Abstract: In a multi-exposure drawing method for drawing a pattern on a drawing surface, using an exposure unit including a plurality of optical modulation elements arranged in both a first array-direction and a second array-direction, the exposure unit is moved in relation to the drawing surface in a drawing direction. The drawing direction is inclined to form an angle with respect to the first array-direction, whereby the exposure unit is gradually shifted in the second array-direction during the movement of the exposure unit. The modulation elements are successively and selectively operated based on pattern bit-data to thereby modulate a light beam made incident on each modulation element, whenever the exposure unit is moved in the drawing direction by a distance of “A+a”. “A” is a distance corresponding to an integer-multiple of a dimension of a unit exposure zone produced on the drawing surface by each modulation element, and “a” is a smaller distance than the dimension of the unit exposure.

Abstract: The image recording method and image recording apparatus synchronize phase of a light deflector with rotation of a drum in response to the drum start point detection signal generated each time the drum rotates once, expose the two-dimensional image of one frame formed by a group of light sources disposed two-dimensionally onto the recording medium while causing the image at rest on the recording medium relatively thereto, thereafter move the optical system in the auxiliary scanning direction by an integral multiple of a pixel pitch forming one frame as well as deflect an angle of the light deflector in the main scanning direction by one frame so as to expose the next frame and on for one rotation of the drum.

Abstract: A liquid transfer article is provided including a support assembly and an imaged surface formed directly on the surface of the support assembly by digital photopolymerization. The support assembly is in the form of a polymeric base, and the liquid transfer article is formed by providing a liquid photopolymer on the surface of the base and then irradiating the polymer with a light source to form the image. The liquid transfer article is reimagable and may be used in gravure printing processes, as well as other printing applications.

Abstract: Apparatus far transmitting information at a data rate, such as for recording an image on a photosensitive surface, including a pulsed light source that produces pulsed light having a pulsed repetition rate and a modulator that asynchronously modulates the pulsed light at the data rate, wherein the data rate is higher than pulse repetition rate.

Abstract: An optical scanning device includes optical modulation means having an one-dimensional optical modulator array wherein a plurality of optical modulators are arranged one-dimensionally; lighting means; and a scanning optical system for deflecting the beams modulated by the optical modulators in the one-dimensional optical modulator array in a direction perpendicular to the arrangement direction of the optical modulators. A plurality of the one-dimensional optical modulator arrays are arranged in a direction perpendicular to the arrangement direction of the optical modulators. The beams modulated by respective optical modulators of the one-dimensional optical modulator arrays can be irradiated on a pixel in piles.

Abstract: In the present invention provides, in order to obtain a desired focal depth t in a range ? of an acceptable increased amount of beam diameter, an exposure head is designed so that the ratio D/W of an output beam width D to a beam width W at the position where a DMD is placed satisfies the following relational formula. D W ? ? × M 2 × t - K × ? a ? In the above formula, parameters are defined as follows.

Abstract: A laser source emits a laser beam having a peak wavelength within the range from 800 nm to 820 nm. The laser beam emitted from the source passes through an illumination lens, and then impinges on a Grating Light Valve™. The light valve splits the laser beam into a multiplicity of light beams, modulates the multiplicity of light beams in response to image signals, and produces zero-order diffracted signal beams. The zero-order diffracted beams pass through an imaging lens, and are imaged on a recording medium wrapped on the surface of a drum.

Abstract: A method of scanning for writing a pattern on a surface, including providing a scanning beam comprised of a plurality of independently addressable sub-beams, scanning the surface with the scanning beam a plurality of times, the sub-beams scanning the surface side-by-side in the cross-scan direction, each sub-beam being modulated to reflect information to be written, and overlapping the beams in successive scans in the cross scan direction such that all written areas of the surface are written on during at least two scans.

Abstract: In one embodiment, the present invention provides a scan line controller for use with a laser scanning device. The scan line controller includes a pulse width modulator system to receive a pulse code, including a first pulse width modulator to receive a first dot clock and a second pulse width modulator to receive a second dot clock, and to provide a video driver signal to a laser unit to provide a scan line from the video driver signal. The scan line controller further includes a space insertion/deletion unit configured to adjust a scan line length by inserting or deleting one or more delays into the first and the second dot clocks.

Abstract: A method and apparatus for scanning a common scan line in a main scanning direction with a light emitting device is provided. The method and apparatus preferably generates at least a first control signal and a second control signal for driving the light emitting device, the first control signal and the second control signal being generated from image data for the common scan line in the main scanning direction, drives the light emitting device with the first control signal to scan the common scan line in the main scanning direction, and drives the light emitting device with the second control signal to scan the common scan line in the main scanning direction.

