Patents by Inventor Takeshi Shikama
Takeshi Shikama 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: 8576267Abstract: An optical writing device stores pieces of dithering information indicating dithering patterns whose densities are different, each piece of dithering information including pieces of identification information associated with pixels of the corresponding dithering pattern, and stores pieces of pixel setting information in which pieces of colored/colorless information indicating each of the pixels is colored or colorless are associated with the pieces of identification information, the pieces of colored/colorless information being set based on a resolution of a light source for forming an electrostatic latent image. The optical writing device also includes a control unit configured to arrange the same dithering patterns in a way that the dithering patterns form a pattern with a given size, and cause the light source to emit light based on information generated by setting the pixels of each of the same dithering patterns to be colored or colorless in accordance with the pixel setting information.Type: GrantFiled: May 17, 2012Date of Patent: November 5, 2013Assignee: Ricoh Company, LimitedInventors: Motohiro Kawanabe, Tatsuya Miyadera, Masayuki Hayashi, Kunihiro Komai, Yasuo Yamaguchi, Yoshinori Shirasaki, Takeshi Shikama, Izumi Kinoshita, Susumu Miyazaki, Takuhei Yokoyama
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Patent number: 8547409Abstract: A light emission control device images an electrostatic latent image on a photosensitive element by a plurality of light emitting elements corresponding to a line in a second direction perpendicular to a first direction which is a rotational direction the photosensitive element. The light emission control device includes: a detecting unit that detects a rotational position of the photosensitive element, in the first direction, corresponding to a line in the second direction; an acquiring unit that acquires a distance between the light emitting elements and the rotational position of the photosensitive element in the first direction detected by the detecting unit; and a control unit that controls light emission by the light emitting elements according to the distance acquired by the acquiring unit and corrects a fluctuation in a density of a visible image converted from the electrostatic latent image.Type: GrantFiled: November 30, 2011Date of Patent: October 1, 2013Assignee: Ricoh Company, LimitedInventors: Takuhei Yokoyama, Izumi Kinoshita, Kunihiro Komai, Tatsuya Miyadera, Yoshinori Shirasaki, Takeshi Shikama, Akinori Yamaguchi
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Publication number: 20130242318Abstract: In the invention, an inclination amount of sensors is reflected in positional deviation correction patterns, and for correcting formation positions of images of various colors, the positional deviation correction patterns are formed on a conveying belt. The positional deviation correction patterns are detected by the sensors. A control unit calculates positional deviation correction amounts based on detection results of the positional deviation correction patterns. Based on the calculated positional deviation correction amounts, the control unit performs calculation for correcting the positional deviation correction patterns, and cancels the inclination amount reflected in the calculation results to obtain final positional deviation correction amounts. Skew correction is performed based on the final positional deviation correction amounts, and thus, the positional deviations are corrected.Type: ApplicationFiled: March 1, 2013Publication date: September 19, 2013Inventors: Akinori YAMAGUCHI, Masayuki HAYASHI, Hiroaki IKEDA, Kunihiro KOMAI, Tatsuya MIYADERA, Takeshi SHIKAMA, Takuhei YOKOYAMA, Yoshinori SHIRASAKI, Motohiro KAWANABE
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Publication number: 20130207339Abstract: According to an embodiment, provided is an image forming device that includes: an image forming unit forming an image in a predetermined cycle in a direction orthogonal to a conveying direction of a printing medium; a velocity acquisition unit acquiring a conveying velocity of the printing medium at a position where the image is formed by the image forming unit; and a correcting unit correcting the cycle on which the image forming unit forms the image in accordance with the conveying velocity acquired by the velocity acquisition unit.Type: ApplicationFiled: February 7, 2013Publication date: August 15, 2013Inventors: Takuhei YOKOYAMA, Yoshinori SHIRASAKI, Tatsuya MIYADERA, Masayuki HAYASHI, Kunihiro KOMAI, Motohiro KAWANABE, Hiroaki IKEDA, Takeshi SHIKAMA, Akinori YAMAGUCHI
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Patent number: 8482588Abstract: An optical writing device that forms an electrostatic latent image on a photoreceptor. The device includes a pixel-information acquiring unit, a line-pixel-information storage unit that stores the acquired pixel information corresponding to a plurality of lines for each main scanning line, a light source device that exposes the photoreceptor with a period corresponding to an N-fold sub-scanning direction resolution of the pixel information, a positional-shift-information storage unit that stores a positional shift information, a sub-line counting unit that counts a sub-line period, a reading-line selecting unit that performs N times of selection that determines which main scanning line is selected as the line from which the pixel information is read out, on the basis of a calculated value from the counted value of the sub-line period and the positional shift information, and a pixel-information reading unit.Type: GrantFiled: September 12, 2011Date of Patent: July 9, 2013Assignee: Ricoh Company, LimitedInventors: Tatsuya Miyadera, Kunihiro Komai, Izumi Kinoshita, Yoshinori Shirasaki, Takeshi Shikama, Takuhei Yokoyama, Akinori Yamaguchi
