DE2932421C2 - Device for the production of a perforation matrix in flat material - Google Patents

Description

The invention relates to a device for

ίο Production of a perforation matrix in a flat area Material according to the preamble of the main claim, as already proposed in DE-OS 29 22 976 became.

Such a perforated sheet-like material is used in particular as a cigarette filter tip paper.

In the older application DE-OS 28 28 754 is a device for generating a variety of pulsating Rays, starting from a laser beam source, described. This is a rotating, optical Chopper provided. The focused laser beam is focused on along the axis of the Ray successive and at a distance 'from each other points on each in the {Partial areas reflecting and the beam deflecting surfaces to generate pulsating Rays directed. The pulsating rays obtained in this way are then applied to the sheet-like material in the transport level for creating the perforations

transferred directly. The rotating chopper discs, where the focused laser beam strikes are therefore at a fixed, predetermined angle to the plane of transport and therefore aligned to the flat material. The older application DE-OS 29 22 976 also describes a device for the production of a perforation matrix in two-dimensional material, in which starting from Multiple pulsating beams can be generated from a focused laser beam. These pulsating rays are passed through a common focusing lens as a focusing device and then onto the material web directed. The row and column perforations in these devices are complicated Facilities for performing precision movements required and also prepare vibrations and Relative movements of reflectors in the beam paths of the pulsating rays Difficulties because as a result, they can move in their reference plane or even out of it. This suffers from Uniformity of the perforations in the perforation matrix.

From US-PS 32 56 524 a laser recording device is known which contains beam splitting mirrors and a plurality of selectively movable mirrors which deflect the beams of the output laser beam split with the help of the beam splitting mirror and direct them onto a bit system, by means of which they are onto a recording medium for marking be steered by places. In Fig. 1 of US-PS 32 56 524 a single focusing lens serving as a focusing device is provided in the beam path. In the embodiment according to FIG. 2 of US Pat. No. 3,256,524, the lens system contains several lenses which are arranged at different distances from the plane of transport.
The invention is based on the object of designing a device for producing a perforation matrix in planar material according to the preamble of claim 1 so that it is uniform in a structurally simple and reliable way.

produces regular and uniform perforations in a moving sheet-like material.

According to the invention, this object is achieved by the characterizing part of the main claim.

Further advantageous refinements emerge from the subclaims.

In the device according to the invention, the cross-sectional area expansion is the pulsating generated Blasting in the transport plane: approximately evenly, in which the flat material moves. Those in the light paths of the pulsating rays generated arranged focusing devices have approximately the same focal length and approximately the same Distance from the transport level. To even out the light path of the generated pulsating Beams that are generated in offshore locations are provided with light-conducting devices, the generated pulsating beams on separate light paths to separate focusing devices to lead. The light-conducting devices contain reflectors for multiple reflection, so that the light path around the distance between the points for the generation of the pulsating rays ; "it can be that the light paths are roughly the same. Hence the pulsating rays come in the assigned ^ Focusing devices with approximately the same cross-sectional area at. Since the focusing devices have approximately the same focal lengths and approximately the same distances from the transport plane, the pulsing beams through the focusing devices on the transport plane with approximately however, they are much smaller cross-sectional areas on the moving two-dimensional Material directed so that perforations of the same size are reliably obtained in the sheet-like material.

In the embodiment of the device according to claim 2, rotatable light-guiding devices are provided, the easy adjustment of the position of the perforations in the perforation matrix without a Allow loosening of the individual reflectors. A simple adjustment of the lengths of the Light paths made possible.

In the devices according to claims 3 to 6, a pipe arrangement is specified, which is easy trained and employed.

The design of the device according to claim 7 is a special design again with which have the lengths of the light paths adjusted appropriately.

The invention is explained in more detail below using examples with reference to the drawing. In this shows

F i g. 1 is a schematic view in the form of a block diagram of an apparatus for manufacturing a perforation matrix in two-dimensional material,

F i g. 2 shows a schematic view of the panes from FIG. 1, each of which ends in partial areas and forming first and second surfaces respectively deflecting the beam,

Fig. 3 and 4 diagrams to clarify the no Beam path in the design of the device for producing a perforation matrix in one sheet-like material according to FIG. 1,

5 shows a schematic view of a further embodiment of an apparatus for manufacturing a perforation matrix in flat material with several additional serving as reflectors Discs,

F i g. 6 is a schematic view to illustrate the configuration of the disks in the device according to Fig. 5, and

F i g. 7 is a schematic view for explaining FIG variable perforation cornices, which differ with the Device according to FIG. 5 can be created.

Like fig.! shows, becomes a sheet-like planar Material advanced in a transport plane IO and wound up by a take-up drum 12. the Take-up drum 12 is driven to rotate by a drive unit 14 at a speed which is dependent on a control signal of a line 16 which contains a potentiometer 18.

