JP6821407B2 - Measuring method, measuring device, manufacturing method of optical equipment and manufacturing equipment of optical equipment - Google Patents

Description

The present invention relates to a measuring method, a measuring device, a manufacturing method of an optical device, and a manufacturing device of an optical device.

Conventionally, a method has been proposed in which the reflected light from the test surface irradiated with light is measured by a Shack-Hartmann sensor, and the surface shape of the test surface is measured in a non-contact and high-speed manner using the output from the sensor. (See Non-Patent Document 1). This measuring method can measure the shape of the surface to be inspected with various design values as compared with an interferometer using a null lens (see Patent Document 1). In addition, compared to a stitching interferometer (see Patent Document 2) and a scanning interferometer (see Patent Document 3) that move a sample during measurement, a stage and a length measuring machine that move the sample with higher accuracy, and a complicated analysis program. Is unnecessary.

In the measurement method disclosed in Non-Patent Document 1, when the test surface is an aspherical surface, the incident light is not irradiated perpendicularly to the test surface, and the ray angle of the reflected light from the test surface is the incident light. It is different from the ray angle of. Therefore, the reflected light does not become parallel light at the light receiving portion of the sensor, and is detected as a wave surface that is greatly deviated from the plane wave surface. Therefore, even if the wave surface of the reflected light is measured by the light receiving portion of the sensor, the wave surface does not directly represent the shape of the surface to be inspected unlike the Fizeau interferometer.

In order to calculate the surface shape of the test surface from the measured wave surface, the position magnification (so-called distortion), which is the ratio of the abscissa of the sensor to the abscissa of the test surface, and the ray angle on the sensor surface and the test surface The angle magnification, which is the ratio of the ray angles at, is required.

However, the position magnification and the angle magnification are not constant with respect to the distance from the optical axis and have a distribution. Since these distributions change sensitively due to an error in the radius of curvature of the lens included in the optical system, an error in the position in the optical axis direction (so-called alignment error), spherical aberration, and the like, it is necessary to calibrate them. Patent Documents 4, 5, 6 and 7 disclose a method for calibrating the position magnification distribution.

Japanese Unexamined Patent Publication No. 09-329427 Japanese Unexamined Patent Publication No. 2004-125768 Japanese Patent No. 3971747 Japanese Unexamined Patent Publication No. 2000-97663 Japanese Unexamined Patent Publication No. 10-281736 Japanese Unexamined Patent Publication No. 2006-133509 JP-A-2009-180554 Japanese Unexamined Patent Publication No. 2012-132682

Jahannes Pfund, Norbert Lindlein and Johannes Schwider, "NonNull Testing of rotational symmetry assessment: a systematic error." Opt. 40 (2001) p. 439

In the calibration method disclosed in Patent Documents 4, 5 and 6, the position magnification distribution is calibrated by moving the test surface by a known amount and detecting the amount of change in the measured value measured by the light receiving portion of the sensor. .. Therefore, a stage for moving with high accuracy and a measuring machine for measuring the moving distance with high accuracy are required, and it is difficult to calibrate the position magnification and the angle magnification with high accuracy at the same time.

Further, in the calibration method disclosed in Patent Document 7, a part of the members of the optical system is moved to calibrate the position magnification distribution. However, since calibration is performed using the size of the diameter of the interference fringes on the light receiving surface as an index, when the surface to be inspected is an aspherical surface, the pitch of the interference fringes becomes too fine and the diameter of the interference fringes cannot be accurately grasped. .. Furthermore, it is difficult to calibrate the angular magnification distribution with high accuracy.

Further, in the method disclosed in Patent Document 8, the shape is calculated by measuring the difference between the test surfaces using one aspherical surface having a known shape as a prototype. Here, when the optical system is in a state different from the design value due to assembly factors or environmental factors during measurement, the position magnification distribution and the angle magnification distribution are different from the calculated (designed) magnification distribution due to this error, and the accuracy is high. It is difficult to measure.

In view of such problems, it is an object of the present invention to provide a measuring method, a measuring device, a manufacturing method of an optical device, and a manufacturing device of an optical device capable of easily performing high-precision calibration.

The measurement method as one aspect of the present invention includes an optical system that guides the light reflected by the test surface to the sensor, and a control unit that measures the shape of the test surface based on the output from the sensor. It is a measurement method using an apparatus, and a first wave surface corresponding to each prototype from the sensor that receives light reflected by the first prototype and the second prototype having different aspherical shapes. And, assuming that the optical system is arranged based on the design information, the sensor acquires from each light reflected by each prototype based on the design information of the optical system. At least the design information of the optical system is changed so that the difference between the calculation step for calculating the second wave surface corresponding to each prototype and the first and second wave surfaces corresponding to each prototype is smaller than a predetermined value. It is characterized by having a change step to be performed.

Further, the measurement method as another aspect of the present invention includes an optical system that guides the light reflected by the test surface to the sensor, a control unit that measures the shape of the test surface based on the output from the sensor, and a control unit. It is a measurement method using a measuring device having the above, and corresponds to each prototype from the sensor that receives the respective light reflected by the first prototype and the second prototype having different aspherical shapes. Assuming that the acquisition step of acquiring the wave surface of 1 and the optical system are arranged based on the design information, the sensor is obtained from each light reflected by each prototype based on the design information of the optical system. Based on the calculation step of calculating the second wave surface corresponding to each prototype acquired by, and the first and second wave surfaces, at least a part of the members of the optical system, the first or second source. It is characterized by having at least a change step of changing the design information of the optical system so that the difference in the optical arrangement corresponding to each prototype of the device and at least two members of the sensor is small. To do.

Further, the measurement method as another aspect of the present invention includes an optical system that irradiates the test optical system with light emitted from the light source and guides the light transmitted through the test optical system to the sensor, and the sensor. A measurement method using a measuring device having a control unit for measuring the transmitted wave surface of the optical system to be inspected based on an output, and a first reference optical system and a second reference optical system having different characteristics from each other. Assuming that the acquisition step of acquiring the first wave surface corresponding to each reference optical system from the sensor that receives each light transmitted through the optical system and the optical system are arranged based on the design information, the optical Based on the system design information, a calculation step for calculating a second wave surface corresponding to each prototype acquired by the sensor from each light transmitted through each reference optical system, and a first calculation step corresponding to each reference optical system. It is characterized by having at least a change step of changing the design information of the optical system so that the difference between the second wave fronts becomes smaller than a predetermined value.

