DE2135657A1 - Serial printer with a fixed insert - Google Patents

Description

Serial printer has a fixed insert

The invention relates to high-performance impact printers and used in data processing systems
particularly applies to "on-the-fly" mail merge printers. In particular, the invention relates to a
on-the-fly printer for serial printing along a print line on a medium that maintains the pressure, consisting of a main frame, a type carrier that is in constant motion, in order to get to the direction
of the printing line in a substantially parallel direction of movement successively to bring each character of a character set to at least one printing point, at least one carriage movable along the printing line in order to successively move all possible
To occupy one place along the print line
the pressure element attached to the chute, an insert

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to interact with the printing element and the type carrier, to effect printing on the receiving medium.

Many different designs have been adopted for these printers, so onward A distinction can be made between printing and reverse printing synchronous or asynchronous serial printers3.

In any case, such a printer-Provide a held in constant motion type carrier to sequentially all characters to bring a font with each predetermined print position to cover, a pressure member or a print hammer, the right to oen points in time ie, is then operated to when the printing characters is in the correct printing position, and a carriage to move the print hammer and in most cases also the type carrier along the print cell.

It is known that the required characteristics for such printers are high printing speed and fine Print quality and that these characteristics are in a sense incompatible with one another.

It is also known that in order to achieve better printer performance it is useful to use the characters to be arranged alternately as closely as possible next to one another on the type carrier, so that for a given, through the type carrier needed time to create all characters

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to bring in front of a given pressure point the effective Speed of each character in its passage can be as low as possible through this point.

However, the accumulation of characters is mutually as close together as their dimensions allow, usually for other reasons, such as the width of the pressure gauge, which in some printers is supposed to extend essentially over two adjacent printing points, but not two characters may print at once, the risk of mechanical leech influence, the reset time of the pressure gauge and others, not possible.

Some attempts have been made to remedy this deficiency by inserting an intermediate link in the return process , but the mechanical devices used for this purpose have poor reliability, being limited to special constructions and not completely solving the problem.

Some of these structural designs contain the Movable intermediate parts attached to the sled and associated: i means to transmit the movement to them, however, they increase the sled's inertia and are subject to wear and tear.

For some printers, the movement of the pruck slide not evenly but gradually, so that it is subject to strong accelerations and slowdowns. In this case the use of a

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Intermediate part with the means assigned to it for transmitting the movement, which is attached to the slide is a negative factor that is detrimental to the requirement of reduced sled inertia.

The object on which the invention is based is therefore to increase the packing density of the type carrier worn characters without increasing indolence the carriage, which improves print quality and printer performance,

According to the invention, this object is achieved essentially by using a fixed intermediate part, which is inserted between the print hammer and the type carrier, which is hereinafter referred to as "insert"("interposer") and which is rigidly attached to the main frame of the printer, extending along the entire print line and communicating with two partially overlapping print hammers cooperating "with places other ¥ according to the invention is" vorgesehlagen that the insert is fixed to the main frame and, namely an _S consisting of a plurality of feed elements for each pressure point and the pressure member of at least two Druckhämraern whose Print heads at least partially overlap.

Further details and advantages of the invention are shown below with reference to one in the drawing preferred exemplary embodiment described in more detail. Show it;

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1 is a perspective view of a printer according to FIG the invention in a schematic representation,

Fig. 2 is both a plan view of the mechanical arrangement and the logic circuit for A schematic diagram illustrating the control of the operation according to the invention,

3 shows a section through a partial front view of a structural detail of the printer according to FIG. 2;

i'ig. ha, h1) and 4c a schematic plan view, a front view and a side view of a structural detail forming a variant of the invention.

Fig. 1 illustrates in its essential elements an on-the-fly asynchronous serial printer of the backward hitting design. In order to enable a better overall representation of the device, the Drawing shown partially in section.

The printer has a main frame with a base plate and two side cheeks 2 and 3. Between the side cheeks there are cylindrical guide rods 4, 5 »6> 7, u, 9 on which suitable moving parts can be moved. A first printing carriage 10, on which a bevel gear pair 11 is attached, is displaceable on the guide rods h and 5. On the shaft 12 of one of the bevel gears, a type carrier 13 is attached, which has the shape of an Itade, which bears a set of characters or other characters on its outer circumference in a raised form. Of the

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Type carrier 13 is kept in constant rotary motion at a constant speed via the bevel gear pair 11 with the aid of a square shaft 30 driven by drive means (not shown). A second printing carriage I ¹ I _1, on which two printing hammers 15 and 16 are attached with electromagnets 17 and 18 assigned to them, is displaceable on guide rods 6 and 7.

