Kabushiki Kaisha Toshiba

Toyoda Gosei Co., Ltd.

Tomokazu Kitajima

Koichi Nitta

Hiroaki Oshio

Nozomu Takahashi

Kenji Shimomura

Toshiya Uemura

Yuji Takahashi

Koichi Ota

A light emitting device, free from change of color even when the wavelength of a light emitting element shifts, includes a light emitting element () for emitting primary light having an intensity peak at a wavelength shorter than 400 nm; a silicone resin () provided to embed the light emitting element; and a fluorescent element () contained in the silicone resin to absorb the primary light and release visible light.

Light emitting device

An LED and a photo-diode are arranged such that they are optically coupled with each other. The first terminal to which a power supply voltage is applied is connected to the anode of the LED. Between the cathode of the LED and the second terminal for outputting an output signal, there is provided a constant current circuit for allowing a constant current to flow into the LED. To the cathode of the LED, connected is the collector of an NPN transistor, to the emitted of which the second terminal is connected. Light emitted from the LED is detected and converted into an current signal by the photo-diode. The current signal generated by the photo-diode is amplified by an amplifying circuit. A signal output from this amplifying circuit is supplied to the base of the NPN transistor, thereby controlling ON/OFF operation of the transistor. Between the second terminal and the ground point located outside the device, connected is a load resistor.

Photo-interrupter operating on wide-ranged power voltage with a constant

Growing community of inventors

Kitakyushu, Japan

Tomokazu Kitajima