Backlight Support Component for Optical Axis Alignment
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Solution Overview
Problem
Conventional display apparatuses with edge-lit backlight units face misalignment issues between the optical axis of the light source and the light guide plate, leading to decreased central luminance, and the solder connection between the light source and wiring substrate is prone to shear stress, affecting reliability.
Innovation Solution
A display apparatus with a support component that moves between two positions to align and then separate from the light source and light guide plate, minimizing misalignment and shear stress on the solder connection, using a support component with first and second support members to position the optical axes and reduce frictional forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the light guide plate is positioned by contact with the support component, then the optical axis alignment is determined, but dimensional irregularities of the support component cause misalignment between the optical axis of the LED and the optical axis of the light guide plate
Solution Approach 1:
A positioning member is introduced as an intermediary component between the support component and the light guide plate. The positioning member has a positioning protrusion that fits into a positioning groove on the light guide plate, providing a precise mechanical interface that overrides dimensional irregularities of the support component and ensures accurate optical axis alignment.
Solution Approach 2:
The positioning member is pre-installed on the light guide plate before mounting the light guide plate to the support component. This preliminary positioning ensures that the optical axis alignment is established in advance, compensating for any dimensional variations in the support component.
2Manufacturing precision
If both the LED and light guide plate are supported by the same support component, then misalignment of optical axes is minimized, but the soldered portion is subject to shear stress, decreasing dependability of the solder connection
Solution Approach 1:
The support function is segmented into two independent parts: the support component supports the light guide plate for positioning, while the positioning member separately positions the LED relative to the light guide plate. This segmentation allows the LED to be mounted on the wiring substrate without the support component interfering with the solder joint, eliminating shear stress on the solder connection.
Solution Approach 2:
The positioning member acts as an intermediary that establishes the spatial relationship between the LED and light guide plate without requiring the support component to hold both elements. This intermediary positioning mechanism removes the mechanical conflict that previously caused shear stress on the soldered LED.
Data Source
AI summary
A display apparatus includes a liquid crystal panel and a backlight unit that emits light toward the back surface of the liquid crystal panel. The backlight unit includes: an LED; a wiring substrate having the LED mounted thereon; a light guide plate which light from the LED enters through a side surface and exits through a main surface toward the back surface of the liquid crystal panel; and a support component including a first support member that supports the LED and a second support member that supports the light guide plate. The support component is able to move between a first position at which the first support member supports the LED and the second support member supports the light guide plate and a second position at which the first support member is apart from the LED and the second support member supports the light guide plate.