A color image reading apparatus includes a plurality of line sensors which have different color filters and each of which has a plurality of light receiving elements. One of the plurality of line sensors has an opening width larger than those of the remaining line sensors. The apparatus also includes a correcting unit such as an edge emphasis circuit for correcting image signals output from the line sensors so as to obtain identical resolutions of the image signals, and a processing unit such as a masking circuit for performing color processing of the image signals corrected by the correcting unit.
This application is a continuation of application Ser. No. 08/047,353, filed Apr. 19, 1993, now abandoned, which was a continuation of application Ser. No. 07/607,702, filed Nov. 1, 1990, now abandoned, which is a division of application Ser. No. 07/253,671, filed Oct. 5, 1988, now U.S. Pat. No. 4,985,760.
Priority Data
Oct 09, 1987 [JP] 62-255069 Oct 23, 1987 [JP] 62-268847 Nov 17, 1987 [JP] 62-291593
A color-reproducing contact image sensing (CORCIS) system that eliminates the use of multiple arrays of photodetectors with separate color filters and which permits the use of any of various signal-processing improvements such as voltage pickoff, transducer gain and correlated double sample and hold processing. The device operates by sequentially illuminating the colored object to be reproduced by primary color illumination means, with each illumination transferring in parallel the appropriate color response to a readout register for sequential readout. The sample and hold, and the parallel transfer operation, allow the CORCIS system to be able to read out signal while the detector array is integrating the next color signal, thus improving the sensitivity.
This invention has as its object to provide an image reading apparatus which can prevent color mixing even when a linear image sensor in which charge transfer units are arranged to sandwich light-receiving units of different colors therebetween is used. In order to achieve the object, the image reading apparatus includes: a linear image sensor which is constituted by a plurality of image line sensors (301, 302, 303) respectively having a plurality of color filters, and transfer units (304-309) for transferring charges from the image line sensors, so that a charge obtained by a light-receiving/storage operation of at least one color image line sensor (302) is transferred to the transfer units (306, 307) via the image line sensor (303) of another color; and a subtraction circuit for subtracting a value obtained by multiplying a charge obtained by the light-receiving/storage operation of the image line sensor (303) of the other color with a correction coefficient from the charge transferred via the image line sensor (303) of the other color.
A color image reading apparatus includes a plurality of line sensors which have different color filters and each of which has a plurality of light receiving elements. One of the plurality of line sensors has an opening width larger than those of the remaining line sensors. The apparatus also includes a correcting unit such as an edge emphasis circuit for correcting image signals output from the line sensors so as to obtain identical resolutions of the image signals, and a processing unit such as a masking circuit for performing color processing of the image signals corrected by the correcting unit.
An image reading apparatus that reads color images by means of scanning the document surface with CCD sensors that correspond to red (R), green (G) and blue (B) colors respectively, comprising: a diagonal line pattern 4 provided within the CCD sensors' reading ranges; a color shift correction factor arithmetic unit 40 that detects color shifts from the data obtained by reading the diagonal line pattern and calculates correction factors; and a correction arithmetic unit 42 that corrects the document image data for each color component read in the previous step using the calculated correction factors.
A color image reading device, an output controller and a method of controlling an output from a color image reading device provide for an improved signal-noise ratio for the scanning of two-dimensional objects, as in document scanners. In the present invention, the position of a color image reading device with respect to an object to be read is oriented in order to optimize illumination in, for example, the blue wavelength. Pixel data for each line is read, generated in reverse order and/or re-phased so as to compensate for offset linear sensors on the color image reading device.
