DE2321152A1 - COMPENSATION DEVICE FOR A PRINTER - Google Patents

Description

Compensating device for a printer

The invention relates to a compensating device for changing strengths of a movable one Print head having printer to print documents.

In order to be able to print a document with most of the printers available to date, the document must be in contact be brought with a pressure element. The required relative movement between the document and the printing element, in order to bring these into contact with one another, either the pressure element, one holding the document, can be moved Plate or both are effected. Ordinary is

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the movement or the stroke of the moving element is substantially greater than the thickness of the document to be printed, so that changes in the thickness of the document are not a factor limiting the printing quality of the printer. However, if the thickness of the document is so great that it is included as a factor, a certain flexibility must be provided, for example in the case of the plate holding the document, in order to ensure an essentially uniform position of the printing plane. However, the time required to print a single character is determined to some extent by the length of the printing stroke. In the case of high-speed printers, an attempt has therefore been made to make the length of the stroke as small as possible. For example, some printers use a matrix of wires as a printing element, which are only moved about 0.12 to 1.14 mm when printing a character. On average, these wires will be between 0.38 mm and about 3 ^ ma. emotional.

High speed printers of this type have heretofore been e.g. for printing out information from a data processing system used. In these applications, the document to be printed has only one thickness and therefore it can fairly good control over document quality and strength can be maintained. On the other hand, they become such Printing elements used in connection with printers that are used to print bank documents arise as a result The small hub has certain "problems. In these applications, the printer must operate with several different types of of documents such as bank IDs, check books, e-payment books and the like, work. In addition to these various types and qualities of documents the thickness changes with the respective side of the document that is to be printed, since the document is before Printing process subjected to a certain pretreatment The quality and thickness of the document can vary

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continue to change. The small stroke of the printing element, however, requires that the document with the printing plane in more precise Orientation is independent of the thickness or quality of the document.

The object of the invention is to create a compensation device with which the different strengths or Thickness of a 'document to be printed in a printer can be compensated.

In a compensation device of the type mentioned, this object is achieved according to the invention by a document receiving shaft, one side of which is given by a pair of elongated Fühlmeßstangen that to form a Opening through which the print head, which acts on the document in the shaft, can pass, at a distance from one another are arranged and the print level for the print head precisely defined by an elongated plate, which is arranged on the side of the shaft opposite the printhead is and is in the rest position at least for the most part outside of the shaft, the width of the Plate larger than said opening and the shaft next to the plate for moving the plate into the shaft is open is, by a working before the operation of the print head first device for bringing the plate into contact with the document in order to carry out a printing process and firmly pressing the surface of the document against the guide rods, making that surface precisely in the Printing plane is arranged, and by a plate so elastically holding the second device that the plate at a certain pressure is retractable, causing the surface of the document in the printing plane and against the plate

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Pühlmeßstangen with essentially uniform pressure independently keeps pressed by the thickness of the document.

Further refinements of the invention are specified in the subclaims.

The invention is explained in more detail using an exemplary embodiment shown in the drawing. Show in detail:

Pig. 1 is a partially cut-out side view of a printer to be used in banking, which has a ' Compensating device according to the invention for the document thickness has, the mechanics being shown in the idle state,

Pig. 2 is an enlarged, partially cut-away side view part of the in Pig. 1 is also in the idle state,

Pig. 3 is a top plan view of part of the in Pig. 2 shown Printer,

Pig. 4- a block diagram of the electrical control circuit,

. those related to the one in the Pig. 1 to 3 is used, and _f

Pig. 5 is a flow chart of the operation of the invention Printer »

As can be seen from the figures, the printer has a Well or slot 10, which is able to receive a document 12 to be printed. In the context of the following description

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it is assumed that the document 12 is a bank passbook and the printer can be part of a bank data output device like. The shaft 10 is delimited on one side by sensing rods 14 and 16 which have an opening 18 between them form through which the print head 20 penetrates. The pressure surface or plane is along the side of the shaft 10 through the beams 14 and 16 are defined in the area of the opening 18. An ink ribbon 21 is at least partially in the opening 18 arranged between the print head 20 and the printing plane. The distance between the printhead 20 and the printing plane. is slightly smaller than the pressure stroke of the wires of the printhead 20 (e.g. about 0.5 mm), the ribbon 21 being about 0.2 mm of this gap occupies. As can be seen from FIG. 3 is, the opening 18 extends from the left side to the right side of the shaft 10.

