JPH10283670A - Optical pickup - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent contamination of a translucent cover during an assembling process and to maintain a good optical characteristic by pasting a protective film on the surface of the translucent cover, which covers the translucent opening section of the package that stores the element main body of an optical composite element, in a strippable manner and removing the film in the last assembling process of the optical pickup. SOLUTION: A protective film 13 is pasted on the surface of a translucent cover 12 which is fitted and fixed to an opening section 11a of a flat package 11, that is the package of an optical composite element 10, and is made of transparent glass plates. Then, the package 11 is mounted on the pickup to conduct the assembly of the pickup in the condition above. During the last assembling process of the pickup, the film 13 is peeled and removed from the cover 12. Thus, contamination of the cover 12 during the assembling process is stopped, deterioration of the optical characteristic of the element 10 is prevented and the light emitting and the receiving against the objective lens side are surely conducted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical pickup provided in an optical disk recording and / or reproducing apparatus, a magneto-optical disk recording / reproducing apparatus and the like.

[0002]

2. Description of the Related Art Conventionally, an optical pickup is provided alone in an optical disk recording and / or reproducing apparatus, and is combined with a magnetic head as an overwrite head in a recording and reproducing apparatus for a magneto-optical disk capable of recording and reproducing. Provided as an optical magnetic head mechanism.

The optical system of this optical pickup includes a so-called laser coupler element in which a light emitting element such as a semiconductor laser and a microprism are formed on an optical composite element, for example, a substrate on which a photodiode is formed as a light receiving element. Some use a so-called configuration. FIG. 6 shows an example of such an optical composite element.

The element body 21 of the optical composite element 20 is
A so-called laser coupler element is formed by integrating a light emitting element including a semiconductor laser LD, a light receiving element including photodiodes PD ₁ and PD ₂ , and a microprism.

[0005] Two photodiodes (PDs) divided so as to be able to detect a desired signal as a light receiving element, for example, an RF signal, a focus error signal, a tracking error signal, etc., by diffusing impurities into a semiconductor substrate or the like.
₁ , PD ₂ ) to form a photodiode IC (integrated circuit) 24. This photodiode IC
24 on the surface on which the divided photodiodes PD ₁ and PD ₂ are formed, the photodiodes PD ₁ and PD ₂
And a micro prism element 28 is joined by a transparent resin adhesive 27.

On the other hand, on a portion of the photodiode IC 24, PD the monitoring photodiode PD _M for monitoring the output of the laser is formed (photodiode) substrate 2
6 are joined by a silver paste 25, and a semiconductor laser LD is formed as a light emitting element on a part of the PD substrate 26.

The semiconductor laser LD, the divided photodiodes PD ₁ and PD ₂ and the microprism element 28 constitute a laser coupler element. The photodiode IC 24 having the laser coupler element is mounted on a part of a base substrate (circuit substrate) 22 formed of a POP base substrate, a ceramic substrate, or the like by a conductive adhesive 23, so that the element main body 21 is formed. It is configured.

Further, a light-transmitting cover 29 for protecting the element body 21 covers the elements and a base substrate 22.
It is attached on the top with an adhesive or the like. With the above-described configuration, the integrated composite optical composite element 20 is configured.

The micro-prism element 28 of the optical composite element 20 has a trapezoidal column shape in which a part of a rectangular parallelepiped is cut off to form a 45 ° inclined surface, and the 45 ° reflecting surface 2 formed by the inclined surface is used.
8a, a semi-transmissive film is formed, and a reflection surface 28b is formed on the upper surface by a total reflection film.

[0010] The semiconductor laser LD laser beam emitted from, i.e., outgoing light L _F is reflected upward by 45 ° reflecting surface 28a of the micro prism element 28. The light flux of the reflected emitted light L _F is incident on the objective lens 31 passes through the translucent cover 29, the objective lens 31, the disk substrate 34 the light beam incident on the signal recording surface 33 of the optical disk 32 And is condensed and irradiated.

An optical disk 32 is formed by the objective lens 31.
The light beam condensed on the signal recording surface 33 is reflected with its intensity modulated according to the signal recorded on the signal recording surface 33. The reflected return light L _R passes through the same path as the output light L _F, and passes through 45 ° of the micro prism element 28.
Transmitted through the semi-transparent film of the reflecting surface 28a, it is incident on one of the divided photodiode PD _2. In this split photodiode PD _2, together with the photodetection of the returned light L _R Nasaru, part of the return light L _R is reflected, it is reflected by the total reflection film of the reflection surface 38b of the microprism elements 38, the other split incident on the photodiode PD _1, wherein the signal of the light receiving detection is made.

