Transparent screen, projection display device, and method of receiving control signal light
AssigneeMitsubishi Electric Corporation
InventorsTakao Endo, Yuzo Nakano, Hayato Takeuchi
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Abstract
A transparent screen is constructed in such a way that a plurality of Fresnel prisms 12d each of which is smaller than a plurality of Fresnel prisms 12a and has a shape approximately similar to that of each of the plurality of Fresnel prisms 12a are arranged in a sawtooth shape on a non-light incidence surface portion of a Fresnel lens 12 on a light incidence side to which any image light PB applied from a projector 1 is not applied directly because blocked by a Fresnel prism 12a placed frontwardly.
Claims5
A transparent screen including a Fresnel optical element in which a plurality of Fresnel prisms each having a refractive surface for refracting a light ray applied thereto from a light emitting body and a reflecting surface for reflecting the light ray refracted by said refractive surface are arranged in a sawtooth shape, wherein
- a plurality of Fresnel prisms each of which is smaller than said plurality of Fresnel prisms and has a shape approximately similar to that of each of said plurality of Fresnel prisms are arranged in a sawtooth shape on a non-light incidence surface portion of said Fresnel optical element to which any light ray applied from said light emitting body is not applied directly because blocked by a Fresnel prism placed frontwardly.
A projection display device equipped with a light emitting body for applying a light ray which is image light, and a transparent screen for receiving the light ray applied thereto from said light emitting body, and for emitting said light ray in a predetermined direction, wherein
- said transparent screen includes a Fresnel optical element in which a plurality of Fresnel prisms each having a refractive surface for refracting the light ray applied thereto from said light emitting body and a reflecting surface for reflecting the light ray refracted by said refractive surface are arranged in a sawtooth shape, and wherein a plurality of Fresnel prisms each of which is smaller than said plurality of Fresnel prisms and has a shape approximately similar to that of each of said plurality of Fresnel prisms are arranged in a sawtooth shape on a non-light incidence surface portion of said Fresnel optical element to which any light ray applied from said light emitting body is not applied directly because blocked by a Fresnel prism placed frontwardly.
A method of receiving control signal light which is applied from remote operation equipment to and then emitting toward a light receiver from a transparent screen including a Fresnel optical element in which a plurality of Fresnel prisms each having a refractive surface for refracting a light ray applied thereto from a light emitting body and a reflecting surface for reflecting the light ray refracted by said refractive surface are arranged in a sawtooth shape, wherein
- said method includes the step of applying the control signal light from said remote operation equipment to said transparent screen and then emitting the control signal light from said transparent screen toward the light receiver by arranging a plurality of Fresnel prisms each of which is smaller than said plurality of Fresnel prisms and has a shape approximately similar to that of each of said plurality of Fresnel prisms in a sawtooth shape on a non-light incidence surface portion of said Fresnel optical element to which any light ray applied from said light emitting body is not applied directly because blocked by a Fresnel prism placed frontwardly.
Dependencies are inferred from the claim text.