JP4330408B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus such as a printer, a copying machine, and a facsimile, and more particularly to an image carrier that prevents toner scattered from a unit including an image carrier and an image carrier from entering a writing unit.

  Some image forming apparatuses such as printers, particularly full-color printers, have a photosensitive unit or developing unit as an image carrier disposed above a writing unit using a laser. The toner scattered from the body unit or the like may enter the writing unit and accumulate in the laser emission portion. Then, the laser for writing on the photosensitive member is blocked by the toner, and the portion becomes a white streak image.

  An object of the present invention is to eliminate generation of a white streak image due to scattered toner by making it difficult for the scattered toner to enter the writing unit.

An image forming apparatus according to claim 1 of the present invention is a full-color printing apparatus having a plurality of image carriers arranged side by side and a writing unit disposed below the image carriers.
Arranged respectively partition member between said image bearing member and said writing unit, the partition member is made by bending repeatedly plate member at right angles, pass writing light vertical surface of the plate-like member and the opening surface having a plurality of windows, has a horizontal lower portion to follow the rotor surface, have been opened each window opening surface in correspondence to said plurality of image bearing members Rutotomoni,
The windows of these partition members are slit-like openings provided so that the longitudinal direction thereof is along the scanning direction of the writing unit, respectively.
A shutter mechanism having a plurality of shutter members for opening and closing the plurality of windows ;
The shutter member has an L-shaped cross section with a surface that opens and closes the window positioned parallel to the opening surface of the window and a surface that moves on the lower step portion of the partition member. None,
A surface of the shutter member positioned on the lower step portion is provided with a pair of parallel groove openings obliquely with respect to the opening surface of the window, and a member for engaging the shutter opening with the groove opening is provided.
The shutter member is moved toward and away from the window by moving the surface on the lower step portion obliquely on the lower step portion while the surface for opening and closing the window is parallel to the opening surface of the window. characterized Rukoto such as may be operated.

Those according to the second aspect is the image forming apparatus according to claim 1, wherein the shutter mechanism, to have the opening and closing drive means for interlocking the operations of the pre-carboxymethyl Yatta member to the operation member and the device other than the shutter member It is characterized by.

Which according to the claim 3 is the image forming apparatus according to claim 1 or 2, wherein the slit-shaped window, characterized in that the lower edge of its is, until it comes into contact with the lower portion of the partition member is not opened And

Those according to the fourth aspect, in any one of the image forming apparatus of claims 1 to 3, the lower surface of the surface to be positioned on the lower portion of the shutter member, the convex portion in contact with the lower upper surface of the partition member and wherein the Rukoto to have a.

According to a fifth aspect of the present invention , in the image forming apparatus according to any one of the first to fourth aspects, an elastic body is provided on a surface of the shutter member that is positioned in parallel with the opening surface of the window .

Those according to the claim 6 is the image forming apparatus according to claim 5, the elastic body of the shutter member, characterized in that it is a resin two-color molded product.

According to a seventh aspect of the present invention, in the image forming apparatus according to any one of the second to sixth aspects, the shutter member is provided with a cam surface, and the opening / closing drive means includes a member on the apparatus main body side that is in sliding contact with the cam surface. characterized Rukoto that Yusuke as the mating member of the cam surface.

Those according to the claim 8, in images forming apparatus according to claim 7, wherein said apparatus main body side member comprising a mating member before hear beam surface, side plates der Rukoto located in the vicinity of the partition member It is characterized by.

Those according to the ninth aspect is the image forming apparatus according to claim 8, between the partition member and the front Symbol shutter member, that Do by arranging a biasing means for moving urging the shutter member to the window side It is characterized by that.

Those according to the claim 10, in any one of the image forming apparatus of claims 2 to 9, and wherein the link mechanism der Rukoto said opening and closing means is provided in the member of the partition member or the device body To do.

According to an eleventh aspect of the present invention, in the image forming apparatus according to the ninth aspect , the shutter member is attached to and supported by a link forming the link mechanism .

