Abstract: A head driving device drives a liquid ejection head. The liquid ejection head includes a plurality of nozzles and a plurality of pressure generating devices provided respectively corresponding to the nozzles. The head driving device includes a driving-waveform correcting unit configured to correct driving waveform data that defines ejection characteristics of liquid to be ejected from the nozzle based on interference patterns expressing variations in the ejection characteristics caused by an interference occurring in the nozzle.

Abstract: A head driving device drives a liquid ejection head. The liquid ejection head includes a plurality of nozzles and a plurality of pressure generating devices provided respectively corresponding to the nozzles. The head driving device includes a driving-waveform correcting unit configured to correct driving waveform data that defines ejection characteristics of liquid to be ejected from the nozzle based on interference patterns expressing variations in the ejection characteristics caused by an interference occurring in the nozzle.

Abstract: The invention is concerning a head driving device that drives a recording head including a plurality of nozzles and a plurality of pressure generating elements corresponding to the respective nozzles. The head driving device comprises: a plurality of drive waveform generating units corresponding to the respective pressure generating elements, wherein the drive waveform generating units drive the respective pressure generating elements on the basis of pieces of drive waveform information that are set for the respective nozzles so as to approximately equalize ejection characteristics of droplets ejected from the nozzles.

Abstract: The invention is concerning a head driving device that drives a recording head including a plurality of nozzles and a plurality of pressure generating elements corresponding to the respective nozzles. The head driving device comprises: a plurality of drive waveform generating units corresponding to the respective pressure generating elements, wherein the drive waveform generating units drive the respective pressure generating elements on the basis of pieces of drive waveform information that are set for the respective nozzles so as to approximately equalize ejection characteristics of droplets ejected from the nozzles.

Abstract: A pixel clock generating device includes a time interval detection unit detecting a time interval between a first signal and a second signal in each of cyclically repeating N (?2) time periods; a comparing unit cyclically selecting a target value from N target values corresponding to the N time periods and outputting an error indicating a difference between the detected time interval and the selected target value for each of the N time periods; a frequency calculation unit correcting a frequency of the pixel clock signal based on the error and cyclically generating a frequency specification signal indicating the corrected frequency for each of the N time periods; a high-frequency clock generating unit generating a high-frequency clock signal; and a pixel clock generating unit generating a pixel clock signal based on the frequency specification signal and the high-frequency clock signal.

Abstract: An image forming apparatus includes a color registration error amount calculation unit that calculates a color registration error amount from a first test pattern; a correction information obtaining unit that obtains a correction information for correcting an image on a back surface based on previously obtained contraction information of a printing paper after printing an image on a front surface when printing on both surfaces; and an image data correction unit that corrects the image on the back surface based on the color registration error amount calculated by the color registration error amount and the correction information obtained by the correction information obtaining unit.

Abstract: An image forming apparatus includes an intermediate transfer body; a generating unit generating test pattern data; a storage unit storing a color displacement amount; a correcting unit correcting the test pattern data and image data based on the color displacement amount currently stored in the storage unit; a forming unit forming a test pattern based on the test pattern data corrected by the correcting unit on the intermediate transfer body at predetermined intervals, and forming an image based on the image data corrected by the correcting unit on the intermediate transfer body; a detecting unit detecting the test pattern formed on the intermediate transfer body; an updating unit determining an amount of change of the color displacement amount from a result of detection by the detecting unit, and updating the color displacement amount stored in the storage unit by using the amount of change of the color displacement amount.

Abstract: An image forming apparatus reduces superimposing misalignment due to skew difference and registration difference and superimposing misalignment of visible image due to periodic position error generated on a plurality of latent image carriers respectively by correcting image information. A controller of the image forming apparatus has a deviation amount storing unit store data of magnification error in the sub-scanning direction e, executes rotation posture determining process that sets writing rotation posture as rotation angle posture at the time of starting writing latent image on photoconductors for Y, M, C, and K respectively, and has an image data correcting unit correct the image information based on the determined writing rotation posture and various error data (including magnification error in the sub-scanning direction e).

Abstract: An image forming apparatus includes a color registration error amount calculation unit that calculates a color registration error amount from a first test pattern; a correction information obtaining unit that obtains a correction information for correcting an image on a back surface based on previously obtained contraction information of a printing paper after printing an image on a front surface when printing on both surfaces; and an image data correction unit that corrects the image on the back surface based on the color registration error amount calculated by the color registration error amount and the correction information obtained by the correction information obtaining unit.

Abstract: A pixel clock generator includes a frequency divider 4 that generates a pixel clock PCLK based on a high frequency clock VCLK, a comparator 5 that calculates an error Lerr in the time obtained by integrating a cycle of the pixel clock PCLK for a target number RefN from a time when synchronization signals SPSYNC and EPSYNC are detected, a filter 6, and a frequency calculating unit 7 that sets a frequency dividing value M of the frequency divider 4. The filter 6 and the frequency calculating unit 7 calculate an average of a frequency of the pixel clock PCLK based on the error Lerr, determine a reference error value from the error Lerr in N-cycles, calculate offset values of the frequencies of N pieces of pixel clocks PCLK based on a difference between the reference error value and the error Lerr, and calculate the frequency dividing value M based on a result obtained by adding the circularly selected offset values and the average of the frequency of the pixel clock PCLK.

