JP2006351097A - Optical pickup device and optical disk device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical pickup device having stable performance and an optical disk device using the same. <P>SOLUTION: The optical pickup device includes a light emitting element for emitting a laser beam, and a polarized beam splitter having characteristics of roughly fully transmitting the polarized light of a first direction and roughly fully reflecting the polarized light of a second direction orthogonal to the first direction and adapted to transmit a part of the laser beam thereby making it incident as an emitted laser beam on an optical disk and to reflect the remaining laser beam thereby making it incident as a monitored laser beam on a light receiving element. The light emitting element and the polarized beam splitter area arranged to include a predetermined angle difference between the polarizing direction of the laser beam made incident on the polarized beam splitter. Thus, by using the polarized beam splitter having stable characteristics to roughly fully transmitting the polarized light of the first direction and to roughly fully reflect the polarized beam of the second direction, the laser beam from the light emitting element is branched into two. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is suitable for application to an optical pickup device used in an optical disk device.

  Conventionally, in an optical disc apparatus, a light beam of a laser beam emitted from a laser diode of an optical pickup is irradiated onto an optical disc, a reproduction signal is obtained based on a change in the amount of reflected light, and a light beam emitted from the laser diode Is split by a spectroscopic means such as a polarization beam splitter and incident on a light receiving element for detecting the amount of light (referred to as a monitor PD (Photo Diode)), and based on a light amount detection signal output from the monitor PD. The light emission power of the laser diode is controlled to be constant (this control is called APC (Automatic Power Control)).

  Here, the laser light emitted from the laser diode has a minute power fluctuation (laser noise), and there is a problem that a laser noise component is also included in the reproduction signal due to this influence.

  In order to solve such a problem, there is a method of generating an LNC (Laser Noise Cancel) signal corresponding to the laser noise from the output of the monitor PD and canceling the laser noise component of the reproduction signal using the LNC signal.

  In an optical pickup using such a laser noise canceling method, a reproduction PD for generating a reproduction signal and a monitor PD for generating an APC or LNC signal are provided on one light receiving element. There has also been proposed an optical pickup that matches both characteristics and performs better laser noise cancellation (see, for example, Patent Document 1).

  As shown in FIG. 12, the optical pickup 100 has a laser diode 101 as a light source, a collimator lens 102, a polarizing beam splitter 103, a quarter wavelength plate 104, an objective lens 105, a condenser lens 106, and a light receiving element 107. ing. The light receiving element 107 has a reproduction PD 107A for generating a reproduction signal and a monitor PD 107B for generating an APC and LNC signal.

  The polarization beam splitter 103 has a polarization reflection surface 103A and a total reflection surface. The polarization reflecting surface 103A is selected so that it transmits 90% of the P-polarized light and reflects the remaining 10%, and totally reflects the S-polarized light. On the other hand, the total reflection surface 108 reflects light 100% regardless of the polarization plane. The total reflection surface 108 is provided with a slight inclination with respect to a plane perpendicular to the optical path.

  The P-polarized laser light emitted from the laser diode 101 is collimated by the collimator lens 102 and enters the polarization beam splitter 103.

  The polarization reflection surface 103A of the polarization beam splitter 103 reflects 10% of the P-polarized laser light as monitor laser light in the direction of the total reflection surface 108 and transmits the remaining 90% to the quarter-wave plate 104. Make it incident.

  The total reflection surface 108 of the polarization beam splitter 103 totally reflects 10% of the monitor laser light reflected by the polarization reflection surface 103A and makes it incident on the polarization reflection surface 103A again. Since this reflected light is also P-polarized light, the polarization reflection surface 103A transmits 90% of the monitor laser light and enters the monitor PD 107B of the light receiving element 107.

  On the other hand, the quarter-wave plate 104 converts the P-polarized laser light transmitted through the polarization reflecting surface 103 </ b> A into circularly-polarized light and irradiates the optical disc 105 through the objective lens 105. The objective lens 105 receives the reflected laser beam reflected by the optical disc 105 and makes it incident on the quarter-wave plate 104.

