JPS60205832A - Checking device of record content of recorded magnetic tape - Google Patents

Abstract

PURPOSE:To attain accurate and stable check of the record contents of a magnetic tape with no dependence on the human aural sense, by converting the record contents of a recorded magnetic tape to be checked into digital data for comparison with the reference data. CONSTITUTION:When a magnetic tape is reproduced at an n-fold speed (8 times) as high as a normal reproduction speed, the output of a reproduction head 1 is supplied to a filter 16 via an amplifier 15 to extract the component of 1kHz with a center frequency 8kHz. This output of extraction is sent to an envelope detector 17 and converted into the digital data by an A/D converter 3A through a sampling/holding circuit 18. The reproduction output of the head 1 is supplied to a filter 20 after amplification, and a cue signal is extracted. The cue signal of 7Hz is extracted with a center frequency 56Hz of the filter 20 and undergoes the waveform shaping through the level comparison of an analog comparator 4A. A CPU21 supplies these results to an input port 23 and delivers the result of the reading check to a display device 30 via an output port 27. Thus the accurate decision is secured since the record contents of a magnetic tape are converted into the digital data for comparison with the reference data.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for inspecting recorded contents of a recorded borium tape.

Conventionally, inspections in the production of pre-recorded magnetic tapes involve playing the pre-recorded magnetic tape using a magnetic tape player and having the inspector listen to the playback sound to check whether there are any errors in the recorded content, or whether the recorded content has been recorded with other content. They checked to see if the tape was fresh, if the recording level was appropriate, and if the recording was made from the beginning of the song, in other words, if the beginning of the song was cut off.

However, since the test was based on human hearing, there were disadvantages in that the judgment criteria varied from person to person and that the test required a long time.

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide an apparatus for inspecting the recorded contents of a recorded recording tape, which eliminates the above-mentioned drawbacks.

The present invention will be explained below.

FIG. 1 is a functional block diagram of the present invention.

Recorded contents are simultaneously detected from sides A and 8 of a recorded magnetic tape by playback heads 1 and 2, respectively.

The reproduction output from the reproduction head 1 is supplied to an A/D converter 3 and converted into digital data. On the other hand, the reproduction output from the reproduction head 2 is supplied to an analog comparator 4 that detects a cue signal, thereby detecting the presence of the cue signal.

In this specification, a cue signal is a signal of a predetermined length and a frequency below an audible frequency that is recorded on the B side to indicate the end of the magnetic tape when producing a recorded magnetic tape. A frequency of about 7Hz is used.

Therefore, the state of the magnetic tape near the cue signal is schematically shown in FIG.

In FIG. 2, 5 is a magnetic tape, 6 is a league part, A is a track on the A side, and B is a trunk on the B side. 7 is a cue signal; cue signal 7
The recording is made on the A trunk from a position a predetermined distance away from the B track, and the recording of the B track ends before the cue signal 7 is generated. Therefore, when the cue signal 7 is detected, the so-called head cutoff does not exist.

The output of the A/D converter 3 is supplied to the storage means 9 via the switch means 8 and stored therein. .

On the other hand, numeral 10 is a storage means, and the storage means 10 records data obtained by digitally converting signals recorded on a magnetic tape. Further, the switch means 8 is set to be closed after a predetermined period of time has elapsed based on the cue signal 7, in order to make the stored data in the storage means 10 and the stored data in the storage means 9 coincide on the time axis. be.

The stored contents of the storage means 9 and the stored contents of the storage means 10 are compared and calculated by the digital comparison calculation means 11, and it is detected whether the sum of the differences is less than a predetermined value, and when the sum of the differences is less than the predetermined value, the reproduced magnetic tape is If it is determined to be a good product, and if it exceeds the predetermined value, it is determined that the reproduced magnetic tape is not a good product, and the display 12 displays this fact.

Next, the present invention will be specifically explained using an example.

FIG. 3 is a block diagram showing the configuration of an embodiment of the present invention.

In one embodiment of the present invention, a case will be exemplified in which a non-defective item is selected from recorded magnetic tapes to be inspected, and the recorded contents of the non-defective item are read and used as reference data. Furthermore, an example will be described in which a magnetic tape is played back and inspected at n times the normal playback speed, for example, 8 times the normal playback speed.

The reproduction output of the reproduction head 1 is amplified by a reproduction amplifier 15 and then supplied to a filter 16. Here, the center frequency of the filter 16 is set to 8 KHz, and the IKHz component at normal reproduction speed is extracted.

The output of the filter 16 is supplied to an envelope detector 17 to detect the envelope of the output of the filter 16, and the output of the envelope detector 17 is supplied to a sample and hold circuit 18 for sampling and holding. The output is converted into digital data by an A/D converter 3^.

