JPH0921613A - Optical axis adjusting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly adjust the optical axis by detecting light beams from a light-emitting element of an optical displacement sensor for correcting position of the light-emitting element by a beam profiler and adjusting the distance between the beam profiler and the optical displacement sensor. SOLUTION: A distance adjusting means consists of a Z slider 8 driven by a Z motor 9 and set on a base 7. An S slider 16 driven by an S motor 15 is arranged at the slider 8. The distance between light-emitting element 1 of an optical displacement sensor and a beam profiler 23 is set to be a certain value by controlling the distance-adjusting means. A projection position of light beam to the beam profiler 23 in this state is measured. Then, the distance between the element 1 and the beam profiler 23 is set to a different value, and the projection position of light beams to the beam profiler 23 is measured again. The difference of measured results corresponding to two kinds of distances is obtained, based on the difference value, positional displacement of the element 1 is calculated. The optical axis is correctly adjusted by light-emitting element adjustment means 10-14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical axis adjusting machine for adjusting an optical axis of an optical displacement meter and adjusting a light beam diameter.

[0002]

2. Description of the Related Art FIG. 4 is a diagram showing the principle of measurement in the optical axis direction of an optical displacement gauge, and particularly shows the outline of the sensor portion of the optical displacement gauge. The measurement of the measurement object moving in the optical axis direction will be described with reference to this figure. The light emitted from the light emitting element 1 is condensed by the light projecting lens 2 and projects a light beam on the measurement object 3. The light beam is projected onto the position detecting element 5 by the light receiving lens 4.

When the object 3 moves from the light projection reference position L by + S dimension, the light beam projected on the position detecting element 5 moves from the light receiving reference point by + ΔS dimension. Conversely, when the measurement object 3 moves by -S, the light beam projected on the position detection element 5 moves by -ΔS. By detecting this change, the displacement amount of the measurement object can be measured. FIG. 5 is a diagram showing the principle of measurement in the perpendicular direction of the optical displacement meter, which shows the case where the measurement object 3 is used for measuring the amount of movement of the measurement object moving in the direction perpendicular to the optical axis. When it moves in the direction of the arrow in the figure, that is, in the upward direction of the figure, and comes to the optical axis, the light beam becomes
Is projected onto the edge portion of the object, which is projected onto the position detecting element 5, and the position of the measured object 3 can be detected.

In this case, it is necessary that the measured value of the object to be measured is the same regardless of the position where the measurement error is within ± S.

[0005]

The optical axis of the above-described optical displacement gauge after assembly may be displaced with respect to the sensor base 6 due to the influence of variations in processing accuracy and assembly accuracy of parts.
FIG. 6 is an explanatory diagram showing the influence of the optical axis shift in the optical axis direction,
In this figure, when the light emitting element 1 is displaced from the reference position by the dimension d, the projected beam is displaced by the dimension e, and the received beam is displaced by the dimension f. In order to eliminate this, it is necessary to move the position detection element 5 by the size of f or change the setting of the amplifier 27 shown in FIG. 2 that processes the output signal from the position detection element.

In the latter case, the light receiving characteristic is changed by changing the setting of the amplifier, and the sensor and the amplifier 27 must be used as a pair. Further, if the optical axis shift is large, the received light beam may deviate from the position detection element 5. FIG. 7 is an explanatory view showing the influence of the optical axis shift in the right angle direction. As shown in the figure, at the positions of + S and −S with respect to the reference position L, the g dimension shifts and a measurement error occurs. .

As described above, since the optical axes are displaced and the sensors are not compatible with each other, and measurement errors occur, they cannot be used for precise measurement. Further, there is a problem that the optical axis cannot be adjusted because the light beam cannot be physically measured.

[0008]

SUMMARY OF THE INVENTION The present invention is directed to a light emitting element that emits a light beam for projecting onto a measurement object, a projection lens that receives the light beam and projects it onto the measurement object, and a measurement object. An optical axis adjuster that adjusts the optical axis of an optical displacement gauge that consists of a position detection element that receives the reflected light from the optical axis and measures the position of the object to be measured. A light emitting element adjusting means for correcting the position of the light emitting element, a beam profiler for detecting a light beam from the light emitting element, and a distance adjusting means for adjusting the distance between the beam profiler and the optical displacement meter, The feature is that the position shift of the light emitting element is calculated, the position of the light emitting element is corrected, and the optical axis is correctly adjusted.

