Abstract: Method to improve the printing quality at reproduction of half-tone originals by means of printers of the type, in which a number of dots are brought together in a cell (pixel). A minimum of two dots form a cell where each dot in the cell is controlled individually with respect to the size and/or the color value. The dots form a pattern in each cell, which is variable with respect to the number of dots, the dot size and/or the dot color value.

Abstract: A digital ASIC inputs pixel data thereto and an analog ASIC inputs the output signal of the digital ASIC thereto. A combination of the digital ASIC and the analog ASIC controls a semiconductor laser so as to pulse-width-modulate and amplitude-modulate the light emitted by the semiconductor laser that may be pulse-width-modulated and amplitude-modulated. The digital ASIC comprises a reference pulse generator having delay time control unit and a pulse width generator for generating a plurality of different pulse widths using pulses having a plurality of phases generated by the reference pulse generator. The analog ASIC comprises control/modulation unit for controlling the semiconductor laser so as to pulse-width-modulate and amplitude-modulate the light emitted by the semiconductor laser using the plurality of different pulse widths generated by the pulse width generator.

Abstract: The dimensions of a magnetized pattern formed on a recording medium are varied, thereby causing the amount of toner attracted to the recording medium to vary, and thereby adjusting the printing density. This type of variation of the dimensions of the magnetized pattern is preferably achieved by varying the pulse width, that is, the duty cycle, of the recording clock which is supplied to a latent image recording circuit. This printing density adjustment method enables stable adjustment of the printing density.

Abstract: When binary image data is outputted from a FIFO buffer, a first black pixel counting circuit counts black pixels in a 3.times.3 matrix having a target pixel at its center to produce a count value BK2. Similarly, a second black pixel counting circuit counts black pixels in a 17.times.9 matrix to produce a count value BK1. Based on the count values BK1 and BK2, a value indicating the dot diameter is outputted from the output value table while a look-up table and the output value table are sequentially referred to. Setting is so made that the dot diameter becomes smaller as the count values BK1 and BK2 decrease.

Abstract: An electrophotographic process and arrangement for generates a macro-charge zone inkable by toner applicators and delimited by an inking limit (EG) having an adjustable contour on a photoconductor of a printing or copying machine, using at least one exposure-variable and position-variable controllable light source (LED), such as an LED comb or laser. By controlling the exposure of the light source and its radiation position on the photoconductor and by controlling a bias voltage (UB) which can be applied between photoconductor and toner applicator, an electrostatic potential relief (UR) made up of individual adjacent micro-charge zones (UM) of exposure-dependent size is generated on the photoconductor and the inking limit (EG) is defined, the contour of the inking limit being determined by the bias voltage level (UB) on the potential relief (UR).

Abstract: An ink amount correction system is provided in a color image printer system for printing a full color image by mixing yellow, magenta, cyanogen and India ink amount signals. The ink amount correction system includes: a plurality of color ink amount correction circuits which include a quantization section for quantizing a color ink amount indicative signal representative of the amount of an ink of a predetermined color corresponding to each of picture elements of a primary color image; an error calculating section for calculating a quantization error between the input and output of the quantization section, to output as a quantization error signal; and a feedback correction section for adding the quantization error signal derived by the error calculating section, to the corresponding color ink amount indicative signal of the surrounding picture element, for correcting the ink amount indicative signal.

Abstract: A half-tone image recorder in which input digital data is represented by a plurality of bit data for each pixel. A data conversion device outputs digital data indicative of a recording-start position and a recording-end position, based on the input digital data. A recording device such as a laser printer records an image in accordance with the output digital data from the data conversion device. The data conversion device controls a first value of the digital data indicative of the recording-start position and a second value of the digital data indicative of the recording-end position so as to change a black-area growing direction within one pixel in the recorded image. This results in the recordation of a high-quality half-tone image without conspicuous vertical stripes and without conspicuous white stripes in the main-scanning direction of the recording device due to pitch irregularity.

Abstract: Bit data of a received video signal is partially converted into a first signal representing a data sequence corresponding to the resolution of an LED head. The first signal is transmitted to the LED head in the form of a real printing data signal that is to be printed on a basic raster line in synchronism with a line timing signal. The remaining bit data of the received video signal, which are not converted into the first signal, are converted into a second signal representing another data sequence, and then stored in a line buffer. The second signal stored in the line buffer is transmitted to the LED head in the form of a real printing data signal that is to be printed on an additional raster line in synchronism with an additional line timing signal. The LED head drive energy with which the basic raster lines are printed and another LED head drive energy with which the additional raster lines are printed are set independently of each other. The LED head may be provided with such a resolution function.

