Low noise charge gain hybrid imager
AssigneeXerox Corporation
InventorRaj B. Apte
Life of this patent
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Abstract
In one aspect of the present application, provided is a charge gain imaging system and a method of operating the charge gain imaging system. The method includes collecting a pixel charge. The collected pixel charge being stored by a pixel capacitance (Cp). Thereafter the pixel having the stored pixel charge is selected via a pixel select switch, and the pixel voltage is transferred and stored by data line capacitance (Cd) of a data line of the imager. An amplifier select switch is activated connecting the data line to a charge amplifier, and a charge gain defined by a relationship Cd/Cp, is sensed by a charge amplifier.
Claims19
A method of operating a charge gain hybrid imaging system comprising:
- collecting a charge of a pixel of the imaging system;
- storing the collected pixel charge in a pixel capacitance (Cp);
- selecting the pixel via a pixel select switch;
- transferring the pixel voltage stored on the pixel capacitance (Cp) to a data line capacitance (Cd) of a data line which is associated with an effective charge gain of Cd/Cp;
- activating an amplifier select switch connecting the data line to a charge amplifier;
- and
- sensing the data line charge on a charge amplifier.
A low noise hybrid imaging system comprising:
- a pixel including,
- a transducer configured to generate charge in relation to a received stimulus,
- a pixel capacitance arranged to store the transducer output as a pixel charge on the capacitance (Cp),
- a voltage amplifier connected to transfer the pixel voltage to the select switch,
- a select switch line connected to the voltage amplifier, wherein activating the select switch line transfers the pixel voltage to the data line and a data line charge is stored in data line capacitance (Cd),
- an amplifier select switch connected at one end to the data line, and
- a charge amplifier connected to a second end of the amplifier select switch, wherein, when the amplifier select switch is turned on, a charge from the data line is sensed by the charge amplifier, the charge provided to the charge amplifier defined as the pixel charge multiplied by the data line capacitance (Cd) divided by the pixel capacitance (Cp).
A method of operating a charge gain hybrid imaging system having at least one pixel which transmits signal data to a charge amplifier, comprising:
- activating an amplifier reset switch to reset the charge amplifier;
- activating a pixel reset switch to reset the pixel;
- deactivating the amplifier reset switch, wherein a gate-source capacitive charge is injected into a front end of the charge amplifier;
- activating a sample switch a first time, wherein the gate-source capacitive charge is detected by the first sampling action, wherein an active state of an amplifier select switch encompasses the first active state of the sample switch;
- deactivating the amplifier select switch, isolating the pixel from the charge amplifier;
- activating a select switch, wherein charge from a pixel capacitance of the pixel is transferred to a data line capacitance of a data line, and wherein the amplifier select switch remains inactive while the select switch is active;
- activating the amplifier select switch, wherein the charge of the data line capacitance is transferred to the charge amplifier as a charge gain defined by the relationship Cd/Cp;
- and
- activating the sample switch a second time, wherein an output of the charge amplifier due to the charge gain is detected.
Dependencies are inferred from the claim text.