Position clutch device and image forming apparatus using the same

Abstract

An improved position clutch includes a motor, a worm gear shaft, a cam gear, a cam shaft, and a cam. The worm gear shaft is rotated by the motor and has a worm gear portion on a predetermined section of the end of the shaft. The cam gear has at least one teeth portion formed on its circumference, and the cam gear engages the worm gear portion. The cam shaft is connected to the cam gear; and the cam is connected to the cam shaft. The cam engages an object, such as a cleaning blade, to control the position of the object.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features, and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a side view of a portion of the structure of a conventional image forming apparatus;

FIG. 2 is an enlarged view of the area indicated by II in FIG. 1;

FIG. 3 is an enlarged view of the area indicated by III in FIG. 1;

FIG. 4 is a perspective view of an exemplary embodiment of a cam driving unit for driving the cam in FIGS. 2 and 3;

FIG. 5 is an exploded perspective view of the structure of the spring clutch in FIG. 4;

FIG. 6 is a schematic diagram of an image forming apparatus with a position clutch according to an exemplary embodiment of the present invention is applied;

FIG. 7 is an enlarged view of the area indicated by VII in FIG. 6;

FIG. 8 is an enlarged view of the area indicated by VIII in FIG. 6;

FIG. 9 is an enlarged view of the area indicated by IX in FIG. 6;

FIG. 10 is a perspective view of a transfer belt interrupter unit and a first and a second cleaning blade interrupter unit for use in the exemplary embodiments of the present invention;

FIG. 11 is a diagram of a state in which the second cleaning blade of the exemplary embodiment of the present invention is engaged with the transfer belt; and

FIG. 12 is a diagram of a state in which the second cleaning blade of the exemplary embodiment of the present invention is disengaged from the transfer belt.

Claims

1. A position clutch device, comprising: a motor;a worm gear shaft rotated by the motor, the worm gear shaft comprising a worm gear portion formed on a first end of the worm gear shaft;a cam gear comprising at least one teeth portion that engages the worm gear portion;a cam shaft connected to the cam gear; andat least one cam connected to the cam shaft, the at least one cam engaging an object to control the position of the object.

2. The device of claim 1, further comprising: an elastic unit for preventing the teeth portion of the cam gear from disengaging the worm gear portion.

3. The device of claim 2, wherein the elastic unit comprises a torsion spring, a first end of which is fixed onto the cam gear shaft, and a second end of which is combined with a fixing body.

4. The device of claim 1, wherein the motor is rotated in clockwise and counterclockwise directions.

5. The device of claim 1, further comprising: a follower gear formed on a second end of the worm gear shaft; anda driving gear disposed on a shaft of the motor, the driving gear engaging the follower gear.

6. An image forming apparatus, comprising: at least one photosensitive medium for forming an electrostatic latent image;at least one developer for developing the electrostatic latent image on the photosensitive medium with developer;a transfer unit for transferring the developed image onto a recording medium;a cleaning blade for removing waste developer remaining on the photosensitive medium; anda cleaning blade interrupt generation unit for engaging/disengaging the cleaning blade with/from the photosensitive medium, the cleaning blade interrupt generation unit comprising: a motor;a worm gear shaft rotated by the motor, the worm gear shaft comprising a worm gear portion formed on a first end of the worm gear shaft;a cam gear comprising at least one teeth portion that engages the worm gear portion;a cam shaft connected to the cam gear; andat least one cam connected to the cam shaft, the at least one cam controlling the position of the cleaning blade.

7. The apparatus of claim 6, further comprising: an elastic unit for preventing the teeth portion of the cam gear from disengaging the worm gear portion.

8. The apparatus of claim 7, wherein the elastic unit comprises a torsion spring, a first end of which is fixed onto the cam gear shaft, and a second end of which is combined with a fixing body.

9. The apparatus of claim 6, wherein the motor is rotated in clockwise and counterclockwise directions.

10. The apparatus of claim 6, further comprising: a follower gear formed on a second end of the worm gear shaft; anda driving gear disposed on a shaft of the motor, the driving gear engaging the follower gear.

11. An image forming apparatus, comprising: at least one photosensitive medium for forming electrostatic latent images;at least one developer for developing the electrostatic latent images formed on the photosensitive medium with a color developer;a transfer belt on which the developed images are transferred and superimposed upon each other;a transfer roller for transferring the superimposed color image formed on the transfer belt onto a recording medium; anda transfer roller interrupt generation unit for engaging/disengaging the transfer roller with/from the transfer belt, the transfer roller interrupt generation unit comprising: a motor;a worm gear shaft rotated by the motor, the worm gear shaft comprising a worm gear portion formed on a first end of the worm gear shaft;a cam gear comprising at least one teeth portion that engages the worm gear portion;a cam shaft connected to the cam gear; andat least one cam connected to the cam shaft, the at least one cam controlling the position of the transfer roller.

12. The apparatus of claim 9, further comprising: an elastic unit for preventing the teeth portion of the cam gear from disengaging the worm gear portion.

13. The apparatus of claim 12, wherein the elastic unit comprises a torsion spring, a first end of which is fixed onto the cam gear shaft, and a second end of which is combined with a fixing body.

14. The apparatus of claim 11, wherein the motor is rotated in clockwise and counterclockwise directions.

15. The apparatus of claim 11, further comprising: a follower gear formed on a second end of the worm gear shaft; anda driving gear disposed on a shaft of the motor, the driving gear engaging the follower gear.