JP2009271150A - Inter-roller distance adjustment method, development gap adjustment method, roller device, imaging device, process cartridge, image forming apparatus, and long member device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inter-roller distance adjustment method, in which an inter-roller distance, which is a distance between two roller members, is adjusted without displacing the rotation shafts of the two target rollers, for the inter-roller distance, with respect to support face plates. <P>SOLUTION: An imaging unit 200 includes: a photoreceptor 1; the front and rear face plates 210 and 220 serving as the first and second support face plates respectively for supporting both end of a developing roller 41 and both ends of each of the two roller members; and a plate-like stay 230. The length of a first span S1 is changed by altering the number of attached shims 231 which are spacer members between the plate-like stay 230 and front plate 210. A development gap GP is adjusted by changing the inclination of the rear face plate 220 relative to the front face plate 210. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for adjusting a distance between rollers of a roller device including a plurality of roller members, a method for adjusting a development gap of an image forming device included in an image forming apparatus, a roller device including a plurality of roller members, and a roller device capable of adjusting a development gap. The present invention relates to an image forming apparatus, a process cartridge including the image forming apparatus, and an image forming apparatus. The present invention also relates to a longitudinal member device including a plurality of longitudinal members.

In an image forming apparatus aiming at high productivity, it is necessary to secure developing capability corresponding to a high process linear velocity. In such an image forming apparatus, it is necessary to rotate the photosensitive member and the developing roller at a high speed in order to cope with a high process linear velocity. However, rotating at a high speed means a rubbing part such as a bearing or a motor as a driving source. The burden on is increased. For this reason, there is a configuration using a photoconductor and a developing roller having a large diameter in order to cope with a high process linear velocity while suppressing the rotation speed of the photoconductor and the developing roller. When the photosensitive member or the developing roller has a large diameter, it is difficult to suppress the variation in the roller diameter during processing as compared with the small-diameter roller. Even in the configuration in which the diameters of the photosensitive member and the developing roller are increased, the development gap, which is the gap between the photosensitive member and the developing roller, tends to be narrowed in order to achieve high image quality.
Under such circumstances, it is difficult to ensure development gap accuracy by component accuracy in a high-speed and large-sized image forming apparatus having a particularly complicated configuration. For this reason, it becomes necessary to add a mechanism for adjusting the development gap.
As an image forming apparatus provided with a mechanism for adjusting the development gap, there is an apparatus described in Japanese Patent Application Laid-Open No. H10-228707. In the image forming apparatus described in Patent Document 1, the position of the rotation shaft of the developing roller is adjusted at a roller position that is a rotation shaft support member that has a rotation center different from that of the developing roller and is rotatable with respect to the developing device. The holder supports it. Then, by adjusting the rotation of the roller position adjustment holder, the position of the rotation shaft of the developing roller with respect to the developing device is adjusted, and the developing roller is moved closer to or away from the photosensitive member whose position is fixed with respect to the developing device. can do. As a result, the development gap can be adjusted by widening or narrowing the gap of the development gap.

Japanese Patent Laid-Open No. 11-038722

However, a mechanism for adjusting the developing gap described in Patent Document 1 in a configuration having two supporting face plates for supporting both ends of the photosensitive member, and fixing the developing device to the supporting face plates to constitute an image forming device. In addition to the supporting face plate, a rotating shaft supporting member that supports the rotating shaft of the developing roller and is movable with respect to the photosensitive member is required. As described above, if the adjustment mechanism is provided with a rotating shaft support member separately from the support face plate, there is a restriction on the addition of the adjustment mechanism in the layout due to the influence of the development drive components that are often arranged on the back side of the apparatus. This leads to an increase in the size of the device. In addition, the rotation shaft on the side that transmits driving to the developing roller needs to be configured to be rotatable with respect to the support member, and the support member is supported via a bearing member. If the support member that supports the rotating shaft via the bearing member is provided separately from the support face plate and is configured to be movable with respect to the support face plate, the entire support member is supported, which further increases the size of the apparatus. .
In the above description, the support member that supports the rotating shaft of the developing roller is provided separately from the support face plate, and the problem of the structure that can move is described. However, the member that supports the rotating shaft of the photosensitive member can be moved. The same problem arises even in the configuration.
In the above description, the image forming apparatus including the photoconductor and the developing roller that are arranged close to each other so as to have a predetermined developing gap has been described. However, such a problem is not limited to the image forming apparatus, and includes a plurality of roller members, and two roller members among the plurality of roller members have a predetermined distance between the rollers (between the rotation centers of the two roller members). The same problem arises if the roller device is arranged so that Examples of the combination of the two roller members of the roller device include, but are not limited to, a photoreceptor and a charging roller, a conveying roller pair, and a roller pair forming a fixing nip of the fixing device.
Further, such a problem is not limited to a roller device including a plurality of roller members, and includes a plurality of longitudinal members arranged in parallel to the longitudinal direction, and two of the plurality of longitudinal members are predetermined. The same problem arises if the longitudinal member device is arranged so as to have a distance between the members. Examples of the combination of the two longitudinal members of the longitudinal member device include a toner image carrier and a cleaning blade, a developing roller and a doctor blade, but are not limited thereto.

The present invention has been made in view of the above problems, and a first object of the present invention is to displace two rotation members of a roller surface as a target of the distance between the rollers with respect to the support face plate without displacing the rotation shafts. An object of the present invention is to provide a method for adjusting a distance between rollers, which can adjust a distance between rollers of a roller member.
The second purpose is to adjust the distance between the rollers of the two roller members without displacing the position of the rotation shafts of the two roller members that are targets of the distance between the rollers with respect to the support face plate. An image forming apparatus as a roller apparatus, an image forming apparatus as a roller apparatus, a process cartridge including the image forming apparatus, and an image forming apparatus.
Another object of the present invention is to adjust the distance between the members of the two longitudinal members without displacing the fixing position of the two longitudinal members that are the target of the distance between the members with respect to the support surface plate. It is providing the longitudinal member apparatus which can do.

In order to achieve the above object, the invention of claim 1 includes a plurality of roller members arranged so that rotation axes thereof are parallel to each other, a first support face plate that supports axial ends of the plurality of roller members, The plurality of roller members of the roller device having a second support surface plate disposed opposite to the first support surface plate with the plurality of roller members interposed therebetween and supporting the other axial end of the plurality of roller members. In the inter-roller distance adjustment method for adjusting the inter-roller distance, which is the distance between the rotation centers of the two roller members, the inter-roller distance is reduced by changing the inclination of the second support face plate with respect to the first support face plate. It is characterized by adjusting.
The invention according to claim 2 is the roller distance adjusting method according to claim 1, wherein both ends in the axial direction are fixed to the first support face plate and the second support face plate, respectively. A plurality of stay members for determining a distance between the first support face plate and the second support face plate in the axial direction, and the stay members at a position where some of the stay members are fixed. The inclination of the second support face plate with respect to the first support face plate is changed by changing the distance between the first support face plate and the second support face plate.
According to a third aspect of the present invention, in the roller distance adjusting method according to the second aspect of the present invention, the roller device is fixed at a position fixed to the first support surface plate and the second support surface plate as the plurality of stay members. A stay member, and a stay member capable of adjusting the distance between the support surface plates, the distance between the first support surface plate and the second support surface plate at a fixed position being adjustable, and the first support surface plate and the first support member. By changing the number of spacer members that can be attached and detached between at least one of the two support face plates and the stay member that can adjust the distance between the support face plates, the stay member at the position where the stay member that can adjust the distance between the support face plates is fixed. The distance between the first support face plate and the second support face plate is changed.
According to a fourth aspect of the present invention, in the roller distance adjusting method according to the second aspect of the present invention, the roller device is fixed at positions relative to the first support surface plate and the second support surface plate as the plurality of stay members. A stay member, and a stay member capable of adjusting the distance between the support surface plates at a fixed position from the first support surface plate to the second support surface plate, the length of the stay member capable of adjusting the distance between the support surface plates. By adjusting the height, the distance between the first support face plate and the second support face plate at a position where the stay member capable of adjusting the distance between the support face plates is fixed is changed.
According to a fifth aspect of the present invention, there is provided a photosensitive member and a developing device including a developing roller that forms a developing gap between the surface and the surface of the photosensitive member and develops a latent image on the photosensitive member. 5. The developing gap adjusting method for adjusting the developing gap of an image forming device, wherein the image forming device is a roller device including the photosensitive member and the developing roller as the two roller members. The development gap is adjusted by any of the roller distance adjustment methods described in any one of the above.
According to a sixth aspect of the present invention, there are provided a plurality of roller members arranged so that rotation axes thereof are parallel to each other, a first support face plate that supports one axial end of the plurality of roller members, and the plurality of roller members. A roller device having a second support surface plate disposed opposite to the first support surface plate and supporting the other axial end of the plurality of roller members, the second support surface plate with respect to the first support surface plate 2 of the plurality of roller members by changing the inclination of the second support face plate with respect to the first support face plate by the support face plate inclination adjusting means. The distance between the rollers, which is the distance between the rotation centers of the two roller members, is adjusted.
According to a seventh aspect of the present invention, in the roller device of the sixth aspect, the axial direction of the rotating shaft extends in the axial direction, and both end portions in the axial direction are fixed to the first supporting face plate and the second supporting face plate, respectively. A plurality of stay members for determining a distance between the first support face plate and the second support face plate in the axial direction of the rotation shaft, and the support face plate inclination adjusting means is configured as one of the plurality of stay members. Support surface plate distance adjusting means for adjusting the distance between the first support surface plate and the second support surface plate at a position where a part of the stay members are fixed is provided. The inclination of the second support face plate relative to the first support face plate is adjusted by changing the distance between the first support face plate and the second support face plate at a position where the member is fixed. is there.
According to an eighth aspect of the present invention, in the roller device of the seventh aspect, as the plurality of stay members, a fixed stay member in which positions relative to the first support face plate and the second support face plate are fixed, and a fixed position. A support member that can adjust the distance from the first support surface plate to the second support surface plate so that the distance between the support surface plates can be adjusted.
According to a ninth aspect of the present invention, in the roller device of the eighth aspect, the fixed stay member and the stay member capable of adjusting the distance between the support face plates are made of a material having substantially the same thermal expansion coefficient. It is.
According to a tenth aspect of the present invention, in the roller device according to the eighth or ninth aspect, the distance adjustment means between the support face plates and at least one of the first support face plate and the second support face plate as the distance adjustment means between the support face plates. The spacer member is configured to be detachable between the support member and the number of the spacer members mounted is changed to change the distance between the support member plates. The distance between the second support face plate can be changed.
The invention according to claim 11 is the roller device according to claim 8 or 9, wherein the length of the support face plate distance adjustable stay member is adjustable as the support face plate distance adjusting means, and the support face plate is adjustable. The distance between the first support face plate and the second support face plate at a position where the stay member between which the distance between the support face plates is adjustable is fixed can be changed by adjusting the length of the stay distance adjustable stay member. It is characterized by that.
According to a twelfth aspect of the present invention, in the roller device of the eighth, ninth, tenth or eleventh aspect, the inclination of the second support face plate relative to the first support face plate is adjusted between the support face plates of the second support face plate. This is done by displacing the position where the distance adjustable stay member is fixed relative to the first support face plate, and the second support face plate and the support face plate distance adjustable stay member are screwed with a plurality of screws. Accordingly, the second support face plate is formed in a peninsula shape at a position where the stay member capable of adjusting the distance between the support face plates is fixed.
According to a thirteenth aspect of the present invention, in the roller device of the eighth, ninth, tenth, eleventh or twelfth aspect, the adjustment of the inclination of the second support face plate with respect to the first support face plate is performed by the support of the second support face plate. This is done by displacing the position where the stay member capable of adjusting the distance between the face plates is fixed with respect to the first support face plate, and the second support face plate and the stay member capable of adjusting the distance between the support face plates are screwed by a plurality of screws. Fixing is achieved by stopping, and among the plurality of screwing positions, the screwing position close to the fixing stay is the center of rotation of the two roller members that are targets of the distance between the rollers on the second support face plate. It arrange | positions so that it may be located on the straight line which connects (2) or in the vicinity of this straight line.
The invention according to claim 14 is the roller device according to claim 6, 7, 8, 9, 10, 11, 12 or 13, wherein one of the two roller members to be subjected to the distance between the rollers is the one of the roller members. Of the two bearing parts that support both ends, at least one of the bearing parts is arranged such that the position in the axial direction is offset with respect to the first support face plate or the second support face plate on which the bearing part is placed. It is characterized by being.
According to a fifteenth aspect of the present invention, there is provided a developing device comprising a photosensitive member, a developing roller having a developing gap formed between the surface of the photosensitive member and the surface of the photosensitive member, and developing a latent image on the photosensitive member; A first support surface plate supporting one end of the rotating shaft of the photosensitive member in the axial direction and one end of the rotating shaft of the developing roller in the axial direction, and facing the first supporting surface plate with the photosensitive member and the developing roller interposed therebetween. The image forming apparatus includes a second support face plate that is disposed on the second support surface plate and supports the other end in the axial direction of the rotation shaft of the photosensitive member and the other end in the axial direction of the rotation shaft of the developing roller. The roller device according to claim 6, 7, 8, 9, 10, 11, 12 or 13, comprising the photosensitive member and the developing roller as the two roller members.
The invention according to claim 16 is the imaging device according to claim 15, wherein both ends of the rotating shaft extend in the axial direction of the rotating shaft, and the first supporting face plate and the second supporting face plate respectively. A plurality of stay members fixed to determine the distance between the first support face plate and the second support face plate in the axial direction of the rotation shaft, and as the support face plate inclination adjusting means, among the plurality of stay members A support surface plate distance adjusting means for adjusting a distance between the first support surface plate and the second support surface plate at a position where a portion of the stay members are fixed, The inclination of the second support face plate with respect to the first support face plate is adjusted by changing a distance between the first support face plate and the second support face plate at a position where a stay member is fixed. It is.
Further, the invention of claim 17 is the imaging device of claim 16, wherein the plurality of stay members are fixed to a fixed stay member whose positions relative to the first support face plate and the second support face plate are fixed. And a support member that can adjust the distance between the first support face plate and the second support face plate in a position that can be adjusted.
According to an eighteenth aspect of the present invention, in the image forming apparatus according to the seventeenth aspect of the invention, the adjustment of the inclination of the second support face plate with respect to the first support face plate is a stay member capable of adjusting the distance between the support face plates of the second support face plate. The second support surface plate and the support member whose distance between the support surface plates can be adjusted are fixed by screwing with a plurality of screws. The developing device has two developing rollers, and among the screwing positions, the screwing position close to the fixed stay is the midpoint of the rotation center of the two developing rollers on the second support face plate. It is arranged to be located on or near the straight line connecting the rotation center of the photosensitive member.
According to a nineteenth aspect of the present invention, in the image forming apparatus according to the seventeenth or eighteenth aspect, the adjustment of the inclination of the second support face plate with respect to the first support face plate can adjust the distance between the support face plates of the second support face plate. It is performed by displacing the position where the stay member is fixed with respect to the first support face plate, and includes a plurality of the support face plate distance adjustable stay members, and the plurality of support face plate distance adjustable stay members are fixed. The distance from the first support face plate to the second support face plate at a predetermined position can be adjusted independently of each other, and the developing device has two developing rollers, and a plurality of support distance plate adjustable stays. The fixing position of the member with respect to the second support face plate is on or near a straight line orthogonal to a straight line connecting the midpoint of the rotation centers of the two developing rollers and the rotation center of the photosensitive member. And it is characterized in that it is arranged to be positioned.
According to a twentieth aspect of the present invention, in the imaging device of the seventeenth, eighteenth, or nineteenth aspect, the adjustment of the inclination of the second support face plate relative to the first support face plate is performed by adjusting the distance between the support face plates of the second support face plate. This is performed by displacing the position where the adjustable stay member is fixed with respect to the first support face plate, and the first support face plate is provided with a fixing portion for fixing the image forming apparatus on which the image forming apparatus is arranged. The fixing portion and the first supporting face plate are arranged so that the position where the stay member for adjusting the distance between the supporting face plates is fixed is separated from the first supporting face plate.
The invention according to claim 21 is the image forming device according to claim 20, wherein there are a plurality of fixing portions of the first support face plate relative to the image forming apparatus, and the first supporting surface plate in the vicinity of at least one of the fixing portions. It is characterized in that the bending strength of one supporting face plate is reduced.
The invention according to claim 22 is the imaging apparatus according to claim 17, 18, 19, 20 or 21, wherein the first support face plate and the second support face plate are provided with a fixed portion of the fixed stay member and the support. The positioning mechanism of the photoconductor with respect to the first support surface plate and the second support surface plate is disposed between the fixed portions of the stay members capable of adjusting the distance between the face plates.
According to a twenty-third aspect of the present invention, in the imaging device of the seventeenth, eighteenth, nineteenth, twenty-first, twenty-first or twenty-second aspect, the developing device is fixed to the first support face plate and the second support face plate. The developing device 4 also functions as the fixed stay member.
According to a twenty-fourth aspect of the present invention, there is provided the image forming apparatus according to the fifteenth, sixteenth, seventeenth, eighteenth, nineteenth, twenty-first, twenty-first, twenty-second, twenty-third, or twenty-third image forming apparatus. The photoconductor positioning mechanism for positioning the photoconductor includes a photoconductor bearing member that is a rotation support member that rotatably supports the photoconductor relative to the first support surface plate and the second support surface plate. At least one of the bearing members is an arrangement in which the position in the axial direction of the rotary shaft is offset with respect to the first support face plate or the second support face plate on which the photosensitive member bearing member is disposed. To do.
According to a twenty-fifth aspect of the present invention, in the imaging apparatus of the twenty-fourth aspect, when the inclination of the second support face plate with respect to the first support face plate is changed, The photosensitive member bearing member disposed on the supporting face plate and the photosensitive member bearing member disposed on the second supporting face plate have different configurations.
According to a twenty-sixth aspect of the present invention, in the image forming apparatus of the twenty-fifth aspect, the photosensitive member bearing member disposed on the first supporting face plate and the photosensitive member bearing member disposed on the second supporting face plate. The offset amount with respect to the support face plate on which the photosensitive member bearing member is arranged is different.
According to a twenty-seventh aspect of the present invention, in the image forming apparatus according to the twenty-fifth or twenty-sixth aspect, on the straight line connecting the rotation center of the developing roller and the rotation center of the photoconductor on the first support surface plate and the second support surface plate. The bending strength with respect to the direction is different between the first support face plate and the second support face plate.
According to a twenty-eighth aspect of the present invention, in the image forming device according to the twenty-fifth, twenty-sixth or twenty-seventh aspect, a displacement amount of the photosensitive member bearing member when an inclination of the second supporting face plate with respect to the first supporting face plate is changed. A developing roller position adjusting mechanism for adjusting a position of the supporting surface plate that supports the rotating shaft of the developing roller on the supporting surface plate is provided on the small supporting surface plate.
According to a twenty-ninth aspect of the present invention, in the image forming apparatus according to the thirty-third aspect, the developing device has a plurality of developing rollers, and the developing roller position adjusting mechanism independent of each of the plurality of developing rollers. It is characterized by this.
The invention according to claim 30 is the image bearing device according to claim 25, 26, 27, 28 or 29, wherein the inclination of the second support face plate relative to the first support face plate is changed. A developing roller driving mechanism for transmitting the driving force to the developing roller on the side of the supporting face plate on the side where the displacement amount is large.
The invention according to claim 31 is the imaging device according to claim 25, 26, 27, 28, 29, or 30, wherein the operation position of the inter-support-surface-plate tilt adjusting means is set to the first support surface plate or the second support surface. Of the face plates, the image forming device is placed on a support face plate that is easily accessible when the image forming device is placed on the image forming apparatus body, and the support face plate changes the inclination of the second support face plate with respect to the first support face plate. In this case, the displacement amount of the photosensitive member bearing member when it is made to be smaller than the other is the supporting face plate side.
The invention of claim 32 provides at least image forming means comprising a photoconductor and a developing means, and the process cartridge detachable from the main body of the image forming apparatus has the image forming means as claims 15 to 31. Any one of the above image forming devices is provided.
The invention of claim 33 is an image forming apparatus comprising at least an image forming means comprising a photosensitive member and a developing means, and the image forming apparatus according to any one of claims 15 to 31 is provided as the image forming means. It is characterized by.
According to a thirty-fourth aspect of the present invention, in the image forming apparatus according to the thirty-third aspect, the inclination of the second support face plate relative to the first support face plate is adjusted with respect to a part of the second support face plate. The second support face plate is displaceable in the axial direction of the rotation shaft with respect to the image forming apparatus main body in a state where the image forming apparatus is disposed in the image forming apparatus main body. It is characterized by being.
Further, the invention of claim 35 is characterized in that a plurality of longitudinal members arranged in parallel in the longitudinal direction, a first support face plate that supports one end in the longitudinal direction of the plurality of longitudinal members, and the plurality of longitudinal members interposed therebetween. In a longitudinal member device that is disposed opposite to the first support face plate and has a second support face plate that supports the other longitudinal end of the plurality of longitudinal members, the inclination of the second support face plate with respect to the first support face plate 2 of the plurality of longitudinal members by changing the inclination of the second support face plate relative to the first support face plate by the support face plate inclination adjusting means. The distance between the members is adjusted.

