U.S. patent application number 09/406843 was filed with the patent office on 2002-03-21 for eyeglass lens processing system.
Invention is credited to MIZUNO, TOSHIAKI, SHIBATA, RYOJI.
Application Number | 20020034921 09/406843 |
Document ID | / |
Family ID | 17549917 |
Filed Date | 2002-03-21 |
United States Patent
Application |
20020034921 |
Kind Code |
A1 |
MIZUNO, TOSHIAKI ; et
al. |
March 21, 2002 |
EYEGLASS LENS PROCESSING SYSTEM
Abstract
An eyeglass lens processing system includes: input means for
inputting frame shape data and layout data; grinding means having
holding means for sucking and holding the subject lens at one end
of a rotating shaft for nipping and rotating the subject lens, for
grinding the subject lens by a grinding wheel; lens conveying means
for holding the subject lens placed at a predetermined position and
conveying the subject lens to an intended position;
amount-of-eccentricity measuring means for detecting a position of
an optical center of the subject lens held by the lens conveying
means and for obtaining an amount of eccentricity of the optical
center of the subject lens with respect to a predetermined
reference position; and calculating means for obtaining processing
data for the sucked and held subject lens by causing the reference
position and the center of the rotating shaft to be aligned with
each other by the lens conveying means, on the basis of data on the
frame shape, the layout data, and the amount of eccentricity.
Inventors: |
MIZUNO, TOSHIAKI; (AICHI,
JP) ; SHIBATA, RYOJI; (AICHI, JP) |
Correspondence
Address: |
SUGHRUE MION ZINN MACPEAK & SEAS PLLC
2100 PENNSYLVANIA AVENUE NW
WASHINGTON
DC
20037
|
Family ID: |
17549917 |
Appl. No.: |
09/406843 |
Filed: |
September 29, 1999 |
Current U.S.
Class: |
451/5 ; 451/41;
451/8 |
Current CPC
Class: |
B24B 13/005 20130101;
B24B 9/14 20130101; B24B 41/005 20130101; B29D 11/00961 20130101;
B24B 49/12 20130101 |
Class at
Publication: |
451/5 ; 451/8;
451/41 |
International
Class: |
B24B 049/00; B24B
051/00; B24B 001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 29, 1998 |
JP |
HEI 10-275031 |
Claims
What is claimed is:
1. An eyeglass lens processing system comprising: data input means
for inputting processing condition data, the processing condition
data including frame shape data of an eyeglass frame to which a
lens is to be fitted, and layout data for providing a layout of the
lens with respect to the frame; arithmetic means for obtaining
processing data for the lens based on the data thus inputted; lens
processing means for grinding a periphery of the lens, the lens
processing means including: two lens rotating shafts for clamping
and rotating the lens; holding means for sucking and holding the
lens onto at least one of the lens rotating shafts; a rotatable
grinding wheel; and processing control means for controlling a
rotational angle of the lens rotating shafts and an axis-to-axis
distance between a lens rotation axis and a grinding wheel rotation
axis; lens conveying means for holding and conveying the lens,
which has been disposed at a storing position, to an intended
position; and eccentricity measuring means for obtaining an optical
center of the lens held by the lens conveying means and obtaining
an quantity of eccentricity of the optical center with respect to a
predetermined reference position, wherein the holding means holds
the lens so that the lens rotation axis is coincident with the
reference position or the optical center, and wherein the
arithmetic means obtains the processing data based on the frame
shape data, the layout data and the quantity of eccentricity if the
lens is held so that the lens rotation axis is coincident with the
reference position, and the arithmatic means obtains the processing
data based on the frame shape data and the layout data if the lens
is held so that the lens rotation axis is coincident with the
optical center.
2. The eyeglass lens processing system as set forth in claim 1,
further comprising: judging means for judging whether or not the
quantity of eccentricity obtained by the eccentricity measuring
means falls within a predetermined range.
3. The eyeglass lens processing system as set forth in claim 2,
wherein the holding means holds the lens so that the lens rotation
axis is coincident with the reference position if the judging means
judges that the quantity of eccentricity is within the
predetermined range, and the holding means holds the lens so that
the lens rotation axis is coincident with the optical center if the
judging means judges that the quantity of eccentricity is outside
the predetermined range.
4. The eyeglass lens processing system as set forth in claim 1,
further comprising: selecting means for selecting a position with
which the lens rotation axis is made coincident by the holding
means.
5. The eyeglass lens processing system as set forth in claim 4,
wherein the selecting means selects a geometric center
corresponding position of the lens corresponding to a geometric
center of the eyeglass frame, and the holding means holds the lens
so that the lens rotation axis is coincident with the geometric
center corresponding position.
6. The eyeglass lens processing system as set forth in claim 1,
further comprising: cylinder axis measuring means for measuring a
direction of a cylinder axis of the lens held by the lens conveying
means, wherein the data input means inputs an angle of the cylinder
axis included in a prescription, and the arithmetic means obtains
the processing data, taking into account the direction of the
cylinder axis and the angle of the cylinder axis.
