Key switch device, keyboard and operating device

Abstract

The present invention provides a key switch device, keyboard, and operating device that offer a linear tactile sensation to the user and allow the user to recognize the ON state of an electrical contact solely by touch. [Solution] The key switch device 100 includes a slider 2 that can slide when the key top 1 is pressed, a housing 5 that guides the slider 2, a conical spring 3 provided between the slider 2 and the housing 5 that generates a repulsive force against the force pressing the key top 1, a spring 4 attached to the slider 2 that opens and closes an electrical contact 7a, and an electrical contact 7a that is positioned to have an air gap 41 between itself and the spring 4 in the state before the key top 1 is pressed, and is opened and closed by the spring 4 in accordance with the sliding of the slider 2, wherein the spring constant of the spring 4 is greater than the spring constant of the conical spring 3.

Description

Technical Field

[0001] The present invention relates to a key switch device, a keyboard, and an operating device.

Background Art

[0002] Key switch devices can be classified into a key switch device that provides a click feeling to the user and a key switch device that provides a linear feeling without a click feeling to the user. A key switch device that provides a click feeling to the user is described in, for example, Patent Document 1. A key switch device that provides a linear feeling to the user is described in, for example, Patent Document 2.

[0003] The click feeling is a feeling that the key top is drawn in when the operating force required to push the key top suddenly decreases due to buckling deformation of rubber or the like. On the other hand, the linear feeling is a feeling corresponding to the repulsive force of a spring proportional to the operating force.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] A key switch device with a linear feeling cannot provide a click feeling to the user. Therefore, the user can recognize that the electrical contact of the key switch device is turned on by looking at the input content on the operation screen. However, the user cannot recognize that the electrical contact of the key switch device is turned on only by the feeling without looking at the input content on the operation screen.

[0006] The present invention aims to provide a key switch device, keyboard, and operating device that provide a linear feel to the user and allow the user to recognize the ON state of an electrical contact solely by touch. [Means for solving the problem]

[0007] A key switch device according to one aspect of the present disclosure comprises: a sliding member that can slide when pressed by an operating member; a support member having a guide portion for guiding the sliding member; a first elastic member provided between the sliding member and the support member and generating a repulsive force against the force applied to the operating member; a second elastic member mounted on the sliding member and opening and closing an electrical contact in accordance with the sliding of the sliding member; and an electrical contact arranged to have a gap between itself and the second elastic member in the state before the operating member is pressed, and which is opened and closed by the second elastic member in accordance with the sliding of the sliding member, wherein the spring constant of the second elastic member is greater than the spring constant of the first elastic member. [Effects of the Invention]

[0008] According to one aspect of this disclosure, a linear tactile sensation is provided to the user, allowing the user to recognize the ON state of an electrical contact solely by touch. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1(A) is a perspective view of the keyboard according to this embodiment. Figure 1(B) is a perspective view of the operating device having the keyboard according to this embodiment. [Figure 2] Figure 2(A) is an exploded perspective view showing the individual components of the key switch device, and Figure 2(B) is a side view of the key switch device. [Figure 3] Figure 3(A) is a plan view showing the front side of the keycap, Figure 3(B) is a cross-sectional view of line AA in Figure 3(A), Figure 3(C) is a cross-sectional view of line BB in Figure 3(A), and Figure 3(D) is a plan view showing the back side of the keycap. [Figure 4]Figure 4(A) is a plan view of the slider seen from above, Figure 4(B) is a cross-sectional view of line AA in Figure 4(A), Figure 4(C) is a cross-sectional view of line BB in Figure 4(A), and Figure 4(D) is a perspective view of the slider. [Figure 5] Figure 5(A) is a plan view of the housing seen from above, Figure 5(B) is a cross-sectional view of line AA in Figure 5(A), Figure 5(C) is a cross-sectional view of line BB in Figure 5(A), and Figure 5(D) is a perspective view of the housing. [Figure 6] Figure 6(A) is a plan view of the key switch device seen from above, Figure 6(B) is a cross-sectional view of line AA in Figure 6(A), Figure 6(C) is a cross-sectional view of line BB in Figure 6(A), and Figure 6(D) is an enlarged view of the lower part of the key switch device. [Figure 7] Figure 7(A) shows the compression characteristics of a conical spring, Figure 7(B) shows the compression characteristics of a spring, and Figure 7(C) shows the compression characteristics of a key switch device that combines the compression characteristics of a conical spring and a spring. [Figure 8] Figure 8(A) is a cross-sectional view of a key switch device having a printed circuit board, and Figure 8(B) is a plan view showing the positional relationship between the spring and the first and second contacts. [Figure 9] Figure 9(A) is a block diagram showing the connection relationship between the printed circuit board and the computer, and Figure 9(B) is a circuit diagram of the keyboard controller and switch matrix included in the printed circuit board. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described below with reference to the drawings.

