KR20000041213A - Circuit and method for jumping layer in optical disc reproducing apparatus of multi layer recording method - Google Patents

Abstract

PURPOSE: A circuit and a method for jumping a layer in an optical disc reproducing apparatus of a multi-layer recording method are provided to stably perform a jump action in spite of sensitivity change of a picking up. CONSTITUTION: A method for jumping a layer in an optical disc reproducing apparatus of a multi-layer recording method includes nine steps. The first step is to detect a focus error signal and generate a starting signal(kick) to jump a pick up from a starting layer to an object layer. The second step is to judge whether the focus error signal is descended from the peak part for the starting layer to a first predetermined level. The third step is to dissolve the starting signal when the focus error signal is descended. The fourth step is to detect a first time value from the point of time supplying the starting signal to the point of time dissolving. The fifth step is to judge whether the focus error signal is ascended as a predetermined second level. The sixth step is to generate a braking signal when the focus error signal is ascended. The seventh step is to detect a second time value from the point of time dissolving the starting signal to the point of time generating the barking signal. The eighth step is to detect a maintaining time of the braking time using the first and second time values. The ninth step is to dissolve the braking time when the maintaining time is over.

Description

Layer Jumping Method and Circuits of a Multi-layer Recording Optical Disc Playback Device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a layer jump method and a circuit thereof of a multi-layer recording type optical disc reproducing apparatus, and more particularly to a digital video disc dual reproducing apparatus having a layer 0 and a layer 1, Multi-layer recording type optical disc which can perform more stable jump operation by calculating braking amount from time measurement of each section to be moved when jumping between layer 0 and layer 1 and characteristic of pickup (relative torsional distortion) measured at driving A layer jump method of a playback apparatus and a circuit thereof.

In general, optical recording media such as compact discs, digital video discs, etc., have a capacity of several inches in diameter and a thin thickness of 1.2 mm, compared to floppy discs, which are magnetic recording media having a capacity of 2 megabytes. Hundreds of times hundreds of megabytes of data storage capability, and as a data recording layer for storing information such as sound, text, graphics, etc., which is a combination of pits formed concave on the reflective surface and reflected by light. As a medium, along with the development of such a compact disc having such a large capacity of storage, the development of an optical disc reproducing apparatus for reading data stored at high density with high precision and high speed without a read error is steadily progressing.

In addition, such an optical disc reproducing apparatus has been developed with the development of a reproducing apparatus capable of mixing and reproducing various types of optical discs, which enables a user to reproduce an arbitrary optical disc in combination through one optical disc reproducing apparatus.

Optical discs are usually divided into compact discs and digital video discs. Here, the compact disc is divided into a product that combines audio information only and video information and audio information, and a digital video disc is a single digital video disc in which only one information is recorded in a single layer on one track. (Digital Video Disk Single: DVD-S) and a digital video disk dual (DVD-D) in which two pieces of information are recorded simultaneously in a dual layer.

At this time, the compact disc, the digital video disc single, and the digital video disc dual have different recording forms, and thus the waveforms of the signals obtained by the pickup apparatus are also different from each other. Therefore, when the playback operation is performed under the same conditions, the respective optical discs cannot be used in combination.

Conventionally, the following two methods are applied as a method for selecting a playback mode.

First, when the user visually checks the type of the optical disc loaded in the reproducing apparatus to set the reproduction mode, and secondly, the type of the optical disc loaded is automatically detected.

At this time, in the second case, after setting to any mode in the playback apparatus, the information recorded on the optical disc is reproduced. In this case, if the playback operation is performed normally, the type of the optical disc and the predetermined random mode coincide with each other. If the playback operation is not performed normally, the type of the optical disc and the predetermined random mode are different from each other. After setting to any other mode, repeat the above process.

1 is a cross-sectional view of a digital video disc dual. Layer 1 is made of an aluminum reflective layer, and layer 0 is made of a semi-reflector. The reason why the optical disc is produced by the multi-layer recording method is to increase the storage capacity. When the optical disc is produced by the dual layer, the storage capacity is increased to 17 gigabytes (GB). FIG. 2 is a diagram showing capacities of types of digital video discs. The advantage of the multi-layer recording disc over the double-sided disc is that the recording surface of the optical disc does not have to be reversed during reproduction.

Typically, Layer 1 of a digital video disc dual has two track paths. First, as in layer 0, there is a parallel track path (see FIG. 3A) that runs from the inner circumference to the outer circumference and an inverse track path (see FIG. 3B) that runs from the outer circumference to the inner circumference. In particular, when playing back image information recorded on an optical disc produced by an inverse track case, since both layers 0 can be played out to the outer periphery and then jumped to the layer 1 instantaneously, playback can be continued from the same outer periphery. There is an advantage that disconnection of the image information does not occur.

Jumping on a digital video disc dual means quickly moving the focus from one layer to another within a few seconds. 4 shows the movement direction of the pickup and the focus error signal when jumping from layer 0 to layer 1. In the case of moving in the reverse direction with respect to FIG. 4 (in the case of moving from layer 1 to layer 0), the focus error signal is detected as an inverted phase with respect to FIG.

When the distance between layers is 55 占 퐉, the pure time taken to jump between layers is set at an average of 5 ms at 1x speed and 1.5 ms at 2x speed. This is to reduce the influence of the deflection. That is, when the rotational speed of the optical disc is doubled, the influence of deflection is 1/2 times faster on the time axis. The basis for this can be inferred from Equations 1 to 4 below.

As a result, for an optical disc with a deflection standard of 1 mm, a travel time of 55 占 퐉, which is a spaced interval between layers, becomes 5.4 s at 1x speed and 2.7 s at 2x speed from Equation 4 above.

Meanwhile, the jump circuit applied by Toshiba (Japan) is as shown in FIG. 5. That is, the jump-related device IC TC9461F is provided with TEST100 and TEST101 terminals for generating the start signal Kick and the brake signal Brake, and are configured to generate a series of jump operations as one command. It is. 6 illustrates a timing diagram when the jump circuit shown in FIG. 5 operates. According to the conventional jump circuit as described above, a braking signal Brake is generated at the point of focus-on after the jump operation. The braking signal B is controlled by simultaneously controlling the start signal Kick and the braking signal Brake according to one command. It is difficult to select the correct focus even if the gain value of the focus error signal is considerably increased because the occurrence time of the brake is late. In particular, such a problem is more prominent in a deflection disc.

In order to solve this problem, a method of adding a separate circuit for controlling only a brake signal using a TEST100, a focus standby level detection signal, has been proposed (see FIG. 7). Using this circuit, as shown in Fig. 8, the braking signal Brake can be applied immediately before the Focus Zero Cross, but the deviation still occurs every time the jump is made. In particular, when the impulse is increased and the capacity value is increased, the jump speed deviation becomes larger. On the contrary, when the impulse is decreased and the capacity value is increased, the jump time is much longer. Big problems arise.

However, according to the conventional multi-layer recording type optical disc reproducing apparatus, the following problems arise.

First, due to the nature of the impulse, even if a strong force is initially applied, it gradually becomes weaker as time passes, and thus the sensitivity of the actuator is small so that the pickup does not move sufficiently at the beginning of the start signal, as shown in FIG. 9. In some cases, the return to the target layer does not occur. On the contrary, when the sensitivity is high, the pickup may pass the target layer in a state where the pickup is not braked.

Secondly, if the impulse size is reduced and the slope is gentle, even a small force can provide a constant force to the pickup, which theoretically prevents the return or overshoot, but it takes longer to jump. As a result of the deflection, a phenomenon in which the target layer does not reach the target layer and returns or passes the target layer occurs.

Third, in order to absorb the deviation of the pickup, the jump state must be detected from the focus error signal during the jump, and the detected signal is fed back to the focus driving signal to compensate for this. As it is, there is no countermeasure.

