JP2010002491A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve work efficiency in attaching/detaching an intermediate transfer unit, and to reduce an image forming device in size. <P>SOLUTION: This image forming device is equipped with an intermediate transfer unit 10 having an intermediate transfer body 18, and a frame 11 for supporting it; and a sensor unit 50 having a positioning member 56 in contact with the intermediate transfer body 18, and an image reading sensor 54 for reading an image on the intermediate transfer unit 10. The image forming device body 2 is provided with a lock mechanism 70 for locking the sensor unit 50 at a retreat position separated from the intermediate transfer unit 10. The frame 11 is provided with a guide part 62 in contact with the sensor unit 50 and guiding the unit to the retreat position, when the intermediate transfer unit 10 is slid in a removal direction from the image forming device body 2, and when the intermediate transfer unit 10 is slid in an insertion direction into the image forming device body 2, the lock mechanism 70 is released. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus.

  2. Description of the Related Art Conventional color image forming apparatuses such as copying machines and printers employ an intermediate transfer method in which a plurality of color toner images are once transferred onto an intermediate transfer belt and collectively transferred onto a sheet.

  In the intermediate transfer system, since it is necessary to superimpose toner images of respective colors, it is necessary to prevent positional deviation of the toner images. As a countermeasure for this, an image reading sensor (IDC sensor) is provided (for example, see Patent Document 1).

  The IDC sensor includes a light emitting unit and a light receiving unit. Light is emitted from the light emitting portion to the intermediate transfer bell. The light receiving unit detects light reflected by the intermediate transfer belt. The timing of forming the toner image of each color is adjusted by reading the image of each color by the IDC sensor. Since the image on the intermediate transfer belt is detected by the IDC sensor, it is usually necessary to keep the positions of the IDC sensor and the intermediate belt constant.

When replacing the intermediate transfer belt, it is necessary to take out the intermediate transfer unit. For example, in Patent Document 1, an IDC sensor unit is provided above the intermediate transfer unit. Normally, the frame of the intermediate transfer unit is in contact with the IDC sensor unit, and the positions of the IDC sensor and the intermediate belt are maintained. When pulling out the intermediate transfer unit, the intermediate transfer unit is temporarily lowered, and the intermediate transfer unit is pulled out while avoiding the IDC sensor unit.
JP 2004-29525 A

  However, in the above-described method, since the intermediate transfer unit needs to be moved greatly, the image forming apparatus becomes large, and problems such as poor detachment workability occur.

  An object of the present invention is to improve the workability of attaching / detaching an intermediate transfer unit and to reduce the size of an image forming apparatus.

  In order to solve the above-mentioned problems, an invention according to claim 1 is an image forming apparatus, comprising an intermediate transfer unit and an intermediate transfer unit that has a frame that supports the intermediate transfer body and slides relative to the image forming apparatus main body. The image forming apparatus comprising: a positioning member that contacts the intermediate transfer member; and an image reading sensor that reads an image on the intermediate transfer unit, and a sensor unit that moves in a direction intersecting a sliding direction of the intermediate transfer unit. The main body is provided with a lock mechanism that locks the sensor unit at a retracted position away from the intermediate transfer unit, and the frame is slid when the intermediate transfer unit is slid in a direction of taking out from the image forming apparatus main body. And a guide portion that contacts the retracted position and is provided with the intermediate transfer unit. Characterized in that the unlocking member for releasing the locking mechanism when the sliding in the direction of insertion into the image forming apparatus main body is provided.

  According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the intermediate transfer unit includes an opposing member that sandwiches the intermediate transfer body with the positioning member. And

  According to a third aspect of the present invention, there is provided an image forming apparatus having an intermediate transfer body and a frame that supports the intermediate transfer body, and an intermediate transfer unit that slides relative to the main body of the image forming apparatus, and a positioning member that contacts the frame. And an image reading sensor for reading an image on the intermediate transfer unit, and a sensor unit that moves in a direction crossing a sliding direction of the intermediate transfer unit, and the image forming apparatus main body includes the sensor unit in the intermediate transfer A lock mechanism for locking at a retracted position away from the unit is provided, and a guide portion that contacts the positioning member and guides the frame to the retracted position when the intermediate transfer unit is slid in a direction of taking out from the image forming apparatus main body. And the intermediate transfer unit is inserted into the image forming apparatus main body. The lock release member for releasing the locking mechanism when sliding in the direction are provided and said.

