JP7594735B2 - Triangulation Displacement Sensor - Google Patents

Description

The present invention relates to a triangulation type displacement sensor.

A triangulation type displacement sensor using a Scheimpflug optical system is known. For example, according to Patent Document 1, the focal position of the detection light projected from the light source is adjusted so that the size of the image on the light receiving surface of the light receiving element is constant regardless of the distance to the measurement object.

JP 2012-78152 A

In a triangulation displacement sensor, the measurement value is averaged within the spot of light irradiated on the object to be measured. In other words, even if the surface of the object to be measured is somewhat rough, the effect of the unevenness can be averaged out by making the spot larger, thereby reducing measurement errors. However, if the spot length in the direction corresponding to the baseline direction of the light receiving element is increased, the half-width of the received light waveform increases, reducing the measurement accuracy of the distance measurement. Therefore, it is considered that by not increasing the spot length in the baseline direction, but increasing the spot length in the line direction, which is the direction perpendicular to the baseline direction, it is possible to reduce measurement errors caused by rough surfaces while ensuring the measurement accuracy of the distance measurement.

From this perspective, detection light that takes the shape of, for example, an elliptical spot when irradiated onto the measurement object is used. In this case, if a conventional Scheimpflug optical system is used, the size of the received light image formed on the surface of the light receiving element changes significantly depending on the distance to the measurement object, and depending on the distance to the measurement object, the received light image may extend beyond the light receiving area of the pixel in the line direction. If an extending area exists in the received light image, the averaging effect on unevenness is reduced, leading to increased measurement errors. On the other hand, if the light receiving element is enlarged so that the received light image does not extend beyond the area, it will result in an increase in the size of the device and increased manufacturing costs.

The present invention was made to solve these problems, and aims to provide a triangulation type displacement sensor that can maintain a constant level of averaging effect in the line direction for unevenness on the surface of the object being measured over the measurable range, even when a small light receiving element is used.

In one aspect of the present invention, the triangulation displacement sensor includes a light-projecting module that projects detection light that forms a spot shape having a long side and a short side when irradiated onto a measurement object, an optical module that collects the detection light reflected by the measurement object, and a light-receiving element that outputs a detection signal according to the arrival position of the detection light collected by the optical module such that a plurality of rectangular light-receiving areas are arranged along the short side direction of the rectangle and the long side direction of the spot shape is aligned with the long side direction of the light-receiving area, and the optical module includes a magnification adjustment lens whose imaging magnification in the short side direction is greater than that in the long side direction.

This configuration makes it possible to prevent the spot image on the light receiving surface of the light receiving element from going beyond the light receiving area of the pixel in the line direction. In other words, regardless of where the measurement object is located within the measurable range, it is possible to enjoy the effect of averaging the unevenness of the measurement object surface in the line direction. In other words, when measuring distance while moving the displacement sensor in parallel to a measurement object that exists at the same distance within the measurable range, the measurement results are less likely to vary, and high movement resolution can be achieved.

In the above triangulation type displacement sensor, the optical module may be configured to include a convex lens and a magnification adjustment lens. It may also be configured to include multiple magnification adjustment lenses. By configuring it in this way, the principal point position of the optical module can be moved closer to the light receiving element, so that peripheral blurring can be suppressed even if it is not in the Scheimpflug optical system.

In the above triangulation distance measuring displacement sensor, the magnification adjustment lens may be selected from a toroidal lens and a cylindrical lens. By using these lenses, it is easy to realize an optical design that adjusts the imaging magnification in the short side direction and the imaging magnification in the long side direction, respectively.

In the above triangulation type displacement sensor, the light-projecting module may project detection light so that the spot shape becomes larger the more distant the measurement object is, and the optical module may be configured to focus detection light so that the more distant the measurement object is, the better the imaging state at the light-receiving element becomes for detection light reflected from the measurement object. With this configuration, even in long-distance measurements where good performance is difficult to achieve, the line-wise averaging effect for the unevenness of the measurement object surface can be obtained, just as in the case of short distances.

The present invention provides a triangulation displacement sensor that can maintain a constant level of averaging effect in the line direction for unevenness on the surface of the object being measured over the measurable range, even when using a small light receiving element.

