JP2023128894A - Image forming apparatus - Google Patents

Abstract

To provide an image forming apparatus that reduces the size of a mechanism for controlling contact and separation of a developing roller and drive and stop of the developing roller.SOLUTION: An image forming apparatus comprises: a cam follower 110 that can make slide movement; a switching lever 140; and a linear motion plate 200 that can linearly move fore and aft between a first position and a second position. When the linear motion plate 200 is located at the first position, the cam follower 110 is located at a pressing position where it presses a developing cartridge to locate the developing cartridge at a separation position where a developing roller is separated from a photoconductor drum, and the switching lever 140 is located at a cut-off position where a driving force from a motor is not transmitted to the developing roller. When the linear motion plate 200 is located at the second position, the cam follower 110 is located at a non-pressing position where it locates the developing cartridge at a contact position where the developing roller is in contact with the photoconductor drum, and the switching lever 140 is located at a transmission position where the driving force from the motor can be transmitted to the developing roller.SELECTED DRAWING: Figure 11

Description

The present invention relates to an image forming apparatus including a photosensitive drum and a developing roller.

Conventionally, image forming apparatuses are known that include a photosensitive drum, a developing cartridge having a developing roller, a rotating cam, and a cam follower that can be slid in the direction of the rotational axis of the developing roller by rotation of the cam. Patent Document 1). In this technology, by rotating a cam and sliding a cam follower, the cam follower presses the developer cartridge, thereby moving the developer roller from a position where it contacts the photosensitive drum to a position where it is separated from the photosensitive drum. There is.

In addition, this technology includes a clutch that has a planetary gear mechanism and can be switched between a transmission state in which the driving force is transmitted to the developing roller and a disconnected state in which the driving force is not transmitted to the developing roller, and one of the planetary gear mechanisms. The lever is equipped with a lever that can swing between a position where it engages one element to put the clutch in a transmission state and a position where it disengages from one element and puts the clutch in a disengaged state. By swinging, it switches between transmitting and disconnecting the driving force to the developing roller.

Japanese Patent Application Publication No. 2021-015149

Incidentally, as image forming apparatuses become smaller, it is desired to make the mechanism for controlling the contact and separation of the developing roller and the driving and stopping of the developing roller more compact.

Therefore, it is an object of the present invention to provide an image forming apparatus in which a mechanism for controlling the contact and separation of the developing roller and the driving and stopping of the developing roller can be made compact.

An image forming apparatus comprising a first photosensitive drum, the first developing cartridge having a motor, a first developing roller, a contact position where the first developing roller contacts the first photosensitive drum, and a first developing roller. a first developer cartridge that is movable between a separated position where the first developer cartridge is separated from the first photosensitive drum; a pressing position that presses the first developer cartridge to position the first developer cartridge in the separated position; a first cam follower that is slidably movable in the direction of the rotational axis of the first developing roller between a non-pressing position where the contact position is located, and a transmission position where driving force from the motor can be transmitted to the first developing roller. and a cutting position in which the driving force from the motor is not transmitted to the first developing roller; and a first switching lever that is perpendicular to the rotational axis direction between the first position and the second position. A linear motion plate capable of direct movement in the direction, which moves the first cam follower between a pressing position and a non-pressing position and moves the first switching lever between a transmission position and a cutting position. A linear motion plate is provided.
When the translation plate is in the first position, the first cam follower is in the pressing position and the first switching lever is in the cutting position, and when the translation plate is in the second position, the first cam follower is in the non-pressing position. The first switching lever is located at the pressing position, and the first switching lever is located at the transmission position.

According to such a configuration, the mechanism for controlling contact and separation of the developing roller and driving and stopping of the developing roller can be made compact.

The image forming apparatus also includes a rotating cam that rotates in conjunction with the linear motion of the linear plate, and the rotating cam is capable of contacting the first cam follower and is inclined with respect to the moving direction of the first cam follower. The first cam surface may be configured to have a first cam surface that slides the first cam follower between a pressed position and a non-pressed position by rotation of the rotary cam.

The linear motion plate is a second cam surface that can contact the first cam follower and is inclined with respect to the moving direction of the linear motion plate, and the linear motion of the translation plate moves the first cam follower away from the pressing position. The configuration may include a second cam surface that slides between the pressing position and the pressing position.

Further, the image forming apparatus may include a first spring that urges the first cam follower toward a non-pressed position.

According to this, when the linear motion plate is located at the second position, the first cam follower can be reliably located at the non-pressing position.

Further, the linear motion plate moves the first switching lever to the transmission position at a timing before the first cam follower moves to the non-pressing position, and moves the first switching lever at a timing after the first cam follower moves to the pressing position. It may be provided so as to be moved to the cutting position.

According to this, the first developing roller can be rotated before contacting the first photosensitive drum, and can be stopped after being separated from the first photosensitive drum.

Further, the image forming apparatus has a planetary gear mechanism including a sun gear, a ring gear, a carrier, and a planetary gear, and has a transmission state in which the driving force from the motor can be transmitted to the first developing roller, and a transmission state in which the driving force from the motor can be transmitted to the first developing roller. The first switching lever is provided with a clutch that can be switched between a disconnected state and a disconnected state in which no transmission occurs to the first developing roller, and the first switching lever engages one element having one of the sun gear, ring gear, and carrier of the planetary gear mechanism when located in the transmission position. The configuration may also be such that the clutch is placed in the transmitting state when the two elements are in the disengaged position, and the clutch is disengaged from one element when the clutch is in the disengaged position.

Further, the first switching lever is capable of swinging between the transmission position and the cutting position around the swing shaft, and is a first lever that is swingable around the swing shaft, and is a first lever that is swingable around the swing shaft. A first lever that swings in conjunction with linear motion, and a second lever that swings around a swing axis, which can be engaged with one element when the first switching lever is located at the transmission position. a second lever having a tip that separates from one element when the first switching lever is located in the cutting position; and a first protrusion provided on the first lever, the tip of the second lever having a tip that separates from one element. a first protrusion that restricts the swinging of the second lever in a direction toward the two elements; and a second spring that biases the second lever against the first lever in a direction that brings the second lever into contact with the first protrusion. The second lever may be configured to be able to swing relative to the first lever against the biasing force of the second spring.

According to this, even if the tip of the second lever is flipped when engaging with one element of the planetary gear mechanism, it is possible to prevent excessive force from being applied to the first switching lever.

Further, when the second lever swings a predetermined amount with respect to the first lever against the biasing force of the second spring, the second lever comes into contact with the first lever, thereby preventing the second lever from swinging. A second restricting protrusion may be provided.

According to this, the swing range of the second lever can be defined by the first protrusion and the second protrusion.

Further, the image forming apparatus may include a third spring that biases the first switching lever toward the transmission position.

According to this, when the linear motion plate is located at the second position, the first switching lever can be reliably located at the transmission position.

The image forming apparatus also includes a second developing cartridge having a second photosensitive drum and a second developing roller, and a contact position where the second developing roller contacts the second photosensitive drum, and a contact position where the second developing roller contacts the second developing roller. a second developer cartridge that is movable between a separation position where the second developer cartridge is separated from the photosensitive drum; a pressing position that presses the second developer cartridge to position the second developer cartridge in the separation position; and a pressing position that moves the second developer cartridge to a contact position. A second cam follower is slidably movable in the rotational axis direction between a non-pressing position and a transmission position where the driving force from the motor can be transmitted to the second developing roller. a second switching lever that is movable between a cutting position and a state in which no information is transmitted to the second developing roller; Direct movement is possible via the third position, which is a position between the second position, and the second cam follower is moved between the pressed position and the non-pressed position, and the second switching lever is transmitted. When the linear motion plate is located at the first position, the second cam follower is located at the pressing position, the second switching lever is located at the cutting position, and the linear motion plate is located at the first position. When the plate is in the second position, the second cam follower is in the non-pressing position, the second switching lever is in the transmission position, and when the linear plate is in the third position, the first cam follower is in the non-pressing position. The first switching lever may be located at the transmission position, the second cam follower may be located at the pressing position, and the second switching lever may be located at the cutting position.

According to this, when the linear motion plate is located at the first position, all the developing rollers are separated from the corresponding photosensitive drums, and when the linear motion plate is at the third position, only the first developing roller is moved away from the corresponding photosensitive drum. When the linear motion plate contacts the drum and is in the second position, all the developing rollers can be brought into contact with the corresponding photosensitive drum.

Further, the linear motion plate moves the second switching lever to the transmission position at a timing before the second cam follower moves to the non-pressing position, and moves the second switching lever at a timing after the second cam follower moves to the pressing position. It may be provided so as to be moved to the cutting position.

According to this, the second developing roller can be rotated before contacting the second photosensitive drum, and can be stopped after being separated from the second photosensitive drum.

Further, the first cam follower may be configured to include a pin extending in the direction of the rotation axis and pressing the first developer cartridge.

According to the above-described image forming apparatus, the mechanism for controlling the contact and separation of the developing roller and the driving and stopping of the developing roller can be made compact.