Abstract: An apparatus for printing images from digital image data onto a light sensitive medium disposed at an image plane which comprises a control logic processor capable of controlling the operation of the apparatus for printing based on the digital image data. An image forming assembly directs an exposure beam to the light sensitive medium disposed at the image plane. The image forming assembly (10) comprises a light source, a first lens assembly (41), a beamsplitter (50), a spatial light modulator (52), a temperature profile control apparatus (51) and a second lens assembly (132).

Abstract: An apparatus and method of printing images onto a photosensitive media (140) using multiple reflective spatial light modulators (87, 88, 89, 90, 95, 97). In the apparatus and method, illumination optics uniformize and image light from at least one light source (20) through polarization beamsplitting elements (60, 63). The polarization beamsplitting elements (60, 63) divide the illumination light into two polarization states. One polarization state of the illumination light illuminates the reflective spatial light modulators (87, 88, 89, 90, 95, 97) in a telecentric manner. The reflective spatial light modulators (87, 88, 89, 90, 95, 97) are addressed with image data signals. The reflective spatial light modulators (87, 88, 89, 90, 95, 97) modulate the polarized illumination light on a site by site basis and reflect the modulated light back through the polarization beamsplitting elements.

Abstract: An electrostatic-writing mechanism for an image-formation device having an optical photoconductor (OPC) mechanism of one embodiment of the invention is disclosed that includes a light source and an array of micromirror devices. The light source is to emit light. The array of micromirror devices is to selectively direct the light onto the OPC mechanism in accordance with a portion of an image.

Abstract: While light of R, G and B is switched from one to another and directed to a plurality of light shutter elements made of PLZT, a voltage is applied in accordance with image data between individual electrodes for the respective light shutter elements and a common electrode for all the light shutter elements. While a half-wave voltage Vr for light of R is applied to the individual electrodes, the voltage applied to the common electrode is altered to 0V, Vr-Vg and Vr-Vb in synchronization with switch of the three primary colors so that half-wave voltages for the respective colors can be applied to the light shutter elements.

Abstract: A linefeed calibration method for identifying media advancement errors utilizes plural test patterns, including both a base pattern and an overlay pattern that are printed overlying each other to form an interference pattern. A sensor detects overall alignment of the interference pattern. That overall alignment is compared to alignment of at least a second interference pattern to identify a linefeed advance error. The error is correlated to a position on a media advancement mechanism such as a roller. A processor then adjusts the media advancement mechanism to correct the identified media advancement error. Under-advance errors, over-advance errors and skew errors may be identified using the described method.

Abstract: A printing method and apparatus (100) for pre-exposing a digital watermark along a length of photosensitive medium at the time of manufacture is disclosed. The printing apparatus has an illumination source (60) for providing an exposure illumination, first and second LCD spatial light modulators (90a, 90b) for modulating the exposure illumination to form first and second exposure patterns according to image data, combining optics providing a single output path for directing both first and second exposure patterns onto the photosensitive medium and transport means for providing, during exposure, lengthwise displacement of the photosensitive medium with respect to the output path. The first and second exposure patterns form, lengthwise along the photosensitive medium, a latent image with modulated stripes having a predetermined intensity corresponding to the exposure patterns.

Abstract: An apparatus and method of printing images (10) onto a photosensitive media (140) using multiple reflective spatial light modulators. In the apparatus and method, illumination optics (25) uniformize and image light from at least one light source through polarization beamsplitting elements (80). The polarization beamsplitting elements (80) divide the illumination light into two polarization states. One polarization state of the illumination light illuminates the reflective spatial light modulators in a telecentric manner. The reflective spatial light modulators are addressed with image data signals. The reflective spatial light modulators modulate the polarized illumination light on a site by site basis and reflect the modulated light back through the polarized beamsplitting elements (80). The modulated light beams are combined to form an image, which is directed through a print lens (110) to expose a photosensitive media (140).

Abstract: An optical recording art is characterized by converting a light from a light source into a modulated light including an amplitude-modulated light and a phase-modulated light and forming an image of the modulated light on a surface of an object.

