Tektronix, Inc.

Other

Paul A McManus

Gerald M Murch

Robert J Beaton

Joann M Taylor

Novia A Weiman

Roxanna F Rochat

Donald R Titterington

Joern B Eriksen

Michael D Jones

Gregory L Hoffman

David L Mead

A video monitor color control system including means for calibrating the intensity response of CRT phosphor sets to each of a plurality of electron gun control levels. Provided is a processor (24) that generates a sequence of discrete DAC signals, each DAC signal identifying an electron gun and a DAC value for driving the electron gun at a selected control level. Also provided is a monitor driver (22) connected to the processor (24) and to the monitor (20) and controllable in response to a DAC signal for driving the electron gun identified by the DAC signal at the control level identified by the DAC signal. The driven electron gun excites the associated phosphor set. A sensor (28) is provided for detecting the luminous intensity level of the phosphor excited by the electron gun, and for converting the detected intensity into a representative signal. The processor (24) receives for each discrete DAC signal the representative signals produced by the sensor and generates a look-up table for each gun defining intensity levels for each of the plurality of electron gun control levels.

Video monitor color control system

A method and apparatus for reversibly transforming color, which is selected from a gamut of colors producible by the primaries of a color display device (20), into a perceptually uniform color space. The coordinates of the color space are readily convertible into internationally accepted standards for color measurement. Also provided, is a method for transforming the color space coordinates of a selected color into the corresponding relative primary intensity levels of the display device (20).

Display-based color system

The colorimetric parameters of a color sample (42) that is illuminated by a reference light are processed for reproduction by a video monitor (20) or the like. A color filter assembly (40) and associated sensor (28) are used to generate signals indicative of the colorimetric parameters of the illuminated color sample (42). A computer (24) transforms the signals into a form suitable for driving a video monitor (20) to reproduce the color sample (42) on the monitor screen.

Method and apparatus for processing colorimetric parameters of a color

A color image copying system (10) includes a light modulator (12) that receives incident light rays emanating from a source (14) of light. The light modulator comprises a light dispersing apparatus (54) that disperses different wavelengths of the incident light rays to different locations on a focal surface (60). A filter mask (68) aligned with the focal surface transmits preselected wavelengths of the ultraviolet light and blocks light of all other wavelengths. Each of a set of light valves (86, 88, 90) receives a different wavelength of light transmitted by the filter mask and intensity modulates it in accordance with image pixel information provided by an information source (16). An optical focusing apparatus (56) focuses the intensity-modulated wavelengths of light to a relatively small location (20) on an image focal surface (22) which is aligned with a light-sensitive medium (24). The light focused at the location exposes the light-sensitive medium to each of the wavelengths of light for a particular period of time determined by the image pixel information. The location to which the intensity-modulated light is focused is sequentially aligned with adjacent regions of the light-sensitive medium in synchronism with the delivery of image pixel information corresponding to the adjacent regions. This process continues in pixel-by-pixel fashion across the surface of the light-sensitive medium to form a color image copy in a single exposure pass over such surface.

Color image copying system

A method for matching hardcopy colors to display colors for registered-dot ink-jet copiers. Video RGB (red-green-blue) is converted into chromaticity coordinates in XYZ color space. An explicit solution is achieved by defining a new MSW color space which restricts the hardcopy colors to some percentage of one of the binary mixtures (M) of inks, some percentage of one of the single (S) inks, and some percentage of paper white (W). The color data in XYZ space is converted to MSW space and unreachable display colors are mapped into reachable hardcopy colors. Correction for hardcopy non-linearities is accomplished by using coverage ratios to correct for color shifts due to interaction among the inks. The MSW values are then converted to CMY (cyan-magenta-yellow) values which are processed in accordance with an appropriate dithering algorithm for conversion into dots for printing on paper.

Growing community of inventors

Sherwood, OR, United States of America

Paul A McManus