JP2000090440A - Recording medium recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To exactly detect recording medium kinds by moving the entire lens block body in a focusing direction to vary the relative distance between an objective lens and an auxiliary lens and discriminating the presence or absence of the reflected light from the surface of the recording medium during the course of the movement as a first detection point and the presence or absence of the reflected light from a signal surface as a second by moving the entire lens block body. SOLUTION: The entire lens block body LB 1 is moved and the kind of an optical disk D which is the recording medium during the course of the movement is discriminated from the detection signal in accordance with the reflected light from the optical disk D by determining whether there is the reflected light from the surface d1 of the optical disk D or not as the first detection point and whether there is the reflected light from the signal surface d2 of the optical disk D or not as the second detection point. The signals of the reflected light from both of the surface d1 and signal surface d2 of the optical disk D are utilized and since the change in the reflected light at these points is distinct, the discrimination is made easier and the exacter discrimination is made possible. The discrimination time is shortened by the moving speed regulation of the discriminating means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording / reproducing apparatus for recording / reproducing a signal by condensing a light beam on a recording medium with a two-group lens structure including an objective lens and an auxiliary lens.

[0002]

2. Description of the Related Art An optical pickup of this type of recording medium recording / reproducing apparatus has an objective lens and an auxiliary lens, and an objective lens holder for holding the objective lens is provided on a base member via a first support member in a focusing direction. It is movably supported in the optical axis direction) and the tracking direction (vertical direction of the optical axis direction). An auxiliary lens holder for holding the auxiliary lens is supported by the objective lens holder via a second support member so as to be movable in a focus direction (optical axis direction).

[0003] All lens blocks including an objective lens holder and an auxiliary lens holder are configured to be moved in a focus direction and a tracking direction by a focus / tracking actuator. The auxiliary lens block including the auxiliary lens holder is configured to be moved in the focus direction by an auxiliary lens actuator.

[0004] In the above configuration, when the focus / tracking actuator is driven, all the lens blocks move, whereby the objective lens and the auxiliary lens are both moved in the focus direction and the tracking direction. By this movement, focus control and tracking control are performed. And the objective lens and the auxiliary lens
With the group lens configuration, a high numerical aperture can be realized without increasing the diameter of the objective lens.

When the auxiliary lens actuator is driven, the auxiliary lens moves in the focus direction, and the distance between the auxiliary lens and the objective lens is changed. That is, for example, when the thickness of the substrate is different depending on the type of the optical disc as the recording medium, if the distance between the objective lens and the auxiliary lens is the same, a large spherical aberration occurs, and this spherical aberration is a disturbance of the reproduction signal. Acts as
By adjusting the distance between the objective lens and the auxiliary lens depending on the type of the optical disk, the spherical aberration can be suppressed to a small value.

[0006]

However, conventionally, there has been no means for accurately detecting the type of recording medium by an optical pickup. For this reason, there has been a problem that the focus servo is not applied due to misidentification of the type of the recording medium, and an accident occurs in which the leading ends of all the lens block bodies collide with the recording medium. Such an accident is more likely to occur as the distance between all the lens block bodies and the recording medium, that is, the air gap becomes smaller, for high-density recording.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and has as its object to provide a recording medium recording / reproducing apparatus capable of accurately detecting the type of a recording medium.

[0008]

According to a first aspect of the present invention, there is provided an all-lens block body having an objective lens and an auxiliary lens, and converging a light beam on a recording medium with the two-group lens structure.
A first moving unit that moves the entire lens block body in the focus direction, a second moving unit that varies a relative distance between the objective lens and the auxiliary lens, and the first moving unit moves the entire lens block body. It is moved between a closest position closest to the recording medium and a farthest position sufficiently away from the recording medium, and a first detection point is used to determine whether or not there is light reflected from the surface of the recording medium in the moving process. And a recording medium type discriminating means for discriminating the type of the recording medium from a detection signal based on the reflected light from the recording medium with the presence or absence of reflected light from the signal surface of the recording medium as a second detection point. A recording medium recording / reproducing apparatus characterized by comprising:

According to a second aspect of the present invention, in the recording medium recording / reproducing apparatus according to the first aspect, the recording medium type discriminating means moves the all lens block bodies from a most remote position to a nearest position. The moving speed of all the lens block bodies is set to be high until the first detection point is detected, and the moving speed of the all lens block bodies is set to be low after detecting the first detection point.

According to a third aspect of the present invention, in the recording medium recording and reproducing apparatus according to the first aspect, when the second detection point is detected in the focus pull-in mode, the focus servo is locked from that point. It is characterized in that

According to a fourth aspect of the present invention, in the recording medium recording / reproducing apparatus according to the first aspect, the recording medium type discriminating means moves the entire lens block from a closest position to a remotest position. It is characterized by.

According to a fifth aspect of the present invention, in the recording medium recording / reproducing apparatus according to the first to fourth aspects, a memory storing distance data between the objective lens and the auxiliary lens corresponding to various recording media is provided. Desired distance data is read from the memory based on the determination result of the recording medium type determination unit, and a distance between the objective lens and the auxiliary lens is set based on the distance data. I do.

According to a sixth aspect of the present invention, in the recording medium recording / reproducing apparatus according to any one of the first to fifth aspects, the closest position is a position where the all lens blocks come into contact with the recording medium. It is characterized by the following.

According to a seventh aspect of the present invention, in the recording medium recording / reproducing apparatus according to any one of the first to sixth aspects, a recording medium for detecting whether or not all the lens block members are in contact with the recording medium. It is characterized by having contact detecting means.

According to an eighth aspect of the present invention, in the recording medium recording and reproducing apparatus according to the seventh aspect, at least one of the first moving means and the second moving means is a magnet or a coil. The electromagnetic actuator is configured as an electromagnetic actuator comprising: a voltage that generates a disturbance to which the electromagnetic actuator can respond, and the voltage is detected by measuring a back electromotive force from the electromagnetic actuator at this time. .

According to a ninth aspect of the present invention, there is provided an all-lens block body having an objective lens and an auxiliary lens for condensing a light beam on a recording medium with the two-group lens structure, and moving the all-lens block body in a focus direction. Means for moving the entire lens block, and moving the entire lens block between the contact position where the lens block is brought into contact with the recording medium and the farthest position sufficiently away from the recording medium by the entire lens block moving means In this movement process, whether or not there is reflected light from the surface of the recording medium is defined as a first detection point, and whether or not there is reflected light from the signal surface of the recording medium is defined as a second detection point. Recording medium type determining means for determining the type of the recording medium from a detection signal based on light reflected from the medium.

According to a tenth aspect of the present invention, in the recording medium recording / reproducing apparatus according to the ninth aspect, the recording medium type discriminating means moves the all lens block bodies from a most remote position to a contact position. The moving speed of all the lens block bodies is set to be high until the first detection point is detected, and the moving speed of the all lens block bodies is set to be low after detecting the first detection point.

According to an eleventh aspect of the present invention, in the recording medium recording / reproducing apparatus according to the ninth aspect, when the second detection point is detected in the focus pull-in mode, the focus servo is locked from that point. It is characterized in that

According to a twelfth aspect of the present invention, in the recording medium recording and reproducing apparatus according to the ninth aspect, the recording medium type discriminating means moves the entire lens block from a contact position to a remotest position. Features.

According to a thirteenth aspect of the present invention, in the recording medium recording / reproducing apparatus according to any one of the ninth to twelfth aspects, a recording medium for detecting whether or not all the lens block members are in contact with the recording medium. It is characterized by having contact detecting means.

According to a fourteenth aspect of the present invention, in the recording medium recording / reproducing apparatus according to the thirteenth aspect, the recording medium contact detecting means is configured as an electromagnetic actuator in which the entire lens block body moving means comprises a magnet, a coil or the like. The electromagnetic actuator is characterized in that it is detected by applying a voltage that generates a disturbance to which the electromagnetic actuator can respond, and measuring the back electromotive force from the electromagnetic actuator at this time.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a configuration diagram of an optical pickup PA of a recording medium recording / reproducing apparatus according to one embodiment of the present invention. In FIG. 2, a semiconductor laser 300 generates a laser beam as a light beam, and this laser beam is
1. The light reaches the actuator section A via the diffraction grating 302 and the beam splitter 303, and forms an image on the signal surface of an optical disc D as a recording medium via the objective lens 304 and the auxiliary lens 305 of the actuator section A. The reflected light from the optical disk D is incident on the beam splitter 303 again via the auxiliary lens 305 and the objective lens 304, and a part of the p-polarized component and all of the s-polarized component are extracted and emitted to another beam splitter 306. Is done.

The other beam splitter 306 emits a part of the incident laser light to the lens 307, and emits the remaining most to the polarization beam splitter 309 via the half-wave plate 308. The polarization beam splitter 309 is
The incident laser light is separated into an s-polarized light component and a p-polarized light component, which are output to a lens 310 and a lens 311 respectively.

The laser light incident on the lens 307 is output to the photodiode 313 via the lens 312 that gives astigmatism to the beam. Photodiode 313
Converts the input laser light into an electric signal corresponding to the beam intensity, and outputs the electric signal to the servo head amplifier 333 shown in FIG. 3 as a servo signal.

The laser light emitted from the polarizing beam splitter 309 is incident on the photo-diode 316 and another photo-diode 317 via the lenses 310 and 314 and via the lenses 311 and 315, respectively. . Two photo die orders 316, 31
Numeral 7 converts the incident laser light into a corresponding electric signal, and the two electric signals are differentially amplified and output as a reflected light amount signal to the RF head amplifier 340 shown in FIG.

A part of the laser light emitted from the semiconductor laser 300 and incident on the beam splitter 303 via the collimator lens 301 and the diffraction grating 302 is reflected on the beam splitter 303 and transmitted to the photodiode 319 via the lens 318. Is output. Photodiode 319 converts the incident laser light into a corresponding electric signal, and this electric signal is supplied to an APC (Automatic Power Control) circuit (not shown). The APC circuit controls the power of the laser light emitted from the semiconductor laser 300 to be constant.

The magnetic head 320 shown in FIG.
The optical disk D is arranged on the opposite side of the actuator section A, and applies an external magnetic field according to recording information in a recording mode.

FIG. 1A is a schematic sectional view of the actuator section A of the optical pickup PA. In FIG. 1A, the objective lens holder 32 holding the objective lens 304
1 is supported by a base member 322 via a first support member (not shown) so as to be movable in a focus direction (optical axis direction) and a tracking direction (vertical direction in the optical axis direction).
An auxiliary lens holder 323 for holding the auxiliary lens 305 is supported by the objective lens holder 321 via a second support member (not shown) so as to be movable in a focus direction (optical axis direction). A sliding portion 324 is fixed to the optical disk D side of the auxiliary lens holder 323, and the sliding portion 324 is configured to contact the optical disk D before the auxiliary lens 305 and the like. The sliding portion 324 is made of a member excellent in shock absorption, and protects the auxiliary lens 305 and the optical disc D in the event of a collision.

The entire lens block LB1 including the objective lens holder 304 and the auxiliary lens holder 305 is
It is configured to be moved in a focus direction and a tracking direction by a focus / tracking actuator 325 that is a first moving unit. The focus / tracking actuator 325 is configured by an electromagnetic actuator including a magnet, a focus coil, a tracking coil, and the like. The auxiliary lens block body LB2 including the auxiliary lens holder 305
Auxiliary lens actuator 326 as a second moving means
It is configured to be moved in the focus direction. The auxiliary lens actuator 326 is configured by an electromagnetic actuator including a magnet, an auxiliary lens coil, and the like. By moving the auxiliary lens 305 in the focus direction, the distance between the auxiliary lens 305 and the objective lens 304 is changed.

FIG. 3 is a circuit block diagram of a recording medium recording / reproducing apparatus. In FIG. 3, the spindle motor 330
Rotates the optical disc D at a predetermined angular velocity by a drive signal of the motor drive circuit 331. The motor drive circuit 331 outputs a drive signal based on a motor control signal from the control unit 332. The optical pickup PA outputs a servo signal as described above, and this servo signal is supplied to the focus error signal generation circuit 334 and the tracking error signal generation circuit 335 via the servo head amplifier 333.

The focus error signal output from the focus error signal generation circuit 334 is
6, and the phase compensation circuit 336 performs phase compensation on the focus error signal. The tracking error signal output from the tracking error signal generation circuit 335 is supplied to a phase compensation circuit 337, and the phase compensation circuit 337 performs phase compensation on the tracking error signal. The signals output from the two phase compensation circuits 336 and 337 are supplied to the focus / tracking actuator 325 of the optical pickup PA via the amplifiers 338 and 339. More specifically, the focus error signal is supplied to the focusing coil, and the tracking error signal is supplied to the tracking coil, whereby each control of focusing and tracking is performed.

The amplifier 338 selects the output of the phase compensation circuit 336 as an input signal in a normal state (a state in which the focus servo is locked in). When the signal is output, a signal (focus control signal) from the control unit 332 is selected as an input signal.

The optical pickup PA outputs a reflected light quantity signal as described above, and this reflected light quantity signal is supplied to the control unit 332 via the RF head amplifier 340, and also supplied to a decoding circuit (not shown) to return to the original. The information is reproduced.

FIG. 4 is a detailed circuit block diagram of the control section 332. In FIG. 4, the RF head amplifier 34
The reflected light amount signal output from 0 is supplied to an LPF (low-pass filter) 342, and the output of the LPF 342 is handled as a first detection signal based on the reflected light of the optical disk D. This first detection signal is digitized by the A / D converter 343, and transmitted to the CPU 3 via the interface 344.
45.

A focus error signal is supplied to the control unit 332, and this focus error signal is handled as a second detection signal based on the reflected light of the optical disk D. This second detection signal is digitized by the A / D converter 346 and supplied to the CPU 345 via the interface 344.

The CPU 345 is constituted as a recording medium type determining means, and determines the type of the optical disk D in the recording medium type determining mode. That is, the first and second
The type of the optical disk D is determined based on the detection signal, and a control signal for the auxiliary lens is generated based on the determination result. The control signal for the auxiliary lens is output via the D / A converter 352. The auxiliary lens control signal is supplied to the auxiliary lens actuator 326 of the optical pickup PA via the amplifier 341 (shown in FIG. 3). More specifically, the control signal for the auxiliary lens is supplied to the coil for the auxiliary lens, thereby setting the distance between the objective lens 304 and the auxiliary lens 305. The procedure for generating the control signal for the auxiliary lens will be described in detail below.

The reflected light amount signal output from the RF head amplifier 340 is also supplied to the jitter detection circuit 347. The jitter detection circuit 347 includes an equalizer circuit, a PLL circuit, a clock data comparison circuit, and the like, and detects a jitter value of the reflected light amount signal. The jitter value signal is output from the A / D converter 3
The data is digitized at 48 and supplied to the CPU 345 via the interface 344.

In the focus pull-in processing mode, the CPU 345 generates an auxiliary lens control signal based on the jitter value signal, and outputs this auxiliary lens control signal via the D / A converter 352 in the same manner as described above. . Also, CPU
As described above, the focus control signal 345 outputs a focus control signal when the focus servo is pulled in. The focus control signal is output via the D / A converter 353.

The control unit 332 is supplied with a focus coil drive signal, a tracking coil drive signal, and an auxiliary lens coil drive signal. Each signal is digitized by each of the A / D converters 354, 355, and 356. CPU 345 via the interface 344
Supplied to The CPU 345 is configured as a recording medium contact detection unit, and detects whether or not the entire lens block body LB1 is in contact with the optical disc D by detecting the signal state.

The ROM 349 includes a recording medium type discrimination program having the contents shown in the flowchart of FIG. 5, a focus pull-in processing program having the contents shown in the flowchart of FIG. 6, a recording medium contact presence / absence determination program having the contents shown in the flowchart of FIG. Is stored. RAM 350
Changes the control program stored in the ROM 349 to C
It temporarily stores data and calculation results generated when the PU 345 executes. EEPROM as a memory
351 stores distance data between the objective lens 304 and the auxiliary lens 305 corresponding to various optical disks D.

The CPU 345 executes various control programs stored in the ROM 349, the details of which will be described below with reference to FIGS.

FIG. 8 shows that the distance L1 from the surface d1 of the optical disk D1 to the signal surface d2 is short (for example, the thickness of the substrate d0 is 0.1 mm), and the surface d1 of the optical disk D1 and the signal surface that can be recorded and reproduced by the recording / reproducing apparatus. FIG. 10 shows the focus position of the light beam with respect to d2. FIG. 10 shows that the entire lens block LB1 moves from the farthest position shown in FIG. 1B to the closest position shown in FIG. FIG. 7 is an output waveform diagram when the remote control returns to the farthest position shown in FIG.

8 and 10, when the optical disk D1 is approached from the farthest position and is located at the position a in FIG. 8, reflected light from the surface d1 is obtained, and further the optical disk D1 is approached and the optical disk D1 is located at the position b in FIG. Then, since the reflected light from the signal surface d2 is obtained, the reflected light amount signal and the focus error signal are obtained at different levels at these two positions.
When returning from the closest position to the farthest position, similar signals are obtained at the same positions b1 and a1.

FIG. 9 shows that the distance L2 from the surface d1 of the optical disk D2 to the signal surface d2 is long (for example, the thickness of the substrate d0 is 0.6 mm), and the light with respect to the surface d1 of the optical disk D2 that cannot be recorded / reproduced by the recording / reproducing apparatus. FIG. 11 shows the light beam condensing position and the light beam condensing position at the closest position. FIG. 11 shows a state in which the entire lens block LB1 moves from the most remote position to the closest position, and then returns to the most remote position again. It is each output waveform diagram.

9 and 11, when the optical disk D2 is approached from the farthest position and is located at the position c in FIG. 9, reflected light from the surface d1 is obtained. Even at the position, that is, at the contact position where the sliding portion 324 contacts the optical disc D, the reflected light from the signal surface d2 is not obtained, so that the reflected light amount signal and the focus error signal are obtained only at one position. .
At this time, in order to bring the sliding portion 324 into contact with the optical disc D, it is safe if only the auxiliary lens 305 is slightly moved in the contact direction at a position immediately before the contact. Note that when returning from the contact position to the farthest position, similar signals are obtained at the same positions d1 and c1.

