DE102017118219A1 - Computer-implemented method for creating a target design for optimizing a free-form surface of a spectacle lens, computer program, storage medium and computer - Google Patents

Abstract

A computer-implemented method for generating a target design is disclosed. In the method, the target design (1) is obtained from interpolation between output designs (2, 3) and / or extrapolation beyond output designs (2, 3) interpolating between different values of progression length in the output designs (2, 3) or extrapolated beyond values of progression length in the initial designs (2, 3).

Description

The present invention relates to a computer-implemented method for producing a predetermined target design to be used for optimizing a free-form surface of a spectacle lens. In addition, the invention relates to a computer program, a storage medium with a computer program and a computer comprising a memory containing a computer program.

Spectacle lenses can be in those with only one dioptric effect, so-called single-vision lenses according to DIN ISO 13666: 2013-10 Section 8.3.1, and those with different focusing effects, so-called multi-intensity lenses according to DIN ISO 13666: 2013-10 , Section 8.3.2. The term "dioptric action" forms a collective term for the focusing effect and the prismatic effect of the spectacle lens, the term "focusing effect" again forms a collective term for the spherical effect, according to which a paraxial, parallel beam is focused on a point, and the astigmatic effect of the spectacle lens, according to which a paraxial, parallel beam is focused on two mutually perpendicular lines. In the context of the present description, a bundle of rays is to be regarded as a paraxial bundle of rays if it does not exceed a diameter of 0.05 mm, in particular of 0.01 mm.

The use of multiple focusing effects allows the wearer of the goggles to correct vision defects both near and far with a single lens. If the transition of effect between the far-range and the near-field is fluent, then one speaks of progressive-power lenses, as they are in DIN ISO 13666: 2013-10 , Section 8.3.5 are defined: A progressive lens is a spectacle lens with at least one progressive lens and an increasing (positive) effect when the wearer looks down. A progressive addition surface, in accordance with Section 7.7 of this standard, refers to a non-rotationally symmetric surface with a continuous change of curvature over the entire surface or a portion thereof, which generally serves to provide an increasing near addition or a degressive effect.

Nowadays, progressive lenses can be individually adapted to the measured eye on the basis of the measured refraction of a patient's eye. For this purpose, at least one of the spectacle lens surfaces, often the rear surface or eye-side surface, which is intended to face the eye in the spectacles ( DIN ISO 13666: 2013-10 , Section 5.9) provided with a freeform surface. In this case, a free-form surface constitutes a surface which is freely shapeable during production and in particular does not need to have axis symmetry and rotational symmetry and produces different effects (spherical and / or astigmatic and / or prismatic) in different regions of the spectacle lens.

In the broad sense, a free-form surface is understood to be a complex surface which can be represented in particular by means of area-wise defined functions, in particular twice continuously differentiable area-by-area defined functions. Examples of suitable area-wise defined functions are (in particular piecewise) polynomial functions (in particular polynomial splines, such as bicubic splines, higher degree splines of fourth degree or higher, Zernike polynomials, Forbes surfaces, Chebyshev polynomials, polynomial non-uniform rational B-splines (NURBS)) or Fourier series. This is to be distinguished from simple surfaces, such as spherical surfaces, aspherical surfaces, cylindrical surfaces, toric surfaces or on page 12, Z 6-13 of the WO 89/04986 A1 described areas which are described as a circle at least along a main meridian.

A free form surface in the narrower sense according to section 2.1.2 of DIN SPEC 58194 from December 2015 is a lens surface manufactured in free-form technology, which is mathematically described within the limits of the differential geometry and is neither point nor axisymmetric.

The production of free-form surfaces on a spectacle lens is usually done by machining the spectacle lens, so for example by milling, in the context of a CNC method in which the freeform surface is numerically controlled based on a mathematical description of the surface. The mathematical description of the freeform surface is typically done with the aid of area-wise defined functions. A region-wise defined function is a function which is defined between grid points of a generally planar two-dimensional grid, for example on a rectangular area of a rectangular grid, and which describes a partial area of the free-form area. For example, if the rectangular grid is in the xy plane of a Cartesian coordinate system, the area-by-area functions may be functions of the x-coordinate and the y-coordinate. Their function values then form the z coordinate assigned to a point in the xy plane, and the set of all z coordinates of a region-by-region defined function forms a subarea of the freeform surface. In the simplest case, the points of the free-form surface are then given at each location of the xy-plane by the z-coordinate. In other words, the function values of the area-wise defined functions give the respective height of a point of the freeform surface over a point of the xy-plane at. The area-wise defined functions are generally determined such that the transitions to the area-wise defined functions defined on the adjacent grid areas are continuous, at least in the first derivative, and preferably also in the second derivative. If the area-specific functions are polynomials, these are called splines.

