Video termination detector with data receiver

• US 5,953,057 A
• Filed: 09/03/1996
• Issued: 09/14/1999
• Est. Priority Date: 09/03/1996
• Status: Expired due to Term

• Current Assignee: Sensormatic Electronics LLC (Johnson Controls International plc)
• Original Assignee: Sensormatic Electronics Corporation (Johnson Controls International plc)
• Inventors: Mills, Lawrence R., Thompson, Edwin S., Paolantonio, James R.
• Primary Examiner(s): Peng, John K.
• Assistant Examiner(s): Lo, Linus H.
• Application Number:
  US08/706,843
• Time in Patent Office: 1,106 Days
• Field of Search: 348/6, 348/8, 348/12, 348/9, 348/10, 348/192-193, 348/143, 348/180, 455/3.1, 455/5.1, 455/6.3, 455/8, 455/9, 455/67.1, 455/67.7, 455/226.1, 375/257, 333/4, 333/124, 333/17.3, 333/18, 324/512, 324/522, 324/5, 324/25, 324/526, 340/310.06, 340/649, 340/650, 340/651, 340/5.38, 340/652-653, 329/512, 329/525
• US Class Current: 348/192
• CPC Class Codes: H04N 17/00 Diagnosis, testing or measuring for television systems or their details

Abstract

An apparatus for detecting the properly terminated connection between video components transmitting a video signal from one video component to the other. The video and/or data signal is input to a resistance element. A first comparison input device is connected to the input side of the resistance element and a second comparison input device is connected to the output side of the resistance element. A comparison unit is provided for comparing the voltages from the first comparison input device and the second comparison input device to determine whether there is a voltage drop across the resistance element thereby determining whether the video component is properly terminated. A data processing element connected to the output of the comparison unit receives data from the comparison unit which is detected across the resistance element.

Claims

1. An apparatus for detecting a properly terminated connection between video components transmitting a video signal voltage from a transmitting video component to a receiving video component, comprising:

a) resistance means connected between the said two video components;

b) first comparison input means connected to the input side of said resistance means;

c) second comparison input means connected to the output side of said resistance means;

d) comparison means for comparing the voltages of the video signal from said first comparison input means and said second comparison input means to determine whether there is a voltage drop across said resistance means thereby indicating that the video components are properly terminated; and

e) switching means connected to said comparison means for switching to an alternate connection when there is improper termination between said transmitting video component and said receiving video component.

2. The apparatus of claim 1 wherein said transmitting video component comprises a camera and said receiving video component comprises a video monitor.

3. An apparatus for detecting a properly terminated connection between video components transmitting a video signal voltage from a transmitting video component to a receiving video component, comprising:

a) resistance means connected between the said two video components;

b) first comparison input means connected to the input side of said resistance means, said first comparison input means including a voltage divider to reduce the amplitude of the video signal;

c) second comparison input means connected to the output side of said resistance means; and

d) comparison means for comparing the voltages of the video signal from said first comparison input means and said second comparison input means, said comparison means comprising a comparator having a first and a second input and a single output and said first input being connected to said second comparison input means and said second input being connected to said first comparison input means to detect a voltage drop across said resistance means thereby indicating proper termination of the video components.

4. The apparatus of claim 3 further comprising an alarm means which is activated by said comparison means when said video components are not properly terminated.

5. The apparatus of claim 3 wherein said apparatus is located adjacent to the transmitting components.

6. The apparatus of claim 3 wherein said resistance means comprises a resistor.

7. The apparatus of claim 3 wherein said second comparison input means includes a capacitor to remove the DC component from the video signal and further includes a diode with its cathode connected to said capacitor and said positive input of said comparator and its anode connected to a positive voltage source which is less than the voltage source connected to the cathode of said capacitor of said first comparison input means to add a new DC component to provide an input threshold in said comparator.

8. An apparatus for detecting a properly terminated connection between video components transmitting a video signal voltage from a transmitting video component to a receiving video component, comprising:

a) resistance means connected between the said two video components;

b) first comparison input means connected to the input side of said resistance means, said first comparison input means including a control means to control the DC component in the video signal;

c) second comparison input means connected to the output side of said resistance means; and

d) comparison means for comparing the voltages of the video signal from said first comparison input means and said second comparison input means, said comparison means comprising a comparator having a first and a second input and a single output and said first input being connected to said second comparison input means and said second input being connected to said first comparison input means to detect a voltage drop across said resistance means thereby indicating proper termination of the video components.

9. The apparatus of claim 8 wherein said control means comprises a capacitor to remove the DC component from the video signal and further includes a diode with its cathode connected to said capacitor and said negative input of said comparator and its anode connected to a positive voltage source to add a new DC component.

