Radiation Imaging Pixel Array First Frame Artifact Reduction
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Solution Overview
Problem
Existing radiation imaging apparatuses suffer from artifacts in the first frame of moving image capturing due to differences in the preparation state and operation between the first frame and subsequent frames, leading to discontinuity in image continuity.
Innovation Solution
A radiation imaging apparatus with a pixel array that includes conversion, holding, and reset units, where a control unit coordinates concurrent reset and holding operations based on radiation timing signals, and a selection unit performs sequential pixel selection from the accumulation period of the previous frame to the holding operation, using dummy read operations if necessary to maintain consistency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the selection operation is performed in the accumulation period of the conversion unit, then the frame rate can be increased and artifacts due to resetting can be suppressed, but artifacts may occur in the first frame image due to differences in operation period between the first frame and subsequent frames
Solution Approach 1:
The invention applies preliminary action by performing a dummy selection operation in the accumulation period before the holding operation in the first frame. This preliminary dummy operation ensures that the selection unit and pixel circuits are in the same operational state as in subsequent frames, preventing artifacts caused by the difference in operation timing between the first frame and later frames.
2Productivity
If the resetting is performed concurrently on all pixels based on radiation timing signal, then the frame rate can be increased, but the selection operation may not complete for all pixels leading to potential data loss
Solution Approach 1:
The invention applies dynamics by making the selection operation flexible and adaptive. The selection unit dynamically adjusts its operation based on whether a dummy selection has been performed in the accumulation period. In the first frame, a dummy selection is performed before the holding operation, while in subsequent frames, the normal selection operation proceeds without the dummy step, allowing the system to maintain reliability across different frame conditions.
3Device complexity
If the selection operation is skipped in the accumulation period to simplify the operation, then the device complexity is reduced, but artifacts occur in the first frame due to inconsistent preparation state
Solution Approach 1:
The invention applies the taking out principle by extracting the dummy selection operation as a separate, optional step that is performed only in specific conditions (the first frame's accumulation period). This isolated dummy operation addresses the artifact problem without requiring fundamental changes to the overall selection mechanism, maintaining simplicity while ensuring image quality consistency.
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 reduces artifacts in the first frame by ensuring consistent pixel preparation and operation with subsequent frames, enhancing image continuity and reducing artifacts.
Implementation Method 1
a conversion unit configured to convert radiation into a charge
Data Source
AI summary
A radiation imaging apparatus includes a pixel array including a plurality of pixels, each including a conversion unit, a holding unit, an output unit, and a reset unit, a control unit configured to control the pixel array to perform a reset operation for concurrently performing resetting on the plurality of pixels and a holding operation for concurrently performing holding on the plurality of pixels, based on a control signal indicating timing of generation of radiation, and a selection unit configured to perform a selection operation for sequentially selecting a pixel. The selection unit selects at least part of the plurality of pixels in a period from when the control unit performs the reset operation to when the control unit performs the holding operation based on a first control signal among a plurality of the control signals.