Image forming apparatus and detecting device

• US 20020071688A1
• Filed: 12/07/2001
• Published: 06/13/2002
• Est. Priority Date: 12/12/2000
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Maruyama, Shoji
• Granted Patent: US 6,668,144 B2
• Time in Patent Office: Days
• US Class Current: 399/45
• CPC Class Codes: H04N 1/00681 Detecting the presence, position or size of a sheet or correcting its position before scanning H04N1/047 takes precedence; mode signalling H04N1/333; skew detection or correction in image signals H04N1/3878
• CPC Class Codes: H04N 1/00716 Thickness
• CPC Class Codes: H04N 1/00734 Optical detectors
• CPC Class Codes: H04N 1/00779 Adjusting settings, e.g. mode, feeding rate or type of paper
• CPC Class Codes: H04N 1/2323 according to characteristics of the reproducing medium, e.g. type, size or availability
• CPC Class Codes: H04N 1/295 Circuits or arrangements for the control thereof, e.g. using a programmed control device, according to a measured quantity

Abstract

An image forming apparatus which achieves improvements in usability and cost performance and yet can effect the fixing process on recording materials of various types under an optimum fixing process condition to thereby obtain good fixed images. The image forming apparatus is provided with an LED for applying a light to the surface of a recording material before fixed, a CMOS for reading and outputting the interior of that area of the surface of the recording material to which the light is applied by the LED as a picture, and a fixing condition setting device for controlling so as to set the fixing process condition of a fixing device correspondingly to the output value from the CMOS.

Claims

1. An image forming apparatus comprising:

feeding means for feeding a sheet;

image forming means for forming an image on the sheet fed by said feeding means;

reading means for reading a picture of a surface of the sheet fed by said feeding means;

discriminating means for discriminating whether a rereading is necessary or not, on the basis of the picture read by said reading means;

means for changing a reading condition of said reading means and causing said reading means to reread a picture of an edge portion of the sheet, on the basis of a fact that it has been discriminated by said discriminating means that the rereading is necessary;

detecting means for detecting a type of the sheet on the basis of the picture read by said reading means; and

control means for controlling an image forming condition of said image forming means on the basis of a result of detection by said detecting means.

2. An image forming apparatus according to claim 1, wherein said detecting means detects that the sheet is plain paper.

3. An image forming apparatus according to claim 1, wherein said detecting means detects that the sheet is rough paper.

4. An image forming apparatus according to claim 1, wherein said detecting means detects that the sheet is glossy paper.

5. An image forming apparatus according to claim 1, wherein said reading means includes:

irradiating means for irradiating the sheet;

light receiving means for receiving a light from said irradiating means reflected back from the sheet; and

converting means for digitizing an output of said light receiving means.

6. An image forming apparatus according to claim 5, wherein said light receiving means includes a CMOS sensor.

7. An image forming apparatus according to claim 5, wherein said means for causing said reading means to reread the picture changes a gain of said converting means.

8. An image forming apparatus according to claim 5, wherein said reading means includes calculating means for filter-calculating an output from said converting means, and said means for causing said reading means to reread the picture changes calculation parameters of said calculating means.

9. An image forming apparatus according to claim 1, wherein said image forming means includes:

transferring means for transferring a toner image to the sheet; and

fixing means for fixing the toner image transferred by said transferring means on the sheet, and

wherein said control means controls a fixing condition of said fixing means.

10. An image forming apparatus according to claim 9, wherein said control means controls a fixing temperature of said fixing means.

11. An image forming apparatus according to claim 9, wherein said control means controls a fixing speed of said fixing means.

13. A detecting device according to claim 12, wherein said detecting means detects that the sheet is plain paper.

14. A detecting device according to claim 12, wherein said detecting means detects that the sheet is rough paper.

15. A detecting device according to claim 12, wherein said detecting means detects that the sheet is glossy paper.

16. A detecting device according to claim 12, wherein said reading means includes:

irradiating means for irradiating the sheet;

light receiving means for receiving a light from said irradiating means reflected back from the sheet; and

converting means for digitizing an output of said light receiving means.

17. A detecting device according to claim 16, wherein said light receiving means includes a CMOS sensor.

18. A detecting device according to claim 16, wherein said means for causing said reading means to reread the picture changes a gain of said converting means.

19. A detecting device according to claim 16, wherein said reading means includes calculating means for filter-calculating an output from said converting means, and said means for causing said reading means to reread the picture changes calculation parameters of said calculating means.

12. A detecting device comprising:

reading means for reading a picture of a surface of a feeding sheet;

discriminating means for discriminating whether a rereading is necessary or not, on the basis of the picture read by said reading means;

means for changing a reading condition of said reading means and causing said reading means to reread a picture of an edge portion of the sheet, on the basis of a fact that it has been discriminated by said discriminating means that the rereading is necessary; and

detecting means for detecting a type of the sheet on the basis of the picture read by said reading means.

20. An image forming apparatus comprising:

feeding means for feeding a sheet;

image forming means for forming an image on the sheet fed by said feeding means;

reading means for reading a picture of an edge portion of the sheet fed by said feeding means;

detecting means for detecting a thickness of the sheet on the basis of the picture read by said reading means; and

control means for controlling an image forming condition of said image forming means on the basis of a result of detection.

21. An image forming apparatus according to claim 20, wherein said detecting means detects the thickness of the sheet on the basis of the picture of a shadow of the sheet.

22. An image forming apparatus according to claim 20, wherein said reading means includes:

irradiating means for irradiating the sheet; and

light receiving means for receiving a light from said irradiating means reflected back from the sheet.

23. An image forming apparatus according to claim 22, wherein said light receiving means includes a CMOS sensor.

24. An image forming apparatus according to claim 20, wherein said image forming means includes:

transferring means for transferring a toner image to the sheet; and

fixing means for fixing the toner image transferred by said transferring means on the sheet, and

wherein said control means controls a fixing condition of said fixing means.

25. An image forming apparatus according to claim 24, wherein said control means controls a fixing temperature of said fixing means.

26. An image forming apparatus according to claim 24, wherein said control means controls a fixing speed of said fixing means.

28. A detecting device according to claim 27, wherein said detecting means detects the thickness of the sheet on the basis of the picture of a shadow of the sheet.

29. A detecting device according to claim 27, wherein said reading means includes:

irradiating means for irradiating the sheet; and

light receiving means for receiving a light from said irradiating means reflected back from the sheet.

30. A detecting device according to claim 29, wherein said light receiving means includes a CMOS sensor.

27. A detecting device comprising:

reading means for reading a picture of an edge portion of a feeding sheet; and

detecting means for detecting a thickness of the sheet on the basis of the picture read by said reading means.