JP5061331B2 - Method for designing and manufacturing progressive-power lens - Google Patents

Description

  The present invention relates to a designing method and a manufacturing method of a progressive power lens having a progressive surface shape having a progressive characteristic suitable for an arbitrary frame shape.

The progressive characteristics of progressive-power lenses can be broadly categorized. The distance type (with a wide distance area above the lens), the middle and near type with a narrower distance area, and the near area with a larger distance area are sacrificed. There is a type soon. These three types of characteristics are very different from each other, and the user selects a suitable type of product according to the purpose.
Apart from the selection focusing on the progressive characteristics of the progressive power lens, the progressive characteristics may be limited by the frame selected by the user. For example, a lens with a long progressive zone is not suitable for a frame with a small vertical width, and it is better to select a lens with a short progressive zone so that the near-field region of the lens fits in the frame. That is, when the user arbitrarily selects a frame, it is necessary to employ a progressive power lens having a progressive characteristic suitable for the frame shape.
When a lens having a progressive characteristic suitable for a certain frame is applied, it is also conceivable to design a progressive-power lens having a characteristic suitable for a custom by performing a progressive design for each frame. For example, Patent Document 1 gives such an example.
JP 2007-241276 A

However, the method of manufacturing a progressive-power lens according to the invention of Patent Document 1 is to sequentially calculate the power necessary for the lens by an iterative method in order to obtain a target power defect and a target astigmatism defect in each viewing direction. Assured that the calculation method is very complicated, requires a lot of time or labor to calculate, and that even if it takes such a trouble, a progressive power lens suitable for many orders can be manufactured accurately Nor. In addition, in actuality, designing a progressive-power lens having such custom-made characteristics is troublesome in terms of cost because it takes a lot of time or labor to calculate. For this reason, usually, a technique of combining a frame suitable for the frame from a progressive characteristic pattern of a progressive addition lens having a predetermined progressive characteristic prepared in advance is often employed.
However, it is difficult to select a progressive-power lens having progressive characteristics suitable for the frame shape without subjectivity, and if there are too many progressive-characteristic patterns, a number of options can be made and cannot be determined.
The present invention has been made paying attention to such problems existing in the prior art. The object is to provide a method for designing or manufacturing a progressive-power lens having progressive characteristics suitable for an arbitrary frame by an objective and appropriate method.

In order to solve the above-mentioned problems, the invention of claim 1 is a method for designing a progressive power lens having a progressive surface shape having a progressive characteristic suitable for an arbitrary frame shape P, and includes the following steps. Is the gist.
(A) A first data calculation step of designing a suitable reference progressive surface shape for a predetermined frame shape whose shape is specified, and calculating the reference progressive surface shape as first data.
(B) A scale setting step for determining one or more quantitative scales as an index for determining the evaluation value of the frame.
(C) Obtain shape data for each of a plurality of known frame shapes to be analyzed, analyze the difference in shape from other frame shapes for each frame shape based on the same shape data, and for each frame shape An evaluation value determination step for determining an evaluation value relative to another frame shape.
(D) Representative by adding a scale amount corresponding to an evaluation value of a typical frame shape for each scale from each frame shape to which an evaluation value is given in the evaluation value determination step. A representative frame determining step for determining a frame shape (hereinafter referred to as a representative frame shape);
(E) A suitable progressive surface shape for each representative frame shape determined in the representative frame determination step is designed by adding a sag amount to the first data obtained in the first data calculation step. A second data calculation step of calculating second data corresponding to the sag amount.
(F) Based on the evaluation value, a weight is set for the shape data of the arbitrary frame shape P for each scale, and the second data of the representative frame shape given the weight for each scale is used as a correction value. A synthesis step of synthesizing the first data and processing based on the synthesized data to obtain a progressive surface shape of the arbitrary frame shape P.

Further, the invention of claim 2 is a method of manufacturing a progressive power lens having a progressive surface shape having a progressive characteristic suitable for an arbitrary frame shape P, and comprises the following steps: To do.
(A) A first data calculation step of designing a suitable reference progressive surface shape for a predetermined frame shape whose shape is specified, and calculating the reference progressive surface shape as first data.
(B) A scale setting step for determining one or more quantitative scales as an index for determining the evaluation value of the frame.
(C) Obtain shape data for each of a plurality of known frame shapes to be analyzed, analyze the difference in shape from other frame shapes for each frame shape based on the same shape data, and for each frame shape An evaluation value determination step for determining an evaluation value relative to another frame shape.
(D) Representative by adding a scale amount corresponding to an evaluation value of a typical frame shape for each scale from each frame shape to which an evaluation value is given in the evaluation value determination step. A representative frame determining step for determining a frame shape (hereinafter referred to as a representative frame shape);
(E) A suitable progressive surface shape for each representative frame shape determined in the representative frame determination step is designed by adding a sag amount to the first data obtained in the first data calculation step. A second data calculation step of calculating second data corresponding to the sag amount.
(F) Based on the evaluation value, a weight is set for the shape data of the arbitrary frame shape P for each scale, and the second data of the representative frame shape given the weight for each scale is used as a correction value. A lens creating step of combining the first data and processing a predetermined lens precursor based on the combined data to obtain a lens having a progressive surface shape having the same frame shape P.

