Abstract: A molded foam resin, surface of which can be designed easily at low cost, a process for forming a molded foam resin, and a speaker diaphragm made of molded foam resin are provided, in which a molded foam resin is formed by injection molding of foaming agent-containing resin and has a foamed zone having a three layer-structure consisting of a foamed layer inside and a non-foamed layer outside and a non-foamed zone having a single layer-structure consisting of a non-foamed layer.

Abstract: There are provided microphones 11A, 11B arranged at least any two different locations of edge portions of a touch panel 10, for sensing a ultrasonic signal propagated through a space, an input pen 12 containing a piezoelectric loudspeaker 12G, for oscillating a ultrasonic wave that is output from the piezoelectric loudspeaker 12G, and a touch position sensor 13 for calculating a coordinate of a touch position P by calculating distances between the microphones 11A, 11B and the touch position P of the input pen 12 on the touch panel 10 based on the ultrasonic wave sensed by the microphones 11A, 11B, whereby the microphones 11A, 11B have a sound collecting directivity characteristic in response to fitted positions of the edge portions of the touch panel 10.

Abstract: An input pen has an oscillator and a piezoelectric loudspeaker, a frequency/output-level setting circuit for setting a frequency or an output level of a ultrasonic wave oscillated from the oscillator, and a touch sensor for changing a set value of the frequency/output-level setting circuit. A touch panel device comprises microphones for sensing the frequency or the output level of the ultrasonic wave oscillated from the oscillator of the input pen at a touch position on a touch panel by the input pen; a microcomputer for setting attributes of input information in response to the frequency or the output level of the ultrasonic wave sensed by the microphones; and a PDP displaying device for displaying the input information on the flat display device based on the set attributes.

Abstract: A loudspeaker has a cylindrical frame, a magnetic circuit formed on the frame, a voice coil disposed in a magnetic gap of the magnetic circuit, a diaphragm. A damper is attached to the frame and supports the voice coil. Leads are connected to both ends of the voice coil. The leads are attached to the damper by stitching.

Abstract: A molded foam resin, surface of which can be designed easily at low cost, a process for forming a molded foam resin, and a speaker diaphragm made of molded foam resin are provided, in which a molded foam resin is formed by injection molding of foaming agent-containing resin and has a foamed zone having a three layer-structure consisting of a foamed layer inside and a non-foamed layer outside and a non-foamed zone having a single layer-structure consisting of a non-foamed layer.

Abstract: A molded foam resin, surface of which can be designed easily at low cost, a process for forming a molded foam resin, and a speaker diaphragm made of molded foam resin are provided, in which a molded foam resin is formed by injection molding of foaming agent-containing resin and has a foamed zone having a three layer-structure consisting of a foamed layer inside and a non-foamed layer outside and a non-foamed zone having a single layer-structure consisting of a non-foamed layer.

Abstract: A method of producing a loudspeaker vibrating diaphragm comprising the steps of injecting an amount of resin containing a foaming agent into a metallic mold of an injection molding machine, the mold including a fixed part and a movable part, reducing a mold pressing force of the injection molding machine upon completion of the resin injection, so as to enlarge a space formed between the fixed part and the movable part by a predetermined distance, so that the foaming agent is foamed to obtain a foam layer in the diaphgram.

Abstract: A loudspeaker vibrating diaphragm with has a foam layer and two un-foamed skin layers formed on both sides of the foam layer. The average foaming magnification including the foam layer and two un-foamed skin layers is 1.1-3.0. The average foaming magnification is the ratio of the thickness of the resin after foaming (which equals the sum of the thicknesses of the foamed layer and the two un-foamed layers) to the thickness of the resin before foaming. The foam layer contains foaming bubble cells which are formed with their longer axes arranged in the thickness direction of the diaphragm. The thickness of each un-foamed skin layer is 0.05-0.20 mm.

Abstract: A driver unit for a horn type loudspeaker is disclosed. The driver unit comprises a dome-shaped diaphragm and an equalizer positioned on the concave side of the diaphragm. The equalizer has a convex surface adjacent the diaphragm and a plurality of slits extending from the convex surface to an interior, outwardly opening throat. The slits are disposed in equal angular pitch with the outermost slits being located at the edge of the convex surface of the equalizer. The outermost slits are approximately one half the width of the remaining slits, the remaining slits being of equal width.