JPS607658A - Method for correcting address of disc-like information recording medium - Google Patents

Abstract

PURPOSE:To obtain an address signal always having a correct value by correct ing the value of the address signal on the basis of the value of an address signal obtained before one rotation of a recording medium when the value of the address signal breaks the regularity corresponding to the reproducing speed. CONSTITUTION:A reproducing device 10 reproduces a disc-like information recording medium (disc) in which address signals indicating the positions of a recording program are recorded every rotation by plural times at a fixed reproducing speed. Receiving the reproduced signal testing device body 11 compares the values of plural address signals obtained every rotation of disc respectively. If a part of the plural address signals breaks the regularity, the value of the address signal obtained before one rotation of the disc is operated in accordance with the regularity and the value of the address signal obtained by the current rotation of the disc is formed to correct the error of the address signal value. Since the address signal value is corrected as shown above, an address signal having always correct value is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an address correction method for a disk-shaped information recording medium, in which when the value of an address signal breaks the regularity corresponding to the playback speed, By correcting with the value generated according to the playback speed,
An address signal with a correct value can be obtained at all times, and this address signal is used for tracking error detection to
1. To provide an address correction method for a disk-shaped information recording medium that increases the reliability of error detection. Ru.

The present applicant has previously disclosed in Japanese Patent Application No. Sho b2 252605"r and others that the main information signal and the first to third tracking control reference signals (hereinafter referred to as tracking signals) are each geometrically shaped without forming four guide grooves. A disk-shaped information recording medium that records electrode functions as changes in shape;
We propose a reproducing device that reads and reproduces the main information signal and the first to third tracking signals as changes in capacitance by scanning the main information signal and the first to third tracking signals as changes in capacitance. did. In addition, in the disc-shaped information recording medium proposed by the applicant mentioned above, a video signal, etc. is recorded as the main information signal in four fields per revolution on a spiral main track, and the recording frequency band of the main information signal is The first and second 1-racking signals rp+ and fp2, which have different frequencies and are lower in frequency than
It is switched every rotation period, and is recorded by forming a sub-track in the middle part between the above-mentioned main racks and racks that are adjacent to each other in a burst pattern corresponding to the horizontal blanking period.
At the switching connection of Pl, fP2 (in the vertical blanking period) there is a third 1-racking signal r for switching the 1-racking polarity of the 1-switching the 1-bo circuit.
p3 does not affect the main information signal J: Recorded at a level below a predetermined level.

FIG. 1 is a partially enlarged perspective view showing the reproduction state of a disc-shaped information recording medium proposed by the applicant and a reproducing needle; 1 is a disc-shaped information recording medium proposed by the applicant; This is a disc on which a color video signal or the like is frequency modulated and recorded as the main information signal. This disk 1 is placed on a turntable (not shown) and rotated synchronously with the -C turntable at high speed under the control of a motor servo circuit. On the surface of the disk 1, as shown in FIG. 1, a recording device such as a color video signal is formed by repeating a flat surface 2 and a bit 3. 1 racking signal f l)
l Recording sub 1 - rack and flat surface 2 to pitch 1 indicated by 5
By which repetition 1~rackning signal fP2 recording sub]~rack is formed and rotated in the direction of the arrow. The rotational speed of the disc 1 is 900 ppm in a device that reproduces a disc on which an NTSC color video signal is recorded.

Reference numeral 6 indicates the reproduction total 1, and an electrode 68 is vapor-deposited and fixed on the rear end surface of the J3, and the bottom shown as 6b slides on the surface of the disk 1. It is detected that the electrostatic capacitance (1) formed in the 2nd line changes in response to changes in the intermittent pit row, and this is converted into a high frequency signal.

During the manufacturing process of the above disc 1, the flat surface 2 on the surface of the disc 1 may be partially deformed into a convex or concave shape, scratches may occur on the surface of the disc 1, or there may be stains on the surface of the disc 1. 275 may cause defects such as bit 3 being buried due to snow sticking to it. During playback, when the playback needle 6 scans, for example, a convex deformed part, the playback button 6 jumps up at the convexity and is out of the surface of the disc 1 for a period of time, making it impossible to reproduce the information signal and causing a dropout of the information signal. If the playback needle 6 jumps sideways, the playback ε16 may shift to another range of 1 to 0, resulting in a tracking error.

