Electronic rule for precise distance measurement and distance setting

US4158229A · kind A · utility

Inventors

• John Woo · Huntsville, US
• Yeong-Chung E. Lien · Lawrence, US

Key dates

• Filing date: Jun 24, 1977
• Grant date: Jun 12, 1979
• Expiry date: Jun 24, 1997

Classification

• Technology area (CPC G): Physics
• CPC primary: G01B11/02
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An instrument for precise measurement and setting of distances has an electronically controlled scale comprising optically active elements, an electronically controlled digital display, and a keyboard. The display and keyboard are mechanically rotatable and connected by electronic circuitry including a microprocessor. The light scale provides optical indicia, including a reference point and a cursor, having positions which are determined by keyboard entries and are displayed numerically.