Patent Document ID: 6047301
Application ID: 08653217
Patent Flag: 1

Claim One:
1. A data processing system comprising: a first unit adaptable for wearing by a user, wherein said first unit includes a processor; a second unit physically separate from said first unit, wherein said second unit includes an input or output device; and an optical link for enabling said first unit to communicate with said second unit, wherein said optical link comprises: a first transceiver coupled to said processor; one or more LEDs coupled to said first transceiver; and one or more photodetectors coupled to said input or output device and operable for receiving signals transmitted from said one or more LEDs, wherein said first transceiver and said one or more LEDs are located coextensively with said first unit, and wherein said one or more photodetectors are located coextensively with said second unit, wherein said one or more photodetectors each further comprise a gain control circuit, said gain control circuit comprising: a photodiode; a first amplifier having an input coupled to said photodiode; a peak follower circuit coupled to an output of said first amplifier; and a second amplifier having a first input coupled to an output of said peak follower circuit and a second input coupled to a reference signal, wherein an output of said second amplifier is operable for controlling a gain of said first amplifier.