Test Method

Abstract

To provide a test method capable of evaluating the resistance to scratches on a surface of a coated lens without visual inspection.SOLUTION: In a first embodiment of the present invention, there is provided a test method for evaluating the resistance to scratches on a membrane of an ocular lens. The test method may include scratching the membrane with a constant load applied to a needle. The test method may include measuring a friction force while scratching the membrane. In the test method, if the variation of the friction force in one-time scratching is smaller than a specified value, the load applied to the needle may be increased, and the membrane may be scratched again to measure the friction force. The test method may be repeated by scratching the membrane and measuring the friction force at that time until the variation of the friction force in one-time scratching exceeds a specified value.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a test method By law Regarding. [Background technology]

[0002] Patent Document 1 relates to a method for determining the scratch susceptibility of a functional film that is intended to be attached to the surface of a display device, such as the face of a cathode ray tube, etc. Patent Document 1 describes that the scratch susceptibility of a functional film can be determined in detail. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-185553 Summary of the Invention [Problem to be solved by the invention]

[0004] The test method described in Patent Document 1 requires visual inspection in order to determine susceptibility to scratches. [Means for solving the problem]

[0005] A first aspect of the present invention provides a test method for evaluating the scratch resistance of an ophthalmic lens film. The test method may include scratching the film by applying a constant load to a needle. The test method may include measuring the frictional force while scratching the film. If the variation in frictional force in a single scratch is smaller than a specific value, the test method may increase the load applied to the needle, scratch the film again, and measure the frictional force. The test method may repeat scratching the film and measuring the frictional force until the variation in frictional force in a single scratch exceeds a specific value.

[0008] The above summary of the invention does not list all of the necessary features of the present invention, and subcombinations of these features may also constitute inventions. [Brief explanation of the drawings]

[0009] [Figure 1] 1 shows a schematic diagram of an example of a resistance evaluation system RES. [Figure 2] 2 shows a schematic diagram of an example of the configuration of a computer 200. [Figure 3] 10 is a schematic diagram showing an example of the procedure of a test method for evaluating the scratch resistance of a film of an ophthalmic lens OL using a resistance evaluation system RES. [Figure 4] 10A and 10B are schematic diagrams illustrating an example of a procedure for scratching the film of an ophthalmic lens OL with a needle SN. [Figure 5] 10A and 10B are schematic diagrams illustrating an example of a procedure for scratching the film of an ophthalmic lens OL with a needle SN. [Figure 6] 10A and 10B are schematic diagrams illustrating an example of a procedure for scratching the film of an ophthalmic lens OL with a needle SN. [Figure 7] 10A and 10B are schematic diagrams illustrating an example of a procedure for scratching the film of an ophthalmic lens OL with a needle SN. [Figure 8] 10 is a schematic diagram showing an example of the relationship between the measured value of the friction force and the moving distance of the needle SN. [Figure 9] 10 is a schematic diagram showing an example of the relationship between the measured value of the friction force and the moving distance of the needle SN. [Figure 10] 4 shows test results for measuring the variation in friction force in the examples. [Figure 11] 4 shows test results for measuring the variation in friction force in the examples. [Figure 12] 4 shows test results for measuring the variation in friction force in the examples. [Figure 13] 4 shows test results for measuring the variation in friction force in the examples. [Figure 14] 4 shows test results for measuring the variation in friction force in the examples. [Figure 15] 1 shows test results for measuring variations in frictional force between the example and the comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be described below through embodiments of the invention, but the following embodiments do not limit the scope of the invention according to the claims. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0011] FIG. 1 schematically shows an example of a resistance evaluation system RES. The resistance evaluation system RES is a system used by a tester who performs a test to evaluate the resistance of a film of an ophthalmic lens OL to scratches. The ophthalmic lens OL is a lens used for at least one of measurement, correction, and protection of the eye. The ophthalmic lens OL is used as a spectacle lens worn in front of the eye without contacting the eyeball.