7. The eyeglass lens processing system as set forth in claim 1,
wherein the lens conveying means conveys the lens to be positioned
at either of the storing position, a first predetermined position
located on a measurement axis of the eccentricity measuring means,
and a second predetermined position located between the lens
rotating shafts.
8. The eyeglass lens processing system as set forth in claim 7,
wherein the lens conveying means conveys the lens so that the
reference position is coincident with the measurement axis of the
eccentricity measuring means when the lens is positioned at the
first predetermined position, and the reference position or the
optical center is coincident with the lens rotation axis when the
lens is positioned at the second predetermined position.
9. The eyeglass lens processing system as set forth in claim 1,
wherein the data input means includes eyeglass frame measuring
means for measuring a frame shape of an eyeglass frame or a
template thereof.
10. An eyeglass lens processing system comprising: a data input
unit which inputs processing condition data, the data input unit
including an input screen and an input switch, the processing
condition data including frame shape data of an eyeglass frame to
which a lens is to be fitted, and layout data which provide a
layout of the lens with respect to the frame; an arithmetic unit
which obtains processing data for the lens based on the data thus
inputted; a lens processing apparatus which grinds a periphery of
the lens, the lens processing apparatus including: two lens
rotating shafts which clamps and rotates the lens; a rotatable
grinding wheel; and a processing control unit which is connected to
the arithmetic unit and controls a rotational angle of the lens
rotating shafts and an axis-to-axis distance between a lens
rotation axis and a grinding wheel rotation axis; a lens conveying
apparatus which holds and conveys the lens, which has been disposed
at a storing position, to an intended position, the lens conveying
apparatus having at least one arm; and an eccentricity measuring
apparatus which obtains an optical center of the lens held by the
arm of the lens conveying apparatus and obtains an quantity of
eccentricity of the optical center with respect to a predetermined
reference position, wherein the lens rotating shafts hold the lens
so that the lens rotation axis is coincident with the reference
position or the optical center, and wherein the arithmetic unit
obtains the processing data based on the frame shape data, the
layout data and the quantity of eccentricity if the lens is held so
that the lens rotation axis is coincident with the reference
position, and the arithmetic unit obtains the processing data based
on the frame shape data and the layout data if the lens is held so
that the lens rotation axis is coincident with the optical
center.
11. The eyeglass lens processing system as set forth in claim 10,
wherein the data input unit includes an eyeglass frame measuring
unit having a feeler brought into contact with a groove of the
eyeglass frame, and the eyeglass frame measuring unit
three-dimensionally measures a frame shape of the eyeglass frame
based on an amount of movement of the feeler.
12. The eyeglass lens processing system as set forth in claim 10,
further comprising: a control unit connected to the data input
unit, the arithmetic unit, the lens processing apparatus, the lens
conveying apparatus, and the eccentricity measuring apparatus.
13. The eyeglass lens processing system as set forth in claim 12,
wherein the data inputted by the data input means are inputted into
the control unit through a public communication line.
14. The eyeglass lens processing system as set forth in claim 10,
wherein at least one of the lens rotating shaft is provided with a
hole communicated through a suction tube to a pump unit to hold the
lens under vacuum.
15. The eyeglass lens processing system as set forth in claim 10,
wherein the lens conveying apparatus includes two arms having
respective holes communicated through a suction tube with a pump
unit to hold the lens under vacuum.
16. The eyeglass lens processing system as set forth in claim 10,
wherein the eccentricity measuring apparatus includes a grid index
of a predetermined pattern, an illuminating unit which illuminates
the grid index and the lens held by the arm of the lens conveying
apparatus by a substantially parallel beam of light, a screen onto
which an image of the thus illuminated grid pattern is projected,
and an image pick-up unit which picks up the thus projected image
of the grid pattern.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to an eyeglass lens processing
system for grinding a peripheral edge of a subject lens.
[0002] Conventionally, in a case where the peripheral edge of a
subject lens is ground, processing is performed after a cup serving
as a processing jig (a flared suction cup or the like) is attached
to the optical center of the lens. A primary purpose of using the
cup is to fix the lens so that the lens will not move due to the
load applied from a grinding wheel during processing. The
followings are other purposes.
[0003] When a monofocal lens is processed, a marked point is
preliminarily applied to the optical center of the lens by using a
lens meter, and the cup is attached to the lens through a cup
attaching device, i.e., a so-called aligner, with that marked point
used as a reference mark. Subsequently, a cup portion is mounted on
a cup holder of a lens chuck shaft provided in a processing
apparatus, and the lens is chucked to perform processing. As a
result, the processing apparatus is able to effect processing while
managing the relationship between the rotational center of the lens
and the optical center thereof.
[0004] In contrast, to attach the lens directly to the processing
apparatus without using the cup, it is necessary to attach the lens
by aligning the marked point on the lens and the center of the lens
chuck shaft, and it is extremely difficult to enable it in the
light of the structure of the apparatus.
[0005] In recent years, processing centers have been established
where the lens processing which has been conventionally performed
by optical shops is performed intensively. The processing centers
have come to perform large volumes of lens processing in a
concentrated manner in response to requests from optical shops. In
such processing centers, there has been a demand for automation of
processing so as to effect processing efficiently by saving the
trouble of the operator as much as possible.
