JP2017107095A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus that has an exposure device and a heater arranged below a photoreceptor, and can efficiently heat the photoreceptor with the heater while suppressing toner from dropping onto the exposure device.SOLUTION: An image forming apparatus 100 comprises: a photoreceptor 1; a photoreceptor holding part 7 that is arranged below the photoreceptor 1 and holds a unit 6 including the photoreceptor 1; an exposure device 3 that is arranged below the photoreceptor 1 and exposes the photoreceptor 1 to light; a heater 9 that is arranged below the photoreceptor 1; and a partition wall 10 that is arranged below the photoreceptor 1 and above the exposure device 3 and heater 9. The partition wall 10 is provided with a plurality of holes 11 that permit passage of air heated by the heater 9.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an image forming apparatus such as a copying machine, a facsimile, and a printer using an electrophotographic system.

  In an electrophotographic image forming apparatus, the surface of a photoreceptor (electrophotographic photoreceptor) is uniformly charged, and the surface of the charged photoreceptor is exposed according to image information, so that the surface of the photoreceptor is exposed. An electrostatic latent image is formed. The electrostatic latent image formed on the surface of the photoreceptor is supplied with toner by a developing device and developed (visualized) as a toner image. The toner image formed on the surface of the photoreceptor is transferred to a recording material such as paper directly or via an intermediate transfer member. The recording material onto which the toner image has been transferred is heated and pressed by a fixing device, and the toner image is fixed thereon, and then discharged to the outside of the image forming apparatus.

  In such an image forming apparatus, an exposure device such as a laser scanner may be disposed below the photosensitive member or the developing device. For example, in an intermediate transfer type image forming apparatus in which a toner image is primarily transferred from a photosensitive member to an intermediate transfer member, and a toner image is secondarily transferred from the intermediate transfer member to a recording material, an image forming unit having a photosensitive member and a developing device. May be disposed below the intermediate transfer member. Such an arrangement is advantageous in that the developing device and the exposure device can be separated from the fixing device across the intermediate transfer member, and the influence of the developing device and the exposure device on the heat generated by the fixing device can be reduced. For example, in the case of such an arrangement, the exposure apparatus is arranged below the photoconductor and the developing apparatus as described above.

  However, in an electrophotographic image forming apparatus, toner may be scattered from the photosensitive member or the developing device during image formation. When the exposure device is disposed below the photosensitive member or the developing device, the toner scattered from the photosensitive member or the developing device falls on the light transmission portion of the exposure device (for example, a glass window that transmits the laser of the laser scanner). There are things to do. If toner exceeding the allowable amount is deposited on the light transmitting portion, the light cannot be transmitted through the light transmitting portion and the electrostatic latent image cannot be properly formed on the surface of the photosensitive member. There is. As a result, image defects such as white stripes are caused.

  On the other hand, an electrophotographic image forming apparatus is configured to warm the photoreceptor so that the temperature (surface temperature) of the photoreceptor is maintained at a predetermined temperature or higher even during non-image formation such as when the image forming apparatus is turned off. Sometimes. This is because when the temperature of the photoconductor becomes a predetermined temperature or less, the discharge product adhering to the surface of the photoconductor absorbs moisture, so that an image that seems to have disappeared due to the flow of an image that should be output appears. This is because an image defect is likely to occur. There are the following methods for warming the photoreceptor. The ambient temperature around the heater is warmed by the heater, and the heated air is moved upward by natural convection to increase the ambient temperature around the photoreceptor, and the temperature of the photoreceptor is maintained at a predetermined temperature or more by the increase in the ambient temperature. That's it. This method has an advantage that the photosensitive member can be heated with a relatively simple configuration. When this method is used, the heater needs to be disposed below the photoconductor.

  Here, in the configuration in which the exposure device is arranged below the photosensitive member and the developing device as described above, in order to suppress the fall of the toner on the light transmitting portion of the exposure device, the exposure with the photosensitive member and the developing device is performed. It is conceivable to provide a partition such as a sheet metal between the apparatus.

  Incidentally, as a prior art relating to a configuration in which a photosensitive member is heated by a heater, there is a method in which a shielding member moves between a charger and a photosensitive member when the heater is turned off (Patent Document 1).

JP 2007-72212 A

  As described above, in the configuration in which the exposure device is disposed below the photosensitive member or the developing device, the toner on the light transmission portion of the exposure device is provided by providing a partition between the photosensitive member, the developing device, and the exposure device. It is thought that the fall of can be suppressed.

  However, as described above, in the configuration in which the air heated by the heater is moved upward to heat the photoconductor, the heater needs to be disposed below the photoconductor. In addition, a holding member that holds a unit including the photoconductor may be disposed below the photoconductor.

  For this reason, when the partition wall or the holding member is disposed between the photosensitive member and the heater, the air heated by the heater does not reach the periphery of the photosensitive member sufficiently, and the photosensitive member cannot be sufficiently heated. In addition, the effect of suppressing the image flow cannot be obtained sufficiently.

  Accordingly, an object of the present invention is to provide an image in which the photosensitive member can be efficiently heated by the heater while suppressing the dropping of the toner onto the exposing device in a configuration in which the exposure device and the heater are arranged below the photosensitive member. A forming apparatus is provided.

  The above object is achieved by the image forming apparatus according to the present invention. In summary, the present invention relates to a photoconductor, a photoconductor holding unit that is arranged below the photoconductor and holds a unit including the photoconductor, and an exposure that is arranged below the photoconductor to expose the photoconductor. An apparatus, a heater disposed below the photoreceptor, and a partition disposed below the photoreceptor and above the exposure device and the heater, and the partition is heated by the heater. The image forming apparatus is provided with a plurality of holes that allow passage of air.

  According to the present invention, in the configuration in which the exposure device and the heater are disposed below the photoconductor, the photoconductor can be efficiently warmed by the heater while suppressing the toner from dropping onto the exposure device.

