Method for activating a high-power mode of a sensor device, human machine interface, system, computer program and computer-readable storage medium

Abstract

A method for activating a high-power mode of a sensor device being configured to provide a displacement information and / or a velocity information is specified, comprising: - providing measurement information while the sensor device is in a low-power mode, and - activating the high-power mode dependent on the measurement information, wherein - the measurement information is characteristic of whether an object is in proximity to the sensor device, and - in the high-power mode the sensor device (1) is configured to provide the displacement information and / or a velocity information that is characteristic of an optical measurement. Further, a human machine interface, a system, a computer program and a computer-readable storage medium are specified.

Description

[0001] Description

[0002] METHOD FOR ACTIVATING A HIGH-POWER MODE OF A SENSOR DEVICE ,

[0003] HUMAN MACHINE INTERFACE , SYSTEM, COMPUTER PROGRAM AND

[0004] COMPUTER-READABLE STORAGE MEDIUM

[0005] The present application relates to a method for activating a high-power mode of a sensor device being configured to provide a displacement information and / or velocity information, a human machine interface , a system, a computer program and a computer-readable storage medium .

[0006] Typically, in sel f-mixing interference , SMI , displacement information and / or velocity measurements , a user ' s interactions are randomly timed . Therefore , a typical SMI sensor needs to scan continuously to correctly detect any possible displacement information and / or velocity . I f the sensor is powered at a high frequency in order not to miss any displacement information and / or velocity, the power consumption by the typical SMI sensor is comparatively high .

[0007] It is an obj ective to provide a method for correctly detecting a displacement and / or a velocity with a reduced power consumption . It is a further obj ective to provide a human machine interface , a system and a computer program which can perform such a method . Furthermore , a computer- readable storage medium with such a computer program is to be provided .

[0008] These obj ectives are achieved by the method and the subj ect matter of the independent patent claims . Advantageous embodiments , implementations and further developments are the subj ect matter of the respective dependent patent claims . The method for activating a high-power mode of a sensor device being configured to provide a displacement information and / or velocity information is provided .

[0009] The sensor device is , for example , comprised in a system, wherein the sensor device is particularly configured to provide a displacement information and / or velocity information of a part of the system . Exemplarily, the system comprises a housing in which the sensor device is included . The sensor device is particularly configured to provide a displacement information and / or velocity information of the housing . Exemplarily, the housing is deformed when a user applies a force to the housing, e . g . with a hand, particularly a finger, of the user . The deformation is exemplarily dependent on the force of the user applied to the housing . The displacement information and / or velocity information is exemplarily dependent on the deformation .

[0010] For providing the displacement information and / or velocity information, the sensor device is , for example , operated in the high-power mode . The high-power mode is exemplarily characteristic of a comparatively high power consumption . The comparatively high power consumption is , for example , at least 1 mW, exemplarily at least a few mW .

[0011] According to at least one embodiment of the method, measurement information is provided while the sensor device is in a low-power mode . As a default , the sensor device is operated in the low-power mode . The low-power mode is exemplarily characteristic of a comparatively low power consumption . The comparatively high power consumption is about 300pW, exemplarily hundreds of tens of pW . Exemplarily, a power consumption by the sensor device in the low-power mode is at least 10% and / or at least 50% smaller than an power consumption by the sensor device in the high- power mode .

[0012] The sensor device exemplarily comprises at least one optical device , which is configured to emit electromagnetic radiation and / or to receive electromagnetic radiation in the low-power mode and in the high-power mode . The measurement information is , for example , dependent on the emitted and / or received electromagnetic radiation of the at least one optical device of the sensor device in the low-power mode .

[0013] The sensor device is exemplarily configured to provide the measurement information to a control device . In particular, the sensor device is configured to provide the measurement information by acquiring and / or measuring the measurement information and subsequently providing the measurement information to the control device . The control device is , for example , comprised by the system . Exemplarily, the control device is part of the sensor device , or the control device is an external device not being part of the sensor device . The control device comprises , for example , an integrated circuit and is configured to process the measurement information .