[0006] However, as mentioned above, the lens processing requires,
the above-described cup attaching operation as a preliminary step
before the processing and the cup removing operation as a
subsequent step after the processing, which has been a difficult
factor in realizing the automation of processing. In addition,
since these operations have been performed manually by the
operator, the operating efficiency has been poor.
SUMMARY OF THE INVENTION
[0007] In view of the above-described problems of the conventional
art, it is an object of the present invention to provide a
processing system which makes it possible to effect processing
while managing the relationship between the rotational center and
the optical center (and the angle of the cylinder axis) of the lens
during processing without using the cup as a processing jig.
[0008] To overcome the above object, the present invention is
characterized by having the following configurations.
[0009] (1) An eyeglass lens processing system comprising:
[0010] data input means for inputting processing condition data,
the processing condition data including frame shape data of an
eyeglass frame to which a lens is to be fitted, and layout data for
providing a layout of the lens with respect to the frame;
[0011] arithmetic means for obtaining processing data for the lens
based on the data thus inputted;
[0012] lens processing means for grinding a periphery of the lens,
the lens processing means including:
[0013] two lens rotating shafts for clamping and rotating the
lens;
[0014] holding means for sucking and holding the lens onto at least
one of the lens rotating shafts;
[0015] a rotatable grinding wheel; and
[0016] processing control means for controlling a rotational angle
of the lens rotating shafts and an axis-to-axis distance between a
lens rotation axis and a grinding wheel rotation axis;
[0017] lens conveying means for holding and conveying the lens,
which has been disposed at a storing position, to an intended
position; and
[0018] eccentricity measuring means for obtaining an optical center
of the lens held by the lens conveying means and obtaining an
quantity of eccentricity of the optical center with respect to a
predetermined reference position,
[0019] wherein the holding means holds the lens so that the lens
rotation axis is coincident with the reference position or the
optical center, and
[0020] wherein the arithmetic means obtains the processing data
based on the frame shape data, the layout data and the quantity of
eccentricity if the lens is held so that the lens rotation axis is
coincident with the reference position, and the arithmatic means
obtains the processing data based on the frame shape data and the
layout data if the lens is held so that the lens rotation axis is
coincident with the optical center.
[0021] (2) The eyeglass lens processing system as set forth in (1),
further comprising:
[0022] judging means for judging whether or not the quantity of
eccentricity obtained by the eccentricity measuring means falls
within a predetermined range.
[0023] (3) The eyeglass lens processing system as set forth in (2),
wherein the holding means holds the lens so that the lens rotation
axis is coincident with the reference position if the judging means
judges that the quantity of eccentricity is within the
predetermined range, and the holding means holds the lens so that
the lens rotation axis is coincident with the optical center if the
judging means judges that the quantity of eccentricity is outside
the predetermined range.
[0024] (4) The eyeglass lens processing system as set forth in (1),
further comprising:
[0025] selecting means for selecting a position with which the lens
rotation axis is made coincident by the holding means.
[0026] (5) The eyeglass lens processing system as set forth in (4),
wherein the selecting means selects a geometric center
corresponding position of the lens corresponding to a geometric
center of the eyeglass frame, and the holding means holds the lens
so that the lens rotation axis is coincident with the geometric
center corresponding position.
[0027] (6) The eyeglass lens processing system as set forth in (1),
further comprising:
[0028] cylinder axis measuring means for measuring a direction of a
cylinder axis of the lens held by the lens conveying means, wherein
the data input means inputs an angle of the cylinder axis included
in a prescription, and the arithmetic means obtains the processing
data, taking into account the direction of the cylinder axis and
the angle of the cylinder axis.
[0029] (7) The eyeglass lens processing system as set forth in (1),
wherein the lens conveying means conveys the lens to be positioned
at either of the storing position, a first predetermined position
located on a measurement axis of the eccentricity measuring means,
and a second predetermined position located between the lens
rotating shafts.
[0030] (8) The eyeglass lens processing system as set forth in (7),
wherein the lens conveying means conveys the lens so that the
reference position is coincident with the measurement axis of the
eccentricity measuring means when the lens is positioned at the
first predetermined position, and the reference position or the
optical center is coincident with the lens rotation axis when the
lens is positioned at the second predetermined position.
[0031] (9) The eyeglass lens processing system as set forth in (1),
wherein the data input means includes eyeglass frame measuring
means for measuring a frame shape of an eyeglass frame or a
template thereof.
