JP6817535B2 - Image forming device and image forming unit - Google Patents

Description

The present invention relates to an image forming apparatus and an image forming unit.

In image forming devices such as copiers and printers, in order to facilitate replacement work and maintenance at the time of failure or the end of life, a charging device, a developing device, a cleaning device, etc. are used as a support frame for supporting the image carrier. On the other hand, a detachable structure is known.

For example, Patent Document 1 (Japanese Unexamined Patent Publication No. 2011-97076) describes a configuration in which a cleaning module for cleaning the surface of a photoconductor can be attached to and detached from a unit frame supporting the photoconductor. ing. This cleaning module is provided with a cleaning blade that removes toner remaining on the surface of the photoconductor, a leveling blade that evens out the lubricant applied to the surface of the photoconductor, and the like, and these members can be removed integrally. It is configured to be possible.

By the way, in the attachment / detachment unit provided with the cleaning blade, the leveling blade, etc. as described above, when the attachment / detachment unit is removed, the residual toner blocked by the contact member such as the cleaning blade or the leveling blade that comes into contact with the photoconductor. And deposits such as excess lubricant are present on the photoconductor. Such deposits remain on the surface of the photoconductor even if the detachable unit is removed. Therefore, when a new detachable unit is attached, the deposits are formed between the contact member (cleaning blade, leveling blade, etc.) and the photoconductor. It may be caught between.

Then, if deposits are sandwiched between the contact member and the photoconductor, the contact member will not be in a normal contact state with the photoconductor, and thus the required original function cannot be fully exhibited. There are challenges.

In order to solve the above problems, in the present invention, the position changing mechanism is arranged in a first position in which the detachable unit is attached and a second position in which the detachable unit is removed. The detachable unit has a moving member that can move to and from a position, and an engaging portion that is provided on the moving member and can be engaged with an image carrier gear provided on the image carrier. When the moving member moves from the second position to the first position in conjunction with the mounting operation of the image carrier, the engaging portion engages with the image carrier gear and the image carrier gear. The image carrier is rotated in the opposite direction by rotating the image carrier, and the engaging portion is in an upright state capable of engaging with the image carrier gear and does not engage with the image carrier gear. The engaging portion is configured to be switchable to a collapsed state, and when the moving member moves from the second position to the first position, the engaging portion is held in the upright state, and the moving member moves to the first position. When moving from the position 1 to the second position, the state is switched to the collapsed state .

According to the present invention, the image carrier is rotated in the direction opposite to the rotation direction at the time of image formation by the position changing mechanism from the state before the attachment / detachment unit is attached to the state in which the attachment / detachment unit is attached. This reverse rotation can shift the position of the deposits on the image carrier. As a result, it is possible to prevent the contact member from sandwiching the deposit between the image carrier and the image carrier when the attachment / detachment unit is attached.

It is a schematic block diagram of the image forming apparatus which concerns on one Embodiment of this invention. It is a schematic block diagram of the image formation unit which concerns on this embodiment. It is a figure for demonstrating the problem at the time of exchanging a cleaning unit. It is a figure for demonstrating the problem at the time of exchanging a cleaning unit. It is a figure for demonstrating the problem at the time of exchanging a cleaning unit. It is a figure for demonstrating the problem at the time of exchanging a cleaning unit. It is a figure for demonstrating the problem at the time of exchanging a cleaning unit. It is a schematic block diagram of the position change mechanism which concerns on 1st Embodiment of this invention. It is a figure for demonstrating the operation of the position change mechanism which concerns on 1st Embodiment. It is a figure for demonstrating the operation of the position change mechanism which concerns on 1st Embodiment. It is a figure for demonstrating the operation of the position change mechanism which concerns on 1st Embodiment. It is a figure for demonstrating the operation of the position change mechanism which concerns on 1st Embodiment. It is a figure for demonstrating the operation of the position change mechanism which concerns on 1st Embodiment. It is a figure for demonstrating the preferable reverse rotation amount of a photoconductor. It is a schematic block diagram of the position change mechanism which concerns on 2nd Embodiment of this invention. It is a figure for demonstrating the operation of the position change mechanism which concerns on 2nd Embodiment. It is a figure for demonstrating the operation of the position change mechanism which concerns on 2nd Embodiment. It is a figure for demonstrating the operation of the position change mechanism which concerns on 2nd Embodiment. It is a figure for demonstrating the operation of the position change mechanism which concerns on 2nd Embodiment. It is a figure for demonstrating the operation of the position change mechanism which concerns on 2nd Embodiment. It is a schematic block diagram of the position change mechanism which concerns on 3rd Embodiment of this invention. It is a figure for demonstrating the operation of the position change mechanism which concerns on 3rd Embodiment. It is a figure for demonstrating the operation of the position change mechanism which concerns on 3rd Embodiment. It is a figure for demonstrating the operation of the position change mechanism which concerns on 3rd Embodiment. It is a figure for demonstrating the operation of the position change mechanism which concerns on 3rd Embodiment. It is a schematic block diagram of the position change mechanism which concerns on 4th Embodiment of this invention. It is a figure for demonstrating the operation of the position change mechanism which concerns on 4th Embodiment. It is a figure for demonstrating the operation of the position change mechanism which concerns on 4th Embodiment. It is a figure for demonstrating the structure and operation of the position change mechanism which concerns on 5th Embodiment of this invention. It is a figure for demonstrating the structure and operation of the position change mechanism which concerns on 5th Embodiment.

Hereinafter, the present invention will be described with reference to the accompanying drawings. In each drawing for explaining the present invention, components such as members and components having the same function or shape will be described once by giving the same reference numerals as much as possible. Omit.

