Password input method

A password input method, being conducted by a microprocessor of a touch sensitive password input device, wherein the touch sensitive password input device comprises a touchscreen and a circuit that comprises a memory and the forgoing microprocessor, and there being a table recorded with a plurality of sequentially-ordered pre-determined numerals stored in the memory, each of the pre-determined numerals having a sequentially ordered number and a reference displacement thereof, and one of the plurality of sequentially-ordered pre-determined numerals being designated as a first numeral so as to make a summation of at least one reference displacement be equal to a pre-determined displacement the password input method comprising the following steps:

• (1) monitoring a touch position during a finger touching the touchscreen by using the touchscreen and the microprocessor;
• (2) in case of the finger moving on the touchscreen, recording a finger displacement and a displacement vector corresponding to the finger displacement by using the microprocessor;
• (3) applying a data process to the finger displacement so as to obtain an input numeral by using the microprocessor;
• (31) calculating a quotient by dividing the finger displacement by the pre-determined displacement by using the microprocessor;
• (32) in case the quotient is equal to 1, the first numeral being determined by the microprocessor, and then storing the first numeral as the input numeral in the memory by using the microprocessor as well as controlling the touch sensitive password input device to output a first indication signal by using the microprocessor;
• (33) determining whether the touch position is fluctuated by using the touchscreen and the microprocessor;
• if yes, going to step (4);
• otherwise, going to step (34);
• (34) recording a fluctuated finger displacement and a fluctuated displacement vector corresponding to the fluctuated finger displacement by using the microprocessor, and calculating a fluctuated quotient by dividing the fluctuated finger displacement by the pre-determined displacement by using the microprocessor;
• (35) applying a vector dot product operation to the displacement vector and the fluctuated displacement vector by using the microprocessor, thereby obtaining a value;
• (36) determining whether the fluctuated quotient is equal to or greater than 1 by using the microprocessor;
• if yes, going to step (37);
• otherwise, going back to the step (1);
• (37) in case the value is equal to or greater than 0, selecting one pre-determined numeral from the table as a second numeral according to the fluctuated quotient, wherein the second numeral having a sequentially ordered number greater than that of the first numeral, and then storing the second numeral as the input numeral in the memory by using the microprocessor as well as controlling the touch sensitive password input device to output the first indication signal by using the microprocessor;
• (38) in case the value is less than 0, selecting one pre-determined numeral from the table as a third numeral according to the fluctuated quotient, wherein the third numeral having a sequentially ordered number lower than that of the first numeral, and then storing the third numeral as the input numeral in the memory by using the microprocessor as well as controlling the touch sensitive password input device to output the first indication signal by using the microprocessor;
• (4) determining whether the finger double clicks the touchscreen;
• if yes, going to step (5);
• otherwise, going to step (7);
• (5) recording the input numeral as one of multiple designated numerals belong to a specific password, and then determining whether the multiple designated numerals are all recorded;
• if yes, going to step (6);
• otherwise, going back to step (1);
• (6) controlling the touchscreen to show a virtual confirm button by using the microprocessor, and then using the touchscreen and the microprocessor to determine whether the virtual confirm button is clicked;
• if yes, going to step (8) after controlling the touch sensitive password input device to output a second indication signal by using the microprocessor;
• otherwise, going back to step (1);
• (7) controlling the touchscreen to show a virtual cancel button by using the microprocessor, and then using the touchscreen and the microprocessor to determine whether the virtual cancel button is clicked;
• if yes, ending the steps after controlling the touch sensitive password input device to output a third indication signal by using the microprocessor;
• otherwise, going back to step (1);
• and
• (8) the multiple designated numeral belong to the specific password being all recorded by the microprocessor, such that a password input operation is completed.