JP2013076806A - Optical element and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve performance of an optical element.SOLUTION: An optical element 1 has a container 2 having a space 8 formed therein. The container 2 is provided with a light transmissive film member 3, which partitions the space 8 inside of the container 2 into a first space 9 and a second space 10. The first space 9 is filled with a first medium 5. The second space 10 is filled with a second medium 6 having a refractive index different from that of the first medium 5. Furthermore, the optical element 1 has a differential pressure generating unit 7 that generates differential pressure between the first space 9 and the second space 10. A focal point distance of the light that passes through the film member 3 can be changed by warping the film member 3 by means of the differential pressure generated by the differential pressure generating unit 7. In addition, the elastic modulus of the film member 3 is distributed to form concentric circles with the center at the optical axis OA of the light that passes through the film member 3.

Description

  The present invention relates to an optical element and a manufacturing method thereof, and more particularly to an optical element composed of a variable focus lens and a technique effective when applied to the manufacturing method thereof.

  In the manufacturing process of FPD (Flat Panel Display) such as liquid crystal and plasma, so-called TAB (Tape) such as mounting IC (Integrated Circuit), COF (Chip On Film), FPC (Flexible Printed Circuits) around the display substrate. A plurality of processing work steps for performing connection of Automated Rounding and mounting of a peripheral board (PCB: Printed Circuit Board) are sequentially performed. Various shape detection steps for detecting the shape of the display substrate are performed along with the plurality of processing operation steps. For example, after an ACF process for attaching an anisotropic conductive film (ACF) to a display substrate is performed, the shape of the substrate alignment mark is detected and aligned in order to inspect the attachment state of the ACF. A shape detection step is performed.

  Alternatively, an inspection process for inspecting a pattern formed on a printed circuit board, a printed circuit board manufacturing mask, a semiconductor integrated circuit wafer, a semiconductor integrated circuit manufacturing mask, or the like at a high speed is performed by the pattern inspection apparatus. In such an inspection process, for example, when performing an appearance inspection of a photomask for manufacturing a semiconductor integrated circuit, an image signal obtained by imaging an inspection target pattern on the photomask is compared with reference pattern data. A shape detection step for performing defect determination processing is performed.

  In such a shape detection step, an optical shape detection mechanism is used. The shape detection mechanism holds an object to be detected on the stage and detects the shape of the object to be detected held by a detector. An objective lens and an imaging system lens are provided between the object to be detected and the detector.

  In the optical shape detection mechanism, in order to cope with a change in the height position of the object to be detected, for example, the focusing is performed by moving the position of the imaging system lens. For this reason, in the optical shape detection mechanism, a mechanical movement mechanism for mechanically moving the position of the imaging lens is indispensable. In such a mechanical movement mechanism, there is a problem that it takes time to form a focal point in order to move a heavy member, that is, a member having a large inertia.

  On the other hand, two kinds of liquids with different refractive indexes are filled in a minute hole in a separated state, and the pressure of one of the liquids is changed to deform so that the interface between the two kinds of liquids is bent into a spherical shape. Thus, there is a technique for an optical element composed of a variable focus lens that obtains a lens effect. As an optical element composed of a variable focus lens, for example, the following techniques are known.

  In JP-A-2008-152090 (Patent Document 1), a first fluid and a second fluid immiscible such as water and oil are enclosed in a casing, and the first fluid and the second fluid are sealed. Describes the technology of an optical element composed of a variable focus lens that changes the focal length by changing the shape of the interface defined by.

  In JP-A-6-308303 (Patent Document 2), a transparent liquid is sealed between two transparent elastic films, and the curvature of the two transparent elastic films is changed by controlling the pressure of the liquid. The technology of an optical element composed of a variable focus lens for changing the focal length is described.

  When changing the pressure of a fluid such as a liquid, it is possible to respond faster than when the position of the imaging lens is moved by a mechanical movement mechanism. The time until formation can be shortened.

JP 2008-152090 A JP-A-6-308303

  According to the study of the present inventor, the following has been found.

  The shape of the interface between the first fluid and the second fluid is only defined by a difference in physical or chemical properties such as a difference in hydrophilicity or a difference in specific gravity. Therefore, as a result of the investigation by the present inventors, it has been found that the shape of the interface between the first fluid and the second fluid tends to be a spherical shape (spherical shape).

  When the shape of the interface becomes a spherical shape, the focal position of light transmitted through a portion (peripheral portion) far from the optical axis of the interface deviates from the focal position of light transmitted through a portion (center portion) close to the optical axis of the interface, A so-called spherical aberration occurs due to the occurrence of blurring or the like in the imaging of the light transmitted through the interface.

  Further, in the method of controlling the deformation shape of the transparent elastic film to an aspheric shape (aspheric shape) by giving a film thickness distribution by grinding or the like described in Patent Document 2, the first fluid and the The shape of the interface with the second fluid cannot be controlled to an aspherical shape. Thus, spherical aberration in an optical element composed of a variable focus lens having the lens surface as the interface between the first fluid and the second fluid cannot be suppressed, and the performance of the optical element may be degraded.

  An object of the present invention is to provide a technique capable of improving the performance of an optical element.

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  Of the inventions disclosed in the present application, the outline of typical ones will be briefly described as follows.

  The optical element according to the representative embodiment is a variable focus lens capable of changing the focal length of transmitted light. The optical element has a container in which a space is formed. The container is provided with a light-transmissive film member that partitions the space inside the container into a first space and a second space. The first space is filled with the first medium. The second space is filled with a second medium having a refractive index different from that of the first medium. The optical element also includes a differential pressure generating unit that generates a differential pressure between the first space and the second space. The focal length of the light transmitted through the film member can be changed by bending the film member with the differential pressure generated by the differential pressure generator. The distribution of the elastic modulus of the film member is a concentric distribution centering on the optical axis of the light transmitted through the film member.

  In addition, the optical element manufacturing method according to the representative embodiment is an optical element manufacturing method including a variable focus lens in which a focal length of transmitted light can be changed. The optical element has a container in which a space is formed. The container is provided with a light-transmissive film member that partitions the space inside the container into a first space and a second space. The first space is filled with the first medium. The second space is filled with a second medium having a refractive index different from that of the first medium. The optical element also includes a differential pressure generating unit that generates a differential pressure between the first space and the second space. The focal length of the light transmitted through the film member can be changed by bending the film member with the differential pressure generated by the differential pressure generator. In such an optical element manufacturing method, a container having a space formed therein is prepared. In addition, a film member capable of transmitting light is prepared. Next, a membrane member is attached to the container so that the space inside the container is divided into the first space and the second space, the first space is filled with the first medium, and the second space is filled with the second space. 2 medium is filled. The distribution of the elastic modulus of the film member is a concentric distribution centering on the optical axis of the light transmitted through the film member.

  In addition, the optical element manufacturing method according to the representative embodiment is an optical element manufacturing method including a variable focus lens in which a focal length of transmitted light can be changed. The optical element has a container in which a space is formed. The container is provided with a light-transmissive film member that partitions the space inside the container into a first space and a second space. The first space is filled with the first medium. The second space is filled with a second medium having a refractive index different from that of the first medium. The optical element also includes a differential pressure generating unit that generates a differential pressure between the first space and the second space. The focal length of the light transmitted through the film member can be changed by bending the film member with the differential pressure generated by the differential pressure generator. In such an optical element manufacturing method, a container having a space formed therein is prepared. In addition, a film member capable of transmitting light is prepared. Next, a membrane member is attached to the container so that the space inside the container is divided into the first space and the second space, the first space is filled with the first medium, and the second space is filled with the second space. 2 medium is filled. The film member has an axisymmetric shape about the optical axis of light transmitted through the film member, and has an aspherical shape.

  Among the inventions disclosed in the present application, effects obtained by typical ones will be briefly described as follows.

  According to the representative embodiment, the performance of the optical element can be improved.

2 is a cross-sectional view schematically showing the configuration of the optical element of Embodiment 1. FIG. 3 is an enlarged cross-sectional view schematically showing a state of a film member of the optical element according to Embodiment 1. FIG. 3 is an enlarged cross-sectional view schematically showing a state of a film member of the optical element according to Embodiment 1. FIG. 6 is an enlarged top view schematically showing a state of elastic modulus distribution of a film member of the optical element according to Embodiment 1. FIG. FIG. 3 is an enlarged cross-sectional view schematically showing a state where the film member of the optical element according to Embodiment 1 is bent. 3 is an enlarged cross-sectional view schematically showing a configuration of a film member of the optical element according to Embodiment 1. FIG. It is sectional drawing which shows typically the state of the optical element of Embodiment 1 when the differential pressure | voltage has generate | occur | produced between 1st space and 2nd space. It is sectional drawing which shows typically the state of the optical element of Embodiment 1 when the differential pressure | voltage has generate | occur | produced between 1st space and 2nd space. FIG. 6 is a manufacturing process flow chart showing a part of the manufacturing process of the optical element according to the first embodiment. It is a figure for demonstrating an example of the preparation process of a film | membrane member. FIG. 6 is a cross-sectional view during the manufacturing process of the optical element according to Embodiment 1. FIG. 6 is a cross-sectional view during the manufacturing process of the optical element according to Embodiment 1. FIG. 6 is a cross-sectional view during the manufacturing process of the optical element according to Embodiment 1. FIG. 6 is a cross-sectional view during the manufacturing process of the optical element according to Embodiment 1. FIG. 6 is a cross-sectional view during the manufacturing process of the optical element according to Embodiment 1. FIG. 6 is a cross-sectional view during the manufacturing process of the optical element according to Embodiment 1. FIG. 6 is a cross-sectional view during the manufacturing process of the optical element according to Embodiment 1. FIG. 6 is a cross-sectional view during the manufacturing process of the optical element according to Embodiment 1. It is sectional drawing which shows typically the structure of the optical element of the comparative example in which the film | membrane member is not provided between the 1st fluid and the 2nd fluid. It is sectional drawing which shows typically the state of the optical element of a comparative example when the differential pressure | voltage has generate | occur | produced between 1st space and 2nd space. It is sectional drawing which shows typically the state of the optical element of a comparative example when the differential pressure | voltage has generate | occur | produced between 1st space and 2nd space. It is a figure which shows typically the state of light refraction in the optical element of the comparative example whose shape of the interface of the 1st fluid and the 2nd fluid is a spherical shape. In the optical element of a comparative example, it is sectional drawing which shows typically an example of the state where the shape of the interface of the 1st fluid and the 2nd fluid is disturb | confused. It is a figure which shows typically the state of refraction of light in the optical element of Embodiment 1 whose shape of the interface between the first fluid and the second fluid is an aspherical shape. FIG. 6 is a diagram schematically showing a configuration of a shape detection mechanism of a second embodiment. It is a figure which shows typically the structure of the display board module assembly line in which the test | inspection unit which is a shape test | inspection apparatus of Embodiment 2 was integrated. It is a figure which shows typically the principal part centering on an ACF sticking state inspection unit among the display board module assembly lines of Embodiment 2. FIG. It is the figure which showed the display substrate which is a main part required for a test | inspection among the structures shown in FIG. 27, and a test object. It is a figure explaining the method which can test | inspect various ACF sticking states efficiently in the shape inspection apparatus of Embodiment 2. FIG. It is a processing flowchart which shows the test | inspection operation | movement of an ACF sticking state test | inspection. FIG. 10 is a block diagram of a pattern inspection apparatus that is a shape inspection apparatus according to a third embodiment. It is explanatory drawing of the two-dimensional pattern scanning of the pattern inspection apparatus which is a shape inspection apparatus of Embodiment 3. FIG. It is explanatory drawing of the two-dimensional pattern scanning of the pattern inspection apparatus which is a shape inspection apparatus of Embodiment 3. FIG. FIG. 10 is a block diagram of a defect candidate detection unit of a pattern inspection apparatus that is a shape inspection apparatus according to a third embodiment.

