JP2016218469A - Image formation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image formation apparatus in which the relative positions of an LED unit and a photoreceptor drum are determined with attachment of a cartridge.SOLUTION: The first peak is generated in the reaction force received by a cartridge 10 when the cartridge 10 presses a pull-up member 111 and a push-up member 121 against the energization force of the pull-up member 111 and the push-up member 121 at the time when the cartridge 10 is inserted to the apparatus body. The second peak is generated in the reaction force received by the cartridge 10 when the cartridge 10 presses an LED unit push-up cam 101 against the energization force of a pressing spring 36 of an LED unit 30 at the time when the cartridge 10 is inserted to the apparatus body. The timing at which the cartridge 10 presses the pull-up member 111 and the push-up member 121 is made different from the timing at which the cartridge presses the LED unit push-up cam 101 at the time of insertion of the cartridge 10.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an image forming apparatus for forming an image on a recording material by an electrophotographic method, and more particularly to an image forming apparatus capable of performing maintenance by replacing a cartridge including a photosensitive member.

  In an electrophotographic image forming apparatus, a photosensitive member is generally integrated with a toner container, a developing unit, or the like into a cartridge, and maintenance is easily performed by replacing the cartridge. Such a cartridge is positioned at an image forming position for image formation in a state of being mounted on the main body of the image forming apparatus.

  By the way, when using an exposure member that exposes the photosensitive member in which a plurality of light emitting elements are arranged in an array, when mounting the cartridge, the exposure member is not only positioned at the image forming position but also the photosensitive member. Needs to be positioned.

  Patent Document 1 discloses a configuration in which the cartridge is positioned at the image forming position while the exposure member and the photosensitive member are positioned by closing the opening / closing cover and pressing the exposure member against the cartridge by a spring. ing.

Japanese Patent Laid-Open No. 05-035003

  An object of the present invention is to provide an image forming apparatus in which an LED unit and a photosensitive drum are relatively positioned by mounting a cartridge.

  The present invention relates to an image forming apparatus in which a cartridge having a photosensitive drum that is driven to rotate is mounted in a predetermined mounting position by moving in the rotational axis direction of the photosensitive drum, and an electrostatic latent image is formed on the photosensitive drum. An LED array in which a plurality of LED light emitting elements that emit light for forming a light source are arranged in an array in a direction substantially parallel to the rotation axis of the photosensitive drum, and a lens array through which the light emitted from the LED array passes And a positioning mechanism for determining a relative position in the optical axis direction of the lens included in the lens array of the LED unit and the photosensitive drum of the cartridge mounted at the predetermined mounting position; And the positioning mechanism is provided outside the one end of the LED array in the longitudinal direction of the LED array. A first spring and a second spring provided outside the other end of the LED array, the first spring and the second spring being elastically deformable in the optical axis direction of the lens; A cam mechanism that elastically deforms the first spring and the second spring by the movement of the cartridge when the cartridge is mounted on the forming apparatus, and the cartridge is mounted at the predetermined mounting position. The first spring and the second spring are contracted by the action of the cam mechanism in this state than during the movement of the cartridge when the cartridge is mounted at the predetermined position. Due to the contraction of the first spring and the second spring in the mounted state, the LED unit is moved in the optical axis direction. The photosensitive drum and the relative position of the LED unit of the cartridge mounted to the predetermined mounting position by the force of use, characterized in that is determined.

  According to the present invention, the relative position of the LED unit with respect to the photosensitive drum can be determined by mounting the cartridge.

1 is a schematic cross-sectional view showing an overall configuration of an image forming apparatus. FIG. 3 is a schematic cross-sectional view around the cartridge in the image forming apparatus. The perspective view which looked at the image forming apparatus at the time of cartridge mounting from diagonally forward. FIG. 3 is a schematic perspective view around a cartridge in the image forming apparatus. FIG. 3 is a partial cross-sectional view of the image forming apparatus when a cartridge is attached and detached. FIG. 3 is a partial cross-sectional view of the image forming apparatus when a cartridge is attached and detached. FIG. 3 is a partial cross-sectional view of the image forming apparatus when a cartridge is attached and detached. FIG. 3 is a partial cross-sectional view of the image forming apparatus when a cartridge is attached and detached. FIG. 3 is a partial cross-sectional view of the image forming apparatus in a state where a cartridge is mounted. (A) The graph which shows the operation force required when a cartridge presses a raising member and a raising member at the time of insertion of a cartridge. (B) The graph which shows the operating force at the time of a cartridge pressing an LED raising cam at the time of insertion of a cartridge. (C) The graph which shows the operation force at the time of insertion of a cartridge. The perspective view which looked at the image forming apparatus from diagonally forward. FIG. 3 is a partial cross-sectional view of the image forming apparatus when a cartridge is attached and detached. FIG. 3 is a partial cross-sectional view of the image forming apparatus in a state where a cartridge is mounted. FIG. 6 is a perspective view of a part of the image forming apparatus around the inner opening / closing member and the cartridge guide as viewed obliquely from above. FIG. 3 is a cross-sectional view of the periphery of the cartridge of the image forming apparatus as viewed from the axial direction of the photosensitive drum. FIG. 3 is a partial perspective view of the image forming apparatus in a state where a cartridge is placed on a guide member that is pulled out from the apparatus main body. FIG. 3 is a partial cross-sectional view of the image forming apparatus when a cartridge is attached and detached. FIG. 3 is a partial cross-sectional view of the image forming apparatus when a cartridge is attached and detached.

<First Embodiment>
[Entire configuration of image forming apparatus]
First, the overall configuration of the image forming apparatus will be described. The image forming apparatus of this embodiment is an electrophotographic color image forming apparatus. FIG. 1 is a schematic cross-sectional view showing the overall configuration of the image forming apparatus 1.

