 Wysłany: Wto 3:43, 26 Kwi 2011 Temat postu: lumens / lm |
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| LED products. In addition,business signs, there are some simple online color coordinates and correlated color temperature of the table and the small software, readers can send e-mail free of charge to me.
Question three: blue LED and white LED luminous flux why the big difference? A: This is a very critical issue basis, often to some engineers doubt. Industry Forum in China Optics and Optoelectronics, Optoelectronics Association Forum on Overseas Chinese University are related to the industry on this issue. Is the source of doubt: were prepared by blue and white LED LED. support, chip,LED outdoor sign, epoxy resin and other materials and processes are the same (only difference between the increase in white LED technology point of fluorescent plastic), then out of the blue LED preparation flux are smaller than the white LED. The white LED luminous flux higher than the blue LED is due to what? First of all, to understand three basic concepts. Radiation flux (symbols: ξ, unit: W / W), said beam of light through the radiated power per unit area. For a given frequency of light near the relative radiation flux distribution function can be used e (λ) to describe. For the light of a wavelength λ, and its radiation flux can be expressed as: ξ = e (λ) dλ. See the function as (symbol: ν (λ)),LED writing board, characterized by the subjective feeling of the human eye to light. Radiation flux sufficient to describe the brightness of light, because the same flux of light, due to different frequencies, the human eye's visual feel intensity is different. Yellow green eyes on the most sensitive to the infrared and ultraviolet are not caused by vision. In order to characterize the objective of the radiation flux and the human relationship between the subjective feelings, introduced as the see function ν (λ) concept. If a wavelength λ of 555 nm light of a wavelength of light, produce the same bright and dark vision are required radiation flux Δξλ and Δξ555nm, then the ratio: ν (λ) = Δξλ / Δξ555 nm is called as See function. Flux (symbol: Φ, Unit: lumens / lm), characterized by visual light intensity per unit of time of light energy through an area known as the radiation energy flux through this area. Absolute black body temperature in the solidification of platinum,coffee neon sign, from 5.305 * 103 cm2 area on the radiation from the luminous flux is 1 lm. |
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