JP2007183431A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the following problems, wherein if a user erroneously sets a slide member in a second position in such a situation that a positioning unit is released from an image forming apparatus body, each pressurizing member is positioned to pressurize the bearing of the photoreceptor drum, consequently, when setting the positioning unit to the image forming apparatus body, the bearing of each photoreceptor drum interferes with each pressurizing member, then becomes difficult to set the positioning unit in the image forming apparatus body. <P>SOLUTION: A control member 85 that controls the slide member 41A so as not to slide to the second position, when the positioning unit 70 is released from the image forming apparatus body is provided in a positioning holding member 32A. When the positioning unit 70 with respect to the image forming apparatus body is to be closed, a pin 88 is passed through the hole 89 of the positioning unit 70, then is pressurized and the control member 85 is oscillated in the direction shown by an arrow C, the slide member 41A is released from the slide control by the control member to the second position. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a facsimile machine, a printer, a plotter, etc., or a multifunction machine having a plurality of functions, and more particularly to a positioning method of an image carrier unit.

An image forming apparatus of the above type configured as an electrophotographic copying machine, a copying machine, a facsimile machine, a printer, a plotter or the like or a multifunction machine having a plurality of functions has been known.
In this type of image forming apparatus, particularly a multicolor image forming apparatus having a plurality of image carriers, an image forming apparatus provided with an image carrier made of, for example, a drum-shaped photoreceptor (hereinafter referred to as “photoreceptor drum”). When a plurality of image carrier units (process cartridges) configured to be detachable from the main body are mounted on the main body of the image forming apparatus, accurate positioning of images including color misregistration is possible. It has become an important issue in preventing this, and various methods have been proposed and put into practical use (see, for example, Patent Documents 1 to 6).

However, each of the techniques described in Patent Documents 1 to 6 has a problem that the operation method such as attachment and detachment of the positioning member is complicated or difficult, and the operability is inferior and the cost is high. Had.
Accordingly, the applicant of the present application has proposed a technique relating to a novel image forming apparatus and the like that can solve the above-mentioned problems in Japanese Patent Application No. 2005-332015 (patent application on November 16, 2005).

JP-A-4-228989 JP 2004-177443 A Japanese Patent Laid-Open No. 10-7260 JP 2004-233902 A JP 2001-242671 A JP 2001-222207 A

However, in the technology described in Japanese Patent Application No. 2005-332015 (first to third comparative examples described later), it has been found that there is a problem to be improved in putting this into practical use. While explaining.
First, the first problem will be described with reference to FIGS. 8 to 11 showing a second comparative example. 8 to 11, reference numerals 1Y to 1BK have a photosensitive drum as an image carrier, a charging device as a charging means having a charging roller, a developing device as a developing means having a developing roller, a cleaning blade, and the like. A process cartridge comprising a cleaning device or the like as a cleaning means, 7 is a main body of the image forming apparatus, 16 is a support shaft for the photosensitive drum, and 17 is a support shaft for the photosensitive drum 16 that is rotatable. Reference numeral 15 denotes a bearing support member composed of a support shaft 16 and a bearing 17 for supporting the photosensitive drum, and reference numeral 70 denotes a process cartridge 1Y to 1BK via the bearing support member 15. , Openable and closable positioning units for positioning with respect to the image forming apparatus main body 7 are shown respectively.

  When the positioning unit 70 is swung in the direction of arrow D with respect to the image forming apparatus main body 7 and closed, the four opening mounting holes 77 in which the carrier support member 15 is held by the weight of each process cartridge 1Y to 1BK. Positioning and holding member 32A as a single holding member provided with surfaces 78 and 79 as holding parts, and surface 78 of mounting hole 77 provided corresponding to carrier support member 15 of each process cartridge 1Y to 1BK. 10 between the non-pressing position shown in FIG. 10 which is not in contact with the carrier supporting member 15 on 79 and the pressing position shown in FIG. 11 for pressing and positioning the carrier supporting member 15 on the surfaces 78 and 79 of the mounting hole 77. The four pressing members 44A that can be moved at the same time, springs 71 as urging means for urging each pressing member 44A to move to the pressing position, and each pressing member 44A. The positioning holding member 32A is slidably movable between the first position shown in FIG. 10 corresponding to the non-pressing position and the second position shown in FIG. 11 corresponding to the pressing position. It is mainly composed of a single slide member 41A as a supported movable member.

  8 to 11, when the photosensitive drum or the like is replaced, that is, when the process cartridges 1Y to 1BK are replaced, the slide member 41A slidably supported by the positioning holding member 32A is as shown in FIG. In the drawing, the pressing member 44A is moved to the first position by sliding it to the left side, and the pressing unit 44A is moved to the non-pressing position where it is separated from the bearing 17 of each photosensitive drum, and then the positioning unit 70 is illustrated with the hinge pin 34 as the center. 8 is moved to the open position in a state of being released from the image forming apparatus main body 7.

When the replacement of the photosensitive drum and the like is completed, the positioning unit 70 is swung around the hinge pin 34 in the direction of arrow D in FIG. Then, by sliding the slide member 41A to the right as shown in FIG. 11, the pressing member 44A comes into contact with the bearing 17 of each photosensitive drum by setting the slide member 41A to the second position. By occupying the pressing position where this is pressed, the bearing 17 of each photosensitive drum is positioned and held at a predetermined position.
However, with the positioning unit 70 opened from the image forming apparatus main body 7 as shown in FIG. 8, a user, a serviceman, or the like mistakenly slides the slide member 41A to the right in the drawing as shown in FIG. When the second position is set, the pressing members 44A occupy the pressing positions and hold the photosensitive drum bearings 17, so that the positioning unit 70 is attached to the image forming apparatus main body 7. When mounting and setting, the bearings 17 of the respective photosensitive drums and the pressing members 44A interfere with each other, which makes it difficult to set the positioning unit 70 in the image forming apparatus main body 7.

Next, the second problem will be described with reference to FIGS. 8 to 11 and FIGS. 23 to 26 showing a third comparative example. As shown in the direction of arrow D in FIGS. 8 and 24, when the positioning unit 70 is set in the image forming apparatus main body 7, the positioning holes 73a and 73b provided on the left and right sides of the positioning holding member 32A are provided on the positioning unit 73A. Oppositely, they are fitted to positioning pins 74 a and 74 b provided on the left and right sides of the opening 31 in the front side plate 28 of the image forming apparatus main body 7.
The positioning hole 73a and the positioning hole 73b are for distinguishing the left and right formation positions in the figure and have the same shape and dimensions. Similarly, the positioning pin 74a and the positioning pin 74b have the same shape and dimensions. . Hereinafter, the fitting state between the left positioning hole 73b and the positioning pin 74b will be described as a representative in the figure, but the same malfunction occurs even in the fitting state between the right positioning hole 73a and the positioning pin 74a in the figure. .

As shown in FIGS. 24 and 25, the positioning pin 74b has a tapered portion 74c which is formed at the tip portion thereof so as to be guided by the positioning hole 73b fitted therewith, and is tapered toward the tip portion, and a slide member. A groove 74d formed over the entire circumference of the long hole 72b of 41A and loosely fitted (inserted), and a fitting portion 74e into which the positioning hole 73b of the positioning holding member 32A is fitted.
Then, as shown in FIG. 25, when the positioning unit 70 having the positioning holding member 32A, the slide member 41A, etc. is set by swinging in the direction of arrow D in FIG. 24, the positioning hole provided in the positioning holding member 32A. 73b is correctly fitted to the fitting portion 74e of the positioning pin 74a.
However, as shown in FIG. 26, when the positioning unit 70 is slightly lowered due to its own weight or the like, the positioning hole 73b fits into the groove 74d of the positioning pin 74b before reaching the fitting portion 74e of the positioning pin 74a. There is a second problem that it becomes difficult to fit the fitting portion 74e of the positioning pin 74b into the positioning hole 73b. This problem also applies to the positioning pin 74a on the opposite side.

The present invention has been made in view of the above-described circumstances, and includes a positioning and holding member 32A (holding member) that restricts the slide (movement) of the slide member 41A (movable member) to the second position. By providing it to the member), when the positioning unit 70 is in the open state, even if a user or a serviceman mistakenly tries to slide the slide member 41A (movable member) to the right side in the drawing, it becomes impossible to move. A first object of the present invention is to achieve smooth mounting of the positioning unit to the image forming apparatus main body by avoiding interference between the carrier support member of the image carrier unit and a movable member (including a pressing member). To do.
Further, in addition to the first purpose or independently of the first purpose, the positioning unit 70 including the positioning holding member 32A, the slide member 41A and the like is swung in the direction of arrow D in FIG. 24 and set. At this time, before the positioning hole 73b (positioning concave portion) provided in the positioning holding member 32A reaches the fitting portion 74e of the positioning pin 74b (positioning convex portion), the positioning holding member 32A of the positioning unit 70 is caused by its own weight or the like. A second object is to realize a smooth and reliable fitting without getting stuck in the groove 74d of the positioning pin 74b.

In order to solve the above-described problems and achieve the above-described object, the invention for each claim employs the following characteristic means and invention-specific matters (hereinafter referred to as “configuration”).
According to a first aspect of the present invention, there is provided at least one image carrier unit including an image carrier and a carrier support member that supports the image carrier, and the at least one image carrier unit as the carrier support member. And an openable / closable positioning unit for positioning with respect to the image forming apparatus main body, and the positioning unit is held by the carrier support member when the positioning unit is closed with respect to the image forming apparatus main body. A holding member having at least one opened holding portion, a first position not pressing the carrier supporting member on the at least one holding portion, and the carrier supporting member on the at least one holding portion. A movable member that is supported by the holding member so as to be movable between a second position that presses the image, and the image on the at least one image carrier is directly or indirectly displayed on the screen. An image forming apparatus to be transferred to the recording medium, wherein when the positioning unit is opened with respect to the image forming apparatus main body, a restricting means for restricting the movement of the movable member to the second position; The holding member is provided.

  According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, when the positioning unit is closed with respect to the main body of the image forming apparatus, the movement of the movable member to the second position by the restriction unit is restricted. It is characterized by having movement restriction cancellation means for canceling the above.

  According to a third aspect of the present invention, in the image forming apparatus according to the second aspect, the image forming apparatus main body is engageable with the holding member when the positioning unit is closed with respect to the image forming apparatus main body. A convex portion is provided, and the holding member is provided with a concave portion that engages with the convex portion, and when the movable member occupies the first position, the restricting means The engagement position with the movable member is released by engaging the movable member with the restricting position for blocking and engaging the movable member at the first position and the convex portion and the concave portion. The movable member includes a restricting member that is displaceable with respect to a non-restricted position that allows movement of the movable member to the second position, the movement restriction releasing unit includes the convex portion, and the positioning unit is configured to be the image forming apparatus. When closed against the body, By Kitotsu portion is engaged with the recess, characterized in that for displacing the regulating member to said non-restricting position.

