Development of Direct-Vibration Actuator for Bezel-Less Display Panels on Mobile Phones

Abstract

With the development of technology, multimedia devices such as smartphones, tablets, and wearable devices have become necessities in our lives, and many new products are introduced every year. Companies are expanding smartphone displays and are developing bezel-less display panel designs. The enlarged display limits the space available for a speaker, and a new actuator must therefore be developed. Indirect-vibration actuators were developed for full-wide display designs. Using the same sound-generation principle as that of the indirect-vibration actuator, the mechanism and design of the direct-vibrating actuator is proposed in this paper. Using 3D finite element method (FEM), the force factor is obtained and used for design optimization. A sample is produced, and an experiment is conducted for sound pressure level (SPL) comparison. The experiment results show that the newly designed direct-vibration actuator can replace the dynamic receiver in mobile devices and enable the application of the bezel-less display design.

Fabrication of practical deformable displays: advances and challenges

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Design and Analysis of a Novel Microspeaker with Enhanced Low-Frequency SPL and Size Reduction

“…However, this type of speaker is not widely adopted, owing to its high cost and poor acoustic performance at low frequencies. For a smartphone with a bezel-less display, indirect-and direct-vibration actuators were introduced and analyzed [8,9]. Compared with a microspeaker that generates sound by vibrating the diaphragm attached to the coil, these actuators are attached to the display panel, which generates sound by vibrating the elastic display panel.…”