BACKPROJECT TYPE DISPLAY DEVICE,申请号JP19890181253-传众专利搜索

BACKPROJECT TYPE DISPLAY DEVICE

申请公布号：JPH0345988(A)

申请号：JP19890181253

申请日期：1989.07.13

申请公布日期：1991.02.27

申请人：

CANON INC

发明人：YANAGI HARUYUKI;MINOURA NOBUO

分类号：G03B21/62;G02F1/1335;G03B21/10;G09F9/00

主分类号：G03B21/62

摘要：PURPOSE:To suppress a contrast decrease and ghost by providing a means which cuts off unnecessary light on the image-light incidence side of a Fresnel lens. CONSTITUTION:Cathod-ray tubes(CRT) 3 exclusively for red, green, and blue are arranged successively and lenses 2 are also arranged in front of the CRTs 3 one to one. Images displayed on those CRTs 3 are projected on a screen 1 at an angle theta of incidence slantingly from above. Then an eccentric Fresnel lens 1a is provided with the light shielding means 6 extending in the prolonga tion direction of each prism and this light shielding means 6 cuts off unnecessary light other than projection light, such as reflected light as between the screen 1 and mirrors 4a and 4b and reflected light as in the lens barrel of the lens 2. Consequently, an image of high picture quality whose contrast decreases, ghost, etc., is suppressed can be observed on the screen 1.