CA1268252A - Information recording method - Google Patents
Information recording methodInfo
- Publication number
- CA1268252A CA1268252A CA000506585A CA506585A CA1268252A CA 1268252 A CA1268252 A CA 1268252A CA 000506585 A CA000506585 A CA 000506585A CA 506585 A CA506585 A CA 506585A CA 1268252 A CA1268252 A CA 1268252A
- Authority
- CA
- Canada
- Prior art keywords
- information
- recording
- recorded
- during
- track
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
- G11B20/10—Digital recording or reproducing
- G11B20/18—Error detection or correction; Testing, e.g. of drop-outs
- G11B20/1879—Direct read-after-write methods
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B19/00—Driving, starting, stopping record carriers not specifically of filamentary or web form, or of supports therefor; Control thereof; Control of operating function ; Driving both disc and head
- G11B19/02—Control of operating function, e.g. switching from recording to reproducing
- G11B19/04—Arrangements for preventing, inhibiting, or warning against double recording on the same blank or against other recording or reproducing malfunctions
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B27/00—Editing; Indexing; Addressing; Timing or synchronising; Monitoring; Measuring tape travel
- G11B27/36—Monitoring, i.e. supervising the progress of recording or reproducing
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/002—Recording, reproducing or erasing systems characterised by the shape or form of the carrier
- G11B7/0033—Recording, reproducing or erasing systems characterised by the shape or form of the carrier with cards or other card-like flat carriers, e.g. flat sheets of optical film
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/004—Recording, reproducing or erasing methods; Read, write or erase circuits therefor
- G11B7/0045—Recording
Abstract
ABSTRACT OF THE DISCLOSURE
The information recording method of the present invention comprises steps of recording information on a recording medium by a recording head during forward movement, reading the information recorded during the forward movement in the opposite sequence to the recording sequence during backward movement, and checking if the information has been correctly written or not based on the information read during the backward movement.
The information recording method of the present invention comprises steps of recording information on a recording medium by a recording head during forward movement, reading the information recorded during the forward movement in the opposite sequence to the recording sequence during backward movement, and checking if the information has been correctly written or not based on the information read during the backward movement.
Description
~L2~;8Z5~
The present invention relates to a recording method for verifying if information has b~een correctly recorded in an apparatus which records and reproduces information by a relative linear reciprocal movement between the recording and reproducing apparatus and a recording medium. Recently, information has been optically or magnetically recorded by relatively and linearly reciprocating a write unit of the recording and reproducing apparatus (hereinafter called a recording head) relative to a card-like recording medium.
In this case, it is important to rapidly verify if the information has been correctly recorded after write operation.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an information recording method which reads information recorded on a recording medium to verify it.
It is another object of the present invention to provide an information recording method which requires a short recording time in spite of verification reading.
The information recording method of the present invention comprises steps of recording information on a recording medium by a recording head during forward ,~,,0~, ~L2~ S~
,~
1 movement, reading the information recorded during the forward movement in the opposite sequence to the recording sequence during backward movement, and checking if the information has been correctly written 5 or not based on the information read during the back-ward movement.
In the information recording method of the present invention, when the information racording medium is made of an unrewritab:Le medium and an information track has been determined to include information recorded incorrectly, an indicia indicating that the track has the information incorrectly recorded and need not be reproduced in a reproducing operation may be recorded on the recording medium. The in~icia may be recorded on an extended line of the track on the recording medium. By recording such an indicia, it is immediately determined in the reproducing operation that the track need not be read.
In the information recording method of the present invention, there are various methods to verify if the information has been correctly recorded or not.
In a first method, a data to be recorded and a data read from the recorded track are compared bit by bit.
In a second method, an error check code such as a cyclic redundancy check code is added to an end of a data to be recorded and they are recorded on the recording medium, and in the verification step, an error is 12~325~
I checked based on the reproduced data and the error check code. More specifically, a data U(x) including a data to be recorded and an error check code is selected such that it is always divided by a ~eneration polynominal G(x) without residue. If there is not recording error, the data U(x) reproduced from the recording medium can be divided by the generation polynominal G(x) without residue, but if an error is included during recording operation, a data U'(x) reproduced from the recording medium cannot be divided by G(x) without residual.