Abstract: To print an image having a 300 x 600 dpi effective resolution with an ink jet printer that has a 300 dpi resolution, the method increases a resolution or density of the pixel image along the raster scan axis. The pixel image is thinned and raster scanned with the ink jet printer to visibly reproduce the pixel image at the 300 x 600 dpi resolution. The pixel image may be thinned based on a checkerboard pattern while maintaining and enhancing edges.

Abstract: A recording apparatus of the electrophotographic system such as a laser beam printer is provided. An image processing apparatus which is connected between a recording control section and a recording mechanism section of such a recording apparatus is also provided.

Abstract: A non-impact printer apparatus includes a printhead having a plurality of recording elements. Nonuniformities in emission characteristics of the recording elements are corrected using look-up tables (LUT) assemblages that include a first LUT wherein the recording elements are binned in accordance with bin values associated with their emission characteristics and a second LUT wherein bin values, output from the first LUT are used to address various tables providing exposure correction. The first and second LUTs are advantageously dual port RAM devices that allow operation during printing while simultaneously allowing loading of data into the tables for use for subsequent printing. Thus, process conditions may be continually monitored and correction data updated without delaying of current printing which may occur using correction data already stored in the LUT assemblages.

Abstract: An electrophotographic image recording apparatus that forms an electrostatic latent image so that the uniformly charged surface of a photoreceptor is scanned for its exposure with a beam spot of a light beam generated according to image information, to discharge the surface of the photoreceptor up to a medium potential. The electrophotographic image recording apparatus includes a light beam generator capable of varying an amount of light beam and a light intensity distribution pattern of a beam spot on the surface of the photoreceptor, an intensity distribution pattern controller for controlling the light beam generator according to the image information of peripheral pixels, to vary the intensity distribution pattern of the beam spot on the surface of the photoreceptor, and a light beam output controller for controlling the light beam generator to put the exposure energy on pixels, exposed to the beam spots of intensity distribution patterns, at a predetermined value.

Abstract: Toner is conserved in printer (1) under operator control by changing the final modulation for each bit in a bit map depending on whether the bit is an edge bit or an internal bit in the character being printed. Since only the final modulation is affected, processing speed and efficiency are not degraded. The operator can select various degrees of internal gray and internal white. Some levels of gray may be satisfactory for some final correspondence.

Abstract: An image forming method and apparatus which forms an image by using PWM to properly reproduce tones at a low density in the image formation, and attain a high-quality image without reducing the resolution in the dot formation corresponding to a high density value. A color laser beam printer using the PWM to which the present invention is applied forms a latent image onto a photosensitive drum by the laser beam irradiated from a semiconductor laser. The waveform of a chopped wave signal used in the PWM is set to be unique with respect to each color component, and be asymmetrical to the center of each pixel represented by the image signal in synchronization with the waveform of the chopped signal. Accordingly, the interval of dots formed to correspond to each color component is relatively wide when the density value is small, while the interval is relatively narrow when the density value is large.

Abstract: An image processing system for converting an input pixel into n subpixels P1, P2, . . . , Pn, said system includes a comparator for comparing density threshold values D1, D2, . . . , Dn (where D1<D2<. . . <Dn) corresponding to the subpixels P1, P2, . . . , Pn with a density of the input pixel, Din; and a density setting unit for setting subpixels P1, P2, . . . , Pk corresponding to density threshold values D1, D2, . . . , Dk of the density threshold values D1, D2, . . . , Dn (where k<n) less than the density Din to a high density, setting subpixels Pk+2, . . . , Pn to a low density, and setting subpixel Pk+1 to an intermediate density.

Abstract: An image forming apparatus including a bit map data generating section for generating binary dot data for each color from image data, an image memory for storing the dot data, an edge dot discriminating section for discriminating edge dots positioned in an edge section, such as a curved-line section, a slanted-line section of characters, graphics, photo images, etc. in dot data for black stored in the image memory, and a dot modulating circuit for modulating the dot data so that the edge dots and printing dots other than black ones become smaller than black printing dots other than the edge dots. With this arrangement, since linear tone can be obtained even in a section with a deep color, excellent tone can be obtained in multi-color printing such as full-color printing. Therefore, reproducibility of tone of binarized image data can be improved, and jaggedness in an edge section can be improved so as to have a smooth line.

