| Patent application number | Description | Published |
|---|
| 20080292342 | METHOD AND APPARATUS FOR FORMING IMAGE - In an image forming apparatus, a separating unit separates each laser beam into a first laser beam used for measuring light intensity and a second laser beam used for scanning a photosensitive element, a photoelectric converting unit measures a light intensity of each of the first laser beams and outputs a voltage indicative of the light intensity. A control unit controls a light intensity of each of the laser beams based on a common drive current and a corresponding one of a current correction value, which is set by each of the laser beams to correct a light intensity of a corresponding one of the laser beams based on a corresponding one of the voltages output by the photoelectric converting unit. | 11-27-2008 |
| 20090190943 | METHOD AND APPARATUS FOR FORMING IMAGE - An image forming apparatus includes a light source that emits a laser beam; a separating unit that separates the laser beam emitted from the light source into a first laser beam for measuring a light intensity and a second laser beam for scanning a photosensitive element to form image data; a first photoelectric converting unit that measures a light intensity of the first laser beam, and outputs a first voltage depending on the light intensity of the first laser beam; a second photoelectric converting unit that measures a light intensity of the second laser beam, and outputs a second voltage depending on the light intensity of the second laser beam; and a control unit that executes a first light-intensity correction for correcting the light intensity of the second laser beam per scan by each scanning line and a second light-intensity correction for adjusting a performance in forming the image data based on a current correction value for correcting a light intensity of the laser beam based on the first voltage and the second voltage and a drive current preliminarily-set with respect to the laser beam to cause the light source to emit the laser beam. | 07-30-2009 |
| 20100066799 | METHOD AND APPARATUS FOR FORMING IMAGE - An image forming apparatus includes a light source; a separating unit that separates a laser beam emitted from the light source into a first laser beam and a second laser beam; a first photoelectric converting unit that measures a light intensity of the first laser beam and outputs a first voltage depending on the light intensity of the first laser beam; a second photoelectric converting unit that measures a light intensity of the second laser beam, and outputs a second voltage depending on the light intensity of the second laser beam; and a control unit that executes a first light-intensity correction for correcting the light intensity of the second laser beam based on a current correction value and a drive current. The current correction value being a value used for correcting a light intensity of the laser beam based on the first voltage and the second voltage, and the drive current being a current preliminarily-set with respect to the laser beam to cause the light source to emit the laser beam. | 03-18-2010 |
| 20100150591 | IMAGE FORMING APPARATUS AND IMAGE FORMING METHOD - A first beam splitter splits each laser beam into a first beam and a second beam. A deflecting unit deflects a direction of the second beam. A second beam splitter splits the second beam into multiple split beams. A first photoelectric converting unit measures intensity of the first beam and outputs first voltage. A second photoelectric converting unit measures intensity of each split beam and outputs second voltage. A control unit updates a driving-current correction value using the first voltage and the second voltage, corrects a driving current, and controls intensity of the laser beam based on corrected driving current. | 06-17-2010 |
| 20110001788 | IMAGE FORMING APPARATUS AND LIGHT INTENSITY CONTROL METHOD - An image forming apparatus includes a light source that outputs a plurality of laser beams and a control unit that adjusts the light intensity of each of the laser beams. The control unit calculates a correction value so that, when the laser beam is driven by a control value calculated by correcting a common control value using the correction value and adding a threshold to the corrected control value, the light intensity of the laser beam is equal to a target light intensity. The threshold is calculated so that, when the laser beam is driven by a control value calculated by multiplying the corrected control value by a predetermined factor, and adding the threshold to the multiplied control value, the light intensity of the laser beam is equal to the target light intensity multiplied by the predetermined factor. | 01-06-2011 |
| 20110032323 | IMAGE FORMING APPARATUS, LIGHT-INTENSITY CORRECTION METHOD, AND COMPUTER PROGRAM PRODUCT - An image forming apparatus includes a light source that emits light beam; an illumination-current generating unit that generates an illumination current that causes the light source to emit the light beam; a deflecting optical unit, thereby forming a light spot and scanning the scanned surface; a detecting unit that detects a scanning position of the light spot on the scanned surface; a control unit that calculates a relation between a value of the illumination current and an intensity of light based on a plurality of intensities of emitted light, each intensity of the plurality of intensities being close to or equal to a prescribed light intensity, and causes the illumination-current generating unit to generate the illumination current based on the relation. | 02-10-2011 |
| 20110043594 | OPTICAL WRITING DEVICE AND OPTICAL WRITING METHOD - An optical writing device includes a light source that emits multiple laser beams; a separating unit that separates each of the multiple laser beams into a monitor beam and a scanning beam; a photoelectric converting element | 02-24-2011 |
| 20120007933 | OPTICAL DEVICE, CONTROL METHOD FOR THE SAME, AND IMAGE FORMING APPARATUS - An optical device includes: a light source including a plurality of light emitting spots that output laser beams, respectively; a separating unit that separates each of the laser beams output from the plurality of light emitting spots into a monitor beam and a scanning beam; a light-quantity measuring unit that measures a light quantity of the monitor beam; a storage unit in which respective drive currents with which the plurality of light emitting spots of the light source output a prescribed light quantity of laser beams are stored in advance; a light-source control unit that drives the light source with the drive currents stored in the storage unit and causes the plurality of light emitting spots to output the laser beams; and a determining unit that determines whether the light source operates properly on the basis of the light quantity measured by the light-quantity measuring unit. | 01-12-2012 |