1 is a cross-sectional view of a main part of an image forming apparatus. 1 is a perspective view of a main part of an image forming apparatus. FIG. 4 is a perspective view of a main part of the image forming apparatus with a developing device removed. It is a perspective view of a partition member. It is a top view of a partition member viewed from the photoreceptor side. It is sectional drawing of the principal part of the other example of an image forming apparatus. It is a perspective view of the principal part of the other example of an image forming apparatus. It is a perspective view of the principal part of the other example of an image forming apparatus. It is a perspective view of a cartridge holding member. It is an expanded sectional view of a cartridge holding member. FIG. 10 is a cross-sectional view of a main part of still another example of the image forming apparatus. FIG. 10 is a perspective view of a main part of still another example of the image forming apparatus. FIG. 10 is a perspective view of a main part of still another example of the image forming apparatus. It is a perspective view of the other example of a cartridge holding member. It is an expanded sectional view of other examples of a cartridge holding member.

  The image forming apparatus according to the present invention will be described below in more detail with reference to the drawings.

[Example 1]
1. Image Forming Apparatus FIG. 1 is a cross-sectional view of a main part of an image forming apparatus 100 according to the present embodiment. The image forming apparatus 100 includes a rotatable drum-type photoconductor (photosensitive drum) 1. The photoreceptor 1 is driven to rotate in the direction of arrow R1 (clockwise) in the drawing. The surface of the rotating photoreceptor 1 is uniformly charged by a charging roller 2 that is a roller-type charging member as a charging unit. The charged surface of the photosensitive member 1 is scanned and exposed with light L corresponding to image information by an exposure device 3 as an exposure unit. As a result, an electrostatic latent image (electrostatic image) is formed on the photoreceptor 1. In this embodiment, the exposure apparatus 3 is a laser scanner that irradiates the photosensitive member 1 with laser light L. The housing 3b includes a laser light source, a scanning optical system, and the like, and the housing 3b transmits laser light. An allowed light transmission part (light irradiation part) 3a is provided. In the present embodiment, the light transmission part 3a is configured by a glass window.

  The electrostatic latent image formed on the photoreceptor 1 is developed (visualized) as a toner image by supplying toner as a developer by the developing device 4. In this embodiment, the toner charged with the same polarity as the charged polarity (negative polarity in this embodiment) of the photosensitive member 1 is exposed to the exposed portion where the absolute value of the potential is reduced by exposure after being uniformly charged. Adhere to. The developing device 4 includes a developing container (developing frame) 4 a that stores toner, and a developing sleeve 4 b that serves as a developer carrying member that conveys the toner to a portion (developing unit) facing the photosensitive member 1. The developing sleeve 4b is rotatably supported by the developing container 4a.

  The toner image formed on the photosensitive member 1 is transferred (primary transfer) to an intermediate transfer belt (not shown), which is an intermediate transfer member composed of, for example, an endless belt as a transfer target. At this time, a primary transfer bias (opposite charging polarity) of the toner at the time of development is applied to a primary transfer member (not shown) disposed opposite to the photoreceptor 1 via the intermediate transfer belt. Is applied. The toner image primarily transferred to the intermediate transfer belt is then secondarily transferred to a recording material such as paper. The recording material onto which the toner image has been secondarily transferred is heated and pressed by a fixing device (not shown) to fix the toner image thereon, and then is discharged outside the image forming apparatus 100. The Further, the toner remaining on the photoconductor 1 after the transfer of the toner image from the photoconductor 1 to the transfer target is removed and collected from the photoconductor 1 by a cleaning blade 5 as a cleaning unit.

  In this embodiment, the photosensitive member 1, the charging roller 2, and the cleaning blade 5 are integrated by a cartridge container (cartridge frame) 6 a and can be attached to and detached from the apparatus main body 110 of the image forming apparatus 100. 6 is constituted. The photoreceptor 1 and the charging roller 2 are rotatably supported by the cartridge container 6a, and the cleaning blade 5 is in contact with the photoreceptor 1 and fixed to the cartridge container 6a. In this embodiment, the developing device 4 is detachable from the apparatus main body 110 separately from the photosensitive cartridge 6.

  In this embodiment, the photoreceptor 1 and the developing device 4 are disposed below an intermediate transfer belt as a transfer target. In this embodiment, the exposure device 3 is disposed below the photoreceptor 1 and the developing device 4.

2. Attachment / Removal of Photosensitive Cartridge and Developing Device Next, attachment / detachment of the photosensitive cartridge 6 and the developing device 4 with respect to the apparatus main body 110 will be described with reference to FIGS. FIG. 2 is a perspective view of a main part of the image forming apparatus 100 of the present embodiment. FIG. 3 is a perspective view of a main part of the image forming apparatus 100 of the present embodiment in a state where the developing device 4 is detached from the apparatus main body 110.

  In this case, it is assumed that the front side of the paper in FIG. 1 is the front (front) of the image forming apparatus 100 and the rear side of the paper in FIG. 1 is the rear (back) of the image forming apparatus 100. The front-rear direction of the image forming apparatus 100 is substantially parallel to the longitudinal direction (rotation axis direction) of the photoreceptor 1. Further, the horizontal direction of the image forming apparatus 100 refers to the horizontal direction when the image forming apparatus 100 is viewed from the front. Further, “upper” and “lower” mean upper and lower in the direction of gravity, but do not mean just above and below, but include above and below the horizontal plane passing through the target element and position. Further, the position of the photosensitive member 1 and the developing device 4 or the positional relationship with respect to the photosensitive member 1 and the developing device 4 refers to the main parts of the photosensitive member 1 and the developing device 4. The main part of the photoreceptor 1 includes an image forming area (area in which a toner image can be formed), and the main part of the developing device 4 includes an area in the developing container 4a and the toner on the developing sleeve 4b. However, an accompanying element such as a drive transmission unit may not be included. The same applies to other embodiments described later.

  In this embodiment, as described above, the photosensitive member cartridge 6 and the developing device 4 are separate, and can be individually attached to and detached (inserted / removed) from the apparatus main body 110.

  In this embodiment, the attaching / detaching direction of the photosensitive cartridge 6 with respect to the apparatus main body 110 is the front-rear direction of the image forming apparatus 100. The photoreceptor cartridge 6 can be detached from the apparatus main body 110 by being pulled out in the direction of arrow A in FIG. Conversely, the photosensitive cartridge 6 can be mounted on the apparatus main body 110 by being inserted in a direction opposite to the arrow A direction in FIG. When the photosensitive cartridge 6 is attached to and detached from the apparatus main body 110, the developing device 4 moves away from the photosensitive member 1 in the direction of arrow B in FIGS. 1 and 2 (a direction substantially perpendicular to the longitudinal direction of the photosensitive member 1). Direction). As a result, a clearance between the photosensitive member cartridge 6 and the developing device 4 that enables the movement of the photosensitive member cartridge 6 is ensured.

