JP2728209B2 - Flexible board fixing device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device provided in an information recording / reproducing device for recording, reproducing and / or erasing information on a disk-shaped recording medium with a laser beam or the like, and in particular, is movable. The present invention relates to a flexible substrate fixing device provided in a device in which various optical head units are connected by a flexible substrate.

[Conventional technology]

Conventionally, flexible substrates take advantage of the flexibility,
Many devices are used for disposing them in a limited narrow space, for electrical connection with movable parts, and the like.

In particular, in a portion of the flexible substrate which is repeatedly bent, a sharp component is prevented by lining another component having a thickness of about 100 μm to protect the copper foil pattern inside the flexible substrate.

[Problems to be solved by the invention]

However, the backing for improving the durability of the flexible substrate subjected to repeated bending increases the cost of the flexible substrate and still fails to provide sufficient durability. The flexibility of the basic flexible substrate is durable against bending like 50 in FIG. 5, but extremely durable for usage like 52 in FIG. In the worst case, the copper foil pattern is broken after several thousand to tens of thousands of times. In order to improve the durability of the flexible substrate, it is good to increase the bending R from the fixing portion to the bending portion as shown in FIG. 5, but if a sufficient space is taken and the bending length of the flexible substrate is not allowed to have a margin, the flexible substrate becomes flexible. The reaction force of the substrate and the backing material hinder the movement of the movable part, and it has the disadvantage that the device itself becomes large.Therefore, wiring in a full-height or half-height space to be built into a personal computer or the like Then, at present, it cannot be realized. The configuration of FIG. 6 has good space efficiency and can minimize the reaction force of the flexible substrate. Occurs, it is difficult to maintain the initial characteristics, and there is a problem of durability, a change in access time, and in the worst case, the movable part does not operate to a predetermined position.

〔Purpose〕

The present invention has been made in view of the above-described problems of the related art, and its object is to significantly improve the durability of the bent portion of the flexible substrate in a limited space, and to reduce the reaction force of the flexible substrate. An object of the present invention is to provide a flexible substrate fixing device capable of minimizing a change with time while minimizing the change.

[Means for solving the problem]

According to the present invention, according to the present invention, one end of a flexible substrate is electrically connected to an optical head unit movable relative to an apparatus main body of an information recording / reproducing apparatus, and the other end is electrically connected to the apparatus main body. In the flexible substrate fixing device which is connected to the optical substrate, the connecting portion of the optical head unit to the flexible substrate, in a range of 30 degrees to 90 degrees, at an angle, bent at an angle, a fixing member for fixing. The fixing member is provided so as to function as a shield plate for protecting an electric signal passing through the inside of the flexible substrate from external noise.

〔Example〕

Hereinafter, embodiments according to the present invention will be described specifically and in detail with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of a flexible substrate fixing device according to the present invention, and FIG. 2 is an exploded perspective view of the flexible substrate fixing device for explaining the present invention.

In the figure, reference numeral 1 denotes an actuator unit that moves and adjusts all or a part of an optical system for recording and / or reproducing and / or erasing information on an information recording medium in a tracking direction and a focus direction. Reference numeral 2 denotes a semiconductor laser unit that generates a laser beam. Reference numeral 3 denotes a linear sensor that detects the position of the entire optical head unit 7 in the tracking direction by a linear encoder (not shown).

Reference numeral 4 denotes a flexible substrate for transmitting a power signal and the like.
Reference numeral 5 denotes a flexible board fixing member which also serves as a shield plate of the sensor 8 shown in FIG. Reference numeral 6 denotes a flexible board fixing member which also serves as a shield plate of a transmission line for guiding the sensor 8 and other signals to an amplifier circuit (not shown). The flexible substrate fixing member 6 is screwed and fixed together with the flexible substrate fixing member 5 with the flexible substrate 4 interposed therebetween. Further, as shown in FIG. In the case of the present embodiment), it is fixed so as to be bent.

7 is the actuator unit 1, the semiconductor laser unit 2, the linear sensor 3, the flexible substrate 4,
This is an optical head unit on which flexible substrate fixing members 5 and 6 are mounted so as to be movable on a rail (not shown) in the direction of arrow X (that is, the track direction).

