An optical sensor chip for distance detection and an intelligent device

Abstract

The present application provides an optical sensor chip and an intelligent device for distance detection. By performing frequency-domain transformation on multiple reflected light data, amplitude-frequency information is obtained. According to the amplitude corresponding to the set frequency in the amplitude-frequency information, the distance of the intelligent device is judged, where the set frequency is the frequency of the emitted light. In this embodiment, by only focusing on the amplitude of a specific frequency point, the interference light information of other frequencies in the environment is effectively shielded, the anti-interference ability of distance detection is improved, the information of the interaction between the emitted light and the object can be extracted more accurately, and thus the sensitivity of distance detection is improved. Moreover, due to the improvement of the anti-interference ability and sensitivity, the requirement for the intensity of the emitted light in this solution is reduced, which helps to reduce the power consumption and cost of the intelligent device.

Description

Technical Field

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

[0002] The optical distance sensor chip is an essential component in intelligent terminals such as mobile phones and tablets. In a smart phone, it is usually placed in the narrow slit position at the top of the phone screen or directly under the screen. The working principle of the optical distance sensor is as Figure 1 shown, and it works based on the infrared light reflection principle. When an object (such as a human face) approaches the sensor, the infrared light is reflected back and received by the sensor. By measuring the intensity of the reflected light, the distance between the object and the sensor is determined. When the distance is less than a certain set value, the sensor will trigger corresponding actions, such as turning off the screen. The application scenarios of the optical distance sensor chip include call anti-mis-touch, intelligent screen-on control, pocket mode, and mis-touch protection.

[0003] The distance detection function senses nearby objects through infrared emission and detection. The integration process is divided into two stages, as Figure 2 shown. In stage B, the background light is integrated. In stage A, the IR emitter emits infrared light, and at the same time, the reflected light is integrated. The integration in stage A includes the background light and the IR reflected light. By subtracting the results of the two-stage integration, the data of the reflected light, P_Data, is obtained. During a single distance detection process, the two integration stages are repeated multiple times, and the multiple results are accumulated as the final output, that is, P_DATA in formula (2). When P_DATA is greater than the upper limit value, it indicates that the object is far away; when P_DATA is less than the lower threshold value, it means that the object is approaching.

[0004] (1)

[0005] (2)

[0006] Since the light needs to pass through the screen twice, the loss is as high as 99%. Coupled with the interference of ambient light, the detection accuracy is not high. In order to improve the signal-to-noise ratio, certain requirements are imposed on the intensity of the infrared emitted light. However, long-term strong light irradiation on a single point will damage the screen and affect the screen life.

[0007] Moreover, the traditional detection method is easily affected by the screen light. To avoid the interference of the screen light, detection can only be performed during the period when the screen is not lit before the refresh of a new frame signal, and it is necessary to synchronize with the screen refresh signal Vsync. As Figure 3 shown, the VCSEL emission and circuit integration can only be carried out during a certain time period between two Vsync signals. Summary of the Invention

[0008] The purpose of the embodiments of the present application is to provide an optical sensor chip and an intelligent device for distance detection, so as to solve the problems that the existing optical distance sensing chips are greatly interfered by ambient light and screen light, and have relatively high requirements for the intensity of infrared emitted light.

[0009] An optical sensor chip for distance detection provided by the embodiments of the present application is disposed under the screen of the intelligent device. The optical sensor chip includes: a transmitting light circuit, a receiving light circuit, and a digital control circuit; the transmitting light circuit is connected to the digital control circuit, and the receiving light circuit is connected to the digital control circuit; the transmitting light circuit and the receiving light circuit are disposed close to the screen of the intelligent device.

[0010] The transmitting light circuit is configured to: emit transmitting light with set parameters under the screen of the intelligent device; wherein, the set parameters include a set frequency.

[0011] The receiving light circuit is configured to: receive light under the screen of the intelligent device, integrate the received light in fixed stages to obtain an optical signal; and obtain a digital signal corresponding to each stage according to the optical signal.

[0012] The digital control circuit is configured to: take two adjacent stages as a group, and in each group, subtract the digital signals of the two stages to obtain a reflected light data; perform a frequency-domain transformation on m reflected light data to obtain amplitude-frequency information; wherein, m is a positive power of 2; and output a far-away indication signal or a close indication signal according to the amplitude corresponding to the set frequency in the amplitude-frequency information.

[0013] Wherein, the far-away indication signal is used to indicate that the intelligent device is far away, and the close indication signal is used to indicate that the intelligent device is close.

[0014] In the above technical solution, by performing a frequency-domain transformation on multiple reflected light data to obtain amplitude-frequency information, and judging the distance of the intelligent device 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. In this embodiment, by only focusing on the amplitude of specific frequency points, the interference light information of other frequencies in the environment is effectively shielded, the anti-interference ability of distance detection is improved, the information of the interaction between the emitted light and the object can be extracted more accurately, thereby improving the sensitivity of distance detection. And, due to the improvement of the anti-interference ability and sensitivity, the requirements for the intensity of the emitted light in this solution are reduced, which helps to reduce the power consumption and cost of the intelligent device.

[0015] In some alternative embodiments, the transmitting light circuit includes a plurality of transmitting light units disposed at different positions, and the plurality of transmitting light units emit transmitting light with the set frequency and the same phase.

[0016] 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.

[0017] In some alternative embodiments, the emitted light circuit includes multiple emitted light units disposed at different positions; the frequencies of the emitted lights of the multiple emitted light units are all less than the set frequency, the phases of the emitted lights of the multiple emitted light units are different, and the emitted lights of the multiple emitted light units are superimposed to be equivalent to the emitted light of the set frequency.

[0018] In the above technical solution, multiple emitted lights with frequencies lower than the set frequency and different phases are used. These emitted lights are emitted from different positions under the screen, and the intensity and position of the emitted lights are dispersed to different positions under the screen, reducing the damage to a single point on the screen. After the multiple emitted lights with different phases are superimposed in space, an effect equivalent to that of the emitted light of the set frequency can be generated, thereby further reducing the damage to the screen by reducing the frequency of the emitted light while ensuring the detection effect.

[0019] In some alternative embodiments, the digital control circuit is further configured to:

[0020] Output a proximity indication signal or a distance indication signal according to the amplitude corresponding to the set frequency in the amplitude-frequency information:

[0021] If the amplitude corresponding to the set frequency in the amplitude-frequency information is greater than the second threshold, output a proximity indication signal;

[0022] If the amplitude corresponding to the set frequency in the amplitude-frequency information is less than the first threshold, output a distance indication signal;

[0023] Wherein, the second threshold is greater than or equal to the first threshold.

[0024] In the above technical solution, the first threshold is a relatively low amplitude threshold for determining whether the intelligent device is far from an object (or a 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 intelligent device and the object (or the human body) is relatively far. The second threshold is a relatively high amplitude threshold for determining whether the intelligent device is close to an object (or a 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 intelligent device and the object (or the human body) is relatively close, that is, the intelligent device is approaching the object (or the human body).

[0025] In some alternative embodiments, the emitted light circuit includes n emitted light units disposed at different positions, and the n emitted light units emit emitted lights with different frequencies.

[0026] In some alternative embodiments, the digital control circuit is further configured to:

[0027] Output a far - away indication signal or a close - by indication signal according to the amplitude value corresponding to the set frequency in the amplitude - frequency information:

[0028] If the amplitude values corresponding to n different frequencies in the amplitude - frequency information are all greater than their respective second thresholds, output a close - by indication signal;

[0029] If the amplitude values corresponding to n different frequencies in the amplitude - frequency information are all less than their respective first thresholds, output a far - away indication signal.

