| 摘要 |
<p>Data stored on a remotely-located storage sheet (29, 30, 31) which may, for example, be a sheet of a spare-parts manual used in the motor trade, can be updated by transmitting a signal from a central station (20) to a receiver (21, 22, 23) at the remote location. The storage sheet may be in the form of a microfiche. The invention is preferably put into effect by using a liquid crystal storage device as the storage sheet, which device can be updated by light from a simple laser printer, an imaging array, or a CRT screen at the remote location, operated by the transmitted signal. This avoids the need to replace storage sheets when updating is necessary. The storage sheet may comprise two electrically conductive layers (2, 6) between which are disposed a layer of a liquid crystal storage material (5) and a photoconductive layer (3). The liquid crystal material may be, for example, a liquid crystal polymer or a glassy nematic liquid crystal material.</p> |
