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Projector Vs TV, How does a projector work?

What DLP projector means?

DLP stands for 'Digital Light Processing' and what DLP projector means is a projector using a DLP chip to display the projector images. DLP Technology was invented by Texas Instruments. The picture in a DLP projector is produced by light reflecting off a Chip which has millions of tiny mirrors fixed on it. This chip is commonly known as a 'Digital Micromirror Device' or DMD. Each mirror in the DLP projector's DMD Chip represents one pixel in the digital image, so for example, in a HD DLP DMD chip there will be 1920x1080 or a little more than 2 million mirrors assembled on the tiny DLP DMD Chip. The DLP chip mirrors vibrates or wobbles to either reflect the light beam to the final image or reject the light falling on it.

3 chip DLP projectors can process individual beams of RGB light simultaneously and are capable of producing high quality images which are bright. Most cinema theaters use 3 chip DLP projectors to show movies.

The cheaper Home and portable DLP projectors use only one DLP Chip and processes the RGB light sequentially one after the other with the help of a high speed rotating color wheel, as shown in the animation here (from https://commons.wikimedia.org).

How DLP color wheel works

A single chip DLP picture is actually a sequence of partial pictures of Red, Green and Blue picture frames. Due to the Persistence of Vision of our eyes, our brains assume it is a complete picture. Some people have problems watching films or videos on a DLP projector. They see the different RGB color, and this is called 'Rainbow Effect'. The Rainbow Effect problem of DLP Projectors is explained further down on this page.

The animated image here shows how the DLP color wheel works. When white light passes through this colored glass, for example through Red glass, Green and Blue light in the white light is blocked and only Red light is allowed to pass through. Similarly at the Green section of the color wheel, only Green light passes through and in the Blue section only Blue light passes through. So in one complete revolution only ⅓ of the total white light has passed through the DLP color wheel. Thus in a single chip DLP projector, only ⅓ of the total white light source passes through for processing in the single chip DLP projector.

So if the lumen spec of a DLP single chip projector says the projector lamp is 3000 Lumens, the picture it shows on the screen is only using 1000 lumens or ⅓ of the total white light source. An 3000 Lumen LCD projector on the other hand using 3 LCD chips shows a picture on the screen using all the 3000 Lumens and will be much brighter. A 3 Chip DLP projector will also be bright and will utilise the full 100% input Lumens, but 3 Chip DLP projectors are much more expensive than a 3 Chip LCD projector.

DLP Vs LCD projector which is better?

To know which projector is better DLP or LCD, we will use a table to compare LCD Vs DLP projector advantages and disadvantages and the difference between LCD and DLP projectors. From this table it is easy to draw your own conclusion as to DLP or LCD which is better.

DLP or LCD projector which is better?
FeaturesDLP Projector Pros and ConsLCD Projector Pros and Cons
SizeDLP projectors are smaller, lighter and more compact than LCD projectorLCD Projectors tend to be bigger and slightly heavier than DLP projectors
PriceDLP projectors are usually cheaper than comparable LCD projectorLCD projectors tend to be more expensive than similar DLP projectors
Contrast RatioDLP Projectors have better Contrast ratios than LCD Projector.LCD projectors cannot match the contrast ratios produced by DLP but modern LCD projectors have high contrast ratios, and even though the contrast ratio figures may be far apart, viewing actual images between DLP and LCD projectors side by side, you will struggle to notice any difference between DLP and LCD projector contrast ratios.
BrightnessDLP projectors tend to be less brighter than LCD projector because the light is sequentially split into RED, Green and Blue light, so only one-third of the DLP projector lamp lumens strike the projector screen at a time. So DLP projectors need to be played in darkened rooms.In LCD projector there are three separate LCD elements and all of the light from the LCD projector lamp falls on the screen, so 3LCD projectors have three times the screen brightness compared to a DLP projector with the same Lumen rating. LCD projectors can be viewed in rooms which have some ambient light.
Rainbow effectSome persons may experience Rainbow effects while watching DLP projector images. The rainbow effect is caused by not having the red, green and blue coloured images from a DLP projector on the screen at the same time.In an LCD projector, the red, green and blue images on the screen are superimposed over each other at the same time. So no rainbow effect in an LCD projector and the LCD image is three times brighter when compared to a DLP projector with the same lamp lumens.
MaintenanceThe DLP Chip and the whole light path in DLP projectors are sealed and no dust can get in. Thus maintenance on DLP projectors are less than in an LCD projector, even though DLP projector has more moving mechanical parts like the high speed color wheel and the DMD DLP ChipIn an LCD projector, the optical path is not sealed and could lead to dust in the light path if the air filter in the LCD projector is not properly sealed. Also the Air filter in an LCD projector needs to be cleaned at regular intervals depending on how dusty the environment is. In normal household once in 2 to 3 months would suffice.

