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How do DLP technologies work?

by Amit Yadav Asyd

DLP stands for Digital Light Processing. It is a technology developed by Texas Instruments in 1987. DLP technologies are used in projectors for projecting content. The first-ever DLP-based projector was created by Digital Projection Ltd in 1997. It is widely employed in standalone projectors and digital signs. Also, most of the Pico projectors are made based on DLP technology.

How DLP Technologies work

Every DLP projection system uses a DLP chip. It is an optical semiconductor which was invented by Texas Instruments in 1987. The chip can vary in size. It contains over eight million micro-mirrors. It differs in resolution as well. DLP technology uses white light source for projecting content. These micro-mirrors are tilted towards or away from the light source. This principle is used for projecting content. Let us discuss this topic in details.

As it is mentioned in the context, DLP technology uses white light source for projecting content. Additionally, some filtering techniques are utilised for the same output. Micro-mirrors are used on chips where light is directed from the white light source. These mirrors control the light and dark pixels on the projection surface. In a nutshell, they control the brightness level of each pixel.

Micro-mirrors have ON and OFF state. When light is directed towards the light source, it is in ON state where pixel gets brighter. When the light is directed away from the light source, it is in OFF state where pixel gets dimmer. Mirrors switch rates up to thousand times per second. Red, green and blue light is shone on the mirrors, the state turns ON and OFF as per the input. Light is reflected by the mirrors and is directed through a lens onto the screen.

Also, these mirrors control the colour effect on each pixel. A colour wheel is used for this purpose. The wheel splits light into primary colours: Red, Green and Blue. It is placed between the light source and the mirrors. Colour wheel decides the colour to be projected on the designated pixel as per the input.

 Pros

  • DLP projectors produce still images on the screen.
  • DLP projectors have a wider colour gamut as it can process up to 7 different colours.
  • TVs which use DLP technology have lighter weight compared to LCD and Plasma TVs.
  • Devices that use DLP technology for projection has excellent ANSI contrast.
  • The light source used in DLP technologies can be easily replaced with another light source unlike the backlights used in LCDs. This also ensures a prolonged life for the device compared to other TV sets which use different technologies.
  • The light projected by DLP projectors on the screen is not inherently polarised.
  • LCD and Plasma TVs rely on fluids as a projection medium which limits their quality of projecting content. However, DLP technology has no such issue because of their mirror mechanism. This fact is the reason why they project higher quality content.

Cons

  • The rainbow effect might act as a setback and disturb viewers during the projection.
  • Devices who use DLP technology consume more power compared to other devices.
  • Certain devices use lamp based DLP units. The cost for replacement of these lamps is high. However, new units use LED chips or lasers to eliminate this con. You can always opt for a newer LED/Laser-based DLP unit.
  • Plasma and LCD TVs are relatively thinner than DLP TVs.
  • DLP-based devices are noisy. However, the issue has been cleared for many new types of equipment. High pitch whine of the colour wheel is annoying, but the system can be engineered to be in the silent mode to avoid any such noise. Also, the construction of newer units eliminates this issue.
  • DLP projectors are not focus free.

About Amit Yadav Freshman   Asyd

8 connections, 0 recommendations, 31 honor points.
Joined APSense since, July 24th, 2016, From Rewari, India.

Created on Dec 31st 1969 18:00. Viewed 0 times.

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