Preparation method of light diffusion sheet

Abstract

The invention provides a preparation method of a light diffusion sheet. The preparation method includes the following steps: forming a photoresist layer on the surface of the substrate, defining the photoresist layer to have a central area and a peripheral area, the peripheral area includes n first peripheral areas and n+1 second peripheral areas, the first A peripheral region and a second peripheral region are alternately arranged around the central region, n is a natural number ≥ 1; the photoresist layer is sequentially exposed and developed to form a microstructure layer in the central region, and the first peripheral region and the second peripheral area to form an anti-overflow glue structure with grooves, the anti-overflow glue structure surrounds the microstructure layer, wherein the exposure intensity to the central area is less than the exposure intensity to the first peripheral area, and the exposure intensity to the second peripheral area The intensity is less than the exposure intensity for the first peripheral region. Utilizing the above-mentioned anti-overflow structure effectively prevents possible glue overflow when the light diffusion sheet is fixed in the lens, and avoids the influence of the overflow on the optical performance of the device.

Description

technical field [0001] The invention relates to the field of optical technology, in particular to a method for preparing a light diffusion sheet. Background technique [0002] In fields such as TOF depth ranging, it is necessary to use a light diffusion sheet to provide a uniformly emitted surface light source. Such light diffusion sheets need to have micro-nano-scale structural features for sufficient scattering or diffraction of visible-infrared light. Existing micro-nano processing technologies include dry etching, wet etching, photolithography, electron beam etching, nanoimprinting, etc., which can be used to produce light diffusion sheets with micro-nano-scale structural features. The design and manufacturing precision of the light diffuser used for TOF is far lower than that of structured light and other deep ranging schemes that have strict requirements on the spatial distribution of outgoing light. Therefore, light diffusion sheets for TOF are likely to be mass-pro...

AI Technical Summary

Problems solved by technology

[0004] The main purpose of the present invention is to provide a method for preparing a light diffusion sheet to solve the problem in the prior art that the optical performance of the device is reduced due to overflow of glue when the light diffusion sheet is assembled

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