JP2003280309A - Image forming machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming machine which disables an intermediate transfer unit to separate from a specified loading position when an intermediate transfer body is not positioned at a standby position. <P>SOLUTION: The image forming machine is equipped with the intermediate transfer unit equipped with the intermediate transfer body transferring a toner image formed on a toner image formation body, and the intermediate transfer unit is equipped with an intermediate transfer body support mechanism, an intermediate transfer body contacting/leaving mechanism which moves the intermediate transfer body to an operation position where it comes into contact with the toner image formation body and the standby position where it leaves the toner image formation body, and a movement restricting mechanism which restricts the movement of the intermediate transfer unit, being positioned at the specified loading position, in the leaving direction. The movement restricting mechanism is equipped with a movement restricting member which operates interlocking with the intermediate transfer body contacting/leaving mechanism and is positioned at the movement restriction position where it engages a stopper provided on a machine body housing side when the intermediate transfer body is positioned at the operation position and at a movement allowing position where it does not engage the stopper when the intermediate transfer body is positioned at the standby position. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming machine such as a printer, a copying machine and a facsimile, and more particularly to an image forming machine provided with an intermediate transfer member.

[0002]

2. Description of the Related Art A full-color image forming machine is equipped with an intermediate transfer unit having an intermediate transfer body for sequentially transferring toner images formed on a toner image forming body by four color toners. The intermediate transfer unit is configured to be attachable / detachable to / from the machine housing to facilitate maintenance and inspection and jam handling. The intermediate transfer unit is positioned at a working position where the intermediate transfer body comes into contact with the toner image forming body while being mounted at a predetermined mounting position. on the other hand,
When removing the intermediate transfer unit from the predetermined mounting position, it is necessary to release the contact state between the intermediate transfer body and the toner image forming body, and move the intermediate transfer body to the retracted position away from the toner image forming body. After that, the intermediate transfer unit is removed from the mounting position.

[0003]

When the intermediate transfer unit is detached from the predetermined mounting position and the intermediate transfer unit is detached from the mounting position without performing the operation of positioning the intermediate transfer body at the retracted position, Since the intermediate transfer body moves while the intermediate transfer body and the toner image formation body are in contact with each other, there is a problem that the toner image formation body is damaged.

The present invention has been made in view of the above facts, and its main technical problem is not to position the intermediate transfer body at the retracted position when the intermediate transfer unit is separated from the predetermined mounting position. Another object of the present invention is to provide an image forming machine configured such that the intermediate transfer unit cannot be removed from the mounting position.

[0005]

In order to solve the above-mentioned main technical problems, according to the present invention, a toner image forming member rotatably disposed in a machine housing and the toner image forming member formed on the toner image forming member. In an image forming machine including an intermediate transfer unit having an intermediate transfer body for transferring the toner image, the intermediate transfer unit being configured to be attachable / detachable in / from the machine housing, the intermediate transfer unit An intermediate transfer member supporting mechanism that rotatably supports the body, an operating position that brings the intermediate transfer member into contact with the toner image forming member in a state where the intermediate transfer unit is positioned at a predetermined mounting position, and the toner image forming member. An intermediate transfer member contacting / separating mechanism that operates in a retracted position away from the intermediate transfer unit, and restricts movement of the intermediate transfer unit in the detaching direction with the intermediate transfer unit positioned at a predetermined mounting position. A movement regulating mechanism for operating the intermediate transfer body, the movement regulating mechanism operating in conjunction with the intermediate transfer body contacting / separating mechanism, and positioning the intermediate transfer body at the working position. When it is located at a movement restricting position that engages with a stopper provided on the body housing side,
Provided is an image forming machine, wherein the intermediate transfer member contacting / separating mechanism includes a movement restricting member that is positioned at a movement permitting position that does not engage with the stopper when the intermediate transfer member is positioned at the retracted position. To be done.

