WO2025153409A1

WO2025153409A1 - Device and method for operating a device

Info

Publication number: WO2025153409A1
Application number: PCT/EP2025/050557
Authority: WO
Inventors: Gunter Siess; Mahmoud JAZAYERI FAR
Original assignee: Ams Osram AG
Current assignee: Ams Osram AG
Priority date: 2024-01-17
Filing date: 2025-01-10
Publication date: 2025-07-24
Anticipated expiration: 2026-07-17

Abstract

A device (1) is provided, comprising a sensor (2) with a light source (3) configured to emit electromagnetic radiation, and a photodiode (4) configured to detect electromagnetic radiation. The device (1) comprises a cover (8), wherein the cover (8) comprises a reflective region (9) on the side of the cover (8) facing the sensor (2), and the reflective region (9) is arranged with a lateral offset to the sensor (2). Furthermore, a method for operating a device is provided.

Description

DEVICE AND METHOD FOR OPERATING A DEVICE

The present disclosure relates to a device and to a method for operating a device.

It is an object to provide a device for efficiently detecting a distance. A further object is to provide a method for operating a device for efficiently detecting a distance, a change in distance and/or a touch force.

According to at least one embodiment of the device, the device comprises a sensor. For instance, the sensor is configured to detect, measure and/or analyze a distance of the sensor to an object. For example, the sensor is or comprises a proximity sensor, in particular an optical proximity sensor. An optical proximity sensor can measure diffuse or direct reflected electromagnetic radiation from the object.

For example, the device comprising the sensor is or comprises a touch sensor. This can mean that the object of which the sensor detects, measures and/or analyzes the distance to the sensor is also comprised by the device. For example, the object may then be an outer surface of the device, in particular a touchable surface of the device. If the surface is touched, the height or warp of the sensor changes. A resulting change of the reflected electromagnetic radiation may correlate with a touch force applied to the surface.

For example, the sensor comprises a main extension direction and/or a main extension plane. For example, an imaginary straight connection between the light source and the photodiode extends in parallel to the main extension plane and/or the main extension direction .

According to at least one embodiment of the device , the sensor comprises a light source . The light source is configured to generate and/or emit electromagnetic radiation . In particular, the light source is configured to emit electromagnetic radiation in the direction of a cover of the device . It is possible , that the electromagnetic radiation emitted by the light source impinges on the side of the cover facing the sensor .

The light source is configured to emit electromagnetic radiation with, for example , any wavelength or any wavelength range of the electromagnetic radiation . In other words , during operation of the light source , the light source may emit electromagnetic radiation with any wavelength or any wavelength range of the electromagnetic radiation . For example , the light source is configured to emit electromagnetic radiation in the UV, visible or IR range .

The light source comprises a field of view . " Field of view" can thereby mean an angular extent of the area illuminated by the light source . For instance , the field of view corresponds to the full width at hal f maximum ( short : FWHM) of the irradiation of the LED .

For example , the light source is or comprises a LED . For example , the light source does not comprise a collimating reflector and/or a lens . Thus , it is possible , that electromagnetic radiation emitted by the light source and impinging on the cover comprises Lambertian characteristics . For example, this means that a field of view of the light source is at least approximately 60°.

Alternatively or additionally, the light source comprises a narrow field of view. Then, for example, the light source is or comprises a laser, in particular a vertical cavity surface emitting laser (VCSEL) . It is also possible, that the light source with a narrow field of view comprises or is a LED, which is covered by an optical element. In this case, the optical element can be configured to adjust the field of view of the LED. For example, a field of view of the light source comprising a narrow field of view is between and including l°hca to 40°hca, for example between 5°hca and 20°hca, inclusive or between 9°hca and 15°hca, inclusive.

According to at least one embodiment of the device, the sensor comprises a photodiode. The photodiode is configured to detect electromagnetic radiation. For instance, the photodiode is configured to detect at least a portion of the electromagnetic radiation emitted by the light source.

It is possible, that the sensor comprises at least one photodiode. For example, the sensor comprises two or more than two photodiodes.

According to at least one embodiment of the device, the device comprises a cover. For example, the cover is the object for which a distance to the sensor may be determined. This can mean that the cover comprises the touchable surface of the device. In other words, the sensor can be configured to detect, measure and/or analyze a distance between the cover and the sensor. The cover, for example a ceil , can be arranged above the sensor in a vertical direction . For instance , a main extension direction of the cover is at least approximately parallel to a main extension direction of the sensor and may run transversely or vertically to the vertical direction . The cover can be configured to warp, to bend and/or to change its distance to the sensor when a force , in particular a touch force , is applied to the side of the cover facing away from the sensor .

The cover may comprise a plastic and/or a glass , for example . However, other materials are also possible . For example , the cover is di f fuse reflective on the side of the cover facing the sensor . In this case , any material resulting in a di f fuse reflectance of the cover, in particular within a reflective region is suitable for forming the cover or at least a part of the cover . Alternatively or additionally, the cover comprises a low reflectivity for the electromagnetic radiation emitted by the light source .

According to at least one embodiment of the device , the cover comprises a reflective region on the side of the cover facing the sensor . The reflective region can be a part , in particular only a part of the cover . For example , the reflective region is a part of the cover which is configured to reflect at least a portion of impinging electromagnetic radiation . For instance , the impinging electromagnetic radiation comprises or corresponds to the electromagnetic radiation emitted by the light source . In other words , the reflective region can be reflective for the electromagnetic radiation emitted by the light source . For example , a reflectance of the reflective region for the electromagnetic radiation emitted by the light source is at least 50% , for example at least 70%, at least 80%, at least 90%, for example at least 95% or at least 99%.

