JP2008083342A - Component positioning device for image forming apparatus, image forming apparatus, component locating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To replace each component more easily at a lower cost while maintaining the position of the component precisely by eliminating cumulative tolerance in assembly, etc. <P>SOLUTION: A gear ash 37 is mounted on a main frame 35 by precisely positioning the developing drive shaft 34a of a developing drive gear 34 by means of, for example, a positioning tool or the like. Then, a position memory member 47 memorizes the center locations of the rotation shaft 53a of an intermediate gear 53 and the rotation shaft 54a of an intermediate gear 54 and they are mounted on the main frame 35. When the gear ash 37 is re-fitted to the main frame 35 after detached from it, this is carried out while the centers of the rotation shafts 53a and 54a are set in positions memorized by the position memory member 47. This makes it possible to easily re-fit the developing drive shaft 34a of the gear ash 37 in the main frame 35 while keeping the position precisely. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technical field of a component positioning apparatus in an image forming apparatus, for example, an image forming apparatus including an electrophotographic apparatus, and a component positioning method in the image forming apparatus.

  A full-color image forming apparatus including a rotary developing device includes a rotary unit to which four color developing cartridges (developing devices) are respectively mounted (for example, see Patent Document 1). In this rotary developing device, the rotary unit is rotated to set the developing cartridge to be developed at the developing position. In developing, in order to drive the developing cartridge, power is supplied to the developing cartridge from driving means such as a motor provided in the apparatus main body. In this case, power is transmitted from a developing drive gear provided in the apparatus main body to a developing input gear of the developing cartridge.

By the way, a rotary developing device is required to accurately and smoothly transmit power to a developing cartridge in order to perform good image formation. The development input gear meshes with the development drive gear at the development position and disengages at the non-development position. To meet these requirements, the accuracy between the axes of the development input gear and the development drive gear is increased. It is necessary to secure. For this purpose, the developing drive gear needs to be positioned with high accuracy in the apparatus main body.
Therefore, conventionally, the development driving gear is positioned with high accuracy with respect to the main frame of the apparatus main body using a positioning jig.

In addition, other positioning is known in a conventional image forming apparatus (see, for example, Patent Document 2). In the positioning disclosed in Patent Document 2, the support shaft of the photosensitive member is positioned with high accuracy on the support plate of the motor and provided integrally. The motor support plate is positioned with high accuracy in the main frame by being inserted into the positioning holes of the main frame.
JP2003-15409A. JP-A-5-127442.

  However, in positioning using the positioning jig, each time the development drive gear is replaced, a new development drive gear must be positioned with the positioning jig. Necessary. Moreover, the positioning operation by the positioning jig is troublesome, and it takes a lot of time and time to replace the developing drive gear.

  In the positioning disclosed in Patent Document 2, the accumulated tolerance of assembly or the like increases due to the tilting assembly of the support shaft of the photosensitive member with respect to the support plate, and it is difficult to perform positioning with high accuracy. In addition, since the support shaft of the photosensitive member is integrally provided on the support plate of the motor, the support shaft of the photosensitive member must be replaced when replacing the motor or power transmission system components. For this reason, useless parts exchange is performed and cost becomes high.

  The present invention has been made in view of such circumstances, and its purpose is to make it easier and less expensive to replace parts while suppressing the accumulated tolerance of assembly and the like and maintaining the position of the parts with high accuracy. It is an object of the present invention to provide a component positioning apparatus, an image forming apparatus, and a component positioning method in an image forming apparatus, which can be performed at the same time.

  In order to solve the above-described problems, a component positioning apparatus and a component positioning method in an image forming apparatus according to the present invention include a second component that is positioned with respect to a first component and attached to a main frame. A position memory member for storing the attachment position is attached to the main frame. Now, it is assumed that the second part is removed from the main frame when the second part is replaced or another part is replaced. When the new second part is assembled to the main frame or when the removed second part is reassembled to the main frame, the second part can be made of the position memory member without using a special positioning jig. It can be easily and accurately positioned and assembled to the main frame. Thereby, the precision between parts of the 1st and 2nd parts can be ensured easily and with high precision.

