JP5618868B2 - Key switch device and keyboard - Google Patents

Description

  The present invention relates to a key switch device that is operated to make a keystroke, and more particularly to a key switch device that is used in a keyboard that is an input device of an electronic device. The present invention further relates to a keyboard provided with a plurality of such key switch devices.

  Conventionally, in the field of portable electronic devices such as notebook personal computers, in order to improve the portability of devices, various technologies have been proposed for realizing a thin (low profile) device housing including a keyboard. ing. In particular, when thinning a keyboard having a plurality of key switch devices that are operated by keystroke, the key switch is maintained while maintaining the stroke amount of the key switch device at a predetermined amount in order to ensure operability above a certain level. It is desired to reduce the overall height when the device is not operated and when the device is pushed down.

  As a key switch device that can be used for this kind of low-profile keyboard, for example, Patent Document 1 discloses a base, a key top disposed on the base, and a key top that guides and supports the base in the ascending / descending direction on the base. Disclosed is a key switch device including a pair of link members and a sheet-like switch (herein referred to as a membrane switch sheet) that opens and closes a contact of an electric circuit in accordance with a lifting operation of the key top. Here, the pair of link members are of a so-called gear link type, combined in an inverted V shape in side view, meshed with each other in a gear shape and supported rotatably on the key top, and the like. Engageably engages the base at the end.

  Patent Document 2 discloses a gear link type link member having a V-shaped side view, and a frame member having a bearing portion that rotatably receives and supports the respective rotation shaft portions of the pair of link members. There is disclosed a key switch device comprising: Further, Patent Document 3 discloses a key switch in which a link member is in a pantograph format.

  The key tops pivot with respect to the base by the link members swinging in opposite directions around one end and sliding in the substantially horizontal direction along the base. It can be translated while maintaining a predetermined posture in a substantially vertical direction.

  Further, when the key top size is large, the key top lacks stability only with the above-described link mechanism, and for example, when the end of the key top is pressed, the key may be tilted and operate. . Therefore, in order to prevent this, a member called a stabilizer may be arranged to connect the key top and the base member. For example, Patent Document 4 discloses a key switch 10 provided with a stabilizer 12 whose upper end is pivotally attached to the lower portion of the tip 11b of the key top 11 and whose lower end is pivotally supported by the substrate-side rotation fulcrums 18a and 18a. Has been.

Japanese Patent Laid-Open No. 11-3628 JP 2009-73621 A Japanese Utility Model Publication No. 5-66832 JP 2005-93129 A

  In recent key switch devices, in order to reduce the thickness of a keyboard or the like on which the key switch device is provided, it is desired to make the height of the key top as low as possible (less height) at the time of no load. In order to ensure operability, it is desired that the stroke of the key top is a predetermined amount or more (high stroke). In order to realize both the reduction in the height and the increase in the stroke, it becomes a problem how to accommodate the link member and the stabilizer member within the thickness of the key top when the key top is pushed down most. In particular, the stabilizer member may interfere with a membrane sheet provided between the base member and the key top, and a sufficient stroke amount may not be obtained.

  Accordingly, the present invention provides a key switch device having a stabilizer member, a key switch device having a configuration that realizes both a low switch operation and a high stroke, and a keyboard including a plurality of such key switch devices. The purpose is to provide.

In order to achieve the above-mentioned object, the invention according to claim 1 is characterized in that a base, a key top disposed above the base, and the key top are guided and supported above the base in the ascending / descending direction. A pair of link members, and a switch mechanism that opens and closes the contact portion of the electric circuit in response to the raising and lowering operation of the key top, and each of the pair of link members is one of the base and the key top A sliding engagement portion that has a sliding portion that is slidably connected to one side, and that the base or key top that is the connection partner of the sliding portion slidably engages the sliding portion. A key switch device that is pivotally supported by the key top and is pivotally and slidably engaged with the base so that the key top is maintained in a substantially horizontal position. An auxiliary star for moving The stabilizer member further includes a first portion that extends linearly from the key top side, and one end connected to an end portion of the first portion opposite to the key top side, and the first portion; And a second portion extending in a different direction, and the first portion is formed on a surface of a membrane switch sheet of the switch mechanism disposed on the upper surface of the base when the key top is pushed down to a lower limit position. When the key top is pushed down to the lower limit position, the opposite end of the second portion on the side opposite to the top of the key is the anti-key of the first portion in the ascending / descending direction of the key top. positioned lower by the thickness of the maximum the membrane switch sheet from the top-side end portion, the end portion of the counter key top side of the first portion is positioned between the key top and the base The membrane switch sheet, when the key top is located at the lower limit position, having a first relief holes in which the stabilizer member is formed so as not to interfere with the membrane switch sheet to provide a key switch.

