JP6947065B2 - Limited reflective sensor - Google Patents

Description

The present invention relates to a sensor, in particular, irradiates an emitted light from a light emitting portion toward an object detection region through an outgoing light lens, and transmits reflected light from an object existing in the object detecting region through the reflected light lens. The present invention relates to a limited reflection type sensor that receives light at a light receiving unit.

Conventionally, as a sensor for detecting whether or not an object exists at a predetermined position, the detection area of the object is limited to emit light emitted from a light emitting unit, and the reflected light reflected by the object in the detection area is emitted. A limited reflection type sensor that receives light at the light receiving unit has been proposed (see, for example, Patent Document 1 and the like).

In such a limited reflection type sensor, the light emitting portion irradiates the detection region with the emitted light via the emitting light lens, and the light receiving portion receives the reflected light reflected by the object in the detecting region via the light receiving lens. Receive light. When the reflected light is incident on the light receiving unit, the light is converted into an electric signal by the light receiving unit, so that the presence of an object in the detection region can be detected by detecting the voltage change generated in the light receiving unit. Therefore, the detection region is limited to the range in which the light is emitted from the light emitting portion and the light can reach the light receiving portion. The setting range of such a detection region can be changed by the optical design of the outgoing light lens and the light receiving lens.

In the conventional limited reflection type sensor shown in Patent Document 1, each of the emission light lens and the light receiving lens is composed of a combination of an aspherical lens and a cylindrical lens. As a result, the cylindrical lens placed on the inside detects the short distance, and the aspherical lens placed on the outside detects the long distance, thereby expanding the detection range of the long distance while maintaining the detection range of the short distance. Can be done.

Japanese Unexamined Patent Publication No. 2015-81801

The conventional limited reflection type sensor described above is used, for example, to detect an approaching object and stop it at a fixed position, but it is desired that the object can be detected in a wider range. However, in the limited reflection type sensor of Patent Document 1, even if the curvature of the cylindrical lens is changed, it is difficult to detect an object at a shorter distance because the optical design becomes very difficult. In addition, in order to include a shorter distance in the detection area, it is necessary to increase the size of the lens and change the positions of the light emitting part and the light receiving part, which reduces the miniaturization of the limited reflection type sensor and the degree of freedom in design. There was a problem.

The present invention was devised to solve such a problem, and an object of the present invention is to provide a limited reflection type sensor capable of expanding the detection area on the short distance side while maintaining the long distance side range of the detection area. To provide.

In order to solve the above problems, the limited reflection type sensor of the present invention irradiates the light emitted from the light emitting unit toward the object detection area through the lens for the emitted light, and the reflected light from the object existing in the object detection area. This is a limited reflection type sensor that receives light from the light receiving portion via the reflected light lens. The emitted light lens and the reflected light lens are integrally formed with the flat plate portion, and the object detection region of the flat plate portion is formed. a first surface facing are substantially planar surfaces, wherein the second surface of the first surface and the opposite side is the separation groove is provided between the reflective light lens and the exit light lens, the exit the lens and the second surface side of the reflective light lens for Shako has a side toroidal lens area close to each of the separation grooves, the convex region remote from said isolation trenches, the emitting light lens When the range of the reflected light lens on the second surface side is the lens width W1 and the lens width W2, respectively, the toroidal lens region and the convex lens in the emitted light lens and the reflected light lens, respectively. The boundary position with the region is different from the center position of the lens width W1 and the lens width W2, and the light emitting portion or the light receiving portion is arranged at a position biased toward the convex lens region side with respect to the boundary position. It is characterized by being.

As a result, the convex lens region is used to irradiate and receive light on the long distance side, and the toroidal lens region is used to irradiate and receive light at a short distance, while maintaining the long distance side range of the detection region. , It is possible to expand the detection area on the short distance side. Further, since the boundary position between the toroidal lens region and the convex lens region is different from the center position of the lens, the degree of freedom in designing the light emitting portion and the light receiving portion is improved.

Further, in one embodiment of the present invention, the boundary position is biased toward the toroidal lens region side with respect to the center position.

Further, in one embodiment of the present invention, the boundary position is biased toward the convex lens region side with respect to the center position.

Further, in one embodiment of the present invention, the separation groove reaches the second surface side of the flat plate portion and is provided in a tapered shape .

According to the present invention, it is possible to provide a limited reflection type sensor capable of expanding the detection area on the short distance side while maintaining the long distance side range of the detection area.

