[0001] The invention relates to the field of industrial surfacing processes to manufacture
ophthalmic lenses.
[0002] The invention relates more particularly to a method of optimizing the shape of the
periphery that the surfacing of a lens blank destined to be transformed into the final
lens is to convey to the lens blank thereafter.
[0003] In general, a spectacle lens is specifically manufactured according to every wearer's
needs which may take the form of specifications defined in a prescription established
by an ophthalmologist.
[0004] For the manufacturing of a lens, a lens blank is submitted to various steps to form
the desired lens, in particular one of surfacing during which the shape of the lens
blank is processed to produce what can be referred to as a surfaced lens so that the
latter exhibits desired optical properties.
[0005] In practice, such as an operation is often carried out on a semi-finished lens blank
whose front surface has previously been processed, the operation of surfacing essentially
impacting one of the surfaces of the lens blank, typically the back surface, according
to the prescription.
[0006] In the context of the invention, the surfacing step includes processing the lens
blank to reduce its outer shape to a shape which is typically (although not necessarily)
round, exhibiting a chosen diameter, or crib diameter. This operation is usually performed
so that the resulting surfaced lens may then be more easily held during following
steps, which typically include one during which the lens is immersed in a coating
fluid while it is held by a device such as a ring.
[0007] The document
WO 2006/084771 A1 concerns a method for manufacturing a spectacle lens, and more specifically methods
for eliminating sharp edges that typically result during the production of uncut lenses.
The crib diameter is firstly defined as a two parameters-function depending on a blocking
location. A step of blocking is performed during the method of manufacturing the spectacle
lens to block the lens blank with a holding block. This holding block allows handling
the lens blank during the various production steps, while a circular disk of bonding
alloy is formed between the lens blank and a holding block to attach the lens blank
to the holding block prior to cribbing, cutting, or surfacing. Yet, this process of
cribbing is subject to various constraints, which can easily translate into an extremely
varied population of potential crib diameters which result therefrom.
[0008] This is undesirable, as this tends to require that the manufacturing process be adjusted
to the lens being manufactured, in particular in terms of equipment used to hold the
lens which has been cribbed, e.g. for the coating thereof.
[0009] The invention seeks to improve this situation.
[0010] To this end, the invention relates to a method of preparing a lens blank for a further
operation of surfacing of said lens blank configured to transform the lens blank into
a surfaced lens at the end thereof for further transformation into a lens having a
lens shape and destined to be coupled to a frame, the operation of surfacing including
processing the lens blank so that the surfaced lens exhibits a crib diameter, the
method being implemented using a processing module and comprising :
- based on input data which define the lens shape, defining a temporary crib diameter
so that said temporary crib diameter satisfies a set of constraints which includes
at least:
- a first constraint whereby the temporary crib diameter is large enough for the surfaced
lens having said temporary crib diameter to be suitable to be processed into said
lens ,
- a second constraint whereby the temporary crib diameter is large enough for the surfaced
lens having said temporary crib diameter to include a plurality of reference points
defined on the lens blank and which together identify an optical center of the lens,
- choosing the crib diameter as a function of the temporary crib diameter, said choosing
the crib diameter being configured so that, when a step cribbing configuration is
destined to be applied to the operation of surfacing, said crib diameter is chosen
among at least one predetermined discrete value.
[0011] According to an aspect of the invention, the crib diameter is chosen as corresponding
to the smallest discrete value which is superior to the temporary crib diameter.
[0012] According to an aspect of the invention, the method further comprises, when a surface
extension configuration is destined to be applied to the operation of surfacing, generating
a surface file to be used during the operation of surfacing for generating the lens
shape so that the lens shape is circular with a diameter corresponding to the crib
diameter.
[0013] According to an aspect of the invention, said one or more predetermined discrete
value is formed by a single value.
[0014] According to an aspect of the invention, the temporary crib diameter is chosen as
the smallest value which satisfies said set of constraints.
[0015] According to an aspect of the invention, the set of constraints includes a third
constraint according to which the temporary crib diameter is superior or equal to
a minimum crib diameter of an apparatus destined to be used to reduce the diameter
of the lens blank during the operation of surfacing.
[0016] According to an aspect of the invention, for satisfying the first constraint, the
temporary crib diameter is taken as superior or equal to a lens shape parameter defined
based on twice a maximum radius of the lens shape.
[0017] According to an aspect of the invention, the lens shape parameter is taken equal
as twice the radius of the lens shape when the generated lens shape is circular.
[0018] According to an aspect of the invention, the lens shape parameter is taken equal
as twice the sum of the maximum radius and of a margin defined based on a shape of
the frame the lens is destined to be coupled to.
[0019] According to an aspect of the invention, for satisfying the second constraint, the
temporary crib diameter is chosen superior or equal to a reference parameter defined
based on twice a distance between a center of the lens shape in a blocking and turning
referential of the lens blank during the operation of surfacing and the reference
point of the lens blank which is the farthest away from said center.
[0020] According to an aspect of the invention, the reference parameter is taken equal to
twice the sum of said distance and of a predetermined margin.
[0021] The invention also relates to a computer program comprising instructions destined
to be executed by a processor for the implementation of the method as defined above.
[0022] The invention also relates to a method of surfacing a lens blank configured to transform
the lens blank into a surfaced lens at the end thereof for further transformation
into a lens having a lens shape and destined to be coupled to a frame, the method
comprising:
- preparing the lens blank for surfacing using a method of preparing a lens blank as
defined above to obtain a crib diameter, and
- surfacing the lens blank, said surfacing the lens blank including processing the lens
blank so that the surfaced lens exhibits the crib diameter.