[0012] The resistance evaluation system RES includes a friction tester 100 and a computer 200. In the description of this embodiment, as shown in Fig. 1, the extension direction of the axis AX of the needle SN may be defined as the Z direction, and the plane perpendicular to the Z axis may be defined as the XY plane. The XYZ axes form a right-handed system.

[0013] The friction tester 100 is a device that rubs a test piece against a mating material and measures the friction force that occurs when the test piece rubs against the mating material. The friction tester 100 includes a sample table 110, an orthogonal balance arm 120, and a support portion .

[0014] The sample table 110 is a member on which a test piece is attached, and includes an X-direction stage 111, a jig 112, and an X-direction drive unit 113.

[0015] The X-direction stage 111 is a stage for adjusting the position of the sample table 110 in the X direction. The X-direction stage 111 is provided on the upper surface of the base BU of the friction tester 100 so as to be movable in the X direction.

[0016] The jig 112 is a device that fixes the test piece on the sample table 100. The jig 112 is provided on the upper surface of the X-direction stage 111 so as to be movable in a direction away from the test piece in the XY plane and a direction toward the test piece in the XY plane. For example, the jig 112 fixes the test piece by clamping the sides of the test piece. In this example, the jig 112 fixes an ophthalmic lens OL as the test piece.

[0017] The X driver 113 is a mechanical element constituting the sample table 110 that converts an electrical signal output by the computer 200 into physical motion. The X driver 113 is electrically connected to the computer 200. When the X driver 113 receives an electrical signal output by the computer 200, it converts the electrical signal into physical motion that moves the X-direction stage 111 in the X direction.

[0018] The orthogonal balance arm 120 is a mechanism that applies a constant load to the needle SN when the needle SN comes into contact with the test piece. The orthogonal balance arm 120 includes a Y-direction stage 121, a support 122, an arm 123, and a Y-drive unit .

[0019] The Y-direction stage 121 is a stage for adjusting the position of the orthogonal balance arm 120 in the Y direction. The Y-direction stage 121 is provided on the upper surface of the base BU of the friction tester 100 so as to be movable in the Y direction.

[0020] The support pillar 122 is a columnar member used to support the arm 123. The support pillar 122 is provided on the upper surface of the Y direction stage 121. The support pillar 122 has a rotation axis AR that supports the arm 123.

[0021] The arm 123 is a member that holds the support part 130 so that the needle SN is positioned directly above the test piece fixed to the sample table 100. The arm 123 is supported by a rotation axis AR so as to be rotatable in the θX direction.

[0022] The Y drive unit 124 is a mechanical element constituting the orthogonal balance arm 120 that converts a predetermined physical motion into another physical motion. The Y drive unit 124 is connected to a rotary handle that can be rotated by the tester. When the rotary handle is rotated, the Y drive unit 124 converts the physical motion into physical motion that moves the Y stage 121 in the Y direction.

[0023] The support part 130 is a member that supports the needle SN. The support part 130 includes a rod-shaped body 131 and a load converter 132.

[0024] The rod-shaped body 131 is a rod-shaped member having a length in the vertical direction. The rod-shaped body 131 supports the needle SN at its lower end so that the acute-angled tip of the needle SN faces downward. The rod-shaped body 131 is held by the arm 123 so that the extension direction of the axis AX of the needle SN is always vertical, even when the arm 123 rotates. In addition, a weight W can be attached to the rod-shaped body 131. The weight W is a metal block that serves as a mass standard used to apply a constant load to the needle SN.

[0025] The load converter 132 is a device that measures frictional force by converting a load signal detected by a strain gauge attached to the elongated body into mass. The load converter 132 is provided directly above the needle SN on the rod-shaped body 131, and is electrically connected to the computer 200. When the load converter 132 measures the frictional force, it outputs an electrical signal indicating the measurement value to the computer 200.

[0026] The computer 200 is a machine that automatically performs complex calculations and controls according to given procedures. For example, the computer 200 controls the state of the friction tester 100. Also, for example, the computer 200 performs complex calculations using the measured values ​​of friction force measured by the load converter 132.

