JPH0541578Y2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] (Field of industrial application) This invention is a lead wire that electrically connects a plurality of printed wiring boards that are configured to be relatively rotatable via a hinge mechanism. Regarding connection devices.

(Prior art) As shown in FIGS. 4 and 5, as a configuration in which two separated circuit members are electrically connected to each other by lead wires, one of the circuit members rotates or rotates. It may be connected.

FIGS. 4 and 5 show an example of a conventional connection structure using lead wires using a liquid crystal television receiver as an example, in which 1 is a first casing in which a liquid crystal panel 3 is incorporated, 2 is a drive board 4 ( Figure 4) is incorporated into the second
This is the casing. The first casing 1 and the second casing 2 are
When not in use, they are closed overlapping each other as shown in Figure 4, and when in use, the fifth
As shown in the figure, it rotates via hinge means 6 to open the liquid crystal panel 3 to a predetermined angle. Since the liquid crystal panel 3 is driven by a signal from the drive board 4, the liquid crystal panel 3 and the drive board 4 are electrically connected by the lead wire 5.

However, the lead wire 5 with the above configuration is connected to the housings 1 and 2.
The required length of the lead wire 5 differs when the lead wire 5 is closed and when it is opened at the opening angle A, and the excess length when the lead wire 5 is opened causes deflection. By repeatedly being subjected to this bending, the lead wire 5 will eventually break.

FIG. 6 corresponds to FIG. 5 and shows the state of the lead wire 5 when the opening angle A is zero, that is, it is closed.
Further, FIG. 7 shows the state when it is opened at a predetermined angle A.

As shown in FIG. 6, the portion of the lead wire 5 that moves according to the rotation of the casings 1 and 2 has an arc shape, so that the arc formed by the rotation axis P of the hinge means 6 and the lead wire 5 is When the radius is r and the angle of the arc is β (radian), the length of the arc is expressed as rβ. This length is the maximum length that can accommodate rotation, so when it is opened to angle A, there will be a surplus. This surplus portion is subjected to an acute-angled deflection 7, as shown in FIG. Furthermore, this surplus ΔL is
If the angle of the arc formed by the lead wire 5 is α when the opening angle is set to A, then △L=r(β−α),
Since α is proportional to the opening angle A, it increases in proportion to the opening angle.

As mentioned above, the lead wire 5 that connects two printed wiring boards that are configured to be relatively rotatable, such as the liquid crystal panel 3 and the drive board 4, has an excess portion that bends in proportion to the rotation angle. There was an inconvenience that if the wire was repeatedly bent, the wire would break.

Furthermore, if the lead wires 5 are bent as described above, this will create resistance when the liquid crystal panel 3 is opened. Furthermore, a space is required in the housing to absorb the above-mentioned excess deflection, which imposes design constraints.

Further, in the above-mentioned connection structure, a load is applied to the contact portion between each printed wiring board and the lead wire, which sometimes causes a connection failure.

Conventionally, lead wires used in such locations are made of flexible boards that are resistant to plastic deformation due to bending to prevent wire breakage.

(Problem that the invention aims to solve) Conventionally, when connecting multiple printed wiring boards that rotate relative to each other using lead wires, the excess portion of the lead wires that occurs depending on the rotation angle is bent, resulting in disconnection. There was a problem of causing

The object of this invention is to solve the above-mentioned problems and provide a lead wire connection device that prevents unnecessary bending of the lead wire and prevents breakage of the lead wire.

[Structure of the invention] (Means for solving the problems) This invention connects two rotating printed wiring boards with a spirally wound lead wire.

(Function) According to this invention, since the lead wires are wound in a spiral shape, when one printed wiring board is rotated, the resulting change in the lead wires is compensated for by the spirally wound portion. Can be absorbed. Therefore, there is no bending as in the conventional case, and long-term reliability is ensured.

(Example) Hereinafter, an example in which this invention is applied to a liquid crystal television receiver will be described.

FIG. 1 is a perspective view showing an embodiment of the lead wire connecting device according to this invention. In the same figure, the first
The housing 11 and the second housing 12 are coupled via a hinge means 16. A liquid crystal panel 13 is provided in the first housing 11, and the liquid crystal panel 13 can be opened by rotating the first housing 11 about the rotation axis of the hinge means 16. The liquid crystal panel 13 and the drive board 14 are electrically connected by a tape-shaped lead wire 15 in which a large number of conductive wires are arranged in a line. A feature of this lead wire 15 is that it is spirally wound in a direction coinciding with the rotation axis of the hinge means 16. Reference numeral 17 indicates this arcuate portion.

In this type of lead wire connection device, as in the conventional case, there is a surplus in the lead wire 15 when the liquid crystal panel 13 is closed and when it is opened at a predetermined angle. Part 1 wrapped around
By changing the diameter of 7, the excess is absorbed and no bending occurs.

FIG. 2 corresponds to FIG. 6, and FIG. 3 corresponds to FIG. 7 (however, the opening angle A is an obtuse angle). Using the angles β and α in these figures and the number of turns n of the spiral, the surplus △L according to this invention is
is ΔL=r(β-α)/n (1).

Therefore, the radius r2 of the spiral portion 17 when the liquid crystal panel 13 is opened at a predetermined angle is changed to the radius r2 of the spiral portion 1 when the liquid crystal panel 13 is closed.
The difference △r obtained by subtracting the radius r1 of 7 can be expressed as △r=r(β-α)/2πn (2).

In this way, this invention absorbs ΔL by changing the diameter in the spiral portion 17 of the lead wire 15,
Unlike the conventional method, the surplus does not become deflection and load is not accumulated, so there is no possibility of wire breakage.
In such a case, Δr is extremely small, and there is no need to consider the storage space for the spiral portion when the liquid crystal panel is opened.

Furthermore, the load applied to the connector portion remains constant, and connection failures do not occur.

Note that the above embodiment is an example, and the number of turns of the spiral is arbitrary. Furthermore, if the lead wire has little elasticity, it may be wound around the rotating shaft member of the hinge means.

[Effects of the invention] As described above, this invention has the effect of preventing unnecessary bending from being applied to the lead wire and preventing wire breakage.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the lead wire connection device according to this invention, FIGS. 2 and 3 are explanatory diagrams for explaining the operation of the embodiment of FIG. 1, and FIG. 4 is a conventional FIG. 5 is a perspective view showing how an electrical device using the lead wire shown in FIG. be. 11...First case, 12...Second case, 1
3...Liquid crystal panel, 14...Drive board, 15...
Lead wire, 17... spiral portion.

Claims (1)

[Claims for Utility Model Registration] First and second printed wiring boards configured to be relatively rotatable via a hinge means; A lead wire connection device comprising: a lead wire that electrically connects a first printed wiring board and a second printed wiring board.