JPS63206602A - Shape measuring apparatus - Google Patents

Abstract

PURPOSE:To facilitate the coaxial adjustment of two laser beams by a method wherein one laser beam is divided by a half mirror and one beam obtained by division is applied to one surface of a substance to be measured, while the other is reflected by the mirror and applied to the opposite-side surface of the substance. CONSTITUTION:A laser beam transmitted through a half mirror 20 is reflected on the upper surface 2 of a substance 1 to be measured and then formed into an image at a point (a) on CCD 31. When a substance 1a to be measured, which is thinner than the substance 1, is measured, on the other hand, the position of the upper surface thereof is lower than that of the substance 1, and so the beam advances as indicated by a broken line and formed into an image at a point (b) on CCD 31. In this way, the position of the upper surface of the substance to be measured is detected on the basis of the position of the image on CCD 31. The position of the lower surface 3 of the substance is measured in the same way, and the thickness of the substance 1 to be measured is determined by a control arithmetic element 50 and displayed in a display 60. The alignment of the axes of the laser beam advancing onto the upper surface 2 and that advancing onto the lower surface 3 requires only adjustment of mirrors 41-43, and thus the adjustment thereof is facilitated.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a shape measuring device.

[Prior Art] As a conventional device for measuring the thickness of films, plate-like objects, etc., the device shown in FIG. 4 is known.

In this conventional device, a laser 10a is provided on the upper surface 2 side of a plate-shaped object to be measured, and a laser 10a is provided on the lower surface 3 side of the object to be measured 1.
b is provided. The CCD 31 detects the light reflected by the laser beam from the laser 10a on the object to be measured 1, and the C0D 32 detects the light reflected by the laser beam from the laser 10b on the object to be measured 1. Measured object 1 and CCD31.32
Imaging lenses 33 and 34 are provided between the two.

In this conventional device, the laser beam from the laser 10a is reflected by the object to be measured 1, and this reflected light forms an image on the CCD 31. However, if the position of the upper surface 2 of the object to be measured is different, the CCD 3
The imaging position on 1 is also different.

The position of the upper surface 2 of the object to be measured 1 is detected according to this imaging position. Similarly, the position of the lower surface 3 is detected, and the thickness of the object to be measured 1 is measured based on the detected positions of the upper surface 2 and the lower surface 3.

By the way, in the conventional device described above, it is troublesome to align (make coaxial) the optical axis of the laser beam from the laser 10a and the optical axis of the laser beam from the laser lOb.

[Problems to be Solved by the Invention] The conventional device described above has a problem in that the work of adjusting the laser beams from the two lasers so that they are coaxial with each other is complicated. Further, since the conventional device described above uses two lasers, there is a problem that it is expensive.

[Means for Solving the Problems] The present invention combines a single laser, divides the laser beam from this laser by a half mirror, and directs one of the divided beams by the half mirror to one surface of the object to be measured. The remaining light after being separated by a half mirror is reflected by a mirror to illuminate the opposite side of the object to be measured.

[Function] The present invention converts laser light from one laser into a half mirror.
One side of the light divided by the half mirror illuminates one side of the object to be measured, and the remaining light divided by the half mirror is reflected by the mirror to illuminate the other side of the object to be measured. Therefore, adjusting the mirrors is sufficient to adjust the two laser beams so that they are coaxial with each other, making the above adjustment work easier, and since only one laser is used, the entire device is cheap.

[Example] FIG. 1 is an explanatory diagram of an embodiment of the present invention.

In this embodiment, only one laser lO is provided to irradiate the object to be measured 1 with laser light, and a half mirror 20 is provided to separate the laser light from the laser lO.
The laser beam reflected by the mirror 20 is reflected by the mirrors 41, 42, and 43, and is irradiated onto the lower surface 3 of the object to be measured 1.

The CCD 31 passes through the half mirror 20 and detects the object to be measured 1.
The light reflected from the upper surface 2 is imaged by the imaging lens 33, and this image is detected.

In the CCD 32, the laser beam reflected by the half mirror 20 is reflected by the mirrors 41, 42, 43, and the light reflected by the lower surface 3 of the object to be measured 1 is imaged by the imaging lens 34, and this image is detected. It is.

Therefore, the CCD 31 receives one of the lights separated by the half mirror 20 and reflected on one surface of the object to be measured 1, and detects the position where the light is reflected on one surface of the object to be measured 1. This is an example of a first position sensor. mirror 41.4
2.43 is an example of a mirror that reflects the other light divided by the half mirror 20 and illuminates the other surface of the object to be measured.

The CCD 32 is guided by the mirror and the object to be measured l.
The light reflected from the other surface of the object is received and the other surface of the object to be measured is
The control calculation unit 50 calculates the thickness of the object to be measured 1 based on the detection data from the CCDs 31 and 32.
The display 60 is a device that digitally displays the calculated thickness.

Next, the operation of the above embodiment will be explained.