1 is a diagram showing a schematic configuration of an image forming apparatus. FIG. 3 is a side view showing the cam follower, rotary cam, development drive gear train, switching lever, linear plate, and frame of the first embodiment. FIG. 3 is a perspective view showing a cam follower, a rotating cam, a compression coil spring, a first shaft, and a frame. FIG. 2 is a diagram illustrating a configuration for moving the developer cartridge, and FIG. 11A shows the developer cartridge in the separated position, and FIG. 1B shows the developer cartridge in the contact position. They are a perspective view (a) of a cam follower, a rotary cam, and a first shaft as seen from the first shaft side, and a perspective view (b) as seen from the cam follower side. FIG. 2 is a cross-sectional view of a cam follower and a frame near the cam follower; FIG. FIG. 3 is a perspective view showing a switching lever, an input gear, an output gear, and a clutch in an disassembled state; FIG. They are side views of a switching lever, an input gear, a clutch, and an output gear, with (a) showing the switching lever in the disconnection position, and (b) showing the switching lever in the transmission position. An exploded perspective view (a) of the switching lever, a diagram (b) showing a state in which the swinging of the second lever is regulated by the first protrusion, and a state in which the swinging of the second lever is regulated by the second protrusion. This is diagram (c). FIG. 3 is a side view showing a cam follower, a rotating cam, a switching lever, a linear plate, and a frame. It is a figure (a), (b) explaining the position of a cam follower and a switching lever when a direct-acting plate is located in a 1st position. It is a figure (a), (b) explaining the position of a cam follower and a switching lever when a direct-acting plate is located between a 1st position and a 3rd position. It is a figure (a), (b) explaining the position of a cam follower and a switching lever when a linear motion plate is located in a 3rd position. It is a figure (a), (b) explaining the position of a cam follower and a switching lever when a direct-acting plate is located between a 3rd position and a 2nd position. It is a figure (a), (b) explaining the position of a cam follower and a switching lever when a linear motion plate is located in a 2nd position. FIG. 7 is a perspective view showing a cam follower, a compression coil spring, a first shaft, a linear plate, and a frame according to a second embodiment. It is a perspective view of a cam follower, a compression coil spring, a 1st shaft, and a linear plate seen from the frame side. FIG. 2 is a cross-sectional view of a cam follower, a linear motion plate, and a frame near the cam follower; FIG. It is a figure (a), (b) explaining the position of a cam follower and a switching lever when a direct-acting plate is located in a 1st position. It is a figure (a), (b) explaining the position of a cam follower and a switching lever when a linear motion plate is located in a 3rd position. It is a figure (a), (b) explaining the position of a cam follower and a switching lever when a linear motion plate is located in a 2nd position.

Next, a first embodiment will be described.
As shown in FIG. 1, the image forming apparatus 1 is a color printer and includes a housing 10, a sheet supply section 20, an image forming section 30, and a control section 2. In the embodiment, the right side of FIG. 1 is the front, the left side is the rear, the top and bottom are the top and bottom, and the front side of the paper in FIG. 1 is the left, and the back side of the paper is the right.

The sheet supply unit 20 includes a sheet tray 21 on which the sheets S are set, and a supply mechanism 22. The supply mechanism 22 includes a pickup roller 23 , a separation roller 24 , a separation pad 25 , a conveyance roller 26 , and a registration roller 27 . After the sheets S in the sheet tray 21 are sent out by a pickup roller 23, they are separated one by one between a separation roller 24 and a separation pad 25, and then sent to an image forming section 30 by a conveyance roller 26 and a registration roller 27. Supplied.

The image forming section 30 includes an exposure unit 40, a plurality of photosensitive drums 50, a plurality of developer cartridges 60, a transfer unit 70, and a fixing unit 80.
The exposure unit 40 includes a light source, a deflector, a lens, a mirror, etc. (not shown). The exposure unit 40 emits a light beam (see the one-dot chain line) to expose the surface of the photosensitive drum 50.

The photosensitive drum 50 includes a first photosensitive drum 50K corresponding to black, a second photosensitive drum 50Y corresponding to yellow, a third photosensitive drum 50M corresponding to magenta, and a fourth photosensitive drum 50C corresponding to cyan. . The third photosensitive drum 50M is disposed downstream of the second photosensitive drum 50Y in the conveyance direction of the sheet S (hereinafter simply referred to as the "conveyance direction"). The fourth photosensitive drum 50C is arranged downstream of the third photosensitive drum 50M in the transport direction. The first photosensitive drum 50K is arranged downstream of the fourth photosensitive drum 50C in the transport direction. That is, the second photosensitive drum 50Y, the third photosensitive drum 50M, the fourth photosensitive drum 50C, and the first photosensitive drum 50K are arranged in this order from the upstream side to the downstream side in the transport direction.

In this specification and drawings, when members provided corresponding to each color are explained by distinguishing the colors, Y, M, C, and K are added to the reference numerals, and when the members are explained without distinguishing the colors, , do not include Y, M, C, or K in the code.

A developer cartridge 60 is provided corresponding to each photosensitive drum 50. Specifically, the developer cartridge 60 includes a first developer cartridge 60K having a first developer roller 61K that supplies toner to the first photosensitive drum 50K, and a second developer roller 61Y that supplies toner to the second photosensitive drum 50Y. A fourth developer includes a second developer cartridge 60Y, a third developer roller 61M that supplies toner to the third photosensitive drum 50M, and a fourth developer roller 61C that supplies toner to the fourth photosensitive drum 50C. cartridge 60C.

The developing cartridge 60 is located between a contact position where the developing roller 61 contacts the corresponding photosensitive drum 50, indicated by a solid line, and a separation position, where the developing roller 61 is separated from the corresponding photosensitive drum 50, indicated by a phantom line. It is movable.

Specifically, the first developing cartridge 60K is movable between a contact position where the first developing roller 61K contacts the first photosensitive drum 50K and a separated position where the first developing roller 61K is separated from the first photosensitive drum 50K. It is. The second developing cartridge 60Y is movable between a contact position where the second developing roller 61Y contacts the second photosensitive drum 50Y and a separation position where the second developing roller 61Y is separated from the second photosensitive drum 50Y.

The third developing cartridge 60M is movable between a contact position where the third developing roller 61M contacts the third photosensitive drum 50M and a separation position where the third developing roller 61M is separated from the third photosensitive drum 50M. The fourth developing cartridge 60C is movable between a contact position where the fourth developing roller 61C contacts the fourth photosensitive drum 50C and a separation position where the fourth developing roller 61C is separated from the fourth photosensitive drum 50C.

The photosensitive drum 50 is rotatably supported by a drawer 55. A charger 52 for charging the photosensitive drums 50 is provided in the drawer 55 so as to correspond to each photosensitive drum 50 . The drawer 55 removably supports a plurality of developer cartridges 60. The drawer 55 can be attached to and removed from the housing 10 through the opening 10A of the housing 10 exposed by opening the front cover 11.

The transfer unit 70 includes a drive roller 71, a driven roller 72, an endless conveyor belt 73, and four transfer rollers 74. The conveyor belt 73 is stretched between the drive roller 71 and the driven roller 72, and its outer surface is in contact with each photosensitive drum 50. The transfer roller 74 is arranged inside the conveyor belt 73 and sandwiches the conveyor belt 73 with the corresponding photosensitive drum 50 .

The fixing unit 80 includes a heating roller 81 and a pressure roller 82 disposed opposite to the heating roller 81. A conveyance roller 15 and a discharge roller 16 are provided downstream of the fixing unit 80 in the conveyance direction.

In the image forming section 30 , the surface of the photosensitive drum 50 is uniformly charged by the charger 52 and then exposed to a light beam irradiated from the exposure unit 40 . As a result, an electrostatic latent image is formed on the photosensitive drum 50 based on the image data. Further, the toner contained in the developing cartridge 60 is carried on the surface of the developing roller 61, and is supplied from the developing roller 61 located at the contact position to the electrostatic latent image formed on the photosensitive drum 50. As a result, a toner image is formed on the photosensitive drum 50.

The toner image formed on the photosensitive drum 50 is transferred onto the sheet S by conveying the sheet S supplied onto the conveying belt 73 and passing between the photosensitive drum 50 and the transfer roller 74. be done. Then, the toner image is fixed on the sheet S by passing between the heating roller 81 and the pressure roller 82. Thereafter, the sheet S is discharged onto the paper discharge tray 13 by the conveyance roller 15 and the discharge roller 16.

As shown in FIG. 2, the image forming apparatus 1 includes a first motor M1, a second motor M2, a cam follower 110, a rotating cam 120, a developing drive gear train 130, a switching lever 140, and a linear plate. 200. Furthermore, the housing 10 has a frame 300.
The first motor M1 is a drive source that drives the developing roller 61, and the second motor M2 is a drive source that drives the linear motion plate 200. The first motor M1 corresponds to a "motor".

As shown in FIG. 3, the cam follower 110 is slidable in the direction of the rotation axis of the first developing roller 61K (corresponding to the direction in which the dashed line shown in FIG. 3 extends; hereinafter simply referred to as the "rotation axis direction"). . Specifically, the cam follower 110 has two positions: a pressing position in which the developer cartridge 60 is pressed to move the developer cartridge 60 to a separated position as shown in FIG. 4(a), and a contact position as shown in FIG. 4(b). It slides in the direction of the rotation axis between the pressed position and the non-pressed position.

As shown in FIGS. 4A and 4B, the developer cartridge 60 is supported by the drawer 55 so as to be movable back and forth. The drawer 55 has a contact portion 55A and a pressing member 55B. The abutted portion 55A is a portion abutted by a slide member 66, which will be described later, and is composed of a roller rotatable around an axis extending vertically. The pressing member 55B is urged backward by a spring 55C, and when the developer cartridge 60 is installed in the drawer 55, it presses the developer cartridge 60 and brings the developer roller 61 into contact with the photosensitive drum 50. move it.

The developer cartridge 60 includes a case 65 that accommodates toner and a slide member 66. The slide member 66 can slide in the direction of the rotation axis with respect to the case 65, and is moved in the direction of the rotation axis when pressed by the cam follower 110. The slide member 66 includes a shaft 66A that is slidably supported by the case 65, a first contact member 66B provided at one end of the shaft 66A, and a second contact member 66C provided at the other end of the shaft 66A. It has

The first contact member 66B has a pressing surface 66D and a slope 66E inclined with respect to the axial direction, and the second contact member 66C has a slope 66F inclined similarly to the slope 66E. The pressing surface 66D is pressed by the cam follower 110. When the slide member 66 is pressed by the cam follower 110, the slopes 66E and 66F come into contact with the abutted portion 55A and urge the developer cartridge 60 in a direction perpendicular to the rotational axis direction, so that the developer roller 61 is pressed against the photosensitive drum. 50 to a separate position. A spring 67 is arranged between the first contact member 66B and the case 65 to bias the slide member 66 toward the left.

