A projector includes a main body and a projection lens. The main body includes a light source, liquid crystal panels that modulate light outputted from the light source, and a lens holder to and from which the projection lens is attachable and detachable. The projection lens projects the light modulated, and the lens holder includes a first lens holding mechanism and a second lens holding mechanism that hold the projection lens.

The application relates to the technical field of projection, and discloses a projection device which can improve the brightness of projection imaging. Part of the projection device comprises: an LED light source, a color wheel, a light-equalizing rod, a convex lens, a first Fresnel lens, an LCD panel and a projection lens; a ray of target light emitted by the LED light source emits a target alternating light through the color wheel, and the target alternating light comprises five monochromatic lights including red light, green light, blue light, yellow light and white light, and the five monochromatic lights enter the light-equalizing rod for uniform treatment to emit an uniform light spot, the uniform light spot is imaged at the first Fresnel lens through the convex lens, then irradiated into the LCD panel, and projected by the projection lens.

A phase difference compensation element, including: a transparent substrate; a first optical anisotropic layer that includes an inorganic material, and has a C-plate retardance; and a second optical anisotropic layer that includes an inorganic material, and includes an oblique angle vapor deposition film that does not have an O-plate retardance, wherein the phase difference compensation element including the first optical anisotropic layer and the second optical anisotropic layer in combination has a quasi-O-plate retardance.

An image display apparatus according to an embodiment of the present technology includes an optical modulator, an optical device, and a sensor unit. The optical device splits a modulated light beam modulated by the optical modulator into a first split light beam and a second split light beam, the first split light beam and the second split light beam each travelling in a different direction, and prevents a light beam, which backwardly travels on an optical path of the first split light beam and enters the optical device, from travelling along an optical path of the second split light beam. The sensor unit is disposed on the optical path of the second split light beam and detects a state of the second split light beam.

An optical system of a semi-vertical single LCD (liquid crystal display) projector includes a projection light source, a condenser, an illuminating reflector, a collimating lens, a heat reflecting glass, an LCD light valve, a field lens, an imaging reflector and a projection lens, all of which are set in sequence according to a direction of light, wherein the illuminating reflector reflects and turns light irradiating the LCD light valve in up and down directions, and the imaging reflector performs mirror reflection and turning on light emitted by the LCD light valve in left and right directions. The present invention obtains a new optical system structure, creates a novel stacking and a novel projector appearance, and has low cost, small size and complete integration.

A light source apparatus includes a plurality of light emitting apparatuses. Each of the light emitting apparatuses includes a plurality of light emitting devices each of which has a light emitting area and a non-light emitting area on an emission surface thereof that emits light. At least two light emitting apparatuses of the light emitting apparatuses constitute a light emitting apparatus group disposed such that the emission surfaces of the respective light emitting apparatuses are parallel to each other with a predetermined distance, and that a distance between light emitting areas of the respective light emitting apparatuses when viewed along a direction perpendicular to the emission surfaces of the at least two of the light emitting apparatuses is shorter than a distance between the light emitting areas of the respective light emitting apparatuses when the emission surfaces of the respective light emitting apparatuses are on the same plane.

In a display device, when blue (B) light enters a first liquid crystal panel, radiated light radiated from the first liquid crystal panel contains red (R) phosphorescence having a wavelength range longer than blue (B) light due to a deterioration of a liquid crystal material. Thus, in the display device, an optical sensor device is provided behind a mirror comprised of a dichroic mirror to monitor or the like the service life of the first liquid crystal panel on the basis of a result of reception, at the optical sensor device, of light having a frequency band ranging from 600 nm to 650 nm, and makes notification of the result. Furthermore, on the basis of a result from the optical sensor device, an electrode used to suck impurities provided at the first liquid crystal panel is driven to sweep ionic impurities from a display region.

A projector includes a first cooling device configured to cool a first cooling target based on transformation of a refrigerant into gas, a second cooling device configured to cool a second cooling target, and a heat conduction member. A refrigerant generator of the first cooling device includes a moisture absorbing and desorbing member, a first blower, a heat exchanger, and a second blower configured to send the air to the heat exchanger. The second cooling device includes a third blower and a circulation path through which the air circulates between the third blower and the second cooling target. The heat conduction member includes a heat absorber configured to absorb heat radiated from the second cooling target and a heat dissipator disposed on the inside of the first cooling device. The heat radiated from the heat dissipator is transferred to the moisture absorbing and desorbing member.

A liquid-crystal display device includes a pair of substrates, a liquid-crystal material layer sandwiched between the pair of substrates, and an optical compensation element having an optical compensation layer, the optical compensation layer including a stack group in which high-refractive-index obliquely deposited films and low-refractive-index obliquely deposited films are alternately deposited, the high-refractive-index obliquely deposited films and the low-refractive-index obliquely deposited films having a same tilt direction with respect to a normal line of a surface on which the films are deposited.

In a liquid crystal device, a first pixel area is provided in a pixel area of a first substrate, and a second pixel area is provided between the first pixel area and a seal material. The first pixel area has a first pixel electrode to which an image signal is applied, the image signal having a potential alternately switching between a positive polarity and a negative polarity with reference to a first central potential. The second pixel area includes a second pixel electrode to which a first driving potential is applied, the first driving potential having a potential alternately switching between a positive polarity and a negative polarity with reference to a second central potential, the first central potential and the second central potential having a potential difference set therebetween. Therefore, ionic impurities can be efficiently swept from the first pixel area to the second pixel area.