JP4743188B2 - Light receiving element, method of attaching the same, optical pickup, and optical disk reproducing apparatus including the same - Google Patents

Description

  The present invention relates to a light receiving element and a method for attaching the light receiving element, and more particularly to a light receiving element attached to an optical pickup and a method for finely adjusting the position thereof. The present invention also relates to an optical pickup to which such a light receiving element is attached, and an optical disk reproducing apparatus having the same.

  An optical pickup used in an optical disk reproducing apparatus is composed of a number of optical components such as a laser diode and a light receiving element. Since extremely high positional accuracy is required for mounting these optical components, the mounting position is finely adjusted by actually irradiating a test optical disk with a laser beam and detecting reflected light.

  FIG. 5 is a schematic diagram for explaining the function of the optical pickup.

  As shown in FIG. 5, the optical pickup 10 includes a laser diode 11 and a light receiving element (photodiode IC) 12. The output beam B from the laser diode 11 is separated into a main beam MB and two sub beams SB1 and SB2 by the diffraction grating 13, and is irradiated onto the optical disc 20 through the half mirror 14 and the objective lens 15. These beams are reflected by the optical disk 20 and input to the light receiving element 12 via the objective lens 15 and the half mirror 14. The objective lens 15 is driven by the actuator 16 in a minute range in the tracking direction and the focusing direction.

  Here, the main beam MB is a beam used for reproducing (or recording) data, and is irradiated along the groove G as shown in FIG. On the other hand, the sub beams SB1 and SB2 are beams used for tracking servo and focus servo, and are irradiated along lands L1 and L2 adjacent to the groove G as shown in FIG. 6, for example (see Patent Document 1).

  FIG. 7 is a plan view schematically showing the configuration of the light receiving element 12.

  As shown in FIG. 7, the light receiving element 12 includes a main beam light receiving unit 30 for receiving the main beam MB reflected by the optical disc 20, and a sub beam receiving unit for receiving the sub beams SB1 and SB2 reflected by the optical disc 20, respectively. 31 and 32. The main beam receiving unit 30 and the sub beam receiving units 31 and 32 are arranged in the Y direction shown in FIG. 7, and their positions in the X direction are substantially coincident (may be shifted in the X direction).

  Each of the main beam light receiving unit 30 and the sub beam light receiving units 31 and 32 includes four light receiving regions. Specifically, the main beam light receiving unit 30 is configured by light receiving regions A, B, C, and D, the sub beam light receiving unit 31 is configured by light receiving regions E1, E2, E3, and E4, and the sub beam light receiving unit 32 is configured by the light receiving region F1. , F2, F3, and F4.

  Here, in the focus-on state, the main beam MB reflected by the optical disk 20 is irradiated substantially evenly onto the light receiving areas A, B, C, and D constituting the main beam light receiving unit 30. Similarly, the sub-beam SB1 is substantially evenly irradiated to the light-receiving areas E1, E2, E3, and E4 constituting the sub-beam light receiving section 31, and the sub-beam SB2 is received by the light-receiving areas F1, F2, and F3 constituting the sub-beam light receiving section 32. , F4 is irradiated substantially uniformly.

  On the other hand, when the distance between the objective lens 15 and the optical disc 20 is too short, or conversely, when the distance between the objective lens 15 and the optical disc 20 is too long, the main beam MB and the sub beam irradiated on the light receiving element 12 are. The beam shapes of SB1 and SB2 are deformed into an ellipse. As a result, the amount of beam irradiated to each light receiving region becomes non-uniform.

  More specifically, when the distance between the objective lens 15 and the optical disc 20 is too short, the beam shapes of the main beam MB and the sub beams SB1 and SB2 are deformed as shown in FIG. For this reason, in the main beam light receiving unit 30, the sum of the outputs of the light receiving areas A and C (= VA + VC) is larger than the sum of the outputs of the light receiving areas B and D (= VB + VD). Similarly, for the sub-beam light receiving units 31 and 32, the sum of the outputs of the light receiving regions E1, E3, F1, and F3 (= VE1 + VE3 + VF1 + VF3) is larger than the sum of the outputs of the light receiving regions E2, E4, F2, and F4 (= VE2 + VE4 + VF2 + VF3). Become.

