Sensor device, electronic device and method of operating the sensor device

Abstract

A sensor device (1) for detecting gesture inputs (98) and force inputs (99) comprises at least one first emitter (10) configured to emit electromagnetic radiation (L1) of a first wavelength range, at least one second emitter (20) configured to emit electromagnetic radiation (L2) of a second wavelength range that is different from the first wavelength range, at least one detector (30) configured to separately detect electromagnetic radiation (L1, L2) of the first and the second wavelength range, and a deformable membrane (40) arranged in a vertical direction (z) above the first emitter (10), the second emitter (20) and the detector (30), wherein the membrane (40) is more transmissive for the second wavelength range than the for the first wavelength range. The detector (30) is configured to receive electromagnetic radiation (L1, L2) that is emitted by the first and the second emitter (10, 20) and reflected from the membrane (40) and from an object in the vertical direction (z) above the membrane (40). Further an electronic device (100) comprising the sensor device (1) and a method of operating the sensor device (1) is provided.

Description

[0001] Description

[0002] SENSOR DEVICE , ELECTRONIC DEVICE AND METHOD OF OPERATING THE SENSOR DEVICE

[0003] A sensor device and a method of operating the sensor device are speci fied . The sensor device is a sensor device for detecting gesture inputs and force inputs and the method of operating the sensor device is a method of operating the sensor device for detecting gesture inputs and force inputs . Further, an electronic device is provided .

[0004] BACKGROUND OF THE INVENTION

[0005] In the prior art , gestures above a membrane and forces applied to the membrane are usually measured with di f ferent kinds of sensors leading to multiple optical / non-optical sensor combinations . For example , force / touch sensors are implemented as optical or capacitive sensors , while for gesture recognition a separate sensor is required with a high transparent optical window within the membrane .

[0006] At least one obj ect of particular embodiments is to provide a sensor device for detecting gesture inputs and force inputs . A further obj ect of particular embodiments is to provide a method for operating the sensor device . A further obj ect of particular embodiments is to provide an electronic device that comprises the sensor device .

[0007] These obj ects are achieved by the subj ect-matter and the method according to the independent claims . Advantageous embodiments and developments of the subj ect-matter and the method are characteri zed in the dependent claims , and are also disclosed by the following description and the drawings .

[0008] SUMMARY OF THE INVENTION

[0009] According to at least one embodiment , the sensor device is a sensor device for detecting gesture inputs and force inputs .

[0010] The sensor device can be free of non-optical sensors like capacitive sensors and piezoelectric sensors . However, it is also possible that the sensor device combines optical sensors and non-optical sensors . Here and in the following, a "gesture input" can be an input caused by an obj ect , for instance a user' s hand or finger, that is present in the field of illumination of the sensor device , which means that electromagnetic radiation emitted by an emitter can be irradiated on the obj ect , can be reflected by the obj ect and can be detected by a detector . For example , the obj ect can appear and then disappear over the sensor device and / or can move relative to the sensor device , in particular in the field of illumination, so that the reflection of the electromagnetic radiation caused by the obj ect changes over time , which can cause varying detection signals in the sensor device . Furthermore , a " force input" can be understood as an input caused by an obj ect that applies a force to a membrane of the sensor device , so that the membrane is bent and / or moved and / or deformed . In this way, a reflection characteristic, for instance a reflection direction, of the membrane is changed . Detection signals of the sensor device can be intensity signals produced by one or more detectors of the sensor device . According to at least one embodiment , the sensor device comprises at least one first emitter configured to emit electromagnetic radiation of a first wavelength range .

[0011] According to at least one embodiment , the sensor device further comprises at least one second emitter configured to emit electromagnetic radiation of a second wavelength range that is di f ferent from the first wavelength range .

[0012] Here and in the following, electromagnetic radiation may also be referred to as light or radiation . For instance , the first emitter and / or the second emitter can be or can comprise a vertically-emitting laser diode like a VCSEL (vertical-cavity surface-emitting laser ) . In this case , light emission is mainly in a direction that runs perpendicular to a mounting surface on which the respective emitter is mounted . This can mean that the direction in which light is emitted during operation may be parallel to a growth direction of the vertically-emitting laser diode . Alternatively, the first emitter and / or the second emitter can be or can comprise a light-emitting diode , for instance . In this case , the respective emitter can have a broader angular emission distribution and can emit , for instance , light with a Lambertian emission characteristic . By using one or more lenses or other optical elements the emission characteristic of the respective emitter can be adapted . The emitter can comprise more than one VCSEL and / or more than one LED . The first wavelength range is di f ferent from the second wavelength range . This can mean that the first wavelength range and the second wavelength range do not overlap . The sensor device may comprise more than one first emitter and / or more than one second emitter . Thus , a certain degree of redundancy and / or additional functionality can be provided . For example , the plurality of emitters can irradiate di f ferent regions or emit electromagnetic radiation in di f ferent directions . All emitters of the sensor device may form a single integrated component , for instance formed by a plurality of emitters . However, it is also possible that the first emitter and the second emitter are formed by a pixilated emitter .

[0013] In at least one embodiment , the sensor device further comprises at least one detector configured to separately detect electromagnetic radiation of the first and the second wavelength range .

[0014] The at least one detector can be a single detector for detecting electromagnetic radiation of both the first wavelength range and the second wavelength range . The detector may be able to distinguish between the first wavelength range and the second wavelength range . It is also possible that the at least one detector is formed by a first detector for sensing the first wavelength range and by a second detector for sensing the second wavelength range . Alternatively, the detector receives electromagnetic radiation of di f ferent wavelengths with a time delay . This can mean that electromagnetic radiation of the first wavelength range and electromagnetic radiation of the second wavelength range reach the detector subsequently . The at least one detector can comprise a photodiode or an array of photodiodes . For instance , the detector can be formed by discrete photodiodes or can be a part of an integrated detector chip formed by a pixilated photodiode having several detection regions that form the detector and that can be operated independently from each other . The sensor device can comprise more than one detector . Thus , a certain degree of redundancy and / or additional functionality can be provided . For example , the plurality of detectors receives electromagnetic radiation from di f ferent directions or di f ferent regions . Each detector may be assigned to one or more emitters . Alternatively, each emitter may be assigned to one or more detectors .

