JP4703709B2 - Key switch device and keyboard - Google Patents

Description

  The present invention relates to a key switch device that is operated by a keystroke, and more particularly to a key switch device that is preferably used in a keyboard that is an input device of an electronic device. Furthermore, the present invention relates to a keyboard provided with a large number of such key switch devices.

  2. Description of the Related Art Conventionally, in the field of portable electronic devices such as notebook personal computers and notebook word processors, various devices for reducing the thickness of a device housing including a keyboard, that is, reducing the height of the device housing in order to improve the portability of the device. Technology has been proposed. In particular, when lowering the height of a keyboard having a large number of key switch devices operated by keystrokes, the key switch is maintained while maintaining the stroke amount of the key switch device at a predetermined amount in order to ensure a certain level of operability. It is required to reduce the overall height when the device is not operated (switch off) and when the device is pressed down (switch on).

  As a key switch device that can be used for a low-profile keyboard, for example, Patent Document 1 discloses a pair of a base, a key top arranged on the base, and a pair of guide tops that support the key top in the up-and-down direction in mesh with each other. Disclosed is a key switch device including a link member and a switch mechanism that opens and closes a contact of an electric circuit in response to a lifting operation of the key top. The pair of link members are combined in a V-shape when viewed from the side, meshed with each other in a gear shape at one end thereof, rotatably supported by the base, and slidably engaged with the key top at the other end. Combined in a reverse V shape when viewed from the side, meshed with each other in a gear shape, supported rotatably on the key top, and slidably engaged with the base at the other end Are illustrated. Each link member has a pair of arms extending substantially in parallel to each other, and a support shaft that is rotatably engaged with either the base or the key top at the tip region of the arms, and the rotation of the support shafts A plurality of teeth having teeth in a direction substantially orthogonal to the axis is provided.

  As for the key top, these link members mesh with each other and rotate in opposite directions around the support shaft, and each other end slides in a substantially horizontal direction along the key top or base. Thus, the base plate can be translated in a substantially vertical direction while maintaining a predetermined substantially horizontal posture. When the key top is lowered, the pair of link members are housed inside the key top in a substantially laid state. With such a configuration, it is possible to reduce the total height when the key switch device is not operated and when the key switch device is not pressed, while maintaining the keystroke stroke amount of the key top.

  In a conventional key switch device having this type of mesh-type link member, a plurality of teeth provided at the distal end regions of the pair of arms of each link member are toothed in a direction substantially perpendicular to the rotation axis of each link member. Therefore, the number and size of these teeth tend to affect the height of the key switch device. Therefore, for the purpose of reducing the overall height of the key switch device as much as possible, conventionally, the pair of arms of each link member has a minimum number of sheets (about 1 to 3) that allows the link members to be interlocked. Teeth are provided (see, for example, Patent Document 2).

JP-A-9-190735 Japanese Patent Laid-Open No. 10-283099

  In the key switch device having the above-described conventional interlocking link member, the number of teeth provided on the link member is reduced to the minimum, so that the upper limit position and the lower limit position of the key top lifting / lowering operation (keystroke stroke) in particular. However, the meshing between the teeth of the two link members becomes shallow, and there is a tendency that rattling of the two link members tends to occur due to an increase in backlash. As a result, the parallel movement of the key top from the upper limit position (start of pressing) to the lower limit position (end of pressing) of the keystroke stroke becomes unstable, and there is a concern that the keystroke operation characteristics of the key switch device are deteriorated. In particular, when the operator hits the vicinity of the outer edge of the top surface of the key top, the parallel movement of the key top tends to become unstable. Further, there is a concern that noise during keystroke operation may increase due to the shakiness of both link members and the shakiness of the key top resulting therefrom.

  Further, for example, in the key switch device described in Patent Document 1, an upper limit position of the keystroke stroke of the key top is formed by forming an opening that can receive at least one tooth of both link members engaged with each other. The lower limit position is lowered. However, the base needs to have a certain thickness in order to secure mechanical strength that can support both link members so as to be rotatable or slidable. As a result, there is a limit to the reduction of the overall height of the key switch device. It was happening.

Purpose is the present invention, the key switch having a pair of intermeshing link member, without affecting the keying stroke and key-entry operation properties of the key top, the overall height during non-operation and depression of the key switch device An object of the present invention is to provide a key switch device that can be reduced as much as possible.
Another object of the present invention is to provide a low-profile keyboard having a large number of such key switch devices and excellent in keystroke operation characteristics.

