Method for manufacturing an optical element, apparatus for manufacturing an optical element, optical element, optical instrument equipped with an optical element, control method and control program

Abstract

To improve coating quality (coating condition). [Solution] A method for manufacturing an optical element by applying paint to the side surface of a lens, comprising the steps of: forming a first layer of paint by bringing an elastic body into contact with the crack on the side surface, thereby allowing the paint to penetrate the crack; and applying paint to the first layer to form a second layer of paint.

Description

Technical Field

[0001] The present invention relates to an optical element.

Background Art

[0002] When incident light on an optical element used in an optical device such as a camera or a semiconductor exposure apparatus causes surface reflection or internal reflection, stray light is generated. This stray light causes flare and ghost, and deteriorates the optical performance of the optical device. In order to suppress surface reflection and internal reflection, it is known to form a light-shielding film by applying a light-shielding paint for anti-reflection to the side surface or chamfer of the optical element. Conventionally, as a method of applying a light-shielding paint to an optical element, a method of manually applying the paint by pressing a pen or brush impregnated with the light-shielding paint against the desired part of the optical element by an operator has been common. In Patent Document 1, as a coating method for automating the manual coating using a pen or brush, a method of rotating a centered optical element, moving a jet dispenser along the outer peripheral shape of the optical element, and automatically coating the side surface and chamfer with a light-shielding paint is disclosed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Here, due to the presence of minute cracks caused by grinding or differences in machining or cleaning methods in the pre-process of applying the light-shielding paint, the surface wettability of the optical element may vary. Therefore, the size of droplets landed on the optical element by a jet dispenser may vary. As a result, there is a problem that coating film omission may occur due to insufficient connection of the droplets, and the coating quality (coating state) may deteriorate. [Means for solving the problem]

[0005] The present invention provides a method for manufacturing an optical element by applying paint to the side surface of a lens, characterized by comprising the steps of: forming a first layer of paint by bringing an elastic body into contact with the cracks on the side surface, thereby allowing the paint to penetrate the cracks; and applying the paint to the first layer to form a second layer of paint. [Effects of the Invention]

[0006] According to the present invention, the coating quality (coating state) can be improved. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic side view showing the optical element in the embodiment. [Figure 2] A schematic diagram showing the coating apparatus 100 in an embodiment. [Figure 3] This is a schematic side view showing the light-shielding film 2 in the embodiment. [Figure 4] This figure shows the state of the coating process in the embodiment. [Figure 5] This is a control flowchart in the embodiment. [Figure 6] This is a schematic cross-sectional view showing the optical element when the first layer in the embodiment is formed. [Figure 7] This is a schematic side view showing the means for measuring paint film peeling in the embodiment. [Figure 8] This is a schematic diagram showing whether or not there is paint film peeling in the embodiment. [Modes for carrying out the invention]

[0008] The embodiments for carrying out the present invention will be described below with reference to the examples shown in the attached drawings. Note that the embodiments described below are merely examples, and for example, the detailed configuration can be appropriately modified by those skilled in the art without departing from the spirit of the present invention. Furthermore, the numerical values ​​mentioned in these embodiments are for reference only and do not limit the present invention. In the following drawings, the arrows X, Y, and Z indicate the overall coordinate system of the system. Generally, the XYZ 3D coordinate system represents the world coordinate system of the entire installation environment. In addition, a local coordinate system may be used as appropriate for control purposes, etc.

[0009] (Embodiment) (Optical element with a light-shielding film) Figure 1 is a schematic side view of the optical element in this embodiment. As shown in Figure 1, the optical element in this embodiment has a light-shielding film 2 provided on a lens 1. The lens 1 has an optical surface 1a and a machined end surface 1b, and a chamfered surface 1c is provided between the optical surface 1a and the end surface 1b. The light-shielding film 2 is provided on the end surface 1b. It is preferable that the light-shielding film 2 on the end surface 1b has a desired width and a uniform film thickness.

[0010] (Appliance equipment for coating paints) Figure 2 is a schematic diagram showing a coating apparatus 100 used in the manufacturing method of an optical element in this embodiment. In Figure 2, the lens 1 to be coated is placed on the suction stage 3, and the lens 1 is held in place by a vacuum pump (not shown). The suction stage 3 is connected to a lens rotation motor 4 and rotates at a desired rotational speed. The lens rotation motor 4 is connected to a Y-axis stage 5, which can move the lens 1 to the dispensing / removal position or the coating position.