Further, in the invention of claim 3, in addition to the configuration of the invention of claim 2, the gist that the predetermined frame shape having the specified shape is an average frame shape based on the plurality of frame shapes. And
In addition, in the invention of claim 4, in addition to the configuration of the invention of claim 2 or 3, a covariance matrix or a correlation matrix is used for evaluating the difference from other frame shapes for each frame shape in the evaluation value determining step. The gist is to calculate the eigenvector of the determinant, determine the principal component corresponding to the eigenvector, and use the principal component score for each frame shape as the evaluation value.
In addition to the configuration of the invention according to any one of claims 2 to 4, the gist of the invention of claim 5 is that the shape data of the frame shape is three-dimensional data in which a spatial position is specified.
Further, in the invention of claim 6, in addition to the configuration of the invention of any one of claims 2 to 5, the representative frame shape is the one having the highest evaluation value among the plurality of frame shapes in each scale. The gist is that it is low.

In the invention of claim 7, in addition to the configuration of the invention of any one of claims 2 to 6, the preferred progressive surface shape of the plurality of representative frame shapes determined for each scale has the same base curve. The gist of that is.
Further, in the invention of claim 8, in addition to the configuration of the invention of any of claims 2 to 6, the preferred progressive surface shapes of the plurality of representative frame shapes determined for each scale are not the same in base curve. This is the gist.
In the invention of claim 9, in addition to the configuration of the invention of any one of claims 2 to 8, a preferred progressive surface shape of the plurality of representative frame shapes determined for each scale has a progressive zone length. The gist is that it is constant.
Further, in the invention of claim 10, in addition to the configuration of the invention of any of claims 2 to 8, a preferred progressive surface shape of the plurality of representative frame shapes determined for each scale has a progressive zone length. The gist is that it is not constant.
Further, in the invention of claim 11, in addition to the structure of the invention of any one of claims 2 to 10, a preferred progressive surface shape of the plurality of representative frame shapes determined for each of the scales is distance surface refraction. The gist is that the force and the near surface refractive power are the same.
Further, in the invention of claim 12, in addition to the structure of the invention of any one of claims 2 to 10, a preferred progressive surface shape of the plurality of representative frame shapes determined for each scale is a distance surface refractive power. Alternatively, the gist of the invention is that the near surface refractive powers do not have to be the same.

In the above configuration, a suitable progressive surface shape is designed for a predetermined frame shape whose shape is specified in the first data calculation step, and the progressive surface shape is calculated as the first data. However, since the first data is required for the calculation in the later-described synthesis step (lens creation step), it may be calculated before the synthesis step (lens creation step). The shape is theoretically not limited as long as it is a predetermined frame shape whose shape is specified, but it is preferably an average frame shape based on a plurality of frame shapes described later for ease of calculation. Here, the “frame shape” corresponds to the shape of a so-called target lens obtained by cutting a lens (so-called round lens) prescribed according to the visual acuity of the customer in accordance with the frame. In the target lens shape, the position of the user's eye point has already been determined as a part of the prescription. Therefore, in the present invention, the frame shape means a shape that also considers the eye point position.
In the scale setting step, one or more quantitative scales are set as an index for determining the evaluation value of the frame. Basically, any number of scales can be used.
Here, the scale is a standard for evaluating the state of the frame shape such as a difference in the vertical or horizontal width of the frame, or a square shape, an oval shape, or an area difference. In addition, the scale is not necessarily a scale from a two-dimensional viewpoint, but can be a scale reflecting information on the distance between the apex, the forward tilt angle, and the sled angle.

Next, shape data is obtained for each of a plurality of frame shapes whose shapes are already known in the evaluation value determination step. Then, a scale amount corresponding to an evaluation value of a typical frame shape is added to the predetermined frame shape for each scale from the shape data. The scale amount may be paraphrased as a unique vector amount corresponding to the scale.
The frame shape may be not only two-dimensional shape data but also three-dimensional data in which a spatial position is specified. In the case of three-dimensional data, it is possible to reflect the distance between the apex, the forward tilt angle and the warp angle of the frame as described above. The scale may be set with the provision of the evaluation value in the evaluation value determination step without being set in advance.
Since the evaluation varies depending on the scale, the evaluation value of the frame shape is not the same for each scale. The evaluation method may be subjective, but if more objectivity is given, for example, a covariance matrix or correlation matrix is derived, the eigenvector of the determinant is calculated, the principal component corresponding to the eigenvector is determined, and each frame is determined. The main component score for each shape is preferably used as the scale amount. The principal component can be obtained by using the principal component analysis, which can be regarded as a kind of scale. Since a plurality of principal components are obtained, it is possible to select a principal component according to a desired scale.

