Time of Flight Image Sensors - ToF

The Time of Flight (ToF) technology is a type of 3D imaging that measures the time it takes for light to travel between an object and a camera.

Time of Flight (ToF) Introduction  

The ability to measure objects at a distance to determine how far away they are and/or their overall dimensions is becoming more popular in Imaging. With this, there are several different techniques and technologies, each with their own advantages and disadvantages. Picking the right one can be daunting without someone in your corner to help decipher your needs and direct you to the best product to meet them. 

A popular technology that is gaining recognition is Time of Flight (ToF) for its simplicity and ease of use. These products are based on measuring the time it takes light to travel to and from a reflective surface. It works by having a camera send out a light pulse or stream of pulses and measuring the time delay for it to be detected back at its sensor’s pixels. With this time measured, an accurate distance can then calculated and a depth map created.  

ToF Types

There are two distinct approaches used in Time-of-Flight systems, each with their specific advantages within a given application. Direct ToF (dToF) uses a short light pulse, about a few nanoseconds in length, the delay between the emission and the reflection from the target is measured and the distance to the target can then be determined. 

For Indirect Time-of-Flight (iToF), the principle is similar to dToF with the exception of pulses of light are sent as a stream, where the emitted light is modulated. The receiving sensor repeatedly measures reflected light identifying the phase difference between the outgoing and reflected signal. This phase angle can then be used to determine the distance of the target through a simple calculation. 

Time of flight sensors are commonly used in a wide range of applications, including industrial, scientific, and medical imaging systems. These sensors are able to provide high-resolution distance measurements that can be used for depth mapping or object detection purposes. In addition, time of flight sensors can also be used for 3D imaging, where multiple images taken from different angles are combined to create 3D visualizations. A key benefit of using time of flight sensors for these applications is their ability to provide high-resolution distance measurements with relatively low power usage, making them ideal for use in portable or battery-powered devices.

Create Accurate Depth Maps with ToF sensor

In addition to imaging in X and Y directions, 3D image sensors also acquire the Z-direction (e.g. depth) information, enabling 3D sensing. Time of flight sensor detect distance information of each pixel, creating highly accurate depth map. 

Depth Maps Conventional



3D sensing opens up the possibility of discerning things that are difficult with conventional 2D images, as in inspection based on volume or shape, or discerning overlapped objects.
Depth Maps Conventional 3D ToF camera

3D sensing opens up the possibility of discerning things that are difficult with conventional 2D images, as in inspection based on volume or shape, or discerning overlapped objects. 

Sony’s iToF Products – a Great Progress in 3D Vision

Sony has introduced a line of iToF products such as IMX556 and the new IMX570 sensor that are especially effective in high-speed, high-resolution 3D imaging of objects at short and long distances. 

itof image sensors

Key Features of Sony’s New IMX570 Sensor
The new IMX570 is a 1/4.5-type VGA sensor with 5 µm pixels that reaches a frame rate up to 56 fps. 

Key Features of Sony’s IMX556 Sensor
The IMX556 is a type 1/2-type VGA sensor with 10 µm pixels that reaches a frame rate up to 60 fps.

Explore the Advantages of ToF Technology in a Variety of Applications

time of flight sensor

ToF in Logistics

ToF sensors are ideal for optimizing material handling lines by measuring positions, sizes and loading rate of pallets or cargos, and for autonomous mobile systems such as AGVs and last-mile robots.

Factory Automation

ToF image sensors can be used in automation, for detection of intrusion into hazardous area, operation monitoring and object location detection for robot picking.

time of flight sensors

Commercial & Public Facilities

ToF camera can be used for easy and accurate measurement of crowd levels at stores, airports, theme parks and other public locations as well as sophisticated access control.

ToF Sensors in Farming & Agriculture

Quality control and productivity improvements, e. g. automated milking, body condition scoring, feed amount detection along with other shape related applications like automatic fruit picking.

Civil Engineering & Construction

Detection of environmental features or objects and support for driver assistance, vehicle automation, site visualization/documentation.

Time of Flight sensors in other areas

There are many different applications for time of flight sensor, including robotic navigation, obstacle detection, and depth mapping. They can also be used for scanning objects or creating 3D models of objects, making them useful in fields like engineering, manufacturing, and design. Additionally, time of flight sensors are becoming more popular in driverless cars, where they can be used to detect obstacles and help the vehicle make safe driving decisions.

Sony’s IMX570 Features State-of-the-Art iToF Technology

Sony has released a back-illuminated, time of flight 3D image sensor for industrial machineries. The new IMX 570 is a type 1/4.5 VGA sensor with 5 µm pixels.  

Applying Sony’s sensing and ranging technologies, the compact and high-resolution sensor acquires depth data which can cover both short and long distances.  

