Electronic watch and display device for such watch

• US 4,183,628 A
• Filed: 05/13/1977
• Issued: 01/15/1980
• Est. Priority Date: 05/20/1976
• Status: Expired due to Term

• Current Assignee: Ebauches SA
• Original Assignee: Ebauches SA
• Inventors: Saurer, Eric, Viennet, Rene, Laesser, Claude
• Primary Examiner(s): Bauer, Edward S.
• Application Number:
  US05/796,525
• Time in Patent Office: 977 Days
• Field of Search: 58/50 R, 350/338, 350/345, 350/334, 350/339
• US Class Current: 349/65
• CPC Class Codes: G02F 1/13324 Circuits comprising solar cells
• CPC Class Codes: G02F 1/1335 Structural association of cells with optical devices, e.g. polarisers or reflectors
• CPC Class Codes: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side
• CPC Class Codes: G04C 10/02 the power supply being a radioactive or photovoltaic source
• CPC Class Codes: Y10S 136/291 Applications

Abstract

An electro-optic display device having a partially transparent display cell and a semi-transparent mirror located behind said cell and arranged to transmit light waves within a first wave length band and to reflect light waves within a second wave length band. An electro-optic component is located behind the semi-transparent mirror and operates in a third wave length band which overlaps at least partially the first wave length band. The electro-optical component may be a plurality of photo cells used for recharging an accumulator for the display device and/or a light source transmitted across a light plate of frosted or clear glass to illuminate the display cell. The display cell is illuminated by either the reflected light waves or the light waves emitted from the light source.

Claims

1. A combination liquid crystal display and electrical generator comprising, a partially transparent liquid crystal display cell having front and rear surfaces for viewing from the front;

a plurality of photoelectric cells located to the rear of said display cell and sensitive to light waves within a first frequency band corresponding to at least the color red; and

a semi-transparent mirror located between said display cell and said photoelectric cells and adaped to transmit light waves within a second frequency band including wave lengths corresponding to at least the color red and reflect light waves within a third frequency band including wave lengths corresponding to at least the color blue, whereby the reflected light in the third frequency band corresponds to the band of light to which the human eye is most sensitive for maximizing the brightness of the display, and the transmitted light in the second frequency band corresponds to the band of light to which the photocells are most sensitive for maximizing the energy produced by the photoelectric cells.

2. The combination of claim 1, further comprising a frost glass located between said mirror and said photoelectric cells.

3. The combination of claim 1, further comprising a diffuser member located between said display cell and said mirror.

4. The combination of claim 1, wherein said semi-transparent mirror is a dielectric mirror.