Furthermore, when the reproduction #16 scans a concave deformed portion, a mountain portion, or a dirt-attached portion, the information signal cannot be reproduced and a gap 1- occurs, making it impossible to obtain a high-quality image.

When detecting the above-mentioned racking errors, one of the three types of address signals inserted in the vertical blanking period of the color video signal is used. Here C
1. For example, the address signal (time address) in the 18th horizontal scanning period of the vertical blanking period is shown in Figure 2 (A
), it has a 29-bit configuration, and the 4-bit lN100J framing code ■a indicates the start of the address signal.
1 does not indicate the type of address signal, line select for 2 bits 1~ (rlOJ in case of time address) - mode code Ib for 2 bits i~, mode code Ic for 2 bits i~, 13 CI of 4 bits each
) code and represents decimal numbers in units of 10 minutes, units of 1 minute f1/, units of 10 seconds, and units of 1 second.
d to I (picture number 11 corresponding to 15 tracks played in 1 second during normal playback in binary numbers of 1.4M bits), 1-bit digital bits 1 to 11 for barrier (block). It is formed.

This address signal is recorded using a pi-phase 6 system as shown in FIG. 2(B). The signal in Fig. 2 (B) is 2
It shows the base number "1ooo1ooo". However, if the signal in Figure 2 (B) is reproduced as a waveform similar to that in Figure 2 (C) due to noise generated due to effects such as dropouts during playback, this reproduced signal will become as shown in Figure 2 (D).
Iha who accepts it is caught with a bow. No. 151 in FIG. 2(D) indicates r 11000001J in binary, and the value of the address signal will be erroneously reproduced.

It is possible to confirm the presence of an error by performing a stage parity check when the number of erroneously reproduced bits is an odd number, but this cannot be confirmed when the number of erroneously reproduced bits is an even number. If the value of the address signal is incorrect, it may be determined that 1-racking is wrong even though normal 1-racking is actually being performed.
1. There was a drawback that the reliability of racking error detection was low.

The present invention eliminates the above-mentioned drawbacks, and an embodiment thereof will be explained with reference to FIG. 3 and the following figures.

FIG. 3 is a block diagram of an embodiment of a defect detection device to which the method of the present invention is applied. In the figure, reference numeral 10 denotes a disc replaying device, and this reproducing device 10 operates in response to operation signals supplied from an inspection device main body 11, which will be described later. This reproducing device 10 reproduces the disk that is the object to be inspected, and supplies the extracted color video signal VI and audio signal ALI to the monitor receiver 12. .

In addition to the color video signal ■■, the reproduction device 10 also receives a high frequency signal 4FM, a vertical synchronization signal ■S, a tracking signal Fp3. Kick signal K1. Video Mu 1/Signal VM,
Correction signals 1-IR, . . . , status signals @ST, etc. are extracted and supplied to the inspection apparatus main body 11. This high frequency signal [:M is a reproduced signal from the disk, and is a color video signal etc. which is frequency modulated and is in the tc state. The vertical synchronization signal Vs is separated and extracted from the demodulated color video signal VI, and the tracking signal Fp3 is 1z! The third tracking signal fp3, which is separated and extracted from the one-frequency signal FM, is waveform-shaped and, if any, is missing, it is generated by compensating for it. Kick signal KI is played backwards,
Special effects such as high-speed playback and still playback This is generated to perform a so-called kick that forcibly moves the playback needle 6 shown in FIG. The video mu1 signal VM is a signal for disc loading.

This is a signal that becomes 1-level when the lead-out portion is reproduced. In addition, the correction signal V R is a color image No. 5 VI4C.
When a dropout occurs, the color video signal for one horizontal scanning period (hereinafter referred to as r11-1j and A) from Trotubular 1 to A is substituted with the color video signal for the preceding 11-1 minute to generate a color video signal. This is a signal corresponding to drop error 1 to generated when correcting Vl. The status signal ST is an information signal indicating the playback state of the playback device 10, ie, forward playback, backward playback, playback speed, etc.

Next, the inspection device main body 11 will be explained. The dropout detection circuit 13 receives a correction signal 1-I from the playback device 10.
R and kick signal Kl are supplied.

