Data recording and reproducing apparatus for an optical card

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FIELD OF THE ART

This invention relates to a data recording and reproducing apparatus for an optical card, which is constituted to drive an optical card in a reciprocating manner in a direction parallel to tracks to conduct recording and reproducing of data.

BACKGROUND ART

As the present time is called a card age, cash cards, credit cards, and various other cards appear on the market. Most of them are magnetic recording cards and especially cards of the business card size, which are convenient in carrying, are very often used. However, since recording capacity is not so much assured in magnetic recording cards of such a size, it is the present state that they are only used to the extent of memorization of collation card, e.g., secret code, account number or registration number, etc. extremely restricted. In this respect, optical cards which optically record information have the merit that the information content recorded is far greater than that of conventional magnetic recording cards.

Such a system to record information onto an optical card to reproduce them therefrom is disclosed in, e.g., the Japanese Patent Application Laid-Open No. 137245/86 publication. In this system, the direction of a laser beam is controlled by two servo control mirrors, thus to carry out scanning of recording areas on the optical card. Further, a method is disclosed in the Japanese Patent Application Laid-Open No. 40325/84 publication to effect recording and reproducing while a vibrating laser beam in a direction vertical to the scanning direction of the optical card, and an actual mechanism for a scanning laser beam is disclosed in the Japanese Patent Application Laid-Open No. 214239/86 publication. In addition, a format for recording data onto an optical card with high efficiency is disclosed in the application No. JP86/00134 specification under the Patent Cooperation Treaty.

However, problems with the data recording and reproducing apparatus for an optical card conventionally known are as follows.

(1) For an optical disc, it is sufficient to carry out scanning by a laser beam by revolving the disc. In contrast, since it is necessary for an optical card to be scanned by a laser beam lengthwise and breadthwise, the mechanism of an optical system for scanning laser beam becomes complicated. In addition, the optical path of the laser beam becomes elongated, with the result that an optical aberration is likely to occur.

(2) The recording area on the surface of an optical card is likely to be subjected to adhesion of dust or scratched, with the result that reading errors may occur at the time of reproduction or playback.

(3) Since data is recorded in the order of .mu.m on the optical card, it is necessary to load the optical card at a correct position within the apparatus with the accuracy of .mu.m order. However, such an operation for loading the optical card is very troublesome in the conventional apparatus.

(4) In the optical card, a plurality of tracks are defined on the recording area to arrange pits along the tracks, thus to record information. For this reason, reproduction or playback is carried out while conducting a tracking control and a focusing control. However, since there is employed a system to conduct these controls while scanning the laser beam lengthwise and breadthwise in place of conducting them while revolving the disc as in the optical disc, the control system becomes extremely unstable.

(5) Since reading is conducted by scanning a laser beam lengthwise and breadthwise as described above, noise components are likely to be mixed into a read signal, so that reading in which noise components are eliminated is difficult.

(6) For a reading apparatus for an optical card, there is an apparatus of the type to conduct a reading of every bit trains using a line sensor. However, the apparatus of the type to scan using a laser beam to effect reading is not compatible with the apparatus using line sensor.

DISCLOSURE OF THE INVENTION

Objects of this invention are as follows.

(1) To provide a data recording and reproducing apparatus for an optical card, in which the mechanism of an optical system used in recording and reproduction or playback is relatively simple.

(2) To provide a data recording and reproducing apparatus for an optical card, which permits reproduction or playback free from error even if the surface of the optical card is subjected to adhesion of dust or scratched.

(3) To provide a data recording and reproducing apparatus for an optical card, which can easily load the optical card at a correct position within the apparatus.

(4) To provide a data recording and reproducing apparatus for an optical card, which permits stable tracking and focusing control operations.

(5) To provide a data recording and reproducing apparatus for an optical card, which can effectively eliminate noise components mixed in at the time of reproduction or playback.

(6) To provide a data recording and reproducing apparatus for an optical card, which is of the laser beam scanning type compatible with an apparatus of the type which conducts a reading using a line sensor.