For example, the reflective region is a region of the cover comprising a larger reflectance than another region, e.g. the remaining region, of the cover. In this case, a reflectance of the other region of the cover for the electromagnetic radiation emitted by the light source is at most 20%, in particular at most 10%, for example at most 5%, at most 2% or at most 1%. Alternatively or additionally, the reflective region is a region of the cover onto which the electromagnetic radiation emitted by the light source impinges .

The reflective region may comprise a diffuse reflectance, for example. This can mean that impinging electromagnetic radiation is reflected into a plurality of directions.

The reflective region can comprise a circular shape, a rectangular shape and/or a shape of a ring or ring sector, for example in top view. For example, the reflective region is frame-shaped, e.g. ring-shaped. This can mean that the reflective region completely surrounds a part of a region other than the reflective region of the cover. In other words, the reflective region then completely surrounds a part of the other region of the cover having a larger reflectance. However, the present invention is not limited to the above- mentioned shapes. Moreover, it is possible that the reflective region comprises any other shape.

It is further possible, that the reflective region is contiguous. Alternatively, the reflective region is formed of , or consists of at least two or multiple regions which are arranged spaced apart from each other .

According to at least one embodiment of the device , the reflective region is arranged with a lateral of fset to the sensor . This can mean that a center of the sensor and a center of the cover do not overlap with each other along the vertical direction . For instance , the reflective region of the cover is asymmetrically located with respect to the sensor .

For example , the reflective region does not overlap with the center of the sensor . It is possible , that the reflective region is not arranged above the photodiode along the vertical direction . The reflective region of the cover can overlap with the light source along the vertical direction .

It is also possible , that the reflective region is flush with a side of the light source facing the photodiode along the vertical direction . In particular, the reflective region can protrude the light source on a side of the light source facing away from the photodiode .

In at least one embodiment , the device comprises a sensor with a light source , configured to emit electromagnetic radiation, a photodiode , configured to detect electromagnetic radiation, and a cover . The cover comprises a reflective region on the side of the cover facing the sensor, and the reflective region is arranged with a lateral of fset to the sensor .

An advantage of the device is , amongst others , that it can ef ficiently detect a distance optically . Optical proximity sensors or optical proximity detection are used for force touch sensing, for example . In particular, the device can ef ficiently detect a distance between a target , e . g . the cover, and the sensor for a large distance range and for a larger working distance . For example , the device comprises an increased signal variation of a delta signal f (h) for longer distances between the cover and the sensor . In other words , a di f ference in the delta signal f (h) for two di f ferent distances between the cover and the sensor is increased, in particular for larger distances . A larger distance can be understood to mean a distance larger than 2 mm, for instance 3 mm or for example equal to or larger than 4 mm . For example , the distance is in a range between and including 2 mm and 10 mm . The delta signal depends on the di f ference between the signals detected by the photodiode and a further photodiode . The delta signal f( i) can be calculated according to wherein PD1 corresponds to the signal detected by the photodiode and PD2 corresponds to the signal detected by the further photodiode .

The increase in the signal variation of the delta signal for longer distances can be achieved by prolonging the optical path or the mean optical path of the electromagnetic radiation emitted by the light source prior to impinging on the detector . The optical path is , for example , ef ficiently increased in case the center of the reflective region of the cover does not overlap with the center of the sensor, but protrudes the light source on the side opposing the photodiode . Due to a concentrated reflection, which is , for example , achieved by the reflective region of the cover, the angular depending optical path length in the device can increase . This can lead to a more linear calculated delta signal f (h) over a larger distance range . For instance , this leads to a steeper slope of the delta signal .

According to at least one embodiment of the device , the reflective region does not overlap with the photodiode along a vertical direction . This can ef ficiently suppress or at least decrease the amount of direct reflected electromagnetic radiation within the device . Further, the optical path length of the electromagnetic radiation prior to being detected by the photodiode can be ef ficiently increased .

According to at least one embodiment of the device , the reflective region protrudes the sensor on a side facing away from the photodiode . In particular, this can mean that the reflective region protrudes the light source on a side facing away from or opposing the photodiode . In other words , the reflective region protrudes the sensor on the side at which the light source is arranged . For instance , the reflective region protrudes the sensor along a lateral direction . Thereby, the angular depending optical path length can ef ficiently be increased .

According to at least one embodiment of the device , the sensor comprises a further photodiode , and a distance between the photodiode and the light source is smaller than a distance between the further photodiode and the light source . The photodiode and the further photodiode can be integrated into a common chip . For example , the photodiode is arranged on one side of the chip, while the further photodiode is arranged on the side of the chip opposing the photodiode . In particular, the light source , the photodiode and the further photodiode may be arranged in line . For instance , a distance between the photodiode and the further photodiode is maximi zed .

In a device comprising more than one photodiode , for example two photodiodes , noise and thermal ef fect of the light source can be at least partially compensated . This is achieved, for example , via the signal variations between the two or more photodiodes .