What is the Rainbow Effect on DLP projectors

What DLP Rainbow effect means is that some people who watch single Chip DLP projectors with a color wheel, feel as if they are seeing Red, Green and Blue flashes of light, while watching or even after they stop watching DLP projector pictures. These illusionary flashes of bright colors are called the Rainbow Effect. The cause of the Rainbow Effect is because the single DLP projector shows the Red, Green and Blue portions of every frame in the video image separately and in quick succession. Because our brains processes these rapid sequences of separate RGB pictures as one, due to our persistence of vision, some people experience the Rainbow Effect which confuses them. People experiencing Rainbow Effect with DLP projectors do not enjoy watching it.

Single DLP Chip LED and Hybrid LED/Laser Projectors does not seem to suffer from this problem so much as single chip DLP projectors using a color wheel./p>

Different kinds of DLP projectors

There are two main types of DLP projectors based on the number of DLP DMD chips it has - Single Chip DLP or Three Chip DLP. Single-chip DLP projectors are the most common type of home projectors and produce sharp images. Three chip DLP projectors are very expensive and mainly used in Cinema theaters. Then there are DLP projectors having different types of light source like LED or Laser instead of the ordinary Lamps. A further subdivision of DLP projectors is based on the number of pixels or micro mirrors on the DLP DMD. In 2020, the latest DLP chips come in two main versions, either full HD or UHD 4K chips which convert HD images to 4K images using TI's proprietary XPR pixel shifting technology.

Single-chip DLP projectors work by splitting white light from the source projector lamp into its component Red Green and Blue (RGB) colors with the use of a color-wheel or have colored LED or Laser as the light source. The timing of the DLP chip and color wheel has to be perfectly synchronized so that the correct color micro mirrors in the DLP chip reflect the right color from the color wheel to the screen.

4K DLP chips for Projectors

As of now DLP chips for projectors are exclusively made by American Company Texas Instruments (TI). There is hardly any 3 chip DLP home projector or even Native 4K home projector available in 2020. Now almost all DLP projectors are made with a Single DLP Chip. The single chip DLP projectors have come a long way and the new trend in 2020 for home projectors is to use the TI XPR pixel shifting technology to produce on screen true 4K pictures with 8.3 million pixels from a full HD single chip DLP. TI makes three models of Single Chip DLP DMD for 4K home projectors. The 3 Texas Instruments DLP® 4K UHD DMD chips are: DLP660TE, DLP470TE and DLP470TP. The 4K DLP chip DLP660TE has a diagonal size of 0.66 inch and has a frame rate 120Hz. Both the 4K DLP chips DLP470TE and DLP470TP have a diagonal size of 0.47 inch but DLP470TE has a frame rate 120Hz and the DLP470TP only has a frame rate 60Hz. The higher end home theater DLP projectors use a 0.66 inch Chip and the cheaper ones use the 0.47 inch Chip.

The final on screen display resolution of all these TI 4K DLP chips is 3840x2160 or full 4K UHD, but the native resolution of all of them is only 1920x1080. They achieve the higher true 4K resolution with 8.3 million pixels by making use of the Pixel shifting technology from TI known as XPR.

What is Color Brightness and White Brightness mean

The White Brightness of a projector is the Lumen output from the light source of the projector, in most cases the brightness of the UHP (Ultra High Performance) Mercury Arc Lamp. Most projector manufacturers claim their Lumens based on the White Brightness Lumen output of the lamp in the projector. The Color Brightness of a projector is the Output Lumens of the light beam from the projector lens which is actually forming the picture on the screen. Obviously we should be more interested in the Color Brightness of a projector which forms the actual picture on the screen rather than how much light is produced by the lamp.

