JP6187294B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus.

  An image carrier module having a rotating image carrier and attached to the main body, an exposure member having an exposure unit for exposing the image carrier, a first direction that is an optical axis direction of the exposure unit, and an axis of the image carrier Positioning means for determining the position of the exposure member relative to the image carrier in a third direction orthogonal to both of the second directions, the positioning means based on the image carrier module attached to the main body An image forming apparatus is known that positions one end side of the exposure member in the second direction and positions the other end side of the exposure member in the second direction with reference to the main body (Patent Document 1).

  An image carrier that is rotatably arranged, a light-emitting array in which a plurality of light-emitting elements are arranged along the axial direction of the image carrier, and the image carrier is exposed using the light-emitting elements, and a light-emitting array A developing unit that develops the electrostatic latent image formed on the image carrier by the above, and an axial exposure position for exposing the image carrier using the light emitting array constitutes the rotating shaft of the image carrier and the developing unit An image forming apparatus is also known which is on a straight line passing through a member (Patent Document 2).

JP 2009-119844 A JP 2005-250369 A

  An object of the present invention is to provide an image forming apparatus capable of improving the accuracy of attaching an image carrier, a developing device, and an exposure device to a main body.

In order to solve the above problem, an image forming apparatus according to claim 1,
A first positioned portion, a second positioned portion, and a third positioned portion, each having an opening portion on one side and comprising a pair of two holes spaced apart from each other below the opening portion, A formed body,
An image carrier unit that supports the image carrier and is positioned on the first positioned portion when mounted on the main body;
An exposure head that is positioned on the second positioned portion and exposes the image carrier;
Wherein positioned in said third portion to be positioned when mounted on the main body includes a developing unit for developing the electrostatic latent image formed on said image hold member by the exposure head,
It said second portion to be positioned, are formed above in the vertical direction of the first portion to be positioned and / or the third of the body than the portion to be positioned,
It is characterized by that.

According to a second aspect of the present invention, in the image forming apparatus according to the first aspect,
Said second portion to be positioned, are formed above in the first vertical direction at least one said body than said mutually spaced two points a pair of holes in the portion to be positioned,
It is characterized by that.

According to a third aspect of the present invention, in the image forming apparatus according to the first aspect,
Said second portion to be positioned, are formed above in the third vertical of at least one said body than said mutually spaced two points a pair of holes in the portion to be positioned,
It is characterized by that.

According to a fourth aspect of the present invention, in the image forming apparatus according to the first aspect,
Said second portion to be positioned is of the first of said mutually spaced at least one of the two points a pair of holes and the third of said two points a pair of holes spaced from each other in the portion to be positioned of the positioning portion It is formed above the main body in the up-down direction than at least one of them,
It is characterized by that.

The invention according to claim 5 is the image forming apparatus according to any one of claims 1 to 4,
At least one of the first at least one and / or the third of the two-point pair of holes spaced from each other of the positioning portion of the mutually spaced two points a pair of holes in the portion to be positioned is, the second Formed in a horizontal range of the main body in which a pair of two holes spaced apart from each other of the positioned portion is formed.
It is characterized by that.

According to a sixth aspect of the present invention, in the image forming apparatus according to any one of the first to fifth aspects,
The image holding unit and the developing unit are positioned so as to overlap with the exposure head in the respective axial directions when mounted on the main body.
It is characterized by that.

According to the first aspect of the present invention, the image carrier unit, the developing unit, and the exposure head can be accurately positioned from the front side of the main body as compared with the case where the present configuration is not provided.
According to the second to fourth aspects of the present invention, the accuracy of attaching the image carrier unit, the developing unit, and the exposure head to the main body is improved while achieving a reduction in the size of the main body as compared with the case where the present configuration is not provided. Can be improved.
According to the fifth aspect of the present invention, it is possible to stabilize the attachment of the image carrier unit, the developing unit and the exposure head to the main body as compared with the case where the present configuration is not provided.
According to the sixth aspect of the present invention, the main body can be reduced in size as compared with the case where this configuration is not provided.

