EP1001874A1

EP1001874A1 - Method and device for sticking two halves of a dvd (digital versatile disc)

Info

Publication number: EP1001874A1
Application number: EP98943858A
Authority: EP
Inventors: Martin Eichlseder
Original assignee: Krauss Maffei Kunststofftechnik GmbH
Current assignee: KraussMaffei Technologies GmbH
Priority date: 1997-08-06
Filing date: 1998-08-06
Publication date: 2000-05-24
Also published as: US6634405B2; CA2299255A1; WO1999007542A1; DE19835660A1; US20010030012A1; US6425968B1

Abstract

The invention relates to a method for sticking two halves (23, 24) of a dvd (digital versatile disc). Said halves are held at a distance from each other so that a gap forms between them. The adhesive (36) is then introduced into said gap and is spread over both halves. The invention is characterised in that the adhesive is introduced via the central hole in the DVD by means of e.g., L-shaped metering needles (63) which are pivotably guided in a central pin, said pin dipping into the central hole (51), or flexible plastic needles which are guided in a guiding tube in such a way that they can move. Introducing the adhesive via the central hole means that the adhesive can flow freely out of the metering needle as the DVD halves (23, 24) turn. There is no build-up of adhesive in front of the metering needle and the sticking process can continue until the spinning process is complete, without any interruption of the application of adhesive.

Description

Method and device for gluing two DVD (Digital Versati le Disc) half sides

The invention relates to a method for gluing essentially rotationally symmetrical plates, in particular based on polycarbonate, which have a central recess and devices for carrying out the method. The preferred field of application of the present invention is the gluing of DVD half-pages. Here two 0.6mm thick information carrier half sides have to be glued together. The half sides are kept at a distance such that a gap is formed between them, the adhesive being introduced into the gap and the adhesive being distributed over the two half sides in such a way by suitable rotation of the two half sides that these are completely covered with adhesive. The different versions of the DVD with a diameter of 120mm (a diameter of 80mm is also possible), such as DVD 5, 10, 9 and DVD 18 in the possible types such as DVD-Audio, DVD-Video, DVD-Rom, DVD-R and DVD-Ram involve a number of difficulties when gluing. Particularly noteworthy are radial and tangential bumps (radial tilt and tangential tilt) as well as overall a dirty bond, in particular a non-uniform adhesive layer or bubbles in the adhesive layer. Bubbles in the adhesive layer are particularly critical, since they result in the failure of the DVD, in particular in the case of DVD 9, since there are two information levels on the latter and the second information level is read out through the adhesive layer.

Various processes for producing DVD ^{'s are} known from the prior art. In so-called "hot melt bonding", the adhesive becomes hot and viscous a roll on each side of the DVD. Then the two half sides are joined and pressed together. With this method, the risk of blistering and, overall, an impure adhesive layer is particularly high, so that this method is not suitable for the production of a DVD 9. In "UV screenprint bonding", the two sides of the DVD (as in hot melt bonding) are provided with adhesive and then joined and pressed. In contrast to "hot melt bonding", the adhesive is applied in this case using the screen printing process. This method essentially has the same problems as with "hot melt bonding", namely an impure adhesive layer and blistering. There may also be problems with the flatness of the plate (radial tilt, tangtial tilt). This process is described in a publication by ODME.

Another method is "UV capillary bonding" as described in a product brochure from Toolex Alpha. In this process, the two sides of the DVD are kept at a distance with vacuum plates and bent at the same time (Fig. 4-5 in the brochure). The glue is fed through a dispenser needle, which is inserted up to about half the radius of the DVD into the gap between the two sides of the DVD. Adhesive is fed in at an average radial distance during one revolution. The dispenser needle is then removed from the gap and the vacuum is released. The "bent" DVD half-pages now return to their parallel position and the adhesive is distributed inwards and outwards by capillary forces. A disadvantage of this method is that there is a risk of cracking of the sputtered metal layers (with which the laser light is reflected) due to the bending. There is also a deep insertion of the dispenser needle into the gap the risk of damage to the surfaces of the DVD half-sides. Finally, it should be noted that the rotating DVD presses the centrifugal force of the applied adhesive against the dispenser needle and causes a "glue jam" in front of the dispenser needle.

