Abstract: An optical reading head system has a calibrated pixel output, consisting of a discrete value for each of a plurality of pixels. The system has a scanning station with an exposure region that includes an image region and a detector including an array of photosensitive sites that sense reflected light from the exposure region during a detector exposure period to generate a pixel output profile of the image region. There are a plurality of light sources for lighting the exposure region. Each light source emits an individually controllable amount of light to the exposure region during a detector exposure period such that the system's pixel output is acceptably calibrated. A calibration medium is supplied with a calibration region, and a target pixel output profile is defined for the calibration. The individually controllable light sources are adjusted to make the pixel output profile acceptably within range of the target pixel output profile.

Abstract: An optical reading head system has a calibrated pixel output, consisting of a discrete value for each of a plurality of pixels. The system has a scanning station with an exposure region that includes an image region and a detector including an array of photosensitive sites that sense reflected light from the exposure region during a detector exposure period to generate a pixel output profile of the image region. There are a plurality of light sources for lighting the exposure region. Each light source emits an individually controllable amount of light to the exposure region during a detector exposure period such that the system's pixel output is acceptably calibrated. A calibration medium is supplied with a calibration region, and a target pixel output profile is defined for the calibration. The individually controllable light sources are adjusted to make the pixel output profile acceptably within range of the target pixel output profile.

Abstract: An automatic digital safety system for controlling the starting and continued energization of one or more internal combustion engines within an engine compartment and for controlling the energization of exhaust blowers in fluid communication with the engine compartment. A guardian control unit disables starter motors and ignition coils of the engines, while simultaneously energizing the exhaust blowers for a first predetermined time interval after their ignition switches are turned ON. Blower sensor circuits sense the energized state of the blowers. Whenever the sensors indicate that the blowers are not energized when enabled, the system disables the engines. After the first predetermined time interval, the engine coils and starters are enabled and the blowers remain energized.