JP2582312Y2 - Key switch - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a key switch used for a keyboard of an input device such as a word processor and a personal computer.

[0002]

2. Description of the Related Art Conventionally, as a key switch in this kind of keyboard, as disclosed in Japanese Patent Application Laid-Open Nos. 60-89011 and 60-60217, etc.
A stem protruding downward on the lower surface of the key top is inserted into a stem guide portion formed on the holder member to guide and support it so that it can move vertically, and a rubber spring having a contact portion on the lower surface is arranged below the stem. A key switch is generally used in which a switching member such as a membrane switch having an electric contact formed on a flexible sheet is disposed at a lower end of the rubber spring.

The prior art disclosed in Japanese Patent Laid-Open No. 60-60 / 1985.
In the key switch of Japanese Patent No. 217, when one end of a key top such as a space key having a larger planar shape than a contact portion is pressed, the key top moves up and down in parallel without tilting. It has been proposed that halfway portions of a pair of link members arranged in an X shape in a side view are rotatably connected to each other, and the pair of link members are arranged between the lower surface of the keytop and the holder member.

[0004]

[Problems to be Solved by the Invention] In the above prior arts,
Since the key top is guided and supported by the stem and the stem guide portion, if the keystroke is lengthened, the amount of overlap between the stem and the stem guide becomes shorter, and the upper and lower slides are twisted. Therefore, there is a problem that the stem and the stem guide must be lengthened, and the keyboard cannot be made thin. In order to solve this problem, the present applicant has previously disclosed in Japanese Patent Application No. 3-330160 a first link and a second link in which guide means for vertically moving a key top are arranged in an X-shape in a side view. And one of the free ends of the first link and the second link is rotated by the lower surface of the key top and the holder member. It has been proposed to lock the rubber spring slidably in the substantially horizontal direction and to press the head of the rubber spring against the lower surface near the intersection of the two links. .

In this technique, the lower free end of one link is rotatably locked to the locking portion of the holder member, so that when the keytop is pressed, the two links are centered on the locking portion. Because the midway crossing part turns downward,
Lateral displacement occurs at the abutting portion between the upper surface of the head of the rubber spring located thereunder and the halfway intersection. Since the head of the rubber spring is made of rubber, the sliding friction with the pressing portion increases, so that the rubber spring is not subjected to a pressing force that buckles the outer peripheral dome substantially uniformly, and the rubber spring seats. The bending deformation is uncertain and non-uniform, so that the key operation feeling is deteriorated, and the friction of the rubber spring is increased due to the friction, so that the durability is deteriorated.

The purpose of the present invention is to solve this problem.

[0007]

In order to achieve the above object, the present invention provides a guide means for guiding and supporting the vertical movement of a key top by connecting and locking the lower surface of the key top and a holder member below the key top. A key-shaped rubber spring which is elastically deformable through the guide means by the key-top up / down input operation via the guide means, and a switching unit which performs a switching operation by elastic deformation of the rubber spring; Is formed by a first link and a second link which are arranged in an X-shape in a side view, and the two links are rotatably connected at an intermediate crossing portion thereof, and the free ends of the first link and the second link are formed. One of the parts is rotatably locked to the lower surface of the key top and the holder member, and the other is slidably locked to the horizontal in a substantially horizontal direction. The configured so as to press at a lower surface of the intersection near the both links, and the head top surface of the rubber spring, and forming a small sliding layer friction coefficient.

[0008]

Next, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a side sectional view of a key switch, in which a key switch 1 has a key top 2 and a first key switch.
A guide means 3 in which a link 4 and a second link 5 are arranged in an X shape in side view, a cap-shaped rubber spring 6 pressed by the guide means 3, and a synthetic resin for supporting the guide means 3 Member 7, a flexible printed board 9 stretched on the lower surface of the holder member 7 so that the switching portions 29, 29 (see FIGS. 6 and 7) face the mounting hole 7a of the holder member 7, and Reinforcing plate 1 stretched on the lower side
It consists of 0.

As shown in FIGS. 1, 6 and 8, the rubber spring 6 is provided in the mounting hole 7a of the holder member 7 so as to cover the switching portions (electric contact portions) 29, 29 on the printed circuit board 9. To be inserted and arranged. The rubber spring 6 according to the present invention is made of an electrically insulating silicone rubber or EPDM (ethylene propylene diene methylene) or the like.
a frusto-conical dome portion 6b extending downward from the periphery of a
And a thick-walled flange 6c extending substantially horizontally and radially outward on the outer periphery of the dome portion 6b, and is integrally formed into a downward-opening cap shape. When the keytop is depressed, contact points of the switching parts 29, 29 are provided on the lower surface of the head 6a of the rubber spring 6 pressed by the lower surface pressing part 26 of the connecting intersection between the first link 4 and the second link 5. A movable contact portion 30 made of conductive rubber having conductivity for electrically turning on and off both switching portions in contact with the portion is fixed. The entire rubber spring 6 may be formed to have conductivity by dispersing and filling conductive particles such as carbon black in silicone rubber.

