JP6965131B2 - Image forming device - Google Patents

Description

The present invention relates to an electrophotographic copying machine, a printer, a facsimile, and an image forming apparatus such as a multifunction device having a plurality of these functions, which forms an image on a sheet-shaped recording material.

In the image forming apparatus as described above, the toner image of the sheet-shaped recording material (hereinafter referred to as paper or paper) fed from the feeding unit is transferred by the transfer device, and then transferred to the fixing device to be conveyed to the fixing device. The toner image is fixed on the paper. A plurality of transfer guide members that form a transfer path for the paper so as to guide the paper that has passed through the transfer position to the fixing nip are installed between the transfer portion and the fixing portion.

When a paper jam (hereinafter referred to as jam) occurs in the transfer path between the transfer portion and the fixing portion, a part of the plurality of transfer guide members is moved from the transfer path, and the transfer path formed by the part thereof. To open. It is known that the jammed paper is taken out from the transport path by this (Patent Document 1).

Further, in the configuration in which the transport path is formed by a plurality of movable transport members as described above, by providing a region in which a part of the plurality of transport members is meshed in a comb shape and overlapped with each other, the transport members are provided with each other. Also, good transportability is realized.

Japanese Unexamined Patent Publication No. 2013-234011

As described above, in the configuration in which a plurality of transport members mesh in a comb-teeth shape, some of the transport members move due to the jam processing operation and while the transport path is opened, they overlap due to an erroneous operation by the user or the like. Paper may get stuck in the area to be used. In such a case, when some of the moving transport members return from the open position to the closed position again, the paper is caught in the overlapping region between the transport members, so that the comb teeth cannot be engaged. In addition, the transport member that receives the force through the paper may be deformed or damaged.

An object of the present invention has been made in view of the above circumstances, and an object of the present invention is to suppress damage to a guide due to pinching of a recording material with a simple configuration.

A typical configuration of the image forming apparatus according to the present invention for achieving the above object is
At the transfer nip, a transfer unit that transfers the toner image to the recording material, and
At the fixing nip part, a fixing part for fixing the toner image formed by the transfer part to the recording material, and a fixing part.
An opening provided in the main body of the apparatus for accommodating the transfer portion and the fixing portion,
An opening / closing member capable of having a closing position for closing the opening and an opening position for opening the opening.
A first guide member and a second guide member that form a transport surface for a recording material from the transfer nip portion to the fixing nip portion in a state where the opening / closing member is in a closed position.
The transport surface has a support surface that extends in a width direction that is orthogonal to the transport direction of the recording material and supports the first guide member over the width direction, and the support surface has the first support surface. Has a metal plate to which the guide member is fixed,
When the opening / closing member is in the open position, the first guide member is located in the apparatus main body.
The second guide member moves together with the opening / closing member in conjunction with the opening / closing operation of the opening / closing member.
In the first guide member and the second guide member, the convex portion of the second guide member becomes the first guide member as the opening / closing member moves from the open position to the closed position. By being located in the recess of, the transport surface is formed.
When the opening / closing member is in the closed position, the first guide member is located on the downstream side of the second guide member in the transport direction of the recording material.
When the transport surface is viewed when the opening / closing member is in the closed position, the recess of the first guide member is recessed toward the downstream side in the transport direction, and the convex of the second guide member. The portion protrudes toward the downstream side in the transport direction.
When viewed from the width direction, the first guide member first overlaps with the movement locus of the convex portion of the second guide member due to the closing operation of the opening / closing member among the first guide members. It has a convex curved surface shape at the position where it is
A projection surface when the movement locus of the convex portion of the second guide member and the first guide member and the metal plate at a position having the curved surface shape portion in the width direction are viewed from the width direction. In the movement locus of the convex portion of the second guide member accompanying the closing operation of the opening / closing member, a point at which the curved surface shape portion starts to overlap is set as a point Q, and the point Q is set as a virtual contact point. When the normal line to the virtual tangent line of the curved surface shape portion is set to the normal line L, the curved surface shape portion is provided so that the normal line L intersects the support surface of the metal plate. It is a feature.

According to the present invention, it is possible to suppress damage to the guide due to pinching of the recording material with a simple configuration.

Schematic diagram of the main part of the embodiment Longitudinal front schematic view of the image forming apparatus of the embodiment Enlarged schematic view of the fixing device portion of the image forming apparatus of FIG. (A) is a front schematic view of the fixing belt assembly and the pressure roller portion in the fixing device, and (b) is a vertical sectional front schematic view thereof. Block diagram of the control system of the fixing device The figure which showed the open state of the opening and closing door Another diagram showing the open door Frontal schematic view of entrance guide and post-transcriptional guide Schematic diagram for explaining the change in the relative positions of the inlet guide and the post-transcriptional guide during paper jam processing and the resulting interference of paper. Schematic diagram of the main part of Example 2

<< Example 1 >>
(1) Image Forming Unit FIG. 2 is a schematic vertical cross-sectional view showing a schematic configuration of an electrophotographic full-color printer which is an example of an image forming apparatus 30 equipped with an image heating device according to the present invention as a fixing device 20. First, the outline of the image forming unit will be described.

The printer 30 performs an image drawing operation in response to input image information from an external host device 200 communicably connected to a control circuit unit (control means: CPU) 100 to form a full-color image on a recording material and output the printer 30. can do. The external host device 200 is a computer, an image reader, or the like. The control circuit unit 100 exchanges signals with the external host device 200. It also sends and receives signals to and from various image-drawing devices, and controls image-drawing sequences.

Reference numeral 8 denotes an endless and flexible intermediate transfer belt (hereinafter abbreviated as a belt), which is stretched between the secondary transfer opposed roller 9 and the tension roller 10 to drive the roller 9. Is driven to rotate at a predetermined speed in the counterclockwise direction of the arrow. Reference numeral 11 denotes a secondary transfer roller, which is pressed against the above-mentioned secondary transfer opposed roller 9 via a belt 8. The contact portion (transfer nip portion) between the belt 8 and the secondary transfer roller 11 is the secondary transfer portion (first position) A.

1Y, 1M, 1C, and 1Bk are the first to fourth image forming portions, and are arranged in a row on the lower side of the belt 8 at predetermined intervals along the belt moving direction. Each image forming unit is a laser exposure type electrophotographic process mechanism, and each is a drum-type electrophotographic photosensitive member (hereinafter, abbreviated as drum) as an image carrier that is rotationally driven at a predetermined speed in the clockwise direction of the arrow. ) Has 2. A primary charger 3, a developing device 4, a transfer roller 5 as a transfer means, and a drum cleaner device 6 are arranged around each drum 2.

Each transfer roller 5 is arranged inside the belt 8 and is pressed against the corresponding drum 2 via the downward belt portion of the belt 8. The contact portion between each drum 2 and the belt 8 is the primary transfer portion. Reference numeral 7 denotes a laser exposure apparatus for the drum 2 of each image forming unit, which is composed of a laser emitting means, a polygon mirror, a reflection mirror, and the like that emit light corresponding to a time-series electric digital pixel signal of the given image information.

The control circuit unit 100 causes each image forming unit to perform an image forming operation based on the color-separated image signal input from the external host device 200. As a result, in the first to fourth image forming units 1Y, 1M, 1C, and 1Bk, yellow (Y), magenta (M), and cyan (C) are used at predetermined control timings with respect to the surface of the rotating drum 2. ), Black (Bk) color toner image is formed. Since the principle and process of electrophotographic image formation for forming a toner image on the drum 2 are known, the description thereof will be omitted.

