JP3402170B2 - Keyboard device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a keyboard device capable of detecting a key pressing force, and more particularly to a keyboard device in which the influence of a key pressing force difference depending on a key pressing position is eliminated. . 2. Description of the Related Art Conventionally, there has been known a keyboard device which detects a key pressing force at the time of after touch (after key pressing) or the like and uses the detected key pressing force for musical tone control. For example, in the device disclosed in Japanese Patent Application Laid-Open No. 7-199946, a frame for supporting a key is rocked by a key-pressing operation so that a front portion thereof is displaced, and a displacement amount of the frame front portion is proportional to a key-pressing force. Based on this fact, the amount of displacement of the front part of the frame is detected by a strain gauge to grasp the key pressing force. In addition, in this device, the key is initially pressed (before releasing the key from the upper limit stopper), during key pressing (when the key is between the upper limit stopper and the lower limit stopper), and after the key is pressed (after the key contacts the lower limit stopper). The entire stroke sensing for detecting the key pressing force is performed in all of the steps, and various musical tone controls for controlling the tone, reverb, vibrato, etc. according to the key pressing force detected at each time of key pressing are performed. It is possible. Conventionally, a detected value of a key pressing force in a key-off state is stored and subtracted (canceled) from a key pressing force in a key-on state to obtain a true key pressing force in a key-on state. There is also known a keyboard device which is designed to determine the key (see Japanese Patent Application Laid-Open No. H8-6556). With this device, it is possible to control the musical tone faithfully according to the intention of the player. [0004] However, in a device that detects the key pressing force by detecting the amount of displacement of the frame (the same applies to the detection of pressure or the like at the front of the frame), the key is swung. Depending on the structure of the mechanism for moving the key and the structure of the mechanism for swinging the frame, it may not be possible to accurately detect the key pressing force during key pressing. FIG. 4 is a longitudinal sectional view showing an example of the configuration of a conventional keyboard device. In the figure, portions not related to the key pressing operation are omitted. In this keyboard device, a key depressing force of a key 101 is applied to a frame 103 supported by a lower case 102 of a keyboard instrument body.
Is detected from the amount of displacement. The frame 103 is configured by bonding members 103a and 103c to a member 103b. The frame 103 includes the ridge support member 1.
The support member 104 is supported by a spring 104 and an upper end (point Q ′) of the support member 104 so as to be vertically swingable. A photo reflector 106 for detecting the amount of displacement of the frame 103 is provided at the front of the lower case 102. Further, an upper limit stopper 107 and a lower limit stopper 108 for restricting the upper limit position and the lower limit position of the swing of the key 101 are attached to the frame 103. Further, a key spring 11 for constantly urging the key 101 upward is provided on the second member 103b of the frame 103.
0 is attached. [0007] The reaction force of the spring is generally proportional to the amount of expansion and contraction. However, the key spring 110 is set with a small spring constant and mounted with a large preload (in a sufficiently compressed state). Because it is normal, for convenience,
It can be considered that the key spring 110 generates a substantially constant reaction force F3 'when the key is pressed and when the key is not pressed. The key 101 has L on the front lower surface of both side walls.
A letter-shaped stopper piece 101a is provided vertically. Key 101
At the rear end portion 101b, a key-shaped locking portion 101c is provided.
1 and are formed integrally. The key 101 is
c is the rear end 103b 'of the member 103b of the frame 103.
(Point P ′), and is swingable up and down with the locking portion 101c as a fulcrum. The distance between the point P 'and the point Q' in the longitudinal direction of the key 101 is set to a predetermined value D '.
The distance between the point 10 and the spring 105 from the point P 'is set to predetermined values L3' and L4 ', respectively. Note that the normal key pressing position is a position at a distance L 'from the point P' (a position approximately 15 mm from the front end of the key 101). In this configuration, the key 101 is moved to the upper limit stopper 1 by the urging force of the key spring 110 before the key is pressed.
