JP4339747B2 - Optical recording / reproducing device - Google Patents

Description

The present invention relates to an optical recording / reproducing apparatus, and more particularly to an optical recording / reproducing apparatus characterized by a focus control portion for a three-dimensional optical recording medium.

  In recent years, there is a three-dimensional optical recording medium as one of the promising next-generation ultra-high density optical recording media such as optical disks.

  While the conventional optical recording medium records information two-dimensionally on the recording layer, the above-described three-dimensional optical recording medium has a recording layer having a film thickness larger than the focal depth of the laser used. In addition to recording in dimension (planar), information is also recorded in the depth direction of the layer. For example, if 100 layers are recorded in the depth direction, the current recording density can easily be 100 times the current density. can do.

  Such research reports on three-dimensional optical recording media are not intended for recording / reproduction of the recording media in the disk state, but for example, the Opinion Symposium Kyoto '92 Lecture Proceedings P39-40 and the 40th Applied Physics It is disclosed in the academic related joint proceedings 29p-B-11, 29p-B-12.

  Further, for example, Japanese Patent Laid-Open Nos. 5-101398 and 7-21565 have proposed devices for recording and reproducing information on a three-dimensional optical recording medium by performing focus servo and tracking servo.

  In the above Japanese Patent Laid-Open No. 5-101398, a known front-rear differential focal point is obtained by moving an objective lens in a layer direction with respect to a three-dimensional optical recording medium provided with a ROM (Read Only Memorey) layer or a WO (Wright Once) layer. The recording / reproducing beam is focused on a desired recording layer by the deviation detection method, and the medium information pre-recorded in the ROM layer or the data state of each layer written in the WO layer is read to manage the data.

  In the above-mentioned Japanese Patent Application Laid-Open No. 7-21565, an objective lens that has a plurality of laser generating means and a plurality of light detecting means and focuses laser light on a three-dimensional optical recording medium is the base of the plurality of recording layers. The guide layer is moved with reference to the guide surface, and the focusing of each laser beam on the plurality of recording layers is performed by moving collimator lenses provided in the plurality of light detection means.

  However, since the focus on the reference layer is not maintained in the above Japanese Patent Laid-Open No. 5-101398, access to the ROM layer, the WO layer, or the desired recording layer is performed by moving the objective lens each time. There is a problem that focus pull-in and layer information provided in each layer must be read, and it takes time to access a desired recording layer.

  Japanese Patent Laid-Open No. 7-21565 discloses that a guide surface of a guide layer serving as a base of a plurality of recording layers is used as a reference, but does not disclose any control sequence such as a focus servo. For example, the beam is incident on the three-dimensional optical recording medium through both the focus adjustment optical system that can be moved by the focus adjustment actuator and the objective lens that can be moved by the objective lens actuator. Otherwise, there is a problem that stable pull-in control cannot be performed.

  The present invention has been made in view of the circumstances described above, and is an optical recording that can quickly perform an initial operation on a three-dimensional optical recording medium and can reliably access a desired recording layer at a high speed with a recording / reproducing beam. The object is to provide a playback device.

The first optical recording / reproducing apparatus of the present invention includes an optical disc having a plurality of recording layers for recording information and a servo layer in which the recording conditions of the recording layer are recorded in advance, and the optical disc is rotated at a predetermined prescribed rotational speed. A disc rotating means for rotating the optical disc, and an objective lens and a first collimator lens for focusing the servo beam on the servo layer until the rotational speed of the optical disk reaches a predetermined rotational speed slower than the predetermined specified rotational speed and the servo focus control means having bets, the starts more operations to control operation of the servo focus control means, for focusing the recording beam on the recording layer, the objective lens and the second collimating lens recording and reproducing focusing control means, said second of said lens holder is attached to the optical element of the collimator lens second collimator having bets Comprising means for detecting the position of the lens optically, a position detection control means for said second collimator lens is controlled by detecting the position moves in the optical axis direction with respect to a predetermined reference value, for the recording The recording / reproducing focus control means is controlled to focus the beam on a predetermined recording layer that is predetermined as a reference layer when moving the objective lens relative to each recording layer among the plurality of recording layers. Recording / reproducing beam control means for controlling the movement of the second collimator lens based on the output of the predetermined reference value, and using the recording / reproducing beam as a reference layer to determine a predetermined value; after allowed to crude moved to the vicinity of the recording layer, further by performing the focus search and focus control of the recording and reproducing beam pre the recording and reproducing beam as the reference layer Recording and reproducing beam control means for controlling said recording and reproducing focus control means a predetermined recording layer focuses manner which is determined, characterized by comprising a.

According to a second optical recording / reproducing apparatus of the present invention, in the first optical recording / reproducing apparatus, the optically detecting means includes a light emitting element and a light receiving element.

  According to the present invention, the servo focus control means and the recording / playback focus control means are provided, and the servo beam is combined with the servo layer until the rotation speed of the optical disk reaches a predetermined rotation speed slower than the specified rotation speed. Since the focusing is performed, the initial operation can be accelerated with respect to the three-dimensional optical recording medium, and the desired recording layer can be accessed at high speed and reliably.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 to 11 relate to an embodiment of the present invention, FIG. 1 is a block diagram showing the configuration of an optical system of an optical recording / reproducing apparatus, and FIG. 2 is a three-dimensional optical recording used in the optical recording / reproducing apparatus of FIG. 3 is a block diagram showing the configuration of the servo layer and the recording layer in FIG. 2, FIG. 4 is a block diagram showing the configuration of the collimator lens moving unit in FIG. 1, and FIG. 4 is a block diagram showing the configuration of the third detector of FIG. 4, FIG. 6 is a block diagram showing the configuration of the first modification of the third detector of FIG. 4, and FIG. 7 is a second diagram of the third detector of FIG. FIG. 8 is an explanatory diagram for explaining the operation of the collimator lens moving unit in FIG. 4, FIG. 9 is a first flowchart for explaining the operation of the optical recording / reproducing apparatus in FIG. 1, and FIG. 2 is a second flowchart for explaining the operation of the optical recording / reproducing apparatus in FIG. 1, and FIG. 11 is an operation of the optical recording / reproducing apparatus in FIG. It is an explanatory diagram explain.

  As shown in FIG. 2, an optical disc 1 that is a three-dimensional optical recording medium used in this embodiment includes a servo layer 3 formed of a ROM layer or a WO layer provided on a substrate 2, and a servo layer 3 on the servo layer 3. The servo layer 3 and each recording layer 4 are managed by tracks and sectors as shown in FIG. 3. The recording layer 4 is composed of a plurality of n layers (first layer to n-th layer). The information recorded on the optical disk 1 is addressed by layer number: k, track number: l, sector number: m, and is recorded and reproduced by accessing a desired area with a recording / reproducing beam. .

  When the servo layer 3 is a ROM layer, for example, management data such as servo tracks and recording / reproduction conditions of each recording layer 4 is preformatted. When the servo layer 3 is a WO layer, the recording power that varies depending on the temperature and tilt conditions at the time of ejection, in addition to the preformatted management data such as the servo track and recording / reproducing conditions of each recording layer 4 It is possible to record conditions.

  The recording / reproducing conditions of each recording layer 4 include the recording / reproducing beam irradiation conditions corresponding to each recording layer 4 because the transmittance of the recording / reproducing beam changes according to the depth in the layer direction. The recording power condition includes the adjusted recording power and the like because the recording power is adjusted in the initial processing as will be described later because the semiconductor laser emitting the recording / reproducing beam has temperature dependency.

  As shown in FIG. 1, in the optical recording / reproducing apparatus 11 of the present embodiment, when a cartridge 12 with the optical disk 1 configured as described above is inserted into the apparatus, a predetermined position is set by a loading mechanism (not shown). The cartridge 12 is disposed on the surface. The cartridge 12 loaded at a predetermined position is detected by the cartridge detector 13, and this detection signal is output to the control circuit 14.

  The control circuit 14 includes a ROM 15 in which a control program is stored and a CPU 16 that performs processing according to the control program. Upon receiving a detection signal from the cartridge detector 13, the control circuit 14 controls the drive circuit 17 to control the spindle motor. 18 is driven to rotate the optical disc 1 at a predetermined prescribed rotational speed at the time of recording and reproducing information.

  The optical pickup 20 includes a moving optical system 20a and a fixed optical system 20b. In the fixed optical system 20b, a servo beam applied to the servo layer 3 of the optical disk 1 is emitted from the first light source 19, and this servo beam is emitted. Is irradiated to the servo layer 3 of the optical disc 1 by the moving optical system 20a movable in the radial direction of the optical disc 1 through the first collimator lens 19a.