It is a figure which shows typically the structure of the limited reflection type sensor 10 which concerns on Embodiment 1, FIG. 1 (a) is a schematic perspective view, and FIG. 1 (b) is a schematic cross-sectional view. It is a schematic cross-sectional view explaining the detailed structure of a lens 12. It is a figure which shows the result of having calculated the light emitted from the light emitting part 14a by the ray trajectory simulation, FIG. 3A shows an example using a conventional lens, and FIG. 3B is a convex lens part 121a of this invention. An example is shown in which a lens 12 having a concave lens portion 121b is used. It is the figure which superposed the result of the ray trajectory simulation of the light emitted from the light emitting part 14a by the limited reflection type sensor 10 and the light incident on the light receiving part 14b. This is the result of a ray trajectory simulation showing the irradiation of light from the inside of the light emitting portion 14a through the lens 12 and the light beam to the inside of the light receiving portion 14b. It is a figure explaining the light irradiation of the limited reflection type sensor 10 in detail, FIG. 6A shows light rays in the width direction in convex lens portions 121a, 122a, and FIG. 6B is the depth in convex lens portions 121a, 122a. The light rays in the direction are shown, FIG. 6C shows the light rays in the width direction at the concave lens portions 121b and 122b, and FIG. 6D shows the light rays in the depth direction at the concave lens portions 121b and 122b. It is a graph which shows the distance characteristic of the object detection using the limited reflection type sensor 10 of this embodiment. It is a schematic cross-sectional view which shows the structure of the limited reflection type sensor 20 which concerns on Embodiment 2. FIG. It is a schematic cross-sectional view explaining the detailed structure of a lens 22. It is the figure which superposed the light which irradiates from the light emitting part 14a by the limited reflection type sensor 20, and the result of the ray trajectory simulation of the region which can be detected by a light receiving part 14b.

<Embodiment 1>
Hereinafter, Embodiment 1 of the present invention will be described with reference to the drawings. 1A and 1B are views schematically showing the configuration of the limited reflection type sensor 10 according to the first embodiment, FIG. 1A is a schematic perspective view, and FIG. 1B is a schematic cross-sectional view. As shown in FIGS. 1A and 1B, the limited reflection type sensor 10 includes a housing portion 11, a lens 12, a mounting substrate 13, a light emitting portion 14a, and a light receiving portion 14b.

The housing portion 11 is a housing that constitutes the outer shape of the limited reflection sensor 10 and holds each portion, and FIG. 1 shows an example of a substantially rectangular parallelepiped box shape. The housing portion 11 is made of a material that does not transmit light having a wavelength longer than that of ultraviolet light, and for example, a resin colored in black can be used. Further, the housing portion 11 is provided with a mounting portion 11a, a lens accommodating portion 11b, a lens holding portion 11c, a light emitting accommodating portion 11d, and a light receiving accommodating portion 11e. The shape of the housing portion 11 is not limited to that shown in FIG.

The mounting portion 11a is a flat plate-shaped portion formed so as to project substantially horizontally from a pair of side walls of the housing portion 11, and a fastening hole is formed through the substantially center of each. The mounting portion 11a is a portion for positioning and fixing the limited reflection type sensor 10 to each part of a device or the like using the limited reflection type sensor 10. For example, a fastening hole is positioned in a screw portion provided in the device. It can be fixed with a screw or the like.

The lens accommodating portion 11b is a space surrounded by the side wall of the housing portion 11, and the lens 12 is arranged in the upper opening. As shown in FIG. 1B, the side wall around the lens accommodating portion 11b holds the peripheral edge portion of the lens 12 at the upper end thereof. Further, a part of the housing portion 11 forms a locking claw, which is fitted into a locking portion provided at a corresponding position of the lens 12 so that the light emitting portion 14a and the light receiving portion 14b are relative to the lens 12. The target position is decided and held.

The lens holding portion 11c is a substantially flat plate-shaped portion erected in the substantially center of the lens accommodating portion 11b, and separates the light emitting side and the light receiving side of the lens accommodating portion 11b, and the upper end portion thereof is on the lower surface of the lens 12. It is in contact. Since the lens accommodating portion 11b is divided into a light receiving side and a light emitting side by the lens holding portion 11c, it is possible to prevent light from directly reaching the light receiving portion 14b from the light emitting portion 14a through the lens accommodating portion 11b.

