Instrument for writing on X-ray sheets - useful for studying psychological behaviour of children, adults and sick persons, etc.

摘要

Writing instrument comprises a hollow cylindrical housing (10) inside which are a battery (15) and an incandescent bulb (11) of which the latter is displaced against the action of a spring (21) towards one pole of the battery by means of a writing tip (22) containing an optical fibre (27). In this position, the writing tip is in direct contact with the bulb. The writing tip is pref. retained in a holder (24) which is screwed onto one end of the housing of which the other end is closed by a pin including a clip. Writing with this instrument is quick even on foil surfaces.