DETECTOR FOR AN OPTICAL DETECTION OF AT LEAST ONE OBJECT

Abstract

A simple and still reliable detector for an accurate determination of a position of at least one object in space is provided. The detector comprises a longitudinal optical sensor (114) having a stack of at least two individual pin diodes (130, 130) arranged between at least two electrodes (132, 132). Upon illumination of the sensor region by an incident light beam (136), a longitudinal sensor signal is generated. The longitudinal sensor signal, given the same power of illumination, is dependent on a beam cross-section of the light beam (136). The at last two individual pin diodes (130, 130) have different spectral sensitivities in order to enable the determination of a distance between the object and the detector by light beams in different spectral ranges, e.g. by light beams in the visible spectral range and in the infrared spectral range.

Claims

1. A detector, suitable for an optical detection of at least one object and comprising: at least one longitudinal optical sensor, the at least one longitudinal optical sensor having at least two individual pin diodes arranged between at least two electrodes, wherein at least one of the at least two individual pin diodes is designated as a sensor region for an incident light beam, wherein the sensor region is designed to generate at least one longitudinal sensor signal in a manner dependent on an illumination of the sensor region by the incident light beam, wherein the at least one longitudinal sensor signal, given the same total power of the illumination, is dependent on a beam cross-section of the incident light beam in the sensor region, and at least one evaluation device, wherein the at least one evaluation device is designed to generate at least one item of information on a longitudinal position of the at least one object by evaluating the at least one longitudinal sensor signal.

2. The detector of claim 1, wherein each of the at least two individual pin diodes comprises an i-type semiconductor layer located between an n-type semiconductor layer and a p-type semiconductor layer, wherein the i-type semiconductor layer of at least one of the at least two individual pin diodes is designated as the sensor region.

3. The detector of claim 2, wherein at least two of the i-type semiconductor layers have different optical properties.

4. The detector of claim 1, wherein each of the at least two individual pin diodes comprises a material selected from the group consisting of: an amorphous silicon (a-Si), an alloy comprising amorphous silicon, a microcrystalline silicon (?c-Si), germanium (Ge), indium antimonide (InSb), indium gallium arsenide (InGaAs), indium arsenide (InAs), gallium nitride (GaN), gallium arsenide (GaAs), aluminum gallium phosphide (AlGaP), cadmium telluride (CdTe), mercury cadmium telluride (HgCdTe), copper indium sulfide (CIS), copper indium gallium selenide (CIGS), copper zinc tin sulfide (CZTS), copper zinc tin selenide (CZTSe), copper-zinc-tin sulfur-selenium chalcogenide (CZTSSe), an organic-inorganic halide perovskite, methylammonium lead iodide (CH3NH3PbI3), a solid solution thereof, and/or and a doped variant thereof.

5. The detector of claim 1, wherein at least one of the at least two individual pin diodes comprises an organic material, wherein the organic material comprises at least one selected from the group consisting of: a dye, a pigment. and a mixture comprising an electron donor material and an electron acceptor material.

6. The detector of claim 5, wherein the organic material comprises a compound selected from the group consisting of: a phthalocvanine, a naphthalocyanine, a subphthalocyanine, a perylene, an anthracene, a pyrene, art oligothiophene, a polythiophene, a fullerene, an indigoid dye, a bis-azo pigment, a squarvlium dye, a thiapyrilium dye, an azulenium dye, a dithioketo-pyrrolopyrrole, a quinacridone, a dibromoanthanthrone, a polyvinylcarbazole, a derivative thereof, and a combination thereof.

7. The detector of claim 6, wherein the electron donor material comprises one of: a poly(3-hexylthiophene-2,5.diyl) (P3HT), a poly[3-(4-noctyl) phenylthiophene] (POPT), a poly[3-10-n-octyl-3-phenothiazine-vinylenethiophene-co-2,5-thiophene] (PTZV-PT), a poly[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b]dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl] thieno[3,4-b]thiophenediyl] (PTB7), a poly{thiophene-2,5-diyl-alt-[5,6-bis(dodecyloxy) benzo[c][1,2,5]thiadiazole]-4,7-diyl} (PBT-T1), a poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b]dithiophene)-alt-4,7(2,1,3-benzothiadiazole)] (PCPDTBT), a poly(5,7-bis(4-decanyl-2-thienyl)-thieno(3,4-b)diathiazolethiophene-2,5) (PDDTT), a poly[N-9-heptadecanyl-2,7-carbazole-alt-5,5-(4,7-di-2-thienyl-2,1,3-benzothiadiazole)] (PCDTBT), a poly[(4,4-bis(2-ethylhexyl)dithieno[3,2-b;2,3-d]silole)-2,6-diyl-alt-(2,1,3-benzothiadazole)-4,7-diyl] (PSBTBT), a poly[3-phenylhydrazonethiophene] (PPHT), a poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV), a poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene-1,2-ethenylene-2,5-dimethoxy-1,4-phenylene-1,2-ethenylene] (M3EH-PPV), a poly[2-methoxy-5-(3,7-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV), a poly[9,9-di-octylfluorene-co-bis-N,N-4-butylphenyl-bis-N,N-phenyl-1,4-phenylenediamine] (PFB), or a derivative, a modification, or a mixture thereof, and wherein the electron acceptor material comprises selected from one of: [6,6]-phenyl-C61-butyric acid methyl ester (PC60BM), [6,6]-Phenyl-C71-butyric acid methyl ester (PC70BM), [6,6]-phenyl C84 butyric acid methyl ester (PC84BM), an indene-C60 bis adduct (ICBA), a diphenylmethanofullerene (DPM) moiety comprising one or two attached oligoether (OE) chains (C70-DPM-OE or C70-DPM-OE2, respectively), a cyano-poly[phenylenevinylene] (CN-PPV), a poly[5-(2-(ethylhexyloxy)-2-methoxycyanoterephthalyliden] (MEH-CN-PPV), a poly[oxa-1,4-phenylene-1,2-(1-cyano)-ethylene-2,5-dioctyloxy-1,4-phenylene-1,2-(2-cyano)-ethylene-1,4-phenylene] (CN-ether-PPV), a poly[1,4-dioctyloxyl-p-2,5-dicyanophenylenevinylene] (DOCN-PPV), a poly[9,9- dioctylfluoreneco-benzothiadiazole] (PF8BT), or a derivative, a modification, or a mixture thereof.

