JP2016090682A - Lens design method, lens manufacturing method, lens design program, and lens design system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens design method that can select an amount of prism having an optical performance reflected.SOLUTION: A lens design method includes: condition setting processing (S1) of setting a plurality of candidate values of an amount of prism of a first surface on an object side of a progress refractive power lens and a second surface on an eyeball side thereof on the basis of a prescription value of a wearer; shape determination processing (S2) of determining a shape of the progressive refractive power lens using the prescription value with respect to each of the plurality of candidate values; performance calculation processing (S3) of calculating optical performance information on the progressive refractive power lens having the shape thereof determined by the shape determination processing with respect to each of the plurality of candidate values; and performance index calculation processing (S4) of calculating a performance index value indicative of a change in the optical performance information depending upon the amount of prism.SELECTED DRAWING: Figure 2

Description

The present invention relates to a lens design method, a lens manufacturing method, a lens design program, and a lens design system.

  Progressive power lenses are used for spectacle lenses having a distance portion and a near portion. Generally, the distance portion is disposed on the upper side during wearing, and the near portion is disposed on the lower side when wearing. In the progressive-power lens, since the distance power and the near power are different, the edge thickness on the lower end side tends to be thinner than the edge thickness on the upper end side. An edge having an edge thickness of 0.1 mm or less is called a knife edge or the like. If the edge is a knife edge, the abrasive or the lens may be damaged in the process of manufacturing a progressive-index lens due to contact between the abrasive and the edge during surface polishing, for example. As described above, since the thickness of the lower end of the lens is limited, it is difficult to reduce the distance (center thickness) between the object-side surface and the eyeball-side back surface at the lens center.

  Therefore, a technique is used in which at least one of the front surface and the back surface is inclined so that the edge on the lower end side widens, and the front surface and the back surface are brought closer. This technique is called Prism-Thinning. A progressive-power lens (hereinafter abbreviated as PT lens) subjected to prism thinning has a refractive power that is higher than that of a progressive-power lens (hereinafter abbreviated as NPT lens) not subjected to prism thinning. An offset is added. This offset (hereinafter referred to as prism amount) is an amount corresponding to the inclination between the front surface and the back surface. The amount of prism corresponds to 1 dp (diopter), for example, when the light beam that has passed through the PT lens is shifted by 1 cm 1 m ahead.

  A fixed value is generally used for the prism amount, but a variable value may be used (see, for example, Patent Document 1 and Patent Document 2). Patent Document 1 proposes that when the amount of prism is different between the left-eye lens and the right-eye lens, the average prism amount is applied to both eyes. Patent Document 2 proposes changing the shape of the eyeball side surface according to the prism amount.

JP-A-5-341238 Japanese Patent Laid-Open No. 2003-121801

  By the way, the optical performance such as aberration distribution and frequency distribution obtained with reference to a certain amount of thinning prism tends to deteriorate as the amount of thinning prism greatly deviates from the reference. Therefore, for example, if the amount of prism is determined by focusing only on the lens thickness, in an extreme case, the optical performance may deviate from the allowable range for the target value. The present invention has been made in view of the above circumstances, and an object thereof is to provide a lens design method, a lens manufacturing method, a lens design program, and a lens design system capable of selecting a prism amount in consideration of optical performance. .

  According to the first aspect of the present invention, a plurality of candidate values for the prism amounts of the first surface on the object side and the second surface on the eyeball side of the progressive-power lens are set based on the prescription value of the wearer. A shape setting process that determines the shape of the progressive addition lens using a prescription value for each of a plurality of candidate values, and a shape determination process for each of the plurality of candidate values. A lens design method including: a performance calculation process for calculating optical performance information of a progressive-power lens for which the optical power is determined; and a performance index calculation process for calculating a performance index value indicating a change in optical performance information depending on a prism amount. Is done.

  According to a second aspect of the present invention, there is provided a lens manufacturing method including designing a progressive power lens by the lens design method of the first aspect and manufacturing a progressive power lens according to the design. The

  According to the third aspect of the present invention, a plurality of candidates for the prism amounts of the first surface on the object side and the second surface on the eyeball side of the progressive-power lens are stored in the computer based on the prescription value of the wearer. A condition setting process for setting a value, a shape determination process for determining the shape of the progressive addition lens using a prescription value for each of a plurality of candidate values, and a shape determination for each of a plurality of candidate values A lens design that executes a performance calculation process that calculates optical performance information of a progressive-power lens whose shape has been determined by the process, and a performance index calculation process that calculates a performance index value indicating a change in the optical performance information depending on the prism amount A program is provided.

  According to the fourth aspect of the present invention, based on the prescription value of the wearer, a plurality of candidate values for the prism amounts of the first surface on the object side and the second surface on the eyeball side of the progressive-power lens are set. A shape setting unit that determines the shape of the progressive-power lens using a prescription value for each of a plurality of candidate values, and a shape determining unit for each of the plurality of candidate values. Provided by a lens design system, including a performance calculation unit that calculates optical performance information of a progressive-power lens for which the optical power is determined, and a performance index calculation unit that calculates a performance index value indicating a change in optical performance information depending on a prism amount Is done.

  According to the present invention, it is possible to provide a lens design method, a lens manufacturing method, a lens design program, and a lens design system capable of selecting a prism amount in consideration of optical performance.

It is a figure which shows the example of the lens for spectacles. It is a flowchart which shows a lens design method and a lens manufacturing method. It is a conceptual diagram of the prism amount database used for condition setting processing. It is a flowchart which shows an example of a shape determination process. It is a flowchart which shows the other example of a shape determination process. It is a figure which shows an example of optical performance information. It is a conceptual diagram which shows the database for evaluation used by a performance parameter | index calculation process. It is a conceptual diagram which shows the data for evaluation used by a performance parameter | index calculation process. It is a conceptual diagram which shows a performance parameter | index calculation process. It is a conceptual diagram which shows the thickness parameter | index calculation process using center thickness. It is a conceptual diagram which shows the thickness parameter | index calculation process using designated thickness. It is a conceptual diagram which shows the thickness parameter | index calculation process using the thickness difference of an upper-lower end. It is a conceptual diagram which shows the database for evaluation used by evaluation processing. It is a conceptual diagram which shows an evaluation process. It is a conceptual diagram which shows an evaluation process. It is a figure which shows a lens design system.

