DE2326798A1 - CONTROL DEVICE FOR THE PRINT HEAD OF A SERIES PRINTER - Google Patents

Description

Patent attorney DIPL.-PHYS. DR. W. LANoHOFF Attorney B. LANGHOFF *

MUNICH 81 · WISSMANNSTRASSE 14 · TELEPHONE 932774 · TELEGRAM ADDRESS: LANGHOFFPATENT MUNICH

Munich, May 25, 1973 Our reference: 45-1237

Societe Logabax Sr *, l46 _s Champs-Elysees, 75 -. Paris 8 ^e,

(France)

Control device for the print head of a serial printer

The invention relates to a control device for the print head a mail merge.

In the case of known mail merges, the Print head in relation to the paper by a stepper motor to print the individual characters one after the other, Each drive pulse of the stepping motor advances the print head one character width according to the distance two consecutive characters. This causes the printhead to partially or completely cover the last characters printed while waiting for the command to print another character "-

Another disadvantage of the known serial printer is that the operator has a sequence of Space can only be achieved by pressing the relevant space bar as many times as the stride lengths in the relevant empty space are included. This is tedious and very tiring with larger empty spaces.

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The invention is based on the object of creating a control device of the type mentioned at the outset which. avoids these disadvantages and practically does not result in any obstruction of the printed text.

The solution to this problem is essentially given by a memory assigned to the print head, by a buffer register with an input for the successive input of digitally coded characters and with an output, from to which the characters are forwarded to the memory, by a display device for continuously displaying the address in the buffer register of the last in the input of the same given character and the first character ready for transmission to the output, by a comparator to the constant comparison of these addresses, by a sequence control circuit to enable the input of a character the input or the transmission of a character to the output depending on the status of the! Comparator a memory device for the position of the printhead in a line at each point in time at which the addresses match, and for controlling the return of the print head to the beginning of the relevant line, and by a control device to control the speed of the printhead until it exceeds the aforementioned position when entering further Sign after a coincidence of the addresses. Such a device allows on the one hand the asynchronous output of alphanumeric characters regardless of the rhythm of receipt of the same, the characters between zero and a maximum value and, on the other hand, a pseudo-incremental function of the print head without using a stepping motor .

According to a particular embodiment of the invention hears the printhead moves forward when there is no more new character to be printed, and after the last position " has been noted is automatically added to the beginning of the line.

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returned without the line feed being operated, so that the printed characters are easily legible.

According to a further feature of the invention, the print head takes' resumes forward immediately after entering one or more characters for printing, where it skips over the already printed area of the line at maximum speed and then the newly entered .Character prints.

It is also provided that a repetition of a sequence of spaces does not require repeated entry for each individual space, only the number of spaces, which further increases printing speed.

The invention is described below with reference to schematic drawings described in addition to several exemplary embodiments.

Figure 1 shows the detection and printing of the characters.

Figure 2 shows a special case in which a character on several consecutive spaces follows.

Figure 3 shows a preferred embodiment of a Control device according to the invention.

Figures 4 and 5 show two different possible uses of the control device according to the invention. ₍

The storage register 101, which is used as a buffer, emulates an essential part of the control device the invention. FIG. 1 shows a number of memory units which each accommodate a group of 8 bits

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which form an octet and are located by the addresses a, b, c, d, e etc.

In the figure it is assumed that each memory position in the series of data acquisition has received the characters A, B, C and D, the individual consecutive characters can of course be separated from each other by any time interval.

Two display devices are assigned to the storage register 101, namely an input display device 102 and an output display device 103, which the address of the Determine the character entered last or the address of the character output first, i.e. for the special one Embodiment according to Figure 1, the addresses d and a of the characters D and A. It follows that each time a new character is input into the memory register 101, the input display device 102 advances one step to the right and that each time a new character is output, the output display device 103 is independent is switched one step to the right by the input display device. If the Characters A, B, C and D 'are entered into the storage register 101 which form the word ABCD, the input display device 102 successively shows the addresses a, b, c and d.

