摘要:
In a thermal printer, data in the form of character data separated by gaps is supplied over a data line (38) to a shift register (15). the latched outputs of which cause operation of thermal elements (R 1 -R N ) in a thermal printhead (11 During a test mode of operation, test data is supplied to operate the thermal elements (R 1 -R N ) in succession, a sensing resistor (R s ) providing corresponding test signals which are digitized by an A/D converter (39). Each digitized test signal is compared with an associated initial, stored, digitized test signal, and if the current value deviates by more than a predetermined amount from the initial value, a failure signal is provided. A processor (19) is thereupon effective to cause the subsequent character data to be shifted such that the defective element is aligned with a location which is not used for printing, such as an intercharacter gap. In a modification, the test signals for all the thermal elements (R 1 -R N ) are compared with a common fixed, predetermined reference level.
摘要:
A dot matrix printer in which, for the purpose of supervising the quality of the printing of dot matrix characters, an optical sensor (32) is provided for each dot producing element (11) of a print head (5). Each optical sensor (32) includes two glass fibers (34, 36) to carry light from a light-emitting diode to the surface of a record medium and to carry the reflected light to a photodiode. Each printed dot is detected and the sensor output is compared with a delayed or stored print signal which is applied to the drivers for the dot producing printing elements (11). The print head (5) may either be a wire matrix or an ink jet print head.
摘要:
In a printwheel type of printer using a selection stepper motor (20) for driving the printwheel (18), means are provided for performing printwheel homing operation upon occurrence of predetermined events. Such an event, is detected and reported to microprocessor means (36) which drive motion means (14) for bringing the printer carriage assembly (8) to a first extreme left position where a stop element (58) fixed relative to the printwheel rotation is made to enter the path of another stop element (61) attached to rotate with the printwheel. Subsequently, the selection stepper motor (20) driving the printwheel is driven for a number of steps at least equal to one motor revolution to ensure reaching inhibition of the printwheel rotation by bringing the rotating stop element (58) into contact with the relatively fixed stop element (61 The carriage (8) is then moved back to the left margin writing position where the relatively fixed stop element is withdrawn from the path of the other stop element and the angular printwheel home position is noted and stored by microprocessor means (40).
摘要:
An LED/photodetector structure (54, 34) is disclosed positioned to cooperate with a daisy wheel print element (10) of a daisy wheel printer and a light interrupter (40) such that under microprocessor control, a stepping motor will rotate and home the daisy wheel print element (10), sense the escapement pitch corresponding to that element (10), sense the font weight or impact force level associated with that print element (10) and then cause the carrier to be translated to the left frame, thereby engaging the light beam interrupter (40) with the left frame and forcing it into the light beam indicating the presence or the carrier at a known spacial position for homing of the carrier position. The print element has apertures (20, 24, 26, 28, 30) formed in the hub (22) thereof which are all specialty positioned within one semicircular portion of the print element hub (22) and which denote the home position of the print element (10) -and coded values representing escapement pitch and impact level for that print element
摘要:
Die Erfindung betrifft ein rechnergesteuertes Verfahren zum automatischen Ermitteln des jeweiligen Wertes der Druckqualität eines Druckers und zum Regeln dieser Druckqualität in Richtung auf einen optimalen Wert DQ opt unter Verwendung sowohl des empirisch ermittelten durchschnittlichen optimalen Bildkontrastsignals ( PCS ) als auch der Standardabweichung σ von PCS, das sich aus der Beziehung mit R B = Reflexion des Hintergrundes und R i = Reflexion eines Bildelementes i oder Punktes i (PEL) ergibt, das sich dadurch auszeichnet, daß durch opto-elektronische Abtastung aller Bildelemente i eines Zeichens längs der Skelettlinie und des Hintergrundes der tatsächliche Wert des Bildkontrastsignals aus den Einzelwerten für alle n Bildelemente gebildet und aus diesen n Abtastwerten ein Faktor abgeleitet wird und ein ein Druckqualitätsfaktor und davon 1 n x 2 gebildet wird, daß anschließend daraus der tatsächliche Wert der Druckqualität DQ = a 0 + a 1 1n x 2 ermittelt wird, und daß durch iterativen automatischen Vergleich zwischen dem abgespeicherten optimalen Wert DQ opt der Druckqualität und dem ermittelten Wert der Druckqualität in einer geschlossenen Regelschleife die Regelgrößen zur Nachregelung der verschiedenen Parameter des Druckers abgeleitet und benutzt werden.
摘要:
Imprimante par points dans laquelle, dans le but de controler la qualite de l'impression des caracteres, un detecteur optique (32) est prevu pour chaque element (11) produisant un point dans une tete d'impression (5). Chaque detecteur optique (32) comprend deux fibres de verre (34, 36) servant a conduire la lumiere depuis une diode electroluminescente jusqu'a la surface d'un support d'enregistrement et a conduire la lumiere reflechie jusqu'a une photodiode. Chaque point imprime est detecte et la sortie du detecteur est confrontee avec un signal d'impression retarde ou stocke qui est applique au dispositif d'actionnement des elements (11) d'impression produisant les points. La tete d'impression (5) peut etre soit une matrice a aiguilles soit une tete imprimante a jet d'encre.
摘要:
A function for an electronic typewriter (10) is described. The function assures that when an operator moves the print mechanism back into a region where text has been typed either using a different pitch print element (15) or using a different language keyboard (14), the operation of the typewriter (10) is not enabled until the operator is notified that there exists a condition where a mismatch exists. In the case of the pitch mismatch, the typewriter (10) is only enabled after the operator takes steps to change the print element (15) or position the print point to a position where the mismatch no longer exist. In the situation where a keyboard (14) mismatch exists, the operator must take some step to restart the typewriter operation. This may be the changing of the keyboard (14) to correspond to the keyboard used to key the text in that region, and the changing of the print element (15). The changing of the keyboard (14) may be the only change required, since some languages share print elements.
摘要:
A function for an electronic typewriter (10) is described. The function assures that when an operator moves the print mechanism back into a region where text has been typed either using a different pitch print element (15) or using a different language keyboard (14), the operation of the typewriter (10) is not enabled until the operator is notified that there exists a condition where a mismatch exists. In the case of the pitch mismatch, the typewriter (10) is only enabled after the operator takes steps to change the print element (15) or position the print point to a position where the mismatch no longer exist. In the situation where a keyboard (14) mismatch exists, the operator must take some step to restart the typewriter operation. This may be the changing of the keyboard (14) to correspond to the keyboard used to key the text in that region, and the changing of the print element (15). The changing of the keyboard (14) may be the only change required, since some languages share print elements.