push-button switch device

Abstract

Key switch device comprising: a base (1) having an opening (10) in a central part of the base; a light guide (2) having an elastic body receiving section (26), wherein the light guide (2) is supported by the base (1) such that it is arranged in the opening (10); an attached push button (3) which is able to approach and detach from the base (1) in order to cover the light guide (2); an elastic body (4) arranged between the elastic body receiving section (26) and a lower surface of the probe (3), wherein the elastic body (4) prestresses the probe (3) in a separation direction in which the probe (3) is separated from the base (1); a fixed contact piece (41) having a fixed contact (47), wherein the fixed contact piece (41) is attached to the base (1); and a movable contact piece (42) attached to the base (1), which has a movable contact (58) that is to be brought into contact with the fixed contact (47) when the push button (3) is moved towards the base (1) in an approach direction in which the push button (3) approaches the base (1).

Description

FIELD OF TECHNOLOGY

[0001] The present disclosure mainly relates to a key switch device used for a keyboard. STATE OF THE ART

[0002] Conventionally, a known key switch device, for example, is a keyboard switch in which a cylindrical guide pin protrudes from a socket, a light guide is guided on the inner diameter side of the guide pin, and a coil spring arranged on the outer diameter side elastically supports a button so that the button can be pushed in (see, for example, PTL 1). LIST OF CITIONSPATENT LITERATURE

[0003] PTL 1: CN 1 04 851 727 A Further prior art is represented by CN 2 04 390 951 U, which shows a keyboard switch with a base, a return spring, a static contact, a movable contact spring and a light guide column, whereby the keyboard switch is intended to improve the pressing feeling. SUMMARY OF THE INVENTION TECHNICAL TASK

[0004] However, in a conventional push-button switch device, a guide pin is required, and this correspondingly increases the surface area occupied in plan view. Furthermore, the light guide protrudes from an upper surface of the base, and the height dimension is large.

[0005] It is an object of the present invention to provide a key switch device capable of realizing a reduction in height while reducing the space occupied in plan view. SOLUTION TO THE TASK

[0006] As a means for achieving the above object, the present disclosure provides a key switch device comprising: a base having an opening in a central base portion; a light guide having an elastic body receiving portion, the light guide being supported by the base so as to be disposed in the opening; an attached button capable of approaching and separating from the base to cover the light guide; an elastic body disposed between the elastic body receiving portion and a lower surface of the button, the elastic body biasing the button in a separation direction in which the button is separated from the base; a fixed contact piece having a fixed contact, the fixed contact piece being attached to the base; and a movable contact piece attached to the base, the movable contact having a movable contact to be brought into contact with the fixed contact when the button is moved toward the base in an approach direction in which the button approaches the base. ADVANTAGEOUS EFFECTS OF THE INVENTION

[0007] With the present disclosure in which the light guide is arranged in the opening of the base and the elastic body is directly pressed against the elastic body receiving portion, it is possible to realize a height reduction and thereby reduce the area occupied in plan view of the key switch device. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view of a key switch device according to the present embodiment. Fig. 2 is a perspective view showing a state in which a button made of Fig. 1 was removed. Fig. 3 is an exploded perspective view of the Fig. 1 shown key switch device. Fig. 4A is a perspective view of the base in Fig. 3. Fig. 4B is a perspective view of Fig. 4A in bottom view. Fig. 5A is a perspective view of the light guide in Fig. 3 in top view. Fig. 5B is a perspective view of the light guide in Fig. 5A in bottom view. Fig. 6A is a perspective view of the button in Fig. 3 in top view. Fig. 6B is a perspective view of the button in Fig. 6B in bottom view. Fig. 7A is a perspective view of the fixed contact piece in Fig. 3. Fig. 7B is a perspective view of the fixed contact piece in Fig. 7A when viewed from a different angle. Fig. 8A is a perspective view of the movable contact piece in Fig. 3. Fig. 8B is a perspective view of the movable contact piece in Fig. 8A when viewed from a different angle. Fig. 9A is a perspective view of the slider in Fig. 3. Fig. 9B is a perspective view of the slider in Fig. 9A when viewed from a different angle. Fig. 10 is a front sectional view of the Fig. 1 shown key switch device. Fig. 11 is a perspective sectional view of the Fig. 1 shown key switch device. DESCRIPTION OF THE EMBODIMENTS

[0008] Fig. 1 is a perspective view showing the entire key switch device according to the present embodiment. Fig. Fig. 2 is a perspective view showing a state in which a button 3 of Fig. 1 was removed. Fig. 3 is an exploded perspective view of the key switch device in Fig. 1. The push button switch device includes a base 1, a light guide 2, a button 3, a coil spring 4, a contact opening and closing mechanism 5, a slider 6, and a lifting mechanism 7.