  The quarter-wave plate 104 converts the reflected laser light from circularly polarized light to S-polarized light and enters the polarizing beam splitter 103.

  The polarization reflection surface 103 A of the polarization beam splitter 103 totally reflects the reflected laser beam made of S-polarized light and enters the reproduction PD 107 A of the light receiving element 107 through the condenser lens 106.

Thus, in this optical pickup 100, the monitor laser light branched by the polarization reflection surface 103A of the polarization beam splitter 103 is reflected by the total reflection surface 108 and re-enters the polarization reflection surface 103A, whereby the light of the monitor laser light is obtained. The axis and the optical axis of the reflected laser beam from the optical disk 109 are made to substantially coincide with each other so that both are received by one light receiving element 107.
JP-A-2005-004848

  As described above, the polarization reflecting surface 103A of the polarization beam splitter 103 transmits 90% of the P-polarized light and reflects the remaining 10%, so that the laser light from the laser diode 101 is totally reflected in the direction of the optical disk 109. It branches to the direction of the surface 108.

  However, the polarization reflection surface having partial transmission characteristics such as “90% transmission / 10% reflection” of the polarization reflection surface 103A is such that “P-polarized light is totally transmitted and S-polarized light is totally reflected”. Compared to the above, the variation in transmittance is large. For this reason, in the optical pickup 100 having the above-described configuration, the ratio between the light amount of the laser light from the laser diode 101 and the light amount of the laser light branched in the direction of the total reflection surface 108 is different for each optical pickup 100. There's a problem.

  In the optical pickup 100 having the above-described configuration, the monitor laser light passes through the polarization reflection surface 103A of the polarization beam splitter 103 twice (first reflection, second transmission) before entering the monitor PD 107B. At the time of re-transmission when entering the monitor PD 107B from the total reflection surface 108, the polarization reflection surface 103A transmits only 90% of the monitor laser light, so that the amount of the monitor laser light is reduced, and the laser light. There was a problem that it was not possible to use efficiently.

  Further, as described above, since the polarization reflection surface having a partial transmission characteristic has a large variation in transmittance, the monitor laser light passing through the polarization reflection surface 103A twice is affected by the variation in transmittance twice. As a result, there is a problem that the variation in the amount of light of the monitor laser light also increases.

  In addition, the polarization beam splitter 103 described above needs to be installed in parallel light, which causes a problem that the optical pickup becomes large.

  The present invention has been made in consideration of the above points, and intends to propose an optical pickup apparatus having stable performance and an optical disk apparatus using the same.

  In order to solve such a problem, in the present invention, a light emitting element that emits laser light, and substantially all of the polarized light in the first direction are transmitted and polarized in the second direction perpendicular to the first direction. A polarization beam splitter that has a substantially total reflection characteristic and transmits a part of the laser light to be incident on the optical disk as outgoing laser light, and reflects the remainder of the laser light and enters the light receiving element as monitor laser light. The light emitting element and the polarization beam splitter were installed so as to have a predetermined angle difference between the polarization direction of the laser light incident on the polarization beam splitter and the first direction.

  As a result, the laser beam from the light emitting element can be transmitted using a polarization beam splitter having stable characteristics such that the polarized light in the first direction is substantially totally transmitted and the polarized light in the second direction is substantially totally reflected. It can branch into two. In addition, a polarizing beam splitter can be provided in the diverging (condensed) light, whereby the optical pickup can be reduced in size.