The inter-transfer member contacting / separating mechanism is provided with an operation lever that can be operated between a separation restriction position for operating the intermediate transfer member to the operating position and a separation allowing position for operating the intermediate transfer member to the retracted position. It is desirable that the intermediate transfer unit is provided with an operation lever restriction mechanism that restricts the operation of the operation lever when the operation lever is positioned at the disengagement allowable position. Further, the intermediate transfer unit includes a lock mechanism that locks the operation of the operation lever restricting mechanism while the operation lever restricting mechanism restricts the operation of the operation lever. When it is positioned at the mounting position, it is desirable to contact the operating member provided on the body housing to release the lock. Furthermore, it is desirable that the intermediate transfer member contact / separation mechanism be configured to move the intermediate transfer member from the operating position to a retracted position obliquely downward.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of an image forming machine constructed according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic sectional view of a color laser beam printer as an image forming machine constructed according to the present invention. The illustrated color laser beam printer includes a rectangular parallelepiped housing 2 made of synthetic resin. A photosensitive drum 3 as a toner image forming member is rotatably disposed in the body housing 2 at a substantially central portion of the body housing 2. The photoconductor drum 3 is rotationally driven by a gear transmission (not shown) in the direction indicated by an arrow through a charging area, an electrostatic latent image forming area, a developing area, an image transfer area, and a cleaning area in order. Around this photosensitive drum 3, a charging corona discharger 4 configured according to the present invention in a charging area, a developing device 5 in a developing area, an intermediate transfer body 6 as a toner image forming body in an image transfer area, and cleaning. Cleaning mechanisms 7 for the photosensitive drums are provided in the respective areas. A cleaning mechanism 8 for the intermediate transfer body 6 is arranged at the lower left of the intermediate transfer body 6 in FIG. The developing device 5 is
The illustrated embodiment includes a yellow toner developing unit 5a, a magenta toner developing unit 5b, a cyan toner developing unit 5c, and a black toner developing unit 5d.

A laser unit 9 as an electrostatic latent image forming means is arranged in the upper portion of the housing 2.
The laser unit 9 projects laser light based on image information output from a computer, for example, on the peripheral surface of the photosensitive drum 3 in the electrostatic latent image forming area between the charging area and the developing area. In addition, in the lower part of the body housing 2,
A secondary transfer roller 10 is disposed below the intermediate transfer body 6, and a conveyor belt mechanism 11 and a fixing unit 12 are disposed downstream of the secondary transfer roller 10 (left side in FIG. 1). ing.

Next, the operation of the above laser beam printer will be briefly described. While the photosensitive drum 3 is rotated in the direction shown by the arrow, the corona discharger 4 for charging charges the photosensitive layer of the photosensitive drum 3 to a specific polarity. Then, in the electrostatic latent image forming area between the charging area where the corona discharger 4 for charging is arranged and the developing area where the developing device 5 is arranged, laser light is emitted from the laser unit 9 onto the photosensitive drum 3. An electrostatic latent image corresponding to image information is formed on the peripheral surface of the photosensitive drum 3 by being projected. Thereafter, the developing device 5 causes the toner to act on the electrostatic latent image on the photoconductor drum 3 to visualize the electrostatic latent image. The toner image thus formed on the photosensitive drum 3 is transferred to the intermediate transfer body 6 as a toner image forming body. In the case of color printing, charging of the photosensitive drum 3 by the corona discharger 4 for each color, exposure by the laser unit 9, development unit 5a for yellow toner, development unit 5b for magenta toner, and development for cyan toner are performed for each color. Development is performed by the unit 5c and the black toner developing unit 5d, and the image is transferred to the intermediate transfer body 6 each time. This allows
A multicolor toner image corresponding to one image signal is transferred onto the intermediate transfer member 6.

On the other hand, the sheet P fed from a sheet feeding device (not shown) is temporarily stopped by a pair of registration rollers (not shown),
The intermediate transfer body 6 and the secondary transfer roller 10 are timed with the intermediate transfer body 6 to which the toner image is transferred as described above.
And are conveyed to the opposite secondary transfer area. The toner image formed on the peripheral surface of the intermediate transfer body 6 is transferred to the surface of the paper P conveyed to the secondary transfer area by the action of the transfer roller 10. The paper P on which the toner image has been transferred is peeled off from the intermediate transfer body 6 and is transported to the fixing unit 12 by the transport belt mechanism 11, where the toner image is heated and fixed on the surface of the paper, and then discharged to the outside of the housing 2. To be done.

The residual toner adhering to the surface of the photosensitive drum 3 after the toner image is transferred from the photosensitive drum 3 to the intermediate transfer member 6 as described above is cleaned by the cleaning mechanism 7.
Removed by. On the other hand, the residual toner adhering to the surface of the intermediate transfer body 6 after the toner image is transferred from the intermediate transfer body 6 to the paper P is removed by the cleaning mechanism 8.

