ULTRASOUND DETECTION DEVICE FOR CONTACT DETECTION

Abstract

A system and method for ultrasonic event detection through a coupling substrate. The method comprises receiving a first echo signal from a first interface of a contact substrate and a second ultrasonic signal from a second interface of the contact substrate. The method comprises generating a response signal based on the second ultrasonic signal and a baseline signal. The method comprises detecting an event associated with the substrate based on the response signal. The method comprises providing a notification indicating the event.

Description

TECHNICAL AREA

[0001] The present disclosure relates generally to the field of electronics and in particular to an ultrasonic detection device for touch detection. BACKGROUND

[0002] Touch detection of surfaces or liquids using ultrasonic signals is currently being investigated as an alternative to capacitive touch detection principles. Ultrasonic detection relies on the transmission of an ultrasonic signal and the reception and processing of the reflected signal from the contact surface of a substrate. The signal's properties (e.g., amplitude, phase shift, etc.) depend on the presence or absence of a touch event. BRIEF DESCRIPTION OF THE FIGURES

[0003] The present disclosure is illustrated by way of example and without limitation in the figures of the accompanying drawings, in which the same reference signs refer to similar elements and in which: Fig. 1 a block diagram of an exemplary environment for using an ultrasonic sensing device to detect a human hand touching a substrate according to some embodiments; Fig. 2 shows a block diagram of an exemplary ultrasonic detection device which uses quadrature demodulation to detect a touch event associated with a substrate according to some embodiments; Fig. Figure 3 is a diagram showing echo signals transmitted through the TX / RX MEMS in Fig. 1 can be detected, according to some embodiments; Fig. 4 is a diagram that represents output samples generated by the ADC 210 based on echo signals according to some embodiments; Fig. 5 is a diagram that represents a time diagram for performing an automatic system calibration procedure to improve touch event sensitivity according to some embodiments; Fig. 6A is a diagram that represents a group of samples acquired by the ultrasonic sensing device by performing an ADC scan of the echo signals from its second interface, which is sensitive to touch events, according to some embodiments; Fig. 6B is a diagram that represents a raw data signal for indicating periods of contact events and periods of non-contact events according to some embodiments; Fig. 7 a flowchart of a touch detection procedure for detecting touch events based on the single signal generated from sampled echo signals according to some embodiments; Fig. 8 is a flowchart of a filter procedure for improving the SNR of the raw data signal according to some embodiments; Fig. 9 a flowchart of a baseline signal update / reset procedure for generating an updated baseline signal according to some embodiments; Fig. 10. A flowchart of a response signal calculation procedure for defining a system response to user activity according to some embodiments; and Fig. 11 is a flowchart of a touch detection procedure for detecting events using non-conventional / challenging coupling substrates according to some embodiments. DETAILED DESCRIPTION

[0004] The following description sets forth numerous specific details, such as examples of specific systems, components, methods, and so forth, to provide a good understanding of various embodiments of the techniques described herein, which are specifically designed to improve an ultrasonic sensing device capable of detecting events through conventional contact substrates (e.g., glass) and, furthermore, capable of detecting similar events through non-conventional contact substrates comprising at least one of metal, plastic, or wood. However, it will be obvious to a person skilled in the art that at least some embodiments can be implemented without these specific details.In other cases, known components, elements, or procedures are not described in detail or are presented in a simple block diagram format to avoid unnecessarily obscuring the techniques described herein. Therefore, the specific details set forth below are merely exemplary. Certain implementations may differ from these exemplary details and still be considered to be within the scope of protection of this disclosure.

[0005] For the sake of simplicity, many embodiments discussed herein describe an ultrasonic sensing device for detecting when a human finger touches a tactile substrate. However, it is understood that any of these embodiments can be configured to detect when any type of substrate touches the tactile substrate, as well as to detect / measure the level, proximity, presence, gesture, and / or the like.

[0006] Ultrasonic sensors (e.g., capacitive micromachined ultrasonic transducers like CMUT, ultrasonic microphones, etc.) possess unique properties, including miniature size, high electromagnetic compatibility (EMC), low radiation, the ability to propagate through metals and liquids, and the capacity to measure transit time. For these reasons, ultrasonic sensors have the potential to solve many challenging problems. For example, they can detect touch under almost any surface, as they can detect a human finger touch through various materials. Ultrasonic sensors can also measure level and proximity, as well as detect presence or gestures. The versatility of ultrasonic sensors makes them useful in a wide range of applications, such as medicine, automotive, household appliances, robotics, and mobile phones.Other technologies, such as capacitive and inductive, have limitations in these areas.

[0007] An ultrasonic sensor can detect whether a particular contact material (e.g., metal, glass, etc.) has been touched by another material (e.g., a human finger) based on the detection of a change in the amplitude of an echo signal (e.g., a continuous ultrasonic signal). That is, the ultrasonic sensor uses its transmission device to generate an echo signal and direct it toward the contact material, causing part or all of the echo signal to be reflected by the contact material.The ultrasonic sensor uses its receiver to detect the reflected echo signal and then employs a processing circuit to determine whether the amplitude of the reflected signal differs meaningfully from the amplitude of the echo signal, where the change in amplitude is caused, at least to some extent, by a change in the acoustic impedance at a contact interface of the contact material. In a non-contact event, the echo signal is almost completely reflected, producing a reflected echo signal at the ultrasonic sensor's receiver with an amplitude equal to or nearly equal to the amplitude of the transmitted echo signal. Alternatively, in a contact state, the material (e.g.,a human finger), touching the contact material, emits a portion of the ultrasound energy; thereby producing a reflected echo signal at the receiving device which has an amplitude smaller than the amplitude of the transmitted echo signal.

