JP2005243320A - Multidirectional switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent malfunctions of switching on a contact point of an outer periphery by being unsteady and leaning when a plunger is plunged, in a multidirectional switch for operation of a cellular phone, a video camera, or the like. <P>SOLUTION: A tact spring 4 and a contact point spring 5 are laminated and covered by a separating membrane 7 on which a plunger 36 is placed in a case having a substrate 1 as a bottom part and a cover 22 as an upper part, a short cylinder part 22b is provided on an underside around a center hole of the cover, and then, another short cylinder part 36e surrounding the above short cylinder part is provided on an outer periphery of a flange 36a of the plunger. For example, the plunger leans toward right in a condition being pressed in because of a movement rotating to the right with a point x where an inner peripheral upper end of the short cylinder part 36e contacts an outer periphery of the short cylinder part 22b as a center of rotation, but it is stopped by hitting the case at a position y. The position x is higher and nearer to a root of the short cylinder part 22b in an operation of inclining the plunger, so that a relative movement of the plunger and the case at the y position is as if each passed the other, and therefore, the rotation of the plunger is not interrupted. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  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.

  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 are methods 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 switch contact corresponding to an axial movement instead of an inclination of the operation lever, and an axial pressing movement is added to the input type.

  In a conventional multi-directional switch, five shallow dome-shaped tact springs are arranged at a total of five locations in the central part of the substrate inside the case and in the four directions around it. There was a configuration in which a plunger was placed and covered with a cover. The tact springs each have an outer periphery on the annular fixed contact of the substrate, and a circular fixed contact is provided on the substrate below the top of the dome. When the apex of the tact spring is pushed by the operation of the plunger and the curve is reversed, the apex of the dome comes into contact with the lower circular fixed contact, and the circular fixed contact and the annular fixed contact surrounding it are conducted.

  In this multidirectional switch, the lower end of the plunger is substantially in contact with the apex of the central tact spring in a stationary state, but the outer peripheral portion of the plunger is provided with a slight gap between the apex of the peripheral tact spring. When the user depresses the plunger vertically, the central tact spring is pushed and deformed, and the central switch contact conducts to detect axial movement, but the movement of the plunger is absorbed by the gap in the periphery. Therefore, the surrounding tact springs do not operate when the plunger is lowered.

  On the other hand, when the user pushes the plunger sideways, the plunger tilts and the outer periphery descends more than the gap, deforms the surrounding tact spring, and the annular fixed contact on which the tact spring rides and the center circular shape Fixed contact conducts. At this time, the center tact spring is not deformed or slightly deformed, and the center switch is not turned on. By using such a switch structure and control software in combination, an operation of tilting the plunger in four directions or eight directions is detected.

  However, since such a multi-directional switch uses a tact spring for each contact, the number of parts increases and the package size increases, which is not suitable for miniaturization. Therefore, the present inventors previously proposed a multi-directional switch having a simple structure according to Japanese Patent Application No. 2003-129634. FIG. 5 is an example of a multidirectional switch according to the structure of the application.

  The multidirectional switch shown in FIG. 5 has a tact spring 4, a contact spring 5, and a plunger in a case where a substrate 1 made of glass-filled epoxy or the like is used as a bottom, and a spacer 3 made of polyimide and a cover 2 made of synthetic resin are overlapped and joined. 6 is housed. The tact spring 4 has a shallow dome shape and is arranged at the center of the substrate 1, and the contact spring 5 is made of an elastic thin plate made of a conductive material such as stainless steel. The arm has eight arms extending in the shape of the arm, and the tip of the arm warps downward, and a pan-shaped downward recess is formed in the center of the hub. The inventors have filed another contact spring 5 in which the tips of the radial arms are connected by an annular rim for other purposes.

  The plunger 6 has a stem 6b on the upper surface of the disc-shaped flange 6a, protrudes upward from the hole 2a at the center of the upper surface of the cover 2, and has a pan-like projection 6c at the center of the lower surface of the flange 6a. FIG. 5 shows the stem 6b with the key top 8 attached.