  According to the present invention, a light emitting element that emits laser light, and a characteristic that substantially completely transmits polarized light in a first direction and substantially totally reflects polarized light in a second direction perpendicular to the first direction. A polarizing beam splitter that transmits a part of the laser light and makes it incident on the optical disk as an emitted laser light, and reflects the rest of the laser light and makes it incident on the light receiving element as a monitor laser light. By installing the light emitting element and the polarization beam splitter so as to have a predetermined angle difference between the polarization direction of the laser light incident on the polarization beam splitter and the first direction, the polarization in the first direction is substantially all. Splitting the laser light from the light emitting element into two by using a polarization beam splitter that transmits the light and substantially totally reflects the polarized light in the second direction and has stable characteristics. Can, thus, it is possible to realize an optical disc apparatus using an optical pickup device and which has a stable performance.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

(1) Overall Configuration of Optical Disc Device FIG. 1 shows an optical disc device 1 to which the present invention is applied, in which a control unit 2 performs overall control. The control unit 2 controls the motor 3 to rotate the optical disk 4 and controls the optical pickup 6 to irradiate the optical disk 4 with the emitted light beam L1. The optical pickup 6 detects a reflected light beam formed by reflecting the emitted light beam L 1 on the optical disk 4, generates a reproduction signal, and supplies it to the generation processing unit 5. The reproduction processing unit 5 performs predetermined signal processing on the reproduction signal and outputs it to the outside.

(2) Optical Pickup According to First Embodiment FIG. 2 shows a configuration of the optical pickup 6 according to the first embodiment of the present invention. An optical integrated element 7, a collimator lens 8, a quarter wavelength plate 9, The objective lens 10 is mounted on an optical pickup base (not shown) made of an aluminum die cast product (hereinafter referred to as an OP base).

  The optical integrated element 7 is configured by assembling various optical components to a package 11 in which a laser diode 25 as a light emitting element and a rising mirror 26 are embedded and sealed. That is, a light receiving element 12 for obtaining a reproduction signal and various servo error signals from the reflected laser light reflected by the optical disk 4 is attached to the upper surface of the package 11, and a mold composite having a diffraction grating 14A and a hologram 14B. An element 14 is attached via a spacer 13.

  Furthermore, a laminated prism 20 configured by combining a plurality of prisms is attached to the upper surface of the mold composite element 14, and monitor laser light described later is reflected and converged on the side of the laminated prism 20. A condensing mirror 17 is provided.

  The condensing mirror 17 is an internal reflection type concave mirror having a concave reflecting surface on the inner surface, and can obtain a large convergence rate with a small size as compared with the case of using a convex lens, and also due to component tolerance, assembly error, etc. Variation in convergence can be reduced. If the radius of curvature of the condensing mirror 17 in this case is set to about 1.5 to 1.7 times the optical distance from the laser emission point to the condensing mirror 17, the monitor laser light can be converged satisfactorily. .

  The package 11 reflects the laser light emitted from the laser diode 25 upward by the rising mirror 26 and enters the PBS (polarized beam splitter) 21 </ b> A of the laminated prism 21 through an emission hole (not shown) and the mold composite element 14.

  This PBS 21A transmits substantially 100% of P-polarized light as polarized light in the first direction (total transmission) and reflects 100% of S-polarized light as polarized light in the second direction (total reflection). A polarization reflecting surface. On the other hand, the laser diode 25 and the rising mirror 26 are installed so that the laser light emitted from the package 11 has a polarization direction rotated by a predetermined angle (in this case, 20 °) with respect to the P polarization direction of the PBS 21A. The direction is selected (Figure 3).

  As described above, since there is an angle difference of 20 ° between the P polarization direction of the PBS 21A as the first direction (referred to as the polarization reference direction) and the polarization direction of the laser light, the PBS 21A is the P polarization in the laser light. The component (about 88%) is transmitted, and is incident on the collimator lens 8 as emitted laser light.

  The collimator lens 8 converts the emitted laser light transmitted through the PBS 21A from divergent light to parallel light, and further converts the light from P-polarized light to circularly-polarized light by the quarter wavelength plate 9, and enters the objective lens 10. The objective lens 10 condenses the emitted laser light and irradiates the optical disc 4 with it.

