Abstract: When an image forming apparatus shifts to a power saving mode, a controller unit further reduces power consumption by switching AC current on/off every predetermined amount of time. When AC current input from a commercial AC power supply is turned off, a DC voltage generating circuit normally can no longer supply a DC voltage, rendering the controller unit unable to operate. Accordingly, the controller unit operates using a charge accumulated in a smoothing capacitor while the AC current is not being supplied. An AC cutting circuit is switched on before a both-end voltage at the smoothing capacitor drops below a lower limit of operation voltage of the DC voltage generating circuit, and the smoothing capacitor is recharged.

Abstract: A first X capacitor is connected between one of a plurality of hot line sections of a hot line that is located at an output side of a first relay as viewed from a commercial alternating-current power supply, and one of a plurality of neutral line sections of a neutral line that is located at an input side of a second relay as viewed from the commercial alternating-current power supply. A second X capacitor is connected between one of the hot line sections that is located at the output side of the first relay as viewed from the commercial alternating-current power supply, and one of the neutral line sections that is located at an output side of the second relay as viewed from the commercial alternating-current power supply.

Abstract: When a detection signal indicates that a switch has switched off, a first relay cuts off the supply of alternating current from a commercial alternating-current source to a third DC power source and terminates a first load such as a motor and a high-voltage power source. When the detection signal indicates that the switch has switched off, a control circuit executes shutdown processing for safely terminating an operation of a second load such as a hard disk drive. When the shutdown processing is complete, the control circuit outputs a signal for terminating an operation of a second DC power source. When the shutdown signal is input, a second relay terminates the operation of the second load by cutting off the supply of the alternating current from the commercial alternating-current source to a second DC power source.

Abstract: When an image forming apparatus shifts to a power saving mode, a controller unit further reduces power consumption by switching AC current on/off every predetermined amount of time. When AC current input from a commercial AC power supply is turned off, a DC voltage generating circuit normally can no longer supply a DC voltage, rendering the controller unit unable to operate. Accordingly, the controller unit operates using a charge accumulated in a smoothing capacitor while the AC current is not being supplied. An AC cutting circuit is switched on before a both-end voltage at the smoothing capacitor drops below a lower limit of operation voltage of the DC voltage generating circuit, and the smoothing capacitor is recharged.

Abstract: When a detection signal indicates that a switch has switched off, a first relay cuts off the supply of alternating current from a commercial alternating-current source to a third DC power source and terminates a first load such as a motor and a high-voltage power source. When the detection signal indicates that the switch has switched off, a control circuit executes shutdown processing for safely terminating an operation of a second load such as a hard disk drive. When the shutdown processing is complete, the control circuit outputs a signal for terminating an operation of a second DC power source. When the shutdown signal is input, a second relay terminates the operation of the second load by cutting off the supply of the alternating current from the commercial alternating-current source to a second DC power source.

Abstract: A first X capacitor is connected between one of a plurality of hot line sections of a hot line that is located at an output side of a first relay as viewed from a commercial alternating-current power supply, and one of a plurality of neutral line sections of a neutral line that is located at an input side of a second relay as viewed from the commercial alternating-current power supply. A second X capacitor is connected between one of the hot line sections that is located at the output side of the first relay as viewed from the commercial alternating-current power supply, and one of the neutral line sections that is located at an output side of the second relay as viewed from the commercial alternating-current power supply.

Abstract: There is provided an image forming apparatus, which is free from erroneous operations of a plurality of operation parts provided in the apparatus. A selector selects at least one operation part out of a plurality of operation parts, and a main CPU invalidates a predetermined operation by at least one operation part that is not selected by the selector, out of the plurality of operation parts.