[0011] Figure 1(A) is a perspective view of the keyboard according to this embodiment. Figure 1(B) is a perspective view of the operating device having the keyboard according to this embodiment.

[0012] As shown in Figure 1(A), the keyboard 200 comprises an upper cover 9, a lower cover 10, and a key switch device 100. The key switch device 100 includes a key top 1 (operating member), a slider 2 (sliding member), a conical spring 3 (first elastic member), a spring 4 (second elastic member), a housing 5 (support member), a switch panel 6, a membrane sheet 7, and a substrate 8. The slider 2, conical spring 3, spring 4, and housing 5 constitute a switch unit 101. In the keyboard 200, the switch panel 6, membrane sheet 7, and substrate 8 of the key switch device 100 are formed to extend horizontally across the entire keyboard and are common to multiple switch units 101.

[0013] As shown in Figure 1(B), the operating device 220, such as a machine tool, medical equipment, ticket vending machine, ATM, or kiosk terminal, may be equipped with the keyboard 200 according to this embodiment as an input device.

[0014] Figure 2(A) is an exploded perspective view showing the components of the key switch device 100, and Figure 2(B) is a side view of the key switch device 100.

[0015] The key switch device 100 shown in Figure 2(A) includes a slider 2 to which a keytop 1 can be attached and which is slidable when the keytop 1 is pressed, a conical spring 3 provided between the slider 2 and the housing 5 that generates a repulsive force against the force of pressing the keytop 1, a spring 4 attached to the slider 2 that presses an electrical contact 7a, and a housing 5 to which the slider 2 is attached and which guides the vertical sliding of the slider 2. Furthermore, the key switch device 100 includes a switch panel 6 which is a positioning member that determines the position of the housing 5, a membrane sheet 7 disposed below the housing 5 and the switch panel 6, which includes an electrical contact 7a and has an air gap 41 (see Figure 6(D)) between it and the spring 4 and is pressed by the spring 4 in accordance with the sliding of the slider 2, and a substrate 8 disposed below the membrane sheet 7.

[0016] In the switch unit 101, a spring 4 is fixed inside the support portion 22 of the slider 2, a conical spring 3 is sandwiched between the slider 2 and the housing 5, and the slider 2 is engaged with the housing 5 so that the slider 2 can slide vertically. Thereby, the slider 2, the conical spring 3, the spring 4, and the housing 5 included in the switch unit 101 are integrated. The conical spring 3 is deformed according to the vertical sliding of the slider 2.

[0017] The conical spring 3 is a spring formed by winding a wire in a spiral shape with a gap, and the diameter of the conical spring 3 in plan view narrows from the lower part to the upper part of the conical spring 3. The spring 4 is a cylindrical spring, and the diameter of the spring 4 in plan view is constant. The materials of the conical spring 3 and the spring 4 are electrically conductive piano wire, hard steel wire, stainless steel, etc. In the present embodiment, the spring constant of the spring 4 is larger than the spring constant of the conical spring 3.

[0018] FIG. 3(A) is a plan view showing the front side of the key top 1, FIG. 3(B) is a cross-sectional view taken along the line A-A of FIG. 3(A), FIG. 3(C) is a cross-sectional view taken along the line B-B of FIG. 3(A), and FIG. 3(D) is a plan view showing the back side of the key top 1.

[0019] The key top 1 is formed by integral molding using resin as a constituent material. As shown in FIGS. 3(B) to 3(D), a protrusion 12 protruding downward from the upper surface 13 of the key top 1 is provided on the back surface of the key top 1. The protrusion 12 has a depression 11 for attaching to the cross-shaped protrusion 26 (see FIGS. 4(A) to 4(D)) of the slider 2.

[0020] FIG. 4(A) is a plan view of the slider 2 viewed from above, FIG. 4(B) is a cross-sectional view taken along the line A-A of FIG. 4(A), FIG. 4(C) is a cross-sectional view taken along the line B-B of FIG. 4(A), and FIG. 4(D) is a perspective view of the slider 2.

