JP2002313189A - Multi directional switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multidirectional switch for cellular phone, camcorder or the like, having a key top fixing axis of which, the thickness is made thinner than ordinary product. SOLUTION: A key top mounting axis 32 is formed at the center part of an upper surface of a cross-shaped plunger 25, and a hemisphere-shaped part 26 divided so as to fit into the space between the arms, is formed. A spherical bearing is constructed by a spherical part at the lower surface of the pushing part 21 and the hemisphere- shaped part. Protrusions 30, 31, pushing contact point springs 29, are formed at the center part of the lower surface of the plunger 25, and at the lower surface of the top end part of the arms, and a gap, bigger than that at the center part, is formed between the protrusion 31 formed at the top end part of the arm and the contact point spring. By the above construction, the multidirectional switch of which, corresponding switching contact points are operated by pushing and slanting the key top forward, backward, leftward, and rightward, or pushing toward axial direction, with simple structure, very thin thickness, and small size, is materialized. Further, such a wrong operation that two switches are turned on simultaneously when the key top is slanted in the direction of the bisector of two arms of the plunger, is prevented by forming a plurality of protrusions 33 on the upper surface of the case.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-directional switch incorporated in a portable telephone, a portable stereo, a video camera, a digital camera, a vehicle audio system, and the like.

[0002]

2. Description of the Related Art A multi-directional switch is provided with a plurality of switch contacts, and one of the switch contacts is selected and operated according to a point of application and a direction of a force applied to an operation unit. And outputs several different signals depending on the operation. As an operation method,
For example, there is a type in which four types of inputs are performed by tilting an operation lever or a key top provided upright forward, backward, left, and right. Further, there is also a configuration in which a corresponding switch contact is operated even when the operating lever is depressed in the axial direction, instead of being tilted, and there are five types of inputs.

FIG. 11 is a cross-sectional view of an example of a multi-directional switch, which is disclosed in Japanese Patent Application Laid-Open No. Hei 10-188738. A central fixed contact 2, a common contact 3, and a peripheral fixed contact 4 are provided inside the housing 1 and the lid 11, and a central tact spring 6 and a peripheral tact spring 7 are placed thereon. The center tact spring 6 has a circular shape and a shallow dish shape, and its peripheral portion is in contact with the common contact 3 while riding on the common contact 3. The peripheral tact spring 7 is formed by three parallel rectangular pieces connected at the transverse portions at both ends to form an integral body. The outer rectangular piece is in contact with the common contact 3, but the central rectangular piece extends along the length. It is curved in an arch shape and is lifted in the middle, and is separated from the peripheral fixed contact 4 and located above. There is only one central tact spring 6 at the center, but there are a total of four peripheral tact springs 7, one at the front and the rear in addition to the two left and right tact springs 7 shown in the figure.

A first stem 8 is mounted on these tact springs.
And the second stem 10 are placed. The first stem 8 has a shape in which a cylindrical portion 8a and a hemispherical skirt portion 8b are overlapped, and a protrusion 8c around the lower surface of the skirt portion 8b is in contact with the peripheral tact spring 7. The second stem 10 is a quadrangular prism, fits in the square guide hole 9 of the first stem 8 and is slidable in the axial direction, and does not come off because of the presence of the flange 10a. A key top (not shown) or the like is attached to the upper end of the shaft protruding from the first stem 8. The lower pressing projection 10 b is in contact with the center tact spring 6.

The multi-directional switch is operated by moving the second stem 10. In order to operate the peripheral contacts, for example, when the key top attached to the upper end of the second stem 10 is pressed from the right and tilted to the left, the first stem 8 also integrally tilts to the left, and the left projection 8c Causes the peripheral tact spring 7 to invert the curvature of the central portion in a snap-like manner to come into contact with the peripheral fixed contact 4. As a result, the left common contact 3 and the peripheral fixed contact 4 conduct through the peripheral tact spring 7.

In this case, the hemispherical skirt portion 8b of the first stem 8 rotates while contacting the hole of the lid 11, and the flange portion 10a of the second stem 10 approaches the projection 1a on the housing 1. Therefore, even if a force is applied to push down the second stem 10 in the axial direction, the flange 10a hits the projection 1a and the second stem 10 does not move in the axial direction, and the pressing projection 10
b does not deform the center tact spring 6. Of the four protrusions 8c of the first stem 10, two invisible before and after the paper surface hardly displace, and the right protrusion 8c is separated from the peripheral tact spring 7 on the contrary. Thus, only the left switch is closed. When the second stem 10 is tilted rightward or forward or forward in the drawing, the same operation is performed in each direction.

