Keyboard and operating device

Abstract

To provide a keyboard and operating device that can offer a good feel to the user and accurately detect the simultaneous pressing of multiple keys. [Solution] Unlike typical membrane switches, the keyboard 200 has a printed circuit board 8 with a diode 85 as the lower film of the membrane switch, thus avoiding current leakage caused by simultaneous pressing of multiple keys and enabling accurate detection of simultaneous pressing of multiple keys. Furthermore, the spring 4 opens and closes the electrical contacts 71 (conductive member 74, first contact 83 and second contact 84) during the decrease in operating force F caused by the buckling deformation of the dome rubber 3, so there is no discrepancy between the operating sensation and the contact-on operation, providing the user with a good feel.

Description

Technical Field

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

Background Art

[0002] Conventionally, there is known a keyboard that includes a rubber that gives a user a click feeling of a key and a spring that opens and closes a contact, and the spring presses a membrane switch during the click of the key to turn on the contact in the membrane switch (see, for example, Patent Document 1). In this keyboard, the membrane switch can be turned on during the click of the key, there is no deviation between the operation feeling and the contact-on operation, and a good feeling can be provided to the user.

[0003] In recent years, the use of a keyboard in games has increased, the number of games operated by pressing a plurality of keys simultaneously has increased, and pressing a plurality of keys simultaneously is essential for playing games.

[0004] When three or more keys are pressed simultaneously, there is known a phenomenon called ghost input in which current flows into a circuit in a keyboard in an unintended direction (see, for example, Patent Documents 2 and 3).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0006] The keyboard described in Patent Document 1 uses membrane switches, and there is a risk of ghost input occurring when three or more keys are pressed simultaneously, causing current to flow in an unintended direction.

[0007] Therefore, it is conceivable to implement a diode in the membrane switch to avoid ghost input. However, since a membrane switch has a structure in which films with printed contacts face each other with a spacer in between, it is not easy to implement a diode to avoid ghost input in these films, and manufacturing costs will increase. In addition, since the diode has a height greater than the distance between the upper and lower films of the membrane switch, it is physically difficult to place the diode between the upper and lower films.

[0008] The present invention aims to provide a keyboard and operating device that can provide a good feel to the user and accurately detect the simultaneous pressing of multiple keys. [Means for solving the problem]

[0009] A keyboard according to one aspect of the present disclosure comprises: a sliding member that can slide by pressing an operating member; a first elastic member mounted on the sliding member and elastically buckling deformed in response to pressing the operating member; a second elastic member mounted on the sliding member and opening and closing electrical contacts in response to the sliding of the sliding member; a support member that guides the sliding member; a membrane sheet having a first surface pressed by the second elastic member and a second surface on the opposite side of the first surface and including a conductive member; a controller having an output port that outputs a drive current and a receiving port that receives the current of the electrical contacts; a printed circuit board having a first contact connected to the output port, a second contact connected to the receiving port, and a diode connected between the receiving port and the second contact, and facing the second surface of the membrane sheet; and a spacer that forms a space between the membrane sheet and the printed circuit board, wherein the conductive member contacts the first contact and the second contact in response to the sliding of the sliding member. [Effects of the Invention]

[0010] According to one aspect of this disclosure, it is possible to provide the user with a good feel and to accurately detect the simultaneous pressing of multiple keys. [Brief explanation of the drawing]

[0011] [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 switch unit, and Figure 2(B) is a perspective view of the integrated switch unit. [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 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 7] Figure 7 shows the press-down characteristics of the key switch device. [Figure 8] Figures 8(A) to 8(D) are cross-sectional views showing examples of the configuration of a membrane sheet, spacer, and printed circuit board. [Figure 9] Figure 9(A) is a perspective view of the membrane sheet, spacer, and printed circuit board. Figure 9(B) is a plan view showing the positional relationship between the electrical contacts and the LED. [Figure 10] Figure 10(A) is a block diagram showing the connection relationship between the printed circuit board and the computer, and Figure 10(B) is a circuit diagram of the keyboard controller and switch matrix included in the printed circuit board. [Modes for carrying out the invention]

[0012] Embodiments of the present invention will be described below with reference to the drawings.

