JPH0322678B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Technical Field> The present invention relates to a position information reproducing apparatus for reproducing a magnetic tape on which position information such as position or time is recorded together with recorded information such as an audio signal.

<Prior art> Figure 1 shows an example of a tape format in which position information 1 is recorded on a dedicated position information track, and recorded information 2 created by pulse code modulation (PCM) of an audio signal, etc. is recorded on a track dedicated to position information. This was recorded on the track. In addition, Fig. 2 shows an example of the format of position information, where 3 is a synchronization signal, 4 is data,
5 is an error detection and correction code such as a CRC (Cyclic Redundancy Check Code).

By the way, due to dubbing or the like, as shown in FIG. 1, there may be gaps in the recorded information, and there may also be gaps in the position information.

When trying to play such a magnetic tape and display position information, etc., 1011, 1012,
There is a problem that the lines 1013, 1014, 1018, and 1019 are discontinuous and unsightly. In addition, there is a problem that during a high-speed search, if an attempt is made to search for the location 1015, for example, the search becomes impossible because the corresponding location information does not exist.

<Object of the Invention> Therefore, an object of the present invention is to provide a position information reproducing device capable of displaying the position or time even in the interval where position information such as the position or time is not recorded.

<Structure of the Invention> In order to achieve the above object, the position information reproducing apparatus of the present invention includes a reproducing means for reproducing a magnetic tape on which recorded information and position information such as a number or time are recorded, and a reproducing means for reproducing the above-mentioned information from the reproducing means. After receiving the location report,
While this positional information is unrecorded, it is controlled by the output of the outer section detecting means and the outer section detecting means, and the position information before or after the outer section and the outer section are detected. calculation means for calculating positional information of a current playback position in the middle part from frame pulses generated based on positional information before or after the frame pulse; The present invention is characterized by comprising a display device for displaying images.

<Examples> The present invention will be described in detail below with reference to illustrated examples. However, since the recorded information reproducing unit is not directly related to the present invention, its explanation will be omitted.

As shown in FIG. 3, position information 1 reproduced by the position information reproduction head 6 is amplified by a reproduction amplifier 7, subjected to waveform shaping etc. by a waveform shaping circuit 8, and converted into a digital signal. A synchronization signal 3 is detected from this signal by a synchronization signal detection circuit 11, and a clock generation circuit 12 generates a timing pulse based on the synchronization signal to control each circuit. However, the tape running direction is determined by synchronization signal 3, data 4, and CRC.
There is a forward direction, which continues with 5, and a reverse direction, which continues with synchronization signal 3, CRC5, and data 4. Since the timing pulses generated in each direction are different, they are switched by the FWD/BWD switching signal 20.

On the other hand, the digital signal output from the waveform shaping circuit 8 is demodulated by a demodulation circuit 9, and error detection and correction are performed by an error detection/correction circuit 10 serving as an interval detection means. The position data 21 is position data after error correction, and the error 22 is a signal that becomes active when the error cannot be corrected.
That is, the error 22 becomes active when there is a period in which position information is not recorded. A frame pulse 2 generated from the clock generation circuit 12 based on a synchronization signal before or after the above-mentioned interval.
3 is a pulse having the same period as the synchronization signal.

Now, if the position data 21 is correct, that is, if it is not an intermediate position, the error 22 is inactive, so the output of the AND gate 13 does not change. Furthermore, frame pulse 23 and inverter 1
The AND gate 15 with the error 22 passing through 4 is input as a load signal to an up/down counter 17 as an arithmetic means. Therefore, the display data 24 becomes equal to the position data 21.

On the other hand, when it is in the middle part, that is, position data 2
When 1 is erroneous, error 22 is active, so the output of AND gate 15 does not change, and therefore up/down counter 17 is not loaded with position data 21. Instead, the output of the AND gate 13 becomes active, and a pulse is input to the up/down counter 17 via the switch 16 to the up side when the tape is being fed forward, and to the down side when the tape is being fed backwards.
Therefore, the value of the display data 24 changes every frame.

This display data 24 is input to the display device 18, and even when there is no position information 1, the tape position is displayed as shown in FIG. Above display data 24
is also input to the location search device 19.

In this way, even when positional information on the tape is completely missing, the device itself generates a frame based on the positional information before or after the missing part, without using other signals recorded on the tape. By integrating time using pulses and calculating the positional information of the missing portion, the tape position can be displayed on the display device 18, and the positional information will not be displayed discontinuously, making it easy to see. . Furthermore, by inputting the display data 24 into the location search device 19, it is possible to search even locations where no location information exists.

It is also possible to display the tape position without reproducing correct position information at all, for example by automatically resetting the up/down counter 17 at the leading edge of the tape. Furthermore, time information may be used instead of position information.

<Effects of the Invention> As is clear from the above explanation, the location information reproducing device of the present invention can
Even if the position information cannot be reproduced from the tape at all in the middle part, the position information is generated based on the frame pulses generated by the device itself, so in the middle part,
This method has great advantages such as being able to display the position or time, making the display of the position or time continuous so that it does not look unsightly, and making it possible to search for tape positions where no position information is recorded.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a tape format, FIG. 2 is a diagram showing a position information format, FIG. 3 is a block diagram of an embodiment of the present invention, and FIG. 4 is a time chart of the above embodiment. 7...Reproduction amplifier, 8...Waveform shaping circuit, 9...
...Demodulation circuit, 10...Error detection and correction circuit, 11...
...Synchronization signal detection circuit, 12...Clock generation circuit, 17...Up/down counter, 18...
...display device.

Claims (1)

[Scope of Claims] 1. A reproducing means for reproducing a magnetic tape on which recorded information and positional information such as a number or time are recorded; A gap detecting means for detecting a gap, and a position information of a position before or after the gap, which is controlled by the output of the gap detecting means, and a position information before or after the gap. and a display device that receives the output of the calculation means and displays the positional information of the intermediate portion based on the frame pulse generated based on the frame pulse. A location information reproducing device characterized by: