A shows a state in which the inclination range of the pressure roller 172 by the operating mechanism 100 is balanced in the width direction X, and FIG. 19B shows the inclination of the pressure roller 172 by the operating mechanism 100. A state in which the range is shifted to the detection side ST1 is shown, and FIG. 19C shows a state in which the inclination range of the pressure roller 172 by the operating mechanism 100 is shifted to the non-detection side ST2. In FIG. 19, the horizontal axis represents the elapsed time, the vertical axis represents the moving distance of the base point on the fixing belt 173, and the origin on the vertical axis represents the time when the base point detection unit 187 detects the base point. Further, the range below the horizontal axis represents the range of the detection side ST1, and the range above the horizontal axis represents the range of the non-detection side ST2.

In the present embodiment, the control unit 220 swings the pressure roller 172 at a predetermined swing speed (constant or substantially constant swing speed) so that the pressure roller 172 can be tilted with respect to the circumferential axis of the fixing belt 173 by the operating mechanism 100. By moving the fixing belt 173, the fixing belt 173 is moved in the width direction X. Then, in correcting the deviation of the fixing belt 173, when the base point detecting unit 187 detects the base point, the belt is moved to the non-detection side ST2, but in the fixing belt 173, the base point detecting unit 187 detects the base point. The pressure roller 172 moves from the detection time point D1 to the detection side ST1 by the time required for switching the tilting direction of the pressure roller 172. Similarly, when the base point detection unit 187 does not detect the base point, the fixing belt 173 is moved to the detection side ST1, but the fixing belt 173 pressurizes from the non-detection time point D2 where the base point detection unit 187 does not detect the base point. The roller 172 moves to the non-detection side ST2 by the time required for switching the tilting direction.

By the way, when the actuating mechanism 100 swings the pressurizing roller 172 at a predetermined swing speed so as to be tiltable with respect to the circumferential axis of the fixing belt 173, the actuating mechanism corrects the deviation of the pressurizing roller 172. When the tilt range (tilt angle range) of the pressurizing roller 172 by 100 is balanced in the width direction X [see FIG. 19 (a)], the detection time T1 (for example, 10 seconds) from the detection time D1 to the non-detection time D2. Degree) and the non-detection time T2 (for example, about 10 seconds) from the non-detection time point D2 to the detection time point D1 are equal or substantially equal. On the other hand, the inclination range of the pressure roller 172 by the operating mechanism 100 shifts to the detection side ST1 due to the variation of the parts of various members (in this example, the pressure roller 172 is low on the detection side ST1 and the non-detection side ST2. [See FIG. 19 (b)], the detection time T1 becomes larger than the non-detection time T2. Further, when the tilt range of the pressure roller 172 by the operating mechanism 100 is shifted to the non-detection side ST2 (in this example, the pressure roller 172 is tilted so as to be high on the detection side ST1 and low on the non-detection side ST2). [See FIG. 19 (c)], the non-detection time T2 becomes larger than the detection time T1. Then, the belt deviation correction by the control unit 220 cannot be smoothly performed. Therefore, it is desired that the inclination range of the pressure roller 172 is balanced in the width direction X and the belt deviation correction by the control unit 220 is smoothly performed.

In this regard, in the present embodiment, the control unit 220 measures the detection time T1 and the non-detection time T2, and operates the operation mechanism so that the time difference between the detection time T1 and the non-detection time T2 falls within a predetermined time range. The tilt range of the pressurizing roller 172 by 100 is shifted. By doing so, the detection time T1 and the non-detection time T2 can be made equal or substantially equal. Therefore, the inclination range of the pressure roller 172 can be balanced in the width direction X, and the belt deviation correction by the control unit 220 can be smoothly performed.

FIG. 20 is an explanatory diagram for explaining the inclination range shift mechanism 310. FIG. 20A is a schematic perspective view of the locking portion 110g viewed from diagonally above on the back side, and FIG. 20B is a schematic perspective view of the locking portion 110g viewed from diagonally above on the front side. 20 (c) is a schematic rear view showing an opening 110h in the detachable member 110b of the actuated member 110, and FIG. 20 (d) relates to the opening 110h in the detachable member 110b of the actuated member 110. It is the schematic rear view which shows the state which the stop part 110g was inserted. In FIGS. 20 (c) and 20 (d), the index ID "F" shifts the inclination range of the pressure roller 172 to the detection side ST1 (in this example, the pressure roller 172 is lower on the detection side ST1). It also means a direction in which the pressure roller 172 is tilted so as to be higher on the non-detection side ST2. Further, the index ID "R" shifts the inclination range of the pressurizing roller 172 to the non-detection side ST2 (in this example, the pressurizing roller 172 is pressurized so as to be high on the detection side ST1 and low on the non-detection side ST2). It means the direction in which the roller 172 is tilted).

