KR100388504B1 - Key switch - Google Patents

Abstract

The present invention relates to a key switch that can realize a click feeling with a simple structure, and receives a key top that receives pressure from a user's finger, and receives a pressure of the key top to recognize a key operation and pushes the key top upward when the pressure is released. In a key switch composed of an uplink and an FPC (Flexible Printed Circuits) arranged on an upper surface of the keyboard frame and recognizing a key operation by the pressure contact of the link, the link is axially coupled to the frame. A first leg axially coupled to the second leg, a second leg axially coupled to the first leg and freely engaged with the frame through a long hole, and providing a return force to the key top A return leaf spring and a contact leaf spring in pressure contact with the FPC are provided so that the key top is pressed downward against the elastic force of the return leaf spring. (D) The second leg and the frame undergo a relative sliding movement through the long hole, and then the relative motion is stopped at the end of the long hole, and if the pressure load continues to increase, the return spring surrenders and the pressure load is increased. This sharp decrease reduces the height of the key switch that provides a feeling of click. The pair of holes are formed in the frame, and the projections formed at the end of the second leg are inserted into the holes, and the FPC is positioned between the projection and the frame. It features.

The key switch of the present invention has a technical effect that the link structure is simple and a sufficient click feeling can be obtained.

Description

Key Switch {KEY SWITCH}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a key switch used in a keyboard or the like used as an input device such as a personal computer (PC). In particular, a large key stroke can be realized while the keyboard is made smaller and thinner. The present invention relates to a key switch capable of ensuring a key operation feeling and a key input by providing a click feeling during key operation. The present invention also relates to a key switch that simplifies the assembly process by simplifying the overall configuration.

In recent years, as the size of the keyboard becomes smaller, the key-top becomes thin and flat, and in order to improve the operability of the key input and to ensure the certainty of the key input, a large keystroke is required for the key operation and a certain click feeling is required. It became. Various key switches have been proposed as key switches used in such a keyboard.

For example, Japanese Patent Laid-Open No. 8-279316 proposes the following key switches.

That is, the guide member for guiding the vertical movement of the key top comprises a first link member and a second link member, and the first and second link members are combined in an X shape to guide the vertical movement of the key top. The first link member is formed with a spring member having a switch operating portion at the end thereof, and an inclined protrusion having an inclined surface is formed at the support plate. The spring member slides along the inclined surface of the inclined protrusion to increase the pressure load of the key top. As the spring member falls over the inclined protrusion and falls on the switch seat surface, the pressure load is suddenly lowered to give a click feeling. At the same time, the switch actuating portion of the spring member is brought into contact with the pressing portion of the switch to perform a key operation.

The key switch can achieve miniaturization and thinning of the keyboard by using a guide member of a link structure without using a rubber spring. In addition, the inclined protrusion is formed on the support plate, so that the switch operating portion of the spring member slides over the inclined protrusion to change the pressure load to impart a click feeling.

However, the conventional guide member of the link structure is composed of the first link and the second link, and the assembly is made by assembling them, which requires a lot of labor for the assembly and has the disadvantage of increasing the manufacturing cost.

In addition, there is also a disadvantage in increasing the manufacturing cost by processing the support plate, such as forming an inclined protrusion on the support plate to obtain a feeling of click.

In addition, there is a problem that the noise is generated by directly hitting the frame without absorbing the impact of the key top is lowered.

In addition, axial coupling is used to connect the frame and the link, and the projections for this contact directly with the frame, and the projections made of soft materials such as plastic are easily worn due to friction with the frame made of aluminum. There was a disadvantage in that the life of the entire key switch is shortened.

In addition, the FPC placed on the frame is moved without being fixed, the place where the contact point of the FPC and the pressure of the key top is shifted, there is a problem that the key operation is not made because the correct contact is not pressed even when the key top is lowered.

In addition, the drainage key switch used for special keys such as space and enter has a long length, so if pressure is applied to the key top, the pressure is not evenly transmitted to the link, so that the key top is skewed, thus ensuring a reliable contact force. There were problems such as hard to get. To this end, the pressure is evenly transmitted using a link bar, but there is a problem of increasing the cost because an additional process is required during assembly.

The present invention therefore seeks to provide a compact, thin and inexpensive key switch by providing a guide member with a simple link structure.

In addition, a simple structure is to provide a key switch that provides a feeling of click.

