Lens Illumination Device Circular Light Guide Uniform Macro Photography
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Solution Overview
Problem
Existing macro lenses for close-up shooting face challenges in achieving uniform illumination without increasing the number of light sources, as light from xenon flash tubes is instant pulsed and difficult to visually check, and previous LED-based solutions require numerous light sources or struggle with uniformity due to short intervals.
Innovation Solution
A lens apparatus with a light guide member having a circular optical path for internal reflection and a light source arrangement where the normal direction of the light emitting surface faces the tangential direction of the light guide member, allowing for uniform illumination with a smaller number of light sources, using white light emitting diodes and a diffuser plate for optimal light distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If light sources are arranged with short intervals to illuminate the object, then illumination coverage is improved, but uniformity of illumination deteriorates
Solution Approach 1:
A light guide member is introduced as an intermediary between the light source and the object. The light guide member receives light from the light source and redistributes it uniformly across the object surface through its optical path, eliminating the need for multiple light sources arranged in close intervals while achieving both coverage and uniformity.
2Manufacturing precision
If multiple light sources are arranged to achieve uniform illumination, then illumination uniformity is improved, but device complexity increases
Solution Approach 1:
The light guide member serves as a mediator that replaces multiple light sources. Instead of using several light sources arranged in specific patterns, a single light source coupled with the light guide member achieves uniform illumination through the optical path design of the guide member.
Solution Approach 2:
The light guide member performs multiple functions: it guides light from the source, distributes it uniformly across the object surface, and controls the angular distribution of emitted light. This multi-functionality eliminates the need for complex arrangements of multiple specialized light sources.
3Illumination intensity
If light sources are arranged facing the optical axis direction, then illumination intensity is improved, but number of light sources increases
Solution Approach 1:
The light guide member acts as an intermediary that modifies the light path. Light from a single source arranged in a specific direction enters the light guide member, which then redistributes it to achieve uniform illumination intensity across the object surface without requiring multiple sources facing the optical axis.
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 achieves uniform and constant angular illumination in close-up shooting with a reduced number of light sources, effectively addressing the limitations of previous technologies by ensuring even light distribution across the object.
Implementation Method 1
a light guide member that has a circular optical path in which light is subjected to internal reflection to propagate
Data Source
AI summary
A lens apparatus includes an image pickup optical system; a holding frame to hold the image pickup optical system; and an illumination device that is mounted on outer peripheral portion of an object side of holding frame, and is configured to radiate light, in which the illumination device includes: a light guide member that has a circular optical path in which light is subjected to internal reflection to propagate, and a light emitting surface for emitting light to object side; and a light source that is arranged such that a normal direction of a light emitting surface of the light source faces a tangential direction of a circle of light guide member, and is configured to emit light entering the light guide member. The arrangements and shapes of holding frame, light guide member, and lens closest to object side of image pickup optical system are each appropriately set.