GB2337890A - Housing arrangement for a loudspeaker in a telephone - Google Patents
Housing arrangement for a loudspeaker in a telephone Download PDFInfo
- Publication number
- GB2337890A GB2337890A GB9811671A GB9811671A GB2337890A GB 2337890 A GB2337890 A GB 2337890A GB 9811671 A GB9811671 A GB 9811671A GB 9811671 A GB9811671 A GB 9811671A GB 2337890 A GB2337890 A GB 2337890A
- Authority
- GB
- United Kingdom
- Prior art keywords
- dynamic speaker
- speaker
- assembly
- dynamic
- cavity
- 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- Withdrawn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
- 238000012360 testing method Methods 0.000 claims description 16
- 238000000034 method Methods 0.000 claims description 8
- 238000005259 measurement Methods 0.000 claims description 5
- 238000013022 venting Methods 0.000 claims description 2
- 230000008878 coupling Effects 0.000 claims 1
- 238000010168 coupling process Methods 0.000 claims 1
- 238000005859 coupling reaction Methods 0.000 claims 1
- 238000013461 design Methods 0.000 description 6
- IRLPACMLTUPBCL-KQYNXXCUSA-N 5'-adenylyl sulfate Chemical compound C1=NC=2C(N)=NC=NC=2N1[C@@H]1O[C@H](COP(O)(=O)OS(O)(=O)=O)[C@@H](O)[C@H]1O IRLPACMLTUPBCL-KQYNXXCUSA-N 0.000 description 5
- ZGHQUYZPMWMLBM-UHFFFAOYSA-N 1,2-dichloro-4-phenylbenzene Chemical compound C1=C(Cl)C(Cl)=CC=C1C1=CC=CC=C1 ZGHQUYZPMWMLBM-UHFFFAOYSA-N 0.000 description 3
- 239000002390 adhesive tape Substances 0.000 description 3
- 239000000853 adhesive Substances 0.000 description 2
- 230000001070 adhesive effect Effects 0.000 description 2
- 239000004411 aluminium Substances 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000006073 displacement reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000001228 spectrum Methods 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
- H04R1/2807—Enclosures comprising vibrating or resonating arrangements
- H04R1/2838—Enclosures comprising vibrating or resonating arrangements of the bandpass type
- H04R1/2842—Enclosures comprising vibrating or resonating arrangements of the bandpass type for loudspeaker transducers
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M1/00—Substation equipment, e.g. for use by subscribers
- H04M1/02—Constructional features of telephone sets
- H04M1/03—Constructional features of telephone transmitters or receivers, e.g. telephone hand-sets
-
- 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
- H04R1/025—Arrangements for fixing loudspeaker transducers, e.g. in a box, furniture
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R2499/00—Aspects covered by H04R or H04S not otherwise provided for in their subgroups
- H04R2499/10—General applications
- H04R2499/11—Transducers incorporated or for use in hand-held devices, e.g. mobile phones, PDA's, camera's
Abstract
A dynamic speaker device for a radio telephone having a speaker output port, the device comprising a dynamic speaker assembly having a dynamic speaker diaphragm, the assembly having a hole for passing sound waves generated by the face of the dynamic speaker diaphragm facing away from the speaker output port into a substantially sealed cavity dimensioned to dampen the low frequency response of the dynamic speaker assembly. The cavity is formed by creating a space 17 in the light guide 14 of the radio telephone. The space 17 is slightly larger than the loudspeaker such that the cavity has a volume of approximately 0.5 cm<SP>3</SP>. The light guide 14 is mounted on a printed circuit board 12 held between housing portions 10,11.
Description
1 2337890 1 HOUSING ARRANGEMENT The present invention relates to a dynamic
speaker housing for a radio telephone.
Radio telephone design continues to place emphasis on telephone size and improved audio quality. However, the goal for higher quality audio is at odds with the aim to reduce overall size of radio telephones as smaller speakers result in the loss of low frequency output efficiency.
Two commonly used speakers in radio telephones are piezo-electric and dynamic speakers. However, as piezo-electric elements typically need a larger driving voltage and as the displacement of the piezo-efectric diaphragm is less, dynamic speakers are increasing in popularity.
