Fixing device and electro photographic apparatus using the same

1. A fixing device, comprising:

a heating roller that generates heat and has a mold releasing property;

a pressure belt that is brought into contact with the heating roller to form a nip therebetween and is driven according to a rotation of the heating roller;

a pressure roller around which the pressure belt is surrounded;

an arm that holds an end of the pressure roller and presses the pressure roller to press the pressure belt toward the heating roller; and

a belt regulating member that swingably intervenes between the pressure belt and the arm and contacts an end face of the pressure belt to regulate a shift thereof,

wherein the arm comprises a first surface which faces toward the belt regulating member, and the belt regulating member comprises a second surface which faces toward the arm, and

wherein a protrusion is formed on at least one of the first and second surfaces such that the belt regulating member is inclined with respect to the arm, to thereby push a contact point between the belt regulating member and the end face of the pressure belt away from the nip.

2. The fixing device according to claim 1 , wherein the belt regulating member includes:

a guide part that is formed in a partial cylindrical shape and guides an inner side of the pressure belt; and

a flange part that contacts the end face of the pressure belt.

3. The fixing device according to claim 2 , wherein the belt regulating member is configured to be swingable around the protrusion with respect to the arm.

4. The fixing device according to claim 2 , wherein the flange part is inclined with respect to the end face of the pressure belt, and

wherein the end face of the pressure belt contacts the flange part at a point where the pressure belt is bent to contact the guide part.

5. The fixing device according to claim 2 , wherein a range of an angle formed between the flange part and the end face of the pressure belt is equal to or smaller than 2 degrees.

6. The fixing device according to claim 1 , wherein the belt regulating member comprises a resin having a heat resistance property and a is slidable.

7. An electro-photographic apparatus comprising the fixing device according to claim 1 .

8. The fixing device according to claim 1 , further comprising:

a pressure stay that brings into contact the pressure belt with the heating roller,

wherein the arm comprises a groove that engages with the pressure stay.

9. The fixing device according to claim 8 , wherein the arm further comprises:

a bearing that maintains the rotation of the pressure roller; and

a spring that brings the pressure roller into contact with the heating roller.

10. The fixing device according to claim 1 , wherein the arm comprises:

a bearing that maintains the rotation of the pressure roller; and

a spring that brings the pressure roller into contact with the heating roller.

11. The fixing device according to claim 1 , wherein the end of the pressure roller is inserted in the arm into a lateral direction of an extension of the pressure belt.

12. The fixing device according to claim 1 , wherein the protrusion is disposed on the second surface of the belt regulating member to abut the arm.

13. The fixing device according to claim 12 , wherein the protrusion causes the belt regulating member to be swingable with respect to the arm.

14. The fixing device according to claim 12 , further comprising a plurality of ones of the protrusion.

15. A fixing device, comprising:

a heating roller, including:

a core metal;

a heat source that generates a heat and is disposed in the core metal;

a rubber layer that surrounds the core metal; and

a coating that has a mold releasing property and coats the rubber layer; and a pressure unit, including:

a pressure belt that is brought into contact with the heating roller to form a nip therebetween and is driven according to a rotation of the heating roller;

a pressure roller around which the pressure belt is surrounded;

an arm that holds an end of the pressure roller and presses the pressure roller to press the pressure belt toward the heating roller; and

a belt regulating member that is disposed between the pressure belt and the arm, and that contacts an end face of the pressure belt to regulate a shift thereof and is configured to be swingable with respect to the arm,

wherein the arm comprises a first surface which faces toward the belt regulating member, and the belt regulating member comprises a second surface which faces toward the arm, and

wherein a protrusion is formed on at least one of the first and second surfaces such that the belt regulating member is inclined with respect to the arm, to thereby push a contact point between the belt regulating member and the end face of the pressure belt away from the nip.

16. The fixing device according to claim 15 , wherein the pressure roller engages with a bearing located in the arm.

17. The fixing device according to claim 15 , wherein the arm comprises:

a bearing that maintains the rotation of the pressure roller; and

a spring that brings the pressure roller into contact with the heating roller.

18. The fixing device according to claim 17 , further comprising:

a pressure stay that brings into contact the pressure belt with the heating roller,

wherein the arm further comprises a groove that engages with the pressure stay.

19. The fixing device according to claim 15 , wherein the arm abuts the belt regulating member in a lateral direction of an extension of the pressure belt.

20. The fixing device according to claim 15 , wherein the end of the pressure roller is inserted into the arm in a lateral direction of an extension of the pressure belt.