Video endoscope system

A video endoscope system, comprising:

• an illuminating optical system that guides light to an object under examination;
• a light source unit that emits visible light and excitation light for exciting a living tissue of the object to cause fluorescence, said light source unit alternately transmitting the visible light and the excitation light to said illuminating optical system, a period during which said light source unit transmits the visible light to the illuminating optical system and a period during which said light source unit transmits the excitation light to the illuminating optical system being adjustable;
• an objective optical system that converges optical components of light coming from a surface of the object, other than the excitation light, to form an image of the object;
• an image pickup device that picks up the image of the object formed by said objective optical system and converts the image into a video signal;
• and
• a processor that generates a reference video signal based on the video signal obtained by said image pickup device during the period when the visible light is transmitted to said illuminating optical system, and a fluorescence video signal based on the video signal obtained by the image pickup device during the period when the excitation light is transmitted to said illuminating optical system, said processor generating a video signal to be used for diagnosis by subtracting the fluorescence video signal from the reference video signal.

A video endoscope system comprising:

• an illuminating optical system that guides light to an object under examination;
• a light source unit that emits visible light and excitation light for exciting a living tissue of the object to cause fluorescence, and that alternately transmits the visible light and the excitation light to said illuminating optical system so that a period during which the excitation light is transmitted to the illuminating optical system is longer than a period during which the visible light is transmitted to said illuminating optical system;
• an objective optical system that converges optical components of light coming from a surface of the object, other than the excitation light, to form an image of the object;
• an image pickup device that picks up the image of the object formed by said objective optical system and converts the image into a video signal;
• and
• a processor that generates a reference video signal based on the video signal obtained by said image pickup device during the period when the visible light is transmitted to said illuminating optical system, and that generates a fluorescence video signal based on the video signal obtained by the image pickup device during the period when the excitation light is transmitted to said illuminating optical system;
• said light source unit comprising:
• a wheel that rotates around an axis parallel to a light path of the visible light, the wheel comprising a plurality of color filters positioned along a circumference of the wheel, the filters including a blue filter for transmitting only blue light, a green filter for transmitting only green light and a red filter for transmitting only red light;
• and
• a wheel moving mechanism that moves the wheel between a first position, in which the plurality of color filters are sequentially inserted into the light path of the visible light between a light source switching device and said illuminating optical system as the wheel rotates, and a second position, in which the wheel is located out of the light path of the visible light,
• said processor comprising a controller for controlling the light source switching device and the wheel moving mechanism;
• said processor generating a diagnostic video signal by subtracting the fluorescence video signal from the reference video signal in a fluorescent observation mode, in which the controller controls the light source switching device to alternately select the visible light and the excitation light to transmit to said illuminating optical system, and controls the wheel moving mechanism to move the wheel to the second position;
• and
• wherein said processor generates a plurality of color video signals, corresponding to the plurality of color filters, based on video signals obtained by said image pickup device during periods when the corresponding color filters are inserted into the light path of the visible light, and further generates an ordinary video signal representing a color image of the object under examination based on each of the color video signals in an ordinary observation mode, in which the controller controls the light source switching device to select only the visible light to transmit to said illuminating optical system and controls the wheel moving mechanism to move the wheel to the first position.

A video endoscope system comprising:

• an illuminating optical system that guides light to an object under examination;
• a light source unit that emits visible light and excitation light for exciting a living tissue of the object to cause fluorescence, and that alternately transmits the visible light and the excitation light to said illuminating optical system, a period during which the excitation light is transmitted to the illuminating optical system and a period during which the visible light is transmitted to said illuminating optical system being adjustable;
• an objective optical system that converges optical components of light coming from a surface of the object, other than the excitation light, to form an image of the object;
• an image pickup device that picks up the image of the object formed by said objective optical system and converts the image into a video signal;
• and
• a processor that generates a reference video signal based on the video signal obtained by said image pickup device during the period when the visible light is transmitted to said illuminating optical system, and that generates a fluorescence video signal based on the video signal obtained by the image pickup device during the period when the excitation light is transmitted to said illuminating optical system;
• said light source unit comprising:
• a wheel comprising a plurality of color filters positioned along a circumference of the wheel, the filters including a blue filter for transmitting only blue light, a green filter for transmitting only green light and a red filter for transmitting only red light;
• and
• a wheel driver that rotates the wheel and that moves the wheel between a first position, in which the plurality of color filters are sequentially and repeatedly inserted into an optical path of the visible light, and a second position, in which the wheel is retracted from the optical path of the visible light;
• said processor setting said light source unit in one of a fluorescence observation state, in which the visible light and the excitation light are alternately transmitted to said illuminating optical system, and an ordinary observation state, in which only the visible light is transmitted to said illuminating optical system;
• and
• wherein, when said light source unit is set in the fluorescence observation state, said processor controls the wheel driver to move the wheel to the second position and generates a video signal to be used for diagnosis by subtracting the fluorescence video signal from the reference video signal, and when said light source unit is set in the ordinary observation state, said processor controls the wheel driver to rotate the wheel and to move the wheel to the first position and generates a plurality of color video signals respectively based on signals obtained by said image pickup device during periods when the corresponding one of the plurality of color filters are inserted into the optical path of the visible light, said processor generating an ordinary video signal representing a color image of the object under examination based on the plurality of color video signals.