Here, when the reproducing layer 6 scans, for example, a convex deformation defect on the disc 1, the reproducing layer 6 vibrates in a direction perpendicular to the surface of the disc 1 and separates from the disc surface, resulting in multiple dropouts. Correction signal 1 that is intermittent multiple times within time
-IR is generated. Even if dropout occurs multiple times within a predetermined period of time, the human eye perceives image disturbance only once. This IC, the above-mentioned drop error 1~detection circuit integrates the correction signal 1-I R and outputs the correction signal 1-I.
During the period in which R is intermittent, a drop alarm 1 to detection signal DO of 1-level is generated. However, since the dropout that occurs during kicking is unrelated to the defect, the 4-trick signal Kl
Detection of dropouts is stopped when the entry occurs. The detection signals from the drop roller 1 described above are supplied to an OR circuit 14. Further, the vertical synchronizing signal "D" is supplied to the stop-out detection circuit 15 with a correction signal "1" R2 vertical synchronizing signal "S".

A kick signal is supplied, and it is generated when the first vertical synchronizing pulse of about 11-1 minutes among the vertical synchronizing pulses of 31 to 4 minutes that falls within the vertical blanking period of the color video signal Vt drops out. Drop-up t1 to detection signal is generated from the correction signal HR and supplied to the A circuit 14. This is about the first 111 minutes of the 311 minute vertical sync pulse.
When the vertical synchronization pulse for 1 minute drops out and is replaced by the equalization pulse that precedes it, this color video signal V
The timing of the vertical synchronization signal VS, which is separated from I, is distorted and the screen shakes and flows. Ru. However, this vertical synchronization signal dropout detection circuit 15 stops its operation when the kick signal Kl is received. The drop alarm 1 to detection signal 1 O outputted from the drop alarm 1 to detection circuit 13 and the vertical synchronization signal drop alarm l to detection circuit 15 is taken out via the A circuit 14 and generated to the AND circuit 1G and drop out 1. The signal is supplied to the angle detection circuit 17.

The dropout error 1 occurrence angle detection circuit 17 is supplied with a track king signal Fp3 and a video mute signal M from the playback device @10 in addition to the dropout detection signal Do. This operation is performed during playback of the program recording period. This detection circuit 17 is a counter that is reset by the clocking signal FP3 that comes in once (q) once per rotation of the disk. Time required (1/15 seconds)
For example, the count is counted up every 8.3 milliseconds, which is 1/8, and the count value repeats ``04'' to ``7''. Send the angle detection signal to the main CPU 18.
Supplied as G. Here, for example, ■1 number 1ffj r
If the OJ is removed, there is a defect within an angular range of 45 degrees counterclockwise from the recording position of the tracking signal FP3 on the disk.

This is a dust detection circuit that detects the loss of information signal for a relatively long period of time, which is caused by ordinary dropouts, etc., and performs envelope detection of the high frequency signal FM from the playback device 10 and detects the average level of the signal. is compared with a reference level, and the clock signal supplied from the clock signal generator of the dropout occurrence angle detection circuit 17 is counted during the period when this average value level is below the reference level, and the clock signal supplied from the clock signal generator of the dropout occurrence angle detection circuit 17 is counted.
．． When a predetermined time of about 1 second is exceeded, a 1-level dust detection signal VIRUS is generated and supplied to the main CPU 18 and the AND circuit 16. The AND circuit 16 inverts the dust detection signal VIRUs, performs the AND with the dropout detection signal 0.0, extracts the dropout error 1 to the detection signal DO that occurs at times other than the dust detection signal, and sends it to the main CPU. supply

Further, the color video signal V] and the vertical synchronization signal VS from the reproduction device 10 are supplied to the addressing device 1 to the circuit 20. The address get circuit 20 takes timing according to the vertical synchronization signal VS and records it in, for example, 18'l-1 among the three types of address signals in 17H1181-1 and 201-1 within the vertical blanking period of the color video signal Vl. Then, at the time of J3 renormal playback, a time address such as the one shown in FIG. Address signal AD to sub-C
It is supplied to PU21. It should be noted that if the address get circuit built into the reproducing device 10 outputs the address signal AD, it is not necessary to provide the address get circuits 1 to 20.

Next, the address correction method performed by the sub CPtJ 21 will be explained. First, the address signal @(Y) is recorded between each vertical braking signal lυ1 on the disk, and the address signal 1 is recorded between one track from the next l to the recording position of the racking signal PiF P3. 4
The numbers of the four address signals recorded in each field are the same, and the value of the address signal of the 1-rack on the inner circumference increases by "1" from that on the outer circumference in the adjacent J-R1 to Rack. Zuru. Therefore, during normal playback, the disc 1~
Racking (+:; The values of the four address signals obtained in one rotation from the recording position of g F At speed replay 1, the address signal values are sequentially changed to "
Increase by 1".

