JPS62140287A - Reproducing method for information record carrier - Google Patents

Abstract

PURPOSE:To access a target information track accurately at a high speed by providing a readout area so that even part of each information adjacent track is image-formed on a sensor array. CONSTITUTION:A band 203, adjacent bands 203a and 203b, information tracks 21, 21a, and 21b of the respective bands, and areas 202, 202a, and 202b for information track separation are formed in the recording area of an optical card. For example, a CCD which has 512 cells is used as a linear sensor array 10 and a read area 208 is so set that part of the tracks 21a and 21b adjoining to the information track 21 to be read is also image-formed on the sensor array 10. Consequently, when the array 10 is scanned in the area 208 as shown by an arrow B, information of part of the track 21a is used to extract a reproduced clock, with which recording information of the track 21 is reproduced from the detection point of the area 202 to detect the area 202b, thereby stopping information reproducing operation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for reproducing information recorded on an information record carrier. The present invention is suitably applied, for example, to information reproduction using optical means.

[Background of the invention]

In recent years, information has been reproduced using optical information recording carriers such as optical files and compact discs. Furthermore, recently, information reproduction using card-shaped optical information recording carriers (hereinafter referred to as optical cards), which are more portable than these record carriers and have a relatively large capacity, has begun to attract attention. There is.

FIG. 9 is a schematic plan view showing an example of the recording format of an optical card.

In the figure, a recording area 2 is provided on an optical card 1 which is a record carrier, and the recording area 2 is formed by a plurality of bands 3 arranged. Further, each band 3 is formed by arranging a large number of information tracks 4, and each track 4 has an information capacity of about several tens to 100 bits. Further, each band is separated by a reference line (hereinafter referred to as R line) 5. Note that arrow A is the moving direction of the optical card 1 during reproduction, and arrow C is the information reading scanning direction by the optical head during reproduction.

FIG. 10 is a schematic diagram of an apparatus for reproducing an optical card having the above-described recording format.

In the figure, an optical card 1 can be reciprocated in six directions indicated by arrows by a rotation mechanism 6. Information recorded on the optical card 1 is read and reproduced track by track by an optical head 11. First, light from a light source 7 such as an LED is focused by a lens system 8 to illuminate the optical card 1. The optical card 1
The image of the track is formed on a one-dimensional sensor array 10 by an imaging optical system 9. As the optical card I moves in the six directions of the arrow, the image of the information track on the sensor array 10 changes accordingly. The sensor array 10 is read and scanned several times while each information track is imaged onto the sensor array 10. In this way,
Recorded information on several information tracks in a certain band is reproduced, and when this is completed, the optical head 11 is moved appropriately in the direction of arrow C to reproduce information tracks in other targeted hands onto the sensor array. The recorded information is reproduced in the same manner as described above.

FIG. 11 is a partially enlarged schematic diagram of the recording format of the optical card shown in FIG. 9. Note that the shaded area in the figure represents information "1", and the blank area represents information "0".

FIG. 11 shows one end of the recording area of the optical card 1 in the direction of arrow A. In the figure, 201 is an information track area, and in this area, one row of information bit arrays in the direction of arrow C constitutes one information track. 202
is the R line, and the R line and the information track area 20
1 forms a band 203. Note that 204 is a unit data area of the information track, which consists of 5 bits.

An information track is a collection of such unit data areas.

The R line 202 has a length of 6 bits in the direction of arrow C, 2 bits on both sides of each side (jj+l l bits) are information "0", and the width of the 4 bits in the center in the direction of arrow A is Stripe-like information “1” shorter than 1 bit
, and each stripe is arranged corresponding to each information track.

The reading operation of the information track by sensor array] O is as follows:
By detecting the information "011110" on the R line 202, it is determined that the alignment with the information track has been set correctly, and the process is started.

Next, the optical card 1 moves in the direction of arrow A with respect to the optical head 11, the information "011110" on the R line disappears, the information "oooooo" is obtained, and then the information "01110" is obtained again.
1110" appears, it is determined that the next information track has been entered, and the same reading as above is performed. In this way, the R line 202 is an area for separating and identifying adjacent tracks in the C direction. It is also an area for separating and identifying tracks adjacent in the A direction.

In order to reproduce information from an optical card having the above-mentioned recording format over multiple bands, an optical head 1
1 in the C direction, the information tracks of each band are sequentially reproduced. At this time, the target band 20
It is necessary to control the position of the optical head 11 so that the image of the information track is within the effective reading range of the sensor array 10 over the entire range of 3. This control of the optical head position is performed to position the R line 202 of the target band within a predetermined range of the sensor array 10.

