Transfer belt and image forming apparatus

Patent metadata

Field	Value
Publication number	US-9983520-B2
Application number	US-201715634712-A
Country	US
Kind code	B2
Filing date	Jun 27, 2017
Priority date	Jul 5, 2016
Publication date	May 29, 2018
Grant date	May 29, 2018

Abstract

A transfer belt is configured to transfer a toner image carried on a first main surface of the transfer belt to a recording medium. When the transfer belt is pressed with pressure application three increased at a predetermined pressure application rate and is then pressed with certain pressure application force by using a lower block provided with a hole and an upper block, k 2 [μm/s] satisfies 6≤k 2 ≤30, k 2 [μm/s] being determined by (a−b)/{2×(t 2 −t 1 )}, where a [μm/s] represents a maximum value of a displacement amount of a measurement region that is a portion of the first main surface corresponding to the hole, b [μm] represents a convergence value thereof, t 1 [s] represents a time when the maximum value is observed, and t 2 [s] represents a time when the displacement amount reaches (a+b)/2 again after the maximum value is observed.

First claim

What is claimed is:

1. A transfer belt at least comprising an elastic layer, the transfer belt having a pair of exposed main surfaces constituted of a first main surface and a second main surface located opposite to each other, the transfer belt being for transferring a toner image carried on the first main surface to a recording medium,
k 2 [μm/s] satisfying 6≤k 2 ≤30 when a pressed region of the transfer belt is pressed at a pressure application rate of 4 [kPa/ms] until pressure application force reaches 200 [kPa] and then is uniformly pressed under the pressure application force of 200 [kPa] by using a lower block that has an upper surface having a protrusively curved elongated surface having a width of 20 [mm] and a curvature radius of 20 [mm] and that is provided with a hole formed at a top of the protrusively curved elongated surface and having a diameter of 1.25 [mm] and an upper block that has a lower surface having a recessively curved elongated surface having a width of 20 [mm] and a curvature radius of 20.3 [mm] so as to place the transfer belt on the upper surface of the lower block such that the first main surface faces the upper surface of the lower block and so as to sandwich a portion of the transfer belt between the protrusively curved elongated surface and the recessively curved elongated surface by lowering the upper block toward the lower block, the pressed region of the transfer belt being the portion of the transfer belt sandwiched between the protrusively curved elongated surface and the recessively curved elongated surface,
k 2 [μm/s] being determined by (a−b)/{2×(t 2 −t 1 )}, where a [μm] represents a maximum value of a displacement amount of a measurement region that is a portion of the first main surface corresponding to the hole, b [μm] represents the displacement amount of the measurement region after the displacement of the measurement region is converged, t 1 [s] represents a period of time from a point of time at which the pressed region is started to be pressed to a point of time at which the maximum value of the displacement amount of the measurement region is observed, and t 2 [s] represents a period of time from the point of time at which the pressed region is started to be pressed to a point of time at which the displacement amount of the measurement region reaches (a+b)/2 again after the maximum value of the displacement amount of the measurement region is observed.

2. The transfer belt according to claim 1 , wherein b further satisfies 4≤b≤8.

3. The transfer belt according to claim 1 , further comprising a base layer and a front layer in addition to the elastic layer, wherein
the first main surface is defined by the front layer by providing the elastic layer to cover the base layer and providing the front layer to cover the elastic layer.

4. An image forming apparatus comprising:
an image carrier and an intermediate transfer belt that both carry a toner image;
a primary transfer portion that transfers the toner image carried by the image carrier to the intermediate transfer belt; and
a secondary transfer portion that transfers the toner image carried by the intermediate transfer belt to a recording medium,
the secondary transfer portion including a secondary transfer roller, a counter roller facing the secondary transfer roller, and a nip portion formed by the secondary transfer roller and the counter roller,
the intermediate transfer belt being disposed to pass through the nip portion,
the transfer belt recited in claim 1 being used as the intermediate transfer belt.

5. The image forming apparatus according to claim 4 , wherein
the first main surface of the intermediate transfer belt is disposed to face the secondary transfer roller, and
the secondary transfer roller has a surface having a hardness higher than a hardness of a surface of the counter roller.

6. The image forming apparatus according to claim 4 , wherein the secondary transfer roller has a diameter of not less than 20 [mm] and not more than 60 [mm].

7. The image forming apparatus according to claim 4 , wherein a maximum pressure in the nip portion is not less than 100 [kPa] and not more than 400 [kPa].

Assignees

• Konica Minolta Inc

Inventors

• Tabata Eiji
• Mizumoto Nofumi
• Natsuhara Toshiya
• Uetake Shigeo
• Momotani Keiko
• Watanabe Makiko

Classifications

• G03G15/162 Primary

  details of the the intermediate support, e.g. chemical composition · CPC title

• G03G15/169 Primary

  with means for preconditioning the toner image before the transfer (G03G15/095 and G03G15/11 take precedence) · CPC title

• G03G15/1685

  Structure, details of the transfer member, e.g. chemical composition · CPC title