KR19990040839A - Video tape recorder with data backup - Google Patents

Abstract

In the video tape recorder having a data backup function according to the present invention, a luminance signal (Y) and a color signal (chrominance (C)) are separated from an image signal, and the luminance signal is FM (Frequency Modulation) modulated and the color signal is low-pass converted. After superimposing and recording the two, the pseudo video signal obtained by modulating the data to be backed up is recorded and stored on a video tape, but the actual effective luminance signal among the pseudo video signals is extended by the frequency band for the color signal. By FM-modulated recording in the band, a larger amount of backup data can be stored on video tapes of the same length of time.

Description

Video tape recorder with data backup

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video tape recorder having a data back-up function. In particular, the present invention relates to a video tape recorder by modulating data to be backed up (hereinafter referred to as backup data) in the form of an image signal. A video tape recorder having a data backup function for recording and storing a video tape.

In general, a video tape recorder is a device for recording or playing a video signal on a video tape. Recently, a method of using the video tape recorder as a data backup device for storing and preserving a large amount of data has been proposed. A video tape recorder with the function is introduced.

The video tape recorder having the above data backup function receives backup data from a computer, adds a horizontal synchronization signal and a vertical synchronization signal at appropriate intervals, modulates them into a video signal, and records and stores them on the video tape. The pseudo image signal obtained by modulating the backup data is the same as when recording the actual image signal input from the outside. That is, the luminance signal is separated from the luminance signal (Y) and the color signal (chrominance (C)). Frequency Modulation (FM) Modulation and low-frequency conversion are performed on the video tape by a low-conversion recording method in which the two signals are superimposed and then superimposed.

In the video tape recorder as described above, the backup data is represented only by the luminance signal among the pseudo video signals obtained by modulating it. That is, only the luminance signal-including the horizontal synchronization signal and the vertical synchronization signal-exists in the pseudo image signal, but no color signal exists. This means that the frequency band allocated for the color signal can be used to record the luminance signal during data backup. In other words, the luminance signal can be FM-modulated and recorded in the frequency band extended by the frequency band for the color signal. Means.

In view of the fact that the wider the frequency bandwidth during FM modulation, the better the ability to express the original signal in both quantitative and quantitative terms, as described above, if the luminance signal is FM-modulated and recorded in the extended frequency band, Obviously, more backup data can be stored on video tapes of the same length of time.

However, the above-described video tape recorder records FM-modulated luminance signals in the same frequency band as in the case of recording normal video signals during data backup, and thus a large loss occurs in the amount of data recorded on the video tape.

Therefore, in view of the above points, the present invention provides FM modulation of a luminance signal to a frequency band extended by a frequency band for color signals during data backup so that a larger amount of backup data can be stored on a video tape of the same time length. It is an object of the present invention to provide a video tape recorder having a data backup function for recording.

1 is a block diagram showing a detailed configuration of a preferred embodiment of a video tape recorder having a data backup function according to the present invention;

2 is a view showing a frequency band for a luminance signal in the recording mode in the present invention.

3 is a diagram illustrating a frequency band for a luminance signal in a data backup mode in the present invention.

4 is a block diagram showing a detailed configuration of another embodiment of a video tape recorder having a data backup function according to the present invention.

<Explanation of symbols for the main parts of the drawings>

10: data modulator 20: luminance signal / color signal separation unit

30: first switching switch 30a: second switching switch

30b: third switching switch 40: low-pass converter

50: low pass filter 60: FM modulator

61: first FM modulator 62: second FM modulator

70 band pass filter 71 first band pass filter

71: first band pass filter 80: magnetic recording unit

81: recording amplifier 82: magnetic head

100: video tape recorder

In order to achieve the above object, the present invention separates the luminance signal and the color signal from the image signal through the luminance signal / color signal separation unit, the luminance signal is FM-modulated through the FM modulator, and the color signal is low-frequency converted through the low pass converter. Recording and storing the pseudo video signal obtained by modulating the backup data through the data modulator in a videotape according to a method of superimposing the data; According to a mode selected by the user, the color signal is selectively removed through the color signal removing unit, and the luminance signal is FM-modulated to a predetermined first frequency band or a predetermined second frequency band having different bandwidths. do.