Abstract: A printer includes an image area sensor for picking up a picture frame in photo film to output image data. A printing projecting lens focuses and records a print frame to color photographic paper. Three LED light sources generate light. A digital micromirror device (DMD) is disposed in a traveling path of the light, includes plural micromirrors arranged in at least one array. The plural micromirrors are individually shiftable between first and second positions different in a direction, and when in the first position, direct the light to the photo film by reflection, and when in the second position, direct the light to the printing projecting lens by reflection. A controller initially sets the plural micromirrors in the first position, to illuminate the picture frame in the photo film while the image area sensor is operated.

Abstract: A container is provided which comprises a cylindrical main body having an end wall at an end thereof; an outlet projecting from an outer surface of the end wall for allowing a content to be supplied; and a protecting member disposed on the outer surface of the end wall so that it surrounds the outlet and defines a groove portion between the outlet and the protecting member. The protecting member is preferably a continuous or discontinuous annular projection. A conduit of a pump can be coupled to the groove portion by engaging an inner circumferential surface of the protecting member with an outer circumferential surface of the conduit, or by engaging an outer circumferential surface of the outlet with an inner circumferential surface of the conduit.

Abstract: The optical modulator includes an optical waveguide for receiving light entered from a first end surface thereof and for emitting the light from a second end surface opposing to the first end surface, a flexible light transmitting member disposed so as to face with a boundary surface of the optical waveguide and has a gap between the flexible light transmitting member and the boundary surface of the optical waveguide and a modulation device for bringing the flexible light transmitting member into contact with the boundary surface of the optical waveguide. The image recording apparatus includes the above exposure head and a scanning device for relatively moving a photosensitive material and the exposure head.

Abstract: In an exposure apparatus of the invention, for a spatial light modulator, each of a plurality of pixel portions fewer than the total number of the pixel portions is controlled with a control signal generated according to exposure information. Namely, a part of the pixel portions is controlled without controlling a whole of the pixel portions on the substrate. Thus, the number of pixels in the pixel portions is decreased, and transfer time of the control signal becomes short. This enables modulation speed of the laser beam to be increased and the high-speed exposure to be performed. An incorporated laser light source, in which the laser beams are incorporated and struck on the optical fiber, is preferable to the laser device. By adopting the incorporated laser light source, high brightness and high output can be obtained, and it is preferable to the exposure of the spatial light modulator. Since the fiber array is obtained with few optical fibers, it is low cost.

Abstract: An optical printer has a DMD as a spatial light modulator. An optical image corresponding to a picture frame is projected from the DMD onto a photographic paper in a variable size to print the picture frame in a designated print size. When a maximum print size is designated, image data stored in three color image memories is entirely converted into mirror drive data for driving all micromirrors of the DMD in accordance with the image data. When a smaller print size is designated, the image data is thinned to reduce the image data size in correspondence with the smaller print size. Also a smaller area of the DMD is selected as an active area in which micromirrors are driven in accordance with the thinned image data, to print a picture in the smaller print size.

Abstract: An image recording apparatus (1) has a stage unit (2) for holding a substrate (9), an irradiation unit (4) having a plurality of irradiation parts (40) and a mechanism for relatively moving the stage unit (2) and the irradiation unit (4). An irradiation part (40) is provided with a DMD having a group of micromirrors for modulating a reflected light beam and a micro moving mechanism for moving the DMD relatively to the irradiation unit (4) in the X direction, thereby microscopically moving an irradiation position of the irradiation part (40) in the X direction. The irradiation part (40) is further provided with a zoom lens, thereby magnifying and reducing an image of the DMD on the substrate (9). By controlling a plurality of irradiation parts (40) parallelly and independently, the image recording apparatus (1) can write a fine pattern at high speed.

Abstract: A liquid transfer article is provided including a support assembly and an imaged surface formed directly on the surface of the support assembly by digital photopolymerization. The support assembly is in the form of a polymeric base, and the liquid transfer article is formed by providing a liquid photopolymer on the surface of the base and then irradiating the polymer with a light source to form the image. The liquid transfer article is reimagable and may be used in gravure printing processes, as well as other printing applications.

Abstract: A method of clocking a video processing circuit is performed by stalling a reference clock signal. The reference clock signal is stalled based on a stall signal from a clock-independent pulse width modulator. The stalled reference clock signal is used to produce a video clock signal for use by an image data processing circuit.

