JP2520681Y2 - Optical pickup device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an optical pickup device that can be used in an optical disk device, a magneto-optical disk device, or the like.

(Prior Art) A conventional optical pickup device used in an optical disk device, a magneto-optical disk device, or the like positions an optical element such as a semiconductor laser, a lens, or a prism on a frame body having an integrally molded structure from one open surface side thereof. Then, it was fixed and covered with a cover covering the whole.

(Problems to be solved by the invention) According to the conventional optical pickup device, since the cover is placed on the open surface side of the frame body in which the optical element is positioned and fixed, the frame body and the cover are covered. There is a problem in that a gap is generated between them and dust and dirt easily enter, and the transmission performance and reflection performance of the optical element are significantly deteriorated. Further, the cover is not strong enough and does not provide sufficient protection against distortion and displacement of the optical element due to external force. further,
Since the optical element is almost exposed to the outside air, there is a problem that the optical element is easily deteriorated due to environmental changes or dew condensation easily occurs.

The present invention has been made in order to solve the above-mentioned conventional problems. When the optical element is positioned and fixed, the optical element is hermetically sealed so that the optical element is distorted or displaced by an external force. It is an object of the present invention to provide an optical pickup device that is free from dust and that is unlikely to enter dust or dust.

(Means for Solving Problems) In the present invention, an open groove is formed on one surface side, and at least a semiconductor laser, an optical element including a beam splitter and a light receiving element are fixed and supported in the open groove. The base plate has a frame and a substrate fixed to the open face of the support frame so as to cover the open face of the open groove, and the bearing portion that engages with a guide shaft that serves as a guide when the substrate moves. It is characterized in that it is bent and formed at the end of the.

(Operation) The support frame which fixes and supports the optical element is hermetically sealed by the open surface of the open groove being covered and fixed by the substrate. In addition, a bearing portion that engages with the guide shaft is bent and formed at the end portion of the substrate, and the rigidity of the entire substrate is increased.

(Example) Hereinafter, an example of an optical pickup device according to the present invention will be described with reference to the drawings.

In FIGS. 1 to 5, reference numeral 30 is a support frame for supporting the optical element, and the bottom surface side, which is one surface side of the support frame 30, has open grooves 34, 38, 40 and open grooves from the bottom surface side.
The open surface is formed by forming 36. (Fifth
See figure). The open grooves 34, 38, 40 communicate with each other through the open groove 36 in the central portion, the open grooves 34, 38 form an angle of 90 degrees with each other, and the open grooves 34, 40 also have an angle of 90 degrees with each other. It makes an angle. Open groove from one side of support frame 30
A hole 32 communicating with 34 is formed, and a semiconductor laser is formed in the hole 32.
10 is inlaid. The diffraction grating 16 held by the holder 18 is fitted into the open groove 34. A beam splitter 12 for splitting the laser light from the semiconductor laser 10 is obliquely fixed to the open groove 36. An inclined surface 42 that communicates with the open groove 38 is formed at the outer end of the support frame 30, and the beam splitter 12 is formed on the inclined surface 42.
A mirror that guides the laser light split by
26 is stuck. A holder 22 holding a sensor lens 20 which is a concave lens is fitted in the open groove 40.
A light receiving element 14 for receiving the laser beam that has passed through the lens 20 is fixed to the outer surface of the support frame 30 by a holder 24.

In this way, the semiconductor laser 10 and the beam splitter 12
The optical element including the light receiving element 14 and the light receiving element 14 are fixed and supported in the open grooves of the support frame 30 having one open side. The support frame 30 has its open groove side on the substrate 46 and is fixed to the substrate 46 by screwing. As a result, the support frame 30 has its open surface covered with the substrate 46 and is fixed in a hermetically sealed manner.

A bearing 48 is fixed to the substrate 46 at the side of the mounting portion of the support frame 30.
50 is fitted. An objective lens block 52 is fitted on the upper end of the shaft 50 so as to be movable and rotatable in the axial direction. Objective lens block 52 has an objective lens with axis 50 in between.
54 and a balance weight 56 are fitted, and a pair of focusing coils 58, 58 sandwiching the shaft 50 on a line orthogonal to the line connecting the lens 54 and the balance weight 56.
Is stuck. A set of two tracking coils 60, 60 is fixed to each of these coils 58, 58. The objective lens 54 is located above the mirror 26.

Two pairs of horseshoe-shaped cores 62, 62 are fixed on both sides of the board 46, and one of the pair of magnetic pole pieces of the cores 62, 62 rising upward has a permanent magnet 64, 64 on one magnetic pole piece. Is stuck. One magnetic pole piece of each core 62, 62 advances into the focusing coils 58, 58, and
One side of the coils 58, 58 and the coils 60, 60 are sandwiched by a pair of magnetic pole pieces 62, 62. Therefore, the coil 58,
Focusing control can be performed by moving the objective lens block 52 in the optical axis direction of the objective lens 54 by controlling the energization of 58, and by controlling the energization of the coils 60, 60, the block 52 is moved along with the objective lens 54 to the axis 50. It is possible to perform tracking control by rotating it around. The components including the block 52, the objective lens 54, the coils 58 and 60, the permanent magnets 64 and 64, and the like constitute an actuator for performing focusing and tracking, and a cover 80 is covered on the actuator portion. The cover 80 is formed with a window hole 82 for passing light from the objective lens 54.