Here, the second frequency band is a frequency band for the luminance signal in the data backup mode and includes a frequency band for the first frequency band for the luminance signal and the frequency band for the color signal in the recording mode.

According to the present invention having such a feature, if the data of the pseudo image signal is actually FM-modulated and recorded in the frequency band extended by the frequency band for the color signal, the larger amount of backup data is recorded on the same length of video tape. Can be stored.

Preferably, the FM modulator comprises: a first FM modulator for FM modulating a luminance signal in a first frequency band, a second FM modulator for FM modulating a luminance signal in a second frequency band, and a mode selected by a user. And switching means for switching the luminance signal to be input to the first FM modulator or the second FM modulator.

In addition, the video tape recorder of the present invention also includes a bandpass filter unit for filtering the FM modulated luminance signal into a predetermined frequency band, as the conventional video tape recorder includes a bandpass filter unit. Accordingly, the luminance signal output from the FM modulator may be filtered to the first frequency band or the second frequency band.

Accordingly, the bandpass filter unit includes a first bandpass filter unit for filtering the luminance signal output from the first FM modulator into the first frequency band, and a luminance signal output from the second FM modulator into the second frequency band. It is preferable to comprise a second bandpass filter for filtering.

Hereinafter, the preferred embodiment of the present invention will be described in detail with reference to FIG. 1.

1 is a block diagram showing a detailed configuration of a preferred embodiment of a video tape recorder having a data backup function according to the present invention, as shown in the video tape recorder having a conventional data backup function. And a luminance signal / color signal separation unit 20, a low pass conversion unit 40, a low pass filter unit 50, an FM modulator 60, a band pass filter unit 70, and a magnetic recording unit 80.

In this case, the FM modulator 60 is composed of a first FM modulator 61 and a second FM modulator 62, and the bandpass filter unit 70 is also the first and second FM modulator 61. Corresponding to (62), each of the first bandpass filter section 71 and the second bandpass filter section 72 is composed of.

Here, the first FM modulator 61 and the first bandpass filter 71 are for modulating and filtering the luminance signal in a predetermined first frequency band in the recording mode, and the second FM modulator 62 And the second band pass filter 72 are for modulating and filtering the luminance signal in a predetermined second frequency band in the data backup mode. Frequency bands corresponding to the respective modes are shown in FIGS. 2 and 3. . 2 and 3, the second frequency band B2 for the luminance signal Y in the data backup mode covers the low frequency band for the color signal C in the first frequency band B1 for the luminance signal Y in the recording mode. Has bandwidth.

A switching switch 30a is interposed between the luminance signal / color signal separation unit 20 and the FM modulation unit 60, which is switched according to a mode selected by the user and separated from the luminance signal / color signal separation unit 20. The luminance signal Y is input to the first FM modulator 61 or the second FM modulator 62.

In addition, a switching switch 30b is interposed between the luminance signal / color signal separation unit 20 and the low pass conversion unit 40, which is switched according to a mode selected by the user, thereby separating the luminance signal / color signal from the low pass conversion unit 40. The color signal C separated in the unit 20 is input or a ground voltage is input. The switching switch 30b may also be located between the low pass filter unit 50 and the magnetic recording unit 80.

The two switching switches 30a and 30b are switched according to a mode selected by a user so that an actual video signal is input from the outside to the luminance signal / color signal separation unit 20 or the data modulation unit 10 It is interlocked with another switching switch 30 for inputting an output pseudo video signal. That is, the three switching switches 30, 30a, 30b are interlocked with each other according to the mode selected by the user, and the following are switched to each of the first switching switch 30 and the second switching switch, respectively. 30a and 3rd switch 30b are called.

The video tape recorder 100 of the present invention having such a configuration may have various modes according to functions as in the conventional video tape recorder, but basically has two modes related to recording signals on the video tape, These are respectively a data backup mode for storing backup data and a recording mode for recording video signals.

The video tape recorder 100 of the present invention operates as follows as each of the two modes is selected.

First, when the recording mode is selected by the user, the contact point of the first switching switch 30 is switched to any one side so that the actual video signal is input to the luminance signal / color signal separation unit 20 from the outside, whereby the luminance signal Y And color signal C are separated.

