KR19990001703U - VSI system with copy protection - Google Patents

Abstract

The present invention relates to a VSI system having a copy protection function used to prevent unauthorized copying of an image tape, and a conventional copy protection device inserts a copy protection signal into a video signal and thus a copy protection signal is inserted. When playing back a tape, the picture quality is poor due to the video signal being out of sync, but copying is possible. Therefore, a means was needed to solve this problem more actively.

In order to solve such a problem, the present invention provides an output signal when a copy protection signal is inserted into the video signal output from the age unit 41, which always maintains a constant output gain level when performing the recording mode of the VSI system. Is compared with the reference voltage of the zener diode 42 and the comparator 43 outputting an active high signal when the reference voltage is higher than the reference voltage, and the active signal is switched from the comparator 43 to switch the video signal processing IC ( Provided is a VSI system including a transistor (Q1) circuit and the like for switching the FM luminance meter write modulation wave output from the FM modulator 44 of 40) to not be mixed with the low-conversion color signal and transmitted to the record amplifier 45 side. .

Description

VSI system with copy protection

The present invention relates to a VSI system having a copy protection function used to prevent unauthorized copying of an image tape. In particular, an output signal of a comparator is automatically input when a copy protection signal is inserted into a video signal and inserted into an age portion. By stopping the output of the recorder luminance signal FM modulated wave, the recording becomes impossible when the user copies the tape on which the copy protection signal is recorded in the video signal, thereby making the copy protection reliable.

The VSI system is an electronic device that is widely used with a TV receiver, and the conventional circuit of the system having a copy protection function by a VSI user in the VSI system is disclosed in Korean Patent Application Publication No. 1212, Publication No. 94-. 4567, the circuit block diagram of which is shown in FIG.

Here, a remote controller 21 which performs password input for copy protection, a preamplifier 22 which receives a signal transmitted from the remote controller 21 and provides it to the microcomputer 24, a function switch 23 and a microcomputer. Computer 24, deck portion 25, signal processing portion 26, vertical synchronization separation portion 28, divider 27, synchronous separation portion 29, OSD portion 30, amplifier 31, 32), rust switch 33, control head 34 and the like.

In such a system, when a user inputs a copy number for copy protection through the remote controller 21 or the like, the microcomputer 23 drives the deck unit 25 to perform recording, and the control head (a) through the amplifier (31). Providing an encryption pulse code at 34) resulted in the encryption information for copy protection being recorded on the control track of the tape being recorded.

For example, the encryption information recording process for copy protection in the control track of the tape in such a system is shown as shown in FIG.

In this case, it is checked whether the system is in the recording mode, and in the recording mode, the recording operation is performed (steps 310 and 320).

After that, the character display screen is output through OSD (Step 330). If the password input is completed, the password is entered. If the password is completed, the set password is recorded on the control track. When the process went to the input step or the end step, and not in step 310, the selected operation was performed (steps 340 to 370).

However, in such a conventional system, copy protection password information is recorded on a control track of a recording tape for copy protection, and a copy operation cannot be performed when there is no password input, but the password information is registered in a set on an OS program. When the tape copy is performed using a set in which such cipher information is not registered, the copy protection cipher record is disabled and a copy operation is arbitrarily performed.

Another prior art copy protection circuit includes a first VCR1 for reproducing contents recorded on an original tape and a second tape for reproducing contents of an image on a new tape as shown in FIG. The VCR2 is connected to each other through a video output line and a audio output line, and has a sudden level change in the video output line Video through which the video signal is output, and the signal is out of sync. The copy protection signal inserting circuit 10 for inserting the conduit was configured.

The conventional copy protection circuit having the above configuration reproduces the video signal and the audio signal recorded on the original video object in the first VCR1 and outputs them through the video output line and the audio output line. The copy protection signal insertion circuit 10 generates a copy protection signal having a sharp level fluctuation and a synchronization loss for copy protection, and puts it in the vertical blanking period of the video signal output to the video output line. The video signal mixed with the prevention signal and the audio signal passing through the audio output line Audio are recorded on a new tape in the second VCR2.

Therefore, when playing a new tape, it is possible to play back video signals without any problem.However, when copying a new tape to another tape, a copy protection signal recorded with the video signal causes problems such as interference on the copy screen. It is not allowed to be copied by the general consumer.

However, such a conventional copy protection circuit inserts a signal for copy protection into a video signal and reproduces a tape in which the copy protection signal is inserted. Therefore, a means was needed to solve this problem more actively.

An object of the present invention is to prevent the output of the recorder luminance signal FM modulation wave by the output signal of the comparator when the copy protection signal is inserted into the video signal so as to improve the above problems. The present invention provides a VSI system having a copy protection function that makes recording impossible when a user copies a tape on which a copy protection signal is recorded in a video signal.

