Scratching device and scratch formation method

Abstract

To improve the reproducibility of a scratch shape occurring in daily life. A scratching device (110) for forming a scratch on a spectacle lens (Ln) in order to evaluate the scratch resistance of the spectacle lens (Ln), the scratching device (110) comprising: a scratching member (220) having a rough surface; a holding unit (210) for holding the spectacle lens (Ln); and a control device (260) for moving one or both of the holding unit (210) and the scratching member (220) in a state in which the rough surface is in contact with the spectacle lens (Ln) held by the holding unit (210).

Description

Scratch device and scratch formation method

[0001] The present disclosure relates to a scratch device and a scratch formation method.

[0002] A plurality of layers of coatings are formed on the base material of the spectacle lens. These coatings are important for protecting the spectacle lens from scratches. Evaluating the scratch resistance of the coating is important for determining how resistant the coating is to scratches that occur in daily life.

[0003] Currently known methods for evaluating scratch resistance include the method of using steel wool described in Patent Document 1 and the method of scraping the coating with a diamond needle described in Patent Document 2. The shape of the scratches obtained with steel wool or a diamond needle may have low reproducibility of the scratch shape that occurs in daily life.

[0004] Japanese Patent Application Laid-Open No. 2003-295131, Japanese Patent Application Laid-Open No. 2013-205776

[0005] According to a first aspect of the present disclosure, there is provided a scratch device for forming a scratch on a spectacle lens in order to evaluate the scratch resistance of the spectacle lens, the scratch device including a scratch member having a rough surface, a holding portion for holding the spectacle lens, and a control device for moving both or either of the holding portion and the scratch member in a state where the rough surface is in contact with the spectacle lens held by the holding portion.

[0006] According to a second aspect of the present disclosure, there is provided a scratch formation method for forming a scratch for evaluating the scratch resistance on the spectacle lens using a scratch member, the method including bringing the rough surface formed on the scratch member into contact with the spectacle lens, and forming the scratch on the spectacle lens by moving both or either of the spectacle lens and the scratch member in a state where the rough surface is in contact with the spectacle lens.

[0007] This is a schematic diagram of the scratch resistance evaluation test system according to this embodiment. This is a schematic diagram of the scratch-resistant device according to this embodiment. This is a view of the lens holder according to this embodiment from the Y direction. This is a view of the lens holder according to this embodiment from the Z direction. This is a schematic diagram of the scratch-resistant member 220 according to this embodiment viewed from above. This is a diagram illustrating the flow of the scratch resistance evaluation method according to this embodiment. This shows the state in which a rough surface is in contact with the upper surface of an eyeglass lens according to this embodiment. This is a diagram showing the measurement results of scratch depth data for scratches that occur on an eyeglass lens in daily life according to this embodiment. This is a diagram showing the measurement results of scratch depth data for scratches made by the first conventional method. This is a diagram showing the measurement results of scratch depth data for scratches made by the second conventional method. This is a diagram showing the measurement results of scratch depth data for scratches made with the scratch-resistant device according to this embodiment. This is a diagram showing another example of the measurement results of scratch depth data for scratches made with the scratch-resistant device according to this embodiment.

[0008] The present invention will be described below through embodiments, but these embodiments are not intended to limit the invention as defined in the claims. Furthermore, not all combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0009] In the following explanation, directions in the diagrams will be described using the XYZ coordinate system. In this XYZ coordinate system, the vertical direction is the Z direction, one direction on the horizontal plane is the X direction, and the direction of the horizontal plane intersecting the X direction is the Y direction. Furthermore, the X, Y, and Z directions will be referred to as the + side (indicated by the arrow) and the opposite side as the - side (indicated by the arrow).

[0010] Eyeglass lenses have multiple layers of coating Co formed on a substrate Lb. The substrate of the eyeglass lens is, for example, a glass substrate or a plastic substrate. The coating Co is important for protecting the lens from scratches. When developing the coating Co, it is necessary to evaluate the scratch resistance of the coating Co to confirm how durable it is in everyday life. In this embodiment, scratch resistance refers to how difficult it is for the eyeglass lens to be scratched when the surface of the eyeglass lens is rubbed or scratched.

