Abstract: The present invention discloses an electric signal outputting apparatus in a serial electric transmission system. The electric signal outputting apparatus includes a switching part for switchably generating high and low output signals in accordance with signal data and transmitting the output signals to a transmission path, an impedance matching part for matching an output impedance to the impedance of the transmission path, and an auxiliary switching part for subsidiarily supplying current to an output node in the transmission path and subsidiarily absorbing current from the output node in the transmission path when the switching part switches the generation between high and low output signals, wherein the auxiliary switching part conducts the supplying and the absorbing for a period shorter than a pulse width of a reference clock of the serial electric transmission system.

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 semiconductor laser modulation signal is generated for modulating a semiconductor laser. The semiconductor laser is driven based on the semiconductor laser modulation signal. An output impedance of a semiconductor laser modulation signal generating unit and an input impedance of a semiconductor laser driving unit are corrected. The semiconductor laser modulation signal is transmitted as a low amplitude differential signal, from the semiconductor laser modulation signal generating unit to the semiconductor laser driving unit.

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: A disclosed device for generating a pulse-width modulated signal according to image data and based on a pixel clock signal includes a pixel clock generating unit configured to generate the pixel clock signal and a modulated data generating unit configured to generate the pulse-width modulated signal. The pixel clock generating unit includes a multi-phase clock signal generating unit, a comparing unit, a frequency calculation unit, a counting unit, and a pixel clock signal output unit. The modulated data generating unit includes a data converting unit, an edge time calculation unit, and a pulse-width modulated signal output unit.

Abstract: A high-frequency clock generating circuit generates a plurality of high-frequency clock signals having different phases. A modulation-signal generating circuit generates a pulse modulation signal based on transition timing data including data pertaining to a turn-on timing at which a state of a light source is changed from a turn-off state to a turn-on state and a turn-off timing at which the state of the light source is changed from the turn-on state to the turn-off state by inputting any one of the high-frequency clock signals for a predetermined period including the turn-on timing and the turn-off timing.

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: 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: 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 output device is disclosed that includes an impedance matching section including an impedance adjustment section, and a dummy circuit section having the same configuration as the impedance adjustment section and adapted to calculate an adjustment value for matching an output impedance to a characteristic impedance of the transmission line. The impedance matching section sets the adjustment value to an impedance adjustment section, thereby matching the output impedance to the characteristic impedance. The output device further includes a switching transistor configured to be turned on/off so as to switch the output between an H level and an L level, and a constant current driver configured to add a constant current to the output.

Abstract: An optical scanner includes a light source unit configured to emit light; an optical system configured to cause the light emitted from the light source unit to scan an object so as to form an image on the object; and a control unit configured to control the light source unit. The light source unit includes a plurality of light emitting units arranged in a sub scanning direction, and the control unit controls the light source unit to emit light at different positions on the object by using either n (n: positive integer) light emitting units or n+1 light emitting units selected from among the plurality of light emitting units, according to a positional shift amount of the image in the sub scanning direction.

Abstract: A laser modulating and driving device comprises a modulation signal generating unit configured to generate a laser modulation signal consisting of a pair of small swing differential signals based on pixel data, and a driving unit configured to drive a laser according to the laser modulation signal supplied from the modulation signal generating unit.

Abstract: A pixel clock generation circuit is disclosed, including a high frequency clock generation unit configured to generate high frequency clock, a clock modulation data generation unit configured to generate clock modulation data based on pixel clock phase data indicating timing of a transition in pixel clock. The pixel clock generation circuit further includes a modulation clock generation unit configured to modulate the frequency and phase of the high frequency clock based on the modulation data thereby to generate modulated pixel clock.

Abstract: An oscillation frequency control part includes a voltage-to-current converting circuit converting an input voltage to a current having a value corresponding to the input voltage, and outputting a current in proportion to the current obtained from the voltage-to-current converting circuit. An oscillating circuit part includes a ring oscillator, wherein a current in proportion to the output current of the oscillation frequency control part flows through the ring oscillator so that the oscillation frequency in the ring oscillator is controlled by the output current of the oscillation frequency control part. The voltage-to-current converting circuit has linear voltage-to-current conversion characteristics in a predetermined range of the input voltage including a ground potential.

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: 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: 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 disclosed device for generating a pulse-width modulated signal according to image data and based on a pixel clock signal includes a pixel clock generating unit configured to generate the pixel clock signal and a modulated data generating unit configured to generate the pulse-width modulated signal. The pixel clock generating unit includes a multi-phase clock signal generating unit, a comparing unit, a frequency calculation unit, a counting unit, and a pixel clock signal output unit. The modulated data generating unit includes a data converting unit, an edge time calculation unit, and a pulse-width modulated signal output unit.

Abstract: The present invention discloses an electric signal outputting apparatus in a serial electric transmission system. The electric signal outputting apparatus includes a switching part for switchably generating high and low output signals in accordance with signal data and transmitting the output signals to a transmission path, an impedance matching part for matching an output impedance to the impedance of the transmission path, and an auxiliary switching part for subsidiarily supplying current to an output node in the transmission path and subsidiarily absorbing current from the output node in the transmission path when the switching part switches the generation between high and low output signals, wherein the auxiliary switching part conducts the supplying and the absorbing for a period shorter than a pulse width of a reference clock of the serial electric transmission system.

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.