Daylight lamp
AssigneeTailored Lighting Inc.
InventorKevin P. McGuire
Life of this patent
Estimating the term…
Abstract
A lamp for producing a spectral light distribution which is substantially identical in uniformity to the spectral light distribution of a desired daylight throughout the entire visible light spectrum from about 380 to about 780 nanometers. The lamp contains a lamp envelope comprised of an exterior surface, a light-producing element substantially centrally disposed within said lamp envelope, and a coating on said exterior surface of said lamp envelope.
Claims19
A lamp for producing a spectral light distribution substantially identical in uniformity to the spectral light distribution of a desired daylight with a color temperature of from about 3500 to about 10,000 degrees Kelvin throughout the entire visible light spectrum from about 380 to about 780 nanometers, comprising:
- (a) an enclosed lamp envelope having an interior surface and an exterior surface;
- (b) a light-producing element substantially centrally disposed within said lamp envelope and which, when excited by electrical energy, emits radiant energy throughout the entire visible spectrum with wavelengths from about 200 to about 2,000 nanometers at non-uniform levels of radiant energy across the visible spectrum;
- and
- (c) at least one coating on at least one of said surfaces and having a transmittance level in substantial accordance with the formula
- T(l)=[D(l)-[S*(l).times.(1-N)]]/[S(l).times.N],
- wherein T(l) is the transmission of said envelope coating for said wavelength l from about 380 to about 780 nanometers, D(l) is the radiance of said wavelength for the desired daylight, S(l) is the radiance of said element at said wavelength at normal incidence to said lamp envelope, S*(l) is the radiance of said element at said wavelength at non-normal incidence to said lamp envelope, and N is the percentage of visible spectrum radiant energy directed normally towards said exterior surface of said lamp envelope.
A lamp for producing a spectral light distribution which is substantially identical in uniformity to the spectral light distribution of a desired daylight with a color temperature of from about 3500 to about 10,000 degrees Kelvin throughout the entire visible light spectrum from about 380 to about 780 nanometers, wherein said lamp is comprised of a lamp envelope comprised of an exterior surface, a filament substantially centrally disposed within said lamp envelope, and a coating on said exterior surface of said lamp envelope, and wherein:
- (a) said filament, when excited by electrical energy, emits radiant energy at least throughout the entire visible spectrum with wavelengths from about 200 to about 2,000 nanometers at non-uniform levels of radiant energy across the visible spectrum, wherein:
- 1. in excess of thirty percent of said radiant energy emitted by said filament is produced at wavelengths in excess of 700 nanometers,
- 2. said filament has a color temperature of at least about 2,800 degrees Kelvin,
- 3. said filament is disposed at a distance of less than 8 centimeters from said lamp envelope,
- (b) at least one of the envelope and the coating on said exterior surface of said lamp envelope prevents the transmission of at least about 50 percent of the ultraviolet radiation with a wavelength of from about 200 to about 380 nanometers emitted by said filament;
- (c) said coating on said exterior surface of said lamp envelope reflects at least about 50 percent of the infrared radiation with a wavelength of from about 780 to about 2,000 nanometers emitted by said filament;
- (d) said coating on said exterior surface of said lamp envelope has a transmittance level for wavelengths from about 380 to about 780 nanometers in substantial accordance with the formula
- T(l)=[D(l)-[S*(l).times.(1-N)]]/[S(l).times.N],
- wherein T(l) is the transmission of said envelope coating for said wavelength l from about 380 to about 780 nanometers, D(l) is the radiance of said wavelength for the desired daylight, S(l) is the radiance of said element at said wavelength at normal incidence to said lamp envelope, S*(l) is the radiance of said element at said wavelength at non-normal incidence to said lamp envelope, and N is the percentage of visible spectrum radiant energy directed normally towards said exterior surface of said lamp envelope;
- and
- (e) said exterior surface of said lamp envelope reflects back to said filament at least thirty percent of all the radiation emitted by said filament.
A reflector lamp combination for producing a spectral composition comprising:
- (a) a bulb including a filament which, when excited by electrical energy, emits radiant energy at least within and throughout the visible spectrum with wavelengths (l) from about 380 to about 780 nanometers, but with the levels of radiant energy at each wavelength across the spectrum not being uniform in intensity;
- (b) a light transmitting reflector body with a surface to intercept such visible spectrum radiant energy, wherein said filament is positioned within said reflector so that at least about 60 percent of said visible spectrum radiant energy is directed towards said reflector surface;
- (c) filter coating means on the surface of said reflector body, for reflecting in a desired direction radiance from among the entire said visible spectrum radiant energy directed towards said reflector surface, which when combined with the radiance of the visible spectrum radiant energy emitted by the filament and not directed towards said reflector surface produces a total usable visible light or relatively uniform radiance throughout the visible spectrum which is substantially identical to daylight color temperature and contains relatively uniform levels of radiant energy throughout the visible light spectrum from about 380 to about 780 nanometers, the balance of the radiant energy directed towards said reflector surface not reflected by the coating means being transmitted by said reflector body in directions other than the desired direction;
- (d) second reflector means positioned adjacent to said reflector body for reflecting the light transmitted by the reflector body toward the desired direction;
- (e) means for moving the second reflector means parallel to the desired direction for varying the color temperature of the visible light as viewed from the desired direction;
- and
- (f) a diffuser.
Dependencies are inferred from the claim text.