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Publication number: 20130084109Abstract: An image forming apparatus can transfer a plurality of color component images onto a surface of a recording medium to form an image on the recording medium. The image forming apparatus includes a pattern generation part to generate information about an alignment pattern to be used for a calibration of an image forming, a plurality of stations each including a photosensitive drum to form an alignment pattern corresponding to each of a plurality of color components onto a carry belt or the recording medium, and a read part to detect a plurality of alignment patterns formed by the plurality of stations.Type: ApplicationFiled: October 3, 2012Publication date: April 4, 2013Inventors: Takeshi SHIKAMA, Masayuki HAYASHI, Kunihiro KOMAI, Tatsuya MIYADERA, Motohiro KAWANABE, Yoshinori SHIRASAKI, Hiroaki IKEDA, Akinori YAMAGUCHI, Takuhei YOKOYAMA
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Patent number: 8411124Abstract: A pixel information acquiring unit acquires multilevel pixel information in which one pixel is expressed in multilevel scales. A line pixel information storing unit stores the multilevel pixel information for each main scanning line. A light emission control unit optically exposes a photosensitive element by controlling a binary light source on the basis of the multilevel pixel information. The photosensitive element is exposed to the binary light source with a period corresponding to N-fold in a sub scanning direction resolution of the multilevel pixel information, wherein N is a positive integer, so that the N times exposures corresponds to an exposure for one pixel in an original resolution. The switch on/off statuses of the binary light source are controlled in the N times exposures for each pixel, on the basis of lighting rate information for converting the multilevel scales into a lighting rate in the N times exposures.Type: GrantFiled: September 2, 2011Date of Patent: April 2, 2013Assignee: Ricoh Company, LimitedInventors: Izumi Kinoshita, Kunihiro Komai, Tatsuya Miyadera, Yoshinori Shirasaki, Takuhei Yokoyama, Takeshi Shikama, Akinori Yamaguchi
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Publication number: 20130063536Abstract: A light source control apparatus which controls, based on image data input, light emission of a light source which forms an electrostatic latent image on an image bearing body in an electrophotographic image forming apparatus is disclosed, including a pattern generating unit which generates an internal pattern for position aligning and concentration correcting according to the image data; and a mirroring processing unit which performs a process of mirroring the image data and the internal pattern at a later stage of the pattern generating unit.Type: ApplicationFiled: August 24, 2012Publication date: March 14, 2013Inventors: Kunihiro KOMAI, Masayuki Hayashi, Hiroaki Ikeda, Takeshi Shikama, Akinori Yamaguchi, Tatsuya Miyadera, Motohiro Kawanabe, Yoshinori Shirasaki, Takuhei Yokoyama
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Publication number: 20120300010Abstract: An optical writing device stores pieces of dithering information indicating dithering patterns whose densities are different, each piece of dithering information including pieces of identification information associated with pixels of the corresponding dithering pattern, and stores pieces of pixel setting information in which pieces of colored/colorless information indicating each of the pixels is colored or colorless are associated with the pieces of identification information, the pieces of colored/colorless information being set based on a resolution of a light source for forming an electrostatic latent image. The optical writing device also includes a control unit configured to arrange the same dithering patterns in a way that the dithering patterns form a pattern with a given size, and cause the light source to emit light based on information generated by setting the pixels of each of the same dithering patterns to be colored or colorless in accordance with the pixel setting information.Type: ApplicationFiled: May 17, 2012Publication date: November 29, 2012Inventors: Motohiro KAWANABE, Tatsuya Miyadera, Masayuki Hayashi, Kunihiro Komai, Yasuo Yamaguchi, Yoshinori Shirasaki, Takeshi Shikama, Izumi Kinoshita, Susumu Miyazaki, Takuhei Yokoyama
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Publication number: 20120262750Abstract: An image forming apparatus includes plural image forming units of plural colors, each including a print head including plural LED chips aligned in a main scanning direction; a screen angle selecting unit that selects screen angles for the plural colors respectively based on the amounts of skew of the plural image forming units; an image processing unit that performs image processing on input data to be expressed by pixels of the plural colors such that the pixels of the colors have the corresponding screen angles selected by the screen angle selecting unit; a correction amount determining unit that determines a total amount of skew correction based on the amount of skew detected by the skew detection unit, and determines the amounts of skew correction in the sub-scanning direction for predetermined groups of the pixels, based on the total amount of skew correction, for each of the colors.Type: ApplicationFiled: April 11, 2012Publication date: October 18, 2012Applicant: RICOH COMPANY, LTD.Inventors: Izumi KINOSHITA, Tatsuya Miyadera, Motohiro Kawanabe, Takeshi Shikama, Susumu Miyazaki, Takuhei Yokoyama
