JPH02208888A - Residual time display device for optical disk player or the like - Google Patents

Abstract

PURPOSE:To accurately detect the time of music end in a short time by retrieving the music head of the next music first according to index information at the time of detecting the time of the music end of desired music, and after that, retrieving the music end of the desired music. CONSTITUTION:The music head time of a music number (N+1) next to a music number N read out from the index information is recorded, and a pickup is moved at high speed in a forward direction advancing a position corresponding to music head time, and the pickup is jogged and moved repeatedly in a reverse direction advancing a music number switching point switching from the music number N to the music number (N+1) corresponding to the completion of movement. Time information and the music number recorded at a moving point at every fine movement are read, and the time when it arrives at the switching point where the music number is switched is recorded as the time of the music end. In such a way, it is possible to accurately detect the completion time of the music to be played.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a remaining time display device for a CD player or the like.

(Prior Art) In the data area of a compact disc (hereinafter referred to as a CD), the song number is periodically recorded for each recorded song, and time information (A time )
is recorded. Furthermore, in the table of contents area (TOC) on the innermost circumference, the start times of these songs, that is, time A at the beginning of the songs, are recorded as table of contents information in correspondence with the respective song numbers.

Therefore, when displaying the remaining time of the song currently being played on a CD player, etc., the A time at the start point of the next song obtained from the table of contents information is taken as the time at the end of the song, and this time and the time remaining in the song currently being played are used. This is compared with the A time recorded at the position and displayed as the remaining time.

(Problem to be solved by the invention) However, with CDs, even when the previous song ends and the song number switches to the next song number, the new song does not start immediately; There is an appropriate pause period between the beginning of the next song.

Therefore, if the calculation is performed using the time at the beginning of the next song, the remaining time displayed will be the value added to the above pause section,
It will be displayed for a longer period of time.

The present invention has been made to solve these problems, and is intended to accurately detect the time at the end of a song in order to calculate the remaining time in an optical disc player or the like.

[Means to solve the problem]

The remaining time display device for an optical disc player or the like according to the present invention includes a means for setting a song number N to be played, and a means for setting the start time of the song number N+1 next to the song number N read from the table of contents information of the optical disk or the like. means for recording, means for moving the pickup at high speed in the forward direction toward a position corresponding to the start time of the song on the optical disc, and song number switching for switching the pickup from song number N to N+1 upon completion of the movement. A micro-movement means that repeatedly moves in the opposite direction in small increments toward the desired point, a means for reading the time information and song number recorded at the movement point for each micro-movement, and a means to read the time information and song number recorded at the movement point for each micro-movement. The present invention is characterized in that it has a means for detecting that a switching point has been reached, and records the time at which the switching point is reached as the time of the end of the song.

[Effect]

In this way, when detecting the end time of a desired song, the start of the next song is first searched according to the table of contents information, and then the end of the desired song is searched, so that the time of the end of the desired song can be detected accurately in a short time. The tail time can be detected.

〔Example〕

FIG. 1 is a block diagram showing one embodiment of the present invention.

In the figure, optical information from a CDI rotated by a motor 10 is detected by a pickup 2 and applied to a detection signal processing section 3. The detection signal processing section 3 applies a tracking error signal to the tracking servo circuit 6 and also applies EFM47s to the digital signal processing section 4. The digital signal processing section 4 demodulates the digital data of the music signal and outputs it to the output terminal 5, and also outputs the subcode Q.
The information is demodulated and added to the microcomputer 8. A tracking servo circuit 6 controls a tracking coil that drives the objective lens of the pickup 2, and also controls a slide servo circuit 7. The slide motor 9 is a slide control circuit 7
The pickup 2 is controlled to slide. The microcomputer 8 includes a digital signal processing section 4. The tracking servo circuit 6 and the slide servo circuit 7 are controlled.

The operation of the above configuration will be explained in detail below with reference to the flowchart of FIG.