Those according to the claim 12, in any one of the image forming apparatus of claims 2 to 9, wherein the opening and closing means, characterized that you conjunction with the cover opening and closing operation of the apparatus main body.

Those according to the claim 13 is the image forming apparatus according to claim 12, wherein the cover, characterized in cover der Rukoto located outermost of the apparatus main body.

According to the fourteenth aspect of the present invention, in the image forming apparatus according to any one of the first to thirteenth aspects, the image carrier is removed from the apparatus main body in conjunction with the attachment / detachment of the image carrier to the apparatus main body. the locking operation of the shutter member comprises a locking means to remain closed the window and said Rukoto to.

According to the fifteenth aspect of the present invention, in the image forming apparatus according to any one of the first to fourteenth aspects, the partition member has a high portion between the plurality of image carriers, is connected to the portion between the image carriers, and the No droop surface which descends relative site to the write portion of the image bearing member, and wherein the opening surface entirety in Rukoto the said vertical lower surface providing the window.

Those according to the claim 16, in any one of the image forming apparatus of claims 1 to 15, the pre Kizo carrier, characterized in that it comprises a process cartridge one unitized in combination with other components.

  In the image forming apparatus according to the present invention, the toner scattered from the photosensitive unit or the like is difficult to enter the writing unit, and the generation of the white streak image due to the accumulated toner remaining in the writing unit can be eliminated.

  The best mode for carrying out the present invention will be described below with reference to the embodiments shown in the drawings.

  FIG. 1 is a conceptual sectional view showing a full-color printer as an embodiment of an image forming apparatus according to the present invention, and FIG. 2 is a conceptual sectional view of an image forming unit. In the figure, reference numeral 1 denotes an image forming unit, which includes four color photoconductor units 2..., A transfer unit 3 and a writing unit 4, and each photoconductor unit 2 includes image forming means such as a photoconductor 5. . The image forming unit 1 includes a developing unit 6 for each photoconductor unit 2. In the figure, reference numeral 7 denotes an intermediate transfer belt.

  In the figure, reference numeral 8 denotes a paper feed unit including a paper feed cassette 9 and the like. Reference numeral 10 denotes a fixing / discharge unit, 11 denotes a fixing device, and 12 denotes a discharge port. In this apparatus, the color image is transferred by the image forming unit 1 to the paper fed from the paper feed cassette 9 of the paper feed unit 8, the image is fixed through the fixing device 11, and discharged from the paper discharge port 12. It has become. The color image formation and other configurations and operations are the same as those of a known apparatus, and a description thereof will be omitted.

  In the image forming unit 1, the writing unit 4 is positioned below the photosensitive unit 2, and a partition member 15 is disposed between the writing unit 4 and the photosensitive unit 2. In the figure, L indicates the optical path of the laser beam from the writing unit 4. However, for simplicity of explanation, it is simply referred to as laser light L.

  FIG. 3 is a perspective view (A) and a sectional view (B) showing the structure of the partition member 15. The partition member 15 is formed by repeatedly bending a plate-like member at a right angle so that the cross-section has an uneven shape. The partition member 15 has a higher portion between the plurality of photoreceptor units 2, specifically, a lower portion of the developing unit 6. Thus, the upper step portion 16 is connected to the upper step portion 16 and the portion facing the writing portion to the photosensitive member 5 is a descending lower surface 17, and a slit 18 is provided in the lower surface 17. . A laser beam L for forming a latent image on the photosensitive member 5 is emitted from the slit 18 by the polygon mirror 13 or the like. Further, a lower step portion 19 continues from the drooping surface 17 to the lower side of the photoreceptor unit 2, and the next drooping surface 17 (which is not provided with a slit because it does not correspond to a writing portion to the photoconductor 5), the next upper step. It continues to the part 16.

  The part where the slit 18 is provided is the hanging surface 17 along the vertical direction of the apparatus. When the image is written by the writing unit 4 from below the photosensitive member 5, the toner from the developing unit 6, the photosensitive member 5, etc. This is because the projected area of the slit 18 in the toner dropping direction is minimized because it is expected to fall.

