JPH07176057A - Disk reproducing device - Google Patents

Abstract

PURPOSE:To obtain the disk reproducing device capable of reading out TOC information in execution of an initial operation attending upon applying a power source without using an inner circumferential position detecting switch. CONSTITUTION:At the time of applying the power source, a focusing operation is performed without moving an optical pickup 5 but in its stopping position at this time, and whether a focusing point is obtained or not is decided. Then, when the focusing point is obtained, a TOC information area is searched by moving the optical pickup 5 in the inner circumferential direction in looking at positional information from the disk, and the TOC information is read out.

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, a disc reproducing apparatus of this type is
Prior to the start of reproduction, the disc is rotationally driven to perform an initial operation of reading TOC information (the number of songs, the start time of each song and its required time, the required time of all songs, etc.) stored in the disc. The example is shown in FIG.
Follow the instructions below.

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 the turntable 2, and 4 is arranged in parallel with the chassis 1. The pair of guide shafts 5 are slidably provided on the guide shaft 4, and are an optical pickup that moves in the radial direction of the disc 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 parts. 6
Is a slide motor that moves the optical pickup 5 by transmitting a driving force to the optical pickup 5 through a speed reduction mechanism. Reference numerals 7 and 8 are 8c mounted on the turntable 2.
The outline of each CD of m · 12 cm, 9 is an optical pickup 5
2 shows an inner peripheral position detection switch for detecting that the inner peripheral position has been moved to the inner peripheral position.

In the disc reproducing apparatus having the above structure,
When the power is turned on, the initial operation is executed according to the flowchart shown in FIG. That is, when the power is turned on, first, the slide motor 6 is driven to move the optical pickup 5 from the outer peripheral side of the disc in the inner peripheral direction at high speed until the inner peripheral position detecting switch 9 is turned on, and the inner peripheral position is detected. In response to the turning on of the switch 9, it is determined whether or not the in-focus point can be obtained by turning on the semiconductor laser and starting the operations of the focusing servo circuit and the timer.

If the in-focus point is not obtained within the time set by the timer, "no disk" is determined, and if the in-focus point is obtained, the disk is next discriminated within a predetermined time. It is determined whether or not the information from can be obtained. As a result of the judgment, if the information from the disc cannot be obtained, it is judged as "no disc (the disc is not in a normal state, for example, it is turned over)", and if the information is obtained, the "disc Yes (the disc is set in a normal state) ", and the TOC information in the lead-in area of the disc is read and stored in the memory. T
After the completion of reading the OC information, for example, if a desired song number is keyed in, the track number of the song is determined based on the song number and TOC information. This track number. Based on the above, the optical pickup 5 finds the beginning of the music and reproduces the music.

[0006]

By the way, in the conventional disc reproducing apparatus, in order to complete the initial operation upon power-on in a shorter time, the inner peripheral position detecting switch is provided to position the optical pickup 3 at the innermost peripheral position. It is configured to move all at once at high speed.
Since the width of the area for OC information is as narrow as about 2 mm, high accuracy is required for the mounting position of the inner circumference position detection switch, and in addition to the reliability of the switch and wiring material, this causes a problem. In addition, the mounting of the detection switch, the wiring associated therewith, further complicates the mechanism assembling work.

However, the present invention provides a disc reproducing apparatus which can eliminate the conventional inner peripheral position detecting switch and can perform the initial operation at the time of power-on at a speed at which there is no practical problem.

[0008]

SUMMARY OF THE INVENTION The present invention has been made for the purpose of solving the above-mentioned problems. In the disk reproducing apparatus according to claim 1, the disk is rotationally driven prior to the start of reproduction and is stored in this disk. In a disc reproducing apparatus for executing an initial operation of reading the TOC information stored therein by an optical pickup, disc detecting means for detecting the presence / absence of a disc based on the information obtained from the optical pickup, and position information obtained from the optical pickup. Search means for moving the optical pickup to a predetermined position on the disk and the disk detecting means for detecting the disk, and then the search means for moving the optical pickup to the head position of the TOC information on the disk. And an initial operation control means for reading the TOC information.

According to a second aspect of the present invention, there is provided the disc reproducing apparatus according to the first aspect, wherein the initial operation control means controls the optical pickup from the outer peripheral side of the disc when the disc is not detected by the disc detecting means. After a predetermined amount of movement in the inner peripheral direction, the disc detecting means performs the detecting operation again.

