JP2004234019A - Electronic keyboard instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic keyboard instrument whose acoustic characteristics are improved at both the audience side and the player side in a simple constitution. <P>SOLUTION: A keyboard 3 is provided close to the front of the casing 1 and the sounds from the front of speakers 12a and 12b are radiated backward through the main tone holes 10a and 10b provided on the back of the casing 1. On the top surface of the casing 1, sub-tone holes 11a and 11b are bored at specified positions corresponding to the sides of the speakers and sound components from the speaker sides are radiated to above the musical instrument to compensate the high tone region components, so the high tone region never falls even at the player side. Openings of the subtone holes are within the ranges of the depth length of the speakers. Or the area of the subtone holes is smaller than that of the main tone holes. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to an electronic keyboard instrument, and more particularly to an improvement in a sound emission structure from a speaker.

  In an electronic keyboard musical instrument having a flat board-like housing shape as a whole, a conventional speaker arrangement structure is to provide a sound emission opening on the upper surface of the housing and arrange a speaker with the front face facing this opening. And a type in which a sound emission opening is provided on the back of the housing, and a speaker is disposed with the front facing the opening. In the former case, the sound is emitted above the instrument, so that, for example, when an audience is assumed to be located at a certain distance behind the instrument, the sound to the audience side is not sufficient. On the other hand, when the speakers are arranged toward the back of the instrument as in the latter case, the sound flow to the audience side is improved, but the sound flow to the player facing the keyboard in front of the instrument is improved. not enough. For this reason, an improper touch of the key touch response caused by poor feedback of the sound to the performer may cause a mistouch, which may result in a decrease in performance expression.

On the other hand, in Patent Literature 1 below, speakers are arranged diagonally upward at predetermined positions near the back of the housing of the musical instrument, thereby improving the acoustic characteristics on both the audience side and the performer side. Things are shown. However, when the speaker is directed obliquely upward in this way, there are limitations on the acoustic characteristics in front (closer to the player) and rearward (closer to the audience), and this is insufficient. Further, it is not easy in manufacturing and assembling, and the cost is increased.
SUMMARY OF THE INVENTION In general, sound propagation tends to be diffracted in a low frequency range, so that it is relatively easy to hear at any position regardless of the speaker arrangement (directional direction of the front of the speaker). On the other hand, the treble range is affected by the arrangement of the speakers, and becomes difficult to hear in a position where the sound path is not sufficient. Therefore, in the above-described prior art, there is a problem of acoustic characteristics particularly in a high-frequency range.

For example, it is possible to improve the acoustic characteristics regardless of the position of the listener by adding speakers for the high frequency range to compensate for the acoustic characteristics in the high frequency range, or by installing multiple speakers in different sound emitting directions. It is. However, this causes a problem that the manufacturing cost is increased and the size of the musical instrument case is inevitably increased.
SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and aims to provide an electronic keyboard instrument having a simple configuration and capable of improving the acoustic characteristics at both the audience side and the performer side. is there.

The present invention includes a keyboard provided near the front of the housing, a main tone hole provided on the back of the housing, and a speaker provided in the housing with the front facing the main tone hole. In the electronic keyboard instrument provided, a subtone hole is provided on the upper surface of the housing within a range of a depth length of the speaker.
According to another aspect of the present invention, a keyboard provided near the front of the housing, a main tone hole provided on the back of the housing, and provided in the housing with the front facing the main tone hole. An electronic keyboard instrument comprising a speaker and a subtone hole having an area smaller than that of the main tone hole in an arrangement corresponding to the speaker on an upper surface of the housing.

  The front of the speaker provided in the housing faces the main tone hole provided on the back of the housing, and the sound output from the front of the speaker is emitted toward the back of the musical instrument (for example, toward the audience). Be sounded. The sound from the front of the loudspeaker is emitted toward the back of the instrument, but the bass range is easily diffracted, so that it resonates well on the side of the player facing the keyboard in front of the instrument. On the other hand, since the subtone hole is formed in the upper surface of the housing, acoustic vibration from the side of the speaker is emitted upward from the subtone hole. The sound emitted upward from the subtone hole is easy to be heard by a player located in front of the musical instrument, so that the missing component in the diffracted sound, particularly the high-range component, is supplemented. Therefore, the treble range does not drop on the player side. Also, behind the musical instrument (for example, on the audience side), the bass range is emphasized and the treble range passes well. Therefore, with a simple configuration in which only a subtone hole is provided, the acoustic characteristics can be improved at any position on the audience side and the performer side. In addition, since the subtone hole is provided so as to open within the range of the depth of the speaker, acoustic vibration from the speaker can be efficiently emitted upward. Further, since the subtone hole has an area smaller than that of the main tone hole, sound can be emitted upward at an appropriate volume through the subtone hole at an appropriate volume.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1A is a plan view showing an upper surface of an example of an electronic keyboard instrument according to the present invention, and FIG. 1B is a rear view of the electronic keyboard instrument as viewed from an arrow a. In addition, in the rear view shown in (b), the top and bottom are shown upside down. The housing 1 of the electronic keyboard instrument according to the present embodiment includes a roof plate portion 2 forming a rear upper surface portion, a bottom plate portion 4 forming a bottom surface portion, left and right side plate portions 5a and 5b forming left and right side surface portions, and a back surface portion. , And a mouth bar 6 forming a front surface. A keyboard 3 is arranged on the front upper surface of the housing 1, and an internal mechanism of the keyboard 3 is housed inside the housing 1. An operation panel 9 including various operation switches and the like is provided at a predetermined position of the roof panel 2.

