JPS6342083A - Program monitoring device in digital tape recorder - Google Patents

Abstract

PURPOSE:To save useless time and labor in a search action by always monitoring whether results that an inputted program number is compared with its previous number contradict a tape travel direction. CONSTITUTION:At the timing of a timing generator circuit 40 an effective program number PNO at that time is transferred to a 1st register 35. Simultaneously contents preserved just before are transferred to a 2nd register 36, and a tape travel direction identification flag DIR based on the tape travel direction is transferred to a comparison control part 37. A comparison part 41 decides whether results that the contents of the 1st register 35 are compared with those of the 2nd register 36 in terms of magnitude contradict decision conditions given from the comparison control part 41. If an alarm flag is outputted to a flag latch circuit 39 from a flag latch circuit 39 at the same timing, it is latched, and the alarm is issued to a display part 16.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a program monitoring device for detecting errors in program management information in a digital tape recorder.

(Conventional technology and its good fortune) Modern times are at a turning point from analog technology to digital technology, and the field of cheap recorders is also developing from the conventional analog type to digital tape recorder (DAT). Many proposals have been made for this digital tape recorder as well.

Figure 3 shows tape track 7 of a helical scan DAT.
Indicates an automatic display.

The tape T is wound diagonally around a rotating head drum, and a recording pattern of diagonal tracks is formed alternately by two magnetic heads arranged 180 degrees apart (90'' winding) around the outer periphery of the rotating head drum. A indicates the tape running direction, and arrow B indicates the head moving direction.

The 7 ohmat of each tape track is 1 as shown in the figure.
The PCM data area PCM is divided into 6 areas, where audio data etc. are recorded as PCM, and the subcode formed before and after the PCM data area PCM, which records the song number, address information, time code, and other information related to the program. Area 5
It mainly consists of UB1, 5UB2, and an auto-tracking finding area ATF in which an auto-tracking frequency signal for accurately tracking the magnetic head with respect to the tape track is recorded. After the PCM data area PCM1 sub-food area 5UBI and 5UB2, there is a space PO9T to prevent data in other areas from being destroyed due to tape misalignment when performing post-recording etc. and partially recording on the tape track.
AMBLEs are formed respectively, and interblock gaps 7'IBG are formed at four locations to prevent interference between areas on the tape track.

When searching for a program recorded on a tape according to the tape 7 format configured as described above, subcode information recorded on the track is used.

'This subcode information includes the track number (program number), address, and address of each program recorded on the tape.
This management information includes performance time, time from the tape start point, and various flags (described later) for searching each program.

These subcode information can be recorded at multiple locations on the tape track 7 format shown in FIG. 3, and the PCM-ID is recorded as an ID code in the PCM area PCM.

It is possible to use 5UB-ID recorded as an ID code in the subcode areas 5UBI and 5UB2, and 5UB-DATA recorded as data in the subcode area. However, the subcode information recorded in the subcode area is the PCM-I recorded in the PCMfi area.
Since 5UB-DATA has the same contents recorded as data in PACK format for the same items as 5UB-ID, there is no possibility of discrepancy between the contents of both. There will be no contradiction.

Also, on the tape is a TOC (T a
ble of contents) may be formed. The TOC has a special machining 7 at the beginning of the tape, and PACK is added to the subcode l[5UB1゜5UB2.
If recorded in format, subfood area 5UBI, 5U
When recording in PACK format on B2 over the entire tape, a TOC area is provided at the beginning of the tape and the PCM-I
When Auxiliary Code is written in D, Auxiliary C is written in PCM-ID.
Four formats have been proposed for recording over the entire tape using ode, and when these formats overlap, priority is given to the description type.

However, the TOC (
(hereinafter referred to as U-TOC) is difficult to rewrite, so general users can do post-recording or partial! In practice, the TOC that can be changed when the i collection is performed will be the U-TOC.

