The semiconductor that continues to reinvent display

At the heart of every DLP projection system is an optical semiconductor known as the DLP chip, which was invented by Dr. Larry Hornbeck of Texas Instruments in 1987. The DLP chip is perhaps the worlds most sophisticated light switch. It contains a rectangular array of up to 8 million hinge-mounted microscopic mirrors; each of these micromirrors measures less than one-fifth the width of a human hair. When a DLP chip is coordinated with a digital video or graphic signal, a light source, and a projection lens, its mirrors can reflect a digital image onto any surface

The grayscale image

A DLP chipís micromirrors tilt either toward the light source in a DLP projection system (ON) or away from it (OFF). This creates a light or dark pixel on the projection surface. The bit-streamed image code entering the semiconductor directs each mirror to switch on and off up to ten thousand times per second. When a mirror is switched on more frequently than off, it reflects a light gray pixel; a mirror thatís switched off more frequently reflects a darker gray pixel. In this way, the mirrors in a DLP projection system can reflect pixels in up to 1,024 shades of gray to convert the video or graphic signal entering the DLP chip into a highly detailed grayscale image.

Adding color

The white light generated by the light source in a DLP projection display system passes through a color filter as it travels to the surface of the DLP chip. This filters the light into a minimum of red, green, and blue, from which a single-chip DLP projection system can create at least 16.7 million colors. With BrilliantColorô Technology, additional colors are added including Cyan, Magenta and Yellow to expand the color palette for even more vibrant color performance. Many DLP projection display systems offer solid-state illumination which replaces the traditional white lamp. As a result, the light source emits the necessary colors eliminating the color filter. In some DLP systems, a 3-chip architecture is used, particularly for high brightness projectors required for large venue applications such as concerts and movie theaters. These systems are capable of producing no fewer than 35 trillion colors. The on and off states of each micromirror are coordinated with these basic building blocks of color. For example, a mirror responsible for projecting a purple pixel will only reflect red and blue light to the projection surface; those colors are then blended to see the intended hue in a projected image.

Breadth of applications

From large cinema projection systems to handheld mobile display enabled by DLP Pico, DLP technology is the most flexible digital display in the world. Developers are also leveraging DLP display in new ways for categories such as industrial, medical, security and automotive solutions. Regardless of the application or design, display systems powered by DLP Technology continue to harness life to solve real-world problems. And it all starts with a small imaging chip with millions of tiny mirrors called DLP.

By Prasanna Kumar

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