Patent US4639681A successfully refreshed from Google Patents.
US4639681A
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Waveform reshaping circuit
Assignee: Pioneer Corp
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Filing: 1985-02-21
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Granted: 1987-01-27
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Expires: 2005-02-21
Abstract
Abstract In a waveform reshaping circuit for a digital signal which has become distorted, the threshold level is varied according to the codes of bits preceding each bit in a bit string forming data in the digital signal so that, even if coding interference takes place, a reshaped, undistorted digital signal outputted by the circuit is substantially the same in waveform as the original digital signal.
Inventors
- 👤 Tsunao Hasegawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:26
CPC Classifications
H; H03; H03K; H03K5/00; H03K5/01; H03K5/08; H03K5/082; H03K5/086; H03K5/088
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
166 words
A waveform reshaping circuit for a distorted digital input signal whose instantaneous level varies according to binary data, comprising: a plurality of comparison means for comparing an instantaneous level of said digital signal with a plurality of reference levels to provide outputs, respectively; and selecting means for selecting one of said outputs as a digital signal which is waveform shaped selectively according to binary data in said digital signal which has been outputted; and wherein said selecting means comprises: a multiplexer having data inputs receiving respective ones of said outputs of said comparison means; and shift register means having a clock input, a data input coupled to an output of said multiplexer, and logic coded clocked outputs coupled to control inputs of said multiplexer, so that said multiplexer selects an instantaneous reference level from said outputs of said plurality of comparison means according to said binary data in said distorted digital input signal, whereby a reshaped undistorted digital output is provided in synchronism with said clock.
Claim 2
Dependent Claim
166 words
A waveform reshaping circuit for a distorted digital input signal whose instantaneous level varies according to binary data, comprising: a plurality of comparison means for comparing an instantaneous level of said digital signal with a plurality of reference levels to provide outputs, respectively; and selecting means for selecting one of said outputs as a digital signal which is waveform shaped selectively according to binary data in said digital signal which has been outputted; and wherein said selecting means comprises: a multiplexer having data inputs receiving respective ones of said outputs of said comparison means; and shift register means having a clock input, a data input coupled to an output of said multiplexer, and logic coded clocked outputs coupled to control inputs of said multiplexer, so that said multiplexer selects an instantaneous reference level from said outputs of said plurality of comparison means according to said binary data in said distorted digital input signal, whereby a reshaped undistorted digital output is provided in synchronism with said clock.
Claim 3
Dependent Claim
16 words
The waveform reshaping circuit of claim 1, wherein said shift register means comprises a single flip-flop.
Claim 4
Dependent Claim
15 words
The waveform reshaping circuit of claim 1, wherein said shift register means comprises two flip-flops.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-01-26 | 1990-07-28 | 1991-01-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-01-26 | 1994-07-28 | 1995-01-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-01-26 | 1998-07-28 | 1999-01-27 | $7700.00 | Window Closed / Lapsed |