DATA READOUT DEVICE FOR READING OUT DATA FROM A DATA CARRIER

Abstract

A data readout device (114) for reading out data from at least one data carrier (112) having data modules (116) located at least two different depths within the at least one data carrier (112) is disclosed. The data readout device (114) comprises: at least one illumination source (122) for directing at least one light beam (124) onto the data carrier (112); -at least one detector (130) adapted for detecting at least one modified light beam modified by at least one of the data modules (116), the detector (130) having at least one optical sensor (132), wherein the optical sensor (132)has at least one sensor region (134), wherein the optical sensor (132)is designed to generate at least one sensor signal in a manner dependent on an illumination of the sensor region (134)by the modified light beam, wherein the sensor signal, given the same total power of the illumination,is dependent on a beam cross-section of the modified light beam in the sensor region (134); and -at least one evaluation device (136) adapted for evaluating the at least one sensor signal and for deriving data stored in the at least one data carrier (112) from the sensor signal. Further, a data storage system (110), a method for reading out data from at least one data carrier (112) and a use of an optical sensor (132) for reading out data are disclosed.

Claims

1. A data readout device for reading out data from at least one data carrier having data modules located at at least two different depths within the at least one data carrier, the data readout device comprising: at least one illumination source for directing at least one light beam onto the data carrier; at least one detector adapted for detecting at least one modified light beam modified by at least one of the data modules, the detector having at least one optical sensor, wherein the optical sensor has at least one sensor region, wherein the optical sensor is designed to generate at least one sensor signal in a manner dependent on an illumination of the sensor region by the modified light beam, wherein the sensor signal, given the same total power of the illumination, is dependent on a beam cross-section of the modified light beam in the sensor region; and at least one evaluation device adapted for evaluating the at least one sensor signal and for deriving data stored in the at least one data carrier from the sensor signal.

2. The data readout device according to claim 1, wherein the data modules are reflective data modules, wherein the light beam directed onto the data carrier is modified by being reflected by at least one of the reflective data modules.

3. The data readout device according to claim 1, wherein a transmitted light beam is generated by at least one of the data modules being capable of modifying the light beam directed onto the data carrier, wherein a transfer device focuses the light beam onto one of the depths where the data modules are located.

4. The data readout device according to claim 3, wherein the detector further comprises at least one further transfer device adapted for transferring the modified light beam to the at least one optical sensor.

5. The data readout device according to claim 1, wherein the evaluation device is adapted to determine the depth of the data module from which the modified light beam originates, by evaluating the at least one sensor signal.

6. The data readout device according to claim 5, wherein the evaluation device is adapted to use at least one known correlation between the at least one sensor signal and the depth of the data module from which the modified light beam originates.

7. The data readout device according to claim 1, wherein the optical sensor is an organic photodetector.

8. The data readout device according to claim 1, wherein the optical sensor comprises at least one photosensitive layer setup, the photosensitive layer setup having at least one first electrode, at least one second electrode and at least one photovoltaic material sandwiched in between the first electrode and the second electrode, wherein the photovoltaic material comprises at least one organic material.

9. The data readout device according to claim 1, wherein the detector comprises a sensor stack of at least two optical sensors.

10. The data readout device according to the claim 9, wherein at least one optical sensor of the sensor stack is at least partially transparent.

11. The data readout device according to claim 9, wherein the evaluation device is adapted to evaluate at least the sensor signals generated by at least two of the optical sensors of the sensor stack.

12. The data readout device according to claim 11, wherein the evaluation device is adapted to derive at least one beam parameter from the at least two sensor signals generated by the at least two optical sensors of the sensor stack.

13. The data readout device according to claim 1, wherein the illumination source is adapted to generate at least two different light beams having different colors.

14. The data readout device according to claim 13, wherein the detector is adapted for distinguishing reflected light beams having different colors.

15. The data readout device according to claim 14, wherein the detector comprises at least two optical sensors having differing spectral sensitivities.

16. A data storage system, comprising: at least one data readout device according to claim 1, the data storage system further comprising at least one data carrier having data modules located at at least two different depths within the at least one data carrier.

