CONTRAST IMPROVING DEVICE HAVING HIGH TRANSMITTANCE

摘要

PURPOSE: To improve contrast without reducing the brightness of an image by interrupting a circularly polarized component in peripheral light obtained from an image source by a λ/4 retarder and allowing a straight polarized component to pass λ/4 retarder without attenuating it. CONSTITUTION: Image light from a polarized image source 11 in the polarized light display device 10 is transmitted through a λ/4 retarder 13. Circularly polarized image light through the retarder 13 forms an image as scattered circular image light to be observed on a screen 19 by an observer (driver) through a projection lens 15 and a visual field lens 17. Light from the screen 19 is transmitted through a circular polarizer 21 including a λ/4 retarder 21a. Thereby display light from the scattered screen 19 is transmitted through the polarizer 21 without being substantially attenuated and transmitted to the screen 19 by the polarizer 21 and the reflected peripheral light is substantially interrupted by the polarizer 21. Consequently contrast is improved by the minimum attenuation of display light.