EP0222386A2
Expired / Lapsed
EP
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Method and apparatus for PCM recording and reproducing audio signal
Assignee: Hitachi Ltd
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Filing: 1986-11-12
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Granted: —
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Expires: 2006-11-12
Abstract
Abstract A PCM audio signal recording and reproducing apparatus samples an audio signal accompanying with a video signal, converts it to a PCM signal, adds an error detection correction data to a predetermined number of PCM data, forms a data frame by those signals, modulates it in accordance with a predetermined modulation system, and records the audio signal together with the video signal or singly on a record medium by using a rotary head type scanner. A digital signal processing circuit having a memory of a predetermined capacity is provided, and the number of digital data to be recorded in one data frame is varied in accordance with a difference between the number of input data of the digital audio signal to the digital signal processing circuit and the number of output data supplied to the record medium for recording. In the recording mode, the PCM audio signal is sectioned into blocks, a data block address signal is added to each block to indicate a relative order to other blocks and complete in one track, certain number of blocks are combined to form a block set for processing signals, and an identification signal completing in the block and an interleave block address signal for indicating a relative order to other blocks are added to each block.
Inventors
- 👤 Takao Arai
- 👤 Masaharu Kobayashi
- 👤 Nobutaka Amada
- 👤 Yasufumi Yumde
- 👤 Hiroaki Takahashi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 04:09
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/02; G11B20/08; H; H04; H04N; H04N5/00; H04N5/76; H04N5/91; H04N5/92; H04N5/928; G11B20/10; G11B20/10527; G11B20/18; G11B20/1806; G11B20/1809; G11B2020/1087
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
157 words
A PCM audio signal recording circuit for converting an input audio signal to a digital signal, distributing encoding said digital signal for an error detection/ correction, distributing and formatting the encoded data, modulating the formatted data and recording the data on a record medium at a field frequency different from an audio signal sampling frequency, comprising: memory means (15) for storing said digital signal; a detection circuit (51) for detecting ratios of said different field frequencies (f ) and said audio signal sampling frequency (f s ) based on input of said digital signal to said memory means and output of the digital signal from said memory means; and a control circuit (19; 52, 53) responsive to the output of said detection circuit for controlling a read rate of said memory means to control the number of samples or the number of data of said digital signal to be recorded in each field on said record medium.
Claim 2
Dependent Claim
157 words
A PCM audio signal recording circuit for converting an input audio signal to a digital signal, distributing encoding said digital signal for an error detection/ correction, distributing and formatting the encoded data, modulating the formatted data and recording the data on a record medium at a field frequency different from an audio signal sampling frequency, comprising: memory means (15) for storing said digital signal; a detection circuit (51) for detecting ratios of said different field frequencies (f ) and said audio signal sampling frequency (f s ) based on input of said digital signal to said memory means and output of the digital signal from said memory means; and a control circuit (19; 52, 53) responsive to the output of said detection circuit for controlling a read rate of said memory means to control the number of samples or the number of data of said digital signal to be recorded in each field on said record medium.
Claim 3
Dependent Claim
75 words
A PCM audio signal recording circuit according to Claim 1 further comprising: memory write address means (17) for writing said digital signal into said memory means; and memory read address means (19) for reading the digital signal from said memory means to record the digital signal on said record medium; said detection circuit detecting said ratio based on a difference between the outputs of said memory write address means and said memory read address means.
Claim 4
Dependent Claim
52 words
A PCM audio signal recording circuit according to Claim 2 wherein said memory write address means and said memory read address means include counters, and said control circuit controls the read rate such that a difference between a write address count and a read address count of said counters is kept constant.
Claim 5
Dependent Claim
49 words
A PCM audio signal recording circuit according to Claim 1 wherein said different field frequency is a video field frequency, and the digital audio signal having the same period as the video signal and sectioned by the field period of the video signal is recorded on said record medium.
Claim 6
Dependent Claim
106 words
A PCM audio signal recording circuit according to Claim 1 wherein said control circuit includes a circuit (15, 17, 19, 52, 53, 21) for selecting one of at least two data fields in accordance with the output of said detection circuit for matching the video field with the audio data field, said data fields including an excess field (N + S samples/field) having a larger number of data in one field and a diminish field (N - a samples/field) having a smaller numebr of data in one field, where N is a standard number of data, and a and β are integers different from each other.
Claim 7
Dependent Claim
50 words
A PCM audio signal recording circuit according to Claim 5 wherein the data field is selected in accordance with the magnitude of the output of said detection circuit relative to a predetermined ratio or a difference between a read address count and a write address count of said memory means.