On the upper surface of the head 6a of the rubber spring 6, a film made of a synthetic resin having a small friction coefficient such as polytetrafluoroethylene or polyvinyl fluoride is stretched, or the synthetic resin is applied. The sliding layer 31 formed by the above is provided (see FIGS. 1 and 8). This sliding layer 3
In step 1, when the links 4 and 5 are pressed from the pressing portion 26, an unreasonable force such as twisting or twisting is applied to the head 6a.

The key top 2 formed of a synthetic resin such as an ABS resin is provided with characters such as numerals, letters and the like by engraving or printing on the upper surface (surface) thereof. Key top 2
A longitudinal groove-shaped slide for locking the pin portions 11a, 11b on the upper free end side of the first link 4 to be described later in a substantially horizontal direction so as to be slidable in the front-rear direction of the key top 2. The locking portions 16, 16 and the hole-shaped rotation locking portions 15, 15 for locking the pin portions 13 a, 13 b at the upper free end of the second link 5 only for rotation are integrally provided. The pair of left and right locking members 17, 17 having the front and rear lengths are integrally formed or bonded to each other with an adhesive or the like to protrude (see FIG. 5).

Referring to FIGS. 4A and 4B, a first link 4 and a second link 4 made of a synthetic resin such as a glass fiber reinforced synthetic resin.
The link 5 will be described in detail. FIG. 4A shows the first link 4.
FIG. 4B is a plan view of the second link 5.
The first link 4 is formed integrally with the base 18 and the upper and lower free ends 19 and 20 in a substantially H-shape in plan view. The base 18 has a support hole 21 penetrating in a horizontal direction on a side surface thereof. Pin portions 12a, 12b are provided on the side surfaces of the arm portions 20a, 20b extending from both left and right ends of the lower free end portion 20, respectively.
Is projected sideways, and a pin 1 is provided on the side of the upper free end 19.
1a and 11b are protruded sideways.

The second link 5 is also formed integrally with the base 22 and the upper and lower free ends 23 and 24 into a substantially H shape in plan view. One side of the base 22 has a support shaft 25
The support shaft 25 is inserted into the support hole 21 of the first link 4, and the first link 4 and the second link 5 are rotatably connected around the support shaft 25. Arm 2 extending from both left and right ends of lower free end 24 of second link 5
Pin portions 14a and 14b are provided on the side surfaces of the upper free end 23 on the side surfaces of the pin portions 13a and 14b, respectively.
a, 13b are protruded sideways.

In this embodiment, when viewed from the side, the first
The distance from the center line of the support hole 21 in the link 4 to the center line of the upper and lower pin portions 11a and 12a and the second link 5
From the center line of the support shaft 25 at the pin portions 13a, 14a
Are formed so that the distances to each other are equal. With this configuration, as described later, the key top 2 is rotated by the guide means 3 about the pin portions 12a and 12b on the lower free end side of the first link 4 so that the key top 2 is fixed to the holder member 7. It can move up and down in parallel to the upper surface.

FIGS. 6 and 7 show a part of a holder member 7 made of a synthetic resin such as a glass fiber reinforced synthetic resin. The holder member 7 has a flange 6c at the lower end of the rubber spring 6 having the cap shape. Is provided with a substantially rectangular mounting hole 7a which can be inserted without being displaced, and a pair of left and right rotation locking portions 27 and front and rear longitudinal groove-shaped sliding members are provided on both right and left side edges of the mounting hole 7a. The stop portion 28 is integrally injection-molded so that the locking portions 27, 28 are opened downward. The lower end side pin portions 12a, 12b of the first link 4 are rotatably fitted into the rotation locking portions 27, 27, respectively.
The pin portions 14a, 14b on the lower end side of the second link 5 are fitted into the sliding locking portions 28, 28 so as to slide back and forth.

At this time, the pin portions 11a, 11b and 14
a, 14b and the shape of the sliding locking portions 16, 28 are as follows:
The first link 4 and the second link 5 are substantially immovable in the left-right direction in FIG. 5, and the pin portions 11a and 14a of FIG.
It is determined so as not to hinder the sliding in the middle left and right directions. More specifically, in the present embodiment, the tip of each pin portion slides substantially in contact with the outer side surface of the corresponding sliding engagement portion. Therefore, the support shaft 25 is prevented from coming out of the support hole 21.

With this configuration, when the key top 2 is pressed down, the first link 4 rotates downward about the rotation locking portion 27 of the holder member 7, so that the first link 4 and the second link 5 are rotated. The pressing portion 26, which is a halfway crossing portion that is rotationally connected in an X-shape in a side view, has a head 6 of the rubber spring 6.
The sliding layer 31a is pressed obliquely downward. Therefore, even if a horizontal external force is applied to the head 6a of the rubber spring, the pressing portion 26 presses the surface of the sliding layer 31 while sliding, so that an unnatural force for twisting or twisting the head 6a acts. Instead, the entire dome portion 6b of the rubber spring 6 is substantially uniformly buckled and deformed by the pressing of the key top 2, and the key operation feeling is improved.

