Design and fabrication of a micropatterned polydimethylsiloxane (PDMS) light‐guide plate for sheet‐less LCD backlight unit

Abstract

A polydimethylsiloxane (PDMS) light-guide plate (LGP) having micropatterns with an inverse-trapezoidal cross section was developed for a sheet-less LCD backlight unit (BLU). The micropatterned PDMS LGP was fabricated by backside 3-D diffuser lithography followed by two consecutive PDMS replication processes: photoresist-to-PDMS and PDMS-to-PDMS replications. The fabricated LGP showed an average luminance of 2878 nits and a uniformity of 73.3% in a 2-in. backlight module with four side-view 0.85-cd LEDs. It also could feasibly be applied to a light source for flexible displays owing to the flexible characteristic of the PDMS itself. FIGURE 1 -A schematic view of (a) the conventional BLU with three additional optical sheets and one reflector film and (b) the proposed micropatterned PDMS LGP for sheet-less LCD BLU. Journal of the SID 16/2, 2008 329

Miniaturized multicolor fluorescence imaging system integrated with a PDMS light-guide plate for biomedical investigation

“…First, we designed the shape of the light out-couplers so that light could be transmitted to fluorescent samples positioned on top of the LGP between the light out-couplers. The traditional LGP used in BLU of LCD had light out-couplers of inverse-trapezoidal shape, which transmit most of the light in a vertical direction 22 . Therefore, this structure is not suitable for transmitting light to the fluorescent sample positioned between the couplers.…”

61‐3: Glasses‐Free 2D/3D Switchable Display Using a Trapezoidal Light‐Extraction (TLE) Film on the Light‐Guide Plate

“…Then, the patterned film was bonded to the other base film with an optical UV adhesive. A similar inverted trapezoidal pattern was made for a sheet-less LCD BLU with polydimethylsiloxane (PDMS) [11]. Unfortunately, it was difficult to make a large size of this pattern and the process was not cost-effective.…”

Novel buried inverse-trapezoidal micropattern for dual-sided light extracting backlight unit

“…9(b)]. Since the type of the diffuser plate and the index-matching liquid defines the side angle of each hole, the opal diffuser plate and deionized water were selected deliberately in this fabrication process to make the optimized side angle of 55〫 [6,9]. After the SADL process, 12 μm-thick Cu microstructures were grown by electroplating.…”

“…The PIT structure has an inverse-trapezoidal cross-sectional shape and its unique feature is its negatively slanted sidewall. The negatively slanted sidewall reflects light by total internal reflection (TIR) and illuminate to certain direction, thus directionality can be controlled by the inclined angle of the sidewall [6]. However, the PIT microstructure only provides one directional light extraction; therefore it cannot be used directly in a dual-sided light emitting BLU.…”