JP2005287900A - Endoscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an endoscope capable of measuring the three-dimensional shape of an object to be observed speedily and highly precisely. <P>SOLUTION: In the endoscope 10, a plurality of projection rays 44 projected from a projection lens system 26 on the object 42 to be observed are photographed by respective photography elements 24, and based on the image photographed by each photography element 24, the position coordinate of each projection ray 44 on the object 42 to be observed is calculated and the three-dimensional shape of the object 42 to be observed is measured. Since the position coordinates of the plurality of projection rays 44 on the object 42 to be observed are calculated by a control part 38, scanning of the projection rays 44 is not necessary, so that the three-dimensional shape of the object 42 to be observed can be measured at high speed. Furthermore, since the position coordinates of the projection rays 44 on the object 42 to be observed are calculated by the control part 38 based on the images photographed by the photography elements 24, even the length not more than the three-dimensional resolution of the photography elements 24 can be measured, so that the three-dimensional shape of the object 42 to be observed can be measured highly precisely. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an endoscope, and more particularly, to an endoscope that can be used for medical use or industrial use that can measure a three-dimensional shape (three-dimensional shape) of an observation target.

  Endoscopes include medical endoscopes that observe, diagnose, or treat organs such as the stomach, intestines, bronchi, lungs, bladder, and kidneys in the body, and gaps and pipes in various mechanical devices and equipment. 2. Description of the Related Art Industrial endoscopes are known that observe or manipulate narrow places such as cracks and gaps in caves in nature and places that are difficult to observe.

  Since such an endoscope is generally a monocular, it cannot not only observe the observation object in three dimensions but also cannot measure the three-dimensional shape of the observation object. In a conventional endoscope, the size of the field of view of the endoscope and the distance between the endoscope and the observation target are estimated, and the degree of focus blur of the endoscope and the movement of the endoscope are estimated. By considering the movement of the image and the like, it is only possible to estimate the approximate three-dimensional shape of the observation target.

  An endoscope called a three-dimensional endoscope or a three-dimensional endoscope or the like in which two cameras, image fibers, and the like are arranged at an appropriate interval to enable stereoscopic viewing of an observation target. Has been developed.

  However, with this stereoscopic endoscope, although it is possible to capture the unevenness of the surface of the observation target by stereoscopic viewing of the observation target, it is impossible to measure the distance between the endoscope and the observation target. The three-dimensional shape cannot be measured. In order to solve this problem, endoscopes that can measure the distance to the observation target have been developed (see, for example, Patent Document 1 and Patent Document 2).

  In the endoscope of Patent Document 1, one measurement light (spot light) is projected onto an object, and this measurement light is photographed by two cameras, thereby applying the principle of triangulation to the endoscope. The distance between the mirror tip and the measurement light on the object is calculated.

In the endoscope of Patent Document 2, a projection system and an imaging system are installed at the tip of a thin scope, and a fine stripe pattern is projected from the projection system onto an observation point. By taking a picture, the principle of triangulation is applied to measure the three-dimensional shape of the observation site from the deviation of the stripe pattern.
Japanese Patent No. 2875832 JP-A-2-297515

  However, in the endoscope of Patent Document 1, in order to measure the three-dimensional shape of the object on the entire screen captured by the camera, it is necessary to scan the measurement light over the entire screen, and this scanning requires time. There is a problem. Therefore, it is difficult to accurately measure the three-dimensional shape of an object that moves or deforms during measurement. In particular, medical endoscopes are affected by vibrations such as body movement, breathing, and heartbeat during measurement, and it is difficult to accurately measure the three-dimensional shape of an object.

  In the endoscope of Patent Document 2, since the projection system and the imaging system are installed at the tip of a thin scope, the baseline length (distance between the projection system and the imaging system) that is important for performing triangulation is used. ) Is difficult to lengthen. For this reason, it is described that the distance between the practical scope tip and the observation point is about 2.5 cm, and when the distance between the scope tip and the observation point becomes large, the three-dimensional shape of the observation point is changed. There arises a problem that measurement cannot be performed with high accuracy.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an endoscope capable of measuring a three-dimensional shape of an observation target with high speed and high accuracy.

