JPH0436603A - Optical measuring instrument - Google Patents

Abstract

PURPOSE:To make the instrument inexpensive and small in size and to smoothly attach/detach an object to be measured by outputting an edge signal when the output of a displacement detecting circuit reaches a reference value in a condition that an area signal is outputted. CONSTITUTION:Light irradiating the object is image-formed on a sensor 14 where either of an inside photodetector 21 and an outside photodetector 22 is constituted of at least >=4 equally divided light receiving elements 211 - 214 which are divided equally in the circumferential direction. Then a displacement detecting circuit 31 outputs a signal corresponding to the difference between the outputs of the element 21 and 22 of the sensor 14. A focus position detector 36 stops the relative movement between the object and an optical system when the output of the circuit 31 reaches the reference value. Further, an area signal generating circuit 41 outputs the area signal when the output difference between the outputs of two divided photodetectors which face each other in a diameter direction among the elements 211 - 214 of the sensor 14 exceeds a specific value. Then when the output of the circuit 31 reaches the reference value, the edge signal is outputted in the condition that the circuit 41 outputs the area signal.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical measuring device that measures the dimensions of an object to be measured from an image formed by an optical system. Specifically, the light irradiated onto the object to be measured is received by a sensor consisting of a light-receiving element, converted into an electrical signal, and based on this signal,
The present invention relates to an optical measuring device that automatically adjusts the focus and also measures the dimensions, position, shape, etc. of an object to be measured.

[Background technology]

Optical devices such as tool microscopes and projectors are used as devices that illuminate the object to be measured with light, form an image of the object based on the light, and measure the dimensions of the object from that image. Measuring device or known.

In this type of optical measuring device, such as a projector, it is necessary to measure the dimensions of the object while positioning the edge of the image formed on the screen at the hairline.

However, in this case, the focus of the images must first be matched, and the edges of the images must also be precisely matched with the hair lines, making the measurement work complicated and inefficient. Furthermore, individual differences tend to occur among the measurers when it comes to matching the edges of the image with the hairline.

Therefore, in order to solve these problems, conventional projectors are equipped with an autofocus mechanism and an edge detection mechanism that automatically detects the edges of the image when moving relative to the object to be measured. Something is being developed.

Here, as the autofocus mechanism, a triangular distance measurement type autofocus mechanism in which a pair of distance measurement objective lenses are arranged on both sides of a projection lens is generally used. The edge detection mechanism uses a photoelectric conversion element, and when the photoelectric conversion element and the object to be measured are moved relative to each other, the output from the photoelectric conversion element is determined based on the bright and dark areas of the image. A commonly used structure is to extract a signal and detect the edge of the object to be measured from this signal.

Therefore, the autofocus mechanism automatically adjusts the focus of the image, and when the photoelectric conversion element and the object to be measured are moved relative to each other, the edges of the image are automatically detected, making measurement work more efficient. This can be done objectively and without any individual differences.

[Problem to be solved by the invention]

However, in the conventional type, the autofocus mechanism and the edge detection mechanism are configured separately, and therefore, there are the following drawbacks.

■Since the autofocus mechanism and edge detection mechanism must be constructed separately, the structure becomes complicated and a large number of parts are required.

■This not only leads to increased costs, but also
This leads to an increase in the size of the device. Furthermore, it takes time to assemble and adjust, and this leads to a lack of reliability as a device.

■In particular, when an autofocus mechanism is installed, a pair of distance-measuring objective lenses must be placed on both sides of the projection lens; in other words, a pair of distance-measuring objective lenses must be placed on both sides above the object to be measured. Because I have to
Not only is the field of view limited, but it is also likely to cause trouble in attaching and detaching the object to be measured.

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical measuring device that solves all of these conventional problems, can be made inexpensive and compact, and does not cause any trouble in the operation of attaching and detaching objects to be measured. It is in.

[Means to solve the problem]

Therefore, the present invention attempts to achieve the above object by configuring an autofocus mechanism using a sensor that constitutes an edge detection mechanism.