According to a second aspect of the present invention, in the key switch device according to the first aspect, when the key top is pushed down to the lower limit position, the end portion on the opposite side of the key top of the second portion is A key switch device is provided that is positioned below a distance equal to the thickness of the membrane switch sheet from an end portion on the side opposite to the key top of the first portion in the ascending and descending direction.

According to a third aspect of the present invention, in the key switch device according to the first or second aspect , the membrane switch sheet is formed on the key top when the key top is located at a lower limit position. There is provided a key switch device further comprising a second escape hole formed so that a pivot shaft for supporting the pivot shaft does not interfere with the membrane switch sheet.

According to a fourth aspect of the present invention, in the key switch device according to any one of the first to third aspects, the base is engaged with a base side connected to the other end of the second portion of the stabilizer member. A stabilizer engaging portion that engages with the base side engaging portion so that the portion is rotatable and slidable with respect to the base, and the stabilizer engaging portion is a metal plate constituting the base; There is provided a key switch device which is convex on the upper surface side of the base by drawing and has a flat portion parallel to the upper surface of the base at least within a sliding range of the base side engaging portion with respect to the base.

According to a fifth aspect of the present invention, in the key switch device according to any one of the first to third aspects, the base is engaged with the base side connected to the other end of the second portion of the stabilizer member. A stabilizer engaging portion that engages with the base side engaging portion so that the portion is rotatable and slidable with respect to the base, and the stabilizer engaging portion is a metal plate constituting the base; Provided is a key switch device that is convex to the upper surface side of the base by cutting and bending and has a flat portion parallel to the upper surface of the base at least within a sliding range of the base side engaging portion with respect to the base To do.

A sixth aspect of the present invention provides a keyboard including a plurality of key switch devices according to any one of the first to fifth aspects.

  According to the present invention, in a key switch device having a link member and a stabilizer member for guiding and supporting a key top to be keyed, it is possible to reduce the key switch device without applying special processing or inconvenient load when manufacturing the constituent members. It is possible to realize height reduction and high stroke.

  By providing a relief hole in the membrane switch sheet, it is possible to further ensure the stroke of the key top for the thickness of the membrane switch sheet.

  By forming the stabilizer engaging portion of the base by drawing, cutting (cutting), and bending, the thickness of the top surface of the stabilizer engaging portion can be made equal to the thickness of the metal plate constituting the base. Further thinning is achieved.

1 is an exploded perspective view showing a schematic configuration of a key switch device according to a first embodiment of the present invention. It is a perspective view which shows the frame member and link member of the key switch apparatus of FIG. It is a perspective view which shows the key top and stabilizer member of the key switch apparatus of FIG. It is the upper side figure and side view of a stabilizer member. (A) It is a sectional side view which shows the positional relationship of each member when a keytop exists in an upper limit position, (b) It is a sectional side view which shows the positional relationship of each member when a keytop exists in a minimum position. It is a three-plane figure which shows one structural example of the stabilizer engaging part of a base member. It is a three-view figure which shows the other structural example of the stabilizer engaging part of a base member.

