Furthermore, there are blank keys available which the user can use to form visible partitions or clusters of key tops on the programmable keyboard. When the user wants to make a group of keys on the programmable keyboard clearly separated from the rest part of the keyboard for certain specific application, he/she can use the blank keys to replace the normal individual keys around the area. The top surface of a blank key is at the ground level of the key stroke for other keys (ref. Fig.
There are also double key and quad key available for the user to configure the programmable keyboard such that the most frequently used keys may occupy larger areas. The double key occupies two “vertically” adjacent positions and uses only the bottom position for key content (ref. Fig.
An example of using the above mentioned alternate key tops is shown in Fig.
Fig. 3 - 2 | Fig. 3 - 3 | Fig. 3 - 4 |
protuberance
Springy wall
Fig. 3 - 5 | Fig. 3 - 6 |
3 - 3