JP2003248957A - Optical pickup apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To properly reproduce different kinds of optical recording medium. <P>SOLUTION: In this optical pickup apparatus, a laser coupler 11 irradiates a DVD 100 or a CD 200 with light at a wavelength of about 785 nm or light at a wavelength of about 655 nm, light returning from the DVD 100 is received by the laser coupler 11 to detect a focus error signal, a tracking error signal and an RF signal, light returning from the CD 200 is received by the laser coupler 11 to detect the focus error signal, and a part of the light returning from the CD 200 is reflected by a beam splitter 13 and received by a PDIC 16 to detect the tracking error signal and the RF signal. <P>COPYRIGHT: (C)2003,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] [0001] The present invention relates to an optical recording medium,
While being reflected by the optical recording medium.
Equipped with an integrated optical element that receives the returning light
Write and read information signals to and from optical recording media
The present invention relates to an optical pickup device for performing the operation. [0002] 2. Description of the Related Art Incompatible optical data of different formats.
Various discs have been proposed. For example, so-called DVD
(Digital Versatile Disk) is a so-called CD (Compac
t Disk), the recording track is narrower than
Density recording is possible. A light spot formed on a recording track
A laser that forms this light spot, where d is the spot diameter
When the wavelength of light is λ and the numerical aperture of the objective lens is NA,
The spot diameter d is determined by setting the wavelength λ of the laser beam to the aperture of the objective lens.
It is proportional to the value divided by the number NA. [0004] For example, in a DVD, the track pitch
In order to obtain an appropriate spot diameter, optical specifications
A light source that emits laser light with a length λ of about 650 nm is required.
It is required that the numerical aperture of the objective lens be 0.6.
Have been. On the other hand, in the case of CD, the wavelength is around 780 nm.
There is a need for a light source that emits laser light. Also,
Data can be rewritten using an organic dye film for the recording layer.
The so-called CD-R has a wavelength of about 780 nm.
Only to obtain a reflectance of 70% or more similar to a CD.
Format. [0005] As described above, the compatibility of the formats is different.
The same optical disk system for no DVD and CD
In order to reproduce data in the
It is necessary to provide a light source. For example, format differences
Light sources corresponding to different incompatible optical discs
By having two optical pickup devices having
For each optical disk in the same optical disk system
It is possible to write and read information signals. As an optical pickup, Japanese Patent Laid-Open No.
01-126302 and JP-A-2001-1262
No. 89, different wavelengths of light are emitted at different emission points
Some have a two-wavelength laser coupler that emits light from a laser. [0007] However, the above two waves
Optical pickup devices that use long laser couplers
CD-R / RW (Compact
Play an optical disc such as Disk-Recordable / Rewritable)
When reading, there is a problem that reading becomes unstable.
This is because an optical disk such as a CD-R / RW is
Good playback with tracking method
That is because it is. Accordingly, the present invention has been made in view of the above-described circumstances.
Recording and playback even after miniaturization.
Equipped with an integrated optical element capable of high accuracy, CD-
Optical pick-up for stabilizing reading of optical discs such as R / RW
It is an object to provide a backup device. [0009] In order to achieve the above object,
The optical pickup device according to the present invention has a first optical
A first laser beam having a wavelength corresponding to the recording medium
The light emitting point of the first optical recording medium has a format different from that of the first optical recording medium.
Second laser light having a wavelength corresponding to the second optical recording medium
A light source having a second light emitting point for emitting light, and a first optical
Receives the first return light reflected and returned by the recording medium
A first light receiving unit, a second light receiving unit, and a second optical recording medium
The second receiving the second return light reflected and returned by the body
A first light receiving element having three light receiving units and a fourth light receiving unit
And a first return light beam, which is disposed on the first light receiving element,
And the second return light are incident from the incident surface and the incident surface.
