JP3999215B2 - Image forming apparatus - Google Patents

Description

The present invention, the photosensitive body is supported in advance, an image forming apparatus having a plurality of image forming cartridge detachably mounted in the main.

[A] Prior art 1
An image forming means having a main body and a plurality of image forming cartridges detachably attached to the main body in a superposed arrangement in the direction of gravity by means of the image forming means with these image forming cartridges attached to the main body An image forming apparatus for forming an image on a photoconductor, wherein the photoconductor is supported on the image forming cartridge in advance, or the photoconductor is supported on the main body in advance and the image forming cartridge is mounted on the main body. There is an image forming apparatus having a configuration in which the image forming means supported in advance on the image forming cartridge is in contact with the photoconductor when mounted.

  In such an image forming apparatus, since each image forming cartridge is detachable from the main body, means for stably supporting the main body in the mounted state is necessary, and this mounting state is unstable. In other words, so-called banding occurs in an image created under the influence of vibration from the drive system.

  Therefore, an unknown image forming apparatus in which banding occurs will be described. 44 to 46 show an example of an image forming apparatus capable of forming a full color image having a plurality of image forming cartridges. In FIG. 44, the transfer belt 1 is supported by support rollers 2 and 3 in the vertical direction and is rotatably stretched. When the image is created, the transfer belt 1 is rotated so that the surface on which the transfer sheet is adsorbed moves in the direction of moving from bottom to top as indicated by the arrow.

  Four image forming cartridges 4, 5, 6, and 7 (hereinafter referred to as 4 to 7) are superposed in the vertical direction so as to face the surface of the transfer belt 1 from the bottom to the top. From the top, the image forming cartridge 4 is black (color code K), the image forming cartridge 5 is cyan (color code C), the image forming cartridge 6 is magenta (color code M), and the image forming cartridge 7 is yellow (color code Y). The latent image on the photoreceptor is visualized with toner.

  These image forming cartridges 4 to 7 have a common mechanical configuration. Therefore, the structure of the members constituting these image forming cartridges is also common. Therefore, the color symbols Y, M, C, and K are added to the end of the reference numerals indicating the members constituting each image forming cartridge, and the configuration of the image forming cartridge 5 is mainly described. Instead of the description of the configuration of the image cartridge.

  Each image forming cartridge 5 includes a photoconductor 8C and image forming means for forming an image on the photoconductor. The image forming means includes a charging roller 9C as a charging means provided around a drum-shaped photoconductor 8C, a developing roller 10C as a developing means for supplying toner to the photoconductor 8C, and the photoconductor 8C after transfer. A cleaning blade 12C for removing residual toner is included.

  The developing roller 10C is provided with a replenishing roller 11C for replenishing the developer to the developing roller 10C, and the developer is conveyed to the replenishing roller 11C while being agitated by the rotating bodies 13C and 14C. It is like that. A light beam Lb emitted from an optical writing means 10C described later is irradiated to an image writing position on the photoreceptor 9C and between the charging roller 9C and the developing roller 10C.

  Since the various members for image formation have a lifetime, the image forming cartridges 4 to 7 are used for convenience such as replacement and maintenance of the members. Therefore, as shown in FIG. .) Is provided so as to be attachable to and detachable from 22.

  Along with the attachment / detachment, fixing pins 16C and 17C are provided as positioning support means having a length in the attaching / detaching direction, that is, the direction perpendicular to the paper surface in FIG. Further, as shown in FIGS. 46 to 48, a drive joint 5C is provided as a drive force input means for applying a drive force to the image forming means and the like.

  In FIG. 45, the main body 22 is configured as a box-shaped frame. The frame is a hexahedron and a box-shaped structure. The structure includes a front plate 22a that forms a surface on which the image forming cartridge 5 is attached and detached, a rear plate 22b that forms a surface facing the front plate 22a, and a right surface that faces the front plate 22a. The right side plate 22c, the left side plate 22d constituting the left side toward the front side plate 22a, the top plate 22e constituting the ceiling surface, the bottom plate 22f constituting the bottom surface, and the like. The main body 22 is assembled into a frame having a box-like structure composed of the front side plate 22a, the rear side plate 22b, the right side plate 22c, the left side plate 22d, the top plate 22e, the bottom plate 22f, and the like. Each of these plates is shown in a simple shape in the drawing, but actually has a notch, a bent portion, a hole, and the like for mounting components, and has a complicated shape.

  The image forming cartridges 4 to 7 are inserted in the attachment / detachment direction in the axial direction of the photosensitive member from the mounting opening that is greatly opened in the vertical direction on the front side plate 22a. On the other hand, in FIGS. 47 and 48, a rectangular window is formed on the side of the image forming cartridge 5, and a part of the photoreceptor 8C is exposed from this window. A shaft integral with the photoconductor 8C is pivotally supported by the case of the image forming cartridge 5, and a tapered drive joint 15C is provided at the tip of the shaft.

  As shown in FIG. 49, mounting holes 16C ′ and 17C ′ that fit into the fixing pins 16C and 17C are formed in the front plate 22a constituting the main body 22, and as shown in FIGS. 46 and 49, The rear side plate 22b is provided with a driving joint 15C ′ shaped to fit into the driving joint 15C.

  45, 47, and 48, the image cartridge 5 is moved in the attaching / detaching direction, and the fixing pins 16C and 17C are attached to the mounting holes as shown in FIGS. When fitting to 16C ′ and 17C ′, the drive joint 15C is simultaneously fitted into the tapered hole of the driving joint 15C so that power can be transmitted. Thus, the original joint 15C ′ provided on the rear surface of the rear plate 22b and the drive joint 15C are fitted, and the fixing pins 16C and 17C are fitted into the mounting holes intended for the front plate 22a. Main fixing of the image forming cartridge 5 to 22 is performed. The driving joint 15c ′ is connected to a driving device (not shown). Thus, the image forming cartridge 5 is fixed to the main body 22 with three points as main fulcrums. The same applies to other image forming cartridges.

  In FIG. 44, a pair of registration rollers 18 are provided near the lower portion of the transfer belt 1. When forming a full-color image, a toe image is formed on each photoconductor in each color of black, cyan, magenta, and yellow in each of the image forming cartridges 4 to 7, and in synchronization with this, a toe image is formed on the sheet entry path indicated by an arrow. Then, the transfer sheet is fed onto the transfer belt 1 by the registration roller 18, and while moving upward together with the transfer belt 1, a toner image is transferred from each photoconductor. , C, and K, the color toner images are transferred onto the transfer sheet and discharged. The discharged transfer sheet is fixed with the superimposed transfer toner image through a fixing device (not shown) and discharged.

  In this way, image formation is performed, and when any of the image formation cartridges 4 to 7 is out of toner, or when the time required for the required maintenance is reached, the corresponding image formation is performed for replacement or maintenance. Only the image cartridge is removed from the main body 22 and is mounted after the required maintenance is performed. Alternatively, a new image forming cartridge is replaced and a new image forming cartridge is mounted.

  For example, the image forming cartridge 5 is supported and fixed at the three points of the fixing pins 16C and 17C and the drive joint 15C as described above in order to be detachable from the main body 22. The charging roller 9C, the developing roller 10C, and the like have shaft shapes, and the shaft portions at both ends of the shaft in the longitudinal direction are supported by the image forming cartridge 5, so that the image forming cartridge with respect to the main body 22 is required for accuracy. The fixing pins 16C and 17C, the drive joint 15C, and the like, which are the support points of No. 5, are provided on the side surface portion of the image forming cartridge 5 serving as the axial ends of the charging roller 9C and the developing roller 10C.

  In this way, the image forming cartridge 5 is supported at both ends in the longitudinal direction with a so-called bridged structure with respect to the main body 22, driving the transfer belt 1, driving the transfer sheet, driving the fixing device, and the like. Therefore, the vibration generated in the main body 22 reaches the image forming cartridge 5 and vibrates the image forming cartridge 5.

  As a basic vibration mode, a vertical vibration mode that generates a vertical vibration as shown by an arrow in FIG. 53A, or a torsional vibration that generates a vibration in a torsional direction as shown by arrows of different directions in FIG. 53B. Mode exists. When the image forming cartridge 5 as a whole vibrates in this way, the photosensitive member 8C is supported by the image forming cartridge 5, so that the vibration of the image forming cartridge 5 is directly transmitted to the photosensitive member 8C and is charged from the image forming cartridge 5. The vibration is transmitted to the photoconductor 8C through image forming means such as the roller 9C, the developing roller 10C, and the cleaning blade 12C, and the displacement due to the vibration of the photoconductor 8C mainly causes a shift between the image writing position and the image transfer position, and resonance. Scan pitch unevenness occurs in the sub-scanning direction (transfer belt 1 moving direction = vertical direction) according to the frequency. Such uneven scanning pitch results in periodic density unevenness in the sub-scanning direction on the image, and is called banding. The same applies to the other image forming cartridges 4, 6, 7.

  On the other hand, as another configuration of the image forming apparatus, there is a type in which a photoconductor is not provided on the image forming cartridge side and a photoconductor is axially supported on the main body side in advance. In this type of image forming apparatus, the image forming cartridge includes a developing roller and a toner hopper for supplying toner to the developing roller, and the image forming cartridge is detachable from the main body. It is supported by the main body by a configuration according to the fixing pins and drive joints shown in FIGS.

  In the image forming cartridge having such a configuration, for example, for the cyan image forming cartridge 5, when the image forming cartridge 5 is mounted on the main body 22, a developing roller 10C is provided in advance on the main body side. Abuts against 8C.

Alternatively, in FIGS. 50, 51, and 52B, for example, in the case of a cyan image forming cartridge, when the image forming cartridge 5 "is mounted on the main body 22, the photosensitive member 8C" provided in advance on the main body 22 side. On the other hand, the developing roller 10C ″ provided in the image forming cartridge 5 ″ is arranged at a minute fixed interval from the photoconductor 8C ″. In this case, FIG. 50 shows a means for maintaining the minute fixed interval. As shown in the drawing, the image forming cartridge 5 ″ side has a large diameter that can be spaced apart from the diameter of the developing roller 10C ″ at both ends in the axial direction of the developing roller 10C ″ as a part of the image forming means. Rings 10C ″ -1, 10C ″ -2 are provided. On the other hand, when the photoconductor 8C ″ is previously supported on the main body 22 and the image forming cartridge 5 ″ is mounted on the main body 22, the ring 10C ″ is provided. -1, 10C -2 photoreceptor 8C 'and is adapted to hold a predetermined distance and "developing roller 10C by abutting the ends of the axial direction of the" photoreceptor 8C.