The light emitting accommodating portion 11d is a space provided in communication with the lens accommodating portion 11b, and further penetrates the bottom surface side (lower part in the drawing) of the housing portion 11. As shown in FIG. 1B, a light emitting unit 14a is arranged at a predetermined position in the light emitting accommodating unit 11d.

The light receiving accommodating portion 11e is a space provided in communication with the lens accommodating portion 11b, and further penetrates the bottom surface side (lower part in the drawing) of the housing portion 11. As shown in FIG. 1 (b), the light receiving unit 14b is arranged at a predetermined position in the light receiving accommodating unit 11e.

The lens 12 is made of a translucent material such as a resin, transmits light emitted from the light emitting unit 14a and takes out to the outside with a predetermined light distribution distribution, and transmits light incident from the outside to the light receiving unit 14b. It is an optical member that is incident on. The specific structure of the lens 12 will be described in detail later.

The mounting board 13 is a board on which a light emitting portion 14a and a light receiving portion 14b are mounted on one surface, and includes a wiring layer and a connector portion (not shown). The material constituting the mounting substrate 13 is not limited, and known materials such as a printed circuit board, a metal substrate, and a composite substrate of resin and metal can be used. As shown in FIG. 1B, the mounting substrate 13 is positioned and fixed from the bottom surface side of the housing portion 11, whereby the light emitting portion 14a and the light receiving portion 14b are accommodated in the light emitting accommodating portion 11d and the light receiving accommodating portion 11e, respectively. Will be done.

The light emitting unit 14a is a member in which electric power and a signal are transmitted from the outside of the limited reflection type sensor 10 via a connector unit (not shown), wiring, or the like, and emits light at a predetermined wavelength. The specific configuration of the light emitting unit 14a is not limited, and examples thereof include a light emitting diode (LED: Light Emitting Diode). The wavelength of the light emitted by the light emitting unit 14a may be included in the absorption band of the light receiving unit 14b, and for example, infrared light is used. Further, the light emitting unit 14a may be provided with an optical member such as a lens, and emits light from the LED chip with desired light distribution characteristics.

The light receiving unit 14b is a member that absorbs light having a predetermined wavelength, converts it into an electric signal, and sends a detection signal to the outside of the limited reflection type sensor 10 via a connector unit (not shown), wiring, or the like. The specific configuration of the light receiving unit 14b is not limited, but for example, a phototransistor can be used. The light receiving unit 14b includes the wavelength of the light emitted by the light emitting unit 14a in the absorption band. Further, the light receiving unit 14b may include an optical member such as a lens, and efficiently collects the incident light on a phototransistor for detection.

In the limited reflection type sensor 10 shown in FIGS. 1A and 1B, the power and signal supplied from the outside to the mounting substrate 13 are transmitted to the light emitting unit 14a, and the light emitted by the light emitting unit 14a is the light emitting accommodating unit 11d. Then, the light enters the lens 12 through the lens accommodating portion 11b, and the outside of the limited reflection sensor 10 is irradiated with light having a light distribution according to the curved surface of the lens 12. Further, when an object exists in the object detection region for detecting the object, the light emitted from the light emitting unit 14a is reflected in the direction of the limited reflection type sensor 10 and incident on the lens 12, and the lens accommodating unit 11b and It enters the light receiving portion 14b through the light receiving accommodating portion 11e. The light receiving unit 14b outputs a voltage corresponding to the intensity of the received light, and the voltage value is transmitted to the outside via the mounting substrate 13 as a signal for detecting an object.

FIG. 2 is a schematic cross-sectional view illustrating the detailed structure of the lens 12. In FIG. 2, the structure of the locking portion and the like is not shown in order to explain only the optical structure. As shown in FIG. 2, the lens 12 includes an emitted light lens 121, a reflected light lens 122, a flat plate portion 123, and a flange portion 124. The emitted light lens 121 and the reflected light lens 122 are formed at positions separated from each other by the separation groove 123a, but the lens 12 is integrally formed with the flat plate portion 123 and the flange portion 124. By integrally molding the emitted light lens 121 and the reflected light lens 122 as the lens 12, each of the emitted light lens 121 and the reflected light lens 122 emits light only by positioning the lens 12 on the housing portion 11. Positioning can be performed with respect to the portion 14a and the light receiving portion 14b, which simplifies the assembly process and improves the positioning accuracy. In the present embodiment, an example in which the emission light lens 121 and the reflected light lens 122 are integrally molded is shown, but the emission light lens 121 and the reflected light lens 122 may be completely separated from each other.

