Patent Grant
10311847
The present application claims priority from Japanese Patent Application No. 2017-074267, which was filed on Apr. 4, 2017, the disclosure of which is herein incorporated by reference in its entirety.
The following disclosure relates to a keyboard apparatus.
Patent Document 1 (Japanese Patent Application Publication No. 2008-191650) discloses a keyboard apparatus in which a flexible thin plate is disposed horizontally as one example of a configuration for pivotal movement of a key. Deformation of the thin plate enables the key to pivot in an up and down direction. Patent Document 1 further discloses a configuration in which a thin plate disposed vertically is connected in series to the thin plate disposed horizontally, to allow movement of the key in a direction in which the keys are arranged.
Movement of the key with respect to its original position in the direction in which the keys are arranged is caused not only by playing but also by manufacturing error in the key and/or changes in the key with time. Even if this movement has occurred, the flexibility of the thin plate allows movement of the key in the direction in which the keys are arranged in the technique disclosed in Patent Document 1. However, the horizontal thin plate for pivotal movement of the key and the vertical thin plate for allowing movement of the key in the direction in which the keys are arranged have to be connected to each other in series. This requires a region for arrangement of these thin plates. If this region is small, the thin plates need to be small, resulting in a heavy load when the thin plates are bent. If larger thin plates are used in order to reduce this load, the keyboard apparatus needs to be made larger.
Accordingly, an aspect of the disclosure relates to a keyboard apparatus configured to reduce effects on the size of the keyboard apparatus and allow movement or deformation of a key in various directions.
In one aspect of the disclosure, a keyboard apparatus includes: a key; a frame; and a connecting portion configured to connect the key and the frame to each other, the connecting portion including a flexible member having a rod shape and having flexibility that enables the key to pivot with respect to the frame. The flexible member includes a portion that, in entirety of a range of pivotal movement of the key, maintains a state in which a length of a line extending along a neutral axis of the flexible member between two points located on the neutral axis is greater than a length of a straight line connecting the two points to each other.
In another aspect of the disclosure, a keyboard apparatus includes: a key; a frame; and a connecting portion configured to connect the key and the frame to each other, the connecting portion including a flexible member having a rod shape and having flexibility that enables the key to pivot with respect to the frame. The flexible member includes a portion that, in entirety of a range of pivotal movement of the key, maintains a state in which a neutral axis of the flexible member is bent.
In still another aspect of the disclosure, a keyboard apparatus includes: a key; a frame; and a connecting portion configured to connect the key and the frame to each other, the connecting portion including a flexible member having a rod shape and having flexibility that enables the key to pivot with respect to the frame. At least a portion of the flexible member includes: a first straight rod portion extending in a longitudinal direction of the key; a second straight rod portion extending in an up and down direction; and an intermediate rod portion having a rod shape, connecting the first straight rod portion and the second straight rod portion to each other, and extending in a direction different from each of the longitudinal direction and the up and down direction.
The objects, features, advantages, and technical and industrial significance of the present disclosure will be better understood by reading the following detailed description of the embodiments, when considered in connection with the accompanying drawings, in which:
Hereinafter, there will be described embodiments by reference to the drawings. It is to be understood that the following embodiments are described only by way of example, and the disclosure may be otherwise embodied with various modifications without departing from the scope and spirit of the disclosure. It is noted that the same or similar reference numerals (e.g., numbers with a character, such as A or B, appended thereto) may be used for components having the same or similar function in the following description and drawings, and an explanation of which is dispensed with. The ratio of dimensions in the drawings (e.g., the ratio between the components and the ratio in the lengthwise, widthwise, and height directions) may differ from the actual ratio, and portions of components may be omitted from the drawings for easier understanding purposes.
Configuration of Keyboard Apparatus
The keyboard apparatus 1 includes a keyboard assembly 10. The keyboard assembly 10 includes white keys 100w and black keys 100b arranged side by side. The number of the keys 100 is N. In the present embodiment, N is 88 but may be a number different from 88. A direction in which the keys 100 are arranged will be referred to as “scale direction”. The white key 100w and the black key 100b may be hereinafter collectively referred to “the key 100” in the case where there is no need of distinction between the white key 100w and the black key 100b. Also in the following explanation, “w” appended to the reference number indicates a configuration corresponding to the white key. Also, “b” appended to the reference number indicates a configuration corresponding to the black key.
A portion of the keyboard assembly 10 is located in a housing 90. In the case where the keyboard apparatus 1 is viewed from an upper side thereof, a portion of the keyboard assembly 10 which is covered with the housing 90 will be referred to as “non-visible portion NV”, and a portion of the keyboard assembly 10 which is exposed from the housing 90 and viewable by the user will be referred to as “visible portion PV”. That is, the visible portion PV is a portion of the key 100 which is operable by the user to play the keyboard apparatus 1. A portion of the key 100 which is exposed by the visible portion PV may be hereinafter referred to as “key main body portion”.
