Optical card and apparatus for writing and/or reading data thereon

Abstract: An optical card (1) for storing a large amount of data in an optically readable manner, includes a plurality of tracks (TR) formed in a data record layer (1b) in parallel with each other, each track (TR) being divided into a data record area (4) and an address record area (3), and identifiers (ID) each recorded in address record areas (3) of respective tracks. By optically reading the identifier from the optical card, it is possible to recognise automatically the track construction denoting the number of sectors per track and the number of bytes per sector, thereby enabling optical cards with different track constructions to be used automatically.

Description: This invention relates to an optical card and data reproducing/recording apparatus for use therewith. Optical cards are known from PCT Publication WO 82/020968, and Japanese Publication Kokai Nos. 61-51,287 and 61-150,391. A known type of optical card comprises a substrate in the form of a rectangular sheet made of synthetic resin, a data record layer applied on the substrate and a protection layer applied on the data record layer and made of transparent synthetic resin. The reading and/or writing of data for such an optical card is effected by projecting a laser beam onto the data record layer via the transparent protection layer. There have been proposed various kinds of optical cards having different constructions. In almost all optical cards, the data record layer includes a number of tracks extending in parallel with each other usually in the longitudinal direction of the card. Each track is composed of a data record area, and an address data area in which address data for identifying the relevant track is recorded. In general, the track construction of the optical cards are different from each other in accordance with applications thereof. For instance, the number of bytes in a sector is different for optical cards of different applications. In an application in which a large amount of data has to be read out and/or written in each operation, the number of bytes in a sector must be large such as 1024 or 2048 bytes. On the contrary, in an application in which a small amount of data is handled in each operation step, the number of bytes per sector is set to a small value, such as 32 or 16 bytes. In this manner, the numbers of bytes in a sector of optical cards for various applications differ from each other. The result of this is that the numbers of sectors in a track are also different for various kinds of optical cards. Optical cards having different track constructions cannot be handled by the same reading and/or writing apparatus. That is to say, each type of apparatus is designed and manufactured to be used exclusively for optical cards having predetermined track constructions. This causes a demerit upon makers for manufacturing writing and/or reading apparatuses. In order to use the same reading and/or writing apparatus for various kinds of optical cards, there have been proposed various methods. In one method, the writing and/or reading apparatus is readjusted by a user in accordance with particular track constructions of optical cards to be used. In another method, the writing and/or reading apparatus comprises a plurality of circuit sections each being constructed to deal with respective track constructions and a switching circuit for selecting one of said circuit sections in accordance with the track construction of optical cards to be used. The switching circuit may be manually operated by a user or is automatically operated with the aid of commands transmitted from a host computer. However, in these known methods, the user must recognize the track construction of respective optical cards which the users want to use. This requires the cumbersome and time consuming operation of the user. Moreover, in the known optical card system, it is impossible to utilize a writing and/or reading apparatus for plural kinds of optical cards having different track constructions. In other words, once the writing and/or reading apparatus has been adjusted to use a predetermined kind of optical card, the apparatus can no longer deal with optical cards having different track constructions. This would restrict the versatility of the optical cards. Further, in a known optical card, all the tracks in a card have the same track construction. Usually, each of the tracks in a card constitute a single sector which includes 1024 bytes. This is due to the fact that the track construction has to be determined in such a manner that the longest data can be recorded in one sector. Thus, it is apparent that the data record area of the optical card cannot be utilised efficiently in case of writing data having shorter length. According to one aspect of the present invention there is provided an optical card of the type comprising a sheet-form substrate on a surface of which there is provided a data record layer, on which data can be recorded in an optically-readable manner, said data record layer being protected by a protection layer formed thereover, in which card the data record layer comprises a plurality of mutually-parallel tracks divided so as to define an address record area, in which address information relating to respective tracks has been pre-recorded, and a data record area for storing data therein, there being pre-recorded in said address record area, in association with respective tracks and in a format automatically-readable by all apparatus with which the card is intended to be used, a plurality of identifiers (ID/8), indicating for each track (TR) the number of sectors and the number of bytes per sector, whereby, when the card (1) is in use, said apparatus can identify, and so operate in accordance with, the sector construction of the track concerned. According to another aspect of the present invention there is provided data reproducing apparatus for use with an optical card according to said one aspect of the present invention, which apparatus includes reading means for reading, during a read operation, data stored at a selected address in the data record area of such a card under the control of control means of the apparatus, the reading means being operable at the