Two divided photodiodes PD ₁ and PD
By performing signal processing by adding, comparing, and the like, the signals detected in step _2, a read signal (RF signal), a focus error signal, a tracking error signal, and the like of an information signal from the optical disk 32 can be obtained.

[0013]

As described above, in an optical pickup using an optical composite element, a so-called laser coupler element, in the optical system, light emitted from the element and light returned from the optical disk are covered by a light-transmitting cover. Since the light is transmitted, the surface of the light-transmitting cover is contaminated, which causes deterioration of optical characteristics and hinders reading of information signals from the optical disk.

The so-called stain on the surface of the light transmitting cover of the laser coupler element may occur during the assembly process of the optical pickup. That is, in the process of assembling the optical pickup, the light-transmitting cover of the laser coupler element attaches the solder flux when soldering the flexible wiring board or the like, attaches the cleaning residue of the ultraviolet curable adhesive used for attaching each member, or In addition, there is a possibility that the adhesive may be stained due to whitening of the instant adhesive against cleaning traces caused by alcohol.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and in a process of assembling an optical pickup, a light transmitting cover for covering an optical composite element of an optical system is prevented from being stained to maintain good optical characteristics. It is an object of the present invention to provide an optical pickup adapted to be used.

[0016]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to an optical pickup using an optical composite element comprising a light receiving element, a microprism means, and a light emitting element in an optical system. The protective film is stuck on the surface of the light-transmitting cover that covers the light-transmitting opening of the package in which the element body is stored, and is peeled off in the final assembly step of the optical pickup.

With this configuration, the light-transmitting cover of the optical composite element is prevented from being stained by the protective film by the adhesion of the solder flux and the adhesive for bonding each member in the assembling process of the optical pickup. Is prevented from deteriorating the optical characteristics.

The present invention provides the protective film,
An adhesive layer is provided so as to be detachably adhered to the surface of the light-transmitting cover so as to cover the surface of the light-transmitting cover.
Thereby, the protective film is not unnecessarily peeled off from the surface of the light transmitting cover during the assembly process of the optical pickup,
The translucent cover is reliably protected during the assembly process to prevent fouling.

In the present invention, the protective film may further include an adhesive layer provided on a surface of the light-transmitting cover other than a surface corresponding to an optical path of the optical composite element, and the light-transmitting cover may be provided with an adhesive layer. It is adhered so as to be able to be peeled away so as to cover the surface of the light transmitting cover. Accordingly, since the adhesive layer of the protective film is not adhered to the surface corresponding to the optical path of the light-transmitting cover, there is no possibility of contamination, and deterioration of the optical characteristics of the optical composite element is almost completely prevented.

Further, in the present invention, the protective film is provided with a holding portion. Accordingly, the protective film can be easily removed from the light-transmitting cover in the final step of assembling the optical pickup.

[0021]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described with reference to FIGS.

In this embodiment, a protective film is attached to the optical pickup according to the present invention on a light-transmitting cover of a so-called laser coupler element, which is an optical composite element composed of a light receiving element, a microprism means, and a light emitting element used in an optical system. And
The protective film is configured to be peeled off from the light-transmitting cover in the final step of assembling the optical pickup.

FIG. 3 shows an example of an optical pickup as a whole. In this optical pickup 1, an objective lens 3 is provided on the upper surface side of a slide base 2 by a two-axis actuator (not shown) in the same manner as a known one. The optical unit 4 is supported so as to be movable in a direction (a tracking direction) orthogonal to a direction (a focus direction) and an optical axis, and an optical unit 4 is disposed on a lower surface side.

A pair of guide support holes 5, 5 through which a guide shaft S of a pickup feed mechanism (not shown) is inserted are provided on the lower surface of one side of the slide base 2 so as to face each other in the axial direction. A rack gear 7 having a backlash compensation mechanism 6 is provided on one end face side with guide support holes 5, 5.
, Ie, parallel to the guide shaft S.

On the upper surface of the slide base 2,
An actuator cover 8 that covers a biaxial actuator that supports the objective lens 3 is fitted, and a window 9 through which the objective lens 3 faces is formed on the upper surface of the actuator cover 8.

Optical pickup 1 constructed as described above
The housing 4a of the optical unit 4 has an optical composite element 10 composed of a light receiving element, a microprism means, and a light emitting element, a so-called laser coupler element, as light emitting and light receiving means.

The optical composite element 10, a so-called laser coupler element, will be described with reference to FIGS. 1 and 2. Since the element body is constructed in the same manner as the optical composite element shown in FIG. Are denoted by the same reference numerals, and detailed description is omitted.