In this manner, any error during the recording operation can be detected. In a third method, an error correction code such as Reed-Solomon code is added to the data to be recorded and they are recorded, and in the verifica-tion step, an error is corrected based on the read dataand the error correction code, and an error flag for indicating whether the correction was made or not is set. If an error which is beyond the correction ability is included in the recording operation, the error flag indicates that the correction was not made so that incorrect recording is indicated. In the following description of an embodiment, the first method is described.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 illustrates a prior art information recording method, _ 4 _ ~ 5~
Fig. 2 illustrates an information recording method of the present invention.
Fig. 3 shows an embodiment of an optical information recording and reproducing apparatus in accordance with the present invention, and Figs. 4A, 4B and 4C show another embodiment of the information recording method of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Fig. 1 shows a technique to verify if the information has been correctly recorded or not. Numeral 1 denotes an information track on a recording medium on which the information is to be recorded, numeral 2 represents a relative movement direction of a recording head to the recording medium in writing operation, and numeral 3 represents a relative movement direction of the recording head relative to the recordiny medium in a period between the writing operation and information read operation for verifying the recorded information. When the recording head is moved in the direction 3, the writing operation and the reading operation are not performed. The head movement in this period is called an idling movement.
Numeral 4 represents a relative movement direction of the recording head relative to the recording medium when the recorded information is verified, and numeral 5 represents a relative movement direction of the recording head relative to the recording medium when the recording head `~s'; `.'~
_ 5 _ ~ 52 is returned to a home position is preparation to the next writing operation. In the writing operation which uses such a record check method, two times o-E relative movement between the recording head and the recording medium are required to record information on one information track and two times of idling movement: are performed during the two times of reciprocal movement. Accordingly, recording and verification read times are long.
Fig. 2 illustrates a method of the present invention.
Numeral 1 denotes an information track, numeral 6 represents a relative movement direction of a recording head relative to a recording medium during a recording operation, and numeral 7 represents a relative movement direction of the recording head relative to the recording medium during a verification operation. As shown in Fig.
The present invention relates to a recording method for verifying if information has b~een correctly recorded in an apparatus which records and reproduces information by a relative linear reciprocal movement between the recording and reproducing apparatus and a recording medium. Recently, information has been optically or magnetically recorded by relatively and linearly reciprocating a write unit of the recording and reproducing apparatus (hereinafter called a recording head) relative to a card-like recording medium.
In this case, it is important to rapidly verify if the information has been correctly recorded after write operation.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an information recording method which reads information recorded on a recording medium to verify it.
It is another object of the present invention to provide an information recording method which requires a short recording time in spite of verification reading.
The information recording method of the present invention comprises steps of recording information on a recording medium by a recording head during forward ,~,,0~, ~L2~ S~
,~
1 movement, reading the information recorded during the forward movement in the opposite sequence to the recording sequence during backward movement, and checking if the information has been correctly written 5 or not based on the information read during the back-ward movement.
In the information recording method of the present invention, when the information racording medium is made of an unrewritab:Le medium and an information track has been determined to include information recorded incorrectly, an indicia indicating that the track has the information incorrectly recorded and need not be reproduced in a reproducing operation may be recorded on the recording medium. The in~icia may be recorded on an extended line of the track on the recording medium. By recording such an indicia, it is immediately determined in the reproducing operation that the track need not be read.
In the information recording method of the present invention, there are various methods to verify if the information has been correctly recorded or not.
In a first method, a data to be recorded and a data read from the recorded track are compared bit by bit.
In a second method, an error check code such as a cyclic redundancy check code is added to an end of a data to be recorded and they are recorded on the recording medium, and in the verification step, an error is 12~325~
I checked based on the reproduced data and the error check code. More specifically, a data U(x) including a data to be recorded and an error check code is selected such that it is always divided by a ~eneration polynominal G(x) without residue. If there is not recording error, the data U(x) reproduced from the recording medium can be divided by the generation polynominal G(x) without residue, but if an error is included during recording operation, a data U'(x) reproduced from the recording medium cannot be divided by G(x) without residual.
In this manner, any error during the recording operation can be detected. In a third method, an error correction code such as Reed-Solomon code is added to the data to be recorded and they are recorded, and in the verifica-tion step, an error is corrected based on the read dataand the error correction code, and an error flag for indicating whether the correction was made or not is set. If an error which is beyond the correction ability is included in the recording operation, the error flag indicates that the correction was not made so that incorrect recording is indicated. In the following description of an embodiment, the first method is described.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 illustrates a prior art information recording method, _ 4 _ ~ 5~
Fig. 2 illustrates an information recording method of the present invention.
