Charging member, process cartridge, and image forming apparatus

1. A charging member comprising:

a support member;

a conductive elastic layer disposed on the support member; and

a front surface layer disposed on the conductive elastic layer,

wherein irregularities with a cycle of shorter than 0.1 mm and irregularities with a cycle of 0.1 mm or longer are distributed on an entirety of an outer circumferential surface of the charging member, and satisfy the following conditions of (1) and (2):

(1) the irregularities with the cycle of shorter than 0.1 mm have an average height of greater than 0 μm and 4 μm or less; and

(2) the irregularities with the cycle of 0.1 mm or longer have an average height of from 5 μm to 30 μm, and

wherein a half-value width of a maximum frequency value of height distribution on the outer circumferential surface is from 1 μm to 3 μm.

2. The charging member according to claim 1 ,

wherein the irregularities with the cycle of shorter than 0.1 mm have an average height of from 0.5 μm to 3.5 μm.

3. The charging member according to claim 1 ,

wherein the irregularities with the cycle of shorter than 0.1 mm have an average height of from 1.0 μm to 3.0 μm.

4. The charging member according to claim 1 ,

wherein the irregularities with the cycle of 0.1 mm or longer have an average height of from 5 μm to 20 μm.

5. The charging member according to claim 1 ,

wherein the irregularities with the cycle of 0.1 mm or longer have an average height of from 6 μm to 10 μm.

6. The charging member according to claim 1 ,

wherein a mean cycle of the irregularities with the cycle of shorter than 0.1 mm is 5 μm or longer.

7. The charging member according to claim 1 ,

wherein a mean cycle of the irregularities with the cycle of shorter than 0.1 mm is 50 μm or shorter.

8. The charging member according to claim 1 ,

wherein a mean cycle of the irregularities with the cycle of 0.1 mm or longer is 0.15 mm or longer.

9. The charging member according to claim 1 ,

wherein a mean cycle of the irregularities with the cycle of 0.1 mm or longer is 0.45 mm or shorter.

10. The charging member according to claim 1 ,

wherein the front surface layer contains an electronically conductive agent.

11. The charging member according to claim 10 ,

wherein the electronically conductive agent is a metal oxide.

12. A process cartridge that is attached to or is detached from an image forming apparatus, comprising:

an electrophotographic photoreceptor; and

a charging device that includes the charging member according to claim 1 , that applies, to the charging member, only a DC voltage or a voltage obtained by superimposing an AC voltage to a DC voltage, and that charges a front surface of the electrophotographic photoreceptor by a contact charging method.

13. An image forming apparatus comprising:

an electrophotographic photoreceptor;

a charging device that includes the charging member according to claim 1 , that applies, to the charging member, only a DC voltage or a voltage obtained by superimposing an AC voltage to a DC voltage, and that charges a front surface of the electrophotographic photoreceptor by a contact charging method;

a latent image forming device that forms a latent image on the front surface of the charged electrophotographic photoreceptor;

a developing device that develops the latent image formed on the front surface of the electrophotographic photoreceptor, using developer containing toner, and forms a toner image on the front surface of the electrophotographic photoreceptor; and

a transfer device that transfers the toner image formed on the front surface of the electrophotographic photoreceptor to a recording medium.