For the frame shape to which the evaluation value is given as described above, a representative frame shape (hereinafter referred to as a representative frame shape) is determined for each scale in the representative frame determination step.
The representative frame shape is desirably a frame shape in which the feature on the scale appears most prominently. For example, a high principal component score (preferably the highest) or a low one (preferably the lowest) of the principal component in the principal component analysis is preferable.
A progressive surface shape suitable for the determined representative frame shape is designed. The progressive surface shape is obtained by adding a sag amount to the reference progressive surface shape of the first data. Second data corresponding to the sag amount is calculated. The representative frame shape is set to at least the number of scales. For example, if two representative frame shapes are set for each scale, eight types of representative frame shapes are set if the scale is four.
Various patterns are assumed for the progressive surface shape designed into the representative frame shape. For example, it can be considered that the base curves of all representative frame shapes determined for each scale are the same. On the other hand, the base curves of all representative frame shapes determined for each scale may not be the same, that is, there may be representative frame shapes of different base curves.
Thus, when there is a margin in the design of the base curve, for example, when the frame shape is three-dimensional data, it is possible to design an optimal base curve according to the frame shape.
Further, it is conceivable that the progressive zone lengths of all the representative frame shapes determined for each scale are made constant. On the other hand, the progressive zone lengths of all the representative frame shapes determined for each scale may not be the same, that is, there may be representative frame shapes having different progressive zone lengths.
For example, for a frame having a long top and bottom width, increasing the progressive zone length can prevent the blur, the blur and the blur characteristic of the progressive lens. On the other hand, if the progressive zone length is not shortened for a frame with a short top and bottom width, the near portion of the lens will not fit within the frame.
Further, the distance-use surface power and the near-surface power for all representative frame shapes determined for each scale may be the same or may not be the same.
What is not made the same here is to keep in mind that the power of a suitable lens varies depending on the distance between the eye and the lens. For example, the effective distance diopter for the lens wearer varies depending on the distance between the apexes. That is, as the apex distance becomes longer, the substantial correction power due to the action of the lens is displaced to the plus side. In other words, a negative power lens is weak, and a positive power lens is strong. Therefore, by changing the distance dioptric power of the lens according to the apex distance, the substantial correction power can be kept constant (or the displacement can be kept small).
In addition, since the distance from the eye to the lens near portion varies depending on the apex distance and the forward tilt angle (and the progressive zone length), it is also assumed that the near power is changed according to those data.
In addition, the progressive surface correction shape of the representative data may be prepared separately depending on the frequency range such as plus and minus frequencies, or strength and weakness.

An object of the present invention is to set a weight corresponding to each scale for the shape data of an arbitrary frame shape P. Therefore, a weight is set to the shape data of an arbitrary frame shape P for each scale based on the evaluation value in the synthesis step (lens creation step). As the evaluation value, for example, a shape difference between the representative frame shape and the arbitrary frame shape P, a principal component score in the principal component analysis, and the like can be factors. The evaluation value is a unique value that is different for each scale. Therefore, the weight varies depending on the scale. The obtained weight can be considered as a different coefficient for each scale indicating the shape characteristic of an arbitrary frame shape P.
This weight is given to the progressive surface shape (second data) of the representative frame shape in each scale, a correction value is obtained, and the correction value is arbitrarily combined with the first data that is the data of the reference refracting surface It is possible to obtain composite data of progressive addition lenses having progressive characteristics suitable for the frame shape P.
If a progressive surface shape having a representative frame shape is designed based on such an idea, a progressive surface shape suitable for an arbitrary frame shape P can be obtained based on the design. This data includes sag amount data indicating how much sag is added to the reference progressive surface shape in the same manner as the sag amount is added to the first data when designing a suitable progressive surface shape for the representative frame shape. You may think. Here, “synthesis” means adding a sag amount or a shape distribution function. A specific progressive-power lens is produced based on the synthesized data.
Here, in the present invention, a correction value giving a weight to the second data is synthesized so as to add a sag to the first data as the reference plane. In other words, the progressive surface shape suitable for the representative frame shape (set according to the representative frame shape) is not designed independently, but the shape data is obtained by displacing the sag of the reference surface based on the reference surface. I try to create. As a result, if the weight (coefficient) is 0, the amount by which the sag is displaced is also 0, so that the reference progressive surface shape itself designed by the first data is a progression suitable for any frame shape P. Therefore, it is possible to obtain a progressive-power lens having a characteristic.

  In the inventions of the above claims, a progressive-power lens having progressive characteristics suitable for an arbitrary frame shape P whose distance eye point position is known is evaluated for each of many past frame shapes on a scale-by-scale basis. Is given to the second data of the progressive surface shape of the representative frame shape, so that it can be indirectly designed using the progressive surface shape of the representative frame shape. Therefore, it is not necessary to actually design the progressive characteristics of an arbitrary frame shape P, and it is possible to easily manufacture a progressive-power lens having an arbitrary frame shape P at a low cost.

Hereinafter, specific embodiments will be described with reference to the drawings.
First, an outline of a peripheral device for executing the method of the present invention will be described with reference to FIGS.
FIG. 1 is a schematic block diagram illustrating steps for realizing the method of the present invention. In the present embodiment, first, a lens characteristic data calculation step A for calculating lens data of a progressive-power lens having an arbitrary frame shape P, and a progressive suitable for an arbitrary frame shape P based on the calculated lens data. It consists of a lens manufacturing process B for manufacturing a refractive power lens. As shown in FIG. 2, in the lens characteristic data calculation step A, the lens characteristic calculation computer 1 and the frame shape measuring device 2 connected thereto, an arbitrary frame shape P or a known frame to be analyzed as a premise of design. It is assumed that shape data of the frame shape (700 types in this embodiment) is measured, and the progressive surface shape of the representative frame determined based on these known frame shapes is designed, and for each progressive surface shape of the representative frame. Are corrected using weights as coefficients, and by combining them with a reference progressive surface, a progressive surface shape suitable for an arbitrary frame shape P is finally designed.
Note that the lens characteristic calculation computer 1 and the frame shape measuring device 2 do not necessarily have to be directly connected as in the LAN connection, and conversely, the computer 1 and the frame shape measuring device 2 may be integrated. Further, it is possible to use a device other than the frame shape measuring device 2 for measuring the frame shape, and shape data measured by a plurality of frame shape measuring devices 2 may be input. Further, the shape data is not limited to the LAN, and may be transferred to the lens characteristic calculation computer 1 using a data storage device or the like (including media such as a flexible disk and a USB memory).

The lens characteristic calculation computer 1 includes a CPU (central processing unit) 11 and its peripheral devices. The CPU 11 creates progressive surface shape data of an arbitrary frame shape P based on various programs and the input progressive surface data and weight of the representative frame. The storage device 12 stores a basic program such as a program for controlling the operation of the CPU 11 and an OA processing program (for example, a Japanese input function or a printing function) that manages functions that can be commonly applied to a plurality of programs. ing. Furthermore, a program for fetching frame shape data, a program for fetching progressive surface data, a correction program for creating new progressive surface shape data by correcting the fetched progressive surface data, and the like are stored. In addition, as the progressive surface shape data, already created data can be used.
The CPU 11 corrects the reference progressive surface data in consideration of the weight with respect to the progressive surface shape data of the representative frame input based on Example 1 or Example 2 described later.
An input device 3 ( mouse, keyboard, etc.) and a monitor 5 are connected to the CPU 11. Also, it means such as the input device 3 for inputting data transferred from another device of the two-dimensional code or LAN-connected another computer or data storage device such as a bar code outside keyboard than the Can be mentioned.

The frame shape measuring apparatus 2 has a frame tracer (not shown), and obtains frame shape data by tracing along the inner diameter of the frame for which shape data is actually desired. The actual position data is included in spans multiple, in this embodiment suitably thinned X ₁ point 24 on radial line of the boxing center O to 15 degree intervals with the origin (center) as shown in FIG. 3 - X ₂₄ was adopted. Here, the boxing center is an origin that combines the maximum and minimum intermediate points of the X coordinate and the maximum and minimum intermediate points of the Y coordinate. This point is the center of the rectangle that circumscribes the frame. That is, the center position when the frame is inscribed in a rectangular shape. However, it is possible to set the origin not to the boxing center O but to any other point, for example, an eye point.

In this embodiment, frame shape data is obtained by the frame shape measuring apparatus 2, and a specific eye point YO position for each user is determined by a lens meter. The eye point YO position is specified as an XY coordinate from the boxing center O.
In this example, shape data and eye point data were obtained for a total of 700 frames to be analyzed. Since the shape data is specified as XY coordinates, it is regarded as a total of 48 variables of 24 points × 2. On the other hand, shape data and eye point data were obtained for any frame shape P by the same operation.

In the lens manufacturing process B, a CAM (computer aided) (not shown) having a material block 21 having a sufficient thickness called “semi-finish” shown in FIG. 4 based on the progressive surface shape data generated by the lens characteristic calculation computer 1. cutting).
The planar shape of the material block 21 in the present embodiment is a circular shape, and the surface thereof is a convex processed surface 22 that has been processed into a spherical shape with a predetermined curvature in advance. The back surface is a concave processed surface 23 of a predetermined base curve that is processed into a spherical shape with a predetermined curvature.
In the present embodiment, the shape data of the material block 21 is input to the CAM device, and the convex processed surface 22 side is fixed to the fixing device, and is based on the data (sag amount data) synthesized in the lens characteristic data calculation step A. By processing the concave processed surface 23 side, a progressive power lens suitable for an arbitrary frame shape P is obtained. This lens manufacturing process B is an example.

In the first and second embodiments, the process up to the stage of obtaining the sag amount data to be combined with the reference progressive surface shape of the progressive-power lens having an arbitrary frame shape P based on the shape data obtained by the frame shape measuring apparatus 2 will be described. To do.
Example 1
In Example 1, principal component analysis was used. When principal component analysis is used, it is possible to easily determine the scale as the principal component, the evaluation value as the principal component score, and the representative data according to the level of the principal component score. The weight can also be obtained based on the principal component score.
In the present embodiment, a total of 48 data were collected with 24 points for two types of data of X coordinate and Y coordinate for a total of 700 analysis target frames. The obtained data can be expressed as a data matrix as shown in FIG. In FIG. 5, a predetermined row is j and a column is k.

<Standardization of shape data for each frame shape>
First, standardize the data values obtained.
Considering 48 sets of shape data at common positions for each lens (one set consists of 700 pieces of data), the average and standard deviation of the numerical values of the 48 sets are obtained. Specifically, first, the average of each numerical value is obtained, the difference from each data is squared and summed, and this is divided by (700-1 = 699) to obtain the variance. The square root of this value is taken as the standard deviation. The general formula is as follows. Then, regarding 48 sets of frame shape data at common positions, the data matrix is standardized by subtracting the average value of each set from each of 700 sets of data and dividing by the standard deviation of each set.

<Calculation of covariance matrix>
The j-by-k element of the covariance matrix is calculated based on the standardized data matrix. This is a standardized data matrix,
1) 1 row multiplied by j column element and k column element 2) 2 rows multiplied by j column element and k column element 3) i row j column element multiplied by k column element It is obtained by calculating the sum of things.
Generally speaking, as shown in FIG. 6, a product of j column elements and k column elements of a certain row is added to all the rows.
This operation is executed by an algorithm as shown in FIG. In FIG. 7, xd [ i ] [ j ] , that is, a two-dimensional array of xd [1] [1] to xd [nn] [np] represents the elements of the data matrix of FIG. a [ j ] [ k ] , that is, a two-dimensional array of a [1] [1] to a [np] [np] represents an element of a covariance matrix. nn is the number of data, which is 700 in the embodiment. np is the number of data elements, and is 48 in the embodiment.
In this algorithm, elements of j rows and k columns are obtained in order from the top along the arrows in the figure as shown in FIG. Since it is a diagonal matrix, when obtaining an element of j rows and k columns, an element of k rows and j columns is simultaneously determined (same value).

<Calculation of principal components based on eigenvalues>
The eigenvalue is obtained by calculating the covariance matrix. The eigenvalues for each principal component (up to the fourth principal component) in this example are as shown in Table 1 below.

<Determination of scale>
In the first embodiment, the first to fourth principal components corresponding to the eigenvalues are used as a scale, and the principal component score is calculated for the analysis target frame for each of the first to fourth principal components. The first scale → the first principal component, the second scale → the second principal component, the third scale → the third principal component, and the fourth scale → the fourth principal component. FIG. 9 is a scatter diagram of the analysis target frame in which the principal component scores of each principal component are arranged on the vertical axis. The upper component score is higher in the upward direction and lower in the downward direction. Since all the analysis target frames are overlapped and are difficult to understand, FIG. 9 is illustrated with the number of frames thinned out.
The first scale corresponding to the first principal component has a frame shape that “the top and bottom width is large, the whole is large and the ear side is wide” as the principal component score is high, and the progressive power lens applied is an aberration dispersion type, The ear-side aberration is small, and the start-up is gentle. In addition, the lower the main component score is, the smaller the top and bottom width is, the overall size is small, and the nose side and the ear side are about the same size. And the ear-side aberration are of the same magnitude (hereinafter referred to as a nose-ear balance type), and the start-up of joining is strengthened.
The second scale corresponding to the second principal component is the “inverted trapezoidal square” frame shape as the principal component score is higher, and the applied progressive power lens is a somewhat aberration-dispersion type, To do. Further, the lower the main component score, the more the frame shape is “egg-shaped and wider on the ear side”. The progressive-power lens to be applied is somewhat aberration-concentrated and the ear-side aberration is small.
The third scale corresponding to the third principal component has a frame shape of “slightly egg-shaped with a lower eye point” as the principal component score is higher. Is a broad and strong start-up. In addition, the lower the main component score, the higher the eye point and the more square the shape is. The applied progressive-power lens occupies the near-field area to keep the overall aberration small, and the start-up of the addition is slow. Suppose that
The fourth measure corresponding to the fourth principal component has a frame shape that is “rounder as a whole” as the principal component score is higher, and the progressive-power lens to be applied is an aberration-concentrated type, widening the near-field, and adding It is assumed that the start-up of is slightly relaxed. In addition, the lower the main component score is, the more horizontally oriented the shape is, and the applied progressive-power lens constricts the near-use area to keep the overall aberration small, and the start-up of the addition is normal. To do.