The belt deviation correction device 300 includes an inclination range shift mechanism 310 (in this example, a locking portion 110g and an opening 110h) for shifting the inclination range of the pressure roller 172. The belt deviation correction device 300 adjusts the shift amount of the tilt range of the pressure roller 172 by shifting the tilt range of the pressure roller 172 with the tilt range shift mechanism 310.

By doing so, the inclination range of the pressure roller 172 can be easily shifted manually or automatically by the inclination range shift mechanism 310. For example, as in the present embodiment, a worker such as a serviceman can manually rotate the locking portion 110g using a jig such as a Phillips screwdriver. A tilt range shift drive unit (not shown) for driving the tilt range shift mechanism 310 is provided, and the control unit 220 keeps the time difference between the detection time T1 and the non-detection time T2 within a predetermined time range. The tilt range of the pressurizing roller 172 may be shifted by the tilt range shift drive unit.

In this example, the locking portion 110g is adjusted with a columnar shaft portion 311 and a columnar adjusting cam 312 which is connected to one end of the shaft portion 311 and has a diameter larger than the diameter of the shaft portion 311. It is composed of a columnar tip portion 313 which is connected to the use cam 312 and has a diameter larger than the diameter of the adjustment cam 312. The adjusting cam 312 is eccentric with respect to the shaft portion 311 and the center δ2 is deviated from the rotation axis δ1 of the shaft portion 311. Further, the tip portion 313 is located coaxially with the rotation axis δ1 of the shaft portion 311. On the other hand, the upper end of the detachable member 110b in the actuated member 110 has a long shape (in this example, a bale shape) along the swing direction W or the swing direction W side direction (in this example, the swing direction W side direction). ) Is provided with an opening 110h. The diameter φ of the adjusting cam 312 is smaller than the distance e in the lateral direction of the opening 110h by a predetermined distance. Then, the shaft portion 311 and the adjusting cam 312 in the locking portion 110g are inserted through the opening 110h in the detachable member 110b, and the adjusting cam 312 faces the opening 110h. By doing so, the locking portion 110g is rotated in one direction R1 (F side of the index ID) in the rotation direction R, so that the detachable member 110b becomes one direction W1 in the swing direction W with respect to the main body member 110a. It can be moved relatively. Then, the main body member 110a moves relative to the detachable member 110b in the other direction W2, whereby the inclination range of the pressure roller 172 is shifted to the detection side ST1 (in this example, the pressure roller 172 moves. The pressure roller 172 can be tilted so as to be low on the detection side ST1 and high on the non-detection side ST2). Further, by rotating the locking portion 110g in the other direction R2 (R side of the index ID) in the rotation direction R, the detachable member 110b is relatively relative to the other direction W2 in the swing direction W with respect to the main body member 110a. Can be moved. Then, the main body member 110a moves relative to W1 with respect to the detachable member 110b, whereby the inclination range of the pressure roller 172 is shifted to the non-detection side ST2 (in this example, the pressure roller 172 moves. The pressure roller 172 can be tilted so as to be high on the detection side ST1 and low on the non-detection side ST2). In this example, when rotating the locking portion 110g, the fixing member SC of the detachable member 110b is loosened, the inclination range of the pressure roller 172 is shifted, and then the fixing member SC is loosened to loosen the detachable member 110b. It is fixed to the main body member 110a. Thereby, the inclination range of the pressure roller 172 can be shifted, and therefore the shift amount of the inclination range of the pressure roller 172 can be adjusted.

Further, an index ID (specifically, a scale) that serves as a guide for the shift amount in the inclination range of the pressure roller 172 is provided on the peripheral edge of the opening 110h of the operated member 110. The tip portion 313 of the locking portion 110g is provided with a locking groove 313a for locking a jig such as a Phillips screwdriver and an indicating portion 313b for pointing to an index ID.

