The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 21, 1980
Filed:
Jun. 08, 1978
Warren Childers, Houston, TX (US);
Graphic Arts Manufacturing Company, Houston, TX (US);
Abstract
In a preferred embodiment of the present invention, an optical densitometer is provided having an improved output scale resolution. An output scale reading from 0.000 to 4.000, having a resolution to 0.001, is obtained by improved method and apparatus for obtaining the reference operating characteristics for 'zero-mode' parameters. An analog reference anode signal is formed by making adjustments in a generally antilogrithmic relationship to the difference between the reference anode signal being generated and the anode signal produced under the zero-mode conditions. The antilogrithmic relationship improves scale resolution near the zero point and increases densitometer stability during a subsequent measurement cycle. The combination analog reference anode signal generating circuit and an improved exponential characteristic selection circuit enables the improved output resolution and accuracy to be obtained. The exponential characteristic selection circuit enables the measurement circuitry to be adjusted in accordance with the actual photomultiplier tube in the circuit to produce and maintain a measurement having an improved accuracy.