  In the following embodiments, when it is necessary for the sake of convenience, the description will be divided into a plurality of sections or embodiments. However, unless otherwise specified, they are not irrelevant to each other. There are some or all of the modifications, details, supplementary explanations, and the like. Further, in the following embodiments, when referring to the number of elements (including the number, numerical value, quantity, range, etc.), especially when clearly indicated and when clearly limited to a specific number in principle, etc. Except, it is not limited to the specific number, and may be more or less than the specific number. Further, in the following embodiments, the constituent elements (including element steps and the like) are not necessarily indispensable unless otherwise specified and apparently essential in principle. Needless to say. Similarly, in the following embodiments, when referring to the shapes, positional relationships, etc. of the components, etc., the shapes are substantially the same unless otherwise specified, or otherwise apparent in principle. And the like are included. The same applies to the above numerical values and ranges.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiments, and the repetitive description thereof will be omitted. In the following embodiments, the description of the same or similar parts will not be repeated in principle unless particularly necessary.

  In the drawings used in the embodiments, hatching may be omitted even in a cross-sectional view so as to make the drawings easy to see. Further, even a plan view may be hatched to make the drawing easy to see.

(Embodiment 1)
<Optical element>
An optical element according to an embodiment of the present invention will be described with reference to the drawings. The optical element of the present embodiment is a variable focus lens whose focal length can be changed.

  FIG. 1 is a cross-sectional view schematically showing the configuration of the optical element according to Embodiment 1. 2 and 3 are enlarged cross-sectional views schematically showing the state of the film member of the optical element of the first embodiment. FIG. 2 shows a state in which no differential pressure is generated between the first space and the second space, and FIG. 3 shows a state in which a differential pressure is generated between the first space and the second space. It shows the state.

  FIG. 4 is an enlarged top view schematically showing a state of elastic modulus distribution of the film member of the optical element according to the first embodiment. FIG. 5 is an enlarged cross-sectional view schematically showing a state in which the film member of the optical element of Embodiment 1 is bent. FIG. 6 is an enlarged cross-sectional view schematically showing the configuration of the film member of the optical element of the first embodiment. 5 and 6, the aspect ratio is changed and the vertical direction is enlarged compared to the horizontal direction in order to make the drawings easy to see.

  7 and 8 are cross-sectional views schematically showing the state of the optical element according to Embodiment 1 when a differential pressure is generated between the first space and the second space. FIG. 7 shows a state where the differential pressure of the first space with respect to the second space is a positive pressure, and FIG. 8 shows a state where the differential pressure of the first space with respect to the second space is a negative pressure.

  As shown in FIG. 1, the optical element 1 includes a container 2, a membrane member 3, a first fluid 5, a second fluid 6, and a differential pressure generator 7.

  A space 8 is formed inside the container 2. The membrane member 3 is provided so as to partition the space 8 into a first space 9 and a second space 10 and is made of a material that can transmit light (for example, visible light). The first space 9 is filled with the first fluid 5, and the second space 10 is filled with the second fluid 6. Therefore, the first fluid 5 and the second fluid 6 are in contact via the membrane member 3. The membrane member 3 is attached by bonding the peripheral portion of the membrane member 3 to the inner wall of the space 8 with an adhesive, for example. The differential pressure generator 7 generates a differential pressure (pressure difference) between the first space 9 and the second space 10. Details of the differential pressure generator 7 will be described later.

  The first fluid 5 and the second fluid 6 can transmit light (for example, visible light) and have different refractive indexes. Because the refractive index difference between the first fluid 5 and the second fluid 6 causes light to be refracted at the interface between the first fluid 5 and the second fluid 6, that is, the film member 3. Light can be focused at a position away from a predetermined distance (substantially equal to the focal length). As described above, the differential pressure generator 7 generates a differential pressure (pressure difference) between the first space 9 and the second space 10, thereby bending the membrane member 3 and projecting upward. Or can be deformed into a convex shape. Therefore, the shape of the interface between the first fluid 5 and the second fluid 6 can be changed, and the focal length of the light transmitted through the film member 3 can be changed. In this way, the optical element 1 functions as a variable focus lens whose focal length can be changed.

  In addition, the optical axis of the light which permeate | transmits the film | membrane member 3 is set to OA. Further, as the refractive index, a refractive index obtained by measurement with sodium D-line (wavelength: 589.3 nm) can be used. Hereinafter, the refractive index n means the refractive index of sodium at the D-line.

  The shape of the first space 9 and the shape of the second space 10 in the vicinity of the membrane member 3 are cylindrical. That is, the cross-sectional shape perpendicular to the optical axis OA of the first space 9 and the cross-sectional shape perpendicular to the optical axis OA of the second space 10 in the vicinity of the film member 3 are circular. Further, as will be described later with reference to FIG. 4, the elastic modulus distribution of the film member 3 is a concentric distribution centering on the optical axis OA of the light transmitted through the film member 3. Therefore, the elastic modulus distribution of the membrane member 3 is also a concentric distribution centering on the central axis of the first space 9 having a cylindrical shape and the central axis of the second space 10 having a cylindrical shape. Is preferred. That is, it is preferable that the optical axis OA of the light transmitted through the film member 3 coincides with the central axes of the first space 9 and the second space 10 in the vicinity of the film member 3. Thereby, in the optical element 1, it becomes easy to obtain the optically axisymmetric property required as a variable focus lens.

  The container 2 includes a first container member 11 in which a first space 9 is formed, and a second container member 12 in which a second space 10 is formed. It is preferable that the first container member 12 and the second container member 12 are stacked. With such a structure, the first fluid 5 and the second fluid 6 can be easily filled in the container 2 as will be described later in the description of the manufacturing process of the optical element. Hereinafter, the case where the container 2 includes the first container member 11 and the second container member 12 will be described as an example. However, the container 2 may be prepared as an integral member from the beginning.

  The first container member 11 is preferably formed with a first opening 13 so as to penetrate from the main surface 11a to the opposite surface 11b of the main surface 11a, and the second container member 12 has the main surface It is preferable that the 2nd opening part 14 is formed so that it may penetrate from 12a to the opposite surface 12b of the main surface 12a. Moreover, it is preferable that the 1st sealing member 15 is attached to the 1st container member 11 so that the opposite surface 11b side of the 1st opening part 13 may be sealed, and the 2nd container member 12, the second sealing member 16 is preferably attached so as to seal the main surface 12a side of the second opening 14. With such a structure, the first fluid 5 and the second fluid 6 can be easily filled in the container 2 as will be described later in the description of the manufacturing process of the optical element. Hereinafter, the first opening 13 is formed in the first container member 11, the second opening 14 is formed in the second container member 12, and the opposite surface 11 b of the first opening 13. The case where the side is sealed with the first sealing member 15 and the main surface 12a side of the second opening 14 is sealed with the second sealing member 16 will be described as an example. However, as for the 1st container member 11, the 1st opening part 13 currently formed in the main surface 11a does not penetrate to the opposite surface 11b, but the part of the bottom part of the 1st opening part 13, ie, the opposite surface 11b side. However, it may be made of a material capable of transmitting light. Further, in the second container member 12, the second opening 14 formed on the opposite surface 12b does not penetrate to the main surface 12a, and the bottom of the second opening 14, that is, the portion on the main surface 12a side. However, it may be made of a material capable of transmitting light.

  Further, when the film member 3 is bent by making the pressure of the first space 9 higher than the pressure of the second space 10 and deformed into an upwardly convex shape, it is used as a variable focus lens. 2, it is preferable that the peripheral portion 4 of the membrane member 3 is attached to the opposite surface 12b of the second container member 12 by, for example, bonding with an adhesive. Thereby, when the membrane member 3 is bent and deformed, as shown in FIG. 3, the peripheral portion 4 is further pressed against the attached side (the second container member 12 side). Can be prevented from peeling off from the opposite surface 12 b of the second container member 12.

  The first container member 11 and the second container member 12 are bonded to the main surface 11a of the first container member 11 and the opposite surface 12b of the second container member 12 by an adhesive (not shown). It may be what was done. Alternatively, the first container member 11, the second container member 12, and the O-ring are sandwiched between the main surface 11 a of the first container member 11 and the opposite surface 12 b of the second container member 12. However, it may be tightened so as to be crimped by a bolt and a nut (not shown).

  As the 1st container member 11, the 2nd container member 12, the 1st sealing member 15, and the 2nd sealing member 16, glass, transparent resin, etc. can be used, for example. Further, as the transparent resin, for example, polymethyl methacrylate (PMMA), polycarbonate (PC), polystyrene (PS), styrene-acrylonitrile resin (SAN resin), methyl methacrylate-styrene resin (MS resin) and the like can be used.

  The first fluid 5 and the second fluid 6 may have different refractive indexes n and at least one of them may contain a liquid component, and the other may be liquid even if it is a gas. Also good. In addition, as the first fluid 5 and the second fluid 6, for example, those containing various media including a gel material (the first medium 5 and the second medium 6) can be used. For example, water (n = 1.33) can be used as one of the first fluid 5 and the second fluid 6 (fluid having a low refractive index), and the other fluid (having a high refractive index). For example, silicone oil such as polydimethylsiloxane (PDMS) (n = 1.41) can be used as the fluid.

  Moreover, it is preferable that the 1st fluid 5 and the 2nd fluid 6 are adjusted so that specific gravity may become substantially equal by adding an additive. As a result, when the optical element 1 is tilted by a small angle due to an impact or vibration, the shape of the interface between the first fluid 5 and the second fluid 6 is the optical axis of light transmitted through the interface. It is possible to prevent disturbance from an axisymmetric shape centering on OA. When water (specific gravity 1) is used as the fluid, for example, alkali metal salts such as sodium chloride, potassium chloride, magnesium chloride, calcium chloride, or alkaline earth metal salts can be used as additives. Moreover, when using PDMS (specific gravity 0.91-1.0) as a fluid, a paraffin can be used as an additive, for example.

  The material of the film member 3 is not particularly limited as long as it is a resin that can transmit light and is insoluble in both the first fluid 5 and the second fluid 6. Therefore, for example, a silicone resin can be used as the material of the membrane member 3.

