Video imaging systems and method using a single interline progressive scanning sensor and sequential color object illumination

• US 5,394,187 A
• Filed: 11/22/1993
• Issued: 02/28/1995
• Est. Priority Date: 06/26/1992
• Status: Expired due to Term

• Current Assignee: Surgicon, Inc.
• Original Assignee: Apollo Camera, LLC
• Inventors: Shipp, John I.
• Primary Examiner(s): Groody, James J.
• Assistant Examiner(s): HSIA, SHERRIE Y
• Application Number:
  US08/156,377
• Time in Patent Office: 463 Days
• Field of Search: 348/222, 348/234, 348/266, 348/268, 348/269, 348/322
• US Class Current: 348/269
• CPC Class Codes: H04N 13/194 Transmission of image signals
• CPC Class Codes: H04N 13/211 using temporal multiplexing
• CPC Class Codes: H04N 13/218 using spatial multiplexing
• CPC Class Codes: H04N 13/239 using two 2D image sensors having a relative position equal to or related to the interocular distance H04N13/243 takes precedence
• CPC Class Codes: H04N 13/254 in combination with electromagnetic radiation sources for illuminating objects
• CPC Class Codes: H04N 13/257 Colour aspects
• CPC Class Codes: H04N 13/296 Synchronisation thereof; Control thereof
• CPC Class Codes: H04N 13/341 using temporal multiplexing
• CPC Class Codes: H04N 13/398 Synchronisation thereof; Control thereof
• CPC Class Codes: H04N 23/84 for processing colour signals

Abstract

A sequential video imaging system uses a video sensor having interline architecture whereby image data is moved from sensor elements to adjacent interlined storage elements. The object being viewed is sequentially illuminated with colored light sources to produce luminance and chrominance video signals. Binning of image data corresponding to low level color signals is carried out in the sensor. A digital signal processor includes data buffering and averaging circuits whereby the camera head and base unit can be operated asynchronously.

Claims

1. A sequential color video imaging system for viewing an object, said system comprising:

a. an interline video sensor having an image array of horizontal and vertical photosensitive elements and a corresponding storage array of video data storage elements, said photosensitive elements responsive to levels of light reflection from the object;

b. object illumination means to illuminate the object, said object illumination means including separately operable red, green, and blue light sources;

c. timing and driver means operably connected to said object illumination means to activate said red, green, and blue light sources in a pre-determined repeating sequence of red and green, red, red and green, and blue light illumination periods;

d. sensor driver means operably connected to said sensor to shift the video data responsive to the level of light reflected from the object during each of said illumination periods from said image array to said storage array; and

e. processor means operably connected to said storage array of said sensor, to read and transform the video data shifted to said storage array into a corresponding sequence of chrominance and luminance video signals representing the object viewed by said imaging system.

2. The system of claim 1 further comprising video amplifier means to amplify the video data from said storage array before processing in said processor means, said amplifier means having a signal gain which is switchable in response to an external signal whereby differing amplifier gains can be applied to the video data corresponding to different illumination colors.

3. The system of claim 2, said video sensor further comprising a parallel video data shift register, a serial video data shift register, and means responsive to binning signals from said sensor driver means whereby at least two vertical lines of the video data corresponding to a single illumination color from said storage array are summed in said parallel shift resister, and whereby at least two horizontal lines of the video data are summed from said parallel shift register into said serial shift register, and said sensor driver means including means to generate said binning signals whereby a matrix of at least a 2×

2 array of said photosensitive elements having red or blue video data are summed in said sensor before further processing.

4. The system of either of claims 2 or 3, said processor means comprising video data averaging and video data subtraction circuits.

5. The system of either claim 2, or 3 further comprising means for wireless transmission of said video data to a remote location.

6. An improved method of processing video data in a sequential color video camera comprising the steps of:

a. illuminating an object to be viewed with repeating sequences of red and green, red, red and green, and blue light during corresponding luminance signal, first chrominance signal, luminance signal, and second chrominance signal illumination periods;

b. sensing and integrating in a video data sensor array a level of light reflected by the object during each of said luminance signal and said first and second chrominance signal illumination periods;

c. shifting at the end of each of said luminance and first and second chrominance signal illumination periods, the video data from said video data sensor array into a video data storage array;

d. reading the video data stored in said video data storage array into a video amplifier;

e. processing the video data outputted from said video amplifier corresponding to said luminance signal illumination periods to produce a luminance video signal; and

f. processing the video data outputted from said video amplifier corresponding to said first and second chrominance illumination periods to produce first and second chrominance video signals.

7. The method of claim 6 wherein said luminance signal illumination periods have a duration of a fraction of the duration of said first and second chrominance signal illumination periods, said fraction determined by a readout time of said first and second chrominance signals.

8. The method of claim 7 further comprising the step of binning in said video data sensor array at least two vertical lines of the video data integrated in said sensor array during said first and second chrominance signal illumination periods, producing binned red and blue video signals whereby video image signal strengths corresponding to red and blue light illumination of the object are increased.

9. The method of claim 8 wherein said processing of the video data includes averaging of luminance signals to provide an averaged luminance signal whereby said averaged luminance signal temporally matches said binned red and blue video signals, and wherein said first chrominance video signal is obtained by subtracting said binned red signal from said averaged luminance signal and said second chrominance signal is obtained by subtracting said binned blue signal from said averaged luminance signal.

10. The method of claim 6 further comprising the step of switching in a predetermined sequential manner said video data from said video amplifier among Y storage and first and second chrominance memory units.