The invention provides an image-sensing device for auto-judging exposure time, which includes a photoelectric sensing element, a measuring unit, and a row-column selector. The controller activates one or more selected pathways in response to information from the detector to regulate energy transfer at a detected region of risk 66 on the mattress. The HBA notifies other Fibre Channel ports of buffer space available in the credit extender. The rotational force device includes a torsion or helical compression spring.