Cleaning member for image forming apparatus, charging device, unit for image forming apparatus, process cartridge, and image forming apparatus

1. A cleaning member for an image forming apparatus, comprising:

a core; and

an elastic layer that is formed by a strip-shaped elastic member helically wound around an outer peripheral surface of the core,

wherein the cleaning member satisfies the following formula (1):

0.85 <t/T< 1.0  (1)

where t (mm) denotes a thickness of the elastic layer, the thickness being taken in a central portion in a helical width direction of the elastic layer, and T (mm) denotes a thickness of the central portion of the strip-shaped elastic member in a width direction before wound around the outer peripheral surface of the core.

2. The cleaning member according to claim 1 , wherein the cleaning member satisfies formula (2):

0.85 ≦t/T< 0.95  (2).

3. The cleaning member according to claim 1 , wherein a helical angle of the elastic layer is about 10° to about 65° and a helical width of the elastic layer is about 2 mm to about 18 mm,

4. A charging device comprising:

a charging member that charges a member to be charged; and

the cleaning member according to claim 1 in contact with a surface of the charging member and configured to clean the surface of the charging member.

5. An image forming apparatus comprising:

an image-carrying member;

a charginging unit including the charging device according to claim 4 , the charging unit configured to charge a surface of the image-carrying member;

a latent image-forming unit that forms a latent image on the charged surface of the image-carrying member;

a developing unit that develops the latent image on the surface of the image-carrying member into a visualized image; and

a transfer unit that transfers the visualized image to a receiving member,

6. A unit for an image forming apparatus, the unit comprising:

a member to be cleaned; and

the cleaning member according to claim 1 in contact with a surface of the member to be cleaned and configured to clean the surface of the member to be cleaned,

7. The unit according to claim 6 , wherein the unit is a process cartridge that is removably attachable to an image forming apparatus.

8. A process cartridge comprising:

the charging device according to claim 4 .

9. An image forming apparatus comprising;

the unit according to claim 6 ,

10. A cleaning member for an image forming apparatus, comprising:

a core; and

an elastic layer that is formed by a strip-shaped elastic member helically wound around an outer peripheral surface of the core,

wherein the cleaning member satisfies the following formula (3):

20%≦{ R 1/( R 1 +R 2)}×100≦70%  (3)

where R1 denotes a helical width of the elastic layer, and R2 denotes a helical pitch of the elastic layer.

11. The cleaning member according to claim 10 , wherein the cleaning member satisfies formula (4):

25%≦{ R 1/( R 1 +R 2)}×100≦55%  (4).