Abstract: An optical device includes: an irradiation unit that irradiates a part of laser beams output from a light source as a scan beam onto an irradiation target and outputs the remaining part of the laser beams as a monitor beam used to monitor a light amount of the laser beams; a measurement unit that measures a light amount of the monitor beam; a storage unit that stores a plurality of measurement results obtained by the measurement unit when the laser beams are output in a plurality of different light amounts, and the plurality of the different light amounts associated with each other; and a prediction unit that predicts the light amount of the monitor beam relative to a reference light amount of the laser beam using a plurality of the light amounts stored in the storage unit and the measurement results corresponding to the plurality of the light amounts.

Abstract: A beam light scanning apparatus capable of reducing influences of variations in characteristics of circuits disposed in a signal path extending until a laser driver and speeding up image data transfer for scan and exposure. Data of each line is distributed by an image data I/F into data trains of two channels, i.e., an odd-numbered pixel train and an even-numbered pixel train. The data in the two-channel trains are written by writing units into a plurality of memories in parallel for each of the trains in response to a line sync signal. During the same processing cycle as that for the writing, the data are read out of the memories in parallel by reading units. The data of two channels are combined by a multiplexer into a data train in the original order of pixels in each line, and a driving signal based on the combined data is generated by a PWM. A laser is driven by the driving signal.

Abstract: 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, and a second laser beam. a first photoelectric converting unit, a second photoelectric converting unit, 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 a first voltage and a second voltage and a drive current preliminarily-set with respect to the laser beam to cause the light source to emit the laser beam.

Abstract: An electro-optical device includes a potential generating circuit that generates a first power supply potential and a second power supply potential that is different from the first power supply potential; a first signal processing circuit that selectively outputs one of a first high potential and a first low potential according to a data signal at one of at least three levels; a second signal processing circuit that selectively outputs one of a second high potential that is different from the first high potential and a second low potential that is different from the first low potential according to the data signal; a first current source that generates a first current in accordance with an output of the first signal processing circuit and the first power supply potential; a second current source that generates a second current in accordance with an output of the second signal processing circuit and the second power supply potential; and an electro-optical element that provides a tone level according to the fi

Abstract: An image forming apparatus is provided. The image forming apparatus includes a semiconductor laser that emits a laser beam, a light power of the laser beam being controllable by a current applied to the semiconductor laser; a scanner unit that exposes a photosensitive element by scanning the photosensitive element using the laser beam; a light power detection unit that detects a light power of the laser beam; a current control unit that controls the current applied to the laser based on the light power of the laser beam; a home position detection unit that detects whether the laser beam is positioned at a scan home position; and a continuous illumination unit that commences continuous illumination of the laser at a time which is prior to a forecast time at which the home position detection unit is forecast to detect the laser beam.

Abstract: A scanning optical apparatus includes, for example, a light source that outputs a light beam that has been pulse width modulated in accordance with input image data and a deflection unit that deflects the light beam so that the light beam scans the surface of an image carrier in the main scanning direction. The scanning optical apparatus furthermore includes a correction unit that corrects the pulse width and light amount applied to the light beam at each scanning position in the main scanning direction on the image carrier in accordance with focus error in the light beam at each scanning position.

Abstract: The present invention relates to a system for optically adjusting a computer-to-plate (CTP) imaging head which includes an a light source (104), optical fiber (124) for transmitting light emitted from the light source; an imaging lens (204) for focusing light emitted from a distal end of the optical fiber (128) on a substrate; wherein a portion of light striking the substrate is reflected back to the distal end of the optical fiber; a fiber optic coupler (116) in the optical fiber which transmits the reflected light to a light detector (112); wherein the light detector measures intensity of the reflected light; and a control unit configured to adjust the imaging head according to the intensity of the reflected light.

Abstract: 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.

