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

1. A light-emitting knob mechanism to be disposed on a circuit board which is covered by an upper housing, the upper housing having a first opening in spatial communication with the external environment, said light-emitting knob mechanism comprising:

an encoder to be disposed on the circuit board, and including a rotary rod, wherein said rotary rod protrudes out of the upper housing through the first opening, and rotatable about an axis thereof relative to the circuit board, rotation of said rotary rod triggering the circuit board to generate a control signal;

a light guide unit including a lower light guide member and an upper light guide ring, wherein said lower light guide member is tightly sleeved on said encoder, protrudes out of the upper housing through the first opening, and has 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 to 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;

a knob engaged to said rotary rod that protrudes from said second opening of said lower light guide member, and operable to rotate said rotary rod so as to trigger the circuit board to generate the control signal; and

a light emitting unit to be secured to the circuit board, and including alight emitting elements 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.

2. The light-emitting knob mechanism of claim 1 , wherein said encoder further includes a securing seat to be secured to the circuit board, said rotary rod being rotatably disposed on said securing seat, said lower light guide member including a base, said base defining a receiving space, said receiving space having a lower receiving opening, and an upper receiving opening in spatial communication with said second opening, wherein said securing seat of said encoder extends through said lower receiving opening and is received in said receiving space so that said lower light guide member is tightly sleeved on said encoder.

3. The light-emitting knob mechanism of claim 2 , wherein said base of said lower light guide member has a first base surface defining said receiving space, a second base surface located on an outer side of said first base surface, and a connecting surface connecting said first base surface and said second base surface, said first base surface having a first reflecting surface portion, said second base surface having a second reflecting surface portion, wherein said first reflecting surface portion and said second reflecting surface portion are surface-polished so that light propagates through internal reflections in said base between said first reflection surface portion and said second reflection surface portion.

4. The light-emitting knob mechanism of claim 3 , wherein said lower light guide member further includes a plurality of first surrounding plates and a plurality of second surrounding plates extending from said base at an outer periphery of said upper receiving opening along the axis in a direction away from the circuit board, said first and second surrounding plates being spacedly and alternately arranged to surround said second opening, said lower light guide member further including a first stop plate disposed on outerplate surfaces of said first and second surrounding plates, said first stop plate extending in radial directions away from the axis, said first surrounding plates, said second surrounding plates, said first stopping plate and said second base surface cooperatively defining a first engaging groove for engaging the upper housing.

5. The light-emitting knob mechanism of claim 4 , wherein said lower light guide member further includes a plurality of second stop plates respectively disposed on said outer plate surfaces of said first surrounding plates, and a plurality of positioning plates respectively disposed on said outer plate surfaces of said second surrounding plates, said second stop plates and said positioning plates extending in radial directions away from the axis and being further away from said base than said first stop plates, said light incident surface of said upper light guide ring being formed with a plurality of positioning grooves for tightly and respectively engaging said positioning plates therein, said first surrounding plates, said second surrounding plates, said first stop plate, said second stop plates and said positioning plates cooperatively defining a second engaging groove for engaging said upper light guide ring to thereby allow said upper light guide ring to be securely sleeved on said lower light guide member.

6. The light-emitting knob mechanism of claim 5 , wherein the light emitted by said light emitting element of said light emitting unit is reflected by said first and second base surfaces of said lower light guide member, out through said first and second surrounding plates of said lower light guide member, and then incident upon said light incident surface of said upper light guide ring.

7. The light-emitting knob mechanism of claim 6 , wherein said light emitting element of said light emitting unit is a light emitting diode (LED).

8. 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.

9. The audio system of claim 8 , wherein said light emitting element of said light emitting unit is a light emitting diode (LED).