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EP0466434A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Waveform equalizing filter unit

Assignee: Sony Corp
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Filing: 1991-07-08
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Granted: —
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Expires: 2011-07-08
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Abstract

Abstract A waveform equalizing filter unit of a simplified circuit configuration for use in a MUSE decoder or the like. The filter unit comprises a waveform equalizing filter with a plurality of taps each having a unitary delay element and a coefficient multiplier; a clock switching circuit for selecting one of clock signals of at least two different frequencies inputted thereto, and outputting the selected clock signal to the unitary delay elements of the waveform equalizing filter; and a control means for selectively switching the tap coefficients of the coefiicient multpliers in the waveform equalizing filter in accordance with the operation of switching the clock signals by the clock switching circuit. A signal timing adjuster is further included in a stage anterior to the waveform equalizing filter so as to adjust the timing to switch the input signal in synchronism with the clock switching operation. In such constitution, optimal signal waveform equalization conforming to each distortion characteristic can be achieved in a simplified circuit configuration by selectively switching both sampling rates and tap coefficients of a single waveform equalizing filter in accordance with the distortion characteristic.

Inventors

  • 👤 Ikuo Someya
  • 👤 Masahiro Komoda

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-05 23:17
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/14; H04N5/21; H04N5/211; H03; H03H; H03H17/00; H03H17/02; H03H17/06; H04L; H04L25/00; H04L25/02; H04L25/03; H04L25/03006; H04L25/03012; H04L25/03114; H04L25/03133; H04L25/0314

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 93 words
A waveform equalizing filter unit comprising: a waveform equalizing filter with a plurality of taps each having a unitary delay element and a coefficient multiplier; a clock switching circuit for selecting one of clock signals of at least two different frequencies inputted thereto, and outputting the selected clock signal to the unitary delay elements of said waveform equalizing filter; and a control means for selectively switching the tap coefficients of the coefficient multipliers in said waveform equalizing filter in accordance with the operation of switching the clock signals by said clock switching circuit.
Claim 2
Dependent Claim 84 words
A waveform equalizing filter unit according to claim 1, wherein said control means calculates the equalization characteristics relative to the clock signals of mutually different frequencies, then compares the calculated characteristics with each other, and enables said clock switching circuit to output therefrom the selected clock signal suited to provide the best equalization characteristic, said control means further capable of calculating the optimal tap coefficients relative to the selected clock signal and setting the same in the coefficient multipliers of said waveform equalizing filter.
Claim 3
Dependent Claim 45 words
A waveform equalizing filter unit according to claim 1 or 2, further including, in a stage anterior to said waveform equalizing filter, a signal timing adjuster for adjusting the timing to switch the input signal to be equalized, in synchronism with the clock switching operation.
Claim 4
Dependent Claim 59 words
A waveform equalizing filter unit according to any of claims 1 through 3, wherein said clock switching circuit is provided for each of the unitary delay elements of said waveform equalizing filter in a manner to switch the clock signal for the individual unitary delay elements, and said control means sets the corresponding tap coefficients in said coefficient multipliers.
Claim 5
Dependent Claim 17 words
A signal decoder including a waveform equalizing filter unit according to any one of the preceding claims.
Claim 6
Dependent Claim 11 words
An HDTV system including a decoder in accordance with claim 5.

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