Patent ID: 7568851

Claim:
A system, comprising: a sheet package including sheets as print mediums and a package member surrounding the sheets stacked up; and a printer using the sheet package, wherein: the printer includes a sensor, the sheet package is configured so that the sheets can be set in the printer together with the package member exposing part of the sheets, the package member being provided with an identification mark so that the identification mark will be placed in a reading area of the sensor of the printer only when the sheet package is set in the printer in a correct direction, the printer operates depending on whether the identification mark can be read by the sensor or not; the printer is configured to inform a user of an error when the identification mark can not be read by the sensor; and the printer is configured to regulate its sheet feed operation when the identification mark can not be read by the sensor, wherein the sheet package includes a plurality of error marks that each cause the sensor to detect an error, the error marks respectively formed at every part of the sheet package or the sheets that can be placed in the reading area of the sensor when the sheet package is set in the printer in an incorrect direction, the error mark being formed by a plurality of indicator bits indicating the same information, and wherein the printer is configured to inform the user of an error and regulate its sheet feed operation when all the sensors read the same value.