The above toner images formed on the surface of the drum 2 of each image forming unit are rotationally driven by the primary transfer unit in the forward direction with the rotation direction of each drum 2 and at a speed corresponding to the rotation speed of each drum 2. It is sequentially superimposed and transferred to the outer surface of the belt 8. As a result, an unfixed full-color toner image is synthesized and formed on the surface of the belt 8 by superimposing the above four color toner images.

On the other hand, among the upper and lower multi-stage cassette feeding units 13A, 13B, and 13C in which recording materials (sheets: hereinafter referred to as paper or paper) P of various sizes of various sizes are loaded and accommodated at predetermined feeding timings. The paper feed roller 14 of the paper paper cassette of the selected stage is driven. As a result, one sheet of paper P loaded and stored in the paper feed cassette at that stage is separately fed and conveyed to the resist roller pair 16 through the vertical transfer path 15.

When manual paper feed is selected, the paper feed roller 18 is driven. As a result, one sheet of paper loaded and set on the manual feed tray (multi-purpose tray) 17 is separately fed and conveyed to the resist roller pair 16 through the vertical transfer path 15.

The resist roller pair 16 is arranged so that the tip of the paper P reaches the secondary transfer portion A at the timing when the tip of the full-color toner image on the rotating belt 8 reaches the secondary transfer portion A. Is timely transported. As a result, in the secondary transfer unit A, the full-color toner images on the belt 8 are collectively secondarily transferred to the surface of the paper P. The paper leaving the secondary transfer section A is separated from the surface of the belt 8 and introduced into the fixing device (fixing section) 20 through the vertical transfer path 19.

The fixing nip portion (second position) N of the fixing device 20 melts and mixes the toner images of the plurality of colors (Y color + M color + C color + Bk color) and fixes them on the paper surface as a fixed image. The paper leaving the fixing device 20 is sent out onto the paper ejection tray 23 by the paper ejection rollers 22 through the transport path 21 as a full-color image forming product. The surface of the belt 8 after the paper is separated by the secondary transfer unit A is cleaned by the belt cleaning device 12 after removing residual deposits such as the secondary transfer residual toner, and is repeatedly subjected to image drawing.

In the mono-black print mode, only the fourth image forming unit Bk that forms the Bk color toner image is controlled in the image drawing operation.

When the double-sided print mode is selected, the first-side printed paper is fed onto the output tray 23 by the output roller pair 22, and the rear end portion is immediately before passing through the output roller pair 22. At this point, the rotation of the paper ejection roller vs. 22 is converted to reverse. As a result, the paper is switched back and introduced into the re-conveyance path 24. Then, it is turned upside down and conveyed to the resist roller pair 16 again. After that, as in the case of printing on the first side, the image is conveyed to the secondary transfer unit A and the fixing device 20 and sent out on the output tray 23 as a double-sided print image forming product.

As described above, the printer 30 of this example is formed by forming an image forming portion for forming a toner image on the paper P at the first position (secondary transfer portion) A and forming the toner image on the paper P by the image forming portion. It has a fixing portion (fixing device) for fixing the toner image at a second position (fixing nip portion) N.

Further, in the printer 30 of this example, the paper P is transported by the vertical transport path 19. In the printer 30 of this example, the paper P is conveyed upward in the direction of gravity in the transfer path from the transfer nip portion A to the fixing nip portion N. That is, the fixing nip portion N is located above the transfer nip portion A in the direction of gravity.

(2) Fixing device 20
In the following description, the longitudinal direction (width direction) of the fixing device 20 or the members constituting the fixing device 20 is a direction parallel to the direction orthogonal to the paper transport direction (recording material transport direction) in the paper transport path surface. With respect to the fixing device 20, the front is the surface on the paper introduction side, and the left and right are left or right when the device is viewed from the front. The width of the paper is the size of the paper in the direction orthogonal to the paper transport direction on the paper surface.

FIG. 3 is an enlarged vertical cross-sectional schematic view of the portion of the fixing device 20 in FIG. FIG. 4A is a schematic front view of the fixing belt assembly of the fixing device 20 and the portion of the pressurizing roller (fixing mechanism portion 20A), FIG. 4B is a schematic front view of the vertical section thereof, and FIG. 5 is a control system of the fixing device 20. It is a block diagram of.

This fixing device 20 is basically an on-demand belt (film) heating method / pressure rotating body drive method (tensionless type) disclosed in JP-A-4-44075 to 44083, 4-204980-204984 and the like. The fixing device 20. Reference numeral 31 is a fixing belt assembly, and 32 is an elastic pressure roller as a pressure rotating body. The fixing nip portion N is formed by pressure welding of both the fixing belt assembly 31 and the pressure roller 32.

In the fixing belt assembly 31, 33 is a cylindrical (endless belt-shaped, sleeve-shaped) fixing belt as a heating rotating body, and is a flexible fixing belt (hereinafter, abbreviated as a belt). Reference numeral 34 denotes a belt guide member having heat resistance and rigidity (hereinafter, abbreviated as a guide member). The cross section of the guide member 34 has a substantially semicircular arc shape as shown in the figure. Reference numeral 35 denotes a ceramic heater (hereinafter abbreviated as a heater) as a heating source (heating body), which is fitted and fixed to the outer surface of the guide member 34 in a concave groove portion provided along the length of the member. It is done. The belt 33 is loosely fitted to the guide member 34 to which the heater 35 is attached.

Reference numeral 36 denotes a rigid pressure stay (hereinafter, abbreviated as stay) having a U-shaped cross section, which is arranged inside the guide member 34. At both left and right ends of the stay 36, there are arm portions 36a protruding toward the left and right outside. Reference numeral 37 denotes an end holder fitted to each of the arms 36a of the stay 36. Reference numeral 37a is a flange portion integrated with the end holder 37.

The belt 33 is usually a composite layer structure in which a heat-resistant resin belt or a metal belt is used as a base layer, and an elastic layer, a release layer, or the like is added thereto. The belt 33 is preferably a member that is thin, has flexibility, and has a high thermal conductivity and a low heat capacity as a whole.

The heater 35 is a thin planar heating body having a low heat capacity and having a longitudinal direction perpendicular to the moving direction of the paper P at the fixing nip portion N. The basic configuration is a heater substrate made of a ceramic material such as aluminum or alumina titrated, and an energized heat generating layer such as silver-palladium formed on the substrate surface. Since various types of ceramic heaters are known, detailed description thereof will be omitted.

The pressure roller 32 is obtained by providing an elastic layer 32b such as silicone rubber on the core metal 32a to reduce the hardness. In order to improve the surface property, a fluororesin layer 32c such as PTFE, PFA, FEP or the like may be further provided on the outer periphery. The pressure roller 32 is arranged by holding the left and right ends of the core metal 32a freely (rotatably) between the left and right side plates 38L and 38R of the frame 38 via a bearing member (support portion) 39. be. Here, the frame 38 extends in the longitudinal direction (width direction) of the fixing device 20 as shown in FIGS. 3 and 4.

The fixing belt assembly 31 is arranged in parallel with the pressure roller 32 so that the heater 35 side faces each other. Then, the left and right end holders 37 are respectively urged in the axial direction of the pressure roller 32 by a predetermined force F (FIG. 4) by a pressure mechanism (not shown). As a result, the surface of the heater 35 is brought into pressure contact with the pressure roller 32 via the belt 33. At this time, the pressure roller 32 is pressure-welded against the elasticity of the elastic layer 32b. As a result, the fixing nip portion N required for heat fixing is formed. The fixing nip portion N has a predetermined width with respect to the paper transport direction.