[0015] Preferably but not necessarily, the emitters and the detector of the sensor device are arranged in such a way that the emitters cannot directly irradiate electromagnetic radiation onto the detector . This can mean that the detector is configured to receive electromagnetic radiation indirectly, in particular by means of reflection . To prevent electromagnetic radiation from directly hitting the detector, a light barrier may be arranged between the emitters and the at least one detector .

[0016] In at least one embodiment , the sensor device further comprises a deformable membrane arranged in a vertical direction above the first emitter, the second emitter and the detector .

[0017] The vertical direction may or at least may substantially correspond to the emission direction of the first and the second emitter and can preferably be a direction perpendicular to a mounting surface on which the first emitter, the second emitter and the detector are arranged . Lateral directions can preferably be directions that are perpendicular to the vertical direction . Consequently, the first emitter, the second emitter and the detector are arranged along a lateral direction . The emitters and the detector have a distance to each other that is measured along that lateral direction . The distance between the emitter and the detector that is configured to detect the respective radiation wavelength of said emitter may also be denoted as baseline in the following .

[0018] In the vertical direction, the membrane has a distance to the first emitter, the second emitter and the detector . In particular, in a reference state of the sensor device , the membrane is arranged at a certain distance from the emitters and the detector measured along the vertical direction . The reference state of the sensor device can preferably be a state in which the sensor device and, in particular, the membrane is not influenced by an external obj ect . In particular, in the reference state the membrane is not touched or pressed by an external obj ect like a user' s hand or finger . Consequently, the membrane has a first height along the vertical direction in the reference state of the sensor device . For instance the height of the membrane can be measured along the vertical direction from a mounting surface , onto which the emitters and the detector are mounted, or from an emission surface of the emitters and / or from a detection surface of the detector or from an upper surface , i . e . a surface of a casting that encapsulates the emitters / detector and that faces the membrane . That the membrane is deformable can mean that the membrane can be bent and / or moved and / or deformed, in particular due to an applied force to the membrane , for example touching or pressing by an external obj ect like a user' s hand or finger . In particular, the membrane can be bent and / or moved towards the emitters and detector ( s ) . Thus , the distance to the first emitter, the second emitter and the detector can be changed depending on the applied force to the membrane . For example , in an operating state , in which the membrane is touched or pressed, the membrane has a second height along the vertical direction that may be smaller than the first height .

[0019] In at least one embodiment , the membrane is more transmissive for the second wavelength range than the for the first wavelength range .

[0020] This can mean that a portion ( in percent ) of electromagnetic radiation of the second wavelength range passes through the membrane . Said portion may be larger than a portion of electromagnetic radiation of the first wavelength range also passing through the membrane . Ideally, electromagnetic radiation of the first wavelength range does not or substantially does not pass through the membrane but is reflected and / or absorbed by the membrane . However, another portion of electromagnetic radiation of the second wavelength range may also be reflected by the membrane .

[0021] In at least one embodiment , the detector is configured to receive electromagnetic radiation that is emitted by the first and the second emitter and reflected from the membrane and from an obj ect in the vertical direction above the membrane .

[0022] As mentioned above , the first emitter and the detector may be arranged such that light emitted by the first emitter does not reach the detector directly . Instead, at least a portion of said light is reflected by the membrane and the reflected light reaches the detector . A main portion of the light emitted by the first emitter can be reflected from the membrane . The detector may detect the intensity of the reflected light . The intensity of the reflected light depends on the height of the membrane , i . e . , the distance between the membrane and the emitter-detector system . Thus , by evaluating the intensity of the reflected light it is possible to determine whether the membrane is deformed and therefore whether a force is applied to the membrane .

[0023] Also the second emitter and the detector may be arranged such that light emitted by the second emitter does not reach the detector directly . Instead, at least a portion of said light passes through the membrane and is possibly reflected by an obj ect above the membrane . For example , said obj ect is a user' s hand or finger . The reflected light passes again through the membrane and hits the detector . The intensity of the reflected light depends on the distance and / or the movement of the obj ect . Thus , by evaluating the intensity of the reflected light it is possible to determine whether a gesture input is applied to the sensor device .

[0024] It is also possible that another ( smaller ) portion of the electromagnetic radiation emitted by the first emitter is transmitted by the membrane and reflected by the obj ect and / or that another portion of the electromagnetic radiation emitted by the second emitter is reflected by the membrane . Thus , as in case of electromagnetic radiation emitted by the first emitter, it is also possible by means of electromagnetic radiation emitted by the second emitter to determine whether a force is applied to the membrane and whether the membrane is deformed . Since the optical properties ( transmissivity, reflectivity, absorbency) of the membrane for di f ferent wavelengths are di f ferent , it can be discriminated between detection signals that indicate force inputs and detection signals that indicate gesture inputs . According to at least one embodiment , an sensor device for detecting gesture inputs and force inputs comprises at least one first emitter configured to emit electromagnetic radiation of a first wavelength range . It further comprises at least one second emitter configured to emit electromagnetic radiation of a second wavelength range that is di f ferent from the first wavelength range . It further comprises at least one detector configured to separately detect electromagnetic radiation of the first and the second wavelength range . It further comprises a deformable membrane arranged in a vertical direction above the first emitter, the second emitter and the detector, wherein the membrane is more transmissive for the second wavelength range than the for the first wavelength range . The detector is configured to receive electromagnetic radiation that is emitted by the first and the second emitter and reflected from the membrane and from an obj ect in the vertical direction above the membrane .

[0025] The sensor device described here is based on the following considerations , among others .

[0026] The sensor device enables multiple applications of force / touch, gesture and swipe recognition with high integration in a single sensor . A highly transparent optical window in the membrane for gesture inputs is not required . By means of the sensor device the human machine interface , HMI , capability of devices like wearables and dashboards is increased .

[0027] The sensor device combines emitters for multiple wavelengths , a multi-channel detector and a semitransparent membrane . The sensor device utili zes the change of reflectivity and / or transmissivity and / or absorbency of the semi-transparent membrane with the wavelength and the ability to emit and detect at di f ferent wavelengths to distinguish between force / touch (movement of the membrane ) and gesture inputs ( light reflection by an obj ect above the membrane ) . That the membrane is semitransparent can mean that it is at least partially transparent / transmissive for a particular wavelength range , in particular the second wavelength range .

