Pinpoint photoelectric sensors

Sick has released a range of photoelectric switches and photoelectric proximity switches in which pinpoint LED technology concentrates energy on a smaller area and increases the intensity of the light spot.

Conventional LEDs can be recognised by the black dot in the middle of the light spot. This black dot is created as a result of the bonding wire on the LED, used to provide the electrical contact between the LED and electronic card. The pinpoint LED does not have this bonding wire due to a different construction. This makes the light intensity of the light spot homogeneous and the spot itself more focused — the halo that usually surrounds the light spot is almost completely eliminated. As a result, the pinpoint LED creates a highly intensive, focused and easily visible red light spot that is formed on the target object with precise geometry and thus ensures high detection reliability. The pinpoint light spot considerably simplifies alignment of the sensor during commissioning or re-adjustment. Another advantage is the longer range or scanning distance of the opto-sensors compared with conventional LED transmission light sources.

Pinpoint technology also allows smaller objects to be detected. The WT2S miniature photoelectric proximity switch has a light spot diameter of 1 mm at a scanning distance of 15 mm and the rugged WTB27-3 has a 5 mm diameter spot at a scanning distance of 500 mm. Thus, some applications in which a laser photoelectric proximity switch has previously been used can be solved by devices using pinpoint technology.