The two hammers are so hinged in a matching s.'eise, that your printhead by energizing the electromagnets in The direction on the type carrier aligned with the hammers can be adjusted.

On the oeitenwange. °. attached mating ilonsoleii hold two drive pulleys 19 and 20 attached to the shaft 21 driven by a motor 22, the motor being an indexing motor or any one of them . otor that is suitable for imparting a solitary movement to the slide.

Two concealed by the side wall 3 and therefore cind "attached to the side wall 3 in i / ig.l not shown Leerlaufrilleiiseheiften, two lift cords 23 and 2h grooved see between the Aiitriebsrillenscheiben and their associated idle Iben tensioned and in the Driiclcschlitten 10 and lh hooked. As a result of the action of the motor 22, both carriages move in synchronism and with constant mutual alignment along the drive line.

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Urfindungi> sufficient ;; - is an insert from a rigid, to formed the flange of the printer's attached crosspiece 25, that carries a set of flexible blades, their free ones Tip κι it the print line is at the same level, and read is inserted between the two carriages.

Each blade 2b coincides with a printing point at which a character can be printed. The distance between Your liittelliuien is therefore like a step backwards.

In one aspect of the invention, every tip is of the blades on their back, i.e. on the side facing the print hammers, provided with an elevation.

These surveys are in two different orders in two different ways Arranged heights, each order cooperating with a print hammer as required. With others Words correspond to the blades with an elevation of the first order of the odd-numbered pressure points and the blades with the elevation of the second order the even-numbered pressure points.

The first print hammer can only print at the odd print point and the second hammer can only print at the cause even-numbered pressure point.

The width of the hammer in the direction of the print line is in Appropriately larger than one pressure step and not more than two pressure steps.

The reason for this is explained in more detail below.

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The not shown, the pressure-retaining medium is in the printer between the type carrier 13 and is inserted into the insert 25 along with the ribbon 27 and leans substantially against the blades 26 and against a suitably shaped paper discharge plate 28.

At its upper part, the pressure-maintaining medium is captured by two pulling devices, each consist of a link chain and a pressure pad.

The two pulling devices can be moved on the guides 8 and 9 to their mutual distances and adjust the distances from the side walls to the width and position of the medium receiving the pressure, usually provided with side perforations is.

Only one of these devices is shown in FIG. 1, namely the left-hand one as seen from the front of the printer and denoted by 29.

Both pulling devices are driven with the aid of a suitable drive device, not shown.

The printer is driven by a drive device, not shown, for driving the ink ribbon, by a Time control device with a time control wheel that is firmly connected to the type carrier and through one attached to the same slide in a fixed position and interacting with the timing wheel Scanning device added.

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These devices are well known and are therefore not illustrated in FIG. The timing wheel can for example from a disk made of ferromagnetic material Material exist, which is provided on its outer circumference with teeth or notches, each one Characters of the type carrier are assigned.

The scanning device can have a magnetic flux path an air gap bridged by the timing wheel exist. The teeth or teeth present on the timing wheel Notches change the width of the air gap, whereby a winding coupled with the magnetic flux each time if there is a notch or a tooth opposite the scanning device, a signal is emitted or feeds.

The mode of operation of the printer described will now be explained in more detail using the logical-mechanical diagram according to FIG. 2 and the detailed Drawing described according to Figure 3. f

Fig.2 shows schematically the essential mechanical Parts of the printer and the electronic circuit assigned to it for its logical control.

It contains a plan view of the type carrier 13, the timing wheel 40, which is firmly related to it, and the scanning device hl. These parts are attached to the first printing carriage 10.

The carriage 10 slides in the vicinity of the ribbon 32 and of the pressure-maintaining medium 33 along the pressure

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row. On the opposite side is a second print carriage 14 on which two print hammers are appropriate. There are only the print heads of the hammer through the rectangles 42 and 43 (Fig. 2 and 3) indicated schematically.

W The insert is arranged between the printheads of the hammers and the medium that receives the pressure. It consists of a multitude of blades arranged along the line of printing and carried by a rigid, flexible blade as already shown in Pig. 1.

The flexible blades that match the printed line have a width that is equal to or slightly larger than the maximum width of the characters to be printed, and are arranged at a mutual distance from a printing step along the printing line.

In relation to the print medium, the blades have elevations on their rear side, which are alternately at two heights are arranged.

