A trigger device for staplers includes a trigger pivotably connected to a stapler body and an opening is defined through the trigger. This allows detection of both the gray scale of a print line and the size and colour of an individual dot. The multilayer electronic component has at both ends thereof external electrodes connected to the internal electrode layers, and the thickness of a connected end of the internal electrode layers with the external electrodes is greater than the thickness of a non-connecting end. After the external device is disengaged from the coaxial connector, the second contact portion urges against the first contact portion upwards to form a third relative positional relationship. The fluorescent materials may include phosphor materials and non-phosphor materials such as quantum dots.