TITLE
PRINTER FOR TYPING DESIRED CHARACTERS ON MANUALLY
ENTERED DOCUMENTS, SUCH AS TRAVEL AND TRANSPORT
DOCUMENTS, INVOICES, ETC., WHILE IN MOVEMENT. DESCPTPTTON
Field of the invention
The present invention relates to the field of printers and more precisely to a printer for typing desired characters on manually entered documents such as travel and transport documents, invoices, etc. , while in movement.
Description of the prior art Various types of printers exist for carrying out the function of printing desired characters on manually entered documents. There are, in fact, stamping and cancelling machines which are designed so that the document is entered into a slot and, once it reaches the correct position for printing, a punch blocks it in order to allow a printing head to operate. Upon completion of printing, the punch releases the document so that it can be extracted.
An essential characteristic of this type of printer is that the document is held still during printing since it is the printing head which shall move. Making the printing head moveable involves the incorporation of suitable means to move the head in correlation to the characters which are progressively typed on the document. These means, of various types not described in detail inasmuch as they are well-known, are sufficiently reliable and precise. However, they involve a greater complexity of the printers suited to these objectives.
Another inconvenience of printers of this type is
that while a very short time is sufficient for printing, a much longer time is normally needed for entering and extracting the document. In fact, the document is entered in a direction orthogonal to the line of characters to be printed and, therefore, it is necessary for the user to slide the document through the opening of the slot, enter it all the way, realize that the printing has taken place and extract the document. In situations such as the cancelling of tickets aboard a bus or at a train station, queues often form of people who, at the same time, wish to have their tickets cancelled. The seconds of waiting which pass between the extraction of one ticket and the entry of the next determine whether or not a queue will be formed. Notwithstanding the fact that the majority of people carrying out this operation do so on a daily basis, queues form all the same.
In order to avoid insofar as possible the formation of queues, in the similar field of magnetic cards, scanners have been created which provide for the entry of the card in a slot which runs longitudinally to the advancement of the person holding the card as he walks. The card is slid along the slot while a magnetic scanner contemporaneously reads the data encoded on it. Means for detecting the speed of advancement of the card are unnecessary since the scanner is able to read the data as long as the speed of advancement remains within a certain, sufficiently broad interval.
As regards printers of the above-mentioned type, on the other hand, none is known in which the printing of the line of characters occurs on manually entered documents in movement.
Summary of the invention The first object of the present invention is
therefore to provide a printer for typing desired characters on manually entered documents in movement.
The second object of the present invention is to provide a printer for typing desired characters on manually entered documents which does not require means for moving the printing head and which, therefore, is less complex and expensive than the currently existing printers of the same type.
The third object of the present invention is to provide a printer for typing desired characters on manually entered, moving documents which is also able to considerably reduce the waiting time for users.
These objects are accomplished by the printer according to the present invention the novel feature of which is that the printing head is associated with a decoder for detecting the speed of advancement of the document with respect to the head, the document being able to advance in a direction parallel to at least one line of characters printed by the printing head in correlation to the speed of advancement.
Preferably, the printing head does not move with respect to a printer support. The decoder is advantageously a roller connected to an encoder and rolling on the document, an element for pressing the document against the decoder and the printing head being provided to facilitate the rolling of the roller and allow for printing.
A slot into which the document is to be entered is advantageously defined by the pressing element and the support on which the printing head and the decoder are mounted.
According to a particularly preferred embodiment of the invention, the slot runs parallel to the direction of advancement of a person carrying the document so that
said person, without stopping, is able to advance the document by partially entering it in the slot and sliding it as he walks to accomplish the printing.
In order to check the presence, correct positioning and direction of advancement of the document, sensor means are provided which are connected, along with the decoder, to electronic means for the control of the printing head, which can be, for example, of an ink jet, thermal or needle type. Brief description of the drawings
Further characteristics and advantages of the printer according to the present invention will become apparent in the description which follows of one of its possible embodiments given as an example and not limitative, with reference to the attached drawings in which:
- figure 1 shows a schematic longitudinal sectional view of a printer according to the present invention;
- figure 2 shows a partially sectioned perspective view of the printer of figure 1;
- figure 3 shows a top plan view of the support of the printer of figure 1;
- figure 4 shows a view similar to that of figure 3 of a different embodiment of the support of the printer shown in figure 1; figure 5 shows a block diagram of the functional connections of the printing head, sensor means and decoder with means of electronic control;
- figure 6 shows a flow chart of the program means loaded on a microprocessor comprised in the means of electronic control;
- figure 7 shows a block diagram similar to the one in figure 5 for a needle type printing head.