The pressurizing mechanism has a pressure releasing mechanism, and has a configuration in which the pressurizing is released at the time of jam processing or the like, and the paper P sandwiched between the fixing nip portions N can be easily removed.

Reference numerals 40 and 41 are an entrance guide (first guide member) and a fixing paper ejection roller assembled to the frame 38. The entrance guide 40 plays a role of guiding the paper P so that the paper P that has passed through the secondary transfer nip portion and is guided by the vertical transfer path 19 and has entered the fixing device 20 is accurately guided by the fixing nip portion N. ..

G is a drive gear fixed to one end of the core metal 32a of the pressure roller 32. By transmitting the rotational force of the fixing motor M1 to the gear G via a power transmission mechanism (not shown), the pressurizing roller 32 is rotationally driven in the clockwise direction of the arrow in FIG. Due to the rotational drive of the pressure roller 32, a rotational force acts on the belt 33 due to the frictional force between the pressure roller 32 and the outer surface of the belt 33 at the nip portion N. As a result, the belt 33 rotates the outer circumference of the guide member 34 in the counterclockwise direction of the arrow while the inner surface thereof slides in close contact with the heater 35 at the nip portion N (pressurized roller drive method).

The belt 33 rotates at a peripheral speed substantially corresponding to the rotational peripheral speed of the pressure roller 32. The left and right flange portions 37a serve to receive and regulate the movement of the belt end portion on the side when the rotating belt 33 moves to the left or right along the length of the guide member 34. Grease (lubricant) is applied to the inner surface of the belt 33 to ensure the slidability of the belt 33 with respect to the heater 35 and the guide member 34.

The paper P introduced into the fixing nip portion N is sandwiched and conveyed by the rotation of the pressure roller 32 and the belt 33. In this embodiment, the paper P is transported by the so-called central reference transport centered on the paper. That is, for any size of paper that can be passed through the device, the central portion in the paper width direction passes through the central portion in the longitudinal direction of the belt 33. S is the paper center pass reference line (virtual line).

TH1 and TH2 are two main and sub thermistors as first and second temperature detecting means. The main thermistor TH1 is arranged in contact with the back surface of the heater at a substantially central position in the longitudinal direction of the heater 35 so as to detect the temperature of the heater portion that serves as the paper passing portion for paper of any width. ..

The sub-thermistor TH2 is provided on the inner surface of the belt 33 so as to detect the temperature of the belt portion corresponding to the non-passing portion when the paper having a width smaller than the maximum width paper that can be passed through the apparatus is passed through the apparatus. They are arranged in elastic contact. Specifically, the sub-thermistor TH2 is supported by a free end portion of a leaf spring-shaped elastic support member 42 whose base is fixed to the guide member 34. The sub thermistor TH2 is arranged so as to be elastically contacted with the inner surface of the belt 33 by the elasticity of the elastic support member 42.

The heater 35 is energized from the heater drive circuit 92 (FIG. 5) as a power supply unit to the energized heat generating layer provided on the heater substrate surface, so that the energized heat generating layer generates heat and the heater 35 generates heat. The temperature rises rapidly over the entire effective heat generation width in the longitudinal direction of the heater. The heater temperature is detected by the main thermistor TH1, and electrical information regarding the heater temperature is input to the control circuit unit 100 via the A / D converter 81. Further, the temperature of the belt 33 is detected by the sub thermistor TH2, and electrical information regarding the belt temperature is input to the control circuit unit 100 via the A / D converter 82.

The control circuit unit 100 determines the temperature control content of the heater 35 based on the outputs of the main thermistor TH1 and the sub thermistor TH2, and controls the energization from the heater drive circuit 92 to the heater 35. That is, the temperature of the heater 35 is controlled so that the heater temperature detected by the main thermistor TH1 is maintained at a predetermined fixing temperature.

Then, the control circuit unit 100 controls the fixing motor drive circuit 91 based on the print signal from the external host device 200 or another control signal, and starts the rotational drive of the pressurizing roller 32. Further, the heater drive circuit 92 is controlled to start the heat-up of the heater 35. In a state where the rotation speed of the belt 33 becomes steady and the temperature of the heater 35 rises to a predetermined level, the paper P carrying the unfixed toner image t on the fixing nip portion N is guided along the entrance guide 40 from the image forming portion side. Will be introduced. The toner image supporting surface side of the paper P faces the belt 33.

The paper P comes into close contact with the heater 35 at the fixing nip portion N via the belt 33, and moves and passes through the fixing nip portion N together with the belt 33. In the process of passing through the movement, heat is applied to the paper P by the belt 33 heated by the heater 35, and the toner image t is heated and fixed on the paper surface. The paper P that has passed through the fixing nip portion N is separated from the surface of the belt 33 and discharged and conveyed.

(3) Open / close door 44
An opening 30B (FIG. 6A) is provided on the right side of the apparatus main body 30A of the printer 30. Here, the right side surface is the right side surface when the printer 30 is viewed from the front. Then, an opening / closing door (opening / closing member) 44 capable of having a closing position (closing position) 44A (FIG. 2) for predeterminedly closing the opening 30B and an opening position 44B (FIG. 6A) for predeterminedly opening the opening 30B is provided. ing. The opening / closing door 44 is made of resin for weight reduction.

As will be described later, the post-transcriptional guide 43 (second guide member) moves in conjunction with the opening / closing operation of the opening / closing door 44. Specifically, when the opening / closing door 44 is opened from the closing position 44A to the opening position 44B, the post-transcriptional guide 43 also opens together with the opening / closing door 44. That is, the apparatus main body 30A of the printer 30 is movably provided with an opening / closing door 44 so that the paper transport path including the vertical transport path 19 can be opened.

On the other hand, the fixing device 20 and the entrance guide 40 remain in the device main body 30A even when the opening / closing door 44 is positioned at the opening position 44B.

The manual feed tray 17 is arranged on the outer surface side of the opening / closing door 44. When not in use, the tray 17 can stand up and rotate around the hinge portion 17a on the lower side of the tray and can be stored with respect to the outer surface portion of the opening / closing door 44 (FIG. 6A).

When the paper P during image formation is jammed, the user (operator) operates the opening / closing door 44 to remove the paper P from the printer 30 to open the paper transport path including the vertical transport path 19.

In order to open the vertical transport path 19, the user first unlocks the opening / closing door 44 with respect to the device main body 30A by the door lock portion (not shown). After that, the opening / closing door 44 is tilted and rotated from the closing position 44A in FIG. 2 centering on the hinge portion 45 at the lower side of the door to the opening position 44B on the right outer side of the apparatus main body 30A as shown in FIG. 6A. When the opening / closing door 44 is rotated to the tilt angle of the predetermined opening position 44B, the rotation is restricted by a stopper (not shown) so that the opening / closing door 44 is not opened any more, and is held at the predetermined opening position.

Inside the opening / closing door 44, a reconveying path 24, a right roller of the resist roller pair 16, a secondary transfer roller 11, and an upper roller of the paper ejection roller pair 22 are arranged. Further, the right side guide of the guides constituting the transport path, the vertical transport path 15, the vertical transport path 19, and the transport path 21 from the cassette paper feed units 13A, 13B, and 13C to the vertical transport path 15, is the opening / closing door 44. It is arranged inside.

