Abstract: A method for measuring a deviation in timing of start of writing in scanning lines is implemented by an optical scanning device that scans a surface to be scanned with light beams from light-emitting elements having first and second light-emitting elements which are arranged so as to be displaced from each other in a direction corresponding to a direction of the scanning lines. The method includes: detecting timing at which light from the first light-emitting element is received by a light receiving element, as a first time, the light receiving element outputting a synchronization detecting signal before start of writing; detecting timing at which light from the second light-emitting element is received by the light receiving element, as a second time; and obtaining the deviation in timing for the second light-emitting element with respect to the first light-emitting element based on a difference between the first and second time.

Abstract: A moving-member detecting device includes an image acquiring unit and a speed calculating unit. The image acquiring unit includes a light source configured to emit a light beam to a detecting position of a moving member; an area sensor configured to acquire image data of a one- or two-dimensional image; and an area-sensor control unit configured to acquire the image data. The image acquiring unit is configured to acquire pieces of image data of the moving member at first and second positions, respectively, in a moving direction of the moving member so as to acquire the piece of position image data for the second position when the moving member is at the second position after acquiring the piece of image data for the first position. The speed calculating unit is configured to calculate a moving speed of the moving member from the pieces of image data.

Abstract: An image forming apparatus that forms an image includes: a photosensitive element; an optical scanning device that includes a light source, and scans a surface of the photosensitive element in a main scanning direction with light emitted from the light source to form a latent image; a developing unit that develops the latent image; a photosensitive element period detecting sensor that detects a rotation period of the photosensitive element; a density sensor that detects a density variation of an image developed by the developing unit, in a sub scanning direction; and a processing device that corrects a driving signal of the light source according to the image information, based on an output signal of the density sensor and an output signal of the photosensitive element period detecting sensor.

Abstract: A deflector deflects a light beam emitted from a light source including a plurality of light-emitting units. A scanning optical system focuses the light beam deflected by the deflector on a scanning target surface. A monitoring photoreceiver receives a part of a light beam deflected by the deflector and directed toward an area within a scanning area outside an image area. A detecting unit individually detects emission powers of at least two light-emitting units based on an output signal of the monitoring photoreceiver in a single sweep of scanning.

Abstract: In a light-source driving device, a high-frequency clock generating circuit generates two high-frequency clock signals having mutually different phases, an image-data creating circuit creates a plurality of image data corresponding to a plurality of light-emitting units according to image information, and a write control circuit creates a plurality of modulated data corresponding to the light-emitting units from the plurality of image data and separately controls output timings of the plurality of modulated data by using a time, as a unit, corresponding to a phase difference between the two high-frequency clock signals. The write control circuit includes two data switching circuits that set a correspondence relation between image data and PWM data based on one of a relation between an array of the light-emitting units and an array of a plurality of light spots and a relation between a surface to be scanned and a main scanning direction.

Abstract: A light scanning apparatus having plural light sources includes a light source control unit configured to control the light sources to form L (L?2) light beam arrays aligned in a sub scanning direction each of which L light beam arrays are formed by causing M ((N?1)?M?1) light sources out of N (N?2) light sources assigned to each of the L light beam arrays to emit light as M light emitting sources, wherein each of the L light beam arrays forms a pixel and a total of L pixels aligned in the sub scanning direction are formed.

Abstract: A write control circuit includes a first data switching circuit that sets a correspondence relationship between signals from line buffers and input signals to a delay circuitry, based on a signal from a CPU; and a second data switching circuit that sets a correspondence relationship between output signals of the delay circuitry and drive signals, based on a signal from the CPU. This enables a plurality of light emitting sections to be driven properly, regardless of a main scanning direction and an arrangement of a plurality of light spots being in any of CASE-1 to CASE-4 in an optical scanning device.

Abstract: A disclosed optical scanner includes a light source unit and a control unit configured to control the light source unit. Light emitted from the light source unit is scanned to expose a scan object surface and form an image on the scan object surface. The light source unit includes plural light sources arranged at a density equal to N (N being an integer of two or more) times higher than a density of pixels on the scan object surface. The control unit controls the light source unit such that one pixel is formed by at least two of the light sources.

Abstract: A light-source driving device includes a high-frequency clock generating circuit that generates high-frequency clock signals of which phases are different from each other; an image-data generating circuit that generates a plurality of pieces of image data corresponding to light emitting units in accordance with image information; a write control circuit that generates a plurality of pieces of modulation data corresponding to the light emitting units based on the image data and adjusts output timing of the modulation data individually in units of time corresponding to a phase difference of the high-frequency clock signals; and a light-source driving circuit that drives the light emitting units based on a plurality of pieces of PWM data output from the write control circuit.

Abstract: An image forming apparatus that forms an image includes: a photosensitive element; an optical scanning device that includes a light source, and scans a surface of the photosensitive element in a main scanning direction with light emitted from the light source to form a latent image; a developing unit that develops the latent image; a photosensitive element period detecting sensor that detects a rotation period of the photosensitive element; a density sensor that detects a density variation of an image developed by the developing unit, in a sub scanning direction; and a processing device that corrects a driving signal of the light source according to the image information, based on an output signal of the density sensor and an output signal of the photosensitive element period detecting sensor.