[0023] The invention also relates to a device for preparing a lens blank for a further operation
of surfacing of said lens blank configured to transform the lens blank into a surfaced
lens having a lens shape at the end thereof for further transformation into a lens
to be coupled to a frame, the operation of surfacing including processing the lens
blank so that the surfaced lens exhibits a crib diameter, the device comprising a
processing module configured to:
- based on input data which define the lens shape, define a temporary crib diameter
so that said temporary crib diameter satisfies a set of constraints which includes
at least:
- a first constraint whereby the temporary crib diameter is large enough for the surfaced
lens having said temporary crib diameter to be suitable to be processed into said
lens,
- a second constraint whereby the temporary crib diameter is large enough for the surfaced
lens having said temporary crib diameter to include a plurality of reference points
defined on the lens blank and which together identify an optical center of the lens,
- choose the crib diameter as a function of the temporary crib diameter, the processing
module being configured to choose the crib diameter so that, in response to a step
cribbing configuration being destined to be applied to the operation of surfacing,
said crib diameter is chosen among at least one predetermined discrete value.
[0024] Other features and advantages of the invention will become apparent from the following
description provided for indicative and non-limiting purposes, with reference to the
accompanying drawings, wherein:
- Figure 1 illustrates a lens blank, a surfaced lens and a finished lens;
- Figure 2 illustrated a system according to the invention;
- Figure 3 illustrates schematically a method of manufacturing a lens according to the
invention; and
- Figure 4 illustrates steps of a preparation step of the method of Figure 3.
[0025] Figure 1 illustrates a lens blank BLA which is used in the context of the invention with a
view of manufacturing an ophthalmic lens, or finished lens, LEN designed to exhibit
optical properties. In particular, the lens LEN which is obtained advantageously presents
eyesight correction properties which address eyesight issues of its intended wearer.
The lens LEN is typically designed to be coupled to a frame (now shown) to define
spectacles therewith which are to be worn by the wearer.
[0026] To obtain the lens LEN, the lens blank BLA which is designed to be processed into
the resulting lens is put through a series of operations whose general respective
principles are typically known.
[0027] One of these operations, on which the invention focuses, is one of surfacing the
lens blank to produce a surfaced lens SLE therefrom which is itself to be put through
further operations to produce the lens LEN. It should be noted that the surfaced lens
LEN advantageously exhibits the target optical properties of the lens LEN.
[0028] Advantageously, the lens blank BLA which is used during this step is a semi-finished
lens bank. In other words, one of its surfaces has already been processed to a desired
shape. Typically, the front surface is thus already processed when the surfacing operation
is to take place, only the back surface being then processed. Regardless of whether
the lens bank is of the semi-finished type thereafter, the term "lens blank" is to
be understood as encompassing configurations in which the lens blank is semi-finished,
and configurations in which it is not, although the configurations in which it is
are preferred.
[0029] As for the details of the operation of surfacing, the step generally revolves around
some of the matter of the lens blank being removed therefrom so as to shape the lens
blank BLA into the surfaced lens LEN.
[0030] In particular, in the sense of the invention, this operation includes a step of cribbing
the lens blank BLA, which corresponds to a step during which the external shape of
the lens blank is reduced in terms of dimensions to a diameter which is referred to
as a crib diameter D
crib.
[0031] In effect, the step of cribbing results in the surfaced lens SLE having an external
shape which may be circular or not. When it is not round, the term "diameter" is to
be understood as referring to the maximal diameter unless specified otherwise.
[0032] This external shape is destined to come in contact with a piece of equipment during
a further step of the process, typically one of coating the surfaced lens. For instance,
the external shape of the surfaced lens is held by a ring used to immerse the surfaced
lens in a coating material.
[0033] Figure 2 illustrates a system SYS according to the invention, the system SYS being configured
to be used during the operation of surfacing in general to shape the lens blank BLA
into the surfaced lens SLE.
[0034] The system SYS includes a generator GEN which is adapted to be used during the surface
per se to remove matter from the lens blank BLA to shape the latter into the surfaced lens
SLE. In addition, the system SYS includes an apparatus APP adapted to prepare at least
in part the surfacing of the lens blank BLA
per se. More specifically, as detailed below, the apparatus APP is configured to determine
the crib diameter noted D
crib hereafter, which is applied to the lens blank BLA during the operation of surfacing.
[0035] Regarding the generator GEN, it advantageously includes a grinding module GRIN and/or
a cutting module CUT which are respectively configured to remove some of the matter
of the lens blank BLA to shape the lens blank BLA into the generated lens LEN through
grinding, respectively cutting.
[0036] For instance, the grinding module and the cutting module are movable relative to
a body of the generator by which the lens blank BLA is held.
[0037] For instance, to that end, the lens blank BLA is secured to a support which is held
by the generator. Advantageously, the lens blank BLA is held in a manner which advantageously
allows the lens blank to be moved relative to the body of the generator, typically
to rotate relative thereto.
[0038] Regarding the apparatus APP, as indicated above, it is configured to prepare the
operation of surfacing of the lens blank, and in particular to determine the cribbing
diameter to which the lens blank BLA is brought during this operation.
[0039] In a general sense, the apparatus APP may be a stand-alone apparatus specifically
dedicated to the preparation of the surfacing.
[0040] Alternatively, it may be combined with one or more other apparatus destined to be
used during the manufacturing of ophthalmic lenses, such as the generator itself.
