JPH0719454B2 - Optical disc player search method - Google Patents

Description

The present invention relates to a search method for an optical disc player used for music reproduction and the like.

"Prior Art" FIG. 2 is a block diagram showing a configuration example of a conventional compact disc player. In this figure, 1 is a compact disc (CD), and the TOC (Table Of
Contents) information is recorded. Reference numeral 2 is a spindle motor for rotationally driving the CD 1, 3 is an optical pickup for reading digital information recorded by pits on the signal recording surface of the CD 1 by using a laser beam, and 4 is a feed motor for moving the optical pickup 3.

Further, 5 is an RF amplifier that generates and outputs a focus error signal and a tracking error signal from the read signal output from the optical pickup 3, and amplifies and outputs this read signal, and 6 is a signal output from the RF amplifier A data processor that performs processing such as demodulation of signals, correction and correction of code errors, 7 is a DA converter that converts a digital signal output from the data processor 6 into an analog audio signal, and 8 is an amplification to this audio signal and sound quality control, etc. The output signal of the audio circuit 8 is output to an external speaker or the like via the audio output terminal 9. 10 is a system controller, which is a CPU (central processing unit) and this C
ROM 11 that stores programs used in PU
And a RAM 12 for data storage and an I / O (input / output) port. Reference numeral 13 denotes a focus adjustment control (focus servo) and a tracking adjustment control (tracking servo) of the optical pickup 3 using the focus error signal and the tracking error signal output from the RF amplifier 5 under the control of the system controller 10.
This is a servo processor that performs feed adjustment control of the feed motor 4 (feed servo) and constant linear velocity control of the spindle motor 2 (spindle servo).

Here, the linear velocity is vo (m / s) and the track pitch is p.
(Μm), the innermost radius of the program area is ro (mm),
The radius of the track position corresponding to the currently playing song is r
(Mm), the absolute time of the song currently being played is t (sec)
Then, there is a relationship shown in the following equation between them.

{Π (r ² −r ₀ ² )} / p = v ₀ t (1) Substituting v ₀ = 1.3 m / s, p = 1.6 μm, and r ₀ = 25 mm into this equation (1) yields r ² = 625 + 0.66t (2)

If the radii of track positions at arbitrary two points on CD1 are r ₁ (mm) and r ₂ (mm), the number N of tracks existing between these two points is expressed by the following equation.

N = (r ₁ −r ₂ ) / p (3) Therefore, from equations (2) and (3), any 2 on CD1 can be obtained.
The number of tracks existing between these two points can be obtained from the absolute time corresponding to the track positions of the points. And
The calculation table of these two equations is stored in advance in the ROM 11 in the system controller 10.

On the other hand, when the CD 1 is set in the compact disc player and the power is turned on, the TOC information is read from the CD 1 by the optical pickup 3 and stored in the RAM 12 in the system controller 10.

As a result of the above, a desired music piece (the track position on CD1 corresponding to the start portion of this music piece is designated as B point) is searched from the track position A point corresponding to the currently reproduced music piece shown in FIG. The CPU in the system controller 10 is
First, the number of tracks existing between the track position A point and the track position B point on CD1 is calculated using the above-mentioned calculation table.

Next, the signal read by the optical pickup 3 is processed to count the number of tracks from the track position A on the CD 1 and the optical pickup 3 is moved to the vicinity of the track position B by the feed motor 4 (step). .

Then, the tracking actuator of the optical pickup 3 is driven to perform 125 track jumps several times to pass the track position B (step).

Then, this time, the tracking actuator of the optical pickup 3 is driven in the reverse direction, and 25 track jumps are performed several times to pass the toke position B point (step).

Further, the tracking actuator of the optical pickup 3 is driven in the opposite direction again, and a 5-track jump is performed several times to pass the track position B (step).

Finally, the tracking actuator of the optical pickup 3 is driven in the opposite direction again to perform one track jump several times to reach the track position B (step).

[Problems to be Solved by the Invention] By the way, in the above-described conventional optical disc player search method, vibrations from the outside or CDs from the outside while performing a small track jump such as a one-track jump.
If the optical pickup 3 moves to a track position away from the track position B point corresponding to the desired song due to scratches on the track 1 or the like, it is necessary to start again from step or step, and the track position B point. There was a drawback that it took time to reach.

