Saturday, November 29, 2008

DLP technonogy

DLP TechnologyDLP technology is based on an optical semiconductor, called a Digital Micromirror Device (DMD), which uses mirrors made of aluminum to reflect light to make the picture. The DMD is often referred to as the DLP chip. The chip can be held in the palm of your hand, yet it can contain more than 2 million mirrors each, measuring less than one-fifth the width of a human hair. The mirrors are laid out in a matrix, much like a photo mosaic, with each mirror representing one pixel.
When you look closely at a photo mosaic, each piece of it holds a tiny, square photograph. As you step away from the mosaic, the images blend together to create one large image. The same concept applies to DMDs. If you look closely at a DMD, you would see tiny square mirrors that reflect light, instead of the tiny photographs. From far away (or when the light is projected on the screen), you would see a picture.
The number of mirrors corresponds to the resolution of the screen. DLP 1080p technology delivers more than 2 million pixels for true 1920x1080p resolution, the highest available.
In addition to the mirrors, the DMD unit includes:
A CMOS DDR SRAM chip, which is a memory cell that will electrostatically cause the mirror to tilt to the on or off position, depending on its logic value (0 or 1) A heat sink An optical window, which allows light to pass through while protecting the mirrors from dust and debris DLP ProjectionBefore any of the mirrors switch to their on or off positions, the chip will rapidly decode a bit-streamed image code that enters through the semiconductor. It then converts the data from interlaced to progressive, allowing the picture to fade in. Next, the chip sizes the picture to fit the screen and makes any necessary adjustments to the picture, including brightness, sharpness and color quality. Finally, it relays all the information to the mirrors, completing the whole process in just 16 microseconds.
The mirrors are mounted on tiny hinges that enable them to tilt either toward the light source (ON) or away from it (OFF) up to +/- 12°, and as often as 5,000 times per second. When a mirror is switched on more than off, it creates a light gray pixel. Conversely, if a mirror is off more than on, the pixel will be a dark gray.
The light they reflect is directed through a lens and onto the screen, creating an image. The mirrors can reflect pixels in up to 1,024 shades of gray to convert the video or graphic signal entering the DLP into a highly detailed grayscale image. DLPs also produce the deepest black levels of any projection technology using mirrors always in the off position.
To add color to that image, the white light from the lamp passes through a transparent, spinning color wheel, and onto the DLP chip. The color wheel, synchronized with the chip, filters the light into red, green and blue. The on and off states of each mirror are coordinated with these three basic building blocks of color. A single chip DLP projection system can create 16.7 million colors. Each pixel of light on the screen is red, green or blue at any given moment. The DLP technology relies on the viewer’s eyes to blend the pixels into the desired colors of the image. For example, a mirror responsible for creating a purple pixel will only reflect the red and blue light to the surface. The pixel itself is a rapidly, alternating flash of the blue and red light. Our eyes will blend these flashes in order to see the intended hue of the projected image.
A DLP Cinema projection system has three chips, each with its own color wheel that is capable of producing no fewer than 35 trillion colors. In a 3-chip system, the white light generated from the lamp passes through a prism that divides it into red, green and blue. Each chip is dedicated to one of these three colors. The colored light that the mirrors reflect is then combined and passes through the projection lens to form an image.
Texas Instruments has created a new system called BrilliantColor, which uses system level enhancements to give truer, more vibrant colors. Customers can expand the color scope beyond red, green and blue to add yellow, white, magenta and cyan, for greater color accuracy.
Once the DMD has created a picture out of the light and the color wheel has added color, the light passes through a lens. The lens projects the image onto the screen.

1 comment:

Ankit Vora said...

you made my insight to the DLP's
i was looking forward to get this
thanks sir.