FIG. 1 is a schematic configuration diagram of an image forming apparatus according to an embodiment of the present invention.
The image forming apparatus 100 shown in FIG. 1 includes four image forming units 1Y, 1C, 1M, and 1Bk that are detachable from the image forming apparatus main body. Each image forming unit 1Y, 1C, 1M, 1Bk has the same configuration except that it contains developeres of different colors of yellow, cyan, magenta, and black corresponding to the color separation components of the color image. Specifically, each image forming unit 1Y, 1C, 1M, 1Bk is formed on a drum-shaped photoconductor 2 as an image carrier, a charging device 3 for charging the surface of the photoconductor 2, and a surface of the photoconductor 2. A developing device 4 that supplies toner as a developing agent to form a toner image, a cleaning device 5 that cleans the surface of the photoconductor 2, and a lubricant supply device 6 that supplies a lubricant to the surface of the photoconductor 2. Be prepared.

Further, the image forming apparatus 100 is formed on each photoconductor 2, an exposure apparatus 7 that exposes the surface of each photoconductor 2 to form an electrostatic latent image, a paper feeding device 8 that supplies paper as a recording medium, and each photoconductor 2. A transfer device 9 for transferring the toner image to the paper and a fixing device 10 for fixing the toner image transferred to the paper are provided.

The paper feed device 8 includes a paper feed cassette 11 for accommodating paper and a paper feed roller 12 for feeding paper from the paper feed cassette 11.

The transfer device 9 includes an endless intermediate transfer belt 13 as an intermediate transfer body stretched by a plurality of rollers, and four primary transfer members for transferring a toner image on each photoconductor 2 to the intermediate transfer belt 13. It has a primary transfer roller 14 and a secondary transfer roller 15 as a secondary transfer member that transfers the toner image transferred on the intermediate transfer belt 13 to paper. Each of the plurality of primary transfer rollers 14 is in contact with the photoconductor 2 via the intermediate transfer belt 13. As a result, the intermediate transfer belt 13 and each photoconductor 2 come into contact with each other, and a primary transfer nip is formed between them. On the other hand, the secondary transfer roller 15 is in contact with one of the rollers for tensioning the intermediate transfer belt 13 via the intermediate transfer belt 13. As a result, a secondary transfer nip is formed between the secondary transfer roller 15 and the intermediate transfer belt 13.

The fixing device 10 comprises a fixing roller 16 as a fixing member that is heated by a heating means such as a halogen heater to fix an image on paper, and a pressure roller 17 as a pressure member that pressurizes the fixing roller 16. Have. The fixing roller 16 and the pressure roller 17 are in contact with each other, and a fixing nip is formed between the fixing rollers 16 and 17.

In addition, a paper transport path 20 for transporting the paper fed from the paper feed cassette 11 is formed in the image forming apparatus 100. A pair of timing rollers 18 are provided on the way from the paper feed roller 12 to the secondary transfer nip (secondary transfer roller 15) in the paper transport path 20.

Subsequently, the image forming operation of the image forming apparatus will be described with reference to FIG.
When instructed to start the image drawing operation, each photoconductor 2 is rotationally driven counterclockwise in the drawing, and the surface of each photoconductor 2 is charged to a uniform high potential by the charging device 3. Next, the exposure device 7 exposes the surface of each photoconductor 2 based on the image information of the document read by the document reader or the print information instructed to print from the terminal, so that the potential of the exposed portion is increased. It is lowered to form an electrostatic latent image. Then, toner is supplied from each developing device 4 to the electrostatic latent image, and a toner image is formed on each photoconductor 2.

Further, in the transfer device 9, the intermediate transfer belt 13 is rotationally driven, and a constant voltage or a constant current controlled voltage having a polarity opposite to the charging polarity of the toner is applied to each primary transfer roller 14. As a result, a transfer electric field is formed at the primary transfer nip between each primary transfer roller 14 and each photoconductor 2. Then, the toner images of each color on each photoconductor 2 are sequentially superimposed and transferred on the intermediate transfer belt 13 by the transfer electric field in the primary transfer nip. Thus, a full-color toner image is supported on the intermediate transfer belt 13. On the other hand, each photoconductor 2 that has finished transferring the toner image is cleaned by the cleaning device 5, and then the lubricant is supplied by the lubricant supply device 6.

Further, in the paper feed device 8, the paper feed roller 12 starts rotational driving, and the paper is fed from the paper feed cassette 11. After being temporarily stopped by the timing roller 18, the fed paper is fed to the secondary transfer nip at the timing when the toner image on the intermediate transfer belt 13 reaches the secondary transfer nip. At this time, a transfer voltage having a polarity opposite to the toner charging polarity of the toner image is applied to the secondary transfer roller 15, and a transfer electric field is formed in the secondary transfer nip. Then, the toner images on the intermediate transfer belt 13 are collectively transferred onto the paper by the transfer electric field formed in the secondary transfer nip.

The paper on which the toner image is transferred is conveyed to the fixing device 10. Then, the paper is heated and pressurized by passing through the fixing nip between the fixing roller 16 and the pressure roller 17, and the toner image is fixed on the paper. After that, the paper is ejected to the outside of the device, and a series of image drawing operations is completed.

The above description is an image forming operation when forming a full-color image on a recording medium. However, one of four image forming units may be used to form a monochromatic image, or two or three images may be formed. It is also possible to use the unit to form a two-color or three-color image.

