Abstract: A two-dimensional beam writing position detecting device for providing an optical system for scanning on a photoconductor by laser beams emitted from a semiconductor laser to form an electrostatic latent image and arranging a plurality of the laser beams in two dimensions and slantingly scanning each the laser beam for forming the electrostatic latent image on the photoconductor at a predetermined angle and detecting the laser beams for determining the first writing position on the photoconductor of the laser beams is characterized in that a longitudinal direction of a beam light receiving surface of the detecting device 1 inclines at the substantially same angle as the slant scanning angle with respect to the perpendicular of a scanning direction of the plural beams.

Abstract: The invention relates to a device with a detector element for receiving a light beam reflecting on an object, wherein means for detecting the light beam are provided in the detector element. The invention also relates to a method for distance measurement using said receiver device. A device for determining the distance between a vehicle and an obstacle or a vehicle driving ahead is already known as per DE 197 13 826 A1, wherein a pulsed laser beam serving as send signal scans line-by-line a two-dimensional area using a self-rotating polygonal mirror, wherein said polygonal mirror has a plurality of mirror surfaces that are bent at different angles. The pulse beam reflecting on the object is focused on a detector element by optical lenses.

Abstract: A scanning type optical device comprises one optical characteristics measuring unit per color. Each optical characteristics measuring unit further includes three units. The first unit is provided on a writing start side within a scanning region, the second unit is provided on the other end side within the scanning region, and the third unit is arranged substantially at the center in the scanning region. Laser beams emitted from each of four semiconductor lasers are modulated based on signals detected by the three units in such a manner that a difference between a real image height and an ideal image height is reduced over the entire scanning region.

Abstract: A system and method for measuring the profile of an external surface of a part is provided. The system includes a source of light that directs light onto a region of the external surface of the part. The system also includes a linear, light-sensitive sensor, and a lens used to image locations within the region onto the sensor. The source of light and the sensor are located substantially within the same plane such that the sensor detects substantially only light scattered, diffracted, or reflected from the region and travelling substantially within the plane. The system additionally includes a re-positionable mirror that re-directs the light emitted from the source of light to the plurality of locations within the region and re-directs light scattered, diffracted, or reflected from the plurality of locations within the region to the lens and the sensor.

Abstract: Disclosed is a scanning optical system that includes a laser source for emitting a laser beam, a scanning deflector that deflects the laser beam, an imaging optical system that converges the scanning laser beam onto an object surface, first and second mirrors that bend the optical path of the scanning laser beam. The first and second mirrors are movable to adjust the optical path length between the deflector and the object surface for changing a width of the scanning range on the object surface. Since the optical path length is adjusted by moving the first and second mirror, which changes the width of the scanning range, correcting the size error of the printed image. When the size error of the printed image is detected, an operator moves the first and second mirrors to correct it.

Abstract: Microarea light-emitting diodes, which have no variation in light output power the like due to mode-hopping, are used and changes in properties such as light output and the like due to generated heat are prevented. Pulses having a constant period and a substantially constant power are used, a number of the pulses within a period for forming an image corresponding to one pixel is determined on the basis of image data, and light beams emitted from the microarea light-emitting diodes are modulated by pulse signals including the determined pulses.

Abstract: A light scanning device of a laser printer to scan light to form a latent image on a photosensitive drum according to image data. The light scanning device includes a plurality of laser beam sources disposed to be parallel with each other, to emits laser beams having various wavelengths; a plurality of collimator lenses to transform the laser beam into parallel light; and a first optical output portion having a plurality of optical members to reflect or transmit the light output from each collimator lens through one surface, and reflect or transmit the reflected light through the other surface according to wavelength. Thus, a single output path is formed at an end-most portion thereof.

Abstract: A controller for an optical scanner includes a mirror angle detecting unit for detecting an angle of a mirror, a rotation shaft angle detecting unit for detecting an angle of the shaft, a current detecting unit for detecting a current supplied to a motor, and a torsional vibration stabilizing compensation unit for stabilizing a torsional vibration of the shaft, thereby a value subjected to a proportional compensation and a differential compensation by using a rotation shaft angle detected value and a value from the torsional vibration stabilizing compensation unit are negatively fed back to a value obtained by integrally compensating for a tracking error between the angle desired value and a mirror angle detection value to determine a current value to be supplied to the motor.