<Determination of representative frame shape>
A representative frame shape is determined for each scale. In this embodiment, a total of eight types of representative frame shapes are determined. Select the highest and lowest principal component scores of shape data at each scale, and add the principal component vector of the length corresponding to the principal component score of those data to the reference frame shape data of the average shape Thus, a representative frame shape can be obtained. This will be specifically described below.
In the above <standardization of shape data of each frame shape>, the average of 24 measurement positions of all frames is obtained. The shape specified by the average value of 24 points is first set as a reference frame shape. Each scale (that is, the principal component) represents a frame shape displaced by adding a unique principal component vector to the reference frame shape as a principal component score.
The representative frame shape on the + side in each scale is obtained by adding the length of the maximum absolute value of the principal component score to the reference frame shape. For this purpose, the first principal component vector is normalized to size 1, the inner product of the difference vector between the data with the largest absolute value of the principal component score and the reference frame shape data is taken, and the normalized first principal component vector is obtained. By adding a vector obtained by multiplying the vector by the value of the inner product to the reference frame shape, a + side representative frame shape is obtained. Instead of adding the obtained vector to the reference frame shape, a representative frame shape on the side can be obtained. The representative frame shape calculated in the vertical position of the scatter diagram of FIG. 9 is illustrated.
For the representative frame shape in each scale obtained here, the weight index is set to +1 and the lowest representative data is set to -1. That is, the weight on each scale is +1 at the maximum and -1 at the minimum.
<Determination of weight of arbitrary frame shape P>
In the first embodiment, the weights of the frame shapes A to D as the arbitrary frame shape P are obtained.
As the weight, the principal component score for the analysis target frame is used, and the weight of an arbitrary frame shape P on the scale (principal component) is calculated.
The principal component score for the analysis target frame is expressed by the following general formula.

That is, the principal component score Zk of the k-th analysis target frame of a certain frame is represented by an inner product of 48 elements and eigenvectors. Here, a ₁ is there a set of X and Y coordinates of the values of 24 points of the frame, i is made up 1 to 48 for an element. W _{i, k} means the i-th element of the k-th principal component vector.
Therefore, it is possible to evaluate the scale by applying the frame shapes A to D to this equation. Here, the principal component scores obtained for the frame shapes A to _D are Y _A to Y _D , respectively. The frame shapes A to D are weighted between +1 and −1 by dividing by the maximum principal component score Y _MAX on the scale. In Example 1, four weights corresponding to the scales were obtained for each of the frame shapes A to D as shown in Table 2 below.
Next, four weights calculated for each scale are given to the sag amount data of the representative frame shape. Specifically, a progressive surface corresponding to the second principal component is applied to the progressive surface shape data corresponding to the first scale (more precisely, correction component data for correcting the reference progressive surface), and the first principal weight is applied. A second weight is applied to the shape data, a third weight is applied to the progressive surface shape data corresponding to the third principal component, and a fourth weight is applied to the progressive surface shape data corresponding to the fourth principal component. The sag amount data is created by summing the sag amount data, and the sag amount data is combined with the shape data of the reference progressive surface shape to obtain progressive surface shape data.
In the first embodiment, if the arbitrary frame shape P is a very special frame shape, there is a case where the principal component score is larger than the maximum principal component score Y _MAX . Here, Y _MAX is adopted in that case.

(Example 2)
Example 2 is a case where principal component analysis is not used.
<Determination of scale and representative frame shape>
In the second embodiment, the same four scales as those in the first embodiment are determined. Then, a total of eight types of representative frame shapes are selected for each scale. However, since principal component analysis is not performed in Example 2, eight types of representative data cannot be obtained based on objective evaluation values such as principal component scores. Therefore, first, the scale is determined first, and two frame shapes that are subjectively considered to be representative in each scale are selected by selecting from 700 frame shapes. Here, eight types of representative frames from F1 to F8 that give + -1 to the frame shape at the counter electrode as weighting indexes for each of the four scales following the scale of Example 1 were selected. As shown in FIG. 10, for each scale, for example, the first scale, the frame shape F1 having the “large top and bottom width, large overall and wide ear side” is selected as the + side. This is as if the frame shape F2 is selected as the negative side. Then, as in the first embodiment, progressive surface shape data suitable for each data is input.
<Determination of weight>
In all the frame shapes of the present embodiment, the frame data can be expressed in the form of { x i, y i} i = 1-24.
The specific frame data W is {Xwi, Ywi}, the positive representative frame shape F1 on the first scale is {Xai, Yai}, the negative representative frame shape F2 on the first scale is {Xbi, Ybi}.
Then, the weight related to the first scale of W can be defined by the following equation, for example. This weight is also an evaluation value.

