Abstract

The color difference meter has three photodetectors, each with a separate tristimulus filter, and each receiving some of the light reflected from the specimen. Signals from the photodetectors are measured by analog circuits that give rectangular coordinates for surface colors in close correspondence to their positions in uniform color space. The first model described in 1948 uses barrier-layer photocells and three tristimulus filters. Recently, a model employing vacuum phototubes and four filters has been built. Use of vacuum phototubes makes it possible to substitute a dc amplifier and pivot meter for the suspension galvanometer necessary with barrier-layer photocells. By thermostatting the phototube chamber, excellent stability is obtained. A light pipe in the viewing beam provides a more stable and efficient mixer of light to the different photodetectors than the white-lined sphere used previously.

© 1958 Optical Society of America

Full Article  |  PDF Article
OSA Recommended Articles
Description and Measurement of White Surfaces

Richard S. Hunter
J. Opt. Soc. Am. 48(9) 597-605 (1958)

A Multipurpose Photoelectric Reflectometer

Richard S. Hunter
J. Opt. Soc. Am. 30(11) 536-559 (1940)

A Photoelectric Color Temperature Meter for Incandescent Lamps

M. H. Sweet
J. Opt. Soc. Am. 30(11) 568-571 (1940)

References

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Figures (17)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Tables (1)

You do not have subscription access to this journal. Article tables are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Equations (6)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription