Solid-State Imaging Device Charge Accumulation Potential Gradient
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Solid-state imaging devices face a trade-off between increasing saturated charge quantity and maintaining line rate, as expanding the charge accumulating portion to increase charge transfer time, which reduces the line rate.
Innovation Solution
Generating a potential difference within the charge accumulating portion to speed up charge transfer, preventing elongation of charge transfer time even when the charge accumulating portion is elongated to increase saturated charge quantity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the area of the charge accumulating portion is expanded to increase saturated charge quantity, then the saturated charge quantity is improved, but the charge transfer time is elongated which results in reduction of line rate
Solution Approach 1:
The patent applies parameter changes by introducing a potential difference across the charge accumulating portion, which modifies the electric field distribution and accelerates charge transfer velocity. This allows the system to maintain faster transfer rates despite increased accumulation capacity, resolving the trade-off between storage capacity and transfer speed
2Quantity of substance
If the length in the predetermined direction of the charge accumulating portion is elongated to increase saturated charge quantity, then the saturated charge quantity is improved, but the charge transfer time is elongated which reduces line rate
Solution Approach 1:
By applying a potential difference in the predetermined direction, the patent changes the electric field parameter to create a driving force that accelerates charge movement. This enables the elongated charge accumulating portion to maintain high transfer speeds, thereby preserving line rate while increasing saturated charge quantity
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 an increase in saturated charge quantity without sacrificing line rate by dominating charge migration with the potential difference, thereby maintaining efficient charge transfer.
Implementation Method 1
each having a photosensitive region which generates a charge according to incidence of light
Implementation Method 2
an electric potential gradient forming region which forms an electric potential gradient increasing along a predetermined direction parallel to the long sides
Implementation Method 3
a potential difference increasing toward the predetermined direction is generated in each charge accumulating portion. Thus the charge is dominated by the potential difference to migrate, so as to speed up a charge transfer speed
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A solid-state imaging device 1 is provided with a plurality of photoelectric converting portions 3 each having a photosensitive region 15 and an electric potential gradient forming region 17, and which are juxtaposed so as to be along a direction intersecting with a predetermined direction, a plurality of buffer gate portions 5 each arranged corresponding to a photoelectric converting portion 3 and on the side of the other short side forming a planar shape of the photosensitive region 15, and accumulates a charge generated in the photosensitive region 15 of the corresponding photoelectric converting portion 3, and a shift register 9 which acquires charges respectively transferred from the plurality of buffer gate portions 5, and transfers the charges in the direction intersecting with the predetermined direction, to output the charges. The buffer gate portion 5 has at least two gate electrodes which are arranged along the predetermined direction, and to which predetermined electric potentials are respectively applied so as to increase potential toward the predetermined direction.