POLARIZING ELEMENT, LIGHT SOURCE FOR POLARIZED LIGHT AND LIQUID CRYSTAL DISPLAY DEVICE

摘要

PURPOSE: A light source device for polarized light using a dichroic polarizing element and a reflection type polarizing element is provided to effectively use light in a liquid crystal display device using the light source device for polarized light. CONSTITUTION: A reflection type polarizing element(52) and a dichroic polarizing element(51) are arranged with the transmission axes for polarized light coincident with each other on an optical path to constitute a composite type polarizing device(80). The dichroic polarizing element(51) show >= 44% transmittance T(P)(λ) and >= 50% polarization degree P(P)(λ) at the wavelength λ between 400 nm and 700 nm or shows >= 44% luminosity-corrected transmittance Y(P) and >= 50% luminosity-corrected polarization degree P(P, y). The light source device(40) for polarized light is composed of the polarizing device(80), a light source member(60) disposed in the reflection polarizing element(51b) side of the device(80), and a reflection plate(63) disposed in the opposite side of the light source member(60) to the polarizing device(80). Further, the light source device(40) for polarized light is disposed on the back face of a liquid crystal cell(20) to constitute the liquid crystal display device(10).