Keyboard device key

Abstract

To provide a key of a keyboard device, which can effectively suppress occurrence of shrinkage on an upper face of the key without damaging wood texture of the key, secures sufficient rigidity of the key and thus can obtain sufficient touch feeling.SOLUTION: A key of a keyboard device includes: a resin key body 51 which has at least an upper face part and a pair of side face parts and extends in a cross direction by a prescribed length; and one or a plurality of woody plates 52 attached along at least a part of the pair of side face parts of the key body 51. The key body 51 includes upper projection parts 53 which extend along each upper end of the pair of side face parts, are continuously formed with the upper face part and project toward sides of the key body 51. In the one or the plurality of woody plates 52, an upper end face is arranged to abut on lower faces of the upper projection parts 53, and a thickness size L1 in a vertical direction of the upper projection parts 53 is smaller than a thickness size L2 of the upper face part of the key body 51.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to keys for keyboard devices that are applied to keyboard instruments such as electronic pianos, and more particularly to keys for keyboard devices that have wooden boards attached to their sides. [Background technology]

[0002] Conventionally, there have been known keys for keyboard devices in which wooden members are attached to the sides of a resin key body to give the key a wood-like appearance at low cost. For example, Patent Document 1 discloses a configuration in which a key for a keyboard device includes a resin base member formed in a box shape with an open bottom, and a pair of rectangular wooden members disposed on the left and right sides of the base member, with at least one of the pair of wooden members having a thickness of 2 mm or more and 14.5 mm or less. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2018-112763 Summary of the Invention [Problem to be solved by the invention]

[0004] In the key of the keyboard device of Patent Document 1, the left and right ends of the upper plate of the base member protrude laterally beyond the side plate portions so that the upper end faces of the wooden members arranged on the left and right sides of the base member are not exposed to the outside, and the undersides of these protruding parts cover the upper end faces of the wooden members. With this configuration, the appearance of the key when viewed from the side is made to resemble a wooden key, giving the key a wooden texture.

[0005] However, because the thickness of the wooden members of the keys of this keyboard device is set to 2 mm or more, the protrusion length of both the left and right ends of the top plate is also 2 mm or more, resulting in a shape in which both the left and right ends of the top plate protrude further to the side than the side plates. With this type of shape, the connection between the top and side plates is thicker than the rest of the top plate, which causes differences in cooling speed during molding and causes uneven shrinkage of the resin material, making the top plate more susceptible to molding defects known as sink marks.

[0006] Because the top plate serves as the striking surface during playing, it is necessary to minimize the occurrence of sink marks to prevent deterioration of touch and aesthetics. Conventionally, in order to prevent the occurrence of sink marks at the joints between the top plate and the side plate, a measure has been taken to reduce the difference in cooling rate during molding by making the side plate thinner than the top plate. However, to effectively prevent the occurrence of sink marks in the top plate, the thickness of the side plate needs to be approximately half that of the top plate. As mentioned above, in order to make the appearance of a key from the side similar to that of a wooden key, the thickness of the top plate needs to be kept below a certain level. However, this results in a problem where the side plate is insufficiently thick, reducing the rigidity of the key and deteriorating the touch of the keyboard.

[0007] The present invention has been made to solve the above-mentioned problems, and aims to provide a key for a keyboard device that can effectively suppress the occurrence of sink marks on the top surface of the key without impairing the wooden texture of the key, while ensuring sufficient rigidity and thereby providing a good touch feeling. [Means for solving the problem]

[0008] In order to achieve the above object, the key of the keyboard device according to claim 1 comprises a resin key body 51 having at least an upper surface and a pair of side surfaces and extending a predetermined length in the front-to-rear direction, and one or more wooden boards 52 attached along at least a part of the pair of side surfaces of the key body 51, the key body 51 having an upper protrusion 53 extending along the upper end of each of the pair of side surfaces and formed continuously with the upper surface and protruding toward the side of the key body 51, the one or more wooden boards 52 being disposed so that the upper end surface of the one or more wooden boards 52 abuts against the lower surface of the upper protrusion 53, and the upper protrusion 53 has a thickness L1 in the up-down direction that is smaller than the thickness L2 of the upper surface of the key body 51. and the side protruding length dimension L3 is smaller than the thickness dimension L1 in the vertical direction. It is characterized by the fact that

[0009] According to this configuration, the upper protrusion, which is formed continuously with the upper surface of the key body, extends so as to protrude laterally along the upper end of the side surface, and the upper end surface of the wooden board is arranged so as to contact the lower surface of this upper protrusion, so that the upper end surface of the wooden board is covered by the upper protrusion and is not exposed to the outside.

