Image forming apparatus and method of detecting rise of recording medium

Patent metadata

Field	Value
Publication number	US-11611674-B2
Application number	US-202117332326-A
Country	US
Kind code	B2
Filing date	May 27, 2021
Priority date	Jun 25, 2020
Publication date	Mar 21, 2023
Grant date	Mar 21, 2023

Abstract

An image forming apparatus includes a reading table, an image reading device, an image forming device with an exposure device, and circuitry. The reading device reads a pattern on a recording medium on the table, and generates image data of the pattern. The exposure device includes a light emitting element to form an electrostatic latent image, based on which the image forming device forms the pattern. Based on first and second correction values, the circuitry calculates a third correction value to correct a light amount of the light emitting element. The exposure device includes a driving device that drives the light emitting element based on the third correction value. The circuitry sets at least two or more determination areas in each of a white area and a pattern area of the medium, and determines whether the medium has a rise based on density data in the determination areas.

First claim

The invention claimed is:

1. An image forming apparatus comprising:
a reading table;
an image reading device configured to read a pattern formed on a recording medium on the reading table and generate image data of the pattern;
an image forming device including an exposure device, the exposure device including a light emitting element that irradiates a surface of a photoconductor with light to form an electrostatic latent image on the surface of the photoconductor, the image forming device being configured to form the pattern on the recording medium based on the electrostatic latent image; and
circuitry configured to, based on a first correction value and a second correction value, calculate a third correction value to correct a light amount of the light emitting element, the first correction value being previously set to correct the light amount of the light emitting element, and the second correction value being calculated based on density data of the image data to correct the light amount of the light emitting element,
the exposure device further including an element driving device that drives the light emitting element in accordance with the third correction value, and
the circuitry
setting at least two or more determination areas in each of a white area and a density acquisition pattern area of the recording medium, and
prior to calculating the third correction value, determining presence or absence of a rise of the recording medium from the reading table based on the density data of the image data in the at least two or more determination areas.

2. The image forming apparatus of claim 1 , wherein the circuitry determines the presence or absence of the rise of the recording medium from the reading table based on
a result of comparison between a first threshold value and an absolute value of a difference in the density data between a plurality of determination areas of the at least two or more determination areas in the white area,
a result of comparison between a second threshold value and the density data of each determination area of the at least two or more determination areas in the white area,
a result of comparison between a third threshold value and an absolute value of a difference in the density data between a plurality of determination areas of the at least two or more determination areas in the density acquisition pattern area, and
a result of comparison between a fourth threshold value and the density data of each determination area of the at least two or more determination areas in the density acquisition pattern area.

3. The image forming apparatus of claim 1 , wherein when the at least two or more determination areas set in the density acquisition pattern area are four or more determination areas, the circuitry sets the four or more determination areas in the density acquisition pattern area, with at least two determination areas of the four or more determination areas in the density acquisition pattern area being included in each of two opposing edge portions of the recording medium.

4. The image forming apparatus of claim 1 , wherein when the at least two or more determination areas set in the density acquisition pattern area are four or more determination areas, the circuitry sets 4+2n determination areas in the density acquisition pattern area, n representing an integer equal to or greater than zero.

5. The image forming apparatus of claim 1 , wherein the circuitry controls the image forming device to move a position of the density acquisition pattern area formed on the recording medium.

6. The image forming apparatus of claim 1 , wherein the image forming device further includes
the photoconductor,
a charging device configured to charge the surface of the photoconductor,
a developing device configured to adhere toner to the electrostatic latent image to form a toner image,
a transfer device configured to transfer the toner image to the recording medium, and
a fixing device configured to fix the toner image on the recording medium,
wherein the exposure device further includes a memory configured to store the third correction value, and
wherein the element driving device reads the third correction value from the memory.

7. An image forming apparatus comprising:
a reading table;
image reading means for reading a pattern formed on a recording medium on the reading table and generating image data of the pattern;
image forming means for forming the pattern on the recording medium based on an electrostatic latent image, the image forming means including exposure means, the exposure means including light emitting means for irradiating a surface of a photoconductor with light to form the electrostatic latent image on the surface of the photoconductor; and
control means for, based on a first correction value and a second correction value, calculating a third correction value to correct a light amount of the light emitting means, the first correction value being previously set to correct the light amount of the light emitting means, and the second correction value being calculated based on density data of the image data to correct the light amount of the light emitting means,
the exposure means further including element driving means for driving the light emitting means in accordance with the third correction value, and
the control means
setting at least two or more determination areas in each of a white area and a density acquisition pattern area of the recording medium, and
prior to calculating the third correction value, determining presence or absence of a rise of the recording medium from the reading table based on the density data of the image data in the at least two or more determination areas.

8. The image forming apparatus of claim 7 , wherein the control means determines the presence or absence of the rise of the recording medium from the reading table based on
a result of comparison between a first threshold value and an absolute value of a difference in the density data between a plurality of determination areas of the at least two or more determination areas in the white area,
a result of comparison between a second threshold value and the density data of each determination area of the at least two or more determination areas in the white area,
a result of comparison between a third threshold value and an absolute value of a difference in the density data between a plurality of determination areas of the at least two or more determination areas in the density acquisition pattern area, and
a result of comparison between a fourth threshold value and the density data of each determination area of the at least two or more determination areas in the density acquisition pattern area.

9. The image forming apparatus of claim 7 , wherein when the at least two or more determination areas set in the density acquisition pattern area are four or more determination areas, the control means sets the four or more determination areas in the density acquisition pattern area, with at least two determination areas of the four or more determination areas in the density acquisition pattern area being included in each of two opposing edge portions of the recording medium.

10. The image forming apparatus of claim 7 , wherein when the at least two or more determination areas set in the density acquisition pattern area are four or more determination areas, the control means sets 4+2n determination areas in the density acquisition pattern area, n representing an integer equal to or greater than zero.

11. The image forming apparatus of claim 7 , wherein the control means controls the image forming means to move a position of the density acquisition pattern area

Assignees

• Morimoto Hidemasa
• Murota Koichi
• Hommi Masashi
• Osato Yuki
• Tomura Yuusuke
• Ricoh Co Ltd

Inventors

• Morimoto Hidemasa
• Murota Koichi
• Hommi Masashi
• Osato Yuki
• Tomura Yuusuke

Classifications

• H04N2201/0081

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

• H04N1/29 Primary

  involving production of an electrostatic intermediate picture · CPC title

• H04N1/00798

  Circuits or arrangements for the control thereof, e.g. using a programmed control device or according to a measured quantity · CPC title

• 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

• G03G15/22

  involving the combination of more than one step according to groups G03G13/02 - G03G13/20 (G03G15/01 takes precedence) · CPC title