In this case, since the position memory member stores the mounting position of the second component that is positioned and mounted with high accuracy, the second component can be positioned with high accuracy by eliminating cumulative tolerances such as assembly. It can be maintained and assembled to the main frame. Moreover, since only the parts that need to be exchanged are exchanged, the parts can be exchanged easily and inexpensively.
Also, according to the image forming apparatus provided with the component positioning device of the present invention, the replacement of the components can be performed easily and with high accuracy, so that a high-quality image can be obtained over a long period of time.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram schematically illustrating an example of an image forming apparatus including an example of an embodiment of a rotary developing device according to the present invention.

  As shown in FIG. 1, the image forming apparatus 1 of this example is configured as a full-color printer. The image forming apparatus 1 includes a photoreceptor 2 which is an image carrier that carries an electrostatic latent image and a toner image. The photosensitive member 2 is a conventionally known photosensitive member, and has a cylindrical conductive base material and a photosensitive layer formed on the outer peripheral surface thereof (not shown). An electrostatic latent image and a toner image are formed on the photosensitive layer. The photosensitive member 2 can rotate in the clockwise direction indicated by an arrow in FIG. 1 around its central axis during operation.

  Around the photosensitive member 2, a charging device 3, an exposure device 4, a rotary developing device 5, a primary transfer device 6, an intermediate transfer member 7, and a cleaning device 8 are arranged in this order toward the downstream side in the rotation direction of the photosensitive member 2. It is arranged. Further, the image forming apparatus 1 includes a paper feed tray 9, a secondary transfer device 10, a fixing device 11, a paper discharge tray 12, a display device 13, and a control device 14.

The charging device 3 is a conventionally known charging device that uniformly charges the photoreceptor 2. The exposure device 4 is a device that forms a latent image by irradiating a charged photoconductor 2 with a laser.
The rotary developing device 5 includes a yellow developing cartridge 15Y, a cyan developing cartridge 15C, a magenta developing cartridge 15M, which are developing devices of four colors of yellow (Y), cyan (C), magenta (M), and black (K). A black developing cartridge 15K is provided. Each of the developing cartridges 15Y, 15C, 15M, and 15K develops the electrostatic latent image on the photoconductor 2 with toner that is a developer of that color, and forms a toner image of that color on the photoconductor 2. It is a developing device.

  The rotary developing device 5 has a rotary unit 16, and the rotary unit 16 is provided to be able to rotate counterclockwise in the direction opposite to the rotation direction of the photosensitive member 2. As shown in FIGS. 1 and 2, the rotary unit 16 has four mounting frames 16a, 16b, 16c, and 16d on which the developing cartridges 15Y, 15C, 15M, and 15K are detachably mounted and supported. . These mounting frames 16 a, 16 b, 16 c, and 16 d are extended at equal intervals (that is, 90 °) in the rotation direction of the rotary unit 16 and in the axial direction of the rotary unit 16. The mounting frames 16a, 16b, 16c, and 16d are fixed to the rotary shaft 16e of the rotary unit 16 integrally and in a cross-shaped cross shape.

  The developing cartridges 15Y, 15C, 15M, and 15K are moved along the axial direction of the rotary shaft 16e between the corresponding pair of mounting frames among the mounting frames 16a, 16b, 16c, and 16d, respectively. Mounted at the set position. In the example shown in FIG. 1, for example, the yellow developing cartridge 15Y is mounted at a set position between a pair of mounting frames 16a and 16b. The same applies to other developing cartridges.

  The yellow developing cartridge 15Y, the cyan developing cartridge 15C, the magenta developing cartridge 15M, and the black developing cartridge 15K all have basically the same structure. Therefore, the portion related to the present invention in the yellow developing cartridge 15Y will be described, and the description of the developing cartridges 15C, 15M, and 15K of other colors will be omitted.

The yellow developing cartridge 15Y is formed as a cylindrical container that is long in the axial direction and closed at both ends. As shown in FIG. 2, the yellow developing cartridge 15Y includes a yellow developing roller 15Y ₁ that transports yellow toner to the photoreceptor 2, a yellow toner storage portion 15Y ₂ that stores yellow toner, and the yellow toner storage portion 15Y _2. A yellow supply roller 15Y ₃ for supplying the yellow toner to the yellow developing roller 15Y ₁ . Furthermore, although not shown it has a yellow regulating member for regulating the layer thickness of the yellow toner on the yellow development roller 15Y _1.

