JP6988359B2 - Image forming device - Google Patents

Description

The present invention relates to an image forming apparatus that forms an image on paper.

In the image forming apparatus, a charged photoconductor is exposed based on image data to form an electrostatic latent image, and a toner is attached to the photoconductor by using a developing unit to obtain an electrostatic latent image as a toner image. Develop as. Then, this toner image is transferred to a transfer belt, and the toner image transferred to the transfer belt is transferred to a recording medium such as paper (hereinafter referred to as paper). Then, the toner image is fixed on the paper by heating and pressurizing the paper on which the toner image is transferred by the fixing roller.

The developing unit of such an image forming apparatus has a developing roller to which a developer composed of toner and a carrier is attached. Further, the developing unit is provided with a regulating mechanism for regulating the amount of the developing agent to be conveyed in order to keep the amount of the developing agent conveyed to the photoconductor by the developing roller integrally. In order to enable image formation on a wide and large paper, the length of the developing roller in the axial direction becomes long, and the developing roller is bent. Therefore, due to the bending of the developing roller, the distance between the developing roller and the regulating mechanism becomes non-uniform, and the amount of the developing agent regulated by the regulating mechanism becomes uneven.

In order to keep the distance between the developing roller and the regulating mechanism uniform, Patent Document 1 describes a technique for forming the shape of the regulating mechanism according to the amount of bending of the developing roller. Further, Patent Document 1 describes a technique for making the distance between a developing roller and a regulating mechanism uniform by elastically deforming a regulating mechanism made of an elastic material by being pressed by a developer.

Further, Patent Document 2 and Patent Document 3 describe a technique for bringing a regulatory mechanism made of an elastic body into contact with a developing roller. In the techniques described in Patent Document 2 and Patent Document 3, the regulatory mechanism is elastically deformed by the conveyed developer, so that the amount of the developer adhering to the developing roller is made uniform.

Japanese Unexamined Patent Publication No. 2008-96671 Japanese Unexamined Patent Publication No. 2-154283 Japanese Unexamined Patent Publication No. 7-20719

However, the amount of deflection of the developing roller also varies due to individual differences such as variations in length and diameter in the axial direction. Therefore, in the technique described in Patent Document 1 for forming a regulating mechanism according to the amount of bending of the developing roller, it is necessary to form the regulating mechanism in consideration of the difference in the amount of bending due to the individual difference of the developing roller. As a result, not only the productivity of the regulatory mechanism is lowered, but also it is difficult to keep the distance between the regulatory mechanism and the developing roller uniform.

Further, in the technique described in Patent Document 1, Patent Document 2 and Patent Document 3 in which the regulating mechanism is elastically deformed by the developing agent, the force applied from the developing agent to the regulating mechanism is uneven due to the difference in the amount of the developer conveyed. Was occurring. Therefore, there is a problem that the amount of elastic deformation of the regulating mechanism also becomes uneven and the amount of the developer adhering to the developing roller becomes non-uniform.

In view of the above-mentioned conventional problems, it is an object of the present invention to provide an image forming apparatus capable of easily adjusting the distance between the regulating portion of the regulating mechanism and the developing roller.

In order to solve the above problems and achieve the object of the present invention, the image forming apparatus of the present invention includes an image carrier, a developing roller, and a developing mechanism. The developing roller is arranged so as to face the image carrier, and the toner of the developer is attached to the image carrier. The regulating mechanism is arranged to face the surface of the developing roller and regulates the amount of the developer adhering to the developing roller.
The regulation mechanism includes a regulation unit, a support member, a holding member, and a plurality of adjusting screws. The regulatory section has a regulatory edge that projects toward the surface of the developing roller and regulates the amount of developer carried by the developing roller. The support member has a holding surface portion with which the regulating portion contacts. The sandwiching member sandwiches the regulating portion with the sandwiching surface portion. The plurality of adjusting screws are screwed into the plurality of holding side adjusting screw holes provided in the holding member. The plurality of holding side adjusting screw holes are formed at intervals along the axial direction of the developing roller. Then, the regulating portion is elastically deformed by being pressed toward the support member by the holding member by tightening the plurality of adjusting screws, and the amount of protrusion of the regulating end portion changes.

According to the image forming apparatus having the above configuration, the distance between the regulated end portion and the developing roller in the regulating mechanism can be easily adjusted.

It is a schematic block diagram of the image forming apparatus which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the development part of the image forming apparatus which concerns on the 1st Embodiment of this invention. It is an exploded perspective view which shows the regulation mechanism of the image forming apparatus which concerns on the example of 1st Embodiment of this invention. It is a figure which shows an example of the state which the developing roller and the regulation mechanism in the image forming apparatus which concerns on 1st Embodiment of this invention are seen from the downstream side in the transport direction of a developer. It is a figure which shows the other example of the state which the developing roller and the regulation mechanism in the image forming apparatus which concerns on 1st Embodiment of this invention are seen from the downstream side in the transport direction of a developer. It is an exploded perspective view which shows the regulation mechanism in the image forming apparatus which concerns on the 2nd Embodiment of this invention. It is a perspective view which shows the regulation mechanism in the image forming apparatus which concerns on the 2nd Embodiment of this invention. It is sectional drawing which shows the regulation mechanism in the image forming apparatus which concerns on the 2nd Embodiment of this invention. It is a perspective view which shows the regulation mechanism in the image forming apparatus which concerns on 3rd Embodiment of this invention. It is sectional drawing which shows the regulation mechanism in the image forming apparatus which concerns on 3rd Embodiment of this invention. It is an exploded perspective view which shows the conventional regulation mechanism. It is a table which shows the comparison result of the regulation mechanism which concerns on the 2nd Embodiment of this invention, and the conventional regulation mechanism.

Hereinafter, embodiments for carrying out the image forming apparatus of the present invention will be described with reference to FIGS. 1 to 12. The common members in each figure are designated by the same reference numerals. Moreover, the present invention is not limited to the following forms.