FIG. 2 is a schematic configuration diagram of an image forming unit according to the present embodiment.
Since the above four image forming units 1Y, 1M, 1C, and 1Bk have the same configuration except that they accommodate toners of different colors, each image forming unit 1 shown in FIG. 2 is taken as an example. The configuration of the units 1Y, 1M, 1C, and 1Bk will be described.

As shown in FIG. 2, the charging device 3 has a charging roller 30 as a charging member for charging the surface of the photoconductor 2. The charging roller 30 is in contact with the surface of the photoconductor 2, and the surface of the photoconductor 2 is uniformly charged by applying a predetermined voltage from the power supply unit of the image forming apparatus main body.

The developing apparatus 4 has a developing roller 40 as a developing agent carrier that supplies toner to the photoconductor 2. The developing roller 40 supports the toner contained in the developing apparatus 4 on the surface and rotates to transfer the toner to the contact point with the photoconductor 2 and supply the toner onto the photoconductor 2.

The cleaning device 5 has a cleaning blade 50 as a cleaning member for removing toner remaining on the surface of the photoconductor 2. The cleaning blade 50 is a longitudinal member made of a rubber material such as urethane rubber, and one side extending in the longitudinal direction is in contact with the surface of the photoconductor 2 at a predetermined pressure. Further, the cleaning blade 50 is arranged in the counter direction with respect to the photoconductor 2 (so that the end portion of the cleaning blade 50 in contact with the photoconductor 2 faces the direction opposite to the rotation direction of the photoconductor 2). There is. When the photoconductor 2 rotates during image formation, deposits such as residual toner adhering to the surface of the photoconductor 2 are mechanically scraped off by the cleaning blade 50 to be removed. Here, as the deposits adhering to the surface of the photoconductor 2, in addition to the residual toner, paper dust generated from the paper, discharge products generated on the photoconductor 2 during discharge by the charging roller 30, and toner are added. There are additives and the like.

The lubricant supply device 6 is supplied to the surface of the photoconductor 2, a solid lubricant 60, a brush-shaped lubricant supply roller 61 as a lubricant supply member for supplying the lubricant 60 to the surface of the photoconductor 2. It has a leveling blade 62 as a lubricant leveling member for thinning the lubricant.

As the lubricant 60, one made of a fatty acid metal salt, a fluororesin or the like can be used, but the fatty acid metal salt is particularly preferable in that it has a large effect of reducing the friction of the photoconductor 2. Examples of the fatty acid metal salt include fatty acid metal salts of linear hydrocarbons such as myristic acid, palmitic acid, stearic acid, and aleic acid, and examples of the metal include lithium, magnesium, calcium, strontium, zinc, and cadmium. Aluminum, cerium, titan, magnesium stearate, aluminum stearate, iron stearate and the like are preferable, and zinc stearate is particularly preferable.

The lubricant supply roller 61 is in contact with the surface of the photoconductor 2. When the photoconductor 2 rotates, the lubricant supply roller 61 rotates in the rotational direction with respect to the rotation direction of the photoconductor 2, so that the lubricant 60 is scraped off and supplied to the surface of the photoconductor 2.

The leveling blade 62 is a longitudinal member made of a rubber material such as urethane rubber, and one side extending in the longitudinal direction is in contact with the surface of the photoconductor 2 at a predetermined pressure. Further, the leveling blade 62 is arranged in the counter direction with respect to the photoconductor 2 (so that the end portion of the leveling blade 62 in contact with the photoconductor 2 faces the direction opposite to the rotation direction of the photoconductor 2). Has been done. When the photoconductor 2 rotates, the lubricant supplied onto the photoconductor 2 by the lubricant supply roller 61 passes through the leveling blade 62 to be thinned and applied.

Further, as shown in FIG. 2, in the present embodiment, the lubricant supply device 6 is arranged on the downstream side of the cleaning device 5 in the rotation direction of the photoconductor 2 starting from the primary transfer nip N1. Therefore, the lubricant is supplied to the surface of the photoconductor 2 after being cleaned by the cleaning blade 50 by the lubricant supply roller 61. As a result, the lubricant is stably and evenly supplied without being affected by the deposits on the photoconductor 2.

Further, each member constituting the cleaning device 5 and each member constituting the lubricant supply device 6 are held in a common unit housing 201. Further, the common unit housing 201 is configured to be attachable to and detachable from the support frame 22 that supports the photoconductor 2, the charging device 3, and the developing device 4. That is, the cleaning device 5 and the lubricant supply device 6 are configured to be attached to and detachable from the support frame 22 as one detachable unit 200 (hereinafter, referred to as “cleaning unit”). Reference numerals 24 and 25 in FIG. 2 are groove-shaped guide portions provided on the support frame body 22. The cleaning unit 200 is configured to be replaceable by being attached to and detached from the support frame 22 along these guide portions 24 and 25.

Here, problems when replacing the cleaning unit 200 will be described.

When the image forming unit is used to some extent, as shown in FIG. 3, the cleaning blade 50 and the leveling blade 62 block residual toner, lubricant, and the like, so that the cleaning blade 50 and leveling blade 50 and the leveling blade 2 are on the surface of the photoconductor 2. There is a deposit A blocked by each contact member of the blade 62. Then, as shown in FIG. 4, such a deposit A remains on the surface of the photoconductor 2 not a little even when the cleaning unit 200A is removed. Therefore, as shown in FIG. 5, when a new cleaning unit 200B is attached, the deposit A may be sandwiched between the photoconductor 2 and the cleaning blade 50 or the leveling blade 62.