  According to a fourth aspect of the present invention, there is provided the image forming apparatus, the intermediate transfer unit having an intermediate transfer body and a frame that supports the intermediate transfer body, and slidingly moving with respect to the image forming apparatus main body, and the intermediate transfer body abutting A positioning unit, a retracting guide member that contacts the frame, and an image reading sensor that reads an image on the intermediate transfer unit, and a sensor unit that moves in a direction intersecting a sliding direction of the intermediate transfer unit, and The apparatus main body is provided with a lock mechanism that locks the sensor unit at a retracted position away from the intermediate transfer unit, and the frame is retracted when the intermediate transfer unit is slid in a direction of taking out from the image forming apparatus main body. A guide portion is provided that contacts the guide member and guides the sensor unit to the retracted position. Rutotomoni, wherein the unlocking member for releasing the locking mechanism when sliding the intermediate transfer unit in a direction to be inserted into the image forming apparatus main body.

  A fifth aspect of the present invention is the image forming apparatus according to any one of the first to fourth aspects, wherein a plurality of rollers are arranged in the intermediate transfer unit in the sliding movement direction of the intermediate transfer body. The guide portion is provided between a detection position by the sensor unit and a position of a roller closest to the detection position.

  A sixth aspect of the present invention is the image forming apparatus according to the first to fifth aspects, wherein the guide portion is inclined with respect to the sliding movement direction of the intermediate transfer unit.

  A seventh aspect of the present invention is the image forming apparatus according to the first to sixth aspects, wherein the positioning member is provided in a cylindrical shape and freely rotatable.

  The invention according to an eighth aspect is the image forming apparatus according to any one of the first to seventh aspects, wherein the sensor unit is movable further away from the intermediate transfer unit than the retracted position. It is characterized by being.

  According to the first aspect of the present invention, the reading accuracy of the sensor can be improved by bringing the positioning member into contact with the intermediate transfer member. In addition, since the sensor unit is guided to the retracted position by the guide portion when the intermediate transfer unit is detached, it is possible to prevent interference between the intermediate transfer unit and the sensor unit and prevent damage to the intermediate transfer member and the sensor. Furthermore, since the sensor unit is locked by the lock mechanism at the retracted position, it is not necessary to provide a guide portion over the entire length of the intermediate transfer unit, and the guide portion can be reduced in size.

  According to the second aspect of the present invention, since the opposing member for holding the intermediate transfer member between the positioning member and the positioning member is provided, it is possible to prevent the intermediate transfer member from being bent or waved.

  According to the third aspect of the present invention, the positioning of the sensor unit can be performed by bringing the positioning member into contact with the frame of the intermediate transfer unit. Can do.

  According to the fourth aspect of the present invention, when the intermediate transfer unit is detached, the sensor unit is guided to the retracted position by the retracting guide member coming into contact with the guide portion, so that the interference between the intermediate transfer unit and the sensor unit is prevented. It is possible to prevent the intermediate transfer member and sensor from being damaged. On the other hand, since the positioning member is brought into contact with the intermediate transfer member, the retracting guide member is contacted, and the retracting guide member is not contacted, the reading accuracy of the sensor can be improved.

  According to the fifth aspect of the present invention, since the guide portion is provided between the detection position of the sensor unit and the position of the roller closest to the detection position, interference between the sensor unit and the roller is prevented. Can do.

  According to the sixth aspect of the invention, since the guide portion is inclined with respect to the sliding movement direction of the intermediate transfer unit, the sensor unit can be smoothly moved in accordance with the sliding movement of the intermediate transfer unit. .

