U.S. patent application number 13/847841 was filed with the patent office on 2013-08-22 for method of manufacturing an optical system.
The applicant listed for this patent is Pascal Allione, Jean-Pierre Chauveau, Gilles Le Saux, Denis Mazuet. Invention is credited to Pascal Allione, Jean-Pierre Chauveau, Gilles Le Saux, Denis Mazuet.
Application Number | 20130218533 13/847841 |
Document ID | / |
Family ID | 35500854 |
Filed Date | 2013-08-22 |
United States Patent
Application |
20130218533 |
Kind Code |
A1 |
Allione; Pascal ; et
al. |
August 22, 2013 |
Method of Manufacturing an Optical System
Abstract
A method of calculating an optical system (OS), the optical
system (OS) being identified by a function (OF), the optical system
(OS) having a first part (F1) defined by a first equation (EF1) and
a second part (F2) defined by a second equation (EF2), the method
performed by: a generating step (GEN), in which a virtual optical
system (VOS) is used to generate a virtual function (VOF); a
modification step (MOD), in which the virtual function (VOF) is
modified so as obtain the function (OF); a calculation step (CAL),
in which the second equation (EF2) is calculated from the function
(OF), and the first equation (EF1). A method of manufacturing an
optical system (OS) is also disclosed.
Inventors: |
Allione; Pascal; (Charenton
Le Pont, FR) ; Le Saux; Gilles; (Charenton Le Pont,
FR) ; Chauveau; Jean-Pierre; (Charenton Le Pont,
FR) ; Mazuet; Denis; (Charenton Le Pont, FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Allione; Pascal
Le Saux; Gilles
Chauveau; Jean-Pierre
Mazuet; Denis |
Charenton Le Pont
Charenton Le Pont
Charenton Le Pont
Charenton Le Pont |
|
FR
FR
FR
FR |
|
|
Family ID: |
35500854 |
Appl. No.: |
13/847841 |
Filed: |
March 20, 2013 |
Current U.S.
Class: |
703/1 |
Current CPC
Class: |
G02B 3/0081 20130101;
G02C 7/028 20130101; G06F 30/00 20200101; G02B 3/10 20130101; G02C
7/061 20130101; G02C 2202/08 20130101; B29D 11/00971 20130101; B29D
11/00009 20130101 |
Class at
Publication: |
703/1 |
International
Class: |
G06F 17/50 20060101
G06F017/50 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 11, 2005 |
EP |
05291716.8 |
Claims
1. A method of manufacturing an optical system (OS), the optical
system (OS) being identified by a function (OF), the optical system
(OS) comprising a first part (F1) defined by a first equation
(EF1), EF1(x,y,z), which defines opto-geometric properties of part
F1 at a spatial location defined by coordinates x, y, and z, and a
second part (F2), defined by a second equation (EF2), EF2(x,y,z),
which defines opto-geometric properties of part F2, where the first
part (F1) and the second part (F2) are a volume or surface of the
optical system, (OS), the method comprising(EF1) and a second part
(F2) defined by a second equation (EF2), the method comprising: a
first providing step that provides the first equation (EF1),
EF1(x,y,z), said first equation (EF1), EF1(x,y,z) defining
opto-geometric properties of the first part (F1) of the optical
system (OS); a second providing step that provides the function
(OF), said function identifying the optical system (OS), said
second providing step comprising: a generating sub-step (GEN), in
which a virtual optical system (VOS) calculated and generated by a
computer is used to generate a virtual function (VOF) calculated
and generated by a computer; then a modification sub-step (MOD), in
which the virtual function (VOF) is modified to obtain the
function(OF); and a calculation step (CAL), in which the second
equation (EF2) is calculated from the function (OF), and the first
equation (EF1); providing a semi-finished optical system (MSFOS)
with a semi-finished optical system (SFOS) comprising the first
part (F1); and a manufacturing step (M2), in which the
semi-finished optical system (MSFOS) is manufactured so as to be
further provided with a second part (F2) defined by the second
equation (EF2) and to obtain the optical system (OS).
2. The method according to claim 1, wherein the method further
comprises an equation modifying step, in which the first virtual
equation (EVF1) is modified by using a first modifying function
(N1) so as to obtain a first modified equation (EV'F1), the first
equation (EF1) being substantially equal to the first modified
equation (EVF+1), and the second manufacturing step (M2) comprising
the following sub-steps: a second modifying step (MS2), in which
the second virtual equation EVF2 is modified by using a second
modifying function (N2) so as to obtain a second modified equation
EV'F2, the first modifying function (N1) and the second modifying
function (N2) being defined in such a manner that the optical
system can be identified by the function (OF), and: a second
manufacturing step (MAN2), in which the second part (F2) of the
semi- finished optical system (SFOS) is manufactured so as to
obtain the optical system (OS), the second equation (EF2) of the
second part (F2) being substantially equal to the second modified
equation (EV'F2).
3. An optical system comprising two parts, the optical system (OS)
being identified by a function (OF), the optical system being
manufactured with a method according to claim 1.
4. A method of manufacturing an optical system (OS), the optical
system (OS) being identified by a function (OF), the optical system
(OS) comprising a first part (F1) defined by a first equation
(EF1), EF1(x,y,z), which defines opto-geometric properties of part
F1 at a spatial location defined by coordinates x, y, and z, and a
second part (F2), defined by a second equation (EF2), EF2(x,y,z),
which defines opto-geometric properties of part F2, where the first
part (F1) and the second part (F2) are a volume or surface of the
optical system, (OS), the method comprising: a first providing step
that provides the first equation (EF1), EF1(x,y,z), said first
equation (EF1), EF1(x,y,z) defining opto-geometric properties of
the first part (F1) of the optical system (OS); a second providing
step that provides the function (OF), said function identifying the
optical system (OS), said second providing step comprising: a
generating sub-step (GEN), in which a virtual optical system (VOS)
calculated and generated by a computer is used to generate a
virtual function (VOF) calculated and generated by a computer; then
a modification sub-step (MOD), in which the virtual function (VOF)
is modified to obtain the function(OF); and a calculation step
(CAL), in which the second equation (EF2) is calculated from the
function (OF), and the first equation (EF1); a first manufacturing
step (M1) in which a semi-finished optical system (SFOS) comprising
the first part (F1) is manufactured so as to obtain a manufactured
semi-finished optical system (MSFOS); and a second manufacturing
step (M2), in which the manufactured semi-finished optical system
(MSFOS) is manufactured so as to be further provided with a second
part (F2) defined by the second equation (EF2) and to obtain the
optical system (OS).
