×

Image reading device and image forming apparatus

  • US 20020012127A1
  • Filed: 05/18/2001
  • Published: 01/31/2002
  • Est. Priority Date: 05/18/2000
  • Status: Active Grant
First Claim
Patent Images

1. An image reading device comprising:

  • a photoelectric device provided with an empty transfer part;

    an A-D converter performing A-D conversion on an output signal for each pixel of said photoelectric device;

    a reference voltage varying part varying a reference voltage of said A-D converter;

    a detecting part detecting a black correction reference data from output for each pixel of said photoelectric device;

    a black shading correcting part subtracting the black correction reference data from digital image data obtained from the output signal for each pixel of said photoelectric device when an image is read, through said A-D converter having the reference voltage set therein; and

    a correcting part correcting the black correction reference data by a ratio between an output level of said empty transfer part obtained through said A-D converter when the black correction reference data is detected and an output level of said empty transfer part obtained through said A-D converter when the image is read.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×