Determination of optical lens machining process signatures

Abstract

A system for determining a signature of an optical lens machining process, the system being configured to: determine: at least two error maps respectively associated with at least two optical lenses machined using the optical lens machining process, at least one surface treatment defect in a first error map of the at least two error maps, at least one surface treatment defect in a second error map of the at least two error maps, -at least one surface treatment defect in a second one of the at least two error maps,-removing the at least one surface treatment defect in a first one of the at least two error maps from a first one of the at least two error maps to obtain a first updated error map, removing at least one surface treatment defect in a second one of the at least two error maps from the second one of the at least two error maps to obtain a second updated error map, and determining a signature of the optical lens machining process by averaging at least the first updated error map and the second updated error map.

Description

Technical Field

[0001] This disclosure relates to the field of manufacturing of optical lenses. This disclosure relates to a system for determining a process signature of an optical lens machine during a machining process and a method for determining a process signature of an optical lens machine during a machining process. Background Art

[0002] Optical prescription laboratories produce optical lenses with optical powers in sequence, with some tolerances. Due to deviations during the surface treatment process, the optical properties (such as optical power) measured at different reference points are not always within these tolerances.

[0003] US2017 / 232575 A1 discloses a method for determining the position of a lens machining tool in a lathe configured for machining ophthalmic lenses.

[0004] Statistical analysis is usually performed manually or automatically by process engineers in optical prescription laboratories to determine the distribution of lens power deviations between the nominal optical power and the achieved optical power. Using this statistical analysis, the process engineer can determine the average deviation and then statically define the compensation to be applied in a lens design system (LDS) or an optical calculator.

[0005] However, this compensation is done at a single point and thus cannot handle different deviations according to different zones of the lens.

[0006] Therefore, there is a need to determine the process signature of an optical lens machine during a machining process, for example to compensate for deviations in the manufacturing process of lenses to be manufactured subsequently. Summary of the Invention

[0007] To this end, a system for determining the signature of an optical lens machine during a machining process is disclosed. According to this disclosure, the system for determining the signature of an optical lens machine during a machining process is at least configured to:

[0008] - Determine:

[0009] · At least two error maps respectively associated with at least two optical lenses machined using an optical lens machine machining process,

[0010] · At least one surface treatment defect in a first error map among the at least two error maps,

[0011] · At least one surface treatment defect in a second error map among the at least two error maps,

[0012] - Remove at least one surface treatment defect in the first error map among the at least two error maps from the first error map among the at least two error maps to obtain a first updated error map,

[0013] - Remove at least one surface treatment defect from the second error map among at least two error maps to obtain a second updated error map.

[0014] - Determine the signature of the optical lens processing process by averaging at least the first updated error map and the second updated error map.

[0015] Therefore, the disclosed solution allows for the determination of the signature process of the optical lens processing process.

[0016] According to additional embodiments that can be considered individually or in combination:

[0017] - The system includes:

[0018] · A memory that stores computer-executable code and is configured to store:

[0019] ○ An input that includes at least one parameter of the optical lens measured at multiple control points of the optical lens,

[0020] ○ A first target map and a second target map, the first target map includes first target values of optical parameters at multiple control points, the second target map includes second target values of optical parameters at multiple control points, and

[0021] · A processor that is configured to execute the stored computer-executable code to generate an optical parameter map of the optical lens based on the input.

[0022] - The signature process is created by default by the machining process without any surprises.

[0023] - The error map is calculated by the processor as the difference between the theoretical optical parameter map and the measured optical parameter map at multiple control points, and the theoretical optical parameter map is the optical parameter map expected at multiple control points after the optical lens is machined.

[0024] - The first error map among at least two error maps is associated with the first optical lens among at least two optical lenses, and the processor determines the first error map among at least two error maps by subtracting the first target map and the first optical parameter map. The first optical parameter map includes the values of the optical parameters of the first optical lens among at least two optical lenses at multiple control points, and the first target map includes the first target values of the optical parameters at multiple control points.

[0025] - The second error map among at least two error maps is associated with the second optical lens among at least two optical lenses. The processor determines the second error map by subtracting the second target map and the second optical parameter map. The second optical parameter map includes the values of the optical parameters of the second optical lens among at least two optical lenses at multiple control points, and the second target map includes the second target values of the optical parameters at multiple control points; and / or

[0026] - The optical parameters of the first optical lens among at least two optical lenses include parameters representing the optical power of the first optical lens among at least two optical lenses at multiple control points, and / or the optical parameters of the second optical lens among at least two optical lenses include parameters representing the optical power of the second optical lens among at least two optical lenses at multiple control points; and / or

[0027] - The parameters representing the optical power of the first optical lens among at least two optical lenses at multiple control points are characterized by the average spherical lens, the average cylindrical lens, and / or the average axis position, and / or the optical power of the second optical lens among at least two optical lenses at multiple control points is characterized by the average spherical lens, the average cylindrical lens, and / or the average axis position; and / or

[0028] - The processor of the system is configured to average the first updated error map and the second updated error map by averaging the values at at least one control point among the control points of the first updated error map and the values at at least one control point among the control points of the second updated error map; and / or

[0029] - Averaging the values at at least one control point among the control points of the first updated error map and the values at at least one control point among the control points of the second updated error map is based on a weighted sum that takes into account the first quality score associated with the first updated error map and the second quality score associated with the second updated error map; and / or

[0030] - The optical lens is a single - vision lens or a progressive multifocal lens or a multifocal lens; and / or

[0031] - The distance between two control points is greater than or equal to 1 μm and less than or equal to 30 mm; and / or

[0032] - At least one surface - treatment defect in the first error map among at least two error maps includes a first surface - treatment ring and / or a first central defect, and / or wherein, at least one surface - treatment defect in the second error map among at least two error maps includes a second surface - treatment ring and / or a second central defect; and / or

[0033] - The processor of the system is configured to:

[0034] · Compare the values of the optical parameters at at least some of these control points with an optical parameter extraction threshold, and

[0035] · Extract an updated error map from averaging the updated error map, which has optical parameters greater than or equal to the optical parameter extraction threshold at at least some of the control points; and / or

[0036] - The processor of the system is configured to

[0037] · Compare the values of the optical parameters at at least some of these control points with an optical parameter correction threshold,

[0038] · Before averaging the updated error map, correct the updated error map that has optical parameters greater than or equal to the optical parameter correction threshold at at least some of these control points.

