JP2009059716A - Key-switching device and keyboard - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce collision sounds between components when depressing a keytop to a lower end position in a key-switching device capable of performing a key striking operation. <P>SOLUTION: The key switching device 10 comprises the keytop 14 arranged on a base 12, a pair of link members 16, 18 for guiding and supporting the keytop 14 in the rise and fall direction by inter connecting each other, and a switch mechanism 20 for opening and closing a contact in response to rise and fall actions of the keytop 14. The switch mechanism 20 has a membrane switch 50, and an operation member 52 arranged on the membrane switch 50 and connected with a sheet member 60. A pair of elastic pieces 64 are penetrated into the sheet member 60 by neighboring to a connecting section between the operation member 52 and the sheet member 60. At least one of the keytop 14 and the link members 16, 18 is collided with the elastic piece 16 just before the keytop 14 arrives to the lower end position. Thus, the collision sounds can be reduced. <P>COPYRIGHT: (C)2009,JPO&INPIT

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).

  On the other hand, a portable electronic device has convenience that can be used in various places because it is easy to carry, but when used in a place where quietness is required such as a library, a key switch device incorporated in a keyboard Noise during keystroke operation becomes a problem. Therefore, in recent years, in portable electronic devices, it has been desired not only to ensure the operability of the key switch device of the keyboard, but also to reduce the noise during keystroke operations as much as possible.

  As a key switch device that can be used for a low-profile keyboard, for example, Patent Document 1 discloses a base, a key top disposed on the base, and a pair of links that interlock with each other and guide and support the key top on the base in the up-and-down direction. Disclosed is a key switch device including 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 pair of link members are combined in an inverted V shape when viewed from the side, meshed with each other in a gear shape at one end thereof, rotatably supported by the key top, and slidably engaged with the base at the other end. Things are illustrated.

  The key tops move in the opposite direction in conjunction with each other, with each link member centering on one end, and the other end slides in a substantially horizontal direction along the base, so that the key top is substantially vertical to the base. It is possible to translate in a direction while maintaining a predetermined substantially horizontal posture. When the key top is lowered, the pair of link members are accommodated inside the key top and are substantially sandwiched between the upper surface of the base and the inner surface of the key top. 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.

  The switch mechanism in this key switch device includes a sheet-like switch (referred to herein as a membrane switch) having a pair of sheet substrates disposed under the base and carrying a pair of contacts, a key top, and a membrane switch. And an actuating member that is arranged to close the pair of contacts as the key top is lowered. The actuating member is a dome-shaped member integrally formed from a rubber material, and is disposed on the membrane switch with the dome top portion facing the key top side through an opening formed in the base at a position below the key top. The A spacer is disposed between the pair of sheet substrates of the membrane switch, whereby the pair of contacts are normally held in an open state and positioned below the pressing portion provided on the inner surface of the dome top portion of the operating member. .

  When an external force is not applied to the key top, the actuating member biases and supports the key top at an upper end position vertically away from the base on the outer surface of the top of the dome. On the other hand, when the key top is pushed down by the operator's keystroke operation, the actuating member is deformed while exerting an upward elastic biasing force on the key top, and the upper part of the membrane switch is pushed by the pressing portion as the key top approaches the lower end position. The sheet substrate is pressed from the outer surface to close the contact. When the pressing force to the key top is released, the operating member is elastically restored to return the key top to the initial position, and the upper sheet substrate is restored to open the contact.

  In a low-profile keyboard with many key switch devices of the type described above, when the keyboard is used, the key tops of all the key switch devices are held at the protruding position (corresponding to the upper end position of the keystroke stroke) so that the keyboard is not used. When used (for example, when carrying), the key tops of all key switch devices are collectively displaced to a retracted position (corresponding to the lower end position of the keystroke stroke) where the keystroke operation is lower than the protruding position. A configuration for further improvement is also known. For example, Patent Document 2 discloses a key in which a dome-shaped actuating member is fixedly connected to an upper sheet substrate of a membrane switch, and the actuating member and the membrane switch can be moved sideways integrally below the key top. A switch device is disclosed.

  According to this key switch device, when the keyboard is used, the actuating member is arranged at the first position that biases and supports the key top in the protruding position, and when the keyboard is not used, the second position does not exert a biasing force on the key top. The actuating member is arranged to move laterally. When the actuating member is placed in the second position, the key top is lowered by its own weight under the guidance of the link member, and is automatically displaced from the protruding position to the retracted position. The actuating member in the second position is accommodated in the inner space of the key top while maintaining its initial dome shape.

JP-A-9-190735 JP-A-9-63402

  In the above-described conventional key switch device, in general, at the time of a keystroke operation, at least one of a collision between the key top and the base, a collision between the key top and the sheet substrate of the membrane switch, and a collision between each link member and the sheet substrate of the membrane switch. When one occurs, the lowering action of the key top reaches a limit, i.e. the key top is placed at the lower end position of the keystroke. The contact point of the membrane switch is closed by the actuating member immediately before the key top reaches the lower end position.

  Usually, the noise that becomes a problem during the key-pressing operation of the key switch device is mainly the sound generated by the collision between the respective members when the key top reaches the lower end position. However, such a configuration in which the lower end position of the key top is defined by the collision between the respective members is effective for reducing the height dimension of the key switch device, and therefore, a structure that avoids the collision itself. Is not desirable from the viewpoint of reducing the height of the keyboard. Therefore, it is necessary to reduce the collision sound between the above members as much as possible without affecting the keystroke stroke amount of the key switch device, the total height when not operated and pressed, the keystroke operability, etc. Become.

  On the other hand, in a low-profile keyboard that has a configuration in which the key tops of all key switch devices can be displaced collectively between the protruding position and the retracted position, the operating members of each key switch device are smoothly shifted to the side. In order to improve the operability of the keyboard, it is important to be able to displace the key top quickly and accurately. In general, this type of operating member can smoothly move from a first position that biases the key top to the protruding position to a second position that does not exert a biasing force on the key top, but conversely from the second position to the first position. When heading, the actuating member itself must move while pushing the key top to the protruding position, which tends to prevent smooth movement.

  In particular, when the pair of link members that guide and support the key top engage with the base at one end and slide in a substantially horizontal direction on the sheet substrate of the membrane switch, It has been found that smooth movement from position to the first position is often difficult. Usually, when the operating member moves from the second position to the first position, a pressing force is applied obliquely upward from the dome-shaped side wall portion of the operating member to the key top. At this time, the pair of link members are configured as described above. When the link member is provided, each link member acts as a lever and presses the sheet substrate of the membrane switch downward at each sliding end. That is, a force for shifting the actuating member to the side is applied to the sheet substrate via the key top and the link member, and as a result, the actuating member is prevented from moving.

SUMMARY OF THE INVENTION An object of the present invention is to provide a key switch device having a key top that is operated by key pressing, without affecting the stroke amount of the key switch device, the total height during non-operation and pressing, the key pressing operability, etc. An object of the present invention is to provide a key switch device that can reduce as much as possible the collision noise between components when the is pushed down to the lower end position.
Another object of the present invention is to provide a keyboard having a large number of such key switch devices and excellent in quietness during keystroke operation.

Still another object of the present invention is to provide a key switch device having a movable actuating member for displacing the key top between the projecting position and the retracted position. It is an object of the present invention to provide a key switch device capable of quickly and accurately displacing.
Still another object of the present invention is to provide a keyboard having a large number of such key switch devices and excellent in operability capable of quickly and accurately displacing all the key switch devices at once between a use form and a non-use form. Is to provide.

  In order to achieve the above object, the invention described in claim 1 is characterized in that a base, a key top disposed on the base, and each of them interlock with each other and are operatively engaged with both the base and the key top. In a key switch device comprising a pair of link members for guiding and supporting the key top in the up-and-down direction on the base, and a switch mechanism for opening and closing the contact of the electric circuit in response to the up-and-down operation of the key top, There is provided a key switch device comprising a silencer for reducing a collision sound generated when a lower end position of a stroke is reached.

According to a second aspect of the present invention, in the key switch device according to the first aspect, the muffling means includes an elastically deformable buffer portion provided in the switch mechanism, and the buffer portion immediately before the key top reaches the lower end position. Provided is a key switch device that elastically deforms.
According to a third aspect of the present invention, in the key switch device according to the second aspect, the switch mechanism is disposed in an opening provided in the base below the key top, and has a membrane switch having a contact point on the membrane switch. And an actuating member that elastically deforms as the key top moves up and down and closes the contact by pressing the membrane switch while the key top moves toward the lower end position, and the buffer portion is associated with the actuating member. A key switch device provided is provided.

  According to a fourth aspect of the present invention, in the key switch device according to the third aspect, the actuating member is connected to a sheet member disposed on the membrane switch, and the buffering portion is a connection portion between the actuating member and the sheet member. And a key switch device in which at least one of the key top and the pair of link members collides with the elastic piece immediately before the key top reaches the lower end position.