The housing 90 contains a sound source device 70 and a speaker 80. The sound source device 70 is configured to create a sound waveform signal in response to pressing of the key 100. The speaker 80 is configured to output the sound waveform signal created by the sound source device 70, to an outside space. It is noted that the keyboard apparatus 1 may include: a slider for controlling a sound volume; a switch for changing a tone color; and a display configured to display various kinds of information.
In the following description, up, down, left, right, front, and back (rear) directions (sides) respectively indicate directions (sides) in the case where the keyboard apparatus 1 is viewed from the player during playing. Thus, it is possible to express that the non-visible portion NV is located on a back side of the visible portion PV, for example. Also, directions and sides may be represented with reference to the key 100. For example, a key-front-end side (a key-front side) and a key-back-end side (a key-back side) may be used. In this case, the key-front-end side is a front side of the key 100 when viewed from the player. The key-back-end side is a back side of the key 100 when viewed from the player. According to this definition, it is possible to express that a portion of the black key 100b from a front end to a rear end of the key main body portion of the black key 100b is located on an upper side of the white key 100w.
The signal converter section 710 obtains the signals output from the sensors 300 (the sensors 300-1, 300-2, . . . , 300-88 corresponding to the respective 88 keys 100) and creates and outputs an operation signal in accordance with an operation state of each of the keys 100. In the present example, the operation signal is a MIDI signal. Thus, the signal converter section 710 outputs “Note-On” when a key is pressed. In this output, a key number indicating which one of the 88 keys 100 is operated, and a velocity corresponding to the speed of the key pressing are also output in association with “Note-On”. When the player has released the key 100, the signal converter section 710 outputs the key number and “Note-Off” in association with each other. A signal created in response to another operation, such as an operation on a pedal, may be output to the signal converter section 710 and reflected on the operation signal.
The sound source section 730 creates the sound waveform signal based on the operation signal output from the signal converter section 710. The output section 750 outputs the sound waveform signal created by the sound source section 730. This sound waveform signal is output to the speaker 80 or a sound-waveform-signal output terminal, for example.
Configuration of Keyboard Assembly
There will be next described a configuration of the keyboard assembly 10 with reference to
Each of the turnable portions 185 includes a rod-like flexible member 1850, a key-side supporter 1851, and a frame-side supporter 1852. The key-side supporter 1851 supports one end of the rod-like flexible member 1850. In the present embodiment, the key-side supporter 1851 is connected to a component (the first supporter 183 in the present embodiment) having a fixed positional relationship with the key 100. The key-side supporter 1851 includes a component extending downward and supports one end (a back end) of the rod-like flexible member 1850. The frame-side supporter 1852 supports the other end (a front end) of the rod-like flexible member 1850. The detailed configuration of the turnable portions 185 will be described below.
The rod-like flexible member 1850 is formed of a flexible material and shaped like a bent rod. That is, a neutral axis of the rod-like flexible member 1850 at least has a bent portion in a state in which no power is applied to the neutral axis. In the present embodiment, the neutral axis of the rod-like flexible member 1850 at least has a bent portion at the entire movable area of the key 100 (the entire key pressing area). The flexibility enables the rod-like flexible member 1850 to be bent and twisted in various directions. The detailed configuration of the rod-like flexible member 1850 will be described below. The key-side supporter 1851 and the frame-side supporter 1852 are formed of a material that is the same in properties as that of the rod-like flexible member 1850, while the key-side supporter 1851 and the frame-side supporter 1852 are stiffer than the rod-like flexible member 1850. A positional relationship between the key-side supporter 1851 and the frame-side supporter 1852 changes with deformation of the rod-like flexible member 1850. When the rod-like flexible member 1850 is bent, the key-side supporter 1851 moves upward with respect to the frame-side supporter 1852, allowing the key 100 to pivot with respect to the frame 500 (see
Each of the turnable portions 185 is supported by a corresponding one of the first supporters 183 and a corresponding one of second supporters 585 of the frame 500. The first supporter 183 and the key-side supporter 1851 are connected to each other attachably and detachably. The second supporter 585 and the frame-side supporter 1852 are connected to each other attachably and detachably. The attachable and detachable configuration facilitates manufacturing (such as a design of a metal mold, assembly, and repair) and improves a touch feeling and the strength due to combination of the materials. It is noted that the turnable portion 185 may be integral with at least one of the first supporter 183 and the second supporter 585 or bonded so as not to be attached or detached. It is further noted that the following description will be provided for each of the keys 100 for simplicity unless otherwise required.
