The bar code system plays an important role to automate the postal service. Presently, the bar code system for material handling is used that is modulated in the width. Several height modulated bar code systems are developed and utilized abroad because they are more robust and do not require special printer and papers. In this work, two kinds of the bar code reader that can recognize the height modulated bar code, and are applied to the POSTNET that is used in U.S.P.S. One is for reading the bar code located at the fixed position using the laser and 1D CCD array. This system also includes the signal processing board and PC486. It has the capability to process the letter at the speed of 1.8Hz. Other system processes the 2D images of the letter to separate the bar code from background and recognize the bar code. This system consists of the 2D CCD camera, DSP board and PC486. Although the processing speed is slow at approximately 2.5 seconds per letter, it can recognize the bar code tilted up to 30 degrees.
