JP2533257B2 - Optical displacement measuring device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention makes it possible to measure the amount of displacement by irradiating an object with a light beam such as a laser beam and detecting an optical signal reflected from the object by a position detecting element. To the improvement of the optical displacement measuring device.

[0002]

2. Description of the Related Art As shown in FIG. 7, an optical displacement measuring device of this type includes an optical head 100 and a controller 200.
Are connected via a signal line 300, and the optical head 100 is provided with a light projecting section 101 and a light receiving section 102. The light projecting portion 101 of the optical head 100
Includes a light projecting lens 100a, a laser projecting element 100b,
The light emitting element drive circuit 100e is built in, and the light receiving unit 1
Reference numeral 02 denotes a light receiving lens 100c, a position detecting element 100d serving as a light receiving element, and an I / V for converting the position detecting signal output in the form of a current signal from the position detecting element 100d into a voltage.
The conversion circuit 100f is built in.

In such a displacement measuring device, a modulated signal is output from the oscillator 202 of the controller 200 to operate the light projecting element drive circuit 100e, whereby a light beam such as a laser beam is projected from the light projecting unit 101 to the object OB. The reflected light from the object OB is received by the position detecting element 100d through the light receiving unit 102. Then, based on the two current values I1 and I2 output from the position detection element 100d, the displacement amount from the predetermined reference value of the optical head 100 is provided in the controller 200 by using the principle of triangulation. The processing circuit 201 performs arithmetic processing, and the measured value is output and displayed on the display unit 203, and can be output from an output terminal to an external device. However, in the conventional displacement measuring device, only one optical head 100 is connected to one controller 200.

[0004]

Therefore, the above-mentioned conventional method cannot deal with the case where there are a plurality of measurement points to be measured. That is, two optical heads are required to obtain the step ta and the thickness tb on the surface of the object OB, but conventionally, these measurements cannot be performed by a single displacement measuring device, which is very large. It was inconvenient. Conventionally, in order to measure the level difference ta and the thickness tb of the object OB, for example, as shown in FIG. 8, the controllers 200 of the two displacement measuring devices are connected to the interface 204.
It is necessary to connect one controller side to perform addition or subtraction of the values respectively measured via the two optical heads 100, 100. However, like this,
If the controllers 200 of the two displacement measuring devices are used by connecting them to each other, the entire device becomes large and inconvenient to handle, and the entire device becomes very expensive. was there.

The present invention has been made in view of the above points, and even when there are a plurality of measurement points, it is possible to perform appropriate measurement without using a plurality of controllers, and it is small and inexpensive. It is an object of the present invention to provide an optical displacement measuring device that can be manufactured.

[0006]

An optical displacement measuring apparatus according to the present invention as set forth in claim 1, which is proposed to achieve the above object, is a light projecting section for irradiating an object with light. And an optical head having a light receiving section for receiving the light reflected from the object, and data processing according to a position detection signal output from the optical head, which is connected to the optical head via a signal line Then, in the optical displacement measuring device configured by combining the controller for displaying and outputting the distance measurement value, the controller is provided with an input terminal for connecting signal lines derived from a plurality of optical heads and an optical head. Optical head selection switch for selection and data processing according to the position detection signal output from the optical head selected by this selection switch, and the distance measurement value is output to the display unit A configuration in which a signal processing circuit that presents.

According to a second aspect of the present invention, in the optical displacement measuring device according to the present invention, in the configuration according to the first aspect, the input terminal provided in the controller is led out from two optical heads. Signal line is connected to the controller, and the controller is subjected to arithmetic processing of data corresponding to the detection signals output from the two optical heads, and the displacement amount obtained by arithmetic processing is added or subtracted to obtain a step or thickness of the object. Is further provided on the display unit as a distance measurement value.