  According to a fourth aspect of the present invention, in the image forming apparatus according to the third aspect, the convex portion is a positioning convex portion for positioning the positioning unit with respect to the image forming apparatus main body, and the concave portion is The restricting means includes a positioning recess that fits with the positioning protrusion, and the restricting means blocks the positioning recess and engages the movable member when the movable member occupies the first position. When the restriction position held at the position 1 is engaged with the positioning convex portion and the positioning concave portion, the engagement state with the movable member is released, and the movable member is moved to the second position. The movement restricting means comprises the positioning projection, and the positioning unit is closed when the positioning unit is closed with respect to the image forming apparatus main body. By positioning convex portion is mated with the positioning recess, characterized in that to displace the regulating member to said non-restricting position.

  According to a fifth aspect of the present invention, in the image forming apparatus according to the third or fourth aspect, the regulating member and the movable member are both formed of a metal plate-like member, and surfaces in the thickness direction of each other are formed. Are formed and arranged in such a shape that they come into contact with each other.

  A sixth aspect of the present invention is the image forming apparatus according to any one of the third to fifth aspects, further comprising a regulating member biasing unit that biases the regulating member in a direction occupying the regulated position. It is characterized by.

  According to a seventh aspect of the present invention, in the image forming apparatus according to the sixth aspect, the urging force by the regulating member urging means is set in a direction orthogonal to the moving direction of the movable member. And

  According to an eighth aspect of the present invention, at least one image carrier unit including an image carrier and a carrier support member that supports the image carrier, and the at least one image carrier unit is used as the carrier support member. And an openable / closable positioning unit for positioning with respect to the image forming apparatus main body, and the positioning unit is held by the carrier support member when the positioning unit is closed with respect to the image forming apparatus main body. A holding member having at least one opened holding portion, a first position not pressing the carrier supporting member on the at least one holding portion, and the carrier supporting member on the at least one holding portion. A movable member that is supported by the holding member so as to be movable between a second position that presses the image, and the image on the at least one image carrier is directly or indirectly displayed on the screen. An image forming apparatus to be transferred to a sheet recording medium, wherein the positioning unit is attached to the image forming apparatus main body when the positioning unit is closed with respect to the image forming apparatus main body. A positioning projection for positioning is provided, and the holding member is provided with a positioning recess for fitting with the positioning projection when the positioning unit is closed with respect to the image forming apparatus main body. The positioning convex portion is formed at a tip portion thereof to be guided to the positioning concave portion, and is tapered toward the tip portion, and from a terminal end of the taper portion to a portion where the positioning concave portion is fitted. Formed between the continuous surface portion having substantially the same outer diameter and a portion of the continuous surface portion so as not to obstruct the entire outer periphery of the continuous surface portion. Characterized in that it comprises a made a groove.

  According to a ninth aspect of the present invention, in the image forming apparatus according to the eighth aspect, the groove portion includes at least one flat portion substantially parallel to a moving direction of the movable member.

  According to a tenth aspect of the present invention, in the image forming apparatus according to the ninth aspect, the at least one flat portion has two planar shapes parallel to each other.

According to the present invention, a novel image forming apparatus can be provided by solving the above-described problems. The effects of each main claim are as follows.
According to the present invention, when the positioning unit is opened with respect to the image forming apparatus main body, the movement of the movable member to the second position is restricted by the restricting means, so that the movable member is the first member. For example, a user or a serviceman can prevent the movable member from being accidentally moved to the second position, and thus the carrier can be closed when the positioning unit is closed with respect to the image forming apparatus main body. Interference between the support member and the movable member (including a pressing member, for example) can be avoided, so that the positioning unit can be smoothly attached to the image forming apparatus main body (claim 1).

  According to the present invention, when the positioning unit is closed with respect to the main body of the image forming apparatus, the movement restriction releasing means reliably releases the movement restriction of the movable member to the second position by the restriction means. The effects of the described invention are more reliably achieved (claims 2 and 3).

  According to the present invention, when the movable member occupies the first position, the restricting means blocks the positioning recess and engages the movable member to hold the movable member at the first position. When the positioning convex portion and the positioning concave portion are fitted to each other, the engagement state with the movable member is released and the movable member is allowed to move to the second position. The movement restriction releasing means is composed of a positioning convex portion, and when the positioning unit is closed with respect to the image forming apparatus main body, the positioning convex portion is engaged with the positioning concave portion to displace the regulating member to the non-regulating position. Therefore, since the positioning convex portion also serves as the movement restriction releasing means, no special movement restriction releasing means is required, and the cost can be saved.

  According to the present invention, the restricting member and the movable member are both formed of metal plate-like members, and are formed and arranged in such a shape that the surfaces in the plate thickness direction are in contact with each other, so that they are strong. Even if the movable member is moved by force, the restriction member and the movable member can be prevented from being damaged.

  According to the present invention, since the regulating member is always urged in the direction in which the regulating member occupies the regulating position by the regulating member urging unit, the holding and fixing of the movable member to the first position by the regulating unit is more reliable. (Claim 6).

  According to the present invention, since the urging force by the urging means for the restricting member is set in a direction orthogonal to the moving direction of the movable member, for example, when the urging force is set along the moving direction of the movable member The effect of the invention of claim 5 can be achieved by a smaller urging force than the above (claim 7).

  According to the present invention, the positioning convex portion provided in the image forming apparatus main body is formed at the leading end portion thereof so as to be guided by the positioning concave portion and is tapered toward the leading end, and the terminal end of the tapered portion. Is formed between the positioning concave portion provided on the holding member and the portion where it is fitted, and a continuous surface portion having substantially the same outer diameter and a part of the continuous surface portion so as not to block the entire outer periphery of the continuous surface portion. When the positioning unit is closed with respect to the main body of the image forming apparatus, the positioning concave portion and the continuous surface portion of the positioning convex portion are fitted while the positioning concave portion is guided by the continuous surface portion of the positioning convex portion. Therefore, the holding member does not get stuck in the groove before reaching the part where the positioning convex part fits due to its own weight, etc. Can be engaged (claim 8).

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments including the best mode and examples for carrying out the present invention will be described below with reference to the drawings. In each comparative example, embodiment, modification, etc., which will be described later, constituent elements such as members and components having the same function are given the same reference numerals as much as possible, and once described, the description will be given. Omitted as much as possible. In order to simplify the drawings and the description, even components that are to be represented in the drawings may be omitted as appropriate without being specifically described in the drawings.

FIG. 1 shows an example of an image forming apparatus to which the present invention is applied. First, the overall configuration and operation of the image forming apparatus will be described with reference to FIG.
The image forming apparatus shown in the figure has a tandem image forming apparatus configuration for forming a full-color image. This image forming apparatus includes first to fourth process cartridges 1Y, 1C, 1M, and 1BK that are mounted and arranged in the image forming apparatus main body 7, and an intermediate transfer member that is arranged to face these process cartridges. Intermediate transfer belt 2. The intermediate transfer belt 2 is an endless belt and is wound around a plurality of rollers 3, 4, 5 having a driving roller and a driven roller. Each of the process cartridges 1Y to 1BK has a drum-like photoconductor (hereinafter referred to as “photosensitive drum”) 6Y, 6C, 6M, 6BK as an image carrier, and different colors are provided on the photoconductor drums. The toner images are formed, and the toner images are sequentially transferred to the intermediate transfer belt 2.
Each of the process cartridges 1Y to 1BK is configured to be detachable from the image forming apparatus main body 7 in the longitudinal direction of the rotation shaft (not shown) of each photosensitive drum 6Y to 6BK that can be regarded as an opening / closing direction of a positioning unit described later. ing.

  The configuration of the first to fourth process cartridges 1Y to 1BK and the configuration of transferring the toner images formed on the photosensitive drums 6Y to 6BK to the intermediate transfer belt 2 are different only in the colors of the toner images. Since all of them are substantially the same, the configuration of the first process cartridge 1Y and the configuration of transferring the toner image on the photosensitive drum 6Y to the intermediate transfer belt 2 will be described as a representative, and the description of the rest will be omitted. To do. Further, in each of the drawings after FIG. 2, the same constituent parts are simplified by adding European characters representing colors only to the process cartridge, the photosensitive drum, and the cartridge case, and to other constituent parts. Will be omitted.

The first process cartridge 1Y includes a charging device 11Y as a charging unit having a charging roller 8Y and the like disposed around the photosensitive drum 6Y, a developing device 9Y as a developing unit having a developing roller 12Y and the like, and a cleaning blade. And a cleaning device 10Y as a cleaning means having 13Y or the like. Each case of these devices 11Y, 9Y, 10Y is constituted by a cartridge case 14Y which is a common unit case.
FIG. 2 is a partial cross-sectional view showing the photosensitive drum 6Y of the process cartridge 1Y and the carrier support member 15 that supports the photosensitive drum 6Y. In this figure, other components of the process cartridge 1Y are shown. It is omitted. As shown in FIG. 3, the carrier support member 15 shown here includes a support shaft 16 that is a rotating shaft, and a bearing 17 that is, for example, a ball bearing attached to the support shaft 16. The drum 6Y is fixedly supported on the support shaft 16 via flanges 18 and 19 fixed to both ends thereof. The support shaft 16 is rotatably assembled to the cartridge case 14Y shown in FIG. 1 via a bearing (not shown).

  When the image forming operation is started, the photosensitive drum 6Y is rotationally driven in the clockwise direction in FIG. 1, and the intermediate transfer belt 2 is rotationally driven in the arrow A direction. At this time, the charging roller 8Y of the charging device 11Y rotates while contacting the surface of the photosensitive drum 6Y, and the photosensitive drum 6Y is charged to a predetermined polarity by the action of the charging roller 8Y. The charged photoconductor drum 6Y is irradiated with light-modulated laser light L emitted from the exposure apparatus 20 shown in FIG. 1 which is separate from the process cartridge 1Y. An image is formed.

  The developing roller 12Y of the developing device 9Y is rotationally driven counterclockwise in FIG. 1, and a dry developer is carried and conveyed on the developing roller 12Y, and yellow toner in the developer is formed on the photosensitive drum 6Y. The electrostatic latent image is electrostatically transferred and adhered to the electrostatic latent image, and the electrostatic latent image is visualized as a yellow toner image. A primary transfer roller 21Y as a primary transfer unit is disposed on the opposite side of the process cartridge 1Y across the intermediate transfer belt 2, and is formed on the photosensitive drum 6Y by the action of the primary transfer roller 21Y. The toner image is transferred onto the intermediate transfer belt 2. The transfer residual toner adhering to the photosensitive drum 6Y after the toner image transfer is scraped and removed from the surface of the photosensitive drum 6Y by the cleaning blade 13Y of the cleaning device 10Y.

  In exactly the same manner as described above, a cyan toner image, a magenta toner image, and a black toner image on the photosensitive drums 6C, 6M, and 6BK of the second to fourth process cartridges 1C, 1M, and 1BK shown in FIG. Are formed, and these toner images are sequentially transferred onto the intermediate transfer belt 2 on which the yellow toner image is transferred.