When a desired song number N is specified, it is necessary to know the end time of the song, that is, the time of the end of the song, in order to display the remaining time before starting the performance of that song. For this reason, as shown in Fig. 2, the time at the beginning of the next song number N+1 is read from the table of contents information that is read out from the TOC of the CD and recorded, and this is recorded. Instructs to start a seek operation to search for the head (S+). If the target song is located in the outer circumferential direction, the pickup should be moved in the outer circumferential direction, for example, in the trunk 10.
Start moving at high speed, jumping over 0 lines at a time.

In this case, every time 100 tracks are skipped, the absolute time (A
time) and also read out the song number (SZ
), the read A time is recorded in WORKAREA as a -time storage area (Ss), and such song number and recorded A time are compared with the time at the beginning of the song number N+1 described above. If the newly created song number matches N+1 or the A time matches or exceeds the time at the beginning of this song, it is determined that the song number N+1 has been reached (S4). . If it is not determined that the next song, that is, the beginning of the song number N+1, has been reached, it will be 5ee until the next song arrives.
Do the above S while doing k movements! -Repeat steps s4. In this manner, when it is determined in S4 that the beginning position of the music number N+1 has been reached, the process moves to the next step and an operation is performed to search for the end position of the music number N.

Therefore, in the following steps, each track is read one by one, and it is determined at S whether the current song number N+1 has changed to the desired song number N. If the read song number remains N+1 (Ss), the A time at this time is recorded in WORKAREA (S,), and one track is kicked in the opposite direction (reverse kick).
S? ), the subcode Q at that position is read out (
Sa).

The steps S to S8 are repeated until it is determined that the song number of the subcode Q read in this way becomes the song number N at S.

When the song number read in S8 changes from N+1 to N,
The A time at this time is compared with the A time recorded in WORK just before being reverse kicked by Sma (
If there is a difference of more than 1 second, it will be determined that there was a major mistake in the reverse kick and the entire process will be repeated. If the difference is less than 1 second, it will be read out at the end in S. Determine A time as the end time of song number N,
Used to display remaining time.

Note that if the song number N is the final song, song number N+1 does not exist, and there is no pause section at the end of the song. Therefore, in this case, the lead-out start time (corresponding to the total recording time), which is the beginning of the next song for the last song, is used as the end time, and the remaining time is displayed.

In order to calculate the switching point of such a song number more precisely, in step S, after detecting the track that changes to the song number N, as shown in Figure 3, Trace in the direction to read the A time (S,), and once again reach the song number N+1 (S+g), record this person's time. The time obtained by subtracting the time for one frame from this A time is set as the time of the final frame of song number N (S13
), it is possible to know the time of the switching point very accurately.

〔Effect of the invention〕

As described above, according to the present invention, the end time of the piece of music to be played can be detected extremely accurately.

[Brief explanation of the drawing]

FIG. 1 shows a block l/circle and a second block showing an embodiment of the present invention.
The figure shows the flow-F, and FIG. 3 is a flowchart showing a modification of FIG. 1. 1...CD 2...Pickup 3...Detection signal processing unit 4...Digital signal processing unit 6...Tracking servo circuit 7...Slide servo circuit 8...Microcomputer 9...Slide motor

Claims (1)

[Claims] A means for setting a song number N to be played, and a song number N next to the song number N read from table of contents information on an optical disc, etc.
means for recording a track start time of +1; means for moving the pickup at high speed in the forward direction toward a position corresponding to the track start time on the optical disc; and means for moving the pickup from track number N to N+1 upon completion of the movement. micro-movement means for repeatedly moving in small increments in the opposite direction toward a song number switching point; means for reading time information and song numbers recorded at the movement point for each micro-movement; A remaining time display device for an optical disc player, etc., comprising means for detecting that the pickup has reached the switching point due to a change, and recording the time at which the switching point is reached as the time at the end of the song. .