Abstract: An object is to reduce the complexity of an operation and precisely detects a jam occurrence. A mark sensor detects an end portion of a label pasted on a print target medium that is long paper and being conveyed. A control section acquires, based on a difference between a time point at which an end portion of a first label has been detected by the mark sensor and a time point at which an end portion of the next label has been detected by the mark sensor, an interval between the labels, and takes this interval as a reference point. Then, the control section judges whether an interval between labels detected by the mark sensor is more than the reference interval and, when it is more than the reference interval, judges that the conveyance of the paper has been stopped.

Abstract: A power supply control apparatus directs a switching device to stop power supply from a first power source to a main body when a power supply disable condition is satisfied in a first state where the main body is powered by the first power source. The power supply control apparatus also directs the switching device to supply power from the first power source to the main body when a power supply enable condition is satisfied in a second state where the power supply from the first power source to the main body is stopped. The power supply control apparatus is powered by a second power source different from the first power source when the main body is in the second state.

Abstract: A power supply control apparatus directs a switching device to stop power supply from a first power source to a main body when a power supply disable condition is satisfied in a first state where the main body is powered by the first power source. The power supply control apparatus also directs the switching device to supply power from the first power source to the main body when a power supply enable condition is satisfied in a second state where the power supply from the first power source to the main body is stopped. The power supply control apparatus is powered by a second power source different from the first power source when the main body is in the second state.

Abstract: A sales data processing system wherein an upper limit value, a lower limit value, and a tax amount are entered into a tax amount list. The upper limit value and the lower limit value define a predetermined range of sales amounts, and the tax amount is determined based on a sales amount defined within the predetermined range. Difference values are calculated between a presently entered one of the upper and lower limit values and a previously entered one of the upper and lower limit values, and the calculated difference values are stored in accordance with a calculation order. A first difference value series not having regularity is judged, and a second difference value series having regularity repeated in a predetermined pattern from a series of the stored difference values is also judged.