JPH0498656A - Discriminating method for track format - Google Patents

Abstract

PURPOSE:To discriminate a track format simultaneously with the read of data by recognizing the length of one sector constituting a track simultaneously with the read of information in the track. CONSTITUTION:An encoder counter 22 uses the pulse signal of a rotary encoder 15 as a clock and the count value is inputted to a format judging circuit 24. In the format judging circuit 24, the relative position of an optical head 9 to an optical card 1 can be recognized from the output of the encoder counter 22. On the other hand, a demodulation signal demodulated by a demodulation circuit 17 is supplied to a controller 16 and simultaneously supplied to an identification information recognizing circuit 23 as well. Thus, the format can be discriminated simultaneously with the read of data.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for determining track formats. In particular, the present invention relates to a method for determining track formats. In particular, the present invention relates to a method for determining a track format. record,
The present invention relates to a method for determining the type of track format used to record recorded data when reproducing recorded data.

[Prior art] Optical cards have a large storage capacity of 1 to 2 Mbytes.
There are various application ranges. In order to use this large storage capacity more effectively, data is recorded/reproduced using multiple types of formats.

When recording data on an optical card, the data is divided into blocks for each unit time in a predetermined sequence of the format used for recording the data, and recorded on tracks on the optical card. , and an error correction code for correcting data errors caused by scratches on the recording medium, etc., constitute a - sector. Therefore, when playing back data, if you do not know in advance or after reading the data in which format the data was recorded on the track, you must rearrange the data in a predetermined sequence according to that format and correct the error. If you do not do this, you will not be able to accurately reproduce the data.

FIG. 4 is a plan view of a conventionally used optical card. The optical card 1 includes an optical recording section 2 having a plurality of tracks parallel to each other, and an end portion (right side or /) of the optical recording section 2.
and the left side) is provided with an ID section 3 in which information indicating track addresses corresponding to the respective tracks is recorded.

In a conventional optical card, a part of the tracks provided in the optical recording section 2 is used as a management track for managing the track format used when recording data on each track (information recording track). That is, in the tracks in the management track area 4, data indicating which format was used to record the information recorded in the information recording track is recorded.

FIG. 5 is a diagram showing an example of a track format. Sector marks indicating sector divisions are not recorded on the information recording track. Therefore, when recording data, any format can be used for each information recording track. Three types of track formats are shown here. Format A is 6
Each sector 5 constitutes one track. Three sectors 5 for format B and two sectors 5 for format C each constitute one track, and the sector intervals differ depending on the type of format. Identification information 6 is recorded between sectors 5 and 5, and as shown in an enlarged view of a part of format C, each identification information 6 contains synchronization information for synchronization when reading data. The pattern 7 and the sector address 8 of the next recorded sector 5 are recorded, and by reading this identification information, the end of each sector 5 can be detected.

As shown in FIG. 6, the optical recording section 2 of the optical card 1 is provided with 2000 tracks.
Among 000 tracks, track addresses 0 to 19
20 tracks are assigned to the management track area 4. The remaining 1980 tracks (track addresses 20 to 1999) are for recording information and are divided into 99 areas of 20 tracks each. Information is recorded on the 20 tracks in the area marked - using the same format.

After recording data in the first area, the type of format used to record this data is recorded in the first sector of the track with track address 0 in the management track area 4. Similarly, after data is recorded in the second area, the format used to record this data is recorded in the second sector of the track with track address 0 in the management track area 4. Similarly, the third area and the fourth area 19. and each time you record data,
The format used to record the data is sequentially recorded on the tracks in the management track area 4.

FIG. 7 is a diagram showing the overall configuration of a conventional optical card recording/reproducing apparatus using the conventional optical card described above. Data is recorded/reproduced by moving the optical card 1 in the track direction and moving the optical head 9 in a direction perpendicular to the tracks. Optical card 1 has pulley IOA, 108
The interlock is loaded onto a shuttle 12 provided at a predetermined position on a conveyor belt 11, and is conveyed back and forth in the track direction by a motor 14 under the control of a motor servo circuit 13. A rotary encoder 15 is attached to the motor 14, and the shuttle 12 relative to the optical head 9 is
It is possible to detect the position of For example, one pulse of the rotary encoder 15 corresponds to a moving distance of 50 μm of the shuttle 12 with respect to the optical head 9.

The output of the rotary encoder 15 is
Based on the position information of the shuttle 12 from the rotary encoder 15, the controller 16 controls the motor servo circuit so that the transport speed of the optical card 1 is constant between the information recording areas of the optical card l. A control command is sent to 13.

