Roller with mechanical properties influenced by rotation

1. A roller capable for use as a developer roller in a printer comprising: a roller having a surface, a length and two end portions, wherein said roller provides a first surface flexibility (SF 1 ) when said roller rotates in one direction and a second surface flexibility (SF 2 ) when said roller rotates in a second direction wherein SF 1 and SF 2 have different values, and wherein said roller includes an inner portion, an outer portion and ribs extending from the inner portion to the outer portion wherein said inner portion, outer portion and ribs independently have a thickness in the range of about 0.5-5.0 mm, wherein said ribs are capable of bending when said roller rotates in one direction and compression when said roller rotates in a second direction and wherein said roller comprises polyepichlorohydrin or a polyurethane and said ribs extend from the two ends of said roller a distance of up to about 10 mm and said roller includes portions without said ribs along the length of said roller.

2. The roller of claim 1 wherein said first surface flexibility and second surface flexibility are provided at selected locations on said roller surface.

3. The roller of claim 1 wherein said roller has a radii and said ribs extend at an angle with respect to said radii.

4. The roller of claim 1 wherein said ribs include helical ribs.

5. The roller of claim 1 further comprising a shaft extending through said roller.

6. The roller of claim 1 wherein said roller defines cavities between said ribs.

7. The roller of claim 1 further comprising a coating on an outer surface of said roller.

8. The roller of claim 1 wherein said roller provides said first surface flexibility (SF 1 ) when said roller rotates in one direction and said second surface flexibility (SF 2 ) when said roller rotates in a second direction at first and second end portions of said roller.

9. The roller of claim 8 wherein said roller is solid between said first and second end portions.

10. A cartridge for use in an image forming apparatus, said cartridge comprising: a frame member; a roller having a length and two end portions and rotatably mounted on said frame member, said roller having a first surface flexibility (SF 1 ) when said roller rotates in one direction and a second surface flexibility (SF 2 ) when said roller rotates in a second direction wherein SF 1 and SF 2 have different values; and at least one sealing member mounted to said frame member, said sealing member contacting said roller, and wherein said roller includes an inner portion, an outer portion and ribs extending from the inner portion to the outer portion wherein said inner portion, outer portion and ribs independently have a thickness in the range of about 0.5-5.0 mm, wherein said ribs are capable of bending when said roller rotates in one direction and compression when said roller rotates in a second direction and wherein said roller comprises polyepichlorohydrin or a polyurethane and said ribs extend from the two ends of said roller a distance of up to about 10 mm and said roller includes portions without said ribs along the length of said roller.

11. The cartridge of claim 10 wherein said at least one sealing member includes first and second sealing members contacting a first and second portion of said roller.

12. The cartridge of claim 11 wherein said first and second portions of said roller include a first and second end portion of said roller.

13. The roller of claim 12 wherein said roller is solid between said first and second end portions.

14. The cartridge of claim 10 wherein said roller has a radii and said ribs extend at an angle with respect to said radii.

15. The cartridge of claim 10 wherein said ribs include helical ribs.

16. The cartridge of claim 10 further comprising a photoconductive drum rotatably mounted in said frame, wherein said photoconductive drum is in contact with said roller.

17. The cartridge of claim 16 wherein said roller applies a developer material to said photoconductive drum.

18. An image forming apparatus comprising: a frame member; a roller having a length and two end portions rotatably mounted on said frame member, said roller having a first surface flexibility (SF 1 ) when said roller rotates in one direction and a second surface flexibility (SF 2 ) when said roller rotates in a second direction wherein SF 1 and SF 2 have different values; and at least one sealing member mounted to said frame member, said sealing member contacting said roller, and wherein said roller includes an inner portion, an outer portion and ribs extending from the inner portion to the outer portion wherein said inner portion, outer portion and ribs independently have a thickness in the range of about 0.5-5.0 mm, wherein said ribs are capable of bending when said roller rotates in one direction and compression when said roller rotates in a second direction and wherein said roller comprises polyepichlorohydrin or a polyurethane and said ribs extend from said two ends of said roller a distance of up to about 10 mm and said roller includes portions without said ribs along the length of said roller.

19. The image forming device of claim 18 wherein said at least one sealing member includes first and second sealing members contacting a first and second portion of said roller.

20. The image forming device of claim 18 wherein said first and second portions of said roller comprise a first and second end portion of said roller.