[0032] (10) An eyeglass lens processing system comprising:
[0033] a data input unit which inputs processing condition data,
the data input unit including an input screen and an input switch,
the processing condition data including frame shape data of an
eyeglass frame to which a lens is to be fitted, and layout data
which provide a layout of the lens with respect to the frame;
[0034] an arithmetic unit which obtains processing data for the
lens based on the data thus inputted;
[0035] a lens processing apparatus which grinds a periphery of the
lens, the lens processing apparatus including:
[0036] two lens rotating shafts which clamps and rotates the
lens;
[0037] a rotatable grinding wheel; and
[0038] a processing control unit which is connected to the
arithmetic unit and controls a rotational angle of the lens
rotating shafts and an axis-to-axis distance between a lens
rotation axis and a grinding wheel rotation axis;
[0039] a lens conveying apparatus which holds and conveys the lens,
which has been disposed at a storing position, to an intended
position, the lens conveying apparatus having at least one arm;
and
[0040] an eccentricity measuring apparatus which obtains an optical
center of the lens held by the arm of the lens conveying apparatus
and obtains an quantity of eccentricity of the optical center with
respect to a predetermined reference position,
[0041] wherein the lens rotating shafts hold the lens so that the
lens rotation axis is coincident with the reference position or the
optical center, and
[0042] wherein the arithmetic unit obtains the processing data
based on the frame shape data, the layout data and the quantity of
eccentricity if the lens is held so that the lens rotation axis is
coincident with the reference position, and the arithmetic unit
obtains the processing data based on the frame shape data and the
layout data if the lens is held so that the lens rotation axis is
coincident with the optical center.
[0043] (11) The eyeglass lens processing system as set forth in
(10), wherein the data input unit includes an eyeglass frame
measuring unit having a feeler brought into contact with a groove
of the eyeglass frame, and the eyeglass frame measuring unit
three-dimensionally measures a frame shape of the eyeglass frame
based on an amount of movement of the feeler.
[0044] (12) The eyeglass lens processing system as set forth in
(10), further comprising:
[0045] a control unit connected to the data input unit, the
arithmetic unit, the lens processing apparatus, the lens conveying
apparatus, and the eccentricity measuring apparatus.
[0046] (13) The eyeglass lens processing system as set forth in
(12), wherein the data inputted by the data input means are
inputted into the control unit through a public communication
line.
[0047] (14) The eyeglass lens processing system as set forth in
(10), wherein at least one of the lens rotating shaft is provided
with a hole communicated through a suction tube to a pump unit to
hold the lens under vacuum.
[0048] (15) The eyeglass lens processing system as set forth in
(10), wherein the lens conveying apparatus includes two arms having
respective holes communicated through a suction tube with a pump
unit to hold the lens under vacuum.
[0049] (16) The eyeglass lens processing system as set forth in
(10), wherein the eccentricity measuring apparatus includes a grid
index of a predetermined pattern, an illuminating unit which
illuminates the grid index and the lens held by the arm of the lens
conveying apparatus by a substantially parallel beam of light, a
screen onto which an image of the thus illuminated grid pattern is
projected, and an image pick-up unit which picks up the thus
projected image of the grid pattern.
[0050] The present disclosure relates to the subject matter
contained in Japanese patent application No. Hei. 10-275031 (filed
on Sep. 29, 1998), which is expressly incorporated herein by
reference in its entirety.
BRIEF DESCRIPTION OF THE DRAWINGS
[0051] In the accompanying drawings:
[0052] FIG. 1 is a diagram illustrating a schematic external view
of an eyeglass lens automatic processing system in accordance with
the present invention;
[0053] FIG. 2 is a diagram explaining the configuration of a lens
conveying apparatus;
[0054] FIG. 3 is a diagram explaining the configuration of a distal
end portion of a first hand;
[0055] FIG. 4 is a diagram explaining the configuration of a distal
end portion of a second hand;
[0056] FIG. 5 is a diagram illustrating a measuring optical system
and a control system of an eccentricity measuring apparatus;
[0057] FIG. 6 is a diagram explaining a method of detecting the
position of an optical center of a lens LE;
[0058] FIG. 7 is a diagram explaining the configuration of the
processing apparatus;
[0059] FIG. 8 is a diagram explaining the configuration of the
distal end side of a chuck shaft of the processing apparatus;
[0060] FIG. 9 is a diagram illustrating a system configuration
concerning the order for lenses from an optical shop as well as the
acceptance of orders and control processing in the grinding process
at a processing center where the eyeglass lens automatic processing
system in accordance with the present invention is installed;
and
[0061] FIG. 10 is a diagram explaining a method of determining
processing data for correcting a portion of eccentricity of the
optical center with respect to a rotational axis L3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0062] Hereafter, a description will be given of an embodiment of
the present invention with reference to the drawings. FIG. 1 is a
diagram illustrating a schematic external view of the eyeglass lens
automatic processing system in accordance with the present
invention. The processing system includes a processing apparatus
100 for grinding an eyeglass lens; a tray conveying apparatus 500
for conveying trays 400, on each of which a pair of left and right
subject lenses are placed, to a predetermined delivering position;
a lens conveying apparatus 200 for holding the lens to convey the
lens between a tray disposed at the predetermined delivering
position and the processing apparatus 100; and an eccentricity
measuring apparatus 300 for detecting the optical center of the
lens held by the conveying apparatus 200 and for measuring its
eccentric position. Hereafter, the configurations of the respective
apparatuses will be described in order.
