The present invention relates to an image sensor and to an imaging system comprising such a sensor. According to the invention, the overall conversion curve describing the conversion between photon flux and digital number comprises a first region in which the conversion is essentially linear and a second region in which the conversion is essentially non-linear. According to the invention, the non-linearity of the second region is obtained by operating the photodiode of the image sensor in its non-linear range and by changing the gain associated with the conversion between pixel voltage and digital number.

An image data transmission system and an image data transmission method are provided. The image data transmission system includes an image sensing device, a master device, and a serial transmission bus. The serial transmission bus electrically connects the image sensing device and the master device. The master device transmits a read command to the image sensing device through the serial transmission bus, and the image sensing device transmits a first data sequence to the master device through the serial transmission bus in response to the read command.

A pixel includes a photodiode and a readout node for receiving charge transferred from the photodiode. The readout node is configured to have a variable capacitance that is non-linear with respect to a voltage at the readout node. The readout node is resettable. The readout node may be configured to have a lower capacitance when reset to a reset voltage than when getting filled with charge from the photodiode. The readout node may be configured such that the capacitance of the readout node continuously increases as additional charge is received by the readout node after the readout node is reset. The readout node may be configured such that the capacitance of the readout node jumps from a first capacitance to a second capacitance after the readout node has been filled with a certain amount of charge. An image sensor includes a pixel array with a plurality of the pixels.

An exposure method, an electronic device and a master-slave system are provided. The electronic device includes an image capturing circuit and a processor coupled to the image capturing circuit. The processor obtains an exposure command and a first quantity, controls the image capturing circuit to perform an exposure operation to capture an image according to the exposure command, and determines whether a quantity of the image reaches the first quantity. When the quantity of the image does not reach the first quantity, the processor performs the operation of controlling the image capturing circuit to perform the exposure operation to capture the image again. When the quantity of the image reaches the first quantity, the processor stops controlling the image capturing circuit to perform the exposure operation.

An example imaging system includes a digital conversion circuit and a plurality of pixel circuits each having a photodiode, a biasing circuit, a charge-to-voltage converter, and a switch. The photodiode is configured to generate charges in response to light or radiation. The biasing circuit includes an operational amplifier having an input signal port for receiving a bias reference signal which controls a bias current flowing through an internal circuit of the operational amplifier. The charge-to-voltage converter is configured to accumulate the charges drained by the biasing circuit and convert the accumulated charges into a corresponding output voltage. The switch configured to selectively couple the charge-to-voltage converter to at least one data line. The digital conversion circuit is configured to generate a digital correlated signal sample for each pixel circuit using a difference between a digital signal sample and a digital reset level sample.

An electronic device and a fingerprint sensing method are provided. The electronic device includes a display panel, a fingerprint sensor, and an integrated driver chip. The display panel includes a plurality of pixel units arranged in an array. The integrated driver chip integrates a display driver circuit and a fingerprint sensing circuit. When the pixel units of the display panel are in an undriven state and a finger object is in contact with a sensing area of the display panel to perform a fingerprint unlock operation, the display driver circuit drives at least a portion of the pixel units corresponding to the sensing area, so that at least a portion of the pixel units provide illumination light to the sensing area. The fingerprint sensing circuit drives the fingerprint sensor to capture a fingerprint feature image of the finger object.

Some embodiments provide an apparatus and method wherein the non-linearity of the response of a multi-bit QIS is controllable (e.g., selectively variable) by dynamically choosing the bit depth n during A/D conversion, and/or later (i.e., post-conversion) by firmware and/or software.

In one example, an apparatus comprises: a comparator; a sampling capacitor having a first plate and a second plate. The first plate is coupled with an output of a charge sensing unit that senses charge generated by a photodiode, whereas the second plate is coupled with an input of the comparator. The apparatus further includes a controller configured to: at a first time, set a first voltage across the sampling capacitor based on an output voltage of the charge sensing unit; reset the charge sensing unit to set the first plate at a second voltage and to set the second plate at a third voltage based on the first voltage and the second voltage; compare, using the comparator, the third voltage against one or more thresholds; and generate, based on the comparison result, a quantization result of the output voltage of the charge sensing unit at the first time.

A high dynamic range image sensors enabled by integrating broadband optical filters with individual sensor pixels of a pixel array. The broadband optical filters are formed of engineered micro or nanostructures that exhibit large differences in transmittance, e.g. up to 5 to 7 orders of magnitude. Such high transmittance difference can be achieved by using a single layer of individually designed filters, which show varied transmittance as a result of the distinct absorption of various material and structures. The high transmittance difference can also be achieved by controlling the polarization of light and using polarization-sensitive structures as filters. With the presence of properly designed integrated nanostructures, broadband transmission spectrum with transmittance spanning several orders of magnitude can be achieved. This enables design and manufacturing of image sensors with high dynamic range which is crucial for applications including autonomous driving and surveillance.

An electronic device and an image capture method are provided. The electronic device includes an image sensor, a ramp analog to digital converter, and a memory. The image sensor includes a plurality of pixel units arranged in an array, and the pixel units output a plurality of first image capturing signals and a plurality of second image capturing signals in an image capturing operation. The ramp analog to digital converter generates a plurality of most significant bit data corresponding to a plurality of pixels according to a first nonlinear ramp signal and the first image capturing signals, and generates a plurality of least significant bit data corresponding to the plurality of pixels according to a second nonlinear ramp signal and the second image capturing signals. The memory stores the most significant bit data of these pixels and the least significant bit data of these pixels together to generate frame data.