Solid-State Image Pickup Device Horizontal Pixel Addition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing solid-state image pickup devices using column Analog-to-Digital Conversion (ADC) systems face limitations in increasing frame rate due to the vertical direction-based thinning reading method and pixel addition, which reduces sensitivity and does not effectively enhance frame rate when these methods are applied in the horizontal direction.
Innovation Solution
A solid-state image pickup device with comparators and counters that compare analog signals with ramp-like reference signals, allowing for digital signal processing that adds values to counters based on comparison results to reduce information output in the horizontal direction, enabling frame rate enhancement by performing pixel addition in both vertical and horizontal directions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If thinning reading method is used to increase frame rate, then frame rate is improved, but sensitivity is reduced
Solution Approach 1:
The patent merges pixel signals from multiple pixels (both vertical and horizontal directions) through addition operations before output. By combining signals from 2x2 or larger pixel groups, the system maintains sensitivity through signal accumulation while enabling higher frame rates through reduced output data volume. The column processing portions perform horizontal addition of pixel signals, and subsequent vertical addition further reduces data quantity while preserving sensitivity.
Solution Approach 2:
The patent extends the thinning reading method from only vertical direction to include horizontal direction as well. By implementing pixel addition in both vertical and horizontal dimensions (2x2 or larger groups), the system achieves greater data reduction than vertical-only methods, enabling higher frame rates while maintaining sensitivity through multi-dimensional signal combination.
2Reliability
If pixel addition is performed in vertical direction only, then sensitivity is maintained, but frame rate enhancement is limited
Solution Approach 1:
The patent introduces horizontal direction pixel addition to complement the existing vertical direction addition. By implementing addition operations in both vertical and horizontal dimensions, the system reduces output data volume more effectively than vertical-only methods, enabling higher frame rates while maintaining sensitivity through multi-dimensional signal combination.
Solution Approach 2:
The patent segments the pixel array into multiple processing groups (2x2 or larger blocks) that are processed independently in column processing portions. This segmentation allows parallel processing of multiple pixel groups, reducing the overall data output requirement and enabling higher frame rates while maintaining sensitivity through within-group signal addition.
3Reliability
If more pixel information is read out to maintain sensitivity, then sensitivity is improved, but data transmission volume increases
Solution Approach 1:
The patent merges pixel signals from multiple pixels through addition operations in column processing portions before output. By combining signals from 2x2 or larger pixel groups both horizontally and vertically, the system reduces the total number of output data items while maintaining sensitivity through signal accumulation. This merging approach significantly reduces data transmission volume compared to reading out all individual pixel signals.
Solution Approach 2:
The patent performs pixel signal addition operations in advance within the column processing portions, before the data leaves the sensor array. This preliminary aggregation of pixel signals reduces the volume of data that needs to be transmitted and processed externally, while ensuring sensitivity is maintained through proper signal combination.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for a reduction in the amount of information output in the horizontal direction while maintaining sensitivity, thereby enhancing frame rate and reducing power consumption.
Implementation Method 1
a comparator compares an analog pixel signal with a reference signal having a RAMP waveform, thereby generating a pulse signal having a size (pulse width), in a time axis direction, corresponding to a size of the pixel signal
Implementation Method 2
a counter counts predetermined clock signals for a time period corresponding to the pulse width of the pulse signal, and the resulting count value is set as a digital signal corresponding to the size of the pixel signal
Implementation Method 3
a pixel array portion in which pixels including respective photo-electric conversion elements are two-dimensionally disposed in a matrix
Data Source
AI summary
A solid-state image pickup device includes: comparators; counters; and a control portion for carrying out control in such a way that in a phase of an addition mode, the two comparators and the two counters corresponding to the two pixel columns, respectively, are set as a unit, 1 is added to a second digit of one counter of the two counters when both the comparison results from the two comparators has a first logic, 1 is added to a first digit of the one counter when one of the comparison results from the two comparators has the first logic, and 1 is added to none of the first digit and the second digit of the one counter when both the comparison results from the two comparators has a second logic.