JP2905679B2 - Disc playback device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc reproducing apparatus for reproducing a disc having TOC (Table Of Content) information, such as a disc called a compact disc (CD) or a mini disc (MD). is there.

[0002]

2. Description of the Related Art Generally, this kind of disc reproducing apparatus is
Prior to the start of reproduction, an initial operation of rotating the disk and reading the TOC information (number of songs, start time of each song and its required time, required time of all the songs, etc.) stored in the disk is executed. FIG. 4 shows an example of this.
It will be described according to.

In FIG. 4, 1 is a chassis, 2 is a turntable located on the chassis 1, 3 is a spindle motor below the chassis 1 for rotating and driving the turntable 2, and 4 is disposed parallel to the chassis 1. The pair of guide shafts 5 and 5 are slidably provided on the guide shaft 4 and are optical pickups that move in the radial direction of a disk to be described later by the sliding operation. The optical pickup is a semiconductor laser, an objective lens, It includes an actuator for the objective lens, a light receiving element, and other optical components. 6
Is a slide motor for moving the optical pickup 5 by transmitting a driving force to the optical pickup 5 via a speed reduction mechanism, and 7 and 8 are 8c mounted on the turntable 2.
Outline of each CD of m · 12cm, 9 is an optical pickup 5
5 shows an inner peripheral position detection switch that detects that is moved to the inner peripheral position.

[0004] In the disk reproducing apparatus having the above configuration,
When the power is turned on, an initial operation is performed according to the flowchart shown in FIG. That is, when the power is turned on, first, the slide motor 6 is driven, and the optical pickup 5 is moved at high speed from the outer peripheral side of the disk toward the inner peripheral direction until the inner peripheral position detection switch 9 is turned on. In response to the ON of the switch 9, the semiconductor laser is turned on and the operations of the focusing servo circuit and the timer are started to determine whether or not a focus can be obtained.

If the in-focus point is not obtained within the time set by the timer, it is determined that there is no disc, and if the in-focus point is obtained, the disc is next detected within a predetermined time. It is determined whether or not the information from is obtained. As a result of the determination, if information from the disk cannot be obtained, it is determined that "there is no disk (the disk is not in a normal state, for example, it is turned over)", and if the information is obtained, the "disk Yes (the disc is set in a normal state) ", reads the TOC information in the lead-in area of the disc, and stores it in the memory. T
After the reading of the OC information is completed, for example, if a desired music number is inputted by a key, the track number of the music is determined based on the music number and the TOC information. For the track No. Based on this, the head of the music is retrieved by the optical pickup 5 and the music is reproduced.

[0006]

By the way, in the conventional disk reproducing apparatus, an inner peripheral position detecting switch is provided to move the optical pickup 3 to the innermost peripheral position in order to perform the initial operation upon turning on the power in a shorter time. Up to high speed at a stretch,
Since the width of the OC information area is as narrow as about 2 mm, high accuracy is required for the mounting position of the inner peripheral position detection switch, and in addition to the reliability of the switch and the wiring material, a problem may occur. In addition, the mounting of the detection switch and the accompanying wiring and the like also cause a problem that the assembly work of the mechanism becomes more complicated.

However, the present invention provides a disk reproducing apparatus which eliminates the conventional inner peripheral position detecting switch and can execute an initial operation upon power-on at a speed which does not cause a practical problem.

[0008]

SUMMARY OF THE INVENTION The present invention has been made for the purpose of solving the above-mentioned problems, and comprises a plurality of disks having different diameters.
The disk can be reproduced, and the disk is driven to rotate before the reproduction starts , and the T stored in the disk is
In a disc reproducing apparatus for performing an initial operation of reading OC information by an optical pickup, a disc detecting means for detecting the presence or absence of a disc based on information obtained from the optical pickup; Search means for moving the optical pickup to a predetermined position on the disc, and initial operation
At the start of the measurement, the clocking of the predetermined time starts and
During the measurement of the predetermined time of
When the disc is not detected,
After moving a predetermined amount in the inner circumference direction from the outer circumference side of the disc
The detection operation is performed again by the disk detection means.
Upon detecting the disc by the disc detecting means during measurement of the predetermined time, by the search means to move the optical pickup to the start position of the TOC information on the disc to read the TOC information, further, the place
Even if the fixed time has elapsed, the disk detection means
When the click is not detected, while and a initial operation control means it determined that there is no disk, the above initial operation control means,
The above-mentioned predetermined time is taken when the optical pickup
Time to move from the outermost circumference to the contour of the small-diameter disk
It is set to.

[0009]

[0010]

In the above configuration, an initial operation is started.
And the disk detecting means moves the optical pickup
The focusing operation at that position without
Gain focus and based on information from that optical pickup
Check that the disk is in a normal state, and
The operation control means starts measuring a predetermined time, and the predetermined time
The disk is detected by the disk detection means during
When the disc is not ejected, move the optical pickup
After moving a predetermined amount in the inner circumferential direction,
The detection operation is performed by the steps, and even if the predetermined time
If the disk is not detected by the disk
While it is determined that there is no disk,
The disk is detected by the disk detection means
The optical pickup by TOC on the disc
Move to the beginning of the information and read the TOC information
Let

Therefore, although the time required for the initial operation is longer than that of the conventional optical pickup because the optical pickup moves while searching, there is almost no problem in actual use. Switches can be eliminated.