[0011] For example, one method for evaluating scratch resistance involves using steel wool or a diamond needle as an abrasive material to scratch the spectacle lens by pressing and moving it, and then evaluating the condition of the scratches (hereinafter referred to as the "first conventional method"). Another method involves placing small stones inside a box containing spectacle lenses, shaking the box to scratch the lenses, and then evaluating the condition of the scratches (hereinafter referred to as the "second conventional method").

[0012] Here, the shape of scratches that actually occur on eyeglass lenses in everyday life may differ from the shape of scratches obtained by the first and second conventional methods. Therefore, it is unclear whether the evaluation of scratches obtained using the first and second conventional methods correlates with the strength of everyday scratch resistance.

[0013] Furthermore, since each coating layer formed on the substrate of the eyeglass lens may have different material properties, the mechanism by which scratches are formed (hereinafter referred to as the "scratch mechanism") is complex. Therefore, even if scratches are made using the first or second conventional method, it may not be possible to reproduce the scratch shape that occurs in daily life. When evaluating scratch resistance using scratches obtained by the first or second conventional method, a large amount of data may be required to obtain a correlation between those scratches and scratches that occur in daily life.

[0014] Unlike the first and second conventional methods, the scratching device of this embodiment uses a member with a rough surface as the scratching member, and by pressing the rough surface against an eyeglass lens and moving it, it is possible to reproduce the shape of scratches that actually occur in daily life. Therefore, the correlation between scratches formed by the scratching device of this embodiment and scratches that occur in daily life becomes clear, and the accumulation of a large amount of data to obtain the correlation becomes unnecessary.

[0015] The scratch resistance evaluation test system 100, including the scratch resistance device according to this embodiment, will be described below. Figure 1 is a schematic configuration diagram of the scratch resistance evaluation test system 100 according to this embodiment. As shown in Figure 1, the scratch resistance evaluation test system 100 includes, for example, a scratch resistance device 110 and a measuring device 120.

[0016] The scratching device 110 is a device that forms scratches on an eyeglass lens Ln in order to evaluate the scratch resistance of the eyeglass lens Ln. Figure 2 is a schematic diagram of the scratching device 110 according to this embodiment.

[0017] As shown in Figure 2, the scratching device 110 comprises a lens holder 210, a scratching member 220, an arm 230, a jig 240, a weight 250, and a control device 260.

[0018] The lens holder 210 holds the spectacle lens Ln. Figure 3 is a view of the lens holder 210 from the Y direction. Figure 4 is a view of the lens holder 210 from the Z direction. As shown in Figures 3 and 4, the lens holder 210 comprises a base 300, a guide shaft 310, two sliding members 320a and 320b, a handle 330, a contact portion 340, and a locking lever 350. The lens holder 210 is an example of a holding part.

[0019] The base 300 is supported on the erected support section S. A guide shaft 310 is installed on the base 300.

[0020] The guide shaft 310 is capable of moving the slide members 320a and 320b in the ±X directions. The guide shaft 310 links the movement of slide member 320a with the movement of slide member 320b. The guide shaft 310 is a member that extends in the X direction and has, for example, a rod shape. The guide shaft 310 is rotatably supported at its central portion and both ends by bearings provided on the base 300.

[0021] A threaded portion 311 is formed on the outer circumferential surface of the guide shaft 310. The threaded portion 311 is formed on both sides of the guide shaft 310, with the central part of the guide shaft 310 in between. The threaded portion 311 formed on one side of the guide shaft 310 is sometimes referred to as "threaded portion 311a," and the threaded portion 311 formed on the other side is sometimes referred to as "threaded portion 311b." Threaded portions 311a and 311b are threaded portions with opposite directions. For example, if threaded portion 311a is a right-hand thread, then threaded portion 311b is a left-hand thread with the opposite direction.

[0022] A handle 330 is provided at one end of the guide shaft 310. The handle 330 is used to rotate the guide shaft 310. The user can rotate the guide shaft 310 by turning the handle 330.

