JP3162835B2 - Optical pickup device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup device used for an optical head of an optical disk device or the like.

[0002]

2. Description of the Related Art Generally, in an optical disk apparatus, in order to record / reproduce an information signal with a small light beam from an optical head while holding the optical disk and driving the optical disk at a predetermined number of revolutions, the optical head must be driven by the optical head. It is necessary to irradiate the emitted optical beam to the optical disk perpendicularly. This is because if the light beam is not irradiated perpendicularly to the optical disk, the light beam becomes elliptical light on the optical disk surface, cross-talk occurs by detecting information of an adjacent track, thereby causing performance degradation, and Further, when the tilt angle is further increased, defocus occurs, and a problem such that a predetermined performance cannot be maintained occurs. However, in practice, it is generally difficult to irradiate the optical disk vertically with a small light beam from the optical head within a predetermined accuracy due to the combination of the tolerances of each part, even if the optical disk device is assembled with high accuracy. Is required.

Conventionally, with respect to the tilt adjustment of an optical head,
For example, an optical head is provided with a light source and a detector, a small light beam is irradiated on the information recording medium, and a tilt angle caused by warpage, deflection, etc. of the information recording medium is detected using the detector, and the optical head is used for information recording. By tilting the optical head in the tracking direction and the jitter direction in accordance with the detection result by the tilting means which is independent of the tracking direction and the jitter direction of the medium, the minute head from the optical head is always in the entire recording area of the information recording medium. There has been proposed an optical head tilt mechanism of an optical disk apparatus in which a light beam is irradiated perpendicularly to an information recording medium (Japanese Patent Laid-Open No. 61-28-1986).
No. 4840).

FIG. 5 is a perspective view of an optical head optical system having a tilt mechanism according to the prior art, and FIG. 6 is a block diagram showing an optical disk apparatus provided with the optical head tilt mechanism of FIG. 5 and 6, reference numeral 1 denotes an optical disk device, 2 denotes an optical disk, and 10 denotes a disk drive for holding the optical disk and driving the optical disk at a predetermined number of rotations, and includes a disk motor 11, a turntable 12, a clamper 13, and the like. ing. 20 is an optical head, 20a is a protruding portion from the optical head 20, 21 is a light beam, 22 is a pin, 23 is an arm, 24
Is a pulley, 25 is a guide shaft, 26 is a guide plate, 26a is a rotation fulcrum, 27 is an optical head driving mechanism, 30 is a light emitting element 50 and two-part light receiving elements 51, 52 or four-part light receiving element 55, etc. A deflection detector, 31 is a tracking direction detection signal, 32 is a tracking direction detection circuit, 33 is a tracking direction control signal, 34 is a jitter direction detection signal, 35 is a jitter direction detection circuit, 36 is a jitter direction control signal, and 40 is a tracking direction detection signal. A tilt mechanism, 41 is an eccentric pulley, 45 is a jitter direction tilt mechanism, and 46 is an eccentric pulley.

In the optical disk device 1 having the above configuration,
The optical disk 2 is set on the turntable 12 of the disk drive unit 10, and the disk motor is held by the clamper 13.
According to 11, the optical disk 2 is driven at a predetermined rotation speed. Therefore, as shown in FIG. 5, a pin 22 fixed to the optical head 20 is provided on the arm 23 (provided on both sides on the same center line).
The optical head 20 is held via the optical head 20 and records and reproduces an information signal by performing a well-known focus and tracking control on a track of the optical disc 2 by a minute light beam 21 emitted from the optical head 20. is there. Also,
As shown in FIG. 5, one end of the arm 23 is engaged with the guide shaft 25, and the other end is held by a guide plate 26 via a pulley 24 provided on the arm 23. Optical head drive mechanism shown in FIG. 6 with a movable configuration
Light beam 21 on any track of optical disk 2 by 27
Can be accessed.