[0013] 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.

[0014] As shown in FIG. 1(A), the keyboard 200 includes 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 dome rubber 3 (first elastic member), a spring 4 (second elastic member), a housing 5 (supporting member), a switch panel 6, a membrane sheet 7, and a printed circuit board 8. The slider 2, the dome rubber 3, the spring 4, and the housing 5 constitute a switch unit 101. In the keyboard 200, the switch panel 6, the membrane sheet 7, and the printed circuit board 8 in the key switch device 100 are formed to expand horizontally over the entire keyboard and are shared for a plurality of switch units 101.

[0015] As shown in FIG. 1(B), an operating device 220 such as a machine tool, a medical device, a ticket vending machine, an ATM, or a kiosk terminal may include the keyboard 200 according to the present embodiment as an input device.

[0016] FIG. 2(A) is an exploded perspective view showing the components of the switch unit 101, and FIG. 2(B) is a perspective view of the integrated switch unit 101.

[0017] The switch unit 101 in FIG. 2(A) includes a slider 2 to which the key top 1 can be attached, a dome rubber 3 that elastically buckles and deforms by pressing the key top 1 and applies a repulsive force corresponding to the elastic buckling deformation to the slider 2, a spring 4 that is attached to the slider 2 and presses an electrical contact such as a membrane switch or a mechanical switch (not shown), and a housing 5 to which the slider 2 is attached and guides the vertical sliding of the slider 2.

[0018] In the switch unit 101, the spring 4 is fixed inside the column portion 22 of the slider 2, the dome rubber 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. As a result, the slider 2, the dome rubber 3, the spring 4, and the housing 5 included in the switch unit 101 are integrated as shown in FIG. 2(B).

[0019] The dome rubber 3 is a dome-shaped member integrally molded from rubber material, and has a ring-shaped base 31, a dome portion 32 rising from the base 31 in a dome shape, and a cylindrical portion 33 extending upward from the top of the dome portion 32. The cylindrical portion 33 is press-fitted onto the outer circumferential surface 23 of the slider 2 from below and attached to the outer circumferential surface 23. The dome portion 32 of the dome rubber 30 deforms in accordance with the vertical sliding of the slider 2.

[0020] Figure 3(A) is a plan view showing the front side of keytop 1, 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 keytop 1.

[0021] The keytop 1 is formed by integral molding using resin as the constituent material. As shown in Figures 3(B) to (D), the back surface of the keytop 1 is provided with a projection 12 that protrudes downward from the upper surface 13 of the keytop 1. The projection 12 has a recess 11 for attaching to the cross-shaped projection 26 of the slider 2 (see Figures 2(A) and 4(A) to 4(D)).

[0022] Figure 4(A) is a plan view of slider 2 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 slider 2.

[0023] 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 (see Figures 5(B) and 5(C)) on the inner wall of the guide 52 of the housing 5. The outer circumference of the main body portion 21 is provided with an outer circumferential surface 23 into which a projection 24 for engaging with the key top 1 and a dome rubber 3 are press-fitted. 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] The housing 5 is a member that supports the slider 2 and the dome rubber 3, and includes a square plate portion 51 that constitutes the base substrate. The housing 5 also includes a guide 52 (first guide portion) that stands upright from the center of the surface 51a of the plate portion 51 and guides the dome rubber 3, a projection 53 (second guide portion) that is erected on the surface 51a of the plate portion 51 and is provided outside the guide 52 when the plate portion 51 is viewed from above and guides the dome rubber 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 (member to be mounted) (see Figure 6(B)(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 above the claw portion 57 at the position of the plate portion 51. 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.

[0029] 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.

[0030] Figure 6(A) is a plan view of the key switch device according to the second embodiment 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).

[0031] The key switch device 100 includes a switch unit 101 which includes a slider 2, a dome rubber 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 printed circuit board 8 which is placed below the membrane sheet 7. The printed circuit board 8 has a diode 85 which will be described later.