FIG. 2 is a perspective view showing a state in which the triangulation type displacement sensor according to the present embodiment is used. 2 is a diagram for explaining the principle of triangulation, the arrangement of each element, the configuration of a light receiving element, etc. 1A and 1B are diagrams illustrating the relationship between a spot image and a light receiving element in the prior art. 5A and 5B are diagrams illustrating the relationship between a spot image and a light receiving element in the present embodiment. FIG. 2 is a schematic diagram illustrating a configuration of an optical module. 5 is a schematic diagram for explaining the imaging relationship of a spot image with respect to a measurement position on a workpiece when parallel light is projected; FIG. 11 is a schematic diagram for explaining the imaging relationship of a spot image with respect to a measurement position on a workpiece when diffuse light is projected. FIG.

The embodiments of the present invention will be described with reference to the attached drawings. In each drawing, the same reference numerals are used to denote the same or similar configurations. In addition, when there are multiple structures with the same or similar configurations in each drawing, in order to avoid complication, some of the structures may be given reference numerals and the same reference numerals may not be used for the others.

Figure 1 is a perspective view showing the displacement sensor 100 in use. The displacement sensor 100 according to this embodiment is an example of a triangulation type displacement sensor, and is installed and used, for example, on a factory production line. The displacement sensor 100 projects detection light L1 from a light-emitting element, such as a laser diode, toward a workpiece Wk, which is an object to be measured, and receives detection light L2 reflected by the workpiece Wk and returned, with a light-receiving element, such as a CMOS sensor. The light-receiving element receives the detection light L2 and outputs a detection signal according to the distance to the workpiece Wk.

The detection signal is transmitted to the amplifier unit via cable 112. The amplifier unit converts the received detection signal into a numerical value and displays it on the display unit, or outputs it to an external device such as a PLC or PC. Note that the displacement sensor 100 may incorporate the functions of the amplifier unit. In that case, the housing 111 is provided with a display unit that displays numerical values, etc., and a communication unit that communicates with external devices. Also, the x-axis, y-axis, and z-axis are defined as shown in the figure. In the subsequent drawings, the same coordinate axes as in Figure 1 are also shown to indicate the orientation of the components depicted in each drawing.

Figure 2 is a diagram explaining the principle of the triangulation method, the arrangement of each element, the configuration of the light receiving element 124, etc. Specifically, the upper diagram of Figure 2 (A) shows the optical path of the detection light (L1, L2) when the workpiece Wk is located near the center (Center) of the detection range, and the lower diagram of Figure 2 (A) shows the state of the spot image formed by the detection light L2 on the light receiving surface of the light receiving element 124 at that time. Similarly, the upper diagram of Figure 2 (B) shows the optical path of the detection light (L1, L2) when the workpiece Wk is located near the near end (Near) of the detection range, and the lower diagram of Figure 2 (B) shows the state of the spot image formed by the detection light L2 on the light receiving surface of the light receiving element 124 at that time. Similarly, the upper diagram in FIG. 2(C) shows the optical path of the detection light (L1, L2) when the workpiece Wk is located near the far end (Far) of the detection range, and the lower diagram in FIG. 2(C) shows the state of the spot image that the detection light L2 forms on the light receiving surface of the light receiving element 124 at that time. In addition to the above-mentioned x-axis, y-axis, and z-axis, the w-axis, which is the baseline direction of the light receiving element 124, is also shown. The w-axis is perpendicular to the y-axis.

As shown in the respective upper diagrams, a light-projecting element 121 and a light-projecting lens 122 as a light-projecting module, and an optical module 123 and a light-receiving element 124 as a light-receiving module are arranged and fixed inside the housing 111. The light-projecting module projects detection light L1 that has an elliptical spot shape when irradiated onto the workpiece Wk. In this embodiment, the laser light emitted from the light-projecting element 121, which is a laser diode, is adjusted by the light-projecting lens 122 to be parallel light, and is projected as detection light L1 toward the workpiece Wk. The light-projecting element 121 is provided with an elliptical aperture as an aperture stop.

The light-projecting element 121 is not limited to a laser diode that projects coherent light, and may be an element that projects incoherent light, such as an LED. In addition, the light-projecting module may omit the light-projecting lens 122 when the light-projecting element 121 itself emits parallel light. In addition, in this embodiment, a light-projecting module that forms an elliptical spot shape when the detection light L1 is irradiated onto the workpiece Wk is used, but it is not limited to an ellipse, and any light-projecting module that forms a spot shape having a long direction and a short direction may be used. For example, it may be rectangular. As will be described later in detail, the long direction (corresponding to the long axis direction in an ellipse) corresponds to the line direction that has an averaging effect on the unevenness of the surface of the object to be measured, and the short direction (corresponding to the short axis direction in an ellipse) corresponds to the baseline direction that affects the measurement accuracy of the distance measurement.

