公开(公告)号：JPS63241366A

公开(公告)日：1988-10-06

申请号：JP7553087

申请日：1987-03-27

Applicant: NGK INSULATORS LTD

Inventor： TOYODA SHUHEI ,  MATSUZAWA MOTOICHIRO ,  ICHISE MASAHIRO

IPC: G01R15/24 ,  G02F1/03

Abstract: PURPOSE:To enable highly accurate measurement to a measuring voltage without being affected by an external electric field such as electrostatic charge or the like, by shielding at least an electrooptical element portion composing an optical part from the external electric field. CONSTITUTION:Light from an optical fiber 1 is introduced to an electrooptical element 4 in which a measuring voltage is applied between electrodes 5 and 5 through a rod lens 2 and a polarizer 3. After passing through a wavelength plate 7, light turned to an elliptically polarized light is reflected with a mirror 8 and passes again through the wavelength plate 7 and the electrooptical element 4. Then, it passes through the polarizer 3 to be taken out through the optical fiber 1 from a rod lens 2 to measure the quantity of light. In a reflection photovoltage sensor of such a type, a sensor body portion 12 is housed as closed in a metal case 13 as conductor comprising a conductive metal plate such as copper plate. The metal case 13 is electrically connected to a lead 6 to an electrode 5 of the electrooptical element 4 composing the sensor body portion.