Developing contact separation apparatus, image forming apparatus

Abstract

The developing contact separation apparatus 40 includes: a monochrome operation member 41A and a color operation member 41B, which move the developers 23A and 23B between a contact position and a separation position relative to the photosensitive drums 21A and 21B; and a rotating member 51, which rotates between a first rotating position during non-printing, a second rotating position during color printing, and a third rotating position during monochrome printing. In the first rotating position, the rotating member 51 moves the developers 23A and 23B to the separation position via the respective operation members 41A and 41B. In the second rotating position, the rotating member 51 moves the developers 23A and 23B to the contact position via the respective operation members 41A and 41B. In the third rotating position, the rotating member 51 moves the monochrome developer 23A to the contact position via the monochrome operation member 41A and moves the color developer 23B to the separation position via the color operation member 41B. This achieves space-saving design of the developing contact separation apparatus 40.

Description

Technical Field

[0001] This invention relates to a developing contact separation apparatus and an image forming apparatus. Background Technology

[0002] In a tandem image forming apparatus, a photosensitive drum is prepared for each color of toner. During monochrome printing in such an apparatus, if all developing rollers rotate, the rotation of the color developing rollers can easily accelerate the deterioration of the color toner. Therefore, an image forming apparatus exists that includes a contact separation device that switches the contact separation state between the developing rollers and the photosensitive drum according to the printing status. This contact separation device ensures that only the monochrome developing roller contacts the photosensitive drum during monochrome printing, thus suppressing the rotation of the color developing rollers. Summary of the Invention

[0003] However, according to the image forming apparatus, it is impossible to ensure the installation space for the contact separation device when separating the drum contact.

[0004] Therefore, the object of the present invention is to save space in the installation space of the developing contact separation device and to suppress the deterioration of toner.

[0005] One aspect of the present invention relates to a developing contact separation apparatus comprising: a monochrome operating member that moves a monochrome developer between a contact position in contact with a monochrome photosensitive drum and a separation position separated from the monochrome photosensitive drum; a color operating member that moves a color developer between a contact position in contact with a color photosensitive drum and a separation position separated from the color photosensitive drum; and a rotating member that rotates between a first rotating position during non-printing, a second rotating position during color printing, and a third rotating position during monochrome printing. In the first rotating position, the rotating member moves the monochrome developer to the separation position via the monochrome operating member and moves the color developer to the separation position via the color operating member. In the second rotating position, the rotating member moves the monochrome developer to the contact position via the monochrome operating member and moves the color developer to the contact position via the color operating member. In the third rotating position, the rotating member moves the monochrome developer to the contact position via the monochrome operating member and moves the color developer to the separation position via the color operating member.

[0006] An image forming apparatus according to one aspect of the present invention includes: a developing contact separation device according to one aspect of the present invention; and an image forming unit for forming an image on a recording medium.

[0007] According to the present invention, during non-printing operations, each developer is separated from each photosensitive drum via its respective operating component. During color printing, each developer contacts each photosensitive drum via its respective operating component. During monochrome printing, the color developer is separated from the color photosensitive drum via the color operating component. In this way, developers not used during monochrome printing and non-printing operations are not rotated by the photosensitive drum, thus suppressing toner degradation in those developers. Furthermore, space-saving design of the developer contact separation device is achieved, preventing the image forming apparatus from becoming too large. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of the image forming apparatus of this embodiment.

[0009] Figure 2 This is a perspective view of the developing contact separation apparatus of this embodiment.

[0010] Figure 3 This is an exploded perspective view of the developing contact separation apparatus of this embodiment.

[0011] Figure 4 This diagram illustrates the contact separation operation of the developing contact separation device during non-printing operations in this embodiment.

[0012] Figure 5 This diagram illustrates the contact separation operation of the developing contact separation device during color printing in this embodiment.

[0013] Figure 6 This diagram illustrates the contact separation operation of the developing contact separation device during monochrome printing in this embodiment.