When the deposit A is sandwiched between these blades 50 and 62 and the photoconductor 2, as shown in FIG. 6, the blades 50 and 62 and the photoconductor A are sandwiched on both sides of the portion where the deposit A is sandwiched. A gap S is formed between the two. Then, when the image forming operation is started in this state, the residual toner, the lubricant, or the deposit B such as the additive contained therein slips through the gap S between the blades 50 and 62 and the photoconductor 2. It ends up. As a result, as shown in FIG. 7, the adhering matter B that has slipped through may adhere to the surface of the charging roller 30 to cause charging failure, resulting in an abnormal image.

As a measure to prevent such a problem, for example, when the cleaning unit is removed, a method of wiping off the deposits on the photoconductor with a waste cloth or the like can be considered. However, it is conceivable that this method increases the surface friction coefficient of the photoconductor by wiping. In that case, the rotational load of the photoconductor increases, which may cause the blade to curl.

Another method is to allow the operator or user to rotate the photoconductor in the direction opposite to the rotation direction at the time of image formation and move it to a position where deposits are not pinched before installing a new cleaning unit. Be done. However, in this method, if the operator or the user mistakenly rotates the photoconductor in the rotation direction at the time of image formation, deposits may adhere to the charging roller or the developing roller. Furthermore, there is a risk of forgetting to perform the rotation operation. Further, even if the photoconductor is rotated without making a mistake in the rotation direction, the amount of rotation cannot be adjusted accurately, so that there remains anxiety as to whether or not the pinching of deposits can be reliably prevented.

Therefore, in the image forming apparatus according to the embodiment of the present invention, a position changing mechanism for rotating the photoconductor to change the position in the rotation direction is provided in order to surely prevent pinching of deposits. ..

FIG. 8 is a schematic configuration diagram of a position changing mechanism according to the first embodiment of the present invention.
As shown in FIG. 8, the position changing mechanism 70 according to the first embodiment includes a moving member 71, an engaging portion 72 provided on the moving member 71, and a moving member that urges the moving member 71 in one direction. It has a coil spring 73 as a force means.

The moving member 71 is provided so as to be reciprocally movable with respect to the support frame body 22 in the linear direction of the arrow C1 direction and the arrow C2 direction in the drawing. A receiving portion 71a for receiving one end of the coil spring 73 is provided at one end of the moving member 71, and an engaging portion 72 is provided at the other end of the moving member 71.

The coil spring 73 is held in a compressed state between the receiving portion 71a provided on the moving member 71 and the receiving portion 22a provided on the support frame body 22. As a result, the moving member 71 is urged in the direction of arrow C1 in the drawing.

The engaging portion 72 has a plurality of protrusions 72a for engaging with the photoconductor gear (image carrier gear) 23 provided on the photoconductor 2 to rotate the photoconductor gear 23. Further, the engaging portion 72 is provided so as to be rotatable with respect to the moving member 71 in the direction of arrow D1 and the direction of arrow D2 in the drawing. As a result, the engaging portion 72 is configured to be switchable between an upright state shown by a solid line in the figure and a fallen state shown by a two-dot chain line. Further, the fulcrum 74, which is the center of rotation of the engaging portion 72, is provided with a torsion coil spring 75 as an engaging portion urging means for urging the engaging portion 72 in the upright state (direction of arrow D1). There is. Further, the engaging portion 72 is provided with a stopper portion 72b for holding the engaging portion 72 in an upright state against the urging force of the torsion coil spring 75. Therefore, the engaging portion 72 is usually held so as to be in an upright state.

Subsequently, the operation of the position changing mechanism according to the first embodiment will be described.
As shown in FIG. 9, when the cleaning unit 200A is attached to the support frame body 22, the moving member 71 is pushed diagonally downward to the left in the drawing by the cleaning unit 200A. Specifically, the pushing portion 201a provided in the unit housing 201 of the cleaning unit 200A presses the receiving portion 71a of the moving member 71 against the urging force of the coil spring 73, so that the moving member 71 is pushed diagonally downward to the left. It is arranged in the position (first position). Further, in this state, the engaging portion 72 is held in an upright state, but the engaging portion 72 is arranged at a position where it does not engage (or does not contact) with the photoconductor gear 23. By arranging the engaging portion 72 at a position where it does not engage with the photoconductor gear 23 in this way, even if the photoconductor gear 23 rotates together with the photoconductor 2 during image formation, the engaging portion 72 and the The photoconductor gear 23 is prevented from being damaged.

As shown in FIG. 10, when the cleaning unit 200A is moved from the state shown in FIG. 9 in the direction of removing the cleaning unit 200A, the pushing portion 201a moves in the direction opposite to the direction in which the moving member 71 is pushed, so that the moving member 71 is moved to the coil spring 73. It is urged and moves diagonally upward to the right in the figure (in the direction of arrow C1 in the figure). Further, at this time, when the engaging portion 72 comes into contact with the photoconductor gear 23, it rotates counterclockwise in the figure (in the direction of arrow D2 in the figure) and is switched to the tilted state. As a result, the engaging portion 72 is not engaged with the photoconductor gear 23. As a result, even if the moving member 71 moves diagonally upward to the right, the engaging portion 72 does not engage with the photoconductor gear 23, so that the photoconductor gear 23 does not rotate.

The reason why the engaging portion is not engaged with the photoconductor gear in this way is to prevent the photoconductor from rotating in the rotation direction at the time of image formation. That is, if the engaging portion is engaged with the photoconductor gear without being tilted, the photoconductor is rotated in the rotation direction (counterclockwise in FIG. 10) at the time of image formation as the moving member moves. Therefore, deposits on the photoconductor may adhere to the charging roller. In addition, if the deposit moves to the charging roller side, even if the photoconductor is rotated in the reverse direction later, the deposit will only return to its original position and cannot be moved to a position where it will not be pinched by the cleaning blade or leveling blade. Because. Therefore, in this way, when the cleaning unit is removed, the photoconductor is prevented from rotating to prevent the deposits from adhering to the charging roller, and the effect of the reverse rotation of the photoconductor to be performed later can be obtained. ..

