LightTools Design Example - Design of Light-Guided Buttons on Car Instrument Panel

LightTools Design Example - Design of Light-Guided Buttons on Car Instrument Panel

LightTools comes with a library of light-enhancing film components and a library of light sources. Its library of light-enhancing film components includes all BEFs and DBEFs of 3M; its light source library includes nearly 400 kinds of LED light sources from the four major LED companies (Agilent, Lumileds, Nichia, Osram), which is very convenient for designing LCDTVs with LED lighting. The dot design of traditional light guide plates is even more convenient, which can simulate both two-dimensional printing dot arrangement and three-dimensional micro-structure laying. Currently, the micro-structure dots include five shapes: sphere, prism, pyramid, cone, and cylinder, which greatly improves the work efficiency of designers.

Cybernet China uses LightTools to design the car dashboard light guide button as follows:
Key points: Use two low-power LEDs to achieve uniform illumination of the three letters on the light guide button.

Design steps
LED light source simulation Geometric
modeling of light-guiding buttons
Setting of material properties and optical properties of geometric models
Setting of light-receiving analysis surface and brightness meter
Ray tracing and result analysis
Modify the geometric model of the button according to the analysis results, and repeat the ray tracing process until the simulation results meet the system design requirements. (Using LT's optimization module can replace cumbersome model changes and shorten the project development cycle)
Here is a brief explanation of the parameters for LED light source simulation. There are detailed parameter settings in the light source model
The following introduces the main parameters (depending on the simulation purpose, the required parameters are also different)

光束(lm)或者是辐射功率(mW)
光谱特性
配光分布
空间強度分布

Definition of light source according to wavelength range

LightTools can set up light sources efficiently and flexibly.
LightTools can propose customized solutions for surface and volumetric light sources.
The Ray Data setting in LightTools can use the light source measured by Radiant Imaging.
The total light energy can be defined in the light source in units of radiometric or photometric energy.
User-defined Aim fields and Aim cones can bring out the best performance.
In order to cooperate with this efficient function, it is planned to define a continuous spectrum in the light source.
LightTools has more powerful built-in modeling capabilities in the geometric modeling of light guide buttons

Through the Solidworks Link module, LightTools completely inherits the feature tree from SolidWorks, providing a familiar design environment for engineers who have used Solidworks. The two-way data exchange function ensures real-time synchronization of features in LightTools and Solidworks.

High-precision simulation results comparison

The picture below is the result of lighting analysis, which corresponds to the illuminance distribution output of the light emitted from the position of the text in the button (light receiving surface). Corresponding to the rectangular diagram in the above figure, different colors are used to represent the size of energy. From the following illuminance distribution diagram, we can analyze that the simulation results of this system basically meet the design requirements.

Monte Carlo ray tracing

Optical simulation can only be performed after the LED light source, button model, and light-receiving surface parameters are set. The simulation uses Monte Carlo ray tracing.