Fig. 3 shows an embodiment of an optical information recording and reproducing apparatus in accordance with the present invention, and Figs. 4A, 4B and 4C show another embodiment of the information recording method of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Fig. 1 shows a technique to verify if the information has been correctly recorded or not. Numeral 1 denotes an information track on a recording medium on which the information is to be recorded, numeral 2 represents a relative movement direction of a recording head to the recording medium in writing operation, and numeral 3 represents a relative movement direction of the recording head relative to the recordiny medium in a period between the writing operation and information read operation for verifying the recorded information. When the recording head is moved in the direction 3, the writing operation and the reading operation are not performed. The head movement in this period is called an idling movement.
Numeral 4 represents a relative movement direction of the recording head relative to the recording medium when the recorded information is verified, and numeral 5 represents a relative movement direction of the recording head relative to the recording medium when the recording head `~s'; `.'~
_ 5 _ ~ 52 is returned to a home position is preparation to the next writing operation. In the writing operation which uses such a record check method, two times o-E relative movement between the recording head and the recording medium are required to record information on one information track and two times of idling movement: are performed during the two times of reciprocal movement. Accordingly, recording and verification read times are long.
Fig. 2 illustrates a method of the present invention.
Numeral 1 denotes an information track, numeral 6 represents a relative movement direction of a recording head relative to a recording medium during a recording operation, and numeral 7 represents a relative movement direction of the recording head relative to the recording medium during a verification operation. As shown in Fig.
2, since the verification reading operation is performed immediately after the recording operation, a signal is read out on the opposite time axis to that of the recording operation, and the recording and the verification are performed in one time of reciprocation of the recording head. Accordingly, the idling movement time of the head is saved and the recording and verification times can be reduced.
The signal read out in the verification operation is of the opposite sequence to that of the signal I applied to the recording head during the recording operation. Accordingly, it is advisable to read out the signal from memory means in the opposite sequence to the signal sequence applied in the recording operation, when the reproduced signal is compared with the recording signal during the verification operation.
In general, it is advisable that the signal is read from the information trac]c of the recording medium in the verification operation such that the reproduced signal can be used as it is. If the signal is read from the memory means in the opposite sequence on the time axis and it is recorded, the signal read during the verifi-cation operation can be used without reversing the sequence.
Fig. 3 shows one embodiment of an optical information recording and reproducing apparatus in accordance with the present invention. Numeral 11 denotes a central processing unit (CPU) which controls an overall operation of the recording and reproducing apparatus, numeral 12 denotes a card-like optical recording medium (optical card), numeral 13 denotes-an optical head for irradiating a light beam to the optical card 12 to optically record and reproduce information, numeral 14 denotes drive means for reciprocating a shattle unit (not shown) on which the optical card 12 is mounted in a direction of an arrow, numeral 15 denotes main memory means which stores information to be written into the optical card 12 ~8~5~
1 such as a personal computer, and numeral 16 denotes an address type memory which can store one information track line of record signal. The signals stored in the memory 16 can be read eithex forwardly or backwardly.
Numeral 17 denotes a compare circuit.
In a recording operation, one information track line of record signal is sent to the address type memory 16 and stored therein in response to an instruction from the CPU 11. Then, the one line of record signal is backwardly read from the memory 15 by a signal from the CPU 11. Thus, the signal which is reversed on a time axis is applied to the optical head 13 to intensity-modulate a semiconductor laser light source (not shown) of the optical head 13. In synchronism therewith, the drive circuit 14 is activated by a signal from the CPU
11 so that information is recorded on an information track of the optical card 12 by the modulated light beam from the optical head 13 while the optical card 12 is driven in the direction of the arrow A. At the end of the recording operation, the drive circuit 14 back-wardly drives the optical card 12 in the direction of the arrow B by a signal from the CPU 11. In synchronism therswith, the optical head 13 reproduces the information which has been recorded on the information track during the forward movement, and the reproduced signal is sent to the compare circuit 17. In synchronism therewith, a signal from the CPU 11 is applied to the memory 16 so ~ ~i8;~5~
l that the one track of record signal stored in the memory 16 is forwardly read out and applied to the compare circuit 17. The signal read from the memory 16 and the signal read from the optical head 13 are compared by the compare circuit 17. If the information has been correctly recorded, the signal from the compare circuit 17 is applied to the CPU 11 so that the record signal in the memory 16 is erased by an instruction from the CPU 11 and a new one line of record signal is sent to the memory 16 and stored therein by a signal supplied from the CPU 11 to the main memory means 15. If the compare circuit 17 detects that the information has not been correctly recorded, the signal from the compare circuit 17 is sent to the CPU 11 and the recording and verification operations are repreated.
