JP5077108B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus with improved operability.

  In general, in an image forming apparatus that forms an image on a recording sheet, a photosensitive unit (a “photosensitive cartridge” in Patent Document 1) having a plurality of photosensitive members arranged in parallel is provided in an opening provided in an upper portion of the apparatus main body. There are known ones in which the photosensitive member can be replaced by attaching and detaching from the part (see, for example, Patent Document 1). Also, after rotating the photoconductor unit around the support shaft in the main body and separating the photoconductor from the conveyor belt, the photoconductor unit can be removed from the opening at the top of the main body to replace the photoconductor. What has been made possible is also known (see, for example, Patent Document 2).

Japanese Patent Laid-Open No. 2003-43776 (FIGS. 2 and 16) Japanese Patent Laying-Open No. 2008-26361 (FIG. 2)

  By the way, in the conventional image forming apparatus as described above, the conveyance belt cannot be exposed unless the photosensitive unit is removed from the apparatus main body. Therefore, if the recording sheet is jammed between the photoconductor and the conveyor belt, the user first removes the photoconductor unit with both hands and places it so that the photoconductor is not damaged, and then the jammed recording sheet. It was necessary to carry out a complicated operation of removing the camera and mounting it again with both hands.

  Such a complicated operation may cause the user to avoid an appropriate operation when the recording sheet is jammed, and in some cases to perform an operation of forcibly pulling out the recording sheet from between the photosensitive member and the conveyance belt. There is. When the recording sheet is forcibly pulled out between the photosensitive member and the conveyance belt, the surface of the photosensitive member and the belt may be damaged by the recording sheet, resulting in a decrease in image quality.

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus with improved operability that can easily perform processing when a recording sheet is jammed between a photoreceptor and a belt.

In order to achieve the above-described object, an image forming apparatus of the present invention includes a main body case, a photoconductor unit that is detachably attached to the main body case and includes a plurality of photoconductors in parallel, and the plurality of photoconductors. An image forming apparatus comprising an endless belt disposed below and facing the plurality of photoconductors, and an upper cover that opens and closes an upper portion of the main body case, wherein the photoconductor unit includes the plurality of photoconductors. A separation grip provided at one end in the direction in which the bodies are arranged, and a rotation grip provided at the other end, and supported rotatably on the main body case around the one end. the other end portion of the photosensitive unit is rotated upward, in a state in which the one end was supported by the main body case, the photoreceptor and the jammed recording sheet removably between the belt structure so as to expose the belt And a lock mechanism that locks the support on the one end side of the photoconductor unit by the main body case so that the photoconductor unit cannot be detached from the main body case, and the lock by the lock mechanism is released. A lock release mechanism, which is operated to abut against the lock mechanism to operate the lock mechanism by a predetermined amount in a direction to release the lock and to move the photosensitive unit upward. When the rotation is more than a certain amount, the relative positional relationship between the lock mechanism and the lock release mechanism is changed by the rotation, so that the amount of operation of the lock mechanism when operated is reduced, and the lock is released. It is configured to be impossible .

  According to the image forming apparatus configured as described above, the photosensitive unit is lifted (rotated upward) with one hand without removing the photosensitive unit from the main body case, and the photosensitive member and the belt are moved with the other hand. It becomes possible to remove the recording sheet jammed in between.

  According to the image forming apparatus of the present invention, since the belt can be exposed only by rotating the photosensitive unit upward, the processing when the recording sheet is jammed between the photosensitive member and the belt is easily performed. be able to.

[First Embodiment]
<Overall configuration of color printer>
Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In the drawings to be referred to, FIG. 1 is a schematic diagram showing an overall configuration of a color printer as an example of an image forming apparatus.

  Here, in the following description, the direction will be described with reference to the user who uses the color printer. That is, in FIG. 1, the left side toward the paper surface is the “front” side, the right side toward the paper surface is the “rear” side, the back side toward the paper surface is the “left” side, and the front side toward the paper surface is “right”. ”Side. In addition, the vertical direction toward the paper surface is “up and down”.

  As shown in FIG. 1, the color printer 1 includes a paper feeding unit 20 that supplies a sheet P as an example of a recording sheet in a main body case 10 and an image forming unit 30 that forms an image on the fed paper P. And mainly.

  The main body case 10 is provided with an upper cover 11 that opens and closes an opening (not shown) provided in the upper portion of the main body case 10 so as to be able to rotate up and down about a rotating shaft 11A provided on the rear side. (See FIG. 4). An upper surface of the upper cover 11 serves as a paper discharge tray 12 that accumulates the paper P discharged from the main body case 10.

  The paper feeding unit 20 is provided at a lower portion in the main body case 10, and a paper feeding tray 21 that is detachably attached to the main body case 10, and a paper supply mechanism that supplies the paper P from the paper feeding tray 21 to the image forming unit 30. 22 is mainly provided. In the paper supply unit 20, the paper P in the paper supply tray 21 is separated one by one by the paper supply mechanism 22 and supplied to the upper image forming unit 30.

  The image forming unit 30 mainly includes four LED units 40, a photoreceptor unit 50, a transfer unit 60, and a fixing unit 70.