[0014] According to at least one embodiment of the method, the high- power mode is activated dependent on the measurement information . Exemplarily, the measurement information is characteristic of at least one measurement value . I f the measurement value is smaller and / or higher than a predetermined threshold value and / or i f the measurement values are characteristic of a slope , being smaller and / or higher than a further predetermined threshold value , the high-power mode is activated .

[0015] According to at least one embodiment of the method, the measurement information is characteristic of whether an obj ect is in proximity to the sensor device . The obj ect is , for example , the finger of the user . ' In proximity to the sensor device ' means here and in the following that the obj ect has a distance to the sensor device , in particular the system, of at most 10 cm, at most 5 cm and / or at most 1 cm . Alternatively or additionally, ' in proximity to the sensor device ' means in particular that the obj ect is in direct contact to the housing .

[0016] I f the measurement information is characteristic of the obj ect being in proximity to the sensor device , the high- power mode is activated . I f the measurement information is characteristic of the obj ect not being in proximity to the sensor device , the sensor device is further operated in the low-power mode .

[0017] According to at least one embodiment of the method, in the high-power mode the sensor device is configured to provide the displacement information and / or the velocity information that is characteristic of an optical measurement . The sensor device is exemplarily configured to provide the displacement information and / or the velocity information to a control device . Exemplarily, the displacement information and / or the velocity information is acquired by the optical measurement of the sensor device . In particular, the sensor device is configured to acquire and / or to measure the displacement information and / or the velocity information optically and subsequently provide the displacement information and / or the velocity information to the control device . Exemplarily, the integrated circuit of the control device is configured to process the displacement information and / or the velocity information .

[0018] The displacement information and / or the velocity information is , for example , dependent on the emitted and / or received electromagnetic radiation of the at least one optical device of the sensor device in the high-power mode . In particular, the measurement information and / or the displacement information and / or the velocity information is / are characteristic of a measurement signal of the electromagnetic radiation .

[0019] An idea is , inter alia, to operate the sensor device in the low-power mode and, only when the measurement information indicates that an obj ect is in proximity to the sensor device , the sensor device is operated in the high-power mode to advantageously provide the displacement information and / or the velocity information .

[0020] Advantageously, only when the obj ect , exemplarily the finger, approaches or contact is detected, the sensor device works in active full mode for displacement detection and / o for velocity detection . As the approach is detected in the low- power mode , this advantageously saves power consumption without missing any displacement and / or velocity . In particular, no further components and complex arrangements are required advantageously .

[0021] According to at least one embodiment of the method, the low- power mode is configured to consume less power than the high- power mode . Exemplarily, the sensor device is operated as a default in the low-power mode for a first time interval and the sensor device is operated when activated in the high- power mode for a second time interval . In particular, the first time interval is larger than the second time interval by at least one order of magnitude . This advantageously reduces a power consumption by the sensor device .

[0022] According to at least one embodiment of the method, the sensor device comprises at least one laser device . The laser device is in particular configured to emit laser light and / or to receive electromagnetic radiation . The laser light is in particular monochromatic and coherent laser light .

[0023] Exemplarily, the laser device is a Vertical-Cavity Surface- Emitting Laser, VCSEL for short . The VCSEL comprises a semiconductor layer sequence within a resonator configured to produce and emit the laser light as well as receive reflected laser light . The laser light is in particular emitted perpendicular to main extension planes of the layers of the semiconductor layer sequence .

[0024] The laser device is operated in a pulsed mode , wherein the electromagnetic radiation is emitted in a pulsed form, or a continuous mode , wherein the electromagnetic radiation is emitted in a continuous form .

[0025] The high-power mode is exemplarily characteristic of a high frequency or even continuous with which the laser device is powered . The high frequency is , for example , a few kHz . Exemplarily, the high-power mode is exemplarily characteristic of a high power consumption by the laser device , e . g . , a few mW . The low-power mode is exemplarily characteristic of a low frequency with which the laser device is powered . The low frequency can be a few tenth of Hz . Exemplarily, the low-power mode is exemplarily characteristic of a low power consumption by the laser device , e . g . , a few tenth of uW .