Abstract: An object substrate that contains a markingly effective amount of a radiation sensitive marking material such as titanium dioxide is subjected to a patterned pulsed beam of coherent energy having a level of flux density that is at least sufficient to cause the radiation sensitive marking material to change color without degrading the object substrate. The pulsed beam of coherent energy derives its pattern from the instantaneous configuration of individual mirrors on the face of a digital mirror device (DMD) as the energy is reflected from that mirror face. The level of flux intensity at the mirror face is less than the level at which the DMD is at risk of damage or disruption. The level of flux intensity at the object substrate to be marked is sufficient to cause the titanium dioxide to change color, and substantially above the level at which the DMD is at substantial risk of damage or disruption.

Abstract: An aspect of the present invention includes a method to print pattern with improved edge acuity. In one embodiment a method for printing fine patterns comprising the actions of: providing an SLM and providing a pixel layout pattern with different categories of modulating elements, the categories differing in the phase of the complex amplitude. Other aspects of the present invention are reflected in the detailed description, figures and claims.

Abstract: A method and apparatus for reducing contamination on the protective lids of a grating light valve (GLV) and a calibration sensor in an imaging system. A shroud surrounds the protective lid of the GLV/sensor. An airflow system inputs a stream of air into the shroud, and the shroud directs the stream of air away from the GLV/sensor. A pellicle may also be used to enclose the GLV/sensor to prevent contamination of the protective lid.

Abstract: In an image recording apparatus for recording an image by guiding zeroth order diffracted light beams from a plurality of diffraction grating type light modulator elements as signal beams to a recording medium, a transition of each of light modulator elements from an OFF state to an ON state is detected and when this transition is detected, the light modulator element is temporarily supplied with an auxiliary driving voltage (V3) between a driving voltage (V1) for bringing the light modulator element into the ON state and a driving voltage (V2) for bringing the light modulator element into the OFF state. This suppresses an overshoot due to a sharp change of the light modulator element to the ON state and achieves beam writing with appropriate line space ratio.

Abstract: An electrostatic-writing mechanism for an image-formation device having an optical photoconductor (OPC) mechanism of one embodiment of the invention is disclosed that includes a light source and an array of micromirror devices. The light source is to emit light. The array of micromirror devices is to selectively direct the light onto the OPC mechanism in accordance with a portion of an image.

Abstract: A driving element (120a) for driving light modulator elements (121) is provided with a register (441a) for storing driving voltage data (301) and clock selection data (303), a clock selection part (442a) for selecting an update clock (302) out of a group of control clocks (304) on the basis of the clock selection data (303), and a D/A converter (442b), a current source (32) and a resistance (33) for converting the driving voltage data (301) into a driving voltage. The timing of the update clock (302) is shifted by the clock selection data (303), to thereby control a driving timing of each light modulator element (121). This makes it possible to achieve an appropriate writing while suppressing effects of driving characteristics of the light modulator elements (121), the widths of irradiation areas irradiated by the light modulator elements (121) in a scan direction, photosensitive characteristics of a recording medium and the like.

Abstract: A method and a multibeam scanning device for ablation of a surface on a rotating drum by laser engraving with a multi-spot array includes simultaneously emitting laser beams from fiber exits disposed beside one another, dividing up each of the beams, after emerging from the exit in an AOM array having a number of AOMs corresponding to the number of exits, into two or more partial beams modulated independently of one another, imaging the exits with an optical system on the surface, and moving the exits, the AOM array, and the optical system together in a drum axial direction while the surface is scanned by the multi-spot array in a drum circumferential direction to make possible, without increasing the number of fiber lasers, an increase in the number of scanning points of the multi-spot array and a reduction of the space required by the scanning device.

Abstract: An optical microswitch printer head comprising a micromachined optical microswitch array with optical microswitches extending in a main scanning direction. The optical microswitch is based on a variable air gap Fabry-Perot cavity that is defined by two non-absorbing distributed Bragg reflectors. One of the distributed Bragg reflectors is supported by flexible beams so that the length of the Fabry-Perot cavities can be set to be equal to an odd or even multiple of a quarter wavelength of a working optical wave by applying a voltage. As a result, the optical microswitches can be pushed into a transmission state or “on” state for letting a light pass through or a reflection state or “off” state for blocking the light. The optical microswitch printer head can utilize a gas discharge lamp such as a cold cathode fluorescent lamp as a light source.

Abstract: An optical head 1 of an image recording apparatus 10 is provided with a light-source water-cooling jacket 41 for cooling a light source 11 and a device water-cooling jacket 42 for cooling the Grating Light Valve 12 and a light-shield water-cooling jacket 43. The optical head 10 is also provided with a mirror 31 for reflecting a light form the light source 11 in a non-recording status and mirrors 32, 33 for reflecting non-signal light beams from the light valve 12, and the lights from these mirrors are directed to the light-shield water-cooling jacket 43. Further, a refrigerant from a chiller unit goes through the light-source water-cooling jacket 41, the device water-cooling jacket 42 and the light-shield water-cooling jacket 43 in this order. With this constitution, it is possible to efficiently cool all the heat sources and in the optical head.