[0008]

In the optical displacement measuring device according to the present invention having the above-mentioned structure, a plurality of optical heads can be connected to one controller, and the measurement of the plurality of optical heads is desired. When the optical head provided opposite to the measurement point is selected by the optical head selection switch, the displacement amount of the measurement point is displayed on the display unit. That is,
Each of the position detection signals of the plurality of measurement points is output to the signal processing circuit side of the controller by irradiating the target object with light from the light projecting portions of the plurality of optical heads and receiving the reflected light by the light receiving portion. However, by arbitrarily selecting the optical head corresponding to the desired measurement point with the optical head selection switch, the displacement amount of the measurement point measured by the selected optical head is processed in the controller. After that, the value can be displayed on the display unit as a distance measurement value. Therefore, it is possible to measure displacements at a plurality of positions using a plurality of optical heads by using only one controller without using a plurality of controllers.

Further, in the optical displacement measuring device according to the present invention as set forth in claim 2, displacement of two measuring points can be measured by two optical heads connected to the controller. If you select step measurement or thickness measurement of the object by operating the switch, after the data of the displacement amount according to the detection signal output from each of the two optical heads is added or subtracted, the step or thickness of the object is The distance measurement value is displayed on the display unit.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 is a block diagram showing a hardware configuration of an optical displacement measuring device, FIG. 2 is a block diagram showing a hardware configuration of a signal processing circuit, FIG. 3 is an external perspective view of the entire device, and FIG. 4 is a configuration around a display portion of a controller. And FIG. 5 is a rear view of the controller.

The optical displacement measuring device is constructed by connecting two optical heads H1 and H2 to one controller C via signal lines 2a and 2b. Of these, the essential basic configurations of the two optical heads H1 and H2 are exactly the same. Each projection unit 3 of the optical heads H1 and H2
Reference numeral a denotes a light projecting lens L1, a laser light projecting element LA, and a light projecting element drive circuit 4.
By receiving the oscillation signal from the oscillator 5 of the controller C, the laser projecting element LA can continuously output and irradiate the modulated laser beam to the object OB. Both optical heads H1 and H2 share one oscillator 5 in the controller C. The light receiving part 3b is the object O
The light receiving lens L2 that receives the reflected light from B, the position detection element PSD that serves as a light receiving element, and the position detection signals I1 and I2 (I1 ′, I1 ′, I1) as current signals from the position detection element PSD.
I2 ′) is converted into a voltage by an I / V conversion circuit 6. Position detection signals I1, I2 (I1 ', I
2 ') corresponds to the displacement amount of the measurement point from the predetermined reference position.

The controller C uses the optical heads H1 and H2.
The input terminals 7a and 7b for detachably connecting the signal lines 2a and 2b derived from the above are provided on the rear panel side. Inside the controller C, in addition to the oscillator 5 described above, optical heads H1 and H2 are provided. Switching circuit 8 for sequentially switching and receiving the position detection signals output from each of the two, and processing the data in accordance with the position detection signals transmitted via the switching circuit 8 to calculate the triangular distance measurement. A signal processing circuit 9 for calculating the displacement amount of the object OB based on the principle is incorporated. On the front operation panel of the controller C, as shown in FIG. 4, a display unit 10 including a liquid crystal display for displaying the distance measurement value calculated by the signal processing circuit 9 and two optical heads H1 and H2 are used. Optical head selection switches S1 and S2 for selection, object O
Measurement target selection switches Sa and Sb for selecting step measurement or thickness measurement of B are provided. Each of these switches S1, S2, Sa and Sb has a light emitting diode (LED) or the like inside the operation key thereof, and is configured to light up when turned on by a key operation. In the figure, 11a and 11b are unit selection switches for displaying the distance measurement value displayed on the display unit 10 in inches or mm. The above-mentioned switches and the display unit 10 are connected to the signal processing circuit 9.

The switching circuit 8 has an input terminal 7
The switching operation with the switching contacts SWa and SWb connected to a and 7b is performed based on the control command from the switching control circuit 12. By switching the switching contacts SWa and SWb alternately at a predetermined time interval, , Both optical heads H
It is possible to alternately input two position detection signals output from both 1 and H2 to the signal processing circuit 9 side.
In this embodiment, the optical head selection switches S1 and S2 are
Thus, for example, even when only the optical head H1 on one side is selected, the switching contacts SWa and SWb are switched in the same manner as described above. In such a case, for example, the switching contact S
It is also possible to maintain the connection with the switching contact SWa side according to the selected optical head H1 without performing the switching operation of Wa and SWb.