[0014] Figure 7 This diagram shows the contact state between the developer and the photosensitive drum in this embodiment.

[0015] Figure 8 This diagram shows the separation state of the developer and the photosensitive drum in this embodiment.

[0016] Figure 9 This diagram illustrates an example of the maintenance of the image forming apparatus according to this embodiment. Detailed Implementation

[0017] Hereinafter, an image forming apparatus according to an embodiment of one aspect of the present invention will be described with reference to the accompanying drawings. Figure 1This is a schematic diagram of the image forming apparatus according to this embodiment. Furthermore, in the following description, a printer will be used as an example of the image forming apparatus. Arrows FR and RE, appropriately marked in each figure, indicate the front and rear sides of the image forming apparatus. Additionally, monochrome components are labeled with reference numeral A, and color components with reference numeral B; however, reference numerals A and B may sometimes be omitted when monochrome and color applications are not specifically defined.

[0018] like Figure 1 As shown, the image forming apparatus 1 has a box-shaped housing 10. A paper feed cassette 11 for holding paper bundles is provided at the lower part of the housing 10, and a paper discharge tray 12 for stacking images of completed paper is provided at the upper part of the housing 10. An intermediate transfer belt 17 is provided above the paper feed cassette 11, mounted on rollers 14, 15, and 16 of the transfer apparatus 13. Multiple image forming units 18 are arranged above the intermediate transfer belt 17 along its transport direction. The multiple image forming units 18 are housed in a single unit housing (cassette) 19 (see reference). Figure 9 ).

[0019] In each image forming unit 18, a photosensitive drum 21 is rotatably disposed and rolls in contact with the intermediate transfer belt 17. Around each photosensitive drum 21, a belt conveyor 22, a developer 23, a primary transfer roller 24, and a cleaning roller 25 are arranged in the sequence of a single transfer process. In each developer 23, a developing housing 71 containing toner is provided according to the color of each toner. Above each image forming unit 18, an exposure device 26 is disposed to irradiate the photosensitive drum 21 with a laser. Behind each image forming unit 18, a cleaning device 27 is disposed to remove waste toner from the intermediate transfer belt 17.

[0020] Within the rear portion of the housing 10, a transport path L is formed for conveying paper from the paper feed cassette 11 to the paper discharge tray 12 via multiple rollers. A paper feed roller 31 is located upstream (downward) of the transport path L, and a positioning roller 32 is located downstream of the paper feed roller 31 within the transport path L. A secondary transfer roller 33 is located downstream of the positioning roller 32 within the transport path L, at the rear end of the intermediate transfer belt 17. A fixing roller 34 is located downstream of the secondary transfer roller 33 within the transport path L, and a paper discharge roller 35 is located at the downstream end (upper side) of the transport path L.

[0021] During image formation in the image forming apparatus 1, after the surface of the photosensitive drum 21 is charged by the charge carrier 22, an electrostatic latent image is formed on the surface of the photosensitive drum 21 by a laser from the exposure unit 26. Next, toner is attached to the electrostatic latent image on the surface of the photosensitive drum 21 from the developer 23 to form a toner image, and the toner image is transferred from the surface of the photosensitive drum 21 to the surface of the intermediate transfer belt 17 in one pass. In each image forming unit 18, toner images of each color are transferred to the intermediate transfer belt 17 in one pass, thereby forming a full-color toner image on the surface of the intermediate transfer belt 17. Waste toner remaining on the photosensitive drum 21 is removed by the cleaning roller 25.

[0022] On the other hand, paper is taken from the paper tray 11 by the paper feed roller 31 and fed out from the positioning roller 32 toward the secondary transfer roller 33. A full-color toner image is transferred a second time from the surface of the intermediate transfer belt 17 onto the surface of the paper via the secondary transfer roller 33, and the transferred paper is then conveyed toward the fixing roller 34 downstream of the secondary transfer roller 33. The toner image is fixed onto the paper at the fixing roller 34, and the fixed paper is discharged onto the paper tray 12 via the paper discharge roller 35. Thus, the toner image transferred onto the paper passes through the fixing roller 34, thereby forming an image on the surface of the paper.

