JP2718326B2 - Optical pickup - 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 for reading or writing information from a compact disk or a recording / reproducing optical disk.

[0002]

2. Description of the Related Art It is desired to reduce the size of an optical disk device for recording and reproducing information by using laser light, and attempts have been made to reduce the size and weight of an optical pickup. Reducing the size and weight of the optical pickup is advantageous not only for reducing the size of the entire device, but also for improving the performance such as shortening the access time.
2. Description of the Related Art In recent years, optical pickups have been reduced in size and weight by using hologram optical elements, and some of them have been put to practical use.

Hereinafter, an optical pickup using a conventional hologram optical element will be described. JP-A-1-155
No. 529 discloses a grating for separating a reciprocating optical path, a micro Fresnel lens formed on a silicon oxide film on the grating, and a reflection hologram for obtaining a focus error and a tracking error. Is formed.

[0004] Similarly, in Japanese Patent Application Laid-Open No. 62-146444, a zone plate for condensing a laser beam on an information holding surface of an optical disk, a polarizing beam splitter for separating a reciprocating path, and astigmatism are obtained. Zone plates are separately configured.

Japanese Patent Application Laid-Open No. 63-20737 discloses a hologram for condensing light on an optical disk,
A hologram for reciprocating path separation and adding a aberration and detecting a focus error are provided.

[0006] In addition, those described in JP-A-2-81335 and JP-A-1-220145 include a surface of a refraction type objective lens (JP-A-2-81335) or an inner surface thereof (JP-A-1-220145). ), A hologram for round-trip separation, focus, and tracking error detection is arranged.

[0007]

However, in the above-mentioned conventional optical pickup, Japanese Patent Application Laid-Open No. 1-155529 has been disclosed.
In the method disclosed in Japanese Patent Application Publication No. H11-157, a grating having a reciprocating path separating function and a micro Fresnel lens are formed on different members with a silicon oxide film interposed therebetween in a separate process. The micro-Fresnel lens and the grating are configured in different areas, and those described in Japanese Patent Application Laid-Open No. Sho 62-146444 include a zone plate for condensing laser light on an information holding surface of an optical disc, a polarizing beam splitter, Since the zone plates for obtaining astigmatism are separately formed, Japanese Patent Application Laid-Open Nos. 1-155529 and 62
Japanese Patent Application Laid-Open No. 146444 has a problem that a required optical path length is long, miniaturization of elements is difficult, and positional accuracy between elements must be managed. Japanese Unexamined Patent Application Publication No. 63-20737 discloses that the two holograms are laminated and used.
Although it is superior to the two conventional examples, it has a problem that two holograms must be separately formed and their positional accuracy must be managed. On the other hand, JP-A-2-813
It is actually very difficult to form a hologram pattern on the curved surface of the objective lens in the device described in JP-A-35-35, and in JP-A-1-214545, a hologram is formed between the upper and lower objective lenses. Due to the formation, there is a problem that the performance of the objective lens is degraded due to an alignment error between the upper and lower members and the number of steps such as bonding increases.

The present invention solves the above-mentioned conventional problems.
, Small and thin optical pickup with easy positioning accuracy management
It is intended to provide.

According to the present invention, in order to solve the above-mentioned problems, a part of light from a light emitting element is reflected at an end face,
A prism that allows a part to enter inside from its end face,
Light incident on the prism from one end face and emitted from the other end face
And a first light receiving means for receiving the light,
After that, it was led to the optical disk and reflected from the optical disk
Separation means that reflects part of the light and transmits part of the light, and a separating hand
Second light receiving means for receiving light transmitted through the step, and separating means
Reflection means for reflecting the light reflected by the reflector, and reflection by the reflection means
A third light receiving means for receiving the emitted light, a light emitting element,
The first light receiving means, the second light receiving means and the third light receiving means
An opening is provided for storing and at least the area where light passes
The storage member in which is formed and the opening of the storage member are closed.
A cover member for sealing the inside of the storage member, and a storage member
And at least a first light receiving means and a second light receiving means
Lead end electrically connected to the step and the third light receiving means
A first light receiving means, a second light receiving means, and a third light receiving means.
Are formed on substantially the same plane as the light receiving means.
The lead terminals were disposed substantially parallel to the plane.

