Keyboard device for keyboard instruments

Abstract

To provide a keyboard device of a keyboard instrument, which can reduce occurrence of noise and can quickly stop a key when the pressed key returns to an original position before key pressing.SOLUTION: A keyboard instrument includes: a keyboard chassis 4 which has an upper limit stopper 16a; a key 2 which extends in a longitudinal direction by a prescribed length and is arranged above the keyboard chassis 4; and a key support mechanism 6 which supports the key 2 from below and operates the pressed key 2 to rotate around a virtual fulcrum P positioned behind when the key is pressed. The key 2 has an upper limit position regulation part 21 which is provided at a lower part of a front end and regulates an upper limit position of the key 2 by being brought into contact with the upper limit stopper 16a from below in a key release state. The keyboard instrument further includes a key back side stopper 51 which is provided in the keyboard chassis 4 and to which a back end part 52 of the key 2 contacts from below before the upper limit position regulation part 21 contacts the upper limit stopper 16a when the key 2 returns to an original position before key pressing.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a keyboard device that is applied to keyboard instruments such as electronic pianos, and that operates so that a depressed key rotates around a virtual fulcrum located behind its rear end. [Background technology]

[0002] A keyboard device of this type is known, for example, from Patent Document 1. In this keyboard device, keys extending in the front-to-rear direction are arranged on top of a keyboard chassis. A stopper piece extending downward and bending forward at its lower end is provided at the front end of the key. The rear end of the key is supported by a key support member, so that when the key is pressed, the key rotates downward around a virtual fulcrum located behind the rear end of the key. A rotatable hammer arm is provided below the key, which rotates in conjunction with the key being pressed.

[0003] In a keyboard device configured in this way, when a key is pressed down, it moves downward in a generally parallel fashion. In this case, the hammer arm below the key is rotated in a predetermined direction by the depressed key. When the key is released, the hammer arm rotates in the opposite direction, and the key, which was pushed up in conjunction with this rotation, returns to its original position before it was pressed. In this case, a stopper piece provided below the front end of the key abuts from below against an upper limit stopper provided on the keyboard chassis, preventing further upward movement. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 10-340079 (Figs. 1 and 2) Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-described keyboard device, when a pressed key returns to its original position, the key is pushed up forcefully by the rotating hammer arm, which can cause the stopper piece at the front end of the key to hit the upper limit stopper hard. When the stopper piece of the key hits the upper limit stopper hard, noise is generated. Of course, it is possible to suppress this noise by using a relatively soft cushion as the upper limit stopper. However, this can cause the upper limit positions of multiple keys lined up horizontally to not align. In addition, the hammer arm is more likely to bounce when returning to its original position, which can cause the key to not immediately stop when returned to its original position, or can generate mechanical noise in various parts of the key and hammer arm.

[0006] The present invention has been made to solve the above-mentioned problems, and aims to provide a keyboard device for a keyboard instrument that can reduce noise when a pressed key returns to its original position before the key was pressed and can quickly stop the key. [Means for solving the problem]

[0007] In order to achieve the above object, the invention according to claim 1 comprises a keyboard chassis having an upper limit stopper, a key extending a predetermined length in the front-rear direction and arranged on the upper part of the keyboard chassis, and a key support mechanism that engages with the keyboard chassis and is provided to support the key from below, and that, when a key is pressed, moves the pressed key to rotate around a virtual fulcrum located behind the rear end of the key, This key's The key has an upper limit position regulating section provided at the bottom of the front end, which regulates the upper limit position of the key by contacting the upper limit stopper from below when the key is released, and is further provided with a key rear stopper provided on the keyboard chassis, which the rear end of the key contacts from below before the upper limit position regulating section contacts the upper limit stopper when the key returns to its original position before it was pressed.

[0008] According to this configuration, when a key supported from below by the key support mechanism is pressed, the key rotates around a virtual fulcrum at the rear. In this case, the pressed key moves downward as a whole, so that the front and rear ends of the key are positioned lower than their original positions before being pressed. When the pressed key is released and the key returns to its original position, the rear end of the key abuts against the key rear stopper provided on the keyboard chassis from below before the upper limit limiting portion provided on the lower part of the front end of the key abuts against the upper limit stopper provided on the keyboard chassis from below. In other words, the upper limit limiting portion of the front end of the key abuts against the upper limit stopper after the rear end of the key abuts against the upper limit stopper. This reduces the speed and impact when the upper limit limiting portion of the front end of the key hits the upper limit stopper, significantly reducing the noise generated when the upper limit limiting portion of the key hits the upper limit stopper and quickly stopping the key after it has returned to its original position before being pressed. In addition, the quick stopping of the keys improves the ability to repeatedly press the keys and provides a good touch feeling.

