JP2006127764A - Optical pickup apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical pickup apparatus where an adjustment range of a control gain of an APC circuit can be decreased and a recordable speed can be increased at a low manufacturing cost. <P>SOLUTION: The optical pickup apparatus is provided with first and second light receiving and emitting integrated elements 1, 2. The first light receiving and emitting integrated element 1 emits a laser beam 10 toward an optical disk, and the second light receiving and emitting integrated element 2 emits another laser beam with different wavelength from that of the laser beam 10 to the optical disk. An optical axis 12 of the laser beam 10 of the first light receiving and emitting integrated element 1 and an optical axis of the second light receiving and emitting integrated element are almost aligned with each other at an output side of a DBS 3. A reflecting mirror 74 reflecting laser beams 16 out of an effective region emitted from the first and second light receiving and emitting integrated elements 1, 2 to be guided to a light receiving face 9a of a monitor light detection element 9 is arranged in the vicinity of the DBS 3. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical pickup device that performs at least one of reproduction, erasure, and recording of information on an information recording medium.

  Conventionally, there are optical pickup devices as shown in FIGS. FIG. 14 is a schematic view of the configuration of the optical pickup device as viewed from the side, and FIG. 15 is a schematic view of the configuration of the optical pickup device as viewed from above. 14 and 15, reference numerals 101 and 102 denote first and second integrated light receiving and emitting elements (for example, a hologram laser element and a laser coupler) that emit laser beams having different wavelengths, and 103 denotes a dichroic beam splitter (hereinafter referred to as a dichroic beam splitter). , “DBS”), 104 is a collimating lens, 105 is a rising mirror, 106 is a quarter-wave plate, 107 is an objective lens, 108 is an optical disk, 109 is a light detection element for monitoring, and 110 and 111 are effective areas. The laser beams 112 and 113 are optical axes.

  According to the conventional optical pickup device, as shown in FIG. 14, the laser beam 110 in the effective region emitted from the first light receiving and emitting integrated element 101 passes through the DBS 103 and then becomes a parallel beam by the collimating lens 104. Then, it is bent at a right angle by the rising mirror 105, passes through the quarter-wave plate 106, and is condensed on the recording surface of the optical disk 108 by the objective lens 107. At this time, as shown in FIG. 15, several percent of the effective region laser beam 110 emitted from the first light receiving and emitting integrated element 101 is reflected by the DBS 103 and enters the monitoring light detecting element 109. The monitor light detection element 109 outputs an electrical signal corresponding to the amount of incident laser beam. The electric signal drives an auto power control (hereinafter referred to as “APC”) circuit (not shown). The output of the first light receiving and emitting integrated element 101 is APC controlled by this APC circuit, and the laser beam condensed on the recording surface of the optical disc 108 has an appropriate power.

  The effective region laser beam 111 emitted from the second light emitting / receiving integrated element 102 has several percent transmitted through the DBS 103 and the rest reflected by the DBS 103. The reflected beam reflected by the DBS 103 follows the same path as the laser beam 110 emitted from the first light receiving and emitting integrated element 101 and is condensed on the recording surface of the optical disc 108. On the other hand, the laser beam 111 transmitted through the DBS 103 is incident on the monitoring light detection element 109. As a result, as in the case of the first light receiving / emitting integrated element 101, the output of the second light receiving / emitting integrated element 102 is APC-controlled, and the laser beam condensed on the recording surface of the optical disc 108 has an appropriate power. .

  The reflected beam reflected by the optical disk 108 passes through the objective lens 107, the quarter-wave plate 106, the rising mirror 105, the collimator lens 104, and the DBS 103 in order, and then the first light receiving and emitting integrated element 101 or the first one. 2 Return to the light receiving and emitting integrated element 102. Then, the reflected beam from the optical disk 108 is received by a light receiving element (not shown) in the first light receiving / emitting integrated element 101 or the second light receiving / emitting integrated element 102, and information recorded on the optical disk 108 is recorded. Detected.

  FIG. 16 is a schematic view of another conventional optical pickup device viewed from above. In FIG. 16, the same components as those shown in FIGS. 14 and 15 are denoted by the same reference numerals as those in FIGS. 14 and 15, and description thereof is omitted.

  In the other conventional optical pickup device, the laser beam 114 outside the effective region emitted from the first light receiving / emitting integrated element 101 is received by the monitoring light detecting element 116 and from the second light receiving / emitting integrated element 102. The emitted laser beam 115 outside the effective region is received by the monitoring light detection element 117. The APC circuit (not shown) is driven by the electrical signals from the monitoring light detection elements 116 and 117, and the outputs of the first and second integrated elements 101 and 102 are controlled.

  The DBS 103 has a film for controlling the reflection / transmittance characteristics. This film is difficult to form, and its reflection / transmittance characteristics vary greatly with temperature. Further, the DBS 103 has a large variation from product to product. Therefore, when a plurality of optical pickup devices shown in FIGS. 14 and 15 are manufactured, the light amounts of the laser beams 110 and 111 emitted from the first and second light receiving and emitting integrated elements 101 and 102 and the monitoring light detecting element 109 There is a large variation in relation to the amount of incident laser beam. As a result, there is a problem that the adjustment range of the control gain of the APC circuit must be increased.

