Meter with light transmitting board
US5915822A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 8, 1997 |
| Grant date | Jun 29, 1999 |
| Priority date | — |
| Expiry date | Aug 8, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S385/901
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A transmitted illumination type meter comprises a transparent light transmitting board having both a light entering bore and a shaft passing bore formed therethrough; a translucent dial plate placed on a front surface of the board, the dial plate having a shaft passing opening mated with the shaft passing bore of the board; a movement positioned behind the board; a light source positioned within the light entering bore; a drive shaft extending from the movement to the outside of the dial plate through the shaft passing bore and the shaft passing opening; a transparent pointer connected to the drive shaft to move over a front surface of the dial plate; and an annular convex peripheral wall defining the light entering bore. The annular convex peripheral wall allows light beams from the light source to enter the board and travel in parallel in the same. A plurality of stepped annular light reflecting surfaces are formed on a rear surface of the board and arranged to be concentric with the light entering bore. The annular light reflecting surfaces reflect the light beams from the annular convex peripheral wall toward the front surface of the light transmitting board. A Fresnel lens is …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.