As shown in FIG. 2, the signal processing circuit 9 detects the position detection signal in synchronization with the oscillation signal from the amplifier 9b for amplifying the voltage-converted position detection signal from the switching circuit 8 and the oscillator 5. Then, a detection circuit 9c for extracting only the oscillation signal component, an A / D converter 9d for converting the position detection signal detected and output from the detection circuit 9c into a digital signal, and data corresponding to the position detection signal converted into the digital signal Is stored in the corresponding memory unit 9e, and the CPU 9a is provided for calculating the displacement amounts a and b of the measurement point of the object OB from the stored data based on the principle of triangulation. However, the CPU 9a performs data processing of the position detection signals output from both the optical heads H1 and H2 in parallel, and the above-described optical head selection switches S1 and S are used.
When the optical head on either side is selected in 2,
The displacement amount of the measurement point measured by the selected optical head with respect to a predetermined reference point is output and displayed on the display unit 10 as a distance measurement value. Also, the measurement target selection switch S
When either a or Sb is turned on, the displacement amounts a and b of the measurement points of the optical heads H1 and H2 are added or subtracted, and the value is switched and displayed on the display unit 10. That is, when the measurement of the step ta is selected by the measurement target selection switch Sa, the displacement amount (ab) is calculated to obtain the step ta, and the value is displayed on the display unit 10. Also,
When the thickness measurement is selected by the measurement target selection switch Sb, the displacement amount (a + b) is calculated. The value of (a + b) of the displacement amount is, as shown in FIG.
It corresponds to the thickness tb of B, and the value of the thickness tb is also displayed on the display unit 10.

The signal processing circuit 9 includes a D / which converts the distance measurement data processed by the CPU 9a into an analog signal.
An A converter 13 is separately connected, and an output terminal 14 for outputting a serial signal to a computer or other external device.
Is provided. In addition to this, an input / output terminal block 15 for remote control operation is also connected to the signal processing circuit 9 via a control input circuit 16. The input / output terminal block 1
5 is for holding the distance measurement data obtained by the signal processing circuit 9 and zero-setting the value of the position of a desired measurement point, including on / off control of the laser beam irradiation from the optical heads H1 and H2. It is provided with a terminal for performing zero-setting operation, etc., or an output terminal for various warnings. Further, in FIG. 5, the upper side 1 of the input / output terminal block 15
5a is for the optical head H1, the lower side 15b is the optical head H1.
It is configured for two. However, with the input / output terminal block 15 and the output terminal 14, even if only one optical head side is selected by operating the optical head selection switches S1 and S2, for example, two optical heads H
It is possible to output the data of each distance measurement value measured by both 1 and H2 to the outside.

In the optical displacement measuring device having the above-described structure, the position detection signals output from the two optical heads H1 and H2 can be alternately input to the signal processing circuit 9 via the switching circuit 8 and each optical head. The signal processing circuit 9 can perform a calculation process on a desired displacement amount for measurement at two points irradiated with the laser beams from the heads H1 and H2. And
If one of the two optical heads H1 and H2 is selected by operating the optical head selection switches S1 and S2,
The displacement amount of the measurement point measured by the selected optical head is output and displayed on the display unit 10 as a distance measurement value. Therefore, by arranging the optical heads H1 and H2 at different measurement points respectively, it becomes possible to selectively and easily measure two measurement points with one optical displacement measuring device. If one of the measurement object selection switches Sa and Sb is turned on, the optical heads H
The displacement amounts a and b of the respective measurement points measured via 1 and H2 are subtracted (ab), and the value is automatically displayed on the display unit 10 as a distance measurement value. Therefore, the object O in FIG.
The step ta of B can be easily measured. On the other hand, when the measurement target selection switch Sb is turned on, the displacement amounts a and b at the two measurement points are added (a + b), and the value is automatically displayed as the distance measurement value on the display unit 10. To be done. Therefore, FIG.
The thickness tb of the target object OB can be easily measured.

