From being something that was associated with films at cinema halls, the projector has today become an integral part of our digital lives. We take a closer look at the current technologies in the projector market and its future.

From OHD to DLP to 3LCD
In the beginning, there was the ‘overhead’ projector or OHD. Then came the CRTs, which introduced people to the concept of big-screen video. They used three tubes (known as colour wheels) of the primary colours—red, green and blue (RGB), which converged to make an image. However, they did not have a fixed number of pixels, resulting in various native resolutions. They were also large in size, consumed a lot of power and needed a lot of maintenance. Thus, the quest for a more effective technology continued.

Things started changing in the 90s with the coming of DLPs (digital light processing) and LCDs (liquid crystal display).

DLP technology makes use of a Digital Mirror Device (DMD) chip. This chip comprises thousands of microscopic mirrors, each acting as a single pixel. These mirrors wobble back and forth, directing light either into the lens path to turn the pixel on, or away from the lens path to turn it off. It is a reflective technology. On the other hand, LCD projectors have panels instead of mirrors. They act as a prism with pixels that allow the RGB light through. As light passes through the panel, the pixels can open to let the light pass or remain closed to block its path. Hence, it is a transmissive technology.

The new millennium saw the coming of LCOS, also known as liquid crystal over silicon, and 3LCDs—an enhanced version of LCD. LCOS is a combination of LCD and DLP technology. As the name suggests, the liquid crystals are applied over the silicon, which wobble back and forth, directing light either into the lens path or blocking it. Hence, it is more of a reflective technology. Even though it may seem relatively simple conceptually, industry experts feel that it is a difficult technology to master.

3LCD is the latest technology introduced in projectors from Epson, and has attracted a lot of attention. This is because it allows the true expression of colours. Similar to LCD projectors, 3LCD allows light to pass through each panel. The pixels also can open to let light pass or remain closed to block its path. However, the distinguishing feature is the change that happens when the colours reach the lamp. Two dichroic mirrors divide the light from the lamp into red, green and blue. This is also known as ‘panel on prism’ technology. The base glass of these two mirrors is coated with a thin film that reflects only light of a specific wavelength. Then the colours and images are recomposed by reflecting red and blue light, and transmitting green light.

Shrinking in size and keeping their cool!
While these light engine technologies were being worked upon, there was always an attempt to make projectors small and portable. Thus, they moved down from ceilings to be placed in storerooms, and finally turned into the swanky models that exist in our meeting rooms today. Apart from size, power consumption and weight are other areas where technological changes have taken place.

Today, projectors use a magnesium casing, which is stronger than plastic, lighter than aluminium, and allows them to withstand the rigours of business travel while remaining lightweight—some models weigh a mere 1.7 kg.

Projectors that use DLP technology consume a lot of power and energy. This is because of the use of microscopic mirrors.

When the projector is in ‘off’ mode, light is directed away from the lens, which causes it to heat up. This is where fans plays a major role. However, with the coming of small forms, the size of the fan has also shrunk.

Nearly all companies, be it Epson, Canon, Panasonic or Sharp, have introduced the ‘direct power off’ feature in their projectors to lower energy costs and keep them cool. The technology allows the projectors’ built-in capacitor to supply continuous power to its internal components, to keep them cool as well as save energy while starting or disconnecting. It also prevents damage to the bulb from insufficient lamp cooling.

Panasonic has a technology called ‘liquid cooling’, wherein a coolant runs through the engine, keeping its temperature frigid.

Epson uses its ‘cooling method’ technology, which works by sensing the temperature at various locations inside the optical engine. This helps in controlling the working temperature and increases the life of the projector.

Switching between lamps and blocking leakages
Lamps have been one of the most important components of the projector —in fact, the working force behind them. Needless to say, they too have attracted a fair share of innovation.

A single bulb, or ‘lamp’ as it is called, was unsuitable for critical presentations. What if the lamp
wore out at the wrong time? It became necessary to supplement the projector with an additional lamp that could handle such situations. So projectors with dual lamps were introduced, but maintaining a smooth transition was difficult. The system of an ‘auto-changer’ was developed to solve this concern.

Panasonic’s ‘BriteOptic’ technology allows two lamps to work together, resulting in greater performance and a long shelf life. Another benefit of this technology is that it ensures the projector will not stop projecting in the middle of a presentation. As soon as one lamp burns out, the auto-changer allows the other one to take over smoothly.
In conventional projectors, if the distance between the lamp and panel was shortened to improve brightness, it resulted in light seepage and
reduced contrast.

To counter this effect, Epson launched its new technology known as E-TORL (Epson-Twin Optimise Reflection Lamp) that eliminates leakage of light and reduces defraction. The system combines an oval reflector, aspherical lens and a hemispherical mirror.
Canon’s AISYS (Aspectual Illumination System) technology also looks into the light leakage aspect. It uses an optical system with a barrel-shaped compressor lens that optimally controls light in the horizontal direction, enabling nearly parallel light to strike the LCOS panels.