  This relationship is the same for the other image forming cartridges 4 ″, 6 ″, and 7 ″. That is, as shown in FIG. 51, photosensitive members 8K ″, 8M ″, and 8Y ″ are supported in advance on the main body 22. Yes. On the other hand, as shown in FIGS. 52 (a), 52 (c), and 52 (d), the image forming cartridges 4 ″, 6 ″, and 7 ″ correspond to the rings 10C ″ -1, 10 ″ -2. Developing rollers 10K ", 10M", 10Y "having a ring are pivotally supported. By mounting these image forming cartridges 4 ″, 6 ″, and 7 ″ on the main body, the developing rollers 10K ″, 10M ″, and 10Y ″ are held at a constant distance from the photoreceptors 8K ″, 8M ″, and 8Y ″. become.

  In the image forming apparatus having such a configuration, the developing roller 10C ″ integrated with the image forming cartridge by being supported by the image forming cartridge or the rings 10C ″ -1 and 10C ″ -2 as the interval regulating members are provided in the main body. When the image forming cartridge vibrates in order to abut on the photosensitive member 8C ″ supported in advance on the photosensitive member 8C ″, the photosensitive member 8C passes through the developing roller 10C ″ as the developing means or the rings 10C ″ -1, 10C ″ -2. "Vibrates and banding occurs as in the image forming cartridge 5 having the photoreceptor 8C.

  That is, for example, (a). In the configuration in which the photoconductor 8C is previously supported by the image forming cartridge 5 (more precisely, the case of the image forming cartridge), when the image forming cartridge 5 is mounted on the main body 22 and image formation is performed, the image forming is performed. When the cartridge 5 vibrates, this vibration is transmitted to the photoconductor 8C through image forming means such as the charging roller 9C, the developing roller 10C, and the cleaning blade 12C, thereby causing banding.

  In such a configuration, the photoconductor 8C and the developing roller 10C are supported by the same supported portion (image forming cartridge 5), so that the rings 10 "-1, 10" as the spacing regulating members as shown in FIG. -2 can maintain the gap between the photosensitive member 8C and the developing roller 10C with high accuracy even without providing 2. However, even in this case, the vibration of the image forming cartridge 5 is transmitted to the photosensitive member 8C, and the charging roller 9C and the cleaning roller are cleaned. Since the image forming cartridge 5 is provided with the blade 12C and the like, when the image forming cartridge 5 vibrates, the photoconductor 8C also vibrates through the image forming means such as the charging roller 9C and the cleaning blade 12C. So banding occurs.

  Also, (b). As described with reference to FIGS. 50 to 53, the photoconductor 8C ″ is preliminarily supported on the main body, and when the image forming cartridge is mounted on the main body, the photoconductor 8C ″ on the main body side is preliminarily supported on the image forming cartridge. Development means (developing roller 10C "or rings 10" -1, 10 "-2 as spacing regulating members) in contact with the photoconductor 8C", or image forming Even in a configuration in which any one of the charging unit and the cleaning blade as a unit, or a plurality of them contact each other, the vibration of the image forming cartridge is transmitted to the photoconductor 8C ″ through these image forming units, so that banding occurs.

  Banding caused by vibration of these image forming cartridges is visually very easy to distinguish near 0.5 mm pitch, but it becomes difficult to visually distinguish when vibration becomes high frequency and the pitch on the image is narrowed. There are features. For this reason, when the resonance frequency in the above-described vibration mode is low, it is easy to visually discriminate, and the image quality may be seriously impaired. Further, in an image forming apparatus provided with a plurality of image forming cartridges, the drive device of each image forming cartridge becomes complicated, and therefore banding due to vibration becomes remarkable.

Conventionally, as a known means for supporting an image forming unit configured to be detachable from a main body in an image forming apparatus, there is a technique as described below.
a. An elastic member fixed to a push-up member integral with the image forming apparatus main body in a configuration in which a process cartridge in which four juxtaposed developing devices are integrally mounted with a photosensitive belt is attached to and detached from the image forming apparatus main body. (See, for example, Patent Document 1).
b. For each of a plurality of toner cartridges detachably attached to the developing device provided opposite to the latent image carrier, the adjacent toner cartridges are arranged so as not to cause backlash between the toner cartridges when the developing device rotates. The structure which provided the uneven | corrugated groove | channel which can be attached or detached (for example, refer patent document 2).
b. A toner cartridge that is detachably attached to an image forming apparatus and is attached to a process cartridge having a photosensitive drum and replenishes toner, and includes a guide member that regulates the position of the toner cartridge that is pushed into the toner storage unit of the process cartridge (for example, (See Patent Document 3).
[B] Prior art 2
In FIG. 44, four optical writing means 104K, 104C, 104M, and 104Y are arranged in a superimposed manner in the gravity direction corresponding to the four image forming cartridges 4, 5, 6, and 7. These optical writing units 104K, 104C, 104M, and 104Y have a common mechanical configuration. Therefore, the members constituting the optical writing means have the same configuration. Therefore, the color codes Y, M, C, and K are added to the end of the reference numerals indicating the members constituting each optical writing unit, and the configuration of the optical writing unit 104C will be mainly described, so that It replaces with description of the structure of a writing means. Further, the operation content is merely the difference that the emitted light beam Lb corresponds to each color image, and the others are common, so that the operation is mainly performed for the optical writing means 104C and the image forming cartridge 5 corresponding thereto. Thus, the description of the other optical writing means and the image forming cartridge will be substituted.

  By scanning the light beam Lb on the photoconductor 8C by the light writing means 104C, an electrostatic latent image is formed on the photoconductor 8C. In the optical writing unit 104C, a light beam generated by a laser diode (not shown) is scanned for the polygon mirror 106C, and the target beam is scanned through the first fθ lens 108C, the folding mirrors 110C and 111C, and the second fθ lens 112C. A beam spot is irradiated on the photoconductor 8C.

  In the image forming cartridge 5, in addition to the photoconductor 8C, as described above, a cleaning unit, a charging unit, a developing unit, a toner, and other parts necessary for image formation and having a replacement life are provided. In such an image forming apparatus, since the image forming cartridges 4, 5, 6, and 7 are arranged at short intervals in the vertical direction, the optical writing units 104K, 104C, and 104 are provided between the image forming cartridges 4, 5, 6, and 7, respectively. 104M and 104Y cannot be installed. Therefore, these optical writing means are arranged at positions relatively distant from the photoconductors 8K, 8C, 8M, and 8Y in the horizontal direction.

For example, in the optical writing unit 104C, when vibration occurs in the optical writing unit 104C, the beam displacement on the photoconductor 8C becomes large, and a phenomenon called banding described later tends to occur. As described with reference to FIG. 45, the main body 22 basically includes a front plate 22a, a rear plate 22b, a right plate 22c, a left plate 22d, a top plate 22e, and a bottom plate 22f.
54 and 55, with respect to the optical writing means 104C, a plate-like base member 328C is placed between the front side plate 22a and the rear side plate 22b, and the optical writing means 104C is installed on the base member 328C. ing.

  The rear end portion of the base member 328C is fixed to the rear side plate 22b, and the front end portion is supported by the front side plate 22a via the adjusting means 330C. A bridge structure is formed by the base member 328C and the adjusting means 330C.

  The adjusting unit 330C has a mechanism for displacing the front end portion of the base member 328C in the vertical direction, and can adjust the inclination of the scanning line in the sub-scanning direction of the light beam Lb emitted from the optical writing unit 104C. ing. Such adjustment in each optical writing means can prevent the four color images from being superimposed with different inclinations.

  In order to enable displacement of the base member 328C by adjustment, a slit-shaped notch 128a is formed at the rear end of the base member 328C as shown in FIG. 54, so that the hinge function can be easily expressed. ing. Here, the adjusting means 330K, 330C, 330M, and 330Y are provided corresponding to all four colors, respectively, but the base member of the optical writing means corresponding to one reference color is directly connected to the front without using the adjusting means. The configuration may be such that one adjustment means is omitted by fixing between the side plate 22a and the rear side plate 22b.

In addition to the above-described configuration, there are techniques described in the following patent documents as techniques relating to position adjustment of the optical writing means or prevention of positional deviation.
(1) An optical writing means attached to the device structure via a spring, screw or the like so as to be adjustable (see, for example, Patent Document 4), (2) Ceramic, etc. to prevent color shift due to thermal expansion The device structure is formed of a material having a small coefficient of thermal expansion (for example, see Patent Document 5). (3) An optical member is used between the housing and the cover of the optical writing means to suppress the vibration of the cover and perform optical writing. (For example, refer to Patent Document 6).

  As described above, the image forming cartridges 4, 5, 6, 7 and the optical writing means 104K, 104C, 104M, 104Y can be reduced in size by superimposing them in the direction of gravity, but the base members 328K, 328C, Since 328M and 328Y and the adjusting means 330K, 330C, 330M, and 330Y have a bridge structure, as a basic vibration mode, for example, for the optical writing means 104C, the vertical vibration mode shown in FIG. The torsional vibration mode shown in (b) exists. The same applies to the other optical writing means 104K, 104M, and 104Y.

  For this reason, when the vibration of the driving device or the like is transmitted via the front side plate 22c and the rear side plate 22b and the entire optical writing means 104C is vibrated, a periodic displacement of the light beam position on the photoconductor 8C is caused. Scanning pitch unevenness in the sub-scanning direction according to the resonance frequency occurs, and periodic density unevenness in the sub-scanning direction is generated on the image, resulting in banding.

  This banding is also visually easy to discriminate in the vicinity of 0.5 mm pitch, but has a feature that it becomes difficult to discriminate visually when the vibration has a higher frequency and the pitch on the image is narrowed. For this reason, when the resonance frequency in the vibration mode is low, it is easy to visually discriminate, and the image quality is remarkably impaired.

Further, in an image forming apparatus provided with a plurality of optical writing means, (a) the driving device tends to be complicated and the vibration generation level tends to be high, and (b) the cross-sectional area of the optical writing means due to the demand for downsizing the apparatus. (C) it is difficult to construct a structure having sufficient strength around the optical writing means due to space limitations. The problem of banding is more serious than that of an image forming apparatus compatible with a single color that uses optical writing means.
[A] Prior art 1 has a problem of banding caused by vibration of the image forming cartridge, and [B] Prior art 2 has a problem of banding caused by vibration of the optical writing means.

JP-A-5-313425 JP-A-6-148968 JP 10-20647 A Japanese Patent Laid-Open No. 5-6071 JP-A-7-104545 JP-A-6-34901

SUMMARY An advantage of some aspects of the invention is that it provides an image forming cartridge and an image forming apparatus capable of preventing banding due to vibration of an optical writing unit.