In the above-mentioned image forming machine, the photosensitive drum 3, the corona discharger 4 for charging, and the developing device 5 in the developing area.
Also, the cleaning mechanism 7 for the photosensitive drum is integrally configured as a process unit. Further, an intermediate transfer member 6 and an intermediate transfer member contacting / separating mechanism, which will be described later, that contacts or retracts the intermediate transfer member 6 with respect to the photosensitive drum 3 are integrally configured as an intermediate transfer unit. Furthermore,
The secondary transfer roller 10 and the transport belt mechanism 11 are also integrally configured as a transfer transport unit. The process unit, the intermediate transfer unit, the transfer / conveyance unit, and the fixing unit 12 are mounted from the front side along the guide members provided in the machine housing 2.
It is configured to be detachable. FIG. 2 shows a state in which the front cover 2a disposed on the front side surface of the machine housing 2 in the image forming machine is opened, and the process unit 20 and the intermediate transfer unit described above are provided in the machine housing 2. 30, transfer transport unit 21 and fixing unit 1
2 is inserted and stored from the front side. Further, FIG. 3 shows a state in which the transfer / transport unit 21, the fixing unit 12, and the intermediate transfer unit 30 are pulled out from the predetermined mounting position shown in FIG. 2 to the front side.

The intermediate transfer unit 30 will be described below with reference to FIG.
It will be described with reference to FIGS. Intermediate transfer unit 30
4 has a unit case 31 as shown in FIG. 4, and the intermediate transfer body 6 is rotatably disposed in the unit case 31. A front cover 32 is mounted on the front side (lower left side in FIG. 4) of the unit case 31, and a rear cover 33 is mounted on the rear side (upper right side in FIG. 4). FIG. 6 shows a plan view of an intermediate transfer member support mechanism 40 that rotatably supports the intermediate transfer member 6. The rotation shaft 6 a of the intermediate transfer member 6 is provided in the unit case 31.
Are rotatably supported by support levers 41 and 41 mounted on the front side plate 311 and the rear side plate 312, respectively, via bearings 42 and 42. The rotary shaft 6a is provided with intermediate transfer member position restricting members 6b and 6b inside the front plate 311 and the rear plate 312, respectively. The intermediate transfer member position restricting member 6b is formed in a fan shape as shown in FIG. The intermediate transfer member 6
4, a driven gear 6c is mounted on the right end in FIG. 4, and this driven gear 6c is adapted to be transmission-coupled to a gear transmission (not shown).

Here, the front side plate 311 and the rear side plate 312 are provided.
The relationship between the support levers 41 and 41 will be described with reference to FIG. The front side plate 311 and the rear side plate 3
Since the 12 and the support levers 41 and 41 have substantially the same configuration, the front plate 311 and the support lever 41 attached thereto will be described. One end of the support lever 41 is swingably supported by the front side plate 311 by a support shaft 43, and an intermediate portion thereof rotatably supports the rotary shaft 6 a of the intermediate transfer member 6 via a bearing 42. . Therefore, when the support lever 41 swings around the support shaft 43, the intermediate transfer body 6 supported by the intermediate portion of the support lever 41 is brought into contact with the photosensitive drum 3. It is operated in the retracted position away from 3. In the illustrated embodiment, the support shaft 43 of the support lever 41 is arranged on a line that is substantially perpendicular to the line connecting the rotation shaft of the photoconductor drum 3 and the rotation shaft 6a of the intermediate transfer member 6 at a diagonally lower side. It is set up. With this configuration, the separation distance between the photosensitive drum 3 and the intermediate transfer body 6 can be set to the maximum range with respect to the swing amount of the support lever 41.

As described above, in order to allow the movement of the rotary shaft 6a of the intermediate transfer member 6 by the swing of the support lever 41 about the support shaft 43, the front side plate 311 is provided with an elongated hole 311a.
Are formed. The support lever 41 has a support shaft 4
3, a non-guide groove 411 is formed so that the support lever 41 is guided to swing by fitting the non-guide groove 411 into a guide pin 313 attached to the front side plate 311. . Further, a spring locking portion 412 is provided at an intermediate portion of the support lever 41, and the spring locking portion 412 and the spring locking portion 31 provided on the front side plate 311 are provided.
A tension coil spring 44 is stretched between 1b and 1b. Therefore, the support lever 41 is connected to the tension coil spring 4
The spring force of 4 urges the support shaft 43 to rotate counterclockwise in FIG. At the other end of the support lever 41, an actuated portion 413 on which an intermediate transfer member contact / separation mechanism 50, which will be described later, acts is provided.

