DE1250662B - Arrangement for the selection of the printing elements of an element printer - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

G06k

German class: 42 m6 - 15/10

Number: 1 250 662

File number: J 25856 IX c / 42 m6

Filing date: May 16, 1964

Opened on: September 21, 1967

The invention relates to an arrangement for selecting the printing elements of an element printer the imprint of the character grid column-wise or line-wise through those arranged in a column or line Printing elements takes place and the printing commands for the characters are stored in a read-only memory are.

So-called element printers are often used as fast and also cheap printers, because with these the masses to be accelerated during the printing process can be kept extremely small. In contrast to type printers, the characters are printed by a Selection of printing elements formed from which the character is composed.

In the so-called wire printer, the printing elements consist of individual printing pens that are arranged in the form of a matrix with .Sf columns and Y lines. To initiate the printing process, all of the printing elements required for a character are set and imprinted.

For further simplification, one has already gone over to only one single column or Provide a line with a number of print elements corresponding to the number of lines or columns, thus to use a one-dimensional matrix. With this arrangement it is then necessary adjust or excite the row of printing elements several times during the printing process, according to the number of rows or columns of the matrix. The paper feed and the The pulse repetition frequency at which the row of pressure elements is set must be coordinated with one another. This dissolved, step-by-step excitation of the character matrix requires one in any case Intermediate storage of the print information for the entire character.

It is already known to control the printing process by means of a core matrix or a Make a diode matrix. The core matrix is a true copy of the character matrix and allows the required gradual, temporal excitation of the preferably in one of the columns of the Character matrix corresponding row arranged printing elements. The registered mail of the Printing information for the characters in the core matrix takes place via lines that are in more exact Replica of the character to be printed passed through the corresponding cores of the matrix are. Such a line is provided for all the intended characters. Reading out the Arrangement for selecting the printing elements of an element printer

Applicant:

IBM Germany Internationale Büro-Maschinen Gesellschaft mb H.,
Sindelfingen, Tübinger Allee 49

Named as inventor:
Klaus Tertel, Boeblingen

In the example considered here, the core matrix for printing takes place in columns, in that in each writing cycle all cores of a column are read, starting with the first column of the in Direction of the paper transport lying end of the character matrix corresponding column of the core matrix.

Also the use of a core matrix for control the printing elements has some disadvantages, which can be avoided with the current state of the Technology in the printer field is an urgent need. Taking into account that ζ. B. by the excitation of the printing elements via the magnetostriction effect is the actual printing process only requires an extremely small expenditure of time, it already means a non-negligible one Loss of time if the respective print information is renewed after each readout of the core matrix must be enrolled. The circuit complexity required for this is also not insignificant. Furthermore, as in data processing, the characters to be printed must always be in a binary code are encrypted, the print information is only decoded in an extensive circuit before they can be written into memory.

Another disadvantage of the core memory is that once the form of the characters has been determined or individual whole characters, if at all, then only through difficult craftsmanship Work can be changed or replaced. Since these change requests often exist, remains usually only left to replace the entire matrix with another.

Of course, the other known and suitable for the stated purpose also have Storage types essentially have the disadvantages of core memory. These types of memory are supposed to be here not to be considered further because at

709 648 / 1f5S

the current state of the art of the core memory is likely to be the most suitable.

In the case of the arrangement according to the invention, a known one is intended to be essential for the purpose of the invention cheaper memory can be used. It is a so-called read-only memory or semi-fixed value memory. This type of storage shows some properties that it is just about make its use as a buffer in an element printer appear advantageous. A Read-only memory allows only reading, but not storing or changing of the information content electronically. This is also related to the fact that it is extremely inexpensive can be built. The lack of changeability by electronic means makes the read-only memory also extremely reliable. Among other factors, the saving in time results for the registered mail has a fast access time. In particular, in the arrangement according to the invention a read-only memory can be used, which allows for relatively fast, partial or offers complete changing of the memory content through simple mechanical handling. As an an example just mention the well-known card capacity memory. By simply swapping cards the entire font or just individual characters can be changed as desired.

The aim of the invention is, while at the same time utilizing the advantages that such a read-only memory as a buffer for controlling an element printer with linear, preferably column-wise The arrangement of the pressure elements provides control in terms of the circuitry Effort to significantly improve profitability, operational safety and cycle time.