[0026] The power consumption by the sensor device is in particular mainly dependent on a power consumption by the laser device . 'Mainly' means here that the power consumption by the laser device accounts for at least 80 % of the power consumption by the sensor device when in the high-power mode . Exemplarily, i f the sensor device is activated, the laser device is activated to be operated in the high-power mode .

[0027] According to at least one embodiment of the method, the device is a sel f-mixing interference sensor device . Exemplarily, when the sensor device is operated in the high- power mode , an interference pattern is generated when emitted electromagnetic radiation from the laser device is reflected back into the same laser device . Particularly, the laser device serves both as a source of the electromagnetic radiation and a detector of the reflected electromagnetic radiation .

[0028] When the electromagnetic radiation of the laser device is reflected by a surface , e . g . a surface of the housing, a portion of the electromagnetic radiation is reflected back into the laser device . The reflected electromagnetic radiation interferes with the originally emitted electromagnetic radiation . An interference pattern is generated by this interference , wherein the displacement information and / or the velocity information is particularly dependent on the interference pattern, or the displacement information and / or the velocity information is the interference pattern, in particular when the sensor device is operated in the high-power mode .

[0029] According to at least one embodiment of the method, the sel fmixing interference sensor device is configured to provide a sel f-mixing interference signal . For example , the displacement information and / or the velocity information comprises the sel f-mixing interference signal when the sensor device is operated in the high-power mode . The sel f-mixing interference signal can correspond to the interference pattern described herein above .

[0030] According to at least one embodiment of the method, the measurement information comprises the sel f-mixing interference signal . Exemplarily, the measurement information comprises the sel f-mixing interference signal when the sensor device is operated in the low-power mode . Exemplarily, the measurement information is the sel f-mixing interference signal .

[0031] The sel f-mixing interference signal is , for example , characteristic of a voltage signal or a current signal . The voltage signal or the current signal is for example provided to the control device . The control device is exemplarily configured to convert the voltage signal or the current signal , which is an analog signal , to a digital signal using an analog-to-digital converter, ADC for short . The digital signal is , for example , characteristic of ADC counts , which represent the analog signal after conversion . The ADC counts are unitless values and in particular proportional to the voltage signal or the current signal . If the self-mixing interference sensor device, in particular the laser device, is operated in the high-power mode, the self-mixing interference signal is usable for the displacement information and / or the velocity information, as the self-mixing interference signal is comparatively accurate. 'Comparatively accurate' means that displacements are of at least half-wavelength.

[0032] If the self-mixing interference sensor device, in particular the laser device, is operated in the low-power mode, the self-mixing interference signal is not usable for the displacement information and / or the velocity information, as the self-mixing interference signal is too inaccurate. But the self-mixing interference signal of the low-power mode is advantageously usable for detecting whether an object is in proximity to the sensor device.

[0033] If the self-mixing interference signal, being in particular characteristic of an ADC count, is characteristic of a change that is higher than a first predetermined threshold, the object is detected to be in proximity to the sensor device, such that the sensor device is activated to the high-power mode. Exemplarily, the first predetermined threshold is characteristic of a first predetermined ADC count.

[0034] If the self-mixing interference signal, being in particular characteristic of an ADC count, is characteristic of a change that is smaller than the first predetermined threshold, the object is detected to be not in proximity to the sensor device, such that the sensor device is continued to be operated in the low-power mode. According to at least one embodiment of the method, the sensor device further comprises at least one photo detector device . The photo detector device is , for example , arranged spaced apart from the laser device . The photo detector device is configured to receive electromagnetic radiation and further configured to convert the electromagnetic radiation into an electrical signal , e . g . a photocurrent .

[0035] The photo detector device comprises , for example , at least one photo diode . The photo detector device can comprise a plurality of photo diodes . The photo diodes are , for example , arranged along an array and / or along rows and columns . The photo diodes are , exemplarily, arranged on grid points of a grid, in particular a polygonal grid .

