Detector for determining a position of at least one object

Abstract

A detector (110) for determining a position of at least one object (112), the detector (110) comprising: at least one transfer device (114) for imaging the object (112) into an image plane (116), the transfer device (114) having a focal plane (118), at least one longitudinal optical sensor (122), wherein the longitudinal optical sensor (122) has at least one sensor region (124), wherein the longitudinal optical sensor (122) is at least partially transparent, wherein the longitudinal optical sensor (122) is designed to generate at least one longitudinal sensor signal in a manner dependent on an illumination of sensor region (124) by at least one light beam propagating from the object to the detector (110), wherein the longitudinal sensor signal, given the same total power of the illumination, is dependent on a beam cross-section of the light beam in the sensor region (124); and at least one evaluation device (129), wherein the evaluation device (129) is designed to generate at least one item of information on a longitudinal position of the object (112) by evaluating the longitudinal sensor signal. Herein the at least one longitudinal optical sensor (122) comprises a focal longitudinal optical sensor (136), wherein the focal longitudinal optical sensor (136) at least substantially is arranged in the focal plane (118).

Claims

1. A detector for determining a position of at least one object, the detector comprising: at least one transfer device for imaging the object into an image plane, the transfer device having a focal plane, at least one longitudinal optical sensor, wherein the longitudinal optical sensor has at least one sensor region, wherein the longitudinal optical sensor is at least partially transparent, wherein the longitudinal optical sensor is designed to generate at least one longitudinal sensor signal in a manner dependent on an illumination of the sensor region by at least one light beam propagating from the object to the detector, wherein the longitudinal sensor signal, given the same total power of the illumination, is dependent on a beam cross-section of the light beam in the sensor region; and at least one evaluation device, wherein the evaluation device is designed to generate at least one item of information on a longitudinal position of the object by evaluating the longitudinal sensor signal, wherein the at least one longitudinal optical sensor comprises a focal longitudinal optical sensor, wherein the focal longitudinal optical sensor at least substantially is arranged in the focal plane, and wherein the focal longitudinal optical sensor is spaced apart from the focal plane by a distance ±ε, wherein |ε|≤0.2.Math.f, with f being the focal length of the transfer device.

2. The detector according to claim 1, wherein the evaluation device is adapted to evaluate at least one longitudinal sensor signal j.sub.focal of the focal longitudinal optical sensor and to derive a theoretical longitudinal sensor signal j.sub.image of a hypothetical longitudinal optical sensor in the image plane.

3. The detector according to claim 2, wherein the evaluation device is adapted to use, for determining the theoretical longitudinal sensor signal j.sub.image, a predetermined or determinable relationship between the longitudinal sensor signal j.sub.focal of the focal longitudinal optical sensor and the theoretical longitudinal sensor signal j.sub.image.

4. The detector according to claim 2, wherein the evaluation device is adapted to use, for determining the theoretical longitudinal sensor signal j.sub.image, an assumption that the theoretical longitudinal sensor signal j.sub.image is proportional to the longitudinal sensor signal j.sub.focal of the focal longitudinal optical sensor.

5. The detector according to claim 4, wherein the evaluation device, for determining the theoretical longitudinal sensor signal j.sub.image, is adapted to use the following relationship: $\frac{j_{image}}{j_{focal}} = const .,$ with const. being a predetermined or determinable constant.

6. The detector according to claim 4, wherein the evaluation device, for determining the theoretical longitudinal sensor signal j.sub.image, is adapted to use the following relationship: $\frac{j_{image}}{j_{focal}} = c (h_{target}, f_{lens}, l_{lens}),$ with c(h.sub.target, f.sub.lens, l.sub.lens) being a predetermined or determinable function dependent on the size h.sub.target of the object, the focal length f.sub.lens of the transfer device, and the aperture l.sub.lens of the transfer device.

7. The detector according to claim 1, wherein the at least one longitudinal optical sensor, besides the focal longitudinal optical sensor, comprises at least one further longitudinal optical sensor.

8. The detector according to claim 7, wherein the at least one longitudinal optical sensor comprises a stack of longitudinal optical sensors.

9. The detector according to claim 8, wherein the focal longitudinal optical sensor forms part of the stack of longitudinal optical sensors.

10. The detector according to claim 8, wherein the stack of longitudinal optical sensors comprises no more than three longitudinal optical sensors.

11. The detector according to claim 1, wherein the at least one longitudinal optical sensor comprises at least one semiconductor detector, wherein the semiconductor detector is an organic semiconductor detector comprising at least one organic material.

12. The detector according to claim 11, wherein the semiconductor detector is at least one member selected from the group consisting of an organic solar cell, a dye solar cell, a dye-sensitized solar cell, a solid dye solar cell, and a solid dye-sensitized solar cell.

13. The detector according to claim 1, wherein the at least one longitudinal optical sensor comprises at least one first electrode, at least one n-semiconducting metal oxide, at least one dye, at least one p-semiconducting organic material, and at least one second electrode.

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

15. An entertainment device for carrying out at least one entertainment function, wherein the entertainment device comprises at least one human-machine interface according to claim 14, 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, wherein the entertainment device is designed to vary the entertainment function in accordance with the information.

16. A tracking system for tracking a position of at least one movable object, the tracking system comprising a detector according to claim 1, the tracking system further comprising at least one track controller, wherein the track controller (158) is adapted to track a series of positions of the object at specific points in time.

17. A camera for imaging at least one object, the camera comprising at least one detector according to claim 1.

18. A method for determining a position of at least one object, the method comprising: imaging the object into an image plane by using at least one transfer device, the transfer device having a focal plane, providing at least one longitudinal optical sensor, wherein the longitudinal optical sensor has at least one sensor region, wherein the longitudinal optical sensor is at least partially transparent, and generating at least one longitudinal sensor signal by using the at least one longitudinal optical sensor, wherein the at least one longitudinal sensor signal is dependent on an illumination of the sensor region by at least one light beam propagating from the object to the longitudinal optical sensor, wherein the longitudinal sensor signal, given the same total power of the illumination, is dependent on a beam cross-section of the light beam in the sensor region, and generating at least one item of information on a longitudinal position of the object by evaluating the longitudinal sensor signal, wherein the at least one longitudinal optical sensor comprises a focal longitudinal optical sensor, wherein the focal longitudinal optical sensor at least substantially is arranged in the focal plane, and wherein the focal longitudinal optical sensor is spaced apart from the focal plane by a distance ±ε, wherein |ε|≤0.2.Math.f, with f being the focal length of the transfer device.

19. The method according to claim 18, wherein said imaging is carried out with a detector, the detector comprising: at least one transfer device for imaging the object into an image plane, the transfer device having a focal plane, at least one longitudinal optical sensor, wherein the longitudinal optical sensor has at least one sensor region, wherein the longitudinal optical sensor is at least partially transparent, wherein the longitudinal optical sensor is designed to generate at least one longitudinal sensor signal in a manner dependent on an illumination of the sensor region by at least one light beam propagating from the object to the detector, wherein the longitudinal sensor signal, given the same total power of the illumination, is dependent on a beam cross-section of the light beam in the sensor region; and at least one evaluation device, wherein the evaluation device is designed to generate at least one item of information on a longitudinal position of the object by evaluating the longitudinal sensor signal, wherein the at least one longitudinal optical sensor comprises a focal longitudinal optical sensor, wherein the focal longitudinal optical sensor at least substantially is arranged in the focal plane.

20. The method according to claim 18, the method further comprising evaluating at least one longitudinal sensor signal j.sub.focal of the focal longitudinal optical sensor and to derive a theoretical longitudinal sensor signal j.sub.image of a hypothetical longitudinal optical sensor in the image plane.

