Patent ID: 6768529
Filing Date: 2004-07-27
Classification: G02B,G02F

Abstract:
A reflection-transmission double type liquid-crystal display device comprising:a transmission type liquid-crystal display panel including a liquid-crystal cell; at least one illuminator disposed on at least one of side surfaces of said liquid-crystal display panel and capable of being switched on/off; an optical path changing sheet which has a refractive index exhibiting a refractive index difference of not higher than 0.15 from a refractive index of a nearest liquid-crystal cell substrate, and which is bonded onto a back side opposite to a visual side of said liquid-crystal display panel through an adhesive layer having a refractive index exhibiting a refractive index difference of not higher than 0.20 from the refractive index of said nearest liquid-crystal cell substrate; and a reflection layer disposed on a back side of said optical path changing sheet, wherein said optical path changing sheet has continuous first optical path changing slopes, second optical path changing slopes and flat surfaces, each of said first optical path changing slopes faces said illuminator at an inclination angle in a range of from 30 to 48 degrees with respect to a plane of said optical path changing sheet for reflecting incident light from said illuminator toward said visual side of said liquid-crystal display panel, each of said second optical path changing slopes faces away from said illuminator at an inclination angle which is less than 90 degrees with respect to a plane of said optical path changing sheet and is greater than said inclination angle of said first optical path changing slopes, and each of said flat surfaces is inclined at an inclination angle of not larger than 10 degrees with respect to said sheet plane so that a projected area of said flat surfaces on said sheet plane is not smaller than 10 times as large as a projected area of said first optical path changing slopes on said sheet plane.