2 is a schematic cross-sectional view showing an internal configuration of the image forming apparatus 1. FIG. FIG. 2 is a schematic cross-sectional view illustrating a configuration of an image forming unit including a photoconductor unit 30, a developing unit 40, and an exposure head LH. 2 is a perspective view showing an internal state in which the photosensitive unit 30, the developing unit 40, and the exposure head LH are attached to the image forming apparatus 1. FIG. 2 is a perspective view of a main body frame 100 to which a photosensitive unit 30, a developing unit 40, and an exposure head LH are attached and positioned. FIG. 4 is a partially enlarged view showing the configuration and arrangement of a positioned portion formed on the main body frame 100. FIG. 4 is a partially enlarged view showing an arrangement in a horizontal direction of a positioned portion formed on a main body frame 100. FIG. 2 is an external front view of an image forming unit in which each photosensitive unit 30 and developing unit 40 are attached to the image forming apparatus 1. FIG.

Next, the present invention will be described in more detail with reference to the drawings with reference to embodiments and specific examples. However, the present invention is not limited to these embodiments and specific examples.
Also, in the description using the following drawings, it should be noted that the drawings are schematic and the ratio of each dimension and the like are different from the actual ones, and are necessary for the description for easy understanding. Illustrations other than the members are omitted as appropriate.
In order to facilitate understanding of the following description, in the drawings, the front-rear direction is the X-axis direction, the left-right direction is the Y-axis direction, and the up-down direction is the Z-axis direction.

(1) Overall Configuration and Operation of Image Forming Apparatus FIG. 1 is a schematic cross-sectional view showing the internal configuration of the image forming apparatus 1 according to this embodiment.
Hereinafter, the overall configuration and operation of the image forming apparatus 1 will be described with reference to the drawings.

  The image forming apparatus 1 includes a control device 10, a paper feeding device 20, a photoreceptor unit 30, a developing unit 40, a transfer unit 50, and a fixing device 60. On the upper surface (Z direction) of the image forming apparatus 1, a discharge tray 1a for discharging and storing a sheet on which an image is recorded is formed.

  The control device 10 includes an image forming device control unit 11 that controls the operation of the image forming device 1, a controller unit 12 that prepares image data according to a print processing request, an exposure control unit 13 that controls lighting of the exposure head LH, It has a power supply device 14 and the like. The power supply device 14 applies a high voltage to a charging roller 32, a developing roller 42, a primary transfer roller 52, a secondary transfer roller 53, and the like, which will be described later, and includes an exposure head LH, a paper feeding device 20, a fixing device 60, and the like. Power is supplied to each sensor.

  The controller unit 12 converts print information input from an external information transmitting apparatus (for example, a personal computer) into image information for forming a latent image and outputs a drive signal to the exposure head LH at a preset timing. . The exposure head LH of the present embodiment is configured by an LED head in which a plurality of light emitting elements (LEDs) are linearly arranged along the main scanning direction.

  A paper feeding device 20 is provided at the bottom of the image forming apparatus 1. The sheet feeding device 20 includes a sheet stacking plate 21, and a plurality of sheets P as recording media are stacked on the upper surface of the sheet stacking plate 21. The paper P loaded on the paper stacking plate 21 and whose position in the width direction is determined by a regulating plate (not shown) is pulled out one by one from the top by the paper pulling unit 22 (−X direction), and then registered. It is conveyed to the nip portion of the pair 23.

  The photoconductor unit 30 includes a photoconductor drum 31 that is provided in parallel above the paper feeding device 20 (in the Z direction) and serves as an image carrier that is rotationally driven. A charging roller 32, an exposure head LH, a developing unit 40, a primary transfer roller 52, and a cleaning blade 34 are arranged along the rotation direction of the photosensitive drum 31. A cleaning roller 33 for cleaning the surface of the charging roller 32 is disposed opposite to and in contact with the charging roller 32.