  In order to achieve the above object, an endoscope of the present invention is configured to project a pattern image having a plurality of measurement points onto an observation target and to capture the pattern image projected onto the observation target from different positions. And a plurality of photographing means arranged at predetermined intervals, and a computing means for computing the position coordinates of each of the measurement points based on images photographed by each of the photographing means. .

  In the present invention, a pattern image having a plurality of measurement points is projected onto the observation target by the projection means, and the pattern image projected on the observation target is photographed from different positions by the plurality of photographing means arranged at predetermined intervals. . Since the plurality of photographing means are arranged at a predetermined interval, parallax occurs between images photographed by the photographing means. Further, the position coordinates of each measurement point of the pattern image projected onto the observation target are calculated by the calculation means based on the images shot by each of the shooting means. Since the three-dimensional information is obtained from the calculated position coordinates, the three-dimensional shape of the observation target can be measured.

  In the present invention, a pattern image having a plurality of measurement points is projected onto an observation object, and the position coordinates of each measurement point of the projected pattern image are calculated, so that the three-dimensional shape of the observation object can be obtained without scanning. It can be measured. For this reason, the three-dimensional shape of the observation object can be measured at high speed.

  Furthermore, since the position coordinates of each measurement point are calculated based on the images photographed by each photographing means, it is possible to measure even with a length less than the stereoscopic resolution of the photographing means. For this reason, the three-dimensional shape of the observation target can be measured with high accuracy.

  In the endoscope of the present invention, it is preferable that the projection modes of the measurement points projected on the observation target are different from each other so that the measurement points can be distinguished from each other. Thereby, the same measurement point can be easily made to correspond between the captured images of the respective imaging means, and thereby the position coordinates of the measurement point can be easily calculated.

  In order to be able to distinguish each measurement point, it is effective to form each measurement point by irradiating light having a constant light amount and different colors (wavelengths or spectra). As a result, a plurality of measurement points having a constant luminance and different colors are projected, so that it is possible to distinguish each of the measurement points by modulating the intensity of light of a single color. It is possible to easily shoot even if the dynamic range is narrow.

  Furthermore, it is preferable that the endoscope of the present invention further includes display means for displaying a distribution of points corresponding to the position coordinates based on the calculated position coordinates. Thereby, the three-dimensional shape of the observation target can be easily grasped.

  As described above, according to the endoscope of the present invention, there is an effect that the three-dimensional shape of the observation target can be measured at high speed and with high accuracy.

[First Embodiment]
Next, a first embodiment in which the present invention is applied to an electronic endoscope will be described. FIG. 1 is a cross-sectional view showing the internal configuration of the endoscope 10 according to the first embodiment of the present invention.

  The endoscope 10 includes a long cylindrical insertion portion 12 and a processing portion 14 connected to a proximal end 12B of the insertion portion 12. In addition, on the distal end side of the insertion portion 12 of the endoscope 10, there are provided two imaging devices 16 arranged at a predetermined interval and a projection device 18 that projects a pattern having a plurality of measurement points P onto the observation object 42. It has been.

  Each photographing device 16 includes a photographing lens 22 and a CCD camera 20 having a photographing element 24 capable of photographing images of different wavelength bands such as a color CCD. The photographing lens 22 is on the distal end 12A side of the insertion portion 12. The photographing element 24 is disposed at the image forming position of the photographing lens 22. Since each photographing device 16 is arranged at a predetermined interval, parallax occurs between images photographed by the CCD cameras 20. In the present embodiment, the CCD camera 20 is arranged so that the optical axis of the photographing lens 22 is parallel, but may be arranged so that the optical axes of the photographing lens 22 intersect.

