USB scanner, USB system, USB scanner control method, and USB system control method

摘要

PPROBLEM TO BE SOLVED: To provide a USB system allowing limitation of a function while reflecting a user's use form to the utmost even when it is necessary to suppress power consumption on a scanner side on the system. PSOLUTION: When a high power device operation request is rejected by a personal computer (PC) that is a USB host, this scanner makes an LCD display functions depressible or stoppable by limiting the use form among a plurality of functions to exhibit them to the user, and allows selection. The scanner changes setting such that a total of current consumption by combination of the selected functions becomes not more than 100 mA corresponding to a low power device class (steps S1-S11), and newly transmits a low power device operation request to the PC. PCOPYRIGHT: (C)2005,JPO&NCIPI