# US 2010/0166446 A1 · Image forming apparatus

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- Number: US 2010/0166446 A1
- Document ID: US20100166446A1
- Status: Published application
- Kind: A1
- Application number: 12/646,231
- Filed: 2009-12-23
- Published: 2010-07-01
- Earliest claimed: 2008-12-26
- Assignees: Brother Kogyo Kabushiki Kaisha
- Inventors: Hiroyuki NAGANAWA; Hiroyuki TSUJIHARA; Hiroaki NIWA; Shiro UENO
- Web page: https://patentgrep.com/patent/US20100166446A1

## CPC

- G03G 15/2039: {with means for controlling the fixing temperature}
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY

## Abstract

An image forming apparatus is provided. The image forming apparatus includes an image forming unit; a fuser having a heating unit to which an alternating voltage is applied from an alternating power supply so as to perform heating; a zero-cross pulse generating unit that generates a zero-cross pulse; a voltage estimating unit that estimates the alternating voltage on the basis of a width of the zero-cross pulse; a temperature detecting unit that detects the temperature of the fuser; a heating control parameter setting unit that sets a heating control parameter for controlling the heating unit on the basis of the alternating voltage estimated by the voltage estimating unit and the temperature of the fuser; and a heating control unit that controls the heating unit on the basis of the heating control parameter set by the heating control parameter setting unit.

## Claims

### Claim 1

An image forming apparatus comprising:
an image forming unit that forms an image on a printing medium;
a fuser that has a heating unit to which an alternating voltage is applied from an alternating power supply so as to perform heating, the fuser thermally fixing the image that is formed on the printing medium by the image forming unit;
a zero-cross pulse generating unit that generates a zero-cross pulse in accordance with a period when an absolute value of the alternating voltage is less than a predetermined value;
a voltage estimating unit that estimates the alternating voltage on the basis of a width of the zero-cross pulse generated by the zero-cross pulse generating unit;
a temperature detecting unit that detects the temperature of the fuser;
a heating control parameter setting unit that sets a heating control parameter for controlling the heating unit on the basis of the alternating voltage estimated by the voltage estimating unit and the temperature of the fuser detected by the temperature detecting unit; and
a heating control unit that controls the heating unit on the basis of the heating control parameter set by the heating control parameter setting unit.

### Claim 2

An image forming apparatus comprising:
an image forming unit that forms an image on a printing medium;
a fuser that has a heating unit to which an alternating voltage is applied from an alternating power supply so as to perform heating, the fuser thermally fixing the image that is formed on the printing medium by the image forming unit;
a zero-cross pulse generating unit that generates a zero-cross pulse in accordance with a period when an absolute value of the alternating voltage is less than a predetermined value;
a voltage estimating unit that estimates the alternating voltage on the basis of a width of the zero-cross pulse generated by the zero-cross pulse generating unit;
a temperature detecting unit that detects the temperature of the fuser;
an operation control unit that controls the heating unit until the temperature detected by the temperature detecting unit reaches a regulation temperature by applying the alternating voltage from the alternating power supply to the heating unit when the image forming apparatus is activated;
a time-out time setting unit that sets a time-out time related to the control of the operation control unit on the basis of the alternating voltage estimated by the voltage estimating unit; and
a fixation abnormality determining unit that determines abnormalities in the fuser when the temperature detected by the temperature detecting unit does not reach the regulation temperature after the operation control unit starts the control of the heating unit and the time-out time set by the time-out time setting unit has elapsed.

### Claim 3 (depends on 1)

The image forming apparatus according to claim 1, further comprising a power supply abnormality determining unit that determines abnormalities in the alternating power supply when the width of the zero-cross pulse generated by the zero-cross pulse generating unit is not within a predetermined range.

### Claim 4 (depends on 2)

The image forming apparatus according to claim 2, further comprising a power supply abnormality determining unit that determines abnormalities in the alternating power supply when the width of the zero-cross pulse generated by the zero-cross pulse generating unit is not within a predetermined range.