Abstract: A light-amount detecting device includes: a light source which emits a light beam; a branching optical element which divides the light beam emitted from the light source into a first light beam traveling in a predetermined direction and a second light beam traveling in a direction different to the predetermined direction; a light-condensing element which condenses the second light beam; a light-receiving element having a light-receiving surface which receives the second light beam condensed by the light-condensing element; and a detector which detects a light-amount of the second light beam received by the light-receiving element, and at least one of a direction of reflected light of the second light beam reflected from the light-receiving surface of the light-receiving element and spread of the reflected light of the second light beam reflected from the light-receiving surface of the light-receiving element is adjusted to control a light-amount of the reflected light of the second light beam returning to the

Abstract: An optical scanning apparatus includes a light source and a structure for performing light-power control for the light source, the structure including a light-power-detection optical unit that establishes an optically conjugate relationship between a deflecting surface of a deflecting unit and a light-receiving surface of a light-power detector in a main-scanning plane. Accordingly, the storage time of a light beam on the light-power-detection optical unit is increased and variation in the power of light emitted by the light source due to heat generated by the light source and environmental variation is accurately detected.

Abstract: An apparatus for switching and controlling the intensity of a laser beam directed toward a beam detect sensor for an image forming device. A printing power reference signal and a beam detect power reference signal is selectively connected to a laser driver through a first switch. A printing power reference holding capacitor and a beam detect power reference holding capacitor is selectively connected to the laser driver through a second switch that is controlled in tandem with the first switch. During each scan cycle, the output laser power is monitored and used to adjust one of the two holding capacitors based such that both the printing power and the beam detect power have a controlled reference.

Abstract: Disclosed an image forming apparatus equipped with an exposure section including a plurality of LED elements, the apparatus forming an electrostatic latent image on a photosensitive body with the exposure section, the apparatus including: an RFID tag provided in the exposure section, the RFID tag including a light quantity correction data storing section and a communication section to perform wireless communication; an RFID reader/writer to perform the wireless communication with the RFID tag; a control section to allow the RFID reader/writer to perform the wireless communication with the RFID tag so as to read or write the light quantity correction data from/to the light quantity correction data storing section of the RFID tag during a period when no processing related to the image data is being performed; and a storage section to store the read light quantity correction data.

Abstract: An optical scanning apparatus controls an output of a light source for forming an electrostatic latent image on an image carrier. The optical scanning apparatus includes a correction amount control unit configured to variably control a light quantity correction amount of the light source according to a scanning position on the image carrier during one scanning operation with a beam generated from the light source, an output signal level changing unit configured to change a level of an output signal from the correction amount control unit, and a light quantity control unit configured to control a light quantity of the light source according to the scanning position based on a signal from the output signal level changing unit.

Abstract: Disclosed is an evaluation device of an optical writing device, comprising: the optical writing device; a light reception section; a drive section; and a control section to light each light emitting element in a previously set lighting pattern based on a light amount; to drive the drive section to move the light reception section to a position opposite to the light emitting element to be lit; to calculate characteristic data based on a light amount value of the light received by the light reception section; to calculate a first calculation value based on the characteristic data for each light emitting element; to calculate a second calculation value different from the first calculation value based on the characteristic data; to calculate a third calculation value based on the first calculation value and the second calculation value; and to instruct the display section to display the third calculation value.

Abstract: When a position detector detects that the position of a spot on a projection plane designates a non-projection region, the level of a driving signal of a laser is corrected. Specifically, the correlation between the quantity of laser light detected by a light-receiving portion and the level of the driving signal of the laser in accordance with prescribed data is detected. Then, the characteristic value of the laser indicated by the detected correlation is compared with the characteristic value at room temperature stored beforehand to indicate the correlation between the quantity of light emitted by the laser at room temperature and the level of the driving signal. Then, based on the comparison result, the level of the driving signal of the laser in accordance with image data is corrected.

Abstract: A light-emitting device includes: light-emitting elements whose luminous energy is controlled according to a current value and a pulse width of a driving signal; a storage unit that stores first and second coefficients for every light-emitting element; a pulse width determining unit that determines the pulse width of the driving signal supplied to each light-emitting element on the basis of the first coefficient, a current value determining unit that determines a current value of the driving signal supplied to each light-emitting element on the basis of the second coefficient, a driving unit that supplies the driving signal having the current value determined by the current value determining unit within the determined pulse width determined, to the light-emitting element, and a coefficient determining unit that calculates the first coefficient based on target values of a light amount and first peak light amounts of one of the light-emitting elements, and calculates the second coefficient.

