Patent ID: 8884897

Claim:
A touch panel device, comprising: a touch panel; a display unit disposed on a rear side of the touch panel so that the touch panel is above the display unit as seen from a side of a user; a transparent protective substrate disposed on a front side of the touch panel so that the transparent protective substrate is above the touch panel as seen from the side of the user, the protective substrate being configured by joining a first glass substrate residing on a front side and a second glass substrate residing on a touch panel side, wherein either one of the first and second glass substrates is configured to have one or more stepped portions formed either on a rear surface of the first glass substrate or a front surface of the second glass substrate, the rear surface of the first glass substrate and the front surface of the second glass substrate fixed side by side facing one another so that said one or more stepped portions are embedded in the transparent protective substrate; one or more piezo vibration elements each disposed within one of the stepped portions in the transparent protective substrate so as to be acoustically coupled with the first glass substrate of the transparent protective substrate, the one or more piezo vibration elements thereby being disposed in the transparent protective substrate, wherein each of said one or more stepped portions is configured thicker than the corresponding piezo vibration element.