JP2000227331A - measuring device - Google Patents

Abstract

(57) Abstract: The present invention provides a measuring device capable of performing highly accurate position measurement and the like and reducing a burden on an operator. A height of the surface of a subject is measured based on a principle of triangulation by a laser beam from a laser diode, and a ring-shaped illumination and a light source are measured.
7, the line sensor camera 138 captures a dark-field image or a bright-field image of the subject 101, and inputs the respective luminance image information to the control device 121 to perform position measurement, defect inspection, and the like of the subject 101.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring device for measuring the height and position of a subject.

[0002]

2. Description of the Related Art In recent years, semiconductor components have tended to be more highly integrated and larger in size, and accordingly, BGA packages and the like have been considered as electrical components for mounting bare chips and the like. Recently, even for such a BGA package, a bare chip itself has adopted a bump formed by FC bonding. For such a mounting, a more accurate measurement of the position and height of a minute object is required. I have.

[0003] Therefore, conventionally, regarding the mounting of electric parts using such bumps, a worker measures the position and height while observing one by one using an actual microscope.

In order to capture a high-quality image from a subject, it is necessary to optimally adjust the light amount of a laser diode as a light source.

[0005] Therefore, conventionally, as a method of controlling the amount of laser light of a laser diode, a method of controlling the amount of laser light by varying the power supply voltage of the laser diode or an ND filter in which the transmission amount is sequentially changed by a laser. By disposing it in front of the diode and moving the ND filter from this state to change the amount of transmission to laser light,
A method of controlling the amount of light is used.

[0006]

As in the prior art, with regard to the mounting of electric components using bumps, a method of measuring the height and measuring the position while observing one by one using a stereoscopic microscope by an operator is as follows. It takes a lot of time to perform the appearance inspection of one electric component mounting, which not only reduces the working efficiency but also puts a heavy burden on the operator.

On the other hand, as a method of controlling the amount of laser light of the laser diode, if the power supply voltage of the laser diode is varied, the wavelength of the laser light becomes unstable, making it difficult to capture a high-quality image. Since the amount of transmission with respect to the laser beam changes sequentially, the laser beam corresponding thereto has a cross section of a predetermined size.
The laser light that has passed through the filter has a problem in that the light amount varies at various points in the cross section, and a uniform light amount cannot be obtained.

Further, a polarizing plate is provided in the optical path of the light beam,
By rotating this, there is also a technique to change the intensity of the light beam passing through the polarizing plate.However, when the measurement location or measurement conditions of the subject changes, the optimal brightness also changes, so that a high quality image is always stabilized. There is a problem that it is difficult to make it possible to capture.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a measuring device capable of performing various highly accurate measurements in a short time and reducing a burden on an operator. I do.

It is another object of the present invention to provide a measuring apparatus which can always stably capture an image having an optimum brightness even when the measuring position of the subject or the measuring conditions change.

[0011]

According to one aspect of the present invention, a first measurement for scanning a subject with a laser beam from a laser light source and obtaining at least height information from light reflected from the subject. Means, a second measuring means for irradiating the object with illumination light from an illumination light source to obtain two-dimensional information from reflected light or scattered light from the object, and a laser beam in the first measuring means. There is provided a measuring device comprising: an objective lens provided in an optical path in which the illumination light overlaps with the second measuring means.

In the above-mentioned measuring apparatus, the second measuring means may have a line sensor camera for picking up a dark field image or a bright field image of the subject.

In the above measuring device, the illumination light source is:
It may have an epi-illumination light source.

In the above-mentioned measuring device, the first measuring means may also obtain two-dimensional information of the subject.

[0015] The measuring device may further include means for detecting the amount of reflected light from the subject, and means for controlling the illumination light in accordance with the detected amount of light.

The measuring device may further include a wave plate provided in the optical path of the laser beam and rotatably arranged.

The measuring apparatus further comprises means for detecting the amount of reflected light of the laser light, and means for controlling the laser light by rotating and driving the wave plate according to the detected amount of light. It may be something.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of a detection device to which the present invention is applied. In the figure, reference numeral 101 denotes a subject (sample), and the subject 101 is mounted on a stage 102.

The stage 102 includes a stage driving unit 2
05, it is possible to move in the Z direction, X direction and Y direction (depth direction in the figure) as required.