  Further, the moving optical system 20a of the optical pickup 20 includes an inclination detector including a detection light source 21 that emits inclination detection light for detecting the inclination of the optical disc 1 and a light receiving element 22 that receives return light of the inclination detection light. The inclination detector 23 detects the inclination of the optical disk from the spot shape of the return light of the inclination detection light, and outputs a detection signal to the control circuit 14.

  The control circuit 14 calculates tilt information from this detection signal, and when there is an abnormality in the tilt of the optical disc 1 based on the tilt information, a predetermined error process is performed to eject the cartridge 3 from the apparatus. .

  Further, the moving optical system 20a of the optical pickup 20 reflects the servo beam from the first light source 19 via the first collimator lens 19a perpendicularly to the optical disc 1 (direction perpendicular to the radial direction) 25. An objective lens 26 for converging the servo beam reflected by the wavelength-dependent mirror 25 via the quarter-wave plate 25a, and for focusing the focused servo beam on the servo layer 3 An objective lens actuator 27 that moves the objective lens 26 back and forth in the optical axis direction is provided. The objective lens 26 and the objective lens actuator 27 constitute an objective optical system.

  The wavelength-dependent mirror 25 has an optical characteristic in which a deflection angle is different depending on a light beam having a different wavelength from an incident polarization direction. Specifically, a beam synthesis and a prism emission surface ( A polarization-dependent hologram is formed on the quarter-wave plate 25a side).

  Return light of the servo beam from the optical disk 1 passes through the first collimator lens 19a in the fixed optical system 20b via the objective lens 26 and the wavelength-dependent mirror 25 in the moving optical system 20a, and the first photodetector 28. Is detected.

  In the fixed optical system 20b, the first optical detector 28 performs a servo focus error signal indicating the focus state of the servo beam on the servo layer 3 from the return light of the servo beam and a tracking error for positioning on the track. Output a signal.

  The servo focus error signal and tracking error signal are output to the position detection Fo / Tr control circuit 24, and the position detection Fo / Tr control circuit 24 generates focus information and track information. Information is output.

  The control circuit 14 controls the drive circuit 17 based on the focus information to drive the objective lens actuator 27 in the moving optical system 20a to move the objective lens 26 forward and backward to focus the servo beam on the servo layer 3, and The servo beam is held in a desired track based on the track information.

  By controlling the objective lens actuator 27 based on the servo focus error signal, the objective lens 26 always maintains the focused state of the servo beam on the servo layer 3.

  The recording / reproducing beam irradiated on the desired recording layer 4 of the optical disc 1 is emitted from the second light source 29 in the fixed optical system 20 b, and this recording / reproducing beam moves through the second collimator lens 30. The desired recording layer 4 of the optical disk 1 is irradiated through the wavelength-dependent mirror 25 and the objective lens 26 by the optical system 20a.

  In the moving optical system 20a, as described above, the objective lens 26 is controlled so as to always maintain the focus state of the servo beam on the servo layer 3, so that the fixed optical system 20b includes the desired recording layer 4. In order to focus the recording / reproducing beam, a collimator lens moving unit 31 for moving the second collimator lens 30 back and forth in the optical axis direction of the recording / reproducing beam is provided. Details of the collimator lens moving unit 31 will be described later.

  Return light from the optical disc 1 of the recording / reproducing beam passes through the objective lens 26 and the wavelength-dependent mirror 25 in the moving optical system 20a, passes through the second collimator lens 30 in the fixed optical system 20b, and passes through the pinhole 32. Is detected by the second photodetector 33.

  In the second photodetector 33, a recording / reproducing focus error signal indicating the focus state of the recording / reproducing beam on the desired recording layer 4 and a tracking error signal for positioning to the track are obtained from the return light of the recording / reproducing beam. Output. The recording / playback focus error signal and tracking error signal are output to the position detection Fo / Tr control circuit 24, and the position detection Fo / Tr control circuit 24 generates focus information and track information. Track information is output.

  The control circuit 14 controls the drive circuit 17 based on the focus information to drive the collimator lens moving unit 31 to move the second collimator lens 30 forward and backward to focus the recording / reproducing beam on the desired recording layer 4, and The recording / reproducing beam is held in a desired track based on the track information.

