Abstract: The present printing system comprises a host computer (1)that orders scanners (2), digital cameras (3) and printers (4) to execute image processing, the host computer (1) setting up items of image processing to be performed by the printer (4) depending on the model of scanner (2) or digital camera (3) being used. The host computer (1) can set up the most suitable image processing items according to what kind of scanner (2) or digital camera (3) is used. Of the scanner (2), digital camera (3) and printer (4), the device having better processing ability can be assigned to more processes so that the time required for printing is shortened efficiently.

Abstract: The present printing system comprises a host computer 1 that orders scanners 2, digital cameras 3 and printers 4 to execute image processing, the host computer 1 setting up items of image processing to be performed by the printer 4 depending on the model of scanner 2 or digital camera 3 being used. The host computer 1 can set up the most suitable image processing items according to what kind of scanner 2 or digital camera 3 is used. Of the scanner 2, digital camera 3 and printer 4, the device having better processing ability can be assigned to more processes so that the time required for printing is shortened efficiently.

Abstract: A copying apparatus includes a copying machine unit, an operation portion having a central processing unit and an image processing unit having a central processing unit. A workstation is connected to the operation portion through the image processing unit. Data communication is performed between the workstation and the image processing unit and between the image processing unit and the operation portion. The image formation processing performed by the copying machine unit is controlled based on a command generated by operating the workstation.

Abstract: An image forming apparatus is provided with a zoom processing circuit, a scanning optical system and an enlarging/reducing circuit. The enlargement/reduction of the formed image in the main scanning direction is performed by the zoom processing circuit and an enlarging/reducing circuit, and the enlargement/reduction in the sub scanning direction is performed by the scanning speed of the scanning optical system and the enlarging/reducing circuit. When a magnification within a magnification range depending on the zoom processing circuit and the scanning optical system is specified, the enlargement/reduction of the input image data by the enlarging/reducing circuit is not performed.

Abstract: In a gradation output adjusting method according to the present invention, a gradation correcting section 64 corrects a gradation value of input data in accordance with a predetermined gradation correcting curve and applies the data after the correction to a printer output section 66. In preparing a gradation correcting curve, test data for forming a gradation scale is inputted to the printer output section 66 from a CPU 70. An image corresponding to the test data is read by a scanner section 1. A proper gradation value to be applied to the printer output section 66 is found with respect to some gradation values of the input data on the basis of the result of the reading. A pre-gradation correcting curve is prepared on the basis of the proper gradation value. The pre-gradation correcting curve and a plurality of types of curve patterns previously stored in a ROM 72 are matched. A curve pattern which is best matched to the pre-gradation correcting curve is set as a detailed gradation correcting curve.

Abstract: An electrographic copying machine in which an image projected on an original glass stand by a film projector is read out by a scanner and copied is provided with a color scanner including a CCD for reading out a projected image, a smoothing processing unit for averaging the tone data of pixels outputted from the color scanner every four pixels, a difference value totaling unit for totaling the difference values between the averaged tone data, and a control unit for performing focusing of the film projector so that the total of the difference values is maximum. The focusing of the projected image is automatically performed.

Abstract: The average value of each of yellow, magenta and cyan color image data of a color-to-be-converted which data are obtained at the time of pre-scanning of a copying machine and stored in memories, respectively, is calculated, and then, predetermined set values are respectively added to and subtracted from the calculated average values of yellow, magenta and cyan to obtain upper and lower limit values of the conversion range. When the lower limit value obtained by subtraction is below a predetermined lower limit restriction value, the lower limit restriction value is set as the lower limit value of the conversion range. With this feature, when an extremely pale color is specified as a color-to-be-converted in a region other than a background portion of a color original where no letters, etc. are printed, the color of the background portion is not converted together with the specified color.

Abstract: In a color correcting method for use in a color image forming apparatus, color image data are calculated and then corrected by solving a masking equation by allotting the tone number of input image data according to the value of each coefficient of reflection density of each of three primary colors in the masking equation.

Abstract: This invention relates to a color image forming apparatus which is capable of forming a mono-color image based on the color image input data. The apparatus includes a circuit for determining the highest value of the image input data. This circuit is called the highest value image data outputting circuit. The highest input color data value is found by comparing the values of the image data for the three primary colors (yellow, magenta and cyan) and outputting the value for the color having the highest input value. The apparatus further includes a mono-color image forming portion which forms a mono-colored image based on the output of the highest value image data outputting circuit.

Abstract: An interface system for a copying system, wherein a frame of transmission data employing a serial communication between a copying machine main body and peripheral devices thereof comprises an address block, a data block and a checksum data block, an optional device corresponding to an address transmitted from the main body transfers data to the main body when the data received coincides with checksum data obtained in the device based on the received data and the transfer of the data is complete when the main body confirms that the transmission address coincides with the transferred data, and when the transferred data is not returned from the optional device or the coincidence is not confirmed, it is determined that a transmission error occurs and data is transmitted from the main body again, whereby reliability of transmission is improved.

Abstract: A photoconductive drum device for electrostatic copying machines or the like includes a temperature maintaining heater bent to a cylindrical form and accommodated in the main body of a photoconductive drum. The heater is constructed with a base plate and a heat generator attached to the base plate. The base plate has a parallelogrammatic form substantially corresponding to a shape which is obtained by cutting a hollow cylinder, having a diameter approximate to the inside diameter of the drum main body, along a helical cut line and unbending the cylinder.

Abstract: An automatic document feeder, comprising a document supply section for supplying documents one by one toward a document platen, a belt feed section for transferring a supplied document to a predetermined position on the document platen to enable an image forming operation, and a document discharge section for discharging onto a document discharge tray a document fed from the belt feed section upon completion of the image forming operation, is attached so that it is upwardly turnable with respect to the document platen so as to enable manual and automatic document settings to be made selectively. Further, the automatic document feeder is designed to discriminate between manual and automatic document setting modes and to detect the presence or absence of a document at a predetermined position in the automatic document feeder when the automatic document setting mode is selected. The automatic document feeder is driven with a predetermined timing for the setting of documents.