Abstract: An image forming apparatus having a color mode and a monochromatic mode, which includes: a transmission member, which can be switched between a transmitted state where a motor transfers a drive force to a single photoreceptor drum and a non-transmitted state where the motor does not transfer the drive force to the single photoreceptor drum; and a controller which switches to the non-transmitted state while executing an image formation in the monochromatic mode, and when a command to execute a next image formation is not instructed, switches to the transmitted state after a phase adjustment of each photoreceptor drum after the image formation in the monochromatic mode, and controls the motor to execute a slight rotation operation at every prescribed period of time by synchronizing plural drums including the single photoreceptor drum with each other through the transmission member.

Abstract: A color image forming apparatus including: an image forming section which forms an image based on image information on an image carrier provided in the image forming section; a detection section which detects a print mark for color misalignment correction formed on the image carrier by the image forming section, and outputs print mark detection information; and a control section for executing color misalignment correction control based on the print mark detection information outputted from the detection section, wherein, the control section obtains a trend of a color misalignment amount of the print mark by statistically processing data of the result of the print mark detection, calculates an execution timing of color misalignment correction base on the obtained trend, and executes the color misalignment correction at the calculated execution timing.

Abstract: In an image forming apparatus for forming a color image by superposing component color images, a control device obtains position data representing a forming position of each of plural registration mark images for the component color images with respect to a positional reference value arbitrarily determined, divides the position data into each of a unit reference range representing a range in which one mark image is formed, converts the position data divided for each unit reference range into those based on respective reference values representing the front edge of the unit reference ranges, extracts the position data representing ranges common to the mutually overlapping ranges each of which is represented by a couple of position data corresponding to the rising and falling edges of a passage timing pulse as read position data of the mark image of the component color, and calculates the amounts of positional deviations of the component color images from one another on the basis of the position data extracted.

Abstract: Present invention uses the main power source and auxiliary power source to supply power to a load, makes them take partial charge of power supply, and when the load current reaches its peak, detects a current and a voltage generated by the auxiliary power source, and when the detected values are larger than set values or lower than the set values, controls the output current of the main power source.

Abstract: In an image forming apparatus for forming a color image by superposing component color images, a control device obtains position data representing a forming position of each of plural registration mark images for the component color images with respect to a positional reference value arbitrarily determined, divides the position data into each of a unit reference range representing a range in which one mark image is formed, converts the position data divided for each unit reference range into those based on respective reference values representing the front edge of the unit reference ranges, extracts the position data representing ranges common to the mutually overlapping ranges each of which is represented by a couple of position data corresponding to the rising and falling edges of a passage timing pulse as read position data of the mark image of the component color, and calculates the amounts of positional deviations of the component color images from one another on the basis of the position data extracted.

Abstract: An image printing apparatus includes a control unit which controls a rotational speed of an image carrier; a detecting unit which detects data of the rotational speed; a storage unit which stores the rotational speeds up to n past rotation cycle of said image carrier; and a determining unit which determines whether a rotational speed difference between a latest rotational speed in a current rotation cycle and a rotational speed in n past rotation cycle before the current rotation cycle at a predetermined interval, which includes the same rotational position in respective rotation cycles and its near position, is more than a predetermined reference value, wherein said control unit controls the rotational speed of said image carrier by using the data of rotational speeds at a predetermined interval including the same rotational position in one or n past rotation cycle before the current rotation cycle, and further said control unit controls a rotational speed in a subsequent rotation cycle next to the current r

Abstract: An image forming apparatus having a color mode and a monochromatic mode, which includes: a transmission member, which can be switched between a transmitted state where a motor transfers a drive force to a single photoreceptor drum and a non-transmitted state where the motor does not transfer the drive force to the single photoreceptor drum; and a controller which switches to the non-transmitted state while executing an image formation in the monochromatic mode, and when a command to execute a next image formation is not instructed, switches to the transmitted state after a phase adjustment of each photoreceptor drum after the image formation in the monochromatic mode, and controls the motor to execute a slight rotation operation at every prescribed period of time by synchronizing plural drums including the single photoreceptor drum with each other through the transmission member.

