JPS6142363A - Apparatus for molding curved surface - Google Patents

Abstract

PURPOSE:To mold not only a curved surface but also a non-spherical surface with high accuracy, by linearily and reciprocally moving a curved surface forming matrix held to a jig in such a state that the molding surface of said matrix crosses the surface of a liquid. CONSTITUTION:A monomolecular film is formed to the surface of the liquid 2 received in the liquid tank 3 of a film forming apparatus 1. A curved surface forming matrix 9 is held to a jig 10 and linearily reciprocated up and down along with the jig 10 through a support shaft 8 in such a state that the surface of the matrix crosses the surface 12 of the liquid in the liquid tank 3. By this method, a curved surface can be molded with high accuracy by the adhesion and accumulation of an ultra-thin film and the molding of a non-spherical surface can also be performed with high accuracy.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to molding of various curved surfaces that require high precision, including optical curved surfaces in lenses, reflecting mirrors, light-receiving elements, light-emitting elements, etc. The present invention relates to a curved surface forming device used.

[Prior Art] Generally, when trying to obtain a curved surface, even when the curved surface is a spherical surface, it is extremely difficult to form the curved surface with high precision, especially when the curved surface is an aspherical surface.

Conventionally, the curved surface of an aspherical lens intended to correct lens aberrations, for example, has been formed by: (1) cutting with a spherical lens cutter, (2) pouring into a mold with a desired aspherical surface, or vapor deposition on a zero-spherical lens. There is.

However, in the case of (2), unevenness occurs depending on the degree of contact with the cutter, so it is necessary to re-polish after cutting, and for this reason, deviation from the set curved surface is unavoidable. ■
In this case, not only is the accuracy of the curved surface of the mold itself a problem, but also the high temperature material (molten glass) is poured and cooled, which may cause distortion due to uneven cooling and non-uniformity of the interface in contact with the mold. ization becomes a problem. In the case of (3), it is not only difficult to apply vapor deposition uniformly to the curved surface, but also the vapor deposition must be performed while gradually shifting the coverage area of the mask according to the desired curved surface condition, making the work complicated and causing errors. Cheap.

As described above, it is extremely difficult to mold a desired curved surface with high precision, and especially in the case of an aspherical surface, considerable errors are unavoidable.

[Problems to be Solved by the Invention] The problem to be solved by the present invention is to enable molding of curved surfaces with high precision even if they are aspherical.

[Means for Solving the Problems] The means taken to solve the above problems in the present invention include a film forming apparatus that forms a monomolecular film on the surface of a liquid contained in a liquid tank; A jig that holds a base material to be molded into a curved surface, and a drive unit that linearly reciprocates the base material held by this jig in a state where the molding surface of the base material and the liquid level intersect. The purpose of the present invention is to provide a curved surface forming device with

] - In the present invention, a conventionally known film forming apparatus can be suitably used, and the monomolecular film formed by this means - an ultra-thin film with a uniform thickness in which molecules are connected in a planar manner. The base material is an object on which a curved surface is to be formed, and is mainly an optical system member such as a lens, a reflecting mirror, a light-receiving element, a light-emitting element, etc., but other materials may also be used. In addition, a state where the molding surface of the base material and the liquid level in the liquid tank of the film forming device intersect means that part of the molding surface of the base material is submerged below the liquid level, and at the same time, part of the molding surface is below the liquid level. This refers to the state in which the material is exposed to the surface.

[Function] When the base material is moved by the drive unit, a certain range of the molding surface of the base material moves up and down with the liquid level as a boundary, depending on the amplitude of this movement. Meanwhile, a monomolecular film is formed on the liquid surface. As the base material moves, this monomolecular film is deposited and accumulated in a meandering pattern on the molding surface of the base material, which is lower than the liquid level. The ability to transfer a monomolecular film onto a smooth surface and to accumulate it is known as the monomolecular accumulation method (Langmuir-Blodgett method), and in the present invention, this method is utilized for forming curved surfaces. That's what I'm doing. In particular, in the present invention, by moving the base material in a state where the molding surface of the base material and the liquid level intersect,
The cumulative range of monomolecular film adhesion can be adjusted by the amount of movement of the base material. Then, by accumulating the monomolecular film while adjusting the cumulative adhesion range and cumulative number of the medium molecular film by the amount of movement and the number of movements of the base material, a monomolecular film with a uniform thickness of -molecules can be applied to the angstrom. It is possible to adjust the curved surface state in units, and it is possible to mold curved surfaces with high precision.

