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US 7,332,786 B2Granted
Anti-blooming storage pixel
AssigneeMicron Technology, Inc.
InventorsPeter P. Altice, Jr., Jeffrey A. McKee
Life of this patent
Estimating the term…
Abstract
Embodiments of the present invention provide pixel cells with increased storage capacity, which are capable of anti-blooming operations. In an exemplary embodiment a pixel cell has an electronic shutter that transfers charge generated by a photo-conversion device to a storage node before further transferring the charge to the pixel cell's floating diffusion node. Each pixel cell also includes an anti-blooming transistor for directing excess charge out of each respective pixel cell, thus preventing blooming. Additionally, two or more pixel cells of an array may share a floating diffusion node and reset and readout circuitry.
Claims47
A pixel cell comprising:
- a photo-conversion device;
- a storage node switchably coupled to the photo-conversion device for receiving charge from the photo-conversion device via a shutter transistor;
- a capacitor electrically connected to a gate of the shutter transistor and the storage node;
- a sensing node switchably coupled to the storage node for receiving the charge from the storage node;
- and
- an anti-blooming circuit electrically connected to the photo-conversion device for selectively draining charge from the photo-conversion device.
3 more elements
A pixel cell comprising:
- a photo-conversion device;
- a storage node switchably coupled to the photo-conversion device for receiving charge from the photo-conversion device via a shutter transistor, a gate of the shutter transistor being electrically connected to the storage node;
- a first barrier region adjacent to the storage node, the barrier region being electrically connected to the gate of the shutter transistor;
- a sensing node switchably coupled to the storage node for receiving the charge from the storage node;
- and
- an anti-blooming circuit electrically connected to the photo-conversion device for selectively draining charge from the photo-conversion device.
3 more elements
A pixel sensor array comprising:
- at least one subset of pixel cells at a surface of a substrate, the at least one subset comprising:
- at least two photo-conversion devices;
- at least two anti-blooming transistors, each anti-blooming transistor being electrically connected to a respective photo-conversion device for selectively draining charge from the respective photo-conversion device;
- at least two storage nodes switchably coupled to a respective photo-conversion device for receiving charge from the respective photo-conversion device via a respective shutter transistor, a gate of each shutter transistor being electrically connected to a respective storage node;
- and
- a sensing node switchably coupled to the storage nodes for receiving the charge from the storage nodes via respective transfer transistors, a gate of each transfer transistor being electrically connected to a respective gate of an anti-blooming transistor.
3 more elements
A processor-based system comprising:
- a processor;
- and
- an imager coupled to the processor, the imager comprising an array of pixel cells, at least one of the pixel cells comprising:
- a photo-conversion device;
- a storage node switchably coupled to the photo-conversion device for receiving charge from the photo-conversion device via a shutter transistor;
- a capacitor electrically connected to a gate of the shutter transistor and the storage node;
- a sensing node switchably coupled to the storage node for receiving the charge from the storage node;
- and
- an anti-blooming circuit electrically connected to the photo-conversion device for selectively draining charge from the photo-conversion device.
6 more elements
A processor-based system comprising:
- a processor;
- and
- an imager coupled to the processor, the imager comprising an array of pixel cells, at least one of the pixel cells comprising:
- a photo-conversion device;
- a storage node switchably coupled to the photo-conversion device for receiving charge from the photo-conversion device via a shutter transistor, a gate of the shutter transistor being electrically connected to the storage node;
- a first barrier region adjacent to the storage node, the barrier region being electrically connected to the gate of the shutter transistor;
- a sensing node switchably coupled to the storage node for receiving the charge from the storage node;
- a second barrier region between the storage node and the sensing node;
- and
- an anti-blooming circuit electrically connected to the photo-conversion device for selectively draining charge from the photo-conversion device.
7 more elements
An integrated circuit comprising:
- an array of pixel cells, each pixel cell comprising:
- a photo-conversion device;
- a storage node switchably coupled to the photo-conversion device for receiving charge from the photo-conversion device via a shutter transistor;
- a capacitor electrically connected to a gate of the shutter transistor and the storage node;
- a sensing node switchably coupled to the storage node for receiving the charge from the storage node;
- and
- an anti-blooming circuit electrically connected to the photo-conversion device for selectively draining charge from the photo-conversion device.
4 more elements
An integrated circuit comprising:
- an array of pixel cells, each pixel cell comprising:
- a photo-conversion device;
- a storage node switchably coupled to the photo-conversion device for receiving charge from the photo-conversion device via a shutter transistor, a gate of the shutter transistor being electrically connected to the storage node;
- a first barrier region adjacent to the storage node, the barrier region being electrically connected to the gate of the shutter transistor;
- a sensing node switchably coupled to the storage node for receiving the charge from the storage node;
- and
- an anti-blooming circuit electrically connected to the photo-conversion device for selectively draining charge from the photo-conversion device.
4 more elements
Dependencies are inferred from the claim text.