According to at least one embodiment of the device , a distance between the cover and the sensor is larger than a distance between the photodiode and the light source . Due to the reflective region being arranged with a lateral of fset to the sensor, the working range , in particular the suitable distance range between the cover and the sensor for ef ficiently detecting a touch force can be increased .

According to at least one embodiment of the device , the cover comprises a higher reflectance in the reflective region than outside the reflective region . For example , the reflectance in the reflective region is increased . Alternatively, the reflectance outside the reflective region is decreased .

According to at least one embodiment of the device , a reflective pattern is arranged in the reflective region . The reflective pattern may be a white reflective pattern or white reflective sheet , for example . For example , the side of the cover facing the sensor is partially painted with white paint to form or define the reflective region . Alternatively, a reflective pattern or reflective sheet , e . g . a white pattern or white sheet can be partially sticked to the side of the cover facing the sensor to form or define the reflective region. The reflective pattern may comprise a diffuse reflectance, for example.

According to at least one embodiment of the device, a structure is arranged on the side of the cover facing the sensor. For example, the structure is configured to direct impinging electromagnetic radiation away from the sensor.

According to at least one embodiment of the device, a field of view of the light source is at most 20°hca. Alternatively or additionally, the field of view of the light source is within a range from including l°hca to including 60°hca, for example between and including 3°hca and 40°hca, between and including 5°hca and 30°hca or between and including 6°hca and 20°hca. The field of view of the light source can be at most 15°hca, for example at most or exactly 10°hca. A light source comprising a field of view, which is, for example, at most 40°hca is referred to as "narrow". Due to a light source having a narrow field of view, the electromagnetic radiation emitted by the light source can efficiently define the reflective region of the cover and/or impinge only or at least mainly on the reflective region of the cover. For example, the reflective region of the cover is defined by the narrow field of view of the light source.

According to at least one embodiment of the device, a mean direction of the light beam emitted by the light source is tilted with respect to the vertical direction. Due to tilting of the light beam emitted by the light source, the reflective region of the cover can easily be arranged asymmetrically to the sensor, e.g. such that the reflective region of the cover does not overlap the photodiode or the chip or overlaps at most 50% of the photodiode or the chip.

Additionally or alternatively, the light source can be tilted, such that a main extension plane of an out-coupling surface of the light source runs obliquely to the cover.

For example, the light beam emitted by the light source is tilted between and including -60° and 20°, for example between -40° and 5°, inclusive, in particular between -20° and -3°, inclusive or between -16° and -8°, inclusive. A negative amount of tilt corresponds to a tilt in a direction away from the photodiode. The amount of tilt is determined with respect to a surface normal of the main extension plane of the sensor.

According to at least one embodiment of the device, a molded body is arranged on the light source. For example, the molded body comprises a top surface. The top surface of the molded body may, for example, extend at least partially obliquely to a main extension plane of the sensor. For instance, the light beam emitted by the light source is tilted by the molded body. In other words, the molded body can form an optical element on an outcoupling surface of the light source.

According to at least one embodiment of the device, the device comprises a lens. The lens is arranged on the light source. This can also mean that the lens is arranged in the beam path of the light beam emitted by the light source. A center of the lens may not overlap with a center of the light beam emitted by the light source. Such a configuration is suitable to efficiently tilt the light beam of the electromagnetic radiation emitted by the light source. According to at least one embodiment of the device , the device comprises a barrier . The barrier can be arranged between the light source and the photodiode . For instance , the barrier is non-transmissive for the electromagnetic radiation emitted by the light source . For example , the barrier protrudes the light source and/or the photodiode along the vertical direction .

Due to the barrier, direct cross talk between the light source and the photodiode and/or the further photodiode can ef ficiently be reduced or prevented .

According to at least one embodiment of the device , the sensor comprises an integrated signal processing unit . However, additionally or alternatively, it is also possible to have an external processing unit . The signal processing unit can be configured to determine the delta signal , the di f ference between delta signals for di f ferent distances or to identi fy a touch force , for example .

Furthermore , a method for operating a device is provided . The method for operating a device can preferably be performed to operate the device described herein . This means all features disclosed for the device are also disclosed for the method for operating a device and vice-versa .

According to at least one embodiment of the method for operating a device , a light source of a sensor emits electromagnetic radiation . For example , the electromagnetic radiation is subsequently reflected by a reflective region of a cover . The reflected electromagnetic radiation can be detected by a photodiode . For instance , the method is a method for operating a device described herein . In other words , the device can be the device described herein . For example , electromagnetic radiation is only or at least mainly reflected by the reflective region of the cover towards the photodiode and/or a further photodiode .

According to at least one embodiment of the method for operating a device , the device is configured to detect a touch force being applied to the cover . The touch force can in particular be applied from the side of the cover facing away from the sensor . For example , the touch force is applied in a region of the cover opposing the reflective region . Additionally or alternatively, the touch force is applied laterally spaced apart from the reflective region, for example .

Further advantages and advantageous designs and further developments of the device and the method for operating a device will become apparent from the following exemplary embodiments , which are described below in association with the figures .

Figure 1 shows a schematic view of a device according to an exemplary embodiment .

Figures 2A and 2B show schematic irradiance distributions of a device according to an exemplary embodiment .

Figures 3A, 3B, 3C, 3D and 4 show graphs obtainable for a device according to an exemplary embodiment .

Figure 5 shows a schematic view of a device according to an exemplary embodiment . Figures 6 and 7 show schematic views of devices according to further exemplary embodiments .

