| 摘要 |
<p>PURPOSE:To cause no sensitivity variation of an optical sensor, which follows a wavelength variation of a light source even if a temperature is varied by using two LEDs having each different center wavelength, in an electricity quantity measuring device which makes an optical output of the LED incident to the optical sensor and utilized its polarized light. CONSTITUTION:A pair of LEDs 81, 82 whose center wavelengths lambda1, lambda2 are different from each other and whose spectrum widths A1, A2 are the same are formed on a light source 80, and optical outputs from the LEDs 81, 82 are coupled by an optical coupler 90 and become a light whose spectrum distribution is extremely narrow, through a BPF100. This light is made incident to an optical sensor 20 provided with an electro-optical effect element 23, etc. for bringing a light to an elliptical polarization in accordance with voltage E to be measured. A sensitivity variation of an optical sensor, which follows a wavelength variation of a light source is not caused even if a temperature is varied, by an incident light in which the width of this spectrum distribution is narrower than the varied width of a wavelength of a light by a variation of a temperature, and the quantity of electricity such as voltage, etc. is measured exactly.</p> |
