Patent ID: 7817213

Claim:
A driving apparatus for a liquid crystal device, the driving apparatus for recording an image onto the liquid crystal device, the liquid crystal device including at least a liquid crystal layer containing a cholesteric liquid crystal, a photoconductor layer, wherein the liquid crystal layer and the photoconductor layer are laminated, and electrodes disposed outside the liquid crystal layer and the photoconductor layer, the driving apparatus at least comprising: a power source device configured to apply a voltage between the electrodes; an exposure device configured to expose the liquid crystal device while scanning the liquid crystal device; and a controller configured to control the power source device and the exposure device by performing, in order, (i) an initialization action of initializing the entire liquid crystal layer into a focal conic state by causing the power source device to apply a voltage that exceeds a threshold value for a state change of the liquid crystal layer from a planer state to the focal conic state, (ii) a write action of writing the image onto the liquid crystal device by causing the exposure device to scan with selecting exposure or non-exposure while causing the power source device to apply a voltage, the voltage that does not exceed a threshold value for a state change of the liquid crystal layer from the focal conic state to a homeotropic state during the non-exposure but exceeds the threshold value during the exposure, the voltage that causes the focal conic state and the homeotropic state to be bi-stable after the exposure, and (iii) a display determination action of stopping the power source device to apply the voltage, to change a state of a portion, of which the state has changed to the homeotropic state, to the planer state, wherein in the write action, the controller controls at least the power source device and the exposure device so that an electric field energy applied to an exposure portion of the liquid crystal layer gradually increases from a start of a series of scanning actions to an end of the series of scanning actions.