JPS62120687A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To perform directly program searching in a high speed mode by using plural program searching signals. CONSTITUTION:Plural program searching signals with a fixed time band are formed with constant time intervals from a reference on a recording track, the existence of a signal in each program searching signal time band is treated as a digital signal and respective program addresses are digitally constituted to record a series of burst-like program searching signals. At the time of retrieval in a high speed mode, a signal is extracted in each program searching signal time band, so that the existence of a signal in each time band can be digitally discriminated to obtain each program address. Consequently, the program address on the tape can be directly read out in the high speed reproducing mode and the program searching can be quickly performed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic recording/reproducing device having a cueing function.

Prior Art When a plurality of programs are recorded on one magnetic tape, it is actually difficult to locate the beginning of the program. Below is 3F as the conventional technology! I will explain AJ, but all of them are in high speed mode (FF.

RIW), it was difficult to search directly and locate the beginning with certainty.

Conventional column 1 - the part before each program starts, records an address number (hereinafter referred to as address) indicating the order in which the program is recorded. In this column, addresses can be detected in playback mode where the tape runs at standard speed, but in high-speed mode, the address cannot be read accurately because the tape speed changes. Therefore, in order to accurately determine addresses, it is necessary to increase the reliability of address determination by controlling the traveling system so that the traveling speed remains constant even in high-speed mode.

Conventional Example 2 - A no-signal section is created at the boundary between programs. In this example, boundaries can be easily distinguished even in high-speed mode, so it is often used in, for example, audio tape recorders. However, although the border can be easily identified, the absolute address cannot be determined, so the address can be determined by rewinding the tape to the beginning and then counting while identifying the border in FF mode. can.

Conventional column 3 - A recording section of a specific frequency that can be easily read even in a no-signal section or high-speed mode is created in the section between programs, and then a signal indicating the address of the subsequent program is recorded.

When searching, first find the boundary in high-speed mode, then switch to standard speed mode (playback) to run the tape, read out the address information of the program, calculate the difference from the address you want to start, and then use high-speed mode ( FF or RI
CW), and as soon as the boundary is counted by the above-mentioned difference, the playback or stop mode is started, and the cueing is completed.

Cueing is performed by the method described above.

Problems to be Solved by the Invention However, each of the above-mentioned cueing techniques has drawbacks and is not always fully utilized in general. Hereinafter, the drawbacks and problems of each of the above conventional examples will be described.

Conventional row 1: The change in the running speed of the tape in the high speed mode is due to the change in the tape winding diameter υ, and the rotational speed of the reel stand for winding the tape is constant. In this conventional train, it is necessary to keep the tape running speed constant in high-speed mode, so the rotation speed of the reel stand must be controlled according to the tape winding diameter, which makes the control circuit complicated and costs high. It also becomes more expensive. Also, the original F
It is true that the tape running speed is somewhat slower than FRKW, so it takes more time to cue up.
Currently, it is hardly used.

Conventional column 2: When searching, it is first necessary to rewind to the beginning, and it takes too much time to find the beginning.

Conventional column 3: When searching, it takes time to switch from high-speed mode to playback mode and read the address signal. Furthermore, it is often necessary to insert two types of cue signals at the beginning of a program, and a sufficient boundary section between programs must be provided, resulting in a large loss of recording time.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a magnetic recording and reproducing apparatus that uses a plurality of cue signals that can be read even in high-speed mode, and allows direct cueing in high-speed mode.

Means for Solving the Problems In order to solve all of the above problems, the magnetic recording/reproducing apparatus of the present invention provides a magnetic recording/reproducing apparatus that uses a recording signal on the recording signal track instead of the video or audio recording signal in the boundary section between programs. Means for recording and reproducing a cue signal is provided, and the cue signal is made up of a set of cue signal time periods separated by a certain time interval, and the means All cue signals having program address information indicated by the presence or absence of cue signals are recorded, and the cue signals are reproduced separately for each time period in search playback mode.
The program address information is obtained by determining the presence or absence of a cue signal in each time period.