Therefore, when the opening / closing door 44 is opened, the paper transport path from each cassette feeding unit 13A, 13B, 13C to the paper ejection roller pair 22 is opened except for the inside of the fixing device 20. As a result, in the open space between the open / close door 44 and the apparatus main body 30A, the user can re-transfer and re-transfer the paper from the paper feed rollers 14 of the cassette paper feed units 13A, 13B, and 13C to the paper discharge rollers vs. 22. The path 24 can be accessed to easily perform jam processing. The paper sandwiched between the fixing nip portions N in the fixing device 20 can be easily removed from the jam paper by releasing the pressurization of the pressurizing mechanism by the pressure releasing mechanism.

After removing the jammed paper, the user raises and rotates the opened opening / closing door 44 around the hinge portion 45 in the direction opposite to that at the time of opening, and closes the opened opening / closing door 44 with respect to the apparatus main body 30A. By sufficiently closing the paper transport path, the paper transport path is formed again, and at the same time, the door lock portion locks the door 44 to prevent the opening / closing door 44 from opening at the closing position 44A, and the printer 30 returns to a state in which the image forming operation is possible. ..

The opening / closing method of the opening / closing door 44 with respect to the apparatus main body 30A is not limited to the above example. For example, as shown in FIG. 6B, the opening / closing operation can be performed by laterally moving (sliding) the opening / closing door 44 in the horizontal direction with respect to the device main body 30A by using a slide member 46 such as an accuride rail. That is, the slide member 46 is a member capable of sliding the opening / closing door 44 in a direction orthogonal to the paper transport surface.

(4) Vertical transport path 19
A part of the transport surface (recording material transport surface) forming the vertical transport path 19 from the secondary transfer unit A to the fixing device 20 is configured as shown in FIGS. 3 and 7. That is, it is formed by an inlet guide (first guide member) 40 attached to the frame (support member) 38 of the fixing device 20 and a post-transcriptional guide (second guide member) 43 attached to the opening / closing door 44. After transfer, the guide 43 moves in conjunction with the opening / closing movement of the opening / closing door 44. FIG. 7 shows the positional relationship between the entrance guide 40 and the post-transcriptional guide 43 as viewed from the left side of the printer.

Here, the left side of the printer is the left side when the printer 30 is viewed from the front. The front side of the drawing of FIG. 7 is a part of the transport surface forming the vertical transport path 19, and the paper P is transported in the upward direction of the drawing of FIG. 7 (direction of arrow a) through the inside of the region R. Here, the region R is a region (paper transport region) in which the paper is transported on the transport surface formed by the post-transcriptional guide 43 and the inlet guide 40.

Here, the inlet guide 40 is made of a heat-resistant resin such as PBT or LCP, and is attached to the metal frame 38 by the mounting portion 40a. That is, the frame 38 is a support plate that supports the entrance guide 40.

In this embodiment, the frame 38 is a cold-rolled steel plate (metal plate). As described above, the frame 38 extends in the longitudinal direction (width direction) of the fixing device 20, and the pressure rollers 32 are rotatably supported by the left and right side plates 38L / 38R connected to the frame 38. ing.

The mounting portion 40a is formed by forming a part of the inlet guide 40 in a hook shape, and is positioned by fitting the mounting portion 40a into the hole of the frame 38. Further, the entrance guide 40 is fixed to the frame 38 by screwing. In order to improve the transport quality against wrinkles and the like, the position of the downstream end of the post-transcriptional guide 43 in the paper transport direction a should be as close as possible to the guide surface of the inlet guide 40, and the posture of the paper P during transport should be adjusted. It is desirable to stabilize.

However, as the opening / closing door 44 is opened / closed, the post-transcriptional guide 43 assembled on the opening / closing door 44 moves, whereas the entrance guide 40 assembled on the fixing device 20 side does not move. Variations are likely to occur in the relative positions of 40. Therefore, if the two guides 43 and 40 are brought too close to each other, dynamic interference may occur.

For this reason, as shown in FIG. 7, comb tooth-shaped portions 40b and 43a are provided in a part of the post-transcriptional guide 43 and the inlet guide 40 including the paper transport area R. Then, the comb teeth overlap each other while meshing with each other, so that the guides 43 and 40 are substantially continuous 1 while avoiding interference between the transport surfaces of the post-transcriptional guide 43 and the inlet guide 40. It is configured to form two transport surfaces (recording material transport surfaces). This is intended to improve the transport quality.

The overlap means that the comb tooth-shaped portions overlap when both guides 43 and 40 are viewed from a direction (width direction) orthogonal to the paper transport direction a on the transport surface.

More specifically, as shown in FIG. 7, the post-transfer guide 43 has a convex portion (reference numeral 43a in FIG. 7) extending toward the downstream side in the paper transport direction a (that is, toward the fixing nip portion N). Has. On the other hand, the inlet guide 40 has a recess (a portion between reference numerals 40b and reference numeral 40b in FIG. 7) that is recessed toward the downstream side in the paper transport direction a. The concave portions of the inlet guide 40 are provided at positions so that the convex portions of the guide 43 after transfer can be accommodated. That is, since the convex portion of the post-transfer guide 43 is located in the concave portion of the inlet guide 40, both guides 43 and 40 form a series of one transport surface (recording material transport surface) that is substantially continuous.

Further, as shown in FIG. 7, the inlet guide 40 is provided with a plurality of concave portions, and the post-transcriptional guide 43 is provided with a plurality of convex portions. Each of the plurality of convex portions of the post-transfer guide 43 is located in each of the concave portions of the inlet guide 40, so that the comb teeth overlap each other so as to mesh with each other.

In other words, as shown in FIG. 7, the inlet guide 40 has a plurality of convex portions (reference numeral 40b in FIG. 7) extending toward the upstream side in the paper transport direction a (that is, toward the transfer nip portion A side). ).

On the other hand, the post-transfer guide 43 has a plurality of recesses (a portion between reference numerals 43a and reference numeral 43a in FIG. 7) that are recessed toward the upstream side in the paper transport direction a. The recesses of the post-transcriptional guide 43 are provided at positions so that the convex portions of the inlet guide 40 can be accommodated. That is, since the convex portion of the inlet guide 40 is located in the concave portion of the post-transcriptional guide 43, both guides 43 and 40 form a series of one transport surface (recording material transport surface) that is substantially continuous.

Further, as shown in FIG. 7, the inlet guide 40 is provided with a plurality of convex portions, and the post-transcriptional guide 43 is provided with a plurality of concave portions. Each of the plurality of convex portions of the entrance guide 40 is located in each of the concave portions of the post-transcriptional guide 43, so that the comb teeth overlap each other so as to mesh with each other.

The inlet guide 40 and the post-transfer guide 43 overlap so that the concave portion of the inlet guide 40 and the convex portion of the post-transfer guide 43 (or the convex portion of the inlet guide 40 and the concave portion of the post-transfer guide 43) mesh with each other. As long as one transport surface is formed by the above, the following configuration may be used. For example, a part of the plurality of concave portions of the inlet guide 40 in the paper transport region does not mesh with the convex portion of the post-transfer guide 43 (that is, there is no convex portion at the position of the corresponding post-transfer guide 43). You may.

Even in this case, the remaining concave portion of the inlet guide 40 meshes with the convex portion of the post-transfer guide 43. Similarly, for example, a part of the plurality of concave portions of the post-transcriptional guide 43 may not mesh with the convex portion of the inlet guide 40.

However, in a configuration in which a plurality of guides (conveying members) 43 and 40 mesh in a comb-teeth shape, due to a user's erroneous operation or the like while some guides move to open the transport path due to a jam processing operation. Paper may get stuck in the overlapping area. In such a case, when some of the moving guides return from the open position to the closed position again, the paper may be caught in the overlapping area between the plurality of guides described above. Then, the comb teeth could not be engaged with each other, and the guide subjected to the force through the paper may be deformed or damaged.

