JP6789441B2 - Wave surface measuring device - Google Patents

Description

The present invention relates to a wave surface measuring device for measuring the wave surface of a luminous flux from a subject.

Conventionally, a wave surface measuring device that corrects a change in focus caused by a change in atmospheric pressure has been known in order to accurately measure the wave surface. For example, Patent Document 1 describes a lens array, an optical system including a lens that projects light to be measured on the lens array, and a photoelectric converter that detects the position of a focused spot of the lens array by the light to be measured, and an error wave surface calculator. And a wave surface sensor equipped with a wave surface calculator are described. The error wave surface calculator calculates the change in the focus position of the lens caused by the change in atmospheric pressure, and converts the calculated change in the focus position into the change in the wave surface. The wave surface calculator subtracts the change in the wave plane obtained by the error wave plane calculator from the wave plane of the light to be measured based on the output of the photoelectric converter, so that the influence of the atmospheric pressure change in the wave plane measurement is reduced. ..

Japanese Unexamined Patent Publication No. 8-86689

The conventional wave surface measuring device described in Patent Document 1 assumes a fluctuation of the atmospheric pressure to the extent that linearity is established with respect to the atmospheric pressure, and corrects the fluctuation of the focus caused by the atmospheric pressure change.
On the other hand, when the atmospheric pressure is reduced from 1013 [hPa] (= 1E + 5 [Pa]) to a medium vacuum of 1 [Pa], which is about 5 orders of magnitude smaller, the refractive index of air changes and air convection disappears.
The conventional wave surface measuring device in this environment malfunctions in an electronic component that has difficulty in radiating heat because the focus position changes due to a change in the optical path length accompanying a change in the refractive index of air and there is no air convection. There was a problem that the wave surface could not be measured.

The present invention solves the above problems, and an object of the present invention is to obtain a wave surface measuring device capable of performing wave surface measurement even in an environment where the pressure is sufficiently reduced from atmospheric pressure.

The wave surface measuring device according to the present invention includes a wave surface dividing unit, a light receiving unit, a focus adjustment lens, a control circuit, an input / output unit, a housing, and a heat radiating unit. The wave surface dividing portion spatially divides the luminous flux from the subject. The light receiving unit receives a plurality of light fluxes divided by the wave surface dividing unit. The focus adjustment lens guides the light flux from the subject to the light receiving portion through the wave surface dividing portion. The control circuit controls the light receiving unit. The input / output unit outputs the signal acquired from the light receiving unit by the control circuit to the outside, and the information to the control circuit is input. The housing houses the wave surface dividing portion, the light receiving portion, the focus adjustment lens, the control circuit, and the input / output portion. The heat radiating section has a plate shape in which the control circuit and the input / output section are thermally connected to one surface and the other surface is black, and the focus is adjusted with one surface facing the inside of the housing. It is arranged at a position away from the optical axis of the light beam guided from the subject to the light receiving part by the lens, and heat from the control circuit and the input / output part is released to the outside of the housing by heat radiation.

According to the present invention, since the wave surface measuring device includes a heat radiating unit that releases heat from the control circuit and the input / output unit to the outside world by heat radiation, the wave surface measurement is performed even in an environment where the pressure is sufficiently reduced from the atmospheric pressure. It can be performed.

It is sectional drawing which shows the structure of the measurement system provided with the wave surface measuring apparatus which concerns on Embodiment 1 of this invention. It is sectional drawing which shows the structure of the wave surface measuring apparatus which concerns on Embodiment 1. FIG. FIG. 3A is a plan view showing a wave surface dividing portion in which light of a plane wave is incident. FIG. 3B is a plan view showing a light receiving portion in which the light flux divided by the wave surface dividing portion of FIG. 3A is incident. FIG. 3C is a cross-sectional arrow diagram showing a state in which the wave surface dividing portion and the light receiving portion on which the plane wave light is incident are cut along the BB line of FIG. 3A and the CC line of FIG. 3B. FIG. 3D is a diagram showing a wave surface of a plane wave. FIG. 4A is a plan view showing a wave surface dividing portion in which light spread in the traveling direction is incident. FIG. 4B is a plan view showing a light receiving portion in which the light flux divided by the wave surface dividing portion of FIG. 4A is incident. FIG. 4C is a cross-sectional arrow diagram showing a state in which the wave surface dividing portion and the light receiving portion on which the light spread in the traveling direction is incident are cut along the DD line of FIG. 4A and the EE line of FIG. 4B. is there. FIG. 4D is a diagram showing a wave surface of light that spreads in the traveling direction. It is sectional drawing which shows the wave surface measuring apparatus when the heat radiating part connected to a housing is thermally deformed. It is sectional drawing which shows the wave surface measuring apparatus when the heat radiating part connected to the housing through a buffer part is thermally deformed. It is sectional drawing which shows the structure of the wave surface measuring apparatus which concerns on Embodiment 2 of this invention. It is sectional drawing which shows the wave surface measuring apparatus when the heat radiating part connected to the part on the front side of the light receiving part in a housing is thermally deformed. It is sectional drawing which shows the structure of the modification of the wave surface measuring apparatus which concerns on Embodiment 2. It is sectional drawing which shows the structure of the wave surface measuring apparatus which concerns on Embodiment 3 of this invention.

Hereinafter, in order to explain the present invention in more detail, a mode for carrying out the present invention will be described with reference to the accompanying drawings.
Embodiment 1.
When light is transmitted or reflected through a medium, the spatial distribution of the phase of the light changes. Since light is an electromagnetic wave, the spatial distribution of the phase of light is understood as a wave plane. The wavefront measuring device measures the performance of a subject using the wavefront of light, and is realized by, for example, a Shack-Hartmann type wavefront sensor. The subject is an optical component such as a lens or a mirror.