[0030] In the above - mentioned technical solution, during configuration, the emitted light of multiple frequency points is configured. Subsequently, in the threshold judgment step, only when the amplitude values corresponding to multiple frequency points are all greater than their respective second thresholds, is the intelligent device considered to be close - by, or when the amplitude values corresponding to multiple frequency points are all less than their respective first thresholds, is the intelligent device considered to be far - away. This further reduces the interference of specific - frequency flashing light 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 the flashing light, the emitted light of other frequencies can still provide accurate information. Only when the amplitude values of all frequencies are all greater than or all less than their respective thresholds, will a judgment of close - by or far - away be made. This embodiment provides a multi - frequency - point detection method, which improves the anti - interference ability and reliability of the system by increasing the redundancy of information. The multi - frequency - point detection method can also adjust the magnitudes of the frequencies and thresholds according to actual needs to adapt to different application scenarios and object types.

[0031] In some alternative embodiments, the digital control circuit is further configured to:

[0032] Output a far - away indication signal or a close - by indication signal according to the amplitude value corresponding to the set frequency in the amplitude - frequency information:

[0033] Perform a weighted sum of the amplitude values corresponding to n different frequencies to obtain an amplitude evaluation value; among them, the weights corresponding to different frequencies are positively correlated with the amplitudes of the corresponding emitted light;

[0034] If the amplitude evaluation value is greater than the fourth threshold, output a close - by indication signal;

[0035] If the amplitude evaluation value is less than the third threshold, output a far - away indication signal;

[0036] Among them, the fourth threshold is greater than or equal to the third threshold.

[0037] In the above technical solution, during configuration, multiple frequency points of transmitted light are configured. Subsequently, in the 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 transmitted light, that is, the larger the amplitude of the transmitted light, the larger its corresponding weight. This weighting method can ensure that in the summation process, the frequencies that contribute more to the detection have a greater influence. In different application scenarios, the frequency of the transmitted light and the single emission intensity 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 intelligent device is approaching the object. If the amplitude evaluation value is less than the third threshold, it is considered that the intelligent device is moving away from the object. In this embodiment, through the method of weighted summation, the reflected light signal intensities of all frequencies can be more comprehensively considered, so as to more accurately reflect the distance change between the intelligent device and the object. Since the transmitted light of different frequencies may be affected by the environment to different degrees, the method of weighted summation can reduce the impact of a single frequency being severely interfered on the overall judgment and improve the robustness of the system.

[0038] In addition, the weight can be adjusted according to actual needs to adapt to different application scenarios and object types. For example, in some specific environments, the transmitted light of certain frequencies may be more easily interfered. At this time, the influence of interference can be reduced by reducing the weights of these frequencies.

[0039] For different screen transmittances, different third thresholds and fourth thresholds can be set. In applications with a relatively low screen transmittance, the third threshold and the fourth threshold are set to smaller values; in applications with a relatively high screen transmittance, the third threshold and the fourth threshold are set to larger values.

[0040] In some alternative embodiments, the received light circuit includes: a photodiode, a programmable gain amplifier, and an analog-to-digital converter connected in sequence;

[0041] The photodiode is used to: integrate each stage in the optical signal respectively to obtain the charge amount of each stage; wherein, the length of the stage is the length of a single pulse;

[0042] The programmable gain amplifier is used to: convert the charge amount of each stage into the voltage value of each stage respectively;

[0043] The analog-to-digital converter is used to: convert the voltage value of each stage into the digital signal of each stage respectively.

[0044] In the above technical solution, after the integration stage ends, the charge output by the photodiode represents the intensity of the optical signal. To convert this charge into an analog voltage signal 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.

[0045] The analog voltage signal amplified by the PGA is sent to an analog-to-digital converter (ADC) for digital processing. 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 a more refined analysis and processing of the optical signal.

[0046] Subsequently, in the digital control circuit, adjacent two stages are grouped as a set. In each set, the digital signals of the two stages are subtracted to obtain a reflected light data. Among them, the two stages in each set may be two background light integration stages, or one background light integration stage and one reflected light integration stage. The background light integration stage is when the transmitting light is not emitted and the receiving device receives the background light. At this time, the received optical signal is integrated to obtain the charge amount of the background light integration stage. The reflected light integration stage is when the transmitting light is emitted and the receiving device receives the background light and the reflected light. At this time, the received optical 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 adjacent integration stages are subtracted, that is, the influence of the background light on the measurement of the reflected light is eliminated, and the reflected light data is extracted. The magnitude of the reflected light data reflects the reflection intensity of the target object on the transmitting light, and thus can be used to judge the distance between the intelligent device and the target object.

