JP2005019352A - Multidirectional switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make a multidirectional switch for operations of a cell phone, video camera or the like more simplified, compact, and thinner than a prior art. <P>SOLUTION: One piece of a tact spring 14 and a contact spring 15 formed of an elastic thin plate of a conductive material are overlapped in a case with a base plate as a bottom and covered with a diaphragm 17 on which a plunger 16 is arranged. The contact spring has four or eight radial arms with a plurality of fingers at tips of each arm. When a stem 16b is pressed downward, the plunger presses the tact spring through the diaphragm and the contact spring to rapidly reverse a flexure, which gives birth to moderation to close a switch contact point at the center. When the stem is pressed laterally, the plunger is slanted to give birth to moderation by the tact spring, and each finger at the tips of the arms of the contact spring comes in contact with a corresponding fixed contact on the base plate, and detects operations in four directions, eight directions or the like. Contact pressure is generated by the elastic deformation of the arms of the contact spring to ascertain conduction with a moderation feeling accompanying an operation of each direction, so that the detection accuracy of the operation direction is improved by a combination of conductions of a plurality of the fixed contacts. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a multidirectional switch incorporated for operation of a mobile phone, a portable stereo, a video camera, a digital camera, an in-vehicle audio, and the like.
[0002]
[Prior art]
The multi-directional switch has a plurality of switch contacts, and is configured such that a certain one of the switch contacts is selected and operated according to the force application point and direction of the force applied to the operation unit. Depending on the difference, several different signals are output. As an operation method, for example, there is a method in which four or more inputs are performed by tilting an operation lever or stem provided upright to the front, back, left and right. Further, there is a configuration in which the corresponding switch contact is operated even if the operation lever is pushed down in the axial direction instead of being tilted, and the axial movement is added to the type of input.
[0003]
6A and 6B show an example of a conventional multi-directional switch. FIG. 6A is a plan view, and FIG. 6B is a cross-sectional view taken along line BB in FIG. A shallow dome-shaped tact spring 4 is placed in the central portion on the substrate 1 inside the case formed by the substrate 1, the cover 2, and the spacer 3, and a total of four tact springs 5 are arranged in the four directions around the periphery. The plunger 6 is placed on the tact spring group and covered with the cover 2.
[0004]
The plunger 6 in FIG. 6 has an octagonal flat plate body 6 a, and a stem 6 b is attached to the upper surface of the body 6 a, and the stem 6 b protrudes upward from the center hole of the cover 2. On the lower surface of the main body 6a, a projection 6c is provided at the center and four projections 6d are provided at the periphery. These projections are located at the center positions of the tact spring 4 and the tact spring 5, respectively. 4 is substantially in contact with the upper surface of 4, but a gap indicated by c is provided between the peripheral projection 6 d and the upper surface of the tact spring 5.
[0005]
Although not shown, an annular fixed contact is provided on the upper surface of the substrate on which the outer periphery of each tact spring is placed, and a circular fixed contact is provided at the center thereof. A plurality of arc-shaped recesses 1 a provided on the outer periphery of the substrate 1 are covered with a conductive material, and the electrode pattern on the upper surface of the substrate 1 is connected to the electrode terminal on the lower surface.
[0006]
When the switch is operated, first, when the upper end of the stem 6b is pushed downward, the projection 6c on the lower surface of the center of the plunger 6 pushes the center of the upper surface of the central tact spring 4 downward. When the pressing force is increased to some extent, the curvature of the tact spring 4 is suddenly reversed to create a feeling of moderation, and the center portion of the lower surface of the tact spring 4 comes into contact with the circular fixed contact on the substrate 1. The annular contact on which the outer periphery rides is connected to the circular contact at the center. At this time, since the surrounding four tact springs 5 have a gap c between the corresponding protrusions 6d on the outer periphery of the plunger 6, even if the plunger 6 descends, it does not deform as the shape reverses, There is no conduction.
[0007]
If the stem 6b is not pushed down but the upper end is pushed in the lateral direction, the plunger 6 is inclined, and the projection 6d in the pushed direction of the four projections 6d on the peripheral lower surface is lowered, and the tact spring 5 Is deformed to make the fixed contact at that point conductive. Thereby, this switch can detect the operation of pushing down the stem 6b and the operation of pushing in the four horizontal directions.