[0023] The sliding members 320a and 320b are positioned on the upper surface of the base 300. The sliding members 320a and 320b are members that extend in the Y direction. On the upper surface of the base 300, the sliding members 320a and 320b are positioned parallel to each other in the Y direction.

[0024] The slide member 320a is screwed onto the threaded portion 311a. The slide member 320b is screwed onto the threaded portion 311b. The slide member 320a slides in the +X direction as the guide shaft 310 rotates in the first direction. The slide member 320b slides in the -X direction as the guide shaft 310 rotates in the first direction. In other words, the slide members 320a and 320b slide towards each other in a coordinated manner as the guide shaft 310 rotates in the first direction.

[0025] The sliding member 320a slides in the -X direction as the guide shaft 310 rotates in a second direction opposite to the first direction. The sliding member 320b slides in the +X direction as the guide shaft 310 rotates in the second direction. In other words, the sliding members 320a and 320b slide in a direction away from each other while being linked together as the guide shaft 310 rotates in the second direction.

[0026] Multiple contact portions 340 are provided on each of the slide member 320a and slide member 320b. In the example shown in Figures 3 and 4, a pair of contact portions 340 are provided on each of the slide member 320a and slide member 320b. Each contact portion 340 supports the spectacle lens Ln by contacting the outer circumferential surface of the spectacle lens Ln. The pair of contact portions 340 are each provided on the slide members 320a and 320b via a support shaft 321. Each contact portion 340 is, for example, a cylindrical elastic member. The pair of contact portions 340 are each provided side by side in the Y direction.

[0027] The lock lever 350 is provided on the base 300. The lock lever 350 can lock and unlock the rotation of the guide shaft 310. The lock lever 350 is used by the user to lock or unlock the rotation of the guide shaft 310. For example, the lock lever 350 locks the rotation of the guide shaft 310 by rotating it in one direction with the axis of rotation parallel to the Z-axis. When the rotation of the guide shaft 310 is locked, the sliding movement of the slide members 320a and 320b is also locked. On the other hand, the lock lever 350 unlocks the rotation of the guide shaft 310 by rotating it in the other direction. When the rotation of the guide shaft 310 is unlocked, the sliding movement of the slide members 320a and 320b becomes possible.

[0028] The arm 230 is a member that extends horizontally. In the example shown in Figure 2, the arm 230 is a member that extends in the Y direction. The tip of the arm 230 is positioned above the lens holder 210.

[0029] The jig 240 is a component attached to the tip of the arm 230 and extending downward. The jig 240 extends from the tip of the arm 230 in the -Z direction. A scratching member 220 is attached to the tip of the jig 240.

[0030] Figure 5 is a schematic diagram of the scratch-resistant member 220 according to this embodiment, viewed from above. As shown in Figure 5, the scratch-resistant member 220 is a member having a rough surface 221. The rough surface 221 is, for example, a non-perfect plane. In the example shown in Figure 5, the scratch-resistant member 220 is, for example, a plate member (rough surface plate) whose surface is a rough surface 221. For example, the rough surface 221 has a plurality of protrusions 222 having a streak-like shape along a specific direction on its surface. The specific direction is, for example, one direction in a plane parallel to the rough surface 221. As shown in Figure 2, when the scratch-resistant member 220 is attached to the jig 240, it is attached to the jig 240 so that the specific direction is the Y direction. Note that the shape of the protrusions 222 is not limited to a shape that extends linearly along the specific direction, but may also include some curvature or deformation while following the specific direction. Also, each of the plurality of protrusions 222 may be arranged regularly or irregularly. The shape of the protrusions 222 on the rough surface shown in Figure 5 is just one example and is not limited to a streak-like shape along a specific direction. For example, the protrusions 222 may have a granular or spotted shape.