The plate-like flexible member 181 and the first supporter 183 are molded integrally with the key 100 and formed of a material having the same properties as those of the material of the key 100. The frame 500 is also formed of a material having the same properties as those of the material of the plate-like flexible member 181 but may be formed of a material having properties different from those of the material of the plate-like flexible member 181. The turnable portion 185 (the rod-like flexible member 1850) is formed of a material having properties different from those of the material of the plate-like flexible member 181 but may be formed of a material having the same properties as those of the material of the plate-like flexible member 181. In the present embodiment, the plate-like flexible member 181 is harder than the rod-like flexible member 1850.
The key 100 includes a front-end key guide 151 and a side-surface key guide 153. The front-end key guide 151 is in slidable contact with a front-end frame guide 511 of the frame 500 in a state in which the front-end key guide 151 covers the front-end frame guide 511. The front-end key guide 151 is in contact with the front-end frame guide 511 at opposite side portions of upper and lower portions of the front-end key guide 151 in the scale direction. The upper portion of the front-end key guide 151 corresponds to an upper-portion key guide 151u, and the lower portion of the front-end key guide 151 corresponds to a lower-portion key guide 151d (see
The hammer assembly 200 is disposed at a space under the key 100 and attached so as to be pivotable with respect to the frame 500. A bearing 220 of the hammer assembly 200 and a pivot shaft 520 of the frame 500 are in slidable contact with each other at at least three points. A front end portion 210 of the hammer assembly 200 is located in an inner space of a hammer supporter 120 and in contact with the hammer supporter 120 slidably substantially in the front and rear direction. This sliding portion of the front end portion 210, i.e., portions of the front end portion 210 and the hammer supporter 120 which are in contact with each other, are located under the key 100 at the visible portion PV (located in front of a rear end of the key main body portion).
The hammer assembly 200 is provided with a metal weight 230 disposed on a back side of the pivot shaft 520. In a normal state (i.e., a state in which the key 100 is not pressed), the weight 230 is placed on a lower stopper 410, and the front end portion 210 of the hammer assembly 200 pushes the key 100 upward. When the key 100 is pressed, the weight 230 moves upward and comes into contact with an upper stopper 430. The hammer assembly 200 adds a weight to key pressing by the weight 230. The lower stopper 410 and the upper stopper 430 are formed of a cushioning material such as a nonwoven fabric and a resilient material, for example.
The sensor 300 is attached to the frame 500 under the hammer supporter 120 and the front end portion 210. When the key 100 is pressed, a lower surface of the front end portion 210 deforms the sensor 300, causing the sensor 300 to output detection signals. As described above, the sensors 300 are provided for the respective keys 100.
As illustrated in
Though
Supports 590 are connected to the housing 90 to position the frame 500 with respect to the housing 90. Each of the supports 590 is provided between corresponding adjacent two of the white keys 100w which are adjacent to each other in the non-visible portion NV. That is, each of the supports 590 is provided between the white key 100w (E) and the white key 100w (F) or between the white key 100w (B) and the white key 100w (C).
Configuration of White Key
First, there will be defined directions used in the following description (the scale direction S, the rolling direction R, the yawing direction Y, the up and down direction V, and the front and rear direction F). As described above, the scale direction S corresponds to the direction in which the keys 100 are arranged (i.e., the right and left direction when the keyboard apparatus 1 is viewed from the player). The rolling direction R corresponds to a direction rolling about the direction in which the key 100 extends (i.e., the back direction when the keyboard apparatus 1 is viewed from the player). The yawing direction Y is a direction bent in the right and left direction when the key 100 is viewed from above. Though there is no large difference between the scale direction S and the yawing direction Y, movement of the key 100 in the scale direction S of the key 100 means a translation of the key 100, and movement of the key 100 in the yawing direction Y means bending or warping of the key 100 in the scale direction S. The up and down direction V corresponds to the up and down direction when the keyboard apparatus 1 is viewed from the player. The up and down direction V serves as an axis for bending of the yawing direction Y. The front and rear direction F corresponds to the direction in which the key 100 extends (i.e., the back direction when the keyboard apparatus 1 is viewed from the player). The front and rear direction F also serves an axis for the roll of the rolling direction R. It is noted that the front and rear direction F is a direction (included in the horizontal plane) orthogonal to both of the up and down direction V and the scale direction S, and strictly the front and rear direction F is different from but substantially coincides with the direction in which the key 100 located at its rest position extends.