[0008] The conventional processing circuit includes filters, a rectifier, and an ADC. Specifically, the conventional ultrasonic sensor feeds the reflected echo signal to a bandpass filter, whose filtered output is then fed to a rectifier, whose rectified output is then fed to a lowpass filter, and whose filtered output is then fed to an ADC. The ADC samples the filtered output of the lowpass filter at a specific sampling rate to convert the filtered output (corresponding to the reflected echo signal) into a digital signal and provides the digital signal to a post-processing device. The post-processing device uses the digital signal to detect whether a touch event has occurred, based on the detection of a relatively small change in the amplitude of the echo signal.

[0009] However, conventional ultrasonic sensors are unable to detect touch events through coupling materials constructed of plastic, wood, and / or metal, as these materials block signals indicating changes in capacitance. Therefore, there has long been a need to provide a system and method for detecting touch events through coupling materials constructed of plastic, wood, and / or metal.

[0010] Aspects of the disclosure address the above-mentioned and other deficiencies by improving an ultrasonic detection device capable of detecting events through conventional contact substrates (e.g., glass) and furthermore capable of detecting similar events through non-conventional contact substrates comprising at least one of metal, plastic, or wood.

[0011] In one illustrative embodiment, an ultrasonic sensing device is coupled to a touch substrate (e.g., metal, plastic, wood, glass, liquid) that is periodically touched and left untouched by one or more human fingers. The ultrasonic sensing device comprises a microelectromechanical system (MEMS) transmission / receiving (Tx / Rx) unit, wherein the receiving unit also includes a processing circuit (e.g., filter, quadrature demodulator, ADC, and / or post-processors, etc.). In some embodiments, the processing circuit may be contained in one or more devices that are separate from and downstream of the ultrasonic sensing device. The Tx / Rx MEMS detects (e.g., receives) a first echo signal (e.g., ultrasonic signal) from a first interface of the touch substrate and a second ultrasonic signal from a second interface of the touch substrate.The ultrasonic detection device generates a response signal based on the second ultrasonic signal and a baseline signal. Based on this response signal, the ultrasonic detection device detects an event associated with the substrate. The ultrasonic detection device then provides a notification indicating the event.

[0012] Fig. Figure 1 presents a block diagram of an exemplary environment for using an ultrasonic sensing device to detect a human hand touching a substrate, according to some embodiments. The environment 100 comprises an ultrasonic sensing device 101 coupled to a touch substrate 104 (e.g., a smartphone screen). The ultrasonic sensing device 101 comprises a TX MEMS 102 and an RX MEMS 103, each connected to a first interface (in Fig. 1 shown as interface 1) of the contact substrate 104 are coupled via a coupling substrate 106.

[0013] The RX MEMS 103 comprises a processing circuit (e.g., filter, quadrature demodulator, ADC and / or post-processors, etc.) for processing the echo signals and reflected echo signals generated by the TX MEMS 102. In some embodiments, the processing circuit may instead be contained in one or more devices that are separate from and downstream of the ultrasonic sensing device. One or more fingers of a human hand 107 repeatedly touch the same and / or different areas of the touch substrate 104.

[0014] The first interface (e.g., Interface 1) is configured to be unaffected by the presence of a touch event (e.g., non-sensitive). The first interface generates an initial signal and provides the first signal to the processing circuitry of the RX MEMS 103, with this initial signal remaining unaffected by the presence or absence of a touch event.

[0015] The ultrasonic detection device 101 is configured to detect whether the human hand 107 is currently using a second interface (in Fig. 1 shown as interface 2) of the touch substrate 104, wherein the second interface (e.g. interface 2) is configured to be influenced by the presence of a touch event (e.g. sensitive to events).

[0016] For example, the TX MEMS 102 generates and transmits an echo signal 110a through the coupling substrate 106 (e.g., metal, plastic, wood, glass, liquid) and towards the contact substrate 104 at a time when a finger of the human hand 107 is not touching the contact substrate 104. The echo signal 110a reaches the first interface of the contact substrate 104, causing all or nearly all of the echo signal 110a to be reflected from the first interface to generate a reflected echo signal 110b, which is detected by the RX MEMS 103. The amplitude of the reflected echo signal 112b is equal to or nearly equal to the amplitude of the echo signal 112a.

[0017] Alternatively, the TX MEMS 102 generates and transmits an echo signal 112a through the coupling substrate 106 and towards the touch substrate 104 at the time a finger of the human hand 107 touches the touch substrate 104. However, when the echo signal 112a reaches the first interface of the touch substrate 104, some of the ultrasonic energy of the echo signal 112a is absorbed by the human finger touching the touch substrate; this causes the amplitude of the resulting reflected echo signal 112b to be smaller than the amplitude of the echo signal 112a.

[0018] It should be noted that the waves of the echo signals 110a, 110b, 112a and 112b, which are in Fig. Figure 1 is shown, is not to scale, and is not intended to show any specific size difference that may or may not exist between the echo signals.

[0019] Fig. Figure 2 shows a block diagram of an exemplary ultrasonic sensing device 101, which uses quadrature demodulation to detect a touch event associated with a substrate, according to some embodiments. The ultrasonic sensing device 101 comprises a TX / RX MEMS 202 (a combination of the TX MEMS 102 and the RX MEMS 103 in Fig. 1), a bandpass filter (BPF) 204, a quadrature demodulator 206, a lowpass filter (LPF) 208) and an ADC 210, an event processing device 212 and a digital control sequence controller 214.

[0020] The differential outputs of the TX / RX MEMS 202 are coupled to the inputs of the BPF 204, whose outputs are coupled to the inputs of the quadrature demodulator 206, whose outputs are coupled to the inputs of the LPF 208, whose outputs are coupled to the input of the ADC 210, whose output is coupled to the input of the event processing device 212, whose outputs are coupled to the input of the digital control unit 214. The output of the digital control unit 214 is distributed to a third input of the ADC 210, a third input of the quadrature demodulator 206, and a Tx input of the TX / RX MEMS 202.

[0021] The TX / RX MEMS 202 includes a transmission unit configured to generate an echo signal and direct it toward the touch substrate 104. The TX / RX MEMS 202 includes a receiving unit configured to receive the reflected echo signal and provide it to the BPF 204. The BPF 204 is configured to filter the reflected echo signal to produce a filtered signal and provide this filtered signal to the quadrature demodulator 206.

[0022] The quadrature demodulator 206 is configured to perform quadrature demodulation of the filtered signal (e.g., an ultrasound signal) to generate a differential in-phase (I) signal and a differential quadrature (Q) signal according to the procedures disclosed in U.S. patent application No. 18 / 638,511, which is incorporated herein by reference in its entirety. The quadrature demodulator 206 is configured to provide the differential I signal and the differential Q signal to the LPF 208.

[0023] The LPF 208 is configured to filter the differential I signal to generate a filtered differential I signal and provide the filtered differential I signal to the ADC. The LPF 208 is also configured to filter the differential Q signal to generate a filtered differential Q signal and provide the filtered differential Q signal to the ADC 210.

[0024] The ADC 210 is configured to generate a first digital signal based on the differential I signal and a second digital signal based on the differential Q signal using an ADC sampling rate.

[0025] The event processing device 212 is configured to detect an event associated with the touch substrate 104 based on the first and second digital signals by detecting a change in amplitude in the reflected echo signal, which provides a notification indicating the event. The event processing device 212 generates an output signal (“event flag”) indicating that an event (e.g., touch event, proximity event, level event, gesture event, presence event, etc.) associated with the touch substrate 104 has occurred.

[0026] The event processing device 212 sends the event flag to the ADC 210, the quadrature demodulator 206, and the TX / RX MEMS 202 to support different modes of the ultrasonic sensing device 101, depending on the specific application. For example, the ultrasonic sensing device 101 can configure the TX / RX MEMS 202 as a proximity sensor to determine that a user is not near the touch substrate 104 and, in response, configure the TX / RX MEMS 202 into a low-power state (“wake-on-touch mode”) that forces the TX / RX MEMS 202 to use a lower scan / refresh rate (e.g., 1 hertz (Hz)) when checking for events.When the event processing device 212 determines that the user is now near the touch substrate 104, the digital control sequence controller 214 can send the event flag to the TX / RX MEMS 202 to force the TX / RX MEMS 202 to wake up and return to normal power mode and then use the normal (e.g., 120 Hz) scan / refresh rate when checking for the same type of event or other types of events (e.g., gestures, touch, etc.).

[0027] The ultrasonic detection device 101 can control the time windows in which the TX / RX MEMS 202 generates echo signals (e.g., "excitation" phases) and the time windows in which the processing circuit waits to receive the echo signals (e.g., "listening" phases) by having the digital control sequence controller 214 send time signals to the Tx input of the TX / RX MEMS 202 to force the TX / RX MEMS 202 to generate echo signals. For example, the digital control sequence controller 214 sends an initial time signal to the TX / RX MEMS 202 and then waits and listens for the TX / RX MEMS 202 to generate an initial echo signal. The digital control sequence controller 214 then sends a second time signal to the TX / RX MEMS 202 and then waits and listens for the TX / RX MEMS 202 to generate a second echo signal. Thus, the excitation phases and the listening phases are temporally separated.

[0028] Although Fig. Figure 2 shows that the ultrasonic sensing device 101 includes the processing circuit (e.g., LPF 208, ADC 210, event processing device 212, digital control sequence controller 214) for processing the output of the quadrature demodulator 206. In other embodiments, one or more of the components of the processing circuit can be placed in other devices that are separate and downstream of the ultrasonic sensing device 101. For example, the ADC 210, the event processing device 212, and the digital control sequence controller 214 can each be located in a device that is separate from the ultrasonic sensing device 101.

[0029] Fig. Figure 3 is a diagram showing echo signals transmitted through the TX / RX MEMS in Fig. 1, as depicted in some embodiments. In particular, diagram 300 shows an echo signal 302 reflected from interface 1 (which is not sensitive to touch events) and directed towards the RX MEMS 103 of the ultrasonic detection device 101, and an echo signal 304 reflected from interface 2 (which is sensitive to touch events) and directed towards the RX MEMS 103 of the ultrasonic detection device 101. In some embodiments, the echo signal 302 refers to the output of the LPF 208, which is generated by passing a first echo signal reflected from interface 1 through the BPF 204, the quadrature demodulator 206, and the LPF 208.Likewise and in the same embodiment, the echo signal 304 refers to the output of the LPF 208, which is generated by passing a second echo signal, reflected from the interface 2, through the BPF 204, the quadrature demodulator 206 and the LPF 208.

[0030] Fig. Figure 4 is a diagram illustrating output samples generated by the ADC 210 based on echo signals according to some embodiments. In particular, Figure 4 shows output samples 402 and output samples 404. The ADC 210 generates the output samples 402 by sampling the echo signal 302 at a sampling rate of and generates the output samples 404 by sampling the echo signal 304 at a sampling rate of .

[0031] As discussed above, conventional ultrasonic sensors cannot detect touch events through coupling materials constructed of plastic, wood, and / or metal because the change in amplitude of an echo signal reflected by these materials in response to a touch event is smaller than the amplitude sensitivity of the conventional ultrasonic sensor. However, the ultrasonic sensing device 101 of the present disclosure is able to detect these minute amplitude changes because it performs an automatic system calibration procedure that improves its amplitude detection sensitivity, which in turn improves its touch event sensitivity.