  Hereinafter, embodiments will be described with reference to the drawings. Prior to the description of the lens design method according to this embodiment, a spectacle lens will be described. FIG. 1 is a diagram illustrating an example of a spectacle lens. FIG. 1A shows a plan view of a lens blank La, a lens Lb formed into a processing shape, and a lens Lc processed into the same shape as a spectacle frame. FIG. 1B shows a cross-sectional view of the lens Lb along the line AA in FIG.

  In the following description, the horizontal direction during wearing is defined as the X direction, and the vertical direction during wearing is defined as the Y direction. A direction perpendicular to the X direction and the Y direction is taken as a Z direction. The Z direction is, for example, the thickness direction of the lens. In FIG. 1A, the lens Lb is a lens for the left eye, and the + X side corresponds to the nose side, and the −X side corresponds to the ear side. The + Y side corresponds to the forehead side, and the -Y side corresponds to the chin side. The spectacle lens for the right eye is symmetrical with that for the left eye, and a description thereof will be omitted.

  The lens blank La is sometimes referred to as a blank lens, a lens block, or the like, and is a lens that serves as a spectacle lens. The lens blank La is formed into a spectacle lens by shape processing such as cutting and polishing. The lens blank La is formed of, for example, plastic or glass. The lens blank La is a lens formed in a circular shape in plan view. The lens blank La has a geometric center O.

  The lens Lb is called a processed shape lens or the like, and is a lens obtained by processing the peripheral portion of the lens blank La by grinding or the like while leaving a region PA to which a jig or the like is attached during lens processing. The region PA is a region where an adhesive such as an alloy is formed when the surface is ground or polished, for example. The lens Lb is set to a region including the region Lc and the region PA used for processing when viewed in plan from the thickness direction. The planar shape of the lens Lb is, for example, an ellipse, but may be an ellipse.

  The lens Lc is a lens processed into almost the same shape as the finished spectacle lens. The lens Lc has a predetermined optical center P. The optical center P is formed, for example, at a position that matches the fitting point of the wearer, but may be formed at a position that is shifted from the fitting point in at least one of the X direction and the Y direction. The fitting point is a position corresponding to the pupil position (eye point) of the wearer. This eye point is the line-of-sight position on the lens when the wearer is viewing horizontally.

  In the present embodiment, the lens Lc is a progressive power lens including a distance portion Lf and a near portion Ln. In the lens Lc, the upper end side during wearing from the optical center P is referred to as a distance portion Lf, and the lower end side during wearing from the optical center P is referred to as a near portion Ln. The vicinity of the boundary between the distance portion Lf and the near portion Ln is a progressive portion. The progressive power lens according to the present embodiment may be any of an outer surface progressive lens, an inner surface progressive lens, and a double-sided progressive lens.

  As shown in FIG. 1B, the lens Lb has an object-side surface Sf1 formed in a convex shape and an eyeball-side back surface Sf2 formed in a concave shape. The lens Lc has a similar shape. The lens Lb is a lens subjected to prism thinning. In FIG. 1B, a plane P1 (tangent plane) that passes through the optical center P and is perpendicular to an axis perpendicular to the surface Sf1 is inclined with respect to the XY plane. A plane P2 (tangent plane) that passes through the optical center P and is perpendicular to the axis perpendicular to the back surface Sf2 is parallel to the XY plane. Further, the plane P1 is inclined so as to move away from the plane P2 toward the -Y side. The lens Lb is a lens to which a refractive power (prism amount) in the YZ plane is added as compared with a lens not subjected to prism thinning. In the present embodiment, the prism amount can be selected in consideration of optical performance. For example, the prism amount can be optimized.

  FIG. 2 is a flowchart showing a lens design method and a lens manufacturing method according to this embodiment. The lens design method according to the present embodiment includes the processes shown in steps S1 to S8. In this embodiment, in order to manufacture a lens for spectacles, a lens is designed by the processing from step S1 to step S9), and the lens is processed according to this design (step S9).

  Next, a lens design method will be described. To design a lens, first, design conditions are set (step S1). In step S1, the prescription value of the wearer is acquired. The prescription value includes information selected from, for example, spherical power, distance power, near power, addition power, astigmatism power, lens material (refractive index), inset coordinates, and a prism for correcting strabismus. If there is lens specification information (hereinafter referred to as additional information), additional information is also acquired in step S1. Additional information includes, for example, product type (far-near, middle-near, near-term), fitting parameters (sledge angle, anteversion angle, corneal apex distance), spectacle frame shape (eg, ellipse, track shape), lens attachment to spectacle frame Methods (full support, upper end support, lower end support, two points), etc. Further, the additional information may include, for example, information designated by the wearer (hereinafter referred to as designation information). Additional information includes, for example, lens thickness (eg, center thickness, edge thickness, thickness at specified position, thickness balance), and design priority parameters (eg, optical performance, thinness, thickness balance) ) Etc. The additional information is obtained, for example, when the wearer checks a check sheet on a paper surface or a display screen.

  Next, in step S2, a plurality of candidate values for the prism amounts of the front and back surfaces of the progressive addition lens are set based on the prescription value of the wearer (condition setting process). In the present embodiment, a plurality of prism amount candidate values (prism amount patterns) are registered in a database as a table associated with a prescription value. In step S2, a plurality of candidate values for the prism amount are set by reading the prism amount pattern from the database.

  FIG. 3 is a conceptual diagram of a prism amount database used for condition setting processing. This database is divided by refractive index (Index) and includes a plurality of data sheets Ds having different additions (Add) for each refractive index. For example, when Index is 1.67 and Add is 0.75, the corresponding data sheet Ds is selected. The data sheet Ds has a plurality of data cells Dc divided by the spherical power (S) and the astigmatic power (C). For example, when S is 4.00 and C is 0.00, the corresponding data cell Dc is selected.