In Fig.2 are the bumps of the blades and the heads the hammers shown in section in the plane BB according to Figure 3

It should be noted that in Fig. 2, the hammer head 43 is shown in plan view in section and that in a smaller Hammer head 42 located at the height of the hammer head 43 is covered.

Correspondingly, the elevations 44, 46, 48, 50 are shown in section and the elevations 45, 47, 49 in plan view.

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Fig.3 is a section through the blades and hammers on the plane AA according to Figure 2 in front view and clearly shows the arrangement of the elevations in two sequences. Figures 2 and 3 also show that the width of the hammer heads is substantially equal to that Width of two pressure points.

The hammer head acts in accordance with the position assumed by the carriage 14 along the pressure cell at once on only one of the elevations 44, 46, 4ö, 50 .. ». and the hammer head 42 on only one of the elevations 45, 47, 49 ... a.

FIG. 2 also shows a block diagram in schematic form the circuit controlling the operation of the printer, which is limited to what is necessary for clarity of the invention is needed.

The operation of the printer is controlled by a with the |

Reference numeral 60 and generally referred to as a logical control unit is controlled. These Unit generates command signals for performing various operations such as printing, feeding of the printing carriage from one printing position to the next, the carriage return, the line feed, the gap detection etc. in the prescribed order and at the required times.

'In detail, the binary code combinations of the various to be printed

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Characters consecutively of a comparison circuit 62 supplied.

The comparison circuit 62 successively takes the binary code combinations over the set of lines 63 the different characters of the type carrier that are in the correct printing position on.

These code combinations are built up by a counter circuit 6k which records the sequence of the time-controlling character pulses emitted by the scanning device kl.

If the comparison between the pulses is positive, i.e. if the two code combinations are together match, the comparison circuit emits a Pressure command signal which is fed via line 65 to a controllable delay circuit 66.

The amount of delay depends on the amount of time that elapses between the receipt of an logic control unit 60 via the lines 68 and 69 supplied clock signal and the receipt of the the print command signal generated by the comparison circuit and received on the line elapses.

The signal supplied by the logic control unit via the line conducts the through the circuit 71 continued carriage forward operation and selects via line 72 with the aid of the hammer selection circuit one of the two print hammers,

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The print command signal appropriately delayed by circuit 66 is provided over lines 7 ^ and 75 applied to a first input line of two AND gates 76 and 77.

One by the hammer selection circuit 73 for the even-numbered and uneven-numbered printing points alternately generated release signal is transmitted via lines 78 and ' 79 to each of the second inputs of the AND gate circuits 76 and 77 created.

This will make the print command signal at the correct timing via one of the lines BO and 81 to a predetermined one Hammer applied.

In the now to be discussed operation of the short

described printer, it is assumed that the two

Printing carriage is in its shown in Fig. 2 Position and stand still.

This can, for example, be the initial state for printing a line of characters.

The type carrier rotates around axis 0 at a constant speed in the direction indicated by the arrow, which is also done by the time control disk hO.

When the various characters, for example the one designated by 82, are coincident with the printing point, the scanning device 41 sends out pulses which allow the counter 6k to continue counting. The impulses

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are emitted leading to the finite Take into account when the hammers are actuated.

The counter Gk therefore shows on its output lines a binary code combination which embodies the character which at any point in time is in agreement with the printing point to be equated with the survey k6.

If at a given point in time the logic control unit 60 applies a code combination representing a given character to be printed to the comparison circuit 62, a waiting or latency period is initiated which can change from a zero value to a maximum value equal to the period of rotation of the type _T carrier.

At the end of this latency period, the character to be printed is in the printing position (and at the same time at the printing point), the counter 6h showing a code combination on its output lines that corresponds to one of the characters to be printed. Therefore, the comparison circuit emits a print command signal. Since no carriage feed process has been initiated beforehand, the print carriages stand still and the print command signal is transmitted to the selected print hammers without delay, so that the print head k3 is pushed in the direction of the type carrier and the blade is set in motion with the aid of the associated elevation . The pressure-retaining medium and the ribbon are thus pressed together for a short period of time between the blade and the type carrier,

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wherein the medium receiving the pressure is the impression of the Sohrift mark.

It should be noted that even if the width of the Ilainmer head equal to the length of two pressure points is to print only one character at a time can, since the hammer head 43 only hits the elevation 46

and does not act on the elevation 47. Therefore I

regardless of the spacing between the characters on the Type carrier no risk of double pressure, as the hammer only acts on a single blade at a time and the width of each blade is equal to the maximum width of the characters to be printed is.