FIG. 21 is a chart showing the formulas (1) and (2) of the calculation formula used when adjusting the shift amount in the inclination range of the pressure roller 172, and the adjustment tables TB1 and TB2. FIG. 21 (a) shows a case where the molecule of the calculation formula (1) is set to the detection time T1, and FIG. 21 (b) shows the case where the molecule of the calculation formula (2) is the non-detection time T2. The case is shown. Here, the equation (1) expresses the ratio of the detection time T1 to the total of the detection time T1 and the non-detection time T2, and the equation (2) is the non-existence of the total of the detection time T1 and the non-detection time T2. It represents the ratio of the detection time T2. When the tilt range shift mechanism 310 manually shifts the tilt range of the pressurizing roller 172, the operator sets the value calculated by the control unit 220 in the equation (1) or the equation (2) in the adjustment table TB1 of FIG. , The inclination range of the pressure roller 172 is shifted with reference to TB2. Further, when the tilt range shift mechanism 310 automatically shifts the tilt range of the pressurizing roller 172, the adjustment tables TB1 and TB2 of FIG. 21 are stored in advance in the storage unit 222, and the control unit 220 expresses the formula (1). ) Or the value obtained by calculating the equation (2) is used to shift the tilt range of the pressurizing roller 172 by controlling the operation of the tilt range shift drive unit based on the adjustment tables TB1 and TB2 in the storage unit 222. ..

For example, when the detection time T1 is 15 seconds and the non-detection time T2 is 5 seconds, the movement time to the R side is longer than the movement time to the F side. From this, the value of the formula (1) is 0.75, and the value of the formula (2) is 0.25. With reference to the adjustment tables TB1 and TB2, the instruction of the tip portion 313 in the locking portion 110g is indicated. The portion 313b is shifted by 2 scales from the current position in the R side direction. Further, when the detection time T1 is 5 seconds and the non-detection time T2 is 15 seconds, the movement time to the F side is longer than the movement time to the R side. From this, the value of the formula (1) is 0.25, and the value of the formula (2) is 0.75. With reference to the adjustment tables TB1 and TB2, the instruction of the tip portion 313 in the locking portion 110g is indicated. The portion 313b is shifted by 2 scales from the current position toward the F side.

In the present embodiment, the correction roller is an opposed roller that sandwiches the belt together with any one of a plurality of belt rollers (heating roller 174 and fixing roller 171 in this example) (fixing roller 171 in this example). (Pressurized roller 172 in this example). The pressure roller 172 is capable of swinging around the swing axis β5 which is orthogonal to or substantially orthogonal to the roller axis of the pressure roller 172. By doing so, the fixing belt 173 can be easily moved in the width direction X.

In the present embodiment, the control unit 220 swings the pressure roller 172 within a predetermined swing speed range, and when shifting the inclination range of the pressure roller 172, the control unit 220 causes the pressure roller 172 to fall within the swing speed range. Swing at the maximum speed of. By doing so, the detection time T1 and the non-detection time T2 can be quickly measured.

In the present embodiment, the control unit 220 swings the pressure roller 172 at a plurality of swing speeds to correct the deviation of the fixing belt 173, and detects the base point even if the predetermined reference elapsed time is exceeded. If there is no change in the detection of the base point by the base point detection unit 187, the step of the swing speed of the pressurizing roller 172 is increased (for example, one step or a plurality of steps), and if there is a change in the detection of the base point by the base point detection section 187, the step is added. The step of the rocking speed of the compression roller 172 is lowered (to the slowest step in this example). By doing so, the belt deviation correction can be performed quickly.

FIG. 22 is a flowchart showing another example of belt deviation correction control by the control unit 220. In this example, the fixing belt 173 is oscillated at a plurality of oscillating speeds. That is, in the belt deviation correction control shown in FIG. 18, prior to the belt deviation correction, the stage of the swing speed of the pressurizing roller 172 to the detection side ST1 and the stage of the swing speed of the pressure roller 172 to the non-detection side ST2. Is set to the latest stage, and the first reference elapsed time and the second reference elapsed time are set as initial values. Then, the control unit 220 first determines whether or not the base point detection unit 187 has detected the base point (S11). Next, when the base point detection unit 187 detects the base point (S11: Yes), the control unit 220 moves the fixing belt 173 to the non-detection side ST2 (S12). Next, the control unit 220 determines whether or not the base point is detected even if the detection elapsed time from the time when the base point detection unit 187 detects the base point exceeds the first reference elapsed time (S13). When the base point detection unit 187 detects the base point even after the first reference elapsed time has been exceeded (S13: Yes), the control unit 220 steps at the swing speed of the pressurizing roller 172 to the non-detection side ST2. Is increased by one step (S14), the first reference elapsed time is increased (S15), and the process shifts to S24. Further, when the base point detection unit 187 does not detect the base point within the first reference elapsed time (S13: No), the control unit 220 steps the rocking speed of the pressurizing roller 172 to the non-detection side ST2. Is set to the latest stage (S16), the first reference elapsed time is set to the initial value (S17), and the process proceeds to S24.

