Title:
INCLINATION DETECTOR
Document Type and Number:
WIPO Patent Application WO/1990/001678
Kind Code:
A1
Abstract:
An inclination detector for electrically detecting the angle of inclination of an object to be measured relative to a horizontal or gravitational direction. Conventional inclination detectors involve large errors in the measured result because of change in the bubble diameter due to a temperature change, in the intensity of light in the light emitting portion, and in the photo-electric conversion sensitivity of a light-receiving element. Furthermore, since the bubble is of spherical shape, the sensitivity decreases as the angle of inclination increases and whereby the measuring range becomes narrow and correction is needed to obtain a correct angle of inclination. To solve such assignments of the conventional inclination detectors, this invention provides an inclination detector comprising a bubble tube which contains a gas and a transparent liquid in a transparent container whose upper inner surface has a spherical concave shape, a light emitting portion which sends light toward said bubble tube from the upper or lower direction, a light-receiving element which converts the light that has passed through the bubble tube into electric signals, and an arithmetic unit that calculates the angle of inclination from said electric signals, wherein the light-receiving element is constituted by a position detecting light-receiving portion within a moving range of bubble shadow and reference light-receiving portion outside the moving range, and said position detecting light-receiving portion has a pair of rectangular light-receiving pieces that are so arranged that the center lines thereof are in agreement with each other in the lengthwise direction in which the inclination is to be detected, the rectangular light-receiving pieces having an equal width which is smaller than the diameter of the bubble shadow.
Inventors:
SHIMURA KIKUO (US)
Application Number:
PCT/JP1989/000792
Publication Date:
February 22, 1990
Filing Date:
August 01, 1989
Export Citation:
Assignee:
SOKKISHA (JP)
International Classes:
G01C9/00; G01C9/06; G01C9/36; (IPC1-7): G01C9/06; G01C9/24; G01C9/26; G01C9/32; G01C9/36
Foreign References:
| JPS60252215A | 1985-12-12 | |||
| SU485308A1 | 1975-09-25 | |||
| SU504086A1 | 1976-02-25 |
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