07, but when the key 101 is pressed with a certain force, the key is released from the lower limit stopper 108, and eventually the lower limit stopper 10
Contact 8 The photoreflector 106 is initially pressed (before the key is released from the upper limit stopper 107), and is being pressed (key 1).
01 is between the upper limit stopper 107 and the lower limit stopper 108) and after key depression (the key 101 is
) Can be detected in the entire stroke (after contact with the frame 103). Next, consider the balance of forces in a state where the key 101 stops during key depression after the key is released. FIG. 5 is a partial cross-sectional view showing the main force applied to the key 101 and the frame 103 which are stationary during key depression. As shown in FIG. 10A, the key 101 is pressed downward at a distance L ′ from the point P ′ by a key depression F ((g
f), the same applies hereinafter), and receives an upward force F3 'by the key spring 110 at a distance L3' from the point P ', and further a downward reaction force FP' from the frame 103 at the point P '. Is receiving. On the other hand, as shown in FIG. 1B, the frame 103 receives an upward reaction force FQ 'from the support member 104 at a point Q' and moves upward from the key 101 at a point P '. Of the key spring 110 at a distance L3 'from the point P', and further upward by a spring 105 at a distance L4 'from the point P'. The reaction force F4 'has been received. The reaction force F4 'of the spring 105 is substantially proportional to the displacement of the front portion of the frame 103. First, the following formulas 1 and 2 are established from the balance of the vertical force of the key 101 and the balance of the moment about the point P ′. F ′ + FP ′ = F3 ′ (2) F′L ′ = F3′L3 ′ Further, the balance of the vertical force of the frame 103 and the balance of the moment about the point P ′. Equations 3 and 4 below hold. F3 '= F4' + FP '+ FQ'F4'L4'=F3'L3' + FQ D From the above equations 1-4, the reaction force F4 'of the spring 105 is It is represented by Equation 5. F 4 ′ = (F′L ′ + F′D ′) / (L 4 ′ + D ′) Here, since the force F 3 ′ and the distance L 3 ′ are fixed values, The value F'L 'is constant. This value F'L 'is a downward (counterclockwise direction) moment with respect to a point P' required for the key 101 to stop during key depression. The reaction force F4 'is expressed by the following equation (6). F4 ′ = (Mk ′ + F′D ′) / (L4 ′ + D ′) Next, consider the case where the key-depression position is changed. For example, FIG.
As shown in FIG. 5 (or FIG. 5), the reaction force of the spring 105 when receiving the force F1 'at the position of the distance L1' from the point P 'is "F4' (L1 ')", and the distance L2 from the point P'. The reaction force of the spring 105 when the force F2 'is received at the position' is described as "F4 '(L2')". When the key 101 is stationary during key depression, the moment Mk ′ is constant, and M
k '= F'L' = F1 'L1' = F2 'L2' holds. Therefore, the difference between "F4 '(L1')" and "F4 '(L2')" is expressed by the following equation (7). ## EQU7 ## F4 '(L1')-F4 '(L2') = (F1'-F2
') D' / (L4 '+ D') Here, since F1 '<F2' and D = 0, eventually the following can be said. That is, when the key is stationary during key depression, the moment Fk required for releasing the key varies depending on the key depression position (the value of the distance L) because the moment Mk 'is constant. Then, the reaction force F4 'of the spring 105 differs depending on the magnitude of the force F' at the key pressing position, so that the front position of the frame 103 changes and the photo reflector 106
Is affected. Therefore, during key depression,
Even if the magnitude of the moment Mk 'is the same, if the key pressing position is different, a difference occurs in the detection value of the photo reflector 106. As described above, in the conventional keyboard device, the key pressing force during key depression differs depending on the key pressing position. For example, the key pressing force during key pressing is subtracted from the detection value after key pressing as a fixed value. If the key-pressing force after key-depression is obtained, the obtained key-pressing force after key-depression becomes inaccurate. Further, even when the key pressing force in the middle of key pressing is actually detected and subtracted from the detected value after key pressing, an accurate value can be obtained because there is a shift between the fulcrum position of the frame and the fulcrum position of the key. In addition, the configuration for detection and calculation is complicated. Further, when the key is pressed extremely at the rear end side, a displacement as if the key is pressed is generated in the frame, and an error is likely to occur in the detected value. Therefore, when the tone is controlled based on the key pressing force during key pressing, the key pressing force at the initial