The developing unit 40 has a developing housing 41 in which a developer is accommodated. In the developing housing 41, a developing roller 42 disposed to face the photosensitive drum 31, and a pair of augers 44 that stir and convey the developer to the developing roller 42 side obliquely below the back side of the developing roller 42, 45 is arranged. A layer regulating member 46 that regulates the layer thickness of the developer is disposed in proximity to the developing roller 42.
Each of the developing units 40 is configured in substantially the same manner except for the developer contained in the developing housing 41, and each forms a toner image of yellow (Y), magenta (M), cyan (C), and black (K). To do.

  The surface of the rotating photosensitive drum 31 is charged by the charging roller 32, and an electrostatic latent image is formed by the latent image forming light emitted from the exposure head LH. The electrostatic latent image formed on the photosensitive drum 31 is developed as a toner image by the developing roller 42.

  The transfer unit 50 includes an intermediate transfer belt 51 to which each color toner image formed on the photoconductive drum 31 of each photoconductor unit 30 is transferred, and each color toner image formed on each photoconductor unit 30 to the intermediate transfer belt. A primary transfer roller 52 that sequentially transfers (primary transfer) to 51 is provided. Further, each color toner image superimposed and transferred on the intermediate transfer belt 51 is collectively transferred (secondary transfer) to the paper P as a recording medium, and a residual image attached to the intermediate transfer belt 51. An intermediate transfer belt cleaner 54 for removing toner is provided.

  Each color toner image formed on the photosensitive drum 31 of each photosensitive unit 30 is transferred to an intermediate transfer belt by a primary transfer roller 52 to which a predetermined transfer voltage is applied from a power supply device 14 or the like controlled by the image forming apparatus control unit 11. Electrostatic transfer (primary transfer) is sequentially performed on 51, and a superimposed toner image in which toners of respective colors are superimposed is formed.

  The superimposed toner image on the intermediate transfer belt 51 is conveyed to a region (secondary transfer portion TR) where the secondary transfer roller 53 is disposed as the intermediate transfer belt 51 moves. When the superimposed toner image is conveyed to the secondary transfer unit TR, the paper P is supplied from the paper feeding device 20 to the secondary transfer unit TR in accordance with the timing. Then, a predetermined transfer voltage is applied to the secondary transfer roller 53 from the power supply device 14 or the like controlled by the image forming apparatus controller 11, and the secondary transfer roller 53 is fed from the registration roller pair 23 to the sheet P guided by the conveyance guide. Multiple toner images on the intermediate transfer belt 51 are collectively transferred.

  Residual toner on the surface of the photosensitive drum 31 is removed by the cleaning blade 34 and collected in a waste toner collection container (not shown). The surface of the photosensitive drum 31 is recharged by the charging roller 32. Residues that cannot be completely removed by the cleaning blade 34 and adhere to the charging roller 32 are captured and accumulated on the surface of the cleaning roller 33 that rotates in contact with the charging roller 32.

The fixing device 60 includes a heating module 61 and a pressure module 62, and a fixing nip portion N (fixing area) is formed by a pressure contact area between the heating module 61 and the pressure module 62.
The sheet P on which the toner image is transferred in the transfer device 50 is conveyed to the fixing device 60 via the conveyance guide in a state where the toner image is not fixed. The toner image is fixed on the sheet P conveyed to the fixing device 60 by a pair of heating module 61 and pressure module 62 by the action of pressure bonding and heating.
The sheet P on which the fixed toner image is formed is guided by the conveyance guides 65 a and 65 b and is discharged from the discharge roller pair 69 to the discharge tray 1 a on the upper surface of the image forming apparatus 1.