[0032] Fig. Figure 5 is a diagram that depicts a timing diagram for performing an automatic system calibration procedure to improve touch event sensitivity according to some embodiments. Referring to Figure 500, the ultrasonic sensing device 101 performs the ACS procedure as follows:

[0033] The ultrasonic sensing device 101 analyzes the echo signal 302 to identify a local maximum (e.g., maximum amplitude) of the echo signal 302. The ultrasonic sensing device 101 analyzes the echo signal 304 to identify a local maximum of the echo signal 304. In some embodiments, the local maximum of the echo signal 302 and the local maximum of the echo signal 304 can be influenced by external factors, including, for example, temperature, silicon processing attributes, and voltage fluctuations. The ultrasonic sensing device 101 calculates an adjustment amount based on the local maximum of the echo signal 302 and / or the local maximum of the echo signal 304.The ultrasonic sensing device 101 then activates a receiver (Rx) to adjust a start time by the adjustment amount, the start time being when the ADC 210 begins to sample the echo signal 304 using its ADC 210 to generate a group of samples. In some embodiments, the ultrasonic sensing device 101 delays the start time for the echo signal 304 until after the local maximum of the echo signal 302. In some embodiments, the ultrasonic sensing device 101 advances the start time for the echo signal 304 so that it occurs before the local maximum of the echo signal 302.

[0034] Fig. Figure 6A is a diagram illustrating a group of samples acquired by the ultrasonic sensing device by performing an ADC scan of the echo signals from its second interface (e.g., interface 2), which is sensitive to touch events, according to some embodiments. In particular, Figure 600A shows a group of 12 samples (e.g., S0 to S1). 11 ), which are generated by the ADC 210, with each sample indicating either a touch event or a non-touch event for a given time.

[0035] The ultrasonic sensing device 101 then calculates (e.g., generates) a raw data signal (e.g., a single signal) based on the group of 12 samples. In some embodiments, the ultrasonic sensing device 101 calculates a raw data signal, referred to as a cmutRawData signal, based on the following equation: cmutRawData = max(S0, S1) + S3. In other words, the ultrasonic sensing device 101 calculates a cmutRawData signal by adding the maximum amplitude between S0 and S1 to the amplitude of S3.

[0036] In some embodiments, the ultrasonic sensing device 101 calculates a raw data signal based on the following equation: raw data = S0 + S1. In other words, the ultrasonic sensing device 101 calculates a raw data signal by adding the amplitude of S0 to the amplitude of S1.

[0037] In some embodiments, the ultrasonic sensing device 101 calculates a raw data signal based on the following equation: raw data = sum(abs(S i )). In other words, the ultrasonic detection device 101 calculates a raw data signal by adding the absolute value of the amplitudes of all signals (S0 to S1). 11 ).

[0038] Fig. Figure 6B is a diagram representing a raw cmut data signal for indicating periods of contact events and periods of non-contact events according to some embodiments. The ultrasonic sensing device 101 calculated the raw cmut data signal in diagram 600B based on the following equation: raw cmut data = max(S0, S1) + S3.

[0039] The ultrasonic detection device 101 then analyzes the raw data signal according to a touch detection procedure (e.g., as in Fig. (7 shown), to determine whether a contact event has occurred. For example, the ultrasonic detection device 101 can determine that there is a non-contact event during a first period, a contact event during a second period after the first period, a non-contact event during a third period after the second period, and a contact event during a fourth period after the third period.

[0040] Fig. Figure 7 is a flowchart of a touch detection procedure for detecting touch events based on the single signal generated from sampled echo signals, according to some embodiments. Although the operations in Fig. While the operations shown in Figure 7 are presented as integral operations in a specific sequence for illustrative purposes, in other implementations one or more operations, or parts thereof, are performed in a different sequence or overlapping in time, sequentially or in parallel, or are omitted, or one or more additional operations are added, or the procedure is modified in a combination of these ways. In some embodiments, the procedure 700 can be performed by processing logic comprising hardware (e.g., circuitry, dedicated logic, programmable logic, microcode, etc.), firmware, or a combination thereof. In some embodiments, some or all of the operations of the procedure 700 can be performed by one or more components (e.g., TX / RX MEMS 202, BPF 204, quadrature demodulator 206, LPF 208, ADC 210, event processing device 212, digital control sequence controller 214) of the ultrasonic sensing device 101.

[0041] In Operation 702, in some embodiments, the ADC 210 performs a scan (e.g., a sampling procedure) of an echo signal received from the second interface of the ultrasonic sensing device 101 to generate a group of samples (e.g., N samples), the second interface being sensitive to touch events. As discussed previously, Fig. 6A provides an example of a group of scans that can be detected by the ultrasonic detection device 101.

[0042] In operation 704, the event processing device 212, in some embodiments, calculates a raw data signal based on the group of N samples (e.g., 12 samples). As discussed previously, Fig. 6B provides an example of the raw data signal that can be calculated by the event processing device 212.

[0043] In operation 706, the event processing device 212, in some embodiments, filters the raw data signal according to a filtering procedure to produce a filtered raw data signal. Filtering the raw data signal improves the signal-to-noise ratio (SNR) of the raw data signal.

[0044] In operation 708, the event processing device 212, in some embodiments, updates or resets a baseline signal for the raw data signal according to a baseline signal update / reset procedure to produce an updated baseline signal that eliminates residual signals after a hard removal, prevents stuck false touch, and compensates for signals from a temperature drift.

[0045] In operation 710, the event processing device 212 calculates a response signal in some embodiments according to a response signal calculation procedure.

[0046] In operation 712, the event processing device 212 in some embodiments performs a touch detection procedure to generate an event flag indicating whether a touch event has occurred.

