CA2316233A1

CA2316233A1 - Optical array converting uv

Info

Publication number: CA2316233A1
Application number: CA002316233A
Authority: CA
Inventors: Jan Kuklinski
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-12-30
Filing date: 1997-12-29
Publication date: 1998-07-09
Also published as: ES2178020T3; WO1998029715A1; DE69711680D1; PL317746A1; NZ336599A; WO2003100368A1; AU723219B2; DE69711680T2; EP0941458A1; EP0941458B1; US6392239B1; ATE215690T1; JP2002513466A; US6822789B2; PL181650B1; IL130630A0; AU5419698A; IL130630A; KR20000062387A; US20030218797A1

Abstract

An optical array containing a system of absorptive filters and a system of interference filters. For the sun light the spectral characteristics of transmission of the optical array is close to the world-wide accepted Diffey Standard. That standard models human skin sensitivity to UV burning. The invention allows making inexpensive, miniature UV sensors that can be applied in miniature devices measuring burning power of UV contained in the sun light.

Description

m. v . . ~.; ~ . ~..; ~, -.,~.. ~.....; m ., . . . _1~ ~ _ ,~ ~ ., ., . _ ~ .
. ,. "" ...,_,.". . . . , " , ~~CA~02316233 2000-06-22y Optical a Tray converting UV
This invention is an optical array converting W radiation, especially contained in sunlight.
.: The spectral charactcristiL of the transmission of the filter is similar to the sensitivity of human skin to sun burning. That sensitivity is described by the widely recognized DifFey Standard called also the 1~:rythe:na Action Spectrum.
The Roberston Eerger UV meter is widely used over the past two decades to measure UV in good approximation the DiffeylErythemal Spectral Response. This stationary device is based on a phosphore convertor screen as the principle rrsean to reach a spectral response close to the Erythemal/Diffey Curve.
Hv nov~~ there arc a few W hand-held measuring dCVIGG9 known on the market that are targeting monitoring of UV radiation for avoiding sunburning:
CASIO Computer Ltd. manufactures a device called "CASiO UC-I2U UV", which has an optical array containing absorptive filter made of material similar to Schott UG-11 and a photodiode. The spectral characteristic of the device doesn't match the Diffey Standard.
The device illuminated by sunlight is too sensitive to UV-A, that has low burning power.
US patent ~.196.7U~ describes a device measuring the intensity and dose of UV.
The device has an optical array containing: an absorptive filter made of material similar to Schott UG-1 1, a photo-luminescentive material and a photodiode. The spectral characteristic of the device doesn't match the Diffcv Standard. The device is too sensitive to UV-A
comparing to its sCnsitivity to UV-B.
Several others solutions for biologically oriented monitors of UV radiation were also discussed, ansong them:
US patent 5,036,311 describes a UV-monitoring system in which a light sensing element ~$ placed under a curved optical element with interference Crlters imposed on its surface.
3U US patent 5,401,970 describes a L1V-monitoring device which incorporates a UV-B
sensor and a VIS sensor. The UV-B detector involved is described to be based on a phosphor convertor screen.
pMENDa=D SHEET ' KL \ . 11.x:\ ~ 1:1':\-.W 1::\L Itt::\ tl~1~ ' v . -... , '" '' ~''CA 023~16233~ 2000-06-22 3i ~U
Description of the invention t The invention solves the problem of constructing a device equipped with an optical array converting U1'. visible and IR radiation that has the spectral characteristic of the transmission similar to the Diffev Standard.
Definition of the relative internal transmtsston of a set of niters:
-(~rel~tC~~~Tint(~")IT;ntC31 O) t,1 ) where:
wavelength in nano-me#ers .i5 Tr°'""(~.) relative internal transmission for ~ wavelens_cth T",~(~ ) intcmal transmission for J~ wavelength T,~.(310) internal transmission for 310nm wavelengtrr Note that the total internal transmission of the set of absorptive filters is equal to the product 50 of internal transmissions of each consecutive filter Definition of the relative transmission of a set of filters:
-rrelt~~-~~~7~ ~T 31 ~~
WIIC!'e:
55 7~ wavelength in nano-meCCrs 'f"'(~,) relative transmission for ~. wavelength T{~) tra.nsmission for h wavelength ' T(310) transmission for 3lUtun wavelength GO The Diffey spectral characteristics Hill be denoted as D(h) where:
wavelength in nano-mCters .
6s In the first solution the array contains a system of absorptive filters to block visible and IR.
radiation, a system of interference fitters modifying transmission of UV
and/or blocking visible and IR. radiation, scattering elements, elements fotriing the light beam. Interference filter/filters islarc made of layers of materials having high and low W
refractive indexes.
According to the invention one; of the system of interference filters has layers made of 2 ' AhIEhDED SHEET