In the image forming apparatus 1, a sheet feeding unit 80 is disposed at the bottom. The sheet feeding means 80 accommodates a sheet as a recording material. A registration roller unit 50 that arranges and conveys the registration of the sheet is disposed in the upper right portion of the sheet feeding unit 80. Four cartridges 10 (10Y, 10M, 10C, and 10K are disposed above the sheet feeding means 80. An LED unit 30 described later is disposed between the cartridges 10 to expose the photosensitive drum 11. The cartridges. An intermediate transfer unit 40 is disposed above 10 so as to face the cartridge 10. The intermediate transfer unit 40 includes an intermediate transfer belt 41. A primary transfer roller 42 (42Y) is provided inside the intermediate transfer belt 41. 42M, 42C, 42K), an intermediate transfer belt driving roller 43, a secondary transfer counter roller 44, a tension roller 45, and an intermediate transfer belt cleaning means 46. A secondary transfer unit 90 is provided on the right side of the intermediate transfer unit 40. And a secondary transfer roller 91 is provided so as to face the secondary transfer counter roller 44. The fixing unit 20 is disposed above the intermediate transfer unit 40 and the secondary transfer roller 91. A paper discharge unit 60 is disposed at the upper left of the fixing unit 20. The paper discharge unit 60 is a discharge unit. A paper roller pair 61, a double-sided conveyance unit 62, a reverse roller pair 63, and a double-sided flapper 64 serving as a branching unit are provided.
[Cartridge configuration]
Next, a description will be given of the configuration of a cartridge that includes a member for image formation, is detachable from the image forming apparatus 1, and performs image formation in a state of being attached to the image forming apparatus 1. Each of the cartridges 10 (10Y, 10M, 10C, and 10K) is a process cartridge including a photosensitive drum 11 (11Y, 11M, 11C, and 11K) and a process unit that operates on the photosensitive drum 11 (11Y, 11M, 11C, and 11K). Four cartridges 10 (10Y, 10M, 10C, 10K) can be attached to and detached from the apparatus main body 1. These four cartridges 10 are different in that they form toner images of different colors and store yellow (Y), magenta (M), cyan (C), and black (K) toners, respectively. Other than that, since the four cartridges 10 have the same structure, the following description will be made representatively as one cartridge 10. Similarly, members and the like provided in the cartridge 10 will be described as representatives.

  FIG. 2 is a schematic cross-sectional view around the cartridge 10 in the image forming apparatus 1. The cartridge 10 is integrally composed of two units, a cleaner unit 17 and a developing unit 14.

  The cleaner unit 17 includes a photosensitive drum 11, a charging roller 12, a cleaning blade 161, and a waste toner container 162. The photosensitive drum 11 is configured by applying an organic photoconductive layer (OPC) to the outer peripheral surface of an aluminum cylinder. The photosensitive drum 11 is rotatably supported at both ends in the axial direction by flanges, and rotates by receiving a driving force from a driving motor (not shown) in the apparatus main body 1.

  The charging roller 12 is a conductive roller, and this roller is brought into contact with the surface of the photosensitive drum 11. By applying a charging bias voltage at the time of contact, the surface of the photosensitive drum 11 is uniformly charged. The transfer residual toner remaining on the surface of each photosensitive drum 11 after the primary transfer is removed by the cleaning blade 161. The removed toner is collected in a waste toner container 162.

  The developing unit 14 includes a developing roller 142, a toner supply / recovery roller 143, a toner supply / recovery roller 143, and a toner storage unit 144.

The toner is attached to the electrostatic latent image and developed as a toner image. The developing roller 142 is adjacent to the photosensitive drum 11, is rotated by a driving force of a driving motor (not shown) in the apparatus main body 1, and develops the photosensitive drum 11 by applying a developing bias voltage. The toner supply / collection roller 143 supplies toner from the toner storage unit 144 to the developing roller 142 and collects toner that has not developed the photosensitive drum 11.
[Configuration of LED unit 30]
Next, the configuration of the LED unit 30 (30Y, 30M, 30C, 30K) will be described.

  The LED unit 30 is disposed between the developing unit 14 and the cleaner unit 17 of the four cartridges 10 mounted on the apparatus main body 1, exposes the photosensitive drum 11 based on the image information, and electrostatic latent image on the photosensitive drum 11. Form an image. Since the four LED units 30 (30Y, 30M, 30C, and 30K) have the same structure, the following description will be made representatively as one LED unit 30. In addition, the member with which the LED unit 30 is provided is demonstrated as a representative similarly.

  The LED unit 30 includes an LED frame 31, an LED head 32, an LED head 32 as an exposure member, a cartridge pressing member 35 (see FIG. 5), and a pressing spring 36.

  The LED head 32 includes an LED array 33 in which a plurality of LED light emitting elements are arranged in an array according to a predetermined pixel pitch in the main scanning direction, and a lens array 34 through which light from each LED light emitting element of the LED array 33 is transmitted. Are unitized. The LED array 33 emits light based on the image data to be formed, irradiates the rotating photosensitive drum 11 with light, and exposes the photosensitive drum 11.

  The LED frame 31 includes an LED head 32, a cartridge pressing member 35, and a pressing spring 36.

  The LED head 32 and the cartridge pressing member 35 are integrally configured, and are configured to be positioned at the exposure position by being urged and abutted toward the cartridge 10 at the image forming position. Therefore, the LED head 32 and the cartridge pressing member are freely moved by a predetermined amount in the vertical direction (Z direction) and the axial direction of the photosensitive drum 11 with respect to the LED frame 31 while being urged upward by the pressing spring 36. It is supported by the LED frame 31 as possible.

Further, the LED unit 30 can be retracted from the cartridge so as not to obstruct the movement of the cartridge 10 when the cartridge 10 is detached from the apparatus main body 1. Specifically, the LED unit 30 is supported by the cartridge guide 100 via the LED unit push-up cam 101 (see FIG. 5) so as to be movable in the vertical direction (Z direction).
[Image forming operation]
Next, a color image forming operation of the image forming apparatus 1 of the present embodiment will be described. The image forming operation is executed in a state where the cartridge 10 is mounted on the apparatus and is at the image forming position. As described above, the photosensitive drum 11 is driven and rotated in the A direction (FIG. 2). In this state, the surface of the photosensitive drum 11 is uniformly charged by the charging roller 12, and is exposed by the LED unit 30, whereby an electrostatic latent image is formed on the surface. Further, a toner image is formed on the surface of the photosensitive drum 11 by attaching toner to the electrostatic latent image by the developing roller 142. This toner image is transferred from the surface of the photosensitive drum 11 onto the intermediate transfer belt 41 by applying a transfer bias at a position where the surface of the photosensitive drum 11 faces the primary transfer roller 42.

