JPH03205674A - Digital data recording and reproducing device - Google Patents

Abstract

PURPOSE:To automatically and consecutively record an absolute time and a program number by providing a 2nd means for generating a new absolute time and a new program number and a 3rd means for recording the absolute time and the program number generated by the 2nd means on a recording medium. CONSTITUTION:At the time of finishing the reproducing or the input of data, a CPU circuit 5(the 2nd means) sets an ID code circuit 4 in a recording mode during a period T3 following a period T2 and increments the program number based on the reproduced or inputted data. During a period T4 after the period T3 ends, a mechanical control CPU circuit 6 outputs a recording start signal to a PCM circuit 2, and the circuit 2(the 3rd means) receives the recording start signal and records the data such as the absolute time and the program number on a magnetic tape 1. Thus, the absolute time and the program number are automatically and consecutively recorded in the case of superposable recording or consecutive recording.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a digital data recording and reproducing apparatus, and particularly to a digital data recording and reproducing apparatus that is most suitable for a digital audio tape recorder and a PCM audio VTR.

[Prior Art] Conventionally, digital audio tape recorders have been known that are capable of recording absolute time, which indicates absolute time from the top of the tape, on a magnetic tape. When using such a digital audio tape recorder to record a previously recorded magnetic tape, it is possible to record at absolute time without erasing the last part of the previously recorded part and ensuring time continuity. is added to the magnetic tape.

Also known are digital audio tape recorders that record absolute time, start ID, and program number on magnetic tape during recording. Such digital audio tape recorders automatically record the absolute time and program number on the magnetic tape in the following cases.

In other words, when recording from the beginning of winding a magnetic tape or when reading and displaying an already recorded absolute time, the absolute time can be determined, and the absolute time is automatically recorded following the already recorded section. It is recorded on magnetic tape. Similarly, when recording from the beginning of magnetic tape winding or when loading and displaying a program number that has already been recorded, the program number can be determined, so the program number is automatically added to the already recorded section. are recorded on magnetic tape.

With such conventional digital audio tape recorders, when continuing to record on a magnetic tape that has already been recorded, the end of the already recorded magnetic tape is played back to read the absolute time and program number. Unless they are recorded on magnetic tape later, the absolute time and program numbers will not be recorded continuously.

[Problems to be Solved by the Invention] However, in order to read the absolute time and program number by reproducing the end portion of a magnetic tape that has already been recorded, it is necessary to switch from recording mode to playback mode, which requires a lot of operation. There is a problem that it becomes complicated.

The present invention has been made in view of the above-mentioned problems, and allows absolute time and program numbers to be automatically recorded continuously in one table without requiring any special manual operation when overlapping or splicing recording. The purpose is to

[Means for Solving the Problems] In order to achieve this object, the digital data recording/reproducing device of the present invention is provided such that the absolute time indicating the absolute time from the starting point of the recording medium and the program number corresponding to each program are at least equal to each other. The included ID code and
In a digital data recording and reproducing device that records and reproduces predetermined digital data on a recording medium, there is a possibility that the recording medium has already been recorded after a command is given to record digital data on the recording medium and before recording on the recording medium is started. A first means for reading out the recorded absolute time and program number; and a second means for generating a new absolute time and program number following the absolute time and program number read by the first means. and third means for recording the absolute time and program number generated by the second means on a recording medium.

[Function] In the digital data recording/reproducing device having the above configuration, special manual operations are not required by reading data during the time required to start recording, that is, the time required for playback for splicing recording, etc. Absolute time and program numbers are automatically recorded continuously even when over-recording or splicing.

[Example] Hereinafter, an example of the present invention will be described based on the drawings. In the embodiment, a case will be described in which the present invention is applied to a PCM audio VTR.

In VTRs, it is used to continue previously recorded track patterns, track channels, etc., even when recording on top of an already recorded magnetic tape or when splicing. Since the end portion of the magnetic tape that has already been recorded is played back, approximately 2 seconds are required from when the recording button is pressed and the magnetic tape begins to move until recording actually begins. Therefore, in the present invention, the absolute time and program number included in the ID code recorded with the PCM audio data are read from the magnetic tape during that approximately 2 seconds, so that the data can be spliced and recorded with the already recorded data. There is.

FIG. 2(a) schematically represents a track pattern on a magnetic tape in an embodiment of the digital data recording/reproducing apparatus according to the present invention.

In a PCM audio VTR, PCM audio data and ID codes are recorded on tracks of a magnetic tape 1, as shown in FIG. 2(a). Each track (field) is divided into five blocks, and each block constitutes one sub-frame. One subframe is further divided into 30 blocks with addresses O to 29, as shown in FIG. 2(b).