The closest state of the art is "UV spin coat bonding" as described in a Panasonic product description. In this method, the DVD half sides are kept parallel to one another and spaced apart. To apply a strand of adhesive, a dispenser needle is inserted from the outside into the gap and close to the center of the DVD. An adhesive strand is applied near the center during a rotation. Then the dispenser needle is guided out of the gap and the adhesive is spun off by rotation, as a result of which it is distributed over the two half sides. With this method it can be assumed that the strand of adhesive touches both half sides, so that a relatively bubble-free adhesive layer is produced when spun off. A disadvantage of this method, however, is that the dispenser needle must be inserted close to the center. Therefore, even with this method, there is a risk that the half sides of the DVD will be damaged. To avoid this, a precise mounting of the DVD half-sides and a precise guidance of the dispenser needle are required, which requires a corresponding outlay on equipment. In addition, when the strand of adhesive is applied, the centrifugal force of the adhesive acts against the adhesive emerging from dispenser needles, as a result of which the flow of the adhesive is disrupted. Furthermore, it is necessary that the dispenser needle must be guided out of the gap by spinning off before the adhesive is distributed, which is associated with an additional step. In contrast, the invention has for its object to provide a method with which two sides of the DVD can be glued securely and without bubbles and which is also suitable for other rotationally symmetrical plates, in particular based on polycarbonate, which have a central recess. Another object of the present invention is to provide devices with which the method can be carried out. This object is achieved with respect to the method by the features of claim 1 or claim 2. Advantageous refinements of the method can be found in subclaims 3 to 16. The main advantage of the invention is that by supplying the adhesive via the central recess of the Adhesive can flow out from the feed element, for example a metering needle, without interference. This means, for example, that there is no jam of adhesive in front of the metering needle and further process steps can be initiated earlier. Overall, the gluing process can be carried out without interruption from the glue application to the end of the spinning off. The embodiment according to claim 5 has the advantage that the dispensing needle only has to penetrate a little into the gap between the two half sides of the DVD, so that the risk of damage to the surface can be largely ruled out. By setting a suitable wedge angle (claims 11 and 12) it is achieved that after the adhesive application by a slight increase in speed (depending on the back pressure of the gap) the adhesive is distributed evenly and symmetrically in this wedge. Before the actual spinning, there is an identical initial situation in every point on the half-side, so that the flow front speed is the same in all directions and bubbles cannot be trapped by leading adhesive. By suitable design of the exit Opening the dispenser needle can ensure simultaneous wetting of the DVD half sides when applying the adhesive. The invention is described in more detail below on the basis of various exemplary embodiments and with reference to FIG. 1. Show it:

Fig. 1 first embodiment of a bonding station according to the invention;

Fig. 2 is a view in the direction of arrow A in Fig. 1;

Fig. 3-7 method steps in the bonding of the DVD half-pages according to the invention;

Fig. 8 variant of the upper centering bolt;

Fig. 9 section at height AA 'through the centering pin in Fig. 8;

Fig. 10 section at height BB 'through the centering pin in Fig. 8;

11 second embodiment of a bonding station according to the invention;

FIG. 12 detail from FIG. 11 in an enlarged representation;

13 Central bonding with a symmetrical, wedge-shaped gap;

14 central bonding with asymmetrical, wedge-shaped gap;

15 ac different outlet openings of the metering needle in cross section; 16 a, b outlet opening with different lengths above and below, a = side view; b = supervision.