[0023] However, the image forming apparatus 1 of this embodiment is designed for both color and monochrome printing. In color printing, all developing rollers 72 of the developing units 23 need to be in contact with the photosensitive drum 21, but in monochrome printing, it is not necessary for the developing rollers 72 of the developing units 23 other than those for monochrome printing to be in contact with the photosensitive drum 21. By stopping the unused developing rollers 72, toner degradation can be suppressed, thus extending the lifespan of the developing units 23. Furthermore, when printing stops, the intermediate transfer belt 17 is cleaned by the cleaning device 27, but this requires separating all developing rollers 72 from the photosensitive drum 21.

[0024] Therefore, it is preferable to separate each developer 23 from each photosensitive drum 21 according to the printing state of the image forming apparatus 1. If the contact separation structure between the developer 23 and the photosensitive drum 21 becomes complex, the cost increases and sufficient installation space is required, potentially leading to a larger image forming apparatus 1. Therefore, in the image forming apparatus 1 of this embodiment, a longitudinally elongated developer contact separation device 40 is provided along the side of the intermediate transfer belt 17 to save space. In addition, the developer contact separation device 40 is formed using a simple structure of a rotating cam and two operating levers, enabling each developer 23 to contact and separate from each photosensitive drum 21.

[0025] Reference Figure 2 as well as Figure 3 The developing contact separation device will be described. Figure 2 This is a perspective view of the developing contact separation apparatus of this embodiment. Figure 3This is an exploded perspective view of the developing contact separation apparatus of this embodiment. Furthermore, in Figure 2 as well as Figure 3 The image only shows the side wall of the transfer device that supports the intermediate transfer belt.

[0026] like Figure 2 as well as Figure 3 As shown, the developing contact separation device 40 is mounted on the side wall 57 of the transfer device 13. The developing contact separation device 40 includes a monochrome operating lever (monochrome operating component) 41A and a color operating lever (color operating component) 41B. The monochrome operating lever 41A extends from the front to the middle of the side wall 57, and the color operating lever 41B extends from the middle to the rear of the side wall 57. The inner surface of the rear half of the monochrome operating lever 41A and the outer surface of the front half of the color operating lever 41B are cut into a stepped shape, such that the rear half of the monochrome operating lever 41A and the front half of the color operating lever 41B overlap in the width direction.

[0027] The front and rear ends of the monochrome operating lever 41A are supported on the side wall 57 via a pair of connecting rods 42A and 43A. The monochrome operating lever 41A, side wall 57, and connecting rods 42A and 43A form a parallel linkage mechanism, allowing the monochrome operating lever 41A to swing vertically while maintaining a parallel state. A torsion spring 44A is installed at the base of the connecting rod 43A at the rear end of the monochrome operating lever 41A, pressing the monochrome operating lever 41A downwards by the elastic force of the torsion spring 44A. A mountain-shaped protrusion 49A protrudes upwards from the front end of the monochrome operating lever 41A, through which the monochrome developer 23A (see reference) is operated. Figure 4 ).

[0028] The front and rear ends of the color operating lever 41B are supported on the side wall 57 via a pair of connecting rods 42B and 43B. The color operating lever 41B, the side wall 57, and the pair of connecting rods 42B and 43B form a parallel linkage mechanism, allowing the color operating lever 41B to swing vertically while maintaining a parallel state. A torsion spring 44B is installed at the base of the connecting rod 42B at the front end of the color operating lever 41B, pressing the color operating lever 41B downwards by the elastic force of the torsion spring 44B. Three mountain-shaped protrusions 49B protrude upwards from the front, middle, and rear ends of the color operating lever 41B, and the three color developers 23B (see reference) are operated via these three protrusions 49B. Figure 4 ).