[0039] This disclosure further relates to a system for compensating for the signature of an optical lens machining process, the system including a system for determining the signature of an optical lens machining process, the system being configured to:

[0040] - Determine

[0041] · At least two error maps respectively associated with at least two optical lenses machined using an optical lens machining process,

[0042] · At least one surface treatment defect in a first error map among the at least two error maps,

[0043] · At least one surface treatment defect in a second error map among the at least two error maps,

[0044] - Remove at least one surface treatment defect in the first error map among the at least two error maps from the first error map to obtain a first updated error map,

[0045] - Remove at least one surface treatment defect in the second error map among the at least two error maps from the second error map to obtain a second updated error map,

[0046] - Determine the signature of the optical lens machining process by at least averaging the first updated error map and the second updated error map,

[0047] Wherein, the system is further configured to adapt the optical lens machining process using the signature of the optical lens machining process when machining the third optical lens, such that the third optical parameter map of the third optical lens is closer to the third target map than the first optical parameter map from the first target map or the second optical parameter map from the second target map. The third optical parameter map includes the values of the optical parameters of the third optical lens at a plurality of control points, and the third target map includes the third target values of the optical parameters at the plurality of control points.

[0048] According to additional embodiments that can be considered individually or in combination:

[0049] - The signature process is created by default by the machining process without any exceptions.

[0050] - The error map is calculated by the processor as the difference between the theoretical optical parameter map and the measured optical parameter map at a plurality of control points. The theoretical optical parameter map is the optical parameter map expected at the plurality of control points after the optical lens is machined.

[0051] - The first error map among at least two error maps is associated with the first optical lens among at least two optical lenses. The processor determines the first error map among at least two error maps by subtracting the first target map and the first optical parameter map. The first optical parameter map includes the values of the optical parameters of the first optical lens among at least two optical lenses at a plurality of control points, and the first target map includes the first target values of the optical parameters at the plurality of control points.

[0052] - The second error map among at least two error maps is associated with the second optical lens among at least two optical lenses. The processor determines the second error map by subtracting the second target map and the second optical parameter map. The second optical parameter map includes the values of the optical parameters of the second optical lens among at least two optical lenses at a plurality of control points, and the second target map includes the second target values of the optical parameters at the plurality of control points; and / or

[0053] - The optical parameters of the first optical lens among at least two optical lenses include parameters representing the optical power of the first optical lens among at least two optical lenses at a plurality of control points, and / or the optical parameters of the second optical lens among at least two optical lenses include parameters representing the optical power of the second optical lens among at least two optical lenses at a plurality of control points; and / or

[0054] - The parameters representing the optical power of the first optical lens among at least two optical lenses at a plurality of control points are characterized by the mean spherical lens, the mean cylindrical lens, and / or the mean axis position, and / or the optical power of the second optical lens among at least two optical lenses at a plurality of control points is characterized by the mean spherical lens, the mean cylindrical lens, and / or the mean axis position; and / or

[0055] - The processor of the system is configured to average the first updated error map and the second updated error map by averaging the values at at least one control point among the control points of the first updated error map and the values at at least one control point among the control points of the second updated error map for at least one of the control points; and / or

[0056] - Averaging the values at at least one control point among the control points of the first updated error map and the values at at least one control point among the control points of the second updated error map is based on a weighted sum that takes into account a first quality score associated with the first updated error map and a second quality score associated with the second updated error map; and / or

[0057] - The optical lens is a single vision lens or a progressive multifocal lens or a multifocal lens; and / or

[0058] - The distance between two control points is greater than or equal to 1 μm and less than or equal to 30 mm; and / or

[0059] - At least one surface treatment defect in the first error map among at least two error maps includes a first surface treatment ring and / or a first central defect, and / or wherein at least one surface treatment defect in the second error map among at least two error maps includes a second surface treatment ring and / or a second central defect; and / or

[0060] - The processor of the system is configured to:

[0061] · Compare the values of the optical parameters at at least some of these control points with an optical parameter extraction threshold, and

[0062] · Extract an updated error map from the averaging of the updated error maps, the updated error map having optical parameters greater than or equal to the optical parameter extraction threshold at at least some of the control points; and / or

[0063] - The processor of the system is configured to

[0064] · Compare the values of the optical parameters at at least some of these control points with an optical parameter correction threshold,

[0065] · Before averaging the updated error maps, correct the updated error maps having optical parameters greater than or equal to the optical parameter correction threshold at at least some of these control points.

[0066] This disclosure further relates to a method for determining a processing signature of an optical lens grinding machine, the method comprising:

[0067] - Determining:

[0068] · At least two error maps respectively associated with at least two optical lenses machined during an optical lens machining process,

[0069] · At least one surface treatment defect in a first error map among the at least two error maps,

[0070] · At least one surface treatment defect in a second error map among the at least two error maps,

[0071] - Removing at least one surface treatment defect in the first error map among the at least two error maps from the first error map among the at least two error maps to obtain a first updated error map,

[0072] - Removing at least one surface treatment defect in the second error map among the at least two error maps from the second error map among the at least two error maps to obtain a second updated error map,

[0073] - Determining a signature of the optical lens machining process by at least averaging the first updated error map and the second updated error map.

[0074] According to additional embodiments that can be considered individually or in combination:

[0075] - The signature process is created by default by the machining process without any surprises,

[0076] - The error map is calculated as the difference between a theoretical optical parameter map and a measured optical parameter map at multiple control points, where the theoretical optical parameter map is the optical parameter map expected at multiple control points after the optical lens is machined,

[0077] - The first error map among the at least two error maps is associated with the first optical lens among the at least two optical lenses, and the processor determines the first error map among the at least two error maps by subtracting a first target map and a first optical parameter map, where the first optical parameter map includes the values of the optical parameters of the first optical lens among the at least two optical lenses at multiple control points, and the first target map includes the first target values of the optical parameters at multiple control points,

[0078] - The second error map among the at least two error maps is associated with the second optical lens among the at least two optical lenses, and the processor determines the second error map by subtracting a second target map and a second optical parameter map, where the second optical parameter map includes the values of the optical parameters of the second optical lens among the at least two optical lenses at multiple control points, and the second target map includes the second target values of the optical parameters at multiple control points; and / or

[0079] - The optical parameters of the first optical lens among at least two optical lenses include parameters representing the optical power of the first optical lens among at least two optical lenses at multiple control points, and / or the optical parameters of the second optical lens among at least two optical lenses include parameters representing the optical power of the second optical lens among at least two optical lenses at multiple control points; and / or

[0080] - The parameters representing the optical power of the first optical lens among at least two optical lenses at multiple control points are characterized by the average spherical lens, the average cylindrical lens, and / or the average axis position, and / or the optical power of the second optical lens among at least two optical lenses at multiple control points is characterized by the average spherical lens, the average cylindrical lens, and / or the average axis position; and / or

[0081] - The method is configured to average the first updated error map and the second updated error map by averaging the values at at least one control point of the first updated error map and the values at at least one control point of the second updated error map for at least one of the control points; and / or