  Further, the objective lens 10 condenses the reflected laser beam formed by irradiating the outgoing laser beam on the optical disc 4, and further converts the circularly polarized light into S polarized light by the quarter wavelength plate 9 and makes it incident on the collimator lens 8. The collimator lens 8 converts the reflected laser light from parallel light into convergent light and enters the laminated prism 20.

  As shown in FIG. 4A, the PBS 21A of the laminated prism 20 reflects 100% of the reflected laser light made of S-polarized light from the collimator lens 8 and makes it incident on the half mirror 21B. The half mirror 21B reflects a part of the reflected laser light from the PBS 21A by 90 degrees and enters the hologram 14B, and converts the + 1st order light and the −1st order light diffracted by the hologram 14B into the focus error of the light receiving element 12. The light is incident on the signal PD 12A (FIG. 5). The half mirror 21B transmits the remainder of the reflected laser light and makes it incident on the reproduction PD 12B of the light receiving element 12 through the total reflection mirror 21C.

  The light receiving element 12 generates a focus error signal based on the reflected laser light incident on the focus error signal PD 12A, and generates a reproduction signal and a tracking error signal based on the reflected laser light incident on the reproduction PD 12B. This is supplied to the control unit 2 (FIG. 1) of the optical disc apparatus 1.

  Further, as shown in FIG. 4B, the PBS 21A of the laminated prism 21 reflects the S-polarized component (about 12%) in the emitted laser light from the package 11, and collects the mirror 17 as monitor laser light composed of S-polarized light. To enter. The condensing mirror 17 reflects the monitor laser light, converts it into convergent light, and reenters the PBS 21A. Here, since the optical axis of the collecting mirror 17 is slightly inclined with respect to the optical axis of the PBS 21A, the monitor laser light reflected by the collecting mirror 17 has a slight angle with respect to the PBS 21A. Incident.

  Then, the PBS 21A totally reflects the monitor laser light according to its polarization plane (S-polarized light) and makes it incident on the monitor PD 12C (FIG. 5) of the light receiving element 12. The light receiving element 12 generates an APC signal and an LNC signal based on the amount of monitor laser light incident on the monitor PD 12C, and supplies them to the control unit 2 (FIG. 1) of the optical disc apparatus 1.

  As described above, the optical pickup 6 detects reflected laser light and monitor laser light with the same light receiving element 12 to generate various signals, thereby reducing the number of components, miniaturizing the optical integrated element 7 and the optical pickup 6, Effects such as improved laser noise cancellation characteristics can be obtained.

  In the above configuration, the optical pickup 6 causes the laser light emitted from the laser diode 25 to transmit the P-polarized light and totally reflect the S-polarized light, and the polarization direction of the optical pick-up 6 is relative to the polarization reference direction of the PBS 21A. Incident light is incident at an angle of 20 °.

  The PBS 21A transmits about 88% of the laser light as P-polarized outgoing laser light, guides it to the optical disk 4, and totally reflects the reflected laser light made of S-polarized light reflected by the optical disk 4, thereby half-mirror 21B and total reflection. The light is incident on the light receiving element 12 through the mirror 21C. The PBS 21 </ b> A reflects about 12% of the laser light as S-polarized monitor laser light, and further totally reflects the monitor laser light reflected by the condenser mirror 17 and guides it to the light receiving element 12.

  In this way, the optical pickup 6 emits light using a polarization reflecting surface that “permeates P-polarized light and totally reflects S-polarized light” by allowing the laser light to enter the PBS 21A at an angle in the polarization direction. The laser beam and the monitor laser beam can be branched.

  Such a polarization reflecting surface that “totally transmits P-polarized light and totally reflects S-polarized light” has a transmittance higher than that of a polarized light reflecting surface having partial transmission characteristics used in the conventional optical pickup 100 (FIG. 12). Since there is little variation, the ratio of the emitted laser light and the monitor laser light in each optical pickup 6 can be stabilized, and consequently the performance of the optical pickup 6 can be stabilized.