An objective lens 103 is arranged for a subject 101 on a stage 102. This objective lens 10
Reference numeral 3 uses an object-side telecentric lens designed at infinity.

A ring-shaped illumination 131 is arranged between the objective lens 103 and the stage 102. The ring-shaped illumination 131 is connected to a light source 133 via an optical fiber 132, and emits illumination light from around the objective lens 103 toward the subject 101 by light from the light source 133,
A dark field image of the subject 101 is acquired.

A dichroic mirror 134 is arranged between the objective lens 103 and a galvano mirror 104 described later, and a half mirror 136 is arranged on a reflection optical path of the dichroic mirror 134.

In the transmission optical path of the half mirror 136,
A light source 137 for epi-illumination is arranged. This light source 13
7 is a half mirror 136 and a dichroic mirror 13
Epi-illumination light is emitted toward the subject 101 through the objective lens 4 and the objective lens 103 to acquire a bright-field image of the subject 101.

Here, the dichroic mirror 134 is
As shown in FIG. 2, a low transmission amount (high reflection) is exhibited in each wavelength region of the observation system of the dark field image by the ring-shaped illumination 131 and the bright field image by the light source (for epi-illumination) 137. In addition, a laser diode 1 described later
A material having a characteristic of exhibiting a high transmission amount in the wavelength range of the measurement light from 05 is used.

The dark-field image or bright-field image of the subject 101 passes through the objective lens 103, is reflected by the dichroic mirror 134, and is further reflected by the half mirror 136.
, And transmitted through the imaging lens 135, and the line sensor camera 13 disposed at the condensing position of the imaging lens 135.
8.

Here, the line sensor camera 138 moves the imaging lens 1 from the reflected light path of the dichroic mirror 134.
A dark-field image or a bright-field image of the subject 101 taken through the camera 35 is captured. In addition, the line sensor camera 138 shifts the imaging position of each line from the scanning position of the galvanometer mirror 104, which will be described later, so as to eliminate the influence of the laser beam and to obtain a dark field image or a bright field image satisfactorily. .

The dark-field image picked up by the line sensor camera 138 is input to the position calculation unit 139 of the control device 121 as luminance image information. The position calculation unit 139 calculates the position of the subject 101 from the two-dimensional image information captured by the line sensor camera 138, and executes an optimal image processing algorithm corresponding to illumination and a defect. Inspection of defects such as spots and sizes is possible.

The bright field image picked up by the line sensor camera 138 is also used as brightness image information by the control unit 1.
21. In this case, the control device 121 executes an optimal image processing algorithm corresponding to illumination or a defect from the luminance image information of the line sensor camera 138, and detects a foreign substance, a chip, a spot, a size, and the like of the subject 101. Also have.

By the way, in the optical path between the dichroic mirror 134 and the half mirror 136, the half mirror 2
01 is provided. This mirror 201 is used for the subject 1
The light of the dark field image or the bright field image from 01 is reflected and guided to the light receiving element 203 via the imaging lens 202. The output of the light receiving element 203 is input to the control device 121. In addition,
In the figure, the half mirror 201 is replaced with an icroic mirror 134.
Although the case where it is provided in the optical path between the half mirror 136 and the half mirror 136 is shown, it may be provided in the optical path between the half mirror 136 and the imaging lens 135 instead.

Based on the output of the light receiving element 203, the control device 121 obtains a brightness that enables two-dimensional measurement (the light quantity falls within a preset range (between the upper limit and the lower limit)). As described above, the light amount of the light source 133 or 137 is feedback-controlled.

In addition, a filter 140 is arranged in front of the light source 133 of the ring-shaped illumination 131. This filter 140 converts light from the light source 133 into a single wavelength,
The dark field image of the subject 101 is efficiently reflected by the dichroic mirror 134 and can be captured by the line sensor camera 138. In addition, a filter 141 is arranged on the imaging surface of the line sensor camera 138.
This filter 141 is provided with a laser diode 10 described later.
A part of the laser light from No. 5 reflected on the surface of the subject 101 is further reflected on the dichroic mirror 134,
This is for preventing intrusion into the line sensor camera 138.