5. The method according to claim 4, wherein the method further
comprises an equation modifying step, in which the first virtual
equation (EVF1) is modified by using a first modifying function
(N1) so as to obtain a first modified equation (EV'F1), the first
equation (EF1) being substantially equal to the first modified
equation (EVF+1), and the second manufacturing step (M2) comprising
the following sub-steps: a second modifying step (MS2), in which
the second virtual equation EVF2 is modified by using a second
modifying function (N2) so as to obtain a second modified equation
EV'F2, the first modifying function (N1) and the second modifying
function (N2) being defined in such a manner that the optical
system can be identified by the function (OF), and: a second
manufacturing step (MAN2), in which the second part (F2) of the
semi-finished optical system (SFOS) is manufactured so as to obtain
the optical system (OS), the second equation (EF2) of the second
part (F2) being substantially equal to the second modified equation
(EV'F2).
6. The method according to claim 5, wherein the second virtual part
(VF2) comprises a second volume of the virtual optical system
(VOS), the second equation depending on opto-geometric
characteristics of the second volume, and wherein the second
modifying function (N2) modifies at least one of said
opto-geometric characteristics
7. An optical system comprising two parts, the optical system (OS)
being identified by a function (OF), the optical system being
manufactured with a method according to claim 4.
8. An optical system comprising two parts, the optical system (OS)
being identified by a function (OF), the optical system being
manufactured with a method according to claim 5.
9. An optical system comprising two parts, the optical system (OS)
being identified by a function (OF), the optical system being
manufactured with a method according to claim 6.
10. A semi- finished optical system (MSFOS) manufactured according
to the first manufacturing step (M1) and intended to be modified by
the second manufacturing step (M2) of claim 4.
11. A semi- finished optical system (MSFOS) manufactured according
to the first manufacturing step (M1) and intended to be modified by
the second manufacturing step (M2) of claim 5.
12. A semi- finished optical system (MSFOS) manufactured according
to the first manufacturing step (M1) and intended to be modified by
the second manufacturing step (M2) of claim 6.
13. A method of manufacturing an optical system (OS), the optical
system (OS) being identified by a function (OF), the optical system
(OS) comprising a first part (F1) defined by a first equation
(EF1), EF1(x,y,z), which defines opto-geometric properties of part
F1 at a spatial location defined by coordinates x, y, and z, and a
second part (F2), defined by a second equation (EF2), EF2(x,y,z),
which defines opto-geometric properties of part F2, where the first
part (F1) and the second part (F2) are a volume or surface of the
optical system, (OS), the method comprising: a first providing step
that provides the first equation (EF1), EF1(x,y,z), said first
equation (EF1), EF1(x,y,z) defining opto-geometric properties of
the first part (F1) of the optical system (OS); a second providing
step that provides the function (OF), said function identifying the
optical system (OS), said second providing step comprising: a
generating step (GEN), in which a virtual optical system (VOS)
calculated and generated by a computer is used to generate a
virtual function (VOF) calculated and generated by a computer; a
modification step (MOD), in which the virtual function (VOF) is
modified to obtain the function(OF); and a calculation step (CAL),
in which the second equation (EF2) is calculated from the function
(OF), and the first equation (EF1); a first manufacturing step
(M1), in which a semi-finished optical system (SFOS) comprising the
first part (F2) is manufactured so as to obtain a manufactured
semi-finished optical system (MSFOS); and a second manufacturing
step (M2), in which the manufactured semi-finished optical system
(MSFOS) is manufactured so as to be further provided with a first
part (F1) defined by the first equation (EF1) and to obtain the
optical system (OS).
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application
Ser. No. 11/997,359 which was filed with the U.S. Patent and
Trademark Office on Jan. 30, 2008 as a National Stage of
International Application No. PCT/IB2006/003220, which claims
priority from European Patent Application No. 05291716.8 filed on
Aug. 11, 2005, the entire contents of which are incorporated by
reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] An aspect of the invention relates to a method calculating
and/or a method of manufacturing an optical system, and more
particularly a progressive power lens. Other aspects of the
invention relate to a method of manufacturing a semi-finished
optical system, a computer-program product for calculating and/or
manufacturing an optical system, a computer-program product for
calculating and/or manufacturing a semi-finished optical
system.
[0004] 2. Description of the Related Art
[0005] Progressive power lenses typically comprise a far-vision
region having one refractive power, a near-vision region having a
different refractive power, and an intermediate progressive
region.
[0006] According to a common practice, semi-finished progressive
lens blanks are provided by lens manufacturer to prescription labs.
Generally a semi-finished progressive lens blank comprises a front
progressive surface and a back spherical surface ("standard
semi-finished lens blank"). A standard semi-finished lens blank
having suitable optical characteristics is then selected based on a
prescription. The back spherical surface is finally machined and
polished by the prescription lab (based on the base curve) so as to
obtain a sphero-torical surface complying with the prescription. A
progressive power lens complying with the prescription is thus
obtained.
SUMMARY OF THE INVENTION
[0007] According to an aspect, the invention relates to a method of
calculating an optical system OS, the optical system OS being
identified by a function OF, the optical system OS comprising a
first part F1 defined by a first equation EF1 and a second part F2
defined by a second equation EF2, the method comprising: [0008] a
generating step GEN, in which a virtual optical system VOS is used
to generate a virtual function VOF; [0009] a modification step MOD,
in which the virtual function VOF is modified so as obtain the
function OF; [0010] a calculation step CAL, in which the second
equation EF2 is calculated from the function OF, and the first
equation EF1.