1. 1. First Embodiment 1-1. Configuration of the entire image forming apparatus First, the overall configuration of the image forming apparatus according to the first embodiment of the present invention (hereinafter referred to as “this example”) will be described. FIG. 1 is a schematic configuration diagram of the image forming apparatus 1 of this example.

The image forming apparatus 1 of this example forms an image on paper by an electrophotographic method, and superimposes four color toners of yellow (Y), magenta (M), cyan (C), and black (Bk). It is a tandem type color image forming apparatus.

As shown in FIG. 1, the image forming apparatus 1 of the present embodiment includes a document conveying section 10, a paper receiving section 20, an image reading section 30, an image forming section 40, an intermediate transfer belt 50, and a conveying section 23. And a secondary transfer unit 60, and a fixing unit 80.

The document transport section 10 includes a document paper feed tray 11 for setting a document, a plurality of rollers 12, a transport drum 13, a transport guide 14, a document ejection roller 15, and a document eject tray 16. The original G set on the original paper feed tray 11 is conveyed one by one to the reading position of the image reading unit 30 by the plurality of rollers 12 and the conveying drum 13. The transport guide 14 and the document ejection roller 15 eject the document G conveyed by the plurality of rollers 12 and the transfer drum 13 to the document ejection tray 16.

The image reading unit 30 reads the image of the document G transported by the document transport unit 10 or the document placed on the platen 31, and generates an image signal. Specifically, the image of the document G is illuminated by the lamp L. The reflected light from the document G is guided in the order of the first mirror unit 32, the second mirror unit 33, and the lens unit 34, and forms an image on the light receiving surface of the image pickup element 35. The image pickup device 35 photoelectrically converts the incident light and outputs it as a predetermined image signal. The output image signal is A / D converted, thereby creating image data.

Further, the image reading unit 30 has an image processing unit 36. The image processing unit 36 performs shading correction, dither processing, compression, and the like on the image data created by the A / D conversion, and stores the image data in the RAM of the control unit. The image data is not limited to the data output from the image reading unit 30, and may be received from an external device such as a personal computer or another image forming device connected to the image forming device 1.

A plurality of paper storage units 20 are arranged at the lower part of the main body of the apparatus, and a plurality of paper storage units 20 are provided according to the size of the paper S. This paper S is fed by the paper feeding unit 21 and sent to the transport unit 23. Further, a manual difference portion 22 is provided in the vicinity of the paper storage portion 20. From the manual part 22, special paper such as paper having a size not stored in the paper storage part 20, tag paper having a tag, and an OHP sheet is sent to the transfer position.

The transfer unit 23 is provided on the downstream side of the secondary transfer unit 60, and includes a transfer roller and a resist roller pair 71 provided in the vicinity of the secondary transfer unit 60. The resist roller pair 71 is composed of a pair of rollers including a drive roller 71a and a driven roller 71b arranged in a state of being in pressure contact with the upper side of the drive roller 71a. The nip portion formed between the drive roller 71a and the driven roller 71b serves as a transport path for the paper S.

The paper S, which is fed from the paper feed unit 21 and sent to the transfer unit 23, is conveyed to the secondary transfer unit 60, which is the transfer position, by the transfer roller and the resist roller pair 71. The resist roller pair 71 feeds the paper S to the secondary transfer unit 60 at a timing when the toner image can be transferred in the secondary transfer unit 60.

An image forming unit 40 and an intermediate transfer belt 50 are arranged between the image reading unit 30 and the paper storage unit 20. The image forming unit 40 has four image forming units 40Y, 40M, 40C, and 40K in order to form toner images of each color of yellow (Y), magenta (M), cyan (C), and black (Bk). ..

The first image forming unit 40Y forms a yellow toner image, and the second image forming unit 40M forms a magenta toner image. Further, the third image forming unit 40C forms a cyan toner image, and the fourth image forming unit 40K forms a black toner image. Since these four image forming units 40Y, 40M, 40C, and 40K each have the same configuration, the first image forming unit 40Y will be described here as a representative.

The first image forming unit 40Y includes a drum-shaped photoconductor 41, a charging unit 42 arranged around the photoconductor 41, an exposure unit 43, a developing unit 44, and a cleaning device 45. .. The photoconductor 41, which shows an example of the image carrier, is rotated counterclockwise by a drive motor (not shown). The charging unit 42 applies a charge to the photoconductor 41 and uniformly charges the surface of the photoconductor 41. The exposure unit 43 performs an exposure operation on the surface of the photoconductor 41 based on the image data read from the document G to form an electrostatic latent image on the photoconductor 41.

The developing unit 44 attaches the yellow toner to the electrostatic latent image formed on the photoconductor 41. As a result, a yellow toner image is formed on the surface of the photoconductor 41. The developing unit 44 of the second image forming unit 40M adheres magenta toner to the photoconductor 41, and the developing unit 44 of the third image forming unit 40C adheres cyan toner to the photoconductor 41. Then, the developing unit 44 of the fourth image forming unit 40K attaches the black toner to the photoconductor 41. The detailed configuration of the developing unit 44 will be described later.

The toner adhering to the photoconductor 41 is transferred to the intermediate transfer belt 50. The cleaning device 45 removes the toner remaining on the surface of the photoconductor 41 after the transfer is performed on the intermediate transfer belt 50.

The intermediate transfer belt 50 is formed in an endless shape, and is rotated clockwise by a drive motor (not shown) in a direction opposite to the rotation direction of the photoconductor 41. A primary transfer unit 51 is provided at a position of the intermediate transfer belt 50 facing the photoconductor 41 of each image forming unit 40Y, 40M, 40C, 40K. The primary transfer unit 51 applies a polarity opposite to that of the toner to the intermediate transfer belt 50 to transfer the toner image formed on the photoconductor 41 to the intermediate transfer belt 50.