Returning to FIG. 3, the cam follower 110 includes a first cam follower 110K, a second cam follower 110Y, a third cam follower 110M, and a fourth cam follower 110C.

The first cam follower 110K has a rotation axis line between a pressing position in which the first developing cartridge 60K is pressed to position the first developing cartridge 60K in a separated position and a non-pressing position in which the first developing cartridge 60K is located in a contact position. Slide in the direction. The second cam follower 110Y has a rotation axis line between a pressing position in which the second developing cartridge 60Y is pressed to position the second developing cartridge 60Y in a separated position and a non-pressing position in which the second developing cartridge 60Y is located in a contact position. Slide in the direction.

The third cam follower 110M has an axis of rotation between a pressing position in which the third developing cartridge 60M is pressed to position the third developing cartridge 60M in a separated position and a non-pressing position in which the third developing cartridge 60M is located in a contact position. Slide in the direction. The fourth cam follower 110C has a rotation axis between a pressing position in which the fourth developer cartridge 60C is pressed to position the fourth developer cartridge 60C in a separated position and a non-pressing position in which the fourth developer cartridge 60C is located in a contact position. Slide in the direction.

As shown in FIGS. 5A and 5B, the cam followers 110 (first cam follower 110K, second cam follower 110Y, third cam follower 110M, and fourth cam follower 110C) include a pin 111, a first flange portion 112, It has a connection wall portion 113, a second flange portion 114, a cam contact portion 115, and a rotation restriction portion 116.

The pin 111 presses the corresponding developer cartridge 60 when the cam follower 110 moves from the non-pressed position to the pressed position. For example, the pin 111 of the first cam follower 110K presses the first developer cartridge 60K. The pin 111 extends in the direction of the rotation axis. The pin 111 has a cylindrical shape with a bottom closed on one side in the direction of the rotation axis.

The image forming apparatus 1 includes a first shaft 119 extending in the direction of the rotation axis. The first shaft 119 is provided in the housing 10. Four first shafts 119 are provided corresponding to each cam follower 110 (see FIG. 3). By engaging with the first shaft 119, the pin 111 is supported so as to be slidable in the rotational axis direction with respect to the housing 10. Thereby, the cam follower 110 can slide in the direction of the rotational axis between the pressed position and the non-pressed position.

The first flange portion 112 extends from the outer peripheral surface of the pin 111 toward the outside in the radial direction of the pin 111 .
The connecting wall portion 113 connects the first flange portion 112 and the second flange portion 114. The connecting wall portion 113 has a cylindrical shape and extends from the radially outer end of the first flange portion 112 toward one side in the rotation axis direction.
The second flange portion 114 extends from one end of the connection wall portion 113 in the rotational axis direction toward the outside in the radial direction of the connection wall portion 113 .

The cam contact portion 115 contacts a first cam surface 126 of the rotary cam 120, which will be described later. The cam contact portion 115 extends from a portion of the radially outer end of the second flange portion 114 toward the other side in the rotational axis direction. The cam contact portion 115 has an arcuate wall shape centered on the central axis of the pin 111 . Two cam contact portions 115 are provided. The two cam contact portions 115 have a point-symmetrical shape with respect to the central axis of the pin 111 . The surface of the cam contact portion 115 that faces the first cam surface 126 in the rotating direction of the rotating cam 120 is an inclined surface 115A that is substantially parallel to the first cam surface 126.

The rotation regulating portion 116 has a rib shape that protrudes outward in the radial direction of the pin 111 from the outer circumferential surface of the cam contact portion 115 and extends in the rotation axis direction. Two rotation regulating parts 116 are provided corresponding to each cam contact part 115. The rotation regulating portion 116 is provided so as to protrude from an end of the cam contact portion 115 opposite to the inclined surface 115A in the circumferential direction of the arcuate cam contact portion 115.

The rotary cam 120 rotates in conjunction with the linear movement of the linear motion plate 200, thereby sliding the cam follower 110 between a pressed position and a non-pressed position. As shown in FIG. 3, the rotating cam 120 includes a first rotating cam 120K that slides the first cam follower 110K between a pressed position and a non-pressed position, and a second cam follower 110Y that slides between a pressed position and a non-pressed position. A second rotating cam 120Y that slides the third cam follower 110M between the pressed position and the non-pressed position, a third rotating cam 120M that slides the third cam follower 110M between the pressed position and the non-pressed position, and a fourth cam follower 110C that slides the third cam follower 110M between the pressed position and the non-pressed position. It includes a fourth rotating cam 120C that slides between the pressing position and the pressing position.

Returning to FIG. 5, the rotating cams 120 (first rotating cam 120K, second rotating cam 120Y, third rotating cam 120M, and fourth rotating cam 120C) include a ring-shaped disk portion 121 and a third rotating cam 120. 1 cam portion 122, a cam arm 123, and a cam boss 124.

The first cam portion 122 has an arcuate wall shape centered on the rotation center of the rotary cam 120, and protrudes from the disk portion 121 toward one side in the rotation axis direction. Two first cam portions 122 are provided. The two first cam parts 122 have a point-symmetrical shape with respect to the rotation center of the rotation cam 120.

Rotating cam 120 further includes a first holding surface 125, a first cam surface 126, and a second holding surface 127.
The first holding surface 125 is an end surface on one side in the rotational axis direction of the first cam portion 122, and holds the corresponding cam follower 110 in the pressing position. The first holding surface 125 is substantially orthogonal to the direction of the rotation axis.

The second holding surface 127 is a part of the end surface of the disk portion 121 on one side in the rotational axis direction, and holds the corresponding cam follower 110 in a non-pressing position. The second holding surface 127 is substantially orthogonal to the direction of the rotation axis. The second holding surface 127 is located at the same position as the first holding surface 125 in the radial direction of a circle centered on the rotation center of the rotating cam 120.

The first cam surface 126 is a surface connecting the first holding surface 125 and the second holding surface 127, and when the rotating cam 120 rotates, the corresponding cam follower 110 is slid between the pressed position and the non-pressed position. . For example, the first cam surface 126 of the first rotating cam 120K slides the first cam follower 110K between a pressed position and a non-pressed position by rotation of the first rotating cam 120K.

The first cam surface 126 is capable of contacting the cam contact portion 115 of the corresponding cam follower 110 and is inclined with respect to the direction of movement of the corresponding cam follower 110 . For example, the first cam surface 126 of the first rotating cam 120K can contact the cam contact portion 115 of the first cam follower 110K, and is inclined with respect to the moving direction of the first cam follower 110K. The first cam surface 126 is provided on the first cam portion 122. The first cam surface 126 is inclined so that as it goes from the second holding surface 127 toward the first holding surface 125, it approaches the corresponding developer cartridge 60 (the near side in FIG. 5(b)).

The cam arm 123 extends from the end opposite to the first cam surface 126 of one of the first cam parts 122 and from the disc part 121 in the radial direction of a circle centered on the rotation center of the rotary cam 120. It extends.
The cam boss 124 is provided so as to extend from the tip of the cam arm 123 toward one side in the rotational axis direction. Cam boss 124 has a cylindrical shape.

As shown in FIGS. 6A and 6B, the frame 300 includes a plate-shaped main body portion 310, a through hole 320, and a cam support portion 330.
The through hole 320 is a hole through which the pin 111 of the cam follower 110 passes. As shown in FIG. 6(a), the pin 111 protrudes from the frame 300 and presses the developer cartridge 60 when the cam follower 110 is located at the pressing position, and as shown in FIG. 6(b), the pin 111 When located at the pressing position, it is retracted and no longer presses the developer cartridge 60. Four through holes 320 are provided corresponding to each cam follower 110.

The cam support portion 330 is a portion that rotatably supports the rotary cam 120. As shown in FIG. 3, the cam support portions 330 have a substantially cylindrical shape, and four cam support portions 330 are provided corresponding to each rotary cam 120. The cam support portion 330 is provided so as to protrude from a portion of the main body portion 310 around the through hole 320 (see FIG. 6) in the rotation axis direction. The rotating cam 120 is rotatable with respect to the frame 300 while the first cam portion 122 is engaged with the cam support portion 330.

The cam support portion 330 has a pair of rotation restriction grooves 331 extending in the direction of the rotation axis. The rotation of the cam follower 110 around the first shaft 119 is restricted by the rotation restriction portion 116 engaging with the rotation restriction groove 331 of the corresponding cam support portion 330 .

The image forming apparatus 1 includes a compression coil spring 150 as an example of a first spring. Four compression coil springs 150 are provided corresponding to each cam follower 110. The compression coil spring 150 biases the corresponding cam follower 110 toward the unpressed position. For example, the compression coil spring 150 provided corresponding to the first cam follower 110K biases the first cam follower 110K toward the non-pressed position.

As shown in FIG. 6(b), the compression coil spring 150 is disposed between the portion around the through hole 320 of the main body portion 310 of the frame 300 and the first flange portion 112 of the cam follower 110. The compression coil spring 150 is compressed when the cam follower 110 slides from the non-pressed position shown in FIG. 6(b) to the pressed position shown in FIG. 6(a), and the restoring force generated at this time causes the first flange portion 112 is urged in a direction away from the main body portion 310. Thereby, the compression coil spring 150 urges the cam follower 110 from the pressed position toward the non-pressed position.

As shown in FIG. 2, the developer drive gear train 130 is capable of transmitting the driving force of the first motor M1 to the developer cartridge 60. The developer drive gear train 130 includes four input gears 131 (131K, 131Y, 131M, 131C) and four clutches 160 (160K, 160Y, 160M, 160C) provided corresponding to each developer cartridge 60. It includes four output gears 133 (133K, 133Y, 133M, 133C).

The input gear 131 is a gear into which the driving force from the first motor M1 is input.
The output gear 133 is a gear that outputs the driving force from the first motor M1 to the corresponding developer cartridge 60 (developing roller 61).