[0010] By differentiating the thicknesses of the top surface of the key body and the upper protrusion, and making the vertical thickness of the upper protrusion smaller than the thickness of the top surface of the key body, the side appearance of the key can be made similar to that of a wooden key while allowing the thickness of the top surface to be set larger. This ensures a certain degree of thickness in the side surfaces, ensuring sufficient key rigidity, even when the thickness of the side surfaces is set to about half the thickness of the top surface to prevent sink marks from occurring in the top surface. Furthermore, by making the upper protrusion thinner than the top surface, the difference in cooling rate between the connection between the top surface and the side surfaces and the rest of the key during molding is reduced, further preventing sink marks from occurring in the top surface. Therefore, according to the present invention, it is possible to provide a keyboard device key that effectively prevents sink marks from occurring in the top surface of the key without compromising the wood texture of the key, while ensuring sufficient key rigidity and thereby providing a good touch.

[0013] AlsoBecause the lateral protrusion length of the upper protrusion is configured to be smaller than the vertical thickness of the upper protrusion, there is less of a difference in cooling rate between the connection between the top and side portions and other portions during molding, which reduces the occurrence of sink marks in the top portion. This also makes it possible to reduce the occurrence of sink marks without thinning the side portions to approximately half the thickness of the top portion, allowing the side portions to be set to a larger thickness, thereby improving the rigidity of the key. Therefore, according to the present invention, it is possible to provide a keyboard device key that effectively reduces the occurrence of sink marks in the top portion of the key without compromising the wood texture of the key, while ensuring sufficient rigidity of the key and thereby providing a good touch. [Brief explanation of the drawings]

[0014] [Figure 1] 1A and 1B are perspective views showing a part (for one octave) of a keyboard device of an electronic piano to which the present invention is applied, in which (a) shows the appearance of the keyboard device, and (b) shows a state in which keys other than the white and black keys on the left end are omitted. [Figure 2] 1(b) is a perspective view showing the keyboard device shown in FIG. 1(b) with the white keys and black keys, together with their respective key support mechanisms, removed from the keyboard chassis. FIG. [Figure 3] 1(b) is a cross-sectional view taken along line AA of the keyboard device shown in FIG. 1(b). [Figure 4] 1A and 1B are perspective views showing a white key and a key support mechanism, in which FIG. 1A shows the white key and the key support mechanism connected together, and FIG. 1B shows the white key and the key support mechanism disassembled. [Figure 5] 1A and 1B are perspective views showing the black key and the key support mechanism, in which FIG. 1A shows the black key and the key support mechanism connected together, and FIG. 1B shows the black key and the key support mechanism disassembled. [Figure 6] 1A and 1B are diagrams for explaining the operation of a white key in a keyboard device, in which FIG. 1A shows a key-released state and FIG. 1B shows a key-depressed state. [Figure 7] 1A and 1B are diagrams for explaining the operation of black keys in a keyboard device, in which (a) shows the key-released state and (b) shows the key-depressed state. [Figure 8]FIG. 2 is a perspective view showing a key body of a white key and a wooden board attached to its side. [Figure 9] (a) is a perspective view of the key body with the wooden board attached, and (b) is a cross-sectional view along line BB. DETAILED DESCRIPTION OF THE INVENTION

[0015] A preferred embodiment of the present invention will be described in detail below with reference to the drawings. Figure 1(a) shows only one octave of a keyboard device 1 of an electronic piano to which the present invention is applied. In the following explanation, the basic configuration and operation of the keyboard device 1 will be explained first, and then the main parts of the present invention will be explained.

[0016] Figure 1(b) shows the keyboard device 1 of Figure 1(a) with all keys 2 omitted except for the white key 2a and black key 2b on the left end, and Figure 2 shows the white key 2a and black key 2b removed from the keyboard chassis 4 together with the key support mechanism 6.