This will be described with reference to the schematic diagram of FIG. FIG. 8 shows an example of a change in the relative positions of the inlet guide 40 and the post-transcriptional guide 43 during jam processing of the paper P and the interference of the paper P that may occur with the change when viewed from the front direction of the printer body. That is, the state when both guides 43 and 40 are viewed from the direction (width direction) orthogonal to the paper transport direction a on the transport surface is shown. (A) and (b) are diagrams when there is no paper P, and (c), (d), (e), and (f) are diagrams when the paper P is jammed.

First, using (a) and (b), changes in the relative positions of the two guides 43 and 40 due to the movement of the opening / closing door 44 will be described. As shown in (a), when the opening / closing door 44 is closed, the inlet guide 40 and the post-transcriptional guide 43 overlap each other to form a transport surface of the vertical transport path 19.

On the other hand, as shown in (b), in the state where the opening / closing door 44 is opened, the post-transfer guide 43 moves together with the opening / closing door 44, so that the inlet guide 40 and the post-transfer guide 43 do not overlap with each other. Along with this, the transport surface forming the vertical transport path 19 is opened. Here, the fixing device 20 and the entrance guide 40 do not move together with the opening / closing door 44. As a result, when a paper jam occurs, the user can access the transport path 19 portion.

Next, using (c), (d), and (e), an example in which the paper P interferes due to a change in the relative positions of the two guides 43 and 40 due to the movement of the opening / closing door 44 will be described. As shown in (c), when the paper P is jammed by the fixing device 20 and the paper P stays in the vertical transport path 19, it is necessary to remove the jammed paper.

Therefore, as shown in (d), the opening / closing door 44 is moved to open the vertical transport path 19, and the paper P is pulled out by holding the rear end to remove the paper P. At this time, in the state where the opening / closing door 44 is opened, the rear end of the paper P moves to a position interposed between the inlet guide 40 and the transfer guide 43, for example, depending on the operation of the user during the jam processing of the paper P. Can be done.

Further, as shown in (e), when the opening / closing door 44 is closed from the state where the paper P is present at a position interposed between the entrance guide 40 and the transfer guide 43, the comb teeth of the entrance guide 40 and the transfer guide 43 are used. Paper P interferes with the shape portion. Therefore, the inlet guide 40 and the post-transcriptional guide 43 stop in a state where the paper P is caught between the comb tooth shapes 40b and 43a. When a force for further closing the opening / closing door 44 is further applied from there, the force propagates from the transfer guide 43 through the paper bitten into the inlet guide 40, and the attachment portion 40a of the inlet guide 40 may be deformed or damaged.

(F) shows the mechanism of force propagation to the mounting portion 40a of the inlet guide 40 when the paper P is interposed between the inlet guide 40 and the post-transcriptional guide 43. When the paper P interferes between the guides 40 and 43, the inlet guide 40 and the post-transfer guide 43 form a contact point Q via the paper P. The force for closing the opening / closing door 44 is applied from the transfer guide 43 to the inlet guide 40 via the contact point Q (force point). The entrance guide 40 that has received the force F1 receives the moment M with the entrance guide 40 or the edge portion 47 of the frame 38 as a fulcrum. As a result, the mounting portion 40a becomes the point of action and receives the force F2.

Generally, the fracture of the resin member is caused by tensile stress. Therefore, if the direction of the force F2 is the direction in which the inlet guide 40 is pressed against the mounting surface of the frame 38, the mounting portion 40a becomes compressive stress and fracture is unlikely to occur. On the contrary, when the direction of the force F2 is the direction of pulling the inlet guide 40 away from the mounting surface of the frame 38, the mounting portion 40a becomes a tensile stress and fracture may occur.

The compression / tension direction of the force F2 is determined by the presence or absence of an intersection of a half straight line L1 extending the force F1 starting from the contact point Q and a line L2 passing through the mounting portion 40a starting from the edge portion 47. When L1 and L2 form an intersection, the force F2 is in the compression direction, and when L1 and L2 do not form an intersection, the force F2 is in the tensile direction. In the configuration of the reference example shown in (f), L1 and L2 do not form an intersection, and the force F2 becomes a tensile stress, which may cause the mounting portion 40a to break.

Therefore, in such a configuration in which the plurality of guides (conveying members) 40 and 43 mesh in a comb-teeth shape, it is required to suppress damage to the guides due to the paper being pinched by a simple configuration. FIG. 1 shows a guide configuration of this embodiment to realize this. In the guide shape based on the configuration shown in FIG. 1A, L1 and L2 form an intersection, and the force F2 becomes a compressive stress, so that the guide can be suppressed from breaking.

Using (b) of FIG. 1, a specific shape of the entrance guide 40 (b) for forming an intersection between L1 and L2 as shown in (a) will be described. FIG. 1 is a projection drawing of the inlet guide 40, the post-transcriptional guide 43, and the frame 38 as viewed from a direction (width direction) orthogonal to the paper transport direction a on the transport surfaces of both guides 40 and 43.

The entrance guide 40 has a shape including an arc-shaped curved surface Qa-Qb whose center is O, and forms a contact point (virtual contact point in the projection drawing) with the post-transcriptional guide 43 on the curved surface Qa-Qb.

That is, the inlet guide 40 has a convex curved surface Qa-Qb (curved surface shape portion) on the back side of the transport surface in the projection plane viewed from the direction (width direction) orthogonal to the paper transport direction a on the transport surface. The entrance guide 40 has a plurality of curved surfaces Qa-Qb (curved surface shape portions) in the width direction. As shown in FIG. 3, in the printer 30, the support surface on which the frame 38 supports the entrance guide 40 is provided above the curved surface Qa-Qb (curved surface shape portion) in the direction of gravity.

Here, the movement locus of the post-transcriptional guide 43 changes due to the backlash between the parts constituting the opening / closing door 44 and the variation in the dimensional tolerance, but a contact point is always formed between Qa and Qb of the curved surface Qa-Qb. The region of the curved surface Qa-Qb is defined as described above. Here, the contact point in the movement locus of the post-transcriptional guide 43 refers to the next point on the projection plane. That is, it is a point at the edge of the inlet guide 40 that first overlaps with the movement locus of the convex portion of the post-transcriptional guide 43 on the projection surface.

In general, when friction is ignored, the direction of the force applied when a point load is applied to the curved surface Qa-Qb is the normal direction at the contact point. That is, the direction of the force applied when the point load is applied to the curved surface Qa-Qb is the normal direction with respect to the tangent line of the curved surface Qa-Qb when the contact point when the point load is applied is a virtual contact point.

Therefore, the direction of the force F1 applied when the contact point is formed on the curved surface Qa-Qb faces the center O of the arc.

Here, the curved surface QaQb is determined so that the half straight line L1a which is an extension of the force F1a when Qa is a contact point and the half straight line L1b which is an extension of the force F1b when Qb is a contact point each intersect with L2. As a result, L1 and L2 form an intersection on the intersection where L1a and L1b form L2, respectively, regardless of where the contact point is on the curved surface Qa-Qb.

By providing such a curved surface Qa-Qb on the entrance guide 40, the movement locus of the post-transcriptional guide 43 accompanying the closing operation of the opening / closing door 44 and the force applied to the entrance guide 40 are as shown in FIG. 1A. .. That is, the entrance guide 40 has a curved surface Qa-Qb (curved surface shape portion) at a position where it first overlaps with the movement locus of the convex portion of the post-transcriptional guide 43 accompanying the closing operation of the opening / closing door 44.