  The recording speed of a recordable optical disc such as a CD-R (writable compact disc) or DVD-R (writable digital universal disc) is proportional to the power of the laser beam focused on the recording surface of the optical disc. Higher recording efficiency can be achieved when the laser beam is more efficiently used.

  14 and 15, the power of the laser beam condensed on the recording surface of the optical disk 108 is reduced by the amount of the laser beam incident on the monitoring light detection element 109 via the DBS 103. There is a problem that the recordable speed becomes slow. This problem is greatly related to the performance, quality, reliability and design of the optical pickup device.

  In the optical pickup device shown in FIG. 16, the laser beams 114 and 115 outside the effective area are guided to the monitoring light detection elements 116 and 117, so that the power of the laser beam condensed on the recording surface of the optical disk is not reduced.

  However, although the optical pickup device of FIG. 16 is not affected by the variation in the reflection / transmittance characteristics of the DBS 103, the number of parts for the light detection elements 116 and 117 for monitoring increases. Since the work for disposing the elements 116 and 117 increases, there is a problem that the manufacturing cost increases.

  Further, since the positions of the monitoring light detection elements 116 and 117 are close to the laser beams 110 and 111 in the effective region, even if the positions of the monitoring light detection elements 116 and 117 are slightly shifted, the laser beams 110 and 111 in the effective region are detected. There is a risk of losing. That is, the laser beams 110 and 111 in the effective area may be reduced. Such a situation greatly relates to the performance, quality and reliability of the optical pickup device.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an optical pickup device that can reduce the control gain adjustment range of the APC circuit, increase the recordable speed, and reduce the manufacturing cost.

In order to achieve the above object, an optical pickup device of the present invention comprises:
In an optical pickup device that performs at least one of reproduction, erasure, and recording of information on an information recording medium,
A first light source that emits a laser beam toward the information recording medium;
A second light source that emits a laser beam having a wavelength different from the wavelength of the laser beam of the first light source toward the information recording medium, and has an optical axis that is non-parallel to the optical axis of the laser beam of the first light source;
The laser beams emitted from the first and second light sources are arranged to pass through, and the optical axis of the laser beam of the first light source and the optical axis of the laser beam of the second light source are substantially matched on the output side. An optical element;
A photodetection element for monitoring that receives a part of the laser beam emitted from the first and second light sources;
A reflection mirror facing the light receiving surface of the light detection element for monitoring via the optical element;
The light receiving surface of the monitor light detection element is substantially parallel to the optical axis of the laser beam of the first and second light sources,
The laser beams emitted from the first and second light sources in the direction of the optical element have an elliptical shape with a wide emission angle in the vertical direction compared to the horizontal direction.
A part of the laser beam is reflected by the reflection mirror and guided to the light receiving surface of the monitoring light detection element.

  According to the optical pickup device having the above configuration, the laser beams emitted from the first and second light sources pass through the optical element and are then irradiated onto the information recording medium. At this time, since the light receiving surface of the monitoring light detection element is substantially parallel to the optical axes of the laser beams of the first and second light sources, the laser beam outside the effective area of the first and second light sources is used for monitoring. Incident on the light receiving surface of the photodetecting element. Thus, since the monitoring light detection element receives the laser beam outside the effective area of the first and second light sources, the amount of light received by the monitoring light detection element does not vary greatly from device to device. Therefore, when the outputs of the first and second light sources are controlled by an APC circuit, for example, the adjustment range of the control gain of the APC circuit can be reduced.

  Further, since the monitoring light detecting element receives the laser beam outside the effective area of the first and second light sources, the light quantity of the laser beam irradiated to the information recording medium is not reduced, and the recordable speed for the information recording medium is achieved. Can be faster.

  In addition, since the laser beam outside the effective area of the first and second light sources is incident on the light receiving surface of the monitoring light detecting element, the monitoring light detecting element for APC controlling the outputs of the first and second light sources. Only one is enough. Therefore, the number of parts is reduced, and the manufacturing cost can be kept low.

  In this specification, the information recording medium refers to an optical disk, a magneto-optical disk, a phase change optical disk, or the like.

  In the optical pickup device of one embodiment, the reflection mirror is formed by using a part of a housing that houses the first and second light sources, the optical element, and the monitoring light detection element.

  According to the optical pickup device of the above embodiment, since the reflection mirror is formed by using a part of the housing, it is possible to prevent the number of parts from increasing.

  According to the optical pickup device of the present invention, since the light receiving surface of the monitoring light detection element is substantially parallel to the optical axes of the laser beams of the first and second light sources, the laser outside the effective area of the first and second light sources. The beam is incident on the light receiving surface of the monitoring light detection element. Accordingly, the amount of light received by the monitoring light detection element does not vary greatly from device to device, and when the output of the first and second light sources is controlled by an APC circuit, for example, the adjustment range of the control gain of the APC circuit can be reduced. it can.

  Further, since the monitoring light detecting element receives the laser beam outside the effective area of the first and second light sources, the light quantity of the laser beam irradiated to the information recording medium is not reduced, and the recordable speed for the information recording medium is achieved. Can be faster.

  In addition, since the laser beam outside the effective area of the first and second light sources is incident on the light receiving surface of the monitoring light detecting element, the monitoring light detecting element for APC controlling the outputs of the first and second light sources. The number is only one, and the manufacturing cost can be kept low.

