JPH0668513A - Optical pickup - Google Patents

Abstract

PURPOSE:To securely hold an objective lens by providing a groove enclosing an objective lens to the lens holding member and applying an adhesive thereto. CONSTITUTION:This optical pickup holds the objective lens 10 with the objective lens holding member 20. The member 20 is constituted by forming a rib 20a at its top end face so as to enclose the outer periphery of the lens 10 and forming a wall surface so as to enclose the ring 10. The groove opening on the upper side is formed by the outer periphery and wall surface of the lens 10 and the adhesive is applied to this groove. Since the groove opens to the upper side, the outflow of the adhesive is prevented even if a large amt. of the adhesive is applied. The lens 10 is thus securely held. The rib 20a is formed along the outside shape of the member 20, by which the coated amt. of the adhesive is increased. Since the member 20 is integrally formed, the constitution over the entire surface is simplified. The secure holding of the lens 10 is thus possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup, and more particularly to an optical pickup in which an objective lens for focusing a light beam on an optical recording medium is firmly held.

[0002]

2. Description of the Related Art Conventionally, in an optical pickup such as a magneto-optical disk device, a light beam emitted from a laser diode can be focused on an optical recording medium to record and reproduce desired information.

As shown in FIG. 3, in this type of optical pickup 1, a light beam L1 emitted from a laser diode 2 is converted into parallel rays by an objective lens 4 and then reflected by a polarization beam splitter 6 to be reflected by a mirror 8. The optical path is bent and made incident on the objective lens 10.

The objective lens 10 focuses the light beam L1 on the information recording surface of the magneto-optical disk 12,
In this optical pickup 1, at this time, the light beam L
By applying a predetermined modulation magnetic field to the irradiation position at 1,
The desired recording information is thermomagnetically recorded.

On the other hand, at the time of reproduction, in the optical pickup 1, the light amount is reduced and the light beam L1 is emitted, and the reflected light beam L2 of the light beam L1 reflected by the magneto-optical disk 12 is condensed by the objective lens 10. To do.

As a result, the objective lens 10 passes the reflected light beam L2 through the mirror 8 to the polarization beam splitter 6
To pass through the polarization beam splitter 6 and lead to the photodiode 14.

Accordingly, in the optical pickup 1,
Recorded information can be reproduced by detecting a change in the plane of polarization of the reflected light beam L2.

At the time of this recording / reproducing, in the optical pickup 1, the objective lens 10 is moved vertically and horizontally to perform focus control and tracking control, so that desired information can be surely recorded / reproduced. There is.

Therefore, in the conventional optical pickup 1, the objective lens 10 is held by a predetermined objective lens holding member 16, and the objective lens holding member 16 can be moved vertically and horizontally by a predetermined actuator.

Therefore, in the optical pickup 1, a rib 10a is formed coaxially with the objective lens 10 on one surface of the objective lens 10, and the objective lens 10 is guided by the rib 10a and the outer periphery of the objective lens 10. By inserting the objective lens 10 into the through hole of the lens holding member 16, the optical axis of the objective lens 10 is substantially orthogonal to the magneto-optical disk 12, and the other surface of the objective lens 10 projects from the upper end surface 16b of the objective lens holding member 16. The objective lens 10 is positioned.

In this state, in the optical pickup 1,
The objective lens holding member 16 is provided along the outer periphery of the objective lens 10.
An adhesive is applied to the upper end surface 16b of the objective lens 10 to fix the objective lens 10 to the objective lens holding member 16.

Accordingly, in the optical pickup 1,
Even if the objective lens holding member 16 is moved vertically and horizontally, the objective lens 10 is held so as not to fall off, and focus control and tracking control can be reliably performed.

The magneto-optical disk 12 of the objective lens 10
On the side, a rib 10b is formed coaxially with the objective lens 10 so that the adhesive applied along the outer periphery does not enter the lens surface of the objective lens 10.

[0014]

By the way, when the objective lens 10 is held by using the adhesive as described above, the objective lens 10 can be firmly held by increasing the coating amount of the adhesive.

That is, the objective lens 10 and the objective lens holding member 16 have different coefficients of thermal expansion, and they are entirely movable, and in some cases, shock is applied.