Abstract: An image forming apparatus includes an optical scanning device that scans a scan area on an image carrier with light flux containing image information and writes the image information onto an image area in the scan area. In the optical scanning device, a first light receiving unit receives light flux emitted from a light source and reflected by a reflecting optical unit; a second light receiving unit receives light flux that passes through an aperture of the reflecting optical unit, is deflected by a deflecting unit, and heads for outside the image area within the scan area; and a control unit controls a drive signal of the light source based on signals output from the first and second light receiving units.

Abstract: Positioning displacement characteristics of each of scanning beams are obtained in advance. The positioning displacement characteristics is indicative of a relation between temperature and a displacement amount by which each of the scanning beams is displaced in a sub-scanning direction. A displacement control is performed based on the positioning displacement characteristics by shifting the positioning displacement characteristics in a direction opposite to that of a trend of the positioning displacement characteristics within a pixel pitch.

Abstract: At least one light emission array includes a plurality of light emitting elements arrayed in a first direction. Each of the light emitting elements is an organic electroluminescence element. A monitor quantitatively monitors a light emitting state of at least one of the light emitting elements to obtain a monitored amount. A comparator compares the monitored amount and a reference amount. A controller performs a constant current control with respect to at least one of the light emitting elements in accordance with a result of the comparison performed by the comparator.

Abstract: An apparatus includes an output voltage sensing unit, which senses an output voltage of a laser diode, which has been sampled during a power control period and transmits the sensed output voltage of the laser diode to an output voltage control unit; the output voltage control unit, which obtains an error voltage between a reference voltage and the sensed output voltage of the laser diode and generates a control voltage by proportionally integrating the error voltage; and an optical power compensation unit, which receives the control voltage and generates a compensated control voltage by compensating for an optical power deviation on the photosensitive drum during the printing period.

Abstract: An optical writing device includes: a light source including arrays arranged in a main scanning direction, each array including light-emitting elements arranged in the main scanning direction; a correction-value holding unit to hold, correspondingly with a light-emitting element, a correction value for changing timing to read out pixel data stored in an image storage unit; and a light-source drive unit to drive the light source by reading out the stored pixel data stored, according to the correction value. The correction-value holding unit includes a first area for holding a first correction value corresponding to a first light-emitting element located at an end of an array and a second area for holding a second correction value corresponding to a second light-emitting element other than the first light-emitting element, the first holding area being larger than the second holding area.

Abstract: A light emitting device includes a plurality of light emitting elements, a first storage unit that stores first correction values corresponding to the light emitting elements, a counting unit that counts the number of pixels whose gray-scale values designated by image data are within a predetermined range included in an image, a selection unit that selects a first mode or a second mode according to the relationship between the number counted by the counting unit and a threshold value, and a driving unit that drives the light emitting elements corresponding to the predetermined number of pixels to emit amounts of light corresponding to the first correction values when the first mode is selected by the selection unit, and drives the light emitting elements corresponding to the predetermined number of pixels to emit amounts of light corresponding to the image data when the second mode is selected by the selection unit.

Abstract: A light emitting device is provided with: a self-scanning light emitting element array that includes light emitting elements divided into plural groups, light-controlled for each of the groups, and arrayed in line; and a light-up controller that sets any one of a voltage and a current for light-up, in accordance with the number of light emitting elements intended to light up in each of the groups.

Abstract: A label pattern can be created on a label side of an optical disc under well focus control. An optical disc is first loaded in an optical disc drive with the label side thereof facing to an optical head of the optical disc drive. Then, the optical head is actuated along a focusing direction. Meanwhile, a light intensity addition signal is generated in response to optical signals reflected from the optical disc and received by the optical head. A closed-loop control operation of the optical head is performed according to the light intensity addition signal after the light intensity addition signal up-crosses a threshold. Then, a label pattern can be defined on the label side of the optical disc with the closed-loop control operation.