  Inside the housing 1, left and right stereo speakers 12 a and 12 b (shown by dotted lines in FIG. 1) are arranged at predetermined positions near the rear back plate portion 7, and front faces of the speakers 12 a and 12 b are provided. That is, the sound output opening is directed toward the back plate 7 behind the instrument. As shown in FIG. 1B, the rear plate 7 is provided with main tone holes 10a and 10b corresponding to sound outlets on the front surfaces of the left and right speakers 12a and 12b, respectively. In the example shown in the figure, each of the main tone holes 10a and 10b is composed of a set of a plurality of elongated small holes, and each of the small hole sets generally corresponds to the cone size of the speaker, that is, the size of the sound output opening. As described above, the speakers 12a and 12b are disposed with their front faces, that is, sound output ports, facing the corresponding main tone holes 10a and 10b, and the sounds emitted from the speaker front faces are emitted from the main tone holes 10a and 10b. Through the instrument.

  Sub-tone holes 11a and 11b are respectively formed at predetermined locations on the roof panel portion 2 corresponding to the upper sides of the left and right speakers 12a and 12b. FIG. 2 shows an example of the positional relationship between the speaker 12a and the subtone hole 11a, and is a cross-sectional view taken along line XX of FIG. 1A. In the example of the figure, a subtone hole 11a is formed above the core of the speaker 12a attached to the back plate 7. The same applies to the other subtone hole 11b. The upper surface of the subtone hole 11a is covered with a detachable saran net 13. For the sake of illustration, the saran net 13 is not shown in FIG. 1A, and is shown by a dashed line in FIG. A saran net mounting recess 14a is formed around the subtone hole 11a, and the saran net 13 is mounted here. Similarly, a saran net mounting recess 14b is formed in the other subtone hole 11b.

  As an example, the subtone holes 11a and 11b are formed of horizontally long holes as shown in FIG. 1A, and the center Q of the holes is disposed so as to be appropriately shifted from the sound emission axis S of the speaker. Preferably, as shown in this embodiment, the center Q of the subtone hole is preferably shifted from the sound emission axis S of the speaker by a suitable distance d in the left and right side direction of the musical instrument. That is, the left subtone hole 11a is directed leftward in FIG. 1 (a), and the right subtone hole 11b is directed rightward in FIG. 1 (a). It is arranged staggered. Providing the subtone holes 11a and 11b apart from each other in the left-right direction is preferable in terms of sound separation. However, the present invention is not limited to this, and a subtone hole may be provided in an appropriate arrangement above each speaker 12a, 12b.

As shown in FIG. 1A, it is effective to form the subtone holes 11a and 11b in a long hole so that the long sides thereof are perpendicular to the sound emission axis S. However, the shape of the subtone holes 11a and 11b is not limited to a long hole, and may be an appropriate shape such as a circle, an ellipse, and a polygon.
The predetermined location corresponding to the side surface of the loudspeaker where the subtone holes 11a and 11b are to be provided in the roof panel portion 2 may be within the depth H of the loudspeakers 12a and 12b as shown in FIG. Thereby, the acoustic vibration from the speaker can be efficiently emitted upward. However, the present invention is not limited to this, and a subtone hole may be provided at a position slightly out of this range.
The opening area of each of the subtone holes 11a and 11b is smaller than the area of the main tone holes 10a and 10b. For example, approximately 3 to 15 cm ² is a standard, and it is preferably approximately 10 cm ^{2 in} consideration of sound emission performance and the like.

  The roof panel 2 is connected to the rear panel 7 via left and right and center partition plates 8a to 8c (indicated by dotted lines in FIG. 1A). The plates 8a to 8c are connection holding plates for connecting and holding the roof plate portion 2 and the back plate portion 7, and only the plate 8b serves as a partition plate for sound separation. The left and right partition plates 8a and 8c are arranged closer to the side plate portions 5a and 5b than the left and right speakers 12a and 12b, and a central partition plate 8b is located between the speakers 12a and 12b. The partition plates 8a to 8c function as connection reinforcing members for connecting the roof plate portion 2, the rear plate portion 7, and the bottom plate portion 4. That is, as shown in FIG. 2 for the center partition plate 8b, the partition plate 8b is connected to the roof plate portion 2 at the upper end and connected to the bottom plate portion 4 at the lower end. Although not shown, it is connected to the rear plate 7 at the rear end. The same applies to the other partition plates 8a and 8c. For convenience, in FIG. 2, the keyboard portion 3 is schematically indicated by a two-dot chain line, and the detailed structure is omitted. The central partition plate 8b not only functions as the connection reinforcing member, but also has an excellent effect of separating the sound between the left and right speakers 12a and 12b.

