Image formation apparatus
View Patent ↗An image formation apparatus includes a photoreceptor, a charge unit, an exposure unit, a development unit, and a transfer unit. The photoreceptor satisfies the following formulas. 0.9≦(| V 0 (2)− VL |)/(| V 0 (1)− VL |)≦1.0 2.0≦| VL|/L ≦3.5 VL denotes a post-exposure surface potential value [V] of a surface portion of the photoreceptor exposed by the exposure unit in a first image formation cycle; V 0 ( 2 ) denotes a charge potential value [V] in a second image formation cycle of a surface portion of the photoreceptor exposed by the exposure unit in the first image formation cycle; V 0 ( 1 ) denotes a charge potential value [V] in a second image formation cycle of a surface portion of the photoreceptor not exposed by the exposure unit in the first image formation cycle; and L denotes a film thickness [μm] of the photosensitive layer.
1. An image formation apparatus for forming an image comprising:
a photoreceptor including a surface comprising a photosensitive layer;
a charge unit configured to charge the surface of the photoreceptor;
an exposure unit configured to emit light to the surface of the photoreceptor charged by the charge unit and to form an electrostatic latent image on the surface of the photoreceptor;
a development unit configured to feed a developer to the electrostatic latent image and thereby develop a developer image on the surface of the photoreceptor; and
a transfer unit configured to transfer the developer image onto a transfer target, wherein the photoreceptor satisfies both of the following formulae:
0.9≦(| V 0 (2)− VL |)/(| V 0 (1)− VL |)≦1.0,
and
2.0≦| VL|/L≦ 3.5
where
VL denotes a post-exposure surface potential value [V] of a surface portion of the photoreceptor exposed by the exposure unit in a first image formation cycle,
V 0 ( 2 ) denotes a charge potential value [V] in a second image formation cycle of a surface portion of the photoreceptor exposed by the exposure unit in the first image formation cycle,
V 0 ( 1 ) denotes a charge potential value [V] in a second image formation cycle of a surface portion of the photoreceptor not exposed by the exposure unit in the first image formation cycle, and
L denotes a film thickness [μm] of the photosensitive layer.
2. The image formation apparatus according to claim 1 , wherein
the photoreceptor satisfies both of the following formulae:
0.9≦(| V 0 (2)− VL |)/(| V 0 (1)− VL |)≦0.98, and
1.5≦| VL|/L≦ 3.5.
3. The image formation apparatus according to claim 1 , wherein
the photoreceptor satisfies both of the following formulae:
0.92≦(| V 0 (2)− VL |)/(| V 0 (1)− VL |)≦0.97, and
2.5≦| VL|/L≦ 3.0.
4. The image formation apparatus according to claim 1 , further comprising
a charge elimination unit configured to emit charge elimination light to the surface of the photoreceptor, wherein
the charge elimination unit is provided between the transfer unit and the charge unit.
5. The image formation apparatus according to claim 1 , wherein
a distance L that the surface of the photoreceptor travels from an image transfer position between the photoreceptor and the transfer unit to a charge position between the photoreceptor and the charge unit is not less than 18 [mm] and not more than 47 [mm].
6. The image formation apparatus according to claim 5 , wherein
the photoreceptor is configured to rotate at a rotational speed in the range of from 90 to 180 rpm.
7. The image formation apparatus according to claim 1 , further comprising
a charge elimination unit configured to emit charge elimination light to the surface of the photoreceptor, wherein
an amount of the charge elimination light is at least not less than 0.6 μj/cm 2 and not more than 4.8 μj/cm 2 .
8. The image formation apparatus according to claim 1 , further comprising
a charge elimination unit configured to emit charge elimination light to the surface of the photoreceptor, wherein
the amount of the charge elimination light is at least not less than 1.0 μj/cm 2 and not more than 3.8 μj/cm 2 .
9. The image formation apparatus according to claim 1 , further comprising
a charge elimination unit configured to emit charge elimination light to the surface of the photoreceptor, wherein
the amount of the charge elimination light is at least not less than 1.6 μj/cm 2 and not more than 3.2 μj/cm 2 .
10. The image formation apparatus according to claim 1 , wherein
the charge unit comprises a charge roller, and the transfer unit comprises a transfer roller.
11. The image formation apparatus according to claim 10 , wherein
the development unit comprises a development roller.
12. The image formation apparatus according to claim 10 , further comprising
a transfer belt provided between the photoreceptor and the transfer roller.
13. The image formation apparatus according to claim 1 , wherein
the potential values of the surface of the photoreceptor are measured at a position on the surface of the photoreceptor where the development unit is disposed.
14. The image formation apparatus according to claim 1 , further comprising
a charge elimination unit configured to emit charge elimination light to the surface of the photoreceptor, wherein
the image formation apparatus is configured to form an image by performing, as a cycle, the steps of: charging by the charge unit; exposing by the exposure unit; developing by the development unit; transferring by the transfer unit; and eliminating charges by the charge elimination unit.
15. The image formation apparatus according to claim 1 , further comprising
a charge elimination unit configured to emit charge elimination light to the surface of the photoreceptor, wherein
the image formation apparatus is configured to form an image by performing, as a cycle, the steps of: charging by the charge unit; exposing by the exposure unit; developing by the development unit; transferring by the transfer unit; and eliminating charges by the charge elimination unit, in this order.