The key 100 is provided with the front-end key guide 151 and the side-surface key guide 153. As described above, the upper and lower portions of the front-end key guide 151 contact the front-end frame guide 511 of the frame 500 (see
The plate-like flexible member 181 is a plate-like member having flexibility in the scale direction S. The plate-like flexible member 181 is disposed such that a direction of a normal N to a plate surface of the plate-like flexible member 181 is directed toward the scale direction S. With this configuration, the plate-like flexible member 181 is deformable in the rolling direction R and the yawing direction Y by bending or twisting. That is, the flexibility of the plate-like flexible member 181 gives the plate-like flexible member 181 freedom in the rolling direction R and the yawing direction Y of the key 100. Combination of deformation in the yawing direction Y and deformation in the rolling direction R gives the plate-like flexible member 181 freedom in the scale direction S. The plate-like flexible member 181 is hardly deformed in the up and down direction. It is noted that the direction of the normal N may not completely coincide with the scale direction S and only has to have a component of the scale direction S. In the case where the direction of the normal N does not completely coincide with the scale direction S, the angle between the direction of the normal N and the scale direction S is preferably smaller.
The rod-like flexible member 1850 is deformable in the rolling direction R and the yawing direction Y by bending or twisting. That is, the flexibility of the rod-like flexible member 1850 gives the rod-like flexible member 1850 freedom in the rolling direction R and the yawing direction Y of the key 100. Combination of deformation in the yawing direction Y and deformation in the rolling direction R gives the rod-like flexible member 1850 freedom in the scale direction S. The rod-like flexible member 1850 is also deformable in the front and rear direction F and in the up and down direction V. It is noted that a twistable amount of the rod-like flexible member 1850 is greater than that of the plate-like flexible member 181 due to the property of the shape of the rod-like flexible member 1850.
Thus, the connecting portion 180 is not only configured to cause pivotal movement of the key 100 with respect to the frame 500 in a pitch direction but also deformable in the rolling direction R and the yawing direction Y. That is, the connecting portion 180 has freedom in the rolling direction R and the yawing direction Y of the key 100. As described above, combination of the deformation of the yawing direction Y and the deformation in the rolling direction R gives the connecting portion 180 freedom in the scale direction S.
As described above, the key 100 may be deformed in directions including the yawing direction Y and the rolling direction R due to manufacturing error in the key 100 and changes in the key 100 with time. Between the front-end key guide 151 and the side-surface key guide 153, in this deformation, effects caused by the deformation of the key 100 are not visibly recognized as possible at the visible portion PV by the restriction of the front-end key guide 151 and the side-surface key guide 153. Since the effects caused by the deformation are reduced at the visible portion PV, the non-visible portion NV is greatly affected by the deformation. The longer the key 100, the greater the effects are.
As a first example, it is assumed that the key 100 is gradually twisted (in other words, the key 100 is gradually deformed in the rolling direction R). In this case, the upper-portion key guide 151u and the lower-portion key guide 151d restrict movement of the key 100 such that the rolling direction R of a front end portion of the key 100 becomes the vertical direction. Thus, a back portion of the key 100 is more greatly affected by deformation of the key 100 in the rolling direction R than a front portion of the key 100. As a second example, it is assumed that the key 100 is gradually bent in the scale direction S (in other words, the key 100 is gradually deformed in the yawing direction Y). In this case, the front-end key guide 151 and the side-surface key guide 153 restrict the position of the key 100 in the scale direction S at the visible portion PV. Thus, the back portion of the key 100 is more greatly affected by deformation of the key 100 in the yawing direction Y than the front portion of the key 100.
In any of the cases, the pivot center of the key 100 and the position of the frame 500 deviate from each other due to the effects caused by deformation of the key 100. That is, a positional relationship between the second supporter 585 and the connecting portion 180 (the first supporter 183) connected to the key 100 changes.
In the key 100 in the first embodiment, the plate-like flexible member 181 and the rod-like flexible member 1850 are deformable due to their flexibility. Thus, effects caused by deviation between the key 100 and the second supporter 585 can be reduced by deformation of the connecting portion 180 (the plate-like flexible member 181 and the rod-like flexible member 1850). In this operation, the rod-like flexible member 1850 has not only a function as a component for causing pivotal movement of the key 100 in the pitch direction but also a function as a component for absorbing effects caused by deformation of the key 100. In this operation, in the case where the side-surface key guide 153 and the side-surface frame guide 513 restrict movement of the key 100 in the front and rear direction, it is possible to reduce effects caused by deformation of the rod-like flexible member 1850 in the front and rear direction F, thereby stabilizing pivotal movement of the key 100 in the pitch direction.