Abstract: To read an image with high resolution via a CCD linear sensor having a limited pixel count, an image reading apparatus includes: a CCD linear sensor having arranged in a main-scanning direction photoelectric conversion elements for receiving a light reflected from an original; a piezoelectric element for providing a relative displacement between a light receiving surface of the CCD linear sensor and an object's image formed on the light receiving surface, according to a predetermined oscillation function and in the main-scanning direction; and a sensor drive circuit timing the CCD linear sensor's charge accumulation. The sensor drive circuit uses a distance from a center of an amplitude of the relative displacement to the CCD linear sensor and a time period of charge accumulation by the CCD linear sensor to determine a time point to start charge accumulation.

Abstract: An image exposing apparatus for exposing an image onto a light sensitive material, is provided with a plurality of light beam emitting element arrays, each light beam emitting element array emitting aligned-light beams which are aligned in at least a single line; a light mixing device for mixing a plurality of aligned-light beams emitted from the plurality of light beam emitting element arrays and for emitting mixed-aligned-light beams which are aligned in the same line; a light receiving device located so as to receive the mixed-aligned-light beams at a position where the light sensitive material is exposed; and an adjusting device for adjusting a position of each of the plurality of light beam emitting element arrays based on a light receiving result by the light receiving means.

Abstract: The separation between the light source module for a film scanner and the protection window for pressing against the film document is minimized to increase light intensity by inserting low friction material between the scanning light source module and the protection window. The pressure is exerted by means of a spring or gravity.

Abstract: To provide a laser scanning control apparatus for driving a light source adapted to emit a laser beam in accordance with image data defined in pixels to scan an image bearing member in a main scanning direction with the laser beam emitted from the light source through a rotating polygon mirror, the laser scanning control apparatus being characterized by including a correction portion for, every one or more correction points on a main scanning line of the image bearing member to be scanned with the laser beam, extending the pixel length for each pixel located in the correction point concerned to thereby correct the scanning magnification of the main scanning line, and for changing the rotational speed of the rotating polygon mirror to correct the magnification in a sub scanning direction to thereby correct the output magnification.

Abstract: A combination shutter and attenuator disk assembly for use in an imaging apparatus includes a circular disk that has a circular attenuation portion which surrounds a rotational axis of the disk, and circular shutter portion that surrounds the circular attenuating portion. The circular attenuation portion is divided into at least a variety of attenuating sections. The assembly also includes a movement device that includes a shutter cylinder for linearly moving the disk between shuttered and attenuated positions, and a rotatable motor that is adapted to rotate the disk to a desired attenuation section of the disk.

Abstract: A method for determining a scan line error for a scan line, wherein the scan line is produced from one of a plurality of facets of a rotating reflector of a scanning device. The method comprises the steps of (a) determining a difference between a time of an occurrence of a point in a scan line produced from a first facet and a time of an occurrence of a point in a scan line produced from a second facet, and (b) determining from the difference, a scan line error for the scan line produced from the first facet.

Abstract: A device for remote detection of surface flaws in enclosed cavities that have been treated with a photoluminescent medium. The device has a non-rotating ultraviolet radiation source, an offset rotary drive means, a passive rotary scanning means that includes a plurality of lenses, reflectors and an optical filter, a non-rotating solid-state photodiode, and support electronic circuitry. Ultraviolet radiation from the illumination source is projected onto the test-part surface and causes dye penetrant that has been previously deposited onto the test-part surface to fluoresce at a different wavelength, thus revealing the presence of surface cracks and flaws. The receiving lenses capture the fluorescent light and project it onto the photodiode, which generates a series of electrical pulses that correspond to the presence of surface flaws. By encoding the linear and angular position of the scanning means, an accurate and quantitative map of the flaw pattern can be constructed.