When a part of the first return light is incident on the first light receiving portion,
The second part which reflects other parts or is incident from the entrance surface
A part of the return light of
Semi-transmissive surface that reflects the portion of
The other part of the return light of No. 1 is reflected and incident on the second light receiving portion.
Or other reflection of the second return light reflected on the transflective surface.
A reflecting surface for reflecting a portion to be incident on the fourth light receiving portion.
Integrated optical element with integrated optical elements
And the first laser beam emitted from the integrated optical element.
Or a second ray emitted from the integrated optical element.
The light is diffracted and split into 0th order light and ± 1st order light and transmitted.
Diffraction element, and a first laser beam transmitted through the diffraction element or
The second laser beam is transmitted to the first optical recording medium or the second optical recording medium.
Condenser lens for condensing light on the recording medium, diffraction element and condensing lens
And a predetermined amount of the second return light
Reflected by the beam splitter and the beam splitter
And a second light receiving element for receiving the second return light.
And features. An optical pickup having such a configuration.
The device is incident on the entrance surface at a different angle of incidence than the first return light
The second return light to be transmitted to the first
When the third and fourth light receiving portions of the light receiving element sequentially receive light,
In both cases, part of the second return light is reflected by the beam splitter
Then, the light is received by the second light receiving element. [0011] Embodiments of the present invention will be described below.
This will be described in detail with reference to the drawings. This embodiment is based on the book
The invention is recorded on two types of optical discs with different formats.
Two-wavelength optical system to read recorded data
This is applied to an optical pickup device to be configured. This
Optical pickup devices, for example,
Provided for the optical disk system that plays back the data
Have been. The optical pickup device is shown in FIGS.
As described above, housed in a package 10 and emit laser light
And receives the return light reflected back from the optical disk.
A laser coupler 11 which is an integrated optical element;
Grating into which laser light emitted from laser 11 is incident
Laser beam transmitted through the grating 12
The beam splitter 13 to be irradiated and the beam splitter 1
A collimator 14 into which the laser light transmitted through 3 is incident;
Laser light transmitted through the collimator 14 and converted into parallel light
Is focused on the first optical disk or the second optical disk
The objective lens 15 and the return light beam from the first optical disc
Receiving the return light reflected by the beam splitter 13
PDIC (Photo Detector Integrated Circuit) 16
And Here, the collimator 14 and the objective lens 15
Is to focus the laser light on the signal recording surface of the optical disc
It constitutes a condenser lens unit. Also, the first optical disk
Is, for example, a so-called DVD, and a second optical disc.
Is in a format different from the first optical disc
For example, a so-called CD or CD-R / RW
You. Hereinafter, the first optical disc is referred to as a DVD 100, and the second optical disc is referred to as a DVD 100.
The optical disk is described as CD 200, but is not limited to this.
Needless to say, it is not specified. This optical pickup device is a laser coupler.
11 to the wavelength corresponding to DVD100 or CD200
Return light emitted from laser light and reflected by DVD 100
Is received by the laser coupler 11 or the CD 20
The return light reflected at 0 is received by the laser coupler 11 and
This is performed in the PDIC 16. The laser coupler 11 is specifically shown in FIG.
And as shown in FIG.
Substrate 21, light source unit 22, micro prism 23,
A light receiving element 24 is provided. The laser coupler 11 is located at the bottom of the package 10.
It is placed on a plate 25. And the laser coupler 11
The signal detected by the light receiving element 24 is
A signal processing circuit for outputting is formed. This message
Optical disk system based on the signal output from the signal processing circuit.
The stem performs various servo processing, information reproduction, and the like. The light emitting section 22 for emitting a laser beam is a semiconductor
Substrate 26 and semiconductor disposed on semiconductor substrate 26
And a laser 27. The semiconductor laser 27 is a laser having a first wavelength.
A first light emitting point 27a for emitting light, and a light having a wavelength different from the first wavelength.