As such, dynamic speakers have become common place in radio telephone design and increasingly so leak tolerant dynamic speakers.
Non leak tolerant dynamic speakers experience variations in audio quality due to the fluctuating acoustic loads imposed by a user's ear. The result is poor low frequency audio performance that causes speech output through the earpiece to sound thin and weak. Leak tolerant designs offer a more predictable and stable acoustic load across a wide range of users and operating conditions.
However, leak tolerant dynamic speakers typically have a peak in the low frequency response when sealed to the ear. This frequency response can make it difficult for leak tolerant dynamic speakers to pass certain acoustic approval tests. For example in the AMPS/NAMPS market the 'Receive Audio Frequency Response'test in the CTIA AMPSINAMPS Test Plan section 6.3.2 requires that the speaker under a sealed measurement test provide a flat 2 frequency response between upper and lower frequencies. However without the use of filters, which can be large and costly, or the use of signal processing to correct the response, the peak in the speaker bass response will typically cause the speaker to fail the CTIA test. Further, leak tolerant speaker design requires a rear cavity of at least three to four cubic centimetres which is undesirable if the total volume of the telephone is to be kept to a minimum.
In contrast piezo-electric speakers are well suited for CTiA approval in that these speakers typically display a flat frequency response. However, as described above piezo-electric speakers are not well suited for uses which require limited space and drive voltage.
In accordance with one aspect of the present invention there is provided a dynamic speaker device for a radio telephone having a speaker output port, the device comprising a dynamic speaker assembly having a dynamic speaker diaphragm, the assembly having a hole for passing sound waves generated by the face of the dynamic speaker diaphragm facing away from the speaker output port into a substantially sealed cavity dimensioned to dampen the low frequency response of the dynamic speaker assembly.
Preferably, the substantially sealed cavity is less than 0.5 cubic centimetres.
Since the cavity is sealed, changes that affect the remaining enclosed 25 airspace will have no effect on the frequency response of the dynamic speaker.
As the substantially sealed cavity is not vented this makes the internal mechanics of the radio telephone design simpler. which is ideal for irregularly shaped radio telephones.
3 Preferably the substantially sealed cavity is at the rear of the dynamic speaker housing.
in accordance with a second aspect of the present invention there is provided a method for obtaining a substantially flat frequency response for a dynamic speaker during a sealed measurement test, the method comprising venting sound waves generated in a dynamic speaker assembly acting as a Helmholtz low frequency resonator into a substantially sealed cavity dimensioned to dampen the low frequency response of the dynamic speaker.
An example of a method and apparatus according to the invention will now be described with reference to the accompanying drawings, in which:Figure 1 shows the CTIA receive audio mask for CTIA AMPS/NAMPS Test 15 Plan section 6.12-, Figure 2 shows a typical leak tolerant speaker frequency response; Figure 3a shows sectional view of a typical dynamic speaker assembly 20 suitable for providing a leak tolerant frequency response; Figure 3b shows a top plan view of a typical dynamic speaker assembly suitable for providing a leak tolerant frequency response; Figure 3c shows a bottom plan view of a typical dynamic speaker assembly suitable for providing a leak tolerant frequency response; Figure 4 illustrates a dynamic speaker housing in accordance with this invention; 4 Figure 5 shows a frequency response of a dynamic speaker incorporated in a housing in accordance with this invention.
Figure 1 shows the CTIA receive audio mask for the CTIA AMPS/NAMPS Test Plan section 6.3.2. For AMPS radio telephones to obtain CTIA approval the measured frequency spectrum from the speaker under test must fall between the upper limit 1 and the lower limit 2.
The CTIA approval tests are conducted with a sealed artificial ear which present a high impedance path to the speaker under test. The high impedance path enhances the low frequency response of the speaker, which for leak tolerant speakers results in a low frequency resonance, a typical resonance is shown in figure 2. Typically this resonance exhibited in leak tolerant speakers results in the speaker failing to obtain CTIA approval.
