Interchangeable Lens Focus Scale Segmentation for Consistent Manual Focusing
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Solution Overview
Problem
Existing camera lens systems, especially in professional cinematography, face challenges in ease of use and accuracy when changing and focusing lenses due to compact designs and varying focal lengths, leading to difficulties in aligning focus distance marks and requiring different focusing actions or gearing for different lenses.
Innovation Solution
The design features interchangeable lenses with a focus scale and index mark arrangement that allows for consistent focusing across lenses of different focal lengths by dividing the focus scale into two sub-ranges, with the principal sub-range from infinity to 2m (6 feet) requiring the same relative movement for all lenses, enabling similar ergonomics for manual focusing and consistent gearing for mechanical focusing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the lens system is made compact with smaller circumference, then portability and ease of handling are improved, but the focus distance marks become compressed and alignment accuracy deteriorates
Solution Approach 1:
The focus scale is divided into two distinct sub-ranges: a first sub-range for distant focus distances and a second sub-range for close focus distances. This segmentation allows each sub-range to be optimized independently, with the second sub-range providing expanded spacing for close focus distances to improve alignment accuracy despite the compact lens circumference.
2Adaptability or versatility
If different focal length lenses are used, then versatility and adaptability are improved, but the focusing action and gearing requirements vary, increasing operational complexity
Solution Approach 1:
The focus scale design provides universal focusing operation across multiple lenses of different focal lengths. By configuring the second sub-range to extend over at least 180 degrees of rotation for all lenses, the patent ensures that manual focusing and mechanical gearing remain consistent regardless of which lens is attached to the camera body.
3Adaptability or versatility
If the focus scale covers the entire range from infinity to close focus, then complete focus coverage is achieved, but the marks for close focus distances become too compressed to align accurately
Solution Approach 1:
The focus scale is divided into two distinct sub-ranges: a first sub-range for distant focus distances and a second sub-range for close focus distances. This segmentation allows each sub-range to be optimized independently, with the second sub-range providing expanded spacing for close focus distances to improve alignment accuracy despite the compact lens circumference.
Solution Approach 2:
The patent uses angular rotation as a dimension to expand the effective spacing of focus distance marks. The second sub-range extends over at least 180 degrees of rotation, utilizing the rotational dimension to provide sufficient separation between close focus distance marks for accurate alignment, even when the linear circumference is limited.
Data Source
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AI summary
A plurality of interchangeable lenses is provided, any one of which can be attached to a camera housing for capturing an image. Each lens has a focal length that differs from the focal length of the other lens or each other lens. Each lens has a focus scale a focus index mark, so that the lens can be focused at a desired focus distance by relative movement of the focus scale and the focus index mark. The focus scale is divided into at least two sub-ranges. One of the sub-ranges is a principal sub-range that extends from a focus distance of infinity to a focus distance of 2m (six feet), wherein the relative position of the focus scale and the focus index mark that is required to focus the lens at any focus distance within the principal subrange is the same for at least two lenses.