JPH06236633A - Data correction device - Google Patents

Abstract

PURPOSE:To compensate the reading error of data caused by the deviation of an azimuth by comparing at least two read data among the data read from a magnetic tape and deciding a delaying degree among the respective data. CONSTITUTION:The data read from eight tracks of the magnetic tape 1 by eight heads is inputted to a control circuit 5. By the control circuit 5, the address data included in the respective data read by eight heads is compared. Then, there is difference among the address data, the data read by the respective heads is temporarily recorded in a memory. The data as much as one frame is read by the head reading the delayed tracks and the data as much as one frame on the tracks T1-T8 is temporarily recorded in the memory. When the data as much as one frame is read by the head reading the delayed tracks and the whole of the data is completed, it is outputted to a data reproducing device 6 as information as much as one frame and a voice or the like is reproduced based on the data as much as one frame.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape recorder,
In particular, the present invention relates to a data correction device that is effective in correcting read data.

[0002]

2. Description of the Related Art One of the factors that determine the recording and reproducing quality of a tape recorder is the angle between the length of the tape and the head, which is called the azimuth angle. This angle is an appropriate angle (usually 90 degrees between the tape advancing direction and the head gap direction).
If it deviates from °), recording and playback quality will deteriorate. For this reason, many tape recorders are equipped with an azimuth angle adjusting device that corrects the deviation of the azimuth angle.

FIG. 11 is a front view showing a conventional azimuth angle adjusting device. The adjustment of the azimuth angle of the head unit 2 is usually performed during product assembly.
While reproducing, the screw 17 installed near the head unit 2 is rotated so as to maximize the output while watching the output waveform with an oscilloscope or the like, and the head mount 18 elastically supported by the spring 19 is moved. By adjusting the tilt angle, the angle 20 of the head unit 2 is changed to adjust the azimuth angle.

[0004]

However, even if the azimuth angle is adjusted at the time of assembling the product, there is a problem that the adjusted azimuth angle shifts due to a change with time. Also,
Even if you feel deterioration of the playback sound while playing the tape and you notice a deviation in the azimuth angle, you cannot make a reliable adjustment because a special adjustment device is required to adjust the azimuth angle, and it is also a special adjustment. Even if there was a device, there was a problem that it took time to manually adjust the azimuth angle. Further, when the deviation of the azimuth angle is not noticed, the reproduced sound is heard with the deteriorated sound quality, and when it is used for data recording, there is a problem that the data error increases. Further, the same phenomenon occurs when the azimuth angle is deviated due to the arrangement of the heads in the head unit.

Therefore, in view of the above problems, an object of the present invention is to reduce error in reading data by automatically correcting the error data generated due to the deviation of the azimuth angle, and to prevent the deterioration of the sound quality. It is intended to provide a correction device.

[0006]

DISCLOSURE OF THE INVENTION The present invention is to solve the above-mentioned problems, and reproduces data recorded on a plurality of tracks of a magnetic tape by a plurality of heads provided corresponding to the respective tracks. In the apparatus, the data read by at least two of the heads, first and second heads, are compared with each other, and comparing means for determining the degree of delay between the respective data and the comparison result of the comparing means are used to detect the delayed data. A data correction device comprising a correction means for delaying data proceeding to a standard.

[0007]

According to the data correction apparatus of the present invention, the comparison means compares the data read by at least two heads to detect the deviation of the azimuth angle. That is, the larger the difference between the two data, the larger the deviation of the azimuth angle,
A deviation of the azimuth angle can be detected from the comparison result. The comparing means determines the degree of delay between the respective data, and the correcting means for delaying the advancing data based on the delayed data corrects the data reading error.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. In order to make the explanation easier to understand, a tape recorder that records / reproduces digital signals on / from eight tracks on a magnetic tape with eight recording / reproducing heads will be taken as an example. First, the head structure and data recording on the magnetic tape will be described. The state will be described.