  The projection device 18 is provided with a projection lens system 26 disposed at a position different from each photographing lens 22 on the distal end side of the insertion portion 12. As shown in FIG. 2, the projection lens system 26 is a lens system having a wide angle of view and low aberration such as a triplet type or a Gauss type, which includes two convex lenses 28 and one concave lens 30 disposed between the convex lenses 28. It is configured.

  A condenser lens 32 is disposed on the light incident side of the projection lens system 26 in the insertion unit 12, and a light source 34 is disposed on the light incident side of the condenser lens 32. The light source 34 can be composed of a light source that emits high-luminance and low-coherent light, such as a semiconductor laser, a superluminescent diode, or a light-emitting diode.

  A projection pattern plate 36 is disposed between the projection lens system 26 and the condenser lens 32. As shown in FIG. 3, the projection pattern plate 36 is formed with a two-dimensional transmission pattern 36A for each of a plurality of square-shaped specific ranges arranged in a lattice pattern. As shown in FIG. 4, the transmissive pattern 36A includes four cross-shaped transmissive portions 37A that are arranged so that the centers thereof coincide with the centers of the specific ranges, and the cross-shaped transmissive portions 37A. There are provided a plurality of dot-shaped transmission portions 37B that are capable of transmitting light provided in one region. The cross-shaped transmission part 37A can be changed to a plurality of point-like transmission parts 37B.

  On the projection pattern plate 36, like a cover slide, a transmission pattern 36A for changing the color of transmitted light and modulating the transmitted light is formed in a lattice pattern for each of a plurality of transmitting portions 37B in each specific range. It is comprised with the glass plate, the plastic plate, etc. which were made. The transmissive portions 37B are arranged in a grid with a predetermined number, for example, 10 × 10 equally spaced pitches, and are configured such that the amount of light transmitted from each transmissive portion 37B is constant and the color of the transmitted light is different. Yes. That is, each transmission part 37B is configured by evaporating a color filter so that each of red light, green light, and blue light transmits at different ratios, and the amount of light transmitted by each transmission part 37B is the same. ing. For example, when the minimum value of the relative intensity of red light, green light, and blue light is 0 and the maximum value is 228, as shown in the table of FIG. The combinations of the relative intensities are different, and the total of the relative intensities of red light, green light, and blue light is constant (228 in the example of FIG. 5) in each transmission portion 37B.

  Thereby, the projection light 44 irradiated from the projection lens system 26 is irradiated to the observation object corresponding to the transmission pattern 36A provided for each specific range of the projection pattern plate 36, and each measurement is performed for each square specific range. The dots (dot-like projection light 44) are projected in the same pattern. Each measurement point is spectrally modulated by the projection pattern plate 36 and projected so that the color of each measurement point P of the projection pattern is different, so that each measurement point can be identified. The projection light 44 projected onto the observation object 42 preferably uses light that is not absorbed by the observation object 42 (particularly blood in the case of the medical endoscope 10). When the projection light 44 interferes with observation, infrared light or ultraviolet light and the imaging element 24 sensitive to these lights can be used.

  The processing unit 14 is connected to the imaging elements 24 and the light source 34 via lead wires 40 arranged in the insertion unit 12, and based on the images captured by the CCD camera, measurement points are measured. A control unit 38 composed of a microcomputer for calculating each three-dimensional position coordinate is provided. Connected to the control unit 38 are a switch 46 that is operated during measurement of the three-dimensional shape, and a monitor 48 that displays the three-dimensional shape.

  Next, calculation of the three-dimensional position coordinates of each measurement point executed by the control unit 38 will be described. First, as shown in FIG. 6, the XY plane is determined so as to include the optical axis of each photographing lens 22, and a straight line passing through the centers of the two photographing lenses 22 becomes the Y axis, and the center between the photographing lenses 22 is the origin. The XY coordinates are determined so that Further, the center of each photographing lens 22 is (0, Yd1), (0, Yd2), the position coordinate of the measurement point P projected on the observation object 42 is (Xa, Yb), and each photographing element 24 of the measurement point P is displayed. The position coordinates of the upper image point are (Xp1, Yp1) and (Xp2, Yp2), and Yd1 = −Yd2.