[0032] The membrane sheet 7 and the printed circuit board 8 are equipped with electrical contacts 71. The electrical contacts 71 are located below the housing 5 and the switch panel 6, and close when a predetermined pressing force is applied from the spring 4 by pressing the keytop 1.

[0033] The switch panel 6 is placed on the membrane sheet 7 and the printed circuit board 8, and is fixed to the printed circuit board 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.

[0034] 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.

[0035] 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 deforms the dome rubber 3 outward. 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 71.

[0036] When the user lifts their finger from keycap 1, the slider 2 returns to its original position due to the elastic force of the dome rubber 3 and spring 4. In the membrane sheet 7, the pressing force of keycap 1 decreases, and the electrical contact 71 is turned off.

[0037] Figure 7 shows the pressing characteristics of the key switch device 100. The horizontal axis represents the stroke S (pressing amount) of the key top 1, and the vertical axis represents the operating force (pressing force) F. Point a in Figure 7 indicates that the electrical contact 71 is ON.

[0038] As shown in Figure 7, as the operating force F of the keytop 1 increases, the stroke S also increases accordingly. At this time, the dome rubber 3 undergoes elastic deformation, and a reaction force from the dome rubber 3 acts on the keytop 1. The pressing characteristics in this case are equal to the load displacement characteristics of the dome rubber 3 itself. The operating force F increases until the load acting on the dome rubber 3 reaches the buckling load of the dome rubber 3. Once the buckling load is reached, the operating force F gradually decreases as the stroke S increases. By obtaining a peak operating force F0 through this elastic buckling deformation of the dome rubber 3, the user can obtain the characteristic click feeling of keystrokes.

[0039] In this embodiment, the stroke S1 when the contact is turned on is set to a value greater than the stroke S0 at which the peak operating force F0 is generated, and smaller than the end stroke S2 ​​(for example, midway between S0 and S2). In this way, in the key switch device 100, the spring 4 opens and closes the electrical contact 71 while the operating force F decreases due to the buckling deformation of the dome rubber 3, so there is no discrepancy between the operating sensation and the contact-on operation, and a good feel can be provided to the user.

[0040] In the switch unit 101, the area of ​​the plate portion 51 is larger than the area of ​​the opening 61 of the switch panel 6 when viewed from above. 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.

[0041] If the diameter of the base 31 of the dome rubber 3 is larger than the length of one side of the plate portion 51 of the housing 5, the base 31 of the dome rubber 3 will protrude from the plate portion 51 of the housing 5, making it difficult to obtain the pressing characteristics of the key switch device 100 shown in Figure 7. If the diameter of the base 31 of the dome rubber 3 is smaller than 70% of the length of one side of the plate portion 51 of the housing 5, the size of the dome rubber 3 will be smaller, making it difficult to obtain the pressing characteristics of the key switch device 100 shown in Figure 7. For this reason, it is preferable that the diameter of the base 31 of the dome rubber 3 is between 70% and 100% of the length of one side of the plate portion 51 of the housing 5. In particular, by setting the diameter of the base 31 of the dome rubber 3 and the length of one side of the plate portion 51 of the housing 5 to be the same length, the size of the dome rubber 3 will be larger, making it easier to obtain the pressing characteristics of the key switch device 100 shown in Figure 7, and allowing the housing 5 to hold the dome rubber 3.

[0042] Figures 8(A) to 8(D) are cross-sectional views showing examples of the configuration of the membrane sheet 7, spacer 76, and printed circuit board 8. Figure 8(A) shows the diode 85 provided on the lower surface 82 of the printed circuit board, Figure 8(B) shows the diode 85 provided on the upper surface 81 of the printed circuit board, Figure 8(C) shows the same configuration as Figure 8(A) with the LED 95 provided, and Figure 8(D) shows the same configuration as Figure 8(B) with the LED 95 provided. Figure 9(A) is a perspective view of the membrane sheet 7, spacer 76, and printed circuit board 8. Figure 9(B) is a plan view showing the positional relationship between the electrical contact 71 and the LED 95. Figures 8(A) to 8(D) show the configuration of the membrane sheet 7 and printed circuit board 8 corresponding to one switch unit 101. Therefore, in the keyboard 200 of Figure 1, the configurations of the membrane sheet 7 and printed circuit board 8 shown in Figures 8(A) to 8(D) are arranged for each key switch device 100 or switch unit 101.

