Luminous flux

Since the energy for one photon at this wavelength is 3.6 x 10- J, then the number of photons represented by 1 lumen is approximately 4 X 10i per second, radiated or received. Thus, the luminous flux (lumens, Im) gives the power radiating from an object or the power received by an object. 

The conversion of radiated power (P in watts) to luminous flux (F in lumens) is achieved by considering the variation with wavelength of the human eye s photopie response. Then the spectral power from the source (PA in, lor example, W/nnt) is convoluted with the relative spectral response of the eye (V tabulated by the CIE) according to ... 

The optoelectrical characteristics of the display have been measured using an integrating sphere and a calibrated photodetector connected to a radiometer [30]. First, the total luminous flux from the AM-PLED was measured for different /data. Then, the AM-PLED luminance was calculated from the measured display luminous flux. For a Lambertian emitter, the luminance (L) can be calculated from the measured luminous flux (<1>) by using the following equation ... 

The estimated luminance values (L(iisp ay and L,.mi ior) at maximum luminous flux are about 50 and 120 cd/m2, respectively. These values can be increased similarly through optimization of a-Si H TFTs AM-PLED design and fabrication methods. 

Luminous flux Illuminance Luminance Luminous intensity... 

Radiant intensity can be described as the amount of power (watt) heading in your direction, i.e., per steradian, from a light source. The total amount of power emitted by the source is the radiant flux (watt). If you integrate the radiant intensity over all solid angles, you get the total radiant flux. If it is weighted by the photopic response, then it is the luminous intensity and the luminous flux. 

The SI unit of luminous flux, abbreviated hn. One lumen is the amount of luminous flux emitted in a unit solid angle of one steradian by a uniform point source having a luminous intensity of one candela. 2. The interior space of a tubular structure such as an intestine or artery. 

Luminance is the luminous flux emitted per unit solid angle or per unit projected area of a surface in a light source it is a measure of brightness. 

LUMEN (lin). A unit of luminous flux. Thefiux through a unit solid angle (steradian) from a uniform point source of 1 candela. (The SI unit of luminous flux.)... 

Using these sensitivities, we can calculate the luminous flux of any light source (International Commission on Illumination 1983 Jahne 2002). Let (/,) be the radiant flux at wavelength X of the light source. Let V (X) be the sensitivity of scotopic vision and V(X) be the sensitivity of photopic vision, then the intensity of the light source is... 

Another method of expressing color is in terms of luminance, dominant wavelength, and excitation purity. These latter are roughly equivalent to the three recognizable attributes of color lightness, hue, and saturation. Lightness is associated with the relative luminous flux, reflected or transmitted. Hue is associated with the sense of redness, yellowness, blueness, and so forth. Saturation is associated with the strength of hue or the relative admixture with white. The combination of hue and saturation can be described as chromaticity. 

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