  A flexible diaphragm 7 such as a thin resin sheet is sandwiched between the cover 2 and the spacer 3, and the diaphragm 7 covers the tact spring 4 and the contact spring 5. The diaphragm 7 may be completely sandwiched between the flange 6 a of the plunger 6 and the upper surface of the contact spring 5, but in FIG. 5, a hole is formed in the center of the diaphragm 7, and the protrusion 6 c on the lower surface of the plunger 6. Comes out of the hole and fits into a pan-shaped recess at the center of the contact spring 5 to center the contact spring 5. These three parts are integrally bonded by bonding the plunger 6 and the contact spring 5 to the upper and lower surfaces of the diaphragm 7 respectively. Arc-shaped recesses 1a are provided at a plurality of locations on the outer periphery of the substrate 1, and the surface of the recesses 1a is conductively coated to connect the electrode patterns on the upper and lower surfaces of the substrate 1.

  FIG. 6 shows a pattern of electrodes provided on the upper surface of the substrate 1, in which a ring-shaped first fixed contact 11 is provided around a central circular second fixed contact 12, and further, eight pieces divided in a fan shape on the outside thereof. The third fixed contact 13 is provided. A plurality of arc-shaped recesses 1 a on the outer periphery of the substrate 1 are conductively coated to connect the electrode patterns on the upper and lower surfaces of the substrate 1. The fan-shaped third fixed contacts 13 are respectively connected to the recesses 1 a by the wiring electrodes 16. Connected to the conductive coating. The annular first fixed contact 11 and the circular second fixed contact 12 are connected to the recess 1a on the lower surface of the substrate 1 by through holes 14 and 15, respectively.

  As can be seen by comparing FIG. 5 and FIG. 6, the dome-shaped tact spring 4 rides on the first fixed contact 11 whose outer periphery is annular, but the apex of the dome is separated from the second fixed contact 12. The lower peripheral edge of the contact spring 5 is located above the sector-shaped third fixed contact 13, and a gap is formed between the contact spring 5 and the third fixed contact 13.

  The operation of this multi-directional switch will be described. First, when the plunger 6 is pushed downward as shown by the arrow in FIG. 7, the protrusion 6 c on the lower surface of the flange 6 a moves the apex of the tact spring 4 downward through the contact spring 5. When the load is increased to some extent, the bending of the tact spring 4 is reversed at a stretch to create a feeling of moderation, and the lower center surface of the tact spring 4 contacts the second fixed contact 12 of FIG. As a result, the annular first fixed contact 11 and the second fixed contact 12 on which the outer periphery of the tact spring 4 rides are conducted. At this time, as shown in FIG. 7, the outer peripheral lower edge of the contact spring 5 is still spaced from the substrate 1 and does not contact the fan-shaped third fixed contact 13 of FIG. Absent.

  Next, for example, as shown by the arrow in FIG. 8, when the plunger 6 is pushed to the right, the plunger 6 tilts to the right, and the protrusion 6 c on the lower surface pushes the tact spring 4 via the contact spring 5 to deform it. Arise. At the same time, the lower edge of the right end of the contact spring 5 is lowered and comes into contact with the fan-shaped third fixed contact 13 on the substrate 1 shown in FIG. As a result, the third fixed contact 13 is electrically connected to the first fixed contact 11 and the second fixed contact 12 via the contact spring 5 and the tact spring 4. The right side portion of the contact spring 5 is elastically deformed by an extra movement in which the plunger 6 is further inclined after coming into contact with the third fixed contact 13, and a contact pressure is generated to ensure electrical conduction.

  When the plunger 6 is tilted in this way, the three fixed contacts 11, 12, 13 are conducted, and the first and second fixed contacts 11, 12 are shown in FIG. As shown in FIG. 7, the same conduction as when the plunger 6 is pushed down occurs. However, this is because the operation of the plunger 6 is pushed by monitoring the state of the third fixed contact 13 with the control software of the device. Identify that it was tilted. By such a structure and action, in addition to the operation of pushing the plunger 6 downward, the operation of pushing in the horizontal 4 direction or the 8 direction is detected.

  However, such a conventional multidirectional switch has the following problems. That is, the plunger 6 tends to tilt even in an operation of pushing the plunger 6 without intention of tilting. For example, in FIG. 9, while the plunger 6 is pushed down, it tilts to the right and the right end of the contact spring 5 falls and hits the fixed contact on the substrate 1, resulting in a malfunction. This is because the gap between the hole 2a on the upper surface of the cover 2 and the stem 6b of the plunger 6 protruding from the hole 2a is increased, so that the inclination of the plunger 6 is not regulated, and the posture is stabilized and pushed in. Because it is difficult.