[0036] According to at least one embodiment of the method, the at least one photo detector device is configured to provide a photo detector signal . The photo detector signal is , for example , characteristic of the generated photocurrent .

[0037] The electromagnetic radiation which is emitted from the laser device and which is reflected by the surface can reach the photo detector device . The generated photocurrent is in particular characteristic of the emitted electromagnetic radiation as well as the reflected emitted electromagnetic radiation, in particular an interference thereof , which is induced by the displacement of the surface . In particular, the interference between the emitted and reflected electromagnetic radiation generates variations in the photo detector signal .

[0038] I f the sel f-mixing interference sensor device , in particular the laser device , is operated in the high-power mode , the sel f-mixing interference signal comprises additionally or alternatively the photo detector signal .

[0039] According to at least one embodiment of the method, the measurement information comprises the photo detector signal . I f the sel f-mixing interference sensor device , in particular the laser device , is operated in the low-power mode , the sel f-mixing interference signal comprises the photo detector signal .

[0040] According to at least one embodiment of the method, the photo detector signal is characteristic of ambient light . In particular, the photo detector device is configured to receive electromagnetic radiation from the laser device as well as electromagnetic radiation from an environment of the sensor device , being the ambient light .

[0041] Advantageously, no further devices and no complex components are required since the laser device and the photo detector device are already available in the sensor device .

[0042] According to at least one embodiment of the method, the photo detector signal is dependent on whether an obj ect is in proximity to the sensor device . I f the obj ect is in proximity to the sel f-mixing interference device , the obj ect leads to a shading of the photo detector device , thus reducing the produced photo detector signal . The photo detector signal , which is an analog signal , can be converted, e . g . by the control device , to a digital signal using the analog-to- digital converter .

[0043] I f the photo detector signal is characteristic of a photocurrent being smaller than a second predetermined threshold and / or characteristic of a change in the photocurrent being smaller than a second predetermined threshold, the obj ect is detected to be in proximity to the sensor device , such that the sensor device is activated to the high-power mode . Exemplarily, the second predetermined threshold is characteristic of a predetermined photocurrent , e . g . a second predetermined ADC count . The predetermined photocurrent can be a dynamic photocurrent , which is determined to be at least 5% smaller than the photocurrent corresponding to a surrounding ambient light of the sensor device .

[0044] I f the photo detector signal is characteristic of the photocurrent being higher, and / or characteristic of a change in the photocurrent being higher than the second predetermined threshold, the obj ect is detected to be not in proximity to the sensor device , such that the sensor device is further operated in the low-power mode .

[0045] According to at least one embodiment of the method, the photo detector signal is characteristic of electromagnetic radiation received from the at least one laser device . Exemplarily, the electromagnetic radiation of the laser device can be further reflected by the obj ect . In particular, due to the further reflection at the obj ect , an amount of reflected electromagnetic radiation increases at the photo detector device , resulting in an increased photocurrent . Exemplarily, the electromagnetic radiation of the laser device is transmitted through the housing .

[0046] According to at least one embodiment of the method, the photo detector signal is dependent on whether an obj ect is in proximity to the sensor device . I f the photo detector signal is characteristic of a photocurrent being higher, and / or characteristic of a change in the photocurrent being higher than a third predetermined threshold, the obj ect is detected to be in proximity to the sensor device , such that the sensor device is activated to the high-power mode . Exemplarily, the third predetermined threshold is characteristic of a predetermined photocurrent , e . g . a third predetermined ADC count .

[0047] I f the photo detector signal is characteristic of the photocurrent being smaller and / or characteristic of a change in the photocurrent being smaller than the third predetermined threshold, the obj ect is detected to be not in proximity to the sensor device , such that the sensor device is further operated in the low-power mode .

[0048] According to at least one embodiment of the method, the sensor device further comprises at least one temperature sensor device . The temperature sensor device is arranged spaced apart from the laser device and the photo detector device . The temperature sensor can detect temperature change cause by proximity or contact of the finger .

[0049] According to at least one embodiment of the method, the at least one temperature sensor device is configured to provide a temperature signal .