The first feature of this invention resides in a data recording and reproducing apparatus for use in an optical card, on which a plurality of tracks are arranged in parallel, the apparatus comprising:

card supporting means for supporting the optical card,

card drive means for reciprocating the card supporting means in a first direction,

an optical head for selectively providing an access to respective tracks to irradiate light beam at a position above the optical card to conduct recording/reproducing of data, and

head drive means for reciprocating the optical head in a second direction perpendicular to the first direction.

The second feature of this invention resides in that, in the above-described apparatus, guide sections are provided on both the ends of tracks of the optical card wherein when the optical head scans on the guide sections, the card drive means conducts acceleration and deceleration of the card supporting means.

The third feature of this invention resides in that there are further provided in the above-described apparatus,

an error correcting code addition circuit for adding error correcting codes to a plurality of blocks obtained by dividing user data to be recorded, respectively, thereafter to reorganize the blocks to deliver the reorganized data to the optical head as data to be recorded, and

an error correction circuit for applying a processing having an opposite relationship to the above-described reorganization to data read by the optical head to thereby reproduce the blocks before reorganization, thus to carry out a necessary correcting processing on the basis of the error correcting codes in the respective blocks.

The fourth feature of this invention resides in that, in the above-described apparatus, drive motors are provided in the card drive means and the head drive means wherein these drive motors are enveloped with a vibration proof metal and a vibration proof rubber, respectively.

The fifth feature of this invention resides in that, in the above-described apparatus, two vibration proof metal layers are provided to provide a vibration proof rubber layer between these layers.

The sixth feature of this invention resides in that, in the above-described apparatus, the card supporting means comprises pressing means for pressing the upper surface of the optical card, and positioning means which can be in contact with the side surface and away therefrom.

The seventh feature of this invention resides in that, in the above-described apparatus, the positioning means comprises a plunger slidably moving with respect to the body of the card supporting means, biasing means for applying a force in a direction allowing the plunger to be away from the side surface of the optical card, a pressure plate for applying a force in a direction allowing the plunger to be in contact with the side surface of the optical card, and a solenoid for driving the pressure plate.

The eighth feature of this invention resides in that there are further provided in the above-described apparatus,

positioning means having a contact surface in contact with one side surface of the optical card on the card supporting means, thus to conduct a positioning of the optical card by the contact surface, and

roller means having a rotation shaft slightly inclined with respect to a perpendicular set up on a plane including the above-described contact surface, and for introducing the optical card inserted from the outside onto the supporting means,

the optical card inserted from the outside being introduced toward the contact surface due to the inclination of the rotation shaft.

The ninth feature of this invention resides in that there is further provided in the above-described apparatus,

a control unit for carrying out a feedback control for the optical head in order to conduct a tracking control for allowing a beam irradiated from the optical head to be along the tracks on the optical card, and a focusing control for allowing the beam to be focused on the tracks,

whereby after a drive speed of the optical card or the optical head by the card drive means or the head drive means has fallen below a predetermined value, a feedback signal is locked at a value immediately therebefore, thus allowing the control unit to be operative in accordance with an open loop control.

The tenth feature of this invention resides in that, in the above-described apparatus, there is provided electromagnetic drive means in the optical head to deflect the irradiated light beam in a second direction by the electromagnetic drive means, thus permitting scanning of the light beam.

The eleventh feature of this invention resides in that a binarization circuit used in a data recording and reproducing apparatus, which comprises:

an AC-DC conversion unit for carrying out a full-wave rectification of an input signal,

an integration circuit for integrating an output from the conversion unit,

a comparator circuit for making a comparison between an output level of the integration circuit and a reference level to produce an output when the output level of the integration circuit is larger than the reference level,

a zero-crossing comparator for outputting a signal of a rectangular waveform which represents a high level when the input signal is positive and low level when the input signal is negative, and

gate means for permitting an output of the zero-crossing comparator to pass therethrough only when the comparator circuit produces an output.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view showing the basic configuration of a conventional data recording and reproducing apparatus for an optical card,

FIG. 2 is a perspective view of a data recording and reproducing apparatus according to an embodiment of this invention,

FIG. 3 is a block diagram of a control unit for controlling the operation of the apparatus shown in FIG. 2,

FIGS. 4 and 5(a), (b) and (c) are flowcharts showing the processing by the control unit of FIG. 3,

FIG. 6 is a top view showing an example of an optical card used in the apparatus according to this invention,

