Abstract: A method of forming authenticated images on image areas of a receiver to form a series of viewable images such as postal stamps including moving a colorant donor element having a plurality of transferable colorants into transferable relationship with the receiver, the colorant donor element includes a representation of an image and marks which authenticate the image having colorant over such representation and marks; and transferring colorants onto the receiver in accordance with the representation and marks in the colorant donor element to form authenticated images in the receiver.

Abstract: In a beam scanning apparatus of an electrophotographic color printer, at least two beam deflectors, each having a deflection disk consisting of at least two sectors and a driving source for rotating the deflection disk, deflect and scan an incident beam. The deflection disk has a pattern formed thereon for diffracting and scanning the incident beam. A plurality of light sources, arranged between the beam deflector and a photoreceptor, emit light to the deflection disk. A beam path changing unit changes a proceeding path of the beam deflected by the respective beam deflectors to proceed toward the photoreceptor. A beam correcting unit, arranged between the respective beam deflectors and the photoreceptor, corrects the input beam having its path changed by the beam path changing unit.

Abstract: Equipment (100) for coating photographic media (14), such as photographic film and paper, has an apparatus (10) for printing bar code indicia (12) on a moving photographic media and a printer means for printing human readable indicia (16) on the media. The printer (20a, 20b) moves into print position along a lateral edge (28) of the media (14) in response to input signals received from a controller (22) having computer readable medium for directing the printing and movements of the printer (20a, 20b).

Abstract: A method for achieving multiple exposure levels for IOI (IMAGE-ON-IMAGE) xerography when imaging a second color through a first toner layer previously developed on the photoreceptive member. In the example illustrated the data from the previous image paths (magenta and yellow) is analyzed. If the signal indicates that a magenta or yellow bit is present, the cyan output bit information passes to the ROS unchanged, or at full intensity. If however, the magenta and yellow are not present, a modified pattern providing an appropriate reduced exposure signal is sent to the ROS. The process of laser attenuation is blended with halftoning logic to avoid image degradation due to the attenuation.

Abstract: In a non-impact recording apparatus that includes a plurality of recording elements, there is provided a source of first data signals representing for each of plural pixels density, size or percentage of coverage for recording. A first look-up table memory is responsive to the first data signals for adjusting the density, size or percentage coverage of each of the pixels with a gamma adjustment related to density development by the apparatus and generates multibit gamma adjusted second data signals. A second look-up table memory generates a third signal related to a characteristic of the recording elements such as for nonuniformity correction. A process look-up table memory is responsive to the gamma adjusted second data signals and the third signals for generating fourth multibit signals relating to exposure on-times for recording pixels by the recording elements. The use of the three look-up table memories results in substantial saving in memory requirements.

Abstract: There is provided an image exposure device in an image recording apparatus which has a simple and compact structure without requiring relatively high assembling accuracy. The light source portion 204 is formed with the plurality of LED chips 208 being arranged in groups. These LED chips 208 which emit light of colors of blue (B), green (G), and R (red) (when described below for each of the colors, the LED chip which emits light of blue is referred to as B-LED chip 208B, the LED chip which emits light of green is referred to as G-LED chip 208G, and the LED chip which emits light of red is referred to as R-LED chip 208R) are mounted onto a substrate 210 along the transverse direction of the photosensitive material 106 (i.e., the main scanning direction) in accordance with the same arrangement rule. Namely, the totaled six rows of LED chips 208 are arranged in a zigzag manner in the plan view of the substrate 210.

Abstract: A color image forming apparatus includes an image forming unit which forms a multicolor image on a second image support by sequentially transferring toner images related to a plurality of colors from a first image support to the second image support in an overlaying manner. A reference position detecting unit detects a reference mark signal every time a reference mark at a reference position on the second image support is sensed during rotation of the second image support. A laser scan start timing control unit controls a laser scan start timing for the image forming unit to start scanning the first image support by a laser beam, based on the reference mark signal. A phase error measurement unit measures a phase error between a line sync signal and the reference mark signal by counting system clocks before the laser scan start timing.