  In order to prevent this, it is conceivable to reduce the gap between the hole 2 a on the upper surface of the cover 2 and the stem 6 b of the plunger 6. An example thereof is the multi-directional switch shown in FIG. 10. Here, unlike the previous plunger 6, an intermediate portion 26 d having a diameter larger than that of the stem 26 b is provided on the flange 26 a of the plunger 26, and the holes of the intermediate portion 26 d and the cover 2 are provided. The gap is kept to a minimum and the wobbling of the plunger 6 is prevented.

  This structure has no problem in the operation of pushing the plunger 26 right below, and even if the plunger 26 tends to tilt to the right when pushed downward as shown in FIG. Since the gap of the portion 26d is small, a gap is generated at the x position on the left side in the figure, but the intermediate portion 26d hits the inner wall of the hole of the cover 2 at the y position on the right side, and the plunger 26 is further to the right. Inclination is prevented, and the lower edge of the right end of the contact spring 5 does not need to contact the fixed contact on the upper surface of the substrate 1.

  However, this structure has another drawback. That is, even when the user tries to incline the plunger 26, a state in which the inclination of the plunger 26 is stopped as shown in FIG. 11 occurs. In FIG. 11, when the user attempts to tilt the stem 26d to the right via the key top 8, the plunger 26b moves slightly to the right, creating a gap at the x position on the left side of the figure, and the right side of y. At the location, the outer periphery of the intermediate portion 26d hits the inner wall of the hole of the cover 2 and no longer tilts. The same applies to the case of tilting in another direction. As a result, the outer peripheral switch contacts are not turned on, and the basic function of the multidirectional switch is hindered.

As another method for preventing such an obstacle, there is a plunger that is not an integral structure as in the previous example, but a flange and a stem that are separated from each other. An example of this can be seen in Patent Document 1 below.
JP, 10-188738, A Although illustration is omitted, in this prior art, in addition to the central tact spring, four tact springs are arranged on the outer periphery, and a through hole is provided in the center of the flange. It is a structure through the stem.

According to this structure, when the plunger is tilted, the stem and the flange are integrated and tilted, and when the plunger is pushed down, the flange is stationary, and only the stem is guided and lowered by the hole of the flange. There is no. However, in this structure, since the plunger is composed of two parts, the number of parts is increased as compared with the conventional example of FIG.
The object of the present invention is to solve the above problems while maintaining a simple structure as in the conventional examples of FIGS.

  In order to solve the above problems, in the present invention, a downward short cylindrical portion is provided on the lower surface around the hole of the cover in which the plunger is fitted. On the other hand, an upward short cylindrical portion is provided on the outer peripheral portion of the flange of the plunger, and this surrounds the short cylindrical portion of the cover. The outer circumference of the short cylindrical portion of the cover and the inner circumference of the short cylindrical portion of the plunger are tapered, and when the plunger is lifted by a tact spring and is in a stationary position, the outer circumference of the short cylindrical portion of the cover and the short cylindrical portion of the plunger are The inner circumference should be almost touching.

  This structure works as follows. That is, when the plunger is first pushed downward, the plunger descends and the basic tact spring is switched on as usual, but if the plunger is slightly lowered and tries to tilt to the left or right, The inner peripheral upper end of the short cylindrical portion provided on the outer peripheral portion of the flange hits the outer periphery of the short cylindrical portion provided around the hole of the cover, and the plunger is such that this point is the center of rotation and the opposite side of the flange is lowered. However, the upper end of the middle part of the plunger fitted in the hole of the cover hits the inner surface of the hole and cannot tilt further. At this time, the outer periphery of the inclined side of the contact spring below the plunger does not come into contact with the fixed contact on the substrate.

  As described above, the movement in which the plunger is staggered during the pushing operation of the plunger is restrained. However, when the user intentionally tilts the plunger, the plunger tilts without being hindered. This is because in an operation to tilt the plunger, the plunger starts to tilt with almost no lowering. Therefore, the upper end of the short cylindrical portion of the upper surface of the flange of the plunger hits the outer periphery of the short cylindrical portion of the cover. The center of rotation is located above the center of rotation when the plunger is swung to push the plunger as described above.Therefore, near the upper end of the middle part of the plunger opposite to the center of rotation, the inner periphery of the hole in the cover It is because it moves so as to pass the inner circumference with a slight gap without hitting it.

