Anti-reflection coati n g

coating
Anti-reflection
OW TechnicalEditor Tonytarratt
The supply of coated lenseshas now becomean everydayoccurrence,with the process
when pr oducedfr om
lenses- par ticular ly
n o w b e i n g a p p l i e dto mo re a n d mo re spectacle
coatingsfur theL it shouldbe noted that the w or d
h ig h i n d e xm a te ri a l .B e fo red i scu ssing
'coatings'now coversa far wider range of applicationsthat was previouslythe case.
been made aware of these added
I n the ophthalmic context.'coatings'
I originally meant only anti-reflection benefits.
we now have to
I coatings.However,
I consider:Hard coatings,anti-reflec- Formationof reflections
If we consider the lens and eye in comtion coatings, tinted coatings (mirror
bination, we can see that they have
coatings) and hydrophobic coatings.
three external surfaces between
Sometimes these are supplied indithem - front and back surfaces of the
vidually, but they can be applied to the
lens and the surface ofthe cornea. Uslens surface in successive layers, or
ing this model, it can be shown that
even in one continuousprocess.
'combined coating' is
four different types of reflections are
This type of
formed, depending on conditions.
now most evident when we are talking
These reflections are:
about hard and AR coating. Many
coatings now combine the properties
1. Frontal reflections - some of the
of a hard and anti-reflection coating,
light incident on the front surfaceis
sometimes with the added advantage
reflected back towards an observof a hydrophobic or clean coat final
'top
er - therefore degrading the coslayer - commonly known as a
metic appearanceof the lens(es).
coat'.
An example of this type of reflection
is that produced when a spectacle
AR coating and reflections
wearer is in front of a television
AR-coating on lenses is used for two
principal reasons- to improve the opcamera - the very bright studio
lights are reflected from the spectatical performance and/or to improve
cle lenses,thus obscuringthe wearthe cosmetic appearance.These are
er's eyesbehind the lenses.
to some extent the same thing - if we
improve the optical performance of
2. Baclnvard reflections - some of
the lens, we are quite likely to improve its appearance.The prescriber
the light from behind the wearer
probably
is reflected from the back lens
the
will
consider
/dispenser
surface onto the eye. This causes
6ptical aspects of applying such a
disturbing refl ections, particularcoating whilst the end user - the
ly in dusk conditions or when
wearer - will see the final effect from
driving at night, e.g.,where ambia cosmeticpoint of view - a reduction
ent light levels are low and there
in surface reflections which will enis a bright light source such as the
hance the cosmetic acceptability of
headlights from a car behind the
the lenses, thus making them more
driver.
attractivewhen being worn.
The wearer will not necessarily re3. Internal reflections - light is realise that the improved appearancealflected between the two lens surso means that there will be fewer ghost
faces, internally. This can be
reflections and an increase in transmitcausedby light from any direction.
ted light, with the resultant improveIt is the cause of the multiple
ment in contrast and visual acuity. Of
'rings'
seen around the edge of
course, if the dispenser has done a
good job, then the user will have also
some high minus lenses.
10
. hilp:llwww,oplicol-woild.to,uk
4.Corneal reflections - caused by
light being reflected from the surface of the cornea and then interactingwith the lens surfaces.
The last three reflections cause
ghost images and can lead to lowering
ofvisual acuity, due to blurring and reduced contrast. They therefore diminish the optical performance of the lens.
Reflectionnumber one would appearto
be only a cosmetic problem, as it results in difficulty for an observer due to
the frontal reflections. However, it
does reduce the amount of transmitted
light, which in turn reduces the efficiency ofthe lens.
Surfacereflections
The ability to reduce the loss of light,
caused by these reflections, has become more and more important as the
dispensing of high index lenses has
shown a continued growth. This is because the surface reflections increase
along with an increase of the index of
the material.
This increase in surface reflectivity
is solely a function of the material index and cannot be affected by material
design or composition, as can the
Z value (orAbb6 number) and material density / weight. The amount of
light reflected from a lens surface is
given by the formula:
12
l n ' -n l
sr=l ,
I
+nl
tn
where
sr: surface reflectance
n' = refractiveindex of lens material
n = refractive index of the substance
in which the lens is immersed for spectaclesthis is air and a = 1
from this formula,it canbe seenthatas
the materialindex rises, i.e. [z'] becomes larger, [sr] will also increase'
This meansthat the amountof surface
reflectionwillrise.
