Image forming apparatus and detection apparatus

• US 9,494,889 B2
• Filed: 10/31/2013
• Issued: 11/15/2016
• Est. Priority Date: 12/19/2012
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Tsuchiya, Toshikazu, Mukaibara, Takuya
• Primary Examiner(s): Lee, Susan
• Application Number:
  US14/442,009
• Publication Number:
  US 20150301470A1
• Time in Patent Office: 1,111 Days
• Field of Search: 399/49, 347/131
• US Class Current: 1/1
• CPC Class Codes: G03G 15/043 with means for controlling illumination or exposure G03G15/041 takes precedence
• CPC Class Codes: G03G 15/5058 using a test patch

Abstract

An image forming apparatus includes an irradiation unit for irradiating an image carrier having a formed detection image with light, the irradiation unit being capable of switching a size of a light-emitting region; a light-receiving unit for receiving reflected light of the light irradiated by the irradiation unit and outputting a detection signal corresponding to a light-receiving amount of the reflected light including a specular-reflected light component; a detection unit for detecting one of position information and density information of the detection image based on the detection signal; and a control unit for controlling to switch the size of the light-emitting region to detect one of the position information and the density information of the detection image.

Claims

1. A detection apparatus comprising:

an irradiation unit configured to irradiate an image carrier on which a detection image made of a developing material is formed with light, said irradiation unit being capable of switching a size of a light-emitting region to emit the light to irradiate;

a light-receiving unit configured to receive reflected light of the light irradiated by said irradiation unit and output a detection signal corresponding to a light-receiving amount of the reflected light including a specular-reflected light component;

a detection unit configured to detect one of position information and density information of the detection image based on a signal corresponding to a difference between a value of the detection signal corresponding to the light-receiving amount of the reflected light from a first position where the detection image is formed and the value of the detection signal corresponding to the light-receiving amount of the reflected light from a second position different from the first position during a time when the detection image formed on said image carrier passes through an irradiation region of said irradiation unit; and

a control unit configured to control to switch the size of the light-emitting region of said irradiation unit to detect one of the position information and the density information of the detection image.

2. An image forming apparatus comprising:

an image carrier;

a forming unit configured to form a detection image made of a developing material on said image carrier;

an irradiation unit configured to irradiate said image carrier having the formed detection image with light, said irradiation unit being capable of switching a size of a light-emitting region to emit the light to irradiate;

a light-receiving unit configured to receive reflected light of the light irradiated by said irradiation unit and output a detection signal corresponding to a light-receiving amount of the reflected light including a specular-reflected light component;

a detection unit configured to detect one of position information and density information of the detection image based on a signal corresponding to a difference between a value of the detection signal corresponding to the light-receiving amount of the reflected light from a first position where the detection image is formed and the value of the detection signal corresponding to the light-receiving amount of the reflected light from a second position different from the first position during a time when the detection image formed on said image carrier passes through an irradiation region of said irradiation unit; and

a control unit configured to control to switch the size of the light-emitting region of said irradiation unit to detect one of the position information and the density information of the detection image.

3. The apparatus according to claim 2, wherein said irradiation unit comprises:

a plurality of light-emitting elements having different light-emitting regions; and

a selection unit configured to select, from said plurality of light-emitting elements, the light-emitting element to irradiate said image carrier with the light.

4. The apparatus according to claim 2, wherein the detection image includes a plurality of lines in a direction different from a moving direction of the detection image, and

said forming unit is further configured to change one of a width of the plurality of lines and a pitch of the lines in accordance with a detection accuracy necessary for detection control.

5. The apparatus according to claim 2, wherein said control unit is further configured to perform control based on one of a signal-to-noise ratio of the detection signal and a speed of rise of the detection signal.

6. The apparatus according to claim 2, wherein said irradiation unit is further configured to irradiate said image carrier with a divergent beam.

7. The apparatus according to claim 2, wherein a position of an image to be formed is corrected using the position information, or a density of the image to be formed is corrected using the density information.