  According to the seventh aspect of the invention, since the positioning member is provided in a cylindrical shape and freely rotatable, the stress applied to the intermediate transfer member can be reduced, and the life of the intermediate transfer member can be extended.

  According to the eighth aspect of the present invention, since the sensor unit can be moved further away from the intermediate transfer unit than the retracted position, even if the sensor unit is pushed further away from the retracted position by the guide portion. The sensor unit will not be damaged.

  Hereinafter, preferred embodiments for carrying out the present invention will be described with reference to the drawings. However, although various technically preferable limitations for implementing the present invention are given to the embodiments described below, the scope of the invention is not limited to the following embodiments and illustrated examples.

  FIG. 1 is a schematic configuration diagram of the image forming apparatus 1. The image forming apparatus 1 is a color page printer, in particular, a tandem type color page printer. In FIG. 1, the left is the front and the right is the rear.

  An intermediate transfer unit 10 is provided in the housing 2 of the image forming apparatus 1. The intermediate transfer unit 10 includes a frame 60 (see FIG. 2), and a secondary transfer driving roller 12, a driven roller 13, and platen rollers 14 to 17 are attached to the frame 60. The secondary transfer driving roller 12 is disposed on the rear side of the frame 60, and the driven roller 13 is disposed on the front side of the frame 60. The platen rollers 14 to 17 are arranged in order from the front between the driven roller 13 and the secondary transfer driving roller 12. An endless intermediate transfer belt 18 is hung on these rollers 11 to 17. These rollers 12 to 17 are provided to be rotatable with respect to the frame 60.

A counter member 19 is provided between the platen roller 17 and the secondary transfer driving roller 12. The facing member 19 contacts the inner surface of the intermediate transfer belt 18. The IDC sensor unit 50 is pressed against the opposing member 19 via the intermediate transfer belt 18. By providing the facing member 19, it is possible to prevent the intermediate transfer belt 18 to which the IDC sensor unit 50 is pressed from being bent or wavy.
The IDC sensor unit 50 is fixed to the housing 2.

  The intermediate transfer unit 10 can be taken out of the housing 2 by being slid rearward with the opening / closing door 4 described later open. Maintenance such as replacement of the intermediate transfer belt 18 is performed on the removed intermediate transfer unit 10.

  Photosensitive drums 21 are respectively attached below the platen rollers 14 to 17. The photosensitive drum 21 is provided so as to be rotatable with respect to the housing 2. Around the photosensitive drum 21, a cleaner unit 22, a charging unit 23, an exposure unit 24 and a developing unit 25 are attached. The cleaner unit 22 removes residual toner adhering to the peripheral surface of the photosensitive drum 21 from the photosensitive drum 21. The charging unit 23 charges the peripheral surface of the photosensitive drum 21. The exposure unit 24 forms a latent image on the peripheral surface of the photosensitive drum 21. The developing unit 25 develops a latent image by attaching toner to the peripheral surface of the photosensitive drum 21. Here, the developing unit 25 includes a toner container 26 storing toner, a developing cylinder 27 disposed at an exit portion of the toner container 26, and rollers 28 and 29 disposed in the toner container 26. The developing cylinder 27 and the rollers 28 and 29 are provided so as to be rotatable with respect to the toner storage 26, and the toner storage 26 is detachable from the housing 2 together with the developing cylinder 27 and the rollers 28 and 29.

  A photosensitive drum 21, a cleaner unit 22, a charging unit 23, an exposure unit 24, and a developing unit 25 are also provided below each of the platen rollers 15 to 17. Incidentally, yellow (Y) toner enters the toner container 26 of the developing unit 25 disposed below the platen roller 15 in the toner container 26 of the developing unit 25 disposed below the platen roller 14. In the developing unit 25 where the magenta (M) toner is disposed below the platen roller 16, the cyan (C) toner is developed below the platen roller 17. In the toner container 26 of the unit 25, black (K) toner is stored.