An optical head tilt mechanism is provided in the optical disk device 1. That is, the light beam of the optical head 20
A deflection detector 30 is provided in the vicinity of the irradiation of the beam 21, whereby the tilt angle between the optical disk 2 and the optical head 20 is always detected in the tracking direction and the jitter direction. Then, a tracking direction detection signal 31 which is a detection result of the tracking direction is input to a tracking direction detection circuit 32 as shown in FIG. 6, and the tracking direction control mechanism 33 is used to drive the tracking direction tilt mechanism 40. And thereby the pin fixed to the optical head 20
22 is set in the tracking direction of the optical disc 2 with the pivot point 22. Also, the jitter direction detection signal 34, which is the result of detecting the other jitter direction, is input to the jitter direction detection circuit 35, and the jitter direction control mechanism 36, which is the output thereof, is used to drive the jitter direction tilt mechanism 45. Guide plate
26, Operate the pulley 24 to move the arm 23 to the guide shaft
It is tilted in the jitter direction of the optical disc 2 with 25 as a pivot point. Thus, the optical head 20 engaged with the arm 23 is also tilted in the jitter direction. That is, the tilt angle between the optical head 20 and the optical disk 2 is always detected, and the optical head 20 can be raised independently in the tracking direction and the jitter direction of the optical disk 2 using the detection result. To optical disk 2
Can be irradiated vertically.

Next, FIG. 7A shows the configuration of a conventional deflection detector 30, and FIG. 7B shows a circuit diagram of a signal detection circuit.
In FIG. 7A, the deflection detector 30 includes a light emitting element 50 on a substrate 57.
And light receiving elements 51 and 52 which are arranged above and below the light emitting element 50 (in the tracking direction) and are divided into two in the tracking direction. In the detection method, the light beam emitted from the light emitting element 50 is reflected by the optical disk 2, the reflected light is incident on light receiving elements 51 and 52 provided above and below the light emitting element 50, and the light receiving element 51 corresponding to the amount of the incident light is detected. , 52, the amount of deflection (tilt angle) between the optical disk 2 and the optical head 20 is detected. That is, in the circuit diagram of FIG. 7B, the deflection amount in the tracking direction is 2
Each of the two divided light receiving element portions 51a and 51 of the divided light receiving elements 51 and 52
The tracking direction control signal 33 is obtained by comparing the sum signal 31 pair (tracking direction detection signal) of 1b, 52a and 52b by the tracking direction detection circuit 32 and taking the difference.
What you get as The deflection amount in the jitter direction is equal to the light receiving element portions 51a and 51a on one side of the two divided light receiving elements 51 and 52.
The sum signal pair (jitter direction detection signal) of 2a, 51b and 52b is compared by the jitter direction detection circuit 35, and the difference is obtained to obtain a jitter direction control signal 36.

[0008]

As described above, the conventional optical head having a tilting mechanism always applies a small light beam from the optical head to the optical disk even if the optical disk is deformed due to warpage or bending of the optical disk. It can be controlled to irradiate vertically. However, it is necessary to provide a light emitting element different from the light emitting element of the recording / reproducing signal in the optical head, so that the design of the optical pickup device is costly. Further, in the optical disk device, means for detecting the position of the optical head is required to read information at an arbitrary position on the information recording medium. As one of the means, there is a method of irradiating light to an encoder and detecting the position of an optical head according to a change in the amount of reflected light. However, there has hitherto not been any one in which the deflection detection and the position detection of the moving optical system are performed with the same light source.

The present invention has been made in view of the above, and has as its object to (1) reduce the number of components of a tilt detection system of a moving optical system, reduce costs, and (2) use the same light source. Accordingly, it is an object of the present invention to provide an optical pickup device capable of simultaneously performing a tilt adjustment and a position detection of a moving optical system and (3) forming a super-resolution spot.