1 shows a first embodiment of a bonding station according to the invention. A base plate 33 carries a spindle 21 with a spindle drive 22 and a spindle housing 20 to which a holding bracket 19 is fastened orthogonally to the spindle axis. A substantially cylindrical bearing housing 9 is attached to the outer edge region of this holding bracket 19, in the lower edge region of which a ball bearing 11 is inserted, which in turn carries a hollow cylindrical bearing block 10, on the underside of which the upper vacuum plate 17 is fastened, so that it is opposite the bearing housing 9 and the bracket 19 is rotatably mounted. On the underside of the vacuum plate 17 there are an inner circumferential vacuum groove 52 and an outer circumferential vacuum groove 53, which are connected to a vacuum channel 55. This runs inside the upper vacuum plate 17 in the radial direction and further through the hollow cylindrical bearing block 10 inwards in the direction of the cylinder axis to an exit point 56. Since the vacuum channel 55 is produced through a bore beginning at the edge of the vacuum plate, there is a hole at this point Closure plug 18. On the outer edge of the upper vacuum plate 17, outside the area claimed by the upper DVD half-side 23, a driver pin 14 is provided, which is resiliently mounted via a spring 15 in a spring cage 16 and with which when the top and bottom are moved together Vacuum plates 17, 25 a frictional connection between the two vacuum plates can be made. The lower vacuum plate 25 is preferably provided on its outer edge in the manner of a gearwheel with U-shaped recesses which serve as driving grooves and into which the driving pin 14 can snap when the vacuum plates 17, 25 move together. On Upper centering pin 5 extends from above through the retaining bracket 19, the bearing housing 9, the hollow cylindrical bearing block 10 and the central recess 60 in the upper vacuum plate into the space between the two DVD half sides 23 and 24. This centering pin 5 is by means of a clamping nut 6 attached to the bearing housing 9 and thus to the bracket. A vacuum channel 50 runs inside the upper centering pin 5, which is guided radially outward at the level of the exit point 56 of the bearing block 10 and ends in a circumferential annular groove 57 corresponding to this exit point 56, with a vacuum-tight seal between the centering pin 5 and the Bearing block 10 sealing elements 65 and 66 are provided above and below the annular groove 57. In addition, the centering pin 5 has an adhesive suction channel 51, which begins at the lower plate-like end of the centering pin 5 (see FIG. 2) and extends to the upper area thereof, where it is connected to a suction device (not shown). A recess 61, in which an L-shaped metering needle 7 lies, preferably a steel needle, runs parallel to its axis in the surface of the centering pin 5, the foot of the L, ie the end piece 63 of the metering needle 7 lying parallel to the DVD half sides, lies in a U-shaped recess 62 at the lower end of the centering bolt 5 (cf. detailed view in FIG. 2). Under the end piece 63 of the metering needle 7 there is an adhesive collecting plate 39 which is continuously sucked off via the adhesive suction channel 51 connected to a vacuum, so that the bonding station is not contaminated with adhesive drops. The metering needle 7 is supplied with adhesive via a metering line 8. By means of a clamping screw 1, a clamping nut 2 and a cutting ring 3, the metering line 8 can be fixed at the desired height with the metering needle 7. By means of a compressed air actuated (54) attached to the centering pin 5 Rotating cylinder (rotary loader) 4, the metering needle 7 can be rotated about its axis, so that the kinked end piece 63 of the metering needle 7 can be pivoted in the space between the DVD half-sides 23, 24. A vacuum pump to be connected to the connection point 64 of the vacuum channel 50 is not shown. Since the vacuum channel 50 is produced analogously to the vacuum channel 55, a plug 18 is also required here to seal the beginning of the bore.

At a distance below the upper half of the DVD 23 there is a lower vacuum plate 25 with a central recess 35 and with an inner vacuum groove 52 and an outer vacuum groove 53, which are connected to a vacuum pump via vacuum channels (67, 50). The vacuum plate 25 is fastened on the cylinder hat-shaped housing 26 of the lower centering pin 27, which in turn is seated on the drive shaft 31 of the plate drive 32 which is preferably attached to the base plate 33. The lower centering pin 27 is resiliently mounted in the centering pin housing 26 via a spring ring 30 and a spring 28 and is stabilized in its axial direction by a guide pin 29. Below the outer edge of the lower vacuum plate 25 there is a channel 34 for collecting excess adhesive.

