GB2301727A - Interior of loudspeaker cabinet includes projections to prevent standing waves - Google Patents
Interior of loudspeaker cabinet includes projections to prevent standing waves Download PDFInfo
- Publication number
- GB2301727A GB2301727A GB9510172A GB9510172A GB2301727A GB 2301727 A GB2301727 A GB 2301727A GB 9510172 A GB9510172 A GB 9510172A GB 9510172 A GB9510172 A GB 9510172A GB 2301727 A GB2301727 A GB 2301727A
- Authority
- GB
- United Kingdom
- Prior art keywords
- loudspeaker
- enclosure
- loudspeaker system
- tapered bodies
- tapered
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 239000000463 material Substances 0.000 claims description 8
- 239000011358 absorbing material Substances 0.000 claims description 6
- 230000002745 absorbent Effects 0.000 claims description 4
- 239000002250 absorbent Substances 0.000 claims description 4
- 239000004033 plastic Substances 0.000 claims description 4
- 229920003023 plastic Polymers 0.000 claims description 4
- 239000007787 solid Substances 0.000 claims description 4
- 230000001419 dependent effect Effects 0.000 claims 1
- 230000006870 function Effects 0.000 description 4
- 230000009286 beneficial effect Effects 0.000 description 3
- 230000009102 absorption Effects 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- -1 polypropylene Polymers 0.000 description 2
- 239000004743 Polypropylene Substances 0.000 description 1
- 239000011093 chipboard Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000003365 glass fiber Substances 0.000 description 1
- 238000001746 injection moulding Methods 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 230000011514 reflex Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R1/00—Details of transducers, loudspeakers or microphones
- H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
- H04R1/22—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired frequency characteristic only
- H04R1/28—Transducer mountings or enclosures modified by provision of mechanical or acoustic impedances, e.g. resonator, damping means
- H04R1/2869—Reduction of undesired resonances, i.e. standing waves within enclosure, or of undesired vibrations, i.e. of the enclosure itself
- H04R1/2884—Reduction of undesired resonances, i.e. standing waves within enclosure, or of undesired vibrations, i.e. of the enclosure itself by means of the enclosure structure, i.e. strengthening or shape of the enclosure
- H04R1/2888—Reduction of undesired resonances, i.e. standing waves within enclosure, or of undesired vibrations, i.e. of the enclosure itself by means of the enclosure structure, i.e. strengthening or shape of the enclosure for loudspeaker transducers
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R1/00—Details of transducers, loudspeakers or microphones
- H04R1/02—Casings; Cabinets ; Supports therefor; Mountings therein
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R1/00—Details of transducers, loudspeakers or microphones
- H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
- H04R1/22—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired frequency characteristic only
- H04R1/28—Transducer mountings or enclosures modified by provision of mechanical or acoustic impedances, e.g. resonator, damping means
- H04R1/2869—Reduction of undesired resonances, i.e. standing waves within enclosure, or of undesired vibrations, i.e. of the enclosure itself
- H04R1/2876—Reduction of undesired resonances, i.e. standing waves within enclosure, or of undesired vibrations, i.e. of the enclosure itself by means of damping material, e.g. as cladding
- H04R1/288—Reduction of undesired resonances, i.e. standing waves within enclosure, or of undesired vibrations, i.e. of the enclosure itself by means of damping material, e.g. as cladding for loudspeaker transducers
Landscapes
- Health & Medical Sciences (AREA)
- Otolaryngology (AREA)
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Signal Processing (AREA)
- Details Of Audible-Bandwidth Transducers (AREA)
Abstract
A loudspeaker system 1 comprising a loudspeaker enclosure 2 and at least one loudspeaker drive unit 3, 4 mounted in the enclosure is provided with means 9 projecting into the interior of the enclosure from one or more walls thereof to roughen acoustically the surface of the said one or more walls. The means 2 may approximate in shape to a fractal function. The means 2 may comprise a multiplicity of tapered bodies projecting into the interior of the enclosure from one or more walls thereof.
Description
LOUDSPEAKER SYSTEMS
This invention relates to loudspeaker systems.
In a loudspeaker system comprising a loudspeaker enclosure, and at least one loudspeaker drive unit mounted in the enclosure, care has to be taken of internal resonant frequencies within the enclosure if the sound reproduction provided by the loudspeaker is to be satisfactory.
It is an object of the invention to provide an improved loudspeaker system in which means are provided to control the internal resonant frequencies of the loudspeaker enclosure.
That object is achieved in accordance with the invention by providing means projecting into the interior of the enclosure from one or more walls thereof to roughen acoustically the surface of the said one or more walls.
