Laundry treatment machine and control method thereof

A laundry treatment machine comprising:

• a top cover configured to have a laundry entrance hole through which laundry is put in or taken out of the laundry treatment machine;
• a lid assembly configured to be disposed above the top cover so as to be rotatable, the lid assembly opening or shutting the laundry entrance hole;
• a lock device configured to include a lock element and a lead, the lock element locking or unlocking the lid assembly and the top cover, and the lead moving in the same direction as the lock element;
• and
• a device driving unit configured to detect a position of the lead, determine an operating state of the lock device based on the detected position of the lead, and control an operation of the lock device,
• wherein the device driving unit includes a device controller which, if the lock element is moved from its initial unlock position to a lock position where it can lock the lid assembly and the top cover, receives an initial detection signal, and if a first detection signal is not received within a first setting time of the receipt of the initial detection signal, the device controller determines that the lid assembly and the top cover are not properly locked, and outputs first error information,
• wherein the device controller controls the lock device for the lock element to move from the lock position to a maximum position after the receipt of the first detection signal,
• wherein even if the first detection signal is received within the first setting time of the receipt of the initial detection signal, the device controller outputs second error information if no other detection signal is received within a second setting time of the receipt of the first detection signal,
• wherein the lock device includes a common contact which is contacted by an upper portion of the lead, an initial contact which is contacted by a lower portion of the lead when the lead is located at its initial position, and a second lock contact which is contacted by the lower portion of the lead when the lead is located at the lock position,
• wherein the device driving unit further comprises a position detector, which outputs the initial detection signal if the upper and lower portions of the lead contact the common contact and the initial contact, respectively, and outputs the first detection signal if the upper and lower portions of the lead contact the common contact and the second lock contact, respectively,
• wherein the position detector if the lock element is moved from its initial unlock position to the lock position where it can lock the lid assembly and the top cover, determines whether the lead is moved from its initial position to the lock position and outputs the first detection signal as the result of the determination,
• wherein the device controller determines that the lid assembly and the top cover are not locked and outputs the first error information if the first detection signal is not received from the position detector, and
• wherein the device controller if no other detection signal is received within the second setting time of the receipt of the first detection signal, determines that the lid assembly and the top cover are detached from each other and outputs the second error information including detachment information.