Although the type of printhead 20 does not form part of the present Invention, it is assumed for the purpose of illustration that a print head provided with a wire matrix is used which is now available for purchase from various manufacturers. A wire matrix printhead this type is described, for example, in U.S. Patent 3,592,311. The printhead 20 is mounted on a carriage 22 which passes through a suitable drive in the direction of and away from the paper can be moved, as shown in FIG. 1, or from left to right in FIG Manner so that the printhead 20 can be used to record a line of characters on the document 12 can. The mechanics for moving the carriage 22 and for controlling the printing of the characters by the print head 20 may be of conventional design and does not form part of the present invention. A description of the

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this element is therefore not provided here. .

A document entered into the chute 10 comes to a standstill at an accountant 24 which causes it to move vertically is mounted on a shaft 25. The bookkeeper 24 is connected to a conveyor belt with the aid of a clamping device 26 28 connected, which has guide rollers 30 and a Driving roller 32 is performed. The! Friction roller 32 is of a Motor 3 ^ rotatable in both directions of rotation. The control of the motor 34- will be briefly described.

The accountant 24- has one who takes up the document Slot 36, in which the lower edge of the document with Clamped with the aid of a plunger 38 of a holding magnet 4-0 can be. As will be explained later, the "holding magnet 40 is activated as a function of the detection of a document" in the shaft 10 actuated by a photo detector 4-2.

The - compensation device according to the invention for the document thickness has a motor 44 which is connected to a gear 48 via a shaft 46. The gear 48 engages into a smaller gear 50 which is mounted on a shaft 52 is. Also on shaft 52 is a cam 53 with slots 55 and 57 and a pair of cam surfaces 54, which are positioned at rest with their low cam zones with associated cam follower rollers 56 are in contact (compare FIGS. 1 and 3). A switch 59 is arranged so that it is closed when a part of the cam plate 53 except for the Slots 55 and 57 is located next to it. Each cam follower roller 56 is connected to an associated one by a pin 58 Plunger mechanism 60 connected. As best from Fig. 2

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can be seen, each plunger 60 is guided in a cylinder 61, with a compression spring 62 between the plunger and the opposite inner end of the cylinder is included. Each ram is for its movement in the associated cylinder 61 connected to a pin 65 which is in a slot 6? is guided in the cylinder. A rifle 69 with a splash 64 is on the outside of each cylinder 61 on their next to the roller 56 lying end screwed. Every cylinder 61 is carried by a sleeve 71 which in turn is fastened in a clamp 68. The brackets 68 are with Screws 70 attached to the printer housing. A compression spring 66 is enclosed between the end flange 64 and the bracket 68. An elongated plate 74 extending over the Width of the shaft 10 extends, is attached to a projection 72 of the cylinder 61 via screws or pins 76.

If the individual components are in the position shown in FIG. 1, the plate ψν is outside of the shaft 10, so that a document 12 can easily be inserted into the shaft and moved in it. If the cam disk is rotated into a position that becomes effective for the high cam zone, as shown in FIG. 2 is shown, the plate is moved forward into the shaft, the rods so that the document firmly presses against the JTühlmeß 14 and 16 and this brings it into agreement with the printing plane. The leather 62 is compressed to an extent that changes with the thickness of the document, so that this serves to compensate for the thickness of the document. In this way, both the position and the pressure on the document remain essentially the same regardless of the respective document thickness.

