JPH0447838Y2 - - Google Patents

Description

[Detailed explanation of the invention] (a) Industrial application field This invention is a compact device that reads information without contact.
This invention relates to an index search device for a disc player.

(b) Conventional technology In a compact disk digital audio system, there is an area called a lead-in area on the innermost circumference of the disk, and within this area there is a table of contents (Table of Contents).
(hereinafter abbreviated as TOC) data is recorded for multiple cycles. This TOC data records information regarding the songs recorded on the compact disc (numbers indicating the order of the songs (hereinafter referred to as track numbers), the content of the songs, the playing time of the songs, etc.). However, the number of the lyrics in one song and the number of the movement in one song (hereinafter referred to as index numbers) are not recorded in the TOC data, and the program area, which is a data area related to the sound of the song, is not recorded in the TOC data. It is recorded in the form of a subcode (described on pages 117 to 122 of the Illustrated Compact Disc Reader, 1st edition, 1st printing, published by Ohmsha, November 25, 1981). Among these subcodes, a signal related to the location of information will be referred to as a location index signal.

Therefore, when selecting a song (hereinafter referred to as a search), a problem occurs when searching for an index number. That is, it is usually compact.
For disk players, turn on the player
Then, I read the lead-in area of the compact disc that is attached to it and read information about the songs on that disc. However, since no data is imported regarding the index number, the maximum index of the song to be searched is not known. Therefore, if you set an index number that you do not know, for example, if you want to hear the third lyrics of the second song, the song number will be the target song number (target track number), but the index number will be the target index number. It may not be the number. That is, when the set index number exceeds the maximum index number of the song to be searched, for example, when the second song mentioned above contains only the second lyrics. In such a case, the disk player has no target index, so there is no target to search for, and the search will continue forever. Therefore, in the technique disclosed in Japanese Patent Laid-Open No. 55-8695, it is not possible to reduce the difference between the target address and the current address. Furthermore, upon detection of the target address, it is not possible to stop the movement of the pickup that reads the information.

Furthermore, since the recorded performance time of each song recorded on a compact disc differs depending on the song, if the set index number as described above does not exist, the next track number will be detected after the set track number is detected. Since the index number is searched for the track number, if there are multiple indexes, it takes a very long time to find out that the index does not exist. This is a disadvantage for compact disk players, which are designed for easy random access.

(c) Problems to be solved by the invention In this invention, when the set index number is greater than the maximum index number of the song, the invention reads the maximum index number of the song and searches using this as the target index. Something,
In particular, this allows the maximum index number to be searched quickly.

(d) Means for solving the problem The present invention searches for a track number one larger than the set target track number, reads the maximum index number of the target track number, and calculates the target index of the set target track number. It is provided with means for comparing and determining the number and searching for a song based on the determination.

(E) Embodiment FIG. 1 is a block diagram of an index search device according to the present invention. In the drawing, reference numeral 1 denotes a pick-up that moves in the radial direction of the disk 2, and uses reflected light to accurately trace the objective lens 4, which converges the beam emitted from the laser element 3, along the track on the disk 2. After passing through a photoelectric conversion element 5 that converts it into an electric signal, the tracking error signal is applied to a servo circuit 6, and then applied to an objective lens drive element 8 via an adder 7 to apply servo.

Next, reference numeral 9 denotes a high frequency amplifier that amplifies the information reproduced from the disk 2, and the next stage digital signal demodulation circuit 10 demodulates the song data and index signal data, and the song data is transferred to the digital-to-analog converter 11.
The sound is emitted from the speaker 12 via the . Reference numeral 13 denotes an index signal detection circuit that detects track number (music number) data and index number data and supplies them to the control circuit 14 at the next stage.

The control circuit 14 includes a performance start key 15, a track number setting key 16, and an index number setting key 1.
7 etc., and after the track number or index number is set from the stop mode using the track number setting key 16 or the index number setting key 17, when the play start key 15 is operated, the set track number and index number are set. The pickup 1 and the tracking servo circuit 6 are controlled to search for the
This controls the displayed content.

In addition, 19 is a pickup drive circuit, and 20 is a feed motor of the pickup 1.

Next, FIG. 2 shows a control circuit 14 showing the main part of the present invention.
In the internal block diagram, the current track number (NT) data and current index number (NI) data detected by the index signal detection circuit 13 are temporarily stored in the respective first registers 21 and 22 according to the timing of the search circuit 30, which will be described later. It is stored as a signal (t1). 23 is a second register, which uses the data in the first register 22 as the timing signal (t2) of the search circuit 30.
Latch and memorize.

Next, 24 and 25 are track number setting keys 16
A track number setting circuit and an index number setting circuit are used to set track number and index number data using the index number setting key 17. 26 is an addition/subtraction circuit which adds +1 to the track number data set in the track number setting circuit 24, which is output from a search circuit 30 to be described later.
Alternatively, data of -1 is added or subtracted, and the content of the calculation is output to the first determination circuit 27. The first determination circuit 27 compares and determines the calculation contents of the addition/subtraction circuit 26 and the current track number (NT) data stored in the first register 21. A second determination circuit 28 compares and determines the settings of the index number setting circuit 25 and the current index number (NI) data stored in the first register 22. The first and second judgment circuits 27 and 28 described above have, for example, 2-bit output lines, and NT>OT, NT=OT, NT
Outputs the judgment bit of <OT(NI>OI, NI=OI, NI<OI). Further, 29 is a third judgment circuit,
The contents of the second register 23 and the contents of the index number setting circuit 25 are determined by a timing signal from a search circuit 30, which will be described later.

Reference numeral 30 denotes a search circuit composed of a micro-processing unit, which connects the first and second judgment circuits 2
According to the data (judgment bits) of 7 and 28, the pickup drive circuit 19, the tracking servo circuit 6, the gate circuits G1 and G2, the +1 and -1 addition and subtraction commands of the addition and subtraction circuit 26, and the first registers 21 and 2.
2. Controls reading and writing of data in the second register 23 and timing of reading and writing in the display shift register 31 that sets data on the display 18. The search operation of the search circuit 30 is started by operating the performance start key 15, and the program operates according to the detection bits of the first and second determination circuits 27 and 28 according to the flowchart shown in FIG.

In addition, the timing signals are (t1) shown in Fig. 2,
At (t2) and (t), the operation is performed at the timing shown in the flowchart of FIG. The operation of the present invention having such a configuration will be explained based on the circuit diagrams of FIGS. 1 and 2 as well as the flowchart of FIG. 3.

Now, in step A, when the track number setting key 16 is operated and the target track number OT=X is set, the data of X is set in the track number setting circuit 24, and the X data is set in the display shift register 30, and the display 18 displays the X data (step B).

Next, when the index number setting key 17 is operated, similar to the above-mentioned steps A and B,
The target index number OI=Y is set in the index number setting circuit 25, and the display 1
8 (Step C, Step D).

When the program proceeds to step E with the target track number OT=X and target index number OT=Y set, the start of the search operation is determined depending on whether or not the performance start key 15 is operated. First, as shown in step F, the parity of the difference OT-NT between the target track number (OT) and the current track number (NT) is checked. This parity can be determined by looking at the judgment bit of the first judgment circuit 27. The parity is then stored in the search circuit 30 and determines the search direction.

Next, in step G, the search circuit 30 gives an addition command to the addition/subtraction circuit 26, increments the set target track number (OT) by 1, and uses this as a comparative judgment input to the first judgment circuit 27.

Next, in step H, the search circuit 30 issues a command to the search means (pickup drive circuit 19, tracking servo circuit 6, adder 7) to reduce the difference between the absolute values |OT+1-NT|.

Such a search method is suggested in Japanese Patent Publication No. 59-16348, etc., and it moves the pick-up 1 when the difference between |OT-NT| is large, and tracks the objective lens 4 of the pick-up 1 when the difference is small. A search is performed based on a jump signal (TJ) and a gate signal (G). In step I, the information from the disk 2 that is sequentially read is the current track number (NT) of the position index signal detection circuit 13, and the data of the target track number + 1 is determined by the first judgment circuit 27 as shown in FIG. It is compared and determined. In step J, the current track number (NT) and the target track number OT+1 are compared and determined. If they do not match, the process moves to step H and the search is repeated. If they match, the process moves to step K. In step K, the search means (pickup drive circuit 19 and adder 7) are controlled so that the parity is opposite to the parity checked in step F. That is, if you want to search for the 7th track when pick-up 1 is on the 2nd track, OT-NT=7.
-2=5 and parity is positive. At this time, since the parity of pickup 1 is positive, it is controlled by search circuit 30 in a direction toward the outer periphery of disk 2.

Therefore, the search circuit 30 determines the target track number.
When the search for track number OT+1 is completed, pick-up 1 at that point is located on the outer periphery of the disk from the target track. By the way, the maximum index (MI) of the target track number (OT)
In order to search for , the parity may be reversed (that is, the search means may be moved slightly in the direction of the inner circumference of the disk).