Key Features of Sony’s New IMX570 Sensor:

FSM-IMX570 Developer Kit

FRAMOS has launched a new, end-to-end 3D vision developer kit to help engineers quickly prototype systems for 3D machine vision, using Sony’s IMX570 Indirect Time-of-Flight (iToF) 3D vision sensor.

This package includes everything needed to operate the sensor, and get a 3D Depth Map working with your application. In addition, camera developers can receive raw image data, and implement the depth processing by themselves, while comparing it at any time with a calibrated reference implementation on the same hardware.

The package provides open-source drivers as blueprint, providing base functionality, flexibility and transparency within the NVIDIA Jetson Family – one of the most powerful embedded processing platforms currently available.

Image: FRAMOS ToF Developer Kit (NVIDIA Jetson embedded computer not included)

What’s in the Kit

The FRAMOS FSM-IMX570 Developer Kit is a single, calibrated assembly that includes the following components:

FRAMOS Sensor Module

The Sensor module includes the Sony IMX570PLR-C Indirect Time-of-Flight (iToF) sensor, which produces a 640×480 image at 30 fps, and is equipped with an M12 lens which has been optimized and factory-aligned for the sensor.

Active Illumination 

The illumination component is equipped with 4 VCSEL Laser Diodes utilizing specialized Sony Drivers, inputs for an external power supply, and an FFC connector for synchronization with the FRAMOS Sensor Module.

Onboard Depth Processing

The kit utilizes the standard Ecosystem approach, incorporating a FRAMOS Sensor Adapter board and adding a Sony Depth Processor to the sensor periphery; providing the versatility of the FRAMOS PixelMate™ MIPI CSI-2 interface.

Processor Board Adapters

Via its PixelMate™ interface, the front-end provides full compliance with the Processor Adapter Boards of the FSM Ecosystem. 
Each Developer Kit includes a FRAMOS Processor Board Adapter, that provides physical connectivity to a variety of embedded processing platforms (SOCs / SOMs), and the NVIDIA Jetson Family of products, including the AGX Orin, Xavier, Orin, Xavier NX, TX2 NX and Nano. 

Get up and Running Fast 

FRAMOS’s FSM-IMX570 Developer Kit is the first product of its kind to provide easy functionality and full component level control for the next gen of Sony DepthSense™ sensors within the NVIDIA Jetson family of SOMs for Embedded solutions, and includes everything needed to get a Sony IMX570 iToF sensor up and running and an image on your screen in less than an hour.

This new offering leverages FRAMOS’s long-standing partnerships with Sony and NVIDIA to create a path forward for companies seeking to develop their own 3D vision solution for robotics, logistics, and other applications.

Available products

Sony IMX570PLR-C
Sony CMOS TOF, 0.32 MP, 648 x 488, 1/4.5 inch, 5 x 5 µm, 56 fps, MIPI,
Sony IMX556PLR-C
Sony CMOS TOF, 0.31 MP, 642 x 484, 1/2 inch, 10 x 10 µm, 60 fps, MIPI, Back-illuminated Time of Flight (ToF),


Time of flight sensors are used to measure the time it takes for a pulse of laser light to leave the sensor, reflect off an object and return to the sensor. This information can be used to calculate the distance between the object and the sensor.

A ToF sensor works by sending a pulse of laser light from the sensor to an object and measuring the time it takes for the light to return. The distance between the sensor and the object can then be calculated based on this information, using various equations or algorithms. Some time of flight sensors also use other techniques, such as stereo vision, to help further improve their accuracy and precision.

There are many benefits of using a time of flight sensor, including its high accuracy and precision, ability to work in a wide range of environments, and versatility in terms of applications. These sensors are also often smaller and cheaper than other types of distance measurement sensors, making them an attractive option for a wide range of industries and applications.

When choosing a ToF sensor for your application, there are several factors to consider. These might include the maximum range and accuracy required, the operating environment and conditions, and the type of object or objects that need to be measured. Other considerations may include cost, size, and other performance metrics such as response speed and robustness.

Some common applications for ToF sensors include autonomous vehicle navigation, obstacle detection and avoidance, 3D scanning and mapping, object tracking and identification, robotic guidance and control, and gesture recognition. These sensors are also used in a wide range of other industries and applications, including healthcare, manufacturing, security systems, logistics and supply chain management, energy, and aerospace.

A 3D time of flight camera, or 3D ToF camera, is a type of depth measurement sensor that uses the time of flight principle to calculate the distance to an object or scene. This information can be used for various applications, such as autonomous vehicle navigation, object tracking and identification, 3D scanning and mapping, robotic guidance and control, and gesture recognition. Compared to other depth sensing technologies such as stereo vision and structured light, time of flight sensors are usually smaller, cheaper, and offer higher accuracy and precision.