The yellow rotary shaft developing roller 15Y _1, slightly spaced position from both ends of the yellow developing roller 15Y _1, a pair of rollers 15Y ₄ of the same dimensions is rotatably provided integrally with the yellow development roller 15Y _1. The diameter of these rollers 15Y ₄ is slightly larger than the diameter of the yellow developing roller 15Y ₁ . When the yellow development cartridge 15Y is set at the developing position shown in FIG. 2, by a pair of rollers 15Y ₄ comes into contact with the photosensitive member 2, a predetermined gap between the yellow development roller 15Y ₁ and the photoreceptor 2 Is to be formed. As a result, the yellow developing roller 15Y ₁ performs non-contact development on the electrostatic latent image on the photoreceptor 2.

  Furthermore, as shown in FIG. 2, the rotary unit 16 has a rotary input gear 16f having a relatively large diameter. The apparatus main body 30 is provided with a rotary drive gear 33 that can rotate, and the rotary drive gear 33 meshes with the rotary input gear 16f. Then, power from a motor (not shown) that is a driving means is transmitted to the rotary drive gear 33, so that the rotary drive gear 33 rotates the rotary input gear 16f. As shown in FIG. 3, the rotary unit 16 is positioned at a predetermined position A of the main frame 35 of the apparatus main body and is rotatably attached.

Moreover, the yellow development cartridge 15Y has a development input gear 15Y _5. A developing drive gear 34 is rotatably provided in the apparatus main body 30. The development drive gear 34 meshes with the development input gear 15Y ₅ because the yellow development cartridge 15Y is at the development position shown in FIG. 2, but does not mesh with the development input gear 15Y ₅ at the non-development position of the yellow development cartridge 15Y. ,break away. Further, the developing cartridges 15M, 15C, 15K of colors other than yellow are in the non-developing positions shown in FIG. 2, and the developing drive gears of these developing cartridges 15M, 15C, 15K (not shown: yellow developing cartridge 15Y) Similarly provided with the developing drive gear 34) is spaced from the developing input gear 15Y _5. When one of the developing cartridges 15Y, 15M, 15C, and 15K reaches the developing position, the developing input gear of the developing cartridge is engaged with the developing driving gear 34. Both the development input gear 15Y ₅ and the development drive gear 34 are constituted by bevel gears.

  As shown in FIG. 3, the development drive gear 34 is configured as a gear assembly 37 that is integrated with a gear power transmission mechanism for transmitting the power of the motor 36 that is a drive means to the development drive gear 34. In that case, the mounting position of each gear integrated into the gear assembly 37 is positioned with high accuracy. This gear assembly 37 is also positioned and attached at a predetermined position B of the main frame 35.

Further, a motor 36 is attached to a predetermined position C of the main frame 35. A driving pulley 38 is attached to the rotating shaft of the motor 36 so as to be integrally rotatable. On the other hand, the gear assembly 37 is provided with a driven pulley 39 having a diameter smaller than that of the drive pulley 38, and an endless timing belt 40 is stretched between the drive pulley 38 and the driven pulley 39. The rotation of the motor 36 is decelerated and transmitted to the driven pulley 39 via the drive pulley 38 and the timing belt 40. Further, the rotation of the driven pulley 39 is decelerated and transmitted to the developing drive gear 34 via the gear power transmission mechanism. Thus, the rotation of the motor 36 is transmitted to the development drive gear 34, and the development drive gear 34 is rotated. Then, by the rotation of the development drive gear 34, the yellow developing roller 15Y ₁ and the yellow supply roller 15Y ₃ are rotated via the development input gear 15Y ₅ , respectively.

The primary transfer device 6 transfers the toner image on the photosensitive member 2 to the intermediate transfer member 7 by the primary transfer roller 6a as in the known primary transfer device.
The intermediate transfer body 7 is an intermediate transfer belt made of a conventionally known endless belt. The intermediate transfer belt is stretched between the driving roller 7a and the driven roller 7b, and is rotated and rotated counterclockwise in FIG.

The cleaning device 8 includes, for example, a rubber cleaning blade 8 a disposed between the primary transfer device 6 and the charging device 3 in the same manner as a known cleaning device. The cleaning device 8 removes and collects the residual toner T remaining on the photosensitive member 2 after the primary transfer by the cleaning blade 8a being pressed against the photosensitive member 2.
The paper feed tray 9 accommodates a transfer material 9a such as paper.

