OPTICAL ARRAY CONVERTING UV

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: Optical array converting UV This invention is an optical arra converting UV radiation, especial h contained in sunlight The spectral characteristic of the transmission of the filter is similar to the sensitivity of human skin to sun burning That sensitivity is described by the vvideh recognized Diffey Standard By now there are a few UV measuring devices based on an optical absorptive filter CASIO Computer Ltd manufactures a device called "CASIO UC-120 UV". which has an optical array containing absorptive filter made of material similar to Schott UG-1 1 and a photodiode The spectral characteristic of the device doesn ' t match the Dιffe Standard The device illuminated sunlight is too sensitive to UV-A. that has low burning power US patent 5 196 705 describes a dc\ ιcc measuring the ιntensιt\ and dose of UV The device has an optical containing an absorptne filter made of matcπal similar to Schott UG- 1 1. a photo-lumιnesccntι\ e material and a photodiode The spectral characteristic of the de\ ice doesn't match the Diffey Standard The de\ ice is too scnsitn e to UV-A comparing to its sensitivr to UV-B Description of the invention The invention solves the problem of constructing a device equipped w ith an optical arra> converting UV. visible and IR radiation that has the spectral characteristic of the transmission similar to the Dιffe\ Standard Definition of the relative internal transmission of a set of filters - Cl T ,cl πι t(λ ; T ιnl (λ)/T lllt (310) (1) where λ w avelength in nano-metcrs T re ', nt (λ) relative internal transmission for λ wavelength T mt (λ) internal transmission for λ wavelength T ιn ,(310) internal transmission for 31 Onm w avelength Note that the total internal transmission of the set of absorptive filtei s is equal to the product of internal transmissions of each consecutive filter Definition of the relative transmission of a set of filters T rel (λ)=T(λ)/T(310) (2) where λ wavelength in nano-meters T rcl (λ) relative transmission for λ wavelength T(λ) transmission for λ wavelength T(310) transmission for 31 Onm w avelength The Dιffe\ spectral characteristics w ill be denoted as D(λ) (3) where λ wa\ elcngth m nano-metei s In the first solution the contains a s\ stcm of absorptive filters to block visible and IR radiation, a system of interference filters modify ing transmission of UV and/or blocking visible and IR radiation, scattering elements, elements forming the light beam Interference filter/filtcis is/are made of of materials haung high and low UV refractive indexes According to the l ention one of the s\ stcm of lntciference filteis has crs made of Hafnium oxide and/or Ziiconium oxide A col mator placed in the optical path forms the light beam The colhmator can ha c surfaces highh absorbing light At the beginning of the optical path a scatterer is placed to achieve non-directional characteristic of the arra\ The scatterer can be made of PTFE In the second solution the arra\ contains the first s\ stcm of absorptn c filters to parth block UV-A. the second s\ stem of absorptn c filtei s to block visible and IR radiation and ma\ contain scattering elements and/oi s\ stems of interference filter/filters The first s\ stem of absorptive filters has internal relative transmission T rcl ιn ,(λ) between 0 and 0 2 for λ=290nm. between 0 34 and 0 7 for λ=300nm. between 0 5 and 0 8 for λ=320nm. between 0 04 and 0 36 for λ=330nm. between 10E-3 and 0 1 for λ=340nm. between 7* 10E-6 and 0 02 for λ=350nm. between 2* 10E-7 and 7* 10E-3 for λ=360nm. between 2* 10E-7 and 7* 10E-3 foi λ=370nm. between 2* 10E-5 and 0 03 for λ=380nm. between 2* 10E-3 and 0 14 for λ=390nm The total optical thickness of the first system of absorptive filters is between 0 5 and 2mm The second stem of absorptive filters has internal relative transmission T re ' inl (λ) between 0 and 0 3 for