On the other hand, when the base point detection unit 187 does not detect the base point (S11: No), the control unit 220 moves the fixing belt 173 to the detection side ST1 (S18). Next, the control unit 220 determines whether or not the base point is not detected even if the non-detection elapsed time from the time when the base point detection unit 187 does not detect the base point exceeds the second reference elapsed time (S19). ). When the base point detection unit 187 does not detect the base point even after the second reference elapsed time has passed (S19: Yes), the control unit 220 determines the stage of the swing speed of the pressurizing roller 172 to the detection side ST1. One step up (S20), the second reference elapsed time is increased (S21), and the process shifts to S24. Further, when the base point detection unit 187 detects the base point within the second reference elapsed time (S19: No), the control unit 220 has the slowest step of the swing speed of the pressurizing roller 172 to the detection side ST1. The stage is set (S22), the second reference elapsed time is set to the initial value (S23), and the process proceeds to S24.

Then, the control unit 220 determines whether or not there is an instruction to end the process (S24), and if there is no instruction to end the process (S24: No), the process proceeds to step S11 and the processes of S11 to S24 are repeated. On the other hand, when there is an instruction to end the process (S24: Yes), the process ends.

(Other embodiments)
In the present embodiment, the pressure roller 172 is used as the correction roller, but a heating roller 174 or a fixing roller 171 may be used. Further, although the belt offset correction device 300 is applied to the belt type fixing device 17, it may be applied to the belt type transfer device (for example, the primary transfer belt device 6 or the secondary transfer belt device 10). Further, although the endless belt is wound around two belt rollers, it may be wound around three or more belt rollers.

The present invention is not limited to the embodiments described above, and can be implemented in various other forms. Therefore, such embodiments are merely exemplary in all respects and should not be construed in a limited way. The scope of the present invention is shown by the claims and is not bound by the text of the specification. Furthermore, all modifications and modifications that fall within the equivalent scope of the claims are within the scope of the present invention.

100 Acting mechanism 110 Operated member 110h Opening 111 First engaging portion 112 Second engaging portion 113 Rotating support shaft 114 Rotating shaft retracting portion 115 Guide portion 120 Rotating shaft 131 First cam 132 Second cam 17 Fixing device 171 Fixing Roller 172 Pressurizing roller 173 Fixing belt 174 Heating roller 175 Biasing member 180 Drive transmission mechanism 187 Base point detection unit 190 Drive unit 191 Rotating shaft 200 Image forming device 220 Control unit 300 Belt offset correction device 310 Tilt range shift mechanism 311 Shaft unit 312 Adjustment cam 313 Tip D1 Detection time D2 Non-detection time E Circulation direction P Sheet ST1 Detection side ST2 Non-detection side T1 Detection time T2 Non-detection time W Swing direction X Width direction Y Left-right direction

Claims (9)