A bearing portion 66 that engages with the guide shaft 78 is formed at one end of the substrate 46. Further, a bent portion 47 for screwing the bearing member 68 is formed on the other end of the substrate 46. The bearing member 68 has bearing portions 70, 70 at both ends. The bearings 70, 70 are penetrated by another guide shaft (not shown) parallel to the guide shaft 78. The substrate 46 can be moved by being guided by these guide shafts, whereby the entire optical pickup device is moved in a direction traversing a recording track of a disc (not shown).

Another bearing member 72 can be screwed to the bottom surface of the substrate 46. Bent portions are formed at both ends of the bearing member 72, and bearing portions 74 and 76 are formed at the bent portions, respectively. The bearings 74 and 76 are penetrated by a guide shaft similar to the guide shaft 78. Board 46
Can be guided and moved by these guide shafts,
Therefore, the entire optical pickup device can be moved in the direction traversing the recording track of the disc.

The two bearing members 68, 72 are selectively used. For example, when a thin type is required such as a portable optical disk device, the bearing member 68 is used. The bearing member 72 is used when prevention is required.

A part of the laser beam emitted from the semiconductor laser 10 is bent at a right angle by the beam splitter 12 after passing through the diffraction grating 16, and is further bent at a right angle by the mirror 26, passes through the objective lens 54, and is not shown in the figure. On the recording track. The light reflected by the disk passes through the objective lens 54, is reflected by the mirror 26, passes through the beam splitter 12, passes through the sensor lens 20, and then the light receiving element 14
Is received by. As is well known, a focus signal and a track signal can be obtained from the light receiving element 14 in addition to the information signal recorded on the disc, and the reading signal is also used for focusing control and tracking control.

According to the above-described embodiment, the open groove is formed on one surface side of the support frame 30 of the optical element, the optical elements are intensively attached from the open surface side of the open groove, and the opening of the support frame 30 to which the optical element is attached is opened. Since the surface side is fixed to the substrate 46 and the open surface side is covered with the substrate 46, the opening of the support frame 30 is reduced to form a hermetically sealed state, and dust and dust are prevented from entering the optical element side. You can Also support frame
Since the entire surface is composed of the robust structure with the substrate 30 and the substrate 46, it is possible to reduce deformation and distortion due to external force. In addition, by improving the airtightness, deterioration of optical elements due to changes in environmental conditions and dew condensation due to temperature changes are less likely to occur, and the occurrence of noise and the like can be reduced because stray light from the outside is less affected.

In the illustrated embodiment, the portion of the support frame 30 where the mirror 26 is attached is open, but the other optical element portions are closed by the support frame 30 and the substrate 46, and the above effects are obtained. be able to.

Some optical elements need to be adjusted after being assembled in the support frame. Such a thing may be elastically movably attached via, for example, a leaf spring. Moreover, adjustment may be performed by forming an adjustment hole in the support frame or the substrate. Even when the adjustment hole is formed, this does not impair the above-described effects of the present invention.

(Effects of the Invention) According to the present invention, an open groove is formed on one surface side of a support frame of an optical element, and the optical element is intensively attached from the open surface side of the open groove. Since the open surface side of the open groove is fixed to the substrate and the open surface side is covered with the substrate, the opening of the support frame is reduced to form a hermetically sealed state, preventing dust and dust from entering the optical element side. Can be prevented. In addition, since the bearing portion that engages with the guide shaft is bent and formed at the end portion of the substrate, not only the rigidity of the entire substrate is increased, but also the bearing portion is integrally formed, reducing the number of parts. Leads to. Furthermore, since the entire surface is constituted by the support frame and the substrate to be a robust structure, it is possible to reduce deformation and distortion due to external force. Furthermore, the influence of stray light from the outside is small, and the occurrence of noise and the like can be reduced.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an embodiment of an optical pickup device according to the present invention, FIG. 2 is a plan view of the same embodiment, FIG. 3 is a side sectional view of the same, and FIG. 4 is a line in FIG. A sectional view taken along the line IV-IV and FIG. 5 are bottom views of the support frame in the above embodiment. 10 …… Semiconductor laser, 12 …… Beam splitter, 14 ……
Light receiving element, 30 ... Support frame, 46 ... Substrate.

Claims (1)

(57) [Scope of utility model registration request] 1. An open groove is formed on one surface side, and at least a semiconductor laser and a beam splitter are formed in the open groove.
A support frame to which an optical element including a light receiving element is fixed and supported, and a substrate fixed to the open surface side of the support frame to cover the open surface of the open groove are provided. An optical pickup device, wherein a bearing portion that engages with a guide shaft that serves as a guide is bent and formed at an end portion of the substrate.