  As shown in FIG. 4, in the present embodiment, the elastic modulus distribution of the film member 3 is a concentric distribution centering on the optical axis OA of the light transmitted through the film member 3. In FIG. 4, for example, a distribution in which the elastic modulus is smaller (softer) toward the center 3a side closer to the optical axis OA and larger (harder) toward the peripheral portion 3b farther from the optical axis OA is represented. When pressure is uniformly applied to the film member 3 having such a distribution of elastic modulus in a direction perpendicular to the paper surface of FIG. 4, that is, a direction parallel to the optical axis OA, in the paper surface of FIG. Since the center part 3a side of the member 3 tends to extend in a direction perpendicular to the paper surface of FIG. 4, the shape of the film member 3 is an aspherical shape such as a bullet shape as shown in FIG. Then, by appropriately setting the distribution of the concentric elastic modulus, when the differential pressure (pressure difference) is generated by the differential pressure generator 7, the shape of the membrane member 3 is changed to a paraboloid, a hyperboloid, It can be deformed into an arbitrary shape out of an aspherical surface composed of an elliptical surface and a curved surface represented by a higher order polynomial such as a quartic surface. The aspherical shape means a curved shape that is not a planar shape and is not a spherical shape.

  The elastic modulus in this embodiment means a general term for proportional constants between stress and strain, and is a concept including Young's modulus (longitudinal elastic modulus), rigidity modulus, bulk elastic modulus, and the like. That is, the elastic modulus distribution of the membrane member 3 may be any proportional constant distribution.

  As the film member 3 having such a concentric distribution of elastic modulus, as shown in FIG. 5, for example, a base material 3c and an adjustment for adjusting the elastic modulus of the film member 3 included in the base material 3c. The member 3d is included in the base material 3c so that the distribution of the content of the adjusting member 3d included in the base material 3c is a concentric distribution centering on the optical axis OA. Is mentioned. As the base material 3c, for example, a silicone resin as described above as the material of the film member 3 can be used. Further, as the adjustment member 3d, a resin having a larger elastic modulus than that of the base material 3c, for example, a fluororesin can be used. When the elastic modulus of the adjusting member 3d is larger than the elastic modulus of the base material 3c, the content of the adjusting member 3d is decreased toward the central portion 3a closer to the optical axis OA and adjusted toward the peripheral portion 3b farther from the optical axis OA. By increasing the content ratio of the member 3d, the elastic modulus is smaller (softer) toward the center 3a side closer to the optical axis OA as shown in FIG. 4, and the elastic modulus is closer to the peripheral part 3b side farther from the optical axis OA. A large (hard) distribution can be obtained.

  Note that FIG. 5 shows a state in which the adjustment member 3d is contained in the base material 3c as particles for easy viewing of the drawing, but the adjustment member 3d is mixed with the base material 3c and integrated with the base material 3c. It may be contained in a liquefied state.

  Further, as will be described later in the description of the manufacturing process of the optical element 1, for example, the photocurable resin capable of controlling the elastic modulus after curing is irradiated by light intensity to cure the photocurable resin. Thus, the film member 3 is formed, and the intensity distribution of the irradiated light can be a concentric distribution centering on the optical axis OA. As shown in FIG. 4, by reducing the intensity of light irradiated toward the center 3a side closer to the optical axis OA and increasing the intensity of light irradiated toward the peripheral part 3b far from the optical axis OA, It is possible to obtain a distribution of elastic modulus having a smaller elastic modulus (softer) toward the central portion 3a closer to the optical axis OA and a larger (harder) elastic modulus toward the peripheral portion 3b farther from the optical axis OA.

  The distribution of the elastic modulus of the film member 3 is a concentric distribution with the optical axis OA as the center, and the radial component of the elastic modulus and the circumferential component of the elastic modulus are different. Good. If the radial component of the elastic modulus and the circumferential component of the elastic modulus are different, the differential pressure generator 7 generates a differential pressure (pressure difference) by appropriately setting the distribution of each component. The shape of the membrane member 3 is deformed into an arbitrary shape out of the aspherical surface composed of a parabolic surface, a hyperbolic surface, an elliptical surface, and a curved surface represented by a high-order polynomial such as a quartic surface. Can be made.

  Alternatively, instead of the membrane member 3 described with reference to FIG. 4, as shown in FIG. 6, the shape is axisymmetric about the optical axis OA of the light transmitted through the membrane member 3 and differential pressure is generated. The film member 3e having an aspherical shape even when no differential pressure is generated by the portion 7, that is, having an aspherical shape from the beginning may be used. FIG. 6 shows a membrane member 3e having a shell shape as an example. If the film member 3e having an aspherical shape is used from the beginning, even when pressure is uniformly applied to the film member 3e in a direction parallel to the optical axis OA in a plane perpendicular to the optical axis OA, The shape of the film member 3e is an aspherical shape. Then, by appropriately setting the initial shape of the membrane member 3e, even when the differential pressure is generated by the differential pressure generating unit 7, the shape of the membrane member 3e is changed to a paraboloid, a hyperboloid, an ellipsoid, and It can be deformed into an arbitrary shape among aspherical shapes made of a curved surface represented by a high-order polynomial such as a quartic curved surface.

  As the film member 3e having such an aspherical shape, for example, a base material made of a resin that can be plastically deformed at a temperature higher than room temperature is pressed against a mold member that is held at a temperature at which the base material can be plastically deformed. After plastic deformation, it can be formed by cooling to room temperature.

  In the following description of the optical element, only the case of having the film member 3 will be described, but the same applies to the case of having the film member 3e.

  The thickness of the film member 3 is preferably, for example, 1 to 1000 μm, although it depends on the elastic modulus such as Young's modulus and the refractive index of the film member 3. This is because if the thickness of the membrane member 3 is less than 1 μm, it is difficult to ensure the strength of the membrane member 3 itself. When the thickness of the membrane member 3 exceeds 1000 μm, the light is refracted at the interface between the first fluid 5 and the membrane member 3 or the interface between the second fluid 6 and the membrane member 3, and the first This is because refraction at the interface between the fluid 5 and the second fluid 6 becomes complicated.

  In addition, the refractive index of the film member 3 is preferably equal to the refractive index of one of the first fluid 5 and the second fluid 6. Thereby, since light does not refract between the membrane member 3 and one of the first fluid 5 and the second fluid 6, one of the first fluid 5 and the second fluid 6 and the membrane member This is because 3 can behave optically and integrally. For example, when PDMS is used as one of the first fluid 5 and the second fluid 6, PDMS can also be used as the membrane member 3. This is because PDMS can be used as a liquid, but can be solidified, for example, by adding a gelling agent, and the film member 3 can be easily formed.

  In the present embodiment, the first fluid 5 and the second fluid 6 are in contact via the membrane member 3. Therefore, there is no restriction of selecting materials immiscible with each other such that one of the first fluid 5 and the second fluid 6 is oil-based liquid and the other is water-based liquid. There is an advantage that the degree spreads.

  The optical element 1 includes a first pressure adjusting unit 21 as the differential pressure generating unit 7. The first pressure adjusting unit 21 adjusts the pressure of the first space 9 by displacing the wall surface of the first space 9 in a direction intersecting the wall surface. An actuator 23 can be used as the first pressure adjustment unit 21. Moreover, the diaphragm 24 can be used as the wall surface of the first space 9 that is displaced by the actuator 23. At this time, the actuator 23 displaces the diaphragm 24 to decrease or increase the volume of the first space 9 so that the pressure in the first space 9 becomes larger or smaller than the pressure in the second space 10. Adjust so that For example, as illustrated in FIG. 1, the diaphragm 24 is provided on the lower surface (opposite surface 11 b side) of the space 25 that extends laterally from the first space 9 and communicates with the first space 9. be able to. At this time, the actuator 23 can be provided in contact with the lower side (opposite surface 11 b side) of the diaphragm 24. As the actuator 23, for example, a piezoelectric element (piezoelectric element) that can be expanded and contracted by applying a voltage can be used.

  When the piezoelectric element 23 and the diaphragm 24 are arranged as described above, for example, by applying a voltage so that the piezoelectric element 23 extends in the vertical direction (thickness direction) and contracts in the horizontal direction (in-plane direction), the diaphragm 24 is bent so as to have a convex shape upward, and the volume of the first space 9 is reduced. Accordingly, the pressure in the first space 9 with respect to the pressure in the second space 10 can be increased, and the differential pressure (pressure difference) in the first space 9 with respect to the second space 10 can be made positive. . Due to this differential pressure, the membrane member 3 bends so as to have a convex shape as shown in FIG. That is, due to the differential pressure generated by the piezo element 23, the shape of the interface between the first fluid 5 and the second fluid 6 is deformed so as to be convex upward. And the focal distance of the light which permeate | transmits the film | membrane member 3 can be changed by adjusting the voltage applied to the piezoelectric element 23, and adjusting the deformation amount of the shape of an interface. Further, as described above, since the elastic modulus distribution of the film member 3 is a concentric distribution centering on the optical axis OA, the shape of the interface (the shape of the film member 3) can be an aspherical shape. Further, it is possible to suppress the occurrence of blurring in the light image formation due to spherical aberration.

  On the other hand, for example, by applying a voltage so that the piezo element 23 contracts in the vertical direction (thickness direction) and extends in the left-right direction (in-plane direction), the diaphragm 24 is bent into a downwardly convex shape, The volume of the first space 9 is increased. Accordingly, the pressure in the first space 9 with respect to the pressure in the second space 10 can be reduced, and the differential pressure (pressure difference) in the first space 9 with respect to the second space 10 can be made negative. . By this differential pressure, the membrane member 3 is bent so as to have a downwardly convex shape as shown in FIG. That is, due to the differential pressure generated by the piezo element 23, the shape of the interface between the first fluid 5 and the second fluid 6 is deformed so as to be convex downward. And the focal distance of the light which permeate | transmits the film | membrane member 3 can be changed by adjusting the voltage applied to the piezoelectric element 23, and adjusting the deformation amount of the shape of an interface. Further, as described above, since the elastic modulus distribution of the film member 3 is a concentric distribution centering on the optical axis OA, the shape of the interface (the shape of the film member 3) can be an aspherical shape. Further, it is possible to suppress the occurrence of blurring in the light image formation due to spherical aberration.

