What Is an Edge Sensor?
An edge sensor is a device that measures the position, gap, and width of the edge of an object by illuminating the object with light or other means.
They can accurately measure not only equipment parts but also transparent objects such as films, sheets, and glass. When the object to be measured is large, multiple edge sensors are used.
Uses of Edge Sensors
Edge sensors mainly have two applications: edge surface measurement and gap or width measurement. In edge surface measurement, light is shone over a fixed area including the edge of the object. Measurement is made by detecting the distance between the edge of the object and the optical axis within the measurement range. In gap and width measurements, light is shone onto the object to measure its width or gap. It can be used to check for deformation in the external shape of parts or equipment, or to check the diameter of a hole punched by a press.
Principle of Edge Sensors
Edge sensors use the physical principle of light. They consist of a light source, a light source lens, a light-receiving lens, and a light-receiving element. Light from the light source lens is projected onto the object, and the projected light is received by the light-receiving element. When light strikes the object, the position of the light entering the light-receiving element changes. By measuring the amount of this change, it is possible to measure edges, etc.