WO2005039236A1

WO2005039236A1 - Resonance box

Info

Publication number: WO2005039236A1
Application number: PCT/IB2004/052033
Authority: WO
Inventors: Etienne Ducrot; Hang M. Teo
Original assignee: Koninklijke Philips Electronics N.V.
Priority date: 2003-10-17
Filing date: 2004-10-08
Publication date: 2005-04-28

Abstract

An apparatus comprising at least one speaker, at least one first compartment for serving as a resonance box for the speaker, at least one second compartment conceived for having a functionality other than to serve as a resonance box, the first compartment and the second compartment being separated by a dividing wall, the dividing wall comprising at least one sound wave passage way for acoustically connecting the first compartment and the second compartment. As a result, the effective space of the resonance box is enlarged by a substantial part of the second compartment, without enlarging the apparatus itself. When using this enlarged effective space for the resonance box, it will have a positive effect on the sound quality. Additionally, a more flexible choice can be made on the speakers used. These positive effects can be achieved without taking up extra space, because of the fact the second compartment also has another functionality than to serve as a resonance box.

Description

Resonance box

The invention relates to an apparatus comprising a speaker and a compartment for serving as a resonance box for said speaker.

EP 0462571 -A 1 discloses a loudspeaker arrangement comprising a speaker and a compartment to serve as a resonance box for the speaker for use in a television receiver cabinet. In order to improve the sound quality of the loudspeaker arrangement, a horn structure is used as a compartment in which the speaker is placed. The space effectiveness of such a horn structure has become more important. Therefore the horn structure in the given patent application has been constructed in a way that it uses part of the original wall members of the television receiver cabinet. Recently, because of using flat displays like LCD displays or Plasma Display Panels (PDP) instead of a Cathode Ray Tubes (CRT) in television receivers or monitors, the importance of space effectiveness of a loudspeaker arrangement in these apparatuses has further increased. This is not only the case with apparatuses comprising a display, but also with other apparatuses where the recent trend of slim and thin looking styling has resulted in constraints on available space for speaker arrangements. Examples of these apparatuses, although not limited thereto, are mini or midi stereo systems, portable music systems or other apparatuses with incorporated speaker(s) like LCD screens, PDP screens, PC-monitors or combinations thereof like LCD Monitor-TV's. A horn structure like presented in the prior art can not be constructed in these apparatuses, even if original wall members of the apparatus cabinet are used as part of these horn structures. The horn structure will take up too much space which is undesirable for the design of a slim and thin looking apparatus.

It is therefore an object of the present invention to design an apparatus in which a larger space for a speaker arrangement is obtained without enlarging the apparatus itself. To this end, the invention provides an apparatus as specified in the independent claims. Advantageous embodiments are defined in the dependent claims. In the prior art, only a first compartment (the horn structure) served as a resonance box for the speaker. However, according to the invention, the effective space of the resonance box is enlarged by a substantial part of a second compartment, the second compartment also having another functionality than to serve as a resonance box. When using this enlarged effective space for the resonance box, it will have a positive effect on the sound quality. It is known in the art, that a speaker compartment which is serving as a resonance box should be as large as possible for an optimal sound quality, especially when the bass production of the speaker is concerned. Additionally, a larger compartment serving as a resonance box also has the advantage of a more flexible choice on speakers placed in the compartment. For example, a higher power speaker also needs a larger resonance box for optimal performance. These positive effects can be achieved without necessarily enlarging the apparatus, because of the fact the second compartment also has another functionality than to serve as a resonance box, which functionality might be needed in the apparatus anyway. Examples of such a functionality for the second compartment is to serve as a housing for input/output connectors, to serve as a housing for cables or to serve as a battery holder. In an embodiment of the invention, a sound wave passage way acoustically connecting the first and the second compartment comprises at least one opening in a dividing wall between the first and the second compartment, the opening being sufficient for the second compartment to function for a substantial part as a resonance box for the speaker. For example, the second compartment may function along with the first compartment as a resonance box as in the case there would not have been a dividing wall between the first and second compartments, i.e. as if it would have been a single compartment as large as the first and second compartments together. It will be sufficient for sound production if the second compartment functions along with the first compartment as a resonance box as if the first compartment would have been enlarged with at least 60 percent, preferably 80 percent of the second compartment without a dividing wall between the compartments. The advantage of this embodiment is that it provides a simple implementation for acoustically connecting the first and the second compartment. In practical embodiments, when the at least one opening occupies at least 20 percent of a surface of the dividing wall, it will be sufficient for the second compartment to function for a substantial part as a resonance box for the speaker. The effectiveness of the sound wave passage way can be further improved by positioning the at least one opening around a center position on the dividing wall, the center position being a position on the dividing wall from where the absolute distance between the dividing wall en the speaker is minimal. For example, when there is a single opening, this opening can be placed on the center position for an optimal effectiveness of the sound wave passage way. Or, when there are two openings, one opening can be positioned left (or above) the center position, and the second opening can be positioned right (or below) the center position. When there are four openings, these openings can be positioned, respectively right, left, above and below the center position. By this positioning, the acoustic connection is placed where it is most needed, i.e. closest to the speaker, which will result in a more effective acoustic connection between the first and the second compartment. The aforementioned and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.