[0031] For example, a rough surface 221 is formed on the first surface of the rough surface plate. On the rough surface plate, the second surface opposite to the first surface is attached to the tip of the jig 240. This supports the scratching member 220 so that the rough surface 221 is parallel to the horizontal plane. For example, the rough surface 221 is positioned parallel to the surface (geometric center) of the spectacle lens Ln held in the lens holder 210. In other words, with respect to the geometric center of the spectacle lens Ln held in the lens holder 210, its surface and the rough surface 221 are parallel to the horizontal plane. This makes it possible to apply uniform friction and scratches to the center of the lens during testing, and to perform accurate and reproducible scratch resistance evaluation. The scratching member 220 forms scratches on the spectacle lens Ln held in the lens holder 210 by scratching it with the rough surface 221, in order to evaluate scratch resistance.

[0032] The surface roughness of the rough surface 221 of the scratch-resistant member 220 may satisfy, for example, one or more of the following (1) to (3). Satisfying one or more of (1) to (3) includes satisfying any one of (1) to (3), satisfying any two of (1) to (3), and satisfying all of (1) to (3).

[0033] (1) The arithmetic mean roughness Ra is within the range of 1500 nm or more and 4100 nm or less. (2) The maximum height Rz is within the range of 9000 nm or more and 23500 nm or less. (3) The surface irregularity length Sm is within the range of 100 nm or more and 150 nm or less.

[0034] Arithmetic mean roughness Ra is one of the indicators of surface roughness, and it indicates the average deviation of surface irregularities over a specific reference length. For example, a smaller value of arithmetic mean roughness Ra indicates a smoother surface, while a larger value indicates a rougher surface. Maximum height Rz is one of the indicators of surface roughness, and it indicates the difference in height between the highest convex and lowest concave parts of the surface within the measurement range. Irregularity length Sm is one of the evaluation indicators of surface roughness, and it is a value that indicates the periodicity of surface irregularities. Specifically, irregularity length Sm represents the average distance between adjacent convex and concave parts within a reference length. The value of irregularity length Sm indicates how often the surface roughness pattern is repeated, that is, how often surface irregularities appear.

[0035] Returning to Figure 2, the control device 260 comprises a drive unit 261 and a control unit 262. The drive unit 261 includes a mechanism for moving the arm 230 in the horizontal direction. The drive unit 261 may include, for example, a drive source for moving the arm 230 in the horizontal direction and an actuator for transmitting the driving force of the drive source to the arm 230. For example, the drive unit 261 may include a mechanism for moving the arm 230 in the horizontal direction using an electric motor, or a mechanism for moving the arm 230 in the horizontal direction using pneumatics. In the example shown in Figure 2, the drive unit 261 moves the arm 230 in the ±Y direction. However, it is not limited to this, and the drive unit 261 may move in any specific direction on the horizontal plane, for example, in the ±X direction.

[0036] The control unit 262 controls the horizontal movement of the arm 230 by controlling the drive unit 261. The control unit 262 activates the drive unit 261 when the rough surface 221 of the scratching member 220 is in contact with the spectacle lens Ln, causing the arm 230 to move in the ±Y direction. As a result, the scratching member 220 moves in the ±Y direction, and scratches are formed on the surface of the spectacle lens Ln by scratching it with the rough surface 221 of the scratching member 220.

[0037] The control unit 262 can control the movement distance, movement speed, and number of movements of the arm 230 in the ±Y direction by controlling the drive unit 261. The movement distance of the arm 230 in the ±Y direction is the movement distance of the scratching member 220 in the ±Y direction. For example, the control unit 262 performs an operation to move the scratching member 220 by K cm in both the +Y direction and the -Y direction, N times. For example, the control unit 262 performs a reciprocating operation N times, moving the scratching member 220 by K cm in the +Y direction, and then moving the scratching member 220 by K cm in the -Y direction. K and N can be set to any appropriate value.

[0038] The weight 250 is placed on the tip of the arm 230. The load of the weight 250 presses the rough surface 221 of the scratching member 220 against the spectacle lens Ln. When the spectacle lens Ln is actually used, for example, the lens surface may be wiped with a cloth or subjected to external pressure while wearing the glasses. By applying a load using the weight 250, it is possible to reproduce the pressure on the spectacle lens during the test and simulate a more realistic usage environment.

