IMAGE FORMING APPARATUS, PROCESS CARTRIDGE, AND LUBRICANT APPLICATOR

Abstract

An image forming apparatus includes a photoconductor and a lubricant applicator. The photoconductor carries a toner image formed by developing an electrostatic latent image with a toner. The lubricant applicator applies a solid lubricant to a surface of the photoconductor, and includes a brush roller, a holder, a pressing member, and a protrusion. The holder holds the solid lubricant. The brush roller scrapes off the solid lubricant from the holder and applies the scraped solid lubricant to the surface of the photoconductor. The pressing member has an ellipse shape and presses the solid lubricant toward the brush roller via the holder. The protrusion is disposed on the holder and contacts an inner circumferential surface of the pressing member at two positions provided in both end portions of the pressing member in a direction of a minor axis of the ellipse formed by the pressing member to support the pressing member.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the invention and the many attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:

FIG. 1 is a schematic view of an image forming apparatus according to an exemplary embodiment of the present invention;

FIG. 2 is a schematic view of a process cartridge included in the image forming apparatus shown in FIG. 1;

FIG. 3 is a front view of a lubricant applicator included in the process cartridge shown in FIG. 2;

FIG. 4A is a top view of a tester lubricant applicator;

FIG. 4B is a sectional side view of the tester lubricant applicator shown in FIG. 4A;

FIG. 4C is a top view of the tester lubricant applicator shown in FIG. 4A after a pressing member is set;

FIG. 4D is a sectional side view of the tester lubricant applicator shown in FIG. 4C;

FIG. 5A is a top view of the tester lubricant applicator shown in FIG. 4A after a pressing member having a small inner diameter is set;

FIG. 5B is a sectional side view of the tester lubricant applicator shown in FIG. 5A;

FIG. 6A is a top view of the lubricant applicator shown in FIG. 3;

FIG. 6B is a sectional side view of the lubricant applicator shown in FIG. 6A;

FIG. 6C is a top view of the lubricant applicator shown in FIG. 6A after a pressing member is set;

FIG. 6D is a sectional side view of the lubricant applicator shown in FIG. 6C;

FIG. 7A is a top view of a lubricant applicator according to another exemplary embodiment of the present invention;

FIG. 7B is a sectional side view of the lubricant applicator shown in FIG. 7A;

FIG. 7C is a top view of the lubricant applicator shown in FIG. 7A after a pressing member is set;

FIG. 7D is a sectional side view of the lubricant applicator shown in FIG. 7C;

FIG. 8A is a sectional side view of a protrusion included in the lubricant applicator shown in FIG. 6A or 7A and having an exemplary shape;

FIG. 8B is a sectional side view of a protrusion included in the lubricant applicator shown in FIG. 6A or 7A and having another exemplary shape;

FIG. 8C is a sectional side view of a protrusion included in the lubricant applicator shown in FIG. 6A or 7A and having yet another exemplary shape;

FIG. 9A is an illustration of a toner particle for explaining a shape factor SF-1;

FIG. 9B is an illustration of a toner particle for explaining a shape factor SF-2;

FIG. 10A is an illustration of a toner particle according to an exemplary embodiment of the present invention;

FIG. 10B is a front view of the toner particle shown in FIG. 10A; and

FIG. 10C is a side view of the toner particle shown in FIG. 10A.

Claims

1. An image forming apparatus, comprising: a photoconductor configured to carry a toner image formed by developing an electrostatic latent image with a toner; anda lubricant applicator configured to apply a solid lubricant to a surface of the photoconductor, the lubricant applicator including a holder configured to hold the solid lubricant,a brush roller configured to scrape off the solid lubricant from the holder and apply the scraped solid lubricant to the surface of the photoconductor,a pressing member having an ellipse shape and configured to press the solid lubricant toward the brush roller via the holder, anda protrusion disposed on the holder and configured to contact an inner circumferential surface of the pressing member at two positions provided in both end portions of the pressing member in a direction of a minor axis of the ellipse formed by the pressing member so as to support the pressing member.