The procedure for gluing the DVD half pages 23 and 24 is as follows. First, the two DVD half sides 23 and 24 are inserted into the bonding station by a handling system, one (upper) DVD half side 23 being fed to the upper vacuum plate 17 and the other (lower) DVD half side 24 being fed to the lower vacuum plate 25. The two DVD half-sides 23, 24 are centered by the centering pins 5 and 27 via the central recess and are held on the vacuum plates 17, 25 by a vacuum in the vacuum grooves 52 and 53 (FIG. 1). Alternatively or additionally The upper half of the DVD 23 can also be centered over the outside diameter, for which purpose the upper vacuum plate 17 has a recess for receiving the upper half of the DVD 23, which corresponds to the diameter of the DVD and has a depth corresponding to the thickness of the half of the DVD 23. Then the lower centering pin housing 26 with the lower vacuum plate 25 is set in rotation by the plate drive 32 via the drive shaft 31, the number of revolutions being set as required for the adhesive application (approx. 6000 ° / min to 36000 ° / min) . The upper vacuum plate 17 with the upper DVD half-side 23 is now moved down to the desired position (FIG. 3) due to its connection to the retaining bracket 19 by a spindle 21 with the associated spindle drive 22, in which the DVD half-sides 23 and 24 have the necessary distance from each other for optimal adhesive application (approx. 1-2 mm). During this downward movement, the upper centering pin 5 dips through the lower half of the DVD 24 and presses the lower spring-loaded centering pin 27 back. In addition, the spring-loaded outer driving pin 14 is pressed against the lower vacuum plate 25 and engages in the next driving groove arriving. At the same time, the end piece 63 of the metering needle 7 is pivoted by 180 ° from the center of the DVD by means of the rotary cylinder 4 and is now in the position for introducing the adhesive (adhesive application position) between the DVD half-sides 23 and 24. By pivoting the end piece 63 the dispensing needle 7 by angle <180, the application angle can be changed. Since the lower vacuum plate 25 is already rotating at the adhesive application speed, the upper vacuum plate 17 is also set in rotation by the driver bolt 14 with the same number of revolutions, so that it rotates synchronously with the lower vacuum plate 25. As soon as the dosing needle 7 or its end piece 63 is in the adhesive application position, the dosing process is started and adhesive 36 is fed between the DVD half-sides 23 and 24. The dosage of the adhesive 36 is carried out volumetrically. The exact amount required is applied during about one revolution. The two DVD half sides 23 and 24 are wetted simultaneously when applying the adhesive 36. After the adhesive application has ended and there is thus a self-contained strand of adhesive 37, the metering needle 7 or its end piece 63 is immediately pivoted back through 180 ° into the rest position (FIG. 4). At the same time, the speed on the disk drive is increased (to approximately 100,000 ° / min to 200,000 ° / min) and the adhesive 37 is thrown outwards. Parallel to the speed increase, the upper vacuum plate 17 is moved further down with the spindle drive 22 and both sides of the DVD are pressed together (FIG. 5). The adhesive is spread over most of the DVD surface. The capillary action is supported and the distribution of the adhesive 36 is accelerated by the simultaneous pressing and spinning. When a predeterminable minimum distance between the two vacuum plates 17, 25 is reached, the vacuum is switched off at the upper vacuum plate 17 and the upper plate is moved upwards by the spindle drive 22 (FIG. 6). The upper half of the DVD 23 remains on the lower half of the DVD 24. Parallel to this, the lower centering pin 27 is pressed upwards by the spring 28 and now centers both DVD half sides 23, 24. Alternatively, the vacuum on the upper vacuum plate 17 can be switched off when the DVD half sides are pressed together. In order to distribute the adhesive homogeneously up to the outer edge of the DVD, the spin speed is increased further (to approximately 500000 "/ min to 900 000 rpm). After the distribution of the adhesive 36 has ended, the DVD is placed on the same vacuum plate 25 under the UV lamp 38 clocked, where the adhesive 36 hardens (Fig. 7). After the curing has ended, the DVD is removed from a handling system and one Test device supplied, where it is checked for optical and dimensional errors by means of a laser scanner.