Using the aboveformula and some
of the standard indices, which are
widely available,we can calculatevaluesfor sr andthesecanbe conveniently convertedinto percentageloss at
eachsurface:
n
1.498
t.523
1.604
1.660
t.706
1.800
1.803
1.900
n'-n
0.498
0.523
0.604
0.660
0.706
0.800
0.803
0.900
does not cause any problem for the
wearer - although ghost images can
cause difficulty in certain conditions.
However, we can see, from the table,
that the reduction in transmitted light
for the higher index materials does
becomeincreasinglylarge.
A loss of much over 10 per cent be
comes questionable and over 12 or 13
per cent, would be considered unacceptable to most users. In fact, the
= per centloss
sr
3.974
0.0397
4.297
0.0430
5.380
0.0538
6.156
0.0616
6.807
0.0681
8.163
0.0816
8.207
0.0821
9.631
0.0963
n'+n
2.498
2.523
2.604
2.660
2.706
2.800
2.803
2.900
As we haveto considera lenstherewill higher figuresshownin the table 15
be light lostat both surfaces,but this is to 18percentreductionsin transmitted
not just doublethe figure lost at the light, are equivalentto the sortsof levfirst surface.If we take the incident els found in cosmetictints appliedto
light at the first surfaceas 100per cent manylensesthesedays.
In additionto this high light loss,the
and consideringthe light loss for a
of reflectionsfor the lens
appearance
glassofn=l.800,wehavethefollowing:
Incident light
Percentlossot lst surfoce(S.l 63 per centof 100)
light ironsmittedofterfirst surfoce
Percenl lossot 2nd surfoce(8.163 per centof 91 .837)
Lighttronsmittedihroughlens
r00.000
-8.r 63
91.837
-7.497
84.340
oratotallossof15.66percent-assum- surfacesis disturbingto the wearer
ing a 'clear'lens materialand reason- due to the higher level of reflectance,
ably thin lens,where there is little or which meansthat ghost imagesetc.
no light loss due to absorptionby the aremorenoticeable.
For thesereasons,it is advisableto
materialitself. Extra thick lenses,or
provide
anti-reflectioncoatingfor all
a
lower
thosewith a tint, will exhibit
with an index over,say,1.66
materials
overalllighttransmittance.
Ioble
jor manufacturers to supply their high
index and very high index lenses with
an AR-coatingas standard.
See graph for the reflectance curve
of a high quality multi-AR coating
(courtesy of Satisloh). This shows the
reduction of reflections to an average
of about 99.5per cent.
MultiquartzZ-P
4
Ro/o
1
0
400
\ 450
500
550
600
650
700
Wavelengrth (nm)
Reflectoncegroph for Muliiquorlz cooting produced
by Sotisloh showing 99.5 per cent overoge
Why coatingswork
are causedby someof the
Reflections
incidentlight beingreflectedby the surfacesof the lens material,theoretically
when the light doesnot strike the lens
surfaceat right angles.This, aswe saw
above,causesseveraltypes of reflection.
If we interposea transparentlayerbe
tweenthe light striking the lenssurface
and that surface,we causetwo reflections - the first from the surfaceof the
layerandthe secondfrom the surfaceof
the lensitself.If the thicknessof the layer is made% of a wavelengththick, the
'out of phase',
two reflectedrayswill be
by % wavelength.This is becausethe
ray,which is reflectedfrom the lenssurface,hasto travelthroughthe layer and
then back again,- i.e., twice the distance.
t: Lossesdue io reflection for o ronge of moieriols
Moteriol
cR39
SoectocleCrown
lndex
.498
523
light loss
Lighl loss
Totol per cent
Per cenl of initiql
lsl
2nd
loss
light tronsmitted
surfqce
sur{qce
3.97
4.30
3.82
4 . 1I
7.79
8.41
through lens
92.21
9r . 5 9
Polycorbonoie
568
4.89
4.65
9.55
Mid lndexCrown
604
f,.JJ
5.04
r0 . 3 7
90.45
89.63
HighlndexPloslic
660
6.16
s.78
I 1.93
88.07
DenseFlintGloss
706
.800
.803
.900
6.8r
13.15
86.85
8 . 16
8.21
6.34
7.50
7.53
4
15.7
84.34
84.26
9.63
8.70
18.34
81.66
DenseFlintGloss
DenseFlintGloss
DenseFlintGloss
It is normallyacceptedthat the light
loss for CR39 and spectaclecrown
'r5.66
As the two rays are out of phasebYa
andthey are a mustfor 1.8and above.
