| 摘要 |
A control panel comprises a plate 2 to be positioned over the electronic LCD display (5 fig.2) such that at least a proportion of the electronic display is visible though the plate, a control knob 1 mounted to the plate; a light emitter 3 positioned to project light towards the control knob; a light detector 4 positioned to detect the light exiting the control knob, in which the control knob has a valve means so that the amount of the light that reaches the light detector changes when the control knob is moved. Preferably, as shown in figure 5 the valve means includes transparent 8 and non-transparent 9 members or have reflective and non-reflective members. The knob is rotatable and push operated. There may be more than one knob and a plurality of emitters and detectors as shown in fig.10. Preferably the knob can be controlled automatically via computer software and the knob is capable of displaying in formation projected onto its surface (21, fig.11) |