In the drawings: Fig. 1 shows a front view of an LCD monitor comprising a speaker arrangement according to prior art; Fig. 2 shows a back view of the LCD monitor shown in Fig. 1 ; Fig. 3 shows a cross-section of the LCD monitor shown in Fig. 1; Fig. 4 shows a back view of an LCD monitor comprising a speaker arrangement according to an embodiment of the invention; Fig. 5 shows a cross-section of the LCD monitor shown in Fig. 4; Fig. 6 shows a front view of a portable music system comprising a speaker arrangement according to prior art; Fig. 7 shows a back view of the portable music system shown in Fig. 7; Fig. 8 shows a cross-section of the portable music system shown in Fig. 7; Fig. 9 shows a back view of a portable music system comprising a speaker arrangement according to an embodiment of the invention; and Fig. 10 shows a side view of the portable music system shown in Fig. 9.

In Fig. 1, a front view is presented of an LCD monitor 1 comprising a speaker arrangement according to prior art. It is noted that in this case an LCD monitor is chosen as an example, but the invention can also be used with for example PDP screens, PC-monitors, CRT displays, (portable) audio systems or combinations thereof like LCD Monitor-TV's. The LCD monitor 1 comprises an LCD screen 110 for displaying video images. The LCD monitor 1 further comprises a speaker arrangement consisting of a speaker 120 and a first compartment 125 conceived to serve as a resonance box for the speaker 120. The LCD monitor also comprises a further speaker arrangement consisting of a further speaker 140 and a further first compartment 145 conceived to serve as a resonance box for the further speaker 140. In Fig. 2 a back view of the LCD monitor 1 is presented. In this figure, it is depicted that the first compartment 125 and the further first compartment 145 may be separated from each other by means of compartment walls 126 and 146 respectively. By this separation the speakers arrangements can function more individually for example to possibly obtain better stereo sound reproduction, but the separation is not necessary. In Fig. 2 it is shown that the LCD monitor 1 also comprises a second compartment 130 and a further second compartment 150. It is noted that in the case of the example, the second compartments are normally covered by a removable cover as shown in Fig. 3. In Fig. 3, a cross-section of the LCD monitor 1 is presented according to viewing line III-III. In Fig. 2, the second compartments are not covered in order to present their functionality. The second compartment 130 for example functions as a housing for hiding cables 133, 135 connected to input/output connectors 132, 134 of the LCD monitor 1. These input/output connectors can for example be video input/output, audio input/output, power supply, control or antenna connectors. The cables 133, 135 can be hidden in the second compartment 130 and they can be connected to outside connectors like for example a power supply through a cable passageway 136. The further second compartment 150 serves as a housing for hiding input/output connectors 152, 154 of the LCD monitor 1. As in the case of the second compartment 130, when a cable is connected to one of these input/output connectors 152, 154, the cable can be hidden and can pass through the wall of the apparatus via cable passageway 156. Possibly, passageways 156 or 136 can be closed for example by a plastic or rubber plug when they are not used. Fig. 4 shows a back view of an LCD monitor 2 comprising a speaker arrangement according to an embodiment of the invention. Corresponding parts of LCD monitor 1 and LCD monitor 2 are indicated by the same reference signs. The front view of LCD monitor 2 is the same as the front view of LCD monitor 1 presented in Fig. 1. In Fig. 5, a cross-section of the LCD monitor 2 is presented according to viewing line V-V. In order to create a relatively large space for a speaker arrangement without enlarging the LCD monitor 2 in comparison to LCD monitor 1, the first compartments 125, 145 are acoustically connected to the second compartments 130, 150 by means of a sound passageway, e.g. comprising openings 200, 210, 220. Through these openings 200, 210, 220, air can flow between the first and the second compartments. As a result, effectively the first compartment is enlarged by at least part of the second compartment to serve as an enlarged resonance box. It is generally known that a larger resonance box will improve the sound quality especially when bass audio reproduction is concerned. A further advantage is that a more flexible choice can be made regarding the choice of the speaker. For example, it is generally known that for a higher power speaker, a larger resonance box will be needed for optimal audio reproduction. It is noted, that a person skilled in the art might come up with other designs for a sound passage way between the first and second compartments. One might use a metal or plastic grid instead of a wall with openings in it. Also the number and size of openings in the connecting walls between the first and second compartments can be chosen freely. Moreover, the openings do not need to be equal to each other, but might differ in size. Additionally, the openings do not need to have equal distances to each other. A variable size and distances of the openings can be useful in order to design an optimal sound passageway. The size and distances of the openings can for example be variable in dependence on their distances to the speaker. For example, the openings can be positioned around a center position on the