Then, as the intermediate transfer belt 50 rotates, the toner images formed by the four image forming units 40Y, 40M, 40C, and 40K are sequentially transferred to the surface of the intermediate transfer belt 50. As a result, the yellow, magenta, cyan, and black toner images are overlapped on the intermediate transfer belt 50 to form a color image.

The secondary transfer unit 60 is arranged in the vicinity of the intermediate transfer belt 50 and on the downstream side of the transport unit 23. The secondary transfer unit 60 is composed of a transfer roller pair consisting of a transfer upper roller 52 on which the intermediate transfer belt 50 is stretched and a transfer lower roller 61 pressed toward the transfer upper roller 52 side with the intermediate transfer belt 50 interposed therebetween. ing.

In the secondary transfer unit 60, the paper S narrowly held and conveyed by the resist roller pair 71 in the transfer unit 23 is pressed toward the intermediate transfer belt 50 by the transfer lower roller 61. Then, the secondary transfer unit 60 transfers the color toner image formed on the intermediate transfer belt 50 onto the paper S sent from the transport unit 23. After transferring to the paper S, the cleaning unit 53 removes the toner remaining on the surface of the intermediate transfer belt 50.

The fixing unit 80 is provided on the downstream side (discharge side) of the secondary transfer unit 60 to which the paper S is conveyed, and has a pair of fixing rollers including a pair of upper fixing rollers 81 and a lower fixing roller 82. In the fixing unit 80, the toner image is fixed on the paper S by holding the paper S having the unfixed toner image by the upper fixing roller 81 and the lower fixing roller 82 and heating it under pressure.

A switching gate 24 is arranged downstream of the fixing portion 80. The switching gate 24 switches the transport path of the paper S that has passed through the fixing portion 80. That is, the switching gate 24 advances the paper S straight when performing face-up paper ejection in single-sided image formation. As a result, the paper S is discharged by the pair of paper ejection rollers 25. Further, the switching gate 24 guides the paper S downward when performing face-down paper ejection in which the image forming surface in single-sided image formation is directed downward and double-sided image formation.

When performing face-down paper ejection, the paper S is guided downward by the switching gate 24, and then the front and back sides are reversed by the paper reversing transport unit 26 to transport the paper S upward. As a result, the paper S is discharged by the pair of paper ejection rollers 25. When forming a double-sided image, the paper S is guided downward by the switching gate 24, the front and back sides are reversed by the paper reversing transport unit 26, and the paper is sent to the transfer position again by the refeeding path 27.

Further, a post-processing device for folding the paper S or performing stable processing on the paper S may be arranged on the downstream side of the pair of paper ejection rollers 25.

1-2. Configuration Example of Development Unit Next, the configuration of the development unit in the image forming apparatus 1 of this example will be described with reference to FIGS. 2 to 5.
FIG. 2 is a cross-sectional view showing a developed portion of this example.

[Development unit]
As shown in FIG. 2, the developing unit 44 includes a developing roller 141, two stirring screws 142a and 142b, a case 145, and a regulating mechanism 150. The case 145 is formed in the shape of a hollow container and rotatably accommodates the developing roller 141 and the stirring screws 142a and 142b. Further, a regulation mechanism 150 is installed in the case 145.

The axial direction of the developing roller 141 is arranged parallel to the axial direction of the photoconductor 41. Further, the developing roller 141 is rotatably supported by the case 145. Then, a part of the developing roller 141 is exposed from the opening 145b of the case 145, and the developing roller 141 is arranged close to the surface of the photoconductor 41. Further, the developing roller 141 is inscribed with a plurality of magnetic poles that generate a magnetic field.

The stirring screws 142a and 142b are screw members formed in a spiral shape. The stirring screws 142a and 142b are rotatably supported by the case 145. Then, the first stirring screw 142a is triboelectrically charged by mixing and stirring the toner supplied in the case 145 with the carrier. Due to triboelectric charging, toner is adsorbed on the carrier. As a result, the developer T1 composed of the toner and the carrier is formed. Then, the developer T1 formed by the second stirring screw 142b is supplied to the surface of the developing roller 141, and adheres to the surface of the developing roller 141 by the magnetic attraction of the developing roller 141.

The regulatory mechanism 150 is installed in the case 145. In the regulation mechanism 150, the regulation end portion 152a of the regulation unit 152, which will be described later, is arranged with a uniform interval Db with respect to the surface 141a of the developing roller 141. The regulating mechanism 150 removes the excess developer T1 adhering to the developing roller 141, and regulates the amount of the developer T1 transported to the photoconductor 41 by the developing roller 141.

FIG. 3 is an exploded perspective view showing the regulation mechanism 150.
As shown in FIG. 3, the regulation mechanism 150 includes a support member 151, a regulation portion 152, a sandwiching member 153, and a plurality of adjusting screws 154.

The support member 151 is formed by bending a part of a substantially flat plate-shaped member substantially vertically. The support member 151 has a mounting surface portion 156 and a holding surface portion 157. The mounting surface portion 156 is formed in a substantially rectangular flat plate shape. A holding surface portion 157 is continuously formed substantially vertically at one end portion of the mounting surface portion 156 in the lateral direction. As shown in FIG. 2, the mounting surface portion 156 is mounted in the case 145 so that the holding surface portion 157 projects toward the surface 141a of the developing roller 141.

As shown in FIG. 3, the holding surface portion 157 is formed in a substantially rectangular flat plate shape. The longitudinal direction of the sandwiching surface portion 157 is arranged substantially parallel to the axial direction of the developing roller 141. A plurality of support-side adjusting screw holes 171 are formed in the holding surface portion 157 at intervals along the longitudinal direction. The support-side adjusting screw hole 171 penetrates from the support-side holding surface 157a in contact with the regulating portion 152 described later in the holding-side surface portion 157 to the opposite surface. A female screw is formed in the support side adjusting screw hole 171.