FIGS. 7 and 8(a), (b) and (c) are views showing a format of the optical card used in the apparatus according to this invention,

FIGS. 9 and 10(a), (b) and (c) are views for explaining the principle for recording user data in the apparatus according to this invention,

FIG. 11 is a view showing a vibration proof structure of a drive motor in the apparatus according to this invention,

FIG. 12(a) is a top view of a mechanism for carrying out positioning of the optical card according to this invention, and FIG. 12(b) is a cross sectional view taken along the lines A thereof,

FIG. 13 is a perspective view showing the basic configuration of a data recording and reproducing apparatus for an optical card provided with an automatic loading mechanism for optical card,

FIG. 14(a) is a top view of the automatic loading mechanism for optical card according to this invention, and FIG. 14(b) is a cross sectional view taken along the lines A--A thereof,

FIG. 15(a) and (b) are a view showing the arrangement of tracks on the optical card used in this invention and the scanning direction thereof,

FIG. 16 is a block diagram of a typical tracking and focusing control system,

FIG. 17 is a graph showing the frequency characteristic of a control signal in the control system shown in FIG. 16,

FIG. 18 is a block diagram showing an embodiment of a tracking and focusing control system according to this invention,

FIG. 19(a) and (b) are a time chart for explaining the operation of a hold signal generator circuit in the control system shown in FIG. 18,

FIG. 20 is a diagram showing an actual construction of the hold signal generator circuit in the control system shown in FIG. 18,

FIG. 21 is a block diagram showing another embodiment of a tracking and focusing control system according to this invention,

FIG. 22 is a block diagram of a conventional typical binarization circuit,

FIG. 23(a) and (b) are a timing chart for explaining the operation of the circuit shown in FIG. 22,

FIG. 24 is a block diagram of a binarization circuit according to this invention,

FIG. 25(a), (b) and (c) are a timing chart for explaining the operation of the circuit shown in FIG. 24,

FIG. 26 is a view showing a format suitable for reading by a line sensor,

FIG. 27 is a partially enlarged view of FIG. 26,

FIG. 28 is a view showing the basic configuration of a data recording and reproducing apparatus for an optical card of the line sensor reading type,

FIG. 29 is a structural view of an optical head of a data recording and reproducing apparatus of the laser beam scanning type which can carry out recording and reproducing of an optical card to which a format for line sensor is applied, and

FIGS. 30 to 32 are views showing different mechanisms having a function equivalent to that of the optical head shown in FIG. 29.

BEST MODE FOR CARRYING OUT THE INVENTION

.sctn.1 Basic configuration of the apparatus

1.1 Basic configuration of a conventional apparatus

Prior to the description of the basic configuration of an apparatus of this invention, the basic configuration of a conventional apparatus will be explained in a sense of comparison.

A data recording and reproducing apparatus shown in FIG. 1 is of the type which allows a card 151 to record data thereon, i.e., which scans the recording area surface of the card 151 by using a laser beam 154 generated from a light source 153 to thereby record or read a desired data. In this example, means for carrying the card 151 into the beam track is a holder 152. Means for scanning the beam on the card 151, which has been carried into the beam track, is servo control mirrors 159 and 161. The servo control mirror 159 is affixed so that it is rotated with a rotation shaft 160 being as an axis in a direction indicated by an arrow P, and serves to find out the edges in a lateral direction of a laser recording material in the rough mode of operation, and thereafter to identify a data track existing with it being spaced from the edge by a predetermined distance in the fine mode of operation. On the other hand, the servo control mirror 161 is affixed so that it is rotated about a rotation shaft 162, and serves to effect fine control of a movement of the beam along the length of the card 151. Accordingly, by movement of holder 152 and scanning by servo control mirrors 159 and 161, recording/reproducing of data are conducted at a desired address.

For light source 153, a laser diode laser is used in this example. In addition, a light emitting diode or a lamp, etc. may be used. In the case of recording, the recording surface is fused or melted by irradiating a high intensity light beam thereto.

Laser beams divided by the half mirror 156 are monitored by an optical detector 158 through a lens 157. Thus, confirmation of the beam intensity is made. At the time of reproduction or playback, a reflected light from the optical card 151 is detected by a light detector 165 through a half mirror 163 and a lens 164. Thus, presence and absence of pits are converted to an electric signal.

