Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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I TITLE OF THE INVENTION
Method for Recording Indicia for Indicating
Presence or Absence of Error in Medium After
Error Checking and Apparatus Therefor
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BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to a method for
recording information on an information record medium
having a plurality of records thereon and an apparatus
therefor.
Related Background Art
Various media such as disk, card and tape types
have been used as information record media to optically
1~ record information and read the recorded information.
Of those, a card-like optical information record medium
(optical card) is compact, light and easy to carry, and
a large demand thereof is expected as a convenient
large capacity information record medium.
Fig. 1 shows a schematic plan view of an optical
card, and Fig. 2 shows a partial enlarged view thereof.
In Fig. 1, numeral 1 denotes an optical card,
numeral 2 denotes an information track, and numeral 3
denotes a home posltion. The optical card 1 is modulated
with record information and a light beam focused into a
fine spot is scanned on the optical card so that infor-
mation is recoFded as a record pit line (information
4n4
i track) which is optically detectable. In order to
correctly record and reproduce information without
trouble such as crossing of the information traclc 2,
it is necessary to control the irradiation position of
the light beam perpendicularly to a scan direction (auto-
tracking AT). In order to irradiate the fine spot stably
in spite of warp of the optical card or mechanical
tolerance, it is necessary to control the irradiation
position of the light beam normally to the optical card
l~ (auto-focusing AF). As shown in Fig. 2, tracking tracks
5 (51' 52' ) for AT are provided between the
information trac]cs 2 (21, 22, .... ) of the optical
card 1.
Recording and reproducing methods of the optical
I card are now explained.
In Fig. 1, the light beam is initially at the
home position 3~ Then, the light beam move in a direction
D, finds an information track 2N to or from which infor-
mation is to be recorded or reproduced, and scans the
information track 2N in a direction F to record or
reproduce information.
In order to determine whether the track is a
target track or not, track number areas 6 (preformat)
which prerecord track numbers are formed on extended
lines of the tracking tracks 5 (51~ 52' ), the
recorded track number is read and the content thereof
is checked to determine whether it is the target track
or not. Alternatively, data plus a track number is
recorded on the information track 2 (21~ 2z, .... ), the
information track is reproduced and the track number is
extracted and compared with the target track number. For
example, the former method is described in our Canadian
Patent No. 1270059, issued on June 5, l990.
However, in the former method, an application is
restricted depending on the preformat. In the latter
method, since no information is written on a non-recorded
track, it is impossible to determine whether the track is
the target information track or not, and it may be
overwritten if it follows a recorded information track by
erxor.
Where the optical information record medium is a
non-er~sa~le after-record type record medium, the
recorded data is immediately reproduced, it is verified
to determine whether it is identical to the record data,
and if it is not identical, it is again-recorded in the
next in~ormation track. However, it may be possible that
an error occurs when the information is reproduced from
the information record medium. When the error occurs, it
is impossible to determine whether it is due to dust or
break in the reproduce operation or it has existed since
2S the record operation. So-called retry to repeat the
reproduction when the error occurs is usually carried out
a plurality of times
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i in the reproduce operation, and if the error still
occurs, the information is reproduced from the next
information track. However, if there are many error
tracks in the record operation, the number of times of
;~ extra retries increases and a reproduce time is extended.
SUMMAKY OF THE INVENTION
It is an object of the present invention to
provide information record method which avoids over-
0 writing and shortens a reproduce time, and apparatustherefor.
The above object of the present invention is
achieved by an information record method eomprising
the steps of reeording information in one reeord area
1~ of an information reeord medium having a plurality of
reeord areas, reprodueing the recorded information and
checking error thereof, and recording an indicia
indicating presence or absence of error at a portion
of the record area in accordance with an error check
result. An information record apparatus used for the
above method comprises means for reeording information
on an information reeord medium having a plurality of
reeord areas, means for moving the reeord means to a
reeord area to whieh information is to be reeorded,
means for reprodueing the information reeorded in the
reeord area, means for eheeking error based on the
reprodueed information, and means for recording an
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i indicia for indicating presence or absence of error at
a portion of the record area in accordance with error
check result.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 shows a schematic plan view of a
conventional optical card.
Fig. 2 shows a partial enlarged view thereof.
Fig. 3 shows a schematic plan view of an optical
card used in the present invention.
Fig. 4 shows a partial enlarged view of a
section A of Fig. 3.
Fig. 5 shows one embodiment of an information
record apparatus of the present invention.
