JPH03115908A - Dimension measuring instrument - Google Patents

Abstract

PURPOSE:To measure an optional necessary edge-to-edge distance automatically and instantaneously by providing a clocking means which measures an elapsed time from the start of scanning as to each edge of a body to be measured, etc. CONSTITUTION:The instrument is provided with a timer part 40 which is provided for the edges of bodies 9a and 9b to be measured and clocks each elapsed time from specific time, an edge detecting circuit 38, a clocking control circuit 41 which sends a counting stop signal in edge array order to the timer part 40 every time an edge detection signal is outputted, an edge selecting circuit 42 which selects a couple of timer means corresponding to a specific edge, and an edge-to-edge distance calculating circuit 44 which calculates the edge-to- edge distance by using the counted values of the selected timer means and a function table. The elapsed time from the start of scanning is measured for each of the edges of the bodies 9a and 9b to be measured. Consequently, the optional necessary edge-to-edge distance can be measured automatically, instantaneously, and easily.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention vibrates light such as a laser beam in a certain direction, and measures the width and spacing of a plurality of objects to be measured arranged in the scanning direction of the vibration. The present invention relates to a dimension measuring device for measuring, etc.

[Prior Art] A dimension measuring device has been put into practical use as one of the measuring devices that accurately measure the dimensions of an object in a non-contact manner using, for example, a laser beam. FIG. 5 is a schematic diagram showing the general configuration of the dimension measuring device. A laser beam 2 outputted from a light source 1 is reflected by a plane mirror 3 and then reflected by each reflective surface 6 of a polygonal rotating mirror 5 which is rotationally driven by a motor 4 . Therefore,
The laser beam 2 reflected by the reflective surface 6 vibrates in a certain direction.

The vibrating laser beam 2 is irradiated onto a rod 9 to be measured via a half mirror 7 and a collimator lens 8.

The laser beam 2 that has passed through the measuring rod 9 is incident on a light receiver 11 via a condensing lens 10 .

On the other hand, the laser beam 2 reflected by the half mirror 7 is irradiated onto a reference rod 13 for calibration (scanning monitor) via a collimator lens 12. The laser beam 2 that has passed through the reference rod 13 is incident on the light receiver 15 via the condenser lens 14 .

In such a dimension measuring device, the laser beam 2 has a period T determined by the number of rotations of the rotary mirror 5 and the number of reflective surfaces 6 on the rod 9 to be measured. is scanned in a direction perpendicular to the optical axis. Therefore, the signal waveform of the light reception signal a output from the light receiver 11 has a period T in which it remains at a low (L) level for a period T during which light is blocked by the measuring rod 9. It becomes a periodic waveform of

Due to the presence of the reference rod 13, the light reception signal a2 outputted from the light receiver 15 is at L level only during the existence period of the reference rod 13, as shown in the figure. Then, the count value of the scanning period and the count value of the center position of scanning are determined from the edge count value of the received signal a2. By subtracting the count value at the center position from each edge count value of the reference rod 13 and further dividing by the count value of the scanning period, the phase occupied by each edge in the scanning period is determined. Each phase can be converted into a value corresponding to each edge position using a function table showing the change in scanning position over time.

Although the difference between the edge positions obtained in this way varies depending on the scanning width, this value is defined as the measured value M of the reference rod.

The measurement value is determined from the light reception signal a from the measuring rod 9 using the same procedure as that for the reference rod 13. is found. This measured value D0 also changes depending on the scanning width, but the measured value M mentioned above. The true measured value d of the rod 9 to be measured is calculated using the true value dS of the reference rod 13.

d=Do (ds/Mo) [Problems to be Solved by the Invention] However, even in the dimension measuring device configured as described above, there are still problems to be improved as described below.

That is, as shown in FIG. 6, a plurality of rods to be measured 9a
, 9b and the distance g (gap) between the measuring rods 9a and 9b, the L level periods TA and TB at two locations included in the light reception signal a1 and their L level are measured. It is obtained by measuring one H level period TG sandwiched between periods TA and TB.

However, according to this measurement method, as mentioned above, distance measurement uses a counter that measures the duration of the L level and a counter that measures the duration of the H level.
Among the distances between the four edge positions ``■■■■'' indicating the positions of both ends of the two rods 9a and 9b, only the three types of distances d, , g, and d2 that are adjacent to each other can be measured.

