JP2011020414A - Image forming apparatus and exposure apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain an exposure member from being positioned in a shifted state from a position in an optical axis direction where it should be originally set. <P>SOLUTION: An advancing/retreating mechanism 17 includes a lifting member 306 supporting an LPH (LED print head) as an example of the exposure member; a front cam 305F and a rear cam 305R moving the LPH between a retreat position and an exposure position through the lifting member 306 by rotation; and a second link member 302 rotating the front cam 305F and the rear cam 305R. The lifting member 306 is formed with a front elongated hole and a rear elongated hole which a front shaft of the front cam 305F and a rear shaft of the rear cam 305R penetrate. The front and rear elongated holes are provided to incline in an X-direction toward a Z-direction. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image forming apparatus and an exposure apparatus.

In image forming apparatuses such as printers and copiers using an electrophotographic system, light emitting elements such as LEDs (Light Emitting Diodes) have recently been arranged in a line as an exposure member that exposes an image carrier such as a photosensitive drum. A device using the light emitting element array has been proposed.
In such an image forming apparatus, it is required to position the exposure member relative to the image carrier in the optical axis direction of the exposure member.

  As a conventional technique described in the publication, there is a technique for positioning the exposure member in the optical axis direction by pressing the exposure member against the image carrier using an advancing / retreating mechanism that advances and retracts the exposure member in the optical axis direction with respect to the image carrier. (See Patent Document 1).

JP 2008-20845 A

  Here, an object of the present invention is to prevent the exposure member from being positioned in a state of being deviated from the position in the optical axis direction that should be originally set.

  According to a first aspect of the present invention, an image carrier, an exposure member that exposes the image carrier, a retracted position where the exposure member is separated from the image carrier, and a position closer to the image carrier than the retracted position. A support member for supporting the exposure member so as to move between exposure positions; a rotating shaft whose position is fixed; and a rotating body attached to the rotating shaft and connected to the supporting member. Accordingly, the exposure member is moved from the retracted position toward the exposure position, and the exposure member is moved from the retracted position to the exposure position via the support member by rotating the moving member. In this case, the support member is adjusted so that the angle difference between the direction of the force received by the support member via the moving member and the direction of movement of the support member is smaller at the exposure position than at the retracted position. An image forming apparatus including a guide means for the inner.

According to a second aspect of the present invention, when the guide means moves the exposure member from the retracted position to the exposure position via the support member, the guide means in advance in a direction from the exposure member toward the image carrier. 2. The image forming apparatus according to claim 1, wherein the support member is guided in a direction inclined to a predetermined side.
A third aspect of the present invention is the image forming apparatus according to the first or second aspect, wherein the guide means guides the support member linearly.
The invention according to claim 4 is characterized in that the guide means guides the support member so that the angular difference changes linearly when the exposure member is moved from the retracted position to the exposure position. The image forming apparatus according to any one of claims 1 to 3.
According to a fifth aspect of the present invention, when the guide member moves the exposure member from the retracted position to the exposure position via the support member, the angular difference is minimized at the exposure position. The image forming apparatus according to claim 1, wherein the support member is guided.

  According to a sixth aspect of the present invention, there is provided an exposure member for exposing the image carrier, a retracted position where the exposure member is separated from the image carrier, and an exposure position where the image carrier is closer to the image carrier than the retracted position. A support member that supports the exposure member so as to move; a rotating shaft that is fixed in position; and a rotating body that is attached to the rotation shaft and connected to the support member. A moving member that moves from the retracted position toward the exposure position, and the moving member when the exposure member is moved from the retracted position to the exposure position via the support member by rotating the moving member. Guiding means for guiding the support member so that an angular difference between the direction of the force received by the support member via the direction and the direction of movement of the support member is smaller at the exposure position than at the retracted position. An exposure device including a.

  According to a seventh aspect of the present invention, there is provided an image holding member, an exposure member having an exposure unit that exposes the image holding member, and a first retracting position from a predetermined retracted position in a first direction that is an optical axis direction of the exposure unit. The exposure member is moved to move the exposure unit to a predetermined exposure position with respect to the image carrier, and the exposure member is moved from the exposure position in a direction opposite to the first direction. An advancing / retreating mechanism that retracts the image holding member at the retracting position, and the advancing / retreating mechanism is provided along a second direction from one end side to the other end side of the image holding member in the axial direction of the image holding member, A housing that is fixed in position relative to the image carrier, and a shaft that extends in a third direction intersecting the first direction and the second direction and is attached in a state where the position is fixed to the housing. And a rotating body that rotates about the axis. A rotating member and a long hole through which the shaft of the rotating member penetrates are mounted. The exposure member is mounted and connected to the rotating body of the rotating member, and the exposure member is retracted as the rotating body rotates. A mounting member that is moved to a position or the exposure position, and a direction of a force received by the mounting member via the rotating member when the mounting member is moved from the retracted position to the exposure position. The image forming apparatus is characterized in that an angle difference from the direction of the elongated hole is smaller at the exposure position than at the retracted position.

According to an eighth aspect of the present invention, the slot provided in the mounting member is inclined in either the second direction or a direction opposite to the second direction. 8. The image forming apparatus according to claim 7, wherein the image forming apparatus is formed.
The invention according to claim 9 is the image forming apparatus according to claim 7 or 8, wherein the elongated hole provided in the mounting member has a linear shape.
The invention according to claim 10 is characterized in that the angular difference is minimized at the exposure position while the mounting member is moved from the retracted position to the exposure position. An image forming apparatus according to item 1.

According to the first aspect of the present invention, the exposure member is originally set as compared with the case where the angular difference between the direction of the force received by the support member and the direction of movement of the support member is larger at the exposure position than at the retracted position. Positioning in a state of being deviated from the position in the optical axis direction to be performed can be suppressed.
According to the second aspect of the present invention, the support member is guided in both the direction inclined to the predetermined side with respect to the direction from the exposure member toward the image carrier and the direction inclined opposite to the direction. In comparison, the position of the exposure member can be prevented from shifting during the movement of the exposure member.
According to the third aspect of the present invention, the support member can be guided more easily than when the support member is guided non-linearly.
According to the fourth aspect of the present invention, it is possible to suppress the displacement in the positioning of the exposure member as compared with the case where the support member is guided so that the angle difference changes nonlinearly.
According to the fifth aspect of the present invention, as compared with the case where the support member is guided so that the angle difference is not minimized at the exposure position, it is possible to further suppress the positional deviation in the positioning of the exposure member.
According to the sixth aspect of the present invention, the exposure member is originally set as compared with the case where the angle difference between the direction of the force received by the support member and the direction of movement of the support member is larger at the exposure position than at the retracted position. Positioning in a state of being deviated from the position in the optical axis direction to be performed can be suppressed.
According to the seventh aspect of the present invention, the exposure is compared with the case where the angle difference between the direction of the force received by the mounting member and the direction of the slot provided in the mounting member is larger at the exposure position than at the retracted position. It is possible to prevent the member from being positioned in a state of being deviated from the position in the optical axis direction to be originally set.
According to the invention described in claim 8, compared with the case where the elongated hole provided in the mounting member is inclined in both the second direction and the opposite direction to the second direction. Thus, the position of the exposure member can be prevented from shifting during the movement of the exposure member.
According to the ninth aspect of the present invention, the mounting member can be guided more easily than when the mounting member is guided non-linearly.
According to the tenth aspect of the present invention, it is possible to further suppress the positional deviation in the positioning of the exposure member as compared with the case where the mounting member is guided so that the angle difference is not minimized at the exposure position.

1 is a diagram illustrating an example of a configuration of an image forming apparatus to which the exemplary embodiment is applied. It is sectional drawing which showed the structure of LPH. It is a top view of a LED circuit board. It is a figure which shows the circuit structure of a LED chip, a signal generation circuit, and a level shift circuit. FIG. 3 is a perspective view showing a state where a photoconductor module and an exposure module are attached to an image forming apparatus. FIG. 6 is an enlarged view of the front side in FIG. 5. FIG. 6 is an enlarged view of the rear side in FIG. 5. It is a perspective view which shows the structure of a photoconductor module. It is a perspective view which shows the structure of an exposure module. It is a perspective view which shows the structure of LPH in an exposure module. It is a perspective view which shows the structure of the advance / retreat mechanism in an exposure module. It is a figure for demonstrating the front control member provided in the advance / retreat mechanism. It is a perspective view which shows the structure of the raising / lowering member provided in the advance / retreat mechanism. It is a front view which shows the structure of the raising / lowering member provided in the advance / retreat mechanism. It is a perspective view which shows the structure of the cam (front cam, rear cam) provided in the advance / retreat mechanism. (A) is the top view which looked at the advance / retreat mechanism from Z direction, (b) is the side view which looked at the advance / retreat mechanism from Y direction, (c) is AA sectional drawing of (a). It is a perspective view which shows the principal part of the link mechanism in an advance / retreat mechanism. It is a perspective view which shows the positional relationship of the raising / lowering member, front cam, and front coil spring in an advance / retreat mechanism. It is a perspective view which shows the structure of a front positioning member. It is a perspective view which shows the structure of a rear holding member. (A)-(c) is a figure for demonstrating the state of the advancing / retreating mechanism in each of an exposure position, a standby position, and a retracted position. It is a figure for demonstrating the state of the front side of the advancing / retreating mechanism when setting to a retracted position. It is a figure for demonstrating the state of the rear side of the advancing / retreating mechanism when setting to a retracted position. It is a figure for demonstrating the state of the front side of the advancing / retreating mechanism at the time of setting to an exposure position. It is a figure for demonstrating the state of the rear side of the advancing / retreating mechanism at the time of setting to an exposure position. When operating the advance / retreat mechanism from the retracted position toward the exposure position, the relationship between the direction of the force received by the elevating member via the front cam and the direction of the elevating member moving by the received force on the front side of the advance / retreat mechanism It is a figure for demonstrating. When operating the advance / retreat mechanism from the retracted position toward the exposure position, the relationship between the direction of the force received by the elevating member via the rear cam and the direction in which the elevating member moves by the received force on the rear side of the advance / retract mechanism is explained. It is a figure for doing. (A) is a figure which shows the relationship between the rotation angle of a front cam, the direction of the force which a raising / lowering member receives via a front cam, and the angle difference of the direction which a raising / lowering member moves with the received force, (b) It is a figure which shows the relationship between the angle force and the frictional force which acts between the front axis | shaft provided in the front cam with the raising operation of the raising / lowering member, and the inner wall of the front long hole provided in the raising / lowering member. It is a figure for demonstrating the modification of this Embodiment.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a diagram illustrating an example of a configuration of an image forming apparatus 1 to which the exemplary embodiment is applied. The image forming apparatus 1 shown in FIG. 1 is a so-called tandem color printer, and an image forming process unit 10 that forms an image corresponding to image data of each color, and a control unit 30 that controls the operation of the entire image forming apparatus 1. An image processing unit 35 that is connected to an external device such as a personal computer (PC) 3 or an image reading device 4 and performs image processing on image data received from these devices, and a main power source 36 that supplies power to each unit. I have.

  The image forming process unit 10 includes four image forming units 11Y, 11M, 11C, and 11K (hereinafter collectively referred to simply as “image forming unit 11”) that are arranged in parallel at regular intervals. It has been. Each image forming unit 11 is rotatably arranged to form an electrostatic latent image and to hold a toner image, a photoconductor drum 12 as an example of an image carrier, a charger 13 that charges the surface of the photoconductor drum 12, An LED print head (LPH) 14 as an example of an exposure member that exposes the photosensitive drum 12 charged by the charger 13 based on image data, and development that develops the electrostatic latent image formed on the photosensitive drum 12. And a cleaner 16 for cleaning the surface of the photosensitive drum 12 after transfer. Note that the photosensitive drum 12 in the present exemplary embodiment includes a rotation shaft (not shown) so that the axial direction is directed from the front side (front side in the figure) to the rear side (back side in the figure) of the image forming apparatus 1. Is arranged.

  Further, each image forming unit 11 advances the LPH 14 to an exposure position where the photosensitive drum 12 is exposed, and the advance / retreat mechanism 17 retracts the LPH 14 to a retracted position that is further away from the photosensitive drum 12 than the exposure position. It has. Here, each image forming unit 11 has the same configuration except for the toner stored in the developing device 15. Each image forming unit 11 forms yellow (Y), magenta (M), cyan (C), and black (K) toner images.

  Further, the image forming process unit 10 includes an intermediate transfer belt 20 onto which each color toner image formed on the photosensitive drum 12 of each image forming unit 11 is transferred, and each color toner image from each image forming unit 11 to the intermediate transfer belt. A primary transfer roll 21 that is sequentially transferred to the intermediate transfer belt 20, a secondary transfer roll 22 that batch-transfers the superimposed toner image transferred onto the intermediate transfer belt 20 onto a sheet as a recording material, and a secondary transferred image is fixed on the sheet. A fixing device 45 is provided.

Here, in each image forming unit 11, the photoconductor drum 12, the charger 13 and the cleaner 16 are configured as an integrated module (hereinafter referred to as a photoconductor module PM: see FIG. 5 described later). . The photoreceptor module PM is configured to be detachable from the image forming apparatus 1 and is exchanged according to the life of the photoreceptor drum 12 or the like. The photoreceptor module PM may adopt a configuration of only the photosensitive drum 12 that does not include the charger 13 and the cleaner 16, or a configuration in which the developing device 15 is further integrated in addition to the charger 13 and the cleaner 16. It may be adopted. That is, the photoconductor module PM may be configured by any combination of components as long as the photoconductor drum 12 includes a photoconductor drum 12 whose lifetime is shorter than that of other components. It is assumed that the photoconductor module PM and the LPH 14 are separated.
In each image forming unit 11, the LPH 14 and the advance / retreat mechanism 17 are also configured as an integrated module (hereinafter referred to as an exposure module EM: see FIG. 5 described later). An exposure module EM as an example of an exposure apparatus is also configured to be detachable from the image forming apparatus 1. The detailed configuration of the photoreceptor module PM and the exposure module EM will be described later.

  In the image forming apparatus 1, the image forming process unit 10 performs an image forming operation based on various control signals supplied from the control unit 30. That is, image data input from the PC 3 or the image reading device 4 under the control of the control unit 30 is subjected to image processing by the image processing unit 35 and supplied to each image forming unit 11 via an interface (not shown). Is done. For example, in the black (K) image forming unit 11K, the photosensitive drum 12 is charged to a predetermined potential by the charger 13 while rotating in the direction of arrow A, and the image transmitted from the image processing unit 35 is transmitted. The exposure is performed by the LPH 14 that emits light based on the data. As a result, an electrostatic latent image related to a black (K) color image is formed on the photosensitive drum 12. The electrostatic latent image formed on the photosensitive drum 12 is developed by the developing device 15, and a black (K) toner image is formed on the photosensitive drum 12. Similarly, yellow (Y), magenta (M), and cyan (C) toner images are formed in the image forming units 11Y, 11M, and 11C, respectively.

  The respective color toner images formed by the respective image forming units 11 are sequentially electrostatically attracted by the primary transfer roll 21 onto the intermediate transfer belt 20 moving in the direction of arrow B to form a composite toner image in which the respective color toners are superimposed. Is done. The synthetic toner image on the intermediate transfer belt 20 is conveyed to a region (secondary transfer portion T) where the secondary transfer roll 22 is disposed as the intermediate transfer belt 20 moves. When the composite toner image is conveyed to the secondary transfer unit T, the paper is supplied from the sheet holding unit 40 to the secondary transfer unit T in accordance with the timing at which the synthetic toner image is conveyed to the secondary transfer unit T. The composite toner image is collectively electrostatically transferred onto the conveyed paper by the transfer electric field formed by the secondary transfer roll 22 in the secondary transfer portion T.

Thereafter, the sheet on which the synthetic toner image has been electrostatically transferred is peeled off from the intermediate transfer belt 20 and conveyed to the fixing device 45. The synthesized toner image on the paper conveyed to the fixing device 45 is fixed on the paper by the fixing device 45 by a fixing process using heat and pressure. Then, the sheet on which the fixed image is formed is conveyed to the paper discharge stacking unit 41 provided in the discharge unit of the image forming apparatus 1.
On the other hand, toner (transfer residual toner) adhering to the intermediate transfer belt 20 after the secondary transfer is removed from the surface of the intermediate transfer belt 20 by the belt cleaner 25 after the completion of the secondary transfer to prepare for the next image forming cycle. In this way, image formation in the image forming apparatus 1 is repeatedly executed for the number of printed sheets.

  FIG. 2 is a cross-sectional view showing the configuration of the LPH 14. The LPH 14 is disposed below the photosensitive drum 12 in the image forming apparatus 1 shown in FIG. 1, and exposes the photosensitive drum 12 from below. As shown in FIG. 2, the LPH 14 includes a housing 61, an LED array 63, an LED circuit board 62 on which an LED array 63, a signal generation circuit 70 for driving the LED array 63 (see FIG. 3), and the like are mounted. Are provided with a rod lens array 64 that forms an image on the surface of the photosensitive drum 12, and a holder 65 that supports the rod lens array 64 and shields the LED array 63 from the outside. In the present embodiment, the exposure portion is formed by the LED array 63, the rod lens array 64, and the like.

  The housing 61 is formed of a metal block such as aluminum or SUS or a sheet metal, and supports the LED circuit board 62. The rod lens array 64 is disposed along the axial direction of the photosensitive drum 12 and has a width in the rotational direction of the photosensitive drum 12. Further, the rod lens array 64 is configured by arranging a plurality of gradient index lenses that form an erecting equal-magnification real image. The holder 65 is formed in a long shape and is disposed along the axial direction of the photosensitive drum 12. The holder 65 supports the housing 61 and the rod lens array 64, and is set so that the light emitting point of the LED array 63 and the focal plane of the rod lens array 64 coincide. Furthermore, the holder 65 is configured to seal the LED array 63. As a result, a configuration in which dust does not easily adhere to the LED array 63 from the outside is realized. Further, the holder 65 is disposed along the longitudinal direction (the axial direction of the photosensitive drum 12) on both side surfaces in the width direction, and guide grooves 65a for guiding the slide of a slide member 67 (see FIG. 10 at a later stage) to be described later. It has.

As shown in FIG. 3 (plan view of the LED circuit board 62), the LED circuit board 62 includes an LED array 63 composed of 58 LED chips (CHIP1 to CHIP58), for example, in the axial direction of the photosensitive drum 12. It is arranged in a line with high accuracy so as to be parallel. In this case, each LED chip is arranged such that each LED is continuously arranged at a connection portion between the LED chips at the end boundary of the arrangement of the light emitting elements (LEDs) arranged in each LED chip (CHIP1 to CHIP58). Are alternately arranged in a staggered pattern.
The LED circuit board 62 includes a signal generation circuit 70 and a level shift circuit 74 that generate a drive signal for driving each LED chip, a three-terminal regulator 71 that outputs a predetermined voltage, and each LED chip. A harness 73 is provided that receives signals from the EEPROM 72 that stores LED light quantity correction data, the control unit 30, and the image processing unit 35 (see FIG. 1) and receives power from the main power source 36. Note that the signal generation circuit 70, the three-terminal regulator 71, the EEPROM 72, the harness 73, and the level shift circuit 74 shown in FIG. 3 are not necessarily attached to the LED circuit board 62, and may be attached to other boards. Good.

Here, FIG. 4 is a diagram showing a circuit configuration of the LED chip, the signal generation circuit 70 and the level shift circuit 74. In this LED chip, various drive signals are supplied via the signal generation circuit 70 and the level shift circuit 74. That is, the signal generation circuit 70 includes the transfer signals CK1R and CK1C and the transfer signals CK2R and CK2C that are sequentially set in a lighting-enabled state along each LED arranged on the LED chip, and the image processing unit 35 (see FIG. 1). A lighting signal ΦI for sequentially lighting each LED is generated based on the image data from. Then, the transfer signals CK1R and CK1C and the transfer signals CK2R and CK2C are output to the level shift circuit 74, and the lighting signal ΦI is output to the LED chip.
The level shift circuit 74 has a configuration in which a resistor R1B and a capacitor C1, and a resistor R2B and a capacitor C2 are connected in parallel, one end of which is connected to the input terminal of the LED chip, and the other end is a signal generation circuit. 70 output terminals. Then, the level shift circuit 74 generates the transfer signal CK1 and the transfer signal CK2 based on the transfer signals CK1R and CK1C and the transfer signals CK2R and CK2C output from the signal generation circuit 70, and outputs them to the LED chip.

On the other hand, the LED chip of the present embodiment includes, for example, 128 thyristors S1 to S128 as switch elements, 128 LEDs L1 to L128 as light emitting elements, 128 diodes D1 to D128, and 128 resistors R1 to R1. R128, and further, transfer current limiting resistors R1A and R2A that prevent excessive current from flowing through the signal lines Φ1 and Φ2 are main components.
The anode terminals A1 to A128 of the thyristors S1 to S128 are connected to the power supply line 55, and the drive voltage VDD (VSS = + 3.3V) is supplied from the three-terminal regulator 71 (see FIG. 3) via the power supply line. . On the other hand, the gate terminals G1 to G128 of the thyristors S1 to S128 are respectively connected to the power supply line 56 via resistors R1 to R128 provided corresponding to the thyristors S1 to S128, and are grounded via the power supply line 56. Yes.

  Further, the transfer signal CK1 from the signal generation circuit 70 and the level shift circuit 74 is transmitted to the cathode terminals K1, K2,..., K127 of the odd-numbered thyristors S1, S3,. Is done. To the even-numbered thyristors S2, S4,..., S128, the transfer signal CK2 from the signal generation circuit 70 and the level shift circuit 74 is transmitted via the transfer current limiting resistor R2A. Further, the cathode terminals of the LEDs L1 to L128 are connected to the signal generation circuit 70, and the lighting signal ΦI is transmitted.

  The signal generation circuit 70 sets the transfer signals CK1R and CK1C and the transfer signals CK2R and CK2C from a high level (hereinafter referred to as “H”) to a low level (hereinafter referred to as “L”) at predetermined timings. ) And “L” to “H”. As a result, the potential of the transfer signal CK1 output from the level shift circuit 74 is repeatedly set from “H” to “L”, “L” to “H”, and the transfer signal CK2 output alternately is transferred to the transfer signal CK2. By repeatedly setting the potential from “H” to “L” and from “L” to “H”, for example, in each LED chip, the odd-numbered thyristors S1, S3,..., S127 are sequentially turned off → on → off. To do. Further, the even-numbered thyristors S2, S4,..., S128 are sequentially transferred from OFF to ON to OFF. As a result, a transfer operation for sequentially turning off, on, and turning off the thyristors S1 to S128 in the order of S1, S2,..., S127, and S128 is performed, and the lighting signal ΦI is output in synchronization with the transfer operation. As a result, the LEDs L1 to L128 are sequentially turned on in the order of L1 → L2 →... → L127 → L128.