(2) Mounting Structure of Photosensitive Unit, Developing Unit, and Exposure Unit FIG. 2 is a schematic cross-sectional view showing the configuration of an image forming unit including the photosensitive unit 30, the developing unit 40, and the exposure head LH, and FIG. FIG. 4 is a perspective view showing an internal state in which the developing unit 40 and the exposure head LH are attached to the image forming apparatus 1. FIG. 4 is a perspective view of the main body frame 100 to which the photosensitive unit 30, the developing unit 40, and the exposure head LH are attached and positioned. FIG. 5 is a partially enlarged view showing the configuration and arrangement of the positioned portion formed on the main body frame 100, and FIG. 6 is a diagram for explaining the arrangement in the horizontal direction of the positioned portion formed on the main body frame 100. FIG. 7 is a partially enlarged view, and FIG. 7 is an external front view of an image forming unit in which each photosensitive unit 30 and developing unit 40 are attached to the image forming apparatus 1. FIG.
Hereinafter, the mounting structure of the photoconductor unit 30, the developing unit 40, and the exposure head LH will be described with reference to the drawings.

(2.1) Configuration of Image Forming Unit As shown in FIG. 2, the image forming unit composed of the photosensitive unit 30, the developing unit 40, and the exposure head LH is centered on the photosensitive drum 31 below the intermediate transfer belt 51. The charging roller 32, the developing roller 42, and the exposure head LH are arranged.

The exposure head LH is fixed to a second positioned portion 102 of the main body frame 100 described later in a state of being close to the surface of the photosensitive drum 31.
The photosensitive unit 30 including the photosensitive drum 31 and the developing unit 40 including the developing roller 42 are respectively positioned with respect to the main body frame 100 such that the exposure head LH is sandwiched from both sides in the axial direction. It is being fixed to the to-be-positioned part 103 of this.

The photoconductor unit 30 and the developing unit 40 are replaced each time based on the determined number of image formations. On the other hand, the exposure head LH is used until the apparatus lifetime determined by the image forming apparatus 1 is reached unless a failure or the like occurs.
For this purpose, in the image forming unit, the exposure head LH is fixed to the main body frame 100 by the second positioned portion 102 in a state of overlapping the photoconductor unit 30 and the development unit 40 in the axial direction, and the photoconductor unit 30 and the development unit. The unit 40 is detachably fixed to the user with the exposure head LH fixed to the main body frame 100.

(2.2) Attachment / Removal of Photoreceptor Unit and Development Unit As shown in FIG. 3, the main body frame 100 of the image forming apparatus 1 is provided with each photoreceptor unit 30 and each development unit from the front side (Y direction in FIG. 3). 40 is attached (arrow R1 in FIG. 3) and fixed.
A transfer unit 50 is mounted above each photoconductor unit 30 and each development unit 40.

Each photoconductor unit 30 is attached to and detached from the main body frame 100 from the front side, and is fixed to the main body frame 100 via a front cover 30A by a fixing knob NB.
Similarly, the developing unit 40 is also attached to and detached from the main body frame 100 in the Y direction, and is fixed to the main body frame 100 via the front cover 40A with fixing screws S1.
The transfer unit 50 rotates the operation handle 501 so that all the primary transfer rollers 52 (Y), (M), (C), (K) and the tension roller 55 are separated from the photosensitive drum 31 (maintenance). Position) with respect to the main body frame 100 in the Y direction.

(2.3) Positioned Position of Main Body Frame As shown in FIG. 4, the main body frame 100 is formed with an opening 110 on each side (front side) to which each photoreceptor unit 30 and each developing unit 40 can be attached and detached. Has been.
Below the opening 110 in the vertical direction of the main body frame 100 (Z direction in FIG. 4), a first positioned portion 101 to which each photoreceptor unit 30 is fixed and a second to which each exposure head LH is fixed. The positioned portion 102 and the third positioned portion 103 to which the developing units 40 are fixed are formed as four sets in the horizontal direction (X direction in FIG. 4).

  Refer to FIG. 5 for specific configurations and arrangements of the first positioned portion 101, the second positioned portion 102, and the third positioned portion 103 formed in the main body frame 100 configured as described above. While explaining.