[0029] Additionally, the developing contact separation apparatus 40 includes a rotating component 51 that moves the monochrome operating lever 41A and the color operating lever 41B. The rotating component 51 is formed by a rotating gear 52, a first cam 53, and a second cam 54, with a pivot point on a pin 58 protruding outward from the middle of the side wall 57. The rotating gear 52 is located on the outer side, the first cam 53 is located in the center, and the second cam 54 is located on the inner side; the rotating gear 52, the first cam 53, and the second cam 54 rotate as a single unit. Power from a drive source (not shown) is transmitted to the rotating gear 52, causing the monochrome operating lever 41A to contact the first cam 53 and the color operating lever 41B to contact the second cam 54.

[0030] The first cam 53 and the second cam 54 are formed in a fan shape, with the central angle of the second cam 54 being larger than that of the first cam 53. When clockwise is taken as the rotation direction, the rear half of the rotation direction of the first cam 53 and the second cam 54 overlap. Due to the difference in the central angles of the first cam 53 and the second cam 54, a two-stage cam is formed that allows the monochrome operating lever 41A and the color operating lever 41B to move independently. Every time the rotating component 51 rotates by 1 / 3, it switches the contact position between the first cam 53 and the monochrome operating lever 41A, and the contact position between the second cam 54 and the color operating lever 41B.

[0031] The rotating component 51 rotates between a first rotating position during non-printing, a second rotating position during color printing, and a third rotating position during monochrome printing. In the first rotating position, the rear halves of the first cam 53 and the second cam 54 are positioned upwards; in the second rotating position, they are positioned downwards; and in the third rotating position, the first cam 53 is positioned downwards, and the front half of the second cam 54 is positioned upwards. The monochrome operating lever 41A and the color operating lever 41B move vertically depending on the rotation position of the first cam 53 and the second cam 54. Furthermore, details regarding the contact separation action of the multiple developers 23A and 23B will be described later.

[0032] Power is transmitted from the drive source to the rotating gear 52 via a spring clutch 61. The bosses of the input gear 62 and output gear 63 of the spring clutch 61 face each other, and coil springs 64 are tightly fitted around the outer periphery of these bosses. The outer side of the coil springs 64 is covered by a cylindrical clutch cover 65, with one end of the coil springs 64 fixed to the output gear 63 and the other end fixed to the clutch cover 65. Three small protrusions 66 are formed at equal intervals on the outer periphery of the clutch cover 65, and claws (not shown) are formed at the front end of a solenoid (not shown) to engage the small protrusions 66.

[0033] When the solenoid's claws disengage from the small protrusion 66, the clutch cover 65 becomes free, and the output gear 63 and the clutch cover 65 rotate as a unit. The coil spring 64 remains engaged, transmitting power from the input gear 62 to the output gear 63. When the solenoid's claws engage the small protrusion 66, the rotation of the clutch cover 65 is restricted, and the clutch cover 65 and the output gear 63 rotate relative to each other. The coil spring 64 is released, and the power transmission from the input gear 62 to the output gear 63 is interrupted. The gear ratio between the output gear 63 and the rotating gear 52 is 1:3; each time the solenoid's claws disengage, the output gear 63 rotates one revolution, and the rotating gear 52 rotates one-third of the way.

[0034] A photoelectric sensor 67 capable of detecting the color operating lever 41B is provided at the rear end of the side wall 57 of the transfer device 13. The color operating lever 41B is detected by blocking the detection light of the photoelectric sensor 67 by the shielding plate 68 at the rear end of the color operating lever 41B. Based on the combination of the detection result of the photoelectric sensor 67 and the number of operations of the solenoid, the first to third rotation positions of the rotating component 51 (non-printing, color printing, and monochrome printing) are identified. Furthermore, the number of operations of the solenoid is reset on the third time, that is, when the rotating component 51 rotates one revolution. The photoelectric sensor 67 is not limited to a transmissive type; a reflective type photoelectric sensor can also be used.