70 ~ Hafnium oxide and/or Zirconium a~cide. A collimator placed in the optical path forms the light beam. The collimator can have suzfacex highly absorbing light. At the beginning of the optical path a scatterer is place to achieve non-directional characteristic of the array. The scatterer can be made of PTFE
75 In the second solution the arrat~ contains the first system of absorptive filters to partly block W-A, the second system of absorptive filters to block visible and IR.
radiation and may contain scattenng elements andior system/s~~sterns of interference filter/filters.
The first system of absorptive filters has internal relative transmission T"';~,(~): between 0 and 0.2 for 1=290nnt. betwr:c:n O.s4 and 0.7 for ~.=300nm, between. 0.5 and 0.$ for sU ~,=324nm. between 0.04 and 0.3(~ for i~=330nm, between l0E-3 and 0.1 for ~,=340ttm.
between 7* l0E-6 and 0.02 for i~=350nm, between 7' l0E-7 and 7f l0E-3 for ~,=3bOttrn, betwrxn 2" l 0E-7 and 7' I OE-3 for ~.=3 70nm, bctw~cen 2* 10~-5 and U.03 for ~.= 380nm, between 2" l OE-3 and 0.14 for ~=390nm. The total optical thickness of the first system of absorptive filters is between 0. ~ and 2mm.
85 The second system of absorptive filters has internal relative transmission T'~',M(~): between 0 and 0.3 for ~,=290nm, between 0.7 and 0.8 for ~=30,'Jnm, between l and I .3 for 7~=320nnt, between 1 and I 4 for ;t=33Gnm, between l and 1.3 for 1=340nm, between l and 1.12 for ~.=>>Orm, between U.6 and 0.8 for ~.=360nm, between 0.14 and 0.3 for J~=374nm, between l0E-3 and 0.015 for ~=380nrn, between IOE-10 and l0E-6 for ~.~390nm. The total optical '~ 9(~ thickness of the first system of absorptive filters is between 0.5 and lOmm.
At the beginning of the optical path a scat~terer is placid to aclveve non-directional characteristic of the arraw. The seatterer can be made of PTFE. In the optical path additional systcm/sv~stems of interference fitters can be placed to block visible and ~IR.
radiation and/or to modifi~ transmission in UV range.
This invcmtion al)ows producing a cheap and simple optical array with a spectral characterzsties in the IJV-A and W-B range follomng the human skin sensitivity described by Diffev Standard. 'The~scatterer ensures non-directional characteristics of the array.
Other standards of skin sensitiaitt to UV-A and UV-B burning can also be easily followed.
1uu The invention is presented on the block diagrams where Fig 7 prexnts the construction of the version 1 of the ~pti,:.al array, Fig2 presents the construction of another variant of the invention presented on Figl, Fig3 presents the construction of the version 2 of the optical array, Fig4 presents the constnirtion of the of the version 3 of the optical array. Fig. 5 toy presents T"'{~.)'D(310)/T't~(310) for optical aarrav from Fig 2 in comparison with the -.,h~~~;D~D SNEE'~

m.v , rw.v ~ m;~ r,-..n. m.wm..v ~rw ~cn- ..~-.~;1 ~ a ~ y ~ ~'1~W __ ~.~w:~cW
~~l.- T~1:) J:J _.~:J;l~t'IWiJ. R :1 Diffey Standard D(h), Fig. 6 presents T"'(~.)'D(3I0)VI"''(310) for optical array from Fig 3 in comparison with the Diffev Standard D(l), Fig. 7 presents T"'(?~,)*D(310)/'T"~(310) for optical array from Fig 4 in comparison with the Di.ffef Standard D(~l).
11U ~. Description of the version 1.
The array contains: the layer 1 shat scatters light, a collimator _2, an absorptive filter 3 that makzs _a system of absorptive filters, a set of interference fitters 4 that makes a system of interference filters. The absorptive filter 3 is made of material trat~parent to'JV and blocking visible and IR. radiation. That property has M 1 material, with a characteristics 115 presented in the table belcw.
In that exarnpie a scatterer 1 is made of PTFE, and the absorptive filter 3 is a piano-parallel plate, 8mm thick. made of M1 material Schott UG-1 1 like The set of interference filters 4 that is placed on the absorptive filter's 3 surfa;.e eor<sists of 38 layers of"Hafnium oxide and/or Zirconium oxide and Silica oxide.
I 2O The scatterer 1 ensures non-directional characteristics of the array. The collimator 2_ forms the light beam. To achieve desired spectral characteristics the fight beam passes througl~t the absorptive filter 3 and the interference filter 4.
In the other variant oftlte version 1, that is showrn on the Fig 2, the array contains: the layer 125 5 that scatters light. a collimator 6, absorptive filter' that makes a system ofabsorptive filters and a first set of interference filters t3 and a second set of interference filters 9 that both make a system of interference filters. The absorptive filter 7 is made of material transparent to IJV and blocking visible and IR. radiation. That property has M
1 material, urith a characteristics presented in the table below. , 13(1 In that example a scatterer ~ is made of PTFE, and absorptive filter 7 is a piano-parallel plate, Rmm thick, made of MI material, Schott UG-11 like. The first set of interference filters 8 and the second set of interference filters 9 are placed on the absorptive filter's 7 surfaces and together consists of G2 layers of Ha&tium oxide and/or Zirconium oxide and Silica oxide.
13 > The scatterer ~ ensures non-directional characteristics of the array. The collimator 6_ forms the light beam. To achieve desirrd sp~;ctrul characteristics the light beam passes through the first interference filter 8. the absorptive filter 7 and the second interference filter 9.
Ort the Fig 5 cltart the T'''(1)*D(310)rh"'(3 I O) characteristics of the array is plottod as a broken line, the Diffev Standard is plotted as a solid line. 4n the chart these t,~~o curves 1.t0 are close to each other in the 310-325nm range.