λ=290nm. between 0 7 and 0 8 for λ=300nm, between 1 and 1 3 for λ=320nm, between 1 and 1 4 for λ=330nm, between 1 and 1 3 for λ=340nm. between 1 and 1 12 for λ=350nm. between 0 6 and 0 8 for λ=36()nm. between 0 14 and 0 3 for λ=370nm. between 10E-3 and 0 015 for λ=380nm. between lOE-10 and 10E-6 for λ=390nm The total optical thickness of the first system of absorptn e filters is between 0 5 and 10mm At the beginning of the optical path a scatterer is placed to achieve non-directional characteristic of the a rra\ The scatterer can be made of PTFE In the optical path additional s\ stems of interference filters can be placed to block visible and IR radiation and/or to modιf\ transmission in UV range This invention allows producing a cheap and simple optical w ith a spcctial characteristics in the UV-A and UV-B langc following the human skin sensitivity described Standard The scatterer ensures non-directional characteristics of the arra\ Other standards of skin sensιtιvιt\ to UV-A and UV-B burning can also be easily followed The invention is presented on the block diagrams where Figl presents the construction of the version 1 of the optical arrav Fιg2 piescnts the construction of another variant of the invention presented on Fi l . Fιg3 piescnts the construction of the version 2 of the optical . Fιg4 presents the construction of the of the version 3 of the optical Fig 5 presents T rd (λ)*D(310)/T rJ (310) foi optical from Fig 2 m compai ison with the Standard D(λ). Fig 6 presents T rιl (λ)*D(310)/T rel (3 10) for optical from Fig 3 in comparison with the Dιffc\ Standard D(λ). Fig 7 presents T rd (λ)*D( 1 ())/T rel (310) for optical arraλ from Fig 4 m compai ison ith the Standard D(λ) Description of the version 1 The that scatteis light, a colhmator 2. an absorptive filter 3 that makes a stem of absorptive filteis. a set of interference filters 4 that makes a system of interference filteis The absorptn c filtci 3 is made of material transparent to UV and blocking usible and IR iadiation That propcrh has M 1 material w ith a characteristics presented in the table below In that example a scatterer is made of PTFE. and the absorptive filter 3. is a piano-parallel plate. 8mm thick, made of M 1 material Schott UG- 1 1 like The set of interference filters 4 10^ that is placed on the absorptive filter ' s 3 surface consists of 38 la\ crs of Hafnium oxide and/or Zirconium oxide and Silica oxide The scatterer I ensures non-directional characteristics of the ana} The colhmator 2 forms the light beam To achieve desired spectral characteristics the light beam passes through the absorptive filter 3 and the interference filter 4 1 10 In the other variant of the version 1. that is shown on the Fig 2. the array contains the layer 5 that scatters light, a colhmator 6. absorptive filter 7 that makes a stem of absorptive filters and a first set of interference filteis and a second set of interference filters 9 that both make a s\ stem of interference filteis The absorptive filter 2 is made of material 1 15 transparent to UV and blocking visible and IR radiation That property has Ml material, with a characteristics presented in the table below In that example a scatterer 5 is made of PTFE. and absorptive filter 7 is a piano-parallel plate. 8mm thick, made of M 1 material Schott UG- 1 1 like The fust set of interference filters and the second set of interference filters 9 arc placed on the absorptive filter ' s 1_ 120 surfaces and together consists of 62 la\ crs of Hafnium oxide and/oi Zirconium oxide and Silica oxide The scatterer ensures non-directional characteristics of the The colhmator 6 forms the light beam To achιe\ c desired spectial characteristics the light beam passes through the first interference filtci _. the absorptn c filtci 1_ and the second interference filter 9 \1 On the Fig 5 chart the T l (λ)*D(3 10)/T rϋ ( 10) charactci istics of the an a\ is plotted as a broken