Solid-State Imaging Pixel Pulse Generation Circuit
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Solution Overview
Problem
Existing solid-state imaging elements face challenges in securing a sufficient time width of a pulse signal, which is necessary for signal processing, particularly in systems where analog to digital conversion is performed simultaneously across multiple pixels, leading to increased circuit area requirements.
Innovation Solution
Incorporating a pulse generation circuit within each unit pixel that feeds back a delayed signal from a comparator to itself, allowing for arithmetic operation to generate a pulse signal, and utilizing a latch circuit to secure the data code using this pulse signal, with adjustable logical threshold values and transistor configurations to optimize the pulse generation process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If a pulse generation circuit is added to secure sufficient pulse width, then the time width of pulse signal is improved, but the circuit area increases
Solution Approach 1:
The pulse generation circuit is merged with the existing comparator circuit by feeding back the delayed output signal to the comparator input. This integration allows the same hardware components to serve dual purposes: comparison and pulse generation, thereby securing sufficient pulse width without proportionally increasing circuit area.
Solution Approach 2:
A feedback mechanism is implemented where the output signal of the comparator is delayed and fed back to the comparator input. This feedback loop generates a pulse signal with sufficient time width by utilizing the temporal difference between the original and delayed signals, achieving the desired pulse duration without adding extensive external circuitry.
2Area of stationary object
If circuit area is reduced, then device integration is improved, but the time width of pulse signal becomes insufficient
Solution Approach 1:
The circuit utilizes dynamic signal processing by introducing a delay element that creates a time-shifted version of the output signal. This dynamic approach allows the generation of adequate pulse width through temporal manipulation rather than static circuit expansion, maintaining compact area while ensuring sufficient signal duration for reliable data acquisition.
Solution Approach 2:
The invention changes the temporal parameter of the signal by applying a delay to the output signal. By modifying the time characteristic through the delay element and subsequent feedback, the pulse width is extended to sufficient levels without requiring additional physical space, thus resolving the contradiction between area reduction and pulse width maintenance.
Data Source
AI summary
The present disclosure relates to a solid-state imaging element and electronic equipment that make it possible to sufficiently secure a time width of a pulse signal. In an AD converter for each unit pixel, a pulse generation circuit feeds back a delay signal obtained by delaying an output signal of the comparator to the comparator and arithmetically operates the output signal and the delay signal to generate a pulse signal. A latch circuit latches the pulse signal generated by the pulse generation circuit. The present disclosure can be applied to a solid-state imaging element of a stacked type and a back side illumination type.