The flat plate portion 123 is a substantially flat plate-shaped portion that forms the upper end portion of the lens 12, and the emitted light lens 121 and the reflected light lens 122 are integrally formed on the lower surface side thereof. The upper surface of the flat plate portion 123 is a substantially flat entrance / exit surface 123b, and the entrance / exit surface 123b corresponds to the first surface in the present invention and is arranged so as to face the object detection region. Therefore, in the limited reflection type sensor 10, light emission to the object detection region and light reception from the object detection region are performed via the entrance / exit surface 123b of the flat plate portion 123. Since the lens 12 has the flat plate portion 123, the lens 12 does not protrude to the outside of the limited reflection type sensor 10, and space saving and adhesion of dirt can be suppressed.

The flange portion 124 is a portion thinner than the flat plate portion 123 and is formed so as to surround the outer periphery of the flat plate portion 123, and is fitted to the side wall of the housing portion 11 to position and fix the lens 12 to the housing portion 11. It is a part.

The separation groove 123a is a groove that separates the emission light lens 121 and the reflected light lens 122 and reaches the back surface of the flat plate portion 123, and the lens holding portion 11c is inserted as shown in FIG. This positions and holds the lens 12. Of the outgoing light lens 121 and the reflected light lens 122, the surface exposed by the separation groove 123a has a tapered shape as shown in FIG. 2, so that the lens holding portion 11c can be easily inserted and positioned.

The exit light lens 121 and the reflected light lens 122 are formed on the side opposite to the entrance / exit surface 123b as the second surface in the present invention, respectively, and the second surface has convex lens portions 121a and 122a and concave lens portions 121b and 122b, respectively. Have.

The convex lens portions 121a and 122a are provided in regions of the emitted light lens 121 and the reflected light lens 122 far from the separation groove 123a, respectively, and form a downwardly convex aspherical lens. Since the object detection region is located above the separation groove 123a, the convex lens portions 121a and 122a are located on sides far from the object detection region, respectively.

The concave lens portions 121b and 122b are provided in regions of the emitted light lens 121 and the reflected light lens 122 near the separation groove 123a, respectively, and form a concave toroidal lens region downward. Since the object detection region is located above the separation groove 123a, the concave lens portions 121b and 122b are located closer to the object detection region, respectively.

As shown in FIG. 2, the ranges of the emitted light lens 121 and the reflected light lens 122 that are in contact with the back surface of the flat plate portion 123 are defined as lens widths 121W and 122W, respectively. At this time, the boundary positions between the convex lens portions 121a and 122a and the concave lens portions 121b and 122b are biased toward the convex lens portions 121a and 122a, unlike the central positions of the lens widths 121W and 122W. By changing the boundary position between the concave lens portions 121b and 122b and the convex lens portions 121a and 122a constituting the toroidal lens region, the amount of light to be irradiated on the short-distance side and the amount of light to be irradiated on the long-distance side can be freely selected. Further, the positions of the light emitting portion 14a and the light receiving portion 14b are biased toward the convex lens portions 121a and 122a, which are outside the boundary positions between the convex lens portions 121a and 122a and the concave lens portions 121b and 122b.

FIG. 3 is a diagram showing the result of calculating the light emitted from the light emitting unit 14a by a ray trajectory simulation, FIG. 3 (a) shows an example using a conventional lens, and FIG. 3 (b) shows the present invention. An example is shown in which a lens 12 having a convex lens portion 121a and a concave lens portion 121b is used. Although FIGS. 3 (a) and 3 (b) show only the light emitted from the light emitting unit 14a, the description of the incident of light on the light receiving unit 14b will be omitted.

As shown in FIG. 3A, the light from the light emitting unit 14a is refracted by the entrance surface and the exit surface of the lens, and the light is irradiated in the direction of the object detection region. At this time, the light from the outer region of the lens is irradiated to a long distance, and the light from the inner region of the lens is irradiated to a short distance. As shown in FIG. 3B, also in the limited reflection type sensor 10 of the present embodiment, the outside of the lens 12 is the convex lens portion 121a, which irradiates light over a long distance, and the inside of the lens 12 is the concave lens portion 121b. It irradiates light at a short distance. Comparing FIG. 3A and FIG. 3B, by using the lens 12 of the present embodiment, the irradiation range of light from the concave lens portion 121b to a short distance is expanded, and the object detection region is set to a shorter distance. It can be seen that it can be expanded to. Since light can be emitted to the short-distance side as well, it is possible to detect an object located at a short distance regardless of the color of the object.

