JP2009122469A - Aspherical surface optical component, its manufacturing device and method for designing mask used therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aspherical optical component by high-accuracy working which takes much time but does not require manpower by using sputtering vapor deposition, because there are many problems to enhance working accuracy in the conventional method in which an aspherical lens or a reflection mirror is manufactured by press working using a die or polishing. <P>SOLUTION: In the conventional method for forming a deposited film by sputtering vapor deposition flow, the aspherical surface optical component is manufactured by forming a multilayered film having uniform film thickness and polishing it. Various kinds of aspherical surface optical components are formed by the manufacturing device to form a desired aspherical surface film by sputtering vapor deposition by using the mask, wherein the mask rotating between a target and the deposited substrate is driven from the outer periphery, and the shape of a masking blade coping with the change of thickness of the deposited film of an optical system for which correction of aberration center-symmetric is performed is designed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an aspherical optical component capable of correcting the aberration of a light beam in a condensing spherical lens, correcting the aberration of a light beam in a concave spherical reflecting mirror, or outputting a completely parallel light beam, and as a manufacturing apparatus thereof for sputtering. The present invention relates to an apparatus for manufacturing an aspherical optical component that forms an aspherical lens system in which a vapor deposition material is deposited from a target on a flat or concave spherical reflecting mirror surface disposed in the optical path of the concentrating spherical lens by vapor deposition. The present invention also relates to a method for designing a mask shape that rotates between a substrate and a target for forming an aspherical deposited film.

  Conventional processing methods for spherical lens systems, aspheric lens systems, etc. were manufactured by cutting + polishing, pressing, or pressing + polishing. Patent Document 1 discloses a manufacturing method of an aspheric lens system using a molding die that eliminates the polishing process and molds at once.

In the press working for forming in such a mold, it is difficult to work with a minute change of nm (10 ⁻⁹ m), and much labor is required to make the product accuracy 1 μm or less. Further, in machining with an accuracy of 1 μm or less, a large facility for maintaining reproducibility is required, such as a change in shape dimension due to a change in temperature.

In particular, a high-performance aspheric optical component needs to have high dimensional accuracy, but in press working, a considerable amount of polishing must be performed so that no cutting trace remains when the die is made. High technology is required to perform polishing without degrading the aspheric performance with high shape accuracy, and the mold is expensive.

  On the other hand, there is a technique for forming a recording medium on a disk-shaped substrate by depositing sputtered particles from a target in a uniform thin film form within a predetermined region range on the substrate by sputtering. Patent Document 2 discloses that a recording medium layer is manufactured with a uniform thin film on the entire surface of a predetermined doughnut-shaped region surrounded by an inner mask in a central hole portion and an outer mask in an outer peripheral portion.

  In Patent Document 3, a step of alternately laminating a plurality of kinds of substances on a substrate processed into a spherical shape, a step of removing a part of the laminated multilayer film surface and creating an aspherical shape, There has been proposed an aspherical mirror manufacturing method comprising a step of measuring an aspherical shape from the removed pattern on the surface of the multilayer film.

  In the present invention, a multilayer film having a uniform thickness is alternately formed on a substrate using two types of targets by an ion beam sputtering apparatus, and then the surface of the multilayer film is polished by using a small tool polishing apparatus. This is a method for producing a desired aspherical shape from the shape of a striped pattern that appears.

  The thin film thickness control by sputtering is highly accurate and can be applied from 1 μm or less to 1 nm accuracy. However, it has not been considered to directly form a film having a predetermined aspherical thickness on a substrate by sputtering deposition to produce an aspherical lens system or the like.

Japanese Patent Laid-Open No. 5-208833 (second page, FIG. 1) Japanese Patent Laid-Open No. 2003-193131 (second page, FIG. 1) JP 7-84098 A (2nd page, FIG. 1)

  It is an object of the present invention to provide the following aspherical optical component and a manufacturing apparatus therefor as an aspherical lens system that is arranged on a converging spherical lens optical path and corrects aberration of the spherical lens.