  Although the optical pickup 20 is configured in a state where the moving optical system 20a and the fixed optical system 20b are separated, the members (elements) of the moving optical system 20a and the fixed optical system 20b are integrally configured. The optical pickup may be movable as a whole in the radial direction of the optical disc 1.

  The control circuit 14 adjusts the recording / reproducing beam of the second light source 29 based on the detection signal from the temperature sensor 34 to provide an appropriate recording power. It is supposed to be set.

  As shown in FIG. 4, the collimator lens moving unit 31 irradiates the optical wedge 42 with the optical wedge 42 fixed to the holder 41 holding the second collimator lens 30 and the pinhole 43. A third light source (for example, a light emitting diode LED) 44, a third detector 45 for detecting a spot light 48 of the light beam from the third light source 44 whose optical path has been changed by the optical wedge 42, and a second collimator by the drive circuit 17. A collimator lens actuator 46 that drives the optical wedge 42 forward and backward together with the lens 30, and an LED light control circuit 47 that controls the light emission power of the third light source 45 to a constant power based on the detection signal of the third detector 45.

  As shown in FIG. 5, the third detector 45 includes three light receiving detection areas, that is, a first light receiving detection area 45a, a second light receiving detection area 45b, and a third light receiving detection area 45c. In addition, not only the 3rd detector 45 but you may comprise by the light reception detection area | region as shown in FIG. 6 or FIG. 7, and you may comprise by PSD (position sensor device).

  As shown in FIG. 5, the spot light 48 of the light beam from the third light source 44 is driven by the optical wedge 42 by the collimator lens actuator 46 so as to advance and retreat. It moves on the detection area 45c.

  The LED light control circuit 47 photoelectrically converts the spot light 48 of the light beam from the third light source 44 in the first light receiving detection area 45a, the second light receiving detection area 45b, and the third light receiving detection area 45c, and uses the LED light as a detection signal. The LED light control circuit 47 outputs to the control circuit 47, adds the three detection signals, and controls the light emission power of the third light source 44 so that the addition signal becomes constant.

  The three detection signals are also output to the position detection Fo / Tr control circuit 24 (see FIG. 4), and the position detection Fo / Tr control circuit 24 performs calculation according to the expression (1), and the first detection signal is the outermost layer. One recording layer 4 (see FIG. 2) is set as the reference recording layer, and the optical wedge 42, that is, the second collimator lens 30 is advanced and retracted by the collimator lens actuator 46 so as to have a value set in advance by the equation (2). Then, the focusing position of the recording / reproducing beam is roughly moved in the vicinity of the desired recording layer 4.

(S2 + S3) -S1 (1)
S2-S1 (2)
Here, the detection value from the first light reception detection region 45a is S1, the detection value from the second light reception detection region 45b is S2, and the detection value from the third light reception detection region 45c is S3. When the third detector 45 is shown in FIG. 6, the expression (1) becomes “(S2a + S2b + S3) −S1” and the expression (2) becomes “(S2a + S2b) −S1”.

  Specifically, the position detection Fo / Tr control circuit 24 performs calculation according to the expression (1), and the control circuit 14 controls the drive circuit based on the calculation result to drive the collimator lens actuator 46, and outputs from the third light source 44. The optical wedge 42, that is, the second collimator lens 30 is moved to a position where the spot light 48 of the light beam exists only on the third light receiving detection region 45c (in FIG. 4, it is moved to the second light source 29 side).

  Hereinafter, the state where the spot light 48 of the light beam from the third light source 44 exists only on the third light receiving detection region 45 c is referred to as a return state of the second collimator lens 30.

As shown in FIG. 8, in the return state, the detection value S3 from the third light receiving detection region 45c becomes “S3> P1” with respect to the predetermined value P1, and the position detection signal according to the equation (1) at this time is
(S2 + S3) -S1 = S3> P1
And output from the position detection Fo / Tr control circuit 24 to the control circuit 14.