In this way, the characters can be attached to the type carrier be arranged closely packed together so that each is contained in a frame the width of which is the same is the maximum width of the character to be printed, with the! lames adjoining each other.

It should also be noted in relation to FIG. 2 that the pivot point of the type carrier at the time in question does not match the center line of the one corresponding to the elevation 46 Pressure point covers, but is on the center line between the elevations 46 and 47 corresponding Pressure points. The character in print is therefore on the print plane somewhat inclined, but this inclination is negligible and does not affect the print quality. For a type carrier with 64 on its outer circumference

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evenly distributed characters it is about 3 ° · In addition, it is through a matching concave design of the print heads and a corresponding convex formation of the elevation and by utilizing the torsional elasticity of the blades possible to twist the blades slightly so that the pressure is even when printing is distributed.

The print command signal also becomes the logical one Control unit 60 supplied, which in effect of it delivers a carriage feed command to the To move the carriage to the next printing point according to a predetermined law of motion.

According to the invention and using the double hammers as well as the insert assembly can when performing the printing of a character on the elevation corresponding next printing point the printing takes place during the movement of the carriage without waiting, until the carriages have completed the path of a printing step.

It is now assumed that the printing of a character at position 46; (from now on the respective Pressure point with the reference number assigned to the elevations of the corresponding blades of the insert designated) has just taken place and that the carriages start to move (when looking at Fig.2) after move right. The logic control unit 60 applies

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the comparison circuit 62 the code combination of the new characters to be printed. Suppose that the counter 64 outputs the same code at approximately the same time. This means that, as soon as the carriage initiates its adjustment, the characters to be printed at point 47 through the sensing device is felt to be present at the printing point. .

Since printing must take place at point 47, the print command signal coming from the comparison circuit 62 becomes suitably delayed so that it gives the type carrier the time necessary to in order to bring the character with the printing point 47 to coincide.

The structure of the delay circuit is for the embodiment of the invention are not important, and numerous are the technical solutions that are chosen can be. Some of them are, for example, in their details in Italian patent 885 described. The appropriately delayed print command signal brings about printing by means of the Hammer head 42 in motion.

The right hammer is preloaded, because the signal to start the feed of the slide is also the Hammer selection circuit, which in its simpler form can be a flip-flop circuit can.

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The fact that the hammer 42 has a width equal to the width of two pressure marks makes this possible Print at point 47 be there when the adjustment of the slide has not yet taken place. On the other hand, the insert only allows printing one character at a time and that itself when the characters are arranged close to one another and when the print head is one width equal to the width of two pressure points.

The alternating use of two print hammers also makes it possible to print two characters closer together Print the sequence without waiting for the first hammer to return to its original position.

The above description is based on the assumption that the second printing takes place immediately after the first, it being understood, however, that this depends from the point in time at which the character to be printed is detected by the comparison circuit 62, the printing at any time during the course of the Movement of the carriage can take place by making a correlation delay which is the fraction of the pressure step already taken is taken into account and without delay when the movement is carried out.

It is also clear that a third printing process at the point 48 can only take place if the movement of the carriage is carried out from point 46 to point 47.

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The example described is based on an asynchronous serial printer with Rückwärtsdruckeη been carried out.

It is clear, however, that the invention can also be applied to synchronous printers as well as to forward-printing printers, i.e. can be used in all cases in which a movable type carrier carries the various characters by a local movement essentially in the direction brings the pressure cell to coincide with at least two adjacent pressure points and the pressure elements are attached to a print carriage movable along the print line.

When printing forward it is also clear that the individual Elements in a different order from the one described Order, i.e.: print hammer, insert, Type carrier, ribbon, medium retaining the pressure, roller.

The use of an insert rigidly attached to the frame of the printer as described solves this problem Problem of the transmission of motion and allows the design of moving parts with significantly reduced Inertia.

There are numerous changes that can be made without departing from the scope of the invention. In detail, it is useful to describe an arrangement in which each blade of the insert can interact with both hammers, depending on the need not according to the even or odd pressure point, but according to the position of the hammer

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within one printing step, i.e. according to whether the carriage moves through the first half or the second half of a printing step moved, controlled. Figures 4a, 4b and Ac illustrate this as Example arrangement applied to a forward printing printer.

In the drawing, only the parts required to clarify the invention are shown.