In order to achieve the object, the present invention has the following configuration.
(1). A main body configured in a box-shaped structure including a front side plate, a rear side plate, a right side plate, a left side plate, a top plate, and a bottom plate, and a photoconductor are supported in advance and superimposed on the main body. A plurality of image forming cartridges that are disposed and detachably mounted; and a plurality of image writing devices that irradiate the photosensitive member with a light beam, wherein the plurality of image forming cartridges are mounted on the main body. an image forming apparatus for forming an image in a state of even city has a vertical stay which is provided between said image writing device and said plurality of image forming cartridge and the structural member for an image writing device partition that tabular, The vertical stays are fixed to the front plate, the rear plate, the top plate, and the bottom plate, respectively, and the structural members for partitioning the image writing device are fixed to the front plate, the rear plate, and the vertical stay, respectively. Accordingly, the light beam emitted from the image writing device passes through the opening provided in the vertical stay, and writing is performed on the photoconductor.
(2). The image forming apparatus according to (1), said openings have a size der Rukoto minimum width and length passing said light beam (Claim 2).

In the present invention, by providing the vertical stays fixed to the both side plates, the rigidity of the structure constituting the main body of the image forming apparatus is increased, and the banding caused by the vibration of the image forming cartridge and the optical writing device can be reduced. .

Embodiments of the present invention will be described below.
[1] First Embodiment The example described below is an improved configuration based on the configuration mainly related to the image forming cartridge described in FIGS. 44 to 52 in the section [A] Prior Art 1. It is added.

  Since the present invention is intended to prevent banding due to the vibration of the photosensitive member due to the vibration of the image forming cartridge, it has been described above. A configuration in which the photosensitive member is previously supported by an image forming cartridge (more precisely, an image forming cartridge case); A charging roller, a developing roller, or an interval as an image forming means that is supported in advance by the image forming cartridge with respect to the photoconductor on the main body side when the image forming cartridge is mounted on the main body and the image forming cartridge is mounted on the main body. The present invention can be applied to any configuration in which any one or a plurality of developing means and a cleaning blade having a regulating member are in contact with the photosensitive member.

Hereinafter, the configuration described with reference to FIGS. 44 to 49 and FIG. 53, that is, an image forming apparatus of a type in which a photoconductor is provided on the image forming cartridge side and no photoconductor is provided on the main body side will be described. However, as described with reference to FIGS. 50 to 52, the image forming cartridge is not provided with a photoconductor, and the image forming cartridge is provided on the main body side. Rings 10C "-1 and 10C" -2 as spacing regulating members that contact the developing roller that contacts the photoconductor or the photoconductor provided on the main body side are provided. Photoreceptor contact means (development rollers or rings 10C ″ -1, 10C ″ -2 as spacing regulating members) provided on these image forming cartridges by being mounted on the main body are provided on the main body side. Even for contacting type image forming apparatus to the photosensitive body that is, it shall be able to apply the examples described below.
(1) Example 1
Example 1 will be described with reference to FIG. FIG. 1A is a view of the main part of the image forming apparatus to which the image forming cartridge is mounted as viewed from the front, and FIG. 1B is a view of the main part of the image forming apparatus as viewed from the side.
In order to reduce the size of the image forming apparatus, it is desirable that a plurality of image forming cartridges arranged in a superposed manner in the direction of gravity be mounted with a narrow pitch in the vertical direction. In this example, among the plurality of image forming cartridges 4 to 7 arranged at a narrow pitch, the adjacent image forming cartridges are divided into structural members (hereinafter referred to as horizontal stays) 25 for separating these image forming cartridges. It is provided between the image forming cartridges 4, 5, 6, 7. That is, the horizontal stay 25 is provided between the image forming cartridge 4 and the image forming cartridge 5, between the image forming cartridge 5 and the image forming cartridge 6, and between the image forming cartridge 6 and the image forming cartridge 7. . Also, a horizontal stay 25 similar to the above is provided so as to face the portion facing the upper surface of the image forming cartridge 4 and the lower surface of the image forming cartridge 7.

  These horizontal stays 25 are composed of plate-like members whose upper ends are bent upward in a direction perpendicular to the mounting / demounting direction of each image forming cartridge, and in the vicinity of the mounting port of the image forming cartridge formed on the front side plate 22a. It is being fixed with the fastening means not shown with respect to a part and the back side board 22b.

  Each image forming cartridge 4, 5, 6, 7 is supported on the upper surface of the horizontal stay 25. Since the horizontal stay 25 is fixed to the vicinity of the end of the image forming cartridge on the front plate 22a and the rear plate 22b by fastening means, the front plate 22a and the rear plate 22b are fixed by the horizontal stay 25 to the image forming cartridge. It will be fastened in the immediate vicinity.

  As for the image forming cartridge 5, it is possible to effectively suppress vibrations of the fixing pins 16C and 17C, the drive joint 15C, and the like using the front side plate 22a and the rear side plate 22b as scaffolds. The same applies to other image forming cartridges. In particular, the horizontal stay 25 has a structure in which the front plate 22a and the rear plate 22b vibrate in plane vibration. The horizontal stay 25 has a structure that divides the surface, thereby eliminating the low-frequency resonance mode that is disadvantageous for banding, and the high-frequency resonance mode. It is only effective.

  As shown in FIG. 1, in a configuration in which a similar horizontal stay 25 is provided above the image forming cartridge 4 positioned at the uppermost portion without the adjacent image forming cartridge and below the image forming cartridge 7 positioned at the lowermost portion, Since the rigidity of the entire support structure of the image forming cartridge is increased, it is suitable for preventing banding.

  In addition, the horizontal stay 25 can be provided with an opening and a notch to the extent that the strength is not impaired for the purpose of securing a cooling path and forming a mounting shape. In addition, since the edge of the horizontal stay 25 is exposed at the mounting port of the image forming cartridge, it is preferable to bend or fold back in order to improve safety and strength.

  Since the image forming cartridges 4, 5, 6, and 7 have substantially the same cross-sectional shape, for example, extending in the axial directions of the photoconductors 8K, 8C, 8M, and 8Y, the photoconductor as in this example. If it is attached / detached in the axial direction, even if the unevenness along the cross-sectional shape of the image forming cartridge is formed on the horizontal stay 25 as well, it does not cause interference at the time of attachment / detachment, thereby increasing the strength of the structure and eliminating waste of space. Can do.

Furthermore, since the image forming cartridges 4, 5, 6, and 7 have the same mechanical configuration except for the color of the developer to be stored, they can be manufactured with the same specifications and are efficient in mass production. It becomes the target.
In carrying out this example, for the photoconductors 8Y, 8M, 8C, 8K and the like that require precise positioning accuracy with respect to the main body 22, for example, the bearings of the drive shafts of these photoconductors are provided correspondingly. It is preferable to provide a support structure that is supported with play (clearance) in a direction perpendicular to the axis with respect to the image cartridge. Further, the image forming cartridge is positioned and fixed at a predetermined position on the horizontal stay 25. In this case, when the image forming cartridge is fixed to the main body, the drive shaft of the photosensitive member supported by the image forming cartridge having play is moved within the play range and shown in FIG. Such a driving joint 15C is joined to a driving joint 15C ′ provided on the main body side, and a power transmission state can be obtained.

As described above, if the photosensitive member is supported in a floating manner with respect to the image forming cartridge, when the image forming cartridge is positioned and supported with respect to the main body 22 via the horizontal stay 25, the driving shaft of the photosensitive member is provided. The drive joint integrated with the drive system is joined with the drive joint of the drive train. As a result, the photoconductor is precisely positioned on the main body, and the image forming cartridge does not need to have a support structure in which the photoconductor is precisely positioned and supported with respect to the image forming cartridge. In addition, the image forming cartridge is supported by the horizontal stay 25, so that vibration can be suppressed. Therefore, it is possible to achieve both maintenance of the accuracy of attaching the photosensitive member to the main body and suppression of vibration of the image forming cartridge. A plurality of horizontal stays are superimposed in the direction of gravity corresponding to a plurality of image forming cartridges arranged in a superposed manner in the direction of gravity, so that vibrations in the vertical direction can be effectively suppressed and banding can be prevented. ,It is valid.
(2) Example 2
FIG. 2A is a view of the main part of the image forming apparatus to which the image forming cartridge is mounted as viewed from the front, and FIG. 2B is a view of the main part of the image forming apparatus as viewed from the side. For example, the lower surface portion of the image forming cartridge 5 is formed with a W-shaped curved surface along the curved surfaces of the adjacent rotating bodies 13C and 14C, and the boundary portion between the two convex downward curved surfaces is in the attaching / detaching direction. It is formed in a concave shape having a length.

  In this example, on the upper surface of the horizontal stay 25 described in (1) above, the concave portion formed on the lower surface of the image forming cartridge 5 and having a length in the attaching / detaching direction is used as the guided portion 26C. A guide portion 27 </ b> C made of a plate-like member that engages with and guides the image forming cartridge 5 is provided so as to stand upright on the surface of the horizontal stay 25. The same applies to other image forming cartridges. The horizontal stay 25 positioned above the image forming cartridge 4 is not provided because there is no object to be guided.

  In this example, the guided portion 26C is thus the rotating bodies 13C and 14C, the guided portion 26K is the rotating bodies 13K and 14K, the guided portion 26M is the rotating bodies 13M and 14M, and the guided portion 26Y is the rotating body 13Y. The w-shaped shape of the casing of the image forming cartridge along the outline of 14Y is used.

  As described above, since the guide portions are provided along the concave portions constituting the guided portions of the image forming cartridges 4, 5, 6, and 7, the image forming cartridges are attached and detached when the image forming cartridges are mounted. It is possible to prevent shifting to the right and left directions orthogonal to each other and turning to cause unnecessary collision or damage.

  In this example, the heights of the guide portions 27K, 27C, 27M, and 27Y are increased from the middle as shown in FIG. By doing so, in the latter half of the operation of mounting the image forming cartridge, the gap between each guide portion and each guided portion becomes small and can be guided with high accuracy, and the operability of attaching / detaching operations and maintaining the accuracy during mounting are maintained. Is done well.

The guide portions 27K, 27C, 27M, and 27Y having a guide rail function may be formed integrally with the horizontal stay 25 that is a structural member, or a separate part that is manufactured is fixed integrally by a fastening means. It can also be configured. Further, by forming the guide portions 27K, 27C, 27M, and 27Y in a vertical plate shape as in this example, the bending rigidity in the vertical direction of the horizontal stay 25 can be increased, so that mechanical strength is improved and banding is prevented. Above, it is preferable.
(3) Example 3
FIG. 3A is a view of the main part of the image forming apparatus to which the image forming cartridge is mounted as viewed from the front, and FIG. 3B is a view of the main part of the image forming apparatus as viewed from the side.

  In this example, among the horizontal stays 25 described in (1) above, between the image forming cartridge 4 and the image forming cartridge 5, between the image forming cartridge 5 and the image forming cartridge 6, and between the image forming cartridge 6 and the image forming cartridge 7. For each horizontal stay 25 in between, a pressing means for pressing each adjacent image forming cartridge was provided. These pressing means generate an elastic pressing force between each adjacent image forming cartridge and the horizontal stay.