  When the photoconductor cartridge 6 is attached to or detached from the apparatus main body 110, the photoconductor cartridge 6 is supported by a cartridge rail 7 as a photoconductor holding portion that holds a unit including the photoconductor 1, and moves in the front-rear direction in a guided state. . The photosensitive cartridge 6 is supported and guided by the cartridge rail 7 by engaging the cartridge holding and receiving portions 6b formed at the left and right ends of the bottom of the cartridge container 6a with the cartridge rail 7. When the photoconductor cartridge 6 is inserted to a predetermined position inside the apparatus main body 110, the photoconductor cartridge 6 is moved in a floating direction from the bottom of the cartridge rail 7 as shown in FIG. 1, and is moved to a photoconductor cartridge positioning portion (not shown). The position is determined by being restrained. Although detailed description is omitted, a photosensitive cartridge positioning portion such as a hole is provided on the front and rear side plates of the image forming apparatus 100, and a convex portion provided on the photosensitive cartridge 6 is fitted into this hole to perform positioning. .

  In this embodiment, the attaching / detaching direction of the developing device 4 with respect to the apparatus main body 110 is the front-rear direction of the image forming apparatus 100 as in the case of the photosensitive member cartridge 6. The developing device 4 can be detached from the apparatus main body 110 by being pulled out in the direction of arrow A in FIG. Conversely, the developing device 4 can be attached to the apparatus main body 110 by being inserted in a direction opposite to the arrow A direction in FIG. When the developing device 4 is attached to and detached from the apparatus main body 110, the developing device 4 is moved in the front-rear direction at a position moved in the direction of arrow B in FIGS. As a result, a clearance between the developing device 4 and the photosensitive cartridge 6 that enables the developing device 4 to move is secured.

  When the developing device 4 is attached to or detached from the apparatus main body 110, the developing device 4 is supported by the developing rail 8 as a developing device holding unit that holds the developing device 4 and moves in the front-rear direction in a guided state. The developing device 4 is supported and guided by the developing rail 8 when the developing holding and receiving portions 4c formed at the left and right ends of the bottom of the developing container 4a are engaged with the developing rail 8. When the developing device 4 is inserted to a predetermined position inside the apparatus main body 110, the developing device 4 can move in the direction opposite to the arrow B direction in FIGS. In this embodiment, the developing rail 8 is movable along the arrow B direction. As shown in FIG. 2, the developing device 4 is provided with an abutting member 4d for maintaining a space (SD gap) between the photosensitive member 1 and the developing sleeve 4b. As described above, when the developing device 4 can move in the direction opposite to the direction of the arrow B, the developing device 4 is moved until the abutting member 4d abuts against the photosensitive member 1, and between the photosensitive member 1 and the developing sleeve 4b. The predetermined interval is set, and the developing device 4 is positioned.

  In this embodiment, the photosensitive cartridge 6 and the developing device 4 can be individually replaced. However, the photosensitive cartridge 6 and the developing device 4 may be integrated to form a process cartridge. .

3. Heater In the present embodiment, a heater 9 is disposed below the photosensitive member cartridge 6 as a heating means for heating the photosensitive member 1. In this embodiment, the heater 9 is disposed almost directly below the photoreceptor 1. Thus, it is preferable that at least a part (all in the present embodiment) of the heater 9 is disposed in a region overlapping with the photosensitive member 1 when viewed in the substantially gravity direction. The heater 9 is configured to maintain the temperature (surface temperature) of the photoreceptor 1 at a predetermined temperature or higher as follows. The heater 9 raises the ambient temperature around it. The air heated by the heater 9 moves upward of the heater 9 by natural convection as shown by an arrow C in FIG. The ambient air around the photoreceptor 1 is raised by the moved air. As a result, the temperature of the photoreceptor 1 is maintained at a predetermined temperature or higher. In this embodiment, the heater 9 is configured to have a heating wire, and energization control to the heating wire is set so as to maintain the temperature of the photosensitive member 1 at a predetermined temperature or higher. By maintaining the temperature of the photosensitive member 1 at a predetermined temperature or higher, image flow can be suppressed.

4). In this embodiment, the exposure device 3 (more specifically, the light transmission portion 3a) is disposed below the photosensitive member 1 and the developing device 4. In such a configuration, as described above, the toner scattered from the photosensitive member 1 and the developing device 4 falls on the light transmission portion 3a of the exposure device 3 and accumulates, whereby light is transmitted through the light transmission portion 3a. In some cases, the electrostatic latent image cannot be properly formed on the photosensitive member 1 due to the inability to do so. As a result, image defects such as white stripes are caused.

  Therefore, in this embodiment, the image forming apparatus 100 includes a partition member 10 that is disposed below the photoreceptor cartridge 6 and above the heater 9 and separates the photoreceptor 1 from the exposure device 3. As will be described in detail later, in this embodiment, the partition member 10 extends below the developing device 4 and also separates the developing device 4 from the exposure device 4.

  However, if the partition member 10 is provided between the photosensitive member cartridge 6 and the heater 9, the air heated by the heater does not sufficiently reach the periphery of the photosensitive member 1, and the photosensitive member 1 can be sufficiently heated. Therefore, there is a concern that the effect of suppressing the image flow cannot be sufficiently obtained. In addition, by disposing the heater 9 below the partition member 10, the toner can be prevented from dropping to the heater 9.

  Therefore, in the present embodiment, the partition member 10 is provided with a plurality of heater holes 11 that allow passage of air heated by the heater 9.

  Hereinafter, with reference to FIGS. 1-5, the partition member 10 in a present Example is demonstrated in more detail. FIG. 4 is a perspective view of the partition member 10. FIG. 5 is a top view of the partition member 10 viewed from the photosensitive cartridge 6 side.

  In this embodiment, the partition member 10 is a plate-like member that extends from below the photosensitive member cartridge 6 to below the developing device 4. In this embodiment, the plate-like partition member 10 functions as a partition that separates the photosensitive member 1 and the developing device 4 from the exposure device 3. In the present embodiment, the partition member 10 is disposed substantially horizontally. In this embodiment, the partition member 10 is formed by molding a synthetic resin.

  The partition member 10 has a plurality of heater holes 11 that allow passage of air heated by the heater 9. Further, the partition member 10 has an exposure hole 12 that allows the laser light L emitted from the exposure apparatus 3 to pass therethrough.

  In the present embodiment, each of the plurality of heater holes 11 is a square hole having a substantially square shape in a vertical direction and having a side of 5 mm in plan view. However, the size and shape of the heater hole 11 are not limited to those of the present embodiment. The toner scattered from the photosensitive member 1 and the developing device 4 can be appropriately determined based on experiments so that it is difficult to enter the exposure device 3 side and the air heated by the heater 9 easily passes. Although not limited to this, the opening width of the heater hole 11 on the upper surface of the partition wall member 10 (for example, the longest width among the sides facing each other if a rectangle, the diameter if a circle) is about 1 mm or more and 10 mm or less. Typically, about 3 mm to 5 mm is preferable.

  The plurality of heater holes 11 are arranged so that the photosensitive member 1 can be efficiently heated by the heater 9. In FIG. 5, a region where the photosensitive member 1 is projected onto the partition member 10 along the substantially gravitational direction is indicated by a broken line 10a, and a region where the developing device 4 is projected onto the partition member 10 along the substantially gravitational direction is indicated by a broken line 10b. Show. Note that these regions 10 a and 10 b indicate the approximate positions of the main parts of the photoreceptor 1 and the developing device 4.

  It is preferable that at least a part of the plurality of heater holes 11 is disposed substantially directly below the photoreceptor 1. That is, it is preferable that at least a part of the plurality of heater holes 11 is disposed in a region 10a that overlaps the photoconductor 1 when viewed in a substantially gravitational direction. In the present embodiment, all of the plurality of heater holes 11 are disposed almost directly below the photoreceptor 1. Further, as described above, in the present embodiment, the heater 9 is also disposed almost directly below the photosensitive member 1, so that at least a part of the plurality of heater holes 11 is disposed substantially directly above the heater 9. Yes. Further, in the present embodiment, the plurality of heater holes 11 are arranged over substantially the entire length in the longitudinal direction of the photoreceptor 1 so that heat can be sufficiently transmitted in the longitudinal direction of the photoreceptor 1. The heater 9 may be arranged at any position in the longitudinal direction of the photoconductor 1 in the region 10a overlapping the photoconductor 1, but is preferably arranged at least at the center and further at both ends. , May be provided in substantially the entire region. In particular, in the present embodiment, the plurality of heater holes 11 are arranged in three rows substantially parallel to the longitudinal direction of the photoreceptor 1. In this embodiment, the intervals between the adjacent heater holes 11 in the longitudinal direction of the photosensitive member 1 and the direction substantially orthogonal to the longitudinal direction are substantially equal.

  On the other hand, the developing device 4 is generally desired to suppress the temperature rise. Therefore, it is preferable that the plurality of heater holes 11 are not provided in the region 10b that overlaps the developing device 4 when viewed in the substantially gravitational direction. However, when it is not necessary to suppress the temperature rise of the developing device 4, at least one heater hole 11 may be disposed in the region 10b.

  The partition member 10 separates the photosensitive member 1 and the developing device 4 from the exposure device 3 in the vertical direction so that the toner scattered from the photosensitive member 1 and the developing device 4 is placed on the light transmission portion window 3 a of the exposure device 3. Suppresses falling and accumulation.

  The toner deposited on the light transmission part 3a of the exposure apparatus 3 floats inside the image forming apparatus 100 due to airflow inside the image forming apparatus 100 or natural convection due to temperature change. When the floating toner falls on the light transmission part 3a of the exposure device 3 and becomes dirty on the light transmission part 3a, the photosensitive member 1 cannot be properly exposed due to the dirt, and the output image is white streaks. The image is defective. There is a method of providing a dustproof shutter as a countermeasure against contamination of the light transmitting portion 3a due to the fall of toner on the light transmitting portion 3a of the exposure apparatus 3. However, the dustproof shutter is open to irradiate the laser during image formation. Since the toner accumulated as described above floats again during image formation, the dust-proof shutter alone is not sufficient as a measure against the white streaks.

  As described above, according to the present embodiment, by providing the partition member 10 provided with the plurality of heater holes 11, the heater 9 is heated while suppressing the toner falling on the light transmission portion 3a of the exposure apparatus 3. The generated air can be efficiently moved to the periphery of the photoreceptor 1. As a result, it is possible to simultaneously suppress image defects caused by contamination of the light transmission part 3a of the exposure device 3 such as white stripes, and image flow caused by insufficient heating of the photosensitive member 1.

[Example 2]
Next, another embodiment of the present invention will be described. The basic configuration and operation of the image forming apparatus of this embodiment are the same as those of the first embodiment. Therefore, in the image forming apparatus according to the present embodiment, elements having the same or corresponding functions or configurations as those of the image forming apparatus according to the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  FIG. 6 is a cross-sectional view of a main part of the image forming apparatus 100 of the present embodiment. FIG. 7 is a perspective view of a main part of the image forming apparatus 100 of the present embodiment. FIG. 8 is a perspective view of a main part of the image forming apparatus 100 of the present embodiment, and schematically shows a state in which the photosensitive member 1 is irradiated with the laser light L.

  In the present embodiment, the function of the partition member 10 in the first embodiment is provided by the cartridge holding member 20 that holds the photosensitive cartridge 6 and the development holding member 30 that holds the developing device 4. Thus, in this embodiment, the partition wall and the photosensitive member holding part are integrally formed. In this embodiment, the partition wall and the developing device holding part are also integrally formed. That is, in this embodiment, the partition wall, both the photosensitive member holding portion and the developing device holding portion are integrally formed. However, in this embodiment, the part integrated with the photosensitive member holding part of the partition and the part integrated with the developing device holding part of the partition are divided. This will be described in more detail below.