Figures 8A and 8B show schematic irradiance distributions of a device according to a further exemplary embodiment .

Figures 9A, 9B, 9C, 9D, 10 and 11 show graphs of a further exemplary embodiment .

Figures 12 and 13 show schematic views of a sensor of a device according to an exemplary embodiment .

Figure 14 shows a schematic view of a device according to a comparative example .

Figures 15A and 15B show schematic irradiance distributions of a device according to a comparative example .

Figures 16A, 16B, 16C and 16D show graphs of a comparative example .

Identical , similar or equivalent elements are marked with the same reference signs in the figures . The figures and the proportions of the elements represented in the figures among each other are not to be considered as true to scale . Rather, individual elements may be oversi zed for better representability and/or comprehensibility . Identical or ef fectively identical components and parts might be described only with respect to the figures where they occur first .

Their description is not necessarily repeated in successive figures . Figure 1 shows a schematic view of a device 1 according to an exemplary embodiment. The device 1 comprises a sensor 2 and a cover 8. The sensor 2 comprises a light source 3 and a photodiode 4. The light source 3 is configured to emit electromagnetic radiation. For example, shown here, the light source 3 comprises Lambertian characteristics. The photodiode 4 is configured to detect electromagnetic radiation. The cover 8 comprises a reflective region 9 on the side of the cover 8 facing the sensor 2.

In the exemplary embodiment shown here, the photodiode 4 is comprised by a chip 13. In other words, the chip 13 comprises at least the photodiode. For example, shown here, the light source 3 and the chip 13 comprising the photodiode 4, are arranged on a common carrier 14.

For example, the sensor 2 and/or the chip 13 comprise a further photodiode 5. A distance between the photodiode 4 and the light source 3 can be smaller than a distance between the further photodiode 5 and the light source 3. For example, the light source 3, the photodiode 4 and the further photodiode 5 are arranged along a common straight line. For instance, the photodiode 4 and the further photodiode 5 are arranged spaced apart from each other. A spacing between the photodiode 4 and the further photodiode 5 can be maximized. For example, the spacing between the photodiode 4 and the further photodiode 5 is limited by the size of the device 1, the size of the sensor 2 and/or the size of the chip 13.

The reflective region 9 is arranged with a lateral offset to the sensor 2. For example, the reflective region 9 does not overlap with the photodiode 4 along a vertical direction z. Alternatively, not shown, the reflective region 9 can cover at least 40% , for example at least 20% , at least 10% , at least 5% or at least 1 % of the photodiode 4 or of the chip 13 .

The reflective region 9 protrudes the sensor 2 on a side facing away from the photodiode 4 . For example , the cover 8 comprises a higher reflectance in the reflective region 9 than outside the reflective region 9 . A white ( reflective ) pattern/ref lective sheet 10 is arranged in the reflective region 9 .

A distance between the cover 8 and the sensor 2 is larger than a distance between the photodiode 4 and the light source 3 . In particular, a vertical distance between the cover 8 and the sensor 2 is larger than a lateral distance between the photodiode 4 and the light source 3 .

For example , not shown, a barrier 11 can be arranged between the light source 3 and the photodiode 4 . For example , the barrier 11 is non-transmissive for the electromagnetic radiation emitted by the light source 3 . Due to the barrier 11 a direct crosstalk between the light source 3 and the photodiode 4 can be minimi zed or prevented . Additionally or alternatively, the device 1 , in particular the sensor 2 , can comprise an integrated signal processing unit 12 .

During operating of the device 1 , the light source 3 of the sensor 2 emits electromagnetic radiation . For example , at least a portion of the electromagnetic radiation is then reflected by the reflective region 9 of the cover 8 . For instance , reflected electromagnetic radiation, which is reflected by the reflective region 9 of the cover 8 is detected by the photodiode 4 . Alternatively or additionally, the reflected electromagnetic radiation can be detected by the further photodiode 5 . The device 1 may be configured to detect a touch force being applied to the cover 8 , e . g . from a side of the cover 8 facing away from the sensor 2 .

For example , the sensor 2 comprises a molded body of a molding material . For instance , the light source , the photodiode , the further photodiode and/or the chip 13 are encapsulated by a molding material , in particular by a clear molding material . For example , the clear molding material is or comprises an epoxy . The molding material may be light transmissive . The molding material can form a molded body encapsulating the light source , the photodiode and/or the further photodiode . For example , the molded body is flush with the barrier 11 on a side of the sensor 2 facing the cover 8 .

In Figure 1 , the arrow pointing towards the cover 8 from the side of the cover 8 facing away from the sensor 2 may indicate a force F applied to the cover 8 , e . g . a touch force . The arrow arranged next to the device 1 indicates , for example , that the device 1 ef ficiently detects a touch force over a huge distance h range .

Figure 2A shows an irradiance distribution on the reflective region 9 of the electromagnetic radiation emitted by the light source 3 on the side of the cover 8 facing the sensor 2 and a multiplication of this irradiance distribution with a reflectance pattern of the cover 8 . This can correspond to the radiance distribution of the cover 8 . In particular, Figure 2A displays the radiance from the cover 8 . For instance , the irradiance of the cover 8 is widely distributed . By multiplying the irradiance of the cover 8 with the reflectance of high and low reflecting material of the cover 8, the radiance from the cover 8 can be obtained. For example, the reflectance of the reflective region 9 of the cover is approximately 90%. The reflectance of the cover 8 outside the reflective region 9 may be less than or equal to 5%, for example.

