US 5,308,969 A · Image sensor

Abstract

An image sensor is provided with a plurality of photodiodes each having a better forward-current responsiveness and a smaller dark current in the reverse direction. Each of the photodiodes includes a two-layered photoelectric conversion layer made of non-doped hydrogenated amorphous silicon. One of these two layers, which has an interface that prevents electrons from escaping when photogenerated electric charge is stored, is deposited at a lower temperature than the other. The photodiodes are arranged in rows on a transparent electrode. The photodiodes operate in pairs, each pair corresponding to one picture element and having a first photodiode connected to a second photodiode in series, with opposite polarity. All the first photodiodes are connected to a detecting circuit and all the second photodiodes are connected to a pulse generating circuit.

Claims5

Dependent claims

An image sensor comprising:

a transparent substrate;
a plurality of photoreceptor elements arranged in rows on the transparent substrate, each of said photoreceptor elements comprising:
a first photodiode, and
a second photodiode directly connected to said first photodiode in series, with opposition polarity,
wherein at least one of said first photodiode and said second photodiode has a multilayered photoelectric conversion region of hydrogenated amorphous silicon, said photoelectric conversion region including,
a first non-doped hydrogenated amorphous silicon layer, and
a second non-doped hydrogenated amorphous silicon layer;
a detecting circuit connected to said first photodiode of each of said photoreceptor elements;
and
a pulse generating circuit connected to said second photodiode of each of said photoreceptor elements.

7 more elements

Dependencies are inferred from the claim text.

Image sensor

Life of this patent

Image sensor

Life of this patent

Abstract

Claims5