Mirror

The present invention relates to a mirror which also works as a light source or an image projector.

In ordinary vehicles, there are provided a rear view interior mirror, a room lamp and various display panels in the compartment to suffice various demands of the driver and the passengers. The dashboard is crowded with the display panels for giving various information to the driver and it is becoming difficult to find an extra space in the compartment for further information.

In the present invention, it is aimed to obtain a rear view interior mirror which works as an ordinary rear view mirror and also as a general light source or display panel. The main components of the present invention are a translucent thin reflecting film back on the transparent glass and an electroluminescence element secured next to the translucent thin reflecting film. When the element lights, the mirror works as a general light source or a display panel, since the light emitted projects through the translucent thin reflecting film. It maintains the function of an ordinary mirror when the electroluminenscence element does not light, since the light in circumstances enters into the mirror and partially reflected by the translucent reflecting film. Therefore the mirror, especially rear view interior mirror of this kind, is very useful in vehicles where no extra space for displaying information is available. Since the interior mirror is in the sight of the driver, it is very easy for him to perceive or read the information displayed on it. If it is designed that the whole mirror emits light, it may be used as a light source to read a book in the compartment. It may also be useful to apply the idea to the rear view exterior mirror. Although the primary purposes of the present invention is to suffice the need with respect to the vehicles, it is also applicable to other mirrors for other use than vehicles.

FIG. 1 is a partial cross-sectional view of an embodiment of the present invention, and,

FIG. 2 is a front view of the mirror of the present invention.

Numeral 1 in the drawing shows a transparent glass member forming a face of a rear view interior mirror. On the glass member 1 there is provided a thin reflecting aluminum film 2 of the thickness of about 50 angstroms to about 200 angstroms, preferably about 100 angstroms. In this embodiment the thickness is selected as about 130 angstroms. The aluminum thin film 2 is fixed to cover the glass member by the vacuum-deposition method. An electroluminescence element 3 is printed on the aluminum reflecting film 2 to cover the same and then fired. The electroluminescence element 3 is of planar plastic type whose components are zinc sulfide, copper and aluminum mixed with cyanoethylcellulose. In this case the element emits green light. To obtain blue light iodine powder must be added instead of aluminum. The thickness of the element 3 is in the order of about 40 microns. On the electroluminescence element 3 is there provided an electrode 4 which is of a conductive metal and has a thickness in the order of about 10 microns. A paste of silver is used as the electrode in this embodiment, which after printing is fired to cover the element 3. Although the electrode 4 can be fixed to the electroluminescence element 3 directly, it is possible and sometimes preferable to put an intervening insulation layer between the element 3 and the electrode 4 at the location indicated C. If the insulation layer is provided, the durability of the electroluminescence element is improved. In this case the insulation layer should be white so as not to make the layer conspicuous out of the reflecting thin film of aluminum 2. The insulation layer should be in the range of about 10 to 40 microns thick and of a mixture of barium titanate and cyanoethylcellulose.

The reflecting thin film of aluminum 2 of about 130 angstroms shows translucent characteristic against the incoming light and the electroluminescence element 3 has solid and nontransparent characteristic. Therefore when the light comes in and one looks from the direction of arrow A, it works as an ordinary mirror. On the other hand when the electroluminescence element 3 is energized via a couple of electrodes, the reflecting film 2 and the electrode 4, the light emitted by the element 3 passes through the thin film of aluminum 2 and the glass member 1, thereby playing a roll of plane light source to emit light into the direction of arrow B.

The mirror thus composed is fixed to a housing 5 so as to expose the face of the mirror into the compartment. The housing 5 is connected with a support member 7 via a joint 6, thereby to be mounted on the ceiling of a vehicle. Lead wires 8 and 9 which transmit electrical signals to the reflecting thin film of aluminum 2 and the electrode 4 are routed through the supporting member 7 to the body of the vehicle so as to be connected with a control circuit 10. The control circuit 10 is supplied with the power from a battery 12 upon a closure of the main switch 10A, and works when the command switch 11 is closed to produce and supply the required voltage to the element 3 to operate it.

When the electrode 4 is designed to cover the whole area of the mirror, the mirror works as a general light source. When the electrode 4 is designed and shaped to indicate a particular meaning such as the ones shown in FIG. 2, it works as a display panel when energized. Since the interior mirror is in the sight of the driver, it is very convenient and easily recognizable when it projects some cautionary marks or phases. In FIG. 2 numeral 1B shows portions illuminated while numeral 1A shows portions of ordinary mirror.

It is possible to select other materials than the ones disclosed for the reflecting thin film and the electroluminescence element. Also the electroluminescence element 3 may be vacuum-deposited on the reflecting thin film of aluminum 2 to obtain smaller and lighter mirror. It is also possible to shape the mark or letters by so shaping the electroluminescence element 3 itself instead of shaping the electrode 4 as above mentioned.