On the other hand, the reproduction output of the reproduction head 2 is amplified by a reproduction amplifier 19 and then supplied to a filter 20 to extract a cue signal. That is, the center frequency of the filter 20 is set to 56 Hz, and the cue signal (
Frequency 7Hz) is extracted. The output of the filter 20 is supplied to an analog comparator 4°, and the waveform is shaped by level comparison.

On the other hand, 21 is a microcomputer, CPU22
, an input boat 23, a ROM 24, a RAM 25, a timer unit 26, and an output boat 27. A/
The output of the D converter 36, the output of the analog comparator 48, and the output of the instruction switch 28 for instructing the start of inspection are supplied to the input port 23 and read into the microcomputer 21, and the microcomputer 2r displays the inspection results. output to the display 30 via the output boat 27,
A control signal E-1 is output for controlling a recorded tape playback device that is not transmitted orally. The control signal E is a signal for outputting the recorded Kenki tape to be inspected from the playback device, and the control signal F
is a signal for loading the recorded magnetic tape to be inspected into a playback device, control signal G is a signal for instructing to rewind the magnetic tape, and control signal H is a signal for instructing to rewind the magnetic tape. , when the reproducing device receives the control signal E-H, ejects the magnetic tape from the reproducing device, mounts the magnetic tape, rewinds the magnetic tape, and reproduces the magnetic tape. Note that the control signal E is supplied to the input port 23 in place of the output of the instruction switch 28 so as to cause the inspection to be continued.

Also, 29 is Denbuchi.

In one embodiment of the present invention configured as described above, the ROM
The operation will be explained in accordance with the flowchart of FIG. 4 showing the program stored in 24.

First, a good recorded magnetic tape to be inspected is selected from among the recorded magnetic tapes to be inspected, and the recorded magnetic tape to be inspected is placed in a loader so that the good recorded magnetic tape to be inspected is loaded into the playback device first. I'll keep it. The RAM 25 is divided into a first area for storing reference data, a second area for storing data recorded on the recorded magnetic tape to be inspected, and a working area for other calculations. .

By momentarily turning on the instruction switch 28, the output of the instruction switch 28 is read into the microcomputer 21 via the input port 23. The microcomputer 21 that has read the output of the instruction switch 28 is connected to the output boat 2.
A control signal F is outputted through the playback device 7, and the magnetic tape is loaded into the playback device (step a). It goes without saying that the magnetic tape attached at this time is the above-mentioned good quality tape.

Following step a, the initial trigger sensitivity is set (step b), and following step b, it is checked whether there is any slack in the winding of the magnetic tape (step C). If there is no slack in step C, a control signal 1-1 for reproduction is output, and the loaded magnetic tape is reproduced (step d). When slackness is detected in step C, a control signal G for rewinding is applied, and the mounted magnetic tape is rewinded (
Step e). Completion of rewinding is checked based on whether the end of the tape is detected within a predetermined time after rewinding in step e (Stenfugo).

When the end of the tape is detected within the predetermined time in step f, it is assumed that rewinding has been completed within the predetermined time, and step d is executed subsequent to step f. If the rewinding is not completed within the predetermined time in step f, the rewinding is stopped following step f and a failure is displayed (
Step g).

Following step g, output the eject signal E to eject the attached magnetic tape (step h)
. By executing step h, the eject signal E is read into the microcomputer 21 in place of the signal from the instruction switch 28, and the process is executed again from step a. In this case, the magnetic tape, which was considered to be good, turned out to be not good.

In step d, the output from the reproducing head 1 is amplified by the regenerative amplifier 15, the 8 KHz component is extracted by the filter 16, and envelope detection is performed by the envelope detector 17. This envelope output is sampled and bolded in the sample and hold circuit 18 and converted into digital data in the A/D converter 36. On the other hand, the output from the regenerator 2 is amplified by a regenerator amplifier 19, a 56 Hz component is extracted by a filter 20, and the waveform is shaped by an analog comparator 4n.

Therefore, the generation timing of the output of the A/D converter 36 and the output of the analog comparator 4o is clear from FIG. Then, it is detected whether a cue signal has been input within a certain period of time from the time when the magnetic tape is played back (step i). When a cue signal is detected within a predetermined time in step i, it is then detected whether a trigger signal is generated within a predetermined time, and upon this detection, reading of data from the A//D converter 3o is started ( Step J). In step j, a trigger signal is generated by the timer unit 26 when a predetermined time has elapsed since the detection of the cue signal. This corresponds to the switch means 8 shown in FIG. Although the case of FIG. 1 shows the case of the switch means 8, the switch means 8 is omitted and the digital data from the -IA/D converter 36 is read following step i, and when this digital data is equal to or higher than a predetermined value, the switch means 8 is omitted. This may be detected and used as a trigger signal. Therefore, it is the same as detecting the trigger signal based on the level, and the switch means 8 does not necessarily have to be set based on time.