Also, as described above, since the effects caused by the deformation of the key 100 are not visibly recognized as possible at the visible portion PV, positional accuracy in the scale direction S is high. Thus, the front end portion 210 of the hammer assembly 200 which is detected by the sensor 300 and the hammer supporter 120 of the key 100 which is connected to the front end portion 210 are preferably provided under the key 100 at the visible portion PV (in front of the rear end of the key main body portion).
Configuration of Turnable Portion
There will be next described the configuration of the turnable portion 185. In the present embodiment, the turnable portion 185 is attachable to and detachable from the first supporter 183 and the second supporter 585.
The first supporter 183 has a first space 183S1 and a second space 183S2 formed through the first supporter 183 in the up and down direction. A third space 183S3 is connected to a rear end of the second space 183S2. An engaging rod 1855 is disposed in the first space 183S1, and a support rod 1853 is disposed in the second space 183S2. The support rod 1853 is inserted in the second space 183S2 from a lower side thereof. The engaging rod 1855 is inserted in the first space 183S1 from a lower side thereof. A top portion of the engaging rod 1855 has an engaging portion 18551. The engaging portion 18551 protrudes upward from the first space 183S1. The engaging portion 18551 is caught by an upper surface of the first supporter 183, whereby the engaging rod 1855 is not pulled out from the first supporter 183 by pivotal movement of the key 100. It is noted that the engaging rod 1855 has flexibility. The engaging rod 1855 may be disposed in the first space 183S1 in a state in which the engaging rod 1855 is bent toward the support rod 1853 (backward). When the engaging rod 1855 is deformed toward the support rod 1853 by pressing the engaging portion 18551 toward the support rod 1853, the engagement of the engaging rod 1855 with the first supporter 183 is canceled.
The support rod 1853 and the engaging rod 1855 are connected to the key-side supporter 1851. The key-side supporter 1851 includes: a plate-like member disposed along a lower surface of the first supporter 183; and a component extending downward from the plate-like member. In the present embodiment, a reinforcing plate 1859 is disposed to prevent changes in positional relationship between the support rod 1853 and the key-side supporter 1851. The reinforcing plate 1859 is a plate-like member connected to the key-side supporter 1851, and a portion of the reinforcing plate 1859 is disposed in the third space 183S3.
The second supporter 585 has a first space 585S1 and a second space 585S2 formed through the second supporter 585 in the up and down direction. An engaging rod 1856 is disposed in the first space 585S1, and a support rod 1854 is disposed in the second space 585S2. The support rod 1854 is inserted in the second space 585S2 from an upper side thereof. The engaging rod 1856 is inserted in the first space 585S1 from an upper side thereof. A top portion of the engaging rod 1856 has an engaging portion 18561. The engaging portion 18561 protrudes downward from the first space 585S1. The engaging portion 18561 is caught by a lower surface of the second supporter 585, whereby the engaging rod 1856 is not pulled out from the second supporter 585 by pivotal movement of the key 100. It is noted that the engaging rod 1856 has flexibility. The engaging rod 1856 may be disposed in the first space 585S1 in a state in which the engaging rod 1856 is bent toward the support rod 1854 (backward). When the engaging rod 1856 is deformed toward the support rod 1854 by pressing the engaging portion 18561 toward the support rod 1854, the engagement of the engaging rod 1856 with the second supporter 585 is canceled.
The support rod 1854 and the engaging rod 1856 are connected to a lower surface of the frame-side supporter 1852. The frame-side supporter 1852 is a plate-like member disposed along an upper surface of the second supporter 585. The rod-like flexible member 1850 is connected to an upper surface of the frame-side supporter 1852.
Method of Attaching and Detaching Turnable Portion
There will be next described a method of detaching the turnable portion 185 from the first supporter 183 and the second supporter 585.
When the player attaches the turnable portion 185 to the first supporter 183, the first supporter 183 is moved downward in a state in which the support rod 1853 is inserted in the second space 183S2 from a lower side thereof, and the engaging portion 18551 is inserted in the first space 183S1 from a lower side thereof. Since a distal end of the engaging portion 18551 has an inclined surface, the engaging portion 18551 and the engaging rod 1855 are inserted into the first space 183S1 in a state in which the engaging rod 1855 is bent toward the support rod 1853. When the first supporter 183 is further moved downward, the engaging portion 18551 protrudes upward from the first space 183S1, the shape of the engaging rod 1855 is returned its original shape, and the engaging portion 18551 is engaged with the upper surface of the first supporter 183.