It is. of course,now normalfor all ma- Yzwavelength,they will be mutuallyde
OW May 2O1O.ll
subsequently (in
the mid 1950's)for
high index glass
spectaclelenses.
However, there
are now several
variations on the
original concept
and the process
can now be classified into the followingmethods.
Most
dependonthe dep
Fig. 2: A schemoticshowingthe structureof o typicolhigh quolity
muhi-ARcooting - courlesyof Leybold
osifionon the lens
surface of one or
more alternating
low and high refractive index layers of metal oxides.
lNote: the following descrip
tions give a general idea of the coating processesinvolved - they are
not intendedto be
definitive- but only to actasa guide.
Different
vaiastructive, i.e., they will eliminateeach tions of the processesare availableaccordingto the particular requireother,thusdesfoying the reflection.
As this mutual desfuction takes mentsof the end user and the equip
placefor onewavelength,the resulting mentavailable].
reductionin reflectionswill not be comprocess:
plete.To overcomethis problem,multi- 1. Theoriginalevaporation
layer AR coatings were infoduced. Under this process, the lenses are
These are far more effective,eliminat- placedin a chamber,which is capableof
ing reflectionsovera muchwider range havingthe air evacuatedto a very low
of the spectrum.Final transmissionsof pressure,thus producinga high vacuup to about 99.5 per cent can be um.The chamberandthe materialto be
used for the coatinglayer(s) are then
achieved.
SeeFigures1 and2 for imagesshow- heated - in the case of the coating
iti!1 the effect of a good hydrophobic chemicals,to avery high temperahrre.
This causesthe chemicalsto vaporise
topcoat (1) and a schematic(2) showing a typical structure of a multi- into a gaseousstate.At the sametime
layer coating - both courtesy of the lens surfaceis chargedelectrically,
with respect to the remainder of the
leybold.
chamber.As the chamberis at a high
vacuum,thegasmolecules
cantraveldiManufacture
AR coatings,initially introduced only rectly from the heating element onto
for high index glassmaterials,cannow the lens surface,being attractedto this
be suppliedto virtually all ophthalmic by the electricallychargeddifferential
lens materials,both glass and plastic. betweenthe lensandchamber.
To achievetheseresults.the earlier
Traditionallythe methodof applyingan
ARcoatinghasbeenby vacuumdeposi- coatingmachineshadto achieveavery
tion andthis techniquehasbeenused high temperahrre,in order to evaposince its introduction by Zeiss in the rate the chemicals.This temperature
1930's- initially for opticalsystems,but would have damagedthe plasticslens
Fig. l: Two imogesshowingo lenswifhour(L)ond with high
super-hydrophobic
cooiing(R)- courtesyof Leybold
12 . hW,I lvyv,optictl-Yotld,co,ul
materials.Howevera newmethodwas
introducedwhich overcamethis problem.
2. 2ndvariation- usinganelectron
beamgun:
Thesemachinesusea differentmethod
of evaporation.This is achievedby
meansof an electronbeamgun,which
fires a chargedbeamat the chemicals,
achievingevaporationat a much lower
temperature.This, coupledwith the
use of sophisticatedmicroprocessor
control of pressure,temperahrreand
evaporationrate,has enabledmanufacturersto producemachineswhich can
depositsingle and multi-layercoatings
on virtually anylensmaterial.
3. Magnetron
sputtering
A third methodof depositionis that of
sputtering.In this processthe material
to be deposited(in the form of a fixed
targetwithin the vacuumcoatingchamber) is erodedby energisedparticles
(normallypositiveions) striking its surface- the rate at which this takesplace
beingcontrolledby magneticfieldsproducedby magnetronswithin the chamber.The resultantmaterialejectedfrom
the target,beingdepositedon the lens
surfaces.(Seeendnote1).
Again,this methodcanbe carriedout
at a much lower temperafure,making
the processsuitablefor all typesof lens
substrate.
polymerisation
4. Plasma
Polymerisationis basicallya chemical
reaction where molecules (the
monomers)arejoinedtogetherto form
the polymel which then consistsof
largerepeatedchainsof molecules.
Plasmapolymerisationis a process
wherethe chemicalsareevaporated
into
a gaseousstate (gasphasemonomers)
within the vacuum chamber and are
thenassistedbythe plasmaintoforming
a polymer,which is depositedonto the
subsfatesurface.This typeofprocessis
used, for example,to depositthe hyasthetoplayerofan
drophobic'coatings
ARcoatedlens.
