Abstract: A semiconductor light exposure device reducing coherency of laser light to an appropriate value by a simplified structure without producing speckles. The semiconductor light exposure device includes an ultraviolet light generating device, a uniform illumination device having the operation of inducing an optical path length difference and a projection device for projecting the laser light from the uniform illumination device. The ultraviolet light generating device includes an Nd:YAG Q-switch laser unit with a wavelength of 1064 nm, oscillated with a longitudinal single mode, a phase modulation unit or phase-modulating the fundamental laser light outgoing from the Nd:YAG Q-switch laser unit with voltage signals having plural frequency components, and a wavelength conversion unit for converting the wavelength of the fundamental laser light phase-modulated by the phase modulation unit into an ultraviolet laser light with a wavelength of 213 nm as a fifth harmonics.

Abstract: An apparatus and method for controlling an image recording device. The apparatus includes an acousto-optic deflector that deflects a beam of light so as to write a sub-scan comprising a predetermined number of picture elements. The image recording device is arranged to write a plurality of sub-scans side by side in a substantially contiguous manner. The apparatus also includes a component that commences sub-scans, a start of sub-scan detector that detects when the light beam is directed towards a start of sub-scan position, and an end of sub-scan detector that detects when the beam of light is directed towards an end of sub-scan position. A timing logic controller generates a start reference signal representing a desired position for the start of a sub-scan. A controller compares an output of the start of sub-scan detector with respect to the start reference signal.

Abstract: A grating modulator array (40) is comprised of a plurality of modulator sites (41). Each modulator site (41) is comprised of a plurality of first poled regions (50) and a plurality of second poled regions (51) alternating with said first poled regions. A first electrode (48a) is attached to a first end of each of the modulator sites and a second electrode (48b) is attached to a second end of each of the modulator sites and each of the electrode pairs establishes a field in the poled regions of the modulator sites which causes a phase shift in polarized light incident on the modulator.

Abstract: Disclosed is a full color printer which comprises a optical writing head for writing a latent image onto a printing paper such as a silver salt-sensitive member. The optical writing head has an array of optical shutter elements each of which is made of PLZT. Red color light, green color light, and blue color light are sequentially projected to the light shutter element, and the drive voltage applied to the light shutter elements is changed synchronized with the color change. To prevent the generation of spike noise, the drive voltage is not changed suddenly, but is changed smoothly.

Abstract: The exposure time of high data rate single spot laser scanner can be extended by the use of Time Domain Integration (TDI) mode imaging to expose thermographic materials. Many thermographic materials, such as thermal printing plates, can not be properly exposed in single spot scanners such as internal drum scanners, due to the shortness of the exposure time of a single spot, but can be exposed by the extended exposure time of TDI scanning. The Scophony effect can also be used as a method of TDI.

Abstract: A laser pattern generator for semiconductor mask making or direct writing of features on a semiconductor wafer uses a pulsed laser source to achieve high power and short wavelength (e.g. 263 nm or less) radiation, for writing very small-sized features. The laser pulse frequency is either synchronous or asynchronous to the writing grid of the features being written, in various embodiments.

Abstract: A printer system for producing color prints includes: (a) three light sources, each generating a light beam of different wavelengths; (b) three modulators, each of the modulators modulating intensity of each of the light beams by image data, to provide three modulated light beams; (c) a beam combiner combining the three modulated light beams into a single light beam; (d) a single set of beam shaping optics shaping this single light beam into a shaped light beam having different vergences and waist locations in the page and line directions, the vergences and the waist locations being substantially the same in each of the three wavelengths; (e) a light deflector deflecting the shaped light beam to provide a deflected beam, and performing a scanning function; (f) an f-.theta. lens focusing the deflected light beam onto an associated image surface.

Abstract: Direct dye thermal transfer printing, sublimation dye printing and thermal wax printing may be effected by impinging the energy modulated zero order beam of a laser print energy source on an image forming substance such as a direct dye thermal transfer printing medium, a sublimation dye printing medium, and a thermal wax printing medium. Printing may also be effected by a method involving providing an original electronic color data set, which contains pixels which contain intensity information in the time domain optionally increasing the optical resolution of the data set, dividing one or more of the pixels in the time domain, to obtain a data set containing one or more time-sliced pixels, and printing the data set containing one or more time-sliced pixels.