On the other hand, a galvano mirror 104 as scanning means is arranged on a pupil plane 103 'of the objective lens 103 via a dichroic mirror 134. The galvanomirror 104 is moved by the mirror driving unit 120 to the pupil plane 10.
It is driven to swing around the center of the pupil of 3 ', reflects the measurement light, and scans the surface of the subject 101 in the X direction and the Y direction (depth direction in the figure) respectively. Is available.

Although the scanning in both the X and Y directions is realized by the swing of the galvanomirror 104, the scanning in the X direction is realized by the swing of the galvanomirror 104 instead, and the scanning in the Y direction is performed. May be realized by moving the stage. Further, the scanning in the X direction may be realized by moving the stage, and the scanning in the Y direction may be realized by swinging the galvanometer mirror 104.

Reference numeral 105 denotes a laser diode, and a collimating lens 10 is provided in front of the laser diode 105.
6, 1/2 wavelength plate 3, polarizing beam splitter 107, 1
Galvanometer mirror 10 described above via wavelength plate 108
4, the laser beam from the laser diode 105 is made parallel by the collimating lens 106, and the half-wave plate 3, the polarizing beam splitter 107, and the quarter-wave plate 108
Through the dichroic mirror 134 and the objective lens 103, using the light reflected by the galvanometer mirror 104 as measurement light.
Light is condensed on the 01 plane.

The half-wave plate 3 has a laser diode 10
5 are arranged substantially orthogonal to the optical axis of the laser light. In this case, it is preferable that the half-wave plate 3 is not at a right angle (90 degrees) with respect to the optical axis of the laser beam, but is inclined at a range of 0 to 10 degrees. This is to prevent the laser beam reflected by the half-wave plate 3 from being irradiated on the light emitting portion of the laser diode 105. The half-wave plate 3 has a circular shape and forms a gear 3a along the periphery thereof. The gear 3a is meshed with a gear 13a of a rotating shaft of a motor 13, and the motor 13 is rotated by using the motor 13 as a drive source. It is possible. The motor 13 is connected to the control device 121, sets the rotation angle of the half-wave plate 3 according to a control signal from the control device 12, and makes the transmission amount of the laser light variable according to the rotation angle. I have.

The dichroic mirror 134 is reflected by the galvanometer mirror 104 as shown in FIG.
It is preferable to set an angle smaller than 45 ° with respect to a plane orthogonal to the optical axis of the objective lens 103 that guides the measurement light to the surface, and in this case, it is set to 35 ° indicated by a solid line. That is, by setting the incident angle to the measurement light to be smaller than 45 °, the loss of the measurement light at the dichroic mirror 134 is minimized.

The measurement light on the object 101 is transmitted to the objective lens 1
The light is converged telecentrically at an arbitrary position on the subject 101 as convergent light having an NA determined by the pupil diameter of 03 and the focal length.

The measurement light reflected on the surface of the object 101 is transmitted to the objective lens 103 and the dichroic mirror 13.
4 and reflected by the galvanomirror 104,
Polarizing beam splitter 10 through quarter-wave plate 108
7, and is reflected by the polarizing beam splitter 107. The luminous flux of the measurement light reflected by the polarization beam splitter 107 is transmitted to the first imaging lens 1.
09 converges on the primary image plane 110.

The light beam passing through the primary image plane 110 passes through a pupil relay lens 112 serving as a second objective lens designed as an infinite system, enters a prism 113 having a half mirror surface 113a, and is reflected by the light beam L1. And the transmitted light flux L2.

The half mirror surface 113a of the prism 113
The light flux L1 reflected by the mirror 113 and the first aperture 11
4, the separator lens 1 serving as the second imaging lens
15, an optical position detecting element (hereinafter referred to as PSD (Position
Sensing Device).

The PSD 116 outputs a current signal that changes depending on the photometric position (spot position) S. The spot position S moves right and left by an amount proportional to a change in the height of the subject 101. This is based on the principle of triangulation described in detail later.

The output from the PSD 116 is used as the brightness image information of the bright field image of the subject 101 by the control unit 1.
21 and to the height calculator 122. The height calculation unit 122 calculates measurement position coordinates x and y on the subject 101 in accordance with the swing angle of the galvanometer mirror 104.
The height z on the surface of the subject 101 is calculated based on the (position coordinates in the X direction and the Y direction) and the spot position signal obtained from the PSD 116.

When irregularities are present on the surface of the object 101, the spot on the PSD 116 has a certain width, and accurate detection may not be performed. In this case, the PSD 116 can detect only the peripheral portion of the light spot, and a considerable detection error occurs.

