PRINTING DEVICE

Abstract: A printing device (18) intended for marking of objects (1) with a so-called bar code (47) comprising combinations of light and dark bars forming together an optically readable symbol. The printing device comprises a package of a plurality of thin lamellae (20) arranged parallelly in close proximity to each other. The lamellae are displaceable in said planes by means of current pulse operated actuating means (26) when being guided, in order to change the reciprocal positions of the lamellae end edges and to set the desired printing pattern at one side of the lamella package. Moreover, the printing device includes operating means (38), which are arranged to fix the lamellae reciprocally in the set position and to impart a reciprocating movement to the lamella package.

Description: Printing device This invention relates to a printing device of the kind defined in the preamble of claim 1. For identification and evaluation of information concerning commercial articles mainly labels or decorating prints have previously been used. However, the so-called bar code has also recently gained ground. The code comprises combinations of dark and light bars, so-called modules, which form together an optically readable symbol. The symbols are read mechanically using e.g. pen readers, fix readers or laser scanners. When using the new bar code, which is also called EAN (European Article Numbering) , special problems exist in marking of so-called weight items. These articles which can consist of e.g. meat, fish, cheese or fruit, comprise packages with i.a. individual prices. The equipment for these weight articles can include a balance, a clear text indicator, an adapting unit which can be included in a computer, as well as a bar code printer. It is now the object of the invention to provide a printing device making it possible to change the symbols of the bar code in a quick and simple manner as desired, e.g. in dependence of varying prices and weights. The construction of the printing device must then also be such that it will be possible to obtain a distinct print also on materials, e.g. corrugated cardboard, to which it is normally difficult to apply a print. In order that the bar code symbol might be read correctly the printing quality must always be within the tolerances of the EAN standards. The conventionally used cliches usually operate with inks that can flow out or leave easily. The lines of the bar code will then often be diffuse, which in its turn may lead to the bar code being wrongly interpreted or quite unreadable. By using the printing device of the invention the above disadvantages associated with known constructions are eliminated. This is achieved by the device of the in¬ vention being given the characteristic features defined in claim 1. - U EA The bar code is usually found in different dimensions. As the bars are to be very thin.it is suit¬ able to use metal lamellae. However, when using broader bars it is also possible to use plastic lamellae. The printing pattern of the package of lamellae represents the symbol to be transferred to the object. The lamellae end edges being in a moved forward or nonactivated position represents dark bars while the lamellae end edges moved back by the activation of actuating means re- presents light bars. Under certain circumstances the opposite condition can however also be realized. In the previous case the marking of the intended article is carried out with advantage e.g. by using a high quality ink ribbon arranged between the article and -the printing device. The invention is described more closely below in the form of preferred illustrative examples with reference to the enclosed drawing. Fig. 1 shows schematically the units that can be in- eluded in equipment for providing a bar code on objects. Fig. 2 is a perspective view of the essential parts of a printing device made according to the principles of the invention in connection with printing. Fig. 3 shows a perspective view of two of the lamellae in close proximity to each other in the construction illustrated in Fig. 2. Fig. 4 shows a top plan view of a modified embodiment of a lamella and guide axles cooperating with the lamella. In the various drawing figures like parts are indicated with the same reference numerals. The summary grouping according to Fig. 1 shows as examples the main parts of equipment in which the new printing device can be included. The reference numeral 10 relates to a computer comprising a writing and a weighing unit 12 and 14, respectively. It is possible to program the computer with the help of these units so that it can give information on each occasion in clear text about the actual price relative to measured weight. The computer 10 also includes an adapting unit 16 in which the information about the text en clair of the computer is converted into bar code statements. These are