Therefore, in digital tape refugue, any program on the tape can be searched at extremely high speed based on the above-mentioned subcode information and TOC information.

When actually searching, the search method is as follows:
Search between songs by program number and program time, cue by specifying program number, search by program number and index, high-speed search by TOC and absolute time from tape start point, START-I
There are many possible combinations and applications, such as a search using D.

Subcode information closely related to each of the above-mentioned searches will be explained below.

Figures 4(,) to (d) show tracks 7 ohm/
This is a step-by-step decomposition of the

Figure 4(a) shows the 7-ohm format of one entire track.
This itself corresponds to one track in FIG.

FIG. 5B shows the contents of the sub-food area 5UBI. Furthermore, the subcode area for one track is 5UBI,
Although it exists in 21MI of 5UB2, the format is the same, so 5UBI will be explained.

Subcode fuIa S U B 1 is a block synchronization function that clarifies the delimiter for converting serial input data into parallel symbols and also indicates the block boundary to recover bit synchronization even if bit synchronization is lost due to books etc. ID signal 5YNC, subcode information
Word W1.5UB-CODE ID and 5UB- corresponding to 5UB-CODE ID recorded as a signal
5UB-CODE which records the address of each of the 8 blocks that make up CODE ID, the word W2 that forms BLOCK ADDRESS v4, the parity given by the exclusive OR of Wl and W2, and the P1 subfood information that is recorded as data in PACK format. It consists of DATA.

FIG. 6(c) further shows the contents of the words W 1 and W 2 broken down. Each word consists of 8 bits, word W1 is 5UB-CODE ID
, word W2 is 5UB-CODE ID 4 bits and B
LOCK ADDRESS consists of 4 pins F.

Figure (d) shows a more detailed breakdown of the contents of the 5UB-CODE ID in figure (e). Both 5UBI and 5UB2 are composed of 810 links, and the 5UB-CODE ID is composed of a set of 2 blocks. In other words, considering a set of 2 blocks, one block has 5 UB-CODE IDIJtCO
NTROL-ID, DATA-ID, FORMAT
-ID and in the other block PNO-
ID (2), PNO-ID (3), PNO-ID (1)
are assigned to each.

C0NTR0L-ID is 5U as shown in FIG.
Both B1.5 and UB2 are recorded with the same contents, and each bit is a TOC-ID.

5HORTENING-ID, START-ID, PR
It is assigned to four flags of IORITY-ID.

TOC-ID (hereinafter referred to as T-ID) is l) 1 when the program is registered in the TOC, O when it is not registered, START-ID, (hereinafter referred to as 5-ID)
is a flag that becomes 1 at the start point of each program and becomes O in the middle of the program. PRIORITY-ID (hereinafter referred to as P-ID) is a program number PNO to eliminate contradictions in subcodes that occur when performing partial dubbing etc. As described later, if it is 1 where 5-ID stands, it indicates the program number P at that time.
This flag indicates that N○ is valid, and O indicates that it is invalid. 5HORTENING-ID: When 1 is placed at the beginning of the omitted part on the tape, it indicates the next START-I.
This flag is set to 5KIPL up to D, and is set to 0 where it is not set.

Now, returning to Figure 4(d), DATA-ID is 5U.
This is to give the format of B-DATA (for example, D
When the content of ATA-ID is 0000'', 5UB-D
All ATA is recorded in PACK format. )be.

FORMAT-ID gives the number of PACKs used in 5UB-DATA, and PNO-ID (
2), PNO-ID (3), and PNO-ID (1) indicate program numbers recorded on the tape. In PN○-■D, each of (1) to (3) represents one digit in binary coded decimal, and the total can represent a three-digit numerical value.

The above is the main structure of the subfood information, and next, these flags S-ID, P-ID, and T-ID.

Program management using subcode information such as PNO-ID will be described.

