Light-emitting knob mechanism and an audio system incorporating the same

An audio system comprising:

• an audio host device including a lower housing, a central control unit disposed inside said lower housing, and an audio output unit electrically connected to said central control unit;
• and
• an panel mounted to said lower housing of said audio host device, and including a circuit board that is electrically connected to said central control unit, an upper housing that is engaged with said lower housing for enclosing said circuit board, an encoder that is disposed on said circuit board, a light guide unit, a knob, and a light emitting unit secured to said circuit board;
• wherein said upper housing has a first opening in spatial communication with the external environment, said encoder including a rotary rod that protrudes out of said upper housing through said first opening, and that is rotatable about an axis thereof relative to said circuit board, rotation of said rotary rod triggers said circuit board to generate a control signal for subsequent transmission to said central control unit;
• wherein said light guide unit includes a lower light guide member and an upper light guide ring, said lower light guide member being tightly sleeved on said encoder, protruding out of said upper housing through said first opening, and having a second opening and at least one optical channel, said rotary rod of said encoder protruding out of said lower light guide member through said second opening, said upper light guide ring having a third opening, a light incident surface connected with said at least optical channel, and a light transmitting surface spaced apart from said light incident surface, said upper light guide ring being sleeved on said lower light guide member through said third opening;
• wherein said knob is engaged to said rotary rod that protrudes from said second opening, and is operable to rotate said rotary rod so as to trigger said circuit board to generate the control signal;
• wherein said light emitting unit includes a light emitting element disposed adjacent to said encoder and capable of emitting light, wherein the light emitted from said light emitting element of said light emitting unit irradiates said lower light guide member, propagates through said at least one optical channel of said lower light guide member, and is incident upon said light incident surface of said upper light guide ring, and is then transmitted out from said light transmitting surface in radial directions away from the axis.