OPTICAL PROXIMITY SENSOR

Abstract

Optical proximity sensor (2), comprising • an infrared light transmitter (6) configured to emit alternating current pulses of infrared light, the infrared light transmitter (6) further configured to emit no or only a small amount of infrared light between the alternating current pulses; • a light detector (10) configured to detect DC signals of ambient light and AC pulses of infrared light emitted by the light transmitter (6) and reflected by an object to be detected in the direction of the light detector (10), and • an integrator circuit (14) which carries out a distance measurement using the light transmitter (6) and the light detector (10), wherein the integrator circuit (14) comprises an ambient light measurement circuit (16) configured to perform an ambient light measurement before performing a distance measurement, and to configure measurement settings of the light transmitter (6) and / or the light detector (10) and / or the integrator circuit (14) based on the ambient light measurement, and wherein the integrator circuit (14) is configured to perform the distance measurement based on the measurement settings.

Description

Technical Field of the DisclosureThe field of the invention relates to proximity sensors using, for example, an IR transmitter (typically an LED or VCSEL), a receiver (photodiode), an analog front end (AFE), an ADC, and digital processing circuitry. The invention relates in particular to an optical proximity sensor comprising an infrared light emitter configured to emit pulses of alternating current of infrared light, the infrared light emitter further configured to emit no or only a small amount of infrared light between the pulses of alternating current, and further comprising a light detector configured to detect direct current signals of the ambient light and alternating current pulses of infrared light emitted by the light emitter and reflected by an object to be detected towards the light detector, and further comprising an integrator circuit performing an proximity measurement using the light emitter and the light detector.BackgroundPrior art proximity sensors consist of at least two main blocks. One of them performs the subtraction of the ambient light, which is done in the analog domain from a particular block, typically a current DAC, which estimates the ambient light before the beginning of each proximity measurement and subtracts it during the proximity measurement process. Another important block consists of a voltage DAC used for crosstalk compensation (CT). The crosstalk is also estimated before the proximity measurement and a corresponding DAC code is stored in the digital part.The residual ambient light (after the subtraction mentioned above) is deleted from the approximation circuit itself during the measurement cycle. To remove the residual ambient light and compensate for crosstalk, the proximity measurement is performed in two phases - one with IR transmitter turned off to measure the ambient light (A) and the second with IR transmitter turned on to measure the reflected signal (due to transmitter turned on) + ambient light (S+A). The effective approximation signal is calculated as P=(S+A)-(A). During this two-stage process, the CT DAC code is used to perform crosstalk compensation and generate an effective approximation signal (P'), from which the ambient light is subtracted and the crosstalk compensated. This signal is amplified with a switched cap circuit and two amplifiers - the first and the second stage. Finally, the amplified voltage is passed to an ADC for the digital version.The most important disadvantages of the conventional proximity sensors described above are essentially as follows: they require a digital-to-analog converter (DAC) for subtracting the ambient current. The DAC contributes to shot noise. The first and second stages amplify this noise by their respective gain. Also, a single adjustment of the IR transmit power and receiver is used for all light zones. The adjustment generally has a high IR transmission power in order to meet the requirements for the approach power at brightest lighting conditions. This is not optimal for OLED applications, since a higher transmission power leads to visible screen distortions in poor lighting conditions. In addition, the IR transmitter is unnecessarily overdriven in poor lighting conditions, which make up the majority of the operating time of the device, which leads to a higher average power consumption.U.S. Pat. No. 9,608,132 B2 discloses an optical sensor arrangement and a method for generating an analog output signalThe document US 2014 / 0252212 A1 describes a signal processing circuit for a light sensor, a sensor arrangement and a method for signal processing for a light sensor.Document U.S. Pat. No. 8,692,200 B2 discloses an optical proximity sensor with improved dynamic range and sensitivity.Document EP 3 425 802 A1 describes a proximity sensor with crosstalk compensation comprising a transmitting circuit for transmitting a signal to be reflected at a target and an interfering object and a receiving circuit for receiving a reflected signal having a payload component and a noise component.SummaryIt is therefore the object of the invention to provide an improved proximity sensor which overcomes the disadvantages of known proximity sensors. A further object of the invention is to provide a corresponding method for carrying out approximation measurements.With respect to the proximity sensor, the object of the invention is achieved by a proximity sensor according to claim 1. According to the invention, the integrator circuit comprises an ambient light measurement circuit which is configured to perform an ambient light measurement before carrying out an approximation measurement and to configure measurement settings of the light transmitter and / or of the light detector and / or of the integrator circuit on the basis of the ambient light measurement, and wherein the integrator circuit is configured to perform the approximation measurement on the basis of these measurement settings.Preferred embodiments of the invention are set forth in the dependent claims and in the specification.The invention is based on the consideration that there is a need for proximity sensors with low current consumption but high accuracy in the determination of the approach information.The Applicant has found that these requirements can be met by an ambient light detection proximity sensor in which the components are configured in dependence on the sensed ambient light. In this way, if necessary, an optimized configuration for the proximity measurement can be configured, wherein at the same time the power consumption and possible artifacts on a display are reduced. To this end, a high-precision ambient light measurement mode is incorporated into the entire approach measurement routine.Preferably, the integrator circuit is configured to perform approximation measurements in cycles, the ambient light measurement circuit being configured to perform ambient light measurement at the beginning of each cycle. In this way, each approximation measurement can be performed under the current or current ambient light conditions, enabling an optimized adaptive measurement. Based on the ambient light, the system adjusts the transmit power to reduce screen distortion and power consumptionAdvantageously, the measurement settings are configured based on the measured ambient light intensity / level. Based on the ambient light, the system selects the gain and number of PD sections to achieve the best SNR (signal-to-noise ratio)In a preferred embodiment, a plurality of ambient light intensity ranges or zones are defined, wherein for each intensity range, associated measurement settings are defined in the integrator circuit, and wherein the integrator circuit is configured to select the associated measurement settings based on the intensity range comprising / comprising the measured ambient light intensity. In this way, adjustment of the proximity sensor settings may be discretized into multiple discrete settings that may be selected depending on the measured ambient light intensity. By selecting the transmitter and receiver settings, reduced / no screen distortion, lower power consumption, and optimum SNR are achieved.Preferably, multiple zones are defined based on the total current of the light detector, specifically constructed as a photodiode (PD), which is a function of ambient light, crosstalk, and dark current. Each zone has independent software programmable settings for configuring transmitter power and receiver circuit parameters.Preferably, between 3 and 10, in particular 5, intensity ranges are definedAdvantageously, the power of the light transmitter is adjusted as a measurement setting during the proximity measurement as a function of the ambient light intensity.Preferably, as at least one measurement setting, at least one parameter of the light detector is set as a function of the ambient light intensity, in particular the number of PD (photodiode) sections. Depending on the ambient light intensity measured, the sensitivity of the detected light can be attenuated or increased by selecting the number of PD sections. Further parameters are the electrical amplification and / or the integration time.As a measurement setting, the amplification factor of the integrator circuit is advantageously set as a function of the ambient light intensity.In a preferred embodiment, the integrator circuit comprises an operational amplifier and a capacitor array having a plurality of capacitors electrically arranged in parallel with the operational amplifier, the integrator circuit being configured to select a parallel capacitor of the capacitor array depending on the measured ambient light intensity during the proximity measurement. The capacitor array preferably includes a number of capacitors at least as large as the number of ambient light intensity ranges. Depending on the ambient light intensity measured, the capacitor corresponding to the range comprising this measurement value can be selected in parallel with the operational amplifier.The circuitry for measuring ambient light is preferably substantially identical to the integrator circuitry. The proximity sensor measures the IR ambient light level without additional circuitry prior to each proximity measurement and automatically configures the optimal settings for the proximity sensor based on the total photodiode (PD) currentIn a preferred embodiment, the proximity sensor comprises a circuit for measuring crosstalk, which circuit is preferably implemented in a digital core. The crosstalk measurement circuit is configured to measure the infrared light emitted from the light transmitter by the light detector in a state without a target object, i.e., when an object is not present in the vicinity of the proximity sensor.The non-target condition is determined by the application and not by the device. For this purpose, the application / user initiates a crosstalk measurement by software command. For example, the smartphone may lie flat on a surface and no call is made. No acceleration is measured. Depending on various sensor data, the non-target state may be detected. When a call is incoming, the non-destination state may be terminated.The optical proximity sensor preferably comprises an ADC, wherein the outputs of the measured ambient light and crosstalk measurements are converted into digital signals in the ADC, and wherein a digital core is configured to perform ambient light and crosstalk corrections of the digitized proximity measurement signal. Ambient, approximation and crosstalk signals are only digitized by the ADC. The