  The intermediate transfer belt 41 transfers the toner image in a superimposed manner at a position facing each of the photosensitive drums (11Y, 11M, 11C, 11K), and the toner image as a superimposed image in which the four color toner images are superimposed is the intermediate transfer belt 41. Formed on top. The toner image is collectively transferred from the intermediate transfer belt 41 onto the sheet supplied from the paper feeding unit 80 at a timing facing the secondary transfer roller 44.

The sheet on which the toner image has been transferred is conveyed to the fixing unit 20, and is heated and pressed by the fixing unit 20, whereby the toner image is fixed on the sheet, and is discharged out of the apparatus by the paper discharge unit 60. Is done. An image is formed on the sheet by the operation as described above.
[Mounting of the cartridge 10 to the main body]
Next, attachment of the cartridge 10 to the image forming apparatus 1 will be described. FIG. 3 is a perspective view of the image forming apparatus 1 when the cartridge 10 is mounted as viewed obliquely from the front. In the present embodiment, the cartridge 10 is configured to be detachable from the apparatus main body 1 by moving the cartridge 10 in the direction of the rotation axis of the photosensitive drum 11 and inserting it into the apparatus main body 1 or pulling it out from the apparatus main body 1. Such a configuration in which the cartridge 10 is attached and detached is called a so-called side-oriented configuration.

  When the cartridge 10 is attached to the image forming apparatus 1, the opening / closing member 70 is opened with respect to the apparatus main body 1 to expose the opening 71. From the opening 71, four cartridge guides 100 (100Y, 100M, 100C, 100K) arranged in a line in a direction orthogonal to the axis of the photosensitive drum 11 are exposed. The cartridge 10 can be attached to the apparatus main body 1 by inserting the cartridge 10 in the F direction so as to sandwich the cartridge guide 100 between the cleaner unit 17 and the developing unit 14. FIG. 3 shows a state where the cartridge 10M is already mounted in the apparatus main body 1 and the cartridge 10Y is being inserted into the apparatus main body 1.

  As described above, in the configuration in which the cartridge 10 is attached / detached by inserting the cartridge 10 into the apparatus main body 1 in the axial direction of the photosensitive drum 11, the photosensitive drum 11, the intermediate transfer belt 41, and the like are attached when the cartridge 10 is attached / detached. There is a risk that the member adjacent to the photosensitive drum 11 in the apparatus main body 1 may be rubbed and damaged. Therefore, the cartridge 10 is configured to be inserted in a direction perpendicular to the axis of the photosensitive drum 11 with the cartridge 10 retracted from the intermediate transfer belt 41 and the like by a predetermined distance.

  In this embodiment, since the intermediate transfer belt 41 is disposed above the photosensitive drum 11, when the cartridge 10 is inserted, the cartridge 10 is initially retracted below the intermediate transfer belt 41. Immediately before the insertion of the cartridge 10 is completed, the cartridge 10 is moved upward against gravity, and the photosensitive drum 11 and the intermediate transfer belt 41 arrive at an adjacent image forming position.

  Thus, in the configuration in which the cartridge 10 is moved in the direction orthogonal to the axis of the photosensitive drum 11 by pushing up against the gravity when the cartridge 10 is inserted, the pusher is larger than that for moving the cartridge 10 in the other direction. Pressure is required.

  Further, as described above, in the present embodiment, the LED unit 30 is moved upward, and the LED head 32 is pressed toward the cartridge 10 to position the LED head 32 at the exposure position. For this reason, if the timing at which the cartridge 10 is pushed upward and the timing at which the LED unit 30 is moved upward always coincide, the peak of the reaction force received by the user when the cartridge 10 is mounted appears at the same time. Becomes larger.

  Therefore, in the present embodiment, the timing of the peak of the reaction force received by the user when the cartridge 10 is mounted is shifted.

  Next, a configuration for moving the cartridge 10 upward and positioning in the apparatus main body 1 will be described in detail.

  FIG. 4 is a schematic perspective view around the cartridge 10 in the image forming apparatus 1. The cartridge 10 is shown in the middle of insertion. In the apparatus, the front side plate 110 and the rear side plate 120 are provided so as to be arranged at both ends in the axial direction (F direction) of the photosensitive drum 11 in a state where the cartridge 10 is mounted. Further, positioned portions 13 a and 13 b for determining the position of the photosensitive drum 11 in the apparatus main body 1 are provided at both axial ends of the photosensitive drum 11 of the cartridge 10.

  The front plate 110 is provided with a lifting member 111 as a first moving member that lifts the lifted portion 113 after being pushed down by the lifted portion 113 of the cartridge 10 immediately before the insertion of the cartridge 10 is completed. The lifting member 111 is rotatably provided with the shaft 118 as a center of rotation, and is biased upward (in the Z direction) by a lifting spring 116 that is hooked on the hook portion 117 of the front side plate 110. Further, abutting portions 112a and 112b are formed on the front side plate 110.

  The rear side plate 120 is provided with a push-up member 121 as a first moving member that pushes up the pushed-up portion 123 after being pushed down by the pushed-up portion 123 of the cartridge 10 immediately before the insertion of the cartridge 10 is completed. The push-up member 121 is provided so as to be rotatable about a shaft 128 and is urged upward (Z direction) by a push-up spring 126. Further, the rear plate 120 is formed with abutting portions 122a and 122b.

  The cartridge 10 is moved upward by the lifting member 111 and the pushing member 121 when inserted into the apparatus main body 1.

  Next, a configuration in which the cartridge 10 is mounted on the apparatus main body 1 and positioned at the image forming position, and the LED unit 30 and the LED head 32 are positioned on the cartridge 10 will be described.

  FIG. 5 is a partial cross-sectional view of the image forming apparatus 1 when the cartridge 10 is attached and detached. This cross section includes the axis of the photosensitive drum 11 and is a cross section parallel to the Z direction.

  In this state, the LED unit including the LED head 32 is located at the retracted position retracted downward with respect to the photosensitive drum 11 of the cartridge 10.

  From this state, the cartridge 10 is inserted into the apparatus main body 1 in the axial direction (F direction) of the photosensitive drum 11. As shown in FIG. 6, first, the to-be-lifted portion 113 of the cartridge 10 contacts the lifting member 111, and the lifting member 111 is rotated downward about the shaft 118 (FIG. 4). At the same time, the pushed-up portion 123 of the cartridge 10 comes into contact with the push-up member 121, and the push-up member 121 is rotated downward around the shaft 128 (FIG. 4).

