Abstract: A reliable, low cost system for generating precisely aligned pixel clock and index signals for a digital scanning or printing system is based on a novel single channel encoder pattern detected with a single sensor. The signal output of the sensor representing the encoder pattern is processed with phase locked loop based circuit to generate pixel clock and index signals of known and guaranteed phase.

Abstract: There is described a tray-like cartridge for supplying thin delicate sheets of dye done film in a thermal printer. The cartridge has a slidable lid which normally covers a portion of the cartridge containing a factory-supplied package of film. The lid has a specially shaped window through which sheets of film may be drawn one-by-one from the cartridge for use in the printer. When the cartridge is not in the printer, the lid window is closed. This keeps the film free of dust and protects it from damage. The shape of the lid and its window act in conjunction with a film feeding mechanism of the printer to insure absolute reliability in the separating and feeding of individual sheets of film. Another portion of the cartridge serves as a waste bin for used sheets of the film.

Abstract: A film registration gate assembly has a gate with focal positioning location for focal positioning of an image frame of a strip film with edge perforations. Undersized first and second pins enter a pair of transversely aligned perforations to register the image frame with the positioning location. An undersized third pin enters a third perforation spaced along the film from the second pin and then pulls the film obliquely to a reference line extending between the first and second pins to nest against the first and second pins the perforations thereat and register the image frame precisely at the aperture. A plate with a window registering with the image frame and aperture clamps the film against the gate. The window, positioning location and image frame are of corresponding size and shape. The pins register the image frame precisely with the positioning location, and the plate maintains the image frame in precise focal position thereat.

Abstract: A film registration and ironing gate assembly has a gate with a positioning location or aperture for focal positioning of an image frame of a strip film with edge perforations. Undersized first and second pins enter a pair of transversely aligned perforations of the film to register the image frame with the aperture. An undersized third pin enters a third perforation spaced along the film from the second pin and then pulls the film obliquely to a reference line extending between the first and second pins to nest against the first and second pins the perforations thereat and register the image frame precisely at the positioning location or aperture. A pair of flexible bands extending along the film edges adjacent the positioning location move progressively into incrementally increasing contact with the film to iron it and clamp its perforations against the gate. The pins register the image frame precisely with the positioning location, and the bands maintain the image frame in precise focal position thereat.

Abstract: An imaging system comprising a source of light movable with respect to a writing element and projectable thereon to generate an image, a focusing system is provided for focusing a light source which generates a first beam of light of a wavelength selected to be actinic with respect to the writing element. At least a portion of the first beam of light is absorbed by the writing element. The apparatus comprises a material supply to automatically supply donor sheets and receiver sheets independently to a writing platen or drum, and to selectively load and unload the donor sheets from superposition with the receiver sheet without disturbing the registration of the receiver sheet. The material supply includes a carousel assembly with a plurality of roll supplies of the donors and the receivers. A single drive is provided for feeding material from whichever roll supply on the carousel is at the feed station.

Abstract: A method is disclosed for the calibration of a multichannel printer. The printer comprises a plurality of diode lasers which are modulated in accordance with an information signal. Radiation from the diode lasers is imaged onto a receiving medium such as a thermal print medium. The thermal print medium is supported on a drum which is rotatable about an axis. In order to balance the output from the diode lasers, test patterns are formed on the receiving medium with each of the lasers using known power inputs. The density of each of the test patterns is measured, and the density values obtained are correlated with the input power levels for each of the lasers. The measurement of densities produced by a single laser is facilitated by slowing the print head down by a factor of the number of lines normally printed and writing with one line source at a time.

Abstract: An imaging system having a source of light movable with respect to a writing element and projectable thereon to generate an image, a focusing device is provided for focusing a light source which generates a beam of light of a wavelength selected to be actinic with respect to the writing element. At least a portion of the beam of light is absorbed by the writing element. The apparatus includes an imaging drum for holding donor sheets and receiver sheets in registration on the drum. A registration device including a non-reflective indicia on the surface of the drum facilitates the proper registration of the donor and receiver sheets.

