BIOMETRIC AUTHENTICATION SYSTEM

Abstract

A biometric authentication system including: a translucent protective plate having an authentication region on a front face of the protective plate, and a reverse side forming the second face of the plate, essentially in parallel to the front face; a light emitting source to illuminate an object pressed against or being in touch with the authentication region; a sensor arranged at the reverse side or in a distance from the reverse side; an optical path from the authentication region to the sensor; an optical filter within the optical path;
whereat the optical filter is a layered near infrared (NIR) filter including: at least one of an inner ZnO.sub.x and/or inner TiO.sub.x layer at a substrate side; followed by a multitude of silver layers, each silver layer being separated from each neighboring silver layer by at least one of a further ZnO.sub.x and/or a further TiO.sub.x layer; at least one of an outer ZnO.sub.x layer, an outer TiO.sub.x layer, and/or a blocking layer deposited on the outermost silver layer.

Claims

1. A biometric authentication system comprising: a translucent protective plate having an authentication region on a front face of the protective plate, and a reverse side forming the second face of the plate, essentially in parallel to the front face; a light emitting source to illuminate an object pressed against or being in touch with the authentication region; a sensor arranged at the reverse side or in a distance from the reverse side; an optical path from the authentication region to the sensor; an optical filter within the optical path; whereat the optical filter is a layered near infrared (NIR) filter comprising at least one of an inner ZnO.sub.x and/or inner TiO.sub.x layer at a substrate side; followed by a multitude of silver layers, each silver layer being separated from each neighbouring silver layer by at least one further metal oxide layer consisting of a further ZnO.sub.x and/or a further TiO.sub.x layer; at least one of an outer ZnO.sub.x layer, an outer TiO.sub.x layer, and/or a blocking layer deposited on the outermost silver layer.

2. The system according to claim 1, wherein the blocking layer consists of at least one of TiO.sub.x, ZnO.sub.x, SnO.sub.x, CryO.sub.x and/or NiCrO.sub.x.

3. The system according to claim 1, wherein a metal interface layer consisting of a metal corresponding to the respective metal of a metal oxide layer is provided between at least one neighboring silver layer and the metal oxide layer.

4. The system according to claim 1, wherein the metal-oxide layers are substoichiometric at least at the silver side or sides.

5. The system according to claim 1, wherein at least one ZnO.sub.x layer is an aluminum doped ZnO.sub.x:Al (AZO) layer, or a Galium doped ZnO.sub.x:Ga (GaZO) layer.

6. The system according to claim 1, wherein an antireflective (AR) stack of alternating high and low refractive layers is deposited on one of the outer ZnO.sub.x layer, the outer TiO.sub.x layer, or the blocking layer.

7. The system according to claim 6, wherein the NIR-stack comprises at least 4 layers, for instance 16 to 32 layers.

8. The system according to claim 1, wherein a metallic or a semi-conductive seed layer is provided at the substrate surface.

9. The system according to claim 1, wherein a further AR-stack of alternating high and low refractive layers is deposited between the substrate or the seed layer and the inner ZnO.sub.x or inner TiO.sub.x layer.

10. The system according to claim 9, wherein the further AR-stack comprises at least 2 alternating layers.

11. The system according to claim 10, wherein the further AR-stack is also a UV-light damping or blocking stack.

12. The system according to claim 1, wherein a SiO.sub.2 layer, or a stack of alternating SiO.sub.2 and at least one high index layer consisting of high index material is sandwiched between two further metal oxide layers (3), whereat each of the two further metal oxide layers is in direct contact to the or to a SiO.sub.2 layer, and is adjacent to a respective silver layer with its side facing away from the sandwiched SiO.sub.2 layer(s).

13. The system according to claim 12, wherein the high index material is Ta.sub.2O.sub.5, TiO.sub.2, Nb.sub.2O.sub.5, HfO.sub.2, ZrO.sub.2 or Si.sub.3N.sub.4.