The present invention is particularly effective when a copy protection signal is inserted into a video signal output from an age unit which maintains a constant output gain level in a recording receiver system when the recording mode of the VSI system is implemented so as to realize the object of the above example. The comparator outputs an active high signal when the output signal is compared with the reference voltage of the zener diode and exceeds the reference voltage. The modulated wave output from the FM modulator of the video signal processing IC is turned on by receiving an active high signal from the comparator. It is characterized in that it comprises a transistor circuit and the like which are mixed with the low-conversion color signal and are switched so as not to be transmitted to the write amplifier side.

Hereinafter, more specific features of the present invention will be understood by describing the same in detail with the accompanying drawings.

1 is a circuit block diagram of a conventional Video Cassette Recorder (VCR) system with copy protection;

Figure 2 is an example of the copy protection encryption recording program in Figure 1,

3 is a block diagram showing a conventional copy protection signal insertion circuit;

4 is a system circuit block diagram having a copy protection function according to the present invention.

** Explanation of symbols on the main parts of the drawing **

40: video signal processing IC 41

42: zener diode 43: comparator

44: FM modulator 45: record amplifier

As shown in FIG. 4, the present invention provides an output gain level of a recording reception system in a video signal processing IC 40 connected to an external line input system of a BC system, when a recording mode of the BC system is performed. When the copy protection signal is inserted into the video signal outputted from the age unit 41 which keeps the constant constant, the output signal is compared with the reference voltage of the zener diode 42 and the active high signal is generated. A comparator 43 for outputting is connected to the output side of the age unit 41.

In addition, a modulated wave output from the recorder FM modulator 44 generated by the video signal processing IC 40 is turned on by receiving an active high signal generated by the comparator 43 at the rear end of the comparator 43. A transistor (Q1) circuit that is mixed with the converted color signal and switched from being transmitted to the write amplifier 45 side is connected.

Referring to the operation of the present invention configured as described in detail as follows.

First, the user inserts the original program tape and the blank tape into the deck unit (not shown), such as VSI or VSI or duplexer, and copies the program contents of the original tape to the blank tape. The recording command is provided to the microcomputer (not shown) through a key input unit (not shown).

At this time, the microcomputer receives the original program signal from the outside while driving the blank tape and provides the recording signal to the video signal processing IC 40 through the age unit 41.

In particular, the age unit 40 automatically adjusts the input signal level when it changes so that the output gain level is always constant.

In general, the luminance signal passing through the age portion is transmitted to the recording amplifier through a low pass filter, an equalizer, a clamp circuit, a pre-emphasis, a white clip and a duck clip, an FM modulator, and a high pass filter, and finally a video head through a rotating transformer. Will be written on.

However, when a copy protection signal is inserted into the received video signal and input to the message unit 41, a higher voltage level signal corresponding thereto is output.

In addition, a comparator 43 having a voltage applied to the zener diode 42 as a reference voltage is provided between the age unit 41 and the output terminal of the FM modulator 44. The output voltage level of the age unit 41 is Zener. When the reference voltage level of the diode 42 is greater than that, the comparator 43 generates an active high output.

Therefore, when the composite signal mixed with the received video signal and the copy protection signal is applied to the (+) input terminal of the comparator 43 when the tape is copied and becomes larger than the reference voltage of the zener diode 42, the zener diode 42 is activated. It outputs a high signal and transistor Q1 is turned on accordingly.

When the transistor Q1 is turned on through such a series of operations, the luminance signal modulated from the FM modulator 44 of the video signal processing IC 40 falls to the ground point, thereby being mixed with the low-conversion color signal and recording amplifier 45 The luminance signal transmitted to) side is cut off.

Therefore, tape recording and recording of the luminance signal are impossible.

For reference, at this time, if the (-) input terminal of the comparator 43 corresponds to a pure video signal having a constant output level (for example, having a voltage less than the zener diode reference voltage) passing through the age unit 41 When an age level value is applied, the comparator 43 outputs a logic 0 signal, thereby causing the transistor Q1 to be turned off.

Therefore, in this case, the luminance signal modulated by the FM modulator 44 is mixed with the low-conversion color signal, transmitted to the recording amplifier 45, and then sent to the VSI head 46 where recording and recording are performed, thereby performing a normal recording operation. It is.

As described above, when the copy protection signal is inserted into the video signal and input to the age unit 41 of the video signal processing IC 40, the output of the luminance signal FM modulation wave is interrupted through the output signal of the comparator 43. As a result, when the user tries to copy the tape on which the copy protection signal is recorded in the video signal, the recording becomes impossible and the copy protection reliability can be achieved.

Claims (1)

A VSI system including a video signal processing IC 40 and the like, comprising: an age unit 41 for always maintaining a constant output gain level of a recording reception system when the system performs the recording mode, and the age unit 41; A comparator 43 connected to a rear end and outputting an active high signal when the output level output from the age unit 41 is equal to or greater than the reference voltage of the zener diode 42 and outputs an active high signal, and a rear end of the comparator 43. Connected to the active high signal of the comparator 43 so that the modulated wave output from the FM modulator 44 of the video signal processing IC 40 is mixed with the low-conversion color signal to be transmitted to the recording amplifier 45. And a transistor (Q1) circuit for preventing switching operation.