The slit 18 is not provided to the boundary between the hanging surface 18 and the lower step portion 19, and the lower end of the slit 18 is positioned slightly above the upper surface of the lower step portion 19 by leaving the rising portion 17 a of the hanging surface 17. It is as. This is for preventing the toner X scattered on the lower step portion 19 from being accumulated from the slit 18 to the inside of the upper step portion 16, that is, the writing unit 4 side as shown in the figure. As will be described later , a shutter mechanism that operates by moving the upper surface of the lower step portion 19 is provided, and an opening / closing driving means is configured in conjunction with a front cover and an inner cover (face plate) of the apparatus main body (not shown) to form a shutter member 20. Therefore, when the shutter member moves so as to block the slit 18, the accumulated toner X is less likely to enter the slit 18. Is blocking.

  FIG. 4 is a perspective view (A) and a plan view (B) showing details of the shutter mechanism of the slit 18. The shutter mechanism of this embodiment includes a shutter member 20 having an L-shaped cross section, an urging member 21 such as a spring that urges the shutter member 20 so as to approach the slit 18, and a lower part of the partition member 15. 19 comprises step screws 22 and 22 for mounting on the top.

  The shutter member 20 has a pair of groove openings 23, 23 provided obliquely on a lower surface portion 20 a that is parallel to the lower step portion 19, and each groove opening 23 is indicated by an arrow in FIG. Thus, it moves in the direction which contacts / separates with respect to the slit 18 diagonally. The shutter member 20 is always pulled by the urging member 21 toward the front side of the figure. For this reason, the shutter member 20 closes the slit 18 in the default position. When the shutter member 20 is pushed from the front side in the figure to the rear side in the figure by a cover or a face plate (not shown) of the apparatus main body, along the groove opening 23. The shutter member 20 moves to open the slit 18 which is a laser emission port.

  FIG. 5 is a cross-sectional view showing the structure of the lower surface of the shutter member 20. As shown in the drawing, a plurality of convex portions 24 are provided on the lower surface, which is an operation moving surface, and even if the toner X falls on the lower step portion 19 of the partition member 15, the contact is minimized, and the toner X stays in the slit 18. It is designed to make it difficult to enter. In addition, although it is necessary to provide the convex part 24 at least three places in order to determine the plane of the lower surface of the shutter member 20, if the shutter member 20 is formed by sheet metal processing, it can be easily processed by half punching. Further, since the contact area between the shutter member 20 and the lower step portion 19 of the partition member 15 is reduced, the sliding resistance when the shutter member 20 is moved is reduced.

FIG. 5 is a cross-sectional view showing the structure of the lower surface of the shutter member 20. As shown in the drawing, a plurality of convex portions 24 are provided on the lower surface of the shutter member 20, and even if the toner X falls on the lower step portion 19 of the partition member 15, the contact is minimized and the toner X enters the slit 18. It is hard to get in. In addition, although it is necessary to provide the convex part 24 at least three places in order to determine the plane of the lower surface of the shutter member 20, if the shutter member 20 is formed by sheet metal processing, it can be easily processed by half punching. Further, since the contact area between the shutter member 20 and the lower step portion 19 of the partition member 15 is reduced, the sliding resistance when the shutter member 20 is moved is reduced.

  FIG. 7 is a plan view showing the main part of the third embodiment of the image forming apparatus according to the present invention, that is, the periphery of the shutter mechanism. The shutter member 20 of this embodiment is intended to reduce costs without using a moving step screw as in the previous embodiment. That is, the cam surface 26 is provided before and after the shutter member 20 (front and rear in the depth direction of the apparatus main body), and the side plates 27 and 28 positioned before and after the partition member 15 are in sliding contact with the cam surface 26. Opening and closing drive means is configured. Also in this embodiment, the urging member 21 such as a spring is disposed obliquely so that the cam surface 26 is always in contact with the side plates 27 and 28, and the shutter member is pressed by pushing it upward in the figure with the front cover or the like. 20 moves to open the slit 18. In the illustrated example, the upper cam surface 26 in the figure is a simple slope provided at the end of the shutter member 20, but the lower cam surface 26 is cut into the shutter member 20 to form a slope. However, depending on the relative positions of the side plates 27 and 28 and the shutter member 20, this may be reversed, or the cam mechanism can be configured using only one side plate. Other configurations are the same as in the previous embodiment.