Abstract: A scanning optical system includes first and a second lens elements, at least one of which is a plastic lens element. Each surface of the plastic lens element is an aspherical surface that is configured such that a shape in a main scanning plane is defined as a function of a distance, in the main scanning direction, from a surface reference axis thereof, and that a curvature in an auxiliary scanning plane which is perpendicular to the main scanning plane is defined as another function of a distance, in the main scanning direction, from the surface reference axis. At least one of the two surfaces of the plastic lens element are arranged such that the surface reference axis thereof is decentered from an axis of the beam in the auxiliary scanning direction.

Abstract: A device for treating a substrate with laser radiation is described. The device has a rotating polygon mirror with N reflecting surfaces which are used to direct a laser beam via a system of converting focusing lenses, whereby the focal planes of the lenses are located on a surface of the substrate. Active reflecting surfaces direct the laser beam onto the converging lens system, and subsequently on the substrate, while inactive reflecting surfaces have a different inclination to the active reflecting surfaces in relation to the converging lens system. The laser beam from the surfaces is directed onto an absorber. The large number of inactive reflecting surface helps to reduce serial hole density. When the laser is switched on and off while the inactive reflecting surfaces are being scanned, further reduction of serial hole density can be achieved.

Abstract: A multibeam scanner for scanning an image area with a plurality of laser beams, comprising a plurality of beam emitting points that emit a plurality of laser beams reaching the image area with respective time lags therebetween, a time lag determination unit that determines at least one of the time lags during a predetermined calculation time, a scan controller that controls the plurality of beam emitting points to emit the plurality of laser beams successively in the image area with the at least one of the time lags determined by the time lag determination unit. The multibeam scanner of the invention, comprises a photodetector that detects any one of the laser beams at a predetermined beam detection position. The time lag determination unit determines the time lag between the nth laser beam and the n+1th laser beam.

Abstract: A field emission electron source includes: a field emission array portion composed of an insulation layer with a plurality of apertures, which is formed on a substrate, an extraction electrode formed on the insulation layer, and a plurality of cathodes formed respectively on the substrate in the plurality of apertures; a cathode base for fixing the field emission array portion; and an electron lens portion composed of a plurality of electrode members having a function of accelerating and converging an electron beam emitted from the field emission array portion. An emission axis of the electron beam emitted from the field emission array portion has a predetermined angle with respect to an optical axis of the electron lens portion. Thus, the field emission array portion can be protected from impact caused by ions generated in the electron lens portion, thereby improving the life of a field emission electron source.

Abstract: An optical scanning device includes a plurality of optical scanning, units each including a light source emitting a light flux, a scanning input optical system directing the light flux emitted from the light source to a deflector. The deflector deflects the light flux so as to cause the light flux to scan a surface to be scanned. A scanning and imaging optical system condenses the light flux deflected by the deflector so as to form a beam spot thereof on the surface to be scanned. The optical scanning device scans the surface to be scanned continuously through coordinated movements of the plurality of optical scanning units, and the respective scanning and imaging optical systems of adjacent at least two of the plurality of optical scanning units have one lens in common.

Abstract: The invention relates to a method and a device for reading out radiation image information stored on an image medium (12). A scanning unit (10) has a laser (16) for scanning the image medium (12) with a readout light beam (22). The read/processing device (14) functions with two channels so that the luminescent light emitted by the image medium (12) during scanning and also the reflected read-out light are synchronously detected, evaluated and correlated. The digital luminescent light image values are corrected according to the digital reflection light values in order to better obtain the radiation image information.

Abstract: A method for determining a scan line error for a scan line, wherein the scan line is produced from one of a plurality of facets of a rotating reflector of a scanning device. The method comprises the steps of (a) determining a difference between a time of an occurrence of a point in a scan line produced from a first facet and a time of an occurrence of a point in a scan line produced from a second facet, and (b) determining from the difference, a scan line error for the scan line produced from the first facet.

Abstract: The invention is structured such as to improve a multi-beam exposure apparatus for scanning a plurality of beams, and provides an exposure apparatus in which no color shifting or no shading and no spread of a line is generated by reducing a mutual shifting of the respective beams so as to accurately overlap an image.