[Example] In FIG. 1, l is a film forming apparatus, and an inner frame 4 made of a material such as polypropylene to which a monomolecular film does not easily adhere is horizontally placed inside a liquid tank 3 containing a liquid 2. This inner frame 4
A film forming frame 5 made of a material to which a monomolecular film does not easily adhere is floated inside. The film forming frame 5 has a width equal to that of the inner frame 4.
It is a rectangular parallelepiped that is slightly shorter than the inner width of the box, and is movable in the left and right directions in the figure.

A drive section 7 attached to a support section 6 is located above the liquid tank 3 on the left side in the figure. A support shaft 8 is suspended from the drive unit 7, and a jig lO for holding the base material 9 is attached to the tip of the support shaft 8.
is installed.

As shown in FIG. 2, the jig IO is screwed onto the tip of the support shaft 8 and can be replaced depending on the base material 9. This jig J410 has claws 11 on all sides of the lower end, and the base material 9 is held by hooking the peripheral edge of the base material 9 onto the claws IN-. Beat AlO
The claws 11 may be provided not only on the four sides as shown in FIG. 2, but also all around the circumference.Also, as shown in FIG. 3, if the claws 11 are thin and short, they will not get in the way. Furthermore, as shown in FIG. 4, if the claw part 11 is supported by the bottle 13, the area where the jig JLIO cuts the liquid surface can be reduced when the jig 10 is moved by the drive part 7, which will be described later. It is preferable to bend the bottle 13 outward, since this can suppress disturbance of the monomolecular film on the liquid surface 121.
The position where the jig 10 cuts the liquid level 12 is farther away from the base material 9,
11 The influence of lO on the monomolecular film extends to the base material 9.
<It is preferable because it can be done.

On the other hand, the drive unit 7 shown in FIG. Jig 1 via support shaft 8
For example, when molding a curved surface on the lower surface of the base material 9, the liquid level 12 moves upward and downward with the base material as indicated by the symbol I in FIG. 2(a). The base material 9 is reciprocated downward while intersecting the lower surface of the base material 9.

In addition, when molding the two curved surfaces of the base material 9, the second
As shown by the symbol ■ in Figure (a), the liquid level 12 is lower than the base material 9.
The base material 9 is reciprocated up and down while intersecting the upper surface of the base material 9. The movement of the base material 9 by the drive unit 7 is not limited to the vertical direction, but may be in the oblique direction.

The liquid 2 contained in the liquid tank 3 is usually pure water, and this liquid level 1
2, move the film forming frame 5 to the right side of Figure 1 and drop a few drops of a solution of the film constituent material dissolved in a volatile solvent such as benzene or chloroform onto the liquid surface 12 using a dropper or the like. As the membrane-constituting substance, a substance composed of molecules having at least a hydrophobic part and a hydrophilic part in the same chemical structure is usually used. A common aqueous moiety is, for example, a long chain alkyl group having about 5 to 30 carbon atoms, and a common hydrophilic moiety is a polar group such as a carboxyl group or an amino group. Specific examples of membrane constituent substances include alaxic acid and the like.

-1- A solution of the film-forming substance is dropped onto the liquid surface, and when the solvent evaporates, a monomolecular film in the form of a gaseous film is left on the liquid surface.Next, the film forming frame 5 is placed on the left side of Figure 1. When the liquid surface 12 where the intermediate molecular film is developed is moved and the area of the liquid surface 12 where the middle molecular film is developed is gradually reduced to increase the surface density, the interaction between molecules is strengthened, and the state changes from a liquid film state to a solid film. Then, when this solid film state is reached, the base material 9 is rotated by the drive unit 7 as described above.
- The monomolecular film is deposited and accumulated on the surface of the base material 9 by reciprocating downward movement to form a curved surface. The optimal state of the monomolecular film to be transferred to the base material 9 is when the surface pressure of the monomolecular film is 15 to 30 d.
As a rough guide, we can know that yn/c ■.As the 0m molecular film is accumulated on the base material 9, the areal density of the monomolecular film molecules at the liquid level 12J- decreases, and the surface pressure also decreases. Therefore, the monomolecular film is transferred to the base material 9 by gradually moving the molding frame 5 and keeping the surface pressure constant. Also, the moving speed of the base material 9 is such that the monomolecular film is not disturbed. In order to ensure that the adhesion can be accumulated without any problems, it is preferable to set the speed to less than IC2 per minute.