[0009] The invention of claim 2 is characterized in that, in the keyboard device of the keyboard instrument described in claim 1, the rear end of the key has a contact surface that contacts the rear key stopper in the key-released state, and a convex portion formed to protrude upward from this contact surface.

[0010] With this configuration, the rear end of the key is provided with the above-mentioned contact surface and protrusion, and when they contact the key rear stopper from below, the protrusion hits first, followed by the contact surface. In other words, rather than the contact surface hitting the key rear stopper immediately, the protrusion, which has an upper surface smaller than the contact surface, hits the key rear stopper first, thereby reducing the impact noise when the rear end of the key hits the key rear stopper.

[0011] The invention according to claim 3 is the keyboard device for a keyboard instrument according to claim 2, wherein the convex portion is This convex part The upper surface is inclined relative to the contact surface or formed in an upwardly convex arc shape.

[0012] With this configuration, the upper surface of the convex portion is inclined relative to the abutment surface or is formed in an upwardly convex arc, so that when the convex portion abuts against the rear key stopper, the upper surface of the convex portion abuts against the rear key stopper gradually, which further reduces the impact noise when the upper surface of the convex portion abuts against the rear key stopper compared to when the entire upper surface of the convex portion abuts against the rear key stopper at once.

[0013] The invention of claim 4 is characterized in that, in the keyboard device of a keyboard instrument described in any one of claims 1 to 3, it further comprises a stopper support plate attached to the upper part of the rear end of the keyboard chassis, and the key rear stopper is fixed to the front end of the underside of the stopper support plate.

[0014] According to this configuration, the key rear stopper is fixed to the front end of the underside of the support plate attached to the top of the rear end of the keyboard chassis, so that the key rear stopper can be firmly attached to the keyboard chassis and can be easily positioned in an appropriate position. [Brief explanation of the drawings]

[0015] [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] 1A and 1B are enlarged views showing the rear end of a key and its surroundings in a keyboard device, in which FIG. 1A shows the key in a released state and FIG. 1B shows the key in a pressed state. [Figure 9] The figures show the appearance of the white keys, with (a) being a perspective view and (b) being a right side view. [Figure 10] FIG. 10(a) is a right side view showing the rear end of the key, and (b) to (d) are diagrams for explaining modified examples of the protrusion. DETAILED DESCRIPTION OF THE INVENTION

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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).

[0043] 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.

[0044] 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.

[0045] 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.

[0046] Next, the main part of the present invention will be described with reference to Figures 8 to 10. The main part of the present invention is that the rear end of the keyboard chassis 4 is provided with a key rear stopper 51 against which the rear end of the key 2 abuts from below.

[0047] Figure 8 shows an enlarged view of the rear end 52 of the key 2 and its surroundings from Figures 6 and 7, with (a) showing the key released and (b) showing the key pressed. As shown in Figure 8, the key rear stopper 51 is adhesively fixed to the front end of the underside of the cover plate 15 (stopper support plate). This key rear stopper 51 is made of an elastic material and is formed in a block shape that extends across the entire cover plate 15 in the left-right direction and has a predetermined thickness in the up-down direction.

[0048] 9 shows the white key 2a, with (a) being a perspective view and (b) being a right side view. Note that the rear end 52 of the white key 2a and the black key 2b has the same structure, so in the following explanation, the white key 2a will be used as a representative of the keys 2.

[0049] As shown in Figure 9, the rear end 52 of the key 2 has a width dimension in the left-right direction that is shorter than the width dimension of its front portion. The upper surface of the rear end 52 of the key 2 is integral with the upper surface of the key 2 itself and forms a contact surface 52a that contacts the key rear stopper 51 from below when the key is released. Furthermore, the rear end of the key 2 is provided with a protrusion 53 that extends along the length of the key 2 on contact surface 52a and protrudes upward from contact surface 52a. The upper surface of this protrusion 53 is formed parallel to contact surface 52a and has a smaller area than contact surface 52a.

[0050] 8, in this keyboard device 1, a key rear stopper 51 is installed at a predetermined position above the rear chassis section 13 via a cover plate 15. As shown in Fig. 8(a), in the key-released state, the contact surface 52a and the protrusion 53 of the rear end portion 52 of the key 2 contact the key rear stopper 51 from below. On the other hand, as shown in Fig. 8(b), in the key-depressed state, the rear end portion 52 of the key 2 moves downward, causing the contact surface 52a and the protrusion 53 to move downward away from the key rear stopper 51.

[0051] When the pressed key 2 is released and returns to its original position, the contact surface 52a of the rear end 52 of the key 2 contacts the key rear stopper 51 from below before the upper limit position restricting portions 21, 21 at the front end of the key 2 contact the key upper limit stopper 16a from below. In this case, the convex portion 53 contacts the key rear stopper 51 before the contact surface 52a of the key 2 contacts. Note that for the black key 2b, the above-mentioned extension portion 26b and the black key upper limit stopper 17 correspond to the upper limit position restricting portion 21 and the key upper limit stopper 16a for the white key 2a.