The determination of the mathematical model of the freeform surface is effected by an optimization method in which an optical target design to be achieved is specified.

An optical target design is a distribution or specification of aberrations over the entire spectacle lens or else in the spectacle beam path (eg astigmatic residual deviation, spherical residual deviation, prism, horizontal symmetry, distortion, but also higher order errors such as coma). In addition, this target design may also contain specifications for the astigmatic and spherical residual deviations at reference points (eg, long-distance design reference point or near-design reference point) or the addition in the measurement beam path of a measuring device (eg, vertex-refractive-index meter). In the optical target design, for example, the distribution of the values to be achieved with a spectacle lens for the permissible spherical residual aberration of the spectacle lens and for the permissible astigmatic residual error in the so-called spectacle beam path, ie in a beam path that passes through the eye pupil or through the eye pivot point is indicated. Typically, these residual errors are defined in the form of individual values at a multiplicity of points on the front surface of the spectacle lens (that is, the side of the spectacle lens to be averted by the eye), the so-called optimization points. The spherical residual error is to be understood as meaning the deviation of the spherical correction from the prescription spherical correction caused by the spectacle lens, and the deviation of the astigmatic correction caused by the spectacle lens from the prescription astigmatic correction under the astigmatic residual error. As part of a beam calculation for calculating the distribution of the values for the spherical and the astigmatic residual error over the entire spectacle gas find beam use, each of which a beam, hereinafter referred to main beam, except through the lens through the eye rotation point, where the main rays pass the optimizing points through the front lens surface. As a rule, the conditions of use of the respective spectacle lens are taken into account and the freeform surface is optimized for the respective conditions of use. The conditions of use can be, for example, by the pre-tilt angle ( DIN ISO 13666: 2013-10, Section 5.18), also called the pantoscopic angle, the frame angle ( DIN ISO 13666: 2013-10 , Section 17.3) and the Corneal Vertex Distance ( DIN ISO 13666: 2013-10 , Section 5.27) and are individually adapted to the respective carrier for each spectacle lens. The term "pretilt angle" refers to an angle in the vertical plane between the normal to the front surface of a spectacle lens in the center of the box system (system of measures and definitions, which is based on a rectangle through the horizontal and vertical tangents to the outermost edges of the lens or ophthalmic blanks) and the fixation line of the eye in primary position, which is usually assumed to be horizontal. The term "mounting disk angle" is to be understood as meaning the angle between the mounting plane and the right or left disk plane, the term "disk plane" describing a plane tangent to the front surface of a demo or support disk incorporated into the spectacle frame in its geometrical disk center point ( a demo-disc or support-disc is the spectacle lens without dioptric effect used by the manufacturer in the spectacle frame for demonstration purposes) and the term "socket plane" means a plane through the two vertical center lines of the right and the left disc plane (in case the The term "corneal vertex distance" refers to the distance between the back surface of the spectacle lens and the apex of the cornea measured in the direction perpendicular to the frame plane.

In addition to the pre-tilt angle, the mounting disc angle and the corneal vertex distance in the conditions of use usually the pupillary distance in accordance with (DIN ISO 13666: 2013-10, Section 5.29), ie the distance between the centers of the pupils in the event that the eyes When looking straight ahead, fix an infinitely distant object, the centering data, ie the dimensions and distances necessary for centering the spectacle lens in front of the eye, and the object distance model, which determines for which object distance a specific point on the spectacle lens surface is optimized. The optical target design is usually defined with respect to the front lens surface, as lenses lenses are generally also defined as the far and near design reference points on the front surface, with the distance and near design reference points shown in FIGS DIN ISO 13666: 2013-10 Sections 5.13 and 5.14 are those points on the front surface of a finished spectacle lens or the finished surface of a spectacle lens in which, according to the manufacturer, the design setpoints for the remote part or the Nahteil are present

An alternative way to specify a target design is to use the target design Specify surface properties of the free-form surface, for example a surface power and a surface astigmatism at the respective optimization points, which in this case lie on the surface which is to be formed into the free-form surface. The surface power is thereby a measure of the ability of a surface section surrounding an optimization point to change the vergence (refractive index of the spectacle lens material divided by the radius of curvature of the wavefront) of a beam of light impinging on the surface section in air. The surface astigmatism at an optimization point represents the difference of the surface powers in the main sections at an optimization point of the surface. The main sections at the optimization point are the meridian planes of the surface section surrounding the optimization point with maximum and minimum curvature, the meridian planes being planes which form the center of curvature of the Contain optimization point surrounding surface portion and the normal vector of the surface portion at the optimization point. For the purpose of differentiation from the optical target design described above, the area characteristic based target design will hereinafter be referred to as the area target design. If no distinction is subsequently made with respect to the target design, then both the area target design and the optical target design should be included.

As part of an optimization process, an output spectacle lens, for example a simple single-vision spectacle lens, is predefined. The geometry of the original spectacle lens results from the spectacle wearer's refraction data and typically includes a spherical or toric back surface which is replaced by an approximation surface determined by the area-wise defined functions for optimization. For this output spectacle lens, the resulting values for, for example, the spherical residual error and the astigmatic residual error at the respective optimization points are then calculated by beam calculation and compared with the values predetermined by the target design. The beam calculation performed here calculates the values at the individual optimization points in each case for a bundle of rays whose principal ray passes through the optimization point on the front of the spectacle lens and through the eye pivot point, ie the point around which the eye turns during eye movements.

From the deviation between, for example, the given values for the spherical residual error and the astigmatic residual error on the one hand and the calculated values on the other hand, it is possible to determine an error function or a global error whose values or their value depend on the shape of the area-wise defined functions or of whose parameters depend on. This error function or this global error can be minimized by an optimization method in which the area-wise defined functions, ie their parameters, are changed in such a way that the error function finally fulfills a termination condition. The termination condition can be realized, for example, by reaching a minimum or falling below a predetermined limit value by the value of the error function. The optimized area-by-area defined functions finally represent the free-form surface. On the basis of this free-form surface, the computer-controlled processing of the rear-side lens surface takes place. In addition or as an alternative to the back surface, the optimization of the front surface (according to DIN ISO 13666: 2013-10, section 5.8) optimizes the surface of a spectacle lens that is intended to be away from the eye in the spectacles.

The aim of such an individual optimization is to provide the same visual impression for all wearers of spectacle lenses of a spectacle lens family irrespective of the values of the refraction data and regardless of the conditions of use. That is, the goal of individual optimization is to realize the same optical design for all lenses of a spectacle lens family. Under a spectacle lens family is a lot of progressive power lenses with the same increase in the effect, i. equal progression length and equal difference of the effect in the near vision zone (near part) to the effect in the far vision zone (remote part) to understand. The progression length refers to a length that defines an extent of the progression zone or the progression channel in the direction of the increase in effect. According to section 14.2.14 of DIN EN ISO 13666: 2013-10, the progression zone is the zone of transition between the far and near part of a progressive lens, or the near and intermediate part of a degressive lens. According to 14.1.25 of DIN EN ISO 13666: 2013-10, the progression channel is the area of a progressive lens that allows sharp vision for distances that are between distance and distance. As a progression length, e.g. the vertical distance in the central viewing area from the point on the eyeglass lens front surface where the increase of activity begins to the point on the front surface where the required increase in the effect of the near vision is first reached is used. Alternatively, it is e.g. It is also possible to use the length of a curved line which is in the middle of the progression zone between a point in the near part and a point in the far part, e.g. the near reference point and the far reference point.

The use of free-form surfaces leads to a significantly higher quality of a spectacle lens with regard to the imaging quality for the spectacle wearer. The spectacle lens can be both with respect to the individual refraction data of the Spectacle wearer, as well as with regard to the individual conditions of use are optimized. Free-form surfaces can be used for both single-vision and progressive lenses. In this case, the progressive lenses have a higher number of parameters, so that more parameters can be optimized for a progressive lens as it is the case with a single vision lens. Compared to a single-vision spectacle lens, the parameters progression length and position of the progression or magnitude of the addition are added to a progressive lens. The addition thereby indicates the difference between the vertex power of the spectacle lens portion for the near vision and the vertex power of the spectacle lens portion for the distance vision as measured by a method defined in the standard EN ISO 8980-2: 2004, the vertex power being the reciprocal of the paraxial distance of the image side Focal point, measured in meters, represents. The paraxial cut represents thereby the cut width for a paraxial beam.

The optimization of the free-form surface requires a target design, for example an optical target design with a distribution of values for at least one variable influencing the dioptric power of the spectacle lens which is to be achieved after optimization. The distribution of the values for the at least one variable influencing the dioptric power of the spectacle lens can be determined in particular by values at a number of optimization points defined on the front spectacle lens surface. The variables influencing the dioptric power of the spectacle lens are, in particular, a variable influencing the spherical effect (such as the spherical refractive power or the spherical residual error) or a variable influencing the astigmatic effect (such as the astigmatic residual error). Preferably, the spherical residual error and / or the astigmatic residual error are used, since the target design is then defined independently of the dioptric desired action. Each free-form surface is optimized in such a way that the deviation of the distribution, calculated by beam calculation, of values for the variable influencing the dioptric action is minimized from the distribution of the values specified in the optical target design. In the case of an area target design, a distribution of values for the surface refractive power and / or the surface astigmatism of the free-form surface are specified and the deviation of the distribution of the values for the surface power and / or the surface astigmatism of the current free-form surface from the distribution of the values for the surface power and / or the surface astigmatism of the surface target design.