To get a digital colored image on the screen, all Digital projectors split each frame of a video image into its individual basic RGB color images, then pass corresponding Red, Green and Blue light beam through each split RGB color frame and eventually recombine the individual beams of RGB into one beam of light and project on to the screen to form a color image. The strength or Lumens of this final beam of light striking the projector screen to form the image is the Color Brightness of the projector.

What is the difference between DLP Vs LCD projectors and which projector is better?

The main difference between DLP and LCD projectors is in the way they form the image to be output on the screen. Both the 3LCD and DLP projectors using normal white light Lamps split the white light to its individual RGB colors and then pass it through either a LCD or DLP chip to produce individual frames of a video.

To explain how all projectors work, we will take the example of a 24 frame per second video. So in every second, 24 frames of separate individual images have to be projected on to the screen. Each of these 24 frame images need to be split into 3 frames each of its individual basic RGB colors and the corresponding Red, Green and Blue light passed through them and the three separate RGB image light beams recombined into one final beam of light which is projected on to the screen.

In a 3LCD projector there are 3 LCD chips, one each for R, G and B colors. Each of the 3 LCD chips gets the correct R,G or B frame simultaneously at the same time for 1/24 of a second. During this time, the correct color light is passing through the frame continuously for all of the 1/24th of a second. Then the 3 colored image light beam outputs from each of RGB LCD chips are re-combined back into a single image light beam with the use of prisms and projected onto the screen.

In a DLP projector the RGB color beams are intermittently generated through the DLP color wheel and the color wheel and DLP chip has to be synchronized so that when the Red color beam strikes the DLP chip, the right mirror formation is there to reflect and project the Red portion of the video frame image on to the screen, Similarly for the Green and Blue portion of the picture, the right color light beam has to strike the DLP chip with the right mirrors reflecting the right color image on to the screen. This means that for each of the 24 frames per second, 3 separate RGB frames are projected onto the screen or 24x3=72 images of individual RGB colors are projected to the screen per second. Of these 72 images per second 24 are Red, 24 are Green and 24 are Blue. While the Red image is being shown No Green or Blue image is shown, because while the DLP chip is reflecting the Red color image, the Green and Blue portion of the light is blocked by the DLP color wheel and so 2/3 of the light spectrum is being wasted. In effect DLP is using only 1/3 of the available light to project a picture on the screen. This means that a 3LCD projector has 3 times more color brightness than a DLP projector.

This is why some projector manufacturers, especially Epson which makes 3LCD projectors, widely publish that their projectors produce 3 times the color brightness of competing DLP projectors.

DLP LED Hybrid Projectors

Single Chip DLP LED and Hybrid LED/Laser Projectors are now becoming cheaper and quite common. The picture quality is good and the brightness good enough in darker rooms.

DLP Hybrid Projectors overcome the brightness issue that always plagued the LED only projectors. The Achilles heel in the pure LED only projector was that the Green LED could not be made bright enough. Since White light requires that the brightness of all three RGB colors have to be of equal intensity, the full power of the Red and Blue LEDs could not be used in pure LED only projectors. The intensity of the green LED was the limiting factor.

Now comes the Hybrid projector where they use a Laser to produce a bright Green light and this allows the Red and Blue LEDs to be fired up to their maximum brightness. End result, a bright Hybrid Projector using solid state lighting with all the advantages of reliability, long lasting bulbs or light source, etc. ...For more visit our page on the different light sources for projectors.

Where to buy Home Theater Projectors and Projector Screens online

The best place to buy Projectors and Projector screens is the Amazon online store in your country. Amazon is best to buy online Projectors and Screens because not only are they very competitively priced, but you also have the assurance of service, and in the worst case, even return for a refund in case you are not satisfied.

Links for Home Theater Projectors

This is the Link for Home Theater Projectors from Amazon AUSTRALIA

This is the Link for Home Theater Projectors from Amazon CANADA

This is the Link for Home Theater Projectors from Amazon INDIA

This is the Link for Home Theater Projectors from Amazon UK

This is the Link for Home Theater Projectors from Amazon USA

Links for Projector Screens

This is the Link for Projector Screens from Amazon AUSTRALIA

This is the Link for Projector Screens from Amazon CANADA

This is the Link for Projector Screens from Amazon India

This is the Link for Projector Screens from Amazon UK

This is the Link for Projector Screens from Amazon USA



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