Center mode control circuit

Claim 2

A center mode control circuit for switching of a normal mode for adding low frequency component of a center input signal to left and right stereo input signals, a phantom mode for adding full range of said center input signal to said left and right stereo input signals, and a wide mode for not adding said center input signal to said left and right stereo input signals, comprising: means (31) for amplifying said center input signal, switching means (34) connected to an input terminal of said amplifying means, and capacitor means (35, 36) selected by said switching means and having different characteristics from each other, said mode switching being performed by controlling of said switching means.

Claim 3

A center mode control circuit according to claim 1, wherein said amplifying means (31) comprising positive and negative input terminals and an output terminal, and said switching means (34) connected to the positive input terminal of said amplifying means, for switching a state of said positive input terminal to be open, to be connected to the high pass capacitor (35) or connected to the full pass capacitor (36).

Claim 4

A center mode control circuit according to claim 1, wherein said center mode control circuit is formed in a single integrated circuit, and said switching means being connected to an external pin of said integrated circuit.

Claim 5

A center mode control circuit comprising: a first signal path for a left stereo input signal, a second signal path for a center signal, a third signal path for a right stereo input signal, a high pass inversion amplifier means (31) inserted into said second signal path, a first adder means (29) for adding an input signal and an output signal of said high pass inversion amplifier means to said left stereo input signal applied to said first signal path, a second adder means (30) for adding the input signal and the output signal of said high pass inversion amplifier means to said right stereo input signal applied to said third signal path, and switching means (34) for switching so that the output signal of said high pass inversion means becomes any of a high pass signal, a full range signal or a zero signal of said center signal.

Claim 6

A center mode control circuit comprising: a first signal path for a left stereo input signal, a second signal path for a center signal, a third signal path for a right stereo input signal, a high pass inversion amplifier means (31) inserted into said second signal path, a first adder means (29) for adding an input signal and an output signal of said high pass inversion amplifier means to said left stereo input signal applied to said first signal path, a second adder means (30) for adding the input signal and the output signal of said high pass inversion amplifier means to said right stereo input signal applied to said third signal path, and switching means (34) for switching so that the output signal of said high pass inversion means becomes any of a high pass signal, a full range signal or a zero signal of said center signal.

Claim 7

A center mode control circuit according to claim 4, wherein said center mode control circuit is formed in a single integrated circuit, and said switching means being connected to an external pin of said integrated circuit.