Time of Flight Image Sensor

Overview

Time of Flight (ToF) image sensors measure the distance to a target object by emitting light from a source, usually a laser or LED, and detecting the reflected light, based on the time elapsed between the two. In addition to capturing images in the X and Y directions, they can acquire information in the Z direction and are capable of sensing in a 3D space. This enables inspections based on volume and 3D shapes, as well as the ability to distinguish overlapping objects - capabilities which are difficult to achieve with conventional 2D imaging. The sensors can also be used for applications in which relative distances are used in real time, such as automatic control and collision avoidance.

ToF image sensors, which are compact, high-accuracy, and capable of instantly acquiring 3D information, meet rising demands such as object recognition and measurement, as well as automation. They can be used in a wide range of areas and applications in industrial equipment fields.

Features

dToF sensors capable of measurement over long distances and iToF sensors offering high speed and high image resolution

There are broadly two types of ToF sensors.

Direct ToF (dToF)

This type of sensor measures the time between the emission of light and detection of the reflected light. It uses single photon avalanche diode (SPAD) pixels, detecting even low levels of light. This allows for accurate measurement of distant objects.

Indirect ToF (iToF)

This type of sensor measures distances by accumulating the electric charge generated by the reflected light in each pixel and detecting any phase differences from the time of emission of light. It uses a conventional CMOS image sensor structure and can capture high-resolution 3D images even with a compact size.

Areas of application for these different ToF sensors

Product Lineup

SPAD ToF Depth Sensor IMX560
Compact, high-accuracy SPAD ToF depth sensor capable of measurement over long distances
iToF Image Sensor IMX556/IMX570
High-speed, high-resolution iToF image sensor that excels at near- to mid-range sensing

ToF type	Model name	Number of effective pixels	Image size	Unit cell size	Frame rate (Max.)	Recommended light source wavelength	Modulation frequency	Output interface
SPAD ToF	IMX560	597 (H) × 168 (V) approx. 100K SPAD pixels	Type 1/2.9 (Diagonal 6.25 mm)	10.08 µm×10.08 µm	100 frame/s (*)	850 nm, 905 nm, 940 nm etc.	1 GHz	MIPI CSI-2
iToF	IMX556	642 (H) × 484 (V) approx. 300K pixels	Type 1/2 (Diagonal 8.0 mm)	10 µm×10 µm	60 frame/s (VGA resolution)	850 nm or 940 nm	4 ~ 100 MHz	MIPI CSI-2
iToF	IMX570	648 (H) × 488 (V) approx. 300K pixels	Type 1/4.5 (Diagonal 4.0 mm)	5 µm×5 µm	56 frame/s (VGA resolution)	850 nm or 940 nm	2 ~ 120 MHz	MIPI CSI-2