JPH08178621A - Image measuring instrument - Google Patents

Abstract

PURPOSE: To provide an measuring instrument which can measure an object to be measured without moving the same, and can prevent the occurrence of an error accompanied by the movement of the object to be measured. CONSTITUTION: An image measuring instrument is provided with a stage on which an object to be measured is placed, image pickup means 31, 32 capable of picking up an image of the object to be measured with variable magnification, an monitor 60 displaying the image picked up by the pickup means 31, 32, an indicator displayed on the monitor 60 and indicating the measurement area of the object to be measured, and an operation means 50 moving the indicator on the display 60.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image measuring machine,
In particular, it is possible to perform measurement without moving the object to be measured, and to prevent an error from occurring due to the movement of the object to be measured.

[0002]

2. Description of the Related Art Conventionally, an image measuring instrument of this type has a zoom mechanism and, as shown in FIG. 13, indicates a measurement area of an object 111 to be measured in the center of a monitor screen 110, for example, a square index 112. Was being displayed. Then, as shown in FIGS. 14 to 16, the measurement points a to c were positioned within the index 112 while moving the DUT 111.

The reason why the index 112 is arranged at the center of the monitor screen 110 is that the center portion is advantageous in terms of distortion of the lens system of the image measuring machine. Further, the movement of the object to be measured 111 is not shown, but it is possible to move the object 111 in two horizontal axes.
I was using the stage.

[0004]

However, in the above-mentioned conventional image measuring machine, it is troublesome to move the object 111 to be measured while positioning the measurement points a to c within the index 112. There was a problem. That is, the object 111 to be measured is searched at a relatively low magnification, and the object 111 to be measured is moved on the object 111 while the measurement points a to c are positioned within the index 112. Then, at the time of measurement, in order to improve the measurement accuracy, the object to be measured 111 was enlarged and measured as much as possible.

However, it is difficult to find the next measurement points a to c with the object to be measured 111 enlarged. Therefore, again returning to a relatively low magnification, searching for the next measurement points a to c,
It was necessary to enlarge the DUT 111 again and repeat this. In addition, in the above-mentioned conventional image measuring machine, XY
Since the DUT 111 was moved using the stage,
There was a second problem in that the error due to the movement was included in the measured value.

Therefore, the invention according to claim 1 is made in view of the first problem of the above-mentioned conventional technique, and the purpose thereof is to move the object to be measured without moving the object to be measured. An object is to provide an image measuring device capable of measuring an object to be measured. In addition to this, the invention according to claim 1 is made in view of the second problem of the above-mentioned conventional technique, and the purpose thereof is XY.
An object of the present invention is to provide an image measuring device capable of preventing the occurrence of an error due to the movement of the object to be measured by the stage.

That is, when the object to be measured is enlarged, X
The movement error of the Y stage is also relatively increased. For this reason, the influence due to the movement error of the XY stage becomes larger than the error due to the distortion around the lens system of the image measuring instrument. Therefore, the index is not limited to the center of the screen of the monitor and can be freely moved, so that the object to be measured can be measured without moving the object to be measured by the XY stage.

The invention according to claim 2 is the above-mentioned claim 1.
In addition to the object of the invention described above, it is an object of the present invention to provide an image measuring instrument capable of measuring with a higher degree of freedom by making the size of the index variable.

[0009]

The present invention is to achieve the above-mentioned object, and the contents thereof will be described below with reference to the embodiments shown in the drawings. The invention according to claim 1 is characterized by the following five points. The first is a stage (for example, the XY stage 13) on which the object to be measured (for example, the circular pattern 20 in FIG. 4) is placed as shown in FIG. is there.

The second means is an image pickup means (30).
0) is, for example, as shown in FIG. 2, the object to be measured (for example, the circular pattern 20 in FIG. 4) can be imaged at a variable magnification. The third is a monitor (60), which displays an image picked up by the image pickup means (30), as shown in FIG. 1, for example.