The regulating portion 152 is formed of an elastic member. Further, the restricting portion 152 is formed in a long shape extending in the longitudinal direction of the holding surface portion 157, that is, along the axial direction of the developing roller 141. Further, the restricting portion 152 is arranged in contact with the supporting side holding surface 157a of the holding surface portion 157 of the support member 151. A plurality of insertion holes 172 are formed in the regulating portion 152 at intervals along the longitudinal direction.

The plurality of insertion holes 172 face the plurality of support-side adjusting screw holes 171 formed in the sandwiching surface portion 157 when the regulating portion 152 is brought into contact with the support-side holding surface 157a of the sandwiching surface portion 157. Further, the opening diameter of the insertion hole 172 is formed to be larger than the outer diameter of the threaded portion of the adjusting screw 154.

The pinching member 153 comes into contact with one surface of the regulating portion 152 on the side opposite to the pinching surface portion 157. The sandwiching member 153 is formed of a rectangular flat plate-shaped member. The sandwiching member 153 is arranged so that its longitudinal direction is substantially parallel to the longitudinal direction of the sandwiching surface portion 157 of the support member 151 and the restricting portion 152, that is, the axial direction of the developing roller 141.

The sandwiching member 153 is formed with a plurality of sandwiching side adjusting screw holes 173 at intervals along the longitudinal direction. The pinching-side adjusting screw hole 173 penetrates from the pinching-side pinching surface 153a in contact with the restricting portion 152 of the pinching member 153 to the opposite surface. A female screw is formed in the pinching side adjusting screw hole 173.

The plurality of pinching side adjusting screw holes 173 face a plurality of insertion holes 172 provided in the regulating portion 152 when the pinching member 153 is brought into contact with the regulating portion 152. That is, the pinching side adjusting screw hole 173 faces the supporting side adjusting screw hole 171 of the support member 151 via the insertion hole 172. An adjusting screw 154 is screwed into the holding side adjusting screw hole 173 and the supporting side adjusting screw hole 171. At this time, the adjusting screw 154 inserts the insertion hole 172 of the regulating portion 152. As a result, the regulating portion 152 is sandwiched and fixed by the sandwiching surface portion 157 of the support member 151 and the sandwiching member 153. Further, since the adjusting screw 154 inserts the insertion hole 172, the regulating portion 152 does not come off from the support member 151 or the holding member 153.

Further, by tightening the adjusting screw 154 to the holding side adjusting screw hole 173 and the supporting side adjusting screw hole 171, the regulating portion 152 is pressed against the holding surface portion 157 side of the supporting member 151 by the holding member 153. Therefore, as shown in FIG. 2, the regulating portion 152 is elastically deformed, and the restricting end portion 152a in the lateral direction of the regulating portion 152 protrudes toward the surface 141a of the developing roller 141. The restricted end portion 152a faces the surface 141a of the developing roller 141 with a predetermined interval Db.

Further, the developer T1 passes through the gap between the regulated end portion 152a and the surface 141a of the developing roller 141, so that the excess developing agent T1 is removed from the developing roller 141. By regulating the amount of the developer T1 transported to the photoconductor T1 in this way, the amount of the developer T1 transported to the photoconductor 41 by the developing roller 141 can be maintained integrally.

The materials of the support member 151 and the sandwiching member 153 are relatively rigid, such as aluminum alloy, stainless steel, steel and other metals, ABS (acrylonitrile, butadiene, styrene resin), POM (polyacetal) and other plastics. It is preferable to use a high one.

Further, as the material of the regulating portion 152, for example, a rubber material such as urethane rubber or other various elastic members are applied. Further, the regulating portion 152 may be configured by filling a bag-shaped member made of a rubber material with powder, liquid, gas or the like. The hardness of the regulating unit 152 is set to a hardness that does not deform due to the force applied from the developer T1 conveyed by the developing roller 141.

1-3. Adjustment work of the regulation mechanism Next, the adjustment work of the distance Db between the regulation end portion 152a and the surface 141a of the developing roller 141 in the regulation mechanism 150 having the above-described configuration will be described with reference to FIGS. 4 and 5.
FIG. 4 is a diagram showing an example of a state in which the developing roller 141 and the regulating mechanism 150 are viewed from the downstream side in the transport direction of the developer.

As shown in FIG. 4, when the length of the developing roller 141 in the axial direction becomes long, the central portion in the axial direction bends due to its own weight rather than the state without bending shown by the alternate long and short dash line. Therefore, the distance Db between the surface 141a of the developing roller 141 and the regulation end portion 152a of the regulation mechanism 150 becomes non-uniform.

Therefore, in the example shown in FIG. 4, the tightening amount of the adjusting screw 154B arranged at the central portion in the longitudinal direction of the sandwiching member 153 is larger than the tightening amount of the adjusting screw 154A arranged at the end portion in the longitudinal direction of the sandwiching member 153. Also many. As a result, the central portion in the longitudinal direction of the restricting portion 152 is pressed more strongly toward the support member 151 by the sandwiching member 153 than the end portion in the longitudinal direction of the restricting portion 152. Therefore, the central portion in the longitudinal direction of the restricting portion 152 is elastically deformed more than the end portion in the longitudinal direction, and the protrusion amount of the regulated end portion 152a in the central portion in the longitudinal direction of the restricting portion 152 is larger than the end portion in the longitudinal direction. Will also grow. As a result, the distance Db between the surface 141a of the developing roller 141 and the regulation end portion 152a of the regulation mechanism 150 can be uniformly adjusted.

As described above, the longitudinal direction of the holding member 153 and the restricting portion 152 is arranged substantially parallel to the axial direction of the developing roller 141.

As described above, according to the regulation mechanism 150 of this example, by adjusting the tightening amount of the plurality of adjusting screws 154 arranged along the axial direction of the developing roller 141, the surface of the developing roller 141 at the restricted end portion 152a is formed. The amount of protrusion to 141a can be adjusted. As a result, it is possible to prevent the density unevenness of the formed image caused by the non-uniformity Db between the surface 141a of the developing roller 141 and the regulation end portion 152a of the regulation mechanism 150.

