Seiko Epson Corporation

Tohoku University

Osamu Arakawa

Toshiaki Hashizume

Tatsuo Uchida

Baku Katagiri

Yoshito Suzuki

Hiroyuki Shindo

Kunihiko Takagi

Tetsuo Shimizu

Satoshi Kito

Wataru Yasumatsu

Tomohiro Yokoo

A phosphor according to the present disclosure includes a first crystal phase added with an activator agent, a second crystal phase higher in thermal conductivity than the first crystal phase, and a third crystal phase which is disposed between the first crystal phase and the second crystal phase, and is same in crystal structure as the first crystal phase, and is smaller in additive amount of the activator agent than the first crystal phase.

Phosphor, wavelength conversion element, light source device, and projector

A ceramic composite according to the present disclosure has a phosphor phase containing an activator and a phosphor and a matrix phase containing MgO as a light transmissive ceramic material. The ceramic composite is made of an inorganic material, and the content of the phosphor phase is so set that the volume ratio of the phosphor phase to the entire phase including the matrix phase and the phosphor phase is lower than or equal to 20 vol %.

Ceramic composite, light source apparatus, and projector

A wavelength converter according to the present disclosure includes a wavelength conversion layer that has a first surface and a second surface different from the first surface and converts excitation light that belongs to a first wavelength band into fluorescence that belongs to a second wavelength band different from the first wavelength band, a first light transmissive member that has a third surface on which the excitation light is incident and a fourth surface different from the third surface and transmits at least the excitation light, and a first layer provided between the first surface of the wavelength conversion layer and the fourth surface of the first light transmissive member, which are surfaces facing each other. The refractive index of the first light transmissive member is greater than the refractive index of the wavelength conversion layer, and the first layer transmits the excitation light and reflects the fluorescence.

Wavelength converter, light source apparatus, and projector

A wavelength converter according to an aspect of the present disclosure includes a wavelength conversion layer that converts excitation light in terms of wavelength to generate fluorescence, and a first reflection member that reflects the fluorescence and is so provided as to incline with respect to a light exiting surface which is a surface of the wavelength conversion layer and via which the fluorescence exits.

A light source apparatus according to an aspect of the present disclosure includes an excitation light source and a wavelength converter including a transparent phosphor and a base. The wavelength converter has a light incident area, a first area, and a second area, and the wavelength converter includes a second reflector (angle changer) provided in a portion corresponding to the second area.

Light source apparatus and projector

A wavelength conversion element includes a base material and a phosphor layer that contains a phosphor emitting fluorescence upon incidence of excitation light and is provided on the base material, in which the phosphor layer includes a first surface on which excitation light (blue light) is incident and a second surface facing the base material, and a plurality of regions with different absorption coefficients of the excitation light between the first surface and the second surface.

Wavelength conversion element, light source device, and projector

A light source device includes a phosphor layer having a side surface, a bottom surface, and an upper surface opposed to the bottom surface, a substrate disposed on the bottom surface side of the phosphor layer, and a reflecting member disposed outside the phosphor layer. The phosphor layer generates fluorescence in response to irradiation with excitation light. The fluorescence generated in the phosphor layer is emitted from the upper surface and the side surface. The fluorescence emitted from the side surface enters the reflecting member.

Light source device and projector

A screen in which observation distance may be adjusted while maintaining image brightness and a projection system using the screen. In a light control layer of a screen, a first angle region that determines a diffusion distribution of a reflected light is different according to the screen position in a control direction in which light diffusion control is performed. Accordingly, a diffusion distribution of image light emitted from a screen surface is adjusted to be tilted downward by an upper end and upward by a lower end according to the screen position. Thus, for example, a size of a diffused angle range is maintained to be 30&#xb0;, and a direction in which the image light is diffusion-emitted corresponds to an assumed position of an observer. The projection image can be observed while maintaining brightness of an image and the observation distance L can be adjusted to be short.

Screen and projection system

A screen which reflects light emitted from a projector includes a light diffusion layer through which light incident from a specific angular region is diffused and transmitted and through which light incident from the other angular region is transmitted straight; area pairs having a mirror forming area and a non-mirror forming area; a light transmissive layer having a back surface, on which the area pairs are disposed, and an opposite surface being bonded to a back side of the light diffusion layer; and a specular reflection film formed on a back surface of each mirror forming area. An inclination of the mirror forming area with respect to a normal line of the screen close to the projector becomes larger than the inclination of the mirror forming area far from the projector within a cross section perpendicular to the mirror forming areas inside the screen.

Growing community of inventors

Shiojiri, Japan

Osamu Arakawa