When the detection light L1 is reflected by the workpiece Wk, a part of it returns to the optical module 123 as the detection light L2. The optical module 123 collects the detection light L2 and guides it to the light receiving element 124. The optical module 123 includes one or more optical lenses. The specific configuration will be described later in detail. In this embodiment, the light receiving element 124 uses a line sensor, and the pixels that perform photoelectric conversion are arranged along the w axis. The light receiving module is arranged so as to satisfy the Scheimpflug condition with respect to the optical axis of the detection light L1. In other words, the spot formed on the workpiece Wk is well imaged on the light receiving surface of the light receiving element 124 regardless of the distance of the workpiece Wk from the displacement sensor 100 in the detection range. However, in this embodiment, the optical module 123 includes a lens that adjusts the magnification in the line direction as described later, and the line direction no longer satisfies the Scheimpflug condition, so the image on the light receiving element 124 is blurred in the line direction (y-axis direction).

As shown in the upper diagram of FIG. 2(A), when the workpiece Wk is located near the center of the detection range (Center), the detection light L2 reaches near the center of the light receiving surface along the w axis of the light receiving element 124. The lower diagram of FIG. 2(A) is a schematic diagram showing the light receiving surface of the light receiving element 124 observed from the optical module 123 side, and shows how the spot image Sp, which is an image of the spot formed on the workpiece Wk, is formed near the center in the w axis direction on the light receiving surface of the light receiving element 124.

The light receiving element 124 has a plurality of pixels 124a, each having a rectangular light receiving area, arranged along the short side direction of the rectangle, i.e., the w-axis direction. At this time, the long side direction of the rectangle is parallel to the y-axis direction. As shown in the figure, the spot image Sp is focused by the optical module 123 so that the long axis direction is along the long side direction of the light receiving area and the short axis direction is along the short side direction of the light receiving area. In other words, the light projecting module and the light receiving module are arranged in the housing 111 so that the spot image Sp and the pixels 124a have the above-mentioned relationship. Note that, as long as the arrangement satisfies this relationship, an optical element such as a mirror that refracts the light path may be added to the light projecting module or the light receiving module.

The light receiving element 124 outputs a detection signal according to the position of the spot image Sp. Specifically, since each pixel 124a outputs a voltage value according to the amount of light received, the output value array shows a distribution waveform according to the position of the spot image Sp. In the case of the lower diagram of FIG. 2(A), the center of the spot image Sp is present in a pixel near the center in the w-axis direction, so the light receiving element 124 outputs a detection signal whose peak value is that pixel. The amplifier unit receives such a detection signal and converts it into a distance to the workpiece Wk. In this embodiment, the w-axis direction, which is the arrangement direction (short side direction) of the pixels that form the distribution waveform, is referred to as the baseline direction, and the long side direction of the pixels is referred to as the line direction.

In such a triangulation method, even if the surface of the workpiece Wk is somewhat rough, the amount of reflection in the abnormal direction is relatively reduced according to the size of the spot irradiated thereon, and the reflected light is averaged as a whole. In other words, even if the surface of the workpiece Wk is somewhat rough, the effect of the unevenness can be averaged by making the spot larger, so that the measurement error can be reduced. However, if the spot length in the direction corresponding to the baseline direction of the light receiving element is increased, the half-width of the distribution waveform, which is the detection signal, becomes large, and the measurement accuracy of the distance measurement decreases. Therefore, in this embodiment, an ellipse with a short baseline direction and a long line direction is adopted as the spot shape. In addition, in response to this, a light receiving element 124 is adopted in which pixels having a rectangular light receiving area with the long side in the line direction and the short side in the baseline direction are arranged. Note that the shape of the light receiving area may be substantially rectangular, even if there are some chips around it due to the convenience of the wiring layer, etc. In this embodiment, a one-dimensional array of light receiving elements 124 is used in which a plurality of rectangular pixels as described above are arranged along the short side direction, but if each row along the line direction is treated as one group, a light receiving element in which a plurality of pixels are also arranged in the line direction can be used. For example, even if a light receiving element has square pixels arranged two-dimensionally, it can be said that the light receiving element has a plurality of rectangular light receiving regions arranged along the short side direction by adding up the output for each line.

