JPH0668510A - Integrated optical head and optical disk device - Google Patents

Abstract

PURPOSE:To reduce the number of signal lines from a moving part in an integrated optical head driven with a light source, an objective lens and a detector as an integrated structure. CONSTITUTION:A signal from a photodetector 70 is transmitted by a light emitting element with optical communication. Moreover, a movable part is held by an electrically conductive spring 108, a control signal for a driving section and a signal for driving a light source semiconductor laser 21 are sent in time division and they are demultiplexed by a multiplexer 634 in the movable part in matching with a timing. Furthermore, an information processing circuit 601 is provided in the movable part and the information is processed in the movable part without outputting the signal to an external device. The photodetector 70, an amplifier, a detection circuit, a driving circuit and the information processing circuit 601 are formed on the same board. Thus, by reducing the number of signal wires from the integrated optical head, the fault of driving is eliminated and the servo capability is strengthened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an integrated optical head for optically recording information on a recording medium, optically erasing the information from the recording medium, or reproducing the information recorded on the recording medium. And an optical disk device using this integrated optical head.

[0002]

2. Description of the Related Art Conventionally, an optical head in a read-only type optical disc apparatus such as a compact disc uses a finite magnification objective lens. When the finite-magnification objective lens is moved, the relative position with respect to the light source changes, so that aberration occurs. As a method in which the aberration is not increased by focusing and tracking, for example, as disclosed in JP-A-1-273238, a light source, an objective lens, a detector, etc. are held by a common holding member and moved by a two-dimensional actuator. There is something to do.

[0003]

In an optical head of an optical disk, a beam from an optical beam generating element such as a semiconductor laser is made incident on an objective lens, and a beam on the recording surface of the optical disk is about 1 mm.
The light is condensed to a spot of μm and the amount of reflected light from a bit formed on the optical disc and having a size of about 1 μm, or a change in the polarization direction is detected. The pits are arranged in concentric or spiral tracks in the circumferential direction of the optical disc. Since the optical disk causes surface wobbling and eccentricity as it rotates, it is necessary to make the focused spot of the optical head follow the track of the optical disk. Moving the spot so as to follow the surface wobbling is called the focus, and moving the spot so as to follow the track with respect to the eccentricity is called tracking. This focus
As a tracking method, there is a method of moving the objective lens. The signal indicating the tracking error of the focus and tracking is obtained from the shape or the amount of reflected light from the optical disk, but the beam position on the photodetector changes as the objective lens moves, and An error occurs in the tracking error signal of dust and tracking. As a method that does not deteriorate the error signal even if focus and tracking are performed,
There is a system in which an objective lens, a light source, and a photodetector are integrally moved by an actuator. In this system, a signal line is required between the circuit of the optical disk device in order to send a signal to the light source or output a signal from the detector, so the actuator must move while dragging the signal line. . Therefore, the integrated optical head has a problem that an extra force acts on the actuator, and the focus and tracking are likely to come off.

An object of the present invention is to provide an optical head having a structure in which a light source and a detector are integrated, and moving the actuator as a whole, by diverting the signal line from the optical head and being strong against disturbance. It is to be.

Another object of the present invention is to provide an optical disk device using the above optical head, which is strong against disturbance.

[0006]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides an integrated optical head used in an optical disk device for reproducing at least a movable part that moves relatively to the optical disk device. A driving mechanism for driving the movable portion, and a fixed portion for supporting the movable portion via a supporting member, wherein the movable portion is an optical beam generating element,
An optical system for condensing the light beam from the light beam generating element on the optical disk surface, a photodetector for detecting the light from the optical disk, and an electric signal of the photodetector converted into an optical signal. And a first light generating element for communication,
A first communication photodetector that receives light from the first communication light generation element is included.

Further, the present invention is used in an optical disk device for recording / reproducing, and an integrated optical head for externally receiving a control signal for controlling a light beam and a data signal at the time of recording is provided to the optical disk device. A movable part that moves relatively, a drive mechanism that drives the movable part, and a fixed part that supports the movable part via a support member, and the movable part includes an optical beam generating element, An optical system for condensing the light beam from the light beam generating element on the optical disk surface, a photodetector for detecting the light from the optical disk, a control photodetector, and a control information processing circuit. And the fixed part has a control light generating element, and the control light generating element outputs a control signal for controlling a light beam generated by the light beam generating element. Output as the control photodetector Receives light from the light generating device, said control information processing circuit, the light from the control light detector the light bi - is obtained by the controlling the beam.

According to the present invention, in an integrated optical head used in at least an optical disk device for reproduction, a movable part that moves relatively to the optical disk device, a drive mechanism that drives the movable part, and the movable part. An optical system for converging the optical beam from the optical beam generating element and the optical beam from the optical beam generating element on the optical disk surface. And a photodetector for detecting light from the optical disc, and a control circuit for controlling the drive mechanism in response to a light amount change signal from the optical disc.

Further, according to the present invention, in an integrated optical head used in an optical disc device for recording and reproducing, a movable part that moves relatively to the optical disc device, a drive mechanism that drives the movable part, and the movable part. A movable portion for supporting the optical beam from the optical beam generating element and an optical beam condensing the optical beam from the optical beam generating element on the optical disk surface. A system, a photodetector for detecting light from the optical disc, and a signal switching circuit, wherein the support member is a signal for controlling the drive mechanism and a signal for controlling the optical beam generating element. Are transmitted in a time-division manner, and the signal switching circuit separates and outputs a signal for controlling the drive mechanism and a signal for controlling the optical beam generating element.

Further, according to the present invention, in an optical disk device, an integrated optical head is provided, and the optical beam generating element is
A semiconductor laser, a drive unit having a spindle motor for rotating the optical disc, and a course actuator for moving the integrated optical head in the radial direction of the optical disc, and at least control of the drive unit. And an information processing circuit that performs signal processing.

