Method of producing switchable holograms

DETAILED DESCRIPTION A method of producing a switchable hologram generally comprises providing a substrate composed of a liquid crystal material and having two generally opposed surfaces and recording a plurality of holographic fringes composed of liquid crystal droplets in the substrate with one or more of the plurality of holographic fringes positioned such that a surface of the fringes is angled relative to one of the substrate surfaces.
The substrate is subjected to an electrical field during recording of the holographic fringes.
The electrical field varies across the surface of the substrate so that the liquid crystal droplets are all oriented generally in a common direction.
Recording of the holographic fringes may further include interposing the hologram between a pair of electrodes each positioned generally adjacent to one of the substrates surfaces.
One of the pair of electrodes has a plurality of independently controlled segments.
Each of the segments is positioned over an area of the substrate having holographic fringes positioned within a common range of angles relative to the substrate surface.
A pair of glass carriers may be interposed between the electrodes and the substrate surfaces.
The above is a brief description of some deficiencies in the prior art and advantages of the present invention.
Other features, advantages, and embodiments of the invention will be apparent to those skilled in the art from the following description, drawings, and claims.