Abstract A liquid crystal display is operable in transmission or reflection modes to provide a high level of readability over a range of ambient light extending from total darkness to full sunlight illumination. Liquid crystal material is confined between front and rear spaced apart transparent plates provided with inner surfaces having conductive coatings formed in predetermined display patterns. The rear plate is coated with one or more layers of material that provide for the transmission of light through it and also for the reflection of ambient light directed through the front of the display. A back illumination light is provided behind the rear plate which is energized either manually or automatically when the ambient light level in front of the display falls below a predetermined level.
The display unit of claim 1 including manual switch means for operating said light source.
Claim 2
Dependent Claim
41 words
The display unit of claim 1 including switch means connected to a power lead for said light source and an ambient light sensor mounted in said housing for actuating said switch means when the ambient light decreases to a predetermined level.
Claim 3
Dependent Claim
16 words
The display unit of claim 1 wherein said dual-mode layer is a partially reflecting metallic material.
Claim 4
Dependent Claim
24 words
The display unit of claim 4 wherein said dual-mode layer is a partially reflecting layer of aluminum having a thickness of around 400 angstroms.
Claim 5
Dependent Claim
26 words
The display unit of claim 4 wherein said dual-mode layer is a partially reflecting layer comprised of titanium dioxide having a thickness of around 1,000 angstroms.