The free-form surfaces for progressive lenses differ from each other depending on the value that the addition can assume. Typically, there are values for the addition between 0.75D (diopters) and 3.5D in 0.25D increments so that free-form surfaces can be made with 12 different values for addition. In addition, depending on the effect for the distance view for the production of the free-form surface, a starting spectacle lens from a set of standard spectacle lenses is used, which may differ from each other by their basic curvatures. There are typically 9 basic curves. In the context of the present invention, the basic curvature of the spectacle lens is understood to mean the curvature of the spectacle lens at the remote construction reference point, the distance of the reference lens relative to the spectacle lens according to FIG DIN ISO 13666: 2013-10 Section 5.8 indicates that point on the front surface of the original or finished lens of the spectacle lens in which, as specified by the manufacturer, the design reference values for the remote part (the part having the dioptric power for distance vision) of the spectacle lens are given , Furthermore, the free-form surfaces to be produced in the progression lengths or in the gradients of the progression can differ from one another. In the case of progression lengths, there are typically three different progression lengths. In addition, in the production of free-form surface and the refractive index of the lens material to be considered. There are typically 6 materials with different refractive indices. Since there must be a target design for every possible combination of the mentioned parameters, a high number of target designs must be provided. In the present example, 12 × 9 × 3 × 6 = 1944 target designs are to be provided. This is true regardless of whether the target designs are optical target designs or surface target designs. If additional parameters, such as hard or soft glass designs, are added, the number of target designs to be kept may increase further. As a rule, the manufacturers have several progressive lens products in their portfolio that differ, for example, from a tougher / softer lens design.

One method of reducing this high number of target designs is in the DE 10 2008 015 189 A1 disclosed. This document discloses a computer-implemented method for generating a target design for a progressive lens with a predetermined addition, wherein the target design comprises a target astigmatism distribution of the eyeglass-eye system for the addition. The method comprises, on the one hand, defining a start design and a start target astigmatism distribution for a given base addition which is not equal to the predetermined addition. On the other hand, the method comprises calculating the desired astigmatism distribution for the given addition by means of a Transformation of the start-target astigmatism distribution. The transformation of the start-target astigmatism distribution is a multiplication of the start-target astigmatism distribution with a scaling factor s. The scaling factor s is dependent on a factor t, which in turn depends on the given addition and / or the refractive power for the distance vision and / or the base addition. The transformation should no longer require complex and error-prone interpolation for the effect and addition between predefined target distributions.

The EP 1 830 222 A1 describes the determination of a progressive spectacle lens, wherein an output distribution for the refractive power and the target astigmatism distribution are selected for each viewing direction. On the basis of the initial distribution and on the basis of measured values of calculated transformation coefficients, a personalized refractive power and a personalized target astigmatism distribution are determined.

The WO 2004/046792 A1 describes a method for designing a progressive spectacle lens by modifying a reference design.

The WO 2007/056797 A1 describes a method for designing and / or selecting a spectacle lens design wherein a selected initial design is modified.

The WO 2006/116820 A1 describes an array of progressive lens elements, each of the progressive lens elements having a design defined by a number of parameters.

The JP 2004-163787 describes a method of manufacturing a progressive lens based on frame shape information in which a difference between the desired frame shape and an output frame shape is determined as numerical data. From the numerical data, eyeglass lens data for the original frame shape will be modified to provide a recipe free form surface for the desired frame shape.

Starting from DE 10 2008 015 189 A1 It is an object of the present invention to provide an advantageous computer-implemented method and a corresponding device for creating a target design to be used for optimizing a free-form surface of a spectacle lens, with which the number of target designs to be provided can be reduced without the calculation of a scaling factor is necessary. Further objects of the present invention are to provide an advantageous computer program, an advantageous computer-readable storage medium, and an advantageous computer.

The first object is achieved by a computer-implemented method according to claim 1 and an apparatus according to claim 12. The further objects are achieved by a computer program according to claim 9, a computer-readable storage medium according to claim 10 and a computer according to claim 11. The dependent claims contain advantageous embodiments of the present invention.

In the computer-implemented method of generating a target design according to the invention, the target design is obtained from interpolation between output designs and / or extrapolation beyond output designs. It interpolates between different values of the progression length in the initial designs or extrapolates beyond values of the progression length in the initial designs. The term "initial designs" should be understood to mean target designs for spectacle lenses that serve as a starting point for the interpolation. The target designs and the seed target designs can be optical target designs or surface target designs.