Figure 3a shows a dynamic speaker assembly 3 having a recess 4. The assembly 3 is typically made out of a rigid material such as plastic or metal. The dynamic speaker is designed to be suitable for leak tolerance. An acoustic diaphragm 5 is attached over the recess 4 to form a seal. Typically plastic is used for the diaphragm however any suitable material may be used. A coil of wire 6 is attached to the diaphragm 5. An alternating electric current, which is an electrical representation of the sound, is applied to the coil 6 and creates an alternating magnetic field around the coil 6. A permanent magnet 7 is placed in the recess so that its constant magnetic field interacts with the alternating field around the coil 6. This interaction creates a force on the coil 6 resulting in the movement of the coil 6 and attached diaphragm 5. The movement of the diaphragm 5 creates an increase or decrease in air pressure on one side of the diaphragm 5 and a resulting decrease or increase on the other side of the diaghragm resulting in the generation of sound waves. The speaker assembly has at least one hole 8 at the back of the recess. Figure 3a shows two holes, however the invention can work with a single hole or a plurality of holes. The generated pressure waves pass through these holes 8 and in the absence of any interference on these pressure waves allows the assembly 3 to act as a Helmholtz resonator resulting in a low frequency resonance as shown in figure 2.
Figure 3b shows the top of the dynamic speaker assembly 3 with an aluminium cover 19. The aluminium cover 19 has six apertures 20 to allow the sound waves generated by the speaker 5 to be heard by the user.
Figure 3c shows the bottom of the dynamic speaker assembly 3 having two holes.
An example of the implementation of the dynamic speaker assembly is given below:
Assembly diameter Assembly height Recess diameter Diameter of recess holes 20 Diameter of each cover aperture 15mm 2mm 14mm 0.7mm 1Amm A speaker suitable is described in Primo specification number 2C-7117 which is incorporated by reference into this specification.
Figure 4 shows the dynamic speaker assembly as described above incorporated into a dynamic speaker housing 9 in accordance with this invention.
The housing 9 is sandwiched between a telephone front cover 10 and a telephone back cover 11 and comprises a PCB 12, self adhesive ring 13, light guide 14, self adhesive tape 15 and a gasket 16. The light guide 14 is placed 6 on the PCB 12 using the self adhesive ring 13 to create a seal between the light guide 14 and the PCB 12. The light guide 14 has an aperture 17 with a cut away 18 into which the speaker assembly 3 is mounted. A sealed cavity is formed between the speaker assembly, the light guide and the PC13. The size of the cavity is chosen so as to inhibit the Helmholtz resonance formed by the speaker assembly. Typically this cavity will be less than 0.5 cubic centimetres. Over the light guide and part of the speaker assembly is placed a gasket using self adhesive tape to create a seal between the gasket and light guide and part of the speaker assembly. As a person skilled in the art would appreciate that the gasket and self adhesive tape is not directly attached to the speaker diaphragm.
As a result of the dampening of the Helmholtz resonance by means of the minimal sealed cavity, the testing of the speaker assembly, using a sealed ear piece, shows that the speaker assembly exhibits a flattened frequency response in comparison to that of a typical leak tolerant speaker. Hence making the speaker more suitable for obtaining CTIA approval. Figure 5 shows a typical frequency response of a speaker incorporated in a speaker housing in accordance with this invention superimposed over the CTIA receive audio mask for AMPS radio telephones.
Further, minimising the speaker cavity, as described above, allows telephone designers to allocate less space for the speaker housing resulting in smaller phone designs.
The present invention may include any novel feature or combination of features disclosed herein either explicitly or implicitly or any generalisation thereof irrespective of whether or not it relates to the presently claimed invention or mitigates any or all of the problems addressed. In view of the foregoing description it will be evident to a person skilled in the art that various modifications may be made within the scope of the invention. For
7 example, it will be appreciated that a self contained sealed housing could be used in place of existing telephone components.
8
Claims (8)
- A dynamic speaker device for a radio telephone having a speaker output port, the device comprising a dynamic speaker assembly having a dynamic speaker diaphragm, the assembly having a hole for passing sound waves generated by the face of the dynamic speaker diaphragm facing away from the speaker output port into a substantially sealed cavity dimensioned to dampen the low frequency response of the dynamic speaker assembly.
- 2.A dynamic speaker housing according to claim 1 wherein the cavity is less than 0.5 cubic centimetres.
- 3. A dynamic speaker housing according to claim 1 or claim 2 wherein the cavity is at the rear of the dynamic speaker housing.