  In addition, since a reflection mirror for increasing the laser beam incident on the monitor light detection element is disposed in the vicinity of the optical element, the laser beam incident on the monitor light detection element increases, and the monitor light is increased. The laser beam incident on the detection element can be stably monitored.

  Before describing embodiments of the present invention, reference examples will be described in order to make the present invention easier to understand.

(Reference Example 1)
FIG. 1 shows a schematic view of the configuration of the optical pickup device of Reference Example 1 of the present invention as viewed from the side, and FIG. 2 shows a schematic diagram of the configuration of the optical pickup device as seen from above.

  As shown in FIGS. 1 and 2, the optical pickup device includes a first light receiving and emitting integrated element 1 as an example of a first light source that emits a laser beam 10 toward an optical disc 8 as an example of an information recording medium. The laser beam 11 is arranged so as to pass through the second light receiving and emitting integrated element 2 as an example of a second light source that emits a laser beam 11 having a wavelength different from that of the laser beam 10 toward the optical disc 8. A cube-shaped DBS 3 as an example of an optical element, and a monitoring light detection element 9 disposed near and above the DBS 3 are provided. In the optical path between the DBS 3 and the optical disk 8, a collimating lens 4, a rising mirror 5, a quarter wavelength plate 6, and an objective lens 7 are arranged.

  The optical axis 12 of the laser beam 10 of the first light receiving and emitting integrated element 1 is not parallel to the optical axis 13 of the laser beam 11 of the second receiving and emitting integrated element 2. The optical axis 12 and the optical axis 13 are substantially perpendicular to each other at DBS3. The DBS 3 substantially matches the optical axis 12 and the optical axis 13 on the output side.

  The light receiving surface 9 a of the monitoring light detecting element 9 is substantially parallel to the optical axes 12 and 13. The monitoring light detection element 9 is arranged so that the laser beam 14 outside the effective region emitted from the first light receiving and emitting integrated element 1 is incident on the light receiving surface 9a, and the second light receiving and emitting integrated type. It arrange | positions so that the laser beam outside the effective area | region which the element | device 2 emits may inject into the light-receiving surface 9a.

  Although not shown, a light emitting element and a light receiving element for receiving the reflected beam reflected by the optical disk 8 are installed inside the first and second light receiving and emitting integrated elements 1 and 2, respectively. In the first and second integrated light receiving and emitting elements 1 and 2, the light emitting element and the light receiving element are integrated.

  In the optical pickup device having the above configuration, the laser beam 10 in the effective area emitted from the first light receiving and emitting integrated element 1 passes through the DBS 3 and then becomes a parallel beam by the collimator lens 4 and is perpendicularly formed by the rising mirror 5. The light is bent, transmitted through the quarter-wave plate 6, and condensed on the recording surface of the optical disk 8 by the objective lens 7. Then, the reflected beam reflected by the optical disk 8 returns to the first light receiving and emitting integrated element 1 along the same path as the forward path. As a result, the reflected beam reflected by the optical disc 8 is received by the light receiving element in the first light receiving and emitting integrated element 1. Information recorded on the optical disc 8 is detected based on the electrical signal output from the light receiving element.

  The effective region laser beam 11 emitted from the second light emitting / receiving integrated element 2 is reflected by the DBS 3 and then sequentially passes through the collimating lens 4, the rising mirror 5, and the quarter wavelength plate 6. The light is condensed on the recording surface of the optical disk 8 by the lens 7. Then, the reflected beam reflected by the optical disk 8 returns to the second light receiving and emitting integrated element 2 along the same path as the forward path. Thereby, the reflected beam reflected by the optical disk 8 is received by the light receiving element in the second light receiving and emitting integrated element 2. Information recorded on the optical disc 8 is detected based on the electrical signal output from the light receiving element.

  Incidentally, the laser beams emitted from the first and second integrated light receiving and emitting elements 1 and 2 have an elliptical intensity distribution with a wide radiation angle in the vertical direction compared to the horizontal direction. On the other hand, since the laser beams 10 and 11 in the effective area focused on the recording surface of the optical disc 8 are circular, it can be said that the laser beam 14 outside the effective area is wide in the vertical direction.

  The laser beam 14 emitted from the first light receiving and emitting integrated element 1 outside the effective region is incident on the light receiving surface 9 a of the monitoring light detecting element 9. The monitoring light detecting element 9 outputs an electrical signal corresponding to the light amount of the received laser beam 14 outside the effective area. This electric signal is supplied to an APC circuit (not shown) to drive the APC circuit. As a result, the output of the first light receiving and emitting integrated element 1 is controlled, and the laser beam condensed on the recording surface of the optical disc 8 has an appropriate power.

  The laser beam outside the effective region emitted from the second light receiving / emitting integrated element 2 is incident on the light receiving surface 9 a of the monitoring light detecting element 9. The monitoring light detection element 9 outputs an electrical signal corresponding to the amount of the received laser beam outside the effective area. This electric signal is supplied to the APC circuit, and the APC circuit is driven. As a result, the output of the second light receiving and emitting integrated element 2 is controlled, and the laser beam condensed on the recording surface of the optical disc 8 has an appropriate power.