Note that P-ID can only record 1" where there is 5-ID, meaning that the PNO-ID of that program is valid, and T-ID can be recorded only where there is 5-ID. At least the 5-ID portion is set to be '1'.

The PIS6 diagram shows four types of programs using these flags and seven patterns CASE A-CASED.

CASE A is P-ID, T- where there is 5-ID.
When both IDs are 0'', the program specified by 5-ID is the PNO in the program area.
becomes invalid, indicating that this program does not exist in the TOC either.

In CASE B, P-ID is “1” where 5-ID is located.
", T-ID is O", which indicates that the program defined by this 5-ID has a valid PNO at the location where the 5-id exists.

However, this program does not exist in the TOC.

In CASE C, P-ID is 0″ where there is 5-ID.
, T-ID is 1'', indicating that the program defined by this 5-ID has an invalid PNO in the program area.

However, this program exists in the TOC.

CASE D is P-ID, T- where 5-ID is.
In the case where both the ID is "1", the program defined by this 5-ID has a valid PNO at the location where the 5-ID exists, and also exists in the TOC.

In digital tape recorders, the above four CAs
SEs are defined, and program management is to be operated based on these CASEs.

In this way, in a digital tape recorder,
High-quality recording and playback using PCM recording and high-speed search using subcode information (100% to normal recording and playback speed)
Another major difference from conventional digital audio equipment such as compact discs is that general users can perform recording/editing.

In other words, it is sufficient to use a mini-knock tape that has already been recorded, but if the user records or edits the program contents, the information related to the program, that is, the subcode information, must also be managed reliably at the same time. There is a high possibility that a contradiction will occur in operations such as partial re-recording or partial re-recording.
If there is an ID), the IDs may be duplicated, decreased, or the order may be random.

In the type of 7-bit disc that uses the main TOC (U-TOC), the user must return to the beginning of the tape and rewrite the U-TOC every time the user records or edits.

Also, program management pattern is first CASEA-CAS.
As shown in E D, CASE C.

The advanced management method using TOC like CASE D will not necessarily be adopted in all sets, especially in consumer equipment.

CA that does not use TOC, which is expected to be widely adopted in one shell
In the case of SE A and CASE B, if a search is performed on a tape with the above-mentioned inconsistency, various problems will occur.

For example, assume that a program with a PNO of 3 is currently being played. Now, if you want to search for a program with a PNO of 5, you will naturally search towards the end of the tape (but if the program with a PNO of 5 physically precedes the program with a PNO of 3) , the end of the tape is searched, and then the beginning of the tape is searched again for one step. Therefore, no matter how fast the search is performed, it takes time to find the desired program. Unable to take advantage of certain high-speed searches.

Furthermore, if the PNO you are trying to search for is gone, it is possible that the search will continue without being able to find the program, and if there are multiple PNOs, an accurate search may become impossible. Become.

(Purpose of the Invention) The purpose of the invention is to solve the above-mentioned problem, when a discrepancy occurs in the subcode information that provides the program management information by performing Awarefu 9 editing etc. in a digital tape recorder. An object of the present invention is to provide a digital tape recorder that detects this and issues a warning.

(Summary of the Invention) In the subcode information serving as program management information, a 5-ID flag indicating the start point of the program and a P for determining whether the program number CPNO) is valid or invalid.
- Read the program number at the timing when the ID flag is set simultaneously, and compare the program number with the program number read immediately before (both in terms of size) and the program read from the tape running direction. A program for a new digital tape recorder that is configured to display a warning flag to indicate that there is an error in program management information if there is a discrepancy between the results of determining whether the order is ascending or descending. It is a monitoring device.

(Embodiment) FIG. 2 is a block diagram for explaining the principle of the digital tape recorder of the present invention.

