A room at the Volkswagen research and design facility in Belmont, Calif., which uses a Redwood Systems DC LED lighting control system.

LED lighting control developer Redwood Systems announced Thursday that Japanese conglomerate Mitsui Group has invested $3.5 million.

Redwood Systems already had venture capital firms U.S. Venture Partners and Battery Ventures as investors.

However, an endorsement from a global company like Mitsui puts an especially big spotlight on the company, and on computerized lighting-control systems in general.

Redwood Systems makes computerized DC (direct current) lighting control systems aimed at improving energy efficiency.

Using sensors or motion detection cameras, the system is capable of gathering data on things like temperature and room occupancy. That data can then be used to adjust lighting under the system's control accordingly. The system can also be set on a schedule via a Web-based platform.

It uses servers to supply electricity to light fixtures via Ethernet cables using low-voltage DC instead of AC (alternating current), improving efficiency.

While Redwood Systems has installed systems for general office space, it has also done a lot of installations for company data centers. Clients include Facebook, Volkswagen, and SAP, according to Redwood.