[0041] As illustrated on Figure 2, the apparatus APP is a computer device. It includes a
processing module PROC, a memory MEM, a communication interface COM, and a human-machine
interface HMI.
[0042] The processing module PROC is configured to carry out the method of preparing a lens
blank BLA in the sense of the invention, which is detailed hereafter.
[0043] The processing module PROC includes one or more processor CPU which is configured
to process instructions for the implementation of the method according to the invention.
[0044] This processor may be of any known type.
[0045] The memory MEM is configured to store computer programs and data which are destined
to be processed by the processing module PROC for the operations of the apparatus
APP. Typically, it may include one or more programs defining an operating system via
which the apparatus performs routine operations. Advantageously, it also includes
a computer program PRG comprising instructions destined to be executed by the processing
module MOD for the implementation of the method according to the invention detailed
below.
[0046] As for the data, in the context of the invention, they include input data ID which
are configured to describe the shape of the lens LEN, or lens shape, which is to be
obtained at the end of the manufacturing process.
[0047] It should be noted that this lens shape is to be distinguished from the shape of
the surfaced lens SLE, or surfaced lens shape, which is that of the result of the
processing of the lens blank BLA through the surfacing of the latter.
[0048] On a specific level, the input data ID may advantageously include a model of the
lens, i.e. of the manufactured lens. Advantageously, this model is expressed in a
blocking/turning referential of the lens, i.e. a referential which uses the center
of rotation of the lens blank during the surfacing as its origin and with one or more
of its axis corresponding to an axis of rotation of the lens blank during the surfacing.
[0049] For instance, the model includes a model of the front surface and back surface of
the lens, as well as kinematics between these two surfaces.
[0050] Advantageously, the input data ID also include data which describe the lens shape,
i.e. the shape of the manufactured lens LEN. For instance, these data include the
traced shape of the lens for the wearer.
[0051] .Optionally, they also include a diameter information. For instance, this is so when
the optical properties of the lens call for a diameter which is considered untypical.
[0052] The memory MEM may also contain configuration data CFGD which define preferences
for the operation of surfacing which is to occur following the preparation.
[0053] The configuration data CFGD advantageously include a frame shape margin M
FS whose value is predetermined. This frame shape margin corresponds to a margin which
is provided for the surfaced lens SLE to ensure a good cooperation between the lens
LEN and the frame FRA once the lens has been further processed.
[0054] The configuration data CFGD advantageously include a step cribbing parameter which
defines whether a step cribbing configuration is enabled for the surfacing, whereby
the crib diameter D
crib is chosen among at least one predetermined discrete value Val
i. It should be noted that there may be a single discrete value.
[0055] The configuration data CFGD advantageously include a list of preferred diameters.
For instance, these preferred diameters correspond to the discrete values Val
i among which the crib diameter is chosen.
[0056] The configuration data CFGD advantageously include a Minimum Generator Crib Diameter,
noted MinGen, which corresponds to a minimum crib diameter that the generator GEN
is adapted to provide.
[0057] The configuration data CFGD advantageously include a surface extension parameter
which describes whether a surface extension configuration is enabled for the surfacing,
whereby the surfaced lens has a shape which is purposefully extended to be circular.
[0058] The data contained in the memory MEM advantageously also include reference data REFD
which define the location of reference points P
REF defined on the lens blank and which together identify an optical center of the lens
LEN.
[0059] The location of the references points is for instance expressed in a given referential,
such as the PRP referential, for Prism Reference Point referential. The Prism Reference
Point corresponds to the optical center of the lens. This referential includes three
axis passing through the Prism Reference Point, for instance a horizontal axis, a
vertical axis, and one passing through the lens and normal to the front surface of
the lens. This referential may correspond to the blocking/turning referential.
[0060] The reference points P
REF may take the form of circles, such as microcircles.
[0061] The human-machine interface HMI is adapted to allow an operator to input data into
the apparatus APP and/or to display data for the operator.
[0062] The data in question may be any data, in particular that contained in the memory
which form all or part of the configuration data CFGD, the input data ID or the reference
data REFD.
[0063] The human-machine interface HMI may include an input device, such as a keyboard,
a mouse, and the like. The input device may also include a screen, optionally combined
with the mouse and/or the keyboard to define a touch sensitive screen.
[0064] As for the communication interface COM, it is adapted for communication between the
apparatus APP and one or more distant device.
[0065] Any cable and/or non-cable communication technology may be supported by the communication
module COMM.
[0066] A method of manufacturing a lens LEN (shown by a dashed line on Figure 1) from a
lens blank BLA according to the invention will now be described in reference to the
Figures, including
Figure 4.
[0067] In reference to
Figure 3, i in a general sense, and as discussed above, the manufacturing includes a step
of surfacing a lens blank BLA into a surfaced lens SLE during a step S1.
[0068] The process also includes further processing of the surfaced lens SLE into the desired
lens LEN during a step S2. This further processing is not the core aspect of the invention,
and will therefore not be discussed in more details. In effect, any known technique
may be applied to that end.
[0069] As for step S1, it includes the preparation noted PREP of the surfacing of the lens
blank BLA, and the surfacing noted SURF of the lens blank BLA
per se.
[0070] Regarding the preparation PREP, as discussed, its goal, or one of its goals, is the
determination of the crib diameter D
crib which is conveyed to the surfaced lens SLE during the surfacing SURF. It is carried
out by the apparatus APP, and in particular by the processing module PROC using the
memory MEM.