When the optical disk D is not mounted, no signal is obtained because there is no reflective surface.

FIG. 5 is a flowchart in the recording medium type determination mode. In FIG. 5, all lens blocks L
B1 is located at the farthest position shown in FIG. 1B as an initial position. The CPU 345 detects whether or not the optical disc D is mounted on the recording medium recording / reproducing device (step S3).
1) When the optical disc D is loaded, the spindle motor 3
30 is confirmed to be stopped (step S2).

Next, the CPU 345 sets an initial value of zero to D1 and D2 of a built-in measured value storage register (not shown), for example (step S3), and controls the semiconductor laser 300 to output a laser beam. Further, the CPU 345 sets, for example, zero as data in an 8-bit counter (not shown) connected to the built-in D / A converter 353 (step S5). Focus data based on the data of this 8-bit counter (not shown) is output from the D / A converter 353 (step S6), and the focus / tracking actuator 32 is output by the focus control signal.
5 is driven to move all the lens block bodies LB1 in the focus direction. Here, the data of the 8-bit counter = zero corresponds to the farthest farthest position shown in FIG.
The data of the 8-bit counter = 255 corresponds to the closest position shown in FIG.

When the CPU 345 starts outputting the focus control signal, the focus error signal (first detection signal)
And output of the LPF 342 of the reflected light amount signal (second detection signal)
(Step S7), and it is checked whether the level of each detection signal exceeds each first threshold value or not, and whether it exceeds the second threshold value (Step S8, Step S8).
9). If the first and second thresholds are not exceeded, the data of the 8-bit counter is incremented by one (step S11). If the first threshold is exceeded, 1 is stored in the register D1 (step S11). Step S12). If each second threshold value is exceeded, 1 is stored in the register D2 (step S13), and the process proceeds to step. Also, when the data of the 8-bit counter reaches 255 without exceeding each of the first and second thresholds or without exceeding the second threshold, that is, the nearest position in FIG. If it is located at step (1), the process proceeds to step 14 (step S10).

In step 14, the values stored in the registers D1 and D2 are read, and if D1 = 1 and D2 = 1, it is determined that a predetermined optical disk D is present (step S1).
5, step S18), and shift to the next mode. D1 =
If D1 and D2 = 0, the optical disk D other than the predetermined
It is determined that there is, and information indicating that the disk should be replaced is displayed (steps S16 and S19). D1 = 0
If D2 = 0, it is determined that there is no optical disk D, and information for inserting a disk is displayed (steps S17 and S20).

In the above processing program, the signals of the reflected light on both the surface d1 and the signal surface d2 of the optical disk D are used,
Since the change in the reflected light at this point is clear, it is easy to make a distinction, and accurate distinction can be made.

In the above processing program, two signals are used as the detection signal, the focus error signal (first detection signal) and the output of the reflected light amount signal LPF342 (second detection signal), but only one signal is used. May be. However, it is preferable to use two signals as in this embodiment because the detection accuracy is improved.

In the above-mentioned processing program, the case where the type of the optical disk D is determined to be a predetermined disk, a non-predetermined disk, or no disk is described. To That is, a read-only disc, a write-once disc, a RAM disc, a single-layer disc, a dual-layer disc, and the like have almost the same level of reflected light from the surface and no difference, but have different levels of reflected light from the signal surface. Therefore, by making use of the fact that the reflectivity of the signal surface of each disc is different, the discrimination is made by setting the second threshold value in a plurality of stages. In order to improve the discrimination accuracy, the ratio between the signal level of the reflected light from the surface and the signal level of the reflected light from the signal surface is calculated, and discrimination is made from this ratio.

In the above processing program, all the lens block bodies LB1 are set to move from the most remote position to the closest position. Conversely, all the lens block bodies LB1 are set to move from the closest position to the most remote position. May be. With this setting, the discrimination time and the detection accuracy can be sometimes improved when the disk has large surface runout or variation. In particular, it is more effective to use the recording medium contact detection means described below.

FIG. 6 is a flowchart of the focus pull-in mode. In FIG. 6, desired distance data corresponding to the disc is read from the EEPROM 351 based on the discrimination result of the recording medium type discrimination (for example, a single-layer disc or a double-layer disc) (step 21), and the auxiliary lens for the auxiliary lens is read based on the distance data. A control signal is output to the auxiliary lens actuator 326 (step 22). Then, the auxiliary lens block body LB2 is moved by the driving force of the auxiliary lens actuator 326, and the distance between the auxiliary lens 305 and the objective lens 304 is adjusted to a predetermined distance. If it is only possible to determine whether the disc is a predetermined disc or not, this step is omitted.

Next, the CPU 345 outputs a focus control signal to move all the lens block bodies LB1 to the optical disc D.
(Step S23). The focus error signal (first detection signal) and the output of the LPF 342 (second detection signal) of the reflected light amount signal in this movement process are taken in (step S24). While decrementing the data one by one (step S2
6) Wait until the level of each detection signal exceeds the second threshold (step S25). The level of each detection signal is
If the threshold value is exceeded, the servo is immediately pulled in and the focus servo is locked in (step S27).

That is, since the focus / tracking actuator 325 is controlled and the focus servo is performed at the position where the laser beam is focused on the signal surface, immediately and
The optimal focus servo is applied reliably. If the distance between the auxiliary lens 305 and the objective lens 304 is not within a certain range, the spherical aberration may be so large that the focus carb cannot be pulled in. Is adjusted to a predetermined distance, the servo can be pulled in regardless of the type of the optical disc D, and the focus servo can be locked in.

Next, the CPU 345 outputs a control signal to the motor drive circuit 331 to output the control signal to the spindle motor 330.
The rotation of the spindle motor 330 is started (step S28), the rotation servo of the spindle motor 330 is locked in, and the tracking servo control is performed (step S29).

Next, the CPU 345 controls the jitter detection circuit 3
47 is set to a variable X1 for storing the detected jitter value,
Variable X that stores the jitter value read in the previous processing
Initially, 0 is set to 2 (step S30). Then, an auxiliary lens control signal is output to change the distance between the auxiliary lens 305 and the objective lens 304 (step S3).
1). Here, the movement of the auxiliary lens 305 divides the movable distance into 255 equal parts, and 0 to 25 in order from the farthest from the optical disk D.
The value of 5 corresponds. For example, if the current position is a value of 128, a control signal corresponding to a value of 127 or 129 is output, and a jitter value at this position is obtained. Then, the value of the previous variable X1 is substituted for the variable X2 (step S32),
The newly read jitter value is stored in the variable X1 (step S33).

