Not many technologies survive for more than a

Century, but one that has – analogue

projection – is finally facing its demise.

Digital technology is set to take over virtually every

form of image projection of which you can think.

Within a decade, analogue projectors could be

museum pieces.

Leading the way are three key markets: cinema;

home projectors; and large hdtvs. But entirely new

markets are also set to open up.

Today, cinema is arguably the most exciting area

for digital projection. Not only does it replace the

35mm projector, it also enables a movie to be

distributed via hard drives, dvds or satellite. Digital

projection provides superb quality that never

deteriorates and hugely attractive economics. Let’s

compare production costs: 4000 prints of a movie can

cost around $5million. Yet, at the specified data rate

of 250Mbit/s, the same movie typically fits on a

300Gbyte hard drive costing around $70. With several

hundred movies distributed every year, industry

savings could reach $1billion or more.

But the switch to digital in the cinema has not

happened quickly. The overwhelmingly dominant

technology used in digital projectors – Texas

Instruments’ Digital Light Processor (DLP) – has been

available for more than 10 years. Yet it was only in

2002 that the six leading Hollywood studios set up

the Digital Cinema Initiatives (DCI, www.

dcimovies.com) to specify industry standards for

digital cinema, published eventually in June 2005.

DCI requires pictures to be encoded using the

JPEG2000 standard and use of the CIE XYZ colour

space at 12bit per component into a Material

Exchange Format (MXF) compliant file at a maximum

data rate of 250Mbit/s. Audio, meanwhile, is handled

using the .wav format at 24bit and sampling at 48 or

96kHz. Three levels of playback are supported: 2K

(2048 x 1080 pixels) at 24frame/s, by far the most

common; 4K (4096 x 2160) at 24frame/s; and 2K at

48frame/s. Projectors that fail to meet these

standards cannot show the Hollywood studios’

content.

The establishment of industry standards means

Binarybreaks through

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After a long

gestation period,

digital projection is

set to break into

the mass market.

By David Boothroyd.

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digital projection in cinemas is set to take off. Indeed,

David Hancock, head of cinema for Screen Digest,

believes it started to happen as soon as the DCI

recommendations appeared.

“Our figure for takeoff of digital cinema shows it

started in June 2005, when there were less than 1000

digital screens. By the end of 2007, there were 6456, a

rise of 155% over 2006. This represents 6.5% of the

world’s modern screens, with nearly 1000 in Europe.”

For the electronics industry, it is unusual for a

technology to establish such overwhelming dominance

as that achieved by TI’s DLP in digital cinema

projection. Three manufacturers make DLP cinema

projectors – Christie Digital, Barco and NEC – between

them, controlling 99% of the market.

Rapidly moving mirrorsInvented in 1987 by Dr Larry Hornbeck, the DLP

technique creates images by rapidly moving

microscopic mirrors laid out in a matrix on a

semiconductor chip – the Digital Micromirror Device

(DMD). The number of mirrors corresponds to the

resolution of the projected image.

The first DLP projectors were aimed at business

applications and shipped in early 1996. A milestone

for DLP in cinema was George Lucas’ production of the

first all digital version of Star Wars Episode 1. Even in

its early days, DLP was a remarkable technological

achievement but, ever since, there have been

continuous improvements, according to John Reder,

TI’s EMEA Business Development Manager for Front

Projection.

First is brightness. The first projectors provided

250 to 300 lumens, today the average is 2500, but

several thousand is achievable. For resolution, the

standard was svga at 800 x 600 pixels. Today, a typical

top standard offers 1920 x 1200. In terms of contrast,

the cutting edge was a ratio of a few hundred to one,

today it is several thousand to one.

“Another important development is that inside the

chip we have shrunk the pixels several times, which

means we can put more mirrors in the same die size,”

says Reder. “That increases resolution and also cuts the

cost and size, not only of the chip but also of the optics

that go round it.”

Interestingly, this has not depended on state of the

art semiconductor advances. “The mirrors themselves

are quite large compared with today’s semiconductor

elements and this is helpful because it enables us to

produce wafers for DLP chips on depreciated

fabrication lines,” Reder says. “But we have achieved a

much better understanding of exactly how the mirrors

move and this has enabled us to shrink them.”

A similar story applies to contrast – detailed

analysis of the mirrors’ performance has shown what

contributes most to scatter, enabling TI to eliminate

most of these effects.

Despite its dominance, DLP is not the only

potential technology for cinema projection. Sony, for

example, has recently developed a 4k liquid crystal

based projector featuring SXRD (Silicon X-tal

Reflective Display) technology, with exceptionally

high pixel density.

“A combination of radically new design for silicon

driving circuit technology and new silicon wafer

process and liquid crystal device technology enables

2m pixels with a pitch of 9µm to be arranged just

0.35µm apart,” Sony says. “Compared with high

temperature polysilicon liquid crystal devices, this

represents a 2.4 fold increase in pixel density and a

tenfold improvement in interpixel spacing.”

