JPS6155878B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a serial printer, and more particularly, when the current position of the type wheel during printing is different from the designated type position, the hammering operation of the printer is cut and the spacing operation of the carrier is also cut. This makes it possible to reprint correctly.

Serial printers, which are used as output devices for electronic computers, use a carrier to space a type wheel with multiple types at a predetermined printing position, then rotate the type wheel to select the type to be printed. The desired type is printed by striking the type with a hammer against the printing paper on the platen. If an erroneous character is printed, the type wheel is returned to the home position prior to the next character selection operation to prevent erroneous printing of subsequent characters.

Conventionally, the control mechanism for selecting type is as shown in FIG. 4, flip-flop circuit 5, servo amplifier 6, servo motor 7, type wheel 8 rotated by the servo motor 7, home position signal 91, rotation speed signal 92, position signal 93 of type wheel 8 due to rotation of type wheel 8; , a transducer 9 that generates a position pulse 94, a gate circuit 10 that detects a position pulse generated after the current position of the type wheel 8 coincides with a designated character position, and a It consists of a flip-flop circuit 11 for storing data. An input terminal 21 of the subtracter 2 is supplied with a digital position designation signal corresponding to a designated character position on the character wheel 8. Now, if we apply a specified print position signal corresponding to the print character to the input terminal 21 and also add the output of the current print position counter 1 to the other input terminal 22, both output terminals of the subtracter 2 A signal deviation signal appears. This output signal sets the flip-flop circuit 5, and a deviation signal, that is, the position difference between the current character position and the character to be printed, is set in the counter 3. This becomes an analog voltage in the D/A converter 4, and this analog voltage and rotational speed signal 9 of the type wheel 8 detected by a transducer 9;
2, the servo motor 7 is driven to rotate the type wheel 8. As the servo motor 7 rotates, the transducer 9 also rotates, and one position pulse 94 is output every time the print position moves one position, and the current position counter 1 is sequentially output.
is counted up or down depending on the direction of rotation of the type wheel 8, and the counter 3 is counted down. When the type wheel 8 rotates in this way and reaches the designated position, the current position counter 1 indicates the count value of the next type position to be printed, the count value of the counter 3 becomes zero, and the flip-flop circuit 5 is reset with the zero signal. do. By this reset, the contact 12' of the switch 12 is switched from a to b, and the servo motor 7 is stopped at the position where the type position signal 93 becomes 0 [V]. On the other hand, the gate circuit 10 has one input terminal 10b connected to the output side of the flip-flop circuit 5.
is set, the gate is closed. However, when the output of the counter 3 becomes zero and the flip-flop circuit 5 is reset, the gate circuit 10 is opened, and after the current position of the type wheel 8 and the specified type position match, the type wheel 8 is The pulse 94 appears at the output end of the gate circuit 10 through a position pulse 94 that is generated when the signal overruns. Then, at the start of printing, the reset flip-flop circuit 11 is set and its output is inverted to serve as a home position return signal for returning the type wheel 8 to the home position. When this home position return signal is generated, the type wheel 8
returns to the home position, returns the calculated content of current position counter 1 to the value corresponding to the home position (usually zero), and returns counter 3 to the value corresponding to the home position.
After clearing the contents, the above-described character selection operation is repeated and printed using a new specified character position signal.

The above configuration is the same as the invention disclosed in Japanese Patent Application Laid-Open No. 58831/1983, which was previously proposed by the inventor of the present invention. In the conventional print check system configured in this way, for example, if the second character is incorrectly printed as "0223" when it should be printed as "0123",
The third character is printed correctly, and printing errors can be kept to a minimum, but it is difficult to tell which characters are incorrectly printed just by looking at the printing results, making it difficult to recognize correct printing. This will give incorrect information.

On the other hand, as described in Japanese Patent Application Laid-open No. 149418/1983,
For low-speed printing devices, lock the printing wheel and
It has been proposed to detect the lock position at that time, compare it with the print signal, and, if there is a discrepancy, generate an alarm or prevent the hammer from operating. However, although such a configuration may be possible in a low-speed printing device that performs printing by locking the printing wheel, it is necessary to interrupt the hammer operation after the hammer starts operating, as is the object of the present invention. In such high-speed printing devices, it is impossible to reliably block printing.

The present invention aims to solve such problems in high-speed printing devices.According to the present invention, when the current position of the type wheel is different from the designated type position, the hammer operation of the printer is cut. This prevents printing from occurring, and also cuts the spacing of the carrier, stopping the carrier at that position until the next printing is performed. If printing is prohibited by the hammer cut in this way and the carrier is also stopped at that position, the printing position will be blank, so the specified character selection operation will be performed again to print correctly in the blank area. It becomes possible to immediately and automatically correct printing errors.