14. The system according to claim 12, wherein the sandwiched stack is a three layer stack consisting of two SiO.sub.2 layers and a high index layer sandwiched between.

15. The system according to claim 1, wherein the light emitting source is a planar light source arranged below the authentication region.

16. The system according to claim 1, wherein the light emitting source is a separate light source arranged below the authentication region.

17. The system according to claim 1, wherein the filter has a wavelength shift of smaller 5% of the NIR edge when using light in an angle of 600 to the surface normal instead of a 0°-degree measurement.

18. The system according to claim 1, wherein the optical path comprises a lens or a mirror.

19. The system according to claim 1, wherein the optical path comprises a collimator.

20. The system according to claim 1, wherein the optical path does not comprise one of a lens, a mirror or a collimator.

21. A touch screen comprising a system according to claim 1.

22. An electronic device comprising a touch screen according to claim 21.

23. The electronic device according to claim 22 being a cell phone, a touch pad, a computer, or another input/output device.

Description

FIGURES

[0029] The invention shall now be further exemplified with the help of figures. It should be mentioned that the figures are merely drawn to demonstrate the function of one or usually several embodiments of the invention without showing scaled dimensions or proper proportions of certain components to make the principals of the invention easier to see. The figures show:

[0030] FIG. 1: fingerprint identification system, FID I;

[0031] FIG. 2: fingerprint identification system, FID II;

[0032] FIG. 3: detail of system II;

[0033] FIG. 4 to 7: principles of filters for an inventive FID system;

[0034] FIG. 8 to 10: state of the art filters for FID systems;

[0035] FIG. 11 to 15: optical properties of filters used with inventive FID systems.

[0036] FIG. 1 shows variations of a first embodiment of a fingerprint identification system 20, comprising a split cover plate 21 having a front plate 22 with a fingerprint area 37 to be touched by the users finger 36 and a backplate 23 to fix the LED array 24 on the back of the front plate 22 and to have further components like e.g. a further light source 29, an NIR filter 31 or a transparent spacer 25 having a low refractive index (RI) attached on the reverse side of the backplate 23, which here also forms the reverse side of the cover plate 21. A finger 36 in touch with the fingerprint area 37 of the cover plate 21 is illuminated by at least some LEDs of the LED-array 24, the separate light source 29, or both together. An optical path of the light reflected by the fingerprint is defined by its boundaries 35, the reflected light being symbolized by an arrow departing from the fingerprint area 37. Having past the cover plate 21 and the spacer 25 the light in the optical path is focused by an optional lens 26, which can be a micro-lens, to the sensor 28, which can as an example be a photo-chip. The sensor 28 is connected with a controller unit 28, which can be the CPU of an electronic device comprising the optical fingerprint identification system, e.g. within a touch screen, or can have a separate controller connected to the circuitry of the device (not shown). Within the optical path the reflected light as well as potential interfering light from the exterior or the LED-array can be filtered by a filter stack 30 which can be deposited on various surfaces which may also form optical interfaces within the boundaries 35 of the optical path between the fingerprint area 37 and the sensor 28. In an alternative embodiment, additionally shown in FIG. 1 a separate filter 31 can be used comprising such an NIR-filter stack on a separate glass.

[0037] It should be noted that with FIG. 2, FIG. 3 and especially with FIG. 1 a multitude of several possible positions to place the filter stack 30 or the separate filter 31 in the optical path is shown to demonstrate different varieties of the system. One filter stack 30, or one separate filter 31 in any of those positions will suffice to filter NIR or other wavelength which might interfere with the green-blue-yellow spectrum most adapted to resolve the fine structures of a fingerprint. As can be seen with FIG. 1 the filter stack 30 symbolized by dash-dotted lines can be provided on the backside of the LED-array, on the front face, or the reverse side of the back plate 23, on any side of the transparent spacer 25 within the optical path, on a side of the lens 26 or on the front side of the sensor array 28. Alternatively, a separate filter 31 can be used between the cover plate 21 and the spacer 25, and as symbolized by two double arrows between the spacer and the lens, or between the lens 26 and the sensor 28. The filter can be a usual glass-plate provided with a respective filter stack on one of its surfaces. When using a mirror/sensor system (not shown) instead of a lens/sensor system, a filter stack may be also provided on the surface of the mirror.