FIG. 1 is a cross-sectional view showing the configuration of a measurement system including the wave surface measuring device according to the first embodiment of the present invention. The wave surface measuring device according to the first embodiment includes a main body 1 and a calculation device 6. In the measurement system shown in FIG. 1, the main body 1 and the subject 2 are housed in a vacuum container 3, and the inside of the vacuum container 3 is in a vacuum environment in which air is exhausted by an exhaust device 4. This measurement system simulates, for example, a medium vacuum environment in which the atmospheric pressure is about 5 orders of magnitude smaller than the atmospheric pressure. Further, the vacuum container 3 is provided with an input / output terminal 5.

The input / output terminals 5 are provided with wiring for connecting the computing device 6 outside the vacuum vessel 3 and the main body 1, and an optical fiber 8 for guiding the light from the light source 7 to the main body 1. The calculation device 6 is a general-purpose calculation device typified by a personal computer. The light source 7 outputs light for obtaining a luminous flux A on the optical axis a. In the example shown in FIG. 1, the light source 7 is provided outside the main body 1. However, the light source 7 may be provided inside the main body 1. When the light output from the light source 7 is guided to the main body 1 through the optical fiber 8, it is guided from the main body 1 to the subject 2 and reflected by the subject 2. This reflected light is the luminous flux A.

The wiring provided in the input / output terminal 5 includes a data signal line b, a measurement signal line c, and a power supply line d. The data signal line b is a wiring through which a data signal exchanged between the main body 1 and the computing device 6 is propagated. The data signal line b is connected to the input / output unit 10 included in the main body 1, and the input / output unit 10 relays the data signal exchanged between the main body 1 and the calculation device 6. The measurement signal line c is connected to the temperature measurement unit 11 included in the main body 1, and the temperature measurement signal measured by the temperature measurement unit 11 is output to the calculation device 6 through the measurement signal line c. The electric power from the computing device 6 is supplied to the internal circuit of the main body 1 through the power supply line d. The data signal line b and the measurement signal line c may be wired or wireless.

Consider a case where the inside of the vacuum vessel 3 in the measurement system is depressurized from atmospheric pressure to a medium vacuum of about 1 [Pa] by using an exhaust device 4 and a barometer 9. In this case, the pressure inside the vacuum vessel 3 is about 5 orders of magnitude smaller than the atmospheric pressure of 1013 [hPa] = 1E + 5 [Pa]. In such a decompressed environment, the air is extremely thin, so that the physical phenomenon of air convection does not occur.

Since there is no convection of air, the main body 1 does not have to consider the fluctuation of the atmosphere when measuring the wave surface of the luminous flux A from the subject 2. On the other hand, when the pressure is reduced to medium vacuum, the refractive index of air changes from, for example, 1.0003 to 1.0000, so that the optical path length fluctuates and the focus position shifts. Since there is no convection of air, the heat from the internal circuit of the main body 1 is not exhausted into the atmosphere and the heat is accumulated inside the main body 1. When the temperature rises due to the accumulation of heat, the internal circuit of the main body 1 tends to malfunction.

The wave surface measuring device according to the first embodiment has a configuration for reducing the above-mentioned problems under reduced pressure. FIG. 2 is a cross-sectional view showing the configuration of the wave surface measuring device according to the first embodiment. In FIG. 2, the description of the subject 2 and the input / output terminal 5 shown in FIG. 1 is omitted. The input / output section 10 and the control circuit 12 are internal circuits of the main body section 1, and are thermally connected to one surface of the heat dissipation section 14 by the adhesive section 13. The heat radiating unit 14 has a plate shape in which the input / output unit 10 and the control circuit 12 are thermally connected to one surface and the other surface is black. The heat radiating unit 14 is arranged at a position in the housing 15 away from the optical axis a of the luminous flux A so that one surface to which the input / output unit 10 and the control circuit 12 are thermally connected faces the inside of the housing 15. Will be done. The position away from the optical axis a may be, for example, a position parallel to the optical axis a in the housing 15. The heat radiating unit 14 releases heat from the input / output unit 10 and the control circuit 12 to the outside of the housing 15 by heat radiation.

The housing 15 is, for example, a box-shaped member having an open side. Temperature measurement unit 11a, temperature measurement unit 11b, control circuit 12, wave surface division unit 17, light receiving unit 18, optical path division unit 19, collimating lens 20, focus adjustment lens 21, translation mechanism 22, calibration prototype 23 and optical path switching unit 24 is housed in the housing 15. The heat radiating unit 14 is arranged so that the surface on the side to which the input / output unit 10 and the control circuit 12 are connected faces the inside of the housing 15 and covers the opening of the housing 15 via the cushioning unit 16. Since the buffer portion 16 is interposed, there is a gap between the heat radiating portion 14 and the housing 15.

The calculation device 6 includes a calculation unit 6a, a power supply unit 6b, a cutoff unit 6c, and a temperature storage unit 6d. As shown in FIG. 2, the input / output unit 10 is connected to the calculation unit 6a by the data signal line b, and is an interface for data signals exchanged between the calculation unit 6a and the control circuit 12. For example, the input / output unit 10 functions as an interface of a general-purpose standard represented by USB, RJ45, RS232C and IEEE1394.

The power supply unit 6b is connected to the control circuit 12 by a power supply line d, and a cutoff unit 6c is provided between the power supply unit 6b and the control circuit 12. The electric power from the power supply unit 6b is supplied to the control circuit 12 through the power supply line d. The temperature measurement unit 11a and the temperature measurement unit 11b are the temperature measurement units 11 shown in FIG. 1, and the measurement signal line c1 and the measurement signal line c2 are the measurement signal lines c shown in FIG. The temperature storage unit 6d is connected to the temperature measurement unit 11a via the measurement signal line c1 and is connected to the temperature measurement unit 11b via the measurement signal line c2.