[0009]

According to the present invention, the length from the bottom surface of the housing member of the optical pickup to the light emitting surface from which light is emitted can be shortened.

[0010]

【Example】

(Embodiment 1) A first embodiment of the present invention will be described below with reference to the drawings. FIG. 1A is a schematic configuration diagram of an optical pickup according to a first embodiment of the present invention.
(C) is a diagram showing a first hologram pattern, FIG.
FIG. 1D shows a second hologram pattern, FIG.
(B) is a diagram showing a superimposed pattern of the first hologram pattern and the second hologram pattern.

First, from a semiconductor laser which is a light emitting element,
FIG. 1 (a) shows the optical path on the outward path to the optical disk.
This will be described with reference to (b), (c), and (d). FIG. 1 (a)
2, the laser beam 3 emitted from the semiconductor laser chip 2 fixed to the lower surface 1a of the transparent glass member 1 reaches the composite hologram 4 formed on the upper surface 1b of the glass member 1 while diffusing. FIG. 1 shows the composite hologram 4.
As shown in (b), two types of hologram patterns are superimposed and drawn. As shown in FIG. 1C, one of the two types of hologram patterns is concentric and the pitch becomes smaller toward the outer periphery, and the diffused light 3 is collected as a spot 8 on the information recording surface 7a of the optical disk disk 7. As shown in FIG. 1D, the first hologram pattern that emits light converts the reflected light of the spot 8 into convergent light 10 and diffracts and condenses the light into a four-divided light receiving sensor 9. It is a second hologram pattern having a function. This second hologram pattern generates astigmatism at the same time as the light condensing function, and has a configuration in which the calculated value of the output of the light receiving sensor 9 becomes 0 at the time of focusing, which is known as the astigmatism method.

In this manner, the light is focused on the second hologram pattern.
By adding the function, the second hologram pattern
The optical path length of the reflected light passing through the sensor to the light receiving sensor
Further miniaturization of the optical pickup
Can be realized. FIG. 2 shows a change in the irradiation shape of the convergent light 10 on the light receiving sensor 9 formed by the second hologram pattern 4b.
Are designed to satisfy the requirements of a focus error signal (FE) described below.

The light receiving sensor 9 is divided into four parts 9a, 9b, 9c, and 9d.
a), I (9b), I (9c) and I (9d), and the focus error signal (FE) is defined as in (Equation 1).

[0014]

(Equation 1)

Now, the spot 8 is accurately focused on the information recording surface 7a of the optical disk 7 and the light receiving sensor 9 at that time
If the upper irradiation shape is 5, FE becomes (Equation 2).

[0016]

(Equation 2)

The output of the operational amplifier 16 at this time is 0. Next, assuming that the irradiation shape when the distance between the optical disk 7 and the upper surface 1b of the glass member 1 is close to the in-focus state is 5a, F.E.

[0018]

(Equation 3)

Assuming that the irradiation shape when moving away is 5b, F.E. becomes (Equation 4).

[0020]

(Equation 4)