Following step j, the digital data from the A/D converter 3A is sequentially stored in the first area of the RAM 25 (step k), and the number of words assigned to the first area is stored (step β).

Following step l, the control signal G is replaced with the control signal H.
step m), in which the magnetic tape is rewound by outputting .In step m), it is detected whether the magnetic tape has been rewound within a predetermined time (step n). If the magnetic tape can be rewound within a certain period of time in step n, it is detected whether the magnetic tape is slack (step 0).

If the trigger signal is not generated within a certain period of time in step j, the magnetic tape is rewound (step j).

p). In step j, if the trigger signal is obtained by setting the time after the cue signal is generated, the trigger signal will always be generated if the cue signal is generated, but if the trigger signal is obtained by the level. Recording occurs even if a cue signal is detected.

Following the rewinding in step p, it is detected whether the magnetic tape has been rewound within a predetermined time (step q).

When the magnetic tape is rewound within a certain period of time in step q, it is checked whether the trigger sensitivity is at its maximum following step q (step r). If the trigger sensitivity is not the maximum in step r, the trigger sensitivity is increased (step S), and the process is subsequently executed from step e.

When the cue signal is not detected within a predetermined time in step i, when the rewinding of the magnetic tape is not completed within a predetermined time in step q, and when the trigger sensitivity is maximum in step r, step i, step q, and step r are performed. Then step g is executed.

If the magnetic tape is not slack in step 0,
Following step 0, the magnetic tape is played back (
Step t). When it is detected in step 0 that the magnetic tape is slack, rewinding is performed and it is detected whether the magnetic tape has been rewound within a certain period of time (steps u, v). When rewinding is completed within a predetermined time in step V, step t is followed by step V.
Execute.

Step i in regeneration at step t.

Similarly to j, whether a cue signal is generated within a predetermined time (step W), or if a cue signal is generated within a predetermined time in step W, whether a trigger signal is detected within a predetermined time following step W (step X) is checked. When the trigger signal is detected within a predetermined time in step RAM25
Write 1. over a predetermined word in the second area of . key (step y+z).

Following step 2, step aa) of rewinding the magnetic tape, and following step aa, it is checked whether the magnetic tape has been rewound within a predetermined time (step ab). When the magnetic tape is rewound within a predetermined time in step ab, following step ab, the contents stored in the first area and the contents stored in the second area are sequentially compared, and the difference between them is calculated (step ac). It is determined whether the calculation result in step ac is less than or equal to a predetermined value (step ad).

Here, step l (and the contents stored in the first storage area in l are reference data (DR), and step a
The contents stored in the second storage area in c and ad are data to be inspected (DT). Since the target magnetic tapes in steps β, ac and ad are the same in the case of the first comparison, the comparison calculations in steps β, ac and ad will confirm that they have been reproduced normally. The comparison calculation in step ad 6( is Ev −1−DT/DR(D”ff >D body”・(tl
Ev=1-DR/DT (DR>DT)-f21Ev=
0 (DR=DT)-(3) to determine whether ΣEV is less than a predetermined value.

In the case of equations (1) and (2), there is an error, and in the case of equation (3), there is no error.

If ΣEv is less than a predetermined value in step ad, the attached magnetic tape is selected as a good product (step a
e). Following step ae, the magnetic tape is ejected and taken out of the reproducing apparatus (step af).

In the above steps, the inspection of the magnetic tape selected as the first non-defective product is completed, and it is determined to be non-defective in step ae. Incidentally, as will be described later, steps o-ae are also steps for determining the magnetic tape that has been subsequently mounted.

Here, in the RAM 25, the first and second areas are each set to 2 bytes, the working area is set to IK bytes, and a total capacity of 5 is selected.
Assuming that the D converter 36 converts into digital data of 1 word and 1 hide, and the sampling period in the sample ant bold circuit 18 is 1 m5 ec, then 2 seconds worth of digital data will be stored in the RAM 25. This 2 seconds worth of digital data corresponds to 16 seconds worth of normal playback speed, and this level of inspection and comparison is sufficient for determining the storage and content of the magnetic tape. Also, from the time when the cue signal is detected, steps j and X are omitted and A
/, the output digital data of the D converter 36 may be stored in the RAM 25, and in this case, as is clear from FIG. “00 over a period of length
(H)” will be written, and therefore RA
It is sufficient to increase the capacity of M25. Therefore, it is not necessary to provide the switch means 8 with a timer function in FIG. 1.