The intermediate transfer unit 30 in the illustrated embodiment has the intermediate transfer body 6 shown in FIG. 7 in a state where it is positioned at a predetermined mounting position of the machine body housing 2.
There is provided an intermediate transfer member contact / separation mechanism 50 which is operated to a working position where the intermediate transfer member is brought into contact with and a retracted position where the intermediate transfer member is separated from the photosensitive drum 3. The intermediate transfer member contacting / separating mechanism 50 includes an actuating cam 51 having a cam surface 511 that comes into contact with an actuated portion 413 provided at the other end of the support lever 41. The operating cam 51 is made of an appropriate synthetic resin, and the driven gear 52 is integrally formed. The operating cam 51 is mounted on an operating shaft 53 rotatably supported by a front side plate 311 and a rear side plate 312, as shown in FIG. Driven gear 52 integrally formed with operation cam 51
Engages with a drive gear 54 rotatably mounted on a support shaft 314 mounted on the front side plate 311. The boss 541 of the drive gear 54 is provided with an engagement protrusion 415a that protrudes in the radial direction. The intermediate transfer member contacting / separating mechanism 50 in the illustrated embodiment includes an operation lever 55 mounted on the front cover 32 and operating the drive gear 54, as shown in FIG. The operation lever 55 has a connecting portion 55 at the upper end that fits with the boss 541 of the drive gear 54.
1 is provided. This operation lever 55 is used for the front cover 3
The connecting portion 551 is arranged on the front side of the second concave portion 321 and the connecting portion 551 is inserted through a hole (not shown) provided in the wall of the concave portion 321 to be fitted with the boss 541 of the drive gear 54. It is configured such that it can be operated between a separation regulation position in which the intermediate transfer body 6 is operated to the operating position and a separation allowable position in which the intermediate transfer body 6 is operated to the retracted position. A movement restricting member 60 is attached to the operation shaft 53 at a position inside the front side plate 311 as shown in FIG. This movement restriction member 6
Since 0 is attached to the actuation shaft 53 to which the actuation cam 51 is attached, 0 is actuated in conjunction with the actuation of the actuation cam 51.

FIGS. 8 and 9 show a state in which the front cover 32 is removed and the operation lever 55 is connected to the boss 541 of the drive gear 54 in order to facilitate understanding of the intermediate transfer member contacting / separating mechanism 50. ing. FIG. 8 shows the intermediate transfer unit 30.
Shows a state in which the intermediate transfer member 6 is positioned at a predetermined mounting position of the machine housing 2 and the intermediate transfer member 6 is positioned at an operating position where the intermediate transfer member 6 contacts the photosensitive drum 3. At this time, the outer peripheral surface of the intermediate transfer body position regulating member 6b attached to the rotary shaft 6a of the intermediate transfer body 6 contacts the stopper roller 20a provided in the process unit 20. In a state where the intermediate transfer unit 30 shown in FIG. 8 is positioned at a predetermined mounting position of the machine housing 2 and the intermediate transfer body 6 is positioned at a working position where the intermediate transfer body 6 comes into contact with the photosensitive drum 3, the operation lever 55 is restricted from being shown in the drawing. Position (stopper 3 provided on the front cover 32 as indicated by a chain double-dashed line in FIG. 5)
23), and at this time, the movement restricting member 60 attached to the operating shaft 53.
Is positioned at a movement restricting position where it engages with a stopper 2e provided on the body housing 2 side. As a result, when the intermediate transfer unit 30 is pulled out toward the front side, the movement restricting member 60 engages with the stopper 2e provided on the machine housing 2 side to restrict the movement thereof. Therefore,
The movement restricting member 60 attached to the operating shaft 53 is
It operates in conjunction with the intermediate transfer member contacting / separating mechanism 50, and functions as a movement restricting mechanism that restricts the movement in the separating direction when the intermediate transfer unit 30 is positioned at a predetermined mounting position.

In the illustrated embodiment, the operation lever 55 is configured to selectively restrict the swing toward the separation restriction position side at the intermediate position shown by the solid line in FIG. That is, the operation lever 55 is attached to the front cover 32 as shown in FIG.
There is provided a hole (not shown) into / from which the stopper pin 62 abutting at the intermediate position indicated by the solid line can be inserted and removed. Therefore, when the stopper pin 62 is inserted into a hole (not shown) as shown in FIG. 5, the operation lever 55 is restricted from swinging at the intermediate position shown by the solid line in FIG. At this time,
The intermediate transfer body 6 is positioned closer to the mounting position side than the operating position, and is slightly separated from the photosensitive drum 3. In this state, the movement restricting member 60 is in a position to engage with the stopper 2e. In this way, the stopper pin 62 is inserted into the removable hole and the operation lever 55 is positioned at the intermediate position shown by the solid line in FIG. 5 when the image forming machine is shipped from the factory. As a result, it is possible to solve the problem caused by the contact between the intermediate transfer member 6 and the photosensitive drum 3 for a long period of time from the factory shipment of the image forming machine to the actual use thereof. The stopper pin 6
2 is taken out by the image forming machine when it is unpacked.