(Embodiment 2) Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a schematic configuration diagram of an optical pickup according to a second embodiment of the present invention. In FIG. 3, a semiconductor laser chip 14 is horizontally mounted on a sensor substrate 13 on which a first light receiving sensor 11 and a second light receiving sensor 12 are formed. Similarly, the reflecting prism 15 for raising the optical path is also mounted on the sensor substrate 13 so that its reflecting surface faces the light emitting surface of the semiconductor laser chip 14. FIG. 4 is an enlarged view showing the structure near the semiconductor laser chip 14 and the reflecting prism 15 in FIG. The reflecting prism 15 is trapezoidal,
The reflecting surface 15a is coated with a semi-transmissive film that transmits a part of the light emitted from the semiconductor laser chip 14 into the reflecting prism 15. A monitor sensor 49 is formed on the sensor base 13 at a portion in contact with the bottom surface of the reflection prism 15. The monitor sensor 49 constantly monitors a change in the amount of light of the semiconductor laser chip 14 and feeds back information to a control circuit. Conventionally, the semiconductor laser chip 14
Although the amount of light emitted from the rear surface 14a has been monitored, the light emitted from the rear surface 14a causes stray light to other light receiving sensors (the first light receiving sensor 11, the second light receiving sensor 12, etc.). In the configuration of the present invention, since the light is taken into the reflection prism 15, there is an advantage that the influence on other light receiving sensors can be reduced. The laser beam emitted from the semiconductor laser chip 14 is obliquely incident on the entrance window 17 provided on the second surface 18 b of the light guide member 18 by the reflecting prism 15, and becomes a laser beam 19. By using the reflection prism 15, the semiconductor laser chip 14 can be connected to the sensor substrate 1.
3 can be mounted horizontally, which is advantageous in terms of wiring and heat radiation, and has the advantage that the angle of incidence on the light guide member 18 can be set with high accuracy.

As described above, the first light receiving sensor 11, the second
The light receiving sensor 12 and the monitor sensor 49 are almost the same.
Necessary for arranging each sensor by arranging it on a flat surface
Space can be reduced, especially for optical pickups.
Will greatly contribute to reducing the thickness of the
You. Further, a first light receiving sensor 11 and a second light receiving sensor 12
And the monitor sensor 49 on the same sensor substrate 13
By placing them, compared to placing them separately
Thus, the number of parts can be reduced. In addition, due to quality control during manufacturing,
The relative positions of the three sensors accurately
Position to determine the sensor installation position.
Optical pickup that can greatly simplify the adjustment process.
Production cost can be reduced. The light intensity distribution of the light emitted from the semiconductor laser is usually elliptical. Therefore, if the minor axis of the ellipse of the light quantity distribution is set within the plane formed by the optical axis in the optical path from the semiconductor laser chip 14 to the composite hologram 24, light enters the composite hologram 24 obliquely. The light quantity distribution can be made closer to a circle. By making the light amount distribution closer to a circle, the shape of the light condensed on the optical disk 26 via the composite hologram 24 can be made substantially circular, and the shape of the light converged on the optical disc disk 26 becomes smaller than that when the light is condensed in an elliptical shape. It is possible to prevent the signal of the information recorded on the track or adjacent thereto from being mixed into the reproduction signal, thereby preventing the signal characteristics of the reproduction signal from deteriorating.

Next, on the first surface 18a facing the optical disk 26 on the upper surface of the light guide member 18, a laser beam 19
There is a first reflecting portion 21 that reflects the laser light 20 toward the second surface 18b. Further, the laser light 20 is provided on the second surface 18b.
There is a second reflecting portion 23 that reflects the laser light 22 toward the first surface 18a again. The laser beam 22 reflected by the second reflector 23 is obliquely incident on the composite hologram 24 formed on the first surface 18a and near the first reflector 21.

FIG. 5 illustrates the pattern of the composite hologram 24. As shown in FIG. 5A, the composite hologram 24 has the first hologram pattern 24a shown in FIG. 2), the laser beam 22 obliquely incident on the composite hologram 24 is converted into convergent light 25 by the first hologram pattern 24a. Is focused as a spot 27 on the information recording surface 26a of the optical disk board 26.