[0009] As in the Fig. 4A and Fig. 4B, the base 1, which is made of, for example, a synthetic resin material, comprises a bottom portion 8 and a rectangular frame portion 9.

[0010] The bottom portion 8 includes an opening 10 having a circular shape in plan view. An annular locking receiving portion 11 is formed on an inner peripheral surface of the opening 10 in a central part of the inner peripheral surface of the opening 10 in the up / down direction. Locking claws 29a of the light guide 2 are locked to the locking receiving portion 11, as described later.

[0011] A first bracket 12 and a second bracket 13 are formed near the opening 10. A first locking groove 14 extending in the up / down direction is formed in a side surface of the first bracket 12. A first terminal hole 15 continuing the first locking groove 14 and communicating with a lower surface of the groove is formed on the bottom portion 8. The first bracket 12 includes a first locking ridge 16 having an upper surface configured as a convex arc surface. The second bracket 13 has a similar structure to the first bracket 12. The second bracket 13 includes a second locking groove 17 and a second locking ridge 18. A second terminal hole 19 communicating with the second locking groove 17 is formed on the bottom portion 8. A fixed contact piece 41 is fixed to the first bracket 12, and a movable contact piece 42 is fixed to the second bracket 13.A recess 20a, which has a rectangular shape in plan view, is formed in a central portion of an upper surface of a side portion of the bottom portion 8. A recess 20b is formed at each of four corners of the bottom portion 8. When the button 3 is depressed, the lower end of an abutment portion 36 of the button 3 (described later) abuts against the bottom surface of the recess 20b, so that further movement of the button 3 in a direction orthogonal to the bottom portion 8 is restricted.

[0012] The rectangular frame portion 9 includes two pairs of opposite side walls 21a and 21b. A flange portion 22 is formed on the outer side of the side walls 21a and 21b. The flange portion 22 serves as a support for the lifting mechanism 7, described later. A deformation prevention wall 23 is formed on the outer side of the flange portion 22 on the outer side of the opposite side walls 21a. The deformation prevention wall 23 prevents a first arm 67 and a second arm 69 from being laterally depressed. A recessed portion 24 is formed in a central portion of the outer surface of each opposite side wall 21a. Each recessed portion 24 includes a narrow groove 24a and a relief recess 24b that is wider than the groove 24a. The narrow groove 24a is formed by an upper half of a side wall 21a, and the relief recess 24b is formed by a lower half of a side wall 21a.The width of the groove 24a is set so that the first arm 67 and the second arm 68, which will be described later, can be inserted in a folded state.

[0013] As in the Fig. 5A and Fig. 5B, the light guide 2, which is formed by molding a translucent resin material, includes a light guide main body 25 having a truncated conical shape, and an elastic body receiving portion 26 projecting in the radial direction from a lower end portion of the light guide main body 25.

[0014] A plurality of convex lenses 25a are formed on the top surface of the light guide main body 25. The convex lenses 25a scatter light from an LED (light-emitting diode) 25b (see Fig. 5B), which is a light source.

[0015] The elastic body receiving portion 26, which has a flange-like shape, includes a receiving portion main body 27 of the upper half (i.e., a portion close to the light guide main body 25) and a cylindrical body 28 of the lower half (i.e., a portion far from the light guide main body 25). Notches 26a are formed at equal intervals at three positions in the circumferential direction in the elastic body receiving portion 26, and corresponding claw portions 29 are formed therein. The receiving portion main body 27 and the cylindrical body 28 are divided into three arcuate parts by the notches 26a. The receiving portion main body 27 has an outer diameter larger than the opening 10 of the base 1. A lower surface of the receiving portion main body 27 abuts against the upper surface of the bottom portion 8.The outer surface of the cylindrical body 28 abuts the inner surface of the opening 10 to position the light guide 2 in the radial direction relative to the base 1. An LED 25b is arranged in a recess 30 surrounded by the lower surface of the receiving portion main body 27 and the inner surface of the cylindrical body 28. Each claw portion 29 extends downward with the cylindrical body 28, respectively. In a head portion of each claw portion 29, an engaging claw 29a is formed, projecting toward the outer diameter side. Each of the engaging claws 29a engages with the engaging receiving portion 11 formed in the opening 10 of the base 1, preventing the light guide 2 from disengaging upward from the opening 10.