  The optical element 1 is preferably provided with a buffer tank (air reservoir) 31. The buffer tank 31 is provided outside the container 2 including the first container member 11 and the second container member 12. The interior of the buffer tank 31 communicates with the second space 10 via an orifice (orifice portion) 32. The second space 10 and the portion of the orifice 32 that is partway from the end 32a on the second space 10 side toward the buffer tank 31, that is, the portion of the orifice 32 on the second space 10 side, Filled with a second fluid 6. On the other hand, the buffer tank 31 and the portion of the orifice 32 that extends from the end 32b on the buffer tank 31 side to the middle of the second space 10, that is, the portion of the orifice 32 on the buffer tank 31 side are the second. The fluid 6 is not filled. Since the second space 10 communicates with the buffer tank 31, the above-described differential pressure becomes a positive pressure, the membrane member 3 is bent so as to have a convex shape, and the volume of the second space 10 is increased. When decreased, the second fluid 6 can escape to the outside of the second space 10. In addition, since the second space 10 and the buffer tank 31 communicate with each other via the orifice 32, it is possible to prevent air from entering the second space 10 from the buffer tank 31 as bubbles. Accordingly, bubbles can be prevented from entering between the membrane member 3 and the second fluid 6 and in the second fluid 6 in the vicinity of the membrane member 3, and the shape of the membrane member 3 is 3 can be prevented from being disturbed from an axially symmetric shape with the optical axis OA of the light passing through 3 as the center.

  As shown in FIG. 7, when the membrane member 3 is bent so as to have a convex shape, the end surface 32c of the second fluid 6 filled in the orifice 32 on the buffer tank 31 side is Compared to the case where the pressure in the first space 9 and the pressure in the second space 10 are equal (when shown in FIG. 1), the first space 9 moves toward the buffer tank 31 side. Further, as shown in FIG. 8, when the membrane member 3 is bent so as to have a downwardly convex shape, the end surface 32c of the second fluid 6 has the pressure in the first space 9 and the second space. Compared to when the pressure of 10 is equal (when shown in FIG. 1), the second space 10 moves. Therefore, when the optical element 1 is used as a variable focus lens, the length of the orifice 32 is such that the end surface 32c of the second fluid 6 on the buffer tank 31 side is always located between the end portion 32a and the end portion 32b. Is decided.

  Furthermore, the optical element 1 preferably includes a second pressure adjusting unit 33 that adjusts the internal pressure of the buffer tank 31 as the differential pressure generating unit 7. As the second pressure adjusting unit 33, a pressure device composed of, for example, a pump and a pressure reducing device composed of, for example, a discharge valve, which are switchably connected via, for example, a three-way valve can be used. When the internal pressure of the buffer tank 31 is adjusted by the second pressure adjusting unit 33, the membrane member when the pressure in the first space 9 becomes a predetermined pressure by the first pressure adjusting unit 21 (actuator 23). The pressure in the second space 10 can be adjusted so that 3 has a predetermined shape. The focal length is adjusted by coarsely adjusting the shape of the membrane member 3 in advance by the second pressure adjusting unit 33 and then finely adjusting the shape of the membrane member 3 by the first pressure adjusting unit 21 (actuator 23). It can be changed in a wider range and with higher accuracy.

<Optical element manufacturing method>
Next, the manufacturing process of the optical element of this Embodiment is demonstrated with reference to drawings. FIG. 9 is a manufacturing process flow chart showing a part of the manufacturing process of the optical element of the first embodiment. FIG. 10 is a diagram for explaining an example of a membrane member preparation process. 11 to 18 are cross-sectional views of the optical element according to Embodiment 1 during the manufacturing process.

  The membrane member 3 described with reference to FIG. 4 is prepared in advance (step S0 in FIG. 9). However, the step of preparing the membrane member 3 may be performed at any stage as long as it is before step S4 described later.

  As the film member 3 having the above-described elastic modulus distribution, for example, the base material 3c described with reference to FIG. 5 and the adjustment member 3d included in the base material 3c for adjusting the elastic modulus of the film member 3 are provided. It can be used. At this time, in the step of preparing the film member 3, the distribution of the content of the adjustment member 3 d included in the base material 3 c is a concentric distribution centered on the optical axis OA of the light transmitted through the film member 3. In addition, it is possible to perform a step of including the adjusting member 3d in the base material 3c. When the elastic modulus of the adjusting member 3d is larger than the elastic modulus of the base material 3c, the content of the adjusting member 3d is decreased toward the central portion 3a closer to the optical axis OA and adjusted toward the peripheral portion 3b farther from the optical axis OA. By increasing the content ratio of the member 3d, the elastic modulus is smaller (softer) toward the center 3a side closer to the optical axis OA as shown in FIG. 4, and the elastic modulus is closer to the peripheral part 3b side farther from the optical axis OA. A large (hard) distribution can be obtained.

  Alternatively, in the step of preparing the film member 3 having the elastic modulus distribution described above, for example, light is irradiated to a photocurable resin capable of controlling the elastic modulus after curing by the intensity of the irradiated light, and photocurable. The step of forming the film member 3 can be performed by curing the resin. At this time, the intensity distribution of the irradiated light is made to be a concentric distribution centering on the optical axis OA. As shown in FIG. 4, by reducing the intensity of light irradiated toward the center 3a side closer to the optical axis OA and increasing the intensity of light irradiated toward the peripheral part 3b far from the optical axis OA, It is possible to obtain a distribution of elastic modulus having a smaller elastic modulus (softer) toward the central portion 3a closer to the optical axis OA and a larger (harder) elastic modulus toward the peripheral portion 3b farther from the optical axis OA.

  Alternatively, instead of the membrane member 3 having the elastic modulus distribution described above, a membrane member 3e (see FIG. 6) having an aspherical shape, for example, a bullet shape, can be used from the beginning. At this time, the process of preparing the film member 3e can be performed as shown in FIG. 10, for example. First, a mold member 3f having an axisymmetric shape and an aspherical shape (for example, a bullet shape) is prepared. Moreover, although it does not plastically deform at normal temperature, the base material 3g which consists of resin which can be plastically deformed at temperature higher than normal temperature is prepared. Then, after the mold member 3f is plastically deformed by pressing the substrate 3g against the mold member 3f in a state where the mold member 3f is at a temperature higher than normal temperature and the substrate 3g is held at a temperature at which plastic deformation is possible. The film member 3e is formed by cooling to room temperature.

  Next, as shown in FIG. 11, the first container member 11 is prepared (step S1 in FIG. 9). A first opening 13 is formed in the first container member 11 so as to penetrate from the main surface 11a to the surface 11b opposite to the main surface 11a. The opening shape of the first opening 13 in the main surface 11a is a circular shape. A diaphragm 24 is provided on the lower surface (opposite surface 11 b side) of the space 25 extending laterally from the first opening 13. An actuator 23 is provided so as to be in contact with the lower side of the diaphragm 24 (on the opposite surface 11b side). That is, the first container member 11 includes a step of providing the diaphragm 24 on the lower side (opposite surface 11b side) of the space 25 and a step of providing the actuator 23 on the lower side (opposite surface 11b side) of the diaphragm 24. Has already been done. However, the step of providing the diaphragm 24 on the lower side (opposite surface 11b side) of the space 25 and the step of providing the actuator 23 on the lower side (opposite surface 11b side) of the space 24 are described in step S5 described later. It may be performed at any stage as long as it is before.

  Next, as shown in FIG. 12, the second container member 12 is prepared (step S2 in FIG. 9). A second opening 14 is formed in the second container member 12 so as to penetrate from the main surface 12a to the surface 12b opposite to the main surface 12a. The opening shape of the second opening 14 on the opposite surface 12b is a circular shape. In addition, pores 34 are formed on the side surface of the second container member 12. Since the pore 34 communicates with the second opening 14, the second opening 14 opens on the side surface of the second container member 12 through the pore 34.

  Next, as shown in FIG. 13, the first sealing member 15 is attached to the first container member 11 (step S3 in FIG. 9). The 1st sealing member 15 is attached so that the opposite surface 11b side of the 1st opening part 13 may be sealed.

  Next, as shown in FIG. 14, the membrane member 3 is attached to the second container member 12 (step S4 in FIG. 9). The membrane member 3 is attached so as to seal the opposite surface 12b side of the second opening 14. At this time, the holding jig and the second container member 12 were determined in advance using a holding jig (not shown) having a center coinciding with the center of the concentric elastic modulus distribution described above. By aligning at the reference position, the optical axis OA of the light transmitted through the film member 3 and the center of the second opening portion 14 having a circular opening shape on the opposite surface 12b can be matched. Alternatively, when the membrane member 3e (see FIG. 6) is used instead of the membrane member 3, the axially symmetric mold member 3f (see FIG. 10) for forming the membrane member 3e having the above-described aspherical shape, for example, a bullet shape. ) Is used as a holding jig, and the mold member 3f and the second container member 12 are aligned at a predetermined reference position, so that it is opposite to the optical axis OA of the light transmitted through the film member 3e. You may make the center of the 2nd opening part 14 which has circular opening shape in the surface 12b correspond.

  In the following description of the optical element manufacturing method, only the case where the film member 3 is used will be described, but the same applies to the case where the film member 3e is used.

  Next, as shown in FIG. 15, the first fluid 5 is filled in the first opening 13 (step S5 in FIG. 9). In step S <b> 3, the opposite surface 11 b side of the first opening 13 is sealed with the first sealing member 15. Therefore, the first fluid 5 is filled in the first opening 13 whose opposite surface 11 b side is sealed by the first sealing member 15.

  Next, as shown in FIG. 16, the second container member 12 is attached to the first container member 11 (step S6 in FIG. 9). The second container member 12 is connected to the main surface 11a side of the first container member 11 so that the membrane member 3 seals the main surface 11a side of the first opening 13 filled with the first fluid 5. Attach to. That is, the container 2 is formed by attaching the second container member 12 to the first container member 11 so that the first container member 11 and the second container member 12 overlap each other. Thereby, the opposite surface 11 b side of the first opening 13 is sealed by the first sealing member 15, and the main surface 11 a side of the first opening 13 is sealed by the film member 3. A space 9 is formed. The first space 9 is filled with the first fluid 5.

  In step S6, the first container member 11 and the second container member 12 are aligned at a predetermined reference position, whereby the first opening portion having a circular opening shape on the main surface 11a. The center of 13 and the center of the second opening 14 having a circular opening shape on the opposite surface 12b can be matched. Thereby, the optical axis OA of the light transmitted through the film member 3 and the center of the first opening 13 having a circular opening shape on the main surface 11a can be matched.

  Next, as shown in FIG. 17, the orifice 32, the buffer tank 31, and the second pressure adjusting unit 33 are attached (step S7 in FIG. 9). The orifice tube 32d and the buffer tank 31 are attached to the second container member 12 so that the second opening 14 communicates with the inside of the buffer tank 31 through the orifice 32. Specifically, one end of the orifice pipe 32d is connected to the pore 34 in which the second opening 14 is open on the side surface of the second container member 12, and the buffer tank 31 is connected to the other end of the orifice pipe 32d. Connecting. The orifice pipe 32 d functions as the orifice 32 integrally with the pore 34. Then, the second pressure adjusting unit 33 is connected to the buffer tank 31.