Abstract: A color printer for imaging on an image plane includes: (a) a plurality of light sources, each of the light sources being adapted to provide a spatially coherent, composite beam of light, each of the composite beams including a plurality of spectral components; (b) a single beam shaping optics accepting the composite beams, the beam shaping optics having optical elements adapted to shape said composite beams by a different amount in a scan direction and a cross scan direction, so as to form for each of the composite beams (i) a first beam waist in the cross scan direction of the composite beam and (ii) a second waist in the scan section of the composite beam, the first and second beam waists being spaced from one another; (c) a deflector adapted to move said plurality of composite beams across the image plane, the deflector being located closer to the first beam waists than to the second beam waists; and (d) scan optics located between the deflector and the image plane, the scan optics being adapted to (i) ge

Abstract: A tandem type multi-color image forming apparatus capable of outputting a multi-color image can improve output speed of a monochrome or limited color image output. The image forming apparatus includes a single laser beam source, a plurality of image forming units, and a single polygon body. The polygon body is provided with the plurality of reflector surfaces respectively corresponded to the plurality of image forming units. The apparatus also includes an optical path selecting optical system movable into optical paths of the laser beam reflected from the rotary polygon body for deflecting the laser beam reflected from the rotary polygon body toward selected limited number of image forming units and a control portion for varying operation speed of the selected limited number of image forming units.

Abstract: Disclosed is a photographic printer with bi-directional sweeping of a color CRT to expose a photosensitive medium. Image data from a host system is received by the printer and stored in a data drive system. The data drive system converts the data into a series of rows of dot row data to produce the appropriate image desired. Linear deflection amplifiers sweep the CRT's electron beam across the color phosphor areas on the face of the CRT to expose the medium utilizing the dot row data. The present invention sweeps and writes data bi-directionally, eliminating the retrace period associated with sweeping and writing in one direction, and without any hold periods once printing starts. The data in every other dot row is processed in reverse order so that the dot row data utilized in the reverse writing sweep will be exposed onto the medium in proper relationship to the rows written before and after it.

Abstract: Xerographic printing system using a Raster Output Scanning (ROS) system incorporating a two wavelength (.lambda.) laser diode source for the ROS and a charge retentive member in the form of a belt or drum structure which is responsive to the two wavelengths. The printing system utilizes a CAD development system in addition to two DAD developments during the second pass for enabling the addition of a gamut broadening color resulting in process color imaging with an enhanced gamut.

Abstract: Image forming apparatus makes at least a two color image from an original having some color. The apparatus includes a color scanner which scans the original area-by-area for color content and picks an accent color from available accent colors in the apparatus from the color content analysis. A typical output would be a print in which an original is reproduced in a combination of black and a color picked which color is closest to one of the predominant colors in the original.

Abstract: Thermochromic materials are incorporated into constructions that facilitate accurate reproductions of monochrome or full-color images having multiple gray levels. The invention utilizes thermochromic materials having different transition temperatures to facilitate their selective activation. The materials may be located in a single layer of a recording sheet, or in multiple layers. The invention also comprises thermal printing apparatus useful in imaging the foregoing constructions, particularly those exhibiting hysteresis.

Abstract: In a color image recording system, a color image is recorded on a photosensitive material by causing red, green and blue light beams modulated according to a color image signal to scan the photosensitive material one after another in the order of the red, green and blue light beams, respectively. A photodetector detects only the red light beam, and the red, green and blue light beams are caused to start recording the colorings at respective predetermined times T1, T2 and T3 (T1<T2<T3) after the photodetector detects the red light beam.

Abstract: A method for printing a label on an optical disc using a rainbow graphic cutting system includes storing in a memory a location signal and color information data of the label to be printed on the surface of the optical disc. Corresponding location and data signals from among the location signals and the color information data are selectively output to a laser beam recorder LBR. A label corresponding to the signals output to the LBR is then printed on a surface of the optical disc.

Abstract: An image forming apparatus having a plurality of electron emitting devices and luminescent members are arranged into a matrix formed on one surface of a substrate. As rows of electron emitting devices are successively driven, each luminescent member emits light according to a voltage applied to it or other members in accordance with an image information signal when irradiated with a light beam from one of the electron emitting devices mated with it.

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 photographic recording apparatus capable of being small-sized and simplified in structure and reducing color aberration of an optical system. A refractive index distribution type lens array has a central axis arranged perpendicularly to a light emission direction of a fluorescent luminous tube. Light emitted from the fluorescent luminous tube passes through red (R), green (G) and blue (B) color filters, is incident on the lens array, is reflected on a first mirror and then is guided to a color film, resulting in forming an image on the color film. The fluorescent luminous tube is driven depending on data on R, G and B colors and the whole apparatus is moved with respect to the color film. The color filters are changed over and scan of the color film is carried out three times, so that an image of R, G and B colors may be formed on the color film.

