Voltage detecting device

• US 5,034,683 A
• Filed: 01/03/1990
• Issued: 07/23/1991
• Est. Priority Date: 07/13/1987
• Status: Expired due to Term

• Current Assignee: Hamamatsu Photonics KK
• Original Assignee: Hamamatsu Photonics KK
• Inventors: Tsuchiya, Yutaka, Takahashi, Hironori, Aoshima, Shinichiro
• Primary Examiner(s): Karlsen, Ernest F.
• Application Number:
  US07/460,645
• Time in Patent Office: 566 Days
• Field of Search: 324/96, 324/158 R, 324/158 D, 324/73.1, 350/356, 350/374, 350/376
• US Class Current: 324/754.23
• CPC Class Codes: G01R 15/242 based on the Pockels effect, i.e. linear electro-optic effect
• CPC Class Codes: G01R 31/308 using non-ionising electromagnetic radiation, e.g. optical radiation investigating or analysing materials by the use of optical means G01N21/00; image analysis G06T7/00

Abstract

A voltage detecting device for detecting voltages in an object under test including an electro-optic material covering a plurality of parts of the object under test; the refractive index of the electro-optic material being variable according to an applied voltage. A light source emits light through the electro-optic material toward the object under test and a detecting device receives an emergent light beam reflected from within the electro-optic material in order to detect voltages in the object. Further, a scanning device automatically scans the object under test with the light beam in order to detect voltages at a plurality of locations on the object.

Claims

1. A voltage detecting device for detecting voltages in an object to be measured, comprising:

an electro-optic material disposed to cover a plurality of two-dimensional positions of the object to be measured and having a refractive index that varies according to a voltage applied thereto;

means for emitting a parallel light beam toward each of a plurality of two-dimensional parts on said electro-optic material corresponding to said plurality of two-dimensional positions of the object;

detecting means for detecting changes in polarization of an emergent light beam emerging from said plurality of two-dimensional parts of said electro-optic material; and

wherein said emitting means includes a pulse light source emitting light having a short pulse width and said detecting means includes a two-dimensional photo-electric conversion detector for sampling/detecting changes in voltage at said plurality of two-dimensional positions of the object by shifting a timing of application of said light beam to said electro-optic material.

2. A voltage detecting device as claimed in claim 1, further comprising:

a reflecting mirror formed on a bottom surface of said electro-optic material, said reflecting mirror being made of at least one of metal and dielectric multi-layer film.

3. A voltage detecting device for detecting voltages in an object to be measured, comprising:

an electro-optic material disposed to cover a plurality of two-dimensional positions of the object to be measured and having a refractive index that varies according to a voltage applied thereto;

means for emitting a parallel light beam toward each of a plurality of two-dimensional parts on said electro-optic material corresponding to said plurality of two-dimensional positions of the object;

detecting means for detecting changes in polarization of an emergent light beam emerging from said plurality of two-dimensional parts of said electro-optic material;

a bundle of optical fibers arranged to convert a two-dimensional arrangement of said emergent light beam into a one-dimensional arrangement thereof, and to guide said emergent light beam into said high-speed response detector; and

wherein said emitting means includes one of a CW light source and a pulsed light source, and said detecting means includes a high-speed response detector.

4. A voltage detecting device as claimed in claim 3, in which said high-speed response detector is a streak camera.

5. A voltage detecting device for detecting voltages in an object to be measured, comprising:

an electro-optic material disposed to cover a plurality of two-dimensional positions of the object to be measured and having a refractive index that varies according to a voltage applied thereto;

means for emitting a parallel light beam toward each of a plurality of two-dimensional parts on said electro-optic material corresponding to said plurality of two-dimensional positions of the object;

detecting means for detecting changes in polarization of an emergent light beam emerging from said plurality of two-dimensional parts of said electro-optic material;

an observing light source means for emitting a light beam different in wavelength from said pulse light beam through said electro-optic material toward the object to be measured for observation of the wiring pattern in the object to be measured;

switching means for selecting one of said pulse light beam and said light beam to be applied to said electro-optic material;

phase compensator means for adjusting the phase of said emergent light beam to a different phase for detection of changes in polarization of said emergent light beam and for observation of the wiring pattern;

display means for displaying the voltages at said plurality of two-dimensional positions of the object to be measured and the wiring pattern in the object to be measured as detected by said detecting means, the former being superimposed on the latter; and

variable delay means for shifting the emitting timing of said pulse light beam to said electro-optic material for sampling measurement of changes in voltages at said plurality of two-dimensional positions of the object to be measured; and

wherein said emitting means includes a pulse light source means for emitting a pulse light beam having a short pulse width, and said detecting means includes means for detecting a wiring pattern in the object to be measured.

6. A voltage detecting device as claimed in claim 5, further comprising a dielectric multi-layer film mirror formed on the bottom surface of said electro-optic material for transmitting said light beam from said observing light source means and reflecting said pulse light beam from said pulse light source means.

7. A voltage detecting device as claimed in claim 5, wherein said phase compensator means includes means for adjusting the phase of said emergent light beam so as to apply said emergent light beam to said detecting means as it is when the wiring pattern is observed, and means for subjecting said emergent light beam to changes in polarization and for applying said emergent light beam to said detecting means when the voltages in the object to be measured are detected.

8. A voltage detecting device for detecting voltages in an object to be measured, comprising:

an electro-optic material disposed to cover a plurality of two-dimensional positions of the object to be measured and having a refractive index that varies according to a voltage applied thereto;

means for emitting a parallel light beam toward each of a plurality of two-dimensional parts on said electro-optic material corresponding to said plurality of two-dimensional positions of the object;

detecting means for detecting changes in polarization of an emergent light beam emerging from said plurality of two-dimensional parts of said electro-optic material; and

optical means for dividing said light beam into a plurality of incident rays of light arranged in a predetermined pattern, said plurality of incident rays of light being applied to specific portions of said electro-optic material corresponding to specific positions of the object to be measured.

9. A voltage detecting device as claimed in claim 8, wherein said optical means comprises a micro-lens array for dividing said light beam into said plurality of incident rays of light arranged in a lattice pattern.

10. A voltage detecting device as claimed in claim 8, in which said optical means comprises a micro-lens array and a plate-shaped mask disposed over said micro-lens array for dividing said light beam into said plurality of incident rays of light arranged in said predetermined pattern.

11. A voltage detecting device as claimed in claim 8, in which said optical means includes a holographic lens for dividing said light beam into said plurality of incident rays of light arranged in said predetermined pattern.

12. A voltage detecting device as claimed in claim 8, in which said optical means includes a spatial light modulator for dividing said light beam into said plurality of incident rays of light arranged in said predetermined pattern corresponding to an input image thereof.

13. A voltage detecting device as claimed in claim 8, in which said light source means is a pulse light source, and said detecting means is a two-dimensional detector including a photo detector array in which voltages at said specific positions of the object to be measured are detected by sampling.

14. A voltage detecting device as claimed in claim 8, in which said light source is one of a pulse light source and a continuous wave (CW) light source, and said detecting means is a high-speed response detector.

15. A voltage detecting device as claimed in claim 14, in which said high-speed response detector is a streak camera.