In order to achieve the above object, a first aspect of the present invention includes a base, a key top disposed on the base, and a pair of links that guide and support the key top in the up-and-down direction on the base in mesh with each other. In a key switch device comprising a member and a switch mechanism that opens and closes a contact of an electric circuit in response to a lifting operation of the key top, the base is operatively engaged with each of the pair of link members, and the link members And a second base disposed below the first base, the switch mechanism being sandwiched between the first base and the second base. A sheet-like membrane switch having a contact, and the membrane switch that is disposed on the membrane switch and elastically deforms as the key top moves up and down, while the key top is lowered. Each of the pair of link members is rotatably engaged with one of the first base and the key top, and the rotation of the rotation unit. One or more teeth having teeth in a direction substantially perpendicular to the axis, and each of the first base and the second base has an opening capable of receiving at least one tooth of the link member. A key switch device is provided.

According to a second aspect of the invention, in the key switch as set forth in claim 1, the membrane switch has at least one tooth acceptable penetration holes of the pair of link members, through holes first base and A key switch device disposed in alignment with each opening of a second base is provided.
According to a third aspect of the present invention, there is provided a keyboard configured by arranging a number of key switch devices according to the first or second aspect .

According to the present invention, it is possible to reduce the overall height when the key switch device is not operated and pressed down as much as possible without affecting the keystroke stroke and keystroke operation characteristics of the keytop. A keyboard incorporating a large number of such key switch devices has extremely excellent keystroke operation characteristics.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In the drawings, the same or similar components are denoted by common reference numerals.
Referring to the drawings, FIG. 1 is an exploded perspective view of a key switch device 10 according to the related art of the present invention, FIGS. 2 and 3 are enlarged views of link members used in the key switch device 10, and FIGS. 4 and 5 are keys. 3 is a cross-sectional view when the switch device 10 is not operated and when a pressing operation is performed. FIG. The key switch device 10 includes a base 12, a key top 14 having an operation surface 14 a which is arranged on the main surface 12 a of the base 12 so as to be movable in the up-and-down direction and can be pressed with the fingers of an operator, A pair of link members 16 that are guided and supported in the up and down direction and a switch mechanism 18 that opens and closes the contacts of the electric circuit corresponding to the up and down movement of the key top 14 are configured.

  The base 12 is a frame-like member having a substantially rectangular central opening 20 that is shielded by the key top 14. In the base 12, two pairs of sliding engagement portions 22 are separated from each other in the front-rear direction (left and right direction in FIG. 4, hereinafter the same) along a pair of opposed inner peripheral surfaces 12 b that define the central opening 20. Provided. Each sliding engagement portion 22 has a wall portion protruding from the main surface 12a and the inner peripheral surface 12b of the base 12 and extends in an L shape, and extends substantially parallel to the main surface 12a inside the wall portion. A guide groove 22a is formed. The two sliding engagement portions 22 constituting each set have their guide grooves 22 a arranged at corresponding positions along the pair of inner peripheral surfaces 12 b of the base 12. Further, the sliding engagement portions 22 on the corresponding side in each group are aligned in the front-rear direction along the inner peripheral surface 12 b of the base 12.

  The key top 14 is a dish-shaped member having a substantially rectangular planar shape, and two sets of pivotally attached portions 24 are juxtaposed in the front-rear direction on the inner surface 14b opposite to the operation surface 14a. Each pivot portion 24 is composed of a plate-like piece projecting upright from the inner surface 14b of the key top 14, and extends in a direction substantially perpendicular to the inner surface 14b through a bearing hole 24a penetrating in the plate thickness direction. A notch 24b communicating with 24a is formed. The two pivoting portions 24 constituting each set are arranged in a central region in the front-rear direction of the inner surface 14b of the key top 14 and are separated from each other by a distance that allows a pair of arm portions 26 of each link member 16 to be described later to be connected. The respective bearing holes 24a are positioned so as to align with each other in the axial direction thereof. Furthermore, the pivoting portions 24 on the corresponding side in each set are aligned in the front-rear direction on the inner surface 14 b of the key top 14.