  FIG. 1 is a perspective view showing a configuration example of a key switch device 10 according to a preferred embodiment of the present invention. The key switch device 10 includes a plate-like base 12, a key top 14 disposed above the base 12, and a pair of link members 16 that interlock with each other and guide and support the key top 14 in the up and down direction above the base 12. And a stabilizer member 18 (described later) configured to hold the key top 14 horizontally throughout the entire vertical movement (lifting / lowering) stroke, and a contact portion of the electric circuit corresponding to the lifting / lowering operation of the key top 14 (see FIG. Switch mechanism 20 for opening and closing (not shown). A keyboard can be configured by arranging a plurality of such key switch devices 10. The switch mechanism 20 is disposed between the key top 14 and the membrane switch sheet 22, and the membrane switch sheet 22 that is placed on the base 12 while supporting the contact portion at a position corresponding to the key top 14. In addition, it has a rubber dome-like actuating member 24 in the illustrated example, which acts to close the contact portion as the key top 14 is lowered.

  Further, as clearly shown in FIG. 2, the key switch device 10 is fixedly attached to the upper surface 26 of the base 12 and rotatably receives the respective rotary shaft portions 28 (described later) of the pair of link members 16. And a frame member 32 having a substantially rectangular shape in plan view. The base 12 is a flat plate-like rigid member such as an independent metal thin plate made of, for example, a sheet metal material, and the membrane switch sheet 22 and the operation member 24 are statically supported by the upper surface 26 thereof. In addition, in embodiment of this invention, things other than the stabilizer member 18 mentioned later and the structure relevant to this may be the same as that of the conventional thing as described in patent document 2. FIG.

  The key top 14 is, for example, a substantially rectangular flat plate-shaped or dish-shaped member made of an integrally molded product of a resin material, and as shown clearly in FIG. 3, the inner surface on the opposite side of the operation surface 14 a on which the key is pressed. In FIG. 14b, two sets of link shaft support portions 34 having the same structure are formed side by side in the link sliding direction (generally the left-right direction in FIG. 3). The two link shaft support portions 34 constituting each set are in a substantially central region of the inner surface 14b of the key top 14 in the link sliding direction, and are separated from each other by a distance capable of inserting the second end region of each link member 16 therebetween. Placed apart. Accordingly, each of the pair of link members 16 is rotatably connected to each link shaft support portion 34 by a rotation portion provided in the second end region thereof.

  The pair of link members 16 have the same shape and size as each other, and are combined so that they can be connected to each other in a gear shape so as to exhibit a V-shape in a side view. Each of the pair of link members 16 is made of, for example, an integrally molded product of a resin material, and integrally includes a pair of arm portions 36 that extend substantially parallel to each other and a body portion 38 that connects the arm portions to each other. In the illustrated embodiment, in each link member 16, the end region of both arm portions 36 adjacent to the body portion 38 is defined as the first end region of the link member 16, and is extended from the body portion 38 in the same direction. The end region of both arms 36 is defined as the second end region of the link member 16.

  In the first end region of each link member 16, a pair of sliding shaft portions 42 constituting a sliding portion project coaxially from the outer surfaces of the arm portions 36 that are separated from each other to the opposite side of the body portion 38. Established. In addition, in the second end region of each link member 16, a pair of rotating shaft portions 28 constituting the rotating portion are coaxially formed from the inner side surfaces of both arm portions 36 to the side opposite to the sliding shaft portion 42. Projected. Further, one arm portion of each link member 16 is provided with one tooth on the distal end surface of the second end region adjacent to the rotation shaft portion 28, and the rotation shaft portion 28 is provided on the other arm portion. Two teeth are provided on the distal end surface of the second end region proximate to.

  Each link member 16 has a pair of pivot shafts 28 in the first end region rotatably fitted in corresponding bearing portions 30 provided in the frame member 32, and a pair of sliding shafts in the second end region. The portion 42 is slidably fitted into a corresponding shaft support portion 34 provided on the key top 14, and is disposed between the base 12 and the key top 14. At this time, the pair of link members 16 are engaged with each other by one tooth of each arm part and two teeth of each other arm part, thereby forming both The rotation shafts 28 of the arm portions can be rotated in conjunction with each other around the respective rotation axes defined by the rotation shaft portions 28.