According to a fifth aspect of the present invention, in the key switch device according to the fourth aspect, the operating member is fixed to the sheet member via a rubber adhesive, and the elastic piece is formed from the rubber adhesive. I will provide a.
According to a sixth aspect of the present invention, in the key switch device according to any one of the third to fifth aspects, the actuating member is a dome-shaped member made of a rubber material, and the buffering portion is at the top of the dome of the actuating member. An additionally formed key switch device is provided.

According to a seventh aspect of the present invention, in the key switch device according to the sixth aspect, the buffer portion is made of an elastic auxiliary member attached to the top of the dome of the operating member, and the elastic auxiliary member has a smaller elastic modulus than the rubber material. A key switch device formed from a material is provided.
The invention according to claim 8 provides the key switch device according to any one of claims 3 to 7, further comprising a positioning mechanism for positioning the operating member at a predetermined position in the base. .

According to a ninth aspect of the present invention, in the key switch device according to any one of the first to eighth aspects, the silencer comprises an elastically deformable buffer portion provided in association with the base, and the key top is Provided is a key switch device in which a key top collides with a buffer portion immediately before reaching a lower end position.
According to a tenth aspect of the present invention, in the key switch device according to the ninth aspect, the buffer portion includes a plurality of leaf spring portions formed on the base, and the leaf spring portions correspond to the outer edge region of the key top. Provided is a key switch device that is distributed at a position where the key switch is provided.

According to an eleventh aspect of the present invention, in the key switch device according to the ninth or tenth aspect, the buffer portion includes a plurality of elastic members installed in a plurality of recesses formed in the base, and the elastic members are the key members. Provided is a key switch device that is distributed and arranged at positions corresponding to an outer edge region of a top.
A twelfth aspect of the present invention is the key switch device according to any one of the first to eleventh aspects, wherein the silencer includes a collision portion provided locally on at least one of the key top and the base. Provided is a key switch device that collides with a base via a collision portion when a top reaches a lower end position.

  According to a thirteenth aspect of the present invention, a base, a key top disposed on the base, and each of them interlock with each other and are operatively engaged with both the base and the key top to raise and lower the key top on the base. In a key switch device comprising a pair of link members that guide and support in a direction and a switch mechanism that opens and closes a contact of an electric circuit in response to a lifting operation of the key top, at least in one horizontal direction of the key top on the base There is provided a key switch device comprising locking means for substantially preventing the movement of the key switch device.

According to a fourteenth aspect of the present invention, in the key switch device according to the thirteenth aspect, the locking means is provided on the key top and the first wall provided on the base, and is slidably engaged with the first wall. And a second switch wall.
The invention according to claim 15 is the key switch device according to claim 13 or 14, wherein the switch mechanism is disposed in an opening provided in the base below the key top, and has a membrane switch having a contact, and a membrane switch And an actuating member that presses the membrane switch to close the contact point while the key top moves toward the lower end position, and the actuating member urges the key top to the upper end position and raises and lowers the key top. Provided is a key switch device that is movable in a horizontal direction between a first position that is elastically deformed with an operation and a second position that maintains an initial shape without exerting an urging force on a key top.

  According to a sixteenth aspect of the present invention, there is provided a keyboard configured by arranging a number of key switch devices according to any one of the first to fifteenth aspects.

  According to the present invention, in a key switch device having a key top that is operated by key pressing, the key top is not affected without affecting the stroke amount of the key switch device, the total height when not operated and pressed, the key pressing operability, and the like. It is possible to reduce as much as possible the collision noise between the constituent members when the is pushed down to the lower end position. A keyboard incorporating a large number of such key switch devices is extremely excellent in quietness during keystroke operation.

  Furthermore, according to the present invention, in a key switch device having a movable operating member for displacing the key top between the protruding position and the retracted position, the key top can be quickly moved by smoothly shifting the operating member to the side. And it becomes possible to displace accurately. A keyboard incorporating a large number of such key switch devices is extremely excellent in operability capable of quickly and accurately displacing all the key switch devices at once between a use form and a non-use form.

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 a first embodiment of the present invention, FIG. 2 is a sectional view when the key switch device 10 is not operated, and FIG. It is sectional drawing at the time of lowering operation. The key switch device 10 includes a base 12, a key top 14 having an operation surface 14 a that 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, and the key top 14 as the base 12. A pair of link members 16 and 18 that are guided and supported in the up-and-down direction and a switch mechanism 20 that opens and closes the contact of the electric circuit in response to the up-and-down operation of the key top 14 are configured.

  The base 12 is a frame-like member having a substantially rectangular center opening 22 that is shielded by the key top 14. In the base 12, two sets of sliding engagement portions 24 are separated from each other in the front-rear direction (left-right direction in FIG. 2, hereinafter the same) along a pair of opposed inner peripheral surfaces 12 b that define the central opening 22. Provided. Each sliding engagement portion 24 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 24a is formed. The two sliding engagement portions 24 constituting each set have their guide grooves 24 a arranged at corresponding positions along the pair of inner peripheral surfaces 12 b of the base 12. Further, the sliding engagement portions 24 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-like member having a substantially rectangular planar shape, and two sets of pivotally attached portions 26 are juxtaposed with each other on the inner surface 14b opposite to the operation surface 14a. Each pivoting portion 26 is formed 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 by a bearing hole 26a penetrating in the plate thickness direction. A notch 26b communicating with 26a is formed. The two pivoting portions 26 constituting each pair are separated from each other by a distance capable of receiving the first and second arm portions 28 and 30 of the link members 16 and 18 in the center region in the front-rear direction of the inner surface 14b of the key top 14. The bearing holes 26a are positioned so as to align with each other in the axial direction thereof. Furthermore, the pivoting portions 26 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 and 18 are composed of a first link member 16 and a second link member 18 having substantially the same shape that are connected to each other in a gear shape at one end thereof and combined in an inverted V shape in a side view. Each link member 16, 18 integrally includes a first arm portion 28 and a second arm portion 30 that extend in parallel to each other, and a connecting portion 32 that connects the arm portions 28, 30 to each other. The first arm portion 28 is provided with two teeth 34 on the distal end surface of the first end remote from the connecting portion 32, and the second arm portion 30 is provided with the distal end surface of the first end remote from the connecting portion 32. One tooth 36 is provided. At the second end of each arm portion 28, 30 adjacent to the connecting portion 32, a support shaft 38 protrudes coaxially to the opposite side of the connecting portion 32, and at the first end of each arm portion 28, 30. The support shafts 40 are coaxially provided on the same side as the support shaft 38.

  Each of the first and second link members 16, 18 can freely slide a support shaft 38 provided at the second end of each arm portion 28, 30 in the guide groove 24 a of each sliding engagement portion 24 of the base 12. And a pivot 40 provided at the first end of each arm 28, 30 is rotatably fitted in a bearing hole 26a of each pivoting portion 26 of the key top 14, so that the key top 14 and the base 12 is arranged. At this time, the first link member 16 and the second link member 18 are connected to the two teeth 34 provided at the first end of each first arm portion 28 and the first end of each second arm portion 30. One of the provided teeth 36 is engaged with each other, so that the teeth 36 can rotate in conjunction with each other about the support shaft 40.

  Accordingly, in the key top 14, the first and second link members 16 and 18 swing in opposite directions in synchronization with the respective support shafts 40, and the respective support shafts 38 are substantially horizontal along the base 12. Is moved in a substantially vertical direction with respect to the base 12 while maintaining a predetermined substantially horizontal posture in which the operation surface 14a is disposed substantially parallel to the main surface 12a. The upper end position of the keystroke stroke of the key top 14 is such that the first and second link members 16, 18 slide in the direction of mutual approach of the respective support shafts 38, and the guide grooves 24 a of the respective sliding engagement portions 24 of the base 12. Is defined when locked by the wall portion defining (FIG. 2). As the key top 14 descends from the upper end position, the respective support shafts 38 of the first and second link members 16 and 18 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 end position of the key stroke, the first and second link members 16 and 18 are accommodated on the inner surface 14b side of the key top 14 and received in the opening 22 of the base 12 (FIG. 3). ).

  The key switch device according to the present invention is not limited to the link members 16 and 18 shown in the above embodiment as a pair of link members, which is a component of the key switch device. Applicable to switch devices. As such another pair of link members, those combined in an X shape in a side view and connected to each other at an intersection (see, for example, Japanese Utility Model Publication No. 5-66832), in an X shape in a side view. Examples are those that are combined and slidably connected to each other at the intersection (see, for example, JP-A-9-27235).

  As shown in a cross-sectional view in FIG. 4, the switch mechanism 20 includes a membrane switch 50 having a pair of sheet substrates 46 and 48 that carry a pair of contacts 42 and 44 facing each other, a key top 14, and a membrane switch 50. And an actuating member 52 that acts to close both contacts 42 and 44 as the key top 14 is lowered. Between the pair of sheet substrates 46 and 48 of the membrane switch 50, a spacer 54 is installed that supports the sheet substrates 46 and 48 at a predetermined interval and holds both the contacts 42 and 44 in an open state.

  Both sheet substrates 46 and 48 of the membrane switch 50 have a configuration of a known flexible printed circuit board, and contacts 42 and 44 that can be short-circuited to each other are provided on the surface of the film substrate. The sheet substrates 46 and 48 are supported on a support plate 56 under the base 12, and both the contacts 42 and 44 are positioned substantially at the center of the opening 22 of the base 12. The actuating member 52 is a dome-shaped member integrally formed from a rubber material, and is disposed in the opening 22 of the base 12 with the dome top 52a facing the key top 14 side. The operating member 52 is arranged with the dome top portion 52a spaced apart above one of the upper sheet substrates 46 when there is no load. A columnar pressing portion 58 extending toward the sheet substrate 46 is formed on the inner surface of the dome top portion 52 a of the operating member 52.

  The pair of contacts 42, 44 carried by the sheet substrates 46, 48 are normally held in the open state of FIG. The pressing portion 58 is positioned below the substantially flat front end surface 58a. When an external force in a direction approaching the sheet substrate 46 is applied to the dome top portion 52a of the operation member 52, the operation member 52 is elastically deformed, and the front end surface 58a of the pressing portion 58 presses the sheet substrate 46 from the outer surface. The pair of contacts 42 and 44 are closed.

  A flexible sheet member 60 formed of a resin material such as polyethylene terephthalate (PET) is installed between the base 12 and the upper sheet substrate 46. The operating member 52 is fixed to the outer surface of the sheet member 60 with an appropriate adhesive 62 at the dome opening end 52b. In this case, the sheet member 60 preferably has an opening 60 a corresponding to the dome opening end 52 b of the actuating member 52. Alternatively, the sheet member 60 can be integrally formed with the operating member 52 from the same rubber material as the operating member 52.

  When a keyboard is configured by arranging a large number of key switch devices 10 each having the switch mechanism 20, a sheet member in which both the sheet substrates 46 and 48 and the operation member 52 of the membrane switch 50 in each key switch device 10 are fixed. 60 is formed of a large sheet material common to all the key switch devices 10 incorporated in the keyboard. Similarly, the base 12 and the support plate 56 are made of a large material common to all the key switch devices 10 incorporated in the keyboard.

  In the key switch device 10, when no external force is applied to the key top 14, the operating member 52 of the switch mechanism 20 is attached to the upper end position (FIG. 2) where the key top 14 is vertically separated from the base 12 on the outer surface of the dome top 52 a. Support. At this time, the membrane switch 50 is in a state where the pair of contacts 42 and 44 are opened. When the key top 14 is pushed down by the operator's keystroke operation, the actuating member 52 is deformed while exerting an upward elastic biasing force on the key top 14 until the key top 14 reaches the lower end position (FIG. 3). In the meantime, the upper sheet substrate 46 is pressed from the outer surface by the pressing portion 58 to close the contacts 42 and 44. When the pressing force on the key top 14 is released, the operating member 52 is elastically restored to return the key top 14 to the upper end position, and the upper sheet substrate 46 is restored to open the contacts 42 and 44. .

  In the key switch device 10 having the above-described configuration, the key top 14 and the base 12 collide, the key top 14 and the sheet member 60 disposed on the membrane switch 50 collide, and the link members 16 and 18 during the keystroke operation. When at least one of the collisions with the sheet member 60 occurs, the lowering operation of the key top 14 reaches the limit, that is, the key top 14 is disposed at the lower end position of the keystroke (FIG. 3). The pair of contacts 42 and 44 of the membrane switch 50 are closed by the actuating member 52 as described above until the key top 14 reaches the lower end position. At this time, since the key top 14 and the base 12 are both made of a relatively hard and lightweight resin material, the structure is such that noise is likely to occur during a mutual collision. Further, since the sheet member 60 and the membrane switch 50 are both thin film members and are installed on the relatively hard support plate 56, the key top 14 and the link members 16, 18 collide with the sheet member 60. Sometimes noise is likely to occur.

  Therefore, the key switch device 10 according to the present invention includes a silencer that reduces the sound generated by the collision between the members described above when the key top 14 reaches the lower end position. As shown in FIG. 1, the silencer of the key switch device 10 includes an elastically deformable buffer portion 64 provided in association with the operation member 52 of the switch mechanism 20. The buffer portion 64 is configured to be elastically deformed immediately before the key top 14 reaches the lower end position of the key stroke, during a normal key stroke operation of the key switch device 10.

  In the illustrated embodiment, the buffer portion 64 includes a pair of elastic pieces 64 that are formed to slightly protrude from the surface of the sheet member 60 to which the operation member 52 is fixed. When the key top 14 reaches the lower end position, these elastic pieces 64 are at least of the two pairs of pivot portions 26 of the key top 14 and the first and second arms 28 and 30 of the pair of link members 16 and 18. One of them is formed at a position where it can collide, and the thickness of the sheet member 60 is locally increased at that position. As a result, at least one of the key top 14 and the pair of link members 16 and 18 collides with the elastic pieces 64 immediately before the key top 14 reaches the lower end position of the keystroke stroke. Therefore, the elastic piece 64 acts to buffer the collision itself when at least one of the collision between the key top 14 and the sheet member 60 and the collision between each link member 16, 18 and the sheet member 60 occurs. , Thereby effectively reducing the impact sound. Further, because of this buffering action, the pressing speed of the key top is slightly reduced immediately before the key top 14 and the base 12 collide, and as a result, the collision between the key top 14 and the base 12 is also alleviated. .

  In the illustrated embodiment, the pair of elastic pieces 64 is disposed adjacent to a connection portion between the dome opening end 52 b of the operating member 52 and the surface of the sheet member 60. Therefore, when the actuating member 52 is fixed to the separate sheet member 60 via the adhesive 62, the rubber-based adhesive is used as the adhesive 62, and at the same time, as shown in FIG. A pair of elastic pieces 64 can be formed by extending a rubber adhesive from the annular fixing region to be fixed to a side in a rectangular shape. In this case, the rubber-based adhesive extending laterally from the fixing region is solidified in parallel with the fixing process of the actuating member 52, and becomes an elastic piece 64 having sufficient elasticity to function as a silencer. Such a configuration is advantageous because the elastic piece 64 can be formed from the same rubber adhesive simultaneously with the step of disposing the adhesive 62 in the fixing region on the surface of the sheet member 60. In the preferred embodiment, the adhesive 62 and the elastic piece 64 are made of a silicone rubber adhesive. Moreover, the arrangement | positioning process of the adhesive agent 62 and the elastic piece 64 can be implemented by well-known screen printing, for example.

  In the above configuration, as shown as a modification in FIG. 6, the pair of elastic pieces 64 can be formed thicker than the adhesive 62 in the fixing region. In this case, the pair of elastic pieces 64 can be formed by repeatedly applying a rubber-based adhesive by well-known screen printing only at the corresponding portions. Further, as described above, when the actuating member 52 and the sheet member 60 are formed integrally with each other, the pair of elastic pieces 64 are attached to the sheet member 60 at the same positions as described above in the integral molding process. It can be formed integrally. In any configuration, the thickness of the elastic piece 64 can be selected in a range that does not interfere with the contact closing action by the normal keying operation of the key switch device 10 and can reduce the collision sound between members as much as possible.

  According to the key switch device 10 having the above-described configuration, the key top 14 reaches the lower end position during a normal key-pressing operation only by performing a slight processing on the sheet member 60 to form the elastic piece 64 having a slight thickness. It is possible to easily install a silencer that reduces the collision noise. In addition, since the structural changes of the components other than the sheet member 60 having the elastic piece 64 are not required, it affects the keystroke stroke amount of the key switch device 10, the total height when not operated and pressed, the keystroke operability, and the like. Therefore, it is possible to effectively reduce the noise during the keystroke operation.

  FIG. 7 shows an exploded perspective view of a key switch device 70 according to a second embodiment of the present invention. The key switch device 70 has substantially the same configuration as that of the key switch device 10 described above except for the configuration of the silencer that reduces the collision sound generated when the key top 14 reaches the lower end position. These components are denoted by common reference numerals, and the description thereof is omitted.

