The two-minute guide to Remote Light Source projection21 July 2010
Separating the light source from the noise and heat-producing parts of a projection system can empower architectural environments. Neil Wittering, of Norway’s projectiondesign, explains how it works.
What is Remote Light Source (RLS) projection?
This is a projector but not as we know it or traditionally understand it. Its design comprises the projector’s lamp in a rack-mounted enclosure and transmitting the light to the projector via a Liquid Light Guide (LLG) “cable”. With the RLS installed alongside sources and switching equipment, the heat and fan noise can be controlled separate to the projection location. Access to the rack simplifies lamp maintenance, making lamp changes quick and simple, speeding maintenance and reducing system downtime. The LLG connects to a very compact projector head that incorporates optics and signal processing electronics. The result is a completely silent projector installed in the space with the users, with all noise, heat and handled in the equipment rack.
Why is it interesting?
Projection in the architectural field has had some recent innovations which empowers architects to be innovative and to do much more than traditional projection in boardrooms. The impetus for this move is based on the following factors:
- Presentation of information in an engaging and exciting way for the audience
- Has a lot o ‘wow factor’ – beyond what can be done using a flat panel
- Can be used on interactive surfaces
- Image and light on walls and screens in any shape or size and not limited to a flat rectangular display
- Opens other areas (including integration with building management systems and the audience RFID )
- No “dead space” (as opposed to flat panels when not in use)
- Provides display to completely silent areas
- Applications and installations where reduction of noise and heat is a factor
- Applications that demand unobtrusive hardware using small-format projectors and architectural screen materials.
How does it solve the traditional challenges in projection?
The very nature of projection introduces certain challenges for applications. The first is the fact that projectors use high performance lamps to achieve the brightness required for a given image size. These lamps operate at high temperatures and thus require cooling systems in the projectors to extract the heat. Cooling via fans creates audible noise which projector manufacturers strive to reduce to acceptable levels. Even with today’s super-quiet performance levels, there are applications that demand complete silence from projection equipment.
The second challenge with projection is lamp life and of course lamp replacement. While advances in green LED technology have entered the projection market and are removing the need to replace lamps, the brightness levels from LED projectors is not yet sufficient to satisfy many applications. Typical projector lamp life is between 2,000- 3,000 hours and replacing lamps requires contact with the projector. This contact may create issues with some installations where alignment between projectors is a significant factor, such as tiled multi-projector configurations in display walls, control rooms and simulators.
Lamp replacement can cause projector movement and thus require a re-alignment exercise to maintain image integrity, or changing lamps in projectors that are installed in sensitive locations or difficult to access locations such as museums and entertainment venues where access to the projector is restricted by opening hours.
Removing the lamp from the projector provides added installation flexibility since the limitations on projector orientation imposed by the orientation of the lamp within the projector are removed. This increases the range of options for multi-channel displays such as simulators and other complex installations. It can free architects and designers to devise installations that place projectors at almost any location for creative installations beyond traditional video and computer display and with any screen orientation from flat to angled and curved surfaces.
How visually obtrusive is it?
The “projection head” in a Remote Light Source configuration can be very small and unobtrusive. By removing the primary source of heat from the projector, the need for dedicated cooling is removed which means that the “projector head” can be easily enclosed or concealed if needed.
How crucial is its positioning?
Installation possibilities are limitless installation and it is up up to the creativity and imagination of the architect. They are free to devise installations with single- or multi-projector configurations with no limitations on projector orientation/angle and with no restriction on screen size or shape with screen materials available for almost any shape.
How easy is it to hide away?
Projectors used with Remote Light Source technology will be very compact and lightweight, making them easy to “hide”. When used in conjunction with retractable screens, these installations can almost disappear when not in use. Contrast this with large format flat panel displays which loom at the end of the room when not in use.
Neil Wittering is strategic business manager at projectiondesign in Norway