A potentiometer 20 supplies a further signal to a line 22 for controlling the drive unit 24 a light reflector assembly 26, which has a shaft 28, soft by the drive unit 24 to Rotation is driven, also serving for beam deflection discs 30 and 32 and a spacer 34, that au 'the shaft 28 with the disks is keyed for rotation therewith.

A laser 36 generates a continuous output beam 38 which is focused through a lens 40 and • hits targets M> and 32. The one through the panes 30, 32 reflected and deflected rays pass through light-guiding devices 42 and 44, which are located on Output each have a focusing device 46 or 48 and through a fixed frame 50 to independent rotation about axes 52a and 54a of the pulsating beams.

F i g. 2 schematically shows the disk 30 and the disk 32 arranged side by side, the latter being to the right of the disk 30 in FIG. 1 is shown. The disks 30, 32 are keyed onto the shaft 28 at a point at which the lines 56 and 58 are in a common plane with the shaft axis 60. In the case of the FIG. In the embodiment shown in FIGS. 1 and 2, the panes 30, 32 have light-permeable surfaces 62 and 64 which are provided at regular intervals and which are offset from one another and which delimit reflective facets as partial areas 66 and 68 between them. If forty-five such facets 66 are used, each facet 66 extends over four degrees of arc (angles 70 and 76) and each translucent portion 62, 64 extends over four degrees of arc (angles 74 and 72). When the front edge of the translucent portion 62a is in alignment with the line 56 and the translucent portion 64a is spaced from the line 58 by the angle 76, the disks are properly aligned for the alternating reflection of the laser beam. The focused ί iserstrahl 38 passes through the light-permeable sub-area 62a in order to be reflected on the facet lying in the clockwise direction of the permeable sub-area 64a. The transparent partial areas are openings in the panes 30, 32 of a size sufficient for the laser beam to pass freely through. The spacer 34 is of such a dimension along the axis 60 chosen that the discs 30 and 32 are at the desired locations of the origin ion the disc facets reflected rays modified. Although the disk 32 can also be produced without translucent partial areas, since it is the last disk from the laser, the arrangement described prevents an undesired reflection of the laser output beam by the disk 32 during the confrontation of the facets of the disk 30 with the

Laser beam softened, d, left, the laser output beam crossover passes beyond the disk 28 only through the openings in the disk 32.

As can be seen from FIG. 3, each confrontation of a facet of the disk 30 with the beam 3S leads to the propagation of a modified version of the laser output beam, which modified pulsating beam 52 has a central axis 52a, ie an axis of symmetry which is parallel due to the orientation of the disk 30 runs to the optical axis 42a of the light-guiding device 42. The beam 52 has outer beams 526 and 52c which diverge in opposite directions from the beam center axis 52a. The virtual image or the origin of ray 52 is shown at 52c /.
Each time a facet of the disk 32 is confronted with the beam 38, a further modified pulsating beam 54 is generated which has a central axis 54a '(beam symmetry axis) which is parallel to the optical axis 44a of the light-guiding device 44. The ray 54 has diverging outer rays 546 and 54c and a point 54c / for the virtual image or origin. Both the distance between the disk 30 and the jet origin 38o along the axis 38a and the distance between the disk 30 and the original position 52c / along the axis 52a are designated by dx>. In the same way, d ₃₂ denotes both the distance between the disk 32 and the beam origin 38o along the axis 38a and the distance between the disk 32 and the original position 54c / along the axis 54a. The distance between the disk 30 and the disk 32 along the axis 38a is denoted by (/,.

As can be seen from FIG. 4, the light-guiding device 42 has planar reflectors 426 and 42c. The reflector 42c is in alignment with the focusing device 46 provided at the exit, which has an entrance plane 46a. The light-guiding device 44 has flat reflectors 44b and 44c. The reflector 44c is in alignment with the focusing device 48 provided at the exit, the entrance plane of which is also plane 46a.

If the focusers 46 and 48 were brought into direct alignment with the disks 30 and 32 and the reflectors 42b, 42c, 44b and 44c were omitted, there would be a distance D to each of the light paths extending from the disk to the focuser. The light path from the laser beam origin 38o for the beam reflected by the disk 30 would then be c / 30 + D and for the beam reflected by the disk 32 c / 30 + D _s + D. Taking into account the reduction factors, ie the ratio of image size to Object size, the present arrangement gives different reduction factors based on such light paths of different lengths. Achieving the same perforation hole sizes for each beam is obviously not achievable with such an arrangement in which a compensation for the light paths of different lengths is not achieved, for example through different focusing properties of the focusing devices 46 and 48 44, reduction factors of the same size for each pulsating beam and approximately the same perforation hole sizes can be achieved without providing very different optical systems.