[0028] The semitransparent membrane enables a simpler and cost ef fective integration . Further, the additional sensor information of di f ferent integrated functions ( force / touch and gesture / swipe recognition) decreases false detections of single functions .

[0029] By means of electromagnetic radiation of the first wavelength range membrane deformation can be sensed, and thus force inputs can be detected . By means of electromagnetic radiation of the second wavelength range both gesture and force inputs can be detected . Since the first wavelength range is only used to detect force inputs , force and gesture inputs can be distinguished .

[0030] The sensor device can be an all-optical sensor device . This can mean that the sensor device does not comprise non-optical sensors . This reduces complexity of the sensor device .

[0031] In at least one embodiment , the membrane is more reflective for the first wavelength range than the for the second wavelength range .

[0032] This can mean that a portion ( in percent ) of electromagnetic radiation of the first wavelength range is reflected by the membrane . Said portion can be larger than a portion of electromagnetic radiation of the second wavelength range also reflected by the membrane . Ideally, electromagnetic radiation of the first wavelength range is completely or substantially completely reflected by the membrane . However, it is also possible that another portion of electromagnetic radiation of the first wavelength range is absorbed by the membrane . Further, a small portion of electromagnetic radiation of the first wavelength range may also be transmitted by the membrane . By a high reflectivity of the membrane for the first wavelength range as much as possible light from the first emitter reaches the detector . Thus , the signal-to-noise ratio can be increased . To a certain degree the membrane is also reflective for the second wavelength range . Thus , by means of electromagnetic radiation of the second wavelength range both reflection by the membrane and reflection by an obj ect above the membrane can be sensed .

[0033] In at least one embodiment , the membrane is more absorbing for the first wavelength range than the for the second wavelength range .

[0034] This can mean that a portion ( in percent ) of electromagnetic radiation of the first wavelength range is absorbed by the membrane . Said portion may be larger than a portion of electromagnetic radiation of the second wavelength range also absorbed by the membrane . Ideally, the membrane is not or substantially not transmissive for the first wavelength range . Instead, electromagnetic radiation of the first wavelength range is reflected and / or absorbed by the membrane . In this way, measurements of reflection by an obj ect above the membrane are not distorted / falsi fied by electromagnetic radiation of the first wavelength range either from the first emitter under the membrane and / or from a light source above the membrane . In addition, a user is not blinded by light from the first emitter under the membrane .

[0035] In at least one embodiment , the membrane is more scattering for the first wavelength range than the for the second wavelength range .

[0036] This can mean that a portion ( in percent ) of electromagnetic radiation of the first wavelength range is scattered by the membrane . For example , the membrane contains scattering particles . The membrane can contain a filling material , wherein the filling material is tuned for a speci fic transmissivity, reflectivity and / or absorbency of the membrane in dependence of the wavelength range . Thus , light in the second wavelength range can pass through the membrane more freely .

[0037] In at least one embodiment , the membrane comprises a coating .

[0038] The coating can comprise an interference filter . For example , the interference filter can be configured to reflect light in the first wavelength range and to transmit light in the second wavelength range . Alternatively or additionally, the coating comprises a bandpass filter . For example , the bandpass filter is implemented as long-pass filter, so that light in the first wavelength range ( shorter wavelengths ) is blocked and light in the second wavelength range ( longer wavelengths ) is transmitted . Alternatively or additionally, the coating comprises an ambient light filter . By means of the ambient light filter ambient light from above the membrane is blocked . Alternatively or additionally, the coating comprises an anti-reflective coating, ARC . For example , the ARC is configured such that light in the second wavelength range is not reflected or substantially not reflected . Alternatively or additionally, the membrane or the coating of the membrane comprises a luminescent layer, in particular fluorescent layer . For example , a phosphor is added to the membrane . In this case it is possible , for example , that the membrane absorbs light of the first wavelength range and emits light of a third wavelength range to be detected by the detector . Here , the detector is configured to receive electromagnetic radiation that is emitted by the membrane .

[0039] In at least one embodiment , the membrane comprises a plastic material , in particular acrylonitrile butadiene styrene , ABS .

[0040] Preferably, the membrane can comprise a plastic or can be made of plastic, for instance ABS . The material of the membrane is chosen such that the membrane is partly reflective and partly light-transmitting in regard to electromagnetic radiation from the first emitter and the second emitter . In particular, ABS shows a roughly linear dependence of light transmission on the wavelength . For light in the visible spectrum ABS is mainly non-transparent , while it shows a transparency for infrared light . A membrane out of plastic material or ABS is cost ef ficient . Further, depending on the thickness , such a membrane can be deformed . The membrane can be implemented as plate or plate-like part . The membrane can comprise a support structure which holds the membrane at a certain distance to the emitters / detectors . The membrane and / or the support structure can, for example , be inj ection molded as separate parts or in one piece .

[0041] However, it is also possible that the membrane comprises another material . For example , the membrane comprises glass . For example, in cell-phone applications the bezel area / cover of the cell-phone can serve as membrane. Typically, the transmissivity of the bezel area of the cell phone is low for the visible wavelength range but high for the infrared range. For the visible wavelength range the bezel area may be more absorbing than for the infrared wavelength range. Thus, the bezel area may fulfil the requirements for the membrane.

[0042] In at least one embodiment, the membrane has a thickness in the range from 0.1 mm to 1.0 mm, in particular in the range from 0.4 mm to 0.6 mm.

[0043] The thickness of the membrane is chosen such that the membrane is partly reflective and partly light-transmitting in regard to electromagnetic radiation from the first emitter and the second emitter. For example, the thickness of the membrane is equal to or is around 0.5 mm.

[0044] In at least one embodiment, a total transmissivity of the membrane is greater for the second wavelength range than for the first wavelength range.

[0045] The total transmissivity may refer to a transmissivity including scattering effects by the membrane.

[0046] In at least one embodiment, a ratio of the total transmissivity for the second wavelength and the total transmissivity for the first wavelength may be greater than 1.5, 2, 3, 4, 5 or 10.

[0047] By a sufficiently high absolute transmissivity for the second wavelength range it is possible that light of the second wavelength range can pass the membrane for reflection by an obj ect above the membrane . This reflected light can pass the membrane again and can be detected by the detector .

[0048] A gesture event , such as an appearance , presence , and disappearance or position change of an obj ect above the membrane will change the amount of light of the second wavelength range that is detected by the detector .