  That is, a positive ion generated by ionizing a gas by a high electric field in a vacuum hermetic chamber collides with the target, and atoms are ejected and rotated on the substrate using a sputter deposition space where it is deposited on a flat substrate. To provide an aspherical optical component having a mask and controlling a sputter deposition flow to form an aspherical film having a predetermined film thickness change shape, and a manufacturing apparatus therefor.

  In addition, in order to correct the condensing aberration of the concave spherical reflecting mirror for condensing or outputting parallel light, an aspherical film having a predetermined film thickness change shape is controlled on the concave spherical surface by a rotating mask of the sputter deposition flow. To provide an aspherical optical component with reduced aberration as a parabolic mirror and a manufacturing apparatus therefor.

In order to solve the above problems, the aspherical optical component of the present invention is an aspherical lens that is disposed on the light collecting spherical lens optical path and corrects the aberration of the spherical lens,
The aspheric lens has a blocking part and an opening part using a parallel plane substrate and a sputter deposition flow in which atoms are ejected from a target by positive ions generated by ionizing a gas by a high electric field in an airtight chamber. Then, the flow is controlled by a mask that drives the outer periphery thereof and rotated at a constant angular velocity, and is composed of a deposited film that is circularly deposited on the substrate in a centrosymmetric manner,
By making the material of the target transparent, a lens system in which the deposited film is integrated with the substrate is formed,
The film thickness on each circumference of the deposited film is determined by the length of the opening portion for each circumference. Therefore, if the thickness change shape to be obtained in the radial direction is determined, the length of the opening portion for each circumference is determined. , The masking shape is set,
It is an aspheric lens system in which the film thickness change shape is expressed by at least a high-order polynomial.

In addition, an aspherical film that corrects the aberration of the spherical reflector is formed on the surface of the concave spherical reflector for condensing or outputting parallel light, and a reflective metal thin film is deposited on the surface to correct the aberration. Aspherical parabolic reflector,
The parabolic reflector uses a concave spherical reflector and a sputter deposition flow in which atoms are ejected from a target by positive ions generated by ionizing a gas by a high electric field in an airtight chamber.
The flow is controlled by a mask that has a blocking portion and an opening portion, drives the outer periphery thereof and rotates at a constant angular velocity, and is composed of a deposited film deposited on the concave spherical reflector surface,
When the material of the deposited film is transparent, the reflective metal thin film is provided on the deposited film,
The film thickness on each circumference of the deposited film is determined by the length of the opening portion for each circumference. Therefore, if the thickness change shape to be obtained in the radial direction is determined, the length of the opening portion for each circumference is determined. , The masking shape of the mask is set,
It is an aspheric lens system in which the film thickness change shape is expressed by at least a high-order polynomial.

The aspherical optical component manufacturing apparatus of the present invention is an aspherical optical component (aspherical lens) and aspherical optical component (parabolic reflector) manufacturing apparatus,
The manufacturing apparatus includes a holding mechanism that can set M (one or more) parallel plane substrates or concave spherical mirrors that deposit sputter vapor deposition from a target in an airtight chamber to form the aspheric lens, and the parallel plane substrate or Disposed between the concave spherical mirror and the target and rotated at a constant angular velocity for each parallel plane substrate or concave spherical mirror to form an aspheric optical system that corrects aberrations. The ratio of the cut-off portion and the opening portion on each circumference for each distance is determined, and a mask with a masking blade designed to control the sputter deposition flow from the value of the ratio, and the central portion of the parallel plane substrate or the concave spherical mirror In order to make the aspherical film having the film thickness changing shape including the deposited film, the mask is driven by a mask rotation gear provided on the outer periphery of the mask without using the central axis. And click periphery drive mechanism, characterized by comprising at least a.

Also, a method for designing a masking blade of a mask used in an aspherical part manufacturing apparatus,
In determining the shape of the masking blade that rotates at a constant angular velocity of the mask that is to be deposited on the radial thickness change shape that forms the aspheric optical system that corrects the aberration of the aspheric part,
If the film thickness to be deposited at a position r apart from the center of rotation is d (r) during the time when it is desired to rotate once relative to the angular velocity, it is on the circumference where there is no mask (no blocking part) at the same time. Denote the deposition angle at D, and the opening angle of the arc length L of the opening portion section with respect to the film thickness d (r) on each circumference is represented by θ, the shape of the masking blade is represented by coordinates X, Y The relational expressions X = r cosθ (1) and Y = r sinθ (2)
θ = 2πd (r) / D (3)
The opening angle θ and the coordinates X and Y are calculated from the predetermined film thickness d (r) using the equations (1) to (3), and the coordinates X and Y can be calculated by calculating all changes of r. From this locus, the shape of the opening area of the mask is determined, and the masking blade corresponding to the film thickness to be deposited is determined.

  Further, the arc length L of the opening on the circumference of the radius r is calculated from r · θ, and the arc length L is further divided into n (integer) to arrange a plurality of openings. A mask shape of a plurality of masking blades that improves the stability during rotation of the mask is characterized.

  The aspherical optical component, the manufacturing apparatus thereof, and the mask design method used therefor according to the present invention have the following effects.

  A film thickness layer formed by being deposited on a substrate surface or a spherical surface can be processed with minute changes in nm. Compared to the accuracy of about μm, such as conventional press processing and polishing processing, processing with much higher accuracy can be performed.

Therefore, an aspherical shape that requires high accuracy, in particular, a deposited film is formed and manufactured in a predetermined film thickness changing shape up to the center position, so that the apparatus is suitable.

  There is no need for large equipment to maintain reproducibility such as changes in shape due to changes in temperature.

  The conventional press processing and polishing processing require many steps as described above, such as pretreatment of the mold, in order to produce a highly accurate product. However, if the sputtering space by this apparatus is used, it is not necessary to take the steps described above. Such manual work is unnecessary.

In correcting the aberration of the light beam of the condensing spherical lens, the conventional correcting lens system is designed to integrate the curvature determining the condensing ability and the aspherical shape to remove the aberration, and its usage is limited.
That is, since they are integrated, the aspherical lenses cannot be separated and used in any combination.

  The aberration correction of the luminous flux of the spherical lens for condensing of the present invention is corrected by an aspherical lens deposited on a parallel plane substrate disposed on the optical path of the spherical lens.

  That is, since the condensing lens portion and the correction lens portion are separated, the condensing system is a configuration that removes only aberrations by adding a component in which an aspheric film is deposited on a substrate as a spherical lens that is easy to manufacture.

  Therefore, various spherical lenses can be used. In other words, since only the aberration can be removed without changing the value of the focusing power in the spherical optical system in which the aberration is generated, this configuration is very effective.

  For example, when a single spherical lens having a large aberration is combined with an aspherical optical component formed on the substrate for condensing the laser beam, it is possible to condense up to the diffraction limit.

  Embodiments of an aspheric optical component, an apparatus for manufacturing the same, and a design method for a mask used therefor will be described in detail below with reference to the drawings.

  FIG. 1A shows an example of an aspheric optical component. This example is an aspherical lens that can be used for aberration correction of a condensing spherical lens.

  FIG. 1B shows a state in which the aberration of the focal point 7a of the condensing spherical lens 7 is corrected using the aspheric optical component.

  Here, reference numeral 1 denotes a parallel plane substrate (planar substrate) of an aspheric optical component, and 2 denotes an aberration correction deposit (aspheric lens) deposited on the substrate through a sputter vapor deposition flow through a mask. Although it is desirable that the material of the flat substrate 1 and the material of the target 3 are the same material (for example, quartz), even if heat-resistant glass or multi-component glass is sputtered on the quartz substrate, the adhesion strength is high and integrated. Lens system.

  FIG. 2 shows an actual shape example of the deposit (aspheric lens) 2 of FIG. That is, the relationship between the distance r from the center position 2a of the aspherical lens and its film thickness d (r) is shown.

