Eyeglass lens processing device and processing control data creation program

Abstract

To provide a spectacle lens processing device which can properly process a lens peripheral edge so that occurence of lens distortion is suppressed when fitting lens to a rim, and a processing control data creation program.SOLUTION: A control part of a spectacle lens processing device executes a ball type acquisition step and a ball type correction step. At the ball type acquisition step, the control part acquires a ball type 10 of lens. At the ball type correction step, the control part corrects at least a part of a contour of the ball type 10 to an inner side on the basis of information that indicates a curvature of the ball type 10, thereby suppressing lens distortion when fitting the lens after processing to a rim.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to an eyeglass lens processing device capable of processing the periphery of an eyeglass lens, and a processing control data creation program for creating processing control data used in the eyeglass lens processing device. [Background technology]

[0002] Various methods have been proposed for processing the periphery of a lens to fit it into the rim of an eyeglass frame. For example, the eyeglass lens processing device described in Patent Document 1 determines whether the lens can be processed into a rim shape using only a large-diameter rim processing tool. If it is determined that processing using only a large-diameter rim processing tool is impossible, a small-diameter rim processing tool is used to additionally process the area that cannot be processed using a large-diameter rim processing tool to form a rim shape. As a result, a rim shape having a concave shape smaller than the diameter of the large-diameter rim processing tool is processed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-178432 Summary of the Invention [Problem to be solved by the invention]

[0004] Even when lenses are precisely machined according to the lens shape, stress applied by the rim can cause distortion in the lens when the machined lens is fitted into the rim of the frame. Lens distortion can cause defects such as changes in the optical properties of the lens and deterioration of the coating applied to the lens. To prevent lens distortion when the lens is fitted into the rim, workers could perform additional manual processing of the lens. However, performing additional manual processing requires skilled workers and increases the worker's workload.

[0005] A typical object of the present disclosure is to provide an eyeglass lens processing device and a processing control data creation program that can appropriately process the lens periphery so as to suppress distortion of the lens when the lens is fitted into the rim. [Means for solving the problem]

[0006] A typical embodiment of the present disclosure provides an eyeglass lens processing device that processes a periphery of a lens using a periphery processing tool that processes the periphery of the lens in order to fit the lens into a rim of an eyeglass frame, and a control unit of the eyeglass lens processing device executes a lens shape acquisition step that acquires a lens shape of the lens, and a lens shape correction step that corrects at least a part of the contour of the lens shape inward based on information indicating the curvature of the lens shape, thereby suppressing distortion of the lens when the processed lens is fitted into the rim. In the lens shape correction step, the shape of the lens whose curvature changes depending on the radius vector angle is displayed on a display unit based on information indicating the curvature of the lens, along with the position where the curvature is equal to or greater than a threshold value. For each region where the curvature of the lens is equal to or greater than the threshold value, an instruction from a user as to whether or not to correct the lens shape inward and the degree of correction if corrected is accepted, and at least a part of the contour of the lens shape is corrected inward in accordance with the instruction input by the user. .

[0007] A processing control data creation program provided by a typical embodiment of the present disclosure is a processing control data creation program executed by a data creation device to create processing control data used in an eyeglass lens processing device that processes the periphery of a lens to fit the lens into the rim of an eyeglass frame, and is executed by a control unit of the data creation device to cause the data creation device to execute a lens shape acquisition step of acquiring the lens shape, and a lens shape correction step of correcting at least a part of the contour of the lens shape inward based on information indicating the curvature of the lens shape, thereby suppressing distortion of the lens when the processed lens is fitted into the rim. In the lens shape correction step, the shape of the lens whose curvature changes depending on the radius vector angle is displayed on a display unit based on information indicating the curvature of the lens, along with the position where the curvature is equal to or greater than a threshold value. For each region where the curvature of the lens is equal to or greater than the threshold value, an instruction from a user as to whether or not to correct the lens shape inward and the degree of correction if corrected is accepted, and at least a part of the contour of the lens shape is corrected inward in accordance with the instruction input by the user. .

[0008] According to the eyeglass lens processing device and processing control data creation program of the present disclosure, the lens periphery is appropriately processed so as to suppress the occurrence of lens distortion when the lens is fitted onto the rim. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram of a processing mechanism of an eyeglass lens processing device 1. FIG. [Figure 2] 2 is a block diagram showing the electrical configuration of the eyeglass lens processing device 1. FIG. [Figure 3] 10 is a flowchart of a spectacle lens processing control process. [Figure 4] (A) is a plan view of the lens 10, (B) lens data of the lens 10, and (C) a comparison of curvature data of the lens 10. [Figure 5] FIG. 10 is a diagram showing a state in which the outline of the lens 10 in the range of radius vector angles of 90° to 180° has been corrected inward by the first automatic lens shape correction process. [Figure 6] 5 is a graph showing the results of correcting the lens shape 10 shown in FIGS. 4(A) to 4(C) so that the curvature of a portion where the curvature is equal to or greater than a threshold value T is reduced. [Figure 7] 5 is a graph showing the results of correcting the lens shape 10 shown in FIGS. 4(A) to 4(C) so that the curvature of the entire contour decreases smoothly. [Figure 8] 10A and 10B are diagrams showing an example of an image displayed on the display unit 7 when a manual lens shape correction process is executed. DETAILED DESCRIPTION OF THE INVENTION