  When the cartridge 10 is further inserted in the F direction, the to-be-lifted portion 113 rides on the lifting surface 114 (FIG. 4) of the lifting member 111 as shown in FIG. At the same time, the pushed-up portion 123 rides on the push-up member 121. Thus, the cartridge 10 presses the lifting member 111 and the lifting member 121 and rides on them. As a result, the cartridge 10 is moved upward by a predetermined amount by the urging force of the lifting spring 116 of the lifting member 111 and the lifting spring 126 of the lifting member 121.

  Further, at this time, the cam contact surface 103 provided on the cartridge 10 contacts the cartridge contact surface 102 provided on the LED unit push-up cam 101 as the second moving member.

  When the cartridge 10 is further inserted in the F direction from this state, as shown in FIG. 8, the LED unit push-up cam 101 is pressed by the cartridge 10 and moved in the F direction. Then, the cam surface 104 for pushing up the LED unit 30 of the LED unit push-up cam 101 comes into contact with the cam surface 105 of the LED unit 30, and the LED unit 30 is pushed upward (Z direction) toward the photosensitive drum 11.

  When the LED unit 30 is pushed upward, the cartridge push-up member 35 urged upward by the pressing spring 36 of the LED unit 30 contacts the cartridge 10 and presses the cartridge 10. As a result, the cartridge 10 is further moved upward.

  As shown in FIG. 9, the positioned portions 13a and 13b (FIG. 4) are abutting portions 112a and 112b (FIG. 4) of the front side plate 110, and abutting portions 122a and 122b (FIG. 4) of the rear side plate 120. I hit it. As a result, the position of the cartridge 10 in the vertical direction (Z direction) and in the direction perpendicular to the vertical direction with respect to the cartridge insertion direction (F direction) is determined.

  At the same time, a part of the cartridge 10 hits the rear side plate 120 in the cartridge insertion direction (F direction), and the position in the cartridge insertion direction (F direction) is determined.

  As described above, the cartridge 10 reaches the image forming position and is positioned.

  Further, the cartridge pressing member 35 is fitted into the fitting hole 106 of the cartridge 10, whereby the LED head 32 of the LED unit 30 with respect to the cartridge 10 in the main scanning direction (F direction) and the sub scanning direction (F direction and Z direction). Positioning in the orthogonal direction) is performed. In this way, the LED head 32 reaches the exposure position and is positioned.

  The cartridge 10 is positioned at the image forming position by the resultant force of the pulling member 111, the pushing member 121 (FIG. 8), and the cartridge pressing member 35 of the LED unit 30, and the toner image is transferred to the intermediate transfer belt 41. Sufficient pressing force is generated.

  In this embodiment, the cartridge 10 moves on the lifting member 111 and the pushing member 121 to move the cartridge 10 upward by a predetermined amount. However, at this time, the cartridge 10 does not hit the abutting portions 112a and 112b and the abutting portions 122a and 122b. This is because when the cartridge 10 is further inserted after that in order to move the LED unit 30 upward, the cartridge 10 is disposed with the intermediate transfer unit 40 disposed above the front side plate 110, the rear side plate 120, and the cartridge 10. This is to avoid contact and rubbing.

However, if the distance at which the cartridge 10 is inserted to move the LED unit 30 upward is relatively short, the cartridge 10 rides on the lifting member 111 and the pushing member 121, so that the cartridge 10 is moved to the abutting portions 112a, 112b, and the protruding portion. It is good also as a structure which abuts against this part 122a, 122b.
[Removal of the cartridge 10 from the apparatus main body]
Next, the removal of the cartridge 10 from the apparatus main body 1 will be described. As shown in FIG. 9, when the cartridge 10 is completely inserted into the apparatus main body, the engaging portion 107 of the cartridge 10 and the engaging portion 108 of the LED unit push-up cam 101 are engaged. For this reason, when the cartridge 10 is pulled out in the direction opposite to the F direction from the state shown in FIG. 9, the LED unit push-up cam 101 is also moved in the direction opposite to the F direction. At this time, the LED unit 30 moves downward as the cam surface 105 slides on the cam surface 104 of the LED unit push-up cam 101. For this reason, the cartridge pressing member 35 is detached from the fitting hole 106 of the cartridge 10, and the LED head 32 moves from the exposure position to the retracted position. At the same time, the cartridge 10 also moves downward by a predetermined amount, retreats from the image forming position, and becomes in the state shown in FIG.

In this state, the engagement between the engagement portion 107 of the cartridge 10 and the engagement portion 108 of the LED unit push-up cam 101 is released. For this reason, the cartridge 10 can be further pulled out in the direction opposite to the F direction. When the cartridge 10 is further pulled out in the direction opposite to the F direction, the cartridge 10 is detached from the lifting member 111 and the pushing member 121, moves downward by a predetermined amount, and the cartridge 10 can be detached from the apparatus main body.
[Operation force when the cartridge 10 is inserted into the apparatus main body 1]
Next, the operation force necessary for inserting the cartridge 10 into the apparatus main body 1 and positioning it at the image forming position and positioning the LED head 32 at the exposure position will be described.

  FIG. 10A is a graph showing the operating force required when the cartridge 10 presses the lifting member 111 and the lifting member 121 when the cartridge 10 is inserted. The place where the operating force increases is until the cartridge 10 presses the lifting member 111 and the lifting member 121, pushes down these members, and rides up. The peak (maximum value) of the operating force at this time occurs when the lifting spring 116 is most extended and when the lifting spring 126 is most contracted.

  This operating force can be rephrased as a reaction force that the cartridge 10 receives when the cartridge 10 presses the lifting member 111 and the lifting member 121 against the urging force of the lifting spring 116 and the lifting spring 126. FIG. 10B is a graph showing the operating force when the cartridge 10 presses the LED push-up cam 101 when the cartridge 10 is inserted. The location where the operating force increases is while the cam surface 104 of the LED push-up cam 101 that is pressed and moved by the cartridge 10 pushes up the cam surface 105 of the LED unit 30. The peak (maximum value) of the operating force at this time occurs when the pressing spring 36 of the LED unit 30 is most contracted.

