METHOD OF DETERMINING SPECTACLE LENS EDGE DATA

PROCEDE DE DETERMINATION DE DONNEES CONCERNANT LE BORD D'UN VERRE DE LUNETTES

English Abstract

A method is disclosed of determining edging data for a spectacle lens edge.
This involves the following steps: first, an image of the inner contour of the
mount, i.e. of a former or template, is produced on a sheet on a scale of 1:1
by tracing the outline of the mount, i.e. of the former or template; the
calibre-defining points are marked in the image of the mount on the sheet; the
image of the mount with the marked-in calibre-defining points is recorded
using a scanner; and the scan data are passed via a telephone line to a
computer which determines the edge data. The method according to the invention
is characterized by the fact that a standard fax device, which transmits the
sheet to a receiver unit in the usual way, is used for transmitting the data
and the fax data received by the receiver unit are entered into a computer
which determines the appropriate edge data from the transmitted data.

French Abstract

L'invention concerne un procédé de détermination des données concernant le bord d'un verre de lunettes, ledit procédé comprenant les étapes suivantes: on réalise tout d'abord, sur une feuille, un dessin du contour intérieur de la monture ou d'un gabarit à l'échelle 1:1, en suivant avec un crayon les contours de la monture ou du gabarit. On marque ensuite les points définissant le calibre, sur la feuille, à l'intérieur du dessin de la monture, puis on scanne le dessin de la monture comportant les points définissant le calibre, avant de transférer, par l'intermédiaire d'une ligne téléphonique, les données scannées vers un ordinateur qui détermine les données de contours. Ce procédé est caractérisé en ce qu'il utilise, pour la transmission des données, un télécopieur standard transmettant la feuille de façon usuelle à une station réceptrice, et en ce que les données du télécopieur reçues par la station réceptrice sont introduites dans un ordinateur qui détermine les données de contours à partir des données transmises par télécopie.

Claims

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What Is Claimed Is:
1. A method of determining the edging data of an
ophthalmic lens, in which
- first a picture of the inside contour of the frames
respectively a form disk respectively a measurement disk
with a scale of 1:1 is made by tracing said frames
respectively said form disk respectively said measurement
disk on a sheet of paper using a drawing implement,
- the look-through points are drawn into said picture of
said frames on said sheet of paper,
- said picture of said frames with said drawn-in
look-through points is scanned, and
the scanning data are transmitted via a telephone line to
a computer which determines the edging data therefrom,
characterized by utilizing for the transmission of said
data a conventional commercial telefax machine which
transmits said page to a receiving station in a
conventional manner, and
by the telefax data received by said receiving station
being read into a computer which determines said edging
data from said telefax data.
2. A method according to claim 1.
characterized by for calibration of the transmitted data a
scale being provided on said page transmitted by telefax,
said scale being transmitted along with it and evaluated
by a computer.
3. A method according to claim 1 or 2,
characterized by other ordering data being provided on
said telefax transmitted page and therefore transmitted
along with it.

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4. A method according to claim 3,
characterized by other ordering data being transmitted
in for a computer directly evaluatable manner.
5. A method according to one of the claims 1 to 4,
characterized by a computer determining from said telefax
data only the required minimum diameter of the rough round
ophthalmic lens.
6. A method according to one of the claims 1 to 5,
characterized by a computer using said telefax data to
optimize the center thickness.
7. A method according to one of the claims 1 to 6,
characterized by a computer calculating from said telefax
data the edging data for an edging device.
8. A method according to claim 7,
characterized by a computer controlling the edging device.
9. A method according to one of the claims 1 to 8,
characterized by a drawing implement attached to a
pantogram being utilized as a drawing implement.
10. A method according to one of the claims 1 to 9,
characterized by a computer with a fax card, said computer
comtemporarily storing said telefax data, being utilized.
11. A method according to claim 10,
characterized by in addition a printout of said telefax
data being made for control purposes.

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12. A method according to claim 11,
characterized by said printout being made by a telefax
machine which is connected in parallel to said computer.
13. A method according to claim 11,
characterized by said printout being made by a readout
device, such as, e.g., a printer, connected to said
computer.
14. A method according to one of the claims 1 to 13,
characterized by the computer calculated edging data being
fed off-line into said edging device.
15. A method according to one of the claims 1 to 14,
characterized by said computer-calculated edging data
being fed directly into said edging device.