Meanwhile, since two servo control mirrors are provided in the above data recording and reproducing apparatus for optical card as previously described as the background art, the optical system is prolonged and a drive mechanism to carry out scanning by the optical system is necessary. Accordingly, because of ensurance of a necessary distance of the optical system and attachment of the drive mechanism, the structure becomes complicated and is difficult to make compact. In addition, the distance of the optical system is prolonged and there occur aberration and/or various optical problems resulting from the fact that lenses and mirrors are arranged to optically conduct a scanning. It will be seen that such problems are solved in the apparatus of this invention described below.

1.2 Basic configuration of an apparatus according to an embodiment of this invention

Basic configuration of an apparatus according to an embodiment of this invention will be now described with reference to FIG. 2.

In FIG. 2, reference numeral 101 denotes a card holder, reference numeral 102 an optical card, reference numeral 103 an optical head, reference numeral 104 an objective lens, reference numeral 105 a wire holder, reference numeral 106 a wire belt, reference numeral 107 joints, reference numeral 108 a head drive motor, reference numeral 109 a stage drive motor, reference numeral 110 a timing belt, reference numeral 111 a timing pulley, reference numeral 112 guide shafts, reference numeral 113 ball screws, reference numeral 114 a position sensor, reference numeral 115 a sensor for control, and reference numeral 116 pulleys.

The card holder 101 for holding the optical card 102 is driven by the stage drive motor 109 to effect a reciprocating movement along the guide shafts 112. Means for transmitting a drive force is timing pulley 111, timing belt 110, pulleys 116, wire belt 106, and wire holder 105, and means for detecting the position of the card holder 101 in driving is position sensor 114. As described later, a plurality of tracks are provided on the optical card 102 along the length direction which is the movement direction. By laser beam emitted from the lens 104 of the optical head arranged above with respect to the tracks, recording and reproducing of data are conducted. The head drive motor 108 drives the optical head 103 through the ball screw 113 to carry out coarse tracking for the optical card 102 with a block being as a unit (a block consists of a plurality of tracks), and to move the objective lens 104 of the optical head 103 in the case of conducting fine tracking with a track being as a unit. While the card holder 101 moves in a reciprocating manner along the guide shafts 112, positioning of the optical head 103 is carried out by the head drive motor 108 with a block being as a unit in the recording area of the optical card 102. By moving and adjusting the objective lens 104 by the control mechanism, the final tracking is conducted. Thus, recording and reproducing of data are carried out.

As just described above, in this apparatus, the rough positioning control of laser beam is conducted by the movement of the card holder 101 and the optical head 103, and the fine control is conducted by the movement of the objective lens 104. Accordingly, the mechanism of the optical system used in recording and reproduction or playback becomes extremely simplified as compared to the conventional apparatus.

1.3 Operation control system of the apparatus

The configuration of a control unit for conducting the operation control of the above-described apparatus is shown in FIG. 3 in a block form.

In FIG. 3, position sensor 114 is used for detection of position for acceleration/deceleration control and reciprocating inversion control in reciprocating drive by the stage drive motor 109. Optical head 103 is composed of a semiconductor laser 129, a signal sensor 130 for reading recording data, a control sensor 128 for focusing and tracking, an optical system (not shown) for detecting an error in focusing and tracking, and a control mechanism 131 for controlling the position of the objective 104 in order to conduct focusing and tracking. The entirety of the optical head 103 is driven by the head drive motor 108 in a direction perpendicular to the tracks of the optical card. In the case of conducting a tracking within the range of a block unit on the optical card, adjustment is made by the control mechanism 131 (i.e., only fine adjustment). On the other hand, in the case of conducting a tracking over one block unit, rough adjustment is made by the head drive motor 108 and fine adjustment is then made by the control mechanism 131.

A host computer 121 serves to supervise and control the entirety of the data recording and reproducing apparatus for optical card to give a command relating to rough adjustment of a drive system of a stage mechanism unit 125 (mechanism portion for driving the card holder 101 in FIG. 2) and the optical head 103 to a microcomputer 122 for stage control, and to give a command relating to a focus tracking to a focus tracking servo 127. In the case of recording data onto the card, recording data is delivered to the error correcting code addition circuit 133. On the other hand, in the case of reproducing data from the card, reproduced data is taken in through the error correction circuit 136.