  In the following description, a module (having the photosensitive drum 21, the cleaner unit 22, the charging unit 23, the exposure unit 24, and the developing unit 25) provided below the platen roller 14 is referred to as a yellow image forming unit 20Y. The module provided below the platen roller 15 is referred to as a magenta image forming unit 20M, and the module provided below the platen roller 16 is referred to as a cyan image forming unit 20C. The module provided below the platen roller 17 Is referred to as a black image forming unit 20K.

  A conveyance roller 31 is attached to the housing 2 below the secondary transfer driving roller 12. A conveyance roller 31 is provided to be rotatable with respect to the housing 2. A conveyance roller 33 is attached to the housing 2 below the conveyance roller 31. A conveyance roller 33 is provided to be rotatable with respect to the housing 2.

  An opening / closing door 4 is attached to the rear portion of the housing 2. The open / close door 4 is rotatable about a fulcrum 5 provided at a lower portion thereof and is connected to the housing 2. When the open / close door 4 falls backward, the door is open, and when the open / close door 4 stands up, the door is closed. A pressure roller 30 and conveying rollers 32 and 34 are attached to the open / close door 4. The pressure roller 30 and the conveyance rollers 32 and 34 are provided to be rotatable with respect to the opening / closing door 4. When the open / close door 4 is closed, the intermediate transfer belt 18 is sandwiched between the pressure roller 30 and the secondary transfer driving roller 12, and the pressure roller 30 is connected to the secondary transfer driving roller 12 via the intermediate transfer belt 18. It is in pressure contact. On the other hand, when the open / close door 4 is open, the pressure roller 30 is separated from the secondary transfer driving roller 12 and the intermediate transfer belt 18. Further, when the open / close door 4 is closed, the transport roller 32 is pressed against the transport roller 31, and the transport roller 34 is pressed against the transport roller 33. On the other hand, when the open / close door 4 is opened, the transport roller 32 is separated from the transport roller 31 and the transport roller 34 is separated from the transport roller 33.

  A cassette 36 is mounted on the inner side of the housing 2 and at the lower part thereof. The cassette 36 is provided so as to be slidable with respect to the housing 2, whereby the cassette 36 can be attached to and detached from the housing 2. The cassette 36 contains paper 6.

  A paper feed roller 35 is attached to the housing 2 above the cassette 36 and below the transport rollers 33 and 34. The paper feed roller 35 is rotatably provided. The paper feed roller 35 is configured to contact the uppermost paper 6 among the stacked papers 6 when the cassette 36 is mounted on the housing 2.

  A fixing unit 37 is attached to the housing 2 inside the housing 2 and above the secondary transfer driving roller 12. The fixing unit 37 includes a fixing roller 38 provided rotatably with respect to the housing 2 and having a built-in heater, and a pressure roller 39 provided rotatably with respect to the housing 2 and pressed against the fixing roller 38. Prepare.

  Behind the fixing unit 37, paper discharge rollers 40 and 41 are attached to the housing 2. The paper discharge rollers 40 and 41 are in pressure contact with each other and are provided to be rotatable with respect to the housing 2. Of the upper surface of the housing 2, the portion behind the paper discharge rollers 40 and 41 is a paper receiver 3.

Here, the operation of the image forming apparatus 1 will be described.
First, by a motor (not shown), a paper feed roller 35, transport rollers 31 to 34, a pressure contact roller 30, a secondary transfer driving roller 12, a photosensitive drum 21 of the black image forming unit 20K, a developing cylinder 27 in the developing unit 25, and a roller 28. 29, the photosensitive drum 21, the developing cylinder 27, and the rollers 28, 29 are rotated.

  By rotating the paper feed roller 35, the paper 6 in the cassette 36 is transported between the transport rollers 33 and 34, and the paper 6 is transported between the intermediate transfer belt 18 and the pressure roller 30 by the transport rollers 31 to 34. It is conveyed to.