When the upper end surface of the key top is pushed in the axial direction instead of tilting the second stem 10, the second stem 10 becomes the first stem.
Down along the guide hole 9 of the stem 8 of the
b deforms the center tact spring 6 and makes the center fixed contact 2 and the common contact 3 conductive. At this time, since the first stem 8 does not move, the peripheral tact spring 7 does not operate.

[0008] A first stem and a second stem are used to form a second stem.
A multidirectional switch in which the stem of the first embodiment slides in the guide hole of the first stem has the following structure different from that of FIG. Although not described in detail, the second stem operates the lower center contact as in FIG. 11, while the four sets of peripheral contacts are
Instead of being arranged on the bottom surface inside the housing as in 1, it is provided on the four side walls. When the coil spring protrudes from the first stem in all directions and the second stem is tilted sideways, the first stem also tilts and the coil spring comes into contact with the contact point on the wall, and when the tilt becomes a certain degree or more, When the spring force exceeds a certain level, the contacts on the wall close.

[0009]

As described above, the structure in which the operating portion is composed of the combination of the two members of the first stem and the second stem complicates the structure, increases the number of parts and increases the cost. In FIG. 11, the first stem has a shape in which a cylindrical portion 8a and a skirt portion 8b are stacked, and the second stem has a shape in which a shaft projects from a guide hole 9 of the first stem. And it is difficult to reduce the size and thickness. On the other hand, those in which the switch contacts are provided not on the bottom surface of the housing but on four walls or the coil springs are arranged sideways are complicated and have a high wall thickness, and it is also difficult to reduce the size and thickness. . The present invention solves these problems and realizes a multi-directional switch having a simple structure, a small number of parts, and suitable for miniaturization and thinning, which has a shaft for mounting a keytop.

[0010]

SUMMARY OF THE INVENTION The present inventors have previously developed a very thin multi-directional switch and have disclosed in Japanese Patent Application No. 11-16173.
No. 6 filed. The present invention solves the above-mentioned problem by further improving this. The multi-directional switch according to the above application is a flat type without a key top mounting shaft, and the operating unit is not a plurality of members, but is constituted by a single-part plunger having an arm extending in a cross shape from the center in four directions. In addition, contact springs are arranged at four places in the periphery corresponding to the tip of the arm and a total of five places at the center to detect five movements of the plunger. In the present invention, a shaft is added to the center of the plunger of this multi-directional switch to enable attachment of the key top, and furthermore, a projection is provided on the upper surface of the case between the arms of the plunger, and the key top is moved in the direction of the projection. When the key top is pressed, the lower surface of the key top hits the projection, so that the shaft does not tilt any more, so that the arms of the two plungers on both sides of the projection simultaneously act on the contact spring to prevent malfunction.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 4 shows the multidirectional switch of the above application, which will be described first for convenience. 2A is a plan view, FIG. 2B is a sectional view taken along line BB of FIG. 1A, and FIG. 1C is a sectional view taken along line CC. A case 21 made of synthetic resin, a spacer 22 made of polyimide or the like, and a circuit board 23 made of epoxy made of glass or the like are laminated. The case 21 has a cross-shaped hole 24 formed therein. Is stored. At the tip of the cross-shaped arm of the plunger 25, the gap between the arm and the hole 24 is reduced to prevent the plunger 25 from rotating.

As shown in FIG. 4B, since the pressing portion 27 of the case 21 presses the hemispherical portion 26 at the center of the plunger 25, the plunger 25 does not fall out of the hole 24. The spherical seat 27a on the lower surface of the holding portion 27 and the hemispherical portion 26 of the plunger 25 form a spherical plain bearing.

As shown in FIG. 1A, the spacer 22 is provided with one hole 28 at the center and four holes under each arm of the plunger 25, for a total of five positions.
Are placed in the holes 28 and positioned on the outline of the holes, and are mounted on the circuit board 23.

FIG. 5 shows the external appearance of the plunger 25. A hemispherical projection 30 is provided at the center of the lower surface, and a hemispherical projection 31 is also provided on the lower surface of the tip of each arm. 4B, the hemispherical portion 26 of the plunger 25 is in contact with the spherical seat 27a of the pressing portion 27 of the case 21 to form a spherical bearing, but the hemispherical portion 26 has a continuous shape as seen in FIG. Instead, it is divided into four parts and provided between the arms of the plunger 25. Although the plunger becomes thicker when the hemispherical portion and the arm are stacked, the plunger of FIG. 5 can be made thin because the hemispherical portion 26 is included in the thickness of the arm. FIG. 4 (A)
As shown in FIG. 7, the holding portion 27 of the case 21 is not also a continuous shape, and four portions extending between the arms of the plunger 25 from the periphery press the divided hemispherical portions 26 respectively. .

As can be seen from FIG. 4, the contact spring 29 is formed by bending a disk made of stainless steel or the like into a shallow dish shape, and its peripheral portion is in contact with a fixed contact pattern on the circuit board 23. Another fixed contact is provided on the substrate below the central portion. When the top of the contact spring 29 is pressed, the contact spring 29 buckles when the pressing force increases to a certain extent, and the direction of the curvature of the central portion is suddenly reversed with a sense of moderation, and the lower fixed contact is brought into contact with the lower fixed contact. And the central fixed contact are conducted through the contact spring 29. That is, each contact spring 29 and the fixed contact pattern on the circuit board 23 constitute an individual switch. In addition, on the lower surface of the circuit board 23,
A lead terminal for mounting on a circuit board of a device to be incorporated is provided, and a fixed contact on the upper surface of the board is connected to a lead terminal on the lower surface by a through hole or the like.

Although the contact spring 29 may have a simple dish shape, in FIG. 4, four feet are projected from the periphery and the feet are placed on fixed contacts on the circuit board 23. In this case, unlike a dish-shaped contact spring having no feet, the contact with the fixed contact is not at the entire circumference but only at the feet, so that the contact pressure increases and conduction is ensured. In addition, the provision of the feet can improve the rigidity and resiliency of the contact spring, which has the effect of helping the multidirectional switch to be smaller and thinner.

As shown in FIG. 4C, the plunger 25
A gap c is provided between the protrusion 31 at the tip of each arm of the plunger 25 and the four peripheral contact springs 29 in a state in which the protrusion 30 on the lower surface of the center is substantially in contact with the contact spring 29 at the center. Although not shown in the figure to avoid complication, a flexible thin protective sheet such as polyimide is sandwiched between the case 21 and the spacer 22 so that the case 21 and the spacer 22 are waterproof to the circuit pattern on the circuit board 23 and each contact spring 29. , Dust-proof structure. Therefore, the projections 30 and 31 on the lower surface of the plunger 25
Presses the contact spring 29 from above the protective sheet.

Next, the operation of the above multidirectional switch will be described. FIG. 6 shows a force F indicated by an arrow at the center of the plunger 25.
With the plunger 2 as shown in FIG.
5 is a spherical seat 27a on the lower surface of the pressing portion 27.
Away from the plunger 25, the plunger 25 descends in a substantially parallel posture, and the protrusion 30 on the lower surface of the center presses the contact spring 29 to reverse the curve, and the switch contact at the center closes. At this time, as for the peripheral switch contacts, the projection 31 on the lower surface of the tip of the arm of the plunger 25 does not deform the contact spring 29 yet, as seen in FIG. This is because the lowering of the plunger 25 is absorbed by the gap c between the projection 31 on the lower surface of the distal end of the arm and the contact spring 29 shown in FIG.

If the force F pushing the plunger 25 deviates even slightly from the center, the plunger 25 tends to tilt when descending, but in practice it does not close the peripheral switch contacts and cause malfunction. When the applied point of the force F is slightly displaced, the component of the force F applied to the distal end of the arm is significantly smaller than the force applied to the central portion due to the lever ratio of the plunger 25. Each arm is plunger 2
5 is a cantilever extending from the central portion, and slightly bends to absorb the movement. From these facts, as long as the point of application of the force F does not deviate much from the center, the contact spring 29
No force is generated to deform the contact and turn on the contact. When the central portion of the plunger 25 is pressed, only the central switch contact is closed.

FIG. 7 shows the center of the plunger 25,
This is the case where the tip of the arm is pressed with the force F. Plunger 25
As shown in FIG. 7C, the tip of the arm is lowered and inclined, and the projection 31 on the lower surface pushes the apex of the contact spring 29, and the curved shape is reversed to contact the fixed contact pattern on the circuit board 23. Then, the switch contact of this portion is closed. On the other hand, as shown in FIG. 2B, the plunger 25 is rotated by the reciprocal movement of the hemispherical portion 26 and the spherical seat 27a, and the central portion does not descend,
Therefore, the central switch contact does not operate.

Of course, if the point of application of the force F is slightly deviated toward the center, a component force for lowering the center of the plunger 25 is generated. The generated force becomes small due to the lever ratio of the plunger 25, and is absorbed by the elastic deformation of the plunger 25 itself, so that the force that deforms the contact spring 29 at the center is not generated. When the tip of the arm of the plunger 25 is pushed in this way, only the switch contact at that point is closed, and other switch contacts at the center and the periphery are not closed.

A shaft is provided on a thin multi-directional switch using such a cross-shaped plunger 25 so that a key top can be mounted. FIG. 8 shows this, and the basic structure of the switch is the same as that of FIG. 4, and the main parts are denoted by the same reference numerals as in FIG. Although the upper surface of the plunger 25 is flat in FIG. 4, which is the basic structure, the shaft 32 is provided on the upper surface of the plunger 25 as shown in FIG. Then, as depicted by the imaginary line, the key top 40 is pushed into the shaft 32 and attached.

FIGS. 8A and 8C show a force F indicated by an arrow.
When the upper end of the key top 40 is pressed in the direction of each arm of the plunger 25, the plunger 25 is tilted, and the contact spring 29 in that direction is pushed by the projection 31 on the lower surface of the tip of the arm to operate. Alternatively, if the upper end face of the key top 40 is pressed down, the plunger moves down and the center contact spring 29 is pressed by the projection 30 on the lower center face of the plunger 25 to operate. The state of this operation is the same as in FIGS.

FIG. 9 shows a plunger 2 according to this embodiment.
5 is an appearance. The cross section of the shaft 32 can be of any shape, such as a circle or a square, but in the present embodiment, the cross section of the shaft 32 is also a cross shape reflecting the cross shape of the plunger. If the cross-section is a cross, when the shaft 32 is pushed into the hole of the key top, the apex of the cross crosses the inner wall of the hole to increase the holding force, so that the key top does not easily fall off.

As shown in FIG. 8, the shaft 3
When the key top is mounted with the 2 provided, there is a problem which is not present in the case of the flat plunger 25 having no shaft as shown in FIG. In the multi-directional switch of the flat plunger 25 shown in FIG.
As can be seen from the plan view of FIG. 3A, the user pushes only within the cross-shaped contour of the plunger 25, and if the tip of the arm of the plunger 25 is pushed, the user tilts in that direction and the contact spring at that location Only 29 operates, but if the shaft 32 is provided on the plunger 25 as shown in FIG. 8 and the key top 40 is attached and operated, only the direction of the arrow F along the arm in FIG. Instead, the user can press and tilt the key top 40 in any direction if he or she wants to press it.

FIG. 10 shows a case where the key top is pressed in a direction different from that of the arm. Assuming that the key top 40 is depressed and tilted leftward in the middle direction between the arms as in the force F in FIG. 10A, the upper and lower two arms on the left are lowered as shown in FIG. The projection 31 deforms each contact spring 29, and two contacts are turned on at the same time. In order to eliminate such a malfunction, it is impossible to ask the user to press the key top 40 only in a predetermined direction, and a structure in which the contact does not operate if the user presses the key top 40 in a direction other than the normal one is required. desirable.

FIG. 1 shows an embodiment in which such a malfunction preventing structure is provided. Four protrusions 33 on the upper surface of the case 21
And the projection 33 is provided with the plunger 25 as shown in FIG.
The arm is disposed equidistant from the center of the plunger 25 between the arms. And plunger 2 as shown in FIG.
In the neutral state of 5, a gap c1 is provided between the lower surface of the key top 40 and the apex of the projection.

FIG. 2 shows the operation when the key top 40 of the multidirectional switch having the above structure is pushed leftward in the direction between the arms of the plunger 25. The key top 40 tilts to the left, but the lower surface hits the projection 33 and does not go down any further.
With this degree of inclination, the projection 3 on the lower surface of the arm of the plunger 25
Reference numeral 1 indicates a degree of contact only with the contact spring 29, which does not deform the contact spring 29 to turn on the contact.

FIG. 3 shows a case where the key top 40 is correctly pressed in the direction of any arm of the plunger 25. In the plan view of FIG. 7A, the position where the upper and lower left projections 33 are projected on the axis of the left arm of the plunger 25 and the distance from the plunger center are 7 times the actual distance between the plunger center and the projection 33. When viewed from the direction of FIG. 13B, the plunger 25 has a small descending amount at the position of the projection 33, and the tip of the left arm is sufficiently lowered before the lower surface touches the projection 33. The contact spring 29 is deformed.

In FIG. 1, when the key top 40 is pushed down without tilting, the projection 30 at the center of the lower surface of the plunger 25 is brought into contact with the contact spring at the center before the lower surface of the key top 40 yet contacts the projection 33. Press 29 to operate.

[0031]

As is apparent from the above description, according to the present invention, in a multidirectional switch in which switch contacts are arranged at a total of five places in the center and in four directions in the periphery, the operation section is not constituted by a plurality of members. By using a cross-shaped plunger having a low height and providing a shaft for attaching a keytop at the center of the plunger, the plunger can be made extremely thin. This corresponds to the height from the lower surface of the housing 1 of the conventional example in FIG. 11 to the upper surface of the cylindrical portion 8a of the first stem 8, and the upper surface of the plunger 25 (the root of the shaft 32) from the lower surface in the embodiment of the present invention in FIG. It is clear when comparing the heights up to.

In addition, in the conventional example, when attaching the key top to the upper end of the shaft of the second stem 10, the first stem 10 is placed between the lower surface of the key top and the upper end surface of the cylindrical portion 8a of the first stem 8. It is necessary to provide a gap corresponding to the stroke of the key top, which also causes an increase in the height of the component. In the present invention, as shown in FIG.
May be brought into close contact with the upper surface of the plunger 25.

Such a difference is that the operation unit of the conventional example shown in FIG. 11 has a double structure of a first stem and a second stem, and the first stem 8 is formed of a cylindrical portion 8a and a skirt portion 8b.
In contrast to the multi-story structure, in the present invention shown in FIG. 1, the operating portion is a single-part plunger 25, and the hemispherical portion 26 is divided and arranged at the same height as the arm as shown in FIG. .
Furthermore, in the present invention, by providing four projections on the upper surface of the case 21, it is possible to prevent a malfunction in which the plurality of contact springs 29 are simultaneously turned on when the key top 40 is tilted in the middle direction between the arms of the plunger 25. In. Thus, with a small number of simple components and a simple structure, a small and thin multidirectional switch having excellent functions and reliability and suitable for high-density mounting of circuits can be realized at low cost.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a multi-directional switch of the present invention.

FIG. 2 is an operation diagram of the multidirectional switch of the present invention.

FIG. 3 is another operation diagram of the multi-directional switch of the present invention.

FIG. 4 is a configuration diagram of a multidirectional switch on which the present invention is based.

FIG. 5 is a plunger used in the multidirectional switch of FIG. 4;

FIG. 6 is an operation diagram of the multidirectional switch of FIG. 4;

FIG. 7 is another operation diagram of the multi-directional switch of FIG. 4;

8 is a configuration diagram of a multidirectional switch in which a shaft 32 is added to the structure of FIG.

FIG. 9 is a plunger used in the multi-directional switch of FIG. 8;

FIG. 10 is an operation diagram of the multi-directional switch of FIG. 8;

FIG. 11 is a sectional view of an example of a conventional multidirectional switch.

[Explanation of symbols]

 2 Central fixed contact 3 Common contact 4 Peripheral fixed contact 6 Central tact spring 7 Peripheral tact spring 8 First stem 10 Second stem 21 Case 22 Spacer 23 Circuit board 24, 28 Hole 26 Hemispherical part 27 Pressing part 27a Spherical seat 29 Contact spring 30, 31, 33 Projection 32 axis

Claims (1)

[Claims] 1. A plurality of switch contacts are formed on a circuit board, and a plunger having a plurality of arms extending outward from a center is disposed thereon, and these are covered with a case. It has a hole along the contour of the arm, operably exposes and accommodates the arm, and has a holding portion that covers a part of the plunger to hold the plunger so that it does not fall off. One is located at the center of the plunger, and the other switch contact is located at the tip of the arm of the plunger. When the plunger descends almost in parallel, the switch contact at the center operates and the tip of the arm tilts. When the part is lowered, the switch contact at the tip part operates, so that any one of the switch contacts selectively operates according to a change in the posture of the plunger. A shaft for mounting the key top is formed at the center of the upper surface of the plunger, and a projection is provided on the upper surface of the case located between the arms of the plunger. When tilted in the direction of, the contact spring is pushed by the arm until the lower surface of the key top comes into contact with the projection, and it operates.
When the key top is tilted in the direction between the arms of the plunger, the contact spring is pushed by the arm and the key top is selected within the range where the lower surface and the projection come into contact before they operate. switch.