21. The method according to claim 20, wherein, for determining the theoretical longitudinal sensor signal j.sub.image, a predetermined or determinable relationship between the longitudinal sensor signal j.sub.focal of the focal longitudinal optical sensor and the theoretical longitudinal sensor signal j.sub.image is used.

22. The method according to claim 20, wherein, for determining the theoretical longitudinal sensor signal j.sub.image, an assumption that the theoretical longitudinal sensor signal j.sub.image is proportional to the longitudinal sensor signal j.sub.focal of the focal longitudinal optical sensor (136) is used.

23. The method according to claim 22, wherein, for determining the theoretical longitudinal sensor signal j.sub.image, the following relationship is used: $\frac{j_{image}}{j_{focal}} = const .,$ with const. being a predetermined or determinable constant.

24. The method according to claim 22, wherein, for determining the theoretical longitudinal sensor signal j.sub.image, the following relationship is used: $\frac{j_{image}}{j_{focal}} = c (h_{target}, f_{lens}, l_{lens}),$ with c(h.sub.target, f.sub.lens, l.sub.lens) being a predetermined or determinable function dependent on the size h.sub.target of the object, the focal length f.sub.lens of the transfer device, and the aperture l.sub.lens of the transfer device.

25. The method according to claim 18, wherein the at least one longitudinal optical sensor, besides the focal longitudinal optical sensor, comprises at least one further longitudinal optical sensor.

26. The method according to claim 25, wherein the at least one longitudinal optical sensor comprises a stack of longitudinal optical sensors.

27. The method according to claim 26, wherein the focal longitudinal optical sensor forms part of the stack of longitudinal optical sensors.

28. The method according to claim 26, wherein the stack of longitudinal optical sensors comprises no more than three longitudinal optical sensors.

29. A method of determining a longitudinal position of an object in a field, the method comprising detecting the longitudinal position of the object with a detector according to claim 1, wherein the field is at least one of a position measurement in traffic technology; an entertainment application; a security application; a safety application; a human-machine interface application; a tracking application; a photography application; an imaging application or camera application; a mapping application for generating maps of at least one space; a use in combination with at least one time-of-flight measurement; a positioning system; and a communication system.

30. The human-machine interface of claim 14, wherein the human-machine interface is designed to assign to the geometrical information at least one control command.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) 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 in any reasonable 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.

(2) In the figures:

(3) FIG. 1 A shows an exemplary embodiment of a detector according to the present invention;

(4) FIG. 1 B shows an exemplary embodiment of the detector according to the present invention;

(5) FIG. 2 A shows longitudinal sensor signal curves for different focus positions;

(6) FIG. 2 B shows longitudinal sensor signal curves for different focus positions normalized to a corresponding longitudinal sensor signal of the focal longitudinal optical sensor;

(7) FIG. 2 C shows a magnification of an intersection range of FIG. 2B; and

(8) FIG. 3 shows an exemplary embodiment of the detector used in a human-machine interface, an entertainment device and a tracking system.

EXEMPLARY EMBODIMENTS

(9) In FIG. 1 A, an exemplary embodiment of a detector 110 for determining a position of at least one object 112 is depicted. The detector 110 in this embodiment or other embodiments of the present invention, may be a stand-alone-detector or may be combined with one or more other detectors. As an example, the detector 110 may form a camera or may be part of a camera. Additionally or alternatively, the detector 110 may be part of a human-machine interface, an entertainment device or a tracking system. Other applications are feasible.

(10) The detector 110 comprises at least one transfer device 114 for imaging the object into an image plane 116. The transfer device 114 has a focal plane 118. The transfer device 114 may have focusing or defocusing effects onto the light beam 126. The transfer device 114 may be realized as one or more of a focusing lens; a defocusing lens; a camera lens; a curved mirror; a diaphragm. In this embodiment, the transfer device 114 may be or may comprise a lens.