Further, a plurality of adjusting screws 154 are provided at intervals parallel to the axial direction of the developing roller 141. Therefore, by adjusting the tightening amount of the plurality of adjusting screws 154 according to the difference in the amount of bending due to the individual difference of the developing roller 141, the distance between the surface 141a of the developing roller 141 and the regulation end portion 152a of the regulation mechanism 150 Db can be easily adjusted.

Further, as described above, the hardness of the regulating portion 152 is set to a hardness that does not deform due to the force applied from the developer T1 conveyed by the developing roller 141. Therefore, it is possible to prevent the distance Db between the surface 141a of the adjusted developing roller 141 and the regulating end portion 152a of the regulating mechanism 150 from changing due to the force applied from the conveyed developer T1. As a result, even if the force applied from the conveyed developer T1 becomes uneven, the distance Db between the surface 141a of the developing roller 141 and the regulated end portion 152a of the regulating mechanism 150 does not change.

FIG. 5 shows another example of a state in which the developing roller 141 and the regulating mechanism 150 are viewed from the downstream side in the transport direction of the developer.
As shown in FIG. 5, the end surface of the surface 141a of the developing roller 141 in the holding surface portion 157 (see FIGS. 2 and 3) of the holding member 153 of the regulating mechanism 150 and the supporting member 151 is parallel to the axial direction of the developing roller 141. It is difficult to make it uniformly. However, according to the regulation mechanism 150 of this example, by adjusting the tightening amount of the plurality of adjusting screws 154, the developing roller 141 at the regulation end portion 152a is not affected by the distortion of the sandwiching member 153 and the sandwiching surface portion 157. The amount of protrusion of the surface 141a can be adjusted. As a result, the distance Db between the surface 141a of the developing roller 141 and the regulation end portion 152a of the regulation mechanism 150 can be easily adjusted. Further, the processing accuracy required for the support member 151 and the sandwiching member 153 can be lowered, and the manufacturing work of the regulation mechanism 150 can be easily performed.

The above-mentioned adjustment work may be performed not only at the time of manufacturing the image forming apparatus 1 but also at the time of maintenance of the image forming apparatus 1.

2. 2. Second Embodiment Example Next, the image forming apparatus according to the second embodiment will be described with reference to FIGS. 6 to 8.
6 is an exploded perspective view showing the regulation mechanism according to the second embodiment, FIG. 7 is a perspective view, and FIG. 8 is a sectional view.

The difference between the image forming apparatus according to the second embodiment and the image forming apparatus 1 according to the first embodiment is the configuration of the regulatory mechanism. Therefore, here, the regulation mechanism will be described, and the same reference numerals will be given to the parts common to the image forming apparatus 1 according to the first embodiment, and duplicate description will be omitted.

As shown in FIGS. 6 to 8, the regulation mechanism 250 includes a support member 251, a regulation portion 252, a sandwiching member 253, and a plurality of adjusting screws 154. The support member 251 has a mounting surface portion 256 and a holding surface portion 257. A support-side fixing screw hole 256a is formed in the mounting surface portion 256. A female screw is formed in the support-side fixing screw hole 256a. The restricting portion 252 comes into contact with the supporting side holding surface 257a of the holding surface portion 257. Note that the holding surface portion 257 is not provided with the support side adjusting screw hole 171 unlike the holding surface portion 157 according to the first embodiment.

The regulation unit 252 is formed in the same shape as the regulation unit 252 according to the first embodiment. Note that the regulation unit 252 is not provided with the insertion hole 172 unlike the regulation unit 152 according to the first embodiment. Further, the adhesive N1 is applied to the end portion of the regulation portion 252 opposite to the regulation end portion 252a. Then, the regulating portion 252 is sandwiched by the support member 251 and the sandwiching member 253 described later, and is adhesively fixed to the sandwiching member 253 via the adhesive N1. As a result, it is possible to prevent the regulating portion 252 from falling out of the holding member 253 even if the regulating portion 252 is not provided with an insertion hole 172 through which the adjusting screw 154 is inserted.

The sandwiching member 253 has a holding plate 261 and a sandwiching plate 262. The holding plate 261 is formed by bending a part of a substantially flat plate-shaped member substantially vertically, similarly to the support member 251. The holding plate 261 has a mounting piece 264 and a holding piece 265.

The mounting piece 264 is formed in a substantially rectangular shape. The mounting piece 264 is placed on the mounting surface portion 256 of the support member 251. Further, a pinching side fixing screw hole 264a is formed at a position of the mounting piece 264 facing the support side fixing screw hole 256a of the mounting surface portion 256. Then, the holding side fixing screw hole 264a communicates with the supporting side fixing screw hole 256a. Further, a female screw is formed in the holding side fixing screw hole 264a. As shown in FIG. 8, the fixing screw 280 is screwed into the holding side fixing screw hole 264a and the supporting side fixing screw hole 256a. As a result, the mounting piece 264 is fastened and fixed to the mounting surface portion 256 of the support member 251 via the fixing screw 280.

A holding piece 265 is substantially vertically continuous at one end of the mounting piece 264 in the lateral direction. The holding piece 265 projects in the same direction as the holding surface portion 257 of the support member 251. When the mounting piece 264 is fixed to the mounting surface portion 256 of the support member 251, the holding piece 265 is arranged so as to face the holding surface portion 257 with the restricting portion 252 and the holding plate 262 described later sandwiched between them.

The holding piece 265 is formed in a substantially rectangular flat plate shape. The longitudinal direction of the holding piece 265 is arranged substantially parallel to the longitudinal direction of the holding surface portion 257, that is, arranged substantially parallel to the axial direction of the developing roller 141. The holding piece 265 is formed with a plurality of holding side adjusting screw holes 273 at intervals along the longitudinal direction. The holding side adjusting screw hole 273 penetrates the holding piece 265 from one surface facing the holding surface portion 257 to the other surface on the opposite side. A female screw is formed in the pinching side adjusting screw hole 273. An adjusting screw 154 is screwed into the holding side adjusting screw hole 273.

