A display module includes a display, a first polarizer and a second polarizer. Each device includes a limited number of differently designed and dimensioned main and additional modules which provide for a wide range of individually adapted types of devices to be constructed. A peripheral rim may define the aperture of the housing, wherein the first diaphragm may be recessed between about 0. Other embodiments, aspects and features are also disclosed. The thermosensitive recording medium of the present invention that uses a combination of the diphenyl sulfone derivative and a specific phenol derivative in the thermosensitive color developing layer has a good color developing sensitivity and an improved balance among the properties such as moist heat resistance, plasticizer resistance and the like. 1 to 20%; wherein the cationic compounds and anionic surfactants are present in a weight ratio of 1.