Abstract: A display panel device includes a display panel having a sensor sensitive to light, sound, heat and so on and a recorder/playback combination attached thereto. As an object transparent to or shielding light and generating sound or heat approaches the panel, the sensor is automatically actuated to give an automatic actuation to the recorder/playback combination, thereby reproducing music or sound from the surface of the display panel.

Abstract: A speaker system includes a thin plate type vibrating element mounted in, and brought into contact with, a balloon formed of a synthetic rubber or resin film. The balloon comprises a balloon member formed of a flexible film such as a vinyl chloride resin or synthetic rubber film and having therein a pocket, in which an inner film forming the pocket has an area somewhat larger than that surrounded with a laminating line on an outer film forming the pocket, whereby the inner film is brought in pressure contact or engagement with the outer film, when the balloon assembly is inflated.