[0027] The resistance evaluation system RES can scratch the film of the ophthalmic lens OL by applying a certain load to the needle SN. Also, the resistance evaluation system RES can measure the frictional force when scratching the film of the ophthalmic lens OL.

[0028] 2 shows a schematic example of the configuration of a computer 200. The computer 200 includes a control device 210, an arithmetic device 220, a storage device 230, an input device 240, and an output device 250.

[0029] The control device 210 is a device that controls the arithmetic device 220, the storage device 230, the input device 240, and the output device 250. For example, the control device 210 causes the arithmetic device 220 to generate control data that controls the X driver 113 so that the length of scratching on the film of the ophthalmic lens OL is the length set by the tester. Also, for example, the control device 210 causes the output device 250 to output an electrical signal that controls the X driver 113 in accordance with the control content indicated by the control data generated by the arithmetic device 220. Also, for example, the control device 210 controls the arithmetic device 220 to calculate the variation in frictional force measured by the load converter 132. Also, for example, the control device 210 controls the output device 250 to output information indicating the variation in frictional force.

[0030] The arithmetic unit 220 is a device that performs calculations such as arithmetic operations and logical operations. For example, the arithmetic unit 220 generates control data that controls the X-drive unit 113 so that the length of scratching on the film of the ophthalmic lens OL becomes the length set by the tester. Also, for example, the arithmetic unit 220 calculates the variation in friction force measured by the load converter 132.

[0031] The storage device 230 is a device for saving and storing data and programs. For example, the storage device 230 stores a program for calculating the control amount of the X driver 113 based on information input by the user of the friction tester 100. Also, for example, the storage device 230 stores data indicating the measurement value of the friction force measured by the load converter 132. Also, for example, the storage device 230 stores a program for calculating the variation in the friction force measured by the load converter 132.

[0032] The input device 240 is a device for providing data, information, instructions, etc. to the computer 200. For example, the input device 240 includes a device such as a touch panel through which a user of the friction tester 100 inputs information for operating the friction tester 100. Furthermore, for example, the input device 240 includes a device such as an input port through which an electrical signal output from the load converter 132 is input.

[0033] Output device 250 is a device that outputs data and signals to the outside of computer 200. For example, output device 250 includes a device such as an output port that outputs an electric signal to X drive unit 113. Furthermore, for example, output device 250 includes a device such as a touch panel that displays information indicating the variation in frictional force.

[0034] FIG. 3 schematically illustrates an example of a procedure for a test method using a resistance evaluation system RES to evaluate the scratch resistance of a film of an ophthalmic lens OL. FIGS. 4 to 7 schematically illustrate an example of a procedure for scratching the film of an ophthalmic lens OL with a needle SN. FIGS. 8 and 9 schematically illustrate an example of the relationship between the measured value of friction force and the movement distance of the needle SN. Here, with reference to FIGS. 3 to 9, the flow of a test method for evaluating the scratch resistance of a film of an ophthalmic lens OL using the resistance evaluation system RES will be described. Here, a state in which the ophthalmic lens OL is set on the sample table 110 and the Y stage 121 is moved in the Y direction to position the needle SN at a start position SP for scratching the film of the ophthalmic lens OL will be described as a starting state. For example, as shown in FIG. 4, the tester sets the start position SP to a position 25 mm away from the center of the ophthalmic lens OL in the XY plane.

[0035] First, the tester sets the initial value of the load to be applied to the needle SN when scratching the film of the ophthalmic lens OL (S101). For example, the tester sets the initial value of the load to be applied to the needle SN to "10 g" and attaches a weight W of "10 g" to the rod-shaped body 131.

[0036] Next, the tester sets the length to scratch the film of the ophthalmic lens OL (S102). In S102, the tester uses the input device 240 to input the length to scratch the film. When the length to scratch the film is input, the calculation device 220 generates control data for controlling the X drive unit 113 so that the length to scratch the film of the ophthalmic lens OL becomes the set length, and stores the control data in the storage device 230. For example, the tester sets the length to scratch the ophthalmic lens OL to "10 mm".

