JP2004257882A - Measuring device and measuring method of angle of deviation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drift angle measuring device and a method having high measurement accuracy by using a compact optical system. <P>SOLUTION: This measuring device of the angle of deviation is constituted of a light source 1 for emitting measuring light, a lens 4 for condensing the measuring light emitted from the light source 1 to form a beam, a measuring object 2 where the measuring light enters to measure the angle of deviation, a light receiver 5 arranged on the optical axis of the beam-shaped measuring light, a light shielding plate 7 arranged on the front face on the light source side of the light receiver 5, a guide 8 to which the shielding plate 7 is fixed, a motor 9 for generating a power for moving the light shielding plate 7 in parallel with the light receiver 5 and recognizing the moving quantity, and a gear 10 fixed on the motor and engaged with planar teeth provided on the guide 8, for moving the light shielding plate 7. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a declination measuring apparatus and method, and particularly to a declination measuring apparatus and method capable of measuring an optical path declination defined in an optical component in a compact and accurate manner.
[0002]
[Prior art]
As disclosed in Japanese Patent Application Laid-Open No. 2001-281602, an optical component needs to have a performance of accurately emitting an incident light beam to a predetermined position, and is bent at a predetermined angle with respect to the incident light beam. The relationship with the emitted light beam is defined as an optical path deviation angle.
FIG. 5 is an example of a conventional argument measuring apparatus. FIG. 5 shows a method for simply measuring the optical path deflection angle, which includes a light source 1 that emits measurement light, an object 2 to be measured, and a screen 3 that projects light emitted from the object 2. Constitute.
[0003]
5, the light source 1 irradiates a light beam onto the incident surface of the device under test 2 and projects the beam light emitted from the device under test 2 onto the screen 3. The screen 3 is, for example, a plate-like object with scales arranged at predetermined intervals, and measures the distance that the projected light beam is bent with respect to the optical axis of the DUT 2. At this time, the deflection angle θ of the DUT 2 is defined as follows: A is the shortest distance between the DUT 2 and the screen 3, and B is the distance at which the light beam is bent by the DUT 2.
Declination θ = tan ⁻¹ (B / A)
Can be obtained as
[0004]
[Problems to be solved by the invention]
However, in the conventional declination measuring method, it is necessary to relatively increase the distance B at which the light beam projected from the DUT 2 is bent in order to increase the measurement accuracy. The distance A between the screens 3 also increases. For this reason, the optical system required for the measurement becomes large, and the beam diameter projected on the screen 3 becomes large, and it is difficult to read the above-mentioned minute fluctuation of the distance B. There has been a problem that declination measurement is difficult. Incidentally, the resolution obtained by the conventional declination measuring method is such that when the distance A between the DUT 2 and the screen 3 is 8 m, and when the discriminable distance of the distance B is 2 mm, the declination .theta. 86 '.
The present invention has been made to solve the above-described problem, and has as its object to provide a declination measuring apparatus and method with high measurement accuracy using a compact optical system.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, an argument measuring apparatus and method according to the present invention have the following configurations.
2. The declination measuring apparatus according to claim 1, wherein the light source emits the measurement light, a lens collects the measurement light emitted by the light source to form a beam, and a light receiver disposed on the optical axis of the beamed measurement light. A light-shielding plate having a slit hole on the light source side front surface of the light receiver, a driving unit for moving the light-shielding plate, and a movement amount detection unit for detecting the movement amount of the light-shielding plate, An object to be measured is arranged on the optical axis of the measurement light emitted from the lens, and the optical path deviation of the object to be measured is measured.
[0006]
In the declination measuring apparatus according to claim 2, the light shielding plate is arranged such that a main surface thereof is substantially orthogonal to an optical axis of measurement light emitted from the lens, and is movable in a direction parallel to the main surface. It is configured as follows.
[0007]
According to a third aspect of the present invention, in the declination measuring device, the slit hole is formed such that a longitudinal direction thereof is orthogonal to a moving direction of the light shielding plate.