The method for adjusting the distance between rollers according to claim 1 and the roller device according to the invention of the roller device according to claim 6 will be described with reference to FIGS.
A roller device 9 in FIG. 1 has a first roller 60 and a second roller 61 as two roller members to be subjected to a distance between rollers, and the first roller rotating shaft (65) and the second roller rotating shaft. A first support face plate 91 and a second support face plate 92 that support both ends of (63). Further, an inter-roller gap G is formed between the surface of the second roller 61 and the surface of the first roller 60.
Here, as shown in FIG. 1, assuming that the first support face plate 91 and the second support face plate 92 are in parallel, the first roller 60 and the second roller 61 indicated by a one-dot chain line in this figure Let L0 be the distance between the rotation centers.
When the inclination of the second support surface plate 92 with respect to the first support surface plate 91 is changed so that the second support surface plate 92 of the roller device 9 is inclined in the arrow α direction or β direction in the drawing from the initial state shown in FIG. The distance between the rotation centers of the first roller 60 and the second roller 61 on the support face plate 92 side is displaced in a direction narrower than L0, and the distance between the rotation centers is narrowed. Thereby, it can adjust so that the gap G between rollers by the side of the 2nd support surface board 92 may be narrowed. Thus, by changing the inclination of the second support surface plate 92 with respect to the first support surface plate 91, the positions of the rotation shaft (65) of the first roller and the rotation shaft (63) of the second roller with respect to the second support surface plate 92. The gap G between the rollers can be adjusted without displacing.

FIG. 2 is an explanatory diagram of the roller device 9 in which the first roller bearing 64 is disposed at a position that is offset with respect to the second support face plate 92.
As in FIG. 1, assuming that the first support face plate 91 and the second support face plate 92 are parallel to each other in the initial state, between the rotation centers of the first roller 60 and the second roller 61 indicated by the alternate long and short dash line in the figure. Is a distance L0. In addition, the center of the rotation shaft at the position supported via the first roller bearing 64 of the first roller shaft 65a which is the rotation shaft of the first roller 60 supported by the second support surface plate 92, and the second support surface plate The distance between the second roller shaft 63a, which is the rotation shaft of the second roller 61 supported by 92, and the center of the rotation shaft at the position supported via the second roller bearing 62 is L1. At this time, since the first roller bearing 64 is disposed such that the position of the rotation shaft in the axial direction is offset with respect to the second support face plate 92, L1> L0.
And if the inclination of the 2nd support surface plate 92 with respect to the 1st support surface plate 91 is changed so that the 2nd support surface plate 92 of the roller apparatus 9 may incline in the arrow (alpha) direction in the figure, the 1st roller 60 by the side of the 2nd support surface plate 92 will be demonstrated. The distance between the rotation centers of the second roller 61 and the second roller 61 changes so as to approach L1 from L0, and the distance between the rotation centers increases. Thereby, it can adjust so that the gap G between rollers by the side of the 2nd support surface board 92 may be expanded. Further, when the inclination of the second support surface plate 92 with respect to the first support surface plate 91 is changed so that the second support surface plate 92 of the roller device 9 is inclined in the direction of arrow β in the figure, the first roller 60 on the second support surface plate 92 side. The distance between the rotation centers of the second roller 61 and the second roller 61 changes so as to be narrower than L0, and the distance between the rotation centers becomes narrower. Thereby, it can adjust so that the gap G between rollers by the side of the 2nd support surface board 92 may be narrowed. Thus, by changing the inclination of the second support surface plate 92 with respect to the first support surface plate 91, the positions of the first roller shaft 65a and the second roller shaft 63a with respect to the second support surface plate 92 are not displaced, so The gap G can be adjusted.

1 and 2, the first roller 60 and the second roller 61 are separated from each other, and the inclination of the second support surface plate 92 with respect to the first support surface plate 91 is changed. In this configuration, the gap G between the rollers can be adjusted. The roller device 9 according to the present invention is not limited to one in which two roller members are separated from each other, but may be one in which two roller members are in contact with each other to form a nip. If the two roller members form a nip, the distance between the rotation centers by changing the inclination of the second support face plate 92 with respect to the first support face plate 91 as described with reference to FIGS. By adjusting the nip, the nip pressure and the nip width can be adjusted.
In addition, since the tilt of the support face plate and the position of the rotation center of the roller member are displaced, there is an influence on the assembly of each member constituting the roller device and a drive source (not shown) that transmits the drive to the roller device. Conceivable. However, the adjustment of the distance between the rollers of the roller device 9 is performed in order to adjust the variation in the distance between the rollers caused by an error in parts accuracy or an error in assembly accuracy. This is an effect that can be absorbed by the deformation of.

According to invention of Claim 1 thru | or 33, the position of the rotating shaft of the two roller members used as the object of the distance between rollers with respect to a support surface plate is displaced by changing the inclination of the 2nd support surface plate with respect to a 1st support surface plate. Without any problem, the distance between the rollers can be adjusted.
According to the invention of claim 34, by changing the inclination of the second support face plate with respect to the first support face plate, the fixing position of the two longitudinal members which are the target of the distance between the members with respect to the support face plate is displaced with respect to the support face plate. There is an excellent effect that the distance between the members can be adjusted without causing them to occur.

Hereinafter, an embodiment of an electrophotographic printer (hereinafter simply referred to as a printer 100) will be described as an image forming apparatus to which the present invention is applied.
First, the basic configuration of the printer 100 will be described. FIG. 3 is a schematic configuration diagram illustrating the printer 100 according to the present embodiment.
As shown in FIG. 3, the printer 100 includes four image forming process units 10Y, 10C, 10M, and 10K for yellow, cyan, magenta, and black (hereinafter referred to as Y, C, M, and K). These use Y, C, M, and K toners of different colors as image forming substances for forming an image, but the other configurations are the same. Taking the Y image forming process unit 10Y for generating a Y toner image as an example, around the photoreceptor 1Y that is rotated in the counterclockwise direction (arrow A direction in the figure) by a driving means (not shown). , A cleaning device 6Y, a charge eliminating unit (not shown), a charging device 2Y, an optical writing device 3Y, a developing device 4Y, and the like.

  The charging device 2Y disposed so as to face the photoreceptor 1Y is a charging charger in which a charging bias is applied to a charging wire from a charging bias power source (not shown). Then, the charging device 2Y generates a discharge with the photoreceptor 1Y, so that the surface of the photoreceptor 1Y is uniformly charged. Instead of the charging device 2Y using the charging charger, a charging roller may be disposed so as to be in contact with the photosensitive member 1Y or opposed to the photosensitive member 1Y with a predetermined gap to uniformly charge the photosensitive member 1. Good.

  The surface of the photoreceptor 1Y that is uniformly charged by the charging device 2Y is exposed and scanned by the scanning light emitted from the optical writing device 3Y and carries a Y electrostatic latent image. The optical writing device 3Y emits laser light or LED light modulated based on image information sent from an external personal computer or the like.

The developing device 4Y as developing means is a developing region facing the photoreceptor 1Y, and develops the electrostatic latent image by attaching Y toner to the electrostatic latent image carried on the surface of the photoreceptor 1Y by a known technique. To obtain a Y toner image. This Y toner image is primarily transferred to the intermediate transfer belt 7.
The developing device 4Y shown in FIG. 3 includes two developing rollers, an upper developing roller 411Y and a lower developing roller 412Y, as developing rollers. When developing the latent image on the photoconductor 1Y using two developing rollers to increase the peripheral speed of the photoconductor 1Y, the latent image is more reliably generated than when developing with one developing roller. Development can be performed. As a developing device using two developing rollers, for example, the one described in Japanese Patent Laid-Open No. 20007-311915 can be used.

  The cleaning device 6Y removes transfer residual toner attached to the surface of the photoreceptor 1Y after the primary transfer process. The cleaning device 6 is provided with a cleaning brush so as to contact and rub against the surface of the photosensitive member downstream of the cleaning blade with respect to the rotation direction of the photosensitive member, and further provided with a toner recovery roller in contact with the cleaning brush. A configuration in which toner is removed from the collection roller by a rubber blade can be applied. The cleaning device is not limited to this configuration. The surface of the photoreceptor 1Y that has been subjected to the cleaning process by the cleaning device 6Y is neutralized by a neutralizing unit such as a neutralizing lamp (not shown) to prepare for the next image formation.

  In FIG. 3, C, M, and K toner images are similarly formed on the photoreceptors 1 </ b> C, M, and K in the image forming process units 10 </ b> C, M, and K for other colors, and are formed on the intermediate transfer belt 7. Intermediate transfer.

  Below the image forming process units 10Y, 10C, 10M, and 10K, the intermediate transfer belt 7 that is a toner image carrier is stretched and moved endlessly in the clockwise direction (the arrow B direction in the figure). A unit 70 is provided. The transfer unit 70 serving as a transfer unit includes an intermediate transfer belt 7, a secondary transfer counter roller 71, two stretching rollers (7a, 7b), and four primary transfer chargers 5Y, 5C, 5M as primary transfer members. , K, secondary transfer roller 8, belt cleaning device (not shown), and the like.