[0043] A spacer 76 is provided to form a space 78 between the membrane sheet 7 and the printed circuit board 8. As shown in Figures 8(A) and (C), the membrane sheet 7 has an upper surface 72 (first surface) which is pressed down by the spring 4 in response to the sliding of the slider 2, and a lower surface 73 (second surface) which is on the opposite side of the upper surface 72 and includes an island-shaped conductive member 74. One island-shaped conductive member 74 is printed on the lower surface 73 for each switch unit 101, and when the membrane sheet 7 is pressed down by the spring 4, the conductive member 74 bridges the first contact 83 and the second contact 84 of the printed circuit board 8. Therefore, when the membrane sheet 7 is pressed down by the spring 4, current flows from the first contact 83 to the second contact 84 via the conductive member 74, or from the second contact 84 to the first contact 83 via the conductive member 74. The size of the conductive member 74 is such that it can bridge the first contact 83 and the second contact 84 of the printed circuit board 8, and the shape of the conductive member 74 is not particularly limited. The island-shaped conductive members 74 are not connected to any wiring patterns, and they are isolated from adjacent conductive members 74. Only the island-shaped conductive members 74 need to be formed on the lower surface 73 of the membrane sheet 7, and there is no need to provide wiring patterns on the membrane sheet 7, thus reducing manufacturing costs.

[0044] In Figures 8(A) and (C), the diode 85 is provided on the lower surface 82 of the printed circuit board 8, while in Figures 8(B) and (D), the diode 85 is provided on the upper surface 81 of the printed circuit board 8. The configurations in Figures 8(C) and (D) are identical to those in Figures 8(A) and (B), respectively, except that an LED (Light Emitting Diode) 95 (lighting device) is provided.

[0045] As shown in Figures 8(A) and (C), the printed circuit board 8 has an upper surface 81 (third surface) facing the lower surface 73 of the membrane sheet 7, and a lower surface 82 (fourth surface) on the opposite side of the upper surface 81. The upper surface 81 has a first contact 83 connected to the output ports 183a to 183d of the keyboard controller 180 (see Figure 10(B)) and a second contact 84 connected to the receiving ports 184a to 184d of the keyboard controller 180 (see Figure 10(B)). The lower surface 82 is provided with a diode 85 connected between the receiving ports 184a to 184d of the keyboard controller 180 (see Figure 10(B)) and the second contact 84. The second contact 84 and the diode 85 are connected by a via wiring 86 that penetrates the printed circuit board 8. The first contact 83 and the second contact 84 face each other across a space 78, and when the membrane sheet 7 is pressed down by the spring 4, the conductive member 74 contacts the first contact 83 and the second contact 84. The conductive member 74, the first contact 83 and the second contact 84 are formed from a conductive ink paste such as carbon or silver, and constitute the electrical contact 71 described above. The first contact 83 and the second contact 84 may also be formed from copper foil or metal plating.

[0046] For example, the thickness of the membrane sheet 7 is 70 μm to 100 μm, and the height of the spacer 76, that is, the distance between the membrane sheet 7 and the printed circuit board 8, is 100 to 150 μm. For example, the thickness of the diode 85 is 0.3 to 0.8 mm (300 to 800 μm). For example, the thickness of the conductive member 74, the first contact 83, and the second contact 84 are each 5 to 10 μm. For example, the thickness of the printed circuit board 8 is 1 to 2 mm, and the thickness of the LED 95 is 0.3 to 0.8 mm.