As shown in FIG. 8, the intermediate transfer unit 30 is positioned at a predetermined mounting position of the machine housing 2 and the intermediate transfer body 6 is positioned at a working position where the intermediate transfer unit 6 contacts the photosensitive drum 3. When pulling out from the predetermined mounting position of the machine body housing 2, first, the operation lever 55 is rotated clockwise about the support shaft 314 as shown by the arrow in FIG. Therefore, the drive gear 5 connected to the connecting portion 551 of the operation lever 55
4 rotates clockwise about the support shaft 314 as shown by the arrow in FIG. 9, and the driven gear 52 meshing with this drive gear 54 is centered around the operating shaft 53 as shown by the arrow in FIG. It can be rotated counterclockwise. As a result, the operating cam 51, which is formed integrally with the driven gear 52, also moves the operating shaft 5 as shown by the arrow in FIG.
Since it rotates counterclockwise about 3, the support lever 41 having the actuated portion 413 that comes into contact with the cam surface 511 of the actuating cam 51 moves clockwise about the support shaft 43 as indicated by the arrow in FIG. Rotate in the direction. Support lever 4
When 1 is swung to the position shown in FIG. 9, the intermediate transfer member 6 supported by the support lever 41 is positioned at the retracted position separated from the photosensitive drum 3 as shown in FIG. At this time,
The intermediate transfer member position regulating member 6b attached to the rotating shaft 6a of the intermediate transfer member 6 is also separated from the stopper roller 20a provided in the process unit 20.

In the illustrated embodiment, since the direction in which the intermediate transfer body 6 is separated from the photosensitive drum 3 by the swing of the support lever 41 is the diagonally lower right direction in FIG. It is possible to avoid interference with the like, and it can be housed in the machine body housing 2. That is, if the intermediate transfer member 6 is configured to be separated downward, it is necessary to take measures to avoid interference with the transfer device such as the transfer roller 10, and the intermediate transfer member 6 is configured to be separated laterally. There is a problem that the width dimension of the housing 2 increases. However, in the illustrated embodiment, the intermediate transfer member 6 is separated from the photosensitive drum 3 in the diagonally lower right direction, so that the above-mentioned problem is solved.

As described above, in order to position the intermediate transfer member 6 at the retracted position where it is separated from the photosensitive drum 3, first, when the operation lever 55 is moved to the disengagement allowable position shown in FIG. 9, it is attached to the operation shaft 53. The movement restricting member 60 rotating in the counterclockwise direction about the operating shaft 53,
It is positioned at a movement permitting position where it does not engage with a stopper 2e provided on the body housing 2 side. Thus, by positioning the intermediate transfer body 6 at the retracted position, the intermediate transfer unit 30 can be pulled out from the machine housing 2, and the intermediate transfer unit 30 can be pulled out from the machine housing 2 with the intermediate transfer body 6 in the operating position. It is possible to prevent damage to the photoconductor drum 3 caused thereby.

In the intermediate transfer unit 30 in the illustrated embodiment, an operation for controlling the operation of the operation lever 55 is performed in a state where the operation lever 55 having the intermediate transfer body 6 shown in FIG. A lever regulation mechanism 70 is provided. This operation lever regulation mechanism 70
Are arranged on the front cover 32 (see FIG. 5). Hereinafter, FIG. 10 and FIG.
This will be described with reference to FIG. In the operation lever regulating mechanism 70 in the illustrated embodiment, a lever regulating member 71 having an intermediate portion rotatably supported by a supporting pin 322 provided horizontally on the front cover 32, and a supporting pin for the lever regulating member 71. A compression coil spring 72 for urging to rotate clockwise around 322 in the drawing is provided. The lever restricting member 71 is provided on the left side of the support pin 322 in the drawing, and a locking surface 711 that engages with the operating lever 55 in the operation restriction state shown in FIG. 11, and the support pin 32 from the upper end of the locking surface 711.
An operation guide surface 712 that is inclined downward in the direction 2;
It is provided with a manual operation portion 713 that projects leftward in the drawing from the lower end of the locking surface 711, and an engagement portion 714 that projects from the support pin 322 to the right side in the drawing and that engages with a lock mechanism described later. The lever restricting member 71 configured in this way is supported by the compression coil spring 72.
It is urged to rotate clockwise around 22 in the figure, and a part of the manual operation portion 713 abuts the stopper portion 312 provided on the front cover 32 at the position shown by the solid line in the figure, and the rotation thereof Is regulated.

