JP4424126B2 - Key switch structure - Google Patents

Description

  The present invention relates to a key switch used for a keyboard of a personal computer or the like.

(Constitution)
In recent years, with the spread of notebook personal computers, keyboards are required to be thin. FIG. 8 is a structural diagram of a conventional key switch adopted to meet the demand for thinning.

  The conventional key switch includes a key top 1, a first link member 2, a second link member 3, a cup rubber 4, a housing 5, a contact sheet 6 and a base plate 7. The key top 1 has a pair of rotation support portions 1r for rotatably supporting one end of the first link member 2, and a pair of one end of the second link member 3 for slidably moving in the horizontal direction in FIG. A slide support portion 1s is provided.

  The first link member 2 has a pair of legs, and is arranged at one end of the legs so that a first connecting rod inserted into the rotation support part 1r of the key top 1 connects the two legs. Similarly, a second connecting rod is disposed at the other end of the leg portion so as to connect the two leg portions, and is disposed at the position of the slide guide 5s of the housing 5.

  The second link member 3 has a pair of leg portions. A first support protrusion is slidably supported on the slide support portion 1s of the key top 1 at one end of the leg portion, and a second support member is provided at the other end. A second support protrusion is inserted into the rotation guide 5 r of the housing 5 at a distance equal to the distance between the connecting rods of the one link member 2. The first link 2 and the second link 3 have a structure in which the center is hollowed out so as not to interfere with a cup rubber 4 described later.

  The cup rubber 4 is an elastic member, and is disposed on the contact sheet 6 so that the upper part thereof is in contact with the back surface of the key top 1. The contact sheet 6 is arranged such that the movable contact 6a and the fixed contact 6b face each other with a predetermined gap. The base plate 7 is disposed below the above components and is fixed to the housing 5 with screws or the like.

(Operation)
In the conventional key switch configured as described above, when the key top 1 is pressed, the back surface of the key top 1 presses the upper part of the cup rubber 4 so that the cup rubber 4 is compressed and deformed, and the cup rubber. The contact pressing portion provided so as to protrude below 4 contacts the contact sheet 6 and presses it.

As a result, the contact sheet 6 bends, and the movable contact 6a disposed below the contact sheet 6 comes into contact with the opposed fixed contact 6b, thereby making an electrical connection and closing the switch. Thereafter, when the pressing of the key top 1 is released, each component returns to the original state by the restoring force of the cup rubber 4, and the contact sheet 6 that has been bent is also restored, so that the contact between the movable contact 6a and the fixed contact 6b is made. Once disconnected, the switch is open. (For example, refer to Patent Document 1).
Japanese Patent Application Laid-Open No. 11-339587

  Although the keyboard has been thinned as described above, in recent years, there has been a demand for a better press feeling, such as a longer stroke that increases the stroke when the key is pressed, along with a demand for a thinner keyboard. It is increasing.

  However, in the configuration of the conventional key switch, it is necessary to enlarge the cup rubber 4 in order to lengthen the stroke. If the cup rubber 4 is enlarged, the links 2 and 3 and the cup rubber 4 interfere with each other. It was difficult to realize a stroke.

The present invention adopts the following configuration in order to solve the above-described problems. Namely, the present invention provides a key top, with engaging respectively one end to the key top, arranged in the first and second link members engaged with each other, the inside of the first and second link members A first elastic member that is displaced when the key top is pressed, a contact sheet that is closed by being pressed by the first elastic member, and the first elastic member between the key top and the contact sheet. Ri Do and a second elastic member disposed to overlap with the member, the second elastic member has a first fixed part which is attached to the connecting portion of the first link member, said second link member The second fixing portion is slidably disposed on the connecting portion, and the spring is disposed between the key top and the first elastic member .

  According to the key switch structure of the present invention, since the first elastic member and the second elastic member are overlapped between the key top and the contact sheet, the stroke length can be increased without enlarging the first elastic member. Can be arbitrarily long.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the element which is common in drawing.