Getting colourful
With the growth of options that allow a single image to be portrayed on various devices, the importance of perfect colour output has increased by leaps and bounds. Projectors are no different. Technology has developed rapidly to dissolve the colour
difference between the original
input and the output.

Canon has developed a colour management system known as ‘Kyuanos’. Its three modes—perceptual, saturation and colorimetric—enhance the quality of the image. For example, if the projector is displaying a Powerpoint presentation, the perceptual mode develops the photo colours, while the saturation covers the graphs, pointers, etc. However in this example, colorimetric mode may or may not come into play, as it is used for high-end images, where colour is of paramount importance.

Sharp uses Brilliant Colour technology that enhances the quality of an image. Subtle colours are expressed more brightly. This is done by adding an extra segment of yellow to the existing RGB (red, green and blue) range.

Epson combines its POP technology with its 3LCD technology, giving a very bold and bright image output.

The ‘bright’er side
The projection of real colours is important but would lose its impact if the brightness or contrast of the image is inferior. A perfectly bright image should have 1200-1300 ANSI lumens and a contrast of 800:1. However, some companies have been able to provide brightness as high as 4000 ANSI lumens.

Epson has developed Crystal Clear Fine (C2 Fine) technology, mainly for 3LCD projectors, that enhance aperture ratio, definition, and image quality, making the viewing experience even more real.

Canon, on the other hand, uses its patented memory/vivid colour correction technology that adjusts the degree of brightness of the primary and secondary colours. The projector’s 6-axis (RGBCMY) colour adjustment also fine-tunes the hue and saturation of each of the primary and secondary colours.

Panasonic’s daylight View 2 technology uses an ambient light sensor—as and when the light in the room fluctuates, the sensors grasp the change and make the necessary adjustments.
Present day optical lenses are treated with an advanced anti-reflective coating, to reduce spurious light emission and yield higher contrast images. From the traditional glass lenses the trend is now shifting to plastic lenses. Canon has created low-cost, large-diameter, round plastic optical lenses for projectors. Its patented AISYS technology has a 1.7x optical zoom lens made entirely with lead-free glass elements.

Innovations galore
Another technology used by projectors to optimise viewing is ‘wall correction’ technology. It enables projectors to display colours accurately even when a projection screen is not available, regardless of the wall colours. Present-day projectors provide as many as eight wall colours, including the new Greenboard (Gray) mode, that automatically adjusts colour levels, and images appear as natural as when projected on a white background.

In many presentations, the projector is not set up at an ideal angle to the screen, resulting in what is commonly referred to as the ‘keystone’ effect—where the sides of the presentation start wide and then narrow down toward the bottom. To eliminate this, projectors now come with keystone correction technology. They ensure distortion-free images automatically even when the projector is not angled perpendicular to the screen. Infrared sensors measure the distance and angle of the screen and accurately adjust focus.

Sharp, Canon and Epson projectors use a connectivity technology known as remote management, which allows IT managers to control the projector from another location via a Web browser. The technology also allows the machine to send an error report to the administrator in case of any contingency -- like the expiry of bulb life or disconnection of the unit as a whole. Projectors have also started going wireless. These are based on IEEE 802.11b/g Wi-Fi technology and enable uploading, downloading or running of presentations and movies wirelessly. They also come with an ‘interrupt disable’ feature that prevents other wireless devices in the vicinity from hijacking the projectors.

“The introduction of wireless projectors is possibly the key innovation of the past few years -- projectors getting smaller and more portable, is the next. Third is the improvement in visual clarity, brightness, etc. And fourth is the combination of the projector with the DVD player and speakers to make an all-in-one home theatre. This concept is pretty new in India and is being worked upon. We have already launched it in the Indian market in October last year,” said Tushad Talati, senior manager, Epson India.

A future projection
The future certainly seems to be bright for the projector market. As projectors grow more popular, security becomes an area of concern. Therefore, the technology of password and biometric identification in projectors is expected to grow.

Also, there is a strong trend towards bringing the projector to the household sector.
“Canon has entered the field with its simulation technologies incorporated in its new XEED range. Simulation is the future of the industry and if worked well, can change the way projectors are used,” said Puneet Sabharwal, manager, AV equipment, Canon India.

Epson’s Talati is also optimistic about the future: “We can foresee strong growth for the next few years. The demand for data projectors for corporations and educational institutions does exist, but the household segment will increase. The market for them in India is still very small, but is gradually picking up.”
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The Fraunhofer Institute in Germany has created a projector that is as small as a sugar cube.
Traditional projectors use arrays of millions of mirrors to display footage, but this petite prototype comprises a single tiny mirror. The width of the projector measures less than 16mm, while its height and depth is 9mm. The USP of the projector, apart from its size, is that it can project images onto curved surfaces, such as a dome.
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Epson has developed a prototype postcard-sized mini-projector using an LED light source. With a footprint of just 13.8 cm x 10.3 cm (just smaller than a sheet of A6 paper) and a slender profile, the 500-gm prototype can fit easily into the palm of your hand.
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