  Conversely, when the distance between the objective lens 15 and the optical disk 20 is too long, the beam shapes of the main beam MB and the sub beams SB1 and SB2 are deformed as shown in FIG. For this reason, in the main beam light receiving unit 30, the sum of the outputs of the light receiving areas A and C (= VA + VC) is smaller than the sum of the outputs of the light receiving areas B and D (= VB + VD). Similarly, for the sub-beam light receiving units 31, 32, the sum of the outputs of the light receiving areas E1, E3, F1, F3 (= VE1 + VE3 + VF1 + VF3) is smaller than the sum of the outputs of the light receiving areas E2, E4, F2, F4 (= VE2 + VE4 + VF2 + VF3). Become.

  Therefore, the distance between the optical pickup 10 and the optical disc 20 can be detected by monitoring (VA + VC) − (VB + VD), for example, and focus on can be performed based on this.

JP 2004-39109 A

  However, in order to correctly irradiate the main beam MB and the sub beams SB1 and SB2 to the centers of the light receiving units 30 to 32 in the focus-on state, the light receiving element 12 is attached to the optical pickup 10 at a correct angle. Need to be. Conventionally, the rotation angle θ of the light receiving element 12 is adjusted by measuring the amplitude of (VE1 + VE3 + VF1 + VF3) − (VE2 + VE4 + VF2 + VF4) and detecting the position where the amplitude is maximum. However, since the value of (VE1 + VE3 + VF1 + VF3) − (VE2 + VE4 + VF2 + VF4) is always 0 and the amplitude is not observed in the focus on state, the conventional rotation angle adjustment has to be performed in the focus off state.

  On the other hand, the position adjustment of the light receiving element 12 in the XY directions is performed in a focus-on state. Therefore, conventionally, the adjustment of the rotation angle θ of the light receiving element 12 must be performed in a focus off state, and the position adjustment of the light receiving element 12 in the X and Y directions must be performed in a focus on state, and this on / off must be repeated. There was a problem that had to be done.

  Further, since the position in the XY direction is also shifted in the focus off state, the adjustment of the rotation angle θ and the fine adjustment of the XY position have to be repeated. For this reason, it is not easy to match both the position of the light receiving element 12 in the XY direction and the rotation angle θ, and there is a problem that adjustment takes time.

  The present invention has been made to solve such problems, and an object thereof is to provide a light receiving element that can be easily attached to an optical pickup and a method that can easily adjust the position thereof.

  It is another object of the present invention to provide an optical pickup to which such a light receiving element is attached and an optical disk reproducing apparatus having the same.

  A light receiving element according to the present invention includes a main beam light receiving unit for receiving a main beam reflected by an optical disc, and first and second sub beam receiving units for receiving first and second sub beams reflected by the optical disc, respectively. And a main detection signal output terminal for outputting a detection signal from the main beam light receiving unit, a sub detection signal output terminal for outputting a detection signal from the first and second sub beam light receiving units, and a case of operating in the first mode. Has a mode signal input terminal that is in the first state and is in the second state when operating in the second mode, and the mode signal input terminal is in the first or second state The sub detection signal output terminal outputs a combined detection signal of the first and second sub beam light receiving units, and the mode signal input terminal is different from the first and second states. In the third state, the detection signal of the first sub-beam light receiving unit is output from the sub detection signal output terminal without combining the detection signals of the first and second sub-beam light receiving units. It is characterized by.

  An optical pickup according to the present invention is characterized in that the above-described light receiving element is attached. Furthermore, an optical disk reproducing apparatus according to the present invention includes the above optical pickup.

  According to the present invention, by setting the mode signal input terminal to the third state, it is possible to output only the detection signal of the first sub beam light receiving unit from the sub detection signal output terminal. Unlike the combined detection signal of the second sub-beam light receiving unit, the value in the focus-on state does not always become zero. As a result, the rotation angle θ of the light receiving element can be adjusted in the focus-on state, so that the mounting position of the light receiving element can be determined easily and accurately.

  In addition, the mode signal input terminal is a terminal that exists to change the operation mode of the light receiving element, and is not a dedicated terminal for adjusting the rotation angle θ of the light receiving element, so the number of terminals may increase. Absent.