[0047] Thus, since the diode 85 has a thickness greater than the height of the spacer 76, that is, the distance between the membrane sheet 7 and the printed circuit board 8, it is physically difficult to place the diode 85 between the membrane sheet 7 and the printed circuit board 8. For this reason, it is conceivable to make the distance between the membrane sheet 7 and the printed circuit board 8 greater than the thickness of the diode 85. However, if the distance between the membrane sheet 7 and the printed circuit board 8 is made greater than the thickness of the diode 85, the pressing characteristics of the key switch device 100 in Figure 7 (relationship between key stroke and load) will change, and it will no longer be possible to provide the user with a good feel.

[0048] Therefore, as shown in Figures 8(A) and (C), by providing the diode 85 on the lower surface 82 of the printed circuit board 8, it is possible to avoid ghost input caused by simultaneous pressing of multiple keys while providing the user with a good tactile feel.

[0049] As shown in Figures 8(B) and (D), the diode 85 and the wiring 87 connecting the second contact 84 and the diode 85 may be provided on the upper surface 81 of the printed circuit board 8. In this case, the membrane sheet 7 has a first through-hole 75 that passes through the diode 85 at a position opposite to the diode 85. When the membrane sheet 7 has the first through-hole 75, even if the diode 85 is provided on the upper surface 81 of the printed circuit board 8, there is no need to change the distance between the membrane sheet 7 and the printed circuit board 8, so that ghost input caused by simultaneous pressing of multiple keys can be avoided while providing the user with a good feel.

[0050] Furthermore, as shown in Figures 8(C) and (D), the printed circuit board 8 has a second through-hole 88 that penetrates the printed circuit board 8, and the LED 95 may be placed inside the second through-hole 88. The LED 95 is electrically connected to wiring (not shown) on the lower surface 82 of the printed circuit board 8 and may be turned on and off. This can improve the aesthetic appearance of the keyboard 200 with illumination. Also, since the printed circuit board 8 is used instead of the lower film of the membrane switch, mounting the LED 95 is easy.

[0051] The membrane sheet 7 is made of, for example, a transparent PET (polyethylene terephthalate) film with a transmittance of 50% or more. If a transparent PET film with a transmittance of 90% or more is used, white printing may be applied to the upper surface 72 of the membrane sheet 7 to diffuse the milky white light upwards.

[0052] Figure 10(A) is a block diagram showing the connection relationship between the printed circuit board 8 and the computer 210, and Figure 10(B) is a circuit diagram of the keyboard controller 180 and switch matrix 181 included in the printed circuit board 8.

[0053] As shown in Figure 10(A), the printed circuit board 8 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.

[0054] As shown in Figure 10(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 10(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.

[0055] 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.

[0056] As described above, according to this embodiment, the keyboard 200 includes a slider 2 that can slide when a keytop 1 is pressed, a dome rubber 3 attached to the slider 2 that elastically buckles and deforms in response to the pressing operation of the keytop 1, a spring 4 attached to the slider 2 that opens and closes an electrical contact 71 in response to the sliding of the slider 2, a housing 5 that guides the slider 2, a membrane sheet 7, a printed circuit board 8, and a spacer 76 that forms a space between the membrane sheet 7 and the printed circuit board 8. Furthermore, the membrane sheet 7 has an upper surface 72 that is pressed down by the spring 4 in response to the sliding of the slider 2, and a lower surface 73 that is on the opposite side of the upper surface 72 and includes a conductive member 74. The printed circuit board 8 has a keyboard controller 180 having output ports 183a to 183d that output drive current and receiving ports 184a to 184d that receive current corresponding to the on or off state of the electrical contacts 71, a first contact 83 connected to the output ports 183a to 183d, a second contact 84 connected to the receiving ports 184a to 184d, and a diode 85 connected between the receiving ports 184a to 184d and the second contact 84, and faces the lower surface 73 of the membrane sheet 7. When the membrane sheet 7 is pressed down by the spring 4 in response to the sliding of the slider 2, the conductive member 74 comes into contact with the first contact 83 and the second contact 84, and the conductive member 74, the first contact 83 and the second contact 84 constitute the electrical contact 71.

