JPH02113217A - Measuring endoscope device - Google Patents

Abstract

PURPOSE:To represent the line of a linear pattern on an object uniformly and sharply and to increase the quantity of pattern light for projecting a linear pattern by inserting and arranging a slit which controls the width of an optical path perpendicular to a component of the linear pattern light. CONSTITUTION:An observation window 2 is formed in the flank of a scope tip part 1 and an image of the object which is lighted is picked up by a solid image pickup element 3 through the observation window 2; and this endoscope 4 of this sideward view structure is equipped with a pattern projection part 5. The pattern projection part 5 is constituted by inserting and arranging the slit 9 which controls the width of the optical path perpendicular to the line component of the linear pattern light on the optical path between a converging lens 7 which converges coherent laser light projected from an optical fiber 6 and a diffraction grating 8 which diffracts the converged light from the converging lens 7 to obtain the linear pattern light. Consequently, the linear pattern light on the object is represented uniformly and clearly and the quantity of the linear pattern light in the line direction is sufficiently secured.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a measurement endoscope device that can perform three-dimensional measurement using a pattern projection method, and in particular, to a measurement endoscope device that can perform three-dimensional measurement using a pattern projection method. This invention relates to improvements in the structure of a projection section.

(Prior art) Conventionally, in this type of measurement endoscope device, a laser beam focused by a focusing lens is diffracted by a diffraction grating, a diffraction pattern light is projected onto a subject, and a projected image of the diffraction pattern is transferred to a solid state. Based on the video signal obtained by imaging with the image carrier, an image processing means extracts pixels having a signal intensity equal to or higher than a predetermined value, and recognizes the order of diffraction at each extraction point according to the magnitude of brightness. A measurement endoscope apparatus has been proposed and put into practical use, which is capable of generating pattern extraction coordinates and measuring the surface shape of a subject, such as unevenness, using the pattern extraction coordinates.

In such measurement endoscope devices, a linear pattern is usually projected onto the subject as a diffraction pattern, but if the lines of the linear pattern are not uniformly and clearly displayed on the subject, the solid-state m-image element may The light reception situation of the pattern becomes uneven. In this case, the image processing means cannot correctly perform image analysis based on the video signal from the solid-state image pickup device, and the desired three-dimensional S1 measurement cannot be performed.

Therefore, by first reducing the diameter of the focusing lens or inserting a pinhole on the optical path between the focusing lens and the diffraction grating, a linear pattern is projected onto the subject. It has been proposed to represent lines evenly and clearly on a subject.

(Problem to be Solved by the Invention) However, as described above, when using a small-diameter focusing lens or using a pinhole, a linear pattern can be uniformly and clearly displayed on the subject, but on the other hand, The pattern light often becomes extremely dark, resulting in a pattern light reception situation that is lower than the light reception sensitivity of the solid-state image carrier, and the image processing means cannot correctly perform image analysis.

The present invention has been made in view of the above circumstances, and its purpose is to uniformly and clearly represent the lines of a linear pattern on a subject, and to use pattern light to project the linear pattern. An object of the present invention is to provide a measuring endoscope device that can dramatically increase the amount of light.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides a measurement endoscope device capable of performing three-dimensional measurement using a pattern projection method. A slit is provided on the optical path between the laser beam and the diffraction grating that diffracts and refracts the focused light to obtain the linear pattern light, for regulating the optical path width in the direction perpendicular to the component of the linear pattern light. The gist of the present invention is to include a pattern projection section which is inserted and arranged.

(Function) With the measurement endoscope device according to the present invention, when the line pattern light is projected from the diffraction grating onto the subject, the optical path width is regulated by the slit in the direction perpendicular to the line component of the line pattern light. Ru.

Therefore, the lines of the linear pattern on the subject are displayed evenly and clearly, and a sufficient amount of light in the line direction of the linear pattern is ensured. As a result, image analysis can be performed correctly based on the video signal obtained by capturing the projected pattern image on the subject using the solid-state image sensor.