For example, shown here, the distance between the sensor 2 and the cover 8 is 4 mm. Nonetheless, it is possible that the same or a similar irradiance distribution can be obtained for other distances between the sensor 2 and the cover 8.

On the x-axis and on the y-axis, the position is shown in mm. An area Al shown in Figure 2A corresponds to a largest reflected radiance from the cover 8. The electromagnetic radiation emitted by the light source 3 is absorbed by the cover 8 in an area A3. In an area A2, the reflected radiance is lower than in the area Al and larger than in the area A3.

For instance, the circle comprising the areas Al and A2 in Figure 2A corresponds to the reflective region 9 of the cover 10. This can mean that an irradiance is inhomogeneous within the reflective region 9. In particular, a reflective pattern 10, e.g. a white pattern can be arranged on the cover 8 and form the reflective region 9. Although the reflective pattern 10 shown here comprises the shape of a circle, it is also possible that the reflective pattern 10 comprises any other shape suitable to define a suitable reflective region 9.

In the device 1 measured, analysed or simulated here and in Figures 2B, 3A, 3B, 3C and 3D, the light source 3 is approximately arranged at x = -1.5 mm. The photodiodes 4, 5 are approximately arranged at x = -0.75 mm and/or x = 0.75 mm . For instance , that the light source 3 , the photodiode 4 and/or the further photodiode 5 are arranged at an x-position can mean that the centre of the respective component is arranged at said x-position .

The light source 3 may be a Lambertian light source , e . g . a LED . A field of view or the FWHM of the light source 3 may then be at least approximately 60 ° . For example , shown here , the light source 3 is not tilted . This can mean that most of the electromagnetic radiation emitted by the light source 3 is emitted perpendicular or at least approximately perpendicular to a main extension plane of the sensor 2 .

Figure 2B shows an irradiance distribution of electromagnetic radiation impinging on the chip 13 comprising the photodiode 4 and/or the further photodiode 5 . In particular, the electromagnetic radiation impinging on the chip 13 or on the photodiode 4 and/or the further photodiode 5 is the electromagnetic radiation reflected by the cover 8 . For instance , the electromagnetic radiation is reflected towards the photodiode 4 and/or the further photodiode 5 from the cover 8 shown in Figure 2A. Here , the photodiode 4 is arranged in an area Bl indicating a large irradiance . The photodiode 5 is arranged in area B3 indicating a low or nearly no irradiance . An area B2 comprises an intermediate irradiance .

Figure 3A shows a plot of the contributing reflected radiance distribution shown in Figure 2A. For example , in the plot , an x cross section ( continuous line ) and a y cross section ( dotted line ) of the irradiance at the cover 8 are shown . On the x-axis , the position is shown in pm . The y-axis shows the irradiance Irr in arti ficial units . Figure 3B shows a polar plot of the angular distribution of the electromagnetic radiation emitted by the light source 3. The field of view of the light source 3 indicated here is at least approximately 60°hca and corresponds to the field of view of a Lambertian light source.

Figure 3C shows a graphical view of the signal detected by the photodiode 4 and the further photodiode 5 shown in Figure 2B. For instance, the detected signal is or corresponds to the electromagnetic radiation emitted by the light source 3 and/or reflected by the cover 8 of the device 1. For example, on the y-axis the photo-current PC is shown in artificial units. On the x-axis, the distance h between the cover 8 and the sensor 2 is plotted in mm.

The dotted line is the signal detected by the photodiode 4 which is positioned at approximately x = -0.75 mm. The continuous line is the signal detected by the further photodiode 5, which is positioned at approximately x = 0.75 mm. The light source 3 is arranged around x = -1.5. For example, the light source 3, the photodiode 4 and/or the further photodiode 5 are arranged in line, e.g. at the same y position. This can mean that the further photodiode 5 is arranged further away from the light source 3 than the photodiode 4.

In Figure 3D, the difference between the signals detected by the photodiode 4 and the further photodiode 5 is plotted. The difference between the signals can be referred to as delta signal . Here , the y-axis corresponds to the photo-current PC in arti ficial units and the x-axis corresponds to the distance h in mm between the sensor 2 and the cover 8 .

The dotted line represents the delta signal obtained with the device 1 described in combination with Figure 1 and 2A. The continuous line represents the delta signal for a comparative example of a device without a reflective region being arranged with a lateral of fset to a sensor . Such a comparative example of a device is shown in Figure 14 , for example .

The delta signal of the device 1 according to an exemplary embodiment di f fers form the delta signal of the comparative example in that the delta signal is more linear, in particular for larger distances h between the sensor 2 and the cover 8 . For instance , the delta signal is signi ficant more linear than the delta signal of the comparative example in a distance range above approximately 4 mm . "More linear" can be understood to mean that a di f ference between the delta signal for di f ferent distances h between the sensor 2 and the cover 8 is larger, such that distances h above approximately 4 mm are resolvable or distinguishable .