[0016] As in the Fig. 6A and Fig. As shown in Figure 6B, the button 3, made of, for example, a synthetic resin material, has a rectangular shape in plan view. The button 3 includes a flat plate portion 31, side wall portions 32 each extending downward from two opposite sides of the flat plate portion 31, and extension portions 33a and 33b projecting laterally from the remaining two sides of the flat plate portion 31.

[0017] A cylindrical spring guide portion 34 is formed in a central portion of a lower surface (i.e., a surface facing the base 1) of the flat plate portion 31. A guide wall 35 is provided on the lower surface of the flat plate portion 31 on three sides. On the opposite walls on both sides of the guide wall 35, abutment portions 36 are formed at both end portions, which protrude more than the other part. The opposite walls protrude inward except at both end portions. In the opposite parts of the abutment portions 36, which are arranged at both ends of the guide wall 35, guide grooves 36a are formed respectively, which are configured to guide the slider 6. One of the side walls constituting the respective guide groove 36a is undercut except in the upper and lower portions. A lifting projection 37 is formed in a lower end portion of one of the side walls.Each lifting projection 37 includes a lower inclined surface 37a which gradually rises upwards and an upper flat surface 37b.

[0018] At both end portions of each side wall portion 32, bearing holes 38 are formed, extending further downward. In each bearing hole 38, the first arm 67 and a first axle shaft portion 71 of the second arm 68, which will be described later, are rotatably and slidably supported.

[0019] A projection 39 with a concave circular arc surface is formed at three positions in an extension portion 33a. A side edge of the flat plate portion 31 and an arc surface of the projection 39 constitute a support portion 40 configured to support a balance bar (not shown).

[0020] How to continue in Fig. As can be seen in Figure 3, the coil spring 4 is arranged between the elastic body receiving portion 26 of the light guide 2 and the spring guide portion 34 of the button 3. The coil spring 4 biases the button 3 upward relative to the base 1 (i.e., in a direction orthogonal to the bottom portion 8 of the base 1 and away from the base 1).

[0021] The contact opening and closing mechanism 5 includes a fixed contact piece 41 and the movable contact piece 42, which are formed by pressing and bending a sheet of copper alloy.

[0022] As in the Fig. 7A and Fig. 7B, the fixed contact piece 41 includes: a first flat portion 43; a fixed terminal portion 44 extending downward from a central portion of a lower edge of the first flat portion 43; a second flat portion 45 extending orthogonally from one end side of a lower edge of the first flat portion 43; a third flat portion 46 extending from one end edge of the second flat portion 45; a fixed contact 47 provided on the third flat portion 46; and a fourth flat portion 48 extending orthogonally from the other end edge of the flat portion 43 and opposite to the third flat portion 46.A first locking projection 49, extending from the first flat surface portion 43, is formed in a central portion of the fixed terminal portion 44. The first locking projection 49 is engaged with the first locking groove 14 formed in the first bracket 12 of the base 1. The fixed terminal portion 44 is press-fitted into the first terminal hole 15 and protrudes from a lower surface of the bottom portion 8. A first locking recess 50 cut out in a circular arc shape is formed in a central portion of a lower edge of the fourth flat surface portion 48. The first locking recess 50 is engaged with the first locking bead 16 of the first bracket 12.

[0023] As in the Fig. 8A and Fig. 8B, the movable contact piece 42 includes: a first flat portion 51; a movable terminal portion 52 extending downward from one end side of a lower edge of the first flat portion 51; a second flat portion 53 extending orthogonally from one end of the first flat portion 51; and a third flat portion 54 extending orthogonally from the other end of the first flat portion 51 and partially opposite to the second flat portion 53. A second locking projection 55 extended to the first flat portion 51 is formed in a central part of the movable terminal portion 52. A second locking recess 56 cut out in a circular arc shape is formed in a central portion of a lower edge of the second flat portion 53.The second locking recess 56 is engaged with the second locking bead 18 of the first bracket 12. A protruding piece 57 (an example of a pressing receiving portion) bent into a substantially C-shaped cross section is formed in a central portion of an upper edge of the third flat portion 54. The protruding piece 57 is pressed by a pressing portion 59 of the slider 6 described later and elastically deforms the third flat portion 54 (and also the first flat portion 51). A movable contact 58 is provided on the outer end surface of the third flat portion 54.