  In this case, the exposure from the LPH 14 is preferably performed in parallel to the axis of the photosensitive drum 12 so that the formed image (electrostatic latent image) is not tilted or distorted. Therefore, when the LPH 14 is installed in the image forming apparatus 1, it is required that the LPH 14 be positioned with high accuracy with respect to the axis of the photosensitive drum 12. Here, the axis of the photosensitive drum 12 (image holding member) is the center of the rotation axis of the photosensitive drum 12 when the image holding member has a cylindrical shape like the photosensitive drum 12 of the present embodiment. The line is an axis. Further, for example, when the image carrier is a belt-shaped photoconductor (belt photoconductor), and exposure is performed on a flat portion of the belt photoconductor, the exposure is perpendicular to the moving direction of the surface of the belt photoconductor and the exposure is performed. A line extending in a direction parallel to the belt photoreceptor surface in the region is an axis.

Next, the positioning mechanism of the LPH 14 in the image forming apparatus 1 will be described.
FIG. 5 is a perspective view showing a state in which the photoconductor module PM including the photoconductor drum 12 and the exposure module EM including the LPH 14 and the advance / retreat mechanism 17 are attached to the image forming apparatus 1. In FIG. 5, the left side of the drawing is the front side of the image forming apparatus 1 and the side on which the photosensitive module PM is attached and detached, and the right side of the drawing is the rear side of the image forming apparatus 1 and image forming is performed. This is the side where the drive from a drive motor (not shown) attached to the apparatus 1 is transmitted to the photosensitive drum 12 and the like. FIG. 5 shows a state where the LPH 14 constituting the exposure module EM is set at the exposure position described above. 6 is an enlarged view of the front side in FIG. 5, and FIG. 7 is an enlarged view of the rear side in FIG.

  FIG. 8 is a perspective view showing the configuration of the photoreceptor module PM. In FIG. 8, the lower left side of the drawing corresponds to the front side of the image forming apparatus 1, and the upper right side of the drawing corresponds to the rear side of the image forming apparatus 1.

  Further, FIG. 9 is a perspective view showing the configuration of the exposure module EM, FIG. 10 is a perspective view showing the configuration of the LPH 14 in the exposure module EM, and FIG. 11 is the configuration of the advance / retreat mechanism 17 in the exposure module EM. Furthermore, FIG. 12 is a view for explaining a front regulating member 178F (described later) provided in the advance / retreat mechanism 17.

  In FIG. 9, the lower right side of the drawing corresponds to the front side of the image forming apparatus 1, and the upper left side of the drawing corresponds to the rear side of the image forming apparatus 1. In FIG. 10, the lower right side of the drawing corresponds to the front side of the image forming apparatus 1, and the upper left side of the drawing corresponds to the rear side of the image forming apparatus 1. Further, in FIG. 11, the upper right side of the drawing corresponds to the front side of the image forming apparatus 1, and the lower left side of the drawing corresponds to the rear side of the image forming apparatus 1. In FIG. 12, the left side of the drawing corresponds to the front side of the image forming apparatus 1, and the right side of the drawing corresponds to the rear side of the image forming apparatus 1.

  FIG. 13 is a perspective view showing a configuration of an elevating member 306 (described later) provided in the advance / retreat mechanism 17, and FIG. 14 is a front view of the elevating member 306. Further, FIG. 15 is a perspective view showing a configuration of a cam 305 (front cam 305F, rear cam 305R: described later) provided in the advance / retreat mechanism 17.

  In FIG. 13, the upper left side of the drawing corresponds to the front side of the image forming apparatus 1, and the lower right side of the drawing corresponds to the rear side of the image forming apparatus 1. In FIG. 14, the left side of the drawing corresponds to the front side of the image forming apparatus 1, and the right side of the drawing corresponds to the rear side of the image forming apparatus 1. Further, in FIG. 15, the left side of the drawing corresponds to the front side of the image forming apparatus 1, and the right side of the drawing corresponds to the rear side of the image forming apparatus 1.

  16A is a top view of the advance / retreat mechanism 17 viewed from the Z direction, FIG. 16B is a side view of the advance / retreat mechanism 17 viewed from the Y direction, and FIG. 16C is an A- It is A sectional drawing. Further, FIG. 17 is a perspective view showing a main part of a link mechanism 173 (described later) in the advance / retreat mechanism 17. FIG. 18 is a perspective view showing a positional relationship among the elevating member 306, the front cam 305F, and the front coil spring 304F (described later) in the advance / retreat mechanism 17. However, FIG. 18 shows the positional relationship when the advance / retreat mechanism 17 is set to the exposure position.

  In FIG. 16, the right side of the drawing corresponds to the front side of the image forming apparatus 1, and the left side of the drawing corresponds to the rear side of the image forming apparatus 1. In FIG. 17, the lower left side of the drawing corresponds to the front side of the image forming apparatus 1, and the upper right side of the drawing corresponds to the rear side of the image forming apparatus 1. Further, in FIG. 18, the upper left side of the drawing corresponds to the front side of the image forming apparatus 1, and the lower right side of the drawing corresponds to the rear side of the image forming apparatus 1.

  In the following description, the optical axis direction of the rod lens array 64 in the LPH 14 shown in FIG. 5 is referred to as a Z direction (corresponding to the first direction). The main scanning direction, that is, the axial direction of the photosensitive drum 12 is referred to as an X direction (corresponding to the second direction). Further, a sub-scanning direction, that is, a direction orthogonal to both the X direction and the Z direction is referred to as a Y direction (corresponding to a third direction).

First, the configuration of the photoconductor module PM will be described with reference to FIGS.
The photoconductor module PM as an example of the image holding module further includes a front housing 81F and a rear housing 81R for holding these in addition to the above-described photoconductor drum 12, the charger 13, and the cleaner 16. The front housing 81F and the rear housing 81R are integrated with a connection housing 81M that extends along the X direction and covers the charger 13 and the cleaner 16 (both not shown).

  In the photoreceptor module PM, a plate 82 is attached to the front side of the front housing 81F, and a cover 83 having a handle used for attaching / detaching the photoreceptor module PM is attached to the front side of the plate 82. ing. A front positioning member 84 used for positioning the LPH 14 in the Y direction is attached below the rear side of the plate 82. The plate 82 has a plurality of perforations. A part of the plurality of perforations provided in the plate 82 is a frame (not shown) on the front side of the image forming apparatus 1 when the photoreceptor module PM is inserted and attached from the front side of the image forming apparatus 1. ), The front side positioning of the photosensitive module PM with respect to the image forming apparatus 1 is performed.

  On the other hand, on the rear side of the photoreceptor module PM, a driven portion for receiving a driving force from the image forming apparatus 1 is formed on the photoreceptor drum 12, the charger 13, the cleaner 16, and the like. This driven portion is composed of a coupling member or the like, and is provided on the rear side of the image forming apparatus 1 when the photoreceptor module PM is inserted and attached from the front side of the image forming apparatus 1. It is inserted into the coupling member of the drive unit. A ring-shaped member 85 is attached to the rear side of the rear housing 81R on the rear side of the photoreceptor module PM. The ring-shaped member 85 is fitted into a rear frame (not shown) of the image forming apparatus 1 when the photoreceptor module PM is inserted and attached from the front side of the image forming apparatus 1. The rear side positioning of the photoreceptor module PM with respect to the image forming apparatus 1 is performed.

  In the photoconductor module PM, cylindrical front flanges 121F and rear flanges 121R are press-fitted to both ends of the photoconductor drum 12 in the X direction, and the front flange 121F and the rear flange 121R are respectively covered with a cover 83. The ring-shaped member 85 is rotatably supported. The front flanges 121F and 121R are respectively provided with a front ball bearing (hereinafter referred to as a front BB) 122F and a rear ball bearing (hereinafter referred to as a rear BB) 122R as an example of a support member.

  In the present embodiment, the front BB 122F is attached to the front flange 121F with a slight gap, and the rear BB 122R is attached to the rear flange 121R with a slight gap. On the other hand, the front BB 122F and the rear BB 122R are attached in close contact with the front housing 81F and the rear housing 81R, respectively. Accordingly, the front BB 122F is fixed to the front housing 81F, and the rear housing 122R is fixed to the rear housing 81R.

  Here, the front BB 122F is accommodated in the front housing 81F, and an opening is formed at a position facing the developing device 15 (see FIG. 1) and a position facing the LPH. On the other hand, the rear BB 122R is accommodated in the rear housing 81R, and openings are formed at positions facing the developing device 15 (see FIG. 1) and positions facing the LPH 14 like the front housing 81F. Therefore, the outer peripheral surfaces of the front BB 122F and the rear BB 122R are exposed at positions facing the LPH 14 and the developing unit 15. In this embodiment, the front BB 122F and the rear BB 122R are used for positioning in the Z direction of the LPH 14 to be described later. Further, the front BB 122F and the rear BB 122R are also used for positioning the developing roll constituting the developing device 14 (see FIG. 1).

Next, the configuration of the exposure module EM will be described with reference to FIGS. 5 to 7 and FIGS. 9 to 18.
The exposure module EM includes the LPH 14 and the advance / retreat mechanism 17 as described above, and the rear side of the advance / retreat mechanism 17 is held by a rear holding member 1R attached to a rear frame (not shown) of the image forming apparatus 1. Thus, the rear side positioning of the advance / retreat mechanism 17 with respect to the image forming apparatus 1 is performed. A fixing plate 176 having a plurality of perforations is attached to the lower part on the front side of the advance / retreat mechanism 17. A part of the plurality of perforations provided in the fixing plate 176 is attached by inserting the exposure module EM from the front side of the image forming apparatus 1, and then the front side frame (not shown) of the image forming apparatus 1. 2), the front side positioning of the advance / retreat mechanism 17 with respect to the image forming apparatus 1 is performed. The exposure module EM is configured such that the LPH 14 is moved between the exposure position and the retracted position by the advance / retreat mechanism 17 in a state where the advance / retreat mechanism 17 is fixed to the image forming apparatus 1 in this manner. ing. When the LPH 14 moves from the retracted position to the exposure position, the LPH 14 is positioned in the Z direction with respect to the photosensitive drum 12.

Next, the configuration of the LPH 14 will be described mainly with reference to FIG.
On the front side of the housing 61 of the LPH 14, a first front positioning pin 611F that determines the position in the Z direction on the front side of the LPH 14, and a second front positioning pin 612F that determines the position in the X direction and Y direction on the front side of the LPH 14 Is attached. On the other hand, on the rear side of the housing 61 of the LPH 14, a first rear positioning pin 611R that determines the position in the Z direction on the rear side of the LPH 14, and a second rear positioning pin that determines the positions in the X direction and Y direction on the rear side of the LPH 14 612R is attached.

  Here, the first front positioning pin 611F, the first rear positioning pin 611R, the second front positioning pin 612F, and the second rear positioning pin 612R are each configured by a cylindrical metal rod. Among these, the first front positioning pin 611F and the first rear positioning pin 611R are provided on the opposite side (Z direction) and the opposite side (−Z direction) from the housing 61 extending in the X direction to the photosensitive module PM. It is formed to project toward. Further, the tip portions of the first front positioning pins 611F and the first rear positioning pins 611R have a hemispherical shape. On the other hand, the second front positioning pin 612F and the second rear positioning pin 612R are also formed so as to protrude from the housing 61 toward both the side facing the photoconductor module PM (Z direction) and the opposite side (−Z direction). Yes. However, both ends of the second front positioning pins 612F and the second rear positioning pins 612R have a planar shape.

  Further, each of the first front positioning pins 611F, the first rear positioning pins 611R, the second front positioning pins 612F, and the second rear positioning pins 612R has an array of LED chips (CHIP1 to CHIP58: see FIG. 3). It arrange | positions in the site | part which becomes above the arrangement line of the rod lens array 64 arranged along the direction. The first front positioning pin 611F and the first rear positioning pin 611R are disposed closer to the rod lens array 64 than the second front positioning pin 612F and the second rear positioning pin 612R.