  The intermediate transfer belt 7 is stretched by a first stretching roller 7a, a second stretching roller 7b, and a secondary transfer counter roller 71 disposed on the inner side of the loop. One is driven to rotate endlessly clockwise in the figure.

  The four primary transfer chargers 5Y, 5C, 5M, and 5K are opposed to the photoreceptors 1Y, 1C, 1M, and 1K with the intermediate transfer belt 7 moved endlessly in this way, and are for Y, C, M, and K, respectively. A primary transfer portion is formed. Then, a transfer bias having a polarity opposite to that of the toner (for example, plus) is applied to the back surface (loop inner peripheral surface) of the intermediate transfer belt 7. The intermediate transfer belt 7 sequentially passes through the primary transfer portions for Y, C, M, and K along with the endless movement thereof, and the surface of the intermediate transfer belt 7 is placed on the photoreceptors 1Y, 1C, 1M, and 1K. Y, C, M, and K toner images are superimposed and primarily transferred. As a result, a four-color superimposed toner image (hereinafter referred to as a four-color toner image) is formed on the intermediate transfer belt 7. The primary transfer member constituting the primary transfer unit is not limited to the transfer charger, and is, for example, a primary transfer roller that forms a primary transfer nip by sandwiching the intermediate transfer belt 7 with the photoreceptor 1. Also good.

  A secondary transfer roller 8 to which a secondary transfer bias output from a power source (not shown) is applied is disposed outside the loop of the intermediate transfer belt 7, which is connected to a secondary transfer counter roller 71 inside the belt loop. A secondary transfer nip is formed by sandwiching the intermediate transfer belt 7 therebetween.

  A sheet feeding cassette (not shown) is disposed below the transfer unit 70. In this paper feed cassette, a plurality of recording papers P as recording media are accommodated in a stack of recording papers, and the uppermost recording paper P is placed in a paper feeding path (not shown) at a predetermined timing. Send it out. A registration roller pair 81 is disposed at the end of the paper feed path. The registration roller pair 81 temporarily stops the rotation of both rollers as soon as the recording paper P conveyed between the rollers rotating while abutting each other is sandwiched. Then, the recording paper P is sent toward the secondary transfer nip at a timing at which the recording paper P can be synchronized with the four-color toner image on the intermediate transfer belt 7.

  The four-color toner image formed on the intermediate transfer belt 7 has a secondary transfer electric field formed between the secondary transfer roller 8 to which a secondary transfer bias is applied and the grounded secondary transfer counter roller 71. Due to the influence of the nip pressure, batch transfer is performed onto the recording paper P in the secondary transfer nip. Then, combined with the white color of the recording paper P, a full color toner image is obtained.

  Untransferred toner that has not been transferred to the recording paper P adheres to the intermediate transfer belt 7 after passing through the secondary transfer nip. This is removed by a belt cleaning device (not shown) in which the intermediate transfer belt 7 is sandwiched between the first stretching roller 7a.

  A fixing device (not shown) is disposed on the left side of the secondary transfer nip in the drawing. As is well known in electrophotographic image forming apparatuses, this fixing device fixes a toner image on a recording sheet by pressurization or heating.

  In the printer 100 having the above basic configuration, the four image forming process units 10Y, 10C, 10M, and 10K have toner images on the endlessly moving surfaces of the photoreceptors 1Y, 1C, 1M, and 1K that are latent image carriers. It functions as a toner image forming means for forming the toner. The combination of the four image forming process units 10Y, 10C, 10M, and 10K and the transfer unit 70 includes a toner image forming unit that forms a toner image on the endless moving surface of the intermediate transfer belt 7 that is a toner image carrier. Is functioning as

Next, an image forming apparatus that integrally supports the developing devices 4Y, C, M, and K and the photoreceptors 1Y, C, M, and K included in the four image forming process units 10Y, 10C, 10M, and 10K. The image forming units 200Y, 200C, 200M, and 200K will be described. Since the image forming units 200Y, 200C, 200M, and 200K have the same configuration except that the colors of the toners used are different, the following description omits Y, C, M, and K.
FIG. 4 is a schematic sectional view of the image forming unit 200. The image forming unit 200 according to the present embodiment integrally supports a cleaning device 6, a static eliminator (not shown), and a charging device 2 as image forming members other than the developing device 4 and the photoreceptor 1, and is attached to and detached from the printer 100 main body. It is possible. The image forming unit 200 is not configured to integrally support the optical writing device 3Y which is a latent image forming unit, but a member constituting the latent image forming unit is also detachable from the printer 100 main body as the image forming unit 200. It may be configured.
The developing device 4 includes a supply screw 51 that supplies the developer to the upper developing roller 411 and the lower developing roller 412 that are the two developing rollers 41 while conveying the developer from the near side to the far side in FIG. Further, a recovery screw 52 is provided that recovers the developer that has been supplied to the developing roller and has passed through the developing region that is the opposite portion between the developing roller and the photosensitive member 1 and that transports the developer from the near side to the far side in FIG. . Further, a circulation screw 53 is provided for delivering the developer reaching the downstream end in the transport direction of the collection screw 52 to the upstream end in the transport direction of the supply screw 51 and circulating the developer. The circulation screw 53 is located at the back end in FIG. 4 of the developing device 4 from the back side to the front side so as to be the same height as the recovery screw 52 and at the front side end to be the same height as the supply screw 51. It arrange | positions so that it may become diagonally upward. Here, the space in which the supply screw 51 of the developing device 4 is arranged is circulated in the supply conveyance path 51a, the space in which the collection screw 52 is arranged is collected in the collection conveyance path 52a, and the space in which the circulation screw 53 is arranged. Let it be a conveyance path 53a. Further, an upper developing roller 411 and a lower developing roller 412 are arranged, and a space facing the photoreceptor 1 is defined as a developing chamber 59. Further, the developing device 4 includes a catch roller 56 that faces the photosensitive member 1 below the lower developing roller 412.

  The upper developing roller 411 and the lower developing roller 412 disposed below the upper developing roller 411 are each composed of a non-magnetic pipe that is driven to rotate in the clockwise direction in the figure by a driving means such as a motor or a drive transmission system (not shown). It has a sleeve and a magnet roller (not shown) that is included so as not to be rotated.

  The developing chamber 59 that houses the upper developing roller 411 and the lower developing roller 412 has an opening in the wall facing the photoconductor 1, and from there, the peripheral surface of the developing sleeve of the two developing rollers 41. Some are exposed. A supply conveyance path 51a and a collection conveyance path 52a communicate with each other on the opposite side of the developing chamber 59 from the opposite side to the photosensitive member 1 over the entire area in the axial direction of both developing rollers. The supply conveyance path 51a is disposed directly above the collection conveyance path 52a in the vertical direction, and both the supply conveyance path 51a and the collection conveyance path 52a extend over the entire area in the longitudinal direction on the right side (photoconductor side) in the drawing. It communicates with the developing chamber 59.

  The supply screw 51 disposed in the supply conveyance path 51 a is in a posture that extends in the horizontal direction in the same manner as the photoconductor 1 and the both developing rollers 41. The supply screw 51 includes a rod-shaped rotating shaft member and a screw blade that is spirally provided on the peripheral surface of the rod-shaped rotating shaft member. It is rotationally driven integrally in the rotating direction.

  The recovery screw 52 accommodated in the recovery conveyance path 52 a also has a posture extending in the horizontal direction, like the photoconductor 1, the both developing rollers 41, and the supply screw 51. Then, the rotating shaft member and the screw blade are integrally rotated in the clockwise direction in the drawing by a driving means (not shown).

  A circulation conveyance path 53a is adjacent to the supply conveyance path 51a and the collection conveyance path 52a on the side opposite to the developing chamber 59 side. Unlike the other developer conveyance paths, the circulation conveyance path 53a is formed to extend in a posture inclined from the horizontal direction. The circulating screw 53 in which screw blades are erected on the peripheral surface of the rotating shaft member also extends in an inclined posture in the circulating conveyance path 53a, and is rotated counterclockwise in the drawing by a driving means (not shown). It is rotationally driven in the direction. The circulation conveyance path 53a is largely partitioned from the supply conveyance path 51a and the collection conveyance path 52a by a partition wall 58. However, the opening provided in the partition wall 58 partially communicates with the supply conveyance path 51a and the collection conveyance path 52a.

  In the supply conveyance path 51a, the developer (not shown) held in the blades of the supply screw 51a is conveyed from the front side to the back side in the direction orthogonal to the drawing sheet as the supply screw 51 rotates. . In the course of this conveyance, the developer is sequentially supplied to the developing sleeve (hereinafter referred to as the upper developing sleeve) of the upper developing roller 411 in the developing chamber 59. Then, it is pumped up to the upper developing sleeve by the magnetic force of the magnet roller in the upper developing sleeve.

  The developer pumped up by the upper developing sleeve is regulated in layer thickness on the upper developing sleeve by a doctor blade 57 whose tip is opposed to the surface of the upper developing sleeve via a predetermined gap. Then, the toner is transported to the first development area facing the photosensitive member 1 and contributes to development here.

  The developer transported to the vicinity of the downstream end of the supply screw 51 in the agent transport direction (near the rear end in the figure) without being drawn up by the upper developing sleeve is not shown provided on the bottom wall of the supply transport path 51a. Falls into the collection conveyance path 52a.

  Further, as the upper developing sleeve rotates, the developer that has been transported to the first developing area where the upper developing sleeve and the photosensitive member 1 face each other and contributes to the development is then moved to the first developing region along with the rotation of the upper developing sleeve. Pass through the development area. Then, the toner is transferred to a developing sleeve (hereinafter referred to as a lower developing sleeve) of a lower developing roller 412 disposed below the upper developing roller 411. Thereafter, with the rotation of the lower developing sleeve, the lower developing sleeve and the photosensitive member 1 are sent to the second developing region facing each other, where they contribute again to the development. The developer that has completed the second development step is transported to a communication position between the developing chamber 59 and the recovery transport path 52a. Then, after separating from the surface of the lower developing sleeve due to the influence of the repulsive magnetic field formed by the magnet roller of the lower developing roller 412, it falls into the collection conveyance path 52 a.

  After passing through the second developing area along with the rotation of the lower developing sleeve, the developer that has separated from the surface of the lower developing sleeve at a position relatively distant from the recovery conveyance path 52a was disposed immediately below the lower developing sleeve. By the rotational force of the catch roller 56, it is conveyed toward the collection conveyance path 52a.

  In the collection conveyance path 52 a, the developer (not shown) held in the blades of the collection screw 52 is conveyed from the near side to the back side in the direction orthogonal to the drawing sheet as the collection screw 52 rotates. In this conveyance process, toner is supplied to the developer in the collection conveyance path 52a by a toner supply device (not shown). Further, the developer falling from the drop opening of the supply conveyance path 51a is taken in. Thereafter, the developer conveyed to the vicinity of the downstream end of the collection screw 52 in the agent conveyance direction (near the rear end in FIG. 2) passes through the opening provided in the partition wall 58 and enters the circulation conveyance path 53a. Enter.

  The developer that has entered the circulation conveyance path 53a is taken into the upstream end of the circulation screw 53a in the agent conveyance direction. Then, as the circulating screw 53a is disposed in an obliquely upward posture from the upstream side in the agent transport direction to the downstream side in the agent transport direction, it is transported with an ascending gradient. When the developer is transported to the vicinity of the downstream end of the circulation screw 53 in the agent transport direction, the developer passes through the opening provided in the partition wall 58 and is returned to the supply transport path 51a. And it is taken in into the agent conveyance direction upstream edge part of the supply screw 51. FIG.

FIG. 5 is an explanatory perspective view of the image forming unit 200, in which an image forming member other than the developing device 4 and the photoreceptor 1 is detached from the image forming unit 200. FIG. 6 is a schematic top view of the image forming unit 200. The image forming unit 200 is a roller device including the photosensitive member 1 and the developing roller 41 as a plurality of roller members arranged so that the rotation axes are parallel to each other.
In the image forming unit 200 shown in FIG. 6, a developing gap measuring jig 1 a that measures the developing gap PG is installed instead of the photoreceptor 1. Further, the parts described with reference to the development gap measuring jig 1a are the same for the photosensitive member 1. As shown in FIG. 6, the development gap measurement jig 1 a includes development gap measurement units at both end portions and a central portion in the axial direction of the rotation shaft of the development roller 41. Further, the developing device 4 includes two developing rollers (411, 412). FIG. 6 schematically shows the positional relationship between the developing roller and the photosensitive member 1. Only one roller 41 is shown. The photoreceptor 1 included in the image forming unit 200 is an OPC photoreceptor, and the size thereof is φ100 [mm], and the sizes of the upper developing roller 411 and the lower developing roller 412 are both φ30 [mm].
The image forming unit 200 is attached to the main body of the printer 100 by sliding in the direction of arrow C in the drawing. Here, the direction of arrow C in the figure, which is the sliding direction of the image forming unit 200, is referred to as the unit rear side, and the opposite side of the unit rear side is referred to as the unit front side. FIG. 5A is a perspective explanatory view seen from the rear side of the unit, and FIG. 5B is a perspective explanatory view seen from the front side of the unit.
As shown in FIGS. 5 and 6, the image forming unit 200, which is an image forming apparatus, forms a development gap PG between the photosensitive member 1 and the surface of the photosensitive member 1, so A developing device 4 including developing rollers 41 (411 and 412) for developing the latent image is provided. Further, the front plate 210 which is a first support face plate for supporting the end portions of the photosensitive member 1 and the developing device 4 on the unit front side in the axial direction of the rotating shaft of the photosensitive member 1, and the photosensitive member 1 and the developing device 4 are sandwiched. It has a rear plate 220 that is disposed opposite to the front plate 210 and is a second support face plate that supports the rear end of the photoconductor 1 and the developing device 4 on the rear side of the unit. Further, as a stay member that determines the axial distance between the front plate 210 and the rear plate 220, a plate-like stay 230 made of metal is provided on the right side when viewed from the front plate 210 side. Further, the axial distance between the left front plate 210 and the rear plate 220 when viewed from the front plate 210 side is determined by the developing device 4, and the developing device 4 functions as a left stay member. The front plate 210 includes a drum knob holder 212 and a drum knob 211. As shown in FIG. 6, the drum knob 211 incorporates a second photoreceptor bearing 14 formed of a ball bearing as a bearing member for the second photoreceptor shaft 13b.
Further, the rear plate 220 is provided with a bearing holder 221 and a photoreceptor bearing 12 including a ball bearing. In addition, a driving gear and a coupling for transmitting the driving force to the photosensitive member 1 are placed in the recessed portion of the bearing holder 221.
The drum knob holder 212 and the bearing holder 221 are resin members formed by outsert molding. These resin members are used to position the image forming unit 200 having two face plates on the main body side of the printer 100 and the photosensitive member 1 when the printer 100 is set on the main body, and the photosensitive member 1 included in the unit 100. Therefore, it is molded with resin. For positioning, it is preferable to use a member made of resin molding, but if the whole face plate is molded with resin, there will be a problem of strength, so the shape of the whole face plate is made out of sheet metal to give strength, On the other hand, outsert resin molding is selected for a portion that requires accurate positioning. Here, the resin member that is outsert-molded simultaneously with the drum knob holder 212 in the front plate 210 is provided in the shaft fixing portion 47 described later with reference to FIG. 16 or the front plate 210 described later with reference to FIG. There are fixed hole forming members (106b, 107b) formed with respect to the fitting holes (106a, 107a). In addition, as a resin member that is molded into the rear plate 220 at the same time as the bearing holder 221, there is a developing roller bearing holder 142 in which the developing roller shaft 43a is positioned via the developing roller bearing 42.
A development gap PG is formed between the surface of the developing roller 41 and the surface of the photoreceptor 1.

