Method and device of proximity sensing

• Main Authors: WANG, LIN-XUAN, ZHU, YU-LUN
• Format: Patent
• Language: Chinese; English
• Published: 16.04.2014
• Subjects: ANALOGOUS ARRANGEMENTS USING OTHER WAVES; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION ORRERADIATION OF RADIO WAVES; MEASURING; PHYSICS; RADIO DIRECTION-FINDING; RADIO NAVIGATION; TESTING

A method of proximity sensing presets a first light emitting element and a light sensor which next to each other, and a second light emitting element which spaced from the light sensor for a predetermined distance. When the first light emitting element emits a first light signal, the light sensor senses a first reflect light signal of the first light signal, and when the method determines the strength of the first reflect light signal bigger than a first threshold, it determines an object is near, and continually determines if the strength of the first reflect light signal still bigger than a second threshold, if not, the second light emitting element emits a second light signal, and the light sensor senses a second reflect light signal of the second light signal, and the method determines if a ratio of the strength of the first reflect light signal and the strength of the second reflect light signal bigger than a third threshold, if yes, it determines an object is near.