JPH11174765A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the interference of a unit to be pressed with a photoreceptive unit because the photoreceptive unit is made movable by operating a fixed means at time other than required in the case of freely attachably detachably attaching a photoreceptive unit having a photoreceptive drum to/from a device main body and fixing it by a fixing means and pressing the unit to be pressed such as a developing unit to the photoreceptive unit by a pressing means. SOLUTION: As for an image forming device having the photoreceptive drum where an electrostatic latent image is formed by arranging an electric charge on a surface and freely attachably/detachably arranging the photoreceptive unit at the device main body, and fixing the photoreceptive unit at the device main body by a machine screw 1 or the like and pressing a developing unit as the unit to be pressed to the side of the photoreceptive unit attached by a cam or the like, a shutter member 14 capable of freely opening and closing is provided at the developing unit, and fixing by the machine screw 1 is released by separating the shutter member 14 from the pull-out locus of the machine screw 1 only at the time of releasing a pressing state, so that the interference between the photoreceptive unit and the developing unit is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as an electrophotographic copying machine and a printer, and more particularly, to a method for preventing a photoconductor unit from being fixedly operated so that the photoconductor unit cannot be removed from a main body of the apparatus. hand,
The present invention relates to an image forming apparatus that does not damage a photosensitive drum or the like.

[0002]

2. Description of the Related Art An example of a conventional image forming apparatus will be described with reference to FIG. In the figure, the surface of a photosensitive drum 9 as an image carrier is uniformly charged by a primary charger 12 and is exposed by a laser from a laser unit 30 to form an electrostatic latent image on the surface. Next, the toner as a developer stored in the developing device 7 is conveyed to a photosensitive drum by a developing sleeve 8 which is a developer carrying member to perform development, and a latent image is visualized to form a developed image. The developed image is transferred to a transfer material fed by a paper feeding device (not shown) by a transfer unit 31, and the transfer material is conveyed to a fixing unit 32, where the developed image is heated and fixed to the transfer material. The residual toner remaining on the photosensitive drum without being transferred is removed by cleaning means 11 such as a blade.

Next, a developing device of a conventional image forming apparatus will be described with reference to FIG.

FIG. 4A is a schematic view of the periphery of the developing device in a pressed state. In this figure, reference numeral 2 denotes a photosensitive member unit having a photosensitive drum 9 on which an electrostatic latent image is formed by arranging an electric charge on a surface by an exposure unit in an electrophotographic system, and at least one of a cleaning blade 11 and a charger 12. Are unitized. Reference numeral 1 denotes fixing means for fixing the photoconductor unit 2 to the main body of the image forming apparatus. In the illustrated example, a screw is used which is closed to the back side of the drawing. Reference numeral 2A denotes a housing of the photoconductor unit 2, in which a photoconductor drum 9, a charger 12 and the like are housed. The housing of the photoreceptor unit 2 has a flange portion 2B extending in parallel with the rotation axis of the photoreceptor drum 9. By sliding the flange portion 2B onto the photoreceptor rail 2C of the device main body, the device is pushed in.
The photoreceptor unit is mounted on the apparatus main body, and a part of the photoreceptor unit such as the housing is fixed to the apparatus main body by the screw.

[0005] Reference numeral 3 denotes a developing rail for supporting the developing device 7 in the apparatus main body, and the rail supports a photosensitive unit as a pressed unit pressed by the cam 6 as a pressing means. The developing rail 3 extends in a direction perpendicular to the extending direction of the photoconductor rail 2C, that is, the mounting direction of the photoconductor unit. 4 is a developing rail,
A guide groove for moving in the directions A and B is a tension spring 5 for pulling the developing rail in the direction of arrow C.
Reference numeral 6 denotes a pressure lever for pressing the developing device against the photosensitive member, and reference numeral 7 denotes a housing of the developing device.

FIG. 4 (b) is a detailed view of the above-described pressurized state, and is partially in section. In this figure, 8
Is a positioning roller for pressing against the surface of the photoconductor in order to accurately gap the photoconductor 9 with the development sleeve indicated by a broken line, and is disposed coaxially with the development sleeve. Reference numeral 10 denotes a pressing cam for pushing the developing rail 3 in the pressing direction and maintaining the pressing state, which is arranged coaxially with the pressing handle 6 and rotates by the same axis as the handle. Reference numeral 11 denotes a cleaning blade for scraping off residual toner remaining on the photoreceptor after the latent image is transferred to copy paper, and reference numeral 12 denotes a charging roller for applying a charge to the photoreceptor.

