Sensor-Function-Equipped Display, Article, Packaging Material, and Quality Management Method

The purpose of the present invention is to enable a machine-read mark to also determine, with high probability, a management state to be normal when a visual mark has determined the management state to be normal, in cases when the visual mark and the machine-read mark, which are provided with a sensor function for detecting an abnormality in the same management state, are present on one product, even if there is variation in the quality of the marks. At least two barcodes or marks for managing the safety of one and the same product are provided. The barcodes and marks are provided with a function with which the safety of the product is confirmed as a result of a change in a property thereof, such as the color or shape, caused by an external factor that may reduce the safety of the product. The at least two barcodes or marks are provided with the function with which the safety of the product is confirmed as a result of a change in a property thereof caused by the same external factor. The at least two barcodes or marks having properties which change as a result of the same external factor are provided with at least two threshold values which determine that the safety of the same product has reduced.