# US 2014/0153010 A1 · Optical-writing control device, image forming apparatus, and method of controlling optical writing device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0153010 A1 - Document ID: US20140153010A1 - Status: Published application - Kind: A1 - Application number: 14/086,266 - Filed: 2013-11-21 - Published: 2014-06-05 - Earliest claimed: 2012-11-30 - Assignees: Ricoh Company, Ltd. - Inventors: Tatsuya MIYADERA; MASAYUKI HAYASHI; MOTOHIRO KAWANABE; YOSHINORI SHIRASAKI; MASATOSHI MURAKAMI - Web page: https://patentgrep.com/patent/US20140153010A1 ## CPC - H04N 1/00246: {with an optical device, e.g. an optical viewing aid} - G03G 15/0189: {primary transfer to an intermediate transfer belt (G03G15/0184 takes precedence)} - G03G 15/5058: {using a test patch} - H04N 1/02815: {Means for illuminating the original, not specific to a particular type of pick-up head} - G03G 2215/0161: Generation of registration marks - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract An optical-writing control device calculates correction values for use in correcting a transfer position at which developing-agent images are to be transferred onto a sheet, and overlaying positions at which the developing-agent images are to be overlaid, based on a detection signal output from a sensor upon detection of a correction pattern for use in correcting the transfer position and a correction pattern for use in correcting the overlaying positions. A timing of detecting the pattern for use in correcting the overlaying positions is determined based on a correction value calculated based on the detection signal output upon detection of the pattern for use in correcting the transfer position. The pattern for use in correcting the transfer position is caused to have a width, in the main-scanning direction, that is wider than the width in the main-scanning direction of the pattern for use in correcting the overlaying positions. ## Claims ### Claim 1 An optical-writing control device that controls a plurality of light sources to form electrostatic latent images on a plurality of photosensitive elements, the light sources and the photosensitive elements being provided on a per-color basis of different colors, the optical-writing control device comprising: a light-emission control unit that controls each of the plurality of light sources based on information on pixels constituting an image to be formed, thereby exposing each of the plurality of photosensitive elements to light; a detection-signal acquiring unit that acquires a detection signal output from a sensor on a conveying path where developing-agent images obtained by developing the electrostatic latent images formed on the photosensitive elements using developing agents of the different colors are transferred and conveyed; and a correction-value calculating unit that calculates correction values for use in correcting a transfer position at which the developing-agent images are to be transferred onto a sheet, overlaying positions at which the developing-agent images of the different colors are to be overlaid on one another, and densities of the developing-agent images based on the detection signal output from the sensor upon detection of a correction pattern for use in correcting the transfer position, a correction pattern for use in correcting the overlaying positions, and a correction patter for use in correcting the densities, wherein the detection-signal acquiring unit determines a timing of detecting the pattern for use in correcting the overlaying positions and a timing of detecting the pattern for use in correcting the densities based on a correction value calculated based on the detection signal output upon detection of the pattern for use in correcting the transfer position, and the light-emission control unit controls light emission from each of the plurality of light sources so as to cause the pattern for use in correcting the overlaying positions to have a width, in a main-scanning direction, that depends on a width in the main-scanning direction of a detection area of the sensor, and controls light emission from each of the light sources so as to cause the pattern for use in correcting the transfer position to have a width, in the main-scanning direction, that is wider than the width in the main-scanning direction of the pattern for use in correcting the overlaying positions. ### Claim 2 (depends on 1) The optical-writing control device according to claim 1, wherein the light-emission control unit controls light emission from each of the plurality of light sources so that the pattern for use in correcting the overlaying positions is repeatedly drawn a plurality of times. ### Claim 3 (depends on 2) The optical-writing control device according to claim 2, wherein during a period when the light-emission control unit controls light emission from each of the plurality of light sources so that the pattern for use in correcting the overlaying positions is repeatedly drawn the plurality of times, the light-emission control unit corrects a parameter for use in controlling light emission from each of the plurality of light sources based on a correction value generated by detecting the already-drawn pattern. ### Claim 4 An image forming apparatus comprising an optical-writing control device that controls a plurality of light sources to form electrostatic latent images on a plurality of photosensitive elements, the light sources and the photosensitive elements being provided on a per-color basis of different colors, the optical-writing control device comprising: a light-emission control unit that controls each of the plurality of light sources based on information on pixels constituting an image to be formed, thereby exposing each of the plurality of photosensitive elements to light; a detection-signal acquiring unit that acquires a detection signal output from a sensor on a conveying path where developing-agent images obtained by developing the electrostatic latent images formed on the photosensitive elements using developing agents of the different colors are transferred and conveyed; and a correction-value calculating unit that calculates correction values for use in correcting a transfer position at which the developing-agent images are to be transferred onto a sheet, overlaying positions at which the developing-agent images of the different colors are to be overlaid on one another, and densities of the developing-agent images based on the detection signal output from the sensor upon detection of a correction pattern for use in correcting the transfer position, a correction pattern for use in correcting the overlaying positions, and a correction patter for use in correcting the densities, wherein the detection-signal acquiring unit determines a timing of detecting the pattern for use in correcting the overlaying positions and a timing of detecting the pattern for use in correcting the densities based on a correction value calculated based on the detection signal output upon detection of the pattern for use in correcting the transfer position, and the light-emission control unit controls light emission from each of the plurality of light sources so as to cause the pattern for use in correcting the overlaying positions to have a width, in a main-scanning direction, that depends on a width in the main-scanning direction of a detection area of the sensor, and controls light emission from each of the light sources so as to cause the pattern for use in correcting the transfer position to have a width, in the main-scanning direction, that is wider than the width in the main-scanning direction of the pattern for use in correcting the overlaying positions. ### Claim 5 A method of controlling an optical-writing control device that controls a plurality of light sources to form electrostatic latent images on a plurality of photosensitive elements, the light sources and the photosensitive elements being provided on a per-color basis of different colors, the optical-writing control device including a light-emission control unit that controls each of the plurality of light sources based on information on pixels constituting an image to be formed, thereby exposing each of the plurality of photosensitive elements to light, a detection-signal acquiring unit that acquires a detection signal output from a sensor on a conveying path where developing-agent images obtained by developing the electrostatic latent images formed on the photosensitive elements using developing agents of the different colors are transferred and conveyed, and a correction-value calculating unit that calculates correction values for use in correcting a transfer position at which the developing-agent images are to be transferred onto the sheet, overlaying positions at which the developing-agent images of the different colors are to be overlaid on one another, and densities of the developing-agent images based on detection signals output from the sensor upon detection of a correction pattern for use in correcting the transfer position, a correction pattern for use in correcting the overlaying positions, and a correction patter for use in correcting the densities, the method comprising: controlling light emission from each of the plurality of light sources so as to cause the pattern for use in correcting the overlaying positions to have a width, in main-scanning direction, that depends on a width in the main-scanning direction of a detection area of the sensor; controlling light emission from each of the light sources so as to cause the pattern for use in correcting the transfer position to have a width, in the main-scanning direction, that is wider than the width in the main-scanning direction of the pattern for use in correcting the overlaying positions; and determining a timing of detecting the pattern for use in correcting the overlaying positions and a timing of detecting the pattern for use in correcting the densities based on a correction value calculated based on the detection signal output upon detection of the pattern for use in correcting the transfer position.