WO2001086950A1

WO2001086950A1 - Display device with loudspeaker

Info

Publication number: WO2001086950A1
Application number: PCT/EP2001/004709
Authority: WO
Inventors: Virgilio Buccitti; Francesco Zacchia; Alessandro Bucci; Paolo Ginesti
Original assignee: Thomson Licensing S.A.
Priority date: 2000-05-05
Filing date: 2001-04-26
Publication date: 2001-11-15
Also published as: AU2001265904A1; IT1317459B1; ITMI20000978A1; ITMI20000978A0

Abstract

A display device includes a cabinet (2) carrying a screen and a lloudspeaker (4). A first part (16, 20) made of a first material is attached to one of said cabinet (2) and said loudspeaker (4); a second part (18) is attached to the other one of said cabinet (2) and said loudspeaker (4). The second part (18) is made of a second material with higher elasticity than the first material. The second part (18) is engaged with the first part (16, 20) with deformation in order to be attached to the first part (16, 20).

Description

DISPLAY DEVICE WITH LOUDSPEAKER

The invention relates to display devices and to loudspeakers which can be mounted on display devices.

A display device comprises a cabinet which forms its external housing. The cabinet carries a screen which is the optically active part of the display device. Such a screen can be implemented for instance by a cathode ray tube (CRT). Nowadays, other types of screen are well-known, though not so widely used, like for instance liquid crystal displays (LCD's) and plasma panels.

As conventional, the display device also includes one or a plurality of loudspeaker(s). Each loudspeaker is mounted to the cabinet. As they generate sound, the loudspeakers are inevitably a source of vibrations, which may be transmitted to the cabinet, and therefore to the screen, if specific means are not provided to dampen these vibrations.

Transmission of the vibrations to the screen would cause problems to the display ; when using a CRT in a colour TV, these problems are due mainly to the vibrations of the mask and known as howling phenomenon.

An attempt to solve the above problem is described in U.S. Patent No. 5,956,412. This patent document proposes to use a loudspeaker case structure having a housing, whereon the loudspeaker is mounted by means of screws, and a supporting section notably including an elastic absorbing rib portion. The loudspeaker case structure is mounted on a main bracket of the cabinet by means of screws. This solution allows reduction of vibrations transmission from the loudspeaker to the cabinet but suffers some drawbacks. At first sight, it is space-consuming ; furthermore, as the loudspeaker case structure is made of only one part which on the one hand has to receive screws and on the other hand has to form an elastic absorbing rib, the part has a very complicated design which is difficult and expensive to realise, even for slight dampening of the vibrations.

The invention aims at mounting a loudspeaker on a cabinet in a display device with great reduction of the transmission of vibrations generated by the loudspeaker by a simple construction. It is also an object of the invention to provide ease of assembly of the display device, notably in order to simplify the manufacturing process.

The invention proposes a display device comprising a cabinet carrying a screen and a loudspeaker, a first part made of a first material being attached to one of said cabinet and said loudspeaker, a second part being attached to the other one of said cabinet and said loudspeaker, wherein the second part is made of a second material with higher elasticity than the first material and wherein the second part is engaged with the first part with deformation in order to be attached to the first part. According to further features of the invention :

- the first part has a hollowing-out, the second part has a pad and the pad is inserted in the hollowing-out ;

- the loudspeaker is mounted on the cabinet through a horn ;

- the horn has a flange through which the horn is mounted on the cabinet ;

- the first material is rubber ;

- the second material is polyvinyl chloride.

The invention thus also proposes a loudspeaker to be mounted on a cabinet, with a first part made of a first material to be attached to one of said cabinet and said loudspeaker, a second part to be attached to the other one of said cabinet and said loudspeaker, wherein the second part is made of a second material with higher elasticity than the first material and wherein the second part is engaged with the first part with deformation in order to be attached to the first part. The invention and other features thereof will be better understood in the light of the following description made with reference to the attached drawings where :

- figure 1 is a side view of an embodiment of the invention ;

- figure 2 is a top view of the embodiment of figure 1 ; - figure 3 is a cross section of a front foot according to the invention ;

- figure 4 is a cross section of a rear foot according to the invention ;

- figure 5 is a cross section of a damper according to the invention. The general structure of a display device is the following : a screen is affixed to the front face of a cabinet, so as to be visible through a front opening of the cabinet ; loudspeakers are also mounted to the cabinet, either directly or through a horn. Such a general structure is described for instance in patent applications WO 89/1 1198 and EP 0 440 551.

In the embodiment described below, the loudspeaker 4 is mounted to the cabinet 2 through a horn 6 which is represented on figures 1 and 2. The horn 6 is an air duct extending axially in the direction X of propagation of the sound, that is essentially perpendicularly to the membrane of the loudspeaker 4. This axial direction X is also the mouting direction of the loudspeaker 4 on the horn 6 and of the horn 6 on the cabinet 2, perpendicularly to the surface of the cabinet 2 receiving the horn 6. The horn 6 comprises a front portion 8 and rear portion 10 which communicate with each other. The front portion 8 is situated next to the cabinet 2 and the loudspeaker 4 is mounted to the rear portion 10. A flange 12 extends laterally in the region where the front portion 8 and the rear portion 10 connect. Supporting devices 14 are provided between the flange 12 and the cabinet 2 in order to fix the horn 6 to the cabinet 2. In the embodiment represented on the attached figures, two supporting devices 14 are provided.