  In the data cell Dc, for example, ten types of prism amounts from pattern 1 to pattern 10 are registered. Plural types of prism amounts are selected according to parameter values such as prescription value of wearer, index, product type (far-near, middle-near, near-term), fitting parameters (warp angle, forward tilt angle, corneal apex distance), etc. Are registered in the data cell Dc.

  The prism amount is an amount that depends on the inclination between the front surface and the back surface of the progressive-power lens, and is represented by, for example, refractive power (Δdp). In FIG. 3, the prism amount of pattern 1 is 0.33Δdp. In the condition setting processing, a data cell corresponding to the prescription value is searched in such a database, and a plurality of prism amount candidate values are set by reading a plurality of prism amounts (pattern 1 to pattern 10) from the data cell. To do.

  The prism amount may be represented by a ratio (coefficient) to the addition (Add), or may be represented by an angle formed by the plane P1 and the plane P2 shown in FIG. In FIG. 3, the prism amount is stored in the data cell Dc divided by the index (Index), the addition power (Add), the spherical power (S), and the astigmatism power (C). You may store in the divided data cell.

  For example, as the outer diameter of the lens increases, the change in the edge thickness due to the prism amount increases. Therefore, the prism amount may be stored in a data cell divided by the outer diameter of the lens. The outer diameter of the lens may be the outer diameter of a processing-shaped lens, or may be the outer diameter of a lens processed into a shape that approximates a spectacle frame. When the lens shape is not a perfect circle, the outer diameter of the lens may be a dimension in the X direction or a dimension in the Y direction.

Next, in step S3 of FIG. 2, the shape of the progressive addition lens is determined using the prescription value for each of the plurality of candidate values of the prism amount (shape determination process). FIG. 4 is a flowchart illustrating an example of the shape determination process. In this example, the lens shape is changed according to the prism amount. In this shape determination process, in step S11, one of the plurality of prism amount candidate values (eg, pattern 1 in FIG. 3) is set. In step S12, the back surface shape is calculated. The back surface shape calculation is a design calculation for determining the shape of the back surface so that the target optical performance is obtained. In the back surface shape calculation, for example, the back surface shape is calculated so as to suppress aberrations or to give a designated frequency in accordance with the position of each part on the back surface. In the back surface shape calculation, examples of the input parameters include the surface shape, prescription, thickness, prism amount, warp angle, forward tilt angle, corneal apex distance, inset, and amount of prescription prism for correcting strabismus. The thickness is, for example, at least one of a center thickness, an edge thickness, and a thickness at a specified position. The back surface shape obtained by the back surface shape calculation is generally a free-form surface, and the entire surface changes depending on, for example, input parameters.
In step S13, a surface shape (initial surface shape) of a reference prism amount (eg, 0Δdp) is set. For example, a surface shape with a prism amount of 0 is arranged in a predetermined coordinate system. In step S14, the surface shape is changed from the initial surface shape so that the prism amount between the front surface and the back surface satisfies the prism amount set in step S11, and is inclined with respect to the back surface.

  In step S15, the lens thickness is adjusted by adjusting the distance between the front surface and the back surface (the position in the Z direction in FIG. 1B). For example, in step S15, the lens thickness is adjusted such that the maximum lens thickness (eg, center thickness) is minimized. In addition, when the thickness is designated by the wearer in the designation information or the like, the thickness is adjusted to be the same as or close to the designated thickness.

  Further, a lower limit value of the thickness at a predetermined position of the lens may be set, and the thickness of the lens may be adjusted to satisfy this condition. For example, as a lower limit value of the thickness, a thickness that can ensure the strength of the lens may be set in at least one of processing and wearing. For example, the thickness may be adjusted so that the edge thickness in the processing shape is thicker than 0.1 mm so as to avoid the knife edge in the processing shape (see the lens Lb in FIG. 1A). . In addition, the thickness may be adjusted so that processing for attachment to the spectacle frame can be performed in a state in which the shape is approximated to the spectacle frame (see the lens Lc in FIG. 1A).

  In the present embodiment, in step S16, it is determined whether the thickness adjustment amount is less than a threshold value. When the thickness adjustment amount is equal to or greater than the threshold (step S16; No), that is, when the thickness adjustment is excessive, the process returns to step S12 to change the back surface shape (curve). The case where the thickness adjustment is excessive is, for example, a case where the thickness of the lens is adjusted to be the thinnest in step S15, and as a result, the specified thickness or the thickness necessary for securing the strength is not satisfied. .

  In the present embodiment, the process from step S12 to step S16 is repeated until the thickness adjustment amount becomes less than the threshold value while changing the back surface shape. If the thickness adjustment amount is equal to or greater than the threshold (step S16; Yes), in step S17, shape information indicating the shape of the lens with respect to the prism amount set in step S11 is stored in a storage unit or the like. In this way, when the lens shape is determined while changing the back surface shape in accordance with the prism amount, it is possible to reduce a decrease in optical performance due to the prism amount. Note that the process of step S16 can be omitted, and the process of step S17 may be performed following the process of step S15.

  Then, in step S18, it is determined whether or not the calculation of the shape with respect to the prism amount of all patterns (eg, pattern 1 to pattern 10 in FIG. 3) has been completed. When the calculation of the shape with respect to the prism amounts of all patterns has not been completed (step S18; No), the process returns to step S11 to set the next prism amount (for example, pattern 2 in FIG. 3). Then, the processes from step S12 to step S18 are repeated until the calculation of the shapes for all patterns is completed. Then, when the calculation of the shape with respect to the prism amount of all patterns is completed (step S18; Yes), the shape determination process is ended.

  FIG. 5 is a flowchart illustrating another example of the shape determination process. In this example, the initial back surface shape is calculated without taking the prism amount into consideration. In step S21, a back surface shape (a distance portion curve and a near portion curve on the back surface) is calculated using the prescription value. In step S22, one of the prism amount candidate values (eg, pattern 1 in FIG. 3) is set. In step S23, an initial surface shape is set. In step S24, the initial surface shape is inclined with respect to the back surface so as to satisfy the prism amount set in step S22. In step S25, the lens thickness is adjusted by adjusting the distance between the front surface and the back surface. In step S26, it is determined whether the thickness adjustment amount is less than a threshold value. Note that the processing from step S23 to step S26 may be the same as the processing from step S13 to step S16 shown in FIG.