- A dynamic speaker housing substantially as hereinbefore described with reference to the accompanying drawings.
- 5. A radio telephone comprising a device in accordance with any of claims 1 to 4.
- 6. A method for obtaining a substantially flat frequency response for a dynamic speaker during a sealed measurement test, the method comprising venting sound waves generated in a dynamic speaker assembly acting as a Helmholtz low frequency resonator into a substantially sealed cavity dimensioned to dampen the low frequency response of the dynamic speaker.
- 7. A method of designing a dynamic speaker device as claimed in claim 1, the method comprising selecting the desired dynamic speaker 9 assembly, coupling the assembly to a cavity, performing a sealed measurement test, and adjusting the dimensions of the cavity if the frequency response of the device under this test is not substantially flat.
- 8. A method for obtaining a substantially flat frequency response for a dynamic speaker during a sealed measurement test substantially as hereinbefore described with reference to the accompanying drawings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9811671A GB2337890A (en) | 1998-05-29 | 1998-05-29 | Housing arrangement for a loudspeaker in a telephone |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9811671A GB2337890A (en) | 1998-05-29 | 1998-05-29 | Housing arrangement for a loudspeaker in a telephone |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB9811671D0 GB9811671D0 (en) | 1998-07-29 |
| GB2337890A true GB2337890A (en) | 1999-12-01 |
Family
ID=10832974
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9811671A Withdrawn GB2337890A (en) | 1998-05-29 | 1998-05-29 | Housing arrangement for a loudspeaker in a telephone |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2337890A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2358317A (en) * | 1999-10-15 | 2001-07-18 | Motorola Inc | Speakerphone accessory for a portable telephone |
| CN102668523A (en) * | 2009-12-24 | 2012-09-12 | 诺基亚公司 | An apparatus for use in portable devices |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4637489A (en) * | 1984-09-04 | 1987-01-20 | Nippon Chem-Con Corp. | Electroacoustic transducer |
| WO1991001075A1 (en) * | 1989-07-06 | 1991-01-24 | Nha A/S | Electrodynamic sound generator for a hearing aid |
| US5303209A (en) * | 1993-03-04 | 1994-04-12 | U.S. Philips Corporation | Electroacoustic transducer having a partition wall and a mask wall |
| WO1997000592A2 (en) * | 1995-06-19 | 1997-01-03 | Plantronics, Inc. | Headset with user adjustable frequency response |
-
1998
- 1998-05-29 GB GB9811671A patent/GB2337890A/en not_active Withdrawn
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4637489A (en) * | 1984-09-04 | 1987-01-20 | Nippon Chem-Con Corp. | Electroacoustic transducer |
| WO1991001075A1 (en) * | 1989-07-06 | 1991-01-24 | Nha A/S | Electrodynamic sound generator for a hearing aid |
| US5303209A (en) * | 1993-03-04 | 1994-04-12 | U.S. Philips Corporation | Electroacoustic transducer having a partition wall and a mask wall |
| WO1997000592A2 (en) * | 1995-06-19 | 1997-01-03 | Plantronics, Inc. | Headset with user adjustable frequency response |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2358317A (en) * | 1999-10-15 | 2001-07-18 | Motorola Inc | Speakerphone accessory for a portable telephone |
| GB2358317B (en) * | 1999-10-15 | 2001-12-19 | Motorola Inc | Speakerphone accessory for a portable telephone |
| US6636750B1 (en) | 1999-10-15 | 2003-10-21 | Motorola, Inc. | Speakerphone accessory for a portable telephone |
| CN102668523A (en) * | 2009-12-24 | 2012-09-12 | 诺基亚公司 | An apparatus for use in portable devices |
| US9124977B2 (en) | 2009-12-24 | 2015-09-01 | Nokia Technologies Oy | Apparatus for use in portable devices |
| CN102668523B (en) * | 2009-12-24 | 2015-11-25 | 诺基亚公司 | For the device used in a portable device |
| US10063963B2 (en) | 2009-12-24 | 2018-08-28 | Nokia Technologies Oy | Apparatus for use in portable devices |
Also Published As
| Publication number | Publication date |
|---|---|
| GB9811671D0 (en) | 1998-07-29 |
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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) |