A holding plate 262 is arranged between the holding piece 265 and the regulating portion 252. The holding plate 262 is formed in a flat plate shape having a substantially rectangular shape. The holding plate 262 is arranged so that its longitudinal direction is substantially parallel to the longitudinal direction of the holding piece 265 and the holding surface portion 257. The holding plate 262 is formed with a plurality of adjusting screw recesses 274 at intervals along the longitudinal direction.

The adjusting screw recess 274 is formed on the surface of the holding plate 262 opposite to the holding side holding surface 262a to which the regulating portion 252 contacts. The plurality of adjusting screw recesses 274 face the holding side adjusting screw holes 273 provided in the holding piece 265 when the holding plate 262 is arranged between the holding piece 265 and the regulating portion 252. Then, the end of the adjusting screw 154, which is screwed into the holding side adjusting screw hole 273 and penetrates the holding piece 265, comes into contact with the adjusting screw recess 274.

By forming the adjusting screw recess 274 in the holding plate 262, it is possible to prevent the end portion of the adjusting screw 154 from slipping on the surface of the holding plate 262.

As a result, the restricting portion 252 is sandwiched between the sandwiching plate 262 and the sandwiching surface portion 257. Further, by further tightening the plurality of adjusting screws 154, the regulating portion 252 is pressed against the holding surface portion 257 side by the holding plate 262. Therefore, the regulation portion 252 is elastically deformed, and the regulation end portion 252a on the side opposite to the holding piece 265 in the regulation portion 252 projects toward the developing roller 141 (see FIG. 2).

Further, the end portion of the regulating portion 252 opposite to the regulating end portion 252a faces the mounting piece 264 of the sandwiching member 253 and is adhesively fixed via the adhesive N1. Therefore, even if the holding plate 262 is pressed against the holding surface portion 257, the elastic deformation of the end portion of the regulating portion 252 opposite to the regulating end portion 252a is limited by the mounting piece 264 of the holding member 253. As a result, the regulated end portion 252a in the regulated portion 252 can be easily elastically deformed.

Further, by adjusting the tightening amount of the plurality of adjusting screws 154, the force with which the holding plate 262 presses the regulating portion 252 toward the holding surface portion 257 changes. As a result, the amount of protrusion of the regulated end portion 252a in the longitudinal direction of the restricting portion 252, that is, in the axial direction of the developing roller 141 can be adjusted, and the distance between the developing roller 141 and the regulated end portion 252a can be easily adjusted. can.

Since other configurations are the same as those of the regulatory mechanism 150 according to the first embodiment described above, the description thereof will be omitted. Even with such a regulatory mechanism 250, the same operations and effects as those of the regulatory mechanism 150 according to the first embodiment described above can be obtained.

Further, according to the regulation mechanism 250 according to the second embodiment, since the insertion hole 172 is not provided in the regulation portion 252, it is possible to prevent the durability of the regulation portion 252 from being lowered by the insertion hole 172. Can be done. Further, it is possible to prevent the elastic deformation of the regulation portion 252 from being changed by the insertion hole 172, and the work of adjusting the protrusion amount of the regulation end portion 252a in the regulation portion 252 is performed from the regulation mechanism 150 according to the first embodiment. Can also be easily done.

Further, in the regulation mechanism 250 according to the second embodiment, an example in which the sandwich plate 262 for sandwiching the regulation portion 252 is composed of one member has been described, but the present invention is not limited thereto. For example, the holding plate 262 may be divided into a plurality of parts along the axial direction of the developing roller 141.

3. 3. Example of Third Embodiment Next, the image forming apparatus according to the third embodiment will be described with reference to FIGS. 9 and 10.
9 is a perspective view showing the regulation mechanism according to the third embodiment, and FIG. 10 is a cross-sectional view.

The image forming apparatus according to the third embodiment is a modification of the configuration of the regulation unit 252 of the regulation mechanism 250 according to the second embodiment. Therefore, here, the regulatory mechanism will be described, and the parts common to the regulatory mechanism 150 according to the first embodiment and the regulatory mechanism 250 according to the second embodiment are designated by the same reference numerals and overlapped. The explanation given is omitted.

As shown in FIGS. 9 and 10, the regulation mechanism 350 has a support member 251, a regulation portion 352, a sandwiching member 353, and a plurality of adjusting screws 154. Since the configuration of the support member 251 is the same as the configuration of the support member 251 according to the second embodiment, the description thereof will be omitted.

The sandwiching member 353 has a holding plate 361 and a sandwiching plate 262. Since the holding plate 262 has the same configuration as the holding plate 262 according to the second embodiment, the description thereof will be omitted. The holding plate 361 is formed by bending a part of a substantially flat plate-shaped member substantially vertically, similarly to the support member 251. The holding plate 361 has a mounting piece 364 and a holding piece 365. The holding piece 365 is continuously provided substantially vertically from one end of the mounting piece 364 in the lateral direction.

The mounting piece 364 is formed in a substantially rectangular shape. Further, the mounting piece 364 is formed with a holding-side fixing screw hole 364a and a plurality of injection ports 364b. A fixing screw 280 is screwed into the holding side fixing screw hole 364a. Then, the mounting piece 364 is fastened and fixed to the mounting surface portion 256 of the support member 251 via the fixing screw 280.

The plurality of injection ports 364b are formed at one end of the mounting piece 364 in the lateral direction. The plurality of injection ports 364b are formed at intervals along the longitudinal direction of the mounting piece 364, that is, the axial direction of the developing roller 141. Further, the plurality of injection ports 364b penetrate from the surface of the mounting piece 364 facing the mounting surface portion 256 to the surface opposite to the mounting surface portion 256. As shown in FIG. 10, the injection port 364b communicates with the space formed between the holding plate 262 and the holding surface portion 257 of the support member 251. A funnel K1 is detachably attached to the injection port 364b.