[0010]

To achieve the above object, according to an aspect of, the invention of claim 1, the fixed optical system collimating lens is arranged to collimate light from a light source, parallel light beam from the fixed optical system a deflecting prism (62) for deflecting the light emitted by and the objective lens (60) is arranged to irradiate the light deflected by the deflecting prism (62) on the condenser to the information recording medium (2) in the separation type optical pickup device consisting of movable optical system (69) that is a mirror that reflects light in the central portion of the flat Yukimitsu bundle into a parallel light beam before Symbol movable optical system (69) (6
1) was installed, and the light beam at the center was removed by the mirror (61).
The parallel light beam is transmitted to the information recording medium (2) by the objective lens (60).
And used to form a minute spot,
Means for separating the central beam reflected by (61) in two directions
(65), means (67) for guiding one of the separated light beams onto the information recording medium, and light reflected by the information recording medium (2) of the light beam guided by the means (67) is received. 4
A split light receiving element (70) and a means for guiding the other light beam separated by the separating means (65) to an encoder (68) provided on a side surface or a lower portion around the moving optical system.
(64, 66) and a light receiving element (63) for receiving light reflected by the encoder (68) of the light beam guided by the means (64, 66), and the light reflected by the information recording medium (2) is provided . Receive
The information recording based on the signal from the four-division light receiving element (70)
Deflection detection of jitter direction and tracking direction of medium (2)
And receive the reflected light from the encoder (68).
The position of the moving optical system (69) based on the signal from the optical element (63)
Detection is performed (FIG. 1).

[0011] deflector prism in the invention of claim 2, in which a fixed optical system collimating lens is arranged to collimate the light from the light source to deflect the light beam emitted by a parallel beam from the fixed optical system (62) and a movable optical system (69) provided with an objective lens (60) for condensing the light deflected by the deflecting prism (62) and irradiating the information recording medium (2). in the optical pickup device, before Symbol movable optical system
The objective lens from the deflection prism (62 ) in (69)
In the optical path to (60), the light at the center of the parallel beam is reflected in two directions.
A prism (73) for splitting by projection is provided, and the prism (73) is
The parallel light beam from which the light beam at the center is removed is the objective lens
The light is focused on the information recording medium (2) by the
Means (7) for guiding the one light beam used for formation and divided by the prism (73) onto the information recording medium.
And 4,71), 4 split for receiving the light reflected by the means (the information recording medium of the light beam guided by 74,71) (2)
Means (72, 75) for guiding a light receiving element (70) and another light beam split by the prism (73) to an encoder (68) provided on a side surface or a lower portion around the moving optical system.
And a light receiving element (63) for receiving light reflected by the encoder (68) of the light beam guided by the means (72, 75) ,
4-split receiver for receiving light reflected by the information recording medium (2)
The information recording medium (2) based on a signal from the optical element (70);
Detection of jitter in the jitter direction and tracking direction.
A light receiving element for receiving the reflected light from the encoder (68)
The position of the moving optical system (69) is detected based on the signal from (63).
And performing (Figure 2).

[0012] deflector prism in the invention of claim 3, in which a fixed optical system collimating lens is arranged to collimate the light from the light source to deflect the light beam emitted by a parallel beam from the fixed optical system (62) and a movable optical system (69) provided with an objective lens (60) for condensing the light deflected by the deflecting prism (62) and irradiating the information recording medium (2). in the optical pickup device, before Symbol movable optical system
In the center of the reflection surface of the deflecting prism (62) in (69)
Transmits the central beam of the parallel beam from the fixed optical system
A transmission part (82) having a band shape is provided, and the transmission part (82) provides a central part.
Parallel light beam reflected by the reflecting surface after removing the light beam
Is focused on the information recording medium (2) by the objective lens (60).
And the deflection prism is used for forming minute spots.
(62) transmits a part of the light transmitted through the transmission part (82) to an encoder (6
8), a prism (80) in which a deflecting prism that reflects light toward the information recording medium (2) and a deflecting prism that reflects the remaining light toward the information recording medium (2) is provided, and the information recording is performed by the prism (80). Means (85) for guiding the light beam reflected on the medium side onto the information recording medium, and a four-division light receiving element ( 4 ) for receiving the light beam guided by the means (85) reflected by the information recording medium (2) 70) and the luminous flux reflected on the encoder side by the prism (80).
Means (84) for guiding the light beam guided by the means (84), and a light receiving element for receiving the reflected light of the light flux guided by the means (84) at the encoder (68).
And a light reflected by the information recording medium (2).
Based on the signal from the four-divided light receiving element (70)
The difference between the jitter direction and the tracking direction of the information recording medium (2)
The deflection is detected, and the reflected light from the encoder (68) is received.
Based on the signal from the light receiving element (63) that emits light, the moving optical system (6
It is characterized in that the position detection of 9) is performed (FIGS. 3 and 4).