  When the thickness adjustment amount is equal to or greater than the threshold (step S26; No), the process returns to step S25 to change the back surface shape. In the present embodiment, the processing from step S25 to step S27 is repeated until the thickness adjustment amount becomes less than the threshold value while changing the back surface shape. If the thickness adjustment amount is greater than or equal to the threshold (step S26; Yes), in step S27, shape information indicating the shape of the lens with respect to the prism amount set in step S22 is stored in a storage unit or the like. As described above, when the initial back surface shape is determined without using the prism amount, iterative calculation can be reduced, and processing costs such as calculation time can be reduced.

  Then, in step S28, it is determined whether or not the calculation of the shapes with respect to the prism amounts of all patterns (eg, pattern 1 to pattern 10 in FIG. 3) has been completed. If the calculation of the shapes for the prism amounts of all patterns has not been completed (step S28; No), the process returns to step S22, and the next prism amount (for example, pattern 2 in FIG. 3) is set. Then, the processes from step S22 to step S28 are repeated until the calculation of the shapes for all patterns is completed. When the calculation of the shape with respect to the prism amount of all patterns is completed (step S29; Yes), the shape determination process is ended.

  After the shape determination process as described above is completed, in step S4 of FIG. 2, the optical performance information of the progressive power lens whose shape is determined by the shape determination process is calculated for each of the plurality of candidate values ( Performance calculation process). The optical performance information includes aberration distribution data and power distribution data of the progressive power lens.

  FIG. 6 is a diagram illustrating an example of optical performance information. FIG. 6A shows the aberration distribution data in a contour map, and FIG. 6B shows the frequency distribution data in a contour map. The aberration is, for example, small at the center in the X direction, and becomes larger toward the + X side or the −X side. In addition, the aberration is small in the distance portion (+ Y side) used in horizontal view and the like, and is large in the near portion (−Y side) used in downward view. Further, the frequency is small in the distance portion (+ Y side) and large in the near portion (−Y side). The aberration distribution data may be, for example, a data format in which coordinates and aberration values of each cell are paired with respect to a plurality of cells partitioned at an arbitrary pitch in each of the X direction and the Y direction. Similarly, the frequency distribution data may have a data format in which the coordinates and frequencies of each cell are combined.

  Such optical performance information is calculated by, for example, a ray tracing method. In the performance calculation process, it is only necessary to calculate the optical performance information for the region used at the time of wearing, and the optical performance information for a part of the range of the lens blank La shown in FIG. Need not be calculated. For example, in the performance calculation process, optical performance information is selectively calculated for a part of the progressive power lens including a region (for example, the lens Lc in FIG. 1A) attached to the spectacle frame. May be. For example, in the performance calculation process, the optical performance information may be calculated in a region within the lens Lc in FIG. 1A, and the optical performance information may not be calculated in at least a partial region outside the lens Lc.

  Next, in step S5 of FIG. 2, a performance index value indicating a difference in optical performance information due to a difference in prism amount among a plurality of candidate values is calculated (performance index calculation process). In the performance index calculation process, the performance index value related to aberration is calculated by comparing the aberration distribution data calculated in step S4 with the aberration distribution data for evaluation. The aberration distribution data for evaluation is calculated in advance according to the prescription and stored in the database. The aberration distribution data for evaluation is, for example, data indicating the aberration distribution optimized for realizing the optical performance specified in the prescription. The aberration distribution data for evaluation may be, for example, aberration distribution data in a progressive power lens in which the prism amount is set to a reference value (eg, 0Δdp). In this embodiment, the difference between the aberration distribution data for evaluation and the aberration distribution data obtained by the performance calculation process is calculated, and the performance index value related to the aberration is calculated by weighting the difference value. The weighting coefficient used for weighting the aberration difference is determined according to the position on the progressive addition lens.

  In the performance index calculation process, the performance index value related to the frequency is calculated by comparing the frequency distribution data calculated in step S4 with the frequency distribution data for evaluation. The frequency distribution data for evaluation is calculated in advance according to the prescription and stored in the database. The frequency distribution data for evaluation is data indicating a frequency distribution optimized for realizing the optical performance specified in the prescription, for example. The frequency distribution data for evaluation may be, for example, frequency distribution data in a progressive power lens in which the prism amount is set to a reference value (eg, 0Δdp). In the present embodiment, the performance index value related to the frequency is calculated by calculating the difference between the frequency distribution data for evaluation and the frequency distribution data obtained by the performance calculation process and weighting the difference value. The weighting coefficient used for weighting the frequency difference is determined according to the position on the progressive addition lens.

  The aberration distribution data for evaluation, the frequency distribution data for evaluation, and the weighting coefficient distribution data for evaluation as described above are stored in the database in association with the prescription value. The weight coefficient distribution data is represented by, for example, a set of coordinates of a cell partitioned on the progressive addition lens and a weight coefficient in this cell.

  FIG. 7 is a conceptual diagram showing an evaluation database used for performance index calculation processing. This database is partitioned by refractive index (Index) and inset coordinates (Y coordinates). In the evaluation database, a plurality of data sheets Ds having different additions (Add) are stored for each set of the refractive index (Index) and the inset coordinates (Y coordinate). For example, for example, when Index is 1.67, inset coordinates are Y = 11 mm, and Add is 0.75, the corresponding data sheet Ds is selected.

  The data sheet Ds has a plurality of data cells Dc divided by the spherical power (S) and the astigmatic power (C). For example, when S is 4.00 and C is 0.00, the corresponding data cell Dc is selected. The data cell Dc stores evaluation aberration distribution data, evaluation frequency distribution data, and evaluation weight coefficient distribution data as evaluation data used in the performance index calculation processing.

