An optical scanner includes a light source, an optical coupler, an optical line image unit, a deflector, and an optical scanning unit. The optical scanning unit includes scanning lenses that guide the beams to a surface to be scanned. A surface on the deflector side of the scanning lens closest to a deflection reflecting surface has a negative power in a vertical scanning direction, and is a special toric surface in which a radius of curvature in a vertical scanning changes from an optical axis of the lens surface toward a periphery of the horizontal scanning direction. An F number of the beams toward the surface to be scanned of the scanning lens in the vertical scanning direction is larger in a peripheral part than in a central part in an effective scanning width.

Optical scanner and image forming apparatus

Real-world incentives offered to virtual world participants

A common photodetecting unit detects a plurality of beams scanned by a plurality of polyhedral reflection mirrors provided in a multiple stages with a common rotation axis, and generates a synchronization detection signal based on detected beams. The reflection mirrors make a predetermined angle θ1 in a direction of rotation of the reflection mirrors. When time between two consecutive synchronization detection signals on a time line generated by the common photodetecting unit is ti, where i is a positive integer equal to or smaller than number of split beams, at least one of ti is different from others.

Optical scanning device and image forming apparatus

The invention provides an image display device that has an especially satisfactory display quality for animated images, and sufficiently suppresses the irregularities of display quality among pixels. The image display device includes a light emitting drive means that drives a light emitting means, based on an analog display signal inputted to the pixels, and a light emitting control switch for controlling a light-on or light-off of the light emitting means on one end of the light emitting drive means in each pixel.

Image Display Device

The present invention is characterized in that: a demanded printing-job is accepted at a printing-job accepting unit, and a printing executing unit executes printing according to the accepted printing-job so as to produce an output sheet onto a discharge tray; an output-sheet detecting unit detects the presence of a printed output-sheet on the discharge tray; if the removal of discharged sheets from the discharge tray is detected, a printed-sheet mixture determining unit determines the possibility that sheets printed corresponding to a plurality of demands are mixed among the removed output-sheets; and if it is determined the possibility that sheets printed corresponding to a plurality of the demands are mixed among the output-sheets, warning information is produced by a warning voice producing unit.

Image-forming apparatus and image-forming method

A pixel clock generating apparatus comprises a data offset circuit and a pixel generator. The data offset circuit defines multiple data blocks, each data block consisting of a predetermined number of successive clocks, and produces phase data for each data block. The phase data represents an amount and a direction of phase shift to be carried out for a certain clock in each data block. The pixel generator receives the phase data from the data offset circuit and generates a phase-shifted pixel clock a predetermined number of times in each data block based on the phase data.

Pixel clock generating apparatus, optical writing apparatus using a pixel clock, imaging apparatus, and method for generating pixel clocks

A pixel clock pulse generating apparatus for use in an image forming apparatus includes high frequency clock pulse and pixel clock pulse generators. The high frequency clock pulse generator generates relatively high frequency clock pulses. The pixel clock pulse generator generates pixel clock pulses based on the phase data for instructing a transition time of pixel clock pulses and the high frequency clock pulses.

Method and apparatus for image forming capable of effectively generating pixel clock pulses

A laser driver circuit includes a biasing current source, a threshold current source, and a modulation current source, wherein the threshold current source produces a threshold current in response to an input signal with an interval exceeding an interval of a modulation current such that said interval of the threshold current includes the interval of said modulation current. The laser driver circuit drives the laser diode by a sum of a continuous bias current, the threshold current and the modulation current.

Laser driver circuit

An optical scan device having an optical deflector reflecting a light beam from a light beam source so as to deflect the light beam and having a surface to be scanned on which information is written such that the light beam deflected by the deflector scans the surface is disclosed. Optical detectors are arranged at least in two locations, a start side of writing and an end side of writing, which locations are outside an effective writing area. A measuring part measures a scan time required by the light beam deflected by the optical deflector to scan a range between the optical detectors. A correcting part corrects each dot position of image data in the effective writing area to an arbitrary position based on a variation amount of the measured scan time.

Image forming method, image forming apparatus, optical scan device, and image forming apparatus using the same

A pixel clock generation apparatus includes a detector detecting a time interval between two horizontal synchronization signals. A comparing part compares the time interval detected by the detector and a target value, and outputs the difference. A phase shift data generation part stores one or more lookup tables each storing a pattern of phase shift data for controlling a phase shift amount of a pixel clock, and reads and outputs the phase shift data from the lookup table based on the difference that is output from the comparing part. A high frequency clock generation part generates a high frequency clock. A pixel clock generation part generates the pixel clock whose phase is controlled in accordance with the phase shift data based on the high frequency clock.

Pixel clock generation apparatus, pixel clock generation method, and image forming apparatus capable of correcting main scan dot position shift with a high degree of accuracy

Yasuhiro Nihei

Papers

Pixel clock generating apparatus, optical writing apparatus using a pixel clock, imaging apparatus, and method for generating pixel clocks

Method and apparatus for image forming capable of effectively generating pixel clock pulses

Laser driver circuit

Image forming method, image forming apparatus, optical scan device, and image forming apparatus using the same

Pixel clock generation apparatus, pixel clock generation method, and image forming apparatus capable of correcting main scan dot position shift with a high degree of accuracy