[0011] The jet dispenser 6 is connected to a Z-axis stage 8 to which an X-axis stage 7 is attached, allowing it to be driven to a desired position relative to the lens 1. The jet dispenser 6 can change its dispensing frequency and dispensing rate using a control device (not shown).

[0012] The elastic body 9 is wound around the feed member 10 to a predetermined length and is routed from the feed member 10 to the winding member 12 via the support member 14. The tension of the elastic body 9 is determined by controlling the torque of a rotary motor 13 connected to the feed member 10 and the winding member 12 using a control device (not shown) so that the value of a tension sensor (not shown) falls within a desired range and the tension is predetermined. By rotating the rotary motor 13 at a predetermined angle, the predetermined length of the elastic body 9 wound around the feed member 10 can be fed to the winding member 12.

[0013] The feed member 10 and the winding member 12 are fixed to the support member 14. The support member 14 is connected to the Z-axis stage 16 to which the Y-axis stage 15 is attached, allowing the elastic body 9 to contact the lens 1 at a desired position. The elastic body 9 may also be tilted in the tangential direction of the lens 1 by a rotation mechanism (not shown). The material of the elastic body 9 is not particularly limited, as long as it is resistant to the coating paint 17. It may be a resin such as nylon, or a metal such as stainless steel or copper.

[0014] The control unit (not shown) that controls each mechanism of the coating apparatus is composed of a computer. The control unit has a CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory). It also includes a communication interface (hereinafter referred to as "I / F"). The CPU, which is a processor, is an example of a control unit. The ROM stores the program. The program is a program that causes the computer, i.e., the CPU, to execute the output of commands for controlling each mechanism. RAM is used to temporarily store data such as the program for executing control of the entire system, the execution timing of operations for each controlled object, and control commands.

[0015] The CPU acquires data by receiving, via the I / F, data transmitted from sensors provided in each mechanism. Further, the CPU may transmit, via the I / F, a command as a control target value to another control device that controls each control target based on a program and data input by the user. Each mechanism is equipped with a control device composed of a computer including a microprocessor or the like. Then, the main control device outputs commands to each control device, and the actual control may be executed by the sub-control devices mounted on each device. That is, the control of the coating device 100 may be executed by at least one control device. Also, the control of each mechanism may be executed only by the main control device. In the communication between the main control device and the sub-control targets and control devices, wired communication or wireless communication may be used.

[0016] Note that in this embodiment, the program is recorded in the ROM, but it is not limited thereto. The program may be recorded in any recording medium as long as it is a non-temporary recording medium readable by a computer. As a recording medium for supplying the program to the computer, for example, a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a magnetic tape, a non-volatile memory, etc. can be used.

[0017] Thus, by performing the step of applying the light-shielding film 2 to the lens 1, it becomes possible to undertake part of the manufacture of an article. By executing the process of applying the coating paint 17 for forming the light-shielding film 2, it becomes possible to manufacture the lens 1 with the light-shielding film 2 applied as a product. Also, by executing the process of assembling the lens 1 with the light-shielding film 2 into another component, it becomes possible to manufacture a product in which the lens 1 with the light-shielding film 2 applied and another component are assembled. Therefore, the coating device 100 functions as a manufacturing device.

[0018] FIG. 3 is a schematic side view showing the coating range of the coating paint according to the present embodiment. FIG. 4 is a view showing the state of the coating process in the present embodiment. FIG. 5 is a control flowchart for performing coating in the present embodiment. Note that the control flowchart shown in FIG. 5 is executed by the CPU of each control device in cooperation through communication and / or in cooperation with the work by an operator. As shown in FIGS. 3 and 4, the coating paint 17 is applied to a width of about 5 mm from the ridge line of the chamfered surface 1c of the lens 1. The lens 1 has a shape of Φ100 mm and a thickness of 20 mm.

[0019] From FIG. 5, first, in step S1, before applying the coating paint 17 to the side surface of the lens 1, alignment is performed between the lens 1 and the center of the rotation axis of the suction table 3. While rotating the lens 1, the distance between the side surface of the lens 1 and the laser displacement meter is measured by a fixed laser displacement meter (not shown), and the position of the lens 1 is adjusted so that the alignment accuracy is ±100 μm or less.

[0020] Next, in step S2, the lens 1 is vacuum-sucked and held with respect to the suction table 3.