FIG. 4 is a diagram in which the results of light ray trajectory simulation of the light emitted from the light emitting unit 14a of the limited reflection sensor 10 and the light incident on the light receiving unit 14b are superimposed. In the limited reflection type sensor 10, the emission light lens 121 and the reflected light lens 122 of the lens 12 are formed, and the light emitting portion 14a and the light receiving portion 14b are also provided on the left and right, so that the light irradiation range and the light receiving range are provided. Is as shown in FIG. The region surrounded by a thick line in FIG. 4 is a region in which light is emitted from the light emitting unit 14a and light is incident on the light receiving unit 14b, and is an object detection region R. As shown in FIG. 3B, by using the lens 12 of the present embodiment, the light irradiation range is expanded to the short distance side, so that the object detection region R is also expanded to the short distance side. ..

FIG. 5 is a result of a ray trajectory simulation showing irradiation of light from the inside of the light emitting portion 14a through the lens 12 and light rays to the inside of the light receiving portion 14b. As shown in FIG. 5, the light from the light emitting unit 14a passes through the convex lens unit 121a and is focused at the cross point on the long distance side indicated by the black circle in the figure. As a result, the light intensity at the cross point can be improved, so that an object located at a short distance can be detected regardless of the color of the object.

6A and 6B are views for explaining the light irradiation of the limited reflection sensor 10 in detail, FIG. 6A shows light rays in the width direction of the convex lens portions 121a and 122a, and FIG. 6B shows the convex lens portions 121a, The light rays in the depth direction at 122a are shown, FIG. 6 (c) shows the light rays in the width direction at the concave lens portions 121b and 122b, and FIG. 6 (d) shows the light rays in the depth direction at the concave lens portions 121b and 122b. There is. Here, the width direction indicates the left-right direction of the limited reflection type sensor 10 shown in FIG. 1 (b), and the depth direction indicates a direction perpendicular to the paper surface of FIG. 1 (b).

As shown in FIGS. 6A and 6B, since the convex lens portions 121a and 122a are convex lenses of an aspherical lens, light is focused on the cross point on the long distance side in the width direction and the depth direction. .. As a result, the light intensity at the cross point can be improved, so that an object located at a short distance can be detected regardless of the color of the object.

On the other hand, as shown in FIGS. 6 (c) and 6 (d), since the concave lens portions 121b and 122 b are toroidal lenses, light is emitted to the short distance side in the width direction, but in the depth direction in FIG. 6 (d). Light is focused on the cross points indicated by black circles. Further, the cross points of the concave lens portions 121b and 122b in the depth direction are set closer to the cross points of the convex lens portions 121a and 122a. As a result, the light intensity at the cross point on the short distance side can be improved, so that an object located at a short distance can be detected.

FIG. 7 is a graph showing the distance characteristics of object detection using the limited reflection sensor 10 of the present embodiment. In the figure, the horizontal axis indicates the distance of the limited reflection sensor 10 from the surface of the lens 12, and the vertical axis indicates the intensity of the output detected by the light receiving unit 14b in a standardized manner. Further, the broken line in the figure shows a comparative example using a convex lens which is a conventional technique, and the solid line in the figure shows an example using the limited reflection type sensor 10 in the present embodiment.

As shown in FIG. 7, in the limited reflection type sensor 10 of the present embodiment, the light receiving output on the short distance side is significantly improved as compared with the case where the conventional convex lens is used. In addition, the light receiving output on the long distance side is also greatly improved. Therefore, in the limited reflection type sensor 10 of the present embodiment, even when an object exists at a short distance, the light emitted from the light emitting unit 14a to the object is strengthened, and the amount of light reflected by the object and incident on the light receiving unit 14b. Can be increased. As a result, the object detection accuracy at a short distance is improved, and an object located at a short distance can be detected regardless of the color of the object.