Next, it is determined whether the value obtained by subtracting X2 from X1 is greater than 0, equal to, or smaller than 0 (step S34). The value obtained by subtracting X2 from X1 is 0
If it is determined to be smaller than (NO), step 31
And the same processing is repeated. If it is determined that the value obtained by subtracting X2 from X1 is greater than 0 or equal (YES), it means that the minimum value of the jitter value, that is, the best value of the signal quality has been obtained. Ends the processing. Here, in the first stage of the focus pull-in mode, the distance between the auxiliary lens 305 and the objective lens 304 is adjusted to a predetermined distance. However, since the distance slightly varies depending on the individual variation of the optical disc D, the spherical aberration is reduced. It can be adjusted to be small enough (less than Marechal's criterion). Further, the focus pull-in process is configured to be continuously performed following the recording medium type determination mode, but may be configured to be restarted separately.

FIG. 7 is a flowchart of the recording medium contact presence / absence determination mode. In FIG. 7, the recording medium contact detection means is an all-lens block body LB1, specifically, a sliding portion 3.
The CPU 345 applies a small vibration signal to the focus / tracking actuator 325 at a frequency within the servo band (step S35). And CPU3
45 captures the focus coil drive signal (step S36) and determines whether or not this signal level exceeds a threshold value (step S37). If the signal level exceeds the threshold, it is determined that there is no contact (step S38), and if the signal level does not exceed the threshold, it is determined that there is contact (step S39).

That is, for example, assuming that the focus crossing point is 2 KHz, the frequency at which the focus / tracking actuator 325 can respond is 500 Hz,
When a current of approximately 10 mA of a sine wave is applied to the coil, the constant of the back electromotive force of the focus / tracking actuator 325 is set to 10 mV / mA. When the coil is not in contact with the optical disc D, the signal of all the lens blocks LB1 is 500 Hz. Vibrates freely, 110 mV back electromotive force is generated in the focusing coil, and the back electromotive force exceeds the threshold value. When it is in contact with the optical disk D, it cannot vibrate freely, so that basically no back electromotive force is generated and the threshold value is not exceeded.

When it is desired to make a more accurate determination,
It is checked whether a sine wave synchronized with the applied sine wave is detected.

In the recording medium contact detecting means of this embodiment, the focus / tracking actuator 3
The presence or absence of contact can be detected only by measuring the back electromotive force of 25. Although the case where the excitation signal is applied to the focusing coil has been described, the presence or absence of contact can be similarly detected by applying the excitation signal to the tracking coil or the auxiliary lens coil.

Next, an application of the recording medium contact detecting means will be described. In the recording medium type determination mode,
The closest position of all the lens blocks LB1 is the optical disc D
Is set to be the contact position of all the lens block bodies LB
The information of the reflected light can be obtained over one movable wide range. That is, it is detected whether or not all the lens block members LB1 are in contact with the optical disc D. If the all lens block members LB1 are not in contact with the optical disk D for any reason, the gain of the amplifier is changed to move the all lens block members LB1. The information of the reflected light can be obtained by continuing the subsequent processing. If the air gap between all the lens block bodies LB1 and the optical disk D is very small (for example, about 75 μm), an error in the distance relationship between all the lens block bodies LB1 and the optical disk D in the stopped state, and the deviation of the optical disk D in the runout. If the state and other variations are included, the type may not be discriminated unless the optical disk D is brought into contact with the optical disk D. In such a case, the type can be accurately detected. As described above, the detection accuracy is improved by using the recording medium contact detection unit.

When all the lens block bodies LB1 are attracted to the optical disk D due to some abnormality, the abnormality can be detected, so that appropriate measures can be taken thereafter.

FIG. 12 is the first half of the flowchart in the recording medium type determination mode of the modification, and FIG. 13 is the second half of the flowchart in the recording medium type determination mode of the modification. FIG.
In FIG. 2 and FIG. 13, the description of the same parts as in the above embodiment is omitted, and only different parts will be described.

In the above-described embodiment, the speed of the focus / tracking actuator 325 is constant during the entire movement process. However, in this modification, the focus error signal (first detection signal) and the output of the LPF 342 of the reflected light amount signal (the second signal). 2), the data of the 8-bit counter connected to the D / A converter 353 is incremented by 2 until each level exceeds the first threshold (step S4).
9) Move at high speed (double speed). The speed may be 3 times or more.

Each level of the first and second detection signals is the first level.
When the threshold value is exceeded, the data of the 8-bit counter becomes 1
It is incremented by one at a time (step S55), and moved at a slow speed (1x speed). By varying the speed in this way, the overall movement time, that is, the determination time can be reduced, and the impact upon collision with the optical disk D can be reduced to half.

FIGS. 14A to 14E show another embodiment of the present invention. In the above embodiment, only the auxiliary lens 305 is movable independently of the objective lens 304. In the embodiment of the present invention, the auxiliary lens 305 itself cannot be moved independently and independently, but is moved only together with the objective lens 304. That is, this is a case where the auxiliary lens 304 is fixed.

FIG. 14A is a schematic sectional view of the actuator section A of the optical pickup PA. 14A, the objective lens holder 321 holds not only the objective lens 304 but also the auxiliary lens 305, and the objective lens holder 321 is attached to the base member 322 via a support member (not shown) in the focusing direction (not shown). It is movably supported in the optical axis direction) and the tracking direction (vertical direction of the optical axis direction). A sliding section 324 is fixed to the optical disc D side of the objective lens holder 321, and the sliding section 324 is configured to contact the optical disc D before the auxiliary lens 305 and the like. The sliding portion 324 is made of a member excellent in shock absorption, and protects the auxiliary lens 305 and the optical disc D in the event of a collision.