[0037] Next, the tester starts scratching the film of the ophthalmic lens OL and measuring the frictional force while scratching the film (S103). In S103, the tester uses the input device 240 to input information instructing the tester to start scratching the film of the ophthalmic lens OL and measuring the frictional force while scratching the film. When the information is input, the output device 250 reads control data for the X driver 113 stored in the storage device 230 and outputs an electrical signal to the X driver 113 to control the X driver 113 according to the control data. Upon receiving the electrical signal, the X driver 113 drives the X-direction stage 111 according to the control content indicated by the electrical signal. By controlling the X driver 113, the needle SN scratches the film of the ophthalmic lens OL from the start position SP toward the center of the ophthalmic lens OL while applying a constant load specified by the tester. While the needle SN scratches the film of the ophthalmic lens OL, the load converter 132 measures the frictional force and outputs an electrical signal indicating the measured value of the frictional force. When the input device 240 receives the electrical signal, it stores in the storage device 230 data that associates the measured value of the frictional force with the distance traveled by the needle SN.

[0038] If the needle SN has not moved to the length set by the tester (S104; NO), the friction tester 100 continues to scratch the film of the ophthalmic lens OL and measure the friction force while scratching the film.

[0039] As shown in FIG. 5, when the needle SN moves to the length set by the tester (S104; YES), the friction tester 100 ends scratching the film of the ophthalmic lens OL and measuring the friction force while scratching the film (SN is 105).

[0040] After scratching the film of the ophthalmic lens OL and measuring the frictional force during scratching are completed, the tester checks whether the variation in frictional force exceeds a specific value (S106). In S106, the calculation device 210 reads data stored in the storage device 230 that associates the measured values ​​of frictional force with the distance traveled by the needle SN, and calculates the variation in frictional force. For example, the calculation device 210 calculates the variation in frictional force in a section designated by the tester within the path scratched by the needle SN. Once the variation in frictional force is calculated, the output device 250 outputs information indicating the variation in frictional force. For example, to eliminate the influence of static friction, the tester designates the section after the needle SN has moved 2 mm from the start position SP as the section for which the variation in frictional force is to be calculated. For example, the tester checks whether the variation in frictional force exceeds 1.3. When the variation in friction force does not exceed "1.3", the relationship between the measured value of the friction force and the distance traveled by the needle SN is as shown in Figure 8, and the friction force does not change much after the needle SN has moved "2 mm" from the start position SP. On the other hand, when the variation in friction force exceeds "1.3", the relationship between the measured value of the friction force and the distance traveled by the needle SN is as shown in Figure 9, and the friction force changes significantly even after the needle SN has moved "2 mm" from the start position SP.

[0041] If the variation in frictional force does not exceed the specific value in S106 (S106; NO), the tester rotates the ophthalmic lens OL around the center of the ophthalmic lens OL as an axis (S107). In S106, when scratching the film of the ophthalmic lens OL again, the tester rotates the ophthalmic lens OL so that the next scratching path will be a path that does not overlap or intersect with the paths that have already been scratched. For example, the tester removes the ophthalmic lens OL fixed to the sample table 110, rotates the ophthalmic lens OL as shown in FIG. 6, and fixes it again to the sample table 110. By rotating the ophthalmic lens OL in S106, the start position SP for the next scratching becomes a position where the next scratching path will be a path that does not overlap or intersect with the paths that have already been scratched, as shown in FIG. 7.

[0042] Then, the tester resets the load to be applied to the needle SN (S108). For example, the tester sets the load to be applied to the needle SN to a value that is 10 g greater than the current load, and attaches a weight W to the rod-shaped body 131 so that the load becomes a value that is 10 g greater than the current load.

[0043] Then, the tester repeats the steps from S102 to S108 until the variation in frictional force exceeds a specific value in S106.

[0044] If the variation in frictional force exceeds a specific value in S106 (S106; YES), the tester ends the test method shown in FIG.

[0045] The tester can evaluate the resistance to scratches on the film of the ophthalmic lens OL used as a test specimen using the test method shown in Figure 3. Specifically, the tester can evaluate the resistance to scratches on the film by referring to the value of the load applied to the needle SN when the variation in friction force exceeds a specific value, the material of the needle SN, and the shape of the tip of the needle SN.