8. The detector of claim 1, further comprising: at least one transversal optical sensor, the at least one transversal optical sensor being adapted to determine a transversal position of the incident light beam traveling from the at least one object to the detector, the transversal position being a position in at least one dimension perpendicular to an optical axis of the detector, the at least one transversal optical sensor being adapted to generate at least one transversal sensor signal, wherein the at least one evaluation device is further designed to generate at least one item of information on a transversal position of the at least one object by evaluating the at least one transversal sensor signal.

9. A camera, wherein the camera is suitable for imaging at least one object and comprises at least one detector according to claim 1.

10. A human-machine interface, wherein the human-machine interface is suitable for exchanging at least one item of information between a user and a machine, wherein the human-machine interface comprises at least one detector of claim 1, wherein the human-machine interface is designed to generate at least one item of geometrical information of the user with the detector, and wherein the human-machine interface is designed to assign at least one item of information to the at least one item of geometrical information.

11. An entertainment device, wherein the entertainment device is suitable for carrying out at least one entertainment function, wherein the entertainment device comprises at least one human-machine interface of claim 10, wherein the entertainment device is designed to enable at least one item of information to be input by a player with the human-machine interface, and wherein the entertainment device is designed to vary the entertainment function in accordance with the at least one item of information.

12. A tracking system, wherein the tracking system is suitable for tracking the position of at least one movable object and comprises: at least one detector of claim 1, and at least one track controller, wherein the at least one track controller is adapted to track a series of positions of the at least one movable object, each position comprising at least one item of information on at least a longitudinal position of the at least one movable object at a specific point in time.

13. A scanning system, wherein the scanning system is suitable for determining at least one position of at least one object and comprises: at least one detector of claim 1, and at least one illumination source adapted to emit at least one light beam configured for an illumination of at least one dot located at at least one surface of the at least one object, wherein the scanning system is designed to generate at least one item of information about a distance between the at least one dot and the scanning system by using the at least one detector.

14. A stereoscopic system comprising at least one tracking system and at least one scanning system, wherein the tracking system is suitable for tracking the position of at least one movable object and comprises: at least one detector of claim 1, and at least one track controller, wherein the at least one track controller is adapted to track a series of positions of the at least one movable object, each position comprising at least one item of information on at least a longitudinal position of the at least one movable object at a specific point in time; wherein the scanning system is suitable for detertnining at least one position of at least one object and comprises: at least one detector of claim 1, and at least one illumination source adapted to emit at least one light beam configured for an illumination of at least one dot located at at least one surface of the at least one object, wherein the scanning system is designed to generate at least one item of information about a distance between the at least one dot and the scanning system by using the at least one detector: and wherein the tracking system and the scanning system each comprise at least one longitudinal optical sensor which are located in a collimated arrangement in a manner such that they are aligned in an orientation parallel to an optical axis of the stereoscopic system and exhibit an individual displacement in an orientation perpendicular to the optical axis of the stereoscopic system.

15. A method for optically detecting at least one object, the method comprising: generating at least one longitudinal sensor signal by using at least one longitudinal optical sensor, wherein the at least one longitudinal optical sensor has at least two individual pin diodes arranged between at least two electrodes, wherein at least one of the at least two individual pin diodes is designated as a sensor region for an incident light beam, wherein the sensor region is designed to generate at least one longitudinal sensor signal in a manner dependent on an illumination of the sensor region by the incident light beam, wherein the at least one longitudinal sensor signal, given the same total power of the illumination, is dependent on a beam cross-section of the incident light beam in the sensor region; and generating at least one item of information on a longitudinal position of the at least one object by evaluating the at least one longitudinal sensor signal of the at least one longitudinal optical sensor.

16. (canceled)

Description

BRIEF DESCRIPTION OF THE FIGURES

[0328] 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 features 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.

