JP2012103578A - Support fixing structure for processing means, image forming apparatus, process cartridge, and developing device equipped with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a support fixing structure for processing means free from damage thereto and able to be disassembled easily, and an image forming apparatus, a process cartridge and a developing device, which have this structure.SOLUTION: The support fixing structure includes: a frame body 11d rotatably supporting a photoreceptor drum 7; a bearing member 80a supporting a charging roller 8; a compression spring 71 used for energizing the charging roller 8 against the photoreceptor drum 7; and a support fixing part 11f slidably supporting the bearing member 80a parallel to the energizing direction of the compression spring 71. The bearing member 80a is movable between a first position in which the charging roller 8 is brought into contact with the photoreceptor drum 7 and a second position in which the charging roller 8 is separated from the photoreceptor drum 7 against the energizing force of the compression spring 71. When the bearing member 80a is in the first position, the support fixing part 11f restricts the separation of the bearing member 80a and when the bearing member 80a is in the second position, the bearing member 80a is separated from the support fixing part 11f and can be detached from the support fixing part 11f.

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine and a printer, and a process cartridge and a developing device used therefor, which have a support fixing structure for process means.

  2. Description of the Related Art Conventionally, in an image forming apparatus in which process means acting on an image carrier is integrally formed as a cartridge, and the cartridge is detachably mounted, the cartridge in which the developer has been consumed is disassembled, replaced, and commercialized again. . For this reason, parts that are used in the process cartridge are required to be easily disassembled.

  In the process cartridge described in Patent Document 1, the bearing member that rotatably supports the process means (charging roller) is supported in a state of being prevented from being removed from the frame. For this reason, when removing the bearing member from the portion of the frame body that has been secured, it has been necessary to elastically deform the frame body (the portion that has been secured) and expand it to remove the bearing member from the frame body.

  In the process cartridge described in Patent Document 2, as a method of easily disassembling the parts of the process means, a difficultly disassembled part (charging roller) provided on the frame holding the image carrier is replaced with another part (cleaning blade). It is assembled to the frame integrally. As a result, the parts that are difficult to disassemble can be removed integrally with other parts, and disassembly becomes easy.

  In the process cartridge described in Patent Document 3, as a method for easily disassembling the parts (charging roller) of the process means, a guide groove that is long in the radial direction of the image carrier is formed on a part of the frame that holds the image carrier. Provided. The guide groove also serves as a bearing for the charging roller and rotatably supports the charging roller. An attachment / detachment opening for assembling and removing the charging roller in a part of the guide groove is provided.

Japanese Patent Laid-Open No. 11-311934 (FIG. 6) Japanese Patent Laid-Open No. 8-146693 (FIGS. 5 and 13) JP-A-7-319244 (FIG. 1)

  However, in Patent Document 1, the charging roller cannot be removed without removing the image carrier. Further, it is necessary to elastically deform and widen the frame body (the portion that has been prevented from being removed) and to remove the bearing member from the frame body, which may cause whitening or breakage of the frame body (the portion that has been prevented from being removed). Further, it is necessary to put a tool or the like in a narrow space between the roller portion and the shaft portion at both ends in the longitudinal direction of the charging roller and remove the charging roller, which may damage the charging roller.

  In Patent Document 2, as in Patent Document 1, the charging roller cannot be removed unless the image carrier is removed. In Patent Document 3, since the structure around the guide groove is thin, the strength is weak and there is a risk of breakage. In addition, it has been difficult to stably press the charging roller to the image carrier during image formation.

  SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a structure for supporting and fixing a process means, an image forming apparatus, a process cartridge, and a developing apparatus having the process means that can be easily disassembled without fear of damage. .

In order to solve the above problems, typical structures of a support and fixing structure for a process means, an image forming apparatus, a process cartridge, and a developing apparatus according to the present invention include a frame that rotatably supports an image carrier that carries a toner image. Process means acting on the image carrier, a support member supporting the process means,
An urging means for urging the process means to the image carrier; and a support fixing portion provided on the frame body and slidably supporting the support member in parallel with the urging direction of the urging means. And the support member has a first position for bringing the process means into contact with the image carrier, and a second position for separating the process means from the image carrier against the biasing force of the biasing means. When the support member is in the first position, and the support fixing portion regulates the removal of the support member, and the support member is in the second position. The support member is detached from the support fixing portion, and the support member is removable from the support fixing portion.

  According to the present invention, the developing device and the process cartridge can be easily disassembled without being damaged.