However, in the conventional optical pickup 1, if the amount of adhesive applied is increased, the objective lens holding member 1
There is a problem that the coating amount cannot be increased after all because the adhesive flows out from No. 6.

One method for solving this problem is to increase the upper end surface of the objective lens holding member 16 to prevent the adhesive from flowing out, but in this case, there is a problem that the objective lens holding member 16 becomes large. , Not practical.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an optical pickup capable of firmly holding an objective lens by increasing the amount of adhesive applied to fix the objective lens. And

[0019]

According to the present invention, the above object is to record and reproduce information on and from an optical recording medium by condensing a light beam emitted from a light source onto the optical recording medium by an objective lens. In the optical pickup for performing the above, the objective lens is fixed by being inserted into a through hole formed in the lens holding member, and is held together with the objective lens holding member so as to be movable vertically and horizontally, and the objective lens holding A wall surface is formed on the member so as to surround the through hole, and thus a groove sandwiched between the wall surface and a wall surface on the outer periphery of the objective lens is provided. The objective lens is formed by applying an adhesive agent to the groove. This is achieved by an optical pickup configured to fix.

The objective lens has a rib surrounding the lens surface on the opening side of the groove, and the wall surface of the objective lens holding member surrounding the through hole surrounds the lens surface formed on the lens. It can be formed lower than the ribs.

Further, the wall surface of the objective lens holding member can be formed by a rib rising from the objective lens holding member.

Preferably, the rib rising from the objective lens holding member is formed integrally with the objective lens holding member.

[0023]

According to the structure of the optical pickup described above, the adhesive can be prevented from flowing out by the groove surrounding the objective lens.
A large amount of adhesive can be applied.

Further, by making the wall surface lower than the ribs formed on the lens surface, it is possible to prevent the adhesive from flowing out to the lens surface side even if the amount of adhesive applied is too large.

Further, it is possible to form the groove easily by forming the wall surface with a rib. Further, the rib can be formed integrally with the objective lens holding member to simplify the configuration.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below in detail with reference to the accompanying drawings. The examples described below are
Since it is a preferred specific example of the present invention, various technically preferable limitations are attached, but the scope of the present invention is, unless otherwise stated to limit the present invention, in the following description.
These aspects are not limited.

FIG. 1 is a schematic sectional view showing an objective lens holding portion of an optical pickup according to the present invention, corresponding to FIG.

In the figure, in the optical pickup, instead of the objective lens holding member 16, the objective lens holding member 20 holds the objective lens 10.

The objective lens holding member 20 has the same structure as the objective lens holding member 16 except that a rib 20a is formed on the upper end surface so as to surround the outer periphery of the objective lens 10, and the objective lens holding member 20 is formed by the rib 20a. A wall surface is formed so as to surround 10.

As a result, in the optical pickup, a groove opening upward is formed between this wall surface and the outer periphery of the objective lens 10, and an adhesive is applied to this groove.

Therefore, the adhesive applied to the groove can be prevented from flowing out even when a large amount of the adhesive is applied as compared with the conventional one, and thus, in the optical pickup, the adhesive application amount is increased and the objective is firmly fixed. The lens 10 can be held.

Further, in this embodiment, the objective lens holding member 20 is formed so that the rib 20a is lower than the rib 10b formed on the lens surface of the objective lens 10, so that even if the amount of adhesive applied is too large, The adhesive does not flow out to the lens surface side.

Therefore, in this optical pickup, it is possible to assemble it safely, and the yield of the optical pickup can be improved.

Further, as shown in FIG. 2, the rib 20a is
It is formed along the outer shape of the objective lens holding member 20, whereby the application amount of the adhesive is increased. At this time, by being formed integrally with the objective lens holding member 20,
The whole structure can be simplified.

[0035]

As described above, according to the optical pickup of the present invention, the application amount of the adhesive for fixing the objective lens can be increased to firmly hold the objective lens.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an embodiment of an optical pickup of the present invention.

FIG. 2 is a plan view showing the objective lens holding member.

FIG. 3 is a schematic diagram showing a conventional optical pickup.

