Abstract: An image forming apparatus includes: a photosensitive member; an intermediate transferring member to which an image formed on the photosensitive member is transferred; a press/release operation controlling section for controlling a pressing of the intermediate transferring member to the photosensitive member and for controlling a release of the pressing; a rotational actuation controlling section for controlling a rotational actuation of the photosensitive member; a judging section for judging a finish of a pressing operation carried out by the press/release operation controlling section; and a start timing controlling section for starting a control for the rotational actuation of the photosensitive member when the judging section judges the finish of the pressing operation by the rotational actuation controlling section.

Abstract: An image forming apparatus comprises: a photosensitive member; an intermediate transferring member to which an image formed on the photosensitive member is transferred; a press/release operation controlling section for controlling a pressing of the intermediate transferring member to the photosensitive member and for controlling a release of the pressing; a rotational actuation controlling section for controlling a rotational actuation of the photosensitive member; a judging section for judging a finish of a pressing operation carried out by the press/release operation controlling section; and a start timing controlling section for starting a control for the rotational actuation of the photosensitive member when the judging section judges the finish of the pressing operation by the rotational actuation controlling section.

Abstract: In an image forming apparatus for forming a color image by superposing component color images, a control device obtains position data representing a forming position of each of plural registration mark images for the component color images with respect to a positional reference value arbitrarily determined, divides the position data into each of a unit reference range representing a range in which one mark image is formed, converts the position data divided for each unit reference range into those based on respective reference values representing the front edge of the unit reference ranges, extracts the position data representing ranges common to the mutually overlapping ranges each of which is represented by a couple of position data corresponding to the rising and falling edges of a passage timing pulse as read position data of the mark image of the component color, and calculates the amounts of positional deviations of the component color images from one another on the basis of the position data extracted.

Abstract: An image forming apparatus having: a plurality of scanners, each of the scanners having a rotary polygonal mirror; a position detecting section for generating an image start reference signal in a main scanning direction; a PLL control section for controlling a rotation number of the mirror on a basis of a reference frequency signal of the mirror and a pulse signal generated per one rotation of the mirror; and a phase control section for detecting phase difference of each mirror on the basis of the image start reference signal in the main scanning direction in the plurality of the scanners, controlling a phase of the reference frequency signal of each mirror, and correcting image deviation in a sub-scanning direction of an image formed by the plurality of the scanners.

Abstract: There is described a duplex image-forming apparatus having a function of forming images onto both sides of a transfer material. The apparatus includes an image-forming section to respectively form an obverse-side image and a reverse-side image on a photoreceptor element by scanning a light beam, modulated with image signals based on pixel-clock signals and reflected from a polygon mirror rotating at an operating velocity based on polygon-clock signals; a transferring section to transfer said obverse-side image and said reverse-side image onto both surfaces of said recording sheet; a fixing section to fix the images onto both surfaces of said recording sheet; and a clock-frequency changing section to change a pixel-clock frequency, and a polygon-clock frequency, corresponding to a degree of shrinkage of said recording sheet caused by a fixing operation performed in said fixing section, at a transition time of an image-forming operation from one side to another side.

Abstract: An apparatus for scanning with multiple beams emitted from a semiconductor laser by a polygonal mirror, wherein an image is written for each scanning line by each beam of the multiple beams. The apparatus includes an automatic light amount control circuit having: (i) a light amount detecting circuit to detect a light amount of each beam for each scanning line, and (ii) a sampling/holding circuit to sample and hold a control voltage corresponding to the detected light amount of each beam for each scanning line. The automatic light amount control circuit controls the semiconductor laser based on the control voltage held by the sampling/holding circuit so as to control the light amount of each beam to be a predetermined light amount for each scanning line. The apparatus also includes a synchronization control circuit having an index sensor and a light receiving section on which each beam passes.

Abstract: In an image forming apparatus for simultaneously recording plural image lines on a recording medium by scanning simultaneously with plural light beams along parallel scanning lines in a primary scanning direction, two light beam detectors each having a starting-side are arranged in such a way that the starting-sides are not in parallel to each other so that the distance between the starting-sides differs depending on the scanning line. The difference in the distances of two light beams is measured, and the deviation between the two light beams is determined on the basis of the difference in the distances.

Abstract: A light beam deviation detecting device for detecting deviation of parallel light beams which simultaneously scan a photoreceptor in a primary scanning direction of the parallel light beams.

Abstract: In a method of writing a line of image on a photoreceptor with a laser beam in a main scanning direction, and of shifting in a sub-scanning direction to a next main-scanning line to write a next line of image, the method includes a step of shaping the laser beam spot on the photoreceptor to be in a form of an oval, said oval having a major axis that is in a direction that is in parallel to a main scanning direction of the laser.

Abstract: A document size detector for detecting a size of a document in use with a document scanner. The document size detector has an irradiator to irradiate the document with a light beam; a cover of the document; a receiver of the reflection light from the document and the cover; a converter to convert the reflection light to image signals; a detector to detect the shadow of the document on the cover in the image signals; and the determiner to determine the size of the document according to the detected shadow of the document.

Abstract: An image processing apparatus for processing an image signal, comprising a clock for generating a periodical clock signal, a pattern signal generator for generating 2N (where N is a positive integer) pattern signals, each of the pattern signals having a constant wave-form, a wave length of 2N times longer than that of the periodical clock signal and a phase difference 360/2N relative to another one of the pattern signals, a comparator for comparing the pattern signals with the image signal and for generating 2N of comparison signals, and a composition generator for combining said 2N comparison signals and for generating a pulse-duration modulated signal from the combined 2N comparison signals.

Abstract: A laser recording apparatus wherein a laser beam modulated in accordance with image signals and deflected by a deflector having a deflecting element in a predetermined direction scans a recording medium through a beam correcting lens system interposed between the deflector and the recording medium to write in the image signals on the recording medium. The deflecting element of the deflector is molded integrally of a frame, a reflecting mirror, a drive coil and a ligament. The deflecting element is made of a crystal base.

Abstract: An image recording apparatus having a beam scanning optical system using a deflector having a deflecting member, wherein a resilient member is interposed between the optical system including said deflector and an image forming portion. The resilient member is made of a viscous resilient elastomer of low hardness.

Abstract: A light beam recording system in which the beam is deflected after passage through a focusing element to scan a recording medium. An optical image surface correction system is employed between the deflector and recording medium for correction of the curvature of the field in the main scanning direction. The optical correction system includes an aspherical surface and deviation from a paraxial generating spherical surface to the aspherical surface.