Lighting apparatus changing aspect ratio of screen and projection type image display apparatus provided with the lighting apparatus
View Patent ↗A lighting apparatus is provided with a light source unit including laser diode elements, a collimating lens, and at least one optical element changing only a predetermined one-axis direction of a traveling direction of the substantially parallel light. When the substantially parallel light is incident on a first surface of the optical element, the optical element reflects the substantially parallel light by a second surface to change only the one-axis direction of the traveling direction of the substantially parallel light, and emits an inclined light flux inclined from the substantially parallel light. An aspect ratio of a screen configured by spot lights from the light source unit is changed to an aspect ratio on a cross section of a predetermined position in a traveling direction of the inclined light flux.
1. A lighting apparatus comprising:
a light source unit including a plurality of laser diode elements arranged in two dimensions;
a collimating lens disposed in front of the light source unit, the collimating lens converting a light flux emitted from each of the laser diodes into substantially parallel light; and
at least one optical element disposed in front of the collimating lens, the optical element changing only a predetermined one-axis direction of a traveling direction of the substantially parallel light,
wherein the optical element has optical transparency, and has a first surface perpendicular to the substantially parallel light and a second surface inclined from the first surface, and
wherein, when the substantially parallel light is incident on the first surface of the optical element, the optical element reflects the substantially parallel light by the second surface to change only the one-axis direction of the traveling direction of the substantially parallel light, and emits an inclined light flux inclined from the substantially parallel light, and
wherein an aspect ratio of a screen configured by a plurality of spot lights from the light source unit is changed to a predetermined aspect ratio on a cross section of a predetermined position in a traveling direction of the inclined light flux.
2. The lighting apparatus as claimed in claim 1 , wherein the at least one optical element is configured by a first triangular prism.
3. The lighting apparatus as claimed in claim 1 ,
wherein the at least one optical element is configured by a plurality of first triangular prisms, and
wherein each of the first triangular prisms is shifted for at least one laser diode element of the light source unit, from the traveling direction of the substantially parallel light from the collimating lens.
4. The lighting apparatus as claimed in claim 1 , further comprising a reduced optical system that collects the converted light flux and changes light beam angles in vertical and horizontal directions of the collected light flux.
5. The lighting apparatus as claimed in claim 1 , further comprising a second triangular prism provided at a predetermined position in a traveling direction of the inclined light flux, and further changing the traveling direction of the inclined light flux.
6. The lighting apparatus as claimed in claim 1 ,
wherein the plurality of optical elements is arranged so as to face only a part of the plurality of laser diode elements of the light source unit, and
wherein the lighting apparatus emits an inclined light flux passing through the plurality of optical elements, and an inclined light flux not passing through the plurality of optical elements.
7. A projection type image display apparatus comprising:
a lighting apparatus;
a light modulation apparatus modulating light emitted from the lighting apparatus in accordance with image information to form image light; and
a projection optical system projecting the image light,
wherein the lighting apparatus comprises:
a light source unit including a plurality of laser diode elements arranged in two dimensions;
a collimating lens disposed in front of the light source unit, the collimating lens converting a light flux emitted from each of the laser diodes into substantially parallel light; and
at least one optical element disposed in front of the collimating lens, the optical element changing only a predetermined one-axis direction of a traveling direction of the substantially parallel light,
wherein the optical element has optical transparency, and has a first surface perpendicular to the substantially parallel light and a second surface inclined from the first surface, and
wherein, when the substantially parallel light is incident on the first surface of the optical element, the optical element reflects the substantially parallel light by the second surface to change only the one-axis direction of the traveling direction of the substantially parallel light, and emits an inclined light flux inclined from the substantially parallel light, and
wherein an aspect ratio of a screen configured by a plurality of spot lights from the light source unit is changed to a predetermined aspect ratio on a cross section of a predetermined position in a traveling direction of the inclined light flux.