  The cartridge holding member 20 includes a plate-like cartridge partition wall portion 21 and a cartridge rail portion 22 that protrudes upward from the cartridge partition wall portion 21. The cartridge partition wall 21 functions as a partition that separates the photosensitive member 1 and the exposure device 3 from each other in the same manner as the partition member 10 in the first embodiment. In the present embodiment, the cartridge partition wall 21 is disposed substantially horizontally. Similar to the cartridge rail 7 in the first embodiment, the cartridge rail portion 22 has a function of a photosensitive member holding portion that guides the photosensitive member cartridge 6 when the photosensitive member cartridge 6 is attached or detached. In this embodiment, the cartridge rail portions 22 are provided at the left and right ends of the cartridge partition wall 21 so as to sandwich the cartridge holding and receiving portions 6b provided at the left and right ends of the bottom of the photosensitive cartridge 6 from both the left and right sides. Yes. The planar portion of the cartridge partition wall 21 between the cartridge rail portions 22 at both ends mainly has a function of a partition that vertically separates the photosensitive cartridge 6 from the exposure device 3. In this embodiment, the cartridge holding member 20 is formed by molding a synthetic resin.

  In this embodiment, when the photoconductor cartridge 6 is attached to or detached from the apparatus main body 110, it moves on the cartridge partition wall 21 in the front-rear direction while being guided by the cartridge rail portion 22. Further, the photosensitive cartridge 6 inserted to a predetermined position inside the apparatus main body 110 is moved in a floating direction from the cartridge partition wall 21 and is positioned by the photosensitive cartridge positioning unit as in the first embodiment.

  The development holding member 30 includes a plate-shaped development partition wall portion 31 and a development rail portion 32 that protrudes upward from the development partition wall portion 31. The developing partition wall 31 functions as a partition that separates the developing device 4 and the exposure device 3 from the partition member 10 in the first embodiment. In the present embodiment, the developing partition wall 31 is disposed substantially horizontally. The developing rail portion 32 has a function of a developing device holding portion that guides the developing device 4 when the developing device 4 is attached and detached, like the developing rail 8 in the first embodiment. In the present embodiment, the developing rails 32 are provided at the left and right ends of the developing partition wall 31 so as to sandwich the development holding receivers 4c provided at the left and right ends of the bottom of the developing device 4 from both the left and right sides. The flat portion of the developing partition wall 31 between the developing rail portions 32 at both ends mainly has a function of a partition that vertically separates the developing device 4 and the exposure device 3. In this embodiment, the development holding member 30 is formed by molding a synthetic resin.

  In this embodiment, when the developing device 4 is attached to and detached from the apparatus main body 110, the developing device 4 moves in the front-rear direction on the developing partition wall 31 while being guided by the developing rail portion 32. In this embodiment, the development holding member 30 is movable along the direction of arrow B in FIGS. When the photosensitive cartridge 6 and the developing device 4 are attached / detached, the developing device 4 is moved in the arrow B direction as in the first embodiment. Further, the developing device 4 inserted to a predetermined position inside the apparatus main body 110 is moved and positioned in the direction opposite to the arrow B direction until the abutting member 4d abuts against the photoreceptor 1.

  At the left end portion of the cartridge partition wall portion 21, an extension portion 21 a extending to the left side from the left cartridge rail portion 22 is provided. Further, an extension portion 31 a extending to the right side of the right development rail portion 32 is provided at the right end portion of the development partition wall portion 31. Then, with the developing device 4 positioned with respect to the photoreceptor 1 as described above, the extension portions 21a and 31a face each other with a predetermined clearance. This clearance is set to be sufficiently small so that the fall of the toner can be sufficiently suppressed. In the present embodiment, a notch 21 b is provided at the center in the front-rear direction of the extension 21 a of the cartridge partition wall 21. The gap between the notch 21b and the extension 31a of the developing partition wall 31 has the function of the exposure hole 12 in the partition member 10 of the first embodiment. The function of the exposure hole 12 in the partition wall member 10 of the first embodiment is such that the clearance between the cartridge partition wall 21 and the development partition wall 31 is the minimum clearance that allows the laser light L emitted from the exposure device 3 to pass. May be provided.

  The heater 9 is disposed below the cartridge partition wall 21, that is, below the cartridge holding member 20.

  In this embodiment, the cartridge holding member 20 and the development holding member 30 are separate components, but they may be integrated.

  As described above, in this embodiment, the function of the partition member 10 in Embodiment 1 can be given to the cartridge holding member 20 and the development holding member 30 to reduce the number of parts. As a result, the cross-sectional size in the vertical direction of the image forming apparatus 100 can be reduced, and the cost can be reduced.

  Further, in this embodiment, the function of the partition wall member 10 in the first embodiment is given to the cartridge holding member 20, so that the heater 9 is replaced with the photosensitive member as compared with the first embodiment (FIG. 1) as shown in FIG. It becomes possible to approach the cartridge 6. Therefore, the photoreceptor 1 can be warmed more efficiently, and the output of the heater 9 can be reduced. As a result, there are also merit of energy saving due to reduction of power consumption, etc., and merit of cost reduction by being able to use a heater 9 with lower output.

  FIG. 9 is a perspective view of the cartridge holding member 20 in the present embodiment. FIG. 10 is an enlarged cross-sectional view of the cartridge holding member 20 in the present embodiment.

  The cartridge partition wall 21 of the cartridge holding member 20 has a plurality of heater holes 23 that allow passage of air heated by the heater. In the present embodiment, each of the plurality of heater holes 23 is a square hole having a substantially rectangular shape in plan view on the upper surface 21c and the lower surface 21d of the cartridge partition wall 21 (in this embodiment, the upper surface 21c side is A substantially square shape and a substantially rectangular shape on the lower surface 21d side). In this embodiment, the area of the opening of the heater hole 23 is different between the upper surface 21 c and the lower surface 21 d of the cartridge partition wall 21. As shown in FIG. 10, in this embodiment, the areas of the openings of the heater holes 23 on the upper surface 21c and the lower surface 21d of the cartridge partition wall 21 are as follows. That is, when the area of the opening on the upper surface 21c is S1, and the area of the opening on the lower surface 21d is S2, the shape of the heater hole 23 is set so that S1 <S2.