Abstract: A system and method for measuring the profile of an external surface of a part is provided. The system includes a source of light that directs light onto a region of the external surface of the part. The system also includes a linear, light-sensitive sensor, and a lens used to image locations within the region onto the sensor. The source of light and the sensor are located substantially within the same plane such that the sensor detects substantially only light scattered, diffracted, or reflected from the region and travelling substantially within the plane. The system additionally includes a re-positionable mirror that re-directs the light emitted from the source of light to the plurality of locations within the region and re-directs light scattered, diffracted, or reflected from the plurality of locations within the region to the lens and the sensor.

Abstract: The present invention provides a rotary laser irradiating system, which comprises a laser light source, a range-finding unit, a rotator for irradiating a laser beam from the laser light source and a range-finding light from the range-finding unit onto a reference plane by rotary irradiation, and scanning means for deflecting the laser beam from the laser light source on the reference plane.

Abstract: In a probe microscope 120 for causing a sample 112 and a tip portion 118a of a probe 118 on the sample side to approach each other, detecting an interaction between the sample 112 and the sample-side probe tip portion 118a, and obtaining surface information of the sample 112 from the interaction, the probe 118 being a flexible needle-like probe; the probe microscope 120 comprises vibrating means 122 capable of rotating the probe 118 while flexing the sample-side tip portion 118a thereof so as to draw a circle having a size corresponding to an increase and decrease in the interaction between the sample surface 112 and the tip portion 118a, and detecting means 124 for detecting the increase and decrease in the size of the circle drawn by the sample-side probe tip portion 118a due to the interaction and obtaining, from the increase and decrease in the size of the circle, information about the distance between the sample 112 and the sample-side probe tip portion 118a.

Abstract: Scan systems include at least one radiation source for directing at least one beam toward a scan-device system. The scan device system includes at least one scan device that reflects these beams as rotating scan beams which point to the optical aperture of a rotating optical system. The rotating optical system has at least one optical component selected from a group of reflectors and lenses, focuses the scan beams into radiation spots, and projects them onto a scanned surface as moving scan spots. Linear relative movement between the scanned surface and the rotating optical system produces an area scan of inner drum or planar surface.

Abstract: A scanning sensor system includes a light sensor and a scanning telescope having a first telescope subassembly and a second telescope subassembly. Each of the telescope subassemblies has a primary telescope mirror oriented to receive an incident light beam over an angular viewing range as the primary telescope mirror is rotated about a primary-mirror rotation axis, and at least one additional telescope mirror positioned to receive a reflected light beam from the primary telescope mirror. A primary mirror drive rotates the primary telescope mirrors about the primary-mirror rotation axis at a primary mirror angular instantaneous rate of rotation. A half-angle derotation mirror has a derotation-mirror axis parallel to the primary-mirror rotation axis. The half-angle derotation mirror is positioned to reflect light in the optical path when each primary telescope mirror is within the angular viewing range and to direct the reflected image along the optical path toward the sensor.

Abstract: A two-dimensional beam writing position detecting device for providing an optical system for scanning on a photoconductor by laser beams emitted from a semiconductor laser to form an electrostatic latent image and arranging a plurality of the laser beams in two dimensions and slantingly scanning each the laser beam for forming the electrostatic latent image on the photoconductor at a predetermined angle and detecting the laser beams for determining the first writing position on the photoconductor of the laser beams is characterized in that a longitudinal direction of a beam light receiving surface of the detecting device 1 inclines at the substantially same angle as the slant scanning angle with respect to the perpendicular of a scanning direction of the plural beams.

Abstract: A system and method for measuring the profile of an external surface of a part is provided. The system includes a source of light that directs light onto a region of the external surface of the part. The system also includes a linear, light-sensitive sensor, and a lens used to image locations within the region onto the sensor. The source of light and the sensor are located substantially within the same plane such that the sensor detects substantially only light scattered, diffracted, or reflected from the region and travelling substantially within the plane. The system additionally includes a re-positionable mirror that re-directs the light emitted from the source of light to the plurality of locations within the region and re-directs light scattered, diffracted, or reflected from the plurality of locations within the region to the lens and the sensor.

