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.

Provided is a particulate phosphor including a single crystal having a composition represented by a compositional formula (Y.sub.1-x-y-zLu.sub.xGd.sub.yCe.sub.z).sub.3+aAl.sub.5−aO.sub.12 (0≤x≤0.9994, 0≤y≤0.0669, 0.001≤z≤0.004, −0.016≤a≤0.315) and a particle diameter (D50) of not less than 20 μm. Also provided is a light-emitting device including a phosphor-including member that includes the phosphor and a sealing member including a transparent inorganic material sealing the phosphor or a binder including an inorganic material binding particles of the phosphor, and a light-emitting element that emits a blue light for exciting the phosphor.

The invention provides a method and a system for controlling a projector. The control method includes: obtaining a first trigger rule and a first to-be-executed action corresponding to the first trigger rule. The first trigger rule and the first to-be-executed action respectively include at least one of a plurality of combinable elements. The control method includes: determining whether the first trigger rule is satisfied and controlling the projector to execute the first to-be-executed action when the first trigger rule is determined as being satisfied. The control system includes a projector and a control device configured to execute the control method. The control method and system of the invention provide more diverse and flexible rules and action generation mechanisms, thereby implementing effects of product differentiation and intelligent operation.

A microelectromechanical structure includes a body of semiconductor material having a fixed frame internally defining a cavity, a mobile mass elastically suspended in the cavity and movable with a first resonant movement about a first rotation axis and with a second resonant movement about a second rotation axis, orthogonal to the first axis. First and second pairs of supporting elements, extending in cantilever fashion in the cavity, are rigidly coupled to the frame, and are piezoelectrically deformable to cause rotation of the mobile mass about the first and second rotation axes. First and second pairs of elastic-coupling elements are elastically coupled between the mobile mass and the first and the second pairs of supporting elements. The first and second movements of rotation of the mobile mass are decoupled from one another and do not interfere with one another due to the elastic-coupling elements of the first and second pairs.

A light-source optical system includes a wavelength converter on which light of first color is incident, the wavelength converter converting at least a part of the light of first color into light of second color different from the light of first color, a first optical system disposed upstream from the wavelength converter on an optical path of the light of first color, the first optical system including optical elements, a reflection plane disposed downstream from the first optical system on the optical path, and a second optical system disposed downstream from the reflection plane on the optical path. The reflection plane reflects one of the light of first color and the light of second color, and a conditional expression “0<ΔL/D<0.2” is satisfied.

An optical system includes a light source configured to emit irradiation light, an optical modulation element having a plurality of reflection planes by which an incident light is reflected in a different direction, and an optical element having an interface through which the irradiation light emitted from the light source is emitted to the optical modulation element as the incident light and a first exit light reflected by the optical modulation element in a first direction is guided to a projection surface. Each one of the plurality of reflection planes is inclined with reference to a surface of the optical modulation element to reflect the incident light as the first exit light, and the surface of the optical modulation element is inclined with reference to the interface.

An information processing apparatus includes a first detector configured to detect an object based on captured image information generated by an image capturing apparatus; a second detector configured to, in response to the object being detected by the first detector, detect a user operation carried out with regard to the object, the user operation involving a change in a state of the object; and a display controller configured to, in response to the user operation being detected by the second detector, generate an image that is associated with the object and the user operation, to display the generated image on a display apparatus.

A prism block includes a first prism having first, second and third surfaces, a second prism having a fourth surface parallel to the first surface, a fifth surface facing the second surface, and a sixth surface, a third prism having seventh and eight surfaces respectively facing the second and fifth surfaces, and an optical path separation coating disposed between the fifth and eighth surfaces. Illumination light incident on the third surface is reflected by the second surface, and is emitted from the first surface. Projection light incident on the first surface is emitted from the fourth surface. Imaging light incident on the fourth surface is reflected by the optical path separation coating, and is emitted from the sixth surface. A projection axis plane including optical paths of the illumination light and the projection light, and an imaging axis plane including an optical path of the imaging light intersect each other.

In an electro-optical device, a first polarizing element, a first phase difference element, a transmissive liquid crystal panel, a second phase difference element, and a second polarizing element are sequentially arranged. Here, when a phase difference of the first phase difference element and the second phase difference element is λ/4, an influence of orientation disorder of liquid crystal molecules can be alleviated, but a contrast ratio is reduced. Therefore, when a wavelength of incident light is λ, a phase difference R of the first phase difference element and the second phase difference element satisfies the following condition that 0<R<λ/4, preferably λ/12<R<λ/6. For example, it is assumed that the phase difference R is λ/8.

A projector including a light source, a first prism, a second prism and a digital micro-mirror device (DMD) is provided. The light source emits light. The first prism includes a first surface, a second surface and a third surface which are connected to each other around the perimeter thereof, and the illumination light enters the first prism through the first surface. The second prism has a fourth surface and a fifth surface which are connected to each other, and the fourth surface faces the second surface of the first prism. The DMD faces the third surface. The illumination light sequentially passes through the first surface, is reflected by the second surface, passes through the third surface, and reaches the DMD. The DMD converts the illumination light into image light, and the image light sequentially passes through the third surface, the second surface, the fourth surface and the fifth surface. In the first prism, a first included angle between the first surface and the third surface is more than or equal to 105 degrees.