Abstract: An image reading apparatus includes an original placing platen formed of a rectangular transparent member on which an original is placed; a photoelectrical conversion device for reading an image of the original-placed on the transparent member; an original pressing plate having an original pressing surface for pressing the overall surface of the original placing platen, the original pressing surface having a first area formed at a portion opposing a first side of the transparent member and a second area formed at a portion opposing a second side crossing at a right angle to the first side of the transparent member. The first and second areas are determined as a predetermined color by the photoelectrical conversion device.

Abstract: An image processing apparatus reading images by relatively moving linear CCDs in a subscanning direction on the original images includes a clock generation circuit for generating first and second clock signals having different pulse numbers per unit time, and first and second image memories alternately writing line by line the read image data, one of which carries out writing operation while the other carries out reading operation of the written image data. Writing address of the first and second image memory is designated by a first clock signal, and a reading address of the first and second image memory is designated by a second clock signal. When the image data is stored with low frequency clock signal and the image data are read in accordance with a high frequency clock signal, a reduced image can be formed.

Abstract: An image reading apparatus according to the present invention includes: an image reading apparatus including a plurality of image reading elements; a reference image reading apparatus for reading a reference image by using the image reading apparatus; a smoothing apparatus for smoothing reference image data read by the reference image reading apparatus; an original image reading apparatus for reading an original image by using the image reading apparatus; and an original data correcting apparatus for correcting original data read by the original image reading apparatus on the basis of the smoothed reference image data.

Abstract: An image processing apparatus for converting multi-tone image signals to binary image signals in reference to threshold levels arranged in matrix to form a threshold pattern, which apparatus comprises a generator for generating the multi-tone image signals, a first memory storing a plurality of threshold patterns which are different from each other, a selector for selecting one of the threshold patterns, a high-speed memory for storing the threshold patterns selected by the selector from first memory, a writing unit for writing the selected thereshold pattern in the high-speed memory from the first memory, a reading unit for reading out the selected threshold pattern from the high-speed memory, and a converter for converting the multi-tone image signals generated by the generator to the binary image signals in reference to the threshold levels of the selected threshold pattern which are read out from the high-speed memory by the reading unit.

Abstract: A digital color copying machine comprising a memory for storing a multi-level image signal or a binary image signal is disclosed. In a superimpose mode of the copying machine, after an image signal of a first document image stored in the memory is read out, the first document image is superimposed on a second document image on a copying paper.

Abstract: An image processing apparatus reads an original image by dividing it into pixels, processes respective image data obtained by the reading, and outputs an image signal corresponding to each pixel. The apparatus includes a selector for selecting minimum image data from image data of additive three primary colors obtained by reading a color image; a multiplying device for multiplying the minimum image data by either an under-color removal coefficient data or a black paint coefficient data supplied thereto and outputting under-color image data or black paint image data. An under-color removal calculator receives the image data of the additive three primary colors and the image data outputted from the multiplying device and generates under-color removal image data corresponding to the image data of the respective additive colors based on the under-color image data.

Abstract: A color image read apparatus which makes efficient color balance correction and shading correction by a simple configuration in a manner that color balance correction of image signals of plural colors of a color image sensor using optoelectric transducers is made in A/D conversion on the basis of a reference voltage for each color, and shading correction thereof is made on the basis of one reference data obtained from image signals of plural colors of a reference white pattern read prior to an original.

Abstract: An image processing device for reading an original image by shifting in a sub-scanning direction image sensors provided in a main scanning direction to serially output image signals read, includes line memories for storing image signals by a plurality of lines in the sub-scanning direction, read for every line by the image sensors, an output device for outputting in parallel the image signals from the line memories, and an edge emphasizing device for carrying out edge emphasis in accordance with the image signals outputted by the output device in response to signals externally applied.

Abstract: An image forming device which can form an image by printing a plurality of dots based on an image information that contains a plurality of density data corresponding to a plurality of pixels defined by the fractionalization of the original image, and which can express the density of an image by controlling the number of dots to be printed within a predetermined tone unit area. The image forming device includes a threshold pattern generator for generating a threshold pattern which is a repetition of a basic pattern including a predetermined number "L" of thresholds, a comparator for comparing respective density data with a predetermined number "M" of thresholds selected from all "L" of the thresholds in which "L" is not an integer multiple of "M", and for producing a predetermined number "M" of print data corresponding to the respective density data; and a printer for printing on a printing sheet dots corresponding to the "M" print data in a line along a main scanning direction.

Abstract: An image reading apparatus having a line image sensor for line scanning a document. The line image sensor includes plural sensor chips aligned in a main scan direction for outputting image signals. Plural analogue to digital converters convert analogue image signals output from respective image sensor chips into digital form. Plural FIFO memories store the digitalized image data. The digitalized image data obtained from each of the sensor chips is written in parallel into the corresponding memory. The digitalized image data is output serially in the order of alignment of the sensor chips.

Abstract: An image reading apparatus having a line image sensor for line scanning a document is disclosed. The line image sensor is comprised of plural sensor chips aligned in the main scan direction thereof each of which has an output terminal for outputting each image signal obtained thereby. The image reading apparatus provides plural analogue to digital conversion means for converting respective analogue image signals outputted from respective image sensor chips into digital data, respectively, plural memory means for memorizing the digital data and an output means for reading said digital data from said plural memory means parallel and for outputting those digital data having been read serially.

Abstract: An image reading apparatus in accordance with the present invention reads a color image to separate the image into three primary colors by an image sensor and outputs image data corresponding to each of the colors. This image reading apparatus comprises a scanning device for making the image sensor relatively scan for a reference chart and an original, an A/D converter for converting an output of the image sensor into digital data corresponding to each of the primary colors, an operation device for evaluating correction data of each color from the output of the image sensor generated when the image sensor scans the reference chart, a multiplier for multiplying the digital data of each color by the correction data evaluated, an adder for adding a result of the multiplication and digital data before being multiplied, a shading correction circuit provided at a succeeding stage of the adder, and a line memory provided at a succeeding stage of the shading correction circuit.

Abstract: A color image read apparatus which makes efficient color balance correction and shading correction by a simple configuration in a manner that color balance correction of image signals of plural colors of a color image sensor using optoelectric transducers is made in A/D conversion on the basis of a reference voltage for each color, and shading correction thereof is made on the basis of one reference data obtained from image signals of plural colors of a reference white pattern read prior to an original.

Abstract: A color image reading apparatus according to the present invention processes by shifting of a sensor element one by one, output signals from three sensor elements consisting of each one picture element of a one-dimensional image sensor sensing one of three primary colors respectively. The sensor elements read any image so that printing data can be increased apparently up to three times of the picture element density of the sensor. A circuit is provided for thinning out the printing data for assuring adaptability to various printers.