KR100732548B1 - Ptical disk reproduction apparatus with switching level conversion function - Google Patents

Abstract

An optical disc reproducing apparatus having a switching level conversion function is provided to correctly recognize a switching signal of a high state of a DSP(Digital Signal Processor) unit although a high recognition level of a DVD(Digital Video Disc) LD(Laser Diode) of a pickup unit is higher than a voltage level of the switching signal of the high state of the DSP unit and turn on the DVD LD. A switching level converting unit(15) amplifies a voltage level of a switching signal outputted from a DSP unit(16) as a predetermined level necessary for selecting a target LD among a plurality of LDs, and provides the amplified switching signal to a pickup unit(12). The switching level converting unit(15) selects and drives the target LD among a plurality of the LDs. The switching level converting unit(15) is formed between the pickup unit(12) and the DSP unit(16).

Description

Optical disc player with switching level conversion function {PTICAL DISK REPRODUCTION APPARATUS WITH SWITCHING LEVEL CONVERSION FUNCTION}

1 is a control block diagram of an optical disk reproducing apparatus having a switching level converting function according to the present invention.

FIG. 2 is a circuit diagram of the switching level converter of FIG. 1.

* Description of the symbols for the main functions of the drawings *

10 optical disc 11 spindle motor

12 pickup unit 13 servo drive unit

14 control unit 15 switching level conversion unit

16: DSP unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc reproducing apparatus, and more particularly, to a DVD / CD capable of converting a level of a switching signal for selectively driving a DVD disc laser diode or a CD disc laser diode in an optical pickup. An optical disk reproducing apparatus having a switching signal level converting function.

In general, optical disc playback apparatuses include optical discs such as compact disc (CD), compact disc-read only memory (CD-ROM), laser disc (LD), mini disc (MD), digital video disc (DVD), and the like. It is a device for reproducing information recorded on a corresponding disc.

In such an optical disc reproducing apparatus, since there are various types of optical discs, it is necessary to be able to determine the type of the mounted disc. In particular, in an optical disc reproducing apparatus such as a DVD player, which can be used not only as a DVD series disc but also as a CD series disc, data type can be properly reproduced only when the type of the mounted disc can be accurately detected.

To this end, in the conventional optical disc reproducing apparatus, when a tray of a DVD series or a CD series is inserted into a tray and the tray is closed, the DSP unit outputs a switching signal for turning on the DVD diode in the pickup unit, thereby outputting a DVD / CD laser in the pickup unit. Turn on the DVD diode among the diodes and check the focus error during the focus search. The DSP unit determines the type of the loaded disc based on the checked focus error. Thereafter, the DSP unit turns on the DVD laser diode (hereinafter referred to as DVD_LD) or the CD laser diode (hereinafter referred to as CD_LD) by outputting a switching signal corresponding to the type of disc determined by the pickup unit.

Looking further at the operation between the DSP section and the pickup section, the DSP section typically consists of a single chip IC and has a decoder function and an RF signal processing function. When the DSP unit outputs the "high" switching signal, the pickup unit recognizes it and turns on the DVD_LD. When the DSP unit outputs the "low" state switching signal, the pickup unit recognizes it and turns on the CD_LD. .

However, as an example, the "high" switching signal output from the DSP unit is fixed by design to 3.3V, the maximum voltage level that can be output. Therefore, if the recognition level for acknowledging the "high" of the switching circuit in the pickup unit is set to 2.5V, it does not matter lower than 3.3V, but the "high" state acknowledgment level of the switching circuit in the pickup unit is set to 4.3V. In this case, although the recognition level is higher than 3.3V, the DSP unit recognizes the switching signal in the “low” state even though the DSP outputs the “high” state, and there is a problem of incorrectly turning on the CD_LD instead of the DVD_LD.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a "high" state of the DSP unit even if the "high" acknowledgment level of the DVD_LD of the pickup unit is higher than the voltage level of the switching signal of the "high" state of the DSP unit. The present invention provides an optical disc reproducing apparatus having a switching level converting function capable of correctly recognizing a switching signal and turning on a DVD_LD.