5. Spincoating
This is the latestmethodto cometo the
market and is basedon spin hardcoat
techniques,using sol-gel technology.
For afull explanation
of the technology
'[nw
cost, cominvolved see the article
pact AR coating machines for Rx labo
ratories' by Dr Peter Wilkinson in the
March 2010 issue of Orncer Woru-o,
pp12to14.
The main benefit of the method,
apart from cost considerations,is said
to the better match of the AR coating to
the lens substrate. Polymers such as
CR39 and polycarbonate, are malleable, i.e., they are flexible when
placed under stress.Their dimensions
can change significanfly with temperature. On the other hand normal AR
coatings using'ceramics' such as silica, are brittle and easily craze under
stress.They have little ability to flex, or
change dimensions,with temperature.
This meansthatthe lens substratemay
alter its shape with change in temperature, whilst the coating may not, thus
resulting in crazing.
The coatings applied by the sol-gel
process (see Chemat review in this article) are made up of a super hydrophobic polymer matrix embedded with
nano-sizeceramic particles. The polymer matrix has the ability to flex,
matching thermal expansion and providing a chemical bonding and hydrophobicity, whilst the ceramic particles give the refractive index required
to produce an AR or mirror coating.
vs Oleophobic:
Hydrophobic
When the first easy care top coatings
were introduced back in the late
1980's, they were loosely referred to
as hydrophobic top coatings. Hydrophobic literally means'water-repellent'
and the quality of a hydrophobic
Otherconsiderations
pieces
has traditionally been
coating
informatop
of
The following two
by
the contact angle of a
measured
tion are supplied courtesy of Satisloh
a lens. A higher conof
water
on
drop
and are taken from their coating
processguide.
tact angle (roundness of the drop of
Top coating options: Ease-of-care water) equates to a better hydrophois perhaps the most important feature bicity. Traditional hydrophobics typiofAR coated lensesto the averagecus- cally have contact angles in the range
of.97-104degrees.
tomer. A naked AR coating is by nature
will
The newest generation of hydropho
rough and hydrophilic, meaning it
bic
top coatings, referred to as super
attract dirt and water and will be diffiproblem
have a contact angle in
hydrophobics,
even
cult to clean.Making the
10G112
degrees.More imthe
range
of
worse is the fact that an AR coatedlens
portant
its
ability
to repel water is
than
will show the dirt more than a non-AR
ability to repel
a
super
hydrophobic's
coatedlens.
referred
to as oleofingerprints,
Fortunately, coating technology has oil and
phobicity.
fingerof
removing
The
ease
advancedrapidly and there are a numgeneration
prints
of
newest
from
the
ber of new chemical options available
in
AR
resulted
in
a
boom
AR
lenses
has
to make AR coating easierto clean than
penetration of the US ophthalmic lens
ever before. These chemicals are ap
(hence
plied on top of AR
market. (Seeentry for Cotec for measthe term'top
urement of contact angle).
coating') inside of a vacuum chamber.
SUPPLIERS
materialfor review.Fulldetailsof their
havekindlypresented
Thefollowingcompanies
orwebsites.
productsand processes
canbe foundfrsm their catalogues
Chemat
wwwchemalux.com
U K- e m a i l :
peterwlk@btinternet.com
Holdersof a world-widepatenton the
applicationof multi-layerAR coating
techniquesusing sol-geltechnology,
Chematare the only companyat present to offer machinesfor this purpose.
(See previous note regarding the
process,describedin the articleby Dr
PeterWilkinsonin the Marchissueof
C H EM A L U X ' '
olv).
Based in California with offices in
Europe and China, they currently offer three sizes of the machine with capacities from 12 pairs to about 120
pairs per shift. This makes the machine (and technology) eminently
suitable for the smaller laboratory
that has a need to coat a small number
of lenses per day, or for the large organisation that has the need to coat
1 4 o 1111p1
I lywy,optinl-world,rc,uh
Chemolux 300 from Chemot - showing ils excellenl
smoll fooiorinl
small numbers of specials,such as
colouredmirror coatings,where the
use of vacuum coating machines
wouldbeuneconomic.
Three machinesare on offer. The
Chemalux 100 multi-functionalspin
coatingsystemis a table-topunit and
is capable of doing AR coatings,
scratch resistant coatings, mirror
coatingsand/ or easy-cleancoatings
in a compactspace.It is designedto
enableretailersandsmalllabsto offer
premiumcoatingsin-housewith an affordableinvestment.
