What is LED? LED Types and Features

What is LED? Light Emitting Diode, also known as LED semiconductor technology, can be defined as a kind of diode that emits light as the name suggests. It is essentially an electronic circuit element.

Invented in Russia in the 1920s and made applicable in the USA in 1962, this component emerged when a radio technician named Oleg Vladimirovich Losev noticed that the diodes used in radio receivers emitted light and published his discoveries about LED in a Russian newspaper in 1927.

LEDs, which initially emitted only a weak red light, have now emerged as infrared (IR) and ultraviolet (UV), which emit light at frequencies invisible to the eye, as well as visible light. A good understanding of the light emission mechanism of LEDs requires knowledge in quantum physics, chemistry, electronics and optics.

The most important component part of the LED is the LED chip, which consists of semiconductor material and emits light. The LED chip is essentially a point light source, and the light is emitted in a certain direction thanks to the reflective element placed in the sheath. This orientation can also be achieved with the help of lenses or reflectors used in luminaires.

The light emitted by LEDs is related to the structure of the semiconductor additives contained in the LED chips. The light colour emitted by an LED depends on the appropriate ratio of chemical materials such as gallium, arsenide, aluminium, phosphate, indium, nitrite, etc. to the semiconductor.

Basic Information About Lighting

Space Angle

It is the name given to a conical or pyramid-shaped piece of space through which a certain luminous flux passes. The value of the space angle seeing the 1m² plane is defined as 1 steradian.

Light Distribution Curve

It is also called polar photometry. It is the geometric location of the endpoints of the light intensities of the source in various directions on the plane passing through a point light source.

Luminaire Efficiency

It is the ratio of the luminous flux from the luminaire to the flux of the light source in the armature. It is expressed by η.

Upper Half Space Luminous Flux Ratio

The ratio of the luminous flux emitted from the light source in a luminaire into the upper half space to the flux of the source. (ULOR)

Lower Half Space Luminous Flux Ratio

The ratio of the luminous flux emitted from the light source in a luminaire into the lower half space to the flux of the source. (ULOR

Degree of Protection

Indicates the resistance of lighting fixtures against dust, moisture, water and solid objects. It is shown as IPX1X2 according to international acceptance. X1 indicates protection against solid objects while X2 indicates the degree of protection against water. TS3033

Luminaire with Screen

They are luminaires whose maximum luminous intensity is limited to 60* with vertical and do not emit light to the upper half space (ULOR=0).

Semi-screen Luminaire

Luminaires whose maximum luminous intensity is limited to 75* vertically and do not emit more than 10% luminous flux into the upper half space (ULOR<=10%).

Screenless Luminaire

The maximum luminous intensity is not limited to a specific angle, but at an angle of 90* to the vertical

Basic Elements of Lighting

Lighting is defined as light applications designed to make an environment and the objects in it suitable for visual perception in the desired criteria.

Lighting technique is the technique that determines how the lighting should be arranged by taking into account all variables in order to see and exhibit the intended objects and environments in the best way.

Lighting technique makes use of a wide range of scientific data and information ranging from the light and colour vision characteristics of the human eye, various properties of light sources, lamps and lighting devices, light reflection and transmission properties of surfaces and materials, aesthetic and architectural concepts, various measurement techniques, quite complex calculation forms.

As a result of the correct lighting being calculated by expert hands and designed in accordance with the technique, work and traffic accidents, defective production and incorrect
The realities such as reducing diagnoses; eliminating unnecessary fatigue, headaches, eye pains and nervousness; and making daily life more pleasant, more efficient and healthier have already been understood in advanced countries and professional studies have been concentrated. Here, even if the issues affecting the general economy, such as increasing production and success rates and reducing various losses, are left aside and the issue is examined directly in terms of reducing the energy used for lighting purposes, the wide application of the lighting technique