[0010] <Summary> The eyeglass lens processing device exemplified in the present disclosure (a data creation device that creates processing control data) processes the periphery of a lens using a peripheral processing tool that processes the periphery of the lens in order to fit the lens into the rim of an eyeglass frame. The control unit of the eyeglass lens processing device executes a lens shape acquisition step and a lens shape correction step. In the lens shape acquisition step, the control unit acquires the lens shape. In the lens shape correction step, the control unit corrects at least a portion of the lens shape contour inward based on information indicating the curvature of the lens shape, thereby suppressing the occurrence of lens distortion when the processed lens is fitted into the rim.

[0011] As a result of various experiments and studies, the inventors of the present invention have newly discovered that stress that causes lens distortion is more easily applied to portions of the lens with a large curvature than portions of the lens with a small curvature.The eyeglass lens processing device exemplified in this disclosure corrects at least a portion of the lens contour inward based on information indicating the lens curvature, thereby suppressing the application of stress that causes lens distortion to the lens.As a result, the occurrence of lens distortion when the lens is fitted onto the rim is appropriately suppressed.

[0012] In the lens shape correction step, the control unit may correct at least a part of the outline of the lens shape inward based on at least one of the positions where the curvature of the lens shape, which changes depending on the radius vector angle, takes a maximum value. As described above, according to the new knowledge obtained by the inventor of the present invention, stress that causes lens distortion is likely to be applied to a portion where the curvature of the lens shape is large. Therefore, the control unit can appropriately correct the position of the lens shape that is likely to cause lens distortion by identifying the position where the curvature of the lens shape takes a maximum value and correcting the outline of the lens shape inward based on the identified position.

[0013] Note that curvature is a quantity that represents the degree of curvature of a curve (in this disclosure, the curve of the outline of the target lens). Curvature can be expressed in various units. For example, the reciprocal of curvature is the radius of curvature. Therefore, it is also possible to represent the degree of curvature of the curve of the outline of the target lens using the radius of curvature. In other words, in this disclosure, the term "large curvature" is synonymous with "small radius of curvature," and the term "small curvature" is synonymous with "large radius of curvature." Therefore, the position where the curvature of the target lens is at its maximum value coincides with the position where the radius of curvature of the target lens is at its minimum value.

[0014] A specific method for correcting the outline of the lens shape based on the position where the curvature takes a maximum value can be selected as appropriate. For example, the control unit may correct the outline of the lens shape so that at least one of the positions of one or more points where the curvature of the lens shape takes a maximum value is corrected to be more inward on the lens than the original position. In this case, stress that causes distortion of the lens is appropriately reduced. Furthermore, the control unit may correct the outline of a position adjacent to at least one of the points where the curvature of the lens shape takes a maximum value (referred to as "maximum point") to be more inward without changing the position of the point. In this case, stress applied to the lens from the rim near the maximum point is also reduced.

[0015] In the lens shape correction step, the control unit may correct the lens shape contour inward so as to reduce the curvature of the portion of the lens shape contour where the curvature is equal to or greater than the threshold. In this case, the curvature does not change in the portion of the lens shape contour where the curvature is less than the threshold. As a result, excessive correction of the lens shape is suppressed. Therefore, lens distortion is appropriately suppressed while suppressing a decrease in the lens holding force by the rim.

[0016] In the lens shape correction step, the control unit may correct the contour of the lens shape inward so that the greater the curvature of the lens shape, the greater the reduction in curvature of the lens shape after correction. According to new findings obtained by the inventors of the present invention, the greater the curvature of the lens shape, the more likely stress that causes lens distortion is applied. Therefore, by the control unit correcting the contour of the lens shape according to the magnitude of the curvature, lens distortion is more appropriately suppressed. Furthermore, by correcting the contour of the lens shape according to the magnitude of the curvature, the contour of the lens shape is smoothly corrected, making it less likely that excessive irregularities will be formed in the contour of the lens shape. Therefore, deterioration in the functionality and appearance of the eyeglasses caused by excessive irregularities in the contour of the lens shape is also suppressed.

[0017] The control unit may correct the outline of the target lens according to the magnitude of curvature for a portion of the outline of the target lens where the curvature is equal to or greater than a threshold value. In this case, both a decrease in the lens holding force by the rim and lens distortion are more appropriately suppressed. The control unit may also correct the outline of the target lens according to the magnitude of curvature for the entire outline of the target lens. In this case, lens distortion is also appropriately suppressed.