The secondary transfer device 10 transfers the toner image on the intermediate transfer body 7 to a transfer material 9a such as paper by a secondary transfer roller 10a as in the known secondary transfer device.
Similarly to the known fixing device, the fixing device 11 also melts the toner image transferred onto the transfer material 9a by the heating roller 11a and the pressure roller 11b and presses the toner image onto the transfer material 9a to form a fixed image.

The paper discharge tray 12 accommodates a transfer material 9a on which a fixed image is formed.
The display device 13 is a known display device configured by, for example, a liquid crystal panel, and displays a display key operated by the user and a setting state of the image forming apparatus 1.
The control device 14 communicates with an external computer to control each device of the image forming apparatus 1 and form an image.

Next, the operation of the image forming apparatus 1 of this example will be described.
When image data and control signals from an external computer are input to the control device 14 of the image forming apparatus 1, the control device 14 drives the image forming apparatus 1. Thereby, the image forming operation of the image forming apparatus 1 is started. At this time, the photosensitive member 2 and the intermediate transfer member 7 are in contact with each other, and the secondary transfer roller 10 a of the secondary transfer device 10 is separated from the intermediate transfer member 7. Furthermore, the rotary unit 16 selectively sets the yellow developing cartridge 15Y to the developing position as shown in FIGS. Accordingly, the pair of rollers 15Y ₄ of the yellow developing cartridge 15Y is in contact with the photoreceptor 2. Further, the rotary driving gear 33 is meshed with the rotary input gear 16f, the developing drive gear 34 meshes with the developing input gear 15Y _5.

  At the start of the image forming operation of the image forming apparatus 1, the photosensitive member 2 is charged by the charging device 3 while rotating. Subsequently, the charged area of the photosensitive member 2 is exposed by the exposure device 4 to form a first color, for example, an electrostatic latent image of yellow Y in the example shown in FIG. Subsequently, the yellow (Y) electrostatic latent image formed on the photosensitive member 2 is developed with the yellow toner of the yellow developing cartridge 15Y. As a result, a yellow (Y) toner image is formed on the photoreceptor 2.

  The yellow (Y) toner image formed on the photosensitive member 2 is transferred to the intermediate transfer member 7 by the primary transfer device 6. After the primary transfer of the yellow (Y) toner image, the yellow toner remaining on the photosensitive member 2 is removed from the photosensitive member 2 and collected by the cleaning blade 8a of the cleaning device 8. During this time, the yellow (Y) toner image on the intermediate transfer member 7 moves as the intermediate transfer member 7 rotates.

Subsequently, the rotary unit 16 is rotated 90 ° counterclockwise by the power of a motor (not shown) which is a driving means, and the black developing cartridge 15K is selectively set to the developing position. As a result, the developing input gear of the black developing cartridge 15K meshes with the developing drive gear 34. Further, the developing roller 15K ₁ of the black developing cartridge 15K is brought into contact with the photosensitive member 2. Further, after the photosensitive member 2 is charged again by the charging device 3, the charged region of the photosensitive member 2 is exposed by the exposure device 4, and an electrostatic latent image of the second color, for example, black Y in the example shown in FIG. It is formed. Subsequently, the electrostatic latent image of black (K) formed on the photosensitive member 2 is developed with the black toner of the black developing cartridge 15K. As a result, a black (K) toner image is formed on the photoreceptor 2.

  The black (K) toner image formed on the photosensitive member 2 is transferred to the intermediate transfer member 7 by the primary transfer device 6. At this time, the black (K) toner image is transferred in a color superimposed manner on the yellow (Y) toner image on the intermediate transfer body 7 that has been rotated once. After the primary transfer of the black (K) toner image, the black toner remaining on the photosensitive member 2 is removed from the photosensitive member 2 and collected by the cleaning blade 8a of the cleaning device 8. During this time, the yellow (Y) and black (K) toner images on the intermediate transfer member 7 move as the intermediate transfer member 7 rotates.

  Thereafter, in the same manner, for the third color, for example, magenta (M) in the example shown in FIG. 1, and the fourth color, for example, cyan (C) in the example shown in FIG. , And primary transfer is performed. Thus, on the intermediate transfer body 7, four colors of yellow (Y), black (K), magenta (M), and cyan (C) are overlaid to form a full-color toner image. Note that magenta toner and cyan toner remaining on the photosensitive member 2 after the primary transfer are similarly removed and collected from the photosensitive member 2 by the cleaning blade 8a of the cleaning device 8.