Therefore, in such a case, it is appropriate to determine that the height of the subject 101 cannot be detected and discard the detection result. In this embodiment, in order to determine whether or not the measurement can be performed, the light beam L2 transmitted through the half mirror surface 113a of the prism 113 is reflected by the mirror surface 113b provided on the rear end side of the prism 113 and the second diaphragm 124.
Through the light receiving element 125.

Then, the output (light quantity) of the divided light receiving element 125 is input to the measurability judging section 126. The measurement availability determining unit 126 determines whether or not the brightness is such that the height can be measured based on the output of the divided light receiving element 125. Specifically, measurable range (lower limit, upper limit)
Is set, and it is determined whether or not the light amount is within the range.

Further, the control device 121 controls the divided light receiving element 1
Based on the output of the laser diode 105, the laser diode 105 is adjusted so that a brightness that allows height measurement can be obtained (so that the light amount falls within a preset range (between the upper limit value and the lower limit value)).
The amount of the laser light is feedback-controlled.

More specifically, the control device 121 starts the motor 13 by sending a control signal, and controls the half-wave plate 3
To rotate. Then, the half-wave plate 3 arranged substantially orthogonal to the laser beam is rotated by a rotation angle set by a control signal from the control device 121, and the transmission of the laser beam is performed according to the rotation angle at this time. The amount is set. Thus, after transmitting through the half-wave plate 3, the stage 102
The laser light radiated as spot light onto the upper object 101 is set to a desired optimum light amount.
As a result, an image of the subject 101 measured at the optimal brightness is obtained on the control device 121 side.

The front focal plane of the first imaging lens 109 is located on the pupil plane of the first objective lens 103 or its conjugate plane 103 '. On the other hand, the separator lens 11
Reference numeral 5 is disposed on the rear focal plane of the pupil relay lens 112 serving as the second objective lens. Therefore, the separator lens 115 is connected to the pupil plane 103 ′ of the first objective lens 103.
And the conjugate position. For this reason, the separator lens 115 forms a measurement spot on the PSD 116 by the luminous flux of the measurement light reflected from all the measurement points and passing through the same portion of the objective pupil plane 103 ′.

The first stop 114 is arranged at the edge of the pupil (at a distance of a fixed distance h from the center) as shown in FIG. In this way, the subject 10
The position of the spot incident on the PSD 116 moves in a desired direction based on the principle of triangulation by the unevenness 1.

The first stop 114 and the second stop 124 facing the divided light receiving element 125 are provided at conjugate positions. By doing so, the luminous flux projected onto the divided light receiving element 125 becomes the PSD 116
It becomes a light beam that has passed through the same part of the object pupil plane 103 ′ as the light beam projected above.

Next, the operation of the embodiment configured as described above will be described.

First, when illumination light is emitted from the periphery of the objective lens 103 toward the subject 101 from the ring-shaped illumination 131, the light reflected by the subject 101 passes through the objective lens 103 as a dark-field image and passes through the dichroic mirror 134.
Then, the light is reflected by the half mirror 136, passes through the imaging lens 135, and is imaged by the line sensor camera 138 disposed at the condensing position of the imaging lens 135.
The dark-field image captured by the line sensor camera 138 is input to the position calculation unit 139 of the control device 121 as luminance image information, and the position of the subject 101 is calculated by the position calculation unit 139. A measurement is taken.

Next, when illuminating light is emitted from the light source 137, the illuminating light is supplied to the half mirror 136 and the imaging lens 13
5, dichroic mirror 134 and objective lens 10
The light is irradiated toward the subject 101 through 3. Then
This time, the light reflected by the subject 101 passes through the objective lens 103 as a bright-field image and passes through the dichroic mirror 134.
Then, the light is reflected by the half mirror 136, passes through the imaging lens 135, and is imaged by the line sensor camera 138 disposed at the condensing position of the imaging lens 135.
Then, the bright field image captured by the line sensor camera 138 is input to the control device 121 as luminance image information, and an optimal algorithm corresponding to various defects of the subject 101 is selected to perform defect detection.

