Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
281 words
In a multi-channel stereo reproducing apparatus for reproducing a recording medium on which if a left front signal is taken as L F , a right front signal is taken as R F , a center front signal is taken as F and a rear signal is taken as B, these signals are encoded to left and right composite signals L T and R T respectively expressed as L T = L F + + and R T = R F + - , the high frequency component of said rear signal B is pre-emphasized and then they are recorded, said multi-channel stereo reproducing apparatus being characterized in that there are provided a matrix circuit for producing said left composite signal L T , said right composite signal R T , a sum signal L T + R T of said left composite signal L T and said right composite signal R T and a difference signal L T - R T of said left composite signal L T and said right composite signal R Tr a reproducing circuit for reproducing said left composite signal L T , said right composite signal R T and said sum signal L T + R T and a reproducing circuit for reproducing said difference signal L T - R T through a delay circuit and a de-emphasis circuit, wherein there is provided means for by-passing said de-emphasis circuit when reproducing a recording medium on which a 2-channel stereo signal formed of only said left and right front signals L F and R F is recorded in which the center front signal F and the rear signal B are not encoded at all is recorded.
Claim 2
Dependent Claim
281 words
In a multi-channel stereo reproducing apparatus for reproducing a recording medium on which if a left front signal is taken as L F , a right front signal is taken as R F , a center front signal is taken as F and a rear signal is taken as B, these signals are encoded to left and right composite signals L T and R T respectively expressed as L T = L F + + and R T = R F + - , the high frequency component of said rear signal B is pre-emphasized and then they are recorded, said multi-channel stereo reproducing apparatus being characterized in that there are provided a matrix circuit for producing said left composite signal L T , said right composite signal R T , a sum signal L T + R T of said left composite signal L T and said right composite signal R T and a difference signal L T - R T of said left composite signal L T and said right composite signal R Tr a reproducing circuit for reproducing said left composite signal L T , said right composite signal R T and said sum signal L T + R T and a reproducing circuit for reproducing said difference signal L T - R T through a delay circuit and a de-emphasis circuit, wherein there is provided means for by-passing said de-emphasis circuit when reproducing a recording medium on which a 2-channel stereo signal formed of only said left and right front signals L F and R F is recorded in which the center front signal F and the rear signal B are not encoded at all is recorded.
Claim 3
Dependent Claim
61 words
A multi-channel stereo reproducing apparatus according to claim 1, wherein said by-pass means is formed of a change-over switch having a pair of fixed contacts and a movable contact, said pair of fixed contacts being respectively connected to the input and output sides of said de-emphasis circuit, and said movable contact being connected to the output side of said reproducing circuit.
Claim 4
Dependent Claim
45 words
A multi-channel stereo reproducing apparatus according to claim 2, wherein said de-emphasis circuit is given a frequency characteristic in which a signal level of a high frequency is emphasized in response to a signal level of said difference signal L T - R T .
Claim 5
Dependent Claim
41 words
A multi-channel stereo reproducing apparatus according to claim 3, wherein said frequency characteristic is such one that when the signal level is about 30 dB, a signal level of a signal higher than about 4 kHz is emphasized by 5 dB.
Claim 6
Dependent Claim
36 words
A multi-channel stereo reproducing apparatus according to claim 1, wherein said delay circuit for delaying said difference signal L T - RT is formed of a digital circuit having an A/D converter and a D/A converter.