JPH04158205A - Endoscope device for measuring shape - Google Patents

Abstract

PURPOSE:To enable easy and precise measurement of a shape by a method wherein at least two linear pattern projection lights intersecting each other are applied in time division. CONSTITUTION:An endoscope 1 is fitted, at the fore end part 12, with a diffraction grating 13 prepared by joining one-dimensional fiber diffraction gratings 13a and 13b in parallel so that they are perpendicular to each other. The grating 13 intercepts laser lights 14a and 14b entering through the scope 1, at a prescribed interval and alternately, and pattern lights obtained by the gratings 13a and 13b respectively are projected onto a subject alternately. An image pickup element picks up an image of the subject synchronously with periods of changeover of the laser lights 14a and 14b. Thereby cross-shaped pattern lights 5a and 5b are separated from each other and images of the pattern lights 5a and 5b projected on the subject are presented on a screen alternately. then, the positional coordinates of the subject at each measuring point on the pattern lights are determined for each of these images, and the shape of the subject is measured by putting them in a composite. According to this constitution, the shape of the subject can be measured precisely by using the two pattern lights 5a and 5b.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a shape endoscope device that accurately measures the shape of a subject.

(Prior Art) Generally, in a shape measuring endoscope, the shape of the subject is measured by emitting a laser light pattern onto the subject from the tip of the endoscope and detecting the reflected light with an image sensor.

FIG. 4 is a configuration diagram of such a shape measuring endoscope device. When a laser beam pattern 3 is emitted from a position slightly away from the center of the distal end surface 2 of the endoscope 1, A linear pattern of light 5 is projected onto the object 4. Then, this pattern light 5 is detected by the imaging section 5, and for example, the fifth
As shown in the figure, the protrusion 4 a s of the object 4 and the patterned light 5 are displayed on the screen 6 . Then, the shape of the protrusion 5a is measured by an image processing device (not shown).

The measurement principle at this time will be explained based on FIG. 6.

In the figure, the emission angle of the laser beam pattern 3 is θ1,
If the detection angle of the patterned light 5 in the imaging section 7 is θ2, and the distance between the emission position of the laser beam pattern 3 and the center position of the imaging section 7 is the parallax P, then the distance from the tip surface 2 to the patterned light projection point is 2. is expressed by the following equation (1).

Ze −P@ / (tanθ, + tan, )
・(1) Also, this distance 2. are two coordinates, and the plane perpendicular to the plane of the paper in FIG. 5 is the x-y plane. 2) It can be obtained using equation (3).

X, −Z, ・tan θX
-12) Yp-Z, -tanθY-(3) However, θ8 and θ7 are the angles in the X-axis direction and the y-axis direction at which the pattern light 5 is detected, respectively.

In this way, the measurement point position coordinates (X, , Y, , Z,) on the patterned light 5 are determined by equations (1) to (3), and the shape of the object 4 is measured.

However, in such a method, since only one pattern light 5 is projected, the shape of the projection 4a shown in FIG. 5 cannot be accurately measured. Therefore, conventionally, two pattern lights 5a and 5b are projected in a cross shape as shown in FIG.
By determining the position coordinates of the object, the shape can be measured with high precision.

(Problem to be Solved by the Invention) However, when the two pattern lights 5a and 5b are projected at the same time, it is difficult to detect the reflected light and determine whether the reflected light is due to one of the pattern lights during recognition. Sometimes there isn't. In addition, it is not possible to process only the portion where the two <turn beams 5a and 5b intersect, and there is a drawback that smooth shape measurement cannot be performed.

This invention was made in order to solve such conventional problems, and its purpose is to provide a shape measuring endoscope that can easily and accurately measure shapes. .

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the present invention projects pattern projection light onto a subject from the tip of an endoscope, detects this reflected light using an image sensor, and detects the shape of the subject. In the shape measuring endoscope device for measuring, the pattern projection light is in the form of at least two intersecting lines, and each projection light is irradiated in a time-division manner.

