RECORD INFORMATION REPRODUCING METHOD WITH CONTENT IDENTIFIERS

Abstract: A method of operating a disk player that reproduces in­ formation recorded on a disk. Programs on the disk are addre­ ssed from a directory in a memory and the programs are sequentially accessed according to the order in the directory. The directory can be filled by inserting random numbers or by scanning through the programs or over the tracks. A table of contents at the beginning of the disk is read if possible. The tracks can be scanned and only tracks having new programs are reproduced. Also a playback position servo operates with a dead-zone in the drive voltage.

Description: The present invention relates to a reproducing method for recorded information and, more particularly to a reproducing method for recorded information by which each of a plurality of pieces of program information recorded in a recording medium is allocated in advance to have its address information stored in a memory so that the pieces of program information may be reproduced in the order of storage in response to the operation of a memory play key. There is known a method for reproducing a recording medium, which is recorded with a plurality of pieces of program information, such as a digital audio disk. According to the known method, arbitrary program information is allocated in advance to have its address information stored in a memory so that the pieces of program information are reproduced in the order of storage. It is also known (see EP-A-0 181 020) to provide a disk player with a memory into which the addresses of pieces of music on plural disks can be stored, so that, when a "memory play" mode is used when the disk is inserted again, the pieces are played in the order in which they were stored. In this reproducing method, according to the prior art, the reproduction is not started from other than the program information corresponding to the address information stored first in the memory, when that memory play mode is selected. As a result, the same program information is started every time the memory play mode is selected so that reproduction of the same program information is always repeated if the "memory play" mode is selected. The present invention has been conceived in view of the point described above and has an object to provide a recorded information reproducing method in which program information to be first reproduced can be changed sequentially each time a memory play mode is selected. According to the present invention, there is provided a method of reproducing recorded program information from a recording medium on which are stored plural pieces of program information, the method comprising storing in a memory a plurality of program addresses corresponding to selected pieces of program information on the recording medium, the program addresses being stored in order in the memory; and reproducing programs using the stored program addresses; characterised by retrieving one of the program addresses from the memory by means of a reference pointer pointing thereto; moving the pointer to reference the next one of the program addresses in the order; reproducing a program from the recording medium associated with the one program address retrieved by means of the pointer; and, repeating the retrieving, moving and reproducing steps such that programs associated with at least a portion of the addresses in the order in the memory are reproduced. One example of a method and apparatus according to the present invention will now be described with reference to the accompanying drawings, in which:- Fig. 1 is a block diagram showing a control system, of a reproduction system, eg. for a CD player; and, Figs. 2 to 4 are flow charts for explaining the operations of the control system shown in Fig. 1. The control system follows the following routine: on commencement of playing, as shown in Fig. 2, it is firstly judged at step 1, on the basis of the output of the detecting switch 110, whether or not the pickup 117 (as shown in Fig. 29) is in its home position. If YES, the pickup 117 is focused (at step 2) to start it reading operation. At step 3, moreover, an information recording start position or the read-in area of the disk 5, i.e., the TOC (which is the abbreviation of "Table of Contents") position is calculated on the basis of address information obtained by the pickup 117. The TOC is recorded with pieces of formatting information such as the number or total absolute time of pieces of music stored in the disk or the play time of each piece of music. It is preferable to read out the recorded information of the TOC at the start of the play. For the method for calculating the TOC position (or a target address) from the present address, an exemplary method has been proposed in Japanese Patent Application No. 58 - 202994 by the present applicant. This method repeatedly calculates the distance to a target address to move the pickup 117 until the distance to the target address comes to a constant value, by making use of the fact that the distance to the target address can be more accurately obtained as the target address is more closely approached. If the TOC position is calculated at step 3, the pickup 117 is moved (at step 4) to the TOC position, and a timer built in to the control circuit 111 and having a constant time period Ta (e.g., 15 seconds) is subsequently set (at step 5). At step 6, it is judged whether or not the aforementioned constant time Ta has elapsed. If NO, the contents of the TOC are read out (at step 7). Subsequently, it is judged (at step 8) whether or not the read-out of the TOC contents has been completed. If YES, the program area is searched (at step 9), and the operation is advanced to the playing operation. If it is judged at step 8 that the read-out of the TOC contents has not yet been completed, the aforementioned operations are repeated by returning to step 6. If it is judged at step 6 in those repeated operations that the aforementioned time period Ta has elapsed, the operation skips to step 9 to come into the playing operation by assuming that there is an error in the read-in area, for example, such as to cause the "hang-up". As a result, the operation can be prevented from causing the hang-up to enter an endless loop by the error in the read-in area. Even if the TOC contents are not wholly searched, the sequence ends with lapse of the time period Ta so that the system can be smoothly operated. In a digital audio disk player, incidentally, each piece of program information can be searched even if the TOC contents can not be read out. If it is judged step 1 