Abstract: An improved image transparency or slide is disclosed in which certain small image anomalies are rendered invisible to the human eye in an image projected from the slide. A diffusion layer spaced a finite distance from an image coating of the slide causes disappearance of the anomalies in a the projected image. In applications requiring particularly high sharpness, the image is formed on the slide using image enhancement techniques which produce exaggerated edge effects in the image. When these exaggerated edge effects are diffused in a projection, the projected image is sharp and free of the anomalies.

Abstract: A thermal printer is disclosed which is adapted to form an image on a thermal print medium of a type in which a donor element transfers dye to a receiver element upon receipt of a sufficient amount of thermal energy. The printer includes a plurality of diode lasers which can be individually modulated to supply energy to selected dots on the medium in accordance with an information signal. In order to increase the efficiency and versatility of the printer, the print head of the printer includes a fiber optic array having a plurality of optical fibers coupled to the diode lasers. The thermal Print medium is supported on a rotatable drum, and the fiber optic array is movable relative to the drum.

Abstract: Apparatus and associated methods employed therein, for objectively providing an accurate appearance match between images produced by two imaging systems (e.g. a target image produced by one such system, e.g. a press sheet (140) generated by a printing press (130), which is to be matched by a replica image produced by another such system, e.g. a proof (120) generated by a color halftone proofing system(110)) and thereby calibrate the performance of one imaging system, e.g. the proofing system, to that of the other system, e.g. the printing press. Specifically, measurement data, such as illustratively densitometric N,R,G,B measurements, is obtained for the same portions of the press sheet and proof. This data is then transformed into a color space which encodes color information in a pre-defined manner that approximates color preferences inherent in human color interpretation.

Abstract: An apparatus for generating a high resolution image from an image sensor having a plurality of pixels with a preselected pitch with means for dithering the image sensor. The movement of the image sensor causes the pixels to map a new area of an image without overlap of a previously mapped area. The present invention provides a simple, economic, and reliable mechanism using cascaded levers for dithering the sensor or the input image.

Abstract: A technique for use in a direct digital color proofing (DDCP) system (500) for printing a "modelling" color(s) in a halftone color proof image such that the modelling color simulates a ("special") color that does not lie within a gamut of colors reproducible through only primary color (e.g. cyan, magenta, yellow and black) halftone printing. Specifically, a wide range of such modelling colors can be produced by independently and appropriately setting dot size, particularly in combination with solid area density, for the halftone dots (110, 120, 130, 140) produced for different primary colors and then printing the resulting dots on an overlaid dot-on-dot basis with proper registration. Appropriate dot gain and density look-up tables (230, 720; 240, 940) are respectively used to transform continuous tone separation values and bit-mapped data to vary dot size and solid area density of these halftone dots for each such primary color prior to printing these dots using a proofing engine.

Abstract: A monolithic multi-color laser comprising a semiconductor laser formed on a substrate for lightwave generation. Means is provided for exciting the laser and means is provided on the substrate adjacent the laser to double the frequency of the lightwave emitted from the laser to produce output lightwaves having wavelengths in the photo-sensitive region of conventional silver halide photographic material. Further, an individually controllable frequency matched lightwave modulator is mounted on the substrate and is arranged to individually control the output lightwave in response to a data signal.

Abstract: An imaging system comprising a source of light movable with respect to a writing element and projectable thereon to generate an image, a focusing means is provided for focusing a light source which generates a first beam of light of a wavelength selected to be actinic with respect to the writing element. At least a portion of the first beam of light is absorbed by the writing element. The apparatus comprises means to automatically supply donor sheets and receiver sheets independently to a writing platen or drum, and to selectively load and unload the donor sheets from superposition with the receiver sheet without disturbing the registration of the receiver sheet. Also included are components which contribute to the quality of the images generated, such as relatively inexpensive, low jitter transports and drives for the writing head and imaging drum.