Abstract: A multi-beam image forming apparatus is disclosed in which a semiconductor laser array including plural semiconductor laser elements serves as an optical beam generation unit. The apparatus includes a printing ratio counting unit that counts printing ratios of the semiconductor laser elements in plural printing areas divided in a scanning direction based on image data transmitted from a host unit; and a light amount control unit that controls emission light amounts of the semiconductor laser elements based on a result from the printing ratio counting unit. The light amount control unit calculates droop correction values corresponding to the printing areas from the printing ratios of the semiconductor laser elements based on the printing ratios in the printing areas counted by the printing ratio counting unit so as to correct the light amounts of the semiconductor laser elements.

Abstract: A device is provided for setting up, adjusting, and/or controlling an apparatus that cyclically processes printed products. The device includes a lighting unit having at least one light source directed toward a processing area of the apparatus. The light source is controllable to selectively generate a continuous light or a flashing light synchronized with a processing cycle of the apparatus.

Abstract: An optical writing unit includes a light-emitting-element array in which a plurality of light emitting elements is arranged and an optical system that guides light flux emitted from the light emitting elements as a light spot. A result of comparison of a property value of the light emitting elements at a predetermined threshold in an exposure intensity distribution of the light emitting elements is within a preset range over an entire effective image area. An emission condition of the light emitting elements is set such that a fluctuation of amounts of exposure of the light emitting elements or a result of comparison of the amounts of exposure does not exceed a preset range over the entire effective image area.

Abstract: An image forming apparatus is provided with a modulator producing a modulated signal of a pulse width decided on given image data and a driver driving an optical generator such as laser to generate a light beam. The image forming apparatus is further provided with a scanner periodically scanning the light beam generated by the optical generator and a power detector detecting information indicative of a power of the light beam scanned by the scanner. A pulse width adjustor uses the information detected by the power detector, in order to adjust the pulse width of the light beam.

Abstract: Aspects of the disclosure provide a method for improving performance of a raster output scanner (ROS) system with a reduced cost. The method can include identifying a current mirror facet of a motor polygon assembly (MPA) including multiple mirror facets that each mirror facet has a reflectivity characteristic, determining a driving signal based on the reflectivity characteristic of the current mirror facet and a performance characteristic of a light source, and driving the light source based on the driving signal to emit light that is reflected by the MPA onto a photoreceptor.

Abstract: An exposure device for a non-impact printing apparatus which includes a plurality of light-emitting elements for forming images, a driver element for individually applying energy output levels to the light-emitting elements, lens for focusing the light emitted by the light-emitting elements, storage ability for storing a list of setting values for setting the energy output levels, wherein the list includes a plurality of series of setting values, each one of the series enabling to attribute at least one setting value to each one of the light-emitting elements, each one of the series being selectable as a function of an exposure device condition. A method is also provided for adjusting a non-impact printing apparatus which includes the step of selecting the most adequate series of setting values on the basis of an analysis of the optical density of printed images on a receiving medium.

Abstract: A method of adjusting an exposure device suited for an electrophotographic printer, the exposure device includes a plurality of light-emitting elements. The method includes the steps of energizing selected light-emitting elements according to a selection scheme, using a pre-determined energy level for energizing each selected light-emitting element and obtaining a corresponding exposure intensity distribution from the exposure device. The method further includes the steps of predicting a toner area coverage distribution, based on the obtained exposure intensity distribution and on a pre-established transfer function, obtaining an attribute of the predicted toner area coverage distribution and determining the setting values for the energy levels for energizing each selected light-emitting element such that the obtained attribute becomes a target attribute.

Abstract: A rotating deflection unit deflects a laser light emitted from a light-emitting element and performs a scanning with the laser light. A light-intensity detecting unit detects a light intensity of the laser light. A current control unit controls a current to be supplied to the light-emitting element so that the light intensity of the laser light reaches a target light intensity. An initializing unit determines an initial current value with which the target light intensity is obtained from the light-emitting element by eliminating an influence of a noise caused by a reflected light input into the light-intensity detecting unit from the rotating deflection unit.

Abstract: An optical scanning apparatus includes a plurality of light sources capable of emitting light. A detection unit detects a light quantity of the light emitted from the plurality of light sources. A control unit controls drive current of a light source designated as a control object based on a detection result obtained by the detection unit. The control unit controls the drive current based on an activation state of the light source designated as the control object and an activation state of a light source other than the control object.