  The LED unit 40 is arranged to face the photosensitive drum 52 (photosensitive member) and is configured to expose the surface of the photosensitive drum 52 by an LED head (not shown) provided at the tip (lower end in FIG. 1). The LED unit 40 has an upper end attached to the upper cover 11 so as to be swingable. In addition, when the upper cover 11 is rotated upward, the LED unit 40 is interlocked with the rotation of the upper cover 11 or after the upper cover 11 is rotated by a known mechanism so that the tip thereof faces upward. (See FIG. 4).

  The photoconductor unit 50 is disposed between the upper cover 11 and the paper feeding unit 20, and includes four photoconductive drums 52 as an example of a plurality of photoconductors arranged in the front and rear in a photoconductor case 51 constituting an outer frame. And four chargers 53 arranged to face each photoconductor, and four developing cartridges 54 for supplying toner (developer) to each photoconductive drum 52.

  The photoconductor case 51 is detachably attached to the main body case 10 from the upper part of the main body case 10 with the upper cover 11 opened, and is supported by the main body case 10 so as to be rotatable around the rear end. (See FIGS. 5 and 6).

  Although not shown, the developing cartridge 54 mainly includes a developing roller and a supply roller that supply toner to the photosensitive drum 52, a layer pressure regulating blade that regulates the thickness of the toner on the developing roller, a toner accommodating portion that accommodates toner, and the like. In preparation. Each developing cartridge 54 has the same configuration except for the color of the toner accommodated therein.

  Although not shown, each developing cartridge 54 is detachably attached to the photoreceptor case 51. Therefore, by opening the upper cover 11, it is possible to remove and replace only the developing cartridge 54 from the main body case 10 (photosensitive member case 51).

  The transfer unit 60 is disposed between the paper feeding unit 20 and the photosensitive unit 50, and mainly includes a driving roller 61, a driven roller 62, a conveyance belt 63 as an example of a belt, and four transfer rollers 64. I have.

  The driving roller 61 and the driven roller 62 are spaced apart in parallel in the front-rear direction, and an endless conveying belt 63 is stretched therebetween. The conveyor belt 63 is disposed below each photosensitive drum 52, and the outer surface is in contact with each photosensitive drum 52. In addition, a transfer roller 64 that sandwiches the conveyance belt 63 with each photosensitive drum 52 is disposed inside the conveyance belt 63 so as to face each photosensitive drum 52. A transfer bias is applied to each transfer roller 64 during transfer.

  The fixing unit 70 is disposed behind the photoconductor unit 50 and the transfer unit 60, and mainly includes a heating roller 71 and a pressure roller 72 that is disposed to face the heating roller 71 and presses the heating roller 71.

  In the image forming unit 30 configured as described above, the surface of each photosensitive drum 52 is uniformly charged by the charger 53 and then exposed by each LED unit 40, whereby an image is formed on each photosensitive drum 52. An electrostatic latent image based on the data is formed. Then, toner is supplied from the developing cartridge 54 to the electrostatic latent image on the photosensitive drum 52 so that the electrostatic latent image is visualized, and a toner image is formed on the photosensitive drum 52.

  Thereafter, the paper P supplied from the paper supply unit 20 passes between the photosensitive drums 52 and the transfer rollers 64 disposed inside the conveying belt 63, so that the toner image on the photosensitive drums 52 is transferred. The images are sequentially transferred onto the paper P. Then, when the paper P passes between the heating roller 71 and the pressure roller 72, the toner image transferred onto the paper P is thermally fixed. The paper P on which the toner image is thermally fixed is discharged to the outside of the main body case 10 by the paper discharge roller 73 and accumulated on the paper discharge tray 12.

<Configuration of photoconductor unit>
Next, a configuration in which the photosensitive unit 50, which is a characteristic part of the present invention, is attachable / detachable / rotatable with respect to the main body case 10 will be described. 2 is a diagram showing the configuration of the photosensitive unit and the main body case, and FIG. 3 is a cross-sectional view taken along the line III-III in FIG.

  As shown in FIGS. 2 and 3, the photoconductor unit 50 includes a photoconductor case 51 that rotatably supports each photosensitive drum 52 and detachably supports each developing cartridge 54.

  The photoconductor case 51 is formed in a substantially box shape with an upper opening, and is provided with a rotation gripping portion 51A, a detachment gripping portion 51B, a front support shaft 51C, a rear support shaft 51D, and an unlocking mechanism 55. It has been.

  The rotation gripping part 51 </ b> A is formed in a substantially U shape in plan view, and is provided near the upper center of the outer surface of the front wall of the photoconductor case 51. The rotating grip 51A is a portion that is gripped by the user when the photosensitive unit 50 is rotated up and down and attached / detached.

  The separation gripping part 51 </ b> B is formed in a substantially rectangular shape in plan view, and is provided in the vicinity of the center of the rear upper part of the photoconductor case 51. The separation gripping part 51B is a part that the user grips together with the above-described rotation gripping part 51A when the photoreceptor unit 50 is attached or detached. The separation gripping part 51 </ b> B also serves as an operation part of the lock release mechanism 55.