(Constitution)
FIG. 1 is a structural view showing a key switch of the embodiment, and FIG. 2 is an exploded perspective view showing the key switch of the embodiment.

  The key switch according to the embodiment includes a key top 1, a first link member 2, a second link member 3, a cup rubber 4, a housing 5, a contact sheet 6, a base plate 7, and a spring portion 8.

  The key top 1 has rotation support portions 1a and 1b that rotatably support one end of the first link member 2, and a slide support portion that supports one end of the second link member 3 so as to be slidable in the horizontal direction in FIG. 1c and 1d are provided.

  As shown in the figure, the spring portion 8 is formed by punching and bending an aluminum plate, for example, and providing fixing portions 8a and 8b and a spring 8c. And it arrange | positions on the below-mentioned 1st connection rod 2c of the 1st link member 2 with the fixing | fixed part 8a, and arrange | positions on the below-mentioned connection part 3i of the 2nd link member 3 with the other fixing | fixed part 8b. Arranged between the cup rubbers 4. The spring portion 8 does not need to be an aluminum material, and may be a steel plate or the like, or may be formed of a plastic resin or the like. Alternatively, a coil spring or a spiral spring may be used.

  Since the connecting portion 3i slides in the horizontal direction when the key is pressed, the fixing portion 8b is bent with a space corresponding to the sliding portion, but no space is provided, and either or both of the fixing portions 8a and 8b are flexible. It is good also as a structure which makes it material and expands and contracts according to the slide of the connection part 3i.

  Here, the spring portion 8 is displaced as shown in FIG. 4 when a load is applied from the key top 1 side as shown in FIG. That is, since the spring part is displaced linearly and reversibly with respect to the load, the spring part is changed as shown in FIG. 4A, and the spring 8c is displaced to the upper position of the spring part to reach the point a in the figure (in this example 1 mm). ) And no further displacement.

  On the other hand, the cup rubber 4 is shaped so as to have a reverse S-shaped characteristic as shown in FIG. 4B in order to give a feeling of pressing the key. When it is displaced and reaches the position b (3 mm in this example) in the figure, it is hardly displaced further. Since it is made of an elastic material, there is a slight hysteresis between the displacement at the time of pressing and the displacement at the time of opening, and the pressing characteristics as shown in the figure are obtained.

  When these spring portions 8 and the cup rubber 4 are superposed, the displacement characteristics are combined, as shown in FIG. 4C, and displaced up to point b in the figure (1 mm + 3 mm = 4 mm in this example). As a result, the stroke length can be increased from 3 mm to 4 mm while maintaining the touch of the key. In addition, the said length is only an example and it cannot be overemphasized that it is not limited to this length.

  In the example of FIG. 4, the displacement limit position a point of the spring portion 8 and the displacement limit position b point of the cup rubber 4 are substantially matched so that the displacement characteristics of the cup rubber 4 do not change so much. However, as shown in FIG. 5A, the spring constant of the spring portion (that is, displacement / loading, but for the sake of convenience, hereinafter referred to as “elastic modulus”) is lowered and before the displacement limit position b of the cup rubber 4 is reached. Alternatively, the spring may reach the displacement limit position a of the spring portion, or after increasing the elastic modulus of the spring portion and reaching the displacement limit position b of the cup rubber 4 as shown in FIG. You may make it reach the displacement limit position a point of a part.

  In the case of FIG. 5 (a), the key stroke can be lengthened while maintaining the displacement characteristic of the cup rubber 4, whereas in the case of FIG. 5 (b), the displacement characteristic of the cup rubber 4 is affected. The elastic force (displacement / weighting) can be maintained.

  1 and 2 again, the first link member 2 has a pair of leg portions 2a and 2b. One end of each of the leg portions 2a and 2b is connected to the rotation support portions 1a and 1b of the key top 1. The first connecting rod 2c to be inserted is disposed so as to connect the two leg portions 2a and 2b. Similarly, the second connecting rod 2d is connected to the two leg portions 2a at the other end of the leg portions 2a and 2b. 2b are connected to each other.

