LED knowledge: How many types of LEDs can be divided into

LED stands for light-emitting diode, which is essentially a semiconductor device that emits light when an electric current passes through it. Depending on their properties and applications, these diodes can be categorized into several types:

Firstly, based on the light-emitting color of the diode, we have a variety of options including red, orange, green (which can be further subdivided into yellow-green, standard green, and pure green), blue, and white LEDs. Additionally, some LEDs combine two or even three different colors within a single chip.

Furthermore, LEDs of each color category can also be grouped by their physical properties, such as whether they are transparent or diffused, and whether they are tinted or clear. Diffused LEDs are commonly used as indicator lights due to their ability to scatter light evenly.

In terms of display technology, red, green, and blue LEDs are frequently employed due to their vibrant hues and ability to create a wide range of colors. For lighting purposes, however, white LEDs are far more prevalent because of their versatility and energy efficiency.

Secondly, depending on the light-emitting surface characteristics of the diode, we can classify them as round, square, rectangular, surface-mount, side-emitting, or micro-surface mount types. Round LEDs come in various diameters, such as φ2mm, φ4.4mm, φ5mm, φ8mm, φ10mm, and φ20mm. In international standards, φ3mm LEDs are often called T-1, φ5mm as T-1 (3/4), and φ4.4mm as T-1 (1/4).

The angular distribution of light intensity varies among these types. High directivity LEDs, with half-angle values of 5° to 20° or less, are ideal for focused illumination or detecting systems. Standard types, with half-angle values of 20° to 45°, serve as excellent indicators. Scattered types, with half-angle values exceeding 45°, offer broad viewing angles, making them suitable for applications where visibility is crucial.

Thirdly, LEDs differ structurally too. They can be epoxy-sealed fully, mounted on a metal base with epoxy, placed on a ceramic base with epoxy, or housed in a glass casing. Each design offers unique advantages depending on durability, heat dissipation, and application needs.

Lastly, LEDs can be categorized by their luminous intensity and operating current. Ordinary LEDs emit light intensity up to 100mcd and typically operate at currents between 10mA and tens of milliamps. High-intensity LEDs produce light intensity ranging from 10mcd to 100mcd. Low-current LEDs, with an operating current below 2mA, maintain similar brightness levels as standard LEDs but consume less power.

In summary, LEDs are incredibly versatile devices that cater to numerous applications across industries. Their adaptability in terms of color, shape, structure, and performance makes them indispensable in modern electronics and lighting solutions.