Edge-illuminated liquid crystal display devices
First Claim
1. A liquid crystal display device, comprising:
- liquid crystal display panel means including;
a polymer dispersed liquid crystal film having positive dielectric anisotropy liquid crystal;
electrode layers formed on opposite surfaces of a predetermined area of the liquid crystal film for creating an electric field for switching the liquid crystal film in said predetermined area for viewing at normal incidence between a light transmissive state and a light scattering state in response to the presence or absence respectively of an applied electrical potential; and
front and back transparent face plates which sandwich the liquid crystal film and electrode layers therebetween;
light source disposed external of and adjacent to a light-receiving edge of the display panel means for illuminating the display panel means through said edge thereof, said light source comprising first and second optical lamps for illuminating the display panel means through said light receiving edge and an edge opposite to said light-receiving edge thereof respectively, andfirst and second light diffusing means disposed between the first and second optical lamps and said respective edges of the display panel means.
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Accused Products
Abstract
A high contrast display is provided by illuminating a polymer dispersed liquid crystal (PDLC) display panel through opposite edges thereof. Light is scattered out the front of the panel from non-activated areas of the PDLC in which the refractive indices of the liquid crystal and polymer matrix materials are mismatched. For a direct view transmission mode display, the rear of the panel is blackened so that activated areas of the PDLC in which the refractive indices of the materials are matched transmit edge-illuminated and ambient light and appear black. For a reflection mode display usable in combination with projection optics, the rear of the panel is provided with a mirror surface, and ambient light is prevented from reaching the panel.
181 Citations
9 Claims
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1. A liquid crystal display device, comprising:
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liquid crystal display panel means including; a polymer dispersed liquid crystal film having positive dielectric anisotropy liquid crystal; electrode layers formed on opposite surfaces of a predetermined area of the liquid crystal film for creating an electric field for switching the liquid crystal film in said predetermined area for viewing at normal incidence between a light transmissive state and a light scattering state in response to the presence or absence respectively of an applied electrical potential; and front and back transparent face plates which sandwich the liquid crystal film and electrode layers therebetween; light source disposed external of and adjacent to a light-receiving edge of the display panel means for illuminating the display panel means through said edge thereof, said light source comprising first and second optical lamps for illuminating the display panel means through said light receiving edge and an edge opposite to said light-receiving edge thereof respectively, and first and second light diffusing means disposed between the first and second optical lamps and said respective edges of the display panel means. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A liquid crystal display device, comprising:
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liquid crystal display panel means including; a polymer dispersed liquid crystal film having positive dielectric anisotropy liquid crystal; electrode layers formed on opposite surfaces of a predetermined area of the liquid crystal film for creating an electric field for switching the liquid crystal film in said predetermined area for viewing at normal incidence between a light transmissive state and a light scattering state in response to the presence or absence respectively of an applied electrical potential; and front and back transparent face plates which sandwich the liquid crystal film and electrode layers therebetween; light source disposed external of and adjacent to a light-receiving edge of the display panel means for illuminating the display panel means through said edge thereof; said light source comprising first and second optical lamps for illuminating the display panel means through said light receiving edge and an edge opposite to said light-receiving edge thereof respectively, and first and second light polarizing means disposed between the first and second optical lamps and said respective edges of the display panel means.
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8. A liquid crystal display device, comprising:
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liquid crystal display panel means including a polymer dispersed liquid crystal cell having positive dielectric anisotropy; light source disposed external of and adjacent to a light-receiving edge of the display panel means for illuminating the display panel means through said edge thereof; electrode means for creating an electric field for switching a predetermined area of the liquid crystal cell for viewing at normal incidence between a light transmissive state and a light scattering state in response to the presence or absence respectively of an electrical potential applied across the electrode means; the light source illuminating the display panel means substantially perpendicular to said electric field; and light polarizing means disposed between the light source and said light-receiving edge of the display panel means for only passing light therethrough which has a polarization perpendicular to the direction of the electrical potential applied by the electrode means. - View Dependent Claims (9)
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Specification