[0071] In a general sense, this determination relies on defining a temporary crib diameter
D
temp which satisfies a set of constraints, and choosing the crib diameter D
crib based on the temporary crib diameter D
temp so that when the step cribbing configuration is destined to be applied to the operation
of surfacing SURF, the crib diameter D
crib is chosen among at least one predetermined discrete value.
[0072] The set of constraints includes at least one constraint, and advantageously a plurality
of constraints.
[0073] Advantageously, it includes a first constraint whereby the temporary crib diameter
D
temp is large enough for the surfaced lens SLE having said temporary crib diameter to
be suitable to be processed into said lens. In other words, the temporary crib diameter
D
temp is chosen so that if the surfaced lens shape were to have this temporary crib diameter,
obtaining the lens from the surfaced lens would be possible.
[0074] The temporary crib diameter D
temp is determined to verify this first constraint during a step T1.
[0075] To that end, the temporary crib diameter D
temp is taken as superior or equal to a lens shape parameter defined based on twice a
maximum radius of the lens shape.
[0076] In more details, based on the input data ID and the lens shape defined therein, it
is determined whether the lens shape is round or not.
[0077] If it is, the lens shape parameter, and therefore the temporary crib diameter D
temp, is set to twice the radius of the lens shape, which also corresponds to its maximum
radius.
[0078] If the lens LEN is not round, the lens shape parameter is set to twice the sum of
the maximum radius of the lens shape and of the frame shape margin M
FS. This margin is indeed chosen based on the shape of the frame the lens is destined
to be coupled to. Typically, this margin is designed to ensure that the cribbing diameter
will not come too close to the final lens shape, thus avoiding any lack of material
inside the frame.
[0079] The set of constraints advantageously comprises a second constraint whereby the temporary
crib diameter D
temp is large enough for the surfaced lens having said temporary crib diameter to include
the plurality of reference points P
REF. In other words, the constraint aims to ensure that the reference points are not
removed from the lens blank while the latter is cribbed.
[0080] The temporary crib diameter D
temp is determined to verify the second constraint during a step T2.
[0081] In details, during this step T2, the temporary crib diameter D
temp is chosen superior or equal to a reference parameter defined based on twice a distance
between the center of the lens shape in the blocking/turning turning referential of
the lens blank during the operation of surfacing and the reference point of the lens
blank which is the farthest away from said center. In effect, for each reference point,
the distance between this center and the reference point is determined, the obtained
distance is summed to a margin distance, and the highest value obtained among the
various reference points, noted Rmc for instance, is chosen as the reference parameter.
This margin distance is for instance chosen as 1 mm.
[0082] Then, it is determined whether the current temporary crib diameter D
temp is inferior to twice the value Rmc.
[0083] If so, the temporary crib diameter D
temp is set to twice the value of Rmc.
[0084] If not, the current temporary crib diameter D
temp is kept.
[0085] Advantageously, the set of constraints includes a third constraint according to which
the temporary crib diameter is superior or equal to the minimum generator crib diameter
MinGen. In other words, this constraint aims to ensure that the crib diameter is realistic
in view of the limitations of the generator GEN.
[0086] The temporary crib diameter D
temp is determined so as to verify the third constraint during a step T3.
[0087] During this step, it is determined whether the current temporary crib diameter D
temp is inferior to the minimum generator crib diameter MinGen.
[0088] If so, the current temporary crib diameter D
temp is set to the minimum generator crib diameter MinGen.
[0089] If not, the current temporary crib diameter D
temp is kept.
[0090] Indeed, the steps T1 to T3 may be implemented in any order. The temporary crib diameter
D
temp is advantageously set to zero prior to the first of these steps. In effect, through
these steps, the temporary crib diameter D
temp is advantageously chosen as the smallest value which satisfies the set of constraints.
[0091] During a step T4, which preferably takes places after the steps T1 to T3, it is determined
whether the step cribbing configuration is enabled for the surfacing SURF. This operation
is carried out based on the configuration data CFGD.
[0092] In practice, the step cribbing parameter is analyzed to see whether this is the case
or not.
[0093] If the step cribbing configuration is not enabled for the surfacing SURF, the crib
diameter D
crib is chosen based on the current temporary crib diameter D
temp. Advantageously, it is taken equal to the current temporary crib diameter D
temp.
[0094] If the step cribbing configuration is enabled, then it is determined whether the
preferred diameters contained in the configuration data CFGD comprise at least one
preferred diameter which is superior to the current temporary crib diameter D
temp.
[0095] If they contain such a diameter, the current temporary crib diameter D
temp is set to a value chosen among these values. Advantageously, it is then taken equal
to the smallest preferred diameter which is superior to the current temporary crib
diameter D
temp.
[0096] If the preferred diameters do not contain a diameter which is superior to the current
temporary crib diameter, the current temporary crib diameter D
temp is kept.
[0097] The crib diameter D
crib is then chosen based on the temporary crib diameter D
temp. Advantageously, it is taken equal to the temporary crib diameter D
temp.
[0098] In effect, at the end of step S4, the crib diameter D
crib has a given value, which forms the final value of the crib diameter.
[0099] During an optional step T5, which is preferably implemented after step T4, it is
then determined whether the surface extension configuration is enabled for the surfacing
SURF.
[0100] If so, a surface file is generated. This surface file contains a definition of the
shape of the surfaced lens. It is destined to be used during the operation of surfacing
SURF for generating the shape of the surfaced lens shape so that the shape of the
surfaced lens is circular with a diameter corresponding to the crib diameter. Typically,
this surface file is destined to be used as input by the generator to determine the
details of the processing of the lens blank BLA.