[0021] Next, in step S3, with the discharge port of the jet dispenser 6 fixed horizontally with respect to the rotation axis of the lens 1 by a rotation motor (not shown), the X-axis stage 7 and the Z-axis stage 8 are driven. Then, the jet dispenser 6 is brought close to a predetermined position with respect to the lens 1.

[0022] Next, in step S4, the Y-axis stage 15 and the Z-axis stage 16 are driven to bring the elastic body 9 into contact with the side surface of the lens 1.

[0023] Next, in step S5, with the lens 1 rotated by the lens rotation motor 4, as shown in FIG. 4, the coating paint 17 is applied to the side surface of the lens 1. After the coating paint 17 is discharged from the jet dispenser 6 and landed on the lens 1, the coating paint 17 moved by the rotation of the lens 1 is brought into contact with the elastic body 9 to spread the coating paint 17 (FIG. 4(a)). In FIG. 4(a), for convenience of explanation, the elastic body 9 is emphasized and shown.

[0024] Here, Figure 6 is a schematic cross-sectional view of the lens 1 when the first layer according to this embodiment is formed. When the coating paint 17 is spread by the elastic body 9, the coating paint 17 penetrates and fills the cracks 19 present on the side surface of the lens 1, as shown in Figure 6. This process is repeated after continuously dispensing the coating paint 17 from the jet dispenser 6 to coat the lens once, then moving the position of the jet dispenser 6 in the Z-axis direction and coating the lens once more, until a predetermined width is formed, thereby forming the first layer of coating paint 17.

[0025] Here, since the elastic body 9 scrapes off a certain amount of the coating paint 17, forming only the first layer may result in a thickness thinner than the predetermined thickness. Therefore, after forming the first layer, in step S6, the elastic body 9 is separated from the side surface of the lens 1. Then, in step S7, the coating paint 17 is continuously dispensed from the jet dispenser 6 onto the first layer to coat it around once, and then the position of the jet dispenser 6 is moved in the Z-axis direction and the coating is applied around once again. This process is repeated until a predetermined width is formed (Figure 4(b)). This forms the second layer of coating paint 17. In this embodiment, the coating paint 17 is applied to the lens 1 by rotating the lens 1, but this is not the only method. For example, the coating paint 17 may be applied to the lens 1 by rotating the jet dispenser 6 and the elastic body 11 relative to the lens 1.

[0026] This concludes the control flow for the coating 17 applied to the lens 1. In order to compare and evaluate the coating state of the coating 17 in this embodiment, the coating methods shown in Comparative Example 1 and Comparative Example 2 were performed. In this embodiment, Comparative Example 1, and Comparative Example 2, the coating state was measured using the following measurement methods.

[0027] (Evaluation of whether or not the paint film has peeled off) Figure 7 is a schematic side view showing the means for measuring paint film defects in this embodiment. As shown in Figure 7, a CCD camera 18 is installed on the side of a lens 1 on which a light-shielding film 2 is formed, and the coated paint 17 applied to the side of the lens 1 is photographed while the lens 1 is rotated. If the density of the coated paint 17 in the captured image is uniform to the naked eye, it is determined that there are no paint film defects. However, as shown in Figure 8, if there is a difference in the density of the coated paint 17 to the naked eye, it is determined that there are paint film defects.

[0028] (Measurement of film thickness of coated paint 17) Next, using a high-speed, high-precision white light interferometer (NEWVIEW6300 Zygo), the thickness of the coating 17 applied to the side surface of the lens 1 was measured from the difference in the cross-sectional profile of the coating 17 before and after application.

[0029] (Application method of Comparative Example 1) In the coating method of Comparative Example 1, the coating paint 17 on the side surface of the lens 1 was applied using only the jet dispenser 6, without using the elastic body 9. After continuously dispensing the coating paint 17 from the jet dispenser 6 while rotating the lens 1 to coat it around the entire surface, the position of the jet dispenser 6 was moved in the Z-axis direction and the coating was applied around the entire surface again. This process was repeated until a predetermined width was formed.

[0030] (Application method of Comparative Example 2) In the coating method of Comparative Example 2, only the first layer shown in Figure 4(a) was formed when applying the coating paint 17 to the side surface of the lens 1. The formation of the first layer was carried out under the same conditions as in the embodiment.

