JPS63250552A - Optical flaw displacement measuring instrument - Google Patents

Abstract

PURPOSE:To provide both functions for size measurement and flaw inspection by connecting both output terminals of a position detecting element to an arithmetic circuit and connecting the output terminals of the divider and adder of this circuit to a display through a data processing circuit. CONSTITUTION:A light source 3 in a measuring instrument emits a light beam to a body 2 to be measured and this light beam is reflected by a position to be measured and incident on a position detecting element 4. This element 4 sends out output signals of the same level when the light is incident on the incidence surface in the center or different output signals when the incident light deviates to one side. Both output signals are A/D-converted 7 and supplied to a subtracter 8 and the adder 9 to generate a difference signal and a sum signal, which are supplied to the divider 10 to generate a quotient signal. Data processors 11 and 12 combines the sum signal supplied from the adder 9, the quotient signal supplied from the divider 10, and raster position information generated by an instantaneous position signal generator to generate a television system image signal. Those distance image signals and flaw image signal are displayed by the distance output device 14 and flaw output device 15 of the display 13.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an optical flaw displacement measuring device for inspecting the finished state of an object to be measured. Inspection of the finished state here refers to the dimensional accuracy of the surface of the object to be measured, such as the unevenness and center runout of the surface of the rotating shaft, and the unevenness and thickness of the surface of the plate, that is, the difference between the object to be measured and the measuring element. It represents distance inspection and inspection for flaws on the surface of the object to be measured.

Conventional technology The distance between an object to be measured and a measurement element is conventionally measured by a position detection element. In this case, the position detection element has two output terminals, and depending on the position where the light beam emitted from the light source and reflected by the object to be measured is incident on the position detection element, different outputs are output from these two output terminals. Occur. The light source and the position detection element are placed a predetermined distance apart, and the light source emits a light beam in the direction in which the reflected light reaches the center of the position detection element when the wave meter object is at a reference distance. Send out. Therefore, when the distance to the object to be measured changes, the reflected light beam deviates from the center of the detection element,
As a result, the outputs of the two output terminals change. By appropriately processing these outputs using data processing technology, the distance between the object to be measured and the measuring element can be detected.

On the other hand, scratches on the object to be measured can be detected by shining light onto the object and scanning the reflected light with a photoelectric element.

Problems to be Solved by the Invention For example, after polishing, it is necessary to inspect the dimensions and flaws. If these two tests are to be performed automatically, two devices each having independent functions are required. Each device requires a certain amount of space, each is fairly expensive, and each requires a certain amount of time to measure.

An object of the present invention is to provide a measuring device that has two functions: measuring λI of dimensions and inspecting flaws, and can perform these functions simultaneously or selectively.

Means to solve problems The invention achieves this objective as follows.

That is, the two output terminals of the position detection element that scans the object to be measured are connected to an arithmetic circuit, and this arithmetic circuit has two output terminals.
It consists of an adder that forms the sum of the outputs arising from the two output terminals, a subtracter that forms the difference, and a divider that divides this difference by the sum to form the quotient, the output terminals of the divider and the output terminal of the adder being It is connected to the wound output device via a data processing circuit.

According to another configuration of the present invention, the output terminal of the divider and the output terminal of the adder of the arithmetic circuit are connected to the distance output device via the data processing circuit.

Furthermore, according to another configuration of the present invention, the output terminal of the divider of the arithmetic circuit is connected to the scratch output device via the data processing circuit.

Function As stated at the beginning, flaws on the surface of the object to be measured can be detected by measuring the amount of light reflected from the surface of the object to be measured. That is, the two outputs of the position detection element are I1. and I2, Il+I2 represents the amount of reflected light, and a decrease in reflected light (2) indicates the presence of a scratch. On the other hand, the quotient obtained by dividing the difference between the two outputs of the position detection elements by the sum, that is, (II-I2>/(T1+I2)) represents the distance between the object to be measured and the measuring device.

In addition, the present invention focuses on the following points. That is, in the case of an object to be measured whose reflectance changes significantly, the amount of reflected light 11+I2 is constantly monitored even during distance measurement to prevent misidentification of distance data. Furthermore, since the light amount data represents the presence of the object to be measured, it can be used for starting and stopping the measuring device. Moreover, since fine fluctuations in distance data represent scratches on the surface, this distance data can be used alone or in combination with light amount data to determine scratches.

The above performance T1. The operation can be performed using a microprocessor after converting the output of the position sensing element into a digital value via an A/D converter. However, the output of the position detection element may be supplied as an analog value to the operational amplifier to perform analog calculation.

The distance inspection data (consisting of distance data and light amount data) and flaw inspection data (distance M data alone or consisting of distance data and light amount data) obtained as a result of the calculation are subjected to appropriate data processing, for example, using cathode rays. DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the invention which can be displayed on a tube display or printed out from a printer will now be described with reference to the drawings.

