Minolta Camera Kabushiki Kaisha

Minolta Company, Ltd.

Minolta Camera Co., Ltd.

Minolta Camera Kabisha Kaisha

Munehiro Nakatani

Hideo Muramatsu

Akio Nakajima

Shigenobu Fukushima

Toshio Tsuboi

Hiroyuki Suzuki

Kazuomi Sakatani

Masamichi Sugiura

Masamichi Kishi

Yoshikazu Ikenoue

Hideo Kumashiro

Hiroya Sugawa

Kanako Hamano

Nobuhiro Mishima

Nobuo Kamei

Keiji Nakatani

Hiroaki Hamano

Kazuhiro Ueda

Eiji Hanada

Hirokazu Yamada

Masanori Yamamoto

Tetsuya Itoh

Yoshiyuki Kurahashi

Takeshi Morikawa

Atsushi Ishikawa

Takeshi Minami

Hirofumi Hasegawa

Hideyuki Hashimoto

Katsuaki Tajima

Kenichi Morita

Masaaki Oyabu

Kunihiko Omura

Sou Hirota

Kazunori Shionoya

Hiroaki Hamamo

An additional data useful for the management of copies of a document for an image forming apparatus is embedded in a hard copy of the document. The additional data is embedded in an inherent image of a document as discrete dots arranged in a prescribed format. Preferably, the size of each of said discrete dots is not so large as to be recognized easily with naked eyes. The additional data can be embedded in unit of blocks. Further, the density of the discrete dots is different from the density adjacent to the discrete dots. The image data for embedding an additional data can be obtained by reading a document, or by receiving data sent from a computer or read from a floppy disk. An additional data embedded in a hard copy can be extracted from the image data on the hard copy. Further, the production of a copy according to the image data can be controlled according to the extracted additional data. For example, if the additional data means that the source of the hard copy is a secret document, the copying is allowed only for a legitimate user. An additional data is generated for each copy according to the extracted additional data for embedding it in a hard copy to identify each copy. The additional data generated for each copy are compiled and they are used to manage copies of various sources systematically and illegal copies can be traced easily. If the additional data received from a printer is not consistent with the additional data already stored, the printing may be prohibited. A transmitter for transmitting an additional data may be provided in a document such as a book.

Image forming apparatus and copy management system

Additional data useful for the management of copies of a document for an image forming apparatus is embedded in a hard copy of the document. The additional data is embedded in an image of a document as discrete dots arranged in a prescribed format. Preferably, the size of each of said discrete dots is such as not to be recognized easily with the naked eye. The image data for embedding the additional data can be obtained by reading a document, or by receiving data sent from a computer. Additional data embedded in a hard copy can be extracted from the image data on the hard copy. Further, the production of a copy according to the image data, can be controlled according to the extracted additional data. Additional data is generated for each copy according to the extracted additional data for embedding it in a hard copy to identify each copy.

A bus monitor section calculates bus-occupancy rate for each of the DMA control sections to connected to a bus in accordance with bus-use permission signals ack to ack , respectively. Furthermore, a bus-use reconcilement section changes manners of bus-use reconcilement control when the sum of a plurality of bus-occupancy rate exceeds &ldquo;50&rdquo;, a predetermined threshold. Thereby, this method avoids occurrences such that a specific device occupies the bus or vice versa, a specific device cannot get access to the bus

DMA controller with dynamically variable access priority

With facsimile apparatuses wherein color image data is coded, a facsimile on a calling side codes image data by replacing the image data with a codeword indicative of a white run-length or a black run-length, represents color information by combining specific codewords among the codewords and represents image data including color image only by codewords by combining the coded image data and the color information. A facsimile on a called side receives transmitted image data, determines color information represented by a combination of specific codewords among the codewords in the received image data, and outputs image data as specific color image when the color image is determined.

Facsimile apparatus for transmitting color image data displayed according to combination of specific codewords

A memory error detecting device for an image forming apparatus having a memory unit, a first generating means, a second generating means, a comparison means, and a memory error warning means. The first generating means generates first information related to first image data input to the memory unit. The second generating means generates second information related to second image data output from the memory unit. The comparison means compares the first information with the second information, and generates a comparison result signal. The memory error warning means signifies an error in the memory unit when the comparison result signal indicates that the first information differs from the second information.

Image forming device

An image processing apparatus capable of outputting high quality image by correcting deviations of respective positions or inclinations of a plurality of sheets of document simultaneously placed on a document base and an image forming apparatus connected to the image processing apparatus and capable of forming a copy with no inclination in respect of paper. Image data with the corrected position or corrected inclination is provided by processing the image signal.

Image processing apparatus and image forming apparatus connected to the

In data processing wherein image data are processed by dividing them into blocks, a chroma data W is obtained from the color difference data W.sub.R and W.sub.B, and the color difference data W.sub.R and W.sub.B are corrected according to an amplitude of the chroma data W. For example, if the chroma W is smaller than a prescribed threshold value, the color difference data W.sub.R and W.sub.B are set as zero. Then, the so-called block distortion can be prevented. The degree of the correction may depend on the amplitude of the chroma data W. On the other hand, DC coefficients of discrete cosine transform coefficients of adjacent blocks are compared with each other. When the DC coefficients are different from each other, block distortion occurs if they represent a same image. Then, if differences of DC coefficients of discrete cosine transform coefficients of adjacent blocks are small with each other, the DC coefficients are corrected to tend to have similar values. As to the AC coefficients, a comparator compares absolute values of AC components in the DCT coefficient data received from a discrete cosine transform section with a prescribed threshold value. Then, if absolute values of AC components in the DCT coefficient data are smaller than a prescribed threshold value, the values of the AC components are not sent to a coding section because in such cases read errors or the like are thought to affect the AC components.

