JPS601663A - Address signal system - Google Patents

Abstract

PURPOSE:To reduce the bit rate and to simplify a code detecting part and to lower the cost by recording a frame pulse per frame and recording intermittently the time codes every plural frames. CONSTITUTION:When a start pulse is supplied to a code generator, a signal combined with a time code pulse inserted between frame pulses. For this combined signal, frame pulses FP1-FP8 steplike rise then gradually fall as a sawtooth wave. While time code pulses TP1-TP7 are equal to a sawtooth wave which gradually rises and steplike falls. It is defined that the pulses FP1-FP8 produce a pulse per frame, and the pulses TP1-TP7 produce a pulse for each specific frame. Such a record signal is reproduced by a winding type magnetic head, and this output is equal to a differential output, so that the positive and negative polarity pulses are obtained and can be easily separated from each other.

Description

[Detailed Description of the Invention] [Field to which the invention pertains] The present invention records a time code indicating elapsed recording time as an absolute address on a recording/reproducing medium such as a magnetic tape for editing or information retrieval. , relates to an address signaling system for reproduction.

[Technical background of the invention]

In a VTR for TV broadcasting, a signal indicating an atto pulse is sometimes recorded on a magnetic tape and used as control information for editing, searching, etc. In the broadcasting industry, the SMPTE Quimcoat established by the American Society of Motion Picture and Television Engineers (SM)) Ding E (Motion Picture and Television Engineers Society) is often used as this address signal. First, s
The MPTE Thai J Code will be briefly explained.

Generally, video signals are recorded on a magnetic tape as diagonal trunks, and two trunks form one frame. An absolute address (address signal) is given to each frame, but
This absolute address is encoded into the audio track and controller 1-
Recorded on an auxiliary track (cue trunk) parallel to the roll track. S M P used in this case
One frame of "FE call 1" is 80 bits, 32 bits of these 80 bits are time code 1 which indicates the running time of the magnetic tape, 32 bits are empty hits for the user, and 16 bits are the sync word. It is said that

The 32-bit time code is composed of a frame code, a second code]-', a minute code, and an hour code, and is designed to indicate what hour, minute, and second frame it is.

As mentioned above, in the SMPTE code, 1 frame has 80 bits and time code 1" is recorded for each frame, so the recording density is high and errors are likely to occur when searching at high speed. Therefore, code detection accuracy is improved. The detection circuit becomes complicated and expensive.Furthermore, the hit rate is 2.4 Kbit/sec at the replay speed of a lightning strike, but it increases to 240 to 480 Kbit/sec during high-speed retrieval, so a detection head with good high-frequency characteristics is required. As it becomes necessary,
There is a problem in applying this SMPTE code to low-priced consumer ■1R and audio PCM recorders.

[Purpose of the invention]

The present invention records one frame pulse for one frame, and records the time code intermittently every several frames, for example, every few seconds, thereby reducing the pulse rate and making the code detection unit simple and inexpensive. The purpose is to

[Summary of the invention]

Frame pulse for each frame and N frames (N
is a positive integer (for example, 30), the time code of the intermittent address time is recorded on the magnetic tape, and during playback, the time code of the intermittent address time is recorded on the magnetic tape.
, demodulates the code to obtain the intermittent address time, counts the frame pulses, and adds this 1-number to the address time to obtain a continuous address time; The feature is that the count number is used as the frame number.

[Embodiments of the invention]

FIG. 1 is a block diagram of an embodiment of an address signal recording and reproducing apparatus for recording and reproducing address signals according to the present invention, in which 1 is a code generator that generates a combination signal of a frame pulse and a tie J code; 2 1 is an amplifier for amplifying the output signal of the generator; 3 is a changeover switch for recording mode and playback mode 1; 4 is a recording and playback button I;
5 is a magnetic tape, 6 is a separation circuit that separates the reproduced pulse into a frame pulse and a time code, and 7 is a time code into a decimal address time.ii 1! 8 is a 30-decimal counter that counts frame pulses and obtains an output in units of seconds, and a decoder that converts the frame pulses into a decimal number.

Next, the operation of the address signal recording/reproducing circuit shown in FIG. 1 will be explained.

Code 8'Ik1 has frame pulse and start pulse input terminals F and S, and when a start pulse is input manually, code generator 1 generates a frame pulse and a time code pulse inserted between the frame pulses. What is output when combined with

This combined signal is recorded so that it can be easily separated during playback. Figure 2 (al is an example of the recording double angle, the sawtooth waves from FPI to FP8 are frame pulses, and the reverse sawtooth waves from 1'P1 to 'rP7 are time code pulses. F P8 is a sawtooth wave that rises in steps and falls gradually, and time coat pulses TPI to TP7 are sawtooth waves that rise gradually and fall in steps.Frame pulses FPI to FP
8 is designed to generate pulses of 1 + [lil per frame J, and are generated continuously and sequentially. Time coat pulses TPI to TP7 are generated every specific number of frames, are signals synchronized with frame pulses, and correspond to code 1-' to be recorded. For example, when the code is “1pa”, a pulse exists at the pulse position of that call “1”, and “0”
It is arranged so that it does not exist at the time of . (In this example, there is no sawtooth wave corresponding to TP3 and 1゛P6, and 1゛P3 and 1゛P6 are O. That is, the time coat pulse TP ] to 1゛P7 is 1101101.) Like this When a recorded signal is reproduced by a W-type 1-wire magnetic head, the output is a differential output, so the frame pulse is a positive polarity pulse and the time coat is a negative polarity pulse. (because it is obtained)
− allows easy separation. Address signals of the present invention that are combined in this manner will be described.