  In this embodiment, the shape of the heater hole 23 is a square hole shape in which the shape of the opening is substantially rectangular in plan view on both the upper surface 21c and the lower surface 21d, but is not limited thereto. If formed so as to satisfy the relationship of S1 <S2, either or both of the shapes of the openings on the upper surface 21c and the lower surface 21d of the heater hole 23 are shapes other than a rectangle, for example, a triangle, a pentagon or more polygon, It may be circular, oval, elliptical, or the like.

  If S1 is too large, toner falling from the photoreceptor 1 and the developing device 4 will pass through the heater hole 23 and reach the exposure device 3. Further, since the relationship of S1 <S2 is established, the interval between the heater holes 23 is affected by the size of S2. For this reason, if S2 is too large, it is necessary to reduce the number of heater holes 23, and it is difficult to efficiently heat the photosensitive member 1 because the air heated by the heater 9 is blocked by the cartridge partition wall 21. It is done. Therefore, the upper limit value of S2 can be appropriately set based on experiments or the like according to the output of the heater 9, the target temperature of the photoreceptor 1, and the like. Similarly to the upper limit value of S2, the lower limit value of S1 can be set as appropriate based on experiments or the like according to the output of the heater 9, the target temperature of the photoreceptor 1, and the like. In some cases, such as when the cartridge holding member 20 is a resin-molded part, the size is limited due to its mass productivity. Therefore, a lower limit value may be set due to manufacturing problems. Although not limited to this, the opening width of the heater hole 23 on the upper surface 21c of the cartridge partition wall 21 is preferably about the same as that of the first embodiment.

  Further, the arrangement of the plurality of heater holes 23 in the present embodiment is substantially the same as the arrangement of the heater holes 11 of the partition wall member 10 in the first embodiment. However, in this embodiment, the plurality of heater holes 23 are arranged in four rows substantially parallel to the longitudinal direction of the photosensitive member 1.

  As described above, in this embodiment, by changing the cross-sectional shape of the heater hole 23 in the vertical direction, the air warmed by the heater 9 easily passes, and the toner falling from the photosensitive member 1 and the developing device 4 passes. It has a difficult shape. In particular, in this embodiment, the area of the opening of the heater hole 23 is relatively small on the upper surface 21c of the cartridge partition wall 21 and relatively large on the lower surface 21d.

  Here, as indicated by an arrow D in FIG. 6, one of the generation sources of the toner scattered inside the apparatus main body 110 is the developing sleeve 4 b of the developing device 4. Therefore, the toner is scattered from the developing sleeve 4b side to the photosensitive member 1 side. On the contrary, there is almost no scattering of toner from the cleaning blade 5 side with respect to the vertical line passing through the rotation center of the photosensitive member 1. Therefore, the effect of suppressing the fall of the toner can be improved by setting the cross-sectional shape of the heater hole 23 (the cross-sectional shape substantially perpendicular to the longitudinal direction of the photoreceptor 1).

  In the present embodiment, as shown in FIG. 10, the sectional shape of the heater hole 23 is as follows. First, the inner surface on the left side (side closer to the developing device 4) is inclined with respect to the upper surface 21c so as to approach the developing device 4 from the upper surface 21c side to the lower surface 21d side of the cartridge partition wall 21. That is, the inner surface of the heater hole 23 on the vertical surface side from the upper surface side to the lower surface of the cartridge partition wall 21 in the direction substantially perpendicular to the vertical surface passing through the position (developing unit) where the developer is supplied to the photosensitive member 1. As it goes to the side, it is inclined with respect to the upper surface so as to approach the vertical surface. On the other hand, the inner surface on the right side (the side farther from the developing device 4) has a shape extending from the upper surface 21c to the lower surface 21d of the cartridge partition wall 21 substantially perpendicular to the upper surface 21c. As described above, considering that there is a lot of toner scattering from the developing sleeve 4b side, the toner will be scattered along the path shown by arrow E in FIG. By making the cross-sectional shape of the heater hole 23 widen only on the developing sleeve 4b side, the toner scattered from the photosensitive member 1 and the developing device 4 is unlikely to fall into the heater hole 23 and efficiently passes to the exposure device 3. The toner can be prevented from dropping.

  Further, for example, the shape of the heater hole 23 on the developing sleeve 4b side with respect to the vertical line passing through the rotation center of the photoreceptor 1 can be made different from the shape of the heater hole 23 on the cleaning blade 5 side with respect to the vertical line. . In this case, for example, the area of the opening in the upper surface 21c of the heater hole 23 on the developing sleeve 4b side can be made smaller than that on the cleaning blade 5 side.

  As described above, according to the present embodiment, the same effects as those of the first embodiment can be obtained. Further, in this embodiment, the cartridge holding member 20 and the development holding member 30 have a partition function, so that the cross-sectional size can be reduced and the cost can be reduced. In addition, by making the shape of the heater hole 23 an asymmetric shape, it is possible to more efficiently suppress the toner from falling onto the exposure device 3.

[Example 3]
Next, another embodiment of the present invention will be described. The basic configuration and operation of the image forming apparatus of the present embodiment are the same as those of the first and second embodiments. Therefore, in the image forming apparatus of the present embodiment, elements having the same or corresponding functions or configurations as those of the image forming apparatuses of Embodiments 1 and 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  FIG. 11 is a cross-sectional view of a main part of the image forming apparatus 100 of the present embodiment. FIG. 12 is a perspective view of a main part of the image forming apparatus 100 of the present embodiment. FIG. 13 is a perspective view of a main part of the image forming apparatus 100 of the present embodiment, and schematically shows a state in which the photosensitive member 1 is irradiated with the laser light L. FIG. 14 is a perspective view of the cartridge holding member 20 in the present embodiment. FIG. 15 is an enlarged cross-sectional view of the cartridge holding member 20 in the present embodiment.

  In the present embodiment, as in the second embodiment, the cartridge holding member 20 and the development holding member 30 have the function of the partition member 10 in the first embodiment. Since the configuration of the development holding member 30 in the present embodiment is the same as that of the second embodiment, detailed description thereof is omitted. The configuration of the cartridge holding member 20 in the present embodiment is substantially the same as that of the second embodiment, except that the shape of the heater hole 23 and a shielding portion 24 described later are provided.