2. The image forming apparatus according to claim 1, wherein the solid lubricant has a bar shape.

3. The image forming apparatus according to claim 1, wherein the pressing member includes a compression spring.

4. The image forming apparatus according to claim 1, wherein the protrusion has a cylindrical shape.

5. The image forming apparatus according to claim 1, wherein the protrusion has a cylindroid shape, anda length of a major axis of an ellipse formed by the protrusion is shorter than an inner diameter in a direction of a major axis of the ellipse formed by the pressing member.

6. The image forming apparatus according to claim 1, wherein the holder includes a metal sheet and is embossed to form the protrusion.

7. The image forming apparatus according to claim 1, wherein the holder includes a resin and is integrally molded with the protrusion.

8. The image forming apparatus according to claim 1, wherein the protrusion includes a tapered head portion.

9. The image forming apparatus according to claim 1, wherein the protrusion includes a head portion having a conical shape.

10. The image forming apparatus according to claim 1, wherein the protrusion includes a head portion having a hemispherical shape.

11. The image forming apparatus according to claim 1, wherein the solid lubricant includes zinc stearate.

12. The image forming apparatus according to claim 1, further comprising: a process cartridge, including the photoconductor and the lubricant applicator, configured to attach and detach from the image forming apparatus.

13. A process cartridge, comprising: a photoconductor configured to carry a toner image formed by developing an electrostatic latent image with a toner; anda lubricant applicator configured to apply a solid lubricant to a surface of the photoconductor, the lubricant applicator including a holder configured to hold the solid lubricant,a brush roller configured to scrape off the solid lubricant from the holder and apply the scraped solid lubricant to the surface of the photoconductor,a pressing member having an ellipse shape and configured to press the solid lubricant toward the brush roller via the holder, anda protrusion disposed on the holder and configured to contact an inner circumferential surface of the pressing member at two positions provided in both end portions of the pressing member in a direction of a minor axis of the ellipse formed by the pressing member so as to support the pressing member.

14. The process cartridge according to claim 13, wherein the toner has a volume average particle size Dv in a range of about 3 μm to about 8 μm and a particle size distribution ratio Dv/Dn of a volume average particular size Dv to a number average particle size Dn in a range of about 1.00 to about 1.40.

15. The process cartridge according to claim 13, wherein the toner includes toner particles having a shape factor SF-1 in a range of from about 100 to about 180 and a shape factor SF-2 in a range of from about 100 to about 180.

16. The process cartridge according to claim 13, wherein the toner includes toner particles having a sphere-like shape and satisfying the following: r1≧r2≧r3r1, r2, and r3 represent a long diameter, a short diameter, and a thickness of a toner particle, respectively, anda ratio r2/r1 of the short diameter r2 to the long diameter r1 ranges from about 0.5 to about 1.0 and a ratio r3/r2 of the thickness r3 to the short diameter r2 ranges from about 0.7 to about 1.0.

17. A lubricant applicator for applying a solid lubricant to a surface of a photoconductor, comprising: a holder configured to hold the solid lubricant;a brush roller configured to scrape off the solid lubricant from the holder and apply the scraped solid lubricant to the surface of the photoconductor;a pressing member having an ellipse shape and configured to press the solid lubricant toward the brush roller via the holder; anda protrusion disposed on the holder and configured to contact an inner circumferential surface of the pressing member at two positions provided in both end portions of the pressing member in a direction of a minor axis of the ellipse formed by the pressing member so as to support the pressing member.

18. The lubricant applicator according to claim 17, wherein the pressing member includes a compression spring.

19. The lubricant applicator according to claim 17, wherein the protrusion has a cylindrical shape.

20. The lubricant applicator according to claim 17, wherein the protrusion has a cylindroid shape, anda length of a major axis of an ellipse formed by the protrusion is shorter than an inner diameter in a direction of a major axis of the ellipse formed by the pressing member.