In the above embodiment, in FIG. 1, each member except the objects to be measured 1 and 1a is fixed after adjusting the direction. In other words, the laser beam 0, the CCD 31.32, the imaging lens 33.
34 and 5 are fixed to a housing (not shown), and the half mirror 2
0 and mirrors 41, 42, 43 are adjusted in their orientation. In this case, the laser beam from the laser 10 is combined with the light transmitted through the half mirror 20, the half mirror 20, and the mirror 4.
The directions are adjusted so that the lights reflected from 1 to 43 are coaxial with each other.

When measuring the object 1 to be measured, focusing on the upper surface 2 thereof, the laser beam transmitted through the half mirror 20 is reflected at the upper surface 2 of the object 1 to be measured, and then forms an image at point a of the CCD 31. On the other hand, when measuring an object to be measured 1a which is thinner than the object to be measured 1, the position of its upper surface is lowered, the light travels as shown by the broken line, and is imaged at point b of the CCD 31. In this way, C0D31
Since the upper imaging position is different, the position of the upper surface of the object to be measured can be detected based on the imaging position of the C0D 31.

When measuring the position (height) of the lower surface 3 of the object to be measured 1,
Same as above. In this way, the upper surface 2 of the object to be measured 1
and the position of the lower surface 3, and the control calculation section 50 determines the thickness of the object to be measured 1 based on the repositioned positions. This thickness is digitally displayed on the display 60. Of course, it may be displayed in analog form.

In the above embodiment, the laser beam is directed toward the upper surface 2 and the lower surface 3
Axis alignment with the laser beam directed toward is easy because it is only necessary to adjust the mirrors 41 to 43.

FIG. 2 is an explanatory diagram of a modification of the above embodiment.

When compared with the embodiment shown in FIG. 1, the embodiment shown in FIG.
Cylindrical lenses 71 and 72 are provided, a control calculation section 51 is provided in place of the control calculation section 50, and a CRT 61 is provided in place of the display 60.

As shown in FIG. 3, the cylindrical lens 71 is a lens that one-dimensionally spreads the laser beam from the laser 10, and the cylindrical lens 72 is a lens that converts this spread laser beam into parallel light. Therefore, the cylindrical lenses 71 and 72 are examples of cylindrical lenses that spread the laser light from the laser 0 and create a bar-shaped light beam. Further, the control calculation section 51 is an example of a control calculation means that calculates the shape and thickness of the object to be measured based on the signal from the first position sensor and the signal from the second position sensor.

The CRT 61 illustrates the shape of the front surface (unevenness) and the shape of the back surface (unevenness), and also displays the thickness graphically.

The basic operation of the embodiment shown in FIG. 2 is the same as that of the embodiment shown in FIG. 1, but by using cylindrical lenses 71 and 72, a shape on a straight line can be measured. Moreover, two-dimensional measurement can be performed by measuring while transporting the workpiece to be measured.

In the above embodiment, the m pass rate of the half mirror 20 is 40
%, the amount of light directed toward the upper surface 2 and the amount of light directed toward the lower surface 3 will be approximately equal, taking into account the loss at the mirrors 41 to 43. Further, in the above embodiment, the direction of the light emitted by the laser 10 is from top to bottom, but it may be emitted laterally. That is, the laser 10 may be installed sideways. In this case, it is necessary to add a total reflection mirror.

In the above embodiment, the laser beam is spread into a beam by the cylindrical lens 71, but in FIG. Good too. Even in this case, the shape of the object to be measured can be measured.

[Effects of the Invention] According to the present invention, since adjustment of the mirrors is sufficient for adjusting the two laser beams so that they are coaxial with each other, the above-mentioned adjustment work is easy.

Since only one laser is used, the entire device has the advantage of being inexpensive.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing one embodiment of the present invention. FIG. 2 is an explanatory diagram showing another embodiment of the present invention. Figure 3 shows the 2nd vI! It is a side view which shows the cylindrical lens part in the Example shown in J. FIG. 4 is an explanatory diagram of a conventional device. DESCRIPTION OF SYMBOLS 10... Laser, 20... Half mirror 1 31, 32... CCD, 41-43... Mirror, 50.51... Control calculation part, 61... CRT. Patent applicant: Japan Sensor Corporation Co., Ltd. Agent: Arata Yokubo - Figure 4

Claims (4)

[Claims] (1) One laser that irradiates the object to be measured with laser light; A half mirror that separates the laser beam; One of the lights separated by this half mirror is reflected by one surface of the object to be measured. a first position sensor that detects the position on the one surface of the object to be measured by receiving the light; a second position sensor that detects the position on the other surface of the object to be measured by receiving light guided by the mirror and reflected on the other surface of the object to be measured; Characteristic shape measuring device. (2) The shape measuring device according to claim 1, further comprising a cylindrical lens that spreads the laser beam from the laser and creates a bar-shaped light beam. (3) The shape measuring device according to claim 1, further comprising a scanning means for scanning laser light from the laser. (4) In claim 1, control calculation means for calculating the shape and thickness of the object to be measured based on the signal from the first position sensor and the signal from the second position sensor; , and display means for displaying the calculation results.