Image Sensor Thermal Deformation Compensation
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Solution Overview
Problem
Conventional image capturing apparatuses fail to effectively suppress changes in flange focal length due to heat during shooting and exhibit variations in flange focal length among different apparatuses, as existing solutions like bimetal members require initial height adjustments and have varying thermal deformation amounts.
Innovation Solution
An electronic device with an image sensor unit, a first supporting member, and an adjusting mechanism that includes a thermally deformable member and a biasing member to maintain the imaging surface and reference plane parallel, using bimetal members or ball-based mechanisms to adjust the flange focal length by deforming with temperature changes, and additional adjusting washers to ensure consistent initial adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a bimetal member is installed between the lens holding member and the image sensor holding member to suppress thermal deformation, then the change in flange focal length due to temperature change is suppressed, but the height of the bimetal member in the optical axis direction must be adjusted during initial adjustment and the amount of correction varies among apparatuses
Solution Approach 1:
The patent changes the material parameter by using an invar member (an alloy with extremely low thermal expansion coefficient) instead of conventional bimetal members. This fundamental material parameter change eliminates the need for height adjustment and ensures consistent flange focal length across different apparatuses, as the invar member's thermal deformation is negligible compared to conventional materials
Solution Approach 2:
The patent creates a standardized invar member design that can be replicated across multiple apparatuses. By establishing a uniform invar member structure with specific dimensions and positioning, the flange focal length can be consistently reproduced in manufacturing without requiring individual adjustment of each apparatus
2Reliability
If the housing expands or the image sensor unit deforms due to heat generated during moving image shooting, then the flange focal length changes, but conventional storage of temperature-flange focal length relationship cannot suppress the change during actual shooting
Solution Approach 1:
The patent replaces the conventional software-based or lookup-table-based temperature compensation method with a passive mechanical solution. The invar member's inherent low thermal expansion property mechanically suppresses flange focal length changes during shooting, eliminating the need for complex temperature measurement, calculation, and adjustment systems
Solution Approach 2:
The invar member automatically compensates for thermal expansion effects through its material properties without requiring external control systems. The member passively maintains dimensional stability during heat generation from the image sensor, providing self-service temperature compensation that reduces overall device complexity
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
The solution effectively suppresses changes in flange focal length due to heat and reduces variations among apparatuses by using thermally deformable members to adjust the image sensor's position, ensuring precise and consistent flange focal length across different devices.
Implementation Method 1
a thermally deformable member that is provided between a top end surface of the shaft portion on a side fitted to the hole and a bottom surface of the hole and deforms in accordance with temperature; wherein the thermally deformable member suppresses a change in the first distance due to a change in temperature, by deforming in accordance with temperature
Data Source
AI summary
A first supporting member supports a third supporting member of an image sensor unit that includes an image sensor supported by a second supporting member, and an adjusting member is provided between the image sensor unit and the first supporting member, and adjusts an imaging surface of the image sensor and a reference plane of the first supporting member so as to be parallel to each other at a first distance. A shaft portion of the image sensor unit fits into a hole provided in the second supporting member so as to be slidable in a direction perpendicular to the imaging surface and supports the second supporting member with respect to the third supporting member. A thermally deformable member is provided between the shaft portion and the hole and deforms to suppress a change in the first distance due to a change in temperature.