  The cartridge holding member 20 in the present embodiment has a cartridge partition wall portion 21 and a cartridge rail portion 22 as in the second embodiment. Further, the cartridge partition wall 21 of the cartridge holding member 20 in the present embodiment has a plurality of heater holes 23. In the present embodiment, each of the plurality of heater holes 23 is a rectangular hole that is substantially rectangular in a plan view (in this embodiment, a rectangle that is long in the longitudinal direction of the photosensitive member 1) and is substantially linear in the vertical direction. In the present embodiment, as in the second embodiment, the plurality of heater holes 23 are arranged in four rows substantially parallel to the longitudinal direction of the photoreceptor 1.

  The cartridge holding member 20 in this embodiment has a shielding portion 24 that protrudes upward from the upper surface 21 c of the cartridge partition wall portion 21. In the present embodiment, the shielding portion 24 includes a wall portion 24a extending from the upper surface 21c in a substantially vertical direction, and an eaves portion 24b extending from the front end portion of the wall portion 24a to the right side in a substantially right angle direction. In this embodiment, the cartridge holding member 20 is formed by molding a synthetic resin.

  The wall portion 24 a is erected adjacent to the left ridge line of each of the plurality of heater holes 23. In this embodiment, the wall portions 24 corresponding to the plurality of heater holes 23 arranged in the longitudinal direction of the photosensitive member 1 are integrally connected.

  The eaves portion 24b is provided so as to overlap with at least a part of the heater hole 23 when viewed in a substantially gravity direction. In the present embodiment, the eaves portion 24 b is provided so as to overlap with the substantially half on the left side of the heater hole 23 when viewed in the substantially gravity direction. Further, in this embodiment, the eaves portions 24b corresponding to the plurality of heater holes 23 arranged in the longitudinal direction of the photosensitive member 1 are integrally connected. However, in this embodiment, the integrally connected eaves 24b are formed with slits 24c at portions overlapping with the gaps between adjacent heater holes 23 in the longitudinal direction of the photosensitive member 1 when viewed in the direction of gravity. Has been.

  In this embodiment, when the photosensitive cartridge 6 is attached to and detached from the apparatus main body 110, the photosensitive cartridge 6 moves in the front-rear direction on the eaves portion 24 b of the shielding portion 24 while being guided by the cartridge rail portion 22. Further, the photosensitive cartridge 6 inserted to a predetermined position inside the apparatus main body 110 is moved in a floating direction from the eaves portion 24b of the shielding portion 24, and is positioned by the photosensitive cartridge positioning portion as in the first embodiment. .

  The heater 9 is disposed below the cartridge partition wall 21, that is, below the cartridge holding member 20.

  Here, in the present embodiment, each of the wall portion 24a and the eaves portion 24b has a linear shape. In this embodiment, the wall 24a is disposed substantially perpendicular to the upper surface 21c of the cartridge partition wall 21, and the eaves 24b is disposed substantially perpendicular to the wall 24a. However, the shape and arrangement angle of the wall portion 24a and the eaves portion 24b are not limited to those of the present embodiment. The effect of blocking the toner scattered from the photosensitive member 1 and the developing device 4 from entering the heater hole 23 is obtained, and the air heated by the heater 9 is prevented from moving to the periphery of the photosensitive member 1 more than an allowable amount. As long as it does not exist, it can be arbitrarily set based on experiments.

  For example, the shielding part 24 may have only a part corresponding to the wall part 24a in the present embodiment. However, it is preferable that at least a part of the shielding part 24 is provided so as to overlap with the opening part on the upper surface 21c of the heater hole 23 adjacent to the shielding part when viewed in the substantially gravity direction. For example, the shielding part 24 may have a configuration in which a wall corresponding to the wall part 24 a in the present embodiment is provided to be inclined toward the heater hole 23. That is, the shape of the wall projecting upward from the upper surface 21c of the cartridge partition wall 21 may be a straight line, a curved line, or a combination of a plurality of kinds.

  Further, in this embodiment, the wall portion 24a and the eaves portion 24b corresponding to the plurality of heater holes 23 arranged in the longitudinal direction of the photosensitive member 1 are connected to simplify the configuration and provide the slit 24c. It promotes the movement of warmed air. However, the present invention is not limited to this, and an individual shielding portion 24 may be provided in each heater hole 23. In this embodiment, the wall portion 24 a of the shielding portion 24 is provided in contact with the ridgeline of the heater hole 23 (almost flush with the inner surface of the heater hole 23), but the shielding portion 24 is provided in the heater hole 23. Alternatively, it may be provided at a predetermined interval. The fact that the shielding portion 24 is provided adjacent to the corresponding heater hole 23 is provided in contact with or close to the heater hole 23 so as to at least partially prevent the toner from entering the heater hole 23. It means that

  In the present embodiment, the heater hole 23 is a rectangular hole having a substantially rectangular shape in plan view. Although this shape can be said to be a shape that is relatively efficient in terms of suppression of toner dropping to the exposure device 3 and heat transfer from the heater 9, the shape of the heater hole 23 is limited as in the previous embodiments. It is not something.

  In this embodiment, as shown in FIG. 15, the cross-sectional shape of the air passage formed by the heater hole 23, the wall portion 24a, and the eaves portion 24b (the cross-sectional shape substantially perpendicular to the longitudinal direction of the photosensitive member 1) is crank. It becomes a shape. Therefore, the toner scattered from the photoreceptor 1 and the developing device 4 is difficult to enter the exposure device 3 side through this passage. Therefore, the area of the opening in the upper surface 21c of the heater hole 23 can be made relatively large. Further, as in the second embodiment, it is not necessary to reduce the area of the opening on the upper surface 21c side by making the area of the opening of the heater hole 23 different between the upper surface 21c and the lower surface 21d of the cartridge partition wall 21. Therefore, the air heated by the heater 9 can efficiently pass through the passage, and the air heated by the heater 9 is moved around the photoreceptor 1 more efficiently than in the first and second embodiments. Can be made. As a result, the thermal conductivity is improved, the output of the heater 9 can be reduced, and energy saving and cost reduction can be achieved.

