Abstract: An image forming apparatus capable of properly performing an initialization of a control circuit including a laser diode driver circuit, includes a light source, a photoreceptor, a deflector, and a controller. The photoreceptor is built in the light source to detect incident light. The deflector deflects the laser light into a scanning laser beam. The controller controls the light source to light on and off, and obtains a laser light emission amount of the light source relative to a current flowing through the light source based on a detection of incident light by the photoreceptor. The controller determines the laser light emission amount of the light source during a time period when a path of the laser light from the light source is headed to a reflection surface of the deflector at an incident angle of approximately ninety degrees.

Abstract: An image forming apparatus and method that detects a light beam deflected by a polygon mirror at least at two separate locations on the line in the horizontal scanning direction, measures the difference in time of passage between these locations, makes a comparison between the thus determined interval and a reference interval, and generates a proper amount of correction corresponding to the determined interval, such as either correction data adapted to change the frequency of a pixel clock, or further correction data to change the period of the pixel clock by pixels.

Abstract: Image forming units each form an image of one color, which are superimposed to form a color image, and a pattern used for correcting deviation of the image. A first detector positioned at an image writing starting side, and a second and a third detector each detects the pattern. A first and a second correcting unit having different precisions correct a deviation of an image writing position based on detection by the first detector. A third and a fourth correcting unit having different precisions correct a total-width magnification error based on detections by the second and the third detector. The fourth correcting unit further corrects a partial magnification error.

Abstract: An image forming apparatus includes a light source that emits a light beam in a main scanning direction according to image data to be used for image formation, a control unit that controls the light source, and detectors that detect the light beam. The main scanning direction is divided into areas and a cycle of a pixel clock is corrected in each area independently based on detection results of the detectors so as to correct an image position and image magnification.

Abstract: A color image forming apparatus forming a full color image by superimposing images of individual colors includes a correction possibility determination device to determine whether or not deviations in position and errors in magnification ratio of images of individual colors that are superimposed on top of one another to form a full color image can be correctly performed and a correction device to perform the operation of correcting deviations in position and errors in magnification ratio of individual colors that are superimposed on top of one another to form a full color image.

Abstract: A color image forming apparatus forming a full color image by superimposing images of individual colors includes a correction possibility determination device to determine whether or not deviations in position and errors in magnification ratio of images of individual colors that are superimposed on top of one another to form a full color image can be correctly performed and a correction device to perform the operation of correcting deviations in position and errors in magnification ratio of individual colors that are superimposed on top of one another to form a full color image.

Abstract: In an image forming apparatus, a pattern forming unit forms a pattern for ameliorating image positional displacement, and a detecting unit detects the pattern. An ameliorating unit ameliorates an image positional displacement based on the pattern detected. If for example, the pattern cannot be detected, then e.g., monochrome printing is enabled, and a notifying unit notifies that the amelioration is not possible.

Abstract: A light beam scanning device is disclosed that includes a light emission source to emit a light beam, a deflection part to deflect the emitted light beam in the main scanning direction, first and second light beam detection parts to detect the deflected light beam at first and second positions, respectively, outside an image area on the opposite sides thereof in the main scanning direction, a time difference measurement part to measure the time difference between the light beam detections by the first and second light beam detection parts, and a control part to perform control so as to correct image magnification in the main scanning direction in the image area from the measured time difference. The control part performs control so that the condition of the amount of light at the time of detecting the light beam by the first and second light beam detection parts is constant.

Abstract: An image forming apparatus that forms a multi-color image by superposing a plurality of monochrome images is provided. The image forming apparatus includes, for each color, an image forming unit that forms the monochrome image; a pattern forming unit that forms a predetermined compensation pattern; a pattern position detecting unit that detects the position of the compensation pattern formed by the pattern forming unit; and an image position adjusting unit that adjusts the position of the monochrome image to be formed by the image forming unit based on the position of the compensation pattern detected by the pattern position detecting unit. Since the compensation pattern is formed under an image forming condition adjustable independently from another image forming condition with which the monochrome images are formed, the image forming apparatus can adjust positional deviation of monochrome images.

Abstract: An image forming apparatus includes at least one image forming mechanism configured to form an image based on image data. Each image forming mechanism includes an optical system, a sensor, an electronic circuit, and a controller. The optical system scans a photosensitive member with a light beam based on image data. The sensor detects the light beam and the electronic circuit stores a correction data table containing light amount data of the light source and corresponding start position shift amount data. The controller controls a light amount of the light source and adjusts a start position of image recording on the photosensitive member in accordance with a sync detect signal. The controller includes a write start position correction unit that adjust the start position of the image recording based on a start position shift amount data when the light amount varies.

