JP5646861B2 - Measuring device and measuring method - Google Patents

Description

  The present invention relates to a measuring device and a measuring method.

There is a measuring apparatus that projects a light beam onto a measurement target having a continuous curved surface and measures the curved surface shape of the target surface from the relationship between the projected light and the reflected light from the target surface (see Patent Document 1).
[Prior art documents]
[Patent Literature]
[Patent Document 1] Japanese Patent Application Laid-Open No. 2003-344028

  However, since the measuring device with high accuracy has a narrow measuring range, the dimension of the measuring object is limited. On the other hand, if an optical system for displacing the light beam is added to widen the measurement target range, the measurement accuracy decreases.

  Therefore, in order to solve the above-described problem, as a first aspect of the present invention, a projection unit that projects a light beam toward the target surface, and a light beam reflected by the target surface is received and the local shape of the target surface is determined. A specific part to be identified, a translation part that translates the light beam while maintaining the projection angle of the light beam, and a local shape that is sequentially identified by the specific part as the light beam is translated, When the calculation unit that calculates the shape, the changing unit that changes the projection angle of the light beam, and the changing unit changes the projection angle from the first angle to the second angle, the specific unit is moved to the target surface by the first angle. And a control unit that projects a light beam to the projection position at a second angle and specifies the local shape at the projection position again, and provides a measurement device that measures the shape of the target surface.

  Further, as a second aspect of the present invention, a projecting step of projecting a light beam toward the target surface, a specifying step of receiving the light beam reflected by the target surface and specifying the local shape of the target surface, and light A translation stage that translates the light beam while maintaining the beam projection angle and sequentially accumulates the local shape, a calculation stage that calculates the continuous shape of the target surface from the accumulated local shape, and reflection at the target surface When the projection angle is changed from the first angle to the second angle, the light beam is projected by the second angle to the projection position on the target surface by the first angle. A re-specification step of re-identifying the local shape at the projection position, and a measurement method for measuring the shape of the target surface is provided.

  The above summary of the present invention does not enumerate all necessary features of the present invention. Further, a sub-combination of these feature groups can be an invention.

1 is a schematic front view showing the structure of a measuring device 100. FIG. 3 is a flowchart showing a measurement procedure using the measurement apparatus 100. 3 is a schematic front view showing the operation of the measuring apparatus 100. FIG. 3 is a schematic front view showing the operation of the measuring apparatus 100. FIG. 3 is a schematic front view showing the operation of the measuring apparatus 100. FIG. 3 is a schematic front view showing the operation of the measuring apparatus 100. FIG. 3 is a schematic front view showing the operation of the measuring apparatus 100. FIG. 6 is a schematic front view showing another structure of the measuring device 100. FIG. 6 is a schematic front view showing another structure of the measuring device 100. FIG. 6 is a schematic plan view showing another structure of the measuring device 100. FIG. 1 is a schematic front view showing the structure of a measuring device 100. FIG.

  Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all the combinations of features described in the embodiments are essential for the solving means of the invention.

  FIG. 1 is a schematic front view showing the structure of the measuring apparatus 100. The measuring apparatus 100 includes a frame body 110, an autocollimator 120 attached to the frame body 110, a translation table 130, a rotary table 140, and an optical system 150.

  The frame body 110 includes a horizontal surface plate 116, a plurality of support columns 114 standing on the surface plate 116, and a guide rail 112 supported horizontally by the support columns 114. The guide rail 112, the support column 114, and the surface plate 116 are each formed of a highly rigid material. As a result, the frame 110 is not deformed even when a reaction force due to the operation of the measuring apparatus 100 described later is applied. A sample 160 whose shape is to be measured by the measuring apparatus 100 is placed on the upper surface of the surface plate 116.

Autocollimator 120 is supported horizontally on one of the struts 114, it emits a horizontal light beam B _1. Light beams _{B 1} is sequentially reflected on the fixed mirror 154 and turning mirror 152 will be described later, it is projected to the projection position _{P 1} of the sample 160 upper surface.

Incidentally, autocollimator 120 receives the reflected light of the light beams B ₁ which is projected on the sample 160, the light beam B ₁ is to measure the tilt of the sample 160 surface in has been projected position P ₁ projection. In other words, the measurement range of the autocollimator 120, the reflected light of the light beams B ₁ emitted, autocollimator 120 itself is limited to a range that can be received.

  The translation table 130 is supported by the guide rail 112 and is driven by a drive unit (not shown) to translate horizontally along the guide rail 112. Here, the guide rail 112 and the translation table 130 are provided with a linear scale and a linear encoder (not shown), and the amount of movement of the translation table 130 can be detected.