The clutch 160 can be switched between a transmission state in which the driving force from the first motor M1 can be transmitted to the corresponding developing roller 61 and a disconnected state in which the driving force from the first motor M1 is not transmitted to the corresponding developing roller 61. It is. For example, the clutch 160K has a transmission state in which the driving force from the first motor M1 can be transmitted to the first developing roller 61K, and a disconnected state in which the driving force from the first motor M1 is not transmitted to the first developing roller 61K. Switchable.

As shown in FIGS. 7(a) and 7(b), the clutch 160 (160K, 160Y, 160M, 160C) has a planetary gear mechanism including a sun gear 161, a ring gear 162, a carrier 163, and two planetary gears 164. . Clutch 160 has an input element 160A, an output element 160B, and a transmission element 160D. Input element 160A, output element 160B, and transmission element 160D are coaxially rotatable.

In the clutch 160, among the input element 160A, the output element 160B, and the transmission element 160D, one has a sun gear 161, one of the elements other than the sun gear 161 has a ring gear 162, and the remaining one has a carrier 163. In the embodiment, the transmission element 160D has a sun gear 161, the input element 160A has a ring gear 162, and the output element 160B has a carrier 163.

The input element 160A is an element into which driving force is input, and includes a ring gear 162 and a first outer gear 165 formed on the outer periphery of the ring gear 162. The first outer gear 165 meshes with the input gear 131.
The output element 160B is an element that outputs driving force, and includes a carrier 163 and a second outer peripheral gear 166 formed on the outer periphery of the carrier 163. The second outer gear 166 meshes with the output gear 133. Further, the carrier 163 has two shaft portions 163A that rotatably support the planetary gear 164.

The transmission element 160D is configured to be able to transmit driving force from the input element 160A to the output element 160B when the rotation is regulated, and not to transmit the driving force from the input element 160A to the output element 160B when the rotation is not regulated. This is an important element. The transmission element 160D includes a sun gear 161, a rotating plate 167 that rotates together with the sun gear 161, and a plurality of claws 168 provided on the outer periphery of the rotating plate 167.
The planetary gear 164 is rotatably supported by the shaft portion 163A of the carrier 163. Planetary gear 164 meshes with sun gear 161 and ring gear 162.

When the rotation of the transmission element 160D is stopped, the clutch 160 is in a transmission state in which the driving force input to the first outer gear 165 can be transmitted to the second outer gear 166. On the other hand, when the transmission element 160D is in a rotatable state, it is in a disconnected state in which the driving force input to the first outer gear 165 cannot be transmitted to the second outer gear 166. In the clutch 160, when driving force is input to the first outer gear 165 in a disengaged state and a load is applied to the second outer gear 166, the output element 160B does not rotate and the transmission element 160D idles.

The switching lever 140 has a transmission position where the driving force from the first motor M1 can be transmitted to the developing roller 61 as shown in FIG. 8(b), and a transmission position where the driving force from the first motor M1 can be transmitted to the developing roller 61 as shown in FIG. It is movable between a cutting position and a state in which the driving force is not transmitted to the developing roller 61. As shown in FIG. 2, the switching lever 140 includes a first switching lever 140K, a second switching lever 140Y, a third switching lever 140M, and a fourth switching lever 140C.

The first switching lever 140K is movable between a transmission position where the driving force can be transmitted to the first developing roller 61K and a disconnection position where the driving force is not transmitted to the first developing roller 61K. . The second switching lever 140Y is movable between a transmission position where the driving force can be transmitted to the second developing roller 61Y and a cutting position where the driving force is not transmitted to the second developing roller 61Y. .

The third switching lever 140M is movable between a transmission position where the driving force can be transmitted to the third developing roller 61M and a cutting position where the driving force is not transmitted to the third developing roller 61M. . The fourth switching lever 140C is movable between a transmission position where the driving force can be transmitted to the fourth developing roller 61C and a cutting position where the driving force is not transmitted to the fourth developing roller 61C. .

As shown in FIG. 8(b), when the switching lever 140 is located at the transmission position, it engages with the claw portion 168 of the transmission element 160D to put the clutch 160 in the transmission state. In embodiments, the transmission element is an example of "one element having any of the sun gear, ring gear, and carrier of a planetary gear mechanism." Further, as shown in FIG. 8(a), when the switching lever 140 is located at the disconnection position, the switching lever 140 separates from the pawl portion 168 of the transmission element 160D to place the clutch 160 in the disconnected state. The switching lever 140 can swing between a transmission position and a cutting position around a swing shaft 140A that is the central axis of the second shaft 340.

The second shaft 340 is a shaft that swingably supports the switching lever 140, and is provided in the frame 300, as shown in FIG. The second shaft 340 extends in the direction of the rotation axis. Four second shafts 340 are provided corresponding to each switching lever 140.

As shown in FIG. 9(a), the switching lever 140 (first switching lever 140K, second switching lever 140Y, third switching lever 140M, and fourth switching lever 140C) includes a first lever 141 and a second lever 142. and a torsion spring 143 as an example of a second spring.

The first lever 141 is swingable around the swing shaft 140A, and swings in conjunction with the translation of the translation plate 200. The first lever 141 includes a first support portion 141A, a first arm 141B, a lever boss 141C, a first protrusion 141E, a second protrusion 141F, a first spring contact portion 141G, and a spring hook portion 141H. .

The first support portion 141A has a cylindrical shape, and is supported so as to be swingable around the swing shaft 140A by engaging with the second shaft 340.
The first arm 141B extends from the outer peripheral surface of the first support portion 141A toward the outside in the radial direction of the first support portion 141A.
The lever boss 141C protrudes from the tip of the first arm 141B toward one side in the rotation axis direction. The lever boss 141C has a cylindrical shape.

The first protrusion 141E and the second protrusion 141F protrude from the outer peripheral surface of the first support part 141A toward the outside in the radial direction of the first support part 141A. The first protrusion 141E and the second protrusion 141F protrude in a different direction from the first arm 141B. The first protrusion 141E and the second protrusion 141F are provided so as to be spaced apart from each other in the circumferential direction of the first support portion 141A.
The first spring contact portion 141G and the spring hook portion 141H protrude from the first arm 141B toward the other side in the rotation axis direction.

The second lever 142 is swingable around the swing shaft 140A and can be engaged with the transmission element 160D of the clutch 160. The second lever 142 has a second support portion 142A, a second arm 142B, a tip 142C, a lever protrusion 142D, and a second spring contact portion 142G.

The second support portion 142A has a cylindrical shape, and is supported so as to be swingable around the swing shaft 140A by engaging with the first support portion 141A of the first lever 141. The second lever 142 is also swingable relative to the first lever 141 around the swing shaft 140A.
The second arm 142B extends from the outer peripheral surface of the second support portion 142A toward the outside in the radial direction of the second support portion 142A.

The tip 142C protrudes from the tip of the second arm 142B toward the transmission element 160D (see FIG. 9(b)). The tip 142C can engage with the claw portion 168 of the transmission element 160D when the switching lever 140 is located in the transmission position, and separates from the claw portion 168 of the transmission element 160D when the switching lever 140 is located in the cutting position. . For example, the tip 142C of the first switching lever 140K can be engaged with the claw portion 168 of the transmission element 160D when the first switching lever 140K is located at the transmission position, and when the first switching lever 140K is located at the cutting position. In this case, the transmission element 160D is detached from the claw portion 168.

The lever protrusion 142D protrudes from the second support portion 142A toward the other side in the rotation axis direction. As shown in FIG. 9(b), the lever protrusion 142D is arranged between the first protrusion 141E and the second protrusion 141F of the first lever 141 when the second lever 142 is assembled to the first lever 141. .
The second spring contact portion 142G protrudes from the second arm 142B toward the other side in the rotation axis direction.

The torsion spring 143 biases the second lever 142 against the first lever 141 in a direction that brings the lever protrusion 142D of the second lever 142 into contact with the first protrusion 141E provided on the first lever 141. The torsion spring 143 includes a coil 143A, a first spring arm 143B extending radially outward from one end of the coil 143A, and a second spring arm 143C extending radially outward from the other end of the coil 143A. and has.

The torsion spring 143 is arranged such that the coil 143A is engaged with the second shaft 340, the first spring arm 143B is in contact with the first spring contact part 141G, and the second spring arm 143C is in contact with the second spring contact part 142G. ing. The torsion spring 143 biases the second lever 142 clockwise in FIG. 9(b), bringing the lever protrusion 142D into contact with the first protrusion 141E. The first protrusion 141E restricts the swinging of the second lever 142 in the direction in which the tip 142C of the second lever 142 approaches the transmission element 160D.

As shown in FIG. 9(c), the second lever 142 can swing counterclockwise in the figure relative to the first lever 141 against the biasing force of the torsion spring 143. The first lever 141 is provided with a second protrusion 141F. The second protrusion 141F causes the lever protrusion 142D of the second lever 142 to swing when the second lever 142 swings a predetermined amount counterclockwise in the figure with respect to the first lever 141 against the biasing force of the torsion spring 143. The contact restricts further swinging of the second lever 142.

Returning to FIG. 9B, the image forming apparatus 1 includes a tension coil spring 144 as an example of a third spring. Four tension coil springs 144 are provided corresponding to each switching lever 140 (see FIG. 2). The tension coil spring 144 biases the corresponding switching lever 140 toward the transmission position. For example, a tension coil spring 144 provided corresponding to the first switching lever 140K biases the first switching lever 140K toward the transmission position.

Specifically, one end of the tension coil spring 144 is hooked on a spring hook 141H provided on the first lever 141, and the other end is placed in a position in front of the spring hook 141H of the housing 10 in a slightly stretched state. It is hooked onto a provided spring hook (not shown). As a result, the tension coil spring 144 biases the switching lever 140 clockwise in the drawing, which is the direction in which the tip 142C approaches the transmission element 160D. Thereby, the tension coil spring 144 urges the switching lever 140 from the cutting position to the transmission position.