The optical composite device 10 of this embodiment is the same as that of FIG.
The element body 21 configured in the same manner as the element body 21 of the optical composite element 20 is stored in a flat package 11 as a package. This flat package 11
The flat package 11 is formed on the base substrate 22 of the element main body 21 with the upper and lower surfaces formed in an open frame shape.
The element body 21 is surrounded and fixed.
The optical composite element 10, a so-called laser coupler element, is formed by fitting and fixing a light-transmitting cover 12 made of transparent glass or the like to a.

In FIG. 1, the element body 21 of the optical composite element 10 has the same structure as that shown in FIG.

The optical composite element 10 constructed as described above is attached to the housing 4a of the optical unit 4 of the optical pickup 1 shown in FIG.

The laser light emitted from the semiconductor laser LD of the element body 21 of the optical composite device 10, that is, the emitted light is reflected upward by the microprism element 28 in the same manner as shown in FIG. The objective lens passes through the light-transmitting cover 12 and is incident on the objective lens. The objective lens transmits the incident light speed on the signal recording surface of the optical disk by condensing the light through the disk substrate, and is reflected by the signal recording surface. The reflected light flux of the light flux passes through the light transmitting cover 12 to the element main body 21 through the objective lens and returns, and the returned light flux passes through the semi-transmissive film of the microprism element 28 and enters one of the divided photodiodes.

At this split photodiode, the return light beam is detected to be received, and at the same time, a part of the return light beam is reflected by the micro prism element 28 and enters the other split photodiode, where the light reception is detected and the signal is detected. An information signal recorded on the recording surface is read.

According to the present invention, in the optical pickup 1 for reading out the information signal recorded on the signal recording surface of the optical disk, deterioration of the optical characteristics caused during the assembling process is prevented, and light emission is performed. , So that light can be stably received.

That is, a transparent glass plate or the like fitted and fixed to the opening 11a of the flat package 11, which is a package of a so-called laser coupler element, as a means for detecting light emission and light reception of the optical pickup 1 is used. A light-transmitting protective film 13 is adhered to the surface of the light-transmitting cover 12 to be formed, and in this state, the optical composite element 10 is connected to the housing 4 of the optical unit 4 of the optical pickup 1.
The optical pickup 1 is assembled by attaching the optical pickup 1 to a. Then, in the final step of assembling the optical pickup 1, the protective film 13 is peeled off from the light-transmitting cover 12 of the optical composite element 10.

As described above, during the assembling process of the optical pickup 1, the surface of the light-transmitting cover 12 of the optical composite element 10 is covered with the protective film 13 so that the flexible wiring board can be formed in the assembling process. Solder flux at the time of soldering, adhesive cleaning such as an ultraviolet-curing adhesive used for fixing, connecting, and connecting each member may be scattered to the light transmitting cover 12 side, or alcohol may be applied to the light transmitting cover 12 side. Even if whitening of the instant adhesive with respect to the cleaning mark occurs, the surface of the light-transmitting cover 12 is protected by the protective cover 13, thereby preventing contamination.

Therefore, in the final assembly step of the optical pickup 1, the protective film 13 is peeled off from the surface of the light-transmitting cover 12 so that the light-transmitting cover 12 is exposed in a normal state, and the optical composite in the assembly step is removed. Element 1
0 optical characteristic deterioration is prevented.

As described above, the protective film 13 to be adhered to the light-transmitting cover 12 of the optical composite element 10 is formed of a transparent film such as a polyethylene film, and the protective film 13 is brought into direct contact with the surface of the light-transmitting cover 12. Can be stuck.

As shown in FIG. 4, the protective film 13 is provided on the back of the film
By forming an adhesive layer 15 that does not cause peeling from the light-transmitting cover 12 and sticking the adhesive layer 15 to the surface of the light-transmitting cover 12 via the adhesive layer 15, unnecessary peeling from the light-transmitting cover 12 is prevented, and The light cover 12 can be reliably protected.

As shown in FIGS. 1 and 5, the protective film 13 has an adhesive layer 15 which does not peel off from the film material 14 on the back surface, as shown in FIGS. That is, it is formed on the surface of the light transmitting cover 12 except for the light path area surface 13 a corresponding to the light path from the element body 21, and is adhered to the surface of the light transmitting cover 12 via the adhesive layer 15. As described above, the protective film 13 has the light path area surface 1 corresponding to the light path area 12a of the light transmitting cover 12.
Since the adhesive layer 15 is not formed on the optical pickup 3a, the optical path from the element main body 21 is formed in a normal state even when the protective sheet 13 is adhered to the transparent cover 12, and the objective optical path is formed during the assembly process of the optical pickup 1. The mutual position correction and the like of the lens 3 and the optical composite element 10 can be accurately performed.

