Optical sensor chip for distance detection and intelligent equipment

Abstract

According to the optical sensor chip for distance detection and the intelligent device, the amplitude-frequency information is obtained by performing frequency domain transformation on multiple pieces of reflected light data, the distance of the intelligent device is judged according to the amplitude corresponding to the set frequency in the amplitude-frequency information, and the set frequency is the frequency of emitted light. According to the embodiment, only the amplitude of the specific frequency point is concerned, interference light information of other frequencies in the environment is effectively shielded, the anti-interference capacity of distance detection is improved, interaction information of emitted light and an object can be extracted more accurately, and therefore the sensitivity of distance detection is improved. Moreover, due to the improvement of the anti-interference capability and the sensitivity, the requirement of the scheme on the intensity of the emitted light is reduced, and the power consumption and the cost of the intelligent equipment are reduced.

Description

Technical Field

[0001] The present application relates to the field of distance measurement technology, and in particular to an optical sensor chip and an intelligent device for distance detection. Background Art

[0002] The optical distance sensor chip is an indispensable component in smart terminals such as mobile phones and tablets. In smart phones, it is usually placed in the narrow slit at the top of the phone screen, or directly placed below the screen. The working principle of the optical distance sensor is as follows: Figure 1 As shown in the figure, it works based on the infrared light reflection principle. When an object (such as a face) approaches the sensor, the infrared light is reflected back and received by the sensor, and the distance between the object and the sensor is determined by measuring the intensity of the reflected light. When the distance is less than a certain set value, the sensor triggers a corresponding action, such as turning off the screen. The application scenarios of the optical distance sensing chip include call prevention, intelligent screen light control, pocket mode and false touch protection, etc.

[0003] The distance detection function senses nearby objects through infrared emission and detection. The integration process is divided into two stages, such as Figure 2 As shown, the B stage integrates the background light, and the A stage controls the IR emmiter to emit infrared light and integrates the reflected light at the same time. The integration of the A stage includes the background light and the IR reflected light. The reflected light data P_Data is obtained by subtracting the two-stage integration. In a distance detection process, the two integration stages are repeated many times, and the multiple results are accumulated as the final output, namely P_DATA in formula (2). If P_DATA is greater than the upper limit value, it means that the object is far away; if P_DATA is less than the lower limit threshold, it means that the object is close.

[0004] (1) (2) Since the light needs to pass through the screen twice, the loss is as high as 99%. Combined with the interference of ambient light, the detection accuracy is not high. In order to improve the signal-to-noise ratio, certain requirements are required for the intensity of the infrared emission light. However, strong light shining on one point for a long time will damage the screen and affect the life of the screen.

[0005] In addition, the traditional detection method is easily affected by the light of the screen. In order to avoid the interference of the screen light, the detection can only be performed before a new frame signal is refreshed and the screen is not lit. The screen refresh signal Vsync is required for synchronization, such as Figure 3 As shown, VCSEL light emission and circuit integration can only be performed in a certain period between two Vsync signals. Summary of the invention

[0006] The purpose of the embodiments of the present application is to provide a light sensor chip and a smart device for distance detection, so as to solve the problem that the existing light distance sensing chip is greatly disturbed by ambient light and screen light and has high requirements on the intensity of infrared emission light.

[0007] An optical sensor chip for distance detection provided in an embodiment of the present application is arranged under the screen of a smart device, and the optical sensor chip comprises: a transmitting optical circuit, a receiving optical circuit and a digital control circuit; the transmitting optical circuit is connected to the digital control circuit, and the receiving optical circuit is connected to the digital control circuit; the transmitting optical circuit and the receiving optical circuit are arranged close to the screen of the smart device; An emission light circuit, used to: emit emission light with set parameters under the screen of a smart device; wherein the set parameters include a set frequency; The receiving optical circuit is used to: receive light under the screen of the smart device, integrate the received light according to fixed stages to obtain an optical signal; and obtain a digital signal corresponding to each stage according to the optical signal; The digital control circuit is used for: two adjacent stages are grouped as one, in each group, the digital signals of the two stages are subtracted to obtain a reflected light data; m reflected light data are frequency-domain transformed to obtain amplitude-frequency information; wherein m is a positive power of 2; and according to the amplitude corresponding to the set frequency in the amplitude-frequency information, a distance indication signal or a proximity indication signal is output.

[0008] The away indication signal is used to indicate that the smart device is away, and the approach indication signal is used to indicate that the smart device is approaching.

[0009] In the above technical solution, the frequency domain transformation is performed on multiple reflected light data to obtain amplitude-frequency information, and the distance of the smart device is judged according to the amplitude corresponding to the set frequency in the amplitude-frequency information, where the set frequency is the frequency of the emitted light. This embodiment effectively shields the interference light information of other frequencies in the environment by only focusing on the amplitude of a specific frequency point, improves the anti-interference ability of distance detection, and can more accurately extract the information of the interaction between the emitted light and the object, thereby improving the sensitivity of distance detection. In addition, due to the improvement of anti-interference ability and sensitivity, this solution reduces the intensity requirements of the emitted light, which helps to reduce the power consumption and cost of smart devices.

[0010] In some optional embodiments, the emitting light circuit includes a plurality of emitting light units disposed at different positions, and the plurality of emitting light units emit emitting light of a set frequency and the same phase.

[0011] In the above technical solution, multiple emitted lights with set frequencies and the same phase are used. These emitted lights are emitted from different positions under the screen. By dispersing the intensity and position of the emitted lights, the damage to a single point on the screen is reduced, while ensuring the accuracy and reliability of distance detection.

[0012] In some optional embodiments, the emitting light circuit includes multiple emitting light units arranged at different positions; the frequencies of the emitted lights of the multiple emitting light units are all less than the set frequency, the phases of the emitted lights of the multiple emitting light units are different, and the emitted lights of the multiple emitting light units are equivalent to the emitted light of the set frequency after superposition.

[0013] In the above technical solution, multiple emission lights with different phases and lower than the set frequency are used. These emission lights are emitted from different positions under the screen. The intensity and position of the emission lights are dispersed to different positions under the screen, reducing the damage to a single point on the screen. After multiple emission lights with different phases are superimposed in space, they can produce an emission light effect equivalent to the set frequency, thereby ensuring the detection effect while further reducing the damage to the screen by reducing the frequency of the emission light.

[0014] In some optional implementations, the digital control circuit is further used for: According to the amplitude corresponding to the frequency set in the amplitude-frequency information, the output is a distance indication signal or a proximity indication signal: If the amplitude corresponding to the set frequency in the amplitude-frequency information is greater than the second threshold, a proximity indication signal is output; If the amplitude corresponding to the set frequency in the amplitude-frequency information is less than the first threshold, a distance indication signal is output; The second threshold is greater than or equal to the first threshold.

[0015] In the above technical solution, the first threshold is a lower amplitude threshold, which is used to determine whether the smart device is far away from the object (or human body). When the amplitude corresponding to the set frequency in the amplitude-frequency information is lower than this threshold, it can be considered that the distance between the smart device and the object (or human body) is far. The second threshold is a higher amplitude threshold, which is used to determine whether the smart device is close to the object (or human body). When the amplitude corresponding to the set frequency in the amplitude-frequency information is higher than this threshold, it can be considered that the distance between the smart device and the object (or human body) is close, that is, the smart device is approaching the object (or human body).

[0016] In some optional embodiments, the emitting light circuit includes n emitting light units arranged at different positions, and the n emitting light units emit emitting light of different frequencies.

[0017] In some optional implementations, the digital control circuit is further used for: According to the amplitude corresponding to the frequency set in the amplitude-frequency information, the output is a distance indication signal or a proximity indication signal: If the amplitudes corresponding to the n different frequencies in the amplitude-frequency information are all greater than their respective corresponding second thresholds, a proximity indication signal is output; If the amplitudes corresponding to the n different frequencies in the amplitude-frequency information are all smaller than their respective corresponding first thresholds, a distance indication signal is output.

[0018] In the above technical solution, during configuration, multiple frequencies of emitted light are configured. In the subsequent threshold judgment step, only when the amplitudes corresponding to the multiple frequencies are greater than the respective corresponding second thresholds, the smart device is considered to be approaching, or, only when the amplitudes corresponding to the multiple frequencies are less than the respective corresponding first thresholds, the smart device is considered to be far away, which further reduces the interference of flickering light of specific frequencies in the environment. Among them, these thresholds can be the same or different. Because even if the emitted light of a certain frequency is interfered by flickering light, the emitted light of other frequencies can still provide accurate information. Only when the amplitudes of all frequencies are greater than or less than their respective thresholds, a judgment of approaching or moving away is made. This embodiment provides a multi-frequency detection method, which improves the anti-interference ability and reliability of the system by increasing the redundancy of information. The multi-frequency detection method can also adjust the frequency and threshold size according to actual needs to adapt to different application scenarios and object types.