As shown in FIG. 10, the linear motion plate 200 is supported by the frame 300 (casing 10) so as to be linearly movable. Specifically, the translation plate 200 is capable of translation in a direction perpendicular to the rotational axis direction between a first position shown in FIG. 11 and a second position shown in FIG. 15. Specifically, the translation plate 200 is capable of translation in the front-rear direction, which is the direction in which the photosensitive drums 50 are lined up, between the first position and the second position. The second position is a position before the first position.

Further, the translation plate 200 is capable of translation between the first position and the second position via the third position shown in FIG. 13 . The third position is a position between the first position and the second position. In the embodiment, the translation plate 200 is movable in translation forward from the first position to the third position, further from the third position to the second position, and from the second position to the third position. Furthermore, it is capable of direct movement rearward from the third position to the first position.

Returning to FIG. 10, frame 300 has a plurality of guides 351-359. Each of the guides 351 to 359 is provided to protrude from the main body 310 in the direction of the rotation axis and extend back and forth. Guides 351 to 355 are provided above linear motion plate 200, and guides 356 to 359 are provided below linear motion plate 200. The guides 351 to 355 and the guides 356 to 359 hold the linear motion plate 200 between them from above and below, and support the linear motion plate 200 so as to be linearly movable back and forth.

The linear motion plate 200 moves the first cam follower 110K between a pressing position and a non-pressing position and moves the first switching lever 140K between a cutting position and a transmission position by linear movement back and forth. It is set in. Further, the linear motion plate 200 moves the second cam follower 110Y, the third cam follower 110M, and the fourth cam follower 110C between the pressed position and the non-pressed position by direct movement back and forth, and also moves the second switching lever 140Y, The third switching lever 140M and the fourth switching lever 140C are provided to be moved between the cutting position and the transmission position.

As shown in FIG. 11, when the linear motion plate 200 is located at the first position, the first cam follower 110K is located at the pressing position, and the first switching lever 140K is located at the cutting position. Further, the second cam follower 110Y, the third cam follower 110M, and the fourth cam follower 110C are located at the pressing position, and the second switching lever 140Y, the third switching lever 140M, and the fourth switching lever 140C are located at the cutting position. At this time, the image forming apparatus 1 is in a state in which all of the developer cartridges 60 are located at separate positions, and the driving force from the first motor M1 is not transmitted to any of the developer rollers 61.

As shown in FIG. 13, when the linear motion plate 200 is located at the third position, the first cam follower 110K is located at the non-pressing position, and the first switching lever 140K is located at the transmission position. Further, the second cam follower 110Y, the third cam follower 110M, and the fourth cam follower 110C are located at the pressing position, and the second switching lever 140Y, the third switching lever 140M, and the fourth switching lever 140C are located at the cutting position. At this time, in the image forming apparatus 1, the first black developing cartridge 60K is located at the contact position, and the driving force from the first motor M1 can be transmitted to the first developing roller 61K, and yellow, magenta, and cyan are developed. The cartridges 60Y, 60M, and 60C are located at separate positions, and are in a state in which the driving force from the first motor M1 is not transmitted to the developing rollers 61Y, 61M, and 61C.

As shown in FIG. 15, when the linear motion plate 200 is located at the second position, the first cam follower 110K is located at the non-pressing position, and the first switching lever 140K is located at the transmission position. Further, the second cam follower 110Y, the third cam follower 110M, and the fourth cam follower 110C are located at the non-pressing position, and the second switching lever 140Y, the third switching lever 140M, and the fourth switching lever 140C are located at the transmission position. At this time, the image forming apparatus 1 is in a state where all the developing cartridges 60 are located at the contact position and the driving force from the first motor M1 can be transmitted to all the developing rollers 61.

The rotating cam 120 is arranged between a first cam position shown in FIG. 11 in which the corresponding cam follower 110 is located in the pressed position and a second cam position shown in FIG. 15 in which the corresponding cam follower 110 is located in the non-pressed position. It can be rotated. When the rotating cam 120 is located at the second cam position, the cam contact portion 115 of the cam follower 110 contacts the second holding surface 127 of the rotating cam 120 and is supported by the second holding surface 127. Further, as shown in FIG. 11, when the rotating cam 120 is located at the first cam position, the cam contact portion 115 of the cam follower 110 contacts the first holding surface 125 of the rotating cam 120, and the first holding surface 125.

As shown in FIG. 10, the linear motion plate 200 has a first cam groove 210, a first lever groove 220, a second cam groove 230, a second lever groove 240, and a rack gear 250. Further, the image forming apparatus 1 includes a drive gear 260 rotatably supported by the housing 10 .

The first cam groove 210 moves the first cam follower 110K between the pressed position and the non-pressed position by the linear motion of the linear motion plate 200. The cam boss 124 of the first rotating cam 120K engages with the first cam groove 210. The first cam groove 210 has a vertical groove 211 that extends vertically, and a lateral groove 212 that extends rearward from the upper end of the vertical groove 211. The vertical groove 211 acts on the cam boss 124 of the first rotating cam 120K as the linear motion plate 200 moves linearly, and rotates the first rotating cam 120K between the first cam position and the second cam position. let The lateral groove 212 maintains the first rotating cam 120K in the second cam position.

The first lever groove 220 moves the first switching lever 140K between the cutting position and the transmission position by the translation of the translation plate 200. The lever boss 141C of the first switching lever 140K engages with the first lever groove 220. The first lever groove 220 has a vertical groove 222 that extends vertically, a lateral groove 221 that extends forward from the lower end of the vertical groove 222, and a lateral groove 223 that extends rearward from the upper end of the vertical groove 222. The lateral groove 221 maintains the first switching lever 140K in the cutting position. The vertical groove 222 acts on the lever boss 141C of the first switching lever 140K as the linear motion plate 200 moves linearly, and rotates the first switching lever 140K between the cutting position and the transmission position. The lateral groove 223 maintains the first switching lever 140K in the transmission position.

The linear motion plate 200 moves the first switching lever 140K to the transmission position at a timing before the first cam follower 110K moves to the non-pressing position, and moves the first switching lever 140K to the transmission position at a timing after the first cam follower 110K moves to the pressing position. It is provided to move the lever 140K to the cutting position. Specifically, the vertical groove 222 of the first lever groove 220 is arranged downstream of the vertical groove 211 of the first cam groove 210 in the direction in which the linear motion plate 200 moves from the first position to the second position. . More specifically, the vertical groove 222 of the first lever groove 220 is arranged in front of the vertical groove 211 of the first cam groove 210.

The second cam groove 230 moves the cam followers 110Y, 110M, and 110C between the pressed position and the non-pressed position by the linear motion of the linear motion plate 200. Three second cam grooves 230 are provided corresponding to the cam followers 110Y, 110M, and 110C. The cam bosses 124 of the corresponding rotary cams 120Y, 120M, and 120C engage with the second cam grooves 230.

The second cam groove 230 has a vertical groove 232 that extends vertically, and a lateral groove 231 that extends forward from the lower end of the vertical groove 232. The lateral grooves 231 maintain the corresponding rotating cams 120Y, 120M, 120C in the first cam position. The vertical grooves 232 act on the cam bosses 124 of the corresponding rotary cams 120Y, 120M, and 120C as the linear motion plate 200 moves, and move the rotary cams 120Y, 120M, and 120C to the first cam position and the second cam position. rotate between.

The second lever groove 240 moves the switching levers 140Y, 140M, and 140C between the cutting position and the transmission position by the linear motion of the linear motion plate 200. Three second lever grooves 240 are provided corresponding to the switching levers 140Y, 140M, and 140C. The lever bosses 141C of the corresponding switching levers 140Y, 140M, and 140C engage with the second lever groove 240.

The second lever groove 240 has a vertical groove 242 that extends vertically, a lateral groove 241 that extends forward from the lower end of the vertical groove 242, and a lateral groove 243 that extends rearward from the upper end of the vertical groove 242. The lateral grooves 241 maintain the corresponding switching levers 140Y, 140M, and 140C in the cutting position. The vertical groove 242 acts on the lever boss 141C of the corresponding switching lever 140Y, 140M, 140C as the linear motion plate 200 moves linearly, and rotates the switching lever 140Y, 140M, 140C between the cutting position and the transmission position. let The lateral grooves 243 maintain the corresponding switching levers 140Y, 140M, 140C in the transmission position.

The linear motion plate 200 transmits the second switching lever 140Y, the third switching lever 140M, and the fourth switching lever 140C at a timing before the second cam follower 110Y, third cam follower 110M, and fourth cam follower 110C move to the non-pressing position. position, and at the timing after the second cam follower 110Y, third cam follower 110M, and fourth cam follower 110C have moved to the pressing position, the second switching lever 140Y, third switching lever 140M, and fourth switching lever 140C are set to the cutting position. It is designed to be moved.

Specifically, the vertical groove 242 of the second lever groove 240 is arranged downstream of the vertical groove 232 of the second cam groove 230 in the direction in which the linear motion plate 200 moves from the first position to the second position. . More specifically, the vertical groove 242 of the second lever groove 240 is arranged in front of the vertical groove 232 of the second cam groove 230.

The rack gear 250 is formed on the lower surface of the rear end of the linear motion plate 200. Rack gear 250 meshes with drive gear 260. The drive gear 260 rotates when the driving force from the second motor M2 is input. The second motor M2 is capable of forward and reverse rotation. For example, the linear motion plate 200 is linearly moved from the rear to the front when the second motor M2 rotates forward and the drive gear 260 rotates clockwise in FIG. 10, and when the second motor M2 rotates reversely. When the drive gear 260 rotates counterclockwise in FIG. 10, it moves linearly from front to rear.

The control unit 2 includes a CPU, a ROM, a RAM, an input/output unit, and the like, and performs control by executing a program stored in advance. The control unit 2 controls driving and stopping of the motors M1 and M2. Further, the control unit 2 causes the linear motion plate 200 to move linearly back and forth by controlling the rotation direction of the second motor M2, thereby causing the developing roller 61 to come into contact with and separate from the corresponding photosensitive drum 50, and Controls driving and stopping of the developing roller 61.