Further, the measurement method as another aspect of the present invention includes an optical system that irradiates the test optical system with light emitted from the light source and guides the light transmitted through the test optical system to the sensor, and the sensor. A measurement method using a measuring device having a control unit for measuring the transmitted wave surface of the optical system to be inspected based on an output, and a first reference optical system and a second reference optical system having different characteristics from each other. Assuming that the acquisition step of acquiring the first wave surface corresponding to each reference optical system from the sensor that receives each light transmitted through the optical system and the optical system are arranged based on the design information, the optical Based on the system design information, a calculation step of calculating a second wave plane corresponding to each reference optical system acquired by the sensor from each light transmitted through each reference optical system, and the first and second wave planes. The difference in optical arrangement corresponding to each reference optical system of at least a part of the members of the optical system, the first or second reference optical system, and at least two members of the sensor is small. As such, it is characterized by having at least a change step of changing the design information of the optical system.

According to the present invention, it is possible to provide a measuring method, a measuring device, a manufacturing method of an optical device, and a manufacturing device of an optical device capable of easily performing high-precision calibration.

It is a schematic block diagram of the measuring apparatus which executes the measuring method of Example 1. FIG. It is a block diagram of a sensor. It is a flowchart which shows the measurement method of Example 1. FIG. It is a flowchart which shows the pre-processing of Example 1. FIG. It is a flowchart which shows the calibration process of Example 1. FIG. It is a flowchart which shows the measurement process of Example 1. FIG. It is a flowchart which shows the analysis process of Example 1. FIG. It is a flowchart which shows the measurement method of Example 3. FIG. It is a flowchart which shows the calibration process at the time of measurement of Example 3. FIG. It is a flowchart which shows another calibration process at the time of measurement of Example 3. FIG. It is a flowchart which shows the pre-processing of Example 4. It is a figure for demonstrating the position and angle of a light ray. It is a flowchart which shows the calibration process of Example 4. It is a flowchart which shows the analysis process of Example 4. It is a flowchart which shows the measurement method of Example 5. It is a block diagram of the manufacturing apparatus of the optical apparatus of Example 6.

Hereinafter, examples of the present invention will be described in detail with reference to the drawings. In each figure, the same member is given the same reference number, and duplicate description is omitted.

FIG. 1A is a schematic configuration diagram of a measuring device 100 capable of executing the measuring method of this embodiment. The light source 1 is a laser light source or a laser diode that emits a monochromatic laser beam. The light emitted from the light source 1 is focused toward the pinhole 3 by the condenser lens 2. The pinhole 3 generates a spherical wave with small aberration. A single mode fiber may be used instead of the pinhole 3. The spherical wave from the pinhole 3 is reflected by the half mirror 4 and converted into convergent light by the projection lens 5. The focused light is reflected by the prototype surfaces 61a and 62a of the two prototypes 61 and 62 or the test surface 7a of the test object 7, and is transmitted through the light projecting lens 5, the half mirror 4 and the imaging lens 9. Then it enters the sensor 11. The projectile lens 5, the half mirror 4, and the imaging lens 9 constitute an optical system that guides the light reflected by each prototype surface or the surface to be inspected 7a to the sensor 11. The analysis calculation unit (control unit) 13 is composed of a computer and functions as a wave surface measurement unit, a wave surface calculation unit, a calibration unit, and a shape calculation unit.

In this embodiment, the optical system is calibrated using prototypes (first prototype, second prototype) 61 and 62 having different aspherical shapes. Both the prototype 61 and 62 are manufactured with different design values from the test object 7. The prototype surfaces 61a and 62a of the prototypes 61 and 62 are accurately measured by a device different from the measuring device 100, for example, a probe type measuring device, and the analysis calculation unit 13 saves the measured surface shape data. To do.

The floodlight lens 5 and the imaging lens 9 are each composed of a plurality of lens elements. The focal length, radius of curvature and radius of the projecting lens 5 and the imaging lens 9 and the magnification of the optical system combining the projecting lens 5 and the imaging lens 9 are the diameter (effective diameter) of the surface to be inspected 7a and the radius of curvature. And it is determined based on the size of the light receiving portion of the sensor 11.

The test object 7 is preferably arranged at a position where the test surface 7a and the sensor conjugate surface coincide with each other on the optical axis. In this case, since the light reflected by the surface to be inspected 7a does not overlap on the sensor 11, the sensor 11 can accurately measure the angular distribution of the light rays.

As shown in FIG. 2A, the sensor 11 is composed of a microlens array 21 in which a large number of microcondensing lenses are arranged in a matrix and an image sensor 22 such as a CCD, and is generally a shack.・ It is called a Hartmann sensor. In the sensor 11, the light beam (luminous flux) transmitted through the microlens array 21 is condensed on the image sensor 22 for each minute condensing lens. The image sensor 22 photoelectrically converts an optical image formed by light rays from a minute condensing lens and outputs an electric signal. The angle φ of the light beam incident on the image sensor 22 detects the difference Δp between the position of the spot focused by the minute condensing lens and the position calibrated in advance, for example, the spot position when parallel light is incident. It is required by that. The angle φ of the light beam is expressed by the following equation (1), where f is the distance between the microlens array 21 and the image sensor 22.

φ = atan (Δp / f) (1)
By performing the above processing on all the minute condensing lenses, the angular distribution of the light rays incident on the sensor 11 can be calculated using the output from the sensor 11.

The sensor 11 is not limited to the Shack-Hartmann sensor as long as it can measure the angular distribution of the wave surface or the light beam. For example, as the sensor 11, a shearing interferometer or a Talbot interferometer composed of a Hartmann plate, a diffraction grating 23 shown in FIG. 2B, and an image pickup device 24 may be used.

Further, when the size (diameter) of the light ray received by the sensor 11 is larger than the light receiving area of the sensor 11, the sensor 11 is moved within the light receiving surface (xy surface) to calculate the angular distribution of the light ray, and the calculated data. May be joined together to create the overall ray angle distribution.

Hereinafter, a method of measuring the surface shape of the surface to be inspected 7a, which is the aspherical shape of the present embodiment, will be described with reference to the flowchart of FIG. The measurement method of this embodiment is executed by the analysis calculation unit 13 according to a processing program as a computer program. The processing program may be recorded on a computer-readable recording medium, for example.

In step S10, the analysis calculation unit 13 executes the preprocessing. FIG. 4 is a flowchart showing preprocessing.

In step S101, the analysis calculation unit 13 uses a measuring device different from the measuring device 100 that can measure the shape with high accuracy, for example, the prototype surfaces 61a and 62a measured by the stylus type measuring device. Acquires shape (aspherical shape) data and saves it.

In step S102, the analysis calculation unit 13 uses the surface shapes of the prototype surfaces 61a and 62a measured in step S101 and the design information of the optical system of the measuring device 100 to obtain each wave surface (each wave surface) acquired from the sensor 11. Calculation wave surface, second wave surface) Wcal1 and Wcal2 are calculated. That is, the analysis calculation unit 13 assumes that the optical system of the measuring device 100 is arranged based on the design information, and the sensor 11 is based on the surface shapes of the prototype surfaces 61a and 62a measured in step S101. Calculate each wave surface obtained from. The design information of the optical system may include not only the optical arrangement but also the aberration and assembly error of the optical system measured in advance, the surface shape and homogeneity information of the lens, the refractive index distribution information, and the like. The wave plane can be represented by, for example, the Zernike function, which is an orthogonal function.

