Semiconductive belt, semiconductive roll and image forming apparatus using these members

Abstract

A semiconductive belt includes: at least one different resistance portion that is configured to partly differ in surface resistance from surroundings, wherein the at least one different resistance portion is at an angle with respect to a direction perpendicular to a belt end portion.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary Embodiment(s) of the present invention will be described in detail based on the following figures, wherein:

FIG. 1 is a diagram illustrating an image forming apparatus to which an exemplary embodiment of the invention is applied;

FIGS. 2A and 2B are diagrams respectively illustrating the structures of an intermediate transfer belt and a secondary transfer roll, which are exemplary examples of a semiconductive member;

FIGS. 3A and 3B are diagrams illustrating different resistance portions provided on surfaces of semiconductive belts;

FIGS. 4A and 4B are diagrams illustrating different resistance portions provided on surfaces of semiconductive rolls;

FIG. 5 is a diagram illustrating extrusion molding;

FIGS. 6A and 6B are views illustrating resistance mapping performed in a lateral direction of an endless belt;

FIGS. 7A and 7B are graphs illustrating results of monitoring a transferring voltage;

FIGS. 8A and 8B are cross-sectional diagrams illustrating a die;

FIGS. 9A and 9B are diagrams illustrating press molding performed using an ordinary two-piece press die; and

FIG. 10 is a diagram illustrating an extruder of the straight die type.

Claims

1. A semiconductive belt comprising: at least one different resistance portion that is configured to partly differ in surface resistance from surroundings,wherein the at least one different resistance portion is at an angle with respect to a direction perpendicular to a belt end portion.

2. The semiconductive belt according to claim 1, wherein the at least one different resistance portion has a width ranging from about 0.5 mm to about 50 mm; andthe angle ranges from about 30 degrees to about 60 degrees.

3. The semiconductive belt according to claim 1, wherein the number of the at least one different resistance portion ranges from 1 to 10.

4. The semiconductive belt according to claim 1, which comprises: one of a rubber material and a thermoplastic elastomer; and an electrically conductive filler.

5. The semiconductive belt according to claim 4, wherein the electrically conductive filler has ionic conductivity or electronic conductivity.

6. The semiconductive belt according to claim 1, which has a volume resistivity ranging from about 103 Ωcm to about 1012 Ωcm.

7. The semiconductive belt according to claim 1, which comprises: a belt member containing a rubber material; andat least one additional layer on the belt member.

8. A semiconductive roll comprising: at least one different resistance portion that is configured to partly differ in surface resistance from surroundings,wherein the at least one different resistance portion is at an angle with respect to a longitudinal direction.

9. The semiconductive roll according to claim 8, wherein the at least one different resistance portion has a width ranging from about 0.5 mm to about 30 mm; andthe angle is equal to or more than about 15 degrees.

10. The semiconductive roll according to claim 8, wherein an absolute value (Δlog Ω) of a difference between a common logarithm value (log ΩH) of a surface resistance value of the at least one different resistance portion and a common logarithm value (log ΩL) of a surface resistance value of the surroundings is at least about 0.2.

11. The semiconductive roll according to claim 8, which has a semiconductive elastic layer containing an ionic conductivity filler or an electronic conductivity filler, wherein the semiconductive elastic layer has a volume resistivity ranging from about 103 Ωcm to about 1012 Ωcm.

12. A semiconductive member manufacturing method of forming a semiconductive member by utilizing an extruder, the method comprising: performing extrusion-molding by rotating a mouthpiece or a core metal of the extruder so that at least one different resistance portion, which differ in surface resistance from surroundings, is at an angle with respect to an extruding direction, when a semiconductive material, which is put into the extruder and contains an elastic material and an electrically conductive filler, is extrusion-molded

13. A semiconductive member manufacturing method of forming a semiconductive member by utilizing a press molding apparatus, the method comprising: putting a semiconductive material, which contains an elastic material and an electrically conductive filler, into a press die having a die mating portion curved with respect to a heat plate surface of the press molding apparatus; andperforming press-molding under a pressure.

14. An image forming apparatus comprising: a toner image forming unit;a transfer unit adapted to transfer a toner image onto a recording material; anda fixing unit adapted to fix the toner image to the recording material,wherein the transfer unit has a semiconductive belt or a semiconductive roll, which comprises at least one different resistance portion that is configured to partly differ in surface resistance from surroundings and to be at an angle with respect to a direction perpendicular to a turning direction.

15. The image forming apparatus according to claim 14, wherein the semiconductive belt is an intermediate transfer belt that transfers a toner image formed by the toner image forming unit onto a surface of the intermediate transfer belt, and transfers the transferred toner image onto the recording material.

16. The image forming apparatus according to claim 14, wherein the semiconductive roll is a transfer roll that transfers a toner image formed by the toner image forming unit onto the recording material.