JPH05187832A - Measuring device - Google Patents

Abstract

PURPOSE:To reduce the occurrence of errors resulting from the thickness of a plane-parallel reflecting mirror of a measuring instrument using the reflecting mirror having reflecting surfaces on both sides. CONSTITUTION:The title measuring instrument is equipped with a measuring optical system 4 which emits a bundle of measuring rays of light from a light source 3 toward an object 2 to be measured and a light receiving optical system 5 which leads a bundle of scattered rays of light reflected by the surface of the object 2 to a light receiving section 6 and a first mirror 4A which reflects the bundle of measuring rays of light from the light source 3 is installed to the optical system 4. Then a second mirror 5A which reflects the bundle of scattered rays of light reflected on the surface of the object 2 is installed to the optical system 5 and the mirrors 4A and 5A are respectively constituted by using the front and rear reflecting surfaces of a double-faced reflecting mirror M. The reflecting mirror M is constituted by forming its reflecting surfaces on one surface of a transparent substrate M1 only.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring optical system for irradiating a measuring light beam from a light source toward an object to be measured, and a scattered light beam flux reflected from the surface of the object to be measured out of the measuring light beam. A light-receiving optical system that leads to a light-receiving unit, the measurement optical system is provided with a first mirror that reflects a measurement light flux from a light source toward an object to be measured, and the light-receiving optical system includes the A second mirror for reflecting the scattered light flux reflected from the surface of the object to be measured toward the light receiving portion is provided, and the first mirror and the second mirror are separately used for the front and back reflecting surfaces of the double-sided reflecting mirror. It relates to a configured measuring device.

[0002]

2. Description of the Related Art As a measuring device of this type, the first mirror and the second mirror are constructed by separately using both surfaces of a parallel flat substrate having reflective surfaces formed on both front and back surfaces. For example, CAD that finishes the final design drawing by inputting the external shape from a molding die or model of various designed products.
For data input devices, 3D image data input devices used for education and sales, medical diagnostic devices, and tertiary shape measuring devices used as robot vision sensors, refer to the measurement light flux from the light source. A measurement optical system that scans toward an object to be measured on a surface, a light receiving optical system that guides a scattered light beam reflected from the surface of the object to be measured among the measurement light beam bundles to a light receiving unit, and the light receiving unit And a signal processing unit that calculates and derives the distance of the surface of the object to be measured from the reference surface based on the detection output of the scattered light flux, and the measurement optical system scans the projection light flux from the light source. And a first fixed mirror that reflects a projection light beam scanned by the first movable mirror toward the object to be measured, and the optical system for receiving light is the object to be measured. Surface or And a second movable mirror that guides the scattered light flux reflected by the second fixed mirror to the light receiving unit, the first movable mirror and the second movable mirror. The second movable mirror is configured by separately using both surfaces of a parallel flat substrate having reflection surfaces on both front and back surfaces.

[0003]

However, according to the above-mentioned prior art, as shown in FIG. 6, the first (movable) mirror 4A and the second (movable) mirror 4B have reflective surfaces on both front and back surfaces. Since the reflecting surfaces S1 and S2 formed on both surfaces of the formed parallel flat substrate M1 are separately used, the scattered light flux H2 detected by the light receiving unit is the measurement light flux H1 emitted from the light source. On the other hand, there is a disadvantage in that the deviation is ΔL due to the thickness d ₀ of the plane-parallel substrate, and this deviation appears as a detection error. In particular, this deviation ΔL differs as the mirror rotates and the incident angle changes. In order to eliminate this drawback, it is conceivable to reduce the thickness of the plane-parallel substrate to reduce the deviation. In this case,
There is a limit because the flatness of the substrate may not be guaranteed. An object of the present invention is to eliminate the above-mentioned conventional drawbacks.

[0004]

In order to achieve this object, the characteristic configuration of the measuring apparatus according to the present invention is that a double-sided reflecting mirror is formed by forming a reflecting surface only on one surface of a transparent substrate. It is in.