Throughputis up to 12 pairs of AR
coatingsper day,with a coatingcycle
of 7 minutesper side.Dimensionsof
the compactunit are 23in " 27in "
2lin.
The next machinein the range is
the Chemalux300.With a capacityof
up to 35 pairs of AR coatingsper day,
this machinehas a very small foot-
I
I
I
t
print of only 25in , 25in x 60in high,
making it easy to install in even the
smallest laboratory. The 300 can produce, AR, flash mirror and EZ-Clean
coatings, with a processing time of
about one hour (coating cycle only 5
minutes per two sides). The unit is fully automatic, with touch screen operation and has a simple and reliable
electromechanical structure, making
itvery easy to maintain and repair.
The PLC (microcomputer) control
system integrates automatic high
pressure water washing with precise
multi-layer spin-on coating. The machine applies the AR coating two surfaces at a time, pair by pair. Flash mirror coatings can be applied with a simple touch of the command screen.
largest machine in the range, the
Chemalux 600, is a multi-station coating system that cleans and coats eight
lenses simultaneously, making it suitable for those laboratories who require a greater output capacity. It is
designed to produce scratch resistant
coatings, AR coatings, plus flash mirr or and EZ-cleancoatings.
It is controlled by a microprocessor,
using a colour touch screen panel for
ease of operation. The system is capable of accepting a fully automatic lens
loading and unloading mechanism to
make it an inline fully automatic coating system. Throughput is up to 15
pairs per hour, with a coating cycle of
8 minutes per side. As would be expected, the machine has a large footprint- 53 in x 40 in ^72in.
Chemalux also produce three
pieces of peripheral equipment of interest to the coating laboratory. The
first is the Chemalux TC-2 Super hydrophobic coater. This is able to deposit the super-hydrophobic layer onto any shape of lens - uncut, edged or
even still in the frame. This has the
benefit of allowing the lens to be
edged first, thus avoiding the problem
of slippage whilst edging. It is also
possible to re-apply a hydrophobic layer to a lens once the original coating
has been worn out. Process cycle time
is 7 minutes, with a capacity of up to 3
pairs oflenses per cycle.
The second machine is the iMirror
TintCoater, specially designed for fast
production of quality flash mirror
coating on tinted lenses within the op
16 . hllqI lY,nmptktl-vorld,co,ul
The Durolesl conlocl ongle meosuring system from Coiec
tician's practice. The system also does
normal lens tinting. The bench-top
machine offers fast heat-up time and
has an overflow channel to catch spilt
chemicals. Its coating curer drawer
holds up to four pairs of lenses for
thermal curing at temperatures up to
250'C. The coater module has a spin
speed of 0 to 150 rpm and a coating
'universal'
uring device. The
Duratest
system is specially designed for the
ophthalmic industry and offers easy
handling, precise measurements and
data storage, which allow the user to
controlthecontactangleonbothcoated and uncoated lenses.
Special quality control for ultrahydrophobic coatings, such as Duar-
cycletime of 5 to 10minutes.
alon,is possiblewith precisemetering
Final piece of equipment in the current range is the Chemalux GPS spectrophotometer. The instrument can be
coupled with the Chemalux coating
'tune'
the colour of the resystems to
sultant coatings. It is used to monitor
and control the coating operation (AR
and mirror) to ensure colour consistency during the coating cycle, adjusting operating parameters if necessary.
In addition, the GPS is a useful tool for
tuning the system to make a desired
colour lens by lens.
The spectrophotometer is based on
fibre optic technology coupled to a reflectance probe and fibre optic light
source; the device measures the reflection of the coating and the resultant reflection spectra is used to determine the colour of the coating. The
CCD technology used is combined
with the reflection probe to produce
reflection spectra simultaneously.
Measurementtime is 30 secondsand
the device covers a range from 400 to
800nm.
precision of 0.1'. The device is designed for use within the laboratory or
in production control. Features of the
system include:
tr Fast and easy control of contact
angle and surface energy
I Intuitive software providing
different measuring methods
tr Easy documentation of results in
protocols and video image
I Optional use with laptop or PC
tr High quality optics for excellent
video images
E Economic pricing whilst
retaining all necessary functions
The Duratest is fully automatic
when measuring the contact angle,
detecting the drop surface interface
automatically by image processing.