  Here, the coordinates of the intersection of a straight line connecting the center of the photographic lens 22 in each CCD camera 20 and the position of the image point on the photographic element 24 of the measurement point P are the measurement points P included in the XY plane on the observation target 42. Position coordinates. The two-dimensional position coordinate of the measurement point P is

で表される。

It is represented by

  Similarly, by translating the XY plane in the Z-axis direction, the two-dimensional position coordinates of the measurement point P at the moved position can be obtained, so the Z-coordinate represented by the moved Z-axis direction and the above-mentioned By using the two-dimensional position coordinates obtained in this way, the three-dimensional position coordinates of the measurement point P are obtained. The obtained three-dimensional position coordinates are stored in a memory provided in the control unit.

  Here, the image formed on the image plane 24A of the imaging element 24 when the distance from the CCD camera to the observation target is changed by a predetermined distance (for example, 25 mm to 250 mm) according to the arrangement position of the projection pattern plate. Consider the moving range of points.

  On the XY plane, the coordinates of the center of the projection lens are (0, 0), the coordinates of the center of each photographing lens 22 are (0, 3 mm), and (0, −3 mm), and the projection lens system 26 and each photographing lens 22. The focal length is 2.56 mm, the angle of view in the Y-axis direction (horizontal method) is ± 30 °, and the angle of view in the Z-axis direction (vertical direction) is ± 22.5 °. The horizontal size is 2.56 mm, the vertical size is 1.92 mm, the number of pixels of the image sensor is 640 pixels in the horizontal direction, 480 pixels in the vertical direction, and each pixel size is 4 × 4 μm.

  Under these conditions, when the distance Xa from each photographic lens to the observation target is changed from −25 mm to −250 mm, the point-like transmission part 37B of the projection pattern plate in FIG. 8 is located at the origin (Yp0). = 0.00mm), when the point transmission part 37B of the projection pattern plate of FIG. 9 is located at Yp0 = 0.64 mm, the point transmission part 37B of the projection pattern plate of FIG. In each case of 28 mm, the position Yp1 of the image point on one imaging element 24 changes as shown in the graphs of FIGS. 8 to 10A, and the position of the image point on the other imaging element 24. Yp2 changes as shown in the graphs of FIGS.

  From the above, when attention is paid to one measurement point P on the observation object, even if the distance Xa from each imaging lens to the observation object changes, the image point of the measurement point P on the image plane of each imaging element is changed. The positions Yp1 and Yp2 move within a certain range.

  Therefore, if each measurement point projected on the observation target is modulated within a range on the observation target corresponding to the range on the image plane (a predetermined range where one projection pattern is arranged), each measurement is performed. A point can be easily associated between the captured images of the CCD cameras, and the three-dimensional shape of the observation target can be easily measured.

  For this reason, in an imaging device having an image plane size of 1.92 mm × 2.56 mm, if each measurement point projected on the observation target is modulated within a range of 0.27648 mm × 0.276648 mm on the image plane, Thus, the three-dimensional shape of the observation target can be easily measured. Assuming that the number of effective pixels of a general CCD camera is 480 pixels × 640 pixels as described above, each point-like projection light projected on the observation object within each range of 80 pixels × 80 pixels on the image plane is obtained. What is necessary is just to modulate. For example, if one measurement point is projected onto the observation target per 4 pixels × 4 pixels on the image plane, 20 × 20 measurement points are required within each predetermined range on the observation target. It is easy to modulate the measurement points so that they can be distinguished into 400 types. In addition, it is more preferable that the dot-like projection light projected on the observation target has a size corresponding to 1 pixel × 1 pixel or more and 3 pixels × 3 pixels or less on the image plane.

