A key
encoder input module for keyboard which transmitting
signal with light, and the cost of manufacture is low. The key
encoder input module includes circuit controller, keycap which setup on casingand connected with
elastomer, multiple
signal emitters and receivers. The key
encoder input module also includes a light splitter, a key
optical switch is set under the keycap,
signal sent by the signal emitter corresponds to the light input port of the light splitters through
key light switch, a light encoder is formed between the light splitters and receivers by connecting them with the light path of the light splitters. When a keycap is pressed, signal emitter conducts with the light path of
receiver and forms light splitting path after passing the
key light switch and light splitter whichperforming permutation and combination to light path, and light encoder outputs a set of key code signal corresponding to the key position of the keycaps to the input circuit controller. The key encoder input module has the advantages of that the configuration is simple, the cost is basically equal to the traditional keyboard, and the number of photocells used is small. For example, the computerkeyboard usually needs a phototranslating circuit with 5 sets of receivers, and produces 2<5>key codes, namely 32 sets of key codes. And the
receiver does not need to directly correspond to
light switch of keys in rows. The phototranslating circuit including receivers may be set on the same printed plate with emitters and main control
chip. The key encoder input module has the advantages that theconfiguration of circuit is tight and simple, the cost of production is low, and it is easy to organize
batch production. It is convenient to take steps to pressurize a bit of printed plate, so that the keyboard is wholly rainproof, even may be used in water.