Image forming apparatus

Patent metadata

Field	Value
Publication number	US-2020285176-A1
Application number	US-202016798986-A
Country	US
Kind code	A1
Filing date	Feb 24, 2020
Priority date	Mar 7, 2019
Publication date	Sep 10, 2020
Grant date	—

Abstract

An image forming apparatus includes an image bearing member, a transfer member, a voltage source, a sensor configured to detect a current value or a voltage value, an image detecting portion, and a controller capable of executing an operation in a mode for setting a transfer voltage to be applied to the transfer member, on the basis of a result of detection of a test chart formed on a test recording material. The controller sets the transfer voltage on the basis of a first detection result acquired by the sensor under application of a voltage to the transfer member when the recording material is absent in the transfer portion and a second detection result acquired by the sensor under application of the test voltages to the transfer member when the test recording material is present in said transfer portion during the operation in the mode.

First claim

What is claimed is:

1 . An image forming apparatus comprising:
an image bearing member configured to bear a toner image; a transfer member configured to transfer the toner image from said image bearing member onto a recording material at a transfer portion under application of a voltage; a voltage source configured to apply the voltage to said transfer member; a sensor configured to detect a current value or a voltage value when the voltage is applied from said voltage source to said transfer member; an image detecting portion configured to detect an image on the recording material; and a controller capable of executing an operation in a mode for setting a transfer voltage to be applied to said transfer member when the toner image is transferred onto the recording material, on the basis of a result of detection such that test images are transferred onto a test recording material by applying a plurality of different transfer voltages from said voltage source to said transfer member to produce test chart, and then the test chart is detected by said image detecting portion, wherein said controller sets the transfer voltage on the basis of a first detection result acquired by said sensor under application of a voltage to said transfer member when the recording material is absent in said transfer portion and a second detection result acquired by said sensor under application of the test voltages to said transfer member when the test recording material is present in said transfer portion during the operation in the mode.

2 . An image forming apparatus according to claim 1 , wherein during the operation in the mode, said controller sets the transfer voltage on the basis of information on a thickness of the test recording material.

3 . An image forming apparatus according to claim 1 , wherein the first detection result is a relationship between the voltage and the current acquired by said sensor under application of voltages of a plurality of levels from said voltage source to said transfer member when the recording material is absent in said transfer portion.

4 . An image forming apparatus according to claim 3 , wherein the relationship is a first relationship and said controller sets the transfer voltage on the basis of the first relationship and a second relationship between the voltage and the current acquired by said sensor under application of voltages of a plurality of levels from said voltage source to said transfer member when the test recording material is present in said transfer portion.

5 . An image forming apparatus according to claim 4 , wherein said controller sets the transfer voltage on the basis an information on a difference of the first relationship and the second relationship, a third relationship between information on a thickness of the recording material and an upper limit with respect to the difference, and the information on the thickness of the test recording material.

6 . An image forming apparatus according to claim 1 , wherein the second detection result is a detection result by said sensor acquired when the test images are transferred onto the recording material.

7 . An image forming apparatus according to claim 1 , wherein the first detection result is a detection result by said sensor acquired when the recording material is absent in said transfer portion in a period from input of an instruction to output the test chart to said controller until the test chart is outputted.

8 . An image forming apparatus according to claim 1 , wherein during the operation in the mode, said controller performs a process of notifying information on the transfer voltage set by said controller.

9 . An image forming apparatus according to claim 1 , wherein during the operation in the mode, said controller is capable of receiving an instruction to change the transfer voltage set by said controller.

10 . An image forming apparatus according to claim 2 , wherein the information on the thickness is information on the thickness of the recording material, a basis weight of the recording material or a kind of the recording material based on the thickness of the recording material or the basis weight of the recording material.

11 . An image forming apparatus according to claim 1 , wherein said image detecting portion detects a density of the test image on the test chart by being supplied with the test chart outputted from said image forming apparatus.

12 . An image forming apparatus according to claim 1 , wherein said image detecting portion detects a density of the test image on the test chart when the test chart is outputted from said image forming apparatus.

13 . An image forming apparatus according to claim 1 , wherein said image bearing member is an intermediary transfer member configured to feed the toner image, primary-transferred from another image bearing member, to the recording material for secondary transfer.

14 . An image forming apparatus according to claim 1 , wherein said transfer member contacts said image bearing member and forms said transfer portion, where the recording material is nipped and fed, between itself and said image bearing member.

Assignees

• Canon Kk

Inventors

• Sueoka Takenori

Classifications

• G03G15/50

  Machine control of apparatus for electrographic processes using a charge pattern, e.g. regulating differents parts of the machine, multimode copiers, microprocessor control (sequencing control G03G21/14) · CPC title

• G03G15/14 Primary

  for transferring a pattern to a second base · CPC title

• G03G15/5058

  using a test patch · CPC title

• G03G15/1675 Primary

  with means for controlling the bias applied in the transfer nip · CPC title