Image forming apparatus and image forming method

Patent metadata

Field	Value
Publication number	US-2016349639-A1
Application number	US-201514922779-A
Country	US
Kind code	A1
Filing date	Oct 26, 2015
Priority date	May 28, 2015
Publication date	Dec 1, 2016
Grant date	—

Abstract

An image forming apparatus includes an electrophotographic photoreceptor, a charging unit; an electrostatic latent image forming unit, a developing unit that stores a developer containing a toner, a transfer unit, a cleaning unit and a fixation unit, wherein the toner has a sea and island structure of a sea portion containing the binder resin and an island portion containing the release agent, a maximum frequent value of the eccentricity B of the island portion containing the release agent is in a range of from 0.75 to 0.95, and a skewness of the eccentricity B is in a range of from −1.10 to −0.50.

First claim

What is claimed is:

1 . An image forming apparatus comprising:
an electrophotographic photoreceptor that includes a charge generation layer, a charge transport layer, and an overcoat layer on an electroconductive substrate; a charging unit that charges a surface of the electrophotographic photoreceptor; an electrostatic latent image forming unit that forms an electrostatic latent image on the charged surface of the electrophotographic photoreceptor; a developing unit that stores a developer containing a toner and develops the electrostatic latent image formed on the surface of the electrophotographic photoreceptor by using the developer so as to form a toner image; a transfer unit that transfers the toner image onto a surface of a recording medium; a cleaning unit that includes a cleaning blade which contacts with the electrophotographic photoreceptor and removes residual substances on the surface of the electrophotographic photoreceptor; and a fixation unit that fixes the toner image transferred to the recording medium, wherein the toner contains a binder resin, a colorant, and a release agent and has a sea and island structure of a sea portion containing the binder resin and an island portion containing the release agent, a maximum frequent value in distribution of the following eccentricity B of the island portion containing the release agent is in a range of from 0.75 to 0.95, and a skewness in the distribution of the following eccentricity B is in a range of from −1.10 to −0.50, the eccentricity B being represented by the following expression (1):
Eccentricity B= 2 d/D   (1)

wherein D indicates an equivalent circle diameter (μm) of the toner in an observation of a cross-section of the toner, and d indicates a distance (μm) from the centroid of the toner to the centroid of the island portion containing the release agent in the observation of a cross-section of the toner.

2 . The image forming apparatus according to claim 1 ,
wherein the overcoat layer of the electrophotographic photoreceptor contains a siloxane resin.

3 . The image forming apparatus according to claim 1 ,
wherein a rotation speed of the electrophotographic photoreceptor is equal to or greater than 300 mm/s.

4 . The image forming apparatus according to claim 1 ,
wherein a fixation temperature by the fixation unit is equal to or higher than 100° C. and lower than 190° C.

5 . The image forming apparatus according to claim 1 ,
wherein a kurtosis of the distribution of the eccentricity B in the toner is in a range of from −0.20 to +1.50.

6 . An image forming method comprising:
charging a surface of an electrophotographic photoreceptor that includes a charge generation layer, a charge transport layer, and an overcoat layer on an electroconductive substrate; forming an electrostatic latent image on the charged surface of the electrophotographic photoreceptor; developing the electrostatic latent image formed on the surface of the electrophotographic photoreceptor by using a developer containing a toner so as to form a toner image; transferring the toner image to a surface of a recording medium; removing residual substances on the surface of the electrophotographic photoreceptor by using a cleaning blade which contacts with the electrophotographic photoreceptor; and fixing the toner image transferred to the recording medium, wherein the toner contains a binder resin, a colorant, and a release agent, and has a sea and island structure of a sea portion containing the binder resin and an island portion containing the release agent, a maximum frequent value in distribution of the following eccentricity B of the island portion containing the release agent is in a range of from 0.75 to 0.95, and a skewness in the distribution of the following eccentricity B is in a range of from −1.10 to −0.50, the eccentricity B being represented by the following expression (1):
Eccentricity B= 2 d/D   (1)

wherein D indicates an equivalent circle diameter (μm) of the toner in an observation of a cross-section of the toner, and d indicates a distance (μm) from a centroid of the toner to a centroid of the island portion containing the release agent in the observation of a cross-section of the toner.

7 . The image forming method according to claim 6 ,
wherein the overcoat layer of the electrophotographic photoreceptor contains a siloxane resin.

8 . The image forming method according to claim 6 ,
wherein a rotation speed of the electrophotographic photoreceptor is equal to or greater than 300 mm/s.

9 . The image forming method according to claim 6 ,
wherein a fixation temperature in the fixing is equal to or higher than 100° C. and lower than 190° C.

10 . The image forming method according to claim 6 ,
wherein a kurtosis of the distribution of the eccentricity B in the toner is in a range of from −0.20 to +1.50.

Assignees

• Fuji Xerox Co Ltd

Inventors

• Ota Naoki
• Kitajima Katsuyuki

Classifications

• G03G9/087 Primary

  Binders for toner particles · CPC title

• G03G9/0819 Primary

  characterised by the dimensions of the particles · CPC title

• G03G9/0825

  characterised by their structure; characterised by non-homogenuous distribution of components (microcapsular toners G03G9/093) · CPC title

• G03G15/02

  for laying down a uniform charge, e.g. for sensitising; Corona discharge devices (G03G15/14 takes precedence) · CPC title