Therefore, when measuring the distance between edges ■■, the distance between edges ■■, the distance between edges ■■, etc., the distance between edges 00 is, for example, segment 1. The distance between edges ■■ is named segment 2, and the distance between edges 00 is named segment 3, and the distance measurement between edges ■■ is calculated as segment 1+2. Similarly, Etsuji ■■
The distance between them is calculated using segments 1+2+3.

Therefore, it is necessary to specify the dimensions between edges that are not originally intended to be measured, which is not intuitive, and there is a risk of forgetting to specify the segments in between. Then, there is a possibility that the forgotten measurement result will not be corrected and an erroneous measurement result will be output.

Further, in the example of segments 1 to 3 described above, it is possible to add a fixed value as an offset to the measured value and output it, but the order of the calculation is fixed for each segment.

That is, the measured value M obtained by adding an offset value of 0 to the raw measured value M1 of segment 1 is M - M, +Q, but -0 for the raw measured value M2 of the adjacent segment 2. -M2 operation was applied and this relationship was fixed.

Therefore, depending on the dimension to be measured, it is necessary to change the installation conditions so that the location of that dimension becomes the segment where the necessary calculations are performed, and it is necessary to prepare conditions that are not originally necessary for measurement.

As a result, the types of measurement as a dimension measuring device are limited,
There was a problem in that it was not able to fully meet the wide range of measurement demands of testers.

The present invention was made in view of these circumstances, and
By providing a timer that measures the elapsed time from the start of scanning for each edge of the object to be measured, any desired distance between edges can be measured automatically and immediately, meeting a wide range of measurement requirements from users. The purpose is to provide a dimension measuring device that can.

[Means for Solving the Problems] In order to solve the above problems, according to the dimension measuring device of the present invention, light that vibrates at a constant period in the arrangement direction is applied to a plurality of objects to be measured arranged in one direction. In a dimension measuring device, the distance between the edges of each measured object is measured from the position where the signal level of the received light signal changes by emitting light and receiving the light with a receiver placed behind the measured object. A plurality of time measuring means are provided corresponding to each edge of the object to be measured and count each elapsed time from a predetermined time, and each signal level generated when the light in the received light signal passes through each edge position of each object to be measured. an edge detection circuit that sequentially detects changes; a timekeeping control circuit that sequentially sends a counting stop signal to each timekeeping means in the order of edge arrangement each time an edge detection signal is output from the edge detection circuit; an edge selection circuit that selects a pair of time measurement means corresponding to the edges located at both ends of the distance between edges to be measured; and an edge selection circuit that selects each count value of the pair of time measurement means selected by this edge selection circuit, and scans the count value and each count value of the pair of time measurement means selected by this edge selection circuit. It is equipped with an edge-to-edge distance calculation circuit that converts the light positions into edge positions using a function table that associates them with each other, and calculates the distance between the corresponding edges from the difference between these edge positions.

In another invention, the means for specifying the edge-to-edge distance to be measured includes a pattern indicator lamp for displaying a light-dark pattern of the received light signal and an arbitrary edge specified by the displayed pattern. A measurement edge setting device with an edge designation key is used.

[Function] According to the dimension measuring device configured in this way, when the predetermined time comes, each time measuring means provided corresponding to each edge of each object to be measured starts counting the elapsed time all at once. do.

The signal level of the light reception signal output from the light receiver changes each time the light passes through each edge position, but each time the signal level changes, it is detected by the edge detection circuit, and the counting of the timing means of the corresponding edge is performed. Stop. Therefore, at the time when one scan of light is completed, each time measuring means stores a count value corresponding to the elapsed time from a predetermined time to each edge position. Each count value is converted to each edge position using a function table that associates the relationship between the count value and the scanning light position. Therefore, when the distance between measurement edges is specified, the distance between the corresponding edges can be easily calculated from the difference between the edge positions at both ends.

Note that the above function table is provided to correct for the fact that, for example, when a laser light source is scanned in a sine wave state, the elapsed time and the scanning light position do not have a linear relationship but become a sine wave function. There is.

Further, in another invention, the brightness and darkness pattern of the received light signal is displayed, and the distance between edges to be measured can be specified while observing the pattern.