Description

2'1 96280
Method of Determining Edging Data
D e s c r i p t i o n
Technical Field
The present invention relates to a method of determining
edging data of an ophthalmic lens according to the generic
part of claim 1.
State of the Art
For some time, most of the edging devices for ophthalmic
lenses on the market, such as grinding machines, do not
operate as copying machines that "copy" the edging of the
ophthalmic lenses of a so-called form disk, but rather are
numerically controlled. In order to be able to calculate
the needed numerical edging data for a specific to-be-
edged ophthalmic lens for operating a grinding machine, it
not only requires knowing the course of the so-called
lens rings of the spectacle frames in a numerically
evaluatable form, but also knowing the location of the
individual look-through point of the ophthalmic lens in
relation to the respective spectacle frame, if need be, in
a numerically evaluatable form.
In practice, there is frequently the problem of the
customer bringing along to the optician's spectacle
frames, into which he/she wants the new ophthalmic lenses
to be inserted. Usually no set of data is available for
the brought along spectacle frames. Furthermore, not all
spectacle frame manufacturers supply "sets of numerical
data" which can be entered directly into the respective

2,96280
existent edging device for their models.
Therefore, it is necessary to determine the contour of
existent spectacle frames respectively the respective
measurement disk and form disk numerically in order to be
able to control the edging device accordingly. For this
purpose, so-called "tracers" have been employed in
practice. In these tracers, a pin traces the spectacle
frames respectively the respective disk.
However, these tracers are relatively expensive so that
their purchase is not worthwile for small opticians,
because weeks can go by before small shops may need to use
a tracer. Moreover, tracers from different manufacturers
use different data formats for the measured results so
that the obtained numerical sets of data often cannot be
employed as order data sets for different ophthalmic lens
manufacturers.
US patent 5,257,198 proposes a method in which the use of
a tracer can be obviated by tracing a picture of the frame
with a drawing implement on a sheet of paper. The look-
through point is then drawn into the picturè of the frames.
Obviously, this picture of the frames is digitally
collected using a special digitalizer and transmitted to a
computer via a line, which by way of illustration, can be
a telephone line. The edging data determined by the
computer from the transmitted digital data are used for
controlling the actual edging device.
However, this method also has a number of drawbacks:

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Obviously, conventional commercial devices are not
utilized, because it is explicitly said that the function
of the digitalizer, which is not described in more detail,
is "similar to", but obviously not the same as conventional
scanners or fax machines (column 4, line 20 ff. of US
patent 5 257 198). Therefore, the purchase of a special
device for passing on the data required for determining
the edging data to the manufacturer of the ophthalmic lens
is still necessary.
Moreover, in this method, the priorly determined digital
data are converted. In other words, the data have to be
converted with a special data structure, which under
certain circumstances does not permit ordering from
different manufacturers of ophthalmic lenses.
Description of the Invention
The object of the present invention is to further improve a
method of determining the edging data of an ophthalmic
lens according to the generic part of claim 1 in such a
manner that the edging data can be determined at the
optician's and permits conveying the edging data to any
manufacturer and therefore passing on the edging data to
any manufacturer and therefore ordering from any
manufacturer without the optician having to purchase a
special device for determining the ordering data.
A solution to this object according to the present
invention is given in claim 1. Further improvements of the
present invention are the subject matter of the dependent
claims.
The present invention is based on the fundamental idea
that presently practically every optician shop has a

4 ~96230
telefax machine. The reason for this is that, in order to
avoid errors, most ophthalmic lens suppliers have switched
to taking orders by telefax instead of taking orders by
telephone as has hitherto been the practice.
This, conventional commercial and without additional
auxilliary options, telefax is employed according to the
present invention to receive the contour of the spectacle
frames respectively the form disk respectively the
measurement disk in a "numerically evaluatable" manner.
For this purpose, first a 1:1 scale picture of the inside
contour of the frame respectively the form disk is
produced. This image can be made in any manner and, in
particular, by placing the frames on a sheet of paper and
tracing with a drawing implement, such as a pencil, a
ballpoint pen or the like, the outer respectively inside
contour of the frame respectively the outer contour of the
form disk or measurement disk.
Errorless tracing of the contour of the spectacle frames
respectively the disk is simplified by using a drawing
implement that is attached to a so-called pantograph.
Guiding the drawing implement with a pantograph, which
ensures "straight positioning" of the writing implement,
prevents errors like those that can occur in tracing the
frames respectively the disk "by hand".
In addition, the look-through point can be additionally
drawn into the picture of the frames in an as such known
manner and can be evaluated by a computer. In this way,
the supplier receives all the data needed for edging a
ophthalmic lens in a numerically evaluatable form without
using any special "data format" for transmission but
rather the worldwide normed "telefax data format" (tif).