In addition to the address signal ΔD, the sub CPU 21 is supplied with operation signals from the operation panel 22, such as video mu 1 to signal VM from the playback device 10. The sub C0U 21 executes the program shown in FIG. 4(A) when the power is turned on.

After the start button on the operation panel 22 is pressed, it is determined in step 30 whether the program recording period of the disc is being played back. When the video mu 1-signal VM reaches the 1-level and playback of the program recording period is started, the operation signal is determined in step 31.3'2 and the .chi.jIj raw speed is determined. During forward playback at 1x speed, that is, normal playback, the normal playback process in step 33 is performed, and the 5x speed playback I1.'j process in step 31 is performed. When the signal is at H level, q is Stella ■.

35, the address signal AD from the address get circuit 20
is fetched, and in step 36, the fetched address signal @AD is outputted to the main CPU 18 without being corrected.

In step 33, normal playback time 1! shown in the flowchart of FIG. 4 (13)! Ij is performed and the value of the address signal is corrected. This step 33 is executed once per rotation of the disk. In FIG. 4(B), when the tracking signal FP3 is detected in step 40, the address signal AD is reproduced four times per one rotation of the disk after the detection of the tracking signal FP3 in steps 41 and 42.
is taken in. In this step 41, the address signal AD supplied from the address get circuit 20 is
The line rake 1 to code 1b of the line rake 1 to code 1b of the following 2 pins are set to a predetermined bit pattern.
OJ) is checked, and each filler 1- of the 29-bit address signal is added modulo-2, and the result is compared with ``1'' (or ``0''). Only the address signal values determined to be correct through the two checks are sequentially stored in variables CM1 to Cfvl4.

After this, in steps 43 and 44, J3 and variables CM1 to C
The number of matching values among the values of M4 is determined, and when the matching number is 3 or 4, the process moves to step 45,
The process moves to step 46 where variables CM1 to CM4 are set.
If there is no match, the process moves to step 47. In step 46, the value of the address signal stored in the matching variable is set to the variable ΔD during the previous execution of the normal playback process.
The value of the address signal stored in 1 is compared with the increased value of 1" (1-1), and when the two match, step 45
Then, the process moves to the mismatched snowtube 48. In step 45, the values of the two or three variables that match are determined to correspond to the regularity during normal playback, and the values of these variables are transferred to the variable 01.

Step 47. ．． 48 does not correspond to the regularity of the value of the address signal taken in, so the value of the current address signal is generated by increasing the variable △D1, which is the value of the previous address signal, by ``1''. Correct the value.

After performing these steps 45°47.48 Step 4
9, the value of the variable ΔD1 is output to the main CPU 18.

Next, in step 34, flowchart 1 of FIG. 4(C) is performed.
The five-times-speed reproduction M process shown in ~ is performed to correct the value of the address signal. This step 34 is also executed once per rotation of the disk. In FIG. 4(C), when the tracking signal FP3 is detected in step 50, step 51 is executed and one address signal Δ is fetched and stored in variable CM1. At this time, when the address signal AD is taken in, the framing code is checked and the parity check is performed, and only when the check is passed, it is stored in the variable CMI, as in step 41 above. After this, in step 52, the variable CMI is
The value of the address signal stored in the variable A D 1 during the previous execution of the double-speed playback process is "2" (compared with the increased value, and if they match, step 53 r + - racking signal > -61: , The address signal in the vertical blanking period one field ahead of 3 is taken in and becomes the variable CM2.
is stored in /CC step 54, and step 52
If they do not match, the address signal is fetched in step 55 and stored in the variable CM2 in the same manner as in step 53, and then the process moves to step 56.

In step 54, the variable CM2 sets the variable CMI to "11 (
is compared to the incremented value. Here, if both names match, that is, variable CM1. If the value of the address signal stored in each CM2 increases to the value J, sr2J, and NJ of the variable AD1 and corresponds to the regularity during 5x playback, the value of the variable CM2 is changed to "2" in step 57. 1] increases the variable Δl
) 1. If the comparison in step 54 shows no match, the process moves to step 58. In addition, in step 5G, a comparison similar to that in step 53 is performed, and the variable CM2 is set to the value obtained by increasing the variable CMI by rlJ. When there is a match, step 5 is executed, and when there is no match, step 58 is executed. In each snowtube 58 and 59, the address in the vertical one ranking period that is two fields ahead of the first one-time signal Q U p 3 on the disk. The signal is taken in and stored in variable CM3, and steps 5B and 5g are performed J:
Proceed to resteps 60 and 61, respectively. In step 60, the variable CM3 is compared with the value obtained by incrementing the variable CM2 by "1", and when they match, step 62. If they do not match, the process moves to step 63 (4). Further, in step 61, a comparison similar to that in step 60 is performed, and if they match, step 64. If they do not match, the process moves to step 63 respectively.