17. The data storage system according to claim 16, wherein the data carrier comprises a layer setup, the layer setup having at least two different information layers, wherein the data modules are located in the at least two different information layers.

18. The data storage system according to claim 16, wherein the data storage system comprises a data carrier stack of at least two data carriers.

19. A method for reading out data from at least one data carrier, the method comprising: a) providing at least one data carrier having data modules located at at least two different depths within the at least one data carrier; b) providing a data readout device comprising: at least one illumination source for directing at least one light beam onto the data carrier; at least one detector adapted for detecting at least one modified light beam modified by at least one of the data modules, the detector having at least one optical sensor, wherein the optical sensor has at least one sensor region, wherein the optical sensor is designed to generate at least one sensor signal in a manner dependent on an illumination of the sensor region by the modified light beam, wherein the sensor signal, given the same total power of the illumination, is dependent on a beam cross-section of the reflected light beam in the sensor region; and c) evaluating the at least one sensor signal and deriving data stored in the at least one data carrier from the sensor signal.

20. (canceled)

Description

BRIEF DESCRIPTION OF THE FIGURES

[0261] Further optional details and features of the invention are evident from the description of preferred exemplary embodiments which follows in conjunction with the dependent claims. In this context, the particular features may be implemented alone or with several in combination. The invention is not restricted to the exemplary embodiments. The exemplary embodiments are shown schematically in the figures. Identical reference numerals in the individual figures refer to identical elements or elements with identical function, or elements which correspond to one another with regard to their functions.

[0262] Specifically, in the figures:

[0263] FIG. 1 shows a schematic setup of an embodiment of a data storage system including a data readout device and a data carrier;

[0264] FIG. 2 shows a schematic cross-sectional view of an embodiment of a detector and an evaluation device to be used in the data storage system of FIG. 1;

[0265] FIG. 3 shows an alternative embodiment of a data storage system including a data readout device and a data carrier;

[0266] FIG. 4 shows a schematic setup of an embodiment of a data storage system including a data readout device and a data carrier stack; and

[0267] FIG. 5 shows an alternative schematic setup of an embodiment of a data storage system including a data readout device and a data carrier stack.

EXEMPLARY EMBODIMENTS

[0268] In FIG. 1, in a schematic view, an exemplary embodiment of a data storage system 110 is depicted. The data storage system 110, in this embodiment, includes a data carrier 112 and a data readout device 114, the latter of which having a plurality of components.

[0269] The data carrier 112 comprises a plurality of data modules 116 being, in this particular example, at least partially reflective data modules 116, which are symbolically depicted in FIG. 1. As an example, the data modules 116 may be arranged in information layers 118 which may be coated onto and/or embedded into a matrix material 120. As an example, the matrix material 120 may be or may comprise a transparent plastic material such as polycarbonate. The information layers 118 each, independently, may contain one or more thin metallic layers, such as aluminum layers, such as aluminum layers having a thickness in the range of 20 to 150 nm. For manufacturing of the information layers 118, reference may be made to technologies used in CD, DVD or Blu-ray technology. Thus, specifically, the layer setup of the data carrier 112 may correspond to a data carrier stack of CD, DVD or Blu-ray devices. The data modules 116 may be written by using known technologies, such as one or more of embossing, stamping, molding or writing by using optical technologies, such as laser writing. Specifically, known mastering technologies may be used. Therein, mastering generally refers to the process of creating a stamper or set of stampers to be used for molding, such as for injection molding. This technology is, as an example, known from CD manufacturing. Generally, for example, the data modules 116 and/or the surroundings may be created as pits and lands or grooves and lands. During the process of manufacturing, specifically during the process of mastering, a digital signal, such as a digital signal originating from a computer, may be used to guide a laser beam which etches a pattern, such as a pattern of pits and lands and/or a pattern of one or more continuous grooves onto a highly polished glass disc coated with photoresist. In addition, one or more of a curing step, a developing step and/or a rinsing step may be applied, in order to create a class master. Further, a metal mold, such as nickel and/or silver, may be electroformed on top. This mold may be removed and then electroplated with a metal, such as a nickel alloy, in order to create one or more stampers to be used in a subsequent molding process, such as in an injection molding machine, to press the data into the matrix material, such as into a polycarbonate substrate. This technology generally is known to the skilled person in the art of manufacturing of optical storage disks. Still, other technologies may be used such as direct writing.

