JP2002311710A - Developing gap adjusting structure, image forming device and developing gap adjusting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing gap adjusting structure capable of compara tively inexpensively and easily making the developing gap between an image carrier and a developer carrier uniform and improving the image quality. SOLUTION: A drawer 60 is arranged so that it can be freely drawn in/out to/from the housing 70 of a copying machine main body 10, and an image carrier 12 and a developing device 14 for developing a latent image on the image carrier by sticking the developer to the latent image by a developing roller (developer carrier) 22 are arranged in the drawer 60. When the drawer is drawn into the device main body, a drum shaft (image carrier supporting shaft) 76 which is supported by the device main body is fitted so as to freely rotatably support the image carrier. Besides, a spacer 82 is held between the device main body and the drawer so as to adjust the developing gap Gp between the image carrier and the developing roller.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copying machine, a printer, a facsimile, or a multifunction machine thereof.
The present invention relates to an image forming apparatus that forms a toner image on an image carrier by repeating writing, development, transfer, cleaning, and the like, and transfers the toner image to form an image on a sheet. And in such an image forming apparatus, an image carrier,
The present invention relates to a developing gap adjusting structure and a developing gap adjusting method for adjusting a developing gap between the developing device and a developer carrier.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine or a printer, for example, as shown in FIG. An image carrier, a developing device, and the like are provided in the drawer body 2 so as to be individually detachable, so that maintenance such as replacement, repair, and replenishment is performed.

In such an image forming apparatus, the developing device is provided with an agent carrier such as a developing roller for developing a latent image on the image carrier by attaching toner. When the drawer 2 is pushed into the main body 1 of the image forming apparatus, an image carrier supporting shaft supported by the main body 1 of the image forming apparatus is fitted to rotatably support the image carrier. The bodies were facing each other with a certain development gap. This development gap is extremely important in forming high image quality.

[0004]

In such an image forming apparatus, however, the axis L1 of the image carrier supporting shaft supported by the image forming apparatus main body 1 and the side of the drawer 2 on which the image carrier supporting shaft is fitted. It is very difficult to uniformly form the developing gap from the viewpoint of manufacturing accuracy due to the angular deviation of θ from the axis L2 of the member.

If the precision of parts and the precision of assembly are increased in order to make the developing gap uniform, there has been a problem that the cost is greatly increased.

SUMMARY OF THE INVENTION Accordingly, a first object of the present invention is to provide a developing gap adjusting structure which is relatively inexpensive and easily uniforms the developing gap between an image carrier and an agent carrier to improve image quality. It is in.

A second object of the present invention is to provide a developing gap adjusting structure for improving the workability of the developing gap adjusting operation for making the developing gap uniform.

A third object of the present invention is to provide a developing gap adjusting structure for improving the efficiency of developing gap adjusting work for making the developing gap uniform.

A fourth object of the present invention is to provide a developing gap adjusting structure which makes the developing gap uniform at a lower cost and improves the image quality.

A fifth object of the present invention is to provide an image forming apparatus having a developing gap adjusting structure which achieves the above object.

A sixth object of the present invention is to provide a developing gap adjusting method which makes it possible to make the developing gap between the image carrier and the agent carrier uniform at a relatively low cost and to easily improve the image quality. .

[0012]

According to a first aspect of the present invention, a drawer is provided so as to be freely inserted into and removed from an image forming apparatus main body in order to achieve the first object.
The drawer body has an image carrier, and a developing device for developing a latent image on the image carrier by attaching a developer with an agent carrier, and when the drawer body is pushed into the image forming apparatus main body,
In an image forming apparatus in which an image carrier supporting shaft supported by an image forming apparatus main body is fitted and an image carrier is rotatably supported, a spacer is interposed between the image forming apparatus main body and a drawer, and an image carrier is provided. A developing gap adjusting structure for adjusting a developing gap with the agent carrier.

According to a second aspect of the present invention, in order to achieve the second object, in the developing gap adjusting structure according to the first aspect, the drawer is fastened to the image forming apparatus main body by a fastening member at a fastening position. And a spacer is sandwiched between the image forming apparatus main body and the drawer at the fastening position.

