Remote imager video camera cable compensation circuitry

• US 5,696,553 A
• Filed: 02/23/1995
• Issued: 12/09/1997
• Est. Priority Date: 09/25/1992
• Status: Expired due to Term

• Current Assignee: Linvatec Corporation (Jefferies Financial Group, Inc.)
• Original Assignee: Bristol-Myers Squibb Company
• Inventors: Christoff, Jordan C., D'Alfonso, David A.
• Primary Examiner(s): Faile, Andrew
• Assistant Examiner(s): Ho, Tuan V.
• Application Number:
  US08/393,284
• Time in Patent Office: 1,020 Days
• Field of Search: 348/207, 348/211, 348/213, 348/222, 348/45, 348/61, 348/505, 348/500, 348/294, 348/311, 348/312, 348/241
• US Class Current: 348/211.14
• CPC Class Codes: H04N 23/555 for picking-up images in sites, inaccessible due to their dimensions or hazardous conditions, e.g. endoscopes or borescopes
• CPC Class Codes: H04N 23/66 Remote control of cameras or camera parts, e.g. by remote control devices

Abstract

A video camera of the type in which the camera head is detached from the camera control unit, and coupled to the same with a cable is provided. The driving circuitry for the imager is situated at the camera head. Compensation circuitry is included to adjust the phase relationship between the timing signals passed to and from the camera control unit over the cable to at least partly compensate for delay through the cable.

Claims

1. A video camera, comprising:

a camera control unit for providing a first timing signal;

a camera head positioned remotely from the camera control unit and coupled thereto by a cable, the camera head including an imager for providing, responsive to at least one driving signal, a composite signal, the composite signal comprising a second timing signal and an image signal, the first and second timing signals having a phase relationship;

driving circuitry situated within the camera head for providing the at least one driving signal responsive to the first timing signal;

the cable including at least one signal line for conveying the first timing signal from the camera control unit to the driving circuitry within the camera head, and the composite signal to the camera control unit; and

compensation circuitry coupled to or included within the camera control unit, and also coupled to the imager, for adjusting throughout a time period having a duration the phase relationship between the first timing signal and the second timing signal by a pre-determined value to at least partly compensate for delay through the cable, wherein the pre-determined value is kept fixed for the duration of the time period.

2. The camera of claim 1 wherein the compensation circuitry includes a storage device for storing the pre-determined value throughout the time period.

3. The camera of claim 2 wherein the compensation circuitry is adapted to use the pre-determined value throughout a remainder of a surgical procedure.

4. The video camera of claim 1, further comprising an endoscope attached to the camera head.

5. A video camera, comprising:

a camera control unit for providing a first timing signal;

a camera head positioned remotely from the camera control unit and coupled thereto by a cable, the camera head including an imager for providing, responsive to at least one driving signal, a composite signal, the composite signal comprising a second timing signal and an image signal, the first and second timing signals having a phase relationship;

driving circuitry situated within the camera head for providing the at least one driving signal responsive to the first timing signal;

the cable including at least one signal line for conveying the first timing signal from the camera control unit to the driving circuitry within the camera head, and the composite signal to the camera control unit; and

compensation circuitry coupled to or included within the camera control unit, and also coupled to the imager, for adjusting the phase relationship between the first timing signal and the second timing signal by a value to at least partly compensate for delay through the cable, wherein the compensation circuitry comprises a microprocessor for determining the value, a storage device coupled to or included within the microprocessor for storing the value, and a programmable delay device coupled to the microprocessor and responsive to the value for adjusting the phase relationship.

6. The camera of claim 5 wherein the compensation circuitry further comprises a timing pulse separator for separating the second timing signal from the composite signal, and a phase detector for determining the phase relationship between the first timing signal and the second timing signal, and the microprocessor in conjunction with the programmable delay device are configured to iteratively determine the value while monitoring the phase relationship determined by the phase detector.

7. A method for at least partly compensating for delay through a cable in a video camera including a camera control unit and a camera head positioned remotely from the camera control unit and coupled thereto by the cable, the method comprising the steps of:

generating a first timing signal in the camera control unit;

generating in the camera head, responsive to the first timing signal, a composite signal, comprising an image signal and a second timing signal, the first and second timing signals having a phase relationship;

passing the composite signal through the cable to the camera control unit;

determining during a first time period a value;

storing the value throughout a second time period different from the first time period, the second time period having a duration, such that the value is fixed for the duration of the second time period; and

adjusting, throughout the second time, the phase relationship between the first timing signal and the second timing signal by the value to at least partly compensate for delay through the cable.

8. The method of claim 7 further comprising iteratively determining the value while monitoring the phase relationship between the first and second timing signals.

9. The method of claim 7 further comprising selecting the first time period to be when the second timing signal is of high quality.

10. The method of claim 7 further comprising selecting the first time period to be at the beginning of a surgical procedure.

11. The method of claim 10 further comprising selecting the second time period to be during the remainder of the surgical procedure.