[0013]

According to the optical pickup device of the first aspect, the light at the center of the parallel light beam is reflected in the parallel light beam of the moving optical system.
Mirror that eliminates the luminous flux at the center.
The collimated light beam is focused on the information recording medium by the objective lens.
Used to form minute spots and reflected by the mirror
Means for separating in two directions the light beams of the central portion is provided to guide the light beam while the information recording medium, the configuration receives the reflected light by the four light-receiving element, performs deflection detection information recording medium Therefore, tilt adjustment can be performed with high accuracy, a super-resolution spot can be obtained, high-density information recording and reproduction can be performed, and the other light beam separated by the separation means can be transferred to a side surface around the moving optical system. Alternatively, the position is guided by an encoder provided at the lower portion, and the reflected light is received by a light receiving element to detect the position, so that the tilt adjustment and the position detection of the moving optical system can be performed simultaneously.

According to a second aspect of the present invention, in the optical pickup device, the mirror according to the first aspect and a central portion reflected by the mirror are provided.
Deflecting prism instead of splitting the light beam in two directions
Light in the center of the parallel light beam in the optical path from
A prism that reflects the light in two directions and splits it.
The collimated light beam whose central light beam has been removed by the
For focusing on the information recording medium to form minute spots
And one of the light beams split by the prism
Is guided to the information recording medium, and the reflected light is divided into four light receiving elements.
To detect the deflection of the information recording medium.
Light beam to the encoder, and the reflected light
In the configuration, the position is detected by receiving light at
Similar to the super-resolution spot is obtained can density information recording and reproduction, also Ru can detect the position and tilt adjustment of the movable optical system at the same time.

According to a third aspect of the present invention, there is provided an optical pickup device, comprising: a deflecting prism according to the second aspect ;
Instead of a prism that reflects light in two directions and splits it, a plane from the fixed optical system is placed at the center of the reflecting surface of the deflecting prism.
A band-shaped transmission portion that transmits the light beam in the center of the row light beam is provided,
The light flux in the central part is removed by the transmission part, and the light is reflected by the reflection surface.
The reflected parallel light beam records information by the objective lens.
A deflecting prism that condenses the light on a medium to form a minute spot, and reflects a part of the light transmitted through the transmitting portion to the deflecting prism toward an encoder, and uses the remaining light as an information recording medium. Prism that integrates a deflecting prism that reflects toward
Band-shaped transmission that transmits the central beam of the parallel light beam to the central portion
A prism) having a surface for reflecting one of the light and are separated has a half-mirror surface which separates the light transmitted therethrough have a part provided, contrary to the information recording medium side by the prism
Guides the emitted light beam onto the information recording medium and reflects the reflected light.
Detects deflection of information recording medium by receiving light with 4-split light receiving element
And reflected by the prism to the encoder side.
The reflected light beam is guided to the encoder, and the reflected light is
Since the position is detected by receiving light , a super-resolution spot can be obtained and high-density information can be recorded / reproduced in the same manner as in claim 2, and tilt adjustment and position detection of the moving optical system can be performed simultaneously. not only can, can reduce the number of parts than the movable optical system according to claim 2, it is possible to further reduce the cost.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic structural view of an essential part of an optical pickup device for magneto-optical recording and reproduction according to an embodiment of the present invention. In FIG. 1, reference numeral 69 denotes a moving optical system, 60 denotes an objective lens, 61 denotes a first mirror, 66 denotes a second mirror, 64 denotes a third mirror, 67 denotes a fourth mirror, and 65 denotes a half mirror. , 70 is 4
A divided light receiving element, 63 is a light receiving element, 62 is a deflecting prism, and 68 is an encoder. When a parallel light beam enters the moving optical system 69 from a fixed optical system (not shown), the parallel light beam is deflected by the deflection prism 62 of the moving optical system 69. Deflection prism 62
The parallel light beam deflected in the step is directed toward the objective lens 60, and the first mirror 61 kicks off the light at the center of the parallel light beam. The information recording medium 2 can be formed with a higher density. Where the first mirror
A part of the light beam reflected by 61 is split in two directions by a half mirror 65, and one light beam is guided to the information recording medium 2 by a fourth mirror 67. Then, the reflected light from the information recording medium 2 is received by the four-divided light receiving element 70, the jitter direction signal detection and the tracking direction signal detection are performed based on the signal from the four divided light receiving element 70, and the tilting mechanism is driven. Can be. The other light beam is guided to the encoder 68 by the second mirror 66 and the third mirror 64. Then, the reflected light from the encoder 68 is received by the light receiving element 63, and the position of the moving optical system 69 is detected based on the signal from the light receiving element 63, so that coarse seek for tracking can be easily performed.