[0047] Fig. Figure 8 is a flowchart of a filter procedure (as previously in Fig. (7 discussed) to improve the SNR of the raw data signal according to some embodiments. Although the operations in Fig. While the operations in Figure 800 are shown for illustrative purposes as integral operations in a specific sequence, in other implementations one or more operations, or parts thereof, are performed in a different sequence or overlapping in time, sequentially or in parallel, or are omitted, or one or more additional operations are added, or the procedure is modified in a combination of these ways. In some embodiments, the procedure 800 can be performed by processing logic comprising hardware (e.g., circuitry, dedicated logic, programmable logic, microcode, etc.), firmware, or a combination thereof. In some embodiments, some or all of the operations of the procedure 800 can be performed by one or more components (e.g., TX / RX MEMS 202, BPF 204, quadrature demodulator 206, LPF 208, ADC 210, event processing device 212, digital control sequence controller 214) of the ultrasonic sensing device 101.

[0048] In operation 802, the ultrasonic detection device 101 sets IIR_FILTER_SHIFT to 8 and rawIIRshift to 2 in some embodiments.

[0049] In Operation 804, in some embodiments, the ADC 210 performs an ADC scan using IIR_FILTER_SHIFT and rawIIRshift of an echo signal received from the second interface of the ultrasonic sensing device 101 to generate a set of samples (e.g., N samples), the second interface being sensitive to touch events. In some embodiments, in Operation 804, the ADC 210 performs an ADC scan similar to the ADC scan performed in Operation 702 in Procedure 700.

[0050] In operation 806, the ultrasound detection device 101 in some embodiments sets cmutRohdatenfilt equal to cmutRohdaten.

[0051] In operation 808, the ultrasonic sensing device 101 in some embodiments calculates cmutRohdatenfiltScaled based on the following equation: cmutRohdatenfiltScaled = cmutRohdatenfilt < <IIR_FILTER_SHIFT.

[0052] In operation 810, in some embodiments, the ADC 210 performs an ADC scan using IIR_FILTER_SHIFT and rawIIRshift of an echo signal received from the second interface of the ultrasonic sensing device 101 to generate a group of samples (e.g., N samples), the second interface being sensitive to touch events.

[0053] In operation 812, the ultrasonic sensing device 101 in some embodiments calculates cmutRohdatenfiltScaled based on the following equation: cmutRohdatenfiltScaled = cmutRohdatenfiltScaled + (cmutRohdaten << (IIR_FILTER_SHIFT - rawIIRshift)) - (cmutRohdatenfiltScaled >> rawIIRshift).

[0054] In operation 814, the ultrasonic sensing device 101 in some embodiments calculates cmutRohdatenfilt based on the following equation: cmutRohdatenfilt = cmutRohdatenfiltScaled >> IIR_FILTER_SHIFT.

[0055] Procedure 800 ends with operation 816.

[0056] Fig. Figure 9 is a flowchart of a baseline signal update / reset procedure (as previously described in Fig. 7 discussed) to generate an updated baseline signal according to some embodiments. Although the operations in Fig. While the operations in Figure 900 are shown for illustrative purposes as integral operations in a specific sequence, in other implementations one or more operations, or parts thereof, are performed in a different sequence or overlapping in time, sequentially or in parallel, or are omitted, or one or more additional operations are added, or the procedure is modified in a combination of these ways. In some embodiments, the procedure 900 can be performed by processing logic comprising hardware (e.g., circuitry, dedicated logic, programmable logic, microcode, etc.), firmware, or a combination thereof. In some embodiments, some or all of the operations of the procedure 900 can be performed by one or more components (e.g., TX / RX MEMS 202, BPF 204, quadrature demodulator 206, LPF 208, ADC 210, event processing device 212, digital control sequence controller 214) of the ultrasonic sensing device 101.

[0057] As discussed below, by implementing procedure 900, the ultrasonic sensing device 101 (1) resets the baseline signal when a finger release is detected, (2) updates the baseline signal by one count on each blUpdateSpeed ​​scan if a touch event is not detected in the previous scan, (3) and does not update / reset the baseline signal if a touch event is detected in the previous scan.

[0058] In particular, in operation 902, the ultrasonic detection device 101 sets touchRemove to 0 in some embodiments to indicate that the touch event (e.g., one or more human fingers are still physically touching the coupling material) is not removed.

[0059] In operations 904 and 906, the ultrasonic detection device 101, in some embodiments, loops each of the previously stored signals (e.g., cmutRohdatenfiltStore) and sets each cmutRohdatenfiltStore (i) according to the following equation: cmutRohdatenfiltStore (i) = cmutRohdatenfiltStore (i+1).

[0060] In some embodiments, the ultrasonic detection device 101 shifts the buffer of previously stored signals to the left and removes the oldest signal according to the following pseudocode:

[0061] In operation 908, the ultrasound detection device 101 in some embodiments sets cmutRohdatenfiltStore (numberScanToStore-1) = cmutRohdatenfilt, where cmutRohdatenfilt refers to the current filtered raw data.

[0062] In operations 910 and 912, in some embodiments, the ultrasonic sensing device 101 loops through each of the stored signals (i) and determines whether cmutRohdatenfilt > (cmutRohdatenfiltStore (i) + finger threshold). In other words, the ultrasonic sensing device 101 compares the current filtered raw data with the previously stored raw data to determine whether the current filtered raw data exceeds any of the previously stored raw data. If so, the ultrasonic sensing device 101 proceeds to operation 914 to set touchRemove = 1 to indicate that the finger touch has been removed. The ultrasonic sensing device 101 proceeds to operation 916 after comparing the current filtered raw data with each of the previously stored raw data.