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As can be seen from FIG. 5, in the first functional step 80 a bank passbook or other document 12 is stored in the Slot 10 inserted. Just before the document reaches the holding slot 36, the photo detector 42 detects the bank passbook in the well and generates an output signal on line 82 (Fig. 4-) which is fed to an input of an AND gate 84 is given. The signal on the line 82 is also given to a pulse generator 86. The output signal of the pulse generator 86 is given to a flip-flop 88 in order to set it to its 1-switching state. Of the 1 output 90 of flip-flop 88 is with the other input of AND gate 84 connected. The output line 92 of the AND gate 84 is. to excite the electromagnet 40 connected to this, whereby the plunger 38 into the slot 36 is driven in to compress and hold the document located therein (step 94 of FIG. 5) As long as there is a document in the shaft 10 and the flip-flop 88 remains set, the electromagnet also remains 40 switched on to allow movement of the document to be controlled and to prevent removal of the document.

During the next step 96, the document is either Aligned manually or automatically in order to move the line to be printed in a position opposite the opening 18 and to bring the print head 20. During manual operation, the motor 34 is separated from the friction roller 32 so that the Operator can move the document 12 and the accountant 24 until the document is in the desired position. In automatic operation, the next line to be printed is either automatically detected or keyed in by the operator and then

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the motor 34 operates in such a way that the accountant 24 as long as it is lowered until the document is in the appropriate Position is, which, however, also does not form part of the invention.

Until an indication is received during operation 98 that the printing process should begin, happens for the time being nothing. This pressure indication can either be by pressing a pushbutton on the output device on which the printer is used as Output device of a computer can be used, or can be received by a data processing device, when it has finished processing a transaction and is ready to place the transaction in a bank passbook or another document 12 to be recorded. The pressure signal is transmitted via a line 100 (FIG. 4) and an OR gate 102 applied to drive a multivibrator 104. The multivibrator 104 generates a pulse through an OR gate 105 is given to the motor 44 in order to start it, wherein its shaft 46 rotates counterclockwise. The cam plate 53 rotates with the shaft 46 and thus moves the Actuating plunger of switch 59 out of notch 55, whereby the switch is closed. The switch 59 remains closed, so that a signal through the OR gate can continue to be given in order to keep the motor 44 switched on until the incision 57 has been rotated through 240 ° next to the switch. Depending on the pressure signal on the line 100, the motor 44 rotates the gear 48 counterclockwise like this one in the Pig. 1 and 2, thereby rotating the gear 50 and the cams 54 by two thirds of a turn in the direction of the Clockwise. When the cam disks 54 rotate, the cam follower 56 reaches the high cam zone, whereby the Plunger 60, cylinder 61 and plate 74 during operation

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at step 106 are all moved forward. As the ^platen 74 advances into engagement with the document 12, the spring 62 is compressed by an amount which varies with the thickness of the document. The spring 62 is strong enough, however, to compress the document regardless of its strength and to press it firmly against the sensing rods 14 and 16 under essentially the same pressure and thus against the pressure plane formed by the opening 18. The spring 62 is preferably critically dampened in order to ensure a firm, vibration-free and bounce-free holding plate for the document during the subsequent printing process.

If the document is suitably pressed against the plate? 4, the carriage 22 begins its movement during operation 108 and during operation 110 also the printing process. As previously described, the mechanisms and controls for these modes of operation do not form part of the invention and are therefore not described further.

After completion of the printing process, a carriage return signal is generated during step 112> either as a function of the operator pressing a carriage return key manually or, in the case of an output device, from a data processing device. The carriage return signal is given again to the multivibrator 104 via a line 114 (FIG. 4) and an OR gate 102. This causes the motor 44 to start up again and the cam disks 53 and 54- rotate clockwise by a third of a turn (120 °) until the incision 55 is located next to the switch 59 again. This allows that

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Cam followers 56 in their position shown in Fig. 1 on the to get back to the low cam zone. The plunger 60 and the elements connected to them get into their in Fig. 1 EuheStellungen shown by the action of the cam follower springs 66 back to the pool 64-. Step 116 is ended in this way.