Abstract: A method and structure for a printing system for a laser printer is provided including a data storage area containing a plurality of separate waveform signals. A controller selects a particular waveform signal to modulate the signal input to the system laser diode switch element to generate a halftone cell or a resolution enhancing cell with desired gray scale pixels. The digital laser signal from the printer controller is passed through a digital-to-analog converter circuit to a comparator circuit. The particular waveform selected from the data storage area is also applied to the comparator circuit to modulate the output signal from the digital-to-analog converter. The analog modulated signal from the comparator circuit has an analog value that maintains the laser diode switch element "on" to provide sub-pixels for the particular pixel gray level that is desired.

Abstract: A liquid crystal device for use in sequentially producing an image composed of three separable color plane images including a light diffuser including a sheet of material having a front face and least three sides and which, when light passes through the sides into the diffuser, causes uniform illumination to be produced from the front face and a liquid crystal display disposed in relationship to the front face of the diffuser to receive light from such front face and responsive to electrical signals corresponding to an image to be produced and light from the diffuser to illuminate an image on the liquid crystal display.

Abstract: In classic optical rendering systems, the spot, illuminating a microdot on the photosensitive medium, is designed to overlap with neighboring microdots, typically having an overlap of 1.7 times the pitch of the microdots, for a luminous intensity of 1/e.sup.2 the highest intensity. A "sharp" photosensitive medium, such as a photographic film used in graphical applications, generates a binary circle, obtainable by thresholding. The area of such a circle is too large, which results in higher dot gain.Many systems, such as electrographic systems, do not behave as a "sharp" medium. If intermediate energy levels are used, in order to obtain continuous tone or multiple density levels, thresholding behavior may be avoided by appropriate choice of energy levels. Such a different sensitometry results in specific requirements for the energy distribution for each microdot.

Abstract: A method of producing an image on a printing medium comprises producing a pulse train of modelocked laser pulses, providing a source of image input data in the form of a series of gate pulse of varible length and modulating the pulse train with reference to the gate pulses to produce a gated pulse train for producing the image on the printing medium. An apparatus for carrying out the method is also provided.

Abstract: Raster scanner assemblies, and machines which use such raster scanner assemblies, which produce spots having a variable spot dimension. Raster scanner assemblies according to the present invention include an electronic subsystem which produces both image data and a spot size control signal, a laser assembly which produces a polarized laser beam having a beam with a first dimension and which is modulated in accord with the image data, a variable aperture assembly which changes the first dimension of the laser beam, a rotating polygon having a plurality of facets sweeping the laser beam in a sweep plane, and a scan lens for focusing the laser beam onto an image plane. The variable aperture assembly beneficially includes both a liquid crystal cell, which receives the laser beam and the spot size control signal, and a polarizing filter.

Abstract: A printer for creating images on photosensitive sheets, receives digital images and uses a display to print the images onto a photosensitive medium. An optic projects image from the display onto photosensitive media. The printer converts the image data into separable binary planes of data sequentially transfers the separate binary planes to the display to create continuous tone images on the photosensitive media.

Abstract: A color printer prints a color image on photosensitive material by utilizing a digital micromirror device. The digital micromirror device is provided with four micromirror arrays constituted of plural micromirrors. The four micromirror arrays record four lines on a photographic paper at the same time while the photographic paper is successively advanced at constant velocity. Red exposure sequence, green exposure sequence and blue exposure sequence are performed in order while the photographic paper is advanced by L. Each of the exposure sequences is changed in order every advancement of photographic paper by L/3. The photographic paper passes through four lines projected by the four micromirror arrays in order. Accordingly, a pixel on the photographic paper is exposed four times at the ceiling by four micromirrors arranged on a same row for each color. Accordingly, multiple exposure is performed during advancement of the photographic paper.

Abstract: Apparatus for printing images from a liquid crystal display included within an image capture device including a liquid crystal display; a source of fluorescent light which includes phosphors selected so that fluorescent light which passes through the liquid crystal display is modified to be daylight balanced; and a printer which includes photosensitive media which is adapted to be illuminated by the light image from the liquid crystal display.