A relative speed between the optical head 13 and the optical card 12 in the verification operation is higher than a relative speed between the optical head 13 and the optical card 12 in the recording operation, because a light intensity of the optical head 13 in the verification operation may be lower than that in the recording operation. Thus, in the verification operation, the light intensity from the optical head 13 is selected to be lower than that in the recording operation.
The record signal to be applied to the optical head 13 in the recording operation and the record operation to be applied to the compare circuit 17 in i8~52 g 1 the verification operation may be generated by software or hardware.
In Fig. 3, the optical head 13 may be one of various known devices such as optical disk and compact disk, and detailed explanation thereof is omitted here.
Figs. 4A, 4B and 4C show another embodiment of the information recording methocl of the present invention.
In the present embodiment, information on two adjacent information tracks are simultaneously reproduced by two independent light beams.
In Fig. 4A, numerals 21, 22, 23 and 24 denote information tracks, numerals 21-0, 22-0, 23-0 and 24-0 denote record paths, numerals 21-1 and 23-1 denote return paths after recording, numerals 21-2, 22-2, 23-2 lS and 24-2 denotes verification paths, and arrows represent relative movement direction of a head to a recording medium. The record paths, return paths and verification paths are shown separately for a purpose of illustration although they are actually on one line, that is, on an information track. The head is backwardly moved on the information track 21 at the end of the return path 21-1 for the previous track, and in the record path 21-0, the original information is recorded on the information track 21 in the reverse arrangement. At the end of the recording onto the information track 21, the direction of the head movement is again reversed, and in the verification path 21-2, the recorded information is 1~ ~8~
I verified and the head is moved to the information track 22.
Then, in the record path 22-0, the original information is recorded on the :information track 22 in 5 the revexse arrangement. At the end of the recording operation, the direction of the head movement is reversed. In the verification path 22-2, at the end of the verification operation, the head is moved to the information track 23.
In the subsequent sequences, odd numbered tracks are identical to the track 21, and the even numbered tracks are identical to the track 22. In the odd numbered track, there is the return path but the even numbered track does not need the return path. In any information track, the relative speed between the head and the card in the verification operation is essentially equal to that in the reproducing operation.
Fig. 4B shows ~rrangement of information recorded on the information tracks. Numerals 21-3, 22 3, 23-3 and 24-3 denote arrangement of information on the information tracks 21 to 24, respectively. They are opposite to the directions of the record paths 21-0 to 24-0 and of the same direction to the verification paths 21-2 to 24-2. As a result, any special process is required in processing the signal produced in the verification operation.
Fig. 4C illustrates simultaneous reading of two ~i8~5~
I tracks. Numerals 21-4, 22-4, 23-4 and 24-4 represent directions of the reproduction paths for the information tracks 21, 22, 23 and 24, respectively. In the reproducing operation, the information trac]cs 21 and 22 are reproduced in pair, and the information tracks 23 and 24 are reproduced in pair. As seen from Fig. 4C, the directions 21-4 to 24-4 of the reproduction paths in the respective tracks are same as the arrangement of the information recorded on the information tracks. Accordingly, no special process is required in the reproduction operation.
In the present embodiment, the return path in which no information is processed occurs once for every two tracks. Thus, a total verification time can be reduced over the previous embodiment.
If the relative speed between the head and the recording medium in the verification operation is equal to that in the reproducing operation, a circuit for reproducing the information can be shared.
In the embodiment shown in Fig. 4, two tracks are simultaneously read and the arrangement of the information is reversed for every two tracks. The larger the number of tracks which are simultaneously read is, the smaller is the number of times of idling movement and the more is the total time for recording and verification reduced. When n tracks are simultaneously read and the arrangement of information is reversed for every n tracks, the idling movement occurs once for every n tracks.
