DE2300502A1 - PORTABLE CALL RECEIVER WITH AN INTEGRATED ACOUSTIC HORN - Google Patents

Description

PATENT LAWYERS DIPL.-ING. LEO FLEUCHAUS

Mtoch.n 7i, January 5, 1973

MelchJowtr. 42

Our symbol: M049P / G-919/20

Motorola, Inc.

9401 West Grand Avenue

Franklin Park »Illinois

V.St.A.

Portable pager with an integrated acoustic horn ■

The invention relates to a portable pager having a. built-in acoustic horn and one from a rectangular Housing removable receiver part, which has an electroacoustic Includes converter.

With portable pagers loudspeakers are used to to make the demodulated audio frequency signals audible for the user.- Although such loudspeakers have been around for a long time used for this purpose they have a number of disadvantages. Such a loudspeaker does not have a flexible one physical form factor and is usually based on one circular or oval design. · Because of the inflexible form factor, the recipient usually has to move around the Loudspeakers are built around and structurally designed, which means that the housing is relatively voluminous

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Dimensions result. In such receivers, the loudspeaker alone can take up about a third of the total volume will.

It is also known that speakers with a relative poor efficiency work. Therefore, relatively high performance and complex circuits are required, to generate sound waves with an amplitude that are emitted at a level value that they are suitable for the user are easy to understand. This greater power requirement also forces the use of larger batteries and thus an increase in volume for the recipient. Another disadvantage arises from the arrangement of the loudspeaker in the housing if the call receiver is built as a portable receiver and is carried by the user in the usual way, e.g. in a breast pocket or on a belt. In this case it is the direction of radiation for the sound waves through the loudspeaker is not in the direction of the user's ear, but directed away from this. This results in a further deterioration in efficiency caused with regard to the evaluation of the existing electrical power.

It has also already been provided for transducers and acoustic Horns in portable radio receivers and pagers too use, the acoustic horn being an exponential horn Is used. This horn must be reasonably large be executed so that · the sound waves with the required Schal'lpegel- are emitted. · The horn and the Transducers represent a unit, so that due to this fact and the configuration of an exponential horn results in an arrangement that is very large and voluminous. For this reason, the arrangement with the horn is usually used provided as a separate unit, which is arranged e.g. on the side wall of a radio receiver. Such a recipient is usually so large in terms of its dimensions and

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misshapen that it is difficult to carry it in a loop or on a belt. Both the size of the exponential horn as well as its form factor do not allow the sound waves to be radiated in the direction of the user's ear, when the receiver is carried in a pocket or on a belt.

If the transducer and the horn are designed and mounted as a separate unit outside the receiver, it does Difficulty removing the receiver part as a complete unit and subjecting it to a test. However, it is For this purpose, it is desirable that the receiver part including the electro-acoustic transducer can easily be removed from the Housing removed and inserted and checked in a test unit provided for this purpose. That way it is possible to create a receiver part that is an integrated unit independent of the actual housing of a call receiver Can be used and thus can be used much more universally.

The invention has for its object to provide a portable pager or radio receiver in which a acoustic horn is integrated in the receiver housing and the removable · receiver part includes the electro-acoustic transducer, which is easily removed from the housing of the acoustic Hornes is removable. The removable receiver part should be independent with the electro-acoustic converter Unit to be functional. The acoustic horn should allow miniaturization in its design, without the efficiency being significantly impaired.

This object is achieved by the invention in that the housing is divided into two adjacent ones, which are divided by a partition and longitudinally extending

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Compartments is subdivided, the first compartment being provided for receiving the receiver part and a passage designed as an acoustic horn and sound vibrations amplifying passage being designed in the second compartment, and that an acoustic chamber is mounted in the first compartment, which the sound vibrations between the transducer and the Horn transmits ¹ .

According to a further feature of the invention, it is provided that that-to the electro-acoustic converter and the acoustic Chamber, which in the area of the upper end face next to the Partition wall are arranged, subsequent acoustic horn with a first section from the upper end face into the Area of the lower end face, and merges there into a further section via a curved section, which runs from the lower end face to the upper end face and into an opening arranged in the upper end face opens, and that the cross-section of the sections forming the horn is approximately a hyperbolically enlarging one Has cross-sectional area.

