LCD Bead Spacer Printing Apparatus with Recessed Plate

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Solution Overview

Problem

Existing LCD manufacturing processes face challenges with bead spacers, as they can be randomly distributed, leading to light leakage, increased production costs due to additional photolithography processes, and reduced elasticity, causing liquid crystal filling errors and panel damage. Additionally, columnar spacers require separate photolithography, increasing costs and reducing the margin for errors.

Innovation Solution

A precision printing apparatus using a planar printing plate with recesses and a rotating cylindrical transfer roller to deposit bead spacers at selected locations on LCD substrates, preventing multi-layer deposition and ensuring uniform spacing, which includes a mixture of bead spacers and a thermosetting or UV-curing binder, and uses a laser to form recesses on the printing plate for efficient ink distribution and transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If bead spacers are used to avoid additional photolithography process, then production cost is reduced, but bead spacers can be randomly distributed causing light leakage and deterioration of light contrast

Engineering Contradiction:

Improveproduction costVSAvoidlight leakage

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The printing plate has recesses formed at specific locations corresponding to light blocking members, creating localized spacer deposition zones. This ensures spacers are placed only in non-light-transmitting areas, preventing light leakage while maintaining the cost advantage of bead spacers without photolithography

Inventive Principle:

Principle #3Local quality

2Strength

If bead spacers are used instead of columnar spacers, then elasticity is improved and margin for liquid crystal filling errors is increased, but bead spacers may be deposited in stacked layers causing substrates to be spaced too far apart

Engineering Contradiction:

ImproveelasticityVSAvoidspacer layer thickness

Core Design Contradiction:

StrengthVSManufacturing precision

Solution Approach 1:

The recesses are pre-formed in the printing plate with controlled depth and geometry. This preliminary structure guides the ink and bead spacer deposition, ensuring that spacers are deposited in a single layer at the correct thickness without stacking, while maintaining the elasticity benefits of bead spacers

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent replaces the photolithography-based columnar spacer formation with a mechanical printing system using a printing plate with recesses. This substitution achieves precise single-layer spacer deposition through the physical structure of the printing plate rather than chemical photolithography processes

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Object-affected harmful factors

If columnar spacers are used to achieve regular pattern distribution, then light leakage is prevented, but additional photolithography process is required increasing production cost

Engineering Contradiction:

Improvelight leakageVSAvoidproduction cost

Core Design Contradiction:

Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

Enables precise, cost-effective deposition of bead spacers at selected locations, preventing light leakage and ensuring uniform cell gap maintenance, while reducing production costs and enhancing the elastic force between substrates, thus improving LCD panel quality and yield.

Implementation Method 1

uses a laser to form recesses on the printing plate for efficient ink distribution and transfer

Methodology Applied

Scientific EffectLaser ablation: Laser Ablation

Implementation Method 2

a mixture of bead spacers and a thermosetting or UV-curing binder

Methodology Applied

Scientific EffectThermosetting:

Implementation Method 3

a mixture of bead spacers and a thermosetting or UV-curing binder

Methodology Applied

Scientific EffectUV-curing: Photopolymerisation

Data Source

PatentUS7724342B2Apparatus and method for printing bead spacers on a liquid crystal display substrate comprising a planar printing plate having recesses including a radial protrusion disposed at center

Publication Date: 2010.05.25 SAMSUNG DISPLAY CO LTD

AI summary

An apparatus for printing bead spacers at selected locations on an LCD substrate includes a cylindrical transfer roller and a printing plate having a plurality of semispherical recesses respectively located at positions corresponding to the selected locations of the spacers on the LCD substrate. A volume of an ink containing the spacers is loaded into each of the recesses, and the substrate is translated tangentially relative to the rotating transfer roller such that the volumes of ink are transferred onto the roller. A support plate having the LCD substrate mounted thereon is then translated tangentially relative to the roller such that the volumes of ink on the roller are transferred onto the surface of the LCD substrate at the selected locations. The apparatus enables the spacers to be printed onto the LCD substrate accurately and inexpensively, and prevents the spacers from being inadvertently printed in double layers.