The front support shaft 51 </ b> C extends outward in the left-right direction from the upper front side of the outer surface of the left and right side walls of the photoconductor case 51.
The rear support shaft 51D extends outward in the left-right direction from the upper rear side of the outer surfaces of the left and right side walls of the photoconductor case 51. Thereafter, the support shaft 51D is formed in a substantially cylindrical shape and serves as a rotation shaft when the photosensitive unit 50 is rotated up and down.

  The lock release mechanism 55 is a member for releasing the lock by the lock mechanism 15 to be described later, and includes a release bar 55A, a detaching gripping part 51B as an operation part for performing a release operation, two coil springs 55C, and an outer frame. It is mainly composed of a housing 55D that constitutes it.

  The separation gripping part 51B and the release bar 55A are integrally formed so as to have a substantially T shape in plan view, and are supported by the housing 55D so as to be slidable back and forth. A coil spring 55C is provided between the front wall of the housing 55D and the release bar 55A, and always urges the release bar 55A and the detaching gripper 51B toward the rear.

  Note that the detachment gripping portion 51B is formed to have a size such that the rear portion protrudes from the rear wall of the photoconductor case 51 when slid forward to secure a portion to be gripped by the user (FIG. 4). reference). Further, the release bar 55A protrudes outward from through holes (reference numerals omitted) at both left and right side walls of the housing 55D, and the release bar 55A slides forward when the photosensitive unit 50 is attached or detached. In such a case, the lock member 15A of the lock mechanism 15 is formed to have such a size that it can swing.

<Configuration of the main body case>
The main body case 10 is formed in a substantially box shape with an open top, and a front support groove 10C, a rear support groove 10D, and a lock mechanism 15 are provided therein.
The front support groove 10 </ b> C and the rear support groove 10 </ b> D are bottomed grooves that are recessed downward from the front edge or the rear edge of the left and right side walls of the main body case 10.

  The front support groove 10C and the rear support groove 10D are configured such that the front support shaft 51C or the rear support shaft 51D of the photoconductor case 51 mounted from above the main body case 10 is detachably engaged, whereby the photoconductor unit 50 is attached. The main body case 10 is detachably supported. The rear support shaft 51D engaged with the rear support groove 10D is disposed coaxially with the rotating shaft 11A (see FIG. 1) of the upper cover 11.

  The lock mechanism 15 locks the support on the rear end side of the photoconductor unit 50 by the main body case 10, specifically, prevents the rear support shaft 51 </ b> D from coming out of the rear support groove 10 </ b> D so 10 is a member that makes it impossible to detach from 10. The lock mechanism 15 is mainly composed of a lock member 15A and a tension spring 15C.

  The lock member 15A is formed in a substantially L shape in a side view, and is rotatably supported with respect to the main body case 10 by a support shaft 15B provided at the lower part. At the top of the lock member 15A, a retaining portion 15D that prevents the rear support shaft 51D from coming out of the rear support groove 10D, and the rear support shaft 51D is guided when the rear support shaft 51D engages with the rear support groove 10D. An inclined surface 15E is provided.

  One end of the tension spring 15C is attached to the lower end of the lock member 15A (below the support shaft 15B), and the other end is the main body case 10 (in front of the lock member 15A and from the inner surfaces of the left and right side walls of the main body case 10). (The part protruding inward in the left-right direction). As a result, the upper portion of the lock member 15A is always urged rearward, so that the retaining portion 15D is normally positioned above the rear support shaft 51D, and the rear support shaft 51D is removed from the rear support groove 10D. It is designed not to come out.

Next, the operation of the color printer 1 configured as described above will be described.
<Operation when attaching / detaching the photoconductor unit>
First, an operation when the photosensitive unit 50 is attached / detached (replaced) will be described. FIG. 4 is a view showing a state where the upper cover is opened and the lock release mechanism is operated, FIG. 5A is a view showing a state where the photoconductor unit 50 is removed, and FIG. 4B is a view showing a state where the photoconductor unit 50 is removed. FIG.

  As shown in FIG. 4, first, the upper cover 11 is pivoted upward to open, and an opening (reference number omitted) provided in the upper part of the main body case 10 is exposed. At this time, the LED unit 40 is held in a state in which the tip is directed upward by a known mechanism so as not to be an obstacle when the photoconductor unit 50 is attached and detached.

  Next, the turning grip 51A and the detachment grip 51B are gripped. At this time, the release bar 55A is slid forward by operating the operation part of the lock release mechanism 55, specifically, by pushing the release gripping part 51B forward. Then, the release bar 55A comes into contact with the lock member 15A (lock mechanism 15) and further presses forward, so that the lock member 15A swings forward (in the unlocking direction), and the retaining portion 15D Retreat from above the support shaft 51D.

  Then, as shown in FIG. 5A, by pulling up the gripping part 51A for rotation and the gripping part 51B for separation, the engagement between the front support shaft 51C and the front support groove 10C, the rear support shaft 51D, and the rear support While the engagement with the groove 10D is released, the photoreceptor case 51 (photoreceptor unit 50) is pulled upward, and the photoreceptor unit 50 is removed from the main body case 10 as shown in FIG. .