The entire lens block LB1 including the objective lens holder 321 and the like is provided with a focus / tracking actuator 3 serving as an all lens block moving means.
It is configured to be moved in the focus direction and the tracking direction by the reference numeral 25. The focus / tracking actuator 325 is configured by an electromagnetic actuator including a magnet, a focus coil, a tracking coil, and the like. FIG. 14B is a partial schematic view of the entire lens block LB1 at the farthest position, and FIG.
FIG. 14C is a partial schematic view of the entire lens block LB1 at a position where the light beam is condensed on the surface, and FIG. 14D is a part of the entire lens block LB1 at a position where the light beam is condensed on the signal surface. FIG. 14E is a schematic view of a part of the entire lens block body LB1 at the contact position.

The operation in the recording medium type discriminating mode will be described with reference to FIGS. 14B to 14E. However, since the operation is substantially the same as that of the above embodiment, it will be briefly described.

The recording medium recording / reproducing apparatus has a recording medium type discriminating means as in the above-described embodiment. The recording medium type discriminating means drives the focus / tracking actuator 325 to move the entire lens block LB1 as shown in FIG.
It is moved between the farthest position (b) and the contact position shown in FIG. 14 (e), and a first detection point determines whether or not there is light reflected from the surface d1 of the optical disc D as a recording medium in this movement process. The position based on the reflected light from the optical disc D is set as a second detection point (the position shown in FIG. 14D) as to whether or not there is reflected light from the signal surface d2 of the optical disc D. The type of the optical disc D is determined from the signal. Therefore, as in the case of the above-described embodiment, the type of the optical disc D can be accurately detected, focus servo is not performed due to misidentification of the type of the optical disc D, and the tip of the entire lens block body LB1 is attached to the optical disc D. The occurrence of a collision accident can be prevented. Optical disk D
Using the signals of the reflected light on both the surface d1 and the signal surface d2, the change in the reflected light at this point is clear,
It is easy to determine and more accurate determination can be made.

Further, the recording medium type discriminating means moves the entire lens block LB1 from the most remote position to the contact position, and moves the entire lens block LB1 until the first detection point is detected. And the moving speed of all the lens block bodies LB1 is set to be low after the first detection point is detected. With this setting, the discrimination time can be shortened and the impact at the time of collision with the optical disc D can be halved, as in the case of the above embodiment.

Here, when the second detection point is detected, the focus servo is locked in from that point. With this configuration, the focus servo is performed at the position where the laser light is focused on the signal surface d2, as in the case of the above-described embodiment, so that the optimal focus servo is immediately and reliably performed.

On the other hand, the recording medium type discriminating means may be configured to move the all lens blocks LB1 from the contact position to the farthest position. With such a configuration, as in the case of the above-described embodiment, when the surface deviation or variation of the optical disc D as the recording medium is large,
In some cases, the determination time and the detection accuracy can be improved.

Further, the recording medium recording / reproducing apparatus has a recording medium contact detecting means for detecting whether or not the all lens blocks LB1 are in contact with the optical disk D. With this recording medium contact detection means, in an apparatus having a small air gap between all the lens block bodies LB1 and the optical disk D in the recording / reproducing state, the type can be accurately determined even if there is an error or the like.

The recording medium contact detection means detects whether or not the entire lens block LB1, specifically, the sliding portion 324, is in contact with the optical disk D. The recording medium contact detection means is constituted by the electromagnetic actuator, which is, for example, a focus / tracking actuator 325, and applies a voltage that generates a disturbance to which the electromagnetic actuator can respond. It is detected by measuring the electromotive force. According to this configuration, as in the case of the above-described embodiment, the presence or absence of contact can be detected only by measuring the back electromotive force from the electromagnetic actuator.

Next, a description will be given of the configuration of the optical disc D most suitable for an apparatus in which the tip portions of the all-lens block body LB1 intentionally come into contact with each other or have a high possibility of contact. Substrate thickness is 0.1
mm polycarbonate, acrylic, polyolefin,
A signal surface is formed behind a resin layer such as epoxy or a glass layer. The entire diameter is 120 mm, and the inner peripheral portion up to a radius of 22 mm is a clamp area such as a clamp, and a radius of 24 mm.
The area from 20 mm to 58 mm is the data area, and the radius between the clamp area and the data area is about 20 mm to 30 mm (partially overlapped) as a protection area. This protection area contains a urethane-based bond of an ultraviolet curable resin as a protection layer. A polyfunctional acrylate is applied, and a silicone oil or polydimethylsiloxane-based lubricant is applied by spin coating or the like to a thickness of about 2 nm to 10 nm. Further, the lubricant layer may be composed of a thin diamond-like carbon or a carbon layer that transmits laser light. Alternatively, the disk substrate itself may be used as the protective layer, and only the lubricant layer may be formed on this surface. Further, the protective layer may be provided over the entire data area.

Then, the entire lens block LB1 is moved with respect to the position of the protection area. By doing so, it is possible to minimize the damage at the time of collision as much as possible and to keep it within a safe range.

[0083]

As described above, according to the first aspect of the present invention, there is provided an all-lens block body which has an objective lens and an auxiliary lens, and which converges a light beam on a recording medium with this two-group lens structure. A first moving means for moving the entire lens block body in the focus direction, a second moving means for varying a relative distance between the objective lens and the auxiliary lens, and the first moving means for moving the entire lens block body. Moving between a closest position closest to the recording medium and a farthest position farthest from the recording medium, and determining whether there is light reflected from the surface of the recording medium in the moving process at a first detection point. And determining whether or not there is reflected light from the signal surface of the recording medium as a second detection point to determine the type of the recording medium from a detection signal based on the reflected light from the recording medium. Since a body type determination unit can accurately detect the type of the recording medium. Therefore, it is possible to prevent the focus servo from being applied due to misidentification of the type of the recording medium, and to prevent the occurrence of an accident in which the front ends of all the lens block bodies collide with the recording medium, and the change in reflected light is clear. It is easy to determine and more accurate determination can be made.

According to a second aspect of the present invention, in the recording medium recording / reproducing apparatus according to the first aspect, the recording medium type discriminating means moves the entire lens block from the most remote position to the closest position. The moving speed of all the lens block bodies is set to be high until the first detection point is detected, and the moving speed of the all lens block bodies is set to be low after detecting the first detection point. In addition to the effects of the first aspect, it is possible to reduce the discrimination time and reduce the impact at the time of collision with the recording medium to half.