1~ Fig. 6 shows an optical head of the information
record apparatus.
Fig. 7 shows a light beam irradiated on the
optical card.
Fig. 8 shows a photo-detector.
~0 Fig. 9 illustrates record operation to the
optical card by the information record apparatus of
the present invention.
Fig. 10A shows a locus of a light beam spot in
the record mode.
2~ Fig. 10B shows a record timing.
Fig. 11 shows a flow chart of a record operation
in one embodiment when an E mark is used.
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i Figs. 12A to 12C illustrate the E mark.
Fig. 13 shows a waveform to explain a detection
operation of the E mark.
Fig. 14 shows a flow chart for a record operation
in one embodiment when a V mark is used.
Figs. 15A and 15B show a feed device for the
optical card.
Fig. 16 shows a feed operation for the optical
card.
Fig. 17 illustrates a detection operation for a
reference track.
Fig. 18 illustrates other record operation in
the present invention, and
Fig. 19 shows a flow chart of the operation of
Fig. 18.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The embodiments of the present invention will be
explained with reference to the drawings. An optical
card is explained as an example of an information
record medium used in the present invention.
A basic structure of the optical card and a
configuration of an information recording apparatus
are explained. In the drawings, the like elements
are designated by the like numerals.
Fig. 3 shows a schematic plan view of an
optical card used in the present invention.
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Tracking tracks 5 (51~ 52~ --) f continuous
line are arranged at a constant pi~ch on the optical card
1. A data record area 4 (41~ 42~ -) for recording
information thereon is provided for each space between
the tracking tracks. Namely, the optical card 1 has data
record areas in all spaces between the tracking tracks.
As shown in Fig. 4, a G mark 7 is provided between
the tracking tracks 5_1 and 51. The G mark 7 serves to
discriminate a reference track and it is arranged by
preformat at a predetermined position on the optical
card. A medium type identification pattern 8 which is an
auxiliary data area is recorded by preformat or light
spot on a line extending from the data record area 40 on
which the G mark is provided. The medium type
identification pattern 8 indicates a type of the optical
card and information on modulation/demodulation system,
data capacity per track and total number of tracks are
recorded thereon. A format of the optical card is
described in our Japanese published Patent Application
Nos. 62-239344, 62-239345 and 63-244319.
Fig. 5 shows an embodiment of the information
recording apparatus of the present invention.
The information recording apparatus (drive) 19 is ;~
connected to a host control unit (CPU) 9, and data are
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communicated and controlled between the
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I drive 19 and the CPU 9. A microprocessing unit (MP~)
10 in the drive 19 contains a read-only memory (ROM)
and a random access memory (RAM), and primarily controls
a card feed motor 14 and a head drive motor 13 which
drives an optical head 18. An AT/AF control circuit
11 receives signals of photo-detectors 22 - 24 to
drive an AF actuator 15 and an AT actuator 16. A
modem 12 modulates a light intensity of an irradiation
optical system 17 in a record mode to record information
and demodulates the information based on the signal of
the photo-detector 23 in a reproduction mode. When the
card is inserted, the MPU 10 demodulates and discrimi-
nates the medium type identification pattern 8 of the
reference track shown in Fig. 4.
1~ Fig. 6 shows a construction of the optical head
of the information recording apparatus.
Fig. 7 shows a light beam irradiated onto the
optical card.
Fig. 8 illustrates a function of the photo-
detector.
The light beam emitted from a light source 27such as a semiconductor laser is collimated by a colli-
mater lens 28 and split into three beams by a diffraction
grating 30. Those light beams are focused by an objective
lens 26 onto the tracking tracks 51 and 52 and data
record area 41 on the optical card I to form beam
spots S1, S2 nad 53. The optical card 1 is moved in
129~
; a direction R by the motor 14 shown in Fig. 5 and scanned
by the beam spot along the tracking track. The reflected
lights of the beam spots S1, S2 and S3 again pass through
the objective lens 26, reflected by a beam splitter 20
5 and projected to the photo-detectors 22, 23 and 24 by
a focusing lens 21, which is an astigmatism system and
arranged to effect auto-focusing by a well-known
astigmatism system. The photo-detectors are arranged
as shown in Fig. 8, and the photo-detector 23 is divided
into four sections A, B, C and D as shown in Fig. 8.
In Fig. 6, numeral 29 denotes a prism which converts
a sectional distribution of the light beam emitted
from the semiconductor laser and collimated from an
ellipse to a circle, and numeral 25 denotes a mirror
which directs the light beam to the objective lens 26.