It is a perspective view of the support fixation structure of the bearing member which concerns on 1st Embodiment. 1 is a schematic cross-sectional view of an electrophotographic image forming apparatus according to a first embodiment. It is a typical sectional view of a process cartridge concerning a 1st embodiment. FIG. 3 is a perspective view of assembly and disassembly of the drum unit according to the first embodiment. It is sectional drawing of the support fixation structure of the bearing member which concerns on 1st Embodiment. It is explanatory drawing of the support fixation structure of the bearing member which concerns on 2nd Embodiment. It is explanatory drawing of the support fixation structure of the bearing member which concerns on 2nd Embodiment.

[First embodiment]
A first embodiment of a support and fixing structure of a process means, an image forming apparatus, a process cartridge, and a developing apparatus according to the present invention will be described with reference to the drawings. FIG. 2 is a configuration diagram of the image forming apparatus of the present embodiment. FIG. 3 is a configuration diagram of the process cartridge according to the present embodiment.

  As shown in FIGS. 2 and 3, the image forming apparatus A according to the present embodiment has a process cartridge B in a detachable manner. The image forming apparatus A irradiates information light based on image information from an optical system 1 serving as optical means onto a drum-shaped photosensitive drum 7 charged by a charging roller (process means) 8, and causes electrostatic latent image on the photosensitive drum 7. Form an image. The electrostatic latent image is developed with a developer (hereinafter referred to as toner) by a developing unit (developing device) 10 to form a toner image.

  On the other hand, in synchronism with the formation of the toner image, the recording medium (for example, recording paper, OHP sheet, cloth, etc.) 2 is separated and fed one by one from the cassette 3a by the pickup roller 3b and the pressure contact member 3c that is in pressure contact therewith. The fed recording medium 2 is conveyed to a transfer section T where the photosensitive drum 7 of the process cartridge B and the transfer roller 4 as a transfer unit face each other. The recording medium 2 conveyed to the transfer portion T is transferred with the toner image formed on the photosensitive drum 7 by the transfer roller 4 to which voltage is applied, and is conveyed to the fixing device 5. The fixing device 5 includes a driving roller 5a and a heater 5b, and fixes the transferred toner image by applying heat and pressure to the passing recording medium 2. The recording medium 2 on which the toner image has been fixed is conveyed by the discharge roller 3d and discharged to the discharge unit 6 through the reverse conveyance path. The transfer residual toner remaining on the photosensitive drum 7 without being transferred to the recording medium 2 is collected by the cleaning blade 11a into the removed toner storage portion 11c.

(Process cartridge B)
As shown in FIG. 3, the process cartridge B includes a photosensitive drum (image carrier) 7 and at least one process means. Here, the process means acts on the image carrier. For example, a charging unit (charging roller 8) for charging the photosensitive drum 7, a developing unit (developing unit 10) for developing the electrostatic latent image formed on the photosensitive drum 7, and a toner for cleaning the toner remaining on the photosensitive drum 7 are cleaned. There is a cleaning means (cleaning blade 11a).

  The process cartridge B according to the present embodiment includes a developing unit 10 that supports the photosensitive drum 7 rotatably, an image carrier support frame 11d in which a cleaning blade 11a and a charging roller 8 are incorporated, and a developing roller 10d. is doing.

(Drum unit 11)
FIG. 4 is a schematic perspective view of assembly and disassembly of the drum unit 11 according to this embodiment. As shown in FIG. 4, the drum unit 11 includes a photosensitive drum 7, a charging roller 8, a cleaning blade 11a, and an image carrier support frame 11d, and constitutes a part of the process cartridge B.

  The photosensitive drum 7 has an image carrier gear 50 at one end and a flange 51 at the other end. The image carrier gear 50 includes a coupling 40, a shaft 52, and a drive transmission gear 41 that are integrated. The coupling 40 is a drive transmission unit from the image forming apparatus main body to the process cartridge B. The drive transmission gear 41 transmits drive to the developing roller 10d. The flange 51 has a support hole 53.

  At one end of the photosensitive drum 7, a bearing 60 is coupled to the image carrier support frame 11d by fixing means such as screws. On the other end side of the photosensitive drum 7, a metallic positioning pin 61 is press-fitted into the support hole 53 through the positioning portion 62 of the image carrier support frame 11d. As a result, the photosensitive drum 7 is rotatably supported with respect to the image carrier support frame 11d.

(Support and fixing structure of charging roller 8)
FIG. 1 is a perspective view of a support structure of a bearing member according to the present embodiment. FIG. 5 is a cross-sectional view of the support fixing configuration of the bearing member according to the present embodiment.