According to a third aspect of the present invention, in the recording medium recording and reproducing apparatus according to the first aspect, when the second detection point is detected, the focus servo is locked in from that point. Therefore, in addition to the effect of the first aspect of the present invention, since the focus servo is applied at the position where the laser beam is condensed on the signal surface, the optimum focus servo is immediately and surely performed.

According to a fourth aspect of the present invention, in the recording medium recording / reproducing apparatus according to the first aspect, the recording medium type discriminating means moves the all lens block bodies from the closest position to the farthest position. With such a configuration, in addition to the effects of the first aspect of the present invention, the discrimination time and the detection accuracy may be improved in the case where the surface fluctuation or variation of the recording medium is large.

According to the fifth aspect of the present invention, the first to fifth aspects are described.
The recording medium recording / reproducing apparatus according to claim 4, wherein
A memory storing distance data between the objective lens and the auxiliary lens corresponding to various recording media; reading desired distance data from the memory based on a result of the determination by the recording medium type determining means; Since the distance between the objective lens and the auxiliary lens was set based on
In addition to the effects of the first to fourth aspects of the present invention, servo pull-in is easily performed regardless of the type of recording medium, and the focus servo can be locked in.

According to the sixth aspect of the present invention, the first to fifth aspects are described.
The recording medium recording / reproducing apparatus according to claim 5,
Since the closest position is a position where the entire lens block comes into contact with the recording medium, in addition to the effects of the first to fifth aspects, the entire lens block can be moved over a wide range. To obtain information on the reflected light.

According to the seventh aspect of the present invention, the first to fifth aspects are described.
The recording medium recording / reproducing apparatus according to claim 6,
Since it has a recording medium contact detection means for detecting whether or not the all lens blocks are in contact with the recording medium,
In addition to the effects of the first to sixth aspects of the present invention, in an apparatus having a small air gap between all the lens block bodies and the recording medium in the recording / reproducing state, it is possible to accurately determine the type even if there is an error or the like. You.

According to an eighth aspect of the present invention, in the recording medium recording / reproducing apparatus according to the seventh aspect, the recording medium contact detecting means is such that at least one of the first moving means and the second moving means is a magnet. It is configured as an electromagnetic actuator composed of a coil and the like, and the voltage is applied such that a disturbance that this electromagnetic actuator can respond to is generated, and the voltage is detected by measuring the back electromotive force from the electromagnetic actuator at this time. In addition to the effect of the seventh aspect, the presence or absence of contact can be detected only by measuring the back electromotive force from the electromagnetic actuator.

According to the ninth aspect of the present invention, an all-lens block body having an objective lens and an auxiliary lens for condensing a light beam on a recording medium with this two-group lens structure, and focusing on this all-lens block body All lens block moving means for moving in the direction, the entire lens block is moved by the all lens block moving means between a contact position where it is brought into contact with the recording medium and a farthest position farthest from the recording medium. The first detection point determines whether or not there is reflected light from the surface of the recording medium in the moving process, and the second detection point indicates whether or not there is reflected light from the signal surface of the recording medium. A recording medium type discriminating means for discriminating the type of the recording medium from a detection signal based on the reflected light from the recording medium, so that the type of the recording medium can be accurately detected. Therefore, it is possible to prevent the focus servo from being applied due to misidentification of the type of the recording medium, and to prevent the occurrence of an accident in which the front ends of all the lens block bodies collide with the recording medium, and the change in reflected light is clear. It is easy to determine, and more accurate determination can be made.

According to the tenth aspect, the ninth aspect is provided.
In the recording medium recording / reproducing apparatus according to the above, the recording medium type determining means moves the all lens block bodies from the most remote position to the contact position, and until the first detection point is detected, the all lens block bodies. Since the moving speed of all the lens block bodies is set to be slow after detecting the first detection point, the discrimination time can be reduced in addition to the effect of the ninth invention, and The impact at the time of collision with the recording medium can be halved.

According to the eleventh aspect, the ninth aspect is provided.
In the recording medium recording / reproducing apparatus described in the above item, when the second detection point is detected, the focus servo is locked in from that point in time. Immediately and because the focus servo is applied at the position focused on the signal surface
The optimal focus servo is applied reliably.

According to the twelfth aspect, the ninth aspect is provided.
In the recording medium recording / reproducing apparatus according to the above, since the recording medium type discriminating means is configured to move the entire lens block from the contact position to the remotest position, in addition to the effect of the ninth aspect, In some cases, such as when the recording medium has large surface runout or variation, the discrimination time and the detection accuracy can be improved.

According to the thirteenth aspect, the ninth aspect is provided.
13. The recording medium recording / reproducing apparatus according to claim 12, further comprising a recording medium contact detection unit for detecting whether or not all of the lens blocks are in contact with the recording medium. In addition to the effects of the invention of Item 12, in an apparatus having a small air gap between all the lens block bodies and the recording medium in the recording / reproducing state, the type can be accurately determined even if there is an error or the like.

According to the fourteenth aspect, the first aspect is provided.
3. In the recording medium recording / reproducing apparatus according to 3, the recording medium contact detection means is configured such that the all-lens block moving means is configured as an electromagnetic actuator including a magnet, a coil, and the like, and a disturbance to which the electromagnetic actuator can respond is generated. Since such a voltage is applied and the back electromotive force from the electromagnetic actuator at this time is measured and detected, in addition to the effect of the invention of claim 13, it is only necessary to measure the back electromotive force from the electromagnetic actuator. The presence or absence of contact can be detected.

[Brief description of the drawings]

1A is a schematic cross-sectional view of an actuator section of an optical pickup according to an embodiment of the present invention, FIG. 1B is a schematic view of an auxiliary lens block at a farthest position, and FIG. (D) is a schematic view of the auxiliary lens block body at a position where the light beam is condensed on the signal surface, and (e) is an auxiliary view of the closest position (contact position). It is the schematic of a lens block body.

FIG. 2 is a configuration diagram of an optical pickup of the recording medium recording / reproducing apparatus according to one embodiment of the present invention.

FIG. 3 is a circuit block diagram of a recording medium recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 4 is a detailed circuit block diagram of a control unit.