By that means, one or more internal surfaces of the loudspeaker enclosure can be made sufficiently rough acoustically to reduce the presence of parallel surfaces between which standing waves may form. The waves travelling within the enclosure therefore become diffuse (that is, energy flows more or less equally in all directions) and thus there is a reduction in preferred directions such as would allow energy to build up into resonances.
Ideally, the internal surfaces of the enclosure are made to appear rough acoustically at all audio frequencies so that there remain no parallel surfaces between which standing waves may form at any audio frequency. That would require the walls to appear rough at whatever magnification they were examined in the same way as the well-known "fractal" images never become exhausted of detail no matter how much they are magnified.
The means may approximate in shape to a fractal function. For example, the means may be fractal over a range extending from a 1 millimetre scale to a 1 metre scale. The fractal function may, for example, be a Julia or Mandelbrot fractal.
The means may comprise a multiplicity of tapered bodies projecting into the interior of the enclosure from one or more walls thereof.
The tapered bodies may have smaller tapered bodies projecting from them transversely, and the smaller tapered bodies may have even smaller tapered bodies projecting transversely in turn from them, and so on and so on to approximate a fractal function. Otherwise, they may be straightforward tapered bodies.
Preferably, the enclosure has a front wall on which the at least one drive unit is mounted, and a rear wall from which the multiplicity of tapered bodies project towards the front wall. If other walls of the enclosure also have tapered bodies projecting from them, the tapered bodies may pass between each other but it then becomes difficult to fill a wall totally with tapered bodies and to make some or all of the bodies long enough to extend right across the enclosure, that being a preferred arrangement.
Advantageously, the length of the tapered bodies is greater than one half the wavelength of an audio frequency at which the at least one drive unit operates.
Incident sound waves the half wavelengths of which are equal to or smaller than the lengths of the tapered bodies will suffer multiple reflections and thus when they finally escape from the multiplicity of tapered bodies their direction of travel will have become randomized and thus diffuse. Thus, standing waves or acoustic resonances having frequencies above the halfwavelength equals body lengths criterion will be largely defeated. The effect will continue to be beneficial even where the half-wavelength is larger than the lengths of the tapered bodies since the phase of parts of the wavefront will be changed by that fraction of the wavelength represented by the tapered body in question.
Thus, any reflected wave will no longer be able to add up in phase so effectively, and thus the Q or strength of any acoustic resonances formed will be lowered and thus improved (from the point of view of suppressing resonances). Even when relatively long wavelengths are present the multiplicity of tapered bodies can still be expected to provide a beneficial effect.
Advantageously, the tapered bodies occupy between 1/16 and 3/16 of the internal volume of the loudspeaker enclosure. The fraction 1/8 represents the volume taken by a pyramid within a cube where the pyramid totally occupies the bottom face of the cube and comes to a point at the top face of the cube. In applying the invention, that hypothetical pyramid may be notionally split into a multiplicity of smaller pyramids occupying the same volume, the totality of the smaller pyramids filling the bottom face and the points of which all touch the top face.
The tapered bodies may be of a circular crosssection or of a polygonal cross-section such as a rectangular or square cross-section.
Advantageously, some of the tapered bodies may provide a means of mounting a component of the system.
The tapered bodies may be hollow and optionally the hollow interior of the tapered bodies is open to the exterior of the loudspeaker enclosure. For example, the rear surface of the loudspeaker system may be totally covered with pyramid shapes which protrude into the inside of the enclosure. From the outside of the loudspeaker system, the pyramid shapes are visible as pyramid-shaped holes which has the advantage that a person buying such a system can recognize the presence of the pyramid shapes. From the inside of the enclosure, the pyramid shapes appear as long, thin, tapering pyramid-shaped spikes which totally fill the rear surface of the enclosure.
The hollow tapered bodies may be filled with sound absorbing material to reduce the possibility of resonance occurring within them. Preferably, the hollow interiors of the tapered bodies are then closed off to prevent the sound absorbing material from escaping from the bodies.
Advantageously, one or more through holes are formed in the wall of each sound absorbing material-filled tapered body to communicate with the sound absorbing material and give the tapered bodies sound absorbing properties. A multiplicity of small holes similar to those used in absorption panels for ceilings may be provided. Sound then suffers multiple reflections and hence multiple absorptions from the surfaces of the tapered bodies. The overall result is that little energy of frequencies corresponding to wavelengths smaller than the length of the tapered bodies escape from the surface of the tapered bodies.
Alternatively, the tapered bodies may be solid.
Although solid tapered bodies will be substantially ineffective in absorbing energy, beneficial results can still be expected for the reasons explained above.