  The translation table 130 is equipped with a rotary table 140 and an optical system 150. When the translation table 130 moves, the rotary table 140 and the optical system 150 also move with the translation table 130.

The optical system 150 includes a rotating mirror 152 and a fixed mirror 154. The fixed mirror 154 is directly fixed to the translation table 130, and translates together when the translation table 130 moves. The fixed mirror 154 reflects the horizontal light beam B ₁ emitted from the autocollimator 120 toward the rotary mirror 152 regardless of the position of the translation table 130.

The rotary mirror 152 is fixed with respect to the rotary table 140 mounted on the translation table 130. The rotary table 140 rotates around a rotation axis orthogonal to the light beam B ₁ and the translation direction of the translation table 130. The rotary mirror 152 has a reflecting surface parallel to the rotation axis of the rotary table 140.

  A rotary scale and a rotary encoder (not shown) are disposed between the rotary table 140 and the translation table 130. Thereby, the rotation angle when the turntable 140 rotates can be measured.

Thereby, when the rotary table 140 rotates, the rotary mirror 152 can change the projection angle of the light beam B ₁ received from the fixed mirror 154 with respect to the sample 160. When changing the projection angle of the light beam B _1, also changes the reflection angle of the reflected light of the light beams B ₁ by the sample 160. However, when changing the projection angle of the light beam _{B 1,} the projection position _{P 1} of the light beams _{B 1} to the sample 160 on the platen 116 is also changed.

When the translation table 130 is translated with the rotary table 140 fixed, the light beam B ₁ can be translated while maintaining the projection angle of the light beam B ₁ with respect to the sample 160. Thereby, the irradiation position P ₁ can be moved while maintaining the irradiation angle of the light beam B ₁ with respect to the sample 160.

Here, by combining the pair of reflecting mirrors of the rotating mirror 152 and the fixed mirror 154 to guide the light beam B ₁ , the change in the tilt accompanying the translation of the translation table 130 due to the unevenness of the guide rail 112 or the like can be reduced. Can cancel autonomously. Thereby, the measurement precision at the time of measuring while moving the translation table 130 is maintained.

  The control unit 118 controls the operations of the translation table 130 and the rotary table 140. When the translation table 130 is translated and when the rotary table 140 is rotated, the control unit 118 measures and holds the movement amount and the rotation amount. Further, the control unit 118 calculates the shape of the sample 160 based on the measurement result of the autocollimator 120 as described later.

  FIG. 2 is a flowchart showing a measurement procedure using the measurement apparatus 100. 3 to 7 show the operation of the measuring apparatus 100 for each stage. The measurement procedure shown in FIG. 2 will be described below with reference to FIGS. 3 to 7 in order. 2 to 7, the same elements as those in FIG. 1 are denoted by the same reference numerals and redundant description is omitted.

First, the sample 160 is placed on the platen 116, and then start the auto-collimator 120, as shown in FIG. 1, via a fixed mirror 154 and turning mirror 152, the projection light beams _{B 1} to the sample 160 (Step S101). Here, the control unit 118 checks the projected light beam _{B 1,} whether light reflected by a sample 160 is received by the autocollimator 120 (step S102).

FIG as shown in 3, if the light reflected by the sample 160 is received by the autocollimator 120 (step S102: YES), the autocollimator 120 is, the inclination of the surface of the sample 160 at the position where the light beams _{B 1} is projected , And the control unit 118 records the measurement result (step S103). Thus, local shape of the light beam B ₁ is the sample 160 in has been projected position P ₁ projection is identified.

Furthermore, when the can identify local shape of the sample 160 in the projection position P _1, the control unit 118 records the projection position can be identified the local shape at the end. Furthermore, every time a local shape is specified in the following steps, the control unit 118 updates the projection position (step S104).

Incidentally, the projection position of the light beams B ₁ to the sample 160, for example, can be recorded by a beam markers projected from another light source to the projection position of the light beams B _1. Further, based on the projection angle of the position and the light beams B ₁ of the translation table 130, the control unit 118 calculates the projection position of the light beam B _1, the control unit 118 may hold the value.

Next, as shown by the arrow _{M 1} in FIG. 4, the control unit 118 moves along the translation table 130 to the guide rail 112 (step S105). After moving the translation table 130, checks whether or not the light beams B ₁ was projected is projected on the sample 160 (step S106).

If the projection position of the light beams _{B 1} is too as a range in the presence of the sample 160 (step S106: NO) ends the shape measurement of the sample 160. Incidentally, the projection position of the light beam B ₁ is that too through the existence range of the sample 160 may be predicted from the known specification of the sample 160, the measurement result by the autocollimator 120 is changed suddenly large Can also be detected.

