Bar-code reader having advanced emission-condensing unit

A bar-code reader includes a laser source for emitting a laser beam, and a scan device having reflecting surfaces for scanning a bar code with the laser beam according to a predetermined scanning pattern. A window passes the laser beam from the scan device toward the bar code. A condensing device is provided for condensing reflected light returned from the bar code which passes through the window and is reflected by the reflecting surfaces of the scan device along the route traced by the laser beam. A photosensor is provided for detecting the condensed light and for providing an electric signal in proportion to the intensity of the detected light. A replaceable emission-condensing unit incorporates the laser source, the condensing device, and the photosensor except the scan device and the window, to be mechanically correctly installed.