As shown in the upper diagram of FIG. 2(B), when the workpiece Wk is displaced from near the center (Center) to near the near end (Near), the angle of incidence of the detection light L2 with respect to the optical module 123 changes. As a result, as shown in the lower diagram of FIG. 2(B), the spot image Sp is displaced in the positive direction of the w axis on the light receiving surface of the light receiving element 124. The light receiving element 124 outputs a detection signal whose peak value is the pixel where the center of the displaced spot image Sp is located. The amplifier unit receives this detection signal and converts it into the distance to the workpiece Wk.

As shown in the upper diagram of FIG. 2(C), when the workpiece Wk is displaced from near the center (Center) to near the far end (Far), the angle of incidence of the detection light L2 with respect to the optical module 123 changes. As a result, as shown in the lower diagram of FIG. 2(C), the spot image Sp is displaced in the negative direction of the w axis on the light receiving surface of the light receiving element 124. The light receiving element 124 outputs a detection signal whose peak value is the pixel where the center of the displaced spot image Sp is located. The amplifier unit receives this detection signal and converts it into the distance to the workpiece Wk.

Figure 3 is a diagram explaining the relationship between the spot image and the light receiving element in the conventional technology. In the conventional technology, for example, an aspheric lens was used as the optical module. When an aspheric lens is used, the imaging magnification in the line direction is equal to the imaging magnification in the base line direction. In the past, the spot image Sp-F at the far end was the smallest, and the spot image gradually became larger as the spot image moved toward the near point side. That is, the central spot image Sp-C was larger than the far end spot image Sp-F, and the near end spot image Sp-N was larger than the central spot image Sp-C. And, as shown in the figure, the central spot image Sp-C and the far end spot image Sp-F sometimes protruded from the light receiving area in the line direction. Since the light in the area protruding from the light receiving area is not photoelectrically converted, the effect of averaging the effect of unevenness on the surface of the measurement object is lost accordingly. That is, if the spot image protrudes from the light receiving area in the line direction, it can be said that measurement errors are likely to occur.

The optical module 123 of the displacement sensor 100 in this embodiment includes a magnification adjustment lens that acts to prevent the formed spot image from protruding too much in the line direction from the light receiving area, and has an imaging magnification in the baseline direction greater than the imaging magnification in the line direction. FIG. 4 is a diagram explaining the relationship between the spot image and the light receiving element 124 in this embodiment. As will be described in detail later, the optical module 123 is adjusted so that the spot image Sp-F on the far end side is in the best imaging state on the light receiving surface of the light receiving element 124. As shown in the figure, the spot image Sp-F on the far end side is adjusted so that it does not protrude too much in the line direction from the light receiving area.

Even if the spot image is displaced from the far end toward the center, the magnification adjustment lens reduces the amount by which the spot image extends beyond the light receiving area. However, because the optical module 123 includes a line-direction magnification adjustment lens, the Scheimpflug condition in the line direction is no longer satisfied, and so although the imaging state in the baseline direction on the light receiving element 124 is maintained, no image is formed on the light receiving element 124 in the line direction except for one focused point (assuming the Far light receiving position in this embodiment), and the image is blurred only in the line direction. Therefore, the central spot image Sp-C is slightly blurred at the edge in the line direction. In the figure, the approximate imaged portion is shown in black, and the blurred portion is shown with a crosshatched line.

The near-end spot image Sp-N has a larger blurred portion at the end in the line direction than the central spot image Sp-C, but the amount that it protrudes from the light-receiving area in the line direction is still significantly reduced compared to conventional technology. Therefore, regardless of where the spot image is located in the light-receiving area, the amount that it protrudes from the light-receiving area in the line direction is significantly reduced compared to conventional technology, so that the effect of averaging out the effects of unevenness on the surface of the object to be measured is maintained, and measurement errors can be reduced.

Figure 5 is a schematic diagram explaining the configuration of the optical module 123. Here, an example will be explained in which the optical module 123 is composed of two magnification adjustment lenses, a first light receiving lens 123a and a second light receiving lens 123b. Figure 5 (A) is a diagram showing the optical path of the light beam emitted from the center of the spot Sp on the workpiece Wk to the center line of the light receiving element 124, so that the arrival position in the base line direction of the light receiving element 124 can be seen. Figure 5 (B) is a diagram showing the optical path of the light beam emitted from the end of the long axis direction of the spot Sp on the workpiece Wk to the light receiving element 124, so that the arrival position in the line direction of the light receiving element 124 can be seen. Note that in both figures, the distance between elements is shown differently from the actual distance in order to make it easier to understand.