Specifically, it has an optical system that irradiates the measurement target with light and forms an image of the measurement target based on the light, and the image that is formed while the optical system and the measurement target are moved relative to each other. An optical measuring device for measuring the dimensions of an object to be measured, including an inner light-receiving element with a circular outer periphery and an annular outer light-receiving element arranged concentrically with the inner light-receiving element,
and a sensor in which either one of the inner light receiving element and the outer light receiving element is divided into at least four equally divided light receiving elements in the circumferential direction, and the sensor is configured with light irradiated onto the measurement object. an imaging lens that forms an image of the object to be measured; a displacement detection circuit that outputs a signal corresponding to the difference between the output of the inner light receiving element and the output of the outer light receiving element of the sensor; a focal position adjustment device that relatively moves the object and the optical system in the direction of the focal depth of the optical system and stops the relative movement when an output from a displacement detection circuit reaches a reference value; and a divided light receiving element of the sensor. A region signal generation circuit that outputs a region signal when the difference in the output of two diametrically opposed divided light receiving elements exceeds a predetermined value, and a region signal being output from this region signal generation circuit. The present invention is characterized by comprising an edge signal generation circuit that outputs an edge signal when the output from the displacement detection circuit reaches a reference 1 on the condition that

In addition, it has an optical system that irradiates the measurement target with light and forms an image of the measurement target based on the light, and while moving the optical system and the measurement target relatively, the formed image is used to form an image of the measurement target. In optical measuring devices that measure the dimensions of objects,
It has an inner light-receiving element with a circular outer periphery and an annular outer light-receiving element arranged concentrically with the inner light-receiving element, and
A sensor constituted by an inner divided light receiving element and an outer divided light receiving element in which the inner light receiving element and the outer light receiving element are equally divided into at least two or more pieces in the circumferential direction, and the light irradiated onto the measurement target by this sensor. an imaging lens that forms an image of the object to be measured; a displacement detection circuit that outputs a signal corresponding to the difference between the output of the inner light receiving element and the output of the outer light receiving element of the sensor; a focal position adjustment device that relatively moves the object and the optical system in the direction of the focal depth of the optical system and stops the relative movement when an output from a displacement detection circuit reaches a reference value; and a divided light receiving element of the sensor. an area signal generation circuit that outputs an area signal when a difference in output between two divided light receiving elements on the same side and facing each other in the diametrical direction exceeds a predetermined value;
An edge signal generation circuit that outputs an edge signal when the output from the displacement detection circuit reaches a reference value on the condition that the area signal is output from the area signal generation circuit. do.

[For production]

The areas of the inner and outer light-receiving elements are calculated in advance so that the signal corresponding to the difference between the output of the inner and outer light-receiving elements of the sensor becomes the reference value when the images are in focus. Adjust both outputs electrically by setting or multiplying the -blade side output by a coefficient.

In this state, if the object to be measured is further away from the focus position, the amount of light received by the outer light-receiving element will increase; conversely, if the object to be measured is closer to the focus position, the amount of light received by the outer light-receiving element will decrease. The difference between both outputs varies with respect to the reference value. Then, the object to be measured and the optical system are moved relative to each other in the depth of focus direction by the focus position adjustment device, and are stopped at the focus position. In other words, the focus will be adjusted automatically.

In addition, when an edge image (for example, a dark image) of the object to be measured crosses the sensor due to relative movement between the object to be measured and the optical system, two of the divided light-receiving elements facing each other in the diametrical direction The difference in output gradually increases. Eventually,
If the difference exceeds a predetermined value, a region signal is output.

At this time, first the amount of light received by the outer light receiving element decreases, and then the amount of light received by the inner light receiving element decreases. Eventually,
When the edge image reaches the center of the sensor, the difference between the output of the inner light-receiving element and the output of the outer light-receiving element becomes the reference value, so at this point, an edge signal is output. In other words, the edges of the object to be measured are detected.

〔Example〕

Embodiments in which the present invention is applied to a microscope will be described below with reference to the drawings.

First Embodiment A first embodiment is shown in FIGS. 1 to 6. FIG. 6 shows the schematic configuration of the microscope of this embodiment. The microscope irradiates light from a first light source 1 consisting of a halogen lamp onto an object to be measured 6 placed on a stage 5 through a condenser lens 2, a half mirror 3, and an objective lens 4. The structure is such that the reflected light is observed through a half mirror 7 and an eyepiece 8. Here, the light source 1, lenses 2, 4.8, and half mirrors 3, 7 constitute an optical system 9 of this embodiment.

A half mirror 11 is arranged on the optical axis of the objective lens 4. A second light M13 made of a laser diode is placed at a position perpendicular to the optical axis passing through the half mirror 11 via a collimating lens 12. Also,
A sensor 14 and an imaging lens 15 for forming an image of the reflected light on the sensor 14 are arranged on the optical axis of the objective lens 4. Note that between the sensor 14 and the imaging lens 15, A mask 16 is placed.