[0049] In at least one embodiment , a total reflectivity of the membrane is greater for the first wavelength range than for the second wavelength range .

[0050] The total reflectivity may refer to a reflectivity including scattering ef fects by the membrane . In at least one embodiment , a ratio of the total reflectivity for the first wavelength range and the total reflectivity for the second wavelength range may be greater than 0 . 5 , 1 , 2 , or 10 .

[0051] By a suf ficiently high absolute reflectivity for the first wavelength range it is possible that light of the first wavelength range is reflected by the membrane and then is detected by the detector .

[0052] A force event will change the membrane ' s position relative to the detector and this will change the amount of light of the first wavelength range that is detected by the detector .

[0053] In at least one embodiment , the detector is a spectral detector .

[0054] As mentioned above , the at least one detector can be a single detector for detecting electromagnetic radiation of both the first wavelength range and the second wavelength range . As spectral detector it may able to distinguish between the first wavelength range and the second wavelength range . Thus , it can be distinguished between force inputs and gesture inputs as the di f ferent wavelength ranges are used for distinct functions . The detector can be provided with respective wavelength filters . For example , a first wavelength filter is provided for detecting electromagnetic radiation in the first wavelength range . A second wavelength filter is provided for detecting electromagnetic radiation in the second wavelength range . Advantageously, only a single detector is required to detect both wavelength ranges , which reduces complexity and cost .

[0055] In at least one embodiment , the at least one detector comprises a first detector element configured to detect electromagnetic radiation of the first wavelength range and a second detector element configured to detect electromagnetic radiation of the second wavelength range .

[0056] It is also possible that the at least one detector comprises more than one first detector element and / or more than one second detector element . The detector elements can be provided with respective wavelength filters . For instance , the detector elements can be formed by discrete photodiodes or can be a part of an integrated detector chip formed by a pixilated photodiode having several detection regions that form the detector and that can be operated independently from each other . Two discrete detector elements can be arranged spaced from each other . Thus , crosstalk can be prevented .

[0057] In at least one embodiment , the first emitter is a visible light emitter, in particular a blue light emitter, and the second emitter is an infrared light emitter . Thus , the first wavelength range can be the visible , in particular blue wavelength range . The second wavelength range can be the infrared wavelength range . Advantageously, the two wavelength ranges do not overlap, so that false detection is avoided . Further, though part of the infrared light is transmitted by the membrane , a user is not blinded as infrared is invisible for the human eye . In contrast , visible light from the first emitter is not or substantially not transmitted by the membrane as it is reflected and / or absorbed . Blue light emitters and infrared light emitters can be fabricated cost-ef f iciently . Further, visible and infrared light can easily be detected, for example by silicon photodiodes .

[0058] In at least one embodiment , the first emitter, the second emitter and the detector are arranged on a common substrate .

[0059] The substrate may be referred to as carrier . For example , the emitters and the detector are mounted and electrically connected on the carrier which can be , for example , a printed circuit board, PCB, or a ceramic carrier or a package housing . By mounting all components on a common substrate the integration is increased . Further, the substrate may form a reference level in the vertical direction regarding the distance to the membrane .

[0060] In at least one embodiment , the first emitter and the second emitter have an overlapping field of illumination .

[0061] The field illumination of an emitter defines the light cone emitted by the emitter . That the field of illumination of both emitters is overlapping can mean that they have at least a similar field of illumination . Thus , sensing at the same location on or above the membrane is enabled .

[0062] Further, an electronic device is provided . The electronic device comprises the sensor device as described above . This means that all features disclosed for the sensor device are also disclosed for the electronic device and vice versa .

[0063] The electronic device can be a mobile device or a wearable device or a dashboard, in particular an automotive dashboard . The electronic device can also be a touch display . For example , the electronic device is or is employed in a cellphone , a headset , wireless earbuds , a laptop, a tablet , a TV or a smart watch .

[0064] Further, a method of operating a sensor device is provided . The method of operating can preferably be carried out with the sensor device described above . This means that all features disclosed for the sensor device are also disclosed for the method of operating the sensor device and vice versa .

[0065] In at least one embodiment , the method of operating is a method of operating a sensor device for detecting gesture inputs and force inputs . The sensor device can be free of non-optical sensors like capacitive sensors and piezoelectric sensors .

[0066] According to at least one embodiment , the method comprises emitting, by a first emitter, electromagnetic radiation of the first wavelength range .

[0067] According to at least one embodiment , the method comprises emitting, by a second emitter, electromagnetic radiation of a second wavelength range that is di f ferent from the first wavelength range .

[0068] According to at least one embodiment , the method comprises generating a first detection signal based on detecting, by a detector, electromagnetic radiation emitted by the first emitter .

[0069] According to at least one embodiment , the method comprises generating a second detection signal based on detecting, by the detector, electromagnetic radiation emitted by the second emitter .

[0070] The detected electromagnetic radiation is reflected by a deformable membrane arranged in the vertical direction above the first emitter, the second emitter and the detector and / or reflected by an obj ect in the vertical direction above the membrane . The membrane is more transmissive for the second wavelength range than the for the first wavelength range .

[0071] The first detection signal can be an intensity signal , i . e . it is based on a light intensity of the reflected light . In particular, the light intensity can depend on a distance between the membrane and the emitter-detector system and can further depend on the baseline of the emitter-detector system . This can mean that the baseline determines a characteristic curve defining a dependency of the intensity signal on the height of the membrane . I f the height of the membrane changes , e . g . due to force inputs , the first detection signal changes , too . Thus , force inputs can be sensed . The first detection signal may be a continuous signal or it may be a discrete signal in time . Also the second detection signal can be an intensity signal . In particular, the light intensity can depend on the proximity or movement of the obj ect above the membrane and can further depend on the baseline of the emitter-detector system . This can mean that the baseline determines a characteristic proximity curve defining a dependency of the intensity signal from the proximity / movement of the obj ect . I f an obj ect , e . g . a user' s hand or finger, appears , moves , or disappears , the second detection signal changes . Thus , gesture inputs can be sensed . The second detection signal may be a continuous signal or it may be a discrete signal in time .

