Toppan and Brookman Technology’s next-generation time-of-flight sensor is the world’s first capable of measuring distances up to 30 meters

The new sensor is capable of measuring over a range more than five times greater than that possible with 3D sensors using the conventional indirect ToF method. This will help improve the operability and safety of autonomous drones and robot carriers equipped with sensors to enable them to avoid obstacles. The ToF hybrid sensor also has a unique ambient light suppression function, making it the first in the world[2] CMOS image sensor capable of measuring distances up to 20 meters in conditions with an illuminance of 100,000 lux, equivalent to midsummer daytime brightness.

Details of this new type of ToF sensor technology were presented June 15 by Toppan, Brookman Technology and Shizuoka University at the 2022 IEEE Symposium on VLSI Technology & Circuits (VLSI Symposium), an international conference on semiconductor technologies held in Honolulu, Hawaiifrom June 13-17 from the Institute of Electrical and Electronic Engineers.

The 3D sensor market is expected to expand as smartphones and game consoles become more sophisticated and the use of autonomous robots in the industry grows. There are different types of 3D sensors, based on the different principles used to detect distance. ToF sensors estimate the distance to an object by measuring the time it takes for the emitted light to be reflected. In the wake of advances in technological development in recent years, the use of ToF sensors for smartphones and other devices is on the rise due to their compact form factor and low power consumption.

Autonomous robots and drones must have an environmental mapping function that allows them to detect obstacles tens of meters in front and ascertain their position from video images. However, the widespread use of 3D sensors using the conventional indirect ToF method has been limited due to insufficient ambient light tolerance when used outdoors.

With Brookman Technology now on board as a subsidiary, Toppan has been able to leverage the strengths of both companies to lead the development of a new type of 3D sensor. This has led to the development of a hybrid ToF technology based on the refinement of Brookman Technology’s unique “short pulse modulation”.[3] method, which enables long-distance measurements, exceptional ambient light tolerance, high-speed imaging, and simultaneous use of multiple cameras.

“Together with Brookman technology, we hope these new sensors will contribute to increased safety and convenience by acting as ‘3D sensing eyes’ that expand the possibilities of autonomous robots and industrial devices,” he said. Tatsuo Noguchi, head of the ToF Business Development Center in Toppan. “Toppan will lead the further development of range sensor cameras employing the new ToF technology, with a plan to make the models available for testing starting in December this year and launch sales in the fall of 2023.”

Features of the new ToF sensor

Measure distances up to 30 meters

The use from a hybrid ToF method allows you to measure distances up to 30 meters, about five times higher than conventional models.

Noise canceling function to facilitate outdoor measurement in midsummer conditions

Each pixel has a function to eliminate external light components. This removes ambient light noise and makes accurate measurement possible even when the illuminance is in the range of 100,000 lux, equivalent to midsummer daylight.

High-speed imaging of 120 frames per second

Distances can be measured without blurring, which can cause errors, as the measurement and noise suppression of ambient light is done in a single frame. This allows you to capture a maximum of 120 images per second, approximately four times the capacity of existing models.

Simultaneous operation of up to 256 cameras

A unique control technique allows you to cancel signals from other cameras by treating them as ambient light. This means that up to 256 cameras can be used simultaneously without interference between cameras.

Learn about Brookman technology

Brookman Technology, Inc. was founded in Hamamatsu, Japan in 2006 as Brookman laboratory, Inc., by Dr. Shoji Kawahito, CMOS image sensor expert, professor of electrical engineering at Shizuoka University. Since then, Brookman Technology has worked on numerous forms of analog and mixed-signal CMOS IC design, specializing in the design of advanced CMOS image sensors for a wide range of applications. The company became a subsidiary of Toppan in March 2021 through the acquisition of 94.6% of its shares.

About Toppan

Established in Tokyo in 1900, Toppan is a leading and diversified global supplier committed to providing integrated and sustainable solutions in industries such as printing, communications, security, packaging, decorative materials, electronics and digital transformation. Toppan’s global team of more than 50,000 employees offers optimal solutions enabled by industry-leading skills and technologies to address the diverse challenges of each business sector and society and contribute to the achievement of shared sustainability goals.

For more information, visit https://www.toppan.com/en/ or follow Toppan on LinkedIn https://www.linkedin.com/company/toppan/.

1. The hybrid ToF method, proposed by Prof. Shoji Kawahito of Shizuoka University, is a new detection technology based on the indirect ToF method to measure distance by phase difference and combine it with the direct ToF methodology for measurement based on the time difference. As the round-trip time of the light is estimated by combining multiple short-lived windows using so-called “multiple window technology”, the tolerance of the hybrid method to ambient light noise, which can be problematic when surveying outdoors , is superior to that of the conventional indirect ToF method.

2. As a ToF sensor with a conventional CMOS image sensor pixel structure which does not use an avalanche photodiode. Toppan research based on prior art documents and existing product catalogs (June 2022).

3. In contrast to “continuous wave modulation”, where continuous waves of light are emitted, “short pulse modulation” is a method of measuring distance by emitting pulses of light of extremely short duration.

SOURCE Toppan

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