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    VIDEO SIGNAL RECORDING APPARATUS
    35.
    发明专利
    VIDEO SIGNAL RECORDING APPARATUS 未知

    公开(公告)号：CA2049721C

    公开(公告)日：2001-08-14

    申请号：CA2049721

    申请日：1991-08-22

    Applicant: SONY CORP

    Inventor： SAKAMOTO ETSUROU

    IPC: H04N9/80 ,  H04N9/79 ,  H04N9/81 ,  H04N9/82 ,  H04N9/896 ,  H04N5/91

    Abstract: Video signal recording apparatus wherein a video signal is processed, such as in time division multiplexed format. A burst clock signal of frequency f b is generated for recovering the video signal during a subsequent reproduction operation; and this burst clock signal is added to a DC level portion that is present in the processed video signal, resulting in a combined signal. The combined signal is frequency modulated and recorded on a record medium. Assuming that the DC level of the processed video signal is represented by a modulating frequency f a, if f a ~~f b, then ~2f a - mf b - f b~ ~ 0.15f b; and if f a ~ ~ f b, then ~mf b - 2f a - f b~ ~ 0.15f b.

    36.
    发明专利
    未知

    公开(公告)号：DE69027815T2

    公开(公告)日：1996-12-12

    申请号：DE69027815

    申请日：1990-05-21

    Applicant: SONY CORP

    Inventor： SAKAMOTO ETSUROU

    IPC: H03D3/00 ,  H04N5/911 ,  H04N5/93 ,  H03D3/04 ,  H04N5/91

    Abstract: An FM-demodulating apparatus for use in a video tape recorder or the like arranged such that an FM-modulated video signal is phase-shifted by utilising a Hilbert transform circuit thereby to reduce the occurrence of moire. Thus, a signal-to-noise (S/N) ratio of a demodulated signal can be improved. In one embodiment, the apparatus comprises a first demodulator circuit (13) receiving an FM-modulated input; a Hilbert transform circuit (15) receiving the FM-modulated signal for phase-shifting it by 90 degrees; a second demodulator circuit (16) coupled to said Hilbert transform circuit (15); and mixing means (17) coupled to said first demodulator circuit (13) and said second demodulator circuit (16) for deriving FM-demodulated video signals. In a second embodiment, the apparatus comprises a Hilbert transform circuit (62, 63, 65) receiving the FM-modulated signal for phase-shifting it by 90 degrees, said Hilbert transform circuit including delay circuits (62, 63) and a subtracting circuit (65); adding means (64) coupled to said delay circuits (62, 63) included in said Hilbert transform circuit; a first demodulator circuit (67) coupled to said adding means (64) for demodulating signals obtained from said adding means (64); a second demodulating circuit (69) coupled to said subtracting circuit (65) of the Hilbert transform circuit for demodulating signals obtained from said subtracting circuit (65); and a mixing circuit (70) coupled to said adding means and said subtracting circuit of said Hilbert transform circuit for deriving FM-demodulated video signals.

    38.
    发明专利
    未知

    公开(公告)号：DE69110491D1

    公开(公告)日：1995-07-27

    申请号：DE69110491

    申请日：1991-02-14

    Applicant: SONY CORP

    Inventor： SAKAMOTO ETSUROU

    IPC: H04N5/922 ,  G11B20/06 ,  H03C3/00 ,  H03D3/04 ,  H04N5/931 ,  H04N9/79

    Abstract: The demodulating apparatus (10) suitable for use in a VTR or the like. It has a suppressing circuit (20) for suppressing sideband components of FM modulated waves, a pulse counter type demodulation circuit (30) for demodulating the output from the suppressing circuit (20) and a recovering circuit (40) connected to the output of the FM demodulation circuit (30) for recovering the sideband components suppressed by the suppressing circuit (20), to thereby provide a favorable demodulation. The suppressing (20) and recovering (40) circuits advantageously comprise a sine and a cosine equalizer. The suppression of the sideband components results in lowering the modulation figure thereby reducing fluctuations in amplitude and distortion. Recovering the suppressed sidebands prevents drop-out of information.

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