FIG. 3 shows a format for recording an ID code in each block.

As shown in Figure 3, among the data at addresses ○ to 29, "1, 9, 17, 25", "3, 11, 19"
, 27", "5, 13, 21, 29", "7, 15,
23'' addresses are used as optional codes (8 bits each).

Data can be recorded in these optional codes as shown in FIGS. 4 and 5.

In FIG. 4(a), a 4-pit item (ITEM) and a program number 1 (PNO-1) are recorded at addresses 1 and 17, respectively. Similarly, addresses 3 and 19 contain program number 2.
(PNO-2) and program number 3 (PNO-3)
are recorded in 4 bits each, and an index number (8 bits) is recorded in addresses 5 and 21.

The item (4 pits) is ACI when it is "0100"
This indicates that AC4 to AC4 are the program number and index number. Program number 1,
Program number 2 and program number 3 represent a three-digit decimal program number.

Note that the blank area in FIG. 4(a) is an unused area.

These addresses 1. 3. 5. 7 (17,
19.21.23) data ACI
AC4 to AC4 are configured.

Further, as shown in FIG. 5, a program number (8 bits) is recorded at addresses 9 and 25, and an index number (4 bits) and a program start flag P S F (1 bit) are recorded at addresses 11 and 27. ) are recorded. The program number here represents the program number in binary. Also, the index number (4 bits) represents the index number in binary, and the program start flag P S
F (1 bit) is set to "1" for 300 frames at the start of the program so that the start of the program can be identified.

Furthermore, the lower 3 bits of addresses 11 and 27 represent the "time" of the absolute time in binary, and the upper 2 bits of addresses 13 and 29 again represent the lower 2 bits of the "time" of the absolute time in binary. There is. Similarly, the lower 6 pits of addresses 13 and 29 represent the "minute" of the absolute time in binary, and the upper 2 bits of address 15 again represent the lower 2 bits of the "minute" of the absolute time in binary. .

These addresses 9, 11, 13.15 (25.27.
29) constitutes data SCI to SC4.

Each data of ACI to AC4 and SCI to SC4 is combined and recorded at least once in each field.

FIG. 4(b) shows a format for recording absolute time as an ID code in an embodiment of the digital data recording/reproducing apparatus according to the present invention.

As shown in FIG. 4(b), a 4-bit item (ITEM) and an absolute time (H O U R ') are recorded at addresses 1 and 17, respectively. In addition, the absolute time minute (MINUTE) is recorded in 8 bits at addresses 3 and 19.
At addresses 5 and 21, 8 pits of absolute time seconds (SECOND) are recorded. Furthermore, in the 8 bits of addresses 7 and 23, the upper 2
Data representing the mode is set in the bits, and a frame number (FRAME) representing the frame position in the absolute time is recorded in the following six pits.

When the item (4 bits) is "0001", it indicates that the optional code is absolute time. For absolute time, HOUR (4 bits) represents "hour", MINUTE (8 bits) represents "minute" as a 2-digit decimal number, and SECO
ND (8 bits) represents a 2-digit decimal "second", and FRAME (6 bits) represents a 2-digit decimal frame number.

Furthermore, when the second bit of the upper two bits of addresses 7 and 23 is 1, it indicates DROP FRAME MODE, and that frame is not counted as a frame at that absolute time. This bit is O
, the frame is counted as a frame at that absolute time. This corrects the discrepancy between the number of frames and the absolute time.

The lower 6 bits of addresses 7 and 23 represent the "frame number" as a two-digit decimal number.

Each of the data ACI to AC4 in FIG. 4(b) is also combined with the data SC1 to SC4 in FIG. 5 and recorded at least once in each field.

Next, the recording operation of the digital data recording/reproducing apparatus according to the present invention will be explained with reference to FIGS. 1 and 6 to 9.

As shown in FIG. 6, when a record button (not shown) is pressed at time t1 and an instruction is given to the mechanical control CPU circuit 6 shown in FIG. 5 is notified that the recording button has been pressed, and the drive of the magnetic tape 1 is started (9th
(See step S10 in the figure).

During a period T2 from time t1, the audio data circuit 3 of the PCM circuit 2 (see FIG. 1) is set to the recording mode by the CPU circuit 5. At this time, the audio input to be recorded is output as is. Also, at this time, PCM
The ID code circuit 4 (first means) of the circuit 2 is set to a reproduction mode and reads ID code data from the reproduction signal of the magnetic tape 1. As a result, the voice output system is so-called E
The absolute time and program number are reproduced and input from the magnetic tape 1 while the E (electrical-electrical) system remains in place.

Set the audio data circuit 3 to recording mode and set the ID code circuit 4
By setting the to the playback mode, it appears to be in the recording mode (see steps S11 and S12 in FIG. 9).
.

When the data reproduction and input are completed, the CPU circuit 5 (second means) performs the following operations during the period T3 following the period T2.
While setting the ID code circuit 4 to recording mode,
The program number is incremented from the reproduced and input data. Further, the control pulse reproduced from the control track of the magnetic tape 1 for each field is detected to count the absolute time. In this way, preparations for recording are made (
FIG. 7 and FIG. 9 Step S13 to Step S16
reference).

When the period T3 ends (when the recording start point arrives), during the subsequent period T4, the mechanical control CPU circuit 6 outputs the recording start signal (REC START).
) is output to the PCM circuit 2, and upon receiving the recording start signal, the PCM circuit 2 (third means) records absolute time and program number data on the magnetic table l (step S17 in FIGS. 8 and 9). (See step Si9).

The above operations are performed not only when overlapping recording onto the magnetic tape 1 that has already been recorded, but also when performing continuous recording in which recording, recording pause, and recording operations are repeated. In other words, when moving from recording to recording pause operation,
When moving from a recording pause to a recording operation by taking a pack space of 2 seconds from the recording end point, recording is started 2 seconds after the magnetic tape 1 starts moving.

Although the present invention has been described above using examples, various modifications are possible according to the technical idea of the present invention. For example, it is possible to provide an editing function that allows the user to specify the recording start point and recording end point using absolute time.

In addition, the ■D code of PCM, t-dio vTR includes T
Since there is data called oC (Table Of Contents), this TOC data can also be read and recorded.

Furthermore, in the connection using zero frame editing and in the above-mentioned embodiment, the absolute time is counted by control pulses from data input to recording (see Figure 9). It is also possible to count by drum FF {g number corresponding to the rotational phase of . Further, instead of counting until recording, the CPU circuit 5 of the PCM circuit 2 may permit recording after counting to a certain extent. However, it is necessary to prevent image dropouts from occurring during continuous recording.

According to the embodiment described above, the following effects can be obtained.

Since it can be realized using microcomputer software, it is inexpensive.

Further, even immediately after inserting a tape cassette, no operation is required to read data.

Furthermore, even if the tape position shifts due to repeated tape loading and unloading, the data recording position does not shift.

[Effects of the Invention] As explained above, according to the digital data recording and reproducing apparatus of the present invention, the absolute data that has already been recorded is Since the time and program number can be read out, the absolute time and program number can be automatically recorded continuously even when overlapping or splicing recording without requiring special manual operations.

[Brief explanation of drawings]

1, 7 and 8 are block diagrams showing the configuration of an embodiment of a digital data recording/reproducing apparatus according to the present invention,
FIG. 2(a) is a diagram illustrating the pattern of recording tracks on a magnetic tape in an embodiment of the digital data recording/reproducing apparatus according to the present invention, and FIG. 2(b) is a diagram illustrating the configuration of one subframe. FIG. 3 is a diagram illustrating a format for recording a code in an embodiment of the digital data recording/reproducing device according to the present invention; FIG. 4(a),
(b) is a diagram explaining the format for recording the program number or absolute time in the format of Figure 3, and Figure 5 is a diagram explaining the format for recording the program number and absolute time in the format of Figure 3. Diagram to explain, No. 6
The figure is a front view of a magnetic tape for explaining the operation of an embodiment of the digital data recording/reproducing apparatus according to the present invention, and FIG.
8 is a flowchart illustrating the operation of the embodiment shown in FIGS. 1, 7, and 8. FIG. 1... Magnetic tape, 2... PCM circuit, 3... Audio data circuit, 4' ID code circuit, 5... CP+
1 circuit, 6...mechanical control CPU circuit. Figure 4 (a) Figure 2 (b) Figure 3

Claims (1)

[Scope of Claims] An ID code that includes at least an absolute time indicating an absolute time from a starting point of the recording medium and a program number corresponding to each program, and predetermined digital data are recorded and reproduced on the recording medium. In the digital data recording and reproducing device, the absolute time already recorded on the recording medium and the absolute time between when recording of the digital data on the recording medium is instructed and when recording on the recording medium is started. a first means for reading the program number; a second means for generating a new absolute time and program number that are continuous to the absolute time and program number read by the first means; 2. A digital data recording and reproducing apparatus comprising: third means for recording the absolute time and program number generated by the second means on the recording medium.