JP2002156208A - Optical displacement gauge and beam conversion attachment used for optical displacement gauge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical displacement gauge which can select and use a laser beam whose optical image takes a line shape and a laser beam whose optical image takes a spot shape when the laser beam hits an object. SOLUTION: The optical displacement gauge comprises a first projection optical system which generates a first laser beam whose optical image takes the line shape when the beam hits the object and a second projection optical system 3 which generates a second laser beam whose optical image takes the spot shape when the beam hits the object. The displacement gauge is constituted in such a way that either the first laser beam or the second laser beam hits the object. The second optical system 3 comprises a condenser lens 30 used to condense the first laser beam, and it is mounted on the outer face of a gage body 1 in which the first optical system is built in such a way that the condenser lens 30 is situated on the optical axis of the first optical system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a displacement meter used to measure the surface displacement of an object, the height of a projection, the depth and level of a groove or a depression, the thickness of an object, and the like. The present invention relates to an optical displacement meter that performs displacement measurement by irradiating a laser beam to an object and receiving light reflected by the object with a light receiving element, and a beam conversion attachment used in the optical displacement meter.

[0002]

2. Description of the Related Art Conventionally, as this type of displacement meter, there is a displacement meter in which a light projecting optical system and a light receiving optical system are integrated into an instrument body. The light projecting optical system includes a laser light source and a light projecting lens module, and a laser beam emitted from the laser light source passes through the light projecting lens module and is emitted from the light projecting window to the outside of the instrument body. On the other hand, the light-receiving optical system includes a light-receiving lens module and a light-receiving element such as a two-dimensional CCD. Is received at.

As a conventional optical displacement meter, a type using a laser beam whose light image hits an object has a line shape, and a type using a laser beam whose light image hits an object has a spot shape There is a type.

[0004]

The optical displacement meter of the former type can collectively measure the height of a projection, the depth of a groove or a dent or a step, and averages the influence of irregularities on the surface of an object. Although there is an advantage that the measurement can be performed, the laser beam may be irregularly reflected at a portion that is not a measurement target, and may adversely affect the measurement.

In the latter type of optical displacement meter, the above-mentioned irregular reflection is unlikely to occur, but the height of a projection, the depth of a groove or a dent, or a step cannot be measured at a time, and the influence of irregularities on the surface of an object is reduced. There is a problem that it is easy to receive.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problem, and it is possible to selectively use a laser beam having a line shape and a laser beam having a spot shape when an optical image hits an object. Accordingly, an object of the present invention is to provide an optical displacement meter capable of realizing optimal sensing.

Another object of the present invention is to provide a beam conversion attachment for an optical displacement meter that measures displacement using a laser beam whose light image when hitting an object has a line shape. To provide.

[0008]

SUMMARY OF THE INVENTION An optical displacement meter according to the present invention measures a displacement by irradiating a laser beam to an object and receiving reflected light from the object with a light receiving element.
A first light projecting optical system that generates a first laser beam whose light image hits an object has a line shape, and a second laser beam that has a light image hitting the object having a spot shape And a second light projecting optical system that generates at least one of the first and second light projecting optical systems,
One of the first and second laser beams is directed to the object.

The first light projecting optical system and the second light projecting optical system may be separate and independent, or may share a part of the configuration. To function at least one of the first and second light projecting optical systems means to function only the first light projecting optical system, to function only the second light projecting optical system, and to perform first light projecting. The case where both the optical system and the second light projecting optical system are made to function is included. If both the first light projection optical system and the second light projection optical system are to function, the first
And a second laser beam are generated, and either one of the laser beams is applied to the object.

According to the present invention, it is possible to select and use one of the first laser beam having a line-shaped light image and the second laser beam having a spot-shaped light image upon hitting an object. Thus, optimal sensing according to the application can be realized.

In a preferred embodiment of the present invention, the second light projecting optical system includes a condenser lens for condensing the first laser beam, and the first light projecting optical system is incorporated therein. The condenser lens is mounted on the outer surface of the instrument main body so that the condenser lens is positioned on the optical axis of the first light projecting optical system.