[0270] The data readout device 114 as depicted in FIG. 1 further includes at least one illumination source 122. The illumination source 122, as an example, may be or may comprise at least one illumination source for generating collimated light, preferably coherent light, such as a laser L. As an example, wavelengths in the visible spectral range may be used, such as wavelengths as currently used for CD, DVD or Blu-ray technology, such as one or more of the wavelengths 780 nm, 650 nm or 405 nm. Thus, basically, the illumination source 122 as used in the present invention may correspond to commercially available illumination sources as used in CD, DVD or Blu-ray technology.

[0271] The illumination source 122 is adapted for generating at least one light beam 124 which is directed onto the data carrier 112, as symbolically depicted in FIG. 1. The light beam 124 is, at least partially, reflected by the data modules 116 of the information layers 118 which are arranged in different depths d.sub.1, d.sub.2 and d.sub.3 within the data carrier 112. Thereby, one or more reflected light beams 126 are generated, which may be separated from the incident light beam 124 by one or more beam-splitting devices 128 and which may be directed towards at least one detector 130 of the data readout device 114.

[0272] The detector 130 comprises at least one optical sensor 132, as schematically depicted in FIG. 1. The optical sensor 132 has a sensor region 134 and is designed to generate at least one sensor signal in a manner dependent on an illumination of the sensor region 134 by the reflected light beam 126. The sensor signal, given the same total power of illumination, is dependent on a beam cross-section of the reflected light beam 126 in the sensor region 134. As outlined in further detail above, this effect generally is referred to as the FiP effect.

[0273] For potential setups of the optical sensor 132, reference may be made, as an example, to one or more of WO 2012/110924 A1 and WO 2014/097181. Thus, as an example, the layer setup of the at least one optical sensor 132 may correspond to one or more of the layer setups of the longitudinal optical sensors disclosed in WO 2014/097181. Additionally or alternatively, reference may be made to setup shown in FIGS. 2 and 3 of WO 2012/110924 A1, as well as to the corresponding description of these Figures in the specification. It shall be noted, however, that other layer setups are feasible. To increase the FiP effect, one or both of the light beam 124 or the reflected light beam 126 may be modulated, such as by modulating the illumination source 122 and/or by providing an additional modulation device as disclosed above.

[0274] As is evident from the different depths d.sub.1, d.sub.2 and d.sub.3 of the information layers 118 within the data carrier 112, the optical path length of the light beams 124, 126, which is the total optical path length passed by these light beams 124, 126 between the illumination source 122 and the detector 130, varies dependent on the depth of the respective data module 116 by which the light beam 124 is reflected. Thus, light reflected by data modules 116 of the uppermost information layer having a depth d.sub.1 travels over a distance 2 d.sub.1 through the data carrier 112. Contrarily, light reflected by the deepest information layer 118 having a depth d.sub.3 travels a distance 2 d.sub.3 through the data carrier 112, which is increased by 2 (d.sub.3d.sub.1) as compared to the uppermost information layer 118.

[0275] Due to the propagation properties of light beams 124, 126, however, the beam properties of the reflected light beam 126 are changed due to this additional optical path length. Thus, specifically, a beam waist of the reflected light beam 126, at the sensor region 134 of the optical sensor 124, changes due to this variation of the depth of the data modules 116. This variation in beam shape, specifically this variation in the beam cross-section of the reflected light beams 126, however, is detectable by the above-mentioned FiP effect. Thus, the at least one sensor signal generated by the at least one optical sensor 132 is dependent on the beam cross-section, and, thus, is dependent on the depth of the respective data modules 116 by which the light beam 124 is reflected. Consequently, by evaluating the at least one sensor signal, the depth of the respective data module 116 may be determined.

