Heat Filter

heat filter

[′hēt ‚fil·tər]
(optics)
Special glass in condenser lens systems to keep heat from film.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Heat Filter

 

an attachment to or a component of an optical system that is designed to eliminate infrared (heat) rays from the luminous flux passing through the system. The heat rays may be absorbed, as in absorbing heat filters, or removed from the luminous flux, as in cold light interference mirrors.

The simplest heat filter is a glass plate transmitting rays of visible light and absorbing heat rays. Heat filters are used in the light sources of biological microscopes and photomicrographic devices to protect live microorganisms from the harmful effects of heat, as well as in various projection instruments to prevent overheating of the original, whose image is being projected onto a screen.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

heat filter

An optical filter placed in a light path to reduce heating effect of a light source; transmits the visible spectrum of the light radiated by the source, but rejects the near-infrared radiation.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.
References in periodicals archive ?
And with the sealed lighthead and Thermosorb[R] heat filter, the D-Series Plus is extremely cool.