In the optical displacement meter according to this embodiment, when the first laser beam whose light image hits the object has a linear shape, the condensing lens is connected to the first light projecting optical system. By retreating from the optical axis, only the first light projecting optical system functions. In the case where the second laser beam having a spot-shaped light image when hitting the object is used, the first and second light beams are positioned by positioning the condenser lens on the optical axis of the first light projecting optical system. The second light projecting optical system is operated.

In order to quickly respond to a user's request for a product having a different laser safety standard class, a light shielding plate for blocking the passage of a laser beam is provided in the second light projecting optical system in order to ensure safety. May be provided, and a filter for attenuating the optical power of the laser beam may be provided in order to set a desired class.

In another embodiment of the present invention, each of the first and second light projecting optical systems comprises a first laser beam and a second laser beam.
Are arranged so that one of the laser beams passes through the half mirror and the other is reflected by the half mirror.

In the optical displacement meter according to this embodiment, when the first laser beam whose light image hits the object has a line shape, only the first light projecting optical system is operated, The first laser beam passes through a half mirror and strikes an object. In the case where the second laser beam is used, in which the light image that strikes the object has a spot shape, only the second light projecting optical system is operated, and the second laser beam is reflected by the half mirror to be used. Hit the object.

The above-mentioned second light projecting optical system is a beam conversion attachment externally attached to an optical displacement meter for performing displacement measurement using a laser beam whose light image when hitting an object has a line shape. And can be supplied to the market independently of the optical displacement meter. That is, a beam conversion attachment according to another aspect of the present invention includes a light-projecting optical system that generates a laser beam whose light image when hitting an object has a line shape, and a light-receiving optical system that receives reflected light of the laser beam at the object. For an optical displacement meter having a built-in element, it is externally mounted on a light projecting window of the optical displacement meter, and the laser beam emitted from the light projecting window is focused by a focusing lens. And a light projecting optical system for converting a light image upon hitting the target object into a second laser beam having a spot shape, and the condensing lens is provided with a light projecting optical system built in an optical displacement meter. It can be fixed on the light projecting window so as to be located on the optical axis, and can be detached from the light projecting window.

The light projecting optical system of the beam conversion attachment may include a light shielding plate for blocking the passage of the laser beam, and may include a filter for attenuating the optical power of the laser beam.

[0018]

FIG. 1 shows an internal configuration of an optical displacement meter according to an embodiment of the present invention. In the illustrated optical displacement meter, a first light projecting optical system 2 and a light receiving optical system 4 are integrated into an instrument main body 1. The first light projecting optical system 2 includes a laser light source 20 composed of a visible light semiconductor laser and a light projecting lens module 21 composed of a slit plate and a light projecting lens, and projects a laser beam emitted from the laser light source 20. The light passes through the optical lens module 21 and is emitted from the light projecting window 22 to the outside of the instrument body 1.

The light receiving optical system 4 includes a light receiving lens module 40 formed of a plurality of light receiving lenses and a light receiving element 41 formed of a two-dimensional CCD. 1, is received by the light receiving element 41 after passing through the light receiving lens module 40.

Hereinafter, the laser beam generated by the first light projecting optical system 21 is referred to as "first laser beam LB1". As shown in FIG. 1, the first laser beam LB1 is applied to the object 10 as it is, or after passing through the second light projecting optical system 3 shown in FIGS. The object 10 is irradiated. Hereinafter, the laser beam generated by the second light projecting optical system 3 is referred to as “second laser beam LB2”.

The first laser beam LB1 is shown in FIG.
As shown in (2), it is a band-shaped laser beam that gradually expands in the forward direction, and the beam thickness d becomes the thinnest at the center position c of the measurement distance area S. First laser beam LB1
Strikes the object 10 positioned in the measurement target area S, a line-shaped light image 11 is generated on the surface of the object 10. FIG. 5A shows the first laser beam LB1.
Is a plan view, and FIG. 5B is a view of the first laser beam LB1 viewed from a side.

The second laser beam LB2 is shown in FIG.
As shown in (2), it is a laser beam having a narrow axis shape, and the diameter r becomes the smallest at the center position c of the measurement distance area S. When the second laser beam LB2 hits the object 10 positioned in the measurement target area S, the object 10
A light image 11 in the form of a spot is generated on the surface of. FIG. 6A is a plan view of the second laser beam LB2, and FIG. 6B is a view of the second laser beam LB2.
It is the figure which looked at from the side. In FIG. 1, reference numeral 3 denotes a second light projecting optical system externally attached to the instrument main body 1.