Abstract: In an image forming apparatus for forming a color image by superposing component color images, a control device obtains position data representing a forming position of each of plural registration mark images for the component color images with respect to a positional reference value arbitrarily determined, divides the position data into each of a unit reference range representing a range in which one mark image is formed, converts the position data divided for each unit reference range into those based on respective reference values representing the front edge of the unit reference ranges, extracts the position data representing ranges common to the mutually overlapping ranges each of which is representing by a couple of position data corresponding to the rising and falling edges of a passage timing pulse as read position data of the mark image of the component color, and calculates the amounts of positional deviations of the component color images from one another on the basis of the position data extracted

Abstract: An image forming apparatus including photoconductor drums corresponding to colors, motors, gears to transmit each rotation of the motors to each of the photoconductor drums, each of two gears comprising a portion to be detected intermittently continuing in a circumferential direction at a position having same radius centering around a rotary shaft of the gears, a pair of phase sensors to output detection signals of signal logics according to an existence or a non-existence of the portion to be detected at a point symmetric position centering around the rotary shaft of each of two gears and a control unit to calculate a rotation phase difference between each of the gears based on a logical combination of the detection signals which are output from the pair of phase sensors and to control the motors so as to synchronize rotation of each of the gears based on the calculated rotation phase difference.

Abstract: In an image forming apparatus for forming a color image by superposing component color images, a control device obtains position data representing a forming position of each of plural registration mark images for the component color images with respect to a positional reference value arbitrarily determined, divides the position data into each of a unit reference range representing a range in which one mark image is formed, converts the position data divided for each unit reference range into those based on respective reference values representing the front edge of the unit reference ranges, extracts the position data representing ranges common to the mutually overlapping ranges each of which is represented by a couple of position data corresponding to the rising and falling edges of a passage timing pulse as read position data of the mark image of the component color, and calculates the amounts of positional deviations of the component color images from one another on the basis of the position data extracted.

Abstract: An image printing apparatus includes a control unit which controls a rotational speed of an image carrier; a detecting unit which detects data of the rotational speed; a storage unit which stores the rotational speeds up to n past rotation cycle of said image carrier; and a determining unit which determines whether a rotational speed difference between a latest rotational speed in a current rotation cycle and a rotational speed in n past rotation cycle before the current rotation cycle at a predetermined interval, which includes the same rotational position in respective rotation cycles and its near position, is more than a predetermined reference value, wherein said control unit controls the rotational speed of said image carrier by using the data of rotational speeds at a predetermined interval including the same rotational position in one or n past rotation cycle before the current rotation cycle, and further said control unit controls a rotational speed in a subsequent rotation cycle next to the current r

Abstract: A color image forming apparatus including: an image forming section which forms an image based on image information on an image carrier provided in the image forming section; a detection section which detects a print mark for color misalignment correction formed on the image carrier by the image forming section, and outputs print mark detection information; and a control section for executing color misalignment correction control based on the print mark detection information outputted from the detection section, wherein, the control section obtains a trend of a color misalignment amount of the print mark by statistically processing data of the result of the print mark detection, calculates an execution timing of color misalignment correction base on the obtained trend, and executes the color misalignment correction at the calculated execution timing.

Abstract: When conducting a color-shift-correcting mode using a registration mark formed by the image forming section on an image carrier, the image detecting section outputs the image detection signal representing the line width of the registration mark and the control section calculates the line width of the registration mark from the image detection signal. The control section compares a line width of the registration mark with a predetermined reference value of the line width to discriminate between abnormality and normality. If normality, the control section continues the color-shift-correcting mode and if abnormality the control section conducts the image forming system restoration mode after stopping the execution of the color-shift-correcting mode. Therefore, even in the case where a white spot is generated for some reasons on the registration mark, the color-shift-correcting mode can be conducted on the normal registration mark with the help of the image forming system restoration mode.

Abstract: Present invention uses the main power source and auxiliary power source to supply power to a load, makes them take partial charge of power supply, and when the load current reaches its peak, detects a current and a voltage generated by the auxiliary power source, and when the detected values are larger than set values or lower than the set values, controls the output current of the main power source.