The position of the horizontal axis 0 in FIG. 2 corresponds to the center position 2a of the deposit (aspheric lens) 2 in FIG. In the vicinity of the center position 2a, the film thickness d (r) is thin, and the changing shape of the film thickness d (r) at a distance r in the radial direction from the center position 2a gradually increases. The aspherical shape can be represented by a higher order polynomial. Although the form of the expression varies depending on the optical application, it is expressed as follows, for example.
d (r) = cr ² / [1+ {1- (1 + K) c ² r ² } ^1/2 ] + α ₁ r ² + α ₂ r ⁴ + α ₃ r ⁶ + α ₄ r ⁸ ------ (A)
^{d (r) = cr 2 /} [1+ {1- (1 + K) c 2 r 2} 1/2] + β 1 r 1 + β 2 r 2 + β 3 r 3 + β 4 r 4 ------ (B)

Where K is the conic constant, c is the reciprocal of the radius of curvature, and α _i and β _i are constants.

  Although most of the aspherical shapes can be expressed by the above formulas (A) and (B), an aspherical lens for correcting the aberration of a specific spherical lens can be designed by the formula (A) or (B). In this case, it is necessary to provide the manufacturing apparatus with a mask 20 for controlling the sputter deposition flow so as to match the changing shape of the film thickness d (r) from the center position 2a represented by this equation. In addition, the example of FIG. 2 is an aspherical shape represented by a sixth order expression.

  The mask 20 is arranged on a flat substrate or a spherical surface to be deposited to control the sputter deposition flow, and rotates a masking blade 20a having a blocking portion and an opening portion at a constant angular velocity ω. Masking blades that change the shape of the film thickness d (r) deposited on the surface of the substrate or spherical surface by the radial direction r during the integer rotation time of the mask 20 according to the radial direction r as shown in equations (A) and (B). The design method will be described later.

  FIG. 3 shows an embodiment of an apparatus for manufacturing an aspheric optical component (aspheric lens system, parabolic reflector). Here, a sputter conceptual diagram of an aspherical optical component manufacturing apparatus deposited on the predetermined film thickness changing shape d (r) using the masking blade is shown.

  Here, reference numeral 10 denotes a vacuum hermetic chamber, and there is a substrate base plate 33 having holes for setting the flat substrate 1 or the concave spherical mirror 8 or the like to be deposited therein.

  Further, there is a mask base plate 32 having a hole for setting the rotating mask 20. Here, reference numeral 30a denotes a mask rotation gear for rotating the mask, and the outer periphery of the mask 20 is rotated by a drive transmission mechanism from the outside of the vacuum hermetic chamber. That is, there is no axis at the center position 20a of rotation, and a predetermined film thickness d (0) can be deposited also at the center position 2a of the deposit on the flat substrate 1 facing this center position.

  Reference numeral 3 denotes a target, which is set to a negative electric potential with respect to the periphery so that the inside of the vacuum hermetic chamber is a high electric field.

Reference numeral 4 denotes positive ions of gas ionized by the high electric field, and the ions collide with the target 3. The gas is argon Ar or the like, and Ar ⁺ ions are generated.

  A number 5 of sputtered atoms flying out from the target 3 is generated, and these particles flow into the entire surface of the mask 20 as a uniform sputter deposition flow 6.

  The sputter vapor deposition flow passes through the masking blade 20a of the rotating mask 20, and deposits around the symmetrical center position 2a of the deposit, thereby forming the deposit (aspheric lens) 2 as shown.

  FIG. 4 shows an embodiment where the masking blade 20a has four blades. As can be seen from the figure, the rotation of the mask 20 is driven via a gear on the outer periphery so that a predetermined film thickness is deposited also in the vicinity of the mask rotation center, that is, in the vicinity of the center position 2a of the deposit on the substrate. . A method for creating the masking blade 20a will also be described later.

  FIG. 4 is a diagram showing the relationship between a centrally symmetric masking blade and a planar substrate. In FIG. 4, when there is a set of a flat substrate 1 on which a sputter deposition flow of sputtered particles 5 from a target 3 is deposited and a mask 20 for controlling deposition on the substrate surface in a vacuum-tight chamber 10 of the manufacturing apparatus 100. Is shown as a conceptual diagram, but in the actual case, it is desirable to provide a vacuum hermetic chamber 10 in which a plurality of sets of the planar substrate 1 and the mask 20 are accommodated.

