JPH0554189B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an optical disc-shaped recording medium. Various types of optical discs are known in the art, including those called video discs, audio discs, and data discs. Video signals, audio signals, and data signals encoded in spiral or concentric information tracks are recorded on these optical disks as optical information such as optical transmission characteristics, reflection characteristics, and phase characteristics. The information recorded on these optical disks can be recorded by rotating the optical disk 1 with a spindle 2 at a speed of, for example, 1800 revolutions per minute, as shown in FIG. Light emitted from a light source 4 such as a laser is focused and projected onto the information track 3 by a lens 5, a half mirror 6, a reflecting mirror 7, and an objective lens 8, and the reflected light modulated by the information track 3 is projected onto the objective. The light is condensed by a lens 8 and reflected by a reflecting mirror 7 and a half mirror 6, which passes through a lens 9 and is detected by a light receiving device 10, thereby being reproduced. The elements 4 to 10 are supported by a pickup 11 and are configured to be movable together in the radial direction of the optical disk 1, so as to sequentially scan the information track in the radial direction. In addition, when recording information on the optical disk 1, for example, in the optical system shown in FIG.
0 is removed, a modulator is placed between the light source 4 and the objective lens 8, the light source 4 emits light with stronger energy than during reproduction, and this light is modulated by the modulator based on the information to be recorded. optical disk 1
The information is projected from the inner circumference to the outer circumference or from the outer circumference to the inner circumference, forming a spiral or concentric information track on the optical disk 1. One of the features of such optical discs is that they have a very high information recording density. For example, diameter 30
cm optical disc can record 54,000 tracks on one side.
If one frame is one track, 54,000 images can be recorded. In addition, document information can be recorded on approximately 20,000 sheets by compressing the bandwidth of A4 size information. In order to search for desired information from such a highly densely recorded optical disc, it is necessary for the user to be able to understand the state of the information recorded on the optical disc. The information area representing the state of this information will be referred to as an index hereinafter. Such an index is generally recorded by providing an index area on a part of the optical disc, for example, on the innermost or outermost circumference. On the other hand, when filing documents, still images, etc. onto optical disks, (1) not only information is recorded all at once;
As new information is collected, it is additionally recorded on the unrecorded part of the optical disk where the information is already recorded. (2) Correcting the information once recorded on the optical disk. (3) Information once recorded on the optical disk. Requests such as deletion of information, etc. However, although a permanent disk such as a metal thin film is generally used as an optical disk, once information is recorded on this optical disk, the information cannot be erased. As a method for recording information on such an optical disk so as to satisfy the conditions (1) to (3) above, if information is recorded from the inner circumference to the outer circumference of the disk, for example, the method shown in Fig. 2 is used. As shown, an index area 22, an information recording area 23, and an additional information recording area 24 are set in order from the inner circumference to the outer circumference in the radial direction of the optical disk 21, and the index area 22 has an information recording area 23. Indexes a ₁ to a _n of information to be sequentially recorded in the area are sequentially recorded via spaces S ₁ , ..., S _n-1 , and additional information is recorded between the last index a _n and the information recording area. Area 24
It is conceivable to provide a space S _n for recording an index of information to be newly added and recorded. In this way, the index of the additional information recorded in the additional information recording area 24 can be recorded in the space S _n , so the above (1)
can satisfy the requirements of In addition, (2) above,
Regarding (3), each index a ₁ , ..., a _n is, for example, flag + control + track address +
If file numbers + comments are used as the basic format and recorded as one document and one index, corrections and deletion indexes can be recorded in bases S ₁ to _{S n} as necessary, so these requirements are satisfied. be able to. However, in this recording method, there are many parts that are not recorded within one track, so the tracking signal for correcting the relative positional deviation between the objective lens and the track is interrupted, and the frequency of spaces S ₁ to _{S n-1} is Near the tracking frequency (0 to 10 KHz) band, this is mixed into the tracking signal, making it impossible to perform accurate tracking control. Moreover, even if the frequency of occurrence of erasure/correction differs for each document, the spaces S ₁ to S _n-1 need to be set assuming the maximum number of occurrences, resulting in wasted space. SUMMARY OF THE INVENTION An object of the present invention is to provide an optical disk-shaped recording medium that can eliminate the various problems described above, efficiently record an index representing the state of recorded information, and also accurately obtain a tracking signal. It is something to do. The present invention provides a first index area in which a main index representing the information is recorded when information is sequentially recorded, and a second index area in which an added, deleted or corrected index is recorded after the time at which the main index is recorded. The first index area is set separately from the second index area in the radial direction of the optical disc-shaped recording medium. The present invention will be described in detail below with reference to the drawings. FIG. 3 is a plan view showing an example of a recording area on the optical disc-shaped recording medium of the present invention. In this example, the optical disc 31 is scanned from the innermost circumference to the outer circumference to form an information track in a spiral shape. On the optical disk 31,
In the radial direction from the inner circumference to the outer circumference, there is a main index area 32 and an additional index area 3.