that the pickup 117 is not in its home position, the pickup 117 is brought (at step 10) to the home position by the carriage mechanism 13. The digital audio disk is recorded with a plurality of separate pieces of program information (such as music passages), so the player is given a memory play function to store the addresses of arbitrary pieces of music in the memory while operating it in advance to play the addressed pieces of music sequentially in the order in which their addresses are stored in that memory. The procedure for storing those allocated pieces of music in the memory will be described in accordance with the flowchart of Fig. 3. A scan mode is initiated by momentarily depressing (or turning on) a scan key (which is one of the grouped control buttons 6 of Fig. 1, although not shown by itself). In this scan mode, the head or beginning of each piece of music is played for a constant time (e.g., 10 seconds). If the lapse of 10 seconds is determined at step 11, the next piece of music is searched for (at step 12). These operations are conducted for all the pieces of music recorded. In the case, in this scan mode, in which it is judged at step 11 that the time of 10 seconds has not yet elapsed and at step 13 that the scan key has once again been depressed, the operation is advanced to step 14 so as to store the address of that piece of music in the memory. If the number of pieces of music that can be stored in the memory is denoted as N, it is judged at step 14 whether or not the memory has stored N-1 addresses for pieces of music. If NO, it is subsequently judged at step 15 whether or not the memory has stored N (i.e. the maximum storable number) addresses of pieces of music. If NO at step 15, the address information (e.g. a track number) of that music piece is stored (at step 16) in the memory, and the next piece of music is then searched (at step 17), until the operation returns to step 11. In the case in which it is judged at step 14 that the number of addresses of the pieces of music stored in the memory has reached the value N-1 on the display 116, is displayed (at step 18) the fact that the number of pieces of music to be stored in the memory is going to reach its limit value, and the operation is then returned to step 16 so that the address information of that music piece is stored in the memory. If, on the other hand, it is judged at step 15 that the number of addresses for music pieces stored in the memory has reached the value N, the address information of the oldest piece of music is erased (at step 19), and the operation is then returned to step 16 so that the address information of the latest piece of music is stored in the memory. In these ways, the allocated information on the music is stored in the memory. According to this method, the contents of the pieces of music to be stored in the memory can be confirmed, and the scan key can also be used for storing an address for a piece of music in the memory. Incidentally, this method is not limited in application to digital audio disks, but can be applied to a digital audio tape or further to a conventional audio tape if the count value between two pieces of music is used as the address information or if that tape has stored thereon the address information. Next, the operations in a memory play mode for sequentially playing the pieces of music whose addresses stored in the memory will be described in the following in accordance with the flow chart of Fig. 4. When in the memory play mode, it is first judged at step 20 whether or not an allocated piece of music is stored in the memory. That is, whether the memory contains addresses of pieces of music that have effectively been allocated. If YES, the data (e.g., the address information) which is pointed to at present by a pointer for selecting one of the plural allocated pieces of music in the memory is read (at step 21). Then, the pointer is advanced (at step 22) to the immediately preceding data, and the music having the read address thus allocated is then searched (at step 23) and thus played. Subsequently, if it is judged at step 24 that the play of the allocated music has ended and (at step 25) that the memory play mode is not yet released at that time, the operation returns to step 21, at which time the next allocated music pointed to by the pointer is played. These operations are subsequently repeated until it is judged at step 25 that the memory play mode is released. If it is judged at step 20 that there is no allocated music having addresses stored in the memory, the operation is advanced to step 26. At this step 26, allocated pieces of music are randomly allocated by having a random number stored in the memory as an address up to the capacity of the memory. Then, the first allocated music having an address stored in the memory is searched (at step 23), and operation returns to step 21. Steps 24 and 25 are subsequently repeated until it is judged at step 25 that the memory play mode has been released. Thus, by producing the addresses for the newly allocated pieces of music by a random number and by playing them in the order of allocation in case no allocated music has its address stored in the memory, it is unnecessary to display whether or not the memory is stored with addresses of allocated music, and the play can be made in any case if the memory play mode is selected. As a result, the usability can be improved. If the memory play mode is once released but restored, the operations from step 20 are repeated, as described above. Since, by this time, the pointer in the memory has advanced to the data next to that called previously, the play is started from the allocated music next to that played previously. As a result, even if the selection and release of the memory play mode are repeated, the music to be called is sequentially changed so that identical allocated music is not called each time of selection of the memory play mode. As has been described hereinbefore, according to the recorded information reproducing method of the present invention, the order of the address information to be called from the memory is stored in the memory play mode so that, in case the memory play mode is released and selected again, reproduction is started from the program information which corresponds to the address information next to that last called in the preceding memory play mode. As a result, the program information to be reproduced first is sequentially changed even if the selection and release of the memory play mode are repeated, so that identical information is not called each time the memory play mode is selected.

