KR940008802B1 - Automatic reading method - Google Patents

Abstract

The method for automatically discriminating record mode includes the steps of counting the number of control pulse per unit time, comparing the counted value with a predetermined value if it is included in a fixed range of the number of control pulse per unit time, and if it is included therein, judging a record mode of a currently reproduced record medium as a first broadcasting mode, if not, judging as a second broadcasting mode, thereby obtaining exact reproduction.

Description

Automatic recording method for playback

1 is a block diagram of an apparatus for carrying out the present invention.

FIG. 2 is a flowchart of one embodiment of a recording method automatic discrimination method performed in the apparatus of FIG.

* Explanation of symbols for main parts of the drawings

10,20: 1st, 2nd amplifier circuit 30: system part

40: Servo part CA, CH: Capstan pickup head

A / C CH: Audio / Control Head

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording method automatic discriminating method in a recording and reproducing apparatus, and more particularly, to a method of automatically discriminating a recording method of a recording medium in order to set a performance mode of a servo unit in accordance with a method in which information is recorded during reproduction.

In general, the recording and reproducing apparatus records and reproduces video and audio signals. The video and sound information at the time of recording may be a signal reproduced by a recording / reproducing apparatus of the same type, a signal supplied from a video camera, or a signal transmitted from a broadcasting station. In particular, the signal transmitted from the broadcasting station has a different method for each country, and the servo unit is controlled to record according to the method. In other words, the TV system is developed by RCV in the United States, and used by the National Television System Committee (NTSC) system in Korea, the US, and Japan, and PAL (Phase Alternation, developed in Telefunken, West Germany, and used in the UK, West Germany, Australia, etc.). by Line (SEC) and Sequential Couleur A Me'moire (SECAM) method developed in France and used in France, Soviet Union and East Germany. These are different in the transmission method of the color difference signal and the multiplexing method of the color difference signal and the luminance signal, respectively. In particular, the PAL and NTSC methods differ in the recording surface when writing to tape. Both PAL and NTSC use the azimuth recording method, but in the case of the method, the 90 ° phase transition is filtered by one track, so one track is recorded as it is without changing the phase for each line, and the next track is phased for each line. Record by slowing down by °. NTSC, on the other hand, records a phase shift of 7 ° per matrix.

Therefore, when a recording medium recorded in the NTSC (or PAL) recording / reproducing apparatus set to the PAL (or NTSC) playback mode is inserted and reproduced, accurate reproduction is difficult. The reason for this is that when the recorded information is reproduced because the weft transition is different during recording as described above, the PAL is played back with the 90 ° phase shift (preceding) for the track that is not phase shifted, and the phase at the time of recording. This is because tracks with transitions are played back as they are, whereas NTSC plays with phase shifts for each track as in recording. Therefore, the user has to first recognize the method recorded on the recording medium and set the operation mode of the recording / playback apparatus according to the recorded broadcasting method. In addition, if the user does not recognize that the operation mode is not set properly, Normal playback signals cannot be viewed until the setting is set correctly. In addition, when the PAL and NTSC schemes are recorded on the same recording medium in order to reproduce them, there is a problem in that the operation mode of the recording / reproducing apparatus must be switched every time according to the broadcasting method of the recorded program.

Accordingly, an object of the present invention is to provide a recording method automatic discrimination method for automatically determining a recording method by detecting the number of control pulses generated from a recording medium based on a capstan frequency generator (FG) pulse during reproduction.

In order to achieve the above object, the present invention provides a recording and reproducing apparatus; A broadcast method automatic discrimination method of a recording / playback apparatus for recording and reproducing two or more video signals having different number of control pulses per unit time, wherein the number of control pulses per unit time reproduced while operating in the first broadcast method at the beginning of the playback operation of the recording / playback apparatus Counting and comparing the count value with a predetermined value within the setting range of the control pulse number per unit time of the first broadcasting method, and if it belongs, determining the recording method of the currently reproduced recording medium as the first broadcasting method. If it does not belong to the second broadcast method is characterized in that the process was made.

Next, the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of an apparatus for carrying out the present invention. In the apparatus for recording and reproducing a composite video signal and an audio signal, the pickup of the FG pulses of the capstan motor and the control of the recording medium are generally performed according to the rotation of the capstan motor. This is for controlling the operation mode of the servo unit in accordance with the pickup of the control signal in the signal recording area and belonging to the reproduction circuit.

Thus, the configuration of FIG. 1 includes a capstan pick-up head CA CH, a first amplifier circuit 10 for amplifying and outputting an electric signal read out from the capstan pick-up head CA CH by a predetermined value, and an audio / control head. (A / C CH), a second amplifier circuit 20 for amplifying and outputting an electric signal read out from the audio / control head (A / C CH) by a predetermined value, the first amplifier circuit 10 and the first amplifier The system control unit 30 receives the output signal of the two amplifier circuits 20 through each input terminal, and the servo unit for controlling the reproduction mode of the recording / playback apparatus in accordance with the output signal of the input terminal in the system controller 30. It consists of 40.

2 is a flowchart of one embodiment of a recording method automatic discrimination method performed in the apparatus of FIG. 1, wherein step 101 is a process of checking whether the current device is in a PLAY mode, and steps 102 to 105 are performed with FG pulses of a capstan motor. The control pulse number of the recording medium is up counted, and steps 106 to 108 are for comparing the up counting result value with a predetermined comparison value stored in advance, and steps 109 and 101 are for the servo unit 40 according to the comparison result. This is the operation mode setting process of.

