Electrical cable interface for electronic camera

• US 5,486,853 A
• Filed: 12/13/1994
• Issued: 01/23/1996
• Est. Priority Date: 12/13/1994
• Status: Expired due to Term

• Current Assignee: Polycom Incorporated (Plantronics, Inc.)
• Original Assignee: Picturetel Corporation (Plantronics, Inc.)
• Inventors: Coffey, John J., Baxter, Larry K.
• Primary Examiner(s): Groody, James J.
• Assistant Examiner(s): HSIA, SHERRIE Y
• Application Number:
  US08/355,036
• Time in Patent Office: 406 Days
• Field of Search: 348/222, 348/552, 348/722, 348/13, 348/12, 348/6, 348/4, 358/909.1
• US Class Current: 348/222.1
• CPC Class Codes: H04N 23/66 Remote control of cameras or camera parts, e.g. by remote control devices

Abstract

The invention features a video camera system where horizontal and vertical synchronizing signals and a pixel clock signal are generated and added to analog video signals from a video imaging device within an electronic camera head that is connected, via an electrical cable, to a remote host processor having digital signal processing circuitry for processing the video signals. The analog video signals generated by the video imaging device received by the host processor, over the electrical cable, are converted to digital video signals at the remote host, and are then processed by the digital signal processing circuitry.

Claims

1. A video camera system comprising:

an electronic camera head comprising;

a solid-state video imager for providing a video signal waveform comprising analog video signals, and

timing generating circuitry for generating horizontal and vertical synchronizing signals and a pixel clock signal;

a host video processor, located externally from the electronic camera head for receiving the analog video signals from the solid-state video imager and the horizontal and vertical synchronizing signals and the pixel clock signal from the timing generating circuitry, comprising;

an analog to digital converter for converting the analog video signals to digital video signals, and

digital signal processing circuitry for processing the digital video signals; and

an electrical cable for carrying the video signal waveform from the electronic camera head and the horizontal and vertical synchronizing signals and the pixel clock signal to the host video processor.

2. The video camera system of claim 1 wherein said camera head further comprises an adder circuit for adding the horizontal and vertical synchronizing signals to the video signal waveform to form a combined analog video signal waveform.

3. The video camera system of claim 2 wherein the adder circuit further adds the pixel clock signal to the combined analog video signal waveform.

4. The video camera system of claim 3 wherein the host video processor further comprises a filtering circuit for receiving and extracting the horizontal and vertical synchronizing signals from the combined analog video signal waveform.

5. The video camera system of claim 4 wherein the filtering circuit further extracts the pixel clock signal from the combined analog video signal waveform.

6. The video camera system of claim 1 wherein the electronic camera head further comprises a demodulator for receiving the analog video signals and generating demodulated video signals by extracting a reset pulse carrier signal from the analog video signals.

7. The video camera system of claim 3 wherein the electronic camera head further comprises a blanking circuit for blanking a portion of the video signal waveform;

and wherein the adder circuit adds the horizontal and vertical synchronizing signals and the pixel clock signal to the blanked portion.

8. The video camera system of claim 2 wherein the electronic camera head further comprises a gamma correction circuit for providing gamma correction to the analog video signals before conveying the analog video signals to the adder circuit.

9. The video camera system of claim 4 wherein the host video processor further comprises a synchronizing circuit for receiving the pixel clock signal from the filtering circuit to synchronize the host video processor with the analog video signals.

10. The video camera system of claim 1 wherein the host video processor further comprises a digital to analog converter for converting the digital video signals processed by the digital signal processing circuitry to analog video signals for transmission to a display monitor.

11. The video camera system of claim 1 wherein the host video processor further comprises video compression circuitry for compressing the digital video signals processed by the digital signal processing circuitry.

12. The video camera system of claim 11 wherein the video compression circuitry is merged with the digital signal processing circuitry.

13. The video camera system of claim 1 wherein the camera head further comprises a processor for receiving control information from the host video processor and adding said control information to the analog video signals.

14. The video camera system of claim 1 wherein the solid-state video imager is a color-stripe solid-state video imager.

15. The video camera system of claim 1 wherein the electrical cable comprises a shielded coaxial cable for transmitting the video signal waveform.

16. The video camera system of claim 1 wherein the electrical cable comprises a pair of wires for providing electrical power to the solid-state video imager.

17. The video camera system of claim 1 wherein the horizontal synchronizing signal, the vertical synchronizing signal and the pixel clock signal are transmitted over a single wire of the electrical cable.

18. The video camera system of claim 1 wherein the horizontal synchronizing signal, the vertical synchronizing signal and the pixel clock signal are each transmitted over individual wires of the electrical cable.

19. An electronic camera comprising:

a solid-state color-stripe video imager for providing analog video signals,

a demodulator for receiving the analog video signals and generating demodulated video signals by extracting a reset pulse signal from the analog video signals,

a timing signal generator for generating horizontal and vertical synchronizing signals and a pixel clock signal,

an adder circuit for generating an output video signal by adding the horizontal and vertical synchronizing signals, and the pixel clock signal, to the demodulated video signals and

an electrical cable having a pair of conductors for carrying the output video signal from the adder circuit to an external video processor.

20. The electronic camera of claim 19 further comprising a blanking circuit for blanking a portion of the analog video signals;

and

wherein the adder circuit adds the horizontal and vertical synchronizing signals and the pixel clock signal to the blanked portion.

21. The electronic camera of claim 19 further comprising a gamma correction circuit for receiving the analog video signals from the demodulator, and providing gamma correction to the analog video signals before conveying the analog video signals to the adder circuit.

22. The electronic camera of claim 19 further comprising a processor for receiving input signals from the external video processor, and providing the input signals to the adder circuit for adding to the demodulated video signals.

23. The electronic camera of claim 22, wherein the processor generates, in response to the input signals, control signals to focus a lens system positioned at a location in spaced juxtaposition to a front face of the solid-state color-stripe video imager.

24. A method of providing an interface, within an electronic camera, for generating analog video output signals from a solid-state video imager to an external video digital processor, comprising the steps of:

providing a video waveform comprising analog video signals from the solid-state video imager,

generating a horizontal synchronizing signal, a vertical synchronizing signal, and a pixel clock signal, and

conveying the analog video signals from the solid-state video imager and the horizontal synchronizing signal, the vertical synchronizing signal, and the pixel clock signal to the external video digital processor over a length of analog video signal carrying cable.

25. The method of claim 24 further comprising the step of:

generating within the electronic camera an output analog video signal by adding the horizontal synchronizing signal, the vertical synchronizing signal, and the pixel clock signal to the analog video signals.

26. The method of claim 25 further comprising the step of:

generating within the electronic camera demodulated analog video signals by extracting a carrier signal from the analog video signals.

27. The method of claim 26 further comprising the steps of:

blanking a portion of the demodulated analog video signals; and

adding the horizontal synchronizing signal and the vertical synchronizing signal to the blanked portion.

28. The method of claim 26 further comprising the step of gamma correcting the demodulated analog video signals.

29. The method of claim 26 further comprising the step of adding data information provided by the external video digital processor to the demodulated analog video signals.

30. The method of claim 24 further comprising the step of positioning, at a location in spaced juxtaposition to a front face of the solid-state video imager a lens system for focusing optical images on the front face of the solid-state video imager.

31. The method of claim 30 further comprising the step of controlling the distance between the lens system and solid-state video imager from a remote location.

32. The method of claim 27 further comprising the step of:

adding information control signals from said external video digital processor to said blanked portion.

33. The method of claim 32 further comprising the step of including camera control data in said information control signals.