PROJECTION OPTICAL SYSTEM AND PROJECTION DISPLAY DEVICE

• Main Author: AMANO MASARU
• Format: Patent
• Language: English; Japanese
• Published: 21.06.2018
• Subjects: ACCESSORIES THEREFOR; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USINGWAVES OTHER THAN OPTICAL WAVES; APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FORPROJECTING OR VIEWING THEM; CINEMATOGRAPHY; ELECTROGRAPHY; HOLOGRAPHY; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; PHOTOGRAPHY; PHYSICS

PROBLEM TO BE SOLVED: To provide a projection optical system for forming an intermediate image, which features compactness, a wide angel, good aberration correction, and high optical performance, and to provide a projection display device having the same.SOLUTION: A projection optical system consists of a first optical system G1 for forming an image of an image displayed on an image display element as an intermediate image, first light path bending means R1 for bending a light path using a reflective surface, and a second optical system G2 for forming an image of the intermediate image on a conjugate plane on the expansion side, in order from the reduction side. The second optical system G2 comprises a first lens group G21 having positive refractive power, second light path bending means R2 for bending the light path using a reflective surface, and a second lens group G22 having positive refractive power, in order from the reduction side. The system satisfies the following conditional expressions: 10.0<TL1/|f|<50.0 ...(1), 4.0<TL21/|f|<30.0 ...(2), where TL1 represents a distance from a most reduction-side surface to a most expansion-side surface of the first optical system on an optical axis, and TL21 represents a distance from a most reduction-side surface to a most expansion-side surface of the first lens group on the optical axis.SELECTED DRAWING: Figure 1 【課題】中間像を形成する投写用光学系において、小型化を達成しつつ、広角で諸収差が良好に補正された高い投写性能を有する投写用光学系およびこの投写用光学系を備えた投写型表示装置を提供する。【解決手段】縮小側から順に、画像表示素子上の画像を中間像として結像させる第１光学系Ｇ１と、反射面で光路を折り曲げる第１光路折り曲げ手段Ｒ１と、中間像を拡大側共役面上に結像する第２光学系Ｇ２からなり、第２光学系Ｇ２は、縮小側から順に、正の屈折力を有する第１レンズ群Ｇ２１と、反射面で光路を折り曲げる第２光路折り曲げ手段Ｒ２と、正の屈折力を有する第２レンズ群Ｇ２２からなり、条件式（１）１０．０＜ＴＬ１／｜ｆ｜＜５０．０、（２）４．０＜ＴＬ２１／｜ｆ｜＜３０．０を満足する。式中、ＴＬ１は第１光学系の最縮小側面から最拡大側面までの光軸上の距離、ＴＬ２１は第１レンズ群の最小側面から最拡大側面までの光軸上の距離を表す。【選択図】図１