[Purpose of the invention]

Incidentally, it is desirable that the speed of optical card playback as described above be as fast as possible. In order to improve the playback speed, it is necessary to increase the moving speed of the optical card 1 in the direction of arrow A.

However, in order to move the optical head 11 between bands, arrow C
It is very difficult to increase the speed when moving while controlling the direction. Therefore, if the moving speed of the optical card 1 is increased only in the direction indicated by the arrow, the optical head 11 is moved along the arrow C so that the image formation state on the sensor array 10 is detected and the target R line is imaged at an appropriate position. While the optical card 1 is being controlled in this direction, the optical card 1 moves in the direction of the arrow A, and some tracks (especially some tracks near the leading track) pass within the reading range of the sensor array 10. There is a possibility that playback may become impossible. If an information track fails to be read in this way, it is necessary to access the track again for reading, and as a result, it becomes impossible to achieve a reduction in playback time.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a reproduction method that allows access to a target information track accurately and commercially.

[Summary of the invention]

According to the present invention, the above-mentioned object is achieved by associating a reproducing head with an information recording carrier having a plurality of information tracks and having an area for introducing the reproducing head corresponding to each track or each track group. In a method of reproducing information by moving the information recording carrier in a specific direction, the relative movement between the information recording carrier and the reproducing head includes movement in a first direction for reproducing information and detecting a head introduction area of the information recording carrier by the reproducing head. movement in a second direction across the first direction for positioning the head, and during relative movement in the second direction, the relative movement speed in the first direction is higher than that in the second direction. This is achieved by a method for reproducing an information recording carrier, which is characterized in that the relative movement speed in the first direction is slower than the relative movement speed in the first direction when reproducing information without performing relative movement.

〔Example〕

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a partially enlarged schematic diagram of a recording format of an embodiment of an information recording carrier used in the method of the present invention,
It shows the same part as FIG. 11 above.

In FIG. 1, 201 is an information track area, and in this area, one column of information bit arrays in the direction of arrow C constitutes one information track. 204 is a unit data area of the information track, which consists of 5 bits. An information track is a collection of such unit data areas. 202 is a separation region or R line. In this embodiment, R line 2
02 corresponds to the information track area 201, similar to the one in FIG.
In addition to having a portion formed in a region adjacent to the direction of
It also has a portion 205 extending outwardly in the direction of . A band 203 is formed by this R line 202 and the information track area 201.

Each unit data area 204 of the information track is composed of 5 bits, and the stored data is 415-converted according to the conversion rules shown in the following table, and is further NRZI-modulated and recorded.

FIG. 2 is an explanatory diagram of the 415NRZI modulation method adopted in this example. As shown in the figure, hexadecimal data Eφ is converted into 415 and further NRZI modulated.
The signal recorded by the NRZI modulation method has T,2
Only signals with a length of T, 3T are included. Here, T is the minimum inversion interval of the signal, and the recording former shown in FIG.
Corresponds to 1 bit in the node. That is, the information recorded in the information track area 201 does not include an inversion interval of 4T or more.

Therefore, in this embodiment, an area having an inversion interval of 4T is used as a separation area for separating and identifying information tracks (i.e., a separation area for separating and identifying information tracks).
R line) 202. That is, R line 2
02 has a length of 6 bits in the direction of arrow C, similar to the one in FIG. Is it a striped pattern whose width in the arrow direction is shorter than 1 bit (for example, about 1/2)? Ii "1". Thus, the separated signal "0" with an inversion interval of 4T in the direction of arrow C.
An area of 11110'' is formed.Of course, the area is not limited to this, and it is sufficient to record it so that it can be distinguished when read.

Further, although the information track has 16 unit data areas 204 and consists of a total of 80 bits, no preamble area for obtaining a self-clock during reproduction is provided.

In this way, since the separated region 202 includes consecutive identical codes that do not appear in the information track, the R line can be detected reliably. Furthermore, since it does not include a preamble area for extracting an information reproduction clock and requires fewer bits other than data, more data can be stored.

Furthermore, in this embodiment, since the stripe width in the arrow A direction of the central 4 bits of information "1" in the arrow C direction in the R line 202 is shorter than 1 bit, the third stripe width is shorter than 1 bit.
As shown in the figure, information track and one-dimensional sensor array 1
Even if the parallelism of the corresponding areas read by 0 is off, if the separation signal "011110" of the R line 202 can be completely read on the one-dimensional sensor array 10, the entire one-dimensional sensor array 10 will be on the same information track. Compatibility is guaranteed.

In this embodiment, a portion 205 of the R line 202 that extends further outward in the direction of arrow A from the portion of the R line 202 corresponding to the information track area 201 is located at the position of the optical head 11 in the direction of arrow C. This is the area where the optical head is introduced for control.

Next, an embodiment of the method for reproducing information from the information recording carrier according to the present invention will be described. Here, an optical card is used as an information recording carrier having the recording format shown in FIG. 1, and a reproducing apparatus shown in FIG. 10 is used as a device for reading information from the optical card. Further, as shown in FIG. 4, the optical magnification is selected here so that one bit 206 in the recording area of the optical card is imaged onto four cells 207 of the one-dimensional sensor array 10. For example, the size of 1 bit 206 of an optical card is 10 μm1-
The size of the cell 207 of the dimensional sensor array 10 is set to 15 μm.
If so, the imaging optical system 9 should have a magnification of 4xl 5/10-6 (times).

FIG. 5 is an explanatory diagram showing a method for reproducing an information recording carrier according to the present invention.

In the figure, there is a band 203 in the recording area on the optical card.
and bands 203a and 20 adjacent to band 203.
3b and each band's information track 21° 21a, 21b
and a separation area 202 for separating each information track.
202a and 202b are formed in the format shown in FIG. Here, one band track is formed of a separation area (6 bits) and an information track (80 bits), totaling 86 bits. Therefore, 1
The band tracks are imaged onto 344 cells 207 on the sensor array 10 .

Therefore, here, a CO with 512 cells 207 is used.
D is used as the one-dimensional sensor array 10, and the reading area 208 is set so that part of the information tracks 21a and 21b adjacent to the information track 21 to be read is also imaged on the sensor array 10.

By providing the reading area 208 in this manner, the clock can be extracted during reproduction without providing a preamble area for obtaining a self-clock in the information track 21 to be read. That is, the reading area 208
When the sensor array 10 scans in the direction of the arrow B, a reproduction clock is extracted using, for example, information on a portion of the information track 21a. Then, from the time when the separation area 202 is detected, the information recorded on the information track 21 is reproduced using the extracted clock, and the information recorded on the information track 21 is reproduced, and
The information reproducing operation is stopped by detecting b.

Furthermore, the separation region 202 on the -dimensional sensor array
The relative position of the reading area 208 and the information track 21 can be known from the signal.

FIG. 6 is a block diagram showing an example of a device for reproducing information from an optical card according to the present invention.

In the figure, a sensor array 10 having a reading area 208 is driven by a driving clock 307 from a sensor array driver 306, and its output signal 308 is also amplified by the driver 306 and inputted as a video signal 309 to a binarization circuit 310. Ru. The video signal binarized by the binarization circuit 310 is sent as an NRZI signal 311 to a clock regeneration circuit 312, an NRZT demodulation circuit 314, and an RZI signal 311.
Each is input to the line detection circuit 316.

The clock regeneration circuit 312 extracts the clock signal 313 from the NRZI signal 311 and outputs the clock signal 313 from the NRZI signal demodulation circuit 31.
Output to 4. The NRZI demodulation circuit 314 inputs the clock signal 313 and the NRZI signal 311 and outputs the NRZ signal 315, which is a demodulated signal, to the 5/4 conversion circuit 320. On the other hand, the R line detection circuit 316 uses the frequency divider circuit 3
], the clock signal 318 obtained by frequency-dividing the driving clock 307 from 7 is further converted into the NRZI signal 3 from the binarization circuit 310.
11, respectively, and input the R line detection signal 319 to 5.
/4 conversion circuit 320. 5/4 conversion circuit 320
is the NRZ signal 31 according to the R line detection signal 319.
Convert 5 to 5/4.

The R line position detection circuit 321 counts the number of clocks of the drive clock 307 inputted from the time when the read start signal 322 of the sensor array driver 306 is inputted until the time the R line detection signal 319 is inputted, and detects the R line position detection circuit 321. A position signal 323 is output.

