Abstract: An optical modulation element is constructed of an electro-optic crystal substrate, which includes individual electrodes arrayed and formed one-dimensionally on one surface of the substrate and also includes a common electrode formed on the other surface in opposition to the plurality of individual electrodes. The portion of the electrode-optic crystal substrate, interposed between the common electrode and each the individual electrode, constitutes an aperture portion. The aperture portion is switched between a light-transmitting state and a light cut-off state by controlling voltage between the opposite electrodes. Light incident on the aperture portion in a direction perpendicular to the arrayed direction of the individual electrodes from one surface of the electro-optic crystal substrate is modulated.

Abstract: An image forming apparatus includes a grating light valve (GLV) optical modulating device for modulating light projected by a monochromatic light source unit so that the light thus modulated is projected onto a photosensitive drum. This arrangement enables printing at a higher speed and high-quality printing using half tone. In the GLV optical modulator, a first GLV element row and a second GLV element row, each having a plurality of GLV elements provided at spaces, each space being smaller than a width of each GLV element, are provided parallel so that GLV elements constituting the first and second element rows are provided in a staggered manner.

Abstract: A system and method of calibrating pulsewidth modulation of a laser. The output power of the laser is determined and a signal indicative of the output power is provided to a printer system control computer. The control computer calibrates the pulsewidth modulated signal responsive to the signal indicative of the output power. In a preferred embodiment, the control computer includes a lookup table or a mathematical model. The control computer compensates for timing variations in the pulsewidth modulated signal induced by system components and environmental operating conditions.

Abstract: A potential estimation apparatus estimates a potential of a photosensitive body of an image forming apparatus that carries out an electro-photography process using the photosensitive body. The potential estimation apparatus includes a sensor group for sensing and outputting data related to information which affects the electro-photography process, a storage unit for at least storing the data output from the sensor group and information related to charge of the photosensitive body, and an estimation circuit including a neural network for estimating a charged portion potential of the photosensitive body based on a charge retentivity of the photosensitive body learned by the neural network.

Abstract: In a digital image forming apparatus, when a latent image is formed on a photoconductor by modulating optical intensity of laser beam, the laser beam is emitted in a period of a duty ratio while modulated according to image data, and the image is formed on a sheet of paper. This process is repeated for four colors for a color document. The duty ratio, defined as a ratio of a light-emitting time of a light exposing the photoconductor to a period for exposing a dot, is changed in the same document. For example, the light emission timing pattern is changed between odd and even lines. In another example, the light-emission timings may be changed at least for one of the reproduction colors. The light-emission timing patterns may be provided for each of reproduction colors. The light-emission timing patterns may be changed to have a constant or different screening angle between colors. Image quality of a half-tone image is improved by using such patterns.

Abstract: A method and apparatus for printing an image onto a photosensitive media. The apparatus includes an optical system having a light source for producing an exposure light; an imaging active matrix liquid crystal display through which the exposure light passes; a lens for focusing the exposure light passing through the active matrix liquid crystal display onto a photosensitive media; and a correction active matrix LCD is position between the imaging active matrix LCD and the light source for correcting non-uniformity in the optical exposure system.

Abstract: An illumination system (10) for exposing a xerographic printing apparatus (12). The system (10) includes a DMD-type imaging spatial light modulator (46), and a DMD-type optical switch (26) for modulating the intensity of the source light (15) irradiating the imaging DMD (46). A single conventional continuous wave tungsten lamp (14) is implemented with its light energy directed by a condensing lens (20) onto the DMD optical switch (26). The DMD optical switch (26) modulates the incident light (15), and passes reflected light to a light integrator (38), which in turn homogenizes and increases the aspect ratio of the light. The light integrator (38) directs the homogenized light via an anamorphic lens (40) onto the imaging DMD (46). The light energy provided to the imaging DMD (46) is precisely modulated in intensity, while remaining uniformly disbursed. The combination incandescent lamp (14) and optical DMD switch (26) offers a low cost, high-intensity alternative to LED arrays.

Abstract: A method and apparatus for printing an image onto a photosensitive media. The apparatus includes an optical system having a light source for producing an exposure light; an imaging active matrix liquid crystal display through which the exposure light passes; a lens for focusing the exposure light passing through the active matrix liquid crystal display onto a photosensitive media; and a correction active matrix LCD is position between the imaging active matrix LCD and the light source for correcting non-uniformity in the optical exposure system.

Abstract: Light beam from a light source is changed by a diaphragm so that the center of the light beam is removed. The changed light beam is deflectedly scanned by a deflection device and passed through a condenser lens so as to expose the surface of a photosensitive object. A small spot of light beam of stable intensity is therefore obtained to be irradiated on the photosensitive object. Thus, the optical scanning device has a simple structure and attains high resolution.

Abstract: Image forming apparatus and method for forming half tone images by pulse width modulating multi-valued image signals comprises first and second pattern signal generators which generate pattern signals each having the same period and a phase shifted from each other, first and second pulse width modulators for pulse width modulating said image signals using the first and second pattern signals, respectively, a selector for selecting either of the first and second pulse width modulated signals and a controller for controlling the selector to obtain a screen angle of 45.degree..Further, image forming apparatus and method which realizes a screen angle .theta. wherein tan .theta. is represented by a rational number.

Abstract: A simple optical recorder which permits alignment of scanning positions of a plurality of laser beams with high accuracy and effects optical recording using the laser beams. The optical recorder is provided with a photosensitive drum which is scanned by a plurality of laser beams formed in rows at an inclined angle with respect to the direction of scan, a single photosensor for sensing each of the sweep positions of the laser beams, and a controller for controlling the scanning positions of the laser beams on the basis of a sensing result of the sensor. The controller is made up of an optical sensing signal separation circuit, synchronous clock generation circuits, FIFO memory circuit elements, and OR circuits.

Abstract: The present invention is a an apparatus for enhancing the output along edges of discharged area developed regions in a tri-level imaging system employing a pulse width and position modulated signal ROS for exposure. The invention enables the identification and selective alteration of video data used to drive the ROS so as to extend the developed regions by a selected amount and eliminate digitization artifacts present in the image to be printed. The extension of the discharged area developed regions is accomplished by extending the width of, or adding separate, exposure pulses in adjacent areas to enable development within a portion of those regions.

Abstract: Image forming apparatus and method for forming half tone images by pulse width modulating multi-valued image signals comprises first and second pattern signal generators which generate pattern signals each having the same period and a phase shifted from each other, first and second pulse width modulators for pulse width modulating said image signals using the first and second pattern signals, respectively, a selector for selecting either of the first and second pulse width modulated signals and a controller for controlling the selector to obtain a screen angle of 45.degree..Further, image forming apparatus and method which realizes a screen angle .theta. wherein tan .theta. is represented by a rational number.

Abstract: An electrophotographic color image forming machine registers which a second color toner image on a first color toner image which has been previously formed on an image carrier to form a color image. The registered images are then transferred onto a recording sheet. The machine includes control apparatus that includes first and second exposure control modulators which respectively control an exposure amount of at least one of the first color toner images and the second color toner image. A smoothing processor controls at least one of a size and a position of at least one of the first and second color toner dot images within each of a plurality of pixels and a discriminator determines whether one of the size and the position of the dot image should be controlled.

Abstract: There is disclosed a system and method for assembling all of the parts of a xerographic system in a unitary housing. The unitary molded housing contains the xerographic optics, the modulator, the toner and developer cartridges as well as the printer drum. Using this unitary housing, the modulator can be aligned by using optical sensors in substitution for the printing drum during assembly, and can contain other components such as a document scanner that allows the print engine to also be used as a fax machine, or a copier.

Abstract: An image forming apparatus which comprises a laser light source, a light beam scanning unit which scans an image receiving member with a light beam, and an optical system for forming a spot of the light beam, which has a predetermined diameter. The light beam is modulated by a pulse modulation unit based on the density data of an image. The size of picture elements formed on the image receiving member is a function of parameters of the laser scanning unit and the pulse modulation unit, and the spot size is designed at least 1.7 times as large as the corresponding size of picture elements.