  The actuating member 24 is a dome-shaped member integrally formed from a rubber material, and is disposed between the key top 14 and the membrane switch sheet 22 with the dome top portion facing the key top 14 side. The actuating member 24 is disposed inside the frame member 32 at the lower end of the dome opening and is fixed to the membrane switch sheet 22. The actuating member 24 is arranged such that the top of the dome is spaced upward from the membrane switch sheet 22 when there is no load. A protrusion (not shown) is formed on the inner surface of the top of the dome of the actuating member 24 so as to align with the contact portion of the membrane switch sheet 22 and press and close the contact portion when the key top 14 is lowered. The

  In the key switch device 10, when no external force is applied to the key top 14, the actuating member 24 biases and supports the key top 14 at the stroke upper limit position separated vertically upward from the base 12 at the top of the dome. At this time, the membrane switch sheet 22 is in a state where the contact portion is open. Further, when the key top 14 is pushed down by a keystroke operation, the actuating member 24 is elastically deformed as the key top 14 is lowered, and applies an upward elastic biasing force (initial position return force) to the key top 14. At the same time, when the key top 14 reaches the stroke lower limit position, the membrane switch sheet 22 is pressed from the outside by the protrusion on the inner surface of the dome top portion to close the contact portion. When the pressing force to the key top 14 is released, the operating member 24 is elastically restored to return the key top 14 to the upper limit position, and the membrane switch sheet 22 is restored to open the contact portion. Thus, the operation member 24 also functions as an urging member that exerts an elastic urging force that returns the key top 14 to the upper limit position of the lifting / lowering operation.

  In the key top 14, the pair of link members 16 swings in opposite directions in synchronization with the rotation axis of each first end region, and each second end region is guided by the corresponding guide portion 34. By sliding downward in a substantially horizontal direction, the base 12 is translated in a substantially vertical direction. Here, when the key top 14 has a relatively large dimension in the sliding direction of the second end region (generally in the left-right direction in FIG. 1) as in the illustrated example, the operation surface 14a of the key top 14 is kept horizontal over the entire stroke. In order to do so, the above-described stabilizer member 18 is used.

  The stabilizer member 18 is composed of a substantially rectangular frame-shaped member in which one of the substantially U-shape or the long side is cut out in a plan view as shown in FIG. 4, and includes a substantially straight long side portion 44 and a long side portion. And a pair of short side portions 46 which are connected at one end so as to be orthogonal to the respective ends of 44 and extend in parallel to each other. As an example, the stabilizer member 18 may be produced by bending a wire member made of a metal material having a wire diameter of 0.5 mm to 1 mm, or may be produced by molding a resin material. As shown in FIG. 3, the long side portion 44 of the stabilizer member 18 is pivotally supported by two stabilizer shaft support portions 48 provided on the back surface 14 b of the key top 14 at both ends, and at least the key top 14 is moved up and down. It can be rotated within an angular range determined according to the stroke.

  The stabilizer member 18 has one end connected so as to be orthogonal to the other end of each of the pair of short side portions 46, and a base side engaging portion 50 extending a predetermined length in a direction substantially the same as the extending direction of the long side portion 44. As shown in FIG. 1 or FIG. 5 to be described later, the base side engaging portion 50 is rotatable with respect to the base 12 by a stabilizer engaging portion 52 formed on the base 12 and is linked to the link member 16. Slidably engages with the base 12 in a direction substantially perpendicular to the sliding direction of the second end region. With the stabilizer member 18 and the configuration related thereto, the operation surface 14a of the key top 14 can stably maintain a horizontal state over the entire vertical movement stroke.

  In the present invention, as shown in FIGS. 4 and 5, each of the pair of short side portions 46 of the stabilizer member 18 is not a simple linear member but has at least one bent portion 46a. . Specifically, each of the pair of short side portions 46 includes a first portion 46b extending substantially linearly from a connection end to the long side member 44 to the bent portion 46a, and a base side engaging portion 50 from the bent portion 46a. The second portion 46c extends substantially linearly to the connection end, and is configured as a member having a substantially “<” shape as a whole.

