Rugged shock-resistant backplane for embedded systems

• US 7,079,778 B1
• Filed: 04/07/2000
• Issued: 07/18/2006
• Est. Priority Date: 04/07/2000
• Status: Expired due to Fees

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: Northrop Grumman Corporation
• Inventors: Hischke, Mark D., Nelson, Shannon Mary, Paul, Richard Joseph
• Primary Examiner(s): SEDIGHIAN, REZA
• Application Number:
  US09/544,762
• Time in Patent Office: 2,293 Days
• Field of Search: 359/152, 359/154, 359/159, 359/163, 359/172, 398/135, 398/138, 398/160, 398/164, 398/128, 398/130, 398/140
• US Class Current: 398/164
• CPC Class Codes: H04B 10/802 for isolation, e.g. using optocouplers
• CPC Class Codes: H04B 10/803 Free space interconnects, e.g. between circuit boards or chips
• CPC Class Codes: H05K 1/02 Details
• CPC Class Codes: H05K 1/14 Structural association of two or more printed circuits providing electric connection to or between printed circuits H05K1/11, H01R12/00

Abstract

Infrared communications scheme for use in an embedded system. According to a preferred embodiment, the invention comprises the use of an infrared communications scheme, according to IrDA protocol, which is utilized to transmit and receive data optically between circuit cards housed within an enclosed, embedded system. Preferably, each respective circuit card is provided with an LED and photodiode to respectively transmit and receive data optically. As such, wire connections are eliminated and allows the systems and methods of the present invention to withstand a greater degree of vibration and shock than that of the prior-art systems and methods. Moreover, the systems and methods of the present invention provide increased reliability and provide greater electrical isolation between modules than prior-art systems and methods.

Claims

1. A shock-resistant system for operatively interconnecting circuit cards within a computer system to enable data to be transmitted and received therebetween comprising:

a) a common backplane having a plurality of circuit card connectors disposed in spaced apart relation thereon for supporting circuit cards in a generally upright parallel relationship;

b) a plurality of circuit cards, each of said circuit cards being mounted to one of said circuit card connectors, each of said circuit cards having a transmitter LED and a receiver photodiode formed thereon;

c) a plurality of optical pathways formed solely through air between said circuit cards, the optical pathways forming a plurality of independent optical connections between said transmitter LED on at least one of said circuit cards and said receiver photodiodes on any two of said circuit cards; and

d) wherein said circuit cards are maintained in fixed relationship to one another via said common backplane to maintain continuous optical intercard communications between each of said circuit cards such that the LED on each circuit card is operative to generate and transmit a signal, and the photodiode of one corresponding circuit card is operative to receive the signal through the corresponding optical pathway.

2. The system of claim 1 wherein said signals generated by said transmitter LEDs and received by said photodiodes comprise optically transmitted infrared radiation.

3. The system of claim 2 wherein said transmission and reception of signals between said transmitter LEDs and said receiver photodiodes comprise a standardized infrared communications scheme protocol.

4. The system of claim 3 wherein said infrared communications scheme protocol comprises a protocol developed by the Infrared Data Association.

5. The system of claim 1 wherein said circuit cards are housed within an enclosure.

6. The system of claim 1 wherein said circuit cards are operative to run an embedded application.

7. A method for operatively interconnecting circuit cards within a computer to enable data to be transmitted and received therebetween comprising:

a) forming a common backplane having a plurality of circuit card connectors disposed in spaced apart relation thereon for supporting circuit cards in a generally parallel upright relationship;

b) providing a plurality of circuit cards each having a transmitter LED diode and a receiver photodiode formed thereon;

c) mounting each of said circuit cards to one corresponding circuit card connector to establish a plurality of optical pathways between the LED diodes and the photodiodes of the corresponding circuit cards, such that a plurality of independent optical connections between the circuit cards are formed solely through air;

d) generating and transmitting a light from at least one of the LED diode, the light generated from the LED carrying data to be transmitted from the circuit card on which the at least one LED diode is formed;

e) receiving the light by the photodiodes formed on any two of the circuit cards, so as to receive the data carried by the light.

8. The method of claim 7 wherein in steps d) and e), said light generated by said LED and received by said photodiode comprise optically transmitted infrared radiation.

9. The method of claim 7 wherein in the light transmitted from said LED to said photodiode comprise a standardized infrared communications scheme protocol.

10. The method of claim 9 wherein said infrared communications scheme protocol comprises a protocol developed by the Infrared Data Association.

11. The method of claim 9 wherein said circuit cards are operative to run an embedded application.

12. The method of claim 7 wherein said circuit cards are operative to run an embedded application.

13. A shock-resistant system for operatively interconnecting circuit cards within a computer system to enable data to be transmitted and received therebetween comprising:

a) a common backplane having a plurality of circuit card connectors disposed in spaced apart relation thereon for supporting circuit cards extending normal to the backplane in a generally upright parallel relationship;

b) at least first, second, and third circuit cards, pairs of first, second and third LEDs and photodiodes formed thereon, respectively, the first, second and third LED being operative to generate and transmit infrared signals which carry data to be transmitted from the first, second and third circuit cards, respectively, and the first, second and third photodiodes being operative to receive the infrared signal generated by the first, second and third LEDs;

c) first and second optical pathways formed between the first LED with the second and third photodiodes, third and fourth optical pathways formed between the second LED with the first and third photodiodes, and fifth and sixth optical pathways formed between the third LED and the first and second photodiodes; and

d) wherein the first, second and third circuit cards are maintained in fixed relationship to one another, and the infrared signals are transmitted along the first, second, third, fourth, fifth and sixth optical pathways independently with each other.

14. The system of claim 13, wherein the computer system includes a digital camera or a hand-held data collection device.

15. The system of claim 13, wherein the infrared signal comprises a standardized infrared communication scheme protocol.