Next, the operation of the operation lever regulating mechanism 70 will be described. In FIG. 10, the solid line shows a state in which the intermediate transfer unit 30 is positioned at a predetermined mounting position of the machine housing 2 and the intermediate transfer member 6 is positioned at the operating position shown in FIG. When the intermediate transfer unit 30 is pulled out from the predetermined mounting position of the machine housing 2 from the state where the intermediate transfer body 6 is positioned at the operating position, the operation lever 55 is moved from the separation restriction position shown by the solid line in FIG. 10 to the support shaft 314. Rotate clockwise around the center. When the operation lever 55 is rotated about the support shaft 314 in the clockwise direction in FIG. 10, the lower end of the operation lever 55 is at the lower end of the operation guide surface 7 of the lever regulating member 71, as indicated by a two-dot chain line.
The lever regulating member 71 rotates counterclockwise about the support shaft 314 against the spring force of the compression coil spring 72, because the lever regulating member 71 rotates while abutting on 12. And the operating lever 5
When 5 is further rotated in the clockwise direction in FIG. 10 about the support shaft 314, the lower end thereof is disengaged from the operation guide surface 712, so that the lever regulating member 71 is centered on the support shaft 314 by the spring force of the compression coil spring 72. In the clockwise direction, as shown in FIG.
The lower end of 5 is located at the disengagement allowable position on the left side of the locking surface 711 in the drawing. As a result, the intermediate transfer unit 30 is positioned at the retracted position shown in FIG. 9 as described above, and the movement restricting member 60 attached to the actuating shaft 53 as described above is a stopper provided on the machine housing 2 side. It is positioned at a movement permitting position where it does not engage with 2e. When the operation lever 55 is positioned at the disengagement allowable position shown in FIG. 11, the lever regulating member 71 is placed.
The rotation of the intermediate transfer body 6 in the retracted position is restricted by the locking surface 711 of the support shaft 314 in the counterclockwise direction about the support shaft 314 and in the direction of the separation regulation position that positions the intermediate transfer body 6 in the operating position. The state is maintained. in this way,
By pulling out the intermediate transfer unit 30 from the machine housing 2 while holding the intermediate transfer body 6 in the retracted position,
The photoconductor drum 3 can be removed without damaging it.

The intermediate transfer unit 30 in the illustrated embodiment comprises a lever regulating member 71 for regulating the operation of the operating lever 55 at the disengagement allowance position shown in FIG. 11, and a lock mechanism 80 for locking the operation in the regulated state. is doing.
Hereinafter, the lock mechanism 80 will be described with reference to FIGS. 10 to 13. The locking mechanism 80 in the illustrated embodiment
Is equipped with a lock lever 81 having a support shaft 811 in the middle thereof. The lock lever 81 has a lock portion 8 which is engaged at one end with the engagement portion 714 of the operation restricting member 71.
12 is provided, and the operation protrusion 81 is provided at the other end.
3 is provided. The lock lever 81 configured as described above is arranged in a direction in which the support shaft 811 is orthogonal to the support pin 322 of the operation restricting member 71, and the front cover 32 is provided.
It is rotatably supported by. In the illustrated embodiment, the lock mechanism 80 includes an operating protrusion 813 of the lock lever 81.
And a front cover 32, a compression coil spring 82 for urging the lock lever 81 to rotate counterclockwise in FIGS. 12 and 13 about the support shaft 811 is provided. The lock lever 81 rotated by the spring force of the compression coil spring 82 has a lock portion 812 shown in FIG.
In the lock position shown by (7), it abuts on the stopper surface 715 provided on the engaging portion 714 of the lever regulating member 71.
On the other hand, the operating protrusion 813 of the lock lever 81 contacts the operating member 2f provided on the body housing 2 side when the intermediate transfer unit 30 is positioned at the predetermined mounting position of the body housing 2, and as shown in FIG. It rotates clockwise against the spring force of the compression coil spring 82. As a result,
The lock portion 812 of the lock lever 81 and the lever regulating member 7
The engagement with the first engaging portion 714 is released.

