Patent · US Expired

Electronic level

US6108920A · kind A · utility

13Cited by
2References
5Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJan 27, 1998
Grant dateAug 29, 2000
Priority date
Expiry dateJan 27, 2018

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01C15/06
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

In an electronic level in which a leveling rod is collimated to convert the result of collimation into an image signal in the form of an electric signal and then graduated numerical values are automatically recognized as characters to thereby compute the collimated position, recognition cannot be made with small graduated numerical values when the distance between a telescope 1 and the leveling rod is large. If the graduated numerical values are enlarged, recognition can neither be made when the distance is small because the graduated numerical values go beyond the field of view. As a solution, two kinds of large and small graduated numerical values A, B are indicated on the leveling rod. From the pitches of graduation patterns M1, M2 in the image signals, the distance between the telescope and the leveling rod is obtained. Then, depending on the distance, the graduated numerical value to be recognized is selected out of the graduated numerical values A, B.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.