The signal read out in the verification operation is of the opposite sequence to that of the signal I applied to the recording head during the recording operation. Accordingly, it is advisable to read out the signal from memory means in the opposite sequence to the signal sequence applied in the recording operation, when the reproduced signal is compared with the recording signal during the verification operation.
In general, it is advisable that the signal is read from the information trac]c of the recording medium in the verification operation such that the reproduced signal can be used as it is. If the signal is read from the memory means in the opposite sequence on the time axis and it is recorded, the signal read during the verifi-cation operation can be used without reversing the sequence.
Fig. 3 shows one embodiment of an optical information recording and reproducing apparatus in accordance with the present invention. Numeral 11 denotes a central processing unit (CPU) which controls an overall operation of the recording and reproducing apparatus, numeral 12 denotes a card-like optical recording medium (optical card), numeral 13 denotes-an optical head for irradiating a light beam to the optical card 12 to optically record and reproduce information, numeral 14 denotes drive means for reciprocating a shattle unit (not shown) on which the optical card 12 is mounted in a direction of an arrow, numeral 15 denotes main memory means which stores information to be written into the optical card 12 ~8~5~
1 such as a personal computer, and numeral 16 denotes an address type memory which can store one information track line of record signal. The signals stored in the memory 16 can be read eithex forwardly or backwardly.
Numeral 17 denotes a compare circuit.
In a recording operation, one information track line of record signal is sent to the address type memory 16 and stored therein in response to an instruction from the CPU 11. Then, the one line of record signal is backwardly read from the memory 15 by a signal from the CPU 11. Thus, the signal which is reversed on a time axis is applied to the optical head 13 to intensity-modulate a semiconductor laser light source (not shown) of the optical head 13. In synchronism therewith, the drive circuit 14 is activated by a signal from the CPU
11 so that information is recorded on an information track of the optical card 12 by the modulated light beam from the optical head 13 while the optical card 12 is driven in the direction of the arrow A. At the end of the recording operation, the drive circuit 14 back-wardly drives the optical card 12 in the direction of the arrow B by a signal from the CPU 11. In synchronism therswith, the optical head 13 reproduces the information which has been recorded on the information track during the forward movement, and the reproduced signal is sent to the compare circuit 17. In synchronism therewith, a signal from the CPU 11 is applied to the memory 16 so ~ ~i8;~5~
l that the one track of record signal stored in the memory 16 is forwardly read out and applied to the compare circuit 17. The signal read from the memory 16 and the signal read from the optical head 13 are compared by the compare circuit 17. If the information has been correctly recorded, the signal from the compare circuit 17 is applied to the CPU 11 so that the record signal in the memory 16 is erased by an instruction from the CPU 11 and a new one line of record signal is sent to the memory 16 and stored therein by a signal supplied from the CPU 11 to the main memory means 15. If the compare circuit 17 detects that the information has not been correctly recorded, the signal from the compare circuit 17 is sent to the CPU 11 and the recording and verification operations are repreated.
A relative speed between the optical head 13 and the optical card 12 in the verification operation is higher than a relative speed between the optical head 13 and the optical card 12 in the recording operation, because a light intensity of the optical head 13 in the verification operation may be lower than that in the recording operation. Thus, in the verification operation, the light intensity from the optical head 13 is selected to be lower than that in the recording operation.
The record signal to be applied to the optical head 13 in the recording operation and the record operation to be applied to the compare circuit 17 in i8~52 g 1 the verification operation may be generated by software or hardware.
In Fig. 3, the optical head 13 may be one of various known devices such as optical disk and compact disk, and detailed explanation thereof is omitted here.
Figs. 4A, 4B and 4C show another embodiment of the information recording methocl of the present invention.
In the present embodiment, information on two adjacent information tracks are simultaneously reproduced by two independent light beams.
In Fig. 4A, numerals 21, 22, 23 and 24 denote information tracks, numerals 21-0, 22-0, 23-0 and 24-0 denote record paths, numerals 21-1 and 23-1 denote return paths after recording, numerals 21-2, 22-2, 23-2 lS and 24-2 denotes verification paths, and arrows represent relative movement direction of a head to a recording medium. The record paths, return paths and verification paths are shown separately for a purpose of illustration although they are actually on one line, that is, on an information track. The head is backwardly moved on the information track 21 at the end of the return path 21-1 for the previous track, and in the record path 21-0, the original information is recorded on the information track 21 in the reverse arrangement. At the end of the recording onto the information track 21, the direction of the head movement is again reversed, and in the verification path 21-2, the recorded information is 1~ ~8~
I verified and the head is moved to the information track 22.
