With over 70 W of electrical power pumped into the LEDs, it’s important to have a customized thermal solution to dissipate the heat in the LEDs and LED driver circuit board. Texas Instruments and TQ Technology have designed and built a projector capable of meeting the specifications listed in Table 3-1. In order to manage the heat and provide robust performance across the automotive ambient temperature range, fans and heat sinks were added to this projector. As a result, the size of the projector is roughly 130 mm x 130 mm x 170 mm. Figure 3-3 shows the high lumen DLP5532-Q1 projector.

Note that it is possible to optimize the size of the projector in any dimension depending on the mounting location and layout of the vehicle. Additionally, the height of this projector is mainly dictated by the projection lens (which is a function of the throw ratio) and the illumination orientation of the DMD. The DLP5532-Q1 DMD is a bottom-illuminated device, which means the illumination component must be perpendicular to the long edge of the DMD array. With different optical design architecture, it is possible to perhaps reduce the overall height. And in the future, side-illumination DMDs may be available, where the illumination can be rotated 90° relative to the DMD, which will reduce the height of the projector.

This design exercise has shown that a DLP projector can achieve high output optical power of nearly 1,000 lumens. Future optimizations to the projector may be able to increase the power and simultaneously optimize the thermal solution and therefore reduce the overall size.