  The silencer of the key switch device 70 includes an elastically deformable buffer portion 72 provided in association with the operating member 52 of the switch mechanism 20. The buffer portion 64 is configured to be elastically deformed immediately before the key top 14 reaches the lower end position of the key stroke, during a normal key stroke operation of the key switch device 70. In the illustrated embodiment, the buffer portion 72 includes an elastic auxiliary member 72 that is additionally attached to the dome top portion 52 a of the actuating member 52. Preferably, the elastic auxiliary member 72 is made of a material having a smaller elastic modulus than the rubber material of the actuating member 52, and is filled in a recess 52c provided on the dome top 52a of the actuating member 52 as shown in FIG. In this case, the elastic auxiliary member 72 can be formed by, for example, injecting a molten polymer material into the recess 52c of the operating member 52 and solidifying it. Alternatively, the disk-shaped elastic auxiliary member 72 formed in a separate process can be fitted into the recess 52 c of the operating member 52. In the preferred embodiment, the actuating member 52 and the elastic auxiliary member 72 are made of silicone rubber having different hardness.

  As will be described later, the elastic auxiliary member 72 having such a configuration has a predetermined keying operation characteristic obtained by the operation member 52 during normal keying operation of the key switch device 70, particularly after the contacts 42 and 44 are closed. It acts to change the characteristics until the key top 14 reaches the lower end position. As a result, when at least one of the collision between the key top 14 and the base 12, the collision between the key top 14 and the sheet member 60, and the collision between each link member 16, 18 and the sheet member 60 occurs, the collision itself Is buffered by the presence of the elastic auxiliary member 72, so that the collision noise is effectively reduced.

  In general, in a key switch device, a dome-shaped actuating member used as a switch opening / closing means also acts as an urging means for elastically urging the key top upward away from the base, and when the key top is deformed by a keystroke operation. Due to the dome shape, an upward biasing force (elastic recovery force) corresponding to the amount of displacement of the key top is applied to the key top. In other words, when the key top depression amount exceeds a predetermined value, a keystroke operation characteristic is obtained such that the urging force that has been gradually increased until then suddenly decreases. As a result, the operator can sensuously recognize that the key switch device has been operated accurately even in a keyboard of a portable electronic device that generally has a relatively short keystroke stroke.

  Referring to the key switch device 70, as shown in FIG. 9A, as the key top 14 (FIG. 7) is pushed down from the upper end position of the keystroke stroke, first, the dome top 52a and the dome opening of the operating member 52 are opened. The dome-shaped side wall portion 52d extending between the end 52b is elastically deformed. Then, before the key top 14 reaches the lower end position of the key stroke, the pressing portion 58 of the operating member 52 presses the sheet substrate 46 of the membrane switch 50 and closes the contacts 42 and 44. Therefore, the characteristic keying operation characteristic of the key switch device 70 until the contact is closed, that is, the upward biasing force applied by the operating member 52 to the key top 14 is mainly exerted by elastic deformation of the side wall portion 52d. .

  The shape of the dome top portion 52a of the actuating member 52 enables the key top 14 to be further pushed down to the lower end position after the contacts 42 and 44 of the membrane switch 50 are closed. That is, during this time, as shown in FIG. 9B, the top wall portion 52e that defines the recess 52c in the dome top portion 52a of the actuating member 52 is elastically deformed together with the side wall portion 52d. This elastic deformation of the top wall portion 52e exerts a large upward biasing force on the key top 14, whereby the operator can perceive the contact closure sensuously. Moreover, since the key top 14 can be pushed down more elastically after the contact is closed, there is an advantage that the impact applied to the finger of the operator is alleviated.

  In the key switch device 70, the upward urging force exerted on the key top 14 from the closing of the contact to reaching the lower end position is somewhat increased by filling the concave portion 52c of the operating member 52 with the elastic auxiliary member 72. It is said. As a result, the collision speed when at least one of the collision between the key top 14 and the base 12, the collision between the key top 14 and the sheet member 60, and the collision between each link member 16, 18 and the sheet member 60 occurs is reduced. Therefore, as described above, the collision sound is effectively reduced. The keystroke operation characteristics of such a key switch device 70 are schematically shown in FIG. In FIG. 9C, the horizontal axis is the pressing distance (mm) from the upper end position of the key top 14, the vertical axis is the pressing force (g) applied to the key top 14, and the broken line is equipped with the elastic auxiliary member 72. The keystroke operation characteristics of the key switch device that is not provided and the solid line indicate the keystroke operation characteristics of the key switch device 70 equipped with the elastic auxiliary member 72.

  In the above configuration, as shown as a modification in FIG. 10, a plurality of granular elastic auxiliary members 74 can be filled in the recess 52 c of the operating member 52. In this case, these elastic auxiliary members 74 may be simply packed in the recess 52c, or may be fixed using an adhesive. FIG. 10 illustrates a structure in which the operation member 52 and the sheet member 60 are integrally formed with each other. 8 and 10, the elastic auxiliary member 74 makes the collision sound between the members as much as possible without impairing the operation feeling after closing the contact by the normal key-pressing operation of the key switch device 70. The size, shape, elastic modulus, and the like can be selected so that they can be reduced.

  According to the key switch device 70 having the above-described configuration, the key top 14 is brought into the lower end position during a normal key-pressing operation by performing only a slight process for filling the concave portions 52c of the operation member 52 with the elastic auxiliary members 72 and 74. It is possible to easily install a silencer that reduces the collision noise when it reaches. Moreover, since the structure of the components other than the operation member 52 having the elastic auxiliary members 72 and 74 is not required to be changed, it affects the keystroke stroke amount of the key switch device 70, the total height when not operated and pressed, the keystroke operability, and the like. The noise during the keystroke operation can be effectively reduced without affecting

  By the way, when the switch mechanism 20 of the key switch devices 10 and 70 according to each of the above embodiments includes the operation member 52 and the sheet member 60 formed integrally with each other as illustrated in FIG. The member 60 is also formed from the same rubber material as the operation member 52. Therefore, in this case, unlike the separate sheet member 60 made of PET or the like, the rubber sheet member 60 itself can act in the same manner as the elastic piece 64 described above to provide a silencing effect. However, in this configuration, the rubber sheet member 60 is likely to bend and stretch when the key switch devices 10 and 70 are assembled. As a result, the operation member 52 is installed at a predetermined position in the central opening 22 of the base 12. Tend to be difficult. If the actuating member 52 is not installed at a predetermined position in the base 12, not only the keystroke operability of the key top 14 is impaired, but there is a concern that it is difficult to accurately open and close the contacts 42 and 44 of the membrane switch 50. This problem becomes more prominent as an attempt is made to reduce the thickness of the seat member 60 integrated with the actuating member 52 in order to promote a reduction in the height of a keyboard incorporating a large number of key switch devices 10 and 70.

  Therefore, as shown in FIG. 11 as a third embodiment, a key switch device 80 can be provided that further includes a positioning mechanism that positions the actuating member 52 at a predetermined position in the central opening 22 of the base 12. Since the key switch device 80 has substantially the same configuration as the key switch device 10 described above except that this positioning mechanism is installed in association with each of the base 12 and the sheet member 60, the same or similar configuration. Elements are denoted by common reference numerals and description thereof is omitted. Note that the key switch device 80 does not include the above-described elastic piece 64 on the sheet member 60 because the key switch device 80 uses a silencing effect by the rubber sheet member 60 itself integrated with the operation member 52.

  The base 12 of the key switch device 80 includes a pair of extending portions 82 extending in a direction approaching each other from a pair of front and rear opposing inner peripheral surfaces 12 c that define the central opening 22. Support surfaces 84 extending in a substantially semicircular and concave shape are formed on the surfaces of the extension portions 82 that face each other. Further, the sheet member 60 includes a pair of protrusions 86 that are provided on the same side as the operation member 52 at positions facing each other with the operation member 52 interposed therebetween. Engaging surfaces 88 extending in a substantially semicircular and convex manner are formed on the surfaces of the protrusions 86 that are separated from each other. The pair of support surfaces 84 provided on the base 12 and the pair of engagement surfaces 88 provided on the sheet member 60 have shapes that can be brought into close contact with each other and are disposed at corresponding positions.

  In the assembly process of the key switch device 80, when the base 12 is further arranged on the sheet member 60 integrated with the operation member 52 arranged on the membrane switch 50, the correspondence between each support surface 84 of the base 12 and the sheet member 60. Are engaged with each other in close contact with each other. At this time, since each support surface 84 and each engagement surface 88 extend in a substantially semicircular shape, the base 12 and the sheet member 60 are positioned and locked to each other at least in the front-rear direction and the left-right direction of the key switch device 80. Acts as follows. As a result, the operation member 52 is easily and accurately installed at a predetermined position in the central opening 22 of the base 12. Since the membrane switch 50 is formed of a material that is relatively difficult to stretch, the contacts 42 and 44 can be easily disposed at predetermined positions in the central opening 22 of the base 12. Therefore, the operation member 52 is accurately positioned with respect to the contacts 42 and 44 of the membrane switch 50.

