DE19940808A1 - Removal of a surface layer from a substrate layer on an information-carrying disc by machining involves applying pressure to the upper side of discs moving on a conveyer belt - Google Patents

Abstract

Discs pass one after another on a conveyer belt (18) to a machining station (30) with cutting tools (128). Discs are supported on the underside as they pass through a pressure application area (93) of the station. Pressure is applied to the upper side without significant increase in friction to press discs against the conveyer during the machining operation. The machining tools rotate about axes perpendicular to the to the discs. An Independent claim is made for the process equipment which includes a machining station (30) with tools (128), a conveyer (18) moving discs to the station and a pressure application area (93) on the upper side for pressing discs onto the conveyer.

Description

The invention relates to a method for machining a Surface layer of an information carrier disc from its substrate disc, with information carrier discs one after the other station supplied with at least one driven stock removal tool and the substrate disks obtained by machining from the machining station can be transported by a plurality of successive Information carrier discs on a transport carrier through the guy passed through and during the passage through the Machining station on its side far from the carrier.

Information carrier discs, e.g. B. CD discs are made of substrate discs made of high quality plastic materials, which on one of their Surfaces with a, especially metallic, information Sensing layer and a protective lacquer layer are provided. Around the high quality plastic materials of the substrate discs from Rejects or information carrier discs that are no longer required to recover with a high degree of purity, it is necessary to recover the brought lacquer and information scanning layer from the substrate wafer separated by a suitable method.

Such a method is known from DE 43 40 595 A1 known. In this process, information carrier disks are used with their uncoated surface via an addition device in each case circular indentations arranged in a turntable. To Insert an information carrier disc into a corresponding circular one The turntable is rotated until the next circular  Well with an information carrier disc about the addition device can be equipped. In a removal station is in front given a distance from the turntable, a cutting tool, which is essentially coaxial with an underlying one circular recess is arranged. The stock removal tool is in shape of a milling cutter for removing a surface layer of the each of the information carriers located below it. To hold and in particular locking the information carrier disks in the circular recesses during the removal process are also Suction cups provided. After the removal process, the through Removal of substrate slices obtained by an ejection mechanism lifted off the turntable and, if necessary, further processing steps fed.

In the process according to this prior art, the informa tion carrier disks in predetermined positions on the turntable, namely in the circular depressions, to be positioned around one secure hold - by positive locking in the recesses and by force closure by means of the suction cups - to ensure during machining. The positioning and this type of "holder" of the to be processed Information carrier disks, however, have considerable equipment technology Effort connected and at least with regard to the rotation lock unsure. Problems also arise in the removal of bowl-like shaped, wavy or non-round reject information carrier disks, since these do not guarantee a secure hold with the suction cups.

42 05 390 A 1 is a comparable process for cutting end removal of a surface layer of an information carrier disc known. In this process, a blade is used instead of a milling head used, which is a surface layer of the to be processed Removing information carrier disk by machining. This one too  The information carrier disks on the turntable must be moved in predetermined positions are positioned.

A method of the type described in the introduction is also known from US Pat. No. 5,203,067 known. The plates are stationary along one Promotion table promoted by pairs of roles, each of which has a role in the level of the conveyor table and another role above the conveyor table is arranged. The rollers can be rubberized. Between each other following roller pairs is a milling cutter with a spiral milling edge arranged, its axis transverse to the conveying direction runs and its outer surface on the surface to be machined Information carrier disc rests. Through the milling cutter are on the respective information carrier forces in the conveying direction and transverse to Direction of conveyance exercised, which is not reliable due to the pairs of rollers can be accommodated so that rotational directions superimposed on the conveying direction and transverse movements of the information carrier disc are not excluded can be.

The invention has for its object a method of the beginning the type described so that the information carrier discs as clear as possible during the machining process, through which Cutting only minimal or unaffected movement by the Execute a removal station.

To solve this problem, the invention proposes that the Information carrier discs on a moving and supported on the back Conveyor belt is guided through the machining station lying on top be, with on the far side of the conveyor belt Information carrier discs a stationary pressure field is applied with low friction, by means of which the respective information carrier disc engages with the conveyor belt is pressed, and that the removal on the  side of the information carrier disk far from the carrier tape by a A plurality of chipping tools takes place, which in order to the pressure field in rotate essential orthogonal axes of rotation.

In the method according to the invention, can be easily optimized Positioning the plurality of chipping tools to the pressure field taking into account the diameter of the information carrier disks ensure that there is a sufficient Pressing the disks onto the conveyor belt takes place through Stiction on the conveyor belt to take the Ensure information carrier discs and twists the Avoid information carrier discs on the conveyor belt.

In particular, it is excluded that during the passage through the removal station enters a situation where only one Cutting tool interacts with the area presented, one Situation as it is in DE 43 40 595 A1 and there by Intake forces only with great effort and even then not reliable can be mastered. The majority of stock removal tools it is possible to have a partial area between adjacent stock removal tools of the pressure field so that it is close to the respective Cutting point is avoided by pressing forces slip.

Furthermore, according to the invention, rejects Information carrier disks, which are for example wavy or bowl-like are formed, ensuring a secure hold during the Machining can be processed. Moreover, this is the invention Procedure of the dimensioning and shape of the contour Information carrier disks independently, d. H. it can Information carrier discs of different sizes (CD and mini disc) and Contour are machined equally.  

In this context it can be provided that the Cutting tools at least partially within the pressure field on the Attack the information carrier disc. By arranging the Cutting tools at least partially inside the pressure field is like above carried out a sufficient pressure effect by the Pressure field guaranteed and a slip of the information carrier disc excluded on the moving conveyor belt.

The arrangement of the stock removal tools at least partially within the Pressure field can be realized in particular that the Cutting tools within the surrounding openings of the Press field on the information carrier discs. This Measure ensures a pressure effect directly through the Perforations surrounding areas of the pressure field, so that the Determine the cutting forces on the information carrier disks act, namely in the area of stock removal tools, adjacent to the Pressure field a slip-preventing pressure effect on the respective Information carrier disc is exercised. Dodging the Information carrier disc to be machined during machining due to the cutting forces introduced, this also applies prevented.

The openings can be circular and the maximum Enclose the circulating circuit of the stock removal tools with a narrow annular gap. By this measure allows the pressure field to be formed over a large area and thus a large-area pressure effect can be achieved, which in the Removal of a secure grip between the carrier and Information carrier disc guaranteed.

One for the introduction of the removal forces acting during the removal favorable geometric distribution of the stock removal tools within the Pressure field can be obtained by using the stock removal tools  in a plurality of lines arranged transversely to the tape running direction are arranged, the stock removal tools of different lines stand in gap with each other and with their maximum orbits in Overlap cross direction. This measure leads to a staggered Arrangement of the stock removal tools within the pressure field, so that on the one hand, during the stock removal process on the information carrier disc resulting resulting machining forces due to each other offset arrangement of the stock removal tools can be reduced overall can, so that the risk of a release from liability between Information carrier disc and carrier and a destruction of the Substrate disk can be minimized during the removal process. Furthermore, the staggered arrangement of the stock removal tools and due to the mutual overlap of the stock removal tools with their Maximum orbits in the transverse direction cause the at Passage of an information carrier disc through the removal station from the individual chipping tools in the information carrier disc introduced (machined) paths overlap each other. This can the entire surface of the information carrier disk to be machined be removed reliably.

The provision of a plurality of stock removal tools, which like are arranged within the pressure field, leads to a cheaper introduction of the removal forces and thus to a less mechanical stress on the information