Data processor

Image data of a pixel matrix are subjected to orthogonal transformation to coefficient data, which are then quantized with a first quantization table for character image and with a second quantization table for half-tone image. Image data are discriminated as character image data or half-tone image data according to the quantization data. The quantization data corresponding to the discrimination are subjected to entropy coding. Image data can be divided into first processing blocks of m*m pixel matrices and second processing blocks of M*M pixel matrices where M&gt;m. A second processing block includes one first processing block and adjacent pixels. Image data in first and second processing blocks are subjected to orthogonal transformation to coefficient data. Coefficient data of the second processing block indicates whether the image is a character image, a dot image, or a half-tone image, permitting selection of an appropriate quantization table. Image data of the first processing block is quantized according to the selected quantization table and quantized data are coded. In order to discriminate a dot image, two discrimination windows are provided, with the first consisting of coefficient data around the DC component and the second consisting of other data. Orthogonal transform coefficients of image data are calculated, and maximum absolute values in the windows are obtained. An image is discriminated to be a dot image if the first window maximum is larger than a prescribed threshold value and is larger than the second window maximum.

In a data processor, in order to perform coding efficiently, image data of a prescribed pixel matrix is subjected to orthogonal transformation to coefficient data. Obtained coefficient data is quantized with a first quantization table for character image, and they are also quantized with a second quantization table for half-tone image. Then, the image data is discriminated to be a character image data or a half-tone image data according to the two quantization data. Then, quantization data in correspondence to the discrimination is subjected to entropy coding. In a different data processor, in order to discriminate a kind of image in a processing block fast and correctly, image data are divided into first processing blocks of m*m pixel matrices and second processing blocks of M*M pixel matrices wherein M&gt;m. For example, m=8 and M=16. A second processing block includes one of first processing blocks and adjacent pixels around it. Image data in a first processing block and image dat in a second processing block including the first processing block are subjected to orthogonal transform to send coefficient data, respectively. It is discriminated according to the coefficient data of the second processing block if the image is a character image, a dot image or a half-tone image to select an appropriate quantization table. Then, image data of the first processing block is quantized according to the selected quantization table and quantized data are coded. In a further data processor, in order to discriminate a dot image in a processing block, two discrimination windows are provided, and a first of the windows consists of coefficient data around the DC component while a second consists of the other data. First, orthogonal transform coefficients of image data in a processing block are calculated, and maximum of absolute values in the two windows are obtained. An image is discriminated to be a dot image if the maximum of the first window is larger than that of the second and the former is larger than a prescribed threshold value.

An image forming apparatus records an image on a recording medium after correcting a slant of the image according to a type of document sheet or an operating history of the image forming apparatus. Normally, a slant of the document sheet is corrected by bringing one edge of the sheet in contact with a document scale provided on a document platform. When the sheet is of thin paper or sheets of different sizes are mixed, an image signal obtained by scanning a document image is electrically processed so as to correct a slant of an image to be recorded. When the image signal is electrically processed so as to correct the slant of the image to be recorded, the correction of image slant may be based also on the operating history of the image forming apparatus, for example, the total number of sheets transported, the number of times a paper jam has occurred or the cumulative value of the slant angle of the image.

Image forming apparatus

When a jam occurs in outputting an image to a printer in a facsimile apparatus, it is displayed that the printer is in a state of trouble. If the printer trouble is not solved in a prescribed time period, that one group of original being printed is stored in a compressed data memory (not shown) as a re-recording file. When the trouble is solved, the data of that one group of original stored in the re-recording file is output to the printer. As a result, a facsimile apparatus capable of clarifying the destination of the printed received image data after an interruption can be provided.

Facsimile apparatus having control means for recording a prescribed page

In a data processor, in order to discriminate the kind of image in a processing block quickly and correctly, image data is divided into first processing blocks of m*m pixel matrices and second processing blocks of M*M pixel matrices wherein M&gt;m. The second processing block includes the data of the first processing block and adjacent pixels around it. Image data in the first and second processing blocks are subjected to orthogonal transform to generate coefficient data. The image type is discriminated as a character image, a dot image or a half-tone image according to the coefficient data of the second processing block and an appropriate quantization table is then selected. Having identified the appropriate quantization table based on analysis of second processing block, image data of the first processing block is quantized according to the thus selected quantization table and quantized data is thereby coded.

The invention relates to an image reading apparatus for reading images of original documents by moving the original relative to a stationary image reader. A single image reader is used in a first embodiment. When reading the image of a first side, the single image reader is stationary at a first position to read the original. When reading the image of a second side, the single image reader is moved to a second position corresponding to the size of the original, and reads the image of the second side while said image reader is stationary at the second position. The image reading apparatus of the second embodiment uses a stationary first reader for reading a first side of an original, and a movable second image reader for reading a second side of an original. The image reading apparatus of the second embodiment changes the position of the image reader in accordance with the size of the original.

Image reading apparatus and method for reading images of different sizes

In the electronic sort of a digital copying machine, image data of a document consisting of a plurality of sheets are read and compressed to bi-level data in a memory. The compressed image data are recovered to multi-level data successively. When a plurality of copies of the document are produced, the recovery action is repeated by the number of the copies. In a facsimile machine combined with a digital copying machine, bi-level image data for the automatic reduction transmission are recovered first to multi-level image data, and the density of the multi-level image data is changed for the reduction. Then, the multi-level data are converted to bi-level data for facsimile transmission. In a digital two-color copying machine, multi-level image data of the second color of the two colors to be recorded later has to be synchronized to those of the other in correspondence to the delay of the recording time between the two colors. Then, the multi-level image data of the second color are converted to bi-level data in a delay memory in real time, and the bi-level data are read later from the delay memory and recovered to multi-level data.

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Toyohashi, Japan

Munehiro Nakatani