Energy efficient transflective display
An energy efficient transflective display system is disclosed. In one embodiment, the system comprises a reflector sheet and a transparent backlight sheet placed in front of the reflector sheet. A display panel is placed in front of the transparent backlight sheet where the display panel has a light valve.
1. An apparatus, comprising
a reflector sheet,
a light source in the form of a sheet that allows ambient light to pass through it placed in front of the reflector sheet, and
a display panel placed in front of the light source in the form of a sheet, the display panel having a light valve; wherein
the light source in the form of a sheet comprises a transparent light guide with a varying concentration of light dispersing particles, and
the transmittance of a pixel of the light valve is approximately set to the value (−B+sqrt (B^2+8AL))/2A where
‘sqrt’ is the square root function,
^ stands for the square root function,
B is intensity of light falling on the light valve from the light source in the form of a sheet,
A is intensity of ambient light falling on the light valve and
L is a required illumination intensity of the pixel.
2. The apparatus of claim 1 , further comprising color filters.
3. The apparatus of claim 1 , wherein the light valve comprises a liquid crystal sheet situated between polarizer sheets.
4. The apparatus of claim 1 , wherein the reflector sheet includes one or more of: a metallic surface, a distributed Bragg reflector, a hybrid reflector, a total internal reflector, an omni-direction reflector, and a scattering reflector.
5. The apparatus of claim 1 , further comprising a partial mirror sheet placed between the display panel and the light source in the form of a sheet.
6. The apparatus of claim 1 , further comprising a manual control that adjusts light source power.