[0082] - Averaging the values at at least one control point of the first updated error map and the values at at least one control point of the second updated error map is based on a weighted sum that takes into account a first quality score associated with the first updated error map and a second quality score associated with the second updated error map; and / or

[0083] - The optical lens is a single - vision lens or a progressive multifocal lens or a multifocal lens; and / or

[0084] - The distance between two control points is greater than or equal to 1 μm and less than or equal to 30 mm; and / or

[0085] - At least one surface - treatment defect in the first error map among at least two error maps includes a first surface - treatment ring and / or a first central defect, and / or wherein, at least one surface - treatment defect in the second error map among at least two error maps includes a second surface - treatment ring and / or a second central defect; and / or

[0086] - The method is configured to:

[0087] · Compare the values of the optical parameters at at least some of these control points with an optical - parameter extraction threshold, and

[0088] · Extract an updated error map from averaging the updated error maps, the updated error map having optical parameters greater than or equal to the optical - parameter extraction threshold at at least some of the control points; and / or

[0089] - The method is configured to:

[0090] · Compare the values of the optical parameters at at least some of these control points with an optical parameter correction threshold.

[0091] · Before averaging the updated error map, correct the updated error map having optical parameters greater than or equal to the optical parameter correction threshold at at least some of these control points.

[0092] The present disclosure further relates to a method for compensating for the signature of an optical lens machining process, the method comprising:

[0093] - Machine at least two optical lenses using the optical lens machining process.

[0094] - Determine the optical lens machining process signature according to the present invention, including:

[0095] · Determine

[0096] ○ At least two error maps respectively associated with at least two optical lenses machined using the optical lens machining process.

[0097] ○ At least one surface treatment defect in a first error map among the at least two error maps.

[0098] ○ At least one surface treatment defect in a second error map among the at least two error maps.

[0099] · Remove at least one surface treatment defect in the first error map among the at least two error maps from the first error map to obtain a first updated error map.

[0100] · Remove at least one surface treatment defect in the second error map among the at least two error maps from the second error map to obtain a second updated error map.

[0101] · Determine the optical lens machining process signature by averaging at least the first updated error map and the second updated error map.

[0102] - Record the optical lens machining process signature.

[0103] Wherein, the method further comprises:

[0104] - When machining a third optical lens, use the signature of the optical lens machining process to adapt the optical lens machining process such that the third optical parameter map of the third optical lens is closer to the third target map than the first optical parameter map from the first target map or the second optical parameter map from the second target map.

[0105] The third optical parameter map includes the values of the optical parameters of the third optical lens at a plurality of control points, and the third target map includes the third target values of the optical parameters at the plurality of control points.

[0106] According to additional embodiments that may be considered individually or in combination:

[0107] - The signature process is created by default by the machining process without any surprises.

[0108] - The error map is calculated as the difference between the theoretical optical parameter map and the measured optical parameter map at a plurality of control points. The theoretical optical parameter map is the optical parameter map expected at the plurality of control points after the optical lens is machined.

[0109] - The first error map among at least two error maps is associated with the first optical lens among at least two optical lenses. The first error map among at least two error maps is determined by subtracting the first target map and the first optical parameter map. The first optical parameter map includes the values of the optical parameters of the first optical lens among at least two optical lenses at a plurality of control points, and the first target map includes the first target values of the optical parameters at the plurality of control points.

[0110] - The second error map among at least two error maps is associated with the second optical lens among at least two optical lenses. The second error map is determined by subtracting the second target map and the second optical parameter map. The second optical parameter map includes the values of the optical parameters of the second optical lens among at least two optical lenses at a plurality of control points, and the second target map includes the second target values of the optical parameters at the plurality of control points; and / or

[0111] - The optical parameters of the first optical lens among at least two optical lenses include a parameter representing the refractive power of the first optical lens among at least two optical lenses at a plurality of control points, and / or the optical parameters of the second optical lens among at least two optical lenses include a parameter representing the refractive power of the second optical lens among at least two optical lenses at a plurality of control points; and / or

[0112] - The parameter representing the refractive power of the first optical lens among at least two optical lenses at a plurality of control points is characterized by the mean spherical lens, the mean cylindrical lens, and / or the mean axis position, and / or the refractive power of the second optical lens among at least two optical lenses at a plurality of control points is characterized by the mean spherical lens, the mean cylindrical lens, and / or the mean axis position; and / or

[0113] - The method is configured to average the first updated error map and the second updated error map by averaging the values at at least one control point of the first updated error map and the values at at least one control point of the second updated error map for at least one of the control points; and / or

[0114] - Averaging the values at at least one control point in the control points of the first updated error map and the values at at least one control point in the control points of the second updated error map is based on a weighted sum that takes into account a first quality score associated with the first updated error map and a second quality score associated with the second updated error map; and / or

[0115] - The optical lens is a single vision lens or a progressive multifocal lens or a multifocal lens; and / or

[0116] - The distance between two control points is greater than or equal to 1 μm and less than or equal to 30 mm; and / or

[0117] - At least one surface treatment defect in the first error map among at least two error maps includes a first surface treatment ring and / or a first central defect, and / or wherein at least one surface treatment defect in the second error map among at least two error maps includes a second surface treatment ring and / or a second central defect; and / or

[0118] - The method is configured to:

[0119] · Compare the values of the optical parameters at at least some of these control points with an optical parameter extraction threshold, and

[0120] · Extract an updated error map from averaging the updated error maps, the updated error map having optical parameters greater than or equal to the optical parameter extraction threshold at at least some of the control points; and / or

[0121] - The method is configured to:

[0122] · Compare the values of the optical parameters at at least some of these control points with an optical parameter correction threshold,

[0123] · Before averaging the updated error maps, correct the updated error maps having optical parameters greater than or equal to the optical parameter correction threshold at at least some of these control points.

[0124] This disclosure further relates to a computer program product that includes one or more sequences of stored instructions accessible by a processor, the one or more sequences of stored instructions, when executed by the processor, cause the processor to perform the steps of a method for determining a signature of an optical lens manufacturing process, the method including:

[0125] - Determine:

[0126] · At least two error maps respectively associated with at least two optical lenses machined using an optical lens manufacturing process,

[0127] ·At least one surface treatment defect in the first error map among at least two error maps,

[0128] ·At least one surface treatment defect in the second error map among at least two error maps,

[0129] -Remove at least one surface treatment defect in the first error map among at least two error maps from the first error map among at least two error maps to obtain a first updated error map,

[0130] -Remove at least one surface treatment defect in the second error map among at least two error maps from the second error map among at least two error maps to obtain a second updated error map,

[0131] -Determine the signature of the optical lens processing process by at least averaging the first updated error map and the second updated error map.