(Function) With the configuration as described above, one of the at least two intersecting linear pattern projection lights is projected onto the subject while being switched at a predetermined time interval. Then, images on which each pattern projection light is projected are projected in a time-division manner, and the position coordinates of each measurement point on the pattern projection light projected on each image are determined. After that, the shape of the subject is measured by combining the images projected by each pattern of projected light.

Therefore, the shape of the object can be measured with high accuracy without erroneously recognizing the pattern light.

(Example) FIG. 1 is a perspective view showing the appearance of an endoscope l and a laser light source 11 of a shape measuring endoscope apparatus to which the present invention is applied. In the figure, a laser beam emitted from a laser light source 11 is guided to a distal end portion 12 via an optical fiber (not shown) disposed inside a scope 1.

FIG. 2 is a schematic diagram of the diffraction grating 13 attached to the tip portion 12. As shown in the figure, the diffraction grating 13 includes a one-dimensional fiber grating 13a that diffracts the laser beam in the vertical direction, and a one-dimensional fiber grating 13b that diffracts the laser beam in the horizontal direction.
and are connected in parallel so that they are perpendicular to each other. Laser beams 14a1 and 14b emitted from the laser light source 11 are incident on each of the diffraction gratings 13a and 13b. (see), a perpendicular cross-shaped pattern of light 5 is obtained.

In this embodiment, the laser beams 14a and 14b incident on each of the diffraction gratings 13a and 13b are alternately blocked at predetermined time intervals,
Patterned light from each of the diffraction gratings 13a and 13b is alternately projected onto the subject. This can be easily achieved using a chopper or the like. Then, in the imaging section 7 shown in FIG. 4, the subject is photographed in synchronization with the switching cycle of the laser beams 14a and 14b.

As a result, the cross-shaped patterned lights 5a and 5b are separated, and a screen in which the patterned lights 5a and 5b are projected onto the subject is displayed on the photographed screen, as shown in FIGS. 3(A) and 3(B). are displayed alternately. And each pattern light 58
For each image in which % 5b is projected, the position coordinates of the subject at each measurement point on the patterned light are determined, and these are combined to measure the shape of the subject. In this way, the shape of the subject is
Accurate measurement can be performed using the book pattern lights 5a and 5b.

In this way, in this embodiment, the cross-shaped pattern lights 5a and 5b are alternately switched and projected at predetermined time intervals, and the imaging unit 7 photographs the subject in synchronization with the time intervals. . The positional coordinates of the subject are determined independently based on the images of the patterned lights 5a and 5b, and the shape of the subject is measured by combining the coordinates.

Therefore, it becomes possible to accurately recognize the pattern light 58% 5b, and the accuracy of shape measurement improves.

Although this embodiment shows an example in which two intersecting pattern lights are projected, it goes without saying that the present invention is not limited to this and can be applied to a case in which three or more pattern lights are projected.

〔Effect of the invention〕

As described above, in the present invention, at least two linear pattern projection lights are irradiated in a time-sharing manner, and a subject to which each pattern projection light is independently irradiated is projected. The shape of the subject is then measured based on each captured image. Therefore, problems such as not being able to recognize which pattern projection light is used or not being able to process the part where the projection light intersects when the pattern projection light is irradiated at the same time are eliminated, and it is possible to easily and accurately form shapes. This has the effect of making measurement possible.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing the appearance of an endoscope and a laser light source to which the present invention is applied, Fig. 2 is a schematic diagram showing the configuration of a diffraction grating, and Fig. 3 is an image projected by the processing of the present invention. A diagram showing an example of a screen, Figures 4 and 6 are explanatory diagrams showing the principle of shape measurement, Figure 5 is a diagram showing a photographed image when one pattern light is projected, and Figure 7 is a diagram showing two patterns. FIG. 3 is a diagram showing a photographed image obtained by projecting intersecting pattern light. 1... Endoscope scope 5... Pattern light 7...
・Imaging unit 11...Laser light source 13...
Diffraction gratings 14a, 14b--laser light

Claims (1)

[Scope of Claims] A shape measuring endoscope device that projects pattern projection light onto a subject from a distal end of an endoscope scope, and measures the shape of the subject by detecting the reflected light with an image sensor, comprising: is at least two intersecting lines, and each projection light beam is emitted in a time-sharing manner.