Next, the accumulation process of adhesion of the monomolecular film to the base material 9 will be explained with reference to FIG.

First, when the base material 9 is moved upward in a state where the molding surface of the base material 9 and the liquid level 12 intersect as shown in FIG. 5(a),
(The same is true even if the monomolecular film A is moved downward), and as shown in FIG. After moving the base material 9 upward by a predetermined amount, when the base material 9 is moved downward while maintaining the intersection between the molding surface of the base material 9 and the liquid level 12,
As shown in FIG. 5(C), the monomolecular film A is deposited in an overlapping manner on the monolayer 1111A deposited on the surface of the base material 9 in the previous stage, and the vertical movement of this base material 9 is repeated. As a result, the single molecules 11A are deposited one after another on the surface of the base material 9 in a meandering manner, as shown in FIG.

When the base material 9 is a spherical lens, if the monomolecular film is deposited and accumulated as described above, the monomolecular film will be deposited and accumulated in the area shown by diagonal lines in FIG. The width of this doughnut-shaped intermediate molecular film adhesion cumulative range is determined by the amount of downward movement of the base material 9, and the adhesion thickness of the monomolecular film is determined by the number of adhering layers of the monomolecular film, that is, the base material 9. It is determined by the number of movements.

Therefore, if the monomolecular film is deposited and accumulated while adjusting the movement amount and number of movements of the base material 9 by the drive unit 7 (see Fig. 1), the monomolecular film can be deposited while changing the adhesion thickness within an arbitrary range. It can be accumulated and, for example, a spherical lens can be easily molded into an aspherical lens.

When accumulating the attachment of a monomolecular film to the base material 9, if the base material 9 is brought into the state shown in FIG. A monomolecular film is attached to a portion, for example, the central portion of the base material 9 shown in FIG. 6, although it is only one layer. In order to prevent this, first set the base material 9 in a state where the molding surface of the base material 9 and the liquid level 12 intersect, as shown in FIG. 5(a), and then
It is sufficient to form a monomolecular film on the liquid surface 12. However, since the monomolecular film is extremely thin and even if one or two layers are attached, it can be ignored as a curved surface state, so there is no need to do this. Also, if the film constituent material is a substance that causes a polymerization reaction when irradiated with ultraviolet rays, such as diacetylene, and the monomolecular film is deposited and accumulated on the base material 9 as described above, and then polymerized, This is preferable because the state of adhesion of the monomolecular film to the base material 9 becomes stronger and more stable.

The movement of the base material 9 by the drive unit 7 in the present invention is not limited to the linear up-and-down reciprocating movement described above, but may also include rotation around the central axis of the base material 9, or reciprocation of the base material 9. It can be applied in addition to tilting motion.

In the case of only the linear up and down reciprocating movement described so far, if the base material 9 is, for example, a spherical lens, the base material 9 moves at a constant speed.
Even if the molding surface of the base material 9 is curved,
The speed of movement at the intersection with the liquid level 12 on the surface of the base material 9 will change. Therefore, the speed at which the monomolecular film is transferred to the base material 9 changes depending on the surface position of the base material 9. On the other hand, if the base material 9 is rotated around the central axis at the same time as the vertical and linear reciprocating movement, the monomolecular film will be spirally wrapped around the surface of the base material 9, and the -L downward movement will occur. By keeping the speed and the rotational speed constant, the rate at which the monomolecular film is transferred to the base material 9 can be kept constant. Therefore, there is an advantage that the properties of the monomolecular film accumulated on the base material 9 can be easily made uniform.