Function The present invention configures a plurality of cueing signals in a certain time period at certain fixed time intervals as a reference on the recording track, treats the presence or absence of the signal in each cueing signal time period as a digital signal, and calculates the program address. is given digitally, and a series of burst-like cueing signals are recorded, and when searching in high-speed mode, the presence or absence of a signal for each time period can be determined by extracting the signals for each time period of the cueing signal. , which can be determined completely digitally to obtain the program address.

Embodiment Hereinafter, a recording/reproducing apparatus according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 2 is a diagram showing the relationship between the head and tape of a magnetic recording/reproducing apparatus according to Embodiment 9+1 of the present invention. The head 1°2 is attached to a rotating cylinder 3 and is traveling as shown in the figure. Recording and reproduction are performed alternately on the tape 4. The word sequence for each head at that time is shown in FIG. The signals to be recorded and reproduced are video signals, audio signals, or both.

The cueing signal used in this embodiment uses a constant low frequency signal as a program boundary section signal.

This cueing signal uses a low frequency signal to minimize the azimuth effect caused by head 1.2 in order to obtain a playback output with a certain level even in high-speed mode, and the signal can be detected even in reverse azimuth. That's what I do. However, the lower the frequency, the smaller the azimuth loss, but the playback output of the head is about 10
Since the frequency decreases rapidly from around 0KH2 to below 0KH2, the cueing signal frequency is set at about 200KH2. The above frequencies are also frequencies that do not affect video signals, audio signals, or other signals.

FIG. 1 is a block diagram of the recording circuit. The video/audio recording signal processing circuit 5 processes input signals such as video input and audio input, and outputs recording signals.

When a normal program is being recorded, the video/audio recording signal passes through the recording signal changeover switch 6, passes through the head changeover switch 7 to heads 1 and 2, is amplified by the recording amplifier 24, and is output to the recording/playback changeover switch 25. The flow is recorded to head 1.2. Record/playback switch? The switch is turned on/off by a recording/reproduction switching signal outputted from the system control circuit 11. The program address number is set by the bushing switch 12 and displayed by the display circuit 13 via the system control circuit 11. Each time the button switch 12 is pressed, the address number is incremented by one.

The input address number is converted into a 5-bit digital signal and sent to the cue signal switching pulse generation circuit 10. The digital signal indicating this 6-bit address number is 2 degrees for the 1st bit, 21 for the 2nd bit, 22 for the 3rd bit, 22 for the 3rd bit, 25 for the 4th bit, and 24 for the 5th bit. When written in order from the 1st bit, it becomes "100oO", and the address "10" is "01010".
, address "3o" becomes "01111".

Next, the cueing signal switching pulse generation circuit 10
With the block configuration shown in the figure, each time period of the cue signal is set using mono multivibrators (hereinafter referred to as MM) 14 to 22 based on a head switching signal that alternately switches the recording signal to the head. It is set. First, the 140MM sets the 1st bit cue signal recording time period, the 15th MM sets the time at the boundary between the 1st bit and the 2nd bit, and then sequentially sets the time period for each pit. and set the interval. FIG. 6 shows the output timing of each MM. The output of MMl4 is the recording time period of the 1st bit, MMl6 is the 2nd bit, MMlB
is the 3rd bit, MM20 is the 4th bit, and MM22 is the 6th bit.

Returning again to the block diagram of the cue signal switching pulse generation circuit shown in FIG. 4, the explanation will be given again. Depending on the 6-bit address number data inputted from the system control circuit 11, the recording time pulse of each bit outputted from the MM is turned on/off using the switch 23i. Data "1"
'', the switch is connected and the recording time pulse is transmitted. The recording time pulses turned on/off by the 5-bit address data are collected in the OR circuit 28, and its output is a cue signal switching pulse, which determines the cue signal recording time zone of each bit in the time axis direction. The high/low (H/L') signal at that level becomes a series of pulse trains with address information.

Referring again to FIG. 1, in response to the cue signal switching pulse output from the cue signal switching pulse generation circuit 1o as described above, the cue signal is changed to the H level of the switching pulse by the cue signal changeover switch 9. It is turned on at the L level and turned off at the L level. Therefore, the cueing signal outputted from the cueing signal changeover switch 9 is a burst-like signal divided according to each set recording time period, and the cueing signal is divided according to the presence or absence of a cueing signal burst in each time period. This results in a signal having program address information. Then, the above-mentioned cue signal is connected to the recording signal changeover switch 6 in place of the video/audio recording signal by a switching signal outputted from the system control circuit 11 when entering the program boundary section, and is alternately recorded by the head changeover switch 7. Amplifier 24. The signal is sent to the head through the recording/reproduction changeover switch 26 and recorded.

