24 March 2017

Osram launches 810nm IR LED to increase image contrast in license plate recognition

Osram Opto Semiconductors GmbH of Regensburg, Germany is expanding its Oslon product family of high-power infrared LEDs for illumination solutions to include a new wavelength (810nm), benefiting camera systems such as those used to read license plates.

With the SFH 4703AS, the additional wavelength can be used to improve image contrast, making it easier to read patterns from recorded images. Moreover, camera sensors have higher sensitivity at 810nm. At the same optical output, the new device therefore extends the range of camera systems compared with 850nm.

Greater image contrast for easier analysis

The newly available wavelength is particularly advantageous for applications requiring superior image contrast. Wavelengths of 850nm and 940nm typically used currently have difficulty creating high-contrast images of certain color combinations.

For example, for camera systems supporting automatic license plate recognition at toll stations or entrances to parking garages, the SFH 4703AS yields higher-contrast images for many types of license plates, making it easier to retrieve the license plate numbers. As a result, automated barriers function more smoothly, reducing waiting times for drivers. Other camera applications also stand to benefit from the new component, such as traffic monitoring and closed-circuit television (CCTV) systems.

Increased range – same optical output

The new wavelength comes with the added bonus that the spectral sensitivity of typical camera sensors is higher at 810nm than it is for 850nm and 940nm. Using a light source with the same optical output, an 810nm system will achieve a greater detection distance than was previously possible. Alternatively, this also allows designers to reduce the number of components if they wish to maintain the same range. However, Osram says that designers should bear in mind that humans do perceive infrared light as a mild red glow, and this is stronger at 810nm than at 850nm.

High optical performance – proven package

Osram Opto currently provides 810nm emitters for iris scanners in mobile devices. For the SFH 4703AS, developers mounted the highly efficient chip manufactured in nanostack technology in the tried-and-tested Oslon package for illumination applications. At 1A current, the emitter generates 1W optical power. The beam angle of +-45° allows for broad illumination, with a resulting radiant intensity of 630mW/sr at 1A. The component measures 3.85mm by 3.85mm, and is 2.29mm high including the lens.

The firm says that, with the new device, designers can now choose from mutually compatible emitters in three different wavelengths. These can be combined within a single illumination unit or used to convert existing systems to another spectral range without the need for layout changes.

See related items:

Osram launches its first 810nm IR LED, targeting iris-based biometric unlocking

Tags: Osram IR LED

Visit: www.osram-os.com