Abstract: In a light beam scanning recording device, a color image is recorded on a recording material by scanning the recording material in a main scanning direction and a sub-scanning direction with light beams of three different wavelengths modulated according to an image signal. A light source which emits a plurality of light beams which form a predetermined number of beam spots on the recording material arranged in the sub-scanning direction is used as the light source for emitting light beams of each wavelength, whereby recording is effected simultaneously along the predetermined number of main scanning lines.

Abstract: An optical printer capable of being decreased in the number of parts, small-sized and weight. A plurality of color filters are selectively alternated or changed with each other with respect to a common luminous section and such changing-over among the filters is carried out using a transfer unit for a print head, resulting in only one set of the luminous section and optical system being required. Also, power required for alternating or changing the filters with each other Is obtained by the transfer unit for the print head without arranging any specific unit.

Abstract: An optical image forming device includes a scanning lens for scanning, in a main scanning direction, eight drawing beams on an image plane. A monitoring beam is scanned repeatedly and simultaneously with the drawing beams in a predetermined scanning range. The eight drawing beams are scanned such that drawing beams adjacent each other in a sub-scanning direction pass a same position in the scanning range on the image plane at a different time. The monitoring beam is scanned prior to scanning of the drawing beam. A scale clock generator is provided for generating scale clock signals identifying positions of the monitoring beam in the scanning range. A modulator modulates the eight drawing beams such that modulations for each of the drawing beams at a same position in the scanning range are synchronized with a timing of a same scale clock signal obtained by the scale clock generator.

Abstract: A halftoning method characterized by two nonaligned halftone screens, one for black and the other for the subtractive primary colors cyan, magenta, and yellow, produces multi-color images on a color laser printer. The black screen is the inverse of, i.e., in reverse fill order to, the subtractive primary colors screen. The halftone pattern is a vertical line screen. In a preferred embodiment, the cells are grouped on hexagonal centers and aligned along X and Y coordinate axes. The dots are grouped in the linear direction of print medium motion. The grouping of dots reduces the effect of halftone screen misregistration, and the cell alignment in X and Y results in fewer high frequency artifacts. Inverting the black screen increases the number of possible chromatic mixed colors that include black, increases color uniformity and reduces the frequency of white "holes" in the printed images.

Abstract: A printer system includes (a) an f-.theta. lens producing lateral color aberration; (b) three laser light sources, each producing a light beam for use with said f-.theta. lens; and (c) modulators modulating these laser light beams at different data rates from one another. The ratio of the different data rates is being used to compensate for the lateral color aberration produced by the f-.theta. lens.

Abstract: In a color image forming apparatus, a plurality of color images of component colors are combined to form a full color image. These images of the component colors are overlapped on an intermediate recording medium, and are then transferred to a transfer medium. Control circuitry reduces the amount of time required to form the component color images on the intermediate transfer medium, and to prevent an abnormality such as an out-of-phase or pull-out of a closed loop control circuit for controlling such a formation of the component color images. This may be achieved by abruptly changing a phase of a motor synchronizing signal. Further, for a period of time after the motor synchronizing signal is abruptly changed, a gain of an amplifier in the motor control circuit can be reduced, an abnormality detection in the motor control circuit can be reduced, the motor control circuit can be placed in an open loop state, or an addition or subtraction signal can be input to the closed loop motor control circuit.

Abstract: The present invention provides an optical exposer unit having a large space for containing black toner, and a color image forming apparatus comprising the optical exposer unit. In an optical exposer unit, first and second laser beams, which are reflected on the respective reflection surfaces of a polygonal mirror unit and passed in a direction farther from a photosensitive drum than an optical axis of an optical system including first to third image-forming lenses, are reflected on second mirrors, and mutually crossed each other so as to be guided to the photosensitive drum corresponding to third mirrors. Thereby, a sufficient space is provided to the surroundings of a black image forming section. Therefore, the space for containing black toner can be largely ensured as compared with the space for containing the other color toner.