[0035] Reference Figures 4 to 9 The contact separation operation of the developer based on the developing contact separation device is explained. Figure 4 This diagram illustrates the contact separation operation of the developing contact separation device during non-printing operations in this embodiment. Figure 5 This diagram illustrates the contact separation operation of the developing contact separation device during color printing in this embodiment. Figure 6 This diagram illustrates the contact separation operation of the developing contact separation device during monochrome printing in this embodiment. Figure 7 This diagram shows the contact state between the developer and the photosensitive drum in this embodiment. Figure 8 This diagram shows the separation state of the developer and the photosensitive drum in this embodiment. Figure 9 This diagram illustrates an example of the maintenance of the image forming apparatus according to this embodiment.

[0036] like Figure 4 As shown, a monochrome developer 23A is provided at the front end of the transfer device 13, and three color developers 23B are provided behind the developer 23A. A monochrome photosensitive drum 21A is provided next to the developer 23A, and three color photosensitive drums 21B are provided next to the three developers 23B. The developers 23A and 23B are swayably supported on the unit housing 19 (see reference). Figure 9The support parts 76A and 76B are provided in the developer units 23A and 23B. Springs (not shown) are provided in the developer units 23A and 23B, and the spring force acts on the developer units 23A and 23B to press into the photosensitive drums 21A and 21B.

[0037] The monochrome operating lever 41A is located below the developer 23A, and a mountain-shaped protrusion 49A for operating the monochrome developer 23A is provided at the front end of the monochrome operating lever 41A. The color operating lever 41B is located below the developer 23B, and three mountain-shaped protrusions 49B for operating the three color developers 23B are provided at the rear end, middle, and front end of the color operating lever 41B. The monochrome operating lever 41A is pushed against the first cam 53 by the spring force of the torsion spring 44A, and the color operating lever 41B is pushed against the second cam 54 by the spring force of the torsion spring 44B.

[0038] Each time the solenoid is driven, the rotating component 51 rotates 1 / 3, thereby moving the monochrome operating lever 41A via the first cam 53 and the color operating lever 41B via the second cam 54. The monochrome operating lever 41A moves the developer 23A between a contact position where it contacts the photosensitive drum 21A via the protrusion 49A and a separation position where it is separated from the photosensitive drum 21A. The color operating lever 41B moves the three developers 23B between a contact position where they contact the photosensitive drum 21B via the three protrusions 49B and a separation position where they are separated from the three photosensitive drums 21B.

[0039] When not printing, the rotating component 51 stops at the first rotating position. In the first rotating position, the first cam 53 is positioned upwards, and the rear half of the second cam 54 is also positioned upwards. The monochrome operating lever 41A is lifted by the first cam 53 against the spring force of the torsion spring 44A, and the color operating lever 41B is lifted by the rear half of the second cam 54 against the spring force of the torsion spring 44B. The developer 23A moves to the separation position via the protrusion 49A of the monochrome operating lever 41A, and each developer 23B moves to the separation position via the protrusion 49B of the color operating lever 41B.

[0040] Thus, in the first rotation position, the first cam 53 moves the developer 23A to the separation position via the monochrome operating lever 41A, and the second cam 54 moves each developer 23B to the separation position via the color operating lever 41B. Since the developers 23A and 23B are separated from the photosensitive drums 21A and 21B, the developing rollers 72A and 72B do not rotate passively with the photosensitive drums 21A and 21B during the cleaning operation. Therefore, the deterioration of the toner in the developers 23A and 23B is suppressed. When the developers 23A and 23B are in the separation position, the transmission of driving force from the drive source to the developing rollers 72A and 72B is also blocked.