  As described above, since the light receiving surface 9a of the monitoring light detecting element 9 is substantially parallel to the optical axes 12 and 13, the laser outside the effective region of the first and second light receiving and emitting integrated elements 1 and 2 is obtained. The beam 14 is incident on the light receiving surface 9 a of the monitoring light detection element 9. Therefore, the amount of light received by the monitoring light detection element 9 does not change greatly from device to device, and the control gain adjustment range of the APC circuit can be reduced.

  Further, since the monitoring light detecting element 9 receives the laser beam 14 outside the effective area of the first and second integrated light receiving and emitting elements 1 and 2, the light quantity of the laser beam irradiated on the optical disk 8 does not decrease. The recordable speed of the optical disc 8 can be increased.

  Further, since the laser beam 14 outside the effective area of the first and second light receiving and emitting integrated elements 1 and 2 is received by one monitor light detecting element 9, the first and second light receiving and emitting integrated elements 1, The number of parts required for controlling the output of 2 is reduced, and the manufacturing cost can be kept low.

  Further, since the monitoring light detection element 9 is disposed near and above the DBS 3 so that the light receiving surface 9a is substantially parallel to the optical axes 12 and 13, the position of the monitoring light detection element 9 is slightly shifted. However, the monitoring light detection element 9 does not irradiate the laser beams 10 and 11 in the effective region. Therefore, it is possible to prevent the performance, quality, and reliability of the optical pickup device from deteriorating.

  Further, since the light emitting elements of the first and second light receiving and emitting elements 1 and 2 are integrated with the light receiving element that receives the reflected beam reflected by the optical disc 8, the number of parts can be further reduced.

  In the reference example 1, the monitoring light detection element 9 is disposed near and above the DBS 3, but may be disposed near and below the DBS 3. Also in this case, the light receiving surface 9 a of the monitoring light detecting element 9 is substantially parallel to the optical axis 12 and the optical axis 13.

  The optical pickup device may be any device that performs at least one of reproduction, erasure, and recording of information on the optical disc 8.

  Needless to say, the type of the optical disk 8 that irradiates the laser beam 10 of the first light receiving and emitting integrated element 1 and the type of the optical disk 8 that irradiates the laser beam 11 of the second receiving and emitting integrated element 2 are different from each other. Yes. For example, the laser beam 10 of the first light receiving / emitting integrated element 1 may be irradiated to the CD, and the laser beam 11 of the second light receiving / emitting integrated element 2 may be irradiated to the DVD.

  In place of the optical disk 8, a phase change optical disk or a magneto-optical disk may be used.

  Examples of the first and second light receiving and emitting integrated elements 1 and 2 include a hologram laser element and a laser coupler. Examples of the light emitting elements in the first and second light receiving and emitting integrated elements 1 and 2 include a semiconductor laser element.

(Reference Example 2)
FIG. 3 shows a view of the configuration of the optical pickup device of Reference Example 2 of the present invention as viewed from above. In FIG. 3, the same components as those shown in FIGS. 1 and 2 are denoted by the same reference numerals as those in FIGS. 1 and 2, and description thereof is omitted.

  The optical pickup device of FIGS. 1 and 2 includes the first and second light receiving and emitting integrated elements 1 and 2, but the optical pickup device of the present reference example 2 is an optical disc (not shown) as shown in FIG. As an example of a first light emitting element 21 that emits a laser beam 23 toward the optical disk and a second light source that emits a laser beam 24 having a wavelength different from that of the laser beam 23 toward the optical disk. A second light emitting element 22. The first and second light emitting elements 21 and 22 are separated from the light receiving elements 31 and 32 that receive the reflected beam reflected by the optical disk. Beam splitters 27 and 28 and cylindrical lenses 29 and 30 are arranged in the optical path between the light receiving elements 31 and 32 and the DBS 3.

  The optical axis 25 of the laser beam 23 of the first light emitting element 21 and the optical axis 26 of the laser beam 24 of the second light emitting element 22 are not parallel. The optical axis 25 and the optical axis 26 are substantially perpendicular to each other in DBS3. The DBS 3 substantially matches the optical axis 25 and the optical axis 26 on the output side.

  The light receiving surface 9a (see FIG. 1) of the monitoring light detecting element 9 is substantially parallel to the optical axes 25 and 26. The monitoring light detection element 9 is arranged such that a laser beam outside the effective region emitted from the first and second light emitting elements 21 and 22 is incident on the light receiving surface 9a.

  According to the optical pickup device having the above configuration, the laser beam 23 in the effective region emitted from the first light emitting element 21 passes through the DBS 3, becomes a parallel beam by the collimator lens 4, and is bent at a right angle by the rising mirror 5. Then, the light passes through the quarter-wave plate 6 and is focused on the recording surface of the optical disk by the objective lens 7. The reflected beam reflected by the optical disk follows the same path as the forward path, passes through the DBS 3, is reflected by the beam splitter 27, and enters the light receiving element 31 through the cylindrical lens 29. Information recorded on the optical disc is detected based on the electrical signal output from the light receiving element 31.

  The effective region laser beam 24 emitted from the second light emitting element 22 is reflected by the DBS 3 and then sequentially passes through the collimating lens 4, the rising mirror 5, and the quarter wavelength plate 6, and then by the objective lens 7. It is condensed on the recording surface of the optical disk. The reflected beam reflected by the optical disk follows the same path as the forward path, is reflected by the DBS 3, is further reflected by the beam splitter 28, and enters the light receiving element 32 through the cylindrical lens 30. Information recorded on the optical disk is detected based on the electrical signal output by the light receiving element 32.