Fourth, since the same amount of force is always transmitted to the actuator, the actual jumping speed depends on the sensitivity of the actuator.

Fifth, a method of using a square wave instead of an impulse and varying the time of the start signal Kick and the brake signal Brake is presented. That is, according to the method of varying the start signal Kick and the brake signal Brake, the point of releasing after supplying the start signal Kick falls by a predetermined level after the peak portion of the S-curve of the starting layer. Next, the timing of supplying the brake signal Brake is when a predetermined level of the S-curve of the target layer starts to appear. Then, the time for releasing the braking signal Brake is set to a time after a predetermined time has elapsed from the time when the braking signal Brake is provided, or a time after falling down by a predetermined level from the peak portion of the S-curve of the target layer. There is this.

However, the method of setting the braking signal Brake to a point after a predetermined time has elapsed from the point of time when the braking signal Brake is provided does not absorb the deviation caused by the change of the force of the start signal Kick.

In addition, the method of setting the time point after descending from the peak portion of the S-curve by a predetermined level increases the magnitude of the braking signal Brake in the state where the S-curve is slow, and the braking signal Brake in the state where the S-curve is fast. Since there is a contradiction point in which the size of the? Decreases, the accuracy of the jump is improved when the start signal Kick is large and the deviation is small, but as the deviation increases, the probability of failure increases.

Accordingly, an object of the present invention is to provide a layer jump method of a multi-layer recording type optical disc reproducing apparatus, which can perform a stable jump operation even in a sensitivity change of a pickup and an actuator. have.

Another object of the present invention is to provide a layer jump circuit of a multi-layer recording type optical disc reproducing apparatus for performing the above layer jumping method.

1 is a cross-sectional view of a digital video disc dual,

2 is a diagram showing capacities of types of digital video discs;

3A is a diagram for explaining a parallel track path,

3B is a diagram for explaining a reverse track path.

4 is a diagram illustrating a pickup movement direction and a focus error signal when jumping from layer 0 to layer 1;

5 is a conventional first jump circuit diagram,

6 is an operation timing diagram according to the jump circuit shown in FIG. 5,

7 is a conventional second jump circuit diagram;

8 is an operation timing diagram according to the jump circuit shown in FIG.

9 is a waveform diagram when the pickup returns to the initial layer without reaching the target layer in a state where the power of the start signal is insufficient;

10 is a view for explaining the concept of the present invention, is a waveform diagram according to the change of the accumulated energy,

FIG. 11 is a waveform diagram of a focus error signal output when the pickup moves in the up direction in the focus search operation;

12 is a distribution of P 'and D' values for an arbitrary product,

13 is a layer jump circuit diagram according to the present invention;

14 is an operation flowchart showing a process of performing a layer jump method according to the present invention;

15 is a waveform diagram of a focus error signal and a focus driving signal detected when a jump operation is performed from layer 0 to layer 1;

16 is a waveform diagram of a focus error signal and a focus driving signal detected when a jump operation is performed from layer 1 to layer 0,

FIG. 17 shows a parts list between a conventional layer jump circuit and a layer jump circuit improved by the present invention.

<Description of the code | symbol about the principal part of drawing>

COMP: comparator Q1, Q2: switching transistor

R1 to R5: voltage divider resistance Vref: reference voltage

A feature of the present invention for achieving the above objects is a reproducing apparatus comprising a multi-layer recording type optical disc having at least two layers and a pickup for reproducing the optical disc: detecting a focus error signal, and picking up the pickup at the starting layer. Generate a start signal Kick for jumping to the target layer; Determining whether the focus error signal has fallen from the peak portion for the starting layer by a predetermined first level; Canceling the start signal Kick when the focus error signal falls from the peak portion for the start layer by a first predetermined level; Detecting a first time value from a supply point of the start signal Kick to a release point; Determining whether the level of the focus error signal has risen by a predetermined second level; Generating a brake signal when the level of the focus error signal rises by a predetermined second level; Detecting a second time value from the time when the start signal Kick is released to the time when the brake signal Brake is generated; Detecting the holding time of the brake signal using the first time value and the second time value; The braking signal Brake is released when the holding time of the braking signal Brake elapses.

Here, the holding time of the braking signal is

Is calculated by.

On the other hand, another feature of the present invention is a layer jump circuit for generating a jump signal in which timing of a start signal Kick and a brake signal Brake are controlled according to a control signal of a microcomputer: a pair output from a microcomputer. A switching unit configured to control a switching state according to a control signal of the controller to control a start point and a release point of a start signal Kick and a brake signal Brake; A voltage adjusting unit controlling a voltage level of the start signal Kick and the brake signal Brake switched by the switching unit; And a comparator which compares a signal switched by the switching unit and whose voltage level is adjusted by the voltage adjusting unit with a signal having a predetermined voltage holding level and generating a layer jump signal according to the result.

Here, the switching unit and the first switching element for switching between the reference voltage (Vref) and twice the predetermined reference voltage (2Vref) according to the control signal output from the microcomputer; And a second switching device for switching between a preset reference voltage Vref and a ground voltage GND according to a control signal output from the microcomputer.

At this time, the first switching element includes a transistor for switching the on-off state is switched in accordance with the control signal output from the microcomputer so that twice the reference voltage Vref is applied to the comparator; The second switching device includes a transistor for switching the on-off state to be switched according to a control signal output from the microcomputer to apply the reference voltage Vref to the comparator.

And the first switching element is a PNP type transistor, and the second switching element is composed of an NPN type transistor; When the control signals output from the microcomputer to the first switching element and the second switching element are respectively "0 and 0", the comparator outputs a start signal Kick; When the control signals output from the microcomputer to the first switching element and the second switching element are "1 and 0", the comparator outputs a signal of a voltage holding level; When the control signals output from the microcomputer to the first switching element and the second switching element are "1 and 1", the comparator outputs a brake signal Brake.

In addition, the voltage regulator is composed of a plurality of voltage divider resistor to adjust the voltage level switched in the switching unit to a predetermined size and supply it to the comparator.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, in adding reference numerals to the elements of each drawing, it should be noted that the same elements are denoted by the same reference numerals as much as possible even if they are displayed on different drawings. In addition, in the following description, many specific details are shown, such as specific blocks or components of circuits, which are provided to help a more general understanding of the present invention, and the present invention may be practiced even if these specific details are removed or modified. It will be obvious to those of ordinary skill in the art. In describing the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

First, an outline principle of the layer jump method of the basic multilayer recording method optical disc reproducing apparatus will be described.

The jump in the multi-layer recording type optical disc shifts from the stop state to the vertical direction of the optical disc and changes to the stop state when the target layer is reached. In other words, most of the energy accumulated by the force moving from the stationary state is consumed to move, and when all the accumulated energy is consumed, the energy is converted back to the stationary state. A waveform diagram according to the change of the accumulated energy is shown in FIG. 10.

In FIG. 10, the section A is a kick power level section, and when the section signal falls from the peak portion of the S-curve of the focus error signal generated when the first layer departs from the first layer, the start signal is blocked. do. All the energy needed to jump between layers is accumulated in section A.

Section B is subject to the DC Hold Level. At this time, the DC Hold Level is the force that holds the position of the first layer. Are destroyed and the actuator returns to the position of the first layer. There are two main reasons why the accumulated energy is lost. One is due to the inherent load of the actuator and the other is due to the restoration to the DC Hold Level. And these two forces are not linear, but they work across sections A, B, and C.

Section C is a brake power level section and applies a brake signal from the point where a certain level of the S-curve that occurs when reaching the target layer is detected, and is accumulated in section A and in section B. The brake signal is applied for a time enough to cancel all the remaining energy even after some loss. This time can be calculated from the measured times A and B.