  Further, an eccentric holder 45 that positions the second developing roller shaft 43b of the developing roller 41 with respect to the front plate 210 is provided. Although details will be described later, the position of the second developing roller shaft 43b relative to the front plate 210 can be adjusted in the direction of arrow D in FIG.

  FIG. 7 is an explanatory perspective view of a state in which one of the image forming units 200 is pulled out from the printer 100 main body. In FIG. 7, the photoconductor 1 is removed from the drawn image forming unit 200. The image forming unit 200 attached to the printer 100 is supported by a first slide rail 110 and a second slide rail 120 shown in FIG. Therefore, the image forming unit 200 can be pulled out to the front side of the printer 100 by the first slide rail 110 and the second slide rail 120 as shown in FIG. As shown in FIG. 7, when the image forming unit 200 is pulled out, the front side of the unit is easy to access, but the rear side of the unit is difficult to access.

The image forming unit 200 according to the present embodiment adjusts the development gap PG, which is the gap between the photosensitive member 1 and the two development rollers 41 (upper development roller 411 and lower development roller 412) in the unit state, so that the unit is a unit. The printer 100 is installed in the printer 100 with the development gap PG adjusted.
As shown in FIG. 7, a photosensitive member drive shaft 113 that transmits driving to the photosensitive member 1 is disposed on the printer 100 main body side. Then, by mounting the image forming unit 200 on which the photosensitive member 1 is disposed on the printer 100 main body, the photosensitive member driving shaft 113 is connected to the hole (113a) of the first photosensitive member shaft 13a and the second photosensitive member shown in FIG. The photosensitive member 1 is engaged with the hole (113b) of the body shaft 13b. Thereby, the rotational drive of the photosensitive member drive shaft 113 can be transmitted to the photosensitive member 1.

FIG. 8 is an explanatory perspective view of the image forming unit 200 shown in FIG. 5 with the photoreceptor 1 removed. FIG. 9 is a perspective explanatory view showing a state in which each member is removed from the front plate 210 and the rear plate 220 of the image forming unit 200 shown in FIG. FIG. 10 is a perspective explanatory view showing a state in which each member is removed from the front plate 210 and the rear plate 220 of the image forming unit 200 with the photosensitive member 1 shown in FIG. 5 removed (state shown in FIG. 8). 8 to 10, (a) is a perspective explanatory view seen from the rear side of the unit, and (b) is a perspective explanatory view seen from the front side of the unit.
11 is an explanatory view of the front plate 210, FIG. 11 (a) is a perspective explanatory view of the front plate 210 viewed from the rear side of the unit, and FIG. 11 (b) is a front view of the front plate 210 from the front side of the unit. FIG. 12 is an explanatory view of the rear plate 220, FIG. 12 (a) is a perspective explanatory view of the rear plate 220 viewed from the rear side of the unit, and FIG. 12 (b) is a rear plate from the front side of the unit. FIG. 11 and 12, the reference numeral with “a” is a screw corresponding to the numeral or a fitting hole of the eccentric holder.

In the image forming unit 200, the developing device 4 and the front plate 210 have the second developing roller shaft 43 b of the developing roller 41 as a positioning reference, and the developing device 4 and the rear plate 220 have the first developing roller shaft of the developing roller 41. It is fixed by screwing at a positioning reference via a developing roller bearing 42 which is a ball bearing fitted to 43a. As shown in FIGS. 8 to 10, the developing device 4 and the front plate 210 are fixed by a first developing front screw 941, a second developing front screw 942, and a third developing front screw 943. Further, the developing device 4 and the rear plate 220 are fixed by a first development rear surface screw 944, a second development rear surface screw 945, and a third development rear surface screw 946.
The rear plate 220 is a bearing member of the first developing roller shaft 43a (431a and 432a in FIG. 8) of the developing roller 41 (411 and 412 in FIG. 8), and the developing roller with respect to the rear plate 220. After a developing roller bearing 42 (not shown in FIG. 8) for positioning 41 is set, a driving gear and a coupling for transmitting driving to the first developing roller shaft 43a (431a and 432a in FIG. 8) are attached. It is done. For this reason, since many members such as a drive gear are provided on the outside of the rear plate 220 of the image forming unit 200, it is difficult to arrange an adjustment mechanism for adjusting the developing gap PG on the rear plate 220 side. . Although not shown in FIGS. 8 to 10, the developing roller bearing 42 is disposed for each of 431a and 432a.

  The plate stay 230 and the front plate 210 are fixed by the first stay front screw 931 and the second stay front screw 932, and the plate stay 230 and the rear plate 220 are fixed by the first stay rear screw 933 and the second stay front screw 932. It is fixed by a two-stay rear surface screw 934.

  Regarding the span between the front plates, which is the distance between the front plate 210 and the rear plate 220, the second span S2 on the left side when viewed from the front plate 210 side is constant because the developing device 4 functions as a fixed stay member. Yes. On the other hand, the first span S1 on the right side when viewed from the front plate 210 side can be changed by changing the number of shims 231 as spacer members between the front plate 210 and the plate-like stay 230. Specifically, the plate-like stay 230 is set so that the shim 231 is sandwiched between the plate-like stay 230 and the front plate 210 in the initial setting state, and the length of the plate-like stay 230 in the axial direction is longer than the length of the developing device 4. It is set short. The first span S1 can be changed by increasing or decreasing the number of shims 231 from the initial setting state.

In the image forming unit 200, two shims 231 are mounted in an initial setting state. Then, by increasing the number of shims 231 mounted, the first span S1 becomes longer. Thereby, the rear plate 220 is bent so as to be inclined in the direction of the arrow α in FIG. When the rear plate 220 is bent, the position of the photosensitive member bearing 12 which is a ball bearing fixed to the rear plate 220 is displaced in the direction of the arrow γ in FIG. As described above, the displacement of the photosensitive member bearing 12 enables adjustment in the direction in which the developing gap PG on the rear plate 220 side widens in the same manner as the roller device 9 described with reference to FIG.
On the other hand, when the number of shims 231 is decreased, the first span S1 is shortened, and the rear plate 220 is bent so as to incline in the direction of arrow β in FIG. On the contrary, it is possible to adjust the direction in which the development gap PG is narrowed.

Next, mounting of the shim 231 will be described. FIG. 13 is an enlarged explanatory view of the vicinity of the fixing portion between the front plate 210 and the plate-like stay 230 in FIG. FIG. 14 is an enlarged explanatory view of the vicinity of the fixing portion between the front plate 210 and the plate-like stay 230 with the shim 231 mounted.
In the plate-like stay 230, tap holes are formed in the first fixing portion 232 that is fixed to the first stay front screw 931 and the second fixing portion 233 that is fixed to the second stay front screw 932. Has been. When the shim 231 is mounted, the first stay front screw 931 and the second stay front screw 932 are loosened to create a space between the front plate 210 and the plate stay 230, or as shown in FIG. The front plate 210 and the plate-like stay 230 are removed. Then, with the first stay front screw 931 and the second stay front screw 932 inserted in the fitting hole of the front plate 210, the shim 231 is attached to the first stay front screw 931 and the second stay front screw 932. Attach so that the two U-shaped grooves fit.
Specifically, as shown by an arrow E, the right U-shaped groove of the shim 231 in FIG. 13 is fitted to the second stay front screw 932. Then, with the second stay front screw 932 fitted in one of the U-shaped grooves, the shim 231 is rotated counterclockwise in FIG. 13, so that the left U-shaped groove of the shim 231 in FIG. The first stay front screw 931 is fitted from above. As a result, the shim 231 is supported by the first stay front screw 931 and the second stay front screw 932. In this state, the first stay front screw 931 and the second stay front screw 932 are tightened with respect to the tap holes of the first fixing portion 232 and the second fixing portion 233 of the plate-like stay 230, as shown in FIG. The shim 231 is sandwiched between the plate-like stay 230 and the front plate 210. Further, the number of the shims 231 can be adjusted by attaching them in a stacked manner.

In the image forming unit 200, in response to the change of the first span S1, the front plate 210 and the rear plate 220 generate beam-like deflection displacements when the developing device 4 side is a fixed end. With this deflection displacement, the ball bearings (12, 14) that hold and position the photoreceptor 1 are also displaced.
However, the image forming unit 200 has the following configuration.
As shown in FIG. 11, the front plate 210 has a larger member area than the rear plate 220, and the end portion is bent. For this reason, bending strength is large and the deformation amount by bending is small. Further, as shown in FIG. 6, the offset amount W <b> 2 of the second photoconductor bearing 14 that is a ball bearing fixed to the front plate 210 with respect to the front plate 210 is a photoconductor bearing that is a ball bearing fixed to the rear plate 220. 12 is smaller than the offset amount W1 with respect to the rear plate 220. For this reason, in the displacement of the ball bearing with respect to the deflection deformation, the displacement amount in the PG direction is small.
On the other hand, as shown in FIG. 12, the rear plate 220 has a smaller member area than the front plate 210 and is not bent at the end. For this reason, bending strength is small and the deformation amount by bending is large. Further, as shown in FIG. 6, the offset amount W1 with respect to the rear plate 220 of the photoreceptor bearing 12 is larger than the offset amount W2 with respect to the front plate 210 of the second photoreceptor bearing 14. For this reason, in the displacement of the ball bearing with respect to the deflection deformation, the displacement amount in the PG direction becomes large.

Thus, by making the bending strength of the rear plate 220 smaller than that of the front plate 210, the rear plate 220 can be mainly deformed when the first span S1 is changed, and deformation of the front plate 210 can be suppressed. . Furthermore, by making the offset amount W1 of the photosensitive member bearing 12 larger than the offset amount W2 of the second photosensitive member bearing 14, the photosensitive member bearing 12 can be mainly displaced when the first span S1 is changed. The displacement of the second photoconductor bearing 14 can be suppressed.
As a method of setting a difference in bending strength between the front plate 210 and the rear plate 220, the front plate 210 has a difference in thickness so that the plate thickness is thicker, or the rear plate 220 is notched. A shape may be added.
As described above, the image forming unit 200 has a configuration in which the bending strength of the rear plate 220 is smaller than that of the front plate 210, and the offset amount W1 of the photoconductor bearing 12 is larger than the offset amount W2 of the second photoconductor bearing 14. . With such a configuration, the change amount of the development gap PG when the first span S1 is changed is set to have a relationship of (front PG change amount) << (rear PG change amount). Can do.

  FIG. 15 is a graph showing the measurement of the change in the development gap with respect to the number of shims 231 mounted in the image forming unit 200. In FIG. 15, the measurement position of the development gap PG of the upper developing roller 411 is indicated by upper −F, upper −C, and upper −R in this order from the front side, the center, and the rear side. The measurement positions of the gap PG are indicated by lower -F, lower -C, and lower -R in the order of the front side, the center, and the back side. Since the shim has a thickness of 0.2 [mm] and the image forming unit 200 has two shims 231 in the initial setting, the state of two shims is set as the PG displacement amount 0 [mm]. When the number of shim sheets is 3 or 4, the number of shim sheets is increased, that is, the first span S1 is adjusted to be widened, and the number of shim sheets is 1 or 0. This is a state in which the number of shims is reduced, that is, a state in which the first span S1 is adjusted to be narrowed. R, C, and F in FIG. 15 indicate PG changes on the back side, the center, and the front side. Here, as shown in FIG. 6, since the measurement position of the front development gap PG is within the image forming width inside the front plate 210, the front development gap PG measurement value is the rear development gap. It is influenced by the change of gap PG.

The adjustment of the development gap PG by changing the first span S1 described above is an adjustment mainly for adjusting the development gap PG on the rear side, although it affects the development gap PG on the front side.
FIG. 16 is an explanatory diagram of the front plate 210 having a configuration in which the positioning of the second developing roller shaft 43 b with respect to the front plate 210 is performed not by the eccentric holder 45 but by the shaft fixing portion 47. In the method of changing the first span S1, when the positioning of the developing roller 41 with respect to the front plate 210 is a fixed position of the second developing roller shaft 43b with respect to the front plate 210 as shown in FIG. Adjustment is made so that the front-rear PG deviation is reduced by changing the first span S1 with reference to PG. However, when a more severe development gap PG tolerance range setting is required, after adjusting the rear development gap PG by the method of changing the first span S1, the front development gap PG is adjusted according to the value. It is preferable to provide a mechanism.

Next, adjustment of the front development gap PG in the image forming unit 200 will be described.
FIG. 17 is an explanatory diagram of the front plate 210 having a configuration in which the eccentric holder 45 positions the second developing roller shaft 43 b with respect to the front plate 210. 18 is an explanatory perspective view of the eccentric holder 45, and FIG. 18 (a) is a perspective view as seen from the rear side of the unit when attached to the front plate 210. FIG. 18 (b) These are the perspective views seen from the side used as the unit front side, when attaching to the front board 210. FIG.
The eccentric holder 45 is fitted with fitting holes (451a, 452a) of the front plate 210, and includes a face plate fitting portion 45b having a circular outer cross section, an adjusting screw fixing portion 45d, and a knob portion 45e. The face plate fitting portion 45b is provided with a shaft fitting hole 45a for fitting with the end portion of the second developing roller shaft 43b. The sectional shape of the shaft fitting hole 45a and the sectional shape of the outer shape of the face plate fitting portion 45b are both circular, but the shaft fitting hole 45a is an eccentric hole with respect to the outer shape of the face plate fitting portion 45b. Further, the adjustment screw fixing portion 45d is provided with an adjustment screw fixing hole 45c having a shape along the outer shape of the face plate fitting portion 45b.