[0050] According to at least one embodiment of the method, the measurement information comprises the temperature signal . According to at least one embodiment of the method, the temperature signal is characteristic of a temperature in proximity to the sensor device .

[0051] According to at least one embodiment of the method, the temperature signal is dependent on whether an obj ect is in proximity to the sensor device .

[0052] I f the temperature signal is characteristic of a temperature being higher, and / or characteristic of a change in the temperature being higher than a fourth predetermined threshold, the obj ect is detected to be in proximity to the sensor device , such that the sensor device is activated to the high-power mode . Exemplarily, the fourth predetermined threshold is characteristic of a dynamic temperature . The dynamic temperature is , for example , determined to be at least 5% higher than a surrounding temperature of the sensor device .

[0053] I f the temperature signal is characteristic of the temperature being smaller, and / or characteristic of a change in the temperature being smaller than the fourth predetermined threshold, the obj ect is detected to be not in proximity to the sensor device , such that the sensor device is further operated in the low-power mode .

[0054] Furthermore , a human machine interface for activating a high- power mode of a sensor device being configured to provide a displacement information and / or the velocity information is provided . The human machine interface can be comprised by the system as described herein above . The human machine interface is configured to perform the method described herein above . All features of the embodiment disclosed in connection with the method are therefore also disclosed in connection with the human machine interface and vice versa .

[0055] According to at least one embodiment , the human machine interface comprises a sensor device .

[0056] Further, the human machine interface is configured to perform the method described herein above .

[0057] The human machine interface is , for example , comprised by a wearable device , e . g . a watch or a headphone . In particular, the system is a wearable device or any electronic and / or mechanical system which can be controlled by the human machine interface .

[0058] Moreover, a system is provided, which is described particularly herein above . The system comprises the human machine interface as described herein above .

[0059] Furthermore , a computer program is provided, comprising instructions which, when the computer program is executed by a computer, cause the computer program to perform the method described herein .

[0060] Furthermore , a computer-readable storage medium is provided, on which the computer program described herein is stored .

[0061] In the following, the method and the human machine interface are explained in more detail with reference to the figures by means of exemplary embodiments . Figure 1 shows a flow chart diagram of an exemplary embodiment of the method .

[0062] Figures 2 and 3 each show a sensor device being used in the method according to an exemplary embodiment .

[0063] Figure 4 shows a human machine interface of a system being used in the method according to an exemplary embodiment .

[0064] Figures 5 , 6 , 7 and 8 each show an exemplary diagram of signals of a sensor device being used in the method according to an exemplary embodiment .

[0065] Elements that are identical , similar or have the same ef fect are given the same reference signs in the Figures . The Figures and the proportions of the elements shown in the Figures are not to be regarded as true to scale . Rather, individual elements can be shown exaggeratedly large for better representability and / or for better comprehensibility .

[0066] In the flow chart diagram of the method, in a method stage S I , a measurement information of a sensor device 1 is provided while the sensor device 1 is in a low-power mode . In particular, the measurement information is provided by the sensor device 1 to a control device . The control device can be part of the sensor device 1 or the control device can be an external device , being spaced apart from the sensor device 1 .

[0067] In method stage S2 , the high-power mode of the sensor device 1 is activated dependent on the measurement information . In particular, the measurement information is compared to a predetermined threshold in the control device. If the measurement information is smaller or higher than the predetermined threshold, the high-power mode is activated.

[0068] The measurement information is characteristic of whether an object is in proximity to the sensor device 1. The object is in particular a finger of a user of the sensor device 1. If the finger approaches the sensor device 1, this can be reflected in the measurement information, while the sensor device 1 is in the low-power mode. Dependent on the measurement information, e.g. if the predetermined threshold is exceeded, the sensor device 1 is activated to the high- power mode.

[0069] In the high-power mode the sensor device 1 is configured to provide the displacement information and / or the velocity information that is characteristic of an optical measurement. The displacement information is, for example, characteristic of a displacement of a part of a system 5 in which the sensor device 1 is incorporated.