[0019] In some optional implementations, the digital control circuit is further used for: According to the amplitude corresponding to the frequency set in the amplitude-frequency information, the output is a distance indication signal or a proximity indication signal: The amplitudes corresponding to n different frequencies are weighted and summed to obtain an amplitude evaluation value; wherein the weights corresponding to different frequencies are positively correlated with the amplitudes of the corresponding emitted light; If the amplitude evaluation value is greater than a fourth threshold, a proximity indication signal is output; If the amplitude evaluation value is less than the third threshold, a distance indication signal is output; The fourth threshold is greater than or equal to the third threshold.

[0020] In the above technical solution, during configuration, multiple frequencies of emitted light are configured. In the subsequent threshold judgment step, the amplitudes corresponding to n different frequencies are weighted and summed to obtain the amplitude evaluation value. The weight here is determined according to the amplitude of the corresponding emitted light, that is, the larger the amplitude of the emitted light, the larger the corresponding weight. This weighting method can ensure that in the summation process, the frequency that contributes more to the detection has a greater influence. In different application scenarios, the frequency and single luminous intensity of the emitted light can be flexibly configured to adjust the detection distance range. If the amplitude evaluation value is greater than the fourth threshold, it is considered that the smart device is approaching the object. If the amplitude evaluation value is less than the third threshold, it is considered that the smart device is moving away from the object. This embodiment can more comprehensively consider the reflected light signal intensity of all frequencies through the weighted summation method, thereby more accurately reflecting the distance change between the smart device and the object. Since the degree of environmental interference of emitted light of different frequencies may be different, the weighted summation method can reduce the impact of severe interference on the overall judgment of a single frequency, thereby improving the robustness of the system.

[0021] In addition, the weights can be adjusted according to actual needs to adapt to different application scenarios and object types. For example, in certain specific environments, certain frequencies of emitted light may be more susceptible to interference, and the impact of interference can be reduced by reducing the weights of these frequencies.

[0022] Different third and fourth thresholds may be set for different screen transmittances. In applications with relatively low screen transmittances, the third and fourth thresholds are set to relatively small values; in applications with relatively high screen transmittances, the third and fourth thresholds are set to relatively large values.

[0023] In some optional embodiments, the receiving optical circuit includes: a photodiode, a programmable gain amplifier, and an analog-to-digital converter connected in sequence; A photodiode is used to: integrate each stage in the optical signal to obtain the charge amount of each stage; wherein the length of the stage is the length of a single pulse; A programmable gain amplifier is used to: convert the charge amount of each stage into the voltage value of each stage; The analog-to-digital converter is used to convert the voltage value of each stage into the digital signal of each stage.

[0024] In the above technical solution, after the integration stage, the amount of charge output by the photodiode represents the intensity of the light signal. In order to convert these charges into analog voltage signals that can be used for subsequent processing, a programmable gain amplifier (PGA) is used. The PGA can adjust the gain as needed to ensure that the converted analog voltage signal is within the input range of the ADC and avoid signal saturation or distortion. The gain of the PGA can be dynamically adjusted according to the intensity of the background light and reflected light. For example, when the background light is strong, the gain can be appropriately reduced to avoid signal saturation; when the reflected light is weak, the gain can be increased to improve the signal-to-noise ratio of the signal.

[0025] The analog voltage signal amplified by the PGA is sent to the analog-to-digital converter (ADC) for digitization. The resolution of the ADC determines the accuracy of the converted digital signal. A high-resolution ADC can provide a more accurate digital signal, allowing for more sophisticated analysis and processing of the optical signal.

[0026] Subsequently, in the digital control circuit, two adjacent stages are grouped together. In each group, the digital signals of the two stages are subtracted to obtain a reflected light data. Among them, the two stages in each group may be two background light integration stages, or may be one background light integration stage and one reflected light integration stage. The background light integration stage is when the emitted light is not emitted, and the receiving device receives the background light. At this time, the received light signal is integrated to obtain the charge amount of the background light integration stage. The reflected light integration stage is when the emitted light is emitted, and the receiving device receives the background light and the reflected light. At this time, the received light signal is integrated to obtain the charge amount of the reflected light integration stage. The charge amount of the background light integration stage is converted into a background light digital signal, and the charge amount of the reflected light integration stage is converted into a reflected light digital signal; the background light digital signal and the reflected light digital signal of the adjacent integration stages are subtracted, that is, the influence of the background light on the reflected light measurement is eliminated, and the reflected light data is extracted. The size of the reflected light data reflects the reflection intensity of the target object to the emitted light, which can be used to determine the distance between the smart device and the target object.