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Publication number: 20120229866Abstract: An image forming apparatus performs pseudo gradation processing using dithering, and includes an image carrier; a plurality of light-emitting element arrays arranged in a main-scanning direction and including a plurality of light-emitting elements; an image forming unit performing lighting control of the arrays and forming a pattern image on the image carrier; a detecting unit detecting a density of the pattern image; a position detecting unit detecting a position in the main-scanning direction of the detecting unit with respect to the light-emitting element arrays; a determining unit that, based on the detected position, determines whether the detecting unit is positioned at a proper detection position with respect to the pattern image on which noise has no effect; and an operation control unit that, when the detecting unit is positioned at the proper detection position, performs an image density detection operation on the pattern image using the detecting unit.Type: ApplicationFiled: March 8, 2012Publication date: September 13, 2012Inventors: Susumu MIYAZAKI, Izumi KINOSHITA, Motohiro KAWANABE, Takeshi SHIKAMA, Takuhei YOKOYAMA, Tatsuya MIYADERA
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Publication number: 20120154827Abstract: A line-head control device that controls a line head includes: a calculation unit that divides image data into a plurality of areas in sub-scanning direction and calculates a printing percentage for each of the areas; an allocation unit that allocates a total correction amount, for correcting magnification of the image data in the sub-scanning direction, to the areas according to the printing percentage for each of the areas calculated by the calculation unit; and a control unit that changes an emission period of the light emitted from the line head so as to satisfy a partial correction amount that is an allocation of the total correction amount to each of the areas, exposes the image carrier to the light emitted from the line head with the changed light emission period, thereby causing a latent image to be formed on the image carrier based on the image data.Type: ApplicationFiled: November 21, 2011Publication date: June 21, 2012Inventors: Yoshinori SHIRASAKI, Izumi KINOSHITA, Kunihiro KOMAI, Tatsuya MIYADERA, Takeshi SHIKAMA, Takuhei YOKOYAMA, Akinori YAMAGUCHI
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Publication number: 20120147114Abstract: A light emission control device images an electrostatic latent image on a photosensitive element by a plurality of light emitting elements corresponding to a line in a second direction perpendicular to a first direction which is a rotational direction the photosensitive element. The light emission control device includes: a detecting unit that detects a rotational position of the photosensitive element, in the first direction, corresponding to a line in the second direction; an acquiring unit that acquires a distance between the light emitting elements and the rotational position of the photosensitive element in the first direction detected by the detecting unit; and a control unit that controls light emission by the light emitting elements according to the distance acquired by the acquiring unit and corrects a fluctuation in a density of a visible image converted from the electrostatic latent image.Type: ApplicationFiled: November 30, 2011Publication date: June 14, 2012Inventors: Takuhei YOKOYAMA, Izumi Kinoshita, Kunihiro Komai, Tatsuya Miyadera, Yoshinori Shirasaki, Takeshi Shikama, Akinori Yamaguchi
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Publication number: 20120062682Abstract: An embodiment of the image processing apparatus for controlling the lighting of a line head that is driven with binary data and performs exposure with subline lighting to thereby form images, includes: a subline generating unit that generates a plurality of sublines from a same image data; an inclination correcting unit that exposes the generated sublines so as to generate correction image data used to correct an inclination of an exposure position; a gradation control unit that controls the lighting of sublines based on the correction image data generated by the inclination correcting unit to express gradation; and a light intensity correction unit that corrects and controls the light intensity based on the correction image data generated by the inclination correcting unit, wherein an output of the gradation control unit and an output of the light intensity correction unit are input into the line head in parallel.Type: ApplicationFiled: September 12, 2011Publication date: March 15, 2012Inventors: Kunihiro KOMAI, Izumi Kinoshita, Tatsuya Miyadera, Yoshinori Shirasaki, Takuhei Yokoyama, Takeshi Shikama, Akinori Yamaguchi
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Publication number: 20120062681Abstract: An optical writing device that forms an electrostatic latent image on a photoreceptor. The device includes a pixel-information acquiring unit, a line-pixel-information storage unit that stores the acquired pixel information corresponding to a plurality of lines for each main scanning line, a light source device that exposes the photoreceptor with a period corresponding to an N-fold sub-scanning direction resolution of the pixel information, a positional-shift-information storage unit that stores a positional shift information, a sub-line counting unit that counts a sub-line period, a reading-line selecting unit that performs N times of selection that determines which main scanning line is selected as the line from which the pixel information is read out, on the basis of a calculated value from the counted value of the sub-line period and the positional shift information, and a pixel-information reading unit.Type: ApplicationFiled: September 12, 2011Publication date: March 15, 2012Inventors: Tatsuya MIYADERA, Kunihiro Komai, Izumi Kinoshita, Yoshinori Shirasaki, Takeshi Shikama, Takuhei Yokoyama, Akinori Yamaguchi