[0047] In some alternative embodiments, the digital control circuit is also connected to a data storage unit, a register module, and an interrupt module; the register module is also connected to a power management module, an oscillator, and a communication interface.

[0048] Among them, the register module is used to manage the configuration and the working state of the chip;

[0049] The interrupt module is used to report special events, such as approaching, moving away, data anomalies, etc.;

[0050] The oscillator is used to generate an internal working clock.

[0051] An intelligent device provided by an embodiment of the present application includes a light sensor chip as described in any of the above. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required to be used in the embodiments of the present application. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation of the scope. For those of ordinary skill in the art, without creative efforts, other relevant drawings can also be obtained based on these drawings.

[0053] Figure 1 Schematic diagram of the working principle of the optical distance sensing chip;

[0054] Figure 2 Schematic diagram of the integration process of the optical distance sensing chip;

[0055] Figure 3 Timing diagram of VCSEL emission and Vsync signal;

[0056] Figure 4 Functional module diagram of an optical sensor chip for distance detection provided by an embodiment of the present application;

[0057] Figure 5 Schematic diagram of the circuit structure of the optical sensor chip provided by an embodiment of the present application;

[0058] Figure 6 Schematic diagram of the integration process of the distance detection method provided by an embodiment of the present application;

[0059] Figure 7 Schematic diagram of the damage to the screen by different emission light configurations provided by an embodiment of the present application;

[0060] Figure 8 The first emission light waveform diagram provided by an embodiment of the present application;

[0061] Figure 9 The second emission light waveform diagram provided by an embodiment of the present application;

[0062] Figure 10 The third emission light waveform diagram provided by an embodiment of the present application;

[0063] Figure 11 Schematic diagram of the structure of the optical sensor chip provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0064] The following will describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application.

[0065] Please refer to Figure 4 ,Figure 4 This is a functional block diagram of an optical sensor chip for distance detection provided by an embodiment of the present application. The optical sensor chip is disposed under the screen of the smart device. The optical sensor chip includes: 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 disposed close to the screen of the smart device.

[0066] Among them, the transmitting optical circuit is configured to: transmit transmitting light with set parameters under the screen of the smart device; wherein, the set parameters include a set frequency. The receiving optical circuit is configured to: receive light under the screen of the smart device, integrate the received light in fixed phases to obtain an optical signal; and obtain a digital signal corresponding to each phase according to the optical signal. The digital control circuit is configured to: take two adjacent phases as a group, and in each group, subtract the digital signals of the two phases to obtain a reflected light data; perform a frequency domain transformation on m reflected light data to obtain amplitude-frequency information; wherein, m is a positive power of 2; and output a far-away indication signal or a close-by indication signal according to the amplitude corresponding to the set frequency in the amplitude-frequency information. Among them, the far-away indication signal is used to indicate that the smart device is far away, and the close-by indication signal is used to indicate that the smart device is close by.

[0067] In the embodiment of the present application, amplitude-frequency information is obtained by performing a frequency domain transformation on multiple reflected light data, 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 transmitting 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, can more accurately extract the information of the interaction between the transmitting light and the object, thereby improving the sensitivity of distance detection. Moreover, due to the improvement of the anti-interference ability and sensitivity, the requirement for the intensity of the transmitting light in this solution is reduced, which helps to reduce the power consumption and cost of the smart device.

[0068] In some optional embodiments, the receiving optical circuit includes: a photodiode, a programmable gain amplifier, and an analog-to-digital converter connected in sequence;

[0069] Among them, the photodiode is configured to: integrate each phase in the optical signal respectively to obtain the charge amount of each phase; wherein, the length of the phase is the length of a single pulse. The programmable gain amplifier is configured to: convert the charge amount of each phase into the voltage value of each phase respectively. The analog-to-digital converter is configured to: convert the voltage value of each phase into the digital signal of each phase respectively.