FIG. 2 is a detailed view showing the structure of the head. In the head unit 2, eight digital recording heads 7 corresponding to each track and a digital reproducing head 8 are arranged side by side in a direction perpendicular to the tape traveling direction, and the digital recording heads 7 are magnetic tapes. Digital signals are recorded on eight tracks, and the digital reproducing head 8 reads the digital signals recorded on the magnetic tape in eight tracks. Further, the analog reproducing heads 9 are arranged in two rows at a right angle to the tape traveling direction at intervals, and the analog reproducing heads 9 are arranged on the magnetic tape.
An analog signal is recorded on the tracks, and the analog signals recorded on the two tracks are read.

FIG. 3 is a detailed view showing the structure of the magnetic tape. The magnetic tape 1 has eight tracks indicated by T1 to T8, and each track has a block in which the same specific data (delimiter data) is recorded on each track, which indicates a frame delimiter called IFG12. And IFG1
Data is recorded between 2a to IFG 12b in units called frames 11. The frame 11 is recorded at the same position in the tape traveling direction for each track, and the frame 11 is further divided into a plurality of blocks, for example, 32 blocks, and data is recorded in each data block unit. This 32 × 8 data constitutes reproduction information for one frame. Furthermore, this 32
A header 13 and a body 14 are provided in each block of each data block, and the header 13 includes a frame for indicating each track for synchronizing data reading and the same synchronization data 15 and the order of data in each block. Address data 16 including a number and a block number is recorded, and data to be actually recorded is recorded in the body 14. That is, the IFG data 12 and the synchronization data 15 are data that should be read simultaneously by each head, and are at the same position in the tape traveling direction. Regarding the address data 16, data having the same address value is data that should be read simultaneously by each head and is at the same position in the tape moving direction.

Next, the configuration of one embodiment of the present invention will be described.
FIG. 1 is a block diagram showing an embodiment of the present invention. Data read by eight heads from the eight tracks on the magnetic tape 1 are input to the control circuit 5. The control circuit 5 compares the address data included in the data read by each of the eight heads. When there is a difference in the address data, the data read by each head is temporarily recorded in the memory, and the head reading the delayed track writes one frame of data, that is, 32 data blocks. Information of one frame (= data unit composed of 8 tracks × 32 data blocks and divided by IFG12a to IFD12b) read by all heads when all data for one frame in the read and tracks T1 to T8 are prepared. To the data reproducing device 6. Then, the data reproducing device 6 reproduces necessary information, that is, voice or the like, based on the obtained data for one frame.

FIG. 4 and FIG. 5 are flowcharts showing an example of processing performed by the control circuit 5. Step S1
Then, the counter n is initialized to 1. At step S2, the tracks T1 to T8 read by the heads H1 to H8 are read.
Address data is input and the process proceeds to step S3.

In step S3, the frame number and block number included in each address data corresponding to each input track T1 to T8 are compared to find the most advanced track among the tracks, and then the process proceeds to step S4. move on. In step S4, it is determined whether or not there is a difference in the address data of each track. If there is no difference in the address data, it can be determined that there is no deviation in the azimuth angle. Therefore, the process proceeds to step S22, and the read data is left as it is.
Send to. If there is a difference in the address data, it is determined that there is a deviation in the azimuth angle, and the process proceeds to step S5.

In step S5, the values of counters nT1 (counter of track T1) to nT8 (counter of track T8) are set to 1 as an initial setting, and a memory area for temporarily storing the read data, in this example (p -T
m) Specify the area (m is the track number). This memory is divided into 16 areas as shown in FIG.
In each area, 32 pieces of data having the same frame number and track number are stored. Also (p-T
In the area m), there are eight areas corresponding to each track.
It is specified to write the data of the first frame (first input frame) of each track to this area. And
The area for storing the data of the first frame of the track Tm is designated as the (p-Tm) area, and the area for storing the data of the next frame (second frame) is designated as the (q-Tm). Then, the data of the next frame is designated as (p-Tm) again, and the data of the subsequent frame is also (p-Tm).
-Tm) area and (q-Tm) area are designated alternately. However, in the present embodiment, the maximum value of the azimuth shift is specified as one frame by converting the data amount and the area is specified and recorded cyclically. However, when the azimuth shift amount is expected to be large, two frames or It is necessary to use the memory area for several frames cyclically. Then, the process proceeds to step S6, and the frame after the IFG 12 of the most advanced track obtained in step S3 is read, that is, the frame in which all the data of all the tracks can be read first is set as the first frame, and the area specified in step S5 is set. Processing for starting writing is performed in units of one data block, and the flow advances to step S7.