In the case of an acoustic horn constructed in this way, the invention is configured such that the acoustic horn has a primary resonance frequency at about 2000 Hz, and that the The resonance frequency of the acoustic reflection is approximately 700 Hz. ■

Further features of the invention are the subject of others Claims.

The invention is advantageously used with a portable pager, but is not applicable to such limited, but can also be used in general for broadcast receivers. The receiver and the acoustic Horn are -as integrated elements in a rectangular

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Housing housed, which is divided into two compartments in the longitudinal direction. Has the wall separating the two compartments only one opening for the connection of the acoustic horn, which is formed in the second compartment, the acoustic horn is formed from a passage which changes hyperbolically with respect to its cross-sectional area. The exit opening of the home is on the upper face of the receiver, so that the sound waves directly device can be emitted to the ear of the user when the receiver is conventionally in a pocket or on a belt will be carried. The first compartment houses the receiver unit, which also includes the electro-acoustic Includes converter. Furthermore, an acoustic chamber is arranged in the first compartment, the outlet opening of which with the Communicates opening in the partition. This acoustic chamber, which is attached to the housing in the first compartment, has an inlet opening in a position which is opposite the exit opening of the transducer when the receiver part enters the first compartment is used. Um, a flawless transfer the sound! vibrations from the electro-acoustic To ensure transducer to the acoustic chamber, a flexible coupling element is interposed, which is connected to the inlet opening for the sound vibrations at the acoustic Chamber is attached. For the hyperbolic acoustic Horn, a shape is preferably used that has a primary resonance frequency at about 2000 Hz and a resonance frequency for the acoustic reflection at around 700 Hz. "Through these two resonances, the sound amplification properties of the horn are influenced that the horn has a very high efficiency and allows a significant reduction in volume. That way is a reduction in the size of the home is possible, so that it is no longer exclusively decisive for the housing size of the recipient is. It can thus achieve a volume reduction for recipients of this type that were previously not or

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is only possible with considerable financial outlay.

The features and further advantages of the invention emerge from the following description of an exemplary embodiment in conjunction with both per se and in any combination, the claims characterizing the invention and the drawing. Show it:

Fig. 1 is a perspective view of a portable paging · receiver according to the invention; ■ '■

Pig. Figure 2 is a section along lines A-A of Figure 1 showing the printed circuit board and components of the shows the receiver part removable from the housing;

3 shows a top view of the receiver part with a converter which can be mounted in the housing of the paging receiver according to FIG.

Fig. 4 is a perspective view of the housing of the pager according to Fig. -1 with a U-shaped front and rear cover, wherein the removable receiver part is removed;

Fig. 5 is a section through the housing along the line B-B of Fig. 4; .

Fig. 6 is a perspective view of the exploded Receiver housing, the back cover and the removable receiver part are removed and the one side wall is shown removed to release the acoustic horn for display;

Fig. 7 'is a view of the freed from the side wall Side of the housing according to FIG. 6;

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Fig. 8 is a perspective view of the in the housing according to Fig. 4- arranged acoustic chamber;

9 shows a perspective view of a coupling element;

Fig.IO is a perspective view of the transducer based on the printed circuit card according to FIG. 3 is arranged.

In Fig. 1, a call receiver is shown - in which the invention Is used. In a rectangular elongated housing 10, there are two elongated rectangular ones next to one another Compartments 11 and 12 are provided. In compartment 11, a self-contained receiver part is printed on a Circuit card arranged as a chassis, whereas the compartment 12 contains a hyperbolic acoustic horn. The compartments 11 and 12 are separated from one another by a partition 18, as can be seen from FIG. In a partition 13 is a Opening 14 is provided through which the switch 15 protrudes for operating the receiver. A second opening 17 in the front wall 13 represents the outlet opening of the hyperbolic acoustic home. This opening 17 is through a grating 16, which serves to keep dust and foreign bodies from entering the acoustic horn. on the rear of the compartment 11 of the housing 10 is a bracket 19, - with which the pager e.g. in the pocket of the user or attached to a belt.