[0101] In other words, when the surface extension is activated, this step includes the generation
of instructions destined to the generator GEN so that the shape of the surfaced lens
is to be brought to a circular shape having the crib diameter D
crib during the surfacing SURF, whereby this shape can be seen as extended relative to
a configuration in which the surface extension configuration is not enabled.
[0102] If the surface extension configuration is not enabled, then the process stops.
[0103] After this step, whether prior to step T5 or not, the crib diameter D
crib is output by the apparatus for the generator GEN to use as input for the surfacing
SURF which takes place thereafter.
[0104] The surfacing SURF advantageously uses the crib diameter D
crib to process the lens blank BLA, as well as various other data such as data which reflect
those contained in the memory MEM of the apparatus.
[0105] This output of the preparation PREP is conveyed through the communication module
COM and/or through the human-machine interface HMI, whereby it is then transferred
to the generator GEN.
[0106] During the surfacing SURF, the lens blank is then processed by the generator GEN,
the resulting surfaced lens SLE having the crib diameter D
crib determined during the preparation PREP.
[0107] The invention provides several advantages.
[0108] Indeed, it greatly helps reducing the variety of dimensions which result from the
surfacing of lens blanks in the context of the manufacture of ophthalmic lenses.
[0109] In addition, it is easily adaptable to various situations and constraints, which
may be imposed by the equipment which is available for the manufacturing.
[0110] Moreover, it does not require extensive calculation resources, and may therefore
be implemented on various types of computer devices.
[0111] The various aspects of the invention as detailed in the description are defined by
the appended claims.
1. A method of preparing a lens blank (BLA) for a further operation of surfacing of said
lens blank configured to transform the lens blank into a surfaced lens (SLE) at the
end thereof for further transformation into a lens (LEN) having a lens shape and destined
to be coupled to a frame, the operation of surfacing including processing the lens
blank (BLA) so that the surfaced lens exhibits a crib diameter (D
crib), the method being implemented using a processing module and comprising :
- based on input data (ID) which define the lens shape, defining a temporary crib
diameter (Dtemp) so that said temporary crib diameter satisfies a set of constraints which includes
at least:
- a first constraint whereby the temporary crib diameter (Dtemp) is large enough for the surfaced lens having said temporary crib diameter to be
suitable to be processed into said lens (LEN),
- a second constraint whereby the temporary crib diameter is large enough for the
surfaced lens having said temporary crib diameter to include a plurality of reference
points (PREF) defined on the lens
blank and which together identify an optical center of the lens,
- choosing the crib diameter (Dcrib) as a function of the temporary crib diameter (Dtemp), said choosing the crib diameter being configured so that, when a step cribbing
configuration is destined to be applied to the operation of surfacing, said crib diameter
is chosen among at least one predetermined discrete value (Vali).
2. The method according to claim 1, wherein the crib diameter (Dcrib) is chosen as corresponding to the smallest discrete value which is superior to the
temporary crib diameter (Dtemp).
3. The method according to claim 1 or 2, further comprising, when a surface extension
configuration is destined to be applied to the operation of surfacing, generating
a surface file to be used during the operation of surfacing for generating the lens
shape so that the lens shape is circular with a diameter corresponding to the crib
diameter (Dcrib).
4. The method according to claims 2 or 3, wherein said one or more predetermined discrete
value is formed by a single value.
5. The method according to any one of the preceding claims, wherein the temporary crib
diameter (Dtemp) is chosen as the smallest value which satisfies said set of constraints.
6. The method according to any one of the preceding claims, wherein the set of constraints
includes a third constraint according to which the temporary crib diameter is superior
or equal to a minimum crib diameter of an apparatus destined to be used to reduce
the diameter of the lens blank during the operation of surfacing.
7. The method according to any one of the preceding claims, wherein, for satisfying the
first constraint, the temporary crib diameter is taken as superior or equal to a lens
shape parameter defined based on twice a maximum radius of the lens shape.
8. The method according to any one of the preceding claims, wherein the lens shape parameter
is taken equal as twice the radius of the lens shape when the generated lens shape
is circular.
9. The method according to any one of the preceding claims, wherein the lens shape parameter
is taken equal as twice the sum of the maximum radius and of a margin defined based
on a shape of the frame the lens is destined to be coupled to.
10. The method according to any one of the preceding claims, wherein for satisfying the
second constraint, the temporary crib diameter (Dtemp) is chosen superior or equal to a reference parameter defined based on twice a distance
between a center of the lens shape in a blocking and turning referential of the lens
blank during the operation of surfacing and the reference point of the lens blank
which is the farthest away from said center.
11. The method according to claim 10, wherein the reference parameter is taken equal to
twice the sum of said distance and of a predetermined margin.
12. A computer program comprising instructions destined to be executed by a processor
for the implementation of the method according to any one of the preceding claims.
13. A method of surfacing a lens blank (BLA) configured to transform the lens blank into
a surfaced lens (SLE) at the end thereof for further transformation into a lens having
a lens shape and destined to be coupled to a frame, the method comprising:
- preparing the lens blank (BLA) for surfacing using a method of preparing a lens
blank according to any one of claims 1 to 11 to obtain a crib diameter, and
- surfacing the lens blank, said surfacing the lens blank including processing the
lens blank so that the surfaced lens exhibits the crib diameter.
