Photoelectric converter

A photoelectric converter, comprising:

• (a) a first semiconductor region of a first conductivity type,
• (b) a second semiconductor region of a second conductivity type for accumulation of carriers relevant to the second conductivity type among hole-electron pairs generated by photoexcitation disposed contiguous to the first semiconductor region;
• (c) a third semiconductor region of the first conductivity type for accumulation of carriers relevant to conductivity type among the hole-electron pairs generated by photoexcitation, disposed adjacent to the second semiconductor region by the medium of a high resistivity semiconductor region;
• (d) a fourth semiconductor region of the second conductivity type disposed contiguous to the third semiconductor region;
• and
• (e) bias means for separately forward biasing the second semiconductor region with respect to the first semiconductor region to read out the relevant carriers accumulated in the second semiconductor region and forward biasing the third semiconductor region with respect to the second semiconductor region to read out the relevant carriers accumulated in the third semiconductor region.

A photoelectric converter, comprising:

• (a) a transistor including:
• a first semiconductor region of a first conductivity type,
• a second semiconductor region of the first conductivity type, and
• a third semiconductor region of a second conductivity type opposite to the first conductivity type and operatively associated with the first and second semiconductor regions to form the transistor, said third semiconductor region being capable of accumulating photoexcited carriers therein;
• (b) first reference potential means;
• (c) first switching means for connecting the second semiconductor region to said first reference potential means for refreshing the third semiconductor region to extinguish the photoexcited carriers therein;
• (d) second reference potential means connected to said first semiconductor region;
• and
• (e) second switching means disposed between the third semiconductor region and a reference power supply providing a higher potential level than the first reference potential means,
• said second switching means being turned on to provide the third semiconductor region with the potential given by the reference power supply, and then being turned off so as to provide simultaneous occurrence of the off-state of the second switching means and the on-state of the first switching means.

A photoelectric converter, comprising:

• (a) a transistor including:
• a first semiconductor region of a first conductivity type,
• a second semiconductor region of the first conductivity type, and
• a third semiconductor region of a second conductivity type opposite to the first conductivity type and operatively associated with the first and second semiconductor regions to form the transistor, said third semiconductor region being capable of accumulating photoexcited carriers therein;
• (b) a capacitive load disposed connectable to said second semiconductor region;
• (c) switching means disposed between the third semiconductor region and a reference power supply;
• (d) bias means for forward biasing the third semiconductor region with respect to the second semiconductor region to read out the carriers accumulated in the third semiconductor region through the capacitive load;
• and
• (e) a potential source connected to said first semiconductor region;
• said switching means being turned on for refreshing to extinguish the carriers in the third semiconductor region.

A photoelectric conversion process comprising the steps of:

• (A) providing a photoelectric converter comprising:
• (a) a transistor including:
• a first semiconductor region of a first conductivity type,
• a second semiconductor region of the first conductivity type, and
• a third semiconductor region of a second conductivity type opposite to the first conductivity type and operatively associated with the first and second semiconductor regions to form the transistor, said third semiconductor region being capable of accumulating photoexcited carriers therein;
• (b) a capacitive load disposed connectable to the second semiconductor region;
• and
• (c) reference potential means connected to the first semiconductor region;
• and
• (B) sequentially conducting the following stages of operations:
• (d) accumulation operation, comprising exposing the transistor to accumulate photoexcited carriers in the third semiconductor region;
• (e) readout operation, comprising:
• connecting the capacitive load to the second semiconductor region;
• and
• forward biasing the third semiconductor region with respect to the second semiconductor region to read out the carriers accumulated in the third semiconductor region through the capacitive load;
• and
• (f) refreshing operation, comprising:
• providing a reference potential to the second semiconductor region, and
• forward biasing the third semiconductor region with respect to the second semiconductor region to extinguish the carriers in the third semiconductor region.

A photoelectric converter for providing an output signal which varies as a function of light energy received thereby, comprising:

• a transistor including a first semiconductor region, a second semiconductor region connected to an output circuit which includes a capacitive element, and a third semiconductor region which is operatively associated with the first and second semiconductor regions to form the transistor and being capable of accumulating carriers in response to the received light energy;
• and
• read-out means for reading out a signal dependent on the accumulated carriers;
• the third semiconductor region being coupled to a potential source which controls the potential of the third semiconductor region preferentially to the first and second semiconductor regions and forward biases the junction of said third and second semiconductor regions during readout, the output signal being produced as a voltage across the capacitive element.

A photoelectric converter for providing an output signal which varies as a function of light energy received thereby, comprising:

• a transistor including a first semiconductor region, a second semiconductor region connected to an output circuit which includes a capacitive element, and a third semiconductor region which is operatively associated with the first and second semiconductor regions to form the transistor and being capable of accumulating carriers in response to the received light energy;
• means for extinguishing the accumulated carriers in a refresh step after the production of the output signal;
• and
• bias means for controlling the potential of the third semiconductor region preferentially to the first and second semiconductor regions;
• wherein, in the refresh step, the extinguishing means forward biases the junction of the third and second semiconductor regions.