[0027] In some optional implementations, the digital control circuit is further connected to the data storage unit, the register module and the interrupt module; the register module is further connected to the power management module, the oscillator and the communication interface.

[0028] Among them, the register module is used to manage the configuration and chip working status; Interrupt module, used to report special events, such as approach, distance, data anomaly, etc. Oscillator, used to generate internal operating clock.

[0029] An intelligent device provided in an embodiment of the present application includes a light sensor chip as described in any one of the above items. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 This is a schematic diagram of the working principle of the optical distance sensing chip; Figure 2 Schematic diagram of the integration process of the optical distance sensing chip; Figure 3 It is the timing diagram of VCSEL light emission and Vsync signal; Figure 4A functional module diagram of a light sensor chip for distance detection provided in an embodiment of the present application; Figure 5 A schematic diagram of the circuit structure of a light sensor chip provided in an embodiment of the present application; Figure 6 A schematic diagram of the integration process of the distance detection method provided in an embodiment of the present application; Figure 7 A schematic diagram of screen damage caused by different emission light configurations provided in an embodiment of the present application; Figure 8 The first emission light waveform diagram provided in the embodiment of the present application; Fig. 9 A second emission light waveform diagram provided in an embodiment of the present application; Fig.10 A third emission light waveform diagram provided in an embodiment of the present application; Fig.11 This is a schematic diagram of the structure of the optical sensor chip provided in an embodiment of the present application. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0033] Please refer to Figure 4 , Figure 4 A functional module diagram of a light sensor chip for distance detection provided in an embodiment of the present application, wherein the light sensor chip is arranged under the screen of a smart device, and the light sensor chip includes: an emitting light circuit, a receiving light circuit and a digital control circuit; the emitting light circuit is connected to the digital control circuit, and the receiving light circuit is connected to the digital control circuit; the emitting light circuit and the receiving light circuit are arranged close to the screen of the smart device.

[0034] Among them, the transmitting light circuit is used to: transmit the transmitting light of the set parameters under the screen of the smart device; wherein the set parameters include the set frequency. The receiving light circuit is used to: receive light under the screen of the smart device, integrate the received light according to fixed stages to obtain a light signal; and obtain a digital signal corresponding to each stage according to the light signal. The digital control circuit is used to: group two adjacent stages into a group, and in each group, subtract the digital signals of the two stages to obtain a reflected light data; perform frequency domain transformation on m reflected light data to obtain amplitude-frequency information; wherein m is a positive power of 2; and output a distance indication signal or a proximity indication signal according to the amplitude corresponding to the set frequency in the amplitude-frequency information. Among them, the distance indication signal is used to indicate that the smart device is far away, and the proximity indication signal is used to indicate that the smart device is approaching.

[0035] In the embodiment of the present application, the frequency domain transformation is performed on multiple reflected light data to obtain amplitude-frequency information, and the distance of the smart device is judged according to the amplitude corresponding to the set frequency in the amplitude-frequency information, where the set frequency is the frequency of the emitted light. By focusing only on the amplitude of a specific frequency point, this embodiment effectively shields the interference light information of other frequencies in the environment, improves the anti-interference ability of distance detection, and can more accurately extract the information of the interaction between the emitted light and the object, thereby improving the sensitivity of distance detection. In addition, due to the improvement of anti-interference ability and sensitivity, this solution reduces the intensity requirements of the emitted light, which helps to reduce the power consumption and cost of smart devices.

[0036] In some optional embodiments, the receiving optical circuit includes: a photodiode, a programmable gain amplifier, and an analog-to-digital converter connected in sequence; The photodiode is used to integrate each stage of the optical signal to obtain the charge amount of each stage; wherein the length of the stage is the length of a single pulse. The programmable gain amplifier is used to convert the charge amount of each stage into the voltage value of each stage. The analog-to-digital converter is used to convert the voltage value of each stage into the digital signal of each stage.

