# US 12,222,668 B2 · Image forming apparatus capable of adjusting emission light amount of light-emitting portion, and light amount adjustment method

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- Number: US 12,222,668 B2
- Document ID: US12222668B2
- Status: Granted
- Kind: B2
- Application number: 18/475,521
- Filed: 2023-09-27
- Published: 2024-03-28
- Granted: 2025-02-11
- Earliest claimed: 2022-09-28
- Assignees: KYOCERA Document Solutions Inc.
- Applicants: KYOCERA Document Solutions Inc.
- Inventors: Ayato Morikami; Yasuaki Sakamoto; Masaru Watanabe
- Web page: https://patentgrep.com/patent/US12222668B2

## CPC

- G03G 15/5041: {Detecting a toner image, e.g. density, toner coverage, using a test patch (G03G15/553 takes precedence)}
- G03G 15/5058: {using a test patch}
- G03G 2215/00042: Optical detection
- G03G 2215/00059: on intermediate image carrying member, e.g. transfer belt
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY

## Abstract

An image forming apparatus includes first to third adjustment processing portions. The first adjustment processing portion adjusts an emission light amount of a light-emitting portion of a first sensor based on an electric signal output from a light-receiving portion of the first sensor and corresponding to regular reflection light reflected by a non-toner-adhering surface of an image-carrying member. The second adjustment processing portion adjusts an operation condition of an image forming portion based on a toner concentration of a first toner image in a specific color, that has a concentration smaller than a predetermined saturation concentration. The third adjustment processing portion adjusts an emission light amount of a light-emitting portion of a second sensor based on an electric signal output from a light-receiving portion of the second sensor and corresponding to diffuse reflection light reflected by a second toner image in the specific color, that has a predetermined reference concentration.

## Claims

### Claim 1

An image forming apparatus, comprising:
an image-carrying member which carries a toner image;
a specific toner image forming portion which forms a toner image on the image-carrying member using toner of a predetermined specific color different from black;
a first concentration sensor which includes a first light-emitting portion which emits light toward the image-carrying member and a first light-receiving portion which receives regular reflection light that is emitted from the first light-emitting portion and reflected by the image-carrying member and outputs an electric signal corresponding to a received light amount, the first concentration sensor being used to sense a toner concentration of a black toner image formed on the image-carrying member;
a second concentration sensor which includes a second light-emitting portion which emits light toward the image-carrying member and a second light-receiving portion which receives diffuse reflection light that is emitted from the second light-emitting portion and reflected by the image-carrying member and outputs an electric signal corresponding to a received light amount, the second concentration sensor being used to sense a toner concentration of a toner image in the specific color, that is formed on the image-carrying member;
a first adjustment processing portion which adjusts an emission light amount of the first light-emitting portion based on an electric signal that is output from the first light-receiving portion and corresponds to regular reflection light reflected by a surface of the image-carrying member where toner has not adhered;
a second adjustment processing portion which adjusts an operation condition of the specific toner image forming portion based on a toner concentration of a first toner image in the specific color, that has a concentration smaller than a predetermined saturation concentration, the toner concentration of the first toner image being sensed by the first concentration sensor after the adjustment of the emission light amount of the first light-emitting portion by the first adjustment processing portion; and
a third adjustment processing portion which adjusts an emission light amount of the second light-emitting portion based on an electric signal that is output from the second light-receiving portion and corresponds to diffuse reflection light reflected by a second toner image in the specific color, that has a predetermined reference concentration, the second toner image having been formed by the specific toner image forming portion after the adjustment of the operation condition by the second adjustment processing portion.

### Claim 2 (depends on 1)

The image forming apparatus according to claim 1, further comprising
a plurality of toner image forming portions which are provided to respectively correspond to a plurality of predetermined colors different from black, and form toner images on the image-carrying member using toner of the plurality of colors respectively corresponding thereto,
wherein the specific color is a color with which a reflected amount of light emitted from the first light-emitting portion becomes smallest out of the plurality of colors respectively corresponding to the plurality of toner image forming portions.

### Claim 3

A light amount adjustment method executed in an image forming apparatus including: an image-carrying member which carries a toner image; a specific toner image forming portion which forms a toner image on the image-carrying member using toner of a predetermined specific color different from black; a first concentration sensor which includes a first light-emitting portion which emits light toward the image-carrying member and a first light-receiving portion which receives regular reflection light that is emitted from the first light-emitting portion and reflected by the image-carrying member and outputs an electric signal corresponding to a received light amount, the first concentration sensor being used to sense a toner concentration of a black toner image formed on the image-carrying member; and a second concentration sensor which includes a second light-emitting portion which emits light toward the image-carrying member and a second light-receiving portion which receives diffuse reflection light that is emitted from the second light-emitting portion and reflected by the image-carrying member and outputs an electric signal corresponding to a received light amount, the second concentration sensor being used to sense a toner concentration of a toner image in the specific color, that is formed on the image-carrying member, the light amount adjustment method comprising:
a first adjustment step of adjusting an emission light amount of the first light-emitting portion based on an electric signal that is output from the first light-receiving portion and corresponds to regular reflection light reflected by a surface of the image-carrying member where toner has not adhered;
a second adjustment step of adjusting an operation condition of the specific toner image forming portion based on a toner concentration of a first toner image in the specific color, that has a concentration smaller than a predetermined saturation concentration, the toner concentration of the first toner image being sensed by the first concentration sensor after the adjustment of the emission light amount of the first light-emitting portion in the first adjustment step; and
a third adjustment step of adjusting an emission light amount of the second light-emitting portion based on an electric signal that is output from the second light-receiving portion and corresponds to diffuse reflection light reflected by a second toner image in the specific color, that has a predetermined reference concentration, the second toner image having been formed by the specific toner image forming portion after the adjustment of the operation condition in the second adjustment step.