Next, the return path from the optical disk 26 will be described. The reflected light from the spot 27 travels in the same optical path as the convergent light 25 in the opposite direction as diffused light, and reaches the composite hologram 24. The diffused light reaching the composite hologram 24 is the second hologram pattern 2 of the composite hologram 24.
The light is converted into a diffraction convergent light 28 by 4b. On the second surface 18b of the light guide member 18, there is formed a semi-transmissive window 29 that transmits about 50% of the diffraction convergent light 28 and reflects about the remaining 50%. Due to the function of the semi-transmission window 29, the diffraction convergent light 28 is split into a semi-transmission light 30 arriving at the first light receiving sensor 11 and a reflected light 31. First surface 18a of light guide member 18
The reflected light 31 is reflected light 3 heading toward the second surface 18b again.
A reflection film 33 for converting the light into 2 is formed. A transmission window 34 for guiding the reflected light 32 to the second light receiving sensor 12 is provided on the second surface 18 b of the light guide member 18. The diffraction converging light 28 is designed such that a focal point 35 exists between the semi-transmission window 29 and the transmission window 34.

The input and output of various signals to and from the sensor board 13 are as follows.
This is performed via the lead frame 36. Reference numeral 37 denotes a package made of a non-conductive material such as resin and ceramics. Here, as shown in FIG.
At least in the vicinity of the sensor substrate 13 in the package 37.
It is pulled substantially parallel to the sensor substrate 13. Like this
With this configuration, the lead frame 36 is
Minimizing the ratio of the ridge 37 in the thickness direction
The package 37 can be made thinner, and
This contributes to making the overall backup thinner. More
Light of the lead frame 36 extracted from the package 37
Minimize protrusion of the pickup in the thickness direction
Also greatly contributes to making the optical pickup thinner.
To offer. In this embodiment, the input / output lines are reset.
Although it was formed with a metal frame, the conductive material was added to the package.
Fees and the like may be printed and provided. The space 38 surrounded by the light guide member 18 and the package 37 is usually filled with an inert gas such as nitrogen gas, but may be filled with a transparent resin or the like as needed. This allows it to be stored inside the package
Semiconductor laser chip 14 and various sensors
Can be prevented, the semiconductor laser chip 14
Deterioration due to oxidation etc. of various sensors can be prevented and high reliability
Optical pickup.

Next, the shapes of the first light receiving sensor 11 and the second light receiving sensor 12 and the principle of signal detection will be described with reference to FIG. The first light-receiving sensor 11 and the second light-receiving sensor 12 have four portions 11a, 11b, respectively.
11c, 11d, and 12a, 12b, 12c, 12
d. In addition, the first light receiving sensor 11, the second
Parts 11a, 11b, 11c, 1
The currents from Id and 12a, 12b, 12c, and 12d are I (11a), I (11b), and I (11
c), I (11d), and I (12a), I (12
b), I (12c) and I (12d). As can be seen from the circuit diagram of FIG. 6, the focus error signal (F.
E.), the tracking error signal (TE), and the RF signal (RF) have a circuit configuration obtained by the following (Equation 5), (Equation 6), and (Equation 7). Has become.

[0028]

(Equation 5)

[0029]

(Equation 6)

[0030]

(Equation 7)

The focus error signal (FE), tracking error signal (TE), and RF signal (RF)
Of these, the focus error signal (FE) will be further described.

Now, the information recording layer 26a of the optical disk board 26
When the spot 27 of the composite hologram 24 is accurately focused, and the irradiation shapes of the laser beams on the first light receiving sensor 11 and the second light receiving sensor 12 in this focused state are 39a and 40a, respectively. The irradiation position of the laser light to the first light receiving sensor 11 and the second light receiving sensor 12 is set so that the focus error signal (FE) becomes (Equation 8).

[0033]

(Equation 8)

Next, when the distance between the optical disk 26 and the first surface 18a is close from the in-focus state, the irradiation shapes of the laser beams on the first light receiving sensor 11 and the second light receiving sensor 12 are 39c, respectively. 40c, and the focus error signal (FE) becomes (Equation 9).