In step S103, the analysis calculation unit 13 calculates the sensitivity required for calibration. Specifically, the analysis calculation unit 13 calculates the wave surface acquired by the sensor surface when the surface shape of each prototype surface is changed by a small amount from the design information, and this wave surface and the wave surface are calculated in step S102. The sensitivity to the surface shape is calculated using the difference from the wave surface. Similarly, the sensitivity to the arrangement in the optical axis direction is calculated by changing the positions of each prototype surface and the imaging lens 9 in the optical axis direction (z-axis direction) by a small amount from the design information. In addition to the surface shape and arrangement in the optical axis direction, even if the sensitivity corresponding to changes in the surface spacing, radius of curvature, various aberrations, phase distribution, refractive index distribution, homogeneity, and birefringence distribution in the lens is calculated. Good. The sensitivity can be expressed by, for example, a Zernike function which is an orthogonal function. Further, in this embodiment, the wave surface is calculated, but the wave surface may be acquired by moving each prototype, the imaging lens 9, and the sensor 11 by the stage and measuring with the sensor 11. In this case, it should be noted that the stage error is included when calculating the sensitivity.

In step S11, the analysis calculation unit 13 executes the calibration process. It is difficult to manufacture the optical system according to the design information due to lens processing error, alignment error, holding deformation, and the like. Therefore, in this embodiment, in order to accurately grasp the state of the optical system and measure the surface shape with high accuracy, the calibration process is performed according to the flow of FIG. FIG. 5 is a flowchart showing a calibration process.

In step S111, the analysis calculation unit 13 causes the sensor 11 to measure the wave surface (measurement wave surface) Wg1 of the light reflected by the prototype surface 61a in a state where the prototype 61 is installed in the measuring device 100.

In step S112, the analysis calculation unit 13 causes the sensor 11 to measure the wave surface (measurement wave surface) Wg2 of the light reflected by the prototype surface 62a while the prototype 62 is installed in the measuring device 100.

In this embodiment, the measured wave surfaces Wg1 and Wg2 measured in steps S111 and S112 are set as the first wave surface. The analysis calculation unit 13 has a plane (xy plane) orthogonal to the optical axis of each prototype surface so that the difference between the tilt component and the coma component between the measurement wave plane and the calculated wave plane is sufficiently small in the adjustment movement mechanism (not shown). ) And the inclination with respect to the xy plane. This adjustment reduces the alignment error of each prototype. When measuring the test object 7a, the same alignment is performed.

In step S113, the analysis calculation unit 13 first calculates the difference ΔWg1 between the measured wave surface Wg1 and the calculated wave surface Wcal1 and the difference ΔWg2 between the measured wave surface Wg2 and the calculated wave surface Wcal2, as shown in the following equation (2). To do. Subsequently, the optical parameters of the optical system are calculated using the sensitivity so that the differences ΔWg1 and ΔWg2 are smaller than the predetermined values, respectively.

Here, a method of calculating the optical parameters of the optical system using the sensitivity calculated in the preprocessing will be specifically described. In this embodiment, the spherical components (Z4 and Z9) of the Zernike function are used, and the optical parameters are "the amount of error from the design information of the arrangement of the prototype and the lens on the optical axis" and "design of the surface shape". Calculate the amount of error from the information. The Z4 term component (secondary component) and the Z9 term component (fourth component) of the spherical components of the spherical components of ΔWg1 and ΔWg2, which are the differences between the measured wave surface and the calculated wave surface, are represented by the following equation (3).

Here, ΔWg1_Z4 and ΔWg1_Z9 are the Z4 term component and the Z9 term component of the spherical component of the difference ΔWg1. ΔWg2_Z4 and ΔWg2_Z9 are Z4 term components and Z9 term components of the spherical component of the difference ΔWg2. The S1 prototype _Z4 and the S1 prototype _Z9 are the sensitivities of the Z4 component and the Z9 component of the spherical component of the calculated wave surface when the prototype 61 is moved in the optical axis direction. The S2 prototype _Z4 and the S2 prototype _Z9 are the sensitivities of the Z4 component and the Z9 component of the spherical component of the calculated wave surface when the prototype 62 is moved in the optical axis direction. The S1 lens_Z4 and the S1 lens_Z9 are the sensitivities of the Z4 and Z9 components of the spherical component of the calculated wave surface when the imaging lens 9 is moved in the optical axis direction with the prototype 61 installed. .. The S2 lens_Z4 and S2 lens_Z9 are the sensitivities of the Z4 and Z9 components of the spherical component of the calculated wave surface when the imaging lens 9 is moved in the optical axis direction with the prototype 62 installed. .. The S1 surface shape 1_Z4 and the S1 surface shape 1_Z9 are sensitivities to the surface shape error of one lens (first lens) in the optical system in which the prototype 61 is installed. The S2 surface shape 1_Z4 and the S2 surface shape 1_Z9 are sensitivities to the surface shape error of the first lens in the state where the prototype 62 is installed. The S1 surface shape 2_Z4 and the S1 surface shape 2_Z9 are sensitivities to the surface shape error of another lens (second lens) in the optical system in which the prototype 61 is installed. The S2 surface shape 2_Z4 and the S2 surface shape 2_Z9 are sensitivities to the surface shape error of the second lens in the state where the prototype 62 is installed.

The analysis calculation unit 13 solves the equation (3) so that the differences ΔWg1 and ΔWg2 are smaller than the predetermined values, respectively. By doing so, the "error amount from the design information of the arrangement of the prototype / lens on the optical axis" (= the amount of change in the arrangement of the prototype / lens) and the "error amount from the design information of the surface shape" of the two surfaces "(= Surface shape change amount 1, 2) is calculated.

The amount of error from the calculated design information of the prototype and lens and the amount of error from the design information of the surface shape are not necessarily the same as the amount of error actually occurring in the optical system. However, it is possible to cancel the error generated by the interaction of a plurality of errors.

In this embodiment, the optical parameters were calculated using the Z4 and Z9 components of the spherical component of the difference between the measured wave surface and the calculated wave surface, but the difference between the measured wave surface and the calculated wave surface is smaller than the predetermined value. It is important to calculate the parameters, and the calculation method is not limited to this. For example, the optical parameters may be calculated so as to match (smaller than a predetermined amount) up to the higher-order wave surface difference in consideration of even higher-order spherical components. By using a lot of information, it is possible to calibrate with high accuracy.

