Electronic endoscope with brightness adjustment function
First Claim
1. An electronic endoscope comprising:
- a video-scope with an image sensor;
a light source that emits illuminating-light for illuminating an object;
an image sensor driver that outputs pulse signals for transferring charges accumulated in said image sensor in each field/frame interval, said image sensor driver outputting a pulse signal for discarding accumulated charges on the basis of a charge accumulation interval;
a luminance detector that detects a luminance of an object image on the basis of image-pixel signals read from said image sensor;
a single rotary shutter comprising a light-transmitting portion that transmits the illuminating-light, and a shield portion that blocks the illuminating light, said single rotary shutter being configured to rotate while the light-transmitting portion and the shield portion alternately cross a light-path of the illuminating-light; and
a brightness adjuster that controls said rotary shutter to change an irradiation-interval of the illuminating-light in a field/frame interval in accordance with the charge accumulation interval, said brightness adjuster shifting a rotation-phase of said rotary shutter by changing a rotation-speed of the rotary shutter on the basis of the detected luminance, so as to maintain a brightness of the object image at a proper brightness.
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Accused Products
Abstract
An electronic endoscope has a video-scope with an image sensor, a light source that emits illuminating-light to illuminate an object, an image sensor driver, a luminance detector, one rotary shutter, and a brightness adjuster. The luminance detector detects a luminance of an object image on the basis of image-pixel signals read from the image sensor. The rotary shutter has a light-transmitting portion that transmits the illuminating light, and a shield portion that blocks the illuminating light. The brightness adjuster controls the rotary shutter to adjust an irradiation-interval of the illuminating-light in accordance with a charge accumulation interval. The brightness adjuster shifts a rotation-phase of the rotary shutter by changing a rotation-speed on the basis of the detected luminance, so as to maintain a brightness of the object image at a proper brightness.
73 Citations
20 Claims
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1. An electronic endoscope comprising:
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a video-scope with an image sensor; a light source that emits illuminating-light for illuminating an object; an image sensor driver that outputs pulse signals for transferring charges accumulated in said image sensor in each field/frame interval, said image sensor driver outputting a pulse signal for discarding accumulated charges on the basis of a charge accumulation interval; a luminance detector that detects a luminance of an object image on the basis of image-pixel signals read from said image sensor; a single rotary shutter comprising a light-transmitting portion that transmits the illuminating-light, and a shield portion that blocks the illuminating light, said single rotary shutter being configured to rotate while the light-transmitting portion and the shield portion alternately cross a light-path of the illuminating-light; and a brightness adjuster that controls said rotary shutter to change an irradiation-interval of the illuminating-light in a field/frame interval in accordance with the charge accumulation interval, said brightness adjuster shifting a rotation-phase of said rotary shutter by changing a rotation-speed of the rotary shutter on the basis of the detected luminance, so as to maintain a brightness of the object image at a proper brightness. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An apparatus for adjusting a brightness of an object image in an electronic endoscope, comprising:
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a luminance detector that detects a luminance level of an object image on the basis of image-pixel signals that are read from an image sensor of a video-scope successively; a single rotary shutter comprising a light-transmitting portion and a shield portion, said single rotary shutter being configured to rotate while the light-transmitting portion and the shield portion alternately cross a light-path of the illuminating-light; and a brightness adjuster that controls said rotary shutter to adjust an irradiation interval of the illuminating light in a field/frame interval in accordance with a charge accumulation interval of said image sensor, said brightness adjuster changing an overlapping interval of the irradiation interval and the charge accumulation interval by shifting a rotation-phase of said rotary shutter on the basis of the detected luminance level, so as to maintain a brightness of the object image at a proper brightness. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. A method for adjusting a brightness of an object image in an electronic endoscope, comprising:
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detecting a luminance level of an object image on the basis of image-pixel signals that are read from an image sensor of a video-scope successively; rotating a single rotary shutter that comprises a light-transmitting portion and a shield portion, such that the single rotary shutter rotates while the light-transmitting portion and the shield portion alternately cross a light-path of the illuminating-light; and controlling the rotary shutter to adjust an irradiation interval of the illuminating light in a field/frame interval in accordance with a charge accumulation interval of the image sensor, the controlling comprising changing an overlapping interval of the irradiation interval and the charge accumulation interval by shifting a rotation-phase of the rotary shutter on the basis of the detected luminance level, so as to maintain a brightness of the object image at a proper brightness. - View Dependent Claims (16, 17, 18, 19, 20)
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Specification