[Example] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram showing the general configuration of a dimension measuring device according to an embodiment. A laser beam 22 output from a laser light source 21 is reflected by a plane mirror 24 attached to one free end of a tuning fork deflector 23. The drive circuit 25 operates the tuning fork deflector 23 by passing an exciting current through the electromagnetic coil 26.
, the tuning fork deflector 23 vibrates at a constant frequency (period T) determined by its shape. Therefore, the laser beam 22 reflected by the plane mirror 24 also vibrates in the scanning direction indicated by arrow B in the figure. The oscillating laser beam 22 is converted into parallel light by a collimator lens 27, and is passed through a half mirror 28 to the outer diameter d of the object to be measured as shown in FIG.
I+ d2+ and a measuring rod 9a having a gap g;
9b is irradiated. Each measuring rod 9 arranged in the scanning direction
The laser beam 22 that has passed through a and 9b is incident on a light receiver 31 via a condenser lens 30.

On the other hand, the laser beam 22 reflected by the half mirror 28 is irradiated onto the reference rod 13 having an outer diameter ds for calibration. The laser beam 22 that has passed through the reference rod 13 is incident on the light receiver 34 via the condenser lens 33 .

1. As shown in FIG. 3, the light reception signal C output from the light receiver 31 is waveform-shaped by a waveform shaping circuit 37 to an H level or an L level, and then input to an edge detection circuit 38.

The edge detection circuit 38 sequentially detects each signal level drop that occurs when the laser beam 22 in the waveform-shaped received light signal C passes each edge position of each measuring rod 9a, 9b, and detects an edge. Send signal e to the next three logic circuits. This logic circuit 39 includes a timekeeping section 40 consisting of a plurality of timekeeping means corresponding to each edge, a timekeeping control circuit 41 that controls the operation of this timekeeping section 40, and a measurement edge interval setting device 43.
Each elapsed time Ta corresponding to each edge position set in
, and an edge selection circuit 42 for selecting Tb.

A pair of elapsed times Ta and Tb output from the logic circuit 39
is each edge position calculation unit 45 of the inter-edge distance calculation circuit 44
a, 45b. Each edge position calculation unit 45a,
Since the laser beam 22 is scanned in a sinusoidal manner, the function table 45b stores two function tables in which each elapsed time (count value) is associated with the scanning light position. And each edge position detection section 45a,
45b converts each input elapsed time (count value) into each edge position using the function table with the edge of the reference rod 13 as the reference position.

In the process of conversion, the calibration value (ds/Mo
) to the actual distances Da and Db from the reference position.

The calculated distances Da and Db are determined by the switching circuit 47a.

The signal is input to the subtraction circuit 48 via 47b. Each switching circuit 47a, 47b is connected to the (+) from the measurement edge setting device 43.
) or (-) setting command. The subtraction circuit 48 calculates the difference distance (Da
-Db) or (Db-Da) as the edge-to-edge distance between the specified edges.

The light reception signal output from the light receiver 34 is waveform-shaped by four waveform shaping circuits. Then, a count start signal shown in FIG. 3 is sent to the logic circuit 339 at the timing when the signal level of the waveform-shaped received light signal changes. Therefore, this count start signal is
When scanning the reference rod 13 while vibrating in a sinusoidal manner,
The laser beam 22 is output at the timing when it crosses the reference rod 13. That is, the edge position of the reference rod 13 becomes the reference position when calculating the edge positions Da and Db of the measurement rods 9a and 9b.

The light reception signal output from the waveform shaping circuit 49 is manually input to the calibration value calculation section 46 . This calibration value calculation unit 46 calculates the calibration value (ds/Mo) for calculating the true measurement value using the method described above.
is calculated and sent to the edge-to-edge distance calculation circuit 44.

Next, details of the logic circuit 39 will be explained using FIG. 2.

The counter 52 increments the number of clock signals output from the clock signal generator 51 by =1. And the count value is the reference rod 1
When the count start signal indicating the rising edge of 3 is input, it is cleared and counting is restarted from the beginning. That is, the counter 52 counts the elapsed time from the input time of the count start signal. The elapsed time output from the counter 52 is calculated by each of the n latch circuits 5B1, 53□, 533. ..., is applied to the 53° input terminal. Each latch circuit 531, 532゜533
,..., 53fi reads the elapsed time measured by the counter 52 at the timing when each register R, -R, of the time control circuit 41 consisting of a shift register rises from the L level to the H level. . The captured elapsed times T1 to T, , are then sent to each selector circuit 42a, 42b within the edge selection circuit 42. In addition, each latch circuit 53
1,532°533. ..., 53. The elapsed times T1-T, , latched in , are cleared by the next count start signal.