  FIG. 8 is a conceptual diagram showing evaluation data used in the performance index calculation process. The aberration distribution data for evaluation is represented by a set of coordinates of a cell partitioned on the progressive addition lens and a weighting coefficient in this cell. For example, in the cell with X = Xi and Y = Yj, the aberration for evaluation is expressed as 2.0 dp. The evaluation frequency distribution data is represented by a set of the coordinates of the cell and the frequency in the cell. For example, in the cell of X = Xi and Y = Yj, the evaluation frequency is expressed as 1.0 dp. The evaluation weight coefficient distribution data is represented by a set of a cell coordinate, an aberration weight coefficient in this cell, and a frequency weight coefficient in this cell. For example, in the cell where X = Xi and Y = Yj, the aberration weighting coefficient is 0.8 and the power weighting coefficient is 1.0 dp. These weighting factors are for example: It is set as a larger value as the position is assumed to be used more frequently during wearing.

  In the performance index calculation process, the difference (absolute value of the difference) between the aberration in the aberration distribution data for evaluation and the aberration in the aberration distribution data calculated in the performance calculation process at each position (each cell) on the progressive addition lens. Is calculated. Then, a first multiplication value is calculated by multiplying the aberration difference value by the aberration weighting coefficient at each position on the progressive addition lens. For example, when X = Xi and Y = Yi, the evaluation aberration is 2.0 dp and the aberration weighting factor is 0.8. Therefore, when the aberration calculated in the performance calculation process is 2.1, The first multiplication value is calculated as 0.08 by (2.1−2.0) × 0.8. Then, the first integrated value is calculated by integrating the first multiplied value at each position on the progressive addition lens. The first integrated value indicates, for example, that the larger the value is, the lower the optical performance is for evaluation (eg, the amount of prism is 0). Thus, the first integrated value is a performance index value related to aberration.

  In the performance index calculation process, the difference between the frequency of the frequency distribution data for evaluation and the frequency of the frequency distribution data calculated by the performance calculation process (absolute difference) at each position (each cell) on the progressive addition lens. Value). Then, a second multiplication value is calculated by multiplying the power difference by the power weight coefficient at each position on the progressive addition lens. For example, when X = Xi and Y = Yi, the evaluation frequency is 1.0 dp and the aberration weighting factor is 1.0. Therefore, when the frequency calculated in the performance calculation process is 1.2, The second multiplication value is calculated as 0.2 by (1.2−1.0) × 1.0. Then, the second integrated value is calculated by integrating the second multiplied value at each position on the progressive addition lens. For example, the second integrated value indicates that the larger the value is, the lower the optical performance is for evaluation (eg, the amount of prism is 0). Thus, the second integrated value is a performance index value related to frequency.

  FIG. 9 is a conceptual diagram showing the performance index calculation process. In the present embodiment, a value obtained by adding the first integrated value (performance index value related to aberration) and the second integrated value (performance index value related to frequency) as described above is used as the performance index value (“optical performance” in FIG. 9). It is calculated as “evaluation”. This performance index value is an index value indicating that the larger the value, the lower the optical performance. In the present embodiment, a performance index value is calculated for each of a plurality of candidate values of the prism amount, and an evaluation score corresponding to the rank when the performance index values are arranged in ascending order is assigned to the plurality of candidate values. For example, in FIG. 9, the value with the smallest evaluation of optical performance (the optical performance is good) is pattern 2, and the evaluation of optical performance increases in the order of pattern 4, pattern 1, and pattern 3. Therefore, the evaluation score of pattern 4 is set to 10, and the lower evaluation score is given to the pattern with the lower rank.

  In the performance index calculation process, optical performance information may be calculated for the area used during wearing, and the performance index for a part of the range of the lens blank La shown in FIG. It is not necessary to calculate a value or an evaluation score. For example, in the performance index calculation processing, the performance index value is selectively selected for a part of the progressive power lens including a region (for example, the lens Lc in FIG. 1A) attached to the spectacle frame. It may be calculated. For example, in the performance calculation process, the performance index value may be calculated in the area within the lens Lc in FIG. 1A, and the performance index value may not be calculated in at least a part of the area outside the lens Lc.

  Note that the evaluation score may not be a value corresponding to the ranking, may be calculated as a value corresponding to the performance index value, or may be the performance index value itself. Evaluation points are stored in the database as values related to parameters such as prescription value, index, product type (far-near, middle-near, near-term) of the wearer, and fitting parameters (sledge angle, anteversion angle, corneal apex distance). May be. Such parameters include, for example, inset Y coordinate values, outer diameters, etc., and may be values according to the lens shape. Moreover, the evaluation score may be set for each evaluation of an arbitrary item (eg, aberration, power).

  In the present embodiment, in step S6 of FIG. 2, a thickness index value indicating a difference in thickness depending on the prism amount is calculated (thickness index calculation process). The thickness index value is calculated based on, for example, at least one of the center thickness, the specified thickness, and the thickness balance.

  FIG. 10 is a conceptual diagram showing a thickness index calculation process using the center thickness. In the thickness index calculation process, the center thickness is calculated for the progressive-power lens whose shape is determined for each prism amount in the shape determination process. The center thickness is one of thickness index values. Then, an evaluation score corresponding to the ranking when the center thicknesses are arranged in ascending order is given to the plurality of candidate values of the prism amount. For example, in FIG. 10, the center thickness is the thinnest in pattern 1, and the center thickness increases in the order of pattern 2, pattern 3, and pattern 4. Therefore, the evaluation score of pattern 1 is set to 10, and the lower evaluation score is given to the pattern with the lower rank.

  FIG. 11 is a conceptual diagram showing a thickness index calculation process using a specified thickness. In the thickness index calculation process, the thickness at the specified position is calculated for the progressive-power lens whose shape is determined for each prism amount in the shape determination process, and the calculated thickness and the specified thickness (specified The difference from (thickness) is calculated. The difference from the specified thickness is one of the thickness index values. Then, an evaluation score corresponding to the order when the plurality of candidate values of the prism amount are arranged in ascending order of the difference from the specified thickness is given. For example, in FIG. 11, the difference from the specified thickness is the smallest in pattern 2 and pattern 4, and the difference from the specified thickness increases in the order of pattern 1 and pattern 3 below. Therefore, the evaluation score of the pattern 2 and the pattern 4 is set to 10, and the lower evaluation score is given to the pattern with the lower rank.