Further, in this embodiment, as represented by the equation (3), the arrangement of the prototype and the sensor in the optical axis direction and the surface shape information of the two surfaces were obtained as optical parameters and calibrated. Calibration may be performed using the surface shape information of more surfaces. Further, the surface shape of one surface may be expressed by the Zernike function, and a higher-order spherical component may be used. In addition to each prototype and imaging lens 9, the arrangement of other optical elements in the optical system, surface spacing, radius of curvature, surface shape, aberration, phase distribution, refractive index distribution, homogeneity, birefringence distribution, and light reception Various optical parameters such as the amount of linearity measurement error of the sensor, the wavelength of the light source, and the amount of each change may be used. When calibrating using multiple optical parameters, it is desirable to choose ones with different sensitivities.

Further, instead of calculating the amount of error from the design information using the sensitivity based on the equation (3), ray tracing is performed and the optical parameters are calculated so that the two wave plane differences ΔWg1 and ΔWg2 are smaller than the predetermined amount. You may. In addition, a method of estimating the most plausible optical parameter from which the measured wave surface can be obtained by calculation may be used. There are no particular restrictions on the required optical parameters, such as the arrangement of optical elements in the optical system, surface spacing, radius of curvature, aberration, phase distribution, refractive index distribution, homogeneity, birefringence distribution, and the amount of linearity error of the measurement wave plane of the light receiving sensor. It may be the wavelength of the light source or the amount of each change. As shown in FIG. 1B, a method such as setting a dummy surface 14 to give an arbitrary phase distribution may be used.

Further, in this embodiment, the calibration using two prototypes has been described, but by using three or more prototypes, more accurate calibration can be performed. Further, the higher the frequency of the wave surface that matches the measured wave surface and the calculated wave surface and the number of parameters for calibrating the error of the optical system, the more accurate calibration can be realized, but at least it is expressed by the equation (4). So two are needed.

Further, when the difference between the aspherical shapes of the two prototypes is large, the sensitivity of the wave surface is different, the optical path passing through the optical system is different, and the wave surface that more reflects the error of the optical system can be obtained. Therefore, the difference between the central curvatures of the two prototypes is 0.001 (1 / mm) or more (more preferably 0.10 (1 / mm) or more, or 2.00 (1 / mm). ) The following) is preferable. Further, when the amount of aspherical surface, which is the amount of deviation from the spherical surface, is large, the sensitivity of the wave surface is different. Therefore, the amount of aspherical surface of each aspherical shape of the two prototypes is preferably 0.05 mm or more. Further, three or more prototypes satisfying the above conditions may be prepared, and two prototypes may be selected according to the design value of the surface to be inspected 7a at the time of calibration. At this time, it is preferable to select a prototype with a small shape difference from the surface to be inspected 7a.

The spherical component (rotational symmetry component) can be obtained as described above, but a rotation asymmetry component such as astigmatism remains on the calculated wave surface. In order to remove the rotation asymmetric component, the prototype or the test object may be rotated around the optical axis, and the design information of the optical system may be changed based on the output from the sensor 11 before and after the rotation. Further, the sensitivity to the rotational asymmetric component may be calculated in the same manner, and the above relational expressions in various Zernike functions may be calculated to obtain a solution in which the difference between the two wave planes is smaller than a predetermined value in all the components. If it is possible to find a solution in which the difference between the two wave surfaces is smaller than a predetermined value for all the components, it is possible to eliminate the trouble of rotating the prototype and the surface to be inspected, and to perform high-precision measurement at high speed.

In step S114, the analysis calculation unit 13 changes the design information of the optical system based on the optical parameters calculated in step S113. In the changed new design information, the error generated in processing or assembly is used as the design information of the optical system after calibration. The design information of the optical system after calibration is not necessarily the same as the error actually generated in the optical system, but the error generated by the interaction of a plurality of errors is canceled and the measurement wave plane acquired from the sensor 11 is calculated. Can be equal to the wave surface. That is, the optical system can be calibrated by the method of this embodiment.

In the calibration process of this embodiment, the optical parameters are calculated so that the difference between the measured wave surface and the calculated wave surface is smaller than a predetermined value, but the present invention is not limited to this. For example, the optical parameters may be calculated so that the optical arrangements of the two prototypes are equal. In this case, the optical axis direction optics corresponding to each prototype when the two prototypes are installed, at least a part of the optical system, and at least two members of the sensor 11. The optical parameters may be calculated so that the difference in arrangement (driving amount) becomes small.

Further, in the calibration process of this embodiment, the design information of the optical system is changed based on the calculated optical parameters, but each member may be actually driven by the stage by the calculated drive amount.

In step S12, the analysis calculation unit 13 executes the measurement process. FIG. 6 is a flowchart showing the measurement process.

In step S121, the analysis calculation unit 13 causes the sensor 11 to measure the reflected light from the test surface 7a with the test object 7 installed in the measuring device 100. The analysis calculation unit 13 causes an adjustment movement mechanism (not shown) to adjust the position and inclination of the test object 7 so that the difference between the tilt component and the coma component between the measurement wave surface and the calculated wave surface is sufficiently small. Regarding the position in the optical axis direction, the center positions of the prototype surface 61a (62a) and the test surface 7a are separately measured by an external measuring instrument such as a length measuring device or a displacement meter, and the prototype surface 61a (62a) is measured. The position of the surface to be inspected 7a may be adjusted so as to coincide with the position of. In this embodiment, since the Shack-Hartmann sensor is used as the sensor 11, the light distribution angle Vs of the reflected light can be measured. The analysis calculation unit 13 stores the measured ray distribution angle Vs.

In step S13, the analysis calculation unit 13 executes an analysis process based on the wave surface information of the test surface 7a measured by the sensor 11 in order to calculate the shape information of the test surface 7a. FIG. 7 is a flowchart showing the analysis process.

In step S131, the analysis calculation unit 13 traces the ray using the design information of the optical system changed in the calibration process, and from the ray position distribution and the ray angle distribution Vs to be held, the ray position on the surface to be inspected 7a is obtained. Find the ray angle distribution vs. Although the shape of the test surface 7a is unknown, ray tracing may be performed based on the design shape of the test surface 7a.

In step S132, the analysis calculation unit 13 calculates the shape of the surface to be inspected 7a by integration from the ray position and the ray angle distribution vs. obtained in step S131.

As described above, in order to perform ray tracing and convert the information on the sensor 11 into the information on the surface to be inspected 7a, it is necessary to incorporate the ray tracing software in the measuring device 100. However, ray tracing enables high-speed and highly accurate measurement. In addition, the influence of the rotation asymmetric component can be considered.

As described above, by using the measurement method of this embodiment using at least two prototypes having different aspherical shapes, calibration can be easily performed even if the optical system differs from the design value depending on the assembly and environment. Can be done. As a result, the shape of the surface to be inspected 7a can be measured at high speed and with high accuracy without contact.

In this embodiment, the test sample is a lens, but the sample is not limited to a lens, and may be a lens having the same shape as the lens, for example, a mold. Further, in this embodiment, the case where the test surface 7a is a convex aspherical surface has been described, but it may be a concave aspherical surface. Even in this case, as shown in FIG. 1 (c), at least two prototypes 61 and 62 may be used for calibration. The two prototypes 61 and 62 preferably have different concave aspherical shapes.