14. A device for preparing a lens blank (BLA) for a further operation of surfacing of
said lens blank configured to transform the lens blank into a surfaced lens (SLE)
having a lens shape at the end thereof for further transformation into a lens (LEN)
to be coupled to a frame, the operation of surfacing including processing the lens
blank so that the surfaced lens (SLE) exhibits a crib diameter, the device comprising
a processing module (PROC) configured to:
- based on input data which define the lens shape, define a temporary crib diameter
(Dtemp) so that said temporary crib diameter (Dcrib) satisfies a set of constraints which includes at least:
- a first constraint whereby the temporary crib diameter is large enough for the surfaced
lens having said temporary crib diameter to be suitable to be processed into said
lens,
- a second constraint whereby the temporary crib diameter is large enough for the
surfaced lens having said temporary crib diameter to include a plurality of reference
points defined on the lens blank and which together identify an optical center of
the lens,
- choose the crib diameter (Dcrib) as a function of the temporary crib diameter (Dtemp), the processing module being configured to choose the crib diameter so that, in
response to a step cribbing configuration being destined to be applied to the operation
of surfacing, said crib diameter is chosen among at least one predetermined discrete
value.
1. Verfahren zum Herstellen eines Linsenrohlings (BLA) für eine weitere Operation der
Oberflächenbearbeitung des Linsenrohlings, konfiguriert zum Umwandeln des Linsenrohlings
in eine oberflächenbearbeitete Linse (SLE) am Ende davon zur weiteren Umwandlung in
eine Linse (LEN) mit einer Linsenform und bestimmt zum Koppeln an einen Rahmen, wobei
die Operation der Oberflächenbearbeitung das Verarbeiten des Linsenrohlings (BLA)
beinhaltet, so dass die oberflächenbehandelte Linse einen Fräsdurchmesser (D
crib) aufweist, wobei das Verfahren unter Verwendung eines Verarbeitungsmoduls implementiert
wird und umfasst:
- auf Basis von Eingangsdaten (ID), die die Linsengestalt definieren, Definieren eines
temporären Fräsdurchmessers (Dtemp), so dass der temporäre Fräsdurchmesser einen Satz von Beschränkungen erfüllt, der
mindestens enthält:
- eine erste Beschränkung, wodurch der temporäre Fräsdurchmesser (Dtemp) groß genug ist, dass die oberflächenbehandelte Linse mit dem temporären Fräsdurchmesser
zur Verarbeitung zu der Linse (LEN) geeignet ist,
- eine zweite Beschränkung, wodurch der temporäre Fräsdurchmesser groß genug ist,
dass die oberflächenbehandelte Linse mit dem temporären Fräsdurchmesser mehrere auf
dem Linsenrohling definierte Referenzpunkte (PREF) enthält, die zusammen eine optische
Mitte der Linse definieren,
- Wählen des Fräsdurchmessers (Dcrib) als eine Funktion des temporären Fräsdurchmessers (Dtemp), wobei das Wählen des Fräsdurchmessers so konfiguriert ist, so dass, wenn eine Stufenfräsoperation
auf die Operation der Oberflächenbehandlung angewendet werden soll, der Fräsdurchmesser
unter mindestens einem vorbestimmten diskreten Wert (Vali) gewählt wird.
2. Verfahren nach Anspruch 1, wobei der Fräsdurchmesser (Dcrib) so gewählt wird, dass er dem kleinsten diskreten Wert entspricht, der dem temporären
Fräsdurchmesser (Dtemp) überlegen ist.
3. Verfahren nach Anspruch 1 oder 2, weiterhin umfassend, wenn eine oberflächenerweiterungskonfiguration
auf die Operation der Oberflächenbehandlung angewendet werden soll, Erzeugen einer
Oberflächendatei zur Verwendung während der Operation der Oberflächenbehandlung zum
Erzeugen der Linsengestalt, so dass die Linsengestalt kreisförmig ist mit einem Durchmesser
entsprechend dem Fräsdurchmesser (Dcrib).
4. Verfahren nach Anspruch 2 oder 3, wobei der eine oder die mehreren vorbestimmten Werte
durch einen einzelnen Wert gebildet werden.
5. Verfahren nach einem der vorhergehenden Ansprüche, wobei der temporäre Fräsdurchmesser
(Dtemp) als der kleinste Wert gewählt wird, der den Satz von Beschränkungen erfüllt.
6. Verfahren nach einem der vorhergehenden Ansprüche, wobei der Satz von Beschränkungen
eine dritte Beschränkung enthält, gemäß der der temporäre Fräsdurchmesser einem kleinsten
Fräsdurchmesser einer Vorrichtung überlegen oder gleich ist, bestimmt zur Verwendung
zum Reduzieren des Durchmessers des Linsenrohlings während der Operation der Oberflächenbehandlung.
7. Verfahren nach einem der vorhergehenden Ansprüche, wobei, um die erste Beschränkung
zu erfüllen, der temporäre Fräsdurchmesser als überlegen oder gleich einem Linsengestaltparameter,
definiert auf Basis des Doppelten eines größten Radius der Linsengestalt, genommen
wird.
8. Verfahren nach einem der vorhergehenden Ansprüche, wobei der Linsengestaltparameter
gleich dem Doppelten des Radius der Linsengestalt genommen wird, wenn die erzeugte
Linsengestalt kreisförmig ist.
9. Verfahren nach einem der vorhergehenden Ansprüche, wobei der Linsengestaltparameter
gleich dem Doppelten der Summe des maximalen Radius und eines Spielraums, definiert
auf Basis einer Gestalt des Rahmens, an die die Linse gekoppelt werden soll, genommen
wird.