  The pair of link members 16 have substantially the same shape as each other, and are connected to each other in a gear shape at one end thereof and are combined in an inverted V shape in a side view. Each link member 16 integrally includes a pair of arm portions 26 extending in parallel with each other and a connecting portion 28 that connects the arm portions 26 to each other at one end. At the first end of each arm portion 26 adjacent to the connecting portion 28, a support shaft 30 is projected coaxially to the opposite side of the connecting portion 28, and each arm portion 26 is separated from the connecting portion 28. At the two ends, a support shaft 32 is provided on the same side as the support shaft 30 so as to protrude coaxially. Each link member 16 is slidably fitted into the guide groove 22a of each sliding engagement portion 22 of the base 12 as a support portion 30 provided at the first end of each arm portion 26 as a sliding portion. A support shaft 32 provided at the second end of the arm portion 26 is rotatably fitted in a bearing hole 24a of each pivoting portion 24 of the key top 14 as a rotating portion. Placed in. Accordingly, each link member 16 rotates between the key top 14 and the base 12 as described later, with a rotation axis 32a (FIG. 2) shared by the support shafts 32 of the pair of arm portions 26 as a center.

  As shown in FIGS. 2 and 3, the pair of arm portions 26 of each link member 16 has teeth in a direction substantially perpendicular to the rotation axis 32 a of the support shaft 32 on the tip surface adjacent to the support shaft 32. A plurality of teeth 34 and 36 having bamboo are provided integrally. The plurality of teeth 34, 36 are arranged in the direction of the rotation axis by a single first tooth 34 capable of defining one pitch circle around the rotation axis 32 a and each tooth width with respect to the first tooth 34. It includes two second teeth 36 arranged at different positions and capable of defining a pitch circle substantially the same as the pitch circle formed by the first teeth 34. The first teeth 34 and the second teeth 36 are arranged at positions different from each other by the thickness of each tooth in the pitch circumferential direction. That is, the plurality of teeth 34, 36 are smoothly formed in a gear shape around the rotation axis 32 a of the support shaft 32 with one first tooth 34 meshing between the two second teeth 36. It has a shape, size and arrangement that can be rotated.

  The pair of arms 26 of each link member 16 is provided with first teeth 34 and second teeth 36 in the same arrangement. That is, the first teeth 34 and the second teeth 36 are respectively arranged on the inner sides of the arm portions 26 facing each other in the rotation axis direction. Therefore, when the pair of link members 16 are combined by engaging the first teeth 34 and the second teeth 36 with each other, the first teeth 34 and the second teeth 36 of each arm portion 26 of the one link member 16 are The second teeth 36 and the first teeth 34 of the respective arm portions 26 of the other link member 16 are simultaneously engaged with each other.

  Each of the pair of link members 16 slidably fits the support shaft 30 provided at the first end of each arm portion 26 into the guide groove 22a of each sliding engagement portion 22 of the base 12 as described above. In addition, the support shaft 32 provided at the second end of each arm portion 26 is rotatably fitted in the bearing hole 24a of each pivoting portion 24 of the key top 14, and between the key top 14 and the base 12 is inserted. Be placed. At this time, the pair of link members 16 includes a first tooth 34 and a second tooth 36 of each arm portion 26 of one link member 16, and a second tooth 36 and a first tooth of each arm portion 26 of the other link member 16. The teeth 34 are meshed with each other, so that they can rotate in conjunction with each other about the support shaft 32.

  Accordingly, in the key top 14, the pair of link members 16 rotate in opposite directions in synchronization with the respective support shafts 32, and the respective support shafts 30 slide in the substantially horizontal direction along the base 12. Thus, the base plate 12 is moved in a substantially vertical direction while maintaining a predetermined substantially horizontal posture in which the operation surface 14a is disposed substantially parallel to the main surface 12a. The upper limit position of the keystroke stroke of the key top 14 is a wall in which the sliding of the pair of link members 16 in the approaching direction of the support shafts 30 defines the guide grooves 22a of the sliding engagement portions 22 of the base 12. It is defined when it is locked by the part (FIG. 4). As the key top 14 descends from this upper limit position, the respective support shafts 30 of the pair of link members 16 slide in the mutually separating directions substantially perpendicular to the ascending / descending direction of the key top 14. When the key top 14 reaches the lower limit position of the key stroke, the pair of link members 16 are accommodated on the inner surface 14b side of the key top 14 and received in the opening 20 of the base 12 (FIG. 5).

  Here, in the key switch device 10, due to the above-described characteristic structure of the pair of link members 16, the teeth 34 of both link members 16 in the entire operation range from the upper limit position to the lower limit position of the key top 14 stroke. An extremely stable engagement between the 36 can be achieved. This is because the first teeth of each arm portion 26 of one link member 16 are enlarged as shown in FIG. 6 while both link members 16 are rotated over the entire operating range of the keystroke stroke of the key top 14. This is because 34 is always in contact with either the lower or upper second teeth 36a, 36b of each arm portion 26 of the other link member 16.