  As shown in FIGS. 3 and 6, the pressing means is configured with leaf springs 28 </ b> U and 28 </ b> D. Each of the leaf springs 28U and 28D has a fixed portion 28a and a curved portion 28b. The fixed portion 28a is fixed to the upper surface of the horizontal stay 25 so that the convex portion of the curved portion 28b faces upward. In the leaf spring 28D, the fixed portion 28a is fixed to the lower surface of the horizontal stay 25 so that the convex portion of the curved portion 28b faces downward.

  The plate springs 28U and 28D are fixed at the upper and lower surfaces near the center of the horizontal stay 25. The plate spring 28U applies an upward elastic pressing force to the image forming cartridge 4 mounted on the horizontal stay 25. The leaf spring 28D is configured to apply a downward elastic pressing force to the image forming cartridge 5 mounted below the horizontal stay 25, respectively. Paying attention to the leaf spring provided on the horizontal stay 25 between the image forming cartridge 4 and the image forming cartridge 5, the curved portion 28b of the leaf spring 28U elastically pushes up the upper image forming cartridge 4, and the leaf spring 28D. Acts to push down the lower image forming cartridge 5 elastically.

  The same applies to the plate springs 28U and 28D provided on the horizontal stay 25 between the image forming cartridge 5 and the image forming cartridge 6 and the horizontal stay 25 between the image forming cartridge 6 and the image forming cartridge 7, respectively. Since each of the image forming cartridges 4 to 7 supported in a bridge shape presses the abdomen of the vibration amplitude by the elastic pressure support by these leaf springs 28U and 28D, an effective vibration suppressing effect can be obtained. it can.

  When this example and the examples of the guide portions 27K, 27C, 27M, and 27Y shown in FIG. 2 are applied, the leaf springs 28U are as shown in FIG. The guide portions 27K, 27C, 27M, and 27Y are configured. In this case, for example, FIG. 4 described later is used so that the leaf springs 28U do not interfere with the guide portions 27K, 27C, 27M, and 27Y. As in the example in (a), each image forming cartridge is provided with leaf springs 28U at two positions so as to abut against two convex portions positioned with the concave portion in between so as to avoid interference.

  If the elastic force of the plate spring 28D for pressing the upper surface and the plate spring 28U for pressing the lower surface of an arbitrary image forming cartridge is made substantially the same and provided at the opposing position, the elastic force is canceled and the entire image forming cartridge is bent. This is preferable because it does not occur. For the above reasons, it is preferable to provide leaf springs or equivalent parts on the end surfaces of the upper and lower ends of the superposed arrangement without adjacent image forming cartridges.

  Further, when the image forming cartridge is mounted at the regular mounting position, the leaf springs 28U and 28D engage with the click recesses formed on the image forming cartridge to generate a click feeling. It is preferable that the effect of improving the frequency and preventing the banding can be obtained at the same time.

In addition, for example, if the engagement of the click recess is reinforced so as to assist the fixing in the mounting direction by elastic force, there is no need to provide a special mounting direction fixing means such as a lock lever. You can go down. If the leaf spring of this example is used in combination with the configuration in which the guide is provided as in the above-described example (2), the operability at the time of attaching and detaching the image forming cartridge can be improved. In addition, it can replace with leaf | plate springs 28U and 28D, and a press means can be comprised by the other means which consists of a member which has elasticity.
(4) Example 4
FIG. 4A is a view of the main part of the image forming apparatus to which the image forming cartridge is mounted as viewed from the front, and FIG. 4B is a view of the main part of the image forming apparatus as viewed from the side.

  An anti-vibration rubber 29 is provided as an anti-vibration means on the lower surface of the horizontal stay 25 located immediately above the image forming cartridge 4 so as to contact the upper surface of the image forming cartridge 4 and generate a viscoelastic pressing force therebetween. Provided. Similarly, an anti-vibration rubber 29 is also provided on the lower surface of the horizontal stay 25 positioned immediately above each of the image forming cartridges 5, 6, and 7. These anti-vibration rubbers 29 have a rectangular plate shape as shown in FIG. 7 and are affixed to the horizontal stay 25.

  Further, the leaf spring 28U described with reference to FIG. 6 is disposed on the upper surface of the horizontal stay 25 between the image forming cartridge 4 and the image forming cartridge 5 and in the vicinity of the position facing the position where the vibration isolating rubber 29 is provided. Was established. Similarly, on the upper surface of the horizontal stay 25 between the image forming cartridge 5 and the image forming cartridge 6, in the vicinity of the position facing the position where the anti-vibration rubber 29 is provided, the image forming cartridge 6 and the image forming cartridge 7. Leaf springs 28U are also provided on the upper surface of the horizontal stay 25 between the position where the anti-vibration rubber 29 is provided and in the vicinity of the opposing position.

  Here, as shown in FIG. 4 (a), the casing of the image forming cartridge is formed in a concave shape at the opposing portion where the vibration isolating rubber 29 is provided, so that the concave portion is avoided. It is set as the structure which provided the leaf | plate spring 28U in the convex two points | pieces which set the recessed part in the middle. These leaf springs 28U and the vibration isolating rubber 29 constitute the vibration isolating means in the present invention.

  Each leaf spring 28U elastically pushes the image forming cartridge upward. The image forming cartridge thus elastically pushed up is pressed so that a viscoelastic pressing force is generated by the vibration isolating rubber 29 in contact with the upper surface. Since the anti-vibration rubber is used in this way, the anti-vibration effect by the thermal conversion of vibration energy utilizing the viscoelastic characteristics becomes remarkable.

  In this example, even if the elastic force of the leaf spring is set to a low value, it is possible to obtain a vibration isolation effect due to the viscosity of the vibration isolation rubber 29, so that the force acting on the image forming cartridge can be reduced. In other words, since the deformation due to the leaf spring support can be reduced, it is also effective in maintaining accuracy.

By adopting the configuration in which the leaf spring and the vibration isolating rubber are used together as in this example, it is possible to effectively generate the pressing force of the image forming cartridge against the vibration isolating rubber. Further, the structure related to the guide part and the guided part described in (2) above is used in combination, and the guide shape is devised so that the frictional force of the vibration isolating rubber 29 is increased immediately before the completion of the mounting of the image forming cartridge. By doing so, an increase in operating force when the image forming cartridge slides with respect to the vibration isolating rubber 29 can be moderately reduced.
(5) Example 5
FIG. 5A is a view of the main part of the image forming apparatus to which the image forming cartridge is mounted as viewed from the front, and FIG. 5B is a view of the main part of the image forming apparatus as viewed from the side.

In this example, as shown by reference numeral 30 in FIGS. 5A and 8 so as to face the left side plate 22d in FIG. 45, a flat vertical plate as a second structural member is provided on the left end surface of the horizontal stay 25. A stay 30 was provided. In the vertical stay 30, mounting pieces 30b and 30b positioned opposite to each other in the scanning direction of the light beam Lb are fixed to a front side plate (first side plate) 22a and a rear side plate (second side plate) 22b, respectively. . Further, the upper end of the vertical stay 30 is fixed to the top plate 22e, and the lower end is fixed to the bottom plate 22f. A vertical plane portion is fixed to each horizontal stay 25 by a fastening member using a screw 210.

  Thus, since each horizontal stay 25 is firmly fixed and held on the main body via the vertical stay 30, the suppression of the surface vibration mode of the front side plate 22 a and the rear side plate 22 b is further strengthened, and it is perpendicular to each horizontal stay 25. Since the stay 30 is substantially orthogonal to the structure, the cross-sectional moment is very large, the bending rigidity is excellent, and the structure is extremely rigid.

  In particular, the improvement in flexural rigidity reduces and reduces the vibration of the horizontal stay 25 itself when performing vibration suppression as in the examples described in the above (3) and (4). Very effective.

  Further, in this example, the left side of each of the image forming cartridges 4, 5, 6, and 7 in FIG. 5A and a position that is not shown in the figure, with respect to the respective photoconductors 8K, 8C, 8M, and 8Y. If an image writing device that irradiates a light beam is arranged, and these image writing devices are also supported by a structure according to the structure 25 using the vertical stay 30, the vertical stay 30 is in the vertical direction. Each image forming cartridge or image writing device is in a state of receiving a compressive stress (buckling load) due to its own weight. Compared with a configuration in which an image forming cartridge for four colors and an image writing device are configured only on a horizontally-placed plate, the state of receiving the compressive stress is an increase in strength, a reduction in deformation, and a suppression of resonance. This is advantageous. This point will be described in detail in [3] Third Embodiment (1).

  Since it is necessary to guide the light beam Lb for writing on the photoconductors 8K, 8C, 8M, and 8Y to the left side of each of the image forming cartridges 4 to 7, the vertical stay 30 includes the vertical stay 30 as shown in FIG. An opening 30d having a length corresponding to the scanning direction of the light beam Lb and a width corresponding to the diameter of the light beam is provided.

As described above, since the opening 30d having a minimum width and length that allows the light beam Lb to pass through is formed in the vertical stay 30, a reduction in rigidity as a structure of the vertical stay is suppressed to the minimum, thereby preventing banding. ,It is valid.
A light beam Lb guided to each of the photoconductors 8K, 8C, 8M, and 8Y through the opening 30d is shown by a one-dot chain line in FIG. In addition to the optical path opening 30a described above, openings and notches are provided as needed to the extent that the strength is not impaired for the purpose of securing a cooling passage and forming a mounting hole.

  For example, in FIG. 8, the holes 30 c shown above and below the opening 30 d are for fixing the horizontal stay 25. Each of these holes 30c is merely an example, and the number of holes as necessary is appropriately formed. In this example, this configuration is realized by using fastening means by screws 210, but the realization method is not limited, for example, it is formed integrally by welding when using a metal material, or by injection molding when using a resin material. .

As described above, the embodiments have been described separately for the five configuration examples (1), (2), (3), (4), and (5). However, if these configurations are combined and implemented, This is more preferable because prevention and secondary improvement in operability and cost reduction can be realized with a synergistic effect.
3 and 4, the arrangement of the leaf springs 28U, 28D, etc. is shown schematically in outline, and is actually configured according to that shown in FIG. And Moreover, it can replace with leaf | plate spring 28U, 28D, and a press means can be comprised by the other means which consists of a member which has elasticity.
[2] Second Embodiment The example described below is an improved configuration based on the configuration mainly related to the optical writing means described in FIG. 54 and FIG. 55 in the section [B] Prior Art 2. It is added. The same parts as those in the prior art are denoted by the same reference numerals, and redundant description in terms of structure or function is omitted unless particularly necessary.
(1) Example 1
As shown in FIGS. 9 to 11, the image forming apparatus in this example is a full-color image forming apparatus. As described in [B] Prior Art 2, the four image forming cartridges 4, 5, 6, 7 are used. Are superimposed in the gravitational direction, and four optical writing units 104K, 104C, 104M, and 104Y are superimposed in the gravitational direction corresponding to these image forming cartridges. These optical writing means 104K, 104C, 104M, and 104Y have adjusting means 330K, 330C, 330M, and 330Y for adjusting the shift of the scanning line from the other optical writing means, as already described in the prior art. I have.