As mentioned above, the timekeeping control circuit 41 is formed of a type of shift register having (n + 1) registers R8-R, and receives a count start signal and a reset terminal R.
When input to E, the bits of each register Ro to R, , are cleared to 0 (L), and the bit of the first register R8 is set to 1 (H). Then, each time the edge detection signal e is input from the edge detection circuit 38 to the clock terminal CP, the 1 (H) bit of register 5 to register R8 is sequentially transferred to each register R on the right side.
Move from 3 to R. Since the edge detection signal e is output in response to a change in the signal level of the waveform-shaped received light signal, each latch circuit 53. .

53□,...,53. , the elapsed time T1 latched to
゜T2. ..., To is the elapsed time required for the laser beam 22 to reach each edge position from the time when it passes the edge of the reference rod 13.

Therefore, the clock signal generator 51. counter 52
and each latch circuit 5 BI~53. Each elapsed time T, , T2 . . . . constitutes a plurality of timing means for timing T7.

The display panel of the measurement edge setting device 43 shows the received light signal C.
A plurality of pattern indicator lights 54 for displaying brightness/dark patterns and a plurality of edge indicator lights 55 for measuring edge positions are provided. Further, a display movement key 56a and a setting key 56b for specifying the position between measurement edges are provided. Furthermore, a code key 57 is used to specify whether to display the edge-to-edge distance calculated by the edge-to-edge distance calculation circuit 644 with a (+) sign or a (-) sign.
is provided.

Then, depending on the number of rods 9a and 9b to be measured,
The brightness and darkness pattern of the received light signal C is displayed on the pattern indicator lamp 54 using a panel switch (not shown). Next, the lighting position of the edge indicator light 55 is moved using the display movement key 56a so that the edge indicator light 55 corresponding to the edge at one end of the edge interval to be measured is lit. Thereafter, when the setting key 56b is pressed manually, the corresponding edge is input. Similarly, input the other edge of the edge interval to be measured. Each edge signal indicating each input edge is input to each selector circuit 42a, 42b. In this case, the edge located farther from the reference position of the selected edges (1) to (2) is input to the selector circuit 42b.

Each selector circuit 42a, 42b has a latch circuit 53. ~53. 7. Select the elapsed times Ta and Tb and calculate each edge position calculation unit 45.
a, 45b.

Therefore, when the (+) sign is selected with the sign setting key 57, the switching circuits 47a, 47b maintain the state shown in the figure, and the subtraction circuit 48 outputs the edge distance D-(D
a-Db) is output and when the (=) sign is selected with the sign setting key 57, the switching circuits 47a and 47b are connected inversely, so the subtraction circuit 48 outputs the edge distance D- of the (-) value.
-(Da-Db) is output.

In addition, generally, each outer diameter d, d of each measuring rod 9a, 9b
When measuring 2, it is indicated by (10), and when measuring the interval g, it is indicated by (-).

FIG. 3 is a time chart showing the operations of three logic circuits. When the count start signal S is input, the counter 52 is reset and starts counting the elapsed time again. Further, the signal level of the light reception signal C output from the light receiver 31 changes each time the laser beam 22 passes through each edge of each of the measurement rods 9a and 9b. Then, the waveform is shaped by a waveform shaping circuit 37. Each edge ■■■■ of the waveform-shaped received light signal is detected by the edge detection circuit 38, and each latch circuit 53. ．． 5
3□, 53. ．． 534 is the elapsed time T+, T2, when each edge ■■■■ is detected by the edge detection circuit 38.
Take in T3 and T4. Each captured elapsed time TH, T2
, T3, and T4 are sent to each selector circuit 42a, 42b. Then, a pair of elapsed times Ta and Tb corresponding to the specified edge are selected from the measurement edge distance setting device 43 and sent to the edge distance calculation circuit 44 . Then, the distance between the specified edges is measured.