Abstract: In order to improve an apparatus for generating an image in an image plane that is visible, in particular, for a human eye, comprising a radiation source which generates an image via an optical projection means by building up at least one row of image spots during an image build-up cycle by illuminating individual, adjacently located image spots and periodically repeating the image build-up cycle, so that it is possible to generate images as simply and, therefore, also as inexpensively as possible, it is suggested that a row of light sources comprising a plurality of semiconductor emitters be provided for the illumination of the image spots of the row of image spots, that the optical projection means associate each exit spot for the radiation of each semiconductor emitter with at least one of the image spots and that the optical projection means simultaneously image the exit spots of all the semiconductor emitters of the row of light sources onto the image spots associated therewith.

Abstract: In a photo printer, signal components D1', D2', and D3' representing low-saturation picture elements are obtained from image signals D1, D2, and D3. Shadow points D1s, D2s, and D3s and highlight points D1h, D2h, and D3h in the signal components D1', D2', and D3' are calculated. A set of signal components (D1", D2") is obtained by grouping signal component pairs (D1', D2'), each of which corresponds to a single picture element, and in which the signal components, each constituting one of counterparts in each pair, have an identical value, and replacing the signal components, each of which constitutes the other counterpart in each of the grouped pairs, by their mean value. A calculation is made to find the relationship between the densities of two colors from the set of the signal components (D1", D2"), the shadow points (D1s, D2s), and the highlight points (D1h, D2h).

Abstract: A non-impact recording apparatus and method is described for recording pixels on a recording medium by recording sub-pixel recording portions of the pixel represented by a multibit recording data signal having a most significant data bit and a least significant data bit in a series of consecutive subline recording intervals. The apparatus includes one or more recording elements that are drivable by driver currents to generate recordable output signals such as light or ink droplets or heat. A driver provides driver currents to each recording element during plural subline recording intervals to record the pixel. One driver current is provided during one subline interval for one duration that is different than a second driver current that is provided during a second subline interval for a second duration.

Abstract: An image recording apparatus of the present invention comprises: an image processing means for compensating the color and gradation of an inputted color image; a monochromatic CRT; a display means for successively inputting color images, having a plurality of colors, into the monochromatic CRT, and for displaying a plurality of images on the monochromatic CRT as monochromatic images; an optical system for forming the monochromatic image, displayed on the monochromatic CRT, onto a color photographic paper; a plurality of color filters, which are selectively inserted between the monochromatic CRT and the color photographic paper, and convert the monochromatic image into a plurality of monochromatic color images; an exposure luminance setting means for each separation color; and an emitting luminance control means.

Abstract: Apparatus and method for performing a photographic printing in which photographic signals are separated into a black signal and a chrominance signal and gradating is performed on each one of the black signal and the chrominance signal.

Abstract: In a color image forming apparatus, wherein plural toner images are superimposed on the photoreceptor during a single rotation of the photoreceptor by a plurality of charging devices, image exposing means and developing means, each of the plurality of image exposing means comprises an array-shaped plural elements aligned in the axial direction of the photoreceptor and the color image forming apparatus further comprises heating means or heat absorbing means provided for each of the plurality of image exposing means and control means for controlling a temperature of each of the plurality of image exposing means independently of others by the heating means or the heat absorbing means.

Abstract: A method of printing human readable information on a CD having a substrate, a record layer over the substrate, and a reflective layer over the record layer includes the steps of providing a colorant donor element in transferable relationship with a surface of the CD over the reflective layer; raster scanning a light beam across the colorant donor element to cause the transfer of human readable colorant pixels onto such surface; and continuously raster scanning the light beam without any non-printing or free fly time during the transfer of such human readable colorant pixels.

Abstract: A system that permits the plotting of any combination of several colors in one pass. Three differently colored light sources are provided, and thus one, two or three colors may be plotted at the same time. An apparatus is provided for causing relative movement between the scanning head and the substrate along each of the two axes of the substrate. Preferably, the first axis is disposed circumferentially about a cylinder, on which the substrate is situated, the cylinder having a central axis, and the second axis is disposed approximately parallel to the central axis. The system includes deflection means, preferably acousto-optical modulators, for deflecting along a path a portion of each beam of light by an amount dependent upon the frequency of a signal that is present at the deflection means' input.