  The full color toner image formed on the intermediate transfer body 7 is secondarily transferred to the transfer material 9 a by the secondary transfer roller 10 a of the secondary transfer device 10. The transfer material 9 a is picked up and conveyed one by one from the paper feed tray 9 by the paper feed roller 17, and the timing is adjusted by the registration roller 18 and conveyed to the secondary transfer device 10. Further, the full color toner image transferred to the transfer material 9a is heated and pressed by the heating and pressure rollers 11a and 11b of the fixing device 11 and fixed to the transfer material 9a. The transfer material 9 a on which the full-color toner image is fixed is accommodated in the paper discharge tray 12 via the paper discharge roller 19. In this way, a full color image forming operation is performed by the image forming apparatus 1 of this example.

  Note that the image forming apparatus 1 of this example can perform not only a full-color image forming operation as described above but also a single-color image forming operation. As an example, a black (K) monochrome image, that is, a monochrome image forming operation will be described.

  In the monochrome image forming operation, the black developing cartridge 15 </ b> K of the rotary developing device 5 is set at the developing position facing the photoreceptor 2. In the same manner as in the above-described full color image forming operation, charging, exposure, and black (K) development are performed on the photoconductor 2 to form a black toner image on the photoconductor 2. The black toner image on the photoreceptor 2 is primarily transferred to the intermediate transfer member 7 by the primary transfer device 6, and the black toner image on the intermediate transfer member 7 is secondarily transferred to the transfer material 9 a by the secondary transfer device 10. Is done. After the primary transfer, the black toner (K) remaining on the photoconductor 2 is removed from the photoconductor 2 by the cleaning device 8 and collected.

  The black toner image transferred to the transfer material 9a is fixed by the fixing device 11. The transfer material 9 a on which the black toner image is fixed is accommodated in the paper discharge tray 12. In this way, a monochrome image is formed.

  By the way, when one of the developing cartridges 15Y, 15M, 15C, and 15K reaches the developing position, the developing input gear of the developing cartridge needs to be surely engaged with the developing driving gear 34. For this purpose, the relative position between the development input gear at the development position and the development drive gear 34 must be set more accurately. Therefore, the developing drive gear 34 needs to be positioned and attached to the main frame 35 with high accuracy with respect to the center position D of the rotary shaft of the rotary unit 16 set on the main frame 35.

  Therefore, in the present invention, in order to position the developing drive gear 34 of the gear assembly 37 with high accuracy, a positioning jig is used as in the prior art. This positioning jig 41 can be a known one. 4A and 4B show an example of a positioning jig. As shown in FIG. 4A, the positioning jig 41 of this example includes a support portion 35a that is supported in contact with the main frame 35, and a development drive shaft 34a of the development drive gear 34 (shown in FIG. 3). Are formed in a U-shape in a side view from a positioning portion 35b and a connecting portion 35c for connecting the supporting portion 35a and the positioning portion 35b.

  On the lower surface of the support portion 35a, a pair of columnar reference protrusions 42 and 43 are provided projecting downward. The positioning portion 35b is provided with a positioning hole 44 for the development drive shaft 34a. As shown in FIG. 4B, the diameter a (the length of the straight portion in the direction orthogonal to the longitudinal direction of the reference protrusion 43) of both reference protrusions 42 and 43 is set with high accuracy.

  The positioning portion 35b is provided with a circular development drive shaft positioning hole 44 that is positioned by fitting the development drive shaft 34a. As shown in FIG. 4B, the distance c between the center of the reference protrusion 42 and the center of the development drive shaft positioning hole 44 along the straight line b connecting the centers of both reference protrusions 42 and 43, and A distance d between the center of the reference protrusion 42 and the center of the development drive shaft positioning hole 44 in a direction orthogonal to the straight line b is set with high accuracy. As a result, the development drive shaft 34a is positioned with high accuracy with respect to the reference protrusion 42.

  On the other hand, as shown in FIGS. 3 and 5, a circular reference hole 45 having the same diameter as the reference protrusion 42 is provided in the main frame 35 so as to correspond to the reference protrusion 42. The main frame 35 is provided with an oval reference hole 46 having a width equal to the diameter a of the reference protrusion 43 so as to correspond to the reference protrusion 43.