  Here, a slide member 67 used for cleaning the rod lens array 64 is attached to the LPH 14. The slide member 67 is a long member provided so as to move along the X direction (longitudinal direction of the LPH 14). Further, the slide member 67 is provided on the rear side, and supports a blade 67 (not shown) that contacts the light irradiation surface of the rod lens array 64 and cleans the light irradiation surface along with the slide. And a handle 67b which is provided on the side and receives an advance / retreat operation during cleaning. The blade is made of an elastic material such as urethane rubber. Further, the support portion 67 a is disposed across from the one side surface of the holder 65 to the other side surface. A guide (not shown) is attached to the inner side of the guide groove 65a (see FIG. 2). A slide holding member 68 is mounted on the front side of the LPH 14 to support the slide member 67 slidably with respect to the housing 61. As described above, as a result of the slide member 67 being slidable along the X direction, the support portion 67a is also slidably provided along the X direction. Therefore, when the slide member 67 is slid in the X direction using the handle 67b, the blades move while contacting the upper surface of the rod lens array 64, thereby removing dust or the like attached to the upper surface of the rod lens array 64. Will be. For example, when performing an image forming operation, the slide member 67 is disposed on the rearmost side of the LPH 14. At this position, the support portion 67 a and the blade attached to the support portion 67 a do not cover the rod lens array 64.

Next, a detailed configuration of the advance / retreat mechanism 17 will be described mainly with reference to FIGS.
The advancing / retracting mechanism 17 includes a casing 171 extending in the X direction and having a concave cross section in the YZ plane, and a lever that is attached to the front side of the casing 171 and rotates in the C direction and the D direction about the axis. 172 and a link mechanism 173 that is attached to the inside of the housing 171 and moves the holding portion 173a and the support portion 173b up and down in the Z direction relative to the housing 171 in conjunction with the operation of the lever 172. Here, the holding portion 173a and the support portion 173b are provided on the elevating member 306 shown in FIG. 13, and the link mechanism 173 is configured to elevate the elevating member 306.

  In the present embodiment, a held portion (not shown) formed by surrounding the end surface on the −Z direction side of the housing 61 of the LPH 14 on the holding portion 173 a provided on both ends in the X direction of the link mechanism 173. By holding it, the exposure module EM in which the LPH 14 and the advance / retreat mechanism 17 are integrated is configured. Further, the lower portions of the first front positioning pins 611F and the first rear positioning pins 611R (see FIG. 10) provided on the housing 61 of the LPH 14 are supported by the support portions 173b provided on both ends in the X direction of the link mechanism 173. is doing. In the advancing / retracting mechanism 17, the holding portion 173a and the support portion 173b move in the Z direction when the lever 172 is tilted in the arrow C direction, and the holding portion 173a and the support portion 173b when the lever 172 is tilted in the arrow D direction. Moves in the -Z direction.

  Therefore, in the exposure module EM, when the lever 172 of the advance / retreat mechanism 17 is tilted in the direction of arrow C, the first front positioning pin 611F and the first rear positioning pin 611R are pushed out in the Z direction by the support portion 173b. When the lever 172 is tilted in the direction of the arrow D when the lever 172 is moved in the direction of rising (exposure position), the held portion (not shown) is pulled in the −Z direction by the holding portion 173a, and the LPH 14 is lowered. Move in the direction (retracted position).

  Further, one side of the rear side of the housing 171 constituting the advance / retreat mechanism 17 is electrically connected to a harness 73 (see FIG. 3) provided on the LPH 14 when the LPH 14 is attached to the advance / retreat mechanism 17. A relay board 174 is attached. When the exposure module EM including the advance / retreat mechanism 17 is attached to the image forming apparatus 1 on the rear side of the relay board 174, a power supply connector (not shown) provided on the relay board 174 and the image forming apparatus 1 is provided. A power receiving connector 175 for connecting is attached. Further, a fixing plate 176 having a plurality of perforations is attached to the lower part of the bottom surface on the front side of the housing 171 constituting the advance / retreat mechanism 17. On the other hand, a fitting member 177 used for attachment to the rear holding member 1R (see FIG. 5) is formed on the rear side of the housing 171 constituting the advance / retreat mechanism 17 so as to protrude in the X direction.

  As shown in FIG. 12, a front regulating member 178 </ b> F is attached to the front side on the upper side of the housing 171 constituting the advance / retreat mechanism 17. FIG. 11 shows a state where the front restricting member 178F is removed from the housing 171. The front restricting member 178F is formed with a U-shaped groove extending along the Y direction. The diameter of the U-shaped groove in the X direction is set to be slightly larger than the diameter of the second front positioning pin 612F provided in the LPH 14. Therefore, when the LPH 14 is mounted on the advance / retreat mechanism 17 to configure the exposure module EM, the lower side of the second front positioning pin 612F is inserted into the U-shaped groove of the front regulating member 178F. By providing such a front restricting member 178F, the second front positioning pin 612F is not restricted for movement in the Y direction and the Z direction, but is restricted for movement in the X direction.

Next, the configuration of the elevating member 306 provided in the advance / retreat mechanism 17 will be described with reference mainly to FIGS. 13 and 14.
The elevating member 306 as an example of the support member or the mounting member is formed by punching and bending a metal plate, for example, and is formed extending in the X direction. In addition, a holding portion 173a and a support portion 173b are provided independently on the front side upper portion of the elevating member 306, respectively. On the other hand, a holding portion 173 a and a support portion 173 b are integrally provided on the rear upper portion of the elevating member 306.

Further, a front pin 306 Fa that protrudes in the Y direction is attached to the X direction side (rear side) of the support member 173 b on the front side of the elevating member 306. Further, a front long hole 306Fb extending in the Z direction and inclined in the X direction is formed on the front side of the elevating member 306 on the X direction side (rear side) with respect to the front pin 306Fa. Here, the front pin 306Fa is attached to the front elongated hole 306Fb adjacent to the rear side at a position that is approximately the center of the length in the Z direction.
Further, on the front side of the elevating member 306, on the rear side of the front long hole 306Fb, a front protruding portion 306Fc that protrudes in the −Y direction is formed by bending.

On the other hand, a rear pin 306Ra that protrudes in the Y direction is attached to the −X direction side (front side) of the support member 173b on the rear side of the elevating member 306 in the same manner as the front pin 306Fa. A rear elongated hole 306Rb extending in the Z direction and inclined in the X direction is formed on the rear side of the elevating member 306 on the X direction side (rear side) with respect to the rear pin 306Ra. Here, the rear pin 306Ra is attached to the rear elongated hole 306Rb adjacent to the rear side at a position approximately at the center of the height in the Z direction.
Further, on the rear side of the elevating member 306, a rear protrusion 306Rc protruding in the −Y direction is formed on the rear side of the rear elongated hole 306Rb.
In the present embodiment, the front long hole 306Fb and the rear long hole 306Rb provided in the elevating member 306 each have a shape extending linearly. Here, the linear shape means that the longitudinal direction of the hole provided in the elevating member 306 extends in one direction (in this example, the direction inclined in the X direction toward the Z direction).

  Next, the configuration of the link mechanism 173 provided in the advance / retreat mechanism 17 will be described mainly with reference to FIGS. 15 to 18.

  The link mechanism 173 includes a first link member 301, a second link member 302, a center coil spring 303, a front coil spring 304F, a rear coil spring 304R, a front cam 305F, a rear cam 305R, and an elevating member 306. In FIG. 16, the front restricting member 172F is not shown, and in FIG. 17, the lifting member 306 is not shown.

  Here, a cam 305 used for a front cam 305F and a rear cam 305R as an example of a rotating body includes a shaft opening 3051 formed through the main body in the Y direction, and a −X direction side of the shaft opening 3051. On the (front side), a pin opening 3052 formed penetrating in the Y direction with respect to the main body, and penetrating in the Y direction with respect to the main body on the −Z direction side (lower side) of the shaft opening 3051 A projection opening 3053 to be formed, and a spring opening 3054 formed through the body in the Y direction on the −X direction side (front side) and the −Z direction side (lower side) with respect to the shaft opening 3051. It has.

  Further, a shaft 172a extending in the Y direction and the −Y direction is rotatably inserted into the lever 172, and the lever 172 is attached to the front side of the housing 171 via the shaft 172a. Further, a shaft 172b extending in the Y direction is rotatably inserted into the lever 172, and this shaft 172b is attached to the front end portion of the first link member 301 extending in the X direction. Furthermore, a shaft 301a extending in the Y direction is formed at the rear end of the first link member 301, and this shaft 301a is rotatable to the front end of the second link member 302 extending in the X direction. Attached to. The cross section of the second link member 302 in the YZ plane is L-shaped.

  A first front long hole 302Fa and a second front long hole 302Fb that are long in the X direction are formed on the side surface of the second link member 302 on the front side. Here, the first front long hole 302Fa is formed closer to the Z direction (upper side) than the second front long hole 302Fb. In addition, a first rear long hole 302Ra and a second rear long hole 302Rb that are long in the X direction are also formed on the rear side surface of the second link member 302. Here, the second rear elongated hole 302Ra is formed closer to the Z direction (upper side) than the second rear elongated hole 302Rb.

  The center coil spring 303 is provided along the X direction at the center in the X direction of the housing 171, and the front side hook is connected to the second link member 302 and the rear side hook is connected to the housing 171. , Each is attached.

  Further, the front coil spring 304F and the front cam 305F are attached to the front side of the second link member 302, and the rear coil spring 304R and the rear cam 305R are attached to the rear side of the second link member 302, respectively.

Among these, the front coil spring 304F is provided along the X direction on the front side of the casing 171. The front hook is for the casing 171 and the rear hook is for the spring of the front cam 305F. Respectively attached to the openings 3054.
On the other hand, the rear coil spring 304R is provided on the front side of the casing 171 along the X direction, and the front hook is on the casing 171 and the rear hook is on the spring opening 3054 of the rear cam 305R. , Each is attached.

  The front cam 305F includes a front shaft 305Fa that extends in the Y direction and is attached to the shaft opening 3051 of the front cam 305F. The front shaft 305Fa is formed to project from both the Y direction side and the −Y direction side of the front cam 305F. The Y direction side of the front shaft 305Fa is attached to the wall surface on the Y direction end side of the housing 171 through the first front long hole 302Fa provided in the second link member 302. On the other hand, the −Y direction side of the front shaft 305 </ b> Fa is attached to the wall surface on the −Y direction end side of the housing 171 through a front long hole 306 </ b> Fb provided in the elevating member 306. Here, the front shaft 305Fa is inserted into a shaft opening 3051 of the front cam 305F and a shaft opening (not shown) provided on each wall surface of the housing 171. Further, both ends of the front shaft 305Fa are attached to the respective wall surfaces of the housing 171 so as to be allowed to rotate. As a result, the front cam 305F can rotate with respect to the housing 171 about the front shaft 305Fa. In the present embodiment, the front cam 305F and the front shaft 305Fa constitute a rotating member or a moving member. In the present embodiment, the front shaft 305Fa attached to the front cam 305F and the front long hole 306Fb provided in the elevating member 306 constitute a guide means.

  Further, a front pin 306Fa provided on the elevating member 306 is inserted into a pin opening 3052 provided on the front cam 305F. Here, the pin opening 3052 has a slightly larger inner diameter than the front pin 306Fa, and the front pin 306Fa is attached to the pin opening 3052 of the front cam 305 with a gap.

Furthermore, a front projection 305Fb that projects from the front cam 305F to the Y direction side is attached to the projection opening 3053 provided in the front cam 305F. And this front protrusion part 305Fb is via the 2nd front long hole 302Fb provided in the 2nd link member 302, and the long hole (not shown) formed in the wall surface of the Y direction edge part side of the housing | casing 171. The housing 171 protrudes to the outside in the Y direction. Here, the long hole formed in the wall surface on the Y direction end side of the housing 171 has an arc shape centering on the mounting position of the front shaft 305 Fa in the housing 171.
A hook on the rear side of the front coil spring 304F is attached to the spring opening 3054 provided in the front cam 305F as described above.