  FIG. 12 is a conceptual diagram showing a thickness index calculation process using a thickness balance. In the thickness index calculation process, the difference between the upper edge thickness and the lower edge thickness (difference in upper and lower thicknesses) is calculated for the progressive-power lens whose shape has been determined for each prism amount in the shape determination process. . The difference between the upper and lower thicknesses is one of the thickness index values. Then, an evaluation score corresponding to the rank when the plurality of candidate values of the prism amount are arranged in ascending order of thickness difference is given. For example, in FIG. 12, the difference between the upper and lower thicknesses is the smallest in pattern 2, and the difference in the upper and lower thicknesses increases in the order of pattern 4, pattern 1, and pattern 3. Therefore, the evaluation score of pattern 2 is set to 10, and the lower evaluation score is given to the pattern with the lower rank.

  In the thickness index calculation process, the thickness index value may be calculated for the region used at the time of wearing, and the thickness index for a part of the range of the lens blank La shown in FIG. It is not necessary to calculate the value. For example, in the thickness index calculation process, the thickness index value is selectively applied to a part of the progressive power lens including a region (for example, the lens Lc in FIG. 1A) attached to the spectacle frame. It may be calculated. For example, in the performance calculation process, the thickness index value may be calculated in a region within the lens Lc in FIG. 1A, and the thickness index value may not be calculated in at least a part of the region outside the lens Lc.

  In the thickness index calculation process, the evaluation points are related to parameters such as the prescription value of the wearer, the index, the product type (perspective, middle, near), and fitting parameters (warp angle, forward tilt angle, corneal apex distance). It may be stored in the database as a value. This parameter includes, for example, the inset Y coordinate value, the outer diameter, and the like, and may be stored in the database as a value according to the lens shape. The evaluation point may not be a value corresponding to the rank, may be calculated as a value corresponding to the thickness index value, or may be the thickness index value itself.

  In this embodiment, in step S7 of FIG. 2, the evaluation value of the progressive addition lens is calculated (evaluation process). In the evaluation process, the performance index value (or evaluation point) is multiplied by a weighting coefficient, and the multiplied value is used as an evaluation value related to optical performance. In the evaluation process, the thickness index value (or evaluation point) is multiplied by a weighting coefficient, and the multiplied value is used as an evaluation value related to thickness. Further, the evaluation value of the progressive power lens is calculated by adding the evaluation value related to the optical performance and the evaluation value related to the thickness. The weighting factor used in the evaluation process is stored in the database in association with the prescription value, for example.

  FIG. 13 is a conceptual diagram showing an evaluation database used in the evaluation process. This database is divided by refractive index (Index) and includes a plurality of data sheets Ds having different additions (Add) for each refractive index. For example, when Index is 1.67 and Add is 0.75, the corresponding data sheet Ds is selected. The data sheet Ds has a plurality of data cells Dc divided by the spherical power (S) and the astigmatic power (C). For example, when S is 4.00 and C is 0.00, the corresponding data cell Dc is selected. The data cell Dc stores an optical performance evaluation weight coefficient, a thinnest evaluation weight coefficient, a designated thickness evaluation weight coefficient, and a thickness balance weight coefficient.

  FIG. 14 is a conceptual diagram showing the evaluation process. In the evaluation process, a weighted optical performance evaluation point is calculated by calculating an optical performance evaluation point (see FIG. 9) and an optical performance evaluation weight coefficient for each prism amount (prism amount pattern). For example, when the optical performance evaluation point of pattern 1 is 8 and the optical performance evaluation weighting factor is 1.0, the weighted optical performance evaluation point is 8 × 1.0 = 8.

  In the evaluation process, a weighted center thickness evaluation point is calculated by calculating a center thickness evaluation point (see FIG. 10) and a thinnest evaluation weight coefficient for each prism amount (prism amount pattern). For example, if the center thickness evaluation point of pattern 1 is 10 and the center thickness evaluation weight coefficient is 0.9, the weighted center thickness evaluation point is 10 × 0.9 = 9.

  In the evaluation process, a weighted designated thickness evaluation point is calculated by calculating a designated thickness evaluation point (see FIG. 11) and a designated thickness evaluation weight coefficient for each prism amount (prism amount pattern). For example, when the designated thickness evaluation point of pattern 1 is 8 and the designated thickness evaluation weight coefficient is 1.1, the weighted designated thickness evaluation point is 8 × 1.1 = 8.8.

  In the evaluation process, a weighted thickness balance evaluation point is calculated by calculating an evaluation point (see FIG. 12) of a difference between upper and lower thicknesses for each prism amount (prism amount pattern) and a thickness balance evaluation weight coefficient. For example, when the thickness balance evaluation point of pattern 1 is 8 and the thickness balance evaluation weight coefficient is 0.8, the weighted thickness balance evaluation point is 8 × 0.8 = 6.4.

  In the evaluation process, a total evaluation point is calculated by taking a total of various weighted evaluation points for each prism amount (prism amount pattern). In FIG. 14, the total evaluation score of pattern 2 is the highest, and the total evaluation score is lower in the order of pattern 1, pattern 4, and pattern 3 below. In this manner, for example, the prism amount in the pattern 2 can be selected as a recommended value for the prescription value, for example.

  In the present embodiment, for example, as shown in FIG. 14, the total evaluation score is calculated for the right-eye lens, and the total evaluation score is calculated for the left-eye lens in the same manner. In the evaluation process, evaluation may be performed using the total evaluation point of the right-eye lens and the total evaluation point of the left-eye lens.

  FIG. 15 is a conceptual diagram illustrating another example of the evaluation process. In this evaluation process, the total evaluation score of the right-eye lens and the total evaluation score of the left-eye lens are summed to calculate a left-right total evaluation score. In the example of FIG. 15, the left and right total evaluation points are the same value in pattern 2 and pattern 3. In such a case, for example, the recommended value of the prism amount can be determined in consideration of the dominant eye. For example, the evaluation score of the lens for the left eye is larger in pattern 2 than in pattern 3. Therefore, the pattern 2 can be a recommended value for a wearer whose left eye is dominant. In addition, the prism amount with the smaller difference between the evaluation point of the left-eye lens and the evaluation point of the right-eye lens can be set as the recommended value. Further, the total left and right evaluation points may be calculated by weighting the total evaluation point of the right eye lens and the total evaluation point of the left eye lens according to, for example, the dominant eye.

