Endoscope apparatus and measuring method

Abstract

An endoscope apparatus and a measuring method measure a subject using a pattern projection image obtained by projecting a fringe pattern onto a subject. The endoscope apparatus includes an elongated insertion section, an imaging section at a tip portion of the insertion section to acquire the image of a subject, an illumination section at the tip portion of the insertion section to emit the illumination light that illuminates an observation visual field of the imaging section, and a pattern projection section at the tip portion of the insertion section to project a fringe pattern onto the subject. A tip surface of the insertion section includes an objective optical system that forms the image of the subject on the imaging section, one or more illumination windows through which illumination light is emitted, and one projection window through which a fringe pattern is projected onto the subject from the pattern projection section.

1 . An endoscope apparatus that measures a subject using a pattern projection image of the subject on which a light and dark pattern of light is projected, the endoscope apparatus comprising:
 an insertion section;   an imaging section that is provided at a tip portion of the insertion section to acquire the image of the subject;   an illumination section that emits illumination light that illuminates an observation visual field of the imaging section; and   a pattern projection section that projects the light and dark pattern onto the subject,   wherein a tip surface of the insertion section is provided with:   an objective optical system that forms the image of the subject on the imaging section;   one or more illumination window through which the illumination light is emitted; and   a projection window through which the light and dark pattern is projected onto the subject from the pattern projection section;   the pattern projection section includes a pattern generator which generates the light and dark pattern; and   the light and dark pattern is a pattern with an intensive distribution in which a light portion and a dark portion are alternately arranged.   
     
     
         2 . The endoscope apparatus according to  claim 1 ,
 wherein the objective optical system is arranged so that an optical axis on an emission side that is directed to the imaging section from the objective optical system among optical axes of the objective optical system is parallel to and eccentric from a central axis of the insertion section.   
     
     
         3 . The endoscope apparatus according to  claim 2 ,
 wherein the objective optical system is a direct-view-type objective optical system in which both an optical axis on an incidence and the optical axis on the emission are parallel to the central axis, and   wherein the objective optical system is provided at the tip surface of the tip portion of the insertion section and is arranged at a position eccentric from the central axis.   
     
     
         4 . The endoscope apparatus according to  claim 3 ,
 wherein the projection window is provided at the tip surface and is arranged at a position eccentric from the central axis of the insertion section.   
     
     
         5 . The endoscope apparatus according to  claim 2 ,
 wherein the objective optical system is a side-view-type objective optical system that is exposed to an outer peripheral surface of the tip portion of the insertion section and has an optical axis on an incidence side arranged at a twisted position with respect to the central axis.   
     
     
         6 . The endoscope apparatus according to  claim 5 ,
 wherein the projection window is exposed to an outer peripheral surface of the tip portion of the insertion section, and   wherein a centerline extending in the thickness direction of the projection window through the center of the projection window when the projection window is viewed from the thickness direction of the projection window is arranged at a twisted position with respect to the central axis of the insertion section.   
     
     
         7 . The endoscope apparatus according to  claim 2 ,
 wherein the objective optical system is a side-view-type objective optical system that is exposed to an outer peripheral surface of the tip portion of the insertion section, the objective optical system having an optical axis on an incidence side arranged to intersect the central axis of the insertion section, and   wherein the projection window is arranged in the outer peripheral surface of the tip portion of the insertion section so that the center of the projection window is present in a plane defined by the central axis of the insertion section and the optical axis on the incidence side when the projection window is viewed from the thickness direction of the projection window.   
     
     
         8 . The endoscope apparatus according to  claim 1 ,
 wherein the pattern projection section includes one or more linear parallel pattern.   
     
     
         9 . The endoscope apparatus according to  claim 1 ,
 wherein the pattern projection section includes a projecting light source, and a pattern generator that changes the intensity distribution of the light emitted from the projecting light source and generates the light and dark pattern.   
     
     
         10 . The endoscope apparatus according to  claim 9 , further comprising:
 an optical fiber that guides the light emitted from the projecting light source, to the pattern generator,   wherein the projecting light source is provided on a base end side of the insertion section, and   wherein the pattern generator is provided at the tip portion of the insertion section.   
     
     
         11 . The endoscope apparatus according to  claim 9 ,
 wherein the projecting light source and the pattern generator are provided at the tip portion of the insertion section.   
     
     
         12 . The endoscope apparatus according to  claim 9 , further comprising:
 an optical fiber that guides the light and dark pattern emitted from the projecting light source and generated by the pattern generator to a tip side of the insertion section,   wherein the projecting light source and the pattern generator are provided on a base end side of the insertion section.   
     
     
         13 . The endoscope apparatus according to  claim 9 , further comprising:
 an optical adapter capable of being detachably mounted on the tip portion of the insertion section,   wherein the pattern generator is provided at the optical adapter.   
     
     
         14 . The endoscope apparatus according to  claim 13 ,
 wherein the projecting light source is provided at the optical adapter.   
     
     
         15 . The endoscope apparatus according to  claim 1 , further comprising:
 switching means for switching between the light for projecting the light-and-dark-pattern and the illumination light.   
     
     
         16 . A measuring method that performs the three-dimensional shape measurement of a subject using an endoscope apparatus, the method comprising:
 projecting a predetermined light and dark pattern onto the subject from one place of the endoscope apparatus;   imaging the portion of the subject onto which the light and dark pattern is projected, and acquiring at least one sheet of a pattern projection image; and   performing the three-dimensional shape measurement of the portion onto which the light and dark pattern is projected, using the pattern projection image.   
     
     
         17 . A measuring method that measures a subject using a pattern projection image of the subject onto which a light and dark pattern of light is projected, the method comprising:
 projecting the predetermined light and dark pattern onto the subject from one place of the endoscope apparatus;   imaging the portion of the subject onto which the light and dark pattern is projected, and acquiring one sheet of a pattern projection image; and   performing the three-dimensional shape measurement of the portion onto which the light and dark pattern is projected, according to the one sheet of pattern projection image, using a spatial phase shift method or a Fourier transform method.   
     
     
         18 . The measuring method according to  claim 17 , further comprising:
 acquiring at least one sheet of a bright field image of the portion onto which the light and dark pattern is projected, at least either before or after the one sheet of pattern projection image is acquired;   selecting at least two sheets of images from the one sheet of pattern projection image and the bright field images; and   detecting that the position of the endoscope apparatus has deviated when there is a positional deviation equal to or more than a predetermined amount in the two sheets of images.   
     
     
         19 . The measuring method according to  claim 18 , further comprising:
 acquiring at least one sheet of the bright field images before and after the one sheet of pattern projection image is acquired, respectively.   
     
     
         20 . The measuring method according to  claim 19 ,
 wherein at least two sheets of images selected to detect that the position of the endoscope apparatus has deviated are selected from the bright field images.   
     
     
         21 . An endoscope apparatus that measures a subject using a pattern projection image of the subject on which a light and dark pattern of light is projected, the endoscope apparatus comprising:
 an insertion section;   imaging means for acquiring the image of the subject;   illumination means for emitting illumination light that illuminates an observation visual field of the imaging means; and   pattern projection means for projecting the light and dark pattern onto the subject,   wherein the insertion means includes:   means for forming the image of the subject on the imaging means;   means for allowing the illumination light to emit through; and   means for projecting the light and dark pattern on to the subject from the pattern projection means,   wherein the pattern projection means includes a pattern generate means for generating the light and dark pattern; and   wherein the light and dark pattern is a pattern with an intensive distribution in which a bright portion and a dark portion are alternately configured.