From drying to intelligent care, the focus of competition in the high-end hair dryer industry is quietly changing. The competition in product experience is no longer limited to motor speed or heating power, but increasingly extends to the machine's ability to perceive usage status. Behind this trend, the proximity sensor has become an important variable affecting the experience differences of flagship models. The M8001 dToF sensor launched by the Sensor Division of Xichan Microchip is tailor-made for intelligent care scenarios. The following disassembles the sensing solution of high-end hair dryer sensors from three dimensions: accuracy, frame rate and anti-interference.

I.Accuracy Determines the Safety Bottom Line

When a user blows hair close to the scalp, if the sensor falsely reports 10 cm as 12 cm, the main controller will maintain high-power output thinking the hair is still far away, and the risk of scalding will follow; conversely, if the distance is falsely judged to be too far when blowing hair from a distance, the main controller will reduce the power excessively, and the drying efficiency will drop off a cliff.

M8001achieves high-precision and stable distance measurement. This stability stems from the physical advantages of the dToF architecture: it directly measures the photon flight time through a Single-Photon Avalanche Diode (SPAD) to calculate the distance, and with the on-chip histogram algorithm, it caneffectively distinguish the real echo of hair from the stray reflections generated by the inner wall of the air duct and the structural cover plate, providing a solid data foundation for the main control algorithm.

II.Frame Rate Determines the Response Upper Limit

The moving speed of the hand during hair blowing can reach tens of centimeters per second. If the sensor frame rate is lower than 50Hz, the outputdistance data will always lag behind the actual movement, and the userwill feel that the air temperature is slow, or even fluctuates between cold and hot.

Frame rate determines the number of distance values output by the sensor per second.M8001 supports aframe rateof up to200Hz, allowing the main controller tofollow hand movementsin near real-time. For flagship models, the frame rate range of 100-200Hzis an importantwatershedfrom basic usability to comfortable and imperceptible experience.

III. Anti-interferenceDetermines Mass Production Yield

The bathroom is one of the unfriendlyenvironmentsfor optical sensors, with at least four challenges: water vapor, stray light, specular reflection and chemical erosion. M8001 has built multiple protections specifically from the beginning of design to ensure stable operation in real scenarios.

1.Reflectivity Difference Compensation

The built-in algorithm automaticallyadapts tothe differences between black hair's light absorption, light hair's reflectionanddry and wet hairconditions, andalwaysoutputs consistent distance measurement results.

2.Infrared Interference Filtering

Integrated with a dedicated infrared filter, it effectively shields ambient stray light such as vanity lightsand bathroom heaters, ensuringsignal purity.

3.Multiple Reflection Suppression

Forfalseechoes caused by multiple reflections that may be generated by structural components such as thetransparentcover of the air duct, theon-chip histogram algorithmaccuratelydistinguishes between true and falsefrom the time dimensionand eliminates interference signals.

4.Optical Window Erosion Compensation

The dynamic stain compensation functioncanautomatically offset thelong-termsignal attenuation caused by high-temperature steam and dust accumulation, maintaining measurement stability throughout the entire life cycle.

IV.System-level Advantages: Architecture Subtraction and Supply Chain Addition

Most mainstream ToF solutions adopt external Flash for firmware storage and rely on an external MCU to download programs upon power-up. This leads to extra material costs, startup latency and EMC risks.

V.Returning to Perception: The Starting Point of Intelligent Experience