Imaging Device with Matched-Index Adhesive for Flare Reduction
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Solution Overview
Problem
The proximity of the infrared cut filter to the lens in solid-state imaging elements leads to flare and ghosts due to internal diffuse reflection, which is a consequence of the increased pixel density and device downsizing.
Innovation Solution
The integration of the solid-state imaging element, glass substrate, and infrared cut filter with adhesives having a matching refractive index prevents internal diffuse reflection by standardizing the refractive index across boundaries, thereby minimizing flare and ghosts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If the infrared cut filter is arranged in the vicinity of the lens to achieve downsizing, then the device height is reduced, but flare and ghosts occur due to internal diffuse reflection
Solution Approach 1:
The patent changes the refractive index parameter of the adhesive material to match that of the glass substrate and infrared cut filter. By selecting an adhesive with a refractive index of 1.5 or higher (matching the glass substrate's refractive index of 1.5 or higher), the patent eliminates refractive index differences that cause internal diffuse reflection, thereby preventing flare and ghosts while maintaining compact design
2Device complexity
If the lowermost lens is disposed on the solid-state imaging element to achieve downsizing, then the device configuration is compacted, but the distance between the infrared cut filter and the lens becomes short, causing internal diffuse reflection
Solution Approach 1:
The patent modifies the refractive index parameter of the adhesive layer to be equal to or very close to the refractive index of the glass substrate (both 1.5 or higher). This parameter change makes the adhesive optically invisible, eliminating the internal diffuse reflection interface while allowing the lens to be positioned close to the imaging element for compact configuration
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
This configuration achieves downsizing and reduces device height while effectively preventing flare and ghosts, ensuring high-quality imaging performance.
Implementation Method 1
integration of the solid-state imaging element, glass substrate, and infrared cut filter with adhesives having a matching refractive index prevents internal diffuse reflection by standardizing the refractive index across boundaries
Data Source
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Figure 3A~3B
AI summary
The present disclosure relates to an imaging device capable of preventing occurrence of flare and ghosts. The imaging device includes a solid-state imaging element including a laminate substrate in which a first substrate and a second substrate are laminated, a glass substrate positioned above the first substrate, and a lens formed on the glass substrate, in which a cavity is provided between the lens and the solid-state imaging element. The present technology can be applied to, for example, an imaging device.