The temperature measuring unit 11a measures the temperature of the control circuit 12, and the temperature measuring unit 11b measures the temperature of the light receiving unit 18. The temperature storage unit 6d inputs a measurement signal from the temperature measurement unit 11a via the measurement signal line c1 and inputs and stores the measurement signal from the temperature measurement unit 11b via the measurement signal line c2. Further, the temperature storage unit 6d also has a function of comparing the temperature indicated by the measurement signal with the operation guaranteed temperature range and notifying the blocking unit 6c of the comparison result. Electronic components made of semiconductors have a temperature range in which operation is guaranteed. If the temperature of the electronic component rises and exceeds the guaranteed operating temperature range, the operation of the electronic component becomes unstable, which may cause a failure. The control circuit 12 and the light receiving unit 18 are electronic components having an operation guaranteed temperature range, and these operation guaranteed temperature ranges are preset in the temperature storage unit 6d.

The cutoff unit 6c cuts off the power supply to the control circuit 12 when the comparison result indicating that the temperature indicated by the measurement signal exceeds the guaranteed operating temperature range is notified. On the other hand, when the comparison result indicating that the temperature indicated by the measurement signal has returned to the guaranteed operating temperature range is notified, the cutoff unit 6c restarts the power supply to the control circuit 12. Further, the cutoff unit 6c cuts off the power supply when a preset time elapses after the power is supplied to the control circuit 12, and when the power supply is cut off and the preset time elapses. Resume power supply.

The target for measuring the temperature by the temperature measuring unit 11 is not limited to the control circuit 12 and the light receiving unit 18. For example, the temperature measuring unit 11 measures the temperatures of the input / output unit 10, the heat radiating unit 14, and the housing 15, and the blocking unit 6c supplies power to the control circuit 12 based on the temperature measured by the temperature measuring unit 11. May be shut off and restarted.

The light input from the light source 7 to the main body 1 through the optical fiber 8 is converted into parallel light by the collimating lens 20. The optical path dividing portion 19 is an optical component realized by a beam splitter. The light converted into parallel light by the collimating lens 20 is guided to the optical path on the focus adjusting lens 21 side by the optical path dividing unit 19. This optical path continues to the outside of the housing 15 through the opening 15a, and the subject 2 shown in FIG. 1 is arranged ahead of the optical path. The light guided to the subject 2 is reflected by the subject 2, and the luminous flux A of the reflected light propagates in the optical path and returns to the main body 1. When the light source 7 outputs visible light and the housing 15 is made of a transparent member (for example, glass), the visible light flux passes through the wall surface of the housing 15, so that the opening 15a may not be present. ..

The luminous flux A from the subject 2 returned to the main body 1 is guided to the light receiving unit 18 by the focus adjusting lens 21 through the optical path dividing portion 19 and the wave surface dividing portion 17. The light receiving unit 18 receives the light flux divided into a plurality by the wave surface dividing unit 17. The light receiving unit 18 is realized by a charge-coupled device (CCD) or a CMOS image sensor, and acquires two-dimensional image information from the received optical signal. The light receiving unit 18 and the control circuit 12 are connected by wiring e.
The control circuit 12 controls so-called exposure, in which the light receiving unit 18 receives the light from the wave surface dividing unit 17. Further, the control circuit 12 controls reading of a signal (a signal indicating a focusing spot described later) from the light receiving unit 18.

The translation mechanism 22 translates the focus adjustment lens 21 along the optical axis a of the luminous flux A from the subject 2 in the direction indicated by the double-headed arrow in FIG. For example, when the measurement system shown in FIG. 1 is decompressed to a medium vacuum and the refractive index of air changes and the optical path length fluctuates, the translation mechanism 22 translates the focus adjustment lens 21 and causes the fluctuation of the optical path length. Correct the shift of the focus position.

The calibration prototype 23 reflects the incident light flux, and is realized by, for example, a reflecting mirror. As shown by the double-headed arrow in FIG. 2, the optical path switching unit 24 moves the calibration prototype 23 in and out of the optical path between the subject 2 and the focus adjustment lens 21. That is, the calibration prototype 23 is arranged by the optical path switching unit 24 on the optical axis a indicating the direction that serves as a reference for the propagation of the luminous flux. The focus adjustment lens 21 guides the light flux reflected from the calibration prototype 23 to the light receiving unit 18 through the wave surface dividing unit 17.

The wavefront measuring device according to the first embodiment is realized by a Shack-Hartmann type wavefront sensor. This wavefront sensor is configured to include a lens array in which a plurality of lenses are arranged and an imaging device. The lens array is the wave surface dividing unit 17 shown in FIG. 2, and the imaging device is the light receiving unit 18 shown in FIG.

FIG. 3A is a plan view showing the wave surface dividing portion 17 in which the light of the plane wave is incident. FIG. 3B is a plan view showing a light receiving unit 18 in which the light flux A divided by the wave surface dividing unit 17 of FIG. 3A is incident. FIG. 3C is a cross-sectional arrow diagram showing a state in which the wave surface dividing portion 17 and the light receiving portion 18 on which the plane wave light is incident are cut along the BB line of FIG. 3A and the CC line of FIG. 3B. FIG. 3D is a diagram showing a wave surface 18a1 of a plane wave, and the Z axis corresponds to the optical axis of the luminous flux A. As shown in FIGS. 3A and 3C, the wave surface of the light flux A propagating from the subject 2 shown in FIG. 1 as a plane wave is spatially divided by a plurality of lenses included in the wave surface dividing portion 17. As shown in FIG. 3B, each of the light spatially divided by the wave surface dividing section 17 is focused on the imaging surface of the light receiving section 18, and a point image 18a of the focused spot is formed at the light focusing position. To.