[0024] As in the Fig. 9A and Fig. As shown in Fig. 9B, the slider 6 is made of, for example, a synthetic resin material and has a flat plate shape. The slider 6 includes the pressing portion 59 at a central part. The pressing portion 59 includes a first inclined surface 60 that gradually protrudes from a lower side by a predetermined amount toward the upper edge, and a concave surface 61 that continues the first inclined surface 60 and in which the center of the protruding portion is slightly recessed. The pressing portion 59 further includes a second inclined surface 62 in which the protrusion amount gradually decreases at the lower end side of the protruding portion.

[0025] The slider 6 further includes guided projections 64 in both ends. Each guided projection 64 is formed to divide a central portion of the outer surface of the flat portion 65 provided at both end portions of the slider 6 into two left and right parts. A guided projection 64 is inserted into a guide groove 36 formed in the push button 3 and guided to move up and down. A raised projection 66 is formed on one lower side of the two parts divided by the guided projection 64 of the flat portion 65. An upper surface of the raised projection 66 is an inclined surface 66a that gradually projects downward, and a lower surface is a flat surface 66b. The flat surface 37b of the raised projection 37 abuts against the flat surface 66b of the raised projection 66 and is lifted when the push button 3 moves upward.

[0026] As again in Fig. As seen in Fig. 3, the lifting mechanism 7 includes the first arm 67 and the second arm 68. The first arm 67 and the second arm 68 have substantially the same shape and each include an axle shaft 69 and arm portions 70 extending from both end portions thereof. The first axle shaft portions 71 are formed at both end portions of the axle shaft 69. An inwardly projecting second axle shaft portion 72 and a first projection 73 are formed on the end side of one arm portion 70. A bearing hole 74 through which the second axle shaft portion 72 is rotatably inserted and an inwardly projecting second projection 75 are formed on the end side of the other arm portion 70.

[0027] The first arm 67 and the second arm 68 are coupled to each other by inserting the second axle shaft portion 72 of the first arm 67 into the support hole 74 of the second arm 68, and inserting the second axle shaft portion 72 of the second arm 68 into the support hole 74 of the first arm 67. With the first arm 67 and the second arm 68 coupled to each other, the coupled portion is inserted into the groove 24a of the base 1 in a folded state and spread at the relief recess 24b, so that the first projection 73 and the second projection 75 abut against an upper surface constituting the relief recess 24b, and detachment of the base 1 is prevented. The first arm 67 and the second arm 68, which are coupled to each other, are coupled to the probe 3 by inserting the first axle shaft portions 71 into the bearing holes 38 of the probe 3.The movement of the button 3 in the projecting direction is restricted by the first axle shaft portions 71 abutting the inner edge of the bearing holes 38. The movement of the button 3 in the pushing direction is restricted by the lower end of the abutting portion 36 abutting the bottom surface of the recess 20b of the base 1.

[0028] Next, a method for assembling the key switch device having the above structure will be described.

[0029] The light guide 2 is arranged in the opening 10 of the base 1. The cylindrical body 28 of the light guide 2 is inserted into the opening 10 so that the flange portion 22 abuts the upper surface of the bottom portion 8 of the base 1. As a result, the locking claws 29a of the claw portions 29 engage the locking receiving portion 11 of the opening 10, and the light guide 2 is attached to the base 1.

[0030] The coil spring 4 is arranged around the light guide 2 positioned in the opening 10 of the base 1. In such a state, the lower end portion of the coil spring 4 abuts the elastic body receiving portion 26 of the light guide 2.

[0031] The fixed contact piece 41 is attached to the first bracket 12 of the socket 1, and the movable contact piece 42 is attached to the second bracket 13. The fixed contact piece 41 is attached to the socket 1 by press-fitting the fixed terminal portion 44 into the first terminal hole 15 of the socket 1, engaging the first locking projection 49 with the first locking groove 14 of the first bracket 12, and engaging the first locking recess 50 with the first locking bead 16 of the first bracket 12. The movable contact piece 42 is attached to the socket 1 by press-fitting the movable terminal portion 52 into the second terminal hole 19 of the socket 1, engaging the second locking projection 55 with the second locking groove 17 of the second bracket 13, and engaging the second locking recess 56 with the second locking bead 18 of the second bracket 13.In such a state, the movable contact 58 is opposite the fixed contact 47 so that they can come into contact.