  Therefore, if a specific frame data W is an arbitrary frame shape P, the weight of the arbitrary frame shape P can be calculated. According to the above formula, an arbitrary frame shape P is given a weight between +1 and -1. In the second embodiment, a total of four weights are calculated for each scale, and the weights are given to the sag amount data of the representative frame shape as in the first embodiment. Progressive surface shape data obtained by combining the sag amount data with the shape data of the reference progressive surface shape can be obtained.

It should be noted that the present invention can be modified and embodied as follows.
In the above embodiment, the evaluation value of the analysis target frame is obtained based on the two-dimensional data (that is, the two directions of the X axis and the Y axis) as the shape data of the arbitrary frame shape P, and the representative frame shape is determined. However, it may be determined by three-dimensional data (that is, three directions of the Z axis in addition to the X axis and the Y axis) based on the positional relationship with the vertex of the center of the black eye. By doing so, it is possible to design a progressive-power lens having a more suitable progressive surface shape according to the apex distance, the forward tilt angle, and the warp angle.
In this case, each representative frame shape has a slightly different apex distance, tilt angle, and warp angle, but the progressive surface shape data of each representative data can be designed according to such conditions. it can. By doing so, the progressive surface shape finally obtained with respect to the individual order data is optimized with respect to the apex distance, the inclination angle, and the warp angle determined based on the progressive surface shape. In addition, the apex distance, the tilt angle, and the warp angle that are “measured” in a state where the lens shape is not determined are only temporary. For example, the value is determined on the assumption that a standard lens is framed. That is, it is necessary to appropriately convert numerical values in the process of determining the lens shape. For this purpose, a detailed arrangement of the measurement method (or the exact meaning of the obtained value) is required between the lens manufacturer and the person who measures the apex distance, tilt angle, and warp angle (generally a spectacle store). Become.
According to the present invention, it is also possible to avoid such inconvenience and treat the apex distance and the forward tilt angle as accurate values corresponding to the lens actually used. In other words, a progressive surface shape corresponding to the “true vertex distance determined by the lens shape” can be obtained without directly measuring the vertex distance or setting a numerical value at the measurement stage. Can do.
The preferred progressive surface shapes of the representative frame shape need not have the same base curve. Rather, when a three-dimensional frame is considered, for example, if the warp angle is large, it is preferable that the base curve is large. Therefore, in order to provide an optimum base curve lens, it is preferable that the base curve of the progressive addition lens applied to the representative frame shape is not uniform.
・ The number of scales can be changed as appropriate.
The means for determining or selecting the representative frame shape is not limited to the above embodiment.
In the processing in the lens manufacturing process B, the surface side of the material block 21 may be processed.
In the first embodiment, a correlation matrix can be used in addition to the covariance matrix as a solution for principal component analysis.
The present invention aims to design a suitable progressive surface shape for the frame shape with the eye point position determined, but if the human face is not significantly different (except for very special cases), the eyeball Since there is no significant shift, the eye point position may be determined on the assumption that the eye point position is generally determined by the frame.
In addition, it is free to implement in a mode that does not depart from the spirit of the present invention.

Block diagram explaining the process of the present invention The schematic block diagram of the apparatus for similarly implementing this invention. Explanatory drawing explaining the measuring method of a frame shape. The front view of the material block processed in the previous step at the time of manufacturing a progressive addition lens by the method of a present Example. Explanatory drawing explaining expressing with the matrix format of the data extract | collected about the lens and each lens. Explanatory drawing explaining the method of calculating a covariance matrix based on the standardized data matrix. Explanatory drawing explaining the algorithm of calculation of a covariance matrix. Explanatory drawing explaining the process which calculates the element of a covariance matrix. Explanatory drawing explaining the characteristic frame explaining the representative frame shape and its progressive characteristic in Example 1 combining with the scatter diagram which scatters and displays the analysis object frame for every scale. Explanatory drawing explaining the relationship between four scales and the representative frame shape representing a scale in Example 2. FIG.

Explanation of symbols

  11: A CPU that executes a first data calculation step, an evaluation value determination step, a representative frame determination step, a second data calculation step, and a synthesis step.