Next, the operation of the lock mechanism 80 will be described. In a state where the intermediate transfer unit 30 is positioned at a predetermined mounting position of the machine body housing 2, FIG.
As shown in FIG. 2, the lock portion 812 of the lock lever 81 and the engaging portion 714 of the lever regulating member 71 are released from each other, so that the manual operating portion 713 of the lever regulating member 71 is moved downward as shown in FIG. Lever regulating member 7 by pushing
1 is rotated counterclockwise about the support shaft 314 against the spring force of the compression coil spring 72 as shown by the chain double-dashed line. As a result, the engagement state between the lower end of the operating lever 55 and the locking surface 711 of the lever restricting member 71 is released, and the operating lever 55 can be operated to the disengagement restricting position shown by the solid line in FIG. The transfer body 6 can be positioned at the working position.

The intermediate transfer unit 30 is attached to the machine housing 2
When the control lever 55 is pulled out from the state in which it is positioned at the predetermined mounting position, as described above, the operating lever 55 is rotated clockwise about the support shaft 314 from the position indicated by the solid line in FIG. At this time, the lock lever 81
Locking portion 812 and the engaging portion 714 of the lever regulating member 71
Since the engagement with is released, the operation lever 55 can be positioned at the disengagement allowable position shown in FIG. 11 as described above. As a result, the intermediate transfer unit 30 is positioned at the retracted position as described above, and the movement restricting member 60 attached to the operating shaft 53 as described above is provided on the stopper 2e provided on the machine housing 2 side.
It is positioned at a movement permitting position that does not engage with. And
When the intermediate transfer unit 30 is pulled out from the machine housing 2 with the intermediate transfer body 6 held in the retracted position, the lock lever 81 moves counterclockwise in FIGS. 12 and 13 about the support shaft 811 by the spring force of the compression coil spring 82. The lever regulating member 71 is rotated, and as shown in FIG.
Is positioned at the lock position located above the engaging portion 714 of the. As a result, when the intermediate transfer unit 30 is pulled out from the predetermined mounting position of the machine body housing 2, the operation of the lever restricting member 71 is restricted and the operation lever 55 is positioned at the disengagement allowable position shown in FIG. Since the operation is restricted in this state, the intermediate transfer body 6 is held at the retracted position. Therefore, when the intermediate transfer unit 30 is next mounted in the predetermined mounting position of the machine housing 2, the photosensitive drum 3 is not damaged.

[0028]

The image forming apparatus according to the present invention is provided with a movement restricting mechanism for restricting the movement of the intermediate transfer unit in the detaching direction when the intermediate transfer unit is positioned at the predetermined mounting position. The regulating mechanism operates in conjunction with the intermediary transfer member contact / separation mechanism, and when the intermediary transfer member contact / separation mechanism positions the intermediary transfer member at the operating position, it is in the movement restricting position that engages with the stopper provided on the machine housing side. Since the intermediate transfer member contacting / separating mechanism is provided with a movement restricting member that is positioned at a movement permitting position that does not engage the stopper when the intermediate transfer member contact / separation mechanism is positioned at the retracted position, by positioning the intermediate transfer member at the retracted position. It is possible to pull out the intermediate transfer unit from the machine housing. Therefore, it is possible to prevent damage to the photoconductor drum 3 caused by pulling out the intermediate transfer unit from the machine housing with the intermediate transfer body in the operating position.

[Brief description of drawings]

FIG. 1 is a schematic configuration sectional view of a laser beam printer as an image forming machine configured according to the present invention.

FIG. 2 is a perspective view showing a state in which a front cover of the image forming machine shown in FIG. 1 is opened.

FIG. 3 is a perspective view showing a state in which an intermediate transfer unit, a transfer conveyance unit and a fixing unit of the image forming machine shown in FIG. 1 are drawn out.

4 is a perspective view of an intermediate transfer unit equipped in the image forming machine shown in FIG.

5 is a side view of the intermediate transfer unit shown in FIG.

6 is a plan view showing an intermediate transfer member support mechanism that constitutes the intermediate transfer unit shown in FIG.

7 is a side view showing a state in which an operation lever is removed in an intermediate transfer member contacting / separating mechanism that constitutes the intermediate transfer unit shown in FIG.

8 is a side view showing a state in which an intermediate transfer member in the intermediate transfer member contact / separation mechanism constituting the intermediate transfer unit shown in FIG. 4 is positioned at an operation position.