FIG. 19 is an explanatory diagram of a configuration in which the front development gap PG is adjusted by the eccentric holder 45 (upper eccentric holder 451, lower eccentric holder 452).
The broken lines in FIG. 19 indicate the surface of the photoreceptor 1 and the surface of the developing roller 41. Since the eccentric holder 45 (451, 452) is fitted into the fitting hole of the front plate 210, the position of the eccentric holder 45 with respect to the photoreceptor 1 does not change. On the other hand, since the face plate fitting portion 45b of the eccentric holder 45 and the second developing roller shaft 43b are eccentric, the rotational center of the eccentric holder 45 is eccentric with respect to the rotational center 41p of the developing roller 41, and the eccentric holder 45 is By rotating, the developing roller 41 is displaced relative to the photoreceptor 1. In FIG. 19, by rotating the eccentric holder 45 in the clockwise direction (the direction of the arrow ε in FIG. 19), the developing roller 41 is displaced in the direction away from the photosensitive member 1 and adjusted so as to widen the front developing gap PG. can do. Conversely, by rotating the eccentric holder 45 in the counterclockwise direction (the direction opposite to the arrow ε in FIG. 19), the front developing gap PG can be adjusted to be narrowed. Thereby, as indicated by an arrow D in FIG. 6, the position of the second developing roller shaft 43b with respect to the front plate 210 can be adjusted.
When the front developing gap PG is adjusted by the eccentric holder 45, the eccentric holder adjusting screw 46 (461, 462) is loosened, the eccentric holder 45 is rotated, and the eccentric holder adjusting screw 46 is tightened to thereby adjust the eccentric holder. The development gap PG can be fixed in a state where the rotation of 45 is adjusted.
As shown in FIG. 19, the fitting hole 451a of the front plate 210 into which the upper eccentric holder 451 is fitted has a round hole shape, whereas the fitting of the front plate 210 into which the lower eccentric holder 452 is fitted. The hole 452a has a long hole shape. For this reason, the position of the lower eccentric holder 452 with respect to the front plate 210 can be displaced in the longitudinal direction of the fitting hole 452a. This is because the distance between the axes of the upper developing roller 411 and the lower developing roller 412 is determined in the developing device 4 so that the upper developing roller 411 does not fluctuate in the adjustment of the upper eccentric holder 451 and the lower eccentric holder 452. In this configuration, the delivery of the developer between the toner and the lower developing roller 412 is not affected.

Further, the image forming unit 200 includes an upper eccentric holder 451 and a lower eccentric holder 452 as the eccentric holder 45 for each of the upper developing roller 411 and the lower developing roller 412. Therefore, the upper eccentric holder 451 and the lower eccentric holder 452 can be independently rotated as indicated by an arrow η in FIG. 17, and the developing gap PG of the upper developing roller 411 and the developing gap of the lower developing roller 412 PG and each can be adjusted independently.
In the developing device 4 of the two-stage developing system including the two developing rollers 41 (411 and 412) like the image forming unit 200 of the present embodiment, the rear side as in the adjusting mechanism using the eccentric holder 45 described above. In accordance with the development gap PG, the two development rollers 41 are independently adjusted to adjust the front development gap PG, thereby improving the tolerance of the development gap PG in a narrow setting range and improving the deviation before and after the development gap PG. It becomes possible to make it compatible.

20 is a graph showing the measurement of the change in the development gap with respect to the rotation angle of the upper eccentric holder 451 in the image forming unit 200, and FIG. 21 is a graph showing the measurement of the change in the development gap with respect to the rotation angle of the lower eccentric holder 452. It is. The graphs shown in FIGS. 20 and 21 are measurement results in a state where three shims 231 are sandwiched between the plate-like stay 230 and the front plate 210, and are rotated in the direction of the arrow ε in FIG. The rotation angle in the plus direction is the rotation angle in the plus direction, and the rotation angle in the opposite direction is the rotation angle in the minus direction. Similarly to FIG. 15, the measurement position of the development gap PG of the upper developing roller 411 is indicated by upper −F, upper −C, and upper −R in this order from the front side, the center, and the rear side, and the lower developing roller The measurement position of the development gap PG 412 is indicated by lower -F, lower -C, and lower -R in this order from the front side, the center, and the back side.
The change in the development gap PG with respect to the rotation angle of the eccentric holder 45 shown in FIGS. 20 and 21 is independent of the change in the development gap PG due to the increase / decrease in the shim 231 described with reference to FIG. Additivity of quantity holds. For this reason, it is also possible to estimate the adjustment result by combining the change in the number of shim attachments and the change in the rotation angle of the eccentric holder based on the average change data.

In the image forming unit 200, the front development gap PG is adjusted by the eccentric holder 45, and the rear development gap PG is adjusted by changing the first span S1. By adjusting the development gap PG with such a configuration, there is no restriction due to the addition of the development gap adjustment mechanism on the rear side of the rear plate 220 having a drive gear train and a small layout margin. Further, since each roller shaft position with respect to the rear plate 220 on the driving side is not changed (not adjusted), there is no occurrence of gear meshing variation. Further, there is no need to worry about the displacement of the adjusting member due to the impact of the driving of the developing device in the case where the screwing is performed after the adjustment, such as the front adjusting mechanism.
Further, since the adjustment of the development gap PG on the rear side can be adjusted by the number of shims 231 mounted between the front plate 210 and the plate-like stay 230, the rear side is difficult to access in the operation of adjusting the development gap. Work is not required. Furthermore, the adjustment work for the front development gap PG and the adjustment work for the rear development gap PG can be performed by the operator only from the front side of the unit, and workability can be ensured. If the work is performed only from the front side of the unit, the work can be performed even in the state shown in FIG. 7, and the development gap PG can be adjusted and corrected on the printer 100 main body.

The image forming unit 200 of the present embodiment is effective as a system in which the developing device 4 is configured as a left stay member (fixed stay member) by fixing the developing device 4 to the two face plates (210, 220). However, the present invention is not limited to such a configuration. For example, the developing device 4 may not be fixed to the two face plates but may be provided with a left stay member. Further, the first span S1 on the plate-like stay 230 side that is the right stay member may be a fixed length, and an adjustment mechanism that adjusts the second span S2 that is the longitudinal length on the developing device 4 side may be provided. .
The image forming unit 200 is a process cartridge that integrally supports the developing device 4, the photoreceptor 1, the charging device 2, the cleaning device 6, and the charge eliminating unit. The image forming unit is not limited to such a configuration, and any configuration including at least the developing device 4 and the photoreceptor 1 may be used.

Further, in the image forming unit 200 of the present embodiment, a member that extends in the axial direction of the developing device 4 that functions as a fixed stay member and a plate-like stay 230 that is a stay member capable of adjusting the distance between the support surface plates are thermally expanded. It is made of a material with substantially the same coefficient.
FIG. 22 is an explanatory diagram of each component that is a stay member of the image forming unit 200. Among the components constituting the developing device 4, the front developing case 48, the rear developing case 49, the lower developing case 40, and the doctor blade holder 44 shown in FIG. 22 function as stay members. In the developing device 4, the lower developing case 40 and the doctor blade holder 44, which are members extending in the axial direction, are made of a material made of aluminum, and the plate-like stay 230 is made of a material made of aluminum. Specifically, the lower developing case 40 is made of aluminum die cast, and the plate-like stay 230 is made of an aluminum extruded material. The front developing case 48 and the rear developing case 49 are made of ABS resin. The doctor blade holder 44 is a member that supports the doctor blade 57.
The installation environment of the image forming unit 200 is subject to temperature changes such as the temperature difference between the temperature when the development gap PG is adjusted and the temperature when the printer 100 is operating, the temperature difference between the temperature when the printer operation is started and the temperature during continuous operation. Arise. For this reason, if the member extending in the axial direction of the developing device 4 and the plate-like stay 230 are made of materials having different thermal expansion coefficients, a gap between the developing device 4 and the plate-like stay 230 due to a temperature change is used. In addition, a dimensional difference in the stay direction occurs, and the inclination of the rear plate 220 with respect to the front plate 210 varies. When the inclination of the rear plate 220 with respect to the front plate 210 varies, the development gap PG also varies. Therefore, in the image forming unit 200 of this embodiment, the lower developing case 40 and the doctor blade holder 44 of the developing device 4, and the plate shape Since a component made of aluminum is used as the stay 230, it is possible to prevent a dimensional difference in the stay direction caused by a temperature change and to prevent the development gap PG from fluctuating.

Here, the occurrence of a dimensional difference in the stay direction due to a temperature change was compared between the case where the plate-like stay 230 was made of iron sheet metal (Fe) and the case where the plate-like stay 230 was made of aluminum extruded material (Al).
The length (span) of each member in the stay direction is shown in FIG.
Table 1 shows the variation of the span at the position where the lower developing case 40 is arranged, and Table 2 shows the variation of the span at the position where the doctor blade holder 44 is arranged.

  Moreover, Table 3 and Table 4 show the fluctuation | variation of the span in the position which arrange | positioned the plate-like stay 230, Table 3 shows the case where the plate-like stay 230 is iron, and Table 4 shows that the plate-like stay is made of aluminum. It is a table in the case of. The “case side” of the span deviation shown in Tables 3 and 4 is the span at the position where the lower developing case 40 shown in Table 1 is arranged.

FIG. 23 shows a graph of the total temperature change of the span at the position where the lower developing case 40 shown in Table 1 is arranged and the temperature change of the span of the plate stay 230 shown in Tables 3 and 4.
When applied to the characteristics of FIG. 15, as shown in the arrow H of 23 and Table 3, when the plate-like stay 230 made of iron sheet metal was used, the span deviation was about 211 [μm]. This difference corresponds to a state in which the development gap PG on the rear side varies by about 0.02 [mm].
On the other hand, as shown by the arrow I in FIG. 23 and Table 4, when the aluminum plate-like stay 230 is used, the span deviation is about 34 [μm], and the span deviation is larger than when using the iron one. The deviation can be greatly reduced, and therefore fluctuations in the rear development gap PG can be suppressed.

  Conventionally, when a stay member is provided separately from the developing device, an iron member is often used as the stay member. However, the temperature at which the image forming unit is arranged may vary from 30 [° C.] to 40 [° C.] depending on the usage environment and operating time. At this time, in the developing device 4 whose span length is determined by the parts made of ABS resin and the parts made of aluminum, and the iron plate-like stay 230, portions formed by respective stay members when the temperature rises. The change in elongation at is very different. In this case, the development gap PG may vary as much as 0.02 [mm] due to temperature changes. On the other hand, the span deviation can be reduced by using the plate-like stay 230 made of the same aluminum as the part extending in the longitudinal direction of the developing device 4 as in the image forming unit 200 of the present embodiment. Variations in the development gap PG due to temperature changes can also be suppressed.

FIG. 24 is an explanatory diagram of a fixing portion between the front plate 210 and the main body side plate 105 of the printer 100 main body. FIG. 24A is a cross-sectional view of the fixing portion as viewed from above, and FIG. These are the front views seen from the unit front side. FIG. 24A is an explanatory diagram of a state in which the first front plate fixing screw 106 and the second front plate fixing screw 107 are fixed. FIG. It is explanatory drawing of the state before fitting the 2nd front board fixing screw 107 in the fitting hole (106a, 107a) of the front board 210. FIG.
The fitting hole (106a) of the first front plate fixing screw 106 is formed by the first fixing hole forming member 106b, and a female screw is cut into the first face plate fixing stat 106c which is a fixing portion on the main body side plate 105 side. It is. Then, as shown in FIG. 24A, the first face plate fixing stat 106c is inserted into the first fixing hole forming member 106b, and the first front plate fixing screw 106 is inserted into the female screw of the first face plate fixing stat 106c. By screwing, the fitting hole (106a) side of the first front plate fixing screw 106 can be fixed to the main body side plate 105. Further, the second front plate fixing screw 107 can be similarly fixed to the main body side plate 105 by the second fixing hole forming member 107b and the second face plate fixing stat 107c on the fitting hole (107a) side.
Since the front plate 210 is screwed to the main body side plate 105 in this way, the axial direction of the rotation axis of the photosensitive member 1 and the developing roller 41 and the direction orthogonal to the axial direction are attached to the printer 100 main body. Positioning is performed with respect to it.

On the other hand, as shown in FIG. 12, the rear plate 220 does not include a fitting hole for screw fixing to the printer 100 main body, but the printer 100 main body side when the image forming unit 200 is mounted on the printer 100 main body. A projection 224 that fits into a fitting hole (not shown) is provided. By fitting the protrusion 224 into the fitting hole on the printer 100 main body side, the rear plate 220 is positioned with respect to the printer 100 main body in the direction perpendicular to the axial direction of the rotation shaft. However, since only the protrusion is inserted into the fitting portion, the rear plate 220 is not positioned with respect to the main body of the printer 100 in the axial direction of the rotation shaft. For this reason, in a state where the image forming unit 200 is disposed with respect to the printer 100 main body, the rear plate 220 can be displaced in the axial direction of the rotation axis with respect to the printer 100 main body. Note that this is a secondary reference in the rotation direction of the image forming unit 200 of the protrusion 224, and the main reference in this rotation direction is the rotation axis of the photoreceptor 1.
The image forming unit 200 of this embodiment changes the inclination of the rear plate 220 with respect to the front plate 210 by displacing the position of the portion of the rear plate 220 to which the plate-like stay 230 is fixed, and sets the first span S1. In this configuration, the development gap PG is adjusted by changing.
With such a configuration, when the rear plate 220 is positioned with respect to the printer 100 body in the axial direction, the printer 100 body side interferes with the change in the first span S1. When the image forming unit 200 is mounted on the printer 100 main body after adjusting the development gap GP, the development gap PG adjusted by the unit alone may fluctuate due to interference from the printer 100 main body side. On the other hand, if the rear plate 220 is not positioned with respect to the printer 100 main body in the axial direction as in the present embodiment, the printer 100 main body side interferes with the change in the first span S1. It is possible to prevent the influence and to prevent the development gap PG adjusted by a single unit from fluctuating due to installation in the printer 100 main body.

Next, a characteristic shape of the rear plate 220 will be described. FIG. 25 is a front view of the rear plate 220 when the rear plate 220 is viewed from the front side of the unit.
The rear plate 220 is fixed to the plate-like stay 230 by being screwed with two screws (first stay rear screw 933 and second stay rear screw 934). The shape of the rear plate 220 at the position where the plate-like stay 230 is fixed is a peninsular shape as shown in FIG. That is, the portion provided with the first rear surface stay screw fitting hole 933a that is screwed by the first stay rear surface screw 933 is the second rear surface stay screw fitting hole that is screwed by the second stay rear surface screw 934. Only the portion provided with 934a is connected to the other portion of the rear plate 220, and the other three directions other than the portion provided with the second rear stay screw fitting hole 934a are in a free state.
By adopting such a peninsula shape, the bending strength of the rear plate 220 is reduced from the position of the second rear stay screw fitting hole 934a located at the base of the peninsula shape to the position of the first rear stay screw fitting hole 933a. Can do. That is, among the fixed portions of the rear plate 220 fixed to the plate-like stay 230 by the two fixed portions, the position of the other fixed portion from the position of the fixed portion closer to the developing device 4 that is the fixed stay. The bending strength of the rear plate 220 up to this point can be reduced.