[0039] Furthermore, by applying a constant load to the spectacle lens Ln using weight 250, variations in test results can be suppressed, improving the reproducibility of scratch resistance evaluation. The load of weight 250 can be adjusted to any value. For example, the load of weight 250 may be adjusted according to the test conditions. For instance, by changing the conditions from light load tests to heavy load tests, the scratch resistance of the spectacle lens Ln can be evaluated under various conditions.

[0040] Returning to Figure 1, the measuring device 120 measures the depth of the scratches on the spectacle lens formed by the scratching device 110. For example, the measuring device 120 may be a so-called interferometric measuring device that shines light on the surface of the spectacle lens and measures the depth of the spectacle lens Ln using interference fringes generated by the difference in phase of reflected light between the scratched and unscratched areas.

[0041] Next, a scratch resistance evaluation method using the scratch formation method by the scratch-forming device 110 according to this embodiment will be explained with reference to Figure 6. Figure 6 is a diagram illustrating the flow of the scratch resistance evaluation method according to this embodiment.

[0042] First, the operator unlocks the rotation of the guide shaft 310 by turning the lock lever 350 to the other side (step S101). Once the rotation of the guide shaft 310 is unlocked, the guide shaft 310 becomes rotatable. The operator then places the spectacle lens Ln to be evaluated between the slide member 320a and the slide member 320b (step S102).

[0043] The operator rotates the handle 330 in the first direction to move the slide members 320a and 320b, causing the contact portion 340 to support the spectacle lens Ln (step S103). For example, in step S103, when the handle 330 is rotated in the first direction, the guide shaft 310 rotates in the first direction, causing the slide members 320a and 320b to slide toward each other in a coordinated manner. As the slide members 320a and 320b contact the outer surface of the spectacle lens Ln with the contact portion 340, the spectacle lens Ln is supported by the multiple contact portions 340.

[0044] As shown in Figure 5, the operator inserts the spectacle lens Ln inside the contact portion 340 and rotates the lock lever 350 to lock the rotation of the guide shaft 310 so that the slide members 320a and 320b do not move (step S104). This fixes the spectacle lens Ln in place with the contact portion 340. When the spectacle lens Ln is fixed in place with the contact portion 340, in a plan view, the geometric center of the upper surface of the spectacle lens Ln may coincide with or approximately coincide with the center of the rough surface 221 of the scratching member 220.

[0045] Next, the operator places a weight 250 with a preset load on the tip of the arm 230, and brings the rough surface 221 of the scratch member 220 into contact with and press against the upper surface of the spectacle lens Ln (step S105). FIG. 7 shows a state where the rough surface 221 is in contact with the upper surface of the spectacle lens Ln. As shown in FIG. 7, the rough surface 221 is installed in a state parallel to the horizontal plane while being in contact with the geometric center on the upper surface of the spectacle lens Ln.

[0046] The operator operates an operation unit (not shown) provided in the control unit 262 to activate the scratch device 110. When starting to operate, the scratch device 110 moves the scratch member 220 by reciprocating the arm 230 in the horizontal direction while the rough surface 221 is in contact with the spectacle lens Ln shown in FIG. 7 (step S106). Thereby, a scratch for evaluating the scratch resistance is formed on the spectacle lens Ln. The settings of the reciprocating motion such as the distance, speed, and number of reciprocations to be reciprocated may be preset or input by the operator immediately before step S106.

[0047] The measuring device 120 measures the depth of the scratch formed on the spectacle lens Ln by the process of step S107 (step S107). The measuring device 120 outputs the measurement result (hereinafter referred to as "scratch depth data") to the display screen of the measuring device 120 (step S108). The scratch depth data includes, for example, data on the width of the scratch and data on the height in the width direction of the scratch.

[0048] Hereinafter, an example of the effects of the present embodiment will be described. FIG. 8 is a diagram showing the measurement result of the scratch depth data of scratches generated on spectacle lenses in daily life. FIG. 9 is a diagram showing the measurement result of the scratch depth data of scratches made on spectacle lenses by the first conventional method (using a diamond needle). FIG. 10 is a diagram showing the measurement result of the scratch depth data of scratches made by the second conventional method. FIG. 11 is a diagram showing the measurement result of the scratch depth data of scratches made on spectacle lenses by the scratch device 110 according to the present embodiment.