[0011] The optical system OS can be, for example, a progressive
power lens. The function OF can be, for example, an optical
function OF or a part of an optical function OF. The first part and
the second part can be, for example, any volume or surface of the
optical system. The optical function OF of an optical system OS is
defined as a function h of the opto-geometric properties of the
optical system OS, which can be written, for a two parts system
comprising a first part F1 and a second part F2, [0012]
OF=h(EF1(x,y,z), EF2(x,y,z)) [0013] EF1(x,y,z) defining the
opto-geometric properties of part F1 [0014] EF2(x,y,z) defining the
opto-geometric properties of part F2
[0015] According to a feature of the invention, the virtual optical
system VOS comprises a first virtual part VF1 defined by a first
virtual equation EVF1 and a second virtual part VF2 defined by a
second virtual equation EVF2, the first virtual equation EVF1 and
the second virtual equation EVF2 defining the virtual function
VOF.
[0016] According to a feature of the invention, the virtual
function VOF is substantially equal to the function OF.
[0017] According to a feature of the invention, the generating step
comprises selecting the first virtual equation EVF1 in a
database.
[0018] According to a feature of the invention, the method further
comprises an equation modifying step, in which the first virtual
equation EVF1 is modified by using a first modifying function N1 so
as to obtain a first modified equation EV'F1, the first equation
EF1 being substantially equal to the first modified equation
EVF'1.
[0019] According to previous feature, the first virtual part VF1
comprises a first volume of the virtual optical system VOS, the
first equation depending on opto-geometric characteristics of the
first volume, and wherein the first modifying function N1 modifies
at least one of said opto-geometric characteristics.
[0020] According to previous feature, the opto-geometric
characteristics comprise at least one characteristic chosen among
the equation of a surface and the optical index of a volume.
[0021] According to another feature of the invention, the first
virtual part VF1 is a first virtual surface and the second virtual
part VF2 is a second virtual surface.
[0022] According to previous feature of the invention, the function
OF depends on the difference of the equations of the first surface
and the second surface, and wherein a second surface modifying
function N2 is substantially equal to the first surface modifying
function N1.
[0023] According to another feature of the invention, the function
OF is an optical function OF.
[0024] According to a feature of the invention, the optical system
OS is a progressive power lens.
[0025] According to another aspect, the invention relates to a
method of manufacturing an optical system OS, the optical system OS
being identified by a function OF, the optical system OS comprising
a first part F1 defined by a first equation EF1 and a second part
F2 defined by a second equation EF2, the method comprising: [0026]
the generating step GEN, modification step MOD, calculation step
CAL as previously disclosed, in which the second equation EF2 is
calculated from the function OF, and the first equation EF1; [0027]
providing a semi-finished optical system MSFOS with a semi-finished
optical system SFOS comprising the first part F1; and [0028] a
manufacturing step M2, in which the semi-finished optical system
MSFOS is manufactured so as to be further provided with a second
part F2 defined by the second equation EF2 and to obtain the
optical system OS. According to a feature of the invention
[0029] According to another aspect, the invention relates to a
method of manufacturing an optical system OS, the optical system OS
being identified by a function OF, the optical system OS comprising
a first part F1 defined by a first equation EF1 and a second part
F2 defined by a second equation EF2, the method comprising: [0030]
the generating step GEN, modification step MOD, calculation step
CAL as previously disclosed, in which the second equation EF2 is
calculated from the function OF, and the first equation EF1; [0031]
a first manufacturing step M1 in which a semi-finished optical
system SFOS comprising the first part F1 is manufactured so as to
obtain a manufactured semi-finished optical system MSFOS; and
[0032] a second manufacturing step M2, in which the manufactured
semi-finished optical system MSFOS is manufactured so as to be
further provided with a second part F2 defined by the second
equation EF2 and to obtain the optical system OS.
[0033] According to the invention, the first manufacturing step M1
defines the opto-geometric characteristics EF1(x,y,z) of the first
part F1 of the semi-finished optical system. Thus, by choosing a
suitable second part F2, the invention allows the manufacture of an
optical system such that OF=h (EF1(x,y,z), EF2(x,y,z)).
[0034] In other words, if a semi-finished optical system was
manufactured according to the first manufacturing step M1, and was
firstly intended to be modified to manufacture a first optical
system OS1 having an optical function OF1, the semi-finished
optical system can advantageously be used to manufacture a second
optical system OS2, having a second optical function OF2. In this
respect, the second equation EF2 has just to be chosen such that
OF2=h (EF1(x,y,z)), EF2(x,y,z))), and not OF1=h (EF1(x,y,z)),
EF2(x,y,z))).
[0035] Therefore, the optical system does not depend on the
characteristics of the semi-finished optical system only. This
allows a manufacturer to stock semi-finished optical system
independently of the optical system. Thus, the invention enables to
enhance the stock management in a manufacturing process.
[0036] According to a feature of the invention the second
manufacturing step M2 comprises the following sub-steps: [0037] a
second modifying step MS2, in which the second virtual equation
EVF2 is modified by using a second modifying function N2 so as to
obtain a second modified equation EV'F2, the first modifying
function N1 and the second modifying function N2 being defined in
such a manner that the optical system can be identified by the
function OF, and [0038] a second manufacturing step MAN2, in which
the second part F2 of the semi finished optical system SFOS is
manufactured so as to obtain the optical system OS, the second
equation EF2 of the second part F2 being substantially equal to the
second modified equation EV'F2.
[0039] According to previous feature, the second virtual part VF2
comprises a second volume of the virtual optical system VOS, the
second equation depending on opto-geometric characteristics of the
second volume, and wherein the second modifying function N2
modifies at least one of said opto-geometric characteristics.
[0040] According to another aspect, the invention relates to a
method of manufacturing an optical system OS, the optical system OS
being identified by a function OF, the optical system OS comprising
a first part F1 defined by a first equation EF1 and a second part
F2 defined by a second equation EF2, the method comprising [0041]
the generating step GEN, modification step MOD, calculation step
CAL as previously disclosed, in which the second equation EF2 is
calculated from the function OF, and the first equation EF1; [0042]
a first manufacturing step M1, in which a semi-finished optical
system SFOS comprising the first part F2 is manufactured so as to
obtain a manufactured semi-finished optical system MSFOS; and
[0043] a second manufacturing step M2, in which the manufactured
semi-finished optical system MSFOS is manufactured so as to be
further provided with a first part F1 defined by the first equation
EF1 and to obtain the optical system OS
[0044] For the purpose of the present application, the term
"virtual" is used to define an optical system which is calculated
and generated by a computer. According to the present invention,
the virtual optical system is not intended to be manufactured as
such.