In this manner, the ring-shaped illumination 1
31 and the light source 137 are selectively turned on, and the subject 101
By inputting the luminance image information of the dark-field image or the bright-field image to the control device 121, the position measurement of the object 101 and the inspection accuracy of various defects can be improved, and erroneous detection can be reduced.
The ring-shaped illumination 131 and the light source 137 are simultaneously turned on, and the luminance image information obtained by superimposing the dark-field image and the bright-field image of the subject 101 is input to the control device 121. Various measurements of the subject 101 can be performed by the various algorithm processes described above.

Next, when laser light is emitted from the laser diode 105, the laser light
6. Polarizing beam splitter 107, quarter wave plate 108
The reflected light from the galvanometer mirror 104 is condensed on the surface of the subject 101 through the dichroic mirror 134 and the objective lens 103 as measurement light. The measurement light reflected on the surface of the subject 101 is reflected by the objective lens 103 and the dichroic mirror 1.
34, is reflected by the galvanomirror 104, and
The light is reflected by the polarizing beam splitter 107 through the four-wavelength plate 108 and is reflected by the first imaging lens 109 on the primary image plane 1.
The light is collected at 10. The light beam passing through the primary image plane 110 passes through the pupil relay lens 112, enters the prism 113 having the half mirror surface 113a, and is reflected by the half mirror surface 113a.
The light is condensed on the PSD 116 via the first stop 114 and the separator lens 115.

The output from the PSD 116 is
The control device 1 is used as luminance information of a bright-field image of the subject 101.
21 and to the height calculator 122.

The control device 121 performs various tests on the subject 101 based on the luminance information of the bright-field image of the subject 101, and the height calculator 122 adjusts the angle of the galvanomirror 104 according to the swing angle. A height z on the surface of the object 101 based on the measurement position coordinates x and y on the object 101 and a spot position signal obtained from the PSD 116.
Is calculated.

It should be noted that such height measurement may be performed independently or simultaneously with the acquisition of the luminance image information of the dark field image or the bright field image of the subject 101 described above.

Next, the operation of the height calculator 122 will be described in detail.

First, the principle of the height calculation by the height calculator 122 and the specific method thereof will be described in detail.

FIG. 4 shows only the portion behind the primary image plane 110 in FIG. 1, and the subject image on the primary image plane 110 is newly considered as the subject plane 101 '.

As system parameters, the focal length of the pupil relay lens (second objective lens) 112 is fp, the focal length of the separator lens 115 is fs, the imaging magnification of the primary image is M, and the center of the separator lens 115 is measured from the optical axis. Up to h, pupil relay lens 112 and separator lens 1
15 is D, and the NA of the first imaging lens 109 is NA.
_OB .

The defocus amount (height) Z ′ of the primary image is ZM ² where the height of the subject is Z, and a light spot is formed on the PSD 116 at a position δ from the center. At this time, from the figure, δ is expressed as follows: δ = fs · tanα (1) tanα = h / (b−D) (2)

Therefore, the following equation is derived.

Δ = fs · h / (b−D) (3) h = fp · NA _OB / MP (4) where P is on the pupil of the imaging lens 109 as shown in FIG. The ratio P = Φ / h between the aperture center and the radius of the pupil calculated in step (1).

Next, when b is calculated, 1 / b = (1 / fp)-(1 / (fp + M ² Z)) (5), so that b = fp (fp + M ² Z) / M ² Z ... (6) To summarize these equations,

(Equation 1)

Is obtained. Further, as described above, the distance D between the separator lens 115 and the pupil relay lens 112 is f
p

(Equation 2)

Thus, δ and Z have a completely linear relationship.

The actual measured quantity is δ. Therefore, by transforming equation (8),

(Equation 3)

Is obtained.

Next, based on such a principle, the subject 1
In order to specifically calculate the height Z of the control unit 121, the height calculation unit 122 provided in the control device 121 uses the PSD1
16 receives a spot position signal δ. The height calculator 122 calculates the spot position signal δ, the system parameters f, β, θ, and the mirror driver 12.
Using the measurement position information x and y sequentially input from 0, the height Z of each measurement position is continuously output.

According to this, height measurement having a wide measurement area and a wide dynamic range can be performed at an extremely high speed without moving each optical system and the subject 101 up and down.