  In the endoscope 10 having the above configuration, when the endoscope 10 is operated, the distal end 12A side of the insertion portion 12 is inserted into the observation target 42 side and directed toward the observation target 42, and when the switch 46 is pressed, the control unit The light source 34 is turned on by 38. The light emitted from the light source 34 is projected from the projection lens system 26 onto the surface on the insertion unit 12 side of the observation object 42 via the condenser lens 32 and the projection pattern plate 36, and a pattern image corresponding to the projection pattern is formed. Projected.

  Further, each CCD camera 20 is operated by the control unit 38, whereby the observation target 42 and the pattern image on the observation target 42 are taken by each CCD camera 20.

  The control unit 38 calculates the three-dimensional position coordinates of the measurement point according to the above equation (1). At this time, since each measurement point can be easily associated by modulation, the calculation is simple. On the other hand, the control unit 38 uses the center of the cross-shaped projection light 44 of the captured image of each CCD camera 20 as a feature point, and sequentially sets the three-dimensional position coordinates of measurement points other than the feature point in the captured image based on the feature point. Calculation is also easy because the number of measurement points is small. A plurality of feature points may be provided. Thereby, the three-dimensional position coordinate of each measurement point on the observation object 42 is obtained, and the three-dimensional shape of the observation object 42 can be measured without contact.

  The monitor 48 displays a distribution of points corresponding to the three-dimensional position coordinates based on the three-dimensional position coordinates of each measurement point calculated by the control unit 38. Thereby, the three-dimensional shape of the observation object 42 can be grasped visually.

  In the present embodiment, since a two-dimensional pattern image is projected onto the observation target, the three-dimensional shape of the observation target can be measured without scanning the projection light projected onto the observation target. For this reason, the three-dimensional shape of the observation target can be measured at high speed, and the three-dimensional shape of the observation target can be accurately measured even when the observation target moves or deforms.

  Furthermore, if the position coordinates of the measurement points on the observation target are detected from the center of gravity or the peak position of the projected measurement points, it is possible to measure fine position coordinates that are more than the number of pixels of the imaging element. For this reason, even if the base line length (distance between photographing lenses) in triangulation cannot be increased, the three-dimensional shape of the observation target can be measured with high accuracy.

  Furthermore, since the colors of the measurement points on the observation target are different, the measurement points on the observation target can be easily matched between the captured images of the CCD cameras, and the three-dimensional position coordinates of the measurement points can be easily set. It can be calculated. In addition, since the brightness at each measurement point is constant, it is necessary to perform additional calculation processing such as increasing the dynamic range of the CCD camera or normalizing the brightness at each measurement point when calculating the position coordinates. Will also disappear.

  As described above, particularly when this embodiment is used as a medical endoscope, the three-dimensional shape (surface shape, unevenness, texture) and size (spread) of a lesion such as stomach cancer or colon cancer However, it can provide important clues for diagnosis and treatment for diseases that have important implications for diagnosis and subsequent treatment strategies.

  In the above embodiment, the example in which the projection pattern plate is provided between the condenser lens and the projection lens system has been described. However, the projection pattern plate may be provided between the light source and the condenser lens system. .

[Second Embodiment]
FIG. 7 is a sectional view showing the internal configuration of the endoscope 50 according to the second embodiment of the present invention. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The endoscope 50 according to the present embodiment includes an insertion unit 12 and a processing unit 14. The endoscope 50 is provided with two imaging devices 52 and a projection device 54 that projects a pattern having a plurality of measurement points P onto an observation target.

  Each photographing device 52 has a photographing lens 22 arranged at a predetermined interval in the distal end 12A of the insertion portion 12, and a plurality of optical fibers are bundled on the light incident side of each photographing lens 22. The emission end 56A of the image fiber 56 inserted into the insertion portion 12 is disposed so as to face each other.

