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Using Fiber Optics to Reroute LED (Light Emitting Diode) Light for Low Cost LED Color Vision Testers

IP.com Disclosure Number: IPCOM000007799D
Publication Date: 2002-Apr-24
Document File: 3 page(s) / 1M

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for using fiber optics to reroute LED light for color vision inspection at the board level. Benefits include lower cost and a more reliable inspection.

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Using Fiber Optics to Reroute LED (Light Emitting Diode) Light for Low Cost LED Color Vision Testers

Disclosed is a method for using fiber optics to reroute LED light for color vision inspection at the board level. Benefits include lower cost and a more reliable inspection.

Background

Currently, color vision inspection is conducted by mounting LED cameras at random locations on the board (at primary and/or secondary sites) depending on chassis design. The cameras have x-y motion capability to cover an inspection window up to 18 x 14 inches (maximum board size). To maintain LED color inspection resolution, the inspection window is divided into several small inspection cells for reliable color checking. Using these top, bottom, and side mounted LED cameras, it is difficult to achieve a high beat rate while maintaining a low tester cost. In addition, rapid x-y motion requires high-speed servo motors, while bottom and side mounted LED require additional cameras for inspection.

Figure 1 shows a LED color inspection using multiple top, bottom, and side cameras; the amount of hardware required for this type of inspection greatly increases the cost of the LED color vision tester.

General Description

The disclosed method simplifies color inspection by using fiber optics to reroute LED light from random locations on the board to a fixed inspection window (see Figure 2). The fiber optics are about 0.125 inch in diameter, consisting of a bundle of very small glass fiber strands, each ab...