Abstract: A printing device (10) is commanded to print a reference set of intensity values from almost white or highlight regions through almost dark or shadow regions. A measuring device (12) measures the actual outputted printer intensity levels from the printing device (10). An interpolator (14) interpolates the printer intensity levels into a best fit smooth curve plotted against the reference set of intensity levels which produces a non-linear function. A mapping means and converter (24a, 24b) calculate a set of fractional intensity values and densities which produce a linear function when mapped with the printer intensity levels. A dot area parameter calculator (28) calculates a set of dot parameters defining a configuration of a halftone dot required to fill an area within the halftone cell corresponding to each intensity level. For each position of each halftone cell, a measurement processor (30) determines a distance between a current scan position (a,b) and a nearest edge defined by the dot parameters.

Abstract: An image forming apparatus with a solid-state scanning optical print head reproduces tones by an intensity modulation method, corrects light dispersion of each element by a pulse modulation method, and corrects fluctuations in sensitivity characteristics of a photosensitive member by switching the drive current value of maximum light exposure.

Abstract: To create a latent electrostatic gray scale image on a charge receptor, a gray scale generator determines a charge distribution for a unit cell having at least two pixels. A charge manager then determines the amount of charge to be placed in each pixel. More specifically, the charge amount for a first ON pixel in the unit cell is assigned a relative full charge amount. The charge amount in each succeeding ON pixel is determined such as to ensure faithful reproduction of gray scale for any given ratio of pixel size to charge receptor thickness. To increase the developability in proportion to the gray scale, the charge manager manages the charge amount of succeeding ON pixels to be a smaller amount than the first ON pixel.

Abstract: In a printer, a controller keeps track of the imager's operation. The original image is transferred into a continuous tone image by using a tone reproduction curve. That signal is encoded into gray pixel data by a halftoner. The pixel data contains the pixel location and the desired darkness of gray, i.e., amount of toner deposited. An imager uses the pixel data to generate the final halftoned image in a printer. A controller generates a feedback signal based on the printer's operation and the quality of the final halftoned image. The imager uses the feedback signal to modify the encoded gray pixel data in order to adjust the final halftoned image. The original coding of the image into gray pixel data is generic and does not depend on the characteristics of the printer being used. This invention reduces the computation of gray pixel data and allows the imager to be separate from the apparatus generating the gray pixel data.

Abstract: A method of processing image data to reproduce an image having good half-tone reproduction, sharpness, and details, through pulse modulation of a laser beam. In the method, the laser beam is turned on and off in accordance with the result of comparing an input image signal with a reference signal which has been frequency modulated in accordance with a shape feature of the input image signal. In the case of an image having low input contrast, the tone performance of an image output unit is improved by the mesh dots of the low spatial frequency. In the case of an image having high input contrast, an image having high sharpness and details is reproduced by the mesh dots of the high spatial frequency.

Abstract: Binary data (VDO) developed to a dot pattern are sequentially stored in line memories (1-9). A processing circuit (43) is constituted by a logic calculation circuit, and determines an edge portion of an image or a halftone image on the basis of 11.times.9 pixel data in shift registers (34-43). When the edge portion of an image is determined, data of a pixel of interest is converted to data that can print a smooth edge portion. Changed data (VDOM) is converted again according to the type of toner. The converted signal is supplied to a laser driver of a printer, and a printing operation is performed by scanning a laser. A resolution setting unit (1700) receives a resolution setting command from an external apparatus (1300), and sets a designated resolution in a printer (1200) according to the resolution setting command.

Abstract: Bit data of a received video signal is partially converted into a first signal representing a data sequence corresponding to the resolution of an LED head. The first signal is transmitted to the LED head in the form of a real printing data signal that is to be printed on a basic raster line in synchronism with a line timing signal. The remaining bit data of the received video signal, which are not converted into the first signal, are converted into a second signal representing another data sequence, and then stored in a line buffer. The second signal stored in the line buffer is transmitted to the LED head in the form of a real printing data signal that is to be printed on an additional raster line in synchronism with an additional line timing signal. The LED head drive energy with which the basic raster lines are printed and another LED head drive energy with which the additional raster lines are printed are set independently of each other.