Figure 4 shows delta signals obtainable with a device 1 according to an exemplary embodiment . On the y-axis the photo-current PC is plotted in arti ficial units . The x-axis shows the distance h in mm between the sensor 2 and the cover 8 . Shown here , the reflective region 9 of the cover 8 is a reflective pattern 10 , e . g . a reflective circle with a diameter of around 2 mm, for example exactly 2 mm . The reflective circle comprises a larger reflectivity than the remaining regions of the cover 8 . The delta signal is plotted for a device 1, wherein a position of the reflective pattern 10, in particular of the reflective circle on the cover 8 is altered. For example, the x position of the reflective region 9 or the reflective pattern 10 is positioned at -3 mm (line L41) , -2.5 mm (line L42) , -2 mm (line L43) , -1.5 mm (line L44) , -1 mm (line L45) , 0 mm (line L46) , 1 mm (line L47) , 2 mm (line L48) and at 2.5 mm (line L49) . Line L410 shows a comparative example, wherein the cover 8 comprises no reflective region, e.g. no reflective pattern 10. In other words, in this case the reflectivity of the cover 8 is homogeneous.

For example, the difference between the delta signal for h = 4 mm and h = 5mm equals 0.035 in case the reflective pattern 10 is arranged at x = -2 mm or at x = - 2.5 mm. In the comparative example, the difference between the delta signal for h = 4mm and h = 5mm is 0.015. This can also be written mathematically as f (4 mm) - f (5 mm) = 0.015.

Figure 5 shows a schematic view of a device according to a further exemplary embodiment. The device 1 shown here differs from the device 1 according to the exemplary embodiment shown in Figure 1 in that a structure 15 is arranged on the side of the cover 8 facing the sensor 2. For instance, the structure 15 is configured to direct impinging electromagnetic radiation away from the sensor 2. In other words, electromagnetic radiation impinging on the structure 15 is not detected by the photodiode 4 and/or the further photodiode 5. For example, the cover 8 is Fresnel structured to form the structure 15. Figure 6 shows a schematic view of a device 1 according to a further exemplary embodiment . The device 1 comprises a cover 8 and a sensor 2 . The device 1 shown here di f fers from the device 1 shown in Figure 1 in that the cover 8 does not comprise a reflective pattern 10 . Instead, the reflective region 9 is formed or defined by the region of the cover 8 on which electromagnetic radiation impinges .

In this case , the light source 3 may be a narrow light source . Thereby, narrow can be understood to mean that a field of view of the light source 3 is at most 30 ° , for example at most 20 ° or at most 15 ° . For instance , the light source 3 is or comprises a laser, for example a VCSEL .

It is also possible , that the light source 3 is tilted . This can mean that a mean direction of the light beam emitted by the light source 3 is tilted with respect to the vertical direction z . For instance , the light source 3 is a top emitter .

The light source 3 can be mounted in a tilted position, for example . Additionally or alternatively, a molded body 6 can be arranged on the light source 3 . For example , the molded body 6 is then configured to tilt the light beam emitted by the light source 3 . For example , the molded body 6 comprises a top surface 6a, which extends at least partially obliquely to the main extension plane of the sensor 2 . Additionally or alternatively, the light beam can be tilted by an optical element 7 , e . g . a lens 7 , wherein the lens 7 is arranged on the light source with a lateral of fset . That the lens 7 is arranged on the light source 3 with a lateral of fset can mean that the lens 7 is not centred on the light source 3 , in particular with regard to the light beam emitted by the light source 3 . The lens may be formed of the molded body 6 , for example . In other words , the molded body 6 can comprise the lens .

A touch force is applied to the cover 8 on the side of the cover 8 facing away from the sensor 2 . For example , shown here , the touch force is applied to the cover 8 laterally to the reflective region 9 . For example , the touch force is applied above the sensor 2 .

In the embodiment of the device 1 shown here , it is not necessary to apply reflective parts , e . g . a reflective pattern onto the cover 8 . Thus , the manufacturing of the cover 8 might be simpli fied compared to the manufacturing of the cover 8 in the embodiment shown in Figure 1 . However, it is also possible to arrange a reflective pattern 10 on the side of the cover 8 facing the light source 3 in the embodiment of the device shown in Figure 6 . In particular, the reflective pattern 10 can then be arranged in or form the reflective region 9 of the cover 8 .

In case no reflective pattern 10 is applied to the cover 8 to form the reflective region 9 of the cover 8 , the cover 8 may be more robust against pollution or ageing .

Figure 7 shows a schematic view of a device 1 according to a further exemplary embodiment . Here , the touch force F is applied to the cover 8 in a region opposing the reflective region 9 , for example . This can mean that the touch force is applied to the cover in a region overlapping with the reflective region 9 . Figure 8A shows an irradiance distribution on the cover 8 from the electromagnetic radiation emitted by the light source 3 on the side of the cover 8 facing the sensor 2. For example, shown here, the distance between the sensor 2 and the cover 8 is 4 mm. Nonetheless, it is possible that the same or a similar irradiance distribution can be obtained for other distances between the sensor 2 and the cover 8.

On the x-axis and on the y-axis, the position is shown in mm. Areas Al and A2 in Figure 8A corresponds to a larger irradiance than area A3. The irradiance in the area Al is larger than in the area A2.

For instance, the bright circle shown in Figure 8A corresponds to the reflective region 9 of the cover 10. In particular, the reflective region 9 can be defined as the region in which, during operation of the light source 3 and/or the device 1, the electromagnetic radiation, which is emitted by the light source 3 impinges on the cover 8.

