Lighting Device Virtual Light Source Optical Element
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Solution Overview
Problem
Conventional solid-state lighting devices struggle to replicate the omnidirectional light spreading of incandescent bulbs while being cost-effective and less complex to manufacture, as they often require intricate optical features or bulky light guides.
Innovation Solution
A lighting device with a light transmissive optical element and envelope that refracts light to create a virtual light source, where the optical element has a thickness increasing towards the base, allowing for increased light distribution in lateral and backward directions without the need for complex manufacturing techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a light guide is used to guide light from the base to create a virtual light source, then omnidirectional light spreading is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent changes the geometric parameter of the optical element by varying its thickness in the vertical direction. The optical element has a thickness that increases toward the base, creating different optical paths for light rays. This parameter change enables the virtual light source effect without requiring complex optical structures or light guides, thereby reducing device complexity while maintaining omnidirectional light spreading.
2Illumination intensity
If an optical feature is provided to create a virtual light source spaced from the base, then lateral and backward light distribution is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The optical element serves multiple functions: it refracts light to create a virtual light source, controls light distribution in lateral and backward directions, and can be manufactured using standard injection molding techniques. By integrating these multiple functions into a single component with a specific thickness profile, the patent eliminates the need for separate optical features or complex assembly processes, thereby improving ease of manufacture while achieving the desired light distribution.
3Temperature
If the light source is attached to the base for heat dissipation, then thermal management is improved, but light spreading becomes more directed (Lambertian pattern)
Solution Approach 1:
The optical element acts as an intermediary between the light source at the base and the surrounding space. It takes the directed light emitted by the base-mounted light source and refracts it to create a virtual light source that appears spaced from the base. This intermediary component transforms the Lambertian light pattern into a more omnidirectional distribution, allowing the light source to remain attached to the base for heat dissipation while achieving improved light spreading.
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 solution enhances omnidirectional light spreading, reduces manufacturing complexity and costs, and improves heat dissipation, while maintaining efficiency by using standard injection molding techniques for the envelope and optical element.
Implementation Method 1
At least a portion of the at least one optical element has a thickness increasing in direction towards the base, said portion being arranged laterally beside the optical axis of the at least one light source so as to refract light emitted by the at least one light source for creating at least one virtual light source spaced from the base
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
A lighting device (1) is provided comprising a base (5), at least one light source (4) arranged at the base, at least one light transmissive optical element (7), and a light transmissive envelope (6) arranged to cover the at least one light source and the at least one optical element. At least a portion of the at least one optical element has a thickness (D) increasing in direction towards the base such that the at least one optical element refracts light emitted by the at least one light source for creating at least one virtual light source (8) spaced from the base. The present aspect is advantageous in that each one of the envelope and the optical element may be manufactured separately, e.g. by standard injection molding technique.