A distance d ″ is selected along the axis 52a between the disk 30 and the reflector 42b. A distance db is chosen along an axis which is parallel to the beam axis 38a between the reflectors 42b and 42c. A distance d _c is chosen along an axis which is parallel to the axis 52 a between the reflector 42 c and the entry plane 46 a of the focusing device 46. Since the divergence of the beam 52 is constant over the entire passage through the light-guiding direction 42 and is determined by the divergence of the beam 38, distances along the axis 38a, which correspond to the position of the reflectors 426 and 42c, can be plotted by the divergence of the beam 52 to be determined in the course of its passage through the light-guiding device 42. The reflector 42c is, for example, from the point of origin 52c / by the sum of the distances

J30, d _a and db removed. The line 42c 'drawn across the beam 38 denotes the divergence that occurs at the reflector 42c at such a composite distance. The divergence at the plane 46a is obtained in that along the axis 38a the composite distance c / 30, d _s , db and d _{c is} plotted, which divergence is indicated by the line 46a 'along the axis 38a. The virtual image 52c / is removed from the reflector 42c by the sum of the distances i / 30, d _s and ct.

The distances dj, db ' and de of the light-guiding device 44 correspond in their nature to the distances da, db and de. The divergence at the reflector 44b is indicated by the line 44b' along the axis 38a, ie at a distance from the origin 38 ₀ , the is equal to the sum of c / 32 and c / a '.

In the case of the virtual image 54c / with an identical distance from the focussing entry plane 46a as the virtual image 52c /, an identical cross-sectional area is obtained for each beam at the plane 46a. In other words, the same reduction factors occur in the beams which are directed from the origin 38o to the transport plane i0 of the sheet-like material, regardless of whether the laser beam is reflected by the disk 30 or the disk 32. For this purpose, the composite path length for the rays reflected by the disk 32, ie the sum of c / 30, ds, d _a ', db and de becomes equal to the composite path length given above for the rays reflected by the disk 30, namely the Sum of c / 30, d _a , dbundde, made.

As a further example, it is assumed that the focusing device 48 specified at the output is located in overlap with the disk 32 (reflectors 44b and 44c omitted). The direct return path length is now D for the beam reflected by the disk 32 to the focusing device 48. The composite path length of this beam is c / 30 + d _s + D. For the same optical path lengths, simply move the deflectors 42b and 42c at a distance d _s from one another, so that the composite path length of the beam reflected by the disk 30 is also c / ₃₀ + d is _s + D.

In Fig. 5 four disks 30 ', 32', 78 and 80 are longitudinal of the shaft 28 by spacers 34, 82 and 84 from each other. Additional light-guiding devices 86 and 88 have focusing devices 90 and 92 on the beam exit side. Modified pulsating ones Rays 94 and 96 are defined by the facets as reflective portions of the panes 78 and 80 generated. The beam 82 which narrows about an axis of symmetry that coincides with the optical axis 86a of the light-guiding Facility 86 coincides. The beam 88 diverges about an axis of symmetry that coincides with the optical axis

88a of the light-guiding device 88 collapses, each light-guiding device 42, 44, 86 and 88 has the shape of a tube. The tube 88 is typical of all tubes and comprises vertical sections SSb and 88c, a horizontal section SSd and reflectors 88e and 88 /: The horizontal section SSd has screwed end connections to reflector-bearing blocks 88e-1 and 88e-2, which allow fine adjustment of the Total tube length is obtained and the length of the light path can be changed from its specific length, so that the same cross-sectional areas of the rays are obtained when they exit from the light-conducting devices 42,44,86,88 designed as tubes.

Flat reflectors 88e-3 and 88e-4 are releasably attached to the blocks 88e-1 and 88e-2. The focusing device 92 is fastened with its lens holder 92a in a housing 92b which is screwed to the vertical section 88c, whereby the adjustment of the lens position with respect to the transport plane 10 is made possible. The tubes 40, 42, 86 and 88 are jointly supported by a housing 98 with the horizontal and lower vertical sections being rotatable about the upper vertical section. The tubes are chosen so that they have an inner diameter which is greater than the maximum cross-section of the rays passing through them, i. In other words, the pipes do not intercept or reflect the rays. The tubes therefore serve as a housing in which the reflectors are supported in such a way that successive reflectors, for example 42b and 42c (FIG. 4), are kept in a fixed spatial relationship to one another, and both together around the central axis de? Beam are rotatable, which hits the first reflector. As a practical safety measure, the pipes also serve to contain the rays and to keep operational disruptions to a minimum.

