DEVICE FOR DETERMINING THE DISTANCE OF AN OBJECT FROM AN ENDOSCOPE AND DEVICE THEREFOR

• US 3,744,906 A
• Filed: 04/06/1970
• Issued: 07/10/1973
• Est. Priority Date: 07/29/1967
• Status: Expired due to Term

• Current Assignee: Masaaki Sato, Shinya Kosaka, Shoichi Saito
• Original Assignee: Masaaki Sato, Shinya Kosaka, Shoichi Saito
• Inventors: Saito, Shoichi, Sato, Masaaki, Kosaka, Shinya
• Primary Examiner(s): Borchelt, Benjamin A.
• Assistant Examiner(s): Buczinski, S. C.
• Application Number:
  US05/031,060
• Time in Patent Office: 1,191 Days
• Field of Search: 95/11HC 250/205 356/3,4 128/6
• US Class Current: 356/4.07
• CPC Class Codes: A61B 1/00165 with light-conductive means, e.g. fibre optics A61B1/07 takes precedence
• CPC Class Codes: A61B 1/00177 for 90 degrees side-viewing
• CPC Class Codes: A61B 1/04 combined with photographic or television appliances
• CPC Class Codes: G01C 3/00 Measuring distances in line of sight; Optical rangefinders tapes, chains or wheels for measuring length G01B3/00; active triangulation systems, i.e. using the transmission and reflection of electromagnetic waves other than radio waves, G01S17/48
• CPC Class Codes: G03B 37/005 Photographing internal surfaces, e.g. of pipe, G03B37/02 - G03B37/06 take precedence; instruments for performing medical examinations of cavities or tubes of the body by photographic inspection A61B1/00

Abstract

Method for determining the distance of an object from an endoscope which comprises the steps of emitting a light of predetermined intensity and receiving the light reflected from the object having substantially the same reflecting power over the entire area thereof by a photoelectric element, the intensity of the reflected light being the function of the distance from the object, the photo-electric element produces an electrical signal corresponding to the distance. The signal thus produced is recorded and compared with a previously prepared chart indicating the relation between the signal and the distance so that the distance is determined after the operation of the endoscope is completed. The spectroscopic characteristics of the light used for determining the distance is so selected that the film contained in the endoscope for photographing the object is not affected by the light used for determining the distance so that the determination of the distance can be made during the operation of the endoscope. The intensity of the light used for determining the distance is made variable for the better observation of the object while the output of the photoelectric element is varied in inverse proportion to the variation in the intensity of the light so that the correct determination of the distance can be made even though the intensity of the light source is varied. The devices for carrying out each of the above method.

Claims

1. Device for determining the distance between an object having substantially the same reflecting power over the entire area thereof and the forward end portion of an endoscope adapted to be inserted into a hollow portion of a living body or the like and through which the object is photographed, said endoscope comprising a control housing connected to said forward end portion through an elongated flexible tube, the illumination of the object for the photographing thereof being effected by an illuminating means suitable for the exposure of the film contained in the forward end portion of the endoscope and having such photosensitive characteristics that the film is not sensitive over a certain range of the wave lengths of the light, wherein the improvement comprises, in combination, another illuminating means provided in said forward end portion and adapted to emit a light of a predetermined constant intensity and having a range of the wave lengths to which said film is not sensitive, a light receiving photoelectric element provided adjacent to said another illuminating means and adapted to be energized by the light emitted therefrom and received by said photoelectric element after it is reflected from the object so as to generate an electrical signal corresponding to the intensity of said light received by said photoelectric element, and means connected to said photoelectric element for indicating and/or recording said electrical signal, thereby permitting the distance between the object and the forward end portion of the endoscope to be determined by said indicated and/or recorded electrical signal while the film is not affected by the light emitted from said another illuminating means and reflected from the object.

2. Device according to claim 1, wherein the film is of the tungesten type and said another illuminating means is is comprised of a luminous diode made of an arsenic-gallium compound.

3. Device according to claim 1, wherein a D.C. amplifier is interposed between said photoelectric element and said means for indicating and/or recording said electrical signal.

4. Device for determining the distance between an object having substantially the same reflecting power over the entire area thereof and the forward end portion of an endoscope adapted to be inserted into a hollow portion of a living body or the like and through which the object is photgraphed, said endoscope comprising a control housing connected to said forward end portion through an elongated flexible tuBe, wherein the improvement comprises, in combination, an illuminating means adapted to emit a light having a predetermined constant intensity so as to illuminate the object for the photographing thereof, a light receiving photoelectric element adapted to receive the light reflected from the object so as to generate an electrical signal corresponding to the intensity of the light received thereby, means connected to said photoelectric element for automatically determining the proper exposure time in response to said electrical signal and issuing a timing signal, means connected to said means for determining the proper exposure time and said illuminating means for deenergizing said illuminating means in response to said timing signal after the proper exposure time has elapsed, means connected to said means for deenergizing said illuminating means for detecting said proper exposure time, and means for recording the thus detected proper exposure time, thereby permitting the distance between the object and the forward end portion of the endoscope to be determined on the basis of the thus recorded proper exposure time which is the function of said electrical signal, said device further comprising a D.C. amplifier interposed between said photoelectric element and said means for determining the proper exposure time, means connected to said amplifier for indicating the output thereof and provided with a calibration chart indicating the relationship between the proper exposure time and the distance between the object and the forward end portion of the endoscope, so that said indicated output of said amplifier is compared with said calibration chart so as to determine the distance to be sought.