Following step af, the control signal F is output, and the next recorded magnetic tape to be inspected is loaded into the reproducing device. This attachment is checked in step 7 ag, and when it is detected in step ag that the next recorded magnetic tape to be inspected is attached, step 0 is executed following step ag. In the steps following step 0, the recorded content of the next recorded magnetic tape to be inspected is compared with the recorded content of the recorded magnetic tape to be inspected that was determined to be non-defective as described above to determine whether it is a non-defective product. Become.

In addition, if it is not possible to rewind within the predetermined time in step ab, and if ΣEv exceeds the predetermined value in step ad, the recorded magnetic tape to be inspected is inspected for the first non-defective product following steps ab and step ad. It is checked whether there is one (step ah). step ah
If this is the first non-defective inspection in step ah
Subsequently, the magnetic tape is rewound (step ai), and subsequent to step ai, it is checked whether the magnetic tape has been rewound within the determination time (step ai).
j) Even if the magnetic tape can be rewound within a predetermined time in step aj, step g is executed subsequent to step aj even if the magnetic tape cannot be rewound within a predetermined time.

If the cue signal and trigger signal are not detected within a predetermined time in step W and step X, step ah
Execute.

If step ah is not the first inspection of a non-defective item, then step ah is followed by checking whether the magnetic tape is slack (step ak). and step an), step an
Subsequently, it is checked whether the failure is due to the fact that the cue signal is not generated within a predetermined period (step ao).

If the defect occurs in step aO because the cue signal is not generated within a predetermined period, the rotor of the magnetic tape is stopped (step aq'), and then step af is executed to eject the magnetic tape from the reproducing device.

If the failure is due to something other than the fact that the cue signal is not generated within a predetermined period in step aO, then following step aO, check whether the failure has occurred 2' times in succession;
If it is checked that the product has failed twice in a row, step aq is executed, and if it has not been found to be defective twice in a row, step af is executed following step aq.

In step ak, if there is slack in the magnetic tape, the magnetic tape is rewound (aβ); subsequent to step al, it is checked whether the magnetic tape has been rewound within a predetermined time; step am); and execute step an.

In the above-described embodiment of the present invention, a case has been exemplified in which the magnetic tape is inspected by running at a speed eight times the running speed of the magnetic tape during normal reproduction, but there is no need to limit the speed to eight times.

Furthermore, in the above embodiment, a good product is selected from among the recorded magnetic tapes to be inspected, and this is reproduced and stored in the first area of the RAM 25 as reference data to be used as a reference for the recorded magnetic tape to be inspected. However, instead of selecting non-defective products from the recorded magnetic tapes to be inspected, the signals recorded on the magnetic tapes may be digitally converted and stored in the ROM 24 to be used as reference data.

As explained above, according to the present invention, since the reference data and the stored contents of the recorded magnetic tape to be tested are converted into digital data and compared, judgments can be made accurately, and stable tests can be performed because the test does not rely on human hearing. can. In addition, the number of inspections, the number of passes, the pass ratio, etc. can be easily calculated.

Furthermore, since the reproduction speed can be increased for inspection, the inspection time can also be reduced.

[Brief Description of the Drawings] Fig. 1 is a functional block diagram showing one embodiment of the present invention;
The figure is a schematic diagram of the vicinity of the cue signal recording portion of the magnetic tape, Figure 3 is a block diagram showing a specific example of an embodiment of the present invention, and Figure 4 is an operation of the embodiment of the present invention shown in Figure 3. It is a flowchart provided for explanation. 1 and 2... reproducing head, 3... A/D converter, 4A... analog comparator, 5... magnetic backplane,
8...Switch means, 9 and 10...Storage means,
11... Digicle comparison calculation means. Agent Hideo Takino 10th 20th 86 5 B 7

Claims (1)

[Claims] An analog comparator is supplied with the playback output when the recorded magnetic tape to be inspected is played at a speed higher than the normal playback speed and detects a cue signal, and the playback output of the track where no cue signal is recorded is supplied. an A/D converter for converting into digital data; a first storage means for storing reference data corresponding to the recorded content of the recorded magnetic tape to be inspected; A second storage means that is supplied and stores the stored contents of the first storage means and a second record corresponding to the stored contents.1. digital comparison calculation means for comparing the stored contents in the means a and detecting whether the sum of the differences is less than or equal to a predetermined value and outputting the result;
An apparatus for inspecting the recorded content of a recorded magnetic tape, characterized in that the output of the analog comparator is present, and the quality of the recorded content of the recorded magnetic tape to be inspected is inspected based on the detection output of the digital comparison calculation means.