  Since the optical pickup 6 uses the PBS 21A that “totally transmits P-polarized light and totally reflects S-polarized light”, the PBS 21A reflects the total amount of reflected laser light and monitor laser light that are respectively S-polarized light. Since it can enter the light receiving element 12, all of the laser light emitted from the laser diode 25 can be used effectively. By improving the utilization efficiency of the laser beam, it is possible to realize a reduction in output and a long life of the laser diode 25, reduction in power consumption and heat generation, miniaturization of the optical integrated element and the optical pickup 6, and the like.

  The optical pickup 6 divides the monitor laser light from the laser that is divergent light before being collimated by the collimator lens 8, condenses it as it is by the condenser mirror 17, and enters the light receiving element 12. Therefore, the monitor laser beam can be handled inside the optical integrated element 7, whereby the optical integrated element 7 and the optical pickup 6 can be reduced in size, and the optical axis adjustment of the optical pickup 6 in the manufacture can be simplified. There is also an advantage.

  That is, when the optical integrated element 7 is manufactured, if the laser diode 25, the light receiving element 12, the mold composite element 14, the laminated prism 20, and the condenser mirror 17 are fixed and integrated within the required accuracy, the optical pickup 6 When performing the optical axis adjustment, the optical axis adjustment for the monitor laser light is completed only by aligning the lens system and the optical integrated element 7 based on the reflected laser light.

  According to the above configuration, by providing a predetermined angle difference between the polarization direction of the laser light incident on the PBS 21 and the polarization reference direction of the PBS 21A, the “P-polarized light is totally transmitted and S-polarized light is obtained. The PBS 21A can be configured by using a polarization reflecting surface that is “totally reflected”, whereby the performance of the optical pickup 6 can be stabilized.

  In the above-described embodiment, the inner concave mirror is used as the condensing mirror 17. However, the present invention is not limited to this, and the optical integrated element 30 shown in FIG. As described above, a condensing mirror 31 formed of a surface concave mirror may be used.

  In the condensing mirror 17 formed of an inner concave mirror, a coating for preventing surface reflection or the like is required on the surface (incident surface) opposite to the reflecting surface. Since the laser beam passes through the inside of the condenser mirror 17, the loss of the monitor laser beam also occurs. However, the condenser mirror 31 formed of a surface concave mirror does not have these losses, and the use efficiency of the laser beam is improved. This can be further improved.

  Furthermore, in the above-described embodiment, the installation direction of the laser diode 25 and the rising mirror 26 is selected so that a predetermined angle difference is formed between the polarization direction of the laser light incident on the PBS 21 and the polarization reference direction of the PBS 21A. However, the present invention is not limited to this, and the polarization direction of the laser light is rotated between the laser diode 25 and the composite prism 20, and the angle between the polarization direction of the laser light incident on the PBS 21 and the polarization reference direction of the PBS 21A. A difference may be provided.

  That is, the optical integrated element 40 in FIG. 7 shown with the same reference numerals corresponding to those in FIG. 3 has a half-wave plate 41 in the laser light emitting part of the package 11, and this half-wavelength By rotating the plate 41, the polarization direction of the laser light incident on the PBS 21 can be changed. Thereby, in the optical integrated element 40, the installation direction of the laser diode 25 and the rising mirror 26 can be freely set, which is an advantage in designing the package 11.

(3) Optical Pickup According to Second Embodiment Next, an optical pickup according to a second embodiment of the present invention will be described. Since the optical pickup of the second embodiment is the same as the optical pickup 6 of the first embodiment shown in FIG. 2 except for the configuration of the optical integrated element, the description of the entire optical pickup is omitted.

  In FIG. 8, in which the same reference numerals are assigned to the corresponding parts to FIG. 3, reference numeral 50 denotes an optical integrated element used in the optical pickup of the second embodiment of the present invention, which does not have the reflecting mirror 17, 3 has the same structure as that of the optical integrated element 7 in FIG. 3 except that a sub-prism 51 is provided between the package 11 and the mold composite element 14 and the configuration of the light receiving element 52 is different.

