To further improve vehicle safety, driver monitoring systems are increasingly being installed in vehicles equipped with advanced driver assistance systems (ADAS) to detect factors such as drowsiness, sleepiness, and distractions while driving. In Japan, the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) has established guidelines defining the system's design and functions, and in the EU, mandatory installation is planned for all new vehicles sold in Europe starting in July 2024. Automakers and suppliers are also developing onboard monitoring systems to detect occupants in addition to the driver, and there is a growing awareness within the industry of the need for high-performance light sources that enable detection systems to operate more accurately.
In response, ROHM has developed VCSELED™ technology, which achieves high-precision detection. The minimal temperature variation across the wavelength, combined with a wide beam angle, makes this technology ideal not only for onboard monitoring systems but also for improving the accuracy and performance of inspection systems for robots and industrial equipment, as well as spatial recognition and distance measurement systems.
VCSELED™ widens the beam angle (irradiation angle) similarly to LEDs by combining a high-performance VCSEL element and a light-diffusing material to enable detection over a wider area with greater accuracy than VCSELs. Furthermore, the light-emitting element and light diffuser are integrated into a compact package, contributing to smaller and thinner applications.
The VCSEL element used in VCSELED™ features a narrow emission wavelength bandwidth of 4 nm, which is approximately one-seventh that of LEDs. This characteristic improves resolution performance on the receive side while eliminating the red glow typically associated with LEDs. Simultaneously, a wavelength temperature variation of 0.072 nm/°C—less than one-quarter that of LEDs (0.3 nm/°C)—enables high-precision detection unaffected by temperature changes. Furthermore, the light emission response time is 2 ns, approximately 7.5 times faster than LEDs, contributing to improved performance in Time-of-Flight (ToF) applications that use infrared light to measure distances.
ROHM is working on the commercialization of VCSELED™ as a new technology brand for infrared light source components. Prototype samples are now available, and mass production samples for consumer applications are scheduled to be released in October 2024, and for automotive use in 2025. For more information, please contact a sales representative or visit the contact page on the ROHM website. We will continue to develop laser light source technology for on-board monitoring and other systems in the future.
*VCSELED™ is a trademark or registered trademark of ROHM Co., Ltd.
