Patent ID: 6798402
Filing Date: 2004-09-28
Classification: G06F

Abstract:
A received-light pattern detection apparatus for detecting a received-light pattern representing the position of an object existing in front of a monitor, comprising:a plurality of light-receiving modules arranged around the periphery of the monitor while being connected in a cascade manner; a plurality of light-emitting modules arranged around the periphery of the monitor so as to face the light receiving modules, wherein each of the light emitting modules comprises a plurality of light-emitting elements; each of the light-receiving modules comprises a plurality of light-receiving elements, a latch circuit for latching a plurality of outputs generated by said light-receiving elements, a timing control circuit which makes the latch circuit to latch the outputs of the light-receiving elements one by one, and a shift register which transmits the latched outputs in a serial signal form after all outputs of said light-receiving elements are latched; each of the light-receiving elements included in said light-receiving modules forms a photo-coupler with a light-emitting element included in said light-emitting module; and said shift register is connected in a cascade manner with a shift register which is included in an adjacent arranged light-receiving module and transmits serial signal transmitted from a shift register of a former stage; said received-light pattern detection apparatus further comprises an input/output interface which instructs said plurality of light-receiving modules at the same time to start latching said outputs and receives the serial signal transmitted from a shift register of the latest stage.