Ushio Denki Kabushiki Kaisha

Kentaro Fujita

Takanori Samejima

Nobuhiko Sugihara

Takashi Yamashita

Tomoyoshi Arimoto

Yoshihiro Horikawa

Tetsuji Hirao

Tetsu Okamoto

Kazuhiro Yoshida

The purpose of the present invention is to make it possible to output stable light by optimizing the wavelength conversion efficiency in a wavelength conversion element without employing an optical detection device such as a photo diode in a laser light source device. A fundamental light wave emitted from a semiconductor laser () is wavelength converted by a wavelength conversion element () and is emitted therefrom. A lighting circuit () supplies electric power for the aforementioned semiconductor laser () to turn on the semiconductor laser (). A control unit () controls the operation of the device while controlling the amount of power supplied to a heater means () such that the wavelength conversion element () reaches a temperature at which optimum wavelength conversion efficiency is acquired. The temperature detected by a temperature detection means (Th) is input to the control unit (), and the control unit () defines the temperature of the wavelength conversion element () at which the maximum amount of power is supplied to the heater means () as a set temperature at which the optimum wavelength conversion efficiency is acquired, and performs feedback control of the temperature of the wavelength conversion element () so that the temperature of the wavelength conversion element () reaches the aforementioned set temperature by controlling the amount of heat supplied from the heater means ().

Laser light source apparatus and temperature control method of wavelength conversion element in laser light source apparatus

The wavelength of fundamental wave light emitted from a semiconductor laser is converted by a wavelength conversion element, and the wavelength-converted light is emitted. A power supply circuit feeds electric power to the semiconductor laser. A control part controls an amount of electric power to be fed to a heater such that the wavelength conversion element becomes a temperature that optimizes the wavelength conversion efficiency. Temperatures detected by an element temperature detector and a light source part temperature detector are introduced to the control part, and the control part takes a wavelength conversion element temperature, at which a temperature detected by the light source part temperature detector is minimum, as a set temperature that makes the wavelength conversion efficiency optimal, and feedback-controls the wavelength conversion element temperature such that the wavelength conversion element temperature is at the set temperature by controlling the heating quantity of the heater.

Laser light source apparatus, and method for controlling temperature of wavelength conversion element in laser light source apparatus

A discharge lamp lighting apparatus includes a discharge container, a pair of electrodes and a power supply apparatus. An alternating current of a frequency, which is lower than stationary frequency, is inserted periodically into the alternating current of stationary frequency. When a lighting current value of the discharge lamp is smaller than a predetermined lower limit, the frequency is set as predetermined minimum frequency. When the lighting current value of a discharge lamp is larger than a predetermined maximum value, the frequency is set as predetermined maximum frequency. When a lighting current value of the discharge lamp is between the lower limit and the maximum value, the frequency is set as a selected frequency corresponding to the lighting current value. The selected frequency increases according to an increase of frequency change as a lighting current value increases.

High pressure discharge lamp lighting apparatus

Growing community of inventors

Hyogo, Japan

Kentaro Fujita