| 摘要 |
<p>Two waveform traces to be simultaneously displayed are sampled and converted to a series of digital samples values. An electro-optic display (1), e.g. a liquid crystal or electro luminescent display has a first m set and a second n set of electrodes arranged in a matrix having m x n display elements. The matrix may be in cartesian XY or ⊖ polar co-ordinate format. In one form the m set of electrodes are arranged in two sub sets alternating with one another forming a sub set m<Sub>o</Sub> of odd rows and a sub set m<Sub>e</Sub> of even rows. Coded waveforms V,, each having a different shape over a period T are applied to one sub set m<Sub>o</Sub> of the m electrodes whilst another voltage is applied to the other subset m<Sub>e</Sub> of m electrodes followed by application of V<Sub>i</Sub> to the sub set m<Sub>e</Sub> and the other voltage to sub set m<Sub>o</Sub>. Selected ones of the coded waveform V<Sub>i</Sub> are generated and applied to the n electrodes, the choice of such selectively produced waveforms being related for each successive n electrode to successive sample values of the two traces and the order of coded waveforms on the m set of electrodes. As a result traces are displayed at interesections where the same waveform occurs periodically and simultaneously.</p><p>The coded waveforms V<Sub>i</Sub> applied to the m electrodes may be produced by a pseudo random generator (24, 25). The selected ones of the coded waveforms V<Sub>i</Sub> applied to the n electrodes may be produced by a read only memory (50) supplied with trace sample values stored in a random access memory (28).</p><p>A priority encoder (36, 38 to 46) modifies each sample value of the traces as necessary to ensure that two values for any given n electrode do not appear on the same subset of m electrodes.</p> |