Abstract: A full-color printer which reduces toner consumption by lowering the overall image density without changing the overall image tonality. An invalid data masking unit 31 masks non-printing area of a image signal 39 outputted from a FIFO buffer 30, and outputs the masked image data into a toner-saving image converter 32. The toner-saving image converter 32 zigzag masks the image signal every other pixel in main-scanning and subscanning directions based on a toner-saving mode designation signal A from a CPU 38. The masked image signal density is "00[H]". Thereafter, a .gamma. corrector 35 .gamma. corrects the masked image signal, and a PWM 36 performs pulse-width modulation on the .gamma.-corrected image signal. Image output is made by driving a semiconductor laser 120 with the pulse-width modulated signal.

Abstract: An electrostatic latent image developing method and an apparatus used in the latent image developing method are disclosed. In a first image developing method, a bias supply voltage provided to a developing dish is gradually increased during a developing process so as to prevent a decrease in an effective bias voltage applied to the developing dish caused by the attachment of the toner to the developing dish. Further, in a second developing method, the electrostatic latent image is formed on a photosensitive member by scanning a laser beam on a preliminarily charged photosensitive member in a lateral scanning direction, the thus formed latent image is developed by absorbing a toner in a liquid developer in a developing dish, wherein a cleaning pattern image having a large toner absorbability for absorbing the toner attached to a surface of the developing dish is provided on the photosensitive member by the laser beam before and/or after the latent image is formed on the photosensitive member.

Abstract: Resolution transforming raster based imaging system where an image is formed by displaying dots arranged along scan lines, scanned by an energization beam, the scan lines having a predetermined resolution and the system is driven by an image bit map having rows with resolution multiple of said predetermined resolution, a subset of the rows being related to the scan lines, bits in rows unrelated to scan lines, and representative of dots to the displayed being displayed as dots offset to a next adjacent scan line and with a size related to the surrounding bit pattern.

Abstract: Disclosed is a recording system in which an operation performed on the side of a printer unit in order to change over recording density is delayed while a recording operation is in progress. When a recording density changeover command is received during a recording operation, the density changeover is performed after the recording operation ends. A control unit which controls the printer unit is informed of the fact that the measures for changing over the recording density have been completed on the printer unit side.

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: An image forming apparatus for forming an image on an image forming body by scanning a plurality of modulated laser beams is disclosed. The apparatus is provided with a generator to generate a plurality of reference signals each with a differrent phase from other reference signals, a detector for detecting the difference of image density between two adjacent image pixels, combined modulator to generate a modulated laser beam by combining a selected laser beam, a selected reference signal and the image density. The detector classifies each pixel as one of an edge starting pixel, an edge ending pixel, and a non-edge pixel based on the value of image density difference relative to positive and negative threshold values. The selection of the laser beam and the reference signal is based on the image density difference detected by the detector and the class of the pixel.

Abstract: An image smoothing apparatus which forms dot images on a matrix array and smooths images of curvatures or diagonals included in the dot images. The apparatus includes a shifting unit which shifts a specific pixel to generate first smoothing video data, thereby selecting a divided video data for defining a time interval and timing of the specific pixel, and a masking unit which subjects divided video data to a Boolean conjunction operation with a mask pattern to generate second smoothing video data. Smoothed video data for the specific pixel is formed by selecting suitable operations from among the shifting and masking according to the arrangement of reference pixels adjoining to the specific pixel.

Abstract: An image forming apparatus comprises image information which outputs a sync signal and means generated image information synchronously with the sync signal; image forming means form an image on the basis of the image information at either one of a plurality of resolutions and which generates a sync request signal to request a transmission of the sync signal; and a resolution changeover means. When the image forming unit received the resolution change over request signal before the sync request signal is generated, the image forming unit executes the switching operation of the resolution, and if the image forming unit received the resolution changeover request signal after the sync request signal had been generated, the image forming unit does not execute the switching operation of the resolution.

Abstract: The present invention relates to an agent for magnetographic printers that includes a plurality (k) of elementary magnetic layers, having relatively hard hysteresis cycles with a threshold effect and marked saturation, of which the coercivity and/or thickness of the layers varies as a function of the position of the layer on a soft magnetic substrate.