start of a read operation to scan the address record area of the card in order to locate the selected address, to read the identifiers corresponding to the track concerned, and to supply to said control means a read signal which is, at least in part, indicative of said identifiers, said control means being operable upon receipt of that read signal to identify the sector construction of that track and to cause the apparatus to operate during said read operation in accordance therewith. According to a further aspect of the present invention there is provided data recording apparatus for use with an optical card according to said one aspect of the present invention, which apparatus includes recording means, for writing data during a write operation into the data record area of such a card at a selected address therein under the control of control means of the apparatus, and reading means operable at the start of a write operation to scan the address record area of the card in order to locate the selected address, to read the identifiers corresponding to the track concerned, and to supply to said control means a read signal which is, at least in part, indicative of said identifiers, which control means are operable upon receipt of that read signal to identify the sector construction of that track and to cause the apparatus to operate during said write operation in accordance therewith. Since the track construction of an optical card embodying the present invention can be readily and automatically identified, the operations of reading from and writing onto the card are facilitated. Moreover, the need for all tracks on the card to be identical in construction can be avoided. FR-A-2312087 discloses an optical disk having a spiral-form track, the outermost turn of the track being formed in alternate sectors of the disk with guide segments, but having no data written therein. The purpose of these guide segments is to guide the optical head when reading from and writing onto the disk, but, by chance, those guide segments can also serve to identify the construction of the spiral-form track, i.e. to identify how many sectors are formed therein. This document is not, however, concerned with identification of track construction. Reference will now be made, by way of example, to the accompanying drawings, wherein: Figs. 1A and 1B show plan and cross-sectional views, respectively, of an optical card embodying the present invention; Fig. 2 shows a schematic view of the construction of a portion of the optical card shown in Fig. 1; Fig. 3 is a block diagram illustrating apparatus embodying the present invention; and Figs. 4, 5 and 6 show schematic plan views of various optical cards embodying the present invention. As shown in Figs. 1A and 1B, an optical card 1 embodying the present invention is of write-once type and comprises a substrate 1a in the form of a rectangular sheet, a data record layer 1b applied on one surface of the substrate, and a protection layer 1c applied on the data record layer. The substrate 1a is usually formed by synthetic resin such as acrylic resin. The data record layer 1b is generally composed of a plurality of thin films made of metals or metal oxides. The protection layer 1c is to protect the record layer 1b and is usually made of transparent synthetic resin, because the writing and reading are carried out by projecting a laser light beam onto the record layer 1b through the protection layer 1c. As clearly shown in Fig. 1A, the optical card 1 comprises an optical record section 2 in which a number of tracks TR have been formed in parallel with each other in the longitudinal direction of the rectangular optical card. Each track TR comprises an address record area 3 in which address data of the relevant track has been recorded, and a data record area 4 in which the data has been or will be recorded. In the present embodiment, in the address record area 3 of each tracks TR there has been recorded an identifier for denoting the construction of the relevant track in such a manner that the identifier can be automatically read out by means of an optical writing and reading head. Fig. 2 is a schematic view showing the data format of the address record area 3 of the track TR. The address record area 3 has a pull-in section 5 for recording a synchronizing pattern (SYNC) for pulling the clock pulse generation into synchronism with the optical scanning, a data mark section 6 for recording a data mark (DM) indicating a top of the data, a track number section 7 for recording a track number (TRACK NO.) and a special section 8 for recording an identifier (ID). The identifier ID has been recorded on the optical card together with the SYNC, DM and TRACK NO. In the present embodiment, the same identifier ID has been recorded in all the tracks TR, because all the tracks have the same track construction. The identifier ID may take various forms. For instance, the identifier ID may be formed as a pit pattern composed of a plurality of bits such as 8 bits and 16 bits. Usually the identifier ID may be formed by one or a few bytes for denoting track construction such as the number of sectors in a track and the number of bytes in a sector. For instance, when the identifier ID is composed of one byte, 256 different codes may be classified. Prior to the writing or reading, the identifier ID is read out so that the track construction of the optical card can be recognised automatically. Writing and reading apparatus embodying the present invention will now be described with reference to Fig. 3. In order to write the data in a data record area 4 of a track on the optical card, as shown in Fig. 1, the data read out of a sector buffer memory 11 is modulated in a modulating circuit 12 and a modulated data signal is supplied to a laser driving circuit 13. Then the laser driving circuit 13 produces a laser driving signal which is supplied to a semiconductor laser provided in an optical unit 14. The construction of the optical unit 14 in the optical card writing and reading apparatus is well known in the art, so that the detailed explanation thereof may be dispensed with. The driving current for the semiconductor laser in the optical unit 14 is modulated such that the laser beam emitted by the semiconductor laser in the