[0031] Table 1 shows the results regarding the presence or absence of coating defects in the embodiment, comparative example 1, and comparative example 2. The contact angle of the side surface of lens 1 is the result of using pure water. The cracks 19 present on the side surface of lens 1 affect the contact angle of the side surface of lens 1, and by checking the presence or absence of coating defects at the contact angle of the side surface of lens 1, it is possible to determine whether the coating paint 17 has filled the cracks 19. For example, if there are no coating defects, it can be assumed that the coating paint 17 has filled the cracks 19.

[0032] [Table 1]

[0033] Table 1 shows that in Comparative Example 1, coating peeling occurred when the contact angle of the side surface of lens 1 was 26.9 degrees or more. In the Embodiment and Comparative Example 2, it can be seen that coating peeling did not occur even when the contact angle of the side surface of lens 1 was 50 degrees. When forming the first layer, the coating paint 17 is spread by the elastic body 9, and the coating paint 17 penetrates into the cracks 19 present on the side surface of lens 1, filling them and preventing coating peeling. From the above, it was found that the Embodiment and Comparative Example 2 are useful as coating methods to suppress coating peeling in the Embodiment, Comparative Example 1 and Comparative Example 2. Next, the film thickness in the coating methods of Embodiment 1 and Comparative Example 2 was evaluated.

[0034] Next, Table 2 shows the results of whether the film thickness in the embodiment and comparative example 2 is within the predetermined range.

[0035] [Table 2]

[0036] Table 2 shows that in the embodiment, a film thickness within a predetermined range can be formed, while in Comparative Example 2, a film thickness within a predetermined range could not be formed. Therefore, the coating method of the embodiment allows for control of the film thickness by applying the coating paint 17 onto the first layer using the jet dispenser 6, thereby enabling the formation of a desired film thickness. The film thickness can be adjusted by adjusting the amount of coating paint 17 discharged from the jet dispenser 6 and the pitch between the coating paint 17 droplets that land on the side surface of the lens 1.

[0037] As described above, according to this embodiment, a first layer of paint is formed to penetrate the cracks in the lens 1 and fill the cracks with paint, and a second layer of paint having a predetermined thickness is formed on the first layer. As a result, the first layer reduces coating gaps, and the second layer makes it possible to form a predetermined thickness. Thus, a coating film of a predetermined thickness with reduced coating gaps can be formed on the optical member, and the coating condition can be improved.

[0038] (Other embodiments) The processing procedures of the embodiments described above are specifically executed by at least one CPU of each control device. Therefore, it is also possible to configure the device to read and execute a recording medium on which a control program of software capable of executing the above-described functions is recorded. In this case, the control program read from the recording medium itself will realize the functions of each embodiment described above, and the control program itself and the recording medium on which the control program is recorded will constitute the present invention.

[0039] Furthermore, in each embodiment, the computer-readable recording medium was described as a ROM, RAM, or flash ROM, and the program was stored in the ROM, RAM, or flash ROM. However, the present invention is not limited to these embodiments. The program for carrying out the present invention may be recorded on any recording medium that is computer-readable, and may be recorded on an SSD (Solid State Drive), etc.

[0040] Furthermore, in the various embodiments described above, the jet dispenser 6 was moved on a stage or the like, but it is not limited to this, and the jet dispenser may be moved using a robot. As the robot, different types of joints such as horizontal articulated robots, parallel link robots, and Cartesian robots can be used. In addition, the various embodiments described above can be applied to machines that can automatically perform movements such as extension and retraction, bending and straightening, vertical movement, horizontal movement, or rotation, or combinations thereof, based on information stored in a memory device provided in the control device. Furthermore, the optical elements in the various embodiments described above can be applied to optical equipment such as video cameras, digital still cameras, and semiconductor exposure equipment, which can be used for various applications such as in-vehicle use and in mobile devices such as drones. In addition, although a light-shielding film is used as an example in this embodiment, it is not limited to this, and a coating film using a coating paint used for optical elements, such as a heat-shielding film, may be formed.

[0041] Furthermore, the present invention is not limited to the embodiments described above, and many modifications are possible within the technical concept of the present invention. In addition, the effects described in the embodiments of the present invention are merely a list of the most preferred effects that result from the present invention, and the effects of the present invention are not limited to those described in the embodiments. Moreover, the various embodiments and modifications described above may be combined and implemented.

[0042] Furthermore, the disclosure of this embodiment includes the following configurations and methods.

[0043] (Item 1) A method for manufacturing optical elements, which involves applying paint to the side surface of a lens to produce an optical element, The process involves forming a first layer of paint on the side surface by bringing an elastic body into contact with the crack on the side surface, thereby allowing the paint to penetrate the crack. The process involves applying the paint to the first layer to form a second layer of the paint, A manufacturing method characterized by having the following features.