  FIG. 8 is a perspective view showing the main part of the fourth embodiment of the image forming apparatus according to the present invention, that is, the periphery of the shutter mechanism. In this embodiment, the shutter member 30 is plate-shaped and both ends thereof are attached to the link mechanisms 31 and 31 to constitute a parallel movement mechanism. Although not shown, the spring 18 or the like is normally rotated downward to close the slit 18 and is pushed by the front cover or the like to raise the shutter member 30 to the state shown in the figure and open the slit 18. It is like that. This is effective when there are parts or the like around the lower step portion 19 of the partition member 15 and its surroundings, and the shutter member cannot be arranged as in the previous embodiment.

  The operation of the shutter member in the embodiment described above is all performed in conjunction with the operation of the cover, the face plate, etc., but this may be configured by protruding protrusions such as ribs from the cover, the face plate, etc. In addition, the end of the shutter member may be extended toward the cover or the like. Since this mechanism only needs to be pushed from the front of the apparatus main body, detailed illustration and description are omitted.

  FIG. 9 is a cross-sectional view showing the main part of the fifth embodiment of the image forming apparatus according to the present invention, that is, the lock mechanism of the shutter mechanism, which can be used in combination with any of the above-described embodiments. It is preferable that the shutter mechanism of the present invention is closed when the photosensitive unit 2 is replaced and is not opened even by a user's erroneous operation. Therefore, in this embodiment, when the photoconductor unit 2 is not provided, the lock mechanism 40 provided on the back side of the apparatus main body works to prevent the shutter members 20 and 30 from moving, and when the photoconductor unit 2 is inserted into the apparatus main body. The lock mechanism 40 is released so that the shutter members 20 and 30 can move.

  If the lifetime of the image forming unit, that is, the image forming unit 1 is different, such as the photosensitive unit 2, the developing unit 6, and the cleaning unit, they can be replaced separately to set an optimal replacement cycle. . However, there is a part that sacrifices maintainability and operability. Therefore, in order to improve maintainability, an image forming apparatus having a configuration in which the above-described shutter mechanism and a process cartridge are combined can be provided.

1 is a conceptual cross-sectional view showing a full-color printer as an embodiment of an image forming apparatus according to the present invention. Conceptual sectional view of image forming unit Perspective view (A) and sectional view (B) showing the structure of the partition member A perspective view (A) and a plan view (B) showing details of the shutter mechanism of the slit Sectional drawing which shows the structure of the lower surface of a shutter member Sectional drawing which shows the principal part of 2nd Example of the image forming apparatus which concerns on this invention. The top view which shows the principal part of 3rd Example of the image forming apparatus which concerns on this invention. The perspective view which shows the principal part of 4th Example of the image forming apparatus which concerns on this invention. Sectional drawing which shows the principal part of 5th Example of the image forming apparatus which concerns on this invention, ie, the locking mechanism of a shutter mechanism.

Explanation of symbols

1: Image forming unit 2: Photoconductor unit 3: Transfer unit 4: Writing unit 5: Photoconductor 6: Development unit 7: Intermediate transfer belt 8: Paper feed unit 9: Paper feed cassette 10: Fixing / paper discharge unit 11 : Fixing device 12: Paper discharge port 13: Polygon mirror 15: Partition member 16: Upper step portion 17: Hanging lower surface 17 a: Raised portion 18 of the lower surface 18: Slit 19: Lower step portion 20: Shutter member 21: Energizing member 22: Step Screw 23: Groove opening 24: Convex portion 25: Elastic member 26: Cam surface 27, 28: Side plate 30: Shutter member 31: Link mechanism L: Laser beam X: Toner

Claims (16)