8 to 10 show an alternative embodiment of the upper centering pin 5 shown in FIGS. 1 and 2. In a modification of the centering pin 5 from FIGS. 1 and 2, there is a web opposite the outlet opening of the end piece 63 of the metering needle 7 (in the rest position) 58 is provided, against the inside of which the end piece 63 is moved when it is turned back into the rest position, so that the opening of the end piece 63 is closed and no excess adhesive can get into the bonding station. For safety's sake, however, the adhesive collecting plate 39 and the adhesive suction channel 51 can be retained.

11 and 12 show as a second embodiment an inventive bonding station with an axially displaceable metering needle. The lower part with lower vacuum plate 25, centering pin housing 26, centering pin 27, spring 28, guide pin 29, spring ring 30, inner vacuum groove 52, outer vacuum groove 53 and the vacuum channels 67 and 50 is identical to the corresponding lower part from FIG. 1. as in the first embodiment - on the outer edge of the upper vacuum plate 17, a driving pin 14 is resiliently mounted (15, 16) and can engage in driving grooves on the edge of the lower vacuum plate 25. In the upper area of the bonding station, a bearing housing 9 is attached to the holding bracket 19, which is connected to the spindle 21 (not shown here) in the edge area of the holding bracket 19. In the lower area of the bearing housing 9, a ball bearing 11 is attached to its outer circumference and secured with an inner spring ring 13, which in turn carries a bearing block 10 (secured with an outer spring ring 12), in the lower edge of which the upper vacuum plate 17 is inserted and fastened , for example with a suitable adhesive. About the gluing process of the DVD half-sides 23 and 24 and to be able to optimize the process sequence on the basis of the results, the upper vacuum plate is made of glass and the holding bracket 19 and the bearing housing 9 are made with recesses 48 through which the glass vacuum plate 17 (and itself an annular part 49 is glued to the upper vacuum plate 17, in which a vacuum channel 68 runs, which in turn runs with the vacuum channel 55 in the upper vacuum plate 17 and secondly with the vacuum channel running through the bearing housing 9 and the retaining bracket 19 50. Two glass plates, one of which is provided with a groove, can be glued together to obtain the vacuum channel 55 in the glass vacuum plate 17. At the interface between the ring part 49 and the bearing housing 9, one of the two can face one another Surfaces run an annular groove 57 so that the vacuum is maintained during rotation Uprightness of the vacuum 57 sealing elements 65 and 66 are provided above and below the annular groove.

The vacuum channel 50 is connected to a vacuum pump in a known manner. An upper centering pin 40 extends from above through the bracket 19, the bearing housing 9, the ring member 39 and the central recess 60 in the upper vacuum plate 17 through into the space between the two DVD half sides 23 and 24. By means of a clamping nut 6, the vertical position of the centering pin 40 can be adjusted. A guide tube 41 is guided obliquely through corresponding openings in the bracket 19 and the bearing housing 9, immersed in the lower region of the centering pin 40 in this and is transferred within the centering pin 40 into a horizontal position, so that the end piece 59 of the guide tube 41 parallel to the DVD half pages 23, 24 runs. In this area the centering pin is included provided a detachable part, which corresponds to a longitudinal half and forms a solid cylinder with the other longitudinal half in this area, each longitudinal half having a groove, so that when the longitudinal halves are joined together, a curved bore is formed in which the guide tube 41 lies. A bushing 43 is provided at the outlet opening in the centering pin 40 and fixes the end of the guide tube 41 in its position. Inside the guide tube 41 there is an elastic plastic needle 42 as a metering needle 7. By means of an air cylinder 45 attached to the bearing housing 9, the elastic metering needle 7 can be moved out of the guide tube 41 by a predeterminable distance into the space between the DVD half sides 23 and 24 apply the adhesive 36 (see detailed view in FIG. 12).

