Abstract: An image-forming apparatus comprising a process unit above a feed unit. The feed unit receives material which can selectively be fed from rolls of receiving material rotatably placed in drawers in the feed unit. A channel is formed on a panelling part of the feed unit at a working height for a standing operator. It is possible to place a roll of receiving material provided with a hollow core in the channel in order to introduce a spindle into the roll core. After the fitting of the spindle into the core, the operator can, without moving his position, place the roll of receiving material in an open drawer on bearing blocks disposed therein.

Abstract: An apparatus and method for controlling the modulation of an exposing beam of a rotating polygon type image forming apparatus using control marks formed on a rotating surface portion of a polygon member or a motor polygon assembly. The control marks are read by a reader during rotation of the polygon member, and the information read from the control marks is used to control the modulation of the exposing beam of the image forming apparatus to expose evenly spaced, uniformly sized, precisely oriented, geometrically straight scan lines of pixels on a photosensitive member. The control marks can include pixel clock information, intensity correction information, error correction information about individual facets of the polygon member, and motor speed control information.

Abstract: A scanning optical device includes a light source, a polygon mirror having a plurality of reflecting surfaces for deflecting a light flux emitted from the light source to form a scanning beam spot on an image surface, an identifying device that identifies which reflecting surface is currently scanning the light flux, a memory that stores data corresponding to shape errors of the reflecting surfaces, a correcting member that corrects a position of the beam spot, and a controller that controls the correcting member in accordance with an output of the identifying device and with data read from the memory. The correcting member is controlled to compensate for deviations of the beam spot due to tilt errors of the reflecting surfaces and may also be controlled to compensate for deviations of the beam spot due to an unevenness of the movement of the image surface.

Abstract: A first data rate detecting portion sends a first data transfer rate on a first interface, and a second data rate detecting portion sends a second data transfer rate on a second interface, respectively, to a CPU. The CPU compares the first and second data transfer rates and sets a connection state of a selector so that the image recording onto a photosensitive material is made at a high speed. The CPU also respectively determines the optimal rotation speeds of a polygon driving motor and a roller driving motor from the first or second data transfer rate, and rotates the polygon driving motor and the roller driving motor at the optimal rotation speeds. Then, when image data is inputted, an image is recorded on the photosensitive material.

Abstract: An image output apparatus such as a laser printer in which, in the case where the write density is changed, the light quantity is controlled by using a period when the rotational speed of a polygonal mirror is changed. In the apparatus, when an instruction for switching the write density is issued and the rotational speed of the polygonal mirror is set to be a changed value, a laser beam forced turn-off signal generating circuit generates a laser beam forced turn-off signal having a turn-off period which corresponds to the rotational speed of the polygonal mirror. During the period when the rotational speed of the polygonal mirror is changed, a laser beam light quantity controlling circuit controls the light quantity of the laser diode so as to have a value corresponding to the changed write density. Even during a period when the rotational speed of the polygonal mirror is changed, therefore, the light quantity can be controlled without exposing the photoreceptor to light.

Abstract: A print apparatus includes a photoconductor and a mechanical system for moving the photoconductor past a scan line exposure station. The print apparatus includes a test signal generator for providing outputs indicative of the movement of the photoconductor. A first comparator produces a first position error signal that is derived from a difference between a reference signal and a position error signal output, such position error signal indicating that the position of the photoconductor differs from a predetermined print position that is determinable with respect to the reference signal. The print apparatus further includes a laser beam scanner and a beam detector for producing a scan position signal. A second comparator is responsive to the scan position signal and the position error signal from the first comparator to produce a beam deflection control signal that is applied to a beam deflector.

Abstract: A closed type polygon scanner has a housing, a rotor which is rotatively supported to a rotating shaft fixed to the housing and which includes a polygon mirror, a motor which generates a magnetic force to the rotor and rotates the rotor, and a cover. The cover includes an outer peripheral portion fixed to an outer peripheral portion of the housing, and covers the rotor together with the housing. An opening is formed at a predetermined portion in the cover facing a mirror surface of the polygon mirror through which a laser beam passes, and a window member is fixed to the opening in closed state. An inner peripheral surface of the cover facing the mirror surface of the polygon mirror is formed cylindrically and almost coaxially to a rotating axis of the rotating shaft, and a width in the rotating axis direction of the opening is set to a predetermined width relative to a width of the polygon mirror so that turbulent air generated around the polygon mirror is reduced.

Abstract: There is provided a filter having a member of absorption material between a convex lens and a polygonal mirror. This member of absorption material is formed by coating a thin metallic film. Due to the foregoing, a predetermined transmission factor distribution can be provided. Accordingly, it is possible to correct an uneven distribution of a quantity of light on the photoreceptor caused by a change in F-number in the overfilled optical system, so that the distribution of a quantity of light can be put into practical use.

Abstract: In a raster output scanning system (ROS) of a xerographic printing device, a plurality of input optical channels direct at least one of a plurality of light beams onto separate facets of a deflector, which may be a rotating polygon mirror. The deflector deflects the light beams onto disparate optical paths. An optical system located on the disparate optical paths directs at least one of the light beams onto each of first, second, third and fourth image receiving locations. The image receiving locations may comprise a plurality of photoreceptors.

