Measuring the time it takes for a light wave to travel from an object and back is the basic principle of time-of-flight ToF sensors. Recently, a new crop of ToF sensors has emerged targeting a slew of interesting applications.To get more news about accessories for doors and windows, you can visit securamsys.com official website.
In this article, we round up a selection of ToF sensors that leverage a variety of technologies to enable human presence detection, facial recognition, and other ToF sensor capabilities.For its part, last month STMicroelectronics (ST) unveiled the latest ToF sensor of its FlightSense product line, the VL53L5CP. The device is aimed at enabling gesture recognition, intruder alert, and human presence detection in PCs. According to ST, the new ToF sensor improves interactions, enhances security, and delivers power-saving attributes to PC cameras. The company’s FlightSense portfolio has come a long way since ST’s first 64-bit multi-zone ToF sensor was announced in late 2020.
The VL53L5CP starts by scanning a 61-degree field of view to map out the scene, gathering intelligence without using a camera or prerecorded images. Using ToF technology, the sensor can detect and log multiple targets, measure X/Y/Z coordinates, and track several targets within 64 zones.
The new sensor is provided with ST’s third-generation Presence Premium PLUS software. The software has dedicated algorithms that enable PC designers to create custom AI applications. This combo lets them implement smart power management, security, and touchless user interaction features, says ST.
At the hardware level, the VL53L5CP has an embedded single-photon avalanche diode (SPAD) array, physical infrared filters, and diffractive optical elements (DOEs). Each component can assist PC cameras to reflect/deflect light to obtain interactions or gestures in various ambient light levels.
Those technologies make the VL53L5CP well suited for human presence detection in PCs. ST reports that PC manufacturer Lenovo is integrating the VL53L5CP into a select number of its laptops. More information is available in the VL53L5CP data brief. Going for a modular approach, at the Sensors Converge 2022 show in June, Analog Devices debuted its ADTF3175 ToF sensor module. The company claims it as the industry’s first high-resolution, industrial quality, indirect ToF (iToF) module for 3D depth sensing and vision systems. The device is designed to enable cameras and sensors to perceive 3D space in resolutions of 1 megapixel. It offers a depth accuracy of ± 3 mm across its full depth range of 0.4 to 4 meters.
At the heart of the ADTF3175 module is the company’s ADSD3100 chip, a 1-megapixel CMOS iToF imager. The module also integrates the lens and optical bandpass filter for the imager, an infrared illumination source. The source consists of optics, laser diode, laser diode driver and photodetector, a flash memory, and power regulators for producing local supply voltages.
Analog Devices says that the module comes fully calibrated at multiple range and resolution modes. Completing the depth sensing system, the raw image data from the ADTF3175 is processed externally by the host system processor or depth ISP.
Interfacing the ADTF3175’s image data output to the host system is done via a 4-lane MIPI (mobile industry processor interface) CSI-2 (Camera Serial Interface 2) Tx interface. Programming and operation are accomplished through 4-wire SPI and I2C serial interfaces. The ADTF3175 module’s size is 42 mm × 31 mm × 15.1 mm and is rated for an operating temperature range of -20°C to 65°C. More information can be found in the ADTF3175 datasheet.