The present invention has a configuration in which the conventional device described above is combined with the following device. That is, a gate circuit 13 is further provided, one input terminal 13a of which is connected to the output terminal Q of the flip-flop circuit 11, and the other input terminal 13b inputted with a hammer designation pulse which becomes a hammer drive signal during normal printing. do.
The output of the gate circuit 13 becomes a hammer drive signal, which controls the hammer magnet 15 via the magnet driver 14. Generally, to increase printing speed, a hammer drive signal is applied already while the type wheel is rotating to start the hammer operation. Figure 2 shows the position signal 9
3 shows the relationship among the position pulse 94, the output of the flip-flop circuit 5, the hammer drive signal, and the hammer operation of the type wheel. In the figure, the solid line indicates the normal state, and when an overrun occurs due to load fluctuations, inertia of the type wheel, etc., the broken line indicates the normal state. That is, at time T, which is the normal stop position of the type wheel, the flip-flop circuit 5 is reset and the gate circuit 10 is open. Therefore, the subsequent position pulse P passes through the gate circuit 10, sets the reset flip-flop circuit 11, and inverts its output. Therefore, the output terminal Q of the flip-flop circuit 11, which had been kept at logic H and gate circuit 13 open, becomes logic L at that point, closing gate circuit 13 and cutting off the hammer drive signal. Therefore, the hammer, which was in the middle of its operation, returns to its original position before hitting the printing paper on the platen 20, as shown by the broken line, and no printing is performed.

As described above, according to the device of the present invention, the gate circuit is closed by the home position return signal generated when the type wheel malfunctions, the hammer drive signal passing through the gate circuit is cut off, and the hammer is turned off before printing is completed. Since the error area is blanked out, it is easy to identify when a printing error has occurred.
In addition to preventing the provision of erroneous information, there is also no risk of the type wheel being damaged by being struck by a hammer during rotation due to malfunction.

In particular, the present invention includes a space cutting device, as illustrated in FIG. 3, which also cuts the spacing of the type wheel carrier during hammer cutting and stops the carrier in that position until the next printing is performed. If this becomes possible, correct printing will be automatically performed in the blank area by repeating the designated character selection operation, and as a result, correct printing without mistakes will be possible. In the space cut circuit, 16 is a gate circuit for controlling a space destination designation signal, and one input terminal 16a of the gate circuit is connected to a first gate circuit.
The output of the flip-flop circuit 11 in the figure, that is, the home position return signal is provided, and the other input terminal 16b is provided with a space destination designation signal. A destination position counter 17 indicates the position to which the carrier should move, and a current position counter 18 counts position pulses generated by the movement of the carrier to determine the current position. The outputs of both counters 17 and 18 are input to a subtracter 19, and a deviation signal between the two appears as an output, which becomes a space control signal. This space control signal drives the servo motor for carrier movement with the same configuration as the subtraction circuit 2 shown in FIG. It is logic H and the gate circuit 16 is open. However, once the flip-flop circuit 11 is set, its output will be a logic low, gate 16 will be closed, inhibiting the reception of new space destination signals, and the carrier will stop at the same location. Therefore, the type wheel is returned to its original position by the home position return signal, and the hammer cut device according to the invention is also activated to make the type wheel blank. Therefore, if the same specified type selection is performed again and printing is performed, no errors will occur. Printed in modified form.

As described above, according to the present invention, if the current position of the type wheel and the designated type position differ during printing, the hammer operation is interrupted to leave the printing area blank, and space is cut to remove the carrier. movement can be stopped. Therefore, if the designated character selection operation is subsequently repeated and the blank area is correctly printed, correct information without printing errors can be provided as a result, and the reliability of information processing is improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional print check device combined with a hammer cut device according to the present invention, and FIG.
The figure is a timing chart showing the relationship among the position signal, position pulse, output of the memory element, hammer drive signal and hammer operation, and FIG. 3 is a block diagram of a space cut circuit for correcting printing. In the figure, 8 is a print head, 9 is a transducer, 14 is a magnet driver, 15 is a hammer magnet, 13 is a (NAND) gate circuit, 1
6 indicates a (NAND) gate circuit, respectively.

Claims (1)

[Claims] 1. A transducer that generates a position pulse every time the type wheel rotates one type pitch, and generates a home position signal at the home position of the type wheel, A memory element that selects a type by operating the drive motor of the type wheel and transducer according to the deviation from the specified type position, and stores the position pulse after the current position of the type wheel matches the specified type position. outputting a home position return signal when the position pulse is input to the storage element;
In a printer in which the type wheel returns to the home position prior to the next type selection operation, a hammer cut circuit and a space cut circuit are connected to the output side of the memory element, and the hammer cut circuit has a space cut circuit connected to the output side of the memory element. The space cut circuit includes a circuit that receives a home position return signal and a hammer drive signal as inputs, provides the output thereof to a hammer drive circuit, and inhibits hammer operation when the home position return signal is input; A serial printer comprising a circuit that receives an output home position return signal and a space destination designation signal as input, supplies the output to a space control section, and prohibits movement of the carrier when the home position return signal is input. Print correction device.