[0018] A specific method for correcting the outline of the target lens shape according to the magnitude of curvature can also be selected as appropriate. For example, the control unit may make the magnitude of the curvature of the target lens shape proportional to the amount of reduction in the curvature after correction.

[0019] In the lens shape correction step, the control unit may correct at least a portion of the lens shape contour inward by performing a smoothing process on the data indicating the lens shape curvature, smoothly reducing the curvature. In this case, by using a known smoothing process, both a decrease in the lens holding force by the rim and lens distortion are more appropriately suppressed. Furthermore, by using the smoothing process, the lens shape contour is smoothly corrected, making it difficult for excessive irregularities to form in the lens shape contour. Therefore, deterioration in the function and appearance of the eyeglasses caused by excessive irregularities in the lens shape contour is also suppressed.

[0020] The control unit may also perform curvature smoothing processing on portions of the outline of the target lens where the curvature is equal to or greater than a threshold value. In this case, both a decrease in the lens holding force due to the rim and lens distortion are more appropriately suppressed. The control unit can also perform curvature smoothing processing on the entire outline of the target lens. In this case, lens distortion is also appropriately suppressed.

[0021] It is also possible to change the specific method for correcting the outline of the target lens shape to the inside. For example, the control unit may correct the data indicating the target lens shape so that a portion of a graph showing the curvature data of the target lens shape, where the curvature is equal to or greater than a threshold, fits to the circumference of a circle of a predetermined shape. In other words, the control unit may correct the data indicating the target lens shape so that the maximum value of the curvature of the target lens shape is limited to a threshold or less. Even in this case, both the reduction in the lens holding force due to the rim and the distortion of the lens are appropriately suppressed. Furthermore, the outline of the target lens shape is smoothly corrected.

[0022] In the lens shape correction step, the control unit may accept an input of an instruction from a user to correct at least a part of the contour of the lens shape while displaying on the display unit the shape of the lens shape whose curvature changes depending on the radius vector angle based on the information indicating the curvature of the lens shape. The control unit may correct at least a part of the contour of the lens shape inward in accordance with the instruction input by the user. In this case, the user can correct a position of the contour of the lens shape that is likely to cause lens distortion inward at their own discretion.

[0023] The user may specify the position where the outline of the target lens is to be corrected inward and the amount of correction to the inward. The control unit may correct the position of the outline of the target lens specified by the user inward by the specified amount of correction. In this case, the user can correct the outline of the target lens more precisely.

[0024] In the target lens shape correction step, the control unit may display at least one of a position where the curvature of the target lens shape, which changes depending on the radius vector angle, is at a maximum value and a position where the curvature is equal to or greater than a threshold value, together with the target lens shape on the display unit. In this case, the user can determine whether to correct the target lens shape after properly understanding positions on the target lens shape contour that are likely to cause lens distortion.

[0025] The control unit may receive an input of an instruction from a user to specify whether or not to execute the lens shape correction step. The control unit may determine whether or not to execute the lens shape correction step according to the input instruction. The influence of lens distortion varies depending on various circumstances (for example, whether or not the lens is coated). Therefore, the user can cause the eyeglass lens processing apparatus to perform more appropriate processing by specifying whether or not to execute the lens shape correction step according to the circumstances.

[0026] <Embodiment> A typical embodiment of the present disclosure will be described below with reference to the drawings. First, an eyeglass lens processing apparatus 1 of this embodiment will be described. The eyeglass lens processing apparatus 1 processes an eyeglass lens LE in accordance with processing control data for processing the periphery of the lens LE along the lens shape. The eyeglass lens processing apparatus 1 of this embodiment also serves as a data creation device that creates the processing control data. However, a data creation device (e.g., a personal computer) separate from the eyeglass lens processing apparatus 1 may also be used.

[0027] (mechanical configuration) 1, the eyeglass lens processing apparatus 1 of this embodiment includes a lens holding unit 100, a lens shape measuring unit 200, a first processing tool unit 300, and a second processing tool unit 400. The lens holding unit 100 includes lens holding shafts (lens chuck shafts) 102R and 102L that sandwich and hold the lens LE. Furthermore, the lens holding unit 100 includes a lens rotation unit 100a, a holding shaft moving unit 100b, and an axis distance changing unit 100c.

[0028] The lens rotation unit 100a rotates the pair of lens holding shafts 102R, 102L around their axes. The holder shaft moving unit 100b moves the lens holding shafts 102R, 102L in the axial direction (this is referred to as the X direction). The inter-shaft distance varying unit 100c moves the lens holding shafts 102R, 102L in a direction (this is referred to as the Y direction) toward or away from the rotation axes of the processing tools (details will be described later) provided on each of the first processing tool unit 300 and the second processing tool unit 400. The inter-shaft distance varying unit 100c also varies the distance between the lens shape measuring unit 200 and the lens holding shafts 102R, 102L.