[0035]

(Equation 9)

Conversely, when the distance between the optical disk 26 and the first surface 18a is far from the in-focus state, the first light receiving sensor 11
And the irradiation shape of the laser beam on the second light receiving sensor 12 becomes 39b and 40b, and the focus error signal (F.
E) becomes (Equation 10).

[0037]

(Equation 10)

The above-described focus error detection method is known as a spot size method. As a tracking error detection method, a push-pull method is known.

By designing the focal point 35 of the diffracted convergent light 28 so as to exist between the semi-transmissive window 29 and the transmissive window 34, a focus error can be detected by an astigmatism method that is often used in the related art. In comparison with the above, a complicated hologram pattern for generating astigmatism is unnecessary, and the second hologram pattern 24b of the composite hologram 24 is a very simple pattern of only focusing.

FIGS. 7 and 8 show a configuration in which a focus error detection system which is simpler than the spot size method is used. 7A, a semi-transmissive film 48 is coated on the second surface 18b of the light guide member 18, and a diffusion film 41 and a light-shielding film 42 are further coated on the outside thereof. The shape of the diffusion film 41 is an annular zone as shown in FIG. 7B. When the inner diameter is d and the outer diameter is D, the inner diameter d and the outer diameter D are semi-transmissive films of the diffraction convergent light 28. The diameter H on the reference numeral 48 is determined so as to satisfy the relationship of (Equation 11).

[0041]

[Equation 11]

This is because the semi-transmitted light in the range from d to H is diffused by the diffusion film 41 and does not affect the reflected light 31. For such a purpose, the diffusion film 41 may be an absorption film that absorbs laser light. The semi-transmitted light 30 transmitted through the inner diameter side of the inner diameter d of the diffusion film 41 reaches the first light receiving sensor 46.

FIG. 8 shows the reflected light 32 incident on the second light receiving sensor 47. The second of the light guide member 18
The surface 18b is coated with a light shielding film 44 to form a transmission window 43 smaller than the diameter of the reflected light 32. This light-shielding film 44 may of course be coated as a region continuous with the light-shielding film 42 of FIG. FIG. 8B shows reflected light 3.
2 represents the size of the diameter when reaching the second surface 18b and the diameter of the transmission window 43. Transmitted light 4 from transmission window 43
5 reaches the second light receiving sensor 47.

When the focus error detection method of this type is used, the first light receiving sensor 46 and the second light receiving sensor 47 are divided like the first light receiving sensor 11 and the second light receiving sensor 12 in FIG. The first light receiving sensor 46 and the second light receiving sensor 47 having a light receiving area large enough to receive the semi-transmitted light 30 and the transmitted light 45 need not be provided.
Can be used as a focus error signal. FIG. 9 shows the respective outputs of the first light receiving sensor 46 and the second light receiving sensor 47, and the first light receiving sensor 46.
And the second light receiving sensor 47.

In this focus error detection method, since the multi-segment light receiving sensor as shown in FIG. 6 is not used, fine position adjustment between the first light receiving sensor 46, the second light receiving sensor 47 and the irradiation shape of the laser light is performed. Is unnecessary, and is excellent in productivity and long-term stability.

In each of the configurations shown in FIG. 3 and FIGS. 7 and 8 described in the second embodiment of the present invention, the entrance window 17, the semi-transmission window 29, and the transmission window Portions other than the window 34 and the transmission window 43 are connected to the light guide member 18.
When the light shielding film 42 is coated and used over the entire second surface 18b, the influence of various stray light generated in the light guide member 18 on the light receiving sensor can be significantly reduced, and the S / N ratio of the signal can be reduced. Is improved. This light shielding film 42
May be coated with the same material as the reflection film of the second reflection portion 23 instead.