Abstract: A printing system is provided for printing an image on a substrate. The image is represented by a set of words with each word including M bits and being modulated so as to produce a single bit stream. The printing system includes a multi-phase clock generator, responsive to a clock signal with a first clock rate, for producing N phase signals and a data serializer, communicating with the multi-phase clock generator, for receiving the N phase signals and the word set. In operation, the data serializer processes each word of the word set, with the N phase signals, to produce the single bit stream, the single bit stream being outputted at a second clock rate with the second clock rate being greater than the first clock rate. The data serializer communicates with a print engine, the print engine receiving the single bit stream for imaging the image on the substrate.

Abstract: A set of thinned halftone dot patterns useful in inkjet printing comprises a plurality of halftone cells corresponding to respective shade values. Each of the halftone cells includes a plurality of addressable points, with at least some of the points being turned "on" to define a halftone dot pattern, and at least some of the "on" points defining a core component of the halftone dot pattern being selectively turned "off", thereby producing a thinned halftone dot pattern. The thinned halftone dot patterns enable the use of higher addressability in an inkjet printing system to achieve a wider range of shade values while avoiding undesirable over-inking of printed halftone dot patterns due to excessive overlap between printed ink spots.

Abstract: A system for estimating pixel coverage in a digitized image including a controller for sampling pixels in a byte stream according to a varying spaced sampling mode so as to avoid image pattern errors. A processor for sums the sampled pixels, so that a total pixel on count in the digitized image may be estimated. A plurality of pixels may be included in bytes in the data stream; a look-up table, random number generator or other device may be used to select the addresses of the bytes to be sampled in the byte stream. The system may include an ink metering controller for providing ink to a printer or a printer service status indicator for providing various forms of printer consumable and component service data.

Abstract: An electrophotographic printer capable of maintaining printing quality and economizing toner without formation of white-out portion when toner consumption economizing mode is selected. Ordinary toner consumption mode and toner economizing mode are selectively used. If the toner economizing mode is selected, a shift resistor delays dot pulses from a pulse generating circuit and outputs the delayed shift pulses. An AND gate circuit produces a logical product of the dot pulses and the shift pulses. Thus, ON period of the output pulse can be shortened, thus economizing the toner consumption. Several toner economizing modes are provided so as to control length of ON period of the output pulses.

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

Abstract: An image processing apparatus connected with an image forming apparatus which forms an image at different degrees of resolution inputs image data from an external source and generates a control signal to control the degree of resolution at which the image forming apparatus forms the image from the image data. The control signal is a signal to control a driving power of the image forming apparatus. The image data input by the input means is output to the image forming apparatus, along with the control signal.

Abstract: An image forming device suitable for use in a laser beam printer includes an image forming unit for forming an image on a photoconductor, and a reproduction unit for reproducing a high density image and a halftone image on the photoconductor. A detector then detects the density of the high density image and the halftone image formed on the photoconductor. A controller controls an image forming condition of the image forming unit based on a detection result by the detector.

Abstract: The present invention relates to an electrophotographic technique for enhancing the quality of a reproduced image of character information and image information having an intermediate gradient.A latent image forming means provides a plurality of preset .gamma.-features and a plurality of sharpness features forsetting a resolving power of an image to be formed which can be selected optionally, and, in the latent image forming means, when a particular sharpness feature is set in response to a .gamma.-feature selected from the aforementioned .gamma.-features. In the reproduction of character image information, a .gamma.-feature for enabling the image reproduction to enhance the edge effect is selected, thereby emphasizing the sharpness feature. Whereas, in the reproduction of the image information to reproduce an intermediate gradient, a .gamma.-feature for enabling the reproduction of the intermediate gradient is selected, thereby weakening the sharpness feature.

Abstract: In a color image forming apparatus, a screen of each of electrostatic latent images to be formed by an exposing device has a parallel lines structure, and phases of the electrostatic latent images each having the parallel lines structure for at least two different colors are made different from each other. Accordingly, the color image forming apparatus can totally solve the problem caused by the rise in potential of exposed portions by toner charges and the dielectric property of toner layers and the problem caused by the toner shielding effect to thereby allow faithful reproduction of a highlight area important for a good halftone image, especially a high-quality color image.

Abstract: Partial images each constituting a predetermined matrix are sequentially taken out, and density data corresponding to pixels constituting the matrix are subjected to correction. The correction of the density data is so made as to respectively add density correcting values predetermined to correspond to pixel positions in the matrix to the density data. Consequently, the density data corresponding to the pixels constituting the matrix are considerably varied. Therefore, in a binary image obtained by subjecting the partial image constituting the matrix to halftone processing, the density of a document image is sufficiently reproduced.

