Abstract: An image of stabilized tint is output even if a supplied transfer medium is changed to a transfer medium of a different surface gloss or type of paper. If the supplied transfer medium has changed, the tint of a corrective image formed on the transfer medium is sensed, a tint correction of an image forming portion is performed based upon result of sensing, and corrective data of the tint correction and information relating to the transfer medium is stored. If a change of the transfer medium is sensed subsequently, a determination is made as to whether the transfer medium is substantially the same transfer medium, based upon the stored information relating to the transfer medium. If the transfer medium is substantially the same, then image processing is executed based upon the stored corrective data.

Abstract: A color image forming apparatus, when a white LED is made to emit light onto a color image so that the reflected light can be detected, changes a color measuring condition in adaptation to a reflectance predicted for the image from the forming condition of the color image to be detected. The amount of reflected light is detected by photodiodes, and the image forming condition is adjusted, based on the detected amount of reflected light of each color image. Thereby, irrespective of the reflectance of each color image, the color measurement of each color image is effected with good accuracy, and the hue and density of the color image to be detected are accurately detected, thereby to form a color image with excellent color reproduction.

Abstract: An image forming apparatus has an image forming unit for forming an image on a recording medium; a conveying unit having a conveying part for conveying the recording medium while contacting the recording medium; a detection unit for detecting the chromaticity or the density of the image formed on the recording medium; and a control unit for controlling the image forming unit based on the chromaticity or the density of the image detected by the detection unit. The image forming unit forms an image for which the chromaticity or the density is to be detected at a predetermined position on the recording medium whereat the recording medium does not contact the conveying parts of the conveying unit. With this configuration, an image having a stable quality can be formed.

Abstract: An image forming apparatus is provided in which, by detecting an image formed on a recording medium, at least one of the density and chromaticity of the image can be properly controlled. The image forming apparatus includes an image forming unit for forming a toner image on an image carrier, a transfer unit for transferring the toner image formed by the image forming unit onto a transfer material in a transfer position, a fusing unit for fusing the toner image transferred by the transfer unit on the transfer material, a feed-direction changing unit for changing over a feed direction of the transfer material so that the transfer material having the toner image fused by the fusing unit is reversed and fed to the transfer position, a detecting unit for detecting, in a predetermined detecting position, the toner image fused on the transfer material by the fusing unit, and a control unit for controlling the image forming unit based on result detected by the detecting unit.

Abstract: Disclosed are a shading correction method for a sensor capable of accurately detecting color tint of a toner patch without using any white-color reference to execute shading correction in the sensor, a shading correction apparatus for a sensor, and a color image forming apparatus. In the shading correction, light reflected by a rich K toner patch formed on a transferring material is detected, a shading correction value for the sensor is calculated based on detected data, and correction is executed using the shading correction value during operation for detecting a toner patch for color stabilization.

Abstract: An image of stabilized tint is output even if a supplied transfer medium is changed to a transfer medium of a different surface gloss or type of paper. If the supplied transfer medium has changed, the tint of a corrective image formed on the transfer medium is sensed, a tint correction of image forming means is performed based upon result of sensing, and corrective data of the tint correction and information relating to the transfer medium is stored (S209 to S217). If a change of the transfer medium is sensed subsequently (“NO” at S204), whether the transfer medium is substantially the same transfer medium is determined based upon the stored information relating to the transfer medium (S214). If the transfer medium is substantially the same, then image processing is executed based upon the stored corrective data (S216, S205 to S207).

Abstract: A color image forming apparatus, when a white LED is made to emit light to thereby detect reflected light from a color image, changes a color measuring condition in adaptation to a reflectance predicted from the forming condition of the color image to be detected and detects the amount of reflected light by photodiodes (R,G,B), and adjusts the image forming condition from the detected amount of reflected light of each color image. Thereby, irrespective of the reflectance of each color image, the color measurement of each color image is effected with good accuracy, and the hue and density of the color image to be detected are accurately detected to thereby form a color image excellent in color reproducibility.

Abstract: There is provided an image forming apparatus having good color reproductivity as well as a toner patch detection method, in which reflected light from a toner patch can be detected with a good S/N ratio based on a small quantity of light, and the color tint and density of the toner patch can be detected under limited time and a limited length of an intermediate transfer member or transfer material, without wasting the toner. A detecting operation of an accumulation type sensor for detecting a toner patch to be used for controlling at least one of density, tone reproduction and color tint of a toner image formed on a transfer material is controlled in accordance with a timing of detection by a synchronization circuit, of a toner patch for position detection formed on the transfer material.

Abstract: Disclosed are a shading correction method for a sensor capable of accurately detecting color tint of a toner patch without using any white-color reference to execute shading correction in the sensor, a shading correction apparatus for a sensor, and a color image forming apparatus. In the shading correction, light reflected by a rich K toner patch formed on a transferring material is detected, a shading correction value for the sensor is calculated based on detected data, and correction is executed using the shading correction value during operation for detecting a toner patch for color stabilization.

