ProSpex LED

A wide range of Lucent Lighting's product range is now available with LED technology. Here we define this technology, to specify please see the product ranges on the left hand side:

What is an LED?

A Light Emitting Diode or LED is a semiconductor diode that emits light when an electric current is applied in the forward direction of the device. It does this when it recombines with electron holes* within the device which releases energy in the form of photons of light. LED’s do not require heating of a filament to create light, the electricity is passed through a chemical compound which generates the light. An LED often has optics added directly on top of the chip in order to shape its radiation pattern and the reflection of the light.

*A hole is an area where there is an absence of an electron creating a positive charge.

LED colours defined

The colour of an LED is determined by the chemical composition of the semiconductor materials. The colour tone is defined by the dominant wavelength, many colours are naturally available including red, amber, yellow, green and blue. White colours are created with the use of phosphors, a phosphor compound is placed on top of a blue LED.

Colour Rendering

CRI or colour rendering index is an imperfect but widely used quantitative method for measuring the ability of a light source to reproduce the colours of various objects faithfully in comparison with an ideal or natural light source. For example, if a light source has a CRI of 100 it would be a perfect representation of the colours as if they are being viewed under natural daylight. Typical warm white LED have a CRI of Ra 70 – Ra 90 and cols white LEDs typically have CRI’s of 70 and 80.

Beam Distribution and Optics

Secondary optical elements used in addition to the LED’s primary optic to shape the LED’s light output in either single or cluster form.

Binning

The binning process is necessary due to the fact the colour of the white light produced by LEDs varies greatly from warm yellow white to a very cool blue white and in the marketplace colour consistancy is a critcal factor. Binning is essentially sorting the LEDs by colour and brightness in to bins, each bin contains LEDs in a specific colour and brightness or luminous flux.

Lifetime

Unlike other light sources LEDs do not burn out, they dim over time. A typical LED unit is said to have a lifetime of around 50,000 hours for up to 70% brightness.

Advantages of using LEDs

*The use of LEDs offer the following advantages:
* Saturated colours without the need to use filters
* Directional light, an external reflector is not always required however is used in most cases.
* They are insensitive to vibrations and shocks
* Extremely durable
* Very long life
* Very efficient
* They do not emit Ultra Violet
* They do not emit Infra-Red
* They light up instantly
* Good colour rendering
* Limited environmental impact.
* Low maintenance