JP7219944B2 - ultra proximity switch - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Act Presented at the 2017 18th Student Research Presentation Meeting of the Kyushu Branch of the Japan Society for Precision Engineering held on December 2, 2017.

The present invention relates to a super-proximity switch for detecting whether or not an object to be detected is arranged within a range of a predetermined distance from a reference position.

The advanced technology of precision microfabrication in recent years has increased the processing accuracy through the use of high-precision machining centers. Along with this, the tool setter is required to detect the tool length, the tip position of the cutting edge of the tool, and the like with an accuracy of the order of submicron (one tenth of 1 μm).
Tool setters can be broadly classified into contact type (for example, Non-Patent Document 1) and non-contact type (for example, Non-Patent Document 2) based on the difference in detection method, for example. Since the contact type requires the cutting edge of the tool to come into contact with the tool setter, the cutting edge of the tool may be damaged or chipped. In recent years, there are tool setters designed to reduce the contact force, but it is not possible to bring the rotating tool into contact with the tool setter, making it impossible to detect the position of the cutting edge. On the other hand, the non-contact type does not require contact with the tool, so it is possible to prevent breakage of the cutting edge of the tool and detect the position of the cutting edge of the tool during rotation.

Metrol Co., Ltd., tool setter/touch probe for machine tools, general catalog, No. C5-1, 2-25 (2015) Atsuo Nakai, On-machine measurement software "Form Control" and micro tool measurement laser, Mechanical Engineering, 2006, Vol. 54, No. 7, p. 47-50

However, the non-contact type has a problem that it cannot detect with high accuracy (for example, accuracy of submicron order). In addition, non-contact high-precision detection can be used not only for tool setters, but also for a wide range of other possible applications for ultra-proximity switches (e.g., head position detection for reading and writing optical disks, manufacturing processes for semiconductor products, etc.). It is also effective for product position detection in
SUMMARY OF THE INVENTION It is an object of the present invention to provide a super-proximity switch with high detection accuracy.

A super-proximity switch according to the present invention that meets the above object is a super-proximity switch that includes a light-transmitting body and detects that an object to be detected is arranged near the front side of a predetermined surface F of the light-transmitting body. irradiates a first light to generate a layer L1 in which the near-field light E1 exists on the front side of the surface F, irradiates a second light having a wavelength different from that of the first light, and irradiates the near field light E1. irradiating means for generating a layer L2 thicker than the layer L1, in which the field light E2 exists, on the front side of the surface F in a state where the layer L1 and the layer L2 overlap, and the near-field light E1 Outside the layer L2, the layer detection means for detecting whether the detection object is placed in the area within L2 and outside the layer L1 or within the layer L1 ; and signal transmission means for outputting signals S1 and S2 to the outside. , the optical paths of the first and second lights from the irradiation means to the surface F coincide, the irradiation means simultaneously irradiates the first and second lights, and the signal transmission means The signal S1 is output in a state where the detection object is arranged outside L2, and the signal S2 is output, and the signal S1 is output by detection by the detection means of the entry of the detection object into the layer L1, and the detection means is one, and the second scattered light and the Detecting the entry of the detection target into a region within the layer L2 and outside the layer L1 from the increase in the measured value of the intensity of light of the same wavelength compared to the value when the detection target is not present in the layer L2. Detecting that the detection target has entered the layer L1 from the increase in the measured value of the intensity of light having the same wavelength as the first scattered light compared to the value when the detection target is not present in the layer L2. and the light transmitting body has an arc-shaped surface that refracts the first and second scattered lights emitted from the light transmitting body through the light transmitting body toward the detection means, and the object to be detected is the tip of the tool .

The super proximity switch according to the present invention irradiates first and second lights with different wavelengths to form a layer L1 in which the near-field light E1 exists and a layer L2 in which the near-field light E2 exists and is thicker than the layer L1. are generated on the front side of the surface F of the transparent body, and the first scattered light generated when the near-field light E1 is reflected by the detection target, and the second scattered light generated when the near-field light E2 is reflected by the detection target Based on the detection of the scattered light, it is detected whether the detection target is arranged outside the layer L2, within the layer L2 and outside the layer L1, or within the layer L1. Therefore, the thickness of the layers L1 and L2 It is possible to detect the arrangement of the object to be detected with a level of accuracy (for example, submicron order).

1 is an explanatory diagram of a super proximity switch according to one embodiment of the present invention; FIG. (A), (B), and (C) are explanatory diagrams showing the relationship between the position of the object to be detected and the generation of the first and second scattered lights. It is a block diagram which shows the connection of a detection means. 4 is a graph showing the relationship between the position of the tip of the tool and the measured value of light intensity.

Next, specific embodiments of the present invention will be described with reference to the attached drawings for better understanding of the present invention.
As shown in FIGS. 1 to 3, a super proximity switch 10 according to one embodiment of the present invention includes a transparent body 11 and light P1 (first light) and light P2 (second light). and detection means 13 for detecting the arrangement of the detection object W from the measurement of the light intensity. It is detected that the object W is arranged. A detailed description will be given below.

As shown in FIG. 1, the super-proximity switch 10 has a housing 16 containing an irradiating means 12 and a detecting means 13, and the translucent body 11 is placed and fixed in the housing 16. As shown in FIG. In this embodiment, a translucent body 11 made of syria glass is used, and the translucent body 11 has a surface 14 horizontally arranged with a distance from a housing 16, and a semicircular shape arranged in parallel. has an arcuate surface 19 that contacts the housing 16 and connects the surface 14 and the side surfaces 17, 18.

The wavelength of the light P1 and the light P2 emitted from the irradiation means 12 is shorter than the wavelength of the light P2 (that is, the light P1 and P2 have different wavelengths). are used, but the irradiation means 12 is not limited to this. The irradiating means 12 emits light P1 and P2, as shown in FIGS. Arriving from the back side, being totally reflected by the surface 14 , the light is arranged in the direction of coming out of the transparent body 11 from the arcuate surface 19 of the transparent body 11 .

When the lights P1 and P2 are totally reflected by the surface 14 of the transparent body 11, near-field light (evanescent light) E1 through which the light P1 seeps out and near-field light E1 through which the light P2 seeps out are formed on the front side of the surface 14. (Evanescent light) E2 is generated respectively. Therefore, the irradiation means 12 irradiates the light P1 and P2, and the layer L1 where the near-field light E1 exists (localizes) and the near-field light E2 exists (localizes) on the front side of the surface 14 of the transparent body 11. ) to generate a layer L2. As shown in FIG. 2A, the layers L1 and L2 are provided continuously from the surface 14 of the translucent body 11 (so as not to have a gap with the surface 14). is thicker than layer L1, and layers L1 and L2 have overlapping regions. In this embodiment, the layers L1 and L2 have thicknesses of 220 nm and 300 nm, respectively, and the entire layer L1 partially overlaps the layer L2.

The object W to be detected is the tip of the tool T, and the tool T is supported above the translucent body 11 by a position adjusting member (not shown), as shown in FIG. The position adjusting member can raise and lower the tool T, and the tool T is lowered by the position adjusting means as shown in FIGS. enter in.
As shown in FIG. 2A, when the detection object W is arranged above the layer L2, that is, outside the layer L2 (area outside the layer L1 and outside the layer L2), the near-field lights E1 and E2 are It does not hit the object W to be detected and no scattered light is generated.

On the other hand, as shown in FIG. 2(B), when the detection object W is arranged in a region outside the layer L2 and the layer L1, the near-field light E2 is reflected by the detection object W and scattered. When the light Q2 (second scattered light) is generated and the object W to be detected is arranged in the layer L1 (the region within the layer L1 and within the layer L2) as shown in FIG. In addition to the scattered light Q2 generated by the reflection of the field light E2 from the detection target W, the near-field light E1 is reflected from the detection target W to generate the scattered light Q1 (first scattered light). The wavelengths of the scattered lights Q1, Q2 are substantially equal to the wavelengths of the lights P1, P2, respectively.

As shown in FIG. 3, the detection means 13 detects the intensity of light having the same (substantially the same) wavelength as the scattered light Q1 (hereinafter referred to as light having the wavelength λ1) and the same (substantially the same) intensity as the scattered light Q2. ) based on the sensor unit 20 capable of measuring the intensity of light with a wavelength (hereinafter referred to as light with a wavelength of λ2) and the measurement result (measurement value) of the sensor unit 20, the arrangement of the detection target W is derived. A position detector 21 is provided. The housing 16 is designed so that the light beams P1 and P2 directed from the irradiation means 12 toward the transparent body 11 and the scattered light beams Q1 and Q2 passing through the transparent body 11 and directed toward the detection means 13 are transmitted.

As shown in FIG. 2(A), the position detection unit 21 detects that the object W to be detected is arranged outside the layer L2 when it is determined that both the scattered lights Q1 and Q2 are not detected. As shown in 2(B), when it is determined that the scattered light Q1 is not detected and the scattered light Q2 is detected, it is detected that the detection target W is arranged in the region outside the layer L2 and the layer L1. Then, as shown in FIG. 2C, when it is determined that both the scattered lights Q1 and Q2 are detected, it is detected that the detection target W is arranged in the layer L1.

