23 Jul 2024


Bright sensor LED rivals laser beams

Sick has introduced a high-intensity LED-based optical sensor technology which delivers a brightness and accuracy that, it claims, rival those of short-range laser scanners. It adds that the Pin-Point LED system will significantly widen the range and performance of LED-based photoelectric and proximity switches.

The new LED design – first previewed at the SPS/IPC/Drives show in Germany in late 2008 – boosts light spot intensity and concentrates its energy on a much smaller area. It is also said to offer greater functional reserves, improved detection reliability and the ability to operate over longer ranges.

Using Pin-Point LEDs, photoelectric switches can detect much smaller objects – down to 1mm – over distances of up to 500mm, providing an effective alternative to laser diode photoelectric switches, without the safety precautions needed for lasers. It also has a wider temperature operating range and, with a typical lifetime of 100,000 hours, lasts twice as long as laser diodes, offering significant purchase and operating cost savings.

The improved performance has been achieved by redesigning the LEDs to eliminate the bonding wire at the tip, which normally results in a distinctive central black spot in the emitted light and a halo of lower-intensity light. The Pin-Point spot has almost no halo and its homogenous intensity allows a much tighter and precise focus.

Alignment is said to be simpler and the tighter spot ensures a longer range. The highly concentrated light can help overcome contamination and dirt which can build up during use.

“The Pin-Point is an amazing development in the world of opto-sensors,” says Sick’s UK sensor specialist, Phil Dyas. “It represents a similar technological leap to the change of transmission light source from light bulb to LED.

“Pin-Point LED design takes the photoelectric and proximity sensor into a precision detection role,” he adds. “It also gives us scope for reducing the number of sensors needed for an application, increasing the potential applications for LED sources.”