摘要:
A drive circuit for driving a wire dot print head including a driving coil (5), a lever (6) for causing a print wire (7) to strike a platen (16) under the action of the driving coil, a spring member (12) for urging the lever (6) to an initial position, and a damper member (13) for absorbing kinetic energy of the lever when it returns to the initial position, comprises a circuit (30, 32, 40, 50) for causing current to flow through the driving coil (5) when the lever (6) is returning to the initial position after having struck the platen (16) in the case where the temperature of the print head is outside a set temperature range. Thus, in operation, a braking force is applied to the lever (6) as it returns to the initial position.
摘要:
The circuit (30) detects variations in the nominal velocity of a character band (11) and adjusts the hammer (22) firing times to compensate for the variations. This circuit (30) measures deviations in band velocity that are either faster or slower than a nominal velocity during each character emitter pulse and makes an appropriate correction in the subscan times that gate the hammer firing signals. A bi-directional counter is counted up at a high frequency to a value representing the emitter period including the velocity deviation and then counted down after the error determination at a selected frequency that is a preselected fraction of the high frequency. This technique corrects for each character emitter pulse and incorporates a timing proportionality to assure correct hammer impact.
摘要:
Un microprocesseur (18) fournit à une source principale d'instructions (22), une mémoire organisée en file d'attente, les différentes instructions (avance papier, frappe marteaux, ...) pour une imprimante représentée par son registre d'instructions (21). Pour chaque instruction de forme (A, C) qui représente un code opération (C) (exemple, un ordre de frappe) pour le marteau d'adresse (A), l'adresse (A) est rentrée dans une source secondaire d'instructions (11), une mémoire organisée en file d'attente, simultanément avec une information temporelle (Y) qui provient d'un compteur binaire de type cyclique (12). Un bit appelé bit de masquage (Z) qui change de valeur à chaque cycle, est également entré, après complémentation avec l'information temporelle (Y). Quand il y a identité entre le contenu (Y, Z) du compteur (12) et celui (Y', Z') disponible en sortie de la source (11), le comparateur (13) indique au contrôleur (14) que l'adresse (A') disponible en sortie de la source (11) correspond à l'adresse d'un marteau à restaurer. Le contrôleur (14) rajoute le code (C=RETOUR) et fournit l'instruction (A', RETOUR) au registre (21). Le contrôleur (14) dispose également de différents moyens de contrôle d'état (vide/plein) des sources d'instructions (11 et 22) et gère les priorités en cas de réception d'instructions contradictoires. Le système (10) permet de retirer au microprocesseur (18) et à ses dispositifs d'entrée/sortie, les commandes de restauration et donc de gagner en temps machine. De plus, le nombre d'instructions à stocker dans la source (22) est diminué de presque moitié.
摘要:
Le circuit de commande de marteau d'impression est commandé par une tension d'alimentation ayant des variations inhérentes de tension. Le courant de commande est appliqué à l'enroulement (30) du marteau d'impression et le niveau de courant dans l'enroulement détecté à l'aide de la résistance (32). Après que le niveau du courant dans l'enroulement ait atteint un niveau maximal prédéterminé, un circuit de chronologie (41) est mis en action pour commander la durée d'application du courant maximal. Les variations de la tension d'alimentation sur la durée et la force de frappe sont réduites de façon importante du fait que la chronologie est basée sur le moment où le niveau de courant de commande prédéterminé est réalisé et n'inclut plus le temps de montée. Les variations d'inductance peuvent aussi être compensées par l'ajustement du circuit de chronologie. Peut être utilisé dans tout type d'imprimante à marteau.
摘要:
In a printing device employing a solenoid (116) for driving a printing hammer (110), provided are switching member (126) for ON/OFF operating electric current flowing through the solenoid coil (116), voltage generating member (128) for generating voltage in accordance with the electric current, converting member (130) for converting the generated voltage to a digital value, chopping member (134) for comparing the converted digital value with a predetermined comparison value, while for turning on the switching member (126) when the converted value is smaller than the predetermined comparison value and turning off the switching member (126) when the converted value is larger than the predetermined comparison value, another chopping member for alternatively turning the switching member in another predetermined interval shorter than the predetermined interval, when the set value becomes similar to the comparison value, during said predetermined interval. Thus, the current deviation at each of the solenoid driving period are controlled to be limited in the desired range.
摘要:
The trajectory of an electromagnetic actuator is adjusted by pulse-width-modulating feed-back control of the waveform which energizes the coil. As applied to actuators for impact printing, the objectives of the control- scheme are to regulate the armature's time of flight and its velocity at impact, in spite of disturbances, thereby to provide higher-quality printing at increased speed. Each actuation is produced by energizing the coil with a series of pulses. Regulation is accomplished under microprocessor control by measuring the state variables of the system -armature position, armature velocity, and coil current -at the beginning of each pulse, comparing these measurements to ideal values, and modulating the width of the pulse as a function of the errors. In general, the appropriate functional relationship between the measure errors and the pulse-width modulation is nonlinear, and is different for each pulse in the series. Systematic means for determining these relationships are given.
摘要:
The trajectory of an electromagnetic actuator is adjusted by pulse-width-modulating feed-back control of the waveform which energizes the coil. As applied to actuators for impact printing, the objectives of the control- scheme are to regulate the armature's time of flight and its velocity at impact, in spite of disturbances, thereby to provide higher-quality printing at increased speed. Each actuation is produced by energizing the coil with a series of pulses. Regulation is accomplished under microprocessor control by measuring the state variables of the system -armature position, armature velocity, and coil current -at the beginning of each pulse, comparing these measurements to ideal values, and modulating the width of the pulse as a function of the errors. In general, the appropriate functional relationship between the measure errors and the pulse-width modulation is nonlinear, and is different for each pulse in the series. Systematic means for determining these relationships are given.