[0276] For evaluating the at least one sensor signal and for deriving data stored in the data carrier 112, the data readout device 114 comprises at least one evaluation device 136. The evaluation device 136, as an example, may be connected to the detector 130. The evaluation device 136 may further control the illumination source 122 and/or may control one or more actuators 138 which will be explained in further detail below. Thus, as an example, the evaluation device 136 may be adapted for evaluating the at least one sensor signal for detecting data modules 116. Further, for each detected data module 116, a depth of the data module 116 may be derived, such as by using a known correlation between the sensor signal and the depth. For examples of these correlations, reference may be made to the so-called FiP curves, as e.g. shown in one or more of the prior art documents mentioned above, such as in FIG. 4 of WO 2012/110924 A1.

[0277] The data modules 116 may be partially transparent such that light in various depths of the data carrier 112 may be detected spontaneously, without the need of refocusing the illumination source 122.

[0278] As outlined above, the data storage system 110 and, specifically, the data readout device 114 may further comprise additional components. Thus, as already mentioned, at least one actuator 138 may be present, for inducing at least one translational and/or rotational relative movement 140 of the data carrier 112 and the data readout device 114 or parts thereof. Thus, the data carrier 112 may be moved and/or the data readout device 114 or parts thereof may be moved in order to scan the data carrier 112 with the at least one light beam 124. Actuators 138 are generally known from CD, DVD or Blu-ray technology.

[0279] In FIG. 2, a cross-sectional view of a potential setup of the detector 130 is shown, in a plane parallel to an optical axis 142 of the detector 130.

[0280] Firstly, as symbolically depicted in FIG. 2, the detector 130 may comprise at least one transfer device 144 for directing and/or shaping the at least one reflected light beam 126. As an example, the transfer device 144 may comprise at least one lens or lens system 146.

[0281] In this regard, it shall be noted that the setup of the data readout device 114 and the data storage system 110 as e.g. depicted in FIG. 1, generally may comprise one or more transfer devices 144 such as one or more lenses 146 or lens systems. Thus, as an example and as depicted in FIG. 1, one or more lenses 146 may be provided in the beam path of light beam 124, such as for focusing the incident light beam 124 before illuminating the data carrier 112. Additionally or alternatively, one or more lenses 146 or lens systems may be provided in the beam path of the reflected light beam 126, wherein the one or more lenses 146 may fully or partially be part of the detector 130 and/or may fully or partially be embodied independent from the detector 130. Further, optionally, one or more additional optical elements may be provided, such as one or more reflective elements and/or one or more diaphragms, such as for beam-shaping or other optical purposes.

[0282] Symbolically depicted by the dotted, the dashed and the solid lines of the three exemplary reflected light beams 126, symbolically representing three different optical path lengths and, thus, symbolically depicting reflections from data modules 116 at different depths within the data carrier 112, focal points F.sub.1, F.sub.2 and F.sub.3 are shifted in the direction of the optical axis 142 for these three different reflected light beams 126. Consequently, when measured at an arbitrary point along the optical axis 142, a beam cross-section of these light beams 126 changes, which may be detected by using the above-mentioned FiP effect and by evaluating sensor signals of these optical sensors 132 by using the evaluation device 136. Thus, by evaluating these sensor signals, in addition to the actual information value stored within each data module 116 read out by the data readout device 114, the depth of the respective data module 116 may be determined as an additional item of information.

[0283] As further depicted in the schematic setup of FIG. 2, optionally, one or more than one optical sensor 132 may be provided in the detector 130. Thus, as shown in FIG. 2, a sensor stack 148 of optical sensors 132 may be provided. The sensor signals of the optical sensors 132 of the sensor stack 148 may be evaluated. The use of a plurality of optical sensors 132, such as the use of the sensor stack 148, may be advantageous in many ways. Thus, as an example, ambiguities in the evaluation of the sensor signals may be resolved which generally may originate from the optical fact that a beam cross-section of a light beam, at a given distance before or after a focal point, is typically identical. Thus, by evaluating the sensor signals at more than one coordinate along the optical axis 142, these ambiguities may be resolved, as explained e.g. in WO 2014/097181. Thus, generally, by evaluating the sensor signals, beam parameters of the reflected light beams 126 may be generated. Further, the optical sensors 132 of the sensor stack 148 may have identical spectral properties or may provide differing spectral properties. Thus, as an example, the sensor stack 148 may comprise at least two different types of optical sensors 132 having differing spectral sensitivities, such as in an alternating arrangement. Thereby, colors of the reflected light beam 126 may be resolved. As an example, the illumination source 122 may be adapted for generating a plurality of light beams 124 having different colors, and the detector 130, in conjunction with the evaluation device 136, may be arranged for resolving these different colors.

