Video multiplexer

• US 4,517,593 A
• Filed: 04/29/1983
• Issued: 05/14/1985
• Est. Priority Date: 04/29/1983
• Status: Expired due to Fees

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Seal, Clinton D., Keller, Patrick N.
• Primary Examiner(s): Britton, Howard W.
• Assistant Examiner(s): Kostak, Victor R.
• Application Number:
  US06/489,987
• Time in Patent Office: 746 Days
• Field of Search: 358/93, 358/108, 358/109, 358/87, 358/183, 358/107, 358/103, 358/104, 358/105, 364/460, 434/4, 250/222.1, 273/351, 273/371, 356/3, 356/4, 356/7, 356/8, 356/9
• US Class Current: 348/139
• CPC Class Codes: F41J 5/10 Cinematographic hit-indicating systems cinematographic targets F41J9/14
• CPC Class Codes: H04N 5/2624 for obtaining an image which is composed of whole input images, e.g. splitscreen
• CPC Class Codes: H04N 7/181 for receiving images from a plurality of remote sources

Abstract

An event scoring apparatus using a video multiplexer and method are createdy using a plurality of video cameras to cover limited fields of view of a given area. The cameras are distributed to cover the area. The video output of the cameras is used as input to a video multiplex circuit which multiplexes the camera video signals to form a composite signal containing the desirable information from each camera and generated the sync signal for the slave camera. By counting horizontal lines of video and video sync levels, selected lines of video are combined to form a composite video image. The composite video image permits both a target and a strike event to be recorded in at least two locations within the composite video. A scoring systems inputs the multiplexer output to determine the miss distance and direction from the target. A programmable read only memory permits one of the camera video inputs to be a gray level which is inserted between consecutive camera lines of actual real time video signal. These gray level stripes provide ease in identifying which horizontal lines are producing a given effect.

Claims

1. A video multiplexer scoring system apparatus for scoring an event area comprising:

a plurality of cameras placed around the event area, such that it is viewed from at least two perpsectives, each of said cameras providing a standard video output including synchronization signals of a predetermined section of said event area;

means for synchronizing said plurality of camera'"'"'s video output to provide a pattern of horizontal stripes, where said means for synchronizing comprises;

a synchronization, sync, stripper circuit electrically connected to the video output of one of said plurality of cameras, said camera titled camera 1, said sync stripper circuit outputting vertical, horizontal, and composite synchronization signals;

a synchronization level shifter circuit connected to said sync stripper circuit output and to the remainder of said plurality of cameras such that said remainder of the plurality of cameras are synchronized, slaved, to camera 1;

a level shifter connected to said sync stripper output to increase the voltage range of the video output of camera 1, said level shifter outputting a vertical synchronization signal, a sample signal, and a horizontal synchronization signal;

a black clamp circuit connected to said sample signal output from said level shifter to ground the input signals of said video cameras;

a phase locked loop oscillator connected to the horizontal synchronization signal output of said level shifter, said phase locked loop oscillator synchronized to an integral multiple of the horizontal sync frequency of camera 1;

a first counter connected to said phase locked loop oscillator which cycles through said integral multple of the horizontal sync frequency of camera 1;

a second counter inputting said vertical and horizontal sync outputs of said level shifter to count the horizontal lines of said standard video signal and to reset said horizontal line counter after each vertical sync signal;

a programmable read only memory, PROM, connected to said second counter, said PROM programmed to select specific horizontal lines counted by said second counter and match those lines to a preselected pattern of said plurality of cameras;

a plurality of switches connected between said PROM and said plurality of cameras such that each switch is matched to a specific camera video input;

a flip-flop circuit connected between said first counter and said plurality of switches such that said switches are opened or closed for a preselected count in said first counter;

a composite video output circuit connected to said plurality of switches such that a given horizontal line of video signal is from only one of said plurality of cameras;

means for recording said composite video output connected to said composite video output circuit; and

means for scoring events that appear in said composite video output;

means for recording the occurrence of an event within said area by connecting said recording means to said synchronizing means, such that said pattern of horizontal stripes is recorded; and

means for locating said event within said area by triangulating said recorded synchronized horizontal stripes, said locating means connected to said recording means.