[0005]

If the first (movable) mirror and the second (movable) mirror are constructed by separately using both surfaces of the reflecting surface formed on only one surface of the transparent substrate, the measurement light beam bundle or the scattered light beam bundle can be obtained. One of them will pass through a transparent substrate (for example, optical glass or the like) when being reflected by the reflecting surface. in this case,
As shown in FIG. 1, a ray bundle that passes through a transparent substrate having a thickness of d ₀ , is reflected by a reflecting surface, and then passes through the transparent substrate again, is substantially due to the difference in refractive index between air and the transparent substrate. Specifically, the same difference as when reflected from a reflection mirror in which reflection surfaces are formed on both surfaces of a substrate having a thickness d ₁ smaller than the thickness d ₀ occurs.
That is, the same effect can be obtained as if a mirror is formed on a substrate having a smaller thickness d ₁ , while the substrate is made of a substrate having a thickness d ₀ necessary to secure sufficient flatness.

[0006]

As described above, according to the present invention, the deviation between the measurement light beam bundle and the scattered light beam flux due to the thickness of the plane-parallel substrate is reduced while ensuring the thickness that ensures the flatness of the substrate. It has become possible to provide a measuring device that can do this.

[0007]

EXAMPLES Examples will be described below. As shown in FIG. 3, a three-dimensional shape measuring apparatus, which is an example of a measuring apparatus, includes a light source 3 that outputs a spot light by providing a laser oscillator, and a measurement light flux from the light source 3 on an XY reference plane 1. DUT 2
Measuring optical system 4 that scans in the X direction toward, a light receiving unit 6 that detects the scattered light beam bundle reflected from the surface of the DUT 2 among the measurement light beam bundles, and the scattered light beam bundle in the light receiving unit 6. An optical system unit U including a light receiving optical system 5 for guiding, and a signal processing unit for calculating and deriving the distance of the surface of the DUT 2 from the reference surface 1 based on the detection output of the scattered light flux by the light receiving unit 6. 7, a measurement control unit 8 for controlling the optical system unit U, a model for generating a shape model of the DUT 2 from the X, Y, Z three-dimensional data obtained from the signal processing unit 7 and the measurement control unit 8. It is configured with the generation unit 9.

The measuring optical system 4 reflects a first movable mirror 4A which scans the measuring light beam from the light source 3 and the measuring light beam scanned by the first movable mirror 4A toward the object 2 to be measured. The second fixed mirror 5B, which is composed of the first fixed mirror 4B, reflects the scattered light flux from the surface of the DUT 2 and the scattered light reflected by the second fixed mirror 5B. The second movable mirror 5A that guides the bundle to the light receiving unit 6 and the imaging lens 5C that converges the scattered light beam bundle reflected by the second movable mirror 5A at the light receiving unit 6 are included.

The first movable mirror 4A and the second movable mirror 5
As shown in FIG. 1, A is a double-sided reflecting mirror M having a reflecting surface S formed by aluminum coating on only one surface of a transparent substrate M1, and a motor MO for rotating the double-sided reflecting mirror M.
It is composed of T and. That is, both surfaces of the reflecting surface S are the reflecting surfaces of the different mirrors 4A and 5A.

The measurement controller 8 rotates the motor MOT to scan the measurement light beam bundle in the X direction, and also moves the optical system unit U in the Y direction to scan the ZY plane.
As shown in FIG. 2, the signal processing unit 7 detects the distance X ₀ X detected by the light receiving unit 6 including the one-dimensional image sensor CCD.
_{Since 1} is proportional to ΔX ₀ and the surface position Z ₀ of the measurement object 2 from the reference plane 1 has a relationship of Z ₀ · θ = ΔX _0, Z ₀ is obtained. That is, theoretically, the detected ray bundle reflected by the reference plane 1 is always the point X _{0 in the} figure.
Will be focused on. The model generation unit 9 grasps the measurement point on the XY plane from the rotation angle of the first movable mirror 4A and the second movable mirror 5A (rotation angle of the motor MOT) by the measurement control unit 8, and the signal processing unit 7 A shape model of the DUT 2 is generated from the derived Z coordinate at the point.