FIGS. 2 to 4 show examples of the configuration of the second light projecting optical system 3 mounted on the outer surface of the instrument main body 1. The second of the illustrated example
The light projecting optical system 3 includes a plate-shaped holder 31, a condensing lens 30 composed of a cylindrical lens for condensing the first laser beam LB1, and a light shielding plate 5 for blocking the passage of the first laser beam LB1. And is incorporated. The holder 31 is fixedly fastened by four screws 32a to 32d so as to be detachable at the position of the light emitting window 22 on the outer surface of the instrument main body 1. The light projecting window 22 is circular, and when the holder 31 is mounted on the instrument main body 1, the condenser lens 30 is positioned on the optical axis of the first light projecting optical system 2 passing through the center of the light projecting window 22.
Is located.

When performing displacement measurement using the second laser beam LB2, the second light projecting optical system 3 is mounted on the outer surface of the instrument body 1 so as to cover the light projecting window 22. First
When performing displacement measurement using the laser beam LB1 of
Remove all four screws 32a-32d and remove holder 31 from instrument body 1, or remove one other screw 32d and remove the other three screws 32a-32c, as shown by the dashed line in FIG. Then, the holder 31 is turned by 90 degrees and retreated, and the light emitting window 22 is opened.

The slide plate 5 is provided on the plate surface of the holder 31.
Rectangular support hole 33 that freely slides up and down 0
And a mounting hole 34 which is fixed so that the condenser lens 30 is fitted therein. The mounting hole 34 has a circular light transmitting hole 3 through which the first laser beam LB1 passes.
5 are provided.

A mounting hole 52 is formed in the slide plate 50, and the light shielding plate 5 is fitted into the mounting hole 52, and the light shielding plate 5 is fixed thereon by a holding plate 54. This slide plate 50 has
Instead of the light shielding plate 5, a filter for attenuating the optical power of the laser beam can be attached. For this purpose, the slide plate 50 and the holding plate 54 are provided with circular light transmitting holes 51 and 53, respectively. is there.

The slide plate 50 is disposed between the instrument main body 1 and the holder 31. A knob 55 is bent at the upper end of the slide plate 50, and the knob 55 is slidably supported by the support holes 33 of the holder 31. When the knob 55 is at the lower end of the support hole 33, the light blocking plate 5 blocks the optical path, and when the knob 55 is at the upper end of the support hole 33, the light shield 5 opens the optical path. The above-mentioned second light projecting optical system 3 is used as a beam conversion attachment externally attached to an optical displacement meter that performs displacement measurement using a laser beam whose light image when hitting an object has a line shape. And can supply to the market independently.

In the above embodiment, the first laser beam LB
1 is used, only the first light projecting optical system 2 is operated, and when the second laser beam LB2 is used, the second light projecting optical system is placed on the optical axis of the first light projecting optical system 2. Although the first light projecting optical system 2 and the second light projecting optical system 3 function by locating the third condenser lens 30, the present invention is not limited to this, and the first laser beam LB 1 is used. In this case, only the first light projecting optical system 2 is operated, and the second laser beam LB
In the case of using 2, it is also possible to configure so that only the second light projecting optical system 3 functions.

FIG. 7 shows the first and second light projecting optical systems 2 and 3.
Shows another configuration example of the first laser beam LB1.
Passes through the half mirror 6, and the second laser beam LB
Reference numeral 2 is such that the first light projecting optical system 2 and the second light projecting optical system 3 are arranged at an angle position orthogonal to each other with respect to the half mirror 6 so that the light is reflected by the half mirror 6. In the drawing, reference numeral 1 denotes a main body of the instrument, and first and second light projecting optical systems 2 and 2.
Reference numeral 3 is incorporated in the instrument main body 1.

