JPH0115267Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a novel sound reproduction device that prevents sound leakage. The present invention relates to a sound reproducing device that can suppress the reproduced sound to a range level that does not become noise to general third parties (people who do not want to listen to sound).

[Conventional technology]

As a tool for reproducing and listening to sounds from radio or records, either general stationary speakers, headphones, or earphones are used.
However, if you try to obtain a satisfactory level of volume using speakers, you will inevitably cause discomfort to the surrounding third parties, so it is necessary to reduce the volume or install soundproofing equipment. I needed to secure a room. For this reason, when listening to music alone, people use headphone-type listening equipment to prevent the sound from leaking out to those around them. It is true that the problem of dispersing noise to the surroundings can be solved by using headphones, but in order to ensure that the listeners are satisfied with the reproduced sound with the optimal sound quality and volume that they desire, it is necessary to connect the ears and headphones mechanically. It had to be kept crimped on the ear at all times. In particular, in order to obtain high-fidelity sound in the bass range with a long wavelength, the above-mentioned crimping is essential; if there is a gap between the headphone and the ear, the bass sound will leak out, making it impossible to obtain high-fidelity sound. It will disappear. However, if you continue to press the headphone on for a long time, you will feel discomfort in the pinna of your ear, and in worse cases, the pressure may cause headaches, upset your body's balance, and even cause hearing loss.

Therefore, as a device that does not cause the listener to feel discomfort, a device is provided in which, for example, a small speaker is installed in a small cabinet so that the reproduced sound can be heard close to the listener's ear.

[Problem that the invention attempts to solve]

When such a small speaker system is placed close to the ear, the sound quality may be lacking in bass, but the volume may be somewhat satisfactory. However, the sound is transmitted to those around the listener at a fairly high level, so it has little effect on reducing noise and causes a great deal of trouble to third parties nearby. Therefore, the inventor of the present invention learned that it is possible to bring the speaker alone close to the ear without installing a cabinet or baffle plate, etc., and after conducting further experiments, found the following. In other words, if you place the speakers right in front of your ears, you can get good sound quality and sufficient volume, but if you place the speakers in a position other than right in front of your ears, the air vibrations propagated from the front and back sides of the speakers cancel each other out, causing a significant amount of noise. I found that the volume decreased. However, if the speaker is left alone, sound will leak to the rear side of the speaker, so it cannot be said that the noise suppression effect is perfect.

After that, the inventor of the present invention repeatedly researched various devices, and as a result, it was possible to provide the listener with a small size, good sound quality, and sufficient volume, without the discomfort caused by pressure like the headphones mentioned above. They have completed a sound reproduction device that does not cause noise to the people around them.

[Means for solving problems]

A shielding plate for blocking sound is provided on the back and side sides of the speaker, and a space is provided between the shielding plate and the speaker to guide the sound sent from the back of the speaker to the front side of the speaker. The gist of the present invention lies in that an opening is formed in the surrounding area, and a horn is extended from the periphery of the speaker.

[Effect]

As shown in Figure 2 (schematic diagram), sound propagation occurs through the air as a medium, depending on the density of its vibrations, and the air vibrations on the front side A and back side B of the speaker 1 are propagated in opposite phases. do. Therefore, if the speaker is operated as it is, the air vibrations on the front and back sides of the speaker cancel each other out through the air, making the sound sound very low at a distance from the speaker. This phenomenon is particularly noticeable in the bass range with long wavelengths, and conventional speakers have traditionally used a cabinet or baffle plate to block air from the front and back sides.
However, when a single speaker is brought close to the ear, a sound similar to that reached by air vibrations of the opposite phase on the back side reaches the ear, and the listener hears the sound being radiated from the speaker diaphragm to the front. It is thought that it is possible to hear only the faithfully reproduced sound. Based on this idea, only the reproduced sound radiated from the speaker diaphragm to the front is propagated to the listener's ears, and the sound radiated from the back of the speaker is transmitted by the shielding plate and horn that cover the back side of the speaker. We arrived at a basic configuration in which the waves are propagated to the front of the speaker, and the path difference cancels each other out. As a result, the reproduced sound, especially on the bass side, is no longer radiated to the surroundings, and the level of noise affecting third parties has been significantly reduced. In addition, the sound from the back side of the speaker no longer leaks directly to the back side of the speaker, and the noise outside the listener's ear area is canceled out.

〔Example〕

FIG. 1 shows a typical embodiment of the present invention. A circular opening is provided in the middle of the front plate 13, a speaker 1 is supported and fixed on the edge of the opening, and an opening 3 is provided on the outer peripheral side of the edge to which the speaker 1 is fixed. The opening 3 covers almost the entire area surrounding the outer periphery of the speaker 1, except for the holding portion 11 that connects the edge to which the speaker 1 is fixed and the front plate 13. A cylindrical horn 8 whose diameter increases toward the front is provided from the edge to which the speaker 1 is fixed (the inner circumference of the opening 3). The position in front of the horn 8 is the listener's ear position, and the material of the horn 8 is a soft material (for example, foamed polyurethane, rubber, etc.) so that the listener's ear will not be damaged even if it hits the horn 8.
It is recommended that A horn 7 is provided from the outer periphery of the opening 3, preferably concentrically with the horn 8 and made of the same material. This is because the back and side sides of the speaker 1 are surrounded by the shielding plate 6, so air vibrations on the back side of the speaker 1 are propagated from the opening 3 to between the horns 7 and 8, and the air vibrations on the front side of the speaker 1 are This is to create a structure that allows sound to be transmitted to.