The fourth is an index (70), which is displayed on the monitor (60), for example, as shown in FIG.
The measurement area of the object to be measured (for example, the circular pattern 20 in FIG. 4) is designated. The fifth is the operating means (50),
The operating means (50) is for moving the index (70) on the monitor (60) as shown in FIG. 1, for example.

The invention according to claim 2 is the above-mentioned claim 1.
In addition to the features described, the following features are provided. That is, in the invention according to claim 2, the size of the index (70) on the monitor (60) is set to the operating means as shown in FIG. 1, for example.
It can be changed by (50).

[0013]

[Operation] Therefore, according to the invention of claim 1,
It has the following effects. That is, on the monitor (60),
As shown in FIG. 4, the DUT (for example, circular pattern 20)
Is displayed. At this time, the DUT (for example, circular pattern
The variable magnification of the image pickup means (30) is set so that the measurement point of (20) is displayed on the monitor (60).

Next, the index (70) is operated while operating the operating means (50) in accordance with the measurement position of the object to be measured (for example, the circular pattern 20 in FIG. 4) displayed on the monitor (60). Move to measure. If there are multiple measurement points,
While repeatedly operating the operating means (50), the index (70) is adjusted to the measurement location and the measurement is repeated.

According to the invention described in claim 2, in addition to the operation described in claim 1, the following operation is achieved. That is, the size of the index (70) on the monitor (60) can be changed by operating the operating means (50) in addition to moving the index (70).

[0016]

1 to 4 show a first embodiment of the present invention. FIG. 1 is a block diagram, FIG. 2 is a schematic configuration diagram of an image processing measuring machine, and FIG. 3 shows an object to be measured. FIG. 4 is a plan view of a monitor screen, and FIG. 4 is a plan view of a monitor screen in which the DUT of FIG. 3 is enlarged. In FIG. 2, 10 indicates an image measuring device,
This image measuring device 10 measures an object to be measured having a plurality of circular patterns 20 as shown in FIG. 3, and measures the center point or diameter of one circular pattern 20 or the distance between two adjacent circular patterns 20. It is used to measure etc.

The image measuring machine 10 is roughly provided with a base 11 and a column 12 extending upward from the base 11 in an L-shape, as shown in FIG. Then, on the upper surface of the base 11, as shown in FIG.
A Y stage 13 is provided. An object to be measured is placed on the upper surface of the XY stage 13, and is illuminated from below by a transmitted illumination 14 embedded in the base 11.

As shown in FIG. 2, above the XY stage 13, there is provided an image pickup means 30 capable of picking up a circular pattern 20 of the object to be measured placed on the XY stage 13 at a variable magnification. ing. As shown in FIG. 2, the image pickup means 30 includes a zoom mechanism-equipped microscope section 31 for forming a variable-magnification image of the transmitted light of the circular pattern 20 of the object to be measured which is illuminated by the transmitted illumination 14 from below. A CCD camera 32 for picking up an image formed by the microscope section 31 is provided. The image pickup means 30 is supported by the column 12 via the vertical movement part 25 so as to be vertically movable.

The CCD camera 32 is not a transmitted light,
You may make it image the reflected light of the circular pattern 20 of a to-be-measured object. The lower end of the microscope section 31 has an objective lens
33 and TTL lighting 34 are attached. The microscope section
Although not shown, the zoom mechanism 31 includes a drive mechanism for a zoom drive lens and drive lens position detection means. Then, the zoom magnification is determined steplessly by the drive lens position detecting means.

Next, the image measurement processing unit 40 of the image measuring machine 10 having the above-mentioned configuration will be described with reference to FIG.
The image measurement processing unit 40 is mainly composed of a CPU, and at the input stage thereof, as shown in FIG.
For example, an operating means 50 such as a mouse is connected. Also,
A monitor 60 that displays an image captured by the CCD camera 32 and a microscope unit 31 with a zoom mechanism are connected to the output stage.