As shown in FIG. 1, the sensor 14 includes an inner light-receiving element 2 and an outer light-receiving element 22, which are arranged concentrically about the optical axis of the objective lens 4. The inner light-receiving element 21 is formed in the shape of a circular center around the outer periphery. The outer light-receiving element 22 is formed into an annular shape, and is equally divided into four parts in the circumferential direction using the X and Y axes, which are perpendicular to each other, as dividing lines. It is composed of Nyoto. The output signals from these inner light receiving elements 21 and the divided light receiving elements 22□ that constitute the outer light receiving element 22
The output signal from ~224 is the amplifier 23.24+~24
After being amplified via the signal processing circuit 4, the signal is supplied to the signal processing circuit 25.

The signal processing circuit 25 is connected to the inner light receiving element 2 of the sensor 11.
The outer light-receiving element 22 includes a displacement detection circuit 31 that outputs a signal corresponding to the difference between the output signal of 1 and the output signal of the outer light-receiving element 22, a tilt detection circuit 41 that detects the inclination of the measurement object 6, and The divided light receiving elements 22□ to 22. A region signal generation circuit 51 outputs a region signal when the difference in output between two diametrically opposed divided light receiving elements exceeds a predetermined value, and a region signal is output from the region signal generation circuit 51. Under these conditions, the AND gate 61 serves as an edge signal generating circuit which outputs an edge signal when the output signal from the displacement detection circuit 31 reaches a reference value.

The displacement detection circuit 31 includes each of the amplifiers 241 to 244.
a sum calculator 32 that calculates the sum of output signals from the divided light receiving elements 22 to 224 inputted through the sum calculator 3;
a multiplier 33 that multiplies the output signal of No. 2 by a coefficient α; and a difference calculator 34 that calculates the difference between the output signal of this multiplier 33 and the output signal from the inner light receiving element 21 inputted through the amplifier 23. , the output signal of this difference calculator 34 is compared with the reference level signal of 0, and when the output signal is smaller than the reference level signal, it is considered a raw signal, and when the output signal is larger than the reference level signal, it is considered a single signal, and both match. and a comparator 35 which outputs a matching signal when the matching occurs.

The output of the comparator 35 is input to a focus position adjustment device 36. The focus position adjustment device 36 is connected to the document table 5.
A motor Mz that moves the lens in the direction of the optical axis of the objective lens 4
and a motor drive control circuit 37 that controls the drive of this motor Mz. Motor drive control circuit 3
7 drives the motor Mz in a direction according to the signal from the comparator 35, and stops the drive when a matching signal is given. In other words, the displacement detection circuit 3
Based on the output from the displacement detection circuit 31, the measurement object 6 and the optical system 9 are moved relative to each other in the direction of the focal depth of the optical system 9, and the relative movement is stopped when the output from the displacement detection circuit 31 reaches a reference value. The inclination detection circuit 41 receives divided light receiving elements 22.22, which are input through amplifiers 241.242.
．． A sum calculator 42 calculates the sum of the output signals from the split light receiving elements 223+221, which are input through the amplifiers 243 and 244, and a sum calculator 43 which calculates the sum of the output signals from the split light receiving elements 223+221, which are input through the amplifiers 243 and 244. a sum calculator 44 that calculates the sum of the output signals from the divided light receiving elements 22++ 224, and a sum calculator 45 that calculates the sum of the output signals from the divided light receiving elements 222 and 223 that are input through the amplifiers 242 and 243. , a difference calculator 46 that calculates the difference between the output signals of the sum calculators 42 and 43;
and a difference calculator 47 that calculates the difference between the output signals of the sum calculators 44 and 45.

Here, the output signals from each of the difference calculators 46 and 47 are used to drive the motors Mx and My that tilt the document table 5 in the X and Y axis directions with respect to the optical axis of the objective lens 4. It is input to the control circuit 48. The motor drive control circuit 48 drives the motors Mx and My in that direction based on the output from the difference calculator 46, 47.

The area signal generation circuit 51 includes an amplifier 24. .

Divided light-receiving elements 221°223 input through 243
a difference calculator 52 that calculates the difference between the output signals from the amplifiers 24□, 24. Split light receiving element 22□ input through
, 224, and output signals from each of the difference calculators 52, 53 as a reference level signal Vref(+).