(11) The object 112 may be illuminated by illumination light 120. The illumination light 120 may be ambient light from a natural and/or an artificial light source. Additionally or alternatively, the detector 110 may comprise at least one illumination source, for example a laser, in particular an IR laser diode, a light-emitting diode, an incandescent lamp, an organic light source, in particular an organic light-emitting diode. The illumination source may emit illumination light 120, which may illuminate the object 112. For example, the illumination source may be adapted to send out at least two light beams having differing optical properties, for example the at least two light beams may be modulated with different modulation frequencies.

(12) Further, the detector 110 comprises at least one longitudinal optical sensor 122. The detector 110 may comprise one or more longitudinal optical sensors 122. The longitudinal optical sensor 122 has at least one sensor region 124. The longitudinal optical sensor 122 is at least partially transparent. The illuminated object 112 may reflect the impinging light. Thus, at least one light beam 126 may travel from the object 112 to the detector 110. The longitudinal optical sensor 122 is designed to generate at least one longitudinal sensor signal in a manner dependent on an illumination of the sensor region 124 by at least one light beam 126 traveling from the object 112 to the detector 110. The at least one longitudinal optical sensor 122 may be a FiP-sensor, as discussed above and as discussed in further detail e.g. in WO 2012/110924 A1. Thus, the longitudinal sensor signal, given the same total power of the illumination, is dependent on a beam cross-section of a light beam 126 in the sensor region 124.

(13) An axis orthogonally to a surface of the longitudinal optical sensor 122 may define an optical axis 128. The optical axis 128 defines a longitudinal axis or z-axis, wherein a plane perpendicular to the optical axis 128 defines an x-y-plane. Thus, in FIG. 1 A, a coordinate system 130 is shown, which may be a coordinate system of the detector 110 and in which, fully or partially, at least one item of information regarding the position of the object 112 may be determined.

(14) Further, the detector 110 comprises an evaluation device 129 designed to generate at least one item of information on a longitudinal position of the object 112 by evaluating the longitudinal sensor signal. The evaluation device 129 may contain one or more data processing devices 130 and/or one or more data memories 132. The evaluation device 129 may be adapted to perform a frequency analysis, in particular a Fourier analysis, of the longitudinal sensor signal. Thus, in case the detector comprises at least one illumination source, the illumination source may send out more than one light beam of illumination light, each light beam modulated with a different modulation frequency, the evaluation device 129 may be adapted to determine the signal components of the longitudinal sensor signal of each light beam. The evaluation device 129 may be connected to the longitudinal optical sensors 122 and if present the illumination source by one or more connectors 134. Further, the connector 134 may comprise one or more drivers and/or one or more measurement devices for generating sensor signals.

(15) The longitudinal optical sensor 122 comprises a focal longitudinal optical sensor 136. The focal longitudinal optical sensor 126 at least substantially is arranged in the focal plane 118. The focal longitudinal optical sensor 136 may be spaced apart from the focal plane 118 by a distance ±ε, wherein |ε|≤0.2.Math.f, with f being the focal length of the transfer device 114. In particular, |ε|≤0.1.Math.f, preferably |ε|≤0.05.Math.f, more preferably |ε|≤0.02.Math.f, and most preferably |ε|≤0.01.Math.f.

(16) The components of the detector 110 may fully or partially be embodied in one or more housings. Thus, the longitudinal optical sensor 122, the transfer device 114 and if present the illumination source may be encased fully or partially within the same housing and/or may fully or partially be encased within separate housings. Further, the evaluation device 129 may fully or partially be integrated into the longitudinal optical sensors 122 and/or into the housing. Additionally or alternatively, the evaluation device 129 may fully or partially be designed as a separate, independent device.

(17) In FIG. 1 B, in addition to the explanations given above with regard to FIG. 1A, another embodiment of the detector 110 is shown. In this embodiment, the detector 118 may comprise a plurality of longitudinal optical sensors 122, which are arranged in a sensor stack 138. The focal longitudinal optical sensor 136 may be arranged apart from the sensor stack 138 or may form part of the sensor stack 138. The stack 138 of longitudinal optical sensors 122 may comprise no more than three longitudinal optical sensors 122. The stack 138 may be composed of longitudinal optical sensors 122 being arranged such that the sensor regions 124 of the longitudinal optical sensors 122 are oriented essentially perpendicularly to an optical axis 128 of the detector 110. For further description of the detector 110 reference can be made to the description of the embodiment shown in FIG. 1 A.