Abstract: A method of, and an apparatus for, recording halftone dots on a photosensitive film by selecting halftone dots having different minimum repeating units in response to respective original image components. SPMs (103a to 103d) previously store screen pattern (SP) signals having different minimum repeating units, while address generation controllers (AGCp to AGCs) previously store address signals corresponding to the respective SP signals. Pattern selection signals (PPS) are inputted in response to respective original image components and the address signals are selected in correspondence thereto and inputted in the SPMs (103a to 103d), thereby reading the SP signals. Comparators (104a to 104d) compare pixel signals (DSa to DSd) expressing density levels of respective pixels forming a total image with the selected SP signals, to output halftone dot signals (DOTa to DOTd) in response to the result of this comparison.

Abstract: Apparatus and method for digitally printing a finely detailed image using pulse width modulation (PWM) with improved productivity over the prior art. Many images, or portions of images, generated by printers utilizing PWM do not require that any of the pixels be exposed for the maximum time possible, but that a maximum exposure can be determined for a selected portion of the image, whether it is for a line, for a paragraph, or for a selected color, that can then be used to speed up the printing of that portion of the image. Thus, a less than full density exposure can be set as the maximum, and the scanning speed increased accordingly to shorten the overall time required for printing that portion of the image.

Abstract: This invention relates an image forming apparatus capable of automatically adjusting image formation conditions. A transfer medium having a detecting pattern image formed by an apparatus main body is read by an original reading unit. A look-up table for setting latent image formation conditions is corrected on the basis of a read output, thereby correcting image densities in a main-scan direction and/or a sub-scan direction.

Abstract: An image forming apparatus for adjusting image density includes an input device for inputting a plurality of image type information and a discriminating device for discriminating the image type information in accordance with a signal other than a signal to be recorded. An image forming circuit, such as a printer, forms an image on the basis of image type information. A density adjusting circuit adjusts the image forming density of the image forming circuit in accordance with the input image type information. The discriminating device inputs a signal indicative of whether the input image type information indicates a text image or a graphics image, or whether it denotes Japanese or a European language (e.g., English). The discriminating device also inputs a signal indicative of the kind of font included in the input image type information or a signal indicative of a resolution for an output image to be formed by the printer.

Abstract: An image forming apparatus which can adjust a density comprises: a first input device to input image information; a second input device to input the kind of image information; an image forming circuit such as a printer form an image on the basis of image information which can vary an image forming density; and a density adjusting circuit to adjust the image forming density of the image forming circuit in accordance with the kind of input image information. The second input device inputs a signal indicative of whether the input image information indicates a text image or a graphics image or whether it denotes Japanese or European/English language. The second input device inputs a signal indicative of the kind of font included in the input image information or a signal indicative of a resolution of an output image which is formed by the printer.

Abstract: An image recording apparatus comprises an unequal interval quatization circuit for quantizing at an unequal interval an input multilevel image signal to prevent at least one signal having a tone level at which a recording density is unstable from being outputted, a circuit for calculating a difference between an unequal-interval-quantized signal and the input image signal, a buffer memory for temporarily storing the difference, a multiplexer for multiplying a recorded signal with a weight coefficient, an adder for adding a resultant signal from the multiplier to the input image signal, and a printer for recording an image, using the quantized signal as a record signal.

Abstract: In a laser printer having a serving semiconductor laser 14 as the printer engine part 3, the irradiation of a laser beam R, forming one pixel, is divided into a plurality of lighting times, and non-lighting times in response to clock horizontal synchronous signals CLKH1 and CLKH2, generated by a printer controller 2, so that the form of a light energy distribution, on a photosensitive body, for forming one pixel is made substantially trapezoidal. With this construction, the form of each dot of pixels composing an image is made substantially trapezoidal. This can lead to improving the image quality of any curve d portion and the sloped-line portion of the image, by reducing jaggedness.

Abstract: An improved method and apparatus for characterizing a full color gamut of a digital photosensitive color proofing system having at least two separately controllable process parameters uses a one page color standard for calibrating the full color gamut. The one page color standard includes a plurality of color density test areas on the page, with each color density test area having a test patch for each colorant printed at a selected color density that is within a range of color densities, and a plurality of tone rendition test areas on the same page. There is one tone rendition area for each of the color density test areas, and each tone rendition test area has a plurality of test tints for each colorant as a primary color and a plurality of test patches for a set of secondary colors composed from combinations of the primary colors.