[0063] In operation 916, the ultrasonic sensing device 101, in some embodiments, determines whether the finger touch has been removed (e.g., touchRemove = 1). If so, the ultrasonic sensing device 101 proceeds to operation 918 to set cmutCount = 0 and reset the current baseline (e.g., cmutBaseline) according to the following equation: cmutBaseline = cmutRohdatenfilt. If not, the ultrasonic sensing device 101 proceeds to operation 920 to determine whether a touch event was not detected in the previous scan.

[0064] If a touch event was detected in the previous scan, then ultrasonic sensing device 101 proceeds to operation 924 to reset cmutCount to 0. However, if a touch event was not detected in the previous scan, then ultrasonic sensing device 101 proceeds to operation 922 to increment cmutCount according to the following equation: cmutCount = cmutCount + 1

[0065] In operation 925, the ultrasonic sensing device 101, in some embodiments, determines whether cmutCount = blUpdateSpeed ​​(a value representing the number of scans since the last update of the baseline signal). If no, then procedure 900 terminates. If yes, then the ultrasonic sensing device 101 proceeds to operation 926 to determine whether cmutDiffSig > 0.

[0066] If so, then the ultrasonic sensing device 101 proceeds to operation 928 to decrement cmutBaseline according to the following equation: cmutBaseline = cmutBaseline - 1, and then proceeds to operation 936. If not, then the ultrasonic sensing device 101 proceeds to operation 930 to determine if cmutDiffSig < NEG_LIMIT_THRESHOLD.

[0067] If less than this, then the ultrasonic sensing device 101 proceeds to operation 932 to update cmutBaseline according to the following equation: cmutBaseline = cmutBaseline + NEG_LIMIT_THRESHOLD, and then proceeds to operation 936. Otherwise, if not less than this, then the ultrasonic sensing device 101 proceeds to operation 934 to update cmutBaseline according to the following equation: cmutBaseline = cmutRohdatenfilt, and then proceeds to operation 936.

[0068] In some embodiments, during operation 936, the ultrasonic detection device 101 resets cmutCount to 0 and then proceeds to operation 938 to complete procedure 900.

[0069] Fig. Figure 10 is a flowchart of a response signal calculation procedure (as previously in Fig. (discussed in section 7) to define a system response to user activity according to some embodiments. Although the operations in Fig. While the operations in Figure 10 are shown for illustrative purposes as integral operations in a specific sequence, in other implementations one or more operations, or parts thereof, are performed in a different sequence or overlapping in time, sequentially or in parallel, or are omitted, or one or more additional operations are added, or the procedure is modified in a combination of these ways. In some embodiments, the procedure 1000 can be performed by processing logic comprising hardware (e.g., circuitry, dedicated logic, programmable logic, microcode, etc.), firmware, or a combination thereof. In some embodiments, some or all of the operations of the procedure 1000 can be performed by one or more components (e.g., TX / RX MEMS 202, BPF 204, quadrature demodulator 206, LPF 208, ADC 210, event processing device 212, digital control sequence controller 214) of the ultrasonic sensing device 101.

[0070] In some embodiments, during operation 1002, the ultrasonic sensing device 101 determines whether cmutBaseline is greater than cmutRohdatenfilt. If so, the ultrasonic sensing device 101 proceeds to operation 1004 to calculate a response signal (e.g., cmutDiffSig) according to the following equation: cmutDiffSig = cmutBaseline - cmutRohdatenfilt. If not, the ultrasonic sensing device 101 proceeds to operation 1006 to reset the response signal (e.g., cmutDiffSig) to 0. Procedure 1000 ends (e.g., is completed) at operation 1008.

[0071] Fig. Figure 11 is a flowchart of a touch detection procedure (as previously described in Fig. 7 discussed) for detecting events using non-conventional / challenging coupling substrates (e.g., wood, plastic, metal) according to some embodiments. Although the operations in Fig.While the operations in Figure 11 are shown for illustration as integral operations in a specific sequence, in other implementations one or more operations, or parts thereof, are performed in a different sequence or overlapping in time, sequentially or in parallel, or are omitted, or one or more additional operations are added, or the procedure is modified in a combination of these ways. In some embodiments, the procedure 1100 can be performed by processing logic comprising hardware (e.g., circuitry, dedicated logic, programmable logic, microcode, etc.), firmware, or a combination thereof. In some embodiments, some or all of the operations of the procedure 1100 can be performed by one or more components (e.g., TX / RX MEMS 202, BPF 204, quadrature demodulator 206, LPF 208, ADC 210, event processing device 212, digital control sequence controller 214) of the ultrasonic sensing device 101.

[0072] In operation 1102, the ultrasonic sensing device 101, in some embodiments, determines whether the response signal (e.g., cmutDiffSig) is greater than a finger threshold. If so, the ultrasonic sensing device 101 proceeds to operation 1104 to set touchDetect = 1 to indicate that a touch event is detected, and then proceeds to operation 1108. If not, the ultrasonic sensing device 101 proceeds to operation 1106 to set touchDetect = 0 to indicate that a touch event is not detected, and then proceeds to operation 1108.

[0073] In operation 1108, the ultrasonic sensing device 101, in some embodiments, determines whether a touch event is detected. If so, the ultrasonic sensing device 101 proceeds to operation 1110 to set the finger threshold according to the following equation: Finger Threshold = Finger Threshold - Finger Histeresis, and then proceeds to operation 1114. In other words, if the ultrasonic sensing device 101 detects a touch event in the current scan, it reduces the finger threshold to prevent system noise from causing an error (e.g., a false negative) in the ultrasonic sensing device 101 detecting a touch event.