[0021] The slider 2 has a main body portion 21 and a support portion 22 extending from the main body portion 21 toward the housing 5. The support portion 22 is formed to have a substantially square cross-sectional shape. The support portion 22 has a locking claw 25 for slidably locking the slider 2 into the housing 5. The locking claw 25 engages with a step 52a on the inner wall of the guide 52 of the housing 5 (see Figures 5(B) and 5(C)). The outer circumference of the main body portion 21 is provided with a projection 24 for engaging with the key top 1 and an outer circumferential surface 23 that contacts the upper part of the conical spring 3. In addition, a space 121 for the guide 52 of the housing 5 to enter is provided between the main body portion 21 and the support portion 22. When the guide 52 of the housing 5 enters the space 121, the back surface 29 of the main body portion 21 faces the upper end of the guide 52 of the housing 5 (see Figures 6(B) and 5(C)).

[0022] The ceiling portion 28, which is the upper end of the slider 2, is provided with a recess 27 for accommodating the projection 12 having a cross-shaped recess 11 on the keytop 1, and a cross-shaped projection 26 for fitting into the cross-shaped recess 11 on the keytop 1. The depth of the recess 27 is the same as or greater than the height of the projection 12 on the keytop 1. This prevents the overall height of the key switch device 100 from increasing even if a cross-shaped projection 26 is provided on the upper end of the slider 2.

[0023] The support column 22 has an opening 122 at its bottom, and a projection 123 for fixing the spring 4 is provided inside the support column 22. A part of the spring 4 is inserted and fixed between the inner surface 124 of the support column 22 and the projection 123.

[0024] The slider 2 and housing 5 are made of different materials that have low friction when in contact. For example, the slider 2 is made of POM resin (polyacetal resin), and the housing 5 is made of ABS resin (a thermoplastic resin made by polymerizing three monomers: acrylonitrile, butadiene, and styrene). This is because if the slider 2 and housing 5 were made of the same material, the slider 2 would get stuck in the guide 52 during sliding, causing the keytop 1 to become stuck. For this reason, the slider 2 and housing 5 are made of different materials that have low friction when in contact. Note that the materials of the slider 2 and housing 5 are not limited to resin. The contact parts of the slider 2 and housing 5 may be processed to reduce the coefficient of friction so that friction is reduced when in contact.

[0025] Figure 5(A) is a plan view of housing 5 seen from above, Figure 5(B) is a cross-sectional view of line AA in Figure 5(A), Figure 5(C) is a cross-sectional view of line BB in Figure 5(A), and Figure 5(D) is a perspective view of housing 5.

[0026] The housing 5 is a member that supports the slider 2 and the conical spring 3, and includes a square plate portion 51 that constitutes a base substrate. The housing 5 also includes a guide 52 (guide portion) that stands upright from the center of the surface 51a of the plate portion 51 and guides the slider 2, a projection 53 that is erected on the surface 51a of the plate portion 51 and is located outside the guide 52 when the plate portion 51 is viewed from above, and guides the conical spring 3, and a leg portion 56 that is erected on the back surface 51b of the plate portion 51 and can be attached to the opening 61 of the switch panel 6 (see Figures 6(B) and 6(C)). The leg portion 56 also includes a claw portion 57 that sandwiches the switch panel 6 between itself and the back surface 51b of the plate portion 51. In some cases, the leg portion 56 alone is sufficient to fix it to the switch panel 6, so the leg portion 56 does not necessarily have to have the claw portion 57. An opening 151 is provided at the position of the plate portion 51 above the claw portion 57. This allows the user to check from above whether the switch panel 6 is sandwiched between the claw portion 57 and the back surface 51b of the plate portion 51. Note that the number of claw portions 57 is not limited to two, but may be four or more.

[0027] A roughly rectangular through-hole 150 is provided in the center of the guide 52 for inserting the support column 22 of the slider 2.

[0028] Figure 6(A) is a plan view of the key switch device as seen from above, Figure 6(B) is a cross-sectional view along line AA in Figure 6(A), and Figure 6(C) is a cross-sectional view along line BB in Figure 6(A). Figure 6(D) is an enlarged view of the lower part of the key switch device.

[0029] The key switch device 100 includes a switch unit 101 which includes a slider 2, a conical spring 3, a spring 4 and a housing 5; a key top 1 which is mounted on the switch unit 101 and pressed downwards; a switch panel 6 which is a positioning member that determines the position of the housing 5; a membrane sheet 7 which is placed below the housing 5 and the switch panel 6; and a substrate 8 which is placed below the membrane sheet 7.

