JPH0379920B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a flat speaker in which a rib is provided on the front surface of a diaphragm.

"Prior Art" In the case of a cone-shaped speaker installed in a conventional sealed enclosure or bass reflex type enclosure, the speaker is attached to a buttful plate on the front of the enclosure, so the diaphragm of the speaker, The vibration of the diaphragm drive unit is transmitted to the enclosure via the speaker frame, etc., causing the enclosure to resonate, and the vibration of the speaker diaphragm compresses the air at the rear of the speaker, and the air pressure presses the enclosure wall. The vibrations of the enclosure interfere with the vibrations of the diaphragm of the speaker, that is, the acoustic characteristics of the enclosure affect sound production, and there is a drawback that the original sound cannot be reproduced with high fidelity. Therefore, a planar speaker has been proposed in which the edge of the diaphragm of the speaker is spaced apart from the enclosure to eliminate the negative effects such as resonance of the enclosure on the sound produced by the speaker. In this flat speaker, the strength is insufficient because the front area of the diaphragm is large, so in order to reinforce this, some speakers have a honeycomb rib structure between the two diaphragms.

``Problems to be Solved by the Invention'' However, in such conventional flat speakers, the diaphragm is flat and has a large front surface area, so the sound waves are easily dissipated, especially near the outer periphery of the diaphragm. around the side and back of the diaphragm,
This affects the acoustic characteristics and causes a reduction in the quality of reproduced sound.

SUMMARY OF THE INVENTION An object of the present invention is to provide a flat speaker that solves the above-mentioned problems of conventional speakers.

"Means for Solving the Problems" The present invention has the following configuration in order to achieve the above object. That is, in a flat speaker in which a flat speaker diaphragm is provided inside an enclosure in a non-contact manner with the enclosure,
A large number of ribs are provided on the front surface of the flat speaker diaphragm to hold air containing sound waves and send it out in front of the diaphragm, and the rear side of the enclosure is open.

``Function'' The diaphragm is equipped with many ribs located on the front of the diaphragm, so these ribs hold the air containing the sound waves on the front of the diaphragm and send it forward, causing the sound waves to spread around the 4 circumferences of the diaphragm. The diaphragm does not come into contact with the hollow frame and the rear side of the enclosure is open, preventing resonance between the diaphragm and the enclosure. This prevents interference between the back pressure of the enclosure and the diaphragm, thereby improving the playback quality.

"Embodiment" An embodiment of the present invention will be described below with reference to FIGS. 1 to 7. Reference numeral 1 in Fig. 1 is an inverted T-shaped support stand, and this support stand 1 has a rectangular horizontal plate 1a provided horizontally, a vertical plate 1b in the center, and two inverted inverted plates on the bottom surface of the horizontal plate 1a. A conical projection 1c is provided. Square grooves 1d shown in FIG. 2 are formed at predetermined locations on the vertical plate 1b. Two support stands 1 are arranged parallel to each other and spaced apart from each other, and the square grooves 1d of each of these two support stands 1 are arranged in parallel.
A hollow frame (corresponding to an enclosure) 2 is fitted and supported.

This hollow frame 2 is formed by forming a cylinder 3 having a square cross section into a rectangular frame shape. Holes 4 are formed at both longitudinal ends of the upper and lower parts of the hollow frame 2, and these holes 4 can be opened and closed by lids 5, 5. 6 is a guide plate that guides the lid 5. Tube 3
The inside is densely filled with baked sand 7 that has been dried by baking the sand. Moreover, U-shaped members 8, 8 are provided at the upper part of the hollow frame 2, spaced apart by a predetermined distance, and a bolt 8a and a nut 8b are provided on these U-shaped members 8, 8, respectively. A flange 9 made of sponge is provided on the inner edge of the front side of the hollow frame 2. It goes without saying that the lid 5 is sufficiently fixed so as not to vibrate after the baked sand 7 is filled into the hollow frame 2.

Further, at the rear of the hollow frame 2, a mounting frame 10 is arranged at a predetermined distance from the hollow frame 2, and is constructed of aggregate in a lattice pattern.
It is attached parallel to the hollow frame 2 via stepped rods 11 fixedly provided at the four corners of the rear surface of the frame.

