JPH0722760Y2 - Recording medium selection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention relates to a recording medium selection device, and more specifically, it stores a plurality of compact disks in a magazine.
This magazine is moved up and down to select a desired compact disk, and the selected compact disk is loaded into a playback mechanism such as an optical pickup or a motor for driving the disk to perform playback. The present invention relates to a recording medium selection device that is preferably implemented in a compact disc playback device that can be changed.

2. Description of the Related Art In a compact disk reproducing apparatus having the above-described configuration, in a typical prior art, for example, when a pulse motor is used, the motor is controlled at a constant duty depending on the energization time, and a desired value is obtained. The disk to be selected and the loading operation were being performed. When a normal DC motor is used, the same operation is performed by adjusting the energization time.

Problems to be Solved by the Invention In the above-described prior art, when the power supply voltage fluctuates,
The amount of rotation of the motor changed, and malfunctions such as incorrect selection of compact disks and improper loading occurred.

It is an object of the present invention to provide a recording medium selection device having improved reliability by preventing malfunctions such as a recording medium selection error or a defective loading due to the fluctuation even when the power supply voltage fluctuates. .

Means for Solving the Problems The present invention provides a storage means for storing a plurality of recording media, a first motor for displacing the storage storage means, and a device for selectively loading the recording media for reproduction or recording. A recording medium reproducing apparatus including a second motor that is in a ready state, a power source, and a control unit that controls the first and second motors by the power from the power source. Voltage control means for detecting a voltage, wherein the control means, in response to the output of the voltage detection means, extends the period for energizing the first and second motors when the power supply voltage becomes low. A device for selecting a characteristic recording medium.

Operation According to the present invention, the storage means capable of storing a plurality of recording media is displacement driven by the first motor.
The second motor selectively takes out a desired recording medium from the displaced storage means and loads it into a state in which reproduction or recording can be performed. On the other hand, electric power from a power supply is applied to these first and second motors through a control means, and the power supply voltage is detected by a voltage detection means, and the control means uses this voltage. The first and second motors are controlled in response to the output of the detecting means.

Therefore, when the power supply voltage drops, the amount of power supplied to these motors is increased by lengthening the period for energizing the first and second motors according to the degree of the drop. Is the same as in normal times, which allows you to avoid malfunctions such as incorrect recording medium selection and improper loading.
A reliable operation can be performed.

Embodiment FIG. 1 is a block diagram showing a simplified configuration of a compact disc reproducing apparatus 1 according to an embodiment of the present invention. The compact disc reproducing apparatus 1 includes a compact disc 3 which is a recording medium in a storage means 2 called a magazine.
Can be stacked and stored, the compact disks 3 are selectively taken out, and the recorded content is reproduced by the single reproducing mechanism 4.

The storage means 2 is driven up and down by the lifting motor M1 in the stacking direction of the compact disks 3, that is, in the arrow A1 direction. In the storage means 2 thus moved up and down, the compact disc 3a at the pull-out position P1 is pulled out by the loading motor M2 and loaded into the reproducing mechanism 4. The loading motor M2 also raises and lowers the reproduction mechanism 4. A pulse motor is used for the motors M1 and M2.

The reproducing mechanism 4 includes a disk motor M3 that rotationally drives the loaded compact disk 3a, and the disk motor M3.
A turntable 5 attached to the output shaft of the M3, a clamp mechanism 6 for pressing the compact disk 3a together with the turntable 5, and an optical pickup 7 for reading the recorded contents recorded on the compact disk 3 are included. Composed. The output of the optical pickup 7 is subjected to digital / analog conversion or the like by the sonication circuit 8 and is output to the output shaft 9 as an acoustic signal.

The selecting operation of the compact disk 3 is performed by the control unit 11 in response to the input from the operation unit 10. Control unit
11 is a drive circuit U corresponding to each of the motors M1 and M2.
1 and U2 are provided, and these drive circuits U1 and U2 perform pulse width modulation of the power from the power supply circuit 12 according to the control signal from the processing circuit 13 to perform so-called duty control, and the motor Give to M1 and M2 respectively. The power supply voltage of the power supply circuit 12 is supplied to the analog / digital converter 14, and the analog / digital converter 14 supplies an output corresponding to the power supply voltage to the processing circuit 13, whereby the processing circuit 13 is supplied.
Performs the duty control as described above. The processing circuit 13 and the analog / digital converter 14 constitute voltage detecting means, and are configured in the same microcomputer 15.

In the duty control as described above, depending on whether the storage means 2 and the reproducing mechanism 4 are moving up or down, the processing circuit 13 is set to the power supply voltage V1 as shown in Table 1. A map representing the corresponding duty D is stored, and control based on this map is performed.