[0329] Specifically, in the figures:

[0330] FIG. 1 shows an exemplary embodiment of a detector according to the present invention comprising a longitudinal optical sensor, wherein the longitudinal optical sensor has two individual pin diodes arranged between at least one first electrode and at least one second electrode, wherein at least one of the pin diodes is designed as the sensor region;

[0331] FIG. 2 shows an preferred embodiment of the longitudinal optical sensor having two individual pin diodes arranged between at least one first electrode and at least one second electrode, wherein at least one of the pin diodes is designed as the sensor region;

[0332] FIG. 3 shows experimental results demonstrating the negative FiP effect by using the longitudinal optical sensor according to FIG. 2;

[0333] FIG. 4 shows an exemplary embodiment of an optical detector, a detector system, a human-machine interface, an entertainment device, a tracking system and a camera according to the present invention.

EXEMPLARY EMBODIMENTS

[0334] FIG. 1 illustrates, in a highly schematic fashion, an exemplary embodiment of an optical detector 110 according to the present invention, for determining a position of at least one object 112. The optical detector 110 may preferably be adapted to be used as an infrared detector, particularly for the NIR spectral range. However, other embodiments are feasible.

[0335] The optical detector 110 comprises at least one longitudinal optical sensor 114, which, in this particular embodiment, is arranged along an optical axis 116 of the detector 110. Specifically, the optical axis 116 may be an axis of symmetry and/or rotation of the setup of the optical sensors 114. The optical sensors 114 may be located inside a housing 118 of the detector 110. Further, at least one transfer device 120 may be comprised, preferably a refractive lens 122. An opening 124 in the housing 118, which may, particularly, be located concentrically with regard to the optical axis 116, preferably defines a direction of view 126 of the detector 110. A coordinate system 128 may be defined, in which a direction parallel or antiparallel to the optical axis 116 is defined as a longitudinal direction, whereas directions perpendicular to the optical axis 116 may be defined as transversal directions. In the coordinate system 128, symbolically depicted in FIG. 1, a longitudinal direction is denoted by z and transversal directions are denoted by x and y, respectively. However, other types of coordinate systems 128 are feasible.

[0336] Further, the longitudinal optical sensor 114 has at least two individual pin diodes 130, 130 being arranged, preferably in a stack-like fashion, between at least two electrodes 132, 132. While two individual pin diodes 130, 130 are schematically depicted in FIG. 1, the longitudinal optical sensor 114 may have more than two individual pin diodes 130, 130, such as three, four or more individual pin diodes 130, 130, for special purposes. Thus, the at least two individual pin diodes 130, 130 commonly share the electrodes of the same polarity. As a result, no further electrodes may be arranged between the individual pin diodes 130, 130. If applicable, at least one further pin diode (not depicted here) may be placed on any location between the two electrodes 130, 132. Further, the stack may comprise additional layers, in particular, at least one insulating substrate on which one of the electrodes 130, 132 could be placed. As will be further specified in FIG. 2, a recombination layer 134 may also be located between two adjacent individual pin diodes 130, 130.

[0337] According to the present invention, at least one of the pin diodes 130, 130 is designated as a sensor region for an incident light beam 136. Herein, the longitudinal optical sensor 114 is designed to generate at least one longitudinal sensor signal in a manner dependent on an illumination of a sensor region by the light beam 136. Thus, according to the FiP effect, the longitudinal sensor signal, given the same total power of the illumination, is dependent on a beam cross-section of the light beam 136 in the respective sensor region.

[0338] According to the present invention, all pin diodes 130, 130 within the stack-like arrangement of the longitudinal optical sensor 114 might be employed as the sensor region. However, the pin diodes 130, 130 may, preferably, exhibit different optical properties with respect to each other. As further specified in FIG. 2, the pin diodes 130, 130 could exhibit different optical sensitivities, in particular different external quantum efficiencies, with respect to different wavelength ranges of the incident light beam 136. Further, the pin diodes 130, 130 could exhibit different types of the FiP effect, i.e. they could produce different longitudinal sensor signals depending on the illumination of the sensor region by the incident light beam 136, whereby each of the pin diodes 130, 130 may show the positive FiP effect, the negative FiP, or no FiP effect at all as long as one of the pin diodes 130, 130 actually exhibits the FiP effect, irrespective whether it may be the positive FiP effect or the negative FiP effect. Alternatively or in addition, other kinds of differences between the pin diodes 130, 130 in the longitudinal optical sensor 114 may also be feasible.

[0339] Via a longitudinal signal lead 138, the longitudinal sensor signal may be transmitted to an evaluation device 140, which will be explained in further detail below.

[0340] In a preferred embodiment, one of the pin diodes 130, 130 may be located at a focal point 142 of the transfer device 120. Additionally or alternatively, in particular in embodiment in which the optical detector 110 may not comprise a transfer device 120, the longitudinal optical sensor 114 may be arranged in a movable fashion along the optical axis 116, such as by means of an actuator 144, which may be controllable by using an actuator control unit 146, which may be placed within the evaluation device 140. However, other kinds of setups may be feasible.

[0341] The evaluation device 140 is, generally, designed to generate at least one item of information on a position of the object 112 by evaluating the sensor signal of the transversal optical sensor 114. For this purpose, the evaluation device 140 may comprise one or more electronic devices and/or one or more software components, in order to evaluate the sensor signals, which are symbolically denoted by a longitudinal evaluation unit 148 (denoted by z). As will be explained below in more detail, the evaluation device 140 may be adapted to determine the at least one item of information on the longitudinal position of the object 112 by comparing more than one longitudinal sensor signals of the longitudinal optical sensor 114.