Accordingly, the height of the surface of the subject 101 can be measured at a high speed based on the principle of triangulation using the measuring light from the laser diode 105, and the ring-shaped illumination 131 and the light source 137 can be used. By capturing a dark-field image or a bright-field image of the object 101 with the line sensor camera 138 and acquiring respective luminance image information, position measurement, defect inspection, and the like of the object 101 can be performed under optimal conditions corresponding to defects. Therefore, various measurements such as the height measurement and the position measurement can be performed accurately and efficiently in a short time. In addition, the two-dimensional measuring means for obtaining two-dimensional image information such as a dark-field image or a bright-field image and the three-dimensional measuring means (at least a measuring means for measuring height) by triangulation are taken in by the same objective lens 103, Since a plurality of measuring means can be executed without moving the subject 101, the switching of the measuring means does not cause a displacement of the subject 101, and the burden on the operator can be greatly reduced. In addition, a troublesome adjustment mechanism can be eliminated.

In the above-described embodiment, the half-wave plate 3 is disposed on the front surface of the laser diode 105 for generating a laser beam so as to be substantially orthogonal and rotatable with respect to the laser beam. The half-wave plate 3 is rotated by the motor 13 by the set rotation angle, and the transmission amount of the laser light is set according to the rotation angle at this time. Therefore, the power supply voltage of the conventional laser diode is varied. Compared with the conventional ND filter, it is possible to capture high-quality images without causing fluctuations in the wavelength of the laser light. Thus, a uniform amount of laser light can be continuously obtained without causing variation in the amount of light, and stable dimming control of the laser light can be realized.

[0075]

As described above, according to the present invention, various highly accurate measurements can be performed in a short time, and the burden on the operator can be reduced. In addition, an image with an optimal brightness can always be stably captured even when the measurement location and measurement conditions of the subject change.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of an embodiment of the present invention.

FIG. 2 is a diagram illustrating characteristics of a dichroic mirror used in one embodiment.

FIG. 3 is a diagram illustrating an arrangement state of a dichroic mirror used in one embodiment.

FIG. 4 is a schematic diagram for explaining the principle of triangulation in one embodiment.

FIG. 5 is a plan view showing an aperture for a light receiving element according to one embodiment.

[Description of Signs] 3 ... 1/2 wavelength plate 3a ... gear 13 ... motor 13a ... gear 101 ... subject 103 ... objective lens 104 ... galvanomirror 105 ... laser diode 106 ... collimating lens 107 ... polarizing beam splitter 108 ... 1 / 4 wavelength plate 109 imaging lens 110 primary image surface 112 pupil relay lens 113 prism 113 a half mirror surface 113 b mirror surface 114 first aperture 115 separator lens 116 optical position detecting element (PSD: positioning) Sensor) 120 mirror drive unit 121 control device 122 height calculation unit 124 second stop 125 divided light receiving element 126 measurement enable / disable determination unit 131 ring-shaped illumination 132 optical fiber 133 light source 134 dichroic mirror 135 ... imaging lens 136 ... c Fumira 137 ... light source 138 ... line sensor camera 139 ... position calculating unit 140, 141 ... filter 201 ... half mirror 202 ... imaging lens 203 ... light receiving element 205 ... stage driver

Claims (7)

[Claims] A first measuring means for scanning an object with laser light from a laser light source to obtain at least height information from reflected light from the object; and applying illumination light from an illumination light source to the object. Measuring means for obtaining two-dimensional information from reflected light or scattered light from the subject by irradiating the laser light, and an optical path in which the laser light in the first measuring means and the illumination light in the second measuring means overlap each other. A measuring device comprising: an objective lens provided therein. 2. The measuring apparatus according to claim 1, wherein said second measuring means includes a line sensor camera for picking up a dark-field image or a bright-field image of said subject. 3. The measuring device according to claim 1, wherein the illumination light source includes an epi-illumination illumination light source. 4. The measuring apparatus according to claim 1, wherein said first measuring means also obtains two-dimensional information of said subject. 5. The measuring apparatus according to claim 1, further comprising: means for detecting the amount of reflected light from the subject; and means for controlling the illumination light according to the detected amount of light. 6. The measuring apparatus according to claim 1, further comprising a wave plate provided in an optical path of the laser beam and rotatably arranged. 7. The apparatus further comprises means for detecting the amount of reflected light of the laser light, and means for controlling the laser light by rotating and driving the wave plate according to the detected amount of light. The measuring device according to claim 6, wherein