  As shown in FIG. 4B, the positioning jig 41 has its reference projections 42 and 43 fitted in the reference holes 45 and 46 of the main frame 35, respectively, and is indicated by a two-dot chain line in FIG. In addition, the entire surface of the support portion 35a is set in contact with the main frame 35. In this state, in the positioning jig 41, the reference protrusion 42 is positioned by the reference hole 45 and the reference protrusion 43 is positioned by the reference hole 46 in the width direction of the reference hole 46. Therefore, the positioning jig 41 is positioned and set on the main frame 35 with high accuracy. At this time, the center position of the development drive shaft positioning hole 44 of the positioning jig 41 is a position where the development input gear of the development cartridge set at the development position meshes more reliably and more accurately with the development drive gear 34. It has become.

  As shown in FIGS. 5 and 6, a position memory member 47 is attached to a side of the main frame 35 opposite to the gear assembly 37 attachment side by a predetermined number (three in this example) of screws 48. The position memory member 47 can also be attached to the main frame 35 by other fixing means other than the screws 48, such as welding.

  As shown in FIG. 7, the position memory member 47 is formed in a flat plate shape, and has a pair of position memory holes 49 and 50 and two attachment holes 51 and 52. One position memory hole 49 is formed in a circular shape, and one end portion 53b of the rotation shaft 53a of the intermediate gear 53 of the gear power transmission mechanism meshing with the developing drive gear 34 is fitted without a gap. One of the screws 48 is screwed into the female screw of the rotating shaft 53 a, and the position memory member 47 is attached to the main frame 35. In that case, the tip of the one end 53 b of the rotating shaft 53 a is in a position slightly retracted from the surface of the position memory member 47. Therefore, when the screw 48 is screwed to the rotating shaft 53 a, the position memory member 47 is sandwiched between the main frame 35 and the screw head of the screw 48.

  The other position memory hole 50 is formed in an oval shape. The width e of the position memory hole 50 is such that one end portion 54b of the rotation shaft 54a of the other intermediate gear 54 of the gear power transmission mechanism meshing with the intermediate gear 53 is fitted in the width direction of the position memory hole 50 without a gap. The size is set.

  Therefore, the rotation shaft 53a is positioned in both the vertical direction and the horizontal direction with respect to the main frame 35 in FIG. 5 by fitting the one end portion 53b of the rotation shaft 53a with the position memory hole 49. Further, the one end portion 54b of the rotating shaft 54a and the position memory hole 50 are fitted to each other so that the main frame 35 is positioned in the rotation direction around the one end portion 53b of the rotating shaft 53a. Thus, the gear assembly 37 is positioned and attached to the frame assembly 35, and the developing drive shaft 34a is positioned at a predetermined position with high accuracy. In that case, since the position memory hole 50 is formed in an oblong hole, it is possible to absorb the tolerance caused by the assembly tolerance of the gear assembly 37 and the machining error of each gear.

Next, attachment of the gear assembly 37 and the position memory member 47 of the image forming apparatus 1 of this example configured as described above will be described.
First, in the initial assembly of the image forming apparatus 1, the position memory member 47 is not attached to the main frame 35 as shown in FIG. The gear assembly 37 is temporarily fixed to the main frame 35 by screwing a predetermined number of screws 55. In this state, as shown by a two-dot chain line in FIG. 3, the positioning jig 41 is positioned and set on the main frame 35 as described above. Then, after the developing drive shaft 34 a is fitted in the positioning hole 44 of the positioning jig 41, the gear assembly 37 is attached to the main frame 35 by further completely screwing a predetermined number of screws 55. Thereafter, the positioning jig 41 is removed from the main frame 35. Thus, as shown in FIG. 8A, the gear assembly 37 is attached to the main frame 35 with the development drive shaft 34a positioned at a predetermined position with high accuracy.

  Next, the position memory member 47 is applied to the surface of the main frame 35 opposite to the mounting surface of the gear assembly 37. At this time, the position memory hole 49 is fitted to the one end portion 53b of the rotating shaft 53a, and the position memory hole 50 is fitted to the one end portion 54b of the rotating shaft 54a. Thereby, the position of the position memory member 47 with respect to the main frame 35 is determined. In this state, the position memory member 47 is fixed to the main frame 35 by the screw 48. Thus, in the state where the position memory member 47 is positioned and fixed to the main frame 35, the position of the position memory hole 49 of the position memory member 47 is the center position of the rotating shaft 53a, and the position memory hole 50. Is the center position of the rotating shaft 54a.

  Accordingly, the center positions of the rotating shafts 53a and 54a of the gear assembly 37 are stored in the position memory holes 49 and 50 of the position memory member 47. Since the center position of the development drive shaft 34a is positioned with high accuracy with respect to the rotation shafts 53a and 54a by the gear assembly 37, the center positions of these rotation shafts 53a and 54a are stored in memory, thereby developing drive. The center position of the shaft 34a is also stored. In that case, the center position of each shaft 53a, 54a memorized by the position memory member 47 is a position that takes into account the assembly tolerance of each part that is unique to the device, and therefore is a position memorized with higher accuracy. ing.

  It may be necessary to remove the gear assembly 37 from the main frame 35 due to a failure or degeneration of the drive system such as the gear assembly 37 or the timing belt 40. In this case, when the gear assembly 37 is removed from the main frame 35, the position memory member 47 remains attached to the main frame 35 as shown in FIG.

  The gear assembly 37 or other replacement part is replaced with a new one and assembled to the frame 35. The gear assembly 37 is also assembled to the frame 35. At this time, conventionally, the center position of the developing drive shaft 34a is positioned by using the positioning jig 41 described above so that the developing drive shaft 34a is highly accurate. The gear assembly 37 is assembled to the main frame 35 in the positioned state. However, using the positioning jig 41 in this way requires a lot of labor and time.

  On the other hand, in the rotary developing device 5 of this example, the position memory member 47 is attached to the main frame 35, and the position memory member 47 accurately memorizes the center positions of the rotating shafts 53a and 54a of the gear assembly 37. ing. Accordingly, when the gear assembly 37 is assembled to the frame 35, the two rotation shafts 53a and 54a of the gear assembly 37 are fitted into the position memory holes 49 and 50 of the position memory member 47 as shown in FIG. As a result, the positions of the rotary shafts 53a and 54a of the gear assembly 37 can be determined very easily and with high accuracy. That is, the development drive shaft 34a is positioned very easily and with high accuracy. In this manner, the gear assembly 37 is assembled to the main frame 35 with the screws 55 in a state where the rotary shafts 53a and 54a are fitted in the position memory holes 49 and 50 of the position memory member 47, respectively. Thus, the developing drive shaft 34a is positioned with high accuracy, and the gear assembly 37 is easily assembled to the main frame 35.

  According to the rotary developing device 5 of this example, the positions of the rotary shafts 53a and 54a positioned with high accuracy are stored in the position memory holes 49 and 50 of the position memory member 47 assembled to the main frame 35, respectively. . When the gear assembly 37 formed by positioning the rotary shafts 53a and 54a with high accuracy with respect to the position of the developing drive shaft 34a is assembled to the main frame 35, the rotary shafts 53a and 54a are respectively connected to the position memory member 47. The both position memory holes 49 and 50 are simply fitted. As a result, the development drive shaft 34a is positioned very easily and with high accuracy, and the state where the development drive shaft 34a is positioned in this way is maintained, and the gear assembly 37 is placed in the main frame 35 with great effort and time. It can be easily assembled without any need.

  By the way, the gear assembly 37 is removed from the main frame 35 when the gear assembly 37 is replaced or when a timing belt 40 other than the gear assembly 37 is replaced. When the new gear assembly 37 is assembled to the main frame 35 or the previously removed gear assembly 37 is assembled to the main frame 35 again, the gear assembly 37 can be moved to the position memory member without requiring a special positioning jig. 47, it can be positioned very easily and with high accuracy and assembled to the main frame 35. As a result, the inter-axis accuracy between the rotation shaft of each development input gear 15 and the rotation shaft 34a of the development drive gear 34 can be ensured easily and with high accuracy.