In the device 1 measured, analysed or simulated here and in Figures 8B, 9A, 9B, 9C and 9D, the light source 3 is approximately arranged at x = -1.5 mm. The photodiodes 4, 5 are approximately arranged at x = -0.75 mm and/or x = 0.75 mm.

The light source 3 causing the irradiation distribution shown in Figure 8A is a tilted narrow light source 3. The field of view or the FWHM of the light source 3 is, for example, approximately 10°. For example, shown here, the light source is tilted -20°. Figure 8B shows an irradiance distribution of the electromagnetic radiation impinging on the chip 13 comprising the photodiode 4 and/or the further photodiode 5 . In particular, the electromagnetic radiation impinging on the chip 13 or on the photodiode 4 and/or the further photodiode 5 is the electromagnetic radiation reflected by the cover 8 . For instance , the electromagnetic radiation is reflected towards the photodiode 4 and/or the further photodiode 5 from the cover 8 shown in Figure 8A.

Figure 9A shows a plot of the irradiance distribution shown in Figure 8A. For example , in the plot , an x cross section ( continuous line ) and a y cross section ( dotted line ) of the irradiance at the cover 8 are shown .

Figure 9B shows a polar plot of the angular distribution of the electromagnetic radiation emitted by the light source 3 . The field of view of the light source 3 indicated here is at least approximately 10 °hca, for example 10 . 6 °hca . In comparison, the angular distribution of a Lambertian light source is also depicted ( dotted line ) .

Figure 9C shows a graphical view of the signal detected by the photodiode 4 and the further photodiode 5 shown in Figure 8B . For instance , the detected signal is or corresponds to the electromagnetic radiation emitted by the light source 3 and/or reflected by the cover 8 of the device 1 . For example , on the y-axis the photo-current PC is shown in arti ficial units . On the x-axis , the distance h between the cover 8 and the sensor 2 is shown in mm .

The dotted line is the signal detected by the photodiode 4 which is positioned at approximately x = - 0 . 75 mm . The continuous line is the signal detected by the further photodiode 5, which is positioned at approximately x = 0.75 mm. The light source 3 is arranged around x = -1.5. The light source 3, the photodiode 4 and/or the further photodiode 5 can be arranged in line, e.g. at the same y position.

Figure 9D shows the delta signal obtained for the device 1 shown in Figure 6 for a configuration as shown in Figures 8A and 8B.

Here, the y-axis corresponds to the photo-current PC in artificial units and the x-axis corresponds to the distance h in mm between the sensor 2 and the cover 8.

The continuous line represents the delta signal obtained with the device 1 described in combination with Figure 6, for example. The dashed line represents the delta signal for a comparative example of a device as shown in Figure 14, for example .

Figure 10 shows a comparison of delta signals obtained for different tilts of the light source 3. The y-axis corresponds to the photo-current PC in artificial units and the x-axis corresponds to the distance h in mm between the sensor 2 and the cover 8. Shown here, the field of view of the light source 3 can be at least approximately 10°hca, for example 10.6°hca. For example, the tilt of the light source 3 is -30° (line L101) , -20° (line L102) , -10° (line L103) , 0° (line L104) , 10° (line L105) , 20° (line L106) , 30° (line L107) and 40° (line L108) . For example, in the shown simulation, the difference between the delta signals for h = 4 mm and h = 5mm is at least approximately 0.036 in case the tilt of the light source 3 is -10° or -20°. In a comparative example (line L109) , in which the light source 3 is a Lambertian light source, e.g. not a narrow light source, and in which the light source is not tilted, the difference between the delta signal for h = 4mm and h = 5mm is 0.015.

Figure 11 shows a comparison of delta signals obtained for different field of views of the light source 3. In the examples depicted in Figure 11, the tilt of the light source 3 is approximately -20° or equal to -20°. The field of view of the light source 3 can be at least approximately 7°hca, for example 6.7°hca (line Llll) , 10°hca, for example 10.6°hca (line 112) , 15°hca (line L113) or 29.5°hca (line L114) . Line L115 corresponds to line L109 shown in Figure 10.

Figure 12 shows a schematic view of a sensor 2 of a device 1 according to an exemplary embodiment. For example, Figure 12 shows a detailed view of the device 1 shown in Figures 6 or 7. The device 1 can comprise an optical element 7. For example, the optical element 7 is configured to tilt the light beam emitted by the light source 3. The device 1 comprises a molded body 6. For example, the molded body 6 can comprise a top surface 6a, i.e. on the side of the molded body 6 facing the cover 8. For instance, the top surface 6a of the molded body 6 extends at least partially obliquely to the main extension plane of the sensor 2. The light beam emitted by the light source 3 may be tilted by the molded body 6. This can mean that the molded body 6 comprises or forms the optical element 7. In other words, the optical element 7 can be formed of the material of the molded body 6 or can be part of the molded body 6.

The top surface 6a of the molded body 6 can extend obliquely above the light source 3. In particular, the top surface 6a of the molded body 6 extends obliquely to a top surface of the light source 3 , for example to the side of the light source 3 at which electromagnetic radiation is coupled out . For example , the top surface 6a of the molded body 6 is formed obliquely by increasing the thickness of the molded body 6 on top of the light source 3 in a direction away from the photodiode 4 .