FIG. 7 is a block diagram of the R line detection circuit 316. In the figure, an NRZI signal 311 is input to a serial input terminal of a shift register 401, and a clock signal 318 whose frequency has been divided by four is input to a clock input terminal. Further, the 6-bit parallel output terminals of the shift register 401 are respectively connected to the input terminals of the minus number circuit 402 of "011110". The coincidence signal of the -number circuit 402 is outputted to the 5/4 conversion circuit 320 as the R line detection signal 319. Further, the 6-bit parallel output terminals of the shift register 401 are respectively connected to the input terminals of the minus number circuit 403 of "oooooo". - Match signal 3 from number circuit 403
24 is obtained.

The specific operation of the reproducing apparatus having such a configuration will be explained with reference to FIGS. 1 and 5.

When the sensor array 10 scans the reading area 208 in the direction of the arrow B using the driving clock 307, first, a read signal of part of the information of the information l rank 21a appears in the NRZI signal 311. As mentioned above, this signal is
In principle, the reversal interval is T.

Since it is only 2T and 3T, the clock signal 313 can be recovered by extracting the minimum inversion interval T by a clock recovery circuit 312 using a PLL circuit or the like. Using this clock signal 313, the NRZI signal 311 is demodulated into an NRZ signal 315 by a demodulation circuit 314. However, unless the first R line detection signal 319 is input, the
/4 conversion circuit 320 does not operate. That is, the shift register 401 of the R line detection circuit 316 is sequentially inputted with each bit signal in the reading area 208, and is always filled with signals for 6 bits. Therefore, the contents stored in the shift register 401 are 1 TiIt area 202 or 2
Unless it matches the recorded content "011110" of 02b,
R line detection signal 319 is not output.

6-bit information of the first separation area 202 “011110
'' is stored in the shift register 401, the - number circuit 4
02 outputs an R line detection signal 319, whereby the 5/4 conversion circuit 320 starts a conversion operation. Therefore, the NRZ signal 315 corresponding to the information on the information track 21 to be read is converted into 5/4 and output as a reproduced signal.

Then, the information of the next separation area 202b is “011110”
is stored in the shift register 401, the - number circuit 40
2 outputs the R line detection signal 319, and the 5/4 conversion circuit 320 stops outputting the reproduced signal.

In this way, information reproduction of the information track 21 to be read is executed by the self-clock. Similarly, a desired information track is selected as a reading target by moving the optical card in the direction of arrow A and/or moving the optical head 11 carrying the sensor array 10 in the direction of arrow C, and the information is reproduced.

By the way, since the movement of the sensor array 10 and the relative movement of the optical card with respect to the sensor array 10 are performed asynchronously, the scanning speed of the sensor array 1o in the direction of arrow B and the movement speed of the optical card in the direction of arrow A are different. Depending on how you choose,
A single information track may be scanned multiple times. For example, if the frequency F of the clock 307 that drives the sensor array 10 with 512 cells is 10 Mtlz, the moving speed of the optical card is 40 m++/see, and the size L of 1 bit of the optical card is 10 μm, - information track The number of scans per hit S is S=L/Vx 1/(1/Fx 512)=488. Therefore, it is necessary to detect that the optical card has moved to the next information track. This is done as follows. That is, the minus number circuit 403 outputs the coincidence signal 324 when it detects the recorded content "oooooo" in the separation area 202 or 202b. Therefore, by obtaining the R line detection signal 319 after detecting the coincidence signal 324 from the minus number circuit 403, it is possible to know that the track has moved to a new track.

Next, referring to FIG. 8, -dimensional sensor array 10
+fff[! ) A control method for properly imaging the rack will be described below.

First, assume that the area Sa of the optical card is imaged on the sensor array. The output of the sensor array at this time is only the leading signal 322, as shown on the right side of the figure. Next, when the optical card moves in the direction of arrow A and the area sb comes to be imaged on the sensor array, an R line detection signal 319 appears in the output of the sensor array as shown on the right side of the figure. Therefore, in the R line position detection circuit 321, by counting the number of driving clocks between the leading signal 322 and the R line detection signal 319, the relative imaging position of the information track with respect to the sensor array is determined by the R line position signal 321.
It can be known as. Therefore, based on the signal 323, the drive control of the optical head in the direction of arrow C is performed so that as the optical card moves in the direction of arrow A, the image formation area of the card on the sensor array further becomes 5c-3d. Let's do it. As a result, the optical head can be moved to a proper position before the information track area 201 is imaged on the sensor array, and as soon as the information track area 201 is imaged on the sensor array, as described with reference to FIG. Reading of various information will begin.