Advantageously, the loudspeaker enclosure is made up of a plurality of walls of which no two are parallel to each other. Although such a measure was known to be effective on its own to prevent any really strong standing waves building up between any combinations of box walls at a given frequency, it was unsatisfactory to use alone because departures from parallelism of the outside of an enclosure are difficult to make acceptable aesthetically and, moreover, it is generally desirable to maximize the internal volume of the enclosure for a given outer volume.
Advantageously, the interior of the loudspeaker enclosure includes acoustically absorbent material. On its own, acoustically absorbent material is fully effective only within large totally enclosed enclosures but when combined with the use of tapered bodies according to the invention, it is of significant value in smaller enclosures and enclosures, such as bass reflex enclosures, that are not totally enclosed.
The tapered bodies may be integrally formed of plastics material with a wall of the loudspeaker enclosure.
Loudspeaker systems constructed in accordance with the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
Fig. 1 is a rear elevation of a rear wall of the enclosure of a loudspeaker system according to the invention;
Fig. 2 is a cross-section taken along the line II-II marked in Fig. 1;
Fig. 3 is a cross-section, partly diagrammatic, through the loudspeaker system, the rear wall being sectioned in accordance with the line III-III marked in
Fig. 1; and
Fig. 4 is a front elevation of the component of
Fig. 1.
Referring to the accompanying drawings, a loudspeaker system 1 comprises a loudspeaker enclosure 2; and two loudspeaker drive unit 3 and 4 mounted in the enclosure. The enclosure 2 is of rectangular box-like form and comprises a rear wall 5 of plastics material and walls of chipboard comprising a front wall 6, top wall 7, bottom wall 8 and two side walls (not shown).
The drive unit 3 is a high-frequency drive unit (usually called a "tweeter") mounted within its own enclosure on the rear of the front wall 6. The drive unit is a low frequency drive unit and has its rear open to the interior of the enclosure 2.
Forty-three tapered bodies 9 project into the interior of the enclosure 2 from the rear wall 5 thereof.
The bodies 9 roughen acoustically the surface of the wall 9.
The drive units 3 and 4 are mounted on the front wall 6 on which the at least one drive unit is mounted, and the multiplicity of tapered bodies 9 on the rear wall 5 project towards the front wall. The tapered bodies 9 are of rectangular cross-section and define slender pyramids strengthened by interconnecting plates 15. The tapered bodies 9 are integrally formed of plastics material with the rear wall by injection moulding of polypropylene.
The tapered bodies 9 are hollow, the hollow interior of the tapered bodies is open to the exterior of the loudspeaker enclosure (see Fig. 1).
Six of the tapered bodies, these six being referenced 10, extend fully across the enclosure and are each arranged to receive a respective screw (not shown) to enable the rear wall 5 to be mounted on the rear of the front wall 6. Four of the tapered bodies, these four being referenced 11, extend partially across the enclosure and are each arranged to receive a respective screw (not shown) to enable a cross-over network (not shown) to be mounted in the enclosure.
The rear wall 5 includes a plane area with four holes 13 for the mounting of connecting terminals (not shown).
The interior of the loudspeaker enclosure 2 includes acoustically absorbent material, for example, glass fibre, illustrated diagrammatically as reference 14.
The dimensions of the loudspeaker system may, for example, be 180 millimetres wide, 320 millimetres high and 185 millimetres deep but the invention may be applied to much larger loudspeaker systems, for example, an enclosure of internal volume 200 litres. It is contemplated that a loudspeaker enclosure of internal volume as great as 1000 litres could embody the invention.
Whenever spatial considerations permit, the length of the tapered bodies should be greater than one half the wavelength of an audio frequency at which the drive unit(s) operate. A frequency of 20 kilohertz (which many young persons are capable of hearing) has a wavelength of one foot.
The tapered bodies preferably occupy between 1/16 and 3/16 of the internal volume of the loudspeaker enclosure.
If styling and spatial considerations permit, the loudspeaker enclosure can advantageously be made up of a plurality of walls of which no two are parallel to each other (not shown in the drawings).
Although pyramidal tapering bodies are shown in the drawings, bodies of virtually any tapering shape can be used, for example, bodies of other polygonal sections or of circular section. There can be virtually any number of them, they can protrude from virtually any internal surface of the enclosure, their lengths can be chosen from a very wide range of values as can the fraction of the volume of the enclosure which they fill. They may be solid rather than hollow.
Instead of straightforward tapering bodies, shapes approximating to fractal functions can be employed.