  As shown in FIGS. 1 and 5, the bearing member (support member) 80 a rotatably supports both ends of the rotation shaft 8 a of the charging roller 8. The charging roller 8 is urged in the direction of the photosensitive drum 7 by a compression spring (biasing means) 71 through a bearing member 80a. The compression spring 71 is integrally provided in the bearing member 80a by press-fitting or insert molding. The bearing member 80a has a flange 80b, and the image carrier support frame 11d has support fixing portions 11f at both ends in the longitudinal direction. By attaching the flange 80b to the support fixing portion 11f, the bearing member 80a is attached to the image carrier support frame 11d.

  The flange 80 b protrudes in a direction orthogonal to the urging direction for urging the charging roller 8 toward the photosensitive drum 7. The flange 80b is composed of a small-diameter columnar longitudinal restriction portion 80e and a large-diameter disc-shaped retaining restriction portion 80f. The retaining prevention portion 80f is provided to protrude from the longitudinal restriction portion 80e at the tip of the longitudinal restriction portion 80e.

  As shown in FIG. 1, the support fixing portion 11 f is a hole formed in a surface 11 e parallel to the urging direction for urging the charging roller 8 toward the photosensitive drum 7. The support fixing portion 11f has a keyhole shape in which the large diameter hole 11f2 is combined with one end of the small diameter long hole 11f1.

  As shown in FIG. 5, the bearing member 80a has a first position (the positions shown in FIGS. 5A and 5D) and a second position (the positions shown in FIGS. 5B and 5E). ) Is supported so as to be slidable (movable) in the urging direction of the compression spring 71 with the small diameter long hole 11f1 as a guide groove. At the first position, the charging roller 8 contacts the photosensitive drum 7 by the urging force of the compression spring 71. In the second position, the charging roller 8 is separated from the photosensitive drum 7 against the urging force of the compression spring 71.

  As shown in FIGS. 5D and 5E, the relationship between the size of the support fixing portion 11f and the flange 80b is as follows: the diameter of the longitudinal regulating portion 80e <the hole width of the small-diameter elongated hole 11f1 <the retaining regulating portion 80f. Is smaller than the diameter of the large-diameter hole 11f2. As a result, as shown in FIGS. 5 (a) and 5 (d), when the retainer restricting portion 80f is in the small diameter long hole 11f1, the retainer restricting portion 80f contacts the surface 11e, and the flange 80b is supported. The fixing portion 11f is prevented from coming off. On the other hand, as shown in FIGS. 5B and 5E, when the retaining prevention portion 80f is in the large-diameter hole 11f2, as shown in FIG. The flange 80b is removable from the support fixing portion 11f through the large-diameter hole 11f2 without coming into contact with 11e. The flange 80b is removed in a direction perpendicular to the longitudinal direction of the charging roller 8 and the urging direction of the compression spring 71 (the arrow X direction in FIG. 5C).

  In the above configuration, the bearing member 80a is moved up to the second position against the urging force of the compression spring 71 to move to the second position, and the bearing member 80a is removed from the large diameter hole 11f2 so as to remove the retaining member 80f. Remove from the support frame 11d. Thus, the charging roller 8 can be easily removed together with the bearing member 80a without removing the photosensitive drum 7 from the drum unit 11.

  When the charging roller 8 is assembled, the bearing member 80a that rotatably supports the charging roller 8 is slid (moved) from the position shown in FIG. 5C to the position shown in FIG. Is inserted into the large-diameter hole 11f2.

  At this time, one end of the compression spring 71 is provided integrally with the bearing member 80a, but the other end of the compression spring 71 is the receiving surface of the image carrier support frame 11d (perpendicular to the urging direction of the compression spring 71). Slide) 11i while being compressed. For this reason, the compression spring 71 may fall. Therefore, in order to abut against the compression spring 71 and prevent the compression spring 71 from falling, the bearing member 80a is in the vicinity of one end side of the compression spring 71, at least on the upstream side in the mounting direction of the bearing member 80a (arrow Y direction). A rib-shaped wall 80d was formed. The height of the wall 80d was set lower than the distance between the bearing member 80a in the second position and the receiving surface 11i. By providing a configuration that prevents the compression spring 71 from falling, the compression spring 71 can be reliably assembled.

  In forming an image, the charging roller 8 is rotated by the rotation of the photosensitive drum 7, and at this time, a voltage is applied to the charging roller 8 to uniformly charge the surface of the photosensitive drum 7. Therefore, at least one of the two bearing members 80a provided at both ends in the longitudinal direction of the charging roller 8 is formed of a conductive member such as a conductive polyacetal resin. As a result, a voltage is applied from the main body of the image forming apparatus to the rotary shaft 8a via the compression spring 71 having conductivity. The bearing member 80a on the other end side may also be made of a polyacetal resin that has good slidability with the metal rotating shaft 8a and is excellent in wear resistance.