If after movement of the translation table 130 also has the light beams _{B 1} is projected on the sample 160 (step S106: YES), by repeating steps S102 to step S106, for example, as shown in FIG. 4, the projection position From P ₁ to P ₂ , the local inclination of the surface of the sample 160 can be measured and accumulated one after another. At this time, the turntable 140 is fixed, projection angle with respect to the sample 160 of the light beams B ₁ is kept at an angle alpha.

However, for example, as shown in FIG. 5, when the projection position of the light beam B ₁ moves to P ₃ and the inclination of the surface of the sample 160 changes greatly, the reflected light of the light beam B ₁ is received by the autocollimator 120. (Step S102: NO) In such a case, the control unit 118 rotates the rotary table 140 to change the angle of the rotary mirror 152 to the angle β as indicated by an arrow R in FIG. 6 (step S107).

Furthermore, the control unit 118, while maintaining the projection angle to the angle beta, as shown by arrow M ₃ in FIG. 7, by moving the translation table 130, the projection position with respect to the sample 160 of the light beam B _1, local fit the projection position P _2, which is recorded as the last projection position can be identified the shape (step S108). In this state, again, checks whether the light reflected by a sample 160 of the light beams _{B 1} is received by the autocollimator 120 (step S102).

Hereinafter, the reflection light of the light beams B ₁ is received by the autocollimator 120, by repeating steps S102, S107 and S108 described above, a new projection angle, the projection position P which can identify the last local shape _{From 2} , the shape specification of the sample 160 can be resumed. Thus, the range to the presence of the sample 160 to the projection position of the light beam B ₁ is disengaged, can be identified repeatedly local shape of the surface of the sample 160. By integrating the local shape thus obtained, the surface shape of the sample 160 can be measured accurately and continuously.

  In the above example, it is described that the change of the projection angle (step S107), the alignment of the projection position (step S108), and the reception confirmation of the reflected light (step S102) are repeated. However, since the surface shape of the sample 160 is smoothly continuous in many cases, the translation table 130 required for the projection angle to be set next and the projection position matching according to the projection angle is determined from the immediately preceding measurement content. The amount of movement can be predicted.

  In the above description, the procedure for changing the projection angle after the autocollimator 120 stops receiving reflected light has been described. However, the projection angle may be changed when the measured value of the surface of the sample 160 by the autocollimator 120 approaches the measurement limit of the autocollimator 120 to some extent. Thereby, the local shape of the sample 160 can be specified with higher accuracy using the vicinity of the center of the measurable range of the autocollimator 120.

  FIG. 8 is a schematic front view showing another structure of the measuring apparatus 100. The measurement apparatus 100 shown in FIG. 8 has the same structure as the measurement apparatus 100 shown in FIG. 1 except for the parts described below. Therefore, common elements are denoted by the same reference numerals, and redundant description is omitted.

The measuring apparatus 100 shown in FIG. 8 is unique in that it includes a pair of laser length measuring devices 172 and 174 instead of the autocollimator 120. That is, the pair of laser length measuring instruments 172 and 174 emit parallel light beams B ₃ and B ₄ at a slight interval, and irradiate the sample 160 via the fixed mirror 154 and the rotating mirror 152.

Each of the pair of laser length measuring devices 172 and 174 can measure the distance to the measurement target, but the differential laser length measuring device 170 can be formed by adopting the above configuration. Thereby, the measurement errors of the individual laser length measuring machines 172 and 174 are canceled out, and the distances to the projection positions of the light beams B ₃ and B ₄ can be specified with high accuracy. Therefore, by accumulating and integrating the projection positions repeatedly measured along the surface of the sample 160, the shape of the surface of the sample 160 can be measured with high accuracy.

In the case of this measuring apparatus 100 as well, when the projection angle of the light beams B ₃ and B ₄ with respect to the sample 160 is changed, the light beam is projected to the projection position on the surface of the sample 160, which is the same as the position where the shape was finally specified. B ₃ and B ₄ are projected to restart measurement. Thereby, it is possible to measure a surface shape in which high measurement accuracy is continuously continued.

In the measurement apparatus 100 as described above, the interval between the two light beams B ₃ and B ₄ generated by the pair of laser length measuring devices 172 and 174 can be changed. Therefore, when the measurement accuracy required for the measurement is low, the interval between the light beams B ₃ and B ₄ can be increased to shorten the time required for the measurement work. The same effect can be obtained by widening the measurement interval of the local shape.

  FIG. 9 is a schematic front view showing still another structure of the measuring apparatus 100. Note that the measurement apparatus 100 shown in FIG. 9 also has the same structure as the measurement apparatus 100 shown in FIG. 1 except for the parts described below. Therefore, common elements are denoted by the same reference numerals, and redundant description is omitted.

The measuring apparatus 100 shown in FIG. 9 has a characteristic feature in that another autocollimator 124 is mounted on the rotary table 140 on the translation table 130 instead of the rotary mirror 152. The light beam B ₁ emitted from the autocollimator 124 is directly projected onto the sample 160 on the surface plate 116.

The measuring apparatus 100 also includes a fixed mirror 156 fixed to the translation table 130 and an autocollimator 122 fixed horizontally to one of the columns 114. The fixed mirror 156 reflects the light beam B ₅ emitted from the autocollimator 122 and returns it to the autocollimator 122 again. Thereby, the inclination etc. which arise in the autocollimator 124 with the movement of the translation table 130 are detected by the autocollimator 122, and the measurement value by the autocollimator 124 can be corrected.

Furthermore, even if the measuring apparatus 100, when rotating the rotary table 140 to change the projection angle of the light beams B ₁ to the sample 160, the position can be specified locally shape of the sample immediately before, again light The beam B ₁ is projected, and the local shape at the same position is specified by the light beam B ₁ having a different projection angle. Thereby, it is possible to measure a surface shape in which high measurement accuracy is continuously continued.

In the measurement apparatus 100 as described above, the optical path lengths of the light beams B ₁ and B ₅ used for measurement are short. Thereby, it is difficult to be affected by temperature change of the measurement environment, fluctuation of atmosphere, etc., and improvement and stability of measurement accuracy can be obtained.

  In the measurement apparatus 100 described above, the rotating autocollimator 124 may be disposed so that the optical axis of the autocollimator 124 and the rotation axis of the rotary table 140 intersect. This facilitates calculation when calculating the overall shape of the sample 160. However, even if the optical axis of the autocollimator 124 and the rotation axis of the rotary table 140 do not intersect, the accurate shape of the sample 160 can be calculated if the amount of deviation between the two is known. In other words, if the measurement of the deviation amount is wrong, an error occurs in the measurement result.

  FIG. 10 is a schematic plan view showing another structure of the measuring apparatus 100. FIG. 11 is a side view of the measuring apparatus 100 shown in FIG. 10 as viewed from the Y direction in the figure. 10 and FIG. 11, the same reference numerals are assigned to the same elements as those of the other measurement apparatuses 100 and redundant description is omitted.

  The measuring apparatus 100 includes a pair of guide rails 182 on the upper end surface of the support column that stands up from the surface plate 116. The guide rail 182 is orthogonal to the paper surface in FIG. 11 and extends in the Y direction shown in FIG. The guide rail 182 engages with both ends of the moving guide rail 184 extending in the X direction. Accordingly, the moving guide rail 184 moves along the guide rail 182 in the Y direction orthogonal to the paper surface in FIG.

In addition, the autocollimator 120 is supported on the upper end of one of the columns 114 in parallel with the guide rail 182. The autocollimator 120 emits the light beam B ₁ toward the side surface of the moving guide rail 184 in parallel with the guide rail 182.

The side surfaces of the moving guide rail 184, the introduction mirror 186 for changing the propagation direction of the light beams B ₁ on a horizontal plane is disposed. By being reflected by the introduction mirror 186, the light beam B ₁ propagates in the longitudinal direction of the moving guide rail 184 in parallel with the moving guide rail 184 regardless of the position of the moving guide rail 184 on the guide rail 182. .

  A translation table 130 and a rotary table 140 mounted on the translation table 130 are disposed on the side surface of the movement guide rail 184. A fixed mirror 154 is mounted on the translation table 130, and a rotary mirror 152 is mounted on the rotary table 140.

The translation table 130 is driven by a drive unit (not shown) and translates horizontally along the movement guide rail 184. The fixed mirror 154 translates with the translation table 130. The fixed mirror 154 receives the light beam B ₁ reflected by the introduction mirror 186 and reflects it toward the rotary mirror 152 regardless of the position of the translation table 130.

The rotating mirror 152 can change the projection angle of the light beam B ₁ received from the fixed mirror 154. When changing the projection angle of the light beam _{B 1,} the projection position _{P 1} of the light beams _{B 1} to the sample 160 on the platen 116 is also changed. Therefore, the projection position P ₁ of the light beam B ₁ with respect to the sample 160 can be changed by appropriately rotating the rotary mirror 152.

When the translation table 130 is translated with the rotary table 140 fixed, the light beam B ₁ can be translated while maintaining the irradiation angle of the light beam B ₁ with respect to the sample 160. Thereby, the irradiation position P ₁ can be moved while maintaining the irradiation angle of the light beam B ₁ with respect to the sample 160.