Abstract: In an image forming apparatus of the tandem type, nonvolatile memories are carried on a plurality of interchangeable units to thereby realize a radio frequency memory system unrelated to the reliability of contact of a connector. By an analog switch low in rated voltage provided at the front stage of an amplification circuit, the transmission signal of a communication IC is changed over to a plurality of transmitting circuits having their outputs individually adjustable, and the reception signal of an antenna part is changed over by the analog switch, and receiving circuits are provided at the rear stage of the analog switch and made common by a circuit.

Abstract: An image forming apparatus is provided in which, by detecting an image formed on a recording medium, at least one of the density and chromaticity of the image can be properly controlled. The image forming apparatus comprises an image forming unit for forming a toner image on an image carrier, a transfer unit for transferring the toner image formed by the image forming unit onto a transfer material in a transfer position, a fusing unit for fusing the toner image transferred by the transfer unit on the transfer material, a feed-direction changing unit for changing over a feed direction of the transfer material so that the transfer material having the toner image fused by the fusing unit is reversed and fed to the transfer position, a detecting unit for detecting, in a predetermined detecting position, the toner image fused on the transfer material by the fusing unit, and a control unit for controlling the image forming unit based on a result detected by the detecting unit.

Abstract: An image forming apparatus has an image forming unit for forming an image on a recording medium; a conveying unit having a conveying part for conveying the recording medium while contacting the recording medium; a detection unit for detecting the chromaticity or the density of the image formed on the recording medium; and a control unit for controlling the image forming unit based on the chromaticity or the density of the image detected by the detection unit. The image forming unit forms an image for which the chromaticity or the density is to be detected at a predetermined position on the recording medium whereat the recording medium does not contact the conveying parts of the conveying unit. With this configuration, an image having a stable quality can be formed.

Abstract: There is provided an image forming apparatus having good color reproductivity as well as a toner patch detection method, in which reflected light from a toner patch can be detected with a good S/N ratio based on a small quantity of light, and the color tint and density of the toner patch can be detected under limited time and a limited length of an intermediate transfer member or transfer material, without wasting the toner. A detecting operation of an accumulation type sensor for detecting a toner patch to be used for controlling at least one of density, tone reproduction and color tint of a toner image formed on a transfer material is controlled in accordance with a timing of detection by a synchronization circuit, of a toner patch for position detection formed on the transfer material.

Abstract: In order to prevent variations in a power-supply voltage caused by a parasitic inductance, a series circuit including at least one resistance and at least one capacitance is provided adjacent to a switching circuit, between a high-voltage-side interconnection and a low-voltage-side interconnection of the power-supply voltage for the switching circuit.

Abstract: In an image forming apparatus of the tandem type, nonvolatile memories are carried on a plurality of interchangeable units to thereby realize a radio frequency memory system unrelated to the reliability of contact of a connector. By an analog switch low in rated voltage provided at the front stage of an amplification circuit, the transmission signal of a communication IC is changed over to a plurality of transmitting circuits having their outputs individually adjustable, and the reception signal of an antenna part is changed over by the analog switch, and receiving circuits are provided at the rear stage of the analog switch and made common by a circuit.

Abstract: A light emitting element drive apparatus includes a differential signal processing circuit for performing logic processing of input complementary image signals that are 180.degree. out of phase and at least one control signal using a differential circuit while maintaining the complementarity of signals to generate complementary output signals, and a switching circuit which is driven by the complementary output signals to supply a drive current to a light emitting element.

Abstract: This invention relates to a focus detecting apparatus using an area sensor as an AF sensor, and particularly provides a focus detecting apparatus in which when any area in a scene is designated and the focus state in that area is to be detected, the output from an area on the sensor corresponding to the designated area of the scene is read and processed on the basis of the information of an area on the area sensor corresponding to the designated area of the scene pre-memorized in a memory circuit.

Abstract: This invention relates to a focus detecting apparatus using an area sensor as an AF sensor, and particularly provides a focus detecting apparatus in which when any area in a scene is designated and the focus state in that area is to be detected, the output from an area on the sensor corresponding to the designated area of the scene is read and processed on the basis of the information of an area on the area sensor corresponding to the designated area of the scene pre-memorized in a memory circuit.

Abstract: A photoelectric converter has photodetectors having plural arrays wherein plural photoreceiving elements are arranged for detecting incident light. The converter has a reading circuit for reading an output signal from the photodetector, the reading circuit having a detection circuit for detecting maximum and minimum signals from the plural photoreceiving elements of the photodetector. The photoelectric converter has at least three arrays arranged parallel to each other or substantially parallel to each other, and at least one array is arranged in a direction perpendicular to the at least three arrays. The reading circuit is arranged adjacent to the plural arrays, and the photodetectors and the reading circuit are provided on a common substrate.

Abstract: An image of stabilized tint is output even if a supplied transfer medium is changed to a transfer medium of a different surface gloss or type of paper. If the supplied transfer medium has changed, the tint of a corrective image formed on the transfer medium is sensed, a tint correction of an image forming portion is performed based upon result of sensing, and corrective data of the tint correction and information relating to the transfer medium is stored. If a change of the transfer medium is sensed subsequently, a determination is made as to whether the transfer medium is substantially the same transfer medium, based upon the stored information relating to the transfer medium. If the transfer medium is substantially the same, then image processing is executed based upon the stored corrective data.