10. An apparatus for detecting a properly terminated connection between video components transmitting a video signal voltage from a transmitting video component to a receiving video component, comprising:

a) resistance means connected between the said two video components;

b) first comparison input means connected to the input side of said resistance means;

c) second comparison input means connected to the output side of said resistance means;

d) comparison means for comparing the voltages of the video signal from said first comparison input means and said second comparison input means to determine whether there is a voltage drop across said resistance means thereby indicating that the video components are Properly terminated; and

data processing means connected to said comparison means to receive control data for controlling the functions of said transmitting video component.

11. The apparatus of claim 10 further comprising a data detection means connected to said comparison means for detecting control data sent from the receiving video component end of the connection between said transmitting and receiving video components.

12. The apparatus of claim 10 further comprising a data processing element connected to the output of said comparison means to receive control data for controlling the functions of said video component.

13. The apparatus of claim 10 wherein the control data is present with the video signal but transmitted in the opposite direction and detected across said resistance means.

14. The apparatus of claim 10 further comprising a synchronizing pulse separator to provide a timing reference to said data processing means for receiving control data only during predetermined periods when control data is intended to be received.

15. The apparatus of claim 13 wherein the data comprises camera control data.

16. A method for detecting a Properly terminated connection between video components transmitting a video signal voltage from a transmitting video component to a receiving video component, comprising the steps of:

applying the video signal to a resistance means connected between the said two video components;

comparing the video signal voltage from a first comparison input means connected to the input side of the resistance means and the voltage from a second comparison input means connected to the output side of the resistance means to determine whether there is a voltage drop across the resistance means thereby indicating that the video components are properly terminated; and

switching to an alternate connection when there is improper termination between the transmitting video component and the receiving video component.

17. A method for detecting a properly terminated connection between video components transmitting a video signal voltage from a transmitting video component to a receiving video component, comprising the steps of:

applying the video signal to a resistance means connected between the said video components;

reducing the amplitude of the video signal in a first comparison input means using a voltage divider, said first comparison input means being connected to the input side of the resistance means; and

comparing the video signal voltage from the first comparison input means as reduced in said reducing step and the voltage from a second comparison input means connected to the output side of the resistance means to determine whether there is a voltage drop across the resistance means thereby indicating that the video components are Properly terminated.

18. The method of claim 17 further comprising the step of activating an alarm means using the comparison means when the video components are not properly terminated.

19. The method of claim 17 wherein the step of comparing is performed adjacent to the transmitting video component.

20. The method of claim 17 wherein the resistance means comprises a resistor.

21. The method of claim 17 wherein the step of comparing the video signal voltages comprises the step of detecting a voltage drop across the resistance using a comparator having a positive input connected the second comparison input means and a negative input connected to the first comparison input means thereby indicating proper termination of the video components.

22. The method of claim 17 further comprising the step of controlling the DC component in the video signal.

23. The method of claim 22 wherein the step of controlling the DC component includes the step removing the DC component from the video signal in the first comparison input means using a capacitor and the step of providing a new DC component in the first comparison input means using a diode with its cathode connected to said capacitor and the negative input of the comparator and its anode connected to a positive voltage source.

24. The method of claim 21 further comprising the step of removing the DC component from the video signal in the second comparison input means using a capacitor and the step of providing a new DC component in the second comparison input means using a diode with its cathode connected to the capacitor and the positive input of the comparator and its anode connected to a positive voltage source which is less than the voltage source connected to the cathode of said capacitor of the first comparison input means providing an input threshold.

25. A method for detecting a Properly terminated connected between video components transmitting a video signal voltage from a transmitting video component to a receiving video component, comprising the steps of:

applying the video signal to a resistance means connected between the said two video components;

comparing the video signal voltage from a first comparison input means connected to the input side of the resistance means and the voltage from a second comparison input means connected to the output side of the resistance means to determine whether there is a voltage drop across the resistance means thereby indicating that the video components are properly terminated; and

receiving control data for controlling the functions of the transmitting video component.

26. The method of claim 25 further comprising the step of detecting control data sent from the receiving end of the connection between said transmitting and receiving video components using a data detection means located at the transmitting end of the connection between said transmitting and receiving video components.

27. The method of claim 25 further comprising the step of receiving control data for controlling the functions of the transmitting video component using a data processing means connected to the comparison means.

28. The method of claim 27 wherein the control data is present with the video signal but transmitted in the opposite direction and detected across the resistance means.

29. The method of claim 27 further comprising the step of the providing a timing reference to the data processing means for receiving control data only during predetermined periods when control data is intended to be received.

30. The method of claim 25 wherein the data comprises camera control data.