10. Verfahren nach einem der vorhergehenden Ansprüche, wobei zum Erfüllen der zweiten
Beschränkung der temporäre Fräsdurchmesser (Dtemp) überlegen oder gleich einem Referenzparameter, definiert auf Basis des Doppelten
einer Distanz zwischen einer Mitte der Linsengestalt in einer Blockier- und Drehreferenz
des Linsenrohlings während der Operation der Oberflächenbehandlung und dem Referenzpunkt
des Linsenrohlings, der von der Mitte am weitesten weg liegt, gewählt wird.
11. Verfahren nach Anspruch 10, wobei der Referenzparameter gleich dem Doppelten der Summe
aus der Distanz und einem vorbestimmten Spielraum genommen wird.
12. Computerprogramm umfassend Anweisungen, die durch einen Prozessor für die Implementierung
des Verfahrens gemäß einem der vorhergehenden Ansprüche ausgeführt werden soll.
13. Verfahren zur Oberflächenbehandlung eines Linsenrohlings (BLA), konfiguriert zum Umwandeln
des Linsenrohlings in eine oberflächenbearbeitete Linse (SLE) am Ende davon zur weiteren
Umwandlung in eine Linse mit einer Linsenform und bestimmt zum Koppeln an einen Rahmen,
wobei das Verfahren umfasst:
- Herstellen des Linsenrohlings (BLA) zur Oberflächenbehandlung unter Verwendung eines
Verfahrens zum Herstellen eines Linsenrohlings gemäß einem der Ansprüche 1 bis 11,
um einen Fräsdurchmesser zu erhalten, und
- Oberflächenbehandlung des Linsenrohlings, wobei die Oberflächenbehandlung des Linsenrohlings
das Verarbeiten des Linsenrohlings beinhaltet, so dass die oberflächenbehandelte Linse
den Fräsdurchmesser aufweist.
14. Einrichtung zum Herstellen eines Linsenrohlings (BLA) für eine weitere Operation der
Oberflächenbehandlung des Linsenrohlings, konfiguriert zum Umwandeln des Linsenrohlings
in eine oberflächenbehandelte Linse (SLE) mit einer Linsengestalt am Ende davon zur
weiteren Umwandlung zu einer Linse (LEN) zum Koppeln an einen Rahmen, wobei die Operation
der Oberflächenbehandlung die Verarbeitung des Linsenrohlings beinhaltet, so dass
die oberflächenbehandelte Linse (SLE) einen Fräsdurchmesser aufweist, wobei die Einrichtung
ein Verarbeitungsmodul (PROC) umfasst, das konfiguriert ist zum:
- auf Basis von Eingangsdaten, die die Linsengestalt definieren, Definieren eines
temporären Fräsdurchmessers (Dtemp), so dass der temporäre Fräsdurchmesser (Dcrib) einen Satz von Beschränkungen erfüllt, der mindestens enthält:
- eine erste Beschränkung, wodurch der temporäre Fräsdurchmesser groß genug ist, dass
die oberflächenbehandelte Linse mit dem temporären Fräsdurchmesser zur Verarbeitung
zu der Linse geeignet ist,
- eine zweite Beschränkung, wodurch der temporäre Fräsdurchmesser groß genug ist,
dass die oberflächenbehandelte Linse mit dem temporären Fräsdurchmesser mehrere auf
dem Linsenrohling definierte Referenzpunkte enthält, die zusammen eine optische Mitte
der Linse definieren,
- Wählen des Fräsdurchmessers (Dcrib) als Funktion des temporären Fräsdurchmessers (Dtemp) wobei das Verarbeitungsmodul zum Wählen des Fräsdurchmessers konfiguriert ist, so
dass als Reaktion auf eine Stufenfräsoperation, die auf die Operation der Oberflächenbehandlung
angewendet werden soll, der Fräsdurchmesser unter mindestens einem vorbestimmten diskreten
Wert gewählt wird.
1. Procédé de préparation d'une ébauche de lentille (BLA) pour une opération ultérieure
de surfaçage de ladite ébauche de lentille configurée pour transformer l'ébauche de
lentille en une lentille surfacée (SLE) aux fins d'une transformation ultérieure en
une lentille (LEN) ayant une forme de lentille et destinée à être couplée à une monture,
l'opération de surfaçage comprenant le traitement de l'ébauche de lentille (BLA) de
sorte que la lentille surfacée présente un diamètre de découpe (D
crib), le procédé étant mis en œuvre en utilisant un module de traitement et comprenant
:
- sur la base de données d'entrée (ID) qui définissent la forme de lentille, la définition
d'un diamètre de découpe temporaire (Dtemp) de sorte que ledit diamètre de découpe temporaire satisfait à un ensemble de contraintes
qui comprend au moins :
- une première contrainte selon laquelle le diamètre de découpe temporaire (Dtemp) est suffisamment grand pour que la lentille surfacée ayant ledit diamètre de découpe
temporaire soit adaptée pour être transformée en ladite lentille (LEN),
- une deuxième contrainte selon laquelle le diamètre de découpe temporaire est suffisamment
grand pour que la lentille surfacée ayant ledit diamètre de découpe temporaire comprenne
une pluralité de points de référence (PREF) définis sur l'ébauche de lentille et qui,
ensemble, identifient un centre optique de la lentille,
- le choix du diamètre de découpe (Dcrib) en fonction du diamètre de découpe temporaire (Dtemp), ledit choix du diamètre de découpe étant configuré de telle sorte que lorsqu'une
configuration de découpe par paliers est destinée à être appliquée à l'opération de
surfaçage, ledit diamètre de découpe est choisi parmi au moins une valeur discrète
prédéterminée (Vali).