Next, the operation of the image forming apparatus 1 of the first embodiment will be explained.
As shown in FIG. 11, when the linear motion plate 200 is located at the first position, all the cam followers 110 are located at the pressing position, and all the switching levers 140 are located at the cutting position. At this time, the cam boss 124 of the first cam follower 110K is located at the lower end of the vertical groove 211 of the first cam groove 210, and the lever boss 141C of the first switching lever 140K is located at the lateral groove 221 of the first lever groove 220. Further, the cam bosses 124 of the cam followers 110Y, 110M, and 110C are located in the horizontal grooves 231 of the corresponding second cam grooves 230, and the lever bosses 141C of the switching levers 140Y, 140M, and 140C are located in the horizontal grooves 241 of the corresponding second lever grooves 240. To position.

When the drive gear 260 rotates clockwise in FIG. 11, the translation plate 200 translates forward from the first position to the second position. Then, the cam boss 124 of the first rotating cam 120K is pushed forward by the wall of the vertical groove 211, and the first rotating cam 120K rotates counterclockwise in FIG. 11 from the first cam position. start.

While the first switching lever 140K is maintained at the cutting position, the lever boss 141C moves relative to the lower end of the vertical groove 222 of the first lever groove 220. Then, as the lever boss 141C is pushed forward by the wall of the vertical groove 222, the first switching lever 140K swings from the cutting position to the transmission position as shown in FIG. 12. At this time, since the biasing force of the tension coil spring 144 also acts, the first switching lever 140K reliably swings from the cutting position to the transmission position. As a result, the tip 142C engages with the claw portion 168 of the transmission element 160D of the clutch 160K, the driving force from the first motor M1 is transmitted to the first developer cartridge 60K, and the first developer roller 61K Start driving.

When the first rotating cam 120K rotates, the surface that contacts the cam contact portion 115 of the first cam follower 110K switches from the first holding surface 125 to the first cam surface 126, and the first cam surface 126 causes the first cam follower 110K to rotate. 110K is slid from the pressed position to the non-pressed position.

As shown in FIG. 13, when the linear motion plate 200 is located at the third position, the first rotating cam 120K rotates to the second cam position, and the surface of the first cam follower 110K that contacts the cam contact portion 115 is The first cam surface 126 is switched to the second holding surface 127, and the first cam follower 110K is located at the non-pressing position. As a result, the first developing cartridge 60K is located at the contact position, and the first developing roller 61K comes into contact with the first photosensitive drum 50K.

While the linear motion plate 200 moves from the first position to the third position, the rotary cams 120Y, 120M, and 120C do not rotate because the cam boss 124 relatively moves in the lateral groove 231 of the second cam groove 230, and 1 cam position. Further, the switching levers 140Y, 140M, and 140C do not swing due to the lever boss 141C relatively moving in the lateral groove 241 of the second lever groove 240, and are maintained at the cutting position.

When the linear motion plate 200 stops at the third position, printing can be performed using only the black first developing roller 61K.

When the linear motion plate 200 further moves forward from the third position to the second position, the cam bosses 124 of the rotating cams 120Y, 120M, and 120C move relative to the lower end of the vertical groove 232 of the second cam groove 230. . Then, as the cam boss 124 is pushed forward by the wall of the vertical groove 232, the rotating cams 120Y, 120M, and 120C begin to rotate counterclockwise in FIG. 13 from the first cam position.

Furthermore, the lever boss 141C of the switching levers 140Y, 140M, and 140C moves relative to the lower end of the vertical groove 242 of the second lever groove 240. Then, when the lever boss 141C is pushed forward by the wall of the vertical groove 242, the switching levers 140Y, 140M, and 140C swing from the cutting position to the transmission position as shown in FIG. 14. At this time, since the biasing force of the tension coil spring 144 also acts, the switching levers 140Y, 140M, and 140C reliably swing from the cutting position to the transmission position. As a result, the tip 142C engages with the claw portion 168 of the transmission element 160D of the corresponding clutch 160Y, 160M, 160C, and the driving force from the first motor M1 is transmitted to the developer cartridge 60Y, 60M, 60C. Then, the developing rollers 61Y, 61M, and 61C start to be driven.

When the rotating cams 120Y, 120M, 120C rotate, the surface that contacts the cam contact portion 115 of the corresponding cam follower 110Y, 110M, 110C switches from the first holding surface 125 to the first cam surface 126, and the first cam The surfaces 126 cause the corresponding cam followers 110Y, 110M, and 110C to slide from the pressed position to the non-pressed position.

As shown in FIG. 15, when the linear plate 200 is located at the second position, the rotary cams 120Y, 120M, and 120C rotate to the second cam position, and the cam contact portions 115 of the corresponding cam followers 110Y, 110M, and 110C The surface that contacts the first cam surface 126 switches to the second holding surface 127, and the cam followers 110Y, 110M, and 110C are located at non-pressing positions. As a result, the developing cartridges 60Y, 60M, and 60C are located at the contact position, and the developing rollers 61Y, 61M, and 61C come into contact with the corresponding photosensitive drums 50Y, 50M, and 50C.

When the linear motion plate 200 is located at the second position, printing can be performed using all the developing rollers 61.

When the drive gear 260 rotates counterclockwise in FIG. 15, the linear motion plate 200 moves linearly backward from the second position toward the first position. Then, the cam bosses 124 of the rotary cams 120Y, 120M, 120C are pushed backward by the wall of the vertical groove 232 of the second cam groove 230, so that the rotary cams 120Y, 120M, 120C are moved from the second cam position to the rear view. 15 starts rotating clockwise. The switching levers 140Y, 140M, and 140C do not swing because the lever boss 141C relatively moves in the lateral groove 243 of the second lever groove 240, and are maintained at the transmission position.

The cam followers 110Y, 110M, 110C slide from the non-pressed position toward the pressed position by the rotation of the corresponding rotating cams 120Y, 120M, 120C, and press the corresponding developer cartridges 60Y, 60M, 60C. As a result, the developing rollers 61Y, 61M, and 61C are separated from the corresponding photosensitive drums 50Y, 50M, and 50C.

When the developing rollers 61Y, 61M, 61C are separated from the corresponding photosensitive drums 50Y, 50M, 50C, the lever bosses 141C of the switching levers 140Y, 140M, 140C move to the upper end of the vertical groove 242 of the second lever groove 240, as shown in FIG. Move relative to the part. Then, as the lever boss 141C is pushed backward by the wall of the vertical groove 242, the switching levers 140Y, 140M, and 140C swing from the transmission position to the cutting position against the biasing force of the tension coil spring 144. As a result, the tip end 142C is disengaged from the transmission element 160D of the corresponding clutch 160Y, 160M, 160C, and the driving force from the first motor M1 is no longer transmitted to the developing cartridge 60Y, 60M, 60C, and the developing roller 61Y, 61M, 61C stops.

As shown in FIG. 13, when the linear motion plate 200 is located at the third position, the cam followers 110Y, 110M, 110C have their cam contact portions 115 contact the first holding surfaces 125 of the corresponding rotary cams 120Y, 120M, 120C. do.
While the linear motion plate 200 moves from the second position to the third position, the first rotating cam 120K does not rotate because the cam boss 124 relatively moves in the lateral groove 212 of the first cam groove 210, and the second cam 120K does not rotate. maintained in position. Further, the first switching lever 140K does not swing due to the relative movement of the lever boss 141C in the lateral groove 223 of the first lever groove 220, and is maintained at the cutting position.

When the linear motion plate 200 moves further backward from the third position toward the first position, the cam boss 124 of the first rotating cam 120K moves relative to the upper end of the vertical groove 211 of the first cam groove 210. Then, as the cam boss 124 is pushed backward by the wall of the vertical groove 211, the first rotating cam 120K starts to rotate clockwise in FIG. 13 from the first cam position. The first switching lever 140K does not swing due to the relative movement of the lever boss 141C in the lateral groove 223 of the first lever groove 220, and is maintained at the transmission position.

The first cam follower 110K slides from the non-pressed position toward the pressed position by rotation of the first rotating cam 120K, and presses the first developer cartridge 60K. As a result, the first developing roller 61K is separated from the first photosensitive drum 50K.

When the first developing roller 61K separates from the first photosensitive drum 50K, the lever boss 141C of the first switching lever 140K moves relative to the upper end of the vertical groove 222 of the first lever groove 220, as shown in FIG. Then, as the lever boss 141C is pushed rearward by the wall of the vertical groove 222, the first switching lever 140K swings from the transmission position to the cutting position against the biasing force of the tension coil spring 144. As a result, the leading end 142C disengages from the transmission element 160D of the clutch 160K, the driving force from the first motor M1 is no longer transmitted to the first developer cartridge 60K, and the first developer roller 61K stops. Then, as shown in FIG. 11, when the linear motion plate 200 is located at the first position, the cam contact portion 115 of the first cam follower 110K contacts the first holding surface 125 of the first rotating cam 120K.

According to the first embodiment described above, the mechanism for controlling the contact and separation of the developing roller 61 and the driving and stopping of the developing roller 61 can be made compact. For example, if a rotating cam is provided with a cam surface that slides a cam follower, the diameter of the cam will become larger, or a gear train or electromagnetic clutch will be required to transmit the driving force from the motor to the cam, making it more compact. There are limits to what you can do. In the configuration using the linear motion plate 200 as in the first embodiment, for example, the rotary cam 120 does not need to rotate once, so the configuration can save space, and the driving force from the motor can be rotated. There is no need to provide a gear train or an electromagnetic clutch for transmitting data to the moving cam 120. Therefore, the mechanism for controlling the contact and separation of the developing roller 61 and the driving and stopping of the developing roller 61 can be made compact.

Furthermore, since the compression coil spring 150 is provided that urges the cam follower 110 toward the non-pressing position, the cam follower 110 can be reliably positioned at the non-pressing position when the linear motion plate 200 is located at the second position.