Abstract: A system and method of providing a periodic trajectory scan path for a laser beam across a photoconductive surface in a laser printer. A preferred embodiment of the periodic trajectory for a system with a two-axis deflector includes a multiple-frequency omega wave trajectory for providing a substantially rectangular grid of available dot locations for selective laser beam pulsing. As such, a plurality of generally linear rows of dots are completed in a single scan pass of the laser beam across the surface. The periodic trajectory is provided by deflecting the laser beam with an optical beam deflector, such as an electro-optic deflector, placed between the laser and the rotating polygon scanning mirror. A preferred embodiment of the beam deflector includes a folded optical path.

Abstract: A multi-channel acousto-optic spatial modulator for fast signal processing by a plurality of acousto-optic modulating cells connected in a line. The multi-channel acousto-optic spatial modulator in accordance with the present invention comprises a plurality of modulating cells each for modulating the incident light, acoustic waves being created within each of said plurality of modulating cells; and a plurality of absorbing plates each interposed between said two modulating cells for shielding the acoustic wave created within one of said two modulating cells from being propagated into the other of said two modulating cells.

Abstract: An optical recording and data processing system for exposing an image on to a flexible, light sensitive medium, which includes a medium holder having an inner cylindrical wall portion against which is held said medium, and a light source having an approximately rectangular emitting aperture, with a short aperture axis and a long aperture axis, operative to emit a beam of light having a rectangular cross section with a long axis corresponding to the long aperture axis and a short axis corresponding to the short aperture axis. An optical modulator is aligned with the light source so as to intercept light from the beam of light and produce a spatial modulation pattern across the long axis of the beam of light. A pattern shifter for shifting the spatial modulation pattern across the length of the long axis at a constant rate is provided as is a pattern rotator for rotating the spatial modulation pattern at a rate equal to the rate of shifting of the spatial modulation pattern.

Abstract: A system and method of deflecting a laser beam in a laser printer for providing enhanced resolution and reduced banding effects. Specifically, to enhance resolution, the laser beam is borrowed (deflected) from a white space area adjacent an image to double resolution at the edges of the image. Similarly, banding is reduced by deflecting the beam to compensate for drum rotational and translational errors. The beam is deflected using an electro-optic modulator placed between the laser diode and the scanning mirror. Encoders detect drum rotational errors and motion between the optics unit and the drum to provide a closed loop feedback system for reducing banding.

Abstract: A method and apparatus is provided for exposing the recording material. A light beam is generated by a light source. The light beam passes through an optical isolator, through a light modulator, and then exposes recording material point-by-point and line-by-line. The modulator is activated during exposing of each line in an exposing time span, the modulator being deactivated at least at times within a return time span for each line. The optical isolator is enabled during the exposing time span. To compensate for heating of the optical isolator, the optical isolator is also activated for at least a portion of the return time span. A sum of time extents of the exposing time span and the compensation time span are approximately a constant for each line. Activation of the isolator during the compensation time span compensates for thermal effects which occur in the optical isolator as a result of activation and de-activation thereof.

Abstract: A laser liquid crystal marker and a method of judging deterioration of the liquid crystal make it possible to maintain high printing accuracy, ascertain the proper time for replacement of liquid crystal and, further, maintain high printing accuracy even when high speed printing is continuously performed. The marker has a temperature sensor (4), light emitting means (5), light receiving means (6), and a controller (7). The controller (7) calculates a light transmittance (Qi) from the irradiation quantity of light (R1) of the light emitting means (5) and the transmitted quantity of light (R2) received by the light receiving means (6), and adjusts the applied voltage (Vi) of the liquid crystal (2) so that the light transmittance (Qi) becomes equal to an optimum light transmittance (Qo), stored in advance.

Abstract: A laser beam emitted from a stripe-shaped area of a laser diode is expanded in its low divergence axis to match a length of a modulator which individually modulates different regions of the beam to produce a plurality of individually modulated beam portions which are focused by a lens onto a recording medium, such as dye and receiver sheets, to effect data recording. The modulator may be a row of LCD cells, an acousto-optic modulator, or a row of micromirrors.