FIG. 6 shows the timing at which the cue signal is recorded. The respective cue signal recording time periods for the head switching signals H and +H2 are co l c, + 02 + 03+
Assume that the settings are as shown in C4. Note that when the head switching signal is at H level, head 1 is selected, and when the head switching signal is at L level, head 2 is selected.
The recording signal is connected to. For example, program address "1"
In this case, only the first bit pulse is H, and a burst cue signal is output at the Go timing and becomes a recording signal to the head. For address "10", only the 2nd and 4th bit pulses are H, C,
, C3, the cue signal is recorded. street address"
21” for 1. Switching is performed with a pulse in which the 3rd and 5th bits become H, and a cue signal is recorded at the timing of 001 C2104.

Next, the state of the cue signal recorded on the tape is illustrated in FIG. Recording and playback are performed from right to left over time in the tape running direction.
'' are recorded, and if the track ends at track number 7, a cue signal is immediately recorded. This cue signal is the next program address r23J'!
In the example shown in the figure, if the signal has a cue signal burst at the 1st, 2nd, and 3.5th bits, the head moves from the top to the bottom of the diagram, so the timing GO+ on tracks 8, 9, etc.
Recording is performed with CI H"2 + "4, resulting in a pattern as shown in the figure in which cue signal bursts exist in the shaded areas. After the cue signal is recorded for 3 seconds, the contents of program address "23" are recorded on track number 188. In other words, the cue signal was recorded in 180 fields for 3 seconds. Similarly, program address "23"
” and the boundary between the contents of “24” and the address r 2.
The cue signal shown in 4j' (timing 0., C4
) are recorded. cue signal 3
The reason for recording for seconds is to enable the cueing signal to be read out at least once even if the search is performed in a high-speed mode that is up to 180 times faster than the standard running speed.

Next, a block diagram of the reproducing circuit is shown in Fig. 8.9.10.

First, in FIG. 8, during normal program playback, the playback head signal is from head 1. The respective playback head signals are obtained alternately with the head 2, pass through the recording/playback changeover switch 25, are amplified by the head amplifier 26, and are output by the playback head signal switching signal outputted from the cue signal discrimination control circuit 30. The reproduction head signal switching circuit 29 sends a series of reproduction signals to the video and audio reproduction signal processing circuit 31, where the signals are processed and then output as video and audio through the muting circuit 32.

The band pass filter (hereinafter abbreviated as BPF) 33 is a filter that passes only the frequency band of the cue signal.
During normal program playback, nothing is output from the BPF 33. The center frequency of BPF33 is approximately 200 KHz
The BPF band is set to 14 to accommodate changes in the cue signal caused by changes in the relative speed of the tape and head due to FF and FtEW high-speed modes.
Set from 0 to 280KH2.

When playing the cue signal in high-speed mode, BPF3
The cueing signal that has passed through 3 is separated by switches 34 to 38 for each time period. The timing of separation is
As shown in FIG. 10, each time odd extraction has a circuit configuration in which MMs similar to those in FIG. It is generated by the pulse generation circuit 27. FIG. 11 shows the timing of the extraction pulses for each time period. Playback head signal switching signal h1
+ Cue signal recording time period pOTpal based on h2
When set as p2+ p3+ p4, the extraction pulses for each cue signal time period are as shown in the figure. This extraction pulse is characterized in that its pulse width is set narrowly across the recording time period.

This is because when searching in high-speed mode, the running system does not have enough tension, so the tape shifts slightly and comes into contact with the head, so the time periods of the cue signals may vary slightly during playback. This is to prevent the playback cue signal from leaking into another time zone at that time. Furthermore, it is possible to prevent leakage into other time zones due to the band widening when passing through BPFi.

To explain FIG. 8 again, each cue signal separated for each time period is rectified by a rectifier circuit 39 and integrated by an integrator circuit 40 to form a waveform.
You will have a C level.

