Channelized plate
View Patent ↗Preferred embodiments utilize a plurality of optical channels to effectively aim the light emitted by a liquid crystal display (LCD). Embodiments may also change the nominal and range of viewing angles of light in two or three dimensions in order to confine the emitted light towards the intended observer.
1. An LCD comprising:
a backlight producing light in a plurality of angles;
a fiberoptic plate in front of said backlight adapted to permit only light within a selected range of angles to pass through the plate;
a light-turning element between said backlight and said fiberoptic plate which directs light only towards the selected range of angles;
a first linear polarizer in front of said fiberoptic plate;
a liquid crystal layer in front of said first linear polarizer;
a lens element placed between the fiberoptic plate and the liquid crystal layer; and
a second linear polarizer in front of said liquid crystal layer.
2. An LCD comprising:
a backlight producing light in a plurality of angles;
a channelized plate in front of said backlight adapted to permit only light within a selected range of angles pass through the plate;
a first linear polarizer in front of said channelized plate;
a lensing element between said channelized plate and said first linear polarizer;
a liquid crystal layer in front of said first linear polarizer; and
a second linear polarizer in front of said liquid crystal layer.
3. The LCD from claim 2 further comprising a diffuser element between said lensing element and said first linear polarizer.
4. The LCD from claim 3 further comprising an anti-reflective element in front of said second linear polarizer.
5. A method for filtering light from a LCD towards an intended observer, the LCD comprising a backlight placed behind a liquid crystal layer, the method comprising the steps of:
placing a channelized optical plate between the backlight and the liquid crystal layer, the channelized plate comprising a plurality of optical fibers oriented in the X-Y plane towards an intended observer of the LCD, where a desired range of angles of light within the X-Y plane has been selected;
accepting light from the backlight where the light rays travel at a plurality of angles in the X-Y plane relative to the axis of the fibers;
allowing light rays within the selected range of angles in the X-Y plane to pass through the fibers; and
absorbing light rays which are outside of the selected range of angles in the X-Y plane.
6. The method of filtering light from an LCD from claim 5 wherein
said channelized plate comprises optical fibers which are further oriented in the X-Z plane towards an intended observer of the LCD and where a desired range of angles of light within the X-Z plane has been selected;
and further comprising the steps of:
accepting light from the backlight where the light rays travel at a plurality of angles in the X-Z plane relative to the axis of the fibers;
allowing light rays within the selected range of angles in the X-Z plane to pass through the fibers; and
absorbing light rays which are outside of the selected range of angles in the X-Z plane.
7. A liquid crystal display assembly comprising:
a liquid crystal layer;
a backlight placed behind the liquid crystal layer; and
a channelized optical plate between the backlight and the liquid crystal layer, the plate having a plurality of axially parallel optical fibers which terminate at one end in an entrance surface and at the other end in an exit surface, wherein said fibers are adapted to
accept light through the entrance surface in a plurality of x-y angles which are defined as the angle between the axis of the fiber and the light ray within the x-y plane, and where a critical x-y angle is defined as the largest x-y angle where the corresponding light ray can substantially pass through said fiber without being absorbed;
emit light through the exit surface if the x-y angle is less than the critical x-y angle; and
substantially absorb light if the x-y angle is greater than the critical x-y angle.
8. The liquid crystal display assembly of claim 7 wherein:
the axis of the fibers are generally non-normal to the entrance surface within the x-y plane.
9. The liquid crystal display assembly of claim 7 further comprising:
light absorbing material disposed between said fibers.
10. The liquid crystal display assembly of claim 7 wherein:
said critical x-y angle is 15 degrees or less.
11. The liquid crystal display assembly of claim 7 wherein:
the distance between the entrance and exit surfaces causes light rays which enter at x-y angles greater than the critical x-y angle to reflect at least once off the fiber.
12. The liquid crystal display assembly of claim 8 wherein:
said entrance surface and exit surface are substantially flat and substantially parallel.
13. The liquid crystal display assembly of claim 8 wherein:
said exit surface has a curved profile.
14. The liquid crystal display assembly of claim 8 wherein:
said exit and entrance surfaces have curved profiles.
15. The liquid crystal display assembly of claim 8 wherein:
the axis of said fibers are directed towards an intended observer.
16. The liquid crystal display assembly of claim 7 wherein:
the axis of said fibers are generally non-normal to the entrance surface within the x-z plane; and
said fibers are further adapted to:
accept light through the entrance surface in a plurality of x-z angles which are defined as the angle between the axis of the fiber and the light ray within the x-z plane, and where a critical x-z angle is defined as the largest x-z angle where the corresponding light ray can substantially pass through said fiber without being absorbed;
emit light through the exit surface if the x-z angle is less than the critical x-z angle; and
substantially absorb light if the x-z angle is greater than the critical x-z angle.
17. The liquid crystal display assembly of claim 16 further comprising:
light absorbing material disposed between said fibers.
18. The liquid crystal display assembly of claim 16 wherein:
said critical x-z angle is 15 degrees or less.
19. An LCD comprising:
a backlight producing light in a plurality of angles;
a channelized plate in front of said backlight and containing optical fibers which permit light within a selected range of angles to pass through the plate while substantially absorbing light which is outside the selected range of angles;
a light diffusing layer placed between the backlight and the channelized plate;
a liquid crystal layer in front of the channelized plate; and
a lens element placed between the channelized plate and the liquid crystal layer.
20. The LCD of claim 19 further comprising:
a light turning element placed between the light diffusing layer and the channelized plate.
21. The LCD of claim 19 wherein:
the lens element is a Fresnel lens.