[0038] FIG. 2 shows variations of a further embodiment with a one-piece cover plate 21 and an LED array 24 integrated on the reverse side showing two alternative positions for an NIR-filter stack 30. One position is again on the reverse side of the cover plate 21, in this case on the surface of an LED-array block, the other position again on the front side of the sensor array 28. A collimator 27, a pinhole array, or alternatively an optical waveguide can be used to guide the light from the cover plate 21 to the sensor 28. It should be mentioned that, as also shown by the same reference number, split and one-piece cover plates 21 from FIGS. 1 and 2A can be exchanged between the two alternative systems when designed to have the same optical properties.

[0039] Usually it would be expedient to apply filter stacks 30 deposited directly on a system component instead of using a separate filter. However such optical filters 31, due to their smaller dimension compared e.g. to the cover plate of a display, and the lack of potential sensitive electronic components as would be with a sensor, might be more efficient and cost effective to produce, especially when it comes to deposit highly sophisticated layer stacks of different materials in an expensive and volume-limited multi-chamber PVD-equipment.

[0040] In FIG. 3, which is a magnification of a section of the collimator 27 of FIG. 2, the use of a Filter 31 comprising an NIR-stack 30 at least at one of its surfaces is shown at two different positions of the collimator. On the left side the NIR-filter 31 is mounted on the side of the incident light and comprises a black coating 33 deposited here on the NIR-filter stack in areas covering the structure of the collimator shown with a grey background. Therewith optical resolution of reflected light coming from different regions of the fingerprint area 37 can be improved.

[0041] On the right side of FIG. 3 the filter 31 is mounted on the opposite side where the light leaves from the collimator 27 towards the sensor 28. In this embodiment the collimator is coated on the front side and within the through holes 34 with a black coating 33 which gives an even better light separation than with the structure as shown on the left side, however needs the coating of two different components as an additional cost issue in mass-production.

[0042] With reference to the complexity of the systems due to the necessity of focusing or aligning the reflected light as shown in FIG. 1 to 3, it should be mentioned that optical specifications of certain elements like spacer 25 or lenses 26 of the system according to the first embodiment or the collimator 27 with the second embodiment can be reduced, or such elements can be even omitted due to the better optical characteristic of the silver zinc oxide (titanium oxide) filters as used with the present invention. Therefore, with FIG. 1, lens 30 and/or spacer 25 could be omitted when such layer-filter is applied to the backside of the LED-array, on the front face, or the reverse side of the back plate 23, on the front side of the sensor array 28, or alternatively, a separate filter 31 is used between the cover plate 21 and the sensor 28. With FIG. 2 collimator 27 could be omitted when a layer-filter is used on the backside of the cover plate 21 or on the front side of the sensor 28, or a separate filter 31 in between as mentioned above.

[0043] This characteristic does not comprise higher transmittance and steeper and more defined filter edges only, see FIG. 11 to 12,14,15 but also an essentially reduced shift of the NIR-filter edge with reference to different angles of the incident light, see FIGS. 12 and 13 compared to FIG. 8 of a state of the art design.