Additional options allow the manual
setting of the measuring points and
the completely manual measurement
ofthe contact angle. The software also
contains an evaluation module for
measuring surface energy by comparing contact angles of two known measCotec
uring liquids.
www.cotec-gmbh.com
Time dependent contact angle
Within their large range of coating
Cotec measuring with freely selectablecycle
equipmentand consumables,
offer the Duratestwhich representsa times and detection of roll off angle
newgenerationofcontactanglemeas- are also available.
Benefits of the system are stated to
be easy handling, precise measuring,
flexible use, software supported, easy
data management, live video image
and an economicprice.
DACVision
www.dacvision.com
DAC Vision offer a variety of generic
high-purity chemicals, hydrophobic
and super-hydrophobic
top coats,and
an assortmentof spareparts and consumables for vacuum deposition
equipment.InadditionDACalsoengineer advancedprocessesto improve
and developtreatmentslike Greenof
AchromaticAR with hydro or superhydro top coat.
[,ens treatment chemicalsinclude
silicon dioxide, titanium and zirconium oxides (grey and white), magnesium fluoride, silicon and chromium
siliconmonoxides,plusaluminiumoxideandindiumtin oxide.
Top coat treatment can be customised to fit chamber size and desired coating thickness.These treatmentsare smoothandabrasionresistant over time and provide excellent
hydro and super-hydro properties.
DAC list one hydrophobic'pill' and
threesuperhydrophobicsi
I
Boxer ond BoxerPro from Leyborq
Leybold
www.leyboldoptics.com
The company tcybold have been
dealingwith all aspectsof vacuum
technologyfor over 150years.Ernst
Leyboldand Wilhelm Carl Heraeus
laid the foundationsfor the present
day company.Very early on these
two inventors dealt with the potentials of vacuum technologyand in
1967the companiesof l,eyboldand
Heraeusmergedto form the precur. SHP040- coats40lenssurfaces
sorof today'sLeyboldOpticsGmbH.
with an 8nmthick top coatlayer
Followingon from the long tradi. SHP060- coats60surfacesto
tion of dealingwith lenscoating,Leysamethickness
bold now offer an extensiverangeof
. SHP100
- coats100surfacesto
coating equipment, including masamethickness
chinesand systemsfor '3D coating'
. SHP150
- coats140surfacesto
(items with complex geometries)
samethickness
and 'Web coating' (flexible substrates, including such things as
Three AR processesare offered packagingfilms).
, Diopside- green AR formula with
For the ophthalmicmarket, their
top hydrophobic layer, Native rangeincludesthe Boxersystem,suitgreen with super-hydrophobictop ablefor Rx andstockproductionquanlayer and Delight - achromaticAR tities.A superiorion sourcetechnoloformulawith top super-hydrophobic gy, powerful vacuum pump, single
layer.
quartz monitor,high-powered
electron
Consumables
listedinclude,boats, beam evaporatorin the centre of the
liners (bothin molybdenum)and fil- chamberand a highly efficient'Meissamention guns and kits. A range of ner trap' (Seeendnote2) arecombined
crystals(gold,silverand alloy),plus to give optimum performance.
a rangeof spareparts are alsolisted
This medium-sized coating solu.
in the catalogue.
tion guarantees easy handling, as
DAC canalsooffer a rangeof serv- well as simple maintenance;it offers
ices, including trouble shooting, a wide range of manufacturing
maintenance,engineering,training processes, e.g., it is capable of proandcoatingprocessdevelopment.
ducing broadband AR coatings on
mineralglassor absorptioncoatings
on sunglasslenses.The monolithic
design allows for a larger coating
areawith reducedfloor space.
The Boxer is availablein three versions,eachwith a differentcapacity:
BoxerLight- 110/130pairs
per
eighthours
Boxer-220/ 230pairspereight
hours
BoxerPro- 250/260pairsper eight
hours
Featuresandbenefitsinclude:
Cubiccoatingchamberwith
straightsidesensuring:
Easymaintenance
Optimisedcoatinggeometry
Quickremovalof chambershield
Simpleclick fixing of substrate
carrier
Multiple hardwareoptions
including:
Heatingsystemfor mineral
substrates
Mark II or LION ion source
Pumpupgrades(Turbo,Roots)
A second systemfrom kybold is
the CCS Series- a designthat can
grow alongside the expansion of a
business, allowing, as it does, for
physical spaceand production adaptations. To achieve this, new components can be added to the machine to
OW May 2O1O.17
increasevolume. Featuresandbenefits of the systeminclude:
tr Fully automatedprocess
n Easyand comfortablemachine
handling and operation
D Easymaintenance
n Compactfootprint
! Ergonomicchambershieldings
n Quick pumpdown time
! Modificationof process
parametersto customer
requirements
! MultiJayer AR coatingfor both
organic and mineral substrates
! Remoteanalysisvia modemand
datarecording
The CCSsystemis availablein three
versions - CCS ljsht" cawcl;V 4*72
pairsper eighthours,CCSLight P (64to
96 pairs) and the CCS PRO (726/182
pairs).Eachof thetwo smallermachines
canbe upgradedbysimplyaddingcomponentsto increasecapacity.
The Syrusfimily from I-eyboldoffers
a hrghly efficient system for coating
largebatches.In classicalmassproduction, asin k laboratories,the Syrusofthat
fersanexceptionalcost-benefitratio
is achievedby anintelligentmodularde
slgn. In ion-assistedcoatingas in conventionalsingle or multiJayerproces$
es,this systemis saidto offer optimum
qualityataneconomiccostperlens.
This systemis availablein two versions - Syrus III with a capacity of
450/550pairs per eight hours and the
Syrus 1350.witha capacityof 650/800
pairs.
SL501 comprises a multistage
cleaning process,followed by thermal cured dip coating with a primer
stagefor speciallens materialssuch
as polycarbonate.Two different lacquers can be used for index matching.
Following the success of the release of the High Index K process,
Satisloh'sR&D department has developeda new process- Ioncote K+
for high index and 1.5 index substrates. This is said to outperform
majormarketbenchmarks.The main
Satisloh
characteristicsof the new process
www.satisloh.com
Combining the 120 years of experi- are increased abrasion resistance,
ence of SatisVacuumand Loh Opti- together with an improved top coat
cal machinery, Satisloh, headquar- (Satin)life span.
tered in Switzerland, supply complete solutions for ophthalmic and
The Satisloh high performance
precision optical manufacturing,in- lens coatingconsistsof:
Dip coatlacquer- DN1500and
cluding vacuum coating equipment
DN1600
and accessories.The companyhas a
AR coating- Ioncote K+ - with
worldwide presencein 19 countries
antistaticpropertiesand long life
through more than 13 subsidiaries
cleanability
and 10agents.
Superhydrophobiccoating- Satin
The latest offering from the company, showcasedat Mido 2010,is a
Over the last forty years, Satisloh
new high index process- IoncoteK+
and the new cleaningand hard coat- have developed many AR coating
ing system SL501. This systemfits stack designs.As the sophistication
in with Satisloh's range of box and controllability of vacuum chamcoaters and proprietary coating bers has improved,it has beenpossiprocessesfor hard coating,AR coat- ble to develop unique designs with
ing and top coating. This ensures specifichardness,refractiveindices,
that the companycan offer the mar- optical and mechanicalperformance
ket a full packageof top performing parameters.The current options include:
coatingprocesses.
For those wising to add a coating
system to their operation, Leybold
offers the Minil"ab and Easylab.
These are complete turnkey solutions priced and engineeredspecifically for all sizesof lab. They can be
configured around either the CCS
design,or for those with a larger capacity requirement,the Boxer family can be incorporated.These setups can include back-sidespin hard
coaters.
Featuresandbenefitsinclude:
/'o Personalised
processesadjusted
to customers'needs
o Optimisedphysicalspace
o Easy-tousesoftware
o Remoteanalysisvia modemand
datarecording
. Hydrophobiccoatingsmay be
appliedinchamber
r Cubic chamberproviding:
. Excellentgeometriccoatingon
lenses
o Quick exposureand removalof
protectivechamberliners
r A click-in mechanismexchanges
the substratesquickly and easily
o Easymaintenance
18 . ln$I luw,oplicol-uorld,to.ul
The I 200-DLFhigh volumebox cooterfrom Solisloh
MultiquartzZ-P
Performance - ML
Ioncote K-HL
Easy-coat
Multicote
The coatings are applicable to low and
high index substrates and offer the
following benefits:
I Superior abrasion resistance,
exceeding market benchmarks
I Excellent durability of layer
package in accelerated ageing
tests
I Cosmetically and optically
superior performance through
index matching of the lacquer
The range of consumables includes
a range oflacquers and primer and various substances for vacuum coating,
plus Satin super hydrophobic top coat.