Abstract: A light amount correcting method for a light emitting apparatus having a plurality of light emitting devices, includes: measuring light amount values of a plurality of the light emitting devices; extracting high frequency components from the measured light amount values; extracting low frequency components from the measured light amount values; calculating a first correction value for correcting a light amount value of a first light emitting device on the basis of the high frequency components; and correcting a second correction value for correcting the light amount value of the first light emitting device on the basis of the low frequency components; and correcting a light amount value of a second light emitting device such that it is included in both of the first allowable range and the second allowable range.

Abstract: An image forming apparatus includes light source having multiple light-emitting portions, rotating polygonal mirror which deflects a beam that is emitted from light source, and photosensitive member which is exposed by beams in an image period that is included in one scanning cycle of the beam. One scanning cycle of the beam includes an image period and a non-image period. This apparatus includes selection unit which selects one or more light-emitting portions to be used in image period from among multiple light-emitting portions, and driving unit which drives selected light-emitting portions to emit a beam in a non-image period that is immediately before image period. This apparatus further includes control unit which executes auto light power control for one or more light-emitting portions to be used in image period according to light power of beams detected by beam detection unit.

Abstract: A control method for controlling an optical head having a plurality of light emitting devices, includes: dividing the plurality of light emitting devices into a plurality of blocks by grouping adjacent light emitting devices of the plurality of light emitting devices; adjusting levels of driving signals supplied to the adjacent light emitting devices for each of the plurality of blocks so that emission luminances of the adjacent light emitting devices belonging to the each of the plurality of blocks become substantially equal to each other; and adjusting emission periods so that the equalized emission luminances of the plurality of blocks become substantially equal to each other.

Abstract: Adaptive correction techniques are disclosed that adaptively correct aberrations which may arise in systems such as laser printers, for example. For laser printers, calibration data processing results may be detected by a detector that is disposed to correspond physically to the recording medium so that characteristics such as position and intensity of a laser beam at the detector corresponds to that of a laser beam at the recording medium. In this way, aberrations in system performance may be adaptively corrected while the system is performing operational processes.

Abstract: A method and system for a color xerographic machine determines a lower bound for the ROS power levels so that color defects are not produced by light attenuation from one or more layers of toner particles on a latent image. The method computes a minimum ROS power level for the photoreceptor at its maximum and minimum charge levels. The minimum ROS power level is the level at which the discharge voltage does not drop beyond a maximum discharge voltage difference. The difference is related to a toner particle density that affects color reproduction. The minimum ROS power levels for the minimum and maximum photoreceptor charge levels are used to compute a functional relationship for minimum ROS power levels at other photoreceptor charge levels. Thereafter, the minimum ROS power level function may be used to compute minimum ROS power levels for other photoreceptor charge levels. The computed minimum ROS power levels may be used to control the power levels used during color reproduction performed by the machine.

Abstract: A drive signal for driving a semiconductor laser is generated on the basis of an image signal inputted in synchronism with a pixel clock. A bias signal to the semiconductor laser is generated at a timing earlier than the drive signal by a predetermined time. The bias signal is disabled in synchronism with the leading edge of the drive signal.

Abstract: An image forming apparatus forms an image by laser beams from a plurality of lasers. The image forming apparatus includes a light amount control circuit that detects displacement in a sub-scanning direction of the main scanning line of a laser beam from the predetermined laser, from a reference position. The apparatus decides an allotted amount of light for each of the plurality of lasers in accordance with the detected displacement and controls to drive each of the plurality of lasers in accordance with the decided allotted amount of light for each laser.

Abstract: An image recording apparatus (1) causes a recording head (20) to move through a distance corresponding to one half of the recording width of the recording head (20) in a sub-scanning direction each time a recording drum (10) makes one rotation. This, light emitting devices (23, 24) record two line data in advance, and thereafter following light emitting devices (21, 22) record the same line data repeatedly at the same position. This increases the energy of laser light beams given to a recording position on a printing plate (P) to accomplish the recording of an image with reliability. The recording speed is not extremely decreased because not all light emitting devices (21 to 24) are used to make the repeated recordings at the same position on the printing plate (P). Further, the construction of optical systems and driving systems in the image recording apparatus is not complicated.