12. The method of claim 7 further comprising determining the value responsive to the phase relationship.

13. A camera control unit adapted for use with a solid state imager which is remotely coupled to the control unit by a cable and is also coupled to driving circuitry, wherein the driving circuitry receives a first timing signal generated in the control unit, and provides at least one driving signal to said imager, and said imager provides, responsive to said at least one driving signal, to said control unit, a composite signal including an image signal and a second timing signal, the first and second timing signals having a phase relationships the camera control unit comprising:

control circuitry for providing the first timing signal; and

compensation circuitry, coupled to the control circuitry and adapted to be coupled to the solid state imager, for adjusting the phase relationship between the first timing signal and the second timing signal by a value to at least partly compensate for delay through the cable, the compensation circuitry comprising;

a processor for determining the value; and

a device coupled to the processor and responsive to the value for adjusting the phase relationship.

14. The camera control unit of claim 13 wherein the processor is configured to determine the value at a time when the second timing signal is known to be of high quality.

15. The camera control unit of claim 14 wherein the processor is configured to determine the value at the beginning of a surgical procedure.

16. The camera control unit of claim 13 wherein the compensation circuitry further comprises a storage device coupled to or included within the processor for storing the value.

17. A camera control unit adapted for use with a solid state imager which is remotely coupled to the control unit by a cable and is also coupled to driving circuitry, wherein the driving circuitry receives a first timing signal generated in the control unit, and provides at least one driving signal to said imager, and said imager provides, responsive to send at least one driving signal, to said control unit, a composite signal, including an image signal and a second timing signal, the camera control unit comprising:

control circuitry for providing the first timing signal; and

compensation circuitry, coupled to the control circuitry and adapted to be coupled to the solid state imager, for adjusting the phase relationship between the first timing signal and the second timing signal by a value to at least partly compensate for delay through the cable, the compensation circuitry comprising;

a microprocessor for determining the value; and

a programmable delay device coupled to the microprocessor and responsive to the value for adjusting the phase relationship.

18. The camera control unit of claim 17, the compensation circuitry further comprising:

a timing pulse separator for separating the second timing signal from the composite signal; and

a phase detector for determining the phase relationship between the first timing signal and the second timing signal;

wherein the microprocessor is configured to determine the value responsive to the phase relationship determined by the phase detector.

19. The camera control unit of claim 18 wherein the microprocessor in conjunction with the programmable delay device is configured to iteratively determine the value while monitoring the phase relationship determined by the phase detector.

20. A video camera, comprising:

a camera control unit for providing a first signal containing timing information;

a camera head positioned remotely from the camera control unit and coupled thereto by a cable, the camera head including an imager for providing, responsive to the first signal, a second signal containing timing information, the timing information in the first and second signals having a phase relationship;

the cable including at least one signal line for conveying the first signal from the camera control unit to the camera head; and

compensation circuitry coupled to or included within the camera control unit, and also coupled to the camera head through the cable, for adjusting throughout a time period having a duration the phase relationship between the timing information in the first and second signals by a pre-determined value to at least partly compensate for delay through the cable, wherein the pre-determined value is kept fixed for the duration of the time period.

21. A camera control unit adapted for use with a camera head which is remotely coupled to the control unit by a cable, wherein the camera head receives a first signal containing timing information generated in the control unit, and an imager in the camera head provides, responsive to said first signal, a second signal containing timing information, the timing information in the first and second signals having a phase relationship, the camera control unit comprising:

control circuitry for providing the first signal; and

compensation circuitry, coupled to the control circuitry and adapted to be coupled to the imager, for adjusting the phase relationship between the timing information in the first and second signals by a value to at least partly compensate for delay through the cable, the compensation circuitry comprising;

a processor for determining the value; and

a device coupled to the processor and responsive to the value for adjusting the phase relationship.

22. A method for at least partly compensating for delay through a cable in a video camera including a camera control unit and a camera head positioned remotely from the camera control unit and coupled thereto by the cable, the method comprising the steps of:

generating a first signal containing timing information in the camera control unit;

generating in the camera head, responsive to the first signal, a second signal containing timing information, the timing information in the first and second signals having a phase relationship;

passing the second signal through the cable to the camera control unit;

determining during a first time period a value;

storing the value throughout a second time period different from the first time period, the second time period having a duration, such that the value is fixed for the duration of the second time period; and

adjusting, throughout the second time period, the phase relationship between the timing information in the first and second signals by the value to at least partly compensate for delay through the cable.

23. A camera control unit adapted for use with a camera head which is remotely coupled to the control unit by a cable, wherein the camera head receives a first signal containing timing information generated in the control unit, and an imager in the camera head provides, responsive to said first signal, a second signal containing timing information, the timing information in the first and second signals having a phase relationship, the camera control unit comprising:

control circuitry for providing the first signal; and

compensation circuitry, coupled to the control circuitry and adapted to be coupled to the imager, for adjusting throughout a time period having a duration the phase relationship between the timing information in the first and second signals by a pre-determined value to at least partly compensate for delay through the cable, wherein the pre-determined value is kept fixed for the duration of the time period.