  According to the present invention, when the plunger of the multi-directional switch is pushed in, the plunger is inclined and the outer peripheral contact is inserted unintentionally, or conversely, even if the plunger is inclined, it is caught on the inner periphery of the hole in the cover. A malfunction that does not move can be prevented with the same simple configuration as before without increasing the number of parts. As a result, a multi-directional switch with excellent performance and reliability can be realized at low cost.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a multidirectional switch according to the present invention. Although the basic configuration is almost the same as that of the conventional example of FIG. The characteristic part of the present invention will be described mainly. In the embodiment, first, the short cylindrical portion 22b is provided downward on the lower surface of the cover 22 around the central hole from which the plunger 36 protrudes.

  Further, the plunger 36 has a shape with an intermediate portion 36d having a diameter larger than that of the stem 36b at a place where it fits into the hole of the cover 22 to reduce the gap between the hole and the short cylindrical portion on the outer peripheral portion of the flange 36a. 36e is provided so as to surround the short cylindrical portion 22b of the cover 22 in an upward direction. The outer circumference of the short cylindrical portion 22b and the inner circumference of the short cylindrical portion 36e are tapered at substantially the same angle, and the protrusion 36c on the lower surface of the flange 36a rides on the tact spring 4 via the contact spring 5 as shown in FIG. In this state, the outer circumference of the short cylindrical portion 22b and the inner circumference of the short cylindrical portion 36e are almost in contact with each other.

  The operation of the embodiment having such a structure will be described. First, when the plunger 36 is pushed down as shown in FIG. 2, the plunger 36 pushes and deforms the tact spring 4 via the contact spring 5 as in the conventional example of FIG. 7, and the central switch contact is conducted. FIG. 3 shows how the plunger 36 is prevented from wobbling right and left at this time. In this figure, the plunger 36 is about to tilt to the right. When the plunger 36 receives a rightward force and tries to move to the right, the inner left side of the short cylindrical portion 36e immediately hits the outer periphery of the short cylindrical portion 22b of the cover 22, but the right side surface of the intermediate portion 36d and the hole of the cover 22 A slight gap remains between the right inner surface. Thereafter, the plunger 36 tends to tilt to the right. This is based on the point (point x in the figure) where the upper left inner peripheral edge of the short cylindrical portion 36e hits the outer periphery of the short cylindrical portion 22b of the cover 22 as a center of rotation. This is a movement in which the plunger 36 tries to rotate to the right.

  Since the gap between the hole of the intermediate portion 36d of the plunger 36 and the cover 22 is made small, when the plunger 36 tries to rotate to the right around the point x, the right side surface of the intermediate portion 36d indicated by y in the figure and the cover The slight gap on the inner surface of the hole 22 is immediately clogged, and the intermediate portion 36d hits the inner surface of the hole, and the clockwise rotation of the plunger 36 stops there. At this time, as shown in the figure, the right end of the contact spring 5 has a sufficient gap with respect to the upper surface of the substrate 1, so that the contact on the outer periphery does not conduct and no malfunction occurs.

  Next, an operation for tilting the plunger 36 will be described. When the plunger 36 is pushed to the right in FIG. 4 to be inclined, the upper end of the inner periphery on the left side of the short cylindrical portion 36e hits the outer periphery of the short cylindrical portion 22b of the cover 22 as shown by x in the figure. Rotate right around the center of rotation. At this time, in the location indicated by y in the figure, there is a slight gap between the right side surface of the intermediate portion 36d of the plunger 36 and the inner periphery of the hole of the cover 22, and the right side surface of the intermediate portion 36d is almost the inner surface of the hole. Since it moves in parallel, rotation is not hindered. As a result, the right outer edge of the contact spring 5 is sufficiently lowered to contact the fixed contact on the substrate 1, and the switch on the outer periphery is conducted.