[0049] In Figures 8 to 11, the vertical axis represents height in nanometers (nm). On the vertical axis, with 0 (zero) as the reference point, a positive value indicates that the surface of the object is higher than the reference point (protruding), while a negative value indicates that it is lower than the reference point (recessed). The horizontal axis represents the position of scratches on the spectacle lens in the width direction, in micrometers (μm).

[0050] As shown in Figure 8, scratches S1 that occur on eyeglass lenses in daily life have an overall uneven shape with a certain width. For example, the width H1 of scratches S1 that occur on eyeglass lenses in daily life is the range from the point in time when the change in the object's surface from the reference point begins to the point in time when the object's surface returns to the reference point. The width H1 shown in Figure 8 is approximately 105 μm. The height D1 of scratches S1 that occur on eyeglass lenses in daily life is approximately 5000 nm at its maximum.

[0051] Thus, scratches S1 that occur on eyeglass lenses in daily life have a maximum height D1 of approximately 5000 nm and consist of a relatively large single indentation C1. Furthermore, the indentation C1 has fine irregularities within it with a width of several micrometers. In other words, scratches S1 that occur on eyeglass lenses in daily life are not simply a single smooth indentation, but are characterized by having fine irregularities within a relatively large indentation C1 of a specific width.

[0052] Next, we will describe the scratch S2 made on the spectacle lens using the first conventional method (using a diamond needle). The scratch S2 shown in Figure 9 has a portion where the surface of the spectacle lens rises sharply and reaches a height of approximately 1500 nm. This portion indicates the presence of a large protrusion on the surface. Subsequently, it descends sharply, reaching a depth of approximately 1200 nm, indicating the presence of a relatively large depression C2. Furthermore, after the depression C2, it rises again, forming another large peak around 1200 nm, and then descends slowly, returning to the vicinity of the original surface (reference).

[0053] The shape of the scratch S2 is such that the width H2 of the scratch is approximately 100 μm, and it has a protrusion with a height of approximately 1500 nm and a depression C2 with a depth of approximately 1200 nm. Therefore, the scratch S2 has a complex shape in which both a large protrusion and a large depression are formed on the surface. Furthermore, the protrusion has a sharp shape with a steep edge.

[0054] Here, comparing the scratch S2 made on the eyeglass lens by the first conventional method with the scratch S1 that occurs in daily life, the width of the scratches is similar, but the shape of the scratches is significantly different. For example, scratch S2 differs from scratch S1 in that it has a complex shape in which protrusions and indentations appear alternately. Also, the indentation C2 formed in scratch S2 is a smooth indentation and does not have multiple fine bumps and ridges. Furthermore, scratch S2 differs in that the maximum height D2 of the scratch is 2700 nm, while the maximum depth of scratch S1 is approximately 5000 nm.

[0055] Next, we will describe the scratch S3 that was inflicted on the spectacle lens using the second conventional method. As shown in Figure 10, the scratch S3 has many relatively flat areas along the reference plane, but there are also several sharp protrusions and depressions. These sharp protrusions are relatively small, about 250 nm in size. The depth of the depressions is about 200 nm to 400 nm. Thus, the scratch S3 consists only of several small bumps and dips. In other words, the scratch S3 has a shape in which several small bumps and dips are dispersed on the surface.

[0056] Here, comparing the scratch S3 made on the eyeglass lens by the second conventional method with the scratch S1 that occurs in daily life, there are significant differences in the shape of the scratches. For example, the width of scratch S3 is less than 10 μm, while the width of scratch S1 is about 105 μm. Also, regarding the depth of the scratches, the depth of scratch S3 is about 200 nm to 400 nm, which is shallower than scratch S1. Furthermore, scratch S3 does not have a wide recess, but rather has a shape in which multiple small bumps and ridges are dispersed on the surface, which is different from the shape of scratch S1.