P represents the strength of the start signal Kick and the strength of the brake signal Brake. The start signal Kick and the brake signal Brake may be supplied at different intensities, but it is meaningless to make the intensities different because the elements of time are already provided differently to control the amount of energy. It is easy to control when supplying.

D is a value set assuming that the two forces mentioned in the description of section B, the restoring force to the actuator load and the DC hold level, are linear. This logic is expressed by the following equation (5).

A × (P-D) + B × (-D) + C × (-P-D) = 0

Here, A and B are measurable values, but C should be obtained from A and B. If Equation 2 is defined for C, Equation 6 is given below.

A and B are measured using a timer in a microcomputer, and P is a fixed value reflected by the firmware to calculate the strengths of the kick and brake signals determined by the hardware. . D should be measured and set for each set because its value varies depending on the pickup. This value is related to the sensitivity of the actuator, which can be detected at the rate when the pickup is up / down to perform the focus search operation.

When pick-up speed is measured during the search operation, although the voltage of the same slope is applied to the actuator, the actual moving speed varies depending on the sensitivity of the actuator. By measuring the elapsed time from the surface reflection to the data layer during the focus search, the deviation between the pickups can be relatively determined.

In the case of a digital video disk, the distance from the surface reflection to the data layer is about 0.6 mm, and the focus error signal output when the pickup is moved in the up direction in the focus search operation is shown in FIG.

From the measured time, the following formula (7) can be obtained. D is determined as the inherent load and the circuit factor according to the sensitivity of the actuator, and is composed of a common load with little variation in sets.

D = actuator inherent load (Ln) + common load (Lc)

The larger the intrinsic load Ln of the actuator, the larger the elapsed time, and the smaller the intrinsic load, the smaller the elapsed time. Therefore, the intrinsic load of the actuator is proportional to the elapsed time. Therefore, Equation 7 may be defined as Equation 8 to Equation 12 below.

Ln = elapsed time (S) x coefficient (T)

D = S × T + Lc

D = (S + U) × T

Therefore, if U (substituted for simplicity) and T are appropriately selected for the system, D value can be obtained from the measured elapsed time.

Due to the characteristics of the firmware control, the variables shown in Equations 8 to 12 should be selected as integers for easy control, and P and D are proportional to each other, so that they can be easily controlled by the microcomputer within the limit of the proportional equation. May be modified as in Equation 13 and Equation 14 below.

P: D

P: (S + U) × T

In this case, since P is generally larger than D, the resolution may be increased by modifying Equations 13 and 14 as shown in Equations 15 to 17 so that larger values change.

Here, in order to increase the resolution, an integer (eg, 3) may be multiplied by both sides, as shown in Equations 18 to 20.

D ′ = 3

Therefore, when P 'and D' are substituted into Equation 6, Equation 21 below is used.

The values of P 'and D' are selected as integers to facilitate control in the microcomputer, and can be selected according to the distribution diagram as shown in FIG. In addition, the P value is determined in hardware, and is determined by the values of the resistors R1 to R5 shown in FIG.

13 shows a layer jump circuit diagram according to the present invention.

Referring to FIG. 13, the layer 0 and layer 1 signals output from the microcomputer are provided to the base terminals of the switching transistors Q1 and Q2. Here, the microcomputer can output the layer 0 and layer 1 signals in four cases of "0", "1", "10", and "11", where a pair of switching transistors Q1 and Q2 are used. Except for " 10 ", which is all turned on, the FOD signal shown in FIG. 10 is generated using the remaining three cases.

More specifically, if layer 0 and layer 1 are "0", the switching transistor Q1 is turned off and the switching transistor Q2 is turned on. Therefore, the output FOD signal becomes the start signal kick section of FIG.

If layer 0 and layer 1 are "1", the switching transistor Q1 is turned off and the switching transistor Q2 is turned off. Accordingly, the output FOD signal becomes the voltage holding level section of FIG. 10 due to the voltage hold level DC input to the inverting terminal (−) of the comparator COMP.