  Next, the lens design system according to the present embodiment will be described. FIG. 16 is a diagram illustrating a lens supply system SYS to which the lens design system 1 according to the present embodiment is applied. The lens supply system SYS includes a lens design system 1, a design condition supply system 2, and a processing system 3.

  The design condition supply system 2 is installed, for example, in a spectacle store, but may be installed in a wearer's home or the like. The design condition supply system 2 includes an information processing device 5, a display device 6, and an input device 7. The information processing apparatus 5 is a computer system, for example, and is connected to the lens design system 1 via a line 10 such as the Internet.

  The input device 7 is, for example, a keyboard, a mouse, a touch panel, and the like, and is connected to the information processing device 5. The input device 7 can accept input of information used for lens design such as prescription values. The information processing device 5 can acquire information input to the input device 7 and supply this information to the lens design system 1 via the line 10. For example, a wearer or an eyeglass dealer can supply prescription values, additional information, designation information, and the like to the lens design system 1 by operating the input device 7.

  The display device 6 is a liquid crystal display, for example, and is connected to the information processing device 5. The display device 6 can display, for example, information input to the information processing device 5 via the input device 7, information on lenses designed by the lens design system 1, and the like.

  The lens design system 1 is installed in a design facility in a lens manufacturer, for example. The lens design system 1 includes an information processing device 11 and a database DB. For example, the information processing apparatus 11 receives a prescription value or the like from the design condition supply system 2 and designs a progressive-power lens. The database DB stores various data used for lens design. The information processing apparatus 11 designs a lens using the information read from the database DB and the prescription value supplied from the design condition supply system 2.

  The information processing apparatus 11 includes a condition setting unit 12, a shape determination unit 13, a performance calculation unit 14, a performance index calculation unit 15, a thickness index calculation unit 16, and an evaluation unit 17. The condition setting unit 12 sets a plurality of candidate values for the prism amounts of the first surface on the object side and the second surface on the eyeball side of the progressive-power lens based on the prescription value of the wearer. The condition setting unit 12 performs the condition setting process described with reference to FIG. The shape determination unit 13 determines the shape of the progressive-power lens using the prescription value for each of the plurality of candidate values of the prism amount. The shape determining unit 13 performs the shape determining process described with reference to FIG.

  The performance calculation unit 14 calculates optical performance information of the progressive-power lens whose shape is determined by the shape determination unit 13 for each of the plurality of candidate values of the prism amount. The performance calculation unit 14 performs the shape determination process described with reference to FIG. The performance index calculation unit 15 calculates a performance index value indicating a change in optical performance information depending on the prism amount. The performance index calculation unit 15 performs the performance index calculation process described with reference to FIG. The thickness index calculation unit 16 calculates a thickness index value indicating a difference in thickness depending on the prism amount of the progressive-power lens determined by the shape determination unit 13 for each of the plurality of prism amount candidate values. For example, the thickness index calculation unit 16 performs the thickness index calculation processing described in FIG. The evaluation unit 17 calculates an evaluation value of the progressive-power lens using a multiplication value obtained by multiplying the performance index value by the weighting factor and a multiplication value obtained by multiplying the thickness index value by the weighting factor. The evaluation unit 17 performs the evaluation process described with reference to FIG.

  The lens design system 1 can supply the design condition supply system 2 with information indicating the lens shape of at least one progressive power lens designed according to the prism amount, for example. The information processing device 5 of the design condition supply system 2 can display an image showing the lens shape supplied from the lens design system 1 on the display device 6.

  For example, the lens design system 1 supplies information on the lens shape of the prism amount having the highest evaluation score to the design condition supply system 2, and the design condition supply system 2 displays the lens shape image on the display device 6. Also good. In this case, the wearer can, for example, confirm the design result and confirm the order.

  Further, the lens design system 1 may supply information on a plurality of lens shapes having different prism amounts to the design condition supply system 2, and the design condition supply system 2 may display these lens shape images on the display device 6. . In this case, the wearer can arbitrarily select a lens shape from a plurality of lens shapes. The lens design system 1 may not supply the design result to the design condition supply system 2.

  The lens processing system 3 includes a processing device 20 that processes a lens, and a control device 21 that controls the processing device 20. The lens processing system 3 is connected to the lens design system 1 via a line 22 such as the Internet. The lens design system 1 supplies information used for lens processing to the control device 21 of the lens processing system 3 as information (design result) regarding the shape of the progressive-power lens ordered from a spectacles seller or a wearer, for example. To do. The control device 21 controls the processing device 20 according to the information supplied from the lens design system 1 to process the lens.

  In the lens design system 1 as described above, the information processing apparatus 11 includes a computer having a CPU and a memory. In the information processing apparatus 11, the computer executes various processes according to the lens design program. This program is a condition setting process for setting a plurality of candidate values for the prism amounts of the first surface on the object side and the second surface on the eyeball side of the progressive-power lens based on the prescription value of the wearer. Then, for each of the plurality of candidate values, the shape is determined by the shape determination process for determining the shape of the progressive addition lens using the prescription value, and for each of the plurality of candidate values, the shape is determined by the shape determination process. A performance calculation process for calculating the optical performance information of the progressive-power lens and a performance index calculation process for calculating a performance index value indicating a change in the optical performance information depending on the prism amount are executed. This program may be provided by being stored in a computer-readable storage medium such as an optical disc, a CD-ROM, a USB memory, or an SD card.

  The lens design system 1 may perform shape determination processing for each of a plurality of candidate values of the prism amount by parallel calculation or the like. For example, the lens design system 1 may cause each of a plurality of nodes in the computer array to execute a shape determination process for one prism amount and perform an evaluation process by a host computer.