[0029] Below, a detailed description will be given of specific examples of each component of the eyeglass lens processing apparatus 1. The lens holding part 100 is mounted on a base 170 of the main body of the eyeglass lens processing apparatus 1.

[0030] The lens rotation unit 100a will now be described. A lens holding shaft 102R is held on the right arm 101R of the carriage 101 of the lens holder 100, and a lens holding shaft 102L is held on the left arm 101L so that they are rotatable and coaxial with each other. When the lens holding shaft 102R is moved toward the lens holding shaft 102L by a motor 110 attached to the right arm 101R, the lens LE is sandwiched and held between the two lens holding shafts 102R and 102L. The two lens holding shafts 102R and 102L are rotated in synchronization by a motor 120 attached to the right arm 101R.

[0031] The holder shaft moving unit 100b will now be described. An X-axis moving support base 140 is provided on shafts 103 and 104 that extend parallel to the lens holder shafts 102R and 102L and the grindstone rotation shaft 161a. The X-axis moving support base 140 can move in the X-axis direction along the shafts 103 and 104 by the power of an X-axis moving motor 145. The carriage 101 is mounted on the X-axis moving support base 140. An encoder 146 (see FIG. 2) is provided on the rotation shaft of the X-axis moving motor 145. In this embodiment, the positions of the lens holder shafts 102R and 102L in the X direction detected by the encoder 146 are used to measure the shapes of the front and rear surfaces of the lens LE.

[0032] The axis-to-axis distance varying unit 100c will now be described. A shaft 156 extending in a direction connecting the lens holding shafts 102R, 102L and the grindstone rotation shaft 161a is fixed to the X-axis movement support base 140. When the Y-axis movement motor 150 rotates, a ball screw 155 extending in the Y direction rotates. As a result, the carriage 101 moves in the Y-axis direction along the shaft 156. An encoder 158 that detects the position of the carriage 101 in the Y direction is provided on the rotation shaft of the Y-axis movement motor 150.

[0033] The lens shape measuring unit 200 will now be described. In this embodiment, the lens shape measuring unit 200 is fixed to the base 170 at a position opposite the first processing tool unit 300 via the carriage 101. The lens shape measuring unit 200 includes a lens edge position measuring unit 200F and a lens edge position measuring unit 200R. The lens edge position measuring unit 200F has a stylus that contacts the front surface of the lens LE. The lens edge position measuring unit 200R has a stylus that contacts the rear surface of the lens LE. With the stylus of each of the lens edge position measuring units 200F and 200R in contact with the front and rear surfaces of the lens LE, the carriage 101 is moved in the Y-axis direction based on target lens shape data, and the lens holding shafts 102R and 102L are rotated, thereby simultaneously measuring the edge positions of the front and rear surfaces of the lens LE. The lens shape measuring unit 200 functions as a lens thickness measuring unit that measures the thickness of the lens LE. The lens edge position measuring units 200F and 200R may be configured as described in, for example, Japanese Patent Application Laid-Open No. 2003-145328.

[0034] The first processing tool unit 300 will be described. The first processing tool unit 300 is equipped with a lens edge processing tool 168, which is one of the lens processing tools. The lens edge processing tool 168 of this embodiment includes a rough grindstone 162 for glass, a finishing grindstone 164 having a V-groove (bevel groove) for forming a bevel on the lens and a flat processing surface, a flat mirror-finishing grindstone 165, a finishing grindstone 166 for high-curve lenses, and a rough grindstone 167 for plastics. The multiple grindstones of the lens edge processing tool 168 are coaxially attached to a grindstone rotation shaft (grindstone spindle) 161a. The grindstone rotation shaft 161a is rotated by a motor 160. The lens LE held by the lens holding shafts 102L and 102R has its edge pressed against the lens edge processing tool 168 and processed.

[0035] The second processing tool unit 400 will be described. The second processing tool unit 400 includes a finishing tool, a drilling tool, a motor 421, and a motor 482. The finishing tool rotates around a rotation axis to perform finishing on the peripheral edge of the lens LE (for example, at least one of grooving, bevel forming, step forming, etc.). The drilling tool forms a hole in the lens LE. The drilling tool of this embodiment moves axially while rotating around the rotation axis to form a hole extending in the axial direction in the lens LE. The motor 421 rotates the finishing tool and the drilling tool. The motor 482 pivots the finishing tool and the drilling tool.

[0036] (Electrical configuration) The electrical configuration of the eyeglass lens processing apparatus (which also serves as a data creation apparatus) 1 will be described with reference to Figure 2. The eyeglass lens processing apparatus 1 includes a CPU (processor) 2 that controls the eyeglass lens processing apparatus 1. A RAM 3, a ROM 4, a non-volatile memory 5, an operation unit 6, a display unit (display) 7, and an external communication I / F 8 are connected to the CPU 2 via a bus. Furthermore, various devices such as the motors mentioned above (motor 110, motor 120, X-axis movement motor 145, Y-axis movement motor 150, motor 160, motor 421, motor 482, encoder 146, encoder 158) are connected to the CPU 2 via a bus.