This reverse search is performed in one track because the repetition frequency of the disk digital signal format is 7.35 KHz, and the position index signal with a repetition period of 136.1 μs is a set of 98 frames, that is, it becomes meaningful data in 13.3 m seconds. If it jumps, you can reliably read the maximum index (MI) of the target track number (OT).

In the next step L, the search circuit 30 issues a -1 subtraction command to the addition/subtraction circuit 26, and the contents of the addition/subtraction circuit 26 become the target track number (OT).
Then, in step M, it is determined whether the read point of pick-up 1 has entered the target track number (OT), and the program jumps to step K until it enters the target track number (OT). If it matches the target track number (OT), the process advances to step N, and the search circuit 30 searches the first register 2 in which the current index number (NI) that is currently being read is set.
2 is transferred to the second register 23 as the maximum index number (MI) at timing T2,
Latch. In the next step O, the second register 2
Maximum index number (MI) latched to 3
The third determination circuit 29 compares and determines the target index number (OI). If the maximum index number (MI) is smaller, the process moves to step P based on the judgment output, and the search circuit 30 resets the contents of the index number setting circuit 26, and
Applying a timing signal (t) to the gate circuit G3,
The maximum index number (MI) set in the second register 23 is set in the index number setting circuit 25. Furthermore, the search circuit 30 is a gate circuit G.
2 is also switched using the timing signal (t), the maximum index number (MI) is transferred to the display shift register 31, and it is latched using the latch signal (LT). Therefore, the display 18 displays the maximum index number (MI), so that the operator is informed that the displayed content has been changed and that the initially set index number (OI) does not exist in that song.

Next, proceed to step R, and set the maximum index number (MI) newly set in the index number setting circuit 25 in step P as the target index number (OI), and set the current index number (NI).
and search until there is no difference. When the difference disappears, the process proceeds to step S, the search means is released, and the disc player is put into a playing state (step T).

Incidentally, in step O, if the contents of the second register 23 are greater than or equal to the target index number OI, the process advances to step R and an index search is performed.

As is clear from the above explanation, in index search, first, the target track number +
Since I searched for track number 1,
Since the search means is located near the maximum index of the target track, the search becomes easy. This becomes clear when compared with a search method in which the target track number is searched and then the index is searched. That is, in the method of searching for the target track number, if the song does not have a set index number, comparisons are made starting from index number 1, and it takes time to detect the maximum index number, but the search method of the present invention According to the method, the track number +1 of the target track number is first searched, and then the index search of the target track number is performed, so the index search can be performed in advance in the vicinity of the maximum index number, so the maximum index number can be searched. It is easy to detect, the maximum index of the set target track number can be quickly notified to the operator, and the compact disc player, which is positioned as a luxury product, can be operated quickly.

(f) Effects of the invention As described above, according to the index search device of the invention, a track number one larger than a set target track number is first searched as a target track, and then an index search of the target track number is performed. Since the system is configured to do this, it is possible to quickly detect the maximum index number of the set target track number, especially when the set index number of the target track number is larger than the maximum index number.

Further, since the configuration is configured such that when the set index number is larger than the maximum index number of the target track number, the maximum index number is searched as the target index instead of the set index number, so that the problem of impossible search can be solved.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an index search apparatus according to the present invention, FIG. 2 is a block diagram of a control circuit showing the main parts of the present invention, and FIG. 3 is a flowchart explaining the operation of the present invention. 1...Pickup, 2...Disk, 13...
...Position index signal detection circuit, 14...Control circuit, 1
5... Performance start key, 16... Track number setting key, 17... Index number setting key, 18
...Display device, 21, 22...First register, 23
...Second register, 27...First judgment circuit, 2
8...Second determination circuit, 29...Search circuit.

Claims (1)

[Scope of utility model registration request] key input means for setting a target track number and index number; track number setting means and index number setting means for setting the target track number and target index number set by the key input means; a position index signal detection means for detecting a position index signal related to the position; a determination means for comparing and determining the current track number and current index number detected by the position index signal detection means with the target track number and target index number; a search means for searching for a song recorded on a disk based on a determination output of the determination means; and a search means for searching for a song recorded on a disc based on the determination output of the determination means; In an index search device comprising setting means for setting the maximum index number in the index number setting means instead of a number, at the initial stage of the playing operation, 1 is added to the track number setting means to set the target track number + 1. The track number is searched by the search means, and the target track number +1 by the judgment means.
After detecting the track number, the target track number is reset in the track number setting means, and this target track number is searched by the search means;
The index search device further comprises means for causing the position index signal detection means to detect the maximum index number of the target track after the determination means detects the target track number.