  Because the control amount of the film thickness by the sputter deposition flow can be several nm as described above, it can be applied to the production of a highly accurate aspheric optical component, while the film thickness is a predetermined thickness, For example, as shown in FIG. 2, it takes a long time to deposit up to about 100 μm. It is sufficient that the manufacturing apparatus 100 is operated for a necessary time without requiring manual operation.

  Therefore, it is an efficient apparatus to deposit the deposited films 2 on the planar substrate 1 simultaneously in the vacuum hermetic chamber 10 of the manufacturing apparatus 100.

  FIG. 5 shows an embodiment of the mask / substrate mounting jig of the manufacturing apparatus 100 as described above. FIG. 5 shows a case where the number of the sets including the planar substrate 1 and the mask 20 for controlling deposition on the substrate surface is four.

  In FIG. 5, an attachment jig for attaching four masks 20 and four flat substrates 1 each is shown.

  Here, reference numeral 30 denotes an entire mask rotation drive mechanism that rotates the four masks 20 along the outer periphery thereof by driving from the outside of the airtight chamber.

  Reference numeral 31 denotes a base plate on which the entire jig is placed, and the sputter deposition flow flows upward from below the base plate.

  Reference numeral 32 denotes a mask base plate, which has mask set holes 32a at four positions at intervals of 90 degrees. The masking blade 20a of the mask 20 has the same shape as the masking blade 20a shown in FIG.

  Reference numeral 33 denotes a base plate for a substrate, and there are substrate setting holes 33a at four positions at intervals of 90 degrees. The center of the substrate setting hole 33a exactly coincides with the center of the mask setting hole 32a, and the masks 20 are arranged on the lower surface of each flat substrate 1 respectively.

  A mask rotating gear 30a is provided along the outer periphery of the mask setting hole 32a. There is a revolution internal gear 37 that meshes simultaneously with the four mask rotation gears 30a, and an outer peripheral revolution gear 38 is provided on the outer periphery thereof. The outer periphery (the uppermost end in FIG. 5) of the revolution outer gear 38 is this gear. Is driven by a rotary drive shaft 39 through a drive gear 39a meshing with the rotary drive shaft 39a. The rotary drive shaft 39 is driven from the outside of the vacuum hermetic chamber 10 by a drive transmission mechanism.

  Although FIG. 5 shows an example in which four masks 20 are attached, set holes for attaching more masks may be provided.

  Next, a method for designing the shape of the masking blade 20a of the mask 20 will be described.

  That is, if the relationship between the distance r from the center and the film thickness d (r) is given, the shape of the masking blade of the mask that satisfies the relationship can be set.

  6, 7, and 8 show that when the film thickness d (r) is constant with respect to the change in the distance r from the center, the film thickness d (r) increases in proportion to the film thickness d (r). ) Shows the shape of each masking blade in the case of complicated changes.

  Hereinafter, the method will be described with reference to FIG. FIG. 9 shows the shape coordinates X and Y of the masking blade 20a to be deposited in the changed shape of the film thickness d (r) when the film thickness d (r) of the shape to be deposited is given, and the opening for each circumference. It is a figure explaining the relationship between angle (theta) and film thickness d (r).

  FIG. 9A shows a plan view of the mask. (B) shows the film thickness d (r) of the shape to be deposited. This film thickness shape corresponds to FIG.

  The masking blade 20a of the mask 20 is a film that is to be deposited at a position separated by r in the radial direction, where R is the radius of the mask 20 to be created when the masking blade 20a is rotated once relative to the flat substrate 1 at a constant angular velocity ω The thickness is d (r).

  Here, it is assumed that the relative rotation is performed once, and the design method is described below. However, the relative rotation may be performed an integer number of times.

  If the film thickness uniformly deposited on the flat substrate 1 during the time 2π / ω when the mask 20 is not present on the entire surface of the flat substrate 1 during the time 2π / ω, the masking blade of the mask 20 is masked. If there is no blocking portion of the masking blade 20a at a certain radial position r of 20a and only the opening portion, the film thickness on the circumference of the radial position r is D.

