KR19990031967A - Recording device for surveillance video cassette recorder - Google Patents

Abstract

The present invention relates to a surveillance video cassette recorder for automatically switching the recording speed mode according to whether a subject movement is detected.

Conventionally, the image quality is deteriorated by constantly recording in the EP mode regardless of whether the movement of the subject is detected. However, the present invention automatically converts the recording speed by detecting the movement of the subject.

For example, if the digital value of the movement of the subject is detected, the recording speed is maintained in the SP mode, and if the digital value of the movement of the subject is not detected, the recording speed is maintained in the EP mode.

Therefore, there is an effect that can accurately record the subject.

Description

Recording device for surveillance video cassette recorder

The present invention relates to a recording apparatus using a closed circuit television (CCTV), in particular, when the movement of the subject is detected during recording in the EP (Extended Play) mode, the subject automatically switches to the SP (Standard Play) mode to accurately correct the subject. A recording apparatus of a surveillance video cassette recorder for recording.

As is well known, a video cassette recorder has a recording function for recording a composite video signal applied from a tuner tuned in to a desired channel with a broadcast signal transmitted through an antenna, and for reproducing a composite video signal recorded on a magnetic tape. Has a playback function to display on a television monitor.

In addition, since the video cassette recorder has a reserved recording function, the scheduled recording function is used to schedule information input by a user (for example, a broadcast date, start time, end time, broadcast channel of a desired program, and recording speed of a desired program). It is a function that can reserve and record a broadcast program in advance by setting, and it is a very useful function to automatically record a broadcast program that a user wants in the absence of the user, so that the user can play and watch it next time.

The recording speed modes used when performing the scheduled recording or recording function are classified into SP (Standard Play) mode, LP (Long Play) mode, and EP (Extended Play) mode. The SP mode is a standard mode, and the LP mode is 2 The triple mode and the EP mode are three times. When the same amount of tape is used, the EP mode can record three times more information than the SP mode, and the LP mode can record twice as much information as the SP mode. Although there is an advantage, the EP mode can record three times more information than the SP mode, but has a disadvantage in that the image quality is much lower than that of the SP mode.

On the other hand, a surveillance video cassette recorder used for security purposes in places where public institutions or banks are frequently visited refers to a system for intermittently maintaining a recording state for a time set by a timer.

The surveillance video cassette recorder performs the recording speed mode in the EP mode in order to maintain the recording state for a long time. As described above, the EP mode has a problem in that the image quality is degraded so that the subject cannot be recorded accurately.

The present invention has been made to solve the above-mentioned problems, an object of the present invention is to change the current recording speed mode from the EP mode to the SP mode when the movement of the subject is detected during the recording of the surveillance video cassette recorder to maintain the recording state for a long time The present invention provides a recording apparatus of a surveillance video cassette recorder for converting and recording to accurately record a subject.

The present invention for achieving the above object, in the recording apparatus of the video cassette recorder for monitoring to record by switching the recording speed mode automatically in accordance with the movement of the subject, the image of the subject is converted into an electrical video signal provided A CCD imaging unit; A video signal processor which processes and provides a video signal provided by the CCD imager; A luminance signal separator for separating the luminance signal from the video signal provided by the video signal processor; An A / D converter converting a level value of the luminance signal provided by the luminance signal separator into a digital value; When the reference digital value for the level of the luminance signal in the absence of a subject is stored and the digital value is provided from the A / D converter, the stored reference digital value is compared with the previously stored reference digital value and the A / D conversion is performed. The recording speed control signal for recording in the EP mode is provided if it is larger than the digital value provided by the unit. If the pre-stored reference digital value is smaller than the digital value provided by the A / D converter, the recording is performed for recording in the SP mode. A microcomputer providing a speed control signal; And a recording unit for recording a video signal provided by the video signal processing unit in a recording speed mode corresponding to a recording speed control signal provided by the microcomputer.

The above objects and various advantages of the present invention will become more apparent from the preferred embodiments of the invention described below with reference to the accompanying drawings by those skilled in the art.

1 is a block diagram showing the configuration of a recording apparatus of a video cassette recorder for surveillance according to the present invention;

2 is a flowchart for performing a recording method of a video cassette recorder for surveillance according to the present invention.

<Description of Symbols for Main Parts of Drawings>

10: key metrics 20: micom

30 CCD imaging unit 40 video signal processing unit

50: luminance signal / color signal separation unit 60: A / D conversion unit

70: recording unit 80: playback unit

90: monitor

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

1 is a block diagram showing the configuration of a recording apparatus of a video cassette recorder for surveillance according to the present invention, a key matrix 10 for providing a key signal according to a user's control command, which captures a subject and converts it into an electrical video signal. A luminance signal for separating the luminance signal among the signals provided by the charge coupled device (CCD) imaging unit 30, the video signal processing unit 40 that processes the video signal provided by the CCD imaging unit 30, and the video signal processing unit 40. In the analog to digital (A / D) converting unit 60 and the A / D converting unit 60 for converting the level value of the luminance signal provided from the separating unit 50 and the luminance signal separating unit 50 into digital values, Recording is performed in the recording speed mode corresponding to the recording speed control signal provided by the microcomputer 20 and the microcomputer 20 that compares the digital value provided with the pre-stored digital value and provides a recording speed control signal corresponding to the comparison result. Undertake It consists of a recording unit 70, the reproduction unit 80 and a monitor 90 for reproducing a signal recorded in the recording section 70 under the control of the microcomputer 20.