key pressing or after key pressing is accurately grasped by subtracting the key pressing force during key pressing or the like. in case you <br/> tone control, there is room for improvement in order to obtain a better detection value. SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to make it possible to accurately and easily grasp a key pressing force, and to more appropriately perform tone control and the like. It is an object of the present invention to provide a keyboard device capable of performing the following. According to a first aspect of the present invention, there is provided a keyboard apparatus comprising: a key to be depressed; and an upper limit for restricting an upper limit position of swing of the key. A stopper, a lower limit stopper that regulates a lower limit position of swinging of the key, and a key that supports the key so that it can swing vertically in a fulcrum at a rear end thereof and that is fixed to a keyboard instrument main body. And a frame that can swing vertically
The frame includes: urging means provided on the frame for urging the key upward; and detecting means for detecting a displacement amount of the frame, wherein the key is such that the key is provided to both the upper stopper and the lower stopper. The key is configured to swing by a force received from the key via the urging means and the rear end of the key at an uncontrolled key depression position, and the key of the frame fulcrum and the fulcrum of the rear end of the key is configured. wherein the the positions to match the in the longitudinal direction. With this configuration, when the key is pressed, the key swings between the upper limit stopper member and the lower limit stopper member around the fulcrum at the rear end of the key. The frame swings up and down about the frame fulcrum by the force received from the key via the urging means and the rear end of the key at the key depression position, and the amount of displacement due to the swing of the frame is detected. . When a key is pressed with a certain force, the key stops at a certain moment during the key pressing. Since the moment is constant when the key is stationary during key pressing, the key pressing force differs when the key pressing position in the longitudinal direction of the key differs. However, since the positions in the key longitudinal direction of the fulcrum of the frame and the fulcrum of the rear end of the key coincide with each other, the force received through the rear end of the key is the same as that of the frame fulcrum. Does not contribute to the moment given to That is, the moment received by the frame from the key is not affected by the difference in the key pressing position. Therefore, it is possible to make the amount of displacement of the frame in a state where the key is stationary during the key pressing substantially constant regardless of the key pressing position. Therefore, for example, the key depression force at the initial key depression and after the key depression can be accurately and easily grasped by subtracting the displacement amount of the frame during the key depression as a fixed value, and the tone control and the like can be more appropriately performed. Can be. Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view showing an example of the configuration of a keyboard device according to an embodiment of the present invention. In the figure, portions not related to the key pressing operation are omitted. In this keyboard device, the pressing force of each key 1 is detected from the displacement of the frame 3 supported by the lower case 2 of the keyboard instrument main body due to the swing. Key 1 indicates a white key, and a black key and other white keys are similarly configured. The present keyboard device is different from the above-described conventional keyboard device (FIGS. 4 and 5) in that the positions of the points P ′ and Q ′ in the key longitudinal direction are substantially the same, and other configurations are the same. . In FIG. 1, a frame 3 includes first and second frames.
And third members 3a, 3b and 3c.
b, the first member 3a and the third member 3c are bonded to each other. The frame 3 extends over the entire key width in the direction in which the keys 1 are arranged. At the rear of the lower case 2 (right side in the figure), a key 1
The ridge support member 4 is fixed in the arrangement direction.
A plurality of springs 5 are arranged in the front part 2 a of the lower case 2 in the direction in which the keys 1 are arranged. Each spring 5
The upper and lower ends are fixed to the frame 3 and the lower case 2. The frame 3 is supported by a support member 4 and a spring 5, and is vertically swingable about the upper end (point Q) (frame fulcrum) of the support member 4. A photo-reflector 6 (detection means) for detecting the amount of displacement of the frame 3 is provided at the front portion 2a of the lower case 2.