[0342] As explained above, the longitudinal sensor signal as provided by the longitudinal optical sensor 114 upon impingement by the light beam 136 depends on an electrically detectable property of a material in the sensor region. In order to determine a variation of the electrically detectable property of the material in the sensor region it may, as schematically depicted in FIG. 1, therefore be advantageous to measure a current, which may also be denominated a photocurrent, through the longitudinal optical sensor 114.

[0343] The light beam 136 for illumining the sensor region of the longitudinal optical sensor 114 may be generated by a light-emitting object 112. Alternatively or in addition, the light beam 136 may be generated by a separate illumination source 150, which may include an ambient light source and/or an artificial light source, such as a light-emitting diode 152, being adapted to illuminate the object 112 that the object 112 may be able to reflect at least a part of the light generated by the illumination source 150 in a manner that the light beam 136 may be configured to reach the sensor region of the longitudinal optical sensor 114, preferably by entering the housing 118 of the optical detector 110 through the opening 124 along the optical axis 116.

[0344] In a specific embodiment, the illumination source 150 may be a modulated light source 154, wherein one or more modulation properties of the illumination source 150 may be controlled by at least one optional modulation device 156. Alternatively or in addition, the modulation may be effected in a beam path between the illumination source 150 and the object 112 and/or between the object 112 and the longitudinal optical sensor 114. Further possibilities may be conceivable. In this specific embodiment, it may be advantageous taking into account one or more of the modulation properties, in particular the modulation frequency, when evaluating the sensor signal of the transversal optical sensor 114 for determining the at least one item of information on the position of the object 112.

[0345] Generally, the evaluation device 140 may be part of a data processing device 158 and/or may comprise one or more data processing devices 158. The evaluation device 140 may be fully or partially integrated into the housing 118 and/or may fully or partially be embodied as a separate device which is electrically connected in a wireless or wire-bound fashion to the longitudinal optical sensor 114. The evaluation device 140 may further comprise one or more additional components, such as one or more electronic hardware components and/or one or more software components, such as one or more measurement units and/or one or more evaluation units and/or one or more controlling units (not depicted here).

[0346] FIG. 2 shows a preferred embodiment of the longitudinal optical sensor 114. In accordance with the embodiment as shown in FIG. 1, the longitudinal optical sensor 114 comprises the individual pin diodes 130, 130 which are arranged in the stack-like fashion between the two electrodes 132, 132. However, arrangements with more than two individual pin diodes 130, 130, such as three or four individual pin diodes 130, 130, may also be feasible. As further schematically depicted in FIG. 2, the electrode 132 is located adjacently to as at least partially optically transparent substrate 160, in particular a transparent, a semi-transparent or a translucent substrate, which may, preferably, comprise a material selected from glass, quartz, or a suitable organic polymer. Consequently, the incident light beam 136 impinging the longitudinal optical sensor 114 can travel through the substrate 160 before it may reach the electrode 130.

[0347] Further, for facilitating the light beam 136 to arrive at the pin diodes 130, 130 the electrode 130 located within the beam path 162 of the incident light beam 136, which may also be denominated as a front electrode, is, in this particular embodiment, selected to be at least partially optically transparent, in particular, to exhibit transparent, semi-transparent or translucent properties. For this purpose, the at least partially optically transparent electrode 130 may, preferably, comprise at least one transparent conductive oxide (TCO), in particular at least one of indium-doped tin oxide (ITO), fluorine-doped tin oxide (FTO), zinc oxide (ZnO), aluminum-doped zinc oxide (AZO), a perovskite TCO, such as SrVO3, or CaVO3, or, alternatively, metal nanowires, in particular Ag or Cu nanowires. However, other kinds of optically transparent materials which may be suited as electrode material may also be applicable for the electrode 130.

[0348] The electrode 132 may also be accomplished in a similar manner as the electrode 132, i.e.

[0349] exhibiting at least partially optically transparent properties. However, since the electrode 132 may be located outside the beam path 162 of the light beam 136 within the longitudinal optical sensor 114, it may, alternatively or in addition, be accomplished in an optically intransparent manner and, thus, also be denominated as a back electrode. Herein, the at least one optically intransparent electrode 132 may, preferably, comprise a metal electrode, in particular one or more of a silver (Ag) electrode, a platinum (Pt) electrode, an aluminum (Al) electrode, or a gold (Au) electrode, or, alternatively, a graphene electrode. Preferably, the optically intransparent electrode 132 may comprise a uniform metal layer. Alternatively, the optically intransparent electrode may be a split electrode being arranged as a number of partial electrodes or in form of a metallic grid.