[0063] <Lens Conveying Apparatus>
[0064] First, the configuration of the conveying apparatus 200 will
be described with reference to FIGS. 2 to 4. Reference numeral 201
denotes a conveying base which extends in parallel to the
processing apparatus 100, the measuring apparatus 300, and the
conveying apparatus 500. An X-moving base 210 which moves in the
left-and-right direction (in the X-direction) is mounted on a pair
of rails 202 provided on the base 201. A ball screw 204 is
connected to a rotating shaft of a motor 203 attached to the base
201, and a connecting block 211 fixed to a base 210 is threadedly
engaged with the screw 204. As the motor 203 is rotatively driven,
the base 210 moves over the base 201 in the X-direction.
[0065] A Y-moving base 220 which moves in the back-and-forth
direction (in the Y-direction) along two guide shafts 212 is
mounted on the base 210. A ball screw 215 connected to a rotating
shaft of a motor 214 is threadedly engaged with a lower portion of
the base 220, and the base 220 moves in the Y-direction as the
motor 214 is rotatively driven. A holder 222 having a first hand
230 for sucking and holding an unprocessed lens LE and a second
hand 240 for sucking and holding a processed lens LE' is mounted on
the base 220 in such a manner as to be capable of swiveling, so
that the holder 222 is adapted to swivel 180 degrees via an
unillustrated gear by a motor 221 accommodated in the base 220. The
first hand 230 and the second hand 240 are held by the holder 222
in such a manner as to be movable in the vertical direction (in the
Z-direction) by motors 231 and 241, respectively.
[0066] A sucking base 232 is fixed to an end portion of the first
hand 230, and its distal end portion is formed substantially in a
U-shape, as shown in FIG. 3, so as to secure a range of passage of
a beam for measurement by the measuring apparatus 300 which will be
described later. Further, three suckers 233 projecting downward for
sucking the surface of the lens LE are provided on the sucking base
232 at equal intervals by using as a center a holding reference
axis L1 for the X-Y direction which the first hand 230 has. Each
sucker 233 has a suction hole, and the suction hole communicates
with a tube 235 through air passages formed inside the sucking base
232 and the first hand 230. The tube 235 is connected to a pump
unit 236 which effects the suction and delivery of air, and as the
pump unit 236 is driven and sucks, the lens LE is sucked and held
by the three suckers 233, while as the pump unit 236 delivers air
to the contrary, the suction and holding are canceled.
[0067] Meanwhile, a sucking base 242 is fixed to an end portion of
the second hand 240, and a flared sucker 243 projecting downward is
provided on its distal end side by using as a center a holding
reference axis L2 for the X-Y direction which the second hand 240
has, as shown in FIG. 4. This sucker 243 is also provided with a
suction hole, through which the sucker 243 is connected to a pump
unit 246 via a tube 245 in the same way as the first hand 230, and
the suction and holding of the lens LE' by the sucker 243 and its
cancellation are effected.
[0068] It should be noted that the mechanism for holding the lenses
LE and LE' may be arranged to nip the peripheral edges of the
lenses.
[0069] <Eccentricity Measuring Apparatus>
[0070] A casing 301 of the measuring apparatus 300 has a
substantially U-shaped side surface, and a measuring optical system
and a control system shown in FIG. 5 are disposed in the casing
301. In FIG. 5, reference numeral 302 denotes an illuminating light
source; 303, a collimator lens; and 305, a screen plate formed of a
semitransparent material (e.g., ground glass). Numeral 304 denotes
an index plate with a predetermined pattern formed thereon, and the
index plate 304 is supported by a supporting member 304a embedded
in the screen plate 305 so as to be located approximately 15 mm
above the screen plate 305. The index plate 304 in this embodiment
is arranged such that a grid index of black dots arranged at 0.5
mm-pitch intervals within the range of a 20-mm square by using as a
center an optical axis L0 of measurement by the collimator lens 303
is formed on the transparent glass plate. It should be noted that
this index plate 304 may be disposed on the light source 302 side
with respect to the lens LE which is mounted as shown in FIG. 5 at
the time of measurement. Numeral 307 denotes a CCD camera.
[0071] The lens LE is held by the first hand 230 which the
aforementioned conveying apparatus 200 has, and the lens LE is
disposed with its X-Y direction positioned such that the reference
axis L1 of the first hand 230 becomes aligned with the optical axis
L0 of measurement. In addition, the heightwise direction
(Z-direction) of the lens LE is set in such a manner as to assume a
predetermined heightwise distance with respect to the index plate
304.
[0072] The illuminating light from the light source 302 is
converted to a substantially parallel beam of light by the
collimator lens 303, and is projected onto the lens LE. The light
beam which passed through the lens LE further illuminates the index
plate 304, an image of the grid index subjected to the prismatic
action of the refractive power of the lens LE is projected onto the
screen plate 305, and this image is picked up by the camera 307. An
image signal from the camera 307 is inputted to an image processing
unit 311, and the processing unit 311 processes the obtained image,
detects the position of the index image, and inputs its detection
signal to a control unit 310. On the basis of the inputted
detection signal, the control unit 310 determines the position of
the optical center and the direction of the cylinder axis of the
lens LE.
[0073] A description will be given of a method of determining the
position of the optical center and the direction of the cylinder
axis of the lens LE on the basis of the image obtained from the
camera 307.