  The sub-prism 51 includes a PBS 51A having the same characteristics as the PBS 21A of the composite prism 20 “total transmission of P-polarized light and total reflection of S-polarized light” and a total reflection mirror 51B. In the optical integrated device 50, the polarization reference direction of the PBS 51A of the sub-prism 51 and the polarization reference direction of the PBS 21A of the composite prism 20 coincide with each other, and the polarization reference direction and the package 11 are the same as in the first embodiment. An angle difference of 20 ° is provided with respect to the polarization direction of the emitted laser light.

  Laser light emitted from the package 11 first enters the PBS 51 </ b> A of the sub-prism 51. As shown in FIG. 8A, the PBS 51A transmits the P-polarized component (about 88%) in the laser beam and enters the PBS 21A of the composite prism 20 as an emitted laser beam. The PBS 21A totally transmits the outgoing laser beam composed of P-polarized light according to its polarization plane, and irradiates the optical disc through a collimator lens, a quarter-wave plate and an objective lens (not shown).

  Then, the PBS 21A totally reflects the S-polarized reflected laser light from the optical disk in accordance with the polarization plane, and a part of the reflected laser light passes through the half mirror 21B to the focus error signal PD 52A (FIG. 9). Make it incident. The half mirror 21B transmits the remainder of the reflected laser light and makes it incident on the reproduction PD 52B of the light receiving element 52 through the total reflection mirror 21C.

  The light receiving element 52 generates a focus error signal based on the reflected laser light incident on the focus error signal PD 52A, and generates a reproduction signal and a tracking error signal based on the reflected laser light incident on the reproduction PD 52B. This is supplied to a control unit (not shown) of the optical disc apparatus.

  Further, as shown in FIG. 8B, the PBS 51A of the sub-prism 51 reflects the S-polarized component (about 12%) in the laser light, and the monitor PD 52C of the light receiving element 52 through the total reflection mirror 51B (FIG. 9). To enter. The light receiving element 52 generates an APC signal and an LNC signal based on the amount of monitor laser light incident on the monitor PD 52C, and supplies these to the control unit of the optical disc apparatus.

  In the above configuration, the optical integrated element 50 branches the monitor laser light by the sub-prism 51 at a position immediately after the emission of the laser light from the package 11 and makes it incident on the monitor PD 52C as divergent light. As a result, a reflection mirror for returning the monitor laser light to the PBS of the composite prism becomes unnecessary, and the entire optical integrated element 50 can be further reduced in size.

  Further, as shown in FIG. 9, the light receiving element 52 can be provided with a monitor PD 52C on the axis of the focus error signal PD 52A and the reproduction PD 52B, and therefore, compared with the light receiving element 12 of the first embodiment shown in FIG. Thus, the width of the optical composite element 50 can be reduced.

  In the above-described embodiment, the sub-prism 51 having the PBS 51A and the total reflection mirror 51B is used. However, the sub-prism 61 having only the PBS 61A as in the optical integrated element 60 shown in FIG. Good.

  In this case, the sub-prism 61 does not require a reflection mirror for returning the light reflected by the PBS 61A to the light receiving element 12, and the entire optical integrated element 50 can be further reduced in size.

  The sub-prism 61 causes the monitor laser light reflected by the PBS 61 </ b> A to be refracted by the side surface 61 </ b> B of the sub-prism 61 and enter the light receiving element 52. In this case, there is an advantage that the structure of the sub-prism 61 is simplified.

(4) Other Embodiments In the first and second embodiments described above, the polarization direction of the laser light from the laser diode makes an angle difference of 20 ° with respect to the polarization reference direction of the PBS. However, the present invention is not limited to this, and the angle difference may be changed as appropriate in accordance with the required ratio between the emitted laser beam and the monitor laser beam.