  On the other hand, when the secondary transfer driving roller 12 is rotated, the intermediate transfer belt 18 rotates. When the intermediate transfer belt 18 is rotating, the photosensitive drum 21 rotates in the black image forming unit 20K, the peripheral surface of the photosensitive drum 21 is charged by the charging unit 23, and the peripheral surface of the photosensitive drum 21 by the exposure unit 24. Is exposed, the peripheral surface of the photosensitive drum 21 is partially neutralized, whereby a latent image is formed on the peripheral surface of the photosensitive drum 21. Further, when the developing cylinder 27 rotates, the toner attached to the peripheral surface of the developing cylinder 27 adheres to the peripheral surface of the photosensitive drum 21, and the latent image is developed as a black image. The black image developed on the peripheral surface of the photosensitive drum 21 is transferred to the intermediate transfer belt 18.

  Similarly, the yellow image forming unit 20Y transfers the yellow image to the intermediate transfer belt 18, the magenta image forming unit 20M transfers the magenta image to the intermediate transfer belt 18, and the cyan image forming unit 20C transfers the cyan image to the intermediate transfer belt 18. The image is transferred to the transfer belt 18.

  Thus, a full-color mirror image is transferred to the intermediate transfer belt 18. When the intermediate transfer belt 18 and the paper 6 pass between the secondary transfer driving roller 12 and the pressure roller 30, the image on the intermediate transfer belt 18 is transferred to the paper 6.

  The sheet 6 on which the image has been transferred is conveyed to the fixing unit 37, and the sheet 6 passes between the fixing roller 38 and the pressure roller 39. At that time, the sheet 6 is heated by the fixing roller 38, and the toner attached to the sheet 6 is fixed to the sheet 6. The paper 6 is transported between the paper discharge rollers 40 and 41 and discharged onto the paper receiver 3 by the transport rollers 40 and 41.

  Here, the intermediate transfer unit 10 is provided with an image reading sensor unit (IDC sensor unit 50) in order to adjust the timing of forming a latent image on the photosensitive drums 21 of the image forming units 20Y, 20M, 20C, and 20K. It is done. The IDC sensor unit 50 is retracted downward along the frame 60 and locked by the lock mechanism 70 so as not to hinder removal of the intermediate transfer unit 10.

  2 is a schematic enlarged view showing the periphery of the intermediate transfer unit 10 of FIG. 1, and FIG. 3 is a view taken in the direction of arrow III in FIG. FIG. 4 is a diagram showing a state in which the intermediate transfer unit 10 is slid rearward. As shown in FIGS. 2 and 3, an IDC sensor unit 50 and a lock mechanism 70 are provided around the intermediate transfer unit 10.

  As shown in FIG. 3, the frame 60 is provided on the left and right of the intermediate transfer unit 10. Both ends of the secondary transfer driving roller 12, the driven roller 13, and the platen rollers 14 to 17 are attached to the frame 60.

  As shown in FIG. 2, a positioning part 61, a guide part 62, and a retracting part 63 are provided at the lower part of the frame 60. The positioning part 61 is provided in the lowermost part of the frame 60 and on the rearmost side. An IDC sensor unit 50 is disposed in the positioning unit 61 during normal operation of the image forming apparatus 1.

  The retracting portion 63 is provided in front of and below the positioning portion 61. As shown in FIG. 4, the IDC sensor unit 50 is disposed in the retreat unit 63 with the intermediate transfer unit 10 moved rearward.

  The guide part 62 smoothly connects the positioning part 61 and the retracting part 63. The guide part 62 is disposed behind the platen roller 17 and ahead of the opposing member 19. The IDC sensor unit 50 contacts the guide portion 62 when the intermediate transfer unit 10 is slid back. The IDC sensor unit 50 is pushed down along the guide portion 62 by sliding the intermediate transfer unit 10 backward. For this reason, the platen roller 17 and the IDC sensor unit 50 do not collide.

  In addition, as shown in FIGS. 2 and 3, the frame 60 is provided with unlocking members 64, 64 protruding left and right. The lock release members 64 and 64 release the lock of the IDC sensor unit 50 by the lock mechanism 70.