Abstract: An optical scanning device includes n-odd (n?2) light sources disposed at different positions at least in a sub-scanning direction, a pixel forming part in which one pixel is depicted by light beams emitted from m-odd (n?m?2) light sources of the n-odd light sources and a distance of adjacent light sources for emitting the light beams in the sub-scanning direction is less than 5 ?m, and a light source driving control part configured to control an emitting state of the light sources for depicting the one pixel and conduct an emission driving control for moving a gravity center of the one pixel in the sub-scanning direction.

Abstract: A pixel clock generator that generates a pixel clock to regulate a drive timing of a scanning light source includes a data generating circuit that generates phase data based on a phase data pattern to correct an uneven scanning speed and fluctuation of scanning widths, and a pixel clock generating circuit generates a pixel clock having a long cycle based on a high-frequency clock and that performs a phase shift for the pixel clock based on the high-frequency clock. The phase pattern is set-such that difference in an amount of the phase shift between the pixel clocks adjacent to each other does not exceed a basic amount of the phase shift of the pixel clock generating circuit.

Abstract: A light-source drive control unit divides each pixel of the image data into a plurality of subpixels, deletes certain subpixels from the image data in accordance with predetermined correction data, shifts remaining subpixels in the sub-scanning direction thereby obtaining reduced image data, and controls a plurality of light sources based on the reduced image data in such a manner that one line of the subpixels is formed with a light beam emitted from a corresponding one of the light sources.

Abstract: A method for measuring a deviation in timing of start of writing in scanning lines is implemented by an optical scanning device that scans a surface to be scanned with light beams from light-emitting elements having first and second light-emitting elements which are arranged so as to be displaced from each other in a direction corresponding to a direction of the scanning lines. The method includes: detecting timing at which light from the first light-emitting element is received by a light receiving element, as a first time, the light receiving element outputting a synchronization detecting signal before start of writing; detecting timing at which light from the second light-emitting element is received by the light receiving element, as a second time; and obtaining the deviation in timing for the second light-emitting element with respect to the first light-emitting element based on a difference between the first and second time.

Abstract: A pixel clock and pulse-modulation-signal generating device includes a high-frequency-clock generating unit that generates a high-frequency clock; a modulation-data generating unit that generates, based on pixel control data that specifies a pixel length and image data, phase data that indicates a transition timing of a pixel clock and modulation data that indicates a desired bit pattern that corresponds to the image data; a pixel-clock generating unit that generates a pixel clock based on the high-frequency clock, the phase data, and a horizontal synchronization signal; and a serial-modulation-signal generating unit that inputs the modulation data, and outputs a pulse modulation signal in a serial pulse string based on the high-frequency clock.

Abstract: An optical scanning apparatus that includes a light source unit having plural main light sources that are two-dimensionally arranged in the main scanning direction and the sub scanning direction, and plural sub light sources that are arranged between rows of the main light sources aligned in the main scanning direction. The optical scanning apparatus also includes an optical system configured to scan light emitted from the light source unit on a scanning object to form an image on the scanning object, and a control apparatus configured to adjust a main scanning direction image position by controlling two of the main light sources that are juxtaposed to each other with respect to the main scanning direction and adjust a sub scanning direction image position by controlling a main light source and a sub light source that are adjacent to each other.

Abstract: An image forming apparatus includes an optical scanning device that scans a scan area on an image carrier with light flux containing image information and writes the image information onto an image area in the scan area. In the optical scanning device, a first light receiving unit receives light flux emitted from a light source and reflected by a reflecting optical unit; a second light receiving unit receives light flux that passes through an aperture of the reflecting optical unit, is deflected by a deflecting unit, and heads for outside the image area within the scan area; and a control unit controls a drive signal of the light source based on signals output from the first and second light receiving units.

Abstract: An optical scanning device of the invention includes: n-odd (n?2) light sources disposed at different positions at least in a sub scanning direction; a light source driving control part configured to control a light emitting state of the light source; and a sub-scanning pixel position detecting part configured to depict one pixel with m-odd (n?m?2) light sources of the n-odd (n?2) light sources and to detect a deviation in position of the one pixel in a sub scanning direction, wherein the light source driving control part is configured to correct the deviation in position of the one pixel in the sub scanning direction at a resolution equal to or higher than a density of the pixel, depicted with the m-odd light sources, by controlling the light emitting state of the m-odd light sources on the basis of a result of detection with the sub-scanning pixel position detecting part.

Abstract: In a pixel clock creation method and device, a high frequency clock is created. A scanning time needed to scan a predetermined scanning length is detected in accuracy of half a period of the high frequency clock to output a detection value indicating the detected scanning time. The detection value and a predetermined target value are compared to output a comparison result. A phase data is created based on the comparison result. A pixel clock whose phase is controlled based on both the high frequency clock and the phase data is created.

Abstract: A light scanning apparatus is provided that has plural light sources which scan plural light beams in a main scanning direction. The light scanning apparatus comprises a light source control unit that controls the plural light sources. Where an array of N (N?2) light sources aligned in a sub scanning direction and capable of scanning different positions in the sub scanning direction is called a virtual light source array, and where L (L?2) virtual light source arrays aligned in the sub scanning direction are formed, the light source control unit causes M ((N?1)?M?1) light sources out of the N light sources of each of the L virtual light source arrays to emit light to form a pixel and thereby to form a total of L pixels aligned in the sub scanning direction by giving the same data to the M light sources of each of the L virtual light source arrays.