Another embodiment of the present invention will be described below. Although the scanning mechanism of the optical system unit U in the Y-axis direction is not described in detail in the previous embodiment, this may be configured using an existing technique, for example, a driving mechanism such as a motor and a pulley.
The double-sided reflection mirror M has a measurement light flux on either of its front and back surfaces,
Alternatively, it may be used for the scattered light flux. The configuration of the optical system unit U is not limited to this configuration, and any configuration may be used as long as it derives three-dimensional coordinates based on the principle described in the previous embodiment. For example, as shown in FIG. The movable mirrors 4A and 5A in the previous embodiment may be fixed and the first fixed mirror 4B may be rotated to scan the measurement light beam bundle. As shown in FIG. In order to scan the plane formed by the bundle and the scattered ray bundle in the Y-axis direction, a reflecting mirror rotatable about an axis parallel to the X-axis may be provided. Although the three-dimensional shape measuring device is used as the measuring device in the above embodiment, the measuring device is not limited to this and can be used for other measuring devices such as a distance measuring device.

It should be noted that although reference numerals are given in the claims for convenience of comparison with the drawings, the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a main part showing the principle.

FIG. 2 is an explanatory diagram of a main part showing the principle.

[Fig. 3] Overall configuration diagram of the three-dimensional shape measuring apparatus

FIG. 4 is an overall configuration diagram of a three-dimensional shape measuring apparatus showing another embodiment.

FIG. 5 is an overall configuration diagram of a three-dimensional shape measuring apparatus showing another embodiment.

FIG. 6 is an explanatory diagram showing the principle of the main part of a conventional example.

[Explanation of symbols]

 1 Reference surface 2 Object 3 Light source 4 Projection optical system 4A First movable mirror 4B First fixed mirror 5 Light receiving optical system 5A Second movable mirror 5B Second fixed mirror 6 Light receiving unit 7 Signal processing unit

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Hideki Wakai, 75-1 Hasunumacho, Itabashi-ku, Tokyo Topcon Co., Ltd. (72) Inventor, Kazuhiko Enomoto 75-1 Hasunumacho, Itabashi-ku, Tokyo Topcon Co., Ltd. Within

Claims (2)

[Claims] 1. A measuring optical system (4) for scanning a measuring light beam from a light source (3) toward an object to be measured (2) on a reference surface (1); Measured object (2)
A light receiving optical system (5) for guiding the scattered light flux reflected from the surface to a light receiving portion (6), and the object to be detected from the reference surface (1) based on the detection output of the scattered light flux by the light receiving portion (6). A signal processing unit (7) for calculating and deriving the distance of the surface of the measurement object (2), and the first optical system (4) for scanning the measurement light beam from the light source (3). A movable mirror (4A) and a first fixed mirror (4) that reflects the measurement light flux scanned by the first movable mirror (4A) toward the object to be measured (2).
B) and the light receiving optical system (5)
A second fixed mirror (5B) that reflects the scattered light beam from the surface of the object (2) to be measured, and the second fixed mirror (5B).
And a second movable mirror (5A) for guiding the scattered light flux reflected by B) to the light receiving section (6), and the first movable mirror (4A) and the second movable mirror (5).
A) is a measuring device in which the front and back reflecting surfaces of the double-sided reflecting mirror (M) are separately used, and the double-sided reflecting mirror (M) is provided only on one surface of the transparent substrate (M1). A measuring device configured by forming a reflecting surface. 2. A measuring optical system (4) for irradiating a measuring light flux from a light source (3) toward an object (2) to be measured, and a surface of the object (2) to be measured among the measuring light flux. A light receiving optical system (5) for guiding the reflected scattered light beam to the light receiving section (6) is provided, and the measurement light beam from the light source (3) is supplied to the measurement object (2) in the measurement optical system (4). ) Is provided and a first mirror (4A) for reflecting the light is provided, and the light receiving optical system (5) is provided.
Secondly, a second mirror (5A) that reflects the scattered light flux reflected from the surface of the DUT (2) toward the light receiving section (6).
And a first mirror (4A) and a second mirror (5A) are separately configured by using the front and back reflecting surfaces of the double-sided reflecting mirror (M). A measuring device in which a mirror (M) has a reflecting surface formed only on one surface of a transparent substrate (M1).