There will be next described a method of detaching the turnable portion 185 from the second supporter 585. This method is principally the same as the method of detaching the turnable portion 185 from the first supporter 183. When a force is applied to the engaging portion 18561 toward the support rod 1854, the flexible engaging rod 1856 is bent to move the engaging portion 18561 to a position at which the engaging portion 18561 can be pushed into the first space 585S1. When the second supporter 585 is moved downward with respect to the turnable portion 185, the engaging portion 18561 moves in the first space 585S1. When the second supporter 585 is further moved downward (the turnable portion 185 is moved upward), the second supporter 585 and the turnable portion 185 are separated from each other, and the shape of the engaging rod 1856 is returned into its original shape.
When the player attaches the turnable portion 185 to the second supporter 585, the second supporter 585 is moved upward (the turnable portion 185 is moved downward) in a state in which the support rod 1854 is inserted in the second space 585S2 from an upper side thereof, and the engaging portion 18561 is inserted in the first space 585S1 from an upper side thereof. Since a distal end of the engaging portion 18561 has an inclined surface, the engaging portion 18561 and the engaging rod 1856 are inserted into the first space 585S1 in a state in which the engaging rod 1856 is bent toward the support rod 1854. When the second supporter 585 is further moved upward (the turnable portion 185 is further moved downward), the engaging portion 18561 protrudes downward from the first space 585S1, the shape of the engaging rod 1856 is returned to its original shape, and the engaging portion 18561 is engaged with the lower surface of the second supporter 585.
It is noted that
Configuration of Rod-Like Flexible Member
There will be next described the configuration of the rod-like flexible member 1850 in the turnable portion 185 in detail. As in the description provided above, the following description is provided using figures in which the rod-like flexible member 1850 is viewed in the scale direction.
The cross-sectional shape of the rod-like flexible member 1850 (i.e., the shape of the cross section of the rod-like flexible member 1850 which is perpendicular to the extending direction (the neutral axis NA) of the rod-like flexible member 1850) is a round shape in the present embodiment. The cross-sectional shape of the rod-like flexible member 1850 is not limited to the round shape and may be any of (i) a shape defined only by a curve or curves, (ii) a shape (e.g., a semicircular shape) defined by combination of a curve or curves and a straight line or straight lines, and (iii) a shape (e.g., a rectangular shape) defined only by straight lines, for example. The rod-like flexible member 1850 may be shaped like a tube having a space therein. That is, the rod-like flexible member 1850 may have any cross-sectional shape as long as the rod-like flexible member 1850 can be bent in a direction perpendicular to the neutral axis NA and twisted about the neutral axis NA. In the present embodiment, the thickness of the rod-like flexible member 1850 (which corresponds to a distance between the neutral axis NA and a surface of the rod-like flexible member 1850) is the same at any position on the neutral axis NA. However, the thickness of the rod-like flexible member 1850 may change depending upon positions on the neutral axis NA. In the case where an outer edge of the cross-sectional shape of the rod-like flexible member 1850 is formed into a rectangular shape, a ratio between the lengths of two sides of the rectangular shape which are orthogonal to each other may be greater than or equal to three quarters or less than or equal to four thirds but is not limited to this range.
In a state in which the key 100 is not pressed (that is, the key 100 is located at the rest position), the extending direction ED1 at the position P1 substantially coincides with the longitudinal direction of the key 100 (i.e., the front and rear direction F), and even in the case where the position P1 is changed in position in the longitudinal direction in the first straight rod portion 18501, the angle of the extending direction ED1 with respect to the longitudinal direction of the key 100 does not change. Also, the extending direction ED2 at the position P2 substantially coincides with a direction (the up and down direction V) perpendicular to the longitudinal direction of the key 100, and even in the case where the position P2 in the second straight rod portion 18502 is changed in position in the direction perpendicular to the longitudinal direction of the key 100, the angle of the extending direction ED2 with respect to the longitudinal direction of the key 100 does not change. In contrast, since the curved rod portion 18503 is curved, the extending direction ED3 at the position P3 changes such that the angle of the extending direction ED3 with respect to the longitudinal direction of the key 100 gradually increases with change in the position P3 from the first straight rod portion 18501 toward the second straight rod portion 18502. In the present embodiment, since the neutral axis NA is disposed along a plane on which the key 100 pivots, the straight line SL is disposed along the plane on which the key 100 pivots, and the extending direction changes along this plane. Thus, in the case where the rod-like flexible member 1850 is viewed from an upper side thereof, the rod-like flexible member 1850 has a rod shape extending in a straight line extending along the longitudinal direction of the key 100.
It is noted that, in at least a portion of the area of the pivotal movement of the key 100, the angle between the extending direction ED1 and the longitudinal direction of the key 100 is not limited to zero degree and may be greater than or equal to zero degree or less than 45 degrees, and the angle between the extending direction ED2 and the longitudinal direction of the key 100 is not limited to 90 degrees and may be greater than or equal to 45 degrees or less than 90 degrees. A change in the extending direction of the rod-like flexible member 1850 (e.g., a change in angle when the extending direction is changed from the extending direction ED1 to the extending direction ED2, which angle corresponds to an angle FA in
As described above, the connecting portion 180 is deformable in the rolling direction R and the yawing direction Y. Since the rod-like flexible member 1850 has the shape illustrated in
A heavy shearing load is imposed on the rod-like flexible member 1850 in response to particular key pressing such as depression of a back portion of the key 100 (near the connecting portion 180). The shorter a distance between the key-side end portion KE and the frame-side end portion FE of the rod-like flexible member 1850 in a straight line, the rod-like flexible member 1850 is more advantageous in configuration against a bending stress due to such a shearing load. The greater the length between the key-side end portion KE and the frame-side end portion FE along the rod-like flexible member 1850, e.g., the length of the neutral axis NA between the key-side end portion KE and the frame-side end portion FE, the flexible member 1850 is more advantageous for reducing a bending reaction force produced by the flexible member 1850. In the first embodiment, the distance along the neutral axis NA between the predetermined two points (i.e., the positions P1, P2 in the above-described example) in the rod-like flexible member 1850 is greater than the distance between the predetermined two points in a straight line, making it possible to support the key 100 pivotably with a small reaction force and improve the durability.
Operations of Keyboard Assembly
When the key 100 is released, the weight 230 moves downward, the hammer assembly 200 pivots, and the key 100 pivots upward. When the weight 230 comes into contact with the lower stopper 410, the pivotal movement of the hammer assembly 200 is stopped, and the key 100 is returned to the rest position.
As described above, the keyboard apparatus 1 according to the first embodiment connects the key 100 at the connecting portion 180 such that the key 100 pivotable in response to key pressing and key releasing. In the keyboard apparatus 1, movement of the key 100 is restricted by the front-end key guide 151 and the side-surface key guide 153, and the connecting portion 180 is deformable, thereby reducing effects on the visible portion PV due to manufacturing error in the key 100 and deformation of the key 100 due to changes with time.
Use of the rod-like flexible member 1850 enables one component to allow movement or deformation of the key 100 in various directions, that is, the rod-like flexible member 1850 is movable and deformable in various directions. In other words, the keyboard apparatus 1 according to the first embodiment uses the rod-like component having flexibility having a bent portion. This configuration reduces effects on the size of the keyboard apparatus 1 when compared with a conventional technique in which regions are defined for respective directions in which movement or deformation of the key is allowed, and a plurality of components are combined with each other. Also, as described above, it is possible to improve the durability of the rod-like flexible member 1850.
While the rod-like flexible member 1850 has the positional relationship in which the key-side end portion KE is located on an upper and back side of the frame-side end portion FE in the first embodiment, the positions of the key-side end portion KE and the frame-side end portion FE are not limited to this configuration. Also, while the rod-like flexible member 1850 has the direction relationship in which the neutral axis NA at the key-side end portion KE extends in the front and rear direction F, and the neutral axis NA at the frame-side end portion FE extends in the up and down direction V, the directions of the neutral axis NA are not limited to this configuration. In the second embodiment, the positional relationship and the direction relationship between the key-side end portion KE and the frame-side end portion FE are changed in the rod-like flexible member 1850 including the first straight rod portion 18501, the second straight rod portion 18502, and the curved rod portion 18503.
While the key 100 is located above the frame 500 in the above-described examples, the frame 500 may also be disposed above the key 100. In this case, each of the rod-like flexible members 1850A, 1850B, 1850C, 1850D only needs to be configured such that the portion of the rod-like flexible member which includes the key-side end portion KE and the portion of the rod-like flexible member which includes the frame-side end portion FE are replaced with each other.
In the first embodiment, the rod-like flexible member 1850 is configured such that the two straight rod portions (i.e., the first straight rod portion 18501 and the second straight rod portion 18502) are connected to each other by the one curved rod portion 18503, and the rod-like flexible member 1850 has the rod shape bent only in one direction. In the third embodiment, a rod-like flexible member has a rod shape bent in a plurality of directions.
While each of the rod-like flexible members 1850E, 1850F includes the two curved rod portions in these examples, the rod-like flexible member may includes three or more curved rod portions. Also, the rod-like flexible member may be constituted only by curved rod portions without using any straight rod portion.