  Therefore, when the moving guide rail 184 is stopped, the surface shape of the sample 160 cut by one plane parallel to the moving guide rail 184 is considered by considering the moving guide rail 184 as the guide rail 112 in FIG. Can be measured in the same manner as the measuring apparatus 100 shown in FIG.

  Furthermore, by moving the moving guide rail 184, the surface shape of the sample 160 when cut by another surface can be measured. Therefore, the two-dimensional shape of the surface of the sample 160 can be measured by repeatedly moving the moving guide rail 184.

  In addition, by making the sample stage 190 that supports the sample 160 on the surface plate 116 rotatable, the shape of the sample 160 having a rotating body shape like a lens can be efficiently measured.

  In any of the above embodiments, the sample 160 is placed on the horizontal surface plate 116 or the sample stage 190, and the shape of the upper surface thereof is measured. However, the direction of the light beam at the time of measurement is not limited to this. Further, in measurement of the surface shape of the optical element, the surface shape of the mounted optical element may be measured in consideration of the influence of gravity on the shape of the sample. In such a case, so to speak, the measuring device 100 is attached to the sample 160 and the shape is measured.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

  The order of execution of each process such as operations, procedures, steps, and stages in the apparatus, system, program, and method shown in the claims, the description, and the drawings is particularly “before” or “prior to”. It should be noted that the output of the previous process may be realized in any order unless used in a subsequent process. Regarding the operation flow in the claims, the description, and the drawings, even if it is described using “first”, “next”, etc. for convenience, it means that it is essential to carry out in this order. It is not a thing.

DESCRIPTION OF SYMBOLS 100 Measuring apparatus, 110 Frame, 112, 182 Guide rail, 114 support | pillar, 116 Surface plate, 118 Control part, 120, 122, 124 Autocollimator, 130 Translation table, 140 Rotary table, 150 Optical system, 152 Rotary mirror, 154 156 Fixed mirror, 160 samples, 170 Differential laser length measuring machine, 172, 174 Laser length measuring machine, 184 Moving guide rail, 186 Introduction mirror, 190 Sample stand

Claims (9)

A projection unit that projects a light beam toward a target surface;
A specifying unit that receives the light beam reflected by the target surface and specifies a local shape by a local inclination of the target surface;
A translation unit that translates the light beam while maintaining a projection angle of the light beam;
A calculation unit that accumulates the local shapes sequentially specified by the specifying unit in accordance with the translation of the light beam, and calculates a continuous shape of the target surface;
A changing unit for changing a projection angle of the light beam;
When the changing unit changes the projection angle from the first angle to the second angle, the specifying unit causes the light beam to be projected at the projection position on the target surface by the first angle at the second angle. And a control unit for re-specifying the local shape at the projection position, and measuring the shape of the target surface.   The measuring device according to claim 1, wherein the changing unit changes the projection angle to a range in which the light beam reflected by the target surface is received by the specifying unit.   The measuring apparatus according to claim 1, wherein the changing unit changes the projection angle so that a reflection angle of the light beam by the target surface becomes smaller. The measuring device according to claim 1 , wherein the calculation unit calculates the continuous shape by integrating the accumulated local shape. The changing unit is
A fixed mirror that reflects the generated light beam;
The fixed mirror is further reflected light beam reflected projected on the target surface, and any one of claims 1 and a movable mirror for changing the projection angle swings to claim 4 measuring device according to. The changing unit is
An autocollimator that projects a light beam toward the target surface;
The measurement apparatus according to claim 1, further comprising: a turntable that rotates while supporting the autocollimator. The control unit, the distance to the target surface in the case of specifying the local shape the first angle and the first angle, one of the claims 1 to identify the projection position to Claim 6 1 The measuring device according to item . The measurement device according to claim 1 , wherein the control unit includes a display unit that projects a marker beam onto the target surface and displays a projection position based on the first angle. A projection stage for projecting a light beam toward the target surface;
A specific step of receiving the light beam reflected by the target surface and specifying a local shape by a local inclination of the target surface;
An accumulation step of sequentially accumulating the local shapes by translating the light beam while maintaining a projection angle of the light beam;
A calculation step of calculating a continuous shape of the target surface from the accumulated local shape;
A change step of changing a projection angle of the light beam reflected by the target surface;
When the projection angle is changed from the first angle to the second angle, the light beam is projected by the second angle to the projection position on the target surface by the first angle, and the local shape at the projection position is changed. A re-specifying step for re-specifying, and measuring a shape of the target surface.

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