[0017] This keyboard device 1 includes a keyboard chassis 4, a plurality of keys 2 consisting of white keys 2a and black keys 2b arranged in a row in the left-right direction, a key support mechanism 6 rotatably attached to the keyboard chassis 4 for each key 2 and supporting the corresponding key 2 from below, and a key switch 3 for detecting key depression information for each key 2.

[0018] The keyboard chassis 4 includes a chassis main body 4a made of a resin molded product of a predetermined shape, obtained by injection molding a predetermined resin material (e.g., ABS resin). As shown in Figure 3, the chassis main body 4a has a front portion 11, a middle portion 12, and a rear portion 13, all of which are formed to extend in the left-right direction (the left-right direction in Figure 3(a)) as a whole, and are integrally formed with a plurality of ribs 14 spaced apart in the left-right direction and each extending in the front-to-rear direction. In the following description, the front portion 11, middle portion 12, and rear portion 13 of the chassis main body 4a of the keyboard chassis 4 will be referred to as the "chassis front portion 11," the "chassis middle portion 12," and the "chassis rear portion 13," respectively.

[0019] The chassis front section 11 primarily guides the white keys 2a when they are pressed and regulates the upper and lower limit positions of their front ends. A plurality of white key guides 11a are arranged side-by-side in the left-right direction on the chassis front section 11. Each white key guide 11a is inserted from below into the corresponding white key 2a to prevent the white key 2a from swaying sideways. The chassis front section 11 also has engagement holes 11b, 11b penetrating vertically on both the left and right sides of each white key guide 11a. Two upper limit position regulation sections 21, 21 (described later) of the white key 2a penetrate the engagement holes 11b, 11b, respectively. Furthermore, the chassis front section 11 is provided with a stopper mounting section 11c at its front end, which protrudes forward and extends laterally across the entire chassis body 4a. An upper limit key stopper 16a and a lower limit key stopper 16b for the white keys are attached to the lower and upper surfaces of the stopper mounting section 11c, respectively, so as to extend laterally. In addition, a stopper mounting portion 11d for the black keys is provided at a predetermined position behind the white key guide 11a on the front part 11 of the chassis, extending in the left-right direction across the entire chassis body 4a, and an upper key limit stopper 17 for the black keys is attached to this stopper mounting portion 11d so as to extend in the left-right direction.

[0020] The chassis intermediate section 12 primarily guides the black keys 2b when pressed and swingably supports the first and second arms 31 and 32 (described later) of the key support mechanisms 6a, 6b for the white and black keys. The chassis intermediate section 12 includes a flat section 12a extending laterally and a plurality of black key guides 12b arranged vertically on the flat section 12a and spaced apart appropriately in the left-right direction. Each black key guide 12b is inserted into each black key 2b from below to prevent the key from swaying laterally. The front of the chassis intermediate section 12 includes a first arm support section 18 that supports the first arm 31 of the key support mechanism 6. The first arm support section 18 includes a plurality of first support shafts 18a extending laterally between adjacent ribs 14. The first arms 31 are swingably supported by these first support shafts 18a. Furthermore, a second arm support section 19 that supports a second arm 32 of the key support mechanism 6 is provided at the rear of the chassis intermediate section 12. This second arm support section 19 has a plurality of second support shafts 19a that are provided between adjacent ribs 14, 14 and extend in the left-right direction. The plurality of second support shafts 19a are arranged on the same axis that extends in the left-right direction, at a position rearward and higher than the first support shaft 18a, and the second arm 32 is supported by these second support shafts 19a so that it can swing freely. Note that a first arm lower limit stopper 10b that extends in the left-right direction across the entire chassis main body 4a is provided at a predetermined position on a middle rail 8 (described later) that is provided below the chassis intermediate section 12.

[0021] The key switch 3 is attached to the bottom of the keyboard chassis 4, between the chassis front section 11 and the chassis middle section 12. The key switch 3 is composed of a horizontally elongated printed circuit board 3a extending in the left-right direction, and multiple switch bodies 3b made of rubber switches attached to the printed circuit board 3a for each key 2 and pressed by a first arm 31 when the key is pressed.