  Further, since the light receiving surface 9a of the monitoring light detecting element 9 is substantially parallel to the optical axes 25 and 26, the laser beam outside the effective area of the first and second light emitting elements 21 and 22 is monitored light. Since the light is incident on the light receiving surface 9a of the detection element 9, the amount of light received by the monitoring light detection element 9 does not vary greatly from device to device, and the adjustment range of the control gain of the APC circuit can be reduced.

  Further, since the monitoring light detecting element 9 receives the laser beam outside the effective area of the first and second light emitting elements 21 and 22, the amount of the laser beam applied to the optical disk is not reduced, and recording on the optical disk is possible. Speed can be increased.

  Also, since the laser beam outside the effective area of the first and second light emitting elements 21 and 22 is received by one monitoring light detecting element 9, the outputs of the first and second light emitting elements 21 and 22 are APC controlled. Therefore, the number of parts necessary for the reduction can be reduced, and the manufacturing cost can be kept low.

  Further, since the monitoring light detecting element 9 is disposed near and above the DBS 3 so that the light receiving surface 9a is substantially parallel to the optical axes 25 and 26, the position of the monitoring light detecting element 9 is slightly shifted. However, the monitoring light detection element 9 does not reach the laser beams 23 and 24 in the effective region. Therefore, it is possible to prevent the performance, quality, and reliability of the optical pickup device from deteriorating.

  Further, since the first and second light emitting elements 21 and 22 and the light receiving elements 31 and 32 that receive the reflected beam from the optical disk are separated, the degree of freedom in designing the optical system can be increased.

  In the optical pickup device, many components are arranged around the first and second light emitting elements 21 and 22. In such a case, it is difficult to dispose the monitoring light detection element in the conventional examples of FIGS. 14 to 16, but in this reference example 2, the monitoring light detection element 9 is disposed near and above the DBS 3. The arrangement of the monitor light detection element 9 is easy.

  In the reference example 2, the monitoring light detection element 9 is disposed near and above the DBS 3, but may be disposed near and below the DBS 3. Also in this case, the light receiving surface 9 a of the monitoring light detecting element 9 is made substantially parallel to the optical axis 25 and the optical axis 26.

  In the reference example 2, the beam splitters 27 and 28 are used. However, a polarizing beam splitter may be used instead of the beam splitters 27 and 28.

  Examples of the first and second light emitting elements 21 and 22 include semiconductor laser elements.

  Further, instead of the first light emitting element 21, as shown in FIG. 4, the first light receiving and emitting integrated element 1 shown in FIGS. 1 and 2 may be used. In this case, the beam splitter 27, the cylindrical lens 29, and the light receiving element 31 shown in FIG. 3 are not necessary, and the number of components can be reduced as compared with the optical pickup device shown in FIG.

  Also in the case of FIG. 4, the monitoring light detection element 9 may be disposed near and below the DBS 3 so that the light receiving surface 9 a is substantially parallel to the optical axis 12 and the optical axis 26.

  Although not shown, the second light receiving and emitting integrated element 2 shown in FIGS. 1 and 2 may be used instead of the second light emitting element 22. Also in this case, the number of parts can be reduced as compared with the optical pickup device of FIG.

  Needless to say, when the second light receiving and emitting integrated element 2 is used instead of the second light emitting element 22, the monitoring light detecting element 9 may be disposed near and below the DBS 3.

(Reference Example 3)
FIG. 5 is a schematic view of the configuration of the optical pickup device of Reference Example 3 according to the present invention as viewed from above. In FIG. 5, the same components as those shown in FIGS. 1 and 2 are denoted by the same reference numerals as those in FIGS. 1 and 2, and description thereof is omitted.

  The optical pickup device includes a non-cubic DBS 33 as an example of an optical element disposed so that the laser beams 10 and 11 of the first and second light receiving and emitting integrated elements 1 and 2 pass through. A monitoring light detection element 9 is disposed near and above the DBS 33, and a light receiving surface 9 a (see FIG. 1) of the monitoring light detection element 9 is placed on the optical axes 12 and 13 of the laser beams 10 and 11. It is almost parallel to it. The optical axis 12 of the laser beam 10 and the optical axis 13 of the laser beam 11 are non-parallel and non-orthogonal. The DBS 33 substantially matches the optical axis 12 and the optical axis 13 on the output side.

  Although not shown, the optical pickup device includes a collimating lens 4, a rising mirror 5, a quarter wavelength plate 6, and an objective lens 7, as in the optical pickup devices of FIGS. 1 and 2.

  According to the optical pickup device having the above configuration, the monitoring light detection element 9 is disposed in the vicinity of and above the DBS 33 so that the light receiving surface 9a is substantially parallel to the optical axes 12 and 13. The laser beam outside the effective area of the second light receiving and emitting integrated elements 1 and 2 can be efficiently received by the monitoring light detecting element 9.

  Like the optical pickup device of Reference Example 3, the optical pickup device of the present invention may include a DBS having a complicated shape instead of a cube. That is, the optical pickup device of the present invention may include a polyhedral DBS in which the surface that receives the laser beam 10 and the surface that receives the laser beam 11 are inclined non-orthogonally. This DBS can substantially match two non-orthogonal optical axes on the output side.

