Charging member, process cartridge and image forming apparatus

• US 5,384,626 A
• Filed: 09/07/1993
• Issued: 01/24/1995
• Est. Priority Date: 09/07/1992
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Yano, Hideyuki, Furuya, Tadashi, Araya, Junji, Kugoh, Harumi
• Primary Examiner(s): Pendegrass, Joan H.
• Application Number:
  US08/116,704
• Time in Patent Office: 504 Days
• Field of Search: 355/219, 355/200, 355/210, 355/231, 361/225, 361/229
• US Class Current: 399/176
• CPC Class Codes: G03G 15/0233 Structure, details of the charging member, e.g. chemical composition, surface properties
• CPC Class Codes: G03G 2221/183 Process cartridge

Abstract

A charging member for charging a member to be charged while being in contact therewith includes conductive base for being supplied with a voltage; a surface layer contactable to the member to be charged; a sponge layer between the conductive base and the surface layer; a 100% modulus M₁₀₀ (kg/cm²) of the surface layer and a thickness d (cm) of the surface layer satisfied:

M.sub.100 ×d≦1.5 (kg/cm).

Claims

1. A charging member for charging a member to be charged while being in contact therewith, comprising:

a conductive base for being supplied with a voltage;

a surface layer contactable to the member to be charged;

a sponge layer between said conductive base and said surface layer;

a 100% modulus M₁₀₀ (kg/cm²) of said surface layer and a thickness d (cm) of the surface layer satisfied;

space="preserve" listing-type="equation">M.sub.100 ×

d≦

1.5(kg/cm).

2. A process cartridge detachably mountable to an image forming apparatus, comprising:

an image bearing member;

a charging member contactable to said image bearing member to electrically charge said image bearing member, said charging member including a conductive base for being supplied with a voltage, a surface layer contactable to said image bearing member and a sponge layer between said conductive base and said surface layer;

wherein a 100% modulus M₁₀₀ (kg/cm²) of said surface layer and a thickness d (cm) of the surface layer satisfy;

space="preserve" listing-type="equation">M.sub.100 ×

d≦

1.5(kg/cm).

3. A process cartridge according to claim 2, wherein said process cartridge contains developing means for developing said image bearing member with toner.

4. An image forming apparatus comprising:

an image bearing member;

a charging member contactable to said image bearing member to electrically charge said image bearing member, said charging member including a conductive base for being supplied with a voltage, a surface layer contactable to said image bearing member and a sponge layer between said conductive base and said surface layer;

wherein a 100% modulus M₁₀₀ (kg/cm²) of said surface layer and a thickness d (cm) of the surface layer satisfy;

space="preserve" listing-type="equation">M.sub.100 ×

d≦

1.5(kg/cm).

5. An apparatus according to claim 4, wherein said voltage is an oscillating voltage.

6. An apparatus according to claim 5, wherein said oscillating voltage is an AC voltage biased with a DC voltage.

7. An apparatus according to claim 4, wherein said surface layer has a volume resistivity larger than that of said sponge layer.

8. An apparatus according to claim 4, wherein said surface layer comprises as a major component non-rubber resin material.

9. An apparatus according to claim 4, wherein the thickness of said surface layer is not less than 50 microns.