The light collected on the imaging surface is photoelectrically converted into an electric signal by the light receiving unit 18. The signal obtained by the photoelectric conversion is a signal indicating a focused spot. The control circuit 12 acquires a signal indicating a condensing spot from the light receiving unit 18 through the wiring e. The control circuit 12 outputs a signal indicating the condensing spot to the calculation unit 6a of the calculation device 6 via the input / output unit 10. The calculation unit 6a quantitatively calculates the position of the condensing spot and the spread of the luminous flux A based on the signal input from the control circuit 12. As shown in FIG. 3C, the point image 18a derived from the luminous flux A of the plane wave is distributed at each of the center positions of the plurality of lenses included in the lens array (wave surface dividing portion 17).

FIG. 4A is a plan view showing a wave surface dividing portion 17 in which light spread in the traveling direction is incident. FIG. 4B is a plan view showing a light receiving unit 18 in which the light flux divided by the wave surface dividing unit 17 of FIG. 4A is incident. FIG. 4C is a cross-sectional arrow showing a state in which the wave surface dividing portion 17 and the light receiving portion 18 on which the light spread in the traveling direction is incident are cut along the DD line of FIG. 4A and the EE line of FIG. 4B. It is a figure. FIG. 4D is a diagram showing a wave surface 18b1 of light that spreads in the traveling direction, and the Z axis corresponds to the optical axis of the luminous flux A.

As shown in FIGS. 4A and 4C, the luminous flux A spreading and propagating from the subject 2 shown in FIG. 1 in the traveling direction is spatially divided by a plurality of lenses included in the wave surface dividing portion 17. As shown in FIG. 4B, each of the light spatially divided by the wave surface dividing section 17 is focused on the imaging surface of the light receiving section 18, and a point image 18b of the focused spot is formed at the light focusing position. Will be done. As shown in FIG. 4C, the point image 18b derived from the luminous flux A that has spread and propagated in the traveling direction is located at a position deviated from each of the center positions of the plurality of lenses included in the lens array (wave surface dividing portion 17). It is distributed.

As described above, the spatial distribution of the point image correlates with the local inclination of the wave surface incident on the lens array. Therefore, as shown in FIG. 3D, the wave surface 18a1 incident on the lens array is obtained from the spatial distribution of the point image 18a, and as shown in FIG. 4D, it is incident on the lens array from the spatial distribution of the point image 18b. The wave surface 18b1 is required. As a method of measuring the wave surface from the position of the point image, various existing methods may be used.

Up to now, the case where the wave surface dividing portion 17 is a lens array in which a plurality of lenses are arranged in a grid pattern has been shown, but a lens array in which a plurality of lenses are arranged in a honeycomb shape may be used.
As shown in FIGS. 3A and 4A, the lens array may be colored black between each of the plurality of lenses constituting the lens array so that unnecessary light is not transmitted to adjacent lenses, and absorbs the light. Alternatively, it may be processed to scatter.

The refractive index of air changes under the influence of atmospheric pressure (partial pressure of dry air and partial pressure of water vapor) and atmospheric fluctuations caused by air temperature. In this case, the fluctuation of the refractive index is small, but as the optical path length through which the light propagates becomes longer, the magnitude becomes non-negligible as compared with the wavelength of the light. Therefore, the wave surface measurement is generally strongly influenced by the fluctuation of the atmosphere. Therefore, in order to reduce the influence of atmospheric fluctuations, wave surface measurement may be performed in an environment where air is removed.

Further, the noise contained in the output of the light receiving unit 18 may increase in proportion to the temperature rise, and the housing 15 may be distorted due to the temperature rise. When the housing 15 is distorted, the inclination or position of the optical member on the optical path is displaced, which adversely affects the wave surface measurement. Further, in a decompressed environment, the air pressure on the housing 15 may decrease and the housing 15 may be distorted.
Therefore, the wave surface measuring device according to the first embodiment has the following features (1) to (9) for solving the above problems.

As a feature (1), the input / output unit 10 and the control circuit 12 are arranged apart from the light receiving unit 18, and the control circuit 12 and the light receiving unit 18 are connected by wiring e. The light receiving unit 18 measures the focused spot of the luminous flux A from the subject 2, and the operating state of the light receiving unit 18 greatly affects the accuracy of the wave surface measurement. On the other hand, the input / output unit 10 and the control circuit 12 generate heat during operation and tend to be heat sources. Therefore, by arranging the input / output unit 10 and the control circuit 12 which are likely to be heat sources apart from the light receiving unit 18, the temperature rise of the light receiving unit 18 is reduced.

As a feature (2), the input / output unit 10 and the control circuit 12 are thermally connected to the heat dissipation unit 14. For example, the input / output unit 10 and the control circuit 12 are connected to the heat dissipation unit 14 by the adhesive unit 13. The heat radiating unit 14 releases heat from the input / output unit 10 and the control circuit 12 to the outside world (outside the housing 15) by heat radiation. For the adhesive portion 13, for example, an adhesive material having thermal conductivity is used. Further, for the heat radiating portion 14, a material having a relatively higher thermal conductivity than that of the adhesive portion 13 is used. Even in a depressurized environment where there is no air convection, the heat from the input / output unit 10 and the control circuit 12 is thermally conducted through the adhesive unit 13 and transferred to the heat dissipation unit 14, and is transferred to the outside of the housing 15 by the heat dissipation unit 14. It is released.

By connecting the input / output unit 10 and the control circuit 12 near the center of the surface of the heat dissipation unit 14, the temperature gradient due to heat from the input / output unit 10 and the control circuit 12 is moved from the center of the surface of the heat dissipation unit 14 to the periphery. Become symmetric. Therefore, the temperature of the heat radiating unit 14 becomes uniform as compared with the case where the input / output unit 10 and the control circuit 12 are connected to the end of the surface of the heat radiating unit 14, and distortion due to the temperature rise of the heat radiating unit 14 can be reduced.