  In the present invention, the main beam receiving unit includes a main beam receiving unit for the first type optical disc and a main beam receiving unit for the second type optical disc, and the first sub beam receiving unit is the first type optical disc. A first sub-beam light receiving unit for the second type of optical disk and a second sub-beam light receiving unit for the second type of optical disk. When the mode signal input terminal is in the first state, the main detection signal output terminal is connected to the main beam receiving unit for the first type optical disc. The detection signal is output, and the combined detection signal of the first and second sub beam light receiving portions for the first type optical disk is output from the sub detection signal output terminal, and the mode signal input terminal is set to the second state. In this case, the main detection signal output terminal outputs the detection signal of the main beam light receiving unit for the second type optical disc, and the sub detection signal output terminal outputs the first and second types for the second type optical disc. The detection signal of the sub beam light receiving unit can be output.

  Although not particularly limited, the first type of optical disk can be a DVD (or BD (Blu-ray Disc (registered trademark)), and the second type of optical disk can be a CD. According to this, in a compatible player of DVD and CD, it is possible to enter the test mode using the mode signal input terminal that exists for switching between DVD and CD.

  In the present invention, the first state is a state in which a relatively high level signal is input, the second state is a state in which a relatively low level signal is input, and the third state is a high level. An impedance state is preferred. According to this, the three states can be reliably determined, and the test mode is not erroneously entered in the actual use state.

  A light receiving element mounting method according to the present invention is a light receiving element mounting method for mounting the above-described light receiving element to an optical pickup, and the main beam is received by detecting a signal output from a main detection signal output terminal. Output from the sub detection signal output terminal in the first step of adjusting the mounting position of the light receiving element so as to irradiate a predetermined position of the light source, and in a state where the main beam is irradiated to the predetermined position of the main beam light receiving part And a second step of adjusting the mounting position of the light receiving element so that the first sub beam is irradiated to a predetermined position of the first sub beam light receiving unit by detecting the signal to be transmitted. In this step, the mode signal input terminal is set to the third state.

  According to the present invention, after adjusting the relative positional relationship between the main beam and the main beam light receiving unit, the relative positional relationship between the sub beam and the sub beam receiving unit is adjusted while maintaining this. For this reason, it is possible to easily and accurately determine the mounting position of the light receiving element. Therefore, both the first and second steps can be performed with the optical pickup focused on the optical disc.

  The first step in the present invention is preferably performed by translating the light receiving element in the vertical direction with respect to the optical path of the main beam. According to this, it becomes possible to fix the position in the XY direction of the light receiving element by the first step.

  In this case, the main beam light receiving unit includes a plurality of light receiving regions, and the first step is preferably adjusted so that the plurality of light receiving regions included in the main beam light receiving unit are uniformly irradiated with the main beam. . For example, when the main beam light receiving unit is configured by four light receiving areas A, B, C, and D as shown in FIG. Adjustment may be made so that the beam is irradiated substantially evenly.

  The second step in the present invention is preferably performed by rotating the light receiving element around the optical path of the main beam. Accordingly, the rotation angle θ of the light receiving element can be determined by the second step.

  In this case, the sub-beam light receiving unit includes a plurality of light receiving regions that are substantially equal in distance to the main beam light receiving unit, and the second step is that the sub beams are evenly distributed to the plurality of light receiving regions included in the sub beam light receiving unit. It is preferable to adjust so that it may be irradiated. For example, when the sub-beam light receiving part is constituted by four light receiving areas E1, E2, E3, E4 as shown in FIG. 7, the light receiving areas E1, E2 having substantially the same distance from the main beam light receiving part. Alternatively, the light receiving areas E3 and E4 may be adjusted so that the main beam is substantially evenly irradiated.

  Thus, according to the present invention, it is possible to easily adjust the position of the light receiving element in the XY direction and the rotation angle θ without providing a dedicated terminal for adjusting the rotational angle θ of the light receiving element. It becomes. As a result, it is possible to reduce the manufacturing cost of the optical pickup and the optical disk reproducing apparatus including the optical pickup while preventing an increase in the cost of the light receiving element itself.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present embodiment, the configuration of the optical pickup 10 to which the light receiving element is attached is as shown in FIG.