  Although not shown, when a new photoconductor unit 50 is attached to the main body case 10, first, the photoconductor unit 50 is lifted by holding the rotating gripping portion 51A and the detaching gripping portion 51B, and the front support unit 50 is supported. The positions of the shaft 51C and the front support groove 10C and the rear support shaft 51D and the rear support groove 10D are aligned. Then, the photoconductor unit 50 is moved downward, and the front support shaft 51C and the front support groove 10C and the rear support shaft 51D and the rear support groove 10D are engaged, so that the photoconductor unit 50 is attached to the main body case 10. Installed.

  At this time, the rear support shaft 51D is pressed against the inclined surface 15E of the lock member 15A by the downward movement. Accordingly, the lock member 15A swings forward, so that the rear support shaft 51D and the rear support groove 10D can be engaged with each other. After the rear support shaft 51D passes the lower end of the inclined surface 15E, the upper portion of the lock member 15A is urged rearward by the action of the tension spring 15C, so that the retaining portion 15D is located above the rear support shaft 51D. The rear support shaft 51D moves and is locked so as not to come out of the rear support groove 10D.

<Operation during jam processing>
Next, an operation when a sheet is jammed between the photosensitive drum 52 and the conveyance belt 63 (during jam processing) will be described. 6A is a view showing a state where the upper cover is opened and the photosensitive unit is rotated, and FIG. 6B is an enlarged view showing a positional relationship between the lock member and the unlocking mechanism when the photosensitive unit is rotated. is there.

  As shown in FIG. 6A, first, the upper cover 11 is pivoted upward to open, and an opening (reference numeral omitted) provided in the upper part of the main body case 10 is exposed. Next, the rotating grip 51A is gripped and lifted upward. Then, while the engagement between the front support shaft 51C and the front support groove 10C is released, the photoconductor case 51 (photoconductor unit 50) rotates upward with the rear support shaft 51D as a fulcrum (center).

  As a result, the paper (not shown) jammed between the photosensitive drum 52 and the conveyor belt 63 can be exposed to the extent that it can be removed by putting a hand through the opening provided in the upper part of the main body case 10. it can. As a result, the paper jammed between the photosensitive drum 52 and the conveyor belt 63 can be removed (jamming) with the other hand while lifting the rotating grip 51A (photosensitive unit 50) with one hand. .

  Here, when the photoconductor unit 50 is rotated, the retaining portion 15D of the lock mechanism 15 is normally positioned above the rear support shaft 51D, so that the rear support shaft 51D does not come out of the rear support groove 10D. It is like that. Further, the present embodiment is configured such that the lock mechanism 15 is not unlocked even when the release gripping portion 51B (the operation portion of the lock release mechanism 55) is operated when the photosensitive unit 50 is rotated.

  Specifically, as shown in FIG. 6B, when the photosensitive unit 50 is rotated upward by a predetermined amount or more, an unlocking mechanism 55 (release bar 55A) provided in the rotating photosensitive unit 50 is provided. And the relative positional relationship with the lock mechanism 15 (lock member 15A) provided in the main body case 10 that does not move with respect to the photoreceptor unit 50 changes. As a result, even if the detaching grip 51B is operated, the amount of operation of the lock mechanism 15 is reduced, and the lock cannot be released.

  More specifically, the lock member 15A can be swung forward by the operation of the detaching gripper 51B even when the photoconductor unit 50 is rotated, but the rocking amount (operation amount) of the lock member 15A is the photoconductor unit. Since it is small compared to when 50 is attached or detached (see FIG. 4), the retaining portion 15D cannot be completely retracted from above the rear support shaft 51D. Thereby, even if the gripping part 51B for separation is pulled upward, the retaining part 15D becomes an obstacle, and the rear support shaft 51D cannot be pulled out from the rear support groove 10D.

According to the above, the following effects can be obtained in the present embodiment.
The photoconductor unit 50 is rotatably supported by the main body case 10 around the rear support shaft 51D. When the photoconductor unit 50 is rotated upward, the paper jammed between the photoconductive drum 52 and the transport belt 63. The conveyor belt 63 is exposed so as to be removable. Thereby, without removing the photosensitive unit 50 from the main body case 10, it is possible to lift the photosensitive unit 50 with one hand and remove the jammed paper between the photosensitive drum 52 and the conveyor belt 63 with the other hand. Therefore, the jam processing can be easily performed.

  Since the photoconductor unit 50 includes a detachment grip 51B provided on the rear side and a rotation grip 51A provided on the front side, the photoconductor unit 50 can be easily attached and detached and rotated. It can be carried out. Further, since the lock mechanism 15 that prevents the photoconductor unit 50 from being detached from the main body case 10 and the lock release mechanism 55 that releases the lock by the lock mechanism 15 are provided, if the lock release mechanism 55 is not operated, the The body unit 50 cannot be detached from the main body case 10. Accordingly, it is possible to prevent the photoreceptor unit 50 from being unexpectedly detached from the main body case 10 especially when the photoreceptor unit 50 is rotated or during jam processing.