[0041] like Figure 5As shown, during color printing, the rotating component 51 rotates clockwise by 1 / 3 and stops at the second rotating position. In the second rotating position, the first cam 53 is positioned downwards, and the second cam 54 is positioned downwards. The monochrome operating lever 41A is lowered by the spring force of the torsion spring 44A, and the color operating lever 41B is lowered by the spring force of the torsion spring 44B. The protrusion 49A of the monochrome operating lever 41A separates from the developer 23A, and the developer 23A moves to the contact position. The protrusions 49B of the color operating lever 41B separate from the respective developers 23B, and the respective developers 23B move to the contact position.

[0042] Thus, in the second rotational position, the first cam 53 moves the developer 23A to the contact position via the monochrome operating lever 41A, and the second cam 54 moves each developer 23B to the contact position via the color operating lever 41B. Since the developers 23A and 23B are in contact with the photosensitive drums 21A and 21B, toner is applied to the photosensitive drums 21A and 21B from the developing rollers 72A and 72B, and the paper is printed in color. When the developers 23A and 23B are in the contact position, the driving force is transmitted from the drive source to the developing rollers 72A and 72B.

[0043] like Figure 6 As shown, during monochrome printing, the rotating component 51 rotates further clockwise by 1 / 3 and stops at the third rotation position. In the third rotation position, the first cam 53 is positioned downwards, and the front half of the second cam 54 is positioned upwards. The monochrome operating lever 41A is maintained in a downward-downward state by the first cam 53, while the color operating lever 41B is raised by the front half of the second cam 54 against the spring force of the torsion spring 44B. With the developer 23A remaining in the contact position, each developer 23B moves to the separation position via the protrusions 49B of the color operating lever 41B.

[0044] Thus, in the third rotation position, the first cam 53 moves the developer 23A to the contact position via the monochrome operating lever 41A, and the second cam 54 moves each developer 23B to the separation position via the color operating lever 41B. Since each developer 23B is separated from the photosensitive drum 21B, the developer rollers 72B do not rotate passively with the photosensitive drum 21B during monochrome printing. Therefore, the degradation of the toner in each developer 23B is suppressed. With the developer 23A in the contact position and the developer 23B in the separation position, the driving force is transmitted to the developer rollers 72A only from the drive source.

[0045] Furthermore, as described above, the rotational position of the rotating component 51 is identified based on the combination of the detection result of the photoelectric sensor 67 and the number of solenoid operations. When the photoelectric sensor 67 detects the colored operating lever 41B and the solenoid operates once, the rotating component 51 is identified as the first rotational position (see reference). Figure 4When the color operating lever 41B is not detected in the photoelectric sensor 67, and the solenoid operates twice, the rotating component 51 is identified as the second rotation position (see reference). Figure 5 When the color-coded operating lever 41B is detected in the photoelectric sensor 67, and the solenoid has been operated three times, the rotating component 51 is identified as the third rotational position (see reference). Figure 6 ).

[0046] like Figure 7 As shown, a drive gear 73 is provided in the developer unit 23A to drive the developing roller 72 to rotate. The protrusion 49A of the monochrome operation lever 41A separates from the hook portion 74 at the lower part of the developer unit 23A, positioning the developer unit 23A in the contact position, with the developing roller 72A in contact with the photosensitive drum 21A. With the developer unit 23A in the contact position, the drive gear 73 of the developer unit 23A meshes with the transmission gear 75 of the drive source (not shown). The developing roller 72A contacts the photosensitive drum 21A, and power is transmitted from the drive source to the developing roller 72A via the transmission gear 75 and the drive gear 73, causing the developing roller 72A to rotate.

