Brother Kogyo Kabushiki-kaisha

Michio Ueda

Koshiro Yamaguchi

Teruo Imamaki

Takashi Okumura

Shigenori Hattori

Satoshi Shibata

Yoshiaki Yuki

To suppress a secondary bound of a print wire of a dot matrix printer which may occur after a single dot or continuous dots are printed and also to prevent both density variation of printed characters and printing ghost from occurring, a braking pulse is applied after application of a printing pulse in the case of printing the single dot and after a printing pulse of the trailing print cycle in the case of printing the continuous dots. The duration of the braking pulse to be applied after the application of the printing pulse in the trailing print cycle of the continuous dot printing is set to be shorter than the duration of the braking pulse applied after the printing pulse in the case of printing the single dot.

Method of driving wire-dot print head

The dot impact printer of the invention sets an optimum printing speed based on various factors, such as kanji or alphanumeric characters, and to set an optimum brake pulse and an optimum energizing energy corresponding to the set optimum printing speed. The printing mode is determined through a series of logic steps and optimum settings for the printing actions is selected according to the mode identified. Thus, in the invention, based on the print contents, a printing speed, an energizing period of time for the first dot, an energizing period of time for the following dots, a brake pulse width, a period of time till the generation of brake pulses and delay time, are changed.

Printer having a plurality of printing modes

A thermal printer is provided which may use various types of ribbons including print only and print and erase ribbons. The printer includes a memory having stored therein predetermined printing condition data corresponding to a plurality of print modes including a mode in which only printing may be executed and a mode in which both printing and erasing may be executed. One of the modes is selected based upon the type of ink ribbon being used and the printing conditions are set in accordance with the stored data for the selected ribbon.

Thermal printer

A printer wherein printing is effected while a print head and a recording medium are moved relative to each other with the print head in pressed contact with the medium. The printer includes a print-head support member for supporting the print head movably between a printing position and a release position. The printer further includes a support member and a displaceable member which are connected by an elastic member, so that the print head is moved from the release position to the printing position, and the print head in the printing position is pressed against the medium. The displacement of the displaceable member consists of a first movement for moving the print head to the printing position, and a second movement for enabling the elastic member to produce a biasing force for pressing the print head against the medium. An amount of displacement of the displaceable member per unit angle of rotation of the rotatable member is greater in the first movement than in the second movement.

Head-pressure mechanism in thermal printer

A control device is provided for a stepping motor which connects with a drive system comprising a somewhat resilient member exerting a rebound force, such as a gear for the platen or a wire for the carriage in an electronic typewriter. When the stepping motor stops rotating in a determined direction, the control device rotates the stepping motor in the opposite direction for a minimum step to compensate for the unnecessary reverse rotation of the stepping motor caused by the resiliency in the drive system. Therefore, a transmission shaft of the stepping motor is freed from such an undesired external force as the resiliency of other parts and the stepping motor is always stopped in a position appropriate for a subsequent rotation.

Growing community of inventors

Gamagori, Japan

Michio Ueda