Fig. 4a is a plan view showing a portion of the roller 90, part of the pressure-retaining medium 91, part of the ribbon 92, one of three radial tongues, 93, 94, 95 existing Teilces type carrier, one from the surveys 96, 971 98 at the tips of as many blades existing part of the insert and two print hammers 99 and 100 shows.

Figures 4b and 4c are a front view and a side view, respectively the same devices and illustrate with better clarity their mutual position,

The type carrier is formed from a daisy-like wreath of flexible tongues.11, which carry the characters in a raised form at their free end.

The daisy is attached to a shaft 105 which is kept in rotating motion by suitable drive means will.

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The surveys of the stakes, one for each Pressure points that are aligned with one another in a single sequence become the blades 93 »9 ^, 95 formed for example from hardened steel by turning its tip by 90 °.

The insert is attached to the frame of the printer

and extends over the entire length of the printing i

row. The type carrier and the hammers 99 and 100 are attached to the printing carriage and are after a predetermined law moves together along the print line.

From the drawing it can be seen that the hammers 99 and 100 in the vertical direction in two different Heights are arranged so that they partially overlap.

The hammers have a width that is slightly larger

than half a printing step, and are horizontal \

arranged offset to each other so that together they cover an entire printing step or a width, which is a little bigger.

In this example, the printer works as follows:

It is assumed that FIG. Ka shows a rest position of the carriage and that a predetermined character is to be printed at the printing point embodied by the blade 93.

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If the character to be printed is affected by the movement of the type carrier with this print point is brought into congruence, the printing is carried out by jolting the hammer 99 forward.

Immediately afterwards, the carriage can move forward to the next position.

However, it needs the next one to effect the push Pressure point not to be waited for the execution of the movement. It should be noted that the shifts to hammer 99 arranged hammer 100 during the entire adjustment half-period of the carriage in a suitable position for Printing is during the course of the second half period the hammer 99 in the appropriate position for printing is.

Therefore, according to the point in time at which in the course the movement of the carriage, the printing must be carried out, the hammer 99 or the hammer 100 advanced as required.

The design of the circuitry for effecting this selection presents no difficulty and can be adapted to the various specific characteristics of the printer such as the fact that it is an asynchronous or a synchronous printer.

Another structural detail of the insert is shown in FIG. 4c: the crosspiece carrying the insert

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101 is provided with an extension 102 which has a groove has, in which an elastic cushion 10 * t is arranged is what the vibrations of the pliable blades of the insert when they return to rest should dampen.

It is clear that further structural arrangements can be considered, for example, at which the surveys of the operation on rigidly

steered parts provided with return springs are attached or slidable on suitable guides, etc., without thereby departing from the scope of the invention.

Claims ;

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Claims (4)

Claims On-the-fly printer for mail merge along a print line on a pressure-maintaining medium, consisting of a main frame, one in permanent Moving type carrier in order to move in the direction of movement substantially parallel to the direction of the pressure cell successively each character one Font to at least one printing point to bring at least one carriage movable along the print line to successively all possible To occupy positions along the print line, a print element attached to the carriage, an insert to cooperate with the printing element and the type carrier to print on the receiving print To effect medium, characterized in that the insert (23) is attached to the main frame (1, 2, 3) and out a plurality of insert elements (26), one for each pressure point and the pressure element of at least two print hammers (15 »16), their print heads (42, 43) at least partially overlap. 2. Printer according to claim 1, consisting of a movable along the print cell first carriage to successively to occupy all possible positions along the print line where the type carrier is attached, and one in correspondence with that of the first carriage -25- 109884/1781 at any time occupied positions along the pressure cell movable second carriage on which the printing element is attached, the first and second carriages with respect to the printing receiving medium are located on opposite sides, characterized in that the Insert (25) between the pressure element (l5> ί-6 or f 42, 43) and the pressure-maintaining medium (33) is inserted. 3. Printer according to claim 1 or 2, characterized in that the print heads (42, 43) of the hammer (15, l6) themselves completely overlap at a first and a second height and have a width substantially equal to the length of two pressure points (46, 47> Fig.2), the Elements (26; Fig. 1) of the insert (25) in accordance with the first and second height with Surveys (44, 4ό, 48, 50 .... or 45, 47, 49 ...) are provided to each with a single one of the hammers g (15, 16 or 42, 43) to work together. 4. On-the-fly printer according to claim 1 or 2, characterized in that the printing hammers (99 _f 100; Fig. 4b) partially overlap at a first and a second height and each have a width substantially equal to half the length of a printing point. 1 - 22 686 109884/1781 Empty soap