[0074] If not, then the ultrasonic sensing device 101 proceeds to operation 1112 to set the finger threshold according to the following equation: Finger Threshold = Finger Threshold + Finger Histeresis, and then proceeds to operation 1114. In other words, if the ultrasonic sensing device 101 does not detect a touch event in the current scan, then the ultrasonic sensing device 101 increases the finger threshold to prevent system noise from causing the ultrasonic sensing device 101 to falsely report a touch event (e.g., false positive). Procedure 1100 ends at operation 1014.

[0075] The above description presents some sections of the detailed description in the form of algorithms and symbolic representations of operations on analog signals and / or digital signals or data bits within a non-volatile storage medium. These algorithmic descriptions and representations are the means used by professionals in the field of data processing to most effectively communicate the content of their work to other professionals. An algorithm is conceived here, and generally, as a self-consistent sequence of steps that leads to a desired result. The steps are those that require physical manipulation of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals that can be stored, transmitted, combined, compared, and otherwise manipulated.It has sometimes proven useful, mainly for reasons of general usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like.

[0076] The reference in the description to "an embodiment," "a single embodiment," "an exemplary embodiment," "some embodiments," and "different embodiments" means that a specific feature, structure, step, operation, or property described in connection with the embodiment(s) is included in at least one embodiment of the disclosure. Furthermore, the appearance of the expressions "an embodiment," "a single embodiment," "an exemplary embodiment," "some embodiments," and "different embodiments" at various points in the description does not necessarily all refer to the same embodiment(s).

[0077] The description includes references to the accompanying drawings, which form part of the detailed description. The drawings show illustrations according to exemplary embodiments. These embodiments, which may also be referred to herein as "examples," are described in sufficient detail to enable those skilled in the art to practice the embodiments of the claimed subject matter described herein. The embodiments may be combined, other embodiments may be used, or structural, logical, and electrical modifications may be made without departing from the scope of protection and spirit of the claimed subject matter. It is understood that the embodiments described herein are not intended to limit the scope of protection of the subject matter, but rather to allow those skilled in the art to practice, manufacture, and / or use the subject matter.

[0078] It should be borne in mind, however, that all these and similar terms are intended to be associated with the appropriate physical quantities and are merely convenient designations applied to those quantities. Unless specifically stated otherwise, as is evident from the discussion above, it is understood that throughout the description, discussions using terms such as receive, generate, detect, provide, adapt, calculate, sample, capture, compare, indicate, update, reset, or the like refer to the actions and processes of a controller of an integrated circuit (IC) or similar electronic device that process data which are considered physical (e.g.,electronic) quantities represented within the registers and memory of the controller, manipulated and converted into other data that are represented similarly as physical quantities within the memory or registers of the controller or any other such non-volatile information storage medium.

[0079] The words “example” or “exemplary” are used herein to mean that they serve as an example, instance, or illustration. Any aspect or design described herein as an “example” or “exemplary” is not necessarily to be construed as preferential or advantageous over other aspects or designs. Rather, the use of the words “example” or “exemplary” is intended to present concepts in a concrete way. As used in this application, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” That is to say, unless otherwise specified or clear from the context, “X includes A or B” is intended to mean any of the natural inclusive permutations. That is to say, if X includes A; X includes B; or X includes both A and B, then “X includes A or B” is satisfied under any one of the foregoing cases.Furthermore, the articles “a” and “an”, as used in this application and the attached claims, should generally be interpreted as meaning “one or more”, unless otherwise specified or it is clear from the context that they refer to a singular form. In addition, the use of the term “an embodiment” or “a single embodiment” or “an embodiment” or “a single embodiment” throughout should not mean the same embodiment or embodiment unless described as such.

[0080] The embodiments described herein may also refer to a device (e.g., an AC-DC converter and / or an ESD protection system / circuit) for performing the operations described herein. This device may be specially designed for the required purposes or may include firmware or hardware logic that is selectively enabled or reconfigured by the device. Such firmware may be stored in a non-volatile, computer-readable storage medium, such as, but not limited to, read-only memory (ROMs), random-access memory (RAMs), EPROMs, EEPROMs, flash memory, or any type of media suitable for storing electronic instructions. The term "computer-readable storage medium" should be understood to include a single medium or multiple media that store one or more sets of instructions.The term "computer-readable medium" shall also be understood to include any medium capable of storing, encoding, or carrying a set of instructions for execution by the machine, and which causes the machine to carry out one or more of the methodologies of the present embodiments. The term "computer-readable storage medium" shall accordingly be understood to include, among other things, solid-state storage media, optical media, magnetic media, and any medium capable of storing a set of instructions for execution by the machine, and which causes the machine to carry out one or more of the methodologies of the present embodiments.

[0081] The foregoing description sets forth numerous specific details, such as examples of specific systems, components, methods, and so forth, to provide a good understanding of several embodiments of the present disclosure. It is understood that the foregoing description is intended to be illustrative and not limiting. Many other embodiments will be apparent to the person skilled in the art upon reading and understanding the foregoing description. The scope of protection of the disclosure should therefore be determined by reference to the appended claims together with the full scope of protection of equivalents to which such claims entitle the holder. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 18 / 638,511

[0022]