  On the other hand, as shown in FIG. 1, a sheet feeding cassette 22 containing a transfer sheet P as an example of a sheet-like recording medium is disposed in the lower part of the image forming apparatus main body 7. The paper is fed in the direction of arrow B by the rotation of the paper feed roller 23. The transferred transfer paper P is fed between the intermediate transfer belt 2 and a secondary transfer roller 24 as a secondary transfer unit disposed opposite to the intermediate transfer belt 2. At this time, due to the action of the secondary transfer roller 24, The toner image on the intermediate transfer belt 2 is transferred to the transfer paper P. The recording medium to which the toner image has been transferred is further conveyed upward and passes through the fixing unit 25. At this time, the toner image on the recording medium is fixed by the action of heat and pressure. The recording medium that has passed through the fixing unit 25 is discharged onto a paper discharge unit 26 at the top of the image forming apparatus main body 7. Further, the transfer residual toner adhering to the intermediate transfer belt 2 after the toner image is transferred is removed by the cleaning unit 27 for the intermediate transfer belt 2.

(First comparative example)
Next, the positioning configuration and operation when the process cartridges 1Y to 1BK are mounted on the image forming apparatus main body 7 will be described. As will be described later, the embodiment of the present invention will be described with reference to the positioning configuration shown in FIGS. The positioning configuration shown in FIGS. 8 to 18 (hereinafter referred to as “second comparative example”) and the positioning configuration shown in FIGS. 23 to 27 (hereinafter referred to as “third comparative example”). Therefore, the details will be described in detail.
2 indicates the front side of the image forming apparatus, and R indicates the back side, that is, the rear side of the image forming apparatus. As will be described later, the process cartridge 1Y and the other process cartridges 1C, 1M, and 1BK are attached to the image forming apparatus main body 7 so as to be detachable in the front-rear direction, in other words, in the longitudinal direction of the support shaft 16. The frame 33 constituting the image forming apparatus main body 7 includes a front side plate 28 arranged on the near side, a rear side plate 29 arranged on the back side, and these side plates 28 and 29 as shown in FIG. It has a fixed bottom plate 30 (FIG. 3).

The opening 31 formed in the front plate 28 on the image forming apparatus main body 7 side normally attaches and detaches the process cartridges 1Y to 1BK via the carrier support members 15 as shown in FIGS. It is covered with an openable and closable positioning unit 65 for positioning. As shown in FIG. 2 to FIG. 7, the positioning unit 65 is a holding portion formed in the opening attachment hole 37 in which each carrier support member 15 is held when the positioning unit 65 is closed with respect to the opening 31 of the front side plate 28. The single positioning and holding member 32 having the two surfaces 45 and 46, and pressing means to be described later for pressing and positioning the carrier support members 15 held on the two surfaces 45 and 46 are mainly configured. ing.
Around the frame 33 and the positioning and holding member 32, an exterior cover (not shown) and a front cover (not shown) supported by the exterior cover are positioned.

  As shown in FIGS. 2 and 3, the positioning holding member 32 can be rotated within a range of a predetermined angle in a direction indicated by arrows C and D to the front side plate 28 via a pair of hinge pins 34, that is, swinging and opening / closing. It is freely pivoted and normally occupies the closed position shown in FIG. When the positioning and holding member 32 occupies the closed position, the positioning hole 35a formed in the positioning and holding member 32 is fitted into the positioning pin 36a projecting from the front side plate 28, and other positioning and holding members 32 are formed. The positioning hole 35b is fitted into a positioning pin 36b projecting from the front side plate 28, and the positioning holding member 32 is positioned with respect to the frame 33 of the image forming apparatus main body. The position of the positioning holding member 32 at this time is a predetermined mounting position positioned with respect to the frame 33. As described above, the positioning holding member 32 is positioned at a predetermined mounting position with respect to the frame 33 of the image forming apparatus main body 7 and is attached to be freely opened and closed.

  As shown in FIG. 3, the positioning holding member 32 is provided with mounting holes 37 corresponding to the respective carrier support members 15, and the positioning holding member 32 is in the closed position shown in FIG. In some cases, a portion on the front side of each carrier support member 15, in this example, each bearing 17 is fitted and held in each mounting hole 37, and a portion on the front side of each carrier support member 15 as will be described later. Is positioned with respect to the positioning holding member 32. As described above, the positioning and holding member 32 is formed with the mounting hole 37 into which each carrier support member 15 is fitted and held in a state where the positioning and holding member 32 is attached to the mounting position.

  On the other hand, as shown in FIG. 2, a carrier gear 38 is fixed to the back end of the support shaft 16 that supports the photosensitive drum 6Y of the process cartridge 1Y. A shaft 40 of a cup gear 39 that can be attached to and detached from the carrier gear 38 is rotatably supported on the rear plate 29, and the carrier gear 38 is engaged with the cup gear 39 in the state shown in FIG. Thereby, the end of the back side of the support shaft 16 is positioned with respect to the longitudinal direction of the support shaft 16 with respect to the rear plate 29. Non-rotating pins (not shown) project from the front side and the back side of the cartridge case 14Y, and these pins fit into holes (not shown) formed in the positioning holding member 32 and the rear plate 29. This prevents the process cartridge 1Y from turning around the support shaft 16.

The shaft 40 is rotationally driven by a motor (not shown), and the rotation is transmitted to the support shaft 16 via gears 39 and 38, whereby the photosensitive drum 6Y is rotationally driven as described above. At this time, the portion on the near side of the support shaft 16 is held in the mounting hole 37 of the positioning holding member 32 via the bearing 17, so that the support shaft 16 can rotate without any trouble.
The rear ends of the support shafts 16 of the other process cartridges 1C, 1M, and 1BK are also positioned on the rear plate 29 in the same manner as described above, and the support shafts 16 and the photosensitive drums 6C and 6M are positioned. , 6BK are rotated in the same manner as described above.

  When the front door (not shown) is opened while the operation of the motor is stopped, and the positioning holding member 32 is rotated to the open position shown in FIG. 3, the opening 31 is opened. In this state, when the process cartridge 1Y is pulled in the forward direction indicated by the arrow E, the process cartridge 1Y is pulled out in the forward direction while being guided by a guide rail that constitutes attachment / detachment means (not shown). On the contrary, when each process cartridge 1Y is pushed in the back direction indicated by the arrow G, the process cartridge 1Y is pushed in the back direction while being guided by the guide rail, and the carrier gear 38 is moved to the cup as shown in FIG. The rear end of the support shaft 16 is positioned with respect to the frame 33 by engaging with the gear 39. Next, the positioning holding member 32 is swung to the closed position shown in FIG. In this state, as will be described later, the front portion of the support shaft 16 can be positioned with respect to the frame 33. Then, the image forming operation can be started by closing the front door. Other process cartridges 1C, 1M, and 1BK can be attached to and detached from the image forming apparatus main body 7 in the same manner.

Next, a specific configuration for positioning the front portion of each carrier support member 15 with respect to the frame 33 of the image forming apparatus main body 7 will be described.
4, as described above, the process cartridges 1Y to 1BK are pushed into the back side of the main body of the image forming apparatus, the positioning holding member 32 is turned to the closed position, and the positioning holes 35a formed in the positioning holding member 32, FIG. 5 is a view showing a state in which a positioning holding member 32 is positioned at a predetermined mounting position by fitting 35b to positioning pins 36a and 36b projecting from the front side plate 28, in the direction of arrow IV in FIG. FIG. As can be seen from FIGS. 4, 2, and 6, a slide member 41 is disposed on the positioning holding member 32.
The slide member 41 is formed with a plurality of long holes 42 that are long in the horizontal direction, and stepped screws 43 are inserted into the respective long holes 42 so as to be relatively slidable. 32 is screwed. Thereby, the slide member 41 is supported by the positioning holding member 32 so as to be slidable and movable in the horizontal direction between the first position shown in FIG. 4 and the second position shown in FIG.

  When the positioning and holding member 32 is swung from the open position shown in FIG. 3 to the closed position shown in FIG. 4, each bearing 17 is inserted into each mounting hole 37 formed in the positioning and holding member 32. As can be seen from FIG. 4, the size of each mounting hole 37 is set larger than the cross-sectional area of each support shaft 16 and each bearing 17 fitted thereto, and each bearing 17 is larger than each mounting hole 37. Insert with play. For this reason, each bearing 17 can be easily fitted in each mounting hole 37. As shown in FIG. 4, each mounting hole 37 is partitioned by two surfaces, a vertical surface 45 and a horizontal surface 46 as a holding portion for holding the bearing 17, and another curved surface 47. The smooth surface 45 and the horizontal surface 46 are substantially orthogonal to each other.

On the other hand, as shown in FIGS. 2, 4, 5, and 6, each pressing member 44 is provided corresponding to each bearing 17, and each pressing member 44, as shown in FIG. 7, It has the wedge-shaped part 53 which makes the wedge shape formed in the taper shape. Furthermore, each pressing member 44 is formed with a long hole 48 extending substantially horizontally, and a stopper 49 made of a stepped screw screwed to the slide member 41 slides relative to each long hole 48. It is possible to fit. Accordingly, each pressing member 44 can slide and move in a horizontal direction with respect to the slide member 41 by a predetermined stroke.
Further, the lower surface of the upper flange portion of the slide member 41 functions as a guide surface 50 that guides the pressing member 44 when each pressing member 44 moves in the horizontal direction. As described above, the guide surface 50 for each pressing member 44 is formed on the slide member 41.

As shown in FIG. 4, each end of a tension spring 52 as an urging means is locked to each pressing member 44 and each anchoring pin 51 protruding from the slide member 41. As a result, each pressing member 44 is urged to the right in FIG. 4, but when the slide member 41 occupies the first position shown in FIG. The end portions 61 are in contact with the stoppers 49, and the pressing members 44 are stopped at the positions shown in FIG. At this time, each pressing member 44 does not contact each bearing 17 of each carrier support member 15.
Thus, each pressing member 44 is movably supported by the slide member 41 in a state of being biased by the spring 52, and when the slide member 41 is in the first position, the pressing member 44 biased by the spring. This is regulated by a stopper 49 provided on the slide member 41 and is prohibited from contacting the carrier support member 15. Therefore, when the operator manually moves the positioning and holding member 32 from the open position shown in FIG. 2 to the closed position shown in FIG. 4, each bearing 17 interferes with each pressing member 44. And can be fitted into each mounting hole 37.

  Next, when the operator slides the slide member 41 shown in FIG. 4 to the right by manual operation to occupy the second position shown in FIG. 5, the wedge-shaped portion 53 of each pressing member 44 is guided. It is press-fitted between the surface 50 and each bearing 17 of each carrier support member 15, and presses each bearing 17 against the two surfaces 45 and 46 that define each mounting hole 37. The operation at this time will be described in more detail below.

When the slide member 41 starts to move from the first position shown in FIG. 4 toward the second position shown in FIG. 5, the pressures urged by the springs 52 and restricted by the stoppers 49. The member 44 starts to move to the right in FIG. 4 together with the slide member 41. Next, when the slide member 41 reaches a predetermined position between the first position and the second position, the wedge-shaped portion 53 of each pressing member 44 urged by each spring 52 has the guide surface 50 and each carrier. It is press-fitted between the bearings 17 of the support member 15, presses against the outer peripheral surface of each bearing 17 and stops. Accordingly, each pressing member 44 strongly presses each bearing 17 against the two surfaces 45 and 46 of each mounting hole 37.
Even after each pressing member 44 is stopped, when the slide member 41 is moved toward the second position against the urging force of each spring 52, each end portion of the long hole 48 formed in each pressing member 44. 61 separates from each stopper 49 and each pressing member 44 is released from the restriction by each stopper 49.