[0009]

First, by controlling the distance adjusting means, the distance between the light emitting element of the optical displacement gauge and the beam profiler is set to a certain value, and the projection position of the light beam on the beam profiler in this state is measured. . Next, the distance between the light emitting element of the optical displacement meter and the beam profiler is reset to another value, and the projection position of the light beam on the beam profiler in that state is measured again.

The difference between the two measurement results corresponding to the two kinds of distance values thus obtained is calculated, the positional deviation of the light emitting element is calculated based on the difference value, and the light emitting element adjusting means is operated. The light emitting element is displaced as much as necessary to eliminate the displacement of the light emitting element, the optical axis is adjusted correctly, and the light emitting element is fixed in that state.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of the optical axis adjusting mechanism portion of the embodiment. A Z slider 8 is provided on the base 7 and is driven by a Z motor 9. The Z slider 8 and the Z motor 9 serve as distance adjusting means for adjusting the distance between the light emitting element 1 of the optical displacement meter and the beam profiler described later.

A Y slider 11 driven by a Y motor 10 is provided on the Z slider 8, and an X slider 13 driven by an X motor 12 is provided on the Y slider 11. This X
Chuck claws 14 are attached to the slider 13. The Y motor 10, the Y slider 11, the X motor 12, the X slider 13, and the chuck claw 14 serve as a light emitting element adjusting means that holds the light emitting element 1 and corrects the position of the light emitting element.

The Z slider 8 is further provided with an S slider 16 driven by an S motor 15.
A shift claw 17 is attached to the position 6. These S
The motor 15, the S slider 16 and the shift claw 17 serve as a projection lens adjusting means for holding the projection lens 2 of the optical displacement meter and correcting the position of the projection lens. The sensor base 6 of the optical displacement gauge is positioned and fixed on the Z slider 8. The light emitting element holder 18 to which the light emitting element 1 is attached is held by the chuck claws 14 after loosening the fixing screw 19. The lens holder 20 incorporating the light projecting lens 2 is held by loosening the set screw 21 and fitting the shift claw 17.

A beam profiler 23 is fixed to one end of the base 7 by a support 22. The beam profiler 23 is a measuring device that detects the diameter of the light beam and the X and Y coordinates. FIG. 2 is a block diagram of the embodiment,
A control unit 24 such as a computer controls the operation of the Z motor 9, the Y motor 10, the X motor 12, and the S motor 15, controls the lighting of the light emitting element 1 via the amplifier 27, and controls the measurement of the beam profiler 23.

Reference numeral 25 denotes a keyboard, and 26 denotes a monitor, which interface with a worker under the control of the control unit 24. The operator operates the keyboard 25 and obtains information such as the operating state and the measurement result by displaying on the monitor 26. FIG. 3 is a principle diagram of the optical axis adjustment, and the operation of the embodiment will be described by using this diagram together. With the sensor of the optical displacement gauge set in the optical axis adjusting mechanism configured as described above, a starting operation is performed from the keyboard 25, the light emitting element 1 is turned on via the amplifier 27, and the Z motor 9 is driven to move the Z slider. After shifting, as shown in FIG. 3, the distance between the light projecting lens 2 and the beam profiler 23 is set to the B dimension, and the coordinate value b of the beam profiler 23 is read.

Next, the Z slider 8 is retracted, and further C
The coordinate value c of the beam profiler 23 is read at the positions separated by the dimension. Since A, B, and C are known values, the inclination θ of the optical axis
= Tan ⁻¹ (c−b) / C. The positional deviation of the light emitting element 1 is a = Atan θ. Since the beam profiler 23 can measure the coordinate values in the X and Y directions, the positional deviation a can be calculated in the X and Y directions.

Based on the measurement result, the control unit 24 determines that the X motor 12
And the Y motor 10 are driven to move the X slider 13 and the Y slider 11, respectively, and the light emitting element 1 is moved in the reference optical axis direction shown in FIG. 3 by a positional displacement dimension corresponding to each of the X and Y directions. Then, as described above, the beam profiler 23 measures the coordinates of the two points again, and confirms that the difference is within the standard range. The control unit 24 displays the measurement result on the monitor 26, and displays an instruction to tighten the fixing screw 19 on the monitor 26.

