Patents by Inventor Shoji Takeda
Shoji Takeda 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: 10670985Abstract: An image forming apparatus includes a photosensitive member, a light source, a deflecting unit, a storing unit, a correcting unit, and a light source driving portion. Magnification correction data is determined using a quadratic function of a variable representing a scanning position with respect to a scanning direction. Coefficients of two quadratic functions corresponding to adjacent two regions included in a plurality of scanning regions are set so that a differential value calculated at the variable corresponding to a boundary of the two regions by a differential of the quadratic function for one region and a differential value calculated at the variable corresponding to the boundary of the two regions by a differential of the quadratic function for the other region are equal to each other.Type: GrantFiled: November 26, 2018Date of Patent: June 2, 2020Assignee: Canon Kabushiki KaishaInventor: Shoji Takeda
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Patent number: 10567617Abstract: An image processing apparatus includes (A) a dither processing unit to perform dither processing on first image data to generate second image data, the second image data including a target pixel and an adjacent pixel, each of the pixels having a density value, the density value of the target pixel being greater than that of the adjacent pixel, and the density value of the adjacent pixel being not greater than a predetermined density, (B) a diffusing unit (a) to determine an error value resulting at the target pixel, (b) to diffuse the error value to pixels subsequent to the target pixel, and not to diffuse an error value resulting at the adjacent pixel to pixels subsequent to the adjacent pixel.Type: GrantFiled: March 13, 2018Date of Patent: February 18, 2020Assignee: Canon Kabushiki KaishaInventor: Shoji Takeda
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Publication number: 20190243275Abstract: The information processing apparatus includes: a detector configured to detect a change in a predetermined signal; and a specifier configured to specify a reflective surface used to scan a photosensitive member, based on a timing at which the change is detected. The detector is further configured to, in a period until specifying the reflective surface, detect the change after a predetermined amount of time has passed after the change has been detected, and after specifying the reflective surface, detect the change after an amount of time based on the specified reflective surface has passed after the change has been detected.Type: ApplicationFiled: January 25, 2019Publication date: August 8, 2019Inventor: Shoji Takeda
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Publication number: 20190171129Abstract: An image forming apparatus includes a photosensitive member, a light source, a deflecting unit, a storing unit, a correcting unit, and a light source driving portion. Magnification correction data is determined using a quadratic function of a variable representing a scanning position with respect to a scanning direction. Coefficients of two quadratic functions corresponding to adjacent two regions included in a plurality of scanning regions are set so that a differential value calculated at the variable corresponding to a boundary of the two regions by a differential of the quadratic function for one region and a differential value calculated at the variable corresponding to the boundary of the two regions by a differential of the quadratic function for the other region are equal to each other.Type: ApplicationFiled: November 26, 2018Publication date: June 6, 2019Inventor: Shoji Takeda
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Patent number: 10243493Abstract: A pulse generation unit is configured to output pulse signals for driving the stepping motor. A control unit is configured to perform acceleration control or deceleration control of the stepping motor via the pulse generation unit. The control unit is configured to calculate a number of the pulse signals to be output from the pulse generation unit to the stepping motor when accelerating or decelerating the stepping motor at constant acceleration in the acceleration control or the deceleration control based on an initial speed of the stepping motor when the acceleration control or the deceleration control starts, a target rotation speed, and time from start control of the stepping motor to time when the stepping motor reaches the target rotation speed, and change a rotation speed of the stepping motor in the acceleration control or the deceleration control along a sinusoidal waveform.Type: GrantFiled: December 5, 2017Date of Patent: March 26, 2019Assignee: CANON KABUSHIKI KAISHAInventor: Shoji Takeda
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Patent number: 10158782Abstract: Separately providing a shift register for performing serial-to-parallel conversion on a BD signal and a shift register for performing parallel-to-serial conversion on a bit pattern to generate a PWM signal increases the scale of a circuit for adjusting a writing start position in the scanning direction of a light beam. Therefore, the shift register for performing serial-to-parallel conversion on a BD signal and the shift register for performing parallel-to-serial conversion on a bit pattern to generate a PWM signal are configured as a common register.Type: GrantFiled: May 10, 2017Date of Patent: December 18, 2018Assignee: CANON KABUSHIKI KAISHAInventor: Shoji Takeda
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Publication number: 20180278800Abstract: An image processing apparatus of the invention, includes: an error value calculation unit configured to calculate an error value in a target pixel from a concentration value in the target pixel of input image data, and a PWM error value calculated on the basis of a light amount of laser light which is actually emitted on the basis of a PWM signal of a pulse width corresponding to the concentration value, and a light amount of ideal laser light corresponding to the pulse width; and a concentration value calculation unit configured to add the error value calculated in peripheral pixels positioned in the vicinity of the target pixel to the concentration value at a predetermined ratio, in which the error value calculation unit sets the error value in the target pixel to 0 according to the concentration value or a pixel position of the target pixel.Type: ApplicationFiled: March 13, 2018Publication date: September 27, 2018Inventor: Shoji Takeda