  As described above, the bearings 17 are pressed against the two surfaces 45 and 46 of the mounting holes 37 by the pressing force of the wedge-shaped portions 53 of the pressing members 44 urged by the springs 52. The member 15 and the front side portions of the photosensitive drums 6Y to 6BK supported by the member 15 are correctly positioned with respect to the positioning holding member 32. At this time, since the positioning and holding member 32 is correctly positioned with respect to the frame 33, the respective photosensitive drums 6Y to 6BK are correctly positioned with respect to the frame 33 of the image forming apparatus main body 7. The operator can position the photosensitive drums 6Y to 6BK with respect to the image forming apparatus main body 7 simply by attaching the positioning holding member 32 to the frame 33 at a predetermined position and moving the slide member 41. It is. In addition, since the size of the mounting hole 37 formed in the positioning holding member 32 can be set to be much larger than the cross-sectional area of the front end of the carrier support member 15, each carrier support member 15 can be easily attached to each attachment hole 37. It can be inserted into.

As a matter of course, the dimensional accuracy of the positioning and holding member 32 with respect to the frame 33, the pitch of the two surfaces 45 and 46 of each mounting hole 37 of the positioning and holding member 32, and the dimensional accuracy of each part are determined by the respective photosensitive drums 6Y to 6BK. Needless to say, it is set within a predetermined accuracy range (tolerance) for positioning with respect to the image forming apparatus main body 7.
As described above, the pressing means is provided corresponding to each carrier support member 15 and is not in contact with each carrier support member 15 on each holder, and each holding portion (two surfaces 45, 46). ) A plurality of pressing members 44 that can be moved between pressing positions for pressing and positioning the respective carrier support members 15, and biasing means for biasing each pressing member 44 in the direction of moving to the pressing position. The tension spring 52 and each pressing member 44 are movably supported and supported by the positioning holding member 32 so as to be movable between a first position corresponding to the non-pressing position and a second position corresponding to the pressing position. It is mainly comprised from the single slide member 41 made, and the moving means (not shown) which moves the slide member 41 between the 1st position and the 2nd position.

  Here, for example, the problems are arranged in comparison with the positioning method of the image carrier unit described in JP-A-2001-222207 (Patent Document 6). In the paragraph “0067” of the publication, “... (omitted)... Shaft 12 a of the photosensitive drum 12 of the process cartridge 10 is coupled to the coupling 95 of the drive unit 90 and the bearing portion 201 of the CRG receiver 200 of the opening / closing lid unit 500. And the hole 111 of the working plate 110 and the auxiliary members 115 and 116 are positioned and accurately held by the color image forming apparatus. As described above, according to the technique described in the publication, the dimensional accuracy of the positioning portion of the bearing portion 201 of the CRG receiver 200 that performs the lateral positioning is ensured, so that the shafts 12a of the respective photosensitive drums 12 can be fitted. Even if the frictional resistance increases and the vertical positioning is performed by gradually shifting the contact timing of the auxiliary members 115 and 116 with respect to the shaft 12a of each photosensitive drum 12, the conventional example of the present invention described above ( First comparative example) There is a problem that the ease of operability is not expected. Further, there is a risk of wear due to rubbing of the positioning / fitting portion.

  As described above, the image forming apparatus shown in FIGS. 1 to 7 is loosely fitted into each mounting hole 37, that is, the carrier support member 15 fitted therein is divided into two surfaces 45 that define each mounting hole 37. The pressing member 44 has a wedge-shaped portion 53 that is press-fitted between the guide surface 50 and the carrier support member 15 and presses the carrier support member 15. ing. In addition, when the slide member 41 is in the first position, the pressing member 44 biased by the spring 52 is regulated by the stopper 49 provided on the slide member 41 and may contact the carrier support member 15. When the slide member 41 is prohibited and moved from the first position toward the second position, the pressing member 44 biased by the spring and restricted by the stopper 49 moves together with the slide member 41, and the slide member When 41 reaches the position between the first position and the second position, the pressing member 44 biased by the spring 52 has a wedge-shaped portion 53 between the guide surface 50 and the carrier support member 15. The slide member 41 and the pressing portion so that the pressing member 44 is released from the restriction by the stopper 49 when the slide member 41 further moves toward the second position. And 44, a spring 52, is the position of the stopper 49 is set.

  When the slide member 41 is made to occupy the second position shown in FIG. 5, the wedge-shaped portion 53 of each pressing member 44 is press-fitted between the guide surface 50 and the outer peripheral surface of each bearing 17. Each carrier support member 15 is held in a normal position by the frictional force and the urging force of the spring 52, so that the respective photosensitive drums 6Y to 6BK can be kept correctly positioned. Further, if the slide member 41 is returned to the first position shown in FIG. 4 again by manual operation, each pressing member 44 is separated from the outer peripheral surface of each bearing 17, so that the positioning and holding member 32 is not hindered. Can be swung to the open position shown in FIG.

Further, since the two surfaces 45 and 46 of each mounting hole 37 to which each carrier support member 15 is pressed are surfaces that are substantially orthogonal to each other, each carrier support member 15 is held in a stable state. The position can be determined correctly.
Furthermore, as shown in FIG. 7, when the angle formed by the wedge-shaped portion 53 of each pressing member 44 is θ, if the angle θ is too large, the wedge-shaped portion 53 is press-fitted between the guide surface 50 and the bearing 17. Therefore, a large force is required and the operability is lowered. On the other hand, if the angle θ is too small, the operating stroke of the pressing member 44 is easily increased, and the operability is also lowered. From this viewpoint, it is preferable to set the angle θ to 5 ° to 45 °, particularly 15 ° to 20 °.

  As shown in FIGS. 2 and 7, the two surfaces 45 and 46 of the mounting hole 37 formed in the positioning holding member 32 are formed by tongue pieces 55 and 56 formed by cutting and raising during press molding. In this case, a roundness 57 is formed at the bases of the tongue pieces 55 and 56, so that when the positioning holding member 32 is rotated to the closed position shown in FIG. As a result, it is possible to prevent the bearing 17 from being damaged.

  Similarly, when the surface of the pressing member 44 that comes into contact with the carrier support member 15 is formed by a tongue piece 58 formed by cutting and raising during press molding, as shown in FIG. Since the round portion 60 is formed at the base portion, when the pressing member 44 comes into contact with the bearing 17 of the carrier support member 15, a problem of scratching the bearing can be prevented.

  The image forming apparatus described above includes a plurality of photosensitive drums 6Y to 6BK, and a plurality of pressing members 44 that press the carrier supporting members 15 that support the respective photosensitive drums are respectively provided on a common slide member 41. Since it is supported so as to be movable, all the pressing members 44 are actuated simply by moving the single slide member 41, and each supporting member support member 15 is attached to each of the two mounting holes 37 by the pressing members 44. The surfaces 45 and 46 can be pressed.

  In the illustrated image forming apparatus, the photosensitive drums 6Y to 6BK are fixedly supported on the support shaft 16 of each carrier support member 15, and the support shaft 16 of each carrier support member 15 is rotationally driven. Since each of the photosensitive drums 6Y to 6BK is configured to rotate, a bearing 17 is attached to the front portion of the support shaft 16 of each carrier support member 15, and each of the bearings 17 is loosely fitted in each mounting hole 37. It is configured to match. On the other hand, when each photosensitive drum is rotatably supported on each supporting shaft and the supporting shaft is not rotated, and only the photosensitive drum is rotationally driven, the supporting shaft is directly attached. It can be fitted into the hole. For this reason, it is not necessary to provide the bearing 17 which loosely fits in the attachment hole 37 in the carrier support member in this case.

  Further, in the image forming apparatus of this example, the support shaft 16 is assembled integrally with the photosensitive drums 6Y to 6BK, but each support shaft is assembled to the frame of the image forming apparatus main body so as to be rotatable or non-rotatable. The photosensitive drum can also be assembled to the support shaft so as to be detachable in the axial direction. Such an image forming apparatus can employ the above-described configurations without hindrance. Also in this case, when the support shaft is rotatably supported by the frame, the carrier support member is constituted by the support shaft and a bearing attached to the front side portion thereof, so that the support shaft cannot be rotated. When assembled to the frame, the support shaft can be directly fitted into the mounting hole of the positioning holding member.

  Although the description will be mixed, the positioning and holding member 32, the slide member 41, and each pressing member 44 are formed integrally with each other by sheet metal as a plate material. There is also an advantage and effect that it can be formed while ensuring wear resistance and durability.

Each configuration shown in FIGS. 1 to 7 can be applied to an image forming apparatus provided with only one photosensitive drum without any trouble.
The process cartridge is not limited to the process cartridges 1Y to 1BK. For example, at least one of the photosensitive drums 6Y to 6BK, a charging device 11Y as a charging unit, a developing device 9Y as a developing unit, and a cleaning device 10Y as a cleaning unit. It may consist of a combination of two. The same applies to a second comparative example, each embodiment, and a modified example described later.

(Second comparative example)
8 to 18 show a second comparative example. As compared with the image forming apparatus as the first comparative example shown in FIGS. 1 to 7, the second comparative example replaces the positioning unit 65 with the positioning unit shown in FIGS. The main difference is that 70 is used. Except for the above differences, the image forming apparatus shown in FIGS. 1 to 7 is almost the same.

  As compared with the positioning unit 65, the positioning unit 70 uses a positioning and holding member 32A as a holding member shown in FIGS. 8 to 11 and the like instead of the positioning and holding member 32, and instead of the slide member 41, FIG. 11 and 15, etc., using the slide member 41 </ b> A constituting the pressing means, and using the pressing member 44 </ b> A constituting the pressing means shown in FIGS. 10 to 15 instead of the pressing member 44, stepped The point that the stopper 49 made of a screw is removed, the spring 71 that constitutes the pressing means shown in FIGS. 10 to 16 is used instead of the tension spring 52, and the positioning and holding member 32A is opposed to the slide member 41A. The point that the cover 90 as the cover member shown in FIG. 17 is newly provided on the outside, and the slide member 41A is moved between the first position and the second position. That it has a moving means 92 shown in FIG. 17 to be differs mainly. Other than the above differences, the positioning unit 65 is the same.

When the positioning unit 70 is closed with respect to the opening 31 of the front side plate 28 in the image forming apparatus main body 7 as shown in FIGS. 8 to 11 and 17, etc., the supporting unit is supported by the weight of each process cartridge 1Y to 1BK. Positioning and holding member 32A as a single holding member provided with two surfaces 78 and 79 as holding portions in four open mounting holes 77 for holding member 15, and held by two surfaces 78 and 79. It is mainly comprised from the press means mentioned later which presses and positions each support body support member 15. As shown in FIG.
As in the first comparative example, the positioning holding member 32A, the slide member 41A, and each pressing member 44A are made of sheet metal as a plate material, and each part to be described later is integrally formed. There is also an advantage and effect that it can be formed while ensuring a predetermined strength, wear resistance and durability.

