| 摘要 |
Keyboard (20) having a plurality of keys (12, 14, 16) thereon at least one of which is designated as a critical function key (16), wherein each key is movable from a home position along an actuation path to its operated position and has means (24) for restoring it towards its home position. In prior art keyboards of this kind important data may be lost by accidental actuation of a critical function key, e.g. a "Delete" key. The present invention overcomes this problem by providing a keyboard in which a critical function key (16) has a warning member (40, 60) associated therewith which causes the force required to move the key to its operated position to be significantly greater than that required to move each of the other keys not having a warning member associated therewith. The increase in force provides tactile feedback to an operator of the keyboard before the critical function key's operated position is reached to thereby warn said operator that he is about to operate the key (16). In one embodiment, the warning member (40, 60) is made of resilient material, has a generally washer-like shape, and is positioned around the key stem (18) and under the key cap (26) of the critical function key (16). |