[0008]
Further, Patent Document 1 and Patent Document 2 below show other structures of the multidirectional switch. This is because the lower surface of the stem is made of a conductive material, only one tact spring is provided in the center, and a fixed contact is provided on the upper surface of the outer periphery of the substrate so that when the stem is tilted, it is electrically connected to the conductive material on the lower surface of the stem. It is a thing.
[0009]
[Patent Document 1]
JP 2000-353455 A [Patent Document 2]
JP 2001-35319 A
[Problems to be solved by the invention]
Among the conventional multi-directional switches, the one shown in FIG. 6 uses a tact spring for each contact, so that the number of parts increases and the product size increases, which is not suitable for miniaturization. Further, in the case of the operation of pushing the stem sideways, if the direction in which the force is applied is slightly shifted, two adjacent tact springs operate, and the operation direction cannot be identified, resulting in a malfunction. In addition, the device disclosed in the patent document requires a lot of work to manufacture the plunger in order to make the lower surface of the plunger conductive.
[0011]
The present invention solves these problems, is simple in structure, has a small number of parts, is suitable for downsizing and thinning, and further increases the detection direction of the lateral operation to 8 directions instead of 4 directions. A multi-directional switch that eliminates a signal caused by an ambiguous operation across directions and detects only an operation that correctly faces the detection direction is realized.
[0012]
[Means for Solving the Problems]
In the present invention, only one tact spring is used at the center of the multidirectional switch, and a contact spring made of a thin conductive material plate is provided between the tact spring and the plunger. Then, a fixed contact with which the contact spring contacts when the plunger is tilted is disposed on the substrate outside the central tact spring. A flexible partition is provided between the contact spring and the plunger, and the tact spring and the contact spring are covered and protected by the partition, but the partition may be omitted, and in this case, the contact spring may be attached to the plunger. This structure simplifies the configuration compared to that of FIG. 5 and, unlike the patent document, uses an elastic contact spring to increase the contact pressure due to elastic deformation when contacting a fixed contact. In addition, there is an advantage that conduction is ensured.
[0013]
When the plunger is tilted, the contact spring lowers the outer periphery and comes into contact with the fixed contact on the board to conduct, but the outer periphery is a radially branched arm, and the number of arms is the number of detection directions of the lateral operation. Is the same. The tip of each arm is further branched into a plurality of fingers. On the substrate, a fixed contact group corresponding to each of the plurality of fingers individually or in common is provided.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1A and 1B show a multidirectional switch according to the present invention, in which FIG. 1A is a top view and FIG. 1B is a cross-sectional view taken along line BB in FIG. A tact spring 14, a contact spring 15, and a plunger 16 are accommodated in a case in which a substrate 11 made of glass-containing epoxy or the like is used as a bottom and a spacer 13 made of polyimide or the like and a cover 12 made of synthetic resin are overlapped and joined. The substrate 11 and the spacer 13 may be formed integrally.
[0015]
The tact spring 14 has a shallow dome shape and is arranged at the center of the substrate 11, and the contact spring 15 is made of a thin plate made of an elastic conductive material such as stainless steel, and as shown in FIG. The basic cross-sectional shape is bent as shown in FIG. The plunger 16 has a stem 16b on the upper surface of a disk-shaped main body 16a, protrudes upward from a hole at the center of the upper surface of the cover 12, and has a spherical protrusion 16c at the center of the lower surface of the main body 16a.
[0016]
A flexible diaphragm 17 such as a thin resin sheet is stretched between the cover 12 and the spacer 13. The diaphragm 17 covers the lower tact spring 14 and the contact spring 15, and the contact spring 15 is interposed via the diaphragm 17. In contact with the lower surface of the plunger 16. A spherical downward recess is formed at the center of the contact spring 15, and a spherical protrusion 16 c on the lower surface of the plunger 16 is fitted into the recess to center the contact spring 15. Arc-shaped recesses 11 a are provided at a plurality of locations on the outer periphery of the substrate 11, and the surface of the recesses 11 a is conductively coated to connect the electrode patterns on the upper and lower surfaces of the substrate 11.
[0017]
The spacer 13 has a shape in which the central portion is punched out into a large hole, and the contact spring 15 is accommodated in this hole. As shown in FIG. 1A, a large number of protruding stoppers 13a are formed from the outer periphery of the hole. It protrudes inward and enters between the branched fingers of the contact spring 15 to prevent it from rotating.
[0018]
FIG. 2 shows a planar shape of the contact spring 15. This is made of a thin plate of an elastic conductive material as described above, but the outer periphery is branched into eight arms 15a, and the tip of each arm is branched into three fingers 15b, 15c, 15d. Yes.