[0030] The membrane sheet 7 is equipped with electrical contacts 7a. The electrical contacts 7a are located below the housing 5 and the switch panel 6, and when a predetermined pressing force is applied from the spring 4 by pressing the keytop 1, the two electrical contacts 7a physically come into contact and the contacts close. As shown in Figure 6(D), in the state before pressing the keytop 1, i.e., the steady state, a gap 41 is provided between the spring 4 and the membrane sheet 7. The distance of the gap 41 is indicated by d.

[0031] The switch panel 6 is placed on the membrane sheet 7 and the substrate 8, and is fixed to the substrate 8 by screws (not shown) via a spacer 62 provided below the switch panel 6. The shape of the opening 61 of the switch panel 6 is square in plan view, and when the legs 56 of the housing 5 are attached to the opening 61, the opening 61 is covered by the plate portion 51 of the housing 5. A space 90 of a predetermined height is formed between the switch panel 6 and the membrane sheet 7 by the spacer 62.

[0032] In a plan view, the area of ​​the plate portion 51 is larger than the area of ​​the opening 61 of the switch panel 6. Therefore, the plate portion 51 of the housing 5 contacts the periphery of the opening 61 of the switch panel 6, and the legs 56 of the housing 5 can be attached to the opening 61 of the switch panel 6. This prevents the entire housing 5 from sinking into the opening 61 of the switch panel 6.

[0033] If the height of the legs 56 is such that a space 90 of a predetermined height is formed, the key switch device 100 can be constructed without providing a switch panel 6 by attaching the lower part of the housing 5 to the upper surface of the membrane sheet 7 with double-sided tape or the like.

[0034] When the user presses keytop 1, the support column 22 of slider 2 slides against the through hole 150 of guide 52, causing slider 2 to move downward. The movement of slider 2 compresses the conical spring 3. As slider 2 moves, the spring 4 attached to slider 2 comes into contact with the membrane sheet 7, and the compression of spring 4 presses against the membrane sheet 7, turning on the electrical contact 7a.

[0035] When the user releases their finger from keycap 1, the slider 2 returns to its original position due to the elastic force of conical springs 3 and 4. In the membrane sheet 7, the pressing force of keycap 1 decreases, and the electrical contact 7a is turned off.

[0036] Figure 7(A) shows the pressing characteristics of the conical spring 3, Figure 7(B) shows the pressing characteristics of the spring 4, and Figure 7(C) shows the pressing characteristics of the key switch device 100, which is a combination of the pressing characteristics of the conical spring 3 and the spring 4. In other words, the pressing characteristics of the key switch device 100 in Figure 7(C) are a combination of the pressing characteristics in Figures 7(A) and 7(B). The horizontal axis shows the stroke (pressure amount) of the key top 1, and the vertical axis shows the load (pressure force or rebound force).

[0037] In Figures 7(A) to (C), x represents the stroke distance and F represents the load. d represents the distance of the gap 41 between spring 4 and membrane sheet 7 in the steady state (first distance). k1 represents the spring constant of conical spring 3, and k2 represents the spring constant of spring 4. Xsmall represents the small displacement of the stroke (second distance). Xsmall is slightly larger than the distance between the electrical contacts 7a in the membrane sheet 7. Pon represents the load at which spring 4 alone turns on the electrical contacts 7a. P'on (solid line) represents the load at which the electrical contacts 7a are turned on when the pressing characteristics of conical spring 3 and spring 4 are combined. P (dotted line) represents the load required to press keytop 1 by a distance d + Xsmall. α represents the initial pressure. Initial pressure is the force at which conical spring 3 pushes up slider 2 so that the steady state can be maintained even when keytop 1 is not pressed. The free length of the conical spring 3 is longer than the length of the conical spring 3 in Figures 6(B) and 6(C). During the assembly of the switch unit 101, the conical spring 3 compresses, and the force corresponding to the amount of compression corresponds to the initial pressure.

[0038] As shown in Figure 7(A), the compression characteristics of the conical spring 3 are linear with a relatively gentle slope. As the stroke x increases, the load F increases gradually in proportion to the stroke x.

[0039] As shown in Figure 7(B), the compression characteristics of spring 4 are linear with a steeper incline than those of conical spring 3. As the stroke x increases, the load F increases rapidly in proportion to the stroke x. At this time, the product of k2 and Xsmall is greater than the load Pon. That is, k2·Xsmall > Pon.

