Solid-state imaging device pixel groups for distance sensor charge transfer
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Solution Overview
Problem
Existing solid-state imaging devices face challenges in achieving high-speed image acquisition for ranging photography due to the need for multiple memory components, which decreases sensitivity and limits the number of pixels, making it difficult to use as a multi-pixel device, and in CCD-type devices, detecting delay components in frame units hampers fast image acquisition for ranging.
Innovation Solution
A solid-state imaging device with first and second pixel groups, each equipped with photoelectric conversion units, charge accumulation units, and reset units, synchronously detecting precedent and following components of reflection light pulses within one frame period, allowing for both general photography and ranging photography with a large number of pixels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If at least two memory components are required in a single pixel for charge sorting method, then distance measurement capability is achieved, but sensitivity decreases and aperture ratio cannot be increased
Solution Approach 1:
The pixel array is divided into two distinct pixel groups: first pixel groups for detecting precedent components and second pixel groups for detecting following components. This segmentation allows each pixel to maintain a single memory component while achieving TOF functionality through the distributed architecture across the array.
Solution Approach 2:
The solid-state imaging device achieves multiple functions: general photography mode using all pixels for light detection, and ranging photography mode using the divided pixel groups for delay time measurement. The same hardware structure supports both imaging and distance measurement without requiring separate dedicated components.
2Adaptability or versatility
If at least two memory components are required in a single pixel for charge sorting method, then distance measurement capability is achieved, but the number of pixels that can be provided is limited
Solution Approach 1:
Instead of requiring two memory components per pixel, the system segments the pixel array into two functional groups at the array level. Each individual pixel maintains a single memory component, but the collective segmentation of the array enables delay time detection through coordinated operation of first and second pixel groups.
Solution Approach 2:
The solution moves from a vertical integration approach (multiple memory components stacked within a single pixel) to a horizontal/dimensional approach (dividing the two-dimensional pixel array into two functional groups). This dimensional shift allows maintaining high pixel density while achieving TOF functionality.
3Device complexity
If delay components of reflected light are detected in frame units in CCD-type solid-state imaging device, then structure is simplified, but image acquisition speed for ranging is reduced
Solution Approach 1:
The irradiation light is emitted as periodic pulses, and the detection timing is synchronized to these pulses. First pixel groups detect signals during specific periods after pulse emission, while second pixel groups detect signals in subsequent periods. This periodic synchronized detection enables high-speed ranging while maintaining a relatively simple structure.
Solution Approach 2:
The detection timing for first and second pixel groups is predetermined and synchronized to the irradiation light pulse timing. This preliminary arrangement of detection timing allows the system to capture delay time information at high speed without requiring complex real-time processing, thus improving acquisition speed while keeping structure manageable.
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
Enables high-speed image acquisition for ranging photography while maintaining sensitivity and allowing for a large number of pixels, effectively combining general photography and ranging capabilities in a single device.
Implementation Method 1
each pixel of the first pixel group includes a first photoelectric conversion unit for converting, into an electric charge, a reflection light pulse from an object irradiated with an irradiation light pulse
Data Source
AI summary
A solid-state imaging device comprises a first pixel group includes a first photoelectric conversion unit that converts into electric charges reflection light pulses from an object irradiated with an irradiation light pulse, a first electric charge accumulation unit accumulating the electric charges in synchrony with turning on the irradiation light pulses, and a first reset unit resetting the electric charges; and a second pixel group includes a second photoelectric conversion unit that converts the reflection light into electric charges, a second electric charge accumulation unit that accumulates the electric charges synchronously with a switching the irradiation light pulses from on to off, and a second reset unit that releases a reset of the electric charges converted by the second photoelectric conversion unit.