It is also an object of the present invention to provide a key switch with low noise and accurate key switch operation.

In addition, in a drain key switch, a key switch is provided in which pressure is equally transmitted.

1 is a perspective view of a key switch of the present invention;

Figure 2 is a view showing that the key switch of the present invention in a non-pressure state, (a) is a plan view, (b) is a side view, (c) is a side view cut a part;

3 is a view showing a state in which the keyswitch of the present invention is lowered under pressure, (a) is a plan view, (b) is a side view, (c) is a side view of a part cut,

4 is a view showing a link of the present invention, (a) is a perspective view before assembling, (b) is a plan view when assembling, (c) is a side view when assembling,

Figure 5 shows another embodiment of the present invention, (a) is an embodiment in which one return leaf spring is formed, (b) is an embodiment in which the contact leaf spring is connected to both wings,

Figure 6 is a view showing the relative movement of the second leg projection and the second leg hole in one embodiment of the present invention,

7 is a view showing a relationship between a stroke and a load applied to a key top;

8 is a view showing a case where the projection is connected to the frame and the link is formed by forming a hole in the frame of the second leg;

9 is a view showing a modification of the contact leaf spring as a second embodiment of the present invention;

Fig. 10 is an enlarged view of only the contact leaf spring and the saw blade in the second embodiment;

Fig. 11 is a view showing a case where a contact leaf spring is formed in parallel with a wing of a link as a third embodiment of the present invention.

12 is a diagram showing a modification of the hole for the second leg.

Explanation of symbols on the main parts of the drawings

1: key top

1A: Link fixing hook 1B: Link fixing groove

2: link

21: 2nd leg (inner leg) 22: 1st leg (outer leg)

2A: Return leaf spring 2B: Contact leaf spring

2C: Front fixing rod for key top 2D: Rear fixing rod for key top

2E: leg shaft projection 2F: leg shaft hole

2G: 1st leg hole 2H: contact protrusion

2I: 2nd leg hole

3: frame

3A: 2nd leg protrusion 3B: 1st leg protrusion

4: FPC (Flexible Printed Circuits)

The present invention to achieve the above object,

A key top that receives the pressure of the user's finger, a key that is lowered by the pressure of the key top to recognize a key operation, and when the pressure is released, a link that pushes the key top upwards, and is disposed on an upper surface of the keyboard frame so that In a key switch composed of FPC (Flexible Printed Circuits) for recognizing a key operation, the link includes a first leg and a first leg which are axially coupled to the frame and axially coupled to the second leg, and the first leg. A second leg freely engaged with the frame through the haptic and long hole, a return leaf spring for imparting a return force to the key top, and a contact leaf spring for pressure contact with the FPC. As the key top is pressed downward against the elastic force of the return leaf spring, the second leg and the frame are moved relative to each other through the long hole. During the riding movement, the relative movement stops at the end of the long hole, and if the pressure load continues to increase, the return spring surrenders and the pressure load sharply decreases to provide a click feeling. It provides a key switch characterized in that the hole is formed upright and the projections formed at the end of the second leg into the hole, respectively, and the FPC is located between the projection and the frame.

In addition, the hole is preferably located at the upper end.

In addition, it is preferable that a projection is formed on the lower surface of the key top, and the contact leaf spring is formed in a substantially stepped shape so that the contact leaf spring absorbs the pressure of the key top after the return leaf spring is yielded.

In addition, the contact leaf spring is preferably installed in parallel with the wing of the link is formed so that the wing portion of the link is thick.

It is also desirable to reduce the height of the keyswitch as a whole by allowing the links to be received into the grooves of the frame upon contraction.

(First embodiment)

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1 is a perspective view of a key switch according to the present invention, Figure 2 is a view showing a non-pressure state in which the key top is the original state, that is, the user does not apply pressure. 3 is a view showing a state in which the key top is lowered to the bottom end under pressure by a user's finger or the like.

As can be seen in Figures 1, 2, and 3, the key switch of the present invention comprises a key top 1, a link 2, an FPC 4, and a frame 3, which are from above to the bottom. It is arranged in the order of the key top 1, the link 2, the FPC 4, and the frame 3 from the surface of the keyboard to the lower side.