Next, FIG. 2 is a schematic view of a main part of an optical pickup device for magneto-optical recording and reproduction according to a second embodiment of the present invention. Therefore, the description is omitted. In FIG. 2, reference numeral 73 denotes a prism arranged in an optical path from the deflecting prism 62 to the objective lens 60 to reflect and split the light at the center of the parallel light beam in two directions, and 74 and 71 separate ones by the prism 73. Fifth and sixth mirrors for guiding the light beam to the information recording medium 2,
Reference numerals 72 and 75 denote seventh and eighth mirrors for guiding the other light beam separated by the prism 73 to the encoder 68. In the optical pickup device having the configuration shown in FIG. 2, a prism 73 is provided in place of the mirror 61 and the half mirror 65 shown in FIG .

Next, FIG. 3 is a schematic diagram showing a main part of an optical pickup device for magneto-optical recording and reproduction according to a third embodiment of the present invention. They are the same components. In FIG. 3, reference numeral 80 designates a transmission part provided on a part of the reflection surface of the deflection prism (62) in the moving optical system 69,
The deflecting prism (62) reflects a part of the light transmitted through the transmitting portion toward an encoder 68 provided on the side surface or the lower portion around the moving optical system, and directs the remaining light toward the information recording medium 2. And a deflecting prism that reflects light. Reference numeral 81 denotes a half mirror surface of the prism 80, and 83 denotes a reflection surface of the prism 80.
80 has a surface 82 through which a part of the parallel light beam incident surface from the fixed optical system is transmitted by integrating a plurality of deflecting prisms, and has a half mirror surface 81 that separates light transmitted therethrough; The structure has a surface 83 that reflects one of the separated lights. 84 is a first deflecting prism for guiding the light beam reflected by the half mirror surface 81 of the prism 80 to the encoder 68 side to the encoder 68, and 85 is reflected by the reflection surface 83 of the prism 80 to the information recording medium 2 side. 2 shows a second deflecting prism that guides the emitted light beam onto the information recording medium. FIG. 4 is a perspective view of the prism 80 shown in FIG. 3. As described above, reference numeral 82 denotes a transmission portion of the prism 80, 81 denotes a half mirror surface, and 83 denotes a reflection surface. In the optical pickup device having the configuration shown in FIGS. 3 and 4, the deflecting prism 62 and the prism 73 shown in FIG. 2, a fifth mirror 74, and a seventh mirror are shown.
Since the role of 72 is performed by the prism 80, the number of components can be further reduced, cost can be reduced, and the moving optical system 69 can be downsized.

[0019]

As described above, according to the optical pickup device of the first aspect, the optical pickup device generates the parallel light beam in the moving optical system.
A mirror for reflecting light at the center of the parallel light beam is provided.
The parallel light beam, whose central light beam has been removed by the
For focusing on the information recording medium to form minute spots
And the central beam reflected by the mirror in two directions
A means is provided for separating the light into one of them, one of the light beams is guided to the information recording medium, and the reflected light is received by the four-divided light receiving element, and the deflection of the information recording medium is detected. A super-resolution spot is obtained to enable high-density information recording / reproduction, and the other light beam separated by the separation means is guided to an encoder provided on a side surface or a lower portion around the moving optical system. And
Since the reflected light is received by the light receiving element and the position is detected, the tilt adjustment of the moving optical system and the position detection can be performed simultaneously. Therefore, according to the present invention, the number of components of the tilt detection system of the moving optical system is reduced, the cost is reduced, and the tilt adjustment and position detection of the moving optical system are performed simultaneously with the same light source, and the super resolution is achieved. An optical pickup device capable of forming a spot can be easily provided.

