Sensing object irregularities may affect operation (BGS and FGS).Irrespective of the high-end, modern-age photography gear you own, nothing beats the charm of an analog film camera. The effects of background objects are minimized (BGS). The effects of sensing object color are minimized (BGS and FGS). Small differences in height can be detected (BGS and FGS). In that case, an OFF delay timer or some other means may need to be employed to prevent chattering. Reflected light may return to the Receiver momentarily for item (3) due to sensing object movement. (3) Uneven, glossy surfaces that reflect a lot of light but disperse the light in random directions. (2) Objects like mirrors that return virtually all light back to the Emitter. Objects that reflect less than a specified amount of light are as follows: (1) Objects with extremely low reflectance and objects that are darker than black paper. The FGS function prevents objects closer than the set distance or objects that reflect less than a specified amount of light to the Receiver from being detected. The BGS function prevents any background object (i.e., the conveyor) beyond the set distance from being detected.

When using the E3Z-LS61, E3Z-LS66, E3Z-LS81, or E3Z-LS86, select the BGS or FGS function to detect objects on a conveyor belt. The Sensor calculates the difference between the light intensity at the N end and F end to determine the position of the sensing object.īGS (Background Suppression) and FGS (Foreground Suppression) Conversely, the reflected light is concentrated at the F end when the sensing object is located farther than the preset distance. If the sensing object is closer to the Sensor, then the reflected light is concentrated at the N end. When a sensing object reaches the preset position, the reflected light is concentrated midway between the N end and the F end and the photodiodes at both ends receive an equal amount of light. The end of the photodiode nearest the case is called the N (near) end and the other end is called the F (far) end. The following figure shows a detection system that uses a 2-part photodiode. Sensing is based on the principle of triangulation, which states that where the beam is concentrated depends on the distance to the sensing object. The light reflected from the sensing object is concentrated on the Receiver. The Receiver in the Sensor is either a 2-part photodiode or a position detector. Positioning the beam on an object is simple with models that emit visible light because the beam is visible. This property can be used to detect colors. The rate at which an object reflects or absorbs light depends on both the wavelength of the emitted light and the color of the object. There is little chance of damaging sensing objects or Sensors because objects can be detected without physical contact. These developments enable detecting very small objects, as well as precise position detection. The incredibly high resolution achieved with these Sensors derives from advanced design technologies that yielded a very small spot beam and a unique optical system for receiving light. The response time is extremely fast because light travels at high speed and the Sensor performs no mechanical operations because all circuits are comprised of electronic components.

This means they can be used to detect virtually any object, including glass, plastic, wood, and liquid. These Sensors operate on the principle that an object interrupts or reflects light, so they are not limited like Proximity Sensors to detecting metal objects. This is impossible with magnetic, ultrasonic, or other sensing methods.Ģ.

A Through-beam Sensor, for example, can detect objects more than 10 m away.

Photo reflector