Claims: A method of reproducing recorded program information from a recording medium (5) on which are stored plural pieces of program information, the method comprising storing in a memory a plurality of program addresses corresponding to selected pieces of program information on the recording medium, the program addresses being stored in order in the memory; and reproducing programs using the stored program addresses; characterised by retrieving one of the program addresses (S21) from the memory by means of a reference pointer pointing thereto; moving the pointer (S22) to reference the next one of the program addresses in the order; reproducing a program (S23) from the recording medium associated with the one program address retrieved by means of the pointer; and, repeating the retrieving, moving and reproducing steps such that programs associated with at least a portion of the addresses in the order in the memory are reproduced. A method according to claim 1, wherein the repeating is continued until there is an indication that a memory play mode is released. A method according to claim 1 or claim 2, further comprising: determining if the memory contains stored addresses (S20); and, if the memory does not contain addresses, storing random numbers (S26) as the addresses in the memory. A method according to claim 1, wherein, after the storing step, the retrieving, moving and reproducing steps are sequentially followed in that order. Apparatus for reproducing recorded program information from a recording medium (5) on which are stored plural pieces of program information, the apparatus including means for storing in a memory a plurality of program addresses corresponding to selected pieces of program information on the recording medium, the program addresses being stored in order in the memory; and means for reproducing programs using the stored program addresses; characterised by means for retrieving one of the program addresses (S21) from the memory by means of a reference pointer pointing thereto; means for moving the pointer (S22) to reference the next one of the program addresses in the order; means for reproducing a program (S23) from the recording medium associated with the one program address retrieved by means of the pointer; and, means for repeating the retrieving, moving and reproducing steps such that programs associated with at least a portion of the addresses in the order in the memory are reproduced.

Inventors: ABE, HIROYUKI C/O PIONEER ELECTRONIC CORP., AOYAGI, YOSHIO C/O PIONEER ELECTRONIC CORP., HAENO, AKIRA C/O PIONEER ELECTRONIC CORP., IIJIMA, TAKAYUKI C/O PIONEER ELECTRONIC CORP., KIMURA, TOSHIYUKI C/O PIONEER ELECTRONIC CORP., KOBAYASHI, KIMITO C/O PIONEER ELECTRONIC CORP., MATSUMOTO, ISAO C/O PIONEER ELECTRONIC CORP., NAGASHITA, TSUNEYOSHI C/O PIONEER ELECTRONIC CORP., NAMIKI, AKIO C/O PIONEER ELECTRONIC CORP., NIINUMA, SUSUMU C/O PIONEER ELECTRONIC CORP., NOMURA, ISAMU C/O PIONEER ELECTRONIC CORP., SHIMOKAWA, KAZUTO C/O PIONEER ELECTRONIC CORP., WATANABE, YOSHIHIKO C/O PIONEER ELECTRONIC CORP.
Applicants: PIONEER ELECTRONIC CORPORATION
Application year: 1986
Main classification: G11B27
IPC codes: G11B7, G11B27, G11B33, G11B17, G11B21