  In the above configuration, in order to further facilitate the positioning of the base 12 on the sheet member 60, the upper edge of each protrusion 86 of the sheet member 60 that first engages each extension 82 of the base 12 is chamfered. Is advantageous. The positioning mechanism is not limited to the above-described configuration, and various other shapes and configurations of positioning mechanisms can be used as long as the base 12 and the sheet member 60 can be positioned relative to each other in at least the front-rear direction and the left-right direction of the key switch device 80. Needless to say, it can be adopted.

  12 and 13 are enlarged views of the key switch device 90 according to the fourth embodiment of the present invention, in particular, the portion of the silencer. The key switch device 90 can have substantially the same configuration as that of the key switch device 10 described above except for the configuration of a silencer that reduces the collision sound that occurs when the key top 14 reaches the lower end position. Therefore, the same or similar components are denoted by common reference numerals and description thereof is omitted. FIG. 12 is a schematic plan view showing a part of a large base material 12 ′ corresponding to the base 12 of two key switch devices 90 arranged side by side in a keyboard having a large number of key switch devices 90. FIG. 13 is a longitudinal sectional view along the line XIII-XIII showing the same part together with the key top 14. The link members 16 and 18, the operation member 52, and the sliding engagement portion 24 of the base 12 shown in FIG.

  The muffling means of the key switch device 90 includes an elastically deformable buffer portion 92 provided in association with the base 12. The buffer unit 92 is configured to collide with the key top 14 immediately before the key top 14 reaches the lower end position when the key switch device 90 is operated normally. In the illustrated embodiment, the buffer portion 92 includes a plurality of leaf spring portions 92 formed on the base 12. The leaf spring portions 92 are arranged in a distributed manner at a desired position corresponding to the outer edge region of the key top 14 above the base 12.

  Each leaf spring portion 92 includes a T-shaped portion formed by partially cutting the base material 12 ′ across the bases 12 of two adjacent key switch devices 90. Each leaf spring portion 92 is integrally connected to the base member 12 ′ at the base end of the T-shaped leg 92 a, and can be elastically swung on the base member 12 ′ using this connecting portion as a fulcrum. . Each free end of the T-shaped arm 92b of the leaf spring portions 92 extends to a position corresponding to the outer corners of the key top 14, preferably above the base 12, in each of the adjacent key switch devices 90. Then, at each free end of the T-shaped arm 92b of each leaf spring portion 92, a protrusion 94 is formed that slightly protrudes (for example, about 0.1 mm) from the main surface 12a of the base 12 in each key switch device 90. . The membrane switch 50 and the support plate 56 in each key switch device 90 are formed with openings 96 and 98 that can receive the swinging leaf spring portions 92 at positions corresponding to the leaf spring portions 92, respectively. The

  According to the above-described configuration, when the key switch device 90 is normally operated to perform the keystroke operation, the key top 14 is in the four corners of the back surface 14c or when the key top 14 is inclined immediately before reaching the lower end position of the keystroke stroke. At least in one corner, it collides with a corresponding protrusion 94 on each leaf spring portion 92 (shown in broken lines in FIG. 13). Each leaf spring portion 92 elastically swings with respect to the base 12 by this collision and is received in the lower openings 96 and 98, and in this state, the key top 14 reaches the lower end position. By such elastic deformation of each leaf spring portion 92, the collision between the base 12 and the key top 14 is alleviated, thereby effectively reducing the collision sound. In addition, because of this buffering action, the pressing speed of the key top 14 is reduced immediately before the key top 14 and the link members 16 and 18 (FIG. 1) collide with the sheet member 60 (FIG. 1). The collision between these members is also alleviated.

  14 and 15 are enlarged views of the key switch device 100 according to the fifth embodiment of the present invention, in particular, the silencing means. The key switch device 100 can have substantially the same configuration as that of the key switch device 10 described above except for the configuration of a silencer that reduces the collision sound that occurs when the key top 14 reaches the lower end position. Therefore, the same or similar components are denoted by common reference numerals and description thereof is omitted. FIG. 14 is a schematic plan view showing a part of a large base material 12 ′ corresponding to the bases 12 of two key switch devices 100 arranged side by side in a keyboard having a large number of key switch devices 100. FIG. 15 is a longitudinal sectional view along the line XV-XV showing the same portion together with the key top 14. The link members 16 and 18 and the sliding engagement portion 24 of the base 12 shown in FIG.

  The muffling means of the key switch device 100 includes an elastically deformable buffer portion 102 provided in association with the base 12. The buffer unit 102 is configured to collide with the key top 14 immediately before the key top 14 reaches the lower end position when the key switch device 100 is operated normally. In the illustrated embodiment, the buffer portion 102 includes a plurality of elastic members 102 installed in a plurality of through holes 104 formed in the base 12. The elastic members 102 are distributed at desired positions corresponding to the outer edge region of the key top 14 above the base 12.

  Preferably, each through hole 104 is arranged at a position corresponding to the four corners of the outer edge of the key top 14 above the base 12 in each of the adjacent key switch devices 100. Each elastic member 102 is formed of, for example, the same rubber material as that of the operation member 52, is received through each through hole 104 through a sufficient gap, and slightly (for example, 0. 0. 0) from the main surface 12a of the base 12 at the tip. It protrudes about 1mm). In the case where the operation member 52 and the sheet member 60 described above are formed integrally with each other, the elastic member 102 can be formed integrally with the sheet member 60 in the integral molding process. (FIG. 15). Alternatively, when the actuating member 52 and the sheet member 60 are separate bodies, the elastic member 102 molded in a separate process is fixed to a position corresponding to each through hole 114 on the surface of the sheet member 60 with an adhesive or the like. Can be formed.

  According to the above configuration, during normal keystroke operation of the key switch device 100, the key top 14 collides with the corresponding elastic member 102 at four corners or at least one corner of the back surface 14c immediately before reaching the lower end position of the keystroke stroke. (Indicated by broken lines in FIG. 15). Each elastic member 102 is elastically crushed in the through hole 104 of the base 12 by this collision, and in this state, the key top 14 reaches the lower end position. By such elastic deformation of each elastic member 102, the collision itself between the base 12 and the key top 14 is mitigated, thereby effectively reducing the collision sound. Further, because of this buffering action, the pressing speed of the key top 14 is reduced immediately before the key top 14 and the link members 16 and 18 (FIG. 1) collide with the sheet member 60. Collisions will be mitigated.

  FIGS. 16 and 17 are enlarged views of the key switch device 110 according to the sixth embodiment of the present invention, in particular, the portion of the silencer. The key switch device 110 can have substantially the same configuration as that of the key switch device 10 described above except for the configuration of a silencer that reduces the collision sound that occurs when the key top 14 reaches the lower end position. Therefore, the same or similar components are denoted by common reference numerals and description thereof is omitted. FIG. 16 is a schematic plan view showing a part of a large base material 12 ′ corresponding to the bases 12 of two key switch devices 110 arranged side by side in a keyboard having a large number of key switch devices 110. FIG. 17 is a longitudinal sectional view along the line XVII-XVII showing the same part together with the key top 14. The link members 16 and 18 and the sliding engagement portion 24 of the base 12 shown in FIG.

  The muffling means of the key switch device 110 includes an elastically deformable buffer portion 112 provided in association with the base 12. The buffer portion 112 is configured to collide with the key top 14 immediately before the key top 14 reaches the lower end position when the key switch device 110 is operated normally. In the illustrated embodiment, the buffer 112 includes a plurality of elastic members 112 installed in a plurality of through holes 114 formed in the base 12. The elastic members 112 are distributed at desired positions corresponding to the outer edge region of the key top 14 above the base 12.

  Preferably, each through hole 114 is disposed at a position corresponding to the four corners of the outer edge of the key top 14 above the base 12 in each of the adjacent key switch devices 110. Each elastic member 112 is formed of, for example, the same rubber material as that of the operation member 52, and is disposed below the base 12 to define the bottom surface of each through hole 114. In the case where the operation member 52 and the sheet member 60 described above are formed integrally with each other, the elastic member 112 can be formed from portions overlapping the respective through holes 114 of the sheet member 60 itself ( FIG. 17). Alternatively, when the actuating member 52 and the sheet member 60 are separate bodies, the elastic member 112 molded in a separate process is fixed to a position corresponding to each through hole 114 on the surface of the sheet member 60 with an adhesive or the like. Can be formed. On the other hand, the key top 14 is provided with protrusions 116 that can be received in the through holes 114 of the base 12 at the four corners of the inner surface 14a. Each protrusion 116 has a height slightly larger (for example, about 0.1 mm) than the thickness of the base 12 around each through hole 114.