Here, the IDC sensor unit 50 will be described.
As shown in FIG. 1, the IDC sensor unit 50 is disposed behind the black image forming unit 20 </ b> K and above the conveyance roller 31 and below the intermediate transfer unit 10. The IDC sensor unit 50 includes a sensor guide 51, an urging member 52, a main body 53, a light emitting / receiving unit 54, a retracting guide member 55, and a positioning roller 56.

  The sensor guide 51 has a box shape with an open top, and a main body 53 is accommodated therein so as to be movable in the vertical direction. A biasing member 52 is provided at the bottom of the sensor guide 51. The biasing member 52 is a spring, for example, and biases the main body 53 upward. Note that the sensor guide 51 is sufficiently long, and the IDC sensor unit 50 will not be damaged even if the main body 53 is pushed further downward than the retracted position in FIG.

A light emitting / receiving unit 54 is provided inside the main body 53. The light emitting / receiving unit 54 includes a light emitting unit and a light receiving unit, and light is emitted upward from the light emitting unit. The light receiving unit detects the light reflected by the intermediate transfer belt 18. The timing for forming a latent image on the photosensitive drums 21 of the image forming units 20Y, 20M, 20C, and 20K is adjusted by a signal from the light emitting / receiving unit 54.
Further, an engaging portion 57 that engages with the lock mechanism 70 is provided on the rear side and the upper portion of the main body portion 53.

  As shown in FIGS. 2 and 3, retraction guide members 55, 55 are provided on the left and right ends of the upper portion of the main body 53, and positioning rollers 56, 56 are located on the inner side of the retraction guide members 55, 55. Is provided.

  The retraction guide member 55 contacts any one of the positioning portion 61, the guide portion 62, and the retraction portion 63 of the frame 11. The retracting guide member 55 is in contact with the positioning portion 61 in FIGS. 2 and 3 and the retracting portion 63 in FIG.

  The positioning roller 56 normally abuts on the intermediate transfer belt 18 and is pressed against the opposing member 19 via the intermediate transfer belt 18. Accordingly, the intermediate transfer belt 18 is sandwiched between the opposing member 19 and the positioning roller 56, and the distance between the light emitting / receiving unit 54 and the intermediate transfer belt 18 is appropriately maintained. The positioning roller 56 has a cylindrical shape and can be freely rotated, and rotates in accordance with the rotation of the intermediate transfer belt 18. For this reason, stress on the intermediate transfer belt 18 can be reduced, and the life of the intermediate transfer belt 18 can be extended.

Next, the lock mechanism 70 will be described.
The lock mechanism 70 includes a lock member 71 and an urging member 76.
As shown in FIGS. 2 and 3, the lock member 71 includes a rotation shaft 72, a lock portion 73, and an arm 74.

The rotation shaft 72 is provided in parallel with the secondary transfer driving roller 12, the driven roller 13, and the platen rollers 14 to 17 and rotatable with respect to the housing 2.
The lock portion 73 extends downward from one end of the rotating shaft 72. As shown in FIG. 4, the lower end of the lock portion 73 engages with the engagement portion 57 in a state where the IDC sensor unit 50 is retracted downward.

The arm 74 extends upward from the other end of the rotating shaft 73. A fixing portion 75 that fixes the biasing member 76 is provided at the upper end of the arm 74.
Further, as shown in FIG. 2, the arm 74 contacts the unlocking member 64 during the normal operation of the image forming apparatus 1.

  The urging member 76 is, for example, a spring. One end of the urging member 76 is fixed to the fixing portion 75, and the other end is fixed to a fixing portion 77 provided behind the arm 74 of the housing 2. The urging member 76 urges the lock member 71 in a direction in which the fixing portion 75 and the fixing portion 77 approach each other.

  During normal operation of the image forming apparatus 1, as shown in FIG. 2, the lock release member 64 contacts the arm 74, and the urging member 76 is stretched in the direction opposite to the urging direction. Further, the lower end of the lock portion 73 is not engaged with the engagement portion 57.