  In the example of the deposited film thickness d (r) in FIG. 9, d (r) = D at the outermost peripheral position where r = R, and the position on the circumference is only the opening, and d at the center where r = 0. (R) = 0, the position is only the blocking portion, and the ratio of the blocking portion to the opening portion or the length of the arc for each circumference of the diameter r between the radial directions 0 to R is as follows. Is required.

On the circumference of the radius r, the opening interval corresponding to the film thickness d (r) is represented by points A (r, 0) to B (X, Y) as shown in FIG. If the opening angle when the length L looks at the center is θ, the following relational expression is established.
X = r cos θ (1)
Y = r sin θ (2)
θ = 2πd (r) / D (3)

  Accordingly, the radial direction R is changed to a range of 0 ≦ r ≦ R with respect to the film thickness d (r) given or desired to be formed, and the opening angle θ and the coordinates (X , Y).

  A mask 20 having a shape in which a region surrounded by the locus curve of the coordinates (X, Y), the radial line segment (0, 0)-(R, 0), and the circumference of the circle R is open can be designed.

  FIG. 8B shows an example of the mask shape having the above opening. FIGS. 6B and 7B show mask shapes when the film thickness d (r) is constant with respect to the distance r from the center and when the film thickness is linearly proportional.

  Further, in order to improve the stability by reducing the influence of the unstable angular velocity at the time of mask rotation, the arc length L between the opening sections A to B calculated for each circumference r is r and θ. Although calculated | required by a product, the length L of the opening area arc may be divided | segmented into plurality, and it may replace and arrange | position with the interruption | blocking area on the circumference.

  An example is shown in FIG. The arc length L on each circumference is divided into four equal parts, and the circle R is divided into quadrants or quadrants as shown in the figure, and each of the open section arc lengths L is divided into four equal parts. This is a masking blade 20a created by assigning 1/4 (or 1/4 of the length of the cut-off section arc).

  FIGS. 6C and 7C show the mask shapes when the film thickness d (r) is constant with respect to the distance r and linearly proportional to the distance r by the same method.

  FIG. 10 shows various examples of the masking blade 20a of the mask 20 designed by the equations (1), (2), and (3).

  FIG. 10A shows the shape of the masking blade 20a designed by the X and Y trajectory curves satisfying the equations (1) to (3).

  FIGS. 10B and 10C show the shape of the masking blade 20a created by combining the arc length L calculated in FIG.

  FIGS. 10D and 10E show the shape of the masking blade 20a formed by combining the arc length L calculated in FIG. 10A into 1/4.

  The lens systems and the like by the deposition of the aspherical optical components described above are all centrally symmetric components deposited at the center position, and the center of the flat substrate 1 and the rotation center of the mask 20 coincide with each other.

  An apparatus for manufacturing off-axis parts having a center-symmetric axis outside the part with respect to the center-symmetric part will be described. When a large aberration correcting lens system having a large diameter is formed using off-axis components, a plurality of these off-axis components may be arranged on a predetermined circumference and combined.

  FIG. 11 shows a configuration in the vacuum hermetic chamber 10 when manufacturing such an off-axis component.

  FIG. 11A shows a case where four off-axis parts are manufactured simultaneously.

Here, 8 indicates a concave spherical substrate. A plurality (four in FIG. 11) of the concave spherical substrates 8 are arranged on a spherical surface indicated by a broken line as shown in the figure, and arranged on a circumference having a fixed diameter from the axial center of the mask 20 to be rotated.

  On the surface side of the concave spherical substrate 8, there is a rotating mask 20, which controls off-sputter deposition flow and manufactures off-axis components. These aspherical optical components which are off-axis components are used by being arranged on the same circumference. The function is the same as that obtained by forming an aspherical deposited film on a large substrate and cutting out the end portion.

  Since a plurality of off-axis parts only need to be arranged concentrically from the rotation center of the mask, a large manufacturing apparatus is not required.

