Image Sensor Sampler Auto-Zero for Dynamic Range

The patent implements dynamic gain adjustment in the sampling circuit, switching between first gain and second gain modes based on illuminance conditions. The gain control circuit dynamically changes the amplification factor of the pixel signal before ADC conversion, allowing the system to adapt to different lighting conditions and reduce power consumption in high illuminance scenarios while maintaining measurement precision across the full dynamic range.

The patent changes the gain parameter of the sampling circuit based on detected illuminance levels. When high illuminance is detected, the circuit switches to a lower gain mode (second gain) to reduce the amplification of reset noise and lower power consumption. When low illuminance is detected, the circuit uses a higher gain mode (first gain) to maintain signal strength. This parameter adaptation resolves the contradiction between maintaining precision and reducing power consumption.

The patent dynamically adjusts the auto-zero operation mode based on illuminance conditions. In low illuminance conditions, the system performs auto-zero operation before comparing both reset signal and image signal in high gain mode to maximize noise removal. In high illuminance conditions, the system performs auto-zero operation only before comparing the reset signal in low gain mode, reducing power consumption while maintaining sufficient measurement precision for bright scenes.

The patent changes the gain parameter and auto-zero operation configuration based on illuminance levels. For high illuminance pixels, the system uses second gain mode with reduced auto-zero operations (only before reset signal comparison). For low illuminance pixels, the system uses first gain mode with full auto-zero operations (before both reset and image signal comparisons). This conditional parameter adjustment resolves the contradiction between precision and power consumption.

The patent implements a dynamic auto-zero strategy where the number of auto-zero operations performed depends on the illuminance condition detected for each pixel. For high illuminance pixels, only a single auto-zero operation is performed before reset signal comparison, sufficient for noise removal in bright conditions. For low illuminance pixels, multiple auto-zero operations are performed to ensure thorough noise removal. This dynamic approach balances power consumption and noise removal effectiveness.

The patent changes the operational parameters (gain mode and auto-zero operation count) based on pixel illuminance classification. High illuminance pixels use second gain mode with single auto-zero operation, while low illuminance pixels use first gain mode with multiple auto-zero operations. This parameter adaptation ensures that each pixel receives the appropriate level of noise processing, resolving the contradiction between power consumption and noise removal effectiveness.

The patent dynamically selects the gain mode for each pixel based on its illuminance level. Low illuminance pixels are routed through the high gain path (first gain mode) to amplify weak signals and improve detection accuracy. High illuminance pixels are routed through the low gain path (second gain mode) to avoid signal saturation and reduce power consumption. This dynamic routing resolves the contradiction between precision and power consumption for different pixel types.

The patent applies different gain characteristics to different spatial regions or pixel types within the image sensor. Each pixel can be configured with appropriate gain settings based on its local illuminance conditions, allowing low illuminance pixels to receive high gain amplification while high illuminance pixels use low gain. This localized quality adjustment optimizes both precision and power consumption for each pixel's specific operating conditions.