[0022] The chassis rear section 13 primarily guides the key 2 vertically at its rear end while preventing lateral movement, and regulates the upper limit position of the rear end of the first arm 31. As shown in FIGS. 2 and 3(a), the chassis rear section 13 has multiple partition walls 13a spaced at predetermined intervals in the left-right direction to separate adjacent keys 2. Also, as shown in FIG. 3(b), a first arm upper limit stopper 10a extending left-right across the entire chassis main body 4a is provided at a predetermined position on the upper part of the chassis rear section 13. This first arm upper limit stopper 10a and the first arm lower limit stopper 10b provided on the chassis intermediate section 12 regulate the upper limit position and the lower limit position, respectively, of the first arm 31, which functions as a hammer for applying a touch weight to the key 2, when the first arm 31 rotates upward and downward. Furthermore, a metal cover plate 15 is attached to the upper part of the chassis rear part 13, extending in the left-right direction across the entire chassis body 4a and arranged to cover the rear end of the key 2.

[0023] 2 and 3(a), the chassis main body 4a of the keyboard chassis 4 configured as described above is provided with a plurality of first openings 5a that open upward and forward, and a plurality of second openings 5b that also open upward. The first arm 31 of the key support mechanism 6 engages with the first support shaft 18a from the outside through each of the first openings 5a, and the second arm 32 engages with the second support shaft 19a from the outside through each of the second openings 5b.

[0024] In the keyboard chassis 4, multiple chassis bodies 4a are connected to one another in a line up in the left-right direction, and are placed on and screwed to metal front rails 7, middle rails 8, and rear rails 9 that extend left-right and are arranged at a predetermined distance from one another in the front-to-rear direction. The keyboard chassis 4 is then fixed to a shelf board (not shown) of the electronic piano via the front rails 7 and rear rails 9.

[0025] Next, the key 2 and the key support mechanism 6 will be described. FIG. 4(a) shows an enlarged view of the white key 2a and its key support mechanism 6a, while FIG. 4(b) shows them exploded. As shown in the figure, the white key 2a is formed by injection molding a specific resin material (e.g., AS resin) to extend a specific length in the front-to-rear direction and to have a hollow shape that opens downward. The front end of the white key 2a is provided with a pair of left and right upper limit position restrictors 21, 21 that extend downward from the left and right side walls and are formed so that their lower ends are bent forward. As described above, these upper limit position restrictors 21, 21 are engaged in a state in which they penetrate the left and right engagement holes 11b, 11b of the chassis front part 11, respectively.

[0026] Additionally, a front-key connecting portion 22 is provided at the front of the white key 2a, at a predetermined position rearward of the upper limit restriction portion 21, to connect to the first arm 31 of the key support mechanism 6a. This front-key connecting portion 22 has a U-shaped connecting recess 22a with an elongated side surface that opens forward. A key-side noise suppression member 20 is attached to this connecting recess 22a, covering its entire inner circumferential surface, to suppress noise generated when a connecting shaft 35b (described later) of the first arm 31 slides within the connecting recess 22a.

[0027] Furthermore, a key rear connector 23 is provided at the rear of the white key 2a, which is connected to the second arm 32 of the key support mechanism 6a. This key rear connector 23 hangs down from the center of the white key 2a in the left-right direction and has a plate-like connector body 23a with a predetermined thickness in the left-right direction, and a pair of left and right engaging protrusions 23b, 23b that protrude coaxially from the left and right sides of the connector body 23a. In addition, a tool insertion hole 24 is formed at the rear of the white key 2a, penetrating vertically. This tool insertion hole 24 is used to insert a predetermined tool from above when releasing the connection between the white key 2a and the second arm 32 of the key support mechanism 6a, for example during maintenance of the keyboard device 1.

[0028] On the other hand, the key support mechanism 6a includes a first arm 31 and a second arm 32 that are engaged with each other and connected to the front-key connecting portion 22 and the rear-key connecting portion 23 of the white key 2a, respectively.