Next, operations of the IDC sensor unit 50 and the lock mechanism 70 when the intermediate transfer unit 10 is slid rearward will be described.
First, the opening / closing door 4 is opened, and the intermediate transfer unit 10 is slid backward. Then, the frame 11 moves rearward, and the guide portion 62 comes into contact with the retracting guide member 55 of the IDC sensor unit 50.

  When the intermediate transfer unit 10 is further retracted, the retracting guide member 55 is pushed down along the guide 62, and the main body 53 is pushed down to the retracted position against the elastic force of the biasing member 52 as shown in FIG. It is done.

  On the other hand, in the lock mechanism 70, the lock release member 64 moves rearward, whereby the arm 74 is pulled rearward by the biasing force of the biasing member 76, and the lock member 71 rotates around the rotation shaft 72 to lock the lock mechanism 70. Part 73 moves forward. Then, while the retracting guide member 55 is in contact with the retracting portion 63 of the frame 11, the lock portion 73 moves to the position of the engaging portion 57.

Thereafter, when the retracting portion 63 of the frame 11 is retracted from the retracting guide member 55, the main body portion 53 tends to be pushed up by the elastic force of the biasing member 52. However, since the engagement portion 57 is locked by the lock portion 73, the main body portion 53 is maintained at the lower retracted position. For this reason, the length of the evacuation part 63 can be shortened.
Thus, since the IDC sensor unit 50 is locked in a state where it is moved to the retracted position, the movement of the intermediate transfer unit 10 is not hindered.

  When the intermediate transfer unit 10 is returned to the position during normal operation (FIG. 2), first, the retracting guide member 55 contacts the retracting portion 63 of the frame 11. Next, the lock release member 64 moves forward and comes into contact with the arm 74, and moves the arm 74 forward against the biasing force of the biasing member 76. Then, the lock member 71 rotates around the rotation shaft 72, and the lock portion 73 moves backward. Then, while the retracting guide member 55 is in contact with the retracting portion 63 of the frame 11, the lock portion 73 is separated from the position of the engaging portion 57. As described above, the IDC sensor unit 50 is unlocked.

  Thereafter, the retracting guide member 55 moves along the guide portion 62, and the positioning roller 56 is brought into pressure contact with the opposing member 19 via the intermediate transfer belt 18.

  As described above, according to the present invention, since the IDC sensor unit 50 is locked by the lock mechanism 70 while being pushed down, the intermediate transfer unit 10 can be moved smoothly without greatly changing the height of the intermediate transfer unit 10. Therefore, the image forming apparatus 1 does not need to be enlarged.

  In the above embodiment, the retracting guide member 55 is in contact with the positioning unit 61 at the position where the positioning roller 56 contacts the intermediate transfer belt 18. However, the retracting guide member 55 and the positioning unit 61 are in contact with each other. It is not necessary to touch. In this case, since only the positioning roller 56 and the intermediate transfer belt 18 are in contact with each other, more accurate positioning can be performed.

  Alternatively, the distance between the light emitting / receiving unit 54 and the intermediate transfer belt 18 may be appropriately maintained by bringing the retracting guide member 55 and the positioning unit 61 into contact with each other. In this case, the retracting guide member 55 may have a cylindrical shape and a freely rotatable roller shape. The positioning roller 56 is not necessary. Since positioning is performed without direct contact with the intermediate transfer belt 18, wear of the intermediate transfer belt 18 can be prevented, and the life can be extended.

  Alternatively, the positioning roller 56 and the retracting guide member 55 may be an integral roller. During normal operation of the image forming apparatus 1, the roller is brought into contact with the intermediate transfer belt 18 and / or the positioning unit 61, and when the intermediate transfer unit 10 is slid backward, the roller is pushed down along the guide unit 62 and retracted. You may make it contact | abut with the part 63. FIG.