Assuming that the printhead is in a correct position, the output indicator 103 initially indicates the position 101a in the memory register 101 and enables the output of the character A. Then sign after sign continued as a function of the step speed of the print head, with the positions 101b, 101c and lOld of the memory register 101 and the output of characters B, C and D is enabled. Once the position lOld is denoted by the input display device 102,

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the word ABCD is output. At this point in time, the circuits control the control device, according to the Invention of the return of the print head to the beginning of the line, while the address of the last output character D is stored in an auxiliary memory so that the print head can resume advancing immediately after a new character has reached the position where it was should be output. This is done by creating a number of spaces equal to the content of the auxiliary memory (Memory device).

As will be explained further below, the addresses contained in the two display devices are determined by the content determined by two auxiliary memories, and the comparison of these both contents enables the acquisition or the output of characters in or from the memory.

The various positions of the memory register 101 are of course not permanently occupied. You will every time free when a new character is output. Special facilities are provided for the output, of To block characters when the buffer register is empty and to block the acquisition of characters when the Buffer register is occupied, which is equivalent to limiting the displacement of the two display devices 102 and 103 in Figure 1.

Figure 2 shows another possibility in which the output of a word or a character after a number of Space takes place. As can be seen from FIG. 2, before the output of the character Z η = 19 spaces are inserted, starting from the beginning of the line. One leads in the consecutive positions of the storage register 101 first "tabulate" the code, as in FIG. 2a is drawn, then the number of spaces in front of a character to be output (here the 20th position)

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decreased by one unit, which is 19 consecutive Corresponds to spaces. This number is converted to binary code and finally the code of the character, such as Z, ■ issued. The successive analysis of the contents of the successive positions of the storage register according to FIG. 2b, the output display device results in a shift of the print head from the beginning of the line up to the position where the character Z should be printed, this is the 20th position.

This feature of the control device according to the invention gives the advantage that a number of places are saved in the memory that would otherwise be used for successive generation of several tab codes would be required, and that at the same time the character acquisition speed is incremented for the following characters.

FIG. 3 shows a preferred embodiment of a control device according to the invention.

The memory register 301 is e.g. a memory with direct access for 256 groups of eight. The AE and AS are through the input display device 102 and the input display device 103 from FIG. 1 and are identified by the content of the two counters 302 and 303 are provided, the content of which is increased by 1 each time a new character arrives or when a character is output.

A comparator 304 is provided which contains the addresses AE and AS constantly compares with each other and at its exit can emit two signals, namely an OKE signal, which can enable the input of a new character, and a character OKS, which is the output of a new character previously entered in the memory register 301, can share. The characters are entered one after the other via the input line 305, while the output takes place one after the other

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takes place via the output line 306. There are also a Input sequence control 316 and an output sequence control 317 provided, which are occupied when the Storage register 301 has reached its maximum capacity (OKE = O) or its zero capacity (OKS = O).

Further components of the control device are a logical one Auxiliary circuit with two AND gates 307 and 3O8, which are controlled by a signal E, x ^ elches from the input sequence control originates, as will be explained further below, and an OR gate 309, which together at each instant select an address AB that matches either AE or AS, depending on whether the acquisition of a new Character or the output of a character that has already been saved.

By means of a character counter 3IO becomes at every moment the spatial position of the push button is shown. Moving this printhead by one step increases the value in that Character counter by one unit. ,

When AE = AS, that is, when all the received characters have been output, the content of the character counter 310 is given via an OR gate 311 to an auxiliary counter 312, which remembers the address of the character output last, while the print head is returned to the beginning of the line a signal CRF then causing the printhead to return rapidly in a manner to be explained below. ^v

From now on, the acquisition of new characters and their storage in the memory register 301 starts the output process. In most cases the printhead runs back to the position at which the last character was output. and each advance of the printhead by one step causes the contents of the auxiliary counter 312 to decrease by one

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with this counter as a down counter functions.

A decoding circuit 313 is assigned to the auxiliary counter 312, which indicates the passage of the printhead through the position of the last memorized character, where a Binary signal MCC appears with a zero value at the output. At that moment, the output of the first in the Storage register 301 is released, and the process continues in the manner described above away. . ■ ''

The circuit also includes an output register 31 ¹ J and a gate 315, which only enables access of characters to be output to the output register when the necessary conditions are met, as will be explained further below. The output register 31 ** is fed either from the output of the memory register 301 or by the function of the code, for example the return code of the print head CR and the distance code ESP, which is generated by the control device.

The characters to be printed are accompanied by a sample signal SE which is sent to the input of the input sequence control 3l6 reached. The latter works in four sections and comprises two synchronous flip-flops 316a and 316b.