  This operating force can be rephrased as a reaction force received by the cartridge 10 when the cartridge 10 presses the LED unit push-up cam 101 against the urging force of the pressing spring 36 of the LED unit 30.

  As described above, when the cartridge 10 is inserted, the operating force peaks when the pulling member 111 and the push-up member 121 are pressed and when the LED push-up cam 101 is pressed.

  FIG. 10C is a graph showing the operating force when the cartridge 10 is inserted. The operating force becomes [α] while the cartridge 10 presses the lifting member 111 and the lifting member 121, and the cam surface 104 of the LED lifting cam 101 that is pressed and moved by the cartridge 10 pushes up the cam surface 105 of the LED unit 30. [Β] during the period. As described above, in this embodiment, the timing at which the cartridge 10 presses the lifting member 111 and the lifting member 121 when the cartridge 10 is inserted is different from the timing at which the LED lifting cam 101 is pressed. Accordingly, the timing at which the peak of the operating force when the cartridge is inserted is shifted (different).

As described above, in this embodiment, after the cartridge 10 is moved upward by a predetermined amount, the LED unit 30 is moved upward, and the cartridge 10 is divided into a plurality of times in order to reach the image forming position. It is moved upward. For this reason, compared with the configuration in which the cartridge 10 is moved upward and moved to the image forming position at the same time as the LED unit 30 is moved upward, the maximum value of the operating force required when inserting the cartridge is reduced. Usability can be improved.
Second Embodiment
Next, a second embodiment will be described. In the first embodiment, the cartridge 10 is positioned at the image forming position in conjunction with the insertion of the cartridge 10 and the LED unit 30 is pushed upward. In contrast, in the present embodiment, the cartridge 10 is positioned at the image forming position in conjunction with the insertion of the cartridge 10, the LED unit 30 is moved in conjunction with the closing operation of the opening / closing member 70 for inserting the cartridge 10, The LED head 32 is moved to the exposure position.

In the description of the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, description thereof is omitted, and different points will be described.
[Mounting of the cartridge 10 to the main body]
A mounting operation when mounting the cartridge 10 to the image forming apparatus 1 in this embodiment will be described.

  FIG. 11 is a perspective view of the image forming apparatus 1 as viewed obliquely from the front. In the image forming apparatus 1, an inner opening / closing member 72 that can be opened / closed with respect to the apparatus main body is provided inside the opening / closing member 70. The inner opening / closing member 72 is configured to open / close in conjunction with the opening / closing member 70, and the opening 71 is opened by opening the opening / closing member 70 and the inner opening / closing member 72. When replacing the cartridge 10, the opening / closing member 70 and the inner opening / closing member 72 are opened to open the opening 71. By opening the opening 71, the four cartridge guides 100 arranged in parallel in the apparatus main body are exposed.

  The cartridge 10 is inserted into the apparatus main body 1 along the cartridge guide 100 in the axial direction (F direction) of the photosensitive drum 11. As in the first embodiment, the raised portion 113 of the cartridge 10 abuts on the lifting member 111 and rotates the lifting member 111 downward about the shaft 118. At the same time, the pushed-up portion 123 of the cartridge 10 contacts the push-up member 121 and rotates the push-up member 121 downward about the shaft 128.

  When the cartridge 10 is further inserted in the F direction, the pulled-up portion 113 rides on the lifting surface 114 of the lifting member 111 as shown in FIG. At the same time, the pushed-up portion 123 rides on the push-up member 121. Thus, the cartridge 10 presses the lifting member 111 and the lifting member 121 and rides on them. As a result, the cartridge 10 is moved upward by the urging force of the lifting spring 116 of the lifting member 111 and the lifting spring 126 of the lifting member 121.

  Then, as shown in FIG. 12, the positioned portions 13 a and 13 b abut against the abutting portions 112 a and 112 b of the front side plate 110 and the abutting portions 122 a and 122 b of the rear side plate 120. Thereby, the position of the cartridge 10 in the vertical direction (Z direction) and the direction perpendicular to the vertical direction with respect to the cartridge insertion direction (F direction) is determined (see FIG. 4).

  At the same time, a part of the cartridge 10 hits the rear side plate 120 in the cartridge insertion direction (F direction), and the position in the cartridge insertion direction (F direction) is determined.

  As described above, the cartridge 10 reaches the image forming position and is positioned. In this state, the pressing force sufficient to position the cartridge 10 at the image forming position and transfer the toner image to the intermediate transfer belt 41 by the resultant force of the pressing force of the lifting member 111 and the lifting member 121 (FIG. 8). Will occur.

  The inner opening / closing member 72 is provided with a cam pressing portion 203 that contacts and presses the pressed surface 202 of the LED unit push-up cam 101. An engaging portion 230 is provided at the tip of the cam pressing portion 203.

  FIG. 14 is a view of a part of the image forming apparatus 1 around the inner opening / closing member 72 and the cartridge guide 100 as viewed from above. When the opening / closing member 70 is closed, as shown in FIG. 14A, the engagement portion 230 of the cam pressing portion 203 of the inner opening / closing member 72 is engaged with the inner opening / closing member engagement portion 231 of the LED unit push-up cam 101. Match.

  When the opening / closing member 70 is further closed, as shown in FIG. 14B, the cam pressing portion 203 comes into contact with the pressed surface 202, and the LED unit push-up LED unit push-up cam 101 is moved in the F direction.

  As described above, by moving the LED unit push-up cam 101 in the F direction, the LED unit 30 is moved upward as in the first embodiment, and the cartridge push-up member 35 is fitted into the fitting hole 106 of the cartridge 10. Match. Thereby, as shown in FIG. 13, the LED head 32 is positioned at the exposure position.

When removing the cartridge 10 from the apparatus main body 1, the inner opening / closing member 72 is opened by opening the opening / closing member 70. At this time, the LED unit push-up cam 101 in which the inner opening / closing member engaging portion 231 is engaged with the engaging portion 230 of the cam pressing portion 203 of the inner opening / closing member 72 is interlocked with the operation of opening the inner opening / closing member 72, F Move in the opposite direction. As in the first embodiment, the LED unit 30 moves downward and the LED head 32 moves from the exposure position to the retracted position. From this state, the cartridge 10 can be detached from the apparatus main body 1 by pulling out the cartridge 10 in the direction opposite to the F direction.
[Operation force when the cartridge 10 is attached to the apparatus body 1]
Next, the operation force required to insert the cartridge 10 into the apparatus main body 1, close the opening / closing member 70, position the cartridge 10 at the image forming position, and position the LED head 32 at the exposure position will be described.