[0037] The RAM 3 temporarily stores various types of information. The ROM 4 stores various programs, initial values, etc. The non-volatile memory 5 is a non-transitory storage medium (e.g., flash ROM, hard disk drive, etc.) that can retain stored contents even when the power supply is cut off. The non-volatile memory 5 may store a control program (e.g., a processing control data creation program, etc.) for controlling the operation of the eyeglass lens processing apparatus (data creation apparatus) 1. The operation unit 6 accepts input of various instructions from an operator (user of the apparatus). For example, a touch panel provided on the surface of the display unit 7, operation buttons, etc. may be used as the operation unit 6. The external communication I / F 8 connects the eyeglass lens processing apparatus 1 to external devices.

[0038] The CPU 2 controls the driving of various motors and the like in accordance with the processing control data to appropriately process the lens LE. As an example, in this embodiment, the eyeglass lens processing apparatus 1 itself creates the processing control data. More specifically, in this embodiment, the control unit (including the CPU 2) of the eyeglass lens processing apparatus 1 executes a processing control data creation program to create at least a portion of the processing control data. In other words, in this embodiment, the eyeglass lens processing apparatus 1 also serves as a data creation device that creates the processing control data. However, a device other than the eyeglass lens processing apparatus 1 may function as the data creation device. For example, a personal computer connected to the eyeglass lens processing apparatus 1 may function as the data creation device. In this case, the control unit of the personal computer executes the processing control data creation program to create the processing control data.

[0039] (control processing) 3 to 8, the eyeglass lens processing control process executed by the eyeglass lens processing apparatus 1 of this embodiment will be described. When a trigger to start processing the lens LE is input, the CPU 2 of the eyeglass lens processing control process executes the eyeglass lens processing control process shown in FIG. 3 in accordance with the control program stored in the nonvolatile memory 5.

[0040] As described above, in this embodiment, the eyeglass lens processing apparatus 1 also functions as a data creation device. Therefore, the eyeglass lens processing control process illustrated in FIG. 3 includes both a process for creating processing control data (S1 to S7) and a process for processing the lens LE based on the processing control data. Part of the processing control data creation process in this embodiment includes a process for correcting at least a portion of the outline of the lens shape inward (hereinafter referred to as "lens shape correction process") in order to suppress distortion of the lens LE when the processed lens LE is fitted onto the rim. Note that "inner side" refers to the side closer to the center of the lens LE than the outline of the lens shape before correction. The "inner side" can also be expressed as the inside in the radial direction of the lens LE.

[0041] First, the CPU 2 acquires data on the lens shape of the lens LE to be processed (S1). The lens shape data may be generated, for example, by measuring the shape of the rim of the frame (eyeglasses frame) to which the lens LE is attached using an eyeglasses frame shape measuring device (not shown), or may be provided by a manufacturer that manufactures the frame. Alternatively, the lens shape data may be generated by measuring the shape of a demo lens that corresponds to the shape of the rim. As will be described in detail later, the lens shape data in this embodiment is represented by a radius vector angle and a radius vector length based on a reference point of the lens shape (for example, the geometric center of the lens shape) (see FIGS. 4(A) and (B)).

[0042] Next, the CPU 2 determines whether or not an instruction to execute the rim shape correction process has been input by the user (S2). In this embodiment, the user can input an instruction as to whether or not to execute the rim shape correction process for suppressing the occurrence of distortion of the lens LE to the eyeglass lens processing apparatus 1 via the operation unit 6 or the like. If an instruction to execute the rim shape correction process has not been input (S2: NO), the rim shape data acquired in S1 is not corrected, and the process proceeds directly to S7.

[0043] If an instruction to execute the rim shape correction process has been input (S2: YES), the CPU 2 determines whether an instruction to automatically correct the rim shape has been input (S3). In this embodiment, the user can input an instruction to execute the rim shape correction process automatically or manually to the eyeglass lens processing apparatus 1 via the operation unit 6 or the like. If an instruction to execute the automatic correction has been input (S3: YES), the CPU 2 executes the rim shape automatic correction process (S4). Also, if an instruction to execute the manual correction has been input (S3: NO), the CPU 2 executes the rim shape manual correction process (S5). Details of the rim shape automatic correction process and the rim shape manual correction process will be described later with reference to FIGS. 4 to 8.

[0044] Next, the CPU 2 creates data for processing a bevel on the periphery of the lens LE based on the lens shape data obtained in S1 to S5 (the lens shape data acquired in S1 or the lens shape data corrected in S4 and S5) (S7). As a result, processing control data for processing the lens LE is completed. Thereafter, the CPU 2 controls various motors and the like (for example, at least one of motors 110, 120, 145, 150, 160, etc.) based on the processing control data to move the relative position between the lens LE held by the lens holding shafts 102R and 102L and the periphery processing tool 168, and processes the lens LE with the periphery processing tool 168. The lens shape correction process (S4, S5) will be described in detail below.