sent in the form of current pulses to the very printing- device 10, a figure in the code normally corresponding to transfer and/or not transfer of totally seven current pulses. By means of the printing -device 18 the intended object 19 can thereafter be marked with the intended, machine readable symbol. The printing device 18 shown in Fig. 2 comprises a plurality of thin rectangular steel lamellae which are similar to each other and arranged close to each other with parallel main planes. Elongated holes 22 are made uniformly in the lamellae 20; see Fig. 3. As all the lamellae are placed with their end edges in the same plane two passing holes 22 consequently extend through the package of lamellae. In the embodiment shown the holes are placed so that the extension of the longest diameter of the hole opening forms an angle of approximately 45 to the relative lamellae edges. Guide axles 24 extend through the holes 22. The two holes 22 and the guide axles 24, respectively, are identically the same, and each guide axle is made so that the lamellae 20 can be displaced separately when guided on the axles. The displacement is achieved by the influence of the actuating means 26, which consist of an electromagnet associated with each lamella 20, said electromagnet being guided via control pulses from the adapting unit 16 of the computer 10. As is- apparent from the drawing a metal wire element 28 is attached to the upper portion of each lamella 20. Each wire element 28 projects at one end of the relative lamella and supports the magnet element 30 associated with the electromagnet 18, said element being movable in a corresponding current coil 32. When a current pulse is transmitted from the adapting unit 1*6 to the electromagnet 18 the magnet element 30 is attracted with the result that the corresponding lamella 20 is moved backwards up¬ wards from a state nonactivated in the starting position. The printing surface of the lamella 20 will then be dis¬ placed relative to the total marking surface of the lamella package (directed downwards in Fig. 2) , which means that the lamella in a following printing operation will contribute with a light bar in the pattern surface of the lamella package. On the other hand, lamellae not receiving any current pulse will transmit dark bars in marking, an ink ribbon 34 e.g. being used. In order to achieve a rapid return of actuated lamellae 30 to the starting position at a desired point of time prestressing means in the form of plate springs 36 arranged to counteract the displacement of the lamellae from the starting position are utilized. The plate springs shown in the drawing - one for each lamella - can of course, if desired, be replaced with tension springs, which then act at the opposite side of the lamella package. As operating means to fix the lamellae reciprocally in a set position and to impart a reciprocating movement to the lamellae package a gripping claw 38 is utilized, which in the illustrative example shown includes a fork-shaped element with two similar fork portions 40 arranged to act on both sides of the lamellae package. The gripping claw brings about compression of the lamellae 20, and for this object there are special pressing elements 42 with wedge- -shaped pressing surfaces 44 on the outside of the outer lamellae of the lamella package. These pressing surfaces are intended to be brought into engagement with or be dis- engaged from the gripping claw 38, respectively, when this is moved parallelly to " the main plane of the lamellae. In order to make possible a good contact between the pressing elements 42 and the corresponding fork portions 30 the latter are provided with jaws 46 at their relative contact surfaces. The guide axles 24 are guided in the pressing elements 42 which in their turn are guided in the projection portions 41, ' 43 of the fork portions. Lateral locking is ensured by means of locking elements 49 rotatable at the pins 45 from a locking position. When printing a bar code the electromagnets 26 are now first pulse guided via the computer 10, resulting in that the lamellae 20 are moved to a desired position for ad¬ justing the intended pattern code. After this the fork portions 30 are moved downwards, which means that the claws 46 are made to engage the pressing elements 42 so that the lamellae are compressed and fixed relative to each other. At the continued .downward movement of the fork portions 40 the whole lamellae package is brought along and moved towards the ink ribbon 34 to press and print the relative code 47 against the intended article 19. After 5 printing the fork portions 40 as well as the lamellae package is returned from the object. At a returning move¬ ment the pressure of the fork portions against the press elements 42 is released and the lamellae 20' are unloaded. The gripping claw 38 described above can of course be 10 modified in several