Abstract: Raster output scanner assemblies, and systems which use such assemblies, having mirrors mounted on the outside of an outer frame. Slits in the outer frame enable light to reflect from the mirrors. Beneficially, the outside mirror or mirrors are protected from contamination by mounting the primary surface of the mirrors (the surface which reflects light) against the outer frame and by mounting a cover over the mirrors.

Abstract: An intermediate transfer drum is employed and a photosensitive belt having a length equal to the outer peripheral length of the intermediate transfer drum is arranged with a vertical orientation. Developing units of the same shape are arranged on one side of the photosensitive belt, and a charging unit and a cleaner are arranged on the other side. The intermediate transfer drum is placed under or diagonally under the photosensitive belt. A transfer mechanism for transferring an image on the intermediate transfer drum to a sheet of paper is placed under or diagonally under the intermediate transfer drum. By this arrangement and construction, a small-size color electro-photographic apparatus having a size capable of easy use as a desk-top apparatus is provided, which satisfies quality of image, speed of printing, and easiness of maintenance requirements at the same time.

Abstract: A double bounce passive facet tracking system uses a single passive optical component of a toroidal mirror to induce a beam of light to track a facet of a dual mirror rotating polygon. A beam focused in both the tangential and sagittal planes is reflected from a convex facet of the polygon mirror to the toroidal mirror. The toroidal mirror collimates the light beam in a tangential plane and focuses the beam in the sagittal plane so that the beam is collimated in the tangential plane and focussed in the sagittal plane when it reaches the flat facet of the polygon mirror.

Abstract: A raster scanning optical system and method emits a first light beam and a second light beam onto a light receiving member. A scanning device has at least one facet for reflecting the first and the second light beams to the light receiving member. A light transmissive plate is located in a path of the first light beam between the first light emitting device and the scanning device. The light transmissive plate adjusts the sagittal direction and the tangential direction of the first light beam by a desired amount so that the first and second light beams are reflected from positions of the scanning device that are closer to each other and parallel in both the sagittal and tangential meridian.

Abstract: In the electrophotographic image recording apparatus, the optical path switching mechanism switches the optical path between an image reading mode and an image recording mode. In the image reading mode, the optical path switching mechanism directs light from a light scanning portion toward the original. Light reflected from the original is guided by a light guiding mechanism to a light receiving element where the light is converted into electrical signals.

Abstract: A copying machine for forming an image by scanning a laser beam which is emitted from an optical system on a photosensitive member. Photosensors are provided at optically equivalent positions to a beginning portion and an end portion of a scanning line on a photosensitive member. A scanning time of a laser beam in the main scanning direction is measured by these photosensors. The measured time and a standard time for a copy magnification set by an operator are compared, and a correction value is calculated, and at the same time, magnification in the main scanning direction is corrected using the correcting value. Also, focusing (adjusting of the beam diameter) is carried out using the photosensors. Each of the photosensors contains a photoelectric transfer element, and a beam which comes through a slit is incident to the element. Each photosensor is provided with two slits. One is perpendicular to the main scanning direction, and the other is inclined to the main scanning direction.

Abstract: A passive facet tracking system using passive optical components to induce a beam of light to track a facet of a rotating mirror polygon. The properties of the passive components are such that they collimate a light beam in a tangential plane in a complete trip through the passive optical components and the passive optical components focus the beam in the sagittal plane so that the beam is collimated in the tangential plane and focussed in the sagittal plane when it arrives at the center of the facet.

Abstract: A system for scanning or tracking, which includes a polygon rotatable about a rotational axis. The system further includes a fixed radiation source directing radiation at the polygon along a path whose extension would intersect the rotational axis of the polygon. The intersection of the extended path with the rotational axis of the polygon constituting an original imaginary intersection point. Finally, the system includes a scanned region onto which the radiation is projected, the projection being characterized in that radiation emanating from the radiation source is reflected from the polygon and is made to propagate, prior to impinging on the scanned region, along a path which includes at least one additional path segment with the additional path segment passing through or directed at an additional intersection point, the additional intersection point being a real or imaginary image of the original intersection point.

Abstract: A moving mask is incorporated in a flying spot scanner to reduce flare. The mask obscures all portions of the object being scanned, except for a small region surrounding the point currently being scanned. The mask moves to maintain registration with the flying spot. A rotating slotted disk with curved slots in cooperation with a fixed mask having a slot is described as one mechanism for achieving such masking.

Abstract: A laser beam optical scanning device which has a laser diode, a collimator lens, a cylindrical lens, a polygonal scanner and an f .theta. lens. The polygonal scanner is made of resin, and when the polygonal scanner is driven to rotate, the reflective facets of the polygonal scanner are distorted to be concave or convex because of a centrifugal force. If the reflective facets are distorted to be concave with rotation of the polygonal scanner, the image surface shifts along the optical axis toward the polygonal scanner. Therefore, in this case, the elements of the optical scanning device are positioned such that the image surface is located behind a light receiving surface while the polygonal scanner is stationary and is located nearer to the light receiving surface while the polygonal scanner is rotating.

