Miniature Lens Assembly for Light Projection

In automotive lighting today, the beam is generally shaped using optical technology which is several decades old. Usually, the physics of light projection necessitates a long minimum distance between the light source and the projector lens. This means that the entire projector module assembly has a large volume, and occupies a substantial area in the body of the vehicle. By projecting an image through an array of lenslets, the focal length between the light source and the lens can be massively reduced. This creates a projector with far smaller dimensions than a conventional single-lens projector.

The adoption of Micro Lens Array (MLA) technology marks an abrupt break from traditional approaches to automotive lighting design: the first time it enables a tightly-focused beam or even an image or pattern to be projected on the surface of the road or pavement, all this from an assembly, just a few millimeters deep and high.

Enhanced Decorative Lighting was the first application for Micro Lens Array technology. Today, there are many practical use cases and automotive designers are continually inventing new use cases. The technology is used to display a pattern or a logo in good resolution (e.g. foot well lighting picture, welcoming light, etc.). In future, safety lighting is of great interest for car manufacturers, for example, guidelines for reversing maneuvers.

Exterior Decorative Lighting

Pathway lighting, projected from under the door sills, can display a pattern distinctive to the model or brand when the vehicle detects the proximity of the key fob. This convenience and safety feature illuminates the road surface where the user will step to enter the car.

It can also imbue a sense of personality to the car – the lights ‘welcome’ the driver on his or her return to the car in the dark. A unique image projected on the ground can also become a signature of the vehicle’s brand.

Welcome Light Carpet

In this exterior decorative lighting application, a static or dynamic projection – for example, the vehicle’s brand mark – welcomes the driver as they approach their parked vehicle. The projected pattern remains sharply focused and homogeneous even on an uneven or slightly angled road surface, as the compact Micro Lens Array (MLA) is mounted in the side sills of the car door delivers superior performance. One MLA module on each side of the car is used for projection, using a new and improved collimator. Applications are realized using one of the open market platforms, with a similar FOI range (max FOI ±10°). Regulatory status is not a limiting factor for this application (parked vehicle use only).

As a renowned large-scale mass producer of Wafer Level Optics (WLO), ams is the right partner to share its technology innovation and expertise in the evolving field of semi-dynamic projection. This can be vertically integrated with our own optical MLA design and production capabilities.

Our product platform for the open market is scheduled for availability in the first half of 2021, with customer projects due to begin thereafter.

> Watch our demo video about projection lighting

Back-up Guide

In this exterior functional lighting application, red or white markings projected on the road surface while backing up combine both functional and safety (pre-warning) information to the driver. Mounting options include a single module with both Micro Lens Arrays (MLA) (L/R) positioned centered at the rear bumper or as two modules (one left and one right), possibly integrated in the rear lamps. The targeted illuminance can be adjusted to the projection distance and a sharp image is delivered despite projection under a shallow angle, due to the high depth of view of the optical system (the whole pattern is in hyper focal distance).

As a renowned large-scale mass producer of Wafer Level Optics (WLO), ams is the right partner to share its technology innovation and know-how in this new market segment. This can be vertically integrated with our own optical MLA design and production capabilities. This application shares many of the advantages of MLA technology, including sharpness of image on uneven/slightly angled surfaces.

Our product platform is scheduled for availability in the second half of 2021, with customer projects due to begin thereafter.

Composition of a Projected Lighting System

An MLA-based projected lighting assembly is composed of an LED light source, collimator and the micro-lens array itself. The array is a custom-designed module; a typical MLA measures 11.4mm x 10.7mm x 3.0mm.

The array is a precisely manufactured set of miniature lenses, or ‘lenslets’. As the lens array is fabricated through processes shared with the semiconductor industry, MLA technology benefits from the same cost and quality advantages that silicon chips enjoy.

Nanoscale fabrication also means that the lenslets can be precisely shaped and positioned so that they project a single, sharply-focused image on to a surface at a specified distance from the projector. The surface may be specified to be flat, curved or freeform, and perpendicular to the projector or tilted.          

> Check out our webinar about Projected Lighting