[0011]

Since the present invention is constructed as described above,
In an integrated optical head used in an optical disc device that reproduces at least, the movable part includes an optical beam generating element,
An optical system for condensing the light beam from the light beam generating element on the optical disk surface, a photodetector for detecting the light from the optical disk, and an electric signal of the photodetector converted into an optical signal. And a light generating element for communication. The drive mechanism drives the movable part. The fixed portion supports the movable portion via a support member. The communication photodetector receives light from the communication light generation element.

In an integrated optical head in which an objective lens, a light source, and a detector are integrally structured, and the whole is driven by a drive section,
The integrated optical head is supplied with the drive current of the semiconductor laser and the drive current of the actuator, and the integrated optical head outputs the signal obtained by the photodetector. Normally, there are three types of output signals from the optical head: an RF signal for reproducing data, a focus error signal for focusing, and a tracking error signal for tracking. Usually, the photodetector is composed of several separate detectors, and produces an RF signal, a focus error signal, and a tracking error signal from the sum or difference signal of the outputs of the respective detectors. The output from the optical head may output the signals of these individual detectors, or may generate and output the RF signal, the focus error signal, and the tracking error signal in the optical head.

In order to output the signal from the photodetector to the outside, the signal from the photodetector is transmitted by transmitting the signal by optical communication between the movable portion and the fixed portion of the integrated optical head. It is possible to reduce the signal line between the movable portion and the fixed portion. As the light emitting element, a solid state light emitting element such as a semiconductor laser (LD) or a light emitting diode (LED) can be used, but the band in which the light intensity of the light emitting element can be modulated must be in the signal band. .

Further, according to the present invention, in the integrated optical head used in the optical disk device for recording / reproducing, the movable part is
An optical beam generating element, an optical system for condensing the optical beam from the optical beam generating element on the optical disk surface, a photodetector for detecting the light from the optical disk, and a control optical detection. And a control information processing circuit. The drive mechanism drives the movable part. The fixed portion supports the movable portion via a support member. The control light generating element outputs a control signal for controlling the light beam generating element as an optical signal, the control photodetector receives light from the control light generating element, The control information processing circuit controls the light beam generating element by the light from the control photodetector.

In the optical head for recording, it is necessary to change the current flowing through the optical beam generating element to change the optical output. The optical beam generating element is driven by transmitting a signal for controlling the light intensity of the optical beam generating element for reproducing and recording information on the optical disk to the movable section as an optical signal from the fixed section. No need for signal lines for
At this time, a drive circuit for driving the optical beam generating element in the movable portion of the optical head, an information processing circuit for controlling the drive circuit, and a circuit for keeping the optical output of the optical beam generating element constant. It is desirable to have As a signal for controlling the light intensity of the optical head, the setting of the optical output for reproduction, recording and erasing and the modulation signal of the recording data are transmitted. The output of the optical head can be changed by making it proportional to the control light intensity. Further, when transmitting the control signal as a digital signal, the information processing circuit uses an output power setting signal and a data signal.
It controls the optical output of the optical head. To control the output power, a modulation pattern not used in the data modulation is used. The integrated optical head may have a photodetector for detecting the optical output of the optical beam generating element and an auto power control (APC) circuit for keeping the optical output of the optical beam generating element at a predetermined value. desirable.

The photodetector, the information processing circuit, and the circuits such as the preamplifier can be formed on the same silicon substrate. By using such an optoelectronic integrated circuit (OEIC), the size and weight of the integrated optical head can be reduced.

Further, according to the present invention, in an integrated optical head used in an optical disk device for reproducing at least, the movable part is an optical beam generating element and an optical beam from the optical beam generating element. An optical system for condensing light on the surface and a photodetector for detecting light from the optical disk are mounted. The drive mechanism drives the movable part. The fixed portion supports the movable portion via a support member. The control circuit controls the drive mechanism according to a signal indicating a change in the amount of light from the optical disc.

The signal indicating the error of the position of the drive mechanism with respect to the target point is obtained from the signal of the detector of the integrated optical head,
Since the integrated optical head also has a mechanism for driving the optical head such as a coil, a signal for controlling the drive mechanism is created in the integrated optical head, and the signal is sent to the drive mechanism so that the control signal is sent from the detector of the optical head. It is not necessary to output a signal for manufacturing.

Further, according to the present invention, in the integrated optical head used in the optical disk device for recording / reproducing, the movable part is
An optical beam generating element, an optical system for focusing the optical beam from the optical beam generating element on the optical disk surface, a photodetector for detecting light from the optical disk, and a signal switching circuit. Equipped with. The drive mechanism drives the movable part. The fixed portion supports the movable portion via a support member. The support member transmits a signal for controlling the drive mechanism and a signal for controlling the optical beam generating element in a time division manner, and the signal switching circuit includes a signal for controlling the drive mechanism and the optical beam. -Separate and output the signal that controls the memory generating element.

The movable part of the optical head is driven by having a focus and a tracking coil in the movable part, a permanent magnet and a yoke in the fixed part, and supplying a control current to the coil. The movable part has a support member, for example, a structure in which four metal springs are used to hang it down. In this structure, a control current is supplied to the focus coil and the tracking coil through the metal spring.

In the present invention, the signal for controlling the optical beam generating element is transmitted by time-divisionally transmitting the signal for controlling the driving mechanism and the signal for controlling the optical beam generating element through the electrically conductive spring. No signal line is required.

A sample servo (SS) is used as a servo system of an optical disk used in an optical head that transmits signals in a time division manner.
Method is preferable. In the SS system, the servo area and the data area are separated on the optical disk, and the focus servo and the tracking servo are performed only in the servo area.
Therefore, when the beam is in the servo area, the servo signal is transmitted through the spring, and when it is in the data area, the data modulation signal is transmitted and recorded. Servo area and data
A signal that changes the optical output is transmitted at the boundary of the optical region.

The optical head is equipped with a switching circuit such as a multiplexer for switching between the servo signal and the data signal. Further, it is desirable to have an information processing circuit, a central information processing circuit, etc. in order to control the change in the output of the light beam generating element.

The remaining two springs are used as power supply lines for information processing circuits, photodetectors and the like.