According to the conventional TV system, the frame pulse is 30 per second.
Since frames are recorded, the frame pulse interval is 1/30th of a second, and the QuiJO code is recorded every 10 seconds. First, when a star 1-pulse is input from the input terminal S, the first frame pulse input from the input terminal F immediately after is inserted between the first and second frame pulses as a reference time. Two word-pulses are generated as follows. This word pulse is used to determine the following pulse as the MSB of the time code, and is also used as a reset pulse for a counter, which will be described later. The time code consists of 5 bits, and the frame J
One bit is inserted into one section of the new pulse. Therefore 2~
A time code is inserted between the seventh frame pulses.

Since the minute code consists of 6 bits, the minute code is inserted between the 7th to 13th frame pulses. The second code is 3
A seconds code 1'' is inserted between the 13th to 163rd to 16th pulses.The seconds code is a coded value of the tens place of seconds.

FIG. 3 diagrammatically shows the relationship between the above-mentioned frame pulse FPn and time code.

The first time coat 00:00:00 is recorded, and the time occupied by this time code and word pulse is approximately 0.5 seconds since they are the 1st to 16th frame pulses.

The next time code is recorded at 00:00:00:00:10, so two word pulses are inserted between the 301st and 302nd frame pulses, the time code is from 302nd to 30th, and the minute code is from 307th to 30th. 313th, second code is 3
Inserted from 13th to 316th.

Thereafter, time code and word synchronization pulses are generated every 10 seconds in the same way, and are amplified by amplifier 2 and output to head 4.
The magnetic tape 5 is supplied to the magnetic tape 5 and recorded on the key: +--1- rank.

Figure 4 shows a pulse signal consisting of a frame pulse FPn and a time code TPn output from head 4 during playback, and the figure shows 2 hours 35 minutes 30 seconds (10・100011・011).
Illustrated as an example. (0 is omitted for 30 seconds and only 3 is coded) Record the recording/playback mode switching switch 3 #P! IIIJ
When switching from 3a to the reproduction side 3b and leading the output of the head 4 to a separation circuit 6, the separation circuit 6 is composed of, for example, a diode and separates it into positive polarity pulses and negative polarity pulses.

If there is a reproducing means for the head 4 as shown in Figure 4, the frame pulse, which is a positive polarity pulse, is sent to a non-counter 8, and the time code F, which is a negative polarity pulse, is sent to a time code decoder 7, where they are separated by a separation circuit 6. is input.

If the 279901st frame pulse is defined as the 1st frame pulse, the following negative pulses are detected as word synchronization pulses by the time code decoder 7 because there are two negative pulses in one period of the frame pulse. The time code decoder 7 resets the contents of the decoder 71 by these two word pulses and outputs a reset signal to the counter 8 to reset the counter 8 to the initial state.

This is necessary when playing from the middle of a magnetic tape.

The frame pulse FPn is counted by the counter 8, and at the same time the contents of the counter are changed to 10 by the decimal decoder.
Converts to a base number and outputs the frame number.

Immediately before the 16th frame pulse, the time code is completely reproduced and demodulated by the time code decoder to output an address time of 2 hours, 35 minutes, and 30 seconds. counter 8
When the counter 8 counts 30 frame pulses, one pulse is sent from the counter 8 to the time code 1 decoder and added to the seconds digit, and 2 hours 35 minutes 31 seconds is output from the time code F decoder.

Thereafter, output is performed in the same manner until 2 hours, 35 minutes, and 39 seconds.

Next, since the beam synchronization pulse is detected, the time code decoder 7 and counter 8 are reset, and the following time code outputs 2 hours, 35 minutes, and 40 seconds.

As described above, the address tie can be obtained in seconds using the time coat recorded every 10 seconds and the frame pulse.

Note that if a control trunk is provided, the control pulse can also be a frame pulse.

In Figure 5, time access codes 1~ are recorded every 5 seconds, and program number code 1 created at the same cycle as the frame pulse is inserted in the frame pulse part of 211ffl+a+. This is an application example of VTR random access for the purpose of setting the J1 recording order and accessing an arbitrary program. Figure 5 (al is block 1', 1 block configuration diagram, 1 program block is set to 5 seconds, and at the beginning, TAn, T, respectively.
A time address code similar to that shown in Fig. 2 is added, followed by a program number code PNm, the purpose of which will be explained later.

Therefore, ■If the block time is set to 5 seconds (15 () frames), the time address code TAn will be 1 word with 14 hints, and if t'Nm is 8 pino], then 17 words will be inserted to make 1 block. . FIG. 5 (bl indicates the time address code T^, and the second code is recorded every 5 seconds, so it is encoded with 4 bits. The least significant bit is the 5 second digit.