crosstalk corrections and the further processing are carried out by a digital core which is constructed, for example, as a microcontroller / CPU / digital circuit. Crosstalk compensation is performed in this digital core. This is a simple arithmetic in which the stored CT-PDATA is subtracted from the PDATA. The CT compensated PDATA are output for further processing.Preferably, crosstalk calibration coefficients are stored in the digital core, which are applied during crosstalk correction based on the measured crosstalk signal. This enables adaptive switching of the crosstalk compensation value based on normalized non-target output data.The optical proximity sensor is advantageously configured to provide normalized proximity data as an output. The final proximity data is advantageously normalized based on the selected configuration setting to generate a consistent proximity response across all ambient light zones for a target distance. The normalized approximation data based on the selected transmitter and receiver configuration settings is thus used to generate a consistent approximation response for the entire light detector / PD stream that includes all ambient light zones. In this way, a very reliable and robust output signal is generated, which can be used, for example, by the control unit of a smartphone for switching the display on and off.In a preferred embodiment, the light detector is designed as a photodiode. The intensity or added intensities of ambient light, reflected light, and cross-talk light result in a particular photodiode current that can be further processed. Adaptively switching transmitter power and receiver parameters based on total photodiode (PD) current, which is a function of ambient light, crosstalk, and dark current of the PD in an approach detection application.The light emitter is preferably embodied as an LED or VCSEL. A light emitter in the form of an LED is less expensive compared to a VCSEL. However, the incident field (FOI) of LEDs is broader compared to VCSELs, which leads to undesirable crosstalk. An LED requires a much higher current to provide the same optical power as a VCSEL. In most applications, VCSELs are preferred over LEDsWith respect to the method, the article is solved by the following steps:• in an integrator circuit, performing an approximation measurement by emitting AC infrared radiation by an infrared transmitter and measuring the reflected radiation by a light detector;• Carrying out an ambient light measurement, whereinthe ambient light measurement is performed prior to the proximity measurement, and wherein the infrared transmitter and / or the light detector and / or the integrator circuit are configured for the proximity measurement based on the ambient light measurement, in particular based on the ambient light intensity.Preferably, a plurality of ambient light intensity ranges is defined, wherein for each intensity range respective measurement settings are defined in the integrator circuit and wherein the measurement settings are selected based on the intensity range comprising / comprising the measured ambient light intensity.The advantages of the invention lie in particular in the following points. By adaptively switching the IR radiator power, the distortions caused by the IR radiation are reduced on the display. In particular in the case of OLED displays, regions illuminated by IR radiation lead to black spots which are visible to the user. By detecting the ambient light and adjusting the sensor according to this measurement, an optimum power approach response is generated for each lighting condition, thereby avoiding waste of excess power in poor lighting conditions and thus reducing the average power.Noise in the analog front end is reduced by the omission of "analog ambient light detection" and "crosstalk correction", since these routines are performed in the digital domain. The digital implementation of the environment and crosstalk compensation improves the accuracy and resolution. The proximity sensor has a low noise analog front end because the analog circuitry "analog ambient light detection" and "crosstalk correction" is omitted.The digital implementation of the environment and crosstalk compensation improves the accuracy and resolution. Since the ambient light subtraction and crosstalk compensation are performed fully digitally, the need for analog circuitry to perform these two operations is eliminated and noise is thus reduced. The final digital environment and crosstalk compensated proximity data is normalized based on the selected transmitter and receiver configuration settings to generate a consistent proximity response across all ambient light zones for a target distance.With the described approach of the differential circuit arrangement, a very precise proximity sensor is realized. It helps to provide an absolutely distortion-free intensity-based solution behind OLED proximity detection. Normalized constant resolution approximation data is provided across all configuration settings of the device.The described proximity sensor can be used, for example, as a BOLT proximity sensor or as a proximity sensor with a large air gap.Brief Description of the Preferred EmbodimentsA preferred embodiment of the invention is explained in conjunction with a schematic drawing. In this drawing, FIG. 1 shows an optical proximity sensor in a preferred embodiment; FIG. 2 is a flow chart of the approach measurement scheme in a preferred embodiment; and FIG. 3 is a flow chart for ambient light detection.Identical components are provided with the same reference numbers.Detailed Description of the Preferred EmbodimentsThe proximity sensor 2 schematically illustrated in FIG. 1 comprises a light transmitter 6 in the form of a VCEL, which emits light in the infrared range, and a light detector 10, which is designed as a photodiode (PD). The proximity sensor 2 further includes an integrator circuit 14, a unit 20, a multiplexer 24, an ADC (analog-to-digital converter) 28, and a logic unit 32.The block or unit 20 shown in Fig. 1 performs three functions1) Subtract the residual ambient component in the measurement of approximation and crosstalk.2) Amplify the signal of the first stage of the integrator.3) Accumulate the signal from multiple pulses and hold the signal during ADC conversion.The block or multiplexer 24 bypasses the second stage of the proximity meter during the ambient measurement phase and connects the output of the integrator of the first stage to the ADC for digitalization.The integrator circuit 14 comprises an operational amplifier 36 and a capacitor arrangement 40 comprising a plurality, in the present embodiment six, capacitors which can be selected to be connected in parallel with the operational amplifier 36.The proximity sensor 2 also includes a light emitter driver circuit (not shown) that drives the light emitter 6 with alternating current 44. The light beams emitted from the light emitter 6 are reflected by an object in the vicinity of the light emitter 6 and received by the light detector 10, which indicates that the object is in the vicinity of the proximity sensor 2. When turned on, the light emitter 16 emits AC pulses that are detected by the light detector along with a large DC portion of the ambient light.The proximity sensor 2 comprises a circuit 16 for measuring the ambient light, which in the preferred embodiment shown is identical to the integrator circuit 14. The integrator circuit 14 includes a plurality of global clock (GCLK) pins. The GCLK pins control the switches in the switched-cap circuitThe analog-to-digital converter or ADC 28 generates a digital output signal 46, which output is connected to a digital core 50. The digital core 50 processes the raw data of the ADC and outputs normalized approximation data, as described further below. This signal can be used by a control unit / microcontroller of a device, in particular a mobile device such as a smartphone, for the on / off control or dimming of the display, while the user or another object is located in the vicinity of the display / proximity sensor.FIG. 2 is a flow chart of the proximity measurement. The digital core controls the FSM. All of the "input, output and action" activities described below are performed in the digital kernel 50.In FIG. 2, the operation of the proximity sensor 2 shown in FIG. 1 is shown in a flow chart starting with an arrow 70. The first block is an idle block 74 followed by a crosstalk calibration block 78. This block is invoked when the application initiates a calibration cycle when it determines that no target object is detected near the proximity sensor, i.e., that no target object is detected.If there is no target in the vicinity of the proximity sensor, the light emitter 6 is driven and the light reaching the light detector 10 is measured, as indicated in block 80. The ambient light is subtracted in block 20 in FIG. 1. Alternatively, the subtraction can also take place in the digital core. The measured crosstalk light intensity is used for calibration and stored in the digital core 50 (CT PDATA). After completion of the cross talk calibration, the method returns to idle block 74. The crosstalk calibration is preferably triggered by the system software by a command which is sent in particular by a microcontroller of the device, e.g. a smartphone.The crosstalk proximity data (CT PDATA) is therefore calculated under the condition "No Target" (NT) with the screen switched off and stored for subsequent distance cycles. The CT PDATA are preferably stored in special registers.Idle block 74 leads to a measurement block 82 where two measurements are made, namely the ambient light measurement (block 86) discussed in connection with FIG. 3 and the distance measurement (block 94).In an environment measurement block 86, the environment brightness or intensity is measured. The ambient light measurement is made at the beginning of each cycle of the approximation measurement, represented by block 94. Thus, the ambient light measurement and the distance measurement are always performed together and sequentially, as indicated by enclosing block 82. Based on the measured ambient light, an optimal approximation configuration is selected from preconfigured registers, as illustrated in block 90. This configuration includes measurement settings particularly for the light transmitter 6, the light detector 10, and the integrator circuit 14.As indicated in a further block 92, light zone detection is performed based on the determined ambient light level. Based on the light zone classification (see below for an example), the configuration of the light transmitter 6 and the light detector 10 and the integrator circuit 14 is selected, i.e., based on the ambient light level, appropriate transmitter and receiver settings are selected for the current approach cycle. The logic unit 32 selects, in dependence on the light level zone, a capacitor of the capacitor arrangement 40 which is connected in parallel with the operational amplifier 36.A preferred classification of the light zones is shown in the following table. The left column indicates various lighting intensity designations, while the corresponding lux numbers are found in the right column. The term "AL" means ambient light.HAL (High AL)72K to 110KBAL (Bright AL)36K to 72KMAL (Moderate AL)18K to 36KLAL (Low AL)9K to 18KDAL (Dark AL)10 up to 9KDepending on the interval in the right column in which the value of the measured light intensity is incorrect, the light intensity zone in the left column is selected. Each light level range corresponds to a selection of parameters of the light transmitter 6, the light detector 10, and the integrator circuit 14.The proximity