Window comparators 54 and 55 that compare with Vref(-) and output a region signal when the output signal is not within the reference level signal range, and one of the window comparators 5
and an OR gate 56 which outputs a region signal to the AND gate 61 when a region signal is output from the gates 4 and 55.

The AND gate 61 constituting the edge signal generation circuit operates only when a match signal is output from the comparator 35 while a region signal is being output from either of the window comparators 54 and 55 through the OR gate 56. Outputs an edge signal.

Here, the edge signal output from the ant gate 61 is manually input to a displacement detection device 71 that is linked to the movement of the stage 5. The displacement detection device 71 includes an encoder 72 that generates a pulse signal according to the amount of movement of the workpiece table 5, a counter 73 that counts the pulse signal output from the encoder 72, and a value of the counter 73 that is counted by the edge. The latch circuit 74 latches when a signal is applied.

Next, the operation of this embodiment will be explained.

First, the signal obtained from the inner light receiving element 21 of the sensor I4 is A, and each divided light receiving element 22 constituting the outer light receiving element 22 is
1-22. Assuming that the signals obtained from As shown in Fig. 2 (A), when the object to be measured 6 is located at the focal position of the objective lens 4, that is, when it is in focus, the inner light receiving element is set so that the output signal S becomes the reference value, here O. 21 and each of the divided light receiving elements 221 to 224 constituting the outer light receiving element 22, or the coefficient α of the multiplier 33 is selected in advance.

In addition, here, the arrangement position of the sensor 14 is adjusted so that the signals B1 to B4 from the divided light receiving elements 22 and 224 constituting the outer light receiving element 22 are equal to each other, and the sensor 1
Align the center of 4 with the optical axis.

(Autofocus operation) Now, as shown in FIG. 2(B), if the measurement object 6 is far away from the focal position of the objective lens 4, the amount of light received by the outer light receiving element 22 increases, so the difference calculation is performed. The output signal S<0 is provided from the device 34 to a comparator 35. Then,
A child signal from the comparator 35 is sent to the motor drive control circuit 3.
7, the motor Mz is driven via the motor drive control circuit 37 in the direction in which the stage 5 approaches the focal position. As a result, when the object to be measured 6 reaches the focal position of the objective lens 4, that is, when the object is in focus, the output signal S becomes 0, and the driving of the motor Mz is stopped. In other words, the focus will be adjusted automatically.

On the other hand, as shown in FIG. 2(C), if the object to be measured 6 is located in front of the focal position of the objective lens 4, the amount of light received by the outer light-receiving element 22 decreases, so that the amount of light received by the outer light receiving element 22 decreases. is given to the output signal S〉0 or the comparator 35. Then,
One signal from the comparator 35 is sent to the motor drive control circuit 3.
7, the motor Mz is driven via the motor drive control circuit 37 in the direction in which the stage 5 approaches the focal position. As a result, when the object to be measured 6 reaches the focal position of the objective lens 4, that is, when it is in focus,
Since the output signal S becomes 0, driving of the motor MZ is stopped. In other words, focus is automatically adjusted.

(Edge Detection Operation) Now, as the stage 5 moves in the X and Y axis directions, the edge of the object to be measured 6 (for example, the edge of a dark area) or the upper part (as shown in FIG. 1) is detected as shown in FIG. Let us consider the case of moving in the Y-axis direction). In this case, the signal A obtained from the inner light receiving element 21 changes as shown in FIG. 4(A). In addition, each divided light receiving element 221 to constitute the outer light receiving element 22
Signals B1 to B4 obtained from 224 change as shown in FIG. 4(B).

Then, the signals B1 to B4 obtained from these divided light receiving elements 221 to 224 are sent to the summation unit 3 of the displacement detection circuit 31.
2, and then multiplied by a coefficient α in a multiplier 33, and then input to one input terminal of a difference calculator 34. In other words, one input terminal of the difference calculator 34 is connected to the
) is input. As a result, the difference calculator 34 calculates the difference between the signal A shown in FIG. 4(A) and the signal shown in FIG. 4(C), and outputs the difference as an output signal S.

That is, the signal shown in FIG. 4(D) is output.

In addition, the signal B obtained from the divided light receiving elements 221 and 223
l, B3 are connected to the difference calculator 52, and the divided light receiving elements 22□, 22
Signal B obtained from 4, 2. B and are respectively input to the difference calculator 53. As a result, the difference calculator 52 outputs the signal B
1. The difference between B3 and B3 is provided to the window comparator 54 as an output signal G1. Further, from the difference calculator 53, a signal B
2. The difference between B4 and B4 is provided to the window comparator 55 as an output signal G2.