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Publication number: 20180167006Abstract: A pulse generation unit is configured to output pulse signals for driving the stepping motor. A control unit is configured to perform acceleration control or deceleration control of the stepping motor via the pulse generation unit. The control unit is configured to calculate a number of the pulse signals to be output from the pulse generation unit to the stepping motor when accelerating or decelerating the stepping motor at constant acceleration in the acceleration control or the deceleration control based on an initial speed of the stepping motor when the acceleration control or the deceleration control starts, a target rotation speed, and time from start control of the stepping motor to time when the stepping motor reaches the target rotation speed, and change a rotation speed of the stepping motor in the acceleration control or the deceleration control along a sinusoidal waveform.Type: ApplicationFiled: December 5, 2017Publication date: June 14, 2018Inventor: Shoji Takeda
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Patent number: 9983502Abstract: A setting unit of a controller mounted on a control board sets a first mode for generating, from image data, PWM data indicating a pattern for causing an LD to emit light and transmitting to a laser driving board, or a second mode for transmitting to the laser driving board image data prior to generation of the PWM data. A data conversion unit, in the first mode, converts inputted image data into N pieces of PWM data respectively corresponding to N LDs, and in the second mode, converts inputted image data into image data for each scanning line. A P/S conversion unit converts data outputted from the data conversion unit from a serial format into a parallel format, and transmits the converted data to the laser driving board as control data.Type: GrantFiled: November 10, 2016Date of Patent: May 29, 2018Assignee: CANON KABUSHIKI KAISHAInventors: Shoji Takeda, Katsuyuki Yamazaki
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Patent number: 9935624Abstract: A PWM signal generating apparatus configured to generate a PWM signal by applying parallel serial conversion to pattern data obtained by converting input data into a waveform pattern of a PWM signal having one pulse divided into a predetermined number of pulses, the PWM signal generating apparatus including: a clock generating circuit configured to generate a plurality of clock signals having mutually different phases; a conversion circuit configured to convert the input data into the waveform pattern of the PWM signal; an encoding circuit configured to generate, from the waveform pattern, a plurality of encoded signals synchronized with respective clocks of the plurality of clock signals generated by the clock generating circuit; and a decoding circuit configured to generate the PWM signal from the plurality of encoded signals output from the encoding circuit.Type: GrantFiled: July 22, 2016Date of Patent: April 3, 2018Assignee: CANON KABUSHIKI KAISHAInventor: Shoji Takeda
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Publication number: 20170331973Abstract: Separately providing a shift register for performing serial-to-parallel conversion on a BD signal and a shift register for performing parallel-to-serial conversion on a bit pattern to generate a PWM signal increases the scale of a circuit for adjusting a writing start position in the scanning direction of a light beam. Therefore, the shift register for performing serial-to-parallel conversion on a BD signal and the shift register for performing parallel-to-serial conversion on a bit pattern to generate a PWM signal are configured as a common register.Type: ApplicationFiled: May 10, 2017Publication date: November 16, 2017Inventor: Shoji Takeda
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Publication number: 20170146923Abstract: A setting unit of a controller mounted on a control board sets a first mode for generating, from image data, PWM data indicating a pattern for causing an LD to emit light and transmitting to a laser driving board, or a second mode for transmitting to the laser driving board image data prior to generation of the PWM data. A data conversion unit, in the first mode, converts inputted image data into N pieces of PWM data respectively corresponding to N LDs, and in the second mode, converts inputted image data into image data for each scanning line. A P/S conversion unit converts data outputted from the data conversion unit from a serial format into a parallel format, and transmits the converted data to the laser driving board as control data.Type: ApplicationFiled: November 10, 2016Publication date: May 25, 2017Inventors: Shoji Takeda, Katsuyuki Yamazaki
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Publication number: 20170040989Abstract: A PWM signal generating apparatus configured to generate a PWM signal by applying parallel serial conversion to pattern data obtained by converting input data into a waveform pattern of a PWM signal having one pulse divided into a predetermined number of pulses, the PWM signal generating apparatus including: a clock generating circuit configured to generate a plurality of clock signals having mutually different phases; a conversion circuit configured to convert the input data into the waveform pattern of the PWM signal; an encoding circuit configured to generate, from the waveform pattern, a plurality of encoded signals synchronized with respective clocks of the plurality of clock signals generated by the clock generating circuit; and a decoding circuit configured to generate the PWM signal from the plurality of encoded signals output from the encoding circuit.Type: ApplicationFiled: July 22, 2016Publication date: February 9, 2017Inventor: Shoji Takeda
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Patent number: 8892932Abstract: The present image forming apparatus includes a first control unit and a second control unit driven by built-in clock oscillators to realize the distributed control. The first control unit generates, using a first timer driven by the built-in clock oscillator of the first control unit, a pulse signal corresponding to a predetermined clock rate and outputs the pulse signal to the second control unit. The second control unit measures, using a second timer driven by the built-in clock oscillator of the second control unit, a pulse width of the pulse signal outputted from the first control unit, and calculates a correction coefficient using reference pulse width corresponding to the predetermined clock rate and the measured pulse width. The processing unit processes using the calculated correction coefficient.Type: GrantFiled: March 7, 2011Date of Patent: November 18, 2014Assignee: Canon Kabushiki KaishaInventors: Keita Takahashi, Atsushi Otani, Shoji Takeda, Satoru Yamamoto, Hirotaka Seki
