Dv2js Innovation Llp.

Neha Priyadarshini

Mukul Sarkar

A method and a system are described for dynamic range enhancement in CMOS image sensors using charge-transfer amplification. The method involves resetting a pixel array and other nodes of the CMOS image sensor. It involves receiving light for a predetermined duration on the pixel array layered with photodiodes. It involves configuring an integration time of incident light at the photodiodes, for a desired exposure and releasing photoelectrons to form a current signal. An equivalent voltage signal is built allowing a voltage build-up by charging a storage capacitance, and thereafter adjusting the voltage build-up by adjusting a ratio between the storage capacitance and amplification capacitance. The voltage signal is then integrated with the current signal in order to obtain an integrated signal of amplified gain, and the method involves generating a resultant electronic signal with a higher amplification factor and an enhanced gain as compared to the input electronic signal.

Dynamic range enhancement in CMOS image sensors using charge transfer amplification

A method and a system are disclosed for pixel-embedded signal amplification of a CMOS image sensor using multi-step voltage-gain enhancement. It involves activating a row of the CMOS image sensor by resetting switches SRST, SH1and SH2to charge nodes PD1, PD2, SD1, and SD2 to a pre-set voltage potential and VRST. The CMOS sensor switches OFF SRST, SH1and SH2for integration of the charges at PD1 for producing a corresponding photo-generated signal. This signal is sampled by transferring to a gate of source follower SF1, to produce an amplified signal. It further involves double-sampling the amplified signal for removing any pixel-offset variation to produce a resultant signal. The said method is repeated for second row of CMOS image sensor for implementing additional gain on the resultant voltage signal, and the same is finally converted to digital bits to obtain an output signal of with enhanced gain.

High dynamic range CMOS image sensor having multi-step voltage gain enhancement for low light vision

A method and a system are described for improving a dynamic range of a CMOS image sensor by pixel-embedded signal amplification. An electromagnetic radiation is incident for a predetermined duration on a pixel array including a plurality of photodiodes. The photodiodes release electrons in form of an input electronic signal and the released input signal is temporarily stored in a storage node. The said input signal is then transferred to a gate of an in-pixel amplifier, which is configured to dynamically alternate between modes of capacitance and switched biasing, using a single in-pixel switch. Then, the in-pixel amplifier is modulated while in capacitance mode for a voltage build-up and this augment gain of the input signal. Thereafter, the in-pixel amplifier alternates to a switched biasing mode for suppression of noise signals. Finally, a resultant electronic signal is generated with a high gain after processing and suppression of the noise signals.

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New Delhi, India

Neha Priyadarshini