4 _ ,- s r ,~4~F~~~~cl s~;~~~

",...,~~ :,-." ,..".~~~..~ "., -~~- 'w~CA ~0231~6233 2000-06-22 --_ ";~...._,-T.,;. «:~ _.;:,.~~,-~".~."", De.~scriptipo of the version 2.
The array contains the la.,,er 10 that scatters light, a first absorptive filter 1 l that makes a ' first system of absorptive filters, a second absorptive filter 12 that makes a second system 1:~5 of absorptive filters. The first absorptive filter 11, is made of material transparent to L'V
' with dzcreasing e: ausnussion when the wavelength is changed from 320 to 35Gnm, the second absorptive filter 12 is made of material transparent to IJV and blocking visible and IR. radiation. That property have materials M2 and Ml respectively, v~~ith characteristics prcsc:rac:d in the table belotv_ 1 Sc; 1n that example a scattcrcr 10 is made of PTFE, the Frst absorptive f tier ~ 1 is a plano-parallel plate, l.~mm thick, made of M2 material, Schott G~i-19 like, the second absorptive filter 12 is a piano-parallel plate. 8 mm thick, made of M1 material, Schott LrG-1 i like.
The scatterer l0 ensures non-dmcctional characteristics ofihe array. To achieve desired I vs spectral characteristics the light b:am passes through the first absorptive filter 1 I and the second absorl.~tive filter 12.
On the Fig 6 chart T"~(~.)"D(: 10)rF"°x(310) characteristics of the array is plotted as a broken line, the Diffe~~ Standard is plotted as a solid line.
tb0 Description of the version 3.
The array contains: a first absorptive I:lier 7 3 that makes a first system of absorptive Ftters, a second absorptive filter .1~, chat makes a second system of absorptive fhters and a first set of interference filters 15 and a second set of interference fi tiers 15 that both make a system 16s of interference filters. The fi rst absorptive filter 13 is made of material tra.sparent to UV
with decreasing transmission when wavelength is changed from 320 to 3SOnm., the second absorptive filter 14 is made of material transparent' to UV and blockine visible and IR.
radiation. That property have materials M2 and MI respectively, vvth characteristics presented in the table below. Interference filters are constructed to block visible and IR.
t 7« radiation and/or to modify transmission characteristics in W. .
In that example the first absorptive filter 13 is a piano-parallel plate, l.Smm thick, made of M2 material, Schott GG-19 like. The seCOnd absorptive filter ~ v~~ith interference filters 1 ~, 16 placed on the filter 14 surfaces are made together by Schott as Schott filter.
t 75 To achieve desmed spectral characteristics the light beam passes through the first absorptive filter 13. the first interference filter 1 ~, the second absorptive filter 14 and the second interference f tier 16.
-pt~Er~GEG SHEET

._. .. _ . _.. CA 02316233 2000-06-22 -_ ....._._. ... "~ ..."." "., ""
t80 i On the Fig 7 chart T"'(7~)"D(310)fT"''(310) characteristics of the array is plotted as a broken tine, the Dif~ey Standard is plotted as a solid line.
TABi.E of relative internal transmission T'~',~t(7;,) ' ~ nm 290. 300 310 320 330 340 350 Ml glass, ttunimal_value0 0.7 1 1.0 1.0 i.0 1.0 8 mm tlucic~ maximal 0.3 0.8 1 1.3 1.4 1.3 1.12 value M2 glass, f mirutnal 0 0.34 1 0.5 0.04 l0E-3 7~10E-6 value 1.5 mm duckmaximal 0.2 0.7 1 0.8 0.3G 0.1 0.02 value i, nm _ 360 370 380 390 Mi glass. minimal value0.6 0.14 l0E-3 l0E-lU

8 mm thickmaximal value0.8 0.3 I 0.015 10E-6 Lvi2 glass.~ minimal ~ 2*10E-72'10-7 2'l0E-5 2*l0E-3 value 1.5 tntn mawimal vafue~*10-3 7l0E-3 U.U3 0.14 thick Data in tables above are T"';"~(~l) characteristics of piano-paraiel places made of M!, M2 with given thickness.
'Ihe exact values of T"'""(a-) are described in the example constructions.
These data are example values and ii is obvious tlhat the invention is not restricted to them.
190 The optical array in the example constructions has the spectral characteristics similar to human skin sensitivity to UV contained in sunlight. Fig 5 presents T"'(7~)*D(310)ff"'(310) chart for optical array from Fig 2 in comparison with the Diffey Standard D(~.), Fig. 6 presents T"'(~.)'D(310)/T'r'(3 10) chart for optical array from Fig 3 in comparison with the Diffey Standard D(~.), Fig. 7 presents T"'(~,)*D(310)!Tn'(310) chart for optical array from 195 Fig 4 in comparison with the Dififev Standard D(~.). The biggest discrepancies between the characteristics and the DifFev Standard are for UV-C that is absent in sunlight arid UV-A
that has a minimal burning power comparing ~~ith total burning power of sun UV.~
At:~Er~~~~ SHEET