  Needless to say, the optical pickup device according to the third embodiment exhibits the same effect as the first embodiment.

  In the reference example 3, the monitoring light detection element 9 is disposed near and above the DBS 33, but may be disposed near and below the DBS 33. Also in this case, the light receiving surface 9 a of the monitoring light detecting element 9 is substantially parallel to the optical axis 12 and the optical axis 13.

(Reference Example 4)
FIG. 6 shows a schematic view of the configuration of the optical pickup device of Reference Example 4 of the present invention as viewed from above. In FIG. 6, the same components as those shown in FIGS. 1 and 2 are denoted by the same reference numerals as those in FIGS. 1 and 2, and description thereof is omitted.

  The optical pickup device includes a third light receiving and emitting integrated element 41 as an example of a third light source. The third light receiving / emitting integrated element 41 emits a laser beam 42 having a wavelength different from that of the laser beams 10 and 11 of the first and second light receiving / emitting integrated elements 1 and 2 toward an optical disc (not shown). The optical pickup device has a rectangular parallelepiped shape as an example of an optical element disposed so that the laser beams 10, 11, and 42 of the first, second, and third light receiving and emitting integrated elements 1, 2, and 41 pass through. DBS43 is provided.

  The optical axis 12 of the laser beam 10 is not parallel to the optical axes 13 and 44 of the second and third integrated light receiving and emitting elements 2 and 41 of the laser beams 11 and 42. The optical axis 13 is substantially parallel to the optical axis 44. The optical axis 12 is substantially orthogonal to the optical axes 13 and 44 by the DBS 43. The DBS 43 substantially matches the optical axis 12, the optical axis 13, and the optical axis 44 on the output side.

  The light receiving surface 9a (see FIG. 1) of the monitoring light detecting element 9 is substantially parallel to the optical axis 12, the optical axis 13, and the optical axis 44. The monitoring light detection element 9 is arranged so that a laser beam outside the effective region emitted from the first light receiving and emitting integrated element 1 is incident on the light receiving surface 9a, and the second light receiving and emitting integrated element A laser beam outside the effective region from which the light 2 is emitted is arranged to enter the light receiving surface 9a. Specifically, the monitoring light detection element 9 is disposed above the location where the optical axis 12 and the optical axis 13 intersect and in the vicinity of the DBS 43.

  Although not shown, a light emitting element and a light receiving element for receiving a reflected beam reflected by the optical disk are installed inside the third light receiving and emitting integrated element 41. The light emitting element and the light receiving element are integrated.

  According to the optical pickup device having the above configuration, the wavelength of the laser beam 42 emitted from the third light receiving / emitting integrated element 41 is the same as that of the laser beams 10 and 11 emitted from the first and second light receiving / emitting integrated elements 1 and 2. Since the wavelength is different, at least one of information reproduction, erasure and recording can be performed by the third light receiving / emitting integrated element 41 with respect to the optical disc which the first and second light receiving / emitting integrated elements 1 and 2 cannot process. it can.

  Needless to say, the optical pickup device according to the fourth embodiment has the same effect as the first embodiment.

  A quarter wavelength plate 6 is disposed between the rising mirror 5 and the objective lens 7.

  In the reference example 4, the monitoring light detection element 9 is disposed near and above the DBS 43, but may be disposed near and below the DBS 43. Also in this case, the light receiving surface 9 a of the monitoring light detecting element 9 is substantially parallel to the optical axis 12 and the optical axis 13.

(Reference Example 5)
FIG. 7 is a schematic view of the configuration of the optical pickup device of Reference Example 5 according to the present invention viewed from the side. In FIG. 7, the same components as those shown in FIGS. 1 and 2 are denoted by the same reference numerals as those in FIGS. 1 and 2, and description thereof is omitted.

  The optical pickup device includes a DBS 53 as an example of an optical element. The DBS 53 has a shape in which the upper part is cut to such an extent that it does not reach the laser beam 10 in the effective region emitted from the first light receiving and emitting integrated element 1. That is, the DBS 53 is thinned to such an extent that the upper surface 53a is not applied to the laser beam 10 in the effective region of the first light receiving and emitting integrated element 1. The upper surface (surface on the monitoring light detection element 9 side) 53a of the DBS 53 is inclined with respect to a plane including the optical axes 12 and 13 (see FIG. 2) of the laser beams 10 and 11.

  In Reference Example 5 described above, the DBS 53 is thinned to such an extent that the upper surface 53a is not covered with the laser beam 10 in the effective region of the first light receiving and emitting integrated device 1, but the laser in the effective region of the second light receiving and emitting integrated device 2 is used. The DBS 53 may be thinned to such an extent that the upper surface 53a does not cover the beam 11 (see FIG. 2). Alternatively, the DBS 53 is thinned to such an extent that the upper surface 53a is not covered with the laser beam 10 in the effective area of the first light receiving and emitting integrated element 1 and the laser beam 11 in the effective area of the second receiving and emitting integrated element. Also good.

  Further, the monitoring light detection element 9 may be arranged near and below the DBS 53. In this case, the lower surface of the DBS 53 may be inclined with respect to the plane including the optical axes 12 and 13 of the laser beams 10 and 11.