9 is a side view showing a state in which the intermediate transfer body in the intermediate transfer body contacting / separating mechanism constituting the intermediate transfer unit shown in FIG. 4 is positioned at the retracted position.

FIG. 10 is a side view showing a state of a separation regulation position in an operation lever regulation mechanism equipped in the intermediate transfer unit shown in FIG.

11 is a side view showing a state of a disengagement allowable position in an operation lever regulating mechanism provided in the intermediate transfer unit shown in FIG.

12 is a side view showing a locked state of a lock mechanism provided in the intermediate transfer unit shown in FIG.

13 is a side view showing an unlocked state of a lock mechanism provided in the intermediate transfer unit shown in FIG.

[Explanation of symbols]

2: Housing of image forming machine 3: Photosensitive drum 4: Corona discharger for charging 5: Developing device 5a: Developing unit for yellow toner 5b: Development unit for magenta 5c: Developing unit for cyan toner 5d: Developing unit for black toner 6: Intermediate transfer body 7: Cleaning mechanism for photoconductor drum 8: Cleaning mechanism for intermediate transfer member 9: Laser unit 10: Secondary transfer roller 11: Conveyor belt mechanism 12: Fixing unit 20: Process unit 21: Transfer transport unit 30: Intermediate transfer unit 31: Unit case 32: Front cover 33: Rear cover 40: Intermediate transfer member support mechanism 41: Support lever 43: Bearing 43: Support shaft 50: Intermediate transfer member contact / separation mechanism 51: Actuating cam 52: Driven gear 53: Working axis 54: Drive gear 55: Operation lever 60: Movement restriction member 70: Control lever control mechanism 71: Lever regulating member 72: compression coil spring 80: Lock mechanism 81: Lock lever 82: Compression coil spring

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2H171 FA02 FA03 FA10 GA09 JA03                       JA48 JA52 KA05 KA10 KA18                       KA23 KA25 KA27 QA02 QA23                       QB02 QB15 QB33 QC03 QC04                       QC23 WA02 WA03 WA17 WA21                       WA23                 2H200 FA09 GA23 GA44 GA47 GB12                       HA03 HA12 HB03 HB12 HB22                       JA02 JC02 LA03 LA12 LA18                       LA24 LA38

Claims (4)

[Claims] 1. An intermediate transfer unit comprising: a toner image forming member rotatably disposed in a machine housing; and an intermediate transfer member for transferring a toner image formed on the toner image forming member. In an image forming machine in which the intermediate transfer unit is configured to be attachable / detachable in a machine housing, the intermediate transfer unit includes an intermediate transfer body supporting mechanism that rotatably supports the intermediate transfer body, and the intermediate transfer unit has a predetermined structure. And an intermediate transfer member contacting / separating mechanism for operating the intermediate transfer member in a retracted position separated from the toner image forming member, and an operating position for bringing the intermediate transfer member into contact with the toner image forming member. A movement restricting mechanism for restricting the movement of the intermediate transfer unit in the detaching direction in a state where the intermediate transfer body is positioned at a predetermined mounting position. The intermediary transfer member contacting / separating mechanism operates in conjunction with a separating mechanism and is positioned at a movement restricting position that engages with a stopper provided on the body housing side when the intermediate transfer member is positioned at the operating position. An image forming machine, wherein the intermediate transfer member contact / separation mechanism includes a movement restricting member that is positioned at a movement permitting position that does not engage with the stopper when the intermediate transfer member is positioned at the retracted position. 2. An operating lever operable by the intermediate transfer member contacting / separating mechanism to a separation restriction position for operating the intermediate transfer member to the operating position and a separation allowable position for operating the intermediate transfer member to the retracted position. The image forming apparatus according to claim 1, wherein the intermediate transfer unit includes an operation lever restricting mechanism that restricts the operation of the operation lever when the operation lever is positioned at the disengagement allowable position. 3. The intermediate transfer unit comprises a lock mechanism for locking the operation of the operation lever restricting mechanism in a state where the operation lever restricting mechanism restricts the operation of the operation lever, and the lock mechanism comprises: The image forming machine according to claim 2, wherein when the intermediate transfer unit is positioned at the mounting position of the machine body housing, the intermediate transfer unit abuts an operating member provided on the machine body housing to release the lock. 4. The intermediate transfer member contacting / separating mechanism operates the intermediate transfer member from the operating position to a retracted position obliquely below.
The image forming machine according to claim 1.