The fact that the method according to the invention eliminates the need to store target designs for all progression lengths makes it possible to reduce the number of target designs to be provided. The creation of a target design by interpolation or extrapolation can be realized in particular in the case of a linear interpolation or extrapolation with little computational effort, so that the determination of the target design takes little time.

A device which complements the method according to the invention comprises a provision device for providing output designs and a computing device which is set up to generate a target design in which the target design is obtained from an interpolation between a progression-length output design and / or extrapolation over a progression-length output design becomes. According to the invention, the device is characterized in that the computing device is set up to interpolate between different values of the progression length in the output designs or to extrapolate beyond values of the progression length in the output designs. The provisioning means may e.g. an electronic memory on which a representation of the initial designs is stored in electronic form.

In particular, the target design and the initial designs to be determined may each be in the form of values at a number of specific points located on the front surface of the spectacle lens, especially at a number on the front surface of the lens located optimizing points, be given. It is advantageous if the points in the initial designs all have the same coordinates. The coordinates of the points of the target design are then equal to the coordinates of the points of the initial designs. This makes it possible to create the target design solely by interpolating or extrapolating the presets to the optical properties to be achieved at the points. But even if the coordinates of the points in the initial designs do not match, the target design can be determined by means of interpolation or extrapolation, as long as there is a clear correlation between the individual points of the respective initial designs. In a first step, interpolation between the values of the n spectacle lens parameters at the mutually uniquely assigned points or extrapolation via the values of the n spectacle lens parameters at the points unambiguously associated with each other is performed for this purpose. In a second step, the coordinates of the individual points of the respective initial designs are then interpolated or extrapolated via the coordinates of the individual points of the respective initial designs in order to obtain the coordinates of the points for the target design. If the points at which the values of the target design are given are the optimization points, this has the advantage that with the interpolated / extrapolated target design the optimization can be carried out without first obtaining from the points where the values of the target design are given to determine the values at the optimization points.

In addition to the interpolation between different values of the progression length in the initial designs or the extrapolation beyond values of the progression length in the initial designs, it is possible to interpolate between further spectacle lens parameters of the original designs or extrapolate beyond further spectacle lens parameters of the initial designs. The term "spectacle lens parameter" here denotes a variable which characterizes a property of the spectacle lens which is used to characterize the target design. The interpolation between or extrapolation via further spectacle lens parameters can greatly reduce the number of target designs to be kept. The further spectacle lens parameters in the method according to the invention comprise at least at least one of the parameters "recipe effect", "refractive index", "addition", "glass design type". The parameter "glass design type" describes e.g. hard or soft glass designs or different distributions of the spherical or astigmatic residual defects in the periphery of the spectacle lens. Compared to a hard design, the maximum lateral astigmatism is usually lower in a soft design. For the soft design, the areas in the near and far parts of the lens, in which the residual errors for the wearer are comparatively low, are smaller. In addition, the progression channel is usually wider with a softer design and has smoother transitions than a hard design.

A computer program according to the invention contains program code for carrying out the computer-implemented method according to the invention when the program code is loaded into a computer and / or executed on a computer.

A computer-readable storage medium according to the invention contains a computer program with a program code for carrying out all inventive method steps when the computer program is loaded or executed in a computer.

A computer according to the invention comprises a memory which stores a computer program with a program code for carrying out all method steps according to the invention and a processor for executing the program stored in the memory.

• 1 zeigt ein Ablaufdiagramm für das computerimplementierte Verfahren zum Erstellen eines für eine Optimierung einer Freiformfläche eines Brillenglases zu verwendenden Zieldesigns.
• 2 zeigt einen Ausschnitt aus einem Beispiel für eine in dem Verfahren aus 1 zu verwendende Matrix.
• 3 zeigt die Verteilung des astigmatischen Restfehlers für ein Ausgangsdesign, welches einem Zieldesign mit einer Addition von 2,0 D entspricht.
• 4 zeigt die Verteilung des astigmatischen Restfehlers für ein Ausgangsdesign, welches einem Zieldesign mit einer Addition von 3,0 D entspricht.
• 5 zeigt die Verteilung des astigmatischen Restfehlers für ein Zieldesign mit einer Addition von 2,5 D, welches das Ergebnis einer Interpolation des Ausgangdesigns aus den 3 und 4 ist.

Further features, properties and advantages of the present invention will become apparent from the following embodiment with reference to the accompanying figures.

• 1 shows a flowchart for the computer-implemented method for creating a target design to be used for optimizing a free-form surface of a spectacle lens.
• 2 shows a portion of an example of one in the method 1 to be used matrix.
• 3 shows the distribution of the astigmatic residual error for an initial design, which corresponds to a target design with an addition of 2.0 D.
• 4 shows the distribution of the astigmatic residual error for an initial design, which corresponds to a target design with an addition of 3.0 D.
• 5 shows the distribution of the astigmatic residual error for a target design with an addition of 2.5 D, which is the result of an interpolation of the output design from the 3 and 4 is.