Abstract: An optical scanning system of a printer includes an optical scanning unit including a light source, a rotating polygonal mirror having a plurality of mirror surfaces for deflecting light emitted from the light source toward a photoreceptor web, and a driving source for driving the rotating polygonal mirror.

Abstract: The invention provides a device for linear scanning, including at least one reflecting element whereby an incident beam of light undergoes at least two reflections; at least one optical system comprising an objective capable of forming an image of an object, the objective, depending on the respective direction of the light beam, defining a pre-objective scanning space and a post-objective scanning space; a mounting structure for the at least one reflecting element; drive means for causing the mounting structure to perform a movement; and a light-detecting element for detecting the incident beam of light, or an element for producing light, wherein, with light-detecting, scanning takes place in the post-objective space, and with light-producing, scanning takes place in the pre-objective space.

Abstract: An optical scanning apparatus includes a light source for radiating a light beam, an optical scanning system for deflecting the light beam from the light source and condensing the light beam on a surface to be scanned, a detecting device for detecting an image forming state of the light beam scanned by the optical scanning system, and an adjusting mechanism for adjusting the focal position of the light beam on the surface to be scanned. The detecting device includes a very low cost detecting element that can accurately detect an image forming state of the light beam scanned by the optical scanning system independently in a main scanning direction and in a sub scanning direction. While the focal position of the light beam is changed continuously or at a predetermined pitch by the adjusting mechanism, the detecting device monitors the image forming state of the light beam and detects the location and vicinity of a light beam waist position relative to a desired position on the surface to be scanned.

Abstract: The digital laser image recorder includes a data manipulation and control system which may provide digital data to a digital light source for conversion to an analog modulated light beam. A scanner may also be provided to direct the light beam toward a writing surface which may be disposed on the interior of a rotatable cylinder. A film handling device operable to deliver sheet film to the writing surface may also deliver sheet film from the writing surface to an associated output tray after writing. In another embodiment, beam shaping optics may be provided to convert the analog modulated light beams to collimated beams of a predetermined size and circular distribution. The beam shaping optics may also incorporate a power control filter to control the intensity of the collimated beams. In yet another embodiment, a shutter may be provided.

Abstract: A light scanner includes a semiconductor laser, a polygon mirror, a first imaging optical system for guiding a light beam from the semiconductor laser to the deflection surface of the polygon mirror, a second imaging optical system of a single curved mirror for guiding the light beam from the polygon mirror to a photosensitive drum, and a photodiode for detecting the light beam scanned by the polygon mirror. The first imaging optical system, the polygon mirror, and the second imaging optical system are located at different positions in the sub-scanning direction so that the light beam from the first imaging optical system enters obliquely with respect to a plane containing the normal to the deflection surface of the polygon mirror and being parallel to the main scanning direction, and the light beam from the polygon mirror enters obliquely with respect to a plane containing the normal to the curved mirror at its vertex and being parallel to the main scanning direction (i.e., a Y-Z plane).

Abstract: A horizontal scanning device capable of scanning a bar code label on an underside or on a standing side wall of an article is revealed. The device is made of a source of laser light; a rotatably drivable polygonal mirror with mirror surfaces for distributing in scan lines the laser light transmitted by the laser source; a number of fixedly disposed mirrors for reflecting through a window the laser light beam distributed by the polygonal mirror, wherein the polygonal mirror has at least one mirror surface in co-action with a fixedly disposed mirror and at least one laser light beam is directed through the window at the article, which line extends for at least a moment substantially vertically to that window and the projection of which onto the article moves substantially in the plane perpendicular to that window and through that vertical line; and a detector for receiving light scattered by the code.

Abstract: Scanning is performed in a sub scan direction an image on a scan medium placed on a plane with a one-dimensional image sensor at a fixed position via a reflecting mirror rotatable around a fixed axis without causing a scan defect due to a change in the optical path length. An image light generating from an image on a scan medium is deflected by a reflecting mirror so at to form an image at a position of an image sensor via an image formation optical system. The image sensor reads a scan image as a one-dimensional main scan line and the reflecting mirror is rotated so at move a scan position in a sub scan direction. The rotation of this reflecting mirror is interlocked with displacement of the image formation optical system in an optical axis direction, thus enabling to prevent an image formation defect due to a change in the optical path length.

Abstract: A scanner, through which a document moves while being scanned by a moving beam of light, includes a wheel that rotates responsive to document movement. The wheel includes a multi-sectioned optical encoder upon which the scanning beam of light impinges when in a position at which it does not impinge upon the document. The scanner also includes an optical detector which receives light that is not absorbed by the optical encoder sections. Thus, the optical detector generates an electrical signal that indicates document movement speed. A preferred embodiment the scanner includes a pair of cup-shaped wheels one of which carries the optical encoder that encircles an inner surface of the wheel adjacent to a lip thereof. An axle, also included in the preferred embodiment, spans between, is coupled to, and supports the wheels for rotation in unison about a longitudinal axis parallel to the axle.

Abstract: Red, green and blue light beams from a light source portion travel via a first optical system and enter a reflecting surface of a rotating polygon mirror at different angles so as not to overlap each other. The rotating polygon mirror makes these light beams perform scanning when reflecting these light beams. The light beams for the scanning enter a second optical system at different angles and are led to different positions on an image display panel. The second optical system forms an image that is rotated by 90° from that on the rotating polygon mirror on the image display panel. On the image display panel, belt-like regions illuminated by the light beams of individual colors are formed in parallel with each other, and these illuminated regions are moved continuously by the scanning. Each pixel of the image display panel is driven by a signal corresponding to a color of light entering this pixel. A formed color image is magnified and projected by a projection optical system.

Abstract: A light scanning apparatus includes a deflector for deflecting a light beam emitted from a laser. A rotating reflector is provided in the deflector, and a reflecting surface is formed on the rotating reflector by cutting away a portion of the rotating reflector diagonally with respect to a plane perpendicular to the axis thereof. The light scanning apparatus further includes a control device for controlling a stopping position of the rotating reflector such that the rotating reflector stops rotating in a state in which the reflecting surface faces a predetermined direction. A magnet, an electromagnet, or a gear mechanism may be used as the control device.

Abstract: A galvano mirror system includes (1) a galvano mirror, (2) a mirror holder having a front portion to which the galvano mirror is mounted and a rear portion opposing to the front portion, (3) a stator which rotatably supports the mirror holder, (4) first and second reflecting surfaces provided to the rear portion of the mirror holder, and (5) first and second photo sensors provided to the stator. Each photo sensor includes a light-emitting device and a light-receiving device. A controller of the galvano mirror system detects the rotational position of the mirror holder according to on a difference in outputs of the light-receiving devices of the first and second photo sensors.

Abstract: A coupling lens couples a beam emitted from a light source. A light deflector deflects the beam from the coupling lens at a uniform angular velocity. A line-image imaging optical system is disposed between the coupling lens and light deflector, and causes the beam to image a line image long along main scanning directions on or in the vicinity of a deflection reflective surface of the light deflector. A scanning and imaging optical system causes the beam deflected by the light deflector to image a beam spot on a medium to be scanned. In an optical housing, the light source, coupling lens, light deflector, line-image imaging optical system and scanning and imaging optical system are disposed, and contained. A plurality of holding and fixing datums are provided for holding and fixing a light-source part including the light source and coupling lens is provided in at least one of the light-source part and optical housing.

Abstract: An optical system includes a curved window, an asymmetric, scoop-shaped optical corrector adjacent to a curved inner surface of the window, an optical train positioned such that the optical corrector lies between the curved window and the optical train, a movable optical train support upon which the optical train is mounted, and a sensor disposed to receive an optical ray passing sequentially through the window, the optical corrector, and the optical train. The optical corrector has an inner surface and an outer surface, at least one of which has a shape defined by an asymmetric polynomial.