[0070] In the embodiments of the present application, after the integration stage ends, the amount of charge output by the photodiode represents the intensity of the optical signal. To convert this amount of charge into an analog voltage signal 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.

[0071] The analog voltage signal amplified by the PGA is sent to an analog-to-digital converter (ADC) for digital processing. The resolution of the ADC determines the accuracy of the converted digital signal. A high-resolution ADC can provide a more accurate digital signal, thus allowing for a more refined analysis and processing of the optical signal.

[0072] Subsequently, in the digital control circuit, two adjacent stages are grouped as a set. In each set, the digital signals of the two stages are subtracted to obtain a reflected light data. Among them, the two stages in each set may be two background light integration stages, or one background light integration stage and one reflected light integration stage. The background light integration stage is when the transmitting light is not emitted and the receiving device receives the background light. At this time, the received optical signal is integrated to obtain the amount of charge in the background light integration stage. The reflected light integration stage is when the transmitting light is emitted and the receiving device receives the background light and the reflected light. At this time, the received optical signal is integrated to obtain the amount of charge in the reflected light integration stage. The amount of charge in the background light integration stage is converted into a background light digital signal, and the amount of charge in 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 adjacent integration stages are subtracted, that is, the influence of the background light on the measurement of the reflected light is eliminated, and the reflected light data is extracted. The magnitude of the reflected light data reflects the reflection intensity of the target object on the transmitting light, and thus can be used to judge the distance between the intelligent device and the target object.

[0073] The optical sensor chip of one or more of the above embodiments can be packaged as a chip as shown in Figure 11 This chip of this embodiment has 4 transmitting light units, and a light isolation component is provided between the 4 transmitting light units and the receiving optical circuit.

[0074] Please refer to Figure 5 , Figure 5 which is a schematic diagram of the circuit structure of the optical sensor chip provided by the embodiments of the present application.

[0075] In some alternative embodiments, the digital control circuit is also connected to a data storage unit, a register module, and an interrupt module; the register module is also connected to a power-on reset (POR) module, an oscillator (OSC), and a communication interface.

[0076] Among them, the register module is used to manage configurations and the chip operating state; the interrupt module is used to report special events, such as approaching, moving away, and data anomalies; the oscillator is used to generate an internal operating clock.

[0077] In this embodiment, the data storage unit is SRAM, and SRAM is also connected to the register; the communication interface is an I2C Slave; among them, SRAM is short for Static Random-Access Memory, which is an important type of computer memory; I2C Slave (also known as IIC Slave) is a role in the I2C (Inter-Integrated Circuit, two-wire serial bus) communication protocol, corresponding to the I2C Master (master device).

[0078] The light-emitting unit of this embodiment includes an overcurrent protection circuit, a light-emitting drive circuit, a laser (Laser), and a zener 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 drive current for the laser to generate a stable light output. The laser (Laser) converts an electrical signal into an optical signal. The zener diode (ZD) is used to stabilize the power supply voltage and protect the circuit from voltage fluctuations. The zener diode has a special reverse breakdown characteristic. When the reverse voltage reaches a certain value, reverse breakdown occurs, at which time the current increases sharply, but the voltage remains basically unchanged. This characteristic enables the zener diode to provide a stable voltage output in the circuit.

[0079] The optical sensor chip of this embodiment further includes OTP (One-Time Programmable) for adjusting circuit parameters according to the measured results.

[0080] Please refer to Figure 6 , Figure 6Schematic diagram of the integration process of the distance detection method provided by the embodiment of the present application. The emitted light VCSEL_ON in this embodiment has two frequency points. The P1 group includes a background light integration stage B1 and a reflected light integration stage A1. The P2 group includes a background light integration stage B2 and a reflected light integration stage A2. The P3 group includes a background light integration stage 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:

[0081]

[0082] Among them, is the digital signal in the Ai stage, is the digital signal in the Bi stage.

[0083] Subsequently, perform FFT frequency domain transformation on That is: FFT_output = abs(fft(P_Data)).