  Next, as shown in FIG. 18, the second opening 14 is filled with the second fluid 6 (step S8 in FIG. 9). In step S <b> 6, the opposite surface 12 b side of the second opening 14 is sealed with the film member 3. Therefore, the second fluid 6 is filled in the second opening 14 whose opposite surface 12 b side is sealed by the membrane member 3. At this time, the second opening 14 and a portion of the orifice 32 that extends from the end 32 a on the second opening 14 side to the buffer tank 31, that is, the second opening 14 of the orifice 32. The second fluid 6 is filled so that the side portion is filled. For example, by making the internal pressure of the buffer tank 31 negative with respect to the atmospheric pressure by the second pressure adjustment unit 33, the orifice 32 and the end 32 a on the second opening 14 side toward the buffer tank 31. The second fluid 6 can be easily filled in the middle part.

  Next, the second sealing member 16 is attached to the second container member 12 (step S9 in FIG. 9). The second sealing member 16 is attached so as to seal the main surface 12a side of the second opening 14 filled with the second fluid 6. Thereby, the opposite surface 12 b side of the second opening 14 is sealed by the film member 3, and the main surface 12 a side of the second opening 14 is sealed by the second sealing member 16. The space 10 is formed. In addition, the second space 10 and the orifice 32 in the portion from the end 32a on the second space 10 side to the middle of the buffer tank 31, that is, the portion of the orifice 32 on the second space 10 side. Is filled with the second fluid 6. Note that the buffer tank 31 and the orifice 32 in the portion from the end 32b on the buffer tank 31 side to the middle of the second space 10, that is, the portion on the buffer tank 31 side of the orifice 32, The fluid 6 is not filled.

  Through the above steps, as shown in FIG. 1, an optical element composed of a variable focus lens can be easily and simply manufactured.

  However, as described above, the container 2 does not include the first container member 11 and the second container member 12 but may be prepared as an integral member from the beginning. At this time, the container 2 and the membrane member 3 are prepared, and the membrane member 3 is attached so that the space 8 inside the container 2 is divided into the first space 9 and the second space 10. The first fluid 5 may be filled and the second space 10 may be filled with the second fluid 6.

<Spherical aberration and disorder of interface shape>
FIG. 19 is a cross-sectional view schematically illustrating a configuration of an optical element of a comparative example in which a film member is not provided between the first fluid and the second fluid. 20 and 21 are cross-sectional views schematically showing the state of the optical element of the comparative example when a differential pressure is generated between the first space and the second space. FIG. 22 is a diagram schematically showing the state of light refraction in the optical element of the comparative example in which the shape of the interface between the first fluid and the second fluid is a spherical shape. FIG. 23 is a cross-sectional view schematically showing an example of a state in which the shape of the interface between the first fluid and the second fluid is disturbed in the optical element of the comparative example.

  In FIG. 19, the optical element 101, the container 102, the first fluid 105, the second fluid 106, and the differential pressure generating unit 107 are the optical element 1, the container 2, the first fluid 5, and the second fluid 6, respectively. This corresponds to the differential pressure generator 7. In addition, the space 108, the first space 109, the second space 110, the first container member 111, the main surface 111a, the opposite surface 111b, the second container member 112, the main surface 112a, the opposite surface 112b, the first The opening 113, the second opening 114, the first sealing member 115, and the second sealing member 116 are the space 8, the first space 9, the second space 10, and the first container member, respectively. 11, main surface 11a, opposite surface 11b, second container member 12, main surface 12a, opposite surface 12b, first opening 13, second opening 14, first sealing member 15, second This corresponds to the sealing member 16. The first pressure adjusting unit 121, the actuator 123, the diaphragm 124, and the space 125 correspond to the first pressure adjusting unit 21, the actuator 23, the diaphragm 24, and the space 25, respectively.

  However, in the optical element 101 of the comparative example, no film member is provided. That is, in the optical element 101 of the comparative example, the first fluid 105 and the second fluid 106 are in direct contact with each other, and the interface 103 is formed. In the optical element 101 of the comparative example, the buffer tank is not provided outside the container 102, and the orifice for communicating the inside of the buffer tank and the second space 110 is not provided. When the volume of the second space 110 decreases, a space 108 a for escaping the second fluid 106 is provided inside the container 102 as a part of the second space 110.

  Also in the optical element 101 of the comparative example, the diaphragm 124 is convex upward by applying a voltage so that the actuator 123 made of, for example, a piezoelectric element extends in the vertical direction (thickness direction) and contracts in the horizontal direction (in-plane direction). The volume of the first space 109 is reduced by bending the shape. Accordingly, the pressure in the first space 109 with respect to the pressure in the second space 110 can be increased, and the differential pressure in the first space 109 with respect to the second space 110 can be made positive. Due to this differential pressure, as shown in FIG. 20, the shape of the interface 103 between the first fluid 105 and the second fluid 106 is deformed so as to be convex upward. Note that the volume of the space 108a for allowing the second fluid 106 to escape is reduced compared to when the pressure in the first space 109 is equal to the pressure in the second space 110 (as shown in FIG. 19).

  On the other hand, by applying a voltage so that the actuator 123 made of, for example, a piezo element contracts in the vertical direction (thickness direction) and extends in the horizontal direction (in-plane direction), the diaphragm 124 has a convex shape downward. The volume of the first space 109 is increased by bending. Accordingly, the pressure of the first space 109 with respect to the pressure of the second space 110 can be reduced, and the differential pressure of the first space 109 with respect to the second space 110 can be made negative. Due to this differential pressure, as shown in FIG. 21, the shape of the interface 103 between the first fluid 105 and the second fluid 106 is deformed so as to be convex downward. At this time, the volume of the space 108a for escaping the second fluid 106 is larger than when the pressure in the first space 109 is equal to the pressure in the second space 110 (as shown in FIG. 19). To increase.

  Energy is minimized when the shape of the interface 103 between the first fluid 105 and the second fluid 106 is deformed so as to be convex upward or when it is deformed so as to be convex downward. Therefore, the shape of the interface 103 tends to be a spherical shape. For example, the shape that minimizes the surface energy of the first fluid 105 and the second fluid 106 that are liquids is a spherical shape in which the surface area per unit volume (specific surface area) is small, and the interface 103 This is considered to be because the surface tension works to return the shape of the interface 103 back to the spherical shape when the shape deviates from the spherical shape.

  As shown in FIG. 22, when the shape of the interface 103 is a spherical shape, the refraction angle of the light transmitted through the portion (peripheral portion) 103b far from the optical axis OA1 of the interface 103 is close to the optical axis OA1 of the interface 103. It becomes larger than the refraction angle necessary for focusing at the same position as the light transmitted through the portion (center portion) 103a. Therefore, the focal position FP2 of the light transmitted through the peripheral portion 103b is shifted to the interface 103 side from the focal position FP1 of the light transmitted through the central portion 103a, and blurring or the like occurs in the imaging of the light transmitted through the interface 103. So-called spherical aberration occurs.

  On the other hand, the moving weight of the first fluid 105 and the moving weight of the second fluid 106 when the shape of the interface 103 between the first fluid 105 and the second fluid 106 is deformed are those when the fixed focus lens is moved. Less than the moving weight of. Further, the response time when the actuator 123 made of a piezo element is bent is short (for example, 1 msec or less).

  However, in the optical element 101 of the comparative example, the lens surface constituting the variable focus lens is the interface 103 between the first fluid 105 and the second fluid 106. Therefore, when an impact or vibration is applied to the optical element, the first fluid 105 and the second fluid 106 may vibrate, and the shape of the interface 103 may be disturbed as shown in FIG. Once the shape of the interface 103 is disturbed, it may take, for example, about 30 msec for the vibration of the first fluid 105 and the second fluid 106 to attenuate and the shape of the interface 103 to converge. As a result, in the optical element 101 of the comparative example, a time of about 30 msec, for example, is required as the time until the variable focus lens is actually focused. Further, even if the lens is already in focus, it takes about 30 msec, for example, to recover the focus after the shape of the interface 103 is disturbed by the impact or vibration applied to the optical element. It is.

  For such a problem that the shape of the interface 103 is likely to be disturbed when such an impact or vibration is applied, it is conceivable to move the fixed focus lens by a mechanical moving mechanism instead of the variable focus lens. However, the mechanical movement mechanism has a problem that it takes time to move the fixed focus lens to the in-focus position in order to move a heavy member, that is, a member having a large inertia. Also, after the fixed focus lens is moved to the in-focus position, it usually takes about 100 msec, for example, until the vibration of the large inertia member generated during the movement is attenuated, that is, until it is actually focused. It may take.

  Further, in the optical element 101 of the comparative example, when the volume of the second space 110 is reduced, a space 108 a for allowing the second fluid 106 to escape is provided inside the container 102 as a part of the second space 110. It has been. Therefore, when the optical element is tilted by a small angle due to impact or vibration, the air in the space 108a is in the first fluid 105 or the second fluid in the interface 103 or in the vicinity of the interface 103. 106 may enter as bubbles, and the shape of the interface 103 may be disturbed.

<Main features and effects of the present embodiment>
FIG. 24 is a diagram schematically illustrating a light refraction state in the optical element according to Embodiment 1 in which the shape of the interface between the first fluid and the second fluid is an aspherical shape.

  As described with reference to FIG. 1, in the optical element 1 of the first embodiment, the film member 3 capable of transmitting light is provided inside the container 2. The membrane member 3 partitions the space 8 inside the container 2 into a first space 9 and a second space 10. The first space 9 is filled with the first fluid 5, and the second space 10 is filled with the second fluid 6. In the film member 3, the elastic modulus distribution of the film member 3 is a concentric distribution centering on the optical axis OA of light transmitted through the film member 3. Alternatively, the membrane member 3 has an axisymmetric shape about the optical axis OA of light transmitted through the membrane member 3 and has an aspherical shape. Then, when the differential pressure is generated by the differential pressure generating section 7 by appropriately setting the distribution of elastic modulus, or by appropriately setting the axisymmetric and aspherical shape, the shape of the membrane member 3 Can be transformed into an arbitrary shape among aspherical surfaces composed of paraboloids, hyperboloids, ellipsoids, and curved surfaces represented by higher-order polynomials such as quartic surfaces. Therefore, it can suppress that the shape of the interface of the 1st fluid 5 and the 2nd fluid 6 becomes a spherical shape. When the shape of the interface (film member 3) between the first fluid 5 and the second fluid 6 is an aspherical shape, as shown in FIG. 24, a portion far from the optical axis OA of the film member 3 ( The refraction angle of the light transmitted through the peripheral portion 3b is larger than the refraction angle necessary for focusing at the same position as the light transmitted through the portion (center portion) 3a close to the optical axis OA of the film member 3. Can be suppressed. As a result, according to the optical element 1 of the first embodiment, the focal position of the light transmitted through the peripheral portion 3b is shifted from the focal position FP of the light transmitted through the central portion 3a, as compared with the optical element 101 of the comparative example. It is possible to suppress the occurrence of blurring or the like in the imaging of light transmitted through the film member 3, that is, the occurrence of blurring or the like in the imaging of light due to spherical aberration.