  The lens design system 1 may be a part of the design condition supply system 2, may be a part of the processing system 3, or may be applied to a system other than the lens supply system SYS. For example, the lens design system 1 may be installed in a spectacle store. In this case, for example, the calculation load can be reduced by adopting the shape determination process shown in FIG. In the lens design system 1, the types of prism amount candidate values may be set according to the processing capability of the information processing apparatus 11.

  The technical scope of the present invention is not limited to the above embodiment. For example, one or more of the requirements described in the above embodiments may be omitted. The requirements described in the above embodiments can be combined as appropriate.

DESCRIPTION OF SYMBOLS 1 ... Lens design system, 12 ... Condition setting part, 13 ... Shape determination part,
14 ... Performance calculation unit, 15 ... Performance index calculation unit, 16 ... Index calculation unit,
17 ... Evaluation part, DB ... Database

Claims (20)

Based on the prescription value of the wearer, a condition setting process for setting a plurality of candidate values for the prism amounts of the first surface on the object side and the second surface on the eyeball side of the progressive-power lens;
For each of the plurality of candidate values, a shape determination process that determines the shape of the progressive-power lens using the prescription value;
Performance calculation processing for calculating optical performance information of the progressive-power lens whose shape has been determined by the shape determination processing for each of the plurality of candidate values;
A performance index calculation process for calculating a performance index value indicating a change in the optical performance information according to the prism amount.   The lens design method according to claim 1, wherein the condition setting process includes acquiring data associating the prescription value and the plurality of candidate values from a database. The shape determination process includes
Determining the respective shapes of the first surface and the second surface based on the prescription value;
Setting an inclination between the first surface and the second surface based on the candidate value of the prism amount;
The lens design method according to claim 1, further comprising: adjusting an interval between the first surface and the second surface on which the inclination is set.   The shape determination processing includes changing at least one of the shape of the first surface and the shape of the second surface based on the adjusted distance between the first surface and the second surface. The lens design method according to claim 3.   The said performance calculation process includes calculating the said optical performance information selectively with respect to the one part area | region including the area | region attached to a spectacles frame among the said progressive power lenses. The lens design method according to any one of the above.   The performance calculation process includes calculating aberration distribution data and frequency distribution data of the progressive-power lens determined by the shape determination process as the optical performance information. The lens design method according to one item.   The performance index calculation process acquires evaluation aberration distribution data calculated in advance according to the prescription from a database, and compares the aberration distribution data calculated by the performance calculation process with the evaluation aberration distribution data. The lens design method according to claim 6, further comprising: The performance index calculation process includes:
Calculating a first multiplication value obtained by multiplying a difference value between the aberration distribution data acquired from the database and the aberration distribution data calculated by the performance calculation process by a weighting coefficient at each point on the progressive-power lens;
Calculating a first integrated value obtained by integrating the first multiplied value on the progressive-power lens;
The lens design method according to claim 7, comprising calculating the performance index value using the first integrated value.   The performance index calculation processing acquires frequency distribution data for evaluation calculated in advance according to the prescription from a database, and compares the frequency distribution data calculated by the performance calculation processing with the frequency distribution data for evaluation The lens design method according to any one of claims 6 to 8, further comprising: The performance index calculation process includes:
Calculating a second multiplication value obtained by multiplying a difference value between the frequency distribution data acquired from the database and the frequency distribution data calculated by the performance calculation process by a weighting coefficient at each point on the progressive-power lens;
Calculating a second integrated value obtained by integrating the second multiplied value on the progressive-power lens;
The lens design method according to claim 9, comprising calculating the performance index value using the second integrated value.   The said performance index calculation process includes calculating the said performance index value selectively with respect to the one part area | region including the area | region attached to a spectacles frame among the said progressive-power lenses. The lens design method according to claim 10.   From the thickness index calculation processing which calculates the thickness index value which shows the difference in the thickness by the prism amount of the progressive-power lens determined by the shape determination processing for each of the plurality of candidate values The lens design method according to claim 11.   The thickness index calculation process includes calculating the thickness index value using a center thickness of the progressive-power lens determined by the shape determination process for each of the plurality of candidate values. The lens design method described in 1.   The thickness index calculation process calculates the thickness index value using a difference between an upper end thickness and a lower end thickness of the progressive-power lens determined by the shape determination process for each of the plurality of candidate values. The lens design method according to claim 12 or 13, comprising:   The thickness index calculation process calculates the thickness index value using a thickness and a target value at a designated position of the progressive-power lens determined by the shape determination process for each of the plurality of candidate values. The lens design method according to any one of claims 12 to 14, comprising:   The thickness index calculation process includes calculating the thickness index value selectively with respect to a processing region including a region where an alloy is attached during processing in the progressive-power lens. Item 16. The lens design method according to any one of Items 15 to 15.   An evaluation process for calculating an evaluation value of the progressive-power lens using a multiplication value obtained by multiplying the performance index value by a weighting factor and a multiplication value obtained by multiplying the thickness index value by a weighting factor. The lens design method according to claim 16. Designing a progressive-power lens by the lens design method according to any one of claims 1 to 17,
Manufacturing a progressive power lens according to the design. On the computer,
Based on the prescription value of the wearer, a condition setting process for setting a plurality of candidate values for the prism amounts of the first surface on the object side and the second surface on the eyeball side of the progressive-power lens;
For each of the plurality of candidate values, a shape determination process that determines the shape of the progressive-power lens using the prescription value;
Performance calculation processing for calculating optical performance information of the progressive-power lens whose shape has been determined by the shape determination processing for each of the plurality of candidate values;
A lens design program for executing a performance index calculation process for calculating a performance index value indicating a change in the optical performance information according to the prism amount. Based on the prescription value of the wearer, a condition setting unit that sets a plurality of candidate values for the prism amounts of the first surface on the object side and the second surface on the eyeball side of the progressive-power lens;
For each of the plurality of candidate values, a shape determining unit that determines the shape of the progressive-power lens using the prescription value;
For each of the plurality of candidate values, a performance calculator that calculates optical performance information of the progressive-power lens whose shape has been determined by the shape determiner;
A performance index calculation unit that calculates a performance index value indicating a change in the optical performance information according to the prism amount.

Images