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The picture is transmitted with this telefax machine to a
receiving station located at the supplier's. The telefax
data is read into a computer at the supplier's, which
draws from the data, the data required for the respective
order.
In order to be independent from possible scale
transmission errors, according to claim 2 it is preferred
if a scale is transmitted for calibrating the transmitted
data. This scale can, by way of illustration, be a
"reticle" with known dimensions. In this way, it is
immaterial if the optician's telefax device enlarges or
reduces the read-in picture for the transmission.
On the page, or on an additional page, transmitted by
telefax to the supplier respectively the manufacturer of
the rough round or edged ophthalmic lens, there can, of
course, be other ordering data, such as the spherical
action of the ophthalmic lens, if need be the cylindrical
action and the position of the axis, the material of the
ophthalmic lens, if need be the tint of the lenses,
antireflection coatings, etc.
These order data can then be manually evaluated, by being
fed into a computer, or preferably evaluated by means of
an OCR process or a direct evaluation process (claim 3):
In particular, certain order options which can be marked
with an x when ordering and which the supplier can
evaluate numerically can be printed on the page with the
picture of the frame or on an additional page. By way of
illustration, if the telefax is directly "read into" a
computer via a telefax card, the computer can directly

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.
evaluate the "x's" beside the order options, thereby
reducing misunderstandings on the supplier side.
The invented method has the advantage that the data are
compiled by the optician without the supplier needing a
special data system, because the picture of the frames is
transmitted via a standard telefax transmission system
without using a special numerical data system. Evaluation
of the transmitted picture data "representing an analogue
picture" is not evaluated until it is at the supplier's.
If the supplier is supposed to only select for grinding a
rough round ophthalmic lens suited to the respective
frames and the grinding itself is to be carried out at the
optician's, it suffices if the supplier's computer
determines the required minimum diameter of the rough
round ophthalmic lens (claim S).
Of course, with the invented method the computer cannot
only calculate from the transmitted telefax data the
required minimum diameter of the ophthalmic lens for
specific frames and given look-through points, the
computer can also use the telefax data to optimize center
thickness (claim 6) and/or to calculate the edging data
for an edging device (claim 7).
In particular, the computer can also directly control the
edging device (claim 15) in such a manner that the
supplier delivers already edged ophthalmic lenses to the
optician which only need to be inserted into the frames,
thereby reducing the amount of equipment that an optician
needs to have.

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The edging data calculated by the computer can, of course,
be fed off-line into the optician's edging device, by way-
of illustration by sending the optician a diskette (claim 14).
Although, the printout of a conventional commercial
telefax machine used as a receiving station by the
supplier can be numerically evaluated there using a
scanner or the like, it is preferred according to claim 10
if a computer with a fax card is employed which the
computer temporarily stores the telefax data, thereby
eliminating all the errors that can occur with the
printout of the transmitted telefax data and/or their
evaluation with a scanner.
Of course, a printout of the telefax data can be
additionally made for control purposes (claim 11). This
printout can be made by a telefax machine that is
connected in parallel to the computer (claim 12) or by a
readout device that is directly connected to the computer,
such as e.g., a printer (claim 13).
All the device components that are needed for the
realization of the present invention are known:
The optician only requires a sheet of paper, if need be
with a scale printed on it or put on it later including
order options, and a conventional commercial telefax
machine without needing any extras.
The supplier also only needs, in addition to a computer
with a suited program, a conventional commercial telefax
machine and an evaluation unit for the telefax printout
respectively a conventional computer telefax card.

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Therefore, somone skilled in the art working in the
pertinent field is able to realize the present invention
on the basis of the previous description thus obviating a
description of a preferred embodiment and a drawing.