Abstract: An image forming apparatus in accordance with the present invention includes a vibration sensor that transmits a detection signal in response to a vibration pattern and a sheet feeder cassette unit that stores recording papers, is opened/closed by extraction/insertion, and generates a specific vibration pattern while being opened or closed. The image forming apparatus includes an open/close detector unit that detects an opened/closed state of the sheet feeder cassette unit when detecting a predetermined vibration pattern based on the detection signal of the vibration sensor.

Abstract: An image forming apparatus in accordance with the present invention includes a vibration sensor that transmits a detection signal in response to a vibration pattern and a sheet feeder cassette unit that stores recording papers, is opened/closed by extraction/insertion, and generates a specific vibration pattern while being opened or closed. The image forming apparatus includes an open/close detector unit that detects an opened/closed state of the sheet feeder cassette unit when detecting a predetermined vibration pattern based on the detection signal of the vibration sensor.

Abstract: An operation input device according to the present invention displays a plurality of keys (7) on a liquid crystal panel (6), and prompts a user to press the keys (7) in the order of numbers assigned to the respective keys (7). On the basis of key pressing periods during which the respective keys (7) are pressed, the characteristics of a key input operation performed by the user (the average and standard deviation of the pressing periods) are detected, and judgment reference values are determined on the basis of the detected characteristics for judgment of the type of the user's key input operation (an ordinary key input operation, a longer pressing key input operation or a double click key input operation). When a key input operation is performed, the type of the key input operation is judged on the basis of the judgment reference values thus determined, and a process according to the judged key input operation type is performed.

Abstract: An operation input device according to the present invention displays a plurality of keys (7) on a liquid crystal panel (6), and prompts a user to press the keys (7) in the order of numbers assigned to the respective keys (7). On the basis of key pressing periods during which the respective keys (7) are pressed, the characteristics of a key input operation performed by the user (the average and standard deviation of the pressing periods) are detected, and judgment reference values are determined on the basis of the detected characteristics for judgment of the type of the user's key input operation (an ordinary key input operation, a longer pressing key input operation or a double click key input operation). When a key input operation is performed, the type of the key input operation is judged on the basis of the judgment reference values thus determined, and a process according to the judged key input operation type is performed.