(Embodiment) FIG. 1 is a configuration diagram schematically showing a scope distal end portion of an endoscope that constitutes a main part of a measuring endoscope apparatus according to an embodiment of the present invention.

Within the measurement of this one example? The JAma device has an observation window 2 on the side of the scope tip 1, and an endoscope 4 (see Fig. 2) that has a side view structure through which an object is imaged under illumination by a solid-state image sensor 3. ) is equipped with a pattern projection section 5.

The pattern imaging unit 5 includes a focusing lens 7 that focuses coherent laser light emitted from the optical fiber 6, and a diffraction grating 8 that diffracts the focused light from the focusing lens 7 to obtain line-shaped pattern light. A slit 9 is inserted on the optical path between the two to regulate the optical path width in the direction perpendicular to the line component of the line pattern light.

Further, as the focusing lens 7 of the pattern projection section 5, a plano-convex lens 7a formed of a meniscus lens, an aspherical surface, or a combination thereof as shown in FIG. 3, or a cylindrical lens 7b as shown in FIG. 4 may be used. can.

If such a pattern projection unit 5 is mounted on the endoscope 4, the pattern projection unit 5 from the diffraction grating 8 to the mirror 8a and the emission window 8
The slit 9 regulates the optical path width in the direction perpendicular to the line component of the line pattern light under the condition in which the line pattern light is projected onto the subject through the line pattern light.

Therefore, for example, when a line pattern is displayed on the subject as shown in Fig. 5, the amount of light is sharply regulated in the direction perpendicular to the line of the line pattern (Y direction in the figure). The lines of the pattern will be expressed evenly and clearly.

Further, since there is no light quantity regulation in the line direction of the line pattern (X direction in the figure), sufficient brightness is ensured.

Therefore, the projected image of the linear pattern incident on the observation window 2 becomes an electrical signal provided with information indicating the linear pattern with high precision in the solid-state image sensor 3, and as shown in FIG. It is sent to the processor 11. In this video processor 11, the solid-state image sensor 3
The electrical signal is converted to an NTSC signal and sent to the TV monitor 12.
Meanwhile, the luminance component of the NTSC signal is sent to the coordinate detection section 13. Therefore, the coordinate information on the surface of the subject can be obtained with high precision by the known analysis process in the coordinate detecting section 13. Based on this coordinate information, video processor 1
1, stereoscopic measurements such as the size and depth of the lesion are performed as desired, and the contents of this stereoscopic measurement can be displayed on the TV monitor 12 together with the subject image. .

The laser light source device 14 is driven and controlled using the video processor 11 as a control center, and the laser light emitted from the laser light source device is propagated to the scope tip 1 through the optical fiber 6.

[Effects of the Invention] As explained above, the measurement endoscope M device to which the present invention is applied regulates the optical path width only in the direction perpendicular to the line using a slit for the focused light from the focusing lens, and focuses the focused light. Since the bundle of light is guided to the diffraction grating, the line pattern projected onto the subject by the diffraction grating is uniform and clearly represented, and sufficient brightness in the line direction is ensured. As a result, according to the present invention, it is possible to perform stereoscopic measurement of a subject with high precision.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an outline of the main parts of a measuring endoscope device according to an embodiment of the present invention, FIG. 2 is a perspective view showing an outline of the external appearance of an endoscope, and FIGS. 5 is a schematic diagram showing an example of a line-shaped pattern, and FIG. 6 is a perspective view showing an outline of the configuration of main parts of other embodiments of the present invention. FIG. FIG. 2 is a block diagram showing a circuit configuration.

Claims (1)

[Claims] (1) In a measurement endoscope device that can perform three-dimensional measurement using a pattern projection method, a focusing lens that focuses a laser beam is attached to the tip of the scope of an endoscope, and the focused light from this focusing lens is A pattern projection section is provided, in which a slit for regulating the optical path width in a direction perpendicular to the component of the linear pattern light is inserted on the optical path between the diffraction grating and the diffraction grating for diffracting the linear pattern light. A measurement endoscope device characterized by: