JPH01263506A - Light amplification displacement sensor and position control device - Google Patents

Abstract

PURPOSE:To enable the automatic tracing of displacement by light, by providing a phototransistor (PHT) and a photosensor in directions to the interior angle planes of a prism. CONSTITUTION:A prism 1 is provided on a ram plate 30 of a press brake, while PHT 2 and a photosensor 3 are provided in the fore end 31 of a linear actuator. The PHT 2 and the sensor 3 are provided in directions to the interior angle planes 1a and 1b respectively so that a light be reflected by the interior angle planes 1a and 1b and sensed by the sensor 3. The prism 1 is provided to that it traverses the PHT 2 and the sensor 3, i.e. so that it is movable vertically, and the PHT 2 and the sensor 3 are also provided so that they are movable vertically. When they are displaced relatively, accordingly, the width of bends of an optical path is made large or small by the prism 1. Therefore a return optical path is doubly displaced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates generally to displacement sensors, and particularly to displacement sensors that utilize light beams.

Particularly, the first aspect of the present invention is an optical amplification displacement sensor that amplifies light using an internal angle reflecting means having a light reflecting surface at an internal angle.

The second invention uses this optically amplified displacement sensor to form an optically amplified displacement sensor that detects displacement using a pair of light receiving sections and a differential amplifier.

Furthermore, the third invention uses the second invention to control the driving means, thereby controlling the movement of the internal angle reflecting means, etc., thereby providing a position control device that completely controls the position. be.

Further, the fourth invention controls the driving means with an optical displacement sensor that detects displacement using a pair of light receiving portions and a differential amplifier,
Therefore, the present invention relates to a position control device that controls the movement of a non-measurable object and thereby performs complete position control.

Finally, the fifth invention is one in which the light receiving portion of the fourth invention is particularly improved for position tracking, and relates to a position control device for position tracking.

[Prior Art] Various types of displacement detectors have conventionally existed, such as contact type mechanical type, and non-contact type such as magnetic type and optical type. A typical example of an optical type is a combination of a light emitting diode and a phototransistor facing each other.

Furthermore, there are position control devices that are purely mechanical or purely hydraulic, and there are also those that combine mechanical or hydraulic types with electric or electronic controllers.

[Problems to be Solved by the Invention] In a combination of a light emitting diode and a phototransistor facing each other, the displacement of the light emitting diode or phototransistor and the displacement of the optical path of the light beam are l:1, so the accuracy of displacement detection is low. It's not something that goes up, so
Not suitable for measuring minute displacements.

Now, the displacement of the non-measurable object and the displacement of the optical path of the light beam are 1
If there is a pair 2, that is, the optical path of the light beam is displaced by 2 mm when the non-measured object is displaced by 11, the accuracy of displacement detection will be doubled, making it possible to measure minute displacements. Optical displacement detectors differ from mechanical and 8i-type displacement detectors because there is no mechanical load (resistance) on the measuring device itself, making it ideal for measuring the displacement of non-measurable objects with minute and very weak displacement forces. I can do something like that.

Of course, the fact that the displacement of the optical path is doubled makes it very suitable for measuring the displacement of large objects. For example, if the object to be measured is displaced by 1 m, its optical path will be displaced by 2 m, so that the displacement can be easily detected with high accuracy. In particular, it is impossible to measure a non-measurable object where only the speed of displacement is high and the displacement force is minute and very weak using a mechanical type. Of course, it is impossible to measure the displacement of large objects using the magnetic method.

In this way, if there were an optical displacement detector that could double the displacement of the optical path, its range of applications would greatly expand. However, since there was no conventional displacement detector capable of such optical amplification, it was subject to various limitations.

Naturally, therefore, since there was no such thing as an optically amplified displacement detector that used a light emitting section capable of optical amplification, a pair of light receiving sections, and a differential amplifier, various restrictions were similarly imposed.

Furthermore, since there was no position control device that controlled the position using a light emitting section capable of optical amplification, a pair of light receiving sections, and a differential amplifier, various restrictions were similarly imposed.

[Means for Solving the Problems] In the optical amplification displacement sensor and position control device according to the present invention, the first invention uses an internal angle reflecting means having a light reflecting surface such as a prism at an internal angle, and A light projecting means and a light receiving means are provided toward the inner corner surface. The second invention is such that the light receiving means of the first invention is combined with a pair of light receiving portions and a differential amplifier. Further, the third invention completely controls the position of the internal angle reflecting means and the like by controlling the driving means using the output of the second invention.

The specific configurations of the optically amplified displacement sensor and position control device according to the present invention will be described in detail below.

First, the first invention will be described. This is an optically amplified displacement sensor. First, there is an internal angle reflecting means having a light reflecting surface such as a prism at an internal angle, particularly at a right angle. Next, there is a light projecting means and a light receiving means. The light projecting means and the light receiving means are provided toward the internal angle surface of the internal angle reflecting means.

Thus, the internal angle reflecting means and/or the light projecting portion of the light projecting device and/or the light receiving portion of the light receiving device are provided so as to be movable in a relatively transverse relationship.

Next is the second invention, which utilizes all of the above-described first invention, so all of the configurations of the above-described optical amplification displacement sensor are used here.

The light receiving means described above is comprised of a pair of light receiving portions arranged next to each other and a differential amplifier inputting the outputs from the pair of light receiving portions.

The third invention is a position control device that utilizes all of the second invention, so all of the configurations of the optical amplification displacement sensor described above are used here.

Accordingly, it is controlled by the differential amplifier of the second aspect of the invention, and the internal angle reflection means and/or the light emitting portion of the light emitting means and/or the light receiving portion of the light receiving means are controlled by the differential amplifier of the second aspect of the invention. Drive means are provided for moving in transverse relation.

Furthermore, since the fourth invention omits the internal angle reflection means of the third invention, all of the configurations of the third invention except for this are incorporated herein.

Finally, the fifth invention relates to a position control device for position tracking. This is because the light-receiving portions of the fourth aspect of the invention are arranged side by side and are rectangular extending in the moving direction of the reflected light, and the reflected light is received no matter where it is located. It's about the size.

The other configurations are the same as the fourth invention described above.

[Function] Since the optical amplification displacement sensor and position control device according to the present invention have the above-described configuration, the following effects occur.

First, the first invention is that the light emitting means and the light receiving means of the optical amplification displacement sensor are provided toward the inner angle surface of the inner angle reflecting means, such as a prism, which has a light reflecting surface at an inner angle, particularly at a right angle. , the optical path becomes a U-shape that is bent by this internal angle reflection means.

The internal angle reflecting means and/or the light emitting portion of the light emitting means and/or the light receiving portion of the light receiving means are provided so as to be movable in a relatively transverse relationship. When the relative displacement occurs, the bending width of the optical path becomes wider or narrower depending on the reflecting means. Therefore, the optical path returning from this internal angle reflection means will undergo twice the displacement.

In the second invention, since the light receiving means is composed of a pair of light receiving parts arranged next to each other and a differential amplifier inputting the output from the pair of light receiving parts, When there is a displacement of light from the light projecting means, the differential amplifier outputs this displacement.

In the position control device of the third aspect of the invention, the drive means is controlled by the output signal from the second aspect of the invention, and the drive means is controlled by the internal angle reflection means and/or the light projection means and/or the light receiving means. The light-receiving portion of the means is moved into transverse relation.

Furthermore, in the fourth invention, since the internal angle reflection means of the third invention is omitted, all of the functions of the third invention except for this are incorporated herein.

Finally, in the fifth invention, the pair of light-receiving parts are arranged next to each other and have a rectangular shape extending in the moving direction of the reflected light, and where the reflected light is located. Because it is large enough to receive even light, its activation is complete and quick, and its light-receiving portion completely covers the reflected light even during operation.

[Embodiments] Hereinafter, the optical amplification displacement sensor and position control device according to the present invention will be explained in detail using respective embodiments thereof with reference to the accompanying drawings.

FIG. 1 is a schematic side view of an embodiment of a press brake using the first invention of the optically amplified displacement sensor and position control device according to the present invention. FIGS. 2, 3, 4, and 5 are side views of one embodiment of the internal angle reflecting means, showing the optical path.

First, the first invention will be described. This is an optically amplified displacement sensor. First, a prism l is provided on the ram plate 30 of the press brake. Instead of this prism 1, any material having a light reflecting surface at an internal angle, particularly at a right angle, may be used, such as connecting two mirrors with their inner surfaces facing inside, one side at a time. Therefore, as shown in FIG. As shown, a corner cube shaped like a prism by cutting out one stroke of a rectangular parallelepiped may be used. This angle is not necessarily limited to a right angle, but is determined by the relationship between the position of the phototransistor 2 and the position of the optical sensor 3.

Next, a phototransistor 2, which is part of the light projecting means, and an optical sensor 3, which is part of the light receiving means, are provided at the tip 31 of the linear actuator. The phototransistor 2 and the optical sensor 3 are connected to the inner angular surfaces 1a and 1 of the prism 1 described above.
They are provided toward the inner angle surfaces 1a and lb, respectively, so that the light is reflected by the light sensor 3 and received by the optical sensor 3. In this case, if a right-angle prism (or right-angle junction mirror) is used as the prism l, the angle of its attachment does not need to be accurate. This is because even if the rectangular prism is slightly tilted, the reflected light will return accurately as shown in the optical path 4 shown in FIG.

Thus, the prism l is provided so as to be able to move vertically across the phototransistor 2 and the optical sensor 3, that is, in terms of the first II. At the same time, the above-mentioned phototransistor 2 and the above-mentioned optical sensor 3 are also provided vertically movably.

In other embodiments, they may be disposed movably in a transverse relationship with respect to each other, i.e. any of them, or two of them, or even all of them, may be displaced. It may be configured.

In this way, when this prism 1 is displaced from the position shown by the solid line to the position shown by the dotted line as shown in FIG.
The reflected optical path from the point is displaced from the position of the solid line to the position of the dotted line. That is, the reflected optical path from the prism l is displaced twice as much as the amount of displacement of the prism l. Therefore, since optical amplification is performed here, the accuracy of displacement detection is doubled.

FIG. 5 shows an embodiment in which the phototransistor 2 is displaced. That is, when the phototransistor 2 is displaced, the incident optical path to the prism l and the reflected optical path are displaced from the position indicated by the solid line to the position indicated by the dotted line. That is, the incident optical path and the reflected optical path are the total length of the prism l.
This results in a displacement twice the amount of displacement, and optical amplification is also performed here.

Next is the second invention, which utilizes all of the above-described first invention, so all of the configurations of the above-described optical amplification displacement sensor are used here.

As shown in FIG. 7, the optical sensors 3 mentioned above are a pair arranged next to each other, and a differential amplifier 5 inputs the outputs from the pair of optical sensors 3a and 3b.
It uses Therefore, when the reflected light 6 from the prism l is displaced, it affects the outputs of these two optical sensors 3a and 3b. That is, when this reflected light 6 is located in the middle of the two optical sensors 3a and 3b as shown in FIG. 6, its output is balanced. When this reflected light 6 is not located in the middle of the two photosensors 38 and 3b, their outputs are different, so the differential amplifier 6 outputs a signal representing the difference between the two photosensors 3a and 3b. Get out. In this way, the displacement can be detected.

Furthermore, if the above-mentioned pair of optical sensors 3a and 3b are made sufficiently wider than the width of the reflected light as shown in FIG. It does not need to be removed from the optical sensor. Furthermore, as shown in FIG. This is because if it is off, the reflected light cannot be tracked.

In this way, if the reflected light 6 does not deviate from the optical sensor 3, it will have a saturation characteristic as shown in FIG. 9, and can be quickly tracked to its equilibrium point upon activation.

The third invention is a stain position control device that utilizes all of the optically amplified displacement sensor of the second invention, so all of the configuration of the optically amplified displacement sensor described above is used here. .

A cylinder controller 7 and a cylinder 8, which are controlled by the differential amplifier 5 of the second aspect of the invention and serve as driving means, are provided. This cylinder 8 is for moving the prism l-4' and/or the boot transistor 2 and/or the optical sensor 3 into transverse relation.

That is, any of the prism l, the phototransistor 2, or the optical sensor 3 may be controlled by the tracking actuator. In this embodiment, as shown in FIG. The phototransistor 2 is controlled by the actuator 9 for
Furthermore, although the optical sensor 3 described above is provided in the main body for work and is driven by its actuator 10, this may be reversed.

Next, regarding the fourth invention, since the prism 1 of the above-mentioned third invention is omitted, all the configurations of the above-mentioned third invention except for this are incorporated herein.

Finally, the fifth invention is as described in the embodiment of the second invention above, and the pair of receiving portions 3a and 3.
b shows rectangular shapes extending in the moving direction of reflected light arranged next to each other. It is large enough to receive the reflected light no matter where it is located. In this way,
This makes it easy to track the location.

The other configurations are the same as the fourth invention described above.

[Effects of the Invention] The optically amplified displacement sensor and position control device according to the present invention have the above-described configuration, so that optical amplification can be performed very easily. In the second invention, the detection of the displacement has also been further improved. Furthermore, since there is a pair of optical sensors, even if the surfaces of the light emitting means, light receiving means, and internal angle reflecting means become dirty and the light intensity changes, the difference in the light intensity of the pair of optical sensors does not change by °. Improved stability. Furthermore, in the third invention, it is also possible to control the displacement of the object to be detected.

In this way, an automatic displacement tracking device using light became possible. Finally, in the fourth invention, it is possible to use general light projecting means and light receiving means without using those of the first invention in the third invention.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of an embodiment of a press brake using a light amplification displacement sensor, which is a first invention of a light amplification displacement sensor and a position control device according to the present invention. FIG. 2 is a side view of one embodiment of the internal angle reflecting means, showing the optical path. FIG. 3 is a side view of one embodiment of the internal angle reflecting means, showing the relationship between the inclination of the internal angle reflecting means and the optical path. FIG. 4 is a side view of one embodiment of the internal angle reflecting means, showing the relationship between the displacement of the internal angle reflecting means and the displacement of the optical path. FIG. 5 is a side view of one embodiment of the internal angle reflecting means, showing the relationship between the displacement of the light projecting means and the displacement of the optical path. FIG. 6 shows a perspective view of another embodiment of the internal angle reflecting means. FIG. 7 shows a block diagram of another embodiment of the light receiving means and an embodiment of the position control device main body. FIG. 8 is a front view showing the relationship between the light receiving means and the reflected light, FIG. 8 a shows the relationship in width, and FIG. 8 shows the relationship in length. It is. FIG. 9 is a characteristic curve diagram showing the relationship between reflected light movement and output voltage. FIG. 10 shows a block diagram of another embodiment of the arrangement of the tracking actuator and an embodiment of the tracking position control device. l... Prism 2... Phototransistor 3... Optical sensor 4... Optical path 5... Differential amplifier 7... Cylinder controller 8... Cylinder 9... Tracking actuator

Claims (5)

[Claims] (1) An optical amplification displacement sensor characterized by comprising the following: a) An internal angle reflecting means such as a prism having a light reflecting surface at an internal angle, particularly at a right angle, and a light projecting means and a light receiving means provided toward the internal angle surface of the internal angle reflecting means. b) The internal angle reflecting means and/or the light projecting portion of the light projecting device and/or the light receiving portion of the light receiving device are movably provided in a relatively transverse relationship. (2) An optically amplified displacement sensor characterized by being composed of the following: a) An internal angle reflecting means such as a prism having a light reflecting surface at an internal angle, particularly at a right angle, a light projecting means provided toward the internal angle surface of the internal angle reflecting means, and the following light receiving means. b) The light receiving means described above includes a pair of light receiving portions arranged next to each other, and a differential amplifier inputting outputs from the pair of light receiving portions. c) The internal angle reflecting means and/or the light projecting portion of the light projecting device and/or the light receiving portion of the light receiving device are movably provided in a relatively transverse relationship. (3) A position control device characterized by being comprised of the following: a) An internal angle reflecting means having a light reflecting surface such as a prism at an internal angle, particularly at a right angle, a light projecting means provided toward the internal angle surface of the internal angle reflecting means, the following light receiving means, and controlled by the following differential amplifier. and/or the internal angle reflecting means described above;
and a driving means for moving the light emitting portion of the light projecting means and/or the light receiving portion of the light receiving means in a transverse relationship. b) The light receiving means described above includes a pair of light receiving portions arranged next to each other and a differential amplifier inputting outputs from the pair of light receiving portions. (4) A position control device characterized by being comprised of the following: a) A pair of light emitting means, the following light receiving means, and a device controlled by the following differential amplifier in a relationship that crosses the light emitting part of the above light emitting means and/or the light receiving part of the above light receiving means. Drive means for moving. b) The light receiving means described above includes a pair of light receiving portions arranged next to each other and a differential amplifier inputting outputs from the pair of light receiving portions. (5) A position control device for position tracking, characterized by comprising the following: a) A pair of light emitting means, the following light receiving means, and a device controlled by the following differential amplifier in a relationship that crosses the light emitting part of the above light emitting means and/or the light receiving part of the above light receiving means. Drive means for tracking the position of movement. b) The above-mentioned light receiving means is a pair of light receiving means that are arranged next to each other, have a rectangular shape extending in the moving direction of the reflected light, and are large enough to receive the reflected light no matter where it is located. and a differential amplifier that inputs the outputs from the pair of light-receiving parts.