Abstract: A control system for a ROS scanner in which the aspect ratio and magnification of an image is controlled by precise, real-time control of the relative velocities of the polygon mirror and the photoreceptor. Values related to monitored measurements of polygon mirror and photoreceptor velocity are mathematically combined with a reference clock value and other factors to yield real-time control signals. The control signals operate the polygon and photoreceptor motors to obtain a desired magnification and aspect ratio of images created on the photoreceptor.

Abstract: A raster output scanner is capable of creating images at a wide range of selectable resolutions. A laser source for creating an image is modulated at a pixel clock rate. A clock command value is determined as a function of a value related to the pixel clock rate and a value related to a desired resolution in the fast-scan direction and a desired resolution in the slow-scan direction of an image to be created on the photosensitive surface. The pixel clock rate is controlled in response to the clock command value. A polygon command value is determined as a function of the value related to the pixel clock rate, a value related to a desired resolution in the fast-scan direction of an image to be created on the photosensitive surface, and a value related to a rotational velocity of the polygon mirror. The rotational velocity of the polygon mirror is controlled in response to the polygon command value.

Abstract: An optical scanning device for leading a laser beam emitted from a semiconductor laser diode through a collimator lens, an imaging lens, and a cylindrical lens to a plurality of reflecting surfaces of a rotatable polygon mirror, and scanning a surface to be scanned movable in a vertical scanning direction with the laser beam reflected on the reflecting surfaces of the polygon mirror and transmitted through a correcting lens. The optical centers of the semiconductor laser diode, the collimator lens, the cylindrical lens, a return mirror, and the correcting lens are located in a plane containing an axis of rotation of the polygon mirror. The semiconductor laser diode, the collimator lens, and the cylindrical lens are located over an upper surface of the polygon mirror. Accordingly, an optical system can be formed in symmetry with respect to a center axis of an optical path of a horizontal scanning light beam from the polygon mirror without interference of the semiconductor laser diode, etc.

Abstract: A laser scanner control circuit which is used for an apparatus for scanning onto a photo sensitive material by a laser beam and forming an image thereon is constructed as a monolithic driver IC onto a single chip. A reset circuit is provided for a sample-hold circuit so as to minimize the laser power when the image forming apparatus is in a standby mode. A circuit to detect an abnormality of the laser power is further provided. Due to this, the safety of the laser power control of the sample-hold circuit is improved. The operation of the sample-hold circuit can be started at a time point when the laser emitting operation is stable.

Abstract: A passive facet tracking system using passive optical components to induce a beam of light to track a facet of a rotating mirror polygon. The properties of the passive components are such that they collimate a light beam in a tangential plane in a complete trip through the passive optical components and the passive optical components focus the beam in the sagittal plane so that the beam is collimated in the tangential plane and focussed in the sagittal plane when it arrives at the center of the facet.

Abstract: A laser beam optical scanning device including a housing, a light source for emitting a unidirectional laser beam, polygonal mirror for deflection scanning a laser beam emitted from the light source within a single plane, and optical members for directing the deflected scanning laser beam on the surface of a photosensitive member through a beam emission aperture of the housing. A transparent member is provided at the beam emission aperture of the housing so as to satisfy the following equation: ##EQU1## where X:distance (mm) from transparent member to surface of photosensitive member,.lambda.:laser beam wavelength (mm),D.sub.0 :beam diameter (mm) at center intensity 1/e.sup.2 on surface of photosensitive member.

Abstract: A passive facet tracking scan angle doubling system using passive optical components to induce a beam of light to track a facet of a rotating mirror polygon and to increase the scanning angle available from a rotating mirror polygon of a given size. The passive facet tracking portion of the system using passive optical components to induce a beam of light to track a facet of a rotating mirror polygon. The properties of the passive components are such that they collimate a light beam in a tangential plane in a complete trip through the passive optical components and the passive optical components focus the beam in the sagittal plane so that the beam is collimated in the tangential plane and focussed in the sagittal plane when it arrives at the center of the flat facet. The scan angle doubling portion of the system using a rotating mirror polygon, a cylinder mirror, and a lens to increase the scanning angle available from a rotating mirror polygon of a given size.

Abstract: An optical scanning apparatus comprises an optical waveguide having electro-optic effects, grating-shaped electrodes located on the optical waveguide, a driving circuit for applying a voltage across the electrodes, and a scanning device. A voltage sweep device applies a voltage, which is swept within a predetermined range, across the electrodes within a period, during which an optical wave having been radiated out of the optical waveguide is impinging upon a region outside of an effective scanning region with respect to a recording material. A photodetector detects the optical power of the radiated optical wave impinging upon the region outside of the effective scanning region. A correction device calculates an offset voltage VOFF, which corresponds to the minimum diffraction efficiency of the optical wave guided through the optical waveguide, from an output of the photodetector when the swept voltage is applied across the electrodes.