According to the invention, therefore, an arrangement is proposed in such a way that the print commands for all columns or lines of all characters that occur individually in separate addresses selectable storage locations of the permanent memory are stored, the address of the storage location of the the first column or line of each character is set to be the same as the code specified for each character and in the memory of each column or row except for the last of a character except the Print commands also the following addresses of the memory location of the next column or line of the character is stored.

One of the most significant advantages comes from using the directly for everything to be printed Character specified codes as the address for the storage location of the first column. This will the complex circuit for decoding, which is required in the known methods, is avoided is. Carrying along the subsequent address allows complete freedom in the choice of storage locations for each next columns. One consequence of this is that a memory shared as a buffer memory of the connected data processing system can be optimally used. Also, of course inevitably all the advantages of the read-only memory already mentioned are fully exploited.

Advantageously, the arrangement according to the invention is constructed in such a way that the reading out step by step the memory locations of the read-only memory assigned to a column or row via an address register takes place and the output of the permanent memory with a pressure register controlling the printing elements and a subsequent address register, the output of which is used to transmit the address of the, Storage locations of the respective following column or row in turn with the input of the address register communicates.

Further details of the arrangement according to the invention emerge from the drawing ensuing description of an exemplary embodiment. The drawing shows in F i g. 1 shows an arrangement according to the invention, FIG. 2 is a pulse diagram which illustrates the functional sequence in this arrangement.

The arrangement according to the invention according to FIG. 1 serve to control an element printer whose Pressure elements consist, for example, of magnetostrictively excitable pressure pins. One of those The pressure pin is set into longitudinal vibrations via the magnetostriction effect and is thereby generated a dot on the paper to be printed

'■■ shaped impression. In the example under consideration, all characters to be printed should be composed of the common point grid with five columns and seven lines. A character is printed in columns, ie there is only a single column perpendicular to the paper transport or to the line direction with seven printing pens, that is to say seven possible printing points. The character is accordingly printed after the pressure pens have been excited five times. The relative movement between the row of printing pens and the paper and the time sequence of the excitation of the printing pens is of course coordinated with one another in such a way that the desired typeface is created.

When the characters are printed step-by-step, it is known that intermediate storage of the print commands for the individual print columns is necessary. Since a read-only memory is used in the described arrangement, the required storage capacity depends on the number of different characters and the number of columns per character. If Z is the number of possible characters, X is the number of columns and Y is the number of lines, i.e. printing points per column, then there is the need to be able to print ZX different columns. So ZX different columns must be stored in the read-only memory. Here the possibility is disregarded that with several

Characters in the same columns can occur. In addition, Y bits must be provided for each column according to the number of rows. In the case of forty-eight different characters and a 5 × 7 font matrix, two hundred and forty different columns must therefore be temporarily stored, with each column being composed of 7 bits that represent the print commands. These named sizes are based on the arrangement according to FIG. 1 and 2 are based. To address these two hundred different columns, a combination of 8 bits is therefore required, which offer 256 possibilities. Together with the seven possible print signals, a storage capacity of 240 words with 15 bits each must be provided. The schematic in FIG. 1 shown read-only memory F has this storage capacity.