line, the Standaid is plotted as a solid line On the chart these two curves are close to each othei m the 310-325nm range Description of the version 2 HO The arra\ contains the la\ eι 0 that scattcis light, a first absorptn c filter JJ_ that makes a first S Stcin of absorptn c filters, a second absoiptn c filter YL that makes a second sy stem of absorptn c filteis The fust absoiptn c filtci _M_ is made of matei ial transparent to UV with decreasing transmission when the wax clcngth is changed from 320 to 350nm. the second absorptive filter J_2 is made of material transparent to UV and blocking visible and H IR radiation That propcrtv materials M2 and Ml respectn eh . with characteristics presented in the table below In that example a scatterer _H) is made of PTFE. the first absorptive filter JJ_ is a piano- parallel plate. 1.5mm thick, made of M2 material. Schott GG-19 like, the second absorptive filter 12 is a piano-parallel plate. 8 mm thick, made of M 1 material. Schott UG- 140 1 1 like. The scatterer 0 ensures non-directional characteristics of the array. To achieve desired spectral characteristics the light beam passes through the first absorptive filter J . and the second absorptive filter \2. On the Fig 6 chart T rel (λ)*D(310) T rd (310) characteristics of the array is plotted as a broken 145 line, the Diffey Standard is plotted as a solid line. Description of the version 3 The array contains, a first absorptive filter 13 that makes a first system of absorptive filters. 1 0 a second absorptive filter J_4 that makes a second system of absorptive filters and a first set of interference filters J_5 and a second set of interference filters J_6 that both make a system of interference filters. The first absorptn c filter J_3 is made of material transparent to UV with decreasing transmission when clength is changed from 320 to 350nm. the second absorptive filter J_4 is made of material transparent to UV and blocking visible and IR. 155 radiation That property have materials M2 and M 1 respectively, with characteristics presented in the table below . Interference filters arc constructed to block visible and IR. radiation and/or to modify transmission characteristics in UV In that example the first absorptive filter J_3 is a piano-parallel plate. 1 5mm thick, made of M2 material. Schott GG- 19 like The second absorptive filter J_4 w ith interference filters 160 J_5. 16 placed on the filter 14 surfaces arc made together by Schott as Schott DUG-1 1 filter To achieve desired spectral characteristics the light beam passes through the first absorptive filter J_3. the first interference filter J_5. the second absorpt c filter J_4 and the second interference filter J_6. 165 On the Fig 7 chart T ro '(λ)*D(3 10)/T (3 10) characteristics of the array is plotted as a broken line, the Diffey Standard is plotted as a solid line TABLE of relatπe internal transmission T re ιn ,(λ) Data in tables above arc T lt11 (λ) characteristics of plano-paralcl plates made of M l . M2 with given thickness The exact \ allies of T rd , m (λ) are described m the example constructions These data are example \ allies and it is obvious that the invention is not restricted to them The optical in the example constructions has the spectral characteristics similar to human skin scnsitivitv to UV contained sunlight Fig 5 presents T' d (λ)*D(1 10)/T rd (310) chart for optical arra\ fiom Fig 2 in compai ison w ith the DilTcx Standard D(λ) Fig 6 presents T rt (λ)*D(H0)/T rt (3 l 0) chart toi optical arra\ from Fig 3 m comparison w ith the Dιffe> Standard D(λ). Fig 7 presents T rd (λ)*D(310)A" "ei (31 ) chart for optical arra> from Fig 4 in comparison with the Dιffe\ Standard D(λ) The biggest discrepancies between the characteristics and the Standaid aic for UV-C that is absent in sunlight and UV-A that has a minimal burning power companng w ith total burning power of sun UV

