A low profile optical unit for use in a 2D bar code reader. A vertically disposed light redirecting panel having contoured reflective openings therein is mounted in the front of the unit and an LED behind the panel. Light emitting diodes for illuminating a target are mounted on the LED board behind the contour openings whereby direct light and reflected light illuminates a target. An imager housing is mounted on the back of the LED board and contains a recess that passes through the back of the housing and a lens barrel that extends forward through holes provided in the LED board and the light redirecting panel. An imager board is secured to the back of the housing which holds a 2D imager that is contained within the housing recess. Circuitry for generating image data signals is mounted on the back of the imager board. A lens holder is threadably mounted in the lens barrel which contains a lens system having a short back focal length for focusing a target image on the imager.