The first light projecting optical system 2 includes a first laser light source 2
0 and the first light projecting lens module 21,
The second light projecting optical system 3 is connected to the second laser light source 37 and the second
And a light projecting lens module 38. When using the first laser beam LB1, the first laser light source 2
0 is driven to make only the first light projecting optical system 2 function. Thus, the first laser beam LB1 passes through the half mirror 6 and irradiates the target. On the other hand, when the second laser beam LB2 is used, the second laser light source 37
And only the second light projecting optical system 3 functions. As a result, the second laser beam LB2 is reflected by the half mirror 6 and irradiated on the target.

In order to selectively drive the first laser light source 20 and the second laser light source 37, a changeover switch 60 is provided on the outer surface of the instrument main body 1, and the changeover switch 60 is provided inside the instrument main body 1. The first,
A selection circuit 60 that outputs a drive signal to one of the second laser light sources 20 and 37 is incorporated.

FIG. 8 shows the first and second light projecting optical systems 2 and 3.
FIG. 7 shows another configuration example of the first embodiment, similar to the embodiment of FIG.
Laser beam LB1 passes through half mirror 6, and second laser beam LB2 is reflected by half mirror 6 so that first laser light source 20
And the second laser light source 37 are arranged at angular positions orthogonal to each other.

In this embodiment, the second laser beam LB
2 passes the laser beam emitted from the second laser light source 37 through the slit hole 39a of the slit plate 39, and then passes the passing light through the light projecting lens module 21 of the first light projecting optical system 2. It is generated by. Accordingly, the light projecting lens module 21 constitutes the first light projecting optical system 2 and also constitutes the second light projecting optical system 3. A changeover switch 6 as a configuration for selectively driving the first laser light source 20 and the second laser light source 37
The provision of 0 and selection circuit 60 is the same as in the embodiment of FIG.

In the optical displacement meter of the embodiment shown in FIGS. 1 to 4, when the first laser beam LB1 whose light image hits the object 10 has a linear shape, the outer surface of the instrument body 1 is used. After the second light projecting optical system 3 is not mounted on the first light projecting optical system 3 or the second light projecting optical system 3 mounted thereon is retreated and the light projecting window 22 is opened, the laser light source of the first light projecting optical system 2 is opened. 2
Drive 0. The laser beam emitted from the laser light source 20 passes through the light projecting lens module 21, is emitted from the light projecting window 22 to the outside of the instrument main body 1, and hits the object 10.
The light reflected on the surface of the object 10 is taken into the instrument body 1 through the light receiving window 42 and
And is received by the light receiving element 41.

Next, when using the second laser beam LB2 in which the light image hitting the object 10 has a spot shape, the second laser beam LB2 is placed at the position of the light projecting window 22 on the outer surface of the instrument main body 1.
After the light projecting optical system 3 is mounted, the laser light source 20 of the first light projecting optical system 2 is driven. The laser beam emitted from the laser light source 20 passes through the light projecting lens module 21, goes out of the instrument main body 1 through the light projecting window 22, and passes through the condenser lens 30 of the second light projecting optical system 3. The object 10 is hit. The light reflected on the surface of the object 10 is taken into the instrument main body 1 through the light receiving window 42, passes through the light receiving lens module 40, and is received by the light receiving element 41.

In the optical displacement meter of the embodiment shown in FIG. 7, when the first laser beam LB1 is used, the changeover switch 61 is operated to drive the first laser light source 20, and the first light projection optical system is operated. Only system 2 works. First laser light source 20
The laser beam emitted by the light emitting lens module 21
Then, the light passes through the half mirror 6, is emitted from the light projecting window 22 to the outside of the instrument main body 1, and hits the object 10.

When using the second laser beam LB2, the changeover switch 61 is operated to operate the second laser beam source 37.
To make only the second light projecting optical system 3 function. Second
The laser beam emitted from the laser light source 37 passes through the light projecting lens module 38 and is reflected by the half mirror 6,
The object 1 is irradiated from the light emitting window 22 to the outside of the instrument body 1.
Hits zero.

In the optical displacement meter of the embodiment shown in FIG. 8, when the first laser beam LB1 is used, the changeover switch 61 is operated to turn on the first laser light source 20 of the first light projecting optical system 2. Drive. The laser beam emitted from the first laser light source 20 passes through the half mirror 6 and the light projecting lens module 21, is emitted from the light projecting window 22 to the outside of the instrument main body 1, and hits the object 10.