[0070] If the sensor device 1 is operated in the low-power mode, the sensor device 1 can miss a part of or the whole displacement. Exemplarily, the sensor device 1 is operated in the low-power mode in a low frequency duty cycle. In particular, to correctly detect the displacement, the sensor device 1 is powered in the high-power mode continuously or at a high frequency, e.g. 23 kHz.

[0071] In the low-power mode, a power consumption is e.g. at most 50 mW or at most 10 mW, which is at least an order of magnitude smaller than a targeted power consumption in the high-power mode, e.g. at least 100 pW or at least 250 pW. To save power, the sensor device 1 is advantageously in this low-power mode . Only when the finger is in proximity to the sensor device 1 , the sensor device 1 is activated to the high-power mode .

[0072] The sensor device 1 according to Figure 2 comprises a laser device 2 and a photo detector device 3 . The laser device 2 is spaced apart from the photo detector device 3 . In particular, the laser device 2 is a VCSEL and the photo detector device 3 is a photo diode . Exemplarily, the sensor device 1 is a sel fmixing interference sensor device 1 . The sel f-mixing interference sensor device 1 , in particular the laser device 2 or the laser device 2 and the photo detector device 3 , is configured to provide a sel f-mixing interference signal . The displacement information is particularly characteristic of the sel f-mixing interference signal when the sensor device 1 , in particular the laser device 2 , is in the high-power mode . The sel f-mixing interference sensor device 1 , in particular the laser device 2 or the laser device 2 and the photo detector device 3 , is configured to provide the measurement information when the sensor device 1 , in particular the laser device 2 , is in the low-power mode .

[0073] The sensor device of Figure 3 comprises , in contrast to Figure 2 , a plurality of photo diodes being arranged along rows and columns in a 3 x 4 pixel matrix arrangement .

[0074] The sensor device 1 according to Figures 2 or 3 is comprised in a human machine interface 4 of Figure 4 , which is particularly comprised by a system 5 . The system 5 is a wearable , in particular a headphone , in particular an earphone . The system 5 comprises a housing 6 with a stem 7 , wherein the sensor device 1 is comprised in the stem 7 of the housing 6 . The human machine interface 4 comprises the sensor device 1 , which is configured to translate a motion of a finger of a user into an action for using the headphone . Exemplarily, the action is performed dependent on a displacement of the stem 7 initiated by the finger .

[0075] The diagram according to Figure 5 shows on the y-axis values yi being characteristic of values of an ambient light of the sensor device 1 in arbitrary units . The x-axis shows a time in seconds . The two channels correspond to the pixels Pi and Pn of the photo detector device 3 as illustrated in Figure 3 .

[0076] The photo detector device 3 is configured to provide a photo detector signal , wherein the photo detector signal is characteristic of the ambient light . I f the sensor device 1 is in the low-power mode , the measurement information comprises the photo detector signal . In particular, the channels shown in Figure 5 correspond to the photo detector signals of the pixels Pi and Pn of the photo detector device

[0077] 3 . The photo detector signal is dependent on whether an obj ect is in proximity to the sensor device 1 .

[0078] I f the obj ect , in particular the finger, approaches the sensor device 1 and / or contacts the housing 6 shown in Figure

[0079] 4 , the ambient light is reduced as marked by the two arrow regions in Figure 5 . I f the measurement information is characteristic of such a reduction in ambient light , the approach and / or the contact is detected and the sensor device 1 is activated to the high-power mode for accurately providing the displacement information .

[0080] In particular, a second predetermined threshold is defined to exclude that the reduction in ambient light is not caused by the approach of the finger and / or the contact of the finger . Advantageously, the laser device 2 does not need to be powered for detecting the obj ect , in particular the finger . This can further reduce power consumption .

[0081] The diagram according to Figure 6 shows on the y-axis values y2being characteristic of values of reflected electromagnetic radiation of the sensor device 1 in arbitrary units . The x-axis shows a time in seconds . The two channels correspond to the pixels Pi and Pu of the photo detector device 3 as illustrated in Figure 3 .