Emitting point 27b for emitting a laser beam of a second wavelength
And The first light emitting point 27a is a first light
A disk for irradiating the DVD 100
The second light emitting point 27b is a second light source.
A laser for irradiating the CD 200
The light source. Here, the first wavelength λ is approximately 655 nm.
The second wavelength λ is approximately 785 nm. In the semiconductor laser 27, the first light emitting point
27a and the second light-emitting point 27b are
3 so that they are opposed to each other.
3 are arranged substantially parallel to the width direction. And
From the first light-emitting point 27a, the oblique
The laser beam is emitted so that it is reflected vertically on the surface 23a.
Fired. In addition, the first light emission point 27b
The optical axis of the DVD laser light emitted from the light spot 27a
Laser for CD with optical axis having a predetermined angle to it
Light is emitted. Specifically, the laser light for CD is oblique.
As it proceeds to the surface 23a, from the first light emitting point 27a for DVD
DVD laser when the laser light of
Emitted from the second light emitting point 27b so as to approach the light.
You. The first light emitting point 27a of the semiconductor laser 27,
Laser light emitted from the second light emitting point 27b is incident
The microprisms 23 are obliquely used as laser light incident surfaces.
Shape having surface 23a, top surface 23b, and bottom surface 23c
It has been. The top surface 23b and the bottom surface 23c are substantially parallel
The inclined surface 23a is inclined with respect to the upper surface 23b.
It is formed. This micro prism 23
Direct laser light emitted from optical section 22 to optical disc
Reflected and returned from the optical disk
The optical element guides light to the light receiving element 20. The slope 23 a is a laser beam from the light emitting section 22.
Is reflected toward the grating 12 and D
Return light from VD100 or CD200
It is formed so as to be transmitted through the mechanism 23. concrete
Then, the laser light from the light emitting section 22 is reflected on the slope 23a.
And from DVD100 or CD200
To allow the return light to pass through the microprism 23,
A half mirror is formed. Also, on the upper surface 23b
Has a reflective film. And on the bottom surface 23c
Has a semi-permeable membrane. Specifically, a semi-permeable membrane
Means that the return light incident from the slope 23a travels first
So as to be located on the first and third light receiving sections 31 and 33
It is partially formed on the bottom surface 23c. Here, the slope 23a is a micro prism.
23 is the first light emission of the semiconductor laser 27.
About laser light for DVD emitted from the point 27a
It is formed to be vertical. Below, semiconductor laser
The emission direction of the laser light from the first light emitting point 27a of the
Called the Y-axis direction. The slope 23a is in a direction perpendicular to the width direction.
Are the first and second light emitting points 24a, 24a of the semiconductor laser 27.
The laser light for DVD and CD emitted from 24b
The laser beam L is reflected substantially vertically, as shown in FIG.
_outIs formed to face the grating 12
I have. Hereinafter, the laser light reflected by the slope 23a
The direction heading is called the Z-axis direction. It should be noted that the Z-axis direction
The direction that is straight and perpendicular to the Y-axis direction is called the X-axis direction.
U. As shown in FIG. 5, the light receiving element 24 has a DV
D100 receives the return light reflected on the signal recording surface 100a.
First and second light receiving sections 31 and 32 that emit light;
Receiving the return light reflected by the signal recording surface 200a
3rd and 4th light receiving parts 33 and 34 are provided. The first and second light receiving sections 31, 32 are arranged on the Y-axis.
Are arranged in the same direction and are arranged close to each other. No.
One light receiving unit 31 is divided into four parts in the X-axis direction,
The first to eighth light receiving areas 3 are divided into two in the axial direction.
1₁, 31₂, 31₃, 31 ₄, 31₅, 31₆, 31
₇, 31₈Is formed. Also, the second light receiving unit 32
Is divided into four parts in the X-axis direction to form first to fourth light receiving areas 3.
2₁, 32₂, 32₃, 32₄Is formed. The third and fourth light receiving sections 33, 34
Are arranged in the same direction and are arranged close to each other. No.
The third light receiving unit 33 is divided into four parts in the X-axis direction,
4 light receiving areas 33₁, 33₂, 33₃, 33₄Form
ing. Further, the fourth light receiving unit 34 is divided into four parts in the X-axis direction.
The first to fourth light receiving areas 34₁, 34₂, 3
4 ₃, 34₄Is formed. The first to fourth light receiving sections 31, 3 as described above
A light receiving element 24 composed of 2, 33, 34 is formed.
A microprism 23 is mounted on a substrate 21.
Thereby, it is formed on the bottom surface 23c of the micro prism 23.
The semi-transmissive film is disposed on the light receiving element 24,
Further, the upper surface 23b on which the reflection film is formed is
24 is positioned substantially parallel to the position. The grating 12 has wavelength selectivity.
Diffractive element, and a laser beam having a wavelength of about 655 nm
90% or more of the next light is transmitted, and ± 1st or less light can be almost ignored
So that it only transmits through Also gray
Ting 12 is a zero-order laser beam having a wavelength of about 785 nm.
Approximately 70% of light is transmitted, and ± 1 order light is a so-called 3 beam
Level of light that satisfies the tracking servo of the system, example
For example, about 10% is transmitted. The beam splitter 13 is, for example, a prism
Are bonded to each other, and are substantially formed by the reflection surface 13a.
It reflects part of the laser light with a wavelength of 655 nm.
Have been. The collimator 14 includes a beam splitter 13
The laser beam transmitted through the objective lens 15
Is a lens provided to be incident on the lens. The objective lens 15 transmits through the collimator 14
The incident surface 15a on which the laser light is incident, and the DVD 1
00 or CD200 and emits laser light.
Projection surface 15b. The objective lens 15 is provided with an actuator (not shown).
Attached to the tutor. The objective lens 15 is
The optical axis direction, which is the Z-axis direction, and the optical
Moveable in the disk radial direction, that is, in the tracking direction
It has been. The PDIC 16, as shown in FIG.
And a signal detected by the light receiving element 40.
A signal processing circuit for outputting is formed. This message
Optical disk system based on the signal output from the signal processing circuit.
The stem performs various servo processing and information reproduction. The light receiving element 40 is a signal recording surface of the CD 200.
200a, reflected by the beam splitter 13
First to third light receiving units 41 and 42 for receiving the returned light,
43. First to third light receiving sections 41, 42, 43
Are arranged in the track direction of the CD 200, and are close to each other.
Has been arranged. The first light receiving unit 41 is a CD 20
0 in the track direction and the radial direction
The first to fourth light receiving areas 41 ₁, 41₂, 41₃,
41₄have. Light provided with such an optical pickup device
The disk system is a diagram for rotating the optical disk.
No rotating operation means. The rotation operation means is mounted
The rotated DVD 100 or CD 200 is rotated. In the following, the optical pickup device is a laser camera.
Laser light on DVD100 or CD200 by plastic 11
And the laser coupler 11 and the PDIC 16
Is reflected by the DVD 100 or CD 200
The process until the return light is received will be described. The laser light emitted from the light emitting section 22 is
The light is reflected by the slope 23 a of the micro prism 23. This
Here, when the DVD 100 is mounted, the light emitting unit
22 having a wavelength of about 655 nm from the first emission point 27a.
Laser light is emitted and CD200 is mounted
Is approximately 785 nm from the second light emitting point 27 b of the light emitting section 22.
Is emitted. As shown in FIG. 1 and FIG.
