qvu464h5w
wózek dziecinny
Dołączył: 23 Lut 2011
Posty: 9
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Skąd: England
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 Wysłany: Nie 3:48, 01 Maj 2011 Temat postu: control phosphor ratio |
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The two issues raised by Mr. Liu is currently a lot of R & D staff is very concerned about packaging factory technical problems, as people on the human visual health awareness, high color rendering white LED product has large market demand, and the low high color temperature white LED color rendering is a difficulty.
In this, I reply as follows: high-low color temperature color scheme are: (1) The preparation of high-chip RGB trichromatic color white LED; (2) using InGaN blue LED excitation RGY phosphors were prepared by high color white LED; (3) using UV-LED excitation Preparation RGB color phosphor white LED. Since paragraph (1) program costs are relatively high (3) Technical and temporarily mature, so the market mainly in subsection (2) program. Cree, C adopt such programs.
To prepare the color temperature 2700-3500K, luminous flux greater than 82lm, while higher color rendering index Ra of 80, individuals that need to do the following: (1) accurate measurement of phosphor excitation and emission spectra, and to study the phosphor and chips emission spectrum of the matching; (2) control phosphor ratio, the low color temperature white LED with high color rendering to maintain a continuous spectrum; (3) choice of a good red phosphor, the luminous efficiency and attenuation control.
For high-power white LED spot, I personally think that the main improvement programs and the way the phosphor coating. The current way of phosphor coating are: conformal coating, spraying,[link widoczny dla zalogowanych], evaporation, fluid dispensing,[link widoczny dla zalogowanych], electrophoresis. 2008 Fifth China International Semiconductor Lighting Forum, Asymtek dispensing the company introduced the fluid (fluid dieing) of the phosphor coating method, which can not only improve the consistency of high-power white LED can also improve the product of the spot results.
At present, many domestic manufacturers to adopt the only way the general dispensing, so there will be a yellow circle and other undesirable phenomena spot. In addition,[link widoczny dla zalogowanych], some engineers use to make spot changes spread powder evenly.
Second problem: the color coordinates and the correlated color temperature conversion relationship between how? A: According to CIE chromaticity diagram, we know: It is known to calculate the correlated color temperature and color coordinates,[link widoczny dla zalogowanych], correlated color temperature can be calculated given isotherm.
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