[0082] Electromagnetic radiation of the laser device 2 can be reflected by the housing 6 as shown in Figure 4 , when the sensor device 1 is in the low-power mode . Additionally, the electromagnetic radiation of the laser device 2 can be transmitted through the housing 6 and can be reflected by the obj ect , in particular the finger, when the sensor device 1 is in the low-power mode . This means that the photo detector signal is characteristic of the electromagnetic radiation being reflected by the housing 6 as well as the electromagnetic radiation being further reflected by the obj ect , in particular the finger . In particular, the upper two channels shown in Figure 6 correspond to the photo detector signals of the pixels Pi and Pn of the photo detector device 3 . The lower channel corresponds to a di f ferential signal of pixels Pi and Pn . The photo detector signal is dependent on whether an obj ect is in proximity to the sensor device .

[0083] I f the obj ect , in particular the finger, approaches the sensor device 1 and / or contacts the housing 6 shown in Figure 4 , due to the further reflection at the obj ect , an amount of reflected electromagnetic radiation increases at the photo detector device 3 , resulting in an increased photocurrent , as marked by the two arrow regions in Figure 6 .

[0084] I f the measurement information is characteristic of such an increase in the photocurrent , the approach and / or the contact is detected and the sensor device 1 is activated to the high- power mode for accurately providing the displacement information .

[0085] In particular, a second predetermined threshold is defined to exclude that the reduction in ambient light is not caused by the approach of the finger and / or the contact of the finger . Advantageously, the laser device 2 does not need to be powered for detecting the obj ect , in particular the finger . This can further reduce power consumption .

[0086] The laser device 2 can be powered at a low frequency in the low-power mode to detect the approach of the finger and / or the contact of the finger . This advantageously consumes very little power .

[0087] The diagram according to Figure 7 shows on the y-axis values y3being characteristic of values of a sel f-mixing interference signal of the sensor device 1 in arbitrary units while being in the low-power mode . The x-axis shows a time in seconds . The two channels correspond to the pixels Pi and Pn of the photo detector device 3 as illustrated in Figure 3 .

[0088] The laser device 2 is configured to provide the sel f-mixing interference signal , also when powered in the low-power mode . I f the sensor device 1 is in the low-power mode , the measurement information comprises the sel f-mixing interference signal . In particular, the channels shown in Figure 5 correspond to the sel f-mixing interference signal of the pixels Pi and Pu of the photo detector device 3 and the laser device 2 . The sel f-mixing interference is dependent on whether an obj ect is in proximity to the sensor device 1 .

[0089] I f the obj ect , in particular the finger, approaches the sensor device 1 and / or contacts the housing 6 shown in Figure 4 , the sel f-mixing interference signal is increased as marked by the two arrow regions in Figure 5 . I f the measurement information is characteristic of such an increase of the sel f-mixing interference signal , the approach and / or the contact is detected and the sensor device 1 is activated to the high-power mode for accurately providing the displacement information . Exemplarily, the sel f-mixing interference is increased during the approach or the contact as the temperature of the sensor device 1 increases .

[0090] As the approach and / or the contact can generate the sel fmixing interference signal , which has a very low frequency, the laser device 2 can be operated in the low-power mode at a low frequency to detect the approach and / or the contact . This advantageously consumes very little power . Further advantageously, the obj ect , in particular the finger, which approaches and / or contacts does not need to be facing an emitting direction of the laser device 2 .

[0091] The diagram according to Figure 8 shows on the y-axis a count of in particular ADC counts as described herein above . The x- axis shows a time in seconds . The upper two channels correspond to the pixels Pi and Pu of the photo detector device 3 as described in Figure 5 , and the lower two channels correspond to the pixels Pi and Pn of the photo detector device 3 as described in Figure 6 . Both detection methods can be used in combination in order to increase reliability .

[0092] In particular, the detection methods described in connection with Figures 5 , 6 and 7 can be combined to detect the approach and / or the contact . For example , the combination of the processes according to Figures 5 and 6 , according to Figures 5 and 7 , according to Figures 6 and 7 and / or according to Figures 5 , 6 and 7 can detect the approach and / or the contact , improving reliability .