  According to the above-described configuration, during normal key-pressing operation of the key switch device 110, the key top 14 has four or at least one corner projections 116 on the back surface 14c immediately before reaching the lower end position of the key-stroke stroke. Enters and collides with the elastic member 112 (indicated by a broken line in FIG. 17). Each elastic member 112 is elastically crushed under the through hole 114 of the base 12 by this collision, and the key top 14 reaches the lower end position in this state. By such elastic deformation of each elastic member 112, the collision itself between the base 12 and the key top 14 is mitigated, thereby effectively reducing the collision sound. Further, because of this buffering action, the pressing speed of the key top 14 is reduced immediately before the key top 14 and the link members 16 and 18 (FIG. 1) collide with the sheet member 60. Collisions will be mitigated.

  According to the key switch devices 90, 100, and 110 according to each of the above embodiments, since the buffer portions 92, 102, and 112 are formed at the collision portion between the base 12 and the key top 14, the amount of keystroke stroke, non-operation It is possible to effectively reduce the noise during the keystroke operation without affecting the overall height at the time of pressing and pressing, the keystroke operability, and the like. From the same viewpoint, it is possible to reduce noise during a keystroke operation by providing a silencer having a simpler configuration at a collision point between the base 12 and the keytop 14. FIG. 18 shows a key switch device 120 according to a seventh embodiment of the present invention having such a silencer with a simple configuration. The key switch device 120 can have substantially the same configuration as the key switch device 10 described above, except for the configuration of the silencer. Therefore, the same or similar components are denoted by common reference numerals and description thereof is omitted. 18A is a schematic plan view of the base 12 and the key top 14 of the key switch device 120, and FIG. 18B is a longitudinal sectional view taken along line XVIII-XVIII. The link members 16 and 18, the switch mechanism 20 and the support plate 56 shown in FIG.

  The muffling means of the key switch device 120 includes a collision unit 122 provided locally on at least one of the base 12 and the key top 14. The base 12 and the key top 14 are configured to collide with each other via the collision unit 122 when the key top 14 reaches the lower end position during a normal keystroke operation of the key switch device 120. In the illustrated embodiment, the collision portion 122 includes protrusions 122 formed at the four corners of the back surface 14 c of the key top 14. Each protrusion 122 protrudes slightly (for example, about 0.1 mm) from the back surface 14 c of the key top 14. Such a protrusion 122 can be integrally formed from the same material as the key top 14 in the molding process of the key top 14.

  According to the above configuration, at the time of a normal keystroke operation of the key switch device 120, the key top 14 has the four corners or at least one corner projection 122 collide with the main surface 12 a of the base 12 at the lower end position of the keystroke stroke. At this time, the area of the mutual collision portion is extremely small due to the action of the protrusion 122. As a result, the collision sound between the base 12 and the key top 14 is reduced as compared with the configuration in which the planes collide with each other. However, in this configuration, since the contact of the switch mechanism 20 needs to be closed when the key top 14 collides with the protrusion 122, the total height when the key switch device 120 is not operated and when the key switch device 120 is pushed down is slightly increased. Affected.

  In the above configuration, as shown as a modification in FIG. 19, instead of providing the protrusions 122 on the key top 14, a plurality of protrusions 124 that act as collision portions can be formed on the main surface 12 a of the base 12. These protrusions 124 are formed so as to slightly protrude (for example, about 0.1 mm) from the main surface 12 a of the base 12 at positions corresponding to the four corners of the outer edge of the key top 14 above the base 12. Such a protrusion 124 can be integrally formed from the same material as the base 12 in the molding process of the base 12.

  According to such a configuration, at the time of normal keystroke operation of the key switch device 120, the key top 14 has the four corners or at least one corner of the back surface 14 c at the lower end position of the keystroke stroke to the corresponding protrusions 124 formed on the base 12. collide. Therefore, as in the configuration of FIG. 18, the impact noise between the base 12 and the key top 14 is reduced by reducing the area of the mutual collision portion compared to the configuration in which the planes collide with each other.

  Alternatively, as shown in FIG. 20 as another modified example, instead of providing the protrusions 122 and 124 on the base 12 or the key top 14, the back surface 14 c of the key top 14 is inclined and the outer peripheral edge 126 of the key top 14 is made to collide with It can also be configured as. In this case, at the time of normal keystroke operation of the key switch device 120, the key top 14 collides with the main surface 12 a of the base 12 at all or at least a part of the outer peripheral edge 126 at the lower end position of the keystroke. Therefore, the collision sound between the base 12 and the key top 14 is reduced as compared with the configuration in which the planes collide with each other. With this configuration, the risk of affecting the overall height when the key switch device 120 is not operated and pressed down is eliminated.

  The silencing means in each of the above embodiments can be used not only independently but also in combination with several silencing means as required. In addition, a keyboard incorporating a large number of key switch devices 10, 70, 80, 90, 100, 110, 120 according to any of the embodiments is extremely excellent in quietness during a keystroke operation.

  FIG. 21 is an exploded perspective view showing the key switch device 130 according to the eighth embodiment of the present invention, FIG. 22 is a sectional view of the key switch device 130 taken along the line XXII-XXII at the time of assembly, and FIG. It is sectional drawing along line XXIII-XXIII of the key switch apparatus 130 at the time. The key switch device 130 includes a base 132, a key top 134 that is disposed on the main surface 132 a of the base 132 so as to be movable up and down, and that has an operation surface 134 a that can be tapped with a finger of an operator, and the key top 134 A pair of link members 16 and 18 that guide and support in the up-and-down direction, and a switch mechanism 136 that opens and closes the contacts of the electric circuit corresponding to the up-and-down operation of the key top 134 are configured. The key switch device 130 has substantially the same configuration as the key switch device 10 described above except that the key switch device 130 includes locking means that substantially prevents the key top 134 from moving in at least one horizontal direction on the base 132. Therefore, the same or similar components are denoted by common reference numerals, and the description thereof is omitted.

  The switch mechanism 136 of the key switch device 130 includes a membrane switch 50 and an operating member 52 that can move laterally below the key top 134. The actuating member 52 is fixedly connected to a sheet member 138 that is slidably disposed in the direction of arrow A between the base 132 and the membrane switch 50 at the dome opening end 52b. As a result, the operating member 52 urges the key top 134 to the upper end position of the keystroke stroke within the central opening 140 of the base 132 and elastically deforms as the key top 134 moves up and down (FIG. 22). And a second position (FIG. 24) that maintains the initial dome shape without exerting an urging force on the key top 134, and is movable in the horizontal direction. The actuating member 52 may be configured to be fixed to a separate sheet member 138 with an adhesive, or may be formed integrally with the sheet member 138.

  In a keyboard constructed by arranging a large number of such key switch devices 130, the operating members 52 of all the key switch devices 130 are arranged at the first position when in use, so that all the key tops 134 can be operated to be pressed. It can be held in the position (corresponding to the upper end position of the keystroke stroke), and when not in use (for example, when it is carried), the operation members 52 of all the key switch devices 130 are arranged at the second position, The key tops 134 can be collectively displaced to a retracted position (corresponding to the lower end position of the keystroke) that is lower than the protruding position and cannot be depressed. When the actuating member 52 is placed in the second position, the key top 134 is lowered by its own weight under the guidance of the link members 16 and 18, and is automatically displaced from the protruding position to the retracted position. The actuating member 52 in the second position is accommodated in the internal space of the key top 134 while maintaining its initial dome shape.

  Therefore, in a keyboard incorporating a large number of key switch devices 130, it is possible to displace the key top 134 quickly and accurately by smoothly shifting the operation member 52 of each key switch device 130 to the side. It is important from the viewpoint of improving operability. Therefore, the key switch device 130 is provided with a locking means for substantially preventing the key top 134 from moving in at least one horizontal direction on the base 132, whereby the actuating member 52 is moved between the first position and the second position. It enables to move smoothly between. As will be described in detail below, the locking means of the key switch device 130 is provided on the pair of first walls 142 provided on the base 132 and the key top 134 and is slidably engaged with the first walls 142. A pair of second walls 144 is formed.

  The base 132 is a frame-like member having a substantially rectangular central opening 140 that is shielded by the key top 134. The base 132 has two sets of sliding engagement portions 146 and 148 along the pair of opposed inner peripheral surfaces 132b that define the central opening portion 140 in the front-rear direction (left and right direction in FIG. 22, the same applies hereinafter). They are spaced apart. Each sliding engagement portion 146, 148 has a wall portion protruding from the main surface 132a and the inner peripheral surface 132b of the base 132 and extends in an L shape, and is substantially parallel to the main surface 132a inside the wall portion. The first guide grooves 146a and 148a extending in the first direction and the second guide grooves 146b and 148b that are arranged in parallel with the first guide groove 146a and extend upwardly by bending are formed. The first guide grooves 146a and 148a of the sliding engagement portions 146 and 148 slide the support shafts 38 provided at the second ends of the arm portions 28 and 30 of the first and second link members 16 and 18, respectively. Accept freely. The second guide grooves 146b and 148b of the sliding engagement portions 146 and 148 are slidably engaged with the upper surfaces of the arm portions 28 and 30 of the first and second link members 16 and 18, respectively. .