[0084] In some optional embodiments, the emitted light circuit includes a plurality of emitted light units arranged at different positions. The plurality of emitted light units emit emitted light with a set frequency and the same phase.

[0085] In the embodiment of the present application, a plurality of emitted lights with a set frequency 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 light, the damage to a single point on the screen is reduced, and at the same time, the accuracy and reliability of distance detection are ensured.

[0086] In some optional embodiments, the emitted light circuit includes a plurality of emitted light units arranged at different positions; the frequencies of the emitted light of the plurality of emitted light units are all less than the set frequency, the phases of the emitted light of the plurality of emitted light units are different, and the emitted light of the plurality of emitted light units is equivalent to the emitted light with the set frequency after superposition.

[0087] In the embodiment of the present application, a plurality of emitted lights with a frequency lower than the set frequency and different phases are used. These emitted lights are emitted from different positions under the screen. The intensity and position of the emitted light are dispersed to different positions under the screen, reducing the damage to a single point on the screen. After the plurality of emitted lights with different phases are superposed in space, an effect equivalent to the emitted light with the set frequency can be generated, so that while ensuring the detection effect, the damage to the screen is further reduced by reducing the frequency of the emitted light.

[0088] In some alternative embodiments, the digital control circuit is further configured to: output a proximity indication signal or a distance 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 a second threshold, a proximity indication signal is output. If the amplitude corresponding to the set frequency in the amplitude-frequency information is less than a first threshold, a distance indication signal is output. Wherein, the second threshold is greater than or equal to the first threshold.

[0089] In the embodiments of the present application, the first threshold is a relatively low amplitude threshold, which is used to determine whether the intelligent device is far from an object (or a 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 intelligent device and the object (or the human body) is relatively far. The second threshold is a relatively high amplitude threshold, which is used to determine whether the intelligent device is close to an object (or a 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 intelligent device and the object (or the human body) is relatively close, that is, the intelligent device is approaching the object (or the human body).

[0090] In some alternative embodiments, the transmitting light circuit includes n transmitting light units disposed at different positions, and the n transmitting light units emit transmitting light of different frequencies.

[0091] In some alternative embodiments, the digital control circuit is further configured to: output a proximity indication signal or a distance indication signal according to the amplitude corresponding to the set frequency in the amplitude-frequency information. If the amplitudes corresponding to the n different frequencies in the amplitude-frequency information are all greater than their respective second thresholds, a proximity indication signal is output. If the amplitudes corresponding to the n different frequencies in the amplitude-frequency information are all less than their respective first thresholds, a distance indication signal is output.

[0092] In the embodiments of the present application, during configuration, transmitting light of multiple frequency points is configured. In the subsequent threshold judgment step, only when the amplitudes corresponding to multiple frequency points are all greater than their respective second thresholds, it is considered that the intelligent device is approaching, or when the amplitudes corresponding to multiple frequency points are all less than their respective first thresholds, it is considered that the intelligent device is far away, further reducing the interference of specific frequency flashing light in the environment. Among them, these thresholds can be the same or different. Because even if the transmitting light of a certain frequency is interfered by the flashing light, the transmitting 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 far away will be made. This embodiment provides a multi-frequency point detection method, which improves the anti-interference ability and reliability of the system by increasing the redundancy of information. The multi-frequency point detection method can also adjust the frequency and threshold sizes according to actual needs to adapt to different application scenarios and object types.

[0093] In some alternative embodiments, the digital control circuit is further configured to: output a proximity indication signal or a distance indication signal according to the amplitude corresponding to the set frequency in the amplitude-frequency information; perform a weighted sum of the amplitudes corresponding to n different frequencies to obtain an amplitude evaluation value, where 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, output a proximity indication signal; if the amplitude evaluation value is less than a third threshold, output a distance indication signal, where the fourth threshold is greater than or equal to the third threshold.