An operation to record information on the
optical card by using the above apparatus is explained.
When information is to be recorded on the data
record area 41, the beam spots S1, S2 and S3 are
irradiated to the tracking track 52' data record
area 41 and tracking track 51' respectively. ~hose
beam spots are scanned in a direction F as the optical
card 1 is moved. The reflected light from the beam
spot Sl is dlrected to the photo-detector 22 and the
reflected light from the beam spot S3 is directed to
the photo-detector 24, and the tracking signal is
detected by a three-beam method. As the beam spots
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Sl and S3 deviate from th~ tracking tracks 52 and 5~,
respectively, a di~ference is caused between light
intensities applied to the photo-detectors 22 and 24, and
the tracking signal is derived by comparing the signals
from the photo-sensing planes. The beam spots S1, S2 and S3
are moved in union normally to the scan direction ~in the
direction D in Fig. 2) by tracking means 16 shown in Fig.
5 (for example, means for driving the objective lens 26 in
a direction Z in Fig. 6) in accordance with the tracking
signal so that AT is effected. Record pits 31 are recorded
on the data record area 41 along the tracking tracks 51 and
52 by the beam spot S2. Such ~T is described in our
European Patent Publication No. 241267 dated October 14,
1987.
The operation of information recording in
accordance with the present invention is explained.
The present invention is characterized by recording
a special indicia indicating presence or absence of error
on an extended line of the information track after
verification.
The special indicia for indicating the presence or
absence of error may be recorded when the error is present
(E indicia), recorded when the error is absent (V indicia),
or E mark and V mark are selectively recorded.
, ' ::' '
A method for recording the E indicia as the
special indicia and an effec-t thereof are explained.
Fig. 9 shows the operation in the record mode
of the optical card by the information recording apparatus
of the present invention.
Fig. lOA shows a locus of a light beam spot
in the record mode, in which an ordinate represents
a velocity and F and L correspond to F and L in Fig.
7.
Fig. lOB shows a record timing. A High level
corresponds to a non-record area and a Low level
corresponds to a record area~
Fig. 11 shows a flow chart for illustrating
the record operation. A direction F corresponds to
l~ a direction of movement of a light spot.
~ eferring to Figs. 5 to lOB, the record
operation is explained in accordance with the flow
chart of Fig. 11.
In a step 100, the light spot at a point a
on the track 32 in Figs. 9, lOA and lOB is moved in
the direction F at a low speed by driving the card
feed motor 14. In a step 101, whether the E indicia
is present or absent is checked based on the output
signal of the photo-detector 23 before the light spot
reaches a point c. If the signal by the E indicia is
not produced, the light source 27 is driven by the
modem 12 in a step 102 and information is recorded
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i starting from the point c. When the information has
been recorded and the light spot reaches a point b,
the card feed motor 14 is reversed in a step 103 and
the light spot is moved in the direction L at a high
speed. The recorded informa-tion is reproduced through
the modem 12 based on the output signal of the photo-
detector 23 and the reproduced information is compared
with the record information in the MPU 10 to check an
error, in a step 104. ~fter the light spot has reached
the point c in the step 105, that is, after all data
have been reproduced, the speed of movement of the light
spot is lowered while the direction of movement is kept
unchanged, in a step 106. If an error is detected in
a step 107, a predetermined pattern or the E indicia
1~ is recorded in the record area 34 from the point d
to the point e in a step 108. The E indicia is
recorded by producing an E indicia record signal by
the MPU 10 based on the result of error check by the
MPU lO and modulating the light source 27 by the
modem 12 in accordance with the pattern. In a step
109, the head drive motor 13 is driven to move the
head to the next track 33. If no error is detected
in the step 107, no E indicia record signal is produced
by the MPU 10 and no E indicia is recorded, and the
.~5 head is moved to the track 33 in the step 109.
If the E indicia is detected in the step 101, it
means that the track 32 has information recorded
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i thereon, and no information is recorded and the head is
moved to the track 33 in the step 109. In any case,
the track is switched one after another after the
step 109 and the operation is repeated until all
information have been recorded.
In accordance with the present invention, since
recording and verification of the data and recordlng
oE the E indicia are done in one reciprocation along
one information track, the record time can be shortened.
Io As shown in Fig. lOB, the velocity in the record mode
and the velocity in the reproduce mode are different
although they may be equal.