[0072] According to at least one embodiment , a method of operating a sensor device for detecting gesture inputs and force inputs comprises emitting, by a the first emitter, electromagnetic radiation of a first wavelength range ; emitting, by a second emitter, electromagnetic radiation of a second wavelength range that is di f ferent from the first wavelength range ; generating a first detection signal based on detecting, by a detector, electromagnetic radiation emitted by the first emitter ; and generating a second detection signal based on detecting, by the detector, electromagnetic radiation emitted by the second emitter, wherein the detected electromagnetic radiation is reflected by a deformable membrane arranged in the vertical direction above the first emitter, the second emitter and the detector and / or reflected by an obj ect in the vertical direction above the membrane , wherein the membrane is more transmissive for the second wavelength range than the for the first wavelength range .

[0073] The method enables multiple applications of force / touch, gesture and swipe recognition with high integration in a single sensor . The method utili zes emitters for multiple wavelengths , a multi-channel detector and a semitransparent membrane . The method utili zes the di f ference in reflectivity and / or transmissivity and / or absorbency of the semitransparent membrane for di f ferent wavelengths and the ability to emit and detect at di f ferent wavelengths to distinguish between force / touch (movement of the membrane ) and gesture inputs ( light reflection by an obj ect above the membrane ) . The additional sensor information of di f ferent integrated functions ( force / touch and gesture / swipe recognition) decreases false detections of single functions . By means of electromagnetic radiation of the first wavelength range membrane deformation can be sensed, and thus force inputs can be detected . By means of electromagnetic radiation of the second wavelength range both gesture and force inputs can be detected . Since the first wavelength range is only used to detect force inputs , force and gesture inputs can be distinguished .

[0074] In an embodiment , the second detection signal contains information on proximity / distance of an obj ect above the membrane and also information on the membrane distance , as part of the electromagnetic radiation of the second wavelength range is transmitted by the membrane and part is reflected by the membrane . This means that the second detection signal is based on detecting, by the detector, electromagnetic radiation emitted by the second emitter and reflected by the membrane and / or reflected by an obj ect above the membrane . Thus , by means of the second detection signal gesture and force inputs can be sensed . In a possible implementation, changes of the second detection signal di f fer in sign ( opposite sign) depending on whether force inputs or gesture inputs are applied . According to at least one embodiment, the method further comprises observing for changes in the first detection signal and / or the second detection signal that indicate a deformation of the membrane due to a force input.

[0075] As mentioned above, the first detection signal and the second detection signal may be continuous or discrete signal. They may be compared to a reference level. For example, the reference level describes the reference state of the membrane. If the membrane is moved / pressed / touched the height of the membrane changes leading to a change in the first detection signal and / or the second detection signal. Thus, a force input can be sensed.

[0076] According to at least one embodiment, the method further comprises observing for changes in the second detection signal that indicate an appearance or disappearance of an object above the membrane due to a gesture input.

[0077] The second detection signal may be compared to a further reference level. For example, the further reference level describes a state of the sensor device, where no object is present above the membrane. If an object appears, moves or disappears the second detection signal changes. Thus, a gesture input can be sensed. The change of the second detection signal due to a gesture input may differ from a change of the second detection signal due to a force input. For example, the changes differ in sign.

[0078] According to at least one embodiment, electromagnetic radiation of the first wavelength range and / or electromagnetic radiation of the second wavelength range is emitted by the respective emitters in a continuous mode . Emitting electromagnetic radiation of the first wavelength and emitting electromagnetic radiation of the second wavelength range can be carried out simultaneously .

[0079] According to at least one embodiment , electromagnetic radiation of the first wavelength range and / or electromagnetic radiation of the second wavelength range is emitted by the respective emitters in a pulsed mode . Emitting electromagnetic radiation of the first wavelength and emitting electromagnetic radiation of the second wavelength range can be carried out simultaneously .

[0080] In addition or alternatively, emitting electromagnetic radiation of the first wavelength range and emitting electromagnetic radiation of the second wavelength range are performed subsequently . This can mean that the first emitter emits light pulses at di f ferent times than the second emitter so that the detector can distinguish between light pulses from the first emitter and from the second emitter j ust by timing . This mode of operation may be in particular relevant , i f the detector cannot distinguish between di f ferent wavelengths . In this case , a distinction can be made between the di f ferent functions / measurement methods on the basis of the time sequence .

[0081] Further embodiments of the method become apparent to the skilled reader from the embodiments of the sensor device described above .

[0082] BRIEF DESCRIPTION OF THE DRAWINGS The following description of figures may further illustrate and explain aspects of the sensor device , the electronic device and the method of operating the sensor device . Components and parts of the sensor device that are functionally identical or have an identical ef fect are denoted by identical reference symbols . Identical or ef fectively identical components , parts and steps might be described only with respect to the figures where they occur first . Their description is not necessarily repeated in successive figures .

[0083] Figure 1 shows a sensor device according to an embodiment .

[0084] Figures 2A to 2C show di f ferent views on a sensor package according to another embodiment of the sensor device .

[0085] Figure 3 shows an electronic device according to an embodiment .

[0086] Figures 4A and 4B show transmission characteristics of membranes according to embodiments of the sensor device .

[0087] Figure 5 shows an exemplary operating method of the sensor device according to Figure 1 .

[0088] Figure 6 shows another exemplary operating method of the sensor device according to Figure 1 .

[0089] Figures 7A and 7B show possible detection signals in response to force and gesture inputs according to an embodiment of the operating method .

[0090] DETAILED DESCRIPTION In Figure 1 an embodiment of a sensor device 1 is shown . The sensor device 1 is a sensor device 1 for detecting gesture inputs 98 and force inputs 99 as further described below in context of Figures 5 and 6 . The shown sensor device 1 is free of non-optical sensors .

[0091] The sensor device 1 comprises a first emitter 10 configured to emit electromagnetic radiation LI of a first wavelength range . The sensor device 1 can comprise more than one first emitter 10 (not shown in Figure 1 ) . The sensor device 1 further comprises a second emitter 20 configured to emit electromagnetic radiation L2 of a second wavelength range that is di f ferent from the first wavelength range . The sensor device 1 can comprise more than one second emitter 10 (not shown in Figure 1 ) . Possibly, the first emitter 10 is a visible light emitter 10 , in particular a blue light emitter 10 , and the second emitter 20 is an infrared light emitter 20 . The first emitter 10 and / or the second emitter 20 can be implemented as VCSELs or as LEDs , for example . Electromagnetic radiation LI , L2 emitted by the emitters 10 , 20 is indicated by respective light cones . The light cones indicate the respective fields of illumination of the emitters 10 , 20 , which are at least partially overlapping .