[0074] In the case where the lens LE is not mounted, since the grid
index of the index plate 304 is illuminated by the parallel beam of
light, the index image is projected as it is onto the screen plate
305. The control unit 310 stores in advance the coordinate
positions of dot images at this time which are detected by the
processing unit 311. If the lens LE is mounted, the dot image
located immediately below the vicinity of the optical center of the
lens remains at the same position irrespective of the presence or
absence of the lens, but the coordinate positions of the dots
images at portions which are not at the optical center move due to
the prismatic action of the lens. Accordingly, to detect the
optical center, a change in the coordinate position of each dot
image with the lens LE mounted with respect to the coordinate
position of each dot image with the lens LE removed is examined,
and the position from or toward which the dot images diverge or
converge as the center is determined. Namely, the center of this
divergence or convergence can be detected as the optical center. In
the example shown in FIG. 6, for instance, since the coordinate
positions of dot images P with the lens LE removed converge at P0
as the center, the coordinate position of this P0 can be detected
as the optical center. Even if the optical center is located
between dots, it suffices if the center of movement is determined
by interpolating the center of movement on the basis of the moving
directions of the dot images and the amounts of their movement.
[0075] According to such a method, the position of the optical
center can be detected accurately irrespective of the powers of the
lenses, and the amount of eccentricity with respect to the optical
axis L0 of measurement can be easily transformed into an absolute
coordinate.
[0076] In a case where the lens LE has cylindrical power, the dot
images move in a direction toward (or away from) a generating line
of the lens. Hence, the direction of the cylinder axis can be
similarly detected by examining in which direction the dot images
are moving with respect to the coordinate positions of the dot
images with the lens LE removed.
[0077] <Tray Conveying Apparatus>
[0078] In FIG. 1, the conveying apparatus 500 is constituted by a
belt conveyor 501, and the trays 400 on the belt conveyor 501 are
consecutively moved in the direction of arrow A. The conveyance of
the trays 400 is stopped at a predetermined position Q1 where the
acceptance and delivery of the lens LE (LE') are effected by the
conveying apparatus 200. An ID tag 401 on which the work number of
the pair of left and right lenses has been recorded is attached to
each tray 400, and the work number of the ID tag of the tray 400
stopped t the position Q1 is read by an ID tag reader 502.
[0079] <Processing Apparatus>
[0080] Next, a description will be given of the configuration of
the processing apparatus 100 with reference to FIGS. 7 and 8. The
processing apparatus 100 nips and holds the lens LE by means of an
upper chuck shaft 111 and a lower chuck shaft 121 which extend
vertically. The upper chuck shaft 111 is moved vertically by a
chuck upper portion mechanism 110 provided in the center of a
sub-base 102, and is rotated by a pulse motor 113 attached to a
holder 112. A lens holder 115 is attached to a lower end of the
upper chuck shaft 111 (see FIG. 8).
[0081] The lower chuck shaft 121 is rotatably held by a holder 120
fixed to a main base 101, and is rotated by a pulse motor 123 in
synchronism with the upper chuck shaft 111. A sucking member 130
having a rubber-made sucking portion 130a is attached to an upper
end of the lower chuck shaft 121 (see FIG. 8). The sucking portion
130a is formed in a flared shape whose central portion is concave,
and a suction hole is provided in a central portion thereof, to
which is connected a pump unit 135 for effecting the suction and
delivery of air through an air passage 131 formed inside the lower
chuck shaft 121. After the lens LE is set on the sucking member 130
by the conveying apparatus 200, the upper chuck shaft 111 is
lowered, and the sucking operation of the pump unit 135 is started,
thereby making it possible to hold the lens LE so that the lens LE
does not move during processing. When the lens LE is removed, its
suction and holding can be canceled by delivering air to the
sucking member 130.
[0082] The lens LE held by the upper and lower chuck shafts is
ground from two directions by left and right lens grinding portions
150R and 150L each having a group of grinding wheels 151 (a plastic
rough grinding wheel, a finishing grinding wheel having a beveling
groove, etc.) on its grinding-wheel rotating shaft. The grinding
portions 150R and 150L are bilaterally symmetrical, and are
respectively moved vertically and horizontally by moving mechanisms
provided on the sub-base 102.
[0083] In addition, a lens measuring portion 160 is accommodated on
a farther side in the center of the sub-base 102, and the measuring
operation of this measuring portion 160, the movement of the
grinding portions 150R and 150L, and the angles of rotation of the
upper and lower chuck shafts are controlled on the basis of data
inputted to the control unit 160 which will be described later. It
should be noted that since the configuration excluding the lower
chuck shaft portion is basically similar to the one disclosed in
Japanese Patent Unexamined Publication No. 97445/1996 (U.S. Pat.
No. 5,803,793) filed by the present applicant, reference is had to
be made to this publication for details.
[0084] Next, the operation of the eyeglass lens automatic
processing system having the above-described configuration will be
described with reference to a system configuration diagram shown in
FIG. 9. FIG. 9 is a diagram illustrating the system configuration
concerning the order for lenses from an optical shop as well as the
acceptance of orders and control processing in the grinding process
at the processing center where the processing system in accordance
with the present invention is installed.