Further, the plurality of injection ports 364b are provided so as to avoid the position where the adhesive N1 for adhering and fixing the regulating portion 352 and the mounting piece 364 is applied.

The regulation portion 352 is made of a material that is cured by external factors such as seam, drying, heating, and ultraviolet rays, and is made of a material that can maintain the protrusion amount of the regulation end portion 352a before curing. The regulation unit 352 is made of, for example, a hydrophilic vinyl silicone material. Then, the regulating portion 352 is injected from the injection port 364b by the funnel K1 between the holding side holding surface 262a of the holding plate 262 and the supporting side holding surface 257a of the holding surface portion 257 of the support member 251. Then, when the injection work of the regulation unit 352 is completed, the funnel K1 is removed from the injection port 364b of the mounting piece 364.

The protrusion amount of the regulated end portion 352a in the regulated portion 352 may be adjusted before the regulated portion 352 is completely cured, or may be performed after the regulated portion 352 is cured. Further, the surface of the regulated end portion 352a may be prepared with a spatula or the like before the regulated portion 352 is completely cured.

Since other configurations are the same as those of the regulatory mechanism 150 according to the first embodiment and the regulatory mechanism 250 according to the second embodiment described above, their description will be omitted. With such a regulatory mechanism 350, the same functions and effects as those of the regulatory mechanism 150 according to the first embodiment and the regulatory mechanism 250 according to the second embodiment can be obtained.

4. Comparison of Conventional Examples Next, a comparative example of concentration unevenness between the regulatory mechanism according to the embodiment of the present invention and the conventional regulatory mechanism will be described with reference to FIGS. 11 and 12. As an example of the embodiment of the present invention, the regulatory mechanism 250 according to the above-mentioned second embodiment is used.
FIG. 11 is a perspective view showing a conventional regulatory mechanism, and FIG. 12 is a comparison between the regulatory mechanism according to the second embodiment (hereinafter, simply referred to as “the present embodiment”) and the conventional regulatory mechanism. It is a table showing the result.

As the developing roller 141, those having a length in the axial direction of 555 mm and a length of a region to which the developer T1 adheres are 530 mm are used in both the examples and the conventional examples. The length of the width in which the image can be formed by the developing roller 141, that is, the length in the axial direction of the developing roller 141 is set to 515 mm.

Further, the support member 251 and the sandwiching member 253 of the regulation mechanism 250 of this embodiment are formed of a non-magnetic metallic member. The length of the holding surface portion 257 of the support member 251 and the holding plate 262 of the holding member 253 and the holding piece 265 of the holding plate 261 in the longitudinal direction is set to 535 mm. Further, the regulating portion 252 is made of urethane rubber. The length of the regulating portion 252 in the longitudinal direction in the state of not being elastically deformed is set to 535 mm.

As shown in FIG. 11, the conventional regulation mechanism 500 has a support member 551 and a regulation plate 552. The support member 551 is formed by bending a part of a substantially flat plate-shaped member substantially vertically, similarly to the support member 251 according to the second embodiment. The support member 551 has a mounting surface portion 556 and a support surface portion 557 that are mounted inside the case of the developing unit.

The support surface portion 557 is formed substantially vertically and continuously from the end portion of the mounting surface portion 556 toward the developing roller 141 (see FIG. 2). A plurality of support screw holes 571 are formed in the support surface portion 557 at intervals along the axial direction of the developing roller 141. A substantially flat plate-shaped regulation plate 552 is fastened and fixed to the support surface portion 557 via an adjusting screw 554.

A plurality of insertion holes 572 are formed in the regulation plate 552 at intervals along the axial direction of the developing roller 141. The insertion hole 57 2 is a long hole formed so that the length in the lateral direction is longer than that in the longitudinal direction of the regulation plate 552. Then, the insertion hole 572 faces the support screw hole 571, and the adjustment screw 554 is inserted through the insertion hole 572.

In the conventional regulation mechanism 500, the regulation plate 552 is moved along the insertion hole 572 to adjust the distance between the end portion of the regulation plate 552 on the development roller 141 side and the development roller 141. Then, in the conventional regulation mechanism 500, the excess developer T1 adhering to the surface 141a of the developing roller 141 is removed from the developing roller 141 by the regulating plate 552.

Further, in the conventional regulation mechanism 500, the regulation plate 552 is the same as the support member 551, such as aluminum alloy, stainless steel, steel and other metals, ABS (acrylonitrile, butadiene, styrene resin), POM (polyacetal) and others. It is made of a relatively rigid material such as plastic.

In both the regulation mechanism 250 and the conventional regulation mechanism 500 of this embodiment, the distance Db (see FIG. 2) from the developing roller 141 is adjusted to 0.71 mm. In the conventional regulation mechanism 500, in order to adjust the spacing Db by moving the regulation plate 552 made of a highly rigid material along the insertion hole 572, both ends and the center portion of the regulation plate 552 in the longitudinal direction are used. , It is difficult to make the interval Db uniform. Therefore, in the conventional regulation mechanism 500, an error of 0 ± 0.10 mm occurs with respect to the target interval Db. On the other hand, in the regulation mechanism 250 of the present embodiment, the amount of elastic deformation of the regulation portion 252 can be adjusted by changing the tightening amount of the plurality of adjusting screws 154. Therefore, in the regulation mechanism 250 of this embodiment, the range of error from the target interval Db can be reduced to 0.03 mm.

Then, when the developer T1 having a toner concentration Tc (%) of 8%, 6%, and 4% is used by using the regulation mechanism 250 and the conventional regulation mechanism 500 of the present embodiment having the above-described configuration, respectively. The degree of density unevenness visually recognized on the formed image is evaluated. The toner concentration Tc is calculated by Tc = (toner weight) / {(toner weight) + (carrier weight)} × 100. Further, the image formed on the paper forms a black monochromatic image having a printing rate of 50%.