As shown in FIG. 1, the image measurement processing section 40 is provided with image processing means 41 for displaying the image captured by the CCD camera 32 on the monitor 60. As shown in FIG. 1, the operating means 50 changes the size of the index 70 on the monitor screen 61 and the index moving means 42 for moving the index 70 shown in FIG. 4 on the monitor screen 61. The index area changing means 43 is connected.

As shown in FIG. 4, the index 70 indicates the measurement area of the circular pattern 20 of the object to be measured on the monitor screen 61, and is formed in a box shape, for example. As shown in FIG. 4, the index 70 is displayed on the monitor screen 61 by the image processing means 41 shown in FIG. Then, when the operating means 50 is operated, the index moving means 42 moves on the monitor screen 61.

When the operating means 50 shown in FIG. 1 is operated, the index 70 is displayed on the monitor screen by the index area changing means 43.
The size on 61 changes. Then, when the user specifies the measurement point of the circular pattern 20 while moving the index 70 or changing the size thereof by the operation means 50 shown in FIG. 1, measurement by the image measurement means 44 is started. The measurement result is displayed on the monitor 60, for example.

Further, as shown in FIG. 1, an automatic magnification calibration means 45 using the magnification calibration plate 10 shown in FIG. 8 is connected to the operating means 50. The automatic magnification calibration means 45
As shown in FIG. 1, while changing the magnification of the microscope unit 31 with a zoom mechanism in, for example, five steps, the correction count calculation storage means 46 obtains and stores the correction count for each magnification. Then, the measurement value of the image measuring means 44 is corrected using the correction count for each magnification.

Next, the procedure for measuring the circular pattern 20 of the object to be measured will be described with reference to FIGS. First, as shown in FIG. 3, the microscope unit 31 with a zoom mechanism is set to a low magnification, and the circular pattern 20 to be measured is searched for. Then, when the circular pattern 20 to be measured is determined, the circular pattern 20 is positioned by the XY stage 13 at the center of the monitor screen 61.

Next, the microscope unit 31 with a zoom mechanism is switched to a high magnification, and the circular pattern 20 is displayed in full on the monitor screen 61 as shown in FIG. The reason for switching to a high magnification is to improve the measurement accuracy. Then, the user moves the index 70 or changes the size of the index 70 by the operating means 50 shown in FIG.
Specify 20 measurement points. This operation is repeated according to the shape of the pattern of the measured object. For example, circular pattern 20
In this case, the pattern can be specified by designating three points on the outer circumference, and for example, the center and diameter of the circle can be measured.

FIG. 5 shows a second embodiment of the present invention, which is a plan view of a monitor screen showing an index. The feature of the second embodiment lies in the shape of the index 71, which is shown in FIG.
The index 70 shown in FIG. 2 is a box type, while the index 71 of the second embodiment is a line type. Further, only one index 71 of the second embodiment is displayed on the monitor screen 61, and this index 71 is circular pattern as shown in FIG.
By performing the operation three times in total while moving radially along the outer circumference of 20, the center and diameter of the circle can be measured, for example.

Next, a method for detecting the outer peripheral edge of the circular pattern 20 will be briefly described. First, as shown in FIG. 5, the line type index 71 is grasped and moved / resized by operating means 50 (FIG. 1) such as a mouse, and is aligned with the vicinity of the outer edge of the circular pattern 20 to be detected. Next, when the right button of the mouse (not shown) is pressed, for example, the position and length of the index 71 with respect to the image processing means 41 shown in FIG.
An instruction is issued to inform the angle and detect an edge from the specified range.

In response to this, the image processing means 41 scans the image within the designated range, and takes in the gray scale (representing the level of light and dark and expressed by 256 gradations) of each pixel. Then, with respect to all the captured gray scales, the adjacent gray scales are checked and the change amount is calculated. A location having a large absolute value is determined as an edge by using the amount of change as contrast. Then, the position of the edge within the index 71 is returned.

