JPS61134978A - Magnetic tape reproducing device - Google Patents

Abstract

PURPOSE:To greatly improve the program searching speed of a magnetic tape reproducing device as compared with conventional program searching operations by a counting system, by making the program searching possible by reading address information which is absolute addresses. CONSTITUTION:When a music selection starting button 33 is operated, a quick rewinding mode is set and a tape 10 is rewound and address information 4B is read by a signal detecting section 36 at the position (2) immediately after the rewinding of the tape 10. The address information 4B (=m) is compared with an address number (=No.n) at a comparator 39. When m>n, the quick rewinding mode is continued and, when m<n, the quick rewinding mode is stopped a the position (3) and a quick forwarding mode (4) is set. At the posi tion (5) in the course of the quick forwarding mode, address information 4C is read and the address information 4C is given to the comparator 39 in accor dance with the above-mentioned operations. In such a way, address information is successively read and, when m=n, a motor 37 is stopped at the position (7).

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a magnetic tape reproducing device that can quickly and easily locate the beginning of arbitrary information recorded at different positions on a magnetic tape.

(Prior Art) In general, magnetic tapes have difficulty in comparatively random access to recording media such as disks. Therefore, magnetic tape playback devices usually perform cueing by high-speed forwarding.

Conventionally, in magnetic tape playback devices, aluminum foil is attached to the magnetic tape, for example, an audio tape, or a pilot signal is recorded.The playback device calculates the desired tape position by counting this from the beginning of the tape during high-speed feeding. Automatic cueing is performed so that it can be detected and played.

(Problems to be Solved by the Invention) However, in the conventional reproducing apparatus of this type, since aluminum foil or the like is used for the magnetic tape, there are problems in that the tape is difficult to manufacture, leading to increased cost and poor running performance. Furthermore, since predetermined positional information is counted and detected from the beginning of the tape, high-speed cueing cannot be performed, and reliability is poor, such as being prone to malfunctions.

Furthermore, it is difficult to apply conventional techniques to a magnetic tape reproducing apparatus that reproduces video tapes or the like using a helical scan method.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention is applied to a magnetic tape playback device that requires particularly high-speed and accurate automatic cueing, and its main components are as follows. As shown in FIG. 1 (block circuit diagram of main parts), the operation section 31 is provided for selectively inputting a plurality of address numbers n, and the address number n recorded at a plurality of different positions on the magnetic tape 10 during tape feeding is provided. The address information m corresponding to the magnetic tape 10 is reproduced, and when the address number n preselected by the user matches the value of the reproduced address information m, tape feeding is stopped and the beginning of the magnetic tape 10 can be found. It is characterized by

(effect) Next, the operation of the present invention will be explained.

Since the address information m is recorded as an absolute address on the magnetic tape 10, the apparatus can detect the position of the tape by directly reading this. Therefore, by rewinding the magnetic recording tape 10 at an arbitrary tape position and reading the address information m immediately after, the feeding direction of the tape 10 can be determined in relation to the address number n at the preselected target position. . Further, when the tape is fed (at high speed), a non-recording section provided on the tape 10 side, for example, detects that it is an address information recording area, and the target address information is directly read to locate the beginning of the tape position.

(Example) Below, preferred examples according to the present invention will be described in detail with reference to the drawings.

First, the recording pattern of the magnetic tape used in the magnetic tape reproducing apparatus according to the present invention will be explained with reference to FIGS. 3 and 4. 3 and 4 are track pattern diagrams of the same tape.

FIG. 3 shows an example of a videotape, particularly a tape (so-called video karaoke tape) on which accompaniment music, image images, etc. are recorded as information to be recorded.

The video tape 10 shown in the figure has audio tracks lla and llb with 2 channels of upper and lower needles arranged at the top, and in the middle of the tape 10, a large number of inclined video trunks 12a are reproduced by a rotating head using a helical scan method.
, 12b, 12c... are arranged. Further, a control track 13 is arranged at the bottom of the tape 10. In each of the above tracks, audio tracks lla, ll
Audio signals are recorded in the audio signals b, video signals corresponding to one field are recorded in the video tracks 12a, and furthermore, control signals synchronized with the video tracks are recorded in the control track 13.

In such a videotape 10, video tracks 12a... and audio tracks 11a, llb
Images and audio are recorded in one block for one song, and a plurality of songs are recorded sequentially.