The configuration of the optical head 9 is as follows. The light from the laser diode 9A is projected onto the optical card 1 via the prism 9B and the objective lens 9C, and the reflected light from the optical card 1 is projected onto the detector 9D via the objective lens 9C and the prism 9B.
Inject it into the The output of the detector 9D is the demodulation circuit 17
The read signal is obtained at two points. On the other hand, the output of the detector 9D is the focus track servo circuit 1.
8, the focus error signal and the track error signal are detected here, and based on these signals,
At least the objective lens 9C is driven in the focus lens direction and in the tracking direction via an actuator (not shown) to control the incident light so that it always follows the track of the optical card 1 in a focused state.

The controller 16 controls the modulation circuit 1 during data reproduction.
9 is left in an unmodulated state, a low output reading light is output from the laser diode 9A via the laser drive circuit 20, and the motor servo circuit 13 and the demodulation circuit 17
, and the focus/track servo circuit 18 to read data demodulated by the demodulation circuit 17.

Furthermore, when writing data, the modulation clock circuit 21 generates a synchronous clock for writing data in accordance with the output signal from the rotary encoder 15, and supplies this to the modulation circuit 19. The modulation circuit 19 transfers the write data from the controller 16 to the modulation clock circuit 21.
The laser diode 9A is modulated into desired data according to the synchronization clock generated by the laser diode 9A via the laser drive circuit 29 in response to the second modulation signal, and data is written.

FIG. 8 is a flowchart showing the data reproducing operation performed in the optical card recording/reproducing apparatus described above. The data recorded on each track is programmed in a predetermined sequence in the format used to record the data, so to perform error correction, read the data and then read the blocked data. Is it necessary to rearrange the normal data? In the past, in order to determine the format used to write the data to be reproduced, the controller 16 first moves the optical head 9 from the current track to the management track and reads the target track recorded on the management track. format data needs to be read. Next, the optical head 9 is moved from the management track to the target track to read data recorded on the target track. The data read here is stored in a buffer memory in the controller 16 for each block forming a sector. The controller 16 selects a predetermined sequence of the format from the format data read by scanning the management track, and rearranges the data and corrects errors. The data for which error correction has been completed is transferred sector by sector to the host computer via an interface, for example.

[Problems to be Solved by the Invention] As mentioned above, conventionally, in addition to the track for recording information, it is necessary to provide a management track for managing the format on an information recording medium such as an optical card. there were. Therefore, the information recording capacity was limited by the number of tracks used as management tracks. In addition, in order to recognize the track format used to record the data to be reproduced, each time the area or track changes, the optical head is moved from the track the optical head is currently on to the management track, and the data is recorded on the management track. There was a need to read format information. therefore,
It takes time to read this format information,
Furthermore, there was a problem in that the time required to reproduce the information became longer.

In view of the problems of the prior art, the present invention attempts to provide a track format determination method that can perform track format determination at the same time as data reading without providing a management track in the information recording section. It is something.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the track format determination method of the present invention provides a method for determining the track format of the information recorded in an information recording area provided on an information recording medium. In the method for determining the type of track format used for recording, the method comprises: (2) reading the information of the track recorded in the information recording area and simultaneously recognizing the length of one sector constituting the track; This method is characterized by determining the type of track format.

[Function] According to the track format determination method of the present invention, the type of track format used to record the data can be determined at the same time as data is read. There is no need to provide an area, and the information storage capacity can be expanded accordingly. Further, in order to obtain format information, there is no need to return the optical head to the management track and read the format management information, thereby making it possible to shorten the reading time.

[Embodiment] FIG. 1 is a diagram showing the configuration of an example of an optical card recording/reproducing apparatus for implementing the track format discrimination method of the present invention. The second device is the conventional optical card recording/reproducing device shown in FIG. 7, except that an encoder counter 22, an identification information recognition circuit 23, and a format determination circuit 24 are added. Since this device is the same as the device shown in FIG. 7, the same parts as those in the device shown in FIG.

The encoder counter 22 is the rotary encoder 15
The counter uses a pulse signal of 1 as a clock, and the counter value is input to the format determination circuit 24. The format determination circuit 24 can determine the relative position of the optical head 9 with respect to the optical card l from the output of the encoder counter 22. As described above, one pulse of the rotary encoder 15 corresponds to a moving distance of 50 μm of the shuttle 12 with respect to the optical head 9. For example, if the output of the encoder counter 21 is 20, the optical head 9
This means that the optical card has moved by about 1 point relative to the optical card l.