[0047]

As described above, the present invention provides a lead frame
Is substantially parallel to the sensor substrate.
Of the lead frame in the package thickness direction.
Package can be minimized,
Contributes to thinning and, consequently, the overall thickness of the optical pickup
Will be. Leads further pulled out of the package
Minimize the protrusion of the frame optical pickup in the thickness direction.
The optical pickup is also thin because it is kept to a minimum.
Will greatly contribute to the development of In addition, light receiving sensor and
The monitor is located on the same plane.
Space required for placing each sensor in the optical pickup
The amount can be smaller, especially for optical pickups
This will greatly contribute to reducing the thickness. Further
Light receiving sensor and monitor sensor on the same sensor board
The arrangement of the
In addition, the number of parts can be reduced. Also a sensor for the substrate
Phase of three sensors only by quality control at the time of manufacture
Since the relative position can be accurately determined, the sensor
Significantly simplifies the position adjustment process for determining the installation position
Can reduce the production cost of optical pickups
it can.

[Brief description of the drawings]

FIG. 1A is a schematic configuration diagram of an optical pickup according to a first embodiment of the present invention. FIG. 1B is a diagram illustrating a first hologram pattern and a second hologram pattern of the optical pickup according to the first embodiment of the present invention. (C) is a diagram showing a first hologram pattern of the optical pickup according to the first embodiment of the present invention. (D) is a second hologram of the optical pickup according to the first embodiment of the present invention. Diagram showing pattern

FIG. 2 is a diagram showing a change in an irradiation shape of convergent light on a light receiving sensor formed by a second hologram pattern of the optical pickup according to the first embodiment of the present invention;

FIG. 3 is a schematic configuration diagram of an optical pickup according to a second embodiment of the present invention.

FIG. 4 is an enlarged view of the vicinity of a semiconductor laser chip and a reflecting prism of an optical pickup according to a second embodiment of the present invention.

FIG. 5A is a diagram showing a superposition pattern of a first hologram pattern and a second hologram pattern of an optical pickup according to a second embodiment of the present invention. FIG. 5B is a diagram showing a superposition pattern of the second embodiment of the present invention. FIG. 4C shows a first hologram pattern of the optical pickup. FIG. 5C shows a second hologram pattern of the optical pickup according to the second embodiment of the present invention.

FIG. 6 is a diagram illustrating a shape of a light receiving sensor of an optical pickup and a signal processing circuit according to a second embodiment of the present invention.

FIG. 7A is an enlarged view of the vicinity of a first light receiving sensor when a simple focus error detection method of an optical pickup according to a second embodiment of the present invention is used, and FIG. 7B is a second embodiment of the present invention. FIG. 7 is a diagram illustrating a shape of a diffusion film when a simple focus error detection method of an optical pickup according to an embodiment is used.

FIG. 8 (a) is an enlarged view of the vicinity of a second light receiving sensor when a simple focus error detection method of an optical pickup according to a second embodiment of the present invention is used, and FIG. 8 (b) is a second embodiment of the present invention. FIG. 9 is a diagram illustrating the size of the diameter of the reflected light and the diameter of the transmission window when the simple focus error detection method of the optical pickup in the embodiment is used.

FIG. 9 is an explanatory diagram of an output signal of a light receiving sensor when a simple focus error detection method of an optical pickup according to a second embodiment of the present invention is used.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 glass member 2 semiconductor laser chip 4 composite hologram 7 optical disk 8 spot 9 light receiving sensor 11 first light receiving sensor 12 second light receiving sensor 13 sensor substrate 15 reflecting prism 18 light guide member 21 first reflecting portion 23 second reflecting portion 24 composite hologram 29 semi-transmissive window 34 transmissive window 41 diffusion film 42 light-shielding film

Claims (11)

