Abstract: A speaker for the automotive audio system utilizes at least a part of a vehicle panel which constitutes a vehicle body independently of the speaker and adapted for oscillation at an audio frequency. The vehicle panel serving as a sound-producing medium comprises an inner section to be directly driven by a driver unit of the speaker and an outer section connected to the first section via a relatively flexible intermediate section. The relatively flexible intermediate section is adapted to transmit the audio frequency oscillation. The relatively flexible intermediate section serves for amplifying the magnitude of the audio frequency vibration of the vehicle panel and/or for expanding the audio frequency range to be reproduced. Especially, the relatively flexible intermediate section is adapted to improve reproduction of relatively low frequency range of audio sound.

Abstract: A driver unit for an audio speaker has a stationary component and a vibrating component associated with an automotive audio system and fixed to the vehicle panel. The stationary component is suspended from the vehicle body so that an electromagnetic section of the vibrating component is subject to a permanent magnetic field generated by the stationary component. A guide member is interposed between the stationary component and the vibrating component for guiding movement of the vibrating component in the axial direction. The guide member is adapted to restrict movement of the vibrating component in the direction perpendicular to the axial direction in order to prevent the vibrating component from being displaced laterally in relation to the permanent magnetic field.

Abstract: The driver of a speaker for an automotive audio system includes a plurality of magnetic coils wound around a common bobbin. Each of the magnetic coils is connected to one of a plurality of amplifiers each of which output an identical drive signal. By applying the common drive signal to each magnetic coil, the electromagnetic field created around the magnetic coil is enhanced approximately in proportion to the number of magnetic coils. Due to this increased electromagnetic force, a vehicle panel serving as a sound-amplifying medium can be satisfactorily and successfully driven so as to produce high-quality sound. The amplifiers are adapted to amplify the low-frequency components of the audio signal from a main amplifier.

Abstract: The hub section of a pointer is provided with first and second light reflecting curved surfaces which are arranged on opposite portions with respect to the axis of the spindle of the movement. The first light reflecting curved surface is formed on a part of walls defining a recess formed in the hub portion.

Abstract: A light guiding plate integral with a dial board proper of a transparent material is formed with a light reflecting surface which is such constructed that the light entering the light guiding plate from a top of the same is reflected by the light reflecting surface to be directed toward a portion, where the light guiding plate and the dial board proper are integrally connected, for focalization of the light in the vicinity of an opening of the dial board proper through which a spindle of a movement passes.