According to a third aspect of the present invention, in order to achieve the third object, in the developing gap adjusting structure according to the first or second aspect, a spacer is attached to the image forming apparatus main body or the drawer body by bonding. It is characterized by that.

According to a fourth aspect of the present invention, in order to achieve the fourth object, in the developing gap adjusting structure according to the third aspect, a flexible adhesive sheet is used as a spacer. And

According to a fifth aspect of the present invention, there is provided an image forming apparatus for achieving the fifth object.
A developing gap adjusting structure according to 2, 3, or 4 is provided.

According to a sixth aspect of the present invention, in order to achieve the sixth object described above, a drawer is provided so as to be able to be inserted into and removed from the image forming apparatus main body, and the drawer has an image carrier and an agent carrier. A developing device for applying a developer with a body to develop a latent image on the image carrier, and when the drawer is pushed into the image forming device main body, an image carrier supporting shaft supported by the image forming device main body is provided. In an image forming apparatus which is fitted and rotatably supports an image carrier, a developing gap for adjusting a developing gap between the image carrier and the agent carrier with a spacer interposed between the image forming apparatus main body and the drawer body. It is an adjustment method.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a color copying machine shown as an example of an image forming apparatus, and shows an overall schematic configuration of an internal mechanism thereof. FIG. 2 is an enlarged view of the main part.

Reference numeral 10 in the drawing denotes a copying machine main body (image forming apparatus main body). The apparatus main body 10 has a drum-shaped image carrier 12
Is provided. Around the image carrier 12, a charging device 13 provided on the image carrier 12 rotates in the rotation direction (counterclockwise direction) indicated by an arrow in the figure.
In order, the revolver developing device 14 and the intermediate transfer unit 1
5, a cleaning device 16, a static elimination device 17, and the like are provided. A laser writing device 18 is provided on the charging device 13, the revolver developing device 14, the cleaning device 16, and the charge removing device 17.

As shown in FIG. 2, the revolver developing device 14 holds developing devices 20A, 20B, 20C, and 20D that store yellow, magenta, cyan, and black toners, respectively. Then, the developing roller (agent carrier) 22 of each of the developing units 20A, 20B, 20C, and 20D of each color can be selectively and appropriately opposed to the outer periphery of the image carrier 12 by rotating about the central axis 21. .

Next, the intermediate transfer unit 15 wraps an intermediate transfer member 24 in the form of an endless belt around a plurality of rollers 23, and a part of the intermediate transfer member 24 contacts the image carrier 12. A first transfer device 25 is provided on the inner periphery of the intermediate transfer body 24. A second transfer device 26 and a transfer member cleaning device 27 are provided on the outer periphery. The transfer member cleaning device 27 is freely movable toward and away from the intermediate transfer member 24.

The laser writing device 18 performs writing by irradiating a laser beam L in accordance with the contents read by the optical reading device 29, and forms an electrostatic latent image on the image carrier 12. The optical reading device 29 reads the content of the document G set on a contact glass 30 provided on the upper surface of the device main body 10 for each color separation light, and converts the content into an electric image signal.

Reference numeral 32 in the figure denotes a sheet conveying path for conveying a sheet such as a sheet from right to left in the figure. The intermediate transfer unit 15 and the second
A registration roller 33 is provided in front of the transfer device 26, and a transport belt 34, a fixing device 35, and a discharge roller 36 are provided later.

The apparatus main body 10 is placed on a sheet feeding device 50. In the paper feeding device 50, a plurality of paper feeding cassettes 51 are provided in multiple stages. Then, one of the sheet feeding rollers 52 is selectively driven to guide the sheet sent out from one of the sheet feeding cassettes 51 to the sheet conveying path 32 through the automatic sheet feeding path 37 in the apparatus main body 10.

A manual tray 38 is provided on the right side of the apparatus main body 10 so as to be freely opened and closed. Then, the sheet guided and inserted by the manual feed tray 38 is guided to the sheet transport path 32 through the manual feed path 39 in the apparatus main body 10. On the other hand, a discharge tray (not shown) is detachably attached to the left side of the apparatus main body 10. Then, the sheet discharged by the discharge roller 36 through the sheet conveying path 32 is received by the discharge tray.

When making a color copy using this color copier, the original G is set on the contact glass 30 and a start switch (not shown) is pressed.
Then, the optical reader 29 is operated to scan along the original surface, and the contents of the original G set on the contact glass 30 are read. At the same time, the sheet selectively fed from the sheet feeding cassette 51 of the sheet feeding device 50 by the sheet feeding roller 52 is guided to the sheet conveying path 32 through the automatic sheet feeding path 37 or the sheet set on the manual feed tray 38 is The sheet is guided to the sheet conveying path 32 through the manual sheet feeding path 39, abuts against the registration rollers 33, and is stopped.

On the other hand, the image carrier 12 is rotated in the counterclockwise direction in the figure, and the driven roller is driven to rotate by the rotation of the driving roller among the plurality of rollers 23 to convey the intermediate transfer body 24 in the clockwise direction. . Then, with the rotation of the image carrier 12, first, the surface is uniformly charged by the charging device 13, and then the laser writing device 18 irradiates the laser light L with the laser writing device 18 in accordance with the contents read by the optical reading device 29, and the first The first color electrostatic latent image is formed on the image carrier 12 by writing the color.

Thereafter, as the image carrier 12 rotates,
In the first color developing device 20A of the revolver developing device 14, toner is adhered by the developing roller 22 to visualize the electrostatic latent image to form a first color image, and the image is transferred to the first transfer device 25. Is transferred onto the intermediate transfer body 24 of the intermediate transfer unit 15. The surface of the image carrier 12 after the transfer is cleaned by the cleaning device 16 to remove the residual toner of the first color, and the charge is removed by the charge removing device 17.

Subsequently, similarly, as the image carrier 12 rotates, the image carrier 12 is uniformly charged, the second color is written, and the revolver developing device 14 is rotated to rotate the second carrier facing the image carrier 12.
The second color image formed on the image carrier 12 is developed using the color developing unit 20 </ b> B, and is transferred onto the intermediate transfer body 24 so as to overlap the first color image. Then, the image carrier 1 after the transfer
The two surfaces are cleaned and neutralized.

The images of the third and fourth colors are similarly formed on the image carrier 12 and transferred onto the intermediate transfer member 24 in a superimposed manner. Then, a composite toner image corresponding to the content of the document G is formed on the intermediate transfer body 24.

Thereafter, the registration roller 33 is rotated in synchronization with the conveyance of the intermediate transfer body 24, and the above-mentioned sheet, which has hit the registration roller 33, is fed between the intermediate transfer unit 15 and the second transfer device 26. Then, the second transfer device 26 collectively transfers the composite toner image on the intermediate transfer body 24 and performs color recording on the sheet. The sheet after the color recording is conveyed by a conveying belt 34 and put into a fixing device 35, where heat and pressure are applied between rollers to fix a transferred image. After fixing, the sheet is discharged by a discharge roller 36 and sequentially stacked on a discharge tray.

On the other hand, the surface of the intermediate transfer member 24 after the image transfer is cleaned at an appropriate timing by a transfer member cleaning device 27 pressed against the intermediate transfer member 24 to remove residual toner.

The case where the image of the original G has four colors has been described above. In the case of three colors, the three-color single-color image repeatedly formed on the image carrier 12 is transferred onto the intermediate transfer body 24 in a superimposed manner. In the case of two colors, a monochromatic image of two colors repeatedly formed on the image carrier 12 is transferred onto the intermediate transfer body 24 in a superimposed manner, and the composite toner image is collectively transferred to perform color recording on a sheet. . In the case of a single color, a single color image formed on the image carrier 12 is transferred onto the intermediate transfer body 24, and the toner image is transferred to perform single color recording on a sheet.

In the illustrated color copying machine, the above-described image carrier 12 and revolver developing device 14 are housed in a drawer 60. Then, as shown in FIG. 3, the drawer body 60 can be freely inserted into and removed from the apparatus main body 10. As shown in FIG. 4, the drawer body 60 includes a case main body 61 that houses the image carrier 12 and the revolver developing device 14, a front plate 62 attached to the front side, and a rear plate 63 attached to the back side. Is provided. A slide bearing 64 is attached to the rear plate 63.