Therefore, the movement locus of the convex portion of the post-transcriptional guide 43 and the inlet guide 40 and the frame 38 at the position having the curved surface Qa-Qb are oriented in a direction orthogonal to the paper transport direction a on the transport surfaces of both guides 40 and 43 ( The projection surface seen from the width direction) is as shown in FIG. 1 (a). On this projection surface, a point Q is a point of the entrance guide 40 that first starts to overlap with the movement locus of the convex portion of the post-transcriptional guide 43 accompanying the closing operation of the opening / closing door 44. The point Q is a point in the paper transport area P of the inlet guide 40 that first starts to overlap with the movement locus of the convex portion of the guide 43 after transfer.

At this point Q, when the opening / closing door 44 is closed with the paper P interposed between the inlet guide 40 and the post-transfer guide 43, the paper P is pressed by the post-transcription guide 43 and a force is applied to the inlet guide 40. It is a working point. When this point Q is used as a virtual contact point on the curved surface Qa-Qb (curved surface shape portion), a virtual tangent line on the curved surface Qa-Qb (curved surface shape portion) is drawn, and the line passes through the point Q and is relative to the tangent line. The normal line is the half straight line L1 shown in FIG. 1 (a).

Further, the line L2 is a line passing through the mounting portion 40a starting from the edge portion 47 of the frame 38 on the projection surface of FIG. 1A, and indicates the supporting surface of the frame 38 that supports the entrance guide 40.

Here, when the half straight line L1 which is a virtual normal intersects the support surface of the frame 38, that is, the entrance guide 40 on the opening / closing door 44 side by the frame 38 from the edge portion 47 of the frame 38 on the transport surface side. This is when the half straight line L1 intersects up to the support end 48 of the door. At this time, the force F2 applied to the mounting portion 40a becomes a compressive stress. As a result, when the opening / closing door 44 is closed with the paper P interposed between the inlet guide 40 and the post-transcriptional guide 43, the curved surface Qa-Qb (curved surface shape portion) of the entrance guide 40 exerts a force F1 from the paper P. Receive.

At this time, a moment M with the edge portion 47 of the frame 38 as a fulcrum acts on the entrance guide 40 in the direction of the arrow M in FIG. 1A due to the force F1 received by the curved surface Qa-Qb (curved surface shape portion). .. Since the force F2 applied to the mounting portion 40a becomes a compressive stress, damage to the inlet guide 40 can be suppressed.

If the half straight line L1, which is a virtual normal, extends to the side farther from the opening / closing door 44 (left side in FIG. 1A) than the edge portion 47 of the frame 38 of the frame and does not intersect the support surface. The following force acts on the entrance guide 40. That is, the moment with the edge portion 47 of the frame 38 as the fulcrum acts in the direction opposite to the arrow M in FIG. 1A, and the tensile stress acts on the mounting portion 40a. Therefore, it may lead to damage of the mounting portion 40a.

The above features are summarized below. The post-transfer guide 43 takes a first state in which the comb-shaped portion 43a does not overlap with the comb-shaped portion 40b of the inlet guide 40 when the opening / closing door 44 is open. The post-transcriptional guide 43 takes a second state in which the comb-shaped portion 43a overlaps the comb-shaped portion 40b of the inlet guide 40 when the opening / closing door 44 is in the closed position 44A.

The inlet guide 40 has at least a curved surface-shaped portion Qa-Qb on a paper non-conveying surface (recording material non-conveying surface) in a region where the comb-shaped portion 40b overlaps the comb-shaped portion 43a of the post-transfer guide 43. The overlap starts at the curved surface shape portion Qa-Qb. The profile of the curved surface shape portion Qa-Qb is characterized in that the normal L1a of the curved surface Qa at the overlap start point when the post-transcriptional guide 43 shifts from the first state to the second state passes through the frame 38.

As described above, even when the post-transcriptional guide 43 forms a contact point with the inlet guide 40 due to the variation in position, the force applied to the mounting portion 40a of the guide 40 is always compressed, and damage to the mounting portion 40a can be suppressed. It becomes.

<< Example 2 >>
In the first embodiment, on the projection surface shown in FIG. 1, a curved surface Qa-Qb is provided at a portion of the entrance guide 40 that first starts to overlap with the movement locus of the convex portion of the post-transcriptional guide 43 accompanying the closing operation of the opening / closing door 44. The configuration was explained.

In the second embodiment, as shown in FIG. 9, a configuration in which the inclined portion Qa-Qb is provided on the entrance guide 40 instead of the curved surface Qa-Qb of the first embodiment will be described. The configuration is the same as that of the first embodiment except that the inclined portion Qa-Qb is provided instead of the curved surface Qa-Qb. In the following, only the difference from the first embodiment will be described, and the description of the common configuration will be omitted.

FIG. 9 is a projection drawing of the inlet guide 40, the post-transcriptional guide 43, and the frame 38 as viewed from a direction (width direction) orthogonal to the paper transport direction a on the transport surfaces of both guides 40 and 43. The inlet guide 40 has a shape including the inclined portion Qa-Qb, and forms a contact point (virtual contact point in the projection drawing) with the post-transcriptional guide 43 on the inclined portion Qa-Qb. The entrance guide 40 has a plurality of inclined portions Qa-Qb in the width direction.

The inclined portions Qa-Qb extend toward the opening 30B side opened and closed by the opening / closing door 44 from the upstream side to the downstream side in the conveying direction of the paper P on the conveying surface of the inlet guide 40. That is, the inlet guide 40 has the inclined portions Qa-Qb on the back side of the transport surface in the projection plane viewed from the direction (width direction) orthogonal to the paper transport direction a on the transport surface. As shown in FIG. 3, in the printer 30, the support surface on which the frame 38 supports the entrance guide 40 is provided above the inclined portion Qa-Qb in the direction of gravity.

Here, the movement locus of the post-transcriptional guide 43 changes due to the backlash between the parts constituting the opening / closing door 44 and the variation in the dimensional tolerance, but a contact point is always formed between Qa and Qb of the inclined portions Qa-Qb. The region of the inclined portion Qa-Qb is defined so as to be so as to.

Here, the contact point in the movement locus of the post-transcriptional guide 43 refers to the next point on the projection plane. That is, it is a point at the edge of the inlet guide 40 that first overlaps with the movement locus of the convex portion of the post-transcriptional guide 43 on the projection surface.

Further, generally, when friction is ignored, the direction of the force applied when a point load is applied to the inclined portion Qa-Qb is the normal direction at the contact point. That is, the direction of the force applied when the point load is applied to the inclined portion Qa-Qb passes through the contact point when the point load is applied and is the normal direction with respect to the inclined portion Qa-Qb.

The normal to the inclined portion Qa-Qb shall be determined as follows. In the projection plane shown in FIG. 9, the contact point is the center, the position 1.0 mm above the center along the slope is defined as the point α, and the position 1.0 mm downward along the slope is defined as the point β. At this time, the line connecting the points α and β is defined as the inclination of the inclined portions Qa-Qb. On the projection surface, the line that passes through the contact point and is orthogonal to this inclination is defined as the normal line with respect to the inclination portion Qa-Qb.

In this embodiment, since the inclined portion Qa-Qb is a slope having a uniform inclination, the inclined portion Qa-Qb and the normal L1, the normals L1a, and L1b are orthogonal to each other in FIG.