2. Procédé selon la revendication 1, dans lequel le diamètre de découpe (Dcrib) est choisi comme correspondant à la plus petite valeur discrète qui est supérieure
au diamètre de découpe temporaire (Dtemp).
3. Procédé selon la revendication 1 ou 2, comprenant en outre, lorsqu'une configuration
d'extension de surface est destinée à être appliquée à l'opération de surfaçage, la
génération d'un fichier de surface à utiliser pendant l'opération de surfaçage pour
générer la forme de lentille de sorte que la forme de lentille est circulaire avec
un diamètre correspondant au diamètre de découpe (Dcrib) .
4. Procédé selon la revendication 2 ou 3, dans lequel lesdites une ou plusieurs valeurs
discrètes prédéterminées sont formées par une seule valeur.
5. Procédé selon l'une quelconque des revendications précédentes, dans lequel le diamètre
de découpe temporaire (Dtemp) est choisi comme la plus petite valeur qui satisfait ledit ensemble de contraintes.
6. Procédé selon l'une quelconque des revendications précédentes, dans lequel l'ensemble
de contraintes comprend une troisième contrainte selon laquelle le diamètre de découpe
temporaire est supérieur ou égal à un diamètre de découpe minimal d'un appareil destiné
à être utilisé pour réduire le diamètre de l'ébauche de lentille pendant l'opération
de surfaçage.
7. Procédé selon l'une quelconque des revendications précédentes, dans lequel, pour satisfaire
à la première contrainte, le diamètre de découpe temporaire est pris supérieur ou
égal à un paramètre de forme de lentille défini sur la base du double d'un rayon maximum
de la forme de lentille.
8. Procédé selon l'une quelconque des revendications précédentes, dans lequel le paramètre
de forme de lentille est pris égal à deux fois le rayon de la forme de lentille lorsque
la forme de lentille générée est circulaire.
9. Procédé selon l'une quelconque des revendications précédentes, dans lequel le paramètre
de forme de lentille est pris égal au double de la somme du rayon maximum et d'une
marge définie sur la base d'une forme de la monture à laquelle la lentille est destinée
à être couplée.
10. Procédé selon l'une quelconque des revendications précédentes, dans lequel pour satisfaire
à la deuxième contrainte, le diamètre de découpe temporaire (Dtemp) est choisi supérieur ou égal à un paramètre de référence défini sur la base de deux
fois une distance entre un centre de la forme de lentille dans un référentiel de blocage
et de rotation de l'ébauche de lentille pendant l'opération de surfaçage et le point
de référence de l'ébauche de lentille qui est le plus éloigné dudit centre.
11. Procédé selon la revendication 10, dans lequel le paramètre de référence est pris
égal à deux fois la somme de ladite distance et d'une marge prédéterminée.
12. Programme informatique comprenant des instructions destinées à être exécutées par
un processeur pour la mise en œuvre du procédé selon l'une quelconque des revendications
précédentes.
13. Procédé de surfaçage d'une ébauche de lentille (BLA) configuré pour transformer l'ébauche
de lentille en une lentille surfacée (SLE) aux fins d'une transformation ultérieure
en une lentille ayant une forme de lentille et destinée à être couplée à une monture,
le procédé comprenant :
- la préparation de l'ébauche de lentille (BLA) pour le surfaçage en utilisant un
procédé de préparation d'une ébauche de lentille selon l'une quelconque des revendications
1 à 11 pour obtenir un diamètre de découpe, et
- le surfaçage de l'ébauche de lentille, ledit surfaçage de l'ébauche de lentille
comprenant le traitement de l'ébauche de lentille de sorte que la lentille surfacée
présente le diamètre de découpe.
14. Dispositif pour préparer une ébauche de lentille (BLA) pour une opération ultérieure
de surfaçage de ladite ébauche de lentille, configuré pour transformer l'ébauche de
lentille en une lentille surfacée (SLE) ayant une forme de lentille aux fins d'une
transformation ultérieure en une lentille (LEN) destinée à être couplée à une monture,
l'opération de surfaçage comprenant le traitement de l'ébauche de lentille de sorte
que la lentille surfacée (SLE) présente un diamètre de découpe, le dispositif comprenant
un module de traitement (PROC) configuré pour :
- sur la base de données d'entrée qui définissent la forme de lentille, définir un
diamètre de découpe temporaire (Dtemp) de sorte que ledit diamètre de découpe temporaire (Dcrib) satisfait à un ensemble de contraintes qui comprend au moins :
- une première contrainte selon laquelle le diamètre de découpe temporaire est suffisamment
grand pour que la lentille surfacée ayant ledit diamètre de découpe temporaire soit
adapté pour être transformée en ladite lentille,
- une deuxième contrainte selon laquelle le diamètre de découpe temporaire est suffisamment
grand pour que la lentille surfacée ayant ledit diamètre de découpe temporaire comprenne
une pluralité de points de référence définis sur l'ébauche de lentille et qui, ensemble,
identifient un centre optique de la lentille,
- choisir le diamètre de découpe (Dcrib) en fonction du diamètre de découpe temporaire (Dtemp), le module de traitement étant configuré pour choisir le diamètre de découpe de
sorte que, en réponse à une configuration de criblage par étapes destinée à être appliquée
à l'opération de surfaçage, ledit diamètre de découpe est choisi parmi au moins une
valeur discrète prédéterminée.