[0008]
5. The declination measuring method according to claim 4, wherein the light source emits the measuring light, a lens collects the measuring light emitted by the light source to form a beam, and a photodetector arranged on the optical axis of the beamed measuring light. A light-shielding plate having a slit hole on the light-source-side front surface of the light receiver, a driving unit for moving the light-shielding plate, and a moving-amount detecting unit for detecting a moving amount of the light-shielding plate. A method for measuring an optical path deviation of an object placed on an optical axis of measurement light emitted from the lens using an apparatus, wherein the object is not placed on the declination measuring device. Measuring the amount of movement and the output of the light receiver while moving the light-shielding plate, and recognizing the position of the light-shielding plate when the output of the light-receiving device is maximized as a first peak value. In the state where the object to be measured is placed, the light shielding plate is moved. Measuring the amount of movement and the output of the light receiver while recognizing the position of the light shielding plate as the second peak value when the output of the light receiver is maximized, and placing the device under test. The distance from the measured position to the photodetector is A, and the distance from the first peak position to the second peak position is B, and the declination θ of the measured object is given by the following equation: θ = tan ⁻¹ (B / A ).
[0009]
The declination measuring device according to claim 5, wherein a light source for emitting the measuring light, an angle prism disposed on the optical axis of the measuring light emitted by the light source, and an optical axis of the measuring light emitted from the angle prism are arranged on the optical axis. The optical receiver is disposed, and a reference optical component and an object to be measured are sequentially arranged on the optical axis of the measurement light emitted from the light source, and the deviation angle of the object to be measured is measured.
[0010]
The declination measuring method according to claim 6, further comprising: a light source that emits the measurement light; an angle prism disposed on the optical axis of the measurement light emitted by the light source; and an angle prism disposed on the optical axis of the measurement light emitted from the angle prism. A method for measuring a declination error of an object to be measured placed on an optical axis of measurement light emitted from the light source, using a declination measurement device having a light receiver disposed therein, which serves as a reference. Placing an optical component on the declination measuring device, and setting a point at which a measurement light emitted from the light source is imaged on a light receiver as a reference point, and placing an object to be measured on the declination measuring device Measuring a distance between an imaging point where the measurement light emitted from the light source is formed on a light receiver and the reference point; and an optical component serving as a reference based on the measured distance. Calculating a declination error of the DUT with respect to the declination.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.
FIG. 1 is a functional diagram showing a first embodiment of an argument measuring apparatus and method according to the present invention. In the present embodiment, a light source 1 for emitting measurement light, a lens 4 for condensing the measurement light emitted from the light source 1 and forming a beam, an object 2 for receiving the measurement light and measuring a deflection angle, A light receiving device 5 arranged on the optical axis of the measured light, a light shielding plate 7 having a slit hole 6 arranged on the front surface of the light receiving device 5 on the light source side, a guide 8 to which the light shielding plate 7 is fixed, and the light shielding plate 7 And a motor 9 that serves as a power for moving the light in parallel to the light receiver 5 and recognizes the amount of movement. The motor 9 is fixed to the motor 9 and meshes with plate-shaped teeth provided on the guide 8 to move the light shielding plate 7. And the gear 10 to be driven. Further, the light shielding plate 7 is disposed so as to be substantially orthogonal to the optical axis of the measurement light emitted from the lens, and moves in parallel with the light receiver 5.
[0012]
The operation of FIG. 1 will be described. The optical system is adjusted so that the measurement light emitted from the light source 1 is incident on the lens 4 and condensed, and forms an image on the light receiver 5. Therefore, first, in order to obtain the reference data of the measurement system for the declination measurement in the measurement, the light shielding plate 7 is moved in a state where the object to be measured is not arranged, and the amount of the measurement light received by the light receiver 5 is measured. . A personal computer (not shown) or the like is connected to the light receiver 5, and the measured data of the amount of movement of the light shielding plate 7 and the amount of received light is input and graphed, and reference data is output.
[0013]
The light-shielding plate 7 used in the present embodiment has a slit hole 6 having a length of about 6 mm and a width of about 0.1 mm at the center of a thin metal plate or the like. The intensity of the measurement light passing through the slit hole 6 is detected by the light receiving device 5 when the measuring light is moved in parallel with the light receiving device 5. The motor 9 is a power source for moving the light-shielding plate 7 at a predetermined interval. The motor 9 has a function of rotating by an applied pulse. And the amount of movement of the light shielding plate 7 is recognized.
[0014]
Therefore, a gear 10 is fixed to the motor 9, and when the motor 9 rotates, the plate-shaped guide 8 meshing with the gear 10 moves in a predetermined step. The plate 7 moves parallel to the light receiver 5. The slit hole 6 moves in the range between the slit base point and the slit end point shown in FIG. 1, the position where the reference measurement light forms an image on the light receiver 5, and the measurement light emitted from the device under test 2 is transmitted to the light receiver 5. The image forming position is included in this moving range.