[0094] In the embodiments of the present application, during configuration, multiple frequency points of emitted light are configured. Subsequently, in the threshold judgment step, a weighted sum of the amplitudes corresponding to n different frequencies is performed to obtain an amplitude evaluation value. Here, the weights are determined according to the amplitudes of the corresponding emitted light, that is, the greater the amplitude of the emitted light, the greater the corresponding weight. This weighting method can ensure that in the summation process, the frequencies that contribute more to the detection have a greater influence. The frequency of the emitted light and the intensity of single emission 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 intelligent device is approaching the object. If the amplitude evaluation value is less than the third threshold, it is considered that the intelligent device is moving away from the object. Through the method of weighted summation in this embodiment, the intensity of the reflected light signals of all frequencies can be more comprehensively considered, so as to more accurately reflect the distance change between the intelligent device and the object. Since the emitted light of different frequencies may be affected by the environment to different degrees, the method of weighted summation can reduce the impact of a single frequency being severely interfered on the overall judgment and improve the robustness of the system.

[0095] Specifically, the emitted light circuit may include 2 emitted light units, and these 2 emitted light units emit emitted light of different frequencies. The emitted light circuit may also include 3 emitted light units, and these 3 emitted light units emit emitted light of different frequencies. Even if the received light of one of the frequencies is interfered by external ambient light, since this solution comprehensively performs a weighted sum of the amplitudes of 3 frequencies, the influence of external ambient light interference can be weakened, so as to perform proximity or distance judgment. In a preferred embodiment, the emitted light circuit includes 4 or more emitted light units, and these emitted light units respectively emit emitted light of different frequencies.

[0096] 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, the emitted light of certain frequencies may be more easily interfered. At this time, the influence of interference can be reduced by decreasing the weights of these frequencies.

[0097] For different screen transmittances, different third thresholds and fourth thresholds can be set. In applications with relatively low screen transmittance, the third threshold and the fourth threshold are set to smaller values; in applications with relatively high screen transmittance, the third threshold and the fourth threshold are set to larger values.

[0098] Please refer to Figure 7 , Figure 7 which is a schematic diagram of the damage to the screen caused by different emission light configurations provided by the embodiments of the present application.

[0099] The first type of emission light is Figure 8 the emission light shown in the figure. This emission light is emitted from a single point under the screen. In this embodiment, a VCSEL emits light with a frequency of 1 kHz. Since this solution uses distance detection based on frequency domain transformation, the requirement for the intensity of the emission light is relatively low, which can reduce the damage to the single point under the screen.

[0100] The second type of emission light is Figure 9 the emission light shown in the figure, which emits 4 emission lights from four points under the screen respectively. In this embodiment, one or more VCSELs can be used to emit four lights with a frequency of 1 kHz. The intensity of each emission light can be further reduced, thereby further reducing the damage to the screen.

[0101] The third type of emission light is Figure 10 the emission light shown in the figure, which emits 4 emission lights from four points under the screen respectively. The frequency of each emission light is 0.5 kHz, which further reduces the damage to the screen.

[0102] In some alternative embodiments, the emission light circuit includes multiple emission light units that emit emission lights of different bands.

[0103] The digital control circuit of this embodiment is further configured to: output a far-away indication signal or a close indication signal according to the amplitude corresponding to the set frequency in the amplitude-frequency information, including: outputting a far-away indication signal or a close indication signal according to the amplitude corresponding to the set frequency in the amplitude-frequency information of the optical signal of different bands.

[0104] In the embodiments of the present application, the emission device uses multiple light sources of different bands. Correspondingly, the receiving device uses multiple photodiodes of corresponding bands, and these photodiodes can obtain optical signals corresponding to different bands. The optical signals of different bands are respectively converted into reflected light data of different bands. The reflected light data of different bands are respectively subjected to frequency domain transformation to obtain amplitude-frequency information of different bands. According to the amplitude of the target frequency in the amplitude-frequency information of different bands, a far-away indication signal or a close indication signal is output. In this embodiment, distance detection based on frequency domain change is simultaneously performed on optical signals of different bands through multiple channels, which can further reduce the interference of ambient light.

[0105] An intelligent device provided by the embodiments of the present application includes an optical sensor chip as described in any one of the above.

