Color image reading apparatus and color image reading method
AssigneeRicoh Company, Ltd.
InventorNaohiro Yasuda
Life of this patent
Estimating the term…
Abstract
A color image reading apparatus reads an original image by a line sensor through sequentially lighting respective light sources of a plurality of colors with respect to a scan line. An analog-to-digital converter converts an analog image signal read by said line sensor to digital image data. A lighting frequency ratio setting part sets the lighting frequency ratio for the light sources such that not all of the light sources are equally lighted. A thinning control part performs thinning control of lighting lines according to the lighting frequency ratio at which the light sources are lighted. A read data combining part combines read data of the plurality of colors according to a predetermined combination, said read data being obtained by the thinning control.
Claims28
A color image reading apparatus reading an original image by a line sensor through sequentially lighting respective light sources of a plurality of colors with respect to a scan line, comprising:
- an analog-to-digital converter converting an analog image signal read by said line sensor to digital image data;
- a lighting frequency ratio setting part setting a lighting frequency ratio for the light sources such that not all of the light sources are equally lighted;
- a thinning control part performing thinning control of lighting lines according to the lighting frequency ratio at which the light sources are lighted;
- and
- a read data combining part combining read data of the plurality of colors according to a predetermined combination, said read data being obtained by the thinning control.
A color image reading apparatus reading an original image by a line sensor through sequentially lighting respective light sources of a plurality of colors with respect to a scan line, comprising:
- an analog-to-digital converter converting an analog image signal read by said line sensor to digital image data;
- lighting frequency ratio setting means for setting a lighting frequency ratio for the light sources such that not all of the light sources are equally lighted;
- thinning control means for performing thinning control of lighting lines according to the lighting frequency ratio at which the light sources are lighted;
- and
- read data combining means for combining read data of the plurality of colors according to a predetermined combination, said read data being obtained by the thinning control.
A method of reading an original image by a line sensor through sequentially lighting respective light sources of a plurality of colors with respect to a scan line, comprising the steps of:
- converting an analog image signal read by said line sensor to digital image data;
- setting a lighting frequency ratio for the light sources such that not all of the light sources are equally lighted;
- performing thinning control of lighting lines according to the lighting frequency ratio at which the light sources are lighted;
- and
- combining read data of the plurality of colors according to a predetermined combination, said read data being obtained by the thinning control.
A color image reading apparatus reading an original image by a line sensor through sequentially lighting respective light sources of a plurality of colors with respect to a scan line, comprising:
- an analog-to-digital converter converting an analog image signal read by said line sensor to digital image data;
- a line synchronizing pulse invalidation part invalidating a line sensor control pulse for one pulse with respect to the light source of a predetermined color;
- a lighting frequency ratio adjusting part adjusting a lighting frequency ratio of the light sources;
- a thinning control part performing thinning control of lighting lines according to the lighting frequency ratio;
- and
- a read data combining part combining read data of the plurality of colors according to a predetermined combination, said read data being obtained by the thinning control.
A color image reading apparatus reading an original image by a line sensor through sequentially lighting respective light sources of a plurality of colors with respect to a scan line, comprising:
- an analog-to-digital converter converting an analog image signal read by said line sensor to digital image data;
- line synchronizing pulse invalidation means for invalidating a line sensor control pulse for one pulse with respect to the light source of a predetermined color;
- lighting frequency ratio adjusting means for adjusting a lighting frequency ratio of the light sources;
- thinning control means for performing thinning control of lighting lines according to the lighting frequency ratio;
- and
- read data combining means for combining read data of the plurality of colors according to a predetermined combination, said read data being obtained by the thinning control.
A method of reading an original image by a line sensor through sequentially lighting respective light sources of a plurality of colors with respect to a scan line, comprising the steps of:
- converting an analog image signal read by said line sensor to digital image data;
- invalidating a line sensor control pulse for one pulse with respect to the light source of a predetermined color;
- adjusting a lighting frequency ratio of the light sources;
- performing thinning control of lighting lines according to the lighting frequency ratio;
- and
- combining read data of the plurality of colors according to a predetermined combination, said read data being obtained by the thinning control.
Dependencies are inferred from the claim text.