Is provided. The photo reflector 6 includes a light emitting / receiving part 6a and a reflecting plate 6b. Light emitting / receiving part 6
a is attached to the lower case 2 forward of the spring 5. The reflecting plate 6b is attached to the lower surface of the elastic bulging portion 6c so as to face the light emitting / receiving portion 6a. The light-emitting / light-receiving unit 6a is configured by a light-emitting element composed of a light-emitting diode and a light-receiving element composed of a phototransistor. The light receiving element generates a current according to the amount of light received. When the light emitting element emits light, the light emitting / receiving part 6a
The light receiving element receives a light amount corresponding to a distance between the light emitting element and the reflecting plate 6b, and determines a light emitting / receiving section 6 from a current value generated according to the light amount.
a can be detected from the reflection plate 6b. Thereby, the displacement amount of the frame 3 can be detected. The photo reflector 6 is provided on the third
The displacement of the front portion 3c ″ of the member 3c is always detected. That is, the key is initially pressed (before the key is released from the upper limit stopper 7), during key pressing (when the key 1 is between the upper limit stopper 7 and the lower limit stopper 8), and Detecting the amount of displacement of the frame 3 during the entire stroke after the key is pressed (after the key 1 contacts the lower limit stopper 8);
So-called full-stroke sensing is possible. In addition,
Sensing may be performed only after the key is pressed, or only at the beginning and after the key is pressed. An upper limit stopper 7 and a lower limit stopper 8 made of felt or the like are attached to the frame 3. The upper limit stopper 7 is attached to the lower surface of the front end 3b ″ of the second member 3b, and the lower limit stopper 8 is attached to the upper surface of the bottom 3c ′ of the third member 3c. To restrict the upper limit position and the lower limit position of the swing of the key 1. The front end 3b "of the second member 3b of the frame 3 is controlled.
Is provided with a key guide 9. Key guide 9
Restricts the movement of the key 1 in the key arrangement direction when the key 1 swings up and down. A key spring 10 (biasing means) for constantly biasing the key 1 upward is provided on the second member 3b of the frame 3.
Is attached. The key spring 10 is provided for each key 1, and upper and lower ends are fixed to the key 1 and the frame 3. Although the reaction force of the spring is generally proportional to the amount of expansion and contraction, the key spring 10 is set to a small spring constant, and is applied with a large preload (in a state where it is sufficiently compressed).
Since the spring 1 is usually attached, for convenience, it can be considered that the spring 1 generates a substantially constant reaction force F3 when the key is pressed and when the key is not pressed. A key switch 11 is further provided on the second member 3b of the frame 3. The key switch 11 is pressed by an actuator (not shown) of the key 1 when the key is pressed, and detects a key-on state. The key 1 has a concave end 1c at the rear end 1b.
Are formed integrally with the key 1. The lock portion 1c of the key 1 is locked to the rear end 3b 'of the second member 3b of the frame 3 (point P), and is swingable in the vertical direction with the lock portion 1c as a fulcrum. The key 1 has L-shaped stopper pieces 1a vertically provided on the lower surfaces of the side walls from the front. The stopper piece 1a comes into contact with the upper limit stopper 7 and the lower limit stopper 8, and the swing range of the key 1 is regulated. The rear end 3b 'of the second member 3b of the frame 3, which is the pivot point of the key 1, and the upper end of the support member 4, which is the pivot point of the frame 3, are substantially positioned in the longitudinal direction of the key 1. Match. That is, the point P in the longitudinal direction of the key 1
And the distance between the points Q is set to approximately 0 mm. With this setting, key 1 is pressed during key pressing for the reason described later with reference to FIG.