The positioning holding member 32A has a mounting hole 77 formed in place of the mounting hole 37 as compared with the positioning holding member 32, and the description of the positioning holding member 32 is omitted. The main difference is that the strength is improved.
As shown in FIG. 9, the opening mounting hole 77 has a tongue piece 80 provided with two surfaces 78 and 79 as holding parts for holding the carrier support member 15 by its own weight of each process cartridge 1Y to 1BK. 81 is integrally formed. The tongue pieces 80 and 81 having the two surfaces 78 and 79 are formed so as to be substantially orthogonal to each other at substantially the same angle (about 45 °) on both sides with the vertical line as the center. This exhibits the same function as the two surfaces of the V block used for centering the round bar-shaped shaft.

On the other hand, in the holding and positioning of the carrier support member 15 in the mounting hole 37 having the two vertical surfaces 45 and the horizontal surface 46 shown in FIGS. 6 and 7, the process cartridges 1Y to 1BK are supported by their own weight. The mounting / holding state on the two surfaces 45 and 46 of the body support member 15 may not be reliable, and the carrier support member 15 contacts the vertical surface 45 even when the pressing member 44 is pressed. Without being caught on the horizontal surface 46 without being held in the proper position. In this comparative example, this point is also improved.
Similarly to the first comparative example shown in FIG. 7, when the two surfaces 78 and 79 are formed by tongue pieces 80 and 81 formed by cutting and raising during press molding, the tongue pieces 80 and 81 are formed. Since the base portion 81 is rounded, when the positioning holding member 32A is swung in the direction of arrow D shown in FIG. 8 to the closed position, the rounded portion comes into sliding contact with the bearing 17, and the bearing It is possible to prevent a problem that the 17 is scratched.

If such an advantage is not desired, the tongue pieces 80 and 81 may not be formed and may be held by the cutting (shearing) surface of the mounting hole 77 corresponding to the plate thickness. The tongue pieces 80 and 81 are shown only in FIGS. 8 and 9 for the sake of simplicity, and are omitted in other drawings. Further, the shape of the mounting hole 77 is accurately shown only in FIG. 9, and is simplified in a substantially fan shape in the other drawings.
As a matter of course, the dimensional accuracy of the positioning holding member 32A with respect to the frame 33, the pitches of the two surfaces 78 and 79 of each mounting hole 77 of the positioning holding member 32A, and the dimensional accuracy of each portion are determined by the respective photosensitive drums 6Y to 6BK. Needless to say, it is set within a predetermined accuracy range (tolerance) for positioning with respect to the image forming apparatus main body 7.

  As shown in FIG. 17, the cover 90 is integrally formed of, for example, an appropriate resin having a predetermined strength for satisfying its function, and bosses for fastening screws 91 are provided at both left and right ends thereof. 90a is protrudingly formed. On the other hand, holes for inserting the screw 91 are formed at both ends of the positioning holding member 32A, and the cover 90 and the positioning holding member 32A are fastened and fixed by the screw 91. The fixing position of the cover 90 and the positioning holding member 32A by the screw 91 is provided outside the four mounting holes 77 provided with the holding portions. Thereby, the strength of the positioning and holding member 32A is ensured, and particularly effective for improving the strength against torsion.

As shown in FIG. 17, the positioning / holding member 32A has at least one side in the long side direction and the short sides at both ends thereof as a drawn shape 32a, and a flange is formed over the entire circumference. Thereby, the strength of the positioning holding member 32A is more sufficiently ensured.
Further, the support body holding member holding portion 32b of the positioning holding member 32A to the shape 32c that fits to the swing fulcrum (see the hinge pin 34 shown in FIGS. 8 and 9) of the positioning holding member 32A are integrally formed. Yes. And the shape 32c part and the support body supporting member holding part 32b are connected by a flange formed by a drawing shape 32d. Thereby, the strength can be ensured from the swinging fulcrum of the positioning holding member 32A to the carrier support member holding portion 32b.

  As shown in FIGS. 8 to 17, the pressing means of this comparative example is provided corresponding to each carrier support member 15 of each process cartridge 1 </ b> Y to 1 </ b> BK and supports each carrier on each of the two surfaces 78 and 79. A plurality of (four in this comparative example) movable between a non-pressing position that is not in contact with the member 15 and a pressing position that presses and positions each carrier support member 15 on each of the two surfaces 78 and 79. The pressing member 44A, a plurality of U-shaped springs 71 (four in this comparative example) as urging means for urging each pressing member 44A in the direction of moving to the pressing position, and each pressing member 44A are moved. Movable supported by the positioning holding member 32A so as to be movable between the first position shown in FIG. 10 corresponding to the non-pressing position and the second position shown in FIG. 11 corresponding to the pressing position. Single slide member 4 as member It is mainly composed of an A.

The slide member 41A has the guide surface 50 as a guide portion for guiding each pressing member 44A between the non-pressing position and the pressing position, and the pressing member 44A in the non-pressing position when occupying the first position. And a plurality of cut and bent shapes 41a as stopper portions that are regulated and held. The cut and bent shape 41 a also has a function as a first locking portion formed in the vicinity of each mounting hole 77.
As described above, the slide member 41A, compared with the slide member 41 shown in FIG. 6 etc., removes the point where the pin 93 constituting the moving means 92 is implanted and the stopper 49, and cuts and bends 41a. The difference is mainly formed.

Each pressing member 44 </ b> A has a wedge-shaped portion 53 that is press-fitted between the guide surface 50 and each carrier support member 15 on each of the two surfaces 78 and 79 and presses each carrier support member 15. As shown only in FIG. 16, the surface of the pressing member 44 </ b> A that contacts the bearing 17 of the carrier support member 15 is press-molded similarly to the pressing member 44 that is a component of the first comparative example shown in FIG. 7. When formed by the tongue piece 58 formed by the time-raising process, the base of the tongue piece 58 is rounded, so that when the pressing member 44A comes into contact with the bearing 17 of the carrier support member 15 This can prevent the bearing from being damaged.
In FIG. 12, FIG. 13, FIG. 16, etc., the fan-like or circles indicated by the two-dot chain line on the inner surface of the slide member 41A are omitted from the illustration of the positioning and holding member 32A in order to simplify the drawing. And the state where the bearing 17 of the carrier support member 15 virtually exists is projected and shown.

  The pressing member 44A having the tapered wedge-shaped portion 53 similar to that in the first comparative example is a position corresponding to the cut and bent shape 41a of the slide member 41A and within a movement range between the non-pressing position and the pressing position. The formed long hole 44b for movement and the cut and bent shape 44a opposite to the cut and bent shape 41a are formed. The slide member 41A and the pressing member 44A are loosely fitted as indicated by an arrow H in FIG. The slide member 41A and the pressing member 44A are set so that the respective cut and bent shapes 41a and 44a face each other as shown in FIG.

Between the cut and bent shapes 41a and 44a, both ends 71a and 71b of the spring 71, which is a U-shaped urging means and also an elastic member, are hooked and attached, and by the elastic force of the spring 71, The pressing member 44A is held with respect to the slide member 41A, and tension (tension) is applied between the pressing member 44A and the slide member 41A.
The bending angle θ2 as the locking angle for locking the spring 71 of the cut and bent shape 41a of the slide member 41A is set to 45 ° or more with respect to the sliding movement surface of the slide member 41A as shown in FIG. Has been. If the bending angle θ2 is less than 45 °, the hooked shape 71b of the spring 71 is likely to be sandwiched between the cut and bent shape 41a of the slide member 41A and the pressing member 44A, and the movement of the pressing member 44A becomes worse. It is not preferable.

The detailed shape of the spring 71 will be described with reference to FIG. The spring 71 has a substantially U-shape, and both ends thereof are provided with bent shapes 71a and 71b that are hooked to the respective cut and bent shapes 41a and 44a of the slide member 41A and the pressing member 44A. Yes.
The width W1 between the bends of the bent shapes 71a and 71b, which is the width between the opening-side ends of the U-shaped portion of the spring 71, is smaller than the maximum width W2 of the U-shaped portion. Naturally, it has a hook shape so as to be caught. By setting W1 <W2, it is possible to prevent the spring 71 from moving upward as indicated by an arrow in FIG.
Needless to say, the load and the spring constant of the spring 71 are set so as to avoid resonance and the like in consideration of the relationship between the total load and the operating force since four are used in this comparative example. Yes.

According to this comparative example, both ends 71a and 71b of the spring 71 having a substantially U shape are hooked and mounted between the cut and bent shape 41a of the slide member 41A and the cut and bent shape 44a of the pressing member 44A. Thus, the pressing member 44A can be held with respect to the slide member 41A, and the stopper 49 which is the stepped screw of the first comparative example shown in FIG. 7 can be removed. In addition, the use of the spring 71 that is less expensive than the tension spring 52 of the first comparative example shown in FIG. 7 can further reduce the cost.
According to this comparative example, by setting the bending angle θ2 to 45 ° or more, the hooking shape 71b of the spring 71 is not sandwiched between the cut and bent shape 41a of the slide member 41A and the pressing member 44a. The movement of 44A can be made smooth.
Further, according to this comparative example, the width W1 in the opening-side bending of the U-shaped portion of the spring 71 is made smaller than the maximum width W2 of the U-shaped portion (W1 <W2). It is possible to prevent the spring 71 from moving upward as indicated by an arrow in FIG.

As shown in FIGS. 17 and 18, the moving means 92 exhibits the function of moving the slide member 41 </ b> A between the first position and the second position. A lever 94 as an operation member provided on the cover 90 so as to be capable of reciprocating rocking movement in the arrow K direction, and reciprocating rocking movement in the arrow K direction by the lever 94 is converted into a substantially horizontal linear movement that is a moving movement of the slide member 41A. Reciprocating motion converting means.
This reciprocating motion converting means is inserted through a pin 93 planted in the slide member 41A, a long hole 90b formed in the cover 90 in a substantially horizontal direction and through which the pin 93 is inserted, and a hole 90c formed in the cover 90. The lever base end portion 94 a fastened and fixed by the screw 95 and the guide groove 94 b formed in the base portion of the lever 94 into which the pin 93 is inserted are mainly configured.
The reciprocating oscillating motion in the arrow K direction by the lever 94 is such that the pin 93 moves along the guide groove 94b and the pin 93 is substantially horizontal in the elongated hole 90b around the screw 95 of the lever base end portion 94a. By being guided and regulated so as to move along, the slide member 41A is converted into a substantially horizontal linear motion.

Next, the operation of the positioning unit 70 of the second comparative example will be described with reference to FIG. 8 to FIG.
10, as shown in FIG. 8, the process cartridges 1 </ b> Y to 1 </ b> BK are pushed toward the back side indicated by the arrow G of the image forming apparatus main body 7, and the positioning holding member 32 </ b> A is swung to the closed position, and the positioning is performed. The positioning holes 35a and 35b formed in the holding member 32A are fitted to the positioning pins 36a and 36b protruding from the front side plate 28 (see FIGS. 2 and 3), and the positioning holding member 32A is set to a predetermined mounting position. It is a figure which shows a mode when it positions, Comprising: When borrowing FIG. 2 and explaining similarly to a 1st comparative example, it is the figure seen in the arrow IV direction of the figure.
The slide member 41A is formed with a plurality of elongated holes 42 that are long in the horizontal direction, and stepped screws 43 are inserted into the elongated holes 42 so as to be relatively slidable. It is screwed to 32A. Accordingly, the slide member 41A is supported by the positioning holding member 32A so as to be slidable and movable in the horizontal direction between the first position shown in FIG. 10 and the second position shown in FIG.