dividing wall, the center position being a position on the dividing wall from where the absolute distance between the dividing wall and the speaker is minimal. More openings can be positioned around the center position for an optimal acoustic connection. Or larger openings can be position close to the center position and smaller openings further away from the center position. Also, when for example a higher tone speaker and a lower tone speaker are used in the same speaker arrangement, it can be chosen to use another sound passageway close to the higher tone speaker than the sound passageway close to the lower tone speaker. It is noted that the design of a sound passageway should be such that the second compartment may in a way still function as intended for the other functionality. It is further noted that it is also possible that the second cabinet 130 and the further second cabinet 150 are implemented by a single second cabinet or otherwise acoustically connected to each other. Fig. 6 presents a front view of a portable music system 3 comprising a speaker arrangement according to prior art. The portable music system comprises a speaker 320 and a further speaker 340 for stereo sound reproduction. The portable music system 3 further comprises a display 310 for displaying information about the cureent functionality of the portable music system 3 like for example the current radio station that is tuned in to by an incorporated tuner. The portable music system 3 also comprises a storage medium 312. This storage medium can be a removable storage medium like a Compact Disk which can be used to store the audio recorded on this medium 312. The portable music system 3 further comprises a control unit 314 for controlling the functions of the system 3. In Fig. 7 shows a back view of the portable music system 3. The speakers 320, 345 are placed in a first compartment 325 and a further first compartment 345, respectively, that are conceived to serve as a resonance box. The first compartments 325, 345 may be acoustically separated from each other by means of internal walls 326, 346, but this is not necessary. The portable music system further comprises a second compartment 350 conceived to serve as a battery holder. Batteries can be placed in the battery holder between connector 352 and spring 354 which also serves as a connector. If batteries are not placed in the battery holder, the portable music system 3 may be connected to an external power source. It is noted that in the case of the example, the second compartment 350 is normally covered by a removable cover as shown in Fig. 8. In fig. 8. a cross-section is presented of the portable music system 3 according to viewing line VIII- VIII. Fig. 9 shows a back view of a portable music system 4 comprising a speaker arrangement according to an embodiment of the invention. Corresponding parts of portable music system 3 and portable music system 4 are indicated by the same reference signs. The front view of the portable music system 4 is the same as the front view of the portable music system 3 presented in Fig. 6. In Fig. 10, a cross-section of the portable music system 4 is presented according to the viewing line X-X. In order to create a relatively large space for a speaker arrangement without enlarging the portable music system 4 in comparison to the portable music system 3, the first compartments 325, 345 are acoustically connected to the second compartment 350 by means of a sound passage way, e.g. comprising openings 400, 410, 420. Through these openings 400, 410, 420, air can flow between the first compartments and the second compartment. As a result, effectively the first compartments are enlarged by at least part of the second compartment to serve as enlarged resonance boxes. In the case of this example, because of the sound passageways, the first compartments 325, 345 are acoustically connected with each other as both compartments use the second compartment 350 as extra space to serve as a resonance box. Therefore, in this case, there is a trade off between the positive effects of having a relative large resonance box without enlarging the apparatus itself and the negative effects of acoustically connecting the first compartments 325, 345 with each other. The positive effects are the same as discussed with the example of the LCD monitor 2. A negative effect of acoustically connecting the first compartments 325, 345 might be a less individual sound reproduction per speaker 320, 340 which may have its influence on stereo sound reproduction. Optionally, the first compartments 325, 345 may be acoustically separated from each other, for example by means of at least one removable compartment wall. In this example, the removable compartment wall can be placed inside the second compartment 350 when the second compartment 350 does not comprise a battery. Another possibility to acoustically separate the first compartments 325, 345 is to implement the second compartment 350 as two second compartments. Batteries can be placed in both of the two second compartments, which two second compartments can be electrical connected to each other in order to function as a single battery compartment. For the sound passageway, the same design possibilities hold as discussed with the example of the LCD monitor 2. It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs between parenthesis shall not be construed as limiting the claim. The word 'comprising' does not exclude the presence of other elements than those listed in a claim. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Claims

