Luminous hands and display device including the same, particularly in a timepiece
US7038975B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 9, 2002 |
| Grant date | May 2, 2006 |
| Priority date | — |
| Expiry date | Oct 30, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG04B19/32
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
There is provided a type of luminous hand including a part made of moulded transparent material that forms a circular head (28, 35) and a body (28, 34) of a hand. In order to direct a portion of a light beam parallel to the axis (15) of the hand towards the interior of the body, the head includes a plurality of reflectors (40, 41) distributed around the axis and formed by dihedron shaped hollows. This improves the intensity and uniformity of the light in the hand body. Inclined light-diffusing surfaces, covered with a light coloured paint, are arranged on the bottom face of the hand. In a display device with several coaxial hands (11,12) such as that of a watch, the reflectors of the superposed heads (29, 35) of the hands are located at respective distances from the axis which are different from one hand to another, such that they never completely cover each other. The light source preferably includes three light-emitting diodes (23) located under the dial (10). A cylindrical light guide (18) is placed between the source and the heads of the hands, in the central opening in the dial.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.