  Further, each of the two leg portions 2a, 2b is located on a line connecting the first connecting rod 2c and the second connecting rod 2d, and is equidistant from each connecting rod 2c, 2d. The rotary shafts 2e and 2f are provided.

  The second link member 3 has a pair of leg portions 3a and 3b, and a first support protrusion that is slidably supported by the slide support portions 1c and 1d of the key top 1 at one end of the leg portions 3a and 3b. 3c and 3d are arranged at the other end with second support protrusions 3e and 3f at a distance equal to the distance between the connecting rods 2c and 2d of the first link member 2.

  Further, the rotation hole 3g, on the line connecting the first support protrusions 3c, 3d and the second support protrusions 3e, 3f and at the same distance to each of the support protrusions 3c, 3d; 3e, 3f, 3h is provided. Further, the two leg portions 3a and 3b are connected by a connecting portion 3i further on the tip side than the first support protrusions 3c and 3d.

  The first link member 2 and the second link member 3 are rotatably engaged by fitting the rotation shafts 2 e and 2 f of the first link member 2 into the rotation holes 3 g and 3 h of the second link member 3. ing. The housing 5 is provided with slide guides 5a and 5b for supporting the second connecting rod 2d of the first link member 2 so as to be slidable in the horizontal direction in FIG. Rotation guides 5c and 5d are provided for rotatably supporting the protrusions 3e and 3f. Further, a guide wall 5 e for fixing the cup rubber 4 is disposed in the housing 5 so as to surround the outer periphery of the cup rubber 4.

  The cup rubber 4 is an elastic member, and is disposed on the contact sheet 6 so that the upper portion thereof is in contact with the lower surface of the spring 8 c of the spring portion 8. The contact sheet 6 is arranged such that the movable contact 6a and the fixed contact 6b face each other with a predetermined gap. The base plate 7 is disposed below the above components and is fixed to the housing 5 with screws or the like.

(Operation)
FIG. 6 is an explanatory diagram showing the pressed state of the example key switch. The operation of this embodiment will be described below with reference to this figure. As the key top 1 is pressed and moved downward, the first link member 2 uses the first connecting rod 2c rotatably supported by the rotation support portions 1a and 1b of the key top 1 as the center of rotation. 1 (FIG. 6), the second connecting rod 2d on the other end side of the first link member 2 rotates in the clockwise direction along the slide guides 5a and 5b of the housing 5 in FIG. 1 (FIG. 6). Slides horizontally to the left.

  In the second link member 3, the rotation shafts 2e and 2f of the first link member 2 are rotatably fitted in the rotation holes 3g and 3h of the second link member 3, so that the operation of the first link member 2 is performed. Accordingly, the first support protrusions 3 c and 3 d of the second link member 3 slide in the horizontal left direction in FIG. 1 (FIG. 6) along the slide support portions 1 c and 1 d of the key top 1, and the rotation guide 5 c of the housing 5. The second support protrusions 3e and 3f rotatably supported by 5d rotate about the counterclockwise direction in FIG. 1 (FIG. 6).

  As a result, the key top 1 moves downward in FIG. 1 (FIG. 6) while keeping parallel to the housing 5. As the key top 1 moves downward, the back surface of the key top 1 presses the upper part of the spring part 8 and the spring part 8 presses the upper part of the cup rubber 4, so according to the displacement characteristics shown in FIG. The contact pressing portion 4a that is formed inside the cup rubber 4 and protrudes downward is brought into contact with and pressed against the contact sheet 6 so that the movable contact 6a and the fixed contact 6b come into contact with each other. The connection is made and the switch is closed.

  Then, as shown in FIG. 6, the first link member 2 and the second link member 3 do not overlap and rotate to a position that is substantially horizontal with respect to the housing 5. At this time, the spring portion 8 also gradually becomes horizontal when the key top 1 is pressed, and is displaced to a substantially horizontal position as shown in FIG.