[0132] According to additional embodiments that can be considered alone or in combination:

[0133] -The signature process is created by default by the machining process without any surprises,

[0134] -The n error maps are calculated as the difference between the theoretical optical parameter map and the measured optical parameter map at multiple control points, and the theoretical optical parameter map is the optical parameter map expected at multiple control points after the optical lens is machined,

[0135] -The first error map among at least two error maps is associated with the first optical lens among at least two optical lenses, and the first error map among at least two error maps is determined by subtracting the first target map and the first optical parameter map. The first optical parameter map includes the values of the optical parameters of the first optical lens among at least two optical lenses at multiple control points, and the first target map includes the first target values of the optical parameters at multiple control points,

[0136] -The second error map among at least two error maps is associated with the second optical lens among at least two optical lenses, and the second error map is determined by subtracting the second target map and the second optical parameter map. The second optical parameter map includes the values of the optical parameters of the second optical lens among at least two optical lenses at multiple control points, and the second target map includes the second target values of the optical parameters at multiple control points; and / or

[0137] -The optical parameters of the first optical lens among at least two optical lenses include parameters representing the optical power of the first optical lens among at least two optical lenses at multiple control points, and / or the optical parameters of the second optical lens among at least two optical lenses include parameters representing the optical power of the second optical lens among at least two optical lenses at multiple control points; and / or

[0138] - The parameter representing the optical power of the first optical lens among at least two optical lenses at multiple control points is characterized by an average spherical lens, an average cylindrical lens, and / or an average axis position, and / or the optical power of the second optical lens among at least two optical lenses at multiple control points is characterized by an average spherical lens, an average cylindrical lens, and / or an average axis position; and / or

[0139] - The method is configured to average the first updated error map and the second updated error map by averaging the values at at least one control point among the control points of the first updated error map and the values at at least one control point among the control points of the second updated error map; and / or

[0140] - Averaging the values at at least one control point among the control points of the first updated error map and the values at at least one control point among the control points of the second updated error map is based on a weighted sum that takes into account a first quality score associated with the first updated error map and a second quality score associated with the second updated error map; and / or

[0141] - The optical lens is a single vision lens or a progressive multifocal lens or a multifocal lens; and / or

[0142] - The distance between two control points is greater than or equal to 1 μm and less than or equal to 30 mm; and / or

[0143] - At least one surface treatment defect in the first error map among at least two error maps includes a first surface treatment ring and / or a first central defect, and / or wherein at least one surface treatment defect in the second error map among at least two error maps includes a second surface treatment ring and / or a second central defect; and / or

[0144] - The method is configured to:

[0145] · Compare the values of the optical parameters at at least some of these control points with an optical parameter extraction threshold, and

[0146] · Extract an updated error map from the averaging of the updated error maps, the updated error map having optical parameters greater than or equal to the optical parameter extraction threshold at at least some of the control points; and / or

[0147] - The method is configured to:

[0148] · Compare the values of the optical parameters at at least some of these control points with an optical parameter correction threshold,

[0149] · Before averaging the updated error map, correct the updated error map having an optical parameter greater than or equal to an optical parameter correction threshold at at least some of these control points. BRIEF DESCRIPTION OF THE DRAWINGS

[0150] Embodiments of the present disclosure will now be described by way of example only and with reference to the following drawings, in which:

[0151] - Figure 1 illustrates a system for determining a signature of an optical lens machining process,

[0152] - Figure 2 illustrates a system for compensating for a signature of an optical lens machining process and including a system for determining a signature of an optical lens machining process,

[0153] - Figure 3 is a flowchart of a method for determining a signature of an optical lens machining process, and

[0154] - Figure 4 is a flowchart of a method for controlling an optical lens machining process.

[0155] The elements in the figures are illustrated only for simplicity and clarity and are not necessarily drawn to scale. For example, the dimensions of some elements in the figures may be enlarged relative to other elements to help improve the understanding of the embodiments of the present disclosure. DETAILED DESCRIPTION

[0156] The present disclosure relates to the field of manufacturing systems and methods for optical lenses. More precisely, the present invention relates to systems and methods for determining a signature of an optical lens machining process. The signature process is the default value of process creation without any surprises. Moreover, the present disclosure relates to systems and methods for compensating for such reproducible surface defects in the manufacturing process.

[0157] The present disclosure relates to a system for determining a signature of an optical lens machining process. According to the present disclosure, the machining process refers to the surface treatment process of an optical lens, but may refer to other types of machining.

[0158] In the context of the present disclosure, the term "optical lens" may refer to, for example, an ophthalmic lens for spectacles or an ophthalmic lens that is edged to fit a particular spectacle frame and an optical device adapted to be positioned on the optical lens. The optical device may be positioned on the front surface or the rear surface of the optical lens. The optical device may be an optical patch or an optical diaphragm. The optical device may be adapted to be removably positioned on the optical lens, for example, on a clip that is configured to clip onto a spectacle frame including the optical lens. As Figure 1 shown, the system according to the present disclosure may include:

[0159] - An input 12, which includes at least one parameter of the optical lens measured at a plurality of control points of the optical lens and is configured to be sent to the memory 14,

[0160] - A memory 14, which stores computer-executable code and is configured to store the input 12, and

[0161] - A processor 16, which is configured to execute the stored computer-executable code to generate an optical parameter map of the optical lens based on the input 12.

[0162] The memory 14 is further configured to store a first target map and a second target map. The first target map includes first target values of the optical parameters at a plurality of control points, and the second target map includes second target values of the optical parameters at a plurality of control points. In some embodiments, the first target error map and the second target error map are the same.

[0163] The processor 16 is further configured to execute the stored computer-executable code to generate an error map of the measured optical lens determined by subtracting the first target map or the second target map from the optical parameter map.

[0164] The processor 16 is further configured to determine at least one surface treatment defect in the error map.

[0165] The processor 16 is further configured to remove at least one surface treatment defect from the error map to obtain an updated error map.

[0166] The system according to the present disclosure is at least configured to:

[0167] - Determine:

[0168] · At least two error maps respectively associated with at least two optical lenses machined using an optical lens machining process,

[0169] · At least one surface treatment defect in a first error map among the at least two error maps,

[0170] · At least one surface treatment defect in a second error map among the at least two error maps,

[0171] - Remove at least one surface treatment defect in the first error map among the at least two error maps to obtain a first updated error map,

[0172] - Remove at least one surface treatment defect in the second error map among the at least two error maps to obtain a second updated error map,

[0173] -Determine the signature of the optical lens machining process by averaging at least the first updated error map and the second updated error map.