When the soft rubber head 6a is locally pressed by the pressing portion of the link, only the local portion is easily dented and deformed, but the sliding layer 31 is formed into a film having high rigidity. When it is stretched on the upper surface of the head 6a, a pressing force acts on substantially the entire head 6a to prevent local deformation, and the entire dome 6b of the rubber spring 6 is substantially uniform by pressing the key top 2. As a result, the key operation feeling is improved, and the switching operation to the switching unit 29 is also ensured. Further, the smooth sliding between the pressing portion and the rubber spring by the sliding layer 31 reduces the wear of the head portion 6a, thereby improving the durability of the rubber spring.

In another embodiment shown in FIG. 9, a thin film made of a synthetic resin having a low coefficient of friction similar to that described above is formed on the ring body 32 as a sliding layer, and the top surface of the head 6a is stretched with an adhesive. Set up. When the ring body 32 is pressed by the pressing portions (intermediate crossing portions) of the links 4 and 5, when the rubber spring 6 is pressed downward as far as possible (in FIG. (Refer to (b)), the soft head 6a is elastically deformed upward by the reaction force of the movable contact 30 on the lower surface of the head 6a pressed against the surface of the printed board 9 or the reinforcing plate 10, and the deformed portion is a ring body. Since it can protrude into the space on the inner diameter side of the key 32, the reaction force applied to the key top 2 and further to the fingertip in the pushed-off state is softened, and an excellent effect that the impact of the key touch at the time of the pushed-off state can be reduced can be achieved.

The pressing portion 26 formed by the first link 4 and the second link 5 is connected to the base portions 18 and 22 of the two links 4 and 5.
Of course, the lower surface side may be formed so as to have a downwardly convex polygonal flat surface. When formed on the pressing portion 26 having a large number of flat surfaces, the upper surface of the head 6a can be formed at any time during the stroke of the key top. Since the upper surface of the sliding layer 31 is simultaneously pressed by a plurality of different area regions, the buckling deformation of the rubber spring can be made more uniform. Further, a substrate such as a membrane switch circuit board may be used in place of the flexible printed board 9 forming the switching section 29, and the present invention is also applicable to a variable capacity keyboard.

[0021]

[Operation and effect of the present invention] In short, in the present invention, the key top is supported by the vertical movement guide with respect to the holder member.
Since a sliding layer having a small friction coefficient is provided on the upper surface of the head of the rubber spring located below the intersection of the first link and the second link cross-connected in an X shape in a side view, the vicinity of the intersection is provided. The smooth sliding between the pressing portion and the rubber spring has the effect of reducing wear of the head of the rubber spring and improving the durability of the rubber spring.

If the sliding layer is formed on a synthetic resin film and stretched on the upper surface of a soft rubber head, a pressing force acts on substantially the entire head, thereby preventing local deformation. As a result, the entire rubber spring is substantially uniformly buckled and deformed by the pressing of the key top, so that the key operation feeling is improved and the switching operation to the switching section is also ensured.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a key switch.

FIG. 2 is a side sectional view of the key switch in a pressed-off state.

FIG. 3 is a bottom view of the key top.

4A is a plan view of a first link, and FIG. 4B is a plan view of a second link.

FIG. 5 is a sectional view taken along the line VV of FIG. 1;

FIG. 6 is a plan view of a rubber spring and a mounting hole.

FIG. 7 is a perspective view of a mounting hole of a holder member.

FIG. 8 is a sectional view of a rubber spring.

9A is a cross-sectional view of another embodiment of the sliding layer, FIG.
FIG.

[Explanation of symbols]

 2 Key Top 4 1st Link 5 2nd Link 6 Rubber Spring 6a Head 6b Dome 6c Flange 7 Holder 7a Mounting Hole 9 Printed Circuit Board 10 Reinforcement 11a, 11b, 12a, 12b Pin 13a, 13b, 14a, 14b Pin part 15, 27 Rotation locking part 16, 28 Sliding locking part 25 Support shaft 26 Pressing part 29 Switching part 30 Movable contact part 31 Sliding layer 32 Ring body

Claims (1)

(57) [Scope of request for utility model registration] 1. A guide means for connecting and locking to a lower surface of a key top and a holder member therebelow to guide and support the vertical movement of the key top, and the guide means by an up / down input operation by the key top. In a key switch including a cap-shaped rubber spring elastically deformable through a switch and a switching unit that performs a switching operation by elastic deformation of the rubber spring, the guide unit is provided with a first link cross-shaped in a side view X-shape. A first link and a free end of each of the first link and the second link are connected to a lower surface of the key top and a holder member. And the other is slidably engaged in a substantially horizontal direction, and the head of the rubber spring is pressed against the lower surface near the intersection of the two links. Form, and the head top surface of the rubber spring, a key switch, characterized in that the formation of the small sliding layer friction coefficient.