[Explanation of symbols]

 1 Optical Pickup 2 Laser Diode 10 Objective Lens 16, 20 Objective Lens Holding Member 18 Adhesive

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[Procedure amendment]

[Submission date] September 30, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

2. The optical pickup according to claim 2, wherein a wall surface of the objective lens holding member is formed by a rib rising from the objective lens holding member.

Wherein ribs rising from the objective lens holding member, characterized in that it is formed integrally with the objective lens holding member, the optical pickup according to claim 3.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be amended] Detailed explanation of the invention

[Correction method] Change

[Correction content]

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup, and more particularly to an optical pickup in which an objective lens for focusing a light beam on an optical recording medium is firmly held.

[0002]

2. Description of the Related Art An example of a conventional optical disk device
For example, in the optical pickup of the magneto-optical disk device ,
A light beam emitted from a laser diode is focused on an optical recording medium to record / reproduce desired information.

As shown in FIG. 3, in the optical pickup 1 of this type, the light beam L1 emitted from the laser diode 2 is split into three beams by the grating 4 ,
The light is reflected by the polarization beam splitter 6 and guided to the mirror 8, where the optical path is bent and made incident on the objective lens 10.

[0004] objective lens 10, by condensing the light beam L1 on the information recording surface of the optical disk 12, in this optical pickup 1, to record the recording information of Nozomu Tokoro.

[0005] During reproduction contrast, in the optical pickup 1 irradiates the light beam L1 by reducing the amount of light, the reflected light beam of the light beam L1 reflected by the optical de <br/> disc 12 L2
Is condensed by the objective lens 10.

As a result, the objective lens 10 passes the reflected light beam L2 through the mirror 8 to the polarization beam splitter 6
To pass through the polarization beam splitter 6 and lead to the photodiode 14.

Accordingly, in the optical pickup 1,
Recorded information can be reproduced by detecting a change in the plane of polarization of the reflected light beam L2.

At the time of this recording / reproducing, in the optical pickup 1, the objective lens 10 is moved vertically and horizontally to perform focus control and tracking control, so that desired information can be surely recorded / reproduced. There is.

Therefore, in the conventional optical pickup 1, the objective lens 10 is held by a predetermined objective lens holding member 16, and the objective lens holding member 16 can be moved vertically and horizontally by a predetermined actuator.

Therefore, in the optical pickup 1, a rib 10a is formed coaxially with the objective lens 10 on one surface of the objective lens 10, and the objective lens 10 is guided by the rib 10a and the outer periphery of the objective lens 10. by inserting into the through hole of the lens holding member 16, so that the optical axis of the objective lens 10 is substantially perpendicular to the optical disk 12, and the other surface of the objective lens 10 from the upper end surface 16b of the objective lens holding member 16 protrudes The objective lens 10 is positioned.

In this state, in the optical pickup 1,
The objective lens holding member 16 is provided along the outer periphery of the objective lens 10.
An adhesive is applied to the upper end surface 16b of the objective lens 10 to fix the objective lens 10 to the objective lens holding member 16.

Accordingly, in the optical pickup 1,
Even if the objective lens holding member 16 is moved vertically and horizontally, the objective lens 10 is held so as not to fall off, and focus control and tracking control can be reliably performed.

[0013] Note that the optical disk 12 side of the objective lens 10, a rib 10 c is formed on the objective lens 10 coaxially
There is. And, so as not to ride on the upper surface of this rib 10c
The adhesive is applied every time and along its outer circumference.

[0014]

By the way, when the objective lens 10 is held by using the adhesive as described above, the objective lens 10 can be firmly held by increasing the coating amount of the adhesive.

That is, the objective lens 10 and the objective lens holding member 16 have different coefficients of thermal expansion, and they are entirely movable, and in some cases, shock is applied.

However, in the conventional optical pickup 1, if the amount of adhesive applied is increased, the objective lens holding member 1
There is a problem that the coating amount cannot be increased after all because the adhesive flows out from No. 6.