  Specifically, for example, at the upper limit position of the keystroke stroke, the first teeth 34 of one link member 16 are supported from below by contacting the lower second teeth 36a of the other link member 16. Backlash is generated by disengaging from the upper second teeth 36b of the other link member 16 (see FIG. 6A). However, at this time, the lower second teeth 36a of the same one of the link members 16 contact the first teeth 34 of the other link member 16 and are complementarily supported from above. The rattling between the teeth 34 and the second teeth 36a is substantially eliminated.

  When the key top 14 is pushed down from the upper limit position of the keystroke, the engagement of the first teeth 34 of each link member 16 with the upper and lower second teeth 36a, 36b of the counterpart link member 16 gradually deepens, and the deepest engagement region After that, the key top 14 reaches the lower limit position of the keystroke. During this time, since the meshing state of the first teeth 34 of each link member 16 and the second teeth 36a, 36b of the counterpart link member 16 changes stably in advancing simultaneously while exhibiting the complementary support action described above, Both link members 16 rotate smoothly in conjunction with each other.

  At the lower limit position of the keystroke, the first teeth 34 of one link member 16 come into contact with the upper second teeth 36b of the other link member 16 and are supported from above, but the lower side of the other link member 16 The contact with the second teeth 36a has become shallow, and backlash has started to occur (see FIG. 6B). However, at this time, the upper second teeth 36b of the same one link member 16 are in contact with the first teeth 34 of the other link member 16 and are complementarily supported from below, so that the first teeth meshed with each other. The rattling between 34 and the second tooth 36b is substantially eliminated. In this way, the pair of link members 16 are stably and reliably engaged with each other in the entire operation range from the upper limit position to the lower limit position of the key top stroke of the key top 14. The rattling and the shakiness of the key top 14 resulting therefrom are reduced as much as possible.

  The switch mechanism 18 of the key switch device 10 includes a sheet-like switch (referred to herein as a membrane switch) 42 having a pair of sheet substrates 40 each carrying a contact 38, a key top 14, and a membrane switch 42. And an actuating member 44 that is disposed between them and acts to close both the contacts 38 in accordance with the downward movement of the key top 14. A spacer 46 is installed between the pair of sheet substrates 40 of the membrane switch 42 to support the sheet substrates 40 at a predetermined interval and hold both the contacts 38 in an open state.

  Both sheet substrates 40 of the membrane switch 42 have a known flexible printed circuit board configuration, and contacts 38 that can be short-circuited to each other are provided on the surface of the film substrate. The sheet substrate 40 is supported on a support plate 48 under the base 12, and both the contacts 38 are disposed to face each other and are positioned substantially at the center of the opening 20 of the base 12. The actuating member 44 is a dome-shaped member integrally formed from a rubber material, and is disposed in the opening 20 of the base 12 with the dome top portion 44a facing the key top 14 side. The actuating member 44 is arranged with the dome top portion 44a spaced apart above the upper sheet substrate 40 when there is no load. A columnar pressing portion (not shown) extending toward the sheet substrate 40 is formed on the inner surface of the dome top portion 44 a of the operating member 44.

  The contact points 38 carried on the pair of sheet substrates 40 are normally held in an open state via the spacers 46 due to the essentially each sheet substrate 40, and are positioned below the pressing portion of the actuating member 44. . When an external force in a direction approaching the sheet substrate 40 is applied to the dome top portion 44a of the operation member 44, the operation member 44 is elastically deformed, and the pressing portion presses the upper sheet substrate 40 from the outer surface, whereby a pair of contact points 38 is obtained. Close.

  A flexible sheet member 50 formed of a resin material such as polyethylene terephthalate (PET) is installed between the base 12 and the upper sheet substrate 40. The operating member 44 is fixed to the outer surface of the sheet member 50 by an appropriate adhesive or the like at the dome opening end 44b. Alternatively, the sheet member 50 can be formed integrally with the operating member 44 from the same rubber material as the operating member 44.