Here, since the edge of the object to be measured 6 is moving, for example, in the Y-axis direction in FIG. 1, the output signal G1. G2 changes as shown in FIGS. 4(E) and 4(F). Then, each window comparator 54, 55
are the output signals G given from the difference calculators 52 and 53,
G2 and reference signal V ref (+), V ref (-)
The output signal Gl+02 is the reference signal Vref (
↓), outputs H level output signals R1 and R2 only while exceeding Vref(-).

These signals R1 and R2 are applied to one input terminal of an AND gate 61 through an OR gate 56. Therefore, one input terminal of the ant gate 61 is connected to the input terminal shown in FIG.
A region signal R shown in G) is input.

On the other hand, the output signal S output from the difference calculator 34 is
The signal is input to the comparator 35. The comparator 35 is
When the output signal S from the difference calculator 34 crosses the reference level signal of 0, a pulse signal P shown in FIG. 4(H) is applied to the other input terminal of the AND gate 61.

The ant gate 6J outputs an edge signal E of, for example, IO μsec as shown in FIG. 4(I) when the signals applied to both input terminals are both at H level. As a result, the count value of the counter 73 is latched into the latch circuit 74. That is, the value of the counter 73 when the edge of the object to be measured 6 is detected is latched.

(Tilt correction operation) For example, as shown in FIG. 5, when the measurement target 6 is tilted, the amounts of light received by the divided light receiving elements 221 to 224 are different from each other. It is possible to find the slope of Therefore, by correcting the inclination, the inclination of the measurement object 6 can be corrected.

Therefore, in the tilt detection circuit 41, the summation unit 42 uses the divided light receiving elements 22. ．． Signals Bl and B obtained from 22□
The sum of 2 is divided into divided light receiving elements 223,
224, the sum of the signals B3 and B obtained from
4, the sum of the signals Bl and B4 obtained from the divided light receiving elements 221 and 224 is added to the signal B2. The sum of B3,
Calculate each.

The difference calculator 46 calculates the difference between the output signals of the sum calculators 42 and 43, and provides the difference ΔX to the motor drive control circuit 48.

Further, the difference calculator 47 calculates the difference between the output signals of the sum calculators 44 and 45, and provides the difference Δy to the motor drive control circuit 48. Thereby, the motor drive control circuit 48 controls each motor FVI x , M V based on the difference ΔX, Δy.
are driven, and when the differences ΔX and Δy disappear, the driving of the motors Mx and My is stopped.

Therefore, according to this embodiment, the focus can be automatically adjusted using one sensor 14, and the edges of the measurement object 6 can also be detected, so that autofocusing can be performed using one sensor 14. When the mechanism and the edge detection mechanism are configured separately, the structure can be simplified and the number of parts can be reduced. This not only reduces costs but also allows the device to be made more compact. Furthermore, assembly and adjustment are easy, and the reliability of the device can be improved.

In particular, since the autofocus mechanism is composed of the sensor 14, the displacement detection circuit 31, and the focal position adjustment device 36, there is no need to arrange a pair of distance-measuring objective lenses on both sides of the projection lens as in the conventional case. (However, the field of view is not restricted, and there is no problem with the operation of attaching and detaching the object to be measured.

Furthermore, since the outer light receiving element 22 is constituted by divided light receiving elements 221 to 224 which are equally divided into four, these divided light receiving elements 221 to 22. Measurement object 6
can detect the inclination of motors Mx, My
The inclination can be corrected by

Moreover, if the sensor 14 is arranged so that the output signals of the divided light receiving elements 22, 224 are equal to each other, the center of the sensor 14 can be aligned with the optical axis. Therefore,
The attachment of the sensor 14 can be easily adjusted.

In the above embodiment, the case where the edge of the object to be measured 6 moves in the Y-axis direction in FIG. 1 was explained, but when the edge of the object to be measured 6 moves in the Even when moving, edges of the measurement target 6 can be detected in the same manner as described above.

Second Embodiment A second embodiment is shown in FIG. In the explanation of the figure, the same components as in the first embodiment are given the same reference numerals, and the explanation thereof will be omitted or simplified.