As shown in FIG. 11, when the cleaning unit 200A is removed, the pushing (contact) of the moving member 71 by the pushing portion 201a is released, and the moving member 71 is opposite to the pushed position (first position). It is placed in a side position (second position). Further, in this state, the engaging portion 72 is rotated clockwise (in the direction of arrow D1 in the drawing) by the torsion coil spring 75 and returned to the upright state.

Next, as shown in FIG. 12, when a new cleaning unit 200B is attached, the receiving portion 71a of the moving member 71 is pressed by the pushing portion 201a of the cleaning unit 200B, so that the moving member 71 moves diagonally downward to the left in the drawing. Move in the direction of arrow C2 in the figure. At this time, the engaging portion 72 in the upright state engages with the photoconductor gear 23 as the moving member 71 moves. As a result, the photoconductor gear 23 is rotated clockwise in the drawing, and the photoconductor 2 is rotated in the direction opposite to the rotation direction at the time of image drawing.

Then, as shown in FIG. 13, when the cleaning unit 200B is attached, the moving member 71 is arranged at the pushed position (first position), and the engaging portion 72 is engaged with the photoconductor gear 23. Is released. As a result, the rotation of the photoconductor 2 is stopped.

As described above, in the present embodiment, the position of the deposit on the photoconductor can be shifted by rotating (reverse rotation) the photoconductor in the direction opposite to the rotation direction at the time of image formation when the cleaning unit is attached. Yes (see FIG. 13). As a result, it is possible to prevent the deposits from being pinched by the cleaning blade or the leveling blade, so that residual toner, excess lubricant, etc. pass between these blades and the photoconductor and adhere to the charging roller and the developing roller. Can be prevented. In addition, since the cleaning blade and leveling blade can be placed in a normal contact state with the photoconductor (without pinching of deposits), the cleaning blade and leveling blade can fully exert their original functions. Can be done.

Further, by rotating the photoconductor in the reverse direction by the position changing mechanism, the amount of rotation of the photoconductor can be adjusted to a constant amount as compared with the case where the operator or the user directly rotates the photoconductor in the reverse direction. Therefore, there is no variation in the amount of rotation, and it is possible to reliably prevent the sediment from being pinched. Further, according to the configuration of the position changing mechanism according to the present embodiment, the position changing mechanism rotates the photoconductor in the reverse direction in conjunction with the mounting operation of the cleaning unit, so that the operability is excellent and there is a risk of forgetting to perform the reverse rotation operation. Absent.

The amount of rotation when the photoconductor 2 is rotated in the reverse direction is preferably set to a small amount of rotation and a rotation amount that can reliably prevent pinching. Specifically, in FIG. 14, assuming that the amount of rotation (rotation angle) when the photoconductor 2 is rotated in the reverse direction is α, the amount of rotation α is from the contact position E of the leveling blade 62 with respect to the photoconductor 2 to the photoconductor 2. It is preferable that the rotation angle θ is set smaller than the rotation angle θ until the contact position E2 of the cleaning blade 50 with respect to the photoconductor 2 is reached in the reverse rotation direction. By setting in this way, when the photoconductor 2 is rotated in the reverse direction, the deposit A is leveled and kept away from the contact position E1 of the blade 62, but does not reach the contact position E2 of the cleaning blade 50. Can be done. That is, it is possible to prevent the deposit A deposited at the contact position E2 of the leveling blade 62 from being pinched by the cleaning blade 50 at the point where the photoconductor 2 is moved by the reverse rotation. Further, since the amount of rotation of the photoconductor 2 can be small, the number of protrusions of the engaging portion engaged with the photoconductor gear can be reduced, which is advantageous for miniaturization.

Further, by providing the position changing mechanism on the support frame as in the present embodiment, the cleaning unit can be replaced while the position changing mechanism remains on the support frame. That is, the replacement cost of consumables can be reduced by not providing the position changing mechanism in the cleaning unit which is a replacement product.

Hereinafter, embodiments different from the above embodiments will be described.

FIG. 15 is a schematic configuration diagram of a position changing mechanism according to a second embodiment of the present invention.
As shown in FIG. 15, the position changing mechanism 70 according to the second embodiment has a moving member 71, an engaging portion 72, and a coil spring 73, as in the first embodiment. However, here, the engaging portion 72 is not rotatably provided with respect to the moving member 71 and is fixed in an upright state. Further, in the second embodiment, the photoconductor gear 23 is connected to the photoconductor 2 via a one-way clutch 26 as a one-way rotational driving force transmitting means, and only the one-way rotational driving force of the photoconductor gear 23 is applied. It is transmitted to the photoconductor 2. Specifically, in FIG. 15, the one-way clutch 26 transmits only the rotational driving force when the photoconductor gear 23 is rotated in the direction of the arrow F1 in the drawing to the photoconductor 2, and the photoconductor gear 23 is shown in the drawing. When it is rotated in the direction of the arrow F2, the rotational driving force is not transmitted to the photoconductor 2. Other configurations are the same as those in the first embodiment.

Subsequently, the operation of the position changing mechanism according to the second embodiment will be described.
As shown in FIG. 16, in a state where the cleaning unit 200A is attached to the support frame body 22, the position where the moving member 71 is pushed by the cleaning unit 200A (first) as in the first embodiment. Position). Further, in this state, the engaging portion 72 is arranged at a position where it does not engage (or does not contact) with the photoconductor gear 23.

