One of the most exciting recent advances in home cinema picture solutions has been the development of Digital Light Processing or DLP™ technology.
Cut back to its most basic, DLP™ technology is a display solution that uses an optical semiconductor to manipulate light digitally.
This optical semiconductor is known as the Digital Micromirror Device, or DMD chip, which has been developed by Texas Instruments. The DMD chip contains a rectangular array of up to 1.3 million hinge-mounted microscopic mirrors, with each of these micromirrors measuring less than one-fifth the width of a human hair, and corresponds to one pixel in a projected image.
When a DMD chip is co-ordinated with a digital video or graphic signal, a light source, and a projection lens, its mirrors can reflect an all-digital image onto a screen or other surface. The DMD and the sophisticated electronics that surround it are what we call Digital Light Processing™ technology.
A DMD panel’s micromirrors are mounted on tiny hinges that enable them to tilt either toward the light source in a DLP™ projection system (On) or away from it (Off) -creating a light or dark pixel on the projection surface. The bit-streamed image code entering the semiconductor directs each mirror to switch on and off up to several thousand times per second. When a mirror is switched on more frequently than off, it reflects a light gray pixel; a mirror that’s switched off more frequently reflects a darker gray pixel.
In one-chip projector white light passes through a colour wheel filter, causing red, green and blue light to be shone on the surface of a DMD. The colour wheel spins at 60Hz to give 180 colour fields per second. There are 256 shades for each of the primary colours or 2653 Â 16.7 million Â possible colours can be generated.
However, for the ultimate picture performance one must look to a 3-Chip solution.
In a 3-chip system white light is passed though a prism that divides the light into red, green and blue. Each DMD chip is dedicated to a primary colour. The red, green and blue reflections from the three chips are combined and passed through the lens to create an image. And the 3-DMD chip system found in DLP Cinema™ projection systems is capable of producing no fewer than 35 trillion colours.
Ah, perfection at last. Well, not quite.
Sadly, most 3-Chip designs thus far have tended to be hugely expensive, incredibly bulky and not what you could call attractive.
But 3-Chip DLP™ technology is on the move, with designs becoming smaller, lighter and less expensive. A wonderful example of this more consumer friendly 3-chip design is the new C3X projector from world leading DLP™ specialists SIM2.
The C3X is the worldÂ¹s smallest and lightest 3-Chip projector. And as befits any projector with Italian pedigree it is undoubtedly the most beautiful, too. The C3X measures a mere 43 x 43 x 19cms, roughly a third of the size of a typical 3-Chip projector, and at 8.8kgs the C3X is almost 75% lighter than most 3-Chip units.
To achieve such radical figures, an intensive R&D programme was undertaken. The result is no less than five registered patents.
At the heart of the unit is SIM2Â¹s ingenious ALPHA Path light engine, named thus as its shape mirrors that of the Greek symbol Alpha. This proprietary design, developed in-house at SIM2Â¹s Venice research and development facility, maintains the integrity of the optical pathÂ¹s length, which is fundamental to for correct picture aberration control. But by folding the optical path SIM2 has been able to dramatically shrink the projectorÂ¹s size.
Perfect management of this light path, without any kind of scattering or thermal dispersion, is achieved by utilizing a special coating on the inner surface, together with the prisms’ TIR (Total Internal Reflection) control, and optimized relay optics.
Coupled to the innovative light engine are three of the latest HD2+ DarkChip 3 chipsets. These processors, commonly referred to as DC3 chips, incorporate a series of performance enhancing refinements. These include micro mirrors with increased reflectivity, reduced hinge dimensions and smaller gaps between mirrors. ThereÂ¹s also a light absorbent coating on the rear to increase contrast and colour uniformity, along with a flatter, more reflective surface.
The result is a 6500:1 contrast ratio. Equally impressive is the brightness level. The C3X is capable, through its Hi-Brite 250W lamp, of delivering more than 2500 Lumens, which means the C3X is capable of overcoming normal levels of background lighting.
As with all SIM2 projectors the C3X comes with the usual barrage of connections, and of the 10 inputs the HDMI Â HDCP compliant connection tops the list. This means the projector is ready for forthcoming high definition (HD) broadcasts. So as well as being capable of delivering a minimum native resolution of 720 lines in wide aspect ratio the C3X can accept high definition content via component analogue or HDMI Â HDCP digital inputs, and accept both 1280×720 pixels 50/60Hz progressive (720p) and 1920×1080 50/60Hz interlaced/progressive (1080i and 1080p).