  The set of sliding engagement portions 146 arranged on the front side of the base 132 is fixedly provided with a protrusion 150 extending upward at the rear end of each L-shaped wall portion. Each protrusion 150 has a flat rear end surface 142 extending in a direction substantially orthogonal to the main surface 132 a, and the rear end surface 142 acts as the first wall 142. The pair of sliding engagement portions 146 on the front side arrange the first and second guide grooves 146 a and 146 b and the first wall 142 at corresponding positions along the pair of inner peripheral surfaces 132 b of the base 132. The pair of sliding engagement portions 148 on the rear side arrange the first and second guide grooves 148 a and 148 b at corresponding positions along the pair of inner peripheral surfaces 132 b of the base 132. Further, the sliding engagement portions 146 and 148 on the corresponding side in each set are aligned in the front-rear direction along the inner peripheral surface 132 b of the base 132.

  The key top 134 is a dish-shaped member having a substantially rectangular planar shape, and two sets of pivot attachment portions 152 are formed in parallel with each other on the inner surface 134b opposite to the operation surface 134a. Each pivot portion 152 is formed of a plate-like piece projecting upright from the inner surface 134b of the key top 134, and extends in a direction substantially perpendicular to the inner surface 134b through a bearing hole 152a penetrating in the plate thickness direction. A notch 152b communicating with 152a is formed. The bearing hole 152a of each pivoting portion 152 rotatably receives the support shaft 40 provided at the first end of each arm portion 28, 30 of each of the first and second link members 16,18. The two pivoting portions 152 constituting each pair are separated from each other by a distance capable of receiving the first and second arm portions 28 and 30 of the link members 16 and 18 in the center region in the front-rear direction of the inner surface 134b of the key top 134. The bearing holes 152a are positioned so as to align with each other in the axial direction thereof. Further, the pivoting portions 152 on the corresponding side in each set are aligned in the front-rear direction on the inner surface 134 b of the key top 134.

  Each of the pair of pivot portions 152 disposed on the front side of the key top 134 has a flat front end surface 144 extending in a direction substantially orthogonal to the inner surface 134b. The front end surface 144 functions as the second wall 144. Then, it slidably engages with the first wall 142 of the base 132 (FIG. 23). Further, a pressing portion 154 that transmits a pressing force applied to the key top 134 to the operating member 52 of the switch mechanism 136 is provided in a projecting manner in a substantially central region of the inner surface 134b of the key top 134 (FIG. 22). The pressing portion 154 includes a lower-end pressing surface 154a extending substantially parallel to the inner surface 134b of the key top 134, and a rear-end sliding surface 154b extending in a tapered manner from the inner surface 134b to the pressing surface 154a. The pressing surface 154a of the pressing portion 154 engages with the dome top portion 52a of the operating member 52 during normal key-pressing operation of the key switch device 130, loads the operating member 52 with a pressing force, and applies an urging force from the operating member 52. Receive. The sliding surface 154b of the pressing portion 154 is slidably engaged with the dome-shaped side wall portion 52d of the operating member 52 while moving the operating member 52 between the first position and the second position. .

  In the key top 134, the first and second link members 16, 18 swing in opposite directions in synchronization with the respective support shafts 40, and the respective support shafts 38 move in a substantially horizontal direction along the base 132. By sliding, the base surface 132 moves in a substantially vertical direction while maintaining a predetermined substantially horizontal posture in which the operation surface 134a is disposed substantially parallel to the main surface 132a. During this time, the key top 134 is allowed to slightly rattle in the front-rear direction. Therefore, the first wall 142 provided in the sliding engagement portions 146 on the front side of the base 132 and the pivots on the front side of the key top 134 are supported. The second wall 144 provided on the wearing portion 152 engages in a sliding manner while allowing the generation of a minute gap between them.

  The upper end position of the keystroke stroke of the key top 134 is such that the first and second link members 16, 18 slide in the direction of mutual approach of the respective support shafts 38, and the sliding engagement portions 146, 148 of the base 132 move in the first direction. It is defined when it is locked by a wall portion that defines one guide groove 146a, 148a (FIG. 23). As the key top 134 descends from the upper end position, the respective support shafts 38 of the first and second link members 16 and 18 slide in a mutually separating direction substantially perpendicular to the ascending / descending direction of the key top 134. When the key top 134 reaches the lower end position of the key stroke, the first and second link members 16 and 18 are received on the inner surface 134b side of the key top 134 and received in the opening 140 of the base 132.

  In the key switch device 130 having the above-described configuration, when the key top 134 is displaced from the protruding position where the keystroke operation is possible to the retracting position where the keystroke operation is impossible, the operating member 52 at the first position shown in FIG. It is moved backward together with 138 (right in the figure). During the movement of the actuating member 52, the key top 134 is moved so that the pushing surface 154 a of the pushing part 154 slides on the dome top part 52 a of the actuating member 52 away from the dome top part 52 a, and then the pushing part 154 slides. While the surface 154b slides on the side wall portion 52d of the operating member 52, the surface 154b is lowered in the vertical direction by its own weight. Then, after the key top 134 reaches the retracted position (lower end position), the operating member 52 is detached from the pressing portion 154 and reaches the second position shown in FIG.

  On the contrary, when the key top 134 is displaced from the retracted position to the protruding position, the operating member 52 in the second position is moved forward (leftward in the drawing) together with the sheet member 138. Along with this forward movement, the actuating member 52 causes the dome-shaped side wall portion 52d to engage with the inclined sliding surface 154b of the pressing portion 154 of the key top 134, so that the pressing force is applied to the key top 134 obliquely upward. Effect. The key top 134 is lifted in the vertical direction by the pressing force under the guiding action of the link members 16 and 18. During this time, the first wall 142 provided on both sliding engagement portions 146 on the front side of the base 132 and the second wall 144 provided on both pivotal attachment portions 152 on the front side of the key top 134 are slidably engaged. Thus, the key top 134 is substantially prevented from moving forward on the base 132. Then, after the key top 134 reaches the protruding position (upper end position), the actuating member 52 reaches the first position.

  While the operating member 52 moves forward while pushing up the key top 134, as shown in FIG. 25, just before the pressing portion 154 of the key top 134 rides on the dome top portion 52a of the operating member 52, the key top 134 is added. There is a tendency that the pressing force obliquely upward increases. At this time, if the forward movement of the key top 134 is not prevented by the engagement of the first wall 142 and the second wall 144, the upper surfaces of the first and second arm portions 28, 30 of the first link member 16 are It is pressed more than necessary against the wall surface of the second guide groove 146b of both sliding engagement portions 146 on the front side. As a result, the first link member 16 acts as a lever, pressing the sheet substrate 46 of the membrane switch 50 downward at its sliding end (second end), and the movement of the operating member 52 is hindered. become. However, in the key switch device 130, as described above, the first wall 142 and the second wall 144 are engaged while the key top 134 is raised in the vertical direction, so that the first link member 16 has a lever action. Therefore, the operating member 52 can smoothly move from the second position to the first position.

  FIG. 26 is a partially cutaway perspective view of a keyboard 160 according to an embodiment of the present invention provided with a large number of key switch devices 130 arranged therein. The keyboard 160 includes a large base 132 ′, a sheet member 138 ′, a membrane switch 50 ′, and a support plate 56 ′ that are common to all the key switch devices 130. The sheet member 138 ′ is provided with the operation member 52 fixed at a position corresponding to each key switch device 130, and by operating a pair of knobs 162 provided on one side edge of the keyboard 160, the seat member 138 ′ Direction). The sliding engagement portions 146 and 148 in each key switch device 130 are not shown.

  Such a keyboard 160 can quickly and accurately displace all the key switch devices 130 between the use form and the non-use form, and is extremely excellent in operability. For example, in a keyboard incorporating 90 key switch devices not provided with the locking means described above, a force of about 3000 g is required to displace all the key switch devices from the non-use form to the use form at once. On the other hand, it was confirmed that with the keyboard 160 incorporating the 90 key switch devices 130, all the key switch devices 130 can be collectively moved from the non-use form to the use form with a force of about 300 g.

  FIG. 27 shows an exploded perspective view of a key switch device 170 according to a ninth embodiment of the present invention. The key switch device 170 is configured such that the locking means for substantially preventing the key top 134 from moving in at least one horizontal direction on the base 132 is configured to substantially prevent the key top 134 from moving backward. Has substantially the same configuration as the key switch device 130 described above, the same or similar components are denoted by the same reference numerals, and the description thereof is omitted.