[0046] 10 to 15 show test results for measuring the variation in friction force in the examples and comparative examples. The applicant conducted tests for the examples and comparative examples using a Tribogear Type: 40 friction tester 100 sold by Shinto Scientific Co., Ltd. The applicant also conducted tests with an initial load of 10 g applied to the needle SN. The applicant also conducted tests with a start position SP located 25 mm away from the center of the ophthalmic lens OL in the XY plane. The applicant also conducted tests with an end position EP located 10 mm away from the start position SP toward the center of the ophthalmic lens OL in the XY plane. The applicant also conducted tests with the section from the position where the needle SN moved 2 mm from the start position SP to the end position EP as the target section for calculating the variation in friction force. The applicant also conducted repeated tests by increasing the load applied to the needle SN each time the needle SN scratched the film of the ophthalmic lens OL until a scratch that was easily visible to the naked eye was created.

[0047] In Example 1, the applicant used an ophthalmic lens OL with a convex curvature of 1.25K, a hard coat thickness of 3 μm, five anti-reflection layers, and an oil-repellent top coat as a test specimen. The applicant also used a needle SN made of sapphire with a tip shape of R0.05 mm, 60 degrees. In Example 1, the applicant confirmed that when a load of 80 g was applied to the needle SN, scratches were created that were easily visible to the naked eye. The variation in frictional force at this time was 2.48.

[0048] In Example 2, the applicant used an ophthalmic lens OL with a convex curvature of 2.00K, a hard coat thickness of 3 μm, five anti-reflection layers, and an oil-repellent top coat as a test specimen. The applicant also used a needle SN made of sapphire with a tip shape of 0.05 mm and 60 degrees. In Example 2, the applicant confirmed that when a load of 100 g was applied to the needle SN, scratches were created that were easily visible to the naked eye. The variation in frictional force at this time was 1.92.

[0049] In Example 3, the applicant used an ophthalmic lens OL with a convex curvature of 3.00K, a hard coat thickness of 3 μm, five anti-reflection layers, and an oil-repellent top coat as a test specimen. The applicant also used a needle SN made of sapphire with a tip shape of 0.05 mm and a 60-degree radius. In Example 3, the applicant confirmed that a scratch that was easily visible when a load of 50 g was applied to the needle SN was created. The variation in frictional force at this time was 1.56.

[0050] In Example 4, the applicant used an ophthalmic lens OL with a convex curvature of 4.50K, a hard coat thickness of 3 μm, five anti-reflection layers, and an oil-repellent top coat as a test specimen. The applicant also used a needle SN made of sapphire with a tip shape of 0.05 mm and 60 degrees. In Example 4, the applicant confirmed that when a load of 70 g was applied to the needle SN, scratches were easily visible. The variation in frictional force at this time was 1.84.

[0051] In Example 5, the applicant used an ophthalmic lens OL with a convex curvature of 1.25K, a hard coat thickness of 3 μm, five anti-reflection layers, and an oil-repellent top coat as a test specimen. The applicant also used a needle SN made of sapphire with a tip shape of 0.05 mm and a 90-degree radius. In Example 5, the applicant confirmed that a scratch that was easily visible when a load of 70 g was applied to the needle SN was created. The variation in frictional force at this time was 1.72.

[0052] In Example 6, the applicant used an ophthalmic lens OL with a convex curvature of 1.25K, a hard coat thickness of 3 μm, five anti-reflection layers, and an oil-repellent top coat as a test specimen. The applicant also used a needle SN made of sapphire with a tip shape of 0.01 mm and a 60-degree radius. In Example 6, the applicant confirmed that a scratch that was easily visible when a load of 10 g was applied to the needle SN was created. The variation in frictional force at this time was 3.36.

[0053] In Example 7, the applicant used an ophthalmic lens OL with a convex curvature of 1.25K, a hard coat thickness of 3 μm, five anti-reflection layers, and a water-repellent top coat as a test specimen. The applicant also used a needle SN made of sapphire with a tip shape of 0.05 mm and a 60-degree radius. In Example 7, the applicant confirmed that a scratch that was easily visible when a load of 40 g was applied to the needle SN was created. The variation in frictional force at this time was 4.98.

