| 摘要 |
<p>A printing device comprises a platen for supporting items on which text is to be printed, a printing head for printing text, the printing head comprising an array of cells each containing an interchangeable type for printing a respective character, the types being slideable relative to the cells from a rest position to an impression position, the arrangement being such that return of each type towards its rest position from its impression position is effected by its resiliently rebounding from the platen,a trolley carrying the printing head and movable longitudinally relative to the platen between a number of print positions, a print hammer arrangement for propelling the types to their impression positions, a linear motor for causing said relative movement of the platen and trolley and circuitry for controlling the operation of -the impelling means and the drive means. The position of the trolley may be under closed loop control. The printing head may be movably mounted on the trolley for movement in the horizontal and/or vertical directions, optionally by one or more linear motors and optionally with closed loop positional control. Various forms of the printing head, linear motors and print hammers are disclosed.</p> |