[0037] In an embodiment of the present application, after the integration phase, the amount of charge output by the photodiode represents the intensity of the light signal. In order to convert these charges into analog voltage signals that can be used for subsequent processing, a programmable gain amplifier (PGA) is used. The PGA can adjust the gain as needed to ensure that the converted analog voltage signal is within the input range of the ADC and to avoid signal saturation or distortion. The gain of the PGA can be dynamically adjusted according to the intensity of the background light and the reflected light. For example, when the background light is strong, the gain can be appropriately reduced to avoid signal saturation; when the reflected light is weak, the gain can be increased to improve the signal-to-noise ratio of the signal.

[0038] The analog voltage signal amplified by the PGA is sent to the analog-to-digital converter (ADC) for digitization. The resolution of the ADC determines the accuracy of the converted digital signal. A high-resolution ADC can provide a more accurate digital signal, allowing for more sophisticated analysis and processing of the optical signal.

[0039] Subsequently, in the digital control circuit, two adjacent stages are grouped together. In each group, the digital signals of the two stages are subtracted to obtain a reflected light data. Among them, the two stages in each group may be two background light integration stages, or may be one background light integration stage and one reflected light integration stage. The background light integration stage is when the emitted light is not emitted, and the receiving device receives the background light. At this time, the received light signal is integrated to obtain the charge amount of the background light integration stage. The reflected light integration stage is when the emitted light is emitted, and the receiving device receives the background light and the reflected light. At this time, the received light signal is integrated to obtain the charge amount of the reflected light integration stage. The charge amount of the background light integration stage is converted into a background light digital signal, and the charge amount of the reflected light integration stage is converted into a reflected light digital signal; the background light digital signal and the reflected light digital signal of the adjacent integration stages are subtracted, that is, the influence of the background light on the reflected light measurement is eliminated, and the reflected light data is extracted. The size of the reflected light data reflects the reflection intensity of the target object to the emitted light, which can be used to determine the distance between the smart device and the target object.

[0040] The optical sensor chip of one or more of the above embodiments may be packaged as follows: Fig.11 The chip shown in this embodiment has four emitting light units, and a light isolation component is provided between the four emitting light units and the receiving light circuit.

[0041] Please refer to Figure 5 , Figure 5 This is a schematic diagram of the circuit structure of the optical sensor chip provided in an embodiment of the present application.

[0042] In some optional implementations, the digital control circuit is further connected to the data storage unit, the register module and the interrupt module; the register module is further connected to the power management module POR, the oscillator OSC and the communication interface.

[0043] Among them, the register module is used to manage the configuration and chip working status; the interrupt module is used to report special events, such as approach, distance, data anomaly, etc.; the oscillator is used to generate the internal working clock.

[0044] In this embodiment, the data storage unit is SRAM, the SRAM is also connected to the register, and the communication interface is I2C Slave; wherein, SRAM is called Static Random-Access Memory, which is an important type of computer memory; I2C Slave (also called IIC Slave) is a role in the I2C (Inter-Integrated Circuit, two-wire serial bus) communication protocol, corresponding to the I2C Master.

[0045] The light emitting unit of this embodiment includes an overcurrent protection circuit, a light emitting drive circuit, a laser Laser and a voltage stabilizing diode ZD. Among them, the overcurrent protection circuit prevents the laser from being damaged due to excessive current during operation. When the current in the laser exceeds the set threshold, the overcurrent protection circuit will respond quickly and reduce the current through shunting or other mechanisms, thereby protecting the laser from damage. The light emitting drive circuit provides a stable driving current for the laser to produce a stable light output. The laser (Laser) converts electrical signals into optical signals. The voltage stabilizing diode (ZD) is used to stabilize the power supply voltage and protect the circuit from voltage fluctuations. The voltage stabilizing diode has a special reverse breakdown characteristic. When the reverse voltage reaches a certain value, reverse breakdown occurs. At this time, the current increases sharply, but the voltage remains basically unchanged. This characteristic enables the voltage stabilizing diode to provide a stable voltage output in the circuit.

[0046] The optical sensor chip of this embodiment further includes an OTP (One-Time Programmable) for adjusting circuit parameters according to actual measurement results.

[0047] Please refer to Figure 6 , Figure 6 This is a schematic diagram of the integration process of the distance detection method provided in the embodiment of the present application. The emission light VCSEL_ON in this embodiment has two frequency points. The P1 group includes the background light integration stage B1 and the reflected light integration stage A1, the P2 group includes the background light integration stage B2 and the reflected light integration stage A2, the P3 group includes the background light integration stages B3 and A3, the P2 group includes two background light integration stages B4 and A4, and so on. Then the reflected light data corresponding to the Pi group is:

[0048] in, is the digital signal of the Ai stage, It is the digital signal of Bi phase.