Abstract: A color imaging apparatus, for forming a beam of light having three separate color components for image recording on a photosensitive member, includes red, green, and blue color component light channels, wherein the green light channel is formed by an LED of Gallium Nitride (GaN) material. In another similar color imaging apparatus the green light channel is formed by an LED of Indium Gallium Aluminum Phosphide (InGaAlP) material.

Abstract: Full color, single pass and two-pass imaging processes using black, magenta, cyan and yellow toners and Non-interactive Development without fringe field development. Corona discharge is utilized for voltage leveling certain developed images prior to their passage through DAD developer housings. A Raster Output Scanner (ROS) used for creating the latent electrostatic images is also used for voltage leveling of images developed on the first pass of the two pass imaging process in order to remove certain other images for eliminating fringe field images as well as other undesired images.

Abstract: An electrophotographic printer includes a plurality of recording heads connected in series in a closed cooling circuit. Each of the recording heads includes a linear array of light-emitting diodes (LEDs) on a common thermally conductive LED carrier bar. The carrier bar carries a series of modules, each module containing N LEDs with their associated drivers. The carrier bar is provided with a U-shaped duct inside a thermally conductive body which is in thermally conductive contact with the carrier bar. The duct extends between a fluid inlet and a fluid outlet and has a cooling fluid such as water flowing therethrough.

Abstract: A method and apparatus for measuring colorimetric, gloss and registration data on a substrate exiting a printing machine. A detector using a series of red, green, and blue filters collects image data and maps the collected data to absolute color coordinates. The apparatus is factory calibrated to the specific colorants used in the printing machine. Gloss measurements are made using the same apparatus. Registration data between the various color separations is also obtained and feedback delivered to the various imaging modules. The detector allows on the fly data to be obtained and machine specific corrections to be made.

Abstract: Information is recorded on a heat-sensitive recording material including a photo-thermo conversion agent which converts supplied light energy into heat energy, a developing agent and a color forming agent which is encapsuled in micro-capsules whose permeability to materials increases with increase in said heat energy and forms a color by reaction with the developing agent. The photo-thermo conversion agent is localized in and/or on the micro-capsules. The heat-sensitive recording material is heated by supplying the heat-sensitive recording material with heat energy less than energy necessary to cause the heat-sensitive recording material to form a color. A light beam modulated according to the information to be recorded is caused to scan the recording material.

Abstract: A fibre laser (2) is used in data-recordal, such as dye diffusion thermal transfer printing. The fibre laser output (3) is modulated and scanned across a recording medium (4) of adjacent dye donor and receiver ribbons by a modulator (20) and galvanometer (16), so that an image is produced line-by-line in the medium (4) as it passes between spools (19). The fibre laser (2) may comprise a single-mode, neodymium-doped lasing core (5), a multimode pump core (6), an outer cladding (7), and a dichroic mirror (8) at each end, and may be pumped by beams (10) from laser diodes (9) coupled to the pump core (6) by optical fibres (11) and a lens (14). Instead of using a galvanometer (16), the output end of the fibre laser (2) may be moved itself across the recording medium (4), and/or a plurality of the fibre lasers (2) may be bundled together in a one or two dimensional array.

Abstract: An exposure device includes: at least three light-emitting elements for respectively emitting light of mutually different colors and forming a slit beam; an optical shutter array in which a plurality of optical shutter elements for allowing the slit beam incident thereupon to be transmitted therethrough or shut off as the optical shutter elements are opened or closed, and being provided in a number corresponding to the number of pixels constituting a row of pixels in a scanning line of the photosensitive material along a direction corresponding to the cross-sectionally longitudinal direction of the slit beam; and a control member for controlling the light-emitting elements and the optical shutter array such that an amount of exposure applied to a predetermined pixel on the photosensitive material becomes substantially equal to an amount of exposure of a corresponding pixel of color image data.

Abstract: The present invention provides a method and a device for color laser marking for attaining visible coloring without drastic modification of conventional devices and without using dyestuffs. To this end, in a color laser marking method, a workpiece (10) is a synthetic material made from organic and inorganic materials and, when irradiating laser light, patterns in different colors can be obtained by varying the received light intensity on the workpiece (10). In addition, in a color laser marking device, when the workpiece (10) is a synthetic material made from organic and inorganic materials, a controller (11) outputs laser irradiation intensity varying signals to at least one of laser irradiation intensity varying means, such as a laser oscillator (1).

