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:
Nov. 22, 1977
Filed:
Apr. 02, 1976
Gerald L Klein, Orange, CA (US);
Beckman Instruments, Inc., Fullerton, CA (US);
Abstract
A standard for calibrating a densitometer or the like is disclosed consisting of an optically transparent substrate supporting a plurality of spaced bands of different predetermined optical densities. Each band comprises alternate dark and clear strips and is sized to eclipse a beam of light generated in the densitometer and defining an illuminated zone. The width of the clear strips is large compared to the wavelength of the light beam and small compared to the width of the illuminated zone so that the quantities of light passing through the bands as the standard moves through the densitometer, and hence the optical densities of the bands, are directly proportional to the ratio of the areas of the clear strips to the areas of the dark strips in the bands. The bands are placed at an angle to the scan axis of the illuminated zone to present a gradient change in optical density to a scanning densitometer which is within the response time thereof. Additionally, the strips in each band are at an angle to the scan axis to pass across the illuminated zone with an apparent sweeping motion to average out any optical or illumination irregularities across the zone.