Image inspection apparatus and image forming apparatus

Patent metadata

Field	Value
Publication number	US-2016301811-A1
Application number	US-201615091743-A
Country	US
Kind code	A1
Filing date	Apr 6, 2016
Priority date	Apr 7, 2015
Publication date	Oct 13, 2016
Grant date	—

Abstract

An image inspection apparatus includes: a light source configured to emit white light onto a test image formed on a paper sheet; an optical lens system configured to receive light reflected by the paper sheet, the reflected light being of the white light emitted from the light source; a separating unit configured to separate light having passed through the optical lens system; a reading unit configured to receive the separated light at the different wavelengths, and optically read the test image of the light; and a control unit configured to calculate edge blurs at a rising edge and a falling edge of each set of image data of the light obtained by the reading unit reading the test image, calculate widths of the test image, and determine the width calculated from the set of image data having the smallest edge blur to be the width of the test image.

First claim

What is claimed is:

1 . An image inspection apparatus comprising:
alight source configured to emit white light onto a test image formed on a paper sheet; an optical lens system configured to receive light reflected by the paper sheet, the reflected light being of the white light emitted from the light source; a separating unit configured to separate light having passed through the optical lens system in accordance with wavelength bands; a reading unit configured to receive the separated light at the different wavelengths, and optically read the test image of the light at each of the different wavelengths; and a control unit configured to calculate edge blurs at a rising edge and a falling edge of each set of image data of the light at the different wavelengths obtained by the reading unit reading the test image, calculate widths of the test image, and determine the width calculated from the set of image data having the smallest edge blur to be the width of the test image.

2 . The image inspection apparatus according to claim 1 , wherein the test image is a black image.

3 . The image inspection apparatus according to claim 1 , wherein the separating unit is a color filter capable of separating a plurality of colors from one another, the color filter being provided in front of the reading unit.

4 . An image inspection apparatus comprising:
a light source configured to emit white light onto a black test image and a color test image formed on a paper sheet; an optical lens system configured to receive light reflected by the paper sheet, the reflected light being of the white light emitted from the light source; a separating unit configured to separate light having passed through the optical lens system in accordance with wavelength bands; a reading unit configured to receive the separated light at the different wavelengths, and optically read the test images of the light at each of the different wavelengths; and a control unit configured to calculate edge blurs at a rising edge and a falling edge of each set of image data of the light at the different wavelengths obtained by the reading unit reading the black test image, calculate edge blurs at a rising edge and a falling edge of each set of image data of the light at the different wavelengths obtained by the reading unit reading the color test image, and calculate widths of the test images, wherein the control unit determines a focal length difference between a focal length of the optical lens system with respect to light at a wavelength corresponding to the image data having the smallest edge blur in the black test image and a focal length of the optical lens system with respect to light at a wavelength corresponding to a color complementary to the color test image, and correct the calculated widths of the test images by using the edge blurs and the focal length difference.

5 . The image inspection apparatus according to claim 4 , wherein the control unit obtains target widths by applying the calculated widths of the test images, the edge blurs, and the focal length difference to the following equation:
target width=calculated width+α×|focal length difference|
α: a coefficient determined by the focal length difference.

6 . The image inspection apparatus according to claim 4 , wherein the separating unit is a color filter capable of separating a plurality of colors from one another, the color filter being provided in front of the reading unit.

7 . An image forming apparatus comprising:
an image forming unit configured to form an image on a paper sheet; alight source configured to emit white light onto a test image formed on the paper sheet; an optical lens system configured to receive light reflected by the paper sheet, the reflected light being of the white light emitted from the light source; a separating unit configured to separate light having passed through the optical lens system in accordance with wavelength bands; a reading unit configured to receive the separated light at the different wavelengths, and optically read the test image of the light at each of the different wavelengths; and a control unit configured to calculate edge blurs at a rising edge and a falling edge of each set of image data of the light at the different wavelengths obtained by the reading unit reading the test image, calculate widths of the test image, and determine the width calculated from the set of image data having the smallest edge blur to be the width of the test image.

8 . An image forming apparatus comprising:
an image forming unit configured to form an image on a paper sheet; a light source configured to emit white light onto a black test image and a color test image formed on the paper sheet; an optical lens system configured to receive light reflected by the paper sheet, the reflected light being of the white light emitted from the light source; a separating unit configured to separate light having passed through the optical lens system in accordance with wavelength bands; a reading unit configured to receive the separated light at the different wavelengths, and optically read the test images of the light at each of the different wavelengths; and a control unit configured to calculate edge blurs at a rising edge and a falling edge of each set of image data of the light at the different wavelengths obtained by the reading unit reading the black test image, calculate edge blurs at a rising edge and a falling edge of each set of image data of the light at the different wavelengths obtained by the reading unit reading the color test image, and calculate widths of the test images, wherein the control unit determines a focal length difference between a focal length of the optical lens system with respect to light at a wavelength corresponding to the image data having the smallest edge blur in the black test image and a focal length of the optical lens system with respect to light at a wavelength corresponding to a color complementary to the color test image, and correct the calculated widths of the test images by using the edge blurs and the focal length difference.

Assignees

• Konica Minolta Inc

Inventors

• Yamaguchi Toru
• Kusunoki Takahiro
• Harashima Takashi

Classifications

• H04N1/605

  for controlling ink amount, strike-through, bleeding soakage or the like · CPC title

• H04N1/4092

  Edge or detail enhancement · CPC title

• H04N1/58

  Edge or detail enhancement; Noise or error suppression, e.g. colour misregistration correction (H04N1/62 takes precedence) · CPC title

• H04N1/02815

  Means for illuminating the original, not specific to a particular type of pick-up head · CPC title

• H04N1/00737

  using the scanning elements as detectors · CPC title