From Fig. 5 it can be seen that the next step is during of the operation, step 118, determines whether the information continues on a subsequent line. The information goes on a subsequent line, the program advances to step 120 while dsm makes a determination whether the last line of the document is already printed or not. It is believed that the last Line of the document is not yet printed, the program proceeds to step 122, during which the Position of the bookkeeper 24 and thus the document is shifted by one line in order to print the next line to enable. This is achieved by sending a signal to the drive 3 ^ via a feed line 124 (FIG. 4) is given to the accountant. The "feed pulse on the Line 124 can be accessed by the operator or the data processing device pressing a feed button or, as shown in FIG. 4, by delaying the carriage return signal on the. Line 114 in the delay circuit 126 can be obtained by a sufficient time for operation 116 to be completed and then this signal is given to the feed input of the motor. This way of working is feasible because the Carrying out a feed has no effect, even if step 118 or 120 should indicate that the feed step 122 is not required.

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From operation 122, the program returns to step 98 back so that a pressure signal appears on line 100. As previously described, this causes the cam disks 54 to rotate by 2/3 revolutions to bring the plate 74 again into a position pressing the document 12 against the printing plane. Printing a The new line is then carried out in the manner previously described.

If it is determined during operation 118 that the information is stuck, or during the step determines that the last line of a page of the document has been reached, the program proceeds to step 128. It should be pointed out that in the case of an output device it may be necessary to display the information to be printed out during of operation 130 to be held when the last Line of the page has been reached. During step 128 a long feed pulse is generated, either manually or from the data processing device, on line 124 or a return line 132 to the motor 34 to the accountant 24 in his in Pig. 1 rest position shown traced back. A signal is then given over the line 134 either manually or by the data processing device to the O input of the flip-flop 88 in order to to reset it to its O-state. Not longer there there is a signal on the line 90, the AND gate 84 blocked and the holding magnet 40 switched off. The plunger 38 therefore returns to the position shown in FIG Fig. 1 rest position shown back, so that during the working step I38 the document can be removed from the tray 10. Is the document a bank passbook or "a similar document and the information should be on one continued on the next page, the page

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reversed during operation 140 and the mode of operation returns to step 80, during which the Document is re-entered into the tray 10 to initiate a new operation.

In this way a printer is obtained which has an equalizer for clamping a document regardless of its thickness. Although in the above Description of the tappets 60 as a function of an engine and a cam arrangement. has been operated, of course this mechanism is also actuated by an electromagnet in a manner similar to that in connection with this one with the holding magnet 40 was explained. However, the mechanism shown in the figures is preferred because with it optimal strength and robustness can be achieved. The electrical control circuit shown in Fig. 4 was also given only to explain the invention, so that any other suitable control circuit can also be used. There are therefore various modifications of the in The embodiment illustrated in the figures and the description is conceivable and possible without thereby departing from the inventive concept.

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Claims (1)

