Key structure

A key structure, comprising:

• a polyester film having two first limiting units and two second limiting units disposed on the polyester film;
• a keycap having two third limiting units and two fourth limiting units disposed under the keycap;
• a scissor component comprising a first supporter and a second supporter, wherein the first supporter is connected to the first limiting units and the third limiting units, the second supporter is connected to the second limiting units and the fourth limiting units, and the keycap is connected to the polyester film through the first supporter and the second supporter of the scissor component;
• an elastomer disposed on the polyester film and configured to support the keycap;
• a circuit board disposed under the polyester film;
• an optical switch disposed on the circuit board, wherein the optical switch comprises an emitter and a receiver;
• and
• a shading portion disposed on the first supporter or the second supporter to block a light signal transmitted between the emitter and the receiver.