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: A modulator for modifying a scanning beam to project a halftone image onto a photosensitive surface including a sensor providing sensor signals in relation to the speed of the photosensitive surface, a converter responsive to the speed of the photosensitive surface to provide a signal representing an image quality factor for altering the modulation of the beam of the scanning system to adjust the projected image in relation to the speed of the photosensitive surface, the projected image including banding errors, and a random signal generator responsive to the sensor signals for generating random signals, the random signals altering the modulation of the beam of the scanning system to counter the banding errors on the projected image.

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 modulator circuit for use in driving a laser in an electrophotographic laser printer starts with a standard, inexpensive low-frequency pixel clock for timing the modulation of the laser to form an image, and effectively doubles the modulation frequency, thereby allowing spatial resolution to be doubled in the fast-scan direction. An original, low-frequency pixel clock is split, one of the split signals is delayed by a predetermined amount, and the original and delayed pixel clocks are applied to an exclusive OR gate. The modulator of the present invention functions without either a high-frequency original pixel clock or a phase-locked loop.

Abstract: A galvanometer optics assembly includes a housing which has a laser beam input which is optically coupled to the laser beam output of the laser marking apparatus, a first laser beam output and a second laser beam output, a stationary mirror which is fixedly coupled to the housing and is optically coupled to the laser beam input of the housing, a galvanometer mirror which is rotatively coupled to the housing and is optically coupled to the stationary mirror, a galvanometer optics motor which has a shaft which is fixedly coupled to the galvanometer mirror so that the galvanometer mirror may be optically coupled to either the first laser beam output or the second laser beam output and a galvanometer controller which is electrically coupled to the galvanometer optics motor. The galvanometer optics assembly is for use with a laser marking apparatus which includes a housing and and a laser beam output which is optically coupled to the lasers.

Abstract: A digital printer for printing images in response to full-frame, two-dimensional digital image data input from an outside source. The digital printer is a novel combination of a two dimensional backlight for producing full frame illumination in a single flash, a photoreceptor sensitive to light emanating from the backlight, a two-dimensional, transmissive light valve, an imaging system, and a driver. The light valve is disposed between the backlight and the photoreceptor so that light from the backlight is transmitted through the light valve, producing a full-frame, two dimensional image on the photoreceptor in response to a single flash of the backlight. The full-frame, two dimensional image corresponds to a pattern formed on the light valve in response to the full-frame, two dimensional digital image data. The imaging system is disposed between the light valve and the photoreceptor, such that it focuses the full-frame, two dimensional image onto the photoreceptor.

Abstract: Higher quality printing is difficult in implementation in spatial light modulator printers. The two major problems are accomplishing gray scale within the line time constraints, and eliminating staircasing artifacts within the images printed (81). It can be improved by using an alternate way of resetting cells on the spatial light modulator when data is being loaded onto the cells, timing delay (86), horizontal offset (84), and differently sized pixels (80, 82).

Abstract: A device for patterning an imaging member (46) is provided. The device comprises a light source (24) which emits light rays (26). Light rays (26) pass through a collimator lens (28) to collimate the light rays (30). The light then strikes a spatial light modulator (32) which is controlled by a computer (40) to reflect the light (42). The light passes through an imaging lens (44) to magnify the pattern for striking imaging member (46). Imaging member (46) is thus patterned by changing modulator (32) by computer (40).

Abstract: The present invention relates to a transmission type liquid crystal mask marker which can be incorporated easily into a conventional apparatus, and which enables high-speed and high-accuracy stable printing and an increase in the S/N ratio of a sensor output. The transmission type liquid crystal mask marker thus includes a controller for, during rewriting a static marking image displayed on a transmission type liquid crystal mask, displaying a static test image and attaining an equipotential state, and thereafter repeatedly displaying the static marking image and attaining an equipotential state up to the end of the rewriting time, measuring an actual light transmittance of the static test image during rewriting, and regulating the voltage applied to the transmission type liquid crystal mask so that the actual light transmittance is equal to the optimum light transmittance. An optical filter can be provided on a light receiving device for measuring a light transmittance.