In step S7, it is determined whether or not all the data of the frame indicated by the counter n has been written. That is, one frame is made up of 8 track × 32 data blocks, and it is determined whether or not all 8 track × 32 data have been written in the memory designated area of the nth frame. If all the data of the n-th frame has been written, it means that the data of the n-th frame has been completed, so the process proceeds to step S20, and the data prepared for one frame is output to the data reproducing device 6, and then the counter 1 is added to n (step S21) and the process returns to step S6. If all the data of the nth frame has not been written in step S7, the process proceeds to step S8. Immediately after the power is turned on, n = 1 and the process is executed on the first frame, and the process is continued on the frame.

In step S8, the nT-th track of the track T1.
It is judged whether 32 data blocks of one frame have been written in the memory designated area, (p-T1) area or (q-T1) area ((p-T1) area immediately after power-on), and the writing is completed. NT1 of track T1 if
Since all the frame data are available, the process proceeds to step S9. If the written area is the (p-T1) area, the (q-T1) area is designated as the area to be stored next. Conversely, if the written area is the (q-T1) area, the next The (p-T1) area is designated as the area to be stored in the memory, and the process proceeds to step S10 to add 1 to the counter nT1. That is, the counter value for starting the process for the data of the next frame to be input is changed, and the data of the frame indicated by nT1 is written in the area designated in step S9 in step S11. Also step S
If writing of 32 pieces of data of the nT1th frame of the track T1 is not completed in 8, the nT1th of the track T1
Since all the frame data are not available, step S12
Go to.

In steps S12 to S15, the same processing as that in steps S8 to S11 for the track T1 is performed on the data of the track T2, and the same processing is performed for the tracks T3 to T8 (not shown). The track T8 is shown in steps S16 to S19). If the writing of the 32 pieces of data of the nT8 frame of the track T8 is not completed in step S16, the data of the nT8 frame of the track T8 is not complete. Return to S6.
It should be noted that the counters n and nT1 to nT8 need not have the number of digits that can completely count the number of frames.
Since only the amount corresponding to the difference in the data read timing due to the azimuth shift of the head is sufficient, the counter of a short digit may be cyclically counted, that is, if it overflows, it may be counted from 0 again.

FIGS. 7 and 8 are flowcharts showing another example of the processing performed by the control circuit 5. In step Q1, the counter n is initialized to 1, and the counters nT1 (counter of track T1) to nT8 (counter of track T8) for counting the frame numbers of the tracks T1 to T8 recorded on the magnetic tape are initialized to 0.

At step Q2, the address data of the tracks T1 to T8 read by the heads H1 to H8 are input, and the process proceeds to step Q3. In step Q3, the block numbers included in the address data corresponding to the input tracks T1 to T8 are compared to find the most advanced track among the tracks, and then the process proceeds to step Q4.

In step Q4, it is determined whether or not there is a difference in the address data of each track. If there is no difference in the address data, it can be determined that there is no deviation in the azimuth angle. Send to the playback device 6. If there is a difference in the address data, it is determined that there is a deviation in the azimuth angle, and the flow advances to step Q5.