[0045] By generating a virtual optical system and defining the
optical function as a modification of a virtual optical function,
one can ensure that the calculation step CAL according to the
invention has a solution. For example, if the optical function OF
is substantially equal to the virtual optical function VOF, and the
first equation EF1 is substantially equal to the first virtual
equation, the second virtual equation EVF2 is a physical solution
for the second equation EF2.
[0046] The virtual optical function can, for example, be modified
by using prescription data provided by an Eye Care Practitioner.
Thus, by modifying this virtual function, the optical function can
be more adapted to the characteristics of the eye.
[0047] Moreover, by defining the optical function from the
modification of a virtual optical function, memory space is saved.
In fact, instead of storing the optical functions for each specific
client, the method according to the invention allows to store a
generic virtual function and to modify it by a specific
modification.
[0048] According to another aspect, the generating step according
to the invention comprises selecting the first virtual equation
EVF1 in a database.
[0049] By selecting the first virtual equation in a database of
known virtual equations, one can ensure that the performances of
the optical system can be those of an existing system.
[0050] Moreover, by avoiding the calculation of a specific first
equation and by selecting the equation in a database, calculation
time is saved.
[0051] According to another aspect of the invention, the method
further comprises an equation modifying step, in which the first
virtual equation EVF1 is modified by using a first modifying
function N1 so as to obtained a first modified equation EV'F1, the
first equation EF1 being substantially equal to the first modified
equation EVF'1.
[0052] The first modifying function N1 can be, for example,
arranged to modify the opto-geometric characteristics of the first
virtual part VF1 such that: [0053] OF=h(N1(VF1(x,y,z)),
EF2(x,y,z)))
[0054] By providing standard semi finished optical system to
prescription labs, it is quite easy to obtain data that might be
considered by the lens manufacturer as secret data. This can be
achieved, for example, by using well-known three dimensional
measuring systems. The secret data can be, for example, data
relating to the geometry of the progressive face of the
semi-finished lens blank. The secret data can also be, for example,
any opto-geometric characteristics in particular the equations of
the surfaces defining the two parts, or the optical index of the
two parts, or any combination thereof.
[0055] By using the first modifying function in order to modify the
first parts of a virtual optical system VOS in order to manufacture
a semi finished optical system and an optical system having the
required optical function, the secret data are split up between the
first and the second part of the optical system. Thus it is more
difficult to deduce the secret data by using a measuring
system.
[0056] The invention also concerns a computer program product for a
data-processing device, the computer program product comprising a
set of instructions which, when loaded into the data-processing
device, causes the device to perform the steps of the method
according to the invention, for an optical system, or for a
semi-finished optical system.
[0057] Other objects and features of the present invention will
become apparent from the following detailed description considered
in conjunction with the accompanying drawings. It is to be
understood, however, that the drawings are designed solely for
purposes of illustration and not as a definition of the limits of
the invention, for which reference should be made to the appended
claims. It should be further understood that the drawings are not
necessarily drawn to scale and that, unless otherwise indicated,
they are merely intended to conceptually illustrate the structures
and procedures described herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0058] The subject matter regarded as the invention is particularly
pointed out and distinctly claimed in the concluding portion of the
specification. The invention, however, both as to organization and
method of operation, together with objects, features and advantages
thereof, may best be understood by reference to the following
detailed description when read with the accompanied drawings in
which:
[0059] FIG. 1A shows a graphical representation of an array of
power;
[0060] FIG. 1B shows a graphical representation of an array of
astigmatism;
[0061] FIG. 1C shows an example of data used to determine the
optical function of an optical system;
[0062] FIG. 1D shows the longitude and latitude data used to
represent the array of power and the array of astigmatism;
[0063] FIG. 2 is a block diagram of the manufacturing process
according to the invention;
[0064] FIG. 3 is a block diagram of an embodiment of the
manufacturing process according to the invention;
[0065] FIG. 4A schematically illustrates a virtual system generated
according to the present invention;
[0066] FIG. 4B schematically illustrates a modified virtual system
according to the present invention;
[0067] FIG. 5A schematically illustrates a virtual system generated
according to the present invention;
[0068] FIG. 5B schematically illustrates a semi-finished optical
system manufactured according to the present invention;
[0069] FIG. 5C schematically illustrates an optical system
manufactured according to the present invention;
[0070] FIG. 6A corresponds to a semi-finished optical system as in
FIG. 5B.
[0071] FIG. 6B schematically illustrates an optical system
manufactured according to the present invention wherein the optical
index has been modified to comply with the optical function.
DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS
[0072] Unless specifically stated otherwise, as apparent from the
following discussions, it is appreciated that throughout the
specification discussions utilizing terms such as "computing",
"calculating" "generating", or the like, refer to the action 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 computing
system's registers and/or memories into other data similarly
represented as physical quantities within the computing system's
memories, registers or other such information storage, transmission
or display devices.
[0073] Embodiments of the present invention may include apparatuses
for performing the operations herein. This apparatus may be
specially constructed for the desired purposes, or it may comprise
a general purpose computer or 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 is not limited to,
any type of disk including floppy disks, optical disks, CD-ROMs,
magnetic-optical disks, read-only memories (ROMs), random access
memories (RAMs) electrically programmable read-only memories
(EPROMs), electrically erasable and programmable read only memories
(EEPROMs), magnetic or optical cards, or any other type of media
suitable for storing electronic instructions, and capable of being
coupled to a computer system bus.
[0074] 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 a more specialized apparatus to perform the desired
method. The desired structure for a variety of these systems will
appear from the description below. In addition, embodiments of the
present invention are not described with 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 inventions as described herein.