The control track 13 records one information block 3A, 3B, 3C, . . . for each of the above-mentioned song parts in block units as shown in FIG. Further, the non-recording section 6a is provided between each block, for example between 3A and 3B, and the address information 4B is recorded at the center of the non-recording section 6a in the running direction. This non-recorded portion 6a is divided into a front non-recorded portion 6a-1 and a rear non-recorded portion 6a-2 with respect to the address information 4B. In order to detect that each non-recorded area 6a-1, 6a-2 is a recording area of the address information 4B when cueing, a predetermined time lag time T1 (FIG. 5) during high-speed forwarding is performed.
, and its length Ll is selected. The address information 4B... is recorded as an absolute address sequentially from the starting end of the tape 10, and is recorded as the number of pulses having a predetermined pitch, such as 1.2, 3.4, etc., for example. This pulse pitch is set to be a sufficient pitch that can be read during high-speed running, and is recorded in an area L2 selected with enough margin to prevent malfunction. Note that the recording format may be a bit pulse signal or the like in which the address is binary encoded. Such address information 4B, 4C, 4D, . . . is shown in FIG.

Note that the video tracks 12a... and the audio tracks lla, llb also correspond to the information blocks 3A... recorded on the control track 13, but the portions corresponding to the blank areas 6a... are similarly blank. It may be in a recording state, or a black signal or a certain image may be recorded.

Next, a magnetic tape reproducing apparatus according to the present invention for reproducing such a video tape 10 will be explained with reference to FIGS. 1 and 2. FIG. 1 is a block circuit diagram of the main part, and FIG. 2 is a specific circuit diagram of the signal detection section in FIG. 1. In addition, the first
In the figure, only the cue device P is extracted and the functional part for normal video playback is omitted.

In the figure, 30 is an operation panel, and this panel 30 includes an operation section 31 consisting of song selection operation buttons (for example, numbers 1 to 30),
A corresponding indicator light 32, music selection start button 33, etc. are provided. Each button is a CPU.

It is connected to a microcomputer 34 including RAM and ROM. Meanwhile, Rad3 to the control to play tape 10
The output signal No. 5 is processed by the signal detection section 36. Reference numeral 37 denotes a drive motor for running the tape 10, which is driven by a control circuit 38, which is controlled by a computer 34 and a comparator 39. The comparator 39 compares the output signal from the signal detection section 36 and the output signal from the computer 34 and outputs the result.

The signal detection section 36 is connected to the control head 3 as shown in FIG.
5, a buffer circuit 50, an amplifier circuit 51, an integrating circuit 52, a comparator 53, a timer 54,
It consists of a counter 55.

Next, the operation of the signal detection unit 36 when playing back the video tape 10 with the playback device and searching for the beginning will be described in FIGS. 1 and 2.
This will be explained with reference to the drawings and FIG.

Incidentally, FIG. 5 is a time chart diagram showing signals etc. in the contents section of FIGS. 1 and 2.

In FIG. 1, when the video tape 10 is fed at high speed (rewind or forward) and the control track 13 is played back by the control head 35, the playback signal from the head 35 is first transferred to the buffer circuit 50 and the amplifier circuit 51 as shown in FIG. After predetermined amplification processing is performed in the integrating circuit 5
2, each information block 3A... and address information 4B.
... is integrated to become the signal S1 in FIG. This integrated signal S L is compared with a predetermined threshold value in a comparator 53, and its output is a waveform-shaped pulse signal representing only each information block 3A, that is, a song signal S
Get 2. Then, at the falling edge of this signal S2, the timer 54
is started, and the time lag, time TI (5th
The counter 55 is set after the time-up shown in the figure). Further, the counter 55 is reset at the rising edge of the signal S2, and the address information counted at the timing of the rising edge is output from the signal detection section 36, and the comparator 3
9 is given.

Next, the cueing operation will be specifically explained with reference to FIG. This figure is a flowchart showing the cueing operation.

Now, in FIG. 4, the control head is located in the middle position of the information block 3B, and on the other hand, in FIG.
Assume that the user inputs number n). In this case, the corresponding indicator light 32 lights up on the operation panel 30.