That is, based on the detection (detection result) of the scattered lights Q1 and Q2 by the sensor unit 20, the position detection unit 21 detects the light outside the layer L2, the area inside the layer L2 and outside the layer L1, or the area inside the layer L1. It is detected whether the object W is arranged.
Here, as shown in FIG. 1, the detection means 13 is arranged so as not to directly receive the lights P1 and P2. In this state, the sensor unit 20 slightly measures light with a wavelength of λ1 and light with a wavelength of λ2 (this includes disturbance light, part of the light P1 and P2 reflected by the surface 14 of the transparent body 11, and the like). Conceivable).

Therefore, in the present embodiment, detection of light with wavelength λ1 by the sensor unit 20 cannot be treated as detection of scattered light Q1, and detection of light with wavelength λ2 by the sensor unit 20 cannot be treated as detection of scattered light Q2. cannot handle.
Therefore, the intensity of the light with the wavelength λ1 and the intensity of the light with the wavelength λ2 measured by the sensor unit 20 when the detection target W is not placed in the layer L2 are defined as R1 and R2, respectively, and the position detection unit 21 When the measured value of the light intensity of wavelength λ1 by the sensor unit 20 is R1 and the measured value of the light intensity of wavelength λ2 by the sensor unit 20 is R2, the object W to be detected is arranged outside the layer L2. to detect.

When the intensity of light with wavelength λ1 is R1 and the intensity of light with wavelength λ2 is greater than R2 (that is, when the intensity of light with wavelength λ2 is measured by the sensor unit 20), the position detection unit 21 detects an increase in the measured value of the intensity of light with wavelength λ2. from), the entry of the detection object W into the area inside the layer L2 and outside the layer L1 is detected, and the intensity of the light with the wavelength λ1 is greater than R1 and the intensity of the light with the wavelength λ2 is measured by the sensor unit 20 is greater than R2 (that is, from an increase in the measured intensity of light of wavelength λ1), entry of detection object W into layer L1 is detected.

In a state in which the object W to be detected is arranged in a region outside the layer L2 and outside the layer L1, the intensity of the scattered light Q2 increases as the object W to be detected approaches the surface 14 of the translucent body 11. , the position of the detection object W in the layer L2 can be calculated based on the intensity of the light having the wavelength λ2 measured by the sensor unit 20 . In this respect, the same applies to the relationship between the measured value of the light intensity of wavelength λ1 by the sensor unit 20 and the measured value of the light intensity of wavelength λ2 by the sensor unit 20, and the position of the detection target W in the layer L1.
In the present embodiment, the position detection unit 21 derives the position of the detection target W placed in the region inside the layer L2 and outside the layer L1 from the intensity of the scattered light Q2 by the sensor unit 20, The position within the layer L1 of the detection object W placed within the layer L1 is measured from one or both of the intensity of the scattered light Q1 and the intensity of the scattered light Q2.

Moreover, as shown in FIG. 3, the super-proximity switch 10 includes a signal transmission means 22 connected to the position detection section 21 and outputting signals S1 and S2 to the outside. The signal transmitting means 22 outputs the signal S1 to the outside in a state where the detection target W is arranged outside the layer L2, and detects the position of the detection target W entering the area inside the layer L2 and outside the layer L1. 21 outputs the signal S2 to the outside, and the detection by the position detection unit 21 of the entry of the detection target W into the layer L1 outputs the signal S1 to the outside.

In this embodiment, the signals S1 and S2 are an off signal and an on signal, respectively, and the equipment provided with the super proximity switch 10 is provided with an information processing device (not shown) for receiving the signal output from the signal transmitting means 22. ing. When the information processing device receives the ON signal from the signal transmission means 22, the information processing device can detect that the detection target W is arranged in a region inside the layer L2 and outside the layer L1. In conjunction with a position adjusting member that raises and lowers the tool T, the object W to be detected is arranged in a region within the layer L2 and outside the layer L1 (within a range of 220 nm or more and 300 nm or less from the surface 14 of the transparent body 11). It is possible to maintain the

Next, experiments conducted to confirm the effects of the present invention will be described.
In the experiment, a first light with a wavelength of 450 nm and a second light with a wavelength of 635 nm were irradiated to generate near-field lights E1 and E2 on the front side of a predetermined surface F of the translucent body. The intensity of light with a wavelength of 450 nm and the intensity of light with a wavelength of 635 nm were measured while gradually approaching the surface F of the translucent body from above, and changes in each measured value were recorded.