[0049] Subsequent Perform FFT frequency domain transform, that is: FFT_output=abs(fft(P_Data)).

[0050] In some optional embodiments, the emitting light circuit includes a plurality of emitting light units disposed at different positions, and the plurality of emitting light units emit emitting light of a set frequency and the same phase.

[0051] In an embodiment of the present application, multiple emitted lights with set frequencies and the same phase are used. These emitted lights are emitted from different positions under the screen. By dispersing the intensity and position of the emitted lights, the damage to a single point on the screen is reduced, while ensuring the accuracy and reliability of distance detection.

[0052] In some optional embodiments, the emitting light circuit includes multiple emitting light units arranged at different positions; the frequencies of the emitted lights of the multiple emitting light units are all less than the set frequency, the phases of the emitted lights of the multiple emitting light units are different, and the emitted lights of the multiple emitting light units are equivalent to the emitted light of the set frequency after superposition.

[0053] In the embodiment of the present application, multiple emission lights with different phases and lower than the set frequency are used. These emission lights are emitted from different positions under the screen, and the intensity and position of the emission lights are dispersed to different positions under the screen, reducing the damage to a single point on the screen. After multiple emission lights with different phases are superimposed in space, they can produce an emission light effect equivalent to the set frequency, thereby ensuring the detection effect while further reducing the damage to the screen by reducing the frequency of the emission light.

[0054] In some optional embodiments, the digital control circuit is also used to: output a distance indication signal or a proximity indication signal according to the amplitude corresponding to the set frequency in the amplitude-frequency information: if the amplitude corresponding to the set frequency in the amplitude-frequency information is greater than the second threshold, then the proximity indication signal is output; if the amplitude corresponding to the set frequency in the amplitude-frequency information is less than the first threshold, then the distance indication signal is output; wherein the second threshold is greater than or equal to the first threshold.

[0055] In the embodiment of the present application, the first threshold is a lower amplitude threshold, which is used to determine whether the smart device is far away from the object (or human body). When the amplitude corresponding to the set frequency in the amplitude-frequency information is lower than this threshold, it can be considered that the distance between the smart device and the object (or human body) is far. The second threshold is a higher amplitude threshold, which is used to determine whether the smart device is close to the object (or human body). When the amplitude corresponding to the set frequency in the amplitude-frequency information is higher than this threshold, it can be considered that the distance between the smart device and the object (or human body) is close, that is, the smart device is approaching the object (or human body).

[0056] In some optional embodiments, the emitting light circuit includes n emitting light units arranged at different positions, and the n emitting light units emit emitting light of different frequencies.

[0057] In some optional embodiments, the digital control circuit is also used to: output a distance indication signal or a proximity indication signal according to the amplitude corresponding to the set frequency in the amplitude-frequency information: if the amplitudes corresponding to n different frequencies in the amplitude-frequency information are all greater than their respective corresponding second thresholds, then a proximity indication signal is output; if the amplitudes corresponding to n different frequencies in the amplitude-frequency information are all less than their respective corresponding first thresholds, then a distance indication signal is output.

[0058] In the embodiment of the present application, during configuration, emission lights of multiple frequencies are configured. In the subsequent threshold judgment step, only when the amplitudes corresponding to the multiple frequencies are greater than the respective corresponding second thresholds, the smart device is considered to be approaching, or, only when the amplitudes corresponding to the multiple frequencies are less than the respective corresponding first thresholds, the smart device is considered to be far away, further reducing the interference of flickering light of specific frequencies in the environment. Among them, these thresholds can be the same or different. Because even if the emission light of a certain frequency is interfered by flickering light, the emission light of other frequencies can still provide accurate information. Only when the amplitudes of all frequencies are greater than or less than their respective thresholds, a judgment of approaching or moving away is made. This embodiment provides a multi-frequency detection method, which improves the anti-interference ability and reliability of the system by increasing the redundancy of information. The multi-frequency detection method can also adjust the frequency and threshold size according to actual needs to adapt to different application scenarios and object types.