Claims (12)

A method for designing a progressive-power lens having a progressive-surface shape with progressive characteristics suitable for an arbitrary frame shape P, which is composed of the following steps.
(A) A first data calculation step of designing a suitable reference progressive surface shape for a predetermined frame shape whose shape is specified, and calculating the reference progressive surface shape as first data.
(B) A scale setting step for determining one or more quantitative scales as an index for determining the evaluation value of the frame.
(C) Obtain shape data for each of a plurality of known frame shapes to be analyzed, analyze the difference in shape from other frame shapes for each frame shape based on the same shape data, and for each frame shape An evaluation value determination step for determining an evaluation value relative to another frame shape.
(D) Representative by adding a scale amount corresponding to an evaluation value of a typical frame shape for each scale from each frame shape to which an evaluation value is given in the evaluation value determination step. A representative frame determining step for determining a frame shape (hereinafter referred to as a representative frame shape);
(E) A suitable progressive surface shape for each representative frame shape determined in the representative frame determination step is designed by adding a sag amount to the first data obtained in the first data calculation step. A second data calculation step of calculating second data corresponding to the sag amount.
(F) Based on the evaluation value, a weight is set for the shape data of the arbitrary frame shape P for each scale, and the second data of the representative frame shape given the weight for each scale is used as a correction value. A synthesis step of synthesizing the first data and processing based on the synthesized data to obtain a progressive surface shape of the arbitrary frame shape P. A method for manufacturing a progressive-power lens having a progressive surface shape with a progressive characteristic suitable for an arbitrary frame shape P, and a method for manufacturing a progressive-power lens comprising the following steps.
(A) A first data calculation step of designing a suitable reference progressive surface shape for a predetermined frame shape whose shape is specified, and calculating the reference progressive surface shape as first data.
(B) A scale setting step for determining one or more quantitative scales as an index for determining the evaluation value of the frame.
(C) Obtain shape data for each of a plurality of known frame shapes to be analyzed, analyze the difference in shape from other frame shapes for each frame shape based on the same shape data, and for each frame shape An evaluation value determination step for determining an evaluation value relative to another frame shape.
(D) Representative by adding a scale amount corresponding to an evaluation value of a typical frame shape for each scale from each frame shape to which an evaluation value is given in the evaluation value determination step. A representative frame determining step for determining a frame shape (hereinafter referred to as a representative frame shape);
(E) A suitable progressive surface shape for each representative frame shape determined in the representative frame determination step is designed by adding a sag amount to the first data obtained in the first data calculation step. A second data calculation step of calculating second data corresponding to the sag amount.
(F) Based on the evaluation value, a weight is set for the shape data of the arbitrary frame shape P for each scale, and the second data of the representative frame shape given the weight for each scale is used as a correction value. A lens creating step of combining the first data and processing a predetermined lens precursor based on the combined data to obtain a lens having a progressive surface shape having the same frame shape P. 3. The method of manufacturing a progressive power lens according to claim 2, wherein the predetermined frame shape with the specified shape is an average frame shape based on the plurality of frame shapes. When evaluating the difference from other frame shapes for each frame shape in the evaluation value determining step, a covariance matrix or correlation matrix is derived, and an eigenvector of the determinant is calculated to determine a principal component corresponding to the eigenvector. 4. The method of manufacturing a progressive-power lens according to claim 2, wherein the main component score for each frame shape is used as an evaluation value. The method of manufacturing a progressive-power lens according to claim 2, wherein the frame shape data is three-dimensional data in which a spatial position is specified. 6. The progressive power lens according to claim 2, wherein the representative frame shape is the highest or lowest evaluation value among the plurality of frame shapes on each scale. Manufacturing method. The method for manufacturing a progressive-power lens according to any one of claims 2 to 6, wherein the base curve of the preferred progressive surface shape of the plurality of representative frame shapes determined for each scale is the same. . The method for manufacturing a progressive-power lens according to any one of claims 2 to 6, wherein the base curve is not the same for a suitable progressive surface shape of the plurality of representative frame shapes determined for each scale. The progressive power lens according to any one of claims 2 to 8, wherein a suitable progressive surface shape of the plurality of representative frame shapes determined for each scale has a constant progressive zone length. Production method. 9. The progressive power lens according to claim 2, wherein a suitable progressive surface shape of the plurality of representative frame shapes determined for each scale has a progressive zone length that is not constant. Method. 11. The preferred progressive surface shape of the plurality of representative frame shapes determined for each of the scales has a distance surface refractive power and a near surface refractive power equal to each other. A manufacturing method of the progressive-power lens as described in 2. 11. The preferred progressive surface shape of the plurality of representative frame shapes determined for each of the scales has a distant surface power or a near surface power that is not the same. The manufacturing method of the progressive-power lens of description.

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