Shutter Blade Speed Control for Exposure Uniformity
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Solution Overview
Problem
Conventional shutter apparatuses fail to provide a proper exposure amount in both forward and return exposures due to the lack of consideration for the positional relationship between the pupil position and the light shielding member in the optical system, leading to exposure unevenness.
Innovation Solution
A shutter apparatus with a control unit that adjusts the exposure correction amounts of the light shielding member between forward and return exposures by varying the moving trajectories and speeds of the blade units, taking into account the pupil position and optical system geometry to ensure uniform exposure across the image sensor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the light shielding member moves at a constant speed in both forward and return exposures, then the structure is simple, but the exposure amount becomes uneven due to the positional relationship between the pupil position and the light shielding member
Solution Approach 1:
The patent applies the dynamics principle by making the light shielding member's moving speed variable rather than constant. The control unit adjusts the moving speed according to the positional relationship between the pupil position and the light shielding member, ensuring that the exposure amount remains uniform across different positions. This resolves the contradiction by accepting increased control complexity to achieve exposure uniformity.
Solution Approach 2:
The patent changes the speed parameter of the light shielding member dynamically during operation. By varying the moving speed based on the positional relationship with the pupil, the system compensates for exposure unevenness without requiring structural modifications to the shutter mechanism itself.
2Device complexity
If the exposure correction amount is kept the same for both forward and return exposures, then the control is simple, but the exposure amount cannot be properly acquired in both directions
Solution Approach 1:
The control system dynamically adjusts the exposure correction amount based on the exposure direction (forward or return). The control unit determines the appropriate correction amount by considering the positional relationship between the pupil position and the light shielding member, ensuring accurate exposure in both directions while maintaining relatively simple control logic.
3Manufacturing precision
If the moving trajectory of the light shielding member is adjusted to compensate for exposure unevenness, then the exposure amount becomes uniform, but the moving characteristics change due to abrasions over time
Solution Approach 1:
The patent implements a feedback mechanism where the control unit continuously determines the appropriate exposure correction amount based on the actual positional relationship between the pupil position and the light shielding member. This allows the system to compensate for changes in moving characteristics due to abrasions by dynamically adjusting the correction amount rather than relying on fixed mechanical adjustments.
Solution Approach 2:
The system changes the exposure correction parameter dynamically based on operating conditions and wear, rather than relying on fixed mechanical characteristics. This allows compensation for abrasion-induced changes without requiring physical modifications to the shutter mechanism.
Data Source
AI summary
A shutter apparatus includes a shutter base plate having an opening, a light shielding member movable to provide a closed state for closing the opening and an open state for opening the opening, and at least one processor or circuit configured to perform operations of a control unit configured to control the light shielding member configured to reciprocate relative to the opening so as to move the light shielding member in a first direction for a forward exposure and in a second direction opposite to the first direction for a return exposure. The control unit varies an exposure correction amount of the light shielding member between the forward exposure and the return exposure.