  Two CCD cameras 58 having an imaging lens 60 and a photographing element 24 are arranged in the processing unit 14. The imaging lens 60 faces the base end 56 </ b> B side of the image fiber 56, and the imaging element 24 is disposed at the image imaging position of the imaging lens 60.

  The projection device 54 includes a projection lens system 26 disposed at a position different from each photographing lens 22 in the distal end 12A of the insertion portion 12. On the light incident side of the projection lens system 26, the output end 62 </ b> A of the image fiber 62 inserted into the insertion portion 12 is arranged so as to face.

  An imaging lens 64 is disposed in the processing unit 14 so as to face the incident end 62 </ b> B of the image fiber 62. A condenser lens 32 is disposed on the light incident side of the imaging lens 64, and a light source 34 is disposed on the light incident side of the condenser lens 32. Between the imaging lens 64 and the condenser lens 32, the projection pattern plate 36 described in the first embodiment is arranged.

  In the processing unit 14, a control unit 38 is provided which is electrically connected to each of the imaging elements 24 and the light source 34 and to which a switch 46 and a monitor 48 are connected.

  In the endoscope 50 having the above configuration, when the endoscope 50 is operated, the distal end 12A side of the insertion portion 12 is inserted into the observation object 42 side and directed toward the observation object 42, and the switch 46 is pressed, the light source 34 Lights up. The light emitted from the light source 34 is irradiated from the projection lens system 26 onto the surface of the observation object 42 on the insertion portion 12 side via the condenser lens 32, the projection pattern plate 36, the imaging lens 64, and the image fiber 62. A pattern image is projected.

  Further, the observation object 42 and a pattern image on the observation object 42 are taken by each CCD camera 58.

  Since each image fiber only transmits an image, it is equivalent to the case where each CCD camera 58 is moved so that the imaging lens 60 coincides with the position of the photographing lens 22, and therefore the first embodiment. Similarly, the three-dimensional position coordinates can be calculated according to the above equation (1).

  Therefore, the endoscope according to the present embodiment can achieve the same effects as those described in the first embodiment.

  Furthermore, in this embodiment, since the light source and the projection pattern plate are provided outside the insertion portion, the light source and the projection pattern plate can be easily replaced manually, and the projection light projected onto the observation target The pattern and modulation method can be easily selected according to the purpose.

  In this embodiment, the projection pattern plate is provided between the imaging lens and the condenser lens. However, the projection pattern plate may be provided between the light source and the condenser lens.

In each of the above embodiments, an example in which two imaging devices are provided has been described. However, three or more imaging devices may be provided. In this case, if the number of imaging devices is n, _n C ₂ solutions of three-dimensional position coordinates are obtained for one measurement point. For this reason, when three or more imaging devices are provided, the average value or optimum value of the solution of the three-dimensional position coordinates can be obtained, and the three-dimensional position coordinates are increased as the number of imaging devices is increased. The calculation can be performed with high accuracy, and the three-dimensional shape of the observation target can be measured with higher accuracy.

  Furthermore, in each of the above embodiments, a predetermined number of feature points are provided in the captured image, and the three-dimensional position coordinates of measurement points other than the feature points are sequentially calculated. However, measurement is performed when the number of measurement points is small. You may make it calculate the three-dimensional position coordinate of a point simultaneously. As a result, the three-dimensional shape of the observation target can be measured at a higher speed.

  In each of the above-described embodiments, the example in which the projection light is spectrally modulated has been described. However, the intensity modulation that changes the brightness of the projection light, or the shape of the projection light is changed by changing the beam diameter or the beam shape. Shape modulation to be performed may be performed, or modulation in which two or more of spectrum modulation, intensity modulation, and shape modulation are combined may be performed.