Abstract: A scan systems include at least one radiation source for directing at least one beam toward a spinning scan device. The scan device reflects these beams as rotating scan beams to track rotating scan lenses without translation between the scan beams and the scan lenses. The rotating scan lenses focus the scan beams into radiation spots and project them onto a scanned surface as moving scan spots. Relative movement between the scanned surface and the scan lenses produces an inner drum area scan. According to another version the system includes at least one radiation source for directing at least one beam toward a spinning scan device. The scan device reflects these beams as rotating scan beams to track rotating reflectors. The reflectors direct the beams to rotating tracking lenses without translation between the beams and the lenses. The lenses focus the scan beams into spots and project these onto a scanned surface as moving spots.

Abstract: A light beam scanner unit includes a light beam generating unit for generating light beams at a fixed power, a polygon mirror for reflecting light beams generated from the light beam generating means toward a surface to be scanned, thereby scanning it, and a light beam power sensing unit for sensing light beam power for scanning a surface to be scanned with the polygon mirror. This light beam scanner unit further has a mirror contamination sensing unit for sensing contamination of the polygon mirror by comparing a sensing result obtained from the light beam power sensing unit when light beams are emitted by the light beam generating unit with a preset reference value.

Abstract: A galvano mirror system includes (1) a galvano mirror, (2) a mirror holder having a front portion to which the galvano mirror is mounted and a rear portion opposing to the front portion, (3) a stator which rotatably supports the mirror holder, (4) first and second reflecting surfaces provided to the rear portion of the mirror holder, and (5) first and second photo sensors provided to the stator. Each photo sensor includes a light-emitting device and a light-receiving device. A controller of the galvano mirror system detects the rotational position of the mirror holder according to on a difference in outputs of the light-receiving devices of the first and second photo sensors.

Abstract: An improved raster scanner, and electrostatographic printing machines which use such scanners, in which facet tracking is achieved by incorporating a semiconductor laser having an electronically tunable wavelength and a wavelength dispersive element which directs the laser beam onto the facets of a rotating polygon. The wavelength dispersive element is positioned, and the wavelength output from the laser is adjusted, such that as the polygon rotates the laser beam produces a spot on a facet which tracks the facet.

Abstract: An image forming apparatus which can reduce the appearance of a vertical regist shift in a multiple beam writing system. A time interval detector is provided and is configured to detect a time interval between a start signal for scanning in a sub-scanning direction and a synchronous signal for scanning in a scanning direction. Further, this time interval is compared with at least first and second threshold values. Writing by the multiple beam sources is then controlled based on the results of the comparison. By utilizing such an operation the appearance of a vertical regist shift can be reduced.

Abstract: A document transport for a scanner (100) has a flexible, elongated finger (226) disposed adjacent to a document (134), and a force applied to the finger (226) urges teeth (233) on the finger (226) into contact with the document (134) which urges the document (134) along a path through the scanner (100). A piezoelectric plate (222), which applies the force to the finger (226), requires only a small amount of electrical power. To traverse the scanner (100), a document (134) may also be manually fed along a guide (272). First and second speed-sensing detectors (276a and 276b), disposed along the path traversed by the document (134), permit the scanner (100) to determine a speed at which the manually fed document (134) traverses the scanner (100). To conserve electrical energy, the scanner (100) also includes a document-presence detector (274) for activating the scanner (100) when a document (134) to be scanned is present.

Abstract: An optical scanning system for a printer, for example, includes: an optical scanning unit for scanning light onto an image print region of a photosensitive belt; a photodetector disposed at an edge of the photosensitive belt for receiving the light emitted from the optical scanning unit, and for outputting a pulse signal in response to the received light; a belt position calculator for counting a hold time of the pulse signal output from the photodetector in order to calculate an edge point of the photosensitive belt; a memory for storing information about the delay time from an end point of the pulse signal to a point in time at which the optical scanning unit starts scanning light onto a start point of the image print region of the photosensitive belt; a delay time setting unit for accessing the memory in order to locate delay time information, corresponding to the edge point of the photosensitive belt, output from the belt position calculator; a scanning start signal generator for counting a time duration