1 is the tape drive mechanism, 2 is the magnetic head h,,h
2 is a rotating head drum with 180° separation (90° wrapping) on the outer circumference, 3 is a capstan, 4 a, 4 b
is the reel axis. Further, reference numerals 5 at 5 b are movable idle posts that pull out the tape from the attached cassette (not shown) and load it onto the rotary head drum 2 or unload it on the rotary head drum 2. A drum drive system 6 that drives the rotating head drum, a capstan drive system 7 that drives the capstan 3, and a reel shaft 4, respectively.
A loading drive system 9 is disposed that drives the loading mechanisms such as a ripple drive system 8 and guide bosses 5a and 5b according to the operation mode.

The drum drive system 6, capstan drive system 7, and reel shaft drive system 8 are connected to a control block 11 via a mechanism control interface 10, and according to commands from the control block 11, the tape drive mechanism is set to a predetermined position. It is meant to be controlled. And loading drive! 'P, 9 are also connected to the control block 11 via the loading control interface 12, and are controlled by this.

The control block 11 also includes a sensor input interface 7 ace 13 for inputting data from various sensors (not shown) for detecting the start and end of the tape, detecting dew condensation, etc.
, a key input interface 7Ace 15 for supplying data to the operation keys 14, a display output ink 7Ace 17 for outputting data to a display g16 that displays various displays depending on the operation mode, and a signal processing system to be described later. Subcode interface 1 for exchanging subcode information with
8. PNO to the program monitoring circuit 34 of the present invention, which will be described later.
, P-ID, 5-ID, DIR (indicating the tape running direction, which will be described in detail later), and the like are connected to interfaces 19 for supplying necessary information, respectively.

The signal processing system will now be explained.

The magnetic head bllh2 is connected to a recording/reproduction switching block 20 that selectively switches between a recording system and a reproduction system.

To explain the recording system, an analog signal input from the recording input terminal IN is adjusted to a predetermined level by a level control circuit 21, sampled by a sample hold circuit 22, and supplied to an A/D conversion circuit 23 to be converted into a digital signal. signal (PCM signal). Furthermore, the PCM signal is subjected to interleaving, addition of an error correction code, modulation, etc. by the signal processing system 25 in the signal processing block 24, and then sent to the magnetic herad h3. h2 and recorded on tape.

To explain the playback system, it's a magnetic head! The PCM signal reproduced from 1□l+2 is supplied to the reproduction head amplifier 27 by the recording/reproduction switching block 20, and then the equalizer,
After being waveform-shaped by a waveform shaping circuit 28 consisting of a comparator or the like, the signal is supplied to the signal processing block 24.

Then, it is read out by the PLL circuit 29 in the signal processing program 24 in synchronization with the clock signal extracted from the digital signal, and demodulated by the signal processing system 25. At this time, error detection, error correction, error correction, deinterleaving, etc. are performed simultaneously, and the signal is then supplied to the D/A conversion circuit 30 and converted into PAM (Pulse Amplitude).
Modulation) signal. Furthermore, this PAM signal is outputted to the reproduction output terminal OUT via the low-pass filter 31 and the level control circuit M32.

Also, a reproduction system and signal processing system 25, a rotating head drum 2.
Capstan 3. From the reel pongee 4a, 4b, the ATF signal on the tape track, servo FG, PG signals, etc. in each drive system are always supplied to the drive servo system 33 that servos the drum, capstan, reel pongee, etc.
This servo system 33 performs various controls such as rotation control of the 7-drum, automatic tracking, and capstan rotation control.

34 is a program monitoring circuit which is the main part of the present invention, and the information in the subcode information on the tape tracker is P-I.
Errors in program management information on the tape are detected from flags such as D, S-ID, PNO and Vf-7' running direction identification signal DIR.

FIG. 1 is a block diagram showing the configuration of the program monitoring circuit 34. As shown in FIG.

In the figure, 35 is a first register to which the program number PNo (PNO-ID) in the subfood information taken out from the control block 11 via the interface 19 is transferred, and 36 is a register in which the PNO-ID is transferred to the first register.
This is the second register to which the content that was in the first register immediately before is transferred.

Reference numeral 37 denotes a comparison control unit that transfers information as to whether the tape running direction is in ascending or descending order of the program number PNO to the comparison unit 38 as a judgment condition.
It is determined from the tape running direction obtained through 0 that the reproduction or search is being performed in the 7-word direction or in the reverse direction. In other words, if there is no contradiction between the program recorded on the tape and its management information, if the tape is running in the 7-word direction (it is sufficient that the tape is running in both playback mode and search mode). The basis for this is that the program numbers are arranged in ascending order, and if the tape is running in the reverse direction, the program numbers should be arranged in descending order.

Reference numeral 38 denotes a comparison unit that compares the results of comparing the magnitude relationship between the contents of the ml register 35 and the second register 36 with the judgment condition from the comparison control unit 37, and sets a warning flag if there is a discrepancy between the two. It is.

Reference numeral 39 is a flag latch circuit that, when a warning flag is output from the comparator 38, latches it and holds that state until it is reset, and displays a warning on the display 16.

40 receives the flags P-ID and 5-ID in the subcode information through the interface 19, and inputs the flags P-ID and 5-ID in the subcode information.
ID is input at the same time (the PNO at that time is valid), the timing generation circuit generates the PNO transfer timing, and at this timing, the valid program number PNO at that time is transferred to the first register 35, and at the same time, the first The contents stored in the register 35 until immediately before are transferred to the second register 36, and the contents stored in the register 35 are transferred to the second register 36, and the contents are transferred to the second register 36.
The tape running direction identification flag DIR based on the tape running direction is transferred to the controller 41 , and the comparison unit 38 compares the magnitude relationship between the contents of the first register 35 and the contents of the second register 36 . A comparison is made to see if there is a contradiction between the judgment conditions determined by .

Furthermore, if a warning flag is output from the comparator 38 to the flag latch circuit 39 at the same timing (actually delayed slightly), this is latched and a warning is displayed on the display 16.

41 takes out the cassette and it's number 8! The first register 35, second register 36, comparison control section 37, comparison section 38, flag latch circuit 39, and display section 16 are activated by turning on the power and operating a reset button (not shown). This is a reset circuit that resets everything to the cut state.

The program monitoring circuit 34 is configured as described above, and its operation will be explained below.

The program monitoring circuit of the present invention detects inconsistencies in the program management information from the PNO, P-ID, and 5-ID in the subcode information recorded on the tape and the tape running direction identification flag. . Therefore, as long as the tape is running, it can be used in playback mode or high-speed search mode (there is no effect depending on the operating mode).

For example, when performing a high-speed search operation, when a program search is instructed using the operation key 14, the operation key 14
A command is input to the control block 11 via the interface 15 and decoded, and in response to the command, the head drive system 6, capstan drive system 7, reel shaft drive system 8, etc. are set to the fast feed mode ( In reality, it is about 100 to 200 times the normal recording and playback speed).

At this time, the rotational speed of the rotary head drum 2 also changes according to the tape speed, and is controlled so that the recorded information on the tape can be reliably reproduced.

The signals read out from the tape to the magnetic nodes h, h2 are sent to the signal processing block 2 via the waveform shaping circuit 28.
4, and the subcode information on the tape track is supplied to the controller block 11 via the subcode interface 18. The program numbers PNO, P-ID, and S-ID are read out from the control block 11 via the interface 19 and supplied to the program monitoring circuit 34.

5-ID and P-ID are supplied to the timing generation circuit 40, and when 5-ID and P-ID are input at the same time, PN
○Generate transfer timing. The fact that 5-ID and P-ID are input at the same time indicates that the program number PN○ at that time is valid, as explained with reference to fjS6.

When timing is generated by the timing generation circuit 40, the valid PNO at that time is read into the first register 35. At the same timing, the first register 35
The contents previously stored are transferred to the second register 36. These operations are performed by generating timing every time 5-ID and P-ID are input simultaneously.

Further, a tape running direction identification signal DIR indicating whether the search is being conducted in the 7-word direction or in the reverse direction is supplied. In other words, as mentioned above, if there is no conflict between the program on the tape and its program management information, the program numbers PN○ on the tape will be in ascending order if the search direction is in the 7-word direction, and in reverse if the search direction is in the reverse direction. If so, they are each taken into the signal processing block 24 in descending order.

Therefore, the comparison control unit 37 is supplied with the search direction information DIR from the mechanism control interface 10, which determines whether the program number PNO should be loaded into the first register 35 and the second register 36 in ascending order or in descending order. It is supplied to the comparison unit 38 with the determination condition being whether or not it should be used. Note that this operation is performed by the timing generation circuit 40 to transfer the program number PNO to the first register 35 and to
This is performed together with the transfer from the second register 35 to the second register 36.

On the other hand, when the above-mentioned operation is performed, the comparison unit 38 compares the contents of the first register 35 and the second register 36, that is, the magnitude relationship of the program number PNO, and the result is determined based on the determination condition of the comparison control unit 37. It is determined whether there is a contradiction.

If the tape running direction is the 7-word direction, the program numbers PNO are assigned to the signal processing block 24 in ascending order.
It should be incorporated into. Therefore, P-ID and 5
- ID is input at the same time and valid program number P
Every time NO is detected, it is read into the ml register 35, and the contents stored in the first register 35 until then are transferred to the second register 3G. If we compare the contents of the register 36, that is, the size of the valid program number PNo, we always find that the first register 35>the second register 36...
It should read ■.

However, it goes without saying that in the case of transfer due to the first timing occurrence after reset, the program number PNO is not yet stored in the second register 36, so that it is not subject to comparison.

In other words, when the 5-ID and P-ID are captured at the same time for the first time, there is nothing in the first register 35 up to that point, so they cannot be compared.
The first comparison can only be performed when the ID and P-ID are input simultaneously.

If the tape running direction is the reverse direction, the above 7
E. It can be considered exactly the same as the word direction search, but the valid program numbers PN○ to be retrieved are in descending order. Since the tape is being searched in reverse, the program numbers PNO are arranged in descending order unless there is a contradiction.

Therefore, the magnitude relationship between the contents of the first register 35 and the second register 36 is always as follows: second register 36>first register 35...
It should read ■. This determination condition is given from the comparison control section 37 to the comparison 81S38.

In addition, if the tape running direction is reversed, only the first program number PNO is transferred, and the first register 3
5=Second register 36...■. Therefore, for the first comparison after reversing the tape running direction, even if the contents of both registers are the same, the program number management information is not erroneously detected as an error. is set in advance.

Next, a case where a contradiction is discovered between a program and its management information will be explained.

When 5-ID and P-ID are input at the same time, the program number at that time is valid, so the first register 3
The contents of 5 are newly transferred to the register 36 of @2, the program number PNO is newly transferred to the first register 35, and a comparison operation is performed by the comparison section 38 while referring to the tape running direction identification flag DIR of the comparison control section 37. However, if the result is contrary to formulas (1) to (2), the actual position of the program is different from the program management information, and there is a contradiction between the two.

Therefore, even if you continue searching in this state, the management information such as the existence and location of the desired program will be unreliable.
A warning is issued, that is, a warning flag is issued by the comparator 38, latched by the flag latch circuit 39, and then output to the display 16, thereby indicating to the user that there is an error in the program management information on the tape.

In addition, as mentioned above, discrepancies in program management information,
User's 77 Lev, part! Various patterns can be considered, such as the order of valid program numbers being swapped due to i collections, etc., or the same program number existing multiple times, but in any case, a warning will be issued when a contradiction is detected. be able to.

The above is the operation of the program monitoring circuit in the search operation. The warning signal displayed on the display section 16 is saved until it is reset, and after performing a search or playback, etc., the program monitoring circuit performs the search again. Even if the reproduction operation is repeated, previous information can be referred to, and program management information can be constantly monitored.

In addition, by operating a reset button (not shown), turning on the power, ejecting the cassette, etc., the first . Second register 35.
36, the comparison control section 37, the comparison section 38, the flag latch circuit 39, and the display section 16 are all reset to the initial state, and the information up to that point can be cleared.

Incidentally, in the above embodiment, the operation of the program monitoring circuit was explained in the search operation, but since the tape is running and it is sufficient to read the subcode information, for example, the playback mode, the playback mode, and the search operation are repeated. Even if this is done, exactly the same effects can be obtained.

Furthermore, in the above embodiment, if there is a discrepancy in the subcode management information, a warning flag is displayed to indicate that there is an error on the display section 1G, but there are many errors in the program management information, and the search itself If the user is unable to perform the search, the search operation can be canceled at the same time as the warning is issued. Furthermore, when an error is discovered, the user may be able to select whether to continue or cancel the search, and various applications are possible.

(Effects of the Invention) As described above, according to the program monitoring circuit in the digital tape recorder of the present invention, the flag P which determines whether the flag 5-ID indicating the program start point and the program number PNO in the subcode information is valid or invalid. -I
D is input at the same time, valid program numbers PNO are sequentially transferred to the register, and the input program number is compared with the program number input immediately before it, at least in terms of magnitude. We constantly monitor whether there is any discrepancy with the tape running direction, and if there is a discrepancy, a warning is displayed, so the program on the tape is If there is a discrepancy between the tape and the program control information, and the tape cannot be searched smoothly along the 7-ohm scale, the user will be made aware of this immediately, and the user will be informed that the cheap record is malfunctioning. It is possible to prevent misunderstandings, eliminate user anxiety, and save wasted time and effort during search operations.

Furthermore, since the present invention does not use the TOC to discover inconsistencies in program management information, it can be applied to cases where there are inconsistencies in the TOC management information or to tapes on which no TOC is recorded. The effect is great.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the program monitoring device of the present invention, FIG. M2 is a block diagram of the entire digital tape recorder of the present invention, and FIG.
Fig. 4 (a) to (d) show the details of the track 7t-mat, and Fig. 5 shows the cONTROL-ID flag set in the subcode information.
#6 diagram shows flags 5-ID and P-1D in the subcode information
, T-ID, and PNO (PNO-ID)l:, ): respectively indicate program management patterns. Explanation of symbols 1...Tape drive mechanism 11...Controller 7 Revlock 24...Signal processing block 34...Program monitoring circuit 35...First register 36...Second register 37...・Comparison control section 38... Comparison section 3
9...Flag latch circuit 40...Timing generation circuit 41...Reset circuit 5-10...START-10P-10...PR
IORTTY-10T-10・-・Toe-ID
PNO...PROGRAM NUMBER Name of patent applicant Aiwa Co., Ltd. Figure 3 GUARDBANOQPTIONTRAC Figure 6

Claims (1)

[Claims] A track recorded on the tape has at least a PCM area in which an audio signal etc. is converted into PCM and recorded, and subcode information in which management information of the program recorded in the PCM area is recorded, and based on the subcode information. The digital tape recorder is a digital tape recorder that selects programs, cues, etc., and includes a START-ID flag in the subcode information that indicates the starting point of a program, and a PRIORITY-I flag that is used to determine whether a program number is valid or invalid.
A program number is read at the timing when the D flag is raised at the same time, and the result of comparing the program number with the program number read immediately before, at least in terms of magnitude, and the program numbers read from the tape running direction are in ascending order. In the digital tape recorder, the digital tape recorder is configured to display that there is an error in the program management information by setting a warning flag when a discrepancy occurs between the results of determining whether the program management information is in descending order or in descending order. Program monitoring equipment.