  In this embodiment, the attachment / detachment of the charging roller 8 has been described as an example of the process means. However, the present invention can also be applied to attachment / detachment of other process means (the developing roller 10d, the cleaning blade 11a, etc.).

[Second Embodiment]
Next, a second embodiment of the support and fixing structure of the process means, the image forming apparatus, the process cartridge, and the developing apparatus according to the present invention will be described with reference to the drawings. About the part which overlaps with said 1st embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  FIG. 6 is a view showing a support and fixing configuration of the bearing member 80a according to the present embodiment. As shown in FIG. 6, the image forming apparatus A, the process cartridge B, and the developing unit (developing apparatus) 10 of the present embodiment are provided with a support fixing portion 11g instead of the support fixing portion 11f of the first embodiment. It is.

  The support fixing part 11g has a pair of guide parts 11g1, a pair of frame body length regulating parts 11g2, and a notch part 11g3. The pair of guide portions 11g1 and the frame body length regulating portion 11g2 guide the flange 80b to be slidable in the urging direction of the compression spring 71.

  The pair of frame body length regulating portions 11g2 are formed so as to protrude from the image carrier supporting frame body 11d, and sandwich the retaining prevention portion 80f in the longitudinal direction of the charging roller 8. The pair of guide portions 11g1 are formed so as to protrude in the longitudinal direction of the charging roller 8 from the tips of the pair of frame body length regulating portions 11g2, respectively, and sandwich the length regulating portion 80e in the longitudinal direction of the charging roller 8. As a result, the bearing member 80 a is restricted from moving in the longitudinal direction of the charging roller 8.

  The distance between the pair of guide portions 11g1 <the diameter of the retaining restriction portion 80f, and when the bearing member 80a is in the first position shown in FIG. 6A, the retaining restriction portion 80f contacts the guide portion 11g1. However, the movement of the bearing member 80a in the removal direction is restricted.

  The notch part 11g3 is a part of the pair of guide parts 11g1, and is sized to allow the retaining prevention part 80f to pass therethrough. Thereby, when the bearing member 80a is in the second position shown in FIG. 6B, the retaining restriction portion 80f comes out of the notch portion 11g3 without contacting the guide portion 11g1, and the flange 80b is supported by the support fixing portion 11g. It will be in the state which can be removed from. The flange 80b is removed in a direction orthogonal to the longitudinal direction of the charging roller 8 and the urging direction of the compression spring 71 (the direction of the arrow X in FIG. 6B).

  In the above configuration, the bearing member 80a is moved up to the second position against the urging force of the compression spring 71 to move to the second position, and the bearing member 80a is removed from the notch 11g3 to prevent the retaining member 80f from being removed. Remove from the support frame 11d. Thus, the charging roller 8 can be easily removed together with the bearing member 80a without removing the photosensitive drum 7 from the drum unit 11.

[Third embodiment]
Next, a third embodiment of the supporting and fixing structure of the process means, the image forming apparatus, the process cartridge, and the developing apparatus according to the present invention will be described with reference to the drawings. About the part which overlaps with said 1st embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  FIG. 7 is a view showing a support and fixing configuration of the bearing member 80a according to the present embodiment. As shown in FIG. 7, the image forming apparatus A, the process cartridge B, and the developing unit (developing apparatus) 10 according to the present embodiment include the support fixing portion 11g, the longitudinal restriction portion 80e, and the retaining prevention portion 80f according to the second embodiment. Instead, a support fixing portion 11h, a retaining prevention portion 80g, and a longitudinal restriction portion 80h are provided.

  In the second embodiment, the guide portion 11g1 and the frame body length regulating portion 11g2 on the image carrier supporting frame 11d side surround the retaining prevention portion 80f of the bearing member 80a. In the present embodiment, the longitudinal restriction portion 80h and the retaining prevention portion 80g on the bearing member 80a side surround the support fixing portion 11h (guide portion 11h1 and frame length restriction portion 11h2) on the image carrier support frame 11d side. And The guide portion 11h1 and the frame body length regulating portion 11h2 guide the flange 80b so as to be slidable in the urging direction of the compression spring 71.