optical unit exceeds the sensitizable level of the record layer 1b of the optical card 1. In case of reading the data written in the data record area 4 of the optical card 1, the output signal supplied from the optical unit 14 is amplified by a preamplifier 15 and then is converted into a bivalent signal by a signal processing circuit 16. The bivalent signal is then supplied to a demodulating circuit 17 to recover the data signal which is then stored in the sector buffer memory 11. Before effecting the writing and reading, the data recorded in the address record area 3 is read out. The reading operation for the address record area 3 is identical with that for the data record area 4, but in the reproduction for the address record area, the demodulated data from the demodulating circuit 17 is supplied to an address data recognizing circuit 18 via a selector 19 to recognize the track number TRACK NO. and the identifier ID. In this manner, it is possible to recognize automatically the track construction from the thus read out identifier ID. During the writing and reading, the apparatus is automatically controlled in accordance with the track construction. Therefore, it is not necessary to readjust manually the apparatus or to control the apparatus by a command from a host computer. As shown in Fig. 3, the address data and the identifier data denoting the track construction or track format generated by the address data recognizing circuit 18 are supplied to a control circuit 61. In the control circuit 61, the read-out address is compared with an address of a track for which the writing or reading is to be effected. When these addresses do coincide with each other, the control circuit 61 supplies a head driving control signal to a head driving control circuit 62 which then supplies a driving signal to a head driving unit 63 for moving the head. At the same time, the control circuit 61 supplies a card driving control signal to a card driving control circuit 64 which supplies a driving signal to a card driving unit 65. The head driving unit 63 includes a sensor for detecting the movement of the head to generate a detection signal. The detection signal is supplied to the head driving control circuit 62 to effect speed control and position control of the head. The card driving unit 65 also includes a sensor for detecting the movement of the card to generate a detection signal which is supplied to the card driving control circuit 64 to effect speed control of the card. The head driving control circuit 62 and card driving control circuit 64 supply various kinds of status signals to the control circuit 61. The status signals may include limit position signal, home position signal and end of movement signal. When the read-out track address is identical with the desired track address, the movement of the head and card is stopped. When data is read out of the optical card 1, the control circuit 61 supplies a data take-in control signal to the sector buffer memory 11 at predetermined timings in accordance with the track construction. It should be noted that the selector 19 is also controlled by the control circuit 61. In the writing mode, the control circuit 61 supplies a data output control signal to the sector buffer memory 1, modulating circuit 12 and laser driving circuit 13 to control these circuits at timings predetermined in accordance with the detected track construction. As shown in Fig. 4, another optical card 21 embodying the present invention comprises two data record sections 22 and 23 having different track constructions. In the first data record section 22, each of its tracks comprises four sectors divided by three sector marks 24, and in the second data record section 23 each of the tracks includes three sectors divided by two sector marks 24. The tracks in the first data record section 22 further comprise address record areas 25 in which track numbers and identifiers for respective tracks have been previously recorded. In address record areas 26 of the tracks belonging to the second data record section 23 there have been also recorded the track numbers and identifiers. By reading the identifiers stored in the address record areas 25 and 26 of respective tracks, it is possible to recognize the track constructions, so that the writing and reading of the data for the data record sections 22 and 23 can be automatically adapted to the track construction. According to an embodiment of the present invention, a single optical card can comprise tracks having different track constructions and therefore the data can be recorded effectively on the optical card without wasting the data record areas. As shown in Fig. 5, yet another optical card 31 embodying the present invention comprises first and second data record sections 22 and 23 as in the embodiment shown in Fig. 4. Each track in the first and second data record sections 22 and 23 includes two address record areas 25a, 25b and 26a, 26b, respectively provided at respective ends of the tracks. In case of effecting the writing and reading in the left to right direction, the track construction can be recognized by reading the identifiers recorded in the left hand side address record areas 25a and 26a, and in case of performing the writing and reading in the right to left direction, the track constructions can be read out of the right hand side address record areas 25b and 26b. Still another optical card embodying the present invention is shown in Fig. 6, in which card a plurality of first data record sections 22 having tracks each including four sectors divided by three sector marks 24, and a plurality of second data record sections 23, having tracks each of which comprises three sectors, are provided in a mixed manner. The present invention is not limited to the embodiments explained above, but many modifications and alternations may be considered by those skilled in the art within the scope of the invention. In the above embodiments, the optical cards are of the write-once type, but an embodiment of the present invention may be equally applied to ROM cards in which only the reproduction can be affected. Moreover, in the embodiments shown in Figs. 4 to 6, there are provided two kinds of track constructions, but more than two track constructions may be provided.