  Next, the rear cam 305R includes a rear shaft 305Ra extending in the Y direction and attached to the shaft opening 3051 of the rear cam 305R. The rear shaft 305Ra is formed so as to protrude from both the Y direction side and the −Y direction side of the rear cam 305R. The Y direction side of the rear shaft 305Ra is attached to the side surface on the Y direction end portion side of the housing 171 through the first rear elongated hole 302Ra provided in the second link member 302. On the other hand, the −Y direction side of the rear shaft 305 </ b> Ra is attached to the wall surface on the −Y direction end side of the housing 171 through a rear elongated hole 306 </ b> Rb provided in the elevating member 306. Here, the rear shaft 305R is inserted into a shaft opening 3051 of the rear cam 305R and a shaft opening (not shown) provided on each wall surface of the housing 171. Further, both ends of the rear shaft 305Ra are attached to the respective wall surfaces of the housing 171 so as to be allowed to rotate. As a result, the rear cam 305R can rotate about the rear shaft 305Ra with respect to the housing 171. In the present embodiment, the rear cam 305R and the rear shaft 305Ra constitute a rotating member or a moving member. In the present embodiment, the guide means is constituted by the rear shaft 305Ra attached to the rear cam 305R and the rear elongated hole 306Rb provided in the elevating member 306.

  A rear pin 306F provided on the elevating member 306 is inserted into the pin opening 3052 provided on the rear cam 305R. Here, the pin opening 3052 has an inner diameter slightly larger than the rear pin 306Ra, and the rear pin 306Ra is attached to the pin opening 3052 of the rear cam 305R with a gap.

Furthermore, a rear projection 305Rb projecting from the rear cam 305R in the Y direction side is attached to the projection opening 3053 provided in the rear cam 305R. The rear protrusion 305Rb is connected to a second rear long hole 302Rb provided in the second link member 302 and a long hole (not shown) formed in the wall surface on the Y direction end side of the housing 171. The housing 171 protrudes to the outside in the Y direction. Here, the long hole formed in the wall surface on the Y direction end side of the housing 171 has an arc shape centering on the mounting position of the rear shaft 205Ra in the housing 171.
A hook on the rear side of the rear coil spring 304R is attached to the spring opening 3052 provided in the rear cam 305R as described above.

  Note that a front leaf spring and a rear leaf spring (both not shown) each having a bent portion formed on the −Y direction side are attached to the front side and the rear side of the elevating member 306. These front leaf springs and rear leaf springs, together with the front protrusions 306Fc and the rear protrusions 306Rc formed on the elevating member 306, are used to regulate the position of the elevating member 306 in the Y direction with respect to the housing 171.

  FIG. 19 is a perspective view showing the configuration of the front positioning member 84 attached to the plate 82 (see FIG. 6) of the photoreceptor module PM. The front positioning member 84 includes a bracket 841 having a U-shaped receiving groove 841a that opens in the X direction on the lower side, and a plate spring 842 that is screwed to the bracket 841. The screw is also used for attaching the front positioning member 84 to the plate 82. Here, the upper side of the second front positioning pin 612F provided on the LPH 14 is inserted into the receiving groove 841a of the bracket 841 when the photoreceptor module PM is attached to the image forming apparatus 1. (See FIG. 6). The leaf spring 842 presses the second front positioning pin 612F in the Y direction when the second front positioning pin 612F is inserted into the receiving groove 841a of the bracket 841.

  On the other hand, FIG. 20 is a perspective view showing the configuration of the rear holding member 1R attached to the rear frame of the image forming apparatus 1. The rear holding member 1R includes a bracket 91, a first metal leaf spring 92 attached to the lower front side of the bracket 91, and a bowl-like shape attached to the upper side of the bracket 91 so as to be swingable in the Y direction. The arm 93, a metal second leaf spring 94 attached to the bracket 91 and disposed in contact with the arm 93, and the first leaf spring 92, the arm 93, and the second leaf spring 94 are fixed to the bracket 91. And a screw 95. A sliding member 94 a made of resin or the like is attached to the free end side of the second leaf spring 94. Here, when the exposure module EM is attached to the image forming apparatus 1 between the bracket 91 and the first leaf spring 92, a fitting member 177 provided on the rear side of the housing 171 of the advance / retreat mechanism 17. (See FIG. 11) is inserted. Further, the upper side of the second rear positioning pin 612R (see FIG. 10) of the LPH 14 is fitted between the bracket 91 and the arm 93 when the exposure module EM is attached to the image forming apparatus 1. The second leaf spring 94 presses the second rear positioning pin 612R in the Y direction when the second rear positioning pin 612R is caught between the bracket 91 and the arm 93. Then, the sliding member 94a provided on the second leaf spring 94 has a second rear positioning when the LPH 14 moves between the retracted position and the exposure position in a state where the second rear positioning pin 612R is inserted. The frictional force generated between the pin 612R and the arm 93 is reduced.

  Further, below the bracket 91, a housing guide portion 91a is formed that is inclined in the Y direction and the Z direction and guides the fitting member 177 when the exposure module PM is inserted. Further, below the bracket 91, a substrate holding portion 91b that holds a relay substrate 174 (see FIG. 9) attached to the advance / retreat mechanism 17 when the exposure module PM is inserted is formed. An inclined surface in the Z direction is also formed on the front side of the substrate holding portion 91b so as to guide the relay substrate 174 to be inserted.

  Now, a procedure for mounting the exposure module EM to the image forming apparatus 1 and a procedure for mounting the photosensitive module PM to the image forming apparatus 1 to which the exposure module EM is attached will be described with reference to FIGS.

  First, the exposure module EM is inserted from the front side of the image forming apparatus 1 into the image forming apparatus 1 to which the exposure module EM and the photoreceptor module PM are not attached. At this time, the lever 172 of the advance / retreat mechanism 17 constituting the exposure module EM is almost horizontal with the housing 171 by being tilted in the D direction in FIG. 9, and the LPH 14 is drawn into the advance / retreat mechanism 17 side. Yes. The inserted exposure module EM advances from the front side (one end side) toward the rear side (the other end side) along a guide (not shown) provided in the image forming apparatus 1.

  Thereafter, with the insertion, the rear side of the exposure module EM is fitted into the rear holding member 1 </ b> R provided on the rear side frame of the image forming apparatus 1. More specifically, a fitting member 177 provided on the rear side of the advance / retreat mechanism 17 is sandwiched between the bracket 91 of the rear holding member 1R and the first leaf spring 92, and advances / retreats with respect to the image forming apparatus 1. The rear side of the mechanism 17 is fixed. Also, a second rear positioning pin 612R provided on the rear side of the LPH 14 is sandwiched between the bracket 91 and the arm 93 of the rear holding member 1R, and the arm 93 is pushed in the Y direction by the second leaf spring 94. As a result, the position in the Y direction on the rear side of the LPH 14 is determined. Further, a power receiving connector 175 provided on the rear side of the advance / retreat mechanism 17 is fitted into a power supply connector (not shown) provided on the rear side of the image forming apparatus 1, and both are electrically connected. On the other hand, the fixing plate 176 provided on the front side of the advance / retreat mechanism 17 and the front side frame (not shown) of the image forming apparatus 1 face each other, and the fixing plate 176 is screwed to the front side frame. Is done. Thus, the rear side of the advance / retreat mechanism 17 is fixed to the rear holding member 1R provided on the rear frame of the image forming apparatus 1, and the front side is fixed to the front side frame of the image forming apparatus 1, thereby forming an image. The advance / retreat mechanism 17 is positioned with respect to the device 1. Further, since the front regulating member 178F provided in the advance / retreat mechanism 17 fixed to the image forming apparatus 1 regulates the movement of the LPH 14 in the X direction via the second front positioning pin 612F, Directional positioning is made.

  Next, the photoreceptor module PM is inserted from the front side of the image forming apparatus 1 into the image forming apparatus 1 to which the exposure module EM is thus attached. At this time, the lever 172 of the advance / retreat mechanism 17 constituting the exposure module EM remains tilted in the D direction, and the LPH 14 is maintained in a state of being pulled to the advance / retreat mechanism 17 side. At this time, since the lever 172 is tilted in the D direction, the lever 172 does not interfere with the insertion of the photoreceptor module PM. The inserted photoreceptor module PM advances from the front side to the rear side along a guide (not shown) provided in the image forming apparatus 1.

  Thereafter, a ring-shaped member 85 provided on the rear side of the photoconductor module PM is inserted into a rear frame (not shown) of the image forming apparatus 1 along with the insertion, and also on the front side of the photoconductor module PM. A front pin 1 </ b> F provided on a front frame (not shown) of the image forming apparatus 1 is fitted into a hole of the provided plate 82. Further, a driven part (coupling member) provided on the rear side of the photoreceptor module PM is fitted into a driving part (coupling member) provided on the rear side of the image forming apparatus 1. In this way, the rear side of the photoconductor module PM is fixed to the rear frame of the image forming apparatus 1, and the front side is fixed to the front pin 1F provided on the front side frame of the image forming apparatus 1, thereby forming an image. The photoreceptor module PM is positioned with respect to the apparatus 1.

  Further, with the insertion of the photoreceptor module PM, the second front positioning pin 612F provided on the front side of the LPH 14 is sandwiched in the receiving groove 841a of the front positioning member 84 provided on the front side of the photoreceptor module PM. When the second front positioning pin 612F is pushed in the Y direction by the leaf spring 842, the position in the Y direction on the front side of the LPH 14 is determined. On the rear side of the image forming apparatus 1, the rear holding member 1R has already determined the Y-direction position of the LPH 14 on the rear side via the second rear positioning pin 612R. As described above, the rear holding member 1R provided on the rear frame of the image forming apparatus 1 restricts the movement of the second rear positioning pin 612R of the LPH 14 in the Y direction, and is applied to the plate 82 of the photoreceptor module PM. Since the attached front positioning member 84 restricts the movement of the second front positioning pin 612F of the LPH 14 in the Y direction, the LPH 14 is positioned in the Y direction.

  After the photoreceptor module PM is set in the image forming apparatus 1, the lever 172 of the advance / retreat mechanism 17 of the exposure module EM is pulled up in the C direction, and the lever 172 is substantially perpendicular to the housing 171. The image forming apparatus 1 is fixed by a fixing member (not shown) provided in the image forming apparatus 1. Then, the link mechanism 173 operates in conjunction with the lifting of the lever 172, and the holding portion 173a and the support portion 173b rise in the Z direction. Further, when the holding portion 173a and the support portion 173b rise in the Z direction, the LPH 14 supported by the support portion 173b is lifted in the Z direction. At this time, the lower side of the second front positioning pin 612F provided on the front side of the LPH 14 is restricted from moving in the X direction by the front restricting member 178F attached to the housing 171 of the advance / retreat mechanism 17. Further, the upper side of the second front positioning pin 612F is attached to the frame on the rear side of the image forming apparatus 1 by the front positioning member 84 attached to the photoreceptor module PM. The rear holding member 1 </ b> R is restricted from moving in the Y direction. For this reason, the LPH 14 moves in the Z direction in a state in which movement in the X direction and the Y direction is restricted, in other words, in a state in which positioning in the X direction and the Y direction is performed. At this time, the LPH 14 is pressed by the spring force in the Y direction, but not pressed by the spring force in the X direction. For this reason, the LPH 14 is lifted in the Z direction with a small force as compared with the case where the LPH 14 is pressed by the spring force in both the X direction and the Y direction.

