Lucid Technologies, Inc.

Cv Us, Inc.

Robert J Hutchison

Jay M Eastman

James M Zavislan

William J Fox

Roger J Greenwald

Cormic K Merle

John A Boles

John A Teleska

Terry Satterthwaite

Cormic K Merkle

A colorimeter capable of calibrating color monitors, whether having cathode ray tube or liquid crystal (LCD) displays, is provided by a photometric array of photodetector and optical filter pairs. The filters include long-pass, edge filters which cover overlapping regions at the upper end of the visible spectrum and a filter which covers the entire visible spectrum. The outputs of the photodetectors are digitally synthesized to provide a response which mimics the response established by the Commission Internationale de l'Eclairage (CIE) xyz (bar) functions almost perfectly. The response which is mimicked may be represented by the CIE color matching functions. The pairs and the associated components are mounted on a printed circuit board captured in a clamshell housing and having an array of apertures which define angularly constrained fields of view of a surface from which the light, to be colormetrically analyzed, emanates. The colorimeter is capable generally of measuring the color characteristics, especially the color temperatures of radiation radiating and reflecting bodies (sources), including so-called black bodies.

Colorimeter

A mounting for a colorimeter enables it to make measurements of light emanating from a color monitor screen without affecting the colors produced by the screen or allowing the entry of ambient light which can affect measurements by the calorimeter. Pressure applied against a screen, especially of an LCD color monitor, can cause changes in the color of the light emanating from the screen. The mounting apparatus conforms to the screen, and seals the screen against ambient light entering into the calorimeter, while limiting the pressure against the screen. The apparatus is provided by a plate of compliant material, having an opening to which the calorimeter is attached. The surface of the plate, is disposed against the screen of the monitor. Since the pad is compliant, it seals the colorimeter from entry thereinto of ambient light. A strap can be expanded, and holds the pad on the monitor and against the screen. The strap is attached to the plate, and is placed around the back of the monitor.

Apparatus for mounting an electro optical measuring device, especially a

A spectrophotometer which is highly manufacturable at minimum cost nevertheless provides precision of measurement of spectra components of light which is projected therein by maintaining precise optical alignment of optical and electrical components thereof. These components are mounted in a module which is contained in a housing having an entrance aperture which defines an object area for light the spectrum of which is measured by a photodetector in the module at an image area. The module has a base plate provided by a printed circuit board on which a closed wall encompasses an area (a corral) on one side of the circuit board. The wall is a one piece structure which extends to the vicinity of the edge of the board. It is assembled with the board as a unitary structure so that the assembly is made torsionally rigid and resists bending in the plane of the board. The module may be of sufficiently small size so as to be located in a housing which is hand held, thereby providing a hand-held spectrophotometer.

Electro-optic module especially suitable for use in a spectrophotometer

Spectrophotometer and electro-optic module especially suitable for use

In order to digitize with sufficient resolution an analog signal, which may be generated by a photodetector in a spectrophotometer, an improved analog to digital conversion system is provided having an integrator stage, an analog to digital converter, a microprocessor and interface circuits for providing communication between the microprocessor and a host computer. The integrator may include an operational amplifier with a capacitor in feedback relationship therewith for providing an output which varies linearly as function of time. The microprocessor operates the analog to digital converter to sample the integrator output at successive increments of time which increase in accordance with a binary relationship to an increment corresponding in binary value to the desired upper end of the resolution range. The digitized samples from the analog to digital converter are compared with a predetermined value in the upper end of the amplitude range of the converter. Low amplitude analog signals do not reach the predetermined level until the later sampling times and thus are resolved at the upper end of the resolution range. Higher amplitude analog signals are resolved at the lower end of the resolution range. Thus the resolution dynamically and automatically increases inversely with the amplitude of the analog signal being digitized. The digitized value is expressed by two binary numbers, one corresponding to the number of samples until detection of the sample of the integrator output achieving the predetermined amplitude, and the other corresponding to the value which the integrated signal has achieved.

Analog to digital conversion system having automatically and dynamically

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Pittsford, NY, United States of America

Robert J Hutchison