Abstract: A high dynamic range imaging pixel may include a photodiode that generates charge in response to incident light. When the generated charge exceeds a first charge level, the charge may overflow through a first transistor to a first storage capacitor. When the generated charge exceeds a second charge level that is higher than the first charge level, the charge may overflow through a second transistor. The charge that overflows through the second transistor may alternately be coupled to a voltage supply and drained or transferred to a second storage capacitor for subsequent readout. Diverting more overflow charge to the voltage supply may increase the dynamic range of the pixel. The amount of charge diverted to the voltage supply may therefore be updated to control the dynamic range of the imaging pixel.

Abstract: A high dynamic range imaging pixel may include first and second photodiodes that generate charge in response to incident light. The second photodiode may have a higher sensitivity than the first photodiode. When generated charge in the first photodiode exceeds a given charge level, the charge may overflow through a transistor to a capacitor. The overflow path from the first photodiode to the capacitor may optionally pass through the floating diffusion region. A transistor may be coupled between the first and second photodiodes. A gain select transistor may be coupled between the floating diffusion region and the capacitor. After sampling the overflow charge, the charge from both the first and second photodiodes may be sampled. In one arrangement, overflow charge may be transferred to a capacitor in a subsequent row.

Abstract: An image sensor may include a shared pixel circuit having multiple photodiodes coupled to a common floating diffusion node via respective charge transfer gates. First, the pixel circuit may be reset, and a sample-and-hold reset (SHR) value may be read out. Charge from a first of the photodiodes may be transferred to the floating diffusion node, and a first sample-and-hold signal (SHS) value may be read out. A first correlated double sampling (CDS) value is obtained by computing the difference between the SHR value and the first SHS value. Without resetting again, charge from a second of the photodiodes may be transferred to the floating diffusion node, and a second SHS value may be read out. A second CDS value is obtained by computing the difference between the first and second SHS values. Reading out the shared pixel circuit in this way substantially reduces power consumption.

Abstract: A high dynamic range imaging pixel may include a photodiode that generates charge in response to incident light. When the generated charge exceeds a first charge level, the charge may overflow through a first transistor to a first storage capacitor. When the generated charge exceeds a second charge level that is higher than the first charge level, the charge may overflow through a second transistor. The charge that overflows through the second transistor may alternately be coupled to a voltage supply and drained or transferred to a second storage capacitor for subsequent readout. Diverting more overflow charge to the voltage supply may increase the dynamic range of the pixel. The amount of charge diverted to the voltage supply may therefore be updated to control the dynamic range of the imaging pixel.

Abstract: A high dynamic range imaging pixel may include a photodiode that generates charge in response to incident light. When the generated charge exceeds a first charge level, the charge may overflow through a first transistor to a first storage capacitor. When the generated charge exceeds a second charge level that is higher than the first charge level, the charge may overflow through a second transistor. The charge that overflows through the second transistor may alternately be coupled to a voltage supply and drained or transferred to a second storage capacitor for subsequent readout. Diverting more overflow charge to the voltage supply may increase the dynamic range of the pixel. The amount of charge diverted to the voltage supply may therefore be updated to control the dynamic range of the imaging pixel.

Abstract: A high dynamic range imaging pixel may include first and second photodiodes that generate charge in response to incident light. The second photodiode may have a higher sensitivity than the first photodiode. When generated charge in the first photodiode exceeds a given charge level, the charge may overflow through a transistor to a capacitor. The overflow path from the first photodiode to the capacitor may optionally pass through the floating diffusion region. A transistor may be coupled between the first and second photodiodes. A gain select transistor may be coupled between the floating diffusion region and the capacitor. After sampling the overflow charge, the charge from both the first and second photodiodes may be sampled. In one arrangement, overflow charge may be transferred to a capacitor in a subsequent row.

Abstract: A high dynamic range imaging pixel may include first and second photodiodes that generate charge in response to incident light. The second photodiode may have a higher sensitivity than the first photodiode. When generated charge in the first photodiode exceeds a given charge level, the charge may overflow through a transistor to a capacitor. The overflow path from the first photodiode to the capacitor may optionally pass through the floating diffusion region. A transistor may be coupled between the first and second photodiodes. A gain select transistor may be coupled between the floating diffusion region and the capacitor. After sampling the overflow charge, the charge from both the first and second photodiodes may be sampled. In one arrangement, overflow charge may be transferred to a capacitor in a subsequent row.