  In this embodiment, as shown in FIG. 15, the wall 24 a and the eaves 24 b are provided on the left side of the heater hole 23 (the side closer to the developing device 4). That is, in the direction substantially perpendicular to the vertical plane passing through the position (developing section) where the developer is supplied to the photoreceptor 1, the shielding section 24 is on the vertical plane side of the heater hole 23 adjacent to the shielding section 24. It is provided adjacent to the ridgeline. Therefore, as shown by an arrow D in FIG. 15, it is possible to efficiently block the toner scattered from the developing sleeve 4b side, and it is possible to efficiently prevent the toner from dropping to the exposure apparatus 3 side through the heater hole 23. Can be suppressed.

  As described above, according to this embodiment, the same effects as those of Embodiments 1 and 2 can be obtained. Further, in the present embodiment, by providing the shielding portion 24, it is possible to more efficiently suppress the toner from dropping onto the exposure apparatus 3. In addition, the heater hole 23 and the shielding portion 24 form an air passage having a crank-shaped cross section, thereby reducing the necessity of reducing the cross-sectional area at a part of the hole and reducing the heat of the heater 9 to the photosensitive member 1. Can be communicated efficiently.

[Others]
As mentioned above, although this invention was demonstrated according to the specific Example, this invention is not limited to the above-mentioned Example.

  For example, the shape of the heater hole described in the second embodiment and the shielding portion described in the third embodiment may be applied to the heater hole of the first embodiment. Further, the shape of the heater hole described in the second embodiment (the cross-sectional shape changes in the vertical direction) can be applied to at least a part of the plurality of heaters. Similarly, the shielding part described in the third embodiment can be provided for at least a part of the plurality of heater holes.

  In the above-described embodiments, the case where the unit including the photosensitive member, the developing device, or the process cartridge can be easily attached to and detached from the apparatus main body of the image forming apparatus has been described. However, the present invention is not limited to this, and the unit and developing device including the photosensitive member may be fixed so as not to be easily attached to and detached from the member corresponding to the holding unit in the above-described embodiment.

  Further, the partition member described in the first embodiment may be provided with only a portion corresponding to the cartridge partition wall in the second and third embodiments so as to separate the photosensitive member and the exposure apparatus.

  In the above-described embodiment, the heater is provided below the photosensitive member and above the exposure device. However, the present invention can be applied if the exposure device and the heater are arranged below the photosensitive member. . If the heater can be arranged depending on the configuration of the exposure apparatus, the heater may be arranged at substantially the same height as the exposure apparatus or below the exposure apparatus.

DESCRIPTION OF SYMBOLS 1 Photoconductor 3 Exposure apparatus 4 Developing apparatus 7 Cartridge rail (photoconductor holding part)
8 Development rail (developing device holder)
9 Heater 10 Partition member (partition wall)
20 Cartridge holding member 21 Cartridge partition (partition)
22 Cartridge rail part (photoreceptor holding part)
24 Shield 30 Development Device Holding Member 31 Development Partition (Partition)
32 Development rail section (developing device holding section)

Claims (15)

A photoreceptor,
A photoconductor holding unit arranged below the photoconductor to hold a unit including the photoconductor;
An exposure device disposed below the photoconductor to expose the photoconductor;
A heater disposed below the photoreceptor;
A partition wall disposed below the photoconductor and above the exposure device and the heater;
Have
The image forming apparatus according to claim 1, wherein the partition is provided with a plurality of holes that allow passage of air heated by the heater.   The image forming apparatus according to claim 1, wherein the heater is disposed below the photoconductor and above the exposure apparatus.   3. The image forming apparatus according to claim 1, wherein when viewed in a substantially gravitational direction, at least a part of the plurality of holes is disposed in a region overlapping with the photosensitive member.   The image forming apparatus according to claim 1, wherein the partition wall and the photosensitive member holding portion are integrally formed. A developing device for supplying a developer to the photoreceptor;
A developing device holding part that is disposed below the developing device and holds the developing device;
Have
The partition is disposed below both the photoreceptor and the developing device,
3. The device according to claim 1, wherein when viewed in a substantially gravitational direction, at least a part of the plurality of holes is disposed in a region overlapping with the photosensitive member and is not disposed in a region overlapping with the developing device. The image forming apparatus described.   The partition wall and the photosensitive member holding part are integrally formed, or both the partition wall and the photosensitive member holding part and the developing device holding part are integrally formed. Item 6. The image forming apparatus according to Item 5.   The partition, the photosensitive member holding portion, and the developing device holding portion are integrally formed, a portion of the partition integrated with the photosensitive member holding portion, and the developing device holding portion of the partition The image forming apparatus according to claim 6, wherein the integrated part is divided.   The relationship of S1 <S2 is satisfied, where S1 is the area of the opening on the upper surface of at least a part of the plurality of holes, and S2 is the area of the opening on the lower surface. The image forming apparatus according to claim 7.   In the direction substantially perpendicular to the vertical plane passing through the position where the developer is supplied to the photoreceptor, at least a part of the inner surface on the vertical plane side of the plurality of holes extends from the upper surface side to the lower surface side of the partition wall. The image forming apparatus according to claim 8, wherein the image forming apparatus is inclined with respect to the upper surface so as to approach the vertical surface as it goes.   The image according to claim 1, wherein an upper surface of the partition wall is provided with a shielding portion protruding upward adjacent to at least a part of the plurality of holes. Forming equipment.   11. The image according to claim 10, wherein when viewed in a substantially gravity direction, at least a part of the shielding part is provided so as to overlap with an opening part on the upper surface of the hole adjacent to the shielding part. Forming equipment.   The shielding portion is provided adjacent to a ridge line on the vertical surface side of the hole adjacent to the shielding portion in a direction substantially orthogonal to a vertical surface passing through a position where the developer is supplied to the photoreceptor. The image forming apparatus according to claim 10, wherein the image forming apparatus is an image forming apparatus.   The image forming apparatus according to claim 1, wherein when viewed in a substantially gravitational direction, at least a part of the heater is disposed in a region overlapping with the photoconductor.   The image forming apparatus according to claim 1, wherein the unit including the photoconductor is detachable from the photoconductor holder.   The image forming apparatus according to claim 5, wherein the developing device is detachable from the developing device holding unit.

Images