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Publication number: 20120061909Abstract: An image processing apparatus includes a reading part configured to optically read skew amount measurement patterns and opposite ends of a paper sheet; an image skew amount detecting part configured to detect skew amounts on a color basis based on the skew amount measurement patterns; a paper sheet skew amount detecting part configured to detect a skew amount of the paper sheet based on a displacement between the opposite ends of the paper sheet; a skew correction amount calculating part configured to calculate skew correction amounts of the respective colors based on the skew amounts; and a skew correcting part configured to shift the images to correct the skews by recording input image data in plural lines of a line memory, dividing the input image data into plural areas in a main scanning direction, and setting line delay amounts on an area basis based on the skew correction amounts.Type: ApplicationFiled: September 2, 2011Publication date: March 15, 2012Applicant: RICOH COMPANY, LTD.Inventors: Takeshi SHIKAMA, Tatsuya MIYADERA, Izumi KINOSHITA, Kunihiro KOMAI, Yoshinori SHIRASAKI, Akinori YAMAGUCHI, Takuhei YOKOYAMA
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Publication number: 20120057889Abstract: An image processing apparatus for an image forming apparatus including a line head array that forms an image by illuminating one or more illumination elements in correspondence with image data. The image processing apparatus includes a detection part configured to detect a linear image extending in a sub-scanning direction in the image data, and an adjustment part configured to adjust a density of the linear image so that the energy used in illuminating the one or more illumination elements for forming the linear image is reduced compared to the energy used in forming the linear image without adjusting the density of the linear image.Type: ApplicationFiled: August 29, 2011Publication date: March 8, 2012Applicant: RICOH COMPANY, LTD.Inventors: Akinori YAMAGUCHI, Tatsuya Miyadera, Izumi Kinoshita, Kunihiro Komai, Yoshinori Shirasaki, Takuhei Yokoyama, Takeshi Shikama
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Publication number: 20120056961Abstract: An optical writing device is provided with a pixel information acquiring unit that acquires multilevel pixel information in which one pixel is expressed in multilevel scales, a line pixel information storing unit that stores the multilevel pixel information for each main scanning line, a light emission control unit that optically exposes the photosensitive element by controlling the binary light source on the basis of the multilevel pixel information. The photosensitive element is exposed to the binary light source with a period corresponding to N-fold in a sub scanning direction resolution of the multilevel pixel information, wherein N is a positive integer, so that the N times exposures corresponds to an exposure for one pixel in the original resolution. The switch on/off statuses of the binary light source are controlled in the N times exposures for each pixel, on the basis of lighting rate information for converting the multilevel scales into a lighting rate in the N times exposures.Type: ApplicationFiled: September 2, 2011Publication date: March 8, 2012Inventors: Izumi KINOSHITA, Kunihiro Komai, Tatsuya Miyadera, Yoshinori Shirasaki, Takuhei Yokoyama, Takeshi Shikama, Akinori Yamaguchi
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Publication number: 20100149684Abstract: A data-storage device with a security function for user data stored in a data-storage medium. The data-storage device includes: the data-storage medium for storing data; an authentication processing section for performing an authentication process with a key obtained from a host; an error correction circuit for performing error correction in reading data at an address designated by a read command from a host which has been recognized as an authorized user for analysis access by the authentication processing section; and an analysis processing section for generating data indicating the positions of the error correction and transferring the data to the host.Type: ApplicationFiled: December 16, 2009Publication date: June 17, 2010Inventors: Akira KOJIMA, Yoshiju Watanabe, Takeshi Shikama, Masatoshi Nishina
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Patent number: 7607039Abstract: Embodiments of the invention improve the security of data written on a magnetic disk by performing re-allocation processing starting from a sector whose defect is large in automatic re-allocation processing. According to one embodiment of the present invention, after the reliability of each of data sectors that have been read out from a magnetic disk according to a read command is determined, re-allocation processing on the data sectors is performed in the order of increasing reliability. As a result, within a limited period of time, it is possible to replace by priority a data sector where there is a high possibility that data recovery will be unable to be achieved. This makes it possible to increase the security of data and the reliability of the HDD. The reliability of each data sector is determined on the basis of the number of bytes corrected by ECC.Type: GrantFiled: March 24, 2006Date of Patent: October 20, 2009Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Takeshi Shikama, Eiji Hagi, Mutsuya Hida, Hisatoshi Iwata