The luminance signal Y separated by the luminance signal / color signal separation unit 20 is connected to the first switching switch 30 so that the contact point of the second switching switch 30a is switched to any one side of the first FM modulator ( 61, which is FM-modulated into the first predetermined frequency band B1 by the first FM modulator 61 and then filtered by the first bandpass filter 71 into the first frequency band B1. That is, the luminance signal Y is FM modulated and filtered in the first frequency band B1.

The color signal C separated by the luminance signal / color signal separation unit 20 is connected to the first switching switch 30 and the second switching switch 30a so that the contact point of the third switching switch 30b is switched to any one side. Accordingly, the low frequency converter 40 is input to the low frequency converter 40, which is low-pass converted to a predetermined low frequency band by the low frequency converter 40, and then filtered to the low frequency band through the low pass filter 50. That is, the color signal C is subjected to FM modulation and filtering in the low frequency band.

As such, the luminance signal Y filtered through the first bandpass filter unit 71 and the color signal C filtered through the lowpass filter unit 50 are superimposed on each other and then amplified by the recording amplifier 81, and thus, the magnetic head 82. Is recorded on a video tape (not shown).

That is, in the recording mode, both the luminance signal Y and the color signal C of the actual video signal are recorded on the video tape.

Now, when the data backup mode is selected by the user, the contact point of the first switching switch 30 is switched to the other side, and the pseudo image signal output from the data modulator 10 is input to the luminance signal / color signal separator 20. Like the real video signal, the luminance signal Y and the color signal C are separated. The backup data earlier than this is transmitted from a computer (not shown), and is modulated by the data modulator 10 into a pseudo image signal to which a horizontal synchronous signal and a vertical synchronous signal are added.

The luminance signal Y output from the luminance signal / color signal separation unit 20 is connected to the first switching switch 30 so that the contact point of the second switching switch 30a is switched to the other side. Is inputted into the second FM modulator 62, and then FM-modulated into a predetermined second frequency band B2 covering the first frequency band B1 and the low frequency band, and then through the second bandpass filter unit 72. Filtered to the second frequency band B2. That is, the luminance signal Y is FM-modulated and filtered in the second frequency band B2, which has an increased bandwidth than in the recording mode.

However, as the contact point of the third switching switch 30b is switched to the other side in conjunction with the first switching switch 30 and the second switching switch 30a, the low voltage converter 40 receives a ground voltage instead of the color signal C. The low voltage converter 40 and the low pass filter 50 may output the same ground voltage even when the low frequency conversion or filtering process is performed. As a result, it can be said that the color signal C output from the luminance signal / color signal separation unit 20 is removed. In fact, since the color signal C does not exist in the pseudo image signal, the color signal C is not output from the luminance signal / color signal separation unit 20, but by doing so, the noise signal remaining in the frequency band for the color signal C is removed.

Therefore, only the luminance signal Y filtered through the second band pass filter unit 72 is amplified by the recording amplifier 81 and recorded on the video tape through the magnetic head 82.

That is, in the data recording mode, only the luminance signal Y of the pseudo video signal is recorded on the video tape. However, since the frequency band B2 for the luminance signal Y at this time is extended by the low frequency band for the color signal C, a larger amount of backup data is stored in the video tape of the same time length.

Hereinafter, another embodiment of a video tape recorder having a data backup function according to the present invention will be described in detail with reference to FIG. 4.

Another embodiment of the present invention focuses on the fact that the color image component is not included in the pseudo image signal at the time of data backup, and the pseudo image signal is directly passed through the second FM changer ( 62).

Figure 4 is a block diagram showing a detailed configuration of another embodiment of a video tape recorder having a data backup function according to the present invention, to facilitate understanding thereof, perform a function similar to the preferred embodiment of the present invention shown in FIG. The same reference numerals will be given to constituent elements.

Another embodiment of the present invention is similar to the preferred embodiment of the present invention, as in the video tape recorder having a conventional data backup function, the data modulator 10, the luminance signal / color signal separator 20, the low-pass converter ( 40, a low pass filter unit 50, an FM modulator 60, a band pass filter unit 70, and a magnetic recording unit 80.