Weird￥ICM3. If the value of the address signal stored in CM2 increases by "1" from the value of the variable CMI and corresponds to the regularity during 5x speed playback, step 64 is executed, and the value of the variable CM3 is increased by rlJ. and stored in the variable ΔD1. Further, if a match is found in the comparison at step 60, then at step 62, the 97 address signal in the vertical blanking period three fields ahead of the tracking signal "Ya" 3 on the disk is fetched and stored in variable CM4. After this, in step 65, the variable CM4 and the value obtained by increasing the variable CM3 by "1" are compared, and if they match, the variable CM3 is
．． The address signal stored in 0M4 is increased by "1" from the value of variable CM2 to 5 (corresponding to the regularity during 8-speed playback, the value of variable CM4 is changed to variable △D1 in step 6G)
is transferred and stored.

Step 60.61.65 If it is determined that there is a mismatch, that is, if the values of the three adjacent address signals obtained from one rotation of the disk are increased by 11". If it does not correspond to the regularity during 5x playback, in step 63, the variable ADI, which is the value of the previous address signal, is increased to "5". (Now generate the value of the address signal of H and correct the value of the address signal. These steps 57, 63, 84
, 66 respectively, step 67
is executed and the value of Dl is output to the main CPU 18 as a variable.

The main CPU 18 has a playback device 10 and a racking signal FP3. Video A Mu 1 ~ Signal VM.

The status signal ST is supplied, and the corrected address signal AD and operation panel are supplied from the dropout detection signal 1) O, angle detection signal ANG, garbage detection signal VIRUS, J2 sub-CL) U 21. The operation signal from 22 is supplied, and this main CI) U
18 performs operations according to the flowchart i shown in FIG.

FIG. 5 shows a flowchart of the program of the main CPU 18. The main CPU 18 performs initial settings when the power is turned on, and then operation No. 43 from the operation panel 22 is read. For example, when the 5x speed mode on the operation panel 22 is pressed, when the start button on the operation panel 22 is pressed, the process goes to step 70 (63) and depending on the state of the 5x speed mode (or 1x speed mode), 5X forward playback (or generates a control signal to instruct normal playback). This control signal is the main CP
The signal is supplied from U18 to the remote control interface circuit 23, where it is converted into a control signal for the controller, and then supplied from the remote control transmitter 24 to the playback device 1o, and the playback device 10 plays the 5x forward speed forward 1q of the disc or When the playback speed is 5x speed, the playback button 6 will lock to 51 after one revolution of the disc 1.
75 μm) is transferred to the inner periphery, but the reproducing device 10 for inspection
The width of the playback button I in the disk radius yj direction is approximately 7 μm, so the defect between this 51-rack pitch is sure to be r.
I] is scanned with raw 11, and by increasing the speed to 5 times, the inspection time is reduced to 115, or about 20 minutes, which is 5 times the speed of raw 11.

After the start of reproduction, while the read-in device of disk 1 is being reproduced, the video signal V~1 is at 1-level, so steps 71 and 72 are repeatedly executed. Thereafter, when the program recording period is reproduced (r), the video Δ mute signal VM becomes L level and step 73 is executed. In step 73, based on the playback speed instructed by the operation signal, -('77 dress number is calculated, and 1st ranking' - NO is detected. In other words, 5 times speed playback 1
The value of 〇 is r 5 J.
-J' should increase, so the previous step 73
Record the value of 0 in the real time of execution 114 and the address signal, and compare the value of the address signal AD at the real time of execution of step 73 this time to find out the difference between the real time and the value of the address signal AD. If it does not correspond, it is determined that it is a 1~rucking error, and the previous value of the address signal AD is stored as 1~rucking error occurrence start time.