[0044] Extensive experiments with pure dielectric stacks as preferably used for filters in the optics and photonics industries did not yield an essential improvement. As can be seen with FIG. 8, such dielectric filters show excellent transparency within the bandwidth gap and respective similar good acutance on both sides of it when analyzed with a 0° angle of incidence. It should be mentioned that a zero degree angle here refers to the standard measurement angle which is vertical to the substrate plane and any deviation is given with respect to the so called surface normal in accordance with usual technical language. However, when using a 60° angle (dashed line) the picture with the dielectric filter is very different. Transparency shows severe fluctuance within the bandwidth gap, edges show a loss of acutance and worst of all, the decisive upper filter-edge shows a shift of 77 nm from 609-532 nm which is a relative shift of about 13% and therewith out of any range for biometric applications which have to operate with light of different incident angles. Layer design of such a state of the art dielectric filter stack can be found with table 1. It consists of a sequence of alternating TiO.sub.2/SiO.sub.2λ/n-layers having a total layer thickness of about 1.5 μm.

[0045] Many material combinations have been tested also with mixed di-electric and silver stacks and have been analyzed with reference to their optical performance. However, absorption curves of SiO.sub.2/Ag and Si.sub.3N.sub.4/Ag layers as shown in FIG. 9 and FIG. 10 do not look very promising. Layer sequences of the respective coatings can be seen in table 2 and table 3.

[0046] However, surprisingly by use of a combination of metal oxide layers from ZnO.sub.x, AZO, GaZO and/or TiO.sub.x and silver layers tailored NIR-filter stacks having high transmission in the visible light band and good blocking properties for NIR-filters could be produced. At the same time UV-blocking properties are good enough to block harmful radiation from about 400 nm or lower wavelength. Due to the thin thickness of about one micrometer or even less, such coatings can be perfectly used with microelectronics components. Additional AR- and UV-blocking properties or higher transparency in the bandwidth gap and better edge acutance could be added by use of dielectric stacks 11 which can be also arranged directly on the substrate S or seed layer 1′ as a further dielectric stack 13, be sandwiched between further ZnO.sub.xlayer(s) and/or a further TiO.sub.X layer, e.g. stack 14, and/or be placed on top of the basic NIR blocking stack 12.

[0047] Some principles on such coating set-ups are shown in FIG. 4 to FIG. 7. Realized examples and set-ups are shown in tables 4 to 6 and in FIG. 9 to FIG. 15. FIG. 4 to FIG. 7 show in an exemplary manner different set ups of a stack comprising an NIR-blocking stack 12 comprising at least two silver layers 2,4 separated by a ZnO.sub.x layer 3,5 which can be an AZO layer.

[0048] In detail the optical filter is a layered near infrared (NIR) filter consisting of [0049] at least one of an inner ZnO.sub.x 1 and/or an inner TiO.sub.xlayer 1 at a substrate S side which may comprise also a seed layer 1′, that is the innermost layer deposited directly on the surface of the substrate S; [0050] followed by a multitude of silver layers 2, 4, each silver layer 2 being separated from each neighbouring silver layer 4 by at least one of a further ZnO.sub.x layer 3 and/or a further TiO.sub.X layer 3; [0051] at least one of an outer ZnO.sub.x layer 5, an outer TiO.sub.xlayer 5, and/or an oxygen blocking layer 6 deposited directly or alternatingly on the outermost silver layer 4.

[0052] It should be mentioned that blocking stack 12 shows two silver 2,4 and respective ZnO.sub.x layers 1,3,5 only for reasons of clearness, whereas filters from 2 to 6 silver layers, especially from 3 to 5 silver layers can be used to optimize the respective filter designs, see e.g. FIG. 11 to 15.

[0053] With reference to the inner further or outer TiO.sub.x layers, the latter may be also a blocking layer, good optical properties could be reached when alternating TiO.sub.x/ZnO.sub.x/Ag/TiO.sub.x/ZnO.sub.x/Ag layers where used as exemplarily shown in table 5.

[0054] The minimum layer stack ends with the outermost blocking layer 6. In this case the layer furthermost from the substrate, which may consist of at least one of TiO.sub.X, ZnO.sub.x, SnO.sub.x, CryO.sub.x and/or NiCrO.sub.x. The blocking layer 6 can be used on top of outer metal oxide layer 5 as shown or may replace the outer metal oxide layer 5.