Deππr-i ion of the preferred embodiment
- 5 - With reference to figure 1, a printer according to the invention for typing desired characters on manually entered documents in movement comprises a support 1 for a printing head 2, for example of the ink jet, thermal or needle type. On the support 1, a sensor 3, to signal the presence of a document 4, and a decoder 5, suited to roll on document 4 as it passes through a slot 6 defined by support 1 and a pressure plate 7 which faces support 1, are also provided. Plate 7 is resiliently connected to a fixed support 9 by means of springs 8 which press it with a pre-established force against support 1 so that document 4, when passing in slot 6, is in contact both with decoder 5 and head 2.
The pressure just described can be exercised, instead of by plate 7, by other pressure means such as dragging rollers, which are also resiliently suspended.
A preferred embodiment of the printer according to the present invention is shown in figure 2.' Upon passage of document 4 in slot 6 by a user who holds the document in his hand as he passes it through the slot, printing head 2, although fixed in place, prints a line 10 of characters on the face 4a of the document. The printing occurs in correlation to the speed at which document 4 advances in the direction of the arrow F since decoder 5, associated with printing head 2, has already detected the speed. Document 4 advances in a direction parallel to the line of printed characters 10.
According to the embodiment illustrated in figures
1 and 2, it is, therefore, possible for the user to accomplish the printing of line 10 by proceeding in a direction parallel to the direction of printing without stopping, keeping the document 4 in hand and sliding it in slot 6 in the direction of arrow F. This solution is particularly advantageous because it makes it possible
- 6 - to accomplish also the third object of the invention, i.e. the considerable reduction of time spent waiting for the printing on documents.
The second object of the invention is also accomplished since the printing head does not move with respect to a printer support and the user himself produces the relevant movement between the document and the head to allow for printing. The absence of means for moving the printing head, which are present in all the other known printers of this type, allows for a considerable simplification of the design.
A further advantage is the possibility of introducing document 4 in either of the two opposite directions of slot 6, using a single encoder able to distinguish the direction of advancement of the document.
Although reference has been made to a printer with slot 6 for the entry of document 4 parallel to the direction of advancement of the user, the invention can be applied also to traditional stamping and cancelling machines, with the entry and extraction of the document occurring through the same single slot. As shown in figure 4, with respect to the position described above and illustrated in figure 3, support 1 can be configured with printing head 2 and decoder 5 located side by side, with the addition of a further sensor 12 to the already provided sensor 3. In fact first sensor 12, upon detecting document 4, activates printing head 2, while second sensor 3 signals the end of the advancement of the document.
This solution, with respect to the previous one, even if does not provide the advantage of eliminating the entry and extraction time, still has the advantage of not needing the motorization of the printing head 2
which does not have to move since the movement relative to the document is provided by the document itself, with correlated printing made possible by decoder 5 as illustrated above. As described above, in order to check the presence, the correct positioning and the direction of advancement of the document, sensor means are provided connected, along with the decoder, to electronic means of control of the printing head, which can be, for example, of an ink jet, thermal or needle type.
In more detail, as shown in figure 5, decoder 5 and sensor 3 are connected to microprocessor control means 13. The control means command printing head 2 which can be, for example, of an ink jet or thermal type, by means of an appropriate driver 14 on the basis of the signal coming from sensor 3 through an amplifier 15 as well as on the basis of signals coming from decoder 5 through a decoder 16 of the direction of the movement of document 4. Control means 13 are able to operate on the basis of program means loaded in a memory 17.
These program means operate, for example, according to the logic of the flow chart illustrated in figure 6.
As already mentioned, the printing head 2 can be, for example, of an ink jet, thermal or needle type. In the last of these cases, the printing head, while not having to move, must comprise sliding means for an ink ribbon. Therefore, in the case of a needle printing head, the block diagram of figure 5 will be modified as indicated in figure 7, with the addition of a cartridge 18 connected to control means 13 by a driver 19 of a known type.
While up to this point reference has been made to a printer with a single printing head able to print only a single line of characters, the possibility of needing to
- 8 - print more than one parallel line on the same document can not be excluded. This need can be met by the present invention by using, for example, more than one printing head in parallel or a single printing head able to print more than one parallel line contemporaneously.