[0174] The determination of the signature of the optical lens machining process is based on the error map, which is calculated as the difference between the theoretical optical parameter map and the measured optical parameter map at a plurality of control points. The theoretical optical parameter map is the optical parameter map expected at a plurality of control points after the lens is machined.

[0175] The measurement of the optical parameters can be performed by the measuring device 12 at a plurality of control points (at least 50 control points are distributed on the lens, for example, 100 control points) on a plurality of production lenses to determine the error map of the optical lens machined using the optical lens machining process. The measured values can be any type of metric. The measured values can include surface measurements and / or optical measurements.

[0176] The measured values can include optical parameter measurements. The optical parameters can include the optical power. The optical power can include the spherical lens and / or the cylindrical lens and / or the axis position. The average power deviation of a batch of measured values is calculated according to the error deviation list. The batch can have a variable number of lenses (at least 2, for example, 100), and can be split according to any standard. The batch is defined by the standard, and these standards can include markings, hues, OPC, machines. In an embodiment, for the purpose of this disclosure, the measured optical power deviation is measured. The power deviation can be calculated by the device or by any other solution for one or several optical standards (such as spherical lens, cylindrical lens, axis position). The power of each control point can be characterized by the spherical lens value and / or the cylindrical lens value and / or the axis position value and / or the angle.

[0177] The measurement can be performed after the polishing step of the machining of the optical lens.

[0178] The surface on which the measurement is performed can be the entire surface of the optical lens (for example, a 40 mm × 40 mm square or a 40 mm diameter circle centered on the geometric center or the optical center of the optical lens) or a part of the surface of the optical lens. The measurement can be performed on several different parts of the surface of the optical lens.

[0179] According to an embodiment, the first error map among at least two error maps is associated with the first optical lens among at least two optical lenses. The first error map among at least two error maps is determined by subtracting the first target map and the first optical parameter map. The first optical parameter map includes the values of the optical parameters of the first optical lens among at least two optical lenses at a plurality of control points. The first target map includes the first target values of the optical parameters at a plurality of control points.

[0180] The second error map among at least two error maps can be associated with the second optical lens among at least two optical lenses, and then the second error map is determined by subtracting the second target map and the second optical parameter map. The second optical parameter map includes the values of the optical parameters of the second optical lens among at least two optical lenses at multiple control points, and the second target map includes the second target values of the optical parameters at multiple control points.

[0181] The optical parameters of the first optical lens among at least two optical lenses can include parameters representing the optical power of the first optical lens among at least two optical lenses at multiple control points, and / or the optical parameters of the second optical lens among at least two optical lenses include parameters representing the optical power of the second optical lens among at least two optical lenses at multiple control points.

[0182] The distance between two control points can be greater than or equal to 1 μm and less than or equal to 30 mm.

[0183] The optical power of the first optical lens among at least two optical lenses at multiple control points can be characterized by the mean spherical lens, the mean cylindrical lens, and / or the mean axis position, and / or the optical power of the second optical lens among at least two optical lenses at multiple control points is characterized by the mean spherical lens, the mean cylindrical lens, and / or the mean axis position.

[0184] The optical lens can be a single vision lens, a progressive multifocal lens, a bifocal lens, or a trifocal lens.

[0185] The lens on which the measurement is performed can be suitable for the same prescription or different prescriptions. The prescription can specify the values of one or several or all parameters necessary for constructing and / or allocating corrective lenses suitable for the lens wearer.

[0186] The lens on which the measurement is performed can be of the same type (e.g., all lenses in the batch are single vision lenses) or of different types (e.g., some lenses in the batch are single vision lenses and other lenses in the batch are progressive multifocal lenses).

[0187] Advantageously, the present disclosure allows the reliability of the same machining process to be characterized when applied to lenses of different prescriptions and / or types.

[0188] Surface treatment defect detection is completed on the error map. Then, the surface treatment defects are removed from the error map to obtain an updated error map that only includes the error deviations generated by the machining process. Advantageously, by removing the surface treatment defects from the error map, an updated error map is obtained that only contains the deviation between the machining process and the theoretical machining process. The theoretical machining process is the machining process that produces a lens such that the achieved surface measurement value is equal to the expected surface measurement value of a lens without defaults.

[0189] Surface treatment defects can include ring defects, which are typically caused by tool wear during machining. Accidental defects can include center defects, which are typically caused by tool setting during the machining process. Some existing tools (such as the Cassini tool) can be used to detect surface treatment defects, such as surface treatment rings and center defects.

[0190] Determine at least one surface treatment defect of each lens machined by an optical lens machining process. Remove at least one surface treatment defect from each of the error maps to obtain a plurality of updated error maps. At least one surface treatment defect of each lens machined by an optical lens machining process can be different.

[0191] Detecting surface treatment defects can be performed by several tests, such as detecting outliers (e.g., detecting a single outlier).

[0192] Outlier detection can be performed by several methods, such as:

[0193] - The IQR method. The IQR method calculates the lower and upper limits to identify outliers. Any value below the lower limit and above the upper limit is considered an outlier.

[0194] - The Z-score method. The Z-score is the number of standard deviations by which a variable value deviates from the variable mean.

[0195] - Distance from the mean method (multivariate method). This method calculates the Euclidean distance of data points from the mean of the data points and converts these distances to absolute z-scores. Any z-score greater than a pre-specified cut-off value is considered an outlier.

[0196] More specifically, to detect surface treatment rings, an ML model method can be performed.

[0197] The multi-layer (ML) model is a convolutional neural network (CNN) model with 8 layers, which is trained to detect surface treatment rings. The result is an evaluation of the ring strength between 0 and 1. 0 means no ring, and 1 means a very high ring.

[0198] At least one surface treatment defect in the first error map of at least two error maps can include a first surface treatment ring and / or a first center defect, and / or wherein at least one surface treatment defect in the second error map of at least two error maps includes a second surface treatment ring and / or a second center defect.

[0199] Determine the signature of the optical lens machining process by averaging a plurality of updated error maps (at least two updated error maps associated with at least two optical lenses).

[0200] To determine the signature of the optical lens manufacturing process by averaging at least a first updated error map and a second updated error map, at least some of the control points must be the same between different optical lenses. According to an embodiment, the control points are the same between different optical lenses.

[0201] The distance between two control points can be greater than or equal to 1 μm and less than or equal to 30 mm.

[0202] The system can be configured to average the first updated error map and the second updated error map by averaging the values at at least one of the control points of the first updated error map and the values at at least one of the control points of the second updated error map for at least one of these control points.

[0203] Averaging the values at at least one of the control points of the first updated error map and the values at at least one of the control points of the second updated error map can be based on a weighted sum that takes into account a first quality score associated with the first updated error map and a second quality score associated with the second updated error map. For example, the weighting can be based on the values of the optical parameters at each control point of the error map. For example, different weights can be associated with different control points of the error map when determining the quality scores.