Here, the FM modulator 60 is composed of a first FM modulator 61 and a second FM modulator 62, and the band pass filter 70 also includes the first and second FM modulators 61, Corresponding to (62), respectively, the first band pass filter section 71 and the second band pass filter section 72, the first FM modulator 61 and the first band pass filter section 71 In the recording mode, the luminance signal is modulated and filtered in a predetermined first frequency band, and the second FM modulator 62 and the second band pass filter 72 provide a predetermined luminance signal in the data backup mode. For modulation and filtering in two frequency bands.

In this case, the first FM modulator 61 directly receives the output of the luminance signal / color signal separator 20 without switching, and the second FM modulator 62 receives the output of the data modulator 10 without switching. Another embodiment of the present invention is distinguished from the above-described preferred embodiment of the present invention in that it is directly input. As such, the reason why the luminance signal / color signal separation (so-called Y / C separation) is not performed on the output of the data modulator 10 through the luminance signal / color signal separation unit 20 is based on the pseudo image signal during data backup. The idea is that the color signal component is not included.

Accordingly, a switching switch 30c is interposed between the bandpass filter unit 70 and the magnetic recording unit 80, which is the first bandpass filter unit 71 and the second bandpass filter unit according to the mode selected by the user. 72 is switched so as to be combined with the output of the low pass filter 50 and input to the magnetic recording unit 80.

In addition, a switching switch 30b is interposed between the luminance signal / color signal separation unit 20 and the low pass conversion unit 40, which is switched according to a mode selected by the user, thereby separating the luminance signal / color signal from the low pass conversion unit 40. The color signal C separated in the unit 20 is input or a ground voltage is input. The switching switch 30b may also be located between the low pass filter unit 50 and the magnetic recording unit 80.

The two switching switches 30b and 30c are interlocked and switched together according to the mode selected by the user.

In another embodiment according to the present invention, the video tape recorder 100 operates as follows.

First, when the recording mode is selected by the user, the actual video signal is input to the luminance signal / color signal separation unit 20 from the outside and separated Y / C into the luminance signal Y and the color signal C.

The luminance signal Y separated by the luminance signal / color signal separator 20 is input to the first FM modulator 61, which is FM-modulated to the first predetermined frequency band B1 by the first FM modulator 61. The first bandpass filter unit 71 filters the first frequency band B1. That is, the luminance signal Y is FM modulated and filtered in the first frequency band B1.

On the other hand, the color signal C separated by the luminance signal / color signal separation unit 20 is input to the low frequency conversion unit 40 as the contact point of the switching switch 30b is switched to any one side, which is the low frequency conversion unit 40. In the low frequency band is converted to a predetermined low frequency in the low-pass filter unit 50 is filtered through the low frequency band. That is, the color signal C is subjected to FM modulation and filtering in the low frequency band.

Luminance filtered through the first bandpass filter part 71 as the switching switch 30c interposed between the bandpass filter part 70 and the magnetic recording part 80 is switched to the first bandpass filter part 71. The signal Y and the color signal C filtered through the low pass filter section 50 are superimposed on one another and then amplified by the recording amplifier 81 and recorded on a video tape (not shown) through the magnetic head 82.

That is, in the recording mode, both the luminance signal Y and the color signal C of the actual video signal are recorded on the video tape.

Now, when the data backup mode is selected by the user, the data modulator 10 generates a pseudo image signal in which a horizontal synchronization signal and a vertical synchronization signal are added to backup data transmitted from a computer (not shown).

The output of the data modulator 10 is input to the second FM modulator 62, which is a predetermined second frequency band covering the first frequency band B1 and the low frequency band in the second FM modulator 62. After FM modulation to B2, the second bandpass filter unit 72 filters the second frequency band B2. That is, the luminance signal Y is FM-modulated and filtered in the second frequency band B2, which has an increased bandwidth than in the recording mode.

At this time, the switching switch 30c interposed between the band pass filter unit 70 and the magnetic recording unit 80 is switched to the second band pass filter unit 72.

Meanwhile, as the contact point of the switching switch 30b is switched to the other side in conjunction with the switching switch 30c, the low frequency converter 40 receives a ground voltage instead of the color signal C, which is changed even if the low frequency conversion or filtering is performed. Since the low-pass converter 40 and the low-pass filter unit 50 do not have this same ground voltage as the output. As a result, it can be said that the color signal C output from the luminance signal / color signal separation unit 20 is removed.