  The point where the operation force required when the cartridge 10 is inserted has a peak until the cartridge 10 presses the pulling member 111 and the push-up member 121 and pushes these members down to ride up. Further, at a place where a peak appears in the operation force required when closing the opening / closing member 70, the cam pressing portion 203 presses the pressed surface 202 to move the LED unit push-up cam 101 in the F direction, and the cam surface 104. While the cam surface 105 of the LED unit 30 is pushed up.

As described above, in this embodiment, the cartridge 10 is moved upward to move to the image forming position in conjunction with the insertion of the cartridge 10, and then the LED unit 30 is moved upward in conjunction with closing of the opening / closing member 70. Thus, the LED head 32 is moved to the exposure position. For this reason, it is possible to reduce the maximum value of the required operating force as compared with the configuration in which the cartridge 10 is moved upward at once at the same timing as the LED unit 30 is moved upward and positioned at the image forming position. Become. Therefore, the operation force required when mounting the cartridge 10 is reduced, and usability is improved.
<Third Embodiment>
Next, a third embodiment will be described. This embodiment is different from the first embodiment in that the guide member for guiding the insertion of the cartridge 10 is configured to be able to be pulled out from the apparatus main body 1 according to the attachment and detachment of the cartridge 10. In the present embodiment, a case where the guide member can be pulled out as a cartridge mounting member on which the cartridge 10 is mounted will be described.

In the description of the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, description thereof is omitted, and different points will be described.
[Drawer Configuration of Guide Member 51]
First, the guide member pull-out configuration will be described. FIG. 15 is a cross-sectional view of the periphery of the cartridge 10 of the image forming apparatus 1 according to the present embodiment as viewed from the axial direction of the photosensitive drum 11. FIG. 16 is a partial perspective view of the image forming apparatus 1 in a state where the cartridge 10 is placed on the guide member 51 that is pulled out from the apparatus main body. The exterior portion of the image forming apparatus 1 is not shown.

  The guide member 51 is a thin plate-like member that is long in the front-rear direction and protrudes upward, and is movable in the axial direction of the photosensitive drum 11 along the rail 20a provided on the upper surface frame 20 corresponding to the rail groove 51c. It is arranged. Further, the guide member 51 has a width direction restriction wall (a portion that can contact the cartridge 10) 58 that guides the left and right direction of the cartridge 10, and a vertical direction restriction wall 59 that guides the vertical direction of the cartridge 10. The longitudinal restriction walls 59 are provided on the left and right sides of the guide member 51 along the axial direction of the photosensitive drum 11 (longitudinal direction of the guide member 51). Further, the opening 71 side (front side) of the guide member 51 has a handle 64 (FIG. 17) that the user holds to pull out the guide member 51 to the opening 71 side.

  The LED unit 30 is disposed inside the guide member 51. The LED unit 30 is held by the LED holding rail 51d formed inside the guide member 51 and the LED holding housing 154 fixedly disposed on the upper frame 20, and is not pulled out even when the guide member 51 is pulled out. This is a configuration that remains fixed within the apparatus main body 1.

  FIG. 17 is a sectional view of the photosensitive drum 11 in the axial direction. In this embodiment, an LED unit push-up mechanism 150 including a push-up cam 153 is provided as a mechanism for moving the LED unit 30 up and down and moving the LED head 32 between the retracted position and the exposure position. Two LED unit push-up mechanisms 150 are provided in the axial direction of the photosensitive drum 11.

The LED unit push-up mechanism 150 will be described. A total of two push-up cams 153 are provided for each LED unit 30, one on the upstream side and one on the downstream side in the F direction. The cam holding member 151 fixed to the upper frame 20 is held rotatably in the direction of arrow E. A toggle spring 152 is stretched between the push-up cam 153 and the cam holding member 151. One end of the toggle spring 152 is supported by the stretched portion 151 a of the cam holding member 151. The other end is supported by a stretching portion 153 a provided below the push-up cam 153. With such a configuration, the push-up cam 153 is a toggle mechanism.
[Mounting of the cartridge 10 to the main body]
Next, attachment of the cartridge 10 to the image forming apparatus 1 will be described. When the cartridge is mounted, the guide member 51 corresponding to the cartridge 10 to be mounted is pulled out to the opening 71 side (front side). In this state, the cartridge 10 is placed on the guide member 51 so that the guide member 51 enters the space between the cleaner unit 17 and the developing unit 14 of the cartridge 10. In this state, the vertical regulating wall 59 and the bottom surface of the cartridge 10 are in contact with each other.

  Further, in the state where the guide member 51 is pulled out to the opening 71 side, the guide member 51 is fixed in a state where it is urged in the direction of being pulled out from the apparatus main body 1 by a toggle mechanism (not shown). For this reason, even when the cartridge is inserted in the F direction, the guide member 51 stays in the state of being pulled out toward the opening 71 against the frictional force between the cartridge 10 and the guide member 51, and only the cartridge 10. Slides on the guide member 51 and moves in the F direction. At this time, slopes 58a (FIG. 16) are formed along the length on both the left and right sides of the upper portion of the guide member 51 so that the cartridge 10 can be easily inserted.

  When the cartridge 10 is inserted until the contact surface 66 of the cartridge 10 contacts the contact surface 65 of the guide member 51, the contact surface 65 of the guide member 51 is pressed by the contact surface 66 of the cartridge 10. As a result, the biasing that biased the guide member 51 of the toggle mechanism in the direction of being pulled out from the apparatus main body 1 is released. Therefore, thereafter, the cartridge 10 and the guide member 51 are integrally inserted in the F direction toward the inside of the apparatus main body.

  As shown in FIG. 18A, the pulled-up portion 113 provided in the cartridge 10 abuts on the lifting member 111. At the same time, the pushed-up portion 123 of the cartridge 10 contacts the push-up member 121. As shown in FIG. 18B, when the cartridge 10 is pressed in the F direction as in the first embodiment, the cartridge 10 rides on the lifting member 111 and the lifting member 121 and moves by a predetermined amount in the Z direction. At this time, as in the first embodiment, the cartridge 10 does not abut against the abutting portions 112a and 112b and the abutting portions 122a and 122b. In this state, the cam 153 is biased to rotate in the direction of arrow D by the toggle spring 152.