One method for solving this problem is to increase the upper end surface of the objective lens holding member 16 to prevent the adhesive from flowing out, but in this case, there is a problem that the objective lens holding member 16 becomes large. , Not practical.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an optical pickup capable of firmly holding an objective lens by increasing the amount of adhesive applied to fix the objective lens. And

[0019]

According to the present invention, the above object is to record and reproduce information on and from an optical recording medium by condensing a light beam emitted from a light source onto the optical recording medium by an objective lens. In the optical pickup for performing the above, the objective lens is fixed by being inserted into a through hole formed in the lens holding member, and is held together with the objective lens holding member so as to be movable vertically and horizontally, and the objective lens holding A wall surface is formed on the member so as to surround the through hole, and thus a groove sandwiched between the wall surface and a wall surface on the outer periphery of the objective lens is provided. The objective lens is formed by applying an adhesive agent to the groove. This is achieved by an optical pickup configured to fix.

[002 0] Moreover, the wall surface of the objective lens holding member can be formed by a rib rising from the objective lens holding member.

[002 1] Preferably, the ribs rising from the objective lens holding member is formed integrally with the objective lens holding member.

002 2

According to the structure of the optical pickup described above, the adhesive can be prevented from flowing out by the groove surrounding the objective lens.
A large amount of adhesive can be applied.

[002 3] also form easily grooves forming said wall with ribs. Further, the rib can be formed integrally with the objective lens holding member to simplify the configuration.

[002 4]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below in detail with reference to the accompanying drawings. The examples described below are
Since it is a preferred specific example of the present invention, various technically preferable limitations are attached, but the scope of the present invention is, unless otherwise stated to limit the present invention, in the following description.
These aspects are not limited.

[002 5] Figure 1 is a schematic sectional view showing an objective lens holder of an optical pickup according to the present invention and corresponds to FIG. 3.

In [002 6] FIG, optical pickup, instead of the objective lens holding member 16 holds the objective lens 10 by the objective lens holding member 20.

[002 7] The objective lens holding member 20, so as to surround the outer periphery of the objective lens 10, except that the formation of the ribs 20a on the upper end face, the same configuration as the objective lens holding member 16, the objective in this rib 20a A wall surface is formed so as to surround the lens 10.

[00 28] In this way the optical pickup, the wall surfaces and a groove that opens upward in the outer periphery of the objective lens 10 is formed, so as to apply the adhesive to the groove.

In [00 29] Accordingly adhesive applied to the groove, even when the large amount of coating as compared with the prior art, can be prevented from flowing out, thereby the optical pickup, strongly increasing the coating amount of the adhesive The objective lens 10 can be held.

[003 0] As further shown in FIG. 2, the ribs 20a is,
It is formed along the outer shape of the objective lens holding member 20, whereby the application amount of the adhesive is increased. At this time, by being formed integrally with the objective lens holding member 20,
The whole structure can be simplified.

003 1

As described above, according to the optical pickup of the present invention, the application amount of the adhesive for fixing the objective lens can be increased to firmly hold the objective lens.

[Procedure 3]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

[Procedure amendment 4]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 3

[Correction method] Change

[Correction content]

[Figure 3]

Claims (4)

[Claims] 1. An optical pickup that records and reproduces information on an optical recording medium by condensing a light beam emitted from a light source onto the optical recording medium by the objective lens, wherein the objective lens is a lens holding member. The objective lens holding member is fixed by being inserted into the through hole formed in the above, and is held so as to be vertically and horizontally movable together with the objective lens holding member, and a wall surface is formed in the objective lens holding member so as to surround the through hole. As a result, a groove sandwiched between this wall surface and the outer peripheral wall surface of the objective lens is provided, and an adhesive is applied to the groove to fix the objective lens. pick up. 2. The objective lens has a rib surrounding a lens surface on a side where the groove is opened, and the wall surface of the objective lens holding member surrounding the through hole surrounds a lens surface formed on the lens. The optical pickup according to claim 1, wherein the optical pickup is formed lower than the rib. 3. The optical pickup according to claim 2, wherein a wall surface of the objective lens holding member is formed by a rib rising from the objective lens holding member. 4. The optical pickup according to claim 3, wherein the rib rising from the objective lens holding member is formed integrally with the objective lens holding member.