[0085] An ordering terminal 10 and an eyeglasses-frame measuring
apparatus 11 are installed in the optical shop, and lens order data
including the data on the eyeglasses frame shape measured by the
apparatus 11, layout data of the lenses for the eyeglasses frame
(the pupillary distance of a client, the distance between geometric
centers of the eyeglasses frame, the height of the optical center
from the geometric center, etc.), the lens type, lens prescription
data (spherical power, cylindrical power, angle of the cylinder
axis), and the like are inputted online from the ordering terminal
10 to a host computer (hereafter, a host PC) 30 at the processing
center through a public communication line 20.
[0086] At the processing center, a work number is allotted to each
of a multiplicity of pieces of order data inputted to the host PC
30, and the work number is registered for the ID tag 401 on each
tray 400. A pair of left and right lenses LE of the specification
read out from the host PC 30 is set on each tray 400 on the basis
of the work number. At this time, each lens is set in such a manner
that an approximate center of each lens is located at a
predetermined point on the tray 400. Subsequently, the trays 400
with the lenses LE set thereon are consecutively placed on the belt
conveyor 501 of the conveying apparatus 500 (these steps may be
performed by the operator, but if an arrangement is adopted in
which the steps are automatically performed by a robot, further
automation can be realized).
[0087] When the setting of the trays 400 is completed, a control
unit 510 of the conveying apparatus 500 effects conveyance by
operating the belt conveyor 501, and when the tray 400 is brought
to the predetermined position Q1 for delivering and receiving the
lenses, its movement is stopped. At this time, the work number on
the ID tag 401 attached to the tray 400 is read by the reader 502,
and its signal is inputted to the host PC 30. The host PC 30
transmits data concerning lens processing corresponding to this
work number to the processing apparatus 100.
[0088] Further, when the tray 400 is brought to the position Q1,
the host PC 30 transmits an operation command signal to the
conveying apparatus 200. A control unit 250 of the conveying
apparatus 200 conveys the lens LE to a position of measurement by
the measuring apparatus 300 in the following manner by controlling
the driving of each motor. First, the base 210 and the base 220 are
moved so that the holding reference axis L1 of the first hand 230
is brought to the predetermined point over the tray 400 where one
lens LE is placed. Consequently, the optical center of the lens LE
is located in the vicinity of the reference axis L1 within the
substantially U-shaped configuration formed in the sucking base
232. Subsequently, the first hand 230 is lowered to the sucking
position, and as the suction by the pump unit 236 is started, the
lens LE (R) for the right eye is sucked and held by the three
suckers 233.
[0089] After the lens LE is thus held, the first hand 230 is
temporarily raised, and the first hand 230 together with the holder
222 is then rotated through 180 degrees to cause the first hand 230
to be oriented on the measuring apparatus 300 side. Subsequently,
the base 210 and the base 220 are moved, the lens LE is conveyed to
the position where the holding reference axis L1 of the first hand
230 is aligned with the measuring optical axis L0 of the measuring
apparatus 300, and the lens LE is positioned at a predetermined
height. This completes the disposition of the lens LE at the
measuring position.
[0090] When the disposition of the lens LE is completed, a
measurement starting signal is inputted from the host PC 30 to the
measuring apparatus 300, and the control unit 310 of the measuring
apparatus 300 determines the optical center of the lens LE by the
above-described method from the image of the index image obtained
from the camera 307, thereby obtaining eccentricity information
with respect to the measuring optical axis L0 (namely, this serves
as information on the eccentric position of the first hand 230 with
respect to the holding reference axis L1). In addition, in a case
where the lens LE has cylindrical power, the angle of the cylinder
axis in the state in which the lens LE is held by the first hand
230 is obtained. The information on the eccentricity of the optical
center (and the cylinder axial angle data) obtained by the control
unit 310 is transmitted to the host PC 30.
[0091] When the measurement by the measuring apparatus 300 is
completed, the conveying apparatus 200 conveys the lens LE held by
the first hand 230 up to the processing apparatus 100. After the
lens LE is placed such that a rotational axis L3 of the chuck shaft
of the processing apparatus 100 and the reference axis L1 of the
first hand 230 are aligned with each other, the lens LE is set on
the sucking member 130 by the lowering operation of the first hand
230. Subsequently, the suction on the first hand 230 side is
canceled, and the rear surface side of the lens LE is sucked onto
the sucking member 130 by the sucking operation of the pump unit
135, thereby lowering the upper chuck shaft 111. As a result, the
lens LE is chucked in the state in which its state at the time of
eccentricity measurement is maintained. The first hand 230 which
canceled the suction of the lens LE is moved away from the
processing apparatus 100.
[0092] It should be noted that when the lens LE is set on the
sucking member 130, if the optical center of the lens LE is offset
substantially from the rotational axis L3 of the chuck shaft, there
are cases where the accuracy of the processing shape is affected.