Abstract: An image forming apparatus including a light beam generating and modulating device that generates and modulates a light beam based on an image signal, and a light beam deflecting device that deflects the modulated light beam and scans an image carrier to form an image. A pair of light beam detecting devices detects the deflected light beam at two separate positions on a main scanning line. A time difference measuring device measures a time difference between time periods when the light beam is detected by one of the light beam detecting devices and by the other of the light beam detecting devices. An image magnification correcting device changes write clock frequency of the light beam and rotation number of the light deflecting device based on the time difference to correct magnification error in the main scanning direction of the image on the image carrier.

Abstract: An image forming apparatus is constructed to include an image bearing member which is rotatably supported to bear a toner image, a light beam scanning section to simultaneously scan the image bearing member by a plurality of light beams so as to form an electrostatic latent image, a developing section to develop the electrostatic latent image into the toner image, a transfer section to transfer the toner image onto a recording medium, and an ON start timing adjuster to adjust an ON start timing of one of the plurality of light beams, based on an image tone of each of a plurality of patterns of an image pattern formed by the light beam scanning section.

Abstract: A color image forming apparatus forming a full color image by superimposing images of individual colors includes a correction possibility determination device to determine whether or not deviations in position and errors in magnification ratio of images of individual colors that are superimposed on top of one another to form a full color image can be correctly performed and a correction device to perform the operation of correcting deviations in position and errors in magnification ratio of individual colors that are superimposed on top of one another to form a full color image.

Abstract: An optical recording apparatus includes a light source, a scanner, and a phase shift controller. The light source emits a light beam controlled to be lit on and off in synchronism with a pixel clock signal according to input image data. The scanner reforms the light beam emitted by the light source into a cyclic scanning light beam scanning in a main scanning direction a photosensitive surface moving in a sub-scanning direction. The phase shift controller performs an image magnification correction by a phase change for changing a phase of the pixel clock signal in units of one nth of a cycle of the pixel clock signal at one or more positions on the photoconductive surface in the main scanning direction, in which n is an integer greater than one. A method and apparatus of optical image forming is also described.

Abstract: An image forming apparatus that forms a multi-color image by superposing a plurality of monochrome images is provided. The image forming apparatus includes, for each color, an image forming unit that forms the monochrome image; a pattern forming unit that forms a predetermined compensation pattern; a pattern position detecting unit that detects the position of the compensation pattern formed by the pattern forming unit; and an image position adjusting unit that adjusts the position of the monochrome image to be formed by the image forming unit based on the position of the compensation pattern detected by the pattern position detecting unit. Since the compensation pattern is formed under an image forming condition adjustable independently from another image forming condition with which the monochrome images are formed, the image forming apparatus can adjust positional deviation of monochrome images.

Abstract: An image forming apparatus is constructed to include an image bearing member which is rotatably supported to bear a toner image, a light beam scanning section to simultaneously scan the image bearing member by a plurality of light beams so as to form an electrostatic latent image, a developing section to develop the electrostatic latent image into the toner image, a transfer section to transfer the toner image onto a recording medium, and an ON start timing adjuster to adjust an ON start timing of one of the plurality of light beams, based on an image tone of each of a plurality of patterns of an image pattern formed by the light beam scanning section.

Abstract: An image forming apparatus includes at least one image forming mechanism configured to form an image based on image data. Each image forming mechanism includes an optical system, a sensor, an electronic circuit, and a controller. The optical system scans a photosensitive member with a light beam based on image data. The sensor detects the light beam and the electronic circuit stores a correction data table containing light amount data of the light source and corresponding start position shift amount data. The controller controls a light amount of the light source and adjusts a start position of image recording on the photosensitive member in accordance with a sync detect signal. The controller includes a write start position correction unit that adjust the start position of the image recording based on a start position shift amount data when the light amount varies.

Abstract: An image forming apparatus includes a modulation data storage, a pulse width modulator, and an optical writing mechanism. The modulation data storage stores different gray-scale pulse sets. Each set includes gray-scale pulses having pulse widths different from each other in steps of a predetermined value corresponding to gray-scale information possibly contained in image data to be input. Each gray-scale pulse includes at least two pulses including at least one of left-positioned and right-positioned pulses. The pulse width modulator selects a gray-scale pulse set from among the different gray-scale sets in accordance with gray-scale information and performs a pulse width modulation to control a light beam on and off at a density twice or more than twice a density of the input image data by using the gray-scale pulse set selected. The optical writing mechanism causes the light beam to scan a photosensitive member to form a latent image thereon.

Abstract: An image forming apparatus includes a light beam generating and modulating device which generates and modulates a light beam in accordance with an image signal, a light beam deflecting device which deflects the modulated light beam and scans an image carrier so as to form an image.

Abstract: An electrophotographic image forming apparatus including an LED (Light Emitting Diode) array head and a method of generating data for correcting the quantities of light to issue form the LEDs of the LED array head are disclosed. Only the quantity of light that actually contributes to development is uniformed throughout the LEDs. This reduces the scatter of a dot area in a latent image and thereby enhances image quality while insuring the sufficient resolution of the LEDs.