3. The deletion/correction index area 34, the information recording area 35, and the additional information recording area 36 are sequentially distinguished and set. In addition, the main index area 32 and the deletion/correction index area 3
Guard bands 37 and 38 for jitter correction and tracking, which have no meaning as information, are provided on at least the first track of 4, respectively. Main index area 32 For example, when filing an A4 size document, information can be recorded on up to 20,000 pages, but if you plan to record additional information and record information on 15,000 pages at a time, These 15,000 indexes are recorded sequentially and continuously. For example, when recording the index of one document using the format of flag + control field + track address + file number + comment, if the comment information is 20 characters, it can be processed within 250 bits at most, so 20,000 sheets can be recorded. Even if you file a document of 2×10 ⁴ ×2.5×10 ² =
5×10 ⁶ (bits), 2×10 ⁵ per track
If bit information can be recorded, it would be sufficient to allow for an area of 25 tracks. A predetermined start code (for example, 00111) is inserted at the beginning of the main index along with a flag, and a predetermined stop code (for example, 10110) is inserted at the end of the main index along with a flag. In addition, the guard band 37 of the first track is a predetermined dummy code (for example,
10000) is recorded repeatedly with the flag. This also applies to the guard band 38. The recording mode of this main index area 32 is shown in FIG. Note that although the index start and stop codes are each recorded once in FIG. 4, they may be recorded multiple times so that no reading is missed during playback. Additional Index Area 33 When information is additionally recorded in the additional information recording area 36, an index of that information is recorded here. In this case, index start and stop codes are inserted before and after the additional index as shown in FIG. In this way, by recording an index stop code at the end of one lot recording, by reading this, the next additional index can be recorded without using a space. Deletion/Correction Index Area 34 An index indicating deletion or correction of information recorded in the information recording area 35 and additional information area 36 is recorded here. The correction information sets an erasure code (for example, 01000) and is composed of, for example, a flag+erasure code+index information as shown in FIG. 6A. In this case, the index information records the track address and final number of the information to be deleted recorded in the main index area 32 and/or additional index area 33. In addition, the correction information is set by setting a correction code (for example, 11001), and for example, as shown in FIG. 6B, the flag + correction code + index information +
Configure with new index information. In this case, the index information records the track address and final number of the information to be corrected recorded in the main index area 32 and/or additional index area 33, and the new index information records the corrected information. (Since this is a correction, the final number is the same as the one recorded in the main index.) As shown in FIGS. 7A and 7B, these deletion information and correction information are recorded by inserting an index start and a stop at the front and rear ends, respectively, as in the case of the additional index described above. Information recording area 35 In this area, document information of the index to be recorded in the main index area 32 is recorded, for example, with a track address attached to each track and a file number attached to each document information. Additional information recording area 36 Document information of the index to be recorded in the additional index area 33 is recorded here, for example, in the same manner as the recording method in the information recording area 35 described above. The information recorded on the optical disk is accessed by software copying or the like, and the track address and file number of the necessary information are keyed in by referring to the index. FIG. 8 shows the configuration of an example of a display device in this case. First, the main index signal is read from the optical disk, and the error check circuit 41 checks whether there are any errors in the signal. This checking method includes, for example, CRCC (Cyclic Redundancy Check Code).
If there is no error, the flag detection circuit 42 detects the flag code from the main index information string, locates the beginning of the information string, and the control field decoder 43 detects the 5-bit control signal after the flag code. The control field decoder 43 controls an address register 44, a final number register 45, and a comment register 46 in accordance with the detected control signal, and stores the track address, file number, and comment following the control signal in each register, respectively. By repeating this operation, all the index information recorded in the main index area is stored in the storage and comparison/correction circuit 47. After that, the erasure/correction index area is scanned, and the track addresses, file numbers, etc. are classified using the same operations as above, and compared with the track addresses and file numbers stored in the storage and comparison/correction circuit 47. Then, in response to the erasure/correction command read by the control field decoder 43, erasure/correction information is added. The main index information and deletion/correction information stored in the memory and comparison/correction circuit 47 are sent through the format circuit 48.
Display on CRT49. As described above, according to the optical disc recording medium of the present invention, various indexes can be efficiently recorded without providing intermittent spaces within one track, and since the required track is not interrupted, tracking control is possible. can also be carried out accurately, and the object of the present invention can be effectively achieved. Note that the present invention is not limited to the above-mentioned example, and can be modified or modified in many ways. For example, in Fig. 3, the main index area, additional index area, erasure/correction index area, information recording area, and additional information recording area are set sequentially in the main scanning direction of the pick-up. Any order may be used as long as they are set differently in the radial direction of the disk. Also, a guard band is not necessarily necessary.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of an example of an optical disc device, FIG. 2 is a diagram illustrating a recording medium on which addition, deletion, and correction indexes can be recorded, and FIG. 3 is a diagram showing an optical disc according to the present invention. FIG. 4 is a diagram showing an example of the recording mode of the main index area shown in FIG. 3, and FIG. 5 is a plan view showing an example of the recording mode of the additional index area shown in FIG. A diagram showing an example, FIGS. 6A and B are diagrams showing the configuration of an example of erasure information and correction information according to the present invention, and FIGS.
FIGS. A and B are diagrams showing an example of the recording mode of erasure and correction information, respectively, and FIG. 8 is a block diagram showing the configuration of an example of a display device for various indexes recorded according to the present invention. 31... Optical disk, 32... Main index area, 33... Additional index area,
34...Deletion/correction index area, 35...
...Information recording area, 36...Additional information recording area, 37, 38...Guard band.

Claims (1)

[Claims] 1. A first index area for recording a main index representing the information when sequentially recording the information, and a second index area for recording an index added, deleted, or corrected after the time at which the main index is recorded. An optical disc-shaped recording medium, wherein the first index area is set to be distinguished from the second index area in the radial direction of the optical disc-shaped recording medium.