  Furthermore, in this embodiment, when the photosensitive unit 50 is rotated upward, the lock release mechanism 55 is operated by changing the relative positional relationship between the lock mechanism 15 and the lock release mechanism 55 due to the rotation. The amount of operation of the lock mechanism 15 is reduced so that the lock cannot be released. Thereby, it is possible to reliably prevent the photosensitive unit 50 from being unexpectedly detached from the main body case 10 when the photosensitive unit 50 is rotated or during jam processing.

  Since the unlocking mechanism 55 is provided with the release gripper 51 </ b> B for performing the releasing operation, the unlocking mechanism 55 can simultaneously perform the attaching / detaching operation of the photosensitive unit 50 while releasing the lock. Thereby, the operativity at the time of attachment / detachment (replacement) of the photoconductor unit 50 can be improved.

[Second Embodiment]
Next, a second embodiment of the present invention will be described in detail with reference to the drawings as appropriate. FIG. 7 is a schematic view showing the overall configuration of the color printer according to the second embodiment, FIG. 8A is a view showing a state where the engagement arm is detached from the photosensitive member case, and FIG. It is a figure which shows the state which the arm engaged with the photoreceptor case. In the present embodiment, since the configuration is added to the color printer 1 described above, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 7, the color printer 2 according to the second embodiment includes the above-described paper feeding unit 20 and the image forming unit 30 in the main body case 10, and further includes an example of a holding mechanism 80 and a jam sensor. A sheet detection sensor 91, an open / close detection sensor 92, and a control device 100.

As shown in FIGS. 8A and 8B, the holding mechanism 80 mainly includes an actuator 81 provided in the upper cover 11 and two engagement arms 82.
The actuator 81 switches the engagement arm 82 between the disengaged state shown in FIG. 8A and the engaged state shown in FIG. 8B with respect to the photoreceptor case 51 (flange 51F), and is driven. It is mainly composed of a mechanism 81A and a ball screw 81B.

The drive mechanism 81A is disposed substantially at the center in the upper cover 11, and although not shown, a drive source such as a motor that can rotate forward and reverse, and a drive force such as a gear that transmits the drive force from the drive source to the ball screw 81B. It is mainly composed of a transmission mechanism.
The ball screw 81B is disposed so as to extend in the left-right direction through the drive mechanism 81A, and is provided so as to be able to rotate forward and backward when a driving force is applied from the drive mechanism 81A. Male screws are formed at both ends of the ball screw 81B.

  The engagement arm 82 is disposed so as to face the photoreceptor unit 50 (photoreceptor case 51) in the left-right direction, and has a through-hole (reference numeral omitted) having a ball nut structure that engages with the male screw of the ball screw 81B at the upper end. And an engaging portion 82A extending inward in the left-right direction is provided at the lower end portion.

  In a normal state (before the paper jam occurs), the engagement arm 82 is disposed at a predetermined interval (disengaged) with respect to the photoreceptor case 51 as shown in FIG. When it occurs, as shown in FIG. 8B, the engaging portion 82A moves to a position where it engages with the flange 51F (engaged state). The flange 51F is a portion formed by bending the upper edge portions of the left and right side walls of the photoconductor case 51 substantially at right angles toward the outside in the left-right direction.

Returning to FIG. 7, the paper detection sensor 91 detects the jam of the paper between the photosensitive drum 52 and the belt by detecting the passage of the paper conveyed between the photosensitive drum 52 and the conveyance belt 63. This is a known sensor, and the detection result is output to the control device 100.
The opening / closing detection sensor 92 is a known sensor that detects opening / closing of the upper cover 11, and the detection result is output to the control device 100.

  The control device 100 is mainly composed of a CPU, RAM, ROM, input / output circuit and the like (not shown), and controls the actuator 81 based on programs and data stored in the ROM, outputs of the paper detection sensor 91 and the open / close detection sensor 92, and the like. By controlling, the state of the engagement arm 82 is controlled.

  Next, an operation at the time of jam processing of the color printer 2 configured as described above will be described. FIG. 9 is a flowchart for explaining processing in the control device, and FIG. 10 is a diagram showing a state in which the upper cover and the photoconductor unit are integrally rotated with respect to the main body case.

  As shown in FIG. 7, in the color printer 2, when image formation is started, paper is sent out from the paper supply unit 20 and a toner image is formed on the photosensitive drum 52, and the photosensitive drum 52 and the conveying belt 63 ( The toner images are sequentially transferred to the paper with the transfer roller 64). At this time, as shown in FIG. 9, if the paper detection sensor 91 does not detect the occurrence of paper jam (jam) (S1, No), the toner image on the paper is thermally fixed by the fixing unit 70, and the paper is The paper is discharged onto the paper discharge tray 12 and the image formation is completed.

  On the other hand, when the paper detection sensor 91 detects the occurrence of a jam (S1, Yes), the control device 100 stops the transport belt 63 (drive roller 61) and drives the actuator 81 (S2). As a result, the engagement arm 82 changes from the disengaged state shown in FIG. 8A to the engaged state shown in FIG. 8B.