In FIG. 4, the drive circuit 17 drives the collimator lens actuator 46 under the control of the control circuit 14 to move the second collimator lens 30 away from the second light source 29, and the spot of the light beam from the third light source 44. From the return state where the light 48 exists only on the third light receiving detection region 45c, the spot light 48 of the light beam from the third light source 44 is located on the third light receiving detection region 45c and the second light receiving detection region 45b, and Become. Then, the detection value S2 + S3 from the third light receiving detection region 45c and the second light receiving detection region 45b is “S2 + S3> P1” with respect to the predetermined value P1, and the position detection signal by the equation (1) at this time is
(S2 + S3) -S1 = S2 + S3> P1
And output from the position detection Fo / Tr control circuit 24 to the control circuit 14.

Further, in FIG. 4, the drive circuit 17 drives the collimator lens actuator 46 under the control of the control circuit 14 to move the second collimator lens 30 away from the second light source 29, and the spot of the light beam from the third light source 44. From the state where the light 48 is located on the third light receiving detection region 45c and the second light receiving detection region 45b, the spot light 48 of the light beam from the third light source 44 is located on the first light receiving detection region 45a. . Then, the position detection signal according to the equation (1) is (S2 + S3) -S1 <P1.
When the position detection Fo / Tr control circuit 24 detects that it has become, the position detection Fo / Tr control circuit 24 outputs a focus search ON signal which is a control signal for starting the focus search to the control circuit 14. Upon receiving the focus search ON signal, the control circuit 14 controls the drive circuit 17 to drive the collimator lens actuator 46 and starts a focus search based on the recording / playback focus error signal from the second photodetector 33. . Then, under the control of the control circuit 14, the drive circuit 17 drives the collimator lens actuator 46 to search the first recording layer 4 that is the outermost layer.

  Then, after the elapse of a predetermined time when the search of the recording layer 4 of the first layer is completed, the position detection Fo / Tr control circuit 24 outputs a focus servo ON signal that is a control signal for starting the focus servo to the control circuit 14 together. To do. Then, under the control of the control circuit 14 based on the recording / playback focus error signal from the second photodetector 33, the drive circuit 17 drives the collimator lens actuator 46 to record on the first recording layer 4 which is the outermost layer. Focus the beam for playback.

  The position detection Fo / Tr control circuit 24 calculates a detection signal obtained by photoelectric conversion of the spot light 48 by the third detector 45 at this time from the equation (2), and calculates the value of the first recording layer as the reference recording layer. It is set as a value of the recording layer 4 (hereinafter referred to as a reference value: T1). Then, the control circuit 14 drives the collimator lens actuator 46 so as to obtain a value obtained by subtracting a predetermined value from this reference value, and for example, sets the focus position of the recording / reproducing beam near the recording layer 4 of the second layer. Move roughly.

  That is, since the position of the second collimator lens 30 and the position of the recording layer are correlated, a predetermined value to be subtracted from the reference value is obtained from the correlation, and the collimator lens is set to a value obtained by subtracting the value from the reference value. The actuator 46 is driven to roughly move the focusing position of the recording / reproducing beam near the recording layer 4 (see FIG. 2) of the k-th layer in the servo layer 3 direction.

  Specifically, if the interlayer dimension of adjacent recording layers 4 is ΔZ, the movement of the second collimator lens 30 by the collimator lens actuator 46 when the focusing position of the recording / reproducing beam is roughly moved by one layer of the recording layer 4 is moved. The amount is a value Z shown in the following equation (3).

Z = (fc / fo) 2 × ΔZ (3)
Here, fc is the focal length of the second collimator lens 30, and fo is the focal length of the objective lens 26.

  The rough movement of the focus position of the recording / reproducing beam in the vicinity of the desired recording layer 4 of the k-th layer is obtained by calculating the target value signal Tk by performing the following equation (4) on the reference value: T1, The collimator lens actuator 46 moves the second collimator lens 30 so that the detection signal obtained by photoelectric conversion of the spot light 48 by the third detector 45 matches the target value signal Tk.

Tk = T1- (k-1) * Z (4)
In the present embodiment, since the optical pickup 20 has the moving optical system 20a, for example, in the case of a zone configuration in which the user area in the optical disc 1 is divided into eight in the radial direction, the moving optical system in the radial direction is used. An offset amount is added to the target value detection signal Tk in order to correct a focus shift due to the movement of the second collimator lens 30 at each zone position 20a. When there is no moving optical system 20a, the offset amount is zero.