Further, according to the present invention, by using the above-mentioned integrated optical head in the optical disc device, it is possible to manufacture an optical disc device in which the focus and the tracking are hard to come off even when disturbance acts.

[0026]

EXAMPLES Examples of the present invention will be described below.

1 and 2 show an optical head 1 according to the present invention.
An example is shown.

FIG. 1 is a sectional view of the optical head of this embodiment. FIG. 2 shows a perspective view of the optical head of this embodiment. The integrated optical head includes a bobbin 101 and a focus coil 102.
, Tracking coil 103, magnet 104, and yaw
105, leaf spring 106 (support member), and power supply line 1
07 and an integrated optical head module 210 (semiconductor laser
The chip 21, light quantity monitor sensor 22, finite magnification objective lens 50, PBS 30, λ / 4 plate 31, total reflection mirror 32, photodetector 70, RF signal LD 25
0 (first communication light generating element and tracking signal first driving light generating element), and focus signal LD
252 (first drive light generating element for focus signal)
), An RF signal PD 251 (first optical communication photodetector and tracking signal first drive photodetector), and a focus signal PD 253 (focus signal first). Driving light detector 1) and a light output control LD
256 (light generating element for control) and PD25 for light output control
7 (control photodetector) and a fixed part 1000 (having an optical head chassis 15). Bobbin 101, focus coil 102, and tracking coil 103
And the integrated optical head module 210 form a movable part. The focus coil 102, the tracking coil 103, the magnet 104, and the yoke 105 constitute a drive mechanism.

FIG. 1 is a sectional view of the optical head of this embodiment. A linearly polarized beam from a semiconductor laser chip 21 which is an optical beam generating element for recording / reproducing an optical disc is reflected by a polarizing beam splitter (PBS) 30,
It is circularly polarized by the λ / 4 plate 31, and is condensed on the recording surface of the optical disc 300 by the objective lens 50. The reflected light from the optical disc becomes a linearly polarized light which is rotated by 90 ° from the incident light on the λ / 4 plate 31, passes through the PBS 30, and is reflected by the total reflection mirror 32.
It is detected by the photodetector 70. The signal detected by the photodetector 70 is processed by the OEIC chip 200 including a preamplifier. The objective lens has an effective diameter of 2 mm, an optical disk side numerical aperture of 0.55, a light source side numerical aperture of 0.15, and a working distance of 0.7 m.
m and the substrate thickness is 0.6 mm.

An optical output control LD 256 for transmitting a signal for controlling the optical output of the semiconductor laser 21 and a modulation signal for recording to the integrated module is provided in the fixed portion of the optical head. The optical signal from the optical output control LD 256 is received by the optical output control PD 257 provided in the optical head movable part,
Controlling a drive circuit provided on the EIC chip 200,
The semiconductor laser chip 21 was driven by the current from the drive circuit. The optical output of the semiconductor laser chip 21 is OEIC.
The light amount monitor 22 formed on the chip 200 detects.

Semiconductor laser chip 21, PBS 30, λ
The / 4 plate 31, the total reflection mirror 32, the objective lens 50, the photodetector 70, and the OEIC chip 210 are integrated into an integral type module 210 and attached to the bobbin 101. In order to prevent the semiconductor laser chip 21 and the photodetector 70 from being deteriorated due to oxidation or the like, the integrated module 210 has a hermetically sealed structure, and nitrogen gas is sealed therein.

The control signal for performing the focus and tracking is formed from the signal detected by the photodetector of the reflected light from the optical disk. The optical head needs to generate a reproduction signal (RF signal) of the optical disk, a focus error signal indicating an error from the target position in the focus direction, and a tracking error signal indicating a position error in the tracking direction. In this embodiment, these signals are formed in the optical head, emitted as a light intensity modulation signal by a light generating element provided in the optical head, and detected by a photodetector provided in the optical head chassis. The optical head of this embodiment records / reproduces data on / from an optical disk of a sample servo (SS) system as a tracking servo system. In the SS method, two pre-pits off-track to the left and right with respect to the track center are formed on the optical disc, and a tracking error signal is formed from the difference between the reproduction signal amplitudes of these two pre-pits. Therefore, in the SS method, the optical head may reproduce the RF signal and the focus error signal. Therefore, in this embodiment, a semiconductor laser (LD) for RF signal transmission is provided in the movable portion of the optical head.
And a light emitting diode (LE for transmitting a focus error signal)
Two light emitting elements of D) are provided, and two photodetectors (PD) for receiving respective optical signals are provided in the optical head chassis. In FIG. 1, the RF signal LD 250 and the RF signal PD
251 is shown.

FIG. 2 shows a perspective view of the optical head of this embodiment. Attach the integrated module 210 to the bobbin 101. The laser light is emitted from the objective lens 50. Bobbin 1
01 is suspended at the center by four leaf springs 106, one of which is fixed to the fixing portion. Bobbin 101 is
It has a scrap coil 102 and a tracking coil 103,
By passing a current through these coils, the optical head shield
It is movable by the electromagnetic force between the magnet 104 and the yoke 105 fixed to the coil and the coil. Leaf spring 106
Is made by etching phosphor bronze. Two of the leaf springs 106 are used for the focus coil 102.
Then, the remaining two coils pass a current through the tracking coil 103. The bobbin 101 moves in the vertical direction by this electromagnetic force to perform tracking by rotating the focus around the center of the bobbin 101. A wire 107 for supplying power to the OEIC chip is connected to the center of the bobbin 101.
Since the center of the bobbin 101 is the center of rotation, the power supply line 10
From 7, resistance of tracking motion does not work.

In the reproduction-only optical head, the PBS 3 is used.
Half-Miller may be used instead of 0, and a λ / 4 plate need not be used. Further, the LD 256 for controlling the optical output and the PD 257 for controlling the optical output are not required, and the semiconductor laser chip 2
1 may output a constant output.