1. An apparatus comprising at least one speaker (140, 340), at least one first compartment (145, 345) for serving as a resonance box for said speaker (140, 340), at least one second compartment (150, 350) conceived for having a functionality other than to serve as a resonance box, said first compartment and said second compartment being separated by a dividing wall, said dividing wall comprising at least one sound wave passage way (200, 400) for acoustically connecting said first compartment (145, 345) and said second compartment (150, 350).

2. An apparatus as claimed in claim 1, wherein said sound wave passage way comprises at least one opening (200, 400) in said dividing wall between said first compartment (145, 345) and said second compartment (150, 350), said at least one opening (200, 400) being sufficient for said second compartment (150, 350) to function for a substantial part as a resonance box for said speaker (140, 340).

3. An apparatus as claimed in claim 2, wherein said at least one opening (200,

400) occupies at least 20 percent of a surface of said dividing wall.

4. An apparatus as claimed in claim 3, wherein said at least one opening (200, 400) is positioned around a center position on said dividing wall, said center position being a position on said dividing wall from where the absolute distance between said dividing wall and said speaker is minimal.

5. An apparatus as claimed in claim 1, wherein said functionality of said second compartment is to serve as a housing (150) for input/output connectors of said apparatus.

6. An apparatus as claimed in claim 1, wherein said functionality of said second compartment is to serve as a housing (130) for cables connected to said apparatus.

7. An apparatus as claimed in claim 1, wherein said functionality of said second compartment is to serve as a battery holder (350).

8. A monitor (2) comprising a display (110) for displaying video images and an apparatus as claimed in claim 1.

9. A portable music system (4) comprising a display (310) for displaying information about the current functionality of the portable music system (4), a storage medium (312) for storing audio data, a control unit (314) for controlling the functions of the portable music system (4) and an apparatus as claimed in claim 1.