Further, since the corresponding switching lever 140 is moved to the transmission position at a timing before the cam follower 110 moves to the non-pressing position, the developing roller 61 can be rotated before it comes into contact with the corresponding photosensitive drum 50. Further, since the corresponding switching lever 140 is moved to the cutting position at the timing after the cam follower 110 moves to the pressing position, the developing roller 61 can be stopped after being separated from the corresponding photosensitive drum 50.

Furthermore, since the second lever 142 of the switching lever 140 can swing relative to the first lever 141 against the biasing force of the torsion spring 143, the distal end 142C of the second lever 142 rotates the transmission element 160D. Even if it is flipped when engaging the claw portion 168, it is possible to prevent excessive force from being applied to the switching lever 140.

Further, since the first lever 141 is provided with the first protrusion 141E and the second protrusion 141F, the swing range of the second lever 142 can be defined by the first protrusion 141E and the second protrusion 141F.

Further, since the tension coil spring 144 is provided to urge the switching lever 140 toward the transmission position, the switching lever 140 can be reliably positioned at the transmission position when the linear motion plate 200 is located at the second position.

Further, when the linear motion plate 200 is located at the first position, all the developing rollers 61 are separated from the corresponding photosensitive drums 50, and when the linear motion plate 200 is at the third position, only the first developing roller 61K is moved away from the corresponding photosensitive drum 50. When the linear motion plate 200 is in the second position, all the developing rollers 61 can be brought into contact with the corresponding photosensitive drums 50. As a result, for example, there is a mode in which all developing rollers 61 are separated from the corresponding photosensitive drums 50, a mode in which printing is executed using only the first developing roller 61K, and a mode in which printing is executed using all developing rollers 61. You can switch between modes.

Next, a second embodiment will be described. In addition, below, the points different from the first embodiment will be explained, and the explanation of the same points will be omitted as appropriate, for example, by assigning the same reference numerals to the same elements.
As shown in FIG. 16, the image forming apparatus 1 includes a cam follower 110, a compression coil spring 150, a linear motion plate 200, and a frame 300. The image forming apparatus 1 of the second embodiment does not include a rotating cam.

The cam followers 110 (first cam follower 110K, second cam follower 110Y, third cam follower 110M, and fourth cam follower 110C) include a pin 111 and a first flange portion 112 extending from the outer peripheral surface of the pin 111 toward the outside in the radial direction of the pin 111. and has.

The linear motion plate 200 has a first plate part 201 , a second plate part 202 , a third plate part 203 , and a fourth plate part 204 . The first plate portion 201 extends from the upper end of the second plate portion 202 toward one side in the rotation axis direction. The second plate portion 202 has elongated holes 205 that are long in the front and back for passing the four first shafts 119 therethrough. The third plate portion 203 extends from the lower end of the second plate portion 202 toward one side in the rotation axis direction and is connected to the upper end of the fourth plate portion 204 . The fourth plate portion 204 is located at a different position from the second plate portion 202 in the direction of the rotation axis. Specifically, the fourth plate portion 204 is located closer to the frame 300 than the second plate portion 202 in the rotation axis direction. The fourth plate portion 204 has a first lever groove 220, three second lever grooves 240, and a rack gear 250.

As shown in FIG. 17, the linear motion plate 200 further includes a second cam portion 270 and a third cam portion 280.
The second cam part 270 is provided corresponding to the first cam follower 110K, and has a rib shape that projects from the upper and lower parts of the long hole 205 of the second plate part 202 to one side in the rotation axis direction. There is. The second cam portion 270 has a second cam surface 271 and a holding surface 272.

The holding surface 272 is an end surface of the second cam portion 270 on one side in the rotational axis direction, and holds the first cam follower 110K at the pressing position. The holding surface 272 is substantially orthogonal to the direction of the rotation axis.
The second cam surface 271 slides the first cam follower 110K between the pressed position and the non-pressed position by the linear motion of the linear motion plate 200. The second cam surface 271 is capable of contacting the first cam follower 110K and is inclined with respect to the moving direction of the linear motion plate 200. Specifically, the second cam surface 271 is inclined so as to approach the first developer cartridge 60K (the near side in FIG. 17) from the rear toward the front.

Three third cam portions 280 are provided corresponding to the second cam follower 110Y, the third cam follower 110M, and the fourth cam follower 110C. It has a rib shape that protrudes on one side. The length of the third cam portion 280 is longer than the length of the second cam portion 270 in the direction of movement of the linear motion plate 200 (front-back direction). The third cam portion 280 has a third cam surface 281 and a holding surface 282.

The holding surface 282 is an end surface on one side in the rotational axis direction of the third cam portion 280, and holds the corresponding cam followers 110Y, 110M, and 110C at the pressing position. The holding surface 282 is substantially perpendicular to the direction of the rotation axis. In the moving direction (back and forth direction) of the linear motion plate 200, the length of the holding surface 282 is longer than the length of the holding surface 272.

The third cam surface 281 slides the corresponding cam followers 110Y, 110M, and 110C between the pressed position and the non-pressed position by the linear movement of the linear motion plate 200. The third cam surface 281 can contact the corresponding cam followers 110Y, 110M, and 110C, and is inclined with respect to the moving direction of the linear motion plate 200. Specifically, the third cam surface 281 is inclined so as to approach the corresponding developer cartridges 60Y, 60M, and 60C (on the near side in FIG. 17) from the rear toward the front.

As shown in FIG. 18(a), when the cam follower 110 is located at the pressing position, the first flange portion 112 contacts the holding surfaces 272, 282 of the corresponding cam portions 270, 280. Further, as shown in FIG. 18(b), when the cam follower 110 is located at the non-pressing position, the first flange portion 112 does not come into contact with the corresponding cam portions 270, 280. When the cam follower 110 is located at the non-pressing position, the first flange portion 112 contacts the end surface of the second plate portion 202 on one side in the rotational axis direction. The cam follower 110 is biased toward the non-pressed position by a compression coil spring 150.

Next, the operation of the image forming apparatus 1 according to the second embodiment will be explained. Note that in FIGS. 19(a), 20(a), and 21(a), the holding surfaces 272, 282 of the cam portions 270, 280 are hatched with dots.
As shown in FIG. 19, when the linear motion plate 200 is located at the first position, all the cam followers 110 are located at the pressing position, and all the switching levers 140 are located at the cutting position.

When the linear motion plate 200 moves linearly forward from the first position shown in FIG. 19 to the third position shown in FIG. 20, the first switching lever 140K swings from the cutting position to the transmission position by the first lever groove 220. , the tip 142C engages with the claw portion 168 (transmission element 160D) of the clutch 160K. As a result, the driving force from the first motor M1 is transmitted to the first developing cartridge 60K, and the first developing roller 61K starts to be driven.

In the first cam follower 110K, the surface that the first flange portion 112 contacts switches from the holding surface 272 of the second cam portion 270 to the second cam surface 271, and the second cam surface 271 moves the surface from the pressed position to the non-pressed position. Slide to move. Then, when the first flange portion 112 of the first cam follower 110K no longer contacts the second cam surface 271 (second cam portion 270) and contacts the second plate portion 202, the first cam follower 110K is located at the non-pressed position. As a result, the first developing cartridge 60K is located at the contact position, and the first developing roller 61K comes into contact with the first photosensitive drum 50K.

While the linear motion plate 200 moves from the first position to the third position, the switching levers 140Y, 140M, and 140C are maintained at the cutting position. Further, the cam followers 110Y, 110M, and 110C do not slide because the first flange portion 112 continues to be in contact with the holding surface 282 of the third cam portion 280, and are maintained at the pressed position.

When the linear motion plate 200 further moves forward from the third position shown in FIG. 20 to the second position shown in FIG. It swings, and the tip 142C engages with the claw portion 168 (transmission element 160D) of the corresponding clutch 160Y, 160M, 160C. As a result, the driving force from the first motor M1 is transmitted to the developing cartridges 60Y, 60M, and 60C, and the developing rollers 61Y, 61M, and 61C begin to be driven.

In the cam followers 110Y, 110M, and 110C, the surface in contact with the first flange portion 112 is switched from the holding surface 282 of the corresponding third cam portion 280 to the third cam surface 281, and the third cam surface 281 moves the surface from the pressed position to the non-pressed position. Slide towards the position. Then, in the cam followers 110Y, 110M, and 110C, when the first flange portion 112 no longer contacts the third cam surface 281 (third cam portion 280) and contacts the second plate portion 202, the cam followers 110Y, 110M, and 110C are located at the non-pressing position. As a result, the developing cartridges 60Y, 60M, and 60C are located at the contact position, and the developing rollers 61Y, 61M, and 61C come into contact with the corresponding photosensitive drums 50Y, 50M, and 50C.

As shown in FIG. 21, when the linear motion plate 200 is located at the second position, all the cam followers 110 are located at the non-pressing position, and all the switching levers 140 are located at the transmission position.

When the linear motion plate 200 moves linearly from the second position shown in FIG. 21 to the third position shown in FIG. Then, the tip 142C separates from the transmission element 160D of the corresponding clutch 160Y, 160M, 160C. As a result, the driving force from the first motor M1 is no longer transmitted to the developing cartridges 60Y, 60M, and 60C, and the developing rollers 61Y, 61M, and 61C are stopped.

In the cam followers 110Y, 110M, and 110C, the first flange portion 112 contacts the third cam surface 281 of the corresponding third cam portion 280, and the third cam surface 281 slides from the non-pressed position toward the pressed position. Then, the cam followers 110Y, 110M, and 110C are located at the pressing position when the surface that the first flange portion 112 contacts switches from the third cam surface 281 to the holding surface 282. As a result, the developing cartridges 60Y, 60M, and 60C are located at the separated positions, and the developing rollers 61Y, 61M, and 61C are separated from the corresponding photosensitive drums 50Y, 50M, and 50C.