The imaging magnification in the baseline direction is m, and the imaging magnification in the line direction is m'. Let n be a positive real number, and let m'=m/n. Let the focal length of the first light receiving lens 123a in the baseline direction be _f0 , and the focal length of the second light receiving lens 123b be ∞. Let the focal length of the first light receiving lens 123a in the line direction be _f1 , and the focal length of the second light receiving lens 123b be _f2 . Let the distance from the spot Sp to the principal surface of the first light receiving lens 123a be a, and the distance from the principal surface of the first light receiving lens 123a to the light receiving surface of the light receiving element 124 be b. Let the distance between the principal surface of the first light receiving lens 123a and the principal surface of the second light receiving lens 123b be d, and let the effective radius in the line direction of both the first light receiving lens 123a and the second light receiving lens 123b be R. The major axis width of the spot Sp is _Lsp , and half of that is _h0 . The width in the line direction of the light-receiving area of the light-receiving element 124 is _LCM . Also, φ, ψ, ψ', b', b", c, _h1 , _h2 , _h3 , and _h4 are defined as shown in the figure.

Then, the following relation holds:

In such a relational expression, d, f', _f1 , and _f2 may be designed so that _h1 , _h2 , _h3 , and _h4 are within _LCM as much as possible. A combination of the first light receiving lens 123a and the second light receiving lens 123b that realizes such a design may be a toroidal lens and a cylindrical lens. In addition, both the first light receiving lens 123a and the second light receiving lens 123b may be toroidal lenses. In addition, the first light receiving lens 123a may be a convex lens that does not have a function of adjusting the magnification with _f0 = _f1 , and the second light receiving lens 123b may be a magnification adjustment lens. In this case, the second light receiving lens 123b may be a toroidal lens or a cylindrical lens. In addition, a third light receiving lens and a fourth light receiving lens may be added in addition to the first light receiving lens 123a and the second light receiving lens 123b to increase the degree of freedom of design.

FIG. 6 is a diagram for explaining the imaging relationship of the spot image with respect to the measurement position of the workpiece Wk when the light projection module projects parallel light. FIG. 6(A) shows the imaging relationship when the workpiece Wk is located near the far end (Far) of the detection range. FIG. 6(B) shows the imaging relationship when the workpiece Wk is located near the center (Center) of the detection range. FIG. 6(C) shows the imaging relationship when the workpiece Wk is located near the near end (Near) of the detection range. Both figures are similar to FIG. 5(B), and show the optical path of the light beam emitted from the end of the spot Sp on the workpiece Wk in the major axis direction to the light receiving element 124, so that the arrival position in the line direction of the light receiving element 124 can be seen. Here, since the light projection module projects parallel light, the width of the spot Sp in the major axis direction is L _Sp in both cases.

In this embodiment, when the workpiece Wk is located near the far end (Far) of the detection range, the spot image is adjusted so that it is best focused on the light receiving surface of the light receiving element 124. When adjusted in this way, when the workpiece Wk is located near the center (Center) of the detection range, the light beam emitted from the end of the long axis direction of the spot Sp is focused just before the light receiving surface of the light receiving element 124. Therefore, it is slightly diffused when it reaches the light receiving surface. In other words, as shown in Figure 4, the peripheral portion of the spot image is slightly blurred.

When the workpiece Wk is located near the near end of the detection range (Near), the light emitted from the end of the long axis direction of the spot Sp forms an image further in front of the light receiving surface of the light receiving element 124. Therefore, it reaches the light receiving surface more diffusely. That is, as shown in FIG. 4, the periphery of the spot image becomes even more blurred. And, in the state of FIG. 6(C), part of the blur extends beyond the light receiving area of the light receiving element 124. However, when the imaging state is adjusted based on the case where the workpiece Wk is located near the far end, the amount of blurring is reduced compared to when the adjustment is based on the center or near end, and the amount of protrusion from the light receiving area is also reduced.