Here, when the music selection start button 33 is operated, the rewind fast forward mode is set and the tape 10 is reversed. At the position ■ immediately after this, the address information 4B is detected by the signal detection unit 3.
Read by 6. Here address information 4B (=
m) is compared with the address fish (=number n) by a comparator 39. The above operations are shown in steps 100 to 107 in FIG.

If m > n, rewind fast forwarding continues as is, and if man, forward fast forwarding is started after stopping at position ■. The arrow in FIG. 4 indicates the case of forward fast forwarding. The address information 4c is read at the intermediate position (3) by forward fast forwarding, and this address information 4c is given to the comparator 39 according to the above-described operation. In this way, address information is read sequentially, and when address mm matches n, that is, m=n, the comparator 39 detects the match and controls the control circuit 38 to stop the motor 37 ( Position ■).

The above operations are performed in steps 108 to 118 in FIG.
Shown below. The basic operation is the same in the case of rewind fast forwarding, and this operation is shown in steps 119 to 125 and step 118 in the same figure.

Then, after stopping, the tape is rewinded for a predetermined length (2) in the fast forward direction just before it is stopped, and is displaced to a non-recorded area of 6 cm2 existing in front of the target information block 3D, and then stopped at position (2). The above operation is performed using Ste Knob 1 in the same figure.
26 to step 129.

With this, the target cue is completed and the play mode king O
Then, the information block 3D corresponding to the preselected address Nan, that is, the target videotape position, is reproduced.

Since address information, which is an absolute address, is directly read, it is possible to detect the recording area of the address information due to a time lag, and to ensure accurate cueing without malfunction. Furthermore, since the position can be easily determined using the absolute address and the tape feeding direction can be determined, high-speed cueing to the target address is guaranteed.

It should be noted that the present invention is not limited to the embodiments illustrated above, and arbitrary changes in the detailed circuit configuration, tape pattern configuration, etc. that do not depart from the gist of the present invention are permitted within the scope of the present invention. .

(Effects of the Invention) As described above, the magnetic tape playback device according to the present invention is provided with an operation section for selectively inputting a plurality of address numbers, and when the tape is fed, the address numbers recorded at different positions on the magnetic tape are The corresponding address information is reproduced, and when the selected address number matches the value of the reproduced address information, the tape feed is stopped and the beginning of the magnetic tape can be found, so that the following effects are achieved. .

First, cueing can be performed by reading address information, which is an absolute address, so it is possible to achieve a significantly faster cueing speed than cueing using the conventional counting method.

Second, by directly reading the absolute address and detecting the recording area of the address information in the embodiment, accurate cueing without malfunction can be performed.

Thirdly, it is possible to effectively use the syntroll tracks of video tapes, etc., and it is also possible to easily create low-cost video tapes by using existing tapes as they are, thereby reducing the cost of the entire device. It is suitable as a video karaoke device.

[Brief explanation of the drawing]

FIG. 1 is a block circuit diagram of the main part of the magnetic tape reproducing device according to the present invention, FIG. 2 is a specific circuit diagram of the signal detection section A shown in FIG. 1, and FIGS. 3 and 4 are reproduction according to the present invention. 5 is a track pattern diagram of a magnetic tape (video tape) that can be used in the apparatus; FIG. 5 is a time chart diagram showing signals, etc. of the content section in FIG. 2; and FIG. 6 is a flowchart diagram of a cueing operation. In the drawings, 10...magnetic tape, 31...operation unit, 34...microcomputer. 35...Control head, 36...Reliability % detection section, 39...Comparator, n...Address number, m...Address information.

Claims (1)

[Claims] 1. An operating unit for selectively inputting a plurality of address numbers, and reproducing address information corresponding to the address numbers recorded at a plurality of different positions on a magnetic tape during tape feeding, and A magnetic tape playback device that stops feeding the tape and searches the beginning of the magnetic tape when the address number read and the value of the read address information match. 2. When feeding the tape, the address information reproduced immediately after starting the magnetic tape is compared with the designated address number, and the tape is run in the direction where address information matching the address number is recorded. A magnetic tape reproducing device according to claim 1, characterized in that: 3. The magnetic tape reproducing apparatus according to claim 1 or 2, wherein after stopping the tape feeding, the magnetic tape is rewinded by a predetermined length in the immediately preceding running direction. 4. The magnetic tape reproducing apparatus according to claim 1 or 2, wherein the address information is reproduced after reading a non-recorded area provided on the magnetic tape that indicates an address information recording area. .