  18A to 18D, the push-up member 121 of the rear side plate 120 is not shown. Further, as for the push-up cam 153, the one on the downstream side in the F direction moves in the same manner as the one on the upstream side in the F direction, and therefore illustration and description thereof are omitted.

  Further, when the cartridge 10 is inserted in the F direction, the cam contact surface 51 a provided on the guide member 51 contacts the push-up cam 153 as shown in FIG. As the guide 51 moves in the F direction, the abutment surface 51a moves, so that the push-up cam 153 is pushed, and the push-up cam 153 is rotated in the arrow C direction against the biasing force of the toggle spring 152. . At that time, the cam surface 153b provided on the push-up cam 153 presses the bottom surface of the LED unit 30 and moves the LED unit 30 upward.

  When the cartridge 10 is further inserted, as shown in FIG. 18C, the tension portion 153a of the toggle spring 152 reaches a neutral position indicated by a one-dot chain line. When the extending portion 153a exceeds the neutral position, the toggle spring 152 urges the push-up cam 153 to rotate in the direction of arrow C, and the push-up cam 153 further rotates in the direction of arrow C. 30 moves further upward. Then, as shown in FIG. 18 (d), the cartridge 10 is moved upward by being pushed by the cartridge push-up member 35 provided in the LED unit 30, and the positioned portions 13 a and 13 b are protruded from the front plate 110. It abuts against the abutting portions 122a and 112b and the abutting portions 122a and 122b of the rear plate 120. Thus, the position of the cartridge 10 in the vertical direction (Z direction) and in the direction perpendicular to the vertical direction with respect to the cartridge insertion direction (F direction) is determined.

  Then, the guide member 51 pressed by the cartridge 10 hits a stopper portion (not shown) provided on the side plate 120 in the F direction and further insertion movement of the cartridge 10 and the guide member 51 is prevented. At this time, the portion of the push-up cam 153 that contacts the LED unit 30 is vertically above the center of rotation of the push-up cam 153 and is configured to be arranged side by side in the vertical direction. For this reason, the reaction force for rotating the push-up cam 153 is directed toward the center of rotation of the push-up cam 153 due to the weight of the LED unit 30 or the like, so the push-up cam 153 is not rotated and is held in this state.

  At the same time, as in the first embodiment, a cartridge pressing member 35 (not shown) urged upward by a pressing spring 36 (not shown) of the LED unit 30 is fitted into a fitting hole (not shown) of the cartridge 10. Thus, the positioning of the LED head 32 with respect to the cartridge 10 in the main scanning direction (F direction) and the sub-scanning direction (direction orthogonal to the F direction and the Z direction) is performed. In this way, the LED head 32 reaches the exposure position and is positioned. Further, when the LED head 32 is positioned at the exposure position, the cartridge 10 also reaches the image forming position and is positioned.

The cartridge 10 is positioned at the image forming position by the resultant force of the pulling member 111, the pushing member 121, and the cartridge pressing member 35 of the LED unit 30, and the pressing force sufficient to transfer the toner image to the intermediate transfer belt 41. Pressure is generated.
[Removal of the cartridge 10 from the apparatus main body]
Next, the removal of the cartridge 10 from the apparatus main body 1 will be described. As shown in FIG. 18D, from the state where the cartridge 10 is mounted on the apparatus main body 1 and is at the image forming position, the handle 64 is grasped and the guide member 51 is pulled out in the direction opposite to the F direction. Then, the cam contact surface 51 b provided on the guide member 51 contacts the push-up cam 153 and rotates the push-up cam 153 in the direction of arrow D. At that time, the LED unit 30 moves downward along the cam surface 153b. Therefore, the cartridge pressing member 35 is detached from the fitting hole of the cartridge 10 and the LED head 32 moves from the exposure position to the retracted position. At the same time, the cartridge 10 also moves downward by a predetermined amount and retreats from the image forming position.

  When the guide member 51 is further pulled out, as shown in FIG. 18C, the tensioning portion 153a of the toggle spring 152 exceeds the neutral position of the toggle mechanism, and the push-up cam 153 is urged in the arrow D direction by the toggle spring 152. It becomes like this. When the guide member 51 is pulled out to the position shown in FIG. 18B, the push-up cam 153 is restricted from rotating by a rotation stopper (not shown).

  When the guide member 51 is further pulled out, the abutting surface 66 is pressed against the abutting surface 65 of the guide member 51, and the cartridge 10 pulled out integrally with the guide member 51 is detached from the lifting member 111 and the pushing member 121, and reaches a predetermined amount. Move down. In this way, by pulling out the guide member 51 toward the opening 71, the cartridge 10 can be pulled out and the cartridge 10 can be detached from the apparatus main body 1.

  As described above, in the present embodiment, as in the first embodiment, the timing at which the cartridge 10 presses the lifting member 111 and the lifting member 121 when the cartridge 10 is inserted is different from the timing at which the lifting cam 153 is pressed. ing. Therefore, the timing at which the peak of the operating force appears when the cartridge is inserted is shifted.

  That is, in this embodiment, the cartridge 10 is moved upward by a predetermined amount, and then the LED unit 30 is moved upward. In order to reach the cartridge 10 to the image forming position, the cartridge 10 is moved upward several times. It is moved. For this reason, compared with the configuration in which the cartridge 10 is moved upward and moved to the image forming position at the same time as the LED unit 30 is moved upward, the maximum value of the operating force required when inserting the cartridge is reduced. Usability can be improved.

  In the present embodiment, the center of gravity of the cartridge 10 is outside the apparatus main body 1 in the longitudinal direction of the cartridge 10 (axial direction of the photosensitive drum 11) in a state where the guide member 51 is pulled out from the apparatus main body 1 toward the opening 71. It was made to arrange.