An exemplary embodiment of the computer-implemented method according to the invention for creating a target design to be used for optimizing a free-form surface of a spectacle lens with n spectacle lens parameters is described below with reference to the figures. In the target design is determined by means of initial designs for spectacle lenses, the initial designs being target designs for spectacle lenses with specific combinations of values of the spectacle lens parameters. The target design and output target designs may be optical target designs or area target designs. In the present embodiment, an optical target design is used.

In the present exemplary embodiment, a multidimensional matrix with n matrix dimensions is provided (step S1 in 1 ), each matrix dimension being associated with one of the n spectacle lens parameters. The term "matrix" in the context of the present invention designates an at least n-dimensional arrangement of cells, so-called matrix cells, whose entries each correspond to a unique combination of values of the n spectacle lens parameters. The number of dimensions is given by the number of n spectacle lens parameters, each matrix dimension representing values for one of the n spectacle lens parameters. In the present embodiment, n = 5, where the matrix dimensions are assigned to the following spectacle lens parameters: "prescription effect", "addition", "progression length", "refractive index" and "glass design type". 2 For reasons of clarity, only a section of a matrix with n = 2 is shown, wherein the matrix dimensions correspond to the parameters "recipe effect" and "addition".

In the present exemplary embodiment, the parameter "recipe effect" indicates the effect of the remote part, that is to say the desired value for the sphere when looking through the long range of the spectacle lens. In the present exemplary embodiment, this can assume values between -10.0 D and +7.0 D in increments of 0.01 D, ie 1,701 different values. For four values, namely +5.0 D, 0.0 D, -5.0 D and -8.5 D, initial designs are stored in the present exemplary embodiment.

In the present exemplary embodiment, the parameter "addition" can assume values between 0.5 D and 3.5 D in increments of 0.01 D, ie 301 different values. For three values, namely for 1.0 D, 2.0 D and 3.0 D, initial designs are stored in the present exemplary embodiment.

The parameter "progression length" indicates the value for the grinding height in the present exemplary embodiment. The grinding height describes the vertical coordinate of the remote centering point (in accordance with DIN 58208, Fig 1 ). In the present exemplary embodiment, the value for the grinding-in height can be in increments of 0.1 mm between 14.0 mm and 20.0 mm, ie 61 different values. For two values, namely for 14 mm and 20 mm, initial designs are deposited in the present exemplary embodiment.

The parameter "refractive index" can take in the present embodiment in increments of 0.01 D values between 1.49 and 1.75, ie 27 different values. For three values, namely 1.5, 1.6 and 1.7, initial designs are stored in the present exemplary embodiment. In reality, the parameter "refractive index" can be subdivided more precisely, for example in increments of 0.001 ° D or even 0.0001 ° D.

In the present exemplary embodiment, the parameter "glass design type" can take 101 steps between the borderline cases "hard design" and "soft design." For the borderline cases "hard design" and "soft design", initial designs are deposited in the present exemplary embodiment.

Overall, the matrix thus has 1,701 × 301 × 61 × 27 × 101 = 85,169,830,347 matrix cells 20 which correspond to 85,169,830,347 different combinations of parameter values. Each combination of parameter values requires its own target design, but at least it is advantageous to have its own target design for each of the combinations. For 4 × 3 × 2 × 3 × 2 = 144 combinations, ie for 144 special matrix cells 22 of the 76,500,000,000 matrix cells 20 , Initial designs are stored in the present embodiment.

When determining the target design, go to step S2 first, a query as to whether the combination of values of the lens parameters for the target design to be created is the combination of one of the 144 special matrix cells 22 equivalent. If yes, the procedure in step S3 the appropriate initial design as the target design. If the combination of values of the spectacle lens parameters for the target design to be determined does not correspond to any combination of the 144 special matrix cells, so the target design in the present embodiment in step S4 determined by a linear interpolation and / or a linear extrapolation of the initial designs. In the case of interpolation, this is done between the initial designs of those particular matrix cells 22 that of the matrix cell 20 closest to the parameter combination of the target design to be created. In the case of extrapolation, this is done via the initial designs of those particular matrix cells 22 that of the matrix cell 20 for the parameter combination of the target design to be created closest. An interpolation is performed, for example, when the matrix cell representing the parameter combination of the target design to be created 20 within the by the entirety of the special matrix cells 22 given matrix area lies. Is the matrix cell representing the parameter combination of the target design to be created 20 on the other hand, outside of the total of the special matrix cells 22 Given matrix area, it takes place an extrapolation. For programmatic reasons, the target designs for the combinations of parameter values corresponding to the specific matrix cells can also be determined by interpolation or extrapolation, for example using factors 0 and 1 , If a combination of parameter values corresponds to one of the special matrix cells, the factor for interpolation or extrapolation may be the factor of the output design of this particular matrix cell 1 and the output designs of the other special matrix cells used in interpolating and extrapolating, respectively 0 be assigned to.

