| 摘要 |
<p>A dot-matrix printing head includes an array of dot-printing devices (30) operable selectively to cause respective dot-defining portions (4) thereof to impinge on a printing medium to cause respective dots to be printed, each of which devices comprises a laminar flexible member (11), fixed at one end thereof to a support structure (1) of the head and having at its other end the said dot-defining portion (4) of the device. Each device also comprises an electrically controllable actuator (3) operable to impose movement on the flexible member (11) at an actuating position (A) thereon substantially perpendicularly to the main plane of that member so as to bring about such impingement of the dot-defining portion (4) of the device, the distance of the said actuating position (A) from the said one end of the flexible member of the device being small in comparison with the distance of the actuating position from the said dot-defining portion of the device. That region of the flexible member (11) which is between the said one end and the actuating position (A) has the form of at least one truncated triangle. Such a printing head can enable printing operations to be carried out at a desirably high speed and with a satisfactory printing stroke without generation of excessive stress in the component parts.</p> |