Claims: An optical card (1) of the type comprising a sheet-form substrate (1a) on a surface of which there is provided a data record layer (1b/2), on which data can be recorded in an optically-readable manner, said data record layer (1b/2) being protected by a protection layer (1c) formed thereover, in which card (1) the data record layer (1b/2) comprises a plurality of mutually-parallel tracks (TR) divided so as to define an address record area (3), in which address information relating to respective tracks (TR) has been pre-recorded, and a data record area (4) for storing data therein, there being pre-recorded in said address record area (3), in association with respective tracks and in a format automatically-readable by all apparatus with which the card (1) is intended to be used, a plurality of identifiers (ID/8), indicating for each track (TR) the number of sectors and the number of bytes per sector, whereby, when the card (1) is in use, said apparatus can identify, and so operate in accordance with, the sector construction of the track concerned. An optical card as claimed in claim 1, wherein each identifier (ID/8) comprises a plurality of optically-readable pits. An optical card as claimed in claim 1 or 2, wherein said tracks (TR) comprise at least two mutually-distinct groups (22, 23) of tracks having different respective sector constructions. An optical card as claimed in any preceding claim, wherein the said address record area (3) comprises two address record regions (25a, 25b; 26a, 26b) between which is located said data record area (4), each address record region (25a, 25b; 26a, 26b) having pre-recorded therein in association with each track (TR) the identifiers (ID/8) therefor. Data reproducing apparatus for use with an optical card (1) according to any preceding claim, which apparatus includes reading means (13 to 17) for reading, during a read operation, data stored at a selected address in the data record area (4) of such a card (1) under the control of control means (11, 18, 61) of the apparatus, the reading means (13 to 17) being operable at the start of a read operation to scan the address record area (3) of the card (1) in order to locate the selected address, to read the identifiers (ID/8) corresponding to the track (TR) concerned, and to supply to said control means (11, 18, 61) a read signal which is, at least in part, indicative of said identifiers (ID/8), said control means (11, 18, 61) being operable upon receipt of that read signal to identify the sector construction of that track (TR) and to cause the apparatus to operate during said read operation in accordance therewith. Data recording apparatus for use with an optical card (1) according to any one of claims 1 to 4, which apparatus includes recording means (12, 13, 14), for writing data during a write operation into the data record area (4) of such a card (1) at a selected address therein under the control of control means (11, 18, 61) of the apparatus, and reading means (13 to 17) operable at the start of a write operation to scan the address record area (3) of the card (1) in order to locate the selected address, to read the identifiers (ID/8) corresponding to the track (TR) concerned, and to supply to said control means (11, 18, 61) a read signal which is, at least in part, indicative of said identifiers (ID/8), which control means (11, 18, 61) are operable upon receipt of that read signal to identify the sector construction of that track (TR) and to cause the apparatus to operate during said write operation in accordance therewith. Apparatus as claimed in claim 6, wherein said reading means (13 to 17) are operable, during a read operation, to read data stored at a predetermined address in the data record area (4) of the card (1) under the control of said control means (11, 18, 61), and, at the start of a read operation, to scan the address record area (3) of the card (1) in order to locate the predetermined address, to read the identifiers (ID/8) corresponding to the track (TR) concerned, and to supply to said control means (11, 18, 61) a read signal which is, at least in part, indicative of said identifiers (ID/8), said control means (11, 18, 61) being operable upon receipt of that read signal to identify the sector construction of that track (TR) and to cause the apparatus to operate during said read operation in accordance therewith. Apparatus as claimed in claim 5, 6, or 7, wherein said control means (11, 18, 61) comprise recognition circuitry (18) for identifying said identifiers (ID/8) from said read signal. Apparatus as claimed in any one of claims 5 to 8, further comprising optical head driving circuitry (62, 63), connected and arranged for driving an optical head of the apparatus under the control of said control means (11, 18, 61), and optical card driving circuitry (64, 65), connected and arranged for driving said optical card (1) under the control of said control means (11, 18, 61), said control means (11, 18, 61) being operable to control said optical head driving circuitry (62, 63) and optical card driving circuitry (64, 65) in accordance with the identified construction of the track (TR) concerned.

Inventors: TANAKA HISAKATSU, TANAKA, HISAKATSU
Applicants: OLYMPUS OPTICAL CO, OLYMPUS OPTICAL CO., LTD.
Application year: 1988
Main classification: G06K19
IPC codes: G11B27, G11B7, G11B20