Memory erase and memory read-out in an EL display panel controlled by an electron beam

A drive system for reading out information written on a thin-film EL element including a thin-film EL layer sandwiched between a pair of electrodes, said drive system comprising:

• means for applying a voltage signal between said pair of electrodes;
• means for applying an electron beam to said thin-film EL element through one of said pair of electrodes;
• control means for applying said electron beam to a desired position on said thin-film EL element at a time when said voltage signal level is substantially zero;
• and
• detection means for detecting an electric current flowing through said thin-film EL layer when said electron beam is applied to said thin film EL element, thereby reading out information written on said EL current.

A drive system for a thin-film EL element including a thin-film El layer sandwiched between a pair of dielectric layers and a pair of electrodes formed on both dielectric layers, said thin-film EL element exhibiting the hysteresis memory function for storing information, said drive system comprising:

• means for generating an electron beam toward said thin-film EL element;
• means for deflecting said electron beam in order to apply said electron beam to a desired position on said thin-film EL element;
• means for applying an alternating sustaining voltage signal between said pair of electrodes;
• means for applying a read-out voltage signal between said pair of electrodes, said read-out voltage signal having an amplitude substantially identical with that of the alternating sustaining voltage signal, and said read-out voltage signal having a leading edge of a predetermined inclination;
• and
• means for detecting an electric current flowing through said thin-film EL element at a time when said read-out voltage signal is applied between said pair of electrodes, whereby the stored information is recovered.

A drive system for erasing information written on a thin-film EL element including a thin-film EL layer sandwiched between a pair of electrodes, said drive system comprising:

• means for applying an alternating sustaining voltage signal between said pair of electrodes;
• means for applying an electron beam to said thin-film EL element through one of said pair of electrodes;
• and
• control means for applying said electron beam to a desired position on said thin-film EL element at a time when said voltage signal is at a level which will not excite the thin-film EL element thereby erasing information from said EL element.

A drive system for reading-out information written on a thin-film EL element including a thin-film EL layer sandwiched between a pair of electrodes, said drive system comprising:

• means for applying an alternating sustaining voltage signal between said pair of electrodes;
• means for applying an electron beam to said thin-film EL element through one of said pair of electrodes;
• control meansfor applying said electron beam to a desired position on said thin-film EL element at a time when said voltage signal level is substantially zero;
• and
• detection means for detecting an electric current flowing through said thin-film EL layer when said electron beam is applied to said thin-film EL element, thereby reading out information written on said EL element.