Abstract: There is provided an image forming apparatus that is capable of securing required printing quality by properly correcting a main scanning scale. In a pixel division modulating process, for each of one or more correction points (at l-th, m-th, and n-th pixels) on each of lines along which scanning is carried out on a photosensitive drum 11 by laser light, the final bit data of pixel-division-modulated pixel data of a pixel immediately preceding each correction point is added to the pixel data of a pixel located at the correction point as the leading bit data of the pixel-division-modulated pixel data of this pixel. The same processing as above is sequentially performed on pixel data of pixels located subsequently to the correction point to sequentially shift predetermined bit data of pixel data of pixels to pixel data of the respective following pixels, to thereby generate pixel data of a new pixel. The generated pixel data of the new pixel is outputted in synchronism with an image clock of a fixed frequency.

Abstract: An object substrate that contains a markingly effective amount of a radiation sensitive marking material such as titanium dioxide is subjected to a patterned pulsed beam of coherent energy having a level of flux density that is at least sufficient to cause the radiation sensitive marking material to change color without degrading the object substrate. The pulsed beam of coherent energy derives its pattern from the instantaneous configuration of individual mirrors on the face of a digital mirror device (DMD) as the energy is reflected from that mirror face. The level of flux intensity at the mirror face is less than the level at which the DMD is at risk of damage or disruption. The level of flux intensity at the object substrate to be marked is sufficient to cause the titanium dioxide to change color, and substantially above the level at which the DMD is at substantial risk of damage or disruption.

Abstract: An apparatus for printing images including an illumination optics (75) that provides uniform area light is disclosed. A prism (370) is located at a first position and receives the uniform area light and refracts the light. A first reflective LCD modulator (90) modulates the refracted light on a site by site basis and reflects the first modulated light to a second position on a media plane. A motor (441) rotates the prism (370) around an axis parallel to the illumination optics to a third position. A second reflective LCD modulator (95) modulates the refracted light on a site by site basis and reflects the second modulated light to a fourth position on the media plane.

Abstract: A laser beam emitted from a laser light source passes through an illumination lens and is thereafter incident upon a total internal reflection prism. The total internal reflection prism bends the laser beam, which is applied to a Grating Light Valve™. The laser beam divided into a number of beams and modulated by the light valve is incident upon a focusing lens. The normal to the light valve forms an angle &thgr;xz with the optical axis of an illumination optical system including the total internal reflection prism and an illumination lens. The normal to the light valve also forms the angle &thgr;xz with the optical axis of a focusing optical system.

Abstract: A method for banding suppression due to vibration in an image forming and/or image receiving apparatus with laser driver utilizes governing equations which relate the on/off time and intensity to velocity and frequency of vibration are disclosed. Using derived formulas, an amplitude and frequency modulation (AM/FM) combination is used to suppress the banding due to vibration. The equation which governs the on/off time (FM) is t1+e sin(2&pgr;ft1)/vn=t0. This transcendental equation can be solved for the required on-time t1 in terms of the nominal on-time t0, e (vibration amplitude), v0 (nominal velocity) and f (vibration frequency). The equation which governs the intensity is H3(t)=v(t)/v0. H3(t) controls the level of irradiance. This method is further extended to multi-temporal vibration frequency and may correct banding due to irradiance modulation.

Abstract: A laser imaging device is described. The laser imaging device includes a laser driver, and a pulse width modulator system. The pulse width modulator system includes a first pulse width modulator having a first operating frequency and a second pulse width modulator having a second operating frequency, which provides to the laser driver a pulse width modulated output signal having a desired modulation frequency greater than the first and second operating frequencies.

Abstract: A method of clocking a video processing circuit by stalling a reference clock signal based on a stall signal from a clock-independent pulse width modulator to produce a video clock signal for use by an image data processing circuit.

Abstract: A color printer (10) for imaging onto a photosensitive medium (140) that contains four or more layers for providing images having an expanded color gamut. Color printer (10) directs polarized light from each of four or more light sources (12) to a spatial light modulator (20) for forming an image to be printed. Modulated light is conditioned as necessary, then focused through a print lens (110) onto photosensitive medium (140). Light sources 12 can be lasers, LEDs, or other suitable components. Embodiments may use a single spatial light modulator (20) shared with each color path or a spatial light modulator (20) in each of the four color paths.