Abstract: This invention shows a mounting for an image sensor in an optical path wherein the axis of the path is perpendicular to the surface of the image sensor so that every pixel on the image sensor is rigidly positioned with respect to the direction of the optical path but is free to undergo small dithering movement transverse to the direction of the optical path. The mounting comprises a platform (64) to which the image sensor is mounted, and at least three wire legs (84) having sufficient rigidity that they support the image sensor without stretching or buckling, each wire leg being attached to the platform at one end and attached to a base plate at the other end. The wire legs are disposed substantially parallel to the optical path so that the platform and the image sensor are movable transversely of the optical path upon the application of a transverse force to the platform without movement along the direction of the optical path.

Abstract: A tile-oriented technique and associated apparatus for manipulating a continuous tone (contone) image through image rotation, anamorphic scaling and digital halftone screening for use in illustratively implementing a page description language. Specifically, an incoming contone image is first partitioned into aligned non-abutting tiles (e.g. 215.sub.1, 215.sub.2, . . . , 215.sub.9). Overlapping blocks (e.g. 217.sub.1, 217.sub.2, . . . , 217.sub.9) are then defined which will hold output data for corresponding tiles. Two dimensional sampling increments, in fast and slow scan directions, are defined to relate movement between successive pixels in an output block to movement between corresponding pixels in the contone image. Similar, though independent, sampling increments, also in the fast and slow scan directions and based in part upon screen angle and screen ruling, are defined for movement between successive pixels in a halftone reference cell.

Abstract: Apparatus and associated methods for providing accurate tone reproduction in an output image, specifically in terms of dot gain curve shape and scale, through a DDCP imaging chain (such as that implemented by a raster image processor (200), particularly a screening process (460) occurring therein, and a marking engine (130)) used in a direct digital color proofing (DDCP) system (100), based upon "Process" data (600) associated with that imaging chain and customer defined ("Aim") data (500). Specifically, monotonically interpolated, e.g. using monotone piecewise cubic interpolation, "Aim" and "Process" data for "all possible" inputs are determined from corresponding input "Aim" and "Process" data and then combined to yield a customized dot gain look-up table (460) that, for a given operating condition, reflects the "Aim" data modified by the inverse of the "Process" data, i.e. the latter reflecting the native dot gain characteristic of this imaging chain which occurs at that condition.

Abstract: An imaging system comprising a source of light movable with respect to a writing element and projectable thereon to generate an image, a focusing system is provided for focusing a light source which generates a first beam of light of a wavelength selected to be actinic with respect to the writing element. At least a portion of the first beam of light is absorbed by the writing element. The apparatus comprises a material feeder to automatically supply donor sheets and receiver sheets independently to a writing platen or drum, and to selectively load and unload the donor sheets from superposition with the receiver sheet without disturbing the registration of the receiver sheet. Also included are components which contribute to the quality of the images generated, such as relatively inexpensive, low jitter transports and drives for the writing head and imaging drum.

Abstract: A method and apparatus are disclosed for the calibration of a multichannel printer. The printer comprises a plurality of diode lasers which are modulated in accordance with an information signal. Radiation from the diode lasers is imaged onto a receiving medium such as a thermal print medium. The thermal print medium is supported on a drum which is rotatable about an axis. In order to balance the output from the diode lasers, test patterns are formed on the receiving medium with each of the lasers using known power inputs. The density of each of the test patterns is measured, and the density values obtained are correlated with the input power levels for each of the lasers. The measurement of densities produced by a single laser is facilitated by slowing the print head down by a factor of the number of lines normally printed and writing with one line source at a time.

Abstract: A method and apparatus are disclosed for producing thermal slide transparencies. Receiver elements mounted in open slide frames are positioned on a platen in an exposure station, and donor elements in the form of cut sheets are positioned over the receiver element prior to exposure. A laser beam, modulated in accordance with an information signal, is scanned across the surface of the donor element in order to provide the necessary thermal energy to effect a transfer of dye from a donor element to a receiver element. The elements are moved in a cross-scan direction during exposure by means of a lead screw connected to the platen. In order to form a color slide, successive donor elements of the necessary colors are moved into register with the receiver element. After the image has been formed on the receiver element, the receiver element is moved to a fusing station where the image is fixed. Sections of the slide frame are then joined together to complete the slide.