[0092] The sensor device 1 further comprises a detector 30 configured to separately detect electromagnetic radiation LI , L2 of the first and the second wavelength range . The sensor device 1 can comprise more than one detector 30 (not shown in Figure 1 ) . The detector 30 can be implemented as spectral detector 30 . In the shown example , the detector 30 comprises a first detector element 31 configured to detect electromagnetic radiation LI of the first wavelength range and a second detector element 32 configured to detect electromagnetic radiation L2 of the second wavelength range . The first and the second detector element 31 , 32 may be implemented as pixels of the detector 30 . However, it is also possible that the first and the second detector element 31 , 32 are implemented as separate detectors 30 . In the shown example , the first emitter 10 and the second emitter 20 are arranged on the same side of the detector 30 along a lateral direction x . However, other arrangements are also possible .

[0093] The illustrated sensor device 1 further comprises a deformable membrane 40 . The membrane 40 is arranged in the vertical direction z above the first emitter 10 , the second emitter 20 and the detector 30 . The vertical direction z is perpendicular to the lateral direction x and may in particular be in a direction at which the emitters 10 , 20 emit electromagnetic radiation LI , L2 . The membrane 40 is more transmissive for the second wavelength range than for the first wavelength range . Thus , a portion L2 ' ' of electromagnetic radiation L2 of the second wavelength range passes through the membrane 40 , as indicated in the figure . The membrane 40 might be not transmissive or substantially not transmissive for the first wavelength range . The membrane 40 can comprise glass or a plastic material as for example acrylonitrile butadiene styrene , ABS . The membrane can also comprise a coating (not shown) . The membrane 40 has a thickness which refers to an extent of the membrane 40 in the vertical direction z .

[0094] The detector 30 is configured to receive electromagnetic radiation LI that is emitted by the first emitter 10 and reflected from the membrane 40 . Thus , a portion LI ' of electromagnetic radiation LI of the first wavelength range is reflected by the membrane 40 and reaches the detector element 31 , as indicated in Figure 1 .

[0095] The detector 30 is further configured to receive electromagnetic radiation L2 that is emitted by the second emitter 20 and reflected from an obj ect in the vertical direction z above the membrane 40 ( shown in Figure 6 ) . Thus , the portion L2 ' ' of electromagnetic radiation L2 that passes through the membrane 40 may potentially be reflected by an obj ect and reach the detector element 32 .

[0096] The membrane 40 further exhibits a certain reflectivity for wavelengths in the second wavelength range . Thus , a portion L2 ' of electromagnetic radiation L2 emitted by the second emitter 20 is also reflected by the membrane 40 and reaches the detector element 32 . However, the membrane 40 can be more reflective for the first wavelength range than the for the second wavelength range .

[0097] The first emitter 10 , the second emitter 20 and the detector 30 are arranged on a common substrate 50 that can be implemented as printed circuit board or the like . A casting 60 encapsulates the emitters 10 , 20 and the detector 30 . The casting can comprise a material like a transparent plastic material such as silicone . Thus , the emitters 10 , 20 , the detector 30 , the substrate 50 and the casting 60 form a compact sensor package 70 that is part of the sensor device 1 . In a reference state , the membrane 40 has a distance along the vertical direction z to an upper surface of the casting 60 . The distance can be referred to as first height dl .

[0098] Figures 2A to 2C show various views of the sensor package 70 of a sensor device 1 that is similar to the embodiment shown in Figure 1 but has a first emitter 10, a second emitter 20 and a detector 30 comprising twelve detector elements 31, 32. Figure 2A shows a top view, Figure 2B shows a cross-section, and Figure 2C shows a perspective view. The detector 30 may form an integrated detector chip 30, wherein the detector elements 31, 32 form different pixels / detection segments of the detector chip 30. The assignment of the individual detector elements 31, 32 to the respective emitters 10, 20 is arbitrary. It should be noted that different first detector elements 31 and / or second detector elements 32 may have different distances in the lateral directions x, y to the respective emitters 10, 20 to which they are assigned. Thus, there may be different baselines of emitter-detector pairs, which leads to different characteristic proximity curves of the emitter-detector pairs. Furthermore, it is possible that the detector chip 30 provides some integrated logic for controlling the emitters 10, 20, measuring the intensity signals of the detectors elements 31, 32 and calculating various difference signals from the various intensity signals. The detector elements 31, 32 are electrically connected via interconnections 80 to the substrate 50.

[0099] In Figure 3 a schematic of an electronic device 100 is shown, which comprises the sensor device 1 as described above. For example, the electronic device 100 is a mobile device or a wearable device or an automotive dashboard. For example, the electronic device 100 is or is employed in a cellphone, a headset, wireless earbuds, a laptop, a tablet, a TV or a smart watch.

[0100] In Figures 4A and 4B transmission characteristics of membranes 40 according to embodiments of the sensor device 1 are shown. The transmission (in percent) is shown in dependence on the wavelength (in nanometer, nm) . Figure 4A shows the transmission characteristic of an exemplary membrane 40 made of ABS with a thickness of 0.5 mm. It can be seen that the transmission substantially linearly increases with the wavelength. For example, in the blue wavelength range (420 - 490 nm) the transmission of the membrane is around 2 %, while in the infrared range (e.g. near-infrared from 780 nm to 1.8pm) the transmission is around 10 %. Thus, the membrane 40 is more transmissive for the infrared wavelength range than the for the blue wavelength range, which makes it suitable for the described applications. Figure 4B shows transmission characteristics of various materials used as cover for cell-phones (in particular materials in the bezel area of cell-phones) . Here, a high absorption in the visible wavelength range can be observed resulting in a low transmission in this regime. On the other side, there is a high transmission in the infrared wavelength range. Thus, also cover materials in cell-phones, in particular the bezel area of cell-phones, can serve as membrane 40.

[0101] In Figure 5 an exemplary operating method of the sensor device 1 according to Figure 1 is shown.