  The operation of pushing the plunger 36 as shown in FIG. 3 stops the inclination of the plunger 36, and the operation of pushing it sideways as shown in FIG. 4 causes the plunger 36 to be freely inclined as follows. In each drawing, the rotation center of the movement of the plunger 36 tilting to the right is indicated by x, and x corresponds to the upper end of the inner periphery of the short cylindrical portion 36e, but FIG. Is lowered to near the lower end of the short cylindrical portion 22 b of the cover 22. On the other hand, in FIG. 4, the plunger 36 is not lowered because it is pushed to the right, and the position of x is higher than that of FIG.

  When the vertical position of the rotation center x is different in this way, the position of the right side surface of the plunger 36 in FIG. 3 where the symbol y is attached has a low position of the rotation center x, and therefore the inner wall of the hole in the cover 22 as the plunger 36 rotates. It approaches and approaches and does not rotate any further. On the other hand, in FIG. 4, since the position of the rotation center x of the plunger 36 is high, the outline of the portion marked with y on the right side of the intermediate portion 36d of the plunger 36 is substantially along the arc centered on x. The portion moves without interfering with the periphery of the hole in the cover 22, and the plunger 36 can rotate if there is a slight gap at the position y.

  As seen in FIG. 1 and others, the intermediate portion 36d of the plunger 36 has a side surface shape that is tapered or arcuate above the upper end of the short cylindrical portion 36e, and has a shape that is slightly tapered as it goes upward. As can be seen from the above description, the contour shape of this portion of the intermediate portion 36d must be close to an arc centered at the point x in FIGS. If 36d is a short cylinder with a uniform diameter, the upper part of the side surface of the intermediate part 36d hits the inner surface of the hole of the cover 22 during the operation of inclining the plunger 36, and the desired operation cannot be performed.

It is sectional drawing of the multidirectional switch of this invention. It is sectional drawing which shows the operation | movement when pushing in the multidirectional switch of FIG. It is sectional drawing which shows a mode that the plunger inclines a little in the state of FIG. It is sectional drawing which shows the operation | movement when pushing the multidirectional switch of FIG. 1 sideways. It is sectional drawing of the conventional multidirectional switch. It is an electrode pattern figure on the board | substrate of the multidirectional switch of FIG. It is sectional drawing which shows the operation | movement when pushing in the multidirectional switch of FIG. It is sectional drawing which shows the operation | movement when pushing the multidirectional switch of FIG. 5 sideways. It is sectional drawing which shows a mode that the plunger inclined slightly in the state of FIG. It is sectional drawing of another conventional multidirectional switch. It is sectional drawing which shows a mode that the plunger inclined slightly when pushing in the multidirectional switch of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Board | substrate 2 Cover 3 Spacer 4 Tact spring 5 Contact spring 6, 26 Plunger 7 Diaphragm 8 Key top 11 1st fixed contact 12 2nd fixed contact 13 3rd fixed contact 14, 15 Through hole 16 Wiring electrode 22 Cover 22b Short cylindrical part 36 Plunger 36e Short cylindrical part

Claims (3)

The case is composed of a base plate with a fixed contact as the bottom, a shallow dome-shaped tact spring is placed in the center of the base, and a contact spring whose outer periphery faces a contact group around the tact spring, and a flange and stem. In the multi-directional switch in which the plungers arranged in this order are accommodated in the case, and the plunger stem protrudes upward from the hole in the center of the case,
An intermediate part larger in diameter than the stem is provided between the flange of the plunger and the stem, and the gap between the outer periphery of the intermediate part and the inner periphery of the hole of the case is reduced,
A multidirectional switch, characterized in that a short cylindrical portion is provided downward on the lower surface around the hole of the case, and a short cylindrical portion surrounding the short cylindrical portion is provided on the upper surface of the flange of the plunger. The multi-directional switch according to claim 1.
The outer circumference of the short cylinder around the hole in the case and the inner circumference of the short cylinder of the plunger flange are tapered so that the outer circumference and the inner circumference are almost in contact when the multi-directional switch is stationary. Multi-directional switch characterized by that. The multi-directional switch according to claim 1.
In the intermediate portion of the plunger, the side surface shape of the portion above the upper end of the short cylindrical portion on the upper surface of the flange has sunk upward along an arc centering on the inner peripheral upper end on the opposite side of the short cylindrical portion. A multidirectional switch characterized by its shape.

Images