JPH0828036B2 - Compact disk player - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compact disc player capable of quickly taking out data on a compact disc.

2. Description of the Related Art In recent years, it has been noted that compact disc players have good operability such as random access.

An example of a conventional compact disc player will be described below with reference to the drawings.

FIG. 3 is a block diagram of a conventional compact disc player, 21 is a signal detection unit for extracting an RF signal from the disc, 22 is a spindle motor drive unit for rotating the disc, and 23 is a signal obtained from the signal detection unit 21. A spindle servo unit that sends a control signal to the spindle motor drive unit 22 in synchronization with the reference signal.

The operation of the compact disc player configured as described above will be described below.

When the optical pickup enters within one round before the requested data block, the RF signal is taken out from the disk by the signal detecting section 21 and the spindle motor driving section is synchronized with the reference signal by the spindle servo section 23.
A control signal is sent to 22 and the system waits until the requested data block comes out in a state where the data on the disk can be read at all times.

Problems to be Solved by the Invention However, in the above configuration, if the optical pickup enters within one round before the requested data block, it always waits in a state in which the data can be read until the data block can be read. In this case, there is a problem in that the disk has to wait for one rotation.

In view of the above problems, the present invention provides a compact disc player that shortens the rotation waiting time when reading data and speeds up reading of a requested data block.

Means for Solving the Problems In order to solve the above problems, a compact disc player according to the present invention includes an information reading unit for reading time information recorded on a compact disc and an optical pickup position for detecting the position of an optical pickup. A detection unit, a linear velocity calculation unit that calculates the recording linear velocity of the disc based on the time information from the information reading unit and the optical pickup position information from the optical pickup position detection unit, and a spindle motor drive that rotates the disc. Section, a rotation angle detection section for knowing the rotation angle of the spindle motor, the number of data blocks per one rotation of the disk is calculated from the linear velocity information and the optical pickup position information, and from the current position to the target data block based on the time information. The number of data blocks of the The rotation angle of the spindle motor is accelerated and decelerated so that the rotation angle to the target data block can be calculated from the number of locks and the number of data blocks up to the target data block to quickly reach the target data block and read the data normally. The control unit supplies a signal for steady control to the spindle motor drive unit in accordance with the rotation angle information from the rotation angle detection unit.

Operation According to the present invention, when the optical pickup enters within one round before the data block for which the optical pickup is required by the above-described configuration, the control section receives information about how many blocks of data by the information from the optical pickup position detecting section and the linear velocity calculating section. The spindle motor is driven by calculating the number of blocks up to the requested data block based on the information from the information reading unit and calculating how many more rotations to reach the requested data block by the control unit. By issuing a control signal of the motor rotation speed to the unit, it is possible to read the requested data block earlier.

Embodiment A compact disc player according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a block diagram of a compact disc player in an embodiment of the present invention. In FIG.
11 is an information reading unit for reading time information recorded on the compact disc, 12 is an optical pickup position detecting unit for detecting the position of the optical pickup, and 13 is an information reading unit 11.
A linear velocity calculating unit for calculating the recording linear velocity of the disc based on the information from the optical pickup position detecting unit 12
Is a spindle motor drive unit for rotating the disc, 15 is a rotation angle detection unit for knowing the rotation angle of the spindle motor, 16 is an information reading unit 11, an optical pickup position detection unit 12, a linear velocity calculation unit 13, and a rotation angle detection unit 15. It is a control unit that sends a control signal to the spindle motor drive unit 14 according to information from each unit.

The operation of the compact disc player of the present embodiment constructed as above will be described with reference to the flowcharts of FIGS. 1 and 2.

When the optical pickup enters within one round before the requested data block, the linear velocity calculation unit 13 is preliminarily obtained by the time information from the information reading unit 11 and the optical pickup position information from the optical pickup position detection unit 12 as in step 1. The number of data blocks per revolution of the compact disc is calculated from the linear velocity information of the disc obtained in step 1 and the optical pickup position information from the optical pickup position detection part 12, and the time obtained from the information reading part 11 is calculated. The number of data blocks existing from the current position of the optical pickup to the target data block is obtained from the information, and the target data block is calculated using the number of blocks and the number of data blocks per one rotation of the compact disc calculated. The number of rotations to be calculated is calculated. At the same time, as in step 2, the control unit 16 issues a control signal to the spindle motor drive unit 14 so as to maximize the speed of the spindle motor. Next, at step 3, the shift control unit 16 sends a control signal to accelerate the spindle motor to the maximum until it detects that the rotation angle to the data block requested by the information from the rotation angle detection unit 15 is 1/2. 1/2 of the rotation angle up to the requested data block
When it is detected that the spindle motor has rotated, a control signal is output to the spindle motor drive unit 14 to decelerate the spindle motor to the maximum as in step 4. Then, if the process moves to step 5 and the requested data block is rotated, a control signal is output to the spindle motor drive unit 15 to make steady rotation as in step 6.

As described above, according to the present embodiment, the optical pickup position detection unit 12 and the linear velocity calculation unit 13 are provided to know the number of data blocks for one rotation of the disc in which the main pickup is present, and the optical information is read by the time information from the information reading unit 11. The rotation angle to the target data block is calculated by obtaining the number of data blocks from the current position of the pickup to the target data block, and the spindle motor is accelerated by knowing the rotation angle of the disc from the rotation angle detection unit 15. It is possible to reduce the speed and reduce the rotation waiting time until the requested data block is fetched.

As described above, according to the present invention, the information reading unit for reading the time information recorded on the compact disc, the optical pickup position detecting unit for detecting the position of the optical pickup, the information from the information reading unit and the optical pickup position. Linear velocity calculation unit that calculates the recording linear velocity of the disc based on information from the detection unit, spindle motor drive unit that rotates the disc, rotation angle detection unit that knows the rotation angle of the spindle motor, information reading unit, optical pickup position By providing a control unit that sends a control signal to the spindle motor drive unit based on information from the detection unit, linear velocity calculation unit, and rotation angle detection unit, the rotation waiting time until the requested data block is extracted can be shortened. can do.

[Brief description of drawings]

FIG. 1 is a block diagram of a compact disc player according to an embodiment of the present invention, FIG. 2 is a flow chart of operations in an embodiment of the present invention, and FIG. 3 is a diagram of a conventional compact disc player. 11 ... Information reading unit, 12 ... Optical pickup position detection unit, 13 ... Linear velocity calculation unit, 14 ... Spindle motor drive unit, 15 ... Rotation angle detection unit, 16 ... Control unit.

Claims (1)

[Claims] 1. An information reading section for reading time information recorded on a compact disc, an optical pickup position detecting section for detecting the position of an optical pickup, time information from the information reading section and the optical pickup position detecting section. A linear velocity calculation unit that calculates the recording linear velocity of the compact disc based on the optical pickup position information from the optical disc, a spindle motor drive unit that rotates the compact disc, and a rotation angle detection unit that knows the rotation angle of the spindle motor, The disc 1 based on the recording linear velocity information of the compact disc obtained by the linear velocity calculation unit and the optical pickup position information from the optical pickup position detection unit.
The number of data blocks per rotation is calculated, and the number of data blocks from the current position to the target data block is calculated according to the time information from the information reading unit. The calculated number of data blocks per rotation of the disk and the calculated target data. Control for accelerating / decelerating and steady controlling the rotation speed of the spindle motor so that the rotation angle to the target data block is calculated from the number of data blocks up to the block and the target data block is quickly reached and data can be read normally. A compact disc player, comprising: a control unit that supplies a signal to the spindle motor drive unit in accordance with the rotation angle information from the rotation angle detection unit.