Patents by Inventor Hidetoshi Ema
Hidetoshi Ema has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 8243865Abstract: A disclosed data processing apparatus includes: a binarization unit binarizing input data based on a threshold voltage; a capture unit capturing data from a binary output binarized by the binarization unit; a duty cycle detection unit detecting a duty cycle of the binary output; and a control unit controlling a level of the input data based on the duty cycle detected by the duty cycle detection unit.Type: GrantFiled: June 15, 2007Date of Patent: August 14, 2012Assignee: Ricoh Company, Ltd.Inventors: Nobunari Tsukamoto, Hidetoshi Ema
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Patent number: 8194780Abstract: A differential signal output device is disclosed that outputs transmission data as a differential signal. The device includes a first differential signal generation circuit that amplifies a signal representing the transmission data and generates the differential signal from the amplified signal; a dummy data generation circuit that is synchronized with a reference clock of the transmission data and generates dummy data that change only in a bit where the transmission data do not change; and a second differential signal generation circuit that amplifies a signal representing the dummy data and generates another differential signal from the amplified signal.Type: GrantFiled: August 11, 2008Date of Patent: June 5, 2012Assignee: Ricoh Company, Ltd.Inventors: Nobunari Tsukamoto, Hidetoshi Ema
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Patent number: 8023605Abstract: A multiphase delay unit causes different delay times to a reference clock to generate a multiphase clock with different phases. A multiphase sampling unit samples the input signal using the multiphase clock, and outputs multiphase sampling data. A phase selecting unit detects a phase relation of the multiphase clock using the multiphase sampling data, and selects output data from the multiphase sampling data based on a result of detecting the phase relation.Type: GrantFiled: August 27, 2007Date of Patent: September 20, 2011Assignee: Ricoh Company, Ltd.Inventors: Nobunari Tsukamoto, Hidetoshi Ema
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Patent number: 7791634Abstract: 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.Type: GrantFiled: April 20, 2006Date of Patent: September 7, 2010Assignee: Ricoh Company, LimitedInventors: Naruhiro Masui, Hidetoshi Ema, Nobunari Tsukamoto
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Patent number: 7746971Abstract: 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.Type: GrantFiled: March 16, 2006Date of Patent: June 29, 2010Assignee: Ricoh Company, Ltd.Inventors: Naruhiro Masui, Hidetoshi Ema
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Patent number: 7684531Abstract: 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.Type: GrantFiled: December 3, 2004Date of Patent: March 23, 2010Assignee: Ricoh Company, Ltd.Inventors: Naruhiro Masui, Hidetoshi Ema
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Patent number: 7573790Abstract: 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.Type: GrantFiled: October 16, 2006Date of Patent: August 11, 2009Assignee: Ricoh Company, Ltd.Inventors: Naruhiro Masui, Hidetoshi Ema
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Patent number: 7518969Abstract: 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.Type: GrantFiled: October 16, 2006Date of Patent: April 14, 2009Assignee: Ricoh Company, Ltd.Inventors: Naruhiro Masui, Hidetoshi Ema
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Publication number: 20090046784Abstract: A differential signal output device is disclosed that outputs transmission data as a differential signal. The device includes a first differential signal generation circuit that amplifies a signal representing the transmission data and generates the differential signal from the amplified signal; a dummy data generation circuit that is synchronized with a reference clock of the transmission data and generates dummy data that change only in a bit where the transmission data do not change; and a second differential signal generation circuit that amplifies a signal representing the dummy data and generates another differential signal from the amplified signal.Type: ApplicationFiled: August 11, 2008Publication date: February 19, 2009Inventors: Nobunari Tsukamoto, Hidetoshi Ema
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Patent number: 7480230Abstract: A light source drive which modulates a light source so as to cause the same to emit a light, includes: a superposition current generation part which generates a superposition current approximately corresponding to a charging/discharging current needed for a capacitance occurring in parallel to the light source for a predetermined time period near at least one of a rising-up part and a decaying-down part of a waveform of a drive current for the light source; and an addition/subtraction part which adds to or subtracts from the drive current the superposition current generated by the superposition current generation part.Type: GrantFiled: October 17, 2006Date of Patent: January 20, 2009Assignee: Ricoh Company, Ltd.Inventors: Naruhiro Masui, Hidetoshi Ema