Can be made substantially constant, and the distance from the point P of the key spring 1 and the spring 5 can be set to predetermined values L3 and L4, respectively. Note that the normal key depression position is a position at a distance L (position about 15 mm from the front end of the key 1) forward from the point P. Although omitted in this embodiment, it is known. The key pressing force detected by the photoreflector 6 is converted into a musical tone control signal by a method of
Various various tone controls can be performed in accordance with the key pressing force detected at each time of key pressing. For example, the tone value can be controlled by the detected value at the initial stage of key depression, and the depth of reverb can be controlled by the detected value after the key depression. In the present embodiment, when the key pressing force at the initial key pressing or after the key pressing is obtained, the key pressing force during key pressing is subtracted from these actual detection values as a fixed value instead of a detected value, and the initial key pressing force and the key pressing force at the key pressing are calculated. A true key pressing force after key pressing can be obtained. FIG. 2 is a sectional view showing a state where a key is being depressed. Although the key 1 is in contact with the upper limit stopper 7 before the key is pressed (FIG. 1), the key 1 is pressed with a certain force (about 55 g at a normal key pressing position).
When pressed in f), the key is released from the upper limit stopper 7 (FIG. 2), and eventually comes into contact with the lower limit stopper 8 (not shown). Frame 3
Mainly receives force from the key 1 mainly through the locking portion 1c of the rear end portion 1b of the key 1 and the key spring 10, and also always receives force from the lower case 2 through the spring 5. In addition, the frame 3 also receives a force from the upper limit stopper 7 at the beginning of key pressing and also receives a force from the lower limit stopper 8 after key pressing, but receives a force from the stoppers 7 and 8 during key pressing. Absent. FIG. 3 is a partial cross-sectional view showing the main force applied to the key 1 and the frame 3 that are stationary during key depression. As shown in FIG. 3A, the key 1 receives a downward force F ((gf), the same applies hereinafter) due to key depression at a position L from the point P, and moves to a position L3 from the point P. The key spring 10 receives an upward force F3 and the point P receives a downward reaction force FP from the frame 3. On the other hand, the frame 3 receives an upward reaction force FQ from the support member 4 at a point Q and an upward reaction force from the key 1 at a point P, as shown in FIG. After receiving FP, point P
From the point P, a downward force F3 is applied by the key spring 1, and a distance L4 from the point P, an upward reaction force F4 is applied by the spring 5. In addition,
The reaction force F4 of the spring 5 is substantially proportional to the amount of displacement of the front portion 3c "of the frame 3. First, from the balance of the vertical force of the key 1 and the balance of the moment with respect to the point P, the following equation (8) is obtained. The following equation holds: F + FP = F3 FL = F3 L3 Also, the balance of the vertical force of the frame 3 and the point P
From the balance of the moment with respect to
1 holds. F3 = F4 + FP + FQ (11) F4L4 = F3L3 From the above equations 8 to 11, the reaction force F4 of the spring 5 is expressed by the following equation 12. F4 = FL / L4 Here, since the force F3 and the distance L3 are fixed values,
According to Equation 9, the value FL is constant. This value FL is a downward (counterclockwise in FIG. 2) moment about the point P required for the key 1 to come to a standstill during key depression. When this moment is described as moment Mk, the reaction force F4 of the spring 5
Is represented by Equation 13 below. F 4 = Mk / L 4 Equations 12 and 13 can be easily derived by substituting “0” for D ′ in Equations 5 and 6. As can be seen from the above equation (13), the reaction force F4 of the spring 5 is always constant when the key 1 is stationary during key depression. That is, since the moment Mk is constant, the force F required to release a key differs depending on the key-depression position (the value of the distance L). However, unlike a conventional keyboard device, the spring F depends on the magnitude of the force F at the key-depression position. No difference occurs in the reaction force F4 of No. 5. This means that the moment about the point Q received by the frame 3 is not affected by the difference in the key pressing position. Therefore, the front part 3c ″ of the frame 3
Is not affected by the key depression position. Therefore, the key pressing force during key pressing can be made constant regardless of the key pressing position. According to the present embodiment, the positions of the pivot point (point P) of the key 1 and the pivot point (point Q) of the frame 3 in the longitudinal direction of the key 1 are substantially matched. The amount of displacement of the frame 3 when the key 1 is stationary in the middle of the key can be made substantially constant. Therefore, by subtracting the key pressing force in the middle of key pressing as a fixed value (F4), the true key pressing force at the beginning of key pressing or after key pressing can be accurately and easily grasped. Further, even when the key at the rear end is extremely pressed, an error is hardly generated in the detection value. Therefore, the tone control is more appropriately performed based on the key pressing force during key pressing or by subtracting the key pressing force during key pressing to accurately grasp the key pressing force at the initial key pressing or after the key pressing. be able to. In this embodiment, the photoreflector 6 is used as the means for detecting the displacement of the frame 3.