Claims

Claims What is claimed is:

1. The optical array converting UV, visible and IR. radiation, especially contained in sunlight, with a spectral characteristics, following the Diffey Standard comprising a system of absorptive filters (3) (Fig. 1), (7) (Fig. 2) to modify transmission characteristics in the UV range and/or to block visible and IR radiation characterized by internal transmission for a given wavelength divided by its internal transmission for 310nm light within the following range: between 0 and 0.3 for .lambda.=290nm, between 0.7 and 0.8 for .lambda.=300nm, between 1 and 1.3 for .lambda.=320nm, between 1 and 1.4 for .lambda.=330nm, between 1 and 1.3 for .lambda.=340nm, between 1 and 1.12 for .lambda.=350nm, between 0.6 and 0.8 for .lambda.=360nm, between 0.14 and 0.3 for .lambda.=370nm, between 10E-3 and 0.0015 for .lambda.=380nm. between 10E-10 and 10E-6 for .lambda.=390m, a system of interference filters (4) (Fig. 1), (8), (9) (Fig. 2) to modify transmission characteristics in the UV range and/or to block visible and IR radiation, a scatterer (1) (Fig. 1), (5) (Fig. 2) at the beginning of the optical path to achieve non-directional spectral transmission characteristics of the array and to improve the spectral transmission, characteristics of the array.

2. The array in claim 1 comprising a collimator (2) (Fig. 1), (6) (Fig. 2) placed in the optical path to form the light beam passing through the array and to improve the spectral transmission characteristics of the array where the collimator surface should be highly absorptive to the light.

3. The optical array converting UV, visible and IR. radiation, especially contained in sunlight, with a spectral characteristics following the Diffey Standard comprising a first system of absorptive filters (11) (Fig. 3), (13) (Fig. 4) to modify transmission characteristics in the UV range and/or to block visible and/or IR radiation characterized by internal transmission for a given wavelenght divided by its internal transmission for 310nm light within the following range: between 0 and 0.2 for .lambda.=290nm, between 0.34 and 0.7 for .lambda.=300nm, between 0.5 and 0.8 for .lambda.=320nm, between 0.04 and (0.36 for .lambda.=330nm, between 10E-3 and 0.1 for .lambda.=340nm, between 7*10E-6 and 0.02 for .lambda.=350nm, between 2*10E-7 and 7*10E-3 for .lambda.=360nm, between 2*10E-7 and 7*10E-3 for .lambda.=370nm, between 2*10E-5 and 0.03 for .lambda.=380nm, between 2*10E-3 and 0.14 for .lambda.=390nm, a second system of absorptive filters (12) (Fig. 3), (14) (Fig. 4) to modify transmission characteristics in the UV range and/or to block visible and/or IR radiation characterized by internal transmission for a given wavelength divided by its internal transmission for 310nm light within the following range: between 0 and 0.3 for .lambda.=290nm, between 0.7 and 0.8 for .lambda.=300nm, between 1 and 1.3 for .lambda.=320nm, between 1 and 1.4 for .lambda.=330nm, between 1 and 1.3 for .lambda.=340nm, between 1 and 1.12 for .lambda.=350nm, between 0.6 and 0.8 for .lambda.=360nm, between 0.14 and 0.3 for .lambda.=370nm, between 10E-3 and 0.0015 for .lambda.=380nm, between 10E-10 and 10E-6 for =390nm.

4. The array in claim 3 comprising a scatterer (10) (Fig. 3) at the beginning of the optical path to achieve non-directional spectral transmission characteristics of the array and to improve the spectral transmission characteristics of the array.

5. The array in claim 3 comprising additional interference filters (15), (16) (Fig 4) to improve the spectral transmission characteristics of the array.