  In this state, the user pivots the upper cover 11 upward to open as shown in FIG. At this time, since the engaging arm 82 (upper cover 11) is engaged with the flange 51F (photosensitive unit 50) of the photosensitive case 51, the photosensitive unit 50 is integrated with the upper cover 11 and the main body case 10. To turn. As a result, paper (not shown) jammed between the photosensitive drum 52 and the conveyor belt 63 can be removed from the opening provided in the upper portion of the main body case 10 by one operation (rotation operation of the upper cover 11). Can be exposed to the extent that removal is sufficiently possible.

  Although not shown, also in the color printer 2, the rear support shaft 51 </ b> D serving as the rotation shaft of the photosensitive unit 50 is disposed coaxially with the rotation shaft 11 </ b> A (see FIG. 1) of the upper cover 11. Therefore, the integral rotation of the upper cover 11 and the photosensitive unit 50 with respect to the main body case 10 can be performed satisfactorily. In addition, when the upper cover 11 is opened, the open / close detection sensor 92 outputs a signal indicating that the upper cover 11 has been opened to the control device 100.

  Next, after removing the exposed paper, the user rotates the upper cover 11 downward and closes it. At this stage (stage where the upper cover 11 is closed), a signal indicating that the upper cover 11 is closed is output from the open / close detection sensor 92 to the control device 100.

  When the control device 100 receives a signal that the upper cover 11 is opened and then receives a signal that the upper cover 11 is closed (S3, Yes), the paper detection sensor 91 detects the occurrence of a jam. (S4). If the control device 100 does not receive a signal that the upper cover 11 is closed after the upper cover 11 is opened (S3, No), it means that the jammed paper has not been removed. Therefore, the control device 100 returns to step S3 and returns to the upper cover. After 11 is opened, the operation is stopped until it is closed (becomes a standby state).

  If the paper detection sensor 91 does not detect the occurrence of a jam in step S4 (S4, No), the controller 100 drives the actuator 81 because the jammed paper has been removed (S5). Thus, the engagement arm 82 is changed from the engaged state shown in FIG. 8B to the disengaged state shown in FIG. When the paper detection sensor 91 detects the occurrence of a jam in step S4 (S4, Yes), it means that the jammed paper has not been completely removed. Therefore, the control device 100 returns to step S3 and performs processing. Do.

  After step S5 (or at the same time as step S5), the color printer 2 removes the untransferred toner image on the photosensitive drum 52 by a known configuration, and feeds a new sheet from the paper feeding unit 20 and also the photosensitive drum. A toner image is formed on 52 again. The toner images are sequentially transferred onto the paper between the photosensitive drum 52 and the conveying belt 63 (transfer roller 64), and the toner image on the paper is thermally fixed by the fixing unit 70, and then the paper is placed on the paper discharge tray 12. And the image formation is completed. In this process, when the paper detection sensor 91 detects the occurrence of a jam again (S1, Yes), the process proceeds to step S2, and the process is performed.

According to the above, the same effects as those of the first embodiment described above can be obtained, and the following effects can be further obtained in the present embodiment.
The color printer 2 includes a control device 100 that controls the actuator 81 based on the output of the paper detection sensor 91, and the control device 100 detects that the paper is jammed and the upper cover 11 and the photosensitive unit 50. Are engaged, and when the paper detection sensor 91 does not detect paper jam, the engagement is released.

  Accordingly, the photosensitive unit 50 can also be rotated upward by opening the upper cover 11, so that the paper jammed between the photosensitive drum 52 and the transport belt 63 can be performed by a single operation of opening the upper cover 11. Can be removed, and the jam processing can be performed more easily.

  Further, when the photoconductor unit 50 is rotated, the upper portion of the photoconductor case 51 is covered with the upper cover 11, so that the lock release mechanism 55 cannot be operated. Thereby, it is possible to reliably prevent the photosensitive unit 50 from being unexpectedly detached from the main body case 10 when the photosensitive unit 50 is rotated or during jam processing.

  In the present embodiment, since the engaging arm 82 is detached from the photoreceptor case 51 (see FIG. 8A) during normal time (before jam occurrence), the development cartridge 54 and the photoreceptor unit 50 are replaced. Sometimes, the replacement operation can be performed immediately without waiting for the movement of the engagement arm 82.

  Note that the state of the engagement arm 82 before the occurrence of a jam may be arbitrary. In this case, although not shown, a known position detection sensor for detecting the state (position) of the engagement arm 82 is provided in the main body case 10, and the detection result is output to the control device 100.

  Then, as shown in FIG. 11, when the paper detection sensor 91 detects the occurrence of a jam during image formation (S1, Yes), the control device 100 first checks the state (position) of the engagement arm 82. If it is in the detached state (see FIG. 8A) (S11, Yes), the conveyor belt 63 is stopped and the actuator 81 is driven (S2). On the other hand, when it is not in the disengaged state (S11, No) (when it is in the engaged state (see FIG. 8B)), the control device 100 proceeds to the above-described step S3 and performs processing.

  Thereafter, after the processing in steps S3 and S4 by the control device 100, the color printer 2 removes the untransferred toner image on the photosensitive drum 52 with a known configuration, and then performs a normal image forming operation. The Since the processing in steps S3 and S4 and the normal image forming operation are as described above, detailed description thereof is omitted.