According to the instruction, the operator tightens the fixing screw 19 to fix the light emitting element holder 18. Next, the diameter of the light beam is adjusted. The light beam diameter should be as small as possible in order to measure a narrow portion or perform precise measurement. Loosen the setscrew 21 that secures the lens holder 20 to the keyboard 2
When the next starting operation is performed from 5, the control unit 24 causes the Z motor 9
Is driven to move the Z slider 8, and the distance between the light projecting lens 2 and the beam profiler 23 is adjusted to the minimum beam diameter setting position.

The S motor 15 is driven, the S slider 16 is shifted, and the beam profiler 23 measures the beam diameter. Repeat this operation to find the position where the minimum beam diameter is reached. At the position where the minimum beam diameter is within the standard range,
The control unit 24 displays the measurement result and the instruction to tighten the set screw 21 on the monitor 26. The worker tightens the setscrew 21 and performs an end operation from the keyboard to complete the optical axis adjustment.

By using the optical axis adjuster of this embodiment as described above, Since the optical axis can be adjusted parallel to the sensor base 6, there is less variation in the position of the received light beam, and adjustment of the position detection element is unnecessary. 2. Since the sensors are compatible, the combination with the amplifier is free. 3. Even in the position measurement in the direction perpendicular to the optical axis, the measurement error is small, and accurate measurement can be performed.

The adjustment of the optical axis and the adjustment of the beam diameter described in this embodiment can be automatically executed under the control of the control section 24, and can be performed manually or partially manually. You can also

[0022]

As described above in detail, the light emitting element adjusting means and the distance adjusting means have the effect that the deviation of the optical axis can be accurately detected and the optical axis can be adjusted correctly. Further, there is an effect that the beam diameter of the light beam can be adjusted to an appropriate value by the light projecting lens adjusting means.

[Brief description of drawings]

FIG. 1 is a perspective view of an optical axis adjusting mechanism section according to an embodiment.

FIG. 2 is a block diagram of an embodiment.

[Figure 3] Principle diagram of optical axis adjustment

[Fig. 4] Principle of measurement in the optical axis direction of the optical displacement meter

FIG. 5: Principle of measurement of the optical displacement meter in the perpendicular direction

FIG. 6 is an explanatory diagram showing the influence of optical axis shift in the optical axis direction.

FIG. 7 is an explanatory diagram showing the influence of optical axis shift in the perpendicular direction.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 light emitting element 2 light projecting lens 3 measured object 5 position detecting element 8, 9 distance adjusting means 10-14 light emitting element adjusting means 15-17 light projecting lens adjusting means 23 beam profiler 24 control section

Claims (4)

[Claims] 1. A light emitting element that emits a light beam for projecting light onto a measurement object, a light projecting lens that inputs the light beam and projects light onto the measurement object, and receives reflected light from the measurement object. And a beam profiler for detecting a light beam from the light emitting element, a light emitting element adjusting means for correcting the position of the light emitting element of the optical displacement meter including a position detecting element for measuring the position of the object to be measured, An optical axis comprising a distance adjusting means for adjusting a distance between the profiler and the optical displacement meter, calculating a positional deviation of the light emitting element, correcting the position of the light emitting element, and adjusting the optical axis. Adjuster. 2. A light emitting element that emits a light beam for projecting light onto a measurement object, a projection lens that inputs the light beam and projects the light beam onto the measurement object, and receives reflected light from the measurement object. And a beam profiler for detecting a light beam from the light emitting element, a light emitting element adjusting means for correcting the position of the light emitting element of the optical displacement meter including a position detecting element for measuring the position of the object to be measured, The light emitting device includes a distance adjusting unit that adjusts a distance between the profiler and the optical displacement meter, and a control unit that controls the operation of the light emitting device adjusting unit and the distance adjusting unit and controls lighting of the light emitting device. An optical axis adjusting machine, which adjusts the optical axis by calculating the position shift of the light emitting element to correct the position of the light emitting element. 3. The distance adjusting means sets the distance between the light emitting element of the optical displacement meter and the beam profiler to a certain value, and measures the projection position of the light beam onto the beam profiler. Further, the distance between the light emitting element of the optical displacement gauge and the beam profiler is set to another value to measure the projection position of the light beam onto the beam profiler, and the difference between the two measurement results indicates that the light emitting element An optical axis adjuster characterized by calculating a position shift and correcting the position. 4. The light projecting lens adjusting means for correcting the position of the light projecting lens of the optical displacement gauge according to claim 1, claim 2 and claim 3, wherein the light projecting lens adjusting means is used to project the light. An optical axis adjuster characterized by adjusting the position of a lens to adjust the light beam diameter.