Here, the inclined portion Qa- so that the half straight line L1a obtained by extending the force F1a when Qa is used as the contact point and the half straight line L1b extending the force F1b when Qb is used as the contact point intersect with L2, respectively. Determine Qb. As a result, L1 and L2 form an intersection between the intersections where L1a and L1b form with L2, respectively, wherever there is a contact point on the inclined portion Qa-Qb.

By providing the entrance guide 40 with such an inclined portion Qa-Qb, the movement locus of the post-transcriptional guide 43 accompanying the closing operation of the opening / closing door 44 and the force applied to the entrance guide 40 are as shown in FIG. 9A. Become. That is, the entrance guide 40 has an inclined portion Qa-Qb at a position where it first overlaps with the movement locus of the convex portion of the post-transcriptional guide 43 accompanying the closing operation of the opening / closing door 44. Therefore, the movement locus of the convex portion of the post-transfer guide 43 and the inlet guide 40 and the frame 38 at the position having the inclined portions Qa-Qb are orthogonal to the paper transport direction a on the transport surfaces of both guides 40 and 43. The projection plane viewed from the direction (width direction) is as shown in FIG. 9A.

On this projection surface, a point Q is a point of the entrance guide 40 that first starts to overlap with the movement locus of the convex portion of the post-transcriptional guide 43 accompanying the closing operation of the opening / closing door 44. The point Q is a point in the paper transport area P of the inlet guide 40 that first starts to overlap with the movement locus of the convex portion of the guide 43 after transfer. At this point Q, when the opening / closing door 44 is closed with the paper P interposed between the inlet guide 40 and the post-transfer guide 43, the paper P is pressed by the post-transcription guide 43 and a force is applied to the inlet guide 40. It is a working point. The normal line passing through this point Q and with respect to the inclined portion Qa-Qb is the normal line L1 shown in FIG. 9A.

Further, the line L2 is a line passing through the mounting portion 40a starting from the edge portion 47 of the frame 38 on the projection surface of FIG. 9A, and indicates the supporting surface of the frame 38 that supports the entrance guide 40.

Here, when the normal line L1 intersects the support surface of the frame 38, that is, between the edge portion 47 of the frame 38 on the transport surface side and the support end 48 of the entrance guide 40 on the opening / closing door 44 side by the frame 38. When the normal L1 intersects at. At this time, the force F2 applied to the mounting portion 40a becomes a compressive stress. As a result, when the opening / closing door 44 is closed with the paper P interposed between the inlet guide 40 and the post-transcriptional guide 43, the inclined portions Qa-Qb of the inlet guide 40 receive the force F1 from the paper P.

At this time, a moment M with the edge portion 47 of the frame 38 as a fulcrum acts on the entrance guide 40 in the direction of the arrow M in FIG. 9A due to the force F1 received by the inclined portions Qa-Qb. Since the force F2 applied to the mounting portion 40a becomes a compressive stress, damage to the inlet guide 40 can be suppressed.

If the normal line L1 extends to the side farther from the opening / closing door 44 (left side in FIG. 9A) than the edge portion 47 of the frame 38 of the frame and does not intersect the support surface, the entrance guide 40 has the following: Power works like this. That is, the moment with the edge portion 47 of the frame 38 as the fulcrum acts in the direction opposite to the arrow M in FIG. 9A, and the tensile stress acts on the mounting portion 40a. Therefore, it may lead to damage of the mounting portion 40a.

30 ... Image forming device, 30A ... Device body, 30B ... Opening, 44 ... Opening and closing member, 44A ... Closed position, 44B ... Open position, 40 ... First guide, 40b ... Comb shape Part, 38 ... Support member, 43 ... Second guide, 43a ... Comb-shaped part, Qa-Qb ... Curved part, L1a ... Normal, P ... Recording material, t ... Toner image

Claims (18)