(Reference Example 6)
FIG. 8 is a schematic view of the configuration of the optical pickup device of Reference Example 6 according to the present invention viewed from the side. In FIG. 8, the same components as those shown in FIGS. 1 and 2 are denoted by the same reference numerals as those in FIGS. 1 and 2, and description thereof is omitted.

  The optical pickup device includes a composite element 63 having functions of a DBS and a monitoring light detection element as an example of an optical element. The composite element 63 has a light detection part 63a as a monitor light detection element in the upper part, and the laser beam 14 outside the effective region emitted from the first light receiving and emitting integrated element 1 enters the light detection part 63a. To do. Thereby, the laser beam 14 is detected as a monitor signal, and the output of the first light receiving and emitting integrated element 1 can be APC controlled.

  Since the optical pickup device having the above configuration includes the composite element 63 having the functions of the DBS and the monitoring light detection element, the number of components can be reduced.

  In addition, since the composite element 63 is used, there is a possibility that the laser beam in the effective area may be scattered by the monitoring light detection element due to a so-called sticking shift of the monitoring light detection element or a positional shift of the monitoring light detection element. Disappear. In other words, there is no possibility that the monitoring light detection element is applied to the laser beam in the effective region.

  Further, since the composite element 63 is used, the influence of the temperature change is reduced in the light reception of the light detection unit 63a.

  In the reference example 6, the light detection unit 63a is provided above the composite element 63, but the light detection unit 63a may be provided below the composite element 63.

  Instead of the composite element 63, as shown in FIG. 9, a composite element 64 having functions of a DBS and a monitoring light detection element may be used. The composite element 64 has a light detection unit 64a as a monitor light detection element on which the laser beam 14 outside the effective region is incident. A reflection mirror 64b is provided on a part of the end face of the composite element 64 on the collimator lens 4 side. The reflection mirror 64b reflects the laser beam 15 outside the effective region emitted from the first light receiving and emitting integrated element 1 and guides it to the light detection unit 64a. Thereby, the light quantity of the laser beam which injects into the light detection part 64a from the said 1st light emitting / receiving integrated element 1 increases, and the output of the 1st light receiving / emitting integrated element 1 can be stably APC-controlled. At this time, the light quantity of the laser beam which is not reflected by the reflection mirror 64b and is directly incident on the light detection unit 64a is not reduced.

  Instead of the composite element 63, as shown in FIG. 10, a composite element 65 having functions of a DBS and a monitoring light detection element may be used. This composite element 65 has a light detection unit 65a as a monitor light detection element on which the laser beam 14 outside the effective region is incident. Further, a reflection mirror 65 b is provided deep inside the composite element 65. That is, the reflection mirror 65b is embedded in the composite element 65 and is not exposed. The reflection mirror 65b reflects and guides the laser beam 15 emitted from the first light receiving and emitting integrated element 1 outside the effective region to the light detection unit 64a. Thereby, the light quantity of the laser beam which injects into the light detection part 65a from the said 1st light emitting / receiving integrated element 1 increases, and the output of the 1st light receiving / emitting integrated element 1 can be stably APC-controlled. At this time, the light quantity of the laser beam which is not reflected by the reflection mirror 65b and is directly incident on the light detection unit 64a is not reduced.

  Further, if an adhesive for fixing the composite element 65 is applied in the vicinity of the reflection mirror 65b, the reflection surface of the reflection mirror 65b may be corroded by the adhesive. However, since the reflection mirror 65b is provided deep inside the composite element 65, the reflection surface of the reflection mirror 65b is not exposed, and corrosion or deterioration due to a fixing adhesive or the like occurs on the reflection surface of the reflection mirror 65b. Does not occur.

  Although the reflection mirrors 64b and 65b in FIGS. 9 and 10 are concave mirrors, they may be plane mirrors. That is, the shape of the reflection mirrors 64b and 65 may be any shape as long as it reflects the laser beam 15 outside the effective region emitted from the first light receiving and emitting integrated element 1 and can guide it to the light detection unit 64a.

  Further, as shown in FIG. 11, the reflection surfaces 64c and 65c of the reflection mirrors 64b and 65b may be curved so as to guide laser beams from two different directions to the light detection units 64a and 65a. Specifically, the reflection surfaces 64c and 65c of the reflection mirrors 64b and 65b reflect the laser beam outside the effective region emitted from the first and second light receiving and emitting integrated elements 1 and 2 to detect the light detection unit 64a. , 65a may be curved. In this case, since the light amount of the laser beam outside the effective region incident on the light detectors 64a and 65a from the first and second light receiving and emitting integrated elements 1 and 2 increases, the first and second light receiving and emitting integrated elements APC control can be performed stably for the outputs of 1 and 2.

  By using a reflecting mirror having a shape as shown in FIG. 11, it is possible to deal with laser beams emitted from a plurality of light sources, and to stably perform APC control of all the outputs of the plurality of light sources.

  Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

  FIG. 12 is a schematic view of the configuration of the optical pickup device according to the embodiment of the present invention as viewed from the side. In FIG. 12, the same components as those shown in FIGS. 1 and 2 are denoted by the same reference numerals as those in FIGS. 1 and 2, and description thereof is omitted.