  Next, the operation of the stabilizer member 18 will be described. As shown in FIG. 5 (a), when the key top 14 is in its stroke upper limit position, the action of the stabilizer member 18 is substantially equivalent to that of the conventional stabilizer, but as shown in FIG. 5 (b), the stroke lower limit. When in position, the first portion 46b of the short side portion 46 extends on the membrane switch sheet 22 in parallel with the surface direction, while the second portion 46c of the short side portion 46 is the base side engaging portion. The bent portion 46a extends in a slightly different direction from the first portion 46b so that 50 engages with the stabilizer engaging portion 52 of the base 12 without rattling in the vertical direction. Therefore, as shown in FIG. 1 and FIG. 5, the escape hole 54 is formed in the membrane switch sheet 22 so that the membrane switch sheet 22 does not interfere with the second portion 46 c and the base side engaging portion 50. In the lower limit position shown in FIG. 5B, the stroke of the key top 14 corresponding to the thickness of the membrane switch sheet 22 can be further secured, and the lower end portion of the key top 14 is brought into contact with the membrane switch sheet 22. You can also. Here, as shown in FIGS. 1 and 5, the portion of the membrane switch sheet 22 that is close to the stabilizer shaft support portion 48 formed on the lower surface of the key top 14 at the lower limit position also interferes with the stabilizer shaft support portion 48. It is preferable to form a relief hole 56 for avoiding the above.

  In the illustrated example, the second portion 46c of the short side portion 46 of the stabilizer member 18 is a substantially linear member, but the lower limit position shown in FIG. 5B, that is, the first portion 46b extends in the horizontal direction. At the time (when extending on the membrane switch sheet), the end of the second portion 46c opposite to the key top side, that is, the base-side engaging portion 50 is moved in the vertical direction of the key top (perpendicular to the membrane switch sheet surface). Direction) from the opposite end (bent portion 46a) of the first portion 46b toward the maximum thickness of the membrane switch sheet 22 (preferably a distance equal to the thickness of the membrane switch sheet 22) downward (pressing down the key top) The second portion 46c may have other shapes, such as a smooth curved member as a whole, as long as it is displaced in the direction).

  As described above, according to the present invention, between the short side portion 46 of the stabilizer member 18 on the side connected to the key top 14 (connected to the long side portion 44) and the bent portion 46a. Since the linear first portion 46b extending in the direction extends in a state parallel to the membrane switch sheet (usually in a horizontal state) at the stroke lower limit position, the space between the key top 14 and the membrane switch sheet 22 can be effectively utilized ( If limited, the vertical distance between the key top 14 and the membrane switch sheet 22 in the side cross section shown in FIG. 5B corresponds to the thickness (wire diameter) of the first portion 46b). Therefore, as compared with the prior art, more key top strokes can be secured by the thickness of the membrane switch sheet 22, which contributes to the realization of at least one of lowering the key switch device and increasing the stroke.

  Even if the short side portion is a straight member having no bent portion, the key top can be formed by cutting out all of the relief holes 54 and 56 in FIG. 1 to provide a large relief hole of the membrane switch sheet 22. As for the stroke, it is possible to obtain the same effect as the present invention. However, since various circuit boards are formed on the membrane switch sheet 22, the effective area is preferably as large as possible, and it is not a good idea to provide a large relief hole as described above. On the other hand, according to the present invention, with respect to the stabilizer member 18, the stabilizer shaft support 48, the second portion 46c of the stabilizer member 18 and the relief holes 54 and 56 for the base side engaging portion 50 may be provided. The effective area of many membrane switch sheets 22 can be ensured.

  Further, from the viewpoint of making the effective area of the membrane switch sheet 22 as wide as possible (making the area of the escape hole as small as possible), the length of the first portion 46b is preferably as long as possible. For example, as shown in FIG. 46b and second portion 46c have a length ratio of approximately 2: 1, 1: 1, 3: 1, 4: 1, 5: 1, 10: 1, 20: 1 or a ratio thereof. Intermediate values of can be applied.