The method for gluing the DVD half-sides 23 and 24 corresponds essentially to that described above for FIG. 1 with reference to FIGS. 2-7. The only difference from the above variant is that the dosing needle 7 is not swiveled into the glue application station and rotated back into the rest position, but is pushed out of the guide tube 41 into the glue application position and is fully retracted into the guide tube 41 after the glue application has ended (rest position) .

13 and 14 schematically show further variants of the central bonding according to the invention. The DVD half pages 23 and 24 are kept in a known manner by vacuum on two shaping plates at the desired distance. In FIG. 13, the lower half of the DVD 24 is kept flat, while the upper half of the DVD 23 is aligned obliquely, so that an outwardly tapering gap 69 results. An L-shaped metering needle 7 moves over the central recess of the DVD, is moved down into the wedge-shaped gap and moves outwards from the center between the DVD half-sides 23, 24. In this case, it is necessary that the bent part of the dispensing needle is smaller than the diameter of the recess . The metering needle can - according to FIG. 1 - be guided in a recess in the upper centering bolt. The dispensing needle doses the required amount of adhesive in the form of an adhesive strand while simultaneously rotating the DVD into the wedge-shaped gap 69. Alternatively, the dispensing needle can also rotate and the DVD stops. The wedge-shaped formation of the gap causes simultaneous wetting of both sides of the DVD with adhesive. By further turning the DVD, preferably at a slightly increased speed, the adhesive in the wedge is pressed outwards due to the centrifugal force and into a symmetrical shape. By adjusting the wedge angle as a function of the speed of the DVD, it is achieved that the adhesive cannot be thrown off despite turning the DVD, since the dynamic pressure is greater than the centrifugal adhesive force and a symmetrical bubble-free adhesive ring can thus form in the wedge. It is advantageous to let the wedge converge in the area of the adhesive application, as shown in Fig. 14, so that the DVD half-sides almost touch near the end of the dispensing needle, so that no or only slight capillary forces occur peel off the adhesive when applying. The wedge shape also has the advantage that there is an excess of glue on the inside and only a small amount of residual air has to be pushed out in front of the glue flow front when ejecting through the narrower gap. By adjusting the wedge-shaped gap width, the optimal adhesive outer diameter can be set before spinning off. The spinning process begins with the application of glue and can be carried out without interruption to the end, which reduces the cycle time of an adhesive process overall. This also helps that the metering needle can be returned to the rest position at an early stage. At the same time increasing the speed and releasing the vacuum, the adhesive is evenly distributed from the inside to the outside (spinning off), with an excess of adhesive being thrown outwards beyond the edge area. By means of suitable vacuum plates, the gap can be brought into a wide variety of shapes in the various phases of the adhesive process (adhesive application, symmetrical adhesive distribution, spinning off), so that the gap can be adjusted to an optimum in accordance with the viscosity of the adhesive. Already when spinning, the dishing (flatness of the upper plate) is measured by means of laser optics and the spinning process is ended when an optimal straightness (flatness) is reached. The finished DVD is then traded to the UV station and cured from one or both sides using UV light. Hardening from both sides is advantageous in that the aim is to heat the DVD as uniformly as possible. Then both sides are cooled symmetrically in the cooling station. In a final step, a laser scanner, the finished DVD ^checks' s for errors before they are deposited onto a Gutteilespindel.

15 shows various outlet openings of the metering needle 7 in cross section, namely oval (a), rounded with constrictions on the left and right (b) and angular with constrictions on the left and right (c). It is at the discretion of the person skilled in the art to propose other geometries. The most suitable form depends on various factors, such as the viscosity of the adhesive and the settings when applying the adhesive, and can be selected accordingly by a person skilled in the art. The end of the dispensing needle can have different lengths over the circumference in the area of the adhesive outlet. 16 shows an embodiment in which the lateral regions of the metering needle stand forward (a), while the top and bottom of the metering needle are cut backward (b). Therefore, the adhesive emerges there first and wets the half sides of the DVD at the same time. Overall, a better adhesive application is achieved with the present invention. The small amount of residual air between the half sides of the DVD is pushed in front by the comparatively symmetrical adhesive starting form, without the adhesive leading on one side and including air bubbles, because the symmetrical adhesive starting form results in a uniform flow front speed. At the same time, this has the advantage that, with precise dosing, only the required amount of adhesive has to be applied, which ultimately results in a shortening of the centrifuging time and finally of the cycle time.

