Epson's E-TORL puts projectors in a new green light

The Epson Twin Optimized Reflection Lamp (E-TORL) is probably the projector industry’s most significant innovation in lamp design since the arrival of the modern multimedia projector. Pioneered by Epson in 2005 and found in almost every Epson projector today, the E-TORL is a projector lamp that features an elliptically-shaped reflector with an additional sub reflector unit to achieve an unprecedented 20% improvement in light projection efficiency. This results in lower power consumption, cooler operation and longer operational life compared to conventional projector lamps.

A projector lamp is basically composed of a burner element and a reflector. Conventional projector lamps feature a semi-circular, parabolic reflector shape that does not efficiently reflect light generated from the lamp’s burner element toward the projector’s optical system. This is because the curvature of the conventional lamp’s reflector allows a significant portion of the light to be reflected away from the light path of the optical unit, where it is lost as heat. If a projector’s light source loses too much light through such inefficiency, the picture it produces will appear dim. With the goal of radically improving the efficiency of a projector’s lamp, the Epson visual instrument research team developed a completely new design for the projector lamp system, resulting in the E-TORL.

In the E-TORL, the parabolic reflector has been replaced with an elliptically shaped one that reflects light beams to the optical system far more efficiently. In addition, Epson engineers added a sub-reflector unit to the E-TORL, which further improves efficiency by collecting and channeling the light from the area in centre of the lamp into the optics.

The E-TORL’s innovative new design is smaller than a standard lamp, yet it runs cooler, more efficiently, and brighter. The reduced size allows Epson to shrink the projector’s optical engine, resulting in an overall reduction in the projector’s size.

Elliptically shaped reflector.The lamp and the sub-reflector unit.Brilliant Results

The E-TORL design allows almost 100% of the light from the lamp to be collected and channeled through to the projector’s optical system. This gives the E-TORL an overall improvement in efficiency of 20% when compared to a conventional lamp, helping users to save on power costs. In practical terms, this higher efficiency means that an E-TORL can provide an output of 170 watts, versus 136 watts from an ordinary lamp with the same input.

The E-TORL runs cooler than a standard lamp of similar wattage because the design incorporates an air gap between the reflector and the burner. This cooler operation also enables further benefits: 1) this means that the cooling fan of the projector does not need to spin as fast, further reducing power consumption.