When the positioning and holding member 32A is swung from the open position shown in FIG. 8 to the closed position shown in FIG. 10, the bearings 17 are fitted into the mounting holes 77 formed in the positioning and holding member 32A. As can be seen from FIG. 10, the size of each mounting hole 77 is set larger than the cross-sectional area of each support shaft 16 and each bearing 17 fitted thereto, and each bearing 17 is larger than each mounting hole 77. Insert with play. For this reason, each bearing 17 can be easily inserted into each mounting hole 77.
On the other hand, each pressing member 44A is provided corresponding to each bearing 17, and each pressing member 44A is slidably contacted and guided by the guide surface 50 with respect to the slide member 41A, and is fitted into the long hole 44b. The predetermined stroke can be moved in the horizontal direction while being guided by the cut and bent shape 41a.

As described above, each end of the U-shaped spring 71 is engaged with the cut and bent shape 44a of each pressing member 44A and the cut and bent shape 41a of the slide member 41A. Thereby, each pressing member 44A is urged to the right in FIG. 10, but when the slide member 41A occupies the first position shown in FIG. 10, as shown in FIG. Due to the urging force of the spring 71, the cut-and-raised base portion of the cut and bent shape 41a of the slide member 41A comes into contact with the right end portion in the drawing of the long hole 44b of the pressing member 44A to act as a stopper, so that each pressing member 44A is a figure. It stops at the position shown in FIG. At this time, each pressing member 44 </ b> A does not contact each bearing 17 of each carrier support member 15.
In this way, each pressing member 44A is slidably supported by the slide member 41A in a state of being biased by the spring 71, and when the slide member 41A is in the first position, the spring biased press The member 44A is restricted by the cut and bent shape 41a provided on the slide member 41A, and is prohibited from contacting the carrier support member 15. Therefore, when the operator manually swings the positioning and holding member 32A from the open position to the closed position shown in FIG. 10, each bearing 17 does not interfere with each pressing member 44A and each mounting It can be inserted into the hole 77.

  Next, the operator opposes the slide member 41A shown in FIG. 10 against the resultant force of the urging forces of the four springs 71 and the frictional resistance of the slide sliding contact portion of each pressing member 44A against the slide member 41A. When the lever 90 shown in FIGS. 17 and 18 is operated to slide to the right to occupy the second position shown in FIG. 11, the wedge-shaped portion 53 of each pressing member 44A is guided. It press-fits between the surface 50 and each bearing 17 of each carrier support member 15, and presses each bearing 17 against the two surfaces 78 and 79 that define each mounting hole 77. The operation at this time will be described in more detail below.

When the slide member 41A starts to move from the first position shown in FIG. 10 to the second position shown in FIG. 11, the cutting member urged by each spring 71 and fitted into the long hole 44b. Each pressing member 44A regulated by the bent shape 41a starts to move to the right in FIG. 10 together with the slide member 41A. Next, when the slide member 41A reaches a predetermined position between the first position and the second position, the wedge-shaped portion 53 of each pressing member 44A urged by each spring 71 has the guide surface 50 and each carrier. It is press-fitted between the bearings 17 of the support member 15, presses against the outer peripheral surface of each bearing 17 and stops. Thereby, each pressing member 44 </ b> A strongly presses each bearing 17 against the two surfaces 78 and 79 of each mounting hole 77.
Even after each pressing member 44A stops, when the slide member 41A is moved toward the second position against the urging force of each spring 71, each end of the long hole 44b formed in each pressing member 44A. The part is separated from each cut and bent shape 41a, and each pressing member 44A is released from the restriction by each cut and bent shape 41a.

As described above, the bearings 17 are pressed against the two surfaces 78 and 79 of the mounting holes 77 by the pressing force of the wedge-shaped portions 53 of the pressing members 44 </ b> A urged by the springs 71. The member 15 and the front side portions of the photosensitive drums 6Y to 6BK supported by the member 15 are correctly positioned with respect to the positioning holding member 32A. At this time, referring to FIG. 8 with reference to FIG. 2, since the positioning holding member 32A is correctly positioned with respect to the frame 33, each of the photosensitive drums 6Y to 6BK eventually becomes the image forming apparatus main body 7. Is correctly positioned with respect to the frame 33 of the frame. The operator simply attaches the positioning holding member 32A to the frame 33 at a predetermined position and operates the lever 90 to move the slide member 41A, so that the photosensitive drums 6Y to 6BK are moved relative to the image forming apparatus main body 7. Can be positioned. In addition, the size of the mounting hole 77 formed in the positioning and holding member 32A can be set larger than the cross-sectional area of the front end portion of the carrier support member 15, so that each carrier support member 15 can be attached smoothly and easily. It can be inserted into the hole 77.
As a matter of course, the dimensional accuracy of the positioning holding member 32A with respect to the frame 33, the pitches of the two surfaces 78 and 79 of each mounting hole 77 of the positioning holding member 32A, and the dimensional accuracy of each portion are determined by the respective photosensitive drums 6Y to 6BK. Needless to say, it is set within a predetermined accuracy range (tolerance) for positioning with respect to the image forming apparatus main body 7.

  As described above, the pressing means is provided corresponding to each carrier support member 15, and is in a non-pressing position and each holding that is not in contact with each carrier support member 15 on each holding portion (two surfaces 78, 79). A plurality of pressing members 44A movable between the pressing positions for pressing and positioning each carrier support member 15 on the portion (two surfaces 78, 79), and in a direction to move each pressing member 44A to the pressing position. A spring 71 as a biasing means for biasing and each pressing member 44A are movably supported, and are movable between a first position corresponding to the non-pressing position and a second position corresponding to the pressing position. And a single slide member 41A supported by the positioning and holding member 32A, and a moving means 92 for moving the slide member 41A between the first position and the second position.

  According to the second comparative example, with the above-described configurations, the operability is superior to that of the first comparative example, and the cost can be reduced. And the position of each component etc. is set so that the following operation | movement may be performed also in a 2nd comparative example. That is, when the slide member 41A is in the first position, each pressing member 44A biased by each U-shaped spring 71 is regulated by each cut and bent shape 41a as a stopper portion of the slide member 41A. When the sliding member 41A is moved from the first position toward the second position while being in contact with the carrier support members 15 on the two surfaces 78 and 79, the U-shaped springs 71 are used. When each pressing member 44A energized and regulated by each cutting and bending shape 41a moves together with the slide member 41A, each slide member 41A reaches a position between the first position and the second position. Each pressing member 44 </ b> A biased by the U-shaped spring 71 is stopped when its wedge-shaped portion 53 is press-fitted between the guide surface 50 and each carrier support member 15 on each of the two surfaces 78 and 79. And As the id member 41A further moves toward the second position, the slide member 41A, each press member 44A, and each U-shape are released so that each press member 44A is released from the regulation by each cut and bent shape 41a. The positions of the spring 71 and the cut and bent shapes 41a are set.

According to this comparative example, as in the first comparative example described above, when the slide member 41 is made to occupy the second position shown in FIG. 11, the wedge-shaped portion 53 of each pressing member 44A is guided by the guide surface. 50 and the outer peripheral surface of each bearing 17, the carrier support member 15 is held in a normal position by the frictional force and the biasing force of the spring 71, and the photosensitive drums 6 </ b> Y to 6 </ b> BK are held in place. It is possible to continue positioning correctly. Further, if the slide member 41A is manually returned to the first position shown in FIG. 10, each pressing member 44A is separated from the outer peripheral surface of each bearing 17, so that the positioning holding member 32A is not hindered. Can be swung to the open position shown in FIG.
It goes without saying that according to this comparative example, the same advantages and effects as those of the first comparative example can be obtained with respect to a portion having the same configuration as that of the first comparative example except for the characteristic configuration described above. Yes. That is, when the positioning unit 70 is closed with respect to the image forming apparatus main body 7, the process cartridges 1 Y to 1 BK (image carrier unit) are placed on the two surfaces 77 and 79 (holding portions) of the opening mounting hole 77 by the own weight. After the bearing 17 (the carrier support member 15) is held, the bearings 17 on the two surfaces 77 and 79 are pressed and positioned by the pressing means, so that the process cartridges 1Y to 1BK can be imaged with a simple positioning configuration. It is possible to provide an image forming apparatus that can be correctly positioned with respect to the apparatus main body 7 and that can improve its operability and reduce costs.

(Third comparative example)
With reference to FIG. 23 to FIG. 27, a configuration related to improvement in positioning accuracy of the positioning unit 70 with respect to the image forming apparatus main body 7 will be described. In the third comparative example, the positioning method by fitting the positioning pins 36a and 36b and the positioning holes 35a and 35b of the first and second comparative examples shown in FIGS. 3 and 8 is improved.
That is, in the third comparative example, the positioning holes 35a and 35b of the first and second comparative examples are compared with the positioning method of the positioning unit 70 with respect to the image forming apparatus main body 7 of the first and second comparative examples. Instead, as shown in FIGS. 23 to 25, holes 72a and 72b having a shape in which a round hole and a long hole are connected to each other are formed at both ends of the slide member 41A (the right end is not shown). When the slide member 41A occupies the first position, the holes 73a and 73b as positioning recesses are positioned at positions corresponding to the round holes 72a and 72b at both ends (right end portions) of the positioning holding member 32A. And an image forming apparatus corresponding to each of the holes 72a, 72b, 73a, and 73b instead of the positioning pins 36a and 36b of the first and second comparative examples. Of the body 7 In a fixed position, the positioning pin 74a as the positioning projection and the positioning shaft, the point that 74b is provided to mainly differs.

The third comparative example is the same as the first and second comparative examples except for the above differences. For example, as shown in FIGS. 23 and 24, the positioning holding member 32A has an arrow La direction ( A slide member 41A that slides in a substantially horizontal direction is also provided.
The following supplements the explanation in the background art. The positioning pins 74a and 74b are formed of a metal such as steel, for example, like the positioning pins 36a and 36b of the first and second comparative examples, and are implanted and fixed at a predetermined position of the image forming apparatus main body 7. Has been. Here, the positioning convex portion is not limited to the positioning pins 74a and 74b as positioning shafts, and if it is not necessary to use a simple and inexpensive one, for example, the front plate 28 of the image forming apparatus main body 7 (see FIG. 8). ) And a convex portion formed so as to protrude integrally. Similarly, the positioning recess is not limited to the holes 73a and 73b, and may be a recess that can be fitted to the protrusion, for example.
As shown in FIG. 24, the positioning and holding member 32A is swung in the direction of arrow D and closed with respect to the image forming apparatus main body, whereby the positioning pin 74b enters the hole 73b and the hole 72b. At this time, the slide member 41A occupies the first position.
By sliding the slide member 41A in the direction of the arrow La and moving it to the second position, the groove 74d of the positioning pin 74b and the elongated hole 72b are loosely fitted, whereby the positioning holding member 32A is moved to the image forming apparatus main body side. Fixed. Thereby, the positioning holding member 32A (positioning unit 70) can be positioned and fixed with respect to the image forming apparatus main body.