As a feature (3), the heat radiating unit 14 is arranged at a position away from the optical axis a of the light flux A guided from the subject 2 to the light receiving unit 18 by the focus adjusting lens 21. In the example shown in FIG. 2, the heat radiating portion 14 is arranged on the upper portion of the housing 15 in a state parallel to the optical axis a. However, the heat radiating portion 14 may be arranged at the lower part of the housing 15 as long as it is located away from the optical axis a of the luminous flux A. Since the heat radiating unit 14 is arranged at a position away from the optical axis a, it is possible to reduce the influence of the distortion of the housing 15 due to the thermal deformation of the heat radiating unit 14 described later on the optical path.

As a feature (4), the heat radiating portion 14 has a black surface that does not face the optical axis a. The surface of the heat radiating unit 14 that does not face the optical axis a is a surface that faces the outside of the housing 15 as shown in FIG. In order to promote heat transfer by heat radiation of the heat radiation unit 14, the surface of the heat radiation unit 14 that does not face the optical axis a is colored or blackened in black to increase the efficiency of heat radiation.

As a feature (5), the heat radiating portion 14 is arranged with a gap between it and the housing 15 via the buffering portion 16. The cushioning portion 16 may be a member that reduces the stress from the heat radiating portion 14, and is, for example, a spring-shaped elastic member. Further, for the buffer portion 16, a material having a relatively small thermal conductivity as compared with the heat radiating portion 14 and the housing 15 is used. Since there is a gap between the heat radiating unit 14 and the housing 15, it is possible to prevent stress due to thermal deformation (thermal expansion or contraction) due to the temperature rise of the heat radiating unit 14 from being applied to the housing 15. Further, since there is a gap between the heat radiating portion 14 and the housing 15, the atmosphere inside the housing 15 can be sufficiently exhausted by the exhaust device 4.

FIG. 5 is a cross-sectional view showing a wave surface measuring device when the heat radiating portion 14 directly connected to the housing 15 is thermally deformed. The main body 1a is not provided with a shock absorbing portion 16, and the heat radiating portion 14 is directly connected to the housing 15. The heat radiating unit 14 may be thermally expanded and distorted due to an increase in temperature. When there is no buffer portion 16, the stress generated in the heat radiating portion 14 due to thermal deformation is transmitted to the housing 15 and distorts the housing 15. The housing 15 is provided with an opening 15a through which the light flux A passes on the wall surface, and houses optical elements such as a wave surface dividing portion 17, a light receiving portion 18, an optical path dividing portion 19, and a focus adjusting lens 21. When the housing 15 is distorted, as shown in FIG. 5, the position or inclination of the optical element with respect to the luminous flux A is deviated from the state before the distortion.

FIG. 6 is a cross-sectional view showing a wave surface measuring device when the heat radiating portion 14 connected to the housing 15 via the buffer portion 16 is thermally deformed. In the main body 1, the heat radiating portion 14 is arranged with a gap between the heat radiating portion 14 and the housing 15 via the buffer portion 16. The stress generated in the heat radiating portion 14 due to the thermal deformation is absorbed by the buffer portion 16 and is difficult to be transmitted to the housing 15. Therefore, as shown in FIG. 6, the position or inclination of the optical element with respect to the luminous flux A is maintained.

As a feature (6), the translation mechanism 22 translates the focus adjustment lens 21 along the optical axis a of the luminous flux A guided from the subject 2 to the light receiving portion 18. Even if the optical path length changes according to the fluctuation of the atmospheric pressure, the translation mechanism 22 translates the focus adjustment lens 21 along the optical axis a, so that the deviation of the focus position can be corrected. As the translation mechanism 22, a driving device that drives even in an environment with low atmospheric pressure and does not easily generate heat is used.

The fluctuation of the refractive index of air due to depressurization from atmospheric pressure to medium vacuum is small, but the amount of change in the refractive index of air according to the temperature or pressure increases as the optical path length increases.
In particular, when the optical path length from the main body 1 to the subject 2 is long, the spatial distribution of the point image obtained by the light receiving unit 18 is greatly distorted, and the image may be formed on the outside of the imaging surface of the light receiving unit 18.
Further, the relative positional relationship between the plurality of lenses constituting the wave surface dividing portion 17 and the point image obtained by the light receiving portion 18 cannot be grasped from the spatial distribution of the point image.

On the other hand, the translation mechanism 22 translates the focus adjustment lens 21 along the optical axis a of the luminous flux A to correct the influence of the above-mentioned fluctuation of the optical path length, so that, for example, the imaging surface of the light receiving unit 18 The point image formed on the outside of the lens can be returned to the imaging surface of the light receiving unit 18. By this correction, the relative positional relationship between the plurality of lenses constituting the wave surface dividing unit 17 and the point image obtained by the light receiving unit 18 can be grasped from the spatial distribution of the point image, and the wave surface can be measured.

The wavefront sensor described in Patent Document 1 converts the change in the focus position into the change in the wavefront to correct the influence of the fluctuation of the atmospheric pressure. In this correction method, it is assumed that the focus position is deviated to the extent that the wavefront can be measured by the wavefront sensor.
On the other hand, since the wave surface measuring device according to the first embodiment has the translation mechanism 22, the focus position can be corrected even if the wave surface cannot be measured due to the fluctuation of the optical path length.

As a feature (7), the optical path switching unit 24 moves the calibration prototype 23 in and out of the optical path between the subject 2 and the focus adjustment lens 21. When the calibration prototype 23 is arranged in the optical path between the subject 2 and the focus adjustment lens 21, the luminous flux reflected from the optical path dividing portion 19 toward the subject 2 is reflected toward the focus adjustment lens 21. To do. The focus adjustment lens 21 guides the light flux reflected from the calibration prototype 23 to the light receiving unit 18 through the wave surface dividing unit 17. As a result, the light receiving unit 18 obtains the spatial distribution of the point image derived from the luminous flux reflected from the calibration prototype 23, and the wave surface is measured by the calculation device 6 from this spatial distribution. From the difference between the wave surface measured from the luminous flux A from the subject 2 and the wave surface measured from the luminous flux reflected from the calibration prototype 23, the wave surface of the luminous flux A from the subject 2 (accurately). Since the path is twice that of the outward path and the return path, a wave surface that is twice the luminous flux A from the subject 2) is required.