[0029] As shown in FIG. 4(b), the first arm 31 is composed of an arm body 33 and two weights 34, 34 attached to the arm body 33. The arm body 33 is a resin molded product of a predetermined shape, typically obtained by injection molding a predetermined resin material (e.g., polyacetal). The arm body 33 extends a predetermined length in the front-to-rear direction, and its front end is provided with a first-arm front connector 35 that connects to the front-side connector 22 of the white key 2a. The first-arm front connector 35 has a box-shaped box portion 35a that opens upward and forward, and a connecting shaft 35b that extends left and right and connects the front upper ends of the left and right side walls of the box portion 35a. The connecting shaft 35b is connected to the connecting recess 22a of the front-side connector 22 of the white key 2a so as to be rotatable and slidable in the front-to-rear direction.

[0030] The arm main body 33 also has a U-shaped bearing 36 with a downwardly open side at a predetermined position immediately rearward of the first arm front connecting portion 35, and this bearing 36 rotatably engages with the first support shaft 18a of the keyboard chassis 4. Furthermore, the arm main body 33 has a first arm rear connecting portion 37 at a predetermined position rearward of the bearing 36, which connects to the second arm 32. Specifically, the first arm rear connecting portion 37 has a connecting shaft 37a that extends in the left-right direction and has both ends that protrude outward beyond the left and right side surfaces of the arm main body 33. Both ends of this connecting shaft 37a engage with connecting recesses 45b, 45b of a second arm front connecting portion 45 of the second arm 32, which will be described later.

[0031] Two elongated plate-like weights 34, 34 are attached to weight attachment portion 38 at the rear of arm main body 33, sandwiching weight attachment portion 38 from both sides. Each weight 34 is made of a material (e.g., a metal such as iron) with a higher specific gravity than arm main body 33, and is formed into a predetermined shape by pressing a metal plate, for example.

[0032] The second arm 32 is made of a resin molded product of a predetermined shape, which is injection molded from the same resin material as the arm body 33 of the first arm 31. The second arm 32 is shorter than the first arm 31 and extends a predetermined length in the front-to-rear direction. The second arm 32 also has a C-shaped bearing portion 41 near the center in the longitudinal direction, with the side surface opening forward, and this bearing portion 41 rotatably engages with the second support shaft 19a of the keyboard chassis 4.

[0033] Additionally, a second-arm rear connecting portion 42 that connects to the key rear connecting portion 23 of the white key 2a is provided at the rear of the second arm 32. This second-arm rear connecting portion 42 is bifurcated, with two left and right connecting arms 43, 43 that extend parallel to each other a predetermined length along the length of the second arm 32. A connecting hole 43a that penetrates in the left-right direction is formed at the rear end of each connecting arm 43. Between their rear ends, the connecting arms 43, 43 sandwich the connecting main body 23a of the key rear connecting portion 23 of the white key 2a, and each connecting hole 43a rotatably fits into the corresponding engaging protrusion 23b of the key rear connecting portion 23.

[0034] Furthermore, a second arm front connecting portion 45 is provided on the front portion of the second arm 32, which is connected to the first arm rear connecting portion 37 of the first arm 31. This second arm front connecting portion 45 has a pair of left and right connecting pieces 45a, 45a spaced a predetermined distance from each other in the left-right direction, and each connecting piece 45a is formed with a U-shaped connecting recess 45b whose side surface is elongated and open forward. The left and right connecting pieces 45a, 45a of the second arm front connecting portion 45 are rotatably and slidably engaged with both ends of the connecting shaft 37a of the first arm 31 via the connecting recesses 45b, 45b, respectively.

[0035] FIG. 5(a) shows an enlarged view of the black key 2b and its key support mechanism 6b, while FIG. 5(b) shows them in exploded view. The black key 2b is injection-molded from the same resin material as the white key 2a. It is shorter than the white key 2a, extends a predetermined length in the front-to-back direction, and is hollow and open downward. The front lower end of the black key 2b is provided with a front-side connecting portion 26, which is formed in a manner similar to the front-side connecting portion 22 of the white key 2a. This front-side connecting portion 26 has a connecting recess 26a that is elongated and U-shaped and opens forward. The front-side connecting portion 26 also has an extension 26b at the front end below the connecting recess 26a, which extends a predetermined length forward beyond the front surface of the black key 2b. This extension 26b functions as an upper limit position limiter for the black key 2b. In the following description, the same components of the black key 2b and key support mechanism 6b as those of the white key 2a and key support mechanism 6a are designated by the same reference numerals, and detailed description thereof will be omitted.