In this case, since the position memory member 47 stores the mounting positions of the rotation shafts 53a and 54a of the gear assembly 37 that is positioned and mounted with high accuracy, the drive shaft 34a of the developing drive gear 34 of the gear assembly 37 is assembled. It is possible to eliminate the accumulated tolerance such as and maintain the position with high accuracy and to assemble the main frame 35. Moreover, since only the parts that need to be exchanged are exchanged, the parts can be exchanged easily and inexpensively.
Further, according to the image forming apparatus 1 provided with the positioning device of this example, the parts for the developing device other than the gear assembly 37 such as the gear assembly 37 or the timing gear can be replaced easily and with high accuracy. An image with an image quality can be obtained.

  In the above-described example, the rotation shafts 53a and 54a of the gear assembly 37 are positioned with respect to the main frame 35 with high precision by the position memory holes 49 and 50 of the position memory member 47, respectively, so that the developing drive shaft of the gear assembly 37 is obtained. 34a is positioned with respect to the main frame 35 with high accuracy. However, the present invention is not limited to this, and the position drive member 34 a of the gear assembly 37 can be directly and accurately positioned with respect to the main frame 35 by the position memory member 47.

  In the above-described example, the position memory member 47 stores the position of the development drive shaft 34a positioned with high accuracy by the positioning method using the positioning jig 41. However, the present invention is highly effective in other positioning methods. The position of the developing drive shaft 34a positioned with high accuracy can be stored in the position memory member 47.

1 is a diagram schematically illustrating an example of an image forming apparatus including an example of an embodiment of a rotary developing device according to the present invention. FIG. 2 is a diagram schematically and enlargedly showing a rotary developing device and a photoconductor shown in FIG. 1. It is a front view which shows the positional relationship of the rotary unit integrated in a main frame, and a gear assembly. (A) is a perspective view which shows an example of the positioning jig for positioning a developing drive shaft with respect to a main frame, (b) is a figure which shows the positional relationship of the jig | tool hole of this jig | tool. It is a reverse view which shows the positional relationship of the rotary unit shown in FIG. 3, and a gear assembly. It is sectional drawing which shows the state which assembled | attached the gear assembly to the main frame. It is a figure which shows a position memory member. (A) is sectional drawing explaining positioning of a gear assembly to a main frame with the positioning jig, (b) is sectional drawing which shows the state of the main frame which removed the gear assembly.

Explanation of symbols

1 ... image-forming apparatus, 2 ... photoreceptor, 5 ... rotary developing device, 15Y, 15C, 15M, 15K ... each color developing cartridge, 15Y ₁ ... yellow developing roller, 15Y ₅ ... development input gear, 16 ... rotary unit, 34 Development drive gear, 35 ... main frame, 37 ... gear assembly, 41 ... positioning jig, 47 ... position memory member, 49, 50 ... position memory hole, 53, 54 ... intermediate gear, 53a, 54a ... rotating shaft

Claims (5)

A first part of the image forming apparatus removably attached to the main frame of the apparatus main body; a second part of the image forming apparatus removably attached to the main frame and positioned relative to the first part;
A position memory member that is attached to the main frame and stores a mounting position of the second component that is positioned and attached to the main frame;
An apparatus for positioning parts in an image forming apparatus, comprising: 2. The developing device according to claim 1, wherein the first component is a developing input gear of a developing device, and the second component is a developing driving gear that meshes with the developing input gear and transmits power from a driving unit. Positioning apparatus for an image forming apparatus. The device body;
An image carrier provided in the apparatus body and carrying an electrostatic latent image and a toner image,
A rotary developing device provided in the apparatus main body and developing the electrostatic latent image on the image carrier to form a toner image;
The rotary developing device includes at least a rotary unit in which a plurality of developing cartridges are mounted and selectively moves between a developing position and a non-developing position.
Each of the developing cartridges is provided with a developing input gear for driving the developing roller, and meshed with the developing input gear at the developing position of the developing cartridge on the main frame of the apparatus main body and from the driving means. A development drive gear to which power is transmitted is provided,
The image forming apparatus according to claim 2, further comprising a position memory member that stores a mounting position of the developing drive gear that is positioned and attached to the main frame. The second part of the image forming apparatus is detachably attached to the main frame and positioned relative to the mounting position of the first part with respect to the mounting position of the first part of the image forming apparatus that is detachably attached to the main frame. And then mounting a position memory member for storing the mounting position of the second component on the main frame. 5. The developing component according to claim 4, wherein the first component is a developing input gear of a developing device, and the second component is a developing driving gear that meshes with the developing input gear and transmits power from a driving unit. Part positioning method in the image forming apparatus.

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