Each supporting device 14 comprises a front foot 16, a damper 18 and a rear foot 20.

The front foot 16 is mounted to the cabinet 2 by means of a screw, possibly with interposition of an elastic ring. The front foot 16 is thus a part which is attached to the cabinet 2.

As can be seen from figure 3, the front foot 16 is cylindrical with an axis X' parallel to the axis X of the horn 6. In its front region, the front foot 16 has a screw hole 22 extending axially for receiving said screw. In its rear region, the front foot 16 has a cylindrical hollowing-out 24 extending axially on the same axis X' as the screw hole 22 and coming out in a face of the front foot 16 opposite the screw hole 22.

The rear foot 20 is mounted to the flange 12 by means of a screw, possibly with interposition of an elastic ring. The rear foot 20 is thus a part which is attached to the loudspeaker 4 (via the horn 6).

As can be seen from figure 4, the rear foot 20 is cylindrical, with its on the axis X' of the front foot 16. In its rear region, the rear foot 20 has a screw hole 26 extending axially for receiving said screw. In its front region, the rear foot 20 has a cylindrical hollowing-out 28 extending axially on the same axis as the screw hole 26 and coming out in a face of the rear foot 20 opposite the screw hole 28.

The front foot 16 and the rear foot 20 are made of a hard or relatively hard material, preferably of plastic material, like polyvinyl chloride (PVC). The elasticity of the used PVC is 3 000 N/mm² (and generally speaking it is more than 2 000 N/mm² which ranks it amongst the rigid materials). It is to be noted that the material of the front foot 16 could be different from the material of the rear foot 20. As can be seen from figure 5, the damper 18 is cylindrical with the same axis as the front foot 16 and the rear foot 20. The damper 18 is made of an elastic material (or at least relatively elastic compared to the front foot 16 and to the rear foot 20), like rubber. In its central portion, the damper 18 has a lateral extension 30. The extension 30 is also cylindrical with a diameter about the same as the diameter of the front foot 16 and the rear foot 20. Between each axial end and the extension 30, the damper 18 thus defines respectively a front pad 32 and a rear pad 34.

The diameter of the front pad 32 and the diameter of the rear pad 34 are slightly larger respectively than the hollowing-out 24 of the front foot 16 and than the hollowing-out 28 of the rear foot 20. For instance, for a hollowing-out 24,28 diameter of 12 mm, the pad 32,34 diameter is 12.2 mm.

The front pad 32 is inserted in the hollowing-out 24 of the front foot 16 and the rear pad 34 is inserted in the hollowing-out 28 of the rear foot 20, until the extension abuts the corresponding foot 16, 20. Thanks to the difference in diameters between pad 32, 34 and hollowing-out 24, 28, each pad 32, 34 is compressed when it is inserted in the corresponding hollowing-out 24, 28. The then-generated radial forces associated with the friction of the pad on the hollowing-out allow retention of the pad 32, 34 in the corresponding hollowing-out 24, 28. The link of the rear foot 20 and the front foot 16 via an elastic damper 18 as described above allows efficient dampening of the vibration between the rear foot 20 (attached to the loudspeaker 4 via the horn 6) and the front foot (attached to the cabinet 2).

It should be noted that the elasticity of the damper 18 allows at the same time vibration dampening and retention of the damper 18. The assembly of the loudspeaker 4 (and horn 6) to the cabinet 2 is very easy. After providing the cabinet 2 with the front foot 16 and the loudspeaker 4 with the rear foot 20, only a movement of the loudspeaker 4 with respect to the cabinet 2, in the axial direction X, with interposition of the damper 18, is needed.

The invention is not limited to the embodiment described above. Notably, the invention also applies when the loudspeaker is not provided with a horn, but is mounted to the cabinet, via the damper only.

It is also possible that the front foot and the rear foot be integral with respectively the cabinet and the horn (or loudspeaker).

Still another possibility is that the mounting of the damper on the feet be opposite, i.e. that the feet be inserted in a rubber tube implementing the damper.

Claims

1. Display device comprising a cabinet carrying a screen and a loudspeaker, a first part made of a first material being attached to one of said cabinet and said loudspeaker, a second part being attached to the other one of said cabinet and said loudspeaker, characterised in that the second part is made of a second material with higher elasticity than the first material and in that the second part is engaged with the first part with deformation in order to be attached to the first part.

2. Display device according to claim 1 , wherein the first part has a hollowing-out, wherein the second part has a pad and wherein the pad is inserted in the hollowing-out.

3. Display device according to claim 1 , wherein the loudspeaker is mounted on the cabinet through a horn.

4. Display device according to claim 3, wherein the horn has a flange through which the horn is mounted on the cabinet.

5. Display device according to claim 1 , wherein the first material is rubber.

6. Display device according to claim 1 or 5, wherein the second material is polyvinyl chloride.

7. Loudspeaker to be mounted on a cabinet, with a first part made of a first material to be attached to one of said cabinet and said loudspeaker, a second part to be attached to the other one of said cabinet and said loudspeaker, characterised in that the second part is made of a second material with higher elasticity than the first material and in that the second part is engaged with the first part with deformation in order to be attached to the first part.