Laser beam L reflected by the slope 23a of the prism 23
_outIs transmitted through the upper surface 28 of the package 10 and
Passing through the rating 12 and the beam splitter 13,
The light is collimated by the collimator 14,
Incident. The upper surface 28 of the package 10 is, for example,
It is formed of a glass plate material. Here, the inclined surface 23 of the micro prism 23
Laser light L for CD reflected from a _CDHas its optical axis
Laser light L for DVD_DVDOf the optical axis of
Laser light L for D_DVDHas a slight angle to the optical axis of
It has become something. Reflected on the inclined surface 23a of the microprism 23
The emitted laser light is a laser light L for CD._CDIf it is
In addition, it is divided into 0 order light and ± 1 order light by diffraction action,
Approximately 70% of the 0th order light and approximately 10% of the ± 1st order light respectively.
Then, the light enters the beam splitter 13. Also micro
The laser light reflected by the slope 23a of the prism 23 is D
Laser light L for VD_DVD, The diffraction effect
Approximately 90% or more of the 0th order light and ± 1st order light or less can be ignored
And is incident on the beam splitter 13. Rays divided by the grating 12
The light is transmitted through the beam splitter 13 and the collimator 1
The light is converted into a parallel light by 4 and enters the objective lens 15. The laser light incident on the objective lens 15 is
Of the DVD 100 being rotated by the rotation operation means.
Signal recording surface 100a or signal recording surface 200a of CD 200
Focused on top. At this time, it is detected as described later.
Based on the focus error signal and tracking error signal
Then, the actuator is driven and the objective lens 15
Is finely moved for focusing and tracking
It is. On the signal recording surface 100a of the DVD 100 or
Laser irradiated on signal recording surface 200a of CD 200
Here, the light is reflected and returned as the objective lens 1
5 and the collimator 14, and the beam splitter
13 is incident. Laser light incident on beam splitter 13
Is partially reflected when the light is returned from the CD 200.
Incident on the PDIC 16, and the other parts
Incident on the rating 12 and transmitted through the grating 12
To the slope 23a of the microprism 23. Ma
The laser beam incident on the beam splitter 13 has a DV
When returning light from D100, beam splitter
13 and is incident on the grating 12,
Through the mirror 12 and the slope 23 of the microprism 23
Head to a. Here, the slope 23a is
Because it is formed by a half mirror that transmits,
As a result, as shown in FIG.
Light L returning to rhythm 23_inIs incident. Reflected on signal recording surface 200a of CD 200
The returned light (hereinafter, referred to as second return light) is a DV.
Return light reflected on the signal recording surface 100a of D100
(Hereinafter, referred to as first return light).
The light enters the slope 23a depending on the angle of incidence. On the signal recording surface 100a of the DVD 100,
For the first return light that has been emitted, first, the first
The light enters the light unit 31. Specifically, the first light receiving unit 31
Above is formed on the bottom surface 23c of the microprism 23
Of the return light
(50%) is incident on the first light receiving unit 31, and the remaining approximately half
(50%) toward the upper surface 23 b of the microprism 23.
Reflected. To the upper surface 23b of the microprism 23
The other half of the first return light reflected
Reflected by the reflective film on the upper surface 23b of the
The light enters the unit 32. For example, the signal recording surface 100 of the DVD 100
When the laser beam is focused on a
At the time of focusing), as shown in FIG.
Formed on the light receiving portion 31 and the second light receiving portion 32, respectively.
Light spot SP_D1, SP _D2Have the same shape,
When the focus is not focused, the shape
First light spot SP to be formed_D1Shape and second light receiving
Light spot SP formed on portion 32_D2Shape
Will be different. On the other hand, the signal recording surface 200a of the CD 200
The second return light reflected by the first return light is incident on the first return light.
Incident on the slope 23a at an angle of incidence different from the angle
That is, the second return light is the first return light on the slope 2
3a is far from the first return light when it is incident on
The light travels in a zigzag manner and enters the slope 23a. this
As a result, the second return light is incident from the slope 23a.
While moving away from the optical path of the first return light
It proceeds inside the prism 23. In addition, it enters from the slope 23a.
The returning second light is split by the grating 12
0-order light component. More specifically, the second return light is the first received light.
First, the light is incident on the third light receiving section 33 attached to the section 31.
It is. On the third light receiving section 33, the micro prism 23
The antireflection film formed on the bottom surface 23c of the
Approximately half (50%) of the return light is
3 and approximately half (50%) of the remaining
The light is reflected toward the upper surface 23b of the prism 23. Microp
Second return reflected towards upper surface 23b of rhythm 23
The other half of the light is
The first light receiving portion 31 and the third light receiving portion 3 are reflected by the reflection film.
3, the second light receiving unit 32
Incident on the fourth light receiving unit 34 that is arranged away from the
Is done. For example, the signal recording surface 200a of the CD 200
When the laser light is focused on the top of FIG.
As shown in the figure, the third light receiving unit 33 and the fourth light receiving unit 34
Light spot SP formed on each_C1, SP_C2
Are the same in shape and out of focus,
The first light spot SP formed on the third light receiving portion 33
_C1And the second light formed on the fourth light receiving portion 34
Spot SP_C2Is different from the shape. On the other hand, the signal recording surface 200a of the CD 200
A part of the second return light reflected by the
Reflected by the beam splitter 13 and enters the PDIC 16
I do. Specifically, of the part of the second return light,
The 0-order light split by the grating 12 is
First to fourth light receiving areas 41 of light receiving section 41₁, 41₂,
41 ₃, 41₄Light to form a light spot
To achieve. Also, of the part of the second return light,
± 1 order light divided by the ring 12
2 and the third light receiving section 43 respectively. As described above, the signal recording surface 1 of the DVD 100
The return light reflected at 00a
The first and second light receiving sections 31 and 32 of the camera 11
On the other hand, the light is reflected by the signal recording surface 200a of the CD 200.
The third return light of the laser coupler 11 is
And the first light receiving sections 33 and 34 and the first
The light is received by the third light receiving portions 41, 42, and 43.
The optical pickup device is used to detect the return light in the light receiving element.
Focus error signal and tracking based on received light amount
An error signal and a reproduction RF signal are detected. Focus error for DVD 100
The signal FE1, the tracking error signal TE1, and the reproduction R
The F signal (RF1) is as follows. The focus error signal FE1 is given by the following equation (1).
Detected by The formula obtained by this equation (1)
The focus error signal FE1 is obtained by a so-called differential division method (D-
3DF). FE1 = ｛(I₃₁₂+ I₃₁₆+ I₃₁₃+ I₃₁₇) + (I₃₂₁+ I_{32 4} )｝ − ｛(I₃₁₁+ I₃₁₅+ I₃₁₄+ I₃₁₈) + (I₃₂₂+ I₃₂₃)｝ ... (1) Where I₃₁₁, I₃₁₂, I₃₁₃, I₃₁₄, I
₃₁₅, I₃₁₆, I ₃₁₇, I₃₁₈Is the first light receiving section
31st first to eighth light receiving areas 31₁, 31 ₂, 31
₃, 31₄, 31₅, 31₆, 31₇, 31₈Is the amount of received light
Is a light detection signal output in accordance with₃₂₁, I
₃₂₂, I₃₂₃, I₃₂₄Is the first light receiving portion 32
First to fourth light receiving areas 32₁, 32₂, 32₃, 32
₄Is a light detection signal output according to the amount of received light. The tracking error signals TE1 and TE1
The reproduced RF signal (RF1) is given by the equation (2) and the equation (3).
Is detected. Tracking error obtained by equation (2)
Signal TE1 is a so-called DPD (Differential Phase)
 Detection) method. (2) "position" in the formula
“Phase” is the light detected in each light receiving area shifted by a predetermined phase
This indicates a detection signal. TE1 = phase (I₃₁₁+ I₃₁₂+ I₃₁₇+ I₃₁₈) + Phase (I₃₁₅+ I₃₁₆+ I₃₁₃+ I₃₁₄) (2) RF1 = (I₃₁₁+ I₃₁₂+ I₃₁₃+ I₃₁₄+ I₃₁₅+ I₃₁₆+ I ₃₁₇ + I₃₁₈) + (I₃₂₁+ I₃₂₂+ I₃₂₃+ I₃₂₄・ ・ ・ ・ ・ ・ (3) For example, a focus server using a focus error signal
About bo, it is as follows. As shown in FIG.
