Key sheet, lightproof light guiding sheet, pushbutton switch, and method of manufacturing key sheet

摘要

The present invention provides technology that can efficiently guide light to the interior of a key sheet and prevents light from leaking from the circumferences of key tops. A key sheet has a light-shielding dark print layer, on the rear surface of a base sheet, that is a cured body of a coating liquid that is not dissolve to the surface of the base sheet, and also has a smooth surface between the base sheet and the dark print layer. The invention can make light transmitting in the base sheet hard to enter the dark print layer so that the light can be efficiently guided in the base sheet, and also can prevent light from transmitting through the base sheet by blocking the light.

主权项

1. A key sheet that includes a base sheet formed of a transparent resin film and a depressing operation portion formed on an operation surface side of the base sheet, the key sheet being illuminatable, wherein:
the base sheet is a light-guiding sheet; and a transparent resin layer is formed on a rear surface of the base sheet, the rear surface being opposite from the operation surface side, the transparent resin layer being made of a cured body of a coating liquid that does not dissolve to the surface of the base sheet, a dark print layer, which shields light, is further formed on a surface of the transparent resin layer, a smooth surface is provided between the base sheet and the dark print layer, and a diffusing part which includes a filling material is formed on the rear surface of the base sheet to direct light transmitting in a surface direction of the base sheet to the depressing operation portion, the diffusing part being formed on a front surface side of the dark print layer, the front surface side being facing the base sheet.