Patent · US Expired

Lighting device with central symmetry for a dial

US7038976B2 · kind B2 · utility

8Cited by
12References
14Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 21, 2005
Grant dateMay 2, 2006
Priority date
Expiry dateSep 21, 2025

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG04G9/0041
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A light source (15) is housed in a housing (6) of a case, underneath the dial (10) opposite a guide (17) directing the light onto a reflector (20), formed in a hollow in the internal or external face of a crystal (1) the thickness of which decreases regularly from the center to the periphery thereof for reorienting the light by total internal reflection into the crystal (1) until it emerges towards the dial (10) when the maximum refractive index is exceeded.

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