Laser light is emitted on the signal recording surface 100a of the VD 100.
When focusing, the first light receiving unit 31 and the second
Spots SP respectively formed on the light receiving portions 32
_D1, SP_D2Have the same shape.
The cas error signal FE1 becomes 0. Focus servo
Is set so that the focus error signal FE1 becomes 0.
U. On the other hand, the focus
Error signal FE2, tracking error signal TE2 and
The raw RF signal (RF2) is detected by equations (4) to (6).
Is out. Here, the focus obtained by equation (4)
Error signal FE2 is based on the differential division method (D-3DF).
The tracking error obtained by equation (5)
The error signal TE2 is based on a so-called push-pull method.
It is. FE2 = (I₃₄₂+ I₃₄₃+ I₃₃₁+ I₃₃₄) − (I₃₄₁+ I₃₄₄+ I₃₃₂+ I₃₃₃) ・ ・ ・ (4) TE2 = I₄₃−I₄₂  ... (5) RF2 = (I₄₁₁+ I₄₁₂+ I₄₁₃+ I₄₁₄・ ・ ・ ・ ・ ・ (6) Where I₃₃₁, I₃₃₂, I₃₃₃, I₃₃₄Is
First to fourth light receiving areas 33 of the third light receiving unit 33₁,
33₂, 33₃, 33₄Output light according to the amount of received light
Outgoing signal and I₄₂, I₄₃Is the second of PDIC16
And a light detection signal output by the third light receiving unit according to the amount of received light
And I₄₁₁, I₄₁₂, I₄₁₃, I₄₁₄Is
Each of the first to fourth receiving units of the first light receiving unit 41 of the PDIC 16
Light area 41 ₁, 41₂, 41₃, 41₄Depends on the amount of received light
This is the photodetection signal output by The focus error signal and the
Servo control of optical disk system using racking error signal
By supplying to the control system, focus servo and track
King servo is executed. As described above, the optical pickup device has the D
Laser light of a wavelength corresponding to the format of VD100
Irradiate and record signal of DVD 100 by laser coupler 11
The return light reflected by the recording surface 100a is received, and
Focus error signal, tracking error signal and reproduction R
F signal can be detected, or
Irradiate laser light of a wavelength corresponding to the mat to
CD200 signal recording by plastic 11 and PDIC16
Receives return light reflected by the surface 200a and focuses
Error signal, tracking error signal and reproduced RF signal
Signal can be detected. The optical pickup device is C
When reproducing information from D200, use PDIC16
To perform tracking servo by the three-beam method,
Information can be favorably reproduced from the DR / RW. The optical pickup device is a CD200.
Is reproduced by the laser coupler 11.
Only the error signal is detected, and the
Detects King error signal and RF signal.
The first to third light receiving units 41, 42,
43, and the PDIC 16 is highly accurate.
There is no need for positioning. In addition, PDIC16
Such a pattern of each light receiving section is for a so-called CD.
Therefore, use inexpensive PDIC 16 made for CD.
To reduce the overall cost of the equipment.
Can be. The optical pickup device is a DVD 10
The light emitting unit and the light receiving unit corresponding to 0 and CD200 are integrated.
Since the integrated optical element is
Various signals can be obtained at a time. Incidentally, the optical pickup device
Equipped with an integrated optical element integrating a light emitting unit and a light receiving unit
Is to reduce the number of optical components and provide a low-cost optical system.
Service. In addition, integrated optics are not reliable
high. In the integrated optical element, the light receiving element is provided with a plurality of light receiving elements.