  Moreover, in the optical element 1 of Embodiment 1, since the 1st fluid 5 and the 2nd fluid 6 are contacting via the film | membrane member 3, when an impact and a vibration are added to the optical element 1 However, the shape of the interface between the first fluid 5 and the second fluid 6 is not easily disturbed. In addition, since the film member 3 is present, the amplitude of the vibration at the interface between the first fluid 5 and the second fluid 6 when an impact or vibration is applied to the optical element 1 is small. Therefore, in the optical element 1 of the first embodiment, the vibration at the interface between the first fluid 5 and the second fluid 6 is attenuated in a time shorter than the optical element 101 of the comparative example, for example, about 10 msec, Disturbances in the shape of the interface converge. As a result, in the optical element 1 of the first embodiment, the time for actually focusing the lens is reduced to, for example, about 10 msec. That is, according to the optical element 1 of the first embodiment, it can be focused in a fraction of the time compared to the optical element 101 of the comparative example, and by improving the response speed until focusing, The performance of the optical element can be improved.

  In addition, the time required to recover the focus after the impact or vibration is applied to the optical element in the already focused state is shortened to, for example, about 10 msec. That is, according to the optical element 1 of the first embodiment, focusing can be recovered in a fraction of the time compared to the optical element 101 of the comparative example, and stability after focusing is improved. As a result, the performance of the optical element can be improved.

  In addition, according to the optical element 1 of Embodiment 1, it can focus in about one-tenth of time compared with the case where the conventional fixed focus lens is moved by a moving mechanism.

  In the optical element 1 according to the first embodiment, the buffer tank 31 is provided outside the container 2, and the inside of the buffer tank 31 communicates with the second space 10 via the orifice 32. Thereby, even when the membrane member 3 is bent so as to have a convex shape and the volume of the second space 10 is reduced, the second fluid 6 can be released to the outside of the second space 10. Further, since the orifice 32 is present, the air inside the buffer tank 31 enters the second space 10 as bubbles when the optical element is tilted by a small angle due to impact or vibration, and the membrane member 3 It is possible to prevent the shape, that is, the shape of the interface between the first fluid 5 and the second fluid 6 from being disturbed.

(Embodiment 2)
<Shape detection mechanism>
Next, a shape detection mechanism according to an embodiment of the present invention will be described with reference to the drawings. The shape detection mechanism of the second embodiment is an optical shape detection mechanism using the variable focus lens, which is the optical element of the first embodiment, as an imaging system lens.

  FIG. 25 is a diagram schematically showing the configuration of the shape detection mechanism of the second embodiment.

  The shape detection mechanism includes a stage 42 that holds the detected object 41 and a detector 43 that detects the shape of the detected object 41 held on the stage 42. Between the detected object 41 held on the stage 42 and the detector 43, an objective lens 44 and an imaging system lens 45 are provided. As the detector 43, for example, a CCD (Charge Coupled Device) camera can be used. The optical element 1 according to Embodiment 1 can be used as the imaging system lens 45.

  In FIG. 25, in the optical element 1 (imaging system lens 45), for example, the second fluid 6 has a refractive index larger than the refractive index of the first fluid 5. Then, the pressure in the first space 9 filled with the first fluid 5 is reduced with respect to the pressure in the second space 10 filled with the second fluid 6, and the second pressure with respect to the second space 10 is reduced. By setting the differential pressure in the first space 9 to a negative pressure, the shape of the membrane member 3, that is, the shape of the interface between the first fluid 5 and the second fluid 6 becomes a convex shape downward. To deform. Then, as described in the first embodiment, the voltage applied to the piezo element 23 (see FIG. 1) is adjusted, and the amount of deformation of the interface is adjusted, so that the optical element is detected from the detected object 41 via the objective lens 44. The focal length of the optical element 1 can be changed so that the light R incident on the element 1 is focused at the position of the detector 43.

  Alternatively, the optical element 1 (imaging system lens 45) may be arranged so that the vertical arrangement of the optical element 1 is opposite to the vertical arrangement shown in FIG. At this time, for example, it is assumed that the first fluid 5 has a refractive index larger than the refractive index of the second fluid 6. Then, the pressure in the first space 9 filled with the first fluid 5 is increased with respect to the pressure in the second space 10 filled with the second fluid 6, and the second pressure with respect to the second space 10 is increased. By making the differential pressure in the first space 9 positive, the shape of the membrane member 3, that is, the shape of the interface between the first fluid 5 and the second fluid 6, is convex downward (FIG. 1). The upper and lower arrangements shown in FIG. 5 can be deformed so as to have a convex shape.

<Shape inspection device>
Next, a shape inspection apparatus according to an embodiment of the present invention will be described with reference to the drawings. The shape inspection apparatus according to the present embodiment is a shape inspection apparatus incorporating the above-described shape detection mechanism, and a so-called TAB such as a drive IC mounted on the periphery of an FPD display substrate such as liquid crystal or plasma, COF, FPC, or the like. And a display board module assembly line for mounting peripheral boards. Hereinafter, a display substrate module assembly line in which an inspection unit for inspecting the attachment state of the ACF is incorporated will be described as an example after an anisotropic conductive film (ACF) is attached to the display substrate.

  FIG. 26 is a diagram schematically showing a configuration of a display substrate module assembly line in which an inspection unit which is a shape inspection apparatus according to the second embodiment is incorporated.

  The display substrate module assembly line 51 performs various processing operations on the periphery of the display substrate P while sequentially transporting the display substrate P from the left to the right in FIG. It is a device that performs assembly work such as IC and TAB. As the transport device 52, for example, a device configured to transport the substrate transport member 52a on which the display substrate P is mounted along the guide rail 52b can be used.

  The display board module assembly line 51 includes (1) a terminal cleaning process for cleaning the TAB attaching part at the end of the display board P, and (2) an anisotropic conductive film (ACF) at the end of the display board P after cleaning. ACF process for pasting, (3) ACF inspection process for inspecting the pasting state of the pasted ACF, (4) Mounting process for positioning and mounting TAB and IC on the substrate wiring at the position where the ACF is pasted, (5) Mounted It is configured to sequentially perform a crimping process of thermally bonding the TAB and IC and fixing them with ACF, and further performing a processing operation of mounting a PCB substrate as a peripheral substrate after the end of the substrate side or after all processing sides are completed. ing.

  In the display board module assembly line 51, from the left to the right in FIG. 26 (in the X direction), a terminal cleaning processing work device 54, an ACF sticking processing work device 55, a TAB / IC mounting processing work device 56, and a main pressure bonding process. A working device 57 is provided. Further, an ACF application state inspection unit 58 is provided between the ACF application processing work device 55 and the TAB / IC mounting processing work device 56. In the terminal cleaning processing work device 54, the TAB attaching part at the end of the display substrate P is cleaned. In the ACF sticking processing work device 55, an anisotropic conductive film (ACF) is stuck on the edge of the display substrate P after cleaning. In the TAB / IC mounting processing work device 56, the TAB or IC is positioned and mounted on the substrate wiring at the position where the ACF is pasted. The main press-bonding processing device 57 heat-presses the mounted TAB or IC. The ACF attachment state inspection unit 58 inspects the attachment state of the attached ACF. In FIG. 26, the illustration of the PCB substrate mounting processing work apparatus is omitted.

  Next, the ACF sticking state inspection unit 58 will be described.

  FIG. 27 is a diagram schematically showing the main part of the display substrate module assembly line of the second embodiment, centering on the ACF attachment state inspection unit. 27 shows the ACF sticking processing work device 55, the ACF sticking state inspection unit 58, and the transport device 52 in the display substrate module assembly line 51 shown in FIG. FIG. 27 also shows a general control unit 59 that controls the entire display board module assembly line 51, a monitor 60a that displays the line status, and a computer 60b.

  As shown in FIG. 26 and FIG. 27, the ACF sticking processing work device 55 has four ACF sticking processing work units 55 a to 55 d. The ACF sticking state inspection unit 58 is provided between the unit device 55d downstream of the four units and the TAB / IC mounting processing work device 56, and conveys the display substrate P to the next TAB / IC mounting processing work device 56. Inside, the ACF pasted by the four ACF pasting processing work units 55a to 55d in the preceding stage is imaged and inspected. The transport device 52 includes a drive unit 52c that drives the substrate transport member 52a and a linear encoder 52d for recognizing the position of the display substrate P, which is controlled by the overall control unit 59.

  The ACF application state inspection unit 58 controls the imaging timing and the like and receives an image in response to an instruction from the illumination unit 61 and the imaging unit 62 for imaging the ACF application unit and the device control unit 70 of the ACF application processing work device 55. It has an image processing unit 63 that processes signals, and a display unit 64 that displays ACF pasting results and the like.

  FIG. 28 is a diagram showing a main part necessary for inspection and a display substrate to be inspected in the configuration shown in FIG. As shown in FIG. 28, the illumination unit 61 includes an LED (Light Emitting Diode) 61a, a condenser lens 61b, and an LED power source 61c. The imaging unit 62 includes a line sensor camera 62a, an objective lens 62b, and an imaging system lens. 62c.

  In the present embodiment, the shape detection mechanism described above can be used as the imaging unit 62. That is, as the line sensor camera 62a, the objective lens 62b, and the imaging system lens 62c, the above-described detector 43 of the shape detection mechanism, the objective lens 44, and the imaging system lens 45 can be used. That is, the optical element 1 of Embodiment 1 can be used as the imaging system lens 62c.

  In the present embodiment, a height position changing mechanism 65 that changes the height position of the imaging system lens 62c itself may be provided together with the imaging system lens 62c. As a result, even when the height of the detected object is greatly different for each detected object, the light incident on the imaging system lens 62c is changed at the position of the line sensor camera 62a according to the height of each detected object. It is possible to focus accurately. FIG. 28 shows an example in which a height position changing mechanism 65 is provided together with the imaging system lens 62c.

  Furthermore, when it is known that the height of the detected object differs for each detected object, for example, the height data for each detected object is previously stored in the apparatus control unit 70 that controls the ACF sticking processing work apparatus 55. Enter. Then, after the detection of the immediately preceding detection object is completed and before the detection of the detection object starts, first, the height position changing mechanism 65 is driven in response to an instruction from the apparatus control unit 70, and the imaging system By changing the height position of the lens 62c, the light incident on the imaging system lens 62c is focused at a position close to the position of the line sensor camera 62a. Next, immediately before the detection of the detected object, the shape of the film member 3 is deformed and the focal length of the optical element 1 is changed so that the light incident on the imaging system lens 62c is changed to the position of the line sensor camera 62a. To focus on. As a result, even when the height of the detected object is greatly different for each detected object, the light incident on the imaging system lens 62c is changed at the position of the line sensor camera 62a according to the height of each detected object. It is possible to focus accurately and improve the inspection speed.

  FIG. 29 is a diagram for explaining a method for efficiently inspecting various ACF attachment states in the shape inspection apparatus according to the second embodiment. In FIG. 28 and FIG. 29, an imaging region for inspecting the ACF attachment state during conveyance of the display substrate P is shown as SH.