Abstract: A light emitting device includes at least one light emitting unit, a switching unit, a comparator unit, a charge storage unit and a sensing unit. The switching unit is electrically connected to the light emitting unit. The comparator unit is electrically connected to the switching unit. The charge storage unit is electrically connected to the comparator unit and stores an amount of electric charges. The sensing unit has a light sensing circuit and is electrically connected to the charge storage unit. The light sensing circuit senses a light intensity of the light emitting unit. The sensing unit adjusts the amount of the electric charges and a voltage corresponding to the amount of the electric charges according to the light intensity. The comparator unit compares the voltage with a threshold voltage. The switching unit controls the light emitting unit in accordance with the result of the comparison.

Abstract: Laser beam scan line nonlinearity is compensated for by providing algorithms for generating linearity profiles which are used by a corresponding registration system in an electrophotographic device to determine the placement of Pels across a scan line.

Abstract: As a scanning light beam which is scanning and traveling away from an effective image region moves passed the location of a sensor, a horizontal synchronizing signal Hsync is obtained as a first detection signal. A deflection mirror surface turns around, thereby reversing the direction in which the scanning light beam scans. This scanning light beam therefore scans an effective image region IR, and a latent image forming operation using this scanning light beam is controlled based on the horizontal synchronizing signal Hsync. Hence, there is a relatively long period of time (T4+T5) since the horizontal synchronizing signal Hsync is obtained until formation of a latent image starts in accordance with the signal Hsync. This secures sufficient time for control of the latent image forming operation based on the horizontal synchronizing signal Hsync, and hence, realizes the latent image forming operation as desired during the time T6.

Abstract: A reference developing image is formed on a photoreceptor drum under an image forming condition measured in advance, and the density of this reference developing image is detected. A development bias voltage is corrected based on the detection result, and when a correction value of the development bias voltage exceeds a predetermined range, a reference output voltage of an ATC sensor for detecting the density of toner in a developing device is corrected based on the detected value of humidity around the developing device, the frequency of use of the apparatus, and the agitation stress of developer.

Abstract: The invention is directed to the provision of an exposure apparatus in which is stored an electric current value appropriately determined for supply to a light-emitting device, and a method for producing such an exposure apparatus. The production method according to the invention comprises the steps of supplying a reference electric current to the light-emitting device, and measuring the amount of light from each of the plurality of pixels of the light modulating device, determining whether a minimum value among the amounts of light measured from the plurality of pixels lies within a predetermined range, and determining the value of the electric current to be supplied to the light-emitting device so that the minimum value of the amounts of light falls within the predetermined range when the minimum value of the amounts of light is outside the predetermined range.

Abstract: An image forming apparatus includes a light source that emits a light beam in a main scanning direction according to image data to be used for image formation, a control unit that controls the light source, and detectors that detect the light beam. The main scanning direction is divided into areas and a cycle of a pixel clock is corrected in each area independently based on detection results of the detectors so as to correct an image position and image magnification.

Abstract: A disclosed image forming apparatus includes a laser array light source having plural laser light sources for generating plural laser beams; a photosensitive body having a surface on which an electrostatic latent image is formed by a surface potential changed by the plural laser beams emitted from the laser array light source; and a controller for controlling emission of the plural laser beams of the laser array light source. The controller sequentially turns off at least one of the plural laser beams when forming a continuous electrostatic latent image line on the photosensitive body by scanning the plural laser beams in a main scanning direction of the photosensitive body.

Abstract: An image data processing section subjects input image data to image processing, and outputs first to fourth image data. First to fourth pulse width modulation circuits are PWM circuits in each of which a plurality of reference positions are set in one pixel, and output pulses corresponding to the first to fourth image data. A synthesis circuit synthesizes the pulses output from the first to fourth pulse width modulation circuits, and a laser emits a light beam in accordance with the synthesized pulse.

Abstract: The image densities of images formed with a plurality of laser beams on the basis of image data are measured. The quantity of each of the plurality of laser beams is adjusted in accordance with the measurement result.