Here, the advantage of weakening the bending strength between the two fixing portions will be described.
FIG. 26 is an explanatory view schematically showing the deformation of the rear plate 220 when the adjustment is performed so that the first span S1 is widened. FIG. 26 (a) is an explanatory view before deformation, FIG. 26 (b) is an explanatory view when the first span S1 expands in a configuration in which the bending strength between the two fixing portions is not weakened, and FIG. 26 (c) is an explanatory diagram when the first span S1 is expanded with a configuration in which the bending strength between the two fixed portions is weakened.
When the bending strength between the two fixing portions is the same as that of the other portions, the rear plate 220 swells to the rear side of the unit as shown in FIG. 26 (b) due to the rigidity of the rear plate 220. As a result, it becomes impossible to ensure the formation of the deformation line of the rear plate 220 with respect to the change of the first span S1. For this reason, it becomes difficult to adjust the inclination of the rear plate 220 with respect to the front plate 210 to a desired inclination.
On the other hand, in the case of a configuration in which the bending strength between the two fixing portions is weakened, as shown in FIG. Can be deformed, and it is possible to ensure the formation of a deformation line of the rear plate 220 with respect to the change of the first span S1. Thereby, the inclination of the rear surface plate 220 with respect to the front surface plate 210 can be adjusted to a desired inclination.
In order to obtain such advantages, it is conceivable to fix the plate stay 230 and the rear plate 220 at one point. However, if the fixing position with respect to the rear plate 220 is one point, the first span S1 is changed. Thus, when a force is applied to the rear plate 220, the rear plate 220 is likely to be deformed in the twisting direction with respect to the front plate 210. On the other hand, by fixing the plate-like stay 230 and the rear plate 220 at a plurality of fixing positions at two or more locations, the strength in the twisting direction is secured, and the rear plate 220 is prevented from being deformed in the twisting direction. be able to.

In FIG. 25, a one-dot chain line La is a straight line connecting the rotation center of the upper developing roller 411 and the rotation center of the photosensitive member 1, and a one-dot chain line Lb is a rotation center of the lower developing roller 412 and the rotation center of the photosensitive member 1. Is a straight line connecting An alternate long and short dash line La is a straight line connecting a midpoint between the rotation center of the upper developing roller 411 and the rotation center of the lower developing roller 412 and the rotation center of the photosensitive member 1.
In the image forming unit 200, the position of the second rear surface stay screw fitting hole 934 a, which is a screwed position close to the developing device 4 that is a fixed stay among the two screw positions, is indicated by a one-dot chain line La or one-dot chain line on the rear plate 220. It is desirable to be positioned on or near the straight line indicated by Lb. In the image forming unit 200 of the present embodiment, the second rear surface stay screw fitting hole 934a is disposed in the vicinity of a straight line indicated by a one-dot chain line La passing through the rotation center of the upper developing roller 411.
By disposing the rear plate 220 in the direction close to the line connecting the developing roller 41 and the photosensitive member 1 in this way, even if the displacement of the same development gap PG is the same, the rear plate 220 The amount of deformation can be reduced. In other words, since the rear plate 220 is deformed in a direction that effectively acts on the change in the development gap PG, it is possible to suppress distortion of the installation positions of the respective members that may be caused by the bending of the rear plate 220.

  Further, the image forming unit 200 includes a second rear surface stay screw fitting hole on or near the straight line indicated by the alternate long and short dash line Lm connecting the midpoint of the rotation centers of the two developing rollers 41 and the photosensitive member 1. An arrangement in which 934a is located may be employed. As a result, the rear plate 220 can be deformed in a direction in which the development gap PG on the rear side between the upper developing roller 411 and the lower developing roller 412 is changed substantially uniformly.

Further, as shown in FIG. 24B, the front plate 210 has a first front plate fixing screw 106 and a second front plate fixing screw 107 with respect to the main body side plate 105 of the printer 100 main body to which the image forming unit 200 is mounted. Fixing is performed using the positions of the fitting holes (106a, 107a) as fixing portions. These two fixing portions are arranged in the vicinity of the upper end portion of the front plate 210, whereas the fixing position of the plate-like stay 230 is arranged in the vicinity of the lower end portion of the front plate 210. For this reason, the fixing position of the front plate 210 with respect to the main body of the printer 100 and the fixing position with respect to the plate-like stay 230 can be arranged at separate positions.
As shown in FIG. 24A, the two fixing hole forming members (106b and 107b) of the front plate 210 with respect to the printer 100 main body are arranged on the main body side plate 105 of the printer 100 main body, and the first face plate fixing stat 106c and The second face plate fixing stat 107c is fitted and fixed to the step faces of the first face plate fixing stat 106c and the second face plate fixing stat 107c by abutment. At this time, it is difficult to accurately match the positions of the first face plate fixing stat 106c and the second face plate fixing stat 107c with the two fixing positions on the front face plate 210 side with high accuracy.
For this reason, a certain amount of error occurs, but when an error occurs, the error is absorbed by the deformation of the front plate 210, not the main body side plate 105 of the printer 100 main body. Further, when there is a variation in the size of the main body side plate 105 in the mounting direction of the image forming unit 200, when the image forming unit 200 is set, the perpendicularity of the front plate 210 with respect to the rotation axis of the photoreceptor 1 changes.
If the deformation of the front plate 210 at this time affects the fixed position with respect to the plate-like stay 230, the deformation of the front plate 210 may affect the development gap PG on the rear side adjusted by adjusting the first span S1. is there. On the other hand, in the image forming unit 200, the fixing position of the front plate 210 with respect to the main body of the printer 100 and the fixing position with respect to the plate-like stay 230 are arranged at separate positions. Therefore, even if the front plate 210 is deformed due to the fixing to the printer 100 main body, the deformation is almost absorbed by the front plate 210 between the fixing position with respect to the printer 100 main body and the fixing position with respect to the plate-like stay 230. The amount of displacement of the front plate 210 at the fixing portion of the plate-like stay 230 can be suppressed. Thereby, it is possible to prevent the deformation of the front plate 210 from affecting the development gap PG on the rear side adjusted by adjusting the first span S1 via the plate-like stay 230.

  Moreover, you may comprise so that the bending strength of the front plate 210 in the vicinity of at least one fixed part among the two fixed parts with respect to the printer 100 main body of the front plate 210 may become weak. Specifically, the hatched portion J in FIG. 24C is notched or the hatched portion K is not bent. Thereby, the fitting hole (106a) of the first front plate fixing screw 106 can weaken the bending strength in the vicinity, and even if the front plate 210 is deformed due to fixing to the printer 100 main body, this bending strength is reduced. A weak part mainly deform | transforms and can suppress the displacement amount of the front board 210 in the fixing | fixed part of the plate-like stay 230. FIG.

  In the image forming unit 200, the plate stay 230 is fixed to each of the front plate 210 and the rear plate 220 at two fixed positions, but the adjustment of the first span S1 by the shim 231 is one. The shim 231 is simultaneously adjusting the two fixed positions. The adjustment of the first span S1 by the spacer member is not limited to adjusting the two fixed positions at the same time, and may be performed independently. That is, it is the structure which changes the mounting number of a spacer member independently with respect to each of two fixed positions. By independently adjusting the first spans S1 at the two fixed positions, the inclination of the torsional direction of the rear plate 220 with respect to the front plate 210, so-called tilt, can be adjusted. In this case, the two fixed positions of the plate-like stay 230 are arranged side by side as indicated by 243a and 243b in FIG.

[Modification 1]
Next, a first modification example (hereinafter referred to as modification example 1) in which the development gap PG is adjusted by changing the first span S1 of the image forming unit 200 of the present embodiment will be described.
FIG. 27 is a schematic top view of the image forming unit 200 of the first modification.
The image forming unit 200 of Modification 1 is different in that a bar-like stay 240 is provided instead of the plate-like stay 230 of the image forming unit 200 shown in FIG. Since other configurations are common, description thereof is omitted.
As shown in FIG. 27, the rod-like stay 240 included in the image forming unit 200 according to Modification 1 includes a male screw portion 241. The rod-like stay 240 and the rear plate 220 are screw-fixed by a rod-like stay fixing screw 243, and the rod-like stay 240 and the front plate 210 are two nuts 242 attached to the male screw portion 241 before and after the front plate 210. The front plate 210 is pinched by (242a, 242b) to be fixed.
In the image forming unit 200 of the first modification, by rotating the nut 242, the protruding amount of the male screw portion 241 with respect to the front plate 210 changes, and the first span S <b> 1 can be changed. By changing the first span S1, the rear development gap PG can be adjusted by adjusting the first span S1, as in the image forming unit 200 described with reference to FIG.

FIG. 28 is a perspective explanatory view of the image forming unit 200 of the first modification as viewed from the rear side of the unit, and FIG. 29 is a front view of the rear panel 220 of the rear panel 220 of the first modification viewed from the front side of the unit. .
As shown in FIG. 28, the image forming unit 200 according to the first modification includes two first stays 240a and second stays 240b as stays 240 that are stay members that can adjust the distance between the support face plates. The first bar-like stay 240a and the second bar-like stay 240b are configured such that the first span S1, which is the distance from the front plate 210 to the rear plate 220, can be adjusted independently of each other. Specifically, since the first rod-like stay 240a and the second rod-like stay 240b are provided with the male screw portion 241 and the nut 242 described with reference to FIG. 27 as shown in FIG. 28, two nuts (242a, By rotating 242b) independently, the protruding amounts of the first male screw portion 241a and the second male screw portion 241b with respect to the front plate 210 can be adjusted independently.

In FIG. 29, reference numerals 244a and 244b denote fitting holes for the first rod-like stay fixing screw 243a and the second rod-like stay fixing screw 243b. The fixed position is shown.
Also, as shown in FIG. 29, the fixed position of the first rod-like stay 240a with respect to the rear plate 220 is in the vicinity of the alternate long and short dash line Lb in FIG. It is arranged to become. Further, the fixing position of the second rod-like stay 240b with respect to the rear plate 220 is arranged to be in the vicinity of an alternate long and short dash line La in FIG. . Also, as shown in FIG. 29, the two fixed positions are shown in FIG. 29 passing through the midpoint between the rotation center of the upper developing roller 411 and the rotation center of the lower developing roller 412 and the rotation center of the photosensitive member 1. Arranged in the vicinity of a straight line indicated by a one-dot chain line Ln orthogonal to the one-dot chain line Lm. By independently adjusting the first span S1 at the two fixed positions arranged in this way, the deformation direction (tilting direction) of the rear plate 220 is controlled, and the rear side development gap PG of the upper and lower developing rollers 41 is controlled. Adjust the balance.

Further, in the case of the configuration in which the number of spacer members attached is changed independently for each of the two fixed positions of the plate-like stay 230 described above, a plate is used instead of the two rod-like stays (240a, 240b) in FIG. A state stay 230 is arranged. Then, instead of rotating the two nuts (242a, 242b), the first span S1 is adjusted by adjusting the number of shims that are spacer members between the plate-like stay 230 and the rear plate 220. I can do it. Similarly to the configuration in which the two nuts (242a, 242b) are rotated independently, the plate-like stay 230 is used by independently adjusting the number of shims at the two fixed positions. Can also adjust so-called tilt.
In the case where two fixed positions of one plate-like stay 230 are arranged in the vertical direction and the number of spacer members attached is changed independently for each of the two fixed positions, It is desirable to sandwich a spacer member with the rear plate 220. This is because if a different number of spacer members are sandwiched on the front plate 210 side, the plate-like stay 230 is deformed into a twisted state, and the desired tilt adjustment may not be performed.

In the image forming unit 200 of the present embodiment, the configuration in which one developing device 4 includes the two developing rollers 41 has been described. However, the characteristic part of the present invention is an image forming unit in which one developing device includes one developing roller. It is applicable to.
In the case of a configuration in which one developing roller is provided for one developing device, the first span is on or near the straight line connecting the rotation center of the developing roller and the rotation center of the photosensitive member. It is desirable to provide a fixed position for the member that adjusts S1.
In this embodiment, as a roller device including a plurality of roller members arranged so that the rotation axes are parallel, an image forming device (image forming unit 200) in which the plurality of roller members are the photosensitive member 1 and the developing roller 41. However, the roller device that adjusts the distance between the rollers by changing the inclination of the second support surface plate with respect to the first support surface plate is not limited to the image forming device. Examples of the combination of the two roller members constituting the roller device include, but are not limited to, a photoreceptor and a charging roller, a conveying roller pair, and a roller pair forming a fixing nip of the fixing device.

  As described above, the image forming unit 200 as the image forming apparatus of the present embodiment forms a development gap between the photosensitive member 1 and the surface of the photosensitive member 1, and develops the latent image on the photosensitive member 1. And a developing device 4 including a roller 41. Further, the front plate 210 which is a first supporting face plate that supports one end of the rotating shaft of the photosensitive member 1 in the axial direction and one end of the rotating shaft of the developing roller 41 in the axial direction, and the photosensitive member 1 and the developing roller 41 are sandwiched. A rear plate 220 which is a second support face plate disposed opposite to the front plate 210 and supporting the other axial end of the rotating shaft of the photoreceptor 1 and the other axial end of the rotating shaft of the developing roller 41. Have. The image forming unit 200 adjusts the development gap GP by changing the inclination of the rear plate 220 with respect to the front plate 210. In this manner, by adjusting the development gap GP, the development gap GP can be adjusted without displacing the positions of the rotation shaft of the photosensitive member 1 and the rotation shaft of the developing roller 41 with respect to the rear plate 220 that is the support face plate. it can.

  The image forming unit 200 extends in the axial direction of the rotation axis, and both end portions in the axial direction are fixed to the front plate 210 and the rear plate 220, respectively. The developing device 4 and the plate-like stay 230 are provided as a plurality of stay members that determine the distance in the direction. By changing the distance between the front plate 210 and the rear plate 220 at the position where the plate-like stay 230 which is a part of the plurality of stay members is fixed, the inclination of the rear plate 220 with respect to the front plate 210 is changed. Let Thereby, the inclination of the rear surface plate 220 with respect to the front surface plate 210 can be changed with a simple configuration.

  The image forming unit 200 includes, as a plurality of stay members, a developing device 4 that is a fixed stay member whose positions with respect to the front plate 210 and the rear plate 220 are fixed, and the front plate 210 to the rear plate 220 at fixed positions. And a plate-like stay 230 which is a stay member capable of adjusting the distance between the support face plates, the distance of which is adjustable. Thereby, the inclination with respect to the front plate 210 of the rear plate 220 can be adjusted by adjusting the distance between the front plate 210 and the rear plate 220 on the plate-like stay 230 side.

  Further, by changing the number of shims 231 that are detachable spacer members between the front plate 210 and the plate-like stay 230, the front plate 210 and the rear plate 220 between the positions where the plate-like stay 230 is fixed are changed. The first span S1, which is the distance, is changed. With such a configuration, the development gap PG can be adjusted with a simple configuration in which the shim 231 is increased or decreased.

  In addition, the image forming unit 200 according to the first modification includes a developing device 4 that is a fixed stay member that is fixed with respect to the front plate 210 and the rear plate 220 as a plurality of stay members, and a front plate 210 that is fixed. A bar-like stay 240, which is a stay member capable of adjusting the distance between the support face plates, is configured so that the distance to the rear face plate 220 is adjustable. Then, by adjusting the length of the rod-like stay 240, the first span S1 that is the distance between the front plate 210 and the rear plate 220 at the position where the rod-like stay 240 is fixed is changed. With such a configuration, the development gap PG can be adjusted with a simple configuration of adjusting the length of the rod-like stay 240.

  In addition, the image forming unit 200 includes a plate-shaped stay that is a member that can be adjusted in the axial direction of the developing device 4 (the lower developing case 40, the doctor blade holder 44) that is a fixed stay member, and a support member that can adjust the distance between the support surface plates. 230 is made of aluminum. Since the same material is used, the thermal expansion coefficients of the member extending in the axial direction of the developing device 4 and the plate-like stay 230 are equal, and the temperature changes between the developing device 4 side and the plate-like stay 230 side. It is possible to prevent the resulting dimensional difference in the stay direction and to prevent the development gap PG from fluctuating.