The operation will then be described in conjunction with FIG. 1 and FIG.

Firstly, the capstan motor is for controlling the traveling speed and phase of the recording medium (ie, the magnetic recording tape) according to the operation mode as is known. Travel speed and phase control are achieved by FG and PG pulses generated from the capstan motor. FG pulses are for controlling travel speed and PG pulses are for controlling phase. Here is an example of automatically determining the recording method using FG pulses.

In addition, it is assumed that the recording and reproducing apparatus of FIG. 1 records and reproduces a composite video signal and an audio signal by PAL and NTSC broadcasting. At this time, the conditions of FG pulse and CTL pulse according to the tape speed of PAL and NTSC are shown in Table 1 (A) (B). Table 1 (A) shows NTSC and Table 1 (B) shows PAL.

TABLE 1

The interrelationship between A and B, the number of FG pulses of the capstan motor in Table 1, is expressed as follows.

According to Equation (1), the number of CTL pulses of PAL based on the CFG signal of NTSC in [Table 1] (B) is obtained. Therefore, the FG pulse of the capstan motor, which is a reference when determining the recorded broadcasting method, is the FG pulse of NTSC.

When the recording method automatic discrimination mode control signal is applied to the system control unit 30 by the condition setting as described above, it is checked whether the current recording / playback apparatus is performing the playback mode. At this time, whether or not the play mode is performed includes all the cases in which the play mode is continuously executed before the play mode is set or the auto discrimination mode control signal is applied. Through a key input unit (not illustrated) which is a means for applying information. The system controller 30 controls all functions of the recording / playback apparatus.

When the system control unit 30 determines that the PLAY mode is not performed, this mode is not performed even if the automatic discrimination mode control signal is applied. On the other hand, in the playback mode, the counter register (not illustrated) counts the number of FG pulses read by the capstan pick-up head (CA CH) and the audio control head (A / C CH). The counter registers (not shown in the figure) which count the number of CTL pulses to be read are simultaneously reset (step 102). The two counter registers are then set in the upcounting mode and read from the CA and A / C channels, respectively, and one pulse is applied to each input of the system controller 30 via the first and second amplifier circuits 10 and 20, respectively. Up counting is performed every time (step 103). Up counting is continued until A, the CFG pulse number of NTSC set as the reference value, is counted as described above. Here, the period during which the CFG pulse counting value becomes A corresponds to about 1 frame based on NTSC. When the counting value of the CFG pulses reaches A (step 104), it is temporarily stored in a predetermined memory register (not illustrated) to hold the counted CTL pulse number B (step 105). Then, the comparison value previously stored in the memory circuit in the system control unit 30 is read. First, 80 information is read to see whether the number of held CTL pulses is NTSC or PAL. If B is larger than 80, it is judged that the playback signal is generated at the tape speed of NTSC's SLP (Standard Long Play) speed as shown in (A) of Table 1, and the PAL / NTSC setting mode input terminal of the servo unit 40 Outputs a low logic level signal to set the NTSC mode. However, if B is less than 80 in step 106, 33 is compared with the next comparison value. If B is less than 33, the reproduction signal is generated at the SP tape speed of NTSC. Therefore, the low logic level signal is output to the servo unit 40 as described above.

If B is greater than 33 in step 107, as in step 108, 50 information is read at the minimum value and 65 information is read at the maximum value to check whether B exists therebetween. If present in between, since a reproduction signal is generated at the LP (Long Play) speed of NTSC, a low logic level is applied to the servo unit 40. On the other hand, if it is not present between the minimum value of 50 and the maximum value of 65, the high logic level is output to the PAL / NTSC setting mode input terminal of the servo unit 40 by determining the SP or LP speed of the PAL method. The servo unit 40 controls each motor to perform regeneration according to PAL and NTSC according to a control signal of the system controller 30 applied to the PAL / NTSC setting mode input terminal.

As described above, the present invention relates to the number of control pulses generated in the control signal region of a recording medium for a predetermined period in the apparatus for recording and reproducing video and audio signals of at least one broadcasting method. Accordingly, there is an advantage in that accurate reproduction is performed by automatically determining the recorded broadcast method to control recording and playback according to the recording method, and there is an advantage in that the reproduction control of the broadcast method of the recorded information is easy.

Claims (5)

A broadcast method automatic discrimination method of a recording / playback apparatus for recording and reproducing two or more video signals having different number of control pulses per unit time, wherein the number of control pulses per unit time reproduced while operating in the first broadcast method at the beginning of the playback operation of the recording / playback apparatus Counting; And comparing the count value with a predetermined value to determine whether the count value falls within the set range of the control pulse number per unit time of the first broadcast method. If the count value belongs, the recording method of the currently reproduced recording medium is determined as the first broadcast method. Automatic recording method of the recording method, characterized in that the process consisting of the second broadcast method. The method according to claim 1, wherein the number of control pulses per unit time is the number of control pulses per frame time. 3. The recording method automatic discrimination method according to claim 2, wherein the one frame period is set by counting the number of pulses of the frequency generator for detecting the rotational speed of the capstan motor. The recording method automatic discrimination method according to claim 2, wherein the first broadcast method is an NTSC method and the second broadcast method is a PAL method. 5. The recording method automatic discrimination method according to claim 4, wherein the setting range is a range of the number of remaining control pulses except a predetermined range between the SP and LP modes of the NTSC system and between the LP and SLP modes.