Claims (20)
1. A loudspeaker system comprising:
a loudspeaker enclosure; and
at least one loudspeaker drive unit mounted in the enclosure; characterized by:
means projecting into the interior of the enclosure from one or more walls thereof to roughen acoustically the surface of the said one or more walls.
2. A loudspeaker system as claimed in claim 1, wherein the means approximate in shape to a fractal function.
3. A loudspeaker system as claimed in claim 1, wherein the means comprises a multiplicity of tapered bodies projecting into the interior of the enclosure from one or more walls thereof.
4. A loudspeaker system as claimed in claim 3, wherein the enclosure has a front wall on which the at least one drive unit is mounted, and a rear wall from which the multiplicity of tapered bodies project towards the front wall.
5. A loudspeaker system as claimed in claim 3 or claim 4, wherein the length of the tapered bodies is greater than one half the wavelength of an audio frequency at which the at least one drive unit operates.
6. A loudspeaker system as claimed in any of claims 3 to 5, wherein the tapered bodies occupy between 1/16 and 3/16 of the internal volume of the loudspeaker enclosure.
7. A loudspeaker system as claimed in any one of claims 3 to 6, wherein the tapered bodies are of a circular cross-section.
8. A loudspeaker system as claimed in any one of claims 3 to 7, wherein the tapered bodies are of a polygonal cross-section.
9. A loudspeaker system as claimed in claim 8, wherein the tapered bodies are of rectangular crosssection.
10. A loudspeaker system as claimed in any one of claims 3 to 9, wherein some of the tapered bodies provide a means of mounting a component of the system.
11. A loudspeaker system as claimed in any one of claims 3 to 10, wherein the tapered bodies are hollow.
12. A loudspeaker system as claimed in claim 11, wherein the hollow interior of the tapered bodies is open to the exterior of the loudspeaker enclosure.
13. A loudspeaker system as claimed in claim 11, wherein the hollow tapered bodies are filled with sound absorbing material.
14. A loudspeaker system as claimed in claim 13, wherein the hollow interiors of the tapered bodies are closed to the exterior of the loudspeaker of the loudspeaker enclosure.
15. A loudspeaker system as claimed in claim 13 or claim 14, wherein one or more through holes are formed in the wall of each sound absorbing material-filled tapered body.
16. A loudspeaker system as claimed in any one of claims 3 to 10, wherein the tapered bodies are solid.
17. A loudspeaker system as claimed in any preceding claim, wherein the loudspeaker enclosure is made up of a plurality of walls of which no two are parallel to each other.
18. A loudspeaker system as claimed in any preceding claim, wherein the interior of the loudspeaker enclosure includes acoustically absorbent material.
19. A loudspeaker system as claimed in one of claims 3 to 16, or either of claims 17 and 18 when dependent on claim 3, wherein the tapered bodies are integrally formed of plastics material with a wall of the loudspeaker enclosure.
20. A loudspeaker system substantially as herein described with reference to, and as illustrated by, the accompanying drawings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9510172A GB2301727A (en) | 1995-05-19 | 1995-05-19 | Interior of loudspeaker cabinet includes projections to prevent standing waves |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9510172A GB2301727A (en) | 1995-05-19 | 1995-05-19 | Interior of loudspeaker cabinet includes projections to prevent standing waves |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB9510172D0 GB9510172D0 (en) | 1995-07-12 |
| GB2301727A true GB2301727A (en) | 1996-12-11 |
Family
ID=10774734
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9510172A Withdrawn GB2301727A (en) | 1995-05-19 | 1995-05-19 | Interior of loudspeaker cabinet includes projections to prevent standing waves |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2301727A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1292170A2 (en) | 2001-09-05 | 2003-03-12 | Samsung Electronics Co., Ltd. | Structure for preventing the generation of standing waves and a method for implementing the same |
| EP1315399A2 (en) * | 2001-11-26 | 2003-05-28 | Tenovis GmbH & Co. KG | Filtering device in acoustic housing for microphones in communication apparatuses |