  The inclination of the rear plate 220 with respect to the front plate 210 of the image forming unit 200 is adjusted by displacing the position of the rear plate 220 with respect to the front plate 210 at the position where the plate-like stay 230 is fixed. The plate-like stay 230 is fixed by screwing with two screws. The shape of the rear plate 220 at the position where the plate-like stay 230 is fixed is a peninsular shape as shown in FIG. By adopting such a peninsula shape, the rear plate 220 extends from the position of the second rear stay screw fitting hole 934a located at the base of the peninsula shape to the position of the first rear stay screw fitting hole 933a located at the tip of the peninsula shape. The bending strength of can be reduced. Accordingly, the rear plate 220 can be deformed as if a load is applied to one point of the position of the second rear stay screw fitting hole 934a, and the deformation of the rear plate 220 with respect to the change of the first span S1 is ensured. be able to.

  Further, in the image forming unit 200, the position of the second rear surface stay screw fitting hole 934 a which is a screwing position close to the developing device 4 which is a fixed stay among the two screwing positions is the upper developing roller 411 on the rear plate 220. It arrange | positions so that it may be located in the vicinity of the straight line shown with the dashed-dotted line La which passes through the rotation center. As a result, the rear plate 220 can be deformed in a direction close to the line connecting the developing roller 41 and the photosensitive member 1, and the deformation amount of the rear plate 220 can be reduced even with the same development gap PG displacement. Can be reduced.

  Further, in the image forming unit 200, the rear plate 220 and the plate-like stay 230 are fixed by screwing with a plurality of screws, and the developing device 4 includes the upper developing roller 411 and the lower developing roller as two developing rollers 41. 412. Of the two screwing positions, the position of the second rear surface stay screw fitting hole 934a, which is the screwing position near the developing device 4 that is the fixed stay, is the center of rotation of the two developing rollers 41 on the rear plate 220. You may arrange | position so that it may be located on the straight line shown by the dashed-dotted line Lm which connects a point and the rotation center of the photoreceptor 1, or the vicinity of the straight line. As a result, the rear plate 220 can be deformed in a direction in which the development gap PG on the rear side between the upper developing roller 411 and the lower developing roller 412 is changed substantially uniformly.

  In addition, the image forming unit 200 according to the first modification includes two support face plate adjustable stay members, ie, a first rod-like stay 240a and a second rod-like stay 240b. And the 1st rod-like stay 240a and the 2nd rod-like stay 240b are adjusted from the front plate 210 by adjusting the protrusion amount of the 1st male screw part 241a and the 2nd male screw part 241b with respect to the front board 210 each independently. The first span S1, which is the distance to the rear plate 220, can be adjusted independently of each other. The two fixed positions of the first rod-like stay 240 a and the second rod-like stay 240 b on the rear plate 220 are the midpoint between the rotation center of the upper developing roller 411 and the rotation center of the lower developing roller 412, and the rotation center of the photoreceptor 1. Are arranged in the vicinity of a straight line indicated by a one-dot chain line Ln orthogonal to the one-dot chain line Lm passing through. By independently adjusting the first span S1 at the two fixed positions arranged in this way, the deformation direction (tilting direction) of the rear plate 220 is controlled, and the rear side development gap PG of the upper and lower developing rollers 41 is controlled. Adjust the balance.

  The front plate 210 is provided with fitting holes (106a, 107a) as fixing parts to be fixed to the main body of the printer 100 in which the image forming unit 200 is arranged, and the fixing positions of the two fitting holes and the plate-like stay 230 are determined. It is arranged so as to be separated from each other. Thereby, even if it is a case where the variation of the front plate 210 and the main body side plate 105 is absorbed by the deformation | transformation of the front plate 210, the displacement amount of the front plate 210 in the fixing | fixed part of the plate-like stay 230 can be suppressed. Therefore, it is possible to prevent the deformation of the front plate 210 from affecting the rear development gap PG adjusted by adjusting the first span S1 via the plate stay 230.

  Further, there are two fixing portions of the front plate 210 to the printer 100 main body, and the bending strength of the front plate 210 in the vicinity of at least one of the two fixing portions may be reduced. As a result, even if the front plate 210 is deformed due to the fixing to the printer 100 main body, the portion where the bending strength is weak is mainly deformed, and the amount of displacement of the front plate 210 at the fixing portion of the plate-like stay 230 is suppressed. be able to.

  The image forming unit 200 includes a front plate 210 and a rear plate 220 between a fixed portion of the developing device 4 that is a fixed stay member and a fixed portion of the plate-like stay 230 that is a stay member that can adjust the distance between the support surface plates. A photosensitive member bearing 12 and a second photosensitive member bearing 14 which are positioning mechanisms of the photosensitive member 1 with respect to the photosensitive member 1 are disposed. Thereby, the position of the photosensitive member bearing 12 with respect to the developing device 4 is displaced by the displacement of the fixing position of the plate-like stay 230 on the front plate 210. Therefore, the position of the photosensitive member 1 with respect to the developing roller 41 changes, and the developing gap PG can be adjusted.

  Further, by fixing the developing device 4 to the front plate 210 and the rear plate 220, the developing device 4 also functions as a fixed stay member. Thereby, it is not necessary to provide a fixed stay member separately, and space can be used effectively.

  The photosensitive member positioning mechanism for positioning the photosensitive member 1 with respect to each of the front plate 210 and the rear plate 220 is a rotation support member that rotatably supports the photosensitive member 1 with respect to the front plate 210 and the rear plate 220. A certain photosensitive member bearing member (the photosensitive member bearing 12 and the second photosensitive member bearing 14) is provided. Of the photosensitive member bearing members, the photosensitive member bearings 12 are arranged such that their positions in the axial direction are offset with respect to the rear plate 220. As a result, the amount of displacement of the photoconductor bearing 12 with respect to the deformation of the rear plate 220 is increased.

  In the image forming unit 200, the displacement amount of the photosensitive member bearing member (the photosensitive member bearing 12 and the second photosensitive member bearing 14) when the inclination of the rear plate 220 with respect to the front plate 210 is changed is the second photosensitive member bearing. The photosensitive member bearing 12 is larger than the photosensitive member bearing 14. Thereby, when the first span S1 is changed, the photosensitive member bearing 12 can be mainly displaced, and the displacement of the second photosensitive member bearing 14 can be suppressed.

  Further, the image forming unit 200 includes a second photosensitive member bearing 14 disposed on the front plate 210 and a photosensitive member bearing 12 disposed on the rear plate 220, and is offset from the supporting surface plate on which the photosensitive member member is disposed. The amount is configured to be different. Due to the difference in the offset amount of the photosensitive member bearing member with respect to the support face plate, the displacement amount of the photosensitive member bearing member when the inclination of the rear plate 220 with respect to the front plate 210 is changed causes the second photosensitive member bearing 14 and the photosensitive member bearing 12 to change. And can be configured differently. Specifically, by increasing the offset amount of the photosensitive member bearing 12, when the first span S1 is changed, the photosensitive member bearing 12 can be mainly displaced, and the displacement of the second photosensitive member bearing 14 is reduced. Can be suppressed.

  Further, the image forming unit 200 is bent in a direction on a straight line connecting the rotation center of the developing roller 41 (midpoint of the rotation centers of the two developing rollers) and the rotation center of the photosensitive member 1 on the front plate 210 and the rear plate 220. The strength differs between the front plate 210 and the rear plate 220. Since the bending strength is different, the displacement amount of the photosensitive member bearing member when the inclination of the rear plate 220 with respect to the front plate 210 is changed can be configured to be different between the second photosensitive member bearing 14 and the photosensitive member bearing 12. Specifically, by making the bending strength of the rear plate 220 weaker than that of the front plate 210, the photoconductor bearing 12 can be mainly displaced when the first span S1 is changed, and the second photoconductor bearing. 14 displacement can be suppressed.

  Further, the image forming unit 200 has a developing roller 41 on the front plate 210 on the front plate 210 which is a support surface plate on the side where the displacement amount of the photosensitive member bearing member when the inclination of the rear plate 220 with respect to the front plate 210 is changed. An eccentric holder 45 that is a developing roller position adjusting mechanism that adjusts a position for supporting the second developing roller shaft 43b is provided. Thus, by changing the first span S1, the front development gap GP can be adjusted to match the adjusted rear development gap GP.

  The image forming unit 200 includes an upper eccentric holder 451 and a lower eccentric holder 452 as independent developing roller position adjusting mechanisms for the two developing rollers 41 (upper developing roller 411 and lower developing roller 412). Have. As a result, the two developing rollers 41 are independently adjusted in accordance with the rear development gap PG to adjust the front development gap PG, thereby improving the tolerance of the development gap PG in a narrow setting range and the development gap PG. It becomes possible to achieve both improvement in front and rear deviation.

  Further, the image forming unit 200 drives the developing roller 41 to the rear plate 220 side which is the support surface plate on the side where the displacement amount of the photosensitive member bearing member when the inclination of the rear plate 220 with respect to the front plate 210 is changed. A developing roller driving mechanism (not shown) for transmitting is provided. Even if the developing gap PG is adjusted, the position of the first developing roller shaft 43a, which is the rotation shaft of the developing roller 41, does not change on the rear plate 220 side, so that the developing roller driving mechanism such as a driving gear is not changed. It is possible to prevent the position of the first developing roller shaft 43a from changing and the adjustment of the developing gap PG from affecting the drive transmission.

  In addition, the image forming unit 200 serves as a support face plate inclination adjusting means that determines the distance between the front plate 210 and the rear plate 220 at the position where the plate stay 230 that is one of the two stay members is fixed. A support face plate distance adjusting means for adjusting is provided. Further, as the distance adjustment means between the support surface plates, a shim 231 as a spacer member is detachable between the front plate 210 and the plate-like stay 230, and the number of the shim 231 is changed to change the plate-like stay. The first span S1, which is the distance between the front plate 210 and the rear plate 220 at the position where 230 is fixed, can be adjusted. Then, the mounting position of the shim 231 that is the operation position of the support surface inter-plate inclination adjusting means is the support on the side of the front plate 210 or the rear plate 220 that is easily accessible when the image forming unit 200 is arranged in the printer 100 main body. It arrange | positions at the front plate 210 which is a face plate. Further, the front plate 210 provided with the mounting position of the shim 231 is a support surface plate on the side where the displacement amount of the photosensitive member bearing member is smaller than that of the rear plate 220 when the inclination of the rear plate 220 with respect to the front plate 210 is changed. is there. That is, in the image forming unit 200, it is possible to perform an operation of adjusting the deformation of the rear plate 220 on the front plate 210 side, not on the rear plate 220 side which is mainly deformed by changing the first span S1.

  In the present embodiment, the image forming unit 200 including at least the photosensitive member 1 and the developing device 4 that is a developing unit is a process cartridge that can be attached to and detached from the main body of the printer 100, thereby forming the image forming unit 200 alone. With the adjustment of the development gap PG, the image forming unit 200 can be set in the printer 100 main body.

  In addition, since the printer 100 includes the image forming unit 200 as the image forming unit, the image can be formed by the image forming unit in which the development gap PG is appropriately adjusted. Therefore, good image formation can be realized. it can.

  Further, in a state where the image forming unit 200 is disposed on the printer 100 main body, the rear plate 220 is not positioned with respect to the printer 100 main body in the axial direction (attachment direction) of the rotation shaft, and can be displaced. In this way, if the rear plate 220 is configured to be not positioned with respect to the printer 100 main body in the axial direction, the influence of the printer 100 main body side interfering with the change in the first span S1 can be prevented. It is possible to prevent the development gap PG adjusted by a single unit from fluctuating due to installation in the printer 100 main body.

Explanatory drawing of the roller apparatus which concerns on this invention. Explanatory drawing of the other example of the roller apparatus which concerns on this invention. 1 is a schematic configuration diagram of a printer according to an embodiment. FIG. 3 is a schematic sectional view of an image forming unit. FIG. 3A is a perspective explanatory view of the image forming unit, FIG. 3A is a perspective explanatory view seen from the rear side of the unit, and FIG. FIG. 2 is a schematic top view of an image forming unit. FIG. 3 is an explanatory perspective view of the printer with one of the image forming units pulled out. FIG. 6 is an explanatory perspective view of a state where a photoconductor is removed from the image forming unit shown in FIG. 5. FIG. 6 is an explanatory perspective view of a state in which each member is removed from the front plate and the rear plate of the image forming unit shown in FIG. 5. FIG. 9 is an explanatory perspective view of a state in which each member is removed from the front plate and the rear plate of the image forming unit shown in FIG. 8. Explanatory drawing of a front plate, (a) is the perspective explanatory drawing seen from the unit rear side, (b) is the perspective explanatory drawing seen from the unit front side. Explanatory drawing of a rear surface board, (a) is the perspective explanatory drawing seen from the unit rear side, (b) is the perspective explanatory drawing seen from the unit front side. Expansive explanatory drawing of the fixing | fixed part vicinity of the front plate and plate-shaped stay before mounting | wearing with a shim. The expansion explanatory view near the fixed part of the front plate and plate-like stay after mounting a shim. The graph which shows the measurement of the change of the development gap with respect to the number of shims attached. Explanatory drawing of the front plate of a structure which is not provided with an eccentric holder. Explanatory drawing of the front plate of a structure provided with an eccentric holder. The perspective explanatory drawing of an eccentric holder, (a) is the perspective view seen from the unit rear side, (b) is the perspective view seen from the unit front side. Explanatory drawing of the structure which adjusts the development gap of the front side with an eccentric holder. The graph which shows the measurement of the change of the development gap with respect to the rotation angle of an upper eccentric holder. The graph which shows the measurement of the change of the development gap with respect to the rotation angle of a lower eccentric holder. Explanatory drawing of each component used as the stay member of an image forming unit. The graph which shows the temperature change of the span of each stay member. Explanatory drawing of the fixing | fixed part of a front plate and the main body side plate of a printer main body, (a) is sectional drawing which looked at the fixing | fixed part from upper direction, (b) is the front view which looked at the fixing | fixed part from the unit front side. The front view of the rear board seen from the unit front side. Explanatory drawing which showed typically the deformation | transformation of the rear surface board with respect to adjustment of a 1st span. FIG. 6 is a schematic top view of an image forming unit of a first modification. FIG. 9 is a perspective explanatory view of an image forming unit of Modification 1; The front view of the rear surface board of the modification 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Charging device 3 Optical writing device 4 Developing device 5 Primary transfer charger 6 Cleaning device 7 Intermediate transfer belt 8 Secondary transfer roller 9 Roller device 10 Image forming process part 13a First photoconductor shaft 13b Second photoconductor shaft 40 Lower developing case 41 Developing roller 42 Developing roller bearing 44 Doctor blade holder 45 Eccentric holder 48 Front developing case 49 Rear developing case 60 First roller 61 Second roller 62 Second roller bearing 63 Second roller shaft 64 First roller bearing 65 First roller shaft 70 Transfer unit 71 Secondary transfer counter roller 81 Registration roller pair 91 First support surface plate 92 Second support surface plate 100 Printer 105 Main body side plate 113 Photoconductor drive shaft 200 Image forming unit 210 Front plate 220 Rear plate 230 Plate shape Stay 231 Shim 240 Bar-like stay 241 Male thread 242 Nut 43 rod-like stays fixed screw S1 first span S2 second span