  The above fc, fo, and offset amount are stored in the ROM 15 of the control circuit 14, and the interlayer dimension ΔZ of the adjacent recording layer 4 is preformatted in the servo layer 3 in advance. ) And (4) are obtained, and control is performed so that the second collimator lens 30 is moved by the collimator lens actuator 46.

  Then, after roughly moving the focus position of the recording / reproducing beam to the vicinity of the desired recording layer 4 of the k-th layer, the control circuit 14 controls the recording / reproducing focus error signal from the second photodetector 33. The drive circuit 17 drives the collimator lens actuator 46 to focus the recording / reproducing beam on the recording layer 4 of the k-th layer.

  The reference recording layer is the first recording layer 4 that is the outermost layer. However, the recording layer 4 is not limited to the first recording layer 4, and the recording layer 4 on the outermost layer side is used as the reference recording layer. The focal position of the recording / reproducing beam may be roughly moved in the vicinity of the recording layer 4 in the k-th layer in the direction.

  The reference recording layer may be the nth recording layer 4 (see FIG. 2), which is the innermost layer. In this case, the focus position of the recording / reproducing beam is roughly moved in the outermost layer direction.

  Here, for example, when data is recorded in the recording layer 4 of the second layer and data is not recorded in the recording layer 4 of the first layer, the servo signal (focus gain / offset) is generated in the servo layer 3. The data is reproduced, and “no recording (unrecorded)” or “recorded” is recognized by the CPU 16 for each layer or zone, and optimum data can be written in the CPU 16 from the combination of the two data, for example. Stored in an EP-ROM (not shown). Further, when information is recorded for each zone in the user area of the recording layer 4 of the next first layer, or for each recording layer 4 thereafter, the EP-ROM is rewritten.

  Specifically, although not shown, the CPU 16 includes time measuring means for measuring an elapsed time from when the spindle motor 18 in the optical recording / reproducing apparatus 11 is rotated to a standby state in the reference layer, Comparing means for comparing the elapsed time measured by the time measuring means with a reference value, and in response to the comparison result of the comparing means, the data (servo signal) reproduced from the servo layer 3 when the elapsed time is within the reference value ) And “no recording (unrecorded)” or “recorded” status information of each recording layer 4, the focus gain and focus offset control can be optimized for each recording layer 4 such as writing to the EP-ROM. Figured.

  If a plurality of recording layers are optimized for each recording layer as in the prior art, the adjustment time becomes longer, resulting in a longer standby time in the reference layer. Information is stored (for each recording layer 4 or for each zone), and when the elapsed time is within the reference value, the data optimized by the servo signal and the state information is written to the EP-ROM in the CPU 16 in order to write the reference layer. The waiting time at can be shortened.

  Next, the operation of the embodiment configured as described above will be described.

  As shown in FIG. 9, in the optical recording / reproducing apparatus 11 of the present embodiment, when the optical disc 1 is inserted into the apparatus in step S1, it is loaded at a predetermined position. When the cartridge detector 13 detects the cartridge 12 in which the optical disk 1 is inserted, the optical pickup 20 is positioned on the innermost circumference of the optical disk 1 in step S2.

  Then, in step S3, the spindle motor 18 is driven to start the rotation of the optical disc 1 so as to rotate to a predetermined specified rotational speed. Subsequently, in step S4, the first light source 19 is turned on in an area other than the innermost user area of the optical disk 1 to irradiate the optical disk 1 with a servo beam. Next, in step S5, based on the servo focus error signal from the first light detector 28, focus search and focus control of the servo beam to the servo layer 3 are started.

  In step S6, the focus servo to the servo layer 3 is completed, and when the focus servo is completed, in step S7, the optical disk 1 waits for a predetermined rotational speed slower than a predetermined specified rotational speed (FIG. 11 ( a)).

  That is, the initial processing of steps S3 to S7 is completed until the rotation of the optical disc 1 reaches a predetermined rotational speed that is slower than a predetermined specified rotational speed.

  Next, in step S8, the third light source 44 is turned on, and the spot light 48 of the light beam from the third light source 44 is photoelectrically converted by the third detector 45 and output to the position detection Fo / Tr control circuit 24. In step S9, the second collimator lens 30 is moved so that the spot light 48 of the light beam from the third light source 44 is in a return state that exists only on the third light receiving detection region 45c. In step S10, the process waits for a return state where the spot light 48 of the light beam from the third light source 44 exists only on the third light receiving detection region 45c.