[0075] The optical function OF of an optical system OS can be
defined as follows: [0076] OF(x,y,z)=MAT(x,y,z)+PRES; or (1) [0077]
OF(x,y,z)=MAT(PUI(x,y,z); AST(x,y,z))+PRES; or (2) [0078]
OF(x,y,z)=h(F1(x,y,z); F2(x,y,z); n(x,y,z)) (3) [0079] MAT being an
array of power and astigmatism; [0080] PUI being an array of power;
[0081] AST being an array of astigmatism; [0082] PRES being
prescription data; [0083] F1 and F2 being the equation of the first
face and of the second face of the optical system; and [0084] n
being the optical index.
[0085] It has to be noted that if the optical index is a constant,
the optical function OF of an optical system can be defined as
follows: [0086] OF(x,y,z)=h(F1(x,y,z); F2(x,y,z)) (4)
[0087] An example of graphical representation of an array of power
PUI and of an array of astigmatism AST is shown at FIG. 1A and FIG.
1B. These arrays (PUI,AST) have been obtained for a design suitable
for a user with emmetropia addition 2. Illustrated FIG. 1D, the
gaze direction is defined by two angles, latitude .alpha. and
longitude .beta. from the center of rotation of the eye. The
aberrations are calculated for each gaze direction to obtain array
MAT and array PUI.
[0088] The prescription data PRES are known by the one skilled in
the art and are related to usual data provided by an Eye Care
Practitioner such as sphere, cylinder, axe, prism, power addition.
Additional data provided by an optician can be used if
available.
[0089] Advantageously, but not limited to, in the ophthalmic field
the optical function can be obtained by adding the prescribed
values of power and astigmatism to specific arrays, respectively
PUI and AST. In general, these specific arrays can be given, for
example, for each addition and ametropia type (myopia, hyperopia,
emmetropia).
[0090] In order to better understand the invention, a method of
manufacturing an optical system OS in the form of a progressive
power lens will now be described in a detailed manner. In this
particular example, the optical index can be chosen as a constant.
The optical function of an optical system can thus be defined as
follows: [0091] OF=h(F1(x,y), F2(x,y)) (5)
[0092] As illustrated FIG. 2, the method of manufacturing a
progressive power lens OS comprises a manufacturing step M1 in
which a semi-finished optical system comprising a first part F1 is
manufactured. The first part F1 is defined by a first equation EF1,
which is for example the equation of an outer surface. A
manufactured semi-finished optical system MSFOS is thus
obtained.
[0093] According to the invention, the equation of the second part
EF2 is then determined in a calculation step CAL from the optical
function and the equation of the first part EF1. Equations (5) and
(4) are used to determine such an equation from the optical
function OF and the equation of the first surface EF1.
[0094] The calculation step CAL can be performed by using a
ray-tracing method or optimization algorithms. These methods are
known by the one skilled in the art, for example in the publication
"Application of optimization in computer-aided ophthalmic lens
design" (P. Allione, F. Ahsbhs and G. Le Saux, in SPIE Vol. 3737,
EUROPTO Conference on Design and Engineering of Optical Systems,
Berlin, May 1999), which is incorporated by reference in the
present document.
[0095] In a second manufacturing step M2, the manufactured
semi-finished optical system MSFOS is manufactured so as to obtain
a second part of equation EF2. This can be done by any known method
in the art of manufacturing lenses as described, for example, in
the US granted patent referenced under grant number U.S. Pat. No.
6,558,586 B1, the content of which is incorporated by
reference.
[0096] The manufactured semi-finished optical system MSFOS further
provided with a second part F2 of equation EF2 forms the optical
system OS.
[0097] In a particular embodiment, the optical function OF of the
optical system OS to be manufactured is based on a virtual optical
function VOF.
[0098] In a virtual optical system generating step GEN, a virtual
progressive power lens VOS having a virtual optical function VOF is
generated. As illustrated in FIG. 4A and 4B, the virtual
progressive power lens VOS comprises a first virtual face VF1 which
is defined by a first equation EVF1. The virtual progressive power
lens VOS farther comprises a second virtual face VF2 which is
defined by a second equation EVF2.
[0099] The virtual optical function VOF can then be modified in a
modification step MOD to obtain an optical function OF. The
modified virtual optical system MVOS has a modified first face MVF1
and a modified second face MVF2.
[0100] The modification MOD can be made by using prescription data
from an Eye Care Practitioner to be adapted to the
prescription.
[0101] The modification MOD can be without limitation an isometric
transformation such as offset, symmetry, translation, or a morphing
of the virtual optical system VOS.
[0102] If the modification is chosen as the identity function, the
modified virtual optical system is the virtual optical system, and
the optical function is substantially equal to the virtual optical
function.
[0103] A preset virtual optical function VOF can then be retrieved
directly from a database to define the opto-geometric
characteristics of the virtual optical system.
[0104] The modification step MOD can then be used to adapt this
virtual optical function VOF to the needs of a particular
wearer.
[0105] For example, if a database containing virtual optical
function is available, one can choose, among the database, a
virtual optical function corresponding to the general
characteristics of the wearer. A more accurate adaptation of this
virtual optical function is then performed in a modification step
MOD to adapt the optical system OS to the more precise needs of the
wearer.
[0106] As illustrated in FIG. 3, according to another aspect, the
method of manufacturing a progressive power lens OS comprises a
first manufacturing step M1 and a second manufacturing step M2. It
further comprises a virtual optical system generating step GEN and
a first modifying stop MS1.
[0107] In the virtual optical system generating step GEN, a virtual
progressive power lens VOS having a virtual optical function VOF is
generated. As illustrated in FIG. 5A, the virtual progressive power
lens VOS comprises a first virtual face VF1 which is defined by a
first equation EVF1. The virtual progressive power lens VOS further
comprises a second virtual face VF2 which is defined by a second
equation EVF2. The first equation EVF1 and the second equation EVF2
are chosen such that: [0108]
VF(x,y,z)=vh(EVF1(x,y,z),EVF2(x,y,z))
[0109] EVF1(x,y) and EVF2(x,y) can be defined, for example, such
that the optical function VF of the virtual progressive power lens
VOS is substantially equal to the optical function OF of the
progressive power lens OS.
[0110] As illustrated in FIG. 3, in a first modifying step MS1, the
first equation EVF1(x,y) is modified, for example, by adding a
first encryption function N1(x,y) so as to obtain a modified
equation EV'F1 defined as follows: [0111]
EV'F1(x,y)=EVF1(x,y)+N1(x,y).
[0112] Then, in a first manufacturing step Ml, a first surface F1
of a semi-finished optical system SFOS is manufactured. The
equation EF1 of the first surface F1 is defined as follows: [0113]
EF1(x,y)=EV'F1(x,y)
[0114] A semi-finished optical system SFOS is thus obtained. The
manufacturing of the semi-finished optical system SFOS can be done
by any known method in the art of manufacturing lenses as
described, for example, in the US granted patent referenced under
grant number U.S. Pat. No. 6,558,586 B1, the content of which is
incorporated by reference. It has to be noted that, the first
encrypting function N1(x,y) is a secret data which is only known by
the one implementing the method of manufacturing of the invention.
The first encrypting function N1 can be more generally any secret
transformation of the function EVF1(x,y) such that [0115]
EF1(x,y)=N1[EVF1(x,y)].
[0116] Thus when analyzing the semi-finished optical system SFOS,
it will be more difficult for a third party to access to the secret
data EVF1(x,y) and EVF2(x,y).
[0117] As illustrated in FIG. 3, the method of manufacturing a
progressive power lens further comprises a second manufacturing
step M2. The second manufacturing step M2 comprises a second
modifying sub-step MS2 and a second manufacturing sub-step
MAN2.
[0118] In the second modifying sub-step MS2, the second equation
EVF2(x,y) is modified, for example, by adding a second encrypting
function N2(x,y) so as to obtained a second modified equation
EV'F2(x,y) defined as follows: [0119]
EV'F2(x,y)=EVF2(x,y)+N2(x,y),
[0120] The second encryption function N2(x,y) is chosen such that
[0121] OF(x,y)=h(N1 [EVF1(x,y)], N2[EVF2(x,y)]).
[0122] It has to be understood that other constraints can be added
in the choice of the first and second encrypting functions N1 and
N2. Such constraints can be linked, for example, to calculation
time or other constraints defined by manufacturing
laboratories.
[0123] Then in a second manufacturing sub-step MAN2, a second face
F2 of the semi-finished optical system SFOS is manufactured so as
to obtain the progressive power lens OS. The surface of the second
face F2 of the progressive power lens OS is defined by the second
modified equation EV'F2(x,y).
[0124] It is understood that the first and the second face F1, F2
of the progressive power lens OS must comply with the constraints
defined by the optical function OF
[0125] When the optical function is a function of the difference of
the equations of the surfaces, i.e OF=h(EF2(x,y)-EF1(x,y)), the
preferred second encryption function N2(x,y) is substantially equal
to N1(x,y).
[0126] According to an advantage of the invention, the first
encrypting function and the second encrypting N1 and N2 only depend
on the optical system OS to be manufactured. A semi-finished
optical system SFOS provided with a first face F1 of equation
EF1(x,y)=N1[EVF1(x,y)] can thus be used, for example, to
manufacture an optical system OS1 having an optical function OF1.
But the same semi-finished optical system SFOS could also be used
to manufacture an optical system OS2 having an optical function
OF2. In this case, the second encrypting function N2 has to be
chosen such that OF2(x,y)=h (N1(EVF1(x,y)), N2(EVF2(x,y))). The
stock management of semi-finished optical systems SFOS can thus be
done by associating the semi-finished optical systems SFOS with the
optical system to be manufactured. Alternatively the stock
management of semi-finished optical systems SFOS can be done
independently of the final optical system by choosing suitable
modifying functions. The stock management in the manufacturing
process is therefore improved.
[0127] The detailed description hereinbefore with reference to the
drawings illustrates a method of manufacturing an optical system
OS, the optical system OS being identified by a function OF, the
optical system OS comprising a first part F1 defined by a first
equation EF1 and a second part F2 defined by a second equation EF2,
the method comprising: [0128] a calculation step CAL, in which the
second equation EF2 is calculated from the function OF, and the
first equation EF1; [0129] a first manufacturing step M1, in which
a semi-finished optical system SFOS comprising the first part F1 is
manufactured so as to obtain a manufactured semi-finished optical
system MSFOS; and a second manufacturing step M2, in which the
manufactured semi-finished optical system MSFOS is manufactured so
as to be further provided with a second part F2 defined by the
second equation EF2 and to obtain the optical system OS.
[0130] The aforementioned characteristics can be implemented in
numerous different manners. In order to illustrate this, some
alternatives are briefly indicated.
[0131] The first part and the second part can correspond to any
volume or surface of the optical system.
[0132] The first part and the second part can be, for example, a
first face and a second face of the optical system corresponding to
front and back optical surfaces, or a first volume and a second
volume of the optical system corresponding to a back part and a
front part of the system. The opto-geometric characteristics can
be, for example, the equations of the surfaces defining the two
parts, or the optical index of the two parts, or any combination
thereof.
[0133] The calculation of the second equation EF2 from the function
OF, and the first equation EF1 in the calculation step CAL can be
performed by any algorithm known in the art of calculation on
optical systems.
[0134] The detailed description hereinbefore with reference to the
drawings also illustrates a method that further comprises the
following steps: [0135] a generating step GEN, in which a virtual
optical system VOS is used to generate a virtual function VOF, the
virtual optical system VOS comprising a first virtual part VF1
defined by a first virtual equation EVF1 and a second virtual part
VF2 defined by a second virtual equation EVF2, the first virtual
equation EVF1 and the second virtual equation EVF2 defining the
virtual function VOF; [0136] a modification step MOD, in which the
virtual function VOF is modified so as obtain the function OF.
[0137] The modification MOD can be without limitation an isometric
transformation such as offset, symmetry, translation, or a morphing
of the virtual optical system VOS.