[0015]
Next, after the reference data is collected, the device under test 2 is placed at a predetermined position of the declination measuring device, and is controlled by the number of pulses input to the motor 9 from the slit base point to the slit end point, as in the case of the reference data collection. The light shielding plate 7 is moved at predetermined intervals, and the amount of light received by the light receiver 5 at that time is measured. The light receiver 5 is connected to a personal computer (not shown) or the like, and inputs the movement data of the light-shielding plate 7 and the measurement data of the light reception amount, graphs them, and outputs the light reception characteristics.
[0016]
FIG. 2 is a graph in which reference data and measured data are graphed in the first embodiment of the argument measuring apparatus and method according to the present invention. FIG. 2 shows that, as described above, the slit hole is moved at a predetermined interval from the slide base point to the slit end point when the object is not arranged (reference data) and when the object is arranged (measurement data). FIG. 6 is a graph of the amount of light received by the light receiver when the light is detected. FIG. 2A shows the amount of received light detected from the slit base point to the slit end point, and FIG. 2B is an enlarged view of the peak points of the reference data and the measured data. In the enlarged view of FIG. 2B, L indicates a step distance when the slit hole is moved. Then, when the distance B between the reference data and the peak value of the data to be measured is obtained, the distance B indicates the distance at which the measurement light is bent by arranging the object to be measured in the optical measurement system. Is the shortest distance between the DUT and the light receiver as shown in FIG.
Declination θ = tan ⁻¹ (B / A)
Can be obtained by
[0017]
When the distance A is set to 100 mm and the distance L is set to 1 μm, the minimum resolution in this embodiment can be about 0.04 ′, which enables highly accurate declination measurement, and reduces the distance between the object to be measured and the light receiver. Since it can be shortened, a compact argument measuring device can be configured.
[0018]
FIG. 3 is a functional diagram showing a second embodiment of the argument measuring apparatus and method according to the present invention. In the present embodiment, a light source 1 for emitting measurement light, an object to be measured 2 for entering measurement light and measuring a deflection angle, an angle prism 11 arranged on an optical axis of the measurement light emitted from the light source, and a measurement light And a CCD camera 12 serving as a light receiver for forming an image.
3 will be described. The measuring light emitted from the light source 1 is emitted to the angle prism 11 after being incident on the DUT 2. The angle prism 11 is for enlarging the optical path deviation angle θ generated in the device under test 2 by an arbitrary magnification α. Is emitted.
[0019]
Next, a method of calculating the declination will be specifically described using the measurement light emitted to the CCD camera. The present embodiment is not intended to directly measure the angle of deviation of the object to be measured, but has a small error in the angle of deviation of the object to be measured as compared with the angle of deviation of the reference optical component. This is for accurately measuring whether or not it is being performed. Therefore, when measuring the declination, first, a reference optical component having a known declination is inserted into the measurement system instead of the object to be measured, and the measurement light is irradiated to the reference optical component, and is passed through the angle prism. Then, an image is formed at the center of the monitor of the CCD camera, and this image forming point is used as a reference value. Next, the object to be measured is inserted into the measuring system in place of the reference optical component, the measuring light is irradiated on the object to be measured, and an image is formed on the monitor of the CCD camera via the angle prism. By measuring the difference in distance between the reference optical component and a known reference value, the deviation error between the reference optical component and the object to be measured is identified. Therefore, a description will be given of the relationship between the difference between the two angles and the distance between the reference value and the measured value formed on the CCD camera using a specific calculation example.
[0020]
FIG. 4 shows how measurement light is emitted in the second embodiment of the declination measuring apparatus and method according to the present invention.
In a state where the angle prism is not inserted, the distance at which the measuring light is bent when the measuring light passes through the object to be measured and is emitted to the CCD camera is S1, the distance from the object to the CCD camera is L1, and the polarization at that time is L1. The angle is defined as θ2−θ1. With the angle prism inserted into the measurement system, the distance by which the measurement light is bent when the measurement light is transmitted to the object to be measured and then emitted to the CCD camera through the angle prism is represented by S2. When the distance from the angle prism to the CCD camera is L4, and θ3, θ4, and θ5 are the angles shown in FIG. 4, the following relational expression can be obtained.