[0045] (Lens shape, Lens shape data, Lens shape curvature data) First, an example of the lens shape, lens shape data, and curvature data of the lens LE will be described with reference to Fig. 4. Fig. 4(A) is a plan view of the lens shape 10. The center of the coordinates is aligned with the reference point of the lens shape 10 (the geometric center of the lens shape 10 in Fig. 4). Fig. 4(B) is a graph of the lens shape data of the lens shape 10 with the horizontal axis representing the radius vector angle and the vertical axis representing the radius vector length. Fig. 4(C) is a graph of the curvature data of the lens shape 10 with the horizontal axis representing the radius vector angle and the vertical axis representing the lens curvature.

[0046] As shown in FIG. 4(B), the lens shape data of this embodiment is expressed, for example, by a radius vector angle and a radius vector length based on a reference point of the lens 10. That is, in the lens shape data of this embodiment, information on the distance from the reference point to the contour of the lens 10 is recorded for each radius vector angle. Furthermore, in the lens shape correction process of this embodiment, curvature data of the lens 10 is used. As shown in FIG. 4(C), in the curvature data of the lens 10, information on the curvature of the contour of the lens 10 is recorded for each radius vector angle. The curvature data of the lens 10 shown in FIG. 4(C) can be calculated from the lens shape data shown in FIG. 4(B).

[0047] Curvature is a quantity that represents the degree of curvature of a curve (in this disclosure, the curve of the contour of the lens 10). Therefore, in this embodiment, the degree of curvature of the curve of the contour of the lens 10 shown in FIG. 4(A) is greater in the area of ​​large curvature shown in FIG. 4(C). Note that the degree of curvature of the contour of the lens 10 can also be represented using the radius of curvature (the reciprocal of the curvature). In this case, the graph in FIG. 4(C) is upside down.

[0048] In the lens 10 shown in Fig. 4(A), there are portions where the curvature increases in each of the radius vector angle ranges of 0° to 90°, 90° to 180°, 180° to 270°, and 270° to 360°. Therefore, as shown in Fig. 4(C), the curvature of the lens 10 has maximum values ​​at four positions. In the example shown in Fig. 4(C), the maximum value in the radius vector angle range of 0° to 90° is M1, the maximum value in the range of 90° to 180° is M2, the maximum value in the range of 180° to 270° is M3, and the maximum value in the range of 270° to 360° is M4.

[0049] (First automatic lens shape correction process) The first automatic lens shape correction process (S4) will be described with reference to Fig. 5. In the first automatic lens shape correction process, the CPU 2 identifies at least one of the positions where the curvature of the lens shape 10, which changes depending on the radius vector angle, takes a maximum value (M1 to M4). The CPU 2 corrects the outline of the lens shape 10 to the inside of the lens LE based on the identified position.

[0050] Fig. 5 is a diagram showing a state in which the contour of the lens 10 in the radius vector angle range of 90° to 180° has been corrected inward by the first automatic lens shape correction process. In the example shown in Fig. 5, first, the CPU 2 identifies the maximum point PA2, which is the position of the lens 10 where the curvature takes on the maximum value M2 (see Fig. 4(C)). The CPU 2 corrects the lens shape data (contour of the lens 10) so that the identified maximum point PA2 moves to a position PB2 that is inside the lens from its original position (the position on the contour indicated by the dotted line in Fig. 5). As a result, stress that causes distortion of the lens LE when the lens LE is fitted onto the rim is appropriately reduced.

[0051] In this embodiment, the CPU 2 corrects the contour of the lens 10 inward for all positions where the curvature of the lens 10 takes on a maximum value (four positions corresponding to the four maximum values ​​M1 to M4 in this embodiment). This more appropriately suppresses distortion of the lens LE. However, the CPU 2 may correct the contour of the lens 10 inward only for some of the positions where the curvature takes on a maximum value.

[0052] 5, in the first automatic lens shape correction process of this embodiment, the CPU 2 corrects inward a portion of the contour of the lens 10 that is within an area R that is centered on the identified maximum point PA2 and has a predetermined radius. The radius of the area R may be a predetermined fixed value or may be changed by the user. In detail, the CPU 2 corrects the contour of the lens 10 smoothly so that unnecessary irregularities do not occur in the contour of the lens 10 after correction (that is, so that the curvature of the lens 10 does not increase excessively at the correction location).

[0053] However, it is also possible to change the method for correcting the contour of the lens shape 10 based on the maximum point. For example, the CPU 2 may correct the contour of the position adjacent to the maximum point inward without changing the position of the maximum point. Even in this case, the stress applied to the lens from the rim near the maximum point decreases.

