Endoscope signal level control

Claim 1

In a video endoscope having a solid state image sensor located in the viewing head of an instrument for recording light images of a target and clocking out the image data in the form of a video signal, a video signal level control apparatus that includes a lamp for illuminating a target in the viewing range of the image sensor whereby image data of the target recorded by the sensor is clocked out as a video signal, a color wheel for passing a series of different color filters in series through the illumination beam of the lamp in synchronism with each video field to image the target sequentially with light of each different color in synchronism with each said field, lamp driver means having an individual lamp amplitude control for regulating the illumination intensity of the lamp during each color imaging sequence, each lamp amplitude control having an adjustable voltage divider for connecting the lamp to a common voltage supply so that the color intensity of the images recorded by the sensor during a field can be proportionally balanced, detector means for sensing the level of the video signals clocked out of the image sensor and providing a variable output signal indicative of the video signal level, and adjusting means for automatically regulating the common supply voltage to the lamp amplitude controls in response to the said variable output signal of the detector means to maintain the video signal at a desired level without disturbing the balance of the recorded color images.

Claim 7

The method of controlling the signal level of a video endoscope having a single lamp for illuminating a target and a color wheel for passing different color filters through the illumination beam of the lamp in sychronism with each video field to provide color-separated images of the target, providing a solid state image sensor for sequentially recording the color-separated images in sychronism with each field and clocking out the image data as a video signal, setting the illumination intensity of the lamp during each color imaging sequence so that the color images are proportionally balanced, sensing the level of the video signal clocked out of the image sensor, and equally adjusting the illumination intensity of the lamp during each color imaging sequence to maintain the video signal at a desired level without disturbing the color balance.

Claim 8

The method of controlling the signal level of a video endoscope having a single lamp for illuminating a target and a color wheel for passing different color filters through the illumination beam of the lamp in sychronism with each video field to provide color-separated images of the target, providing a solid state image sensor for sequentially recording the color-separated images in sychronism with each field and clocking out the image data as a video signal, setting the illumination intensity of the lamp during each color imaging sequence so that the color images are proportionally balanced, sensing the level of the video signal clocked out of the image sensor, and equally adjusting the illumination intensity of the lamp during each color imaging sequence to maintain the video signal at a desired level without disturbing the color balance.