[0032] The first arm 67 and the second arm 68 are coupled to each other by inserting the second axle shaft portion 72 of the first arm 67 into the bearing hole 74 of the second arm 68, and the second axle shaft portion 72 of the second arm 68 into the bearing hole 74 of the first arm 67. Then, the first arm 67 and the second arm 68 are inserted into the recess 30 via the groove 24a of the base 1 in a folded state and spread out in a V shape. Furthermore, the guided projection 64 of the slider 6 is guided by the guide groove 36 of the button 3. In such a state, the first arm 67 and the first axle shaft portions 71 of the second arm 68 are inserted into the bearing holes 38 of the button 3. The button 3 is thus pretensioned in the projecting direction by a pretensioning force of the helical spring 4 arranged between the button 3 and the light guide 2.The movement of the probe 3 in the projecting direction is limited by the first arm 67 and the first axle shaft sections 71 of the second arm 68 abutting the inner edge of the bearing openings 38.

[0033] A key switch device assembled in this manner can be mounted on a circuit board (not shown) on which the LED 25b is mounted. When mounting the key switch device, the LED 25b is accommodated in the recess 30 of the light guide 2 located on a lower surface of the base 1. By providing such a structure, the height of the light guide 2 can be reduced. Accordingly, the light guide 2 can be designed so that it does not protrude upward from the base 1. That is, the position of the upper end of the light guide 2, that is, the position of the surface of the convex lens a, can be located below the upper end position of the rectangular frame portion 9. As a result, the height of the base 1 can be reduced.

[0034] It should be noted that a keycap (not shown) is mounted on button 3 so that it becomes a key on a keyboard.

[0035] In a push-button switch device assembled in this way, the fixed contact piece 41 and the movable contact piece 42 are arranged in the vicinity of the light guide 2 arranged in the opening 10 of the base 1, as shown in Fig. 2. The slider 6 is arranged along the third flat surface portion 46 of the movable contact piece 42. This means that the minimum necessary components (i.e., the light guide 2, the coil spring 4, the fixed contact piece 41, the movable contact piece 42, and the slider 6) are arranged closely together in an area surrounded by the rectangular frame portion 9. This accordingly enables a reduction in the space occupied in plan view (i.e., the size of the bottom portion 8) of the key switch device.

[0036] Furthermore, the base 1 is attached to the light guide 2 by placing the cylindrical body 28 of the light guide 2 in the opening 10 of the base 1 and locking the locking claws 29a of the claw portions 29 with the locking receiving portion 11 of the opening 10. At this time, the LED 25b is housed in the recess 30 formed by the cylindrical body 28. As shown in Fig. As shown in Figure 10, the upper end of the light guide 2 does not protrude beyond the upper end of the base 1. The other end of the coil spring 4, one end of which is in pressure contact with the inner surface of the button 3, is in direct pressure contact with the flange portion 22 of the light guide 2. As a result, the height of the key switch device can be reduced. That is, a reduction in the height of the key switch device (i.e., a reduction in the size of the key switch device in the movement direction of the button 3) is realized.

[0037] Next, the operation of a key switch device having the above structure will be described.

[0038] In the initial state in which a key cap (not shown) is not pressed, the button 3 is biased upward (that is, in an expansion / contraction direction of the coil spring 4 and away from the base 1) by a biasing force of the coil spring 4, and the first axle shaft portions 71 of the first arm 67 and the second arm 68 abut against an inner edge of the bearing holes 38 of the second arm 68 and the first arm 67. As a result, the button 3 is positioned at the projecting position. As shown in Fig. 11, the projecting piece 57 of the movable contact piece 42 is pressed by the pressing portion 59 of the slider 6, and the movable contact 58 is separated from the fixed contact 47 of the fixed contact piece 41.

[0039] When the button 3 is pressed down via the keycap against the biasing force of the coil spring 4, the slider 6 is also moved downward (that is, in an expansion / contraction direction of the coil spring 4 and toward the base 11). At this time, the protruding piece 57 of the movable contact piece 42 changes the pressing contact position from the concave surface 61 of the slider 6 to the first inclined surface 60. As a result, elastic energy stored in the third flat surface portion 46 of the movable contact piece 42 is converted into a force that biases the slider 6 downward. As a result, the slider 6 moves downward with respect to the button 3 alone, and the flat surface 66b of the lower end of the raised projection 66 collides with the flat surface 37b of the raised projection 37 of the button 3, generating a sound.Since the slider 6 does not simply fall under its own weight, but also an elastic force is applied from the movable contact piece 42, the sound volume to be generated can be increased. In the case of a keyboard equipped with a key switch device of the above structure, a user can clearly recognize that a push operation has been performed properly. If the keyboard is used in a game or the like, sufficient sound suitable for the usage situation can be generated by the push operation. The movable contact 58 is brought into contact with the fixed contact 47 by restoring the shape of the movable contact piece 42, which has been elastically deformed, so that it extends straight.

[0040] When the pressing operation of the button 3 is terminated, the biasing force of the coil spring 4 moves the button 3 upward. The first axle shaft portions 71 of the first arm 67 and the second arm 68 abut against the inner edge of the bearing holes 38, and the button 3 returns to the original position. The flat surface 37b of the lifting projection 37 formed on the button 3 abuts against the flat surface 66b of the lifted projection 66, so that the slider 6 is lifted. And the pressing portion 59 presses the projecting piece 57 of the movable contact piece 42 to elastically deform the third flat surface portion 54 (and further, the first flat surface portion 51). As a result, the movable contact 58 is separated from the fixed contact 47 and returns to the original state.

[0041] It should be noted that the present disclosure is not limited to the structure described in the embodiment, and various modifications are possible.

[0042] Although the light guide 2 includes the receiving portion main body 27 and the locking claws 29a, and in the above embodiment, a locking structure is employed to be locked with the locking receiving portion 11 formed in the opening 10 of the base 1, such structures are not mandatory. A circuit board (not shown) on which the LED 25b is mounted is arranged below the light guide 2. Since the light guide 2 is held between the circuit board and the spring, the locking structure is not mandatory.

[0043] Although the coil spring 4 is disclosed as an example of the elastic body in the above embodiment, the present invention is not limited to this. Other elastic components, such as foam or rubber, may also be used.

[0044] While various embodiments of the present disclosure have been described in detail with reference to the drawings, various aspects of the present disclosure will now be conclusively described. It should be noted that in the following description, a reference numeral is also used by way of example.

[0045] A key switch device according to the first aspect of the present disclosure comprises: a base 1 having an opening 10 in a central base part; a light guide 2 having an elastic body receiving portion 26, the light guide 2 being supported by the base 2 so as to be arranged in the opening 10; an attached button 3 capable of approaching and separating from the base 1 to cover the light guide 2; an elastic body 4 disposed between the elastic body receiving portion 26 and a lower surface of the button 3, the elastic body 4 biasing the button 3 in a separating direction in which the button 3 is separated from the base 1; a fixed contact piece 41 having a fixed contact 47, the fixed contact piece 41 being attached to the base 1; and a movable contact piece 42 attached to the base 1, which has a movable contact 58 to be brought into contact with the fixed contact 47 when the button 3 is moved in an approach direction in which the button 3 approaches the base 1.

[0046] According to the key switch device of the first aspect, the light guide 2 is arranged in the opening 10 of the base 1, and the elastic body 4 is brought into direct pressure contact with the elastic body receiving portion 26 of the light guide 2, so that the elastic body 4 is arranged on the inside of the light guide 2 in plan view. This makes it possible to reduce the space required for the key switch device. Furthermore, since the light guide 2 is directly biased by the elastic body 4, a reduction in the height of the key switch device can be achieved.

[0047] In a key switch device according to the second aspect of the present disclosure, the upper end of the light guide 2 is arranged below the upper end of the base 1.

[0048] According to the key switch device of the second aspect, the light guide 2 may have a low structure that does not protrude from the upper surface of the base 1. Furthermore, the button 3 may have a simple structure that does not require consideration of interference from a light guide.

[0049] In a key switch device according to the third aspect of the present disclosure, the light guide 2 includes a light guide main body 25 having a truncated conical shape and the elastic body receiving portion 26 protruding in a radial direction from the light guide main body 25.

[0050] In a key switch device according to the fourth aspect of the present disclosure, a recess 30 in which the LED 25b is to be arranged is formed in a lower portion of the light guide 2.

[0051] According to the key switch device of the fourth aspect, the LED 25b is arranged in the light guide 2, and thereby a further reduction in height is realized.