FIG. 3 shows the structure of the detection system. As the detector, a four-division sensor 71 was used. The astigmatism method was used as the focus error detection method. In FIG. 1, the reflected light from the optical disc 300 is transmitted through a parallel flat plate that is inclined when reflected by the total reflection mirror 32, so that astigmatism occurs.
When the spot of the objective lens just focuses on the recording surface, if the detector is placed at the midpoint between the two focal lines of the reflected light having astigmatism, the beam on the detector will be as shown in FIG. 3 (b). The shape of the mu will be circular. When there is no recording surface at the focal position of the spot, the beam becomes a vertically long or horizontally long ellipse due to the distance of the optical disk. Therefore, it is possible to add a signal from a diagonal sensor of the four-division sensor and obtain a focus error signal from the difference signal between the signals. The RF signal can be obtained from the sum signal of the four sensors. In the present embodiment, the focus error signal is RF by the focus LED.
The signal is converted into an optical signal by the LD for RF signal. As these light emitting elements, solid-state light emitting elements that can be modulated in the frequency band of each signal are desirable. Each optical signal is converted into an electric signal by the focus PD and the RF signal PD provided in the optical head chassis.

FIG. 4 shows a block diagram of the circuit of this embodiment. A signal from the sensor 70 is converted into a current / voltage by a preamplifier 616, and a focus error signal detection circuit 620 for producing a focus error signal and an RF signal detection circuit 622 for producing an RF signal are passed. R for each signal
A drive circuit 630 for driving the LD 250 for the F signal and a fo
The LD 250 for RF signal and the LED 25 for focus signal are driven by the drive circuit 631 which drives the LED 252 for dust signal.
It is modulated and output as a 2 optical signal. The sensor 70, the preamplifier 616, the focus error signal detection circuit 620, the RF signal detection circuit 622, the RF signal LD drive circuit 630, and the focus signal LED drive circuit 631 are formed on the same silicon substrate to form an OEIC chip. It is set to 200. Further, the OEIC chip 200, the RF signal LD 250, and the focus signal LED 252 are integrated into a module 210.
Attach to. The optical signal of the LD 250 for RF signal and the optical signal of the LED 252 for focus signal are provided to the optical head chassis, respectively, the PD for RF signal 251 and the PD for focus signal PD.
253 converts into an electric signal. P for focus signal
The signal received at D253 is input to the focus servo circuit 612 to generate a current for driving the focus coil 102. In addition, the signal received by the RF signal PD 251
It is input to the R servo circuit 613 and the demodulation circuit 651. TR
The servo circuit generates a current for driving the tracking coil 103. The demodulation circuit 651 obtains a reproduction signal of the optical disc.

Next, the light output control of the semiconductor laser chip 21 will be described. A signal for controlling the output of the semiconductor laser chip 21 and a modulation signal for recording are created by the modulation circuit 650, output as an optical signal by the LD 256 for optical output control, and the PD 2 for optical output control provided on the bobbin of the optical head.
Receive at 57. The information processing circuit 601 reproduces, records,
The control signal of the optical output for erasing and the modulation signal for recording are separated, and the LD drive circuit 615 is controlled. LD drive circuit 61
5, the semiconductor laser chip 21 is driven. The light output of the semiconductor laser chip 21 is detected by the light amount monitor sensor 22, and feedback is performed by the APC circuit 617 so as to obtain a predetermined output.

5 and 6 show another embodiment of the present invention.
In this embodiment, a continuous servo (CS) system is used as the tracking servo system. FIG. 5 shows the structure of the integrated optical head. A linearly polarized beam from the semiconductor laser 21 is reflected by a polarizing beam splitter (PBS) 30, circularly polarized by a λ / 4 plate 31, and condensed on a recording surface of an optical disk 30 by an objective lens 50. . The reflected light from the optical disk becomes linearly polarized light which is rotated by 90 ° from the incident light at the λ / 4 plate 31, passes through the PBS 30, and is reflected at the total reflection film 32.
It enters the micro prism 33. Micro prism 3
3 has a half mirror, which is divided into two optical paths and is incident on a three-division sensor 71 and a three-division sensor 72. The signal detected by the photodetector is the OE including the preamplifier.
It is processed by the IC chip.

FIG. 6 shows the detection system. In this embodiment, the front-back differential method is used as the focus error detection method, and the push-pull method is used as the tracking error detection method. Figure 5
The beam entering the two detectors by the micro prism 33 of
The optical path length of the mu is different. At the just focus position, a three-division sensor 71 on the disc side and a three-division sensor 72 in the opposite direction to the disc side with respect to the focal point of the reflected light are placed, and the beam on the two sensors at the time of the just focus. Keep the sizes almost the same. When the distance from the just focus is changed, the beam sizes on the two sensors change.

The focus error signal is the sum signal of the central sensor of the three-divided sensor 71 and the two sensors outside the three-divided sensor 72, the central sensor of the three-divided sensor 72 and the two sensors outside the three-divided sensor 71. Of the sum signal of and the difference signal.

The tracking error signal is a three-division sensor 7
It is obtained from the difference signal of the sum signal of the center sensor of 1 and the center sensor of the three-division sensor 72, and the sum signal of the two sensors outside the three-division sensor 71 and the two sensors outside the three-division sensor 72.

In order to output the RF signal, the focus error signal, and the tracking error signal, R is applied to the movable part of the optical head.
LD 250 for F signal, LED 25 for focus error signal
2. A tracking error signal LED 254 is provided to convert each signal into an optical signal and output it. Optical head chassis, RF signal PD 251, focus signal PD
A tracking signal PD 255 is provided to receive the optical signal.