[0138] The detailed description hereinbefore with reference to the
drawings also illustrates a method which further comprises an
equation modifying step, in which the first virtual equation EVF1
is modified by using a first modifying function N1 so as to
obtained a first modified equation EV'F1, the first equation EF1
being substantially equal to the first modified equation EVF'1.
[0139] The first modifying function N1 can be, for example, an
encryption function or a noise function. The noise function can be
any discontinuous function such as, for example, a diffractive
function, in particular, a Fresnel function. Advantageously, the
discontinuous function has a spatial frequency cut-off which is
preferably less than 1 mm.sup.-1 (1/1 millimeter). The noise
function can also be, for example, a white noise function. More
generally the first function N1 can be any function arranged to
modify the opto-geometric characteristics of the parts or surfaces
of an optical system.
[0140] The detailed description also illustrates a method of
manufacturing an optical system OS, wherein the second
manufacturing step M2 comprises the following sub-steps: [0141] a
second modifying step MS2, in which the second virtual equation
EVF2 is modified by using a second modifying function N2 so as to
obtain a second modified equation EV'F2, the first modifying
function N1 and the second modifying function N2 being defined in
such a manner that the optical system can be identified by the
function OF, and [0142] a second manufacturing step MAN2, in which
the second part F2 of the semi-finished optical system SFOS is
manufactured so as to obtain the optical system OS, the second
equation EF2 of the second part F2 being substantially equal to the
second modified equation EV'F2.
[0143] The second modifying function N2 can be, for example, an
encryption function or noise function, in particular a white noise
function
[0144] The functions described herein have been given in Cartesian
coordinates (x,y,z) but it is understood that any coordinate can be
used in the method according to the invention.
[0145] In the detailed description, the equations of the surfaces
of the systems have been modified. It has to be understood that any
other opto-geometric characteristics can be modified. As
illustrated FIGS. 6A and 6B, the second modifying function N2 can
be a modification of the optical index n.sub.2(x,y,z) in a part P2
of the modified semi finished optical system. This modification is
indicated by dashed lines on FIG. 4B. Therefore, N2 has to be
chosen such that OF1=h(N1(EVF1(x,y), N2(P2(x,y,z))). Any
modification on the opto-geometric characteristics of the system,
either for surface characteristics or volume characteristics can
also be chosen, provided it respects the optical function OF or a
specific part of the optical function OF of the optical system.
[0146] Moreover, in the above examples, the function F was an
optical function OF. But the function F can be also a part of such
optical function OF. For example, for a given optical system having
an optical function OF given by the equation OF
(x,y,z)=MAT(x,y,z)+PRES, the function F can be defined by the array
of power and astigmatism MAT. In such a case, the modifying
functions N1 and N2 are such that MAT=g(EVF1, EVF2), and
MAT=g(N1(EVF1), N2(EVF2)). More generally the function F can be any
function arranged to identify or define an optical system OS.
[0147] Further examples are given to illustrate the present
invention with detailed and concrete cases, without any limitation
to other concrete applications.
Example 1
[0148] Example 1 relates to index variation of the material of a
lens. [0149] 1.1 Definition of the Virtual Optical System VOS:
[0150] VOS is a progressive lens with a progressive front surface
and a spherical back surface, such as a VARILUX COMFORT.RTM. lens
of ESSILOR Company, (for example with a 0 Dioptrie far vision
correction), for example a VARILUX COMFORT.RTM. Base 5.50 with 2
Dioptries addition, where the material of the lens consists of
ORMA.RTM. (refractive index=1.5).
[0151] The respective position of the front and back surfaces are
such as the thickness of the lens is as little as possible and
where the thickness in its center is more than 1 mm and its edge's
thickness is more than 0.3 mm. The prism between the two surfaces
has to compensate the thickness differences between far vision zone
and near vision zone due to addition, or is suitable to obtain a
given prismatic prescription. [0152] 1.2 Building the Virtual
Optical Function VOF:
[0153] A virtual viewer VV has a prescription with 2 Dioptries
addition, with a cylinder correction of 0 Dioptrie and a sphere
correction of 0 Dioptrie.
[0154] The power and astigmatism is calculated for a set of gaze
direction (a.sub.i, b.sub.i) for the system "lens"+"eye" in given
environment.
[0155] For said optical system OS, virtual optical function is:
[0156]
VOF(OS)=Sum[weight.sub.--ast(i)(AST(a.sub.i,b.sub.i,OS)-AST(a.sub.i,b.su-
b.i,VOS)).sup.2+weight.sub.--pui(i)(PUI(a.sub.i,b.sub.i,OS)-PUI(a.sub.i,b-
.- sub.i,VOS)).sup.2],
[0157] Where:
[0158] Sum is the sum on i index;
[0159] AST(a,b,v) is the astigmatism of optical system v for gaze
direction (a,b);
[0160] PUI(a,b,v) is the power for gaze direction (a,b) of optical
system v.
[0161] Following the invention, the lens OS of the real viewer RV,
has to be as close as possible including RV prescription.
[0162] Modification MOD is then applied. [0163] 1.3 Modification
MOD of the Virtual Optical Function VOF: [0164]
MOD(VOF(OS))=Sum[weight.sub.--ast(i)(ASR(a.sub.i,b.sub.i,OS,Sph,Cyl,Axe)-
-
AST(a.sub.i,b.sub.i,VOS)).sup.2+weight.sub.--pui(i)((PUI(a.sub.i,b.sub.-
i,- OS)- Sph)-PUI(a.sub.i,b.sub.i,VOS)).sup.2],
[0165] Where:
[0166] ASR (a,b,v,Sph,Cyl,Axe) is the resulting astigmatism of the
lens OS, for the real viewer RW, and when considering his spherical
prescription Sph, his cylindrical prescription Cyl, his axial
prescription Axe.
[0167] It is thus the vectorial difference between the lens OS and
the real viewer RV astigmatism. [0168] 1.4. Definition of the Lens
OS:
[0169] Characteristics of OS are for example: [0170] progressive
front surface VARILUX COMFORT.RTM. base 5.5 addition 2.0 Dioptries;
[0171] back surface to be determined in the step CAL; [0154]
refractive index of material=1.8; [0172] thickness of the lens as
little as possible and where the centre's thickness is more than 1
mm, and the edge's thickness is more than 0.3 mm; the prism between
the two surfaces has to compensate the thickness difference between
far vision zone and near vision zone due to an addition, or are
suitable to obtain a given prismatic prescription.
[0173] The front surface may be the same than the one of VOS.
Modification due to refractive index modification will then appear
on the back surface.
[0174] The front surface may be different from the one of VOS, and
adapted to the actual refractive index. Said front surface will be
consequently calculated.
[0175] First part F1 consists of: [0176] front surface; [0177]
material of the lens [0178] relative position of front and back
surfaces.
[0179] Second part F2 consists of: [0180] back surface
[0181] First equation EF1 consists of: [0165] front surface
equation; refractive index; 4.times.4 array of position changes
between front and back surfaces
[0182] Second equation EF2 consists of: [0169] equation of back
surface.
[0183] Front and back surfaces equations can be expressed for
example by using two dimensions polynomial functions, such as
Zernike polynomes, B-Splines functions, NURBS functions. [0184] 1.5
Calculation Step CAL:
[0185] Determining back surface parameters to minimize MOD
(VOF(OS)).
[0186] Curvature parameters may be forced, for example in some
regions of far vision zone or near vision zone.
[0187] Example 1 shows it is thus possible to manufacture an
optical system OS from a virtual optical system VOS, the optical
system OS having substantially the same optical properties than
those of the virtual optical system VOS, but with a different
refractive index.
Example 2
[0188] Example 2 relates to a design modification of the
progressive surface of a lens. [0189] 2.1 Definition of the Virtual
Optical System VOS:
[0190] Characteristics are for example: [0191] front progressive
surface, with its design, for example VARILUX COMFORT.RTM. Base
5.50 with an addition of 2.0 Dioptries; [0192] spherical back
surface with 0 Dioptrie far vision correction ORMA.RTM. material
(refractive index is 1.5) [0193] respective position of the front
and back surfaces are such as the thickness of the lens is as
little as possible and where the thickness in its center is more
than 1 mm and its edge's thickness is more than 0.3 mm. The prism
between the two surfaces has to compensate the thickness
differences between far vision zone and near vision zone due to
addition, or is suitable to obtain a given prismatic prescription.
[0194] 2.2 Building the Virtual Optical Function VOF: [0195]
Virtual viewer has, for example, a prescription where: [0196] Sph=0
Dioptrie [0185] Cyl=0 Dioptrie [0197] Add=2.0 Dioptries and same
virtual optical function VOF then above following 1.2. [0198] 2.3
Modification MOD of the Virtual Optical of the Function VOF: [0199]
same step than above following 1.3. [0200] 2.4. Definition of the
Lens OS: [0201] front progressive surface with an other design than
the virtual one, such as for example VARILUX.RTM. PANAMIC.RTM. Base
5.50 of ESSILOR Company with an addition of 2.0 Dioptries; [0202]
back surface to be determined in the step CAL; [0203] refractive
index=1.5 (ORMA.RTM. material) [0204] thickness of the lens as
little as possible and where the centre's thickness is more than 1
mm, and the edge's thickness is more than 0.3 mm; the prism between
the two surfaces has to compensate the thickness difference between
far vision zone and near vision zone due to an addition, or is
suitable to obtain a given prismatic prescription;
[0205] First part F1 consists of: [0206] front surface; [0207]
material of the lens; [0208] relative position of front and back
surfaces.
[0209] Second part F2 consists of: [0210] back surface
[0211] First equation EF1 consists of: [0212] front surface
equation; [0213] refractive index; [0214] 4.times.4 array of
position changes between front and back surfaces
[0215] Second equation EF2 consists of [0216] equation of back
surface.
[0217] Front and back surface equation can be expressed for example
by using two dimensions polynomial functions, such as Zernike
polynomes, B-Splines functions, NURBS functions. [0218] 2.5
Calculation Step CAL: [0219] Same step than above following 1.5
[0220] Example 2 shows it is thus possible to manufacture an
optical system OS having a particular design, from a semi finished
optical system SFOS comprising a part F1 having a different design,
the optical system OS having substantially the same optical
properties than those of the virtual optical system VOS.
[0221] In the above mentioned description, the optical system OS
was a progressive power lens. It has to be understood that it can
also be any type of optical system, for example, a lens or a
multifocal lens. The optical system can also be any a device for
either concentrating or diverging light. The optical system can
also be any analogous device used with other types of
electromagnetic radiation such as a microwave lens for example made
from paraffin wax. The optical system can also be a part of an
imaging system such as monocular, binoculars, telescope, spotting
scope, telescoping gun sight, microscope and camera (photographic
lens).
[0222] The optical system can also be dielectric lens for radio
astronomy and radar systems to refract electromagnetic radiation
into a collector antenna.
[0223] The remarks made herein before demonstrate that the detailed
description with reference to the drawings, illustrate rather than
limit the invention. There are numerous alternatives, which fall
within the scope of the appended claims. Any reference sign in a
claim should not be construed as limiting the claim. The word
"comprising" does not exclude the presence of other elements or
steps than those listed in a claim. The word "a" or "an" preceding
an element or step does not exclude the presence of a plurality of
such elements or steps.
[0224] Thus, while there have shown and described and pointed out
fundamental novel features of the invention as applied to a
preferred embodiment thereof, it will be understood that various
omissions and substitutions and changes in the form and details of
the devices illustrated, and in their operation, may be made by
those skilled in the art without departing from the spirit of the
invention. For example, it is expressly intended that all
combinations of those elements and/or method steps which perform
substantially the same function in substantially the same way to
achieve the same results are within the scope of the invention.
Moreover, it should be recognized that structures and/or elements
and/or method steps shown and/or described in connection with any
disclosed form or embodiment of the invention may be incorporated
in any other disclosed or described or suggested form or embodiment
as a general matter of design choice. It is the intention,
therefore, to be limited only as indicated by the scope of the
claims appended hereto.
* * * * *