Techniques for providing a common input for multiple users are disclosed. The dial face has an opaque portion and defines a shaft aperture. The frit seal having flowability less than the frit seal applied to the pin electrode is applied to the end of the front panel and the side face of the rear panel. The weather strip is held down not at a fitting section but also at the extension section and the protrusion section. The processing unit is programmed to acquire a sequence of images framed by the camera, to detect when the user has stopped on the text, to recognize at least one word which the user intends reading, and to reproduce the sound of said at least one word by means of vocal synthesis by means of the vocal reproduction device.