Then, in the record path 22-0, the original information is recorded on the :information track 22 in 5 the revexse arrangement. At the end of the recording operation, the direction of the head movement is reversed. In the verification path 22-2, at the end of the verification operation, the head is moved to the information track 23.
In the subsequent sequences, odd numbered tracks are identical to the track 21, and the even numbered tracks are identical to the track 22. In the odd numbered track, there is the return path but the even numbered track does not need the return path. In any information track, the relative speed between the head and the card in the verification operation is essentially equal to that in the reproducing operation.
Fig. 4B shows ~rrangement of information recorded on the information tracks. Numerals 21-3, 22 3, 23-3 and 24-3 denote arrangement of information on the information tracks 21 to 24, respectively. They are opposite to the directions of the record paths 21-0 to 24-0 and of the same direction to the verification paths 21-2 to 24-2. As a result, any special process is required in processing the signal produced in the verification operation.
Fig. 4C illustrates simultaneous reading of two ~i8~5~
I tracks. Numerals 21-4, 22-4, 23-4 and 24-4 represent directions of the reproduction paths for the information tracks 21, 22, 23 and 24, respectively. In the reproducing operation, the information trac]cs 21 and 22 are reproduced in pair, and the information tracks 23 and 24 are reproduced in pair. As seen from Fig. 4C, the directions 21-4 to 24-4 of the reproduction paths in the respective tracks are same as the arrangement of the information recorded on the information tracks. Accordingly, no special process is required in the reproduction operation.
In the present embodiment, the return path in which no information is processed occurs once for every two tracks. Thus, a total verification time can be reduced over the previous embodiment.
If the relative speed between the head and the recording medium in the verification operation is equal to that in the reproducing operation, a circuit for reproducing the information can be shared.
In the embodiment shown in Fig. 4, two tracks are simultaneously read and the arrangement of the information is reversed for every two tracks. The larger the number of tracks which are simultaneously read is, the smaller is the number of times of idling movement and the more is the total time for recording and verification reduced. When n tracks are simultaneously read and the arrangement of information is reversed for every n tracks, the idling movement occurs once for every n tracks.
Claims (10)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS :
1. A method of recording information on a recording medium, comprising the steps of: moving the medium and a reading/recording head relative to each other in a first direction; operating the head to record first information on a first track on the medium during said movement in the first direction; moving the medium and the head relative to each other in a second direction opposite to the first direction;
operating the head to read the information on the first track during said movement in the second direction; verifying whether or not the first information has been correctly recorded on the first track on the basis of the information read during the reading step; and repeating the above steps for a second track on the medium selectively for second information and for the first information in dependence upon whether or not the first information is verified as correct.
operating the head to read the information on the first track during said movement in the second direction; verifying whether or not the first information has been correctly recorded on the first track on the basis of the information read during the reading step; and repeating the above steps for a second track on the medium selectively for second information and for the first information in dependence upon whether or not the first information is verified as correct.
2. A method according to claim 1, further comprising the step of recording an indication on the information recording medium for indicating the result of said verification step.
3. A method according to claim 1 or 2 wherein said verification step compares the first information and the information read during the reading step, bit by bit, to verify if the information has been correctly recorded.
4. A method according to claim 1 or 2, wherein an error check code is included in the first information, and said verification step checks if an error has occurred in the recording operation based on the error check code.
5. A method according to claim 1, wherein an error correction code is included in the first information, and during the verification step the information is verified as correct if any errors in the information reproduced during movement in the second direction can be corrected on the basis of the error correction code.
6. A method according to claim 2, wherein the head records and reads information by means of a light beam, the relative speed between the light beam and the recording medium during the reading step being greater than that during the recording step.
7. A method according to claim 1, wherein the first information comprises a series of ordered bits, the series being recorded in reverse order during the recording step.
8. A method according to claim 1, wherein a plurality of tracks are recorded, and the reading steps for the plurality of tracks are performed simultaneously.