  In the first and second embodiments described above, the laser light from the laser diode is raised in the direction of the optical disk by the rising mirror, and the polarization direction of the laser light is predetermined with respect to the polarization reference direction of the PBS. However, the present invention is not limited to this, and as shown in FIG. 11A, the laser emitted from the laser diode 25 is selected. The light may be emitted from the package 11 as it is. In this case, as shown in FIG. 11B, by providing an appropriate angle to the heat sink 27 that holds the laser diode 25, the polarization direction of the laser light makes a predetermined angle difference with respect to the polarization reference direction of the PBS. A laser diode 25 can be installed.

  The present invention can be applied to various optical disc apparatuses such as a CD (Compact Disc), a DVD (Digital Versatile Disc), and a Blu-ray Disc.

It is a block diagram which shows the whole structure of an optical disk device. It is a basic diagram which shows the structure of the optical pick-up of this invention. It is a basic diagram with which it uses for description of the polarization direction of a laser beam and PBS. It is a basic diagram which shows the optical integrated element of 1st Embodiment. It is a basic diagram which shows the structure of the light receiving element of 1st Embodiment. It is a basic diagram which shows the inside of the optical integrated element using a surface concave mirror. It is a perspective view which shows the structure of the package of other embodiment. It is a basic diagram which shows the optical integrated element of 2nd Embodiment. It is a basic diagram which shows the light receiving element of 2nd Embodiment. It is a basic diagram which shows the optical integrated element using the sub prism which has only PBS. It is a basic diagram which shows the installation method of the laser diode by other embodiment. It is a basic diagram which shows the structure of the conventional optical pick-up.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Optical disk apparatus, 2 ... Control part, 3 ... Motor, 4 ... Optical disk, 5 ... Reproduction processing part, 6 ... Optical pick-up, 7, 30, 40, 50, 60 ... Optical integrated element, 8 ... Collimator lens, 9 ... 1/4 wavelength plate, 10 ... Objective lens, 11, 31 ... Package, 12 ... Light receiving element, 13 ... Spacer, 14 ... Mold composite element, 17, 31 ... Reflector mirror, 20 ... Laminated prism, 21A ... PBS, 21B ... Half mirror, 21C ... Total reflection mirror, 25 ... Laser diode, 26 ... Rise mirror, 51 ... Sub prism.

Claims (5)

A light emitting element that emits laser light;
The polarized light in the first direction is substantially totally transmitted and the polarized light in the second direction perpendicular to the first direction is substantially totally reflected, and a part of the laser beam is transmitted and emitted. A polarization beam splitter that is incident on an optical disk as laser light, reflects the remainder of the laser light, and is incident on a light receiving element as monitor laser light,
The light emitting element and the polarization beam splitter are installed so as to have a predetermined angle difference between the polarization direction of the laser light incident on the polarization beam splitter and the first direction. Optical pickup device. 2. The optical pickup device according to claim 1, wherein the polarization beam splitter reflects reflected laser light obtained by reflecting the emitted laser light by the optical disc and makes the light incident on the light receiving element. 3. A mirror that reflects the monitor laser light reflected by the polarizing beam splitter and re-enters the polarizing beam splitter;
The optical pickup device according to claim 1, wherein the polarization beam splitter causes the monitor laser light reflected by the mirror to be substantially totally reflected and incident on the light receiving element. The optical pickup device according to claim 4, wherein the mirror condenses the monitor laser light and makes it incident on the light receiving element. In an optical disc apparatus having an optical pickup device,
The optical pickup device is
A light emitting element that emits laser light;
The polarized light in the first direction is substantially totally transmitted and the polarized light in the second direction perpendicular to the first direction is substantially totally reflected, and a part of the laser beam is transmitted and emitted. A polarization beam splitter that is incident on an optical disk as laser light, reflects the remainder of the laser light, and is incident on a light receiving element as monitor laser light,
The light emitting element and the polarization beam splitter are installed so as to have a predetermined angle difference between the polarization direction of the laser light incident on the polarization beam splitter and the first direction. Optical disk device.

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