The wave surface measuring device according to the first embodiment measures the wave surface derived from the luminous flux from the calibration prototype 23 in an atmospheric pressure environment, and subsequently reduces the pressure from the atmospheric pressure to about 1 [Pa]. Below, the wave surface derived from the luminous flux from the calibration prototype 23 is measured. Since the shape of the calibration prototype 23 does not change due to atmospheric pressure fluctuations, if there is a difference in the measured value of the wave surface derived from the luminous flux from the calibration prototype 23 before and after the atmospheric pressure fluctuation, this difference will cause the atmospheric pressure to fluctuate. This is the amount of change in the wave surface generated in the optical system inside the main body 1. This amount of change corresponds to the amount of deviation of the focus position.
Since the wave surface measuring device according to the first embodiment has the feature (7), the deviation of the focus position due to the atmospheric pressure fluctuation can be evaluated by actual measurement without performing a calculation such as an atmospheric model.

As a feature (8), the wave surface measuring device according to the first embodiment includes a temperature measuring unit 11 for measuring the temperature, and from the power supply unit 6b to the control circuit 12 based on the temperature measured by the temperature measuring unit 11. It is provided with a shutoff unit 6c that shuts off and restarts the power supply.
The cutoff unit 6c cuts off the power supply to the control circuit 12 when the comparison result indicating that the temperature indicated by the measurement signal exceeds the guaranteed operating temperature range is notified. On the other hand, when the comparison result indicating that the temperature indicated by the measurement signal has returned to the guaranteed operating temperature range is notified, the cutoff unit 6c restarts the power supply to the control circuit 12.

As a feature (9), the cutoff unit 6c cuts off the power supply from the power supply unit 6b to the control circuit 12 based on the time when the power is supplied to the control circuit 12.
When power is supplied to the electronic component and the operation is continued, the temperature of the electronic component rises. For example, even if the control circuit 12 is radiated by the heat radiating unit 14, if the operation is continued for a long time, the temperature of the control circuit 12 may rise and exceed the guaranteed operation temperature range.
Therefore, when the power supply to the control circuit 12 is started and the operation is continuously performed, the time during which the temperature of the control circuit 12 is maintained within the guaranteed operation temperature range is defined as T1. Let T2 be the time until the temperature of the control circuit 12 from which the power supply is cut off returns to the guaranteed operating temperature range. The time T1 and the time T2 are, for example, obtained by an experiment in advance and set in the blocking unit 6c.
The cutoff unit 6c cuts off the power supply when the power supply time to the control circuit 12 elapses the time T1. On the other hand, when the time T2 elapses after the power supply is cut off, the cutoff unit 6c resumes the power supply to the control circuit 12.

As described above, the wave surface measuring device according to the first embodiment includes the heat radiating unit 14 that releases the heat from the control circuit 12 and the input / output unit 10 to the outside world by heat radiation, so that the pressure is sufficiently reduced from the atmospheric pressure. Wave surface measurement can be performed even in a new environment.

In the wave surface measuring device according to the first embodiment, the heat radiating unit 14 is arranged with a gap between it and the housing 15 via the buffer unit 16. With this configuration, the stress generated in the heat radiating portion 14 due to thermal deformation is absorbed by the buffer portion 16 and is not transmitted to the housing 15, and even if the heat radiating portion 14 is thermally deformed, the optical element in the housing 15 The position or tilt can be maintained.

The wave surface measuring device according to the first embodiment includes a translation mechanism 22 that translates the focus adjustment lens 21 along the optical axis a. By having this configuration, the wave surface measuring device can correct the focus position even if the wave surface cannot be measured due to the fluctuation of the optical path length.

The wave surface measuring device according to the first embodiment is an optical path switching between the calibration prototype 23 that reflects the incident luminous flux A and the optical path that moves the calibration prototype 23 in and out of the optical path between the focus adjustment lens 21 and the subject 2. A unit 24 is provided. The focus adjusting lens 21 guides the luminous flux A reflected from the calibration prototype 23 arranged in the optical path between the subject 2 and the subject 2 by the optical path switching unit 24 to the light receiving unit 18 through the wave surface dividing unit 17. With this configuration, the wave surface measuring device can measure the wave surface derived from the light flux reflected from the calibration prototype 23. Further, the wave surface measuring device uses the wave surface derived from the luminous flux from the calibration prototype 23 measured before and after the fluctuation of the atmospheric pressure, so that the deviation of the focus position due to the fluctuation of the atmospheric pressure can be calculated without calculating the atmospheric model or the like. It can be evaluated by actual measurement.

The wave surface measuring device according to the first embodiment includes a blocking unit 6c, a temperature measuring unit 11a, and a temperature measuring unit 11b. The temperature measuring unit 11a measures the temperature of the control circuit 12, and the temperature measuring unit 11b measures the temperature of the light receiving unit 18. The cutoff unit 6c cuts off the power supply to the control circuit 12 based on either the temperature measured by the temperature measurement unit 11a and the temperature measurement unit 11b and the time during which the power is continuously supplied to the control circuit 12. And resume.
By having this configuration, the wave surface measuring device can prevent the internal parts from operating beyond the guaranteed operating temperature range, and can reduce the occurrence of malfunction due to the temperature rise.

Embodiment 2.
FIG. 7 is a cross-sectional view showing the configuration of the wave surface measuring device according to the second embodiment of the present invention. In FIG. 7, the same components as those in FIG. 2 are designated by the same reference numerals, and the description thereof will be omitted. The main body 1A of the wave surface measuring device according to the second embodiment includes a heat radiating portion 14A and a housing 15A as components different from the main body 1. The imaging surface described in the first embodiment is the front surface of the light receiving unit 18. As shown in FIG. 7, the housing 15A has a box shape extending to the back side of the light receiving portion 18, and has an internal space on the back side of the light receiving portion 18 as compared with the housing 15 shown in the first embodiment. Is getting bigger. The housing 15A is partially open on the back surface side of the light receiving portion 18.