1 is a schematic configuration diagram of an image forming apparatus 1. FIG. FIG. 2 is a schematic enlarged view showing the periphery of an intermediate transfer unit 10 in FIG. 1. FIG. 3 is a view taken in the direction of arrow III in FIG. 2. FIG. 4 is a diagram illustrating a state in which the intermediate transfer unit is slid rearward.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Case (Image forming apparatus main body)
10 Intermediate transfer unit 11 Frame 50 IDC sensor unit 55 Retraction guide member 56 Positioning member 61 Positioning portion 62 Guide portion 63 Retraction portion 64 Unlocking member 70 Lock mechanism

Claims (8)

An intermediate transfer unit that has an intermediate transfer body and a frame that supports the intermediate transfer body and slides relative to the image forming apparatus main body;
A positioning member that contacts the intermediate transfer member, and an image reading sensor that reads an image on the intermediate transfer unit, and a sensor unit that moves in a direction crossing the sliding direction of the intermediate transfer unit,
The image forming apparatus main body is provided with a lock mechanism for locking the sensor unit at a retracted position away from the intermediate transfer unit,
The frame is provided with a guide portion that comes into contact with the sensor unit and guides it to a retracted position when the intermediate transfer unit is slid in the direction of taking out the intermediate transfer unit from the image forming apparatus main body.
An image forming apparatus, comprising: a lock release member that releases the lock mechanism when the intermediate transfer unit is slid in a direction in which the intermediate transfer unit is inserted into the image forming apparatus main body.   The image forming apparatus according to claim 1, wherein the intermediate transfer unit includes a facing member that sandwiches the intermediate transfer member with the positioning member. An intermediate transfer unit that has an intermediate transfer body and a frame that supports the intermediate transfer body and slides relative to the image forming apparatus main body;
A positioning unit that contacts the frame, and an image reading sensor that reads an image on the intermediate transfer unit, and a sensor unit that moves in a direction intersecting the sliding direction of the intermediate transfer unit,
The image forming apparatus main body is provided with a lock mechanism for locking the sensor unit at a retracted position away from the intermediate transfer unit,
The frame is provided with a guide portion that comes into contact with the positioning member and guides it to a retracted position when the intermediate transfer unit is slid in a direction of taking out from the image forming apparatus main body.
An image forming apparatus, comprising: a lock release member that releases the lock mechanism when the intermediate transfer unit is slid in a direction in which the intermediate transfer unit is inserted into the image forming apparatus main body. An intermediate transfer unit that has an intermediate transfer body and a frame that supports the intermediate transfer body and slides relative to the image forming apparatus main body;
A sensor unit that has a positioning member that comes into contact with the intermediate transfer member, a retraction guide member that comes into contact with the frame, and an image reading sensor that reads an image on the intermediate transfer unit, and moves in a direction intersecting the sliding direction of the intermediate transfer unit And
The image forming apparatus main body is provided with a lock mechanism for locking the sensor unit at a retracted position away from the intermediate transfer unit,
The frame is provided with a guide portion that comes into contact with the retraction guide member and guides the sensor unit to a retreat position when the intermediate transfer unit is slid in a direction to be taken out from the image forming apparatus main body.
An image forming apparatus, comprising: a lock release member that releases the lock mechanism when the intermediate transfer unit is slid in a direction in which the intermediate transfer unit is inserted into the image forming apparatus main body. In the intermediate transfer unit, a plurality of rollers are arranged in the slide movement direction of the intermediate transfer member,
The image according to any one of claims 1 to 4, wherein the guide portion is provided between a detection position by the sensor unit and a position of a roller closest to the contact position. Forming equipment.   The image forming apparatus according to claim 1, wherein the guide portion is inclined with respect to a sliding movement direction of the intermediate transfer unit.   The image forming apparatus according to claim 1, wherein the positioning member is provided in a cylindrical shape and is freely rotatable.   The image forming apparatus according to claim 1, wherein the sensor unit is further movable in a direction further away from the intermediate transfer unit than the retracted position.

Images