JPH051529B2 - - Google Patents

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an optical memory in which an optical recording area is provided on a card-type substrate, and data is written in the area in an optically readable light-dark pattern. Regarding cards.

[Prior Art] Conventionally, floppy disks, magnetic tapes, optical disks, and the like have been common as data recording media, but recently, optical memory cards have been attracting attention. This optical memory card has parallel stripes on a rectangular optical recording medium provided on a card-type substrate.
Set the area to record data.

Generally, when writing and reading data to and from a recording medium, it is necessary to synchronize the writing and reading times.

Conventionally, in the case of floppy disks, magnetic tapes, optical disks, etc., the shape and properties of each medium,
By taking advantage of the characteristics of the drive method, etc., it was possible to synchronize data writing and reading.

[Problems to be Solved by the Invention] Incidentally, even in optical memory cards, it is necessary to synchronize when writing and reading. However, optical memory cards themselves are still under development, and appropriate synchronization setting means have not yet been developed.

To this end, it is conceivable to apply the synchronization method in the conventional recording medium described above. but,
There is a problem that the structure of the writing/reading device becomes complicated and the characteristics of the optical memory card cannot be fully utilized.

That is, in the above-described synchronization method for the conventional recording medium, when serial data is recorded, a clock bit is recorded together with the data for synchronizing with the data during reading. Therefore, the writing/reading device requires a circuit for adding clock bits to the write data and a circuit for separating the clock bits from the read data, which has the disadvantage of complicating the device.

The present invention has been made in order to solve the above-mentioned problems, and by providing a clock bit separately from data writing, it is possible to eliminate the need for a circuit to add the clock bit to write data and a circuit to separate it from read data. - The purpose is to provide an optical memory card that can simplify the reading device.

[Means for Solving the Problems] As a means for solving the above-mentioned problems, the present invention firstly provides a data recording area of an optical memory card.
Clock bits are arranged in a matrix in an optically readable pattern.Secondly, the spaces between the rows or columns constituted by these clock bits are used as data storage tracks.Thirdly, the data storage tracks are: A track mark setting section is provided at both ends, and the area between the track marks is divided into a plurality of sectors by sector marks, and the address information of the sector is indicated at both ends of the data field in each sector. The sector identification section with identification information such as track number and sector number can be written symmetrically on the left side so that it can be read from the left side, and on the right side so that it can be read from the right side. It is characterized by what has been done.

[Operation] In the present invention, by arranging clock bits in a matrix, a track for data recording is set in the space between each clock bit in the row direction or column direction.

Also, when recording serial data, you already have
Since clock bits are provided, there is no need to mix clock bits with data, and the writing/reading device does not require a circuit to add clock bits to write data or a circuit to separate them from read data. can be simplified.

Furthermore, in the present invention, since data bits are recorded between a pair of clock bits, data tracking can be replaced by tracking of a clock track consisting of regularly arranged clock bits. Therefore, tracking can be performed easily and accurately.

In addition, the present invention operates as described above, as well as
It works as follows.

First, in the data track format, a sector identification section with identification information is placed at both ends of the data field in each sector, so that the left side can be read from the left side, and the right side can be read from the right side. Since the same information is written symmetrically, it can be written and read from either the left or right side of the track. Therefore, by relatively reciprocating the card and the write/read head in the track direction, the time required to access the data recording area is shortened.

Also, since there is no clock bit in the set data track, the sector length of each data track depends on the length of the data to be recorded.
Can be determined arbitrarily.

[Example] An example of the present invention will be described with reference to the drawings.

Structure of First Embodiment The first embodiment of the optical memory card of the present invention has a first embodiment.
As shown in the figure, an optical recording medium 2 is attached on a card-type substrate 1, and a large number of clock bits 3 are mounted on the optical recording medium 2, as shown in FIG. A data track 4 constituting a data recording area is set in the space between the rows or columns of the matrix constituted by the clock bits 3.

The optical recording medium 2 may be any medium as long as it can record digital information by changing the reflectance. For example, when irradiated with a laser beam or the like, the optical properties such as the reflectance of that part change and the state changes. It consists of layers of substances etc. to be preserved. Such changes in optical properties are brought about, for example, by local melting due to laser beam irradiation, which changes the reflection angle of the light beam, and by changes in reflectance due to photochemical reactions. .

The clock bits 3 are arranged in a matrix at regular intervals on the optical recording medium. Therefore,
3 clock tracks each in the row and column directions.
a and 3b are configured. The size of this clock bit 3 is set to an appropriate size that allows writing and reading, but it is desirable that it be as small as possible in order to increase the recording area. Generally, the size is the same as or smaller than the size required to record one bit of data. In this embodiment, the holes 5a are made smaller than the holes 5a for data bits.