[0040] As shown in Figure 7(C), when the stroke is less than or equal to distance d, the force (pressing force or rebound force) F required to press keytop 1 satisfies Equation 1. When the stroke exceeds distance d, the force (pressing force or rebound force) F required to press keytop 1 satisfies Equation 2. For x ≤ d, F = k1x + α (Equation 1) If x > d, then F = k1x + k2(xd) + α (Equation 2) Furthermore, the load P when keytop 1 is pressed by the sum of the distance d and the small displacement Xsmall satisfies equation 3. P=k1·(d+Xsmall)+k2·Xsmall+α>P'on (Equation 3) In other words, the load P when keytop 1 or spring 4 is pressed down by the sum of distance d and small displacement Xsmall is greater than the load P'on that turns on the electrical contact 7a when the pressing characteristics of conical spring 3 and spring 4 are combined.

[0041] When the stroke is less than or equal to distance d, the force F required to press down on keytop 1 is only affected by the pressing characteristics of the conical spring 3, resulting in a light pressing feel where the rebound force increases gradually in proportion to the stroke. When the stroke exceeds the sum of distance d and the minute displacement Xsmall, the spring 4 contacts the membrane sheet 7, and the electrical contact 7a of the membrane sheet 7 turns on.

[0042] Spring 4 applies a force to the membrane sheet 7 that is independent of the operating force. By setting the spring constant of spring 4 and the load P'on so that the load P when spring 4 is pressed by the sum of the distance d and the minute displacement Xsmall exceeds the load P'on, the electrical contact 7a can be turned on almost simultaneously with the timing when spring 4 contacts the membrane sheet 7. After spring 4 contacts the membrane sheet 7, the initial pressure α and the repulsive force of cone spring 3, as well as the repulsive force of spring 4, are added to the tactile sensation. Therefore, the tactile sensation felt by the user is the combined repulsive force of the initial pressure α, cone spring 3, and spring 4. In other words, after spring 4 contacts the membrane sheet 7, the spring constant of spring 4 changes to one that is greater than the spring constant of cone spring 3 and cannot be pushed all the way to the end of the stroke unless the user consciously increases the load F. As a result, the user can unconsciously stop applying the operating force to press the keytop 1 and recognize the turning on of the electrical contact 7a by touch alone. In this way, the user can recognize the turning on of the electrical contact 7a by touch alone due to the change in the spring constant from the conical spring 3 to the spring constant of spring 4.

[0043] In conventional linear-feel key switch devices, users could not recognize that the electrical contacts of the key switch device were turned on by touch alone, without looking at the input content on the operation screen. However, in the key switch device 100 of this embodiment, users can recognize that the electrical contacts 7a are turned on by touch alone.

[0044] Therefore, the user does not need to press keytop 1 all the way to the end of the stroke, eliminating the need to apply unnecessary force to keytop 1. This reduces the accumulation of fatigue from typing.

[0045] Furthermore, in the state before the keytop 1 is pressed, i.e., the steady state, the distance D1 (see Figures 6(B) and (C)) between the back surface 29 of the main body 21 and the upper end of the guide 52 of the housing 5 is greater than the sum of the distance d and the minute displacement Xsmall. As a result, even if the keytop 1 or spring 4 is pressed by the sum of the distance d and the minute displacement Xsmall, the slider 2 is prevented from hitting the guide 52 of the housing 5. This also reduces the recoil on the fingers caused by the slider 2 hitting the guide 52, thereby reducing fatigue. In addition, the noise generated by the contact between the slider 2 and the guide 52 is also reduced, thus reducing typing noise.

[0046] In this embodiment, a characteristic feature is the abrupt change from the spring constant of the conical spring 3 to the spring constant of the spring 4. Therefore, when the stroke is less than or equal to distance d, it is necessary to have a very light pressing feel. The spring constant of the conical spring 3 changes depending on the wire diameter, number of turns, and inner diameter. In particular, when the wire diameter and the amount of expansion and contraction do not change, the spring constant can be reduced by increasing the number of turns of the conical spring 3.

[0047] In this embodiment, a conical spring 3 is inserted between the slider 2 and the housing 5, instead of a cylindrical spring like spring 4. With a cylindrical spring like spring 4, increasing the number of turns causes the coils to come into contact with each other due to the amount of compression, which limits the overall stroke length. In contrast, the conical spring 3 avoids contact between its coils, thus avoiding limitations on the stroke. Furthermore, if there are limitations on the height of the spring, the number of turns of the conical spring 3 can be increased compared to a cylindrical spring like spring 4, and a higher number of turns reduces the load on each coil, thus extending the keystroke life. For these reasons, the conical spring 3 is used.

[0048] In this embodiment, the conical springs 3 and 4 can be customized by changing them to conical springs 3 and 4 with different lengths or spring constants. Furthermore, by changing the overall length of spring 4, the distance d of the gap 41 can be changed, making it possible to change the ON position of the electrical contact 7a. Since spring 4 applies a force to the membrane sheet 7 that is independent of the operating force, even if the ON position of the electrical contact 7a is changed, the ON state of the electrical contact 7a can be recognized by the change in the spring constant by setting the spring constant of spring 4 and the load P'on such that the load P when spring 4 is pressed by the sum of the distance d and the minute displacement Xsmall exceeds the load P'on. In addition, by changing spring 4 to a spring with a larger spring constant, the change in load while pressing the minute displacement Xsmall can be made larger.

[0049] In this embodiment, it is preferable to set the spring constant of spring 4 to 5 to 15 times the spring constant of conical spring 3 in order to allow the user to start pressing the keytop 1 with a lighter feel than conventional light-feeling key switch devices (e.g., load 0.2N), to ensure that the load at the end of the stroke exceeds that of conventional heavy-feeling key switch devices (e.g., load 0.8N), and to further allow the user to clearly recognize that the electrical contact 7a is ON. If the spring constant of spring 4 is less than 5 times the spring constant of conical spring 3, it is insufficient for the user to recognize that the electrical contact 7a is ON by feel alone, and there is a risk that the user will press down the keytop 1 more than necessary, causing the slider 2 to hit the guide 52. If the spring constant of spring 4 is 5 times or more the spring constant of conical spring 3, it will be greater than the end pressure of conventional light-feeling key switch devices, and it will also exceed the maximum load before clicking of key switch devices that provide a click feeling. If the spring constant of spring 4 exceeds 15 times the spring constant of conical spring 3, the operating force required to push spring 4 down by a small displacement Xsmall becomes excessive. This can result in a feeling that the slider 2 is hitting the guide 52 or that the distance to the stroke end has shortened, potentially failing to reduce fatigue.

[0050] Furthermore, as shown in Figure 7(A), since a gradual increase in load is required from the initial pressure to the final pressure for the conical spring 3 alone, it is preferable to keep the final pressure to 2 to 3 times the initial pressure α. The final pressure is the force with which the conical spring 3 pushes up the slider 2 when the electrical contact 7a is turned on.

[0051] Furthermore, in this embodiment, it is preferable that the load P when the spring 4 is pressed by the sum of the distance d and the minute displacement Xsmall is between 8 and 12 times the initial pressure α of the conical spring 3 alone. If the load P is less than 8 times the initial pressure α, it is insufficient for the user to recognize that the electrical contact 7a is on by touch alone, and if the load P exceeds 12 times the initial pressure α, the operating force required to press the spring 4 by the minute displacement Xsmall becomes excessive. Also, by having the load P between 8 and 12 times the initial pressure α, as the stroke end approaches, the operating force becomes such that the user cannot fully press the key top 1 without consciously thinking about it.

[0052] The minute displacement Xsmall is greater than 0mm and less than or equal to 1 / 5 of the distance d of the gap 41. If the minute displacement Xsmall exceeds 1 / 5 of the distance d of the gap 41, the difference between the operating force when the spring 4 contacts the membrane sheet 7 and the operating force when the electrical contact 7a turns on increases, and there is a risk that the user will stop pressing the keytop 1 before the electrical contact 7a turns on, resulting in input omission. More preferably, the minute displacement Xsmall is greater than 0mm and less than or equal to 1 / 10 of the distance d. Even more preferably, the minute displacement Xsmall is greater than 0mm and less than or equal to 1 / 20 of the distance d. Since the minute displacement Xsmall is considerably smaller than the distance d, the user can recognize the turning on of the electrical contact 7a by touch alone at almost the same time that the spring 4 contacts the membrane sheet 7.

[0053] In this embodiment, a conical spring 3 is used as the spring sandwiched between the slider 2 and the housing 5, in terms of shape and compression characteristics. However, the shape of the spring sandwiched between the slider 2 and the housing 5 is not limited as long as characteristics equivalent to those of the conical spring 3 can be obtained.

[0054] In this embodiment, two springs (i.e., conical spring 3 and spring 4) are used as tactile components to enable the user to recognize the ON state of the electrical contact 7a in linear touch. However, the number of tactile components is not limited, as it is also possible to enable the user to recognize the ON state of the electrical contact 7a by combining three or more components. For example, by replacing conical spring 3 with two conical springs of different diameters, the total number of tactile components becomes three. Similarly, by replacing spring 4 with two springs of different diameters, the total number of tactile components becomes three. Furthermore, a projection member for pressing the electrical contact 7a of the membrane sheet 7 may be provided below spring 4, so that the tactile components consist of three parts: conical spring 3, spring 4, and projection member.