In the revolver developing device indicated by reference numeral 14de in FIG. 4, the rotating shaft 21 is connected to the front plate 62 via bearings 65 and 66.
And the rear plate 63. Reference numeral 22 denotes a developing roller of one developing unit that faces the image carrier 12. Developing roller 2
2 is supported rotatably about the roller shaft 67.

On the other hand, in the apparatus main body 10, a drawer body storage portion 71 is formed in a housing 70, and an opening 72 is opened in the front side thereof. A shaft support 74 is attached to the rear plate 73 of the housing 70. The shaft support 74 supports a drum shaft (image carrier support shaft) 76 via a bearing 75. The drum shaft 76 is
It protrudes toward the front side so as to penetrate the drawer body storage part 71.

When the drawer body 60 is pushed into the apparatus main body 10, as shown in FIG. 4, the shaft support 74 is inserted into the slide bearing 64, and the drum shaft 76 is moved to the image carrier 12 as shown in FIG.
The front end is inserted into the bearing 68 and is supported by the front plate 62. Thereby, the image carrier 12
Is rotatably supported, and the developing roller
2, a developing gap Gp is secured.

Then, the drawer body 60 is fastened and fixed to the housing 70 of the apparatus main body 10 by the fastening member 80. At this time, according to the present invention, the developing gap Gp is measured using a dedicated measuring jig, a spacer 82 having an appropriate thickness is selected based on the measurement result, and the casing 70 of the apparatus main body 10 is fixed at the fastening position. And the front plate 62 of the drawer body 60 so that the axis of the drum shaft 76 and the axis of the image carrier 12 coincide with each other so that the developing gap Gp between the image carrier 12 and the developing roller 22 becomes uniform. adjust.

The developing gap Gp may be adjusted so that one spacer 82 of an appropriate thickness is sandwiched between the spacers 82 as shown in the illustrated example. You may make it pinch in a different position. Alternatively, spacers having the same thickness may be sandwiched in different numbers.

By doing so, it is relatively inexpensive and easy,
The development gap Gp between the image carrier 12 and the development roller 22 can be made uniform, and the image quality can be improved. Also,
When the drawer body 60 is fastened and fixed to the apparatus main body 10 by the fastening member 80, the spacer 82 can be attached at the same time, and the workability of the development gap adjustment work for making the development gap Gp uniform can be improved. .

When the spacer 82 is sandwiched, the spacer 8 is attached to the housing 70 or the drawer 60 of the apparatus body 10.
2 are attached by bonding, the spacer 82
Can be simplified, and the efficiency of the development gap adjustment operation for making the development gap Gp uniform can be improved.

In the above-described example, when the fastening member 80 is screwed to the housing 70, the spacer 82 is interposed between the drawer body 60 and the housing 70. However, as shown in FIG. 5, a spacer 82 having an appropriate thickness selected is screwed to the housing 70 with another fastening member 84, and the drawer 60 is attached to the spacer 82 integrated with the housing 70. You may use it and screw it.

The spacer 82 is not limited to a rigid one made of metal or resin, but may be a flexible adhesive sheet having an appropriate thickness. In this case, the developing gap Gp can be made more inexpensive than the rigid spacer 82 made of metal or the like, and the image quality can be improved more inexpensively.

[0044]

As described above, according to the first aspect of the present invention, the developing gap between the image carrier and the agent carrier is adjusted by simply interposing a spacer between the image forming apparatus main body and the drawer body. With this structure, the development gap between the image bearing member and the agent bearing member can be made relatively uniform at a relatively low cost, and the image quality can be improved.

According to the second aspect of the present invention, since the spacer is sandwiched between the image forming apparatus main body and the drawer at the fastening position, the drawer is fastened to the image forming apparatus main body by the fastening member and fixed. At this time, the spacer can be attached at the same time, and the workability of the developing gap adjusting operation for making the developing gap uniform can be improved.