In the present exemplary embodiment, the initial designs are all given by a distribution, to be achieved after the optimization, of values for the spherical residual error of the spectacle lens and the astigmatic residual error of the spectacle lens. However, other parameters influencing the dioptric power of the spectacle lens may also be used in the target designs, as mentioned above.

In the present embodiment, moreover, the coordinates of the optimization points on the spectacle lens are the same for each output design. In this case, the interpolation between the output designs or the extrapolation via the output designs can be effected by between the values of the output designs to be achieved at the respective optimization points, in the present exemplary embodiment between the values for the spherical power and between the values for the astigmatic power Residual error, is interpolated or extrapolated beyond these values. The target design is then given by the interpolated or extrapolated values at optimization points, and the coordinates of the optimization points of the target design are equal to the coordinates of the optimization points of the initial designs. However, even if the coordinates of the optimizer points in the output designs do not match, the interpolation or extrapolation can determine the target design if there is a unique mapping between the optimizers in the output designs, ie if each optimization point of one output design in the other output designs is accurate an optimization point is assigned. In a first step S4 - 1 is then interpolated between the values of the initial designs to be achieved at the mutually associated optimization points, in the present exemplary embodiment therefore between the values for the spherical refractive power and between the values for the astigmatic residual error. or extrapolated beyond these values to obtain interpolated or extrapolated values. Subsequently, in a further step S4 - 2 an interpolation between the coordinates of the associated optimization points of the output designs used and an extrapolation over the coordinates of the associated optimization points of the output designs used to obtain interpolated or extrapolated coordinates for the optimization points of the target design to be created. The target design is then given by the interpolated or extrapolated values at optimization points with the interpolated or extrapolated coordinates.

The 3 to 5 show the distribution of astigmatic residual error for an initial design 2 , which corresponds to a target design with an addition of 2.0 D ( 3 ), for a home design 3 , which corresponds to a target design with an addition of 3.0 D ( 4 ) and one of these initial designs 2 . 3 Target design obtained by linear interpolation 1 with an addition of 2.5 D ( 5 ). In addition, in the figures, the remote reference point 4 and the national reference point 5 , between which is the progression channel 6 extends. The values for the astigmatic residual error are indicated in the figures in the form of contour lines, the contour lines in each case representing the course of specific values for the astigmatic residual error. The values for the astigmatic residual error represent those values which a spectacle lens should have after the optimization of its free-form surface using the respective target design.

As can be seen from the exemplary embodiment, the method according to the invention reduces the number of target designs to be provided 1 by several orders of magnitude. Although the method according to the invention has been described in the context of the embodiment with reference to a progressive lens, it can also be used for the creation of target designs for single vision lenses. Here are some matrix dimensions omitted, for example, the addition and the progression length. The matrix then contains primarily two matrix dimensions which correspond to the parameters "recipe effect" and "refractive index". In the case of single-vision lenses, a matrix dimension with regard to the grinding-in height and with regard to the different types of glass design (eg with different compromises with regard to the distributions of the spherical and astigmatic residual defects) is also conceivable.

Since the target designs for each individual combination of parameter values of a spectacle lens are not calculated completely from the bottom up but by interpolation or extrapolation, this type of calculation leads to two target designs 1 for slightly different values in the recipe effect, even slightly different from each other. This increases, for example, the compatibility of spectacle lenses, in which the values in the prescription effect for the right and the left eye differ only slightly from each other. In addition, in each matrix dimension, that is, for each parameter that produces optimally desired target design.

The inventive method for creating a target design is applicable both for the creation of target designs for spectacle lenses with front side, as well as for spectacle lenses with rear free-form surface. Furthermore, the method according to the invention can also be used for the production of target designs for spectacle lenses having bilateral free-form surfaces.

The present invention has been described in detail with reference to an embodiment for explanation purposes. A person skilled in the art, however, recognizes that deviations from the exemplary embodiment are possible and can be deviated from the exemplary embodiment. For example, the number of output designs may be higher or lower than in the embodiment. In addition, more or fewer than five parameters, that is more or less than five matrix dimensions can be used. For example. In addition, a parameter "prism" can be used whose value describes the prismatic effect of the spectacle lens. An example with less than five parameters has already been described above. Furthermore, in the exemplary embodiment, only between the two output designs closest to one another in the matrix was interpolated or extrapolated via the two output designs closest to one another in the matrix. In general, however, more than just the two closest starting designs in the matrix can be used for the interpolation or the extrapolation. It is also possible to use more complex interpolations and / or more complex extrapolations instead of linear interpolation or extrapolation. The invention should therefore not be limited to the embodiment, but only by the appended claims.