In this embodiment, the sensor 14A, the displacement detection circuit 131, the tilt detection circuit 141, and the area signal generation circuit 151 are replaced with the sensor 14A, the displacement detection circuit 3], the tilt detection circuit 41, and the area signal generation circuit 51 in the first embodiment. This embodiment is the same as the first embodiment except that it is changed to .

The sensor 14A includes an inner light receiving element 21 and an outer light receiving element 22 that are arranged concentrically about the optical axis of the objective lens 4, as in the first embodiment. The inner light-receiving element 21 is a semicircular inner divided light-receiving element 21 that has a circular outer periphery and is equally divided into two parts with the X-axis line as a dividing line.
1,212. Outer light receiving element 22
is formed in an annular shape, and the X-axis is the dividing line,
an outer divided light receiving element 22 equally divided into two in the circumferential direction;
．． 222.

The displacement detection circuit 131 includes a sum calculator 132 that calculates the sum of output signals from the divided light receiving elements 211 and 212 inputted through the amplifier 231.23□, an amplifier 24□,
Divided light receiving elements 221 and 222 input through 242
a sum calculator 133 that calculates the sum of the output signals from the sum calculator 133, and a multiplier 1 that multiplies the output signal of the sum calculator 133 by a coefficient α.
34, the output signal of this multiplier 134 and the sum operator 1
A difference calculator 135 calculates the difference with the output signal of 32, and compares the output signal of this difference calculator 135 with a reference level signal of 0, and when the output signal is smaller than the reference level signal, the ↑ signal is set as the output signal. The comparator 136 outputs one signal when the signal is greater than the reference level signal, and outputs a match signal when the two match.

The slope detection circuit 141 includes an amplifier 23. ．． A difference calculator 142 that calculates the difference between the output signals from the split light receiving elements 21+ and 212 inputted through 232, and an amplifier 24□.
Divided light receiving elements 22+, 22□ input through 242
and a difference calculator 143 that calculates the difference between the output signals.

The area signal generation circuit 151 is connected to the slope detection circuit 14.
1 and the difference calculators 142 and 14 of this slope detection circuit 141.
The output signal from 3 is the reference level signal V ref (+)
, window comparators 152 and 153 that output a region signal when the output signal is not within the reference level signal range when compared with V ref (-), and when a region signal is output from either of the window comparators 152 and 153. An OR gate 154 outputs the signal to the anchor 61.

Therefore, in this case, the signals obtained from the inner divided light receiving elements 211.
l, B2, the difference calculator 13 of the displacement detection circuit 131
The output signal S of 5 is S = (A1+A2)-α(
Bl 10B! ). Here, as shown in FIG. 2(A), when the object to be measured 6 is located at the focal position of the objective lens 4, that is, when it is in focus, the output signal S becomes the reference value, here O. , inner divided light receiving element 2
11, 212 and the outer divided light receiving elements 22, 222, or the coefficient α of the multiplier 134 is selected in advance.

(Autofocus operation) Even in the case of this embodiment, if the measurement target 6 is far away from the focal position of the objective lens 4, the amount of light received by the outer light receiving element 22 increases, so the difference calculator 135 outputs Signal S
<0, or conversely, if the object to be measured 6 is located in front of the focal position of the objective lens 4, the amount of light received by the outer light receiving element 22 decreases, so the difference calculator 135 outputs a signal S>O. ,
Each is provided to a comparator 136. Therefore, similarly to the first embodiment, the drive of the motor Mz is stopped via the motor drive control circuit 37 when the stage 5 reaches the focal position. In other words, focus is automatically adjusted.

(Tilt correction operation/edge detection operation) Output signals AI from the inner divided light receiving elements 211 and 212,
The difference ΔX of A2 is calculated by the difference calculator 142, and the difference ΔX between the outer split light receiving elements 22. ．． Difference Δy between output signals Bl and B2 from 222
are calculated by the difference calculator 143, so
The inclination of the measurement object 6 can be corrected based on these differences ΔX and Δy.

At the same time, since these differences ΔX and Δy are input to the window comparators 152 and 153, the edges of the object to be measured 6 can be detected in the same manner as in the first embodiment.

Therefore, the second embodiment also has the advantage of being able to achieve the effects described in the first embodiment and of simplifying the signal processing circuit 25.

In addition, in the above first and second embodiments, the sensor 14.1
Although only the outer light-receiving element 22 constituting 4A is annular, both the inner light-receiving element 21 and the outer light-receiving element 22 may be annular.