  As shown in FIG. 11, between the optical writing means 104K, 104C, 104M, and 104Y adjacent in the vertical direction, strictly between the base member 328K and the optical writing means 104C below the light writing means 104C, A writing member partitioning structural member 202 is arranged to partition the optical writing means. The structural member 202 is fixed to the front side plate 22a and the rear side plate 22b by fastening means (not shown).

  The same applies to the structural member 202 similarly provided between the optical writing unit 104C and the optical writing unit 104M and between the optical writing unit 104M and the optical writing unit 104Y. In FIG. 9, the base member 328K of the optical writing unit 104K, the base member 328C of the optical writing unit 104C, the base member 328M of the optical writing unit 104M, the base member 328Y of the optical writing unit 104Y, and the like are omitted.

  The presence of the structural member 202 provided between the optical writing means increases the structural strength of the front side plate 22a and the rear side plate 22b. As a result, the periphery of the fixing part of the optical writing means 104K, 104C, 104M, 104Y, that is, the front side plate The vibration around the fixed portion with respect to 22a and the rear side plate 22b is suppressed.

  In particular, since the structural member 202 has a structure in which the front plate 22a and the rear plate 22b vibrate in plane, the low frequency resonance mode in which banding is likely to occur is eliminated, and high frequency resonance is achieved. Only mode is effective.

  As indicated by two-dot chain lines P1 and P2 in FIG. 11, the structural member 202 may be similarly provided above the optical writing unit 104K where the adjacent optical writing unit does not exist and below the optical writing unit 104Y. In this case, the overall strength of the device structure can be further increased, and the banding suppression function can be enhanced.

The structural member 202 may be provided with openings and notches so as not to impair strength (strength at which the banding suppression function is exhibited) for the purpose of securing a cooling path and forming a mounting shape. Further, bending or folding may be provided to improve the strength.
In order to achieve further miniaturization of the apparatus, it is desirable that the image forming cartridges 4, 5, 6, and 7 and the optical writing units 104K, 104C, 104M, and 104Y are juxtaposed at a narrow pitch.
(D) Example 2
This will be described with reference to FIGS. 6, 12, and 13.
In this example, in addition to the structural member 202, for example, the structural member 202 between the optical writing unit 104C and the optical writing unit 104M is elastically pressed against the optical writing unit 104M on the lower surface of the structural member 202. A leaf spring 280D is provided as a pressing means for generating pressure, and a leaf spring 280U as a pressing means for generating elastic pressing force with respect to the optical writing means 104C is provided on the upper surface of the structural member 202. . The same applies to the other structural members 202.

  The leaf springs 280U and 280D as the pressing means are respectively the same as the leaf springs 28U and 28D already described with reference to FIG. 6 in terms of shape and material, and are attached to the upper and lower surfaces at the substantially central portion of the structural member 202. In the example shown in FIG. 13, the curved bulges of the curved portion 28b of the leaf spring 280U and the curved portion 28b of the leaf spring 280D have different sizes of the bulge, but this is due to the difference in the distance to the object to be pressed. This is because the positions relative to the base members 328K, 328C, 328M, 328Y and the like differ from the positions relative to the optical writing means 104K, 104C, 104M, 104Y and the like. In FIG. 12, the base members 328K, 328C, 328M, and 328Y are omitted. In this way, the leaf springs 280U and 280D are set to a size that applies a pressing force in the vertical direction to the optical writing means 104K, 104C, 104M, and 104Y, respectively, when assembled.

  For example, since the optical writing unit 104C is a member (movable member) that is displaced by the adjusting unit 330C together with the base member 328C, it cannot be directly fixed to the structural member 202. The same applies to the other optical writing means 104K, 104M, and 104Y.

  In order to obtain the function of supporting the optical writing unit 104C by the structural member 202 while maintaining the movable configuration of the optical writing unit 104C, leaf springs 280U and 280D as the pressing unit are provided. The pressing force by the leaf springs 280U and 280D is, for example, the amplitude of a vibration mode (see FIG. 56A) in which both ends of the optical writing means 104C located on the bridge structure are nodes and the center is an antinode. Therefore, in addition to the vibration suppressing function due to the presence of the structural member 202, a vibration suppressing function can be obtained. The same applies to the other optical writing means 104K, 104M, and 104Y.

  If the pressing forces of 280U and 280D are the same, the pressing force (elastic force) at the top and bottom of each of the optical writing means 104K, 104C, 104M, and 104Y is canceled, and it is preferable that these optical writing means are not bent. .

In this example, leaf springs 280U and 280D are also attached to the upper surface of the uppermost structural member 202 and the lower surface of the lowermost structural member 202. Since there is actually no member to be pressed, the pressing function cannot be exerted. However, this is significant from the viewpoint of uniformizing the structural member 202 having the leaf springs 280U and 280D, that is, generalization, and optical writing. In the configuration in which the number of means is further increased, there is an advantage that the same structural member 202 can be used immediately. Further, from the viewpoint that the mechanical strength of the structural member 202 is improved by the presence of the leaf springs 280U and 280D, it is desirable to attach the leaf springs 280U and 280D to the upper and lower surfaces of all the structural members 202. The leaf springs 280U and 280D are examples of pressing means, and may be configured by other elastic means.
(3) Example 3
This will be described with reference to FIGS.
In this example, in addition to the structural member 202, for example, the structural member 202 between the optical writing unit 104C and the optical writing unit 104M is viscoelastic between the structural member 202 and the optical writing unit 104M below the structural member 202. A vibration isolating rubber 29D is provided as a vibration isolating means for generating a normal force, and similarly, a vibration isolating rubber 29U similar to the anti-vibration rubber 29D is provided between the structural member 202 and the optical writing means 104C thereabove. Yes. Anti-vibration rubbers 29U and 29D are similarly provided between the optical writing means positioned above and below the other structural members 202, respectively.

  These vibration isolator rubbers 29U and 29D are of the same material shape as the rectangular plate anti-vibration rubber 29 having viscoelastic characteristics described in FIG. And affix them to the top and bottom surfaces. In FIG. 14, the base members 328K, 328C, 328M, and 328Y are omitted. According to this example, the above-described vibration mode is effectively suppressed by the vibration isolating action by the thermal conversion of the vibration energy by the vibration isolating means comprising the vibration isolating rubbers 29U and 29D.

  The anti-vibration rubbers 29U and 29D as the anti-vibration means can obtain the anti-vibration effect due to the viscosity even if the elastic force is set lower than the elastic suppression by the leaf springs 280U and 280D as the pressing means. Since it is possible, the force acting on the optical writing means 104K, 104C, 104M, and 104Y104 can be reduced, and deformation caused by the anti-vibration support can be suppressed, which is also effective in maintaining accuracy.

Also in this example, the anti-vibration rubbers 29U and 29D are also provided on the upper surface of the uppermost structural member 202 and the lower surface of the lowermost structural member 202 for the same reason as in the examples shown in FIGS. Is attached.
Further, the vibration isolating rubber 29U, 29D as the vibration isolating means is brought into contact with the base members 328K, 328C, 328M, 328Y or the optical writing means 104K, 104C, 104M, 104Y through an elastic member such as a leaf spring. For example, the adjusting means 130K, 130C, 130M, and 130Y can be functioned without requiring large deformation of the vibration-proof rubber, which is preferable.
(4) Example 4
This will be described with reference to FIGS.
As shown in FIG. 16, each of the plurality of structural members 202 in this example has vertical pieces 202a and 202b rising vertically at the left and right ends, and the left vertical piece 202a is fixed to the left side plate 22d by fastening means. ing. The vertical piece 202b on the right side (image forming cartridge side) is a vertical structural member that is provided in parallel with the arrangement direction of the plurality of optical writing units arranged in a superimposed manner and is substantially orthogonal to the respective structural members 202. It is connected and fixed to the stay 300.

  As the vertical stay 300, one having the same shape and size as the vertical stay 30 shown in FIG. 8 can be used. Accordingly, the constituent parts of the vertical stay 300 are denoted by the same reference numerals as the vertical stay 30, and are attached to the top plate 22e and the bottom plate 22f, and to the front plate 22a and the rear plate 22b. And a fixing hole 30c for fixing to the structural member 202 is formed around the opening 30d, and a slit-like opening 30d as an optical path of the light beam Lb is formed in the optical writing means 104K, Four are formed corresponding to the number of 104C, 104M, and 104Y.

  As shown in FIG. 17, the right vertical piece 202b of the structural member 202 is formed with a screw hole 202c at a position corresponding to the fixing hole 30c of the vertical stay 300. The structural member 202 and the vertical stay 300 are It is integrally fixed with a screw 210 ′ as a fastening means shown in FIG.

  In this example, the suppression of the surface vibration mode of the front side plate 22a and the rear side plate 22b is further strengthened by the presence of the vertical stay 300 as compared to the configuration of the structural member 202 alone. Moreover, since the horizontal structural member 202 and the vertical stay 300 are substantially orthogonal to each other, the sectional moment becomes very large, and a highly rigid structure having excellent bending rigidity is obtained. This improvement in bending rigidity reduces the effect reduction due to vibration in the structural member 2 itself in the vibration suppressing configuration by the leaf springs 280U and 280D as the pressing means and the vibration isolating rubbers 29U and 29D as the vibration isolating means. The vibration-proof function can be further enhanced by combining the vibration-proof structures.

  In the case of this example, each of the optical writing means 104K, 104C, 104M, and 104Y is arranged in a superposed manner in the direction of gravity and has a configuration corresponding thereto, so that the vertical stay 300 has its own weight and the weight of the structural member 202. Compared to the configuration in which the optical writing means is juxtaposed in the horizontal direction, the strength can be improved, the amount of deformation can be reduced, and the resonance mode can be eliminated. It is advantageous.

The vertical stay 300 is formed with the slit-shaped opening 30d as described above, but other than this, for the purpose of securing a cooling path and forming a mounting shape, the opening and the notch are not damaged so as not to impair the strength. May be provided. Further, in this example, the structural member 202 and the vertical stay 300 are fixed using the screw 210 as the fastening means. However, the present invention is not limited to this, and a metal material is integrally formed by welding or a mold material is used. Then, it can be integrally formed by injection molding.
[3] embodiments described below implementation form is obtained so as to prevent banding by using all or part of the configuration according to the example described so far.
(1) Example 1
This will be described with reference to FIG. [1] In the section of the first embodiment (5), the configuration in which the horizontal stay 25 is connected to the vertical stay 30 has been described with reference to FIGS. In the section [2] Second Embodiment (4), the configuration in which the structural member 202 is connected to the vertical stay 300 is described with reference to FIGS. In these examples, the vertical stay 30 and the vertical stay 300 are described as separate members having the same shape and size.