Therefore, for example, the image measuring means 46 shown in FIG.
Is the stage coordinates, the position of the index 71 on the monitor 60 and the index 71
The position of the edge on the monitor 60 is specified by adding the position of the edge on the inside. The box-type index 70 of the first embodiment described above detects edges in the same manner as the line-type index 71 described above, but the inside of the box is divided by a specified number, and only the specified number of edges are divided. Can be detected at once.

FIG. 6 shows a third embodiment of the present invention, which is a plan view of a monitor screen showing an index. The feature of the third embodiment lies in the shape of the pattern of the object to be measured, and the pattern 20 of the third embodiment is circular while the pattern 20 of the first embodiment shown in FIG. 4 is circular. It is a square.

In the third embodiment, one box-shaped index 70 is used, and as shown in FIG. 6, the index 70 is moved to the four sides of the rectangular pattern 21 and operated four times in total. Thus, for example, the center of the rectangle and the lengths of the vertical and horizontal sides can be measured. FIG. 7 shows a fourth embodiment of the present invention, which is a plan view of a monitor screen showing indexes.

The feature of the fourth embodiment lies in the shape of the pattern of the object to be measured, and the pattern 20 of the first embodiment shown in FIG. 4 is circular, while the pattern of the third embodiment is different. Pattern 22
Is in the shape of a strip. In the fourth embodiment, one box-shaped index 70 is used, and the index 70 is moved to the upper and lower edges of the strip pattern 22 as shown in FIG.
By performing the operation twice in total, the vertical width of the strip-shaped pattern 22 can be measured, for example.

8 to 11 show a fifth embodiment of the present invention. FIG. 8 is a plan view of a magnification calibration plate, FIG. 9 is a plan view of a monitor screen displaying the magnification calibration plate, and FIG.
0 is an explanatory view of the magnification calibration using the magnification calibration plate, (a) is a partial plan view of the magnification calibration plate, (b) is a waveform diagram of the detected light amount level at an appropriate light amount, and (c) is Waveform diagram of the detected light intensity level when the light intensity is reduced.
0 is an explanatory diagram used for comparison with FIG. 0, in which (a) is a plan view showing a pattern example of a conventional magnification calibration plate, (b) is a waveform diagram of a detected light amount level with an appropriate light amount, (C) shows a waveform diagram of the detected light amount level when the light amount decreases, and (d) shows a waveform diagram of the detected light amount level when the light amount increases.

First, the magnification calibration plate 80 of the fifth embodiment
Prior to the description of FIG. 11, a conventional magnification calibration plate will be briefly described with reference to FIG. When the transmitted illumination is illuminated from the back side of the square pattern surface of FIG. 11 (a) and the surface side is detected, when the amount of the transmitted illumination is appropriate, a waveform of the detected light amount as shown in FIG. can get.

In order to obtain a measured value from the waveform of the detected light amount, a threshold level SL that passes near the center of the peak value of the detected light amount waveform is preset as shown by the broken line in FIG. 11 (b). The two intersections of the threshold value SL and the detected light intensity waveform are set as the bright and dark boundary positions, and the interval A1 between the boundary positions is obtained. The interval A1 between the boundary positions is equal to the reference length W of the square pattern shown in FIG. 11A when the amount of transmitted illumination light is appropriate.

On the other hand, for example, when the amount of transmitted illumination light decreases, the peak value of the detected light amount waveform decreases,
Measurement is possible if the threshold level SL is not lowered. However, because the amount of transmitted illumination light decreases, the amount of light diffraction at the light-dark boundary of the pattern decreases, and so on. As shown in FIG. 11 (b), the positions often extend outward by Δd.