As shown in FIG. 12, according to the regulation mechanism 250 of this embodiment, it can be seen that the degree of density unevenness is good when the toner concentration Tc is 8% or 6%. Further, even when the toner concentration Tc is 4%, the degree of density unevenness is not good, but it is within an acceptable range.

On the other hand, in the conventional regulation mechanism 500, when the toner concentration Tc is 8% or 6%, the degree of density unevenness is not good, but it is within an acceptable range. As described above, in the conventional regulation mechanism 500, when the toner concentration Tc is 8% or 6%, the degree of density unevenness is within an acceptable range, but the degree of density unevenness is higher than that of the regulation mechanism 250 of this embodiment. It turns out to be inferior. Further, in the conventional regulation mechanism 500, when the toner density Tc is low and 4%, the density unevenness becomes conspicuous, and the image is unacceptable.

As described above, according to the regulation mechanism 250 of the present embodiment, the distance Db between the developing roller 141 and the regulation end portion 252a can be finely adjusted as compared with the conventional regulation mechanism 500, so that the processing is carried by the developing roller 141. It is possible to suppress the occurrence of unevenness in the amount of the developer T1 conveyed, and it is possible to suppress the occurrence of density unevenness generated on the image. Further, in the conventional regulation mechanism 500, since the degree of unevenness in the transport amount of the developer T1 adhering to the developing roller 141 is large, when the toner concentration Tc becomes small as in the case where the toner concentration Tc is 4%, the developing region It is easy for some parts to be unable to supply a sufficient amount of toner, and uneven density is likely to occur. On the other hand, even when the toner concentration Tc is small, the regulation mechanism 250 of this embodiment can reduce the unevenness of the transport amount of the developer T1 adhering to the developing roller 141, so that the occurrence of the density unevenness is suppressed. be able to.

As described above, according to the regulation mechanism 250 of the present embodiment, the distance Db between the developing roller 141 and the regulation end portion 252a can be easily and precisely adjusted, so that the toner concentration Tc of the developer T1 to be conveyed can be easily and precisely adjusted. It is possible to form an image without uneven density without being affected by.

In the above, the embodiment of the image forming apparatus has been described including its action and effect. However, the image forming apparatus of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the invention described in the claims.

In the above-described embodiment, four sets of image forming units 40Y, 40M, 40C, and 40K are used to form a color image, but the image forming apparatus according to the present invention has one image forming unit. It may be configured to form a monochromatic image by using it. Further, the image forming apparatus is not limited to a copying machine, but may be a printer, a facsimile, or a multifunction device having a plurality of functions.

Although words such as "parallel" and "orthogonal" are used in the present specification, these do not mean only strict "parallel" and "orthogonal", but include "parallel" and "orthogonal". Further, it may be in a "substantially parallel" or "substantially orthogonal" state within a range in which the function can be exhibited.

1 ... Image forming device, 10 ... Original transfer unit, 11 ... Original paper feed tray, 20 ... Paper storage unit, 23 ... Transfer unit, 30 ... Image reading unit, 36 ... Image processing unit, 40 ... Image forming unit, 41 ... Photoreceptor (image carrier), 42 ... charged part, 43 ... exposed part, 44 ... developing part, 50 ... intermediate transfer belt, 51 ... primary transfer part, 60 ... secondary transfer part, 80 ... fixing part, 141 ... Developing roller, 141a ... Surface, 142a, 142b ... Stirring screw, 145 ... Case, 145b ... Opening, 150, 250, 350 ... Regulatory mechanism, 151, 251 ... Support member, 152, 252, 352 ... Regulatory part, 152a, 252a, 352a ... Restricted end, 153, 253, 353 ... Holding member, 153a, 262a ... Holding side holding surface, 154, 154A, 154B ... Adjusting screw, 156, 256 ... Mounting surface, 157, 257 ... Holding surface, 157a , 257a ... Support side holding surface, 171 ... Support side adjusting screw hole, 172 ... Insertion hole, 173, 273 ... Holding side adjusting screw hole, 261, 361 ... Holding plate, 262 ... Holding plate, 264, 364 ... Mounting piece, 265, 365 ... Retaining piece, 274 ... Adjusting screw recess, 350 ... Regulatory mechanism, 364b ... Injection port, K1 ... Leakage, N1 ... Adhesive, T1 ... Developer, Db ... Spacing, S ... Paper

Claims (4)

Image carrier and
A developing roller, which is arranged so as to face the image carrier and adheres the toner of the developer to the image carrier,
It is provided with a regulating mechanism that is arranged facing the surface of the developing roller and regulates the amount of the developing agent adhering to the developing roller.
The regulatory mechanism is
A regulating portion for the protruding toward the surface of the developing roller, and have a regulating end portion for regulating the amount of the developer conveyed by the developing roller, is formed of a material having elasticity,
A support member having a holding surface portion with which the restricting portion contacts, and a support member
A sandwiching member that sandwiches the restricting portion with the sandwiching surface portion, and
A plurality of adjusting screws screwed into the plurality of holding side adjusting screw holes provided in the holding member are provided.
The plurality of holding side adjusting screw holes are formed at intervals along the axial direction of the developing roller.
By adjusting the tightening amount of the plurality of adjusting screws, the restricting portion is pressed toward the support member by the holding member and elastically deformed, so that the protruding amount of the regulated end portion is adjusted.
A plurality of insertion holes through which the plurality of adjusting screws are inserted are formed in the restricting portion.
An image forming apparatus in which a plurality of support-side adjusting screw holes into which a plurality of the adjusting screws are screwed are formed in the support member. The image forming apparatus according to claim 1, wherein the regulating unit is set to a hardness that is not deformed by a force applied from a developer conveyed by the developing roller. The image forming apparatus according to claim 1, wherein the regulating portion is formed of a material that is cured by an external factor. The image forming apparatus according to claim 1 or 3 , wherein an injection hole into which the regulation portion can be injected is formed in the support member.

Images