In Figures 2 and 3, the portable receiver part is the pager shown. This receiver part is mounted on a printed circuit card -2-5 ', which is in the compartment 11 of the housing is housed. As already mentioned, the actuating part of the switch 15 protrudes on the printed circuit card through the opening 14 in the end wall 13 of the housing. On the printed circuit board 25 is next to the multitude

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of the elements 26 of the receiver part a battery 27 with the aid a holder 28 is mounted. This battery supplies the power supply for the pager. There is also a converter 29 on. the circuit card 25 attached, which converts the electrical modulation signals into acoustic vibrations, so that in the compartment 11 of the housing a complete receiver is housed.

The transducer 29, from which the outer housing 31 is removed, is. shown in Fig. 10. · The actual · -electro-acoustic The transducer element 35 is directly below an opening 36 arranged on the underside of the structure. The one from the electroacoustic Transducer element. 35 generated sound vibrations are passed on via a spiral passage 32 and occur through an opening 30 in the housing 31. These sound vibrations are transmitted via an acoustic coupling element 33 (see FIGS. 2 and 9) into an acoustic chamber 34, which is attached to the inner wall of the housing 10.

4 and 5, the arrangement of the acoustic Kammsr 34 in the housing ". This chamber 34 is in the area of the end wall 13 on the rear side 37 in the compartment 11 and attached to the inside of the partition wall 18. This acoustic chamber -34 has a first opening on the surface 38, in which the acoustic coupling element 33 is attached. This acoustic coupling element 33 preferably consists of a resilient cylindrical part with an outer wall and a through opening 41 axially through the cylindrical Coupling element runs. At the lower end there is an annular recess in the outer wall 40 of the coupling element 42 incised. When the coupling element is inserted into the acoustic chamber 34, the one formed by the top surface engages Edge of the opening -38 into the recess 42, with which the coupling element and the acoustic chamber connected to one another The coupling element -33- can be made of rubber or a

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synthetic material with properties similar to those of rubber.

As can be seen from Fig. 2, the outlet opening 30 of the The transducer 29 is arranged next to the opening 41 of the acoustic coupling element 33. When the printed circuit board 25 is inserted into the compartment 11, experiences the coupling element 33 undergoes elastic deformation and is pressed together, with the stems ei t-e 43 against the housing 31 of the Converter 29 comes to lie around the opening 30. The sound vibrations are transmitted from the transducer via the coupling element 33 29 transmitted through the opening 30 to the acoustic chamber 3 ^. Since the coupling element 33 is only resiliently pressed against the housing of the transducer 29, the removable receiver part can be easily removed from the housing 10 and reinserted, with a good acoustic connection to Chamber 34 is guaranteed. This makes it possible to use the printed Circuit card 25 and the entire receiver part can be removed from the housing in order to subject it to a test or repair, after which it can easily be put back into the housing can be used. It is also possible to operate the receiver part with different housings, each with a contain acoustic horn with different characteristics.

The from the electro-acoustic transducer element in the transducer 29 generated sound waves are with the help of the coupling element 33 transmitted through the opening 38 into the acoustic chamber 34. This acoustic chamber 34 has a spiral curve Line 43, which transmits the sound waves to the outlet-side opening 44 of the acoustic chamber 34. from From this opening 44, the sound waves are formed through an opening 45 in the partition wall 1θ which is hyperbolic acoustic horn in the compartment 12 according to FIGS. 6 and 7 supplied. The acoustic chamber 34 is used to adapt the

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Output of the transducer 29 to the acoustic horn and enables a separation of the two compartments 11 and 12.