  FIG. 11B shows a state in which a plurality of off-axis parts are arranged on the same circumference away from the central axis, and the rays output from the focal point are reflected by the parabolic mirror 9 to generate parallel rays. A parabolic mirror 9 has a metal vapor-deposited thin film 9a on the surface thereof. In addition, when the target is made of a metal as a reflector, it can be replaced with the metal vapor-deposited thin film 9a.

  FIGS. 12 and 13 show an example of light focusing in which a spherical mirror 8 having a central symmetry and an aspherical parabolic mirror 9 are deposited on the surface thereof, and aberration correction is performed. Incidentally, a metal-deposited thin film 9a is present on the surface of the parabolic mirror 9 in FIG.

  In FIG. 12, there is aberration and parallel input rays do not converge at the focal point. Therefore, the imaged characters cannot be read.

  In FIG. 13, the aberration of the spherical mirror is corrected, and the parallel input light beam is focused on the focal point. Therefore, the imaged characters can be easily read.

An example of an aspherical optical component, (a) is a cross-sectional view of an aspherical lens, and (b) is a diagram showing an aberration correction state using the same. It is a figure which shows the film thickness specific example of an aspherical lens deposit. It is an aspherical optical component manufacturing apparatus sputter | spatter conceptual diagram. It is a figure which shows the relationship between a center symmetrical masking blade | wing and a plane board | substrate. It is an Example of the attachment jig | tool of a mask and a board | substrate. The case where the film thickness is constant with respect to the distance from the center is shown. (A) is the relationship between the film thickness and the mask, (b) is the locus of X and Y, and (C) is an example of the mask shape. The case where the film thickness is proportional to the distance from the center is shown, (a) is the relationship between the film thickness and the mask, (b) is the locus of X and Y, and (C) is an example of the mask shape. The case where the film thickness changes in a complicated manner with respect to the distance from the center is shown, (a) is the relationship between the film thickness and the mask, (b) is the locus of X and Y, and (C) is an example of the mask shape. FIG. 5 is a relationship diagram of a deposited film thickness, a shape of a masking blade, coordinates X and Y, and an opening angle θ. In various mask shape examples, (a) is a masking blade designed with X and Y trajectory curves, and (b) and (c) are shape examples in which the arc length of (a) is divided into ½. , (D), (e) are examples of shapes in which the arc length is divided into 1/4 and combined. An example of deposition on off-axis parts is shown, (a) is an example of manufacturing four off-axis parts simultaneously, and (b) is a diagram showing an example of using off-axis parts. An example of light focusing with aberration of a spherical mirror is shown, (a) is a spot diagram, (b) is an image, and (c) is a diagram showing an optical arrangement. An example of light focusing aberration correction by an aspherical mirror is shown, (a) is a spot diagram, (b) is an image, and (c) is a diagram showing an optical arrangement.

Explanation of symbols

1 Parallel plane substrate (plane substrate)
2 Deposit (Aspherical lens)
2a Center position of deposit (aspheric lens) 3 Target 4 Gas, positive ion 5 Sputtered particle, atom 6 Sputter deposition flow 7 Spherical lens 7a Focus 8 Concave spherical mirror, spherical substrate 9 Concave aspherical mirror, parabolic mirror 9a Metal deposition Thin film 10 Vacuum-tight chamber 20 Mask 20a Masking blade 30 Mask rotation drive mechanism 30a Mask rotation gear 31 Base plate 32 Mask base plate 32a Mask set hole 33 Substrate base plate 33a Substrate set hole 37 Revolution internal gear 38 Revolution external gear 39 Rotation Drive shaft 39a Drive gear 100 Aspherical optical component manufacturing device (manufacturing device)

Claims (5)