  In the ACF application state inspection of the present embodiment, areas (determination areas 71a, 71b, 71c, 71e) where the ACF must exist are provided at the application positions of each ACF, for example, the outer peripheral part (four sides) of the determination area Processing can be performed only with the upper pixel. In FIG. 29, an ACF 73a in the determination area 71a shows an example of passing the inspection. Further, ACFs 73b and 73c in the determination areas 71b and 71c show examples in which the inspection fails. Further, since there is no ACF in the determination area 71e, an example in which the inspection fails is shown. The determination area is an inner area obtained by subtracting the pasting error from the ACF pasting position, as indicated by 71a, which is an area including the passing ACF 73a. 74a, 74b, 74c and 74e indicate leads of the display substrate P in the determination areas 71a, 71b, 71c and 71e, respectively. Reference numeral 75 denotes a substrate alignment mark (substrate mark).

  FIG. 30 is a process flow diagram showing the inspection operation of the ACF attachment state inspection.

  First, it is detected by the ACF sticking processing work device 55 that the ACF sticking processing work has been completed, the display substrate P is transported to the next TAB / IC mounting processing work device 56, and during the transport, the ACF sticking state inspection unit 58 is transported. Thus, the image of the imaging region SH shown in FIGS. 28 and 29 is acquired (step S11). Next, a substrate alignment mark (substrate mark) 75 formed on the display substrate P is detected from the captured image (step S12). Next, based on the reference value of the length between the substrate marks 75 at both ends and the calculated value of the length between the substrate marks 75 calculated based on the captured data, the display substrate by the correction of the expansion and contraction of the image and the alignment P angle correction is performed (step S13). Also, determination areas 71a, 71b, 71c, 71e are set based on the work content and the board mark 75 obtained by the image processing (step S14). Next, the ACF application state is determined (step S15). Thereafter, the determination result, the captured image data, and the like are transferred to the overall control unit 59 (step S16).

  In step S15, for example, the luminance values on the outer periphery of the determination area are sequentially compared with the determination threshold value Sv. When the luminance values of all the outer peripheral portions are lower than the determination threshold value Sv, the ACF is normal as shown by ACF 73a in FIG. Since it is affixed at a normal position in a normal state, it can be determined as acceptable. On the other hand, when any one of the luminance values of the entire outer peripheral portion is higher than the determination threshold value Sv, it can be determined as rejected.

  In the present embodiment, the optical element 1 of the first embodiment can be used as the imaging system lens 62c of the imaging means 62. The film member 3 of the optical element 1 has a distribution of elastic modulus of the film member 3 that is a concentric distribution or an axially symmetric shape and an aspheric shape, and an imaging system. It is possible to suppress the occurrence of blurring or the like due to spherical aberration in the image formation of the lens 62c. Further, the optical element 1 can recover the focus in a fraction of the time compared to the conventional case even when an impact or vibration is applied to the imaging system lens 62c, and the stability after the focus is achieved. The performance of the imaging lens 62c can be improved by improving the performance. Accordingly, when the ACF attachment state inspection is performed in the display substrate module assembly line 51, it is possible to suppress blurring and the like due to spherical aberration in the image formation of the imaging system lens 62c and to the impact and vibration of the imaging system lens 62c. After the time is added, the time required to recover the focus can be shortened, and the inspection accuracy and inspection speed of the ACF sticking state inspection can be improved. In addition, when the ACF attachment state inspection is performed in the display substrate module assembly line 51, the substrate alignment mark (substrate mark) 75 can be detected with higher accuracy in a short time, and the inspection accuracy of the ACF attachment state inspection is improved. Can do.

  Further, when the height position changing mechanism 65 is provided together with the optical element 1, the light incident on the imaging system lens 62 c can be changed even if the height of the object to be detected varies greatly from object to object. Depending on the height of the detected object, the line sensor camera 62a can be accurately focused.

  In the second embodiment, a case has been described in which the shape inspection apparatus incorporating the optical element 1 of the first embodiment is applied to a process of inspecting the attachment state of the ACF after attaching the ACF to the display substrate. However, the second embodiment can be applied to the step of inspecting the ACF attachment state after attaching the ACF to a so-called TAB such as COF or FPC instead of the display substrate, and similar effects can be obtained.

(Embodiment 3)
In the second embodiment, the shape inspection apparatus incorporating the optical element 1 of the first embodiment inspects the ACF attachment state. However, the shape inspection apparatus incorporating the optical element 1 according to the first embodiment may detect defects by comparing patterns formed on a semiconductor integrated circuit manufacturing mask or the like with each other.

<Shape inspection device>
Next, a shape inspection apparatus according to an embodiment of the present invention will be described with reference to the drawings. The shape inspection apparatus according to the present embodiment is a shape inspection apparatus incorporating a shape detection mechanism similar to the shape detection mechanism described in the second embodiment, and includes a printed circuit board, a printed circuit board manufacturing mask, a semiconductor integrated circuit wafer, This is a pattern inspection apparatus for inspecting a pattern formed on a semiconductor integrated circuit manufacturing mask or the like at high speed. In the following, when performing an appearance inspection of a semiconductor integrated circuit manufacturing mask (photomask), a defect determination process is performed while comparing an image signal obtained by imaging the inspection target pattern on the photomask with reference pattern data. A pattern inspection apparatus that performs the above will be described as an example.

  FIG. 31 is a block diagram of a pattern inspection apparatus which is a shape inspection apparatus according to the third embodiment. 32 and 33 are explanatory diagrams of two-dimensional pattern scanning of the pattern inspection apparatus which is the shape inspection apparatus according to the third embodiment. FIG. 34 is a block diagram of a defect candidate detection unit of the pattern inspection apparatus which is the shape inspection apparatus according to the third embodiment.

  As shown in FIG. 31, the pattern inspection apparatus is for inspecting a mask 81 to be inspected. The pattern inspection apparatus is provided with an XY stage 82a, a mechanism control device 82b, and a coordinate measuring device 82c. The coordinate measuring device 82c from the XY stage 82a constitutes a scanning unit that scans the inspection mask 81. The pattern inspection apparatus includes an illumination light source 83a, a condenser lens 83b, a microscope 83c, an imager 84a, an A / D converter 84b, and a timing circuit 84c. The above-described illumination light source 83a to timing circuit 84c constitute an imaging unit that images the inspection target pattern on the inspection mask 81. Furthermore, the defect inspection unit 85 is provided in the pattern inspection apparatus.

  In addition, the pattern inspection apparatus is provided with a bit pattern generator 86, a memory interface 87, and a reference data memory 88. The reference data memory 88 from the bit pattern generator 86 constitutes a reference pattern data generator for generating reference pattern data. Furthermore, a control processing unit 89 is provided in the pattern inspection apparatus.

  In the present embodiment, the shape detection mechanism described in the second embodiment can be used for a part of the imaging unit. That is, the detector 43 of the shape detection mechanism described above can be used as the image pickup device 84a, and the objective lens 44 and the imaging system lens 45 of the shape detection mechanism described above can be used as the microscope 83c. Among these, the optical element 1 of Embodiment 1 can be used as the imaging system lens 45.

  In the pattern inspection apparatus configured as described above, first, the inspection mask 81 mounted on the XY stage 82a is transmitted and illuminated by the illumination light source 83a and the condenser lens 83b, and the pattern image on the inspection mask 81 obtained at this time is obtained. The image is magnified by the microscope 83c, and this pattern image (optical image) is detected by the image pickup device 84a and converted into an electrical video signal.

  On the other hand, as a reference pattern signal (reference pattern signal), reference data recorded in a reference data memory (for example, a magnetic tape device) 88 is generated by a bit pattern generator 86 via a memory interface 87. The reference pattern signal and the video signal from the image pickup device 84a are compared in the defect candidate detection unit 85, and defect determination processing is performed.

  As shown in FIG. 32, the mask 81 to be inspected generally has a glass 130 in which a large number of functional patterns 131 of chips (one integrated circuit, also called a die) are repeatedly arranged in the X and Y directions. The XY stage 82a on which the inspection mask 81 is mounted is driven by a mechanism control device 82b based on data set and input in advance, and is controlled to scan the entire surface of the inspection mask 81. Also, as shown in FIG. 33, IC (integrated circuit) chip patterns 131a and 131b are obtained by repeating the same shape pattern. Then, the patterns 131a and 131b are scanned in the X direction with one inspection width (sensor width) L with respect to the image pickup device 84a, and when the end of the effective portion 132 of the mask pattern is reached, the Y direction with respect to the image pickup device 84a. The two-dimensional pattern scan of the entire mask surface is performed by repeating the operation of moving and scanning in the -X direction again with respect to the image pickup device 84a. Note that A and B in FIG. 33 are effective portions as chips, and C in FIG. 33 is a dicing area.

  Next, the configuration operation of the defect candidate detection unit 85 will be described with reference to FIG.

  The analog image pickup signal of the pattern of the mask 81 to be inspected detected by the image pickup device 84a (see FIG. 31) is converted into a digital signal by the A / D converter 84b and becomes a detection pattern video signal. The detected pattern video signal is input to the multiplexer 94 through the position correction circuit 90 in which the two-dimensional output position on the XY plane is variable by a command from the control processing unit 89, and the buffer memory 92 ( Also sequentially input to # 1 to #m). The buffer memory 92 is a memory composed of a shift register for temporarily pooling image data within a predetermined time, and has a positional deviation correction function. The output from each buffer memory 92 with this positional deviation correction function is input to the multiplexer 94.

The multiplexer 94 is selected one of an input from the input or the buffer memory 92 from the position correcting circuit 90, is input to the selected output to the defect detection circuit 98 as the detected image data V _D. The detected image data V _D is input to the defect detection circuit 98 and also input to the analysis memory 96, stored as defect candidate image data in the analysis memory 96, and later read by the control processing unit 89 for content analysis. Is now possible.

  On the other hand, the reference pattern signal generated by the bit pattern generator 86 (see FIG. 31) is input to the multiplexer 95 through the position correction circuit 91 and also sequentially input to the buffer memories 93 (# 1 to #m). The Similar to the buffer memory 92, the buffer memory 93 has a positional deviation correction function. The output from each buffer memory 93 with this positional deviation correction function is input to the multiplexer 95.

The multiplexer 95 is selected either an input or an input from the buffer memory 93 from the position correcting circuit 91, input selected is outputted to the defect detection circuit 98 as the standard image data V _R. Further, the standard image data V _R is inputted to the defect detection circuit 98, the analysis also stored is input to the memory 97, is read by the control processor 89 after, so that the possible contents analyzed.