  Here, even when the engagement arm 82 before the occurrence of the jam is set to the disengaged state, when the power supply is stopped or disconnected when the jam occurs and then restored, the engagement arm 82 is engaged. Therefore, a position detection sensor may be provided to check the state of the engagement arm 82 after jam detection (S1, Yes) (S11). In this case, step S5 described above is added after step S4 shown in FIG.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to above-described embodiment. About a concrete structure, it can change suitably in the range which does not deviate from the meaning of this invention.

  In the above-described embodiment, the configuration is shown in which the lock member 15A (lock mechanism 15) can be slightly swung by the operation of the detachable grip 51B (operation unit) even when the photosensitive unit 50 is rotated. The invention is not limited to this. For example, when the photosensitive unit is rotated by a predetermined amount or more, the lock mechanism may not be operated at all even if the operation unit of the lock release mechanism is operated. That is, in the present invention, “the operation amount is reduced” means that the operation amount of the lock mechanism becomes small when the operation unit of the unlock mechanism is operated with the photosensitive unit rotated by a predetermined amount or more, Including the case where the mechanism does not operate at all.

  As a configuration in which the lock mechanism does not operate at all when the photoconductor unit is rotated by a predetermined amount or more, for example, as shown in FIG. A configuration in which the moving direction of 55A is substantially parallel to the direction in which the inclined surface 15E of the lock member 15A extends can be exemplified. According to this, even if the release bar 55A is slid and moved when the photosensitive unit 50 is rotated, the release bar 55A and the inclined surface 15E do not come into contact with each other, so that the lock mechanism 15 can be prevented from operating.

  Further, the main body case may be provided with a configuration in which when the photosensitive unit is rotated upward by a predetermined amount or more, the rotation is engaged with the operation unit of the lock release mechanism, and the operation unit cannot be operated. . As a specific example, as shown in FIG. 12 (a), a through hole 55E is formed in the operation part (detachment gripping part 51B ′) of the unlocking mechanism 55, and the through hole of the rotated gripping part 51B ′ is rotated. A configuration in which a substantially L-shaped operation lock member 13 that can be engaged with 55E is provided behind the photoconductor unit 50 in the main body case 10 can be exemplified. According to this, as shown in FIG. 12B, when the photoreceptor unit 50 is rotated, the through-hole 55E of the detachable gripper 51B ′ and the operation lock member 13 are engaged. Even if it is going to operate 51B ', it cannot push forward, As a result, the locking mechanism 15 can be made not to operate.

  In the above-described embodiment, the configuration in which the operation portion of the lock release mechanism 55 is provided in the release gripping portion 51B is shown. However, the present invention is not limited to this, for example, the operation portion of the lock release mechanism is You may provide independently separately from a holding part.

  In the above-described embodiment, the rotation gripping portion 51A and the separation gripping portion 51B provided so as to protrude from the outer surface of the photoconductor case 51 are exemplified, but the present invention is not limited to this, and for example, the photoconductor case 51 It is good also considering the recessed part provided in the side wall of this as a holding part for rotation, or a holding part for detachment. Further, a substantially U-shaped handle extending upward from the upper end of the side wall of the photoconductor case 51 may be used as a gripping part for rotation or a gripping part for separation. The upper cover 11 may be provided with a grip for opening and closing.

  The configuration of the lock mechanism 15 and the lock release mechanism 55 shown in the above-described embodiment is an example, and the present invention is not limited to this. That is, the lock mechanism and the lock release mechanism can be changed as appropriate without departing from the spirit of the present invention as long as the lock mechanism 15 and the lock release mechanism 55 exhibit the same effects.

  Although not particularly described in the second embodiment described above, when the actuator 81 is driven and the engagement arm 82 is disengaged from the disengaged state when a jam occurs, the upper cover 11 is configured so that the engagement arm 82 is It is desirable to be configured or controlled so that it cannot be rotated (opened / closed) until it is engaged. According to this, it is possible to prevent the upper cover 11 from being rotated during the movement of the engagement arm 82, and thus it is possible to prevent damage to the actuator 81, the engagement arm 82, and the photoconductor unit 50. .

  The configuration of the actuator 81 and the holding mechanism 80 including the actuator 81 described in the second embodiment is an example, and the present invention is not limited to this. That is, the actuator and the holding mechanism can be appropriately changed without departing from the gist of the present invention as long as the actuator and the holding mechanism 80 have the same function as the actuator 81 and the holding mechanism 80 described above.

  In the above-described embodiment, the image forming apparatus (color printers 1 and 2) that exposes the surface of the photosensitive drum 52 with the light emitted from the LED unit 40 (LED head) is illustrated, but the present invention is limited to this. It is not a thing. That is, the present invention may be, for example, an image forming apparatus that exposes a photosensitive member with light emitted from an EL (electroluminescence) element or a phosphor, or light emitted from a laser light source (laser light). It may be an image forming apparatus that exposes the photoconductor.

  In the above-described embodiment, the color printers 1 and 2 are shown as an example of the image forming apparatus. However, the present invention is not limited to this, and may be, for example, a copying machine or a multifunction machine. In the above-described embodiment, the paper P such as a thick paper, a postcard, and a thin paper is shown as an example of the recording sheet. However, the present invention is not limited to this, and may be an OHP sheet, for example.