As a result, the user can grip a portion corresponding to the center of gravity of the cartridge 10 in the longitudinal direction of the cartridge 10. Therefore, it is possible to work while holding the cartridge without receiving the moment of the center of gravity of the cartridge 10 as compared with the case where the cartridge 10 is inserted into the apparatus main body 1 or taken out from the apparatus main body 1 by holding the end of the cartridge 10 in the longitudinal direction. And usability is good.
<Other embodiments>
In the first to third embodiments, replacement of the cartridge 10 having a side-oriented configuration in which the cartridge 10 is inserted into and removed from the apparatus main body 1 by inserting the cartridge 10 in the axial direction of the photosensitive drum 11 has been described. However, the cartridge 10 is applied to a configuration in which the cartridge 10 is pulled out in a direction different from the direction in which the cartridge 10 and the LED unit 30 are arranged and perpendicular to the axial direction of the photosensitive drum 11 (for example, JP 2009-128506 A). Is also possible.

  Even in such a configuration, when the cartridge 10 is attached or detached, it is necessary to move the cartridge 10 and the LED unit 30 in the direction in which the cartridge 10 and the LED unit 30 are aligned. Therefore, the timing at which the cartridge 10 is moved in the direction in which the cartridge 10 and the LED unit 30 are arranged is different from the timing at which the LED unit 30 is moved in the direction in which the cartridge 10 and the LED unit 30 are arranged. With this configuration, it is possible to reduce the maximum value of the required operating force.

1 Image forming apparatus 10 Cartridge (10Y, 10M, 10C, 10K)
11 Photosensitive drum (11Y, 11M, 11C, 11K)
14 Developing unit 17 Cleaner unit 20 Fixing unit 30 LED unit 40 Intermediate transfer unit 50 Registration roller unit 60 Paper discharge unit 62 Double-sided conveyance unit 80 Paper feed means 90 Secondary transfer unit 100 Cartridge guide (100Y, 100M, 100C, 100K)
101 LED unit push-up cam 111 Lifting member 121 Push-up member

Claims (3)

An image forming apparatus in which a cartridge having a photosensitive drum that is rotationally driven is mounted at a predetermined mounting position by moving in a rotational axis direction of the photosensitive drum,
An LED array in which a plurality of LED light emitting elements that emit light for forming an electrostatic latent image on the photosensitive drum are arranged in an array in a direction substantially parallel to the rotation axis of the photosensitive drum, and the LED array An LED unit comprising a lens array through which the emitted light is transmitted;
A positioning mechanism for determining a relative position of the photosensitive drum of the cartridge mounted at the predetermined mounting position and a lens included in the lens array of the LED unit in the optical axis direction;
The positioning mechanism is
A first spring provided outside one end of the LED array in a longitudinal direction of the LED array and a second spring provided outside the other end of the LED array, the optical axis of the lens A first spring and a second spring that are elastically deformable in a direction;
A cam mechanism that elastically deforms the first spring and the second spring by the movement of the cartridge when the cartridge is attached to the image forming apparatus,
The first spring and the second spring in a state where the cartridge is mounted at the predetermined mounting position of the cartridge when the cartridge is mounted at the predetermined position by the action of the cam mechanism in the state. The predetermined contraction is caused by a force acting on the LED unit in the optical axis direction due to contraction of the first spring and the second spring in a state where the cartridge is contracted as compared with the movement and the cartridge is mounted at the predetermined mounting position. An image forming apparatus characterized in that a relative position of the photosensitive drum and the LED unit of the cartridge mounted at the mounting position is determined. An image forming apparatus in which a cartridge having a rotationally driven photosensitive drum is mounted at a predetermined mounting position by sliding in a rotational axis direction of the photosensitive drum,
An LED array in which a plurality of LED light emitting elements that emit light for forming an electrostatic latent image on the photosensitive drum are arranged in an array in a direction substantially parallel to the rotation axis of the photosensitive drum, and the LED array An LED unit comprising a lens array through which the emitted light is transmitted;
A positioning mechanism for determining a relative position of the photosensitive drum of the cartridge mounted at the predetermined mounting position and a lens included in the lens array of the LED unit in the optical axis direction;
The positioning mechanism is
A first spring that is elastically deformable in the optical axis direction of the lens, and an elastic deformation that is elastically deformable in the optical axis direction of the lens, and the cartridge is mounted at the predetermined position rather than the first spring. A second spring provided downstream in the moving direction of the photosensitive drum;
A cam mechanism that elastically deforms the first spring and the second spring by the movement of the cartridge when the cartridge is attached to the image forming apparatus,
The first spring and the second spring in a state where the cartridge is mounted at the predetermined mounting position of the cartridge when the cartridge is mounted at the predetermined position by the action of the cam mechanism in the state. The predetermined contraction is caused by a force acting on the LED unit in the optical axis direction due to contraction of the first spring and the second spring in a state where the cartridge is contracted as compared with the movement and the cartridge is mounted at the predetermined mounting position. An image forming apparatus characterized in that a relative position of the photosensitive drum and the LED unit of the cartridge mounted at the mounting position is determined. An image forming apparatus in which a cartridge having a photosensitive drum that is rotationally driven is mounted at a predetermined mounting position by moving in a rotational axis direction of the photosensitive drum,
An LED array in which a plurality of LED light emitting elements that emit light for forming an electrostatic latent image on the photosensitive drum are arranged in an array in a direction substantially parallel to the rotation axis of the photosensitive drum, and the LED array An LED unit comprising a lens array through which the emitted light is transmitted;
A positioning mechanism for determining a relative position of the photosensitive drum of the cartridge mounted at the predetermined mounting position and a lens included in the lens array of the LED unit in the optical axis direction;
The positioning mechanism is
A first spring provided outside one end of the LED array in a longitudinal direction of the LED array and a second spring provided outside the other end of the LED array, the optical axis of the lens A first spring and a second spring that are elastically deformable in a direction, and a cam that elastically deforms the first spring and the second spring by the movement of the cartridge when the cartridge is attached to the image forming apparatus. A mechanism,
The first spring and the second spring when the cartridge is mounted at the predetermined mounting position are in a state where the front cartridge is not mounted at the predetermined mounting position by the action of the cam mechanism in the state. The first spring and the second spring contract more than the second spring, and the first spring and the second spring contract in the optical axis direction when the cartridge is mounted at the predetermined mounting position. An image forming apparatus, wherein a relative position between the photosensitive drum and the LED unit of the cartridge mounted at the predetermined mounting position is determined by a force acting on the LED unit.

Images