Detected image data V _D and standard image data V _R is compared with mismatch detector (not shown) included in the defect detection circuit 98, a mismatch of the detected image data V _D and standard image data V _R is due to true defect Sometimes, a defect detection signal D is output from the defect detection circuit 98. The defect candidate signal D output from the defect detection circuit 98 interrupts the control processing unit 89 via the interrupt controller 99, and the control processing unit 89 responds to the analysis memories 96 and 97 in response thereto. The image signal input is stopped. Subsequently, it compares the detected image data V _D containing defect candidate image stored in the analysis memory 96, and a standard image data V _R stored in the analysis memory 97, a detailed analysis. For example, pseudo defects due to misalignment or the like are removed by this detailed analysis, and only true defects are registered and recorded in the memory of the control processing unit 89. That is, by performing defect candidate determination while performing alignment during inspection, the structure of the defect candidate determiner can be simplified. Furthermore, since it is possible to determine whether the defect is a true defect or a pseudo defect, it is possible to reduce the rate of erroneous determination.

  In the present embodiment, since the optical element 1 of the first embodiment is used as the imaging system lens, the imaging system lens is compared with the case where the optical element 101 of the comparative example described above is used as the imaging system lens. It is possible to suppress the occurrence of blurring or the like due to spherical aberration in image formation, and it is possible to improve the position accuracy of the focus when the image pickup device 84a detects the analog image pickup signal of the pattern of the mask 81 to be inspected. Compared with the case where the optical element 101 of the comparative example described above is used as the imaging system lens, it can be focused in a fraction of the time, and the analog imaging signal of the pattern of the mask 81 to be inspected by the imaging device 84a. It is possible to improve the response speed of focusing when detecting. Further, compared with the case where the optical element 101 of the comparative example described above is used as the imaging system lens, the in-focus state can be recovered in a fraction of the time after the impact or vibration is applied to the imaging system lens. In addition, it is possible to improve the stability of focusing when the image pickup device 84a detects the analog image pickup signal of the pattern of the mask 81 to be inspected. Further, compared to the case where a conventional fixed-focus lens is moved by a moving mechanism as an imaging system lens, it can be focused in approximately one-tenth of the time, and the pattern of the mask 81 to be inspected by the imager 84a. It is possible to improve the focusing response speed when detecting the analog imaging signal.

  In the third embodiment, the case where the shape inspection apparatus incorporating the optical element 1 of the first embodiment is applied to the step of inspecting the shape of the chip pattern on the semiconductor integrated circuit manufacturing mask has been described. However, the third embodiment can be applied to a shape inspection apparatus for inspecting a printed circuit board, a printed circuit board manufacturing mask, a semiconductor integrated circuit wafer, and the like, and similar effects can be obtained.

  Furthermore, the shape inspection apparatus incorporating the optical element 1 of the first embodiment can be applied to a shape inspection apparatus for inspecting the shape of various electronic component products including a semiconductor device. Alternatively, the shape inspection apparatus incorporating the optical element 1 according to the first embodiment is incorporated into an exposure apparatus that performs pattern exposure of the photoresist layer formed on the semiconductor substrate, for example, when a photoresist pattern is formed by photolithography. Also, it can be used as a part of an alignment mechanism that detects and aligns an alignment mark on a semiconductor substrate.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the invention is not limited to the embodiment, and various modifications can be made without departing from the scope of the invention. Needless to say.

  The present invention is effective when applied to an optical element and a manufacturing method thereof.

DESCRIPTION OF SYMBOLS 1 Optical element 2 Container 3, 3e Film | membrane member 3a Center part 3b Peripheral part 3c Base material 3d Adjustment member 3f Type | mold member 3g Base material 4 Peripheral part 5 1st fluid 6 2nd fluid 7 Differential pressure generation part 8 Space 9 1st 1 space 10 2nd space 11 1st container member 11a, 12a Main surface 11b, 12b Opposite surface 12 2nd container member 13 1st opening part 14 2nd opening part 15 1st sealing member 16 Second sealing member 21 First pressure adjustment unit 23 Actuator (piezo element)
24 Diaphragm 25 Space 31 Buffer tank 32 Orifice 32a, 32b End portion 32c End surface 32d Orifice pipe 33 Second pressure adjusting portion 34 Fine hole 41 Object 42 Stage 43 Detector 44 Objective lens 45 Imaging system lens 51 Display substrate module Assembly line 52 Transport device 52a Substrate transport member 52b Guide rail 52c Drive unit 52d Linear encoder 54 Terminal cleaning processing work device 55 ACF sticking processing work device 55a to 55d ACF sticking processing work unit 56 TAB / IC mounting processing work device 57 Main pressure bonding processing Work device 58 ACF sticking state inspection unit 59 General control unit 60a Monitor 60b Computer 61 Illuminating means 61a LED
61b Condensing lens 61c LED power source 62 Imaging means 62a Line sensor camera 62b Objective lens 62c Imaging system lens 63 Image processing unit 64 Display unit 65 Height position changing mechanism 70 Device control units 71a, 71b, 71c, 71e Determination area 73a, 73b, 73c ACF
74a, 74b, 74c, 74e Lead 75 Substrate mark (Substrate alignment mark)
81 Mask to be inspected 82a XY stage 82b Mechanism controller 82c Coordinate measuring device 83a Illumination light source 83b Condenser lens 83c Microscope 84a Imager 84b A / D converter 84c Timing circuit 85 Defect candidate detection unit 86 Bit pattern generator 87 Memory interface 88 Reference Data memory 89 Control processing unit 90, 91 Position correction circuit 92, 93 Buffer memory 94, 95 Multiplexer 96, 97 Analysis memory 98 Defect detection circuit 99 Interrupt controller 130 Glass 131 Function pattern 131a, 131b Pattern 132 Effective portion D Defect candidate signal FP, FP1, FP2 focal position OA, OA1 optical axis P display substrate SH imaging area Sv determination threshold _{V D} detected image data _{V R} standard image data

Claims (17)

A container having a space formed therein;
A membrane member capable of transmitting light, which divides the space into a first space and a second space;
A first medium filled in the first space;
A second medium filled in the second space and having a refractive index different from that of the first medium;
A differential pressure generating section for generating a differential pressure between the first space and the second space;
Have
By deflecting the film member by the differential pressure generated by the differential pressure generation unit, the focal length of light transmitted through the film member can be changed,
An optical element characterized in that the elastic modulus distribution of the film member is a concentric distribution centering on the optical axis of light transmitted through the film member. The optical element according to claim 1, wherein
The membrane member includes a base material, and an adjustment member that is included in the base material and adjusts an elastic modulus of the membrane member,
The optical element, wherein the distribution of the content ratio of the adjusting member included in the base material is a concentric distribution centering on the optical axis of light transmitted through the film member. The optical element according to claim 1, wherein
Provided outside of the container, and has an air reservoir portion in which the interior communicates with the second space via an orifice portion;
The differential pressure generating unit is a first pressure adjusting unit that adjusts the pressure in the first space,
The optical element is characterized in that the second medium is filled halfway from the end of the orifice portion on the second space side toward the air reservoir portion side. The optical element according to claim 3, wherein
An optical element comprising a second pressure adjusting unit for adjusting an internal pressure of the air reservoir. The optical element according to claim 1, wherein
An optical element, wherein a refractive index of the film member is equal to a refractive index of one of the first medium and the second medium. The optical element according to claim 5, wherein
The optical element, wherein the film member and the one of the first medium and the second medium are made of polydimethylsiloxane. A container having a space formed therein, a film member capable of transmitting light that partitions the space into a first space and a second space, a first medium filled in the first space; A differential pressure is generated between the second medium filled in the second space and having a refractive index different from that of the first medium, and the first space and the second space. An optical element having a differential pressure generating unit that can change a focal length of light transmitted through the film member by bending the film member with the differential pressure generated by the differential pressure generation unit. A method,
(A) preparing the container;
(B) preparing the membrane member;
(C) attaching the membrane member to the container;
(D) filling the first medium with the first medium;
(E) filling the second medium with the second medium;
(F) providing the differential pressure generating portion in the container;
Have
The method of manufacturing an optical element, wherein the distribution of elastic modulus of the film member is a concentric distribution centering on an optical axis of light transmitted through the film member. It is a manufacturing method of the optical element according to claim 7,
The membrane member includes a base material, and an adjustment member that is included in the base material and adjusts an elastic modulus of the membrane member,
In the step (b), the adjustment member is adjusted so that the distribution of the content of the adjustment member included in the base material is a concentric distribution centering on the optical axis of light transmitted through the film member. A manufacturing method of an optical element, which is contained in the base material. It is a manufacturing method of the optical element according to claim 7,
The step (b)
(G) a step of forming the film member by irradiating the photocurable resin with a second light and curing it;
Including
In the step (g), the intensity distribution of the irradiated second light is a concentric distribution centering on the optical axis of the light transmitted through the film member. It is a manufacturing method of the optical element according to claim 7,
The optical element is provided outside the container, and has an air reservoir that communicates with the second space via the orifice,
(H) attaching the air reservoir and the orifice to the container;
Have
In the step (e), after the step (h), the second medium is filled into the second space, and the air reservoir is provided from an end of the orifice portion on the second space side. A method for producing an optical element, characterized by filling partway toward the side. It is a manufacturing method of the optical element according to claim 7,
The method of manufacturing an optical element, wherein a refractive index of the film member is equal to a refractive index of one of the first medium and the second medium. It is a manufacturing method of the optical element according to claim 11,
The method of manufacturing an optical element, wherein the film member and the one of the first medium and the second medium are made of polydimethylsiloxane. A container having a space formed therein, a film member capable of transmitting light that partitions the space into a first space and a second space, a first medium filled in the first space; A differential pressure is generated between the second medium filled in the second space and having a refractive index different from that of the first medium, and the first space and the second space. An optical element having a differential pressure generating unit that can change a focal length of light transmitted through the film member by bending the film member with the differential pressure generated by the differential pressure generation unit. A method,
(A) preparing the container;
(B) preparing the membrane member;
(C) attaching the membrane member to the container;
(D) filling the first medium with the first medium;
(E) filling the second medium with the second medium;
(F) providing the differential pressure generating portion in the container;
Have
The method of manufacturing an optical element, wherein the film member has an axisymmetric shape with respect to an optical axis of light transmitted through the film member, and has an aspherical shape. It is a manufacturing method of the optical element according to claim 13,
The step (b)
(G) A base material made of a resin that can be plastically deformed at a temperature higher than normal temperature has an axisymmetric shape and an aspherical shape, and the base material is at the temperature at which the base material can be plastically deformed. A step of forming the film member by pressing the held mold member and plastically deforming it, and then cooling to room temperature;
The manufacturing method of the optical element characterized by the above-mentioned. It is a manufacturing method of the optical element according to claim 13,
The optical element is provided outside the container, and has an air reservoir that communicates with the second space via the orifice,
(H) attaching the air reservoir and the orifice to the container;
Have
In the step (e), after the step (h), the second medium is filled into the second space, and the air reservoir is provided from an end of the orifice portion on the second space side. A method for producing an optical element, characterized by filling partway toward the side. It is a manufacturing method of the optical element according to claim 13,
The method of manufacturing an optical element, wherein a refractive index of the film member is equal to a refractive index of one of the first medium and the second medium. A method for producing an optical element according to claim 16,
The method of manufacturing an optical element, wherein the film member and the one of the first medium and the second medium are made of polydimethylsiloxane.

Images