At the transfer nip, a transfer unit that transfers the toner image to the recording material, and
At the fixing nip part, a fixing part for fixing the toner image formed by the transfer part to the recording material, and a fixing part.
An opening provided in the main body of the apparatus for accommodating the transfer portion and the fixing portion,
An opening / closing member capable of having a closing position for closing the opening and an opening position for opening the opening.
A first guide member and a second guide member that form a transport surface for a recording material from the transfer nip portion to the fixing nip portion in a state where the opening / closing member is in a closed position.
The transport surface has a support surface that extends in a width direction that is orthogonal to the transport direction of the recording material and supports the first guide member over the width direction, and the support surface has the first support surface. Has a metal plate to which the guide member is fixed,
When the opening / closing member is in the open position, the first guide member is located in the apparatus main body.
The second guide member moves together with the opening / closing member in conjunction with the opening / closing operation of the opening / closing member.
In the first guide member and the second guide member, the convex portion of the second guide member becomes the first guide member as the opening / closing member moves from the open position to the closed position. By being located in the recess of, the transport surface is formed.
When the opening / closing member is in the closed position, the first guide member is located on the downstream side of the second guide member in the transport direction of the recording material.
When the transport surface is viewed when the opening / closing member is in the closed position, the recess of the first guide member is recessed toward the downstream side in the transport direction, and the convex of the second guide member. The portion protrudes toward the downstream side in the transport direction.
When viewed from the width direction, the first guide member first overlaps with the movement locus of the convex portion of the second guide member due to the closing operation of the opening / closing member among the first guide members. It has a convex curved surface shape at the position where it is
A projection surface when the movement locus of the convex portion of the second guide member and the first guide member and the metal plate at a position having the curved surface shape portion in the width direction are viewed from the width direction. In the movement locus of the convex portion of the second guide member accompanying the closing operation of the opening / closing member, a point at which the curved surface shape portion starts to overlap is set as a point Q, and the point Q is set as a virtual contact point. When the normal line to the virtual tangent line of the curved surface shape portion is set to the normal line L, the curved surface shape portion is provided so that the normal line L intersects the support surface of the metal plate. An image forming apparatus as a feature. The image forming apparatus according to claim 1, wherein the fixing nip portion is provided above the transfer nip portion in the direction of gravity. The image forming apparatus according to claim 1 or 2, wherein the support surface of the metal plate is provided above the curved surface shape portion in the direction of gravity. The fixing portion has a first rotating body and a second rotating body forming the fixing nip portion.
Any one of claims 1 to 3, wherein support portions for rotatably supporting both ends of the first rotating body are provided at both ends of the metal plate in the width direction. The image forming apparatus according to. The image forming apparatus according to any one of claims 1 to 4, wherein the first guide member has a plurality of curved surface-shaped portions in the width direction. The first guide member has a second recess.
When the transport surface is viewed when the opening / closing member is in the closed position, the second recess is recessed toward the downstream side in the transport direction.
The second guide member has a second convex portion located in the second concave portion as the opening / closing member moves from the open position to the closed position.
The image forming apparatus according to any one of claims 1 to 5, wherein the second convex portion projects toward the downstream side in the transport direction. A claim characterized in that the opening / closing member has a hinge portion for fixing the opening / closing member in the width direction, and the opening / closing member can be positioned at the closed position and the open position by being rotated around the hinge portion. Item 6. The image forming apparatus according to any one of Items 1 to 6. The opening / closing member has a slide member that can slide and move the opening / closing member in a direction orthogonal to the transport surface, and the opening / closing member is positioned at the closed position and the open position by being slidably moved along the slide member. The image forming apparatus according to any one of claims 1 to 6, wherein the image forming apparatus can be used. At the transfer nip, a transfer unit that transfers the toner image to the recording material, and
At the fixing nip part, a fixing part for fixing the toner image formed by the transfer part to the recording material, and a fixing part.
An opening provided in the main body of the apparatus for accommodating the transfer portion and the fixing portion,
An opening / closing member capable of having a closing position for closing the opening and an opening position for opening the opening.
A first guide member and a second guide member that form a transport surface for a recording material from the transfer nip portion to the fixing nip portion in a state where the opening / closing member is in a closed position.
The transport surface has a support surface that extends in a width direction that is orthogonal to the transport direction of the recording material and supports the first guide member over the width direction, and the support surface has the first support surface. Has a metal plate to which the guide member is fixed,
When the opening / closing member is in the open position, the first guide member is located in the apparatus main body.
The second guide member moves together with the opening / closing member in conjunction with the opening / closing operation of the opening / closing member.
In the first guide member and the second guide member, the convex portion of the second guide member becomes the first guide member as the opening / closing member moves from the open position to the closed position. By being located in the recess of, the transport surface is formed.
When the opening / closing member is in the closed position, the first guide member is located on the downstream side of the second guide member in the transport direction of the recording material.
When the transport surface is viewed when the opening / closing member is in the closed position, the recess of the first guide member is recessed toward the downstream side in the transport direction, and the convex of the second guide member. The portion protrudes toward the downstream side in the transport direction.
When viewed from the width direction, the first guide member first overlaps with the movement locus of the convex portion of the second guide member due to the closing operation of the opening / closing member among the first guide members. It has an inclined portion extending toward the opening side from the upstream side to the downstream side in the transport direction.
In a projection plane when the movement locus of the convex portion of the second guide member and the first guide member and the metal plate at a position having the inclined portion in the width direction are viewed from the width direction. A point Q is a point in the movement locus of the convex portion of the second guide member accompanying the closing operation of the opening / closing member, which starts to overlap with the inclined portion, passes through the point Q, and is orthogonal to the inclined portion. An image forming apparatus characterized in that the inclined portion is provided so that the normal line L intersects the support surface of the metal plate when the line is a normal line L. The image forming apparatus according to claim 9, wherein the fixing nip portion is provided above the transfer nip portion in the direction of gravity. The image forming apparatus according to claim 9 or 10, wherein the support surface of the metal plate is provided above the inclined portion in the direction of gravity. The fixing portion has a first rotating body and a second rotating body forming the fixing nip portion.
Any one of claims 9 to 11, wherein support portions for rotatably supporting both ends of the first rotating body are provided at both ends of the metal plate in the width direction. The image forming apparatus according to. The image forming apparatus according to any one of claims 9 to 12, wherein the first guide member has a plurality of inclined portions in the width direction. The first guide member has a second recess.
When the transport surface is viewed when the opening / closing member is in the closed position, the second recess is recessed toward the downstream side in the transport direction.
The second guide member has a second convex portion located in the second concave portion as the opening / closing member moves from the open position to the closed position.
The image forming apparatus according to any one of claims 9 to 13, wherein the second convex portion projects toward the downstream side in the transport direction. It has a hinge portion that fixes the opening / closing member in the width direction.
The image forming apparatus according to any one of claims 9 to 14, wherein the opening / closing member can be positioned at the closed position and the open position by being rotated around the hinge portion. It has a slide member capable of sliding the opening / closing member in a direction orthogonal to the transport surface.
The image forming apparatus according to any one of claims 9 to 14, wherein the opening / closing member can be positioned at the closed position and the open position by being slid along the slide member. An image forming part that forms a toner image on the recording material at the transfer nip part,
At the fixing nip part, a fixing part for fixing the toner image formed by the image forming part to the recording material, and a fixing part.
An opening provided in the main body of the apparatus for accommodating the image forming portion and the fixing portion, and
An opening / closing member capable of having a closing position for closing the opening and an opening position for opening the opening.
A first guide member and a second guide member that form a transport surface for a recording material from the transfer nip portion to the fixing nip portion in a state where the opening / closing member is in a closed position .
Extending in a width direction orthogonal to the conveying direction of the recording material relates before Symbol conveying surface, said first guide member having a support surface for supporting across the width direction, the first to the support surface With a metal plate to which the guide member is fixed,
When the opening / closing member is in the open position, the first guide member is located in the apparatus main body.
The second guide member moves together with the opening / closing member in conjunction with the opening / closing operation of the opening / closing member.
In the first guide member and the second guide member, the convex portion of the first guide member is the second guide as the opening / closing member moves from the open position to the closed position. By moving the second guide member so as to be located in the recess of the member, the transport surface is formed.
When the opening / closing member is in the closed position, the first guide member is located on the downstream side of the second guide member in the transport direction of the recording material.
When the transport surface is viewed when the opening / closing member is in the closed position, the convex portion of the first guide member projects toward the upstream side in the transport direction, and the second guide member said. The recess is recessed toward the upstream side in the transport direction.
When viewed from the width direction, the first guide member is convex to a position where it first overlaps with the movement locus of the second guide member accompanying the closing operation of the opening / closing member. Has a curved surface shape
The opening and closing of the movement locus of the second guide member and the opening and closing of the first guide member and the metal plate at a position having the curved surface shape portion in the width direction on a projection surface when viewed from the width direction. The point Q of the movement locus of the second guide member accompanying the closing operation of the member that starts to overlap with the curved surface shape portion is defined as a point Q, and the virtual contact point of the curved surface shape portion is virtual. An image forming apparatus characterized in that the curved surface shape portion is provided so that the normal line L intersects the support surface of the metal plate, where the normal line to the tangent line is the normal line L. An image forming part that forms a toner image on the recording material at the transfer nip part,
At the fixing nip part, a fixing part for fixing the toner image formed by the image forming part to the recording material, and a fixing part.
An opening provided in the main body of the apparatus for accommodating the image forming portion and the fixing portion, and
An opening / closing member capable of having a closing position for closing the opening and an opening position for opening the opening.
A first guide member and a second guide member that form a transport surface for a recording material from the transfer nip portion to the fixing nip portion in a state where the opening / closing member is in a closed position.
The transport surface has a support surface that extends in a width direction that is orthogonal to the transport direction of the recording material and supports the first guide member over the width direction, and the support surface has the first support surface. Has a metal plate to which the guide member is fixed,
When the opening / closing member is in the open position, the first guide member is located in the apparatus main body.
The second guide member moves together with the opening / closing member in conjunction with the opening / closing operation of the opening / closing member.
In the first guide member and the second guide member, the convex portion of the first guide member is the second guide as the opening / closing member moves from the open position to the closed position. By moving the second guide member so as to be located in the recess of the member, the transport surface is formed.
When the opening / closing member is in the closed position, the first guide member is located on the downstream side of the second guide member in the transport direction of the recording material.
When the transport surface is viewed when the opening / closing member is in the closed position, the convex portion of the first guide member projects toward the upstream side in the transport direction, and the second guide member said. The recess is recessed toward the upstream side in the transport direction.
When viewed from the width direction, the first guide member is located at a position where it first overlaps with the movement locus of the second guide member accompanying the closing operation of the opening / closing member. It has an inclined portion extending toward the opening side from the upstream side to the downstream side in the transport direction.
The opening / closing member on a projection surface when the movement locus of the second guide member and the first guide member and the metal plate at a position having the inclined portion in the width direction are viewed from the width direction. the point begins to overlap with the inclined portion and a point Q of the movement path of the second guide member due to the closing operation, as the point Q, when a line orthogonal to the inclined portion and a normal line L An image forming apparatus, wherein the inclined portion is provided so that the normal line L intersects with the support surface of the metal plate.

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