Image forming apparatus

Patent metadata

Field	Value
Publication number	US-9723165-B1
Application number	US-201715402815-A
Country	US
Kind code	B1
Filing date	Jan 10, 2017
Priority date	Jan 22, 2016
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

An image forming apparatus capable of preventing misdetermination of a type of printing paper includes a transmitted light receiver, a specularly reflected light receiver, and a diffusively reflected light receiver, which constitute a sensor, and an output determiner that determines whether data output by the plurality of light receivers is normal. The image forming apparatus determines the type of printing paper and an abnormality of the printing paper from the determination by the output determiner.

First claim

What is claimed is:

1. An image forming apparatus, comprising:
a light emitter configured to radiate light to a recording medium;
a light receiver including a plurality of detectors configured to receive a portion of the light radiated to the recording medium and to respectively output independent detection results; and
an output determiner configured to determine a change in at least one of a conveying state of the recording medium and a relative arrangement between the light emitter and the light receiver, according to independent detection results respectively output by the plurality of detectors,
wherein the light receiver includes at least one of a transmitted light receiver configured to detect an amount of light transmitted by the recording medium from the light radiated by the light emitter, a specularly reflected light receiver configured to detect an amount of light specularly reflected by the recording medium from the light radiated by the light emitter, and a diffusively reflected light receiver configured to detect an amount of light diffusively reflected by the recording medium from the light radiated by the light emitter.

2. The image forming apparatus of claim 1 , wherein the independent detection results respectively output by the plurality of detectors are light receiving amounts detected by the plurality of detectors or degrees of relative change of the light receiving amounts.

3. The image forming apparatus of claim 2 , wherein, when a sum of the light receiving amounts of the plurality of detectors exceeds an upper bound of a range of a preset total light amount threshold or is less than a lower bound of the range of the preset total light amount threshold, the output determiner determines that the at least one of the conveying state of the recording medium and the relative arrangement between the light emitter and the light receiver is abnormal.

4. The image forming apparatus of claim 1 , wherein the light receiver includes at least three detectors, and each of the at least three detectors includes at least one detection device.

5. The image forming apparatus of claim 4 , wherein
the at least three detectors are arranged at regular intervals, and
the output determiner determines whether the at least one of the conveying state of the recording medium and the relative arrangement between the light emitter and the light receiver is abnormal, according to a difference between light receiving amounts of the at least three detectors.

6. The image forming apparatus of claim 5 , wherein
the at least three detectors are arranged at different locations in a direction perpendicular to a conveying direction of the recording medium on a plane defined by the recording medium, and
the output determiner determines whether the at least one of the conveying state of the recording medium and the relative arrangement between the light emitter and the light receiver is abnormal, according to a difference between light receiving amounts of the at least three detectors.

7. The image forming apparatus of claim 5 , wherein
the at least three detectors are arranged at different locations in a conveying direction of the recording medium, and
the output determiner determines whether the at least one of the conveying state of the recording medium and the relative arrangement between the light emitter and the light receiver is abnormal, according to a difference between light receiving amounts of the at least three detectors.

8. The image forming apparatus of claim 1 , wherein the light receiver has four detectors, and the four detectors are arranged in a lattice shape.

9. The image forming apparatus of claim 8 , wherein
when an intersection between an optical axis of the light radiated by the light emitter and the recording medium is defined as an origin point, the output determiner calculates a difference between a sum of light receiving amounts of one or more detectors among the four detectors that are arranged on one side of a direction perpendicular to a conveying direction of the recording medium and a sum of light receiving amounts of remaining detectors among the four detectors that are arranged on another side of the direction perpendicular to the conveying direction of the recording medium, and
when the difference exceeds a preset maximum threshold, the output determiner determines that the at least one of the conveying state of the recording medium and the relative arrangement between the light emitter and the light receiver is abnormal.

10. The image forming apparatus of claim 8 , wherein
when an intersection between an optical axis of the light radiated by the light emitter and the recording medium is defined as an origin point, the output determiner calculates a difference between a sum of light receiving amounts of one or more detectors among the four detectors that are arranged on one side of a conveying direction of the recording medium and a sum of light receiving amounts of remaining detectors among the four detectors that are arranged on another side of the conveying direction of the recording medium, and
when the difference exceeds a preset maximum threshold, the output determiner determines that the at least one of the conveying state of the recording medium and the relative arrangement between the light emitter and the light receiver is abnormal.

11. The image forming apparatus of claim 8 , wherein
when a sum of light receiving amounts of the detectors is less than or equal to a preset angle determination threshold, the output determiner defines an intersection between an optical axis of the light radiated by the light emitter and the recording medium as an origin point, and calculates a difference between a sum of the light receiving amounts of one or more detectors among the four detectors that are arranged on one side of a conveying direction of the recording medium and a sum of light receiving amounts of remaining detectors among the four detectors that are arranged on another side of the conveying direction of the recording medium, and
when the difference exceeds a preset shift determination threshold, the output determiner determines that at least one of the conveying state of the recording medium and the relative arrangement between the light emitter and the light receiver is abnormal.

12. The image forming apparatus of claim 8 , wherein
when a sum of light receiving amounts of the detectors is less than or equal to a preset angle determination threshold, the output determiner defines an intersection between an optical axis of the light radiated by the light emitter and the recording medium as an origin point, and calculates a difference between a sum of light receiving amounts of one or more detectors among the four detectors that are arranged on one side of a direction perpendicular to a conveying direction of the recording medium and a sum of light receiving amounts of remaining detectors among the four detectors that are arranged on another side of the direction perpendicular to the conveying direction of the recording medium, and
when the difference exceeds a preset shift determination threshold, the output determiner determines that at least one of the conveying state of the recording medium and the relative arrangement between the light emitter and the light receiver is abnormal.

13. The image forming apparatus of claim 8 , wherein
when a sum of light receiving amounts of the detectors is less than or equal to a preset angle determination threshold, the output determiner defines an intersection between an optical axis of the light radiated by the light emitter and the recording medium as an origin point, and calcul

Assignees

• S Printing Solution Co Ltd

Inventors

• Tomishima Yuichiro

Classifications

• H04N1/0075

  Detecting a change in reflectivity · CPC title

• H04N1/00769

  Comparing, e.g. with threshold · CPC title

• H04N1/00724 Primary

  Type of sheet, e.g. colour of paper or transparency · CPC title

• H04N1/00734

  Optical detectors · CPC title

• H04N2201/0082

  Image hardcopy reproducer (H04N2201/0091 - H04N2201/0094 take precedence) · CPC title