As described above, in the limited reflection type sensor 10 of the present embodiment, the emission light lens 121 and the reflected light lens 122 are provided with convex lens portions 121a and 122a and concave lens portions 121b and 122b, respectively. As a result, the long-distance side of the object detection region R can be enlarged by the convex lens portions 121a and 122a, and the short-distance side can be enlarged by the concave lens portions 121b and 122b to expand the detection range by the limited reflection sensor 10. .. Further, since the boundary position between the convex lens portions 121a and 122a and the concave lens portions 121b and 122b is different from the center position of the lens widths 121W and 122W, the degree of freedom in designing the light distribution on the short distance side and the long distance side is increased. improves. In particular, when the boundary position is biased to the outside of the center position, the regions of the concave lens portions 121b and 122b become wider than those of the convex lens portions 121a and 122a, and the light distribution to the short distance side is increased to detect on the short distance side. The accuracy can be further improved.

Further, since the light emitting portion 14a and the light receiving portion 14b are located outside the boundary positions between the convex lens portions 121a and 122a and the concave lens portions 121b and 122b, the degree of freedom in design is further improved and the arrangement to the short distance side is improved. It is possible to increase the amount of light. Further, it is possible to expand the detection area on the short distance side while maintaining the range on the long distance side of the detection area.

<Embodiment 2>
Next, Embodiment 2 of the present invention will be described with reference to the drawings. The description of the contents overlapping with the first embodiment will be omitted. FIG. 8 is a schematic cross-sectional view showing the configuration of the limited reflection type sensor 20 according to the second embodiment. As shown in FIG. 8, the limited reflection type sensor 20 includes a housing portion 11, a lens 22, a mounting substrate 13, a light emitting portion 14a, and a light receiving portion 14b. In the limited reflection type sensor 20 of the present embodiment, only the lens 22 is different from the limited reflection type sensor 10 of the first embodiment, and the other configurations are the same, only the lens 12 and the lens 22 are replaced.

FIG. 9 is a schematic cross-sectional view illustrating the detailed structure of the lens 22. As shown in FIG. 9, the lens 22 includes an emitted light lens 221, a reflected light lens 222, a flat plate portion 223, and a flange portion 224. The emitted light lens 221 and the reflected light lens 222 are formed at positions separated from each other by the separation groove 223a, but the lens 22 is integrally formed with the flat plate portion 223 and the flange portion 224.

The exit light lens 221 and the reflected light lens 222 are each formed on the opposite side to the entrance / exit surface 223b as the second surface in the present invention, and the second surface has convex lens portions 221a and 222a and concave lens portions 221b and 222b, respectively. Have.

As shown in FIG. 9, the ranges of the emitted light lens 221 and the reflected light lens 222 that are in contact with the back surface of the flat plate portion 123 are defined as lens widths 221W and 222W, respectively. At this time, the boundary positions between the convex lens portions 221a and 222a and the concave lens portions 221b and 222b are biased toward the concave lens portions 221b and 222b, unlike the center positions of the lens widths 221W and 222W. Further, the positions of the light emitting portion 14a and the light receiving portion 14b are biased toward the convex lens portions 221a and 222a, which are outside the boundary positions between the convex lens portions 221a and 222a and the concave lens portions 221b and 222b.

Also in the limited reflection type sensor 20 of the present embodiment, the outside of the lens 22 is the convex lens portion 221a and irradiates light over a long distance, and the inside of the lens 22 is the concave lens portion 221b and irradiates light at a short distance. .. Therefore, by using the lens 22 of the present embodiment, the irradiation range of light from the concave lens portion 221b to a short distance can be expanded, the object detection region can be expanded to a closer distance, and the object can be close regardless of the color of the object. It can detect objects located at a distance.

FIG. 10 is a diagram in which the light emitted from the light emitting unit 14a of the limited reflection sensor 20 and the result of the ray trajectory simulation of the region detectable by the light receiving unit 14b are superimposed. As shown in FIG. 10, in the present embodiment, the object detection area is expanded to the long distance side. Further, since the boundary positions between the convex lens portions 221a and 222a and the concave lens portions 221b and 222b are biased toward the concave lens portions 221b and 222b from the center positions of the lens widths 221W and 222W, more light is distributed to the long distance side. Therefore, the amount of light emitted over a long distance can be increased. As a result, the light intensity on the long-distance side can be increased to improve the detection accuracy of the object, and an object located at a short distance can be detected regardless of the color of the object.