  When the LPH 14 is lifted in the Z direction, the first front positioning pin 611F provided on the front side of the LPH 14 hits the front BB 122F provided on the front side of the photoreceptor module PM, and is provided on the rear side of the LPH 14. Further, the first rear positioning pin 611R abuts against a rear BB122R provided on the rear side of the photoreceptor module PM. As described above, the front BB 122F and the rear BB 122R provided at both ends in the X direction of the photosensitive drum 12 of the photosensitive module PM are connected to the LPH 14 in the Z direction via the first front positioning pin 611F and the first rear positioning pin 611R. Since the movement is restricted, the LPH 14 is positioned in the Z direction.

Therefore, the LPH 14 set at the exposure position is positioned with respect to the photosensitive drum 12 as follows.
First, in the X direction, the lower side of the second front positioning pin 612F is positioned by being held by the front regulating member 178F of the advance / retreat mechanism 17 fixed to the image forming apparatus 1.
In the Y direction, the upper side of the second rear positioning pin 612R is connected to the front positioning member 84 provided on the photoconductor module PM fixed to the image forming apparatus 1, and the upper side and the lower side of the second rear positioning pin 612R are The image forming apparatus 1 is positioned by being held on the rear holding member 1R fixed to the frame on the rear side.
Further, in the Z direction, the first front positioning pins 611F and the first rear positioning pins 611R are positioned by being pressed against the front BB 122F and the rear BB 122R provided in the photosensitive member module PM fixed to the image forming apparatus 1, respectively. The

  That is, the LPH 14 is positioned relative to the photosensitive drum 12 in the X direction with reference to the advancing / retracting mechanism 17 on both the front side and the rear side, and the LPH 14 is positioned relative to the photosensitive drum 12 in the Z direction on the front side and the rear side. The module PM is used as a reference. On the other hand, the positioning of the LPH 14 in the Y direction with respect to the photosensitive drum 12 is performed with the front side as the reference and the rear side as the reference of the image forming apparatus 1.

  The removal of the photosensitive module PM and the exposure module EM from the image forming apparatus 1 is performed in reverse to the above-described procedure. That is, by releasing the lock by a fixing member (not shown) provided in the image forming apparatus 1, first, the lever 172 provided in the advance / retreat mechanism 17 is rotated in the direction D in FIG. Next, the photoreceptor module PM is pulled out from the rear side to the front side of the image forming apparatus 1. Thereafter, after removing screws and the like, the exposure module EM is pulled out from the rear side to the front side of the image forming apparatus 1.

  By the way, in the present embodiment, the LPH 14 is moved to the retracted position or the exposure position by manually operating the lever 172 provided in the advance / retreat mechanism 17 of the exposure module EM. However, the advance / retreat mechanism 17 of the present embodiment is normally configured so that the LPH 14 is placed in a standby position where the LPH 14 exists between the retracted position and the exposure position. In the standby position, the lever 172 is inclined as shown in FIGS. This is because, for example, when the LPH 14 set at the exposure position is retracted to the retracted position, a strong force is required to rotate the lever 172. Another reason is to avoid an increase in impact when releasing the pressing in the Z direction against the LPH 14 set at the exposure position.

FIG. 21 is a diagram showing the state of the advance / retreat mechanism 17 at the exposure position, the standby position, and the retracted position. 21A shows the state at the exposure position, FIG. 21B shows the state at the standby position, and FIG. 21C shows the state at the retracted position. However, in FIG. 21, the description of the elevating member 306 provided in the advance / retreat mechanism 17 is omitted.
22 is a diagram for explaining the front side state of the advance / retreat mechanism 17 when the retracted position is set, and FIG. 23 is a diagram illustrating the rear side of the advance / retract mechanism 17 when the retracted position is set. It is a figure for demonstrating a state. Further, FIG. 24 is a diagram for explaining the state of the front side of the advance / retreat mechanism 17 when the exposure position is set, and FIG. 25 is a diagram of the rear side of the advance / retreat mechanism 17 when the exposure position is set. It is a figure for demonstrating a state. However, in FIG. 22 to FIG. 25, the description of the first link member 301 and the second link member 302 is omitted.

  First, the state of the advance / retreat mechanism 17 when the standby position is set will be described with reference to FIG.

  In the advance / retreat mechanism 17, the second link member 302 is pulled in the X direction (rear side) with respect to the housing 171 by the center coil spring 303. Then, when the front protrusion 305Fb hits the front side end of the second front elongated hole 302Fb of the second link member 302, the front cam 305F tries to rotate counterclockwise in the figure around the front shaft 305Fa. The power to do is given. Further, when the rear protrusion 305Rb hits the front end of the second rear elongated hole 302Rb of the second link member 302, the rear cam 305R also tries to rotate counterclockwise in the drawing around the rear shaft 305Ra. Power is granted.

  On the other hand, the front cam 305F is pulled in the −X direction (front side) with respect to the housing 171 by the front coil spring 304F. As a result, a force is applied to the front cam 305F to rotate in the clockwise direction in the drawing around the front shaft 305Fa. The rear cam 305R is also pulled in the −X direction (front side) with respect to the housing 171 by the rear coil spring 304R. As a result, the rear cam 305R is also given a force to rotate in the clockwise direction in the drawing around the rear shaft 305Ra.

  As a result, the front cam 305F and the rear cam 305R come to rest at a position where the force of the center coil spring 303 balances the force of the front coil spring 304F and the rear coil spring 304R. At this time, in the elevating member 306 (not shown), the front pin 306Fa is pushed by the inner wall surface on the −Z direction side of the pin opening 3052 provided in the front cam 305F, and the rear pin 306Ra is provided in the rear cam 305R. The pin opening 3052 is pushed by the inner wall surface. Then, the holding portion 173a and the support portion 173b provided on the front side and the rear side of the elevating member 306 are stopped in a state set to the first height with respect to the housing 171. At this time, the Z-direction heights of the front-side holding portion 173a and the rear-side holding portion 173a are the same, and the front-side support portion 173b and the rear-side support portion 173b are in the Z-direction. The height is the same.

  At this time, the front shaft 305Fa of the front cam 305F is positioned at the approximate center of the front long hole 306Fb provided in the elevating member 306, and the first front long hole 302Fa provided in the second link member 302 Located in the approximate center. On the other hand, the rear shaft 305Ra of the rear cam 305R is also located in the approximate center of the front elongated hole 306Fb provided in the elevating member 306 and in the approximate center of the first rear elongated hole 302Rb provided in the second link member 302. To do.

As a result, at the standby position, the front shaft 305Fa of the front cam 305F and the front pin 306Fa of the elevating member 306 are stationary in a state where they are aligned along the X direction. In the standby position, the rear shaft 305Ra of the rear cam 305R and the rear pin 306Ra of the elevating member 306 are stationary in a state where they are aligned along the X direction.
In this state, the lever 172 connected to the second link member 302 via the first link member 301 is inclined (about 45 °) with respect to the X direction and the Z direction about the shaft 172a. It will be stationary.

  Next, referring to FIGS. 21A, 21B, 24 and 25, the operation of the advance / retreat mechanism 17 when the setting is changed from the standby position to the exposure position and the setting when the exposure position is set. The state of the advance / retreat mechanism 17 will be described.

  When moving the LPH 14 (not shown) from the standby position to the exposure position, the lever 172 is operated in the C direction. Then, the lever 172 rotates about the shaft 172a, and the shaft 172b provided on the lever 172 also rotates in the C direction with this rotation. Along with this, the first link member 301 attached to the shaft 172b is pulled in the −X direction (front side). When the first link member 301 is pulled to the front side, the second link member 302 connected to the first link member 302 via the shaft 301 a moves in the −X direction against the compressive force of the center coil spring 303. . Further, as the second link member 302 moves in the −X direction (front side), the first front elongated hole 302Fa, the second front elongated hole 302Fb, and the first rear elongated hole provided in the second link member 302. 302Ra and the second rear elongated hole 302Rb also move in the −X direction (front side).

  At this time, the front cam 305F is pulled in the −X direction (front side) by the front coil spring 304F, and the second link member 302 of the second link member 302 against which the front protrusion 305Fb attached to the front cam 305F is abutted. The front long hole 302Fb is moving in the −X direction (front side). For this reason, the front cam 305F rotates clockwise around the front shaft 305Fa while maintaining the state in which the front protrusion 305Fb is in contact with the front side end of the second front elongated hole 302Fb.

  On the other hand, the rear cam 305R is also pulled in the −X direction (front side) by the rear coil spring 304R, and the second rear elongated hole of the second link member 302 in which the rear protrusion 305Rb attached to the rear cam 305R is abutted. 302Rb is moving in the -X direction (front side). For this reason, the rear cam 305R rotates in the clockwise direction in the drawing around the rear shaft 305Ra while maintaining the state where the rear protrusion 305Rb abuts against the front side end of the second rear elongated hole 302Rb.

  During this time, the front cam 305F and the rear cam 305R rotate clockwise by the same angle as the second link member 302 moves in the −X direction (front side).

As the front cam 305F and the rear cam 305R rotate as described above, in the elevating member 306, the front pin 306Fa is pushed by the inner wall surface on the −Z direction side of the pin opening 3052 provided in the front cam 305F, and the rear pin 306Ra is pushed by the inner wall surface on the −Z direction side of the pin opening 3052 provided in the rear cam 305R.
Thus, since the front pin 306Fa and the rear pin 306Ra are pushed in the Z direction, the elevating member 306 to which the front pin 306Fa and the rear pin 306Ra are attached is pushed up in the Z direction.

However, during this time, the front cam 305F and the rear cam 305R rotate clockwise from the state at the standby position, so that the pin opening 3052 provided in the front cam 305F and the pin opening provided in the rear cam 305R are used. The opening 3052 moves slightly in the X direction (rear side) when moving in the Z direction.
For this reason, in the movement from the standby position to the exposure position, a force directed in the X direction (rear side) as well as a force directed in the Z direction is applied to the elevating member 306 via the front pin 306Fa and the rear pin 306Ra. Therefore, when moving from the standby position to the exposure position, the elevating member 306 tends to move slightly in the X direction (rear side) as it moves in the Z direction.

Here, in the present embodiment, a front oblong hole 306Fb provided in the elevating member 306 and penetrating the front shaft 305Fa of the front cam 305F has a shape inclined in the X direction toward the Z direction. The mounting position of the front shaft 305Fa with respect to the housing 171 is fixed.
Further, in the present embodiment, a rear elongated hole 306Rb provided in the elevating member 306 and penetrating the rear shaft 305Ra of the rear cam 305R has a shape inclined in the X direction toward the Z direction. The mounting position of the rear shaft 305Ra with respect to the housing 171 is fixed.

  Therefore, when the elevating member 306 is lifted from the housing 171 to change the setting from the standby position to the exposure position in the advance / retreat mechanism 17, the front pin 306Fa and the rear pin 306Ra become closer to the exposure position from the standby position. The angle formed between the direction of the force received by the elevating member 306 via the direction of the front elongated hole 306Fb formed in the elevating member 306 becomes smaller. Further, the angle between the direction of the force received by the elevating member 306 via the front pin 306Fa and the rear pin 306Ra and the direction of the rear elongated hole 306Rb formed in the elevating member 306 becomes smaller.

  As a result, when the advance / retreat mechanism 17 is operated so as to move from the standby position to the exposure position, the front shaft 305Fa of the front cam 305F is not easily caught by the front long hole 306Fb of the elevating member 306, particularly on the exposure position side. Further, when the advance / retreat mechanism 17 is operated so as to move from the standby position toward the exposure position, the rear shaft 305Ra of the rear cam 305R is not easily caught in the rear elongated hole 306Rb of the elevating member 306, particularly on the exposure position side.

  As a result, the elevating member 306 moves upward in the Z direction from the standby position while maintaining the state in which the holding portions 173a and the support portions 173b provided on the front side and the rear side are respectively kept horizontal. It moves to a second position farther from the housing 171 than the first position and stops. At this time, the Z-direction heights of the front-side holding portion 173a and the rear-side holding portion 173a are the same, and the front-side support portion 173b and the rear-side support portion 173 in the Z-direction. The height is the same.