In the first embodiment, in the calibration process, “the amount of error from the design information of the arrangement of the prototype / lens on the optical axis” and “the amount of error from the design information of the surface shape” were calculated at the same time. In this embodiment, the former is calculated and then the latter is calculated. By doing so, it is possible to obtain highly accurate calibration results with little variation. Since other configurations and processes are the same as those in the first embodiment, detailed description thereof will be omitted.

In this embodiment, paying attention to the spherical components (Z4, 9, 16, 25, 36 ...) of the Zernike function, the sensitivity is set so that the differences ΔWg1 and ΔWg2 between the measured wave surface and the calculated wave surface are smaller than the predetermined values. Use to calculate the optical parameters of the optical system. In this embodiment, "values of at least two parameters having a large error in the optical system or spatially changing wave planes of low-order frequencies" and "small errors in the optical system or spatially high-order frequencies". "Values of at least two parameters whose wave surface changes" are calculated. In this embodiment, the former is calculated and then the latter is calculated. By doing so, it is possible to obtain highly accurate calibration results with little variation. Hereinafter, the former will be described as "the amount of error from the design information of the arrangement of the prototype / lens on the optical axis", and the latter will be described as "the amount of error from the design information of the surface shape". The parameters that have a large error in the optical system or that the wave surface of the low-order frequency changes spatially are the arrangement of the optical elements of the optical system, the surface spacing, the radius of curvature, the amount of linearity measurement error of the light receiving sensor, and the light source. The wavelength. In the optical system, the parameters that have a small error or spatially change the wave surface of higher frequency are the surface shape, aberration, phase distribution, refractive index distribution, homogeneity, and birefringence distribution.

In this embodiment, the "error amount from the design information of the arrangement of the prototype / lens on the optical axis" is the three driving amounts of the imaging lens 9, each prototype, and the sensor 11. Further, the "error amount from the surface shape design information" is the surface shape error amount of three lens surfaces of the projection lens 5 and the imaging lens 9 each composed of a plurality of lenses.

In this embodiment, the analysis calculation unit 13 first calculates "the amount of error from the design information of the arrangement of the prototype / lens on the optical axis". The Zi ^ 2 term component (i is an integer of 2 to 6) of the spherical component of the difference ΔWg1 and ΔWg2 between the measured wave surface and the calculated wave surface is represented by the following equation (5).

Here, ΔWgi ^ 2_1 and ΔWgi ^ 2_2 (i is an integer of 2 to 6) are Zi ^ 2 term components of the spherical components of the difference ΔWg1 and the difference ΔWg2, respectively. S_i ^ 2_1_lens and S_i ^ 2_2_lens (i is an integer of 2 to 6) are the spherical components of the wave surface calculated when the imaging lens 9 is moved in the optical axis direction with the prototypes 61 and 62 installed, respectively. It is the sensitivity of the Zi ^ binary component (i is an integer of 2 to 6). S_i ^ 2_1_smp and S_i ^ 2_2_smp (i is an integer of 2 to 6) are the Zi ^ 2 term components (i is 2 to 2) of the spherical component of the calculated wave surface when the prototypes 61 and 62 are moved in the optical axis direction, respectively. Sensitivity (an integer of 6). S_i ^ 2_1_sns and S_i ^ 2_2_sns (i is an integer of 2 to 6) are the calculated spherical components of the wave surface when the sensor 11 is moved in the optical axis direction with the prototypes 61 and 62 installed, respectively. The sensitivity of the binomial component (i is an integer of 2 to 6). Mlens, Msmp, and Msns are the movement amounts of the imaging lens 9, the prototype 61 or the prototype 62, and the sensor 11, respectively.

Equation (5) cannot be solved because there are 10 equations for 3 variables of the amount of movement, but the least squares method or SVD (singular value decomposition) method is used to determine the amount of movement that minimizes the difference between the left and right sides. It may be obtained by using.

Next, the analysis calculation unit 13 calculates "the amount of error from the design information of the surface shape". The Zi ^ binary component (i is an integer of 2 to 6) of the spherical component, which is the value obtained by subtracting the product of the calculated movement amount and the sensitivity from the differences ΔWg1 and ΔWg2, is represented by the following equation (6). ..

Here, Di ^ 2_1 and Di ^ 2_2 (i is an integer of 2 to 6) are the Zi ^ 2 terms of the spherical component of the value obtained by subtracting the product of the calculated movement amount and the sensitivity from the differences ΔWg1 and ΔWg2, respectively. The component (i is an integer of 2 to 6). Si ^ 2_1_t_k and Si ^ 2_2_t_k are sensitivities to the surface shape error of the lens surface in the state where the prototypes 61 and 62 are installed, respectively. k represents three lens surfaces used among the projection lens 5 and the imaging lens 9, and is an integer of 1 to 3. t represents the variable of the number of the Zernike function when the surface shape error is added to each lens surface, and is 9 or 16. Gt_k is a coefficient of the Zt term of the lens surface specified by k.

Similar to the equation (5), the surface shape error that minimizes the difference between the left side and the right side may be obtained by using the least squares method or the SVD (singular value decomposition) method.

The amount of error from the calculated design information of the prototype and lens and the amount of error from the design information of the surface shape are not necessarily the same as the amount of error actually occurring in the optical system. However, it is possible to cancel the error generated by the interaction of a plurality of errors.

In this embodiment, the optical parameters were calculated using the components of the spherical component of the difference between the measured wave surface and the calculated wave surface up to the Z36 term, but the optical parameters were set so that the difference between the measured wave surface and the calculated wave surface was smaller than the predetermined value. It is important to calculate, and the calculation method is not limited to this. For example, the optical parameters may be calculated so as to match up to the higher-order wave surface difference (smaller than a predetermined amount) in consideration of even higher-order spherical components. By using a lot of information, it is possible to calibrate with high accuracy.

Further, in the equation (5), the amount of movement of each prototype, the imaging lens 9, and the sensor 11 in the optical axis direction is calculated, but other parameters with large errors such as the linearity measurement error of the sensor 11 and the light source 1 are calculated. The wavelength error may be calculated at the same time.

Further, in this embodiment, the three movement amounts and the surface shapes of the three surfaces are obtained and calibrated as optical parameters, but calibration may be performed using more than three surface shapes. Further, one surface shape may be expressed by a Zernike function, and a higher-order spherical component may be used. In addition, various optical parameters such as arrangement of other optical elements, surface spacing, radius of curvature, aberration, phase distribution, refractive index distribution, homogeneity, and birefringence distribution may be used. When calibrating using multiple optical parameters, it is desirable to select those with different sensitivities. Further, when the difference between the aspherical shapes of the two prototypes is large, the sensitivity of the wave surface is different, the optical path passing through the optical system is different, and the wave surface that more reflects the error of the optical system can be obtained. Therefore, the difference between the central curvatures of the two prototypes is preferably 0.001 (1 / mm) or more. Further, when the amount of aspherical surface, which is the amount of deviation from the spherical surface, is large, the sensitivity of the wave surface is different. Therefore, the amount of aspherical surface of each aspherical shape of the two prototypes is preferably 0.05 mm or more. Further, three or more prototypes satisfying the above conditions may be prepared, and two prototypes may be selected according to the design value of the surface to be inspected 7a at the time of calibration. At this time, it is preferable to select a prototype with a small shape difference from the surface to be inspected 7a.