  In the key switch device 10, when no external force is applied to the key top 14, the operating member 44 of the switch mechanism 18 is attached to the upper limit position (FIG. 4) where the key top 14 is separated vertically upward from the base 12 on the outer surface of the dome top 44 a. Support. At this time, the membrane switch 42 is in a state where the pair of contacts 38 are opened. When the key top 14 is pushed down by the operator's keystroke operation, the actuating member 44 is deformed while exerting an upward elastic biasing force on the key top 14, and immediately before the key top 14 reaches the lower limit position (FIG. 5). Then, the upper sheet substrate 40 is pressed from the outer surface to close the contact 38. When the pressing force on the key top 14 is released, the operating member 44 is elastically restored to return the key top 14 to the upper limit position, and the upper sheet substrate 40 is restored to open the contact 38.

  In the key switch device 10 having the above-described configuration, as described above, the pair of link members 16 stably and reliably mesh with each other in the entire operation range from the upper limit position to the lower limit position of the keystroke stroke of the key top 14, As a result, the backlash of both link members 16 and the backlash of the key top 14 resulting therefrom are reduced as much as possible. As a result, the key top 14 stably translates from the upper limit position (start of pressing) to the lower limit position (end of pressing) of the keystroke stroke. Even in such a case, the keystroke operation characteristics of the key switch device 10 can be maintained well. In addition, the noise during the keystroke operation can be effectively reduced by reducing the backlash of both the link members 16 and the key tops 12. Therefore, according to the key switch device 10, the number and size of the teeth 34, 36 provided on the both arm portions 26 of each link member 16 can be minimized without affecting the keystroke operation characteristics and the keystroke sound of the keytop. As a result, the overall height when the key switch device 10 is not operated and when the key switch device 10 is pushed down can be reduced as much as possible.

  FIG. 7 shows a keyboard 52 configured by arranging a large number of the key switch devices 10 described above. In the keyboard 52, the base 12 in each of the key switch devices 10 described above, the sheet substrate 40 of the membrane switch 42, the support plate 48, and the sheet member 50 to which the operation member 44 is fixed are all keys incorporated in the keyboard 52. A large base 12 ', a sheet substrate 40', a support plate 48 ', and a number of actuating members 44 common to the switch device 10 can be formed as a fixed sheet member 50'. Note that the configuration of the switch mechanism 18 having the dome-shaped operation member 44 described above is known per se, and the key switch device 10 and the keyboard 52 according to the present invention have various configurations other than the above configuration. A mechanism can be employed.

8 and 9 show a key switch device 60 according to the related art of the present invention in which the total height during non-operation and during depression is reduced by another method. The key switch device 60 is disposed above the base 62 so as to be movable in the up-and-down direction, and has a key top 64 having an operation surface 64a to be keyed by the operator's fingers, and the key top 64 above the base 62. A pair of link members 66 for guiding and supporting in the up and down direction and a switch mechanism 68 for opening and closing the contacts of the electric circuit corresponding to the up and down movement of the key top 64 are configured.

In the key switch device 60, the base 12 is omitted in the key switch device 10 described above, configured instead, members corresponding to the support plate 48 in the key switch 10 is, as a base 62 for supporting the pair of link members 66 Has been. The base 62 is made of, for example, a steel sheet metal material, and a part of the base 62 is punched and bent to form a pair of engaging support portions 70 projecting upright on the main surface 62a of the base 62. . The base 62 is further formed with an opening 72 which is a stamped trace of the engagement support 70 adjacent to the opposite sides of the engagement support 70. Each engagement support portion 70 is provided with a pair of bearing holes 70a penetrating in the plate thickness direction. The pair of engagement support portions 70 are disposed on the main surface 62a of the base 12 so as to be parallel to each other by a distance that allows connection of a pair of arm portions 74 of each link member 66 described later. Positioned to align with each other in the axial direction.

  The key top 64 is a dish-shaped member having a substantially rectangular planar shape, and two sets of sliding engagement portions 76 are provided on the inner surface 64b opposite to the operation surface 64a in the front-rear direction (the left-right direction in FIG. ) Are provided apart from each other. Each sliding engagement portion 76 has a wall portion protruding from the inner surface 64b of the key top 64 and extends in an L shape, and a guide groove extending substantially parallel to the inner surface 64b between the wall portion and the inner surface 64b. 76a is formed. The two sliding engagement portions 76 constituting each set are arranged in the front and rear end regions of the inner surface 64b of the key top 64 so as to be separated from each other by a distance capable of connecting a pair of arm portions 74 of each link member 66 described later. The guide grooves 76a are positioned so as to face each other. Further, the sliding engagement portions 76 on the corresponding side in each set are aligned in the front-rear direction on the inner surface 64 b of the key top 64.