Another embodiment will be described with reference to FIG. Figure 7
FIG. 3 is a block diagram of a circuit of this embodiment. The sensor 70 receives the reflected light from the optical disk, converts it into an electric signal, and inputs it into the preamplifier 616. The signal from the preamplifier 616 is
It is input to the focus error detection circuit 620, the tracking error detection circuit 621, and the RF signal detection circuit. A signal from the focus error detection circuit 620 enters a focus servo circuit 612 (a control circuit for controlling the driving mechanism) and generates a current for driving the focus coil 102. A signal from the tracking error detection circuit 621 enters a tracking servo circuit 613 (a control circuit for controlling the drive mechanism) and generates a current for driving the tracking coil 103. The signal from the RF signal detection circuit 622 is converted into an optical signal by the RF signal LD 250 driven by the RF signal LD drive circuit 630, and detected by the RF signal PD provided in the optical head chassis. This detection signal is passed through the demodulation circuit 651 to obtain a reproduction signal. Sensor 70, preamplifier 616, focus error signal detection circuit 620, tracking error signal detection circuit 621, R
F signal detection circuit 622, focus servo circuit 612,
The tracking servo circuit 613, the RF signal LD drive circuit 630, and the focus signal LED drive circuit 631 are formed on the same silicon substrate to form the OEIC chip 200. Furthermore, OEIC chip 200 and LD for RF signal
250 and semiconductor laser chip 21 for optical disk recording / reproduction
To the integrated module 210.

In this embodiment, the bobbin is hooked by four springs made of phosphor bronze. Two of these springs are used for signal transmission and the other two are used for power supply. The modulated current from the modulation circuit 650 is driven through the two LD drive current springs 108 to drive the optical disk recording / reproducing LD 21. The remaining two are springs 1 for feeding the integrated module
Used for 09.

FIG. 8 shows a sectional view of the optical head of this embodiment. The beam of linearly polarized light from the semiconductor laser chip 21 is reflected by the total reflection mirror 40, further reflected by the polarization beam splitter (PBS) 30, and circularly polarized by the λ / 4 plate 31, and the objective lens 50. Then, the light is focused on the recording surface of the optical disc 30. The reflected light from the optical disk becomes linearly polarized light that is rotated by 90 ° from the incident light at the λ / 4 plate 31, passes through the PBS 30, is reflected by the total reflection mirror 32, is reflected by the total reflection mirror 34, and is detected by the photodetector 70. Detected in. The signal detected by the photodetector 70 is an OEI including the photodetector 70 and a preamplifier.
It is processed by the C chip 200.

Semiconductor laser chip 21, PBS 30, λ
/ 4 plate 31, total reflection mirror 32, objective lens 50, total reflection mirror 34, and OEIC chip 200 including the photodetector 70 as an integral type integrated module 210, and bobbin 101
Attach to. Semiconductor laser chip 21 and photodetector 7
Integrated module to prevent deterioration due to oxidation
The valve 210 has a sealed structure and is filled with nitrogen gas.

FIG. 9 shows a perspective view of the optical head of this embodiment. The bobbin 101 performs a vertical movement and a rotational movement by an electromagnetic force of the magnet 104 and the yoke 105 by passing a current through the focus coil 102 and the tracking coil 103, and performs focus and tracking.
The bobbin is a leaf spring 106 made of phosphor bronze fixed to the supporting portion.
Have been caught in. Two of these springs are used for the LD drive signal leaf spring 108, and the remaining two are used for the power feed leaf spring 109. The semiconductor laser chip 21 has a heat sink 23.
The heat sink 23 is exposed to the upper surface of the integrated module 210 for heat dissipation.

Another embodiment will be described with reference to FIG. FIG. 10 is a block diagram of the circuit of this embodiment. Sensor 7
0, preamplifier 616, focus error signal detection circuit 6
20, RF signal detection circuit 622, LD 25 for RF signal
0, focus signal LED 252, RF signal LD drive circuit 630, focus signal LED drive circuit 631
Function is the same as in the embodiment of FIG. 4 and is designated by the same number. Next, the transmission of the LD drive control signal, the focus servo signal, and the tracking servo signal will be described.
In this embodiment, the SS method is adopted as the servo method. S
In the S system, the servo area and the data area are separated on the optical disk, and the focus servo and the tracking servo are performed only in the servo area. In this embodiment, two of the four springs are used for power supply, and two of them are used as signal lines for time-sequentially transmitting an LD drive signal, a focus servo signal, and a tracking servo signal for recording / reproducing an optical disk. Used as. The signals from the modulation circuit 650, the focus servo circuit 612, and the tracking servo circuit 613 are converted into time series signals by the multiplexer 633 (switching circuit). This signal is passed through the signal transmission spring 108 to the OEIC.
Send to module 200. A multiplexer 634 on the OEIC module 200 separates an LD modulation signal, a focus servo signal, and a tracking servo signal in accordance with the timing of each signal. The LD modulation signal is input to the central information processing circuit 601, and the LD driving circuit 61
The output of 5 is controlled. The LD drive circuit 615 outputs a modulation current corresponding to the optical output of reproduction, recording, and erasing according to the LD control signal separated from the multiplexer 634,
The semiconductor laser chip 21 is driven. The output power of the semiconductor laser chip 21 is detected by the light amount monitor sensor 22 provided in the OEIC module 200, and the LD drive circuit 615 is controlled by the auto power control (APC) circuit 617 so as to keep the light output constant. Control. The focus servo signal is sent to the focus coil 102 and the tracking servo signal is sent to the tracking coil 103 to control the two-dimensional actuator.

FIG. 11 shows the timing of the signals sent in time series. FIG. 11A shows the arrangement of pre-pits on the sample servo optical disk and the reproduction signal thereof. FIG. 11 (a)
As described above, in the SS system, the servo area and the data area are separated. The focus error signal and the tracking error signal are created from the reproduced signals of the mirror surface and the pre-pit of this servo area, and each servo is performed only in the servo area. Therefore, a signal is transmitted to the multiplexer in the following procedure. At the time of recording, when the servo area is entered, a signal for making the output of the semiconductor laser the reproducing light power is sent. This reproduction light power is maintained in the servo area. next,
The focus is obtained from the focus error signal obtained from the reproduction of the mirror section.
Send a cascade signal. Next, the tracking servo signal obtained by reproducing the wobble pit is sent. Finally,
Sends a data signal for data recording. Since it is not necessary to modulate the power of the LD during reproduction, the power of the LD is set to the reproduction light power in advance and only the focus servo signal and the tracking servo signal are sent. The separation multiplexer on the side of the optical head separates these signals at their respective timings and outputs them to their respective elements.

