PROJECTION TYPE VIDEO DISPLAY DEVICE

• Main Author: YAMAMOTO NORIKAZU
• Format: Patent
• Language: English; Japanese
• Published: 30.11.2022
• 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; PHOTOGRAPHY; PHYSICS

To provide a projection type video display device that can reduce stray light to an image pickup device.SOLUTION: A projection type video display device of the present disclosure comprises: a video light emitting section; a projection lens unit; a light path separation prism that has a first prism, a second prism, and a polarization separation film; a narrow band phase difference plate; and an image pickup device that picks up an image of external light through the projection lens unit and the light path separation prism. The polarization separation film transmits light in a first polarization state being any one of a P-polarization and an S-polarization and reflects light in a second polarization state being the other of the P-polarization and the S-polarization. The video light is incident on the light path separation prism from a first surface of the first prism, transmits through the polarization separation film, emits from a third surface of the second prism, and is incident on the projection lens unit. The external light is emitted from the projection lens unit and is incident on the light path separation prism from the third surface of the second prism, and the polarization separation film reflects light in the second polarization state of the external light. The external light is internally totally reflected on the third surface of the second prism, emitted from a fifth surface, and received by the image pickup device.SELECTED DRAWING: Figure 1 【課題】撮像素子への迷光を低減することのできる投写型映像表示装置を提供する。【解決手段】本開示の投写型映像表示装置は、映像光出射部と、投写レンズユニットと、第１プリズムと、第２プリズムと、偏光分離膜と、を有する光路分離プリズムと、狭帯域位相差板と、投写レンズユニットおよび光路分離プリズムを介して外部光を撮像する撮像素子と、を備え、偏光分離膜は、Ｐ偏光およびＳ偏光のいずれか一方の第１の偏光状態の光を透過させ、Ｐ偏光およびＳ偏光のいずれか他方の第２の偏光状態の光を反射し、映像光は、第１プリズムの第１面から光路分離プリズムに入射し偏光分離膜を透過して第２プリズムの第３面から出射して投写レンズユニットに入射し、外部光は、投写レンズユニットから出射され、第２プリズムの第３面から光路分離プリズムに入射して偏光分離膜で外部光のうち第２の偏光状態の光を反射し、第２プリズムの第３面で内部全反射して第５面から出射して、撮像素子で受光される。【選択図】図１