  The locking means of the key switch device 170 is provided on the front first wall 142 and the rear first wall 172 provided on the base 132 and the key top 134, and is slidably engaged with each of the first walls 142 and 172. The front second wall 144 and the rear second wall 174 are combined. More specifically, the base 132 is similar to the protrusion 150 of each sliding engagement portion 146 disposed on the front side, and the front end of the L-shaped wall portion of each sliding engagement portion 148 disposed on the rear side. Further, a protrusion 176 extending upward is fixedly provided. Each protrusion 176 has a flat front end surface 172 extending in a direction substantially orthogonal to the main surface 132a, and the front end surface 172 functions as the rear first wall 172. The key top 134 has a flat rear end surface 174 in which each pivoting portion 152 disposed on the rear side extends in a direction substantially orthogonal to the inner surface 134b, similarly to each pivoting portion 152 disposed on the front side. The rear end surface 174 acts as the rear second wall 174 and slidably engages with the rear first wall 172 of the base 132.

  The key top 134 translates in a substantially vertical direction with respect to the base 132 under the guidance of the first and second link members 16 and 18. During this time, the key top 134 is slidably engaged with the front first wall 142 and the rear first wall 172 of the base 132 and the front second wall 144 and the rear second wall 174 of the key top 134, respectively. , Rattling in the front-rear direction is reduced as much as possible. As a result, the key switch device 170 can realize an accurate contact opening / closing operation under an accurately guided keystroke stroke even when used in a messy keystroke operation or an inclined posture.

It is a disassembled perspective view of the key switch apparatus by the 1st Embodiment of this invention. It is sectional drawing along line II-II at the time of the assembly of the key switch apparatus of FIG. 1, and shows the state which has a key top in the upper end position of a keystroke. It is sectional drawing of the key switch apparatus corresponding to FIG. 2, and shows the state which has a key top in the lower end position of a keystroke. It is an expanded sectional view of the switch mechanism in the key switch apparatus of FIG. It is an expansion perspective view of the sheet | seat member which has a silencer in the key switch apparatus of FIG. It is an expansion perspective view of the sheet member which has a silencing means by a modification. It is a disassembled perspective view of the key switch apparatus by the 2nd Embodiment of this invention. It is an expanded sectional view of the switch mechanism which has a silencer in the key switch apparatus of FIG. It is a figure explaining the effect | action of the muffling means of FIG. 8, (a) An expanded sectional view at the time of contact closing, (b) An expanded sectional view in the lower end position of a keystroke stroke, (c) A graph which shows a keystroke operation characteristic. It is an expanded sectional view of the switch mechanism which has a silencing means by a modification. It is a disassembled perspective view of the key switch apparatus by the 3rd Embodiment of this invention. It is a schematic plan view which shows a part of base of the keyboard provided with the key switch apparatus by the 4th Embodiment of this invention. FIG. 13 is a partially enlarged longitudinal sectional view taken along line XIII-XIII of the keyboard of FIG. It is a schematic plan view which shows a part of base of the keyboard provided with the key switch apparatus by the 5th Embodiment of this invention. FIG. 15 is a partially enlarged longitudinal sectional view taken along line XV-XV of the keyboard of FIG. 14. It is a schematic plan view which shows a part of base of the keyboard provided with the key switch apparatus by the 6th Embodiment of this invention. FIG. 17 is a partially enlarged longitudinal sectional view taken along line XVII-XVII of the keyboard of FIG. 16. It is the partial enlarged longitudinal cross-sectional view along (a) schematic plan view and (b) line XVIII-XVIII of the key switch apparatus by the 7th Embodiment of this invention. It is the (a) schematic plan view and (b) the partial expanded longitudinal cross-sectional view along line XIX-XIX of the key switch apparatus by a modification. It is the (a) schematic plan view and (b) the partial expanded longitudinal cross-sectional view along line XX-XX of the key switch apparatus by another modification. It is a disassembled perspective view of the key switch apparatus by the 8th Embodiment of this invention. It is sectional drawing along line XXII-XXII at the time of the assembly of the key switch apparatus of FIG. 21, The state which has a key top in a protrusion position is shown. It is sectional drawing along line XXIII-XXIII at the time of the assembly of the key switch apparatus of FIG. 21, The state which has a key top in a protrusion position is shown. It is sectional drawing of the key switch apparatus corresponding to FIG. 22, and shows the state which has a key top in a retracted position. FIG. 23 is a cross-sectional view of the key switch device corresponding to FIG. 22, showing a state in which the key top is at an intermediate position between the protruding position and the retracted position. FIG. 22 is a partially cutaway perspective view of a keyboard incorporating the key switch device of FIG. 21 according to an embodiment of the present invention. It is a disassembled perspective view of the key switch apparatus by the 9th Embodiment of this invention.

Explanation of symbols

10, 70, 80, 90, 100, 110, 120, 130, 170 Key switch device 12, 132 Base 14, 134 Key top 16 First link member 18 Second link member 20, 136 Switch mechanism 24 Sliding engagement portion 26 Pivoting part 42, 44 Contact 50 Membrane switch 52 Actuating member 56 Support plate 60, 138 Sheet member 62 Adhesive 64 Elastic piece 72, 74 Elastic auxiliary member 92 Leaf spring part 102, 112 Elastic member 122, 124, 126 Colliding part 142, 172 first wall 144, 174 second wall 160 keyboard

Claims (16)

A base and a key top disposed on the base, each of which interlocks with each other and operatively engages both the base and the key top to guide and support the key top on the base in the up-and-down direction. A key switch device comprising a pair of link members and a switch mechanism that opens and closes a contact of an electric circuit in response to a lifting operation of the key top.
Comprising a muffling means for reducing a collision sound generated when the key top reaches the lower end position of the lifting stroke;
A key switch device characterized by.   2. The key switch device according to claim 1, wherein the silencer includes an elastically deformable buffer provided in the switch mechanism, and the buffer is elastically deformed immediately before the key top reaches the lower end position.   The switch mechanism is disposed in an opening provided in the base below the key top, and is disposed on the membrane switch having the contact, and is elastically deformed as the key top moves up and down. And an actuating member that presses the membrane switch and closes the contact while the key top moves toward the lower end position, and the buffer portion is provided in association with the actuating member. Key switch device.   The actuating member is connected to a sheet member disposed on the membrane switch, and the buffer portion is formed from an elastic piece protruding from the sheet member adjacent to a connecting portion between the actuating member and the sheet member. The key switch device according to claim 3, wherein at least one of the key top and the pair of link members collides with the elastic piece immediately before the key top reaches the lower end position.   The key switch device according to claim 4, wherein the operating member is fixed to the sheet member via a rubber adhesive, and the elastic piece is formed of the rubber adhesive.   The key switch device according to any one of claims 3 to 5, wherein the operating member is a dome-shaped member made of a rubber material, and the buffer portion is additionally formed on the top of the dome of the operating member.   The key switch device according to claim 6, wherein the buffer portion is made of an elastic auxiliary member attached to the top of the dome of the operating member, and the elastic auxiliary member is made of a material having a smaller elastic modulus than the rubber material.   The key switch device according to claim 3, further comprising a positioning mechanism that positions the operating member at a predetermined position in the base.   The sound deadening means comprises an elastically deformable buffer portion provided in association with the base, and the key top collides with the buffer portion immediately before the key top reaches the lower end position. The key switch device according to any one of the preceding claims.   10. The key switch according to claim 9, wherein the buffer portion includes a plurality of leaf spring portions formed on the base, and the leaf spring portions are distributed at positions corresponding to outer edge regions of the key top. apparatus.   The said buffer part consists of several elastic members installed in the several recessed part formed in the said base, and these elastic members are disperse | distributed and arrange | positioned in the position corresponding to the outer edge area | region of the said key top. 10. The key switch device according to 10.   The muffler comprises a collision part locally provided on at least one of the key top and the base, and collides with the base via the collision part when the key top reaches the lower end position. The key switch device according to any one of 1 to 11. A base and a key top disposed on the base, each of which interlocks with each other and operatively engages both the base and the key top to guide and support the key top on the base in the up-and-down direction. A key switch device comprising a pair of link members and a switch mechanism that opens and closes a contact of an electric circuit in response to a lifting operation of the key top.
Locking means for substantially preventing movement of the key top on the base in at least one horizontal direction;
A key switch device characterized by.   14. The key switch according to claim 13, wherein the locking means includes a first wall provided on the base and a second wall provided on the key top and slidably engaged with the first wall. apparatus.   The switch mechanism is disposed in an opening provided in the base below the key top, and is disposed on the membrane switch having the contact, and the key top moves toward the lower end position. An operating member that presses the membrane switch in between to close the contact, and the operating member biases the key top to the upper end position and elastically deforms as the key top moves up and down. The key switch device according to claim 13 or 14, wherein the key switch device is movable in a horizontal direction between the key top and a second position that retains the initial shape without exerting an urging force on the key top.   A keyboard configured by arranging a number of the key switch devices according to claim 1.

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