Since it is provided independently for different optical discs,
Optimal design of light receiving element for each optical disc
It is possible. [0066] As described above, the optical pickup according to the present invention is
The integrated optical element corresponds to the second optical recording medium
A second laser beam having a wavelength of
And a part of the return light from the second optical recording medium is
Reflected by the beam splitter and received by the second light receiving element,
By receiving the other part with the integrated optical element, the second optical
The recorded information can be appropriately reproduced from the recording medium.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a configuration of an optical pickup device according to an embodiment of the present invention. FIG. 2 is a block diagram illustrating a configuration of an optical pickup device. FIG. 3 is a cross-sectional view illustrating a configuration of a laser coupler and a package containing the laser coupler of the optical pickup device. FIG. 4 is a plan view showing a configuration of a laser coupler and a package containing the laser coupler of the optical pickup device. FIG. 5 is a plan view showing a light receiving element of a laser coupler, in which a light spot of return light from a DVD is formed on first and second light receiving units. FIG. 6 is a plan view showing a light receiving element of a laser coupler, in which a light spot of return light from a CD is formed on third and fourth light receiving units. FIG. 7 is a plan view showing light receiving elements of a PDIC and showing first to third light receiving units. [Description of Signs] 10 package, 11 laser coupler, 12 grating, 13 beam splitter, 14 collimator, 15 objective lens, 16 PDIC, 21 substrate, 2
2 light emitting section, 23 micro prism, 24 light receiving element, 25 bottom plate, 26 semiconductor substrate, 27 semiconductor laser, 27a first light emitting point, 27b second light emitting point, 3
REFERENCE SIGNS LIST 1 first light receiving section, 32 second light receiving section, 33 third light receiving section, 34 fourth light receiving section, 40 light receiving element, 41
1st light receiving section, 42 2nd light receiving section, 43 3rd light receiving section

Continuation of front page    F term (reference) 5D119 AA01 AA04 AA28 AA40 AA41                       BA01 BB01 CA10 DA05 EA02                       EA03 EC41 EC45 EC47 FA05                       FA08 FA25 FA28 JA22 JA24                       KA04 KA20                 5D789 AA01 AA04 AA28 AA40 AA41                       BA01 BB01 CA10 DA05 EA02                       EA03 EC41 EC45 EC47 FA05                       FA08 FA25 FA28 JA22 JA24                       KA04 KA20

Claims (1)

1. A first light emitting point for emitting a first laser beam having a wavelength corresponding to a first optical recording medium, and a second light emitting point having a format different from that of the first optical recording medium. A light source having a second light emitting point for emitting a second laser beam having a wavelength corresponding to the optical recording medium; and a first light receiving section for receiving the first return light reflected by the first optical recording medium. A first light receiving element including a light receiving unit, a second light receiving unit, and a third light receiving unit and a fourth light receiving unit that receive the second return light reflected by the second optical recording medium; The first return light and the second return light are arranged on the first light receiving element, and an incident surface on which the first return light and the second return light are incident and a part of the first return light incident from the incident surface are converted into the first return light. Of the second return light incident from the incident surface while being incident on the light receiving portion of The second light receiving portion by reflecting the other portion of the first return light reflected on the semi-transmissive surface while reflecting the other portion on the third light receiving portion. And an optical element having a reflecting surface for reflecting another portion of the second return light reflected on the semi-transmissive surface and for entering the fourth light receiving portion. An integrated optical element, wherein the first laser light emitted from the integrated optical element is transmitted, and the second laser light emitted from the integrated optical element is diffracted to form a zero-order light and a ± first-order light. A diffractive element that splits the light into light and transmits the light;
A condensing lens unit for condensing the second laser light on the second optical recording medium, and a condensing lens unit for condensing the second laser light on the second optical recording medium; An optical pickup device comprising: a beam splitter that reflects a predetermined amount of second return light; and a second light receiving element that receives the second return light reflected by the beam splitter.