Abstract: In a digital image forming apparatus, the intensity or the pulse width of laser beam exposure is modulated according to image signals of a document detected by a sensor. A peak waveform having a peak is generated in each light-emitting period of laser beam. For example, and a signal having a peak is synthesized with the image signals to generate the peak waveform. Thus, the laser is driven according to the peak waveforms so that the exposed portions on a photoconductor in correspondence to the peaks are exposed with a larger quantity of light at low densities. Then, the amount of the gamma correction can be decreased and the gradation characteristic can be stabilized.

Abstract: Higher quality printing is difficult in implementation in spatial light modulator printers. The two major problems are accomplishing gray scale within the line time constraints, and eliminating staircasing artifacts within the images printed (81). It can be improved by using an alternate way of resetting cells on the spatial light modulator when data is being loaded onto the cells, timing delay (86), horizontal offset (84), and differently sized pixels (80, 82).

Abstract: A laser pattern inspection and/or writing system which writes or inspects a pattern on a target on a stage, by raster scanning the target pixels. Inspection can also be done by substage illumination with non-laser light. A database, organized into frames and strips, represents an ideal pattern as one or more polygons. Each polygon's data description is contained within a single data frame. The database is transformed into a turnpoint polygon representation, then a left and right vector representation, then an addressed pixel representation, then a bit-mapped representation of the entire target. Most of the transformations are carried out in parallel pipelines. Guardbands around polygon sides are used for error filtering during inspection. Guardbands are polygons, and frames containing only guardband information are sent down dedicated pipelines. Error filtering also is done at the time of pixel comparisons of ideal with real patterns, and subsequently during defect area consolidation.

Abstract: A method and apparatus for writing onto a photosensitive material with a single white light source. The apparatus includes a light source for producing a light composed of at least two color components, a collimating lens for collimating the light emanating from the light source so as to form a beam of light, and a beam splitter for splitting the beam of light into a plurality of individual predetermined beams of light, each having a different color. A modulator is also provided for modulating the intensity of each of the color beams of light individually in accordance with image data for each of the colors. The individual light beams are then recombined into a single beam of light and directed onto a photosensitive material.

Abstract: An optical beam scanning apparatus which includes: an optical modulator which emits an optical beam in a direction corresponding to the frequency of an inputted signal; scanning device for scanning the optical beam; a scanning lens; a storage device which stores data for correcting the displacement of the optical beam passing through the scanning lens caused by an aberration of the scanning lens for each scanning position of the optical beam; and a device which, based on the data stored in the storage device, alters the frequency of the signal to be inputted to the optical modulator for each scanning position of the optical beam so as to correct the displacement of the optical beam caused by the aberration of the scanning lens.

Abstract: A method and apparatus for printing stroke and contone data together are provided in which data to be printed (102) is identified by a processor (100) as being either stroke or contone data. For contone data, processor (100) controls a light source (14), a spatial light modulator (12), and an optical photoconductive drum (16) to generate image quality graphics by using spatial light modulation in the process and cross-process directions. For stroke data, processor (100) controls light source (14), spatial light modulator (12), and optical photoconductive drum (16) for high resolution printing by using intensity modulation. Processor (100) is operable to control light intensities through the use of lookup tables stored in a memory (104).

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: There is disclosed a line printing system of this invention which utilizes an array of asymmetrical Fabry-Perot light valves for simultaneously transferring all pixel information of one raster line onto a photoreceptor. The number of elements of the light valve array used in this invention is equal to the number of pixels on a raster line. The pixel information is applied to elements of the light valve array in a parallel format with information representing each pixel applied to one elemental light valve of the array. The array is illuminated by a wedge-shaped incident light beam forming a focussed line image. Depending on the information state of each pixel, each corresponding element will be activated to absorb incident light or left in its neutral state to reflect the light. Light reflected by neutral elements will be directed onto the photoreceptor. In this fashion, the photoreceptor simultaneously receives the pixel information for the entire raster line.

Abstract: A method of optically recording original information supplied from information generating device on an optical recording material in an optical recording apparatus, comprising the steps of: generating, from the original information, interpolating information which is to be interpolated in a sub-scanning direction of the optical recording material; and optically recording the interpolating information in the sub-scanning direction by a plurality of laser beams.