  Furthermore, in each of the above-described embodiments, the example in which the color of light transmitted through each transmission portion of the projection pattern plate is changed has been described. However, the projection pattern plate is a perforated metal in which a through hole is formed as a transmission portion. A transparent, transparent part is formed in a transparent pattern for each specific area by depositing a metal vapor deposition film or opaque ink on a base plate such as a plate, a perforated opaque plastic plate, or a colorless transparent glass plate or a colorless transparent plastic plate. You may comprise with the projected pattern board made. In this case, for example, by providing a plurality of light sources, the spectrum-modulated or intensity-modulated light is emitted from the light sources to each of the plurality of through holes or each of the plurality of colorless and transparent transmitting portions.

  Further, in each of the above embodiments, the cross-shaped transmissive portion and the point-shaped transmissive portion are formed on the projection pattern plate, but the transmissive pattern of the projection pattern plate includes the point-shaped transmissive portion, the linear transmissive portion, the arc, It may be configured by any one of curved transmission parts such as a circle, or may be configured by combining two or more thereof.

  Furthermore, in each of the above-described embodiments, an example in which a pattern image is projected by a projection pattern plate has been described. However, a pattern image may be projected using a holographic lens without using a projection pattern plate, and a plurality of pattern images may be projected. An optical fiber bundle in which the emission end faces of the optical fibers are arranged in a projection pattern and bundled may be used.

It is sectional drawing which shows the internal structure of the endoscope which concerns on the 1st Embodiment of this invention. It is sectional drawing which shows the structure which projects projection light on the observation object in the endoscope which concerns on the 1st Embodiment of this invention. It is a front view which shows a part of projection pattern board in the endoscope which concerns on the 1st Embodiment of this invention. It is a front view which shows the transmission pattern of the projection pattern board in the endoscope which concerns on the 1st Embodiment of this invention. It is a table | surface which shows the condition which carries out the spectrum modulation | alteration of each point-like projection light within the predetermined range on an observation object in the endoscope which concerns on the 1st Embodiment of this invention. It is sectional drawing for demonstrating the method to calculate the position coordinate of the projection light on an observation object in the endoscope of the Example of this invention. It is sectional drawing which shows the internal structure of the endoscope which concerns on the 2nd Embodiment of this invention. In the endoscope which concerns on the 1st Embodiment of this invention, when Yp0 = 0.00mm, it is a graph at the time of changing Xa from -25mm to -250mm, (A) is in this case Is a graph showing the change in Yp1, and (B) is a graph showing the change in Yp2 at this time. In the endoscope which concerns on the 1st Embodiment of this invention, when Yp0 = 0.64mm, it is a graph at the time of changing Xa from -25mm to -250mm, (A) is in this case Is a graph showing the change in Yp1, and (B) is a graph showing the change in Yp2 at this time. In the endoscope which concerns on the 1st Embodiment of this invention, when Yp0 = 1.28mm, it is a graph at the time of changing Xa from -25mm to -250mm, (A) is in this case Is a graph showing the change in Yp1, and (B) is a graph showing the change in Yp2 at this time.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Endoscope 12 Insertion part 16 Imaging device 18 Projection apparatus 38 Control part 42 Observation object 48 Monitor 50 Endoscope 52 Imaging apparatus 54 Projection apparatus P Measurement point

Claims (4)

Projection means for projecting a pattern image having a plurality of measurement points onto an observation target;
A plurality of photographing means arranged at predetermined intervals so as to photograph the pattern image projected on the observation object from different positions;
Based on the images photographed by each of the photographing means, computing means for computing the position coordinates of each of the measurement points;
Including endoscope.   The endoscope according to claim 1, wherein projection modes of the measurement points projected onto the observation target are different from each other so that the measurement points can be distinguished from each other.   The endoscope according to claim 2, wherein each of the measurement points is formed by irradiating light having a constant light amount and a different wavelength or spectrum.   The endoscope according to any one of claims 1 to 3, further comprising display means for displaying a distribution of points corresponding to the position coordinates based on the calculated position coordinates.

Images