  By forming a tapered portion 74c having a chamfered shape as shown in FIGS. 24 and 25 at the tip of the positioning pin 74b, the positioning pin 74b can easily enter the holes 73b and 72b of the positioning holding member 32A and the slide member 41A. can do. Further, by forming a tapered portion having a similar chamfered shape in a portion of the positioning pin 74b in front of the groove 74d, in other words, a portion of the positioning pin 74b on the side where the long hole 72b of the slide member 41A is fitted. 41A can make it easy to slide fit.

  FIG. 27 shows the positional relationship between the positioning and holding member 32A and the front plate 28 provided on the image forming apparatus main body side. The positioning holding member 32A can swing and open / close about a hinge pin 34 as a swing fulcrum. The fulcrum is provided at a position outside the surface that contacts the positioning pin 74 of the positioning holding member 32A. That is, in FIG. 27, it can be seen that N is located outside of M. Thereby, it is possible to prevent the positioning and holding member 32A from falling to the front side on the left side in the drawing.

  The positioning holding member 32A is temporarily fixed by a magnet catch 76 as a temporary fixing means for temporarily fixing the positioning holding member 32A to the position when the positioning pin 74b is fitted and set in the positioning hole 73b and closed. Can do. The temporary fixing means may be a latch, a leaf spring or the like in addition to the magnet catch. By providing the temporary fixing means, it is possible to prevent the positioning and holding member 32A from falling to the front side on the left side in the drawing more reliably than the above-described configuration.

(First embodiment)
The first embodiment will be described with reference to FIGS. 19 and 20. FIG. 19 shows the left half of the positioning and holding member 32A in the first embodiment.
In the first embodiment, as shown in FIGS. 19 and 20, the positioning unit 70 is opened with respect to the image forming apparatus main body as compared with the second comparative example shown in FIGS. 8 to 18. At this time, a positioning member 70 is provided on the positioning holding member 32A in a state to be described later on the positioning holding member 32A, and the positioning unit 70 is provided with respect to the image forming apparatus main body. When closed, the movement restriction release means for releasing the slide / movement restriction of the slide member 41A to the second position by the restriction member 85 and the pin 88 as the convex portion are provided on the front plate 28 on the image forming apparatus main body side (see FIG. 8). When the positioning unit 70 is closed with respect to the image forming apparatus main body, a hole 89 as a recess that can be fitted with the pin 88 is formed in the positioning holding member 32A. It is in and that is, and that it has a coil spring 87 (compression spring) of the regulating member 85 as biasing means for regulating member for always urging in the direction of arrow D differs mainly. The first embodiment is the same as the image forming apparatus of the second comparative example except for the above differences.

The positioning holding member 32A and the slide member 41A in the positioning unit 70 shown in FIGS. 19 and 20 are in a state in which the positioning holding member 32A occupies the open position and the slide member 41A occupies the first position. That is, when the photosensitive drum is replaced, the slide member 41A is slid to the left with respect to the positioning holding member 32A, and each pressing member (not shown) is released from the bearing 17 of the photosensitive drum.
In the positioning and holding member 32A, a regulating member 85 that regulates the sliding of the slide member 41A to the second position is provided in the direction of the arrow C, with a fulcrum shaft 86 provided rotatably on the positioning and holding member 32A as a swinging fulcrum. It is provided so as to be swingable / displaceable in the direction of arrow D. That is, as shown in both figures, when the slide member 41A occupies the first position, the regulating member 85 blocks the hole 89 and engages the slide member 41A to bring the slide member 41A to the first position. The restriction position to be held and the non-regulation position in which the engagement state with the slide member 41A is released by allowing the pin 88 and the hole 89 to be engaged and engaged to allow the slide member 41A to move to the second position. Can be swung and displaced between.

The restricting member 85 and the slide member 41A are both formed of a metal plate member such as a sheet metal (steel plate), and the surfaces in the thickness direction of each other, that is, the end face 85a of the restricting member 85 and the slide member 41A. The end surfaces 41Aa are formed and arranged in such a shape that they are in contact with each other.
In addition, as shown in FIG. 20, the regulating member 85 always positions the regulating member 85 by a coil spring 87 that is an elastic member provided between the right side surface and the inner wall surface of the cover 90 in the diagram of the regulating member 85. It is biased in the direction of pressing against the holding member 32A. That is, the biasing force of the coil spring 87 is set in the direction of the arrow La shown in FIG. 19 of the slide member 41A, that is, the direction orthogonal to the slide / movement direction.
The restricting member urging means is not limited to the coil spring 87 but may be a leaf spring, for example.

  As shown in FIG. 8, the positioning and holding member 32A swings in the direction of the arrow D with respect to the image forming apparatus main body 7. The positioning holes 35a and 35b of the positioning and holding member 32A are front plates on the image forming apparatus main body 7 side. 28 is fitted to the positioning pins 36a and 36b implanted in 28, and is temporarily set via the temporary fixing means or the like in the third comparative example. At this time, when the pin 88 shown in FIG. 19 is fitted into the hole 89, the regulating member 85 is pushed in the direction of swinging in the direction of the arrow C against the urging force of the coil spring 87, whereby the regulating member 85 occupies a non-restricted position allowing the slide member 41A to move to the second position, and the holding / fixed state of the first position of the slide member 41A by the restricting member 85 is released.

As described above, according to the present embodiment, when the positioning unit 70 is opened with respect to the image forming apparatus main body 7, the slide member 41A is moved to the second position by the restriction member 85 as the restriction means. Therefore, the slide member 41A is held and fixed at the first position, and for example, it is possible to prevent the user or serviceman from accidentally setting the slide member 41A to the second position. When the positioning unit 70 is closed with respect to the image forming apparatus main body 7, interference between the bearing 17 of the carrier supporting member 15 and each pressing member 44A (omitted in FIGS. 19 and 20) can be avoided. Therefore, the positioning unit 70 can be smoothly attached to the image forming apparatus main body 7.
Further, according to the present embodiment, when the slide member 41A occupies the first position, the restricting member 85 blocks the hole 89 and engages the slide member 41A to bring the slide member 41A to the first position. The restriction position to be held, and the pin 88 and the hole 89 are fitted and engaged and the head of the pin 88 passes, so that the engagement state with the slide member 41A is released, and the second position of the slide member 41A. When the positioning unit 70 is closed with respect to the image forming apparatus main body 7, a pin 88 serving as a movement restriction release means is inserted into the hole 89. By pushing, the restriction of movement of the slide member 41A to the second position by the restriction member 85 is surely released, and thus the above-described effect is more reliably achieved.

According to the present embodiment, the regulating member 85 and the slide member 41A are both formed of metal plate-like members, and are formed and arranged in such a shape that the surfaces in the plate thickness direction are in contact with each other. Therefore, even if the slide member 41A is slid and moved with a strong force, the restriction member 85 and the slide member 41A can be prevented from being damaged.
Further, according to the present embodiment, since the regulating member 85 is always urged in the direction occupying the regulated position by the coil spring 87 as the regulating member urging means, the first of the slide member 41A by the regulating member 85 is provided. Holding and fixing to the position of is more reliable.

  According to the present embodiment, the urging force by the coil spring 87 is set in a direction orthogonal to the sliding / moving direction of the slide member 41A. For example, the urging force is set along the moving direction of the slide member 41A. Compared with the case, it requires less biasing force.

The embodiment of the present invention is not limited to the first embodiment described above, and may be modified as follows. That is, the head of the positioning pin 36b passes through the positioning hole 35b, and a regulating member (not shown) is pushed in the direction of arrow C to swing, thereby causing the regulating member to occupy the non-regulating position, and sliding by the regulating member. It is also possible to release the holding / fixing state of the first position of the member 41A.
Although not specifically illustrated, when the slide member 41A occupies the first position, a restriction position that blocks the positioning hole 35b and engages the slide member 41A to hold the slide member 41A in the first position; When the positioning pin 36b and the positioning hole 35b are engaged with each other, the engagement state with the slide member 41A is released, and the position of the slide member 41A is swung between the non-restricted position allowing the movement to the second position. -It is also possible to comprise the said control member so that displacement is possible. When the positioning unit 70 is closed with respect to the image forming apparatus main body 7, the head of the positioning pin 36b is fitted and passed through the positioning hole 35b, and the regulating member is pushed and swung in the direction of the arrow C. It is also possible for the restricting member to occupy the non-regulating position.
According to this modification, since the positioning pin 36b serving as the positioning convex portion also serves as the movement restriction releasing means, a special movement restriction releasing means is not required, and there is an advantage and effect that it is possible to save costs.

(Second Embodiment)
The second embodiment will be described with reference to FIGS. 21 and 22. Compared with the positioning method of the positioning unit 70 in the third comparative example shown in FIGS. 23 to 27, the second embodiment replaces the positioning pins 74a and 74b with the slide member 41A and the positioning holding member 32A. The only difference is that positioning protrusions and positioning pins 96a, 96b as positioning shafts are provided at predetermined positions of the image forming apparatus body 7 corresponding to the holes 72a, 72b, 73a, 73b. The second embodiment is the same as the image forming apparatus of the third comparative example except for the above differences.
Since the positioning pin 96a and the positioning pin 96b have the same shape and dimensions, the left positioning pin 96b will be described as a representative in the drawing, but the same applies to the right positioning pin 96a in the drawing. The positioning pins 96b are formed of a metal such as steel, for example, like the positioning pins of the first to third comparative examples, and are implanted and fixed at a predetermined position of the image forming apparatus main body 7. Here, the positioning convex portion is not limited to the positioning pins 96a and 96b serving as the positioning shafts, and is a convex portion formed integrally with the front plate 28 (see FIG. 8) of the image forming apparatus main body 7, for example. Also good.

The positioning pin 96b includes a taper portion 96c formed at the tip portion thereof so as to be guided by the positioning hole 73b serving as a positioning recess and tapering toward the tip portion, and a positioning hole 73b extending from the terminal end of the taper portion 96c. A continuous surface portion 96f that is formed up to the portion to be fitted and has substantially the same outer diameter, and a groove portion 96d that is formed in a part of the continuous surface portion 96f so as not to obstruct the entire outer periphery of the continuous surface portion 96f. And the fitting part 96e finally fitted with the positioning hole 73b is integrally formed.
The groove portion 96d has two flat portions that are substantially parallel to the slide / movement direction of the slide member 41A indicated by the arrow La direction, and these flat portions have two planar shapes parallel to each other.

As shown in FIG. 21, the positioning and holding member 32A is swung in the direction of arrow D and closed with respect to the main body of the image forming apparatus, so that the tapered portion 96c of the positioning pin 96b first enters the positioning hole 73b of the positioning and holding member 32A. The continuous member 96f is inserted while being guided, and the continuous surface portion 96f is inserted while being guided into the hole 73b. Finally, the fitting portion 96e is fitted into the positioning hole 73b, so that the slide member 41A is in the first position. The positioning holding member 32A (positioning unit 70) is positioned with respect to the image forming apparatus main body.
At this time, the slide member 41A occupies the first position, and even if the positioning holding member 32A, the slide member 41A, etc. (positioning unit 70) are slightly lowered due to their own weight or the like, Since the continuous surface portion 96f formed with the same outer peripheral diameter from the end of the taper portion 96c to the fitting portion 96e is guided by the positioning hole 73b, it fits in the groove portion 96d even before reaching the fitting portion 96e. The fitting portion 96e can be smoothly and reliably fitted into the positioning hole 96b without being inserted.
Next, by sliding the slide member 41A in the direction of the arrow La and moving it to the second position, the groove portion 96d that forms a flat portion on the top and bottom of the positioning pin 96b and the elongated hole 72b are loosely fitted to each other, thereby positioning the holding member. 32A is fixed to the image forming apparatus main body side. Accordingly, the slide holding member 41A can position and fix the positioning holding member 32A (positioning unit 70) in the second position with respect to the image forming apparatus main body.