The heat radiating unit 14A is a plate-shaped member in which the input / output unit 10 and the control circuit 12 are thermally connected to one surface by the adhesive unit 13 and the other surface is black. The heat radiating portion 14A may have a size that can cover the opening of the housing 15A, for example. The heat radiating unit 14A is arranged so that the surface on the side to which the input / output unit 10 and the control circuit 12 are connected faces the inside of the housing 15A and covers the opening of the housing 15A via the cushioning unit 16. Since the buffer portion 16 is interposed, there is a gap between the heat radiating portion 14A and the housing 15A.

For example, the main body 1A and the subject 2 are arranged in the vacuum container 3 shown in FIG. When the vacuum vessel 3 is decompressed to about 1 [Pa], the contribution of heat transport due to air convection is reduced, so that the temperature rise of the input / output unit 10 and the control circuit 12 of the main body 1A becomes remarkable. However, also in the wave surface measuring device according to the second embodiment, the heat radiating unit 14A releases the heat from the input / output unit 10 and the control circuit 12 to the outside world (outside the housing 15A) by heat radiation.

FIG. 8 is a cross-sectional view showing a wave surface measuring device when the heat radiating portion 14A connected to the front side portion of the light receiving portion 18 in the housing 15A1 is thermally deformed. Unlike the housing 15A, the housing 15A1 has a part of the wall surface on the front side of the light receiving portion 18 open, as shown in FIG. Since the front surface of the light receiving unit 18 is the imaging surface, the optical system of the main body 1b is arranged in the space on the front side of the light receiving unit 18 in the housing 15A. The heat radiating unit 14A is directly connected so that the surface on the side to which the input / output unit 10 and the control circuit 12 are connected faces the inside of the housing 15A1 and covers the opening of the housing 15A1.

When the heat radiating unit 14A is distorted due to the temperature rise, stress is generated due to the distortion of the heat radiating unit 14A. The stress generated in the heat radiating portion 14A due to the thermal deformation is transmitted to the housing 15A1, and as shown in FIG. 8, the front side of the light receiving portion 18 in the housing 15A1 is distorted. An opening 15a through which the luminous flux A passes is provided on the wall surface in the front portion of the light receiving portion 18 in the housing 15A1, and optics such as a wave surface dividing portion 17, a light receiving portion 18, an optical path dividing portion 19, and a focus adjusting lens 21. Contains the elements. Therefore, when the above portion of the housing 15A1 is distorted, the position or inclination of the optical element with respect to the luminous flux A is deviated from the state before the distortion.

On the other hand, in the wave surface measuring device according to the second embodiment, the heat radiating portion 14A is provided on the back surface side portion of the light receiving portion 18 in the housing 15A, and is connected to the housing 15A via the buffer portion 16. They are arranged with a gap. Since the shock absorbing portion 16 absorbs the stress generated in the heat radiating portion 14A due to the thermal deformation, it is difficult to be transmitted to the housing 15A. Even if the stress from the heat radiating portion 14A is transmitted to the back surface side portion of the light receiving portion 18 in the housing 15A, the position or inclination of the optical element with respect to the luminous flux A is maintained because the optical system is not arranged in this portion. ..

Further, the wave surface measuring device according to the second embodiment may be configured as follows.
FIG. 9 is a cross-sectional view showing a configuration of a modified example of the wave surface measuring device according to the second embodiment. In FIG. 9, the same components as those in FIG. 2 are designated by the same reference numerals, and the description thereof will be omitted. The main body 1B includes a heat radiating portion 14B and a housing 15B as components different from the main body 1. As shown in FIG. 9, the housing 15B has a box shape extending to the back side of the light receiving portion 18, and the internal space on the back side of the light receiving portion 18 is large like the housing 15A. The housing 15B has an opening at a portion facing the back surface of the light receiving portion 18.

The heat radiating unit 14B is a plate-shaped member in which the input / output unit 10 and the control circuit 12 are thermally connected to one surface by the adhesive unit 13, and the other surface is black. The heat radiating portion 14B may have a size that can cover the opening of the housing 15B, for example. The heat radiating unit 14B is arranged so that the surface on the side to which the input / output unit 10 and the control circuit 12 are connected faces the inside of the housing 15B and covers the opening of the housing 15B via the buffer portion 16. Since the buffer portion 16 is interposed, there is a gap between the heat radiating portion 14B and the housing 15B.

The heat radiating portion 14B is provided in a portion of the housing 15B facing the back surface of the light receiving portion 18, and is arranged with a gap between the heat radiating portion 14B and the housing 15B via the buffer portion 16.
Since the shock absorbing portion 16 absorbs the stress generated in the heat radiating portion 14B due to the thermal deformation, it is difficult to be transmitted to the housing 15B. Even if the portion of the housing 15B facing the back surface of the light receiving portion 18 is damaged due to the stress transmitted from the heat radiating portion 14B, the position or inclination of the optical element with respect to the luminous flux A is maintained because the optical system is not arranged in this portion. Ru.

As described above, in the wave surface measuring device according to the second embodiment, the heat radiating portions 14A and 14B are arranged on the back surface side portion of the light receiving portion 18 in the housings 15A and 15B.
By having this configuration, the stress generated in the heat radiating portions 14A and 14B due to the thermal deformation is absorbed by the buffer portion 16 and is not transmitted to the housings 15A and 15B, and even if the heat radiating portions 14A and 14B are thermally deformed, the optical element Position or tilt can be maintained.