Further, in the first embodiment, the outer light receiving element 22 is equally divided into four pieces, but the inner light receiving element 21 may be equally divided into four pieces. At this time, the number of divisions may be four or more. In the second embodiment, both the inner light-receiving element 21 and the outer light-receiving element 22 are equally divided into two parts, but the number of divisions may be two or more.

Note that in each of the above embodiments, reflected light from the measurement object 6 is used, but transmitted light may also be used. Furthermore, although each of the above embodiments has been described as an example applied to a microscope,
The present invention is not limited to this, but can also be applied to projectors and the like.

〔Effect of the invention〕

As described above, according to the present invention, one sensor is used to configure the autofocus mechanism and the edge detection mechanism, so that the conventional autofocus mechanism and edge detection mechanism can be configured separately. The structure can be simplified and the number of parts can be reduced compared to the case where the configuration is made up.

Therefore, costs can be reduced and the device can be made more compact.Furthermore, since there is no need to arrange a pair of distance-measuring objective lenses on both sides of the projection lens, the field of view is not limited. Moreover, there is no problem in attaching and detaching the object to be measured.

[Brief explanation of the drawing]

1 to 6 are diagrams showing a first embodiment of the present invention.
The figure is a circuit diagram mainly showing the electrical configuration, Figure 2 is a diagram to explain the autofocus operation, Figure 3 is a diagram to explain the edge detection operation, and Figure 4 is the signal flow at that time. FIG. 5 is a diagram showing the state when the object to be measured is tilted, and FIG. 6 is a diagram showing the schematic configuration of the microscope. FIG. 7 is a circuit diagram showing a second embodiment of the present invention. 6...Measurement object, 9...Optical system, 14.14A.
...Sensor, 15...Imaging lens, 21...Inner light receiving element, 211.212...Inner divided light receiving element, 22
...Outer light receiving element, 221, 22□, 223, 224
...Outer divided light receiving element, 31,131...Displacement detection circuit, 36...Focus position adjustment device, 41,141...
- Area signal generation circuit, 61...Andcate (edge signal generation circuit). Figure 2

Claims (2)

[Claims] (1) It has an optical system that irradiates light onto the measurement target and forms an image of the measurement target based on the light, and measures from the image formed while moving this optical system and the measurement target relative to each other. An optical measuring device for measuring the dimensions of an object, which has an inner light-receiving element with a circular outer periphery and an annular outer light-receiving element arranged concentrically with the inner light-receiving element, and
Either one of the inner light receiving element and the outer light receiving element is composed of divided light receiving elements divided into at least four equal parts in the circumferential direction; an imaging lens for imaging; a displacement detection circuit that outputs a signal corresponding to the difference between the output of the inner light-receiving element and the output of the outer light-receiving element of the sensor; a focal position adjustment device that moves the optical system relative to the optical system in the depth of focus direction of the optical system, and stops the relative movement when the output from the displacement detection circuit reaches a reference value; and a split light receiving element of the sensor. 2 diametrically opposed
an area signal generation circuit that outputs an area signal when the difference between the outputs of the two divided light-receiving elements exceeds a predetermined value; An optical measuring device comprising: an edge signal generation circuit that outputs an edge signal when the output reaches a reference value; (2) It has an optical system that irradiates light onto the measurement target and forms an image of the measurement target based on the light, and measures from the image formed while moving this optical system and the measurement target relative to each other. An optical measuring device for measuring the dimensions of an object, which has an inner light-receiving element with a circular outer periphery and an annular outer light-receiving element arranged concentrically with the inner light-receiving element, and
A sensor constituted by an inner divided light receiving element and an outer divided light receiving element in which the inner light receiving element and the outer light receiving element are divided into at least two equal parts in the circumferential direction; an imaging lens that forms an image of the object; a displacement detection circuit that outputs a signal corresponding to the difference between the output of the inner light-receiving element and the output of the outer light-receiving element of the sensor; a focal position adjustment device that relatively moves the object and the optical system in the direction of the focal depth of the optical system and stops the relative movement when the output from the displacement detection circuit reaches a reference value; and a divided light receiving element of the sensor. an area signal generation circuit that outputs an area signal when the difference between the outputs of two divided light-receiving elements on the same side and facing each other in the diametrical direction exceeds a predetermined value; an edge signal generation circuit that outputs an edge signal when the output from the displacement detection circuit reaches a reference value on the condition that the displacement detection circuit reaches a reference value.