Claim 8
Dependent Claim
35 words
A PCM audio signal recording circuit according to Claim 5 further comprising means (51, 53, 24) for generating an identification signal of the selected data field and supplying the identification signal to said record medium.
Claim 9
Dependent Claim
63 words
A PCM audio signal recording circuit according to Claim 7 further comprising: a circuit (44) for detecting the identification signal of the data field from said record medium; and a circuit (37, 38, 27, 15, 18, 20, 21, 8-12) for controlling the audio digital signal picked up from said record medium in accordance with the detected identification signal to reproduce the audio signal.
Claim 10
Dependent Claim
70 words
A PCM audio signal recording circuit according to Claim 1 wherein said detection circuit includes means for detecting a difference between the number of input data to said memory means in certain period of the digital signal and the number of output data from said output means, and said control circuit controls the number of output data from said memory means in accordance with the output of said detection means.
Claim 11
Dependent Claim
54 words
A PCM audio signal recording circuit according to Claim 9 wherein said means for detecting the difference detects a difference between a memory address on said memory means of the input digital signal to said memory means and a memory address on said mmeory means of the output digital signal from said memory means.
Claim 12
Dependent Claim
142 words
A PCM audio signal recording and reproducing apparatus for sampling an audio signal (1) accompanying with a video signal, converting it to a PCM signal, adding error detection/correction data (20) to a predetermined number of PCM data, forming a data frame by those signals (15, 23, 24, 25), modulating it by a predetermined modulation system (36), and recording at least the audio signal on a record medium, comprising: a digital signal processing circuit (16, 17, 18, 19, 21, 22) having a memory (15) of a predetermined capacity; and means (52, 53, 19) for changing the number of digital data to be recorded in one data frame in accordance with a difference (51) between the number of input data of the digital audio signal to said digital signal processing circuit and the number of output data supplied to the record medium for recording.
Claim 13
Dependent Claim
142 words
A PCM audio signal recording and reproducing apparatus for sampling an audio signal (1) accompanying with a video signal, converting it to a PCM signal, adding error detection/correction data (20) to a predetermined number of PCM data, forming a data frame by those signals (15, 23, 24, 25), modulating it by a predetermined modulation system (36), and recording at least the audio signal on a record medium, comprising: a digital signal processing circuit (16, 17, 18, 19, 21, 22) having a memory (15) of a predetermined capacity; and means (52, 53, 19) for changing the number of digital data to be recorded in one data frame in accordance with a difference (51) between the number of input data of the digital audio signal to said digital signal processing circuit and the number of output data supplied to the record medium for recording.
Claim 14
Dependent Claim
41 words
A PCM audio signal recording and reproducing apparatus according to Claim 11 further comprising a recording/reproducing rotary head for recording and reproducing the video signals and the digital audio signal at a video field frequency to and from the record medium.
Claim 15
Independent Claim
102 words
A method for recording and reproducing a PCM audio signal by using a rotary head type scanner, comprising the steps of: (a) sectioning the PCM audio signal into blocks; (b) adding to each block a data block address signal for indicating a relative order to other blocks and completing in one track; (c) combining certain number of said blocks to form a block set for processing signals; (d) adding to each block an identification signal completing in the block set and an interleave block address signal indicating a relative order to other blocks to generate a PCM audio signal to be recorded.
Claim 16
Independent Claim
102 words
A method for recording and reproducing a PCM audio signal by using a rotary head type scanner, comprising the steps of: (a) sectioning the PCM audio signal into blocks; (b) adding to each block a data block address signal for indicating a relative order to other blocks and completing in one track; (c) combining certain number of said blocks to form a block set for processing signals; (d) adding to each block an identification signal completing in the block set and an interleave block address signal indicating a relative order to other blocks to generate a PCM audio signal to be recorded.
Claim 17
Dependent Claim
71 words
A method for recording and reproducing a PCM audio signal according to Claim 13 wherein the data block address signals and the identification signals are alternately arranged block by block, a flag at the beginning is used to detect the data block address signal and the identification signal, and the identification signal is determined in accordance with a low order flag of the data block address signal of a front block.
Claim 18
Dependent Claim
47 words
A method for recording and reproducing a PC M audio signal according to Claim 13 wherein the data block address signals and the identification signals are alternately arranged block by block and is determined in accordance with the value of lower bits of the interleave block address.
References Cited (Backward Citations)
No citation records indexed.
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