Adaptive Login State Control via Human Body Detection

The patent applies dynamics by making the logout timing adaptive rather than fixed. The system dynamically determines whether to execute automatic logout based on the relationship between the actual absence period and a predetermined threshold. When the absence period is shorter than the threshold (even if errors occur), logout is suppressed, preserving user convenience. When the absence period exceeds the threshold, logout is executed to maintain security. This dynamic adjustment resolves the contradiction between security and convenience.

The patent applies parameter changes by introducing a time threshold parameter that controls the login state maintenance duration. The system monitors the absence period and compares it against the predetermined threshold. As long as the absence period remains below the threshold, the login state is maintained regardless of errors, improving convenience. When the threshold is exceeded, the system changes the state parameter to execute logout, thereby maintaining security. This parameter-based control resolves the contradiction between convenience and security.

The patent applies preliminary action by pre-storing the user ID in the control unit before displaying the simplified re-login screen. When the user returns and operates the re-login key, the system already has the user ID ready, eliminating the need for the user to re-enter it. The authentication process then proceeds with the pre-stored ID and only requires verification of the password or other factors. This preliminary preparation of authentication data simplifies the re-login process while maintaining security through proper authentication verification.