Mitsubishi Electric Corporation developed a compact and highly luminous optical module for LED headlights, using a system that combines a converging lens and projecting lens for more efficient LED headlights. Even though the new system measures only 20 millimeters high, it achieves 180% luminous efficiency, which is equivalent to larger 40-millimeters to 60-millimeters projecting lenses. Optimal light-distribution control and design flexibility enhance driving safety and ease while lowering energy consumption, making the module a suitable solution for next-generation smart mobility. The new technology will be exhibited at the Mitsubishi Electric booth during CES Asia 2018 in Shanghai, China from 13–15 June.
Headlight optical systems collect light projected from an LED light source to form a light beam with a cutoff line for the low beam. Conventional systems use reflectors with coated mirrors that are prone to reflection loss, low efficiency and take up space due to their large size. Mitsubishi Electric, aiming to enhance night-driving safety by achieving superior visibility for the driver and the elimination of glare for other vehicles and pedestrians, has developed an optical module for LED headlights that is compact, highly luminous-efficient, equipped with advanced and precise beam-control functions and offers design flexibility.
1. Direct projection for compactness and high luminous efficiency
- Unique optical system for LED light source convergence and projection.
- Compact, 20-mm-high design incorporates no mirror.
- 180% luminous efficacy equivalent to that of larger 40-mm–60-mm projectors.
- Compactness and high luminous efficacy achieve design flexibility, resulting in diverse thin-, multiple- and single-light options for motorcycles and automobiles.
The optical system incorporates only two key components: a converging lens and a projection lens. The converging lens, which suppresses diffusion and forms a beam shape with no reflection loss, sends LED light to the projection lens, where the light strikes a reflective non-vacuum metalizing surface. The light is projected forward in parallel, resulting in high luminous efficiency.
2. Effective beam control for enhanced ease of driving and safety
- Sensor detects pedestrians and illuminates them with a spot beam to compensate for low-beam lights.
- Color temperature (quantitative measure of colors ranging from bluish white to yellowish white to red) can be adjusted for the driver's nighttime color visibility.
- Adaptive driving beam (ADB) by precise beam-control functions.
Obstacles that are not illuminated by low-beam headlights pose a challenge, so Mitsubishi Electric developed a function that projects a spot beam on obstacles detected by a sensor, enabling early identification of pedestrians, etc., for safer nighttime driving.
Furthermore, a human-system interface allows the light's color temperature to be adjusted according to the driver's needs, thereby improving night visibility for each driver. In addition, the LED lighting control includes an ADB for passive high-beam driving to secure superior visibility.