[0052] As described above, with the keyboard device 1 incorporating the essential components of the present invention, when a pressed key 2 returns to its original position before the key was pressed, the rear end 52 of the key 2 abuts against the rear key stopper 51 before the upper limit position restricting portions 21, 21 at the front end of the key 2 abut against the upper key limit stopper 16a, thereby reducing the speed and impact when the upper limit position restricting portions 21, 21 of the key 2 abut against the upper key limit stopper 16a. As a result, noise generated by the upper limit position restricting portions 21, 21 of the key 2 abutting against the upper key limit stopper 16a can be significantly reduced, and the key 2 can be quickly stopped after returning to its original position before the key was pressed. In addition, the quick stopping of the key 2 improves the ability to repeatedly play the key 2 and provides a good touch feeling.

[0053] Furthermore, when rear end 52 of key 2 abuts against key rear stopper 51 from below, convex portion 53 abuts first, followed by abutment surface 52a. In other words, rather than abutment surface 52a abutting against key rear stopper 51 immediately, convex portion 53, which has an upper surface area smaller than abutment surface 52a, abuts against key rear stopper 51 first, thereby reducing the impact noise when rear end 52 of key 2 abuts against key rear stopper 51.

[0054] The present invention is not limited to the above-described embodiment and can be embodied in various forms. For example, in the above-described embodiment, the upper surface of the protrusion 53 at the rear end 52 of the key 2 is formed parallel to the abutment surface 52a. However, the present invention is not limited to this, and various shapes of the upper surface of the protrusion 53 can be adopted.

[0055] FIG. 10(a) shows a right side view of the rear end portion 52 of the key 2, and FIGS. 10(b) to 10(d) show modified examples of the protrusion 53. As shown in FIG. 10(a), the upper surface of the protrusion 53 is parallel to the contact surface 52a. In contrast, the upper surface of the protrusion 53A shown in FIG. 10(b) is inclined downward toward the front (to the left in FIG. 10(b)) relative to the contact surface 52a. The upper surface of the protrusion 53B shown in FIG. 10(c) is inclined downward toward the rear (to the right in FIG. 10(c)) relative to the contact surface 52a. Furthermore, the upper surface of the protrusion 53C shown in FIG. 10(d) is formed in an arc shape that protrudes upward. When these protrusions 53A, 53B, and 53C contact the key rear stopper 51 from below, the upper surfaces of the protrusions 53A, 53B, and 53C contact the key rear stopper 51 gradually, unlike the protrusion 53, whose entire upper surface contacts the stopper 51 at once. This makes it possible to further reduce the impact noise compared to when the protrusion 53 abuts against the key rear stopper 51.

[0056] Furthermore, the detailed configurations of the rear end portion 52 of the key 2 and the rear key stopper 51 shown in the embodiment are merely examples and can be modified as appropriate within the scope of the present invention. [Explanation of symbols]

[0057] 1 Keyboard device 2 keys 2a white key 2b black key 4-key chassis 4a Chassis body 6 Key support mechanism 13 Rear of chassis 15 Cover plate (stopper support plate) 16a Upper key stop for white keys 17 Upper key stopper for black keys 21 White key upper limit position regulation section 26b Extension (black key upper limit position regulation part) 31 First Arm 32 Second Arm 51 Rear key stopper 52 Rear end of key 52a Contact surface 53 Convex part 53A Modification of convex part 53B Modification of convex part 53C Modification of convex part

Claims

1. a keyboard chassis having an upper limit stopper; A key extending a predetermined length in the front-rear direction and disposed on the top of the keyboard chassis; a key support mechanism that engages with the keyboard chassis and supports the key from below, and that, when a key is pressed, causes the pressed key to rotate about a virtual fulcrum that is located behind the rear end of the key; Equipped with The key has an upper limit position restricting portion provided at the bottom of the front end of the key, which restricts the upper limit position of the key by contacting the upper limit stopper from below when the key is released, a rear key stopper that is provided on the keyboard chassis and that the rear end of the key abuts from below before the upper limit position regulating portion abuts against the upper limit stopper when the key returns to its original position before it was pressed.

2. The rear end of the key is a contact surface that contacts the key rear stopper in a key-released state; a protrusion formed so as to protrude upward from the contact surface; 2. The keyboard device for a keyboard instrument according to claim 1, further comprising:

3. 3. The keyboard device for a keyboard instrument according to claim 2, wherein the upper surface of the convex portion is inclined with respect to the contact surface or is formed in an upwardly convex arc shape.

4. a stopper support plate attached to an upper portion of the rear end of the keyboard chassis; 4. A keyboard device for a keyboard instrument according to claim 1, wherein the key rear stopper is fixed to a front end of a lower surface of the stopper support plate.

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