  FIG. 1 is a schematic diagram showing an appearance of a light receiving element (PDIC) 100 according to a preferred embodiment of the present invention.

  The light receiving element 100 according to the present embodiment is incorporated in an optical pickup used in the optical recording / reproducing apparatus. In the present embodiment, the optical recording / reproducing apparatus is used particularly for a CD / DVD / BD compatible player, and includes 20 light receiving areas (A, B, C, D, E1, E2, E3, E4, F1). , F2, F3, F4, a, b, c, d, e1, e2, f1, f2). Each light receiving region is arranged in any one of the light receiving portions R-1 to R-6. Hereinafter, BD and DVD are referred to as a first type optical disk, and CD is referred to as a second type optical disk.

  The light receiving parts R-1 to R-3 are used for recording / reproducing of the first type optical disc. The main beam receiving unit R-1 includes four light receiving areas A, B, C, and D, and receives the main beam MB reflected by the first type optical disc. The sub-beam light receiving unit R-2 includes four light receiving regions E1, E2, E3, and E4, and receives the sub beam SB1 reflected by the first type optical disk. The sub-beam receiving unit R-3 includes four light-receiving regions F1, F2, F3, and F4, and receives the sub-beam SB2 reflected from the first type optical disk.

  The light receiving parts R-4 to 6 are used for recording / reproducing of the second type optical disk. The main beam receiving unit R-4 includes four light receiving areas a, b, c, and d, and receives the main beam MB reflected by the second type optical disk. The sub-beam light receiving unit R-5 is composed of two light-receiving regions e1 and e2, and receives the sub-beam SB1 reflected by the second type optical disk. The sub-beam light receiving unit R-6 includes two light receiving regions f1 and f2, and receives the sub beam SB2 reflected by the second type optical disk.

  As shown in FIG. 1, the light receiving element 100 according to the present embodiment has 16 external terminals. Specifically, the terminals 101 to 103 are power supply terminals to which the power supply potential Vcc, the ground potential GND, and the reference potential Vs are supplied, respectively. Terminals 104 and 105 are data output terminals for outputting complementary data signals VRFP and VRFN, respectively. The terminals 106 to 109 are respectively detected signals (VA, VB, VC, VD) by the light receiving areas A, B, C, D or detected signals (Va, Vb, Vc, Vd) by the light receiving areas a, b, c, d. Is a main detection signal output terminal.

  The terminal 110 is a sub detection signal output terminal from which a combined detection signal (VEF1) of the light receiving areas E1 and F1 or a detection signal (Ve1) of the light receiving area e1 is output. The terminal 111 is a sub detection signal output terminal from which a combined detection signal (VEF2) of the light receiving areas E2 and F2 or a detection signal (Vf1) of the light receiving area f1 is output. The terminal 112 is a sub detection signal output terminal from which a combined detection signal (VEF3) of the light receiving areas E3 and F3 or a detection signal (Ve2) of the light receiving area e2 is output. The terminal 113 is a sub detection signal output terminal from which a combined detection signal (VEF4) of the light receiving areas E4 and F4 or a detection signal (Vf2) of the light receiving area f2 is output.

  Terminals 114 and 115 are gain switching terminals to which control signals (G1 and G2) for gain switching are input, and the terminal 116 determines whether the first type optical disk or the second type optical disk is used. A mode signal input terminal to which a mode signal (Mode) to be selected is input.

  The mode signal Mode input to the mode signal input terminal 116 can take three states. The first state is a high level state. In this case, the first type optical disk (DVD or BD) is used. Therefore, detection signals VA, VB, VC, and VD based on the light receiving areas A, B, C, and D are output from the main detection signal output terminals 106 to 109, respectively, and from the sub detection signal output terminals 110 to 113, respectively. Composite detection signals VEF1, VEF2, VEF3, and VEF4 are output.

  On the other hand, the second state is a low level state. In this case, the second type optical disc (CD) is used. Therefore, detection signals Va, Vb, Vc, and Vd based on the light receiving areas a, b, c, and d are output from the main detection signal output terminals 106 to 109, respectively, and from the sub detection signal output terminals 110 to 113, respectively. Detection signals Ve1, Vf1, Ve2, and Vf2 are output.