Further, in the optical pickup device according to the second aspect, the mirror according to the first aspect and the mirror reflected by the mirror.
Instead of splitting the central beam in two directions, a deflection
The central part of the parallel beam in the optical path from the rhythm to the objective lens
A prism that reflects and splits the light in two directions.
The parallel luminous flux whose central luminous flux has been removed by the rhythm is
To form a minute spot
And one of the prisms divided by the prism
Guides the light beam to the information recording medium, and receives the reflected light in four splits
The device receives light and detects the deflection of the information recording medium.
Guides the other beam to the encoder and receives the reflected light
Since the position is detected by receiving light by the element, a super-resolution spot can be obtained and high-density information can be recorded / reproduced in the same manner as in claim 1, and the tilt adjustment and position detection of the moving optical system can be performed simultaneously. Ru can be done.

According to a third aspect of the present invention, there is provided an optical pickup device, comprising: a deflecting prism according to the second aspect ;
Instead of a prism that reflects light in two directions and splits it, a plane from the fixed optical system is placed at the center of the reflecting surface of the deflecting prism.
A band-shaped transmission portion that transmits the light beam in the center of the row light beam is provided,
The light flux in the central part is removed by the transmission part, and the light is reflected by the reflection surface.
The reflected parallel light beam records information by the objective lens.
A deflecting prism that condenses the light on a medium to form a minute spot, and reflects a part of the light transmitted through the transmitting portion to the deflecting prism toward an encoder, and uses the remaining light as an information recording medium. Prism that integrates a deflecting prism that reflects toward
Band-shaped transmission that transmits the central beam of the parallel light beam to the central portion
A prism) having a surface for reflecting one of the light and are separated has a half-mirror surface which separates the light transmitted therethrough have a part provided, contrary to the information recording medium side by the prism
Guides the emitted light beam onto the information recording medium and reflects the reflected light.
Detects deflection of information recording medium by receiving light with 4-split light receiving element
And reflected by the prism to the encoder side.
The reflected light beam is guided to the encoder, and the reflected light is
Since the position is detected by receiving light , a super-resolution spot can be obtained and high-density information can be recorded / reproduced in the same manner as in claim 2, and tilt adjustment and position detection of the moving optical system can be performed simultaneously. not only can, can reduce the number of parts than the movable optical system according to claim 2, it is possible to further reduce the cost and size.

[Brief description of the drawings]

FIG. 1 is a schematic structural view of an essential part of an optical pickup device for magneto-optical recording and reproduction according to an embodiment of the present invention.

FIG. 2 is a schematic structural view of an essential part of an optical pickup device for magneto-optical recording and reproduction according to an embodiment of the present invention;

FIG. 3 is a schematic structural view of an essential part of an optical pickup device for magneto-optical recording and reproduction according to an embodiment of the present invention;

FIG. 4 is a perspective view of the prism shown in FIG. 3;

FIG. 5 is a perspective view of an optical head optical system having a tilt mechanism according to the related art.

FIG. 6 is a block diagram showing an optical disc device provided with the optical head tilt mechanism of FIG. 5;

FIGS. 7A and 7B are explanatory diagrams of a conventional technique, in which FIG. 7A is a perspective view showing a schematic configuration of a conventional deflection detector, and FIG. 7B is a circuit diagram showing a signal detection circuit of the deflection detector.