FIG. 2 is an exploded perspective view of the flexible substrate fixing members 5 and 6 as described above.

As illustrated, the flexible substrate fixing member 5 is screwed to the optical head unit 7. The optical head unit 7 is provided with a sensor 8 for reading a signal recorded on an information recording medium. The sensor 8 is shielded by the flexible substrate fixing member 5. At the end of the flexible substrate fixing member 5 opposite to the side to which the optical head unit 7 is connected, the flexible substrate fixing member 6 is fixed by screws with the flexible substrate 4 interposed therebetween. At this time, the positioning of each member is performed by the flexible substrate 4.
This is performed by passing screws through the positioning portions 4a and 4b.
The flexible substrate fixing member 6 has a function of shielding a portion of the flexible substrate 4 that transmits a weak signal.

FIG. 3 is a side view showing a fixing range of the flexible board bent portion on a plane including the moving direction of the optical head unit 7 and the bending direction of the flexible board 4.

As shown in the drawing, the bending portion of the flexible substrate 4 is in a range of 30 ° to 90 ° in the bending direction with respect to the moving direction of the optical head unit 7 (the direction of the arrow shown in the drawing) (in the present embodiment, about 30 ° to 90 °).
60 °), the bending angle of the flexible printed circuit 4 is more bent than that of the conventional structure of FIG.
Can be increased, and the bending angle of the bent portion can be reduced to about half or less, and the durability of the flexible substrate can be remarkably improved.

Further, as shown in FIG. 5, the space efficiency can be arranged with a sufficient margin even in a space where durability is sacrificed, and the improvement of the durability by fixing the flexible substrate as described above. Since the backing of the bent portion is not required, the cost of the flexible substrate can be reduced, and the reduction of the reaction force of the flexible substrate and the change in the reaction force of the flexible substrate over time can be simultaneously solved.

In the above embodiment, the fixing of the flexible substrate by screwing has been described. However, the present invention is not limited to this, and the fixing method can be fixed with a push nut or a leaf spring.

6 is an exploded perspective view of a flexible substrate fixing member using a push nut, and FIGS. 8 and 9 are exploded perspective views of a flexible substrate fixing member using different leaf springs. It is a perspective view.

Note that the flexible substrate fixing member can be constituted by a component that does not significantly affect the weight, such as a molded component.

〔The invention's effect〕

As described above in detail and specifically, the influence of external noise can be reduced by positioning and fixing the flexible substrate with the shield plate that protects a weak signal from external noise. Further, according to the present invention, it is possible to eliminate the backing for improving the durability of the flexible substrate without increasing the weight of the optical head unit which requires light load operation, and to reduce the reaction force of the flexible substrate. In addition to eliminating the change of reaction force with time, even if the cost of the flexible substrate is reduced, the durability is not reduced, the basic performance is maintained and improved, and a half-height package is realized, which enables further miniaturization. be able to.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a flexible substrate fixing device according to the present invention, FIG. 2 is an exploded perspective view of a flexible substrate fixing member for explaining the present invention, and FIG. 3 is a moving direction of an optical head unit. 4 and 5 are side views showing a fixed range of a flexible board bent portion on a plane including a bending direction of the flexible board, and FIGS. 4 and 5 are side views showing an installation state of a conventional flexible board. 8 and 9 are exploded perspective views of a flexible substrate fixing member showing another embodiment of the present invention, and FIG. 10 is a perspective view showing a conventional optical head unit. 1: Actuator unit, 2: Semiconductor laser unit,
3: Linear sensor, 4: Flexible board, 5 and 6: Flexible board fixing member, 7: Optical head unit.

Claims (1)

(57) [Claims] 1. An optical head unit movable relative to a device main body of an information recording / reproducing device, one end of a flexible substrate is electrically connected and the other end is electrically connected to the device main body. In a flexible substrate fixing device, a connection member of the optical head unit to the flexible substrate, a fixing member for bending and fixing the flexible substrate at an angle within a range of 30 degrees to 90 degrees, The flexible substrate fixing device, wherein the fixing member is configured to function as a shield plate for protecting an electric signal passing through the inside of the flexible substrate from external noise.