The comparator 41 compares it with the lowest level of the playback cue signal, and outputs a cue signal integrated waveform whose level is higher than that level, with only the higher portion held at the H level (cue cue signal comparator output). is obtained.

Next, in FIG. 9, a 5-bit digitized playback cue signal (the cue signal comparison output) is input to a clip-flop circuit 42, where the cue signal is separated for each time period and is divided into different times.

The falling edge of the band extraction pulse is latched at the edge, and the presence or absence of the cue signal for each time period is held as a high/low level of a digital signal. When the output of the flip-flop circuit 42 is at H level, that is, when there is a cue signal during the cue signal time period, the switch 43 is turned off at the H level to stop the subsequent extraction pulses, and the output of the flip-flop circuit 42 is hold el. The reason why each bit of the cue signal time period pulse is cut off separately by the switch 43 is that if for some reason only one cue signal time period is not reproduced where the cue signal should be, the next Since the signal is reproduced by the head on the opposite side of the signal, it is necessary to separate the pulses for extracting the signal time period for each bit. Also, since the cue signal is recorded for 3 seconds and 180 fields, even in high-speed mode, when the driving speed is slow, the cue signal will be played several times, and these will be considered as one cue signal. This is because the signal at H level must be maintained during the time period in which the cue signal was present until the cue signal is no longer reproduced.

Next, when any of the outputs of the flip-flops 42 becomes H level, the OR circuit 44 determines that reproduction of the cue signal section has started and sends an H level signal fMM46. MM45
completely plays the cue signal section.

The time it takes to finish, here about 0.4 seconds, the output iH
hold at level. In other words, the maximum time for reproducing a 3-second section of the cue signal recorded during a search in high-speed mode is when the high-speed speed is the minimum, and if this minimum speed is 1Q times the standard speed, it is 0.3 seconds. Therefore, this holding time is set to about 0.4 seconds. The falling edge of the output signal from H level to L level is L.
i- is used to clock the flip-flop 46 and transfer the data of the cue signal being played back to the flip-flop 46.
The output is held until the next cue signal comes. Further, when the output of the MM 45 falls at p, the flip-flop 42 is reset, all of its outputs are set to L level, and the clock continues searching until the next cue signal is detected.

The output of the flip-flop 46 is a discrimination cue signal for each bit, and these are input to the cue signal discrimination control circuit 3o.

In FIG. 10, the operation of the cue signal judgment control circuit 30 will be mainly explained. First, when the program address to be cued is entered into the search address input keyboard 48, the data is sent to the address signal digitization circuit 47, where it is converted into a digital signal similar to the cue signal, and then sent to the cue signal discrimination control circuit 3o. is input. The display circuit 49 inputs the address to which the vehicle is to cue and the address at which the vehicle is currently running through the cue signal discrimination control circuit and displays them. When the search button on the search address input keyboard 48 is pressed, the cue signal discrimination control circuit 30 first outputs an FF or REV signal to run the tape at high speed in order to know the program address currently being run, and the first detected program address is detected. Input all cue signal data. Thereafter, the current address and the address to be searched are compared, and if the address desired to be searched is larger, an FF signal is output, and if it is smaller, a REV signal is output, and a search in high speed mode is started.

Then, the address data of the playback cueing signal and the address to be cued are compared bit by bit, and if they match, a playback or stop signal is immediately output to complete cueing. In addition, the cueing signal discrimination control circuit 3o outputs an image when the cueing signal is played back.

It outputs a muting signal for muting the output of the audio signal, and also outputs a playback head signal switching signal. Next, for reproduction of cue signals in modes other than high-speed mode, signal processing similar to that described above may be performed. Mk4 depending on the time to play the section of the cue signal that is recorded for just 3 seconds.
It is necessary to set the time of 5.