LIST OF REFERENCE NUMBERS

1

target design

2

output design

3

output design

4

Remote reference point

5

Nahreferenzpunkt

6

progression channel

S1

Deploy multidimensional matrix

S2

query

S3

Output initial design as target design

S4

Interpolate and / or extrapolate

S4-1

Interpolate between values which are to be achieved at mutually allocated optimization points or extrapolate over values to be achieved at mutually allocated optimization points

S4-2

Interpolate between the coordinates of the optimally assigned optimization points and / or extrapolating beyond the coordinates of the optimally assigned optimization points

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 8904986 A1 [0005]
• DE 102008015189 A1 [0018, 0024]
• EP 1830222A1 [0019]
• WO 2004/046792 A1 [0020]
• WO 2007/056797 A1 [0021]
• WO 2006/116820 A1 [0022]
• JP 2004163787 [0023]

Cited non-patent literature

• DIN ISO 13666: 2013-10 [0002, 0003, 0004, 0009, 0010, 0017]
• DIN SPEC 58194 [0006]
• DIN ISO 13666: 2013-10, [0009]

Claims (13)

A computer-implemented method for generating a target design, in which the target design (1) is obtained from an interpolation between a progression-length initial design (2, 3) and / or extrapolation over a progression-length initial design (2, 3), characterized that interpolates between different values of the progression length in the initial designs (2, 3) or extrapolates beyond values of the progression length in the initial designs (2, 3). Computer-implemented method according to Claim 1 , characterized in that the creation of the target design (1) is carried out by a linear interpolation and / or extrapolation. Computer-implemented method according to Claim 1 or Claim 2 , characterized in that the target design (1) to be determined and the initial designs (2, 3) are each in the form of values at a number of specific points located on the spectacle lens. Computer-implemented method according to Claim 3 characterized in that the points in the initial designs (2, 3) all have the same coordinates and the coordinates of the points of the target design (1) are equal to the coordinates of the points of the output designs (2, 3). Computer-implemented method according to Claim 3 , characterized in that an unambiguous relationship between the individual points of the respective output designs (2, 3) is present, interpolated in a first step between the values of the n spectacle lens parameters at the points uniquely assigned to one another or via the values of the n spectacle lens parameters to one another is extrapolated uniquely assigned points and is interpolated in a second step between the coordinates of the individual points of the respective output designs (2, 3) or extrapolated over the coordinates of the individual points of the respective output designs (2, 3) to the coordinates of the points for the To obtain target design (1). Computer implemented method according to one of Claims 3 to 5 , characterized in that the points are optimizing points located on the spectacle lens Computer implemented method according to one of Claims 1 to 6 , characterized in that, in addition to the interpolation between different values of the progression length in the initial designs (2, 3) and the extrapolation beyond values of the progression length in the initial designs (2, 3), interpolated between further spectacle lens parameters of the initial designs or via further spectacle lens parameters extrapolated from the original designs. Computer implemented method according to one of Claims 1 to 7 , characterized in that the n spectacle lens parameters comprise, in addition to the spectacle lens parameter progression length, at least the spectacle lens parameter prescription effect and / or the spectacle lens parameter refractive index and / or the spectacle lens parameter addition and / or the spectacle lens parameter glass design type. A computer-implemented method for calculating the geometry of a spectacle lens by an optimization method in which the optimization based on a target design to be achieved, is carried out, characterized in that the target design according to a method according to any one of Claims 1 to 8th was generated. Computer program with program code for carrying out the computer-implemented method according to one of the preceding claims, when the program code is loaded into a computer and / or executed on a computer. Computer-readable storage medium having a computer program with a program code for performing all method steps according to one of Claims 1 to 9 when loading or running the computer program on a computer. Computer comprising a memory comprising a computer program with a program code for carrying out all method steps according to one of Claims 1 to 9 stores and a processor for executing the program stored in the memory. Device comprising a provisioning device for providing output designs (2, 3) and a computing device which is set up for generating a target design (1), in which the target design (1) consists of interpolation between progression-lengthed initial designs (2, 3) and / or obtained from an extrapolation over a progression length output design (2, 3), characterized in that the computing means is arranged to interpolate between different values of the progression length in the output designs (2, 3) or beyond values of the progression length into the To extrapolate initial designs (2, 3).

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