  In this example, as shown in FIG. 5, a vertical stay 30 connected to a horizontal stay 25 for partitioning a plurality of image forming cartridges, and a structural member 202 for partitioning a plurality of optical writing means as shown in FIG. The connected vertical stay 300 is shared by the same member. Specifically, as shown in FIGS. 18 and 19, an object to which the horizontal stay 25 is connected and an object to which the structural member 202 is connected are shown as the same vertical stay 30. Therefore, the vertical stay 30 corresponds to a common structural member in the present invention.

  In this example, a plurality of horizontal stays 25 for partitioning the image forming cartridges and a plurality of structural members 202 for partitioning the optical writing means are connected to a common vertical stay 30 so that the horizontal stays 25 and the vertical stays 30 are connected. The structural member 202 and the main body 22 are combined with each other to form an integrated structure, and the overall rigidity is synergistically increased, and banding can be prevented. Further, since the vertical stay 30 is commonly used as a reinforcing means for the plurality of structural members 202 and a reinforcing means for the plurality of horizontal stays 25, the configuration can be simplified and downsized.

In the example shown in FIG. 19, the left end portion of the structural member 202 does not reach the left side plate 22d, but this is for image formation such as electrical parts between the left side plate 22d and the left end portion of the structural member 202. This is due to the layout convenience of arranging the parts. Even in such a configuration, the front and rear direction of the structural member 202 is fixed to the front side plate 22a and the rear side plate 22b, respectively, which is effective in preventing banding. Depending on the layout, there may be a configuration in which the left side plate 22d and the left end portion of the structural member 202 are fixed as shown in FIG. In FIG. 19, the horizontal stay 25, the vertical stay 30, and the structural member 202 are shown by thick lines in order to schematically show that the structural member is an integral structure.
(2) Example 2
Referring to FIG. 1, the image forming cartridges 4, 5, 6, and 7 are partitioned by a structural member 25 that partitions the image forming cartridges. In contrast, in this example, the image forming means is housed in a casing separate from the image forming cartridge, and the image forming cartridge between the image forming cartridges having the same function as the structural member 25 is provided with the casing covering the image forming means. It was set as the partition member.

  Specifically, reference numeral 35 in FIG. 20 denotes a casing of the image forming means, which is schematically shown by a thick line. In this example, the image forming means configured in the casing 35 is, for example, a developing means including the developing roller 10K, the replenishing roller 11K, the rotating bodies 13K and 14K around the image forming cartridge 4.

  Here, the rotating bodies 13K and 14K are means for stirring the developer composed of toner and carrier, and the replenishing roller 11K is a roller for supplying the developer stirred by the rotating bodies 13K and 14K to the photoconductor 8K. The developing roller 10K is a roller that supplies toner to the photoreceptor 8K.

  The developing means including the developing roller 10K, the replenishing roller 11K, the rotating bodies 13K and 14K, etc. is a part of the image forming means, and the charging roller 9K and the cleaning blade 12K as image forming means provided on the image forming cartridge 4 side. The casing 35 that covers the developing means serves to effectively partition the image forming cartridge 4 and the image forming cartridge 5. Similarly, other image forming cartridges are partitioned by the casings 35 between the image forming cartridges.

  Since the charging roller 9K, the cleaning blade 12K, and the like provided in the image forming cartridge 4 include consumable parts that need to be replaced in a relatively short time, they are unitized as an image forming cartridge and detachable from the main body 22. On the other hand, the members such as the developing roller 10K, the replenishing roller 11K, and the rotating members 13K and 14K as developing means for supplying the toner to the photosensitive member 8K and performing the developing function can withstand repeated use over a relatively long period of time. If a means for replenishing from the outside is provided separately, there is no particular problem even if these are housed in the casing 35 and the casing 35 is fixedly and firmly attached to the main body 22. Therefore, the casing 35 can be firmly fixed to the main body 22. The same applies to the casings attached to the other image forming cartridges 5, 6, 7. Therefore, by using these casings 35 as partition members between the image forming cartridges, the structure can be strengthened and vibration of the image forming cartridges can be prevented.

  Further, the casing 35 has a roll shape surrounding the developing means, for example, the developing roller 10K, the replenishing roller 11K, the rotating bodies 13K, 14K, etc., and has a depth in the front-rear direction, and a front end in the longitudinal direction. Since the portion is fixed to the front plate 22a and the rear end portion is fixed to the rear plate 22b, the strength as an integral structure with the main body 22 is increased and the vibration prevention of the image forming cartridge is enhanced.

  These casings 35 are interposed between the image forming cartridges 4, 5, 6, 7, and serve to partition the image forming cartridges in the same manner as the structural member 25 and also cover the image forming means. Plays. Thus, in this example, the casing of the image forming means is also used as a structural member for partitioning the image forming cartridges, so that the configuration can be simplified and miniaturized compared to the case where the image forming cartridges are partitioned by the structural member 25. The occurrence of banding can be prevented as shown in the figure.

As a modified example of this example, as shown in FIG. 21, if a part of each casing 35 is extended and the extended part 35a is connected to the vertical stay 30 described in FIG. 5 or FIG. Can be increased. In the above example, the developing means is housed in the casing that partitions the image forming cartridges. However, the present invention is not limited to this, and the casing that partitions the image forming cartridges can be configured to house other image forming means. .
(3) Example 3
In the example described with reference to FIGS. 9 to 18, the optical writing units 104K, 104C, 104M, and 104Y are provided with the adjusting units 330K, 330C, 330M, and 330Y for adjusting the shift of the scanning line. However, these adjusting means 330K, 330C, 330M, and 330Y are provided outside the respective housings, which are cases in which the optical writing means are accommodated, and are configured to swing the respective housings. There was a difficulty that the member 202 could not be used together.

  In this example, by adopting a configuration in which the adjusting means for adjusting the shift of the scanning line can be accommodated in the housing, the housing itself is replaced with the structural member 202 for partitioning the optical writing means. It is what. Below, the example of the adjustment means which can be accommodated in the said housing is demonstrated.

  Assuming that the optical writing means is provided with adjusting means that can be housed in the housing and each optical writing means is represented by 104K ′, 104C ′, 104M ′, and 104Y ′, these have the same configuration. The adjusting means will be described.

  In FIG. 22, the housing of the optical writing means 104K is schematically shown by a rectangular frame indicated by reference numeral 104K. As already described, the polygon mirror 106K, the first fθ lens 108K, the folding mirrors 110K and 111K, and the like are provided in the housing.

  Of these members, as shown in FIGS. 23 and 24, in this example, the folding mirror 111K is otherwise supported with the one end 36 side in the longitudinal direction of the mirror being the direction corresponding to the main scanning direction of the light beam Lb. The end 37 side can be freely rotated by an arbitrary amount. By rotating in this way, the scanning line of the light beam Lb on the photosensitive member 8K is shifted in the sub-scanning direction at a position corresponding to the other end 37 in the main scanning direction, and the entire scanning line has, for example, an angle θ. Get the tilt. Further, the rotation holding means is configured to be held at the position after the rotation, and this is used as the adjustment means.

  In FIG. 25A, the surface on the one end 36 side of the folding mirror 111K is supported by the knife edge 38 so that it can be rotated while maintaining the angle of folding of the light beam by the mirror. The surface on the other end 37 side is pressed by an extensible spring 40 that is an elastic means, and the opposite surface is pressed by a moving member 41. In FIG. 25B illustrating the configuration around the moving member 41, the moving member 41 is a kind of nut screwed to a screw 43 that rotates integrally with the shaft of the motor 42. A groove 45 that is long in the axial direction is formed in the immediate part of the moving member 41, and a detent 44 is fitted in this groove 45 so as to be movable in the axial direction.

  In this example, such a knife edge 38, a spring 40, a moving member 41, a motor 42, a screw 43, a rotation stopper 44, and the like constitute a rotation holding means. With such a rotation holding means, It is an adjustment means. In such an adjusting means, by driving the motor 42, the folding mirror 111K can be rotated about the knife edge 38 as a fulcrum, and the position after the rotation can be maintained.

  Since the adjustment means as in this example is provided to be attached to the folding mirror 111K, it can be accommodated in the housing of the optical writing means 104K ′. If the adjusting means is configured in the optical writing means 104K ′, the housing of the optical writing means 104K ′ can be statically attached to the main body 22 as a whole. It can be replaced with the structural member 202 for writing means partitioning.

  The optical writing means 104K ′, 104C ′, 104M ′, and 104Y ′ shown in FIG. 26 are configured such that the adjusting means described with reference to FIGS. These optical writing means 104K ′, 104C ′, 104M ′, and 104Y ′ are configured such that each bottom plate 47 of each housing is appropriately larger or more rigid than a normal one, and the front end is the front side plate 22a and the rear end. The parts are respectively fixed to the rear side plate 22b. As described above, since a part of the housing serves as a structural member for partitioning the optical writing means, the structure by combining the members is simplified as compared with the examples of FIGS. 9 to 19 in which the structural member 202 is provided separately from the housing. And miniaturization can be achieved.

In the example shown in FIG. 27, each bottom plate 47 as a member for partitioning the optical writing means, which is a part of the housing constituting the optical writing means 104K ′, 104C ′, 104M ′, 104Y ′, has been described with reference to FIGS. According to the example, it is connected to the vertical stay 300. The vertical stay 300 has an upper end portion fixed to the top plate 22e, a lower end portion fixed to the bottom plate 22f, a front end portion fixed to the front side plate 22a, and a rear end portion fixed to the rear side plate 22b. Furthermore, as a modification, the vertical stay 300 may be configured to connect the structural member 25 shown in FIG.
(4) Example 4
This example is based on the configuration having the horizontal stay 25 described with reference to FIGS. This will be described with reference to FIG. In FIG. 28, the box-shaped frame in which the main body 22 of the image forming apparatus is configured includes a front side plate 22a, a rear side plate 22b, a right side plate 22c, a left side plate 22d, a top plate e, and a bottom plate 22f. In this box-shaped frame, a plurality of horizontal stays 25 as partitioning members for partitioning the image forming cartridges 4, 5, 6, and 7 are disposed in a superimposed manner. Image forming cartridges 4, 5, 6, 7 are provided from above so as to be partitioned by these horizontal stays 25.

  The axial directions of the photoconductors 8K, 8C, 8M, and 8Y in the image forming cartridges 4, 5, 6, and 7 are orthogonal to the front plate 22a, and the image forming cartridges are arranged along the axial direction of the photoconductors. In order to be detachable, a rectangular opening 50 that is long in the vertical direction is formed to allow the image forming cartridges 4, 5, 6, and 7 to pass therethrough. The front end and the front plate 22a are fixed to a screw 51, which is a fastening means, in such a manner that the front end of each horizontal stay 25 crosses the opening 50 in the left-right direction.