As shown in FIG. 5, the first positioned portion 101, the second positioned portion 102, and the third positioned portion 103 provided below the opening 110 of the main body frame 100 are separated from each other by 2. It consists of a pair of holes (illustrated by hatching in FIG. 5).
In the first positioned portion 101, the pair of two holes includes a first positioning hole 101a and a second positioning hole 101b. The first positioning hole 101a is provided in the front cover 30A of each photoconductor unit 30. The positioning pin 30Aa (see FIG. 2) is formed as a circular hole into which the positioning pin 30Aa (see FIG. 2) is inserted, and serves as a positioning reference hole.
The second positioning hole 101b is a long hole in the horizontal direction (X direction), and a positioning pin 30Aa provided on the front cover 30A of each photoconductor unit 30 is inserted into the second positioning hole 101b. The rotational movement around the one positioning hole 101a is restricted.

Similarly, the second positioned portion 102 includes a circular first positioning hole 102a and a long second positioning hole 102b, and a positioning pin provided in the exposure head LH is fitted therein.
Similarly, the third positioned portion 103 includes a circular first positioning hole 103a serving as a positioning reference hole and a long second positioning hole 103b that restricts rotational movement. The positioning pin 40Aa (see FIG. 2) provided in the is inserted.

FIG. 5 also shows an example of arrangement positions of the first positioned portion 101, the second positioned portion 102, and the third positioned portion 103.
In the present embodiment, the second positioned portion 102 to which each exposure head LH is fixed is the first positioned portion to which each photoconductor unit 30 is fixed in the vertical direction (Z direction) of the main body frame 100. 101 and each developing unit 40 are arranged above (in the Z direction) the third positioned portion 103 to which the developing unit 40 is fixed.
That is, the first positioned portion 101 of the photoconductor unit 30 and the third positioned portion 103 of the developing unit 40 are the second positioned portion 102 of the exposure head LH in the horizontal direction (X direction) of the main body frame 100. It is arranged without overlapping.

As a result, in a state where the exposure head LH is positioned and fixed to the main body frame 100, the photoconductor unit 30 and the developing unit 40 are not restricted by the fixing position of the exposure head LH, and the horizontal direction of the main body frame 100 (X direction). ) And are positioned and fixed close to each other.
For this purpose, the image forming units including the photoconductor unit 30, the exposure head LH, and the developing unit 40 are arranged close to each other at a narrow interval (pitch p), and the image forming apparatus 1 is further downsized in the horizontal direction (X direction). (See FIG. 7).

FIG. 6 shows that in the horizontal direction (X direction) of the main body frame 100, a part of the range X1 of the positioned portion 101 of the photoconductor unit 30 is part of the range X2 of the second positioned portion 102 to which the exposure head LH is fixed. The state which has overlapped with the part is shown.
Specifically, the second positioning hole 101b constituting the first positioned portion 101 of the photoconductor unit 30 is disposed so as to overlap the second positioning portion 102 of the exposure head LH in the X direction.

As a result, in the horizontal direction (X direction) of the main body frame 100, the first positioned portion 101 of the photosensitive unit 30 does not interfere with the second positioned portion 102 to which the exposure head LH is fixed. The 1 positioning hole 101a and the 2nd positioning hole 101b are arrange | positioned at a mutually wide space | interval.
For this reason, when the photosensitive unit 30 is fixed below the main body frame 100, the positioning position (first positioning hole 101a) and the rotation restricting position (second positioning hole 101b) are further separated to suppress backlash. Can be fixed.

  Similarly, in the horizontal direction (X direction) of the main body frame 100, a part of the range X3 of the third positioned portion 103 of the developing unit 40 is a range X2 of the second positioned portion 102 to which the exposure head LH is fixed. When the first positioning hole 103a and the second positioning hole 103b of the third positioned portion 103 of the developing unit 40 are arranged at a wider interval, the rattling is suppressed. Fixed.

