Polyimide Aperture Blades in Light Shielding Unit
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Solution Overview
Problem
Conventional light shielding units in camera lens barrels can deform and malfunction when exposed to high temperatures caused by sunlight, leading to issues like melting and sticking of aperture stop blades, which prevents their movement.
Innovation Solution
A light shielding unit comprising a first frame body, a second frame body, and a light shielding portion with opaque movable blades made of polyimide resin, which are designed to prevent heat-related deformations by using a metal cover with high thermal conductivity and polyimide resin components with high heat resistance, along with stepped portions to prevent contact and ensure movement integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional light shielding units are used in the lens barrel, then the device structure is simple and manufacturing is easy, but the units deform and malfunction when exposed to high temperatures from sunlight
Solution Approach 1:
The light shielding unit is divided into multiple independent components: a first frame body, a second frame body, and multiple light shielding portions positioned between them. Each component can be manufactured separately and assembled, allowing the use of heat-resistant materials in critical areas while keeping the overall structure manageable and not excessively complex.
Solution Approach 2:
The patent employs composite material construction by combining metal frame bodies with heat-resistant light shielding portions made of materials that can withstand high temperatures from sunlight. This composite approach enables the light shielding unit to maintain structural integrity and functionality under thermal stress while preserving a relatively simple overall device structure.
2Adaptability or versatility
If the lens is aimed directly at the sun to capture images, then the imaging function is fulfilled, but heat over 100 degrees centigrade is generated inside the lens barrel causing deformation
Solution Approach 1:
The light shielding portions are strategically positioned between the first and second frame bodies to extract and block harmful sunlight before it can penetrate deep into the lens barrel and generate excessive heat. This extraction of harmful radiation allows the imaging function to remain operational while preventing dangerous temperature rises that would cause deformation of internal components.
Solution Approach 2:
The light shielding portions act as intermediary elements between the external sunlight and the internal lens components. These intermediaries absorb or block the harmful solar radiation, preventing direct heating of the lens barrel interior while allowing the imaging system to continue functioning during outdoor photography.
3Ease of manufacture
If plastic movable aperture stop blades are used, then the device is lightweight and easy to manufacture, but the blades deform and stick together when exposed to sunlight heat
Solution Approach 1:
Instead of making the entire aperture stop assembly from heat-resistant material, the patent applies heat-resistant light shielding portions only in the specific locations where sunlight exposure occurs. This localized application of special materials maintains the overall simplicity of manufacturing while protecting the critical aperture stop blades from thermal deformation and sticking.
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 prevents heat-induced deformations and ensures the proper functioning of aperture stop blades even when the camera is pointed towards the sun, maintaining the integrity and functionality of the light shielding unit.
Implementation Method 1
a plurality of opaque movable blades that are formed of a polyimide resin and vary a size of the third opening
Implementation Method 2
designed to prevent heat-related deformations by using a metal cover with high thermal conductivity
Data Source
AI summary
An aperture unit (20) comprises an aperture cover (22), an aperture base (27), and a light shielding portion (24). The aperture cover (22) has an opening (22a) through which light passes. The aperture base (27) is disposed on the downstream side of the aperture cover (22) in the light incidence direction, and has an opening (27a) through which light passes. The light shielding portion (24) is disposed between the aperture cover (22) and the aperture base (27), and has an opening (24d) through which the light that passed through the opening (22a) passes, and a plurality of opaque aperture stop blades (24a, 24b, 24c) that are formed from a polyimide resin and vary the size of the opening (24d).