Photodetectors typically consist of an emitting element and a receiving element. When designing the optical system of the sensor, it is desirable for the light to propagate in a parallel path. However, standard LEDs exhibit radial emission patterns. Therefore, it is necessary to obtain parallel light by placing a collimate lens in the optical path. KODENSHI have developed collimated light LEDs with high parallel light characteristics by optimization of lens design.

When designing the optical system of the sensor, it is desirable for light to propagate in a parallel path. Figure 1 shows a comparison of the parallel light characteristics between the conventional and developed models. In the conventional model, the light beam spreads as the distance increases, while in the developed model, the beam divergence can be reduced.

In addition, KODENSHI have developed various types of collimated light LEDs, including the HL222 with a glass lens that provides high-precision parallel light characteristics and the JL903, which allows for reflow mounting with heat-resistant resin lenses.

Collimated light LED lineup for optical sensors such as, optical encoders. The lineup includes various wavelengths and shapes.