LCD

DLP

How does a projector work

The operation of today's projection systems is based on receiving an electric signal (either analog or digital) from a data source (computer, VCR, DVD, etc.) transforming the signal into an image, and projecting the image onto a screen. To do this, the signal must first be converted into a digital signal. If sent as analog, it is passed through an analog-to-digital signal converter. The digital signal is now ready to be processed into an image for projection. Currently, there are two technologies used for projecting images: liquid-crystal display (LCD) and Digital Light Processing™ (DLP).

LCD

Here, the digital signal is processed to polysilicon panels. A light source is passed through a series of dichroic mirrors to separate the various color wavelengths and then through the polysilicon panels where activated pixels process the light into a final compiler before projection through the lens and onto the screen.

DLP

Here, the digital signal is processed to a DMD™ chip. The light source is passed through a color wheel and onto the DMD™ chip, and is then reflected off the chip through the lens and onto the screen. The introduction of this rather new technology has led to the further miniaturization of projection systems.