[0055] With reference to the deposition of the layer stack which can be performed e.g. by sputtering, it should be mentioned that it is important to provide as an interface a metallic layer of one or a few nanometers at each side of the silver layer 2, 4 to avoid any oxidation of the silver surface which would influence optical properties like reflexivity of the silver layer. Such metallic interface layers are illustrated in dotted lines in FIG. 6 and may consist of Ti, Zn, Sn, Cr, NiCr, depending on the respective neighbouring metal oxide layer 1, 3, 5 or 6 which may consist of TiO.sub.x, ZnO.sub.X, SnO.sub.X, Cr.sub.yOX or NiCrO.sub.x as mentioned above. Therewith metal-oxide layers can comprise substoichiometric regions or sublayers 1″, 3″, at least at the silver side(s) of the metal oxide layers 1, 3, 5, 6 whereas other regions or sublayers 1′, 3′ may be stoichiometric or nearly stoichiometric.

[0056] In a further embodiment of the invention the NIR-filter may comprise a dielectric stack 11 consisting of alternating high and low refractive layers deposited on one of the following layers: the outer ZnO.sub.x layer, the outer TiO.sub.xlayer, or the blocking layer whereby antireflective (AR) properties of the filter can be optimized and sharp filter edges can be realized. This stack will consist of at least four layers however may have essentially more.

[0057] Further tuning or improving optical properties of the filter may comprise an embodiment of the invention having a SiO.sub.2 layer, which is a low index material layer, or a stack 14 of alternating SiO.sub.2 and at least one high index layer consisting of high index material sandwiched between two further metal oxide layers, whereat each of the two further metal oxide layers is in direct contact to a or to the SiO.sub.2 layer, and is adjacent to a respective silver layer with its side facing away from the sandwiched SiO.sub.2 layer(s). The high index material may consist of Ta.sub.2O.sub.5, TiO.sub.2, Nb.sub.2O.sub.5, HfO.sub.2, ZrO.sub.2 or Si.sub.3N.sub.4 and the sandwiched stack may be a three layer stack consisting of two SiO.sub.2 layers and a high index layer again sandwiched between the two SiO.sub.2 layers.

[0058] FIGS. 4, 6 and 7 show substrates having respective layer stack(s) provided at the side of the incident light, whereas FIG. 5 shows a substrate having the layer stack(s) at the side where the light, symbolized by arrows in FIGS. 4 and 5, leaves the component on the optical path towards the sensor. With the exception of an optional seed layer 1′, which has to be provided at the substrate surface, e.g. to improve adhesion, the layer sequence can be the same with reference to the substrate surface, which in this case is inverse with reference to the light direction, due to the additive nature of the optical layer properties.

[0059] With FIG. 7 material combinations for low refractive materials, like SiO.sub.2, Al.sub.2O.sub.3, or MgF.sub.2, and of high refractive materials, like TiO.sub.2, Ta.sub.2O.sub.5, or ZrO.sub.2, Si.sub.3N.sub.4, are given. A further AR-stack 13 is shown which can be provided directly on the substrate S or seed layer 1′ to enforce AR properties of AR-stack 11. Additional UV-damping or UV-blocking effects may be added by further AR-stack 13 too.

[0060] Examples of a respective NIR-filter stacks are given in tables 4 to 7 and FIG. 11 to 15, wherein table: Table 4 refers to FIGS. 11 and 12 showing the optical properties of coating design 2, and to FIG. 13 showing respective properties of design 1;