An optical disc reproducing apparatus having a switching level converting function of the present invention for achieving the above object includes a pickup unit for driving a laser diode corresponding to a voltage level of an input switching signal, the plurality of laser diodes, and the plurality of laser diodes. An optical disc reproducing apparatus having a DSP section for outputting a switching signal for selectively driving any one of the laser diodes, wherein the voltage level of the switching signal output from the DSP section is selected from among the plurality of laser diodes. And a switching level converting unit configured to amplify to a predetermined level necessary for selection and provide the pick-up unit so as to select and drive a desired laser diode from the plurality of laser diodes.

The switching level converting unit is provided between the pickup unit and the DSP unit.

The switching level converting unit amplifies and converts the switching signal of the "high" state of the DSP unit higher than the "high" recognition level of the pickup unit.

The switching level converting unit is a first transistor turned on by a switching signal of a "high" state output from the DSP unit, a second transistor turned off by the on of the first transistor, and the off by the second transistor And a voltage dividing circuit provided to output the divided voltage to the pickup unit.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

As shown in FIG. 1, the optical disc reproducing apparatus having a switching level converting function according to the present invention includes an optical disc 10, a spindle motor 11, a pickup unit 12, a server driver 13, and a controller 14. ), A switching level converting unit, and a DSP (Digital Signal Processor) unit 16.

The control unit 14 performs the preceding operation for discrimining the optical disc of the optical recording and reproducing apparatus and the overall control for performing various reproduction related functions.

The spindle motor 11 is driven by the control of the servo drive unit 13 to rotate the optical disc 10 and to transport the pickup unit 12 in the circumferential direction of the disc 10.

The pickup unit 12 optically picks up the information recorded on the optical disc 10, generates an RF (Radio Frequency) signal converted into an electrical signal, and outputs the RF signal to the DSP unit 16. The pickup section 12 includes a switching circuit for selectively switching the driving of the DVD_LD, the CD_LD and the DVD_LD and the CD_LD. The pickup section 12 also includes an objective lens, a focusing actuator, and a tracking actuator. The focusing actuator is driven by the control of the servo driver 13 to move the objective lens in the optical axis direction, and the tracking actuator is moved by the control of the servo driver 13 in the circumferential direction of the optical disk 10 to track the track. do.

The DSP unit 16 restores the information data by amplifying, waveform shaping, demodulating, and error correcting the RF signal applied from the pickup unit 12, and then the type of the mounted optical disk is a DVD-based or CD-based disk. Determine. Also, for this purpose, the DSP unit 16 outputs a switching signal of a “high” state for turning on the DVD_LD in the pickup unit 12 or a switching signal of a “low” state for turning on the CD_LD to the pickup unit 12. .

The switching level converting section 15 converts and amplifies the voltage level of the switching signal output from the DSP section 16. The switching level converting section 15 is provided between the DSP section and the pick-up section 12 and is output from the DSP section 16. Amplifies and converts the voltage level of the switching signal in the " At this time, the voltage level of the switching signal of the "high" state output from the DSP unit 16 is set by setting the preset level to the "high" recognition level of the switching circuit of the pickup unit 12. Even if it is lower than the "high" acknowledgment level of the switching circuit, the amplification can be amplified so that the pick-up unit 12 can recognize the normal "high" state, thereby enabling the DVD_LD to operate normally.

That is, for example, the "high" state switching signal output from the DSP unit 16 is fixed by design to 3.3 V, which is the maximum voltage level that can be output, and the "high" recognition level of the switching circuit in the pickup unit 12. When this is set to 2.5V, since the switching level converting section 15 is amplified and converted to 2.5V or more, the switching circuit in the pickup section 12 can recognize "high" and "low" more accurately. When the "high" state acknowledgment level of the switching circuit in the pickup section 12 is set to 4.3 V, the switching in the pickup section 12 is amplified and converted to 4.3 V or more by the switching level converting section 15. The circuit can recognize “high” and “low” more accurately. In addition, this switching level amplification method additionally causes the output of the DSP unit 16 to be reduced due to its own output error of the DSP unit 16. Even if weakened, it is possible to prevent incorrect recognition of the pickup unit 12. It is good.