Abstract: An image sensor may include a shared pixel circuit having multiple photodiodes coupled to a common floating diffusion node via respective charge transfer gates. First, the pixel circuit may be reset, and a sample-and-hold reset (SHR) value may be read out. Charge from a first of the photodiodes may be transferred to the floating diffusion node, and a first sample-and-hold signal (SHS) value may be read out. A first correlated double sampling (CDS) value is obtained by computing the difference between the SHR value and the first SHS value. Without resetting again, charge from a second of the photodiodes may be transferred to the floating diffusion node, and a second SHS value may be read out. A second CDS value is obtained by computing the difference between the first and second SHS values. Reading out the shared pixel circuit in this way substantially reduces power consumption.

Abstract: A high dynamic range imaging pixel may include a photodiode, an overflow node, and an overflow path between the photodiode and the overflow node. The imaging pixel may have an overlapping overflow integration time and photodiode integration time. The overflow integration time may be shorter than the photodiode integration time. At the end of the overflow integration time, an uncorrelated double sample of overflow charge may be obtained. The capacity of the photodiode is then increased and charge continues to accumulate in the photodiode until the conclusion of the photodiode integration time. A correlated double sample of charge from the photodiode may then be obtained. For additional increases to dynamic range, the overflow charge may be repeatedly sampled and reset throughout the overflow integration time, effectively increasing the overflow capacity. The overflow samples may be integrated on a buffer to track the total overflow charge.

Abstract: A high dynamic range imaging pixel may include first and second photodiodes that generate charge in response to incident light. The second photodiode may have a higher sensitivity than the first photodiode. When generated charge in the first photodiode exceeds a given charge level, the charge may overflow through a transistor to a capacitor. The overflow path from the first photodiode to the capacitor may optionally pass through the floating diffusion region. A transistor may be coupled between the first and second photodiodes. A gain select transistor may be coupled between the floating diffusion region and the capacitor. After sampling the overflow charge, the charge from both the first and second photodiodes may be sampled. In one arrangement, overflow charge may be transferred to a capacitor in a subsequent row.

Abstract: An image sensor may include an array of image pixels. Control circuitry coupled to the array of pixels may be configured to operate the image pixels in an overflow mode of operation, in which each pixel generates an overflow image signal and a complete image signal from a single exposure time period. The overflow image signals and the complete image signals from the pixels may be used to generate a high dynamic range image. While the floating diffusion region in each pixel is not in use, control circuitry may control that pixel to generate a reference signal at the floating diffusion region indicative of pixel-specific dark signal noise. Processing circuitry may mitigate for dark signal non-uniformity across the pixels by correcting the complete image signals using the reference signal to remove dark signal noise in the complete image signals.

Abstract: An image sensor may include an array of image pixels. Control circuitry coupled to the array of pixels may be configured to operate the image pixels in an overflow mode of operation, in which each pixel generates an overflow image signal and a complete image signal from a single exposure time period. The overflow image signals and the complete image signals from the pixels may be used to generate a high dynamic range image. While the floating diffusion region in each pixel is not in use, control circuitry may control that pixel to generate a reference signal at the floating diffusion region indicative of pixel-specific dark signal noise. Processing circuitry may mitigate for dark signal non-uniformity across the pixels by correcting the complete image signals using the reference signal to remove dark signal noise in the complete image signals.

Abstract: An image senor may include an array of pixels controlled by row control circuitry. Each pixel may include a photodiode for generating image signals and a charge storage structure coupled to a floating diffusion region and configured to generate and store parasitic light noise level signals. The image signals and the parasitic light noise level signals may be read out in the same readout cycle using shared or separate readout circuitry. Processing circuitry may selectively process the image signals based on the parasitic light noise level signals to generate image signals with reduced noise.

Abstract: Various embodiments of the present technology may comprise a method and apparatus for a polarizing filter. The polarizing filter may be formed such that the filter has varying polarization axes for blocking reflected light emitted from various directions. The method and apparatus may utilize metal wires or molecular chains to form curved lines across the filter, where the curved lines define the polarization axes.

Abstract: An imaging device may have an array of image sensor pixels. The array of image sensor pixels may have main pixels and reference pixels that are overlapped by optical stacks. The reference pixels may be more resistant to weathering, such as solar degradation, than the main pixels. For example, optical stacks overlapping the main pixels may include antireflection coatings, while optical stacks overlapping the reference pixels may not include antireflection coatings. Alternatively or additionally, the optical stacks overlapping the main pixels may include color filter resist formed from a first pigment, and the optical stacks overlapping the reference pixels may include color filter resist formed from a second pigment that is more resistant to weathering than the first pigment. Processing circuitry may compare outputs of the main pixels and the reference pixels to determine whether pixels in the array have been damaged.

Abstract: An image sensor may include an array of imaging pixels. Each imaging pixel may include a first sub-pixel that is configured to generate a high light-sensitivity signal and a second sub-pixel that is configured to generate a low light-sensitivity signal. The image sensor may also include a plurality of dark pixels that are shielded from incident light and processing circuitry. The processing circuitry may be configured to, for each imaging pixel, compare a value based on at least one of the high light-sensitivity signal and the low light-sensitivity signal to a threshold, modify the high light-sensitivity signal for the respective imaging pixel based at least on the low light-sensitivity signal for the respective imaging pixel when the value is less than the threshold, and modify the high light-sensitivity signal for the respective imaging pixel based on at least one dark pixel signal when the value is greater than the threshold.

Abstract: An imaging device may have an array of image sensor pixels. The array of image sensor pixels may have main pixels and reference pixels that are overlapped by optical stacks. The reference pixels may be more resistant to weathering, such as solar degradation, than the main pixels. For example, optical stacks overlapping the main pixels may include antireflection coatings, while optical stacks overlapping the reference pixels may not include antireflection coatings. Alternatively or additionally, the optical stacks overlapping the main pixels may include color filter resist formed from a first pigment, and the optical stacks overlapping the reference pixels may include color filter resist formed from a second pigment that is more resistant to weathering than the first pigment. Processing circuitry may compare outputs of the main pixels and the reference pixels to determine whether pixels in the array have been damaged.

Abstract: An image senor may include an array of pixels controlled by row control circuitry. Each pixel may include a photodiode for generating image signals and a charge storage structure coupled to a floating diffusion region and configured to generate and store parasitic light noise level signals. The image signals and the parasitic light noise level signals may be read out in the same readout cycle using shared or separate readout circuitry. Processing circuitry may selectively process the image signals based on the parasitic light noise level signals to generate image signals with reduced noise.

Abstract: An image sensor may include an array of imaging pixels. Each imaging pixel may include a first sub-pixel that is configured to generate a high light-sensitivity signal and a second sub-pixel that is configured to generate a low light-sensitivity signal. The image sensor may also include a plurality of dark pixels that are shielded from incident light and processing circuitry. The processing circuitry may be configured to, for each imaging pixel, compare a value based on at least one of the high light-sensitivity signal and the low light-sensitivity signal to a threshold, modify the high light-sensitivity signal for the respective imaging pixel based at least on the low light-sensitivity signal for the respective imaging pixel when the value is less than the threshold, and modify the high light-sensitivity signal for the respective imaging pixel based on at least one dark pixel signal when the value is greater than the threshold.

Abstract: A high dynamic range imaging pixel may include a photodiode that generates charge in response to incident light. When the generated charge exceeds a first charge level, the charge may overflow through a first transistor to a first storage capacitor. When the generated charge exceeds a second charge level that is higher than the first charge level, the charge may overflow through a second transistor. The charge that overflows through the second transistor may alternately be coupled to a voltage supply and drained or transferred to a second storage capacitor for subsequent readout. Diverting more overflow charge to the voltage supply may increase the dynamic range of the pixel. The amount of charge diverted to the voltage supply may therefore be updated to control the dynamic range of the imaging pixel.