The power supply to the integrated optical head is not limited to the electric conduction line as in the present embodiment, but electromagnetic energy such as light is emitted from the outside to be converted into an electric signal inside the integrated optical head. good.

In the present invention, in an integrated optical head used in an optical disk device for recording / reproducing, an optical beam generator and an optical beam from the optical beam generator are provided.
A movable part on which an optical system that collects light from the optical disc and a photodetector for detecting light from the optical disc are mounted,
A second communication light that has a drive mechanism that drives the movable portion and a fixed portion that supports the movable portion via a support member, and the fixed portion converts a recorded electrical signal into an optical signal. The movable portion may include a generating element, and the movable portion may include a second communication photodetector that receives light from the second communication light generating element.

In an integrated optical head used in at least an optical disk device for reproduction, an optical beam generating element and an optical system for converging the optical beam from the optical beam generating element on the optical disk surface. A movable part on which a photodetector for detecting light from the optical disc is mounted, a drive mechanism for driving the movable part, and a fixed part for supporting the movable part via a support member, The support member may transmit an electric signal from the photodetector.

Further, in an integrated optical head used in an optical disk device for recording and reproducing, an optical beam generating element and an optical system for converging the optical beam from the optical beam generating element on the optical disk surface. A movable part on which a photodetector for detecting light from the optical disc is mounted, a drive mechanism for driving the movable part, and a fixed part for supporting the movable part via a support member, The support member may carry recorded electrical signals.

Examples of the optical disk medium used in the present invention are shown below.

FIG. 12 shows an embodiment showing the structure of an optical disk medium having a diameter of 64 mm. The optical disc 300 has a protective case.
The laser beam is built into the case 340, and the laser beam is a protective case 340.
An optical path is opened by sliding a slidable protective cover 330 attached to the light source, and irradiation is performed through an opening 335. A magnetic chuck for joining to the motor is attached to the optical disc 300. For the optical disk substrate, glass having a thickness of 0.6 mm, polycarbonate, and PMMA were used. By setting the diameter of the disk substrate to 64 mm, the amount of surface wobbling was reduced to about 1/2 even at the same surface wobbling angle as in the conventional disk having a diameter of 130 mm, and the case thickness was set to 3.5 mm.

An InSbTe-based phase change recording medium was used as the optical disc medium, and the recording film 400 was formed on the substrate 301. The recording was made by forming an amorphous in the crystalline phase and detecting the difference in reflectance. Overwriting was performed on this recording medium using the optical head of the present invention. In addition, as the recording medium, a phase change type rewritable type medium such as GeSbTe type or GeTe type, or a write-once type medium capable of writing once can be used. Furthermore, TbFeCo system, GdFeC
Recording / reproduction can be performed using the optical head of the present invention by adjusting the polarization of the optical disk of a magneto-optical disk using a magneto-optical recording material such as o-system and changing the detection optical system. it can. Further, it can be used for a reproduction-only optical disc.

As the format of the optical disk 300, a sample servo format of 4-15 modulation is used.
The number of sectors per track was 16, the data area was in the range of 32 mm to 64 mm in diameter, and the storage capacity was 80 MB on one side. This optical recording medium has a rotation speed of 3600 rp.
In m, the effective data transfer rate after error correction was 3.9 Mb / s. Besides this, a continuous servo format of 2-7 modulation or the like can be used as the format.

The case is not limited to a structure in which a beam is incident through the opening, but a beam is passed through the transparent case.
A system of injecting light may be used. When the beam is incident through the case, it is necessary to match the thickness of the substrate with the thickness of the case so as to obtain a predetermined thickness. The thickness of the substrate is preferably thin in order to make the case thin.
mm to 0.1 mm is desirable.

Next, an embodiment of the optical disk device of the present invention will be described.

13 and 14 show an embodiment showing the structure of the optical disk device. Information is recorded / reproduced on / from the optical disc 300 by the spindle motor 900.
00 is rotated and a laser beam is emitted from the optical head 10. The optical head 10 is a course actuator 700.
Mounted on the optical disc 300 and is movable in parallel with the optical disc 300. These are built in the optical disc device chassis 800. In this embodiment, a motor having a diameter of 8 mm is used as the course actuator 700, and power is transmitted by a worm gear. The thickness of the optical head 10 was 5 mm, the weight was 5 g, and the average access time was about 40 ms. Spindle mode
As the motor 900, a semicircular motor having a small diameter on the optical head side is used so that the optical head can accelerate to the inner circumference of the optical disk. The thickness of the optical disk device excluding the circuit board 670 is 10 mm, and the thickness of the optical disk device when the circuit board 670 is added is 15 mm, and it can be mounted on a laptop type or notebook type personal computer or a workstation.

FIG. 15 is a system configuration showing up to the data processing unit of the optical disk device. In the figure, the medium and drive unit are composed of an optical disk 300, an optical head 10, a spindle motor 900, and a course actuator 700. The drive microcomputer 600 controls the drive unit and performs signal processing. The drive microcomputer 600 includes a spindle servo 611 and a focus servo 61 as a mechanical system.
2. The tracking servo 613 and the course actuator servo 614 are controlled. The drive microcomputer 600 also controls the modulation signal 660 of the optical head.
Further, the detection signal 662 from the optical head is processed. The control microcomputer 605 sends an operation command to the drive microcomputer 600, receives a reproduction signal from the optical disk, and performs error correction. Furthermore, the control microcomputer 605
Also controls the interface when connecting to another system. The spindle motor servo 61
Reference numeral 1 controls the rotation speed of the spindle motor 900, and CAV (Constant Angular Velocity) is used for this rotation speed control.
There are control, CLV (Constant Linear Velocity) control, MCLV (Modulated Constant Linear Velocity) control and the like, which can be appropriately selected according to the system.

