Patent Application
20090015998
1. Field of the Invention.
The invention relates generally to a modular display panel for enclosing Commercial-Off-The-Shelf (“COTS”) display technologies. More particularly, the invention relates to a modular display panel for housing COTS light emitting or transmitting display subassemblies such as Liquid Crystal Displays (LCD) for military and other severe environments.
2. Description of Related Art.
Commercial-Off-The-Shelf (“COTS”) light emitting or transmitting display subassemblies are often fragile and susceptible to damage during movement or exposure to any sort of unstable environment. While COTS light emitting or transmitting display subassemblies may be acceptable in non-severe environments such as in a personal home, or at an office, they may be unacceptable in other areas. For example, in the military, the equipment used must be able to withstand exposure to a variety of severe environments such as forceful impacts, debris filled air, electromagnetic radiation, etc.
However, to produce a COTS light emitting or transmitting display subassembly that can withstand exposure to a variety of harmful environments is often expensive. The usual options for the military are to produce the entire COTS light emitting or transmitting display subassembly themselves, which is undesirable due to the need for machinery and expertise in the display production, or to custom order a COTS light emitting or transmitting display subassembly, which is undesirable due to the costs required in redesigning the COTS light emitting or transmitting display subassembly. Thus, there is a need for an invention to allow COTS light emitting or transmitting display subassembly to operate in severe environments at a reasonable cost.
The present invention is a modular display assembly for housing a COTS light emitting or transmitting display subassembly such as a Liquid Crystal Displays (“LCD”). The modular display assembly has a base plate, a first frame with a first opening, the first frame attached to the base plate to form a cavity, and a window attached to the first frame at the first opening for enclosing the cavity. A second frame with a second opening is located in the cavity. A circuit is located within the cavity adjacent the base plate. A plurality of light emitting diodes are mounted on the circuit board on the side facing the display sub assembly which is connected to the second frame.
The first frame is preferably made from a metal coated glass filled plastic making it electrically and thermally conductive, and relatively impact resistant. The base plate is also preferably electrically and thermally conductive, and relatively impact resistant. The window is preferably made of a glass layer, a conductive indium tin oxide layer, or may be made of materials such as those disclosed in Saxena et al. (U.S. Pat. No. 7,167,309), which is incorporated by reference as if fully set forth herein. The window is preferably electrically and thermally conductive, and could also be relatively impact resistant.
With the first frame, the window, and the base plate being electrically conductive, a Faraday cage is found around the COTS light emitting or transmitting display subassembly. The Faraday cage protects the COTS light emitting or transmitting display subassembly from electromagnetic or other types of interference and the display assembly from emitting electromagnetic or other types of interference.
The exact nature of this invention, as well as the objects and advantages thereof, will become readily apparent from consideration of the following specification in conjunction with the accompanying drawings in which like reference numerals designate like parts throughout the figures thereof and wherein:
A COTS light emitting or transmitting display subassembly 6 such as a liquid crystal display can be attached to the second frame 4. As can be seen, the first frame 2 is attached to the base plate 16 to form a cavity 28. A window 14 is attached to the first frame 2 at the first opening for enclosing the cavity 28.
The first frame 2 may be made of metal, glass, plastic, or a combination thereof, such as a metal coated glass filled plastic. The first frame 2 is preferably electrically and thermally conductive, and relatively impact resistant. The base plate 16 is also electrically and thermally conductive, and be relatively impact resistant. The window 14 is preferably made of glass layer 10. The window 14 could also have a conductive indium tin oxide layer (not shown). The window 14 could be made of other materials, such as those disclosed in Saxena et al. (U.S. Pat. No. 7,167,309). The window 14 is preferably electrically and thermally conductive, and also relatively impact resistant. Adjacent the window 14 is an indium tin oxide layer heater and electromagnetic interference (EMI) shield 22.
Because the first frame 2, the window 14, and the base plate 16 are electrically conductive, they could form a Faraday cage around the COTS light emitting or transmitting display subassembly 6. This protects the COTS light emitting or transmitting display subassembly 6 from electromagnetic or other types of interference and the display assembly from emitting electromagnetic or other types of interference. Because the first frame 2, the base plate 16, the window 14 are relatively impact resistant, the structure will prevent damage to the COTS light emitting or transmitting display subassembly 6. Furthermore, the first frame 2, the window 14, and the base plate 16 are preferably sealed to protect the COTS light emitting or transmitting display subassembly 6 from humidity, salt fog, and harmful particles such as sand, rocks, debris, or dust.
Diffusers and/or film 26 could be located between the COTS light emitting or transmitting display subassembly 6 and the light emitting diodes 18. The present invention contemplates that drive electronics 12 for driving the COTS light emitting or transmitting display subassembly 6 is located in the cavity adjacent any one of the sides of the circuit board 8 adjacent to the base plate 6.
The base plate 16 works in conjunction with the first frame 2 and the window 14 to maintain the drive electronics 12, circuit board 8, light emitting diodes 18, diffusers and/or film 26, the COTS light emitting or transmitting display subassembly 6, second frame 12 relatively immobile during shock and vibration.
The second frame 4 is adjacent to the drive electronics 12. The second frame 4 works in conjunction with the first frame 2 and window 14 to maintain the drive electronics 12, circuit board 8, light emitting diodes 18, diffusers and/or film 26, and the COTS light emitting or transmitting display subassembly 6 in a relatively immobile state during shock and vibration.
The second frame 4 works in conjunction with first frame 2 and the base plate 16 to maintain the drive electronics 12, circuit board 8, light emitting diodes 18, diffusers and/or film 26, the COTS light emitting or transmitting display subassembly 6 in a relatively immobile state during shock and vibration.
The present invention prevents the COTS light emitting or transmitting display subassembly 6 from being damaged by reducing the likelihood that the components contained within the modular display assembly 30, such as drive electronics 12, circuit board 8, light emitting diodes 18, diffusers and/or film 26, the COTS light emitting or transmitting display subassembly 6 will move around in the cavity 28.
The modular display assembly is mounted, for example, on a customer bulkhead 24, such as on an airplane, a helicopter, a tank, a car, a boat, a bunker, for example.
The modular display assembly 30 preferably also has a bezel and controls 20 to allow a user to control the COTS light emitting or transmitting display subassembly 6, such as brightness and contrast. There could also be an optional connector and electromagnetic interference filter 40 connected to the base plate 16 and the circuit board 8.
In each of the 4 hours of testing for each axis, one hour was spent meeting the MIL-STD-810 vibration requirements of the H-1 Cobra Helicopter, including Gunfire Vibration 32, one hour was spent meeting the Endurance Vibration requirements of the E-2D Hawkeye carrier bound aircraft 34, one hour was spent meeting the Functional Vibration requirements of the E-2D Hawkeye carrier bound aircraft 36, and one hour was spent meeting the Endurance Vibration requirements of the MH-60 Helicopter 38.
As can be seen in
Furthermore, the two samples of the modular display assembly 30 were also subjected to 20 Functional Shocks and 40 Crash Safety Shocks. There were no anomalies or performance issues such as flicker in the present invention during these tests.