Figure 13 shows a schematic view of a sensor 2 of a device 1 according to an exemplary embodiment . The device 1 comprises the optical element 7 . In particular, the optical element 7 can be a lens 7 . The lens 7 is arranged on the light source 3 . This can mean that the lens 7 and the light source 3 overlap at least partially along the vertical direction z . The lens 7 may be a convex lens . A center of the lens 7 does not overlap with a center of the light beam emitted by the light source 3 . Thus , for example , the lens 7 tilts the light beam which is emitted by the light source 3 .

Figure 14 shows a schematic view of a device 1 according to a comparative example . In comparison to the embodiments shown in Figures 1 and 5 to 7 , the cover 8 in the comparative example does not comprise a reflective region 9 on the side of the cover 8 facing the sensor 2 , which is arranged with a lateral of fset to the sensor 2 . Instead, the reflective region 9 is arranged above the photodiode 4 and/or the further photodiode 5 . Further, the cover 8 shown here might not comprise a di f fuse reflectance . This means , it is possible that the electromagnetic radiation emitted by the light source 3 impinges on the photodiode 4 after total reflection on the cover 8 . The arrow shown next to the device 1 indicates that an ef ficient touch force F measurement is only possible within a small distance h range . Figures 15A and 15B show schematic irradiance distributions of a device according to a comparative example . The irradiance distributions shown here di f fer from the irradiance distributions shown in Figures 8A and 8B in that the light source 3 is not a narrow light source . Instead, shown here , the light source 3 may comprise Lambertian characteristics . For example , the device of Figures 15A and 15B di f fers from the device 1 of Figures 2A and 2B in that the cover 8 does not comprise a reflective region 9 formed by a reflective patter 10 .

Figures 16A, 16B, 16C and 16D show graphs similar to the graphs 3A, 3B, 3C and 3D for a device according to the comparative example shown in Figure 14 .

The invention described herein is not limited by the description given with reference to the embodiments . Rather, the invention encompasses any novel feature and any combination of features , including in particular any combination of features in the claims , even i f this feature or this combination is not itsel f explicitly indicated in the claims or embodiments .

This patent application claims priority from German patent application 10 2024 101 306 . 0 , the disclosure content of which is hereby incorporated by reference . References

1 device

2 sensor

3 light source

4 photodiode

5 further photodiode

6 molded body

6a top surface

7 optical element

8 cover

9 reflective region

10 reflective pattern

11 barrier

12 signal processing unit

13 chip

14 carrier

15 structure x, y lateral directions z vertical direction

F force

Al area Al

A2 area A2

A3 area A3

Bl area Bl

B2 area B2

B3 area B3

Claims

1. A device (1) , comprising

- a sensor (2) with

- a light source (3) , configured to emit electromagnetic radiation,

- a photodiode (4) , configured to detect electromagnetic radiation, and

- a cover (8) , wherein

- the cover (8) comprises a reflective region (9) on the side of the cover (8) facing the sensor (2) , and

- the reflective region (9) is arranged with a lateral offset to the sensor ( 2 ) .

2. The device (1) according to the previous claim, wherein the reflective region (9) does not overlap with the photodiode (4) along a vertical direction (z) .

3. The device (1) according to one of the previous claims, wherein the reflective region (9) protrudes the sensor (2) on a side facing away from the photodiode (4) .

4. The device (1) according to one of the previous claims, wherein the sensor (2) comprises a further photodiode (5) , and a distance between the photodiode (4) and the light source (3) is smaller than a distance between the further photodiode (5) and the light source (3) .

5. The device (1) according to one of the previous claims, wherein a distance between the cover (8) and the sensor (2) is larger than a distance between the photodiode (4) and the light source (3) .

6. The device (1) according to one of the previous claims, wherein the cover (8) comprises a higher reflectance in the reflective region (9) than outside the reflective region (9) .

7. The device (1) according to the previous claim, wherein a reflective pattern (10) is arranged in the reflective region

8. The device (1) according to one of the previous claims, wherein

- a structure (15) is arranged on the side of the cover (8) facing the sensor (2) , and

- the structure (15) is configured to direct impinging electromagnetic radiation away from the sensor (2) .

9. The device (1) according to one of the previous claims, wherein a field of view of the light source (3) is at most 20° .

10. The device (1) according to one of the previous claims wherein a mean direction of the light beam emitted by the light source (3) is tilted with respect to the vertical direction ( z ) .

11. The device (1) according to the previous claim, wherein a molded body (6) is arranged on the light source (3) , the molded body (6) comprising a top surface, which extends at least partially obliquely to a main extension plane of the sensor (2) , and the light beam is tilted by the molded body (6) .

12. The device (1) according to claim 10, further comprising a lens (7) , wherein the lens (7) is arranged on the light source (3) , and a center of the lens (7) does not overlap with a center of the light beam emitted by the light source (3) .

13. The device (1) according to one of the previous claims, wherein a barrier (11) is arranged between the light source (3) and the photodiode (4) , and the barrier (11) is non- transmissive for the electromagnetic radiation emitted by the light source (3) .

14. The device (1) according to one of the previous claims, wherein the sensor (2) comprises an integrated signal processing unit (12) .

15. A method for operating a device (1) according to one of the claims 1 to 14, wherein

- the light source (3) of the sensor (2) emits electromagnetic radiation,

- the electromagnetic radiation is reflected by the reflective region (9) of the cover (8) , and

- the reflected electromagnetic radiation is detected by the photodiode ( 4 ) .

16. The method for operating a device (1) according to the previous claim, wherein the device (1) is configured to detect a touch force being applied to the cover (8) .