When the cleaning unit 200A is moved from the state shown in FIG. 16 in the direction of removing the cleaning unit 200A, the moving member 71 is urged by the coil spring 73 and moves diagonally upward to the right (in the direction of arrow C1 in the figure). To do. At this time, the engaging portion 72 engages with the photoconductor gear 23 to rotate the photoconductor gear 23 counterclockwise (in the direction of arrow F2 in the drawing). However, the rotational driving force of the photoconductor gear 23 at this time is not transmitted from the one-way clutch 26 to the photoconductor 2. Therefore, the photoconductor 2 does not rotate when the cleaning unit is removed.

As described above, in the second embodiment, the one-way clutch is used to prevent the photoconductor from rotating when the cleaning unit is removed, and as in the first embodiment, the photoconductor rotates to form a charging roller. In addition to preventing the adhesion of deposits, the effect of reverse rotation of the photoconductor, which will be performed later, can be obtained.

As shown in FIG. 18, when the cleaning unit 200A is removed, the pushing (contact) of the moving member 71 by the pushing portion 201a is released, and the moving member 71 is different from the pushed position (first position). It is placed in the opposite position (second position). At this time, the engaging portion 72 is arranged at a position retracted from the photoconductor gear 23.

Next, as shown in FIG. 19, when a new cleaning unit 200B is attached, the receiving portion 71a of the moving member 71 is pressed by the pushing portion 201a of the cleaning unit 200B, so that the moving member 71 moves diagonally downward to the left in the drawing. Move in the direction of arrow C1 in the figure. Further, as the moving member 71 moves, the engaging portion 72 engages with the photoconductor gear 23. Then, as the moving member 71 moves further, the photoconductor gear 23 is rotated clockwise in the figure (in the direction of the arrow F1 in the figure). The rotational driving force of the photoconductor gear 23 at this time is transmitted from the one-way clutch 26 to the photoconductor 2. As a result, the photoconductor 2 rotates in the direction opposite to the rotation direction at the time of image formation.

Then, as shown in FIG. 20, when the cleaning unit 200B is attached, the moving member 71 is arranged at the pushed position (first position), and the engaging portion 72 is engaged with the photoconductor gear 23. Is released. As a result, the rotation of the photoconductor 2 is stopped.

As described above, also in the second embodiment, similarly to the first embodiment, the photoconductor is rotated in the direction opposite to the rotation direction at the time of image formation when the cleaning unit is attached, and the position of the deposit on the photoconductor is located. Can be shifted. This makes it possible to prevent the deposits from being pinched by the cleaning blade or the leveling blade. Further, since the reverse rotation operation of the photoconductor can be performed in conjunction with the attachment operation of the cleaning unit, the operability is excellent and there is no risk of forgetting to perform the reverse rotation operation. Further, since the amount of rotation when the photoconductor is rotated in the reverse direction can be adjusted to a constant amount, it is possible to reliably prevent the deposition from being pinched. Further, also in the present embodiment, it is desirable that the amount of rotation when the photoconductor is rotated in the reverse direction is set to the same amount of rotation as described in FIG.

In the present embodiment, the one-way clutch is used as a measure to prevent the photoconductor from rotating when the cleaning unit is removed, but it is also possible to use an electromagnetic clutch instead of the one-way clutch. However, when an electromagnetic clutch is used, an installation space for wiring for power supply is required, and the clutch mounting structure is complicated. On the other hand, when a one-way clutch having only a mechanical configuration is used as in the present embodiment, space can be saved, the mounting structure can be simplified, and the degree of freedom in design is improved.

FIG. 21 is a schematic configuration diagram of a position changing mechanism according to a third embodiment of the present invention.
As shown in FIG. 21, the position changing mechanism 70 according to the third embodiment includes an interference member 76, a support shaft 77 that supports the interference member 76, and a bearing 78 provided on one end side of the support shaft 77. It has a gear member 79 provided on the outer periphery of the bearing 78.

The interference member 76 is composed of a flat plate-shaped member that is continuously arranged in the axial direction of the photoconductor 2. The support shaft 77 is fixed to the end of the interference member 76 on the photoconductor 2 side, and is rotatably provided with respect to the support frame 22 that supports the photoconductor 2. By rotating the support shaft 77, the interference member 76 can rotate around the support shaft 77 in the direction of arrow G1 and the direction of arrow G2 in the figure.

The bearing 78 is composed of a one-way clutch as a one-way rotary drive transmission means. It is also possible to use an electromagnetic clutch instead of the one-way clutch. However, from the viewpoint of space saving, simplification of the clutch mounting structure, and improvement of design freedom, it is preferable to use the one-way clutch as in the present embodiment.

As described above, in the present embodiment, since the gear member 79 is connected to the interference member 76 via the one-way clutch (bearing 78), the rotational driving force when the interference member 76 rotates is one-way rotation. Only the driving force is transmitted to the gear member 79. Specifically, in FIG. 21, the one-way clutch applies only the rotational driving force when the interfering member 76 rotates in the direction of arrow G2 in the drawing (rotational driving force when the support shaft 77 rotates in the direction of arrow H2). It is transmitted to the gear member 79, and the rotational driving force when the interfering member 76 rotates in the direction of arrow G1 in the drawing (rotational driving force when the support shaft 77 rotates in the direction of arrow H1) is not transmitted to the gear member 79. It is configured as follows. Further, the gear member 79 is engaged with the photoconductor gear 23 provided on the photoconductor 2. Therefore, when the gear member 79 rotates, the photoconductor 2 rotates integrally with the photoconductor gear 23.