  When the pressing of the key top 1 is released, each component returns to the original state as shown in FIG. 1 due to the restoring force of the spring portion 8 and the cup rubber 4, and the movable contact 6a and the fixed contact 6b of the contact sheet 6 are also restored. The switch is opened because the electrical contact is disconnected.

  As described above, since the spring portion 8 and the cup rubber 4 are superposed, the stroke length can be arbitrarily increased without increasing the cup rubber 4.

  A key switch structure that converts the pressing operation on the key top 1 into a rotational motion and a horizontal sliding motion by using the first link member 2 and the second link member 3, and the spring portion 8 and the cup rubber 4 are overlapped. With the combined configuration, the key top 1 can always be positioned parallel to the housing 5, and a good pressing feeling can be obtained when any part of the key top 1 is pressed. Can be maintained.

  And it is comprised so that both may not overlap in a perpendicular direction (height direction) so that the 1st link member 2 may be stored in the 2nd link member 3, and the structure which piled up the spring part 8 and the cup rubber 4 Therefore, not only a smooth operation can be realized while ensuring a sufficient stroke of the key switch, but also the effect that the key switch can be configured low can be maintained.

<< Other modifications >>
In the above description, the key switch using the first link member 2 and the second link member 3 has been described as a configuration in which the spring portion 8 and the cup rubber 4 are overlapped. In the key switch having a simple configuration in which the cup rubber 4 is disposed below the key top 1 without using the second link member 3, the spring portion 8 and the cup rubber 4 may be superposed on the lower surface of the key top. .

  In the above description, the second elastic member disposed between the key top 1 and the cup rubber 4 has been described as a spring-like member such as the spring portion 8, but the second elastic member is somewhat non-linearly displaced. The elastic member may be made of an elastic member such as a rubber material.

  In the above description, the spring portion 8 is arranged on the cup rubber 4. However, as shown in FIG. 7, the vertical relationship between the cup rubber 4 and the spring portion 8 is reversed, and the cup rubber 4 It is good also as a structure which arrange | positions the cup rubber 4 on spring part 8 'which provided the hole 8d in the center part so that the contact pressing part 4a can press the movable contact 6a.

It is a structural diagram of the key switch of the embodiment. It is a disassembled perspective view of the key switch of an Example. It is explanatory drawing of the pressing characteristic of the key switch of an Example. It is a pressing characteristic of the key switch of an Example. It is the pressing characteristic of the key switch of another Example. This is a pressed state of the key switch of the embodiment. It is a structure figure of the key switch of another Example. It is a structural diagram of a conventional key switch.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Key top 1a, 1b, 1r Rotation support part 1c, 1d, 1s Slide support part 2 1st link member 2a, 2b Leg part 2c 1st connection rod 2d 2nd connection rod 2e, 2f Rotating shaft 3 2nd link member 3a 3b Leg portion 3c, 3d First support protrusion 3e, 3f Second support protrusion 3g, 3h Rotating hole 3i Connecting portion 4 Elastic member 4a Contact pressing portion 5 Housing 5a, 5b, 5s Slide guide 5c, 5d, 5r Rotating guide 5e Guide wall 6 Contact sheet 7 Base plate 8 Spring portion 8a, 8b Fixed portion 8c Spring

Claims (1)

Key tops,
First and second link members engaged with each other at one end of the key top and engaged with each other;
A first elastic member disposed inside the first and second link members and displaced by pressing a key top;
A contact sheet that is closed by being pressed by the first elastic member;
Ri Do and a second elastic member disposed to overlap with the first elastic member between the key top and the contact sheet,
The second elastic member includes a first fixing portion mounted on the connecting portion of the first link member, and a second fixing portion slidably disposed on the connecting portion of the second link member. And a spring disposed between the key top and the first elastic member .

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