[0054] In Example 8, the applicant used an ophthalmic lens OL with a convex curvature of 2.00K, a hard coat thickness of 3 μm, five anti-reflection layers, and a water-repellent top coat as the test specimen. The applicant also used a needle SN made of sapphire with a tip shape of 0.05 mm and a 60-degree radius. In Example 8, the applicant confirmed that a scratch that was easily visible when a load of 60 g was applied to the needle SN was created. The variation in frictional force at this time was 2.56.

[0055] In Example 9, the applicant used an ophthalmic lens OL with a convex curvature of 3.00K, a hard coat thickness of 3 μm, five anti-reflection layers, and a water-repellent top coat as the test specimen. The applicant also used a needle SN made of sapphire with a tip shape of 0.05 mm and a 60-degree radius. In Example 9, the applicant confirmed that a scratch that was easily visible when a load of 50 g was applied to the needle SN was created. The variation in frictional force at this time was 1.82.

[0056] In Example 10, the applicant used an ophthalmic lens OL with a convex curvature of 4.50K, a hard coat thickness of 3 μm, five anti-reflection layers, and a water-repellent top coat as a test specimen. In Example 10, the applicant used a needle SN made of sapphire with a tip shape of R0.05 mm, 60 degrees. In Example 10, the applicant confirmed that when a load of 50 g was applied to the needle SN, scratches were easily visible. The variation in frictional force at this time was 2.23.

[0057] In Example 11, the applicant used an ophthalmic lens OL with a convex curvature of 1.25K, a hard coat thickness of 3 μm, five anti-reflection layers, and a water-repellent top coat as a test specimen. In Example 11, the applicant used a needle SN made of sapphire with a tip shape of 0.05 mm and a 90-degree radius. In Example 11, the applicant confirmed that a scratch that was easily visible when a load of 40 g was applied to the needle SN was created. The variation in frictional force at this time was 2.13.

[0058] In Example 12, the applicant used an ophthalmic lens OL with a convex curvature of 1.25K, a hard coat thickness of 3 μm, five anti-reflection layers, and a water-repellent top coat as a test specimen. In Example 12, the applicant used a needle SN made of sapphire with a tip shape of R 0.01 mm, 60 degrees. In Example 12, the applicant confirmed that when a load of 10 g was applied to the needle SN, scratches were easily visible. The variation in frictional force at this time was 2.63.

[0059] In Example 13, the applicant used an ophthalmic lens OL with a convex curvature of 0.50 K, a hard coat thickness of 10 μm, eight anti-reflection layers, and an oil-repellent top coat as a test specimen. In Example 13, the applicant used a needle SN made of sapphire with a tip shape of R0.05 mm, 60 degrees. In Example 13, the applicant confirmed that when a load of 160 g was applied to the needle SN, scratches were easily visible. The variation in frictional force at this time was 11.12.

[0060] In Example 14, the applicant used an ophthalmic lens OL with a convex curvature of 0.50 K, a hard coat thickness of 3 μm, eight anti-reflection layers, and an oil-repellent top coat as a test specimen. In Example 14, the applicant used a needle SN made of sapphire with a tip shape of R0.05 mm, 60 degrees. In Example 14, the applicant confirmed that when a load of 80 g was applied to the needle SN, scratches were created that were easily visible to the naked eye. The variation in frictional force at this time was 9.37.

[0061] In Example 15, the applicant used an ophthalmic lens OL with a convex curvature of 1.25K, a hard coat thickness of 3 μm, five anti-reflection layers, and an oil-repellent top coat as a test specimen. In Example 15, the applicant used a needle SN made of sapphire with a tip shape of R0.05 mm, 60 degrees. In Example 15, the applicant confirmed that when a load of 100 g was applied to the needle SN, scratches were created that were easily visible to the naked eye. The variation in frictional force at this time was 2.37.