Switch mechanism of the key switch device 60 68 has essentially the same configuration as the switch mechanism 18 of the key switch device 10 described above. Accordingly, corresponding constituent elements are denoted by the same reference numerals and description thereof is omitted. However, in the switch mechanism 68, the membrane switch 42 is fixedly placed on the main surface 62 a of the base 62 below the key top 64, and is attached to both the pair of sheet substrates 40 each carrying the contact 38. A pair of through holes 78 arranged in alignment with the pair of openings 72 of 62 are formed. Further, the sheet member 50 fixed on the membrane switch 42 with the dome-shaped operation member 44 fixed is provided with a pair of through holes 80 arranged in alignment with the pair of through holes 78 of both sheet substrates 40. It is formed. Accordingly, the pair of engagement support portions 70 provided in the base 62 pass above the membrane switch 42 and the sheet member 50 through the pair of through holes 78 of the sheet substrates 40 and the pair of through holes 80 of the sheet member 50. Protruding.

  The pair of link members 66 of the key switch device 60 have substantially the same shape as each other, and are connected to each other in a gear shape at one end thereof and combined in a V shape in a side view. Each link member 66 is integrally provided with a pair of arm portions 74 extending in parallel to each other and a connecting portion 82 that connects the arm portions 74 to each other at one end. At the other end of each arm portion 74 away from the connecting portion 82, a support shaft 84 is provided so as to be coaxial with the opposite side of the connecting portion 82. Each link member 66 is slidably fitted in the guide groove 76a of each sliding engagement portion 76 of the key top 64 as a connecting portion 82 of each arm portion 74 as a sliding portion. A support shaft 84 provided at the end is rotatably fitted in a bearing hole 70 a of each engagement support portion 70 of the base 62 as a rotation portion, and is disposed between the key top 64 and the base 62.

  A plurality of teeth 86 having teeth in a direction substantially orthogonal to the rotation axis of the support shaft 84 are integrally formed on the pair of arm portions 74 of each link member 66 on the tip surfaces adjacent to the support shafts 84. Provided. The pair of link members 66 are configured so that the plurality of teeth 86 of each arm portion 74 of one link member 66 and the plurality of teeth 86 of each arm portion 74 of the other link member 66 are engaged with each other, respectively. It can be rotated in conjunction with each other around 84. Accordingly, the plurality of teeth 86 of each link member 66 can be smoothly rotated like a gear while meshing with the plurality of teeth 86 similarly provided on the corresponding arm portions 74 of the link member 66 of the interlocking counterpart. It has shape, size and arrangement. In this way, each link member 66 rotates between the key top 64 and the base 62 about the rotation axis shared by the support shaft 84 of the pair of arm portions 74 as the key top 64 moves up and down. To do.

  In the key top 64, the pair of link members 66 rotate in opposite directions in synchronization with the respective support shafts 84, and the respective connecting portions 82 slide in the substantially horizontal direction along the key top 64. Thus, the operation surface 64a is translated in a substantially vertical direction with respect to the base 62 while maintaining a predetermined substantially horizontal posture in which the operation surface 64a is disposed substantially parallel to the main surface 62a. The upper limit position of the keystroke stroke of the key top 64 is that the sliding of the connecting portions 82 of the pair of link members 66 in the mutual approach direction defines the guide grooves 76 a of the sliding engagement portions 76 of the key top 64. It is defined when it is locked by the wall portion (FIG. 9A). As the key top 64 is lowered from the upper limit position, the connecting portions 82 of the pair of link members 66 slide in the mutually separating directions substantially perpendicular to the ascending / descending direction of the key top 64. When the key top 64 reaches the lower limit position of the keystroke stroke, the pair of link members 66 are accommodated on the inner surface 64b side of the key top 64 (FIG. 9B).

  In the key switch device 60, the pair of openings 72 of the base 62, the pair of through holes 78 of the membrane switch 42, and the pair of through holes 80 of the sheet member 50 all smooth at least one tooth 86 of the link member 66. And having a size and shape acceptable. For example, when the key top 64 is at the upper limit position of the key stroke, as shown in FIG. 9A, some of the plurality of meshed teeth 86 of the pair of link members 66 extend below the support shafts 84. At this time, the teeth 86 extending downward are smoothly received in the pair of through holes 80 of the sheet member 50, the pair of through holes 78 of the membrane switch 42, and the pair of openings 72 of the base 62. Therefore, the bearing hole 70a for supporting the support shaft 84 of each link member 66 can be arranged as low as possible. As a result, the height of each engagement support portion 70 provided in the base 62 can be made high. As low as possible.

