Riso Kagaku Corporation

Shinya Okada

Yoshiyuki Okada

Yukio Irie

Aya Nakadai

A light emitting sensor emits light toward sheets carried along a carriage path and the quantity of light transmitted through each to the sheets is detected by a light receiving sensor. A predetermined number of samples of light quantities received by the light receiving sensor are sampled for each of a plurality of sampling ranges. A multiple feed for each sample range is detected based on light quantity data sampled for each sampling range. A decision of the multiple feed of the sheets is performed based on a plurality of results of the detection of the multiple feed for the plurality of sampling ranges.

Method and device for detecting multiple feed

A light emitting sensor emits light toward sheets carried along a carriage path and the quantity of light transmitted through each to the sheets is detected by a light receiving sensor. A predetermined sampling number of electric signals indicative of light quantity detected by the light receiving sensor is stored in a memory. A histogram of the light quantities stored in the memory is created. A light quantity corresponding to a maximum frequency for an underlying portion of the sheets is detected based on the created histogram. A multiple feed of the sheets is detected based on a variation in the light quantity of the maximum frequency for the underlying portion.

An operator can select image processing for a half tone image area among a plurality of processing methods, and image processing appropriate for the image can be carried out thereby. An original image is read by an image sensor and output through either simple binary conversion by binary conversion means for character processing or half tone image processing by binary conversion means for photograph processing. Judging means judges whether image data are of a character image area or a half tone image area, and switches output between the binary conversion means for character processing and the binary conversion means for photograph processing. The binary conversion means for photograph processing includes error diffusion processing means and dither processing means . By setting of setting means carried out by an operator, output from either the error diffusion processing means or the dither processing means is selected for a half tone image.

Image processing apparatus

Image data for a margin around the image area of a book form original can be erased and image data for a book center portion are obtained without loss. In a photograph mode, a low threshold value is set in first binary conversion means , and image data having been input are binary converted by using this value. Based on the image data having been converted, a first coercion signal generating unit judges a margin around the original image. A high threshold value is set to second binary conversion means and image data having been input are binary converted by using this value. Based on the image data having been converted, a second coercion signal generating unit judges a margin around the original and a portion including a book center portion. A character processing binary conversion unit carries out binary conversion on input image data for the portion within the original, and outputs whitening data which erase the margin around the original. A photograph processing binary conversion unit carries out tone image binary conversion only on the book center portion in the input image data and outputs the data thereof. An image processing selecting unit makes the image data for the portion within the original image selectively output from the character processing binary conversion unit and makes the image data for the book center portion selectively output from the photograph processing binary conversion unit

Growing community of inventors

Ibaraki-ken, Japan

Shinya Okada