In a full-color printing apparatus having a plurality of image carriers arranged side by side and a writing unit arranged below these image carriers,
Arranged respectively partition member between said image bearing member and said writing unit, the partition member is made by bending repeatedly plate member at right angles, pass writing light vertical surface of the plate-like member and the opening surface having a plurality of windows, has a horizontal lower portion to follow the rotor surface, have been opened each window opening surface in correspondence to said plurality of image bearing members Rutotomoni,
The windows of these partition members are slit-like openings provided so that the longitudinal direction thereof is along the scanning direction of the writing unit, respectively.
A shutter mechanism having a plurality of shutter members for opening and closing the plurality of windows ;
The shutter member has an L-shaped cross section with a surface that opens and closes the window positioned parallel to the opening surface of the window and a surface that moves on the lower step portion of the partition member. None,
A surface of the shutter member positioned on the lower step portion is provided with a pair of parallel groove openings obliquely with respect to the opening surface of the window, and a member for engaging the shutter opening with the groove opening is provided.
The shutter member is moved toward and away from the window by moving the surface on the lower step portion obliquely on the lower step portion while the surface for opening and closing the window is parallel to the opening surface of the window. an image forming apparatus comprising Rukoto such as may be operated. The image forming apparatus according to claim 1, wherein the shutter mechanism, before the image forming apparatus characterized by having a closing drive means for interlocking the operation to operation of the members or devices other than the shutter member of carboxymethyl Yatta member. The image forming apparatus according to claim 1 or 2, wherein the slit-shaped window, the lower edge of its is, the image forming apparatus characterized by not open until it comes into contact with the lower portion of the partition member. The image forming apparatus of claims 1 to 3, the lower surface of the surface to be positioned on the lower portion of the shutter member, and wherein the Rukoto to have a convex portion in contact with the lower upper surface of the partition member Image forming apparatus. The image forming apparatus of claims 1 to 4, the image forming apparatus characterized by comprising an elastic body on the surface to be positioned parallel to the opening surface of the window of the shutter member. The image forming apparatus according to claim 5, the elastic body of the shutter member, an image forming apparatus which is a resin two-color molded product. 7. The image forming apparatus according to claim 2 , wherein a cam surface is provided on the shutter member, and the opening / closing drive means has a member on the apparatus main body side in sliding contact with the cam surface as a counterpart member of the cam surface. An image forming apparatus. In images forming apparatus according to claim 7, wherein the apparatus main body side member comprising a mating member before hear beam plane, the image forming apparatus, wherein side plates der Rukoto located in the vicinity of the partition member. The image forming apparatus according to claim 8, between the partition member and the front Symbol shutter member, an image forming apparatus according to claim Rukoto such by arranging a biasing means for moving urging the shutter member to the window side. The image forming apparatus of claims 2 to 9, the image forming apparatus, wherein the link mechanism der Rukoto said opening and closing means is provided in the member of the partition member or the apparatus body. The image forming apparatus according to claim 9 , wherein the shutter member is attached to and supported by a link forming the link mechanism . The image forming apparatus of claims 2 to 9, wherein the opening and closing means, the image forming apparatus characterized that you conjunction with the cover opening and closing operation of the apparatus main body. The image forming apparatus according to claim 12, wherein the cover, the image forming apparatus, wherein the cover der Rukoto located outermost of the apparatus main body. The image forming apparatus of claims 1 to 13, in conjunction with the attachment and detachment of the said device body of the image bearing member, to lock the operation of the shutter member when the image bearing member were removed from the apparatus main body an image forming apparatus comprising Rukoto with a locking means to remain closed the window Te. 15. The image forming apparatus according to claim 1, wherein the partition member has a high portion between the plurality of image carriers, is connected to a portion between the image carriers, and is relative to a writing portion of the image carrier. No droop surface sites is lowered, an image forming apparatus, wherein the open surfaces entirety in Rukoto the said vertical lower surface providing the window. The image forming apparatus of claims 1 to 15, the pre Kizo carrier, an image forming apparatus which comprises a process cartridge one unitized in combination with other components.