The key top 1 is located on the surface of the keyboard and so on, and has numbers (0, 1, 2, 3, ...), letters (a, b, c, ..., a, b, c, ..., ㅏ). , ㅑ, ...,!, @, #, ...) or other function (Esc, Ctrl, Alt, Home, PgUp, ...) is printed on the surface, that is, the user's finger It is a member that moves up and down by receiving pressure and descends under pressure and returns to its original state under the pressure of the link described below. It has a nearly rectangular roof shape and is usually made of plastic.

The link 2 is a member for guiding the vertical movement of the key top 1 and is compressed under the pressure of the key top 1 to provide a feeling of click by yielding the return leaf spring.

The FPC 4 is a flexible printed circuit, which is a circuit for recognizing a character or the like corresponding to each key top 1 by shorting its contact point due to the lowering of the key top 1, and being generally composed of a matrix circuit.

3 is a frame having a coupling mechanism that engages the link 2 as a frame, and supports the key 2 by supporting the link 2.

Hereinafter, each member of the coupling mechanism and the link 2 which interconnect each said member is demonstrated in detail.

On the back of the key top 1, a pair of link fixing hooks 1A and a pair of link fixing grooves 1B for engaging with the link 2 are formed.

The link fixing hook 1A is a hook-shaped hook, which is coupled with the front top fixing rod 2C for the keytop of the link 2 so that the front top fixing rod 2C for the keytop rotates counterclockwise as well as the link 2 ) Supports the sliding movement of the front fixing rod (2C) for the key top while moving downward and upward.

In addition, the link fixing groove 1B is a circular groove and is coupled to the key top rear fixing rod 2D of the link 2 to support the rotation of the key top rear fixing rod 2D in a clockwise direction.

In this embodiment, the link fixing hook 1A is located in front of the back of the key top 1, and the link fixing groove 1B is located in the back of the back of the key top 1, but the position of the link ( It can be properly adjusted according to the position of the fixed rod in 2). In addition, a hook or a groove may be formed in the link 2 and a fixing rod may be formed in the key top 1.

The frame 3 is formed with two pairs of protrusions for engaging with the link 2. That is, the pair of second leg protrusions 3A for engaging with the second leg hole 2I of the second leg 21 of the link 2 and the first leg 22 of the link 2 A pair of first leg projections 3B for engaging with the first leg hole 2G. These protrusions 3A and 3B support the second leg hole 2I and the first leg hole 2G in circular motion, sliding motion and circular motion, respectively.

It is also possible to form these protrusions in the link 2. In other words, a protrusion may be formed in the link 2 and a hole corresponding to the first leg hole 2G and the second leg hole 2I may be formed in the frame 3.

For example, as shown in Fig. 8, the second leg hole 3C is formed in the frame 3 upright, and the second leg protrusion 21A is formed in the second leg 21 to form the second leg hole 3C. The second leg protrusion 21A may be inserted into and coupled to the second leg protrusion 21A. In this case, since the FPC 4 is positioned between the second leg protrusion 21A and the frame 3, the FPC 4 is prevented from floating up by the second leg protrusion 21A and thus freely moves. It is prevented. Therefore, the contact point of the FPC (4) is always maintained in a constant position, so that the contact is accurately pressed by the falling of the link (2) is made an accurate key input.

In addition, in order to improve the feeling of click, it is necessary to increase the position of the link 2, and as described above, the second leg hole 3C is formed above the frame 3, and the second leg protrusion 21A is formed therein. By inserting the height of the entire link (2) is increased, thereby improving the feeling of clicking.

In addition, by placing the hole at the upper end, the peak load point can be pulled forward, thereby improving the click feeling. In addition, as shown in Fig. 12, when the opening is made upward, the position of the hole can be raised even further, so that the effect thereof can be maximized.

Next, with reference to FIG. 4, FIG. 1, the connection of the link 2, its structural member, and another member is demonstrated.

4 is a view showing the configuration of the link 2 in detail, (a) is a perspective view before connecting to another member, (b) is a plan view at the time of connection, and (c) is a side view at the time of connection.

The link 2 is an approximately quadrilateral structure and is integrally manufactured by mold injection molding.

2A is a pair of return leaf springs connected to both wings of the link 2. The return leaf spring 2A has an approximately strip-shaped arc shape, has elasticity, and applies a force upward when the link 2 is pressurized to be a source of force for returning the key top 1 to its original state.