As described above, also in the limited reflection type sensor 20 of the present embodiment, the emission light lens 221 and the reflected light lens 222 are provided with convex lens portions 221a and 222a and concave lens portions 221b and 222b, respectively. As a result, the long-distance side of the object detection region R can be enlarged by the convex lens portions 221a and 222a, and the short-distance side can be enlarged by the concave lens portions 221b and 222b to expand the detection range by the limited reflection sensor 20. .. Further, since the boundary position between the convex lens portions 221a and 222a and the concave lens portions 221b and 222b is different from the center position of the lens widths 221W and 222W, the degree of freedom in designing the light distribution on the short distance side and the long distance side is increased. improves. In particular, when the boundary position is biased inward from the center position, the regions of the convex lens portions 221a and 222a become wider than those of the concave lens portions 221b and 222b, and the light distribution to the long distance side is increased to detect on the long distance side. The accuracy can be further improved.

Further, since the light emitting portion 14a and the light receiving portion 14b are located outside the boundary positions between the convex lens portions 221a and 222a and the concave lens portions 221b and 222b, the degree of freedom in design is further improved and the arrangement to the short distance side is improved. It is possible to increase the amount of light. Further, it is possible to expand the detection area on the short distance side while maintaining the range on the long distance side of the detection area.

Further, in the limited reflection type sensors 10 and 20 of the present invention, the light distribution to the short distance side and the long distance side of the object detection region R can be controlled only by exchanging the lens 12 and the lens 22, and other parts are shared. can. This is because the degree of freedom in optical design is improved by making the boundary positions of the convex lens portions 121a, 122a, 221a, 222a and the concave lens portions 121b, 122b, 221b, 222b different from the center position of the lens width. This is because it is not necessary to change the arrangement of the 14a and the light receiving unit 14b.

Convex lenses by making the boundary positions of the convex lens portions 121a, 122a, 221a, 222a and the concave lens portions 121b, 122b, 221b, 222b different from the center position of the lens width to improve the degree of freedom in the optical design of the lenses 12 and 22. The thicknesses of the portions 121a, 122a, 221a, 222a and the concave lens portions 121b, 122b, 221b, 222b can be reduced, and the lenses 12, 22 and the limited reflection type sensors 10, 20 can be miniaturized.

It should be noted that the embodiments disclosed this time are examples in all respects and do not serve as a basis for limited interpretation. Therefore, the technical scope of the present invention is not construed solely by the above-described embodiments, but is defined based on the description of the claims. It also includes all changes within the meaning and scope of the claims.

10, 20 ... Limited reflection type sensor 11 ... Housing part 12, 22 ... Lens 13 ... Mounting substrate 14a ... Light emitting part 14b ... Light receiving part 11a ... Mounting part 11b ... Lens housing part 11c ... Lens holding part 11d ... Light emitting housing part 11e ... Light receiving accommodating portions 121,221 ... Emission light lenses 122, 222 ... Reflected light lenses 121a, 122a, 221a, 222a ... Convex lens portions 121b, 122b, 221b, 222b ... Concave lens portions 121W, 221W ... Lens widths 123, 223 ... Flat plate portions 123a, 223a ... Separation grooves 123b, 223b ... In / out surfaces 124, 224 ... Flange portions

Claims (4)

Limited to irradiating the emitted light from the light emitting unit toward the object detection area via the outgoing light lens and receiving the reflected light from the object existing in the object detection area at the light receiving unit via the reflected light lens. It ’s a reflective sensor,
The emission light lens and the reflective light lens is formed integrally with the flat plate portion, a first surface that faces the object detection region of said plate is substantially flat surface, the opposite to the first surface Separation grooves are provided between the emitted light lens and the reflected light lens on the two surfaces.
Wherein the second surface side of the emitting light lens and the reflective light lens has a side toroidal lens area close to the separation grooves, respectively, and a far side of the convex lens region from the isolation trench,
When the range of the emitted light lens and the reflected light lens on the second surface side is the lens width W1 and the lens width W2, respectively.
In each of the emitted light lens and the reflected light lens, the boundary position between the toroidal lens region and the convex lens region is different from the center position of the lens width W1 and the lens width W2 .
The limited reflection type sensor , wherein the light emitting unit or the light receiving unit is arranged at a position biased toward the convex lens region side with respect to the boundary position. The limited reflection type sensor according to claim 1.
A limited reflection type sensor characterized in that the boundary position is biased toward the toroidal lens region side with respect to the center position. The limited reflection type sensor according to claim 1.
A limited reflection type sensor characterized in that the boundary position is biased toward the convex lens region side with respect to the center position. The limited reflection type sensor according to any one of claims 1 to 3.
A limited reflection type sensor characterized in that the separation groove reaches the second surface side of the flat plate portion and is provided in a tapered shape.

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