[Explanation of symbols]

2 Information recording medium 60 Objective lens 61 First mirror 62 Deflection prism 63 Light receiving element 64, 66, 72, 75 Mirror (light flux guide to encoder) Means) 65 Half mirror (beam splitting means) 67, 71, 74 Mirror (beam guiding means for information recording medium) 68 Encoder 69 Moving optical system 70 split into four Light receiving element 73: prism (light beam separation means) 80: prism (prism integrating a plurality of deflection prisms) 81: half mirror surface 83: reflection surface 84: first deflection prism (Light flux guiding means to encoder) 85 ... second deflecting prism (light flux guiding means to information recording medium)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G11B 7/085 G11B 7/09 G11B 7/095 G11B 7/135

Claims (3)

(57) [Claims] 1. A fixed optical system collimating lens is arranged to collimate light from a light source, parallel from said fixed optical system
Separated light comprising a movable optical system in which the objective lens is arranged to irradiate condenses the light deflected by the deflecting prism and the deflecting prism for deflecting the light beam emitted by the light beam on the information recording medium In the pickup device, light in a central portion of the parallel light beam in the parallel light beam of the moving optical system may be used.
Is provided with a mirror that reflects the
The collimated light beam from which the information has been
It is focused on the body and used to form minute spots, and
Means for separating the central light beam reflected by the mirror in two directions, means for guiding one of the separated light beams onto the information recording medium, and light reflected by the information recording medium of the light beam guided by the means. A four-divided light receiving element for receiving
Means for guiding the other light beam separated by the separating means to an encoder provided on a side surface or a lower portion around the moving optical system, and light receiving for receiving reflected light of the light beam guided by the means at the encoder And an element for receiving light reflected by the information recording medium.
Based on the signal from the light receiving element, the information recording medium
Detection of deflection in the data direction and tracking direction.
The signal from the light receiving element that receives the reflected light from the encoder
An optical pickup device for detecting the position of a moving optical system based on the detected position . Wherein a fixed optical system collimating lens is arranged to collimate light from a light source, parallel from said fixed optical system
Separated light comprising a movable optical system in which the objective lens is arranged to irradiate condenses the light deflected by the deflecting prism and the deflecting prism for deflecting the light beam emitted by the light beam on the information recording medium In the pickup device, the objective from the deflection prism in the moving optical system may be used.
In the optical path to the lens, the light at the center of the parallel light beam is
A prism that reflects and splits is provided, and the prism
The parallel beam excluding the central beam is converted by the objective lens.
The light is condensed on an information recording medium and used to form a minute spot, and
One, a means for guiding one of the light fluxes divided by the prism onto the information recording medium, and the four light-receiving element for receiving reflected light from the information recording medium of the light beam guided by the means, by the prism Means for guiding the other split light beam to the encoder provided on the side surface or the lower portion around the moving optical system, and a light receiving element for receiving light reflected by the encoder of the light beam guided by the means is provided . Light reflected by the information recording medium
Based on the signal from the four-segment light-receiving element that receives light.
Detection of Jitter and Tracking Direction of Information Recording Medium
To receive the reflected light from the encoder
The position of the moving optical system is detected based on the signal from the element.
Cormorant that optical pickup apparatus according to claim. 3. A fixed optical system collimating lens is arranged to collimate light from a light source, parallel from said fixed optical system
Separated light comprising a movable optical system in which the objective lens is arranged to irradiate condenses the light deflected by the deflecting prism and the deflecting prism for deflecting the light beam emitted by the light beam on the information recording medium In the pickup device, the inside of the reflecting surface of the deflecting prism in the moving optical system
In the central part, the central part of the parallel light from the fixed optical system
A transparent band-shaped transmission part is provided, and the transmission part
The parallel luminous flux reflected by the reflecting surface after removing the luminous flux is
The objective lens condenses light onto the information recording medium and
The deflection prism and the remaining light are used to form a slit and reflect a part of the light transmitted through the transmission part to the deflection prism toward an encoder provided on a side surface or a lower part around the moving optical system. A prism integrated with a deflecting prism that reflects toward the information recording medium, and means for guiding a light beam reflected by the prism toward the information recording medium onto the information recording medium; and A four-divided light receiving element for receiving the reflected light of the reflected light beam from the information recording medium, a unit for guiding the light beam reflected by the prism to the encoder side to the encoder, and an encoder for the light beam guided by the unit. a light receiving element is provided, the information for receiving the reflected light
From a 4-segment light-receiving element that receives the reflected light from the information recording medium
And the jitter direction of the information recording medium based on the signal of
Detects the deflection in the locking direction and uses the encoder to
Moves based on the signal from the light receiving element that receives the reflected light
An optical pickup device for detecting the position of an optical system.