As a modified example of this embodiment, a configuration for further suppressing the amount of protrusion from the light receiving area will be described. Figure 7 is a diagram for explaining the imaging relationship of the spot image with respect to the measurement position of the workpiece Wk when diffuse light is projected. Figure 7(A) shows the imaging relationship when the workpiece Wk is located near the far end (Far) of the detection range. Figure 7(B) shows the imaging relationship when the workpiece Wk is located near the center (Center) of the detection range. Figure 7(C) shows the imaging relationship when the workpiece Wk is located near the near end (Near) of the detection range.

As shown in each of the drawings, the width of the spot Sp in the major axis direction is different from that in the case of FIG. 6. That is, in this modified example, the light-projecting module projects the detection light L1 so that the spot shape expands as the light-projecting module irradiates the workpiece Wk at a greater distance. Specifically, the light-projecting lens 122 adjusts the laser light emitted from the light-projecting element 121 so that it is slightly diffused. The degree of diffusion is determined according to the detection range that is set.

In this modified example, the spot image is adjusted so that it is best focused on the light receiving surface of the light receiving element 124 when the workpiece Wk is located near the far end (Far) of the detection range. When adjusted in this way, when the workpiece Wk is located near the center (Center) of the detection range, the light beam emitted from the end of the long axis direction of the spot Sp is focused slightly in front of the light receiving surface of the light receiving element 124. Therefore, it is slightly diffused when it reaches the light receiving surface. However, since the width of the long axis direction of the spot Sp is shortened from L _Sp-F to L _Sp-C , the chief ray is closer to the optical axis than in the case of FIG. 6B, and the blurring of the peripheral part of the spot image is suppressed.

When the workpiece Wk is located near the near end of the detection range (Near), the light beam emitted from the end of the long axis direction of the spot Sp forms an image further in front of the light receiving surface of the light receiving element 124. Therefore, the light beam reaches the light receiving surface more diffusely. However, since the width of the long axis direction of the spot Sp is shortened from L _Sp-C to L _Sp-N , the principal ray is closer to the optical axis than in the case of FIG. 6(C), and the blurring of the peripheral part of the spot image is suppressed. By adjusting the detection light L1 in this way, the amount of the spot image protruding from the light receiving area can be further suppressed.

[Additional Notes]
a light projection module (121, 122) that projects detection light (L1) that has a spot shape having a longitudinal direction and a lateral direction when irradiated onto a measurement object (Wk);
an optical module (123) that collects the detection light (L2) reflected by the measurement object (Wk);
a light receiving element (124) that outputs a detection signal corresponding to a position where the detection light (L2) collected by the optical module (123) arrives, the light receiving element (124) including a plurality of rectangular light receiving regions (124a) arranged along a short side direction of the rectangle, the longitudinal direction of the spot shape being aligned with the long side direction of the light receiving region;
The optical module (123) is a triangulation type displacement sensor including magnification adjustment lenses (123a, 123b) whose imaging magnification in the short side direction is larger than that in the long side direction.

100...displacement sensor, 111...housing, 112...cable, 121...light-emitting element, 122...light-emitting lens, 123...optical module, 123a...first light-receiving lens, 123b...second light-receiving lens, 124...light-receiving element, 124a...pixel

Claims (5)

a light projection module that projects detection light that has a spot shape having a long direction and a short direction when irradiated onto a measurement object;
an optical module that collects the detection light reflected by the object to be measured;
a light receiving element configured to output a detection signal corresponding to a position where the detection light collected by the optical module reaches, the light receiving element including a plurality of rectangular light receiving regions arranged along a short side direction of the rectangle, the longitudinal direction of the spot shape being aligned with the long side direction of the light receiving region;
The optical module is a triangulation type displacement sensor including a magnification adjustment lens having an imaging magnification in the short side direction greater than an imaging magnification in the long side direction. The triangulation type displacement sensor according to claim 1, wherein the optical module includes a convex lens and the magnification adjustment lens. The triangulation type displacement sensor according to claim 1 or 2, wherein the optical module includes a plurality of the magnification adjustment lenses. The triangulation type displacement sensor according to any one of claims 1 to 3, wherein the magnification adjustment lens is selected from a toroidal lens and a cylindrical lens. the light projection module projects the detection light such that the spot shape becomes larger as the light is irradiated onto a measurement object that is farther away;
A triangulation type displacement sensor as described in any one of claims 1 to 4, wherein the optical module focuses the detection light so that the imaging state at the light receiving element is better for the detection light reflected from a measurement object that is farther away within a set detection range.

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