Abstract: An image forming apparatus includes an intermediate transfer body; a generating unit generating test pattern data; a storage unit storing a color displacement amount; a correcting unit correcting the test pattern data and image data based on the color displacement amount currently stored in the storage unit; a forming unit forming a test pattern based on the test pattern data corrected by the correcting unit on the intermediate transfer body at predetermined intervals, and forming an image based on the image data corrected by the correcting unit on the intermediate transfer body; a detecting unit detecting the test pattern formed on the intermediate transfer body; an updating unit determining an amount of change of the color displacement amount from a result of detection by the detecting unit, and updating the color displacement amount stored in the storage unit by using the amount of change of the color displacement amount.

Abstract: An image forming apparatus reduces superimposing misalignment due to skew difference and registration difference and superimposing misalignment of visible image due to periodic position error generated on a plurality of latent image carriers respectively by correcting image information. A controller of the image forming apparatus has a deviation amount storing unit store data of magnification error in the sub-scanning direction e, executes rotation posture determining process that sets writing rotation posture as rotation angle posture at the time of starting writing latent image on photoconductors for Y, M, C, and K respectively, and has an image data correcting unit correct the image information based on the determined writing rotation posture and various error data (including magnification error in the sub-scanning direction e).

Abstract: A pixel clock generating device includes a time interval detection unit detecting a time interval between a first signal and a second signal in each of cyclically repeating N (?2) time periods; a comparing unit cyclically selecting a target value from N target values corresponding to the N time periods and outputting an error indicating a difference between the detected time interval and the selected target value for each of the N time periods; a frequency calculation unit correcting a frequency of the pixel clock signal based on the error and cyclically generating a frequency specification signal indicating the corrected frequency for each of the N time periods; a high-frequency clock generating unit generating a high-frequency clock signal; and a pixel clock generating unit generating a pixel clock signal based on the frequency specification signal and the high-frequency clock signal.

Abstract: A pixel clock generator includes a frequency divider 4 that generates a pixel clock PCLK based on a high frequency clock VCLK, a comparator 5 that calculates an error Lerr in the time obtained by integrating a cycle of the pixel clock PCLK for a target number RefN from a time when synchronization signals SPSYNC and EPSYNC are detected, a filter 6, and a frequency calculating unit 7 that sets a frequency dividing value M of the frequency divider 4. The filter 6 and the frequency calculating unit 7 calculate an average of a frequency of the pixel clock PCLK based on the error Lerr, determine a reference error value from the error Lerr in N-cycles, calculate offset values of the frequencies of N pieces of pixel clocks PCLK based on a difference between the reference error value and the error Lerr, and calculate the frequency dividing value M based on a result obtained by adding the circularly selected offset values and the average of the frequency of the pixel clock PCLK.

Abstract: A comparator compares a time interval between a first synchronization signal and a second synchronization signal with a target value, and outputs an error therebetween. A frequency calculator calculates a set value of a pixel clock frequency based on the error output from the comparator, and outputs a frequency specification signal for specifying a pixel clock frequency according to the calculated set value. A frequency divider divides a high frequency clock generated by a high frequency clock generator by a frequency division ratio based on the frequency specification signal output from the frequency calculator, and generates the pixel clock.

Abstract: Serially transferred data is over sampled with a multiphase clock signal generated as a result of shifting a predetermined frequency clock signal by a predetermined phase each, to obtain over sampling data; generating clock patterns, having mutually different phase states according to a data phase state of the over sampling data. A first phase pattern generated from the over sampling data is compared with a second phase pattern generated from the clock pattern, and the number of bits to extract from the over sampling data is controlled. A phase error of the over sampling data is detected based on the first phase pattern and the second phase pattern. Bits to extract from the over sampling data is selected to restore the data based on the phase state of the clock pattern and the phase error.

Abstract: A data recovery method includes the steps of: (a) oversampling data that have been transmitted serially in sync with a first clock of frequency f1, using a multiphase clock generated by shifting a phase of a second clock of frequency f2 at a prescribed interval, the second frequency f2 of the multiphase clock being at or below the first frequency f1; (b) extracting f1/f2 bits on average from the oversampled data; and (c) recovering the extracted bits to restore the received data.

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 light source driving unit includes a modulating signal generating section generating modulating signals based on driving waveform generating information of a light source, a current source selecting section selecting one or more currents output from current sources based on the modulating signals, a light source driving section generating a current having multi-levels based on the one or more currents selected and supplying the generated current to the light source to drive the light source so that light in multi-levels is generated from the light source, and a cancelling section adding a signal error amount which cancels differences in amounts of signal delays generated between the modulating signal generating section and the light source driving section at a stage prior to the current source selecting section.

Abstract: A light source driving unit includes a modulating signal generating section generating modulating signals based on driving waveform generating information of a light source, a current source selecting section selecting one or more currents output from current sources based on the modulating signals, a light source driving section generating a current having multi-levels based on the one or more currents selected and supplying the generated current to the light source to drive the light source so that light in multi-levels is generated from the light source, and a cancelling section adding a signal error amount which cancels differences in amounts of signal delays generated between the modulating signal generating section and the light source driving section at a stage prior to the current source selecting section.