The time 0 is an idle time in which the storage register 301 awaits the arrival of characters. Immediately when SE and OKE are present, the sequence controller moves until the time the character is in the storage register 301 is written in, and the printer 302 is advanced by one increment. At time 2 there is the input sequence control 316 an acknowledgment signal ACK which causes the signal SE to fall again.

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The output sequence controller 317 forms a link between the buffer and the rest of the control part of the printer. ·

The printer control is of a known type and includes logic circuitry for controlling the clutch and rods that the push button includes. The latter moves from left to right when the signal CI of the output sequence controller 317 energizes the clutch, and is in the Brought to rest as soon as this excitation ceases or as soon as the character counter 310 receives a signal CRF for the accelerated Returns carriage return, as will be explained below. When the push button is the position of the first to be printed When the character of a line is reached, a photocell arrangement enables the control of the rods by means of a logic circuit. The latter includes a sequence control and a counter that runs from 0 to 7 to the seven consecutive ones Reading addresses to be swept over, the counter only storing if characters are sent from the output line 302 to the Output register 31 ^ are transferred. The clock signal for the sequence control of the logic circuit also passes to the input sequence control 316 and the output sequence control 317

The signal CI is maintained by the output sequence controller 317 until the time when the control logic circuit sends out an acknowledgment signal PEC indicating that the character is in the printhead controller has been saved.

The output sequence controller 317 comprises 8 times that in the Pveihenfolge 0, 1, or 2, 3, - 7-, 5 _S 4, 6 are controlled by a combined operation of three synchronously running flip-flops 317a, 317b, and 317c generated.

In order to understand the function of the complete control device, three selected operating cases are discussed below.

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1. Operational case

The moment the printing is finished, the next χ characters of the text must all be stored in the memory register 301 (i.e. OKS = I during the entire Output process, with only the last character being a Puncture corresponds to as determined by a decoder 318 which is sent to the output of the output register 31 ^ switched on).

When the output sequence control 317 passes at time 1, the output register 31 ^ is loaded with the character to be printed. At time 3 when MCC = 0, only the incrementation of the output display device 303 alone is carried out. At time 7, the print control signal C1 is sent to the printer via the output sequence control 317, and the character counter 301 is incremented. This time ends when the signal PEC from the output sequence controller 317 has been received. From time H the sequence control moves to time 0, with no signal CRF reaching the sequence control (which is the case if either the content of the character counter 31O = CC = O or if the presence of OKS CC is different from the Number of characters in the lines.

The sequence control cycle is synchronized with the printer and enables the characters x-1 to be struck.

Since the last character is a function, the 10th cycle of the sequence control at time J causes the character counter 310 to be reset to 0 by the output sequence control 317. As soon as the function has been carried out, the sequence control returns to 0 and waits for the next output enable signal OKS.

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2. Operation case

Assume that ₃ if 'χ characters have been printed, OKS = O, although the line contains χ + y characters, and that only the character χ + y represents a function.

If the printer has 132 characters per line, the Character counter 310 sends a signal · CRP, which is the accelerated one Indicates the return of the pushbutton, either if the counter content is CC = 132 or if in the absence of OKS, CC is different from 0. For the x-1 characters, the functional sequence is identical to that described in the first case Occurrence.

If for the x. If the sequence control runs through time k , the CRF signal is present. The output sequence control 317 is designed so that a transition from time 4 to time 6 is achieved under these conditions.

At time 6 the code CR (carriage return) is entered in the output register 314, and the content CC becomes in the auxiliary counter 312 saved.

The fast reverse of the push button is achieved on the printer during the run following times 7 and 5.

At time 4, the CRF signal is no longer present, since it is now CC = 0, and consequently the output sequence controller 317 moves toward time 0.

After the pushbutton has come to rest again, when new characters are entered in the memory register 301 the value OKS is effective, so that spaces are generated by passing x times at time 3 under the condition MCCTiO. When these χ spaces are generated, the print performed by y characters as in the first case.

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3, operational case

If we now consider the case of tabulation, where the OKS signal is present during the entire operation, which is mostly the case, the memory register contains. 301 the text to be output Ά and the tab code HT from the decoder 318 and then the tab address AD and a text B.