In FIGS. 5, 6 and 7, the course of the hyperbolic acoustic homes shown in the compartment 12, which consists of a first section 50, which extends from an area in the Proximity of the end wall 13 to the opposite end wall 52 runs. A second section 51 extends from the end wall 52 to the end wall 13, the two sections 50 and 51 connected to one another by a curved section 53 · The illustration shows that the cross-section of the horn is progressively hyperbolic enlarged from opening 4-5. The through the opening 45 incoming sound vibrations meet a curved one Section 55 of the side wall 56 and are introduced from there into the first section 50. In the sections 50, 51 and 53 experience the sound vibrations a gain and pass through the opening 17 in the end wall 13 into the open. The hyperbolic horn in compartment 12 of a preferred one The embodiment is approximately 22 cm long. A horn of this kind has an initial acoustic resonance at about 700 Hz. As a result, the sound vibrations experience a Amplification - in the audio frequency range and in particular in the speech frequency range, so that the intensity of the through the opening 17 emerging sound vibrations and thus the volume is much larger than with conventional horns, the one have comparatively small physical dimensions. Since the opening 17 of the horn on the upper face 13 of the The paging receiver is attached, the exiting sound waves radiated in a direction favorable to the user and are therefore easily audible. ■

The preceding was a. transportable paging receiver described, which in its housing · an integrated acoustic horn - The receiver part is self-contained

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built and can be removed from the housing. This installation and removal of the receiver part is very easy without that for this purpose special mechanical connections between the receiver part and the acoustic horn have to be loosened, because an elastic coupling element is used. The acoustic horn has a very good efficiency due to its length, its hyperbolic chaiacterxstischen course and the resonance frequencies, whereby a better Sound amplification in comparison with sound amplifiers results in correspondingly smaller dimensions. By using an acoustic chamber between the horn and the coupling element is a good match on the one hand and on the other hand causes an isolation between the two compartments with different functions.

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Claims (1)

MO4-9P-919 Claims (l.j! portable paging receiver with an integrated acoustic - · Horn and a receiver part which can be removed from a rectangular housing and which is an electro-acoustic Comprises converter, characterized in that the housing (10) is divided into two by a partition (18) subdivided, side by side and longitudinally extending compartments (11, 12) is divided, wherein the first compartment (11) is provided for receiving the receiver part and / in the second compartment (12) as an acoustic one Horn trained and amplifying sound vibrations Passage (50, 51> 53) are formed, and that a acoustic chamber (34) is mounted in the first compartment, which the sound vibrations between the transducer (29) and transmits to the horn. 2a portable pager according to claim 1, characterized in that g e ■ k'en η shows that the electroacoustic Transducer and the acoustic chamber, which is in the area of the upper end face next to the partition are arranged, subsequent acoustic horn with a first section from the upper end face to runs into the area of the lower end face and there over a curved section into another Section passes that runs from the lower end face to the upper end face and into one in the upper one End face arranged opening opens, and that the 309830/0862 MCW-9P-919 Cross-section of the sections forming the horn approximately a hyperbolically enlarging cross-sectional area having. 3. Portable pager according to claim 2, characterized in that the acoustic horn is a has primary resonance frequency at about 2000 Hz, and that the resonance frequency of the acoustic reflection at is approximately 700 Hz. 4 ·. Portable paging receiver according to one or more of Claims 1 to 3, characterized in that that the acoustic chamber between an inlet opening and an outlet opening for the sound vibrations has a spiral-like passage widening in cross section, the outlet-side opening in a corresponding opening leading to the acoustic horn in the second compartment opens. 5- Portable pager according to one or more of the claims 1 to 4, characterized in that the coupling element has a through opening for the Has sound waves and is arranged between the transducer and the acoustic chamber that the Coupling element the removal of the receiver part with the transducer from the first compartment and easy separation of the transducer from the acoustic chamber. 6. Portable paging receiver according to claim 5 »thereby g e kenn, ze Ichnet that the coupling element consists of a resilient cylindrical part with an axial There is a through opening and in the area of one end edge has a circumferential recess in the outer wall, in which the edge of the opening of the acoustic chamber cut into the top surface can be used 309830/0862 MO49P / G-919 / 2O and so that the coupling element can be connected to the acoustic chamber, and that the through opening on the the other side of the coupling element above the exit opening for the sound waves on the acoustic transducer comes when the receiver part is inserted in the first compartment. 7- Portable pager according to claim 5 and 6, characterized marked that the coupling element is made Rubber or a correspondingly pliable synthetic material is made. 309830/0862 Blank page