For a parallel display at the printer output, for example a data processing

plant-R, binary-coded bit combination of a character to be printed eight data lines to inputs of respectively assigned eight or switch to Ol O 8 are connected. If the binary code used to represent the characters comprises less than 8 bits, then, of course, correspondingly fewer OR switches are connected to the printer output of the data processing system. The outputs of the OR switches 0 1 to O 8 each lead to the set inputs of an eight-digit address register AR. The outputs of the four left-hand positions of the address register AR lead via a decryption circuit (not shown in the drawing) to the control inputs of the driver stages Π to T16, which read out the read-only memory ⁷ . The outputs of the right four digits of the address register AR lead, again after appropriate decryption, to the control inputs of the gate stages Gl to G16. The read-only memory F is now connected in such a way that each read driver stage T can be combined with each of the gate stages G. Corresponding to the number of memory locations, there are 16-16 different current paths, so that the 240 memory locations of the read-only memory can be read out via the read drivers T1 to T16 and the gate stages G1 to G16. The circuit for controlling the read driver stages Tl to T 16 or the gate stages Gl to G16 by means of 4 bits each takes place in a simple manner by known logic circuits in such a way that the bit combinations obtained by binary counting from 0000 to 1111 the driver stages Tl to Γ16 and correspondingly assigned to the gate steps Gl to G16. Fifteen read lines are provided corresponding to the 15 bits per memory location of the read-only memory F. The seven read lines for the print commands are connected to the set inputs of a seven-digit print register PR . The other eight read lines lead to the set inputs of an eight-digit so-called follow-up address register FAR. The outputs of the print register PR and the outputs of the next address register FAR are connected to assigned inputs of AND switches A Γ to AT or Al to A8. The outputs of the AND switches A Γ to AT are connected to the control inputs of the associated driver stages PT1 to PT1, through which the magnetostrictive pressure pins are excited. Each of the outputs of the AND switches A1 to AS is connected to a further input of one of the OR switches O1 to O8 . A clock generator T is also provided. The outputs of the clock generator T are designated with b to /, corresponding to the designation of the pulses in the pulse diagram according to FIG. 2. The output b is connected to a trigger input for the driver stages Tl to Γ16 and gate stages Gl to G16. The outputs c and e lead to the second inputs of the AND switches Al to A 8 or A Γ to AT. The outputs d and / are connected to the clear inputs of the address register AR or the subsequent address register FAR and the print register PR.

The sequence of a printing cylinder takes place as follows: The bit combination of the character to be printed is loaded in parallel into the address register AR by the data processing system R via the data lines α and the OR circuits 0 1 to O 8. If this bit combination comprises less than 8 bits, the remaining positions in the address register must be set to "zero". The bit combination of the character simultaneously represents the address of the memory location for the print commands of the first column of the font matrix. The loading of the address register AR is shown in FIG. 2 represented by a single charge pulse a . The clock generator T is triggered at the same time as the address register AR is loaded. The first emitted pulse b gives the command to read out the memory location with the address stored in the address register AR via the appropriately selected combination of a driver stage T with a gate stage G. The 7 bits containing the print information are loaded into the print register, while the same in this memory location The stored subsequent address, i.e. the address for the memory location of the print commands for the second column, is loaded into the subsequent address register FAR. The following c-pulse of the clock generator T supplied to all AND switches A1 ' to AT represents the actual print command. The assigned driver stages PT or the assigned printing pens are printed according to the content of the print register PR. The print image corresponds to the first column of the font matrix of the accepted character. The d pulse now clears the content of the address register AR. The subsequent e-impulse transfers the content of the next address register FAR via the AND switches A 1 to Λ 8 in parallel via the OR switches 01 to O 8 in the address register AR. The address of the memory location for the print commands of the second column is thus now stored in the address register AR. The contents of the next address register FAR and the print register PR are now cleared by the / pulse of the clock generator T. This memory location is then read out by the pulse and the second column is printed in a corresponding manner, after the required mechanical movement of the write head has taken place in the meantime, and the address of the memory location of the third column is loaded into the address register AR. The fourth and fifth columns of the font matrix are printed out in the same order. A new print cycle - the printing of a new print character - is initiated by loading the address register AR with the bit combination of the new character. .

Since no subsequent address is stored in the memory for the last column of a character must be, through these eight free memory locations, any necessary run-out routines can be used addressed.

Claims (2)

Patent claims: 1. Arrangement for the selection of the printing elements of an element printer, in which the imprint of the Character grid column by column or line by the printing elements arranged in a column or line takes place and the print commands for the characters are stored in a read-only memory are, characterized in that the print commands for all columns or rows of all characters occurring individually in separate memory locations that can be selected using addresses of the read-only memory are stored, the address of the memory location in the first column or line of each character is determined to be the same as the code specified for each character and in the Space for each column or row except for the last of a character except the following address of the memory location of the next column or line with the print commands of the character is stored. 2. Arrangement according to claim 1, characterized in that the step-by-step reading of the memory locations of the read-only memory (F) assigned to a column or row takes place via an address register (AR) and the output of the read-only memory (F) is connected to a print register (PR) that controls the print elements (PT) and a subsequent address register (FAR) , the output of which is in turn connected to the input of the address register for transferring the address of the memory locations of the respective subsequent column or line stands. Considered publications:
German Auslegeschrift No. 1127 644;
British Patent No. 784 450. 1 sheet of drawings