Abstract A solid-state energy-responsive luminescent device comprising an electro-luminescent element which is excited by AC voltage and has been endowed with resistivity and a photoconductive element whose photoconductive sensitivity is controlled by superimposing a DC voltage on the AC operating voltage; an AC voltage and a DC voltage superimposed on said AC voltage being applied across said two elements; said device being constituted so that DC voltage distributed to the photoconductive element decreases corresponding to decrease in the resistance of the photoconductive element relating to excitation by incident energy and that the AC photoconductive sensitivity of the photoconductive element is controlled through the DC voltage in response to the intensity of the incident energy.
A solid-state energy-responsive luminescent device as defined in claim 1, wherein said electroluminescent layer is composed of powder of electroluminescent fluorescent material and powder of resistive metal oxide which has reflective power against the light from said fluorescent material, said two powders being mixed with a vitreous medium.
Claim 2
Dependent Claim
28 words
A solid state energy-responsive luminescent device as defined in claim 2, wherein the specific resistivity of said electroluminescent layer is in a range of 107 to 109 ohm-cm.
Claim 3
Dependent Claim
29 words
A solid-state energy-responsive luminescent device as defined in claim 3, wherein said resistive metal oxide is at least one selected from a group including Sn02, Ti02, W03 and Sb205.
Claim 4
Dependent Claim
58 words
A solid-state energy-responsive luminescent device as defined in claim 1, wherein at least one resistive intermediate layer is interposed between said electroluminescent layer and said photoconductive layer, and the total DC resistance of the combined layer comprising said electroluminescent layer and said intermediate layer is lower than the DC resistance of said photoconductive element in a dark state.
Claim 5
Dependent Claim
38 words
A solid-state energy-responsive luminescent device as defined in claim 5, wherein said resistive intermediate layer is a compound layer consisting of a light-reflective layer positioned on the electroluminescent side and an impervious layer positioned on the photoconductive side.
Claim 6
Dependent Claim
32 words
A solid-state enerGy-responsive luminescent device as defined in claim 2, wherein one of said pair of electrodes comprises light pervious conductive film of metal oxide deposited on a light pervious glass substrate.