Fiber faceplate suspended particle display
AssigneeHewlett-Packard Development Company, L.P.
InventorLaurence M. Hubby JR.
Life of this patent
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Abstract
The present invention replaces liquid crystal light control elements in fiber-optic faceplate liquid crystal displays (LCD) with suspended particle devices (SPDs), and provides for passive light control without the need for either polarized light or special alignment layers. A fluid or film containing suspended particles may be asymmetric in shape so that their optical density depends strongly upon their orientation. The orientation of the particles within the fluid can be manipulated by an application of an electric field, so that the fluid or film may appear to be transparent to both polarizations of light when the electric field is applied, and opaque when the electric field is removed and the orientation of the particles is allowed to randomize naturally.
Claims20
A visual image display, comprising:
- a fiber-optic faceplate comprising:
- an upper face;
- a lower face;
- and
- a multiplicity of straight optical fibers positioned between the upper face and the lower face of the faceplate;
- wherein longitudinal axes of the optical fibers are parallel to each other and substantially perpendicular to the upper face and the lower face of the faceplate;
- and
- wherein each of the fibers collects and projects through the faceplate a plurality of light rays emitted by an ambient light source;
- and
- a layer of suspended particle device (SPD) positioned underneath the lower face of the faceplate, wherein the layer of SPD comprises:
- particles suspended in droplets of a liquid light valve suspension, wherein the particles are capable of absorbing or reflecting the plurality of light rays;
- and
- a pair of electrodes positioned in contact with opposite surfaces of the layer of SPD, wherein orientations of the particles depend on an application of an electric field to the electrodes.
A visual image display, comprising:
- a fiber-optical faceplate through which light can pass;
- a layer of suspended particle device (SPD) positioned underneath the faceplate, wherein the layer of SPD comprises:
- particles suspended in droplets of a liquid light valve suspension, wherein the particles are capable of absorbing or reflecting the plurality of light rays;
- and
- a pair of electrodes positioned in contact with opposite surfaces of the layer of SPD;
- wherein orientations of the particles depend on an application of an electric field to the electrodes;
- and
- a transparent conductive layer coated underneath the faceplate and on top of the layer of SPD.
A visual image display, comprising:
- a fiber-optic faceplate comprising:
- an upper face;
- a lower face;
- and
- a multiplicity of straight optical fibers positioned between the upper face and the lower face of the faceplate;
- wherein longitudinal axes of the optical fibers are parallel to each other and substantially perpendicular to the upper face and the lower face of the faceplate;
- and
- wherein each of the fibers collects and projects through the faceplate a plurality of light rays emitted by an ambient light source;
- a layer of suspended particle device (SPD) positioned underneath the lower face of the faceplate, wherein the layer of SPD comprises:
- particles suspended in droplets of a liquid light valve suspension, wherein the particles are capable of absorbing or reflecting the plurality of light rays;
- perimeter seals at both end of the layer of SPD;
- and
- a pair of electrodes in contact with opposite surfaces of the layer of SPD;
- wherein orientations of the particles depend on an application of an electric field to the electrodes;
- and
- wherein the layer of the SPD becomes substantially transparent to the plurality of light rays when the electric field is applied, and substantially opaque when the electric field is removed;
- and
- a transparent conductive layer coated underneath the lower face of the faceplate and on top of the layer of SPD.
Dependencies are inferred from the claim text.