A belt Katayose correction method for correcting a plurality of offset of wound around belts to the belt roller,
A single base point detection unit that detects a predetermined base point in the width direction of the belt is used as a detection unit that detects a position in the width direction orthogonal to the circumferential direction of the belt, and in correcting the deviation of the belt. , if the previous SL base detection unit does not detect the base, while the base point in the width direction before moving the belt on the detection side closer to the base point detecting unit, the base point detecting unit said base point when detecting moves the belt to the non-detection side moving away from the base point detecting unit opposite to the base point the detection side,
By swinging the correction roller for moving the belt in the width direction at a predetermined swing speed so as to be tiltable with respect to the circumferential axis of the belt, the belt is moved in the width direction and the base point is detected. The detection time from the detection time when the unit detects the base point to the non-detection time when it is not detected and the non-detection time from the non-detection time to the detection time are measured, and the time difference between the detection time and the non-detection time. Shifts the tilt range of the correction roller so that
The correction roller is oscillated within a predetermined oscillating speed range.
The correction when shifting the tilt range of the rollers, the belt Katayose correction method is rocked at the maximum speed, characterized in Rukoto of the correction roller the swing speed range. The belt offset correction method according to claim 1.
The correction roller is oscillated at a plurality of oscillating speeds.
When correcting the deviation of the belt, if there is no change in the detection of the base point by the base point detection unit even if the predetermined reference elapsed time is exceeded, the step of the swing speed of the correction roller is increased to raise the base point. A belt deviation correction method, characterized in that the step of the swing speed of the correction roller is lowered when there is a change in the detection of the base point by the detection unit. This is a belt deviation correction method that corrects the deviation of the belt wound around multiple belt rollers.
A single base point detection unit that detects a predetermined base point in the width direction of the belt is used as a detection unit that detects a position in the width direction orthogonal to the circumferential direction of the belt, and in correcting the deviation of the belt. When the base point detection unit does not detect the base point, the belt is moved to the detection side where the base point approaches the base point detection unit in the width direction, while the base point detection unit detects the base point. In the case, the belt is moved to the non-detection side where the base point is away from the base point detection unit on the side opposite to the detection side.
By swinging the correction roller for moving the belt in the width direction at a predetermined swing speed so as to be tiltable with respect to the circumferential axis of the belt, the belt is moved in the width direction and the base point is detected. The detection time from the detection time when the unit detects the base point to the non-detection time when it is not detected and the non-detection time from the non-detection time to the detection time are measured, and the time difference between the detection time and the non-detection time. Shifts the tilt range of the correction roller so that
The correction roller is oscillated at a plurality of oscillating speeds.
When correcting the deviation of the belt, if there is no change in the detection of the base point by the base point detection unit even if the predetermined reference elapsed time is exceeded, the step of the swing speed of the correction roller is increased to raise the base point. A belt deviation correction method, characterized in that the step of the swing speed of the correction roller is lowered when there is a change in the detection of the base point by the detection unit. The belt offset correction method according to any one of claims 1 to 3.
A belt deviation correction method, characterized in that one end of the belt in the width direction is used as the base point. The belt offset correction method according to any one of claims 1 to 4.
A belt offset correction method characterized in that the shift amount of the tilt range of the correction roller is adjusted by shifting the tilt range of the correction roller with the tilt range shift mechanism for shifting the tilt range of the correction roller. .. The belt offset correction method according to any one of claims 1 to 5.
The correction roller is an opposing roller that sandwiches the belt together with any one of the plurality of belt rollers, and swings around a swing axis orthogonal to or substantially orthogonal to the roller axis of the correction roller. A belt offset correction method characterized by being possible. A belt Katayose correcting device for correcting a plurality of offset of wound around belts to the belt roller,
A single base point detecting unit for detecting a predetermined base point in the width direction orthogonal to the circumferential direction of the belt is provided.
Upon correcting the offset of the belt, if the previous SL base detection unit does not detect the base, while the base point in the width direction Before moving the belt on the detection side closer to the base point detecting unit , when said base detecting unit detects the base moves the belt to the non-detection side moving away from the base point detecting unit opposite to the base point the detection side,
By swinging the correction roller for moving the belt in the width direction at a predetermined swing speed so as to be tiltable with respect to the circumferential axis of the belt, the belt is moved in the width direction and the base point is detected. The detection time from the detection time when the unit detects the base point to the non-detection time when it is not detected and the non-detection time from the non-detection time to the detection time are measured, and the time difference between the detection time and the non-detection time. Shifts the tilt range of the correction roller so that
The correction roller is oscillated within a predetermined oscillating speed range.
The correction when shifting the tilt range of the rollers, the belt Katayose correcting device according to claim Rukoto rocked at the maximum speed of the swing speed range the correction roller. It is a belt deviation correction device that corrects the deviation of the belt wound around multiple belt rollers.
A single base point detecting unit for detecting a predetermined base point in the width direction orthogonal to the circumferential direction of the belt is provided.
When the base point detection unit does not detect the base point in correcting the deviation of the belt, the belt is moved to the detection side where the base point approaches the base point detection unit in the width direction, while the belt is moved. When the base point detection unit detects the base point, the belt is moved to a non-detection side where the base point is away from the base point detection unit on the side opposite to the detection side.
By swinging the correction roller for moving the belt in the width direction at a predetermined swing speed so as to be tiltable with respect to the circumferential axis of the belt, the belt is moved in the width direction and the base point is detected. The detection time from the detection time when the unit detects the base point to the non-detection time when it is not detected and the non-detection time from the non-detection time to the detection time are measured, and the time difference between the detection time and the non-detection time. Shifts the tilt range of the correction roller so that
The correction roller is oscillated at a plurality of oscillating speeds.
When correcting the deviation of the belt, if there is no change in the detection of the base point by the base point detection unit even if the predetermined reference elapsed time is exceeded, the step of the swing speed of the correction roller is increased to raise the base point. A belt offset correction device characterized in that the step of the swing speed of the correction roller is lowered when there is a change in the detection of the base point by the detection unit. An image forming apparatus comprising the belt offset correction device according to claim 7 or 8.

Images