There is provided a projection optical system capable of projecting an image formed on an image forming unit on a projection plane, which has an extremely short projection distance and a small size.

Projection systems and/or methods for efficient use of light by recycling a portion of the light energy for future use are disclosed. In one embodiment, a projection display system is disclosed comprising a light source; an integrating rod that receives light from said light source at a proximal end that comprise a reflective surface which may reflecting/recycle light down said integrating rod; of reflecting light down said integrating rod; a relay optical system, said relay optical system further comprising optical elements that are capable of moving the focal plane of the projector display system; and a modulator comprising at least one moveable mirror that reflects light received from the integrating rod in either a projection direction or a light recycling direction.

Based on information about a vehicle, the information can be projected and displayed onto a road surface or the like. An image projection apparatus, which projects an image, includes an acquisition unit that acquires the information about the vehicle, and an image projection unit that projects the image based on the information acquired by the acquisition unit.

Based on information about a vehicle, the information can be projected and displayed onto a road surface or the like. An image projection apparatus, which projects an image, includes an acquisition unit that acquires the information about the vehicle, and an image projection unit that projects the image based on the information acquired by the acquisition unit.

A projection system and a projection method are provided. The projection system includes a projection device, a streaming device, and a control device. The projection device includes a first image input port and a second image input port. The streaming device is electrically connected to the first image input port of the projection device and is coupled to the projection device in a detachable manner. The control device is communicatively connected to the streaming device. The control device transmits a first command signal to the streaming device, so that the projection device projects image data from the streaming device. The projection method may be executed by the projection system. The projection system and the projection method of the disclosure provide a user with more convenient operation environment and operation interface.

A display device (30) comprises a reflective display (38) arranged to render a first image viewable through a viewing surface and a projection means (31-37) arranged to render a second image viewable in reflection on the viewing surface, the reflective display (38) and the projection means (31-37) being mounted on a common frame.

A display device (30) comprises a reflective display (38) arranged to render a first image viewable through a viewing surface and a projection means (31-37) arranged to render a second image viewable in reflection on the viewing surface, the reflective display (38) and the projection means (31-37) being mounted on a common frame.

[Solving Means] A projector includes a first light-emitting side polarization plate, a second light-emitting side polarization plate, a third light-emitting side polarization plate, and a cross dichroic prism. The first light-emitting side polarization plate is arranged on a light-emitting side of a first liquid crystal lightbulb that modulates light of a first wavelength band. The second light-emitting side polarization plate is arranged on a light-emitting side of a second liquid crystal lightbulb that modulates light of a second wavelength band. The third light-emitting side polarization plate is arranged on a light-emitting side of a third liquid crystal lightbulb that modulates light of a third wavelength band. The liquid crystal lightbulb includes a first side surface that light of the first wavelength band enters and opposes the first light-emitting side polarization plate, a second side surface that light of the second wavelength band enters and opposes the second light-emitting side polarization plate, a third side surface that light of the third wavelength band enters and opposes the third light-emitting side polarization plate, and a fourth side surface from which synthetic light obtained from the light of the first wavelength band, the second wavelength band, and the third wavelength band is emitted. At least one of the first light-emitting side polarization plate, the second light-emitting side polarization plate, and the third light-emitting side polarization plate is tilted with respect to the opposing side surface.

A projector according to the present technology includes a blower mechanism, a liquid crystal lightbulb, a light-incident-side polarization plate, and a light-emitting-side polarization plate. The blower mechanism generates a cooling wind. The light-incident-side polarization plate includes a plurality of wires formed to extend non-parallel to the cooling wind blown by the blower mechanism and is arranged on a light-incident side of the liquid crystal lightbulb. The light-emitting-side polarization plate includes a plurality of wires formed to extend non-parallel to the cooling wind blown by the blower mechanism and is arranged on a light-emitting side of the liquid crystal lightbulb.

[Solving Means] A projector according to the present technology includes a lightbulb, a projection section, and a replacement mechanism. The lightbulb modulates light. The projection section projects light modulated by the lightbulb. The replacement mechanism holds a transmissive member arranged on an optical path between the lightbulb and the projection section and is capable of replacing the transmissive member.