[0093] In particular, the processes according to Figures 6 and 7 can be combined since both signals are simultaneously detected by the photo detector device 3 .

[0094] In general , when the sensor device 1 detects a change in electromagnetic radiation, the sensor device 1 can advantageously trigger the displacement measurement .

[0095] This patent application claims the priority of the German patent application 102024101126 . 2 , the disclosure of which is hereby incorporated by reference .

[0096] The features and exemplary embodiments described in connection with the figures can be combined with each other according to further exemplary embodiments , even i f not all combinations are explicitly described . Furthermore , the exemplary embodiments described in connection with the figures can alternatively or additionally have further features according to the description in the general part .

[0097] The invention is not limited to these exemplary embodiments by the description based on the exemplary embodiments . Rather, the invention encompasses any new feature as well as any combination of features , which in particular includes any combination of features in the patent claims , even i f this feature or combination itsel f is not explicitly stated in the patent claims or exemplary embodiments .

[0098] References

[0099] 1 sensor device

[0100] 2 laser device 3 photo detector device

[0101] 4 human machine interface

[0102] 5 system

[0103] 6 housing

[0104] 7 stem

[0105] S1..S2 method stages

[0106] P0. . Pl 1 pixel

Claims

Claims1. Method for activating a high-power mode of a sensor device (1) being configured to provide a displacement information and / or a velocity information, comprising:- providing measurement information while the sensor device(1) is in a low-power mode, and- activating the high-power mode dependent on the measurement information, wherein- the measurement information is characteristic of whether an object is in proximity to the sensor device (1) , and- in the high-power mode the sensor device (1) is configured to provide the displacement information and / or a velocity information that is characteristic of an optical measurement.

2. Method according to claim 1, wherein- the low-power mode is configured to consume less power than the high-power mode.

3. Method according to one of claims 1 and 2, wherein- the sensor device (1) comprises at least one laser device(2) .

4. Method according to one of claims 1 to 3, wherein- the sensor device (1) is a self-mixing interference sensor device ( 1 ) , and- the self-mixing interference sensor device (1) is configured to provide a self-mixing interference signal.

5. Method according to claim 4, wherein- the measurement information comprises the self-mixing interference signal.

6. Method according to one of claims 3 to 5, wherein- the sensor device (1) further comprises at least one photo detector device (3) , and- the at least one photo detector device (3) is configured to provide a photo detector signal.

7. Method according to claim 6, wherein- the measurement information comprises the photo detector signal .

8. Method according to claim 7, wherein- the photo detector signal is characteristic of ambient light, and- the photo detector signal is dependent on whether an object is in proximity to the sensor device (1) .

9. Method according to one of claims 7 or 8, wherein- the photo detector signal is characteristic of electromagnetic radiation received from the at least one laser device (2) , and- the photo detector signal is dependent on whether an object is in proximity to the sensor device (1) .

10. Method according to one of claims 1 to 9, wherein- the sensor device (1) further comprises at least one temperature sensor device, and- the at least one temperature sensor device is configured to provide a temperature signal.

11. Method according to claim 10, wherein- the measurement information comprises the temperature signal .

12. Method according to one of claims 10 or 11, wherein- the temperature signal is characteristic of a temperature in proximity to the sensor device (1) , and- the temperature signal is dependent on whether an object is in proximity to the sensor device (1) .

13. Method according to one of claims 1 to 12, wherein- the sensor device (1) is comprised by a human machine interface (4) , and- the sensor device (1) is configured to provide the displacement information and / or a velocity information of at least a part of the human machine interface (4) .

14. Human machine interface (4) comprising- a sensor device (1) , wherein- the human machine interface (4) is configured to perform the method according to one of claims 1 to 13.

15. System (5) comprising- the human machine interface (4) according to claim 14.

16. Computer program comprising instructions which, when the computer program is executed by a computer, cause the computer program to perform the method according to one of claims 1 to 13.

17. Computer-readable storage medium on which the computer program of claim 16 is stored.

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