  With the above configuration, the front sound output ports of the speakers 12a and 12b face the main tone holes 10a and 10b provided on the back plate 7, and the sound output from the front sound output ports is directed toward the rear of the musical instrument (for example, (Directed in the direction of the audience). The sound from the front sound output port is emitted toward the rear of the instrument, but the bass range is easily diffracted, so that it resonates well even on the player side facing the keyboard 3 on the front of the instrument. Since the subtone holes 11a and 11b are formed at positions corresponding to the upper sides of the left and right speakers 12a and 12b in the roof panel 2, acoustic vibrations from the speaker side are emitted upward from the subtone holes. . The sound emitted upward from the subtone holes 11a and 11b is easy to hear by a player located in front of the musical instrument, so that a component that is insufficient in the diffracted sound, particularly a high-frequency component, is supplemented. For this reason, the high-frequency component, which tends to be insufficient on the player's side, is supplemented, and good acoustic characteristics can be obtained. Behind the musical instrument (for example, on the audience side), the whole-range components are emitted from the main tone holes 10a and 10b, and the acoustic components emitted from the subtone holes 11a and 11b further improve the acoustic characteristics.

Although the present embodiment has been described above, it is preferable that the subtone holes 11a and 11b are arranged as close to the speakers 12a and 12b as possible. In extreme terms, if there is no barrier between the roof panel 2 and the rear panel 7, the treble range can be reached directly. However, in order to raise the bass range by the roof panel 2, the rear panel 7, etc. as an acoustic diaphragm, Does not go so. Therefore, it is desirable that a subtone hole closest to the cone is used as a subtone hole for directly transmitting vibration from the speaker cone back surface.
Then, the upward arrow portion 2X of the cone 12P is good, but since the distance between the rear end face of the roof plate portion 2 and the subtone holes 11a and 11b is small and the strength cannot be maintained, in this embodiment, the subtone holes 11a and The arrangement position of 11b was above the core portion 12M as shown in FIG.
Even in this case, the experimental results were good as described later.

  An example of actual measurement of acoustic characteristics obtained according to this embodiment will be described with reference to FIG. FIG. 3 shows a state in which the electronic keyboard instrument according to the present embodiment is placed on a table having a height of 1 m, and a microphone is installed at a height of approximately 45 cm above the center of the keyboard portion 3 and further about 15 cm in front of the microphone. It shows the frequency characteristics of an acoustic signal obtained by collecting performance sounds generated from the speakers 12a and 12b by the microphone. Since the position of the microphone generally corresponds to the position of the player's ear, the characteristics shown in FIG. 3 correspond to the frequency characteristics of the performance sound heard by the player. The vertical axis indicates the sound pressure level, and the horizontal axis indicates the frequency. According to FIG. 3, the sound pressure level shows a relatively high value between the frequencies of about 200 to 400 Hz, but does not drop so much to about 4 kHz thereafter. Since the range generated by the electronic keyboard instrument is, for example, about 27 Hz to about 4 kHz for 88 keys of a piano, it can be understood that good frequency characteristics can be obtained over the entire required range.

  In the above-described embodiment, the main tone holes 10a and 10b are formed of a set of a plurality of elongated small holes. However, the present invention is not limited to this, and one large hole substantially corresponding to the size of the sound output port of the speaker. In this case, the main tone hole may be covered with a saran net or the like.

  As described above, according to the present invention, it is possible to provide an electronic keyboard musical instrument that has a low-cost, compact, and simple structure, and has excellent acoustic characteristics at both positions on the audience side and the performer side.

(A) is a top view which shows one Example of the electronic keyboard instrument which concerns on this invention, (b) is a rear view of the electronic keyboard instrument which concerns on the Example. FIG. 2 is a sectional view taken along line XX of FIG. 4 is a graph showing an example of actual measurement of frequency characteristics on the player side of the electronic keyboard instrument according to the embodiment.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Housing 2 Roof board part 3 Keyboard part 4 Bottom board part 5a, 5b Side board part 6 Mouth stick part 7 Back board part 8a-8c Partition board 9 Operation panel 10a, 10b Main tone hole 11a, 11b Subtone hole 12a, 12b Speaker 13 Saran net 14a, 14b Saran net mounting recess

Claims (2)

An electronic keyboard including a keyboard provided near the front of the housing, a main tone hole provided on the back of the housing, and a speaker provided in the housing with the front facing the main tone hole. In musical instruments,
An electronic keyboard musical instrument, wherein a subtone hole which is open within a depth length of the speaker is provided on an upper surface of the housing. An electronic keyboard including a keyboard provided near the front of the housing, a main tone hole provided on the back of the housing, and a speaker provided in the housing with the front facing the main tone hole. In musical instruments,
An electronic keyboard instrument, wherein a subtone hole having an area smaller than that of the main tone hole is formed in an upper surface of the housing at a position corresponding to the speaker.

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