Laser backlighting for displays
View Patent ↗Displays such as LCD panels are illuminated using frequency-doubled vertical extended cavity surface emitting lasers (VECSELs) as efficient light sources. Visible light from the VECSELs are directed to an illuminating panel using optical fibers and/or optical gratings to provide substantially uniform illumination of the illuminating panel. Visible light from the illuminating panel, which can be provided at a particular number of primary wavelengths by the VECSELs, is then used to illuminate the display.
1. A display apparatus, the display apparatus comprising:
a liquid crystal display (LCD) panel on which is formed an image to be viewed by a user when looking directly at the LCD panel; and,
a backlight for providing backlighting to the LCD panel at an intensity that allows the image formed on the LCD panel to be viewed by the user when looking directly at the LCD panel, the backlight including:
a plurality of frequency-doubled vertical extended cavity surface emitting lasers that generate visible light, and
an optical coupling arrangement configured to spread the visible light so as facilitate substantially uniform backlight illumination for the LCD panel.
2. The display apparatus of claim 1 , wherein the visible light is generated to include three primary wavelengths.
3. The display apparatus of claim 2 , wherein the optical coupling arrangement comprises an optical diffuser.
4. The display apparatus of claim 3 , wherein the optical diffuser comprises at least one of an optical grating, a cylindrical lens, or a Fresnel lens.
5. The display apparatus of claim 2 , wherein the optical coupling arrangement comprises a plurality of optical fibers.
6. The display apparatus of claim 5 , wherein the optical coupling arrangement further comprises an optical diffuser.
7. The display apparatus of claim 6 , wherein the optical diffuser comprises at least one of an optical grating, a cylindrical lens, or a Fresnel lens.
8. The display apparatus of claim 6 , wherein the optical diffuser is provided along a side of the LCD panel.
9. The display apparatus of claim 5 , wherein the optical coupling arrangement further comprises a plurality of optical diffusers.
10. The display apparatus of claim 9 , wherein the plurality of optical diffusers are provided along a plurality of sides of the LCD panel.
11. The display apparatus of claim 5 , wherein the optical coupling arrangement further comprises an optical diffuser located at a corner of the LCD panel.
12. The display apparatus of claim 1 , wherein each primary wavelength of the visible light is generated by a subset of at least two of the plurality of frequency-doubled vertical extended cavity surface emitting lasers.
13. The display apparatus of claim 1 , wherein the visible light is generated at more than three primary wavelengths.
14. The display apparatus of claim 1 , wherein the visible light is emitted through a single aperture.
15. A backlight device comprising:
a plurality of frequency-doubled vertical extended cavity surface emitting lasers that generate visible light; and
an optical coupling arrangement configured to spread the visible light so as facilitate substantially uniform backlight illumination for a display panel;
wherein the backlight illumination is provided at an intensity that allows an image formed on the display panel to be viewed by a user when looking directly at the display panel.
16. A backlight device as in claim 15 wherein the display panel is a transmissive display panel.
17. A backlight device as in claim 15 wherein the display panel is a reflective display panel.
18. A method for providing backlighting to a display panel, the method comprising:
generating visible light using a plurality of frequency-doubled vertical extended cavity surface emitting lasers, the visible light being generated at an intensity that allows an image formed on the display panel to be viewed by a user when looking directly at the display panel;
spreading the visible light so as to provide substantially uniform backlight illumination to the display panel.
19. The method of claim 18 , wherein the display panel is an LCD panel.
20. A display apparatus, the display apparatus comprising:
a liquid crystal display (LCD) panel on which is formed an image to be viewed by a user when looking directly at the LCD panel; and,
a backlight for providing backlighting to the LCD panel at an intensity that allows the image formed on the LCD panel to be viewed by the user when looking directly at the LCD panel, the backlight including:
a plurality of frequency-doubled vertical extended cavity surface emitting lasers that generate visible light, and
an optical coupling arrangement configured to distribute the visible light to provide the backlighting to the LCD panel, wherein the optical coupling arrangement further comprises an optical diffuser, the optical diffuser including at least one of notches in the optical fibers, abraded surfaces of the optical fibers, or spatially-separated distal ends of the optical fibers.