The range of equipment currently on
offer includes three coating machines
- the 120GDLF box coater and the SP200 sputter coater,plus the MC-380.
The 120GDLF is a high volume box
coater equipped with a state-of-the-art
diffusion pump and is capable of providing consistently high quality AR
coatingsin a very short processtime.
Optionally, two 120GDLF s can work
in a parallel configuration.
The system deposits anti-reflection
and/or mirror coatings on organic
and mineral substrates via a thermal
evaporation process. It offers multiple
process applications according to the
material being coated and is suitable
for Rx lab or stock lens production.
Features of the machine are:
n Hot processfor mineral lenses
E Six sector dome or a flipover
system for double side
processing
I Extendable mask system
E Ion assisteddeposition
I Electron beam gun with a
shutter
I Multi nozzle venting system for
reduced venting times
E Evaporation optimised by digital
sweeper control
tr Powerful pump system with one
diffusion pump (two molecular
pumps on request)
Benefitsare:
cycle time of 15 minutes for four lenses
with double-sidecoating. The flipover
Consistent(uniform)ARcoatings
system is fully automatic and the maHigheststocklensproductivity
chine can accommodate lenses from
Fasttechnologywith low process
50 to 75mm diameter. Substrates of
times
CR39,polycarbonate,high index, phol,owestcostperlens
tochromic and mineral (in up to 1.9)
ProvenSatislohprocesses
can be handled. The machine offers
Easyjobandprocessset-up
ease of use and low maintenance, due
to a single reactive sputtering source.
The 120GDLFcan handle CR39,
It is possible to change between difpolycarbonate,high index, acrylic, fering coating types and materials, e.g,
photochromicand mineralglassup to from AR coating organic materials to
n =1.9.Capacitiesare from 324lenses AR coating mineral lenses,or to mirror
(51mm)to 126(80mm)for the six-sec- coating.The operator simply choosesa
tor domeand252to 96for the flipover different process on the touch screen;
system.
no otherchanges are necessary.
The MC-380is also a box coaterof
similar general design to the 1200DLF, but is produced for lower
throughput rates. It can handle the
samelensmaterialsandthe capacities
are120to 45 (51mmto 80mm)for the
three-sectordomeand42to 32 (48mm
to 66mm) for the flipover system
(without top heaters). Production
rates are fast, with 44 lenses being
coatedin about50minutes.
In the Iab-38GH version, the system is coupledwith an integratedultrasoniccleaningunit andpreparation
and degassingfacilities.Two or more
MC-Lab-380-H
units can be arranged
in a parallelconfiguration,sharingthe
ultrasonicsystem.
Featuresof the combinedsystemare:
I Hot processfor minerallenses
(requiresheateroption)
I 3-sectordomeor flip over
system
I Extendablemask system
I Ion assisteddeposition
I Electronbeamgun with shutter
I Pumpsystemwith powerful
molecularturbo pump (1900l/s)
I Touch screenoperatorterminal
I Fully automatedcleaning,
includingbaskettransportation
I Six tanks,cleaningand rinsing
under a flow box
I 'Slowlift-out'forlensdrying
I Degassing
oven
The third system,the SP-200
sputter
coater,is designedto especiallysuit
smallbatches,continuousflow coating
and rush orders. It has a verv fast
Three configurations are available:
. Single side AR coating (one
hour retail concept) - applies
backside AR and hard coating
. Auto-flip AR system with W
cured hard coat (wholesale
laboratory concept) - applies
double sided AR and backside
hard coating
o Auto-flip AR system with
thermal cured hard coat
(wholesale factory concept) applied double sided AR and
integrated double-sided
hardcoat.
Although this review does not
specifically deal with hard coating machinery, mention should be made of
the Magna-spin. This is a spin coating
system for front-side factory hard
coated lenses. It uses [fV cured lacquers, with three versions being available - suitable for CR39, high index,
tintable and polycarbonate substrates.
Endnotes
(l ) Meissner Trop
When pumping o chomber from olmosphere, the moior residuol gos componeni is woler vopour. A Meissner trop is,
e s s e n t i o l l yo, c o i l o f l u b i n g t h r o u g h w h i c h
o liquid / gos cryogenflows to moinioin
o low surfoce iemperolure.
(2) Mognetron
A mognetron is bosicolly o microwove
generotor in which eleclrons, generoted
by o heoted cothode, move under the
c o m b i n e d f o r c e o f e l e c l r i co n d m o o n e l i c
fields.
OW Mav 2O1O. 19