Further, a diaphragm 12 is provided in parallel with the mounting frame 10 and slightly spaced apart (approximately 100 mm in this embodiment) forward from the mounting frame 10 . This diaphragm 12
is made of balsa wood with its fibers oriented in the directions of arrows C and D shown in FIG. 1, and its upper and lower edges are curved toward the front side (left side in FIG. 2). A circular hole 13 is formed in the center of the diaphragm 12, and a large number of ribs 14 are provided on the front surface of the diaphragm 12, intersecting each other and fixed perpendicularly to the front surface of the diaphragm 12. The rib 14 has a tapered cross section with the thickness on the diaphragm 12 side being thicker than the thickness on the tip side, and the average thickness of the rib 14 is approximately 1.5 mm.
The height of the diaphragm 12 from the front is as high as approximately 20 mm, and the height of the central vertical rib 14 is set even higher to approximately 40 mm.

Voice coils (moving coils) 15, which are components of speakers for sound ranges other than high-frequency ranges (e.g., speakers for mid-range sounds, speakers for mid-low range sounds), are installed at four locations on the rear surface of the diaphragm 12, at the top, bottom, left, and right of the diaphragm 12. It is fixed perpendicular to the rear surface. A plurality of ribs 15a made of a piece of wood are bonded to the base of each of these voice coils 15, and the fiber direction is perpendicular to the directions of arrows A and B shown in FIG.
is bonded to the diaphragm 12. The diaphragm 12 is made of resin so that it is allowed to move only in the front-rear direction (in the direction of the arrow AB shown in FIG. 2) inside the hollow frame 2 without contacting the hollow frame 2, and is prevented from moving in other directions. It is suspended by a thread (diaphragm movement regulating means) 16. That is, one end of the string 16 is attached to each of the four corners of the hollow frame 2, and the other end of the thread 16 is attached to the edge of the hole 4 at the center of the diaphragm 12, so that the diaphragm 12 is suspended.

On the other hand, at a location facing each voice coil 15 of the mounting frame 10, a speaker for a range other than the above-mentioned high range (for example, a speaker for a middle range, a speaker for a mid-low range) is provided.
A center pole 17 made of a pipe having a permanent magnet, which is a component of the center pole 17, is partially fitted coaxially with the voice coil 15 and is attached to the voice coil 15 with bolts and nuts so that its position can be freely adjusted. That is,
The voice coil 15 and the center pole 17 having a permanent magnet have a structure similar to that of the cone-type speaker for the above-mentioned range except for the treble range, with the cone (diaphragm) and frame removed. Therefore, the diaphragm 12, the voice coil 15, and the center pole 17 having a permanent magnet constitute a speaker for the range other than the high range.

In addition, a second
The cone 18 passes through the diaphragm 12 as shown in the figure.
is installed. A treble range speaker 19 is provided at a position facing the circular hole 13 on the rear side of the diaphragm 12, facing the circular hole 13. and is attached by a nut.

In addition, when a midrange speaker is used as the speaker for the sound range other than the high range, a separate low temperature range speaker that is separated from the flat speaker for the mid and high range is used as the low temperature range speaker. shall be.

Next, the operation of the speaker configured as described above will be explained. First, for example, mid-range and mid-low range components of the output signal of the amplifier are input to the voice coil 15, and high-range components of the output signal of the amplifier are input to the high-range speaker 19.
Then, the diaphragm 12 vibrates via the center pole 17 having a permanent magnet and the voice coil 15, and the diaphragm of the high-frequency speaker 19 vibrates to produce sound.

At this time, a large number of ribs 1 are provided on the front surface of the diaphragm 12.
4, ribs 14 are also provided on the left and right edges of the front surface of the diaphragm 12, and the upper and lower edges of the diaphragm 12 are curved toward the front side of the diaphragm 12, so that the sound wave on the front side of the diaphragm 12 is generated. Air is retained by these ribs 14 and forced forward of the diaphragm 12. The ribs 14 also have the role of reinforcing the diaphragm, but as mentioned above, they are too large to fulfill this role, and this is because they hold the air in front of the diaphragm 12 as described above. This is to push it forward. Therefore, the sound waves are prevented from scattering to the top, bottom, right and left of the diaphragm, or from circulating to the rear side of the diaphragm 12.

Also, at this time, the diaphragm 12 is only suspended by the threads 16 and is a free edge, so the response to input signals is excellent, and the vibrations of the diaphragm 12 are not transmitted to the hollow frame 2. Moreover, since the hollow frame 2 is filled with baked sand 7, even if the vibration of the diaphragm 12 or other objects is transmitted, it will be converted into thermal energy. Vibration and resonance with the hollow frame 2 are reliably prevented. Therefore, unlike in the past, the acoustic characteristics of the enclosure no longer greatly affect sound production, and the four voice coils 15 are provided at predetermined locations on the diaphragm 12, spaced apart from each other. Since split vibration does not occur and the speaker of this embodiment allows the pure sound of the sounding body (diaphragm) to be directly heard, very clear high quality sound can always be obtained.

