Browse Prior Art Database

Matching Flash Tubes to Reflectors by Spectral Re-Pumping

IP.com Disclosure Number: IPCOM000034159D
Original Publication Date: 1989-Jan-01
Included in the Prior Art Database: 2005-Jan-26
Document File: 3 page(s) / 83K

Publishing Venue

IBM

Related People

Baumann, GW: AUTHOR

Abstract

Disclosed is a means of improving the efficiency of a flash system comprised of a flash tube and reflector. Fig. 1 shows such a system. The output of this system is affected by the match of the spectral reflectivity of the reflector with the output spectrum of the flash tube. If the output bands of the flash tube match the absorptivity bands of the reflector, the output will be low. Conversely, if the flash tube output is concentrated to those wavelength bands where the reflector efficiency is high, the output will be high. This invention achieves that matching. The output spectrum of a typical flash tube is a rather "choppy" replica of Planck's black body spectrum. Fig. 2 shows a typical spectrum.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 63% of the total text.

Page 1 of 3

Matching Flash Tubes to Reflectors by Spectral Re-Pumping

Disclosed is a means of improving the efficiency of a flash system comprised of a flash tube and reflector. Fig. 1 shows such a system. The output of this system is affected by the match of the spectral reflectivity of the reflector with the output spectrum of the flash tube. If the output bands of the flash tube match the absorptivity bands of the reflector, the output will be low. Conversely, if the flash tube output is concentrated to those wavelength bands where the reflector efficiency is high, the output will be high. This invention achieves that matching. The output spectrum of a typical flash tube is a rather "choppy" replica of Planck's black body spectrum. Fig. 2 shows a typical spectrum. The only reflector material with high reflectivity throughout the spectrum is metallic silver with a protective semi- conductor overcoat. Such reflectors are extremely expensive. Economical reflectors are made from aluminum sheet material with enhancing

(Image Omitted)

overcoats. However, these reflectors have significant bands of low reflectivity in the flash spectrum, as shown in Fig. 3. Much of the energy radiated out of the flash tubes in these bands is absorbed in the reflector. The purpose of this invention is to shift the emission out of these absorptive bands into the reflective ones. To achieve this shift, selectively reflective coatings are deposited on the flash tube. Fig. 4 shows the desired characte...