Pin-point stands for a new type of LED technology for photoelectric switches and photoelectric proximity switches from Sick . Pin-point LEDs concentrate energy on a smaller area and increase the intensity of the light spot.
This results in highly simplified alignment of a photoelectric switch. The longer range or scanning distance, the high functional reserves, and the “miniaturisation” of the light spot on the object expand the applications of photoelectric proximity switches.
While in the case of photoelectric proximity switches, a smaller, more focused light spot is important when small objects have to be detected at high speeds, in the case of photoelectric switches, the potential range or the corresponding functional reserve is important.
In the area of opto-sensors, pin-point represents a similar technological leap as the change of transmission light source from light bulb to LED that took place several years ago. These “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 pin-point LED does not have this bonding wire due to a different constructional design. This makes the light intensity of the light spot homogeneous, and the spot itself more focused, i.e. the halo that usually surrounds the light spot is almost completely eliminated. As a result, the pin-point 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 pin-point 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 to conventional LED transmission light sources. Additionally, if the range specified for the particular sensor is not fully exploited, the resultant functional reserve and the availability of the particular sensor increases, e.g. in the case of contamination of the optics taking place during operation.
A WT2S miniature photoelectric proximity switch incorporating pin-point technology is capable of resulting in a light spot diameter of just 1 mm at a scanning distance of 15 mm while the rugged WTB27-3 photoelectric proximity switch can support a 5 mm diameter at a scanning distance of 500 mm.
These applications, which were earlier realised using laser photoelectric proximity switches can now be realised using pin-point technology, which provides four advantages over the former: laser-related safety regulations need not be applied, the operating temperature range expands upwards and downwards, the service life of the transmission light source is almost doubled, and the purchase price for the photoelectric proximity switch is lower.