  In this example, the opening 50 for attaching / detaching the image forming cartridge formed on the front side plate 22a constituting the surface of the box-shaped frame is reinforced so as to be traversed by the horizontal stay 25 as a structural member for image forming cartridge partitioning. Therefore, it is possible to avoid a decrease in rigidity of the front side plate 22a and thus the entire box-shaped frame due to the formation of the opening 50, thereby preventing banding.

  A modification of this example will be described. In the example shown in FIG. 28, the opening 50 is one opening that communicates with each of the image forming cartridges 4, 5, 6, 7. In this example, one opening is made to correspond to one image forming cartridge instead of one opening like the opening 50. In FIG. 29, an opening formed for attaching / detaching the image forming cartridge 4 is denoted by reference numeral 54. Similarly, openings formed for the image forming cartridges 5, 6, and 7 are indicated by reference numerals 55, 56, and 57, respectively.

In this example, a part of the front side plate 22a remains in a rib shape between the adjacent openings 54, 55, 56, 57. After the front end portion of each horizontal stay 25 is overlapped with the portion remaining in the rib shape, the front end portion of the horizontal stay 25 is fixed to the front side plate 22d with screws 51 as fastening means at each position in the left-right direction. ing. In this configuration, the size of one opening is small, and the gap between the openings remains in a rib shape, so that the decrease in rigidity due to the formation of the opening is smaller than in the example described with reference to FIG. . In addition, since it is reinforced by each horizontal stay 25, the rigidity of the box-shaped frame is reduced and the effect of preventing banding is more remarkable.
(Five) Example 5
This example is based on the configuration having the horizontal stay 25 described with reference to FIGS. This will be described with reference to FIG. In FIG. 30, the box-shaped frame in which the main body 22 of the image forming apparatus is configured includes a front side plate 22a, a rear side plate 22b, a right side plate 22c, a left side plate 22d, a top plate e, and a bottom plate 22f. In this box-shaped frame, a plurality of horizontal stays 25 as partitioning members for partitioning the image forming cartridges 4, 5, 6, and 7 are disposed in a superimposed manner. Image forming cartridges 4, 5, 6, 7 are provided from above so as to be partitioned by these horizontal stays 25.

  In this example, the right side plate 22c is positioned on the direction orthogonal to the axial direction of the photoconductors 8K, 8C, 8M, and 8Y located in the image forming cartridges 4, 5, 6, and 7 in the horizontal plane. . The right side plate 22c is provided with the transfer belt 1 described with reference to FIG. Therefore, the entire right side plate 22c is constituted by a lid 58 surrounding the transfer belt 1, and the entire right side plate 22c can be opened and closed as a lid-like body while the transfer belt 1 is held.

  In order to make such a configuration that can be opened and closed, the lower portion of the lid 58 and the lower plate 22f are connected by a hinge or a fulcrum shaft (not shown). As shown in FIG. 30, under the state in which the lid 58 is opened, the portion of the right side plate 22c is completely opened, so that the image forming cartridge can be easily attached and detached using the opening on the right side plate side. FIG. 30 illustrates a state where the image forming cartridge 4 is taken out.

  FIG. 31 shows a modification. In this example, the image forming cartridges 4, 5, 6, and 7 are attached and detached from the left side plate 22d side. In the example described so far, the optical writing means 104K, 104C, 104M, 104Y and the optical writing means 104K ′, 104C ′, 104M ′, 104Y ′, the vertical stay 30 are arranged on the left side of the image forming cartridges 4, 5, 6, 7. , 300 and the like are disposed, and these become obstacles, and the image forming cartridge cannot be attached or detached from the left side plate 22d side.

  In this example, instead of these optical writing means 104K, 104C, 104M, 104Y and the optical writing means 104K ′, 104C ′, 104M ′, 104Y ′, a single flat box-shaped optical writing unit described later is used. Configured. This optical writing unit is denoted by reference numeral 100 in FIG. As shown in FIG. 31, the writing unit 100 is housed in a lid 59 composed mainly of the left side plate 22d. The lid 59 can be opened and closed with the rotation shaft 60 as a fulcrum. In the state where the lid 59 is opened as shown by a two-dot chain line in FIG. 31, an opening corresponding to the left side plate 22d is formed. The image forming cartridges 4, 5, 6, and 7 can be easily attached and detached through this opening.

In each of these examples, the side plate on the direction orthogonal to the axial direction of the photoconductor in the horizontal plane of the box-shaped frame is configured with a lid that can be opened and closed completely. 28 and 29, it is not necessary to form an opening in the front plate 22a that directly supports the image forming cartridge, so that the rigidity of the structure can be maintained and effective in preventing banding. .
(6) Example 6
This example relates to a configuration in which the optical writing means is configured as one box-shaped writing unit 100 as in the example described with reference to FIG. In the example shown in FIGS. 32 and 33, the writing unit 100 is fixed to the structure 102, and the front and rear end portions of the structure 102 are fixed to the front side plate 22a and the rear side plate 22b. As in the example described above, the image forming cartridges 4, 5, 6, 7 are arranged in an overlapping manner in the vertical direction and are fixed to the main body 22.

  The writing unit 100 has openings 100K, 100C, 100M, and 100Y for emitting the light beam Lb corresponding to the photoconductors 8K, 8C, 8M, and 8Y provided in the image forming cartridges 4, 5, 6, and 7, respectively. is doing. The writing unit 100 is held at a fixed distance from the photoconductors 8K, 8C, 8M, and 8Y, and an image is written by the light beam Lb.

As described above, when the optical writing unit is configured by one writing unit 100, positioning is easier than in the case where the optical writing unit is configured by four optical writing units 104K, 104C, 104M, and 104Y as described in FIG. Thus, the entire image forming apparatus can be reduced in size. Further, since the writing unit 100 has a single unit, it is possible to increase the strength, for example, by adding a reinforcing member for increasing the rigidity. If the writing unit has a flat configuration, the installation area of the image forming apparatus can be reduced.
(7) Example 7
This example relates to the configuration of the writing unit 100 described with reference to FIGS. FIG. 34A shows a state in which one box-shaped writing unit 100 is attached to the image forming apparatus. A polygon mirror 70 that is rotationally driven by a motor 72 is provided in the central portion to constitute a polygon scanner. The rotational axis direction of the polygon mirror 70 is orthogonal to the axial directions of the photoconductors 8K, 8C, 8M, 8Y and the like.

  Four light sources are provided at positions (not shown) of the writing unit 100, and each light source is modulated with cyan, magenta, yellow, and black image signals to form a light beam for writing, and the mirror of the polygon mirror 70. It is incident on four points on the surface. The scanning direction of the light beam by the polygon mirror 70 in the writing unit 100 is a direction orthogonal to the rotational axis direction of the polygon mirror 70, and the photoconductors 8K, 8C, 8M, and 8Y are arranged in the same direction as this scanning direction. Yes.

  When the black light beam is emitted from the polygon mirror 70, it is emitted from the opening 100K toward the photosensitive member 8K through the fθ lens 73, the mirrors 74 and 75, the long lens 76, and the mirror 77. When the cyan light beam is emitted from the polygon mirror 70, it is emitted from the opening 100 </ b> C toward the photoconductor 8 </ b> C through the fθ lens 73, mirrors 78 and 79, the long lens 80 and the mirror 81. When the light beam for magenta is emitted from the polygon mirror 70, it is emitted from the opening 100M toward the photoreceptor 8M through the fθ lens 83, the mirrors 84 and 85, the long lens 86, and the mirror 871. When the yellow light beam is emitted from the polygon mirror 70, it is emitted from the opening 100Y toward the photoreceptor 8Y via the fθ lens 83, the mirrors 88 and 89, the long lens 90, and the mirror 91. Each opening 100K, 100C, 100M, 100Y is covered with dustproof glass as shown in FIG. 34 (b).

As described above, since the scanning direction in the writing unit is the same as the arrangement direction of the photosensitive members, four units are arranged as in the optical writing units 104K, 104C, 104M, and 104Y shown in FIG. Compared to the configuration, it can be configured in a single box shape that is flat in the horizontal direction, and the installation area of the image forming apparatus can be reduced. Further, since the number of polygon scanners serving as heat sources can be reduced from four to one, the temperature rise inside the image forming apparatus can be suppressed to a low level.
(8) Example 8
This example relates to how to attach the writing unit 100 having the configuration shown in FIG. 34 to the image forming apparatus. In this example, as shown in FIGS. 35 and 36, a writing unit having a flat plate shape in accordance with the arrangement direction of the image forming cartridges 4, 5, 6, and 7 arranged in an overlapping manner in the vertical direction, that is, the vertical direction. A support structural member 92 is disposed. The structural members 92 are fixed to the front plate 22a, the rear plate 22b, the top plate 22e, and the bottom plate 22f, respectively.

Four pedestals 92a for attaching the writing unit 100 is formed in the structural member 92. The writing unit 100 is attached by bolts 94 as attachment means using these pedestals 92a. With such an attachment mode, the distance between the writing unit 100 and the photoconductors 8K, 8C, 8M, and 8Y is kept constant. In addition, it can also be set as the structure which does not provide the base 92a.

In this example, since the structural member 92 is integrally fixed to the front side plate 22a, the rear side plate 22b, the top plate 22e, the bottom plate 22f, and the like, the rigidity of the entire main body 22 is increased, and the writing unit 100 is attached to the structural member 92. It is also effective in preventing banding.
(Nine) Example 9
In the example shown in FIGS. 35 and 36, the structure 92 is usually made of metal, and the frame of the writing unit 100 is made of resin. Since the writing unit 100 incorporates a polygon scanner as a heat source, the writing unit 100 is thermally expanded as the temperature rises with scanning. The writing unit 100 has an end attached to the structure 92. When the writing unit 100 is thermally expanded, the structure 92 is also thermally expanded. However, since the frame and the structure 92 of the writing unit have different coefficients of thermal expansion due to the difference in material, the writing unit 92 is positioned at the end where it is attached. There is a possibility that the intermediate portion is distorted into a curved shape and deformed without being changed.

  For example, in FIG. 34, when the writing unit tries to extend in the vertical direction with the upper end and the lower end, which are attachment points to the structure, being suppressed, the vertical center of the writing unit 100 is separated from the photoconductor side. Curves in the direction. Then, for example, the mirror 77 is also displaced under the influence of this curved deformation, and the path of the light beam Lb is shifted by an angle β. Even if the shift of the angle β is a slight angle, it is enlarged at the position of the photosensitive member and becomes a large shift. Since such a deviation amount of the light beam Lb is different for each photoconductor, the overlapping state of each color at the time of forming a full-color image is disturbed and the image quality is deteriorated. In order to prevent such image quality disturbance, in this example, measures are taken so that the displacement of the writing unit 100 is minimized.