  Therefore, when the exposure module EM having the advance / retreat mechanism 17 is used for positioning in the Z direction with respect to the photoreceptor module PM (positioning of the LPH 14 to the exposure position), the front side or rear side of the LPH 14 is caught and defocusing or The situation of causing density unevenness in the X direction is suppressed.

  At this time, the front shaft 305Fa of the front cam 305F is positioned on the −Z direction side (lower side) of the center of the front long hole 306Fa provided in the elevating member 306, and provided on the second link member 302. The first front elongated hole 302Fa is positioned on the X direction side (rear side). On the other hand, the rear shaft 305Ra of the rear cam 305R is also positioned on the −Z direction side (lower side) of the center of the rear elongated hole 306Ra provided in the elevating member 306, and the second shaft provided in the second link member 302. It is located on the X direction side (rear side) of the rear elongated hole 302Ra.

As a result, at the exposure position, the front pin 306Fa of the elevating member 306 is stationary with respect to the front shaft 305Fa of the front cam 305F while moving in the Z direction as compared with the standby position. Further, at the exposure position, the rear pin 306Ra of the elevating member 306 is stationary with respect to the rear shaft 305Ra of the rear cam 305R while moving in the Z direction as compared with the standby position.
In this state, the lever 172 connected to the second link member 302 via the first link member 301 is stationary while standing upright in the Z direction.

  Next, referring to FIGS. 21B, 21C, 22 and 23, the operation of the advancing / retreating mechanism 17 when the setting is changed from the standby position to the retracted position and when the retracted position is set. The state of the advance / retreat mechanism 17 will be described.

  When moving the LPH 14 from the standby position to the retracted position, the lever 172 is operated in the D direction. Then, the lever 172 rotates about the shaft 172a, and the shaft 172b provided on the lever 172 also rotates in the D direction with this rotation. Accordingly, the first link member 301 attached to the shaft 172b is pushed in the X direction (rear side). When the first link member 301 is pushed to the rear side, the second link member 302 connected to the first link member 302 via the shaft 301a is in contact with the front end of the second front long hole 302Fb. Compression force received from the front coil spring 304F via the portion 305Fb and the front cam 305F, and compression force received from the rear coil spring 304R via the rear protrusion 205Rb and the rear cam 305R contacting the front end of the second rear elongated hole 302Fb Move in the X direction against

At this time, the front cam 305F rotates counterclockwise in the drawing around the front shaft 305Fa while maintaining the state where the front protrusion 305Fb is in contact with the second front long hole 302Fb of the second link member 302.
On the other hand, the rear cam 305R also rotates counterclockwise in the drawing around the rear shaft 305Ra while maintaining the state where the rear protrusion 305Rb is in contact with the second rear elongated hole 302Rb of the second link member 302.
During this time, the front cam 305F and the rear cam 305R rotate counterclockwise by the same angle as the second link member 302 moves in the X direction (rear side).

As the front cam 305F and the rear cam 305R rotate as described above, in the elevating member 306, the front pin 306Fa is pushed by the inner wall surface on the Z direction side of the pin opening 3052 provided in the front cam 305F, and the rear pin 306Ra Is pushed by the inner wall surface on the Z direction side of the pin opening 3052 provided in the rear cam 305R.
Thus, since the front pin 306Fa and the rear pin 306Ra are pushed in the −Z direction, the elevating member 306 to which the front pin 306Fa and the rear pin 306Ra are attached is pushed down in the −Z direction.

However, during this time, the front cam 305F and the rear cam 305R rotate counterclockwise in the figure from the state at the standby position, so the pin opening 3052 provided in the front cam 305F and the pin provided in the rear cam 305R The opening 3052 moves slightly in the X direction (rear side) when moving in the −Z direction.
For this reason, in the movement from the standby position to the retracted position, a force toward the X direction (rear side) is applied to the elevating member 306 along with a force toward the −Z direction via the front pin 306Fa and the rear pin 306Fb. Therefore, in the movement from the standby position to the retracted position, the elevating member 306 tends to move slightly in the X direction (rear side) with the movement in the Z direction.

  Therefore, when the elevating member 306 is pulled into the housing 171 in order to change the setting from the standby position to the retracted position in the advance / retreat mechanism 17, the front pin 306Fa and the rear pin are moved closer to the retracted position from the standby position. The angle formed between the direction of the force received by the elevating member 306 via 306Ra and the direction of the front elongated hole 306Fb formed in the elevating member 306 increases. Further, the angle formed between the direction of the force received by the elevating member 306 via the front pin 306Fa and the rear pin 306Ra and the direction of the rear elongated hole 306Rb formed in the elevating member 306 becomes larger.

  As a result, when the advance / retreat mechanism 17 is operated so as to move from the standby position to the retracted position, the front shaft 305Fa of the front cam 305F is easily rubbed against the front long hole 306Fb of the elevating member 306 on the retracted position side. Further, when the advance / retreat mechanism 17 is operated so as to move from the standby position toward the retracted position, the rear shaft 305Ra of the rear cam 305R is easily rubbed against the rear elongated hole 306Rb of the elevating member 306, particularly on the retracted position side.

  As a result, the elevating member 306 descends in the −Z direction from the standby position while maintaining the state in which the holding portions 173a and the support portions 173b provided on the front side and the rear side, respectively, are kept horizontally. It moves to a third position closer to the housing 171 than the first position and stops. At this time, the Z-direction heights of the front-side holding portion 173a and the rear-side holding portion 173a are different due to the above-described rubbing, or the front-side support portion 173b and the rear-side support portion 173 are in the Z-direction. However, since there is no need to perform an exposure operation at the retracted position, this is not a problem.

  At this time, the front shaft 305Fa of the front cam 305F is located on the Z direction side (upper side) of the center portion of the front elongated hole 306Fa provided in the elevating member 306 and is provided on the second link member 302. The first front long hole 302Fa is positioned on the −X direction side (front side). On the other hand, the rear shaft 305Ra of the rear cam 305R is also located on the Z direction side (upper side) of the center of the rear elongated hole 306Ra provided in the elevating member 306, and the first rear length provided in the second link member 302. It is located on the −X direction side (front side) of the hole 302Ra.

As a result, in the retracted position, the front pin 306Fa of the elevating member 306 is stationary with respect to the front shaft 305Fa of the front cam 305F in a state of moving in the −Z direction as compared with the standby position. Further, at the retracted position, the rear pin 306Ra of the elevating member 306 is stationary with respect to the rear shaft 305Ra of the rear cam 305R while being moved in the −Z direction as compared with the standby position.
In this state, the lever 172 connected to the second link member 302 via the first link member 301 is stationary while lying in the −X direction.

  Here, FIG. 26 shows the direction of the force received by the elevating member 306 via the front cam 305F on the front side of the advance / retreat mechanism 17 when the advance / retreat mechanism 17 is operated from the retracted position to the exposure position. It is a figure for demonstrating the relationship with the direction to which the raising / lowering member 306 moves with the received force. More specifically, FIG. 26 shows the direction F of the force applied to the front pin 306Fa of the elevating member 306 through the pin opening 3052 of the front cam 305F and the front elongated hole 306Fb provided in the elevating member 306. A relationship with the direction D in which the elevating member 306 whose movement is restricted by insertion of the front shaft 305Fa of the cam 305F is shown. FIG. 26A shows the state at the retracted position, and FIG. 26B shows the state at the exposure position.

  FIG. 27 shows the direction of the force received by the elevating member 306 via the rear cam 305R on the rear side of the advance / retreat mechanism 17 when the advance / retreat mechanism 17 is operated from the retracted position to the exposure position. It is a figure for demonstrating the relationship with the direction to which the raising / lowering member 306 moves with force. More specifically, FIG. 27 shows the direction F of the force applied to the rear pin 306Ra of the elevating member 306 through the pin opening 3052 of the rear cam 305R, and the rear long hole 306Rb provided in the elevating member 306. A relationship with the moving direction D of the elevating member 306 whose movement is restricted by inserting the rear shaft 305Ra is shown.

  Now, consider a case where the elevating member 306 is to be lifted from the state (retracted position) shown in FIGS. 26 (a) and 27 (a).

  First, as shown in FIG. 26A, on the front side of the advance / retreat mechanism 17, the front cam 305F rotates in the clockwise direction in the drawing. At this time, a force is applied to the front pin 306Fa inserted into the pin opening 3052 of the front cam 305F in a direction F indicated by a broken line arrow in the figure. On the other hand, the front shaft 305Fa of the front cam 305F passes through the front elongated hole 306Fb of the elevating member 306 to which the front pin 306Fa is attached, and the position of the front shaft 305Fa is fixed to the housing 171. Therefore, the elevating member 306 tries to move in the direction D indicated by the broken-line arrow in the drawing.

  As shown in FIG. 27A, on the rear side of the advance / retreat mechanism 17, the rear cam 305R rotates in the clockwise direction in the drawing. At this time, force is applied to the rear pin 306Ra inserted into the pin opening 3052 of the rear cam 305R in the direction F indicated by a broken line in the drawing. On the other hand, the rear shaft 305Ra of the rear cam 305R passes through the rear elongated hole 306Rb of the elevating member 306 to which the rear pin 306Ra is attached, and the position of the rear shaft 305Ra is fixed to the housing 171. Since it is attached in a state, the elevating member 306 tries to move in a direction D indicated by a broken-line arrow in the drawing.

As described above, in the state shown in FIGS. 26A and 27A, the front cam 305F and the rear cam 305R apply a force to the elevating member 306 in the direction F including the Z direction component and the −X direction component. It will be. On the other hand, the elevating member 306 includes a Z-direction component and an X-direction component by a front elongated hole 305Fb into which the front shaft 305Fa of the front cam 305F is inserted and a rear elongated hole 305Rb into which the rear shaft 305Rb of the rear cam 305R is inserted. Try to move in direction D.
In the following description, the direction F is called a force direction, and the direction D is called a moving direction. The difference in angle between the force direction F and the moving direction D is referred to as an angle difference α.

  Next, when the elevating member 306 is lifted from the state (retracted position) shown in FIGS. 26 (a) and 27 (a) and reaches the state (exposure position) shown in FIGS. 26 (b) and 27 (b). think of.

  First, as shown in FIG. 26 (b), on the front side of the advancing / retracting mechanism 17, the pin opening 3052 provided in the front cam 305F is more than the front shaft 305Fa as the front cam 305F rotates in the clockwise direction. -Moves from the position on the Z direction side to the position on the Z direction side from the front shaft 305Fa. Accordingly, the direction F of the force applied to the front pin 306Fa inserted into the pin opening 3052 of the front cam 305F includes a Z direction component and a −X direction component (the state shown in FIG. 26A). As the −X direction component gradually decreases, the ratio of the Z direction component increases. When the front shaft 305Fa and the front pin 306Fa are aligned in the X direction at the standby position, the −X direction component disappears and the Z direction component After this, the Z-direction component and the X-direction component are now included, and the X-direction component increases with rotation.

  Further, as shown in FIG. 27 (b), on the rear side of the advance / retreat mechanism 17, the pin opening 3052 provided in the rear cam 305R is more −Z than the rear shaft 305Ra as the rear cam 305R rotates in the clockwise direction. It moves from the position on the direction side to the position on the Z direction side with respect to the rear shaft 305Ra. Accordingly, the direction F of the force applied to the rear pin 305Ra inserted into the pin opening 3052 of the rear cam 305R gradually increases from the state including the Z direction component and the −X direction component (the state shown in FIG. 27A). As the −X direction component decreases, the ratio of the Z direction component increases. When the rear shaft 305Ra and the rear pin 306Ra are aligned in the X direction at the standby position, the −X direction component disappears and only the Z direction component becomes. After that, the Z direction component and the X direction component are now included, and the X direction component increases with rotation.