The measurement results were as shown in FIG. In the graph of FIG. 4, the vertical axis indicates the measured intensity of light of each wavelength, and the horizontal axis indicates the displacement of the tip of the tool from the reference position (hereinafter also simply referred to as "displacement"). Since the intensity of light with a wavelength of 450 nm and the intensity of light with a wavelength of 635 nm at a displacement of 350 nm were equal to the intensity of light measured in advance by bringing the tip of the tool into contact with the surface, the tip of the tool became flat at a displacement of 350 nm. It is believed that he contacted F. In the measurement results, only the measured value of the intensity of light with a wavelength of 635 nm increased in the displacement range of 60 to 175 nm, and the measured value of the intensity of light with a wavelength of 450 nm and the intensity of light with a wavelength of 635 nm increased in the displacement range of 175 to 350 nm. Measurement value increased.

Therefore, it is considered that the tip of the tool entered the layer L2 where the near-field light E2 exists at a displacement of around 60 nm, and entered the layer L1 where the near-field light E1 exists at a displacement of around 175 nm. be done.
Therefore, when the measured value of the intensity of light with a wavelength of 450 nm is V1 and the measured value of the intensity of light with a wavelength of 635 nm is V2, the light with a wavelength of 450 nm is measured when the tip of the tool is arranged outside the layer L2. If the measured value of the intensity of is V1 and the measured value of the intensity of light with a wavelength of 635 nm is larger than V2, the tool tip is in the region inside the layer L2 and outside the layer L1, that is, the width is about 115 nm (= 175-60 nm) If it can be determined that the tool tip is placed in the region, the measured value of the intensity of light with a wavelength of 450 nm is greater than V1, and the measured value of the intensity of light with a wavelength of 635 nm is greater than V2, then it is in the layer L1, that is, , about 175 nm (=350-175 nm).

Moreover, both the measured value of the intensity of light with a wavelength of 450 nm and the measured value of the intensity of light with a wavelength of 635 nm began to increase with the displacement of the tool tip, and then the tool tip came into contact with the surface F of the translucent body. Since the measured value of the light intensity and the position of the tool tip have a one-to-one relationship, it was confirmed that the position of the tool tip can be derived based on the measured light intensity. .

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and all modifications of conditions that do not deviate from the gist of the present invention are within the scope of the present invention.
For example, the signal emitting means may be omitted.
In addition, adopting a detection means having two sensor units that respectively measure the intensity of the first and second scattered lights, and an irradiation unit that irradiates the first light and an irradiation unit that irradiates the second light. It is possible to use irradiation means having
Light having the same wavelength as the first scattered light and light having the same wavelength as the second scattered light are detected in a state where the detection target W is placed at a position where the first and second scattered lights are not generated. If not detected by the means, the detection of the light of the same wavelength as the first scattered light by the detection means is regarded as the detection of the first scattered light, and the detection means detects the light of the same wavelength as the second scattered light. This can be regarded as detection of the second scattered light.

10: Super proximity switch, 11: Translucent body, 12: Irradiation means, 13: Detecting means, 14: Surface, 16: Housing, 17, 18: Side surface, 19: Arc surface, 20: Sensor unit, 21: Position Detection unit 22: signal transmission means L1, L2: layers P1, P2: light Q1, Q2: scattered light T: tool W: object to be detected

Claims (1)

A super-proximity switch that includes a translucent body and detects that an object to be detected is arranged near the front side of a predetermined surface F of the translucent body,
By irradiating the first light, the layer L1 in which the near-field light E1 exists is generated on the front side of the surface F, and by irradiating the second light having a wavelength different from that of the first light, the near-field light irradiating means for generating a layer L2, in which E2 is present, which is thicker than the layer L1, on the front side of the surface F, with the layer L1 and the layer L2 having an overlapping region;
Based on the detection of the first scattered light generated by the reflection of the near-field light E1 from the detection object and the second scattered light generated by the reflection of the near-field light E2 from the detection object, the detection means for detecting whether the detection object is disposed outside the layer L2, within the layer L2 and outside the layer L1, or within the layer L1 ;
A signal transmission means for outputting signals S1 and S2 to the outside ,
optical paths of the first and second lights from the irradiating means to the surface F match;
The irradiation means simultaneously irradiates the first and second lights,
The signal transmitting means outputs the signal S1 in a state in which the detection target is arranged outside the layer L2, and detects the entry of the detection target into a region inside the layer L2 and outside the layer L1. detection by the detection means outputs the signal S2, detection by the detection means of the entry of the detection object into the layer L1 outputs the signal S1;
The detection means is one, and the measured value of the intensity of the light having the same wavelength as the second scattered light is increased from the value when the detection object is not in the layer L2 and Detecting the entry of the detection target into a region outside the layer L1, and the value of the measured intensity of the light having the same wavelength as the first scattered light when the detection target is absent in the layer L2 Detecting that the detection target has entered the layer L1 from the increase in
the translucent body has an arc-shaped surface that refracts the first and second scattered lights that pass through the translucent body and exit from the translucent body toward the detection means;
A super-proximity switch , wherein the object to be detected is a tip of a tool .

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