  Next, with reference to FIG.6 and FIG.7, the suitable structure of the stabilizer engaging part 52 engaged with the base side engaging part 50 of the stabilizer member 18 formed in the base 12 is demonstrated. The stabilizer engaging portion 52 is required to have a certain strength in order to hold the base-side engaging portion 50 of the stabilizer member 18 so as to be slidable and rotatable, while in the height direction (the vertical movement of the key top 14). For (direction), it is desirable to have a dimension as small as possible.

  Therefore, in the form shown in FIG. 6, the stabilizer engaging portion 52 is formed by drawing the base 12. The stabilizer engaging portion 52 is formed so as to be convex on the upper surface side by drawing the base 12, and in detail, a cross section in the same direction as the radial cross section of the base side engaging portion 50 of the stabilizer member 18 (A -A cross-section) has a substantially trapezoidal shape having an upper side 52a and a lower side 52b that are parallel to each other, and the vertical (shortest) distance between the upper side 52a and the lower side 52b is substantially equal to the diameter of the base side engaging portion 50. To be equal. In this way, the thickness of the upper side 52a is the same as the plate thickness of the base 12 and contributes to the reduction in thickness, and the base-side engaging portion 50 is flush with the upper surface 26 of the base 12 (see FIG. 1). Can slide along. The stabilizer engaging portion 52 may not have a trapezoidal shape, but for the smooth operation of the base side engaging portion 50, at least within the sliding range of the base side engaging portion 50 with respect to the base 12, It is preferable to have an upper side portion that is parallel to and flat with the upper portion.

  FIG. 7 shows another embodiment of the stabilizer engaging portion, in which the stabilizer engaging portion 52 ′ is formed by raising the base 12. Specifically, a part of the base 12 is cut or cut (in a U-shape) to form a substantially rectangular tab-shaped portion, and the tab-shaped portion is bent up to form the standing wall portion 52a ′. Further, the front end portion of the standing wall portion 52a ′ is bent horizontally (in parallel with the portion other than the stabilizer engaging portion 52 ′ of the base 12) to form the top surface portion 52b ′. Further, an opening 52c ′ is provided in 52a ′, and the base side engaging portion 50 of the stabilizer member 18 is rotated and slid along the surface of the base 12 in a state where it is inserted into the opening 52c ′. Make it possible. The opening 52c ′ has a size corresponding to at least the sliding range of the base side engaging portion 50 with respect to the base 12, and for the smooth operation of the base side engaging portion 50, the top surface portion 52c ′ has at least the base. In the sliding range of the base-side engaging portion 50 with respect to 12, it is preferable that the upper surface of the base 12 is parallel and flat. Further, in the cross section in the same direction as the radial cross section (A′-A ′ arrow) of the base side engaging portion 50 of the stabilizer member 18, other than the top surface portion 52 b ′ parallel to each other and the stabilizer engaging portion 52 ′ of the base 12. The distance in the vertical direction (shortest) between the base-side engaging portion 50 and the base-side engaging portion 50 is made substantially equal. Even with such a configuration, the thickness of the top surface portion 52b 'is the same as the plate thickness of the base 12 and contributes to the reduction in thickness. It can slide along the same height surface.

  In the illustrated example, the standing wall 52 a ′ is a member that is substantially perpendicular to the surface of the base 12 other than the stabilizer engaging portion 52 ′, but the top surface 52 b ′ is parallel to the surface of the base 12. There is no limitation on the angle of the standing wall 52a '.

  Now, in the key switch device adopting the gear link system as in this embodiment, the number of teeth of each of the pair of link members is limited due to its miniaturization, and in the above-described embodiment, the link members meshing with each other are limited. The number of teeth on one side is 1 and the number of teeth on the other side is 2. When the number of teeth is small and the tooth shape corresponds to that of a normal spur gear, the link member is extended over the entire vertical movement stroke of the key top (that is, over the entire rotation range of the gear portion of each link member). It is very difficult to completely engage each other. More specifically, when the number of teeth is small, both gears are completely meshed only within a limited rotational motion range, so that the meshing of both link members becomes the worst near both ends of the vertical stroke, and the key top It leads to nodding (so-called wobble). In addition, it is difficult to increase the number of teeth due to restrictions on the shape and dimensions of the link member.