  These detection signals (and combined detection signals) are used as servo signals for detecting defocusing of the light spot and deviation from the track in a controller described later.

  Further, the third state is a high impedance state. In this case, the light receiving element 100 enters the test mode. When the test mode is entered, the detection signals VE1, VE2, and VE2 of the sub-beam light receiving unit R-2 are not synthesized from the sub-detection signal output terminals 110 to 113 without combining the detection signals of the sub-beam light receiving units R-2 and R-3. Only VE3 and VE4 are output.

  The test mode is a mode that is not used in the actual use state, and is a mode that is used when the light receiving element 100 is attached to the optical pickup. As described above, in this embodiment, the mode signal input terminal 116 used in the actual use state can be entered into the test mode by being in the high impedance state. Therefore, it is not necessary to provide a dedicated terminal (test terminal) for entry into the test mode, and an increase in the number of external terminals necessary for the light receiving element 100 can be prevented.

  FIG. 2 is a flowchart for explaining the light receiving element mounting method according to the present embodiment. The light receiving element mounting method according to the present embodiment will be described below along the flowchart shown in FIG.

  First, the mode signal Mode is set to the high level, and the mode for using the first type optical disc (DVD or BD) is entered (step S10). Next, the optical pickup 10 shown in FIG. 5 is focused on the optical disc 20 (step S11). In this operation, the distance between the objective lens 15 and the optical disk 20 is periodically changed (vibrated) using the actuator 16, and the main beam receiving unit R-1 is connected via the main detection signal output terminals 106 to 109. This can be done by monitoring the output (VA + VC)-(VB + VD) and holding the objective lens 15 at a point where it becomes almost zero.

  Next, in the focus-on state, the output of the main beam light receiving unit R-1 is monitored via the main detection signal output terminals 106 to 109 (step S12). Based on this, the light receiving element 100 is connected to the main beam MB. Translate in a direction perpendicular to the optical path. Thereby, the position in the XY direction of the light receiving element 100 is adjusted (step S13).

  The position of the light receiving element 100 in the X direction can be detected by (VA + VD) − (VB + VC), and the position of the light receiving element 100 in the Y direction can be detected by (VA + VB) − (VC + VD). Therefore, the position in the X direction may be adjusted so that (VA + VD) − (VB + VC) becomes zero, and the position in the Y direction may be adjusted so that (VA + VB) − (VC + VD) becomes zero.

  If these are substantially zero, as shown in FIG. 3, the light receiving areas A, B, C, and D included in the main beam light receiving unit R-1 are evenly irradiated with the main beam MB. Become. The position adjustment of the light receiving element 100 in the XY directions can be automatically performed using an adjustment jig and a driving device.

  However, at this stage, the sub-beams SB1 and SB2 are not correctly applied to the sub-beam light receiving portions R-2 and R-3, and the angle in the θ direction is shifted.

  Next, the mode signal input terminal 116 is set to the high impedance state (step S14), and the state where the main beam MB is evenly applied to the light receiving areas A, B, C, D is maintained. The output is monitored (step S15). As described above, when the mode signal input terminal 116 is set to the high impedance state, the light receiving element 100 enters the test mode. As a result, the detection signals VE1, VE2, VE3, and VE4 of the sub beam light receiving unit R-2 are not synthesized from the sub detection signal output terminals 110 to 113 without the detection signals of the sub beam light receiving units R-2 and R-3 being combined. Is output only. Based on this, the light receiving element 100 is rotated in the θ direction about the optical path of the main beam MB. Thereby, the angle in the θ direction of the light receiving element 100 is adjusted (step S16).

  The angle adjustment in the θ direction is such that the output difference between the light receiving regions that are substantially equal in distance to the main beam light receiving unit R-1 among the light receiving regions E1 to E4 constituting the sub beam light receiving unit R-2 is substantially zero. The light receiving element 100 is rotated so that Specifically, the output of the sub beam light receiving unit R-2 is monitored via the sub detection signal output terminals 110 to 113, and the rotation angle in the θ direction of the light receiving element 100 is set so that (VE1 + VE4) − (VE2 + VE3) becomes zero. Is preferably adjusted.