Claims Compensation device for changing strengths of a printer having a movable printhead documents to be printed through a document (12) receiving chute (10), one side of which is supported by a pair of elongated feeler rods (14, 16) is given, which is used to form an opening (18) through which the document is in the shaft acting printhead (20) can go through with Are arranged at a distance from one another and precisely define the printing plane for the printhead, by means of an elongated Plate (74) which is arranged on the side of the shaft opposite the printhead and which is in the rest position at least for the most part outside the shaft is located, the width of the plate being greater than said opening and the shaft next to the plate for moving in the plate in the slot is open by a working prior to the operation of the printhead first means (44 ... 61) for bringing the platen into contact with the document in order to carry out a printing operation and press the surface of the document firmly against the feeler rods, making this surface exactly in the printing plane is arranged, and by a die. Second device (62, 65) holding the plate elastically in this way, that the plate is retractable at a certain pressure, whereby the plate the surface of the document in the printing plane and against the Fühlmeß rods with substantially even pressure regardless of the thickness of the document keeps pressed. 309847/0382 Compensation device according to claim 1, characterized by a third device (54-, 56), 'with which the plate (74-) can be returned to its rest position after the end of a printing process. 3- compensation device according to claim 1 or 2, g e mark calibrated by a fourth device (42) for detecting the insertion of a document (12) into the chute (10) and through a fifth device (4-0, 36, 38) for holding the document in dependence the fourth facility. 4. 'Compensation device according to claim 3, characterized in that. that the fifth facility (28, 34, 36, 38, 40) a holding device (36, 38) with a slot (36) receiving the document (12) and clamping means (38) for holding the document in the slot and moving means (34, 28), by means of which the holding device can be moved in a controlled manner in order to convert the document into a suitable one for printing To take position. 5. Compensation device according to claim 4; thereby g e mark calibrates that the clamping device (40) for the document (12) in the slot (38) is one of is an electromagnet controlled plunger (38). 6. Compensation device according to one of claims 1 to 5, characterized in that the first one direction (44 ... 61) for moving the plate (74) in contact with a document (12) a cam (54), a cam follower (56), means (48, 43) for moving the cam plate relative to the cam follower 309847/0382 to bring a high cam zone into contact with the cam follower instead of a low cam zone, and means (60, 61, 62) responsive to the movement of the cam follower with which the plate is movable. 7 · Compensating device according to claim 6, characterized in that the movement devices (60, 61, 62) for the plate (74) has a plunger (60) and a compression spring (62) which between the The plunger and the plate is arranged, this spring giving way to such an extent when it is with a document (12) engages, which changes with the thickness of the document. 8. Compensation device according to claim 7 »characterized in that the compression spring (62) is critical is dampened to bruises and vibrations during to prevent the printing process * 9. Compensation device according to claim 7 »marked by a device (44) operating after the end of the printing process for moving the Cam (54) opposite the cam follower (56) to again bring the low cam zone into contact with the Bring cam followers, and by means (66) that after returning the cam disk to its original Can be actuated to the plate (74) with the To bring document (12) out of engagement. 10. Compensating device according to claim 9, characterized in that g e k e η η ζ e i without t that this is the plate (74) 30984 7/0382 wegende device (66) is a compression spring in the Rest state the plunger (60) in the direction of the cam disk (54) pretensioned. 11. Compensation device according to one of claims 1 to 10, characterized in that a pair of cams (54 ·)> Cam followers (56) and devices responsive to movement of the cam followers (60, 61, 62) are provided., With the elements of each of these pairs at opposite ends the plate (74) are arranged, and that the means (44-) for moving the cam disc the movement of the pair of cams. 12. Compensation device according to one of claims 1 to 11, characterized in that a Control cam disk (53) is provided, which is controlled by the device (44) for moving the cam disk (54) is driven that a switch (59) controlled by the cam disk (53) is arranged next to it, that the control cam disk (53) has a pair of incisions (55j 57) at such rotational positions of this has that the switch is located next to such an incision only when the control cam either is in a position in which the plate (74) is held in its rest position, or the plate in a position for full engagement with 'the document (12) is moved, the switch the Device (44) for moving the cam disks switches on when the switch is not next to an incision is located. 13. Compensation device according to one of claims 1 to 12, gekennzeich.net that the print head 309847/0382 (20) is a wired printhead with a stroke of about 0.12 mm to 1.14 mm and that the sensing rods (14, 16) are arranged such that the printing plane from the print head by less than that Length of the print stroke is removed. 14. Compensation device according to one of claims 4 to 1J, characterized in that 'that the Devices (28, 34) for the controlled movement of the holding device (36, 38) for the document (12) in the idle state, the slot (36) is arranged in the shaft (10) somewhat below the detection device (42), that the holding device (38, 40) can be actuated as a function of the detection device (42) and holds the document in it when it is moved, and that the devices for controlled movement so are controlled that first the holding device in such a way is arranged that an additional line to be printed on the document "is located next to the print head (20) that the holding device and thus the document for each additional line to be printed can be advanced, and that the holding device can be returned to its rest position is when all lines to be printed on the document have finished printing. 309847/0382 Blank page