  In this example, the writing unit 100 is pressed and held on the structural member 92 via elastic members at both ends in the up and down direction, and the pressing holding unit has a space for movement of the writing unit 100 in the up and down direction.

  Specifically, as shown in FIG. 37, a hole 140 is formed in a portion of the mounting seat 100a formed at the upper end of the writing unit 100, and a bolt 94 is passed through the hole 140 through a washer 96 made of an elastic member. The tip of the bolt is screwed into the structural member 92. An extensible spring 95 is interposed between the structural member 92 and the mounting seat 100a. The diameter D of the hole 140 is larger than the diameter d of the bolt 94, and a clearance is provided so that the writing unit 100 can move in the vertical direction. The end of the writing unit 100 is also attached to the structural member 92 with the same configuration.

  With this configuration, when the spring light writing unit 100 that is an elastic member is thermally expanded, the light writing unit 100 can be displaced in the vertical direction within the range of the difference between the diameter D and the diameter d. Therefore, even if there is thermal expansion, the optical writing unit 100 does not distort in a curved shape as shown by a two-dot chain line in FIG. 37 and can extend in the vertical direction, so that the amount of displacement of the light beam Lb is kept small. It is done.

  FIG. 38 shows a modified example. In this example, a bolt 97 is screwed into a pedestal 92 a formed on the structural member 92, and a spring 98 as an elastic member is interposed between the mounting seat 100 a and the head of the bolt 94. I am letting. In this example as well, the hole 140 is made larger than the diameter of the bolt so that the writing unit 100 can be moved in the vertical direction when the writing unit 100 is thermally expanded.

According to these examples, the structural member 92 and the writing unit 100 are elastically fastened, and the burr at the time of thermal expansion of the writing unit 100 is secured. The resulting color unevenness will not occur.
(10) Example 10
As described with reference to FIGS. 35, 38, etc., when the writing unit 100 is attached to the structural member 92 with the bolt 94 via the elastic member only at the upper and lower end portions, with a space in the vertical direction, Since the length of the expanded portion is absorbed in the vertical direction, the curved distortion is eliminated. However, the vertical displacement is not lost. This example aims to further reduce the amount of displacement in the vertical direction.

  In this example, as shown in FIGS. 38 and 39, the intermediate position in the vertical direction of the writing unit 100 is point-supported by pins 99 at two locations in the horizontal direction with respect to the structural member 92.

By doing so, the amount of vertical displacement of the writing unit 100 due to thermal expansion is divided into two parts, the upper half and the lower half. Therefore, color unevenness due to thermal expansion can be further reduced.
(Eleven) Example 11
This example is similar to the example shown in FIG. 19, and the image forming cartridges 4, 5, 6, 7 described in FIGS. 1 to 6 are added to the structural member 92 described in FIGS. A horizontal stay 25 for partitioning is connected. In this example, the horizontal stay 25 effective for preventing vibration of the image forming cartridge is connected to the structural member 92 for supporting the writing unit 100 arranged in a direction orthogonal to the horizontal stay 25. The rigidity of the entire 22 is improved, which is effective for preventing banding.
(Twelve) Example 12
This example is a modification of the example described with reference to FIGS. 40 and 41, and is an application example to the image forming apparatus of the type described with reference to FIGS. In such an image forming apparatus, photoconductors 8K ″, 8C ″, 8M ″, and 8Y ″ are supported in advance as shown in FIG. On the other hand, as shown in FIGS. 43 (a), (b), (c), and (d), the image forming cartridges 4 ", 5", 6 ", and 7" do not support the photosensitive member. When such an image forming cartridge is mounted on the main body 22, a part of the image forming means, for example, as shown in FIG. 50, the ring 10C "-1, 10C" -2 or the like is in contact with the photoreceptor 8C ". Become.

Even in this type of image forming apparatus, as shown in FIG. 42, the structural member 92 described with reference to FIGS. 35 to 39 and the like is divided into the image forming cartridges 4 ", 5", 6 ", and 7". By connecting the horizontal stays 25, it is possible to increase the rigidity of the main body 22 and prevent banding.
(Thirteen) Example 13
The guide portions 27K, 27C, 27M, and 27Y described in FIG. 2 are applied to the image forming cartridge described in FIGS.
(Fourteen) Example 14
The leaf springs 28U and 28D as the pressing means described with reference to FIGS. 3, 4, and 6 are applied to the image forming cartridge described with reference to FIGS.
( 15 ) Example 15
4 and 7, the anti-vibration rubber 29 as the anti-vibration means for generating a viscoelastic pressing force between the horizontal stay 25 and the image forming cartridge is the horizontal stay 25 described with reference to FIGS. Is provided.

  In each of the examples described above, the description has centered on the configuration that is the feature, but by combining the configuration that is the feature with other examples as much as possible, the anti-vibration function can be further enhanced synergistically.

1 (a) is front view of the main part of the images forming apparatus, FIG. 1 (b) is a fragmentary side view of the image forming apparatus. 2 (a) is front view of the main part of the images forming apparatus, FIG. 2 (b) is a fragmentary side view of the image forming apparatus. 3 (a) is front view of the main part of the images forming apparatus, FIG. 3 (b) is a fragmentary side view of the image forming apparatus. 4 (a) is front view of the main part of the images forming apparatus, FIG. 4 (b) is a fragmentary side view of the image forming apparatus. 5 (a) is front view of the main part of the images forming apparatus, FIG. 5 (b) is a fragmentary side view of the image forming apparatus. It is a perspective view of a horizontal stay. It is a perspective view of an anti-vibration rubber. It is a perspective view of a vertical stay. It is a partial front view of the images forming apparatus. It is a plan view of the images forming apparatus. It is a side view of the images forming apparatus. It is a partial front view of the images forming apparatus. It is a fragmentary side view of the images forming apparatus. It is a partial front view of the images forming apparatus. It is a fragmentary side view of the images forming apparatus. It is a partial front view of the images forming apparatus. It is a fragmentary side view of the images forming apparatus. It is a partial front view of the images forming apparatus. It is a partial front view of the images forming apparatus. It is a partial front view of the images forming apparatus. It is a partial front view of the images forming apparatus. It is a principal part front view of the image forming cartridge explaining the rocking | fluctuation direction of a mirror. It is a perspective view explaining the principle of the inclination adjustment of scanning by rotation of a mirror. It is a principal part front view explaining the principle of the inclination adjustment of scanning by rotation of a mirror. FIG. 25A is a perspective view illustrating the entire configuration of the rotation holding means for the mirror, and FIG. 25B is a partial cross-sectional view illustrating the main part of the rotation holding means for the mirror. It is a partial front view of the images forming apparatus. It is a partial front view of the images forming apparatus. It is a perspective view of a main part explaining the opening formed in the front side board. It is a perspective view of a main part explaining the opening formed in the front side board. It is a perspective view of the main body which made the cover structure which can open and close a part of main body. It is a perspective view of the main body which made the cover structure which can open and close a part of main body. 1 is a partial cross-sectional plan view of an image forming apparatus illustrating an example of the present invention. 1 is a front view of a main part of an image forming apparatus illustrating an example of the present invention. FIG. 34A is a partial cross-sectional view illustrating the structure of the writing unit and the positional relationship of the writing unit with the photoconductor, and FIG. 34B is a partial cross-sectional view of the writing unit illustrating the dust-proof glass in the opening. . It is a partial cross-sectional plan view of the images forming apparatus. It is a partial front view of the images forming apparatus. It is a fragmentary sectional view of the principal part explaining the attachment part of the optical writing unit. It is a fragmentary sectional view of the principal part explaining the attachment part of the optical writing unit. It is the perspective view explaining the attachment state of the optical writing unit. It is a partial cross-sectional plan view of the images forming apparatus. 1 is a front view of a main part of an image forming apparatus. FIG. 2 is a front view of a main part of an image forming apparatus of a type that supports a photoconductor on the main body side. 43A is a front view of a black image forming cartridge that does not support a photoconductor, FIG. 43B is a front view of a cyan image forming cartridge that does not support a photoconductor, and FIG. FIG. 43D is a front view of a magenta image forming cartridge that does not support a photoconductor, and FIG. 43D is a front view of a yellow image forming cartridge that does not support a photoconductor. It is a front view explaining the principal part of the conventional image forming apparatus which can apply this invention. 1 is an external perspective view of a conventional image forming apparatus to which the present invention can be applied. It is JJ arrow sectional drawing in FIG. It is a top view of an image forming cartridge. It is a side view of an image forming cartridge. FIG. 3 is a diagram illustrating a state where an image forming cartridge is mounted on a main body. It is a figure explaining the space | interval control member which controls the space | interval of a developing roller and a photoreceptor. FIG. 2 is a front view showing a part of an image forming apparatus of a type in which a photoconductor is previously supported on the main body side. 52A is a front view of a black image forming cartridge that does not support a photoconductor, FIG. 52B is a front view of a cyan image forming cartridge that does not support a photoconductor, and FIG. FIG. 52D is a front view of a magenta image forming cartridge that does not support a photoconductor, and FIG. 52D is a front view of a yellow image forming cartridge that does not support a photoconductor. FIG. 53A is a diagram illustrating a state in which vertical vibration is generated in the image forming cartridge, and FIG. 53B is a diagram illustrating a state in which twisting direction vibration is generated in the image forming cartridge. It is QQ arrow sectional drawing in FIG. It is WW arrow sectional drawing in FIG. FIG. 56A is a view for explaining the upper and lower vibration modes, and FIG. 56B is a view for explaining the torsional vibration mode.

Explanation of symbols

4, 5, 6, 7 Image forming cartridge
3 0, 300 Vertical stay 100 Writing unit

Claims (2)

A main body configured in a box-shaped structure composed of a front plate, a rear plate, a right plate, a left plate, a top plate, and a bottom plate ;
A plurality of image forming cartridges in which a photoconductor is supported in advance and arranged to be superposed on the main body and detachably mounted;
A plurality of image writing devices for irradiating the photosensitive member with a light beam;
An image forming apparatus for forming an image in the mounted state of even capital said plurality of image forming cartridge to said main body,
A vertical stay provided between the image writing device and the plurality of image forming cartridges, and a plate-shaped structural member for partitioning the image writing device;
The vertical stay is fixed to the front plate, the rear plate, the top plate, and the bottom plate,
The structural members for partitioning the image writing device are respectively fixed to the front side plate, the rear side plate, and the vertical stay,
An image forming apparatus, wherein a light beam emitted from the image writing apparatus passes through an opening provided in the vertical stay and performs writing on the photosensitive member. The image forming apparatus according to claim 1.
2. The image forming apparatus according to claim 1, wherein the opening has a minimum width and length allowing the light beam to pass therethrough .

Images