FIG. 4C is a view showing a state in which the pressure of the developing unit is released in order to pull out the photoconductor unit.
By rotating the pressure handle 6 to move the cam 10 and moving the developing rail 3 in the direction C by the force of the spring 5, the state shown in the figure is achieved. Thereafter, the screw 1 is loosened to release the fixing of the photoconductor unit to the image forming apparatus main body, and the photoconductor unit is pulled out from the main body.

The relationship between the developing sleeve and the positioning rollers will be described with reference to FIG.

FIG. 5 is an exploded perspective view showing the structure of the developing device, and the PL line is a broken line. 8 is the positioning roller, 1
Reference numeral 3 denotes a developing sleeve. As is clear from the drawing, the positioning rollers are disposed coaxially with the developing sleeve, one at each end.

[0010]

As described above,
The photoconductor unit fixing screw can be loosened and pulled out without performing the pressure releasing operation of the developing device. In other words, since the photoconductor unit can be pulled out without releasing the pressure of the developing device, the positioning roller may be scratched in the latent image forming area on the photoconductor surface, or the developing unit and the photoconductor unit may interfere with each other. And may be damaged.

[0011]

In order to solve the above-mentioned drawbacks, a typical means of the present invention comprises a photosensitive drum on which an electrostatic latent image is formed by arranging electric charges on the surface, and is provided in the apparatus main body. Detachable photoreceptor unit, pressed unit pressed against the mounted photoreceptor unit side, pressing means for pressing the pressed unit toward the photoreceptor unit side, and fixing the photoreceptor unit to the apparatus body Wherein the pressed unit is separated from the drawing path of the photoconductor unit or the fixing unit when the pressed state is released, wherein the pressing unit has a shielding unit. I do.

According to the above configuration, after the pressed unit is released from the pressed state, the fixing means can be pulled out and its fixing function is released.
The user cannot remove the photoreceptor unit from the apparatus main body without hesitation, and it is possible to prevent the photoreceptor unit from interfering with or being damaged by a pressed unit such as a developing device.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] The first embodiment of the present invention
1 will be described with reference to FIGS. 1A and 1B and FIG.

The same parts as those in the conventional example are
Since the explanation has already been made, the explanation is omitted here as much as possible.

FIG. 1A shows a state in which the developing device 7 is pressed. In this figure, the photoreceptor unit 2 is detachable from the apparatus main body in a direction parallel to the rotation axis of the photosensitive drum 9, that is, in a direction perpendicular to the paper surface, and is fixed to the apparatus main body by screws as fixing means. Reference numeral 14 denotes a shutter member as shielding means provided as a pressed part so as to be able to protrude and retract from a part of a component member of the developing device 7, for example, a part of the housing 7A. To shield or open.

Reference numeral 15 denotes a gear for rotating the member 14, and reference numeral 16 denotes a member 1 by the movement of the developing unit in the directions A and B.
Reference numeral 4 denotes a rack member for rotating. Reference numeral 17 denotes a portion provided on the developing device housing 7 and concealing the fixing screw 1 from the external appearance. In the present embodiment, this alone conceals approximately half of the screw head.

FIG. 2 is a detailed view for explaining the operation of the above-mentioned auxiliary shutter 14, showing the back side of the shutter 17. As shown in FIG.
The gear 15 described above has a portion that meshes with the rack 16,
It is composed of two stages of the pulley portion on which the timing belt is applied. Reference numeral 19 denotes a timing belt which transmits rotation of the gear 15 to the shutter member 14 in the same direction.

As can be seen from the drawing, when the developing device is released, that is, when the developing device moves in the direction B, the shutter 14 rotates from the engagement of the gear 16 with the rack 16 and the shutter 14 rotates on the back of 17 which is a part of the housing 7. Is stored.

Only in this way, the user or service person can touch the fixed screw 1. FIG. 1B shows this state.

Also, when the photoreceptor unit is pulled out and set again, if the developing device is in a pressurized state, the photoreceptor unit cannot be set because it interferes with the above-mentioned shutter and housing.

Further, by using the shutter housed in the housing, the above-described effect can be realized while keeping the moving distance of the developing unit to a minimum, so that there is also an effect that the miniaturization of the main body is not hindered. .

In the present invention, as a modified example of the above embodiment, the screw 1 can be covered only by a part 17 of the housing without using the shutter 14. Further, the developing device 7 can be integrated with the photoreceptor unit 2, and in this case, a unit to be pressed by the cam 6 toward the photoreceptor unit can be used instead of the photoreceptor unit. Further, in the above-described embodiment, the shutter 14 or the part 17 of the housing as the shielding means is located on the drawing locus of the screw, but may be located on the drawing locus of the photoconductor unit itself. it can. Further, as the fixing means, the photoconductor unit can be fixed by a fixing releasing member other than the screw, which is constituted by a lever and a cam.