An aspherical lens that is disposed on the light path of the concentrating spherical lens and corrects the aberration of the spherical lens,
The aspheric lens has a blocking part and an opening part using a parallel plane substrate and a sputter deposition flow in which atoms are ejected from a target by positive ions generated by ionizing a gas by a high electric field in an airtight chamber. Then, the flow is controlled by a mask that drives the outer periphery thereof and rotated at a constant angular velocity, and is composed of a deposited film that is circularly deposited on the substrate in a centrosymmetric manner,
By making the material of the target transparent, a lens system in which the deposited film is integrated with the substrate is formed,
The film thickness on each circumference of the deposited film is determined by the length of the opening portion for each circumference. Therefore, if the thickness change shape to be obtained in the radial direction is determined, the length of the opening portion for each circumference is determined. , The masking shape is set,
An aspherical optical component, characterized in that the aspherical lens system represents at least a high-order polynomial expression for the film thickness change shape. An aspheric film that corrects the aberration of the spherical reflector is formed on the surface of the concave spherical reflector for condensing or outputting parallel light, and a reflective metal thin film is deposited on the surface to correct the aberration. A spherical parabolic reflector,
The parabolic reflector uses a concave spherical reflector and a sputter deposition flow in which atoms are ejected from a target by positive ions generated by ionizing a gas by a high electric field in an airtight chamber.
The flow is controlled by a mask that has a blocking portion and an opening portion, drives the outer periphery thereof and rotates at a constant angular velocity, and is composed of a deposited film deposited on the concave spherical reflector surface,
When the material of the deposited film is transparent, the reflective metal thin film is provided on the deposited film,
The film thickness on each circumference of the deposited film is determined by the length of the opening portion for each circumference. Therefore, if the thickness change shape to be obtained in the radial direction is determined, the length of the opening portion for each circumference is determined. , The masking shape of the mask is set,
An aspherical optical component, characterized in that the aspherical lens system represents at least a high-order polynomial expression for the film thickness change shape. A manufacturing apparatus for an aspheric optical component (aspheric lens) according to claim 1 and an aspheric optical component (parabolic reflector) according to claim 2,
The manufacturing apparatus includes a holding mechanism that can set M (one or more) parallel plane substrates or concave spherical mirrors that deposit sputter vapor deposition from a target in an airtight chamber to form the aspheric lens, and the parallel plane substrate or Disposed between the concave spherical mirror and the target and rotated at a constant angular velocity for each parallel plane substrate or concave spherical mirror to form an aspheric optical system that corrects aberrations. The ratio of the cut-off portion and the opening portion on each circumference for each distance is determined, and a mask with a masking blade designed to control the sputter deposition flow from the value of the ratio, and the central portion of the parallel plane substrate or the concave spherical mirror In order to make the aspherical film having the film thickness changing shape including the deposited film, the mask is driven by a mask rotation gear provided on the outer periphery of the mask without using the central axis. Aspheric optical component manufacturing apparatus characterized and click periphery drive mechanism, in that it comprises at least. A method for designing a masking blade of a mask used in a manufacturing apparatus for an aspherical part according to claim 3,
In determining the shape of the masking blade that rotates at a constant angular velocity of the mask that is to be deposited on the radial thickness change shape that forms the aspheric optical system that corrects the aberration of the aspheric part,
If the film thickness to be deposited at a position r apart from the center of rotation is d (r) during the time when it is desired to rotate once relative to the angular velocity, it is on the circumference where there is no mask (no blocking part) at the same time. Denote the deposition angle at D, and the opening angle of the arc length L of the opening portion section with respect to the film thickness d (r) on each circumference is represented by θ, the shape of the masking blade is represented by coordinates X, Y X = r cos θ (1), Y = r sin θ (2)
θ = 2πd (r) / D (3)
If the opening angle θ and the coordinates X and Y are calculated from the predetermined film thickness d (r) d (r) using the equations (1) to (3) and calculated for all changes in r. A mask design method for use in a manufacturing apparatus for an aspherical optical component, characterized in that the shape of the opening area of the mask is determined from the locus of the coordinates X and Y, and the masking blade corresponding to the film thickness to be deposited is determined. The arc length L of the opening on the circumference of the radius r is calculated from r · θ, and the arc length L is further divided into n (integer) to arrange a plurality of openings, and a mask. 5. A method for designing a mask used in an apparatus for manufacturing an aspherical optical component according to claim 4, wherein the mask shape of a plurality of masking blades is used to improve the stability during rotation of the aspherical optical component.

Images