[0047] like Figure 8 As shown, the protrusion 49A of the monochrome operating lever 41A abuts against the hook portion 74 at the lower part of the developer 23A, and the developer 23A moves to the separation position with the support portion 76A as the fulcrum, separating the developing roller 72A from the photosensitive drum 21A. When the developer 23A is in the separation position, the drive gear 73 of the developer 23A disengages from the transmission gear 75 of the drive source. With the developing roller 72A separated from the photosensitive drum 21A, the power from the drive source to the developer 23A is blocked, therefore, the developing roller 72A will not rotate due to power from the photosensitive drum 21A or the drive source.

[0048] With this structure, the photosensitive drum 21A can be separated from the developer unit 23A via the monochrome operating lever 41A, and the transmission and interruption of power to the developer unit 23A can be switched. Furthermore, the operating direction D1 of the monochrome operating lever 41A is along the contact-separation direction D2 between the photosensitive drum 21A and the developer unit 23A. Thus, the developing unit 23A can be smoothly moved to the separation position via the monochrome operating lever 41A. While the contact-separation operation between the developer unit 23A and the photosensitive drum 21A has been described, the contact-separation operation between the developer unit 23B and the photosensitive drum 21B is the same.

[0049] like Figure 9As shown, the unit housing 19 is equipped with a monochrome developer 23A, three color developers 23B, a monochrome photosensitive drum 21A, and three color photosensitive drums 21B. During maintenance, similar to color printing, the color operation lever 41B and the monochrome operation lever 41A are lowered, and the protrusions 49A and 49B are positioned lower than the developers 23A and 23B. The unit housing 19 is pulled forward from the housing 10, and when viewed from the side, a pull-out trajectory 77 parallel to the extending direction of the color operation lever 41B and the monochrome operation lever 41A is traced on the lower surface of the unit housing 19.

[0050] Thus, even when not printing, during maintenance, the color operating lever 41B and the monochrome operating lever 41A are lowered in the same manner as during color printing. With the developers 23A and 23B in the contact position via the monochrome operating lever 41A and the color operating lever 41B, the monochrome operating lever 41A and the color operating lever 41B move away from the pull-out trajectory 77 of the unit housing 19. Therefore, when maintaining the components on the unit housing 19, the pull-out of the unit housing 19 is not obstructed by the monochrome operating lever 41A and the color operating lever 41B.

[0051] According to this embodiment, during non-printing periods, each developer 23A and 23B is separated from each photosensitive drum 21 via the monochrome operation lever 41A and the color operation lever 41B. During color printing, each developer 23A and 23B is in contact with each photosensitive drum 21A and 21B via the monochrome operation lever 41A and the color operation lever 41B. During monochrome printing, the developer 23B is separated from the color photosensitive drum 21B via the color operation lever 41B. In this way, the developer 23, which is not used during monochrome printing and non-printing periods, is not rotated by the photosensitive drum 21, thus suppressing the deterioration of the toner in the developer 23. Furthermore, space-saving design of the developer contact separation device 40 is achieved, suppressing the enlargement of the image forming apparatus 1.

[0052] Furthermore, in this embodiment, a monochrome operation lever 41A and a color operation lever 41B are exemplified as monochrome operation and color operation components, respectively, but the monochrome operation and color operation components are not limited to lever shapes. The monochrome operation component only needs to be able to move the monochrome developer between a contact position and a separation position, and the color operation component only needs to be able to move the color developer between a contact position and a separation position.

[0053] In addition, in this embodiment, the rotating member 51 has a fan-shaped first cam 53 and a second cam 54, but the rotating member 51 is not limited to this shape, as long as it is formed so that the developer can be moved by the monochrome operation member and the color operation member.

[0054] In addition, in this embodiment, the transmission of power from the drive source to the developer is switched and blocked by the contact separation between the drive gear of the developer and the transmission gear of the drive source, but the method of switching the transmission and blocking of power from the drive source to the developer is not particularly limited.

[0055] In addition, in this embodiment, the operation direction of the monochrome operation component and the color operation component is along the contact separation direction between the photosensitive drum and the developer, but the operation direction of the monochrome operation component and the color operation component does not need to be along the contact separation direction between the photosensitive drum and the developer.