But Sony’s market share is currently tiny, with only

a handful of cinemas worldwide equipped with 4k

projectors. And it faces a major obstacle: once a

standard like 2k is established, it will be years before

changes are contemplated. Could the 2k standard be

found wanting and supplanted by 4k? Hancock says no.

“Certainly not in the short to medium term. Once

you create a business model around the costs of a 2k

projector, people will not change for years – deals

now being done are for 7 to 10 years. As with 35mm

film, once a standard is set, it stays. Also, the 2k

standard provides excellent image quality on today’s

screens, so moving to 4k would make little difference.

Massive screens, say 25 to 30m, might benefit from

4k but even on these 2k is very good.”

The largest cinema screen of all is IMAX, and this

has started the switch to digital using a specially

developed dual projection DLP projector,

combined with advances from IMAX that

double the light output compared with

conventional digital projection,

increasing dynamic range

and contrast. IMAX has

just announced a deal

with Regal in the US to

install 31 IMAX digital

systems in 20 major

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C O V E R S T O R Y

Digital projection

The 115g Optoma Pico

Pocket Projector can project

an image up to 100 times

larger than the screen of the

source device and over

distances of up to 2.6m

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centres. The first of these are expected to open in

time for the November 21 release of Harry Potter and

the Half Blood Prince: the IMAX Experience.

“IMAX has been rejuvenated by the whole digital

revolution,” Hancock says. “It enables them to do

more with their screens, showing events like opera

and sport, for example, and also 3d.”

And there lies another cinematic revolution which

digital projection is making possible.

“3d has been waiting for digital,” Hancock says.

“Analogue 3d was awful, but digital is excellent and is

here to stay.”

3d content is growing fast. Screen Digest is

tracking 51 3d projects, 33 of which have a release

date over the next couple of years, and major

directors like James Cameron and Jeffrey Katzenberg

are advocates, whilst Dreamworks has committed its

entire output to 3d. Other studios now accept 3d is

here to stay – something few did before – and Screen

Digest forecasts that 15 to 20% of all screens will

eventually be 3d. Currently, it is estimated that there

are 1300 3d screens worldwide.

There are three basic formats for 3d: Dolby 3D;

Real D; and active glasses. But, as Hancock says, the

industry wants to reach the point where any 3d film

can be shown on any 3d screen. To achieve this, DCI is

currently working on a 3d update to its standards.

“One attraction for Hollywood is that 3d screens

are rapidly outselling 2d screens in the same

multiplex venues, and at higher ticket prices,” says

Reder. “Without question, it is the technology that is

making 3d attractive, compared with the past.”

TI’s 3d DLP technology is now moving into hdtvs

and front projectors. This move, being pioneered by

Norwegian company Projection Design, is targeting

higher end business to business applications.

Two different methods are used to achieve 3d

using DLP. For front projectors and tvs, the system

works at 120Hz, giving 60 images each for left and

right. Then shutter glasses are used that are

synchronised to the image. Because DLP switches in

the order of microseconds, it is possible to switch

from left to right extremely quickly. This provides

very high separation, which eliminates the blurring

that was always a problem for past analogue 3d.

The cinema uses an additional system made by

Real D, sold with the DLP projector – based on a push-

pull electro optical modulator called the ZScreen

invented by Lenny Lipton – along with polarised

glasses. The projector alternately projects the right-

left frame and circularly polarises these frames,

clockwise for right, anticlockwise for left, using a

liquid crystal screen placed in front of the projector

lens. The polarised glasses make sure each eye sees

only ‘its own’ picture. And, with a frame rate of 72

frame/s per eye, the image looks continuous.

What of the future for DLP?LED based lamp free projectors, one major route

forward, are already gaining market share in two

areas – large hdtvs and pocket projectors. The latter

are extremely compact units that are already

providing around 150lumen and which can run a full

dvd film off a battery.

“For LEDs to take more of the front projector

market, they need to offer increased the brightness

and lower cost,” says Reder, “and they are definitely

heading in that direction. At Infocom in Las Vegas

this June, we demonstrated an led DLP projector

intended for home theatre that offers 500lumen.”

Another fascinating development for digital

projection is the pico projector, for which TI has

developed a DLP Pico chipset. Using this, Optoma has

developed its Pico Pocket Projector. Smaller than

most smartphones, it fits in the palm of a hand and is

the ideal companion to portable media devices such

as iPods, pdas, smart phones and digital cameras.

When connected to such devices, the 115g

Optoma Pico Pocket Projector can project an image up

to 100 times larger than the screen of the source

device and over distances of up to 2.6m.

The product will be available in limited

distribution in Europe and Asia in late 2008, with a

worldwide launch in 2009.

Ultimately, expect to see mobile phones and

portable video players that have projectors built in:

the market potential is clearly enormous. ■

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C O V E R S T O R Y

Digital projection

“3d has been waiting for digital. Analogue

3d was awful, but digital is excellent and

is here to stay” David Hancock, Screen Digest

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Pico projectors are being

positioned as the ideal

companion to portable

media devices such as

pdas, smart phones,

digital cameras and

iPods.

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