2. A video multiplexer scoring system apparatus for scoring an event area as described in claim 1 where said flip-flop circuit further comprises two AND gates connected to said first counter to match specific counts of said integral multiple of said horizontal sync with one of said flip-flops output signals.

3. A video multiplexer scoring system apparatus for scoring an event area as described in claim 1 where said means for synchronizing further comprises a split mode select circuit connected to said PROM to change the number of cameras video input used to create said composite video output.

4. A video multiplexer scoring system apparatus for scoring an event as described in claim 1 further comprising a fixed gray level signal as a video input from one of said plurality of cameras.

5. A video multiplexer scoring system apparatus for scoring an event area as described in claim 3 further comprising a fixed gray level signal as a video input from one of said plurality of cameras.

6. A video multiplexer scoring system apparatus for scoring an event areas as described in claim 1 where said PROM comprises an erasable PROM, EPROM.

7. A video multiplexer scoring system apparatus for scoring an event area as described in claim 1 where said plurality of switches further comprise:

a NOR gate between said PROM and camera 1 video input;

a plurality of AND gates, one each between said PROM and each video input from the rest of said plurality of cameras; and

an inverter between said NOR gate and said flip-flop circuit.

8. A video multiplexer scoring system apparatus for scoring an event area as described in claim 7 where said flip-flop circuit further comprises two AND gates connected to said first counter to match specific counts of said integral multiple of said horizontal sync with one of said flip-flops output signals.

9. A video multiplexer scoring system apparatus for scoring an event area as described in claim 8 where said means for synchronizing further comprises a split mode select circuit connected to said PROM to change the number of cameras video input used to create said composite video output.

10. A video multiplexer apparatus for scoring an event area as described in claim 9 further comprising a fixed gray level signal as a video input from one of said plurality of cameras.

11. A video multiplexer for combining a plurality of video inputs from a plurality of cameras as horizontal stripes comprising:

a synchronization, sync, stripper circuit electrically connected to the video output of one of said plurality of cameras, said camera titled camera 1, said sync stripper circuit outputting vertical, horizontal, and composite synchronization signals;

a synchronization level shifter circuit connected to said sync stripper circuit output and to the remainder of said plurality of cameras such that said remainder of the plurality of cameras are synchronized, slaved, to camera 1;

a level shifter connected to said sync stripper output to increase the voltage range of the video output of camera 1, said level shifter outputting a vertical synchronization signal, a sample signal, and a horizontal synchronization signal;

a black clamp circuit connected to said sample signal output from said level shifter to ground the input signals of said video cameras;

a phase locked loop oscillator connected to the horizontal synchronization signal output of said level shifter, said phase locked loop oscillator synchronized to an integral multiple of the horizontal sync frequency of camera 1;

a first counter connected to said phase locked loop oscillator which cycles through said integral multiple of the horizontal sync frequency of camera 1;

a second counter inputting said vertical and horizontal sync outputs of said level shifter to count the horizontal lines of said standard video signal and to reset said horizontal line counter after each vertical sync signal;

a programmable read only memory, PROM, connected to said second counter, said PROM programmed to select specific horizontal lines counted by said second counter and match those lines to a preselected pattern of said plurality of cameras;

a plurality of switches connected between said PROM and said plurality of cameras such that each switch is matched to a specific camera video input;

a flip-flop circuit connected between said first counter and said plurality of switches such that said switches are opened or closed for a preselected count in said first counter;

a composite video output circuit connected to said plurality of switches such that a given horizontal line of video signal is from only one of said plurality of cameras;

means for recording said composite video output connected to said composite video output circuit; and

means for scoring events that appear in said composite video output.