  And if these become substantially zero, as shown in FIG. 7, it will be in the state by which sub-beam SB1 was uniformly irradiated to light-receiving area | regions E1-E4 included in sub-beam light-receiving part R-2. Further, since the two sub beams SB1 and SB2 appear symmetrically with the main beam MB as the center, the sub beam light receiving portion R-3 should be in a state where the sub beam SB2 is evenly irradiated to the light receiving regions F1 to F4. . The angle adjustment of the light receiving element 100 in the θ direction can also be automatically performed.

  As described above, each of the beams MB, SB1, and SB2 is correctly irradiated on the corresponding light receiving units R-1 to R-3. Further, if the light beam for the first type optical disc (DVD or BD) is correctly irradiated on the light receiving portions R-1 to R-3, the beam for the second type optical disc (CD) is inevitably generated. The light receiving units R-4 to R-6 are correctly irradiated.

  As described above, in the light receiving element mounting method according to the present embodiment, in the focused state, the position of the light receiving element 100 in the XY direction is first adjusted, and then the angle of the light receiving element 100 in the θ direction is adjusted. Therefore, it is possible to easily determine the mounting position of the light receiving element. As a result, it is possible to reduce the manufacturing cost of the optical pickup and the optical disk reproducing apparatus including the same.

  Here, in the angle adjustment in the θ direction, the combined signal from the sub-beam light receiving units R-2 and R-3 is not used, but the mode signal input terminal 116 is set in a high impedance state, thereby the sub-beam light receiving unit R-2. The reason why only the output of is used is as follows.

  That is, when the combined signals VEF1 to VEF4 from the sub beam light receiving units R-2 and R-3 are used, even if the angle of the light receiving element 100 is shifted in the θ direction, as shown in FIG. -2 changes in the outputs VE1 to VE4 and the changes in the outputs VF1 to VF4 of the sub-beam light receiving unit R-3 are out of phase with each other. Specifically, since VE1 + VE4≈VF2 + VF3 and VE2 + VE3≈VF1 + VF4, the combined signal (VEF1 + VEF4) − (VEF2 + VEF3) is always almost zero regardless of θ.

  From this point of view, in this embodiment, the angle adjustment in the θ direction is performed using only the signals VE1 to VE4 from the sub-beam light receiving unit R-2 instead of using the combined signals VEF1 to VEF4.

  FIG. 4 is a block diagram schematically showing the configuration of the optical disc reproducing apparatus 200 including the optical pickup 10 to which the light receiving element 100 according to the present embodiment is attached.

  An optical disk reproducing device 200 shown in FIG. 4 includes a spindle motor 202 for rotating the optical disk 20, an optical pickup 10 that irradiates the optical disk 20 with a laser beam and receives reflected light, and the spindle motor 202 and the optical pickup 10. A controller 204 that controls the operation, a laser drive circuit 205 that supplies a laser drive signal to the optical pickup 10, and a lens drive circuit 206 that supplies a lens drive signal to the optical pickup 10 are provided.

  The controller 204 includes a focus servo tracking circuit 207, a tracking servo tracking circuit 208, and a laser control circuit 209. When the focus servo tracking circuit 207 is activated, the recording surface of the rotating optical disk 20 is focused, and when the tracking servo tracking circuit 208 is activated, the eccentric signal track of the optical disk 20 is detected. The laser beam spot is in an automatic tracking state.

  The focus servo tracking circuit 207 and the tracking servo tracking circuit 208 are each provided with an auto gain control function for automatically adjusting the focus gain and an auto gain control function for automatically adjusting the tracking gain. The laser control circuit 209 is a circuit that generates a laser drive signal supplied from the laser drive circuit 205, and generates an appropriate laser drive signal in order to keep the reproduction output constant.

  The focus servo tracking circuit 207, the tracking servo tracking circuit 208, and the laser control circuit 209 do not need to be circuits built in the controller 204, and may be separate components from the controller 204. Furthermore, these need not be physical circuits, and may be software executed in the controller 204. The optical disc playback apparatus 200 may have a recording function, or may be a playback-only apparatus that does not have a recording function.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. Needless to say, it is included in the range.