Subsequently, the operation of the position changing mechanism according to the third embodiment will be described.
As shown in FIG. 22, in a state where the cleaning unit 200A is attached to the support frame body 22, the interference member 76 is arranged at a position rotated upward in the drawing. Even if the image-drawing operation is started in this state and the photoconductor 2 rotates, the rotational driving force of the photoconductor 2 at this time is not transmitted to the interference member 76. Therefore, the interference member 76 is held in a predetermined position.

When the cleaning unit 200A is removed from the state shown in FIG. 22 as shown in FIG. 23, the interference member 76 rotates downward (in the direction of arrow G1 in the figure) due to its own weight. Further, the support shaft 77 also rotates in the same direction (direction of arrow H1 in the drawing) at the same time as the rotation of the interference member 76, but the rotational driving force of the support shaft 77 at this time is not transmitted to the gear member 79. Therefore, the photoconductor 2 does not rotate. In this way, the reason why the photoconductor is not rotated when the cleaning unit is removed is that, as in the above embodiment, the rotation of the photoconductor prevents the deposits from adhering to the charging roller and later. This is to obtain the effect of the reverse rotation of the photoconductor.

After that, when installing a new cleaning unit, as shown in FIG. 24, the operator or the user manually rotates the interference member 76 upward (in the direction of arrow G2 in the drawing). By rotating the interference member 76 upward in this way, the interference member 76 can be moved to a retracted position that does not interfere with the attachment of the cleaning unit (allows attachment).

Further, when the interference member 76 is rotated upward, the rotational driving force of the support shaft 77 rotating in the same direction (direction of arrow H2 in the drawing) is transmitted to the gear member 79, so that the gear member 79 is shown in the drawing. Rotate counterclockwise in. As a result, the photoconductor gear 23 rotates clockwise in the figure, and the photoconductor 2 rotates in the direction opposite to the rotation direction at the time of image formation.

Then, as shown in FIG. 25, the new cleaning unit 200B can be attached by arranging the interference member 76 in the retracted position.

As described above, also in the third embodiment, the position of the deposit on the photoconductor can be shifted by rotating the photoconductor in the direction opposite to the rotation direction at the time of image formation, and the cleaning blade or the leveling blade is used. It is possible to prevent pinching of deposits.

Further, in the third embodiment, when the cleaning unit is removed, the interference member rotates downward and is arranged at an interference position (position shown in FIG. 23) that hinders the installation of the cleaning unit, so that a new cleaning unit is used. When mounting the cleaning unit, it is necessary to rotate the interference member upward to move it to the retracted position (position shown in FIG. 25) in order to make the cleaning unit mountable. Then, the photoconductor 2 is rotated in the reverse direction in conjunction with the rotation operation to the retracted position. As described above, according to the configuration of the third embodiment, the interference member is always rotated upward and the photoconductor is reverse-rotated before the cleaning unit is attached. Therefore, the reverse-rotating operation is forgotten. A new cleaning unit will not be installed in the open state.

Further, also in the third embodiment, since the amount of reverse rotation of the photoconductor can be adjusted to a constant amount, there is no variation in the amount of reverse rotation, and it is possible to surely prevent pinching of deposits. In the configuration according to the third embodiment, by reducing the number of teeth of the gear member to be smaller than the number of teeth of the photoconductor gear, the force required to rotate the photoconductor in the reverse direction can be reduced, so that interference occurs. It is possible to improve the operability of the member. Further, here as well, it is desirable that the amount of rotation when the photoconductor is rotated in the reverse direction is set to the same amount of rotation as described with reference to FIG.

FIG. 26 is a schematic configuration diagram of a position changing mechanism according to a fourth embodiment of the present invention.
In the fourth embodiment shown in FIG. 26, only the configuration of the interference member 76 is different from that of the third embodiment shown in FIGS. 21 to 25. Other than that, it has the same configuration. Specifically, the interference member 76 in the fourth embodiment has a shape having a portion 76b extending from the tip end portion of the flat plate-shaped portion 76a similar to the interference member 76 in the third embodiment so as to be bent at a predetermined angle. It is configured. As described above, the interference member 76 in the fourth embodiment is formed to have a size larger than that in the interference member 76 in the third embodiment.

By the way, in the configuration in which the cleaning unit is attached and detached, it is necessary to form an opening in the support frame for attaching and detaching the cleaning unit. This opening is shielded by the cleaning unit when the cleaning unit is attached. However, when the cleaning unit is removed, the opening is opened, so that the photoconductor is easily exposed to the light incident from the opening. If the photoconductor is exposed to light for a long period of time, the photoconductor deteriorates and affects the image quality. Therefore, when the cleaning unit is removed, it is preferable to provide a light-shielding means for blocking the irradiation of light from the opening to the photoconductor.

Therefore, in the fourth embodiment, the interference member is formed large as described above so that the interference member can block light from the photoconductor instead of the cleaning unit. That is, as shown in FIG. 28, when the cleaning unit 200A is removed from the state in which the cleaning unit is attached shown in FIG. 27, the interference member 76 rotates downward due to its own weight to attach and detach the cleaning unit. The opening 22b for performing the above is shielded. As a result, the light L from the outside is blocked by the interference member 76, so that the photoconductor 2 can be prevented from being exposed to the light.

Further, in this state, the tip portion 76c of the interference member 76 is in contact with the edge of the opening 22b so as not to form a gap, so that the tip portion 76c of the interference member 76 and the edge of the opening 22b are in contact with each other. Light is not incident from the light, and the light can be reliably blocked. Further, in the present embodiment, the entire range shielded by the cleaning unit is shielded by the interference member 76.