(3) Action / Effect In the present embodiment, the first positioned portion 101 to which each photoconductor unit 30 is fixed and each exposure head LH are fixed below the opening 110 in the vertical direction of the main body frame 100. The second positioned portion 102 and the third positioned portion 103 to which each developing unit 40 is fixed are formed as four sets in the horizontal direction.
In the second positioned portion 102 to which each exposure head LH is fixed, the first positioned portion 101 to which each photoconductor unit 30 is fixed and each developing unit 40 are fixed in the vertical direction of the main body frame 100. It is arranged above the third positioned part 103 (Z direction).

  Therefore, in the state where the exposure head LH is positioned and fixed to the main body frame 100, the photoconductor unit 30 and the developing unit 40 are not restricted by the fixing position of the exposure head LH, and the horizontal direction of the main body frame 100 (X direction) ), The image forming units are arranged close to each other at a narrow interval (pitch), and the image forming apparatus 1 is further downsized in the horizontal direction (X direction).

Further, the second positioning hole 101b constituting the first positioned portion 101 of the photosensitive unit 30 is arranged so as to overlap the second positioned portion 102 of the exposure head LH in the X direction.
Therefore, in the horizontal direction (X direction) of the main body frame 100, the first positioned portion 101 of the photosensitive member unit 30 does not interfere with the second positioned portion 102 to which the exposure head LH is fixed. The first positioning hole 101a and the second positioning hole 101b are arranged at a wide interval, and when the photosensitive unit 30 is fixed below the main body frame 100, the positioning position (first positioning hole 101a) and the rotation restriction position (first 2 The positioning holes 101b) can be further spaced apart and can be fixed while suppressing backlash.

1 ... Image forming apparatus discharge tray 1a
10 ... Control device 20 ... Paper feeding device
DESCRIPTION OF SYMBOLS 30 ... Photosensitive unit 30A ... Front cover 30Aa ... Positioning pin 31 ... Photosensitive drum 32 ... Charge roller 40 ... Developing unit 40A ... Front cover 40Aa ... Positioning pin 41 ... developing housing 42 ... developing roller 50 ... transfer unit 51 ... intermediate transfer belt
52... Primary transfer roller 60... Fixing device 100... Main body frame 101... First positioned portion 101 a.
101b ... second positioning hole
102: Second positioning portion 102a: First positioning hole 102b: Second positioning hole 103: Third positioning portion 103a: First positioning hole 103b: Second Positioning hole
110 ... opening
LH ... Exposure head

Claims (6)

A first positioned portion, a second positioned portion, and a third positioned portion, each having an opening portion on one side and comprising a pair of two holes spaced apart from each other below the opening portion, A formed body,
An image carrier unit that supports the image carrier and is positioned on the first positioned portion when mounted on the main body;
An exposure head that is positioned on the second positioned portion and exposes the image carrier;
Wherein positioned in said third portion to be positioned when mounted on the main body includes a developing unit for developing the electrostatic latent image formed on said image hold member by the exposure head,
It said second portion to be positioned, are formed above in the vertical direction of the first portion to be positioned and / or the third of the body than the portion to be positioned,
An image forming apparatus. Said second portion to be positioned, are formed above in the first vertical direction at least one said body than said mutually spaced two points a pair of holes in the portion to be positioned,
The image forming apparatus according to claim 1. Said second portion to be positioned, are formed above in the third vertical of at least one said body than said mutually spaced two points a pair of holes in the portion to be positioned,
The image forming apparatus according to claim 1. Said second portion to be positioned is of the first of said mutually spaced at least one of the two points a pair of holes and the third of said two points a pair of holes spaced from each other in the portion to be positioned of the positioning portion It is formed above the main body in the up-down direction than at least one of them,
The image forming apparatus according to claim 1. At least one of the first at least one and / or the third of the two-point pair of holes spaced from each other of the positioning portion of the mutually spaced two points a pair of holes in the portion to be positioned is, the second Formed in a horizontal range of the main body in which a pair of two holes spaced apart from each other of the positioned portion is formed.
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. The image holding unit and the developing unit are positioned so as to overlap with the exposure head in the respective axial directions when mounted on the main body.
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.

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