[0059] In some optional embodiments, the digital control circuit is also used to: output a distance indication signal or a proximity indication signal according to the amplitude corresponding to the set frequency in the amplitude-frequency information: perform weighted summation of the amplitudes corresponding to n different frequencies to obtain an amplitude evaluation value; wherein the weights corresponding to different frequencies are positively correlated with the amplitude of the corresponding emitted light; if the amplitude evaluation value is greater than a fourth threshold, output a proximity indication signal; if the amplitude evaluation value is less than the third threshold, output a distance indication signal; wherein the fourth threshold is greater than or equal to the third threshold.

[0060] In the embodiment of the present application, during configuration, multiple frequencies of emitted light are configured, and in the subsequent threshold judgment step, the amplitudes corresponding to n different frequencies are weighted and summed to obtain an amplitude evaluation value. The weight here is determined according to the amplitude of the corresponding emitted light, that is, the larger the amplitude of the emitted light, the larger the corresponding weight. This weighting method can ensure that in the summation process, the frequency that contributes more to the detection has a greater influence, and the frequency and single luminous intensity of the emitted light can be flexibly configured in different application scenarios to adjust the detection distance range. If the amplitude evaluation value is greater than the fourth threshold, it is considered that the smart device is approaching the object. If the amplitude evaluation value is less than the third threshold, it is considered that the smart device is moving away from the object. This embodiment can more comprehensively consider the reflected light signal intensity of all frequencies through the weighted summation method, thereby more accurately reflecting the distance change between the smart device and the object. Since the degree of environmental interference of emitted light of different frequencies may be different, the weighted summation method can reduce the impact of severe interference on the overall judgment of a single frequency, thereby improving the robustness of the system.

[0061] Specifically, the transmitting light circuit may include two transmitting light units, which transmit light of different frequencies. The transmitting light circuit may also include three transmitting light units, which transmit light of different frequencies. Even if the received light of one frequency is interfered by the external ambient light, since the present solution performs weighted summation of the amplitudes of the three frequencies, it is possible to weaken the influence of the external ambient light interference, thereby making a judgment of approaching or moving away. In a preferred embodiment, the transmitting light circuit includes four or more transmitting light units, which respectively transmit light of different frequencies.

[0062] In addition, the weights can be adjusted according to actual needs to adapt to different application scenarios and object types. For example, in certain specific environments, certain frequencies of emitted light may be more susceptible to interference, and the impact of interference can be reduced by reducing the weights of these frequencies.

[0063] Different third and fourth thresholds may be set for different screen transmittances. In applications with relatively low screen transmittances, the third and fourth thresholds are set to relatively small values; in applications with relatively high screen transmittances, the third and fourth thresholds are set to relatively large values.

[0064] Please refer to Figure 7 , Figure 7 Schematic diagram of screen damage caused by different emission light configurations provided in an embodiment of the present application.

[0065] The first emission is Figure 8 The emitted light shown is emitted from a unique point under the screen. In this embodiment, a VCSEL emits light of 1 kHz frequency. Since this solution adopts distance detection based on frequency domain transformation, the intensity requirement of the emitted light is relatively low, which can reduce damage to the unique point under the screen.

[0066] The second emission is Fig. 9 As shown in the figure, four emission lights are emitted from four points under the screen respectively. In this embodiment, four 1 kHz frequency lights can be emitted through one or more VCSELs, and the intensity of each emission light can be further reduced, thereby further reducing damage to the screen.

[0067] The third emission light is Fig.10 As shown, four emitted lights are emitted from four points under the screen respectively, and the frequency of each emitted light is 0.5KHz, which further reduces the damage to the screen.

[0068] In some optional embodiments, the emitting light circuit includes a plurality of emitting light units, and the emitting light units emit light of different wavelength bands.

[0069] The digital control circuit of this embodiment is also used to: output a distance indication signal or a proximity indication signal according to the amplitude corresponding to the set frequency in the amplitude-frequency information, including: outputting a distance indication signal or a proximity indication signal according to the amplitude corresponding to the set frequency in the amplitude-frequency information of optical signals of different bands.

[0070] In an embodiment of the present application, the transmitting device uses a plurality of light sources of different wavelength bands, and correspondingly, the receiving device uses a plurality of photodiodes of corresponding wavelength bands, and these photodiodes can obtain optical signals corresponding to different wavelength bands. The optical signals of different wavelength bands are respectively converted into reflected light data of different wavelength bands. The reflected light data of different wavelength bands are respectively transformed in the frequency domain to obtain the amplitude-frequency information of different wavelength bands. According to the amplitude of the target frequency in the amplitude-frequency information of different wavelength bands, a distance indication signal or a proximity indication signal is output. This embodiment can further reduce the interference of ambient light by performing distance detection based on frequency domain changes on optical signals of different wavelength bands through multiple channels.