Claims (35)

A plurality of roller members arranged such that their rotation axes are parallel;
A first support face plate for supporting axial ends of the plurality of roller members;
The plurality of roller members of the roller device having a second support surface plate disposed opposite to the first support surface plate with the plurality of roller members interposed therebetween and supporting the other axial end of the plurality of roller members. In the inter-roller distance adjustment method for adjusting the inter-roller distance, which is the distance between the rotation centers of the two roller members,
An inter-roller distance adjusting method comprising adjusting an inter-roller distance by changing an inclination of the second support face plate with respect to the first support face plate. In the roller distance adjustment method of Claim 1,
It extends in the axial direction, and both ends in the axial direction are fixed to the first support face plate and the second support face plate, respectively, and the axial direction of the first support face plate and the second support face plate is about With multiple stay members that determine the distance,
The second support face plate with respect to the first support face plate by changing a distance between the first support face plate and the second support face plate at a position where some of the stay members are fixed. A method for adjusting the distance between rollers, wherein the inclination of the roller is changed. In the roller distance adjustment method of Claim 2,
The roller device includes, as the plurality of stay members, a fixed stay member fixed in position with respect to the first support surface plate and the second support surface plate, and the second support surface plate from the first support surface plate in the fixed position. And a stay member that can adjust the distance between the support face plates, the distance of which can be adjusted,
By changing the number of detachable spacer members between at least one of the first support face plate and the second support face plate and the stay member capable of adjusting the distance between the support face plates,
A distance adjustment method between rollers, wherein a distance between the first support surface plate and the second support surface plate at a position where the stay member capable of adjusting the distance between the support surface plates is fixed is changed. In the roller distance adjustment method of Claim 2,
The roller device includes, as the plurality of stay members, a fixed stay member fixed in position with respect to the first support surface plate and the second support surface plate, and the second support surface plate from the first support surface plate in the fixed position. A support member that can adjust the distance to the support face plate,
By adjusting the length of the stay member capable of adjusting the distance between the support face plates,
A distance adjustment method between rollers, wherein a distance between the first support surface plate and the second support surface plate at a position where the stay member capable of adjusting the distance between the support surface plates is fixed is changed. A photoreceptor,
A developing gap adjustment for adjusting the developing gap of the image forming apparatus including a developing device including a developing roller that develops a latent image on the photosensitive member with a surface forming a developing gap between the surface and the surface of the photosensitive member. In the method
The image forming apparatus is a roller apparatus including the photosensitive member and the developing roller as the two roller members, and adjusts the developing gap by the inter-roller distance adjusting method according to any one of claims 1 to 4. A development gap adjusting method characterized by the above. A plurality of roller members arranged such that their rotation axes are parallel;
A first support face plate for supporting axial ends of the plurality of roller members;
In a roller device having a second support surface plate disposed opposite to the first support surface plate with the plurality of roller members interposed therebetween, and supporting the other end in the axial direction of the plurality of roller members,
A support face plate inclination adjusting means for adjusting the inclination of the second support face plate with respect to the first support face plate;
The inter-roller distance, which is the distance between the rotation centers of two of the plurality of roller members, by changing the inclination of the second support surface plate with respect to the first support surface plate by the inter-support surface plate inclination adjusting means. A roller device characterized by adjusting the pressure. The roller device according to claim 6, wherein
Extending in the axial direction of the rotating shaft, both ends in the axial direction are fixed to the first supporting face plate and the second supporting face plate, respectively, and the rotation of the first supporting face plate and the second supporting face plate Provided with a plurality of stay members that determine the distance in the axial direction of the shaft,
The support face plate distance adjustment means for adjusting the distance between the first support face plate and the second support face plate at a position where some of the plurality of stay members are fixed as the support face plate inclination adjusting means. With means,
The second support relative to the first support face plate by changing the distance between the first support face plate and the second support face plate at the position where the part of the stay members are fixed by the distance adjustment means between the support face plates. A roller device that adjusts the inclination of a face plate. The roller device according to claim 7, wherein
As the plurality of stay members, a fixed stay member whose position relative to the first support face plate and the second support face plate is fixed, and a distance from the first support face plate to the second support face plate at the fixed position is adjusted. A roller device comprising: a support member configured to be capable of adjusting a distance between supporting face plates. The roller device according to claim 8, wherein
A roller device, wherein the fixed stay member and the stay member capable of adjusting the distance between the support face plates are made of a material having substantially the same thermal expansion coefficient. The roller device according to claim 8 or 9,
As the support face plate distance adjusting means, a spacer member is configured to be detachable between at least one of the first support face plate and the second support face plate and the stay member capable of adjusting the distance between the support face plates,
The distance between the first support face plate and the second support face plate at a position where the stay member capable of adjusting the distance between the support face plates is fixed can be changed by changing the number of mounting spacer members. Roller device. The roller device according to claim 8 or 9,
The support face plate distance adjusting means is configured to adjust the length of the support face plate distance adjustable stay member,
By adjusting the length of the support face plate distance adjustable stay member, the distance between the first support face plate and the second support face plate at the position where the support face plate distance adjustable stay member is fixed can be changed. A roller device, characterized by being configured as described above. The roller device according to claim 8, 9, 10 or 11,
The adjustment of the inclination of the second support face plate with respect to the first support face plate is performed by displacing the position of the second support face plate with respect to the first support face plate at a position where the stay member capable of adjusting the distance between the support face plates is fixed. Done,
The second support face plate and the support face plate distance adjustable stay member are fixed by screwing with a plurality of screws,
The roller device, wherein a shape of the second support surface plate at a position where the stay member capable of adjusting the distance between the support surface plates is fixed in the second support surface plate is a peninsula shape. The roller device according to claim 8, 9, 10, 11 or 12,
The adjustment of the inclination of the second support face plate with respect to the first support face plate is performed by displacing the position of the second support face plate with respect to the first support face plate at a position where the stay member capable of adjusting the distance between the support face plates is fixed. Done,
The second support face plate and the support face plate distance adjustable stay member are fixed by screwing with a plurality of screws,
Among a plurality of screwing positions, the screwing position close to the fixed stay is on or near the straight line connecting the rotation centers of the two roller members that are targets of the distance between the rollers on the second support face plate. The roller device is disposed so as to be positioned at the center. The roller device according to claim 6, 7, 8, 9, 10, 11, 12 or 13,
Of the two bearing parts that support both ends of one of the two roller members that are subject to the distance between the rollers, at least one of the bearing parts is the first support face plate on which the bearing part is disposed or The roller device, wherein the position in the axial direction is offset with respect to the second support face plate. A photoreceptor,
A developing device having a developing roller for developing a latent image on the photosensitive member, the surface of which forms a developing gap with the surface of the photosensitive member;
A first support face plate that supports one axial end of the rotating shaft of the photoconductor and one axial end of the rotating shaft of the developing roller;
The photoconductor and the developing roller are disposed opposite to the first support face plate, and support the other axial end of the rotating shaft of the photoconductor and the other axial end of the rotating shaft of the developing roller. An imaging device having a second support face plate
14. The image forming apparatus according to claim 6, wherein the image forming apparatus includes the photosensitive member and the developing roller as the two roller members, and the roller apparatus according to claim 6, 7, 8, 9, 10, 11, 12, or 13. apparatus. The imaging device of claim 15,
Extending in the axial direction of the rotating shaft, both ends in the axial direction are fixed to the first supporting face plate and the second supporting face plate, respectively, and the rotation of the first supporting face plate and the second supporting face plate Provided with a plurality of stay members that determine the distance in the axial direction of the shaft,
The support face plate distance adjustment means for adjusting the distance between the first support face plate and the second support face plate at a position where some of the plurality of stay members are fixed as the support face plate inclination adjusting means. With means,
The second support relative to the first support face plate by changing the distance between the first support face plate and the second support face plate at the position where the part of the stay members are fixed by the distance adjustment means between the support face plates. An imaging device characterized by adjusting the inclination of the face plate. The imaging device of claim 16,
As the plurality of stay members, a fixed stay member whose position with respect to the first support face plate and the second support face plate is fixed, and a distance from the first support face plate to the second support face plate at the fixed position is adjusted. An image forming apparatus comprising: a support member configured to be capable of adjusting a distance between supporting face plates. The imaging device of claim 17,
The adjustment of the inclination of the second support face plate with respect to the first support face plate is performed by displacing the position of the second support face plate with respect to the first support face plate at a position where the stay member capable of adjusting the distance between the support face plates is fixed. Done,
The second support face plate and the support face plate distance adjustable stay member are fixed by screwing with a plurality of screws,
The developing device has two developing rollers,
Among the plurality of screwing positions, the screwing position close to the fixed stay is on a straight line connecting the midpoint of the rotation centers of the two developing rollers on the second support face plate and the rotation center of the photosensitive member, or the straight line thereof. The image forming apparatus is arranged so as to be located in the vicinity of The imaging device according to claim 17 or 18,
The adjustment of the inclination of the second support face plate with respect to the first support face plate is performed by displacing the position of the second support face plate with respect to the first support face plate at a position where the stay member capable of adjusting the distance between the support face plates is fixed. Done,
A plurality of stay members capable of adjusting the distance between the support face plates are provided, and the distance from the first support face plate to the second support face plate at a position where the plurality of stay member capable of adjusting the distance between the support face plates is fixed is adjusted independently of each other. Configured and possible
The developing device has two developing rollers,
The fixing positions of the plurality of support members that can adjust the distance between the support surface plates with respect to the second support surface plate are on a straight line orthogonal to a straight line connecting a midpoint of the rotation centers of the two developing rollers and the rotation center of the photoconductor. An image forming apparatus, wherein the image forming apparatus is disposed so as to be positioned in the vicinity of the orthogonal straight line. The imaging device of claim 17, 18 or 19,
The adjustment of the inclination of the second support face plate with respect to the first support face plate is performed by displacing the position of the second support face plate with respect to the first support face plate at a position where the stay member capable of adjusting the distance between the support face plates is fixed. Done,
The first support face plate is provided with a fixing portion for fixing the image forming apparatus to the image forming apparatus, and the stay member capable of adjusting the distance between the support face plates is fixed to the fixing portion and the first support face plate. An image forming apparatus, wherein the image forming apparatus is disposed so as to be separated from a position to be performed. The imaging device of claim 20,
There are a plurality of fixing portions for the image forming apparatus of the first support face plate,
An image forming apparatus characterized in that the bending strength of the first support face plate in the vicinity of at least one of the fixed portions is reduced. The imaging device according to claim 17, 18, 19, 20 or 21,
The first support face plate and the second support face plate are arranged between the fixed portion of the fixed stay member and the fixed portion of the stay member capable of adjusting the distance between the support face plates. An image forming apparatus having a configuration in which a positioning mechanism for the photosensitive member is disposed. The imaging device of claim 17, 18, 19, 20, 21 or 22,
An image forming apparatus, wherein the developing device 4 also functions as the fixed stay member by fixing the developing device to the first supporting face plate and the second supporting face plate. 25. An imaging device according to claim 15, 16, 17, 18, 19, 20, 21, 22 or 23.
A photoreceptor positioning mechanism that positions the photoreceptor relative to each of the first support face plate and the second support face plate,
A photosensitive member bearing member that is a rotation supporting member that rotatably supports the photosensitive member with respect to the first supporting face plate and the second supporting face plate; at least one of the photosensitive member bearing members includes a photosensitive member bearing member; An image forming apparatus, wherein the position of the rotation shaft in the axial direction is offset with respect to the first support face plate or the second support face plate. 25. The imaging device of claim 24.
The displacement amount of the photosensitive member bearing member when the inclination of the second supporting surface plate with respect to the first supporting surface plate is changed, the photosensitive member bearing member disposed on the first supporting surface plate, and the second supporting surface plate. An image forming apparatus having a configuration different from that of the photoconductor bearing member disposed in the apparatus. 26. The imaging device of claim 25.
The amount of offset with respect to the support surface plate on which the photoconductor bearing member is arranged is different between the photoconductor bearing member arranged on the first support surface plate and the photoconductor bearing member arranged on the second support surface plate. An image forming apparatus characterized by being configured as described above. 27. The imaging device of claim 25 or 26.
The bending strength of the first support face plate and the second support face plate with respect to a straight line connecting the rotation center of the developing roller and the rotation center of the photoconductor is different between the first support face plate and the second support face plate. An image forming apparatus characterized by that. 28. An imaging device according to claim 25, 26 or 27.
A position on the support surface plate where the displacement amount of the photoconductor bearing member when the inclination of the second support surface plate is changed with respect to the first support surface plate is small is supported on the support surface plate. An image forming apparatus comprising a developing roller position adjusting mechanism for adjusting. The imaging device of claim 30,
The developing device has a plurality of developing rollers,
An image forming apparatus comprising the developing roller position adjusting mechanism independent of each of the plurality of developing rollers. 30. An imaging device according to claim 25, 26, 27, 28 or 29.
On the support face plate side on the side where the displacement amount of the photoconductor bearing member is large when the inclination of the second support face plate with respect to the first support face plate is changed.
An image forming apparatus comprising a developing roller driving mechanism for transmitting driving to the developing roller. The imaging device of claim 25, 26, 27, 28, 29 or 30,
The operation position of the support face plate inclination adjusting means is arranged on the support face plate on the side of the first support face plate or the second support face plate that is easily accessible when the image forming device is placed on the image forming apparatus main body. And
The support face plate is on the support face plate side where the displacement amount of the photoconductor bearing member when the inclination of the second support face plate with respect to the first support face plate is changed is smaller than the other. Imaging device. In a process cartridge that includes at least an image forming unit including a photosensitive member and a developing unit, and is detachable from the image forming apparatus main body.
32. A process cartridge comprising the image forming device according to claim 15 as the image forming means. In an image forming apparatus including at least an image forming unit including a photosensitive member and a developing unit,
32. An image forming apparatus comprising the image forming apparatus according to claim 15 as the image forming means. The image forming apparatus according to claim 33.
Adjustment of the inclination of the second support face plate with respect to the first support face plate is performed by displacing a position of a part of the second support face plate with respect to the first support face plate,
With the image forming device arranged in the image forming apparatus main body,
2. The image forming apparatus according to claim 1, wherein the second support face plate is displaceable with respect to the main body of the image forming apparatus in an axial direction of the rotation shaft. A plurality of longitudinal members arranged in parallel in the longitudinal direction;
A first support face plate that supports one longitudinal end of the plurality of longitudinal members;
In a longitudinal member device having a second support face plate arranged opposite to the first support face plate across the plurality of longitudinal members and supporting the other longitudinal end of the plurality of longitudinal members,
A support face plate inclination adjusting means for adjusting the inclination of the second support face plate with respect to the first support face plate;
The distance between the two member members among the plurality of longitudinal members is adjusted by changing the inclination of the second support surface plate with respect to the first support surface plate by the support surface plate inclination adjusting means. A longitudinal member device.

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