If layer 0 and layer 1 are " 11 ", the switching transistor Q1 is turned on and the switching transistor Q2 is turned off. Accordingly, the output FOD signal becomes the brake signal brake section of FIG. 10.

At this time, the voltage level of the start signal Kick and the brake signal Brake is determined according to the resistance values of the plurality of resistors R1 to R5, and thus the amount of energy accumulated at the start and the amount of energy required for braking are determined. .

The operation of the present invention as described above will be briefly described with reference to FIG. 14 as follows.

When a jump command is received from layer 0 to layer 1 (S101), the microcomputer in the digital video disc dual player switches to the layer jump mode (S102). Then, the current focus error level is measured (S103). At this time, the input focus error signal is digitized using an analog-to-digital converter in a microcomputer, and then the level is measured. Thereafter, the microcomputer turns off the linear speed constant servo (CLV servo) (S104). Here, since the rotation speed of the optical disk is not constant, the inner speed is fast and the outer speed is slow, so that the servo is controlled to have a linear speed of 1.2 to 1.4 m / s. It is called.

When this process is complete, the microcomputer starts the layer jump. That is, the microcomputer applies the start signal Kick to a predetermined intensity (S105), and then operates an timer to count the operation time (S106).

Thereafter, the microcomputer checks whether the focus error signal generated when leaving the first layer has fallen from the peak portion of the S-curve by a predetermined level (S107). Here, the predetermined predetermined level is a value determined by a plurality of experiments, and A and B values are detected according to the predetermined level value, and thus the value must be set in advance when designing the system.

If it is determined in step 107 (S107) that the focus error signal has fallen from the peak of the S-curve by a predetermined level, the microcomputer blocks the start signal Kick (S108), and stops counting the timer. Afterwards, the elapsed time A counted up to now is stored in the storage means (S109). Then, the microcomputer restarts the counting operation after resetting the timer (S110).

Thereafter, the microcomputer checks whether TEST100, which is a focus standby level detection signal, is activated (S111). In other words, it is checked whether the focus error signal is detected at a predetermined level or more in the S-curve. Here, when the TEST100 is activated, the microcomputer applies the brake signal Brake (S112), stops the timer, and stores the elapsed time B counted to the present time (S113).

The microcomputer calculates C by inserting the elapsed times A and B measured by the timer into Equation 21, and continuously applies the brake signal Brake by the calculated delay time C (S114). Thereafter, when the time when the braking signal is applied passes the delay time C, the microcomputer blocks the braking signal Brake (S115), waits for the servo to stabilize for a predetermined time (S116), and the layer jump mode. To release (S117), the system is switched to the normal mode (Normal Mode) (S118).

Thereafter, the microcomputer checks whether focusing is normally performed with respect to layer 1 (Focus OK) (S119), and if it is determined that normal focusing with respect to layer 1 is performed at step 119 (S119), a tracking servo is performed. And turn on the linear speed constant servo (CLV servo) (S120).

If it is determined in step 120 (S120) that normal focusing for layer 1 is not performed, an error flag is set (S121), and the layer jump operation is terminated.

15 shows a focus error signal and a focus driving signal when jumping from layer 0 to layer 1, and FIG. 16 shows a focus error signal and a focus driving signal when jumping from layer 1 to layer 0. As can be seen in FIGS. 15 and 16, the focus error signal and the focus driving signal when jumping from layer 0 to layer 1 and from layer 1 to layer 0 are the same waveforms with the phases reversed, respectively. have.

In addition, the layer jump circuit according to the present invention has a side effect of reducing components and reducing costs, as shown in FIG. 17, compared to a conventional jump circuit (for example, the Toshiba jump circuit). do.

As described above, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by the claims below and equivalents thereof.

As a result, according to the layer jump method and the circuit of the multilayer recording method optical disc reproducing apparatus according to the present invention, the following advantages arise.

First, the start signal Kick and the brake signal Brake may be generated at a preset time point by a predetermined amount of energy corresponding to the focus error signal detected by the pickup, thereby responding to a change in sensitivity of the actuator and the pickup.