5. Device for determining the distance between an object having substantially the same reflecting power over the entire area thereof and the forward end portion of an endoscope adapted to be inserted into a hollow portion of a living body or the like and from which an image of the object formed by means of an objective lens system is transmitted through an image transmitting optical system such as a fiber optical system extending from said forward end portion through an elongated flexible tube to a control housing connected to said forward end portion through said elongated flexible tube so as to be viewed through an ocular means provided in said housing, wherein the improvement comprises, in combination, an illuminating means adapted to emit a light of a predetermined intensity so as to illuminate the object, a light receiving photoelectric element provided in the endoscope for receiving the light issuing from said illuminating means and reflected from the object so as to generate an electrical signal corresponding to the intensity of said light received by said photoelectric element, means connected to said photoelectric element, means connected to said photoelectric element for indicating and/or recording said electrical signal, thereby permitting the distance between the object and the forward end portion of the endoscope to be determined on the basis of said indicated and/or recorded electrical signal which is the function of the intensity of the light emitted from said illuminating means and received by said photoelectric element after it is reflected from the object, said device further comprising means for adjusting the intensity of the light emitted from said illuminating means for making the intensity of light suitable for the viewing of the object, and means operatively connected to said adjusting means and said indicating and/or recording means for varying the electrical signal in inverse proportion to the variation in the intensity of the light effected by said adjusting means so as to compensate therefor, thereby permitting the distance between the object and the forward end portion of the endoscope to be correctly determined despite the intensity of the light received by said photoelectric element being varied by the adjustment of the intensity of the light illuminating the object by means of sAid adjusting means.

6. Device according to claim 5, wherein said device comprises means in said forward end portion of the endoscope for photographing the object, and means being provided for switching said adjusting means so as to emit the intensive light for the photographing of the object from said illuminating means each time said device is operated for the photographing of the object while the intensity of the light is normally kept adjustable for the proper viewing of the object.

7. Device according to claim 5 wherein said adjusting means comprises a pair of relatively shiftable blades operatively coupled with said adjusting means and located in the path of the light emitted from said illuminating means and each provided with the corresponding row of a plurality of elongated slits of the same size extending substantially normal to the direction of the row so that, by shifting one of said blades relatively to the other by the operation of said adjusting means, the positions of said elongated slits in one of the blades relative to those in the other are varied so as to adjust the intensity of the light passing therethrough, and said switching means comprises a rotary solenoid carrying said blades which is energized each time the device is operated for the photographing of the object so as to move said blades out of the path of the light emitted from said illuminating means.

8. Device according to claim 5 wherein said adjusting means comprises a pair of oppositely swingable blades located in the path of the light emitted from said illuminating means for adjusting the intensity of the light passing between said blades and pivotably mounted on one end of a first lever which is moved by means of a solenoid energizable by the operation of the device for the photographing of the object, each of said blades being provided with a diagonally extending elongated slot oppositely inclined to each other, a pin fixed to one end of a second lever adjustable by the operation of said adjusting means being slidably engaged in said diagonally extending slot in each of said blades thereby permitting the intensity of the light passing through between said blades to be adjusted for the proper illumination of the object for the viewing thereof by actuating said adjusting means while the intensive light from said illuminating means is permitted to pass between said blades without being interrupted thereby when the device is operated for the photographing of the object by the energization of said solenoid so as to move the pivoted ends of said blades so that said blades are moved out of the path of the light emitted from said illuminating means.

9. Device according to claim 5, wherein said light receiving photoelectric element is located adjacent to said illuminating means.

10. Device for determining the distance between an object having substantially the same reflecting power over the entire area thereof and the forward end portion of an endoscope adapted to be inserted into a hollow portion of a living body or the like and from which an image of the object formed therein by means of an objective lens system is transmitted through an image transmitting optical system such as a fiber optical system extending from said forward end portion through an elongated flexible tube to a control housing connected to said forward end portion through an ocular means provided in said housing, wherein the improvement comprises, in combination, an illuminating means adapted to emit a light of a predetermined intensity so as to illuminate the object, a light receiving photoelectric element provided in the endoscope for receiving the light issuing from said illuminating means and reflected from the object so as to generate an electrical signal corresponding to the intensity of said light received by said photoelectric element, means connected to said photoelectric element for indicating and/or recording said electrical signal, thereby permitting the distance between the object and the forward end Portion of the endoscope to be determined on the basis of said indicated and/or recorded electrical signal which is the function of the intensity of the light emitted from said illuminating means and received by said photoelectric element after it is reflected from the object, said device further comprising means for adjusting the intensity of the light emitted from said illuminating means for making the intensity of light suitable for the viewing of the object, and means operatively connected to said adjusting means and said indicating and/or recording means for varying the electrical signal in inverse proportion to the variation in the intensity of the light effected by said adjusting means so as to compensate therefor, thereby permitting the distance between the object and the forward end portion of the endoscope to be correctly determined despite the intensity of the light received by said photoelectric element being varied by the adjustment of the intensity of the light illuminating the object by means of said adjusting means, said illuminating means comprising a light conducting fiber optical system extending through said elongated flexible tube with the forward end thereof being positioned in said forward end portion of the endoscope so as to illuminate the object and with the rearward end thereof terminating at a position adjacent to or in said control housing so that the rearward end of said light conducting fiber optical system is illuminated by an external light source to thereby transmit the light conducting fiber optical system to the forward end thereof so as to be emitted therefrom.