[0350] In the preferred embodiment of FIG. 2, the two individual pin diodes 130, 130 of the longitudinal optical sensor 114 may, preferably, exhibit a similar internal structure. Accordingly, the pin diode 130 comprises an i-type semiconductor layer 164, which is located between an n-type semiconductor layer 166 and a p-type semiconductor layer 168. Similarly, the pin diode 130 comprises an i-type semiconductor layer 170, which is located between an n-type semiconductor layer 172 and a p-type semiconductor layer 174. As usually, while charge carriers in the n-type semiconducting layers 166, 172 are predominantly provided by electrons, the charge carriers in the p-type semiconducting layers 168, 174 are predominantly provided by holes. In contrast hereto, the i-type semiconducting layers 164, 170 may be considered as undoped intrinsic semiconductor regions. As schematically depicted in FIG. 2, the n-type semiconductor layer 166 adjoins the electrode 132 while the p-type semiconductor layer 174 adjoins the electrode 130. However, other kinds of arrangements are possible, in particular, where both the n-type semiconductor layer 166 and the p-type semiconductor layer 168 as well as the n-type semiconductor layer 172 and the p-type semiconductor layer 174 change their locations. Further, in the preferred embodiment of FIG. 2, the i-type semiconductor layers 164, 170 may, preferably, exhibit a thickness exceeding the thickness of both the n-type semiconductor layers 166, 172 and the p-type semiconductor layers 168, 174. As a result, a depletion region which may exist within the i-type semiconductor layers 164, 170 may assume a large volume, thus, allowing a large number of electron-hole pairs to be generated by incident photons as comprised in the light beam 136.

[0351] Preferably, the pin diodes 130, 130 of the longitudinal optical sensor 114 may comprise a kind of amorphous silicon which is, generally, known to exhibit a non-linear frequency response. As a result which will be shown in FIG. 3, the FiP effect may be observable in the longitudinal optical sensor 114 equipped with this kind of pin diodes 130, 130. According to the present invention, the two individual pin diodes 130, 130 as comprised within the longitudinal optical sensor 114 may exhibit different optical sensitivities, in particular different external quantum efficiencies, with respect to different wavelength ranges of the incident light beam 136. For this purpose, two different kinds of materials may be used for the two individual pin diodes 130, 130.

[0352] Firstly, the i-type semiconducting layer 164 of the pin diode 130 may, thus, comprise undoped intrinsic amorphous silicon 176 (a-Si), preferably in a form of hydrogenated amorphous silicon 178 (a-Si:H), wherein, in the a-Si:H, the amorphous silicon is passivated by using hydrogen in a manner that a number of dangling bonds within the untreated amorphous silicon may be reduced by several orders of magnitude. Thus, the a-Si:H may comprise a low amount of defects, which makes it particular suitable for optical devices, such as for the longitudinal optical sensor 114 according to the present invention. As already mentioned above, the external quantum efficiency of the i-type semiconducting layer 164 of the pin diode 130 which comprises the undoped a-Si, preferably the undoped a-Si:H, exhibits a large value within the spectral range from 380 nm to 700 nm, i.e. within most parts of the visual spectrum. Thus, as long as the incident light beam 136 may have a wavelength within this spectral range from 380 nm to 700 nm, the pin diode 130, in particular the i-type semiconducting layer 164 of the pin diode 130 may be designated as the sensor region for an incident light beam 136.

[0353] However, the present invention allows more, i.e. that the i-type semiconducting layer 164 of the pin diode 130 comprising the undoped a-Si, preferably the undoped a-Si:H, may still be used for incident lights beams which may exhibit a wavelength outside the spectral range from 380 nm to 700 nm. In this particularly preferred event, the pin diode 130 may, however, not be used as the sensor region in the manner as described above but it may, nevertheless, work as a trap-holding semiconductor 180. Consequently, the pin diode 130 may, thus, allow receiving positive charge carriers that may be generated in the pin diode 130 by the incident light beam 136, wherein the pin diode 130 may exhibit sufficient external quantum efficiency within the desired wavelength range, in particular, in at least a partition of the NIR spectral range, preferably, from 760 nm to 1400 nm.

[0354] Thus, the pin diode 130 may exhibit the similar arrangement as the pin diode 130, wherein the pin diode 130 may comprise one of: a microcrystalline silicon 182 (?c-Si), preferably a hydrogenated microcrystalline silicon 184 (?c-Si:H). Again, in the ?c-Si:H, the microcrystalline silicon is passivated by using hydrogen in a manner that a number of dangling bonds within the untreated microcrystalline silicon may be reduced by several orders of magnitude. Thus, also the ?c-Si:H may comprise a low amount of defects, which makes it particular suitable for optical devices, such as the for longitudinal optical sensor 114 according to the present invention. Alternatively, an amorphous alloy of germanium and silicon (a-GeSi), preferably a hydrogenated amorphous germanium silicon alloy (a-GeSi:H), may be used.

[0355] Since the pin diode 130 comprising pc-Si:H has a non-negligible quantum efficiency within the NIR region over a wavelength range approximately from 500 nm to 1100 nm, the pin diode 130 may, thus, be designated as the sensor region 186 for an incident light beam 136 having a wavelength in the range approximately from 500 nm to 1100 nm. According to the present invention, the sensor region 186 in the pin diode 130 is illuminated by the incident light beam 136. Given the same total power of the illumination, a longitudinal sensor signal as generated in the longitudinal optical sensor 114, therefore, depends on a beam cross-section 188 of the light beam 136 in the sensor region 186, also be denominated as a spot size. Herein, the longitudinal sensor signal may, preferably, be determined by applying an electrical signal, such as a voltage signal and/or a current signal. As a result, the longitudinal optical sensor 114, thus, principally allows determining the beam cross-section of the light beam 136 in the sensor region 186 from a recording of the longitudinal sensor signal.