  Through this process, in the present embodiment, for example, as shown in FIG. 26 (b), the force direction F is maintained with the elevating member 306 fully raised on the front side of the advance / retreat mechanism 17. And the moving direction D both include a Z direction component and an X direction component. Further, for example, as shown in FIG. 27 (b), the force direction F and the moving direction D are both in the Z direction component and the X direction in the state where the elevating member 306 is fully raised even on the rear side of the advance / retreat mechanism 17. Ingredients. In particular, in this example, the force direction F and the moving direction D are aligned on both the front side and the rear side of the advance / retreat mechanism 17.

  Further, through such a process, in the present embodiment, the elevating member 306 moves upward while being slightly inclined in the Z direction and in the X direction. Here, in the exposure module EM, while the LPH 14 is lifted by the elevating / lowering member 306 of the advance / retreat mechanism 17, via the front positioning pin 612 </ b> F inserted in the front restricting member 178 </ b> F (see FIG. 12) provided in the advance / retreat mechanism 17. The movement of the LPH 14 to which the front positioning pin 612F is attached in the X direction and the −X direction is restricted. For this reason, while the elevating member 306 is lifted in a state inclined slightly in the X direction toward the Z direction, the front positioning pin 612F provided on the LPH 14 is positioned on the rear side wall surface of the front regulating member 178F provided on the advance / retreat mechanism 17. Will be kept pressed.

  Here, FIG. 28A shows the relationship between the rotation angle θ (°) of the front cam 305F and the angle difference α between the direction F of force and the direction D of movement. Here, the rotation angle θ is assumed to be the reference (0 °) when it is in the retracted position, and the rotation angle θ increases with the clockwise rotation. Here, the description is given by taking the front cam 305F side as an example, but the same applies to the rear cam 305R side.

  In the present embodiment, by providing the above-described configuration, the angle difference α at the exposure position is made smaller than the angle difference α at the retracted position. In particular, in the present embodiment, the angle difference α at the exposure position is substantially 0 °, that is, the force direction F and the moving direction D are aligned at the exposure position. In the present embodiment, since the front elongated hole 306Fb provided in the elevating member 306 has a linear shape extending along one direction, the rotation angle θ and the angle difference α have a linear relationship. As shown.

  FIG. 28B shows an angle difference α between the force direction F and the moving direction D, and the front shaft 305Fa and the lifting member 306 provided on the front cam 305F as the lifting member 306 moves upward. It is a figure which shows the relationship with the frictional force (micro | micron | mu) F acting between the inner walls of the front long hole 306Fb. Here, the description is given by taking the front cam 305F side as an example, but the same applies to the rear cam 305R side.

  In this example, the increase in the absolute value of the angle difference α means that in the force applied to the elevating member 306 from the front cam 305F via the front pin 306Fa, the −X direction component (or the X direction) compared to the Z direction component. It means that the ratio of the component) is increasing. When the force applied to the elevating member 306 in the −X direction (or the X direction) increases as described above, when the elevating member 306 is going to rise, the front shaft 305Fa provided on the front cam 305F is moved up and down. It becomes easy to abut against the inner wall of the front oblong hole 306Fb provided in. Then, as this abutment becomes stronger, the frictional force μF acting between the front shaft 305Fa and the inner wall of the front elongated hole 306Fb increases, which may hinder the ascending operation of the elevating member 306. If the front side of the elevating member 306 stops lower than the state shown in FIG. 24 due to the hindering of the elevating operation of the elevating member 306, the LPH 14 by the advance / retreat mechanism 17 with respect to the photosensitive drum 12 is stopped. Positioning in the Z direction on the front side will be insufficient. If the same situation occurs on the rear cam 305R side, as a result, the rear side Z-direction positioning of the LPH 14 with respect to the photosensitive drum 12 by the advance / retreat mechanism 17 becomes insufficient.

In contrast, in the present embodiment, since the above-described configuration is provided, the angle difference α decreases as the exposure position is approached. Therefore, when the elevating member 306 is about to rise, it is provided, for example, on the front cam 305F. The front shaft 305Fa is less likely to abut against the inner wall of the front long hole 306Fb provided in the elevating member 306. Even when the front shaft 305Fa is in contact with the inner wall of the front elongated hole 306Fb, the frictional force μF acting between the two is reduced. On the other hand, for example, the rear shaft 305Ra provided in the rear cam 305R is also difficult to abut against the inner wall of the rear elongated hole 306Rb provided in the elevating member 306. Even when the rear shaft 305Ra is in contact with the inner wall of the rear elongated hole 306Rb, the frictional force μF acting between them is reduced.
For this reason, the raising operation of the elevating member 306 is less likely to be hindered on the exposure position side, and the LPH 14 lifted by the elevating member 306 of the advance / retreat mechanism 17 moves to a target position and stops. Therefore, the front side and rear side of the LPH 14 are positioned in the Z direction at the target exposure position.

  In the present embodiment, the force direction F and the movement direction D are aligned with the elevating member 306 of the advance / retreat mechanism 17 fully raised in the Z direction. However, the present invention is not limited to this. It is sufficient that at least the force direction F and the movement direction D are directed to the same side.

In the present embodiment, the shapes of the front long hole 306Fb and the rear long hole 306Rb provided in the elevating member 306 are linear, but the present invention is not limited to this.
FIG. 29A shows another configuration example of the front long hole 306 </ b> Fb and the rear long hole 306 </ b> Rb provided in the elevating member 306. In the example shown in FIG. 29 (a), the front long hole 306Fb and the rear long hole 306Rb are a first region extending in the Z direction and inclined in the X direction on the −Z direction side, and the Z direction side of the first region. The second region extends in the Z direction and inclines in the X direction at an angle inclined to the Z direction side relative to the first region.

  FIG. 29B shows the rotational angle θ (°) of the front cam 305F, the force direction F, and the moving direction D when the elevating member 306 having the configuration shown in FIG. This shows the relationship with the angle difference α. However, in FIG. 29B, the case where this configuration is adopted is indicated by a thick two-dot chain line, and the case where the configuration described in the first embodiment is adopted is indicated by a thin one-dot chain line. Here, the description is given by taking the front cam 305F side as an example, but the same applies to the rear cam 305R side.

  When this configuration is employed, it can be seen that the angle difference α when starting to lift the elevating member 306 from the retracted position is smaller than when the configuration described in the first embodiment is employed. When the angle difference α is small, it means that the frictional force μF generated when the elevating member 306 is lifted is small as described with reference to FIG. Therefore, when this configuration is adopted, when the lifting member 306 is lifted from the retracted position toward the standby position and the exposure position, less force is required for lifting.

In the present embodiment, the front shaft 305Fa provided on the front cam 305F and the rear shaft 305Ra provided on the rear cam 305R are respectively inserted into the front long hole 306Fb and the rear long hole 306Rb provided on the elevating member 306. By doing so, the movement direction of the elevating member 306 is regulated in accordance with the ascending operation of the elevating member 306. However, the present invention is not limited to this. For example, shaft members other than the front shaft 305Fa and the rear shaft 305Ra may be inserted into the front long hole 306Fb and the rear long hole 306Rb provided in the elevating member 306. In addition to the front cam 305F, the rear cam 305R, and the elevating member 306, a mechanism for regulating the moving direction of the elevating member 306 may be provided.
In the present embodiment, the front elongated hole 306Fb provided in the elevating member 306 has a linear shape extending along one direction so that the rotation angle θ and the angle difference α have a linear relationship. However, the present invention is not limited to this. For example, the shape of the elongated hole may be a curved shape or a partially bent shape so that the rotation angle θ and the angle difference α have a linear relationship. Absent.

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 10 ... Image formation process part, 12 ... Photosensitive drum, 14 ... LED print head (LPH), 17 ... Advance / retreat mechanism, 171 ... Housing | casing, 172 ... Lever, 173 ... Link mechanism, 173a ... Holding Part, 173b ... support part, 178F ... front regulating member, 301 ... first link member, 302 ... second link member, 303 ... center coil spring, 304F ... front coil spring, 304R ... rear coil spring, 305F ... front cam, 305R ... rear cam 306 ... Lifting member, PM ... Photoconductor module, EM ... Exposure module

Claims (10)

An image carrier,
An exposure member that exposes the image carrier;
A support member that supports the exposure member such that the exposure member moves between a retracted position away from the image carrier and an exposure position closer to the image carrier than the retracted position;
A moving member that includes a rotating shaft having a fixed position and a rotating body that is attached to the rotating shaft and connected to the support member, and moves the exposure member from the retracted position toward the exposure position along with the rotation. When,
When the exposure member is moved from the retracted position to the exposure position via the support member by rotating the movement member, the direction of the force received by the support member via the movement member and the support member An image forming apparatus including a guide unit that guides the support member so that an angle difference from a moving direction is smaller at the exposure position than at the retracted position.   The guide means is a direction inclined to a predetermined side with respect to a direction from the exposure member toward the image carrier when the exposure member is moved from the retracted position to the exposure position via the support member. The image forming apparatus according to claim 1, wherein the support member is guided.   The image forming apparatus according to claim 1, wherein the guide unit guides the support member linearly.   The said guide means guides the said supporting member so that the said angle difference may change linearly when moving the said exposure member from the said retracted position to the said exposure position. The image forming apparatus according to claim 1.   The guide means guides the support member so that the angular difference is minimized at the exposure position when the exposure member is moved from the retracted position to the exposure position via the support member. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. An exposure member for exposing the image carrier;
A support member that supports the exposure member such that the exposure member moves between a retracted position away from the image carrier and an exposure position closer to the image carrier than the retracted position;
A moving member that includes a rotating shaft having a fixed position and a rotating body that is attached to the rotating shaft and connected to the support member, and moves the exposure member from the retracted position toward the exposure position along with the rotation. When,
When the exposure member is moved from the retracted position to the exposure position via the support member by rotating the movement member, the direction of the force received by the support member via the movement member and the support member An exposure apparatus including guide means for guiding the support member so that an angular difference from the moving direction is smaller at the exposure position than at the retracted position. An image carrier,
An exposure member having an exposure part for exposing the image carrier;
The exposure member is moved from a predetermined retracted position in a first direction that is the optical axis direction of the exposure unit to advance the exposure unit to a predetermined exposure position with respect to the image carrier, and the exposure An advancing / retreating mechanism for moving the exposure member in a direction opposite to the first direction from the position and retracting the exposure unit to the retracted position;
The advance / retreat mechanism is:
A housing that is provided along a second direction from the one end side to the other end side of the image holding body in the axial direction of the image holding body, and the position with respect to the image holding body is fixed;
A rotation that includes a shaft that extends in a third direction intersecting the first direction and the second direction and that is attached in a state where the position is fixed to the housing, and a rotating body that rotates about the shaft. Members,
The rotating member has an elongated hole through which the shaft passes, and is mounted with the exposure member and connected to the rotating body of the rotating member, and the exposure member is moved to the retracted position or the exposure as the rotating body rotates. Including a mounting member to be moved to a position,
When the mounting member is moved from the retracted position to the exposure position, the angular difference between the direction of the force received by the mounting member via the rotating member and the direction of the slot provided in the mounting member is An image forming apparatus, wherein the exposure position is smaller than the retracted position.   The elongated hole provided in the mounting member is formed to be inclined in either the second direction or a direction opposite to the second direction and facing the first direction. The image forming apparatus according to claim 7.   The image forming apparatus according to claim 7, wherein the elongated hole provided in the mounting member has a linear shape.   The image forming apparatus according to claim 7, wherein the angular difference is minimized at the exposure position while the mounting member is moved from the retracted position to the exposure position.

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