On the other hand, the demodulated signal demodulated by the demodulation circuit 17 is supplied to the controller 16 and also to the identification information recognition circuit 23 at the same time. The identification information recognition circuit 23 recognizes from the information of the synchronization pattern 7 and the sector address 8 whether it is a demodulated signal, a signal representing data, or a signal representing identification information,
When the identification information is obtained, the format determination circuit 24 is notified of the identification information signal and the sector address value.

In the format judgment circuit 24, the identification information recognition circuit 22
The format of the recording data is determined from the sector address value when the identification information signal is obtained from the encoder counter 22 and the value of the encoder counter 22, and a predetermined format determination signal corresponding to this format is activated to determine the format. signal to controller 1
Supply to 6.

A decoding circuit is shown in FIG. 2 as an example of the format determination circuit 24. The decoding circuit shown in FIG. 2 uses encoder counter 2 when sector address identification information is obtained.
5, the count value is 40 to 47 (format B). Sector address value is SA5~SA
It is represented by 6 pits of O, and the encoder counter value is also EC
It is represented by 6 bits from 5 to ECO.

FIG. 3 is a flowchart showing the track format discrimination operation according to the track format discrimination method of the present invention. The optical head is moved to the target track, the track is optically scanned, and the read signal is demodulated by the demodulation circuit 17 and sent to the controller 1.
6 and stored in the buffer memory, and simultaneously input to the identification information recognition circuit 23. When the identification information recognition circuit 23 recognizes the identification information 6, it outputs the identification information signal and the sector address number recorded in the identification information to the format determination circuit 24.

In the format judgment circuit 24, the identification information recognition circuit 23
It receives an identification information signal and a sector address number from the encoder counter 22, and also receives a counter value from the encoder counter 22. The sector address value and counter value are decoded to determine the format type, and this format signal is applied to the controller 16. For example, if the sector address, the identification information of 1, or the output of the encoder counter 25 is obtained when it is around 80 (nearly a movement distance of 4 mm), it can be determined that the track is in format A shown in FIG. A format signal representing the format is sent to the controller 16.

The controller 6 uses this format signal to
The type of format used to record the data to be reproduced can be recognized, and the data stored in the buffer memory in the controller 16 is rearranged in a predetermined sequence of the format to perform error correction. After error correction is performed in this manner, the data is divided into sectors and transferred to a host computer (not shown).

The present invention is not limited to the embodiments described above,
Many variations or modifications are possible. For example, in the above-mentioned embodiment, the format determination means is configured by a decoding circuit, or is configured to generate an interrupt to the CPU in the controller 16 when the identification information is output from the identification information recognition circuit 23. CPU or encoder counter 2
The format may be determined by software by taking in the counter value and sector address value from 2.

[Effects of the Invention] According to the track format determination method of the present invention, the format can be determined at the same time as data is read, so there is no need to provide a management track for managing the format of each track. Therefore, the tracks in the optical recording section that were conventionally assigned to management tracks can also be used for data recording, and the information storage capacity of the optical card can be expanded. Furthermore, unlike the conventional method, it is no longer necessary to move the optical head to the management track in order to determine the format, so the information reading time can be shortened.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the overall structure of an example of an optical card recording/reproducing device for implementing the track format identification method of the present invention, and FIG. 2 is a diagram showing the format determination circuit of the device shown in FIG. 3 is a flowchart showing the track format discrimination operation of the present invention. FIG. 4 is a plan view of a conventional optical card. FIG. 5 is a diagram showing an example of the track format. , a diagram showing an example of the configuration of a track format of a conventional optical card; FIG. 7 is a diagram showing an entire optical card recording/reproducing apparatus for carrying out a conventional track format identification method; FIG. 2 is a flowchart showing a conventional track format identification operation. 1... Optical card 2... Optical recording section 3...
・ID section 4...Management track area 5・
... Sector 6 ... Identification information 7 ... Synchronization pattern 8 ... Sector address 9 ... Optical head 12 ... Shuttle 3 ... Motor servo circuit 5 ... Rotary encoder 6 ... Controller 17... Demodulation circuit 8...
Focus track servo circuit 9...Modulation circuit
20...Laser drive circuit 1...Modulation clock circuit 2...Encoder counter 3...Identification information recognition circuit 4...Format judgment circuit Fig. 1 F-2 Direction 2 Fig. 5 @Figure 7

Claims (1)

[Claims] 1. A method for determining the type of track format used to record information when reproducing information recorded in an information recording area provided on an information recording medium,
A method for determining a track format, characterized in that the type of the track format is determined by reading information on a track recorded in the information recording area and simultaneously recognizing the length of one sector constituting the track. .