A light source apparatus includes: a phosphor wheel that is provided with a plurality of ring-shaped light-emitting regions that are arranged concentrically and that respectively generate illumination light beams of a plurality of colors when irradiated by excitation light; a light source unit that simultaneously radiates the excitation light to the ring-shaped light-emitting regions; and a plurality of optical elements that are irradiated by the plurality of illumination light beams that are generated due to the irradiation of the excitation light.

A light source apparatus according to an embodiment of the present technique includes a first light source section, a second light source section, a third light source section, and a synthesis section. The first light source section includes a plurality of red laser light sources arranged in an array. The second light source section includes a plurality of green laser light sources arranged in an array. The third light source section includes a plurality of blue laser light sources arranged in an array. The synthesis section synthesizes red laser light emitted from the first light source section, green laser light emitted from the second light source section, and blue laser light emitted from the third light source section to generate white light.

An illumination system provides an illumination beam and includes a red light source, a green light source, a blue light source, a first supplementary light source, a first X-shaped light-splitting assembly, a first light-splitting element, and a light-uniforming element. The red light source provides a red beam. The green light source provides a green beam. The blue light source provides a blue beam. The first supplementary light source provides a first supplementary beam. The first X-shaped light-splitting assembly guides the first supplementary beam and the blue beam to the first light-splitting element. The first light-splitting element guides the red beam, the green beam, the blue beam, and the first supplementary beam to the light-uniforming element. The first supplementary beam is a red supplementary beam or a blue supplementary beam, and the illumination system includes at least five light-emitting elements. A projection apparatus including the above illumination system is also provided.

An optical module of the present disclosure includes a first panel including a first light-emitting element, a first power supply wiring and a second power supply wiring; a second panel including a second light-emitting element having light emission luminance per unit current lower than that of the first light-emitting element, a third power supply wiring and a fourth power supply wiring; and a prism configured to synthesize first image light emitted from the first panel and second image light emitted from the second panel. A first potential difference is smaller than a second potential difference, the first potential difference being a difference between a potential applied to the first power supply wiring and a potential applied to the second power supply wiring, the second potential difference being a difference between a potential applied to the third power supply wiring and a potential applied to the fourth power supply wiring.

The cube polarizer can have modified prism dimensions to satisfy the following equation: $.Math.{\mathrm{OPL}}_T-{\mathrm{OPL}}_R.Math.<\frac{0.5*t*n_p}{\sqrt{2}},$
where an optical path length is a distance of light travel through a material times an index of refraction of the material, OPL.sub.T is an optical path length of the transmitted beam, OPL.sub.R is an optical path length of the reflected beam, t is a thickness of the substrate between the first surface and the second surface of the substrate, and n.sub.p is an index of refraction of the first prism.

An element substrate is formed as a lens array substrate on which a plurality of lenses are formed. In a method of manufacturing the lens array substrate, first recess sections are formed on one surface of the substrate, and then a plurality of lens surfaces, which include concave surfaces, are formed at the bottoms of the first recess sections 195. Subsequently, after a light-transmitting lens layer is formed to fill the inside of the first recess sections, flattening is performed while the lens layer is removed. Here, the surface of the lens layer on a side opposite to the substrate is a planar surface which is contiguous to an outside area that is positioned on the outer side of the first recess sections on the one surface of the substrate.

Described examples include a device having a prism cube having a first side and a second side opposite the first side, the prism cube configured to: receive light comprising a first color light and a second color light, direct the first color light to the first side of the prism cube, and direct the second color light to the second side of the prism cube.

An illumination device comprises a light source that includes a solid-state light source whose peak wavelength is set in the red wavelength band, a light source that includes a solid-state light source whose peak wavelength is set in the green wavelength band, a light source that includes a solid-state light source whose peak wavelength is set in the blue wavelength band, and a color synthesis optical element that combines P-polarized colored light incident from one light source and S-polarized colored light incident from the other two light sources. One light source includes at least one solid-state light source whose peak wavelength is set in the wavelength band of the color corresponding to one of the other light sources.

A projection display device includes: a light modulation unit that spatially modulates, in accordance with image data that has been input, light emitted by a light source; a projection optical system that projects the light that has been spatially modulated onto a projection surface of a vehicle; a measurement information acquisition unit that acquires measurement information measured by an information measuring device; an image display control unit that performs either first display control or second display control as defined herein; and a warning determination unit that determines, in accordance with the measurement information, whether or not a warning is necessary, and the image display control unit performs the second display control when the warning determination unit determines that the warning is necessary, and performs the first display control when the warning determination unit determines that the warning is not necessary.

An optical module in the present disclosure includes a first image display panel including a first display part and a first coupling part, a second image display panel including a second display part and a second coupling part, a third image display panel including a third display part and a third coupling part, and a cross dichroic prism configured to synthesize first, second, and third image light. The cross dichroic prism has a cross axis at which a two of photosynthesis surfaces cross each other. The first, second, and third image display panel are respectively bonded to different surfaces of the cross dichroic prism in a state where a long side of each of the first, second, and third display part extends along the cross axis and where the first, second, and third coupling part are each positioned on an outer side of the cross dichroic prism.