According to the third aspect of the present invention, since the spacer is attached to the main body or the drawer of the image forming apparatus by bonding, the operation of sandwiching the spacer is simplified, and the efficiency of the developing gap adjusting operation for making the developing gap uniform is improved. Can be planned.

According to the fourth aspect of the present invention, since the flexible adhesive sheet is used as the spacer, the spacer can be manufactured at a lower cost than a rigid spacer made of metal or the like. Improvement can be achieved.

According to the invention of claim 5, claim 1,
Since the image forming apparatus includes the developing gap adjusting structure described in 2, 3, or 4, it is possible to provide an image forming apparatus including the developing gap adjusting structure having the above-described effects.

According to the sixth aspect of the present invention, since the spacer is simply interposed between the main body of the image forming apparatus and the drawer, the developing gap between the image carrier and the agent carrier is adjusted. The developing gap between the image carrier and the agent carrier can be made uniform at a relatively low cost, and the image quality can be improved.

[Brief description of the drawings]

FIG. 1 is a color copier shown as an example of an image forming apparatus, and is an overall schematic configuration diagram of an internal mechanism thereof.

FIG. 2 is an enlarged view of a main part thereof.

FIG. 3 is a perspective view showing a state where the drawer is pulled out from the apparatus main body.

FIG. 4 is a schematic plan view showing a state in which a drawer is housed in a housing of the apparatus main body.

FIG. 5 is a perspective view showing a mounting state of a spacer as another example.

FIG. 6 is a schematic plan view showing a state in which a drawer is housed in a housing of an apparatus main body for explaining a conventional problem.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Copier main body (image forming apparatus main body) 12 Image carrier 14 Revolver developing device 22 Developing roller (agent carrier) 60 Drawer 61 Case main body 62 Front plate 63 Rear plate 64 Slide bearing 65 Bearing 66 Bearing 67 Roller shaft 68 Bearing 70 Housing 71 Drawer housing section 72 Opening 73 Rear plate 74 Shaft support 75 Bearing 76 Drum shaft (image carrier support shaft) 80 Fastening member 82 Spacer Gp Development gap

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Satoshi Hatori 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Inventor Nobuo Takami 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company Ricoh F-term (reference) 2H071 BA04 BA13 BA14 BA16 BA29 CA02 DA08 DA15 2H077 BA07 BA08 BA09 BA10 GA13

Claims (6)

[Claims] 1. A drawer body is provided so as to be freely inserted into and removed from an image forming apparatus main body.
A developing device for applying a developer with a developer carrier to develop a latent image on the image carrier, wherein the image carrier is supported by the image forming apparatus main body when the drawer is pushed into the image forming apparatus main body. In an image forming apparatus in which a support shaft is fitted and the image carrier is rotatably supported, a spacer is interposed between an image forming apparatus main body and the drawer to develop the image carrier and the agent carrier. Development gap adjustment structure that adjusts the gap. 2. The image forming apparatus according to claim 1, wherein the drawer body is fastened and fixed to the image forming apparatus main body by a fastening member at a fastening position, and the spacer is sandwiched between the image forming apparatus body and the drawer body at the fastening position. Item 2. The developing gap adjusting structure according to Item 1. 3. The image forming apparatus according to claim 1, wherein the spacer is attached to the main body or the drawer body by bonding.
Or the developing gap adjusting structure according to 2. 4. The developing gap adjusting structure according to claim 3, wherein a flexible adhesive sheet is used as said spacer. 5. An image forming apparatus comprising the developing gap adjusting structure according to claim 1, 2, 3, or 4. 6. A drawer body is provided so as to be freely inserted into and removed from an image forming apparatus main body.
A developing device for applying a developer with a developer carrier to develop a latent image on the image carrier, wherein the image carrier is supported by the image forming apparatus main body when the drawer is pushed into the image forming apparatus main body. In an image forming apparatus in which a support shaft is fitted and the image carrier is rotatably supported, a spacer is interposed between an image forming apparatus main body and the drawer to develop the image carrier and the agent carrier. A developing gap adjusting method in which a gap is adjusted.