F i g. 6 shows the designs of the disks 30 ', 32', 78 and 80. If all of the disks follow key lines 100, 102, 104 and 106 lying in a common plane are wedged and 45 facets as reflective partial areas per pane as according to the device 1-3, the facets extend as reflective portions of all panes each over two arc degrees and the openings of the same extend over six arc degrees. The facet 108 the front edge of the disk 32 ′ coincides with the wedging line 102 in the clockwise direction. The facets 110, 112 and 114 of the disk 30 ', 78 and 80 are located with their front edges clockwise at a distance from the wedging lines 100,104 or v /. 106 by two, six and four degrees of arc 116, 118 and 120. With this configuration it is found that a clockwise rotation of the shaft 28 is a successive one Propagation of modified pulsating rays 54, 52, 96 and 94 (Fig. 5) result.

In Fig. 7, the circular paths 122, 124, 126 and 128 determine the possible positions of the focusing devices at the end of the tubes 42, 44, 86 and 88. As indicated, the paths interfere with one another in their extension to the left, while they do not interfere with one another in the remaining area on the right. In an exemplary setting to produce a perforation matrix, the tubes are set so that tube 42 forms row 130 of perforations, tube 44 forms row 132, tube 86 forms row 134, and tube 88 forms row 136. The distance Si between the rows 130 and 134 is obtained by adjusting the tubes 42 and 86 relative to one another. The distance Si between rows 132 and 136 is achieved by adjusting the tubes 44 and 88 with respect to one another. The settings of the tubes 42 and 44 also result in distances Si and S _{4 of} the rows 130 and 132 from the center line of the transport plane 10. The perforation arrangement shown can be used, for example, in the manufacture of cigarettes for perforating the filter tip paper. Usually opposing tobacco rod sections and an intermediate double filter member are brought together end to end and perforated tipping paper (web 10) is applied to bond the tobacco rod sections and the intermediate double filter member together. A section is then made symmetrically to the whole, ie along the center line of the transport plane 10. In this way two separate cigarettes are made, each having concentric spaced rows of perforations equidistant from the filter end.

A perforation pattern change can be achieved in a simple manner that the tubes or light conducting facilities are to be re-employed. the Perforation density in such rows is determined by the settings of the rotation speed of the respective Disc arrangement and the feed speed of the web adjustable. The hole size will be below the Rows made completely even in the manner described above, by making the light paths the same length be made.

7 sheets of drawings »30 235/410

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Claims (7)

Patent claims: I. Device for the production of a perforation matrix in planar material during its advance in a transport plane, with a source that focuses a laser beam! generated, which strikes at two successive first and second points located at a distance from one another along the axis of the focused beam on first and second surfaces reflecting in partial areas, each deflecting the beam to generate a first and a second pulsating beam and with a focus device for the first and second pulsating beam on their way to the transport plane, characterized in that the focusing device for the pulsating beams contains first and second focusing devices (46, 48) with approximately the same focal length, which are at approximately the same distance from the transport plane (10) are arranged, and the first and second pulsating beam (52, 54) in the transport plane * ·. > · -: | f (10) focus, and that photoconductive devices, ΐ (42,44) are provided, each of the first and; the two pulsating beams (52, 54) separately ,. Via first and second light paths from the first and second point to the respectively assigned first and second focusing devices (46, 48), in which the respective beam cross-sectional areas are always comparable, the light-guiding devices (42, 44 ) further reflectors (426 ,, "42c) in the first light path for a multiple reflection:! xion of the first pulsating beam (52) included \% i- and the first light path is given a length ': \.: ^ which is the distance between the first (30) and the second point (32) is greater than the length of the second light path. 2. Device according to claim 1, characterized in that ■■ "■■ is that in one or both of the light paths ,:. In each case two reflectors (42b, 42c, 44b, 44c ) carried by the light-conducting devices "'(42, 44) are arranged, each of which is about the axis (52a, 54a) of the respective one of the two pulsating beams (52, 54) are rotatably mounted. 3. Apparatus according to claim 1 or 2, characterized in that the light-guiding devices are pipes (42, 44) which enclose the respective light path and in which the reflectors (42b, 42c, 44b, 44c) are mounted. 4. Apparatus according to claim 3, characterized in that the first focusing device (46) on the associated pipeline (42) is mounted so as to be movable in translation relative to this. 5. Apparatus according to claim 3 or 4, characterized in that each pipeline (42,44) has one first section in the area of entry of the respective at the assigned point (30, 32) reflected and deflected pulsating beam (52, 54), a third section in the area of the Beam exit in the direction of the transport plane (10) and a second section between the first and third sections. 6. Apparatus according to claim 5, characterized in that the reflectors (42b, 42c ·, 44b, 44c) are each attached to the connection points between the first and the second and between the second and the third section of the respective pipeline (42, 44) are. 7. Device according to one of claims 4 to 6, characterized in that the second section at least the first pipe (42) is adjustable to adjust the length of the light path.