  Therefore, by making the gear portion of each link member into a helical gear shape with a twist angle, good meshing can be maintained over the entire vertical stroke even when the number of teeth is small. More specifically, by setting the twist angle to be equal to or greater than the rotation angle of the gear link, it is possible to engage both gears without rattling over the entire range including both ends of the vertical movement stroke. Key top operation can be realized.

  In addition, since the gear portion of the link member is normally provided in two pairs on both sides of the key top, the helical gears on each side are opposite to each other, and so-called helical gear-like characteristics can be obtained as a whole. It is good. Helical gears normally receive a load in the thrust direction (in this embodiment, a direction parallel to the key operation surface), but by reversing the twisting direction of the gears on both sides, the thrust direction load on each side is mutually reduced. Since they cancel each other, the stability of the key top can be further increased.

DESCRIPTION OF SYMBOLS 10 Key switch apparatus 12 Base 14 Key top 16 Link member 18 Stabilizer 20 Switch mechanism 22 Membrane switch sheet 24 Actuating member 32 Frame member 44 Long side part 46 Short side part 50 Base side engaging part 52, 52 'Stabilizer engaging part

Claims (6)

A base, a key top disposed above the base, a pair of link members that interlock with each other to guide and support the key top in the ascending / descending direction, and corresponding to the ascending / descending operation of the key top A switch mechanism that opens and closes a contact portion of the electric circuit, and each of the pair of link members has a sliding portion that is slidably connected to one of the base and the key top, and A key switch device in which the base or key top, which is a connection partner of the sliding portion, has a sliding engagement portion that is slidably engaged with the sliding portion,
A stabilizer member that is pivotally supported by the key top and is rotatably and slidably engaged with the base so as to assist in moving the key top up and down while maintaining a substantially horizontal posture. Further comprising
The stabilizer member includes a first portion that extends linearly from the key top side, and a second portion that has one end connected to an end portion of the first portion on the opposite key top side and extends in a direction different from the first portion. The first portion extends in parallel with the surface of the membrane switch sheet of the switch mechanism disposed on the upper surface of the base when the key top is pushed down to the lower limit position. When the key top is pushed down to the lower limit position, the opposite end of the second portion on the side opposite to the top of the key is at a maximum from the end on the opposite side of the key top of the first portion in the ascending / descending direction of the key top. Located below the membrane switch sheet thickness,
An end of the first portion on the side opposite to the key top is located between the key top and the base,
The membrane switch sheet has a first relief hole formed so that the stabilizer member does not interfere with the membrane switch sheet when the key top is located at a lower limit position . When the key top is pushed down to the lower limit position, the end portion on the opposite side of the key top of the second portion extends from the end portion on the opposite side of the key top of the first portion in the ascending / descending direction of the key top. The key switch device according to claim 1, which is located downward by a distance equal to the thickness. The membrane switch sheet is formed such that when the key top is located at a lower limit position, a stabilizer shaft support portion that is formed on the key top and rotatably supports the stabilizer member does not interfere with the membrane switch sheet. further comprising a second relief holes, the key switch device according to claim 1 or 2. The base engages with the base-side engagement portion so that a base-side engagement portion connected to the other end of the second portion of the stabilizer member is rotatable and slidable with respect to the base. And a stabilizer engaging portion that is convex on the upper surface side of the base by drawing of the metal plate that constitutes the base and at least a sliding range of the base side engaging portion with respect to the base in inner, having an upper surface and a parallel and flat portion of the base, the key switch device according to any one of claims 1-3. The base engages with the base-side engagement portion so that a base-side engagement portion connected to the other end of the second portion of the stabilizer member is rotatable and slidable with respect to the base. And a stabilizer engaging portion that protrudes toward the upper surface side of the base by cutting and bending the metal plate that constitutes the base and at least slides the base side engaging portion with respect to the base. in the dynamic range, having an upper surface and a parallel and flat portions of the base, the key switch device according to any one of claims 1-3. A keyboard comprising a plurality of key switch devices according to any one of claims 1 to 5 .

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