Second, since the force (intensity of the start signal and the braking signal) supplied to the actuator is varied according to the focus error signal, stable jump operation can be performed.

Third, by setting the strength of the start signal Kick and the brake signal in advance in hardware, it is possible to always maintain a constant intensity regardless of the change in the slope of the focus error signal. Thus, stable jump operation is performed.

Fourth, since the stable jump operation is performed even when the deviation of the pickup is large, the failure rate of the pickup is reduced, and the stability of the product is improved.

Fifth, when the start time and release time of the start signal Kick and the brake signal Brake are incorporated in the servo processor to perform independent servo control, the stability of the jump operation is further improved.

Claims (8)

A reproduction apparatus comprising a multi-layer recording optical disc having at least two layers and a pickup for reproducing the optical disc: Detecting a focus error signal and generating a start signal (Kick) for jumping the pickup from a start layer to a target layer; Determining whether the focus error signal has fallen from a peak portion of the starting layer by a predetermined first level; Releasing a start signal when the focus error signal falls by a predetermined first level from a peak portion of the start layer; Detecting a first time value from a supply point of the start signal to a release point; Determining whether the level of the focus error signal has risen by a preset second level; Generating a brake signal when the level of the focus error signal rises by a predetermined second level in the determining step; Detecting a second time value from when the start signal Kick is released to when the brake signal Brake is generated; Detecting a holding time of the brake signal using the first time value and the second time value; And releasing the brake signal (Brake) when the holding time of the brake signal (Brake) elapses. The method of claim 1, wherein the holding time of the braking signal is The layer jump method of a multilayer recording method optical disc reproducing apparatus, characterized by the above-mentioned. In the layer jump circuit for generating a jump signal in which the timing of the start signal Kick and the brake signal Brake is controlled according to the control signal of the microcomputer: A switching unit configured to control a switching state according to a pair of control signals output from the microcomputer to control generation and release points of the start signal and the brake signal; A voltage adjusting unit controlling a voltage level of the start signal Kick and the brake signal Brake switched by the switching unit; And Multi-layer recording type optical disc reproducing comprising a comparator which is switched by the switching unit and compares a signal whose voltage level is adjusted by the voltage adjusting unit with a signal of a predetermined voltage holding level and generates a layer jump signal according to the result. Layer jump circuit of the device. The method of claim 3, wherein the switching unit, A first switching element configured to switch between two times the reference voltage (2Vref) and the reference voltage Vref according to the control signal output from the microcomputer; And And a second switching device for switching between a predetermined reference voltage (Vref) and a ground voltage (GND) in accordance with the control signal output from the microcomputer. The method of claim 4, wherein the first switching device, A layer jump of a multi-layer recording type optical disc reproducing apparatus including a transistor for switching an on-off state according to the control signal output from the microcomputer to switch twice the reference voltage (Vref) to the comparison unit. Circuit. The method of claim 4, wherein the second switching device, And a transistor for switching an on-off state according to the control signal output from the microcomputer to switch the reference voltage (Vref) to be applied to the comparator. The method according to claim 5 or 6, The first switching element is a PNP type transistor, and the second switching element is composed of an NPN type transistor; Outputting the start signal (Kick) from the comparison unit when the control signals output from the microcomputer to the first switching element and the second switching element are respectively "0 and 0"; When the control signal output from the microcomputer to the first switching element and the second switching element is "1 and 0", the comparator outputs a signal of the voltage holding level; And the control unit outputs the brake signal (Brake) when the control signal output from the microcomputer to the first switching element and the second switching element is "1 and 1," respectively. Layer jump circuit of the optical disk player. The method of claim 3, wherein the voltage adjusting unit, A layer jump circuit of a multi-layer recording type optical disc reproducing apparatus, comprising: a plurality of voltage divider resistors to adjust the voltage level switched by the switching unit to a predetermined size.