JPH02253112A - Form measuring instrument - Google Patents

Abstract

PURPOSE:To correct the disaccord between a face to be measured and a sensor movement face and to perform accurate measurement by providing a correction sensor, which is moved in the Z direction in accordance with a measuring sensor moved in X and Y directions, and a specular face as its reference. CONSTITUTION:Measuring sensors 4 and 4' are attached to a pair of arms 5 and 5' of an XY stage 3, and the lower arm 5' is provided with a correction sensor 6 which is moved in the Z direction in accordance with sensors 4 and 4'. A specular surface body 7 is set among three pole braces 11 on a sample stage 2 to constitute the reference face of the sensor 6. When measuring sensors 4 and 4' are moved in X and Y directions, fluctuation in the Z direction is caused between the face to be measured and the sensor movement face. This fluctuation in the Z direction is obtained by measuring the distance from the specular surface body 7 by the correction sensor 6 to correct the read value, thus correcting the disaccord between both reference faces to perform accurate measurement.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to the thickness, surface shape,
Alternatively, the present invention relates to a shape measuring device for measuring other external dimensions.

[Prior Art] Conventional shape measuring devices for measuring external dimensions such as the thickness of electronic parts, mechanical parts, etc. are used for measuring, for example, by moving an object set on a document table in X-Y and two directions. By scanning with a sensor, data on external dimensions such as thickness can be read. However, when using linear guidance to move in the X-Y direction, the following problem occurs.

In other words, when using rolling guides, the difference between the reference surface of the object to be measured set on the data table and the sensor for measurement may occur due to unevenness of the rolling surface of the rolling elements, surface roughness, intrusion of foreign objects, or accuracy deterioration due to wear. The reference plane in the scanning direction often did not match.

One possible way to improve this problem is to use static pressure guides, but it has been difficult to use because they are currently expensive and there are only a few types of commercially available products.

In the conventional shape measuring device, the correction is performed by obtaining the desired numerical value in advance by measuring a dummy etc. before measuring the target object to be measured, and then combining the empirical value with the actual measurement data. It was common to do this by comparing the

[Problems to be Solved by the Invention] However, in the conventional shape measuring device, when the rolling guide is used, there are differences in the repetitive motion depending on the rolling condition of the rolling elements. Therefore, when correction is applied to the measurement data, this value must be included in the measurement data, resulting in a decrease in measurement accuracy.

Therefore, the present invention was developed for the purpose of providing a shape measuring device that can completely eliminate the above-mentioned errors and obtain accurate measurement values.

[Means for Solving the Problem] That is, the shape measuring device of the present invention includes a data stand fixed to a base, and a contact type laser displacement meter that is held above and below the object to be measured and moves in the X-Y direction. A pair of measurement sensors consisting of a
It has a measurement unit consisting of a sensor for correcting directional fluctuations and a reference plane that serves as its reference.The object to be measured is set on a document stand with at least three points of support, and the measurement sensors installed above and below the x -By moving in the Y direction, the displacement data of the upper and lower surfaces of the object to be measured and the reference plane can be measured simultaneously.

[Example] Next, an example of the shape measuring device according to the present invention will be described based on the drawings.

In FIG. 1, reference numeral 1 denotes a base, on which a document stand 2 and an XY stage 3 are arranged side by side. The document table 2 includes three columns 11 and gripping claws 12 formed at the upper ends of the columns 1, and an object to be measured 13 is held between the claws 12. The three pillars 11 are movable in the vertical direction, and are each equipped with a sensor (not shown) for measuring the amount of movement.

Furthermore, a pair of arms extending above and below the object to be measured 13 are installed on the XY stage 3, each arm 5.5"
Measurement sensors 4 and 4' each consisting of a contact type laser displacement meter are attached to the X-Y
It is possible to move in the direction. In addition, on the 5° side of the lower arm, there is also a sensor 2 for interlocking with the sensor 4.4 for measurement described in 1.
A sensor 6 for correcting the direction fluctuation is attached, and the X
It is configured to move according to the drive of the Y stage 3. The measurement sensor 4.4'' and the variation correction sensor 6 can also be moved in the vertical direction, and are equipped with a sensor for measuring the amount of movement. This makes it possible to measure thickness data.