In the present embodiment, the return leaf springs 2A are formed in pairs, but when the area of the key top is small, one may be formed as shown in Fig. 5A.

2B is a contact leaf spring that serves to lower when the link 2 contracts due to the pressure of the key top 1 to short-circuit the contact surface of the FPC 4, that is, the matrix switch. The contact leaf spring 2B has a substantially circular arc shape, and a contact projection 2H is formed to apply a certain contact force to the FPC 4 at a portion corresponding to the contact surface of the FPC 4. However, if the contact leaf spring 2B is curved in an arc shape, the contact projection 2H may not be formed.

In this embodiment, the contact leaf spring 2B is formed to be connected to only one wing, but may be formed to be connected to both wings as shown in FIG.

In addition, in this embodiment, the contact leaf spring (2B) is formed integrally with the other members of the link (2), but in order to increase the strength, first of all made of a material such as steel and assembled or inserted into the link (2) can do.

One wing of the link 2 is formed with a pair of second legs 21 inward. In this second leg 21, a long leg-shaped second leg hole 2I for connecting the second leg 21 to the frame 3 is formed. The second leg hole 2I is engaged with the second leg protrusion 3A of the frame 3 to cause the second leg protrusion 3A to perform a sliding movement and to stop the sliding movement, thereby providing a feeling of click. It also plays a role. That is, the second leg 21 and the frame 3 are axially coupled through the hole of the long hole, not a fixed axial coupling, but a coupling that can move the shaft in the present invention is a free axial coupling (自由 軸) It is defined as 支 結合).

Also, the second leg 21 is provided with a leg bearing hole 2F. This leg bearing hole 2F engages with the leg bearing protrusion 2E of the first leg 22 described later to support the scissors motion of the second leg 21 and the first leg 22.

On the other hand, a pair of first legs 22 are formed in the other wing of the link 2 inward. Each of these first legs 22 is formed to have elasticity so as to be open to the left and right in Fig. 4A.

The first leg 22 is formed with a leg bearing protrusion 2E for engaging with the leg bearing hole 2F of the second leg 21. The leg bearing protrusion 2E is coupled to the leg bearing hole 2F and is supported by the leg bearing hole 2F, and rotates according to the lowering motion of the key top 1 so that the second leg 21 and The first leg 22 makes the scissors motion.

Here, the leg bearing hole 2F and the leg bearing protrusion 2E can be interchanged with each other. That is, a protrusion may be formed in the second leg 21 and a hole may be formed in the first leg 22.

In addition, the first leg 22 is formed with a first leg hole 2G for engaging with the first leg protrusion 3B of the frame 3. This first leg hole 2G is engaged with the first leg protrusion 3B to cause the first leg 22 to rotate.

At one wing end of the link 2, a key top front fixing rod 2C for engaging with the link fixing hook 1A of the key top 1 is formed. The link 2 engages with the link fixing hook 1A through a groove formed in the front fixing rod 2C for the key top. In addition, a back fixing rod 2D for a key top for engaging with the link fixing groove 1B of the key top 1 is formed.

It is preferable that the constituent members of the link form grooves in the frame so that they are all accommodated in the grooves upon contraction. This will reduce the height of the entire keyswitch.

The assembly of the key switch comprised as mentioned above is demonstrated.

The first leg 22 of the injection-molded link 2 in the state as shown in FIG. 4 (a) is applied with a hand, a forceps, or the like, respectively, so that the leg bearing protrusion 2E is a leg bearing hole 2F. To be combined with 4B is a plan view of the coupled state, and FIG. 4C is a side view. In this state, it can be seen that the second leg 21 and the first leg 22 are combined in the shape of scissors.

The link (2) in the state that the legs are coupled in the shape of scissors is coupled to the frame (3) to which the FPC (4) is attached as shown in FIG. That is, the second leg hole 2I of the link 2 is coupled to the second leg protrusion 3A of the frame 3 and the first leg hole 2G of the first leg 22 is the first leg protrusion. To (3B).

Then, the hook fixing hook 1A of the key top 1 is hooked on the front fixing rod 2C for the key top, and the link fixing groove 1B is coupled to the rear fixing rod 2D for the key top of the link 2 1) to the link (2).

The key switch thus completed is shown in FIG.

The operation of the key switch will be described below.

