Patent attributes
A method for determining a location of IR-cut filter film on a substrate, the filter film and the substrate cooperatively functioning as an IR-cut filter, includes the steps of: providing an infrared laser device, an IR-cut filter and an infrared laser sensor; emitting a laser from the IR laser device to a surface of the IR-cut filter in a manner such that the laser beam is obliquely incident on an edge portion of the IR-cut filter; and determining the location of the filter film on the substrate of the IR-cut filter in such a way that, if the intensity of the laser beam received by the infrared sensor is equal to or close to zero, the location of the filter film is on a surface of the substrate facing towards the infrared laser device; if the intensity of the laser beam received by the infrared sensor is the same as or close to an intensity of the laser beam emitted from the infrared laser device, the location of the filter film is on a surface of the substrate facing away from the infrared sensor.