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Patent number: 7423940Abstract: A signal processing apparatus is provided with a converter for converting at least one analog light detection signal into a digital light detection signal, and a signal generator for generating at least one servo error signal by subjecting the digital light detection signal to a predetermined operation process. The signal generator has a function of modifying contents of the operation process.Type: GrantFiled: August 23, 2006Date of Patent: September 9, 2008Assignee: Ricoh Company, Ltd.Inventors: Naruhiro Masui, Hidetoshi Ema
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Publication number: 20080143814Abstract: 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.Type: ApplicationFiled: April 20, 2006Publication date: June 19, 2008Inventors: Naruhiro Masui, Hidetoshi Ema, Nobunari Tsukamoto
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Publication number: 20080056420Abstract: A multiphase delay unit causes a different delay time to a reference clock to generate a multiphase clock having a different phase. A multiphase sampling unit samples the input signal using the multiphase clock, and outputs multiphase sampling data. A phase selecting unit detects a phase relation of the multiphase clock using the multiphase sampling data, and selects output data from the multiphase sampling data based on data obtained by detecting the phase relation of the multiphase clock.Type: ApplicationFiled: August 27, 2007Publication date: March 6, 2008Inventors: Nobunari Tsukamoto, Hidetoshi Ema
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Publication number: 20070297548Abstract: A disclosed data processing apparatus includes: a binarization unit binarizing input data based on a threshold voltage; a capture unit capturing data from a binary output binarized by the binarization unit; a duty cycle detection unit detecting a duty cycle of the binary output; and a control unit controlling a level of the input data based on the duty cycle detected by the duty cycle detection unit.Type: ApplicationFiled: June 15, 2007Publication date: December 27, 2007Inventors: Nobunari Tsukamoto, Hidetoshi Ema
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Patent number: 7200091Abstract: 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.Type: GrantFiled: October 21, 2002Date of Patent: April 3, 2007Assignee: Ricoh Company, Ltd.Inventors: Naruhiro Masui, Hidetoshi Ema
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Publication number: 20070070834Abstract: A signal processing apparatus is provided with a converter for converting at least one analog light detection signal into a digital light detection signal, and a signal generator for generating at least one servo error signal by subjecting the digital light detection signal to a predetermined operation process. The signal generator has a function of modifying contents of the operation process.Type: ApplicationFiled: August 23, 2006Publication date: March 29, 2007Inventors: Naruhiro Masui, Hidetoshi Ema
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Patent number: 7193957Abstract: A light source drive which modulates a light source so as to cause the same to emit a light, includes: a superposition current generation part which generates a superposition current approximately corresponding to a charging/discharging current needed for a capacitance occurring in parallel to the light source for a predetermined time period near at least one of a rising-up part and a decaying-down part of a waveform of a drive current for the light source; and an addition/subtraction part which adds to or subtracts from the drive current the superposition current generated by the superposition current generation part.Type: GrantFiled: August 30, 2005Date of Patent: March 20, 2007Assignee: Ricoh Company, Ltd.Inventors: Naruhiro Masui, Hidetoshi Ema
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Publication number: 20070036059Abstract: A light source drive which modulates a light source so as to cause the same to emit a light, includes: a superposition current generation part which generates a superposition current approximately corresponding to a charging/discharging current needed for a capacitance occurring in parallel to the light source for a predetermined time period near at least one of a rising-up part and a decaying-down part of a waveform of a drive current for the light source; and an addition/subtraction part which adds to or subtracts from the drive current the superposition current generated by the superposition current generation part.Type: ApplicationFiled: October 17, 2006Publication date: February 15, 2007Inventors: Naruhiro Masui, Hidetoshi Ema
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Publication number: 20070030784Abstract: 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.Type: ApplicationFiled: October 16, 2006Publication date: February 8, 2007Inventors: Naruhiro Masui, Hidetoshi Ema
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Publication number: 20070030785Abstract: 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.Type: ApplicationFiled: October 16, 2006Publication date: February 8, 2007Inventors: Naruhiro Masui, Hidetoshi Ema