[0054] (Second automatic lens correction process) The second automatic lens shape correction process (S4) will be described with reference to Fig. 6. In the second automatic lens shape correction process, the CPU 2 corrects the contour of the lens 10 inward so as to reduce the curvature of a portion of the contour of the lens 10 whose curvature is equal to or greater than a threshold value.

[0055] FIG. 6 is a graph showing the result of correcting the lens shape 10 shown in FIGS. 4(A) to (C) so that the curvature of a portion where the curvature is equal to or greater than the threshold T decreases. In FIG. 6, the horizontal axis represents the radius vector angle, the vertical axis represents the curvature of the lens shape, and the dotted line represents the graph before correction, while the solid line represents the graph after correction. As shown in FIG. 6, in the second automatic lens shape correction process, the CPU 2 corrects the outline of the lens shape 10 inward so that the curvature of a portion where the curvature is equal to or greater than the threshold T decreases smoothly. In this case, in the outline of the lens shape 10, the curvature of a portion where the curvature is less than the threshold T does not change before and after correction. Therefore, distortion of the lens LE is suppressed while excessive correction of the lens shape 10 is suppressed.

[0056] After correcting the curvature data of the lens 10, the CPU 2 calculates the lens data from the curvature data after correction, thereby obtaining the lens data after contour correction. Similar processing is executed hereinafter.

[0057] The second automatic lens shape correction process will be described in detail. The CPU 2 corrects the contour of the lens shape 10 inward for a portion where the curvature is equal to or greater than the threshold value T so that the greater the curvature of the lens shape 10, the greater the reduction in curvature of the lens shape 10 after correction. As a result, distortion of the lens LE is more appropriately suppressed. Furthermore, when correction of the contour of the lens shape 10 is performed according to the magnitude of the curvature, the contour of the lens shape 10 is smoothly corrected, making it less likely that excessive irregularities will be formed in the contour of the lens shape 10.

[0058] Furthermore, the CPU 2 can correct at least a portion of the contour of the lens 10 inward by performing a known smoothing process that smoothly reduces the curvature for a portion of the curvature data of the lens 10 where the curvature is equal to or greater than the threshold T. That is, the CPU 2 can correct the contour of the lens 10 by performing a smoothing process on a portion of the curvature data where the curvature is equal to or greater than the threshold T and calculating the lens data from the obtained curvature data. In this case, by using a known smoothing process, both a decrease in the holding force of the lens LE by the rim and distortion of the lens LE are more appropriately suppressed. Furthermore, by using the smoothing process, the contour of the lens 10 is smoothly corrected, making it less likely that excessive irregularities will be formed in the contour of the lens 10.

[0059] The CPU 2 can also correct the lens shape data so that the portion of the graph of the curvature data of the lens shape 10 where the curvature is equal to or greater than the threshold T fits to the circumference of a circle of a predetermined shape (a perfect circle or an ellipse). In other words, the CPU 2 can correct the curvature data so that the maximum value of the curvature of the lens shape 10 is limited to a threshold or less, and calculate the lens shape data from the corrected curvature data, thereby correcting the contour of the lens shape 10. Even in this case, both the reduction in the holding force of the lens LE by the rim and distortion of the lens LE are appropriately suppressed. Furthermore, the contour of the lens shape 10 is smoothly corrected.

[0060] (Third lens automatic correction processing) The third automatic lens shape correction process (S4) will be described with reference to FIG. 7. In the third automatic lens shape correction process, the CPU 2 corrects the lens shape data so that the overall curvature of the lens shape 10 decreases smoothly. FIG. 7 is a graph showing the result of correcting the lens shape 10 shown in FIGS. 4(A) to (C) so that the curvature of the entire contour decreases smoothly. In FIG. 7, the horizontal axis represents the radius vector angle and the vertical axis represents the lens shape curvature, with the graph before correction indicated by a dotted line and the graph after correction indicated by a solid line. As shown in FIG. 7, even when the curvature of the entire contour decreases smoothly, distortion of the lens LE is appropriately suppressed.

[0061] In detail, the CPU 2 can correct the contour of the lens 10 inward so that the greater the curvature of the lens 10 over the entire contour, the greater the reduction in curvature of the lens 10 after correction. The CPU 2 can also perform curvature smoothing processing on the entire contour of the lens 10. In either case, the contour of the lens 10 is smoothly corrected.

[0062] (Manual lens correction processing) The manual lens shape correction process (S5) will be described with reference to FIG. 8. In the manual lens shape correction process, the CPU 2 accepts input of instructions from the user to correct at least a portion of the contour of the lens 10 while displaying the shape of the lens 10, whose curvature changes depending on the radius vector angle, on the display unit 7. After checking the shape of the lens 10 displayed on the display unit 7, the user inputs the position at which the lens 10 is to be corrected inward and the amount of inward correction to the eyeglass lens processing apparatus 1 via the operation unit 6 or the like. The CPU 2 corrects at least a portion of the contour of the lens 10 inward in accordance with the instructions input by the user. This allows the user to correct the contour of the lens 10 more precisely.