  Note that the focus search of the servo beam to the servo layer 3 and the start and completion of the focus control in steps S5 and S6 may be simultaneously performed in parallel between steps S8 to S10.

  Next, in step S11, the second light source 29 is turned on in an area other than the innermost user area to irradiate the optical disc 1 with a recording / reproducing beam. At this time, the recording / reproducing beam is in a defocused state with respect to the recording layer 4, and the recording power of the second light source 29 is adjusted based on the temperature information from the temperature sensor 34 in step S12.

  Specifically, the temperature sensor 34 is disposed in the vicinity of the optical disc 1, and the signal detected by the temperature sensor 34 is taken in by the control circuit 14 at regular intervals, and the temperature difference from the temperature at the previous use is detected. To be compared. When the compared temperature difference is equal to or greater than a certain value, the indicated value in the recording power table is rewritten. That is, the recording power table for the inner, middle and outermost tracks in the user area is recorded on the recording means in the control circuit 14, and the recording power table is rewritten by the temperature difference.

  Conventionally, when adjusting the recording power, as shown in FIG. 11 (b), after the rotation of the optical disc 1 reaches the specified rotational speed, the initial processing of the above steps S3 to S7 is performed, and then the step S8 is performed. In the present embodiment, as shown in FIG. 11A, the initial process of steps S3 to S7 is performed at a predetermined speed at which the rotation of the optical disc 1 is slower than a predetermined specified rotational speed. Since the processing is completed before reaching the number, and then the processing of step S8 to step S12 is executed, initial processing such as recording power adjustment can be performed at high speed.

  In step S12, the process waits for the rotation of the optical disc 1 to reach a predetermined specified rotational speed (see FIG. 11A). Next, in step S13, the moving optical system 20a of the optical pickup 20 is moved from the innermost circumference of the optical disc 1 to the control track (Cont. Tr), and the process proceeds to step S14 in FIG.

  The movement from the innermost circumference of the optical disc 1 to the control track (Cont. Tr) is based on the tracking error signal from the first photodetector 28 of the servo layer 3 that is focus-servoed, and the moving optical system of the optical pickup 20 20a is sought in the outermost peripheral direction of the optical disc 1.

  As shown in FIG. 10, in step S14, the spot light 48 of the light beam from the third light source 44 is changed from the return state to the state where the spot light 48 is positioned on the third light receiving detection region 45c and the second light receiving detection region 45b. In step S15, the process waits until the position detection signal according to the expression (1) satisfies “(S2 + S3) −S1 <P1”. When the position detection signal satisfies “(S2 + S3) −S1 <P1”, Based on the recording / playback focus error signal from the second photodetector 33, the focus search and focus control of the recording / playback beam to the recording layer 4 of the first layer are executed, and the recording layer 4 of the first layer is moved to step S17. When the focus servo is completed, the recording layer 4 of the first layer for which the focus servo is completed in step S14 is used as the reference recording layer. And determined, set above formula at that time the value of (2) as a reference value.

  Next, in step S18, the tilt detector 23 in the optical pickup 20 detects the tilt of the optical disc 1, and when there is an abnormality in the tilt of the optical disc 1, predetermined error processing is performed and the cartridge 3 is ejected from the apparatus. .

  Then, in step S19, it is determined whether or not the recording / reproducing beam is moved to the desired recording layer 4. If the recording / reproducing beam is not moved to the desired recording layer 4, the process is terminated, and recording / reproducing is performed on the desired recording layer 4. When the beam is moved, the second collimator lens 30 is moved by the collimator lens moving unit 31 in step S20 by the target value signal Tk based on the above formula (4), and recording is performed on the desired recording layer 4 by the second collimator lens 30. Move the playback beam roughly. Thereafter, focus search and focus control of the recording / reproducing beam to the desired recording layer 4 are executed based on the recording / reproducing focus error signal from the second photodetector 33 in step S21, and the desired recording layer 4 is entered in step S22. When the focus servo is completed, the movement to the desired recording layer 4 is completed in step S23, and the process is terminated.

  As described above, in the present embodiment, the initial process is completed until the rotation of the optical disc 1 reaches the predetermined number of rotations, and then the recording power adjustment process is executed, so that the initial process can be performed at high speed.

  In addition, after setting the reference recording layer, the recording / reproducing beam is roughly moved to the vicinity of the desired recording layer based on the reference recording layer, and then the recording / reproducing beam is focused on the desired recording layer, so that the recording / reproducing beam is A desired recording layer can be accessed quickly and reliably.

Additional Notes: Time measuring means for measuring an elapsed time from the start of rotation of the optical disk by the disk rotating means to a waiting time at the reference layer;
Comparing means for comparing the elapsed time measured by the time measuring means with a predetermined time;
When the comparison means receives a comparison result that the elapsed time is within a predetermined time, the focus gain or the focus offset amount is determined by determining whether the plurality of recording layers or the plurality of recording layers are recorded or not recorded for each zone. The optical recording / reproducing apparatus according to claim 3, further comprising an optimization unit that optimizes the plurality of recording layers or zones of the plurality of recording layers.

1 is a configuration diagram showing a configuration of an optical system of an optical recording / reproducing apparatus according to an embodiment of the present invention. 1 is a configuration diagram showing the configuration of an optical disc that is a three-dimensional optical recording medium used in the optical recording / reproducing apparatus of FIG. Configuration diagram showing configurations of servo layer and recording layer of FIG. The block diagram which shows the structure of the collimator lens moving part of FIG. The block diagram which shows the structure of the 3rd detector of FIG. The block diagram which shows the structure of the 1st modification of the 3rd detector of FIG. The block diagram which shows the structure of the 2nd modification of the 3rd detector of FIG. Explanatory drawing explaining the effect | action of the collimator lens moving part of FIG. First flowchart for explaining the operation of the optical recording / reproducing apparatus of FIG. Second flowchart for explaining the operation of the optical recording / reproducing apparatus of FIG. Explanatory drawing explaining the effect | action of the optical recording / reproducing apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Optical disk 2 ... Board | substrate 3 ... Servo layer 4 ... Recording layer 11 ... Optical recording / reproducing apparatus 12 ... Cartridge 13 ... Cartridge detector 14 ... Control circuit 17 ... Drive circuit 18 ... Spindle motor 19 ... 1st light source 19a ... 1st collimator Lens 20 ... Optical pickup 23 ... Tilt detector 24 ... Position detection Fo / Tr control circuit 25 ... Wavelength dependent mirror 26 ... Objective lens 27 ... Objective lens actuator 28 ... First photodetector 29 ... Second light source 30 ... Second Collimator lens 31 ... Collimator lens moving unit 32, 43 ... Pinhole 33 ... Second photodetector 34 ... Temperature sensor 42 ... Optical wedge 44 ... Third light source 45 ... Third detector 46 ... Collimator lens actuator 47 ... LED light control circuit
Attorney Susumu Ito

Claims (2)

An optical disc having a plurality of recording layers for recording information and a servo layer in which recording conditions of the recording layers are recorded in advance;
A disk rotating means for rotating the optical disk at a predetermined prescribed rotational speed;
A servo focus having an objective lens and a first collimator lens for focusing the servo beam on the servo layer until the rotation speed of the optical disk reaches a predetermined rotation speed slower than the predetermined specified rotation speed. Control means;
A recording / reproducing focus control unit having the objective lens and a second collimator lens for focusing the recording / reproducing beam on the recording layer, which starts an operation following the control operation of the servo focus control unit ; ,
Means for optically detecting the position of the second collimator lens by attaching an optical element to a lens holder of the second collimator lens, and the second collimator lens relative to a predetermined reference value is in the optical axis direction Position detection control means for detecting and controlling the position to move to,
The recording / reproducing focus control for focusing the recording / reproducing beam on a predetermined recording layer as a reference layer when moving the objective lens with respect to each recording layer among the plurality of recording layers Recording / reproducing beam control means for controlling the means , wherein the recording / reproducing beam is predetermined as a reference layer by controlling the movement of the second collimator lens based on the output of the predetermined reference value. After roughly moving to the vicinity of the predetermined recording layer , the focus search and the focus control of the recording / reproducing beam are further performed, and the recording / reproducing beam is applied to the predetermined recording layer as the reference layer. Recording / reproducing beam control means for controlling the recording / reproducing focus control means so as to be focused;
An optical recording / reproducing apparatus comprising:   2. The optical recording / reproducing apparatus according to claim 1, wherein the optically detecting means includes a light emitting element and a light receiving element.

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