  In the key switch device 60 having the above configuration, the base disposed between the key top 64 and the membrane switch 42 is eliminated, and conventionally, a support plate disposed below the membrane switch 42 is used together as the base 62. The overall height of the key switch device 60 is effectively reduced while ensuring the mechanical strength capable of supporting the pair of link members 66 so as to be rotatable or slidable. Moreover, as described above, the through holes 80 and 78 and the openings 72 that can receive some of the plurality of meshed teeth 86 of the pair of link members 66 are formed below the link members 66. Since the membrane switch 42 and the base 62 are provided, the engagement support portions 70 of the base 62 can be made as low as possible. Therefore, according to the key switch device 60, the overall height when the key switch device 60 is not operated and pressed down can be reduced as much as possible without affecting the keystroke stroke and keystroke operation characteristics of the key top 64.

  In the above-described configuration, a means is added so that the support shaft 84 provided in the arm portion 74 of each link member 66 can be easily attached to the bearing hole 70 a provided in each engagement support portion 70 of the base 62. It is desirable. For example, as shown in FIG. 10A, a flat surface 84a extending in the axial direction is formed on the cylindrical outer surface of the support shaft 84 to form a support shaft 84 having a D-shaped cross section. A notch 70b communicating with 70a can be formed. In this configuration, mutual interference is avoided by passing the notch 70b with the flat surface 84a of the support shaft 84 in the vertical direction, and the support shaft 84 can be easily inserted into the bearing hole 70a. Alternatively, as shown in FIG. 10 (b), a tapered surface 84 b can be provided on the cylindrical outer surface of the support shaft 84. In this configuration, by causing the tapered surface 84b of the support shaft 84 to interfere with the engagement support portion 70, bending of the arm portion 74 of the link member 66 is promoted, and as a result, the support shaft 84 can be easily inserted into the bearing hole 70a. Can be inserted.

  In addition, while using together a support plate as a base, the structure which provides the engagement support part which operatively supports each link member and supports these link members to this base is limited to above-described embodiment. For example, it is employable also for the structure of a link member in the key switch apparatus 10 of FIG. In this case, the engagement support portion of the base is formed as a slide engagement portion that slidably supports the slide portion of the link member (for example, the support shaft 30 of the link member 16 in FIG. 1). In addition, the membrane switch 42 and the sheet member 50 in the key switch device 60 described above have an outer shape that does not contact the plurality of teeth 86 of the pair of link members 66 that are engaged with each other, instead of having the through holes 78 and 80. You can also. Further, it goes without saying that a keyboard including a large number of the key switch devices 60 arranged as described above can be configured in the same manner as the keyboard 52 shown in FIG.

Figure 11 shows a key switch 90 according to the implementation embodiments of the present invention having a reduced overall height during non-operation and pressing operation. The key switch device 90, except for the configuration of the base has essentially the same configuration as the key switch device 60 described above. Accordingly, corresponding constituent elements are denoted by the same reference numerals and description thereof is omitted.

  The base of the key switch device 90 includes a first base 94 including an engagement support portion 92 that operatively engages each of the pair of link members 66 and operably supports the link members 66, and the first base 94. And a second base 96 disposed below the second base 96. Between the first base 94 and the second base 96, the membrane switch 42 constituting the switch mechanism 68 and the sheet member 50 to which the operation member 44 is fixed are sandwiched.

  The first base 94 is a member corresponding to the base 12 in the key switch device 10 described above. The first base 94 is a substantially circular center opening 98 shielded by the key top 64, and a rectangle penetratingly formed on both sides of the center opening 98. And a pair of engagement support portions 92 each having an opening. Two bearing holes 92a are provided on the inner wall of each engagement support portion 92 so as to be spaced apart from each other and aligned in the front-rear direction. Each engagement support portion 92 has a size and a shape that can smoothly receive the distal end region of the arm portion 74 including a plurality of meshed teeth 86 and a support shaft 84 of the pair of link members 66. Further, the support shafts 84 of the pair of link members 66 that are meshed with each other are fitted into the two bearing holes 92a of the respective engagement support portions 92 so as to be rotatable. Further, a dome-shaped actuating member 44 is received in the central opening 98.