[0062] In Example 16, the applicant used an ophthalmic lens OL with a convex curvature of 0.50 K, a hard coat thickness of 3 μm, five anti-reflection layers, and an oil-repellent top coat as a test specimen. In Example 16, the applicant used a needle SN made of sapphire with a tip shape of R0.05 mm, 60 degrees. In Example 16, the applicant confirmed that when a load of 90 g was applied to the needle SN, scratches were easily visible. The variation in frictional force at this time was 1.40.

[0063] In Comparative Example 1, the applicant used an ophthalmic lens OL with a convex curvature of 1.25K, a hard coat thickness of 3 μm, eight anti-reflection layers, and an oil-repellent top coat as the test specimen. The applicant also used a needle SN made of diamond with a tip shape of 0.05 mm and a 90-degree radius. In Comparative Example 1, the applicant confirmed that when a load of 50 g was applied to the needle SN, scratches were created that were easily visible to the naked eye. The variation in frictional force at this time was 0.78.

[0064] In Comparative Example 2, the applicant used an ophthalmic lens OL with a convex curvature of 1.25K, a hard coat thickness of 3 μm, five anti-reflection layers, and a water-repellent top coat as the test specimen. In Comparative Example 2, the applicant also used a needle SN made of diamond with a tip shape of 0.05 mm and a 90-degree radius. In Comparative Example 2, the applicant confirmed that when a load of 40 g was applied to the needle SN, scratches were created that were easily visible to the naked eye. The variation in frictional force at this time was 0.96.

[0065] In Examples 1 to 4, 14, and 15, the test specimens were ophthalmic lenses OL with different convex curvatures, the same hard coat film thickness, and the same type of top coat. Furthermore, in Examples 1 to 4, 14, and 15, needles SN with the same material and tip shape were used. According to Examples 1 to 4, 14, and 15, even if the convex curvatures of the ophthalmic lenses OL were different, scratches that were easily visible to the naked eye were formed when the variation in friction force exceeded "1.3."

[0066] In Examples 1, 5, and 6, the test specimens were ophthalmic lenses OL with the same convex curvature, hard coat film thickness, and hard coat type. Furthermore, Examples 1, 5, and 6 used needles SN with different tip shapes but made of the same material. According to Examples 1, 5, and 6, even if the tip shapes of the needles SN were different, scratches that were easily visible to the naked eye were created when the variation in friction force exceeded "1.3."

[0067] In Examples 1 and 7, the test specimens were ophthalmic lenses OL with different types of top coats but the same convex curvature and hard coat film thickness. Furthermore, in Examples 1 and 7, needles SN with the same material and tip shape were used. According to Examples 1 and 7, even if the types of top coats were different, scratches that were easily visible to the naked eye were created when the variation in friction force exceeded "1.3."

[0068] In Examples 7 to 10, the test specimens were ophthalmic lenses OL with different convex curvatures, but with the same hard coat film thickness and top coat type. Furthermore, in Examples 7 to 10, needles SN with the same material and tip shape were used. It can be seen from Examples 7 to 10 that even when the convex curvatures were different, scratches that were easily visible to the naked eye were created when the variation in friction force exceeded "1.3."

[0069] In Examples 7, 11, and 12, the test specimens were ophthalmic lenses OL with the same convex curvature, hard coat film thickness, and top coat type. Furthermore, Examples 7, 11, and 12 used needles SN with different tip shapes but made of the same material. According to Examples 7, 11, and 12, even if the tip shapes of the needles SN were different, scratches that were easily visible to the naked eye were created when the variation in friction force exceeded "1.3."

[0070] In Examples 13 and 14, the test specimens were ophthalmic lenses OL with different hard coat film thicknesses, the same convex curvature, and the same type of top coat. Furthermore, in Examples 13 and 14, needles SN with the same material and tip shape were used. According to Examples 13 and 14, even when the hard coat film thicknesses were different, scratches that were easily visible to the naked eye were created when the variation in friction force exceeded "1.3."