[0204] Advantageously, the signature of the optical lens manufacturing process can be sent to a lens calculator to compensate for the manufacture of the next lens to be produced.

[0205] Advantageously, the signature of the optical lens manufacturing process can be sent to a lens calculator to generate a corrected surface, which is sent to the lens manufacturing process unit to compensate for the manufacture of the next lens to be produced.

[0206] According to an embodiment, the system is configured to:

[0207] - compare the values of the optical parameters at at least some of these control points with an optical parameter extraction threshold, and

[0208] - extract an updated error map from the averaging of the updated error maps, the updated error map having optical parameters greater than or equal to the optical parameter extraction threshold at at least some of the control points.

[0209] The control points can be associated with different thresholds. For example, the control points on the periphery of the lens can have a higher threshold. For example, the more control points there are on the periphery of the lens, the higher the threshold can be.

[0210] Advantageously, allocating different thresholds according to different regions of interest allows preventing the discarding of error maps with good specifications in more interesting regions. The more interesting regions can be defined according to the requirements of the machining process. According to an embodiment, the more interesting region is the surface excluding the periphery of the lens, for example, a 40 mm × 40 mm square centered on the optical center of the geometric center of the lens.

[0211] According to another embodiment, the system is configured to:

[0212] - Compare the values of the optical parameters at at least some of these control points with an optical parameter correction threshold, and

[0213] - Before averaging the updated error maps, correct the updated error maps having optical parameters greater than or equal to the optical parameter correction threshold at at least some of these control points.

[0214] According to this embodiment, when a surface treatment defect is detected, correction is performed by replacing the "error value" with a correction value. If the defect is on a small surface (only a few points), the correction value can be determined by averaging the measured parameter values of the points next to the defect. The correction value can also be determined by extrapolation of the surface.

[0215] The optical parameter correction value can be determined by calculating the average value of the optical parameters of the nearest neighbor control points or a larger region, which is greater than or equal to the optical parameter correction threshold, according to the surface of the control points.

[0216] Advantageously, this allows calculating as accurate an average value as possible by eliminating the values greater than or equal to the optical parameter correction threshold of adjacent control points.

[0217] No surface treatment defect may be detected in at least one error map. In this case, the signature of the optical lens machining process is determined by averaging at least one error map and other updated error maps.

[0218] This disclosure further relates to a system 18 for compensating the signature of an optical lens machining process, the system including a system for determining the signature of the optical lens machining process, the system being configured to:

[0219] - Determine

[0220] · At least two error maps respectively associated with at least two optical lenses machined using the optical lens machining process,

[0221] · At least one surface treatment defect in the first error map of the at least two error maps,

[0222] · At least one surface treatment defect in the second error map of the at least two error maps,

[0223] - Remove at least one surface treatment defect from a first error map among at least two error maps to obtain a first updated error map.

[0224] - Remove at least one surface treatment defect from a second error map among at least two error maps to obtain a second updated error map.

[0225] - Determine a signature of an optical lens machining process by at least averaging the first updated error map and the second updated error map.

[0226] Wherein, the system is further configured to use the signature of the optical lens machining process to compensate a lens machined in the next machining using the same machining process, such that an optical parameter map of the next lens is closer to its target map. In other words, when adapting the optical lens machining process for machining a third optical lens, the third optical parameter map of the third optical lens is closer to a third target map than a first optical parameter map from a first target map or a second optical parameter map from a second target map. The third optical parameter map includes values of optical parameters of the third optical lens at a plurality of control points, and the third target map includes third target values of the optical parameters at the plurality of control points.

[0227] Figure 2 System 18 for compensating a signature of an optical lens machining process and including a system for determining a signature of an optical lens machining process is shown.

[0228] Advantageously, the manufacture of the machined lens is compensated such that fewer lenses are discarded due to being too far off-specification.

[0229] Advantageously, depending on the requirements of the manufacturing process, an average can be taken for a variable number of lenses. Moreover, a new average can be performed after each manufactured lens, averaging the manufactured lens and all previously manufactured lenses in order to refine the average at each newly manufactured lens.

[0230] Other embodiments combining system 18 for compensating a signature of an optical lens machining process with one or more features of the system for determining a signature of an optical lens machining process disclosed above will be apparent to those skilled in the art after referring to the foregoing illustrative embodiments.

[0231] The present disclosure further relates to a method for determining a signature of an optical lens machining process, the method comprising:

[0232] - Determine:

[0233] · At least two error maps (step S20) respectively associated with at least two optical lenses machined during the machining process using an optical lens machining machine,

[0234] · At least one surface treatment defect in the first error map among the at least two error maps (step S22),

[0235] · At least one surface treatment defect in the second error map among the at least two error maps (step S24),

[0236] - Remove at least one surface treatment defect in the first error map among the at least two error maps to obtain a first updated error map (step S40),

[0237] - Remove at least one surface treatment defect in the second error map among the at least two error maps to obtain a second updated error map (step S42),

[0238] - Determine the signature of the optical lens machining machine's machining process by averaging at least the first updated error map and the second updated error map (step S60).

[0239] Figure 3 The flowchart of the method for determining the signature of the optical lens machining machine's machining process is shown.

[0240] No surface treatment defect may be detected in at least one of the error map determination steps S22 and S24. In this case, the signature of the optical lens machining machine's machining process is determined by averaging at least one error map and other updated error maps.

[0241] Advantageously, this method allows the characterization of the reliability of the machining process.

[0242] The lenses on which the measurements are performed can have the same prescription or different prescriptions.

[0243] The lenses on which the measurements are performed can be of the same type (e.g., all lenses in the batch are single - vision lenses) or of different types (e.g., some lenses in the batch are single - vision lenses and other lenses in the batch are progressive multifocal lenses).

[0244] Advantageously, this method allows the characterization of the reliability of the same machining process when applied to lenses with different prescriptions and / or types.

[0245] Other embodiments combining the method for determining the signature of the optical lens machining machine's machining process with one or more features of the system for determining the signature of the optical lens machining machine disclosed above will be apparent to those skilled in the art after referring to the foregoing illustrative embodiments.

[0246] This disclosure further relates to a method for controlling the machining process of an optical lens machine, the method comprising:

[0247] - machining an optical lens using the machining process of the optical lens machine (step 100),

[0248] - determining a machining process signature of the optical lens machine (step 200), including:

[0249] · determining

[0250] · at least two error maps respectively associated with at least two optical lenses machined using the machining process of the optical lens machine (step 220)

[0251] ○ at least one surface treatment defect in the first error map of the at least two error maps (step 222),

[0252] ○ at least one surface treatment defect in the second error map of the at least two error maps (step 224),

[0253] · removing at least one surface treatment defect in the first error map of the at least two error maps from the first error map to obtain a first updated error map (step 240),

[0254] · removing at least one surface treatment defect in the second error map of the at least two error maps from the second error map to obtain a second updated error map (step 242),

[0255] · determining the machining process signature of the optical lens machine by averaging at least the first updated error map and the second updated error map (step 260).

[0256] - recording the machining process signature of the optical lens machine (step 300),

[0257] wherein, the method further comprises:

[0258] using the signature of the machining process of the optical lens machine to compensate the next lens machined using the same machining process, such that the optical parameter map of the next lens is closer to its target map. In other words, when machining a third optical lens, adapting the machining process of the optical lens machine such that the third optical parameter map of the third optical lens is closer to the third target map than the first optical parameter map from the first target map or the second optical parameter map from the second target map, the third optical parameter map includes the values of the optical parameters of the third optical lens at a plurality of control points, and the third target map includes the third target values of the optical parameters at a plurality of control points.

[0259] In other words, the method further comprises:

[0260] Periodically repeat the steps of optical lens processing machine processing, determining and recording the signature of the optical lens processing machine processing process, and examining the evolution of the signature of the optical lens processing machine processing process over time (step 400),

[0261] - Examine the evolution of at least one parameter of the machining device used in the optical lens processing machine processing process over time (step 500), and

[0262] - Correlate the evolution of the signature of the optical lens processing machine processing process over time with the evolution of at least one parameter of the machining device over time (step 600).

[0263] Figure 4 A flowchart of a method for controlling an optical lens processing machine processing process is shown therein.

[0264] Surface treatment defects may not be detected in at least one of the error map determination steps S222 and S224. In this case, the signature of the optical lens processing machine processing process is determined by averaging at least one error map and other updated error maps.

[0265] Advantageously, periodically repeating the determination of the signature of the optical lens processing machine processing process allows for refining the average over time, examining the evolution of the machining process, and compensating the next machined lens using the same machining process so that the optical parameter map of the next lens is closer to its target map. In other words, when machining the third optical lens, the optical lens processing machine processing process is adapted such that the third optical parameter map of the third optical lens is closer to the third target map than the first optical parameter map from the first target map or the second optical parameter map from the second target map, the third optical parameter map including the values of the optical parameters of the third optical lens at a plurality of control points, and the third target map including the third target values of the optical parameters at the plurality of control points.

[0266] Advantageously, the manufacture of the machined lens is compensated such that fewer lenses are discarded due to being too far from the specifications.

[0267] Advantageously, examining the evolution of the machining process over time allows predicting the service life of the machining process. Moreover, it allows for issuing an alarm in the case of a refractive power shift of the equipment.

[0268] Other embodiments combining the method for controlling an optical lens processing machine processing process with one or more features of the system for determining the signature of an optical lens processing machine processing process disclosed above will be apparent to those skilled in the art after referring to the foregoing illustrative embodiments.

[0269] This disclosure further relates to a computer program product comprising one or more sequences of stored instructions accessible by a processor, the one or more sequences of stored instructions, when executed by the processor, causing the processor to perform the steps of a method for determining a signature of an optical lens machining process, the method comprising:

[0270] - determining:

[0271] · at least two error maps respectively associated with at least two optical lenses machined using an optical lens machining process,

[0272] · at least one surface treatment defect in a first error map of the at least two error maps,

[0273] · at least one surface treatment defect in a second error map of the at least two error maps,

[0274] - removing at least one surface treatment defect in the first error map of the at least two error maps from the first error map of the at least two error maps to obtain a first updated error map,

[0275] - removing at least one surface treatment defect in the second error map of the at least two error maps from the second error map of the at least two error maps to obtain a second updated error map,

[0276] - determining the signature of the optical lens machining process by at least averaging the first updated error map and the second updated error map.

[0277] This disclosure further relates to a computer-readable medium carrying one or more sequences of instructions of the computer program product as disclosed hereinabove.

[0278] Other embodiments combining the computer program product with one or more features of the system for determining a signature of an optical lens machining process as disclosed hereinabove will be apparent to those skilled in the art after reference to the foregoing illustrative embodiments.

[0279] It will be apparent from the following discussion that, unless specifically stated otherwise, it should be appreciated that throughout the specification, discussions using terms such as "operating", "computing", "generating", etc. refer to the actions and / or processes of a computer or computing system or similar electronic computing device that manipulate and / or transform data represented as physical (such as electronic) quantities within the registers and / or memories of the computing system into other data similarly represented as physical quantities within the memories, registers, or other such information storage, transmission, or display devices of the computing system.

[0280] Embodiments of the present disclosure may include apparatuses for performing the operations herein. The apparatus may be specially constructed for the desired purposes, or the apparatus may comprise a general-purpose computer or a digital signal processor ("DSP") selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a computer-readable storage medium, such as, but not limited to, any type of disk, including floppy disks, optical disks, CD-ROMs, magneto-optical disks, read-only memory ("ROM"), random access memory ("RAM"), electrically programmable read-only memory ("EPROM"), electrically erasable programmable read-only memory ("EEPROM"), magnetic or optical cards, or any other type of medium suitable for storing electronic instructions and capable of being coupled to a computer system bus.

[0281] The processes and displays presented herein are not inherently related to any particular computer or other apparatus. Various general-purpose systems may be used with programs in accordance with the teachings herein, or it may prove convenient to construct more specialized apparatus to perform the desired method. The desired construction of various such systems will become apparent from the following description. Additionally, embodiments of the present disclosure have been described without reference to any particular programming language. It will be appreciated that a variety of programming languages may be used to implement the teachings of the present disclosure as described herein.

[0282] Many further modifications and variations will be apparent to those skilled in the art in reference to the foregoing illustrative embodiments, which are given by way of example only and are not intended to limit the scope of the present disclosure, the scope of which is determined only by the appended claims.

[0283] In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that different features are recited in mutually different dependent claims does not indicate that a combination of these features cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope of the present disclosure.

Claims

1. A system for determining a signature of an optical lens processing process, the system being configured to: - Determine: · At least two error maps respectively associated with at least two optical lenses machined using the optical lens processing process, · At least one surface treatment defect in a first error map of the at least two error maps, · At least one surface treatment defect in a second error map of the at least two error maps, - Remove the at least one surface treatment defect in the first error map of the at least two error maps from the first error map of the at least two error maps to obtain a first updated error map, - Remove the at least one surface treatment defect in the second error map of the at least two error maps from the second error map of the at least two error maps to obtain a second updated error map, - Determine the signature of the optical lens processing process by at least averaging the first updated error map and the second updated error map.

