Sharp Kabushiki Kaisha Corporation

Nemoto & Company, Ltd.

Kaori Kanesaka

Kiyoshi Suzuki

Tetsuya Hanamoto

Wataru Takase

Tomokazu Sagara

Yasushi Aoki

Nobuyoshi Takeuchi

Takashi Murase

Takeshi Takahara

Yuzo Ishikawa

It is an object of the present invention to provide an infra-red light emitting phosphor having an excellent chemical stability and desirable light emitting properties. The infra-red light emitting phosphor is represented by a chemical formula: (ANdYb)VO, wherein A represents at least one element selected from yttrium (Y), gadolinium (Gd), lutetium (Lu) and lanthanum (La); x and y respectively satisfy the requirements: 0.01&#x2266;x&#x2266;0.3 and 0.01&#x2266;y&#x2266;0.4, provided that (x+y)&#x2266;0.5 and 0.2&#x2266;(y/x)&#x2266;6. This vanadate phosphor having the constitution described above can act as an infra-red light emitting phosphor having an excellent chemical stability and desirable light emitting properties.

Infra-red light emitting phosphor

A semiconductor light-emitting device has a semiconductor light-emitting element for emitting light with emission wavelengths of 390 to 420 nm, wherein the wavelengths of light from the semiconductor light-emitting element are converted by a fluorescent substance having a monochromatic emission peak. The emission wavelengths of 390 to 420 nm, which have almost no adverse effect on human bodies and components of the semiconductor light-emitting device, are in a low human visibility range. Since light whose wavelengths are converted by the fluorescent substance are hardly affected by direct light from the semiconductor light-emitting element, light from the fluorescent substance has a favorable color tone. Also, the semiconductor light-emitting device allows desired luminous colors to be obtained only by changing fluorescent substance materials without changing the structure of the semiconductor light-emitting device or the semiconductor light-emitting element.

Semiconductor light-emitting device and light-emitting display therewith

Semiconductor light-emitting device and light-emitting display device therewith

An information reading method includes the steps of irradiating a phosphor activated by neodymium and ytterbium ions with exciting light of a wavelength between 500 nm and 780 nm that can excite the neodymium ions, and reading the information by receiving the light emitted from the phosphor with a photodetector designed to detect light with wavelengths between 840 m and 1100 nm. Consequently, the information recorded using the phosphor activated by neodymium and ytterbium ions can be read with a high performance without using a filter for cutting the exciting light.

Information reading method

Growing community of inventors

Tokyo, Japan

Kaori Kanesaka