[0061] Both designs are relatively simple NIR-filters consisting of four alternating AZO or GaZO/Ag layers completed with an outer AZO or GaZO layer, having a physical layer thickness between 50 and 200 nm, which is thin. The only relevant difference is the physical thickness of certain AZO or GaZO layers, especially of the inner AZO or GaZO layer nearest to the substrate, which is thicker with design 2. Therewith in comparison of FIGS. 12 and 13 a slightly better transparency of the thinner design 1 results in a wavelength range between 450 to 500 nm, whereas design 2 shows a better uniformity in the transparent region and filter edges being better defined on both sides. Additional to a 0° measurement, a measurement using light in an angle of 60° to the surface normal of the two test samples has been taken. The results at half width of the maximum were for design 1 (FIG. 13) 0°->60° : 608->581 nm or 4.8%; for design 2 (FIG. 12) 0°->60° : 614->586 nm or 4.6%;

[0062] As can be seen a shift of the NIR edge of smaller 30 nm which is smaller than 5% could be reached in case of both designs, whereas the shift of the UV-edge was nearly neglectable. Design 2 again yielded a better uniformity. In view of the considerable different angle of the 60° measurement this minor change seems to be quite satisfying.

[0063] FIG. 11, in addition to the transparency of design 2 also shows the respective absorption R in comparison.

[0064] All photospectrometric measurements have been taken with a PhotonRT spectrometer by Essen-Optics. Optical samples have been deposited on a 200 mm glass of the D263-type in a commercial CLN 200 BPM-equipment from Evatec AG, Switzerland. Examples of the process parameters as used can be found in table 8. The same equipment and comparable process parameters have been used to produce respective filters on various components in the optical path as described above.

[0065] Table 5 refers to coating design 3 comprising an alternating TiO.sub.x/ZnO.sub.x/Ag/TiO.sub.x/ZnO.sub.x/Ag . . . layer not shown in the figures.

[0066] Table 6 refers to design 4 to 7, all in a medium thickness range between about 200 and 1000 nm, where optical transmittance of designs 5 to 7 is shown in FIG. 14.

[0067] Medium NIR-filters as shown in FIG. 14 give a good survey how edges and uniformity can be influenced with filters having three (design 5), four (design 6), and five (design 7) silver layers, each of about 20 nm thickness.

[0068] Table 7 refers to designs 10 to 12, all in a thick thickness range between about 1000 and 2500 nm, where optical transmittance of designs 5, 10, 11 and 12 is shown in FIG. 15. Additional layer thickness here comes primarily from the AR-stack, in this case an alternating Ta.sub.2O.sub.5/SiO.sub.2 stack, and in part of a single further AR-stack, consisting of a Ta.sub.2O.sub.5-layer, directly deposited on the substrate and a consecutive SiO.sub.2-layer on top of the NIR-filter. As can be seen with FIG. 15 transmission and steepness of the filter edge could be further improved with reference to the medium thickness design 5. Similar results could be achieved with comparable other high/low-index combinations like TiO.sub.2/SiO2, TiO.sub.2/Al.sub.2O.sub.3, or else as mentioned above.

[0069] For many biometric authentication systems, especially fingerprint identification systems, less sophisticated designs in the middle or even low thickness range will suffice to analyze the pattern produced by the object, e.g. the fingerprint, with good resolution.

[0070] Finally, it should be mentioned that a combination of features mentioned with one embodiment, examples or types of the present invention can be combined with any other embodiment, example or type of the invention unless being obviously in contradiction.

TABLE-US-00001 TABLE 1 Dielectric NIR blocker Design TiO2/SiO2 Layer Material d phy Substrate Glass [nm] 1 TiO2 113.0 2 SiO2 199.3 3 TiO2 27.3 4 SiO2 194.5 5 TiO2 39.079 6 SiO2 174.594 7 TiO2 46.325 8 SiO2 182.919 9 TiO2 22.295 10 SiO2 118.103 11 TiO2 90.460 12 SiO2 100.307 13 TiO2 79.260 14 SiO2 132.583 15 TiO2 54.900 16 SiO2 146.308 17 TiO2 62.980 18 SiO2 133.970 19 TiO2 75.102 20 SiO2 58.245 TiO2 609.8 SiO2 490.8 Σ 1446.9