Next, an example in which the sound reproduction device of the present invention is disposed on both sides of a pillow will be explained with reference to FIG. A pillow 2 is placed in the center of a frame 4 to support a head 5. An arm 12 is rotatably supported at both ends of the frame, and a shielding plate 6 having a built-in speaker 1 is rotatably attached to the tip of the arm 12. The shielding plate 6 has a bowl-shaped curved plate shape, and is formed so that its diameter increases toward the ear 10. The material of the shielding plate 6 may be any material as long as it can block and reflect sound, such as synthetic resin or metal. A support plate 13 is provided on the front side of the shielding plate 6, and the speaker 1 is fixed thereto. Further, the support plate 13 is provided with a plurality of perforations 31, so that the sound propagated along the shielding plate 6 can be guided to the front area of the speaker. At this time, instead of the support plate 13, the width of the outer circumferential frame 23 of the speaker 1 may be widened, and the opening 3 or a plurality of perforations 31 may be provided in the wide frame. Next, on the front side of the speaker 1, a cylindrical horn 8 with an enlarged diameter is extended to a position close to the ear, so that the sound of the opposite phase reflected from the back side does not interfere with the sound in front of the speaker 1. , speaker 1
The sound radiated to the front by the diaphragm is efficiently transmitted to the ears. Furthermore, if the distance between the speaker 1 and the ear 10 becomes wide, the sound heard on the front side of the speaker 1 will be canceled out, especially the low-pitched sound, by the opposite phase sound propagated from the back side. That is, in order to prevent this, a horn 8 is provided for the purpose of blocking the sound from the front side and the sound from the back side. In particular, the attachment of the horn 8 is effective in improving transient characteristics and preventing sound diffusion, thereby improving the sound quality that reaches the listener on the front side of the speaker 1. Further, the reason why the horn 7 with an enlarged diameter is provided outside the opening 3 is to enhance the effect of canceling out sounds in the low frequency range. The horn 7 eliminates the increase in the wavelength of sound, thereby promoting the canceling effect of sounds with long wavelengths. Furthermore, when using a speaker with a low minimum resonance frequency, the horn 7 may be omitted since the minimum resonance frequency may rise slightly.

The shape of the plate 6 that covers the back of the speaker 1 may be any shape, such as a rectangular column as shown in Figure 1 or a curved plate as shown in Figure 3. Any shape that reflects light to the front side may be used, and it is recommended that the horns 7 and 8 have a cylindrical shape or a polygonal shape. These also include those that expand or contract in diameter toward the front, and those that extend while remaining the same diameter. Although FIG. 3 shows an example in which the sound reproducing device of the present invention is applied to a pillow (headrest), an amplifier may be built in the pillow, and FIG. By doing so, it is possible to listen while lying down by attaching it to a chair 42 as shown in Figure 5, or removing it from the chair and placing it on a bed or mattress, so it is especially useful in places with strict noise regulations such as hospitals and hotels. suitable for use.

[Effect of idea]

Since the present invention is constructed as described above, there is no need to apply mechanical pressure to the listener's both ears as is the case when using headphones, and the listener can hear sounds ranging from low to high frequencies. The sound can be given at a sufficient volume, and the noise nuisance to third parties can be reduced.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway perspective view showing a typical embodiment of the present invention. Fig. 2 is a schematic diagram illustrating air vibration propagation by a speaker. Fig. 3 is a cross-sectional illustration showing an example of a pillow to which the present invention is applied. 4 and 5 are explanatory diagrams showing other embodiments to which the present invention is applied. 1... Speaker, 2... Pillow, 3... Opening, 4
...Frame, 5...Head, 6...Shielding plate, 7...
Auxiliary horn, 8... Horn, 9... Dust-proof cloth, 10
... Ear, 11 ... Holding part, 12 ... Arm, 1
3... Support plate, 31... Perforation, 41... Frame, 42... Chair.

Claims (1)

[Scope of utility model registration request] This is a sound reproducing device with a built-in speaker, in which a shielding plate is provided on the back side and side of the speaker to block sound, and between the shielding plate and the speaker, the sound transmitted from the back side of the speaker is transmitted to the front side of the speaker. What is claimed is: 1. A sound reproducing device characterized in that a space is provided for leading to the speaker, an opening is formed in a peripheral area surrounding the front side of the speaker, and a horn is provided extending from the peripheral edge of the speaker.