[0019]
FIG. 3 shows an electrode pattern provided on the upper surface of the substrate 11, and the outline of the contact spring 15 is indicated by a broken line. There is an annular first fixed contact 21 around the second circular fixed contact 22 in the center, an annular fourth fixed contact 27 on the outer side, and eight third fixed contacts divided in a fan shape around it. A contact 23 is provided.
[0020]
A plurality of arc-shaped recesses 11 a on the outer periphery of the substrate 11 are conductively coated, thereby connecting the electrode patterns on the upper and lower surfaces of the substrate 11. The fan-shaped third fixed contacts 23 are electrically conductively covered by the wiring electrodes 26, respectively. The annular fourth fixed contact 27 is also connected to the central recess 11a on both the left and right sides. The annular first fixed contact 21 and the circular second fixed contact 22 are connected to the recess 11a on the lower surface of the substrate 11 by through holes 24 and 25, respectively.
[0021]
As can be seen by comparing FIG. 1 and FIG. 3, the dome-shaped tact spring 14 rides on the first fixed contact 21 whose outer periphery is annular, but the central ceiling is separated from the second fixed contact 22. In FIG. 3, among the eight arms 15a of the contact spring 15, the three fingers 15b, 15c, 15d at the tip of the right-pointing one are shown with black dots, but the finger 15b is a third fan-shaped fixed pin. Facing one of the contacts, the finger 15d faces another third fixed contact, and the finger 15c between the two fingers protrudes to the outer periphery of the annular fourth fixed contact 27 at eight equal intervals. It faces the substantially square electrode portion provided, and when viewed from the side, there is a gap between the tip of each finger and the fixed contact on the upper surface of the corresponding substrate 11 as shown in FIG. The above is the structure of the multidirectional switch of the present application.
[0022]
Next, the operation of this embodiment will be described. First, as shown by the arrow in FIG. 4, when the stem 16 b of the plunger 16 is pushed downward, the protrusion 16 c on the lower surface of the main body 16 a pushes the top of the tact spring 14 downward through the diaphragm 17 and the contact spring 15, and the load is increased. When the tact spring 14 is increased to some extent, the curvature of the tact spring 14 is reversed at a stretch to create a feeling of moderation, and the bottom surface of the tact spring 14 is in contact with the second fixed contact 22 in FIG. The first fixed contact 21 and the second fixed contact 22 are conducted.
[0023]
At this time, as shown in FIG. 4, the fingers at the tips of the arms of the contact spring 15 still have a gap between them and the fan-shaped third fixed contact 23 shown in FIG. There is no contact with the rectangular electrode protruding from the outer periphery of the contact 27, and electrical conduction does not occur. This is the operation when the plunger 16 is pushed down.
[0024]
Next, the case where the plunger 16 is pushed sideways will be described. For example, as shown by the arrow in FIG. 5, when the stem 16 b is pushed to the right, the plunger 16 tilts downward, and the protrusion 16 c on the lower surface of the main body 16 a pushes and deforms the tact spring 14 via the diaphragm 17 and the contact spring 15. A moderation is produced. At the same time, the tip of the right arm of the contact spring 15 is lowered and comes into contact with the fixed contact on the substrate 11. As seen in FIG. 3, among the three fingers with black dots of the right arm 15a, 15b and 15d contact the fan-shaped third fixed contact 23, and the central finger 15c is the annular fourth fixed. It contacts the square electrode protruding rightward from the outer periphery of the contact 27.
[0025]
As a result, two adjacent fan-shaped third fixed contacts 23 and the annular fourth fixed contact 27 are electrically connected to the first fixed contact 21 and the second fixed contact 22 via the contact spring 15 and the tact spring 14. . Each finger at the tip of the arm 15a of the contact spring 15 is elastically deformed due to an extra movement in which the plunger 16 is slightly tilted after coming into contact with the third fixed contact 23 and the fourth fixed contact 27, generating contact pressure and being electrically connected. Make sure.
[0026]
Thus, when the plunger 16 is tilted in the correct operation direction, two adjacent ones of the first fixed contact 21, the second fixed contact 22, the fourth fixed contact 27, and the third fixed contact 23, a total of five The fixed contacts are electrically connected to each other. The determination routine provided in the control software of the device determines that this state is a case where the plunger 16 is pushed sideways. By validating only such a combination, even if an ambiguous or inappropriate operation that goes in the middle of a predetermined direction in actual use is performed, they are excluded as meaningless and accurate. Only a simple operation can be detected with high accuracy.