Abstract: Forming an image by utilizing a scanning device for scanning a color image for each color element, a reading device for reading image data for each scanned line, a rotary polygon mirror for deflecting, in a main scan direction, a modulated light beam that is based on the image data for each read line, so that an image holding member that is rotated in a sub-scan direction is scanned by the deflected light beam and a latent image is formed thereon, a first generation device for determining whether the light beam deflected by the rotary polygon mirror has scanned a predetermined location, and for generating a main scan start reference signal, and a second generation device for generating a sub-scan start reference signal in synchronization with the rotation of the image holding member, a first control device that controls the rotary polygon mirror and the rotary image holding member, so as to maintain a phase difference between the sub-scan start reference signal and the main scan start reference signal, no mat

Abstract: There is provided an image forming apparatus, which is free from erroneous operations of a plurality of operation parts provided in the apparatus. A selector selects that selects at least one operation part out of a plurality of operation parts, and a main CPU invalidates a predetermined operation by at least one operation part that is not selected by the selector, out of the plurality of operation parts.

Abstract: The color determination circuit 308 detects hue of the color image information, and the controller 205 decides a color component to be separated (separation color) in accordance with the detected hue. Output color by the printer 204 is set in correspondence with the separation color. The two-color-separating circuit 303 separates the color image information into image information on at least two color components in accordance with the decided separation colors. The separated image information on the each color is transmitted to the printer 204 via printer density correction circuits 304 and 305, and a buffer 306. Thereby it is possible to provide an image processing apparatus capable of setting and changing the separation color and the output color by automatic operation or by simple manual operation, thus the expression of the image forming can be improved.

Abstract: It is one object of the present invention to maintain a constant original document reading start position and a constant image forming start position for each color element, and to obtain a high quality color image with less variance in the image reproductivity of individual color elements.

Abstract: The invention intends to match the image writing start positions for different color components, even in case of the rotation speed of the photosensitive member etc. fluctuates by the variation in the load or by the backlash of the driving gears. For attaining this object, the invention is featured by a configuration of detecting and retaining the phase difference between the ITOP signal and the BD signal at a predetermined timing, also detecting the phase difference between the ITOP signal and the BD signal for each formation of the color component image, comparing the phase difference detected at the predetermined timing with that detected for each formation of the color component image, and controlling the timing of starting the image formation by changing, by an image writing tart timing control circuit, the number of BD signal to be counted after the generation of ITOP signal and before the start of image formation.

Abstract: In forming a multi-colored image by superimposing a plurality of plane images, positional offsets of the plane images are prevented, thereby obtaining high quality color images. The timing at which image data corresponding to each plane image is generated is controlled in accordance with the phase difference between the sub-scanning start signal indicating the rotational timing of an image carrier and the main-scanning start signal representing the rotational timing of a rotating polygonal mirror. Various controls are further performed.

Abstract: An image forming apparatus discriminates a color of an inputted color image for each pixel and generates a first color component and a second color component. The apparatus compares values of the first and the second color components, and selects and outputs the color component having a larger value. Meanwhile a color component which is not selected is diffused to neighboring pixels. When pixels neighboring a pixel of interest in a predetermined area are filled with one color component, the other color component is selected and outputted regardless of the values of the first and second color components.

Abstract: When an original image of a full color is reconstructed by two colors, it is intended to prevent that a part of the original image is not reconstructed. An image of a full color original is read by a CCD, thereby forming signals of R, G and B. In an image processing unit, the R, G, and B signals are converted into red and black signals. The red and black signals are sent to a printer unit and an image is formed in red and black.

Abstract: An image forming apparatus having a timer function includes a main switch for manually switching between supply and interruption of electric power to the apparatus, a detector for detecting whether the main switch is in a power-interruption state or in a power-supply state, a memory for storing a state indicating that the main switch is in a power-interruption state when it has been detected that the main switch is in a power-interruption state, a controller for placing the apparatus in a standby state in which an image can be formed or in a shutdown state in which an image cannot be formed during a preset time period, and a power supply for supplying power to the controller, wherein the apparatus is placed in a standby state even by a set shutdown time period in the case a power-interruption state is stored and wherein the apparatus is placed in a shutdown state during the set shutdown time period in the case the power-interruption state is not stored.

Abstract: An image forming apparatus discriminates a color of an inputted color image for each pixel and generates a first color component and a second color component. The apparatus compares values of the first and the second color components, and selects and outputs the color component having a larger value. Meanwhile a color component which is not selected is diffused to neighboring pixels. When pixels neighboring a pixel of interest in a predetermined area are filled with one color component, the other color component is selected and outputted regardless of the values of the first and second color components.