A mirror surface body 7 whose flatness is precisely set is installed between the three supports 11 of the data table 2 described in 1 above, and the reference plane formed by this mirror surface body 7 is used to correct the fluctuation in the X direction. The sensor 6 is configured to scan. 14 is an X-axis motor for driving the X stage, and 15 is an X-axis side encoder. Similarly, an X-axis motor for driving the Y stage and a Y-axis encoder are also attached, but they are not shown.

The measuring section C having the above configuration is as shown in FIG.
It is controlled by a processing unit consisting of a PU and the like. Peripheral equipment E such as a CRT, a printer, a /F output unit, and a floppy disk drive are attached to this processing unit. The shape measuring device of the present invention is comprised of the above-mentioned parts.

An object to be measured is measured using the shape measuring device. That is, in the processing section, first, the peripheral equipment E is used to set the conditions necessary for measurement. Then, the measuring section C is driven while being controlled by the processing section. The measurement is performed by continuously moving the measurement sensor 4.4 degrees in the X direction and reading data on the top and bottom surfaces of the object at preset measurement intervals. The above operations are then repeated to collect the set number of lines.

When performing the above measurements, the following operations are performed to correct for fluctuations in the measurement sensor 4.4" in two directions. In other words, when the measurement sensor 44" moves in the x-y direction during measurement, In this case, fluctuations occur in two directions with respect to the reference plane of the object to be measured.

The fluctuations in these two directions are corrected by the Z-direction fluctuation correction sensor 6 that works with the measurement sensors 4, 4, and the reference plane (mirror surface 7) that serves as the reference and the measurement sensors 4, 4°.
The distance between the two is measured and the above read value is corrected by calculation. As the reference plane used at this time, a plane made of a mirror surface 7 such as an optical flat is used. In addition, regarding the inclination of the original document table 2 and the reference plane, a reference document whose flatness has been confirmed is set on the document table 2 and measured in advance, and a correction value is obtained by comparison with this. .

The process for this correction will be explained based on FIG. 3. The sensor 16 in the figure is a simplified integral unit of a measurement sensor and a fluctuation correction sensor, and is located at distances B and B' from the reference plane. is read, and the difference is the amount of variation. Therefore, this amount of variation is added or subtracted from the read value A to correct the read value A°. Note that the read data or filed data during measurement is displayed as a graph or numerical value on the CRT, and R is displayed at the I/F output section.
Specified data is output via a communication line such as a 3-232C line. At the same time, numerical data is output to the printer.

[Effect of the invention 1 Since the shape measuring device of this invention is formed as described above,
Even if there is a mismatch between the reference plane of the object to be measured set on the document table and the reference plane in the scanning direction of the measurement sensor, the resulting error can be easily corrected, allowing highly accurate shape measurement. equipment can be provided.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of the shape measuring device according to the present invention, and is a perspective view of a measuring section, FIG. 2 is a schematic diagram showing the basic configuration, and FIG. 3 is a schematic diagram showing processing related to correction. 1...Base 2...Data stand 3...XY
Stage 4,4°...Measurement sensor 5.5°...
・Arm 6... Sensor for fluctuation correction 7... Mirror surface body 11... Support 12... Gripping claw 1
3...Object to be measured 14...X-axis motor C...Measuring section E...Peripheral device 15...X-axis circumferential encoder D...Processing section

Claims (1)

[Claims] 1. A pair of measurement sensors consisting of a data stand fixed to the base and a contact type laser displacement meter that is held above and below the object to be measured and moves in the X-Y direction, and works in conjunction with this measurement sensor. a sensor for correcting fluctuations in the Z direction;
It has a measurement part configured from a reference plane that serves as its reference,
By setting the object to be measured on a data stand with at least three points of support, and moving the measurement sensors installed above and below it in the X-Y direction, it is possible to measure displacement data on the top and bottom surfaces of the object and to set the reference plane. A shape measuring device characterized in that measurements are performed simultaneously.