Constrained non-negative matrix factorization for multiline addressing schemes of quick-response liquid powder display

A quick-response liquid powder display (QR-LPD) is a favorable candidate for flexible electronic papers because it can be simply operated by passive-matrix driving. However, the slow image refreshing rate is its major problem. In this study, multiline addressing (MLA) schemes for QR-LPD have been developed for improving the driving efficiency. Non-negative matrix factorization (NMF) with boundary constraints is used for the MLA scheme. A hybrid pulse modulation (HPM) is proposed for further shortening the driving waveform. The experimental results reveal that the MLA using NMF produces a noisy image on QR-LPD. The root cause for this is that NMF is a linear factorization but the electro-optical response of QR-LPD is not a linear curve. Therefore, we have proposed a lossless matrix factorization (LMF) method. The MLA scheme using LMF not only improves the image refreshing rate but also shows images without loss.

► MLA improves the image refresh rate of QR-LPD compared with conventional addressing.
► Two algorithms of NMF and LMF are proposed to achieve the MLA.
► The HPM with the MLA is proposed to further shorten the driving waveform.