When the key top 1 is pressed by the user's finger or the like in the state of FIG. 2, the key top 1 is lowered against the elastic force of the return leaf spring 2A of the link 2. At this time, the first leg 22 of the link 2 rotates counterclockwise about the first leg protrusion 3B of the frame 3. As a result, the leg bearing protrusion 2E of the first leg 22 is also lowered. On the other hand, the second leg 21 rotates clockwise about the leg bearing protrusion 2E, that is, in the shape of opening a pair of scissors. At this time, the leg bearing protrusion 2E is lowered so that the second leg hole ( 2I) is pushed to the lower left. Accordingly, the second leg protrusion 3A of the frame 3 moves relative to the upper right side along the inclined surface of the long leg-shaped second leg hole 2I (moved from the dotted line state in FIG. 6 to the solid line state).

The leaf spring 2A for return of the link 2 in the state in which the key top 1 is lowered in this way generates a force for raising the key top 1 while the circular arc shape is opened.

When the key top 1 is continuously pressed, the second leg protrusion 3A reaches the right end of the second leg hole 2I (solid line state in FIG. 6), and the movement of the second leg 21 is prevented and the second leg is blocked. (21) tries not to descend anymore.

Therefore, a large load is suddenly applied to the key top 1, and when the load exceeds the critical load, the second leaf 21 is returned to the plate spring (in the state where no further movement is possible by the second leg protrusion 3A). 2A) gives up the arc shape and yields a straight line yielding. In other words, the return leaf spring 2A does not generate a greater force to raise the key top 1. Therefore, the key top 1 takes a large force, and suddenly the key top 1 can be lowered even with a small pressure, so the user feels a click.

At the same time, the contact leaf spring 2B and the contact projection 2H pressurize and contact the FPC 4 to complete the key input.

On the other hand, when the load applied to the key top 1 is removed, the return leaf spring 2A restores the elastic force and raises the key top 1 to return to its original state.

7, the load on the key top 1 is demonstrated.

In the figure, the axis of abscissas represents the distance that the stroke, ie, the key top 1, is lowered. The vertical axis represents the pressure load on the key top 1. A region is the portion where the key top 1 starts to descend gradually under pressure in the initial state.

The area B is an area where the second leg protrusion 3A of the frame 3 starts to hinder the lowering motion of the link 2, that is, the lowering motion of the keytop 1, so as to continuously lower the keytop 1 suddenly. This is an area that requires a large load. In addition, the point where the boundary line and the curve of the region B and the region C meet is the critical pressure load point I described above.

The area C is a region in which the return leaf spring 2A gives up the elastic force and is in a straight line. As the lifting force of the return leaf spring 2A decreases rapidly, the pressure load also decreases abruptly so that the user feels a click.

In the area D, the key top 1 continues to descend after the yield point of the return plate spring 2A, and the contact plate spring 2B or the contact projection 2H presses and contacts the FPC 4 to complete the key input. It is an area.

When the load of the key top 1 is released after the area D, the return leaf spring 2A recovers the elastic force and raises the key top 1, thereby forming a hysteresis curve.

Second Embodiment

9 shows a second embodiment of the present invention. Fig. 10 is an enlarged view showing only the key top and the leaf spring 2B for contact in the second embodiment. The key switch of the present embodiment differs from the first embodiment in that the key top protrusion 11 is formed on the lower surface of the key top 1 and the contact leaf spring 2B has a substantially stepped shape. The other configuration is the same as that of the first embodiment, and the description thereof will be omitted.

The operation of the above embodiment will be described.

The pressure of the key top 1 is transmitted to the link 2 by the fall of the key top 1, and the contact leaf spring 2B falls. If the lowering continues, the key top protrusion 11 of the key top 1 presses the bent portion 2B 1 of the contact leaf spring 2 B, and the protrusion 2 B 2 starts to contact the contact of the FPC 4 of the frame 3. (See Fig. 10 (b)). Subsequently, when the key top 1 descends, the return leaf spring 2A of the link 2 surrenders and the key top 1 descends abruptly. At this time, the key top protrusion 11 of the key top 1 comes into contact with the bent portion 2B 1 of the contact leaf spring 2B to transmit the downward pressure. Since the contact leaf spring 2B has a substantially stepped shape, it absorbs the pressure of the key top protrusion 11, that is, the key top 1, while changing its shape (see Fig. 10 (c)). Therefore, the key top 1 descends relatively smoothly to reach the frame 3, and thus the key top 1 descends abruptly so that there is no noise generated by directly hitting the frame 3.

