Abstract: This projection display device includes: a light source unit emitting a white light along a first optical axis; a lighting unit provided on a second optical axis, the lighting unit splitting the white light into predetermined color lights and uniformizing an illuminance distribution of the predetermined color lights; an image generator including a display element modulating the predetermined color lights, and a projection lens projecting an image light including the predetermined color lights modulated along a third optical axis; at least one optical path switching unit selectively switching between reflection and transmission of the white light; a light diffuser including a diffusion optical system spreading the white light to a desired illumination area and projecting the spread white light as an illumination light; and a controller causing the at least one optical path switching unit to switch between emission of the image light and emission of the illumination light.

Abstract: This projection display device includes: a light source unit emitting a white light along a first optical axis; a lighting unit provided on a second optical axis, the lighting unit splitting the white light into predetermined color lights and uniformizing an illuminance distribution of the predetermined color lights; an image generator including a display element modulating the predetermined color lights, and a projection lens projecting an image light including the predetermined color lights modulated along a third optical axis; at least one optical path switching unit selectively switching between reflection and transmission of the white light; a light diffuser including a diffusion optical system spreading the white light to a desired illumination area and projecting the spread white light as an illumination light; and a controller causing the at least one optical path switching unit to switch between emission of the image light and emission of the illumination light.

Abstract: A light source device includes first and second light source units, a first polarization beam splitter, and a polarization conversion element. The first light source unit emits first linear polarization light in a first direction. The second light source unit is disposed facing the first light source unit, and emits the first linear polarization light in a second direction opposite to the first direction. The first linear polarization light emitted from the first light source unit is reflected by the first polarization beam splitter in a third direction perpendicular to the first and second directions. The first linear polarization light emitted from the second light source unit is reflected by the first polarization beam splitter in a fourth direction opposite to the third direction, is converted into the second linear polarization light by the polarization conversion element, and is reflected in the third direction.

Abstract: A light source device includes first and second light source units, a first polarization beam splitter, and a polarization conversion element. The first light source unit emits first linear polarization light in a first direction. The second light source unit is disposed facing the first light source unit, and emits the first linear polarization light in a second direction opposite to the first direction. The first linear polarization light emitted from the first light source unit is reflected by the first polarization beam splitter in a third direction perpendicular to the first and second directions. The first linear polarization light emitted from the second light source unit is reflected by the first polarization beam splitter in a fourth direction opposite to the third direction, is converted into the second linear polarization light by the polarization conversion element, and is reflected in the third direction.

Abstract: A head-up display causes light modulated by an optical modulation element to form, via a projection lens, an intermediate image on a screen, and then causes the intermediate image to reflect, via a mirror, on a windshield to allow a user to view a virtual image. A normal line of the screen is inclined with respect to an optical axis of the projection lens. An emission surface of the optical modulation element is inclined with respect to the screen and a principal plane of the projection lens so as to satisfy a Scheimpflug condition.

Abstract: A head-up display includes an image light output device for outputting image light, a first optical element, a second optical element, and a third optical element. The first optical element is provided to be inclined with respect to the output surface of the image light output device. The first optical element reflects the image light having a first polarization direction and allowing the image light having second polarization direction to pass through. The second optical element reflects the image light from the first optical element to the first optical element. The third optical element is disposed between the first and the second optical element, and converts the image light having the first polarization direction to the image light having the second polarization direction by allowing the image light to pass through back and forth. The image light passing through the first optical element is projected on a combiner.

Abstract: A head-up display causes light modulated by an optical modulation element to form, via a projection lens, an intermediate image on a screen, and then causes the intermediate image to reflect, via a mirror, on a windshield to allow a user to view a virtual image. A normal line of the screen is inclined with respect to an optical axis of the projection lens. An emission surface of the optical modulation element is inclined with respect to the screen and a principal plane of the projection lens so as to satisfy a Scheimpflug condition.

Abstract: A head-up display includes an image light output device for outputting image light, a first optical element, a second optical element, and a third optical element. The first optical element is provided to be inclined with respect to the output surface of the image light output device. The first optical element reflects the image light having a first polarization direction and allowing the image light having second polarization direction to pass through. The second optical element reflects the image light from the first optical element to the first optical element. The third optical element is disposed between the first and the second optical element, and converts the image light having the first polarization direction to the image light having the second polarization direction by allowing the image light to pass through back and forth. The image light passing through the first optical element is projected on a combiner.

Abstract: Provided is a projection image display apparatus that can restrict crosstalk between a left eye image and a right eye image. The projection image display apparatus includes a liquid crystal element that switches polarization of the light emitted from the optical modulation element between a first polarization and a second polarization, and a waveplate that is provided between the liquid crystal element and the projection surface. The waveplate includes a plurality of areas having different slow axes or fast axes from each other.

Abstract: The projection display apparatus comprises: an image control unit configured to control a second viewpoint image of the plurality of viewpoint images to suppress crosstalk of a first viewpoint image. The image control unit controls a suppression amount of crosstalk according to a position on the projection plane.

Abstract: An optical element includes: a first dichroic mirror; and a pair of second dichroic mirrors, wherein the first dichroic mirror includes a first mirror surface and a first main surface; the pair of second dichroic mirrors each includes a second mirror surface and a second main surface; one second dichroic mirror of the pair of second dichroic mirrors is disposed on the first mirror surface in such a way that the second mirror surface is perpendicular to the first mirror surface; the other second dichroic mirror of the pair of second dichroic mirrors is disposed on the first main surface in such a way that the second mirror surface is perpendicular to the first main surface; and a gradation process for adjusting a spectral characteristic within the first mirror surface is applied only for the first mirror surface.

Abstract: A projection display apparatus comprising: a housing member that accommodates an illumination optical unit; a projection optical unit; and a cooling unit, wherein the housing member includes a layout space in a virtually columnar shape having a bottom that is a circumscribed circle of the projection optical unit in a cross sectional view vertical to the projection optical unit; the layout space includes a first layout space in a substantially conical shape and a second layout space excluding the first layout space; the projection optical unit is provided in the first layout space; and at least a part of the illumination optical unit and the cooling unit is provided in the second layout space; and the illumination optical unit and the cooling unit are disposed in a symmetrical positional relationship with respect to the projection optical unit.