Abstract: Light emitting diode (LED) bar systems have large surface areas and extensive cabling that carry high frequency clocks and data. As the process speeds increase, the higher clock and data rates become an electromagnetic interference (EMI) problem. As the U.S. federal government restricts EMI emissions, many have turned to shielding techniques. However, a spread spectrum technique now may also reduce peak EMI amplitudes by distributing the EMI energy over a range of frequencies. The pixel data may be clocked into a LED bar system with a varying frequency to spread the energy over the range of the modulation. The same total energy is still emitted from the system, but the peak energy at any particular frequency is reduced.

Abstract: A light modulation and exposure system comprising: a light source; a light sensitive media; a two-dimensional light modulator containing a plurality of rows of light valves; means of imaging light source onto light modulator and light modulator onto light sensitive material; means of generating relative motion between image of light modulator and light sensitive material; means of shifting into the first of rows the data to be imaged onto light sensitive material and means of editing data from the first row to subsequent rows of modulator at a rate keeping the image of individual data pattern substantially stationary relative to light sensitive material until data transferred to the selected final rows; this sequence continuing until all data to be imaged has passed through light modulator. The two-dimensional light modulator may be oriented at a rotation relative to the direction of motion of the light sensitive media in a manner conducive to achieving variable resolution levels and half-tone generation.

Abstract: An optical arrangement having a light source, preferably a laser, for generating a light beam (1); at least one acoustooptical deflection device (3) for the light beam (1); and a correction device for correcting beam aberrations produced by the deflection device (3) is configured, in the interest of flexible and reliable correction of aberrations occurring because of the deflection, in such a way that the correction device comprises an adaptive optical system (2). Also described is a method for the deflection of light beams (1) with a light source, preferably a laser, for generating a light beam (1); at least one acoustooptical deflection device (3) for the light beam (1); and a correction device for correcting beam aberrations produced by the deflection device (3), in which an adaptive optical system (2) is used as the correction device.

Abstract: A printer for printing on a light sensitive media (100) includes a light source (10) and optics. Cross array components and array direction components reduce divergence of the beam from the light. The illumination optics flood illuminates a grating modulator with reduced light beams. Modulator sites on the grating modulator array, are individual addressed which imparts a phase change to the reduced light beams. An imaging lens (70) directs light from the grating modulator array onto the light sensitive media (100). The imaging lens (70) includes a first lens element which converts the light into diffracted and undiffracted light; a spatial filter (80) which discriminates between the diffracted and the undiffracted light; and a second lens element which reconstructs an image of the modulator sites.

Abstract: An imaging apparatus (10) adapted for imaging onto a photosensitive medium (160) in one of a number of selectable image formats. A telecentric print lens assembly (132) can be indexed to any one of a plurality of positions along the output optical axis for imaging in a specific format. The print lens assembly (132) can be manually indexed or can be moved by a focus mechanism (80) under the control of a control logic processor (24).

Abstract: An image forming apparatus for forming an image by modulating laser light in correspondence with an image signal. A pulsewidth modulation signal is generated in correspondence with input image data. A laser drive control circuit has a photosensor PD which detects laser light emitted from a laser diode LD and generates a detection current, a resistor which generates a detection voltage corresponding to the detection current outputted from the photosensor PD, a buffer in which the generated detection voltage is inputted, an amplifier which amplifies an output from the buffer, and a constant current source and a switch to add a predetermined current to the detection current for compensation for reduction of output voltage due to offset voltages of the buffer and the amplifier. Control data for controlling maximum and minimum pulsewidths in the pulsewidth modulation signal are obtained based on the detection voltage, and generation of the pulsewidth modulation signal is controlled.

Abstract: A light source modulator and method of modulating a light source use a lower bandwidth input signal during rendering of image data, which is less susceptible to systematic error. The modulation scheme improves the efficiency of use of high speed memory by limiting a number of intensity level transitions to a single transition per output pixel. In conjunction with the limitation of transitions per rendering of each output pixel, data is provided to the modulator that indicates an intensity level to be provided by the modulator and a timing of a transition to that intensity level. In accordance with the exemplary embodiments of the invention, an intensity level may be a minimum intensity level, a maximum intensity level and at least one intermediate intensity level which is intermediate between the minimum and maximum intensity levels.