Signal processor having avalanche photodiodes

Claim 2

An avalanche photodiode comprising: a light receiving part for producing an avalanche multiplication of photo carriers; a carrier storage part for storing photo carriers produced by an avalanche multiplication in said light receiving part; reading means for reading the photo carriers from said carrier storage part; and control means for controlling a first potential barrier between said light receiving part and said carrier storage part, wherein said control means first controls the first potential barrier to have a height greater than a height of a read potential barrier provided by said reading means for a reset operation, and then maintains the height of the first potential barrier while the height of the read potential barrier is made greater than the height of the first potential barrier, so that said light receiving part produces an avalanche multiplication of photo carriers to be stored in the carrier storage part, the height of the read potential barrier then being made lower than the height of the first potential barrier for performing a reading operation.

Claim 3

The avalanche photodiode as set forth in claim 1, wherein said control means comprises a field-effect transistor having a gate to which a constant voltage is applied.

Claim 4

The avalanche photodiode as set forth in claim 1, wherein said light receiving part is formed integrally within a semiconductor substrate formed with said carrier storage part, said reading means and said control means.

Claim 5

The avalanche photodiode as set forth in claim 1, wherein said light receiving part is laminated on said semiconductor substrate formed with said carrier storage part, said reading means and said control means.

Claim 6

An avalanche photodiode comprising: a light receiving part for producing an avalanche multiplication of photo carriers; a carrier storage part for storing photo carriers produced by an avalanche multiplication in said light receiving part; reading means for reading the photo carriers from said carrier storage part; control means for controlling a first potential barrier between said light receiving part and said carrier storage part; and fixing means for fixing a potential of said light receiving part, wherein said control means first controls the first potential barrier to have a height greater than a height of a read potential barrier provided by said reading means and greater than a potential provided by said fixing means for a reset operation, and then maintains the height of the first potential barrier while the height of the read potential barrier and the potential provided by said fixing means are made greater than the height of the first potential barrier, so that said light receiving part produces an avalanche multiplication of photo carriers to be stored in the carrier storage part, the height of the read potential barrier and the potential provided by said fixing means then being made lower than the height of the first potential barrier for performing a reading operation.

Claim 7

An avalanche photodiode comprising: a light receiving part for producing an avalanche multiplication of photo carriers; a carrier storage part for storing photo carriers produced by an avalanche multiplication in said light receiving part; reading means for reading the photo carriers from said carrier storage part; control means for controlling a first potential barrier between said light receiving part and said carrier storage part; and fixing means for fixing a potential of said light receiving part, wherein said control means first controls the first potential barrier to have a height greater than a height of a read potential barrier provided by said reading means and greater than a potential provided by said fixing means for a reset operation, and then maintains the height of the first potential barrier while the height of the read potential barrier and the potential provided by said fixing means are made greater than the height of the first potential barrier, so that said light receiving part produces an avalanche multiplication of photo carriers to be stored in the carrier storage part, the height of the read potential barrier and the potential provided by said fixing means then being made lower than the height of the first potential barrier for performing a reading operation.

Claim 8

The avalanche photodiode as set forth in claim 5, wherein said control means comprises a field-effect transistor having a gate to which a constant voltage is applied.

Claim 9

The avalanche photodiode as set forth in claim 5, wherein said potential fixing means comprises a MOS transistor.

Claim 10

The avalanche photodiode as set forth in claim 5, wherein said light receiving part is formed integrally within a semiconductor substrate formed with said carrier storage part, said reading means, said control means and said potential fixing means.

Claim 11

The avalanche photodiode as set forth in claim 5, wherein said light receiving part is laminated on said semiconductor substrate formed with said carrier storage part, said reading means, said control means and said potential fixing means.

Claim 12

A signal processor comprising: a plurality of avalanche photodiodes each comprising: a light receiving part for producing an avalanche multiplication of photo carriers; a carrier storage part for storing photo carriers produced by an avalanche multiplication in said light receiving part; reading means for reading the photo carriers from said carrier storage part; and control means for controlling a first potential barrier between said light receiving part and said carrier storage part, wherein said control means first controls the first potential barrier to have a height greater than a height of a read potential barrier provided by said reading means for a reset operation, and then maintains the height of the first potential barrier while the height of the read potential barrier is made greater than the height of the first potential barrier, so that said light receiving part produces an avalanche multiplication of photo carriers to be stored in the carrier storage part, the height of the read potential barrier then being made lower than the height of the first potential barrier for performing a reading operation, and wherein at least one of said avalanche photodiodes includes a shift register for driving said reading means.

Claim 13

A signal processor comprising: a plurality of avalanche photodiodes each comprising: a light receiving part for producing an avalanche multiplication of photo carriers; a carrier storage part for storing photo carriers produced by an avalanche multiplication in said light receiving part; reading means for reading the photo carriers from said carrier storage part; and control means for controlling a first potential barrier between said light receiving part and said carrier storage part, wherein said control means first controls the first potential barrier to have a height greater than a height of a read potential barrier provided by said reading means for a reset operation, and then maintains the height of the first potential barrier while the height of the read potential barrier is made greater than the height of the first potential barrier, so that said light receiving part produces an avalanche multiplication of photo carriers to be stored in the carrier storage part, the height of the read potential barrier then being made lower than the height of the first potential barrier for performing a reading operation, and wherein at least one of said avalanche photodiodes includes a shift register for driving said reading means.

Claim 14

The signal processor as set forth in claim 10, wherein said signal processor is an image sensor.

Claim 15

The signal processor as set forth in claim 10, wherein said signal processor is connected to a communications system.

Claim 16

The signal processor as set forth in claim 10, wherein said signal processor is mounted in a facsimile including a recording head.

Claim 17

The signal processor as set forth in claim 10, said signal processor is mounted in a video recorder including a magnetic head.