Device for measuring the distance of an object from the forward end portion of an endoscope

Claim 2

Device for measuring the distance of an object from the forward end portion of an endoscope adapted to be inserted into a hollow portion of a living body or the like for the inspection thereof, said endoscope comprising a control housing connected to said forward end portion through an elongated tube, an imagetransmitting optical system such as a fiber optical system extending through said elongated tube so as to transmit an image of the object formed in said forward end portion by an objective lens system provided therein through said image-transmitting optical system to said control housing thereby permitting the thus transmitted image to be viewed through ocular means provided in said control housing, a light-projecting means adapted to emit a thin parallel light beam from said forward end portion of the endoscope a certain distance spaced from said objective lens system in the field of view available by the endoscope so as to form a light spot on the surface of the object inspected through the endoscope, and readout means provided in said control housing for reading out the position of said light spot with respect to the field of view inspected Through the endoscope thereby permitting the distance of the object from the forward end portion of the endoscope to be determined on the basis of the thus read out position of the light spot, wherein said readout means comprises a movable indexing mark visible through said ocular means together with the field of view, said movable indexing mark being moved by operating a control mechanism provided in said control housing so that the position of said indexing mark is brought into registration with the light spot on the surface of the object as viewed through said ocular means thereby permitting the distance of the object from the forward end portion of the endoscope to be determined on the basis of the amount of the operation of said control mechanism for bringing said indexing mark into registration with said light spot.

Claim 3

Device according to claim 1 wherein the endoscope is a side-viewing endoscope adapted to inspect an object located at the side of said forward end portion of the endoscope substantially laterally of the longitudinal axis thereof, and said light-projecting means is adapted to emit the thin parallel light beam substantially laterally of the longitudinal axis of said forward end portion toward the object.

Claim 4

Device according to claim 2 wherein said light-projecting means comprises a fiber optical system extending from said control housing through said elongated tube into said forward end portion of the endoscope with the end thereof adjacent to said control housing being illuminated by an external light source to thereby transmit the light through said fiber optical system to the forward end thereof, a collimating lens system located in front of said forward end of said fiber optical system, and light-reflecting means located in front of said collimating lens system so that the thin parallel light beam is emitted from said forward end portion substantially laterally of the longitudinal axis thereof.

Claim 5

Device for measuring the distance of an object from the forward end portion of an endoscope adapted to be inserted into a hollow portion of a living body or the like for the inspection thereof, said endoscope comprising a control housing connected to said forward end portion through an elongated tube, an image-transmitting optical system such as a fiber optical system extending through said elongated tube so as to transmit an image of the object formed in said forward end portion by an objective lens system provided therein through said image-transmitting optical system to said control housing thereby permitting the thus transmitted image to be viewed through ocular means provided in said control housing, a light-projecting means adapted to emit a thin parallel light beam from said forward end portion of the endoscope a certain distance spaced from said objective lens system in the field of view available by the endoscope so as to form a light spot on the surface of the object inspected through the endoscope, and readout means provided in said control housing for reading out the position of said light spot with respect to the field of view inspected through the endoscope thereby permitting the distance of the object from the forward end portion of the endoscope to be determined on the basis of the thus readout position of the light spot, wherein said readout means comprises a stationary index mark visible through said ocular means and the direction of the thin parallel light beam emitted from said light-projecting means is controllable by the operation of a control mechanism provided in said control housing so that the light spot on the surface of the object as viewed through said ocular means is brought into registration with said stationary index mark of said readout means thereby permitting the distance of the object from the forward end portion of the endoscope to be determined on the basis of the amount of the operation of said control mechanism for bringing the light spot into registration with the stationary index mark.

Claim 6

Device for measuring the distance of an object from the forward end portion of an endoscope adapted to be inserted into a hollow portion of a living body or the like for the inspection thereof, said endoscope comprising a control housing connected to said forward end portion through an elongated tube, an image-transmitting optical system such as a fiber optical system extending through said elongated tube so as to transmit an image of the object formed in said forward end portion by an objective lens system provided therein through said image-transmitting optical system to said control housing thereby permitting the thus transmitted image to be viewed through ocular means provided in said control housing, a light-projecting means adapted to emit a thin parallel light beam from said forward end portion of the endoscope a certain distance spaced from said objective lens system in the field of view available by the endoscope so as to form a light spot on the surface of the object inspected through the endoscope, and readout means provided in said control housing for reading out the position of said light spot with respect to the field of view inspected through the endoscope thereby permitting the distance of the object from the forward end portion of the endoscope to be determined on the basis of the thus readout position of the light spot, wherein said readout means comprises a stationary index mark visible through said ocular means and the direction of the thin parallel light beam emitted from said light-projecting means is controllable by the operation of a control mechanism provided in said control housing so that the light spot on the surface of the object as viewed through said ocular means is brought into registration with said stationary index mark of said readout means thereby permitting the distance of the object from the forward end portion of the endoscope to be determined on the basis of the amount of the operation of said control mechanism for bringing the light spot into registration with the stationary index mark.

Claim 7

Device acCording to claim 4 wherein the endoscope is a side-viewing endoscope adapted to inspect an object located at the side of said forward end portion of the endoscope substantially laterally of the longitudinal axis thereof, and said light projecting means is adapted to emit the thin parallel light beam substantially laterally of the longitudinal axis of said forward end portion toward the object.

Claim 8

Device according to claim 4 wherein the endoscope comprises a pair of light projecting means which emit the thin parallel light beams from the forward end portion of the endoscope substantially laterally of the longitudinal axis thereof at positions oppositely spaced a certain distance from the objective lens system, respectively, so as to form two light spots on the surface of the object inspected through the endoscope thereby permitting the distance of the object from the forward end position of the endoscope to be determined on the basis of the positions of said two light spots relative to each other with respect to the field of view of the endoscope as viewed in the focal plane of said ocular means and read out by said readout means.

Claim 9

Device according to claim 4 wherein said light projecting means comprises a fiber optical system extending from said control housing through said elongated tube into said forward end portion of the endoscope with the end thereof adjacent to said control housing being illuminated by an external light source to thereby transmit the light through said fiber optical system to the forward end thereof, a collimating lens system located in front of said forward end of said fiber optical system, and light-reflecting means located in front of said collimating lens system so that the thin parallel light beam is emitted from said forward end portion substantially laterally of the longitudinal axis thereof.