The execution note of this step 73 and the processing of step 74 are performed. Here, the presence or absence of the dust detection signal VIRUS is determined, and the dust detection signal VIRLJS of H level is determined.
If so, the address signal AD and duration of the start of its occurrence are stored. Thereafter, in step 75, dropout processing to be described later is performed, and if there is a dropout error 1-, the address signal ΔD, angle detection signal ANG, and duration of the dropout occurrence start are stored. Step 7
1 to 75 are repeatedly executed unless the stop button is pressed during playback during the program recording period of the disc, and during this time the main CPU 18 supplies a display signal to the display 25 to display the address of the disc currently being played and whether or not there is garbage. , drop-out error 1 - presence/absence, drop-out], dirt, etc. are displayed. After this, the readout 1 ~ position is played back, and the operation panel 22 (
~ When the knob button is pressed, the main CPU 18 generates a control signal and ends the playback operation of the playback device 10, step 7.
6 print processing is executed. Here, step 7
Information regarding defects such as racking errors, garbage scratches, and drop-hours detected in steps 3 to 75, as well as information regarding the playback device 10 such as playback speed and playback start and end times are sent to the CPU 18 and J: reprinter 26. and the playback speed, the iTj raw start address and playback end address of the disc, and the number of defects.

1 - The address where the racking error occurred, the address and duration where the garbage error occurred, the address where the drop error occurred, the angle and duration of the error, etc. are output as a list from the printer 2 (3). The program shown in Figure 5 has now been completed.

In this way, the address signal output from the sub CPU 21 is always correct because the presence or absence of an error is detected, and if there is an error, it is corrected with a value generated according to the reproduction speed from the previous address signal. The reliability of tracking error detection using address signals is increased.

In the above embodiment, the playback speed was explained as 1x speed, 5x speed, etc., but the playback speed may be any speed. Also,
The method of the present invention may be applied to, for example, a disc playback device other than a defect inspection device, and is not limited to the above embodiment.

As described above, the address correction method for a disk-shaped recording medium according to the present invention is a method of correcting a disk-shaped information recording medium in which an address signal indicating the position of a recording program is recorded multiple times in one rotation in a spiral manner. 1 of the recording medium.
The values of a plurality of address signals obtained for each rotation are compared, and when some of the plurality of address signals break the regularity corresponding to the playback speed, the value of the address signal before one revolution of the recording medium is determined. is calculated according to the regularity to generate the value of the address signal for the current one revolution of the recording medium, and in order to compensate for errors in the value of the address signal, the value of the address signal is Even if the value is incorrect, the value of the address signal is corrected to the correct value, and this corrected address signal is used for 1 to racking error detection to increase the reliability of 1 to racking error detection. It has features such as the ability to

[Brief explanation of the drawing]

Figure 1 is a partially enlarged perspective view showing the playback state of the disk-shaped information recording medium and playback button proposed earlier by the applicant, and Figure 2 (A
) to (D) are diagrams for explaining the structure of address signals and errors in address signals, FIG. 3 is a block system diagram of an embodiment of a device to which the method of the present invention is applied, and FIG. 4 (△) −(
C) is a flowchart of an embodiment of the method of the present invention, and FIG. 5 is a flowchart of an embodiment of a program executed by the main CPU of the apparatus shown in FIG. 1... Disc-shaped information recording medium (disc), 6...
Playback button, 10...Playback device, 11...Inspection device main body, 12...Monitor receiver, 13...Do]21 tube out detection circuit, 14...OR circuit, 15...Vertical Synchronous signal dropout detection circuit, 17... Dropout occurrence angle detection circuit, 18... Main CI) U, 1
9... Garbage (= J detection circuit, 20... Address get circuit, 21... SubCPtJ, 22... Operation panel, 23... Remote control interface circuit, 24...
...Remote control transmitter, 25...Display, 26...Printer, 30~36°40~67.70~76...Step. Figure 4Figure 4- (B) Figure 5

Claims (1)

[Claims] A disc-shaped information recording medium in which an address signal indicating the position of a recording program is recorded multiple times per revolution on a spiral track is reproduced at a constant reproduction speed, and a plurality of address signals are obtained each time the recording medium rotates. and when some of the plurality of address signals break the regularity corresponding to the playback speed, calculate the value of the address signal before one rotation of the recording medium according to the regularity. 1. A method for correcting an address for a disk-shaped information recording medium, characterized in that the value of an address signal for one current revolution of the recording medium is generated, and errors in the value of the address signal are corrected.