Therefore, the interval A2 between the boundary positions is as shown in FIG.
It becomes shorter than the reference length W of the square pattern shown in (a). Therefore, if there is an error of Δd on one side, a doubled error of Δd will be added to the obtained measured value. On the contrary, when the amount of transmitted illumination light increases, generally, the light and dark boundary positions on both sides of the pattern are as shown in FIG.
As shown in (4), it is often narrowed to the inside by the same degree. Therefore, the boundary position interval A3 becomes longer than the reference length W of the square pattern shown in FIG.

On the other hand, the magnification calibration plate 80 of the fifth embodiment has reference lengths Ax to Ex, Ay as shown in FIG.
At both ends of ~ Ey, the directions of "bright" and "dark" are matched. That is, the magnification calibration plate 80,
As shown in FIG. 8, the reference length A measured during magnification calibration
A pattern having x to Ex and Ay to Ey is formed.

The reference lengths Ax to Ex and Ay to Ey are, as shown in FIG. 8, provided with five kinds of reference dimensions coaxially for each of the vertical and horizontal axes, and are the same as those of the first embodiment shown in FIG. It corresponds to the five-step magnification correction of the microscope unit 31 with a zoom mechanism. As shown in FIG. 8, the pattern is composed of a bright portion 90 and a dark portion 100. That is, the pattern is formed by depositing a vapor deposition material such as chromium on a transparent substrate such as glass. In the figure, the hatched portion is the vapor-deposited portion, and when the vapor-deposited portion is observed from the CCD camera 32 side through the transmissive illumination 14 of the first embodiment shown in FIG.
It becomes “dark” and constitutes the dark part 100. On the other hand, the non-deposited portion becomes “bright” when viewed from the CCD camera 32 side through the transmissive illumination 14, and constitutes the bright portion 90.

As shown in FIG. 8, the bright portion 90 and the dark portion 100 are formed by arranging a plurality of squares having different sizes, which are squares in this embodiment, concentrically. The light part 90 and the dark part 100
Is the diagonal line a-b of the square, and "bright" and "dark" are reversed from each other. Therefore, the bright part 90 is shown in FIG.
As shown in, the first to fifth bright portions 91 to 95 are configured. The dark portion 100 is composed of first to sixth dark portions 101 to 106.

Next, magnification calibration using the magnification calibration plate 80 having the above configuration will be described with reference to FIGS. First, the user installs the magnification calibration plate 80,
It is mounted on the XY stage 11 of the image processing measuring machine 10 of the first embodiment shown in FIG. Then, the microscope unit 31 with a zoom mechanism is set to a relatively low magnification, and the transmitted light of the magnification calibration plate 80 illuminated from below by the transmitted illumination 14 is transmitted to the CCD camera 32.
The center of the magnification calibration plate 80 is aligned while watching the image displayed on the monitor 30 through. The center of the magnification calibration plate 80, as shown in FIG.
It is the midpoint of the diagonal line of the boundary with the dark part 101.

After that, when the automatic magnification calibration is instructed by the operating means 50 shown in FIG. 1, four box-shaped indicators 70a to 70c are displayed on the monitor screen 61 as shown in FIG. Next, the magnification of the microscope unit 31 with the zoom mechanism is increased by the automatic magnification calibration means 45 shown in FIG. 1, and in this embodiment, the first bright portion 91 and the first dark portion 91 fill the screen of the monitor at the maximum magnification. 101 and are displayed. Here, the magnification is calibrated, then the magnification is lowered, and the magnification is similarly calibrated at the position where the second bright portion 92 and the second dark portion 102 are fully displayed on the monitor screen 61. At this time, since the bright part 90 and the dark part 100 are concentrically arranged as shown in FIG. 8, it is not necessary to move the magnification calibration plate 80. In this way, the magnification is sequentially calibrated at each magnification, and a total of five magnification calibrations are automatically performed.

