PURPOSE: To uniform the brightness by constituting a base material sheet which contains a light diffusing agent by using a sheet material which emits dark light by the projection of reflected light and emits light by the projection of transmissive light and making a display on the surface of this base material sheet with a partial mask part which interrupts a part of the transmissive light.
CONSTITUTION: The base material sheet 1 is made of the sheet material which contains the light diffusing agent and is colored in dark color, e.g., black to maintain the dark color when the reflected light is projected in a nonillumination state, but transmit and emit the transmissive light when the transmissive light is projected on an illumination state. Further, the mask part 2 for displaying which is provided on one surface of the base material sheet 1 is constituted by printing the reverse surface of the base material sheet 1 with light shielding ink except characters A, B, and C. Then when a lamp 4 is turned on, the parts which are not provided with the mask part 2, i.e., display 3 is lighted clearly and viewed; when the lamp 4 is turned off, there is no transmissive light, the display 3 is not recognized, and the dark color surface is left. Consequently, the brightness at the time of the illumination is uniformed.
MATSUSHITA HIROSHI
SAITO SHOZO