2. The system according to claim 1, wherein: - The first error map of the at least two error maps is associated with a first optical lens of the at least two optical lenses, and the first error map of the at least two error maps is determined by subtracting a first target map and a first optical parameter map, the first optical parameter map including values of optical parameters of the first optical lens of the at least two optical lenses at a plurality of control points, the first target map including first target values of the optical parameters at the plurality of control points, - The second error map of the at least two error maps is associated with a second optical lens of the at least two optical lenses, and the second error map is determined by subtracting a second target map and a second optical parameter map, the second optical parameter map including values of optical parameters of the second optical lens of the at least two optical lenses at the plurality of control points, the second target map including second target values of the optical parameters at the plurality of control points.

3. The system according to claim 2, wherein, The optical parameters of the first optical lens of the at least two optical lenses include parameters representing the optical power of the first optical lens of the at least two optical lenses at the plurality of control points, and / or the optical parameters of the second optical lens of the at least two optical lenses include parameters representing the optical power of the second optical lens of the at least two optical lenses at the plurality of control points.

4. The system according to claim 3, wherein, The parameters representing the optical power of the first optical lens of the at least two optical lenses at the plurality of control points are characterized by an average spherical lens, an average cylindrical lens, and / or an average axis position, and / or the optical power of the second optical lens of the at least two optical lenses at the plurality of control points is characterized by an average spherical lens, an average cylindrical lens, and / or an average axis position.

5. The system according to any one of the preceding claims, wherein, The system is configured to average the first updated error map and the second updated error map by averaging values at at least one control point of the control points of the first updated error map and values at at least one control point of the control points of the second updated error map for at least one of the control points.

6. The system according to the previous claim, wherein, Averaging values at at least one control point of the control points of the first updated error map and values at at least one control point of the control points of the second updated error map is based on a weighted sum that takes into account a first quality score associated with the first updated error map and a second quality score associated with the second updated error map.

7. The system according to any one of the preceding claims, wherein The optical lens is a single vision lens or a progressive multifocal lens or a multifocal lens.

8. The system according to any one of the preceding claims, wherein, The distance between the two control points is greater than or equal to 1 μm and less than or equal to 30 mm.

9. The system according to any one of the preceding claims, wherein, At least one surface treatment defect in the first error map of the at least two error maps includes a first surface treatment ring and / or a first central defect, and / or wherein at least one surface treatment defect in the second error map of the at least two error maps includes a second surface treatment ring and / or a second central defect.

10. The system according to any one of the preceding claims, wherein, The system is configured to: - Compare values of optical parameters at at least some of the control points with an optical parameter extraction threshold, and - Extract the updated error map from averaging the updated error maps, the updated error map having optical parameters greater than or equal to the optical parameter extraction threshold at at least some of the control points.

11. The system according to any one of the preceding claims, wherein, The system is configured to: - Compare values of optical parameters at at least some of the control points with an optical parameter correction threshold, and - Before averaging the updated error maps, correct the updated error maps having optical parameters greater than or equal to the optical parameter correction threshold at at least some of the control points.

12. A system for compensating for the signature of an optical lens manufacturing process, the system being configured to: - Determine · At least two error maps respectively associated with at least two optical lenses machined using the optical lens manufacturing process, · At least one surface treatment defect in the first error map of the at least two error maps, · At least one surface treatment defect in the second error map of the at least two error maps, - Remove at least one surface treatment defect in the first error map of the at least two error maps from the first error map to obtain a first updated error map, - Remove at least one surface treatment defect in the second error map of the at least two error maps from the second error map to obtain a second updated error map, - Determine the signature of the optical lens manufacturing process by at least averaging the first updated error map and the second updated error map Among them, The system is further configured to adapt the optical lens machining process using the signature of the optical lens machining process when machining a third optical lens, such that a third optical parameter map of the third optical lens is closer to a third target map than a first optical parameter map from the first target map or a second optical parameter map from the second target map. The third optical parameter map includes values of optical parameters of the third optical lens at the plurality of control points, and the third target map includes third target values of optical parameters at the plurality of control points.

13. A method for determining a signature of an optical lens machining process, the method comprising: - Determining: · At least two error maps respectively associated with at least two optical lenses machined using the optical lens machining process, · At least one surface treatment defect in a first error map of the at least two error maps, · At least one surface treatment defect in a second error map of the at least two error maps, - Removing at least one surface treatment defect in the first error map of the at least two error maps from the first error map of the at least two error maps to obtain a first updated error map, - Removing at least one surface treatment defect in the second error map of the at least two error maps from the second error map of the at least two error maps to obtain a second updated error map, - Determining the signature of the optical lens machining process by at least averaging the first updated error map and the second updated error map.

14. A method for compensating a signature of an optical lens machining process, the method comprising: - Using the optical lens machining process to machine at least two optical lenses, - Determining that the signature of the optical lens machining process includes: · Determining ○ At least two error maps respectively associated with the at least two optical lenses machined using the optical lens machining process, ○ At least one surface treatment defect in a first error map of the at least two error maps, ○ At least one surface treatment defect in a second error map of the at least two error maps, · Removing at least one surface treatment defect in the first error map of the at least two error maps from the first error map of the at least two error maps to obtain a first updated error map, · Removing at least one surface treatment defect in the second error map of the at least two error maps from the second error map of the at least two error maps to obtain a second updated error map, · Determining the signature of the optical lens machining process by at least averaging the first updated error map and the second updated error map, - Recording the signature of the optical lens machining process, wherein the method further comprises: - When machining the third optical lens, use the signature of the optical lens machining process to adapt the optical lens machining process such that the third optical parameter map of the third optical lens is closer to the third target map than the first optical parameter map from the first target map or the second optical parameter map from the second target map. The third optical parameter map includes the values of the optical parameters of the third optical lens at the plurality of control points, and the third target map includes the third target values of the optical parameters at the plurality of control points.

15. A computer program product, the computer program product comprising one or more stored sequences of instructions, the one or more sequences of instructions being accessible by a processor and, when executed by the processor, causing the processor to perform the steps of a method for determining the signature of an optical lens machining process, the method comprising: - Determine: · At least two error maps respectively associated with at least two optical lenses machined using the optical lens machining process, · At least one surface treatment defect in the first error map of the at least two error maps, · At least one surface treatment defect in the second error map of the at least two error maps, - Remove at least one surface treatment defect in the first error map of the at least two error maps from the first error map of the at least two error maps to obtain a first updated error map, - Remove at least one surface treatment defect in the second error map of the at least two error maps from the second error map of the at least two error maps to obtain a second updated error map, - Determine the signature of the optical lens machining process by at least averaging the first updated error map and the second updated error map.

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