In addition, the initial operation control means is provided at the predetermined time.
Optical pickup between the outermost part of the large-diameter disc
Set the time to move within the contour of the small-diameter disc
The initial operation is performed with the small-diameter disc set and the optical pickup positioned outside the outer circumference of the small-diameter disc.
Even if started , use position detection switch etc.
Therefore , the initial operation can be reliably performed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention shown in FIGS. 1 to 3 will be described below in detail. FIG. 1 is a plan view showing a mechanism of a disk reproducing apparatus according to an embodiment of the present invention.
FIG. 1 is different from FIG. 4 only in the presence or absence of an inner peripheral position detection switch, and all other points are the same, so that the description here is omitted.

FIG. 2 is a block diagram showing a control system of the disk reproducing apparatus. 10 is a driver circuit for driving the spindle motor 3, 11 is a driver circuit for driving the slide motor 6, and 12 is an optical pickup. A driver circuit for driving the actuators of No. 5;
3 is a servo circuit that controls each of the driver circuits 10 to 12 based on information obtained from the optical pickup 5;
Reference numeral 14 denotes a signal processing circuit that processes signals such as music information read by the optical pickup 5, and 15 denotes a main control unit that controls the above-described units. Thus, the main control unit 15 constitutes the disk detection means, the search means, the initial operation control means and the like in the present invention together with the servo circuit 13 and the like.

In the disk reproducing apparatus of the present embodiment, an initial operation is executed according to a flowchart shown in FIG. 3 when the power is turned on. Now, when the power is turned on, the main control unit 15 turns on the semiconductor laser of the optical pickup 5, starts the focusing operation of the optical pickup 5 via the servo circuit 13, and then sets a predetermined time in the timer to set the timer. Start the operation. The focusing operation at this time is to check whether or not a focal point can be obtained while lifting the objective lens upward by the actuator. If the disc is set on the turntable 2 and the optical pickup 5 is located at a position facing the optical pickup 5, , Focus is obtained.

When the focus cannot be obtained by the first focusing operation, the main controller 15 drives the slide motor 6 via the servo circuit 13 to move the optical pickup 5 along the guide shaft 4 in the inner circumferential direction. See if you can get the focus while moving. The predetermined time set in the timer is set to a time during which the optical pickup 5 can move from the outermost peripheral portion (that is, a position near the contour 8 of the 12 cm CD) into the contour 7 of the 8 cm CD.
Even if an 8 cm CD is set on the turntable 2 and the optical pickup 5 is located at the outermost peripheral portion, a focal point can be obtained before the time is over. If the time is over without obtaining the in-focus point, it is determined that there is no disc.

When the in-focus point is obtained, the main control section 15 sets a time on the timer again, and within the time, the disk information (such as the absolute address of the disk) from the optical pickup 5 is set.
Is determined, and if the disc information is not obtained within the set time of the timer, it is determined that the disc is not in a normal state due to flipping over and the like, "no disc"
Is determined. On the other hand, when the disc information is obtained, it is determined whether the reading of the TOC information is completed. When the reading is not completed, the absolute address is obtained while obtaining the position information from the disc by the optical pickup 5. Search for "0:00", jump a few tracks from that position, return to the lead-in area and go back to TO
The C information is read.

As described above, in the disk reproducing apparatus of this embodiment, the initial operation can be performed even if the conventional inner peripheral position detection switch is abolished, and the size of the disk set on the turntable can be improved. For example, the initial operation can be reliably executed regardless of the 8 cm CD or the 12 cm CD.

[0019]

As described above, according to the present invention, the initial operation can be performed without using the inner peripheral position detecting switch or the like.
The TOC information can be reliably read, and the inner peripheral position detection switch, which requires high accuracy in position accuracy, and the associated wiring, etc., can be eliminated, simplifying the mechanism assembly work and simplifying the switch and wiring. This eliminates the risk of problems due to reliability. In addition, the time required for the initial operation when the power is turned on is longer than before, but it does not cause any problem in practical use. An apparatus can be provided.

Further, according to the present invention, the TOC information can be read by reliably executing the initial operation regardless of the size of the disk , and the initial operation can be reliably performed.
To eliminate the need for position detection switches, etc.
Can be.

[Brief description of the drawings]

FIG. 1 is a plan view showing a mechanism of a disk reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a control system of the reproducing apparatus.

FIG. 3 is a flowchart of an initial operation in the reproducing apparatus.

FIG. 4 is a plan view showing a mechanism of a conventional disk reproducing apparatus.

FIG. 5 is a flowchart of an initial operation in the reproducing apparatus.

[Explanation of symbols]

 2 Turntable 3 Spindle motor 5 Optical pickup 6 Slide motor 13 Servo circuit 15 Main control unit

Claims (1)

(57) [Claims] 1. Reproduction of a plurality of discs having different diameters is possible.
And a disk reproducing apparatus that performs an initial operation of rotating a disk prior to the start of reproduction and reading TOC information stored in the disk by an optical pickup, based on information obtained from the optical pickup. A disk detecting means for detecting the presence or absence of a disk, a search means for moving the optical pickup to a predetermined position on the disk based on the position information obtained from the optical pickup, and starting timing of a predetermined time at the start of the initial operation Then
In both cases, the disc is detected during the measurement of the predetermined time.
When the disc is not detected by the means, the optical pick
Up by a predetermined amount from the outer circumference to the inner circumference.
Detection operation is performed again by the disk detection means
It was also the time of detecting the disc by the disc detecting means during measurement of the predetermined time, allowed by the search means to move the optical pickup to the start position of the TOC information on the disc read the TOC information, further
Even if the predetermined time has passed,
When more disk is not detected, while and a <br/> Ru initial operation control means to determine that no disc, the initial operation control means, the optical pitch of the predetermined time
Backup from outermost part of large-diameter disk to small-diameter disk
A disc reproducing apparatus characterized in that the time is set such that the disc can be moved within the outline of the disc.