The E indicia is basically a single bar-like
pattern as shown in Fig. 12A. However, if there is
l~ dust or defect (Fig. 12C) in a unrecorded area in
which the E indicia is to be recorded, it may be
detected as the E indicia so that even a good track
may be detected as a bad track. In order to eliminate
the above problem, the E indicia may be a multi-dot
pattern as shown in Fig. 12B so that it may be dis-
criminated from a signal due to dust or defect as
shown in Fig. 12C.
Referring to Fig. 13, when the E indicia is
detected by the photo-detector 23, the output signal
23-l of the photo-detector 23 comprises a portion b
for the E indicia and a portion c for the dust or
defect. When the output signal 23-1 is applied to
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I a signal processing circuit (not shown), for example,
a retriggerable monostable multivibrator, an output
signal Z3-la shown in Fig. 13 is produced. Since the
E indicia is the multi-dot pattern, a pulse width T
of the signal in the portion b is wider than a pulse
width T' of the signal in the portion c. By handling
the signal as the signal due to the E indicia if the
pulse width T is wider than a predetermined width,
the E indicia (Fig. 12B) can be distinguished from
the dust or defect (Fig. 12C).
The pattern of the V indicia and a method for
detecting it are similar to those for the E indicia.
When there is no E indicia in the record mode,
it means either that there is no error but the informa-
1~ tion has been recorded or that information has notbeen recorded. Accordingly, it may be difficult to
completely prevents overwriting. When the E indicia
and V indicia are selectively recorded depending on
the presence or absence of error, non-error state,
error state and non-record state can be discriminated.
In the reproduce mode, the operation when the
light spot is at the point a at the start of the
reproduction is slightly different than that when
it is at the point b. When it is at the point a,
if the signal due to the E indicia is detected before
the light spot reaches the point c, the data is not
reproduced and the track is changed at the point b
~9~40~
; to reproduce the next information track. On the other
hand, if the light spot is at the point b, the process
is carried out up -to the error check, and if the E
indicia is detected, the track is changed, whether
an error exists or not, to reproduce the next infor-
mation track. If there is an error inspite of no
detection of the E indicia, the process is retried a
predetermined number of times.
~hen a plurality of informaiton tracks are to
be continuously reproduced, even if an information
track containing an E indicia (bad track) is included,
the bad track need not be retried. Accordingly, even
if many bad tracks are included, the reproduce time
is not substantially longer than that re~uired when
l~ no bad track is included.
In accordance with the present invention,
record/reproduce time can be significantly shortened
through the simple control.
The same effect is attained when the V indicia
~0 is used instead of the E indicia.
Fig. 14 shows a flow chart for illustrating
the operation in the record mode when the V indicia
is used.
In a step 130, the light spot at the point a
on the track 32 in Figs. 9, 10A and 10B is moved in
the direction ~F at a low speed by driving the card
feed mot^r 14. In a step l~1, wh-th-r tbe V indicia
:
.
~2~34~)~
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; is present or not before the light spot reaches the
point c (detected by a position detector no-t shown
or by time measurement) is detected from -the output
signal of the photo-detector 23. If the signa~ due
to the V indicia is not produced, the light source 27
is activated by the modem 12 in a step 132 to record
information starting from the point c. When the
recording is completed and the light spot reaches
the point b, the card feed motor 14 is reversed at a
step 132 to move the light spot in the direction L at
a high speed. During the movement of the light spot
in the direction L, the recorded information is
reproduced by the modem 12 based on the output signal
of the photo-detector 23 in a step 134, and the
reproduced information is compared with the record
information in the MPU 10 to check an error. In a
step 135, after the light spot has reached the point
c, or all data have been reproduced in a step 135,
the speed of the light spot is lowered while the
direction is kept unchanged. If no error is detected
in a step 137, a predetermined pattern or the V indicia
is recorded in the record area 34 from the point _ to
the point _ in a step 138. The V indicia is recorded
by producing a V indicia record signal by the MPU 10
in accordance with a result of error check by the MPU
10 and modulating the light source 27 by the modem 12
in accordance with the pattern. In a step 139, the
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1 head drive motor 13 is energized to move the head to
the next track 33. If an error is detected in the
step 137, no V indicia record signal is produced by
the MPU 10 and no V indicia is recorded. In a step
5 139, the head is moved to the track 33. If the V
indicia is detected in the step 131, the track 32 is
a recorded track and no information is recorded
thereon. In the step 139, the head is moved to the
track 33. In any case, after the step 139, the track
is changed one after another and the operation is
repeated until all information have been recorded.
