Design of irregular microlens array for the switchable adaptive headlight high beam

Today the “slit-like” shape of the car’s headlamp with very small vertical size is getting more and more attractive to the customer than the traditional form-factor. Inevitably, it causes significant drop in light transmission, which may be a critical disadvantage for the future electric cars, where electrical efficiency of each unit is crucial. Beam shaping with microlens arrays is an effective solution for system miniaturization, whilst keeping its high transmission. Multichannel structure ensures more design flexibility, while intentional irregularities of the lenslets’ shape provide a possibility of achieving desired arbitrary symmetric or asymmetric light beam profile without absorbing masks, hence saving a lot of system transmission in a still compact size. As an example, we present a maskless design for a segmented high beam with a feature of dynamic switching of its vertical segments for the adaptation during driving, using a concept of controlled intentional “cross-talk” in between the array channels. The microlens arrays are mastered by grayscale lithography. Subsequently the masters are replicated as double-side aligned polymer-on-glass elements by UV reaction molding.