[0052] In a key switch device according to the fifth aspect of the present disclosure, the key switch device further comprises a slider 6 provided near the movable contact piece 42 and having a pressing portion 59, the slider 6 being capable of moving in a downward direction in response to the pressing of the button 3 and being supported by the base 1 so as to be displaceable in an up / down direction, wherein the movable contact piece 42 comprises a pressing receiving portion 57 to be pressed by the pressing portion 59, and the slider 6 is designed to be biased in the downward direction by the push-receiving portion 57 after the slider 6 moves in the downward direction and the push-receiving portion 59 rides over the push-receiving portion 57, so that the slider 6 collides with the base 1 or a part of the button and generates a sound.

[0053] According to the key switch device of the fifth aspect, it is possible to cause the slider 6 to collide with the base 1 and generate a sound by pressing the key 3 regardless of the low height. LIST OF REFERENCE SYMBOLS 1 base 2 light guides 3 buttons 4 Coil spring (example of elastic body) 5 Contact opening and closing mechanism 6 sliders 7 Lifting mechanism 8 floor section 9 rectangular frame section 10 Opening 11 Locking section 12 first bracket 13 second bracket 14 first locking groove 15 first connection hole 16 first locking bulge 17 second locking groove 18 second locking bead 19 second connection hole 20a, 20b Deepening 21a, 21b side wall 22 Flange section 23 Deformation prevention wall 24 Recessed part 25 fiber optic main body 25b LED 26 Elastic body receiving section 27 Receiving section main body 28 cylindrical body 29 Claw section 30 recess 31 flat plate section 32 side wall section 33a, 33b extension section 34 Lead Section 35 Guide wall 36 guide groove 37 inclined surface 38 Warehouse opening 39 lead 40 support section 41 fixed contact piece 42 movable contact piece 43 first planar section 44 fixed connection section 45 second planar section 46 third planar section 47 fixed contact 48 fourth plan-area section 49 first rest projection 50 first notch 51 first planar section 52 movable connecting section 53 second planar section 54 third planar section 55 second locking projection 56 second locking recess 57 protruding piece 58 movable contact 59 Press section 60 first inclined surface 61 concave surface 62 second inclined surface 64 led lead 65 flat section 66 raised projection 67 first arm 68 second arm 69 axle shaft 70 arm section 71 first axle shaft section 72 second axle shaft section 73 first lead 74 Bearing bore 75 second lead

Claims

[1] Push button switch device comprising: a base (1) having an opening (10) in a central base part; a light guide (2) having an elastic body receiving portion (26), wherein the light guide (2) is supported by the base (1) so as to be arranged in the opening (10); an attached button (3) capable of approaching and separating from the base (1) to cover the light guide (2); an elastic body (4) arranged between the elastic body receiving portion (26) and a lower surface of the button (3), the elastic body (4) biasing the button (3) in a separating direction in which the button (3) is separated from the base (1); a fixed contact piece (41) having a fixed contact (47), the fixed contact piece (41) being attached to the base (1); and a movable contact piece (42) attached to the base (1) and having a movable contact (58) to be brought into contact with the fixed contact (47) when the button (3) is moved towards the base (1) in an approach direction in which the button (3) approaches the base (1). [2] A key switch device according to claim 1, wherein an upper end of the light guide (2) is arranged below an upper end of the base (1). [3] The key switch device according to claim 2, wherein the light guide (2) comprises a light guide main body (25) having a truncated conical shape and the elastic body receiving portion (26) projecting in a radial direction from the light guide main body (25). [4] A key switch device according to any one of claims 1 to 3, wherein a recess (30) in which an LED (25b) is to be arranged is formed in a lower portion of the light guide (2). [5] A key switch device according to any one of claims 1 to 4, further comprising: a slider (6) provided near the movable contact piece (42) and having a pressing portion (59), the slider (6) being capable of moving in a downward direction in response to the pressing of the button (3) and being supported by the base (1) so as to be displaceable in an up / down direction, wherein the movable contact piece (42) comprises a pressing receiving portion (57) to be pressed by the pressing portion (59), and the slider (6) is designed to be biased in the downward direction by the push-receiving portion (57) after the slider (6) moves in the downward direction and the push-receiving portion (59) rides over the push-receiving portion (57), so that the slider (6) collides with the base (1) or a part of the button (3) and generates a sound.

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