On the other hand, as shown in FIG. 7, the surface of the base material 9 and the liquid level 1
When the base material 9 is tilted back and forth in a state in which the two lenses intersect, for example, if the base material 9 is a spherical lens, the monomolecular film will be deposited and accumulated in the area shown by diagonal lines in FIG. This eighth
The lateral width of the monomolecular adhesion accumulation range shown in the figure can be adjusted by the amount of tilting of the base material 9, and the adhesion thickness of the monomolecular film can be adjusted by the number of times of tilting. If such a reciprocating tilting movement of the base material 9 is combined with an up-and-down linear reciprocating movement and a monomolecular film is deposited and accumulated, it is possible to easily obtain a rotationally asymmetric aspherical lens such as a bifocal lens through this molding. can. Furthermore, if the above-mentioned rotation is applied continuously or intermittently along with this tilting, the accumulated state of adhesion of the middle molecular film can be adjusted more delicately. Further, when the base material 9 is a lens, the center of tilting of the base material 9 is usually set on the optical axis of the lens, but asymmetric molding can also be performed by setting the center of tilting off the optical axis.

FIG. 9 is a diagram showing another embodiment, in which the support shaft 8 connected to the drive unit 7 extends below the liquid level 12.
A jig IO is attached to the tip of the support shaft 8 located below, facing upward. As shown in FIG. 1O, this jig 10 has a base material 9 held by placing the base material 9 on its claws It. This embodiment is the same as the previous embodiment except that the material 9 is moved from below the liquid level 12, and the same effects can be obtained.

FIGS. 11 and 12 also show other embodiments, in which molding can be carried out while monitoring the state of the molded curved surface. That is, the parallel light emitted from the collimated light source 14 travels in the direction shown by the arrow in the figure, and first hits the mirror 1.
After the direction is changed at 5a, the beam is separated into a reference beam and a measurement beam by a /\-fumirror 18. The reference light is reflected by the mirror 15b again to the eight-beam mirror 16, further reflected by the half mirror 18, and sent to the interference fringe reading device 17. On the other hand, the measurement light is sent to the mirror 15c, reflected there, and sent to the surface of the base material 9 on the jig 10 through the reference lens 18. The measurement light reflected on the surface of the base material 9 is sent through the reference lens 18 and the mirror 15c again to the interference fringe reading device, and the surface state of the base material 9 is detected from the state of interference with the reference light. Therefore, while detecting the surface condition of the base material 9, the base material 9 can be moved in accordance with the detection result to deposit and accumulate the monomolecular film, making the work accurate and efficient. Note that the support shaft 8 in this embodiment
is moved up and down along the support section 6 by a drive section (not shown).

In the above description, half mirror 1B and mirror 15
Although the reference light is formed in step b, the reflected light from the reference lens 18 may also be used as the reference light.Also, the surface condition of the base material 9 can be detected when the surface of the base material 9 to be detected is on the liquid level 12. Although this measurement is performed at a certain time, it is also possible to set the measurement position in advance and automatically perform the measurement when the base material 9 is moved to the position as the base material 9 moves. Further, based on this measurement result, the movement of the base material 9 can be controlled by a computer or the like.

[Effects of the Invention] According to the present invention, a curved surface can be formed by the accumulation of an angstrom-order ultra-thin film called a monomolecular film, and the adhesion range and cumulative number of layers of this monomolecular film can be freely adjusted, so that it can be formed with high precision. It can mold curved surfaces and can also mold aspherical surfaces with high precision.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of an embodiment of the present invention, Fig. 2 is an enlarged view of the jig, (a) is a longitudinal cross-sectional view, (b) is a bottom view, and Figs. 3 and 4 are each a jig. A vertical cross-sectional view showing another example of the tool, FIGS. 5(a) to 5(d) are explanatory diagrams of the monomolecular film adhesion accumulation process, FIG. 6 is a diagram showing the monomolecular film adhesion accumulation range, and FIG. 7 Diagram (a)
~(c) is a diagram showing the tilting state of the base material, the wIJB diagram is a diagram showing the cumulative adhesion range of the monomolecular film, Figure 9 is a schematic diagram of another embodiment of the present invention, and Figure 1θ is the jig. FIG. 11 is a schematic view of still another embodiment of the present invention, and FIG. 12 is an enlarged view of the vicinity of the base material. 1: Film forming apparatus, 2: Liquid, 3: Liquid tank, 7: Drive unit, 9: Base material, lO: #tJL.

Claims (1)

[Claims] 1) A film forming device that forms a monomolecular film on the surface of a liquid contained in a liquid tank, a jig that holds a base material on which a curved surface is to be formed, and a base material held in this jig, A curved surface forming apparatus comprising: a drive unit that linearly reciprocates in a state where the forming surface of the base material and the liquid surface intersect with each other.