[0102] The operating method comprises emitting, by the first emitter 10, electromagnetic radiation LI of the first wavelength range. It further comprises emitting, by the second emitter 20, electromagnetic radiation L2 of the second wavelength range that is different from the first wavelength range. The electromagnetic radiation LI, L2 is emitted towards the membrane 40. A force input 99 is applied to the membrane 40 of the sensor device 1 , as indicated by a user' s finger pressing / touching the membrane 40 . By means of the force input 99 the height of the membrane 40 changes . For example , in the reference state the membrane 40 had a height dl , wherein the height is defined as the distance between the membrane 40 and the upper surface of the sensor package 70 . By pressing the membrane 40 the distance decreases at least locally so that a part of the membrane 40 has the height d2 .

[0103] The operating method further comprises generating a first detection signal S I ( as shown in Figure 7A) based on detecting, by the detector 30 , electromagnetic radiation LI emitted by the first emitter 10 and reflected by the deformable membrane 40 . This means that the portion LI ' of the electromagnetic radiation LI that is reflected by the membrane 40 reaches the detector 30 , in particular the first detector element 31 , and causes the detection signal S I which can be an intensity signal . The detection signal S I depends on the height of the membrane 40 . For example , the intensity of the reflected light increases or decreases with varying the height of the membrane 40 .

[0104] Moreover, the method may further comprise generating a second detection signal S2 ( as shown in Figure 7B ) based on detecting, by the detector 30 , electromagnetic radiation L2 emitted by the second emitter 20 and reflected by the membrane 40 . This means that a portion L2 ' of the electromagnetic radiation L2 that is reflected by the membrane 40 reaches the detector 30 , in particular the second detector element 32 , and causes the detection signal S2 which can be an intensity signal . The detection signal S2 depends on the height of the membrane 40 . For example , the intensity of the reflected light increases or decreases with varying the height of the membrane 40 .

[0105] As mentioned above , the membrane 40 is also transmissive for the second wavelength range so that a portion L2 ' ' of the electromagnetic radiation L2 emitted by the second emitter 20 passes through the membrane 40 . This portion L2 ' ' can be used for gesture and / or proximity measurements as shown in Figure 6 .

[0106] In Figure 6 a gesture input 98 is applied as indicated by a user' s hand above the membrane 40 . The portion L2 ' ' is reflected by the hand and reaches the detector 30 , in particular the second detector element 32 . Thus , generating the second detection signal S2 is also based on detecting, by the detector 30 , electromagnetic radiation L2 emitted by the second emitter 20 and reflected by an obj ect in the vertical direction z above the membrane 40 . The detection signal S2 may change depending on the proximity and / or the movement and or the shape and / or the material of the obj ect . This means that the intensity of the received light may increase or decrease .

[0107] The membrane 40 may be non-transparent / opaque or at least less transmissive for the first wavelength range so that a gesture input is not detected by the first detector element 31 .

[0108] In Figure 7A an exemplary first detection signal S I is shown . The x-axis shows a sequence of samples s . On the y-axis analog-to-digital converter counts c, which corresponds to the intensity of the first detection signal S I , are shown . In the shown example the detection signal S I comprises a first channel CHI, a second channel CH2 and a difference signal CH1-CH2. For example, the first channel CHI and the second channel CH2 are realized by two emitter-detector pairs with different baselines. The first channel CHI may be generated by a first detector element 31 with a first distance to the first emitter 10, while the second channel CH2 may be generated by a further first detector element 31' with a second distance to the first emitter 10. Alternatively, two first emitters 10 may have different distances to a common detector 30, or the channels are realized by separate emitter-detector pairs. In a further alternative, the channels CHI and CH2 are based on different wavelength sensitivities of detector elements 31, 31' . The first and the second channel CHI, CH2 are shown DC compensated.

[0109] With the first detection signal SI gesture inputs 98 are not sensed. However, the first detection signal SI shows responses to three increasing force inputs 99. The first channel CHI and the second channel CH2 are inverse and have different signs. Thus, the difference signal CH1-CH2 can be increased. By observing changes in the first detection signal SI, that indicate a deformation of the membrane 40, force inputs 99 can be detected and these force inputs 99 can be distinguished from gesture inputs 98. It should be noted that, in a possible implementation, the sensor device 1 generates more than one first detection signal SI (e.g. by means of more than one first emitter 10 and / or more than one detector 30) , in order to detect force inputs 99 on different areas of the membrane 40 and to increase the spatial resolution .

[0110] In Figure 7B an exemplary detection signal S2 is shown.

[0111] Again, the x-axis shows a sequence of samples s, while on the y-axis analog-to-digital converter counts c are shown. The detection signal S2 also comprises a first channel CHI, a second channel CH2 and a difference signal CH1-CH2, which can be realized similarly to the case of the first detection signal SI, as described above. The first and the second channel CHI, CH2 are shown DC compensated.

[0112] It is shown that changes in the second detection signal S2 can indicate both deformation of the membrane 40 due to force inputs 99 and appearance / disappearance of an object above the membrane 40 due to gesture inputs 98. It should be noted that, in a possible implementation, the sensor device 1 can generate more than one second detection signal S2 (e.g. by means of more than one second emitter 10 and / or more than one detector 30) , in order to detect force inputs 99 and gesture inputs on different areas of the membrane 40 and to increase the spatial resolution. By triangulation of detected signals one can extract two different measures: membrane displacement and / or deformation as well as location of objects above the membrane 40. Forces applied to the membrane 40 can be calculated from the membrane displacement / def ormation signal.

[0113] In the shown example, the difference signal CHI - CH2 of the second detection signal S2 changes inversely depending on whether a gesture input 98 or a force input 99 is applied. This response can be caused by the baseline, which defines a special characteristic proximity curve of the CHI and CH2 emitter-detector pair. Thus, it is possible to distinguish between gesture inputs 98 and force inputs 99.

[0114] The embodiments of the sensor device 1, the electronic device 100 and the method of operating the sensor device 1 disclosed herein have been discussed for the purpose of familiarizing the reader with novel aspects of the idea . Although preferred embodiments have been shown and described, many changes , modi fications , equivalents and substitutions of the disclosed concepts may be made by one having skill in the art without unnecessarily departing from the scope of the claims .