The present invention has been made in view of the above-mentioned circumstances, and provides a search method for an optical disk player, which can perform a search in a short time even if there is external vibration during the search or scratches on the CD. It is intended to be provided.

"Means for Solving the Problem" The present invention relates to a search method of an optical disc player for sequentially shifting from a jump having a large number of tracks to a jump having a small number of tracks to search for a desired track position. If the jump does not pass the target track position even if the jump is repeated a predetermined number of times, the jump is repeated one rank higher than the jump and the search is continued.

[Operation] According to the present invention, if the target track position is not passed even if one track jump is repeated a predetermined number of times,
Since the search is continued by returning to a jump having a track number one rank higher than the current track jump, a desired track position can be quickly searched.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings. First, the structure of the compact disc player is the same as that of the conventional technique described above, and the types of track jumps in the search method are 125 track jumps and 25 track jumps.
There are four types of jumps, 5 jumps and 1 jump. In addition, when the above-mentioned track jump operations were performed 10 times in succession, vibration was applied from the outside or CD
Judging that a disturbance such as a scratch on the top has occurred,
Set to return to a track jump that is one rank higher than each track jump. The above contents are stored in advance in the ROM 11 in the system controller 1.

In such a configuration, in order to search the position B of the track corresponding to the start portion of the desired music from the position A of the track corresponding to the currently reproduced music shown in FIG. The CPU first calculates the number of tracks existing between the track position A point and the track position B point on the CD 1 using the above calculation table.

Next, while the signal read by the optical pickup 3 is processed to count the number of tracks from the track position A on the CD 1, the optical pickup 3 is moved to the vicinity of the track position B by the feed motor 4.
(Step).

Then, the tracking actuator of the optical pickup 3 is driven to perform 125 track jumps several times to pass the track position B (step).

Then, this time, the tracking actuator of the optical pickup 3 is driven in the reverse direction, and 25 track jumps are performed several times to pass the track position B (step).

Further, the tracking actuator of the optical pickup 3 is driven in the opposite direction again, and a 5-track jump is performed several times to try to reach the track position B (step). At this time, it is assumed that the 5 tracks are performed 10 times in succession. As a result, the CPU in the system controller 10 determines that external vibration such as external vibration has occurred, or that damage such as scratches on the CD 1 has occurred and returns to step.

In the step, the tracking actuator of the optical pickup 3 is driven in the opposite direction to the previous 25-track jump to perform 25-track jump several times to pass the track position B.

Further, the tracking actuator of the optical pickup 3 is driven in the opposite direction again, and a 5-track jump is performed several times to pass the track position B (step).

Finally, the tracking actuator of the optical pickup 3 is driven in the opposite direction again, and one track jump is performed several times to reach the track position B. (Step).

In the above description, each track jump is stepped 5 times, and if each track jump fails 10 times in succession, it is regarded as an error. However, each track jump is stepped n times and each track jump is It may be an error if the jumps fail 2n times in a row.

Also, in the above description, in the search step,
Although the feed motor 4 is used, 125 track jumps may be performed directly.

Further, this method can be used for a returning process when the tracking servo or the focus servo is deviated in addition to the beginning of the music by the search.

Although the above-described embodiment is a compact disc player for normal music reproduction, the present invention is not limited to the CD-RO.
M, CD-V (compact disc video), CD-I
It can also be applied to playback devices such as (compact disc / interlaced media) and LD (laser disc).

[Advantages of the Invention] As described above, according to the present invention, during search,
Even if there is external vibration or scratches on the CD, it is possible to search in a short time.

[Brief description of drawings]

FIG. 1 shows a conventional example and a search method for a compact disc player according to an embodiment of the present invention, and FIG. 2 shows a compact disc player to which the search method for a compact disc player according to the conventional example and one embodiment of the present invention is applied. 3 is a block diagram showing a configuration example of FIG. 1 ... Compact disk, 10 ... System controller.

Claims (1)

[Claims] 1. A search method for an optical disk player, wherein a jump from a large number of tracks to a jump from a small number of tracks is sequentially performed to search for a desired track position, and any one of the plurality of jumps is repeated a predetermined number of times. Even if the target track position is not passed, a search method for an optical disk player is characterized in that the search is continued by returning to a jump having a track number one rank higher than the jump.