In addition, since the high-frequency speaker 19 is placed in the cone 18 of the circular hole 13 provided in the center of the diaphragm 12, the sound localization is good, the sound field is natural, and the high-pitched sound is good. Due to the presence of the cone 18 and the diaphragm 12, the sound waves from the sound range speaker 19 can be prevented from going behind the high range speaker 19, which also contributes to obtaining high sound quality.

Furthermore, since the mounting frame 10 at the rear of the diaphragm 12 is made of aggregate assembled in a lattice shape, and the rear of the diaphragm 12 is open, there is no interference between the back pressure of the hollow frame 2 and the diaphragm 12. can be reliably prevented.

In addition, when using a plurality of speakers of this embodiment, the U-shaped member 8 of the plurality of speakers
It is preferable to fit the connecting square rod 20 inside and fix it with bolts 8a and nuts 8b to connect the plurality of speakers.

Further, even if it is desired to use the speaker of this embodiment in a horizontally elongated state, the support stand 1 matches the hollow frame 2, making this possible.

In the above embodiment, the round high-frequency speaker 9 was provided facing the circular hole 13 and the cone 18, but the present invention is not limited to this, and a rectangular hole may be provided in the diaphragm 12. A ribbon-shaped speaker may be attached to the edge.

Further, in the first embodiment, the circular hole 13
Although the treble range speaker 9 is provided in front of the diaphragm 12, the voice coil 15, and the diaphragm 12, voice coil 15,
A full range speaker may be used for the center pole 17 and the like.

Although the diaphragm 12 was provided inside the hollow frame 2 in the above embodiment, the present invention is not limited to this.
A diaphragm 12 having ribs 14 may be provided inside a normal enclosure, and the rear side of the enclosure may be open.

"Effects of the Invention" According to the present invention, in a flat speaker in which a flat speaker diaphragm is provided inside an enclosure in a non-contact manner with the enclosure, the front surface of the flat speaker diaphragm contains sound waves. Since the enclosure has a large number of ribs that hold air and send it out in front of the diaphragm, and the rear side of the enclosure is open, the ribs on the front of the diaphragm have the role of reinforcing the diaphragm, and also prevent vibrations. In other words, by providing a large number of ribs on the front side of the diaphragm, the air containing the sound waves on the front side of the diaphragm is retained and the air on the front side of the diaphragm is immediately released. Therefore, the sound waves can be reliably sent out to the front of the diaphragm by preventing them from scattering to the top, bottom, left and right of the diaphragm, or from going around to the rear of the diaphragm. In addition, the response to input signals can be extremely improved, and the vibration of the diaphragm is prevented from being transmitted to the enclosure, thereby reliably preventing resonance between the vibration of the diaphragm and other objects and the enclosure. can,
Furthermore, it is possible to prevent interference between the back pressure of the enclosure and the diaphragm, and as a result, the acoustic characteristics of the enclosure do not have a large effect on sound production as in the past, and the pure sound of the sounding body (diaphragm) can be prevented. You can hear the pronunciation directly, and therefore you can always get very clear and high quality sound.

[Brief explanation of drawings]

1 to 7 show an embodiment of the present invention, in which FIG. 1 is a front view, FIG. 2 is a partially cutaway side sectional view, and FIG. 3 is a perspective view of a diaphragm having ribs. Figure 4 is a schematic perspective view showing the rear side of the diaphragm;
The figure is a cross-sectional view of the main part showing the relationship between the cone provided on the diaphragm and the high-frequency speaker, FIG. 6 is a cross-sectional view taken along the - line of FIG. 1, and FIG. 7 is a cross-sectional view of the - line of FIG.
It is a sectional view along a line. 2...Hollow frame, 7...Baked sand (vibration isolation member), 1
0... Mounting frame, 12... Diaphragm, 13... Circular hole (through hole), 14... Rib, 15... Voice coil, 16... Thread (diaphragm movement regulating member), 17...
...Center pole, 19...Treble range speaker.

Claims (1)

[Claims] 1. In a flat speaker in which a flat speaker diaphragm is provided inside an enclosure in a non-contact manner with the enclosure, air containing sound waves is held in front of the flat speaker diaphragm so that air containing sound waves is held in front of the diaphragm. A flat speaker characterized in that a large number of ribs are provided to send out the rear surface of the enclosure, and the rear side of the enclosure is open.