As described above, according to the configuration according to the fourth embodiment, even when the cleaning unit is removed, the photoconductor can be reliably shielded from light, and deterioration of the photoconductor can be highly prevented. In the fourth embodiment, the operation of rotating the photoconductor in the reverse direction is the same as the operation in the third embodiment, and thus the description thereof will be omitted.

29 and 30 are diagrams showing the configuration and operation of the position changing mechanism according to the fifth embodiment of the present invention.
In the fifth embodiment, the arrangement of the cleaning unit 200A is different from that of the above embodiment. Further, in the fifth embodiment, as shown in FIG. 29, the position where the interference member 76 is rotated downward is the retracted position where the cleaning unit is allowed to be attached, and as shown in FIG. 30, the interference member 76 is The position rotated upward is the interference position that hinders the installation of the cleaning unit. That is, the interference position and the retracted position are upside down from the above embodiment. In such a configuration, the interference member cannot be rotated from the retracted position to the interference position by its own weight as in the above embodiment.

Therefore, in the fifth embodiment, the interference member 76 is urged in order to rotate the interference member 76 from the lower retracted position (position shown in FIG. 29) to the upper interference position (position shown in FIG. 30). A coil spring 80 is provided as an interference member urging means. As a result, as shown in FIG. 30, when the cleaning unit 200A is removed, the interference member 76 is pulled upward by the coil spring 80 and rotates to the interference position.

By providing the interference member urging means in this way, the interference member can be reliably rotated to the interference position without using its own weight, so that the degree of freedom in the configuration of the interference member and the arrangement of the cleaning unit is improved. To do. In the fifth embodiment, the configuration other than the configuration described above is basically the same as the configuration of the third embodiment, and the operation of rotating the photoconductor in the reverse direction is also the same as the operation of the third embodiment. The explanation is omitted.

Although each embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the gist of the present invention. In the above-described embodiment, as an example of a removable unit that can be attached to and detached from the support frame, a cleaning unit that integrally includes a cleaning device and a lubricant supply device is given as an example. However, the present invention describes the cleaning device. It can also be applied to a cleaning unit that can be attached and detached by itself, and an image forming apparatus that includes a lubricant supply unit that can be attached and detached by itself.

Further, the present invention is not limited to the case where the charging roller or the developing roller is in contact with the photoconductor, but also in the configuration in which the charging roller or the developing roller is arranged close to (non-contacting) the photoconductor. It may be applied.

Further, in the above-described embodiment, the lubricant supply device is arranged downstream of the cleaning device in the rotation direction of the photoconductor, but conversely, the cleaning device is located in the rotation direction of the photoconductor rather than the lubricant supply device. The present invention can also be applied to a configuration arranged on the downstream side.

Further, the present invention can be applied to a configuration including a cleaning device for cleaning the intermediate transfer belt as an image carrier for supporting a toner image and a lubricant supply device for supplying a lubricant. In this case, the cleaning device and the lubricant supply device are attached by rotating the drive roller that rotationally drives the intermediate transfer belt in the direction opposite to the rotation direction at the time of image formation by using the position change mechanism according to the present invention. It is possible to prevent the deposit from being pinched by the blade.

Further, the image forming apparatus to which the present invention is applied includes, in addition to a printer, a copying machine, a facsimile alone, or a multifunction device having at least two functions of a copying machine, a printer, a facsimile, and a scanner.

1 Image drawing unit 2 Photoreceptor (image carrier)
5 Cleaning device 6 Lubricant supply device 23 Photoreceptor gear (image carrier gear)
26 One-way clutch (one-way rotary driving force transmission means)
50 Cleaning blade (contact member)
62 Leveling blade (contact member)
70 Position change mechanism 71 Moving member 72 Engaging part 76 Interfering member 78 Bearing (one-way clutch, one-way rotary driving force transmitting means)
79 Gear member 200 Cleaning unit (detachable unit)

Japanese Unexamined Patent Publication No. 2011-97076

Claims (2)

An image carrier that carries an image on the surface and
An image forming apparatus including a contact member that comes into contact with the surface of the image carrier, and a detachable unit that is attached to and detachable from a support frame that supports the image carrier.
From the state before the detachable unit is attached to the attached state , the image carrier is rotated in the direction opposite to the rotation direction at the time of image formation in conjunction with the attachment operation of the detachable unit. comprising a position changing mechanism for changing the rotational direction position Te,
The position changing mechanism includes a moving member that can move between a first position in which the detachable unit is attached and a second position in which the detachable unit is arranged in a detached state. It has an engaging portion that is provided on the moving member and can be engaged with the image carrier gear provided on the image carrier.
When the moving member moves from the second position to the first position in conjunction with the attachment operation of the attachment / detachment unit, the engaging portion engages with the image carrier gear to form the image. By rotating the carrier gear, the image carrier is rotated in the opposite direction.
The engaging portion is configured to be switchable between an upright state capable of engaging with the image carrier gear and a tilted state not engaging with the image carrier gear.
The engaging portion is held in the upright state when the moving member moves from the second position to the first position, and the moving member moves from the first position to the second position. An image forming apparatus characterized in that it can be switched to the collapsed state when moving . An image carrier that carries an image on the surface and
It has a contact member that comes into contact with the surface of the image carrier, and also includes a detachable unit that can be attached to and detached from a support frame that supports the image carrier.
It is an image forming unit configured so that the image carrier and the detachable unit can be integrally attached to and detached from the image forming apparatus main body.
An image forming unit comprising the position changing mechanism according to claim 1.

Images