While the linear motion plate 200 moves from the second position to the third position, the first switching lever 140K is maintained at the transmission position. Further, the first cam follower 110K does not slide because the first flange portion 112 does not contact the second cam portion 270 and continues to contact the second plate portion 202, and is maintained at the non-pressing position.

When the linear motion plate 200 further moves linearly from the third position shown in FIG. 20 to the first position shown in FIG. , the tip 142C separates from the transmission element 160D of the clutch 160K. As a result, the driving force from the first motor M1 is no longer transmitted to the first developing cartridge 60K, and the first developing roller 61K stops.

The first cam follower 110K has the first flange portion 112 in contact with the second cam surface 271 of the second cam portion 270, and is slid by the second cam surface 271 from the non-pressed position to the pressed position. The first cam follower 110K is located at the pressing position when the surface that the first flange portion 112 contacts switches from the second cam surface 271 to the holding surface 272. As a result, the first developing cartridge 60K is located at the separated position, and the first developing roller 61K is separated from the first photosensitive drum 50K.

According to the second embodiment described above, as in the first embodiment, the mechanism for controlling contact and separation of the developing roller 61 and driving and stopping of the developing roller 61 can be made compact. In particular, in the second embodiment, since the cam follower 110 is directly slid by the linear plate 200 without a rotary cam, the contact and separation of the developing roller 61 and the driving and stopping of the developing roller 61 are controlled. The mechanism can be made more compact.

Although the embodiments have been described above, the image forming apparatus can be implemented with appropriate modifications as illustrated below.

In the embodiment described above, the compression coil spring 150 was used as an example of the first spring that urges the cam follower toward the non-pressed position, but the first spring may be a spring other than the compression coil spring as long as it has the same function. It's okay. The same applies to the second spring and the third spring. Furthermore, the image forming apparatus may have a configuration that does not include the third spring, for example.

In the embodiment described above, the first lever 141 of the switching lever 140 was provided with the second protrusion 141F for defining the swinging range of the second lever 142, but for example, the second protrusion may be provided on the first lever. It is also possible to have a configuration that is not specified. Further, in the embodiment, the switching lever 140 has the first lever 141 and the second lever 142, and the second lever 142 is swingable with respect to the first lever 141. , the first lever 141 and the second lever 142 of the embodiment described above may be integrally molded.

In the embodiment described above, the linear motion plate 200 was configured to be able to move linearly between the first position and the second position via the third position. It may be configured such that it can be moved in a direct manner only between two positions. In this case, for example, when the linear motion plate is located at the first position, all cam followers are located at the pressing position, all switching levers are located at the cutting position, and when the linear motion plate is located at the second position, A configuration may also be adopted in which all cam followers are located at the non-pressing position and all switching levers are located at the transmission position.

Further, the linear motion plate is configured to be linearly movable between the first position and the second position via a third position and a fourth position that is a position between the third position and the second position. It may be. Furthermore, the linear motion plate moves between the first position and the second position via a third position, a fourth position, and a fifth position that is a position between the fourth position and the second position. It may also be configured to be capable of direct movement. In this case, for example, when the translation plate is located at the first position, the four cam followers are located at the pressing position, the four switching levers are located at the cutting position, and when the translation plate is located at the third position, When one cam follower is located at the non-pressing position, one corresponding switching lever is located at the transmission position, and the linear motion plate is located at the fourth position, two cam followers are located at the non-pressing position, and the corresponding two switching levers are located at the fourth position. When the two switching levers are in the transmission position and the linear plate is in the fifth position, the three cam followers are in the non-pressing position, the corresponding three switching levers are in the transmission position, and the linear plate is in the fifth position. When located at the second position, the four cam followers may be located at the non-pressing position and the four switching levers may be located at the transmission position.

In the embodiment described above, the image forming apparatus 1 is a color printer that includes a plurality of photosensitive drums 50 and, correspondingly, a plurality of developer cartridges 60, a cam follower 110, and a switching lever 140. The printer may be a monochrome printer that includes only one photosensitive drum, one developer cartridge, one cam follower, and one switching lever. Further, for example, the image forming apparatus may be a copying machine, a multifunction device, or the like.

The elements described in the embodiments and modifications described above may be implemented in any combination.

1 Image forming device 50K First photosensitive drum 60K First developing cartridge 61K First developing roller 110K First cam follower 140K First switching lever 200 Direct-acting plate M1 First motor

Claims (12)

An image forming apparatus including a first photosensitive drum,
motor and
A first developing cartridge having a first developing roller, the contact position where the first developing roller contacts the first photosensitive drum, and the separation position where the first developing roller separates from the first photosensitive drum. a first developer cartridge movable between;
the first developing roller between a pressing position in which the first developing cartridge is pressed to position the first developing cartridge in the separated position and a non-pressing position in which the first developing cartridge is positioned in the contact position; a first cam follower that is slidable in the direction of the rotational axis;
It is movable between a transmission position where the driving force from the motor can be transmitted to the first developing roller and a cutting position where the driving force from the motor is not transmitted to the first developing roller. a first switching lever;
A linear motion plate capable of linear movement in a direction perpendicular to the rotational axis direction between a first position and a second position, the linear motion moving the first cam follower between the pressed position and the non-pressed position. a linear motion plate that moves the first switching lever between the transmission position and the cutting position;
When the linear motion plate is located at the first position, the first cam follower is located at the pressing position, and the first switching lever is located at the cutting position,
The image forming apparatus is characterized in that when the linear motion plate is located at the second position, the first cam follower is located at the non-pressing position, and the first switching lever is located at the transmission position. A rotary cam that rotates in conjunction with the linear motion of the linear motion plate,
The rotating cam is a first cam surface that can contact the first cam follower and is inclined with respect to the moving direction of the first cam follower, and the rotating cam moves the first cam follower to the first cam follower. The image forming apparatus according to claim 1, further comprising a first cam surface that slides between a pressed position and the non-pressed position. The linear motion plate is a second cam surface that is capable of contacting the first cam follower and is inclined with respect to the moving direction of the linear motion plate, and the linear motion plate moves the first cam follower. The image forming apparatus according to claim 1, further comprising a second cam surface that slides between a pressed position and the non-pressed position. The image forming apparatus according to claim 2 or 3, further comprising a first spring that urges the first cam follower toward the non-pressed position. The linear motion plate moves the first switching lever to the transmission position at a timing before the first cam follower moves to the non-pressing position, and at a timing after the first cam follower moves to the pressing position. The image forming apparatus according to any one of claims 1 to 4, wherein the first switching lever is provided to move the first switching lever to the cutting position. It has a planetary gear mechanism including a sun gear, a ring gear, a carrier, and a planetary gear, and has a transmission state in which the driving force from the motor can be transmitted to the first developing roller, and a transmission state in which the driving force from the motor can be transmitted to the first developing roller. Equipped with a clutch that can be switched between a disconnected state that does not transmit information to the roller,
When the first switching lever is located at the transmission position, the first switching lever engages one element having one of the sun gear, the ring gear, and the carrier of the planetary gear mechanism to bring the clutch into the transmission state, and The image forming apparatus according to any one of claims 1 to 5, wherein the image forming apparatus disengages from the one element and puts the clutch in the disengaged state when the image forming apparatus is located at the disengaged position. The first switching lever is swingable around a swing axis between the transmission position and the cutting position,
a first lever that is swingable around the swing axis and that swings in conjunction with the translation of the translation plate;
a second lever swingable around the swing axis, the second lever being engageable with the one element when the first switching lever is located at the transmission position; a second lever having a tip that disengages from said one element when in a cutting position;
a first protrusion provided on the first lever that restricts swinging of the second lever in a direction in which the tip of the second lever approaches the one element;
a second spring that biases the second lever against the first lever in a direction that brings the second lever into contact with the first protrusion;
has
7. The image forming apparatus according to claim 6, wherein the second lever is swingable relative to the first lever against the biasing force of the second spring. The second lever contacts the first lever when the second lever swings a predetermined amount with respect to the first lever against the biasing force of the second spring. 8. The image forming apparatus according to claim 7, further comprising a second protrusion that restricts the swinging of the image forming apparatus. The image forming apparatus according to any one of claims 1 to 8, further comprising a third spring that urges the first switching lever toward the transmission position. a second photosensitive drum;
A second developing cartridge having a second developing roller, the contact position where the second developing roller contacts the second photosensitive drum, and the separation position where the second developing roller separates from the second photosensitive drum. a second developer cartridge movable between;
in the rotational axis direction between a pressing position in which the second developer cartridge is pressed to position the second developer cartridge in the separated position and a non-pressing position in which the second developer cartridge is located in the contact position. a second cam follower that can slide;
It is movable between a transmission position where the driving force from the motor can be transmitted to the second developing roller and a cutting position where the driving force from the motor is not transmitted to the second developing roller. A second switching lever;
The linear motion plate is linearly movable between the first position and the second position via a third position that is between the first position and the second position. the second cam follower is moved between the pressed position and the non-pressed position, and the second switching lever is moved between the transmission position and the cutting position,
When the linear motion plate is located at the first position, the second cam follower is located at the pressing position, and the second switching lever is located at the cutting position,
When the linear motion plate is located at the second position, the second cam follower is located at the non-pressing position, and the second switching lever is located at the transmission position,
When the linear motion plate is located at the third position, the first cam follower is located at the non-pressing position, the first switching lever is located at the transmitting position, and the second cam follower is located at the pressing position. The image forming apparatus according to any one of claims 1 to 9, wherein the second switching lever is located at the cutting position. The linear motion plate moves the second switching lever to the transmission position at a timing before the second cam follower moves to the non-pressing position, and at a timing after the second cam follower moves to the pressing position. The image forming apparatus according to claim 10, wherein the image forming apparatus is provided to move the second switching lever to the cutting position. The image forming apparatus according to any one of claims 1 to 11, wherein the first cam follower has a pin extending in the direction of the rotation axis and pressing the first developer cartridge. Device.

Images