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US 5,854,688 AGranted
Image reading apparatus that corrects the output of light receiving element corresponding to a pixel based on output values of light receiving elements corresponding to surrounding pixels
AssigneeCanon Kabushiki Kaisha
InventorNobumasa Fukuzawa
Life of this patent
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Abstract
An original reading apparatus includes a light source for illuminating an original, and a light receiver to receive light reflected from the original, the light receiver having a plurality of light receiving elements each for outputting an electric signal in accordance with an amount of received light. Output values of the light receiving elements are corrected corresponding to pixels on the original.
Claims11
An original reading apparatus comprising:
- a light source for illuminating an original;
- a light receiving means for receiving light reflecting from the original, said light receiving means having a plurality of light receiving elements each outputting an electric signal in accordance with an amount of received light;
- and
- correction means for correcting respective output values of light receiving elements corresponding to each pixel on the original,
- wherein when the output value of a respective one of said light receiving elements corresponding to any one pixel on the original is Sxy and an output value of light receiving elements corresponding to peripheral pixels surrounding said any one pixel is S'xy, said correction means calculates a correction value CSxy in accordance with the following equation:
- ##EQU4## where, .alpha. is a constant and .SIGMA.nxy is a sum of the peripheral pixels.
3 more elements
An image forming apparatus comprising:
- a light source for illuminating an original;
- a light receiving means for receiving light reflected from the original, said light receiving means having a plurality of light receiving elements each outputting an electric signal in accordance with an amount of received light;
- correction means for correcting respective output values of light receiving elements corresponding to pixels on the original;
- and
- image forming means for forming an image on a recording material on the basis of a value corrected by said correction means;
- wherein when the output value of a respective one of said light receiving elements corresponding to any one pixel on the original is Sxy and an output value of light receiving elements corresponding to peripheral pixels surrounding said any one pixel is S'xy, said correction means calculates a correction value CSxy in accordance with the following equation:
- ##EQU5## where, .alpha. is a constant and .SIGMA.nxy is a sum of the peripheral pixels.
4 more elements
An original reading apparatus comprising:
- a light source for illuminating an original;
- a light receiving means for receiving light reflecting from the original, said light receiving means having a plurality of light receiving elements each outputting an electric signal in accordance with an amount of received light;
- and
- correction means for correcting respective output values of light receiving elements corresponding to each pixel on the original,
- wherein said correction means corrects the output value of said light receiving elements corresponding to a reading pixel of the original in accordance with an output value of light receiving elements corresponding to peripheral pixels surrounding the reading pixel.
2 more elements
Dependencies are inferred from the claim text.