Embodiment 3.
FIG. 10 is a cross-sectional view showing the configuration of the wave surface measuring device according to the third embodiment of the present invention. In FIG. 10, the same components as those in FIG. 2 are designated by the same reference numerals, and the description thereof will be omitted.
The main body 1C of the wave surface measuring device according to the third embodiment includes a heat radiating unit 14C as a component different from the main body 1. The heat radiating unit 14C is a plate-shaped member in which the input / output unit 10 and the control circuit 12 are thermally connected to one surface by the adhesive unit 13, and the other surface is black. As shown in FIG. 10, the heat radiating portion 14C has a black surface having an uneven surface. The heat exchanger 25 has an uneven surface that is combined with the uneven surface of the heat radiating portion 14C, and exchanges heat with the heat radiating portion 14C through the uneven surface. The heat bath 26 exhausts the heat exchanged by the heat exchanger 25.

For example, the main body 1C and the subject 2 are arranged in the vacuum container 3 shown in FIG. When the vacuum vessel 3 is depressurized to about 1 [Pa], the contribution of heat transport due to air convection is reduced, so that the temperature rise of the input / output unit 10 and the control circuit 12 becomes remarkable. When the heat radiating unit 14C releases the heat from the input / output unit 10 and the control circuit 12 to the outside of the housing 15 by heat radiation, the thermal environment inside the vacuum vessel 3 may change.

On the other hand, in the wave surface measuring device according to the third embodiment, as shown in FIG. 10, the uneven surface of the heat radiating portion 14C is arranged in combination with the uneven surface of the heat exchanger 25. As a result, the heat from the heat radiating unit 14C is efficiently transferred to the heat exchanger 25. The heat from the heat exchanger 25 is exhausted in the heat bath 26 provided outside the vacuum vessel 3. This makes it possible to prevent changes in the thermal environment inside the vacuum container 3.

As described above, the wave surface measuring device according to the first embodiment includes a heat exchanger 25 having an uneven surface and exhausting the heat exchanged. The heat radiating portion 14C is an uneven surface in which a surface not facing the optical axis a is combined with an uneven surface of the heat exchanger 25. By having this configuration, the wave surface measuring device can accurately exhaust the heat from the input / output unit 10 and the control circuit 12.

It should be noted that the present invention is not limited to the above-described embodiment, and within the scope of the present invention, any combination of the embodiments or any component of the embodiment may be modified or the embodiment. Any component can be omitted in each of the above.

Since the wave surface measuring device according to the present invention can measure the wave surface even in an environment where the pressure is sufficiently reduced from the atmospheric pressure, it can be used, for example, for evaluating the optical system of an astronomical telescope.

1,1A, 1B, 1C, 1a, 1b Main body, 2 subject, 3 vacuum container, 4 exhaust device, 5 input / output terminal, 6 calculation device, 6a calculation unit, 6b power supply unit, 6c cutoff unit, 6d temperature storage Unit, 7 light source, 8 optical fiber, 9 barometer, 10 input / output unit, 11, 11a, 11b temperature measurement unit, 12 control circuit, 13 bonding unit, 14, 14A, 14B, 14C heat dissipation unit, 15, 15A, 15A1 , 15B housing, 15a opening, 16 cushioning part, 17 wave surface dividing part, 18 light receiving part, 18a, 18b point image, 18a1, 18b1 wave surface, 19 optical path dividing part, 20 collimating lens, 21 focus adjustment lens, 22 translation mechanism , 23 Calibration prototype, 24 Optical path switching part, 25 Heat exchanger, 26 Hot bath.

Claims (7)

A wave surface dividing part that spatially divides the luminous flux from the subject,
A light receiving part that receives a plurality of light fluxes divided by the wave surface dividing part,
A focus adjustment lens that guides the luminous flux from the subject to the light receiving portion through the wave surface dividing portion.
A control circuit that controls the light receiving unit and
An input / output unit that outputs a signal acquired from the light receiving unit by the control circuit to the outside and inputs information to the control circuit.
A housing that houses the wave surface dividing portion, the light receiving portion, the focus adjusting lens, the control circuit, and the input / output portion.
The control circuit and the input / output unit are thermally connected to one surface, the other surface has a plate shape of black, and the focus is directed toward the inside of the housing. Heat radiation is arranged at a position away from the optical axis of the light flux guided from the subject to the light receiving portion by the adjusting lens, and heat from the control circuit and the input / output portion is released to the outside of the housing by heat radiation. A wave surface measuring device characterized by having a part. A shock absorber provided in the housing to reduce stress from the heat dissipation portion is provided.
The wave surface measuring device according to claim 1, wherein the heat radiating portion is arranged with a gap between the heat radiating portion and the housing via the buffering portion. The wave surface measuring device according to claim 1, further comprising a translation mechanism for translating the focus adjusting lens along the optical axis. A calibration prototype that reflects the incident luminous flux,
An optical path switching unit for inserting and removing the calibration prototype in and out of the optical path between the focus adjustment lens and the subject is provided.
The focus adjusting lens guides a light beam reflected from the calibration prototype arranged in the optical path between the light receiving portion and the subject by the optical path switching portion to the light receiving portion through the wave surface dividing portion. The wave surface measuring device according to any one of claims 1 to 3, wherein the wave surface measuring device is characterized. A temperature measuring unit that measures the temperature of any of the light receiving unit, the control circuit, the input / output unit, the housing, and the heat radiating unit .
The claim is characterized in that it includes a blocking unit that cuts off the power supply to the control circuit based on either the temperature measured by the temperature measuring unit or the time during which power is supplied to the control circuit. The wave surface measuring device according to any one of claims 1 to 3. The wave surface measuring device according to claim 2, wherein the heat radiating portion is arranged on a portion of the housing on the back surface side of the light receiving portion. Equipped with a heat exchanger that has an uneven surface and exhausts the heat exchanged.
The wave surface measuring device according to claim 1, wherein the heat radiating portion is an uneven surface in which the other surface is combined with the uneven surface of the heat exchanger.

Images