[0057] Next, we will describe the scratches S4 made on the eyeglass lens using the scratching device 110 according to this embodiment. The conditions under which the measurement results shown in Figure 11 were obtained were that the roughened plate was moved back and forth once with an amplitude of 3 cm (K=3, N=1), and the movement speed was 1.5 back and forth / second. The weight 250 placed on the tip of the arm 230 was 1 kg. The arithmetic mean roughness of the roughened surface 221 of the scratching member 220 used to measure the scratch depth data of the scratches shown in Figure 11 was 1500 nm.

[0058] The scratch S4 has an overall uneven shape with a certain width. The width H4 of the scratch S4 is approximately 100 μm. The height D4 of the scratch S4 is approximately 4000 nm at its maximum. Thus, the scratch S4 made on the spectacle lens by the scratching device 110 has a maximum depth of approximately 4000 nm and has a relatively large single depression C4. Furthermore, the depression C4 has fine irregularities inside. In other words, the scratch S4 formed by the scratching device 110 is not simply a single smooth depression, but is characterized by having fine irregularities within a relatively large depression C4 with a certain width.

[0059] Here, comparing the scratch S4 formed by the scratching device 110 with the scratch S1 that occurs in daily life, it can be seen that the scratch shapes are similar. For example, both scratch S4 and scratch S1 have a width of approximately 100 μm and are very similar. Also, the height D4 of scratch S4 is 4000 nm, and the height D1 of scratch S1 is 5000 nm. Therefore, the heights of scratch S4 and scratch S1 are both on the order of magnitude, and both have indentations of very similar heights.

[0060] Furthermore, like scratch S1, scratch S4 has fine irregularities within the dent C4. In other words, scratch S4 is similar to scratch S1 in that it is not simply a single smooth dent, but rather a relatively large dent with width that has fine irregularities within it.

[0061] Figure 12 shows another example of scratch depth data for scratches made on eyeglass lenses using the scratching device 110 according to this embodiment. The scratching device 110 used in the measurement results shown in Figure 12 has an arithmetic mean roughness of 4100 nm on the rough surface 221 of the scratching member 220, and the other settings are the same as those of the scratching device 110 used in the measurement results shown in Figure 11. The scratch shape characteristics of scratch S5 shown in Figure 12 are almost the same as scratch S4, and are similar to scratches S1 that occur in daily life, indicating high reproducibility.

[0062] The scratch S5 has an overall uneven shape with a certain width. The width H5 of the scratch S5 is approximately 120 μm. Furthermore, the scratch S5 has a recess C5 with fine irregularities inside. In other words, the scratch S5 formed by the scratching device 110 is not simply a single smooth recess, but is characterized by having fine irregularities within a relatively large recess C5 with a certain width. However, since a rough surface plate with an arithmetic mean roughness of 4100 is used as the scratching member, the maximum height D5 of the scratch S5 is 19800 nm.

[0063] As described above, the scratch-resistant device 110 according to this embodiment uses a member having a rough surface 221 as a scratch-resistant member when forming scratches for evaluation of scratch resistance. With this configuration, it is possible to reproduce the shape of scratches that actually occur in daily life. The surface roughness parameter is not particularly limited, as long as it is a rough surface, but for example, by setting the arithmetic mean roughness of the rough surface 221 to within the range of at least 1500 nm to 4100 nm, it was experimentally confirmed that the shape of scratches that actually occur in daily life can be reproduced more accurately. Furthermore, by setting the maximum height roughness of the rough surface 221 to within the range of at least 9000 nm to 23500 nm, it was experimentally confirmed that the shape of scratches that actually occur in daily life can be reproduced more accurately. Furthermore, by setting the length of the irregularities of the rough surface 221 to within the range of 100 nm to 150 nm, it was experimentally confirmed that the shape of scratches that actually occur in daily life can be reproduced more accurately.