As described above, the recording and verification
of data and the recording of the V indicia are completed
in one reciprocation on one track as are done for the
E indicia, and the record tlme can be shortened. In
Fig. 10B, the speed in the record mode and the speed
in the reproduce mode are different although they may
be equal.
In the reproduce mode, the opèration when the
~0 light spot is at the point a at the start of xeproduc-
tion is slightly different than that when it is at
the point b. When it is at the point a, the data
is not reproduced if the signal due to the indicia
V is not detected before the light spot reaches the
point c, and the track is changed at the point b to
reproduce the next information track. On the other
hand, if the light spot is at the point b, the process
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is carried out up to error check, and if the V indicia is
not detected, the track is changed, whether an error is
present or not, to reproduce the next information track.
If an error is detected in spite of the detection of the V
indicia, the process is retried a predetermined number of
times.
Thus, when a plurality of information tracks are
to be reproduced continuously, even if an information track
which has no V indicia (bad track) is included, the bad
track need not be retried. Accordingly, a reproduce time
required when many bad tracks are included is not
substantially longer than that required when no bad track
is included.
Thus, the record/reproduce time can be
significantly shortened by the simple control as is done
for the E indicia. The verification of the record
information is explained in our Canadian Patent No. 1268252
dated April 2, 1991.
The operation of the information recording
apparatus up to the start of recording is explained with
reference to Figs. 3 ~ 5 and Figs. 15A - 17.
Fig. 15A shows a schematic sectional view of an
optical card feed mechanism, and Fig. 15B shows front and
plan views thereof.
Fig. 16 illustrates a method for determining
40~
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1 a home position of the optical card.
Fig. 17 illustrates a reference track detection
operation.
When the insertion of the optical card 1 into
the drive 19 is detected by a sensor not shown, the
card feed motor 14 is controlled to feed the optical
card 1 in the direction L and the optical card 1 is
fed in the direction L by a roller 35 as shown in
Figs. 15A and 15B. Numerals 38 and 39 denote rollers
for supporting the optical card. A light emitting
device 37 and a photo-sensor 36 are provided. As
shown in Fig. 15, when a leading edge f of the
optical card 1 passes through the photo-sensor 36,
a signal 36-1 of the photo-sensor 36 is High at the
1~ point f, Low when a detection hole 40 passes, and
again High at a point h after the detection hole has
passed. By measuring distances or times of f-g and
g-h by a position detector not shown, whether the
optical card has been correctly inserted or not can
be determined. If it has been correctly inserted,
the optical card 1 is fed by a predetermined distance
and stopped thereat. The stop position is the home
position 3.
If the optical card has not been correctly
inserted, the control circuit immediately reversely
drive the feed roller 35 to eject the optical card
1 and requests re-insertion of the optical card to
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an operator by buzzer or ~amp. A method for detecting
the correct insertion of the optical card is described in
our U.S. Patent No. 4829168, issued on May 9, 1989.
An operation to seek a reference track (track 00)
is then carried out. When the light spot is at the home
position 3 by the above operation, the MPU 10 drives the
head feed motor 13 to move the optical pickup 18 in the
direction D of Fig. 3. As shown in Fiy. 17, if nothing
has been recorded between the tracking tracks, an output
lo 2Z-1 of the photo-detector 22 for a light spot S1
represents a time i, and if information has been recorded
therebetween, it represents a time k. The control
circuit measures an interval for the light spot to move
across the tracking track to seek the G indicia 7, or
checks the presence or absence of the G indicia at a
predetermined point on each track while the optical card
l is fed in the direction L or F to seek the G indicia 7,
and whan the G indicia is sought, the head drive motor 13
is stopped and the optical card is returned in the
direction F. Then, it is fed in the direction L to
detect the G indicia again so that it is confirmed that
the current information track is the track 00.
After the G indicia 7 has been detected, the
optical card l is fed in the direction L (the light
~g~ 4
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; spot is moved in the direction F) and the MPU 10 reads
the medium type identification pattern 8 (Fig. 3)
recorded on the track 00. The type of medium applicable
to the information recording and reproducing apparatus
has been registered in a ROM of the MPU 10, and the
MPU 10 determines whether the inserted optical card
can be recorded and reproduced, and if it can, the
identification information of the optical card is
sent to the CPU 9, and if it cannot, the MPU 10 sends
0 "record/reproduce disable" information to the CPV 9.