Also, since the magnification has been changed, the bright part 90
When the boundary between the dark part 100 and the dark part 100 is out of the box-shaped indexes 70a to 70c, the automatic magnification calibration means 45 shown in FIG. There is a function of searching and moving the indicators 70a to 70c. For this reason, the user attaches the magnification calibration plate 80 to the image processing measuring machine 10.
It is only necessary to place it on the XY stage 11 and instruct the automatic magnification calibration with the operating means 50.

Next, as shown in FIG.
An example will be described in which the bright portion 93 and the third dark portion 103 are measured along the dashed-dotted line in FIG. Two intersections a and b with the alternate long and short dash line in FIG. 10A are located at both ends of the reference length Ax.
The intersection a corresponds to the boundary between the second bright portion 92 and the first dark portion 101, and when viewed from the left side in the figure, the change in the light and dark changes from “bright” to “dark”. . Further, the intersection point b corresponds to the boundary between the first bright portion 91 and the second dark portion 102, and the change in the brightness is “bright” as in the intersection point a.
Has changed from "dark" to "dark".

Similarly, the two intersections c and d with the alternate long and short dash line in FIG. 10A are located at both ends of the reference length Bx. Then, the intersection point c hits the boundary between the third dark portion 103 and the second bright portion 92, and when viewed from the left side in the figure, the change in the light and dark changes from “dark” to “bright”. . Further, the intersection point d corresponds to the boundary between the second dark portion 102 and the third bright portion 93, and the change in the lightness and darkness changes from “dark” to “bright” like the intersection point c.

When the light quantity of the transmissive illumination 14 is proper, the detected light quantity level has a waveform as shown in FIG. 10 (b). Here, the broken line in the figure indicates the threshold level SL, and the threshold level SL and the detected light intensity waveform 2
The distance between the intersections is defined as the measured value. Usually, the threshold level SL is often set near the middle of the peak value of the detected light amount at the proper light amount.

As described above, since the light and dark directions of the boundary portions at both ends of the reference length Ax are the same, in the waveform of the detected light amount, the figure corresponding to both ends of the reference length Ax in FIG. The intersections EG1 and EG2 in (b) are both located in the middle of the downward slope from the H level (bright) to the L level (dark). In this state, if the light quantity of the transmitted illumination 14 decreases, the waveform of the detected light quantity changes as shown in FIG.
When the amount of light decreases, the first and second dark portions 101, 10 that block the light
Since both sides of 2 spread outward, the peaks of the corrugation become narrower, while the bottom becomes wider conversely. As a result, the intersections EG1 and EG2 at the proper light amount move to the left side in FIG. 10 by the same amount, and the positions of the intersections EG5 and EG6 are determined. However, since the moving direction and the moving amount are the same, the distance A between the intersection points EG1 and EG2 is
1 and the interval A2 between the intersections EG5 and EG6 does not change before and after the decrease in light amount. That is, variations in the measured value due to changes in the light amount cancel each other on both sides of the reference dimension, and a measured value that is not affected by the variation in the light amount is obtained.

The same applies to both sides of the reference dimension Bx, but in this case, the intersection points EG3 and EG4 at the proper light amount are shown in FIG.
As shown in (b) and (c), since both are located in the middle of the climbing slope from the L level (bright) to the H level (dark),
It is different from the above case that both the lights move to the right side of the figure after the light amount is reduced. Although not shown and described, the remaining horizontal reference lengths Cx to Ex and the vertical reference lengths Ay to Ey
Can be measured by the same principle without being affected by the fluctuation of the light amount.

FIG. 12 shows a sixth embodiment of the present invention, which is a plan view of the magnification calibration plate. The feature of the sixth embodiment is that the bright and dark portions 90 and 100 of the fifth embodiment described above with reference to FIG. 8 are formed in concentric circles, whereas the bright and dark portions 90, 100 are formed in concentric circles. . And
The diameter of each concentric circle is specified as the reference length.

[0051]

Since the present invention is constituted as described above, it has the following effects. Claim 1
According to the described invention, it is possible to provide an image measuring instrument capable of measuring an object to be measured without moving the object to be measured.