Claims

[1] A procedure that includes the following: Receiving a first ultrasound signal from a first interface of a substrate and a second ultrasound signal from a second interface of the substrate; Generating a response signal based on the second ultrasound signal and a baseline signal; Detecting a substrate-associated event based on the response signal; and Providing a notification that indicates the event. [2] The method according to claim 1, further comprising: Calculating a time interval based on at least one of the first amplitudes of the first ultrasound signal or the second amplitude of the second ultrasound signal; and Adjusting the start time for sampling the second ultrasound signal based on the time interval to increase the amplitude difference between the first ultrasound signal and the second ultrasound signal. [3] The method according to claim 2, further comprising: Calculating a first maximum amplitude of the first ultrasound signal; and Calculating a second maximum amplitude of the first ultrasound signal, where the first amplitude corresponds to the first maximum amplitude and the second amplitude corresponds to the second maximum amplitude. [4] The method according to claim 1, further comprising: Sampling the first ultrasound signal at a sampling rate to generate an initial group of samples; Sampling the second ultrasound signal at the sampling rate to generate a second set of samples; and Calculating a raw data signal based on the second group of samples without considering the first group of samples. [5] The method according to claim 4, further comprising: Capturing a group of previously stored samples associated with a variety of ultrasound signals received from the substrate's second interface; Comparing the second group of samples and the group of previously stored samples to determine whether at least one sample from the second group of samples exceeds the group of previously stored samples; and either: Indicating that the event no longer exists in response to determining that at least one sample of the second set of samples exceeds the set of previously stored samples, or Indicates that the event still exists in response to determining that at least one sample of the second set of samples does not exceed the set of previously stored samples. [6] Method according to claim 5, wherein the indication that the event no longer exists further includes: Updating the baseline signal to generate an updated baseline that matches the raw data signal. [7] Method according to claim 6, wherein generating the response signal includes: Determine whether the updated baseline exceeds the second group of samples, and either: Generating the response signal by subtracting the second group of samples from the updated baseline in response to determining that the updated baseline exceeds the second group of samples, or Resetting the response signal in response to determining that the updated baseline does not exceed the second group of samples. [8] Method according to claim 7, wherein detecting the event associated with the substrate includes: Comparing the response signal and a predetermined threshold to determine whether the response signal exceeds the predetermined threshold; and either: Indicates that the event is detected in response to determining that the response signal exceeds the predetermined threshold, or Indicates that the event is not detected, in response to determining that the response signal does not exceed the predetermined threshold. [9] Method according to claim 8, wherein: indicating that the event is detected, and furthermore reducing the predetermined threshold to prevent a false negative detection of a second event associated with a third ultrasound signal, or This includes indicating that the event is not detected, and furthermore increasing the predetermined threshold to prevent a false positive detection of the second event associated with the third ultrasound signal. [10] Method according to claim 1, wherein the substrate comprises at least one of metal, wood or plastic. [11] An integrated circuit comprising the following: an ultrasonic sensing device configured to receive a first ultrasonic signal from a first interface of a substrate and a second ultrasonic signal from a second interface of the substrate; and a processing device coupled to the ultrasonic detection device, wherein the processing device is configured for the following: Generating a response signal based on the second ultrasound signal and a baseline signal; Detecting a substrate-associated event based on the response signal; and Providing a notification that indicates the event. [12] Integrated circuit according to claim 11, wherein the processing device is further configured for the following: Calculating a time interval based on at least one of the first amplitudes of the first ultrasound signal or the second amplitude of the second ultrasound signal; and Adjusting the start time for sampling the second ultrasound signal based on the time interval to increase the amplitude difference between the first ultrasound signal and the second ultrasound signal. [13] Integrated circuit according to claim 12, wherein the processing device is further configured for the following: Calculating a first maximum amplitude of the first ultrasound signal; and Calculating a second maximum amplitude of the first ultrasound signal, where the first amplitude corresponds to the first maximum amplitude and the second amplitude corresponds to the second maximum amplitude. [14] Integrated circuit according to claim 11, wherein the processing device is further configured for the following: Sampling the first ultrasound signal at a sampling rate to generate an initial group of samples; Sampling the second ultrasound signal at the sampling rate to generate a second set of samples; and Calculating a raw data signal based on the second group of samples without considering the first group of samples. [15] Integrated circuit according to claim 14, wherein the processing device is further configured for the following: Capturing a group of previously stored samples associated with a variety of ultrasound signals received from the substrate's second interface; Comparing the second group of samples and the group of previously stored samples to determine whether at least one sample from the second group of samples exceeds the group of previously stored samples; and either: Indicating that the event no longer exists in response to determining that at least one sample of the second set of samples exceeds the set of previously stored samples, or Indicates that the event still exists in response to determining that at least one sample of the second set of samples does not exceed the set of previously stored samples. [16] Integrated circuit according to claim 15, wherein, in order to indicate that the event no longer exists, the processing device is further configured to: Updating the baseline signal to generate an updated baseline that matches the raw data signal. [17] Integrated circuit according to claim 16, wherein, in order to generate the response signal, the processing device is further configured to: Determine whether the updated baseline exceeds the second group of samples, and either: Generating the response signal by subtracting the second group of samples from the updated baseline in response to determining that the updated baseline exceeds the second group of samples, or Resetting the response signal in response to determining that the updated baseline does not exceed the second group of samples. [18] Integrated circuit according to claim 17, wherein, in order to detect the event associated with the substrate, the processing device is further configured to: Comparing the response signal and a predetermined threshold to determine whether the response signal exceeds the predetermined threshold; and either: Indicates that the event is detected in response to determining that the response signal exceeds the predetermined threshold, or Indicates that the event is not detected, in response to determining that the response signal does not exceed the predetermined threshold. [19] Integrated circuit according to claim 18, wherein: the processing device indicates that the event is detected by further reducing the predetermined threshold to prevent a false negative detection of a second event associated with a third ultrasound signal, or The processing device indicates that the event will not be detected by further increasing the predetermined threshold in order to prevent a false positive detection of the second event associated with the third ultrasound signal. [20] A procedure that includes the following: Receiving a first ultrasound signal from a first interface of a substrate and a second ultrasound signal from a second interface of the substrate, wherein the substrate includes at least one of metal, wood or plastic; Generating a response signal based on the second ultrasound signal and a baseline signal; and Detecting a substrate-associated event based on the response signal.

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