[0055] In this embodiment, a membrane sheet 7 including an electrical contact 7a and a substrate 8 are used. Instead of the membrane sheet 7 and substrate 8, a printed circuit board 8a having a first contact 83 and a second contact 84 may be used. Figure 8(A) is a cross-sectional view of a key switch device 102 having a printed circuit board 8a. Figure 8(B) is a plan view showing the positional relationship between the spring 4 and the first contact 83 and the second contact 84. In this case, the first contact 83 and the second contact 84, which are provided adjacent to each other on the surface of the printed circuit board 8a, are positioned below the spring 4 with a gap 41 between them. As the slider 2 slides, the spring 4 contacts the first contact 83 and the second contact 84 provided on the printed circuit board 8a, electrically short-circuiting the first contact 83 and the second contact 84 via the spring 4. As a result, the spring 4, the first contact 83 and the second contact 84 constitute an electrical contact 71. This eliminates the need for the membrane sheet 7, thus reducing the number of parts.

[0056] When using the membrane sheet 7 and substrate 8, the electrical contact 7a does not turn on simply by the spring 4 contacting the membrane sheet 7; the load P when the spring 4 is pressed by the sum of the distance d and the small displacement Xsmall must exceed the load P'on. Therefore, strictly speaking, there is a slight lag between the spring 4 contacting the membrane sheet 7 and the electrical contact 7a turning on, but this lag can be ignored due to the magnitude of the stress on the spring 4.

[0057] On the other hand, when using the printed circuit board 8a, the spring 4 attached to the slider 2 contacts the first contact 83 and the second contact 84 provided on the printed circuit board 8a, allowing current to flow from the first contact 83 to the second contact 84 or from the second contact 84 to the first contact 83, thus enabling the electrical contact 71 to be turned on simultaneously with the contact. Furthermore, after the spring 4 makes contact with the first contact 83 and the second contact 84, the repulsive force increases due to the spring constant of the spring 4, allowing the user to recognize that the electrical contact 71 is turned on by touch alone.

[0058] Figure 9(A) is a block diagram showing the connection relationship between the printed circuit board 8a and the computer 210, and Figure 9(B) is a circuit diagram of the keyboard controller 180 and switch matrix 181 included in the printed circuit board 8a.

[0059] As shown in Figure 9(A), the printed circuit board 8a includes a keyboard controller 180 and a switch matrix 181, and is connected to an external device, a computer 210. The keyboard controller 180 is composed of an IC (integrated circuit) or a microcontroller, recognizes pressed keys, and transmits the corresponding key code to the computer 210. The keyboard controller 180 also returns information about the type of keyboard 200 to the computer 210 in response to a request from the computer 210. The switch matrix 181 includes a first contact 83, a second contact 84, and a diode 85 for each switch unit 101.

[0060] As shown in Figure 9(B), the keyboard controller 180 includes output ports 183a to 183d that output drive current to the switch matrix 181, and receiving ports 184a to 184d that receive current corresponding to the on or off state of the electrical contacts 71 from the switch matrix 181. The number of output ports and receiving ports is not limited to the example in Figure 9(B). For example, when the shown electrical contact 71 is on, the drive current from output port 183a flows through path 185 via diode 85 to receiving port 184a. Even if multiple electrical contacts are on simultaneously, the diode 85 prevents current leakage, thus avoiding ghost input.

[0061] Keyboard 200 supports N-key rollover (N=2 or greater integer), meaning that if multiple keys are pressed simultaneously, all key inputs are recognized in the order they were pressed.

[0062] As described above, according to this embodiment, the key switch device 100 includes a slider 2 that can slide when the key top 1 is pressed, a housing 5 that guides the slider 2, a conical spring 3 provided between the slider 2 and the housing 5 that generates a repulsive force against the force of pressing the key top 1, a spring 4 attached to the slider 2 that opens and closes an electrical contact 7a, and an electrical contact 7a or 71 that is arranged to have a gap 41 between itself and the spring 4 in the state before the key top 1 is pressed, and is opened and closed by the spring 4 in accordance with the sliding of the slider 2, wherein the spring constant of the spring 4 is greater than the spring constant of the conical spring 3. This provides the user with a linear key feel without a click sensation, and allows the user to recognize the ON state of the electrical contact 7a by touch alone. Furthermore, since the user recognizes the ON state of the electrical contact 7a by touch alone, it is possible to prevent input omissions by the user.