Therefore, only the luminance signal Y filtered through the second band pass filter unit 72 is amplified by the recording amplifier 81 and recorded on the video tape through the magnetic head 82.

That is, in the data recording mode, only the luminance signal Y of the pseudo video signal is recorded on the video tape. However, since the frequency band B2 for the luminance signal Y at this time is extended by the low frequency band for the color signal C, it is well known that a larger amount of backup data is stored in a video tape of the same length of time.

As described in detail above, according to the present invention, the same time is obtained by FM-modulating the effective luminance signal among pseudo image signals obtained by modulating the data to be backed up during data backup to a frequency band extended by a frequency band corresponding to the color signal. Not only can a larger amount of backup data be stored on a length of video tape, but it also has the effect of significantly reducing errors that can be caused by limited bandwidth.

Claims (9)

A data modulator for receiving data to be backed up and modulating the data into a video signal; A luminance signal / color signal separator for separating the luminance signal Y and the chrominance C from the image signal; First switching means for switching the actual video signal input from the outside or the pseudo video signal output from the data modulator according to the mode selected by the user to be input to the luminance signal / color signal separation unit; A frequency modulation (FM) modulator for FM modulating the luminance signal into a predetermined frequency band; A low-pass converter for low-pass converting the color signal into a predetermined low frequency band; A color signal removing unit for removing the color signal according to the mode selected by the user; And A magnetic recording section for superimposing the FM modulated luminance signal and the low frequency converted color signal on a video tape; The FM modulator, And the FM signal is modulated into the predetermined first frequency band or the predetermined second frequency band having different bandwidths according to the mode selected by the user. The method of claim 1, wherein the FM modulator, A first FM modulator for FM modulating the luminance signal into the first frequency band; A second FM modulator for FM modulating the luminance signal into the second frequency band; And And a second switching means for switching the luminance signal to be input to the first FM modulator or the second FM modulator in accordance with a mode selected by the user. The method according to claim 1 or 2, And a band pass filter for filtering the luminance signal output from the FM modulator according to the mode selected by the user to the first frequency band or the second frequency band. Videotape recorder. The method of claim 3, wherein the band pass filter, A first bandpass filter for filtering the luminance signal output from the first FM modulator into the first frequency band; And And a second band pass filter for filtering the luminance signal output from the second FM modulator into the second frequency band. The method of claim 1, wherein the second frequency band, And a low frequency band and the first frequency band. A luminance signal / color signal separator for separating an actual luminance signal Y and an actual color signal C from an actual image signal; A first frequency modulation (FM) modulator for FM modulating the actual luminance signal into a first frequency band having a predetermined frequency band; First switching means which are respectively switched to the output and the ground of the luminance signal / color signal separation unit as a recording mode for recording the actual video signal and a data backup mode for storing backup data provided from a host computer are respectively selected; A low-pass converter for converting the actual color signal into a predetermined low frequency bandwidth as the first switching means is switched to the output of the luminance signal / color signal separator; A data modulator for receiving a data to be backed up in the data backup mode and modulating the data into a video signal to generate a pseudo video signal; A second frequency modulation (FM) modulator for receiving the pseudo image signal and performing FM modulation on the second frequency band obtained by adding up the first frequency band and the low frequency band; Second switching means for respectively switching to an output of the first FM modulator and an output of the second FM modulator as the recording mode and the data backup mode are respectively selected; And a magnetic recording section for superimposing the output of the second switching means and the output of the low-order conversion section on the video tape. 7. The apparatus of claim 6, further comprising a first bandpass filter for bandpass filtering the output of the first FM modulator to the first frequency band between the first FM modulator and the first band converter. A video tape recorder having a data backup function. 7. The method of claim 6, further comprising a second bandpass filter for bandpass filtering the output of the second FM modulator to the second frequency band between the second FM modulator and the second band converter. A video tape recorder having a data backup function. 7. The video tape recorder of claim 6, further comprising a low pass filter for low pass filtering the output of the low pass converter to the low frequency band.