[0356] As already mentioned above, the recombination layer 134 may be located between two adjacent individual pin diodes 130, 130, in particular between the p-type semiconductor layer 168 of the pin diode 130 and the n-type semiconductor layer 172 of the pin diode 130. Herein, the recombination layer 134 may, particularly, be introduced in order to provide a sufficient Ohmic contact between the two adjacent individual pin diodes 130, 130 in a manner that as many holes as possible from one junction may be joined with as many electrons from the other junction. Thus, the recombination layer may, preferably, be transparent and exhibit a high resistivity in transversal direction in order to accomplish avoiding a distribution of charge charriers over the whole detector plane.

[0357] The embodiment according to FIG. 2 exhibits a comparatively simple and cost-efficient setup of the longitudinal optical sensor 114, in particular, for use within the NIR spectral range. However, other embodiments not depicted here may also be appropriate as the setup for the longitudinal optical sensor 114 according to the present invention. By way of example, the pin diode 130 may, alternatively, comprise an amorphous alloy of silicon and carbon (a-SiC) or, preferably, a hydrogenated amorphous silicon carbon alloy (a-SiC:H), which exhibit a high external quantum efficiency within the UV wavelength range, preferably, over the complete UVA and UVB wavelength range from 280 nm to 400 nm. Moreover, other kinds of combinations applicable to the pin diodes 130, 130 may also be feasible.

[0358] Further, the individual pin diodes 130, 130 could exhibit different types of the FiP effect, i.e. different longitudinal sensor signals that may depend on the illumination of the sensor region 186 by the incident light beam 136. Herein, any or both of the pin diodes 130, 130 can show the positive FiP effect, the negative FiP, or no FiP effect at all as long as at least one of the pin diodes 130, 130 actually exhibits the FiP effect, irrespective whether it may be the positive FiP effect or the negative FiP effect. Alternatively or in addition, other kinds of differences between the pin diodes 130, 130 as comprised in the longitudinal optical sensor 114 may also be feasible.

[0359] In FIG. 3, the occurrence of the above-mentioned negative FiP effect in the exemplary embodiments of FIGS. 1 and 2 is experimentally demonstrated. Herein, FIG. 3 shows so- called FiP curves 190 as the experimental results in the setup of the longitudinal optical sensor 114 according to FIG. 2, wherein the pin diode 130 comprises a-Si:H as the trap-holding semiconductor 180 and the pin diode 130 comprises pc-Si:H which constitutes the sensor region 186. Herein, the setup of the optical detector 110 comprised a light-emitting diode (LED) 152 which was placed 80 cm in front of the refractive lens 122 and which was employed as the illumination source 150 for generating the light beam 136 with an optical wavelength of 850 nm which was adapted for illuminating the object 112 in the NIR spectral range.

[0360] During the experiment, the longitudinal optical sensor 114 was moved along the z-axis of the optical detector 110 by using the actuator 144 and the resulting photocurrent I in pA was measured. Herein, the focal point 142 of the refractive lens 122 was located at a distanced of about 32 mm from the refractive lens 122, whereby the refractive lens 122 and the light-emitting diode 152 serving as the illumination source 150 were placed at larger z-values. Moving the sensor along the z-axis of the optical detector 110 during the experiment resulted in a variation of the beam cross-section (spot size) 188 of the incident light beam 136 at the position of the sensor region 186, thus yielding a z-dependent photocurrent signal which can here viewed as the longitudinal sensor signal.

[0361] As illustrated in FIG. 3, the photocurrent of the longitudinal optical sensor 114 has been measured under four different kinds of experimental conditions. Herein, the sensor region 186 was either illuminated from a frontside 192 or from a backside 194 of the setup. Herein, the term frontside 192 indicates that the sensor region 186 was illuminated by the beam path 162 in the manner as schematically illustrated in FIG. 2. As a result, the incident light beam 136 first traveled through the pin diode 130 acting as the trap-holding semiconductor 180 before it reached the sensor region 186 in the pin diode 130. In contrast hereto, the term backside 192 indicates that the sensor region 186 was illuminated by a different beam path (not depicted here) by which the incident light beam 136 first traveled through the sensor region 186 in the pin diode 130 before it reached the trap-holding semiconductor 180 within the pin diode 130.

[0362] Herein, in the case in which the sensor region 186 is illuminated from the backside 194 the electrode 132, which may also be denominated as the back electrode, is accomplished as an at least partially transparent electrode as described above in more detail whereas in the case in which the sensor region 186 is illuminated from the frontside 192 the optical properties of the electrode 132 may be at least partially transparent or intransparent. Consequently, it may, additionally, be distinguished between a first setup in which the respective FiP curve 190 is recorded by using a backlight 196 as generated by the reflecting intransparent electrode 132 or without backlight 198 in case the electrode 132 exhibits at least partially transparent optical properties. In a similar manner, in the case of illuminating the sensor region 186 from the backside 194, the electrode 132, which may also be denominated as the front electrode, may also exhibit at least partially transparent or intransparent optical properties, thus, allowing a recording of the FiP curves 190 by using the backlight 196 or without backlight 198.