| WO2011138468A1 (en) * | 2010-05-03 | 2011-11-10 | Moreton Cesteros Angel Julio | Acoustic enclosure for loudspeakers |
| US20150027805A1 (en) * | 2013-07-29 | 2015-01-29 | Usher Audio Technology | Speaker enclosure and method for fabricating the same |
| WO2015076703A1 (en) * | 2013-11-22 | 2015-05-28 | Валентин Валерьевич КАЗАНЖИ | Headphone device for reproducing sound (variants) and headset |
| CN114640910A (en) * | 2021-04-05 | 2022-06-17 | 李南海 | Loudspeaker with cone |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB512610A (en) * | 1938-03-03 | 1939-09-21 | William West | Improvements in or relating to loud speakers |
| GB1321944A (en) * | 1970-03-11 | 1973-07-04 | Bonnard M P R | Sound reproducing devices |
| US4109983A (en) * | 1974-08-22 | 1978-08-29 | Pioneer Electronic Corporation | Speaker cabinet |
| GB2181620A (en) * | 1985-10-11 | 1987-04-23 | Zbigniew Marian Zenkteler | Loudspeaker enclosure |
| US4750585A (en) * | 1987-06-03 | 1988-06-14 | Collings Boyd E | Loudspeaker enclosure for suppressing unwanted audio waves |
| US4869340A (en) * | 1987-06-22 | 1989-09-26 | Coudoux Christian A | Very high performance loudspeaker enclosures |
| GB2245450A (en) * | 1990-06-19 | 1992-01-02 | Canon Kk | Speaker for use in a sound output system |
-
1995
- 1995-05-19 GB GB9510172A patent/GB2301727A/en not_active Withdrawn
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB512610A (en) * | 1938-03-03 | 1939-09-21 | William West | Improvements in or relating to loud speakers |
| GB1321944A (en) * | 1970-03-11 | 1973-07-04 | Bonnard M P R | Sound reproducing devices |
| US4109983A (en) * | 1974-08-22 | 1978-08-29 | Pioneer Electronic Corporation | Speaker cabinet |
| GB2181620A (en) * | 1985-10-11 | 1987-04-23 | Zbigniew Marian Zenkteler | Loudspeaker enclosure |
| US4750585A (en) * | 1987-06-03 | 1988-06-14 | Collings Boyd E | Loudspeaker enclosure for suppressing unwanted audio waves |
| US4869340A (en) * | 1987-06-22 | 1989-09-26 | Coudoux Christian A | Very high performance loudspeaker enclosures |
| GB2245450A (en) * | 1990-06-19 | 1992-01-02 | Canon Kk | Speaker for use in a sound output system |
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1292170A2 (en) | 2001-09-05 | 2003-03-12 | Samsung Electronics Co., Ltd. | Structure for preventing the generation of standing waves and a method for implementing the same |
| EP1292170A3 (en) * | 2001-09-05 | 2004-03-17 | Samsung Electronics Co., Ltd. | Structure for preventing the generation of standing waves and a method for implementing the same |
| US7093688B2 (en) | 2001-09-05 | 2006-08-22 | Samsung Electronics Co., Ltd. | Structure for preventing the generation of standing waves and a method for implementing the same |
| EP1315399A2 (en) * | 2001-11-26 | 2003-05-28 | Tenovis GmbH & Co. KG | Filtering device in acoustic housing for microphones in communication apparatuses |
| EP1315399A3 (en) * | 2001-11-26 | 2008-11-05 | Tenovis GmbH & Co. KG | Filtering device in acoustic housing for microphones in communication apparatuses |
| CN102870437A (en) * | 2010-05-03 | 2013-01-09 | 安赫尔·胡利奥·莫尔顿·塞斯特罗斯 | Acoustic enclosure for loudspeakers |
| WO2011138468A1 (en) * | 2010-05-03 | 2011-11-10 | Moreton Cesteros Angel Julio | Acoustic enclosure for loudspeakers |
| CN102870437B (en) * | 2010-05-03 | 2015-09-16 | 安赫尔·胡利奥·莫尔顿·塞斯特罗斯 | The blimp of loud speaker |
| US20150027805A1 (en) * | 2013-07-29 | 2015-01-29 | Usher Audio Technology | Speaker enclosure and method for fabricating the same |
| US9131301B2 (en) * | 2013-07-29 | 2015-09-08 | Usher Audio Technology | Speaker enclosure and method for fabricating the same |
| WO2015076703A1 (en) * | 2013-11-22 | 2015-05-28 | Валентин Валерьевич КАЗАНЖИ | Headphone device for reproducing sound (variants) and headset |
| CN114640910A (en) * | 2021-04-05 | 2022-06-17 | 李南海 | Loudspeaker with cone |
| EP4072160A1 (en) * | 2021-04-05 | 2022-10-12 | Nam Hae Lee | Loudspeaker with conical reflector arranged in the enclosure |
| JP2022159994A (en) * | 2021-04-05 | 2022-10-18 | ナムヘ イ | speaker with cone |
Also Published As
| Publication number | Publication date |
|---|---|
| GB9510172D0 (en) | 1995-07-12 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 732E | Amendments to the register in respect of changes of name or changes affecting rights (sect. 32/1977) | ||
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |