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US 6,208,069 B1Granted
Low-pressure mercury discharge lamp for tanning
AssigneeU.S. Philips Corporation
InventorsThomas Jüstel, Hans Nikol, Cornelis R. Ronda, Dick Van Der Voort, Cornelis J. Jalink
Life of this patent
Estimating the term…
Abstract
A lamp vessel is made from a material which absorbs short-wave UV radiation. In addition, the luminescent screen comprises cerium-activated lunthanum phosphate and a luminescent substance having an emission band whose maximum is situated in the wavelength range from 340 nm and whose half-value ranges between 35 nm and 80 nm. The emission spectrum of the lamp for wavelengths below 400 nm corresponds closely to the solar spectrum while the lamp also has a high erythema L light output.
Claims11
A low-pressure mercury discharge lamp for tanning purposes, comprising:
- a lamp vessel which is closed in a gastight manner and filled with mercury and one or more inert gases, wherein the lamp vessel is made of a short-wave UV radiation-absorbing material whose transmission for UV radiation with a wavelength of 312.6 nm ranges between 10% and 50% and whose wavelength range over which the transmission of the UV radiation changes from 20% to 80% is smaller than 40 nm and greater than 28 nm,
- a luminescent screen comprising a first luminescent material having an emission band with an emission maximum between 300 nm and 330 nm and a half-value width of this emission ranging between 15 and 30 nm,
- the luminescent screen further comprising a second luminescent material whose reflection for UV radiation of a wavelength above 300 nm is more than 80%, and said second luminescent material having an emission band with an emission maximum in the wavelength range from 340 nm to 370 nm, the half-value width of which ranges between 35 nm and 80 nm, and
- means for maintaining a discharge in the lamp vessel during operation of the lamp, wherein the lamp has an emission spectrum between 290 nm and 330 nm with a maximum value at said wavelength of 312.6 nm.
1 more element
A low-pressure mercury discharge lamp for tanning purposes, comprising
- a lamp vessel which is closed in a gastight manner and filled with mercury and one or more inert gases, wherein the lamp vessel is made of a short-wave UV radiation-absorbing material whose transmission for UV radiation with a wavelength of 312.6 nm ranges between 10% and 50% and whose wavelength range over which the transmission of the UV radiation changes from 20% to 80% is smaller than 40 nm and greater than 28 nm,
- a luminescent screen comprising a first luminescent material having an emission band with an emission maximum between 300 nm and 330 nm and a half-value width of this emission ranging between 15 and 30 nm,
- the luminescent screen further comprising a second luminescent material whose reflection for UV radiation of a wavelength above 300 nm is more than 80%, and said second luminescent material having an emission band with an emission maximum in the wavelength range from 340 nm to 370 nm, the half-value width of which ranges between 35 nm and 80 nm, and
- means for maintaining a discharge in the lamp vessel during operation of the lamp, wherein the second luminescent material includes lead-activated strontium magnesium silicate.
1 more element
A low-pressure mercury discharge lamp for tanning purposes, comprising
- a lamp vessel which is closed in a gastight manner and filled with mercury and one or more inert gases, wherein the lamp vessel is made of a short-wave UV radiation-absorbing material whose transmission for UV radiation with a wavelength of 312.6 nm ranges between 10% and 50% and whose wavelength range over which the transmission of the UV radiation changes from 20% to 80% is smaller than 40 nm and greater than 28 nm,
- a luminescent screen comprising a first luminescent material having an emission band with an emission maximum between 300 nm and 330 nm and a half-value width of this emission ranging between 15 and 30 nm,
- the luminescent screen further comprising a second luminescent material whose reflection for UV radiation of a wavelength above 300 nm is more than 80%, and said second luminescent material having an emission band with an emission maximum in the wavelength range from 340 nm to 370 nm, the half-value width of which ranges between 35 nm and 80 nm, and
- means for maintaining a discharge in the lamp vessel during operation of the lamp, wherein the luminescent screen further comprises a third luminescent material whose reflection for UV radiation having a wavelength above 300 nm exceeds 80%, said third luminescent material having an emission band with an emission maximum between 370 nm and 400 nm and a half-value width in the range between 35 nm and 80 nm.
1 more element
Dependencies are inferred from the claim text.