8. An image forming apparatus comprising:

an image carrier;

a forming unit configured to form a detection image made of a developing material on said image carrier;

an irradiation unit configured to irradiate said image carrier having the formed detection image with light, said irradiation unit being capable of switching a size of a light-emitting region to emit the light to irradiate;

a light-receiving unit configured to receive reflected light of the light irradiated by said irradiation unit and output a detection signal corresponding to a light-receiving amount of the reflected light including a specular-reflected light component;

a detection unit configured to detect one of position information and density information of the detection image based on a signal corresponding to a difference between a sum of values of the detection signals corresponding to at least one first time position and a sum of values of the detection signals corresponding to at least one second time position apart from the first time position by a predetermined period, which are detected during a time when the detection image formed on said image carrier passes through an irradiation region of said irradiation unit; and

a control unit configured to control to switch the size of the light-emitting region of said irradiation unit to detect one of the position information and the density information of the detection image.

9. The apparatus according to claim 8, wherein said control unit is further configure to perform control based on one of a signal-to-noise ratio of the detection signal and a speed of rise of the detection signal.

10. The apparatus according claim 8, wherein the value of the detection signal corresponding to the first time position is an average value in a first section of the detection signal, and the value of the detection signal corresponding to the second time position is an average value in a second section apart from the first section by the predetermined period.

11. A detection apparatus comprising:

an irradiation unit configured to irradiate an image carrier on which a detection image made of a developing material is formed with light, said irradiation unit being capable of switching a size of a light-emitting region to emit the light to irradiate;

a light-receiving unit configured to receive reflected light of the light irradiated by said irradiation unit and output a detection signal corresponding to a light-receiving amount of the reflected light including a specular-reflected light component;

a detection unit configured to detect one of position information and density information of the detection image based on a signal corresponding to a difference between a sum of values of the detection signals corresponding to at least one first time position and a sum of values of the detection signals corresponding to at least one second time position apart from the first time position by a predetermined period, which are detected during a time when the detection image formed on said image carrier passes through an irradiation region of said irradiation unit; and

a control unit configured to control to switch the size of the light-emitting region of said irradiation unit to detect one of the position information and the density information of the detection image.

12. An image forming apparatus comprising:

an image carrier;

a forming unit configured to form a detection image made of a developing material on said image carrier;

an irradiation unit configured to irradiate said image carrier having the formed detection image with light, said irradiation unit being capable of switching a size of a light-emitting region to emit the light to irradiate;

at least one first light-receiving unit configured to receive reflected light of the light irradiated by said irradiation unit and output a first detection signal corresponding to a light-receiving amount of the reflected light including a specular-reflected light component;

at least one second light-receiving unit configured to receive the reflected light of the light irradiated by said irradiation unit and output a second detection signal corresponding to the light-receiving amount of the reflected light including the specular-reflected light component;

a detection unit configured to detect one of position information and density information of the detection image based on a signal corresponding to a difference between a sum of values of the first detection signals output from said first light-receiving unit and a sum of values of the second detection signals output from said second light-receiving unit during a time when the detection image formed on said image carrier passes through an irradiation region of said irradiation unit; and

a control unit configured to control to switch the size of the light-emitting region of said irradiation unit to detect one of the position information and the density information of the detection image.

13. The apparatus according to claim 12, wherein said control unit is further configured to perform control based on one of a signal-to-noise ratio of each of the first detection signals and the second detection signals and a speed of rise of each of the first detection signals and the second detection signals.

14. A detection apparatus comprising:

an irradiation unit configured to irradiate an image carrier on which a detection image made of a developing material is formed with light, said irradiation unit being capable of switching a size of a light-emitting region to emit the light to irradiate;

at least one first light-receiving unit configured to receive reflected light of the light irradiated by said irradiation unit and output a first detection signal corresponding to a light-receiving amount of the reflected light including a specular-reflected light component;

at least one second light-receiving unit configured to receive the reflected light of the light irradiated by said irradiation unit and output a second detection signal corresponding to the light-receiving amount of the reflected light including the specular-reflected light component;

a detection unit configured to detect one of position information and density information of the detection image based on a signal corresponding to a difference between a sum of values of the first detection signals output from said first light-receiving unit and a sum of values of the second detection signals output from said second light-receiving unit during a time when the detection image formed on said image carrier passes through an irradiation region of said irradiation unit; and

a control unit configured to control to switch the size of the light-emitting region of said irradiation unit to detect one of the position information and the density information of the detection image.