(18) As outlined above, the detector 110, specifically the stack 138, besides the longitudinal optical sensors 122, may comprise one or more additional elements. Thus, as an example, the detector 110, specifically the stack 138, may comprise one or more imaging devices. Thus, as an example, the detector 110 and/or the stack 138 may comprise one or more imaging devices, as symbolically depicted by reference number 139 in FIG. 1 B. The one or more optional imaging devices 139, as an example, may comprise one or more organic and/or one or more inorganic imaging devices such as pixelated imaging devices. As an example, one or more CMOS and/or CCD imaging devices such as CMOS and/or CCD camera chips may be used. Thus, the detector 110 by itself or in conjunction with one or more additional components may be embodied as a camera 111.

(19) In FIG. 2A, longitudinal sensor signal curves j(z) for different focus positions z.sub.f as a function of z are shown. The curves have been calculated for classical ray optics for identical optical systems. As outlined above, the longitudinal optical sensor signal current may decrease with growing distance from the focus z.sub.f. Further, as outlined above, two longitudinal optical sensor signal currents j (z, z.sub.f) and j (z, z′.sub.f) of the same object 112 at two different distances z.sub.f and z′.sub.f normalized to their focus current j.sub.focal (z.sub.1), j.sub.focal (z′.sub.f) respectively, may be considered. These curves, as outlined above, see equations (15) and (16), may intersect at z=z.sub.cross if

(20) $\begin{matrix} \frac{j_{FiP} (z, z_{f})}{j_{focus} (z_{f})} = \frac{j_{FiP} (z, z_{f}^{'})}{j_{focus} (z_{f}^{'})}, & (15) \\ W_{f}^{2} (z, z_{f}) = W_{f}^{2} (z, z_{f}^{'}) . & (16) \end{matrix}$

(21) As outlined above, see equations (17) and (18), for a Gaussian beam the equation simplifies to

(22) $\begin{matrix} {(z_{cross} - z_{f})}^{2} = {(z_{cross} - z_{f}^{'})}^{2} & (17) \\ z_{cross} = \frac{1}{2} \frac{z_{f}^{′2} - z_{f}^{2}}{z_{f}^{'} - z_{f}} . & (18) \end{matrix}$

(23) FIG. 2B shows curves 142 of the longitudinal optical sensor signal 140 for different focus positions normalized to a corresponding longitudinal sensor signal of the focal longitudinal optical sensor 136, wherein in FIG. 2C a magnification of an intersection region 144 is shown. Although theoretically the intersection of the curves 142 remains dependent on the focus position of each curve 142, astonishingly, it was found that for a given optical system, the differences in z.sub.cross for different focal lengths are small, and z.sub.cross falls into a region where the longitudinal optical sensor current is less z-dependent. Further, in general, a given optical system is limited to a certain optical range. Astonishingly, within a typical range of an optical system, a small z range or point close to the focus was found, where all normalized current curves 142 intersect. Thus, measuring the longitudinal optical sensor current at this position or within this intersection range may yield to the normalization of the curve, which is j.sub.focal. As outlined above, the focal longitudinal optical sensor 136 may be spaced apart from the focal plane 118 by a distance ±ε, wherein |ε|≤0.2.Math.f, with f being the focal length of the transfer device 114. For example, |ε|≤0.1.Math.f, preferably |ε|≤0.05.Math.f, more preferably |ε|≤0.02.Math.f, and most preferably |ε|≤0.1.Math.f. The at least one focal longitudinal optical sensor 136 may be arranged to the focal plane 118 such that the at least one focal longitudinal optical sensor 136 lies within the range or point where the curves 142 intersect.