[0036] The key support mechanism 6b that supports the black keys 2b is configured in a manner similar to the key support mechanism 6a for white keys described above. Specifically, the arm body 33 of the first arm 31 and the second arm 32 of the key support mechanism 6b are configured to be identical in shape and size to the arm body 33 and second arm 32 of the key support mechanism 6a for white keys. However, the two weights 34, 34 on the left and right of the key support mechanism 6b for black keys have a different rear shape than the weight 34 of the key support mechanism 6a for white keys.

[0037] Next, we will explain the operation of the keys 2 and key support mechanism 6 in the keyboard device 1 configured as above. Figure 6 shows the operation of the white keys 2a and their key support mechanism 6a, and Figure 7 shows the operation of the black keys 2b and their key support mechanism 6b.

[0038] 6(a), when the player presses down on the front end of the white key 2a with his / her finger, the front-key connector 22 of the white key 2a moves downward, causing the first arm 31 to rotate counterclockwise around the first support shaft 18a. Accompanying the rotation of the first arm 31, the front-key connector 45 of the second arm, which engages with the connecting shaft 37a of the first arm 31 via the connecting recess 45b, moves upward. This causes the second arm 32 to rotate clockwise around the second support shaft 19a. Accompanying the rotation of the second arm 32, the rear-key connector 23 connected via the rear-key connector 42 at its rear end is pulled down, causing the rear end of the white key 2a to move downward.

[0039] During the above-described rotation of the first arm 31, as the box portion 35a of the first arm front connecting portion 35 moves downward, the bottom wall of the box portion 35a presses from above against the switch body 3b of the key switch 3 corresponding to the pressed key 2. As a result, the electronic piano detects key press information of the pressed key 2, and a sound is generated from a speaker (not shown) based on the detected key press information.

[0040] As described above, when the white key 2a is pressed down, as the first arm 31 rotates counterclockwise, the weight 34 of the first arm 31 tilts upward at the rear as shown in Figure 6(b), and its rear end abuts against the first arm upper limit stopper 10a from below, thereby preventing further rotation of the first arm 31. Then, when the front end of the white key 2a is pressed down to the lowest position, the front end of the white key 2a abuts against the key lower limit stopper 16b, preventing further depression of the white key 2a.

[0041] When the white key 2a is pressed as described above, it rotates around an imaginary fulcrum P located behind its rear end. The position of this imaginary fulcrum P is set, for example, so that the distance from the front end of the white key 2a is approximately twice the length of the white key 2a itself. As a result, when the front end of the white key 2a is pressed down to the lowest position, the front end of the white key 2a is positioned a predetermined keystroke (e.g., 10 mm) lower, and the rear end of the white key 2a is positioned approximately half the keystroke (e.g., 5 mm) lower, compared to when the key is released as shown in Figure 6(a).

[0042] On the other hand, when the pressed white key 2a is released, the weight of the weight 34 causes the first arm 31 of the key support mechanism 6a to rotate in the opposite direction to that described above, and accordingly, the second arm 32 also rotates in the opposite direction to that described above. As a result, the white key 2a rotates upward around the imaginary fulcrum P. Then, a predetermined portion of the first arm 31 behind the first support shaft 18a abuts against the first arm lower limit stopper 10b from above, and both upper limit position restriction portions 21, 21 of the white key 2a abut against the key upper limit stopper 16a from below, preventing further rotation of the white key 2a and returning it to its original key-released state.

[0043] Furthermore, the operation of the black key 2b when pressed is similar to that of the white key 2a and key support mechanism 6a described above. Specifically, when the front end of the black key 2b is depressed in the key-released state shown in FIG. 7(a), the first arm 31 rotates counterclockwise around the first support shaft 18a, and the second arm 32 rotates clockwise around the second support shaft 19a, causing the black key 2b to rotate around a virtual fulcrum Q at the rear. Similar to the virtual fulcrum P of the white key 2a described above, the position of this virtual fulcrum Q is set so that its distance from the front end of the black key 2b is approximately twice the length of the black key 2 itself. Therefore, when the front end of the black key 2b is depressed to its lowest position, the front end of the black key 2b is positioned a predetermined keystroke lower than in the key-released state shown in FIG. 7(a), and the rear end of the black key 2b is positioned approximately half the keystroke lower.

