Xerox Corporation

Virgil Joseph Hull

Peter A Torpey

Glenn K Smith

Joseph F Stephany

Lesley P Dudek

Alain E Perregaux

Andras I Lakatos

Joseph J Wysocki

John H Steele

Lowell W Knapp

Christopher R Curtis

Sui K Hark

James S Celebi

Richard B Dingwall

Ram S Narang

Eugene C Faucz

The present invention is directed to a method for differentially processing image types within a document image to enhance the quality of on an image on a receiving medium. In one aspect of the invention, the method begins by receiving document image data including one or more image regions. The method determines for each image region whether the region includes any image data corresponding to a first image type. The method then prints regions including image data corresponding to the first image type according to a first pixel management process and prints regions not including image data corresponding to the first image type according to a second pixel management process.

Adaptive pixel management using object type identification

The present invention is directed to a method for processing color image data to reduce intercolor bleeding in an image printed on a receiving medium. The method begins with the receipt of a target pixel that includes a plurality of separation pixels corresponding to individual color planes, the color planes including a black plane and at least one non-black plane. The steps of the method further include determining if the target pixel is within an black border region near a black/color interface, and if so, modifying the target pixel using a substitution operation according to a black pixel modification pattern, the black pixel modification pattern identifying separation pixels in the black plane to replace with separation pixels from a non-black plane; and determining if the target pixel is within a color border region near a black/color interface, and if so, modifying the target pixel using a thinning operation according to a color pixel modification pattern, the color pixel modification pattern identifying a pattern of separation pixels in a non-black plane to remove from the composite image.

Reduction of intercolor or bleeding in liquid ink printing

The present invention is a method for processing color image data to determine if a target pixel is within a border region near an interface. The method begins with the identification of a target pixel within the color image data and then determines if the target pixel is a black or a color pixel. If the target pixel is a black pixel, the method collects a first set of pixel statistics from a first window comprising the target pixel and pixels surrounding the target pixel and analyzes the first set of statistics to determine if the target pixel is within an N-pixel wide black border region near an interface. If the target pixel is a color pixel, the method collects a second set of pixel statistics from a second window comprising the target pixel and pixels surrounding the target pixel and analyzes the second set of statistics to determine if the target pixel is within an M-pixel wide color border region near an interface.

Identification of interfaces between black and color regions

An apparatus and method for forming an image with fluids having different firing velocities from a bi-directional print head results in a reduction in bi-directional misalignment error. The bi-directional misalignment error is reduced by delaying the firing of a drop of the higher velocity fluid on the return swath of the print head.

Method and apparatus for improved bi-directional error for multicolor printers

The present invention provides a method of processing color image data for printing on an inkjet printer to maintain edge quality in an image recorded on a receiving medium. The method begins with the receipt of color image data comprising a plurality of color planes that combine to form an array of composite pixels, the color planes including at least one black plane and at least one non-black plane, wherein each color plane comprises an array of separation pixels, each separation pixel having at least two states, a first state corresponding to depositing no ink at an image location and a second state corresponding to depositing ink at an image location. The method then identifies an interface between an black area and a non-printed area; defines an N-pixel wide border within the black area; and modifies the color image data corresponding to the N-pixel wide border to reduce the number of second state separation pixels in a non-black plane.

Maintaining black edge quality in liquid ink printing

The present invention provides a method for processing color image data for printing on an inkjet printer to reduce intercolor bleeding in an image recorded on a receiving medium. The method receives a target pixel comprising multiple separation pixels, wherein each separation is associated with a separate color plane and has at least three states, a first state corresponding to depositing no ink drops, a second state corresponding to depositing one ink drop, and a third state corresponding to depositing more than one ink drop. The method further includes determining if the target pixel is within a black border region near a black/color interface or within a color border region near a black/color interface. If the target pixel is within a black border region, the method replaces the target pixel with a black border output pixel derived from a black pixel modification pattern identifying an arrangement of separation pixels to deposit approximately one drop for each pixel location in the black pixel modification pattern. Similarly, if the target pixel is within a color border region near a black/color interface, the method replaces the target pixel with a color border pixel derived from a color pixel modification pattern identifying an arrangement of separation pixels for each non-black color plane that deposits approximately one drop for each pixel location.

Reduction of intercolor bleeding in liquid ink printing

The present invention provides a method for processing color image data to maintain edge quality in an image recorded on a receiving medium. The method includes receiving a target pixel comprising multiple separation pixels, each separation being associated with a separate color plane and having at least three states, a first state corresponding to depositing no ink, a second state corresponding to depositing one ink drop, and a third state corresponding to depositing more than one ink drop; determining if the target pixel is within a black border region near a black/non-printed interface; and if so, setting the separation pixel associated with a black color plane to a selected black pixel state.

A liquid crystal display unit is provided which includes a primary, image-defining display and a secondary display, arranged in series with the primary display. The primary and secondary displays have equal numbers of light shutters, similarly sized and located on each display, so that when the corresponding light shutters on the primary and secondary displays are closed, substantially no light passes through the viewing side of the primary display. An opaque mask is formed on the input side of the primary display to define the shape of the image elements to be displayed. This mask covers the edges of the primary display light shutters to define the image elements display. This mask permits the primary and secondary displays to be easily aligned with each other. Color patches can be located on the light input side of the primary display light shutters so that the viewed images are in color. The use of the opaque mask to form the image elements eliminates the need to form precisely shaped color patches. Since and the mask blocks all light between light shutters, a display is provided having a true dead front. The true dead front display permits colored text displays using mimic-type electrodes to be produced. Since the secondary displays need not perform as well as the primary displays, displays which are not suitable for use as primary displays can be used as the secondary displays.

