|
TFT LCD screens are so universal because of the image quality and the fact these screens can be manufactured very small without sacrificing image quality. This article will cover the basic performance characteristics and some technical properties of TFT LCD screens as well.
Photometry and Colorimetry
Displays, such as the TFT LCD display, create images within the visible spectrum. This spectrum is transferred from the electronic display to the eye. The visible spectrum, or light, is one of the forms of electromagnetic waves. The wavelengths for the visible spectrum are in the range of 380-780 nm. The intensity of electromagnetic waves is expressed mW/cm2.
The curve below shows the photopic spectral luminous efficiency, or the eye response curve. This diagram shows how the human eye is sensitive to only a part of the spectrum.
The brightness of an LCD display is measured by luminance, or Lum, which is expressed in photometric units:
In laments terms, luminance means the brightness in which light is being emanating from a surface. Luminance is often mistaken as illuminance, which is the total luminous flux incident on a surface, per unit area.
Illuminance is measured in lux, or footCandle (fC). Illuminace is relevant because 1 fC on a perfect diffuse white reflection leads to 1 footLambert of luminance coming from a surface. Obviously, these two have a relation, but are two different things.
Colorimetry is the science of measuring color and is based on experiments with the human eye. To describe color and luminance, one can use three independent variables found during the experiments. The three variables are X, Y and Z.
Where X + Y + Z = 1; thus two chromatic coordinates specify a color.
The Chromaticity Diagram
In 1931 the International Commission on Illumination (CIE) created a diagram to display the color mixtures that are visible to the human eye.
The human eye has three receptors, the short (S), middle (M) and long (L) wavelengths; these are known as blue, green and red receptors. Basically this means a person needs 3 parameters to describe a color sensation.
The triangle within the curve (the gamut) represents the color performance of a color display. When two of the three colors are turned off, the primary colors can be obtained. The primary colors are the three extreme points of the chromaticity. Depending on how many grey levels are present, the mixture of all three primary colors allows for intermediate colors to be displayed.
Back To Resource Center
|
Check
My
Watch our new 
Please ask about our 1-year Extended Warranty
1 (800) 834-4172 
+61 (0) 2 8003-5237