  In the optical pickup device, the reflection mirror 74 is disposed near and below the DBS 3. The reflection mirror 74 reflects the laser beam 16 outside the effective region emitted from the first light receiving and emitting integrated element 1 and guides it to the light receiving surface 9 a of the monitoring light detecting element 9.

  In the optical pickup device having the above configuration, the laser beam 14 outside the effective region directed upward is reflected by the reflection mirror 74 and is incident on the light receiving surface 9a of the monitoring light detection element 9. At the same time, the laser beam 16 outside the effective area going downward is reflected by the reflection mirror 74 and enters the light receiving surface 9 a of the monitoring light detection element 9. Therefore, the light quantity of the laser beam incident on the light receiving surface 9a of the monitoring light detecting element 9 is increased, and the output of the first light receiving and emitting integrated element 1 can be stably APC controlled.

  Instead of disposing the reflection mirror 74, a reflection mirror 75 may be provided on a part of the housing 70 as shown in FIG. The reflection mirror 75 has a function similar to that of the reflection mirror 74 of FIG. 12 and reflects the laser beam 16 outside the effective area emitted from the first light receiving and emitting integrated element 1 to reflect the monitoring light detection element 9. Guide to the light receiving surface 9a. The housing 70 accommodates the DBS 3 and the collimating lens 4, and in some cases, the housing 70 may also accommodate the first and second light receiving / emitting integrated elements 1 and 2 and the monitoring light detection element 9.

  Although the reflecting mirrors 74 and 75 in FIGS. 12 and 13 are concave mirrors, they may be plane mirrors. That is, the shape of the reflection mirrors 74 and 75 may be such that the laser beam 16 emitted from the first light receiving and emitting integrated element 1 is reflected outside the effective region and guided to the light receiving surface 9 a of the monitoring light detecting element 9. Anything is fine.

  Further, the reflection surfaces of the reflection mirrors 74 and 75 may be curved so that laser beams from two different directions are guided to the monitoring light detection element 9.

FIG. 1 is a schematic view of a configuration of an optical pickup device according to a first embodiment of the present invention viewed from the side. FIG. 2 is a schematic view of the configuration of the optical pickup device of Reference Example 1 as viewed from above. FIG. 3 is a schematic view of the configuration of the optical pickup device of Reference Example 2 of the present invention as viewed from above. FIG. 4 is a schematic view of the configuration of the modified example of the reference example 2 as viewed from above. FIG. 5 is a schematic view of the configuration of the optical pickup device of Reference Example 3 of the present invention as viewed from above. FIG. 6 is a schematic view of the configuration of the optical pickup device of Reference Example 4 of the present invention as viewed from above. FIG. 7 is a schematic view of the configuration of the optical pickup device of Reference Example 5 according to the present invention viewed from the side. FIG. 8 is a schematic view of the configuration of the optical pickup device of Reference Example 6 according to the present invention viewed from the side. FIG. 9 is a schematic view of the configuration of the modified example of the reference example 6 seen from the side. FIG. 10 is a schematic view of the configuration of the modified example of the reference example 6 seen from the side. FIG. 11 is a schematic view of the configuration of the modified example of the reference example 6 as viewed from above. FIG. 12 is a schematic view of the configuration of the optical pickup device according to the embodiment of the present invention viewed from the side. FIG. 13 is a schematic view of the configuration of the modified example of the above embodiment as viewed from the side. FIG. 14 is a schematic view of the configuration of a conventional optical pickup device viewed from the side. FIG. 15 is a schematic view of the configuration of the optical pickup device as viewed from above. FIG. 16 is a schematic view of another conventional optical pickup device viewed from above.

Explanation of symbols

1, 2, 41 Light receiving / emitting integrated element 3, 33, 43, 53 DBS
8 Optical disk 9 Photodetecting element 9a for monitoring Light receiving surface 10, 11, 23, 24, 42 Laser beam 12, 13, 25, 26, 44 in effective region Optical axis 14, 15, 16 Laser beam 21, 22 outside effective region Light emitting element 63, 64, 65 Composite element 63a, 64a, 65a Photodetector

Claims (2)

In an optical pickup device that performs at least one of reproduction, erasure, and recording of information on an information recording medium,
A first light source that emits a laser beam toward the information recording medium;
A second light source that emits a laser beam having a wavelength different from the wavelength of the laser beam of the first light source toward the information recording medium, and has an optical axis that is non-parallel to the optical axis of the laser beam of the first light source;
The laser beams emitted from the first and second light sources are arranged to pass through, and the optical axis of the laser beam of the first light source and the optical axis of the laser beam of the second light source are substantially matched on the output side. An optical element;
A photodetection element for monitoring that receives a part of the laser beam emitted from the first and second light sources;
A reflection mirror facing the light receiving surface of the light detection element for monitoring via the optical element;
The light receiving surface of the monitor light detection element is substantially parallel to the optical axis of the laser beam of the first and second light sources,
The laser beams emitted from the first and second light sources in the direction of the optical element have an elliptical shape with a wide emission angle in the vertical direction compared to the horizontal direction.
A part of the laser beam is reflected by the reflection mirror and guided to the light receiving surface of the monitoring light detection element. The optical pickup device according to claim 1,
The optical pickup device, wherein the reflection mirror is formed by using a part of a housing that houses the first and second light sources, the optical element, and the monitoring light detection element.

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