In the first embodiment, the rod-like flexible member 1850 is configured such that the two straight rod portions (i.e., the first straight rod portion 18501 and the second straight rod portion 18502) are connected to each other by the one curved rod portion 18503, and the neutral axis NA has a curve, whereby the rod-like flexible member 1850 has a bent rod shape. In a fourth embodiment, there will be described a rod-like flexible member 1850G including two straight rod portions directly connected to each other to form a bent rod shape.
In the first embodiment, the area of the shape of the rod-like flexible member 1850 in cross section perpendicular to the neutral axis NA (i.e., the cross-sectional area of the rod-like flexible member 1850) is constant regardless of positions on the neutral axis NA. In the fifth embodiment, there will be described a rod-like flexible member 1850H in which this cross-sectional area varies with positions on the neutral axis NA.
Bending properties, the durability, and so on of the rod-like flexible member can be set variously, depending upon which position a portion having a large cross-sectional area is located at. It is noted that the cross-sectional area may vary in one straight rod portion, with positions on the neutral axis NA. The rod-like flexible member may be configured such that the cross-sectional area varies in the curved rod portion with positions on the neutral axis NA, and a plurality of straight rod portions have the same cross-sectional area.
In the first embodiment, the extending direction of the curved rod portion 18503 is changed by 90 degrees. In a sixth embodiment, there will be described a rod-like flexible member 1850J including a curved rod portion that changes the extending direction by an angle greater than or equal to 90 degrees.
In the first embodiment, the neutral axis NA is disposed along the plane on which the key 100 pivots. In the seventh embodiment, the neutral axis NA may be disposed along a plane including the direction in which the keys 100 are arranged (i.e., the scale direction S) and the longitudinal direction of the key 100 (i.e., the front and rear direction F), in the state in which the key 100 is not pressed (that is, the key 100 is located at the rest position).
As illustrated in
Modifications
While the embodiments have been described above, it is to be understood that the disclosure is not limited to the details of the illustrated embodiments, but may be embodied with various changes and modifications, which may occur to those skilled in the art, without departing from the spirit and scope of the disclosure. The above-described embodiments may be combined or replaced with each other. Also, the following modifications may be made to each of the above-described embodiments.
(1) In the first embodiment, the neutral axis NA and the straight line SL are disposed along the plane on which the key 100 pivots. In the seventh embodiment, the neutral axis NA and the straight line SL are disposed along a plane including the direction in which the keys 100 are arranged (i.e., the scale direction) and the longitudinal direction of the key 100 in the state in which the key 100 is not pressed (that is, the key 100 is located at the rest position). The neutral axis NA of the rod-like flexible member may not satisfy these conditions. For example, the rod-like flexible member may be configured such that the straight line SL includes: a component along the plane on which the key 100 pivots (or a component in the pivotal direction); and a component of the scale direction in the state in which the key 100 is not pressed (that is, the key 100 is located at the rest position). For example, the rod-like flexible member may be shaped like a coil spring. In the above-described embodiments, the straight line SL has any of these components, by way of example.
(2) While the rod-like flexible member has various shapes in the above-described embodiments, the rod-like flexible members may not have the same shape for all the keys 100. For example, the rod-like flexible member connected to the white key 100w and the rod-like flexible member connected to the black key 100b may have different shapes. The rod-like flexible member connected to the high-pitch key 100 and the rod-like flexible member connected to the low-pitch key 100 may be different from each other in shape.
(3) The neutral axis NA at each of the key-side end portion KE and the frame-side end portion FE may not extend in the front and rear direction F or the up and down direction V and may be inclined with respect to each of the front and rear direction F and the up and down direction V.
(4) The pivot center of the black key 100b and the pivot center of the white key 100w may be located at the same position in the back direction. In this case, the sizes of the connecting portions 180b, 180w in the scale direction S need to be determined such that the connecting portions 180b, 180w can be disposed adjacent to each other.
(5) The connecting portion 180 includes the plate-like flexible member 181 and the rod-like flexible member 1850 in the above-described embodiments but may not include the plate-like flexible member 181.
(6) The key 100 is formed of resin, but a wood member may be stuck to a side surface of the key 100 at the visible portion PV (at the key main body portion) to enhance an appearance. In this case, the side-surface key guide 153 is preferably provided at a portion of the key 100 which is different from the portion of the key 100 to which the wood member is stuck, that is, the side-surface key guide 153 is preferably provided at a portion of the key 100 at which the resin portion is exposed. That is, the side-surface frame guide 513 contacts the resin portion of the key 100.
(7) The movement of the key 100 in the front and rear direction is restricted by the side-surface key guide 153 but may be restricted by another guide.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2017-074267 | Apr 2017 | JP | national |
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| Number | Date | Country | |
|---|---|---|---|
| 20180286369 A1 | Oct 2018 | US |