[0071] In Example 5 and Comparative Example 1, the test specimens were ophthalmic lenses OL with the same convex curvature, hard coat film thickness, and top coat type. Furthermore, Example 5 and Comparative Example 1 used needles SN made of different materials but with the same tip shape. According to Example 5 and Comparative Example 1, it can be seen that when a "sapphire" needle SN is used, scratches that are easily visible to the naked eye are created when the frictional force variation exceeds "1.3". Furthermore, according to Example 5 and Comparative Example 1, it can be seen that when a "diamond" needle SN is used, scratches that are easily visible to the naked eye are created even when the frictional force variation does not exceed "1.3".

[0072] In Example 11 and Comparative Example 2, the test specimens were ophthalmic lenses OL with the same convex curvature, hard coat film thickness, and top coat type. Furthermore, Example 11 and Comparative Example 2 used needles SN made of different materials but with the same tip shape. According to Example 11 and Comparative Example 2, it can be seen that when a "sapphire" needle SN is used, scratches that are easily visible to the naked eye are created when the frictional force variation exceeds "1.3". Furthermore, according to Example 11 and Comparative Example 2, it can be seen that when a "diamond" needle SN is used, scratches that are easily visible to the naked eye are created even when the frictional force variation does not exceed "1.3".

[0073] According to Examples 4, 15, and 16, no scratches are produced even when the variation in frictional force exceeds "1.2," but scratches that are easily visible to the naked eye are produced when the variation in frictional force exceeds "1.3."

[0074] In Example 13, the load applied to the needle SN when the variation in frictional force exceeded 1.3 was larger than the loads in the other Examples. From this, the applicant was able to confirm that the ophthalmic lens OL used as the test specimen in Example 13 had excellent scratch resistance.

[0075] Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the claims that such modifications and improvements can also be included within the technical scope of the present invention.

[0076] In the above embodiment, an example has been described in which the ophthalmic lens OL that is the target of the test method for evaluating the scratch resistance of the film of the ophthalmic lens OL is a lens used for at least one of eye measurement, correction, and protection. However, the ophthalmic lens OL that is the target of the test method may be another lens. For example, the ophthalmic lens OL that is the target of the test method may be a lens used to change the appearance.

[0077] It should be noted that the execution order of each process, such as operations, procedures, steps, and stages, in the devices, systems, programs, and methods shown in the claims, specifications, and drawings, is not specifically stated as "before," "prior to," etc., and that the processes can be performed in any order unless the output of a previous process is used in a subsequent process. Even if the operational flow in the claims, specifications, and drawings is described using "first," "next," etc. for convenience, this does not mean that the processes must be performed in this order. [Explanation of symbols]

[0078] 100 friction tester, 110 sample table, 111 X-direction stage, 112 jig, 113 X-drive unit, 120 orthogonal balance arm, 121 Y-direction stage, 122 support, 123 arm, 124 Y-drive unit, 130 support unit, 131 rod-shaped body, 132 load converter, 200 computer, 210 control device, 220 calculation device, 230 storage device, 240 input device, 250 output device, AR rotation axis, AX axis, BU base, EP end position, OL ophthalmic lens, RES resistance evaluation system, SN needle, SP start position, W weight

Claims

1. 1. A test method for evaluating the scratch resistance of a film on an ophthalmic lens, comprising: applying a constant load to the needle to scratch the film; measuring the frictional force while scratching the film; If the variation in frictional force in one scratch is smaller than a specific value, the load applied to the needle is increased, the film is scratched again, and the frictional force is measured; A test method in which the film is scratched and the frictional force measured at that time is repeatedly measured until the variation in frictional force in one scratch exceeds a specific value.

2. If the variation in frictional force in one scratch is less than 1.3, the load applied to the needle is increased, the film is scratched again, and the frictional force is measured; 2. The test method according to claim 1, wherein scratching the film and measuring the frictional force at that time are repeated until the variation in frictional force in one scratch exceeds 1.

3.

3. 3. The test method according to claim 1, wherein a sapphire needle is used to scratch the film.

4. The testing method according to any one of claims 1 to 3, wherein a needle having a tip diameter of 0.1 mm or less is used to scratch the film.

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