In addition to this, according to the invention described in claim 1, it is possible to prevent the occurrence of an error due to the movement of the object to be measured. According to the invention described in claim 2, in addition to the object of the invention described in claim 1, the following effects are exhibited.
That is, according to the second aspect of the present invention, by making the size of the index variable, it is possible to provide an image measuring instrument capable of measuring with a higher degree of freedom.

[Brief description of drawings]

FIG. 1 is a block diagram.

FIG. 2 is a schematic configuration diagram of an image processing measuring machine.

FIG. 3 is a plan view of a monitor screen displaying an object to be measured.

FIG. 4 is a plan view of a monitor screen in which the DUT of FIG. 3 is enlarged.

FIG. 5 shows a second embodiment of the present invention, which is a plan view of a monitor screen showing an index.

FIG. 6 shows a third embodiment of the present invention, which is a plan view of a monitor screen showing an index.

FIG. 7 shows a fourth embodiment of the present invention, which is a plan view of a monitor screen showing an index.

FIG. 8 shows a fifth embodiment of the present invention, which is a plan view of a magnification calibration plate.

9 is a plan view of a monitor screen showing the magnification calibration plate in FIG. 8. FIG.

10A and 10B are explanatory diagrams of magnification calibration using the magnification calibration plate of FIG. 8, FIG. 10A is a partial plan view of the magnification calibration plate, and FIG. 10B is a waveform diagram of a detected light intensity level at an appropriate light intensity. ,
FIG. 7C is a waveform diagram of the detected light amount level when the light amount is reduced.

11A and 11B are explanatory views used for comparison with FIG. 10, in which FIG. 11A is a plan view showing an example of a pattern of a conventional magnification calibration plate, and FIG. 11B is a diagram showing a detected light amount level at an appropriate light amount. A waveform diagram, FIG. 7C is a waveform diagram of the detected light amount level when the light amount is decreased, and FIG. 7D is a waveform diagram of the detected light amount level when the light amount is increased.

FIG. 12 shows a sixth embodiment of the present invention, which is a plan view of a magnification calibration plate.

FIG. 13 shows a conventional example, which is a plan view of a monitor screen showing an index.

FIG. 14 is a plan view of a monitor screen in which the measurement point a of FIG. 13 is positioned in the index.

FIG. 15 is a plan view of a monitor screen in which the measurement point b of FIG. 13 is positioned within the index.

16 is a plan view of a monitor screen in which the measurement point c of FIG. 13 is positioned in the index.

[Explanation of symbols]

10 Image measuring machine 11 Base 12 Support 13 XY stage 14 Transmitted illumination 15 Vertical moving part 20 Circular pattern of the object to be measured 21 Square pattern of the object to be measured 22 Strip pattern of the object to be measured 30 Imaging means 31 Microscope unit with zoom mechanism 32 CCD Camera 33 Objective lens 34 TTL illumination 40 Image measurement processing unit 41 Image processing means 42 Index moving means 43 Index area varying means 44 Image measuring means 45 Self-magnification calibration means 46 Corrected count calculation storage means 50 Operation means 60 Monitor 61 Monitor screen 70 Box Type index 71 Line type index 80 Magnification calibration plate 90 to 95 Bright section 100 to 106 Dark section Ax to Ex, Ay to Ey
Reference length 110 Monitor screen 111 Object to be measured 112 Index a, b, c Measurement location

Claims (2)

[Claims] 1. A stage on which an object to be measured is placed, an imaging unit capable of imaging the object to be measured at a variable magnification, a monitor for displaying an image imaged by the imaging unit, and a display on the monitor. An image measuring instrument, comprising: an index indicating a measurement area of the object to be measured; and an operating unit that moves the index on the monitor. 2. The size of the index on the monitor is
The image measuring instrument according to claim 1, wherein the image measuring instrument is variable by the operating means.