Image forming device

Abstract

An image forming unit 100 has a main body 1 and an opening unit 22 that can be opened and closed with respect to the main body 1. An installation unit 99 is provided to install the secondary transfer roller 20 in the opening unit 22 so that a secondary transfer roller 20 of the opening unit 22 can move within a predetermined space within a bearing holder 25. When the opening unit 22 is closed, the secondary transfer roller 20 presses against an opposing roller 21 of the main body 1. A groove 32 in the main body 1 is formed in a direction different from a trajectory on which the shaft 20a of the secondary transfer roller 20 moves when closing the opening unit 22. The shaft 20a of the secondary transfer roller 20 is inserted into the groove 32 while moving within the predetermined space.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the attached drawings which form a part of this original disclosure:

FIG. 1 is a front cross-sectional view of a photocopier according to a preferred embodiment of the present invention;

FIG. 2 is an enlarged view of a main body part and opening unit of the photocopier according to the embodiment of the present invention;

FIG. 3 is an isometric view of the opening unit according to the embodiment of the present invention;

FIG. 4 is a front view of an opening unit part in which the transfer roller is installed in the opening unit according to the embodiment of the present invention;

FIG. 5 is an isometric view of a bearing member of the opening unit part according to the embodiment of the present invention;

FIG. 6 is an isometric view of a bearing holder of the opening unit part according to the embodiment of the present invention;

FIG. 7 is an isometric view of the part in which the transfer roller is installed in the opening unit according to the embodiment of the present invention;

FIG. 8 is a front view of the bearing holder and opening unit part provided to explain a method of installing the bearing holder in the opening unit according to the embodiment of the present invention;

FIG. 9 is an enlarged view of the main body part and opening unit showing the opening unit in the open state in the image forming device according to the embodiment of the present invention;

FIG. 10 is a cross-sectional diagrammatical view showing the positional relationship of the bearing member and the bearing holder when the opening unit of the image forming device is in the open state according to the embodiment of the present invention;

FIG. 11A through FIG. 11C are diagrammatical views showing the movement of a shaft of a secondary transfer roller of the opening unit when closing the opening unit in the image forming device according to the embodiment of the present invention;

FIG. 12A through FIG. 12C is a diagrammatical views showing the movement of the shaft of the secondary transfer roller when opening the opening unit in the image forming device according to the embodiment of the present invention; and

FIG. 13 is a diagrammatical view showing an opening unit in a conventional image forming unit.

Claims

1. An image forming device, comprising: an image forming unit being configured to form images based on image information;a main body being arranged to house said image forming unit, said main body having a transport path to transport sheets to form images by said image forming unit, said main body having a bearing guide disposed on said main body, said bearing guide having a groove;an opening unit being configured to open and close relative to said main body, said opening unit being configured to expose said transport path when in an open position and to conceal said transport path when in a closed position;a first roller having a shaft and being installed on said opening unit;an installation unit being configured to install said first roller in said opening unit, said installation unit being configured to facilitate insertion of said shaft into said groove and movement of said first roller within a predetermined space within said installation unit; anda second roller being provided in said main body, said second roller being configured to press against said first roller in said closed position of said opening unit,said groove being arranged to extend in a direction different from a direction of the trajectory on which said shaft of said first roller moves when moving said opening unit prior to making and after breaking contact with said main body, and when closing said opening unit said shaft of said first roller being inserted into said groove while moving within said predetermined space.

2. The image forming device according to claim 1, wherein when said shaft of said first roller moves within said predetermined space, said shaft of said first roller moves while contacting a frame surface of said main body that connects to said groove.

3. The image forming device according to claim 1, wherein said installation unit has an elastic member that presses said first roller against said second roller, and said shaft of said first roller moves within said predetermined space while all or a part of the force taken when said opening unit is being closed is absorbed by said elastic member.

4. The image forming device according to claim 3, wherein said installation unit has a bearing member into which said shaft of said first roller is installed and a bearing holder that holds said bearing member and that is fixed to a frame surface of said opening unit to cover said bearing member, said elastic member is provided between said bearing member and said surface of said opening unit, and said predetermined space is provided between said bearing member and said elastic member.

5. The image forming device according to claim 1, further comprising an intermediate transfer belt, wherein said first roller is a secondary transfer roller, said second roller is an opposing roller in opposition to said secondary transfer roller, said intermediate transfer belt is provided between said secondary transfer roller and said opposing roller and wound around said opposing roller, and said opposing roller is pressed by said secondary transfer roller via said intermediate transfer belt.

6. The image forming device according to claim 1, wherein said first roller is a transfer roller, said second roller is a photosensitive drum, and said photosensitive drum is pressed by said transfer roller.

7. The image forming device according to claim 4, wherein said groove is provided between a pair of wall surfaces disposed to encompass said trajectory of said shaft of said first roller in said groove, said bearing holder has a sloping surface formed on an end on said main body side, and when opening said opening unit from said closed position, said first roller is pushed from said groove by at least one of said wall surfaces forming said groove and said sloping surface formed in said end on said main body side of said bearing holder.

8. The image forming device according to claim 4, wherein when closing said opening unit from said open position, said first roller is inserted into said groove by sliding contact between said frame of said main body and said bearing holder and said shaft of said first roller.

9. The image forming device according to claim 7, wherein when closing said opening unit from said open position, said first roller is inserted into said groove by sliding contact between said frame of said main body and said bearing holder and said shaft of said first roller.

10. The image forming device according to claim 9, wherein said bearing holder has a holding frame formed to cover said shaft of said first roller, and two joining portions disposed at both ends of said holding frame in a direction extending from a surface of said opening unit.