A High-Dynamic Range Projection System

The dynamic range in many real-world environments surpasses the capabilities of traditional display technologies by several orders of magnitude. Recently, a novel display capable of displaying images with a dynamic range much closer to real world situations has been demonstrated. This was achieved through a spatially modulated backlight behind an LCD panel. Combined with the modulating power of the LCD panel itself, this enabled the display of much higher contrast compared to an LCD panel with a spatially uniform backlight. In this paper, we describe a further development of the technology, namely a high dynamic range projection system. This makes such display systems more widely applicable as any surface can be used for the display of high dynamic range images. Our new system is designed as an external attachment to a regular DLP-based projector, which allows the use of unmodified projectors. It works by adapting the projected image via a set of lenses to form a small image. This small image is then modulated via an LCD panel and the result is projected via another lens system onto a larger screen, as in traditional projection scenarios. The double modulation, by the projector and the LCD panel together, creates a high dynamic range image and an ANSI contrast of over 700:1. Finally, we discuss the advantages and disadvantages of our design relative to other high and low dynamic range display technologies and its potential applications.