In this embodiment, the calibration process is divided into an initial calibration process (assembly calibration process) and a measurement calibration process. Since the configuration and processing other than the calibration processing are the same as those in the first embodiment, detailed description thereof will be omitted.

Hereinafter, the measurement method of this embodiment will be described with reference to the flowchart of FIG. The measurement method of this embodiment is executed by the analysis calculation unit 13 according to a processing program as a computer program. The processing program may be recorded on a computer-readable recording medium, for example.

As described in the first embodiment, the optical system of the measuring device 100 is not arranged according to the design value due to environmental factors such as lens processing error, assembly error, alignment error of the test object, and temperature change. Therefore, high-precision measurement is possible by performing calibration to accurately grasp the state of the optical system.

In this embodiment, the initial calibration process and the calibration process at the time of measurement are executed as the calibration process. In the initial calibration process, error factors such as lens processing error and assembly error that do not change once calibrated and error factors that change over a long period of time are calibrated. In this process, as in Example 1, calibration is performed using two prototypes having different known aspherical shapes along the flow of FIG. In the calibration process during measurement, error factors that change (in a short time) for each measurement, such as optical system errors due to temperature changes caused by the environment and members in the device, are calibrated. In this process, calibration is performed using one prototype with a known aspherical shape. In this embodiment, more accurate measurement is possible by properly using the two calibration processes according to the cause of the error and the time axis of the change.

FIG. 9 is a flowchart showing the calibration process at the time of measurement. In order to calculate complicated information such as surface shape and phase distribution, information on at least two or more prototypes is required as in the initial calibration process. However, when correcting an error in the driving amount in the optical axis direction such as a temperature change, it is possible to calibrate with only the information of one prototype. In this process, one of the two prototypes used in the initial calibration process may be used as the prototype. In this embodiment, the prototype 61 is used as the prototype.

In step S201, the analysis calculation unit 13 causes the sensor 11 to measure the reflected light from the prototype 61 in a state where the prototype 61 is installed in the measuring device 100 in order to acquire the measurement wave surface.

In step S202, the analysis calculation unit 13 calculates the wave surface (calculated wave surface) of the reflected light from the prototype 61 on the sensor surface based on the design information of the optical system changed in the initial calibration process. The analysis calculation unit 13 calculates the optical parameters again so that the measured wave surface acquired in step S201 and the calculated wave surface match (the difference between the wave surfaces becomes smaller than a predetermined value). Since the purpose of the calibration process during measurement is to reduce the influence of error factors that change in a short time, it is preferable to select optical parameters that change in a short time. For example, in order to calibrate the temperature change in a short time, the focus component, the surface spacing, and the arrangement of the lens, the sensor, the test object, and the like may be selected.

In step S203, the analysis calculation unit 13 changes the design information of the optical system to the optical parameters calculated in step S202 again. Therefore, in the design information of the optical system after calibration, in addition to error factors that are difficult to change such as lens processing error and assembly error, error factors that occur during measurement are also taken into consideration.

FIG. 10 is a flowchart showing a measurement time calibration process different from the measurement time calibration process described with reference to FIG. 9. In this measurement calibration process, in order to reduce the influence of error factors that change in a short time, the prototype and the imaging lens are moved along the optical axis from the result of measuring one prototype. Similar to the measurement calibration process of FIG. 9, the prototype 61 is used as the prototype.

In step S211 the analysis calculation unit 13 causes the sensor 11 to measure the reflected light from the prototype 61 in a state where the prototype 61 is installed in the measuring device 100 in order to acquire the measurement wave surface.

In step S212, the analysis calculation unit 13 calculates the wave surface (calculated wave surface) of the reflected light from the prototype 62 on the sensor surface based on the design information of the optical system changed in the initial calibration process. Then, it is determined whether or not the difference between the measured wave surface and the calculated wave surface acquired in step S211 is smaller than a predetermined value. If it is larger than the predetermined value, the process proceeds to step S213, and if it is smaller than the predetermined value, the flow ends.

In step S213, the analysis calculation unit 13 uses the sensitivity calculated in step S103 of FIG. 4 to make the measured wave surface and the calculated wave surface coincide with each other (the difference between the wave surfaces becomes smaller than a predetermined value), and the prototype 61 and The driving amount of the imaging lens 9 is calculated.

In step S214, the analysis calculation unit 13 drives the prototype 61 and the imaging lens 9 based on the driving amount calculated in step S203.

In the measurement method of this embodiment, it is possible to correct the error generated at the time of measurement in real time, and more accurate measurement can be performed. Further, since the calibration process at the time of measurement can be realized by one prototype, the total measurement time can be shortened. In addition, usability can be improved and the calibration load can be reduced.

In Example 1, the method of calculating the ray angle distribution vs. the ray position on the surface to be inspected 7a from the ray angle distribution Vs and the ray position distribution measured by the sensor 11 has been described. In this embodiment, a method of calculating the light ray position and the light ray angle distribution vs on the test surface 7a will be described based on the table of the position magnification distribution and the angle magnification distribution. By using the magnification change table showing the relative relationship between the test surface 7a and the sensor surface, it is not necessary to mount the ray tracing software on the measuring device. The present embodiment differs from the first embodiment only in that the magnification distribution is calculated and the shape of the surface to be inspected is obtained from the measured wave surface.

FIG. 11 is a flowchart showing the preprocessing of this embodiment. Since the processes of steps S401, S402, and S404 are the same as the processes of steps S101 to S103 of FIG. 4 described in the first embodiment, detailed description thereof will be omitted.

In step S403, the analysis calculation unit 13 calculates the position magnification distribution α, the angle magnification distribution β, and the main ray angle distribution η between the sensor surface and the sensor conjugate surface. The position magnification distribution α and the angle magnification distribution β indicate the positional relationship and the angular relationship of the light rays reflected on the design value planes of the prototype surface and the test surface 7a between the sensor surface and the sensor conjugate surface, respectively.

Specifically, as shown in FIG. 12, the position magnification distribution α sets the distance from the optical axis to the incident position of the light beam on the sensor surface as r, and the distance from the optical axis to the incident position of the light ray on the sensor conjugate surface. When the distance is R, it is expressed by the following equation (7).

