Electrostatic image display apparatus

An electrostatic image display apparatus comprising:

• (a) a housing;
• (b) electrode means in the housing, supported by a substrate;
• (c) a layer of transparent piezoelectric film parallel to, and separated a distance from, the electrode means, said piezoelectric film having a protective transparent metallic coating on its outer surface and being supported by transparent semi-rigid support means on its inner surface, arranged such that localized pressure on said layer will product localized electrical charges on said layer;
• (d) a suspension medium between the electrode means and the piezoelectric film, the medium containing electrically charged pigmented particles free to move toward said localized electrical charges;
• (e) an opening in the housing whereby said localized pressure may be applied to said piezoelectric film;
• and
• (f) user-actuatable switch means for selectably energizing the electrode means to a preselected electric potential in order to cause said pigmented particles to be removed from said piezoelectric film.

An electrostatic image display apparatus comprising:

• (a) a housing having a base, sides and a top;
• (b) an electrode supported in the housing by a substrate, the electrode being connected to a selectably operable switch for switching the electrode between a ground potential and a non-zero potential, and a means for energizing the electrode to a non-zero potential;
• (c) a layer of transparent piezoelectric film comprising an inner surface and an outer surface, said piezoelectric film being parallel to and separated a distance from the electrode means, and having a protective transparent metallic coating on the outer surface and a transparent semi-rigid support means on its inner surface, arranged such that localized pressure on said layer will produce localized electrical charges on said layer;
• (d) a suspension medium containing electrically charged pigmented particles, said particles being of a color which contrasts with the color of the suspension medium, said suspension medium being located between and in face contact with the electrode means and the inner surface of the piezoelectric film, said particles free to move towards said localized electrical charges;
• (e) the housing top having an opening whereby said localized pressure may be applied to said piezoelectric film;
• and
• (f) means for selectably applying a localized force to selected portions of the piezoelectric film, said means comprising a stylus movably attached to the housing.