The clock bits 3 can be formed, for example, by means such as the above-mentioned laser beam irradiation. The clock bits 3 may be formed by writing them one by one, but they may also be formed all at once by printing or other means when forming the optical recording medium 2. In practice, this method may be appropriate from the point of view of cost reduction.

In this embodiment, the data tracks 4 are set in spaces in the row direction of the matrix of clock bits 3, that is, between the clock tracks 3a. Data is recorded line by line within the data track 4 between a pair of clock bits 3, 3 arranged in the column direction.

Effects of the First Embodiment In the optical memory card of the above-mentioned embodiment constructed as described above, data is written by the reading head 6, as shown in FIG. When writing, a clock bit detection sensor (not shown) consisting of a photodiode or the like provided in the head 6 detects the clock bit, and the head 6 and the card board 1 are connected in accordance with the clock track formed by the bit. is relatively moved in the row direction of the clock bit matrix (in the direction indicated by X in FIG. 3).

Note that clock bits may be detected on either the upper or lower side of the data track 4, or may be detected on both the upper and lower sides. In the latter case, using the difference or ratio of the detection outputs of the upper and lower detection sensors,
Relative movement locus of write head 6 and data track 4
It is possible to judge whether or not the two are correctly parallel, that is, to perform a tracking error check.

Data can be recorded in various ways. In this embodiment, two consecutively arranged clock bits on the row direction clock track 3a are regarded as one unit.
An example of recording using the FM encoding method, which records 1-bit data, is shown below. That is, as shown in FIG. 2, a hole 5a is provided only at a position corresponding to one of a set of two clock bits to represent "1".
Further, "0" is represented by whether an integrated oval hole 5b is provided at a position corresponding to both of a set of two clock bits or whether no hole 5b is provided at all.

Data is written in accordance with the position of clock bit 3. That is, data is written using the clock bit as a synchronization signal. Therefore, no synchronization signal is required in the data to be written.

hole 5a for recording data in digital representation;
The formation of 5b is performed, for example, by irradiating the optical recording medium with a laser beam and locally melting the irradiated portion of the optical recording medium.

When data is written to one row of data tracks 4 in this way, the write head 6 returns to the end of the data track 4 on the writing start side and moves in the direction of the adjacent data track 4 (the third relative movement in the direction indicated by Y in the figure). Then, the above-described operation is repeated to write data to the data track 4.

Data is read from the optical memory card on which data has been written, using a read head (not shown).
Data tracking is performed in exactly the same way as in the case of writing described above. Then, the data detector 4 is irradiated, the reflected light is received by a reading sensor such as a photodiode, and data is read out according to the level of the reflected light. In this case, the corresponding clock bit is used as a synchronization signal.

Note that a CCD linear sensor equipped with a light receiving element corresponding to a series of clock bits can be used as the reading sensor. According to this, a certain range of data is serially read and output as a video signal.

As described above, according to this embodiment, a clock bit is provided separately from data writing, and a circuit for adding the clock bit to write data and a circuit for separating it from read data are not required, thereby simplifying the writing/reading device. can be converted into

Structure of Second Embodiment The second embodiment of the present invention is characterized by its data recording format, and the structure of the card is exactly the same as that of the first embodiment. Therefore, here:
Only the data recording format will be explained.

An example of the data recording format of this embodiment is shown in FIG.

The data recording format shown in the figure is provided corresponding to the data storage track described above, but its length can be set arbitrarily since it does not have an internal clock bit.

In this data recording format, track mark setting sections TM are provided at both ends thereof, and the area sandwiched between the track mark setting sections TM is divided into a plurality of sectors ST by sector marks SM.
At both ends of data field DF in each sector ST,
Left and right sector identification parts LSID and RSID are provided which have identification information such as a track number and sector number indicating address information of the sector ST.

Each of the sector identification parts LSID and RSID is provided with areas for setting a track number, a sector number, and an error detection correction bit. These are written in the left sector identification part LSID so that it can be read from the left side.
Further, the right sector identification section RSID is set so that the same information can be written symmetrically so that it can be read from the right side.

The data field DF has a data information area in which information regarding stored data is written, a data recording section in which data is written, and an error detection and correction bit.

The error detection and correction bits provided in each sector identification part LSID, RSID and data field DF provide a means to detect whether or not there is an error in the data when these contents are read, and if possible, It provides information that allows data to be corrected.