α = R / r (7)
The angular magnification distribution β is represented by the following equation (8). Here, when each prototype surface and the test surface 7a, which is the design value, are tilted by a small angle, the change in the light reflection angle on the meridional surface on the sensor conjugate surface is ΔV, and the change on the meridional surface on the sensor surface is Let Δv be the change in the ray incident angle.

β = Δv / ΔV (8)
The main ray angle distribution η performs a ray tracing calculation from the sensor 11 parallel to the optical axis (that is, at a ray angle of 0 ° with respect to the optical axis) using each prototype surface and the test surface 7a which is a design value. It is an angular distribution of light rays incident on each prototype surface and the surface to be inspected 7a when performed.

The position magnification distribution α, the angle magnification distribution β, and the main ray angle distribution η need to be calculated for each design value. In this embodiment, the design values of each prototype surface of the two prototypes and the surface to be inspected 7a are different, so it is necessary to obtain a distribution corresponding to each design value.

FIG. 13 is a flowchart showing the calibration process of this embodiment. Since the processes of steps S411 to S414 are the same as the processes of steps S111 to S114 of FIG. 5 described in the first embodiment, detailed description thereof will be omitted.

In step S415, the analysis calculation unit 13 calculates the magnification distribution using the method described in step S403 of FIG. 11 based on the changed optical parameters.

FIG. 14 is a flowchart showing the analysis process of this embodiment. Since the process of step S443 is the same process as step S132 of FIG. 7 described in the first embodiment, detailed description thereof will be omitted.

In step S441, the analysis calculation unit 13 calculates the ray angle distribution vs on the sensor conjugate surface from the ray angle distribution Vs measured by the sensor 11 using the following equation (9).

Subsequently, the analysis calculation unit 13 calculates the ray position distribution rs on the sensor conjugate surface using the following equation (10).

rs = αs × r (10)
Here, r is the light ray measurement position distribution of the sensor 11. In the Shack-Hartmann sensor, the ray measurement position distribution r corresponds to the center position of each microlens of the microlens array in coordinates on the image sensor. Further, the ray measurement position distribution r and the ray position distribution rs are distances from the optical axis represented by coordinates on the xy plane.

In step S442, the analysis calculation unit 13 performs a ray tracing calculation using the ray position distribution rs and the ray angle distribution vs, and obtains the intersection rbs of the test surface 7a with the design surface. The intersection rbs indicates the distance from the optical axis represented by the coordinates on the xy plane.

As described above, by performing the conversion using the magnification calibration distribution of this example, the shape of the test surface can be easily calculated without performing ray tracing.

In Examples 1 to 5, the case of measuring the reflected light of the test object has been described, but in this Example, the case of measuring the transmitted light of the single lens will be described. As the test object (test optical system), in addition to the single lens, a lens unit in which a plurality of lenses are combined, a liquid-immersed single lens, and a lens coated with matching oil can be measured in the same manner. FIG. 15 is a schematic configuration diagram of a measuring device (transmitted wave surface measuring device) 200 capable of executing the measuring method of this embodiment. By using the measuring device 200, the transmitted light of the single lens 70 can be measured.

In this embodiment, two lenses having different characteristics (for example, aspherical shape) are used as reference optical systems (prototypes) 610 and 620 for the calibration process. It is desirable that each reference optical system is known like a reflecting surface, but transmitted wave surface information cannot be known. Therefore, it is desirable to manufacture the reference optical system with high accuracy, and to measure the shape, curvature, internal transmittance, eccentricity, etc. in advance to reduce the uncertainty as much as possible.

Since other components and processes (pre-processing, calibration processing, measurement processing, analysis processing) are the same as those of the other embodiments, detailed description thereof will be omitted.

The manufacturing apparatus of the optical device of this embodiment will be described with reference to FIG. FIG. 16 is a schematic configuration diagram of an optical device manufacturing apparatus 300. The manufacturing apparatus 300 manufactures an optical device based on the information from the measuring apparatus 100 described in Examples 1 to 5.

In FIG. 16, 50 is a material (material) of the test lens, and 301 is a manufacturing unit that manufactures the test lens 51 as an optical element by performing processing such as cutting or polishing on the material 50. The lens 51 to be inspected has an aspherical shape.

The shape of the test lens (test surface) processed by the manufacturing unit 301 is measured by the measuring device 100 as the measuring unit using the measuring method described in the first embodiment. As described in the first embodiment, the measuring device 100 modifies the test surface based on the difference between the measurement data of the surface shape of the test surface and the target data in order to finish the test surface in the target surface shape. The amount of processing is calculated and output to the manufacturing unit 301. As a result, the manufacturing unit 301 performs correction processing on the test surface, and the test lens 51 having the test surface that reaches the target surface shape is completed.

When the test lens 51 is incorporated in an optical device such as a camera or an interchangeable lens and used, the manufacturing unit 301 may be configured to execute a step of incorporating the test lens into the optical device.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and modifications can be made within the scope of the gist thereof.

1 Light source 7a Subject surface 9 Imaging lens 11 Sensor 13 Analysis calculation unit (control unit)
61 First prototype 62 Second prototype 100 Measuring device

Claims (27)

