Sculptured transflector for dual mode active matrix liquid crystal display backlight

• US 6,039,451 A
• Filed: 06/04/1998
• Issued: 03/21/2000
• Est. Priority Date: 06/04/1998
• Status: Expired due to Term

• Current Assignee: Teledyne Scientific & Imaging, LLC (Teledyne Technologies Incorporated)
• Original Assignee: Rockwell Science Center, Inc.
• Inventors: Grave, Duane A.
• Primary Examiner(s): O'Shea, Sandra
• Assistant Examiner(s): DELGIZZI, RONALD ERNEST
• Application Number:
  US09/090,376
• Time in Patent Office: 656 Days
• Field of Search: 362/29, 362/30, 362/471, 362/561, 362/293, 362/236, 362/225, 362/33
• US Class Current: 362/29
• CPC Class Codes: B60Q 3/14 lighting through the surface to be illuminated
• CPC Class Codes: B60Q 3/18 for varying the light intensity
• CPC Class Codes: G01D 11/28 Structurally-combined illuminating devices
• CPC Class Codes: G02B 6/0021 for housing at least a part of the light source, e.g. by forming holes or recesses
• CPC Class Codes: G02B 6/0026 Wavelength selective element, sheet or layer, e.g. filter or grating
• CPC Class Codes: G02B 6/0068 Arrangements of plural sources, e.g. multi-colour light sources
• CPC Class Codes: G02F 1/133626 providing two modes of illumination, e.g. day-night

Abstract

Disclosed are a backlight and avionics display using the same to provide light to a liquid crystal display (LCD) device. In the backlight, a day mode light source positioned on a first side of the LCD device and adapted to provide a first source of light for use by the LCD device during day mode operations. A night mode light source positioned on the first side of the LCD device is adapted to provide a second source of light for use by the LCD device during night mode operations. A sculptured transflector positioned between the day mode light source and the night mode light source has, at a first side adjacent the day mode light source, a transflective material and a plurality of arcuate or parabolic surfaces in order to maximize a percentage of light from the day mode light source which is reflected toward the LCD device.

Claims

1. An avionics display for use in the cockpit of an aircraft, the display comprising:

a liquid crystal display device;

a day mode light source positioned on a first side of the liquid crystal display device and adapted to controllably provide a first source of light for use by the liquid crystal display device in displaying information during day mode operations;

a night mode light source positioned on the first side of the liquid crystal display device and adapted to controllably provide a second source of light for use by the liquid crystal display device in displaying information during night mode operations; and

a sculptured transflector positioned between the day mode light source and the night mode light source, a first side of the sculptured transflector adjacent the day mode light source having a transflective material thereon and forming a plurality of arcuate surfaces, wherein the transflective material and the plurality of arcuate surfaces are adapted to maximize a percentage of light from the day mode light source which is reflected toward the liquid crystal display device.

2. The avionics display device of claim 1, and further comprising a night vision imaging system (NVIS) filter positioned between the night mode light source and the day mode light source such that the NVIS filter filters the second source of light provided by the night mode light source during night mode operations, but does not filter the first source of light provided by the day mode light source during day mode operations.

3. The avionics display device of claim 2, wherein the NVIS filter absorbs substantially all light from the night mode light source having a wavelength of greater than about 630 nanometers.

4. The avionics display of claim 3, wherein the sculptured transflector absorbs at least about 90 percent of the second source of light from the night mode light source during night mode operations.

5. The avionics display device of claim 4, wherein the night mode light source is embedded within the sculptured transflector.

6. The avionics display device of claim 5, wherein the NVIS filter is embedded within the sculptured transflector.

7. The avionics display device of claim 6, wherein the NVIS filter includes a coating on the night mode light source.

8. The avionics display device of claim 4, wherein the night mode light source is positioned adjacent to a second side of the sculptured transflector.

9. The avionics display device of claim 8, wherein the NVIS filter includes a coating on the second side of the sculptured transflector.

10. An avionics display for use in the cockpit of an aircraft, the display comprising:

a liquid crystal display device;

a day mode light source positioned on a first side of the liquid crystal display device and adapted to controllably provide a first source of light for use by the liquid crystal display device in displaying information during day mode operations;

a night mode light source positioned on the first side of the liquid crystal display device and adapted to controllably provide a second source of light for use by the liquid crystal display device in displaying information during night mode operations;

a sculptured transflector positioned between the day mode light source and the night mode light source, a first side of the sculptured transflector adjacent the day mode light source having a transflective material thereon and forming a plurality of parabolic surfaces, wherein the transflective material and the plurality of parabolic surfaces are adapted to maximize a percentage of the first source of light from the day mode light source which is reflected toward the liquid crystal display device; and

a night vision imaging system (NVIS) filter positioned between the night mode light source and the day mode light source such that the NVIS filter absorbs substantially all portions of the second source of light provided by the night mode light source which have a wavelength of greater than about 630 nanometers, but does not absorb the first source of light provided by the day mode light source.

11. The avionics display of claim 10, wherein the sculptured transflector absorbs at least about 90 percent of the second source of light from the night mode light source during night mode operations.

12. The avionics display device of claim 10, wherein the night mode light source is embedded within the sculptured transflector.

13. The avionics display device of claim 12, wherein the NVIS filter is embedded within the sculptured transflector and includes a coating on the night mode light source.

14. The avionics display device of claim 10, wherein the night mode light source is positioned adjacent a second side of the sculptured transflector, and wherein the NVIS filter includes a coating on the second side of the sculptured transflector.

15. A backlight for backlighting a liquid crystal display, the backlight comprising:

a day mode light source adapted to controllably provide a first source of light for use by the liquid crystal display device in displaying information during day mode operations;

a night mode light source adapted to controllably provide a second source of light for use by the liquid crystal display device in displaying information during night mode operations;

a sculptured transflector positioned between the day mode light source and the night mode light source, a first side of the sculptured transflector adjacent the day mode light source having a transflective material thereon and forming a plurality of arcuate surfaces, wherein the transflective material and the plurality of arcuate surfaces are adapted to maximize a percentage of the first source of light from the day mode light source which will be reflected toward the liquid crystal display device; and

a night vision imaging system (NVIS) filter positioned between the night mode light source and the day mode light source such that the NVIS filter absorbs substantially all portions of the second source of light provided by the night mode light source which have a wavelength of greater than about 630 nanometers, but does not absorb the first source of light provided by the day mode light source.

16. The backlight of claim 15, wherein the sculptured transflector absorbs at least about 90 percent of the second source of light from the night mode light source during night mode operations.

17. The backlight of claim 15, wherein the night mode light source is embedded within the sculptured transflector.

18. The backlight of claim 17, wherein the NVIS filter is embedded within the sculptured transflector and includes a coating on the night mode light source.

19. The backlight of claim 15, wherein the night mode light source is positioned adjacent to a second side of the sculptured transflector, and wherein the NVIS filter includes a coating on the second side of the sculptured transflector.

20. The backlight of claim 15, wherein the sculptured transflector is formed from a polycarbonate material.