[0044] On the other hand, when the pressed black key 2b is released, the first arm 31 and the second arm 32 of the key support mechanism 6b rotate in the opposite direction, causing the black key 2b to rotate upward around the virtual fulcrum Q. Then, the extension 26b of the front-key connecting portion 26 of the black key 2b abuts against the upper key stopper 17 from below, preventing further rotation of the black key 2b and returning it to its original released state.

[0045] Next, the main part of the present invention will be described with reference to Figures 8 and 9. The main part of the present invention is the structure around the top and side surfaces of the key body to which the wooden board is attached. In this embodiment, an example in which this structure is applied to a white key will be described, but a similar structure may also be applied to a black key.

[0046] FIG. 8 shows the key body 51 of a white key 2a and the wooden board attached to its side. As described above, the key body 51 of the white key 2a is formed by injection molding a predetermined resin material (e.g., AS resin). In this embodiment, the white key 2a is, for example, an A key (the key for the note A). The key body 51 of the white key 2a consists of a wide portion 51a adjacent to another white key 2a and a narrow portion 51b adjacent to the black key 2b. Wooden boards 52 are attached to the left and right side portions of each of the wide portion 51a and the narrow portion 51b. The wooden board 52 can be made of wood, or other wood materials such as wood-grain veneer, plywood, and medium-density fiberboard (MDF). In this embodiment, the wooden board 52 is made of soft wood with a specific gravity of 0.5 or less. Examples of such wood include spruce and certain tropical woods.

[0047] The thickness of the wooden board 52 is set to be approximately the same as the length L3 of the upper protrusion 53, which protrudes laterally from the key body 51. As will be described later, in this embodiment, this length is set to approximately 1.8 mm. This makes the upper protrusion 53 and the wooden board 52 approximately flush, giving the key an aesthetic appearance similar to that of a wooden key when viewed from the side.

[0048] Fig. 9(a) shows the key body 51 with the wooden board 52 attached. As shown in Figs. 8 and 9(a), upper protrusions 53 that protrude toward the sides of the key body 51 are formed at the upper ends of the side surfaces of the key body 51. In this embodiment, the upper protrusions 53 are provided on the left and right side surfaces of the wide portion 51a and the narrow portion 51b. The upper protrusions 53 are formed continuously with the top surface of the key body 51 and extend along the upper ends of the side surfaces of the wide portion 51a and the narrow portion 51b.

[0049] Figure 9(b) is a cross-sectional view taken along line BB in Figure 9(a). As shown in the figure, the upper end surface of the wooden board 52 is attached so as to abut against the lower surface of the upper protrusion 53 with almost no gap between them. As a result, the upper end surface of the wooden board 52 is covered by the upper protrusion 53 and cannot be seen from the outside.

[0050] The key body 51, which is a molded product made of resin, requires careful attention to prevent sink marks in thicker areas, such as the connection between the top and side surfaces. Since the top surface of the key body 51 is the striking surface during playing, it is particularly important to effectively prevent sink marks from occurring on the top surface to prevent deterioration of aesthetics and touch during playing. One effective way to prevent sink marks on the top surface of the key body 51 is to thin the side surfaces of the key body 51 to about half the thickness of the top surface, thereby reducing the difference in cooling rate during molding. However, this results in an insufficient thickness on the side surfaces, which reduces the rigidity of the key and results in a poor touch.

[0051] To solve this problem, the key body 51 of this embodiment is characterized in that the thickness L1 of the upper protrusion 53 in the vertical direction is made different from the thickness L2 of the top surface of the key body 51, and the thickness L1 of the upper protrusion 53 is formed to be smaller than the thickness L2 of the top surface. This point will be described in detail below.

