| 摘要 |
1. A display screen (32) having a t light reflective or light emitting surface, characterised in that the screen comprises a member (2) having capability to sustain and propagate input vibrational energy by bending waves in at least one operative area extending transversely of thickness to have resonant mode vibration components distributed over said at least one area and have predetermined preferential locations or sites within said area for transducer means and having a transducer (9) mounted wholly and exclusively on said member at one of said locations or sites to vibrate the member to cause it to resonate forming an acoustic radiator which provides an acoustic output when resonating. 2. A display screen according to Claim 1, characterised in that the radiator (2) comprises a stiff lightweight panel having a cellular core (22) sandwiched between a pair of high modulus skins (21). 3. A display screen according to Claim 2, characterised by a frame (11) surrounding the panel. 4. A display screen according to Claim 3, characterised by a resilient suspension (3) mounting the panel in the frame. 5. A display screen according to any one of Claim 2 to 4, characterised in that the cellular core (22) is of honeycomb aluminium foil (98). 6. A display screen according to any one of Claims 2 to 5, characterised in that the skins (21) are of fibre reinforced plastics. 7. A display screen according to any preceding Claim 3, characterised by panel-form loudspeakers (114) attached to opposite sides of the frame (1) to provide left and right hand channel information. 8. A display screen according to Claim 1, characterised in that the left and right hand loudspeakers (114) are hinged on the frame (1) to be foldable against the screen. 9. A display screen according to Claim 7 or Claim 8, characterised in that the left and right hand loudspeakers (114) each comprise a member (2) having capability to sustain and propagate input vibrational energy by bending waves in at least one operative area extending transversely of thickness to have resonant mode vibration components distributed over said at least one area and have predetermined preferential locations or sites within said area for transducer means and having a transducer (9) mounted wholly and exclusively on said member at one of said locations or sites to vibrate the member to cause it to resonate forming an acoustic radiator which provides an acoustic output when resonating. 10. A display screen according to any preceding Claim, characterised in that the screen (2) is a projection screen. 11. Audio visual apparatus characterised by a projection screen (32) as claimed in Claim 10. 12 Audio visual apparatus according to Claim 11, characterised by at least one rear channel loudspeaker comprising a member (2) having capability to sustain and propagate input vibrational energy by bending waves in at least one operative area extending transversely of thickness to have resonant mode vibration components distributed over said at least one area and have predetermined preferential locations or sites within said area for transducer means and having a transducer (9) mounted wholly and exclusively on said member at one of said locations or sites to vibrate the member to cause it to resonate forming an acoustic radiator which provides an acoustic output when resonating. |
