Driver assistance systems are becoming the norm in the automotive industry and their use will only continue to be more prevalent. One type of assistance system is the heads-up display (HUD), which uses a series of projectors, mirrors and beamsplitters to project data onto an automobile’s or plane’s windshield. When one of the world’s top 10 automotive OEM suppliers decided to move to a U.S. manufacturer for their HUD components, EMF’s coating expertise and ability to deliver on time and on budget won their the business.
A typical HUD contains three primary components: a projector unit, a combiner, and a video generation computer. The projection unit in a typical HUD is an optical collimator setup: a convex lens or concave mirror with a Cathode Ray Tube, light emitting diode, or liquid crystal display at its focus. This setup produces an image where the light is collimated, i.e. the focal point is perceived to be at infinity. Cold mirrors are often used as the concave mirror. Cold mirrors reflect visible light and allow the transmission of infrared radiation. In general, these mirrors are used at an angle of incidence of 45°, thus reducing the temperature load from a light source by heat-light separation, which is important for applications where the light source is in close proximity to the mirror like in HUD.
The combiner is typically an angled flat piece of glass (a beamsplitter) located directly in front of the viewer, that redirects the projected image from projector in such a way as to see the field of view and the projected image at the same time. The computer provides the interface between the HUD (i.e. the projection unit) and the data to be displayed and generates the imagery and symbology to be displayed by the projection unit.
The Search for U.S. Cold Mirror Manufacturers
When Japanese automotive manufacturers moved the bulk of their assembly for the U.S. market from Japan to the U.S., they were still relying heavily on Japanese suppliers for many of their more technical components. One of these parts was the cold mirror. A few years ago, they decided to identify a U.S. manufacturer who would give them the advantages of having a local manufacturing and could maintain the incredibly demanding delivery and quality requirements. EMF seized this opportunity and developed a new coating technology designed to meet the specifications of the Japanese car manufacturers. This technology breakthrough was derived from cold mirrors used in dental applications, of which EMF is one of the largest suppliers in the world.
EMF Wins Business
EMF’s very first round of product met all quality requirements and was competitively priced. Consequently, EMF’s product was chosen by the top 10 global automotive OEM supplier to be the cold mirror of choice starting in the 2014 model year.
Additional Applications for Coating Technology
The coating technology EMF uses for the cold mirrors is also applicable to a variety of solar and alternative energy technologies. EMF engineers are exploring these applications now.