[0284] The evaluation device 136, in one or more of the embodiments shown herein and/or in other embodiments of the present invention, may comprise one or more interfaces 150. As an example, the one or more interfaces 150 may be wire-bound and/or wireless interfaces. By using these one or more interfaces 150, data read out from the data carrier 112 may be provided to other devices. Thus, the data storage system 110 and/or the data readout device 114 may be implemented into a computer or a computer system or may be used as a stand-alone device.

[0285] In the setup of the data readout device 114 and the data storage system 110 as depicted in FIG. 1, the reflected light beam 126 may fully or partially propagate along the beam path of the incident light beam 124, before being separated off by the beam-splitting device 128. It shall be noted, however, that other setups of the beam paths are feasible. Thus, as an example, optical reflections from a front surface or a back surface of the data carrier 112 may be detrimental to the measurement. These reflections generally may occur in case the incident light beam 124 is oriented perpendicular to these surfaces. Further, generally, interference effects may occur, which generally may be due to the preferred collimated and coherent nature of the light beam 124.

[0286] Therefore and in order to avoid these and other detrimental optical effects, it may be preferable to use and optical setup in which incident light beam 124 hits the surface of the data carrier 112 at an angle other than 90, i.e. in an oblique fashion. Further, it may be preferable to avoid a setup in which the reflected light beam 126 propagates along the beam path of the incident light beam 124.

[0287] An exemplary setup of this kind is shown in FIG. 3. Therein, a data storage system 110, a data carrier 112 and a data readout device 114 are shown which generally correspond to the exemplary embodiment shown in FIG. 1. Thus, for most details of the setup, reference may be made to FIG. 1 and the description of FIG. 1 given above.

[0288] In the setup of FIG. 3, the incident light beam 124 hits a front surface 152 of the data carrier 112 at an angle a between 0 and 90, such as at an angle between 10 and 85 or between 30 and 75. Thereby, the above-mentioned interference effects between incident light beam 124 and reflected light beam 126 may be avoided. Further, unwanted internal reflections within the data carrier 112 and interference effects induced thereby may be suppressed. Further, the use of a beam-splitting device 128 may be avoided in the setup, even though the use of one or more beam-splitting devices is still possible.

[0289] FIG. 4 shows, in a schematic view, an exemplary embodiment of a further data storage system 110. In this particular embodiment, the data storage system 110 comprises a data readout device 114 and a plurality of data carriers 112 which are arranged in form of a data carrier stack 154. Herein, each of the plurality of the data carriers 112 comprises at least one of the at least partially reflective data modules 116 within the information layers 118. Exemplary, three individual data carriers 112 each comprising a single data module 116 are symbolically depicted in FIG. 4. Herein, each of the plurality of the data carriers 112 may comprise one of a DVD, a CD or a Blu-ray device.

[0290] Especially for providing an optimized optical path for the light beam 124 which traverses the data carrier stack 154, a thin film 156 of an optically transparent adhesive 158 is applied in this particular embodiment between two adjacent the data carriers 112 within the data carrier stack 154. Herein, the adhesive 158 preferably exhibits a refraction index which may be equal or similar to the refraction index of the matrix material 120 as used in the data carriers 112 being placed in an adjacent manner with respect to the thin film 156. In particular by carefully selecting the corresponding refraction indices, the incident beam 124 can, thus, traverse the data carrier stack 154 with only a negligible refraction.

[0291] The illumination source 122 is adapted for generating at least one light beam 124 which is directed onto the plurality of the data carriers 112 within the data carrier stack 154, as symbolically depicted in FIG. 1. Herein, the light beam 124 is, at least partially, reflected by the data modules 116 of the information layers 118 which are arranged in different data carriers 112 which, due to their spatial extent, are located at three different longitudinal positions, i.e. at the depths d.sub.1, d.sub.2 and d.sub.3.