[0064] The scratching device 110 may have a plurality of scratching members 220. In this case, each of the plurality of scratching members 220 has a different surface roughness of the rough surface 221. Different surface roughness includes, for example, one or more of the arithmetic mean roughness Ra, maximum height Rz, and unevenness length Sm being different. The scratching device 110 may also store scratch depth data obtained using each of the plurality of scratching members 220 in advance. When reference data is input, the scratching device 110 may select the scratching member with the scratch depth data closest to the reference data from among the plurality of scratching members 220.

[0065] The scratching device 110 may notify the operator by displaying the selected scratching member 220 on a display screen or the like, or it may have a function to automatically attach the selected scratching member 220. The reference data is scratch depth data of scratches that occur in daily life, and may be data obtained, for example, by measuring scratches on eyeglass lenses provided by the wearer. Alternatively, the reference data may be data obtained by averaging multiple scratch depth data of scratches that occur in daily life.

[0066] In this embodiment, the scratch resistance evaluation test system 100 measures the depth of the scratch when evaluating scratch resistance, but is not limited to this. For example, the scratch resistance evaluation test system 100 may evaluate scratch resistance by forming scratches on the spectacle lens to be evaluated while changing the load of the weight 250, and determining the peeling load at which the peeling of the surface coating of the spectacle lens begins to occur. Thus, in this embodiment, the method of evaluating scratches formed by the scratching device 110 is not particularly limited, and scratches may be evaluated using known techniques.

[0067] Furthermore, the scratching device 110 of this embodiment forms scratches on the surface of the spectacle lens Ln by moving the scratching member 220 while the rough surface 221 of the scratching member 220 is in contact with the spectacle lens Ln, but is not limited to this. The scratching device 110 may move the lens holder 210 that holds the spectacle lens Ln while the rough surface 221 of the scratching member 220 is in contact with the spectacle lens Ln, or it may move both the lens holder 210 and the scratching member 220 relative to each other. That is, the control unit 262 may form scratches on the spectacle lens Ln by moving both or either the lens holder 210 and the scratching member 220 while the rough surface 221 is in contact with the spectacle lens Ln held by the lens holder 210.

[0068] The execution order of operations, procedures, steps, and stages in the devices, systems, programs, and methods shown in the claims, specifications, and drawings is not explicitly stated as "before," "prior to," etc. Furthermore, it should be noted that the execution order of each process can be implemented in any order, unless the output of a previous process is used in a later process. Even if the operation flow in the claims, specifications, and drawings is described using phrases such as "first," "next," etc., for convenience, this does not mean that it is essential to perform the operations in that order. Also, to the extent permitted by law, the disclosures of Japanese Patent Application No. 2024-168145 and all documents cited in the above embodiments are incorporated herein by reference and constitute part of the description.

[0069] 110... Scratching device, 210... Lens holder, 220... Scratching member, 260... Control device, Ln... Eyeglass lens, 221... Rough surface

Claims

1. A scratching device for forming scratches on an eyeglass lens in order to evaluate the scratch resistance of the eyeglass lens, comprising: a scratching member having a rough surface; a holding part for holding the eyeglass lens; and a control device for moving both or either the holding part and the scratching member while the rough surface is in contact with the eyeglass lens held by the holding part.

2. The scratching device according to claim 1, wherein the scratching member is supported such that the rough surface is parallel to the horizontal plane.

3. The scratching device according to claim 1, wherein the arithmetic mean roughness of the rough surface is set within the range of 1500 nm or more and 4100 nm or less.

4. The scratching device according to claim 3, wherein the maximum height roughness of the rough surface is set within the range of 9,000 nm or more and 23,500 nm or less.

5. The scratching device according to claim 4, wherein the length of the unevenness of the rough surface is set within the range of 100 nm or more and 150 nm or less.

6. The scratching device according to claim 1, wherein the scratching member is a plate member whose surface is the rough surface.

7. A method for forming scratches on an eyeglass lens using a scratch-scratching member, comprising: bringing a rough surface formed on the scratch-scratching member into contact with the eyeglass lens; and forming the scratches on the eyeglass lens by moving both or either the eyeglass lens and the scratch-scratching member while the rough surface is in contact with the eyeglass lens.

Images