CCD Pixel Crosstalk Suppression via Integrated Light-Shielding Protrusions
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Solution Overview
Problem
In CCD image sensors, adjacent light-sensitive pixels are prone to crosstalk and color mixing due to oblique light incidence at their boundaries, which existing light shields fail to adequately prevent.
Innovation Solution
The implementation of a solid-state image pickup device with clock wirings formed of light-shielding material and protrusions at the boundaries between light-sensitive pixels, reducing the gap and thereby minimizing crosstalk and color mixing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the light-shielding metal layer is patterned separately from clock wiring, then manufacturing is simpler, but gaps remain that allow oblique light to cause crosstalk
Solution Approach 1:
The light shield and clock wiring are merged into a single integrated structure. The clock wiring is formed to protrude toward the boundary between adjacent pixels, and the light-shielding metal layer is continuously formed over both the clock wiring and the channel stop, eliminating gaps and creating a unified light-shielding barrier that prevents both crosstalk and color mixing.
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 design effectively suppresses crosstalk and color mixing, even in miniaturized CCD image sensors, by optimizing the light-shielding properties at pixel boundaries, thereby stabilizing image quality.
Implementation Method 1
clock wirings extending respectively in a column direction between columns of the light-sensitive pixels and supplying each phase of the transfer clocks of a plurality of phases to the transfer electrode, the clock wiring being formed of a light-shielding material
Data Source
AI summary
In an image pickup portion of a frame transfer CCD image sensor, a constitution that inhibits color mixing from occurring between light-sensitive pixels adjacent along a vertical CCD shift register channel is provided. A protrusion extending on the channel is formed at a clock wiring formed on a channel stop of the vertical CCD shift register with an wiring layer having the light-shielding property. When the protrusion portion is disposed at a boundary of light-sensitive pixels in the channel, a non-light-shielding portion generated at the boundary can be suppressed. The protrusions are disposed so as to alternately protrude from the clock wirings on both sides of the channel.