Printer having print head position sensor and mechanism for inhibiting print head movement when ribbon holder is not in initial position

A printing apparatus, said printing apparatus comprising:

• (a) a platen for supporting a recording medium, (b) a print head for printing on said recording medium within a printing range along a line of printing parallel to said platen, said print head being reciprocable along said line of printing, within a predetermined movement range including said printing range, (c) a head feeding motor for moving said print head along said line of printing selectively in a first direction toward a zero position selected within said movement range and outside said printing range, and a second direction away from said zero position, (d) a ribbon holder for supporting at least one ribbon such that an active portion of each of said at least one ribbon is used between said print head and said platen, (e) a support mechanism for supporting said ribbon holder such that said ribbon holder is reciprocable with said print head along said line of printing and has a plurality of operating positions which are spaced from each other in a direction intersecting said line of printing, said operating positions including a predetermined initial position in which said ribbon holder is placed upon initialization of the printing apparatus, and (f) a position selecting device including an actuator for placing said ribbon holder selectively in one of said operating positions;
• a zero position sensor generating a zero-position signal when said print head is placed in said zero position, and a non-zero-position signal when said print head is spaced apart from said zero position;
• a print head locking mechanism for permitting a movement of said print head from said zero position in said second direction when said ribbon holder is placed in said predetermined initial position, and inhibiting said movement of said print head from said zero position in said second direction when said ribbon holder is not placed in said initial position;
• and
• initializing means for effecting a print head and ribbon initializing operation to move said print head to said zero position and to place said ribbon holder in said initial position, said initializing means:
• applying to said head feeding motor a first zero return signal commanding said feeding motor to operate to move said print head in said first direction to said zero position;
• applying to said feeding motor a first off-zero movement signal commanding said feeding motor to operate to move said print head in said second direction to a predetermined position spaced from said zero position in said second direction;
• and if said zero-position signal remains after said first off-zero movement signal is applied to said feeding motor, repeating a ribbon initializing operation including commanding said position selecting device to operate to move said ribbon holder from a currently selected one of said plurality of operating positions to another, applying to said feeding motor a second off-zero movement signal, determining whether said non-zero-position signal is generated after said second off-zero movement signal is applied to said head feeding motor, and if said zero-position remains after said second off-zero movement signal is applied to said head feeding motor, applying to said head feeding motor a second zero return signal commanding again said head feeding motor to operate to move said print head to said zero position, said initializing means repeating said ribbon initializing operation until said non-zero-position signal is generated as a result of a movement of said print head according to said second off-zero movement signal, said initializing means terminating said print head and ribbon initializing operation when said non-zero-position signal is generated after said second off-zero movement signal is applied to said head feeding motor,
• and wherein said initiating means terminates said print head and ribbon initializing operation if said non-zero-position signal is generated after said first off-zero movement signal is applied to said head feeding motor.