When using the second laser beam LB2, the changeover switch 61 is operated to drive the second laser light source 37 of the second light projecting optical system 2. Second laser light source 3
The laser beam emitted at 7 is reflected by the half mirror 6, passes through the light projecting lens module 21, is irradiated from the light projecting window 22 to the outside of the instrument main body 1, and hits the object 10.

[0040]

According to the present invention, it is possible to selectively use a laser beam having a line shape and a laser beam having a spot shape in an optical image of a laser beam when the laser beam hits an object. Optimal sensing according to the application can be realized.

[Brief description of the drawings]

FIG. 1 is a partially broken perspective view showing the internal structure of an optical displacement meter according to one embodiment of the present invention.

FIG. 2 is an exploded perspective view showing a second light projecting optical system mounted on the outer surface of the instrument main body of FIG.

FIG. 3 is a front view showing a state where a second light projecting optical system is mounted on an outer surface of the instrument main body of FIG. 1;

FIG. 4 is a side view showing a cross section of a second light projecting optical system mounted on the outer surface of the instrument main body of FIG. 1;

FIG. 5 is an explanatory diagram showing a form of a first laser beam and a shape of an optical image formed by the first laser beam.

FIG. 6 is an explanatory diagram showing a form of a second laser beam and a shape of an optical image formed by the second laser beam.

FIG. 7 is an explanatory diagram showing another configuration example of the first and second light projecting optical systems.

FIG. 8 is an explanatory diagram showing another configuration example of the first and second light projecting optical systems.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Instrument main body 2 1st projection optical system 3 2nd projection optical system 5 Shield plate 30 Condensing lens 6 Half mirror

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hiroki Nakajima 801 Minami-Fudo-cho, Higashi-iri, Horikawa, Shiokoji-dori, Shimogyo-ku, Kyoto 2F065 AA03 AA06 AA24 AA25 BB05 FF09 GG04 HH04 HH05 HH13 JJ03 JJ08 JJ08 JJ26 LL00 LL08 LL24 PP12 UU01 2F112 AA09 BA03 CA06 DA06 DA25 DA32 DA40

Claims (8)

[Claims] 1. An optical displacement meter for measuring a displacement by irradiating a laser beam on an object and receiving reflected light from the object with a light receiving element, wherein an optical image when hitting the object has a line shape. A first light projecting optical system that generates a first laser beam, and a second light projecting optical system that generates a second laser beam whose light image when hitting an object has a spot shape. , At least one of the first and second light projecting optical systems is functioned,
An optical displacement meter adapted to hit any one of the second laser beams on an object. 2. The second light projecting optical system includes a condensing lens for condensing the first laser beam, and an outer surface of an instrument main body in which the first light projecting optical system is incorporated. 2. The optical displacement meter according to claim 1, wherein the condenser lens is mounted such that the condenser lens is located on an optical axis of the first light projecting optical system. 3. The optical displacement meter according to claim 1, wherein the second light projecting optical system is provided with a light shielding plate for blocking passage of a laser beam. 4. The optical displacement meter according to claim 1, wherein a filter for attenuating the optical power of the laser beam is provided in the second light projecting optical system. 5. The first and second light projecting optical systems are arranged such that one of the first laser beam and the second laser beam passes through a half mirror and the other is reflected by the half mirror. The optical displacement meter according to claim 1, wherein: 6. An optical system incorporating a light projecting optical system for generating a laser beam whose light image upon hitting an object has a line shape and a light receiving element for receiving reflected light of the laser beam on the object. For a displacement meter, a beam conversion attachment externally provided on a light emitting window of the optical displacement meter, and the laser beam emitted from the light emitting window is condensed by a condensing lens to an object. A light projecting optical system that converts the light image upon impact into a second laser beam having a spot shape, and the condensing lens is positioned on the optical axis of the light projecting optical system built in the optical displacement meter. A beam conversion attachment configured to be fixed on the light emitting window and to be detachable from the light emitting window. 7. A light projection optical system for beam conversion includes a light shielding plate for blocking passage of a laser beam.
Beam conversion attachment described in. 8. The beam conversion attachment according to claim 6, wherein the light projecting optical system for beam conversion includes a filter for attenuating the optical power of the laser beam.