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[0071]

TABLE-US-00002 TABLE 2 SiO.sub.2/Ag Design SiO2/Ag Layer Material d phy Substrate Glass [nm] 1 SiO2 115.8 2 Ag 21.3 3 SiO2 115.8 4 Ag 21.3 5 SiO2 115.8 6 Ag 21.3 7 SiO2 115.8 8 Ag 21.3 9 SiO2 115.8

TABLE-US-00003 TABLE 3 Si.sub.3N.sub.4/Ag Design Si3N4/Ag Layer Material d phy Substrate Glass [nm] 1 Si3N4 73.6 2 Ag 21.3 3 Si3N4 73.6 4 Ag 21.3 5 Si3N4 73.6 6 Ag 21.3 7 Si3N4 73.6 8 Ag 21.3 9 Si3N4 73.6

TABLE-US-00004 TABLE 4 NIR-blocker 1-2 Design 1 Design 2 Layer Material d phy d phy Substrate Glass [nm] [nm] 1 AZO/GaZO 23.3 45.8 2 Ag 16.6 15.0 3 AZO/GaZO 66.9 79.6 4 Ag 19.3 24.0 5 AZO/GaZO 70.5 71.2 6 Ag 20.8 22.4 7 AZO/GaZO 72.5 81.5 8 Ag 20.8 22.9 9 AZO/GaZO 39.7 39.1 Σ d Agx4 77.5 84.3 Σ d AZO/GaZO 272.9 317.1 x5 Σ total d 350.4 401.5

TABLE-US-00005 TABLE 5 NIR-blocker 3 Design 3 Layer Material d phy Substrate Glass [nm] 1 TiO2 21.146 2 ZnO 6.0 3 Ag 21.1 4 TiO2 55.4 5 ZnO 6 6 Ag 20.0 7 TiO2 52.2 8 ZnO 6 9 Ag 23.4 10 TiO2 28.2

TABLE-US-00006 TABLE 6 NIR-blocker 4-7 Design Design Design Design 4 5 6 7 Layer Material d phy d phy d phy d phy Substrate Glass [nm] [nm] [nm] [nm] 1 ZnO 34.1 35.2 37.8 30.4 2 Ag 17.4 18.0 18.0 19.7 3 ZnO 73.0 74.5 76.7 74.7 4 Ag 20.2 18.1 18.0 18.7 5 ZnO 67.8 68.9 70.2 72.1 6 Ag 19.0 20.8 21.4 22.0 7 ZnO 58.0 74.2 73.3 32.8 8 Ag 11.5 18.9 18.6 — 9 ZnO 10.0 35.7 76.3 — 10 Ag — — 18.0 — 11 ZnO — — 38.3 —

TABLE-US-00007 TABLE 7 NIR-blocker (+AR) 10-12 Design Design Design 10 11 12 Layer Material d phy d phy d phy Substrate Glass nm nm nm 1 Ta2O5 121.1 126.9 89.2 2 SiO2 77.7 61.4 121.2 3 ZnO 55.1 56.6 79.3 4 Ag 12.0 12.0 50.4 5 ZnO 79.9 80.1 12.0 6 Ag 18.4 18.4 78.9 7 ZnO 73.0 75.0 18.4 8 Ag 23.2 23.2 77.5 9 ZnO 69.7 69.7 23.2 10 Ag 15.0 15.0 69.2 11 ZnO 131.8 135.1 15.0 12 Ta2O5 90.2 94.1 137.3 13 SiO2 90.4 67.7 91.4 14 Ta2O5 118.6 140.4 83.7 15 SiO2 65.5 63.6 121.7 16 Ta2O5 150.6 125.1 63.1 17 SiO2 201.0 87.9 143.5 18 Ta2O5 53.7 90.4 63.4 19 SiO2 — 91.4 127.6 20 Ta2O5 — 128.4 81.1 21 SiO2 — 195.6 131.9 22 Ta2O5 — 56.5 18.1 23 SiO2 — — 174.0 24 Ta2O5 — — 67.0 25 SiO2 — — 152.6 26 Ta2O5 — — 177.9 27 SiO2 — — 78.9 Σ d Ag 4x 68.6 68.6 68.6 Σ d ZnO 277.7 281.4 276.0 (AZO/GaZO) Σ d Ta2O5 609.8 768.1 812.8 Σ d SiO2 490.8 696.3 1190.0 Σ d total 1446.9 1814.4 2347.4