When measuring such a step or thickness, it is desirable that the position detection signals output from both the optical heads H1 and H2 be switched by the switching circuit 8 and processed by one signal processing circuit 9. In such a configuration, the distance measurement value is more accurate than in the case where the two signal processing circuits are used to perform individual processing. That is, this type of signal processing circuit has its own temperature characteristic and aging characteristic, and has the characteristic that its output voltage level undergoes offset drift under operating temperature conditions other than the rated temperature. Therefore, when the two signal processing circuits are used, the offset error amounts are different, so that the drift error is included as the error of the measurement value, and the error of the measurement value increases. But,
If all the arithmetic processing is performed by one signal processing circuit 9 as in the above-described embodiment, a drift error in the case of using a plurality of signal processing circuits does not occur, and highly accurate displacement measurement becomes possible. There are advantages. However, such a configuration is not an essential requirement of the present invention. Further, in the above description, the case where two optical heads H1 and H2 are provided has been described as an example, but in the present invention according to claim 1, three or more optical heads may be provided.

[0018]

As can be understood from the above description, according to the optical displacement measuring apparatus of the present invention as defined in claims 1 and 2, even when there are a plurality of measuring points, the conventional method is used. There is no need to connect multiple large and costly controllers using multiple displacement measurement devices like the above, and to selectively use multiple optical heads connected to one controller. Since the amount of displacement of the measurement point can be measured, the measurement work is convenient, and there is an extraordinary effect that the entire device is not wasted, and the entire device can be made compact and inexpensive. Particularly, according to the optical displacement measuring device of the present invention as defined in claim 2, the distance measurement value obtained by adding and subtracting the displacement amount measured using the two optical heads is displayed on the display unit. As a result, it is possible to obtain an advantage that the step and the thickness of the object can be very easily measured.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a hardware configuration of an optical displacement measuring device according to the present invention.

FIG. 2 is a block diagram showing an example of a hardware configuration of a signal processing circuit.

FIG. 3 is an external perspective view showing an embodiment of an optical displacement measuring device according to the present invention.

FIG. 4 is a front view of the main parts showing an example of the configuration around the display unit provided on the front panel of the controller.

FIG. 5 is a rear view of the controller showing an example of the configuration of the rear panel of the controller.

FIG. 6 is a cross-sectional view of an essential part showing an example in which the thickness of an object is measured.

FIG. 7 is a block diagram showing an example of a conventional optical displacement measuring device.

FIG. 8 is a perspective view showing a state in which two conventional optical displacement measuring devices are connected and used.

[Explanation of symbols]

 2a, 2b Signal line 3a Light emitting unit 3b Light receiving unit 5 Oscillator 8 Switching circuit 9 Signal processing circuit 10 Display unit C controller H1, H2 Optical head a, b Displacement amount (distance measurement value) S1, S2 Optical head selection switch Sa, Sb Measurement target selection switch ta Step (distance measurement value) tb Thickness (distance measurement value)

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yoshihiko Sugimoto 1048 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Works, Ltd. (56) References JP-A-1-295109 (JP, A) JP-A-63-222202 (JP, A) JP-A-1-196511 (JP, A) JP-A 61-105418 (JP, A) JP-A 63-153418 (JP, A)

Claims (2)

(57) [Claims] 1. An optical head including a light projecting unit for irradiating an object with light and a light receiving unit for receiving light reflected from the object; and a signal line to the optical head. In an optical displacement measuring device connected to a controller for processing data according to a position detection signal output from an optical head and displaying and outputting a distance measurement value, the controller includes a plurality of controllers. Input terminal to connect the signal line derived from the optical head, the optical head selection switch for selecting the optical head, and the data according to the position detection signal output from the optical head selected by this selection switch. An optical displacement measuring device comprising: a signal processing circuit for performing arithmetic processing and outputting and displaying the distance measurement value on a display unit. 2. The signal line derived from two optical heads is connected to an input terminal provided on the controller, and the controller outputs detection signals output from the two optical heads. A measurement target selection switch is further provided for displaying the step or thickness of the target object obtained by adding or subtracting the displacement amount obtained by arithmetically processing the data according to the signal, as a distance measurement value on the display unit. An optical displacement measuring device having a configuration.