[0057] Thus, unlike typical membrane switches, the keyboard 200 has a printed circuit board 8 with a diode 85 as the lower film of the membrane switch, which prevents current leakage caused by simultaneous pressing of multiple keys and allows for accurate detection of simultaneous pressing of multiple keys. Furthermore, since the spring 4 opens and closes the electrical contact 71 during the decrease in operating force F caused by the buckling deformation of the dome rubber 3, there is no discrepancy between the operating sensation and the contact-on operation, providing the user with a good feel.

[0058] Furthermore, in a typical membrane keyboard, a printed circuit board containing a keyboard controller that transmits a key code corresponding to the pressed key to the computer must be placed beneath the membrane switch, which includes an upper film, a lower film, and a spacer. In contrast, this embodiment does not have a lower film for the membrane switch. Therefore, the number of components can be reduced compared to a typical membrane keyboard.

[0059] If the diode 85 is placed on the upper surface 81 of the printed circuit board 8, the thickness of the diode 85 will increase the gap between the membrane sheet 7 and the printed circuit board 8, which may change the pressing characteristics of the key switch device 100 in Figure 7 and prevent the user from receiving a good tactile feel. In contrast, as shown in Figures 8(A) and (C), if the diode 85 is placed on the lower surface 82 of the printed circuit board, there is no need to change the gap between the membrane sheet 7 and the printed circuit board 8, so the pressing characteristics of the key switch device 100 in Figure 7 can be maintained, and the user can receive a good tactile feel.

[0060] As shown in Figures 8(B) and (D), by providing the membrane sheet 7 with a first through-hole 75 through which the diode 85 passes, even when the diode 85 is mounted on the upper surface 81 of the printed circuit board 8, there is no need to change the distance between the membrane sheet 7 and the printed circuit board 8. Therefore, a good feel can be provided to the user without changing the pressing characteristics of the key switch device 100 in Figure 7.

[0061] 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]

[0062] 1 Keycap, 2 Slider, 3 Dome rubber, 4 Spring, 5 Housing, 6 Switch panel, 7 Membrane sheet, 8 Printed circuit board, 74 Conductive components, 83 First contact, 84 Second contact, 85 Diode, 100 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 by pressing the operating member, A first elastic member is attached to the sliding member and undergoes elastic buckling deformation in response to the pressing operation of 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, A support member that guides the sliding member, A membrane sheet having a first surface that is pressed by the second elastic member, and a second surface that is on the opposite side of the first surface and includes a conductive member, A controller having an output port for outputting a drive current and a receiving port for receiving the current of the electrical contacts; a printed circuit board facing the second surface of the membrane sheet, having a first contact connected to the output port, a second contact connected to the receiving port, and a diode connected between the receiving port and the second contact; The system includes a spacer that forms a space between the membrane sheet and the printed circuit board, A keyboard characterized in that the conductive member contacts the first contact and the second contact in accordance with the sliding of the sliding member.

2. The printed circuit board has a third surface facing the second surface of the membrane sheet and a fourth surface on the opposite side of the third surface. The keyboard according to claim 1, characterized in that the first contact and the second contact are provided on the third surface, and the diode is provided on the fourth surface.

3. The printed circuit board has a third surface facing the second surface of the membrane sheet, The first contact, the second contact, and the diode are provided on the third surface. The keyboard according to claim 1, characterized in that the membrane sheet has a first through-hole that penetrates the diode at a position opposite to the diode.

4. The printed circuit board has a third surface facing the second surface of the membrane sheet, a fourth surface on the opposite side of the third surface, and a second through-hole penetrating the printed circuit board. The keyboard according to claim 1, characterized in that the keyboard comprises a lighting device disposed within the second through-hole and electrically connected to wiring provided on the fourth surface.

5. The keyboard according to any one of claims 1 to 4, characterized in that no wiring pattern is connected to the conductive member, and the conductive member is isolated from adjacent conductive members.

6. An operating device characterized by having the keyboard described in claim 5.

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