[0010]

In the above structure, when the power is turned on, the disc detecting means performs a focusing operation at that position without moving the optical pickup to obtain a focused point, and further, the disc is judged to be normal based on the information from the optical pickup. By confirming that
Determine "with disk". After that, the TOC information area is searched by moving the optical pickup based on the position information obtained from the disc, and the TOC information is read.

Therefore, since the optical pickup moves while searching, the time required for the initial operation is longer than in the conventional case, but there is almost no problem in actual use, and the inner peripheral position detection required in the conventional case is sufficient. The switch can be abolished.

Further, even when the 8 cm CD is set and the power is turned on with the optical pickup being outside the outer circumference of the 8 cm CD, the initial operation can be surely executed.

[0013]

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

FIG. 2 is a block diagram showing a control system of the disc 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. Driver circuit for driving the actuator of 5, 1
3 is a servo circuit for controlling the driver circuits 10 to 12 based on the information obtained from the optical pickup 5,
Reference numeral 14 is a signal processing circuit for processing a signal such as music information read by the optical pickup 5, and reference numeral 15 is a main control portion for controlling the above-mentioned respective portions. Thus, the main control section 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 disc reproducing apparatus of this embodiment, when the power is turned on, the initial operation is executed according to the flow chart shown in FIG. Now, when the power is turned on, the main control unit 15 turns on the semiconductor laser of the optical pickup 5, then 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 operation. The focusing operation at this time is to see whether or not the in-focus point can be obtained while lifting the objective lens upward by the actuator, and if the disc is set on the turntable 2 and the optical pickup 5 is at the opposite position. , A focused point is obtained.

When the in-focus point 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 in the inner peripheral direction along the guide shaft 4. See if you can get the focus while moving. The predetermined time set in the timer is set so that the optical pickup 5 can move from the outermost peripheral portion (that is, the position near the contour 8 of the 12 cm CD) to the contour 7 of the 8 cm CD.
Even if the 8 cm CD is set on the turntable 2 and the optical pickup 5 is located at the outermost peripheral portion, the in-focus point can be obtained by the time over. When the time is over without the in-focus point being obtained, it is determined that "no disk".

When the in-focus point is obtained, the main control section 15 sets the time again to the timer, and within the time, the disc information (absolute address of the disc, etc.) is sent from the optical pickup 5.
If the disc information is not obtained within the set time of the timer, it is judged that the disc is not in a normal state due to overturning etc. and "no disc"
Is determined. On the other hand, when the disc information is obtained, it is determined whether or not the TOC information has been read. If the TOC information has not been read, the optical pickup 5 obtains the position information from the disc and the absolute address. Search for "0:00", perform a few track jumps from that position, return to the lead-in area, and restart TO
C information is read.

As described above, in the disc reproducing apparatus of the present embodiment, the initial operation can be executed even if the conventional inner peripheral position detecting switch is abolished, and the size of the disc set on the turntable is large. For example, the initial operation can be surely executed regardless of whether it is 8 cm CD or 12 cm CD.

[0019]

As described above, according to the first aspect of the present invention, the TOC information can be surely read by executing the initial operation without using the inner circumferential position detection switch, and the position accuracy can be improved. It is possible to eliminate the inner circumference position detection switch that requires high accuracy and the wiring accompanying it, simplify the mechanism assembly work, and eliminate the possibility of problems due to the reliability of the switch and wiring. In addition, although the time required for the initial operation when the power is turned on is longer than in the conventional case, it does not pose any problem in practical use, and a very excellent disc reproducing apparatus can be provided.

Further, according to the second aspect of the present invention, the TOC information can be read by surely executing the initial operation upon power-on regardless of the size of the disk.

[Brief description of drawings]

FIG. 1 is a plan view showing a mechanism of a disc 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 of the reproducing apparatus.

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

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

[Explanation of symbols]

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

Claims (2)

[Claims] 1. A disc reproducing apparatus for performing an initial operation of rotating a disc prior to starting reproduction and reading TOC information stored in the disc by an optical pickup, based on information obtained from the optical pickup. Disc detection means for detecting the presence or absence of a disc, search means for moving the optical pickup to a predetermined position on the disc based on position information obtained from the optical pickup, and after detecting the disc by the disc detection means, A disc reproducing apparatus comprising an initial operation control unit for moving the optical pickup to a head position of the TOC information on the disc by the search unit to read the TOC information. 2. The initial operation control means, when the disk is not detected by the disk detecting means, moves the optical pickup from the outer peripheral side to the inner peripheral direction by a predetermined amount, and then performs the detecting operation again by the disk detecting means. The disc reproducing apparatus according to claim 1, wherein the disc reproducing apparatus is performed.