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Patent number: 8804154Abstract: This invention provides an image forming apparatus to which a distributed control system is applied and which improves error detection accuracy in each control unit. To accomplish this, the image forming apparatus includes a master control unit which controls the overall image forming apparatus, a plurality of sub-master control units which control a plurality of functions required to implement image formation, and a plurality of slave control units which control loads required to implement the plurality of functions. Each slave control unit includes a monitoring unit which monitors the operation of the other active slave control unit and performs an error diagnosis when the slave control unit is inactive.Type: GrantFiled: February 24, 2010Date of Patent: August 12, 2014Assignee: Canon Kabushiki KaishaInventors: Atsushi Otani, Akihiko Sakai, Keita Takahashi, Hirotaka Seki, Shoji Takeda, Satoru Yamamoto, Shigeo Hata
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Patent number: 8615675Abstract: This invention provides an image forming apparatus that suppresses a control error between CPUs when the CPUs operate in cooperation with each other in distributed control by the CPUs. To accomplish this, the image forming apparatus utilizes a distributed control system. Respective CPUs measure time interval concerning image formation processing using their built-in clock oscillators, and perform operations in cooperation with each other. Correction coefficients are calculated based on the time interval measured by the respective CPUs to correct a measurement error generated by the operation an error of the respective clock oscillators. Clock count values each indicating a timing to drive a load is corrected based on the correction coefficients.Type: GrantFiled: August 6, 2010Date of Patent: December 24, 2013Assignee: Canon Kabushiki KaishaInventors: Hirotaka Seki, Atsushi Otani, Shoji Takeda, Satoru Yamamoto, Keita Takahashi
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Patent number: 8605306Abstract: The image forming apparatus has the plurality of control units and executes distributed processing in which any one control unit having monitoring execution authority monitors for an abnormal condition in each control unit. Each control unit determines, from its own processing load, monitoring capability information that indicates whether monitoring for an abnormal condition is possible or not. If, in a case where the control unit has the monitoring execution authority, the monitoring capability information does not satisfy predetermined information, then the control unit delegates the monitoring execution authority to another control unit whose monitoring capability information does satisfy the predetermined information.Type: GrantFiled: June 23, 2011Date of Patent: December 10, 2013Assignee: Canon Kabushiki KaishaInventors: Keita Takahashi, Atsushi Otani, Shoji Takeda, Satoru Yamamoto, Hirotaka Seki
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Patent number: 8576427Abstract: There are provided an image forming apparatus which implements divisional control using a plurality of control units without an increase in cost and a control method for the apparatus. To accomplish this, this image forming apparatus includes a master control unit that controls the overall image forming apparatus, a plurality of sub-master control units that control a plurality of functions for performing image formation, and a plurality of salve control units that control loads for implementing a plurality of functions. The master control unit is connected to the plurality of sub-master control units via first signal lines. The plurality of sub-master control units are connected to the plurality of slave control units via second signal lines higher in data transfer timing accuracy than the first signal lines.Type: GrantFiled: February 25, 2010Date of Patent: November 5, 2013Assignee: Canon Kabushiki KaishaInventors: Akihiko Sakai, Atsushi Otani, Shigeo Hata, Shoji Takeda, Satoru Yamamoto, Keita Takahashi, Hirotaka Seki
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Patent number: 8520265Abstract: An engraving processing apparatus includes a laser engraving unit configured to perform engraving processing for forming a recessed portion on a sheet by irradiating a laser beam onto the sheet, and a controller configured to control an engraving processing operation of the laser engraving unit.Type: GrantFiled: June 13, 2007Date of Patent: August 27, 2013Assignee: Canon Kabushiki KaishaInventors: Hideaki Kosasa, Masahiko Yokota, Wataru Kawata, Toshiro Tomono, Ryuichi Kojima, Akihiro Shimizu, Shoji Takeda
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Patent number: 8503013Abstract: There is provided an image forming apparatus which adopts a distributed control system and suppresses generation of radiation noise without increasing the cost. To accomplish this, the image forming apparatus includes a master control unit that controls the overall image forming apparatus, a plurality of sub-master control units that control a plurality of functions for performing image formation, and a plurality of salve control units that control loads for implementing a plurality of functions. The image forming apparatus performs distributed control. The image forming apparatus determines the operating frequencies of the salve control units in accordance with loads controlled by the salve control units. The image forming apparatus compares the operating frequencies of the slave control units. Based on the comparison result, the image forming apparatus changes the operating frequency of a slave control unit that is equal to the operating frequency of another slave control unit.Type: GrantFiled: March 16, 2010Date of Patent: August 6, 2013Assignee: Canon Kabushiki KaishaInventors: Hirotaka Seki, Shigeo Hata, Atsushi Otani, Akihiko Sakai, Shoji Takeda, Satoru Yamamoto, Keita Takahashi