The stage control microcomputer 122 delivers to the motor control unit 123 a position control signal of the head, a start/stop signal or a speed control signal of the stage mechanism unit 125 in accordance with a command of the host computer 121. The motor control unit 123 responds to this command to control the stage drive motor 109 while sensing the position of the card by the position sensor 114 to allow the running speed of the optical card to be constant to lessen the vibration of the running system of the optical card, and to control the head drive motor 108 to adjust the position of the optical head to a desired one.

The error correcting code addition circuit 133 serves to add error correcting codes to data so as to arrange bit trains in a distributed manner, thus to generate recording data resistant to burst errors as well. Because the detailed operation will be described later, brief explanation is made here. Namely, the error correcting code addition circuit 133 divides data trains delivered from the host computer 121 by a predetermined number of bits to add error correcting codes to the respective divided bit trains, thus to generate data with a block being as a unit. Then, they are distributed in accordance with a certain rule to edit bit trains recorded on the card. FM modulation circuit 134 serves to apply FM modulation to the bit trains. Means for controlling the semiconductor laser 129 on the basis of an output from the FM modulation circuit 134 is a semiconductor laser control circuit 135.

A signal analysis circuit 137 serves to execute a processing to analyze data recorded on tracks and regenerate such bit trains that are equivalent to the data outputted from the error correcting code addition circuit 133. To the signal analysis circuit 137, the bit trains are delivered, which are obtained by reading the recorded data at the signal sensor 130. The data signal from the sensor 130 is amplified at the signal amplifier circuit 140, and then the amplified signal is passed through the filter circuit 139, thereafter is binarized at the binalization circuit 138. The error correction circuit 136 serves to detect errors in bit trains using error correcting codes to correct error bits. The bit train data from which error correcting codes are eliminated after undergoing such a correction processing is transmitted as reproduced data to the host computer 121.

1.4 Operation of the apparatus

The outline of recording, reproducing and tracking operations in the system configuration shown in FIG. 3 will be now described.

Initially, the flow of the entire processing will be described with reference to FIG. 4.

First is to wait until the optical card is inserted into the card holder (step S1). When the card is inserted, the card holder is driven (step S2). Whether the processing designated by user is read or write is examined (step S3). When read is designated, the processing for read process is carried out until data in the designated area are all reproduced (steps S4, S6), while when write is designated, the processing for write process is carried out until data of write instructions are all recorded (steps S5, S6), thus to stop the card holder to end the processing (step S7).

In the case of write process at the step S5, i.e., recording data onto the card, data train is inputted as shown in FIG. 5(a) (step S8) to send it by the host computer 121 to the error correcting code addition circuit 133, and to send a recording address (track address) to the stage control microcomputer 122 and to the focus tracking servo 127. Data train to be recorded onto the card is transmitted from the host computer 121 to the error correcting code addition circuit 133, at which the data train is divided every 174 bits to add error correcting codes of 82 bits to respective 174 bits using the difference set cyclic code method to generate blocks with 256 bits being as a unit (step S9). Then, such an interleaving work is conducted to further rearrange bit data of a block unit thus generated in a predetermined order which will be described later (step S10) to constitute different block trains comprised of bit data of respective blocks, thus to modulate them at the FM modulation circuit 134. The stage drive motor 109 and the head drive motor 108 are controlled by the motor control unit 123 in accordance with a track address (steps S11 to S13) and the optical head 103 is controlled by the focus tracking servo 127 to allow the semiconductor laser 129 to output recording data through the semiconductor laser control circuit 135 to thereby record data on the card (step S14).