Further, the protective film 33 is provided with a tongue tongue 13b, 13c as a holding portion at a side edge thereof, so that it can be easily held when peeled off from the light transmitting cover 12 in the final assembly step. Thus, the peeling operation can be performed quickly.

The embodiment of the present invention has been described above.
The present invention is not limited to this embodiment, and can be variously modified without departing from the spirit of the present invention.

For example, in the above-described illustrated example, the optical pickup is provided with an optical composite element, a so-called laser coupler element, in the direction of the optical axis of the objective lens, and an optical path is formed linearly from the element body to the objective lens. The configuration may be such that the laser coupler element is arranged at a position off the optical axis of the objective lens and the optical path is bent using a mirror. Further, a configuration may be adopted in which an objective lens is held, a laser coupler element is arranged on a lens bobbin driven by a biaxial actuator, side by side with the objective lens, and an optical path to the objective lens is bent using two return mirrors.

The optical composite device 10 in the illustrated example
The light-transmitting cover 12 protrudes from the upper surface of the flat package 11 and is fitted and fixed. In an actual product, the light-transmitting cover 12 is fitted and fixed on the same surface as the upper surface of the flat package 11. Will be.

The present invention can be applied to various optical pickups having a light emitting section and a light receiving section.

[0045]

As described above, the optical pickup according to the present invention is an optical pickup using an optical composite element composed of a light receiving element, a microprism means, and a light emitting element in the optical system, in which the element body of the optical composite element is housed. A protective film is releasably attached to the surface of the light-transmitting cover that covers the light-transmitting opening of the package to be removed, and is peeled and removed in the final step of assembling the optical pickup. Of the optical composite element is prevented from deteriorating, and light emission and light reception on the objective lens side can be performed more reliably, and reliability is improved.

The protective film is adhered to the light-transmitting cover via an adhesive layer, so that the light-transmitting cover is securely protected without being unnecessarily peeled off during the assembling process. By forming the layer on the surface of the light-transmitting cover except for the light-path area, there is no possibility that the light-path area of the light-transmitting cover is contaminated by the adhesive, and the protective film is formed of a transparent material to transmit light. Light emission and light reception of the optical composite element can be performed with the protective film adhered to the cover, and adjustment of light emission and the like during the assembly process can be performed. Further, by forming the holding portion in the protective film, the work of peeling the protective film from the light-transmitting cover can be easily performed.

[Brief description of the drawings]

FIG. 1 is a sectional view of an optical composite element as an example of an optical pickup according to the present invention.

FIG. 2 is a perspective view of the optical composite device shown in FIG. 1 in a state where a protective film is peeled off.

FIG. 3 is a perspective view of an example of an optical pickup according to the present invention.

FIG. 4 is a cross-sectional view of an example of a protective film attached to the optical composite device shown in FIG.

FIG. 5 is a cross-sectional view of another example of the protective film attached to the optical composite device shown in FIG.

FIG. 6 is an explanatory diagram schematically showing a configuration of a prior art optical pickup.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 optical pickup, 10 optical composite element, 11 flat package, 12 translucent cover, 13 protective film, 13 a translucent area, 13 b, 13 c sandwiching tongue piece, 15 adhesive layer, 21 element body, 22 base substrate, 24 photo Diode IC, 26 PD board, 3
8 Micro prism element, LD semiconductor laser

Claims (4)

[Claims] 1. An optical pickup using an optical composite element comprising a light receiving element, a microprism means, and a light emitting element in an optical system, wherein a light transmitting opening of a package in which an element body of the optical composite element is stored is provided. An optical pickup characterized in that a protective film is releasably attached to a surface of a light-transmitting cover to be covered, and is detached in a final step of assembling the optical pickup. 2. The protective film is provided with an adhesive layer,
2. The light-transmitting cover according to claim 1, wherein the light-transmitting cover is detachably adhered to a surface of the light-transmitting cover to cover the surface of the light-transmitting cover.
An optical pickup according to item 1. 3. The protective film is formed of a transparent material, an adhesive layer is provided on a surface of the light transmitting cover except for a surface corresponding to an optical path of the optical composite element, and the surface of the light transmitting cover is provided with an adhesive layer. 2. The light-transmitting cover according to claim 1, wherein the light-transmitting cover covers the surface of the light-transmitting cover.
An optical pickup according to item 1. 4. The optical pickup according to claim 1, wherein a sandwiching portion is formed on the protective film.