9. A method according to claim 2, wherein said indication is recorded for indicating that the information has not been correctly recorded if such is determined in said verification step.
10. A method according to claim 2, wherein said indication is recorded on an extended line of the track on the recording medium, the information being recorded along the track.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8184485A JPS61240408A (en) | 1985-04-17 | 1985-04-17 | Recognising method for record information |
| JP81844/1985 | 1985-04-17 | ||
| JP8526085A JPS61243991A (en) | 1985-04-21 | 1985-04-21 | Information recording and reproducing method |
| JP85260/1985 | 1985-04-21 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1268252A true CA1268252A (en) | 1990-04-24 |
Family
ID=26422842
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000506585A Expired CA1268252A (en) | 1985-04-17 | 1986-04-14 | Information recording method |
Country Status (5)
| Country | Link |
|---|---|
| CA (1) | CA1268252A (en) |
| CH (1) | CH672856A5 (en) |
| DE (1) | DE3612815A1 (en) |
| FR (1) | FR2580850B1 (en) |
| GB (1) | GB2175123B (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4872154A (en) * | 1986-09-22 | 1989-10-03 | Canon Kabushiki Kaisha | Method for recording indicia for indicating presence or absence of error in medium after error checking and apparatus therefor |
| JPH0828046B2 (en) * | 1987-01-30 | 1996-03-21 | オリンパス光学工業株式会社 | Data recording method on card-shaped recording medium |
| CA1302563C (en) * | 1987-03-31 | 1992-06-02 | Yutaka Ogasawara | Information recording method and apparatus for re- recording information on track positioned at least two tracks ahead when abnormality of tracking servo is detected |
| JPH087948B2 (en) * | 1987-12-28 | 1996-01-29 | キヤノン株式会社 | Information recording and playback method |
| JPH02192077A (en) * | 1989-01-19 | 1990-07-27 | Sharp Corp | Data recording / reproducing device |
| JP2593721B2 (en) * | 1990-01-08 | 1997-03-26 | 松下電器産業株式会社 | Information recording / reproducing device |
| JP3020758B2 (en) * | 1992-09-24 | 2000-03-15 | キヤノン株式会社 | Optical information recording / reproducing device |
| EP0731455A3 (en) * | 1995-03-06 | 1997-01-22 | Canon Kk | Optical information recording and reproducing apparatus and method |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3582627A (en) * | 1969-06-16 | 1971-06-01 | Burroughs Corp | Automatic accounting machine |
| US3771143A (en) * | 1972-06-01 | 1973-11-06 | Burroughs Corp | Method and apparatus for providing alternate storage areas on a magnetic disk pack |
| JPS5061937A (en) * | 1973-09-29 | 1975-05-27 | ||
| US3918027A (en) * | 1974-06-24 | 1975-11-04 | Honeywell Inf Systems | Scanning and error checking apparatus for address development utilizing symmetric difference encoded data structure |
| JPS6016027B2 (en) * | 1977-11-18 | 1985-04-23 | ソニー株式会社 | time code reader |
| JPS60370A (en) * | 1983-06-16 | 1985-01-05 | Victor Co Of Japan Ltd | Method and appratus for testing defect of disc-like information recording medium |
| US4685005A (en) * | 1983-07-18 | 1987-08-04 | International Business Machines Corporation | Two-module-read, read-after-write, bi-directional tape drive |
-
1986
- 1986-04-14 CA CA000506585A patent/CA1268252A/en not_active Expired
- 1986-04-16 FR FR8605450A patent/FR2580850B1/en not_active Expired - Lifetime
- 1986-04-16 DE DE19863612815 patent/DE3612815A1/en not_active Ceased
- 1986-04-17 GB GB8609393A patent/GB2175123B/en not_active Expired
- 1986-04-17 CH CH155186A patent/CH672856A5/fr not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| GB2175123B (en) | 1989-04-26 |
| FR2580850A1 (en) | 1986-10-24 |
| DE3612815A1 (en) | 1986-10-23 |
| GB8609393D0 (en) | 1986-05-21 |
| GB2175123A (en) | 1986-11-19 |
| FR2580850B1 (en) | 1994-02-18 |
| CH672856A5 (en) | 1989-12-29 |
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Legal Events
| Date | Code | Title | Description |
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| MKEX | Expiry |