[0063] The spring provided between the slider 2 and the housing 5 is a conical spring 3. This allows for increased spring windings while avoiding contact between coils, thus avoiding limitations on stroke. Furthermore, a higher number of coil windings reduces the load on each individual coil, extending the lifespan of the conical spring.

[0064] The spring constant of spring 4 is between 5 and 15 times the spring constant of conical spring 3. As a result, the repulsive force increases immediately after spring 4 contacts the membrane sheet 7, allowing the user to recognize the ON state of electrical contact 7a or 71 by touch alone.

[0065] Furthermore, according to this embodiment, the key switch device 100 includes a slider 2 that can slide when the key top 1 is pressed, a housing 5 having a guide 52 that guides the slider 2, a conical spring 3 provided between the slider 2 and the housing 5 and generating a repulsive force against the force pressing the key top 1, a spring 4 mounted on the slider 2 that opens and closes an electrical contact 71 in accordance with the sliding of the slider 2, and a printed circuit board 8a having a first contact 83 and a second contact 84 that constitute the electrical contact 71, having an air gap 41 between it and the spring 4, and the spring 4 contacting the first contact 83 and the second contact 84 in accordance with the sliding of the slider 2, wherein the spring constant of the spring 4 is greater than the spring constant of the conical spring 3. This provides the user with a linear key feel without a click sensation, and allows the user to recognize the ON state of the electrical contact 71 by touch alone. In particular, after the spring 4 makes contact with the first contact 82 and the second contact 84, the repulsive force increases due to the spring constant of the spring 4, allowing the user to recognize the ON state of the electrical contact 71 by touch alone. Furthermore, since the user recognizes the ON state of the electrical contact 71 by touch alone, input errors by the user can be prevented. In addition, since a membrane sheet 7 is not required, the number of parts can be reduced.

[0066] Furthermore, the present invention is not limited to the embodiments described above, and can be implemented in various modified forms without departing from its essence. [Explanation of Symbols]

[0067] 1 Keycap, 2 Slider, 3 Conical spring, 4 Spring, 5 Housing, 6 Switch panel, 7 Membrane sheet, 7a, 71 Electrical contact, 8 Circuit board, 8a Printed circuit board, 83 First contact, 84 Second contact, 85 Diode, 100, 102 Key switch device, 101 Switch unit, 180 Keyboard controller, 181 Switch matrix, 183a~183d Output ports, 184a~184d Receive ports, 200 Keyboard

Claims

1. A sliding member that can slide when pressed by an operating member, A support member having a guide portion for guiding the sliding member, A first elastic member is provided between the sliding member and the support member, and generates a repulsive force against the force pressing down on the operating member. A second elastic member is attached to the sliding member and opens and closes an electrical contact in accordance with the sliding of the sliding member, An electrical contact is provided, which is positioned so as to have a gap between it and the second elastic member in the state before the operating member is pressed, and which is opened and closed by the second elastic member in accordance with the sliding of the sliding member, Equipped with, A key switch device characterized in that the spring constant of the second elastic member is greater than the spring constant of the first elastic member.

2. The key switch device according to claim 1, characterized in that the first elastic member is a conical spring.

3. The key switch device according to claim 1, characterized in that the spring constant of the second elastic member is five times or more the spring constant of the first elastic member.

4. The membrane sheet includes the aforementioned electrical contacts and is pressed by the second elastic member, The key switch device according to claim 1, characterized in that the electrical contact closes when the operating member is pressed by the sum of a first distance, which is the distance of the gap, and a second distance, which is smaller than the first distance.

5. The key switch device according to claim 4, characterized in that the second distance is greater than 0 mm and less than or equal to 1 / 5 of the first distance.

6. The sliding member has a main body and a support column extending from the main body toward the support member. The key switch device according to claim 4, characterized in that, in the state before the operating member is pressed, the distance between the back surface of the main body and the upper end of the guide is greater than the sum of the first distance and the second distance.

7. The printed circuit board comprises a first contact and a second contact that constitute the aforementioned electrical contact, arranged adjacent to each other. The key switch device according to claim 1, characterized in that the electrical contacts are closed by short-circuiting the first contact and the second contact with the second elastic member in response to the sliding of the sliding member.

8. A keyboard characterized by comprising a plurality of key switch devices according to any one of claims 1 to 7.

9. An operating device characterized by having the keyboard described in claim 8.

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