In the case of read process at the step S4, i.e., reproducing data having been recorded once on the card, a read address (track address) is sent to the stage control microcomputer 122 and the focus tracking servo 127 by the host computer 121 as shown in FIG. 5(b) and the semiconductor laser 129 is controlled in a regenerative mode through the semiconductor laser control circuit 135 (steps S15 to S17). Thus, recorded data is read from the track of the designated address by using the signal sensor 130 of the optical head (step S18). This read signal is first amplified at the signal amplifier circuit 140 and is subjected to noise elimination at the filter circuit 139, and is then binarized to a signal of "1" and "0" at the binarization circuit 138. Then, deinterleaving work for recomposing the binarized bit train so that it is changed to a bit train corresponding to the original information is carried out at the signal analysis circuit 137 (step S19). Then an examination and a correction of errors are conducted at the error correction circuit 136 (step S20). Finally, the data train from which the error correcting code is eliminated is sent to the host computer 121 (step S21).

As described later, each track is provided with an ID section in which an address thereof is recorded. In the case where a track being read at present is not a track of the designated address, a distance up to the designated address is calculated from the present address having been read as shown in FIG. 5(c) (step S22) to adjust the position of the optical head so that it moves to the corresponding address section. In this case, when the distance is longer than a range adjustable by the control mechanism 131 (when judged YES at step S23), the head drive motor 108 is controlled through the stage control microcomputer 122 from the host computer 121 (step S24). On the contrary, when the distance is within the range adjustable by the control mechanism 131 (when judged NO at step S23), the lens is moved to make an adjustment (step S25).

As is apparent from the foregoing description, since this apparatus conducts a tracking by reciprocating the card holder which is holding the optical card, the card holder may be driven on the basis of a simple linear drive and the optical head may be subjected to tracking in a direction perpendicular to the reciprocating direction of the optical card. Namely, since tracking is carried out to conduct recording and reproduction or playback only by linear drives in both the directions without carrying out a two-dimensional optical scanning, it is possible to simplify the mechanism and to improve the control accuracy. In addition, by providing an access to tracks at respective strokes of the reciprocating movement of the optical card, useless operation can be eliminated in the recording and reproducing processing.

.sctn.2 Format of optical card

2.1 Information of prerecord

An example of a format of an optical card suitable for a data recording and reproducing apparatus according to this invention will be described. FIG. 6 is a top view of this optical card 200. Data are recorded on a recording region 210 in the optical card 200. In the recording region 210, a large number of elongated or narrow tracks 211 are formed in a lateral direction of the figure. Recording and reproducing of data are conducted by reciprocating this optical card 200 in a lateral direction of the figure to scan a laser beam along the tracks 211.

For this purpose, the recording region 210 is composed of an n number of tracks as shown in FIG. 7, wherein each track is composed of a guide section G, and an ID section I, a user area U, an end section E, and a guide section G in the order recited in a read direction, and a group of tracks to be read in a right direction and a group of tracks to be read in a left direction are mixed with each other. In this example, odd tracks are read from the left to the right and even tracks are read from the right to the left. Since read directions are different interchangeably, it is possible to read the first track up to the n-th track in sequence with good efficiency by the reciprocating movement of the optical card. In this example, guide sections G are formed as continuous grooves, e.g., having a length of 5 mm, and are used for securing stabilization of focusing or tracking when the optical card is accelerated or decelerated. Block addresses with a plurality of tracks being as a group and track addresses within blocks are prerecorded in ID sections I as information of tracks with they overlapping with each other. Information significant when reading a track concerned in an opposite direction is prerecorded in the end section E as termination information of tracks. Namely, in the case of reading a track in an opposite direction, the end section E comes immediately next to the guide section G. Thus, the system is informed at an early stage that the track is being read in an opposite direction. As described above, in this optical card 200, the direction from guide section G to ID section I is taken as a reading direction. Scanning of laser beam is accelerated or decelerated at the guide section G, and is maintained at a predetermined speed at ID section I, user area U, and end section E. It is to be noted that while reading directions are interchangeably set every tracks in order from the first track in the example shown in FIG. 7, such directions are not necessarily required to be set interchangeably. For example, in the case of an arrangement such that a plurality of heads are arranged to read a plurality of tracks at the same time, or in the case of an arrangement such that reading heads in a right direction and those in a left direction are arranged with they being spaced by a plurality of tracks, reading directions of a plurality of adjacent tracks may be the same, or reading directions may be the same simply in every block.

