Development of a High Precision Edge Alignment System for Touch-Panel Glass Substrates

Abstract

There are two kinds of alignment systems, marked and unmarked. The glass substrate for touch panels is categorized as an unmarked work piece. Vision based glass substrate alignment (GSA) relies on the edge of the glass. Traditional GSA systems compensate first for angular and then for linear error. This reduces alignment accuracy and increases alignment time and edge detection usually takes longer than 10 ms. This study proposes an effortless edge detection method. This method is very simple and can significantly reduce the time taken to detect the edge to about 6 ms using a 1.3 megapixel image. In this study, a floating center idea is used to control the glass substrate on a high precision coplanar alignment stage. According to the method, users can set the rotation center anywhere as long as it is on the working ( ) plane. Tolerance prognosis is also considered in this study to help the operator decide if the substrate is usable or should be rejected. The experimental results show alignment repeatability of the , , and axes to be 1 m, 1 m, and 5 arcsec, respectively.

Development of a steel ball center alignment device based on Michelson interference concept

“…Since the interference fringes are composed of black and white patterns they can be searched for in a way similar to straight line edge fitting. 17 Using this method a line edge can easily be found in under 10 ms and so we used this method to find the edges of the interference fringes. As seen in Figure 6(a), the fringes are annular and separated into many ROIs (ranges of interest).…”

An improved particle swarm optimization using long short-term memory model for positioning control of a coplanar XXY stage

“…According to kinematic equations, the motors on a coplanar stage can be operated simultaneously to move the stage to the target position faster than a stacked stage can move. 2 Computer vision in has been widely used in imagebased technology. [4][5][6] Vision systems function like the human eye, which can automatically detect and recognize images.…”

“…1 With the development of computers, communications, and consumer electronics, high-precision alignment systems have become increasingly crucial to component manufacturing processes, such as the lamination and electrical testing of touch panels – which involve resistance, capacitance, and linearity parameters – electrical testing for open circuits or shorts, the testing of printed circuit boards (PCB), and the manufacture of light-emitting diodes from wafers. 2 When wafer masks are applied, a precision position platform is used to correctly position and orient the panel. Accordingly, accuracy and quality are crucial to the manufacturing process.…”

“…According to kinematic equations, the motors on a coplanar stage can be operated simultaneously to move the stage to the target position faster than a stacked stage can move. 2…”