The output of the text A occurs through the continuation of the output sequence control 317 corresponding to cycle 0, 1, 3, 7, 5, 4, D. If the code HT arrives at position 315, the signal CR is transferred to the relevant register and a tabulator flip-flop 319 is switched. That flip-flop thus stores the code HT and allows the output sequence controller 317 to transition from time 0 to time 2. The output sequence controller 317 is arranged to remember the tab address at this time (RAM - £ MCC) and that the output display device 303 advances so that the address AD gets into the memory register and the flip-flop is reset to zero. As soon Once this has happened, the sequence control enables the passage through times 0, 1 and 3.

When passing through time 3, the counter 312 counts down, since the conditions RP ^ function and MCC ^ O apply, so that spaces are taken until MCC becomes 0. This is done by advancing the output sequence control 317 after the cycle 0, 1, 3, 7, 5, ^, 0. If MCC = 0, the output of the text B is carried out from the address AD + 1.

The circuits of the sequence control are not described in detail because they are known per se. For simplification of the drawings are the interconnections of the input sequence controller 316 and the output sequence controller 317 with the other assemblies not shown.

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FIG. 4 shows a possible type of application of the control device according to the invention.

Block 401 comprises a buffer register and the associated ones Circuits that can be designed according to Figure 3, and those for storing the characters to be output.

Block 402 includes the printer and control circuitry for the same.

A keypad 403 is used to generate the various to be output Sign.

From the keypad 403, the messages entered can possibly be sent to a remote computer 404 will.

At the end of a line 407, e.g., a telephone line two signal converters 405 and 406.

The lines shown in dashed lines in FIG. 4 correspond to the function of the exclusive pseudo-increment type. the Continuous lines correspond to a mode of operation, which in addition a repetition on the level of a whole Blocks.

The main operating modes are shown in FIG. 4 and thus show the versatility of the control device according to the invention.

(a) and (b): Local use as a typewriter.

(c) and (d): Use as an output terminal. (a), (b) and (d): Use as a transmitting terminal with local

Copy.
(b), (c) and (d): Use as a teleprinter

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Figure 5 shows the possible uses of the device according to the invention. The same designations are used as in FIG. 4. In addition to the local operating options, which are provided by a connection between the keypad 403 and the memory 401 and to the circuits 402 by the connections (a) and (b) and to the possibilities of a dialog with the computer 404, the use as a display device is also described in FIG. The information intended for the computer 404 is entered into the memory 401 from the keypad 403 and runs via the connection (a), however, can only be given to the computer after pressing a special key the keypad: you can then get on line (e) and back on lines (c) and (d).

When using the control device according to the invention can be practical if the input speed of the characters is below the maximum speed of the printer, which To print a line of characters by making several successive translational movements of the pushbutton, which are separated from each other by a return movement of the print head to the beginning of the same line. For mail mergers and particularly in the case of bar printers, there is a very wide range of uses.

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Claims (2)

Godparents, claims ΐ. Control device for the print head of a serial printer, characterized by a memory associated with the push button, by a buffer register with an input for the successive input of digitally coded characters and with an output from which the
Characters are forwarded to the memory by a display device for continuously displaying the address in
the buffer register of the last in. the input of the same
given character and the first for transmission to the
Output ready sign, through a comparator to
constant comparison of these addresses by a sequence control device to enable the input of a character to the input or the transmission of a character to the output depending on the status of the comparator,
by a memory device for the position of the print head in a line at each point in time in which the
Addresses' match and for controlling the return of the print head to the beginning of the line concerned, and by a circuit for controlling the high speed of the print head up to the crossing of the aforementioned position at the
Entry of further characters after a coincidence of the addresses. 2. Control device according to claim 1, characterized in that the display device comprises two counters which step by step from the characters given to the input or those forwarded for output
Characters are controlled. 309849/1160 Control device according to Claim 1 or 2, characterized in that the memory device a third counter which is incremented by one unit with each drawing step of the print head, and a fourth counter into which the content of the third counter is given when an address match occurs is, the content of the fourth counter is decreased by 1 at each step, and that an enabling device is provided for outputting the first character stored in the buffer register when the content of the fourth counter has become O. Control device according to Claim 2 or 3, characterized by means for determining a tab code, by means for sequential Storing a code and a tab address in the buffer register, and by a Means for increasing the count of the second counter and preventing the output of a character until the Counter exceeds the tab address. 30 9 849/1160