Claims: Claims What is claimed is 1 The optical arra\ converting UV. visible and IR radiation, especially contained in sunlight with a spectral characteristics following the Diffey Standard comprising a svstem of absorptive filters to block visible and IR radiation, a system of interference filters to modifλ transmission characteristics in the UV range and/or to block visible and IR radiation, scattering elements and elements to form light beam The interference filter is made of layers of high and low refractive indexes for UV light and some interference layers in the systems of interference filters (4), (8). (9) are made of Hafnium oxide and/or Zirconium oxide 2 The arra\ in claim 1 with the s\ stem of absorptive filters (3) (7) which internal tiansmission tor a given wavelength dn ided b\ the internal transmission of that second S stem toi 310nm light are between 0 and 0 3 for λ=290nm between 0 7 and 0 8 for λ=300nm between 1 and 1 3 for λ=320nm between 1 and 1 4 for λ=330nm between 1 and 1 3 for λ=340nm between 1 and 1 12 for λ=350nm between 0 6 and 0 8 for λ=360nm between 0 14 and 0 3 for λ=370nm between 10E-3 and 0 0015 for λ=380nm between lOE-10 and 10E-6 for λ=390nm 3 The arra\ in claim 1 comprising a scatterer ( 1) (5) at the beginning of the optical path to achιc\ c non-directional chaiacteπstics of the 4 The an ax in claim 3 comprising the scattcier made of PTFE 5 The arrax in claim 1 comprising a colhmator (2) (6) placed in the optical path to form the light beam passing through the arrax The colhmator surface could be highh absorptn e to the light 6 The optical arra converting UV usiblc and IR radiation cspceialh contained in sunlight with a spectral characteπstics follow ing the Diffex Standard comprising a first s stcm of absorptn c filteis to parth block UV-A light a second s\ stcm of absorptive filters to block visible and IR radiation and optionalh scattering elements and/or sv stem/s\ stems of interference filteis The internal transmission of the first sλ stem of absorptn e filters divided b\ the internal transmission of that first s\ stem for 31 Onm light arc between 0 and 0 2 for λ=290nm between 0 34 and 0 7 for λ=300nm, between 0 5 and 0 8 for λ=320nm between 0 04 and 0 36 for λ=330nm between 10E-3 and 0 1 foi λ=34ϋnm between 7* 10E-6 and 0 02 foi λ=350nm between 2* 10E-7 and 7* 10E-3 for λ=360nm. between 2* 10E-7 and 7* 10E-3 for λ=370nm. between 2* 10E-5 and 0 03 0 for λ=380nm. between 2* 10E-3 and 0 14 for λ=390nm 7 The arra\ m claim 6 with total optical thickness of the first s stem of absorptive filters (1 1). (13) between 0 5 and 2mm 8 The in claim 6 with the second system of absorptive filters (12). (14) which internal transmission for a given wa\elength divided by the internal transmission of that 5 second for 310nm light arc between 0 and 0 3 for λ=290nm. between 0 7 and 0 8 for λ=300nm. between 1 and 1 3 for λ=320nm. between 1 and 1 4 for λ=330nm, between 1 and 1 3 for λ=340nm. between 1 and 1 12 for λ=350nm. between 0 6 and 0 8 for λ=360nm, between 0 14 and 0 3 for λ=370nm. between 10E-3 and 0 015 for λ=380nm. between lOE-10 and 10E-6 for λ=390nm 0 9 The arra\ in claim 6 with total optical thickness of the second sx stem of absorptive filters ( 12). ( 14) between 0 5 and 10mm 10 The arra\ in claim 6 comprising a scatterer at the beginning of the optical path to e non-directional charactciistics of the arra\ 1 1 The arra\ m claim 10 comprising the scatterer made of PTFE ^ 12 The arra\ in claim 6 comprising additional interference filter/filters ( 15). ( 16) to block visible and IR radiation and/or to modify a transmission characteristics in the UV range 13 The arra\ in claim 12 compi ismg la\ cιs made of Hafnium oxide and/or Zirconium oxide as elements of the set of lntciference filteis ( 15). ( 16)

Inventors: KUKLINSKI JAN, KUKLINSKI, JAN
Applicants: KUKLINSKI JAN, KUKLINSKI, JAN
Application year: 1997
Main classification: G01J1
IPC codes: A61B5, G01J1, G02B5