Document Type and Number:
Japanese Patent JPS5552417
Kind Code:
Y2
Abstract:
A screen means free from ghost image comprising a screen and Fresnel lens arranged so that its Fresnel surface faces the screen. The Fresnel lens is arranged that optically inactive surfaces of its Fresnel surface become approximately parallel with the advancing direction of projected rays entered through and refracted by the back surface of the Fresnel lens.
Application Number:
JP15509976U
Publication Date:
December 05, 1980
Filing Date:
November 18, 1976
Export Citation:
International Classes:
G02B3/08; G03B21/62; (IPC1-7): G03B21/60
Previous Patent: JPS5552416
Next Patent: METHOD OF CONTROLLING TO PREVENT BRINE FROM COUNTERFLOWING AT RIVER-MOUTH DAM
Next Patent: METHOD OF CONTROLLING TO PREVENT BRINE FROM COUNTERFLOWING AT RIVER-MOUTH DAM