1. Field of the Invention
This invention relates to a vehicle room lamp which is provided within a vehicle room (or compartment), and is switched between the ON-state (for illuminating the room) and the OFF-state by pressing a light-transmitting member such as a lens.
2. Related Art
An automobile is equipped with a vehicle room lamp (or interior lamp) so as to ensure that the passenger can comfortably get in and out of the automobile at night. For example in a passenger car, such a vehicle room lamp is usually mounted at a central portion of a ceiling of the passenger room (or compartment), and the whole of the passenger room is uniformly illuminated by light distributed by this lamp. The vehicle room lamp is so disposed that a switch can be operated both from a front seat side and a rear seat side. Generally, the switch can be located in any one of three positions, that is, an ON position, an OFF position and a DOOR ACTUATED position.
JP-A-2002-316579 Publication discloses a technical concept in which a push switch is turned on and off by a lens plate (which transmits light from a bulb therethrough in a spreading manner) such that the lens plate is used instead of a knob for operating the switch so as to turn on and off the bulb. With this construction, a box-like body can be formed into a compact size, and besides a vehicle room lamp with a novel design can be produced.
However, in such a conventional vehicle room lamp with the box-like body of a compact design as disclosed in Patent Literature 1 and others, a projection formed on a reverse surface of the lens plate is held against the push switch, and when the user presses the lens plate, the projection presses the push switch to switch the same so as to turn on and off the bulb. Therefore, light from the bulb is intercepted by this projection, and besides the thickness of the light-transmitting lens plate is increased because of the provision of the projection. Therefore, a shadow of the projection, etc., are formed on a design surface of the lens plate at the reverse side of the projection relative to the bulb, so that light and dark portions are formed on the illumination surface (i.e., the design surface) of the lens plate, and therefore it has been difficult for the illumination surface to become luminous uniformly over the entire area thereof.
It may be proposed to provide the switch and the projection at the outside of the lens plate. In this case, however, the box-like body, etc., of the vehicle room lamp increase in size, and this is not desirable because of a limited space available within the vehicle and for other reasons.