Image forming apparatus to remove foreign body from print media detection sensor

Patent metadata

Field	Value
Publication number	US-2025231527-A1
Application number	US-202218700117-A
Country	US
Kind code	A1
Filing date	Mar 28, 2022
Priority date	Oct 12, 2021
Publication date	Jul 17, 2025
Grant date	—

Abstract

An image forming apparatus including a fixer, a print medium detection sensor adjacent to the fixer and to detect movement of a print medium, a fan adjacent to the fixer and to the print medium sensor, and a processor to control the image forming apparatus to heat the fixer for an image forming job, and based on a voltage value of an output signal of the print medium detection sensor not being in a predetermined range, to drive the fan to remove a foreign body on a surface of the print medium detection sensor so that the voltage value of the output signal of the print medium detection sensor is in the predetermined range.

First claim

What is claimed is:

1 . An image forming apparatus comprising:
a fixer; a print medium detection sensor adjacent to the fixer and to detect movement of a print medium; a fan adjacent to the fixer and to the print medium sensor; and a processor to control the image forming apparatus to heat the fixer for an image forming job, and based on a voltage value of an output signal of the print medium detection sensor not being in a predetermined range, to drive the fan to remove a foreign body on a surface of the print medium detection sensor so that the voltage value of the output signal of the print medium detection sensor is in the predetermined range.

2 . The image forming apparatus according to claim 1 , wherein the processor comprises an analog-to-digital converter (ADC) port, the processor to receive an input of an output signal of the print medium detection sensor through the ADC port, and to determine whether a voltage value of the input output signal is in the predetermined range.

3 . The image forming apparatus according to claim 1 , wherein the processor, based on the voltage value of the output signal not being in the predetermined range during the image forming job, to stop the image forming job.

4 . The image forming apparatus according to claim 1 , further comprising:
an output interface, wherein the processor, based on the foreign body not being removed, to output information related to contamination of the print medium detection sensor through the output interface.

5 . The image forming apparatus according to claim 1 , further comprising:
a detection device, wherein the processor, based on the voltage value of the output signal of the print medium detection sensor not being in the predetermined range, to receive an input of a first signal through the detection device, and based on the first signal being input, to determine that the print medium detection sensor is contaminated with the foreign body.

6 . The image forming apparatus according to claim 5 , wherein the detection device comprising:
a first comparator to detect whether a voltage value of a high voltage output of the print medium detection sensor is less than a minimum threshold value, and a second comparator to detect whether a voltage value of a low voltage output of the print medium detection sensor is greater than a maximum threshold value, and the detection device, based on an output voltage value of the first comparator being less than the minimum threshold value and an output voltage value of the second comparator being greater than the maximum threshold value, to output the first signal.

7 . The image forming apparatus according to claim 6 , wherein the detection device comprises a voltage distribution resistor,
the first comparator to receive an input of a voltage of the minimum threshold value of the high voltage output of the print medium detection sensor through a positive terminal, to receive an input of a voltage value of the output signal through a negative terminal, and to operate as an open collector, and the second comparator to receive an input of a voltage of the maximum threshold value of the low voltage output of the print medium detection sensor through a negative terminal by the voltage distribution resistor, to receive an input of a voltage value of the output signal through a positive terminal, and to operate as an open collector.

8 . A method for controlling an image forming apparatus, the method comprising:
heating a fixer for an image forming job; and based on a voltage value of an output signal of the print medium detection sensor not being in a predetermined range, driving the fan to remove a foreign body on a surface of the print medium detection sensor so that the voltage value of the output signal of the print medium detection sensor is in the predetermined range.

9 . The method for controlling an image forming apparatus according to claim 8 , the method further comprising:
receiving an input of a voltage value of an output signal of the print medium detection sensor through an analog-to-digital converter (ADC) port of a processor; and determining whether the input voltage value of the output signal is in the predetermined range.

10 . The method for controlling an image forming apparatus according to claim 8 , the method further comprising:
based on the voltage value of the output signal not being in the predetermined range during the image forming job, stopping the image forming job.

11 . The method for controlling an image forming apparatus according to claim 8 , the method further comprising:
based on the foreign body not being removed, outputting information related to contamination of the print medium detection sensor.

12 . The method for controlling an image forming apparatus according to claim 8 , the method further comprising:
based on the voltage value of the output signal of the print medium detection sensor not being in the predetermined range, receiving an input of a first signal through the detection device; and based on the first signal being input, determining that the print medium detection sensor is contaminated with the foreign body.

13 . The method for controlling an image forming apparatus according to claim 12 , wherein the receiving the input of the first signal comprising:
by a first comparator of the detection device, detecting whether a voltage value of a high voltage output of the print medium detection sensor is less than a minimum threshold value, by a second comparator of the detection device, detecting whether a voltage value of a low voltage output of the print medium detection sensor is greater than a maximum threshold value, and by a processor, based on an output voltage value of the first comparator being less than the minimum threshold value and an output voltage value of the second comparator being greater than the maximum threshold value, receiving an input of the first signal output from the detection device.

14 . The method for controlling an image forming apparatus according to claim 13 , the method further comprising:
by the first comparator operating as an open collector, receiving an input of a voltage of the minimum threshold value of the high voltage output of the print medium detection sensor through a positive terminal and receiving an input of a voltage value of the output signal through a negative terminal; and by the second comparator operating as an open collector, receiving an input of a voltage of the maximum threshold value of the low voltage output of the print medium detection sensor through a negative terminal by a voltage distribution resistor and receiving an input of a voltage value of the output signal through a positive terminal.

15 . A non-transitory computer-readable medium on which a program for performing a method for controlling an image forming apparatus is recorded, the recording medium comprising:
instructions for heating a fixer for an image forming job; and instructions for, based on a voltage value of an output signal of a print medium detection sensor not being in a predetermined range, driving a fan so that the voltage value of the output signal of the print medium detection sensor is in the predetermined range by removing a foreign body on a surface of the print medium detection sensor.

Assignees

• Hewlett Packard Development Co

Inventors

• Choi Youngjun
• Kim Taegon
• Lee Seungkyu

Classifications

• G03G2221/1645

  for conducting air through the machine, e.g. cooling · CPC title

• G03G2215/00616

  Optical detector · CPC title

• G01N21/86

  Investigating moving sheets (G01N21/89 takes precedence) · CPC title

• G01N21/15

  Preventing contamination of the components of the optical system or obstruction of the light path · CPC title

• G03G2215/00721

  of sheet position · CPC title