Detailed operation description of the present invention configured as described above is as follows.

The key metrics 10 provide the microcomputer 20 with a signal for a key signal, for example, a recording key and a playback key, according to a user's control command.

At this time, the microcomputer 20 performs recording and playback operations according to the key signals provided from the key metrics 10.

Meanwhile, the CCD imaging unit 30 captures a subject and converts the imaging signal into an electrical signal, that is, a video signal, and provides the same to the video signal processing unit 40. At this time, the video signal processing unit 40 processes the video signal provided from the CCD imaging unit 30 and provides it to the luminance signal separation unit 50 and the recording unit 70.

That is, the luminance signal separator 50 separates the luminance signal from the video signal provided by the video signal processor 40 and provides it to the A / D converter 60, and the A / D converter 60 separates the luminance signal. The luminance signal level value provided by the unit 50 is converted into a digital value and provided to the microcomputer 20. This is because the digital value for the state where the subject is moving is different from the digital value for the state where the subject is not moving.

Accordingly, the microcomputer 20 stores a reference digital value, that is, a digital value for a state in which the subject does not move, and the digital value provided from the A / D converter 60 and the stored reference digital value as described above. Compare

That is, the microcomputer 20 determines that the movement of the subject is detected when the digital value provided from the A / D converter 60 is larger than the pre-stored digital value, so that the microcomputer 20 records the subject accurately in the EP recording mode. The recording speed control signal for switching to the recording mode is provided to the recording unit 70. In addition, if the digital value provided by the A / D converter 60 is smaller than the pre-stored digital value, the microcomputer 20 determines that there is no movement of the subject and controls the recording speed for switching from the SP mode to the EP recording mode. The signal is provided to the recording unit 70.

Accordingly, the recording unit 70 records the video signal provided by the video signal processing unit 40 according to the recording speed mode corresponding to the recording speed mode control signal provided by the microcomputer 20.

In addition, when the signal for the playback key is provided from the key matrix 10, the microcomputer 20 controls the playback unit 80 to play back the signal recorded in the recording unit 70. 80 reproduces the recorded signal and provides it to the monitor 90.

2 is a flowchart for performing a recording method of a video cassette recorder for surveillance according to the present invention, which will be described in detail with reference to the block diagram shown in FIG.

If the recording speed mode of the recording unit 70 is the EP mode in step 200, the microcomputer 20 detects the digital value of the current luminance signal level from the A / D converter 60 in step 210. .

In operation 220, the microcomputer 20 compares the digital value of the luminance signal level detected in operation 210 with the reference digital value of the preset luminance signal level. As a result of the comparison, if the digital value of the luminance signal level detected in step 210 is greater than the reference digital value of the preset luminance signal level, it is determined that the movement of the subject is detected. It provides a recording speed control signal for the recording unit 70, accordingly, the recording unit 70 switches to the SP mode to perform the recording.

On the other hand, the microcomputer 20 proceeds to step 240 and if the digital value of the luminance signal level provided from the A / D converter 60 is smaller than the reference digital value of the preset luminance signal level, the subject movement is not detected. In response, the control unit 70 controls the recording unit 70 to record from the SP mode to the EP mode and returns to step 200 to repeat the process.

The recording unit 70 records the video signal provided from the video signal processing unit 40 under the control of the microcomputer 20.

As described above, the recording apparatus of the surveillance video cassette recorder according to the present invention, if there is no movement of the subject to perform recording in the EP mode, and if the movement of the subject is detected, the recording is performed by switching from the EP mode to the SP mode. If the motion of the subject is not detected again, the recording is performed by switching from the SP mode to the EP mode, thereby accurately recording the subject.

While the invention has been shown and described with respect to certain preferred embodiments, it will be apparent to those skilled in the art that various modifications, changes and omissions can be made without departing from the spirit and scope of the invention.

Claims (1)

In the recording device of the surveillance video cassette recorder for recording by switching the recording speed mode automatically in accordance with the movement of the subject, A CCD imager which photographs the subject and converts the image into an electrical video signal to provide the image; A video signal processor which processes and provides a video signal provided by the CCD imager; A luminance signal separator for separating the luminance signal from the video signal provided by the video signal processor; An A / D converter converting a level value of the luminance signal provided by the luminance signal separator into a digital value; When the reference digital value for the level of the luminance signal in the absence of a subject is stored and the digital value is provided from the A / D converter, the stored reference digital value is compared with the previously stored reference digital value and the A / D conversion is performed. The recording speed control signal for recording in the EP mode is provided if it is larger than the digital value provided by the unit. If the pre-stored reference digital value is smaller than the digital value provided by the A / D converter, the recording is performed for recording in the SP mode. A microcomputer providing a speed control signal; And And a recording unit for recording a video signal provided by the video signal processing unit in a recording speed mode corresponding to a recording speed control signal provided by the microcomputer.