  The frame length restriction portion 11h2 is provided so as to protrude from the image carrier support frame 11d, and a flange-shaped guide portion 11h1 is provided at the tip of the frame length restriction portion 11h2. The longitudinal restriction portion 80h sandwiches the guide portion 11h1, and the retaining prevention portion 80g sandwiches the frame body longitudinal restriction portion 11h2. As a result, the bearing member 80 a is restricted from moving in the longitudinal direction of the charging roller 8.

  The interval between the retaining prevention portions 80g is smaller than the diameter of the guide portion 11h1, and when the bearing member 80a is in the first position shown in FIG. 7A, the retaining prevention portion 80g contacts the guide portion 11h1, Movement of the bearing member 80a in the removal direction is restricted.

  The support fixing part 11h has a notch part 11h3. The cutout portion 11h3 is a cutout portion of the guide portion 11h1 (a predetermined position in the urging direction of the compression spring 71), so that the retaining prevention portion 80g does not interfere with the guide portion 11h1. . Thereby, when the bearing member 80a is in the second position shown in FIG. 7B, the retaining prevention portion 80g comes out of the notch portion 11h3 without contacting the guide portion 11h1, and the flange 80b is supported by the support fixing portion 11h. It will be in the state which can be removed from. The flange 80b is removed in a direction orthogonal to the longitudinal direction of the charging roller 8 and the urging direction of the compression spring 71 (the direction of the arrow X in FIG. 7B).

  In the above configuration, the bearing member 80a is moved up to the second position against the urging force of the compression spring 71 and moved to the second position, and the bearing member 80a is removed from the notch 11h3 so as to remove the retaining member 80g. Remove from the support frame 11d. Thus, the charging roller 8 can be easily removed together with the bearing member 80a without removing the photosensitive drum 7 from the drum unit 11.

A ... Image forming apparatus B ... Process cartridge 7 ... Photosensitive drum (image carrier)
8: Charging roller (charging means, process means)
8a ... rotating shaft 10 ... developing unit 11 ... drum unit 11d ... image carrier support frame 11e ... surface 11f, 11g ... support fixing part 11f1 ... small diameter long hole 11f2 ... large diameter holes 11g1, 11h1 ... guide parts 11g2, 11h2 ... frame Body length regulating portions 11g3, 11h3... Cutout portion 11i... Receiving surface 71... Compression spring (biasing means)
80a ... Bearing member (support member)
80b ... flange 80d ... walls 80e and 80h ... longitudinal restriction portions 80f and 80g ... retaining prevention portions

Claims (7)

A frame that rotatably supports an image carrier that carries a toner image;
Process means acting on the image carrier;
A support member for supporting the process means;
Biasing means for biasing the process means to the image carrier;
A support fixing portion provided on the frame body and slidably supporting the support member in parallel with the urging direction of the urging means;
The support member has a first position for bringing the process means into contact with the image carrier, and a second position for separating the process means from the image carrier against the biasing force of the biasing means. Is movable, and
The support fixing portion restricts the removal of the support member when the support member is in the first position, and the support member is separated from the support fixing portion when the support member is in the second position. A supporting and fixing structure for a process means, wherein the supporting member can be detached from the supporting and fixing portion by being removed.
The support member has a flange protruding in a direction orthogonal to the urging direction of the urging means,
The flange has a small-diameter columnar longitudinal restriction part, a large-diameter disk-like retaining restriction part,
The support fixing portion has a keyhole shape in which a large diameter hole is combined with one end of a small diameter long hole,
The longitudinal restricting portion is slidable in the small diameter long hole,
The diameter of the longitudinal regulating portion <the hole width of the small-diameter elongated hole <the diameter of the retaining regulating portion <the diameter of the large-diameter hole,
When the support member is in the first position, the retaining prevention restricting part does not come out of the small diameter long hole, thereby restricting the supporting member from coming off,
When the support member is in the second position, the retaining member restricts from the large-diameter hole, so that the support member comes out of the support fixing part and the support member is detached from the support fixing part. The support fixing structure for a process means according to claim 1, wherein the structure is supported.
One end of the urging means is provided integrally with the support member,
The said support member has a wall which prevents the fall of the said urging | biasing means in the upstream of the said urging | biasing means in the direction which incorporates the said support member in the said support fixing | fixed part. Fixed structure of process means.
4. The process means fixing structure according to claim 1, wherein the process means is a charging means for charging the image carrier.
5. A process cartridge comprising the process means fixing structure according to claim 1.
5. A developing device comprising the process means fixing structure according to claim 1.
An image carrier;
The developing device according to claim 6, wherein the electrostatic latent image formed on the image carrier is developed as a toner image using toner;
Transfer means for transferring the toner image formed by the developing device to a sheet;
An image forming apparatus comprising:

Images