JPH08339844A - Grounding device - Google Patents

Abstract

PURPOSE: To hold the contact area of a grounding spring 3 and the contact part 1a of a thin plate 1 constant and to stabilize conduction without being affected by the thickness and the weight of a product. CONSTITUTION: The projection 3a of a spiral grounding spring 3 is fixed on a circuit board 2 and a thin plate 1 is pressed on the circuit board 2 via the grounding spring 3, whereby the grounding spring 3 is put into contact with a contact point 1a of the thin plate 1 and the thin plate 1 is brought into conduction with the circuit board 2. In this grounding device, a holding means for holding the contact area of the grounding spring 3 and the contact part 1a of the thin plate 1 constant is formed in the thin plate 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grounding device for electrically connecting a display device such as a liquid crystal display device and a control and drive circuit board of the device via a ground spring.

[0002]

2. Description of the Related Art A method for grounding a bezel for mounting a display device and a circuit board via a metal plate such as a copper plate for the purpose of electrical safety of a display device such as a liquid crystal display device or measures against EMI (static electricity). Alternatively, as shown in FIG. 3, the protruding portion 13a, which is one end of the spiral earth spring 13, is bent at a right angle,
A method of fixing the protruding portion 13a to the circuit board 12 with the solder 14 and pressing the bezel (thin plate) 11 toward the circuit board 12 to bring the thin plate 11 into contact with the upper surface of the earth spring 13 for grounding. As disclosed in Japanese Patent Laid-Open No. 62-59970, a method of forming a protrusion on a contact portion of a contact spring (in the present invention, an earth spring) and bringing the protrusion into contact with an end face of a battery or the like for grounding is adopted. .

[0003]

SUMMARY OF THE INVENTION In the above conventional one,
When the thin plate 11 and the circuit board 12 are electrically connected via the earth spring 13, the thin plate 11 is pressed toward the circuit board 12 side, so that the thin plate 11 is warped by the biasing force of the earth spring 13 as shown in FIG. Therefore, it is necessary to increase the thickness of the thin plate 11 or decrease the biasing force of the ground spring 13.

However, when the thickness of the thin plate 11 is increased, it affects the thickness and weight of the product, and the earth spring 1
When the biasing force of 3 is reduced, the thin plate 11 is connected to the circuit board 1
Since the repulsive force of the earth spring 13 is weak against the pressing force to the 2 side, the upper surface of the earth spring 13 cannot be completely contacted with the contact portion of the thin plate 11 and a gap is generated as shown in FIG. Due to this, there was a problem that the conductivity was not stable.

Further, when the thin plate 11 is pressed down toward the circuit board 12, the earth spring 13 contracts, but the contraction of the earth spring 3 increases the repulsive force, and the repulsive force causes the earth spring 13 to contact the contact portion of the thin plate 11. Cannot be maintained vertically, and the contact area between the contact portion of the thin plate 11 and the upper surface of the earth spring 13 becomes unstable. This tendency is caused by reducing the diameter of the earth spring 13. Therefore, if the diameter of the earth spring 13 is increased to stabilize it, there is a problem that the space and the biasing force of the spring increase.

The grounding device of the present invention solves the above problems, and does not affect the thickness and weight of the product, and keeps the contact area between the grounding spring and the contact portion of the metallic member constant. It is an object of the present invention to provide a grounding device which can be held and whose conductivity can be stabilized.

[0007]

According to a first aspect of the present invention for achieving the above object, one end of a spiral earth spring is fixed to a substrate, and a metallic member is pressed to the substrate side through the earth spring. In the grounding device for electrically connecting the metal member and the substrate while bringing the ground spring and the contact part of the metal member into contact with each other, holding the contact area between the ground spring and the contact part of the metal member to be constant. The means is formed on a metallic member.

According to a second aspect of the present invention, in the first aspect of the present invention, the holding means is a guide portion that makes a ground spring perpendicular to the metallic member at least when the metallic member and the substrate are electrically connected. is there.

According to a third aspect of the invention, in the second aspect of the invention, the guide has a convex portion formed at the center of the contact portion of the metallic member, and the convex portion is formed on the metallic member by sheet metal working. And is bent vertically.

[0010]

According to the present invention as described above, the invention according to claim 1 maintains the contact area between the earth spring and the contact portion of the metallic member at a constant value by the holding means, so that the metallic property is maintained through the earth spring. Conductivity between the member and the circuit board is stable.

According to a second aspect of the present invention, in the structure according to the first aspect, at least when the metallic member and the substrate are electrically connected, the earth spring is made perpendicular to the metallic member by the guide portion. And the contact portion of the metallic member are completely brought into contact with each other without a gap.

Further, in the invention described in claim 3, in the structure described in claim 2, a convex portion is formed at the center of the contact portion of the metallic member, and the convex portion is formed perpendicular to the metallic member by sheet metal working. The number of parts does not increase because the guide part is formed by bending the guide part.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the earthing device of the present invention is shown in FIG.
And it demonstrates in detail with FIG. FIG. 1 is a cross-sectional view of an essential part in a state in which a metallic member and a circuit board are grounded by the device of the present invention, and FIG. 2 is a cross-sectional view of an essential part in a state before being grounded shown in FIG.

In FIGS. 1 and 2, reference numeral 1 denotes a thin plate made of a metallic member for mounting a display device such as a liquid crystal display device on the main body of the device. The thin plate 1 is provided with a contact portion 1a, and the contact portion 1a is provided. A convex guide portion 1b is formed in the center.

Reference numeral 2 denotes a circuit board on which the display control and driving parts of the liquid crystal display device are mounted and wired, and a ground spring 3 formed by spirally winding a conductive linear member is fixed to the circuit board 2.

The guide portion 1b is a contact portion 1a of the thin plate 1.
A convex portion is formed in the center of the thin plate 1 and the convex portion is formed by sheet metal processing.
It is formed by bending it perpendicularly with respect to the plate 1. By forming the guide portion 1b in this way, the strength of the thin plate 1 can be increased and the biasing force of the earth spring 3 can be set to a large value. Can be thinned.

The earth spring 3 is formed by extending a linear member wound in a spiral shape from one end thereof and soldering 4 to the circuit board 2 so that the lower end of the earth spring 3 contacts the protruding portion 3a of the extended tip. By fixing it, it is grounded to the electric circuit.

By inserting the guide portion 1b of the thin plate 1 into the earth spring 3 and pressing the thin plate 1 toward the circuit board 2 side, the central axis of the earth spring is vertically guided to the contact portion 1a of the thin plate 1 at the ground spring. The upper surface of 3 is in contact with and electrically grounded.

According to the present invention configured as in the above embodiment, when the thin plate 1 is grounded, the convex guide portion 1b of the thin plate 1 is inserted into the ground spring 3 and the guide portion 1b is used to ground the spring 3. While vertically guiding the thin plate 1, the thin plate 1 is pressed toward the circuit board 2 side to
By bringing the contact portion 1a of the above into contact with the upper surface of the earth spring 3, the contact surface can be brought into complete contact with no gap as shown in FIG. 1, and stable conductivity can be obtained.

[0020]

Since the grounding device of the present invention is constructed as described above, the invention according to claim 1 is to hold the contact area between the grounding spring and the contact portion of the metallic member constant by the holding means. Since the electrical continuity between the metallic member and the circuit board via the earth spring is stable, highly reliable earth installation can be performed.

In addition to the effect of claim 1, the invention according to claim 2 makes the earth spring perpendicular to the metallic member by the guide portion at least when the metallic member and the substrate are electrically connected. As a result, the earth spring and the contact portion of the metallic member can be brought into complete contact with each other without a gap, so that the conductivity is better than in the first aspect.

Further, in addition to the effect of the above-mentioned claim 2, the invention of claim 3 forms a convex portion in the center of the contact portion of the metallic member, and the convex portion is formed on the metallic member by sheet metal working. Since the guide portion is formed by bending it vertically to form the guide portion, the number of parts is not increased by forming the guide portion, so that the grounding can be easily and inexpensively performed.

Further, since the strength of the metallic member is increased by bending the convex portion perpendicularly to the metallic member by sheet metal working to form the guide portion, when used for a liquid crystal display device, for example, a thin plate is used. Since the plate thickness can be made thin, the liquid crystal display device can be made thin and the weight thereof can be reduced, and the liquid crystal display device can be easily and inexpensively grounded.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a main part of a grounding device according to an embodiment of the present invention in a grounded state.

FIG. 2 is a cross-sectional view of a main part of a grounding device according to an embodiment of the present invention before being grounded.

FIG. 3 is a cross-sectional view of essential parts in a state in which the conventional grounding device is grounded.

FIG. 4 is a cross-sectional view of an essential part showing a state of grounding using a thin plate having a thin plate of a conventional grounding device.

FIG. 5 is a cross-sectional view of essential parts showing a state in which a conventional grounding device is grounded using a grounding spring having a weak biasing force.

[Explanation of symbols]

 1 thin plate 1a contact part 1b, 11b guide part 2, 12 circuit board 3, 13 earth spring 3a, 13a protruding part 11 bezel (thin plate) 4, 14 solder

Claims (3)

[Claims] 1. An end of a spiral earth spring is fixed to a substrate, and a metallic member is pressed toward the substrate through the earth spring to bring the metal into contact with the earth spring and a contact portion of the metallic member. A grounding device for electrically connecting a conductive member and a substrate, wherein a holding means for holding the contact area between the grounding spring and the contact portion of the metal member constant is formed on the metal member. 2. The earthing device according to claim 1, wherein the holding means is a guide portion that makes a grounding spring perpendicular to the metallic member at least when the metallic member and the substrate are electrically connected to each other. 3. The guide portion is characterized in that a convex portion is formed at the center of the contact portion of the metallic member, and the convex portion is bent perpendicularly to the metallic member by sheet metal working. Grounding device as described.