[0363] As illustrated in FIG. 3, the FiP curves 190 comprising the observable photocurrent which may be attributed as the longitudinal sensor signal varied with the varying distance of the longitudinal optical sensor 114 from the object 112 and comprises a distinct minimum in an event in which the object 112 was focused on the longitudinal optical sensor 114. Thus, the optical detector 110 according to the present invention may be arranged in a manner that it clearly exhibits the above-described negative FiP effect, i.e. the observation of a minimum of the longitudinal sensor signal under a condition in which the sensor region 130 is impinged by the light beam 136 with the smallest possible cross-section, which occurs in this setup when the sensor region 186 is located at the focal point 142 as effected by the refractive lens 122, i.e. here at a distance of approximately 32 mm from the refractive lens 122.

[0364] As an example, FIG. 4 shows an exemplary embodiment of a detector system 200, comprising at least one optical detector 110, such as the optical detector 110 as disclosed in one or more of the embodiments shown in FIG. 1 or 2. Herein, the optical detector 110 may be employed as a camera 202, specifically for 3D imaging, which may be made for acquiring images and/or image sequences, such as digital video clips. Further, FIG. 4 shows an exemplary embodiment of a human-machine interface 204, which comprises the at least one detector 110 and/or the at least one detector system 200, and, further, an exemplary embodiment of an entertainment device 206 comprising the human-machine interface 204. FIG. 4 further shows an embodiment of a tracking system 208 adapted for tracking a position of at least one object 112, which comprises the detector 110 and/or the detector system 200.

[0365] With regard to the optical detector 110 and to the detector system 200, reference may be made to the full disclosure of this application. Basically, all potential embodiments of the detector 110 may also be embodied in the embodiment shown in FIG. 4. The evaluation device 140 may be connected to each of the at least two longitudinal optical sensors 114, in particular, by the signal leads 138. By way of example, the signal leads 138 may be provided and/or one or more interfaces, which may be wireless interfaces and/or wire-bound interfaces. Further, the signal leads 138 may comprise one or more drivers and/or one or more measurement devices for generating sensor signals and/or for modifying sensor signals.

[0366] As described above, the optical detector 110 may comprise a single longitudinal optical sensor 114 or, as e.g. disclosed in WO 2014/097181 A1, a stack of longitudinal optical sensors 114, particularly in combination with one or more transversal optical sensors 209. As an example, one or more at least partially transparent transversal optical sensors 209 may be located on a side of the stack of longitudinal optical sensors 114 facing towards the object 112. Alternatively or additionally, one or more transversal optical sensors 209 may be located on a side of the stack of longitudinal optical sensors 114 facing away from the object 112. In this case the last of the transversal optical sensors 209 may be intransparent. Thus, in a case in which determining the x- and/or y-coordinate of the object in addition to the z-coordinate may be desired, it may be advantageous to employ, in addition to the at one longitudinal optical sensor 114 at least one transversal optical sensor 209 which may provide at least one transversal sensor signal. For potential embodiments of the transversal optical sensor, reference may be made to WO 2014/097181 A1. As described therein, a use of two or, preferably, three longitudinal optical sensors 114 may support the evaluation of the longitudinal sensor signals without any remaining ambiguity. However, embodiments which may only comprise a single longitudinal optical 114 sensor but no transversal optical sensor 209 may still be possible, such as in a case wherein only determining the depth, i.e. the z-coordinate, of the object may be desired. The at least one optional transversal optical sensor 209 may further be connected to the evaluation device 140, in particular, by the signal leads 138.

[0367] Further, the at least one transfer device 120 may be provided, in particular as the refractive lens 122 or convex mirror. The optical detector 110 may further comprise the at least one housing 118 which, as an example, may encase one or more of components 114, 209.

[0368] Further, the evaluation device 140 may fully or partially be integrated into the optical sensors 114, 209 and/or into other components of the optical detector 110. The evaluation device 140 may also be enclosed into housing 118 and/or into a separate housing. The evaluation device 140 may comprise one or more electronic devices and/or one or more software components, in order to evaluate the sensor signals, which are symbolically denoted by the longitudinal evaluation unit 148 (denoted by z) and a transversal evaluation unit 210 (denoted by xy) and. By combining results derived by these evolution units 154, 156, a position information 212, preferably a three-dimensional position information, may be generated (denoted by x, y, z).

[0369] Further, the optical detector 110 and/or to the detector system 200 may comprise an imaging device 214 which may be configured in various ways. Thus, as depicted in FIG. 4, the imaging device 214 can for example be part of the detector 110 within the detector housing 118. Herein, the imaging device signal may be transmitted by one or more imaging device signal leads 138 to the evaluation device 140 of the detector 110. Alternatively, the imaging device 214 may be separately located outside the detector housing 118. The imaging device 214 may be fully or partially transparent or intransparent. The imaging device 214 may be or may comprise an organic imaging device or an inorganic imaging device. Preferably, the imaging device 214 may comprise at least one matrix of pixels, wherein the matrix of pixels may particularly be selected from the group consisting of: an inorganic semiconductor sensor device such as a CCD chip and/or a CMOS chip; an organic semiconductor sensor device.