[0106] 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 illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For another 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 displayed or discussed coupling or direct coupling or communication connection between each other can be through some communication interfaces. The indirect coupling or communication connection of the devices or units can be in an electrical, mechanical or other form.

[0107] In addition, the units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0108] Furthermore, in each embodiment of the present application, the functional modules can be integrated together to form an independent part, or each module can exist alone, or two or more modules can be integrated to form an independent part.

[0109] In this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0110] The above are only the embodiments of the present application and are not used to limit the protection scope of the present application. For those skilled in the art, the present application can have various changes and modifications. 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 disposed under the screen of the smart device. The optical sensor chip includes: a transmitting light circuit, a receiving light circuit, and a digital control circuit; the transmitting light circuit is connected to the digital control circuit, and the receiving light circuit is connected to the digital control circuit; the transmitting light circuit and the receiving light circuit are disposed close to the screen of the smart device; The transmitting light circuit is configured to: transmit transmitting light with set parameters; wherein, the set parameters include a set frequency; The receiving light circuit is configured to: integrate the received light in 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 configured to: take two adjacent stages as a group, and in each group, subtract the digital signals of the two stages to obtain a reflected light data; perform a frequency domain transformation on m reflected light data to obtain amplitude-frequency information; wherein, m is a positive power of 2; output a far-away indication signal or a close indication signal according to the amplitude corresponding to the set frequency in the amplitude-frequency information; The transmitting light circuit includes a plurality of transmitting light units disposed at different positions; the frequencies of the transmitting light of the plurality of transmitting light units are all less than the set frequency, the phases of the transmitting light of the plurality of transmitting light units are different, and the transmitting light of the plurality of transmitting light units is equivalent to the transmitting light of the set frequency after being superimposed.

2. The optical sensor chip according to claim 1, wherein The transmitting light circuit includes a plurality of transmitting light units disposed at different positions, and the plurality of transmitting light units transmit transmitting light with the set frequency and the same phase.

3. The optical sensor chip according to any one of claims 1-2, characterized in that, The digital control circuit is further configured to: If the amplitude corresponding to the set frequency in the amplitude-frequency information is greater than a second threshold, output a close indication signal; If the amplitude corresponding to the set frequency in the amplitude-frequency information is less than a first threshold, output a far-away indication signal; Wherein, the second threshold is greater than or equal to the first threshold.

4. The optical sensor chip according to claim 1, wherein, The transmitting light circuit includes n transmitting light units disposed at different positions, and the n transmitting light units transmit transmitting light with different frequencies.

5. The optical sensor chip according to claim 4, characterized in that, The digital control circuit is further configured to: If the amplitudes corresponding to the n different frequencies in the amplitude-frequency information are all greater than their respective second thresholds, output a close indication signal; If the amplitudes corresponding to the n different frequencies in the amplitude-frequency information are all less than their respective first thresholds, output a far-away indication signal.

6. The optical sensor chip according to claim 4, wherein, The digital control circuit is further configured to: Perform a weighted sum of the amplitudes corresponding to the n different frequencies to obtain an amplitude evaluation value; wherein, the weights corresponding to the different frequencies are positively correlated with the amplitudes of the corresponding transmitting light; If the amplitude evaluation value is greater than a fourth threshold, output a close indication signal; If the amplitude evaluation value is less than a third threshold, output a far-away indication signal; Wherein, the fourth threshold is greater than or equal to the third threshold.

7. The optical sensor chip according to claim 1, characterized in that The receiving light circuit includes: a photodiode, a programmable gain amplifier, and an analog-to-digital converter connected in sequence; The photodiode is configured to: integrate each stage in the optical signal respectively 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 configured to: convert the charge amount of each stage into a voltage value of each stage respectively; The analog-to-digital converter is used to: convert the voltage value of each stage into a digital signal of each stage respectively.

8. The optical sensor chip according to claim 1, characterized in that The digital control circuit is further connected to the SRAM, the register module and the interrupt module; the register module is further connected to the power management module, the oscillator and the communication interface.

9. An intelligent device, characterized in that, It includes the optical sensor chip according to any one of claims 1-8.

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