A measurement method using a measuring device having an optical system that guides the light reflected by the surface to be inspected to a sensor and a control unit that measures the shape of the surface to be inspected based on the output from the sensor.
The acquisition step of acquiring the first wave surface corresponding to each prototype from the sensor that received the light reflected by the first prototype and the second prototype having different aspherical shapes.
Assuming that the optical system is arranged based on the design information, the number corresponding to each prototype acquired by the sensor from each light reflected by each prototype based on the design information of the optical system. Calculation step to calculate the wave surface of 2 and
A measurement method comprising: at least a change step of changing the design information of the optical system so that the difference between the first and second wave planes corresponding to each prototype is smaller than a predetermined value. The change step according to claim 1, wherein the change step includes a step of calculating at least two parameters so that the difference between the first and second wave surfaces corresponding to each prototype is smaller than the predetermined value. Measurement method. The above two parameters are the arrangement of optical elements of the optical system, surface spacing, radius of curvature, surface shape, aberration, phase distribution, refractive index distribution, homogeneity, birefringence distribution, amount of linearity measurement error of light receiving sensor, wavelength of light source, and The measurement method according to claim 2, wherein the amount of change is two of the respective amounts. The change step
A step of calculating a first parameter in which the wave surface of a low frequency changes so that the difference between the first and second wave surfaces corresponding to each prototype is smaller than the predetermined value, and
A step of calculating a second parameter in which the wave surface of a higher frequency changes based on the difference between the first and second wave surfaces corresponding to each prototype and the first parameter.
The measurement method according to claim 1, further comprising: at least a step of changing the design information of the optical system based on the first and second parameters. The first parameter is at least two of the arrangement of the optical elements of the optical system, the surface spacing, the radius of curvature, the amount of linearity measurement error of the light receiving sensor, and the wavelength of the light source.
The measurement method according to claim 4, wherein the second parameter is at least two of a surface shape, an aberration, a phase distribution, a refractive index distribution, a homogenity, and a birefringence distribution. A measurement method using a measuring device having an optical system that guides the light reflected by the surface to be inspected to a sensor and a control unit that measures the shape of the surface to be inspected based on the output from the sensor.
The acquisition step of acquiring the first wave surface corresponding to each prototype from the sensor that received the light reflected by the first prototype and the second prototype having different aspherical shapes.
Assuming that the optical system is arranged based on the design information, the number corresponding to each prototype acquired by the sensor from each light reflected by each prototype based on the design information of the optical system. Calculation step to calculate the wave surface of 2 and
Based on the first and second wave planes, it corresponds to each prototype of at least a portion of the optical system, the first or second prototype, and at least two of the sensors. A measurement method comprising, at least, a change step of changing the design information of the optical system so that the difference in optical arrangement becomes small. The measuring method according to any one of claims 1 to 6, wherein in the changing step, at least a part of the members of the optical system is driven. After the change step, a step of acquiring a third wave surface from the sensor that has received the light reflected by the first prototype, and
Assuming that the optical system is arranged based on the changed design information in the change step, the light reflected by the first prototype based on the changed design information of the optical system A calculation step for calculating the fourth wave surface acquired by the sensor, and
Change the modified design information of the optical system or drive at least a part of the first prototype and the optical system so that the difference between the third and fourth wave surfaces becomes smaller than a predetermined value. The measurement method according to any one of claims 1 to 7, further comprising a step of executing the above. The measuring method according to any one of claims 1 to 8, wherein the aspherical amount of each aspherical shape of the first and second prototypes is 0.05 mm or more. The measuring method according to any one of claims 1 to 9, wherein the difference between the central curvatures of the first and second prototypes is 0.001 (1 / mm) or more. Any of claims 1 to 10, further comprising a step of calculating the shape of the test surface based on the output from the sensor and the relative relationship between the test surface and the sensor. The measurement method according to item 1. The measuring method according to claim 11, wherein the relative relationship between the test surface and the sensor is acquired based on either a position magnification distribution, an angle magnification distribution, or ray tracing. Any of claims 1 to 12, further comprising a step of changing the design information of the optical system based on the output from the sensor before and after the rotation when the prototype is rotated about the optical axis. The measurement method according to item 1. An optical system that irradiates the test optical system with light emitted from a light source and guides the light transmitted through the test optical system to a sensor, and measures the transmitted wave surface of the test optical system based on the output from the sensor. It is a measurement method using a measuring device having a control unit and a control unit.
The acquisition step of acquiring the first wave surface corresponding to each reference optical system from the sensor that receives the light transmitted through the first reference optical system and the second reference optical system having different characteristics from each other.
Assuming that the optical system is arranged based on the design information, it corresponds to each prototype acquired by the sensor from each light transmitted through each reference optical system based on the design information of the optical system. The calculation step to calculate the second wave surface and
A measurement method comprising: at least a change step of changing the design information of the optical system so that the difference between the first and second wave planes corresponding to each reference optical system becomes smaller than a predetermined value. 14. The change step according to claim 14 , wherein the change step includes a step of calculating at least two parameters so that the difference between the first and second wave surfaces corresponding to each prototype is smaller than the predetermined value. Measurement method. The above two parameters are the arrangement of optical elements of the optical system, surface spacing, radius of curvature, surface shape, aberration, phase distribution, refractive index distribution, homogeneity, birefringence distribution, amount of linearity measurement error of light receiving sensor, wavelength of light source, and The measurement method according to claim 15 , wherein the amount of change is two of the respective amounts. The change step
A step of calculating a first parameter in which the low-order frequency wave plane changes so that the difference between the first and second wave planes corresponding to each reference optical system becomes smaller than the predetermined value, and
A step of calculating a second parameter in which the wave plane of a higher frequency changes based on the difference between the first and second wave planes corresponding to each reference optical system and the first parameter.
The measurement method according to claim 14, further comprising: at least a step of changing the design information of the optical system based on the first and second parameters. The first parameter is at least two of the arrangement of the optical elements of the optical system, the surface spacing, the radius of curvature, the amount of linearity measurement error of the light receiving sensor, and the wavelength of the light source.
The measurement method according to claim 17, wherein the second parameter is at least two of a surface shape, an aberration, a phase distribution, a refractive index distribution, a homogenity, and a birefringence distribution. An optical system that irradiates the test optical system with light emitted from a light source and guides the light transmitted through the test optical system to a sensor, and measures the transmitted wave surface of the test optical system based on the output from the sensor. It is a measurement method using a measuring device having a control unit and a control unit.
An acquisition step of acquiring a first wave surface corresponding to each reference optical system from the sensor that has received light transmitted through the first reference optical system and the second reference optical system having different characteristics from each other.
Assuming that the optical system is arranged based on the design information, it corresponds to each reference optical system acquired by the sensor from each light transmitted through each reference optical system based on the design information of the optical system. Calculation step to calculate the second wave surface to be
Based on the first and second wave planes, to each reference optical system of at least a part of the optical system, the first or second reference optical system, and at least two members of the sensor. A measurement method comprising, at least, a change step of changing the design information of the optical system so that the difference in the corresponding optical arrangements is small. The measuring method according to any one of claims 14 to 19, wherein in the changing step, at least a part of the members of the optical system is driven. After the change step, a step of acquiring a third wave surface from the sensor that has received light transmitted through the first reference optical system, and
Assuming that the optical system is arranged based on the design information changed in the change step, from the light transmitted through the first reference optical system based on the changed design information of the optical system. A calculation step for calculating the fourth wave surface acquired by the sensor, and
Changes in the modified design information of the optical system or at least a part of the members of the first reference optical system and the optical system so that the difference between the third and fourth wave planes becomes smaller than a predetermined value. The measuring method according to any one of claims 14 to 20, further comprising a step of executing driving. Claims 14 to 21 further include a step of calculating a transmitted wave surface of the optical system under test based on an output from the sensor and a relative relationship between the optical system under test and the sensor. The measurement method according to any one of the above. The measuring method according to claim 22, wherein the relative relationship between the optical system under test and the sensor is acquired based on either a position magnification distribution, an angle magnification distribution, or ray tracing. Any of claims 14 to 23, further comprising a step of changing the design information of the optical system based on the output from the sensor before and after the rotation when the reference optical system is rotated about the optical axis. The measurement method according to item 1. A measuring device, characterized in that the measuring method according to any one of claims 1 to 24 can be executed. A method for manufacturing an optical device, comprising a step of manufacturing an optical device including an optical element processed based on the measurement method according to any one of claims 1 to 24. The measuring device according to claim 25 and
An optical device manufacturing device including a manufacturing unit that manufactures an optical device including an optical element processed based on information from the measuring device.