measurement is then carried out in an approach measurement block 94. For this purpose, light emitter 6, which is designed as a vertical cavity surface emitting laser (VCSEL) in the present preferred embodiment, is driven, and light emitter 6 emits light pulses, which are detected by light detector 10 and integrated into integrator circuit 14.This integrated signal is then digitized in ADC 28 and the ADC output is recorded in digital core 50. The resulting output is raw approximation data (Raw PDATA). This is represented by a block 98. The described actions are performed based on user settings represented by a user setting block 120. The proximity measurement phase is thus performed with the selected measurement settings and the user-configured settings. Examples of user settings are VCSEL drive current, integration time, VCSEL drive pulse length, number of averaging cycles, etc.Starting from block 94, the method continues in a block 102 with distance data. In this block, as indicated in block 106, the approximation data is accumulated and averaged, and the crosstalk compensation is performed in the digital domain. For crosstalk compensation, the crosstalk calibration data from block 80 is used.The actions of blocks 98 and 106 are performed with respect to 12 configuration registers, as indicated by element 126. The result of these operations is the final approximation data, i.e., the averaged approximation data. Finally, the final proximity data (PDATA) is transferred and status flags are set for the reading of registers at the end of the cycle.These status indicators include, for example, "new data ready", "data negative", "data zero", "data above or below a certain threshold", "data saturation (analog and / or digital saturation)", "ambient light saturation", etc.The method is ended in an end block 110. As indicated in block 116, an interrupt is carried out in this end block 110 if it is activated or an interrupt is generated. The output of block 110, if enabled, is an interrupt, the final proximity data, and status flags. The interrupt behavior is determined by the application software. Ideally, a status bit is set and an interrupt is generated if the proximity data is above a threshold (high data). The application software responds to the interrupt by turning off the display (since the target (ear) is near the sensor). Similarly, if the distance is below a different threshold (low data), then another status bit is set and an interrupt is generated. The application software responds to the interrupt by turning on the display (since the target (ear) is far from the sensor).Referring now to FIG. 3, a method for measuring ambient light implemented in the proximity sensor and represented by block 86 in FIG. 2 in accordance with the preferred embodiment is shown in flow chart form.In a first block 150, an initialization is carried out. Initialization includes steps such as enabling the reference voltages, preparing the receiver circuit for integration, i.e., resetting the capacitors in the switching capsule circuits.In a subsequent decision 156, a decision is made as to whether an ambient light measurement or an approximation measurement is to be carried out. This occurs automatically in the device and in an order controlled by the digital core. The first ambient light measurement is performed, followed by the distance measurement.If an ambient light measurement is to be performed, the method continues in a block 162 in which the proximity sensor 2 is configured for an ambient light measurement, which essentially includes the configuration of the light transmitter 6, the light detector 10 and the integrator 14. After configuration / setting, the ambient light measurement is performed. The measured ambient light signal is digitized in a block 166, thereby producing a digital signal representing the intensity of the ambient light.In a decision 170, it is then decided whether a predefined number of ambient light pulses has been measured, which enable averaging of the measured ambient light intensity.If there are not enough pulses used, the method branches back to block 162 and the ambient light measurement continues. The term "pulse" here essentially denotes the length of the integration time. The emitter is not activated in this mode. The averaging serves to reduce the noise. Since the zone decision and the correct settings for the proximity measurement are determined by the ambient light measurement, averaging is performed to reduce the noise.If, on the other hand, all pulses have been delivered, the method branches from decision 170 to decision 176, which returns to block 150 when the proximity initialization has been performed, and otherwise to block 180.It is possible to repeat the initialization process (step 150) after the ambient light measurement phase. This is a user-selectable configuration. If the user wishes to repeat the initialization (for performance reasons), he can activate it by software. This takes additional time (overhead). If the effects of re-initialization on noise are minimal, the user may not do so.List of Reference Numbers2 Proximity sensor 6 Light transmitter 10 Light detector 14 Integrator circuit 16 Circuit for measuring the ambient light 18 Crosstalk measurement circuit 20 Unit 24 Multiplexer 28 ADC 32 Logic unit 36 Operational amplifier 40 Capacitor arrangement 44 AC pulses 46 Output signal 50 Digital core 70 Arrow 74 Idle block 78 Crosstalk calibration block 80 Block 82 Measurement block 86 Block for ambient measurements 90 Block 92 Block 94 Block for proximity measurements 98 Block 102 Block for processing proximity data 106 Block 110 End block 116 Block 120 Block with user settings 126 Element 150 Block 156 Decision 162 Block 166 Block 170 Decision 176 Decision 180 BlockReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedU.S. Pat. No. 9,608,132 B2

[0005] US 2014 / 0252212 A1

[0006] U.S. Pat. No. 8,692,200 B2

[0007] EP 3 425 802 A1

[0008]

Claims

An optical proximity sensor (2) comprising • an infrared light emitter (6) configured to emit pulses of alternating current of infrared light, wherein the infrared light emitter (6) is further configured to emit no or only a small amount of infrared light between the alternating current pulses; • a light detector (10) configured to detect DC signals of ambient light and AC pulses of infrared light emitted from the light transmitter (6) and reflected from an object to be detected toward the light detector (10), and • an integrator circuit (14) performing an approximation measurement using the light transmitter (6) and the light detector (10), characterized in thatthe integrator circuit (14) comprises an ambient light measurement circuit (16) configured to perform an ambient light measurement before performing an approximation measurement and to configure measurement settings of the light transmitter (6) and / or the light detector (10) and / or the integrator circuit (14) based on the ambient light measurement, and wherein the integrator circuit (14) is configured to perform the approximation measurement based on the measurement settings.The optical proximity sensor (2) of claim 1, wherein the integrator circuit (14) is configured to perform proximity measurements in cycles, and wherein the ambient light measurement circuit (2) is configured to perform ambient light measurement at the beginning of each cycle.The optical proximity sensor (2) of claim 1 or 2, wherein the measurement settings are configured based on the measured ambient light intensity.The optical proximity sensor (2) of claim 3, wherein a plurality of ambient light intensity ranges are defined, and wherein for each intensity range, associated measurement settings are defined in the integrator circuit (14), and wherein the integrator circuit (14) is configured to select the associated measurement settings based on the intensity range comprising the measured ambient light intensity.Optical proximity sensor (2) according to claim 3 or 4, wherein the power of the light transmitter (6) during the proximity measurement is adjusted as a function of the ambient light intensity as a measurement setting.Optical proximity sensor (2) according to one of claims 3 to 5, wherein as at least one measurement setting at least one parameter of the light detector (10) is set depending on the ambient light intensity.Optical proximity sensor (2) according to one of Claims 3 to 6, wherein the amplification factor of the integrator circuit (14) is set as a measurement setting as a function of the ambient light intensity.The optical proximity sensor (2) of claim 7, wherein the integrator circuit (14) comprises an operational amplifier (36) and a capacitor array (40) having a plurality of capacitors electrically arrangeable in parallel with the operational amplifier (36), and wherein the integrator circuit (14) is configured to select a parallel capacitor of the capacitor array depending on the measured ambient light intensity during the proximity measurement.Optical proximity sensor according to one of the preceding claims, wherein the circuit for measuring the ambient light (16) is identical to the integrator circuit (14).Optical proximity sensor (2) according to one of the preceding claims, having a circuit for measuring the crosstalk.The optical proximity sensor (2) of claim 10, comprising an ADC (28), wherein the outputs of the measured ambient light and crosstalk measurements are converted into digital signals in the ADC, and wherein a digital core (50) is configured to perform ambient light and crosstalk corrections of the digitized proximity measurement signal.The optical proximity sensor (2) of claim 10, wherein crosstalk calibration coefficients applied in the crosstalk correction based on the measured crosstalk signal are stored in a digital core (50).The optical proximity sensor (2) of any preceding claim, configured to provide normalized proximity data as an output.Optical proximity sensor () according to one of the preceding claims, wherein the light detector (10) is designed as a photodiode.Method for detecting the proximity of an object, comprising the following steps: • in an integrator circuit (14), carrying out an approximation measurement by emitting AC infrared radiation by an infrared transmitter (6) and measuring the reflected radiation by a light detector (10); • carrying out an ambient light measurement; characterized in that the ambient light measurement is carried out before the approximation measurement, and in that the infrared transmitter (6) and / or the light detector (10) and / or the integrator circuit (14) are configured for the approximation measurement on the basis of the ambient light measurement.

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