The invention is not limited to this, and any device may be used as long as the displacement can be detected. For example, you may make it use the pressing force sensor comprised by the element whose resistance value changes with pressing force. Also,
When the frame 3 is configured as a flexible cantilever having the point Q as a fixed fulcrum, a strain gauge is provided slightly forward of the point Q of the frame 3 and the displacement of the frame 3 is detected by the gauge. It may be. Incidentally, the displacement detecting means such as the photo reflector 6 may be provided corresponding to each key. As described above, according to the first aspect of the present invention,
According to the keyboard device of the present invention, the key to be depressed, the upper limit stopper that regulates the upper limit position of the key swing, the lower limit stopper that regulates the lower limit position of the key swing, and thereby swingably supported vertically at the fulcrum end, a frame which is swingable in the vertical direction about the frame pivot fixed to the keyboard musical instrument body, said key provided in the frame above And a detecting means for detecting an amount of displacement of the frame, wherein the key is located at a key-pressed position where the key is not restricted by any of the upper limit stopper and the lower limit stopper. From the urging means and the force received via the rear end of the key, and the positions of the frame fulcrum and the fulcrum of the key rear end in the longitudinal direction of the key coincide with each other. /> The displacement of the frame in a state where the middle key key is stationary can be made substantially constant irrespective of the depressed position. Therefore, for example, the key depression force at the initial key depression and after the key depression can be accurately and easily grasped by subtracting the displacement amount of the frame during the key depression as a fixed value, and the tone control and the like can be more appropriately performed. Can be.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view showing an example of a configuration of a keyboard device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing a state where a key is being depressed. FIG. 3 is a partial cross-sectional view showing a main force applied to a key 1 and a frame 3 that are stationary during key pressing. FIG. 4 is a longitudinal sectional view showing an example of the configuration of a conventional keyboard device. FIG. 5 is a partial cross-sectional view showing a main force applied to a key 101 and a frame 103 which are stationary during key depression in a conventional keyboard device. [Description of Signs] 1 Key 1a Stopper piece 1b Rear end 1c Locking part 2 Lower case 2a Front 3 Frame 3a First member 3b Second member 3b "Front end 3c Third member 3c" Front 4 Support member Q Upper end of support member (frame fulcrum) 5 Spring 6 Photoreflector (detection means) 7 Upper limit stopper 8 Lower limit stopper 10 Key spring (biasing means)

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Claims (1)

(57) [Claim 1] A key to be depressed, an upper limit stopper for regulating an upper limit position of the key swing, and a lower limit stopper for regulating a lower limit position of the key swing. A frame supporting the key so that it can swing vertically in a fulcrum at a rear end thereof, and swinging vertically about a frame fulcrum fixed to the keyboard instrument body; and A biasing means for biasing the key upward; and a detecting means for detecting a displacement amount of the frame, wherein the frame is configured such that the key is not restricted by any of the upper limit stopper and the lower limit stopper. The key is positioned so as to swing by a force received from the key via the urging means and the rear end of the key from the key, and a longitudinal direction of the key at a fulcrum of the frame fulcrum and the rear end of the key. Match position in A keyboard device characterized by having