KR20010073788A - Apparatus and method for additional information recording and reproducing of magnetic tape - Google Patents

Abstract

PURPOSE: A device and a method for recording/playing back additional information are provided to record a CTL signal with an additional information data regardless of location of a -CTL pulse on a control track of a magnetic tape. CONSTITUTION: A memory unit(10) stores an additional information to be recorded on a magnetic tape or played back from the magnetic tape. A system interface unit(30) receives the additional information from a system control unit or outputs the played back information to the system. A memory interface unit(20) withdraws or records the additional information by controlling the memory unit. An ECC(Error Correction Code) generate unit(50) ECC encodes and decodes the additional information. An ECC operate unit(40) outputs or eliminates the ECC from the played back additional information. A format/modulate unit(60) adds an amble signal and a synchronizing signal to the input data from the ECC operate unit. A recording current generate unit(70) converts the modulated data into a magnetic current to be recorded on the magnetic tape. A demodulate unit(80) reads a control track of the tape for demodulating and outputting the additional information to the ECC operate unit.

Description

APPARATUS AND METHOD FOR ADDITIONAL INFORMATION RECORDING AND REPRODUCING OF MAGNETIC TAPE}

The present invention relates to an apparatus and method for recording / reproducing additional information of a magnetic tape, and more particularly to an apparatus and method for recording / reproducing a magnetic tape which enables to record a CTL signal and additional information data on a control track of the magnetic tape. It is about.

In general, the signals recorded on the magnetic tape are recorded in the helical track, the audio signals are recorded in the audio track on the tape as shown in FIG. The CTL signal to synchronize the signal is recorded in the control track at the bottom of the tape.

On the other hand, in the case of digital VR, the digital data in which video and audio are combined is recorded in the helical track, and the CTL signal is recorded in the control track as in the case of analog VAL.

Here, the CTL signal is composed of a + CTL pulse and a -CTL pulse as shown in FIG. 2, and the recording period is changed according to the feed speed of the tape. In the case of standard play (SP), 33.3 m It is recorded every certain period of / sec, and in the case of expanded play (EP), 1/3 of standard play (SP) is shortened to 1/3 of the distance between CTL signals.

In this case, the position of the -CTL pulse may be changed for a search function such as a VHS Index Search System (VISS) or a VHS Address Search System (VASS), but in general, a CTL pulse may be changed as shown in FIG. It will be at 60% position in the cycle, and at VISS it will be at 40% position as shown in (b).

As shown in FIG. 2, the CTL signal has a blank area between the pulses and the pulses, and by recording various additional information in the control track of the blank area, various functions or services can be provided to the user. will be.

However, in order to record / reproduce the additional information on the control track as described above, the most important consideration is the processing of the -CTL pulse, whereas the CTL signal is recorded with a large recording current, whereas the additional information data is a small current of high frequency. This is because when additional information is recorded in addition to the CTL recording current, the additional information data recorded in duplicate with the -CTL pulse cannot be detected.

Therefore, in order to solve the above problems, there is a method of increasing the ECC (Error Correction Code) correction capability. However, this method does not have good characteristics of the channel (magnetic tape) including the VTL CTL head. Since a lot of redundancy for correcting an error caused by the -CTL pulse needs to be added during reproduction, the information weight for error correction is increased and the amount of recordable additional information is reduced.

Accordingly, the present invention has been made to solve the above-mentioned conventional problems, and the addition of a magnetic tape to enable recording of the CTL signal and additional information data together on the control track of the magnetic tape regardless of the position of the -CTL pulse. It is an object of the present invention to provide an information recording / reproducing apparatus and method.

1 is an exemplary view showing a track configuration of a magnetic tape.

FIG. 2 is a general waveform diagram of a CTL signal recorded on the control track in FIG.

Fig. 3 is a block diagram showing the configuration of the additional information recording / reproducing apparatus of the magnetic tape according to the present invention.

4 is an exemplary view showing a configuration of a data block.

5 is an exemplary diagram showing a symbol format of a data block to be written during a short CTL period according to the present invention.

Figure 6 is an exemplary view showing the format of a plurality of data blocks to be written during a long CTL one cycle by the present invention.

*** Description of the symbols for the main parts of the drawings ***

10: memory unit 20: memory interface unit

30: system interface unit 40: ECC operation unit

50: ECC generator 60: format / modulator

70: recording current generating unit 80: demodulation unit

The present invention for achieving the above object comprises: a memory unit for storing the additional information to be recorded on the magnetic tape from the system or the additional information reproduced on the magnetic tape; A system interface unit for receiving additional information data to be recorded on the magnetic tape from the system or outputting reproduced additional information data to the system; A memory interface for controlling the memory to retrieve or record additional information to be recorded on the tape or reproduced additional information; An ECC generation unit for ECC encoding and decoding additional information to be recorded on the tape; An ECC operation unit outputting the ECC to the ECC generation unit at an appropriate timing or removing the ECC from the additional information recorded / reproduced on a magnetic tape; A format / modulator for adding an amble signal, a synchronization signal, etc. to data input from the ECC operator, converting it into a predetermined format, and performing a modulation process for recording on a tape; A recording current generator for converting the data modulated by the format / modulator into magnetization current for recording on a magnetic tape through a head; And a demodulation unit configured to read the control track of the magnetic tape recorded through each of the components to demodulate the additional information and output the demodulated information to the ECC operating unit.

Hereinafter, an embodiment according to the present invention will be described in detail with reference to the accompanying drawings.

First, Fig. 3 is a block diagram showing the configuration of the additional information recording / reproducing apparatus of the magnetic tape according to the present invention. As shown in this figure, the additional information to be recorded on the magnetic tape from the system or the additional information reproduced on the magnetic tape is stored. A memory unit 10 for performing; A system interface unit 30 for receiving additional information to be recorded on the magnetic tape from the system control unit or outputting the reproduced additional data to the system; A memory interface unit 20 for controlling the memory unit 10 to retrieve or record additional information to be recorded on the tape or reproduced additional information; An ECC generator 50 for ECC encoding and decoding additional information to be recorded on the tape; An ECC operation unit 40 which outputs the ECC to be recorded on the ECC generating unit 50 or the magnetic tape at an appropriate timing or removes the ECC from the reproduced additional information; A format / modulator (60) for adding an amble signal and a synchronization signal to data input from the ECC operator (40), converting it into a predetermined format, and performing a modulation process for recording on a tape; A recording current generator 70 for converting the data modulated by the format / modulator 60 into a magnetizing current for recording on a magnetic tape through a head; The demodulation unit 80 reads the control tracks of the magnetic tape recorded through the respective configuration units, demodulates additional information, and outputs the demodulated information to the ECC operation unit 40. Hereinafter, the operation and operation of the present invention configured as described above will be described. Is as follows.

First, the ECC operation unit 40 receives additional information to be recorded, outputs the ECC generation unit 50 for error correction, encodes the encoded data, and outputs the encoded data to the format / modulator 60 to FIG. 5 or 6. A synchronization signal and an amble signal may be added in the form of.

The recording current generating unit 70 is a part for controlling the direction of the current in the forward direction and the reverse direction in order to apply additional information to a head (not shown) that converts the electric signal into a magnetic signal, that is, magnetization so that residual magnetic flux can be left on the tape. Will generate a current.

Accordingly, when the magnetization current as described above is applied to the tape through the head, the magnetization pattern of the additional information is recorded.

Next, the demodulation unit 80 reads the control track of the tape during reproduction to detect synchronization, demodulates the information on the start time and the end time of the additional information reproduction signal processing, and outputs it to the ECC operation unit 40 to correct the error. Decode the output to the system.

Next, the role of the format / modulator 60 for generating a data format for recording the additional information without reproducing the error by the -CTL pulse will be described in more detail.

4 is an exemplary view showing the configuration of a data block serving as a recording unit, and is composed of a plurality of symbols (for example, eight), and the bit size of the symbol, which is the minimum unit of the data block, is the best for the characteristics of the channel. It is determined that effective error correction can be made.

In this case, when the upper four symbols AS0 to AS3 of the data block are referred to as the upper symbol AH and the lower four symbols AS4 to AS7 are referred to as the lower symbol AL, the CTL of the control track according to the present invention. The recording format of the additional information data recorded in the section will be described with reference to FIG.

FIG. 4 is an exemplary diagram showing a symbol format of a data block to be recorded in one short CTL section according to the present invention. In the first CTL section of a continuously repeated CTL signal, the upper symbol AH and Record in the correct order of the lower symbols (AL).

Of course, at this time, the amble signal Amble for restoring the reproduction clock is positioned at the beginning of the data block, and the sync signal Sync for synchronization detection is positioned after the two symbols AS0 and AS1.

Next, the data block A is repeatedly recorded in the second CTL section following the first CTL section, but in this case, the order of the upper symbol (AH) and the lower symbol (AL) of the data block is reversed ( As shown in b), the lower symbol AL is recorded first, and the upper symbol AH is recorded later.

In this way, even if the position of the -CTL pulse is the normal position or the position of the VISS, the information of the symbol recorded at the -CTL position can be replaced in the copy data block recorded in a reverse order, thereby restoring.

That is, in the case of FIG. 5, two symbols AS3 and AS4 overlap the -CTL pulse in the first CTL section, and two symbols AS7 'and AS0' overlap the -CTL pulse in the second CTL section. When the data block of the first CTL section is reproduced, the two symbols AS3 and AS4 duplicated with the -CTL signal can be replaced by the same symbols AS3 'and AS4' of the copy data block.

However, V-Cal may have various modes with different recording speeds. For example, in the case of standard play (SP), the VR may have a CTL period that is three times the length of the CTL period in the expanded play (EP).

Accordingly, depending on the size of the data block, a plurality of data blocks (A, B, C ...) may be recorded in one CTL section. In this case, the case of FIG. Write a block of data.

For example, as shown in (a) of FIG. 6, an amble signal is recorded at the beginning of the data blocks recorded in the first CTL section as in the case of FIG. 5, and then the upper symbols and the lower symbols of one data block are thereafter. If the symbol is repeatedly recorded in the reverse order of the normal order (AH, AL, A'L, A'H), and only the data blocks in the normal order cannot be recorded repeatedly (BH, BL), (b) As shown in FIG. 2, the data blocks B'L and B'H in the reverse order are recorded in the second CTL section, and then other data blocks C and D ... are recorded.

As described above, the apparatus and method for recording / reproducing additional information of the magnetic tape of the present invention can provide various functions or services to the user by allowing the CTL signal and additional information data to be recorded together on the control track of the magnetic tape. There is an effect that can create a variety of added value using this.

Claims (5)

A memory section for storing additional information to be recorded on the magnetic tape from the system or additional information reproduced on the magnetic tape; A system interface unit for receiving additional information data to be recorded on the magnetic tape from the system or outputting reproduced additional information data to the system; A memory interface for controlling the memory to retrieve or record additional information to be recorded on the tape or reproduced additional information; An ECC generator for encoding and decoding ECC on additional information to be recorded on the tape; An ECC operation unit outputting the ECC to the ECC generation unit at an appropriate timing or removing the ECC from the additional information recorded / reproduced on a magnetic tape; A format / modulator for adding an amble signal, a synchronization signal, etc. to data input from the ECC operator, converting it into a predetermined format, and performing a modulation process for recording on a tape; A recording current generator for converting the data modulated by the format / modulator into magnetization current for recording on a magnetic tape through a head; And a demodulation section for reading the control track of the magnetic tape recorded through the components, demodulating the additional information, and outputting the demodulated information to the ECC operation unit. In the redundant recording of additional information data in a control track in which a CTL signal of a magnetic tape is recorded, the format of each symbol constituting the data block is recorded in the first section and the second section of the CTL signal repeated at regular intervals. A method of recording additional information on a magnetic tape characterized by the above-mentioned. The method according to claim 2, wherein if the repetition period of the CTL signal is long, data blocks formatted in a different order from data blocks formatted in a normal order are sequentially recorded in one CTL signal section, and then the data blocks not recorded are next CTL signals. And recording information at the beginning of the section. The method of claim 2 or 3, wherein the order of the formatted symbols is to divide the symbols constituting the data block in half, and to record the data symbols in the order of the upper symbols and the lower symbols. The recording method for recording additional information on a magnetic tape, characterized in that the recording is arranged in the order of the lower symbol and the upper symbol. In reproducing additional information data that is overwritten with a CTL signal on a control track of a magnetic tape, a symbol of a data block in which an error is caused by a -CTL signal in a CTL signal section is a symbol that is recorded in a subsequent CTL signal section. And additional information reproducing method of magnetic tape.