Color liquid crystal display with dead front appearance having opaque

A liquid crystal display unit is provided which includes a primary, image-defining display and a secondary display, arranged in series with the primary display. The primary and secondary displays have equal numbers of light shutters, similarly sized and located on each display, so that when the primary and secondary displays are placed in series their respective light shutters are also in series. When corresponding light shutters on the primary and secondary displays are closed, substantially no light passes through the displays to the opposite side of the primary display. An opaque mask is formed on the input side of the primary display to define the shape of the image elements to be displayed. This mask covers the edges of the primary display light shutters to define the image elements such that each light shutter on the secondary display is larger in size than its corresponding image element on the primary display. This permits the primary and secondary displays to be easily aligned with each other. Color patches can be located on the light input side of the primary display light shutters so that the viewed images are in color. The use of the opaque mask to form the image elements eliminates the need to form precisely shaped color patches. Since no light leaks through the light shutter pairs when switched off, and the mask blocks all light between light shutters, a display is provided having a true dead front. The true dead front display permits colored text displays using mimic-type electrodes to be produced. Since the secondary displays need not perform as well as the primary displays, displays which are not suitable for use as primary displays can be used as the secondary displays.

Method of making color liquid crystal display with dead front appearance

Liquid crystal devices are provided with a DC current blocking layer which improves the lifetime of the liquid crystal device and also permits the use of two-level drivers, thus reducing the complexity of the driving scheme necessary to address the liquid crystal devices. Preferably, the blocking layer is the alignment layer which is made from poly-para-xylylene having a thickness sufficient to act as a DC blocking layer. Additionally, specific driving schemes for driving liquid crystal devices are provided. When the liquid crystal device includes a material which relaxes when no voltage is applied thereto (e.g., a nematic material), the information signal is entirely removed from alternating time frames during which the liquid crystal device is addressed. When the liquid crystal device includes a ferroelectric material, an arbitrarily large voltage potential is applied to the electrodes located on one side of the ferroelectric material for a first portion of a dwell time so that the pixels of the liquid crystal device are easily cleared of any previous information.

Control of liquid crystal devices

A light shutter is provided wherein a first plate which includes a pixel electrode for use in applying a includes a background electrode located adjacent the pixel voltage potential across a ferroelectric material also electrode and substantially surrounding the pixel electrode, whereby an electronic mask can be created adjacent the pixel electrode in the ferroelectric material. A second plate which, along with the first plate sandwiches the ferroelectric material, includes a backplane electrode which is used in conjunction with the pixel and background electrodes on the first plate for applying voltage potentials across the ferroelectric material. By maintaining a minimal amount of spacing between the background electrode and the pixel electrode, a voltage potential can be applied between the background and backplane electrodes so that the ferroelectric material located adjacent the pixel electrode can be maintained in, for example, a non-light transmissive state whereby the contrast between the pixel and inter-pixel regions is greatly improved. Image bars or displays can be formed by arranging a plurality of light shutters (and consequently, pixel electrodes) on the first plate with one or more background electrodes surrounding the plurality of pixel electrodes. Additionally, the background electrode and/or other electrodes can be used for applying electric fields to the ferroelectric material which are non-parallel to the polarization direction of the molecules of the ferroelectic material to reduce the time required to change the ferroelectric material between light transmissive and light blocking states.

Ferrolectric liquid crystal devices having improved operating properties

A linear array of liquid crystal shutters mounted near a photoreceptor surface and arranged transversely to the direction of travel of the photoreceptor surface, an array of multiplexed thin film transistors (TFT's) connected to the array of liquid crystal shutters for electrically driving the shutters and logic means connected to the multiplexed array of thin film resistors selectively pulsing the liquid crystal shutters to selectively expose the photoreceptor surface a line at a time. The system further includes a single backplane and circuit means for producing an electric field between the backplane and electrodes of each of the liquid crystal shutters to prevent passage of light through the shutters and means for selectively de-energizing each of the pairs of electrodes for predetermined time period in response to the receipt of input data signals.

Liquid crystal print bar having a single backplane electrode

A linear array of liquid crystal shutters mounted near a photoreceptor surface and arranged transversely to the direction of travel of the photoreceptor surface, an array of thin film transistors connected to the array of liquid crystal shutters for electrically driving the shutters and logic means connected to the array of thin film transistors selectively pulsing the liquid crystal shutters to selectively expose the photoreceptor surface a line at a time. The system further includes circuit means for producing an electric field between the opposed electrodes of each of the liquid crystal shutters to prevent passage of light through the shutters and means for selectively de-energizing each of the pairs of electrodes for predetermined time period in response to the receipt of input data signals.

Liquid crystal print bar

The invention is a liquid crystal material between horizontal and vertical electrodes. A xerographic drum is placed underneath the electrodes/liquid crystal configuration and an optical system provides light or no light at the intersection of the electrodes to be focused on the xerographic drum. A single line of data is created by printing first the odd elements of the data and then the even elements. First, data is clocked into a shift register coincident with clock pulses. This is the data for the next line to be printed or displayed and not the presently printed or displayed line of odd bits. When the new line has been completely shifted in, a latch pulse transfers the data to latches, a one line parallel in parallel out buffer. Then, on the even half of the cycle, the even bits of data which have been shifted in while the odd dots are being printed, are latched to the drivers.

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Fairport, NY, United States of America

Virgil Joseph Hull