[0071] An intelligent device provided in an embodiment of the present application includes any of the above optical sensor chips.

[0072] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of the devices or units can be electrical, mechanical or other forms.

[0073] In addition, the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0074] Furthermore, the functional modules in the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

[0075] In this document, relational terms such as first and second, etc. are used merely to distinguish one entity or operation from another entity or operation, but do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0076] The above description is only an embodiment of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An optical sensor chip for distance detection, characterized in that: The optical sensor chip is arranged under the screen of the smart device, and the optical sensor chip comprises: an emitting optical circuit, a receiving optical circuit and a digital control circuit; the emitting optical circuit is connected to the digital control circuit, and the receiving optical circuit is connected to the digital control circuit; the emitting optical circuit and the receiving optical circuit are arranged close to the screen of the smart device; The emission light circuit is used to: emit emission light with set parameters; wherein the set parameters include a set frequency; The receiving optical circuit is used to: integrate the received light according to fixed stages to obtain an optical signal; and obtain a digital signal corresponding to each stage according to the optical signal; The digital control circuit is used to: group two adjacent stages, and in each group, subtract the digital signals of the two stages to obtain a reflected light data; perform frequency domain transformation on m reflected light data to obtain amplitude-frequency information; wherein m is a positive power of 2; and output a distance indication signal or a proximity indication signal according to the amplitude corresponding to the set frequency in the amplitude-frequency information.

2. The optical sensor chip according to claim 1, wherein: The emitting light circuit includes a plurality of emitting light units arranged at different positions, and the plurality of emitting light units emit emitting light of a set frequency and the same phase.

3. The optical sensor chip according to claim 1, wherein: The emitting light circuit includes a plurality of emitting light units arranged at different positions; the frequencies of the emitted lights of the plurality of emitting light units are all less than a set frequency, the phases of the emitted lights of the plurality of emitting light units are different, and the emitted lights of the plurality of emitting light units are equivalent to the emitted light of the set frequency after being superimposed.

4. The optical sensor chip according to any one of claims 1 to 3, characterized in that: The digital control circuit is also used for: If the amplitude corresponding to the set frequency in the amplitude-frequency information is greater than a second threshold, outputting a proximity indication signal; If the amplitude corresponding to the set frequency in the amplitude-frequency information is less than the first threshold, outputting a distance indication signal; The second threshold is greater than or equal to the first threshold.

5. The optical sensor chip according to claim 1, wherein: The emitting light circuit comprises n emitting light units arranged at different positions, and the n emitting light units emit emitting light of different frequencies.

6. The optical sensor chip according to claim 5, characterized in that: The digital control circuit is also used for: If the amplitudes corresponding to the n different frequencies in the amplitude-frequency information are all greater than their respective corresponding second thresholds, then a proximity indication signal is output; If the amplitudes corresponding to the n different frequencies in the amplitude-frequency information are all smaller than their respective corresponding first thresholds, a distance indication signal is output.

7. The optical sensor chip according to claim 5, characterized in that: The digital control circuit is also used for: The amplitudes corresponding to n different frequencies are weighted and summed to obtain an amplitude evaluation value; wherein the weights corresponding to different frequencies are positively correlated with the amplitudes of the corresponding emitted light; If the amplitude evaluation value is greater than a fourth threshold, outputting a proximity indication signal; If the amplitude evaluation value is less than a third threshold, outputting a distance indication signal; The fourth threshold is greater than or equal to the third threshold.

8. The optical sensor chip according to claim 1, wherein: The receiving optical circuit comprises: a photodiode, a programmable gain amplifier and an analog-to-digital converter connected in sequence; The photodiode is used to: integrate each stage of the optical signal to obtain the charge amount of each stage; wherein the length of the stage is the length of a single pulse; The programmable gain amplifier is used to: convert the charge amount in each stage into the voltage value in each stage; The analog-to-digital converter is used to convert the voltage value of each stage into the digital signal of each stage.

9. The optical sensor chip according to claim 1, wherein: The digital control circuit is also connected to the SRAM, the register module and the interrupt module; the register module is also connected to the power management module, the oscillator and the communication interface.

10. A smart device, characterized in that: The optical sensor chip comprises the optical sensor chip as claimed in any one of claims 1 to 9.

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