1 is a schematic diagram illustrating an overall configuration of a color printer as an example of an image forming apparatus. It is a figure which shows the structure of a photoconductor unit and a main body case. FIG. 3 is a sectional view taken along line III-III in FIG. 2. It is a figure which shows the state which opened the upper cover and operated the lock release mechanism. (A) is a figure which shows a mode that the photoconductor unit 50 is removed, (b) is a figure which shows the state which removed the photoconductor unit 50. (A) is a figure which shows the state which opened the upper cover and rotated the photoconductor unit, (b) is an enlarged view which shows the positional relationship of the lock member and lock release mechanism at the time of photoconductor unit rotation. It is the schematic which shows the whole structure of the color printer which concerns on 2nd Embodiment. (A) is a figure which shows the state which the engagement arm detach | leaved from the photoconductor case, (b) is a figure which shows the state which the engagement arm engaged with the photoconductor case. It is a flowchart explaining the process in a control apparatus. It is a figure which shows a mode that the upper cover and the photoreceptor unit were rotated integrally with respect to the main body case. It is a flowchart explaining the process in a control apparatus at the time of providing a position detection sensor. FIG. 8 is an enlarged view showing a configuration of a modified example in which an operation lock member is provided behind the photoconductor unit, and is a diagram showing a state before the photoconductor unit is rotated and a diagram after the photoconductor unit is rotated ( b).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Color printer 2 Color printer 10 Main body case 11 Upper cover 15 Lock mechanism 15A Lock member 50 Photoconductor unit 51 Photoconductor case 51A Rotation grip part 51B Detachment grip part 51D Rear support shaft 52 Photosensitive drum 55 Lock release mechanism 55A Release bar 63 Conveying belt 81 Actuator 82 Engaging arm 91 Paper detection sensor 100 Controller P Paper

Claims (4)

A main body case, a photoconductor unit detachably attached to the main body case, and a plurality of photoconductors arranged in parallel; an endless shape disposed below the plurality of photoconductors and facing the plurality of photoconductors An image forming apparatus comprising a belt and an upper cover that opens and closes an upper portion of the main body case,
The photoconductor unit includes a detachment grip provided at one end in a direction in which the plurality of photoconductors are arranged, and a rotation grip provided at the other end, and the main body centering on the one end The case is supported so that it can rotate,
Wherein the other end of the photosensitive unit is rotated upward, the one end portion in a state in which is supported by the body case, removably recording sheet jammed between the belt and the photoreceptor Configured to expose the belt ,
And a lock mechanism for locking the support on the one end side of the photoconductor unit by the main body case so that the photoconductor unit cannot be detached from the main body case, and a lock release for releasing the lock by the lock mechanism. With a mechanism,
When the unlock mechanism is operated to contact the lock mechanism and operate the lock mechanism by a predetermined amount in the unlocking direction, and rotate the photosensitive unit upward by a predetermined amount, The relative positional relationship between the lock mechanism and the lock release mechanism is changed by the rotation, so that the operation amount of the lock mechanism when operated is reduced and the lock cannot be released. An image forming apparatus. A main body case, a photoconductor unit detachably attached to the main body case, and a plurality of photoconductors arranged in parallel; an endless shape disposed below the plurality of photoconductors and facing the plurality of photoconductors An image forming apparatus comprising a belt and an upper cover that opens and closes an upper portion of the main body case,
The photoconductor unit includes a detachment grip provided at one end in a direction in which the plurality of photoconductors are arranged, and a rotation grip provided at the other end, and the main body centering on the one end The case is supported so that it can rotate,
Wherein the other end of the photosensitive unit is rotated upward, the one end portion in a state in which is supported by the body case, removably recording sheet jammed between the belt and the photoreceptor Configured to expose the belt ,
And a lock mechanism for locking the support on the one end side of the photoconductor unit by the main body case so that the photoconductor unit cannot be detached from the main body case, and a lock release for releasing the lock by the lock mechanism. With a mechanism,
A jam sensor for detecting clogging of a recording sheet between the belt and the photosensitive member, a state in which the upper cover and the photosensitive unit are engaged with each other so as to be integrally rotatable with respect to the main body case; An actuator that switches between the disengaged state and a control device that controls the actuator based on the output of the jam sensor;
The control device engages the upper cover and the photosensitive unit when the jam sensor detects a jam of the recording sheet, and engages the engagement when the jam sensor does not detect the jam of the recording sheet. image forming apparatus characterized by disengaging the. When the unlock mechanism is operated to contact the lock mechanism and operate the lock mechanism by a predetermined amount in the unlocking direction, and rotate the photosensitive unit upward by a predetermined amount, The relative positional relationship between the lock mechanism and the lock release mechanism is changed by the rotation, so that the operation amount of the lock mechanism when operated is reduced and the lock cannot be released. The image forming apparatus according to claim 2 . 4. The image forming apparatus according to claim 1 , wherein the unlocking mechanism includes an operation unit that performs a releasing operation in the gripping part for detachment. 5.

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