Image forming apparatus

• US 8,543,037 B2
• Filed: 11/02/2009
• Issued: 09/24/2013
• Est. Priority Date: 11/14/2008
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Egawa, Kazuhiro, Fujiwara, Yukio, Kami, Hidetoshi, Ohshima, Kohichi
• Primary Examiner(s): RODEE, CHRISTOPHER D
• Application Number:
  US12/610,542
• Publication Number:
  US 20100124712A1
• Time in Patent Office: 1,422 Days
• Field of Search: 399/350, 399/231, 399/159, 430/119.82, 430/119.84
• US Class Current: 399/159
• CPC Class Codes: G03G 21/0011 using a blade; Details of cleaning blades, e.g. blade shape, layer forming
• CPC Class Codes: G03G 2215/00957 Compositions

Abstract

The image forming apparatus includes a photoreceptor bearing an electrostatic image; a developing device developing the electrostatic image with a developer including a toner to form a toner image on the photoreceptor; a transferring device transferring the toner image onto a receiving material; and a cleaning device having a cleaning blade cleaning the surface of the photoreceptor. The photoreceptor includes an electroconductive substrate, a photosensitive layer and an outermost layer having projected portions thereon. The outermost layer and projected portions include the same crosslinked charge transport material. The outermost layer has a surface roughness property such that the number of projected portions having height greater than Rz/2 is from 40 to 90 in a length of 12 mm, wherein Rz represents ten-point mean roughness of the outermost layer. The tip of the cleaning blade is contacted with the photoreceptor at a linear pressure of from 80 g/cm to 150 g/cm.

Claims

1. An image forming apparatus comprising:

at least one photoreceptor configured to bear an electrostatic latent image thereon, wherein the photoreceptor includes an electroconductive substrate, a photosensitive layer located overlying the substrate, and an outermost layer having projected portions thereon, wherein the outermost layer and the projected portions include a same crosslinked charge transport material, and wherein the outermost layer has a surface roughness property such that a number of projected portions having a height greater than Rz/2 is from 40 to 90 in a measurement length of 12 mm, wherein Rz represents ten-point mean roughness of a surface of the outermost layer;

a developing device configured to develop the electrostatic image with a developer including a toner to form a toner image on a surface of the photoreceptor;

a transferring device configured to transfer the toner image onto a receiving material; and

a cleaning device having a cleaning blade configured to clean the surface of the photoreceptor after the toner image is transferred, wherein a tip edge line of the cleaning blade is contacted with the surface of the photoreceptor at a linear pressure of from 80 g/cm to 150 g/cm, wherein

the projected portions form peaks and valleys on the surface of the outermost layer, and

the ten-point mean roughness Rz is a difference between (a) a mean value of altitude of from the highest peak to the fifth highest peak in a profile of the surface and (b) a mean value of altitude of from the deepest valley to the fifth deepest valley in the profile of the surface.

2. The image forming apparatus according to claim 1, wherein the projected portions have an average height of not greater than 5 μ

m in the scanning length of 12 mm.

3. The image forming apparatus according to claim 1, wherein the crosslinked charge transport material included in the outermost layer and the projected portions has a unit obtained from a triarylamine compound.

4. The image forming apparatus according to claim 3, wherein the triarylamine compound has the following formula (1):

5. The image forming apparatus according to claim 1, wherein projected portions are formed by a spray coating method.

6. The image forming apparatus according to claim 1, wherein the toner is a toner prepared by a polymerization method.

7. The image forming apparatus according to claim 1, including plural photoreceptors, wherein the developing device includes plural tandem developing units configured to form different color toner images on the respective photoreceptors.