According to the dimension measuring device configured in this way, the operator can set the edges located at both ends between the edges to be measured using the measurement edge distance setting device 43 using the display movement key 568 and the setting key 56b. , the distance between corresponding edges can be automatically measured.

That is, in the conventional device, the specified segment always had to be the distance between adjacent edges, but in this embodiment, the distance between adjacent edges is
In addition to ■〜■, ■〜■ distance, there are 9 distances between edges located far apart between ■〜■, between edges ■〜■,
Each set M(d++g) between the edges ■～■.

It becomes possible to intuitively specify and measure (d+ +g+62) and (g+d2) as they are.

In addition, in the embodiment, there are two rods 9a to be measured.

Although the case where 9b is measured has been described, it is not particularly limited to two.

FIG. 4 is a block diagram showing a timer section 60 of a dimension measuring device according to another embodiment of the present invention. Other parts are the same as in FIG.

In this embodiment, the latch circuits 53, to 5 of FIG.
3. ．． Instead of , counter 61161□+613+ ・
. . , 61o are provided, and the clock signal generator 5
A clock signal is directly input from 1. Then, when the count start signal is input, each counter 611 to 61
．． clears the elapsed time that has been counted up to now and starts counting the elapsed time again. Then, the timing control circuit 4
When the H level timing stop signal is input from 1 to 1, respectively,
Stop timing operation. Then, each red time period T, ~T, is sent to each selector circuit 42a, 42b in the edge selection circuit 42.

Also in the dimension measuring device configured in this way, since the elapsed times T and -T1 at each edge are determined independently, it is possible to measure the distance between arbitrary edges. Therefore, it is possible to obtain substantially the same effects as in the previous embodiment.

[Effect of the invention] As explained above, according to the J method measuring device of the present invention,
The elapsed time from the start of scanning is measured for each edge of the object to be measured. Therefore, any required distance between edges can be easily and automatically measured based on the time difference between each elapsed time. Therefore, it is possible to meet a wide range of measurement requirements from measurers.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the general configuration of a dimension measuring device according to an embodiment of the present invention, FIG. 2 is a block diagram showing the main parts of the device according to the embodiment, and FIG. 3 is a diagram showing the main parts of the device according to the embodiment. 1. FIG. 4 is a block diagram showing the main parts of a dimension measuring device according to another embodiment of the present invention, and FIG. 5 is a schematic diagram showing the general configuration of a conventional dimension measuring device. 6 are diagrams for explaining the measurement principle. 9a, 9b...Measurement rod, 21...Laser light source, 2
2... Laser light, 23... Tuning fork deflector, 27...
Collimator lens, 30... Condensing lens, 31.33
. . . Light receiver, 37 . . . Waveform shaping circuit, 38 . . . Edge detection circuit, 40. 69 . -Measurement edge setting device, 44...edge distance calculation circuit.

Claims (2)

[Claims] (1) Multiple objects to be measured arranged in one direction (9a, 9
For b), light (
22), the light is received by a light receiver (30) disposed behind the object to be measured, and the distance between the edges of each of the objects to be measured is measured from the position where the signal level of the received light signal changes. In the dimension measuring device, a plurality of time measuring means (51
, 52, 53_1 to 53_n, 61_1 to 61_n), and an edge detection circuit (38) that sequentially detects each signal level change that occurs when the light in the light reception signal passes through each edge position of each of the objects to be measured. , a timekeeping control circuit (41) that sequentially sends a counting stop signal to each of the timekeeping means in the order of edge arrangement each time an edge detection signal is output from the edge detection circuit, and an externally specified edge to be measured. an edge selection circuit (42) that selects a pair of timekeeping means corresponding to edges located at both ends of the distance;
Each count value of the pair of time measurement means selected by this edge selection circuit is converted into an edge position using a function table that associates the count value with the scanning light position, and the difference between the corresponding edges is determined from the difference between these edge positions. Edge-to-edge distance calculation circuit (4
4) A dimension measuring device comprising: (2) A pattern indicator (54) for displaying the light/dark pattern of the received light signal and an edge specification key (54) for specifying any edge from among the edges determined by the displayed pattern.
measuring edge-to-edge setting device (43
2. The dimension measuring device according to claim 1, wherein the distance between the edges to be measured is specified using the following formula.