摘要 |
A container (10), for example a drinks bottle, comprises means of producing an output such as a light signal (13) when the container is opened. Opening the container (10) causes switching of a detector circuit (20) included in the container (10), which in turn causes production of the output signal. Removing a cap (11) of the container (10) may directly close or open a switch (21, 22) within a detector circuit (20). Alternatively the switch (21, 22) may be activated by a change in pressure within the container, or by temperature. The output signal may cause illumination of the contents of the container (10) by an LED (13), or of a label (125) on the container (10), which may be constructed by an electroluminescent device (127) comprising a thin sheet of electroluminescent material. |