TABLE-US-00008 TABLE 8 Process parameters.sup.+ Layer-Material Process Process Parameters ZnO.sub.x, ZnO.sub.x:Al React. RF or DC- O.sub.2 and inert gas (Ar), p: 1 × 10.sup.−4 − 9 × 10.sup.−3 mbar, pulsed or DC or AC- 0.2-20 kW/cathode.sup.++; MF sputter Ag DC-pulsed or DC Inert gas (Ar) only, p: 1 × 10.sup.−4 − 9 × 10.sup.−3 mbar, 0.2-20 kW/cathode.sup.++; Ti, or Ti O.sub.sub, or NiCr, React. or not- Inert gas (Ar) + O.sub.2 facult. (e.g. metallic) or NiCrO.sub.sub reactive RF- or DC- targets, p: 1 × 10.sup.−4 − 9 × 10.sup.−3 mbar, pulsed or DC or AC- 0.2-20 kW/cathode.sup.++; MF sputter Ta.sub.2O.sub.5 React. RF- or DC- O.sub.2 and inert gas (Ar), p: 1 × 10.sup.−4 − 9 × 10.sup.−3 mbar, pulsed or DC or AC- 1-20 kW/cathode.sup.++; MF sputter. SiO.sub.x React. RF- or DC- O.sub.2 and inert gas (Ar), p: 1 × 10.sup.−4 − 9 × 10.sup.−3 mbar, pulsed or DC or AC- 1-20 kW/cathode.sup.++; MF sputter. .sup.+All processes for test glasses and filters have been produced on a commercially available Evatec vacuum equipment of the type: CLN 200 BPM, MSP, Solaris and/or LLS; .sup.++Planar cathodes with target dimensions circular 200-450 mm or rectangular 1 × b = 35 − 85 × 13 cm, were used for all experiments, rotatable cathode targets can be used as well.

Reference Numbers

[0072] 1′ seed layer [0073] 1 ZnO.sub.x, AZO, GaZO [0074] 2 Ag [0075] 3 ZnO.sub.x, AZO, GaZO [0076] 4 Ag [0077] ZnO.sub.x, AZO, GaZO [0078] 6 TiO.sub.X, ZnO.sub.x, SnO.sub.x, NiCrO.sub.x [0079] 7 dielectric stack [0080] 10 TiO.sub.2, Ta.sub.2O.sub.5, ZrO.sub.2, Si.sub.3N.sub.4 [0081] 11 AR-stack (dielectric) [0082] 12 NIR blocking layer stack [0083] 13 further AR-stack (dielectric) [0084] 14 SiO.sub.2 layer or stack of SiO.sub.2/high index/ . . . /SiO.sub.2 layers [0085] 20 fingerprint identification system type I [0086] 21 cover plate [0087] 22 front plate [0088] 23 back plate [0089] 24 LED module, e.g. OLED [0090] 25 transparent spacer with low RI [0091] 26 lens [0092] 27 collimator/pinhole array/optical waveguide [0093] 28 sensor or sensor array [0094] 29 separate light source [0095] 30 NIR-filter stack [0096] 31 separate filter with NIR-filter on one side [0097] 32 controller unit [0098] 33 absorption layer [0099] 34 collimator through hole [0100] 35 boundary of the optical path [0101] 36 finger [0102] 37 fingerprint area [0103] 40 fingerprint identification system type II