Compact disc playback device 1 configured as described above
When the power supply voltage V1 is at the normal value V1a, the drive circuits U1 and U2 are supplied with electric power having the pulse width W1 and the pulse interval W2, as shown in FIG. That is, the duty D, which is the modulation factor of the pulse width modulation at this time, is It is represented by.

When the power supply voltage from the power supply circuit 12 drops to V1b, the processing circuit 13 is driven with the pulse width W1b so that the electric energy per unit cycle W becomes equal, as shown in FIG. 2 (2). I do. That is, V1a.W1.apprxeq.V1b.W1b (2) The motors M1 and M2 are thus duty controlled.

FIG. 3 is a flow chart for explaining a specific operation of the processing circuit 13. In the operation of FIG. 3,
Based on the conversion result of the analog / digital converter 14, the power supply voltage is divided into Va to Vn in advance, and the duty cycle determined in advance for each stage is
Control from Da to Dn.

That is, it is determined in step s1 whether the power supply voltage V1 is equal to or higher than the voltage Va, and if so, the process proceeds to step s2 and the control is performed with the duty Da (%). Step s2
When the power supply voltage V1 is less than the voltage Va, the process proceeds to step s3, and it is determined whether it is the voltage Vb or more. If yes, the process proceeds to step s4 and the duty Db is used for control. In step s3, the power supply voltage V1 is the voltage Vb
If it is less than the value, the process proceeds to step s5, and it is judged whether it is the voltage Vc or more.
Then, the control is performed by the duty Dc. Thereafter, the same operation is repeated, and it is determined in step s7 whether the power supply voltage V1 is equal to or higher than the voltage Vn, and if so, the control is performed by the duty Dn in step s8. Step
When the power supply voltage V1 is lower than the voltage Vn at s2, s4, s8 and s7, the operation is returned to step s1 and the same operation is repeated.

By thus driving the motors M1 and M2 with the duty D corresponding to the fluctuation of the power supply voltage V1, the storage means 2
Is accurately moved up and down so that a desired compact disk, for example, 3a, is located at the insertion / ejection position P1, thereby preventing erroneous selection of the compact disk 3.
In addition, defective loading of the selected compact disk 3a is prevented, and reliable operation can be performed. Furthermore, since such control is performed by the microcomputer 15, it can be performed at low cost and high speed without newly providing a special configuration.

In the above embodiment, the motors M1 and M2 are pulse motors,
Although the duty D is changed in response to the decrease in the power supply voltage V1, another embodiment of the present invention is that the motors M1 and M2 are direct current motors, and the normal voltage is set in accordance with the change in the power supply voltage V1. The time may be changed. Also, the power supply voltage V
The control for the decrease of 1 may be performed. Furthermore, the present invention is not limited to the compact disc reproducing device 1 as described above, but may be used in a reproducing device for a magnetic tape cassette capable of auto-changing.

As described above, according to the present invention, the first motor for displacing the storage means capable of storing a plurality of recording media and the desired recording medium are selectively taken out from the storage means. The second motor, which is mounted in a state in which reproduction or recording can be performed, is such that when the power supply voltage drops, the period in which the power is energized is lengthened according to the degree of the drop. The amount of power supplied to these motors is the same as in normal times, which allows reliable operation without causing malfunctions such as incorrect recording medium selection or improper loading, thus improving reliability. can do.

[Brief description of drawings]

FIG. 1 is a block diagram showing a simplified structure of a compact disc reproducing apparatus 1 according to an embodiment of the present invention, FIG. 2 is a waveform diagram for explaining a control method of motors M1 and M2, and FIG. 3 is a flow chart for explaining the control operation shown in FIG. 1 ... Compact disk reproducing device, 2 ... storing means,
3 ... Compact disk, 4 ... Playback mechanism, 7 ... Optical pickup, 8 ... Soundizing circuit, 10 ... Operating section, 11
...... Control unit, 12 ...... Power supply circuit, 13 ...... Processing circuit, 14 ......
Analog / digital converter, 15 ... Micro computer, M1-M3 ... Motor, U1, U2 ... Driving circuit

Claims (1)

[Scope of utility model registration request] 1. A storage means for storing a plurality of recording media, a first motor for displacing the storage means, and a state in which the recording media can be selectively loaded for reproduction or recording. A recording medium reproducing apparatus including a second motor, a power supply, and control means for controlling the first and second motors by the power from the power supply, wherein voltage detection means for detecting the voltage of the power supply. And a control unit that lengthens a period for energizing the first and second motors when the power supply voltage decreases in response to the output of the voltage detection unit. apparatus.