[0115] It will be appreciated that the disclosure is not limited to the disclosed embodiments and to what has been particularly shown and described herein above . Rather, features recited in separate dependent claims or in the description may advantageously be combined . Furthermore , the scope of the disclosure includes those variations and modi fications , which will be apparent to those skilled in the art and fall within the scope of the appended claims .

[0116] The term " comprising" , insofar it was used in the claims or in the description, does not exclude other elements or steps of a corresponding feature or procedure . In case that the terms " a" or " an" were used in conj unction with features , they do not exclude a plurality of such features . Moreover, any reference signs in the claims should not be construed as limiting the scope .

[0117] This patent application claims the priority of German patent application 102023122542 . 1 , the disclosure content of which is hereby incorporated by reference . References

[0118] 1 sensor device

[0119] 10 first emitter

[0120] 20 second emitter

[0121] 30 detector

[0122] 31 first detector element

[0123] 32 second detector element

[0124] 40 membrane

[0125] 50 substrate

[0126] 60 casting

[0127] 70 sensor package

[0128] 80 interconnection

[0129] 98 gesture input

[0130] 99 force input

[0131] 100 electronic device dl first height d2 second height

[0132] LI electromagnetic radiation of first wavelength range

[0133] L2 electromagnetic radiation of second wavelength range

[0134] 51 first detection signal

[0135] 52 second detection signal x, y lateral directions z vertical direction

Claims

Claims1. A sensor device (1) for detecting gesture inputs (98) and force inputs (99) , comprising:- at least one first emitter (10) configured to emit electromagnetic radiation (LI) of a first wavelength range,- at least one second emitter (20) configured to emit electromagnetic radiation (L2) of a second wavelength range that is different from the first wavelength range,- at least one detector (30) configured to separately detect electromagnetic radiation (LI, L2) of the first and the second wavelength range,- a deformable membrane (40) arranged in a vertical direction (z) above the first emitter (10) , the second emitter (20) and the detector (30) , wherein the membrane (40) is more transmissive for the second wavelength range than the for the first wavelength range, and- wherein the detector (30) is configured to receive electromagnetic radiation (LI, L2) that is emitted by the first and the second emitter (10, 20) and reflected from the membrane (40) and from an object in the vertical direction (z) above the membrane (40) .

2. The sensor device (1) according to the preceding claim, wherein the membrane (40) is more reflective and / or more absorbing and / or more scattering for the first wavelength range than the for the second wavelength range.

3. The sensor device (1) according to one of the preceding claims, wherein the membrane (40) comprises a coating, the coating being an interference filter, a bandpass filter, anambient light filter, an anti-reflective coating, a luminescent layer or a combination thereof.

4. The sensor device (1) according to one of the preceding claims, wherein the membrane (40) comprises glass or a plastic material, in particular acrylonitrile butadiene styrene, ABS .

5. The sensor device (1) according to one of the preceding claims, wherein the membrane (40) has a thickness in the range from 0.1 mm to 1.0 mm, in particular in the range from 0.4 mm to 0.6 mm.

6. The sensor device (1) according to one of the preceding claims, wherein a ratio of a total transmissivity of the membrane (40) for the second wavelength and a total transmissivity of the membrane for the first wavelength is greater than 1.5.

7. The sensor device (1) according to one of the preceding claims, wherein a ratio of a total reflectivity of the membrane (40) for the first wavelength range and a total reflectivity of the membrane (40) for the second wavelength range is greater than 0.5, in particular greater than 1.

8. The sensor device (1) according to one of the preceding claims, wherein the detector (30) is a spectral detector (30) .

9. The sensor device (1) according to one of the preceding claims, wherein the at least one detector (30) comprises a first detector element (31) configured to detect electromagnetic radiation (LI) of the first wavelength rangeand a second detector element (32) configured to detect electromagnetic radiation (L2) of the second wavelength range .

10. The sensor device (1) according to one of the preceding claims, wherein the first emitter (10) is a visible light emitter (10) , in particular a blue light emitter (10) , and the second emitter (20) is an infrared light emitter (20) .

11. The sensor device (1) according to one of the preceding claims, wherein the first emitter (10) , the second emitter (20) and the detector (30) are arranged on a common substrate (50) .

12. The sensor device (1) according to one of the preceding claims, wherein the first emitter (10) and the second emitter (20) have an overlapping field of illumination.

13. An electronic device (100) comprising the sensor device (1) according to one of the preceding claims, wherein the electronic device (100) is in particular a mobile device, an automotive dashboard or a wearable device.

14. A method of operating a sensor device (1) for detecting gesture inputs (98) and force inputs (99) , comprising:- emitting, by a first emitter (10) , electromagnetic radiation (LI) of a first wavelength range,- emitting, by a second emitter (20) , electromagnetic radiation (L2) of a second wavelength range that is different from the first wavelength range,- generating a first detection signal (SI) based on detecting, by a detector (30) , electromagnetic radiation (LI) emitted by the first emitter (10) , and- generating a second detection signal (S2) based on detecting, by the detector (30) , electromagnetic radiation (L2) emitted by the second emitter (20) ,- wherein the detected electromagnetic radiation (LI, L2) is reflected from a deformable membrane (40) arranged in the vertical direction (z) above the first emitter (10) , the second emitter (20) and the detector (30) and / or reflected from an object in the vertical direction (z) above the membrane (40) ,- wherein the membrane (40) is more transmissive for the second wavelength range than the for the first wavelength range .

15. The method according to claim 14, further comprising observing for changes in the first detection signal (SI) and / or the second detection signal (S2) that indicate a deformation of the membrane (40) due to a force input (99) .

16. The method according to one of claims 14 to 15, further comprising observing for changes in the second detection signal (S2) that indicate an appearance or disappearance of an object above the membrane (40) due to a gesture input (98) .

17. The method according to one of claims 14 to 16, wherein electromagnetic radiation (LI) of the first wavelength range and / or electromagnetic radiation (L2) of the second wavelength range is emitted by the respective emitters (10, 20) in a continuous mode.

18. The method according to one of claims 14 to 16, wherein electromagnetic radiation (LI) of the first wavelength range and / or electromagnetic radiation (L2) of the secondwavelength range is emitted by the respective emitters (10, 20) in a pulsed mode.

19. The method according to one of claims 14 to 18, wherein emitting electromagnetic radiation (LI) of the first wavelength range and emitting electromagnetic radiation (L2) of the second wavelength range are performed subsequently.

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