Effects of the second embodiment The second embodiment configured as described above can basically write and read data in the same manner as the first embodiment. The difference is that in the first embodiment, data can be written and read only from either the left or right side of the data track, but in the second embodiment, data can be written or read from either the left or right side of the data track. It's all about what you can do.

That is, if the write head starts writing data from the left side of a certain data track, then
First, write the track mark TM and first sector mark SM, then write the left sector identification section.
Write the track number, sector number, and error detection code such as a parity code to LSID#1. Next, data information, data, and error detection correction bits are written to data field DF#1 in this order. After that, right sector identification part RSID#1
Then, write exactly the same information as the information written to the left sector identification section LSID #1 in the order of error detection number, sector number, and track number so that the information and bit configuration are symmetrical. .

Thereafter, in the same manner, data is sequentially written to each sector #2 to #n of the data track. and,
After writing data to the last sector #n, the head moves to the next data track without returning to the data writing start position of the data track.

In the next data track, completely opposite to the above data track, the track mark TM and the first sector mark SM are written from the right side, and then,
The track number, sector number, and error detection code such as a parity code are written in the right sector identification section RSID#n. Then data field DF
Data information, data, and error detection correction bits are written to #n in this order. After that, the above right sector identification section RSID#n is added to the left sector identification section LSID#n.
Exactly the same information as that written in is written in the order of error detection number, sector number, and track number so that the information and the bit structure are symmetrical.

Thereafter, data is sequentially written in each sector #(n-1) to #1 of the data track in the same manner.

To read the data written on the optical memory card,
As in the case of writing above, it is possible to read from either the left or right side of the data track. That is, when the read head is located on the left side of the data track, the left sector identification part LSID of each sector is read to access the data field DF.
On the other hand, if the read head is located on the right side of the data track, the right sector identification section of each sector
Read the RSID and access the relevant data field DF.

As a result, according to the optical memory card of this embodiment, data can be written and read from either the left or right side of the data track, and unlike the unidirectional data recording format of conventional recording media such as disks and tapes, the The time can be significantly reduced.

Modifications of Embodiments In the above embodiments, data is written by forming holes, but the means for recording data in digital representation is not limited to holes. Any material may be used as long as it changes optical properties such as reflectance. For example, it may be formed of a small circular bit pattern filled with black. In this case, data can be written all at once by means such as printing.

Further, in the above embodiment, one row of data tracks is provided between a set of clock bits in the column direction, but two rows of data tracks may be provided.

Further, in the above embodiments, the clock bits and data bits are formed to cause a change in reflectance, but other optical properties may be used. For example, a configuration may be adopted in which reflected light is polarized, or a configuration in which transmittance of transmitted light is changed.

[Effects of the Invention] As explained above, the present invention provides clock bits separately from data writing, provides data tracks between the clock bits, and connects each data track to a plurality of sectors sandwiched between track marks or sector marks. By providing a sector identification section that writes the same information symmetrically at both ends of the data field in each sector, writing can be done without the need for a circuit to add clock bits to data or a circuit to separate clock bits from data. - The reading device can be simplified, and further, writing and reading can be done from either the left or right side of the track, and by moving the card and write/read head back and forth relative to the track direction, it is possible to access the data recording area. This has the effect of shortening time.

Moreover, since there is no clock bit in the set data track, the sector length of each data track can be arbitrarily determined depending on the length of the data to be recorded.

[Brief explanation of the drawing]

FIG. 1 is a front view showing the outline of the configuration of the first embodiment of the optical memory card of the present invention, FIG. 2 is an enlarged view of the section seen from arrow A in FIG. 1, and FIG. 4th perspective view showing the state of writing
The figure is an explanatory diagram showing an example of a data recording format applied to an optical memory card according to a second embodiment of the present invention. 1... Card board, 2... Optical recording medium, 3...
Clock bit, 3a, 3b...clock track, 4...data track, 5a, 5b...hole,
6...Writing head, TM...Track mark,
SM...Sector mark, DF...Data field, RSID...Right sector identification section, RSID...Left sector identification section.

Claims (1)

[Scope of Claims] 1. Clock bits are arranged in a matrix in an optically readable pattern in a data recording area of an optical memory card, and the spaces between rows or columns constituted by these clock bits are used as data storage tracks, In addition, the data storage track is provided with track mark setting sections at both ends thereof, and the area sandwiched between the track marks is divided into a plurality of sectors by sector marks, and both ends of the data field in each sector are divided into a plurality of sectors. In addition, a sector identification section with identification information such as a track number and a sector number indicating the address information of the sector is placed on the left side so that it can be read from the left side, and on the right side so that it can be read from the right side. An optical memory card characterized by having a setting that allows information to be written symmetrically.