The ToF sensor capable of taking a range image (source: Panasonic)

Panasonic Corp developed a range image sensor that can take an image of a 10cm object located 250m away in the dark.

For ranging, the sensor uses ToF (time of flight), which emits infrared light and calculates a distance based on the time that it takes the reflected light to return. To increase the accuracy of measuring a remote place that makes the reflected light weak, Panasonic used a high-sensitivity light-receiving device.

The sensor has about 260,000 (688 x 384) pixels so that recognition with image analysis becomes easier.

It improves the resolution of a range image at night. A range image taken by using a prototyped ToF sensor. It can take an image of a 10cm or smaller object located more than 200m away at night. It enables to detect curbs and balls with a diameter of 10cm or less. (source: Panasonic)

Panasonic expects that the sensor will be used for monitoring the surrounding situation of a vehicle as well as for monitoring cameras.

In the field of autonomous driving, the company considers that the sensor can supplement the functions of existing sensors because the new sensor (1) supports a longer distance than LiDAR (light detection and ranging), which enables to obtain range images, and (2) can take images in the complete dark unlike CMOS image sensors.

Panasonic expects to start to ship samples in fiscal 2019 and begin volume production in fiscal 2021.

Measurement carried out several times for each distance range

For taking range images, the new sensor uses a principle similar to the principle of flash-type LiDAR. In other words, near-infrared-light pulse (wavelength: 940nm, output: 1,200W, pulse width: 10ns, GaAs-based laser device in the case of the prototype) is applied to the entire imaging area. Reflected light is received by an array of light-receiving elements, and the ToF of each pixel is measured.

Go to next page