[0056] In this embodiment, a printer is exemplified as the image forming apparatus 1, but the device is not limited to this structure. The image forming apparatus 1 can be a multifunction printer, in addition to a copier and a fax machine, which combines printing, copying, and faxing functions.

[0057] Furthermore, this embodiment has been described, but as other embodiments, the above embodiments and variations may be combined in whole or in part.

[0058] Furthermore, the technology of the present invention is not limited to the above-described embodiments, and various changes, substitutions, and modifications can be made without departing from the spirit of the technical concept. Moreover, if the technical concept can be realized in other ways through technological advancements or derived technologies, this method can also be used. Therefore, the claims cover all embodiments that can be included within the scope of the technical concept.

[0059] This invention is not limited to the structure of the above-described embodiments and can be modified in various ways. Figures 1 to 7 The structure and processing described in the above embodiments are merely one embodiment of the present invention and do not imply that the present invention is limited to this structure and processing.

Claims

1. A developing contact separation apparatus, characterized in that, have: A monochrome operating component that moves the monochrome developer between a contact position in contact with the monochrome photosensitive drum and a separation position away from the monochrome photosensitive drum; A color operating component that moves the color developer between a contact position with the color photosensitive drum and a separation position away from the color photosensitive drum; and The rotating component rotates between a first rotating position when not printing, a second rotating position when printing in color, and a third rotating position when printing in monochrome. At the first rotation position, the rotating component moves the monochrome developer to the separation position via the monochrome operating component, and moves the color developer to the separation position via the color operating component. In the second rotation position, the rotating component moves the monochrome developer to the contact position via the monochrome operating component, and moves the color developer to the contact position via the color operating component. In the third rotation position, the rotating component moves the monochrome developer to the contact position via the monochrome operation component, and moves the color developer to the separation position via the color operation component; The rotating component has a first cam that contacts the monochrome operating component and a second cam that contacts the color operating component. In the first rotational position, the first cam moves the monochrome developer to the separation position via the monochrome operating component, and the second cam moves the color developer to the separation position via the color operating component. In the second rotational position, the first cam moves the monochrome developer to the contact position via the monochrome operating component, and the second cam moves the color developer to the contact position via the color operating component. In the third rotational position, the first cam moves the monochrome developer to the contact position via the monochrome operating component, and the second cam moves the color developer to the separation position via the color operating component.

2. The developing contact separation apparatus according to claim 1, characterized in that, At the contact position, power is transmitted from the drive source to both the monochrome developer and the color developer. In the separated position, the power from the drive source to the monochrome developer and the color developer is blocked.

3. The developing contact separation apparatus according to claim 1, characterized in that, The operating direction of the monochrome operation component is along the contact separation direction between the monochrome photosensitive drum and the monochrome developer. The operating direction of the color operating component is along the contact separation direction between the color photosensitive drum and the color developer.

4. The developing contact separation apparatus according to claim 1, characterized in that, The monochrome photosensitive drum, the monochrome developer, the color photosensitive drum, and the color developer are housed in a single housing. With the monochrome operating component moving the monochrome developer to the contact position and the color operating component moving the color developer to the contact position, the monochrome operating component and the color operating component leave the pull-out trajectory traced on the lower surface of the housing.

5. The developing contact separation apparatus according to claim 1, characterized in that, The front and rear ends of the monochrome operation component are supported on the side wall of the transfer device via a pair of connecting rods, and the front and rear ends of the color operation component are supported on the side wall of the transfer device via a pair of connecting rods. Thus, a parallel linkage mechanism that allows the monochrome operation component and the color operation component to swing vertically while maintaining a parallel state is respectively formed on the monochrome operation component and the color operation component.

6. An image forming apparatus, characterized in that, have: The developing contact separation apparatus according to any one of claims 1 to 5; and An image forming unit is used to form an image on a recording medium.

Images