  For example, in the above embodiment, the test signal is entered by setting the mode signal input terminal 116 to the high impedance state, but the method of entering the test mode is not limited to this. As another method of entering the test mode, for example, there is a method of setting the mode signal input terminal 116 to an intermediate level.

  In the above embodiment, the rotation angle in the θ direction of the light receiving element 100 is adjusted so that (VE1 + VE4) − (VE2 + VE3) becomes zero in step S16. However, the light receiving region that constitutes the sub beam light receiving unit R-2. Of E1 to E4, the adjustment is not limited to this as long as the output difference between the light receiving regions having substantially the same distance from the main beam light receiving unit R-1 is adjusted to be substantially zero. Therefore, it may be adjusted so that VE1-VE2 becomes zero, or may be adjusted so that VE3-VE4 becomes zero.

  Furthermore, in the above embodiment, the light receiving element used in the CD / DVD / BD compatible player has been described as an example, but the present invention is not limited to this. Therefore, for example, a light receiving element used for a DVD player may be used.

It is a schematic diagram which shows the external appearance of the light receiving element (PDIC) 100 by preferable embodiment of this invention. 4 is a flowchart for explaining a light receiving element mounting method according to a preferred embodiment of the present invention. It is a schematic plan view showing the positional relationship between each beam MB, SB1, SB2 and the light receiving units R-1 to R-3 in the state where step S13 is completed. 2 is a block diagram schematically showing the configuration of an optical disc playback apparatus 200. FIG. It is a schematic diagram for demonstrating the function of an optical pick-up. 4 is a schematic plan view showing the irradiation position of each beam MB, SB1, SB2 on the optical disc 20. FIG. 2 is a plan view schematically showing a configuration of a light receiving element 12. FIG. It is a figure for demonstrating the beam shape on the light receiving element 12 in case the distance of the optical pick-up 10 and the optical disk 20 is too short. It is a figure for demonstrating the beam shape on the light receiving element 12 in case the distance of the optical pick-up 10 and the optical disk 20 is too long.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Optical pick-up 11 Laser diode 12 Light receiving element 13 Diffraction grating 14 Half mirror 15 Objective lens 16 Actuator 20 Optical disk 30 Main beam light receiving part 31, 32 Sub beam light receiving part 100 Light receiving element 101-103 Power supply terminals 104, 105 Data output terminals 106-109 Main detection signal output terminals 110 to 113 Sub detection signal output terminals 114 and 115 Gain switching terminal 116 Mode signal input terminal 200 Optical disc reproducing apparatus 202 Spindle motor 204 Controller 205 Laser drive circuit 206 Lens drive circuit 207 Focus servo tracking circuit 208 Tracking servo tracking Circuit 209 Laser control circuit R-1, R-4 Main beam receiver R-2, R-3, R-5, R-6 Sub beam receiver MB SB1, SB2 sub beam

Claims (9)

