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Pioneer Electronic Corporation

Pioneer Electronics Corporation

Tohoku Pioneer Electronic Corporation

Tohoku Pioneer Electronics Corporation

Jiro Nakazono

Masatoshi Sato

Kunio Mitobe

Fumio Murayama

Kanya Matsumoto

Yoshitaka Kobayashi

Yukio Tsuchiya

Shigeru Watanabe

Akihiko Kodama

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. The process for forming the molded foam resin according to the present invention includes the steps of injecting a foaming agent-containing resin into a mold and opening the mold after a lapse of a designated period of time after the completion of the injection, in which a cavity of the mold contains a thick space corresponding to the foamed zone and a thin space corresponding to the non-foamed zone, and the designated period of time is chosen so that a curing of the resin filled into the thin space is completed and a curing of the resin filled into the thick space is not completed. Thus, a molded foam resin and a speaker diaphragm according to the present invention can be thinned, designed with different tone of color on surfaces thereof and lightened without deteriorating stiffness thereof.

Molded foam resin, process for forming the same and speaker diaphragm consisting of the same

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

Touch panel device

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.

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.

Loudspeaker

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.

Methods for making a loudspeaker vibrating diaphragm

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.

Loudspeaker vibrating diaphragm and methods for its production

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.

Growing community of inventors

Yamagata-ken, Japan

Jiro Nakazono