Abstract: An original image comprises a printed region on which a predetermined printed matter is realized and a background region on which no printed matter is realized. The shape of a peripheral zone in the original image comprises the shape of the background region, which shape exists particularly at the peripheral region of said original image. It is determined whether or not the original image comprises the special document by detecting the peripheral zone. Further, the original image has an outer-frame region, having a predetermined shape at the peripheral region of the original image. The determination is carried out using a result of measuring the width of the outer-frame region. Further, the width of the outer-frame region comprises a width along a direction substantially perpendicular to a direction extending along the outline of the original image.

Abstract: In a case where facsimile communications are executed via a communication line according to a specified communication protocol, in a machine in the receiving side, expanded functional information indicating the receiving form of the machine is stored in an expanded functional information memory, the expanded functional information stored in the expanded functional memory is returned by a control section to a machine in the transmitting side according to a request from the machine in the transmitting side, and then a facsimile message is received in the receiving form according to the expanded functional information notified from the machine in the transmitting side after a response is returned for controlling an output operation of a color printer.

Abstract: An original image comprises a printed region on which a predetermined printed matter is realized and a background region on which no printed matter is realized. The shape of a peripheral zone in the original image comprises the shape of the background region, which shape exists particularly at the peripheral region of said original image. It is determined whether or not the original image comprises the special document by detecting the peripheral zone. Further, the original image has an outer-frame region, having a predetermined shape, at the peripheral region of the original image. The determination is carried out using a result of measuring the width of the outer-frame region. Further, the width of the outer-frame region comprises a width along a direction substantially perpendicular to a direction extending along the outline of the original image.

Abstract: An image density control method applicable to an electrophotographic copier or similar image recorder for controlling the toner concentration of a two-component developer, i.e., a mixture of toner and carrier to maintain the density of a toner image produced by the developer constant. Predetermined calculations are performed on the basis of the output of a photosensor which is responsive to the toner images representative of reference patterns formed on a photoconductive element.

Abstract: An image density control method applicable to an electrophotographic copier or similar image recorder for controlling the toner concentration of a two-component developer, i.e., a mixture of toner and carrier to maintain the density of a toner image produced by the developer constant. Predetermined calculations are performed on the basis of the output of a photosensor which is responsive to the toner images representative of reference patterns formed on a photoconductive element.

Abstract: An image forming apparatus including an image reading unit for reading an original and for outputting image data corresponding to the original, an image processing unit for processing the image data supplied from the image reading unit in accordance with a predetermined method and for outputting printing image data, a printer unit for printing an image corresponding to the printing image data supplied from the image processing unit, and an image adding unit for adding an identification information to the recording sheet on which the image is formed by the printer unit, the identification information identifying the image forming apparatus in order to prevent forgery of securities, confidential documents or backnotes. A detector detects the presence or absence of the image adding unit and disables the copying functions when the image adding unit is absent.

Abstract: An image density control method applicable to an electrophotographic copier or similar image recorder for controlling the toner concentration of a two-component developer, i.e., a mixture of toner and carrier to maintain the density of a toner image produced by the developer constant. Predetermined calculations are performed on the basis of the output of a photosensor which is responsive to the toner images representative of reference patterns formed on a photoconductive element.

Abstract: A color image processing apparatus for automatically feeding a plurality of documents one at a time and processing images printed on the documents. The apparatus automatically discriminates an image as to chromatic/achromatic without errors and thereby executes optimal image processing matching the kind of an image without resorting to operator's manipulations.

Abstract: A digital color converting apparatus applicable to a color copier and others for converting only a desired color included in a color image into another desired color. One of a plurality of input image signals which has the highest level is identified to determine a color to be rendered by the instantaneous signals and, then, whether the result of the identification and a color specified are coincident is determined. Hence, color conversion is effected only in those regions in which the image is regarded as being of the color specified. For color conversion, the input image signal associated with an original color to be changed is applied to an output terminal which is assigned to an alternative color while, at the same time, the input image signal associated with the alternative color is applied to an output terminal which is assigned to the original color, i.e., signals individually associated with the original and alternative colors are replaced with each other.

Abstract: A color image generating apparatus has a memory circuit for memorizing at least a part of an original image in a test print mode operation of the apparatus. An output circuit is used for reading the memorized image from the memory circuit and repeatedly outputting this image, a plurality of times on one display. Image processing circuit for processing the image with a different print condition at each time of repeatedly outputting the image from the output circuitry is used. A plurality of sample images are each printed in a different print condition and displayed on one test sample print paper so that an optimal desired image is selected from the plurality of test sample images.

Abstract: A printer structure relies on a laser modulator operating in response to image data cooperates with a rotary deflector for deflecting the modulated laser onto a recording medium with the rotation of the rotary deflector being controlled by a predetermined signal. A synchronizer receives the deflected laser irradiated from the rotary deflector in the vicinity of the recording medium and the synchronizer outputs a signal which defines a timing which the laser modulator uses to begin modulation. At least three memories are used which are each capable of storing the image data corresponding to one line defined by one deflection of the rotary deflector and a memory control device controls the writing of the image data inputted from an exterior of the printer in one memory means after switching the one memory to a write operation in synchronization with the rotary signal defining the one line.

Abstract: Processing used to represent a gradation by changing the number of black pixels and the number of white pixels in a matrix of 8.times.8 pixels. First, edge information sampled from the input data is allocated to corresponding pixel positions of the output data with priority. A residual gradation value is determined by subtracting a value corresponding to the edge information already allocated from the average gradation of the input data, and black pixels and white pixels are alternately allocated to the remaining pixel positions of the output data except for the edge region, in accordance with the ratio of the number of those remaining pixels to the residual gradation value.

Abstract: A recording image density control method for electrophotography comprising the steps of forming at least two latent electrostatic image patterns with different electric potentials on the surface of a photoconductor; developing the latent electrostatic images patterns to toner image patterns by use of toner contained in the developer; detecting data relevant to image density for each developed toner image pattern (such as the image density of each developed toner image pattern, for instance, by a toner image pattern, for instance, by a photosensor), with a different resolution for each image pattern; determining the ratio of the data for one image pattern to the data for the other image pattern by A/D conversion; and controlling at least one recording image density controlling parameter, such as the amount of the toner supplied to a development apparatus, in accordance with the ratio for controlling recording image density, whereby recording image density can be controlled.

Abstract: An image density control method for electrophotography which controls at least one of various image density parameters in response to values detected from different pattern areas. The image density parameters include an amount of charge deposited on a photoconductive element by a charger, bias voltage for development, toner density in a developer, amount of toner supply to a developing unit and transfer potential. At least two pattern areas having different potentials are formed on the surface of the photoconductive element by at least one of various means for forming charge patterns which include controlling the energization of the charger, controlling an illuminating lamp and projecting an image pattern.

Abstract: An image density control method for an electrophotographic apparatus is disclosed which prepares a white pattern region and a black pattern region on a photoconductive element whose electrostatic latent images are far different from each other in potential. Values relating to image densities individually associated with the two pattern regions are sensed and, based on the sensed values, parameters relating to image processing which effect image density are controlled. When any of the sensed values does not lie in a predetermined range, it is suitably compensated.

Abstract: A method of controlling an image density in electrophotography by controlling at least one of various image density parameters in response to values detected from different pattern areas, the image density parameters including an amount of charge deposited on a photoconductive element by a charger, bias voltage for development, toner concentration in a developer, amount of toner supply to a developing unit and image transfer potential. The method forms at least two pattern areas having different potentials on the surface of the photoconductive element by at least one of various means for forming charge patterns which include controlling the energization of the charger, controlling an illumination lamp and projecting an image pattern.

Abstract: An automatic control system for an offset printing machine includes a process execution instructions generating circuit having latched therein instructions for executing various operation processes and adapted to shift from one operation phase to another for successively generating process execution instructions, so that an ink forming and master plate feeding process, an inking process, a transfer-printing process, a printing process, and a master plate ejecting and cleaning process can be automatically executed in correct order. The number of times for executing each of the etching, inking, transfer-printing and cleaning processes can be adjusted in a process setting structure. When a master plate feeding error detecting signal is generated, the process execution instructions generating circuit is reset to an initial condition of stop instructions which prevailed prior to actuation of a start switch.