In the following, an overview of essential technical data is to be given without restricting the inventive concept:

Application speed 6000 ° / min to 36000 ° / min

First acceleration with approx. 10000 ° / sec

Spin speed during pressing up to approx. 200000 ° / min

Second acceleration with approx. 10000 ° / sec

Spin speed for uniform adhesive thickness up to approx. 900000 ° / min

Deceleration to speed 0 with approx. 10000 ° / sec

Speed max 1.44 mill ° / min

Acceleration / deceleration max 30000 ° / sec

The process runs without interrupting the plate speed. With the start of glue application, the plate speed can be adjusted to the process according to the glue viscosity over 10 speeds.

Dosing time 1-2 sec

Dosage amount 600 ^ ιltr

Pressing time l-2sec

Spin speed 5-15 sec

Reference list

1 clamping screw

2 clamping nut

3 cutting ring

4 rotary cylinders (rotary loader)

5 centering bolts at the top

6 clamping nut

7 dispensing needle

8 dosing line

9 bearing housing

10 bearing block

11 bearings

12 spring washer outside

13 spring washer inside

14 drive pins

15 spring

16 spring cage

17 vacuum plate on top

18 stoppers

19 retaining bracket

20 spindle housing

21 spindle

22 spindle drive

23 DVD half-page top

24 DVD half-page below

25 vacuum plates below

26 centering pin housing

27 centering pin

28 spring Guide pin spring washer Drive shaft for plate drive Plate drive Base plate Adhesive catch ring, central recess in the lower vacuum plate Adhesive, glue line UV lamp Adhesive catch plate, centering pin Guide tube Flexible metering needle Needle guide bush Adapter Air cylinder for metering needle stroke Air cylinder holder Magnetic recesses Ring part Vacuum channel Adhesive suction channel Vacuum groove inside Vacuum outlet outside and outside of the air block of the vacuum channel 55 in the bearing block 10 annular groove web parallel end piece of the guide tube 41 Central recess in the upper vacuum plate, axially parallel groove or recess in the centering pin 5 U-shaped recess at the lower end of the centering pin 5 End piece of the metering needle Connection for vacuum pump, 66 sealing elements Vacuum channel in the lower vacuum plate and centering pin housing Vacuum channel in the ring part 49 wedge-shaped gap

Claims

Method and device for gluing two DVD (Digital Versati le Disc) - half-sided patent claims

1. A method for gluing substantially rotationally symmetrical plates, in particular based on polycarbonate, which have a central recess, characterized in that the adhesive is introduced via the central recess between the plates which are kept at a distance and is distributed on them by rotation of the plates.

2 method for gluing two DVD half-sides, the half-sides being kept at a distance such that a gap is formed between them, the adhesive being introduced into the gap and distributed over the two half-sides, characterized in that the adhesive over the centric recess of the DVD is introduced.

3. The method according to claim 2, characterized in that the adhesive is distributed by spinning and / or compressing the DVD half-sides.

4. The method according to any one of claims 1 to 3, characterized in that the adhesive is supplied by means of a metering needle.

5. The method according to claim 4, characterized in that the metering needle is rigid and bent at its end by 90 ° and that the length of the angled part is smaller than the diameter of the recess.

6. The method according to claim 5, characterized in that the angled end of the dispensing needle is pivoted by rotation about the axis of the dispensing needle from a rest position in the central recess of the DVD into an adhesive application position between the half-sides of the DVD.

7. The method according to claim 6, characterized in that the angled end of the metering needle is pivoted by an angle less than or equal to 180 °.

8. The method according to any one of claims 4 to 7, characterized in that the two half sides rest when the adhesive is applied and the metering needle rotates.

9. The method according to any one of claims 4 to 7, characterized in that the two half sides rotate when applying the adhesive, the metering needle also rotating or at rest.

