Title:
MEASURING APPARATUS FOR SIGNAL WAVEFORM OF PRINTED-CIRCUIT BOARD
Document Type and Number:
Japanese Patent JP3018982
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To obtain a measuring apparatus by which the measurement of a signal in an interconnection coated with a protective film on a printed-circuit board is realized with good accuracy.
SOLUTION: The tip of a metal pin 11 is brought into contact with a part to be measured, and an electric field from the part to be measured is guided to an electrooptical element (E-O element) 5 constituted of a crystal or the like belonging to an isometric system. In addition, a laser beam 2 which is output from a laser diode 1 is reflected by a reflecting mirror 4 so as to be incident obliquely on the E-O element 2 as linearly polarized light. As a result, by a crystal whose refractive index is changed on the basis of the electric field from the part to be measured, the laser beam 2 is reflected from the E-O element 5 whose plane of polarization is changed. The polarization amount of the reflected beam is converted into an electric signal by using an optical system which is composed of a λ/4 plate 7, of a Wollaston prism 8 and of a photodiode 9, and its result is output to a display device.
Inventors:
Hajime Kusumi
Application Number:
JP13716796A
Publication Date:
March 13, 2000
Filing Date:
May 30, 1996
Export Citation:
Assignee:
NEC
International Classes:
G01R1/06; G01R19/00; G01R31/302; G01R15/24; (IPC1-7): G01R31/302; G01R1/06; G01R15/24; G01R19/00
Domestic Patent References:
| JP3167490A | ||||
| JP7146316A | ||||
| JP6102296A | ||||
| JP7181212A | ||||
| JP989940A | ||||
| JP735827A | ||||
| JP8262117A |
Attorney, Agent or Firm:
Naoki Kyomoto (2 outside)