In addition, since the key top protrusion 11 has an effect of reinforcing the key top 1, there is an effect of providing a durable key switch.

(Third Embodiment)

11 shows only a link 2 portion of yet another embodiment of the key switch of the present invention. Other configurations are the same as those in the first embodiment, and the illustration and explanation thereof are omitted.

The key switch of the present embodiment is used for a long drain key used as a special key such as a space or an enter.

The link 2 used for such a key switch has a large area of the wing of the link 2, as shown in FIG. This is to ensure that the pressure of the key top 1 is evenly and reliably transmitted to the entire link 2. In other words, it replaces the existing link bar.

Moreover, it formed so that the direction of the contact leaf spring 2B might be parallel to a blade | wing. In order to secure the elastic force of the contact leaf spring (2B), the length of the contact leaf spring (2B) should be more than a certain length, in order to thicken the wings of the link (2) of the contact leaf spring (2B) You can only shorten the length. Therefore, the direction of the contact leaf spring 2B is formed by rotating 90 ° at the positions of the first and second embodiments.

Therefore, the wings of the link 2 can be thickened to reinforce the link 2 while sufficiently maintaining the elasticity of the contact leaf spring 2B.

As described above, the present invention can be produced inexpensively and simply by integrally forming the link by injection molding. In addition, there is an excellent effect that can be easily assembled to the frame by tightening the first leg inward.

In addition, a long hole is formed in the second leg, which is coupled to the projection of the frame to prevent the sliding movement of the hole by the projection, which requires a large load on the key top, and when the critical load is greater than or equal to the critical spring, the leaf spring for returning the link Yields and suddenly reduces the load, making you feel a click. That is, a simple structure, such as forming a hole in the back plate spring and a link or a frame, has an effect of realizing a click feeling.

In addition, by forming a hole for the second leg in the frame and inserting the protrusion formed in the second leg, the FPC is placed between the protrusion and the frame to prevent the FPC from moving so that the contact point is pressed accurately when the keytop descends. . In addition, the hole can be positioned at the upper end to bring the point of the peak load forward to improve the click feeling, and in particular, if the shape of the hole is opened in the upper position, the position becomes higher and the click feeling is maximized.

In addition, by forming projections on the lower surface of the key top and forming a contact plate spring in a substantially stepped shape, the contact plate spring absorbs the pressure of the key top after the return plate spring has surrendered. In addition, there is an effect to press the contact firmly.

In addition, by forming the contact leaf spring in parallel with the wing of the link, the length of the contact leaf spring is sufficiently secured, and at the same time, the wing is thickened, and thus, it can be applied to the drainage kiss sufficiently.

Claims (5)

A key top that receives the pressure of the user's finger, a key that is lowered by the pressure of the key top to recognize a key operation, and when the pressure is released, a link that pushes the key top upwards, and is disposed on an upper surface of the keyboard frame so that It consists of FPC (Flexible Printed Circuits) to recognize the key operation, The link comprises a pair of first legs that are axially coupled to the frame and axially coupled to the second leg, and are freely coupled to the frame through the long hole through which the first leg is axially coupled to the first leg. A pair of second legs to be combined; a return leaf spring for applying a return force to the key top; and a contact leaf spring for pressure contact with the FPC. As the key top is pressed downward against the elastic force of the return plate spring, the second leg and the frame make a relative sliding movement through the long hole, and then the relative motion at the end of the long hole stops. When the pressure load increases, the return spring yields and the pressure switch rapidly decreases, thereby providing a click feeling. Forming projections on the lower surface of the key top, The contact leaf spring is formed in a substantially stepped shape To allow the contact leaf spring to absorb the pressure of the key top after the return leaf spring has yielded. Key switch, characterized in that. The method of claim 1, Form a pair of holes in the frame and insert the projections formed at the ends of the second leg into the holes, FPC is located between the protrusion and the frame Key switch, characterized in that. The method of claim 1, The contact leaf spring is installed in parallel with the wing of the link The wing of the link is thick Key switch, characterized in that. The method of claim 1, The link is to be received all the way into the groove of the frame upon contraction. Key switch, characterized in that. The method of claim 1, At least one of the pair of holes is located in the upper end (上 端 部) and the opening (開口) towards the upper Key switch characterized by the above.