A storage device detector system for use with a gripper assembly for handling storage devices in a storage library system is provided. In one example, the system includes a light source (340) for directing light to an expected position of a storage device, a sensor, e.g., a linear scanner (350), for detecting light, and a controller, wherein the controller and the sensor are adapted to detect the light directed to the expected position of the storage device and determine the presence of the storage device based on frequency components from the sensor. If the frequency is above a predetermined value the system may determine that a storage device is present and if below the predetermined value determine that a storage device is not present.