[0044] (Item 2) In the manufacturing method described in item 1, The second layer is formed on the first layer by dispensing the paint from a jet dispenser. A manufacturing method characterized by the following features.

[0045] (Item 3) In the manufacturing method described in item 2, The jet dispenser is used to form the second layer having a predetermined thickness on the first layer. A manufacturing method characterized by the following features.

[0046] (Item 4) In the manufacturing method described in any one of items 1 to 3, The elastic body spreads the paint applied to the side surface, thereby allowing the paint to penetrate the crack. A manufacturing method characterized by the following features.

[0047] (Item 5) In the manufacturing method described in any one of items 1 to 4, The material of the elastic body is one of nylon, stainless steel, or copper. A manufacturing method characterized by the following features.

[0048] (Item 6) In the manufacturing method described in any one of items 1 to 5, With a predetermined tension generated in the elastic body, the paint is allowed to penetrate the crack using the elastic body. A manufacturing method characterized by the following features.

[0049] (Item 7) A control program that enables a computer to execute the manufacturing method described in any one of items 1 to 6.

[0050] (Item 8) A computer-readable recording medium containing the control program described in item 7.

[0051] (Item 9) An optical element manufacturing apparatus for manufacturing optical elements by applying paint to the side surface of a lens, By bringing an elastic body into contact with the crack on the side surface, the paint is allowed to penetrate the crack, forming a first layer of the paint on the side surface. The paint is applied to the first layer to form a second layer of the paint. A manufacturing apparatus characterized by the following features.

[0052] (Item 10) An optical element in which paint is applied to the side surface of the lens, The first layer of paint that has penetrated the cracks on the side, The first layer comprises a second layer of the coating having a predetermined film thickness, An optical element characterized by having

[0053] (Item 11) An optical instrument equipped with the optical elements described in item 10. [Explanation of Symbols]

[0054] 1 lens 1a Optical surface 1b End face 1c Chamfered surface 2. Light-shielding film 3 Suction table 4. Lens rotation motor 5 Y-axis stage 6 Jet Dispenser 7 X-axis stage 8 Z-axis stage 9 Elastic body 10 Feed member 11 Support member 12 Winding member 13 Rotation motor 14 Support Member 15 Y-Drive Stage 16 Z-axis stage 17 Coating paints 18 CCD cameras 19 Crack 100 Coating device

Claims

1. A method for manufacturing optical elements, which involves applying paint to the side surface of a lens to produce an optical element, The process involves forming a first layer of paint by bringing an elastic body into contact with the crack on the side surface, thereby allowing the paint to penetrate the crack; The process involves applying the paint to the first layer to form a second layer of the paint, A manufacturing method characterized by having the following features.

2. In the manufacturing method described in claim 1, The second layer is formed on the first layer by dispensing the paint from a jet dispenser. A manufacturing method characterized by the following features.

3. In the manufacturing method described in claim 2, The jet dispenser is used to form the second layer having a predetermined thickness on the first layer. A manufacturing method characterized by the following features.

4. In the manufacturing method described in claim 1, The elastic body spreads the paint applied to the side surface, thereby allowing the paint to penetrate the crack. A manufacturing method characterized by the following features.

5. In the manufacturing method described in claim 1, The material of the elastic body is one of nylon, stainless steel, or copper. A manufacturing method characterized by the following features.

6. In the manufacturing method described in claim 1, With a predetermined tension generated in the elastic body, the paint is allowed to penetrate the crack using the elastic body. A manufacturing method characterized by the following features.

7. A control program that enables a computer to execute the manufacturing method described in any one of claims 1 to 6.

8. A computer-readable recording medium storing the control program described in claim 7.

9. An optical element manufacturing apparatus for manufacturing optical elements by applying paint to the side surface of a lens, By bringing an elastic body into contact with the crack on the side surface, the paint is allowed to penetrate the crack, thereby forming a first layer of the paint. The paint is applied to the first layer to form a second layer of the paint. A manufacturing apparatus characterized by the following features.

10. An optical element in which paint is applied to the side surface of the lens, The first layer of paint that has penetrated the cracks on the side, The first layer is a second layer of the coating having a predetermined film thickness, An optical element characterized by having

11. An optical device comprising the optical element described in claim 10.

Images