(57) [Claims] A light emitting element for irradiating an optical disk with light;
A part of the light from the light emitting element is reflected at the end face, and a part is
A prism that enters the interior from the end face, and from the end face
Light incident on the prism and emitted from the other end face is received.
A first light receiving unit that emits light,
After that, it was led to the optical disk and reflected from the optical disk
Separating means for reflecting part of the light and transmitting part of the light;
Second light receiving means for receiving light transmitted through the separating means;
Reflecting means for reflecting the light reflected by the separating means;
Third light receiving means for receiving the light reflected by the light emitting means
The light emitting element, the first light receiving means, and the second light receiving element.
The light means and the third light receiving means are housed and
An opening is formed in the area through which light passes
A member and an opening of the storage member are closed, and the storage member is closed.
A cover member for sealing the inside, and a cover member provided on the storage member.
And at least the first light receiving means and the second light receiving means.
A lead electrically connected to the step and the third light receiving means;
And a second terminal, the first light receiving means and the second light receiving means.
Means and the third light receiving means are formed on substantially the same plane
And the lead terminals are substantially parallel to the plane.
An optical pickup characterized by being provided . 2. The optical pickup according to claim 1, wherein the housing member is characterized that you have formed a non-conductive material. 3. An optical disk drive comprising a semiconductor substrate and lead terminals.
The optical pickup of claim 1, wherein that you have been configured substantially parallel to the. 4. A light emitting element for irradiating an optical disk with light,
An optical unit that guides the light reflected by the optical disk to a predetermined position
Material, provided opposite to the optical member, from the optical member
A first light receiving means for receiving the emitted light and a second light receiving means;
Light receiving means, at least the first light receiving means and the
A semiconductor substrate on which two light receiving means are formed;
An element, the first light receiving means, and the second light receiving means.
At least in the area where light passes
The formed storage member and the opening of the storage member are closed.
A cover member for sealing the inside of the storage member.
An optical disc is provided between the optical member and the semiconductor substrate.
The separation means that reflects part of the light from the board and transmits part of the light
And the opposite side of the optical member from the separation means .
A reflecting hand for reflecting the light reflected by the separating means is provided on the end face.
A step is formed, and between the separating means and the,
An aperture smaller than the diameter of the light transmitted through the separation means
And block a part of the light transmitted through the separating means.
Light shielding means is formed, further comprising the separating means and the semiconductor
Between the substrate and the substrate, the diameter of the light reflected by the reflection means.
Has a small aperture and has been reflected by the reflection means
Optical pickup you characterized by light shielding means for shielding a part of light is formed. 5. A light shielding means comprising a diffusion film or a light absorbing film.
The optical pickup according to claim 4, wherein the optical pickup is formed on one of them. 6. A light emitting element for irradiating an optical disk with light,
A part of the light from the light emitting element is reflected at the end face, and a part is
A prism that enters the interior from the end face, and from the end face
Light incident on the prism and emitted from the other end face is received.
A first light receiving unit that emits light,
After that, it was led to the optical disk and reflected from the optical disk
Separating means for reflecting part of the light and transmitting part of the light;
Second light receiving means for receiving light transmitted through the separating means;
Reflecting means for reflecting the light reflected by the separating means;
Third light receiving means for receiving the light reflected by the light emitting means
The light emitting element, the first light receiving means, and the second light receiving element.
The light means and the third light receiving means are housed and
An opening is formed in the area through which light passes
A member and an opening of the storage member are closed, and the storage member is closed.
A cover member for hermetically sealing the inside,
Step, the second light receiving means and the third light receiving means.
Light beep <br/> up you characterized in that it is formed on the same plane pot. 7. Based on an output signal from the first light receiving means.
The light-emitting element is controlled, and the second light-receiving means and the third light-receiving means are controlled.
7. The optical pickup according to claim 6, wherein the focus error signal is formed using optical means . 8. A first light receiving means, a second light receiving means, and a third light receiving means.
8. The optical pickup according to claim 6, wherein said light receiving means is formed on the same semiconductor substrate . 9. The optical pickup according to claim 8, wherein a light emitting element is provided on the semiconductor substrate . 10. The method of claim 8, 9 optical pickup of any 1, wherein the provision of the prism on a semiconductor substrate. 11. The method of claim 6-10 optical pickup of any 1, wherein the encapsulating internal inert gas of the housing member.