[0052] First, the thickness in the vertical direction of upper protrusion 53 is set to a thickness such that the appearance of the key when viewed from the side resembles the appearance of a wooden key due to the combination of upper protrusion 53 and wood board 52. In this embodiment, thickness dimension L1 of upper protrusion 53 is set to approximately 2 mm so that the appearance resembles the wooden keys of a normal acoustic piano.

[0053] Meanwhile, as described above, the thickness L2 of the top surface of the key body 51 is configured to be larger than the thickness L1 of the upper protrusion 53. By increasing the thickness L2 of the top surface, even if the thickness of the side surface must be approximately half the thickness L2 of the top surface to prevent sink marks, a certain degree of thickness can be ensured in the side surface, and sufficient rigidity can be ensured for the entire key.

[0054] Furthermore, by making the thickness L1 of the upper protrusion 53 smaller than the thickness L2 of the top surface portion, there is also the advantage that the difference in cooling rate between the connection portion between the top surface portion and the side surface portion and the other portions during molding is reduced. This further reduces the occurrence of sink marks on the top surface portion. In this embodiment, the thickness L2 of the top surface portion is set to approximately 2.8 mm.

[0055] Another feature of the key body 51 of this embodiment is that the lateral protrusion length L3 of the upper protrusion 53 is smaller than the thickness L1 of the upper protrusion 53. This configuration reduces the difference in cooling rate between the connection between the top and side surfaces and the remaining parts during molding, thereby suppressing the occurrence of sink marks in the top surface. This also prevents the occurrence of sink marks without thinning the side surfaces to approximately half the thickness of the top surface. This allows the thickness of the side surfaces to be increased, thereby improving the rigidity of the key. In this embodiment, the protrusion length L3 of the upper protrusion 53 is set to approximately 1.8 mm.

[0056] As described above, according to this embodiment, the thickness dimension L1 of the upper protrusion 53 is formed to be smaller than the thickness dimension L2 of the top surface portion, thereby giving the appearance of the key when viewed from the side an aesthetic appearance similar to that of a wooden key, and at the same time, by increasing the thickness dimension L2 of the top surface portion, a certain degree of thickness can be ensured in the side portion, thereby ensuring sufficient rigidity for the key as a whole.

[0057] Furthermore, by forming the lateral protrusion length dimension L3 of upper protrusion 53 to be smaller than the thickness dimension L1 of upper protrusion 53, it is possible to suppress the occurrence of sink marks on the upper surface. Furthermore, since the thickness dimension of the side surface can be set larger, the rigidity of the key can be improved.

[0058] Therefore, according to this embodiment, it is possible to provide a key for a keyboard device that can effectively suppress the occurrence of sink marks on the top surface of the key without impairing the wooden texture of the key, while ensuring sufficient rigidity of the key and thereby providing a good touch feeling.

[0059] The present invention is not limited to the above-described embodiment, and can be embodied in various forms. For example, in the embodiment, the thickness dimension L1 of the upper protrusion 53 is formed to be smaller than the thickness dimension L2 of the upper surface portion, and the lateral protrusion length dimension L3 of the upper protrusion 53 is formed to be smaller than the thickness dimension L1 of the upper protrusion 53. However, it is also possible to adopt only one of these configurations. In addition, the detailed configuration can be changed as appropriate within the scope of the spirit of the present invention. [Explanation of symbols]

[0060] 1 Keyboard device 2 keys 2a white key 2b black key 51 Key body 51a wide part 51b Narrow part 52 Wood board 53 Upper protrusion L1 Thickness of upper protrusion L2 Thickness of the top surface of the key body L3 Projection length of upper protrusion

Claims

[Claim 1] a resin key body having at least a top surface portion and a pair of side surfaces and extending a predetermined length in the front-rear direction; one or more wooden boards attached along at least a portion of the pair of side surfaces of the key body, The key body includes upper protrusions extending along upper ends of the pair of side surfaces and formed continuously with the upper surface, the upper protrusions protruding toward the sides of the key body, The one or more wood boards are arranged so that their upper end surfaces abut against the lower surface of the upper protrusion, A key for a keyboard device, characterized in that the upper protrusion has a thickness dimension in the vertical direction that is smaller than the thickness dimension of the top surface of the key body, and the protrusion length dimension to the side is smaller than the thickness dimension in the vertical direction.

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