S2 = L4 × tan (θ5−θ4) (1)
If the refractive index of the atmosphere is n0, the refractive index of the device under test is n1, and the refractive index of the angle prism is n2,
n0 × sin θ5 = n2 × sin (θ4 + θ3) (2)
n2 × sin θ3 = n0 × sin (θ2−θ1) (3)
n0 × sin θ2 = n1 × sin θ1 (4)
Holds, θ5 is calculated from the equations (1), (2), (3), and (4) as follows:
θ5 = sin ⁻¹ ((n1 / n0) × sin (θ4 + sin ⁻¹ ((n0 / n2
) × sin (sin ⁻¹ ((n1 / n0) × sin θ1) −θ1)))) (5)
Required by
[0021]
Therefore, first, when a reference optical component is inserted into the measurement system, this is taken as calculation example A, where L1 = 1000 mm (L2 = 50 mm, L3 = 10 mm, L4 = 940 mm), n0 = 1, and n1 = n2 = When 1.51 and θ1 = 1 ° and θ4 = 30 ° and θ5A is obtained, θ5A ≒ 49.70 ° is obtained from Expression (5).
From equation (1), S2A is S2A 式 336.57 mm.
Is required.
[0022]
On the other hand, an object to be measured is next inserted into the measurement system, and this is used as a calculation example B. L1 = 1000 mm (L2 = 50 mm, L3 = 10 mm, L4 = 940 mm), n0 = 1, n1 = n2 = 1.51, Similarly, when θ1 = 1.05 ° and θ4 = 30 °, θ5B is obtained. From Expression (5), θ5B ≒ 56.56 °
From equation (1), S2B is S2B ≒ 469.9 mm.
Is required. Therefore, when the difference between both calculation examples A and B is obtained, S2B−S2A = 133.33 mm
When the angle of deviation of the object to be measured has an angle difference of 0.05 ° (3 ′) with respect to the angle of deviation of the reference optical component, it is 133.33 mm when converted to the distance of S2. Therefore, since the distance of S2 with respect to each angle difference can be converted based on the above-described calculation example, when the object to be measured is inserted and the measurement light is imaged on the CCD camera in this measurement system, this image formation is performed. By measuring the distance between a point and the reference point, it is possible to measure how much the deviation angle of the measured object has with respect to the reference optical component.
[0023]
Next, how the resolution is improved in the second embodiment as compared with the case where the angle prism is not inserted into the measurement system as in the conventional argument measurement method will be described.
Therefore, in the case where the angle prism is not inserted, the distance to the angle difference is calculated using FIG. 4 in the same manner as the calculation method described above.
When the measuring light is transmitted through the object to be measured and is emitted to the CCD camera, the distance at which the measuring light is bent is S1, the distance from the object to the CCD camera is L1, and the declination at that time is θ2−θ1. Can be expressed as
S1 = L1 × tan (θ2−θ1) (6)
Also, assuming that the refractive index of the atmosphere is n0 and the refractive index of the device under test is n1,
n0 × sin θ2 = n1 sin θ1 (7)
Is satisfied, S1 is obtained from Expressions (6) and (7).
S1 = L1 × tan (sin ⁻¹ (n1 × sin θ1 / n0)) (8)
Required by
[0024]
Therefore, first, when a reference optical component is inserted into the measurement system, this is set as a calculation example C, where L1 = 1000 mm, n0 = 1, n1 = 1.51,
When S1C is obtained by setting θ1 = 1 °, S1C ≒ 26.36 mm is obtained from Expression (8).
Is required.
[0025]
On the other hand, next, an object to be measured is inserted into the measurement system, and using this as a calculation example D, S1D is obtained in the case of L1 = 1000 mm, n0 = 1, n1 = 1.51, and θ1 = 1.05 °. From equation (8), S1D ≒ 27.68 mm
Is required. Therefore, when the difference between them is obtained, S1D-S1C = 1.32 mm
When the angle of deviation of the object to be measured has an angle difference of 0.05 ° (3 ′) with respect to the angle of deviation of the reference optical component, it is 1.32 mm when converted into the distance of S1. Therefore, the resolution is greatly deteriorated as compared with the resolution when the angle prism is inserted.
[0026]
From the above calculation results, by inserting the angle prism having the angle θ4 into the measurement system, the relationship between the amount of declination and the distance is expanded, and more accurate declination measurement becomes possible. Further, the amount of expansion of the relationship of the distance to the amount of declination can be adjusted by the angle θ4 of the angle prism.
In the second embodiment, a CCD camera is used to measure the distance between the imaging points. However, a plate-like screen may be prepared to measure the distance between the projected imaging points.
Therefore, also in the second embodiment, a compact and highly accurate declination measuring device can be realized.
[0027]
【The invention's effect】
As described above, according to the first and fourth aspects of the present invention, a light-shielding plate having a slit hole is provided on the front surface of a light receiver, and the light-shielding plate is moved to obtain a peak value of a received light amount. By determining the distance, it is possible to configure a highly accurate declination measurement and a compact measurement system, and to exhibit a remarkable effect in measuring the declination of an optical component.