When it can be recorded and reproduced, the
MPU 10 also informs to the CPU 9 that the unit is
ready. The CPU 9 responds to it to send a record
or reproduce instruction to the MPU 10. The reproduce
l~ operation is explained with reference to Fig. 9.
When the light spot is at the point a, the optical
card 1 is fed in the direction L (the light spot is
moved in the direction F), and whether the E indicia
or V indicia is detected before the light spot reaches
the point c is checked and recorded. After the light
spot has reached the point c, the demodulated data
signal from the modem 12 is stored in the RAM of the
MPU 10 and an error is checked. After all data of
one information track have been stored and error-
checked, the presence or absence of the E indiciaor V indicia in the reproduced information track is
checked based on the information stored in the RAM,
. .
.
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l and if the E indicia is absent and error is present,or if the V indicia is present and the error is present,
the card feed direction is reversed and the reproduc-
tion is retried. If the E indicia is absent and error
is absent, or if V indicia is present and error is
absent, the track is changed in preparation for the
next reproduce operation and the MPU 10 transfers the
reproduced data to the CPU 9. When the E indicia is
present or the V indicia is absent, the track is
changed whether the error is present or not to
reproduce the next track. By the E indicia or V
indicia, it is possible to immediately determine
whether a reproduction error is due to a record error
or not. As a result, the retry operation is not
l~ necessary ànd the reproduction throughput is improved.
Other embodiment of the information recording
method of the present invention is explained. Fig. 18
shows an enlarged view of a record medium plane, like
Fig. 9. As explained in Fig. 14, when information is
recorded on a track 32, if there is defect or dust on
the record medium while the light spot is moved from
a point a' to a point e', the AT is not effected and
the light spot may return to the track 32. In the
example of Fig. 18, an infinite loop of the track
32 a ~ e ~ d ~ c ~ b ~ a' -~ e ~ d may occur.
In the present embodiment, when the V indicia
is detected, the light spot is moved from the track 32
34~a
to the track 35 so that the infinite loop is avoided.
While the light spot is moved across two tracks
in the above example, it may be moved across more than
two tracks, although the movement across many tracks
5 is not desirable from a standpoint of ulitization
efficiency of the tracks.
Referring to Figs. 5 - lOB and 13, the record
operation of the present embodiment is explained with
reference to a flow chart of Fig. 19.
IO In a step 190, the light spot at the point a
on the track 3Z in Figs. 1~, lOA and lOB is moved in
the direction F at a low speed by driving the card
feed motor 14. In a step 191, whether the V indicia
is present or not before the light spot reaches the
l~ point c (detected by a position detector not shown
or by time measurement) is detected based on the
output signal of the photo-detector 23. If the signal
due to the V indicia is not detected, the light source
27 is activated by the modem 12 in a step 192 and
information is recorded starting from the point c.
When the recording is completed and the light spot
reaches the point b, the card feed motor 14 is
reversed in a step 193 to move the light spot in
the direction L at a high speed. While the light
spot is moved in the direct1on L, the information
recorded through the modem 12 is reproduced based
on the output signal of the photo-detector Z3 in a
~2~
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i step 194, and the reproduced information is compared
with the record information by -the MPU 10 to check
an error. When the light spot reaches the point c,
that is, all data have been reproduced in a step 195,
the velocity of the light spot is lowered while the
direction is kept unchanged in a step 196. If error
is not detected in a step 197, a predetermined pattern
or the V indicia is recorded in the record area 34
from the point d to the point e in a step 198.
The V indicia is recorded by producing the V indicia
record signal from the MPU 10 based on the result of
error check by the MPU 10 and modulating the light
source 27 in accordance with the pattern by the modem
12. In a step 199, the head feed motor 13 is driven
to move the head to the next track 33. When the error
is detected in the step 197, the MPU 10 does not produce
the V indicia record signal and the V indicia is not
recorded. In a step 199, the head is moved to the
track 33. If the V indicia is detected in the step
191, no information is recorded as the track 32 has
information recorded thereon, and the head is moved
to the track 35 in a step 200. In any case, the track
is changed one after another and the operation is
repeated until all information are recorded.
2~ In accordance with the present embodiment,
the infinite loop does not occur even if the AT is
not effective because of dust or defect on the track.
~Z9~04~
- 25 -
i The present invention may be applicable -to
other varlations than the illustrated embodiments.
For example, the record medium is not limited to the
optical card but it may be of any form. The present
a invention includes all such modifications without
departing from the scope of the claims.
la
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