In reproducing the optical card as described above, by keeping the moving speed of the optical card in the direction of arrow A small when controlling the position of the optical head based on the R line position signal 323, the optical head can be introduced into the separation area 202 of the optical card. Arrow A in area 205
The length in the direction can be shortened. Since the card normally moves back and forth in six directions, the movement speed may be slow during this head positioning operation. (This is due to the characteristics of the drive motor's rise until the moving speed becomes constant.) If positioning is not possible within this slow speed, it is desirable to actively decelerate and perform positioning. In this way, the reduction in area of the information track area 201 due to the provision of the optical head introduction area 205, that is, the reduction in information recording capacity, can be minimized. This reduction in the speed of optical card movement during optical head position control can be achieved, for example, by utilizing deceleration near the reversal position and acceleration in the opposite direction when the optical card reciprocates in the direction of the arrow. That is, since an optical card normally moves back and forth in the direction of arrow A,
During this optical head position control operation, the moving speed of the card in the direction of the arrow may be slow (this is due to the start-up characteristics of the drive motor until the moving speed becomes constant).
, take advantage of this timing. If positioning is not possible within this slow speed, it is desirable to actively decelerate the speed to control the position of the optical head. Of course, when reading information from information 1-rank, arrow A on the optical card
The playback speed can be increased by increasing the moving speed in the direction.

In the above embodiment, the case where the modulation method is the 415NRZI modulation method is shown, but any self-clockable modulation method that requires an area for obtaining a clock for information reproduction, such as MFM or EFM modulation method, may be used. Applicable to In addition, the signal area (preamble) for extracting the reproduction clock within the band is not limited to the self-clock method.
Of course, it does not matter if the

Furthermore, it is clear that the adjacent area used for extracting the reproduced clock may be the entire adjacent information track or an area spanning a plurality of hands.

Furthermore, the present invention is applicable to record carriers such as magneto-optical record carriers in which the direction of magnetization is reversed, record carriers with concave and convex bits, and the like.

〔Effect of the invention〕

According to the present invention as described above, when positioning the optical head in the second direction, the relative movement speed in the first direction is relatively small, so the positioning can be performed accurately, and when reading information, the relative movement speed in the first direction is relatively small. Since the relative movement speed in the first direction is relatively high, recorded information can be reproduced quickly and accurately without causing reading errors, and the optical head introduction area provided on the information recording carrier can also be small. There is also less decrease in information storage capacity.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a recording formant of an information recording carrier. FIG. 2 is an explanatory diagram of the 415NRZI modulation method. FIG. 3 is an explanatory diagram showing the correspondence between information tracks and sensor arrays. FIG. 4 is an explanatory diagram showing the correspondence between the sensor array and the information recording bits of the information recording carrier. FIG. 5 is an explanatory diagram showing a method for reproducing an information recording carrier. FIG. 6 is a block diagram of an information recording carrier reproducing device,
FIG. 7 is a block diagram of the reference line detection circuit. FIG. 8 is a schematic diagram showing a change in the imaging area on the sensor array and a corresponding change in the output of the sensor array during reproduction of the information recording carrier. FIG. 9 is a schematic plan view showing the recording format of the optical card. FIG. 10 is a block diagram of an information recording carrier reproducing apparatus. FIG. 11 is a schematic diagram showing the recording format of the information recording carrier. 201: Information track area 202: Separation area 203: Band 204: Unit data area 205: Optical head introduction area

Claims (2)

[Claims] (1) Information is reproduced by relatively moving the information recording carrier, which has a plurality of information tracks and has an area for introducing the reproduction head corresponding to each track or each track group, and the reproduction head. In the method, the relative movement between the information recording carrier and the reproducing head includes the first direction movement for information reproduction and the above-mentioned method for detecting the head introduction area of the information recording carrier by the reproducing head and positioning the head. and a movement in a second direction across the first direction, and information in which the relative movement speed in the first direction during the relative movement in the second direction does not cause the relative movement in the second direction. A method for reproducing an information recording carrier, characterized in that the relative movement speed in the first direction during reproduction is slower than the relative movement speed in the first direction. (2) A patent claim in which the movement in the first direction is a linear reciprocating motion, and the movement in the second direction for head positioning is performed without reproducing information near the time when the reciprocating motion is reversed. A method for reproducing an information recording carrier according to the scope of item 1.