Further, in order to conduct tracking to effect recording and reproducing of a desired data while reciprocating the optical card, various information as described below are prerecorded into areas of the respective sections mentioned above. Namely, as shown in FIG. 8(a), ID section I is composed of Gap(FF.sub.H) for compensating operating time of hardware, Sync(OO.sub.H) successive thereto, AM1(FE.sub.H) including a missing clock and indicating that next data is address, Block and Track of 2 byte data indicating address, and CRCC for checking whether or not Block and Track are correctly read in. In addition, by prerecording a plurality of the same information with they overlapping with each other, a plurality of track retrievals are enabled during one reading operation. Moreover, as shown in FIG. 8(b), the user area is comprised of Gap(FF.sub.H), Sync(OO.sub.H), AM2(FB.sub.H) including missing clock and indicating that data recording section begins from the next, data recording section successive to Sync(OO.sub.H), and MG for absorbing recording error. This data recording section is a continuous area corresponding to 1024 bytes to form bits corresponding to the bit train using laser beam to record user data. As previously described, for allowing the end section E to have a meaning when reading in an opposite direction, this section is comprised of, from the side of the backward guide section, as shown in FIG. 8(c), Gap, Sync, AM3(FD.sub.H) including missing clock and indicating that the section concerned is end section, and Gap.

2.2 Recording of user data

As described above, user data are recorded into user area U of respective tracks. Since an error is likely to occur in the optical card, it is also required for improving reliability of the system to adopt a data recording method resistant to error. To realize this, as shown in FIG. 9, original data to be recorded is constituted with, e.g., 32 blocks and each block is comprised of information bits of 174 bits and error correcting code of 82 bits corresponding to the information bits. The first to the 32-th blocks are arranged as shown in FIG. 10(a), and bits of the first block are assumed as "1-1", "1-2", . . . , "1-256", bits of the second block as "2-1", "2-2", . . . , "2-256", bits of the i-th block as "i-1", "i-2", . . . , "i-256", respectively.

As shown in FIG. 10(b),

.circleincircle.1 Bit train starting from the 1st bit "1-1" of the 1st block and including the 2nd bit "2-2" of the 2nd block, . . . the i-th bit "i-i" of the i-th block, . . . the 32-th bit "32-32" of the 32-th block, the 33-th bit "1-33" of the 1st block, . . . the 256-th bit "32-256" of the 32-th block is assumed as the 1'st block.

.circleincircle.2 Similarly, bit train starting from the 1st bit "2-1" of the 2nd block, bit train starting from the 1st bit "i-1" of the i-th block, and bit train starting from the 1st bit "32-1" of the 32-th block are assumed as the 2'nd block the i'-th block, and the 32'-th block, respectively. As shown in FIG. 10(c), data train comprising the 1'st block, the 2'nd block, . . . the i'-th block, . . . the 32'-th block arranged in order recited is assumed as a unit data train recorded on an actual card.

By executing such an interleaving processing, even in the case where data is broken over several ten bits in the recording data train of FIG. 1(c), so that burst error occurs, since those errors are considered as only an error of several bits in respective blocks when viewed in terms of the original data trains of FIG. 9, it is possible to carry out correction processing such error by an error correcting code. Thus, information can be reproduced and used without hindrance.

It is to be noted that the format of this optical card is not limited to the above-described embodiment, but may be changed or modified in various manners. While such interleaving processing to distribute bits to be recorded at intervals of the number of blocks plus 1 bit is carried out in the above-described embodiment, they may be allocated to specific bit positions of respective blocks in which positions of respective bits are actually recorded. Namely, bits originally belonging to the 1st block are assumed as bit 1, bit 33, bit 65, . . . of respective blocks used for actual recording, it is sufficient to select bit 1, bit 33, bit 65, . . . of recording blocks by using hardware such as a multiplexer, thus permitting deinterleaving processing to be faster. In a manner as described above, a scheme may be used to execute interleaving processing at intervals of the number of blocks or other intervals to distribute bits to be recorded. In addition, it is of course that the number of bits constituting one block may be changed according to the system scale or size.

As just described above, the data recording and reproducing apparatus according to this invention has interleaving and deinterleaving functions to divide bit train data to be recorded into a predetermined number of bit units to add error correcting codes every bit units to constitute a plurality of data blocks, thus making it possible to reconstruct information of a block unit with a high precision, resulting in an improved reliability of the system.

