Test, teardown and comparison of two DLP projectors. The Vivitek WD755 is from around 2013 and the older InFocus is from around 1998. They are both based on the Texas Instruments DLP chipsets and the technology and space it takes up, shows that there is little difference in the physical size, but the higher resolutions is solely found in the smaller sized digital micro mirror devices.
How does DLP projectors work
Digital Light Processing (DLP) is a set of chipsets based on optical micro-electro-mechanical technology. The main component is the digital micromirror device, named DMD. It was originally developed in 1987 by Larry Hornbeck of Texas Instruments.
In these projectors with single DLP chips, colors are produced by placing a color wheel between a white lamp and the DLP chip. The color wheel has four divisions. The primary colors red, green, blue and white (clear). The DLP chip is synchronized with the rotation of the color wheel, so that each color component is displayed on the DMD when the corresponding division of the color wheel is in front of the lamp. The colors are displayed sequentially at a high enough rate, that the observer sees a composite full color image. In early models, it was synchronized to one rotation per frame. Now, most systems operate at up to 10 timer the frame rate.
What is inside a DLP projector
There is basically fours parts inside a DLP projector. There is a lamp, optical parts, power supply and main circuit board. The light sources are almost all xenon arc lamps from these generations. The optical parts are very identical, there has been little to none development in optical parts and color wheel technology, when speaking of shape and size. The DLP branded chipsets are spread out all over the main circuit board that has all input and output processing right next to the DLP environment, audio amplifier and other features.
Projector lamp power supply also has the house keeping supplies and the special Xenon arc lamp power supply module that outputs 75 VDC.
The optical parts are quite similar, the light source, color wheel, tunnel, optics and output lens is about the same. All the difference between the old unit and new ultra short distance unit is the output lens or the mirror.
All the different parts from the light source to the output lens is spread out.
Some more detailed Digital Micromirror Device pictures that show the mechanical buildup and microscope pictures. With my own stereomicroscope, it was NOT possible to spot individual mirrors that can be down to 5.4 um in size.
DLP images from TI DLP website press images: https://www.ti.com/dlp-chip/overview.html and http://www2.optics.rochester.edu/workgroups/cml/opt307/spr05/john/