(24) The evaluation device 129 may be adapted to evaluate at least one longitudinal sensor signal j.sub.focal of the focal longitudinal optical sensor 136 and to derive a theoretical longitudinal sensor signal j.sub.image of a hypothetical longitudinal optical sensor in the image plane 116. The evaluation device 129 may be adapted to use, for determining the theoretical longitudinal sensor signal j.sub.image, an assumption that the theoretical longitudinal sensor signal j.sub.image is proportional to the longitudinal sensor signal j.sub.focal of the focal longitudinal optical sensor 136. The evaluation on device 129, for determining the theoretical longitudinal sensor signal j.sub.image, may be adapted to use the above-mentioned equation (19):

(25) $\begin{matrix} \frac{j_{image}}{j_{focal}} = const . & (19) \end{matrix}$

(26) with const. being a predetermined or determinable constant. The evaluation device 129, for determining the theoretical longitudinal sensor signal j.sub.image, may be adapted to use the above-mentioned equation (20):

(27) $\begin{matrix} \frac{j_{image}}{j_{focal}} = c (h_{target}, f_{lens}, l_{lens}) & (20) \end{matrix}$

(28) with c(h.sub.target, f.sub.lens, l.sub.lens) being a predetermined or determinable function dependent on the size h.sub.target of the object 112, the focal length f.sub.lens of the transfer device 114, and the aperture l.sub.lens of the transfer device 114. If the focal longitudinal optical sensor current j.sub.focal is determined and c(h.sub.target, f.sub.lens, l.sub.lens) is known, the theoretical sensor signal j.sub.image can be determined. Thus, it may be avoided to place a longitudinal optical sensor 122 in or close to the image plane 116 to determine the sensor signal in the image plane 116. Further, it may be possible to reduce the amount of longitudinal optical sensors 122 necessary to resolve ambiguities.

(29) In FIG. 3, an exemplary embodiment of the detector 110 used in a human-machine interface 146 is shown. Again, optionally, the detector 110 may be embodied as a camera 111. The human-machine interface 146 comprises at least one detector 110. The human-machine interface 146 may be designed to generate at least one item of geometrical information of the user 148 by means of the detector 110. The human-machine interface 146 may be used to assign to the geometrical information at least one item of information, in particular at least one control command, in order to provide at least one item of information to a machine 150. In the embodiments schematically depicted in FIG. 3, the machine 150 may be a computer and/or may comprise a computer. Other embodiments are feasible. The evaluation device 129 may fully or partially be integrated into the machine 150, such as into the computer. As outlined above, the longitudinal optical sensor 122 and the transfer device 114 may be embodied within housing 152.

(30) The human-machine interface 146 may form part of an entertainment device 154. The machine 150, specifically the computer, may also form part of the entertainment device 154. Thus, by means of the user 148 functioning as the object 112, the user 148 may input at least one item of information, such as at least one control command, into the computer, thereby varying an entertainment function, such as controlling the course of a computer game.

(31) Further, a tracking system 156 for tracking the position of at least one movable object 112 is depicted. The tracking system 156 comprises the detector 110 and, further, at least one track controller 158. The track controller 158 may fully or partially form part of the computer of the machine 150. The track controller 158 is adapted to track a movement of the object 112 from a series of positions of the object 112 at specific points in time.

LIST OF REFERENCE NUMBERS

(32) 110 detector 111 camera 112 object 114 transfer device 116 image plane 118 focal plane 120 illumination light 122 longitudinal optical sensor 124 sensor region 126 light beam 128 optical axis 129 evaluation device 130 coordinate system 131 data processing device 132 data memories 134 connector 136 focal longitudinal optical sensor 138 sensor stack 139 Imaging device 140 curves of longitudinal sensor signal 142 curves 144 intersection region 146 human-machine interface 148 user 150 machine 152 housing 154 entertainment device 156 tracking system 158 track controller

Detector for determining a position of at least one object

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Abstract

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Description