A first main beam light receiving portion for the first main beam receiving light is the light beam reflected by the first type of optical disk, the light reflected by the different second type of optical disc and the second one of the optical disk A second main beam light receiving unit for receiving a second main beam which is a beam, a light beam reflected by the first type optical disc , and a first and a first beam corresponding to the first main beam. First and second sub-beam light receiving portions for receiving the second sub-beam, respectively , and light beams reflected by the second type optical disc, respectively , and third and second light beams corresponding to the second main beam. Detection signals from the third and fourth sub-beam light receiving sections for receiving the four sub-beams and the first and second main beam receiving sections, respectively. First to fourth main detection signal output terminals, first to fourth sub detection signal output terminals for outputting detection signals from the first to fourth sub beam light receiving sections, and a first mode. A mode signal input terminal that is in a first state in a case, and in a second state different from the first state when operating in a second mode,
The first main beam receiving unit and the first and second sub beam receiving units are respectively a center line of the light receiving unit in a first direction and the light receiving unit in a second direction perpendicular to the first direction. Are divided into first to fourth light receiving regions by the center line of
When the mode signal input terminal is in the first state, the first to fourth light receptions of the first main beam light receiving unit are respectively received from the first to fourth main detection signal output terminals. The detection signal of the first sub-beam light receiving unit and the detection signal of the first sub-beam light receiving unit and the second sub-beam light receiving unit are output from the first to fourth sub detection signal output terminals, respectively. A combined detection signal with a detection signal of the first light receiving region, a detection signal of the second light receiving region of the first sub-beam light receiving unit, and a detection signal of the second light receiving region of the second sub-beam light receiving unit , A combined detection signal of a detection signal of the third light receiving region of the first sub-beam light receiving unit and a detection signal of the third light receiving region of the second sub-beam light receiving unit, and the first 1 subby And it outputs a combined detection signal of the detection signal of the fourth light receiving area of the detection signal of the fourth light receiving area of the light receiving portion and the second sub-beam light-receiving unit,
When the mode signal input terminal is in the second state, the first to fourth main detection signal output terminals output detection signals of the second main beam light receiving unit and the first To output detection signals of the third and fourth sub beam light receiving units from the fourth sub detection signal output terminal,
When the mode signal input terminal is in a third state different from the first and second states, the first and second sub beams are output from the first to fourth sub detection signal output terminals. Without combining the detection signals of the light receiving portions, the detection signals of the first light receiving regions of the first sub-beam light receiving portions, the detection signals of the second light receiving regions of the first sub-beam light receiving portions, respectively. detection signal of the third light receiving area of the first sub-beam light-receiving unit, a detection signal of said fourth light receiving region of the first sub-beam light-receiving unit outputs,
The first main beam light receiving unit is a quadrilateral light receiving unit having first and second sides parallel to the first direction and third and fourth sides parallel to the second direction. Yes,
The first sub-beam light receiving unit is disposed at a position facing the third side of the first main beam light receiving unit in the first direction,
The second sub-beam light receiving unit is on the opposite side of the first main beam light-receiving unit across the first main beam light-receiving unit, and the fourth side of the first main beam light-receiving unit and the first side A light receiving element disposed at a position facing the first direction . Before Stories second main beam light receiving portion is divided into the first the and the direction of the center line of the light receiving portion of the second direction of the first to fourth by the center line of the light receiving portion of the light-receiving region And
The third and fourth sub-beam light receiving portions are divided into first and second light receiving regions by a center line of the light receiving portion in the first direction,
When the mode signal input terminal is in the second state, the first to fourth light receptions of the second main beam light receiving unit are respectively received from the first to fourth main detection signal output terminals. The detection signal of the area is output, and the detection signal of the first light receiving area of the third sub-beam light receiving unit and the detection signal of the fourth sub-beam light receiving unit are respectively output from the first to fourth sub detection signal output terminals. Outputting a detection signal of the first light receiving region, a detection signal of the second light receiving region of the third sub-beam light receiving unit, and a detection signal of the second light receiving region of the fourth sub-beam light receiving unit. The light receiving element according to claim 1.   The first state is a state in which a relatively high level signal is input, the second state is a state in which a relatively low level signal is input, and the third state is a high impedance state. The light receiving element according to claim 1, wherein the light receiving element is in a state. A light receiving element attaching method for attaching the light receiving element according to any one of claims 1 to 3 to an optical pickup,
By detecting signals output from the first to fourth main detection signal output terminals, the light reception is performed so that the first main beam is irradiated to a predetermined position of the first main beam light receiving unit. A first step of adjusting the mounting position of the element;
By detecting signals output from the first to fourth sub-detection signal output terminals in a state where the first main beam is irradiated on the predetermined position of the first main beam light receiving unit, A second step of adjusting an attachment position of the light receiving element so that the first sub beam is irradiated to a predetermined position of the first sub beam light receiving unit;
At least in the second step, the mode signal input terminal is set to the third state.   5. The light receiving element mounting method according to claim 4, wherein both the first and second steps are performed in a state where the optical pickup is focused on the optical disk.   6. The light receiving element mounting method according to claim 4, wherein the first step is performed by translating the light receiving element in a vertical direction with respect to an optical path of the first main beam.   The light receiving element mounting method according to any one of claims 4 to 6, wherein the second step is performed by rotating the light receiving element about an optical path of the first main beam.   An optical pickup comprising the light receiving element according to any one of claims 1 to 3.   An optical disk reproducing device comprising the optical pickup according to claim 8.

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