.sctn.3 Vibration proof structure of the drive mechanism

3.1 Occurrence of vibration

In .sctn.1, the basic configuration of the apparatus according to this invention has been described with reference to FIG. 2. One feature of this apparatus resides in that card holder 101 and optical head 103 make reciprocating movements, respectively. However, the reciprocating movement has the problem that vibration is likely to occur as compared to the revolving movement. Particularly, vibration may considerably occur in the drive source of the reciprocating movement, thus giving a serious bad influence to the operation that the optical system within the optical head follows tracks on the optical card.

Namely, because head drive motor 108 and stage drive motor 109 reciprocate optical head 103 and card holder 101 in the apparatus shown in FIG. 2, respectively, they frequently repeat forward rotation and backward rotation, giving rise to peculiar vibration at the time of transition from forward rotation to backward rotation and vice versa. On the other hand, objective lens 104 of the optical head 103 moves while repeating a fine adjustment for positioning of tracks. Because such a movement frequency and the vibration frequency are nearly equal to each other, resonant phenomenon takes place, resulting in the problem that the optical head 103 comes off the heads.

3.2 Embodiment of vibration proof structure

For elimination of bad influences due to such vibrations, a vibration proof structure is implemented to the drive motor. An example of such a vibration proof structure is shown in FIG. 11.

A drive motor body 320 is enclosed with a vibration proof metallic plate 321 and is further enclosed with a vibration proof rubber 322. The drive motor body 320 thus enclosed is inserted into a vibration proof metallic case 323 and is fixed therewithin. Moreover, vibration proof metallic supporting legs 324 for height adjustment are fixed at the lower portion of the case 323. For these vibration proof metals, e.g., aluminum die casting (trade name: COSMARL) by Mitsubishi Kinzoku Kabushiki Kaisha may be used. Since vibrations of high frequency components are absorbed by plate 321, case 323 and supporting legs 324 which are made of vibration proof metal and vibrations of low frequency components are absorbed by vibration proof rubber 322, the problem of bad influence due to vibration is eliminated, thus making it possible to conduct a positioning of the optical head.

In addition to the vibration proof measure taken for the above-mentioned vibrating unit, various measures may be taken. For example, supporting table 117, optical head supporting pole 118, and guide shaft mounting members 119, etc. in FIG. 2 may be made of vibration proof metal. Also in the drive force transmission system comprising timing belt 110 and wire belt 106, a vibration absorbable arrangement is employed.

It is to be noted that this invention is not limited to the above-mentioned embodiment, but may be altered or changed in various manners.

While a sandwich structure such that vibration proof rubber is held between two vibration proof metals is employed in the embodiment of FIG. 11, the number of vibration proof metals and that of vibration proof rubbers are not limited to those in the above embodiment, respectively. For example, there may be employed an arrangement such that member subject to vibration proof is encompassed by a single vibration proof metal and a single vibration proof rubber.

When respective drive motors are enclosed with the vibration proof metal and the vibration proof rubber as described, vibrations of high frequency components are absorbed by the vibration metal and vibrations of low frequency components are absorbed by the vibration proof rubber, thus making it possible to reduce vibrations of the drive source and to precisely carry out positioning of the optical head.

.sctn.4 Positioning mechanism of the optical card

4.1 Basic configuration

The apparatus shown in FIG. 2 is an apparatus adapted to carry out recording and reproducing of the optical card 102 mounted on the card holder 101. For allowing this apparatus to be practical, it is required to precisely conduct a positioning of the optical card 102 on the card holder 101. An embodiment of a mechanism for such a positioning is shown in FIG. 12. FIG. 12(a) is a top view of card holder 101 of the apparatus shown in FIG. 2 and positioning mechanism 420 applied thereto, and FIG. 12(b) is a cross sectional view taken along the lines A--A thereof.

An opening 101a is formed on the side of the upper surface of the card holder 101 and an insertion groove 421 for inserting the optical card 102 in the card holder 101. The width in a lateral direction of the insertion groove 421 is formed so that it is larger than that of the optical card 102. The optical card 102 is inserted into the insertion groove 421 from an insertion pocket 422 provided in front of the card holder 101. A pair of leaf springs 423 are affixed toward the opening 101a on the upper surface of the card holder