As a countermeasure against this problem, it suffices if the host
PC 30 determines whether the amount of eccentricity of the optical
center obtained from the measuring apparatus 300 is within a
predetermined range (e.g., 10 mm), and if the amount of
eccentricity exceeds this range, the lens LE may be set by
controlling the movement of the first hand 230 so as to correct
that portion of eccentricity.
[0093] When the chucking of the lens LE is completed, the host PC
30 inputs the eccentricity information obtained by the measuring
apparatus 300 to the processing apparatus 100 to start processing.
The control unit 160 of the processing apparatus 100 determines
processing data (this processing data may be obtained on the host
PC 30 side) in which the portion of eccentricity of the optical
center with respect to the rotational axis L3 and a portion of
offset in the angle of the cylinder axis are corrected, by
incorporating the eccentricity information into the frame shape
data, the layout data, the cylinder axial angle data of the lens
prescription, and the like which have been inputted earlier.
Namely, as shown in FIG. 10, the radial information (rn, 0n) on the
frame shape data using the geometric center F.sub.0 of the frame
shape as a reference is subjected to coordinate transformation
using the rotational center G.sub.0 of the lens as a reference on
the basis of the coordinate position of the optical center O.sub.0
determined from the layout data with respect to the geometric
center F.sub.0 as well as the coordinate position of the rotational
center G.sub.0 of the lens determined from the eccentricity
information with respect to this optical center O.sub.0, to thereby
determine new radial information (r'n, .theta.'n). In addition, the
angle of the cylinder axis is determined by being transformed into
radial information in which the frame shape is rotated about the
optical center O.sub.0 so as to correct the offset portion of the
detected axial angle with respect to the axial angle data in the
prescription.
[0094] Subsequently, on the basis of the determined processing
data, the control unit 160 effects processing while controlling the
rotational angle of the lens LE and the movement (axis-to-axis
distance between the chuck shaft and the grinding wheel shaft and
the axial position of the rotating shaft of the grinding wheel with
respect to the lens LE) of the grinding portions 150R and 150L with
respect to the lens LE. As a result, the lens LE is accurately
processed to an intended shape without using a conventional cup as
a processing jig.
[0095] It should be noted that, at the time of setting the lens LE
at the position of chucking by the chuck shafts 111 and 121, in
addition to effect the setting as described above, the portion of
eccentricity of the position of the optical center may be corrected
by the control of X-Y movement of the first hand 230 (namely, such
that the rotational center and the optical center of the lens are
aligned with each other), or the frame center processing may also
be effected such that the geometric center of the eyeglasses frame
is aligned with the rotational center of the lens.
[0096] With respect to the rotational center of the lens, whether
the reference axis L1 of the first hand 230 is to be aligned,
whether the optical center of the lens LE is to be aligned, or
whether the geometric center of the eyeglasses frame is to be
aligned may be selected in advance by the host PC 30. Further, the
host PC 30 may make the aforementioned determination and selection
on the basis of the frame shape data and the layout data so that
the processing shape will become stable.
[0097] In addition, in a case where a lens with an extremely
eccentric layout or with a narrow vertical width is to be
processed, if the lens is set as it is, there are cases where the
chuck diameter of the processing apparatus 100 (the diameters of
the sucking member 130 and the lens holder 115) projects outside
the frame shape, causing interference in processing. In such a case
as well, it suffices if the lens is set in such a manner as to
avoid the interference in processing by off setting the position of
the lens chuck by controlling the X-Y movement of the first hand
230. For instance, a selection is made as to which of the
aforementioned positions the lens is to be set.
[0098] In the case where the lens LE is thus set by controlling the
X-Y movement of the first hand 230, the processing data is obtained
on the host PC 30 side, and control of the movement is effected by
the host PC 30.
[0099] Upon completion of processing of the lens LE, a processing
completion signal is transmitted to the host PC 30. The host PC 30
causes the conveying apparatus 200 to operate again. The processed
lens LE' is conveyed by the second hand 240. The second hand 240 is
swiveled to the processing apparatus 100 side, and after the upper
chuck shaft 111 on the processing apparatus 100 side has been
raised, the second hand 240 moves to the position where the holding
reference axis L2 of the second hand 240 is aligned with the
rotational axis L3 of the chuck shaft. Subsequently, the suction on
the lower chuck shaft 121 side is canceled, and the lens LE' is
sucked and held by the sucker 243 of the second hand 240. After the
lens LE' is held, the lens LE' is conveyed by the movement in the
X-Y-Z direction and the swiveling motion of the second hand 240,
and is returned to the tray 400.
[0100] When the processing of one lens is finished, the other lens
is successively conveyed in a similar procedure, and processing is
effected automatically. Thereafter, the conveyance and processing
of the lens placed on each tray 400 is repeated automatically.
[0101] As described above, in accordance with the present
invention, it is possible to effect processing accurately while
managing the relationship between the rotational center and the
optical center (and the angle of the cylinder axis) of the lens on
the processing apparatus side without using the cup as a processing
jig. As a result, the steps of the operation of inscribing a marked
point on the lens by using the lens meter and the attachment and
removal of the cup are made unnecessary, and automatic processing
which saves the trouble of the operator can be effected very
efficiently.
* * * * *