FIG. 5 is a flowchart of a recording medium type determination mode.

FIG. 6 is a flowchart of a focus pull-in mode.

FIG. 7 is a flowchart of a recording medium contact presence / absence determination mode.

FIG. 8 is a diagram showing a light beam condensing state on a surface and a signal surface of an optical disc on which recording and reproduction can be performed by the recording and reproduction apparatus.

FIG. 9 is a diagram showing a light beam condensing state on a surface of an optical disc on which recording and reproduction cannot be performed by the recording / reproducing apparatus and a light beam condensing state at a contact position.

FIG. 10 is a waveform diagram of each output of an optical disc that can be recorded and reproduced by the recording and reproducing apparatus.

FIG. 11 is a waveform diagram of each output of an optical disc that cannot be recorded / reproduced by the recording / reproducing apparatus.

FIG. 12 is a first half of a flowchart in a recording medium type determination mode of a modified example.

FIG. 13 is a second half of a flowchart in a recording medium type determination mode of a modified example.

14A is a schematic cross-sectional view of an actuator section of an optical pickup, FIG. 14B is a partial schematic view of the entire lens block body at the farthest position, and FIG. (D) is a partial schematic view of the entire lens block body at a position where the light beam is focused on the signal surface, and (e) is a partial schematic view of the entire lens block body at a contact position. FIG.

[Explanation of symbols]

304 Objective lens 305 Auxiliary lens 321 Objective lens holder 325 Focus / tracking actuator (first moving means) 326 Auxiliary lens actuator (second moving means) 351 Memory LB1 All lens block body D Optical disk (recording medium) d1 Surface of optical disk d2 Signal surface of optical disk

Claims (14)

[Claims] 1. An all-lens block body having an objective lens and an auxiliary lens for converging a light beam on a recording medium in a two-group lens configuration, and a first movement for moving the all-lens block body in a focus direction. Means, a second moving means for changing a relative distance between the objective lens and the auxiliary lens, and the first moving means,
It is moved between a closest position closest to the recording medium and a farthest position sufficiently away from the recording medium, and a first detection point is used to determine whether or not there is light reflected from the surface of the recording medium in the moving process. And a recording medium type discriminating means for discriminating the type of the recording medium from a detection signal based on the reflected light from the recording medium with the presence or absence of reflected light from the signal surface of the recording medium as a second detection point. A recording medium recording / reproducing apparatus comprising: 2. The recording medium recording / reproducing apparatus according to claim 1, wherein said recording medium type discriminating means moves said all lens block bodies from a most remote position to a closest position, and said first detection point. Wherein the moving speed of all the lens block bodies is set to be high until the detection of the first detection point, and the moving speed of the all lens block bodies is set to be low after detecting the first detection point. 3. The recording medium recording / reproducing apparatus according to claim 1, wherein in a focus pull-in mode, when the second detection point is detected, the focus servo is locked in from that point. Recording medium reproducing apparatus. 4. The recording medium recording / reproducing apparatus according to claim 1, wherein said recording medium type discriminating means moves said all lens block bodies from a closest position to a farthest position. Medium recording and playback device. 5. The recording medium recording / reproducing apparatus according to claim 1, further comprising a memory storing distance data between the objective lens and the auxiliary lens corresponding to various recording media. A desired distance data is read from the memory based on the determination result of the medium type determining means, and a distance between the objective lens and the auxiliary lens is set based on the distance data. apparatus. 6. The recording medium recording / reproducing apparatus according to claim 1, wherein the closest position is a position where the entire lens block comes into contact with the recording medium. Recording medium recording / reproducing device. 7. The recording medium recording / reproducing apparatus according to claim 1, further comprising: a recording medium contact detection unit that detects whether or not all of the lens blocks are in contact with the recording medium. A recording medium recording / reproducing apparatus characterized by the above-mentioned. 8. The recording medium recording / reproducing apparatus according to claim 7, wherein the recording medium contact detecting means is an electromagnetic actuator in which at least one of the first moving means and the second moving means comprises a magnet, a coil, or the like. A recording medium recording / reproducing apparatus characterized in that the voltage is applied such that a disturbance to which the electromagnetic actuator can respond is generated, and the back electromotive force from the electromagnetic actuator at this time is measured. . 9. An all-lens block body having an objective lens and an auxiliary lens, and converging a light beam on a recording medium in a two-lens configuration, and an all-lens block for moving this all-lens block body in a focus direction. Body moving means, and the entire lens block body is moved by the all lens block body moving means between a contact position where the lens block body is brought into contact with the recording medium and a farthest position sufficiently away from the recording medium. The first detection point is whether or not there is reflected light from the surface of the recording medium, and the second detection point is whether or not there is reflected light from the signal surface of the recording medium. And a recording medium type discriminating means for discriminating the type of the recording medium from a detection signal based on the recording medium. 10. The recording medium recording / reproducing apparatus according to claim 9, wherein said recording medium type discriminating means moves said all lens block bodies from a most remote position to a contact position, and sets said first detection point to said first detection point. A recording medium recording / reproducing apparatus, wherein the moving speed of all the lens block bodies is set to be high until the detection is performed, and the moving speed of the all lens block bodies is set to be low after detecting the first detection point. 11. The recording medium recording / reproducing apparatus according to claim 9, wherein in the focus pull-in mode, when the second detection point is detected, the focus servo is locked in from that point. Recording medium reproducing apparatus. 12. The recording medium recording and reproducing apparatus according to claim 9, wherein said recording medium type discriminating means moves the entire lens block from a contact position to a remotest position. Recording and playback device. 13. The recording medium recording / reproducing apparatus according to claim 9, further comprising: a recording medium contact detection unit that detects whether or not all of the lens blocks are in contact with the recording medium. A recording medium recording / reproducing apparatus characterized by the above-mentioned. 14. The recording medium recording / reproducing apparatus according to claim 13, wherein said recording medium contact detection means is configured such that said all-lens block body moving means is constituted by an electromagnetic actuator comprising a magnet, a coil and the like. A recording medium recording / reproducing apparatus characterized in that the voltage is applied such that a disturbance capable of responding is generated, and the back electromotive force from the electromagnetic actuator at this time is measured and detected.