  The second base 96 is a member corresponding to the support plate 48 in the key switch device 10 described above, and is similarly paired with a pair of rectangular openings at positions aligned with the pair of engagement support portions 92 of the first base 94. 100 is formed. Each opening 100 has a size and a shape capable of receiving at least one tooth 86 of the pair of link members 66 in the meshed state. The pair of through holes 78 formed in the pair of sheet substrates 40 of the membrane switch 42 and the pair of through holes 80 formed in the sheet member 50 are a pair of engagement support portions 92 and a second base 96 of the first base 94. The pair of openings 100 are arranged in alignment with each other.

  In the key switch device 90 having the above-described configuration, an engagement support portion 92 for supporting the link member 66 is formed as a through opening in the first base 94 disposed between the key top 64 and the membrane switch 42. In addition, through holes 80 and 78 and openings 100 that can receive some of the plurality of meshed teeth 86 of the pair of link members 66 are formed below the first base 94, the sheet member 50, the membrane switch 42, and Since the second base 96 is provided, the overall height of the key switch device 90 is effectively reduced while ensuring the mechanical strength capable of supporting the pair of link members 66 in a rotatable or slidable manner. Therefore, according to the key switch device 90, the overall height when the key switch device 90 is not operated and pressed down can be reduced as much as possible without affecting the keystroke stroke and keystroke operation characteristics of the key top 64. .

It is a disassembled perspective view of the key switch apparatus by the related technique of this invention. It is an expansion perspective view of the link member used with the key switch apparatus of FIG. It is (a) enlarged left side view and (b) enlarged right side view of the link member used in the key switch device of FIG. FIG. 4 is a cross-sectional view taken along line IV-IV when the key switch device of FIG. 1 is assembled, showing a state where the key top is at the upper limit position of the keystroke stroke. It is sectional drawing of the key switch apparatus corresponding to FIG. 4, and shows the state which has a key top in the lower limit position of a keystroke. FIG. 2 is an enlarged view showing a state in which a pair of link members in the key switch device of FIG. 1 is engaged, (a) when the key top is at the upper limit position of the keystroke stroke and (b) when the keytop is at the lower limit position of the keystroke stroke. Indicates. 1 is a partially cutaway perspective view of a keyboard according to an embodiment of the present invention. It is a disassembled perspective view of the key switch apparatus by the related technique of this invention. FIG. 9 is a cross-sectional view taken along line IX-IX when the key switch device of FIG. 8 is assembled, in which (a) the key top is in the upper limit position of the keystroke stroke, and (b) the keytop is in the lower limit position of the keystroke stroke. Indicates the state. FIGS. 9A and 9B are enlarged views of an engagement portion between a link member and a base in the key switch device of FIG. It is an expansion perspective view of a shaft and an engagement support part. It is an exploded perspective view of the key switch device according to the implementation embodiments of the present invention.

Explanation of symbols

10, 60, 90 Key switch device 12, 62 Base 14, 64 Key top 16, 66 Link member 18, 68 Switch mechanism 30, 32, 84 Support shaft 34 First tooth 36 Second tooth 42 Membrane switch 44 Actuating member 48 Support Plate 50 Sheet member 52 Keyboard 70, 92 Engagement support 72, 100 Opening 78, 80 Through hole 86 Teeth

Claims (3)

A base, a key top disposed on the base, a pair of link members that interlock and interlock with each other to guide and support the key top in the ascending / descending direction on the base, and electric corresponding to the ascending / descending operation of the key top In a key switch device comprising a switch mechanism for opening and closing circuit contacts,
The base includes a first base that includes an engagement support portion that operatively engages each of the pair of link members and operably supports the link members, and a first base disposed below the first base. With two bases,
The switch mechanism is sandwiched between the first base and the second base, has a sheet-like membrane switch having the contact, and is disposed on the membrane switch, and is elastic as the key top moves up and down. An operating member that deforms and closes the contact by pressing the membrane switch while the key top is lowered,
Each of the pair of link members is toothed in a direction substantially perpendicular to a rotation axis of the rotation portion and a rotation portion that rotatably engages one of the first base and the key top. And each of the first base and the second base has an opening capable of receiving at least one of the link members;
A key switch device characterized by.   The membrane switch has a through hole that can receive at least one of the teeth of the pair of link members, and the through hole is arranged in alignment with the openings of the first base and the second base. The key switch device according to claim 1.   A keyboard configured by arranging a large number of key switch devices according to claim 1 or 2.

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