Looking at the configuration of the switching level converting section 15 with reference to Figure 2, the switching level converting section 15 is electrically connected between the output side of the DSP section 16 and the input side of the pickup section 12. The switching level converting unit has a first terminal connected to an output terminal of the DSP unit 16 via a resistor R1, a collector terminal connected to a power supply V4 via a resistor R2, and an emitter terminal connected to ground. The transistor Q1 and the base terminal are connected to a line branched from the collector terminal of the first transistor Q1 via a resistor R3, and the collector terminal is connected to a power supply V4 via a resistor R4. In order to apply the voltage divided by the resistor R4 and the resistor R5 to the pick-up unit 12 when the second transistor Q2 having the emitter terminal connected to the ground and the second transistor Q2 is turned off, A resistor R5 is provided in the connection line between the branch point between the second transistor Q2 and the resistor R4 and the emitter terminal of the second transistor Q2 so as to form a voltage distribution circuit with the resistor R4. At this time, the input side of the pickup section 12 is connected to the connection point between the resistor R4 and the resistor R5.

Therefore, when the voltage level of the switching signal of the DSP unit 16 is "low", the switching signal of the "low" state is applied to the base of the first transistor Q1 and the first transistor Q1 is turned off. At this time, since the node N1 is connected to the power supply V4 and becomes a "high" state, the second transistor Q2 is turned on. The second transistor Q2 is connected to the ground side, and 0V (voltage V3) in a "low" state is applied to the pickup unit 12. Accordingly, the switching circuit in the pickup unit 12 turns on the CD_LD according to the switching signal of the "low" state.

On the other hand, when the voltage level of the switching signal of the DSP unit 16 is "high", the switching signal of the "high" state is applied to the base of the first transistor Q1 to turn on the first transistor Q1. At this time, since the node N1 is connected to the ground side to be in the "low" state, the second transistor Q2 is turned off. When the second transistor Q2 is in the off state, the node N2 outputs a voltage V3 having a "high" state in which the voltage level divided by the resistor R4 and the resistor R5 is amplified and is output. 12) is applied. Accordingly, the switching circuit in the pickup unit 12 turns on the DVD_LD according to the switching signal of the "high" state in which the voltage level is further amplified. At this time, the level of the voltage divided by the resistor R4 and the resistor R5, which is the voltage of the node N2, is set higher than the "high" acknowledgment level of the switching circuit in the pickup section 12.

As described in detail above, the present invention amplifies and compensates when the switching signal output of the DSP unit is lower than the logical 'high' acknowledgment level of the switching signal in the pickup unit, so that the switching signal of the DSP unit is to turn on the DVD_LD. It is more effective to recognize whether to turn on the appropriate laser diode has the effect that can be driven.

In addition, the present invention has an effect that it is possible to prevent inaccurate recognition of the switching signal in the pickup unit even when the output level of the switching signal is weakened due to the output error of the DSP unit.

Claims (4)

A light having a plurality of laser diodes, including a pickup for driving a laser diode corresponding to the voltage level of the input switching signal, and a DSP for outputting a switching signal for selectively driving any one of the plurality of laser diodes In the disc player, Selecting a desired laser diode among the plurality of laser diodes by amplifying the voltage level of the switching signal output from the DSP unit to a predetermined level necessary for selecting a desired laser diode among the plurality of laser diodes An optical disc reproducing apparatus having a switching level converting function comprising a switching level converting portion for driving by driving. An optical disc reproducing apparatus having a switching level converting function according to claim 1, wherein said switching level converting section is provided between said pickup section and said DSP section. The light having a switching level converting function according to claim 1 or 2, wherein the switching level converting section amplifies and converts the switching signal of the "high" state of the DSP section higher than the "high" recognition level of the pickup section. Disc player. The switching transistor of claim 1, wherein the switching level converting unit is a first transistor turned on by a switching signal of a “high” state output from the DSP unit, a second transistor turned off by turning on the first transistor, and the first transistor; And a voltage dividing circuit arranged so that the voltage distributed by turning off the two transistors is outputted to the pickup portion.

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