The optical head of the present invention can be miniaturized.
Therefore, the optical disc device using this optical head is also small,
It is lightweight and thin and easy to handle.
Therefore, it can be used for stationary and laptop personal computers, workstations, word processors, fax machines, copy machines, television game machines, telephones, electronic still cameras, video cameras, and mobile phones. It is suitable for a system used as a common memory medium for a music player, an electronic system notebook, a calculator, a measuring instrument, a visual presentation device and the like. Each device can be shared as a memory medium by using a compatible optical disk device.

[0063]

According to the present invention, a light source and a detector are integrally structured, and in an integrated optical head for moving an actuator as a whole, a signal line emitted from the optical head is reduced to provide an optical head that is strong against disturbance. it can.

Further, it is possible to provide an optical disc device using the above optical head, which is strong against disturbance.

[Brief description of drawings]

FIG. 1 is a sectional view of an integrated optical head according to the present invention.

FIG. 2 is a perspective view of an integrated optical head according to the present invention.

FIG. 3 is a configuration diagram of a detection system of the integrated optical head according to the present invention.

FIG. 4 is a circuit block diagram of an integrated optical head according to the present invention.

FIG. 5 is a cross-sectional view of a CS type integrated optical head.

6 is a configuration diagram of a detection system of the integrated optical head of FIG.

FIG. 7 is a circuit block diagram of an optical head having a servo circuit.

8 is a sectional view of the optical head of the embodiment of FIG.

9 is a perspective view of the optical head of the embodiment of FIG.

FIG. 10 is a circuit block diagram of an optical head that transmits signals in a time division manner.

FIG. 11 is a timing diagram of time division transmission.

FIG. 12 is an external view of an optical disk device according to the present invention.

FIG. 13 is a sectional view of an optical disc device according to the present invention.

FIG. 14 is a front view of an optical disk device according to the present invention.

FIG. 15 is a circuit block diagram of an optical disk device according to the present invention.

[Explanation of symbols]

10 ... Optical head, 15 ... Optical head chassis, 20 ... Semiconductor laser, 21 ... Semiconductor laser chip, 22 ... Light quantity monitor sensor, 23 ... Heat sink, 30 ... PBS, 31 ...
λ / 4 plate, 32 ... Total reflection mirror, 33 ... Micro prism, 34 ... Total reflection mirror, 50 ... Finite magnification objective lens, 7
0 ... Photodetector, 71 ... 3-division sensor, 71 ... 3-division sensor, 100 ... Two-dimensional actuator, 101 ... Bobbin,
102 ... Focus coil, 103 ... Tracking coil, 104 ... Magnet, 105 ... Yoke, 106 ... Leaf spring,
107 ... power supply line, 108 ... LD drive signal leaf spring, 1
09 ... Power supply leaf spring, 200 ... OEIC chip, 210
... Integrated optical head module 220 ... Integrated optical head,
250 ... LD for RF signal, 251 ... PD for RF signal, 2
52 ... Focus signal LD, 253 ... Focus signal PD, 254 ... Tracking signal LD, 255 ... Tracking signal PD, 256 ... Optical output control LD, 2
57 ... PD for optical output control, 300 ... Optical disc, 301
… Optical disc substrate, 320… Magnet chuck, 33
0 ... Protective cover, 335 ... Opening part, 340 ... Protective case
400, recording film, 600, drive microcomputer, 60
1 ... Information processing circuit, 605 ... Control microcomputer, 6
11 ... Spindle servo, 612 ... Focus servo,
613 ... Tracking servo, 614 ... Course actuator servo, 615 ... Laser driver, 616 ... Preamplifier, 617 ... APC circuit, 620 ... Focus error signal detection circuit, 621 ... Tracking error signal Detection circuit,
622 ... RF signal detection circuit, 630 ... LD drive circuit, 6
31 ... LED drive circuit, 633 ... Combining multiplexer, 634 ... Separation multiplexer, 650 ... Modulation circuit, 651 ... Demodulation circuit, 670 ... Circuit board, 700 ... Course actuator, 800 ... Optical disk device chassis
Si, 900 ... Spindle motor.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tetsuya Fushimi 4026 Kuji Town, Hitachi City, Ibaraki Prefecture Hitate Manufacturing Co., Ltd.Inside Hitachi Research Laboratory (72) Inventor Saburo Yasukawa 4026 Kuji Town, Hitachi City Hitachi, Ltd. Hitachi Research Laboratory (72) Inventor Nobuyoshi Tsuboi 4026, Kuji-machi, Hitachi City, Ibaraki Prefecture Hitachi Research Laboratory, Hitachi, Ltd.

Claims (14)