  According to the present embodiment, the positioning pin 96b is formed between the end of the taper portion 96c and the portion that fits with the positioning hole 73b, and has a continuous surface portion 96f having substantially the same outer diameter, and the continuous surface portion 96f. When the positioning holding member 32A (positioning unit 70) is slightly lowered due to its own weight or the like by providing the groove 96d formed in a part of the continuous surface portion 96f so as not to block the entire outer periphery of Even so, since the continuous surface portion 96f of the positioning pin 96b is guided by the positioning hole 73b, it does not get stuck in the groove portion 96d even before reaching the fitting portion 96e, so The fitting part 96e can be smoothly and reliably fitted. It goes without saying that the positioning pin 96b can easily enter the holes 73b and 72b of the positioning holding member 32A and the slide member 41A by the chamfered tapered portion 96c formed at the tip of the positioning pin 96b.

In the comparative example and the like, the tandem type image forming apparatus that transfers the image to the intermediate transfer member and then transfers the image to the sheet-like recording medium is described as an example. However, the sheet-like recording medium is transferred by an endless belt as a recording medium conveying unit. The present invention can be similarly applied and implemented in a tandem color image forming apparatus of a direct transfer system that sequentially transfers and superimposes while being conveyed. An example of this is shown in FIG. 1 of JP-A-11-95565. That is, the present invention can also be applied to an image forming apparatus in which an image on at least one image carrier is directly or indirectly transferred to a sheet-like recording medium.
The present invention can also be applied to, for example, an image forming apparatus using an image carrier unit positioning method described in Japanese Patent Application Laid-Open No. 2001-222207 (Patent Document 6).

  As described above, the present invention has been described with respect to specific comparative examples, embodiments, and the like, but the technical scope disclosed by the present invention is limited to those exemplified in the above-described comparative examples, embodiments, and the like. However, those skilled in the art can configure various embodiments, modifications, and examples according to the necessity and application within the scope of the present invention. it is obvious.

1 is a schematic cross-sectional view of an image forming apparatus to which the present invention is applied. It is sectional drawing which shows the photosensitive drum in a 1st comparative example, and the structure which supports this, Comprising: It is the figure which abbreviate | omitted and showed one part element. FIG. 5 is a perspective view schematically illustrating a frame, a process cartridge, and a positioning and holding member of an image forming apparatus main body in a first comparative example. It is a front view which shows the positioning holding member in the closed position in the 1st comparative example, and the slide member which occupied the 1st position. It is a front view which shows the positioning holding member in the closed position in the 1st comparative example, and the slide member which occupied the 2nd position. It is a disassembled perspective view of the slide member in the 1st comparative example, a positioning holding member, and a process cartridge. FIG. 10 is a perspective view when a positioning holding member and a slide member are viewed from the inside of the image forming apparatus main body in the first comparative example. FIG. 10 is a perspective view illustrating an outline of a frame, a process cartridge, and a positioning and holding member of an image forming apparatus main body in a second comparative example. It is a front view around the attachment hole of the positioning holding member of the positioning unit in the second comparative example. It is a front view which shows the positioning holding member in the closed position in the 2nd comparative example, and the slide member which occupied the 1st position. It is a front view which shows the positioning holding member in the closed position in the 2nd comparative example, and the slide member which occupied the 2nd position. It is a disassembled perspective view which shows the attachment state of the positioning holding member in a 2nd comparative example, and a press member. It is a disassembled perspective view which shows the attachment state of the positioning holding member in a 2nd comparative example, a press member, and a spring. It is a plane sectional view of the important section explaining the bending angle of the cut and bent shape of the slide member and the mounting relationship with the spring. It is a figure explaining the detailed shape of a spring. It is a perspective view of the principal part which shows the state which attached the positioning holding member in the 2nd comparative example, the press member, and the spring. It is a disassembled perspective view around the positioning holding member, the slide member, and the cover member that constitute the positioning unit in the second comparative example. It is a figure which shows operation | movement of a lever. It is a perspective view of the principal part which shows the attachment and operation | movement relationship with the positioning holding member in 1st Embodiment, a slide member, a control member, and a positioning pin. It is sectional drawing of the principal part of FIG. It is a perspective view of the principal part which shows the attachment and operation | movement relationship with the positioning holding member, slide member, and positioning pin in 1st Embodiment. (A) is a front view of the positioning pin in 1st Embodiment, (b) is a top view of the positioning pin, (c) is a right view of the positioning pin. It is a front view of the principal part which shows the positioning relationship of the positioning hole of the positioning holding member in a 3rd comparative example, and a slide member. It is a perspective view of the principal part which shows the positioning state by the positioning pin of the positioning holding member and slide member in a 3rd comparative example. It is an expanded sectional view of the principal part which shows the state which the positioning pin fitted normally to the positioning hole of the positioning holding member in a 3rd comparative example. It is a figure which shows the conventional problem, Comprising: It is an expanded sectional view of the principal part which shows the malfunction state in which the groove | channel of the positioning pin was caught in the positioning hole of the positioning holding member in a 3rd comparative example. FIG. 10 is a side view showing a positional relationship between a positioning and holding member and an image forming apparatus main body and temporary fixing means in a third comparative example.

Explanation of symbols

1Y, 1C, 1M, 1BK Process cartridge (image carrier unit)
6Y, 6C, 6M, 6BK Photosensitive drum (image carrier)
7 Image forming apparatus body 15 Support member support member 16 Support shaft (rotary shaft)
17 Bearing 32A Positioning holding member (holding member)
41A Slide member (movable member)
44A pressing member 78, 79 surface (holding part)
49 Stopper 50 Guide surface (guide part)
53 Wedge-shaped part 70 Positioning unit 71 U-shaped spring 73a, 73b Positioning hole (positioning recess)
77 Mounting hole (opening)
85 Restriction member (regulation means)
87 Coil spring (biasing means for regulating member)
88 pins (moving regulation release means)
90 Cover (cover member)
92 Moving means 94 Lever (operating member)
96a, 96b Positioning pin (positioning convex part, movement restriction release means)
96c taper part 96d groove part (groove part provided with flat part)
96e Fitting part 96f Continuous surface part P Transfer paper (an example of a sheet-like recording medium)

Claims (10)

At least one image carrier unit comprising an image carrier and a carrier support member for supporting the image carrier, and the at least one image carrier unit on the image forming apparatus main body via the carrier support member. An openable and closable positioning unit for detaching and positioning with respect to the image forming apparatus main body, the positioning unit holding at least one opening for holding the carrier support member when closed with respect to the image forming apparatus main body. A holding member provided with a portion, a first position that does not press the carrier support member on the at least one holding portion, and a second position that presses the carrier support member on the at least one holding portion. A movable member supported by the holding member so as to be movable between the image and the image on the at least one image carrier is directly or indirectly transferred to a sheet-like recording medium. An image forming apparatus,
An image forming apparatus, wherein the holding member is provided with restricting means for restricting movement of the movable member to the second position when the positioning unit is open to the image forming apparatus main body. .   2. The movement restriction release means for releasing movement restriction of the movable member to the second position by the restriction means when the positioning unit is closed with respect to the image forming apparatus main body. Image forming apparatus. The image forming apparatus main body is provided with a convex portion that can be engaged with the holding member when the positioning unit is closed with respect to the image forming apparatus main body.
The holding member is provided with a concave portion that engages with the convex portion,
The restricting means, when the movable member occupies the first position, blocks the concave portion and engages the movable member to hold the movable member in the first position; and the convex portion And the concave portion is engaged, and the engagement state with the movable member is released, and the restriction member is displaceable between a non-restriction position allowing the movement of the movable member to the second position. ,
The movement restriction release means includes the convex portion, and when the positioning unit is closed with respect to the image forming apparatus main body, the convex portion engages with the concave portion, whereby the restriction member is moved to the non-restricted position. The image forming apparatus according to claim 2, wherein the image forming apparatus is displaced. The convex portion includes a positioning convex portion for positioning the positioning unit with respect to the image forming apparatus main body.
The concave portion comprises a positioning concave portion that fits with the positioning convex portion,
The restricting means is configured to block the positioning recess and engage the movable member to hold the movable member at the first position when the movable member occupies the first position, and the positioning A restriction that can be displaced between a non-restricted position that allows the movable member to move to the second position by releasing the engaged state with the movable member by fitting the convex portion and the positioning concave portion. Consisting of parts,
The movement restriction release means includes the positioning convex portion, and when the positioning unit is closed with respect to the image forming apparatus main body, the positioning convex portion is engaged with the positioning concave portion, whereby the restriction member is The image forming apparatus according to claim 3, wherein the image forming apparatus is displaced to a non-regulating position.   The regulation member and the movable member are both formed of a metal plate-like member, and are formed and arranged in such a shape that surfaces in the thickness direction of each other are in contact with each other. The image forming apparatus according to 3 or 4.   6. The image forming apparatus according to claim 3, further comprising a regulating member urging unit that urges the regulating member in a direction in which the regulating position is occupied.   7. The image forming apparatus according to claim 6, wherein the urging force by the restricting member urging means is set in a direction orthogonal to the moving direction of the movable member. At least one image carrier unit comprising an image carrier and a carrier support member for supporting the image carrier, and the at least one image carrier unit on the image forming apparatus main body via the carrier support member. An openable and closable positioning unit for detaching and positioning with respect to the image forming apparatus main body, the positioning unit holding at least one opening for holding the carrier support member when closed with respect to the image forming apparatus main body. A holding member provided with a portion, a first position that does not press the carrier support member on the at least one holding portion, and a second position that presses the carrier support member on the at least one holding portion. A movable member supported by the holding member so as to be movable between the image and the image on the at least one image carrier is directly or indirectly transferred to a sheet-like recording medium. An image forming apparatus,
The image forming apparatus main body is provided with a positioning projection for positioning the positioning unit with respect to the image forming apparatus main body when the positioning unit is closed with respect to the image forming apparatus main body.
The holding member is provided with a positioning recess for fitting with the positioning protrusion when the positioning unit is closed with respect to the image forming apparatus main body.
The positioning convex portion is formed at a tip portion thereof to be guided to the positioning concave portion and is tapered toward the tip portion, and from a terminal end of the taper portion to a portion where the positioning concave portion is fitted. And a continuous surface portion having substantially the same outer diameter and a groove portion formed in a part of the continuous surface portion so as not to obstruct the entire outer periphery of the continuous surface portion. Image forming apparatus.   The image forming apparatus according to claim 8, wherein the groove portion includes at least one flat portion substantially parallel to a moving direction of the movable member.   The image forming apparatus according to claim 9, wherein the at least one flat portion has two planar shapes parallel to each other.

Images