发明名称 Projection type image display apparatus
摘要 A projection-type display apparatus, comprises a front lens group having a plural number of lenses, each having rotationally symmetric surface configuration, a rear lens group, being disposed in rear of the front lens group, including a refractive lens for diverting a light and having a rotationally symmetric surface configuration, and a plural number of free curved surface lenses, each having a rotationally asymmetric free curved surface configuration, and a reflection mirror, being disposed in rear of the rear lens group, having a convex configuration into a direction of reflection of light and a rotationally asymmetric free curved surface configuration, at least in a part thereof.
申请公布号 US7701639(B2) 申请公布日期 2010.04.20
申请号 US20070870646 申请日期 2007.10.11
申请人 HITACHI, LTD. 发明人 HISADA TAKANORI;HIRATA KOJI;YATSU MASAHIKO
分类号 G02B3/00;G02B3/02;G02B9/00;G02B13/18 主分类号 G02B3/00
代理机构 代理人
主权项
地址