Abstract: An image printing apparatus includes a control unit which controls a rotational speed of an image carrier; a detecting unit which detects data of the rotational speed; a storage unit which stores the rotational speeds up to n past rotation cycle of said image carrier; and a determining unit which determines whether a rotational speed difference between a latest rotational speed in a current rotation cycle and a rotational speed in n past rotation cycle before the current rotation cycle at a predetermined interval, which includes the same rotational position in respective rotation cycles and its near position, is more than a predetermined reference value, wherein said control unit controls the rotational speed of said image carrier by using the data of rotational speeds at a predetermined interval including the same rotational position in one or n past rotation cycle before the current rotation cycle, and further said control unit controls a rotational speed in a subsequent rotation cycle next to the current r

Abstract: An image printing apparatus includes a control unit which controls a rotational speed of an image carrier; a detecting unit which detects data of the rotational speed; a storage unit which stores the rotational speeds up to n past rotation cycle of said image carrier; and a determining unit which determines whether a rotational speed difference between a latest rotational speed in a current rotation cycle and a rotational speed in n past rotation cycle before the current rotation cycle at a predetermined interval, which includes the same rotational position in respective rotation cycles and its near position, is more than a predetermined reference value, wherein said control unit controls the rotational speed of said image carrier by using the data of rotational speeds at a predetermined interval including the same rotational position in one or n past rotation cycle before the current rotation cycle, and further said control unit controls a rotational speed in a subsequent rotation cycle next to the current r

Abstract: In a document reading apparatus having a scanning exposure reading system by which a document placed on a platen is scanning exposed by an optical system and a document image is read out, or a document reading system by which a moving document is read out by an optical system, at the first collection position and the second collection position which are different in the sub-scanning direction of the scanning expose on a reference density plate, the first shading correction data and the second shading correction data are respectively read in the main scanning direction, and the shading position is corrected on the basis of the read first and second shading correction data.

Abstract: An image printing apparatus includes a control unit which controls a rotational speed of an image carrier; a detecting unit which detects data of the rotational speed; a storage unit which stores the rotational speeds up to n past rotation cycle of said image carrier; and a determining unit which determines whether a rotational speed difference between a latest rotational speed in a current rotation cycle and a rotational speed in n past rotation cycle before the current rotation cycle at a predetermined interval, which includes the same rotational position in respective rotation cycles and its near position, is more than a predetermined reference value, wherein said control unit controls the rotational speed of said image carrier by using the data of rotational speeds at a predetermined interval including the same rotational position in one or n past rotation cycle before the current rotation cycle, and further said control unit controls a rotational speed in a subsequent rotation cycle next to the current r

Abstract: The invention concerns an image-forming apparatus employing a clock-generating circuit, which generates dot clock pulses utilized for an image-writing section of the image-forming apparatus. The clock-generating circuit includes a digital-delay dot clock adjusting section to generate first dot clock pulses having a predetermined number of pulses within a predetermined time interval at a constant exposing range of the image-writing section, wherein each period of the first dot clock pulses is slightly increased or reduced by changing a selection for a plurality of delayed clock pulses, which are generated by delaying clock-pulses, outputted from a reference oscillator, in slightly different delay times; and a jitter suppressing section to suppress a jitter component included in the first dot clock pulses, wherein the jitter suppressing section divides the first dot clock pulses to generate second dot clock pulses, and then, multiplies the second dot clock pulses to generate the dot clock pulses.

Abstract: When conducting a color-shift-correcting mode using a registration mark formed by the image forming means on an image carrier, the image detecting means outputs the image detection signal representing the line width of the registration mark and the control section calculates the line width of the registration from the image detection signal. The control means compares a line width of the registration mark with a predetermined reference value of the line width to discriminate between abnormality and normality. If normality, the control means continues the color-shift-correcting mode and if abnormality the control means conducts the image forming system restoration mode after stopping the execution of the color-shift-correcting mode. Therefore, even in the case where a white spot is generated for some reasons on the registration mark, the color-shift-correcting mode can be conducted on the normal registration mark with the help of the image forming system restoration mode.