[Embodiment 2] A second embodiment of the present invention will be described with reference to FIGS.

The same components as those in the prior art have already been described in the prior art, and will not be described here.

FIG. 3A shows a pressed state of the developing device, and FIG.
Indicates a pressure released state.

Reference numeral 20 denotes a pressing handle for rotating the cam 6 to cover the fixing screw 1 of the photosensitive unit when pressed. Further, since this position is within the drawing locus of the photoconductor unit, the photoconductor unit cannot be pulled out unless this handle is turned to the state shown in FIG. 3B. Also, when the photoconductor unit is set again after the photoconductor unit is pulled out, the handle and the photoconductor unit cannot be set in the pressurized state due to interference.

[0027]

As described above, according to the present invention,
The fixing means of the photoreceptor unit cannot release the fixation without performing the pressing release operation of the pressed unit such as the developing device, and therefore, the latent image forming area on the surface of the photosensitive drum of the photoreceptor unit, It is possible to completely eliminate the abrasion of the positioning rollers on the pressed unit side and the breakage of the pressed unit and the photoreceptor unit due to interference, thereby improving the reliability of the apparatus.

[Brief description of the drawings]

FIG. 1 is a diagram showing a main part of an embodiment of an image forming apparatus according to the present invention.

FIG. 2 is a view showing an operation mechanism of a shutter member in FIG. 1;

FIG. 3 is a diagram showing a main part of another embodiment of the image forming apparatus according to the present invention.

FIG. 4 is a diagram illustrating an example of a conventional image forming apparatus.

FIG. 5 is a diagram showing a relationship between a developing sleeve and rollers in the image forming apparatus of FIG. 4;

FIG. 6 is a diagram illustrating an example of an overall configuration of an image forming apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Fixed screw 2 ... Photoconductor unit 2A, 7A ... Housing 3 ... Developing rail 4 ... Guide groove 5 ... Spring 6, 20 ... Press handle 7 ... Developing unit 8 ... Present sleeve 9 ... Photosensitive drum 10 ... Cam 11 ... Cleaning Blade 12 Charger 13 Positioning roller 14 Shutter 15 Gear 16 Rack 17 Part of housing 18 Shaft 19 Belt

Claims (13)

[Claims] A photosensitive drum on which an electrostatic latent image is formed by arranging an electric charge on a surface thereof; a photosensitive unit detachable from an apparatus main body; and a photosensitive member pressed toward the mounted photosensitive unit. In an image forming apparatus having a pressing unit, a pressing unit for pressing the pressed unit toward the photosensitive unit, and a fixing unit for fixing the photosensitive unit to the apparatus main body, the pressed unit is in the pressed state. An image forming apparatus comprising: a shielding unit that separates from a drawing locus of the photoconductor unit or the fixing unit in a state where is released. 2. The image forming apparatus according to claim 1, wherein the pressed unit is a developing device for developing an electrostatic latent image on the photosensitive drum. 3. The image forming apparatus according to claim 1, wherein the photosensitive unit has a photosensitive drum and a housing surrounding the photosensitive drum. 4. The image forming apparatus according to claim 1, wherein the photoconductor unit has at least one of a developing unit, a charging unit, and a cleaning unit, and a housing surrounding the unit. 5. The photoconductor unit according to claim 1, wherein the photoconductor unit is detachable from the apparatus main body in a direction parallel to a rotation axis of the photoconductor drum.
An image forming apparatus, wherein the image forming apparatus is moved in a direction orthogonal to a mounting / detaching direction of a photoconductor unit and is pressed against the photoconductor unit. 6. An image according to claim 5, wherein a positioning roller for maintaining a predetermined gap between a developing sleeve of the developing device and the photosensitive drum contacts the photosensitive drum when the developing device is pressed. Forming equipment. 7. An image forming apparatus according to claim 1, wherein said fixing means is a screw. 8. The image forming apparatus according to claim 1, wherein the shielding unit is a part of a component of the pressed unit. 9. An image forming apparatus according to claim 8, wherein said shielding means is a part of a housing of said developing device. 10. The method according to claim 5, wherein:
An image forming apparatus comprising: a shutter member which can be freely protruded and retracted from a housing of the developing device. 11. The image forming apparatus according to claim 10, wherein a gear of the developing device is engaged with a rack of the apparatus main body, and the gear and a rotating shaft of a shutter member are connected by a timing belt. 12. The method according to claim 1, wherein
The image forming apparatus according to claim 1, wherein the pressing unit includes a cam member that presses the pressed unit and an operation handle that operates the cam member. 13. An image forming apparatus according to claim 12, wherein a part of said operation handle serves as said shielding means.