In step Q5, a memory area for temporarily storing the read data, in this example, a (p-Tm) area (m is a track number) is designated. This memory is the sixth
As shown in the figure, it is divided into 16 areas, and 32 pieces of data having the same frame number and track number are stored in each area. In the (p-Tm) area, there are eight areas corresponding to each track. In this area, the head corresponding to each track writes the data of the first input frame after reading the IFG data. Then, the area for storing the data of the first frame of the track Tm is designated as the (p-Tm) area,
The area for storing the data of the next frame nTm is (q-
Tm). Then, the data of the next frame is designated again in (p-Tm), and the subsequent frame is also designated alternately in the (p-Tm) region and the (q-Tm) region. However, in the present embodiment, the maximum value of the azimuth shift is specified as one frame by converting the data amount and the area is specified and recorded cyclically. However, when the azimuth shift amount is expected to be large, two frames or It is necessary to use the memory area for several frames cyclically. Then, in step Q6, head H1 and head H
It is determined which one of 8 is reading data earlier. That is, if it is determined which of the head H1 and the head H8 is reading the IFG data first, the direction in which the head is tilted is obtained, and the head H1, the head H2, ... The head H8 are read, or vice versa. I know if it is. Then, when reading from the head H1, step Q7
When the head H1 detects IFG data, step Q7 is repeated until the head H1 detects IFG data. When reading from the head H8, the process proceeds to step Q8, and step Q7 is repeated until the head H8 detects the IFG data, and when the IFG data is detected, the process proceeds to step Q9. In step Q9, the frame after reading the IFG data in each track, that is, the frame in which all the data of all the tracks can be read first is set as the first frame, and writing is started in the data block unit in the area specified in step Q5. Processing is performed and the process proceeds to step Q10. In step Q10, it is determined whether the counter n and the counters nT1 to nT8 have the same value. That is, one frame is made up of 8 track × 32 data blocks, and it is determined whether all 8 track × 32 data have been written in the memory designated area of the nth frame. ~ NT8
With the above process, when the data of a certain frame are all collected, the counter n and the counters nT1 to nT8 all have the same value. Then, if the counter n and the counters nT1 to nT8 have the same value, it means that the data of the nth frame has been prepared, so the process proceeds to step Q20, and the data prepared for one frame is output to the data reproducing device 6, 1 in n
(Step Q21) and the process returns to step Q9. If all the data of the nth frame are not available in step Q10, the process proceeds to step Q11. Immediately after turning on the power, n =
1, the process is performed on the first frame, and the process is performed on the continuing frames.

At step Q11, the nTth track of the track T1
It is determined whether or not the next IFG data of one frame has been detected. If so, the data of the nT1th frame of the track T1 are all complete, so the routine proceeds to step Q12. If the written area is the (p-T1) area, the (q-T1) area is designated as the area to be stored next. Conversely, if the written area is the (q-T1) area, the next The (p-T1) area is designated as the area to be memorized in, and the process proceeds to step Q13 to add 1 to the counter nT1. That is, the counter value for starting the process for the data of the frame to be input next is changed, and the data of the frame indicated by nT1 is written to the area designated in step Q12. If the IFG data next to the nT1th frame of the track T1 is not detected at step Q11, all the data of the nT1th frame of the track T1 is not complete, so the routine proceeds to step Q14.

Then, in steps Q14 to Q19, the data of the track T2 is subjected to the same processing as that of steps Q11 to Q13 for the track T1, and the same processing is also performed for the tracks T3 to T8 (not shown). For the track T8, shown in steps Q17 to Q19). If the writing of 32 pieces of data of the nT8 frame of the track T8 is not completed in step Q17, the data of the nT8 frame of the track T8 is not complete. Return to Q9.
In the present embodiment as well, as in the embodiments shown in FIGS. 4 and 5, the counters n, nT1 to nT8 do not necessarily have the number of digits capable of completely counting the number of frames.

FIG. 9 is a block diagram showing another embodiment of the present invention. Data D1 to D read by eight heads H1 to H8 from eight tracks of the magnetic tape 1.
8 is input to the delay circuits L1 to L8, and is also input to the control circuit 22. The control circuit 22 uses the same data from the heads H1 to H8, in this example, the same address data of the same frame (recorded at the same position in the tape moving direction).
The data read times are compared to determine whether the eight heads are simultaneously reading the same address data in the same frame. Then, if there is a difference in the data reading time, the lead time of the reading time by the other heads is calculated based on the reading time of the data read with the latest delay, and based on the lead time calculated for each data The delay time for delaying the output time of each data is calculated and input to the delay circuit 21. By this processing, the data output from the delay circuits L1 to L8 are simultaneously output to the data reproducing device 6 even if the head has an azimuth deviation, which should be read at the same time. Then, the data reproducing device 6 uses the data equivalent to that read in the state where there is no azimuth deviation of the head,
The necessary information, that is, the voice or the like is reproduced.

FIG. 10 is a flow chart showing an example of the processing performed by the control circuit 22 of FIG. 9, showing the processing for calculating the delay time from the difference in the data reading time by each head and inputting it to the delay circuit. Is. In step P1, the data read by the heads H1 to H8 is input and the process proceeds to P2.
In step P2, the reading time of the same address data recorded at the same position in the tape moving direction in the same frame included in the input data is measured, and the process proceeds to step P3. In Step P3, the read times of the same address data read by the heads H1 to H8 are compared, and if there is no difference in the read times, normal processing is performed without performing data delay processing or the like. If there is a difference in the read time, the process proceeds to step P4, and the lead time of the other data read time is calculated based on the read time of the address data read most late among the heads H1 to H8. The delay time for delaying the output time of the data read by the other heads is calculated from the calculation result, and the process proceeds to step P5. In step P5, the delay circuit L1 provided corresponding to each head
.. to L8, the delay time calculated for each head in step P4 is output to complete the data delay processing, and other normal operations are performed.

In this embodiment, the delay time is calculated by the difference in the read time of the address data, but the same effect can be obtained by controlling the difference in the read time of the IFG data by each head. Further, in the above embodiment, assuming that there is no change with time during data reproduction, the azimuth deviation is judged and necessary processing is performed only when the power is turned on or when the tape reproduction is started when the cassette is exchanged. The above-mentioned control circuit may be reset at a constant cycle, and azimuth deviation may be determined periodically. In the above embodiment, the tape recorder has been described as an example, but the present invention may be applied to a read-only device having no recording function.

[0027]

As described above, according to the present invention, at least two read data among the data read from the magnetic tape are compared, the delay degree between each data is judged, and the delayed data is used as a reference. Delay the data that is advancing to. Therefore, the data reading error due to the azimuth shift is compensated, and it is possible to always reproduce with the optimum sound quality or reproduce the data. Further, there is an effect that the data reading error can be compensated for the tape recorded by the recording head of the other device having the deviation of the azimuth angle.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a detailed view showing the configuration of a head.

FIG. 3 is a detailed view showing the structure of a magnetic tape.

FIG. 4 is a flowchart showing an embodiment of the present invention.

FIG. 5 is a flowchart showing an embodiment of the present invention.

FIG. 6 is a detailed diagram showing how to use the memory.

FIG. 7 is a flowchart showing an embodiment of the present invention.

FIG. 8 is a flowchart showing an embodiment of the present invention.

FIG. 9 is a block diagram showing an embodiment of the present invention.

FIG. 10 is a flowchart showing an embodiment of the present invention.

FIG. 11 is a front view showing an azimuth angle adjusting device.

[Explanation of symbols]

 1 magnetic tape 2 head unit 5 control circuit 6 data reproducing device

Claims (1)

[Claims] 1. A magnetic tape reproducing apparatus for reading data recorded on a plurality of tracks of a magnetic tape by a plurality of heads provided corresponding to each track, wherein at least two of the heads are a first and a second. Comparing the data read by the head, comparing means for judging the degree of delay between each data, and a compensating means for delaying the proceeding data based on the delayed data based on the comparison result of the comparing means. Data correction device characterized by.