10. The method according to claim 4, characterized in that the metering needle is flexible and is slidably mounted in a guide bush positioned in the central recess.

11. The method according to claim 10, characterized in that the metering needle for the adhesive application is pushed out a predeterminable distance from the guide bushing and is withdrawn completely into the guide bushing immediately after completion of the adhesive application.

11a. Method according to one of claims 4 to 11, characterized in that the two sides of the DVD from the beginning of the Rotate the adhesive application continuously until the end of the adhesive distribution and that after the adhesive application the speed is increased up to the desired spin speed.

12. The method according to any one of claims 1 to 12, characterized in that the gap is wedge-shaped in the region of the central recess, the wedge tapering in the radial direction and that the wedge is preferably adjusted such that after the adhesive application and before Spin off at a given speed, the back pressure of the gap is greater than the centrifugal force of the adhesive, so that the adhesive is distributed evenly and symmetrically in the wedge before being spun off.

13. The method according to any one of claims 2 to 12, characterized in that the two half sides are wetted simultaneously when applying the adhesive, for example through a suitable outlet opening of the dispensing needle.

14. The method according to any one of claims 2 to 13, characterized in that when applying the adhesive and / or distributing the adhesive and / or spinning the adhesive, the gap has a parallel or wedge-shaped or other predetermined geometric shape.

15. Device for introducing a fluid between two spaced and provided with central recesses plates, in particular for carrying out a method according to one of claims 1 to 14, with means for holding and moving the plates to each other, with means for centering the plates and with at least one fluid supply line, thereby characterized in that the fluid supply lines is / are guided from the outside through one of the central recesses and ends / ends in the space between the spacing plates.

16. The apparatus according to claim 15, characterized in that the disks are DVD half-sides and that the fluid is an adhesive.

17. The apparatus according to claim 15 or 16, characterized in that an upper and a lower centering pin are provided for centering, which are movable through the central recesses.

18. The apparatus according to claim 17, characterized in that the upper centering pin is provided in its surface with one or more, axially parallel, recesses, that the fluid supply lines are formed in the region of the centering pin as an L-shaped metering needle, preferably as steel needles, that the each vertical section of the metering needles runs in one of the axially parallel recesses and that the end piece, which is in each case bent by 90 °, lies in a radial recess in the lower end region of the centering bolt, which preferably has a U-shaped cross section.

19. The apparatus according to claim 18, characterized in that means for rotating the metering needles about their vertical axis and means for a vertical change in position of the metering needles are provided.

20. The apparatus according to claim 18, characterized in that the lower end of the upper centering pin, which is below the end pieces of the metering needles are plate-shaped that a channel for suctioning off excess adhesive (adhesive suction channel) begins in this area, that this adhesive suction channel runs in the upper centering bolt and is connected to a suction device.

21. Device according to one of claims 15 to 20, characterized in that the holding means are designed as a vacuum plate.

22. The apparatus according to claim 21, characterized in that the vacuum channel of the upper vacuum plate is connected via an annular groove on the upper centering pin with a vacuum channel in the upper centering pin and that the vacuum channel of the upper centering pin is connected to a vacuum pump.

23. The device according to claim 17, characterized in that the fluid supply line is designed as a flexible metering needle, that the flexible metering needle is guided in a guide tube, that the guide tube obliquely, preferably at an angle as flat as possible, immersed in the central recess and through the lower The area of the upper centering pin extends, the guide tube merging into a horizontal position within the lower centering pin and not protruding from the centering pin at the point of exit, and in that means are provided for displacing the flexible metering needle in the guide tube, for example an air cylinder.

24. The device according to claim 23, characterized in that vacuum plates are provided as holding means.

25. The device according to any one of claims 15 to 24, characterized in that the holding means are equipped at their edge region with a system of resiliently mounted driving pins and driving grooves and that a rotatory shear drive is provided for at least one of the holding means, at least that with the Driving grooves equipped holding means rotatori must be driven.

26. Device according to one of claims 15 to 25, characterized in that a spindle drive is provided for moving the plates.