[Claims] 1. An integrated optical head used in at least an optical disk device for reproduction, comprising: a movable part that moves relative to the optical disk device; a drive mechanism that drives the movable part; and the movable part. A movable portion that supports the light beam from the light beam generating element; and an optical system that focuses the light beam from the light beam generating element on the optical disk surface. A photodetector for detecting light from the optical disc,
A first communication light generating element for converting an electric signal of the photodetector into an optical signal, and the fixing section receives the light from the first communication light generating element for the first communication. An integrated optical head having an optical detector for use. 2. An integrated optical head used in at least an optical disk device for reproduction, comprising: a movable part that moves relative to the optical disk device; a drive mechanism that drives the movable part; and the movable part. A movable portion that supports the light beam from the light beam generating element; and an optical system that focuses the light beam from the light beam generating element on the optical disk surface. A photodetector for detecting light from the optical disc,
An error detection circuit that generates a signal for controlling the drive unit from a signal of a light amount change from the optical disc, and a first drive light generation element that converts an electric signal of the error detection circuit into an optical signal The fixing unit has a first drive photodetector that receives light from the first drive light generation element, and outputs a signal output from the first drive photodetector to the outside. The integrated optical head, which receives a command signal for controlling the drive unit from the outside and outputs the command signal to the drive unit. 3. An integrated optical head used in at least an optical disk device for reproduction, comprising: a movable part that moves relative to the optical disk device; a drive mechanism that drives the movable part; and the movable part. A movable portion that supports the light beam from the light beam generating element; and an optical system that focuses the light beam from the light beam generating element on the optical disk surface. A photodetector for detecting light from the optical disc,
An error detection circuit that generates a signal for controlling the drive unit from the signal of the light amount change from the optical disc, and outputs an electric signal of the error detection circuit to the outside through the fixing unit, and the fixing unit, A second signal receiving an instruction signal for controlling the drive unit from the outside and converting the instruction signal into an optical signal
And a second drive photodetector that receives light from the second drive light generation device, the second drive photodetector being provided in the movable portion. 4. Used in an optical disk device for recording and reproducing,
An integrated optical head for externally receiving a control signal and a data signal for controlling a light beam at the time of recording, comprising a movable part that moves relative to an optical disk device, and a drive mechanism that drives the movable part. And a fixed portion that supports the movable portion via a support member, the movable portion including an optical beam generating element and an optical beam from the optical beam generating element on an optical disk surface. An optical system for condensing, a photodetector for detecting light from the optical disc,
A control photodetector and a control information processing circuit are provided, the fixed part has a control light generation element, and the control light generation element is generated by the light beam generation element. A control signal for controlling a light beam is output as an optical signal, the control photodetector receives light from the control light generation element, the control information processing circuit, the control light detection. An integrated optical head, characterized in that the optical beam is controlled by light from a container. 5. An integrated optical head used in an optical disk device for recording and reproducing, comprising: a movable part that moves relative to the optical disk device; a drive mechanism that drives the movable part; and the movable part. A fixed part supported via a support member, the fixed part has a second communication light generating element for converting an electric signal to be recorded into an optical signal, and the movable part is an optical beam. A beam generating element, an optical system for converging the optical beam from the optical beam generating element on the optical disk surface, and a photodetector for detecting the light from the optical disk,
An integrated optical head, comprising: a second communication photodetector that receives light from the second communication light generation element. 6. An integrated optical head used in at least an optical disk device for reproduction, comprising: a movable part that moves relative to the optical disk device; a drive mechanism that drives the movable part; and the movable part. A movable portion that supports the light beam from the light beam generating element; and an optical system that focuses the light beam from the light beam generating element on the optical disk surface. An integrated optical head comprising: a photodetector for detecting light from the optical disc; and a control circuit for controlling the drive mechanism according to a signal of a light amount change from the optical disc. 7. An integrated optical head used in at least an optical disk device for reproducing, comprising: a movable part that moves relative to the optical disk device; a drive mechanism that drives the movable part; and the movable part. A movable portion that supports the light beam from the light beam generating element; and an optical system that focuses the light beam from the light beam generating element on the optical disk surface. And a photodetector for detecting light from the optical disc, wherein the support member transmits an electric signal from the photodetector. 8. An integrated optical head used in at least an optical disk device for reproduction, comprising: a movable part that moves relative to the optical disk device; a drive mechanism that drives the movable part; and the movable part. A movable portion that supports the light beam from the light beam generating element; and an optical system that focuses the light beam from the light beam generating element on the optical disk surface. A photodetector for detecting light from the optical disc,
An error detection circuit that generates a signal for controlling the drive unit from a signal of a light amount change from the optical disc, wherein the support member transmits an electric signal from the error detection circuit. Body type optical head. 9. An integrated optical head used in at least an optical disk device for reproduction, comprising: a movable part that moves relative to the optical disk device; a drive mechanism that drives the movable part; and the movable part. A movable portion that supports the light beam from the light beam generating element; and an optical system that focuses the light beam from the light beam generating element on the optical disk surface. And a photodetector for detecting light from the optical disc, wherein the supporting member transmits an electric signal for controlling the driving unit. 10. An integrated optical head, which is used in an optical disk device for recording / reproducing and receives a control signal for controlling a light beam and a data signal from the outside at the time of recording, which is relative to the optical disk device. A movable part that moves dynamically, a drive mechanism that drives the movable part, and a fixed part that supports the movable part through a support member, and the movable part includes an optical beam generating element and the light beam. An optical system for converging the light beam from the beam generating element on the optical disk surface, and a photodetector for detecting the light from the optical disk,
An information processing circuit for control, the support member transmits a control signal for controlling a light beam generated by the light beam generating element, the information processing circuit for control is from the support member. The optical beam is controlled by the control signal of 1. 11. An integrated optical head used in an optical disc device for recording and reproducing, comprising: a movable part that moves relative to the optical disc device; a drive mechanism that drives the movable part; and the movable part. A movable portion that supports the light beam from the light beam generating element; and an optical system that focuses the light beam from the light beam generating element on the optical disk surface. And a photodetector for detecting light from the optical disc, wherein the support member transmits a data signal to be recorded. 12. An integrated optical head used in an optical disc device for recording and reproducing, comprising: a movable part that moves relative to the optical disc device; a drive mechanism that drives the movable part; and the movable part. A movable portion that supports the light beam from the light beam generating element; and an optical system that focuses the light beam from the light beam generating element on the optical disk surface. A photodetector for detecting light from the optical disc,
A signal switching circuit, the support member transmits a signal for controlling the driving mechanism and a signal for controlling the optical beam generating element in a time division manner, and the signal switching circuit includes the driving mechanism. And an optical beam generating element control signal is separated and output. 13. An integrated optical head used in at least an optical disk device for reproduction, comprising: a movable part that moves relative to the optical disk device; a drive mechanism that drives the movable part; and the movable part. A movable portion that supports the light beam from the light beam generating element and an optical system that focuses the light beam from the light beam generating element on the recording surface of the optical disc. And an optical detector for detecting the light from the optical disc, wherein only the support member connects the movable portion and the fixed portion to each other. 14. Claims 1, 2, 3, 4, 5, 6, 7,
8, 9, 10, 11, 12 or 13, wherein the optical beam generating element is a semiconductor laser, a spindle motor for rotating the optical disk, and An optical disc apparatus comprising: a drive unit having a course actuator for moving a body type optical head in a radial direction of an optical disc; and an information processing circuit for controlling at least the drive unit and performing signal processing.