[0027]
In the above embodiment, as shown in FIG. 1 to FIG. 3, the contact spring 15 is provided with eight arms 15a to detect the motion in eight directions. However, if the number of arms is four, four directions are detected. It becomes the specification of detection. However, it is of course possible to perform the detection operation in four directions by the control software while the number of arms is eight. The diaphragm 17 can be eliminated, and the contact spring 15 can be fixed to the lower surface of the main body 16a of the plunger 16.
[0028]
【The invention's effect】
As is apparent from the above description, according to the present invention, the multi-directional switch that detects the operation of pushing the plunger downward in the axial direction and the operation of pushing the plunger in the four horizontal directions or the eight directions can be configured very simply. Compared to a conventional structure that uses several tact springs, the number of parts is greatly reduced because there is only one tact spring, and the moderation is uniform when operating in any direction. A feeling is obtained.
[0029]
Since the contact spring bends after the tip contacts the fixed contact, the contact pressure increases and the reliability of continuity increases, and the tip of each arm of the contact spring is branched into multiple fingers, so that the direction in the lateral operation Detection accuracy is improved. Furthermore, since the electrode pattern, tact spring, contact spring and the like on the substrate are covered with a diaphragm, they are protected from dust, dirt, and the like. As described above, a small and thin multi-directional switch having various effects, excellent in function and reliability, and suitable for high-density circuit mounting is realized at low cost.
[Brief description of the drawings]
1A is a plan view of a multidirectional switch according to the present invention, and FIG. 1B is a cross-sectional view taken along line BB of FIG.
FIG. 2 is a plan view of a contact spring used in the multidirectional switch of the present invention.
FIG. 3 is an electrode pattern diagram on the substrate of the multidirectional switch of the present invention.
FIG. 4 is a cross-sectional view showing an operation when the multidirectional switch of the present invention is pushed downward.
FIG. 5 is a cross-sectional view showing an operation when the multidirectional switch of the present invention is pushed sideways.
6A is a plan view of an example of a conventional multidirectional switch, and FIG. 6B is a cross-sectional view taken along line BB of FIG.
[Explanation of symbols]
1, 11 Substrate 2, 12 Cover 3, 13 Spacer 4, 5, 14 Tact spring 15 Contact spring 6, 16 Plunger 17 Diaphragm 21 First fixed contact 22 Second fixed contact 23 Third fixed contact 24, 25 Through hole 26 Wiring Electrode 27 Fourth fixed contact

Claims (5)

The case is configured with the base plate provided with a fixed contact as the bottom, a shallow dome-shaped tact spring is arranged in the center of the base plate, and the contact spring and the plunger are stacked on top of each other and accommodated in the case.
The contact spring is made of an elastic thin plate of a conductive material, has a cross-sectional shape whose outer periphery is warped downward, branches to a plurality of radial arms with respect to the center, and further, the tip of each arm branches to a plurality of fingers, Two or more fingers face the fixed contacts divided on the outer periphery of the substrate with a gap therebetween, and the remaining fingers have an annular fixed contact provided immediately inside the fixed contact group on the outer periphery of the substrate with a gap. Facing
The multi-directional switch is characterized in that the plunger has a stem attached to the main body, the lower surface of the main body is in contact with the contact spring, and the stem projects upward from the hole in the center of the case. The multi-directional switch according to claim 1.
When the plunger is tilted, the tact spring is pushed by the plunger and the curve is reversed. Each finger at the tip of the touches the corresponding fixed contact,
The fixed contact at the center of the substrate or the annular fixed contact on the outer periphery of the tact spring, the divided fixed contacts on the outer periphery of the substrate, and the inner annular fixed contact in the immediate vicinity thereof are electrically connected via the tact spring and the contact spring. Multi-directional switch. The multi-directional switch according to claim 1.
The plunger has a protrusion at the center of the lower surface of the main body, the contact spring has a recess at the center, and the contact spring is centered by fitting the protrusion and the recess. The multi-directional switch according to claim 1.
A multi-directional switch comprising a plurality of stoppers projecting inward on an inner periphery of a case, and the contact springs being prevented from rotating by the stoppers. The multi-directional switch according to claim 1.
A multi-directional switch characterized in that a flexible diaphragm is provided between a plunger and a contact spring to cover the tact spring and the contact spring.

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