[0292] The hereby generated reflected light beams 126 may be separated from the incident light beam 124 by one or more beam-splitting devices 128 and directed towards the at least one detector 130 of the data readout device 114. As symbolically depicted in FIG. 4, the detector 130 may comprise at least one transfer device 144 for directing and/or shaping the at least one reflected light beam 126. As an example, the transfer device 144 may comprise at least one lens or lens system 146.

[0293] In this example, the detector 130 comprises a sensor stack 148 of optical sensors 132, wherein the sensor signals of the optical sensors 132 of the sensor stack 148 may be evaluated by the evaluation device 136. As described above, each of the optical sensors 132 in the sensor stack 148 has a sensor region 134 and is designed to generate at least one sensor signal in a manner dependent on an illumination of the sensor region 134 by the reflected light beam 126. The sensor signal, given the same total power of illumination, is dependent on a beam cross-section of the reflected light beam 126 in the sensor region 134. According to this FiP effect, the sensor signal of each optical sensor 132, which may, preferably comprise a photocurrent i, is dependent on the photon flux F, given the same total power P of illumination. Consequently, each optical sensor 132 in the sensor stack 148 may, therefore, selectively detect the photon flux of each of the data carriers 112 in the data carrier stack 154. As a result, it may, thus, be possible to acquire information form each of the data carriers 112 with the data carrier stack 154 simultaneously.

[0294] Specifically, in this embodiment or other embodiments of the present invention, the data modules 116 within at least one of the data carriers 112 may be partially transparent, such that a first part of the incident light of the light beam 124 may be transmitted by the data modules 116 and a second part of the incident light beam 124 may be reflected by the data modules 116. In a particular embodiment, the matrix material 120 as comprised by the transparent data carrier 112 differs for at least two of the data carriers 112, preferably for all of the data carriers 112, within the data carrier stack 154. In a preferred example, this distinction is achieved by choosing the matrix material 120 for the respective data carriers 112 in a manner that it is different for each data carrier 112 by one or more properties of the matrix material 120. As a particularly preferred example, the transparent data carriers 112 comprise a different organic fluorescent dye used for dying the respective matrix material 120. As a result, the different colors of the colored data carriers 112 may, thus, be used to distinguish between the data carriers 112.

[0295] A further embodiment is schematically depicted in FIG. 5, in which, alternatively to employing the generated reflected light beams 126, one or more of the transmitted lights beams 160 may be guided to the detector 130, preferably by using a suitably placed mirror 162, via the transfer device 144, such as the lens 146, to the sensor stack 148 of the optical sensors 132. For this purpose, the data carriers 112 may comprise data modules 116 which are adapted of modifying a transmission of the light beam 124 through the data carrier stack 154, irrespective of a fact whether they might exhibit reflective properties or not. In particular, the data modules may appear as an arrangement as black points located within the information layer 118 which may be capable of disturbing the light beam 124 focused to the information layer 118 in a manner that the transmission of the light beam 124 through the data carrier stack 154 may be modified.

[0296] Furthermore, the embodiment as schematically shown in FIG. 4, in which the reflected light beams 126 are guided to the detector 130, may also be combined with the embodiment of FIG. 5, in which the transmitted lights beams 156 are guided to the detector 130. For further details concerning the embodiment as schematically depicted in FIG. 5 reference may be made to the embodiment of FIG. 4.

LIST OF REFERENCE NUMBERS

[0297] 110 data storage system [0298] 112 data carrier [0299] 114 data readout device [0300] 116 data modules [0301] 118 information layer [0302] 120 matrix material [0303] 122 illumination source [0304] 124 light beam [0305] 126 reflected light beam [0306] 128 beam-splitting device [0307] 130 detector [0308] 132 optical sensor [0309] 134 sensor region [0310] 136 evaluation device [0311] 138 actuator [0312] 140 translational and/or rotational relative movement [0313] 142 optical axis [0314] 144 transfer device [0315] 146 lens [0316] 148 sensor stack [0317] 150 interface [0318] 152 front surface [0319] 154 data carrier stack [0320] 156 thin film [0321] 158 transparent adhesive layer [0322] 160 transmitted light beam [0323] 162 mirror