Since minutes are generally used to represent recording time on tape, the minute code is 8 bits and has a maximum of 225 minutes, and a 2-bit, 7-bit synchronization signal is attached to the indentation of the minute code as a block synchronization signal, so one word is 14 bits in total. Configure. Figure 5 (C1 shows the configuration of the program number code PNm, 6
It consists of a maximum of 63 program numbers using bits (for 6 frames), 1 bit for commercial skip marking, and 1 synchronization bit for a total of 8 bits.

The structure of the program number code PNm in Figure 5 tc>, the recording method, the reproduction signal extraction method, and the application to random access of VTRs are disclosed in Japanese Patent Application No. 57-171.
No. 754 has the same gist and is therefore omitted here.

As mentioned above, in the application example of FIG. 5, for example, the time address code TAn is set to 15 minutes and 5 seconds,
If +t is recorded as 15 minutes and 10 seconds, and the number code PNI11 is recorded in program number 3, minutes/seconds/seconds can be set in the same manner as shown in Figure 2 during playback, fast forward, and random access. Arene, present (q position e.g. 15
It is possible to output minutes, 10 seconds, and program number 3 in an authentic accent. If this is displayed at any time and the desired φ time address is set in advance, any program position can be accessed, and conversely, the absolute address of the desired program can be obtained from the display.

Also, since the program number code Nm is, for example, PNrn=3 continuously recorded during the same program,
When searching the head of the program, loading the wound tape at any position ζ also slightly runs the tape.
If you do so, you can quickly determine whether the target program is located before or after the destination address, and run. Furthermore, since the time address and program number are recorded closely, the location accuracy of access can be improved.

Incidentally, if the option bit is recorded as "1", for example, in an unnecessary part such as a commercial, and the playback is performed in fast forward mode during continuous playback, comfortable playback can be enjoyed even with air check sources. In the above explanation, we have used specific numbers such as the block configuration, word configuration, TA recording interval, etc., but this is not intended to be limiting.When recording this time code, information such as the cumulative time of the recorded section and the remaining time that represents the total length of the tape is used. 1. For example, the remaining amount may be notified by displaying the value calculated from a detection hole provided in the tape cap. Furthermore, this time code I does not only represent the elapsed time from the beginning of the magnetic tape at the time of recording, but may also represent data such as month, day, hour, minute, etc. at the time of recording, for example.

Furthermore, when recording an audio PCM signal, instead of frame pulses, block synchronization or the like can be used by dividing the frequency into the time required for access.

〔Effect of the invention〕

As described above, in the address signal system of the present invention, the address time can be recorded and reproduced using a coat with a low pip rate, so the code detection circuit and magnetic head can be made inexpensive, and it can be applied to low-cost VTRs and audio 1) CM recorders. Furthermore, since there is a part where no code is recorded, program numbers and other control information can be stored.

[Brief explanation of the drawing]

Figure 1 is a block diagram of one embodiment of the present invention, Figure 2 (a
L (bl is the recording waveform of the embodiment of the present invention and its reproduction 11
Form II, Figure 3 is a time chart 1 showing the relationship between frame pulses and time codes, Figure 4 is a time chart showing pulse signals during playback, Figure 5 ta+ is a word configuration diagram, Figure 5 (bl, ( C1 is a configuration diagram of a time address call l' and a program number code, respectively.■...Code generator 2...Amplifier 3...Selector switch 4...Y I'5...Magnetic tape 6.
...Separation circuit 7...Time code 1-decoder 8...
・Counter and decoder patent applicant Yoshiyuki Osuga, patent attorney representing Sansui Denki Co., Ltd.

Claims (8)

[Claims] (1) In a recording/reproducing device, a pulse related to the recording time of information is continuously recorded as a first signal on a recording medium,
Further, an address signal composed of pulses recorded within a plurality of the pulses is intermittently recorded as a second signal, and the reproduced output of the first signal is used as the reproduced output of the second signal during reproduction. An address signal method characterized in that a continuous address is obtained by counting from a starting point and adding the count output and the reproduced output of the second signal. (2) The address signal system according to claim 1, wherein the pulse related to the recording time of the information is a synchronization signal of each signal. (3) The address signal system according to claim 1, wherein the address signal composed of pulses recorded in a plurality of ellipses has intermittent recording elapsed time data. (4) The address signal system according to claim 2, characterized in that when the l1TJ iJJ pulse is TV frame synchronization, the count number is used as a frame number. (5) The address signal system according to claim 1, wherein the address signal has program number data representing the recording order of information in an intermittent space portion. (6) The address signal system according to claim 1, wherein the recording/reproducing device has automatic indexing means for automatically indexing the address signal. (7) The address signal includes a skipping signal, and the automatic indexing means detects the skipping signal and, in step 7, skips and reproduces the area in which the skipping signal is recorded. An address signaling system according to claim 1. (8) The address signal system according to claim 1, wherein the address signal and information representing the total length of the tape are calculated during recording of the address signal, and tape overtime is displayed.