different manners. Thus, it can also include an arm with end portions movable relative to each other which are displaceable towards the lamellae package from its opposite sides in order to press the lamellae together. Guiding of the gripping claw can take place in S many different ways, e.g. by means of hydraulics, pneumatics or electrically. The plane surfaces of the lamellae 20 facing each other should be very fine to obtain a desired high EAN-tolerance according to standards. However, the lamellae must not 0 "adhere" to each other but it should be easy to move them rapidly to their intended positions. This is facilitated if the pressing elements 42 described above consist of permanent magnets. When the gripping claw 38 does not exert any pressure against the lamellae package the 5 lamellae 30 will repel each other due to the action of magnets. Instead of permanent magnets it is of course also possible to use electromagnets to obtain the same repelling . effect. As already mentioned above different materials can be 0 used for the lamellae 20. When making very narrow bars steel lamellae are utilized, as plastic and the like does not offer enough stiffness in this case. When marking piece gods and the like having big dimensions the bars should, however, be easily readable also at a certain S distance, and therefore the lamellae must be broader. In this case it is suitable, for economical reasons, to utilize plastic lamellae. When using plastic it is of course not possible to use permanent or electromagnets for separation of the lamellae, when these are not activated 0 by the gripping claw. Instead it is however possible to U EA design the guide axles as pipes 24' fed with compressed air, which is illustrated in Fig. 4. The holes 22' through each separate lamella 20' should then be bevelled 48 or recessed at one lamella side so that adjacent lamellae define between themselves air pockets, which communicate with the interior of the guide tubes 24' via pipe holes 50. This is especially apparent from Fig. 4. When utilizing the construction described above it is also possible to build the whole lamella package in a printing roller, where the lamella end edges intended for printing only form part of the surface of the printing roller. The other parts of the periphery of the printing roller can then be utilized as a usual stamp with figures and letters. Modifications of the printing device described above can of course be made within the scope of the following claims.

Claims: [received by the International Bureau on 29 September 1983 (29.09.83) original claim 1 has been amended, original claims 2 to 5 have been cancelled, claims 6 to 9 are new ] (amended) 1. A printing device for use when marking objects (19), particularly for marking with a machine readable so-called bar code (47) by means of a plurality of thin lamellae (20,20 r ) having parallel main planes, said lamellae being bound to each other in a lamellae package by means of coup¬ ling means (24,24*) for free movement in the main planes, respectively, within ranges limited by said coupling means, c h a r a c t e r i z e d in that actuating means (26) are arranged to enable mutual parallel displacement of the lamellae having printing edges on one side thereof to one of at least two positions in said main planes, respectively, for adjustment of a desired printing pattern, which is. formed, thus, by said printing edges adjustable to at least two different parallel planes by said parallel dis¬ placement, that means (38,40) are arranged to promote a . separating effect of the lamellae during the adjusting .step, and that operating means (38,40) are arranged to mutually fix the lamellae in the set position by pressing them together and to provide a relative reciprocal move¬ ment of the lamellae package and said objet (19). (new) 6. The printing according to claim 1, c h a ' r a c t e r- i z e d in that the lamellae consist of a magnetic material so disposed that they repel each other perpendicularly to the main planes. (n e w ) 7. The printing according to claim 1, c h a r a c t e r¬ i z e d in that the lamellae (20) consist of a magnetiz¬ able material and that magnets (44) are so arranged at opposite sides of the lamellae package that the lamellae repel each other perpendicular to the main planes. (new) 8. The printing according to claim 1, c h a r a c t e r¬ i z d in that the lamellae (20 ') consist of a non- -magnetizable material, e.g. plastic, preventing mutual adhesion thereof. (new) 9. The printing according to claim 1, c h a r a c t e r¬ i z e d in that air pockets are defined between adjacent lamellae (20 ') in which pockets a positive pressure exists so that the lamellae are forced to remove themselves from each other.

Inventors: SIMIC BORISLAV, SIMIC, BORISLAV
Applicants: SIMIC BORISLAV, SIMIC, BORISLAV
Application year: 1983
Main classification: G06K1
IPC codes: G06K1