[0063] In detail, in the manual lens shape correction process of this embodiment, the CPU 2 displays positions where the curvature of the lens 10 takes a maximum value (maximum points indicated by white circles in FIG. 8, corresponding to the maximum values ​​M1 to M4 shown in FIG. 4C) on the display unit 7 together with the shape of the lens 10. The CPU 2 also displays positions where the curvature of the lens 10 is equal to or greater than the threshold value T (four areas AREA1, AREA2, AREA3, and AREA4 surrounded by frames attached to the lens 10 in FIG. 8) on the display unit 7 together with the shape of the lens 10. Therefore, the user can determine whether or not to correct the lens 10 after properly understanding positions on the contour of the lens 10 that are likely to cause distortion of the lens LE.

[0064] In this embodiment, the user can specify whether to correct the lens shape 10 inward for each area (AREA1 to AREA4 in FIG. 8) where the curvature of the lens shape 10 is equal to or greater than the threshold value T, and the degree of correction if correction is to be made. In the example shown in FIG. 8, if the lens shape 10 is not to be corrected, "0" is input. If the lens shape 10 is to be corrected, one of "1" to "5" is input depending on the degree of correction. The CPU 2 executes the correction process for the lens shape 10 according to the input instruction using at least one of the correction methods described in the automatic lens shape correction process (S4) described above. Therefore, the user can easily and appropriately input a correction instruction for the lens shape 10.

[0065] However, it is also possible to change the method by which the user inputs correction instructions for the lens shape 10. For example, the user may input correction instructions for the lens shape 10 by moving any position on the outline of the displayed lens shape 10 inward by any amount using an operation such as click and drag.

[0066] The techniques disclosed in the above embodiments are merely examples. Therefore, it is possible to change the techniques exemplified in the above embodiments. For example, it is possible to execute only a part of the techniques exemplified in the above embodiments. Specifically, the eyeglass lens processing apparatus 1 may execute only one of the automatic lens shape correction process (S4) and the manual lens shape correction process (S5). Furthermore, the CPU 2 may change the degree of correction of the lens shape 10 according to instructions input by the user.

[0067] The process of acquiring data on the lens shape 10 in S1 of Fig. 3 is an example of a “lens shape acquisition step.” The process of correcting the outline of the lens shape 10 to the inside in S4 and S5 of Fig. 3 is an example of a “lens shape correction step.” [Explanation of symbols]

[0068] 1 Eyeglass lens processing equipment (data creation equipment) 2 CPU 5 Non-volatile memory 6 Control section 7 Display section 10 Ball shape 168 Edge processing tool

Claims

1. An eyeglass lens processing device that processes a periphery of a lens by a periphery processing tool that processes the periphery of the lens in order to fit the lens into a rim of an eyeglass frame, The control unit of the eyeglass lens processing device a target lens shape acquisition step of acquiring a target lens shape of the lens; a lens shape correction step of correcting at least a part of the contour of the lens shape inward based on information indicating the curvature of the lens shape, thereby suppressing distortion of the lens when the processed lens is fitted into the rim; Run In the target lens shape correction step, Based on the information indicating the curvature of the lens shape, the shape of the lens shape whose curvature changes depending on the radius vector angle is displayed on a display unit together with the position where the curvature is equal to or greater than a threshold value, For each region where the curvature of the lens shape is equal to or greater than the threshold value, an input of an instruction from a user as to whether or not to correct the lens shape inward and the degree of correction if corrected is received; An eyeglass lens processing device, characterized in that at least a part of the outline of the lens shape is corrected inward in accordance with an instruction input by a user.

2. The eyeglass lens processing apparatus according to claim 1, The control unit, in the target lens shape correction step, At least one of the positions where the curvature of the lens shape, which changes depending on the radius vector angle, takes a maximum value is identified, and the outline of the lens shape is corrected inward based on the identified position.

3. A processing control data creation program executed by a data creation device to create processing control data used in an eyeglass lens processing device that processes a periphery of a lens to fit the lens into a rim of an eyeglass frame, comprising: When executed by the control unit of the data creation device, a target lens shape acquisition step of acquiring a target lens shape of the lens; a lens shape correction step of correcting at least a part of the contour of the lens shape inward based on information indicating the curvature of the lens shape, thereby suppressing distortion of the lens when the processed lens is fitted into the rim; causing the data creation device to execute the above; In the target lens shape correction step, Based on the information indicating the curvature of the lens shape, the shape of the lens shape whose curvature changes depending on the radius vector angle is displayed on a display unit together with the position where the curvature is equal to or greater than a threshold value, For each region where the curvature of the lens shape is equal to or greater than the threshold value, an input of an instruction from a user as to whether or not to correct the lens shape inward and the degree of correction if corrected is received; A processing control data creation program, characterized in that at least a part of the outline of the target lens shape is corrected inward in accordance with an instruction input by a user.

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