The timing showing the detection of the cue signal will be explained with reference to FIG. The reproduction head signal switching signal 1, h2 indicates that head 1 is selected at H level and head 2 is selected at L level. For this playback head signal switching signal, h2, the recording cue signal time period T'D + pi + P2
+ ps + p4 is set. If the BPF33 is manually operated, the time zone will be slightly expanded by the output of the BPF33, which will be a series of cue signals as shown in the figure. If we look at the cue signal for the 1st bit (timing p) below, we will see that the 1st bit is switched and extracted by the 1st focus extraction signal.
The cue signal for only the bit is rectified and integrated, and is made into the output fH level of the comparator circuit 41. and 1
The output of the flip-flop 42, which is clocked by the bit selection pulse, does not go to the H level at the timing shown in the figure, and the clock input to the flip-flop 42 is thereafter cut off and remains at the L level. The same operation is performed for the 2nd to 5th bits. Next, the timing of the playback cue signal, which is a digital signal, will be fully explained using FIG. If the cueing signal to be reproduced is the cueing signal illustrated in FIG. 12, the cueing signals are at the 1st bit and the 3.4th bit, so "13" is shown as the address number.

As shown in the figure, when the reproduction head signal switching signals h1 and h2 are set, the first clock (GK) input of the flip-flop 42 outputs H and L signals to the same output, respectively. The input clock of the 7-lip frontop 42 for the 1st and 3.4th bits, which output the H level, is then cut off, and the MM46 output (0, After the output of the flip-flop 45 is latched and held, the output of the flip-flop 46 is reset to L level. The sampling signal is input, and the next cueing signal can be detected at any time. As described above, the playback cue signal data "1011o" is sent to the cue signal discrimination control circuit.

Effects of the Invention As described above, according to the present invention, program addresses on a tape can be directly read in high-speed playback mode.
The excellent effect of being able to quickly locate the beginning of a program can be obtained.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a recording circuit according to an embodiment of the present invention, and FIG. 2 is a top view showing the relationship between the head and tape of this embodiment.
Fig. 3 is a signal configuration diagram, Fig. 4 is a block diagram of a cue signal switching pulse generation circuit, and Fig. 6 is a block diagram of each MM in Fig. 4.
FIG. 6 is a timing diagram for recording the cue signal of this embodiment; FIG. 7 is a tape pattern diagram showing the state of the cue signal recorded on the tape; FIGS. 8 and 9;
Figures 10 and 11 are block diagrams of the main parts of the reproducing circuit, respectively.
The figure shows the cue signal extraction pulse timing diagram for each time period.
FIG. 12 is a timing diagram showing the detection of the cue signal;
FIG. 3 is a timing diagram of the playback cue signal which has become a digital signal. 1...Head, 2...Head, 3...
... shilling, 4 ... tape, 5 ...
・Video/audio recording signal processing circuit, 6...Recording signal changeover switch, End...Head changeover switch, 8.
...Cueing signal generation circuit, 9... Cueing signal changeover switch, 10... Cueing signal Swiftinckhals generation circuit, 11... System control circuit, 12...°゛Program address input switch, 13...Program address display circuit, 14゜1
(3, 18, 20, 22-=-・bit time zone setting MM
, 15.17, 19.21... Bit interval setting M
M. 23...Bit switching pulse ON10
F F switch, 28...OR circuit, 29
......Playback head signal selection switch, 3o...
...Cutting signal discrimination control circuit, 31...
...Video and audio reproduction signal processing circuit, 32...Muting circuit, 33...BPF. 34.35, 36, 37.38...Each pit playback signal extraction switch, 39...Rectifier circuit, 4Q...Integrator circuit, 41... Comparator, 42...Flip-flop circuit, 4
3...--Clock pulse on/off switch, 4
4...OR circuit, 45...MM, 46
...Flip-flop circuit, 47...
Address signal digitization circuit, 4a... Search address input key port, 49... Display circuit, 5°...
... Pulse generation circuit for each time extraction. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Fig. 2 Fig. 3C2I Fig. 4 Zui V Nan 7'/Y/L;A Fig. 5 Ht Fig. 6 Fig. 8 Fig. 9 Fig. 10
``(1 小 hi 2 く gu yaka (do 44 ri 1 number 11 figure 12

Claims (1)

[Claims] A means is provided for recording and reproducing a cue signal on the recording signal track in place of a video or audio recording signal in a boundary section between programs, and the cue signal is divided at a specific time interval. The means includes a set of cue signals within a plurality of cue signal time periods, and the means records a cue signal having program address information indicated by the presence or absence of a cue signal in each time period, and detects playback. A magnetic recording/reproducing apparatus characterized in that the program address information is obtained by reading out the cueing signal in the above mode and determining the presence or absence of the signal in each cueing signal time period.