Figure 1 shows a first embodiment of a measuring device according to the invention in a schematic block diagram. A light source provided in the measuring device 1, here a laser diode 3, emits a light beam to the object to be measured 2 through a lens. This light beam is reflected at the measurement position of the object to be measured 2 and passes through another lens and enters the position detection element 4. When the incident light enters the center of the entrance surface of the zero position detection element 4, two output terminals 5 and 6
produces output signals 1 and 12 of the same magnitude.

When the incident light shifts in one direction on the plane, I1 becomes I2
If it becomes larger and shifts in the other direction, I2 becomes larger than 11. A predetermined relationship holds between the amount of deviation of the incident light and the amount of change in the magnitude of the output signal.

The output signals 11 and 12 are fed to an A/D converter 7, where they are respectively converted into digital signals. These digital signals are subsequently fed to a subtracter 8 and an adder 9, where they are each converted into a difference signal. 11-12 and a sum signal 11+12 are formed. The difference signal and the sum signal are supplied to a divider 10, where a quotient signal (11-12)/(11+I2) is formed.

If the object to be measured 2 is, for example, a rotating shaft, this rotating shaft is
During measurement, it is rotated at a predetermined speed and moved in the axial direction at a predetermined speed. An instantaneous position signal generator (not shown) is connected to the object to be measured. Thereby, the wave meter object 2 is scanned in a raster manner, and the instantaneous position signal generator generates raster position information.

In the embodiment of FIG.
2 is the sum signal supplied from the adder 9 and the divider l
The quotient signal supplied from O and the rask position information are combined to form a television system image signal. These distance image signals and false image signals are visually displayed by the distance output device 14 and flaw output device 15 of the display 13.

Here, distance determination and scratch determination are performed based on both light amount data and distance data. In this case, the distance determination is
This is mainly done from the value of the quotient (11-12)/(11+12), but at the same time the sum 11+I2 is monitored, and if this sum changes significantly, appropriate corrections are made. - Old scratches can be determined independently from the quotient value and the sum value, but if either one is determined to be a scratch, a scratch output will be output, or if both are determined to be a scratch, a scratch output will be output. You can choose whether to issue it or not depending on your needs.

FIG. 2 shows a second embodiment of the invention, in which distance determination is performed in the same way as in the first embodiment, but flaw determination is performed only from the quotient value. Although the value of the case quotient can be used as is for determining flaws, it is advantageous to use the following method to reliably detect small flaws. That is, a predetermined number of scan data before the position currently being scanned is added, and a change in the added data is observed to determine a flaw.

In this way, changes due to scratches are always present in the summed data, but changes due to random surface changes are partially canceled out, and as a result, changes due to scratches are emphasized.

Effects of the Invention According to the measuring device according to the present invention, the photoelectric element used as a sensor and its accompanying peripheral elements are half the amount of conventional ones, so it is economical and the space required for the device is significantly reduced. Furthermore, dimension measurement and flaw inspection are
Since the measurements are performed simultaneously in one procedure, the measurement time is also significantly shortened.

In addition, damage determination and distance measurement can be performed using both distance data and light amount data, respectively.
The results are reliable, and accurate judgments can be made even on objects with poor surface conditions (those with uneven color, etc.).

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a first embodiment of a measuring device according to the present invention, and FIG. 2 is a block diagram showing a second embodiment. 1-Measuring device, 2-Object to be measured, 3-Light source, 4-Position detecting element, 7-A/D converter, 8-Subtractor, 9-Adder,
10-Divider, 11.12-Data processing circuit, 13-
Display, 14-distance output device, 15-flaw output device

Claims (3)

[Claims] (1) The two output terminals of the position detection element are connected to an arithmetic circuit, which includes an adder that forms the sum of the outputs generated from the two output terminals, a subtracter that forms the difference, and a subtracter that forms the difference. An optical flaw displacement device comprising a divider that divides by a sum to form a quotient, and an output terminal of the divider and an output terminal of the adder are connected to a flaw output device via a data processing circuit. Measuring device. (2) The two output terminals of the position sensing element are connected to an arithmetic circuit, which includes an adder that forms the sum of the outputs generated from the two output terminals, a subtracter that forms the difference, and a subtracter that forms the difference. Optical scratch displacement comprising a divider that divides by a sum to form a quotient, and an output terminal of the divider and an output terminal of the adder are connected to a distance output device via a data processing circuit. Measuring device. (3) The two output terminals of the position detection element are connected to an arithmetic circuit, which includes an adder that forms the sum of the outputs generated from the two output terminals, a subtracter that forms the difference, and a subtracter that forms the difference. An optical flaw displacement measuring device comprising a divider that divides by a sum to form a quotient, and an output terminal of the divider is connected to a flaw output device via a data processing circuit.