Abstract: A color image formation system in which transfer means for sequentially receiving plural color images is idled if raster image data for a color has not yet been converted from a page description language into the raster image. A page description language or other code data for a first color is converted into a raster image of the first color and an electrophotographic process is commenced whereby a laser beam is modulated in accordance with the raster image of the first color and the image formed by the modulated laser beam is transferred to rotatable transfer means. After image formation in the first color is complete, code data for the second color is converted into raster image data. If conversion of the second color is not yet complete but the transfer means has rotated to a position where it is ready to receive the second color, the transfer means is idled by continued rotation thereof and forcibly restricting laser beam illumination whereby the transfer means is fed blank to a predetermined position.

Abstract: A method and apparatus for printing on to a photosensitive material. The apparatus includes a light source for producing light composed of at least two colors, a collimator for collimating the light produced by the light source so as form a beam of light, a modulator for modulating the beam of light in accordance with one of the predetermined color components, a filter for filtering out the color component which has been modulated, and a beam directing device for directing the modulated colored filter beam of light onto a photosensitive material.

Abstract: A copier/printer system includes an image scanner for scanning a document and providing, after a compression step, digital image scanning signals, P.sub.1, that may be communicated to a computer system for display and editing or alternatively communicated to a grey level printer having a magnetic tape memory. The computer system may be used to display the scanned image for editing by an operator and is coupled to the printer so that the edited image signals, P.sub.2, which may be the scanned signals and a common page description language to modify its usage, may be printed by the printer. The edited image signals, P.sub.2, may be sent to the printer over a suitable network. The printer includes image processing electronics for transforming the edited data, P.sub.2, into device independent data signals, P.sub.3. Such signals may be received by printers of the same type; i.e., those employing similar process and halftone algorithms. The signals, P.sub.

Abstract: This invention relates to a laser marking method which comprises heating a base article having on its surface a thin film of a laser marking composition containing a color former and a color developer having a melting point of 200.degree. C. or above, and then applying laser light to the thin film. The method of this invention is capable of no-break marking with vivid color development by application of laser light, without causing discoloration of the ground even under a condition of 120.degree. C. or above.

Abstract: A minimum value of input color image signals (R, G, B) is extracted, difference signals between the extracted minimum value and the input signals (R, G, B) are calculated, and matrix conversion is executed based on the difference signals, thereby obtaining desired output color image signals having a color reproduction range different from that of the input color image signals.

Abstract: A color printer has means for setting toner image forming areas in the paper sheet convey direction in respect of respective colors, means for detecting a reference position on a photosensitive belt, and image formation start position setting means responsive to the reference position to set a toner image (electrostatic latent image) formation start position in the rotation direction of the photosensitive belt. When the paper sheet length is longer than the outer peripheral length of an intermediate transfer member, the image formation start position setting means sets, for colors other than the final color, a printing area which is shorter than the outer peripheral length of the intermediate transfer member and sets, for the final color, a printing area which begins immediately after a seam position of the photosensitive belt and conforms to the paper sheet length.

Abstract: A color forming image apparatus for forming a multicolor image by forming an image of each color including a transfer member holder for retaining a plurality of transfer members. The image former forms the image on the transfer member based on an image signal from an external source. A detector detects information relating to a status of the transfer member held in the transfer member holder and sends the information to the external source.

Abstract: Laser color printers include multiple laser sources formed of either diode lasers or laser diode arrays emitting light beams of different wavelengths, and an optical arrangement. The optical arrangement independently processes each of the light beams to provide a separate predetermined sized collimated light beam, and then focuses and scans the light beams over a printing media that prints separate colors for each different wavelength of light. Where different sized collimated light beams are required to match a printing media, a separate zoom lens is used is used in the optical arrangement to independently reshape each of two orthogonal cross-sectional directions of a separate one of the light beams before being properly sized at the output thereof.

Abstract: A color printing system including thin film electroluminescent (TFEL) edge emitter devices and an electronic interface for driving the TFEL devices. The TFEL edge emitter devices form a multi-color TFEL edge emitter structure operable for emitting a plurality of different colors of light onto a media. The electronic interface receives gray scale data for pixels and converts it into a serial data stream used to drive pixels in the TFEL edge emitter structure. The electronic interface further includes a compensation memory for compensating for pixel variations in the TFEL structure. The compensation memory can be periodically recalibrated "in place" during the life of the printing apparatus.