[0028]
According to the fifth and sixth aspects of the present invention, the angle of deviation is enlarged by inserting an angle prism into the measurement system, and a small error of the angle of deviation of the object to be measured with respect to the angle of deviation of the reference optical component. Can be measured with high accuracy, and a remarkable effect can be exhibited in measuring the deflection angle of the optical component.
[Brief description of the drawings]
FIG. 1 is a functional diagram showing a first embodiment of a declination measuring apparatus and method according to the present invention.
FIG. 2 is a graph in which reference data and measured data are graphed in the first embodiment of the declination measuring apparatus and method according to the present invention.
FIG. 3 is a functional diagram showing a second embodiment of the argument measuring apparatus and method according to the present invention.
FIG. 4 shows how measurement light is emitted in a second embodiment of the declination measuring apparatus and method according to the present invention.
FIG. 5 is an example of a conventional argument measuring apparatus.
[Explanation of symbols]
1. Light source, 2. DUT,
3. Screen, 4. Lens,
5 ・ ・ Receiver 、 6 ・ ・ Slit hole 、
7 ... light shield plate, 8 ... guide,
9 ... motor, 10 ... gear,
11. Angle prism, 12. CCD camera

Claims (6)

A light source for emitting measurement light, a lens for condensing and beaming the measurement light emitted by the light source, a light receiver arranged on the optical axis of the beamed measurement light, and a slit on the light source side front surface of the light receiver A light-shielding plate having holes, a driving unit for moving the light-shielding plate, and a movement amount detecting unit for detecting a movement amount of the light-shielding plate,
A deflection angle measuring apparatus, wherein an object to be measured is arranged on an optical axis of measurement light emitted from the lens, and an optical path deviation of the object to be measured is measured. 2. The light-shielding plate according to claim 1, wherein the light-shielding plate is arranged such that a main surface thereof is substantially orthogonal to an optical axis of measurement light emitted from the lens, and is movable in a direction parallel to the main surface. The declination measuring device according to the above. The deflection angle measuring device according to claim 1, wherein the slit hole is formed such that a longitudinal direction thereof is orthogonal to a moving direction of the light shielding plate. A light source for emitting measurement light, a lens for condensing and beaming the measurement light emitted by the light source, a light receiver arranged on the optical axis of the beamed measurement light, and a slit on the light source side front surface of the light receiver A light shielding plate having a hole, a driving means for moving the light shielding plate, and a deflection angle measuring device including a movement amount detecting means for detecting a movement amount of the light shielding plate,
A method for measuring an optical path deviation angle of an object to be measured placed on an optical axis of measurement light emitted from the lens,
In a state where the object to be measured is not placed on the declination measuring device, the amount of movement and the output of the light receiver are measured while moving the light shielding plate, and the output of the light receiver is maximized. Recognizing the position of the light blocking plate as a first peak value;
In the state where the object to be measured is placed, the moving amount of the light shielding plate and the output of the light receiver are measured while moving the light shielding plate, and the position of the light shielding plate when the output of the light receiver is maximized is set to the second position. Recognizing as a second peak value;
The distance from the position on which the object is placed to the photodetector is A, and the distance from the first peak position to the second peak position is B, and the argument θ of the object is expressed by the following equation θ = tan ^-1 (B / A)
Calculating on the basis of the angle of deviation. A light source that emits measurement light, an angle prism disposed on the optical axis of the measurement light emitted by the light source, and a light receiver disposed on the optical axis of the measurement light emitted from the angle prism,
A declination measuring apparatus characterized by sequentially arranging an optical component serving as a reference and an object to be measured on an optical axis of measurement light emitted from the light source and measuring a deviation angle of the object to be measured. Declination measurement comprising a light source for emitting measurement light, an angle prism arranged on the optical axis of the measurement light emitted by the light source, and a light receiver arranged on the optical axis of the measurement light emitted from the angle prism With the device,
A method for measuring a deviation error of an object to be measured placed on an optical axis of measurement light emitted from the light source,
A reference optical component is placed on the declination measuring apparatus, and a step of forming a measurement light emitted from the light source on a light receiver as a reference point, and
Placing the object to be measured on the declination measuring apparatus, measuring the distance between the imaging point and the reference point where the measurement light emitted by the light source is imaged on a light receiver,
Calculating a deviation error of the object to be measured with respect to a deviation of the reference optical component based on the measured distance.

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