Overview SSL Technologies

Solid State Light Sources (SSL) are light producing systems made up of either LED devices or Laser Diodes, producing light output levels from under 50 to over 50,000 Lumen. The four most important technologies, LED, laser phosphor, RB laser and RGB laser, are described below.

Light generated with SSL systems inherently have a longer and more stable brightness level that decreases at a much slower rate than conventional lamp based systems. The SSL technology offers the highest image quality while its operating life span far exceeds traditional lighting methods. Under ‘Why SSL’ you can find many more benefits listed.


Optical Architecture of a LED Light Source

An LED projector uses red, green and blue LEDs as a light source. The pioneering solid state projectorbased on this technology was first commercialized about 7 to 8 years ago, but due to it`s limited light output is only useful in specialty and niche markets.

  • Small design – ideal for portable projectors
  • Vivid colours
  • Brightness limitation of currently 1,000 ANSI Lumen

Optical Architecture of a Laser Phosphor Light Source

Laser-illuminated projectors use arrays of laser sources illuminating a micro-display engine. In the most common Laser Phosphor approach, a blue laser is used for creating the blue colour in the final image, but the same blue laser is also used to illuminate a yellow phosphor wheel, which emits the yellow light. This yellow light is then split by a prism or colour wheel into green and red light components.

  • Very good colours and brightness uniformity
  • Acceptable size
  • High brightness

Optical Architecture of RB Laser Light Source

RB laser technology combines the advantages of brilliant colour reproduction with cost efficiency. In RB laser projection a blue laser is used to create the blue colour and a red laser is used to create the red colour in the final image. The green colour is generated by a green phosphor wheel emitting green light. This technique allows very efficient light reproduction by avoiding optical filters resulting in more intense and more natural colours especially in the red colour segment plus a higher brightness output.

  • Brilliant colours and brightness uniformity
  • Higher brightness
  • Lower power consumption
  • High light efficiency
  • Wider colour space

Optical Architecture of a RGB Laser Light Source

RGB laser on the other hand, uses the so-called ‘pure laser’ technology. Here red, green and blue lasers are delivered directly to the image chip. The product of this technique creates a light pipe consisting of absolutely pure light that is split into the three RGB components. The light is emitted in very narrow RGB bands with very distinct spectral frequencies. This technology allows the creation of a large colour space that easily exceeds even that of AdobeRGB or DCI and can already cover the demanding Rec. 2020 colour space.

  • Best colours and brightness uniformity
  • Highest brightness
  • Size
  • Cost

Hybrid Light Source

A Hybrid Projector uses both laser and LEDs in a single platform. NEC is not using this technology because of its limited colour gamut and difficulties in reproducing accurate colours.

Different Types of Laser Beams

NEC only uses beam-expanded laser technology which spreads the light energy over a much larger area than a non-beam-expanded equivalent. This results in a far lower energy density than for example in a typical hand-held laser pointer, and therefore pose the same safety risks as a conventional lamp based projection system.

NEC has developed their laser technology which strictly observes all safety guidelines comes with comprehensive procedures for proper installation, operation, and maintenance of the systems.

  • Non-Beam Expanded
  • Coherent light output
  • High energy density
  • Beam Expanded
  • Expanded light beam
  • Low energy density

LED Light Source

  1. LED Red
  2. LED Green
  3. LED Blue
  4. Prism (cross dichroic)
  5. Light tunnel
  6. Digital Micromirror Device (DMD)
  7. Prism
  8. Projection Lens

Laser Phosphor Light Source

  1. Blue Laser
  2. Dichroic Mirror
  3. Mirror
  4. Phosphor Wheel
  5. Colour Wheel
  6. DLP ® Chip
  7. Prism
  8. Projection Lens

RB Laser Light Source

  1. Red Laser
  2. Blue Laser
  3. Dichroic Mirror
  4. Phosphor Wheel
  5. Digital Micromirror Device (DMD) for Blue
  6. Digital Micromirror Device (DMD) for Green
  7. Digital Micromirror Device (DMD) for Red
  8. Prism
  9. Projection Lens

RGB Laser Light Source

  1. Red Laser
  2. Green Laser
  3. Blue Laser
  4. Despeckler
  5. Optical Fiber
  6. Digital Micromirror Device (DMD) for Red
  7. Digital Micromirror Device (DMD) for Green
  8. Digital Micromirror Device (DMD) for Blue
  9. Prism
  10. Prism (cross dichroic)
  11. Projection Lens