[0370] In the exemplary embodiment as shown in FIG. 4, the object 112 to be detected, as an example, may be designed as an article of sports equipment and/or may form a control element 216, the position and/or orientation of which may be manipulated by a user 218. Thus, generally, in the embodiment shown in FIG. 4 or in any other embodiment of the detector system 200, the human-machine interface 204, the entertainment device 206 or the tracking system 208, the object 112 itself may be part of the named devices and, specifically, may comprise the at least one control element 216, specifically, wherein the at least one control element 216 has one or more beacon devices 220, wherein a position and/or orientation of the control element 216 preferably may be manipulated by user 218. As an example, the object 112 may be or may comprise one or more of a bat, a racket, a club or any other article of sports equipment and/or fake sports equipment. Other types of objects 112 are possible. Further, the user 218 may be considered as the object 112, the position of which shall be detected. As an example, the user 218 may carry one or more of the beacon devices 220 attached directly or indirectly to his or her body.

[0371] The optical detector 110 may be adapted to determine at least one item on a longitudinal position of one or more of the beacon devices 220 and, optionally, at least one item of information regarding a transversal position thereof, and/or at least one other item of information regarding the longitudinal position of the object 112 and, optionally, at least one item of information regarding a transversal position of the object 112. Particularly, the optical detector 110 may be adapted for identifying colors and/or for imaging the object 112, such as different colors of the object 112, more particularly, the color of the beacon devices 220 which might comprise different colors. The opening 124 in the housing 118, which, preferably, may be located concentrically with regard to the optical axis 116 of the detector 110, may preferably define a direction of a view 126 of the optical detector 110.

[0372] The optical detector 110 may be adapted for determining the position of the at least one object 112. Additionally, the optical detector 110, specifically an embodiment including the camera 202, may be adapted for acquiring at least one image of the object 112, preferably a 3D-image. As outlined above, the determination of a position of the object 112 and/or a part thereof by using the optical detector 110 and/or the detector system 200 may be used for providing a human-machine interface 204, in order to provide at least one item of information to a machine 222. In the embodiments schematically depicted in FIG. 4, the machine 222 may be or may comprise at least one computer and/or a computer system comprising the data processing device 158. Other embodiments are feasible. The evaluation device 140 may be a computer and/or may comprise a computer and/or may fully or partially be embodied as a separate device and/or may fully or partially be integrated into the machine 222, particularly the computer. The same holds true for a track controller 224 of the tracking system 208, which may fully or partially form a part of the evaluation device 140 and/or the machine 222.

[0373] Similarly, as outlined above, the human-machine interface 204 may form part of the entertainment device 206. Thus, by means of the user 218 functioning as the object 112 and/or by means of the user 218 handling the object 112 and/or the control element 216 functioning as the object 112, the user 218 may input at least one item of information, such as at least one control command, into the machine 222, particularly the computer, thereby varying the entertainment function, such as controlling the course of a computer game.

LIST OF REFERENCE NUMBERS

[0374] 110 detector

[0375] 112 object

[0376] 114 longitudinal optical sensor

[0377] 116 optical axis

[0378] 118 housing

[0379] 120 transfer device

[0380] 122 refractive lens

[0381] 124 opening

[0382] 126 direction of view

[0383] 128 coordinate system

[0384] 130, 130 pin diode

[0385] 132, 132 electrode

[0386] 134 recombination layer

[0387] 136 light beam

[0388] 138 signal leads

[0389] 140 evaluation device

[0390] 142 focal point

[0391] 144 actuator

[0392] 146 actuator control unit

[0393] 148 longitudinal evaluation unit

[0394] 150 illumination source

[0395] 152 light-emitting diode

[0396] 154 modulated illumination source

[0397] 156 modulation device

[0398] 158 data processing device

[0399] 160 substrate

[0400] 162 beam path

[0401] 164 i-type semiconductor layer

[0402] 166 n-type semiconductor layer

[0403] 168 p-type semiconductor layer

[0404] 170 i-type semiconductor layer

[0405] 172 n-type semiconductor layer

[0406] 174 p-type semiconductor layer

[0407] 176 amorphous silicon (a-Si)

[0408] 178 hydrogenated amorphous silicon (a-Si:H)

[0409] 180 trap-holding semiconductor

[0410] 182 microcrystalline silicon 178 (?c-Si)

[0411] 184 hydrogenated microcrystalline silicon 178 (?c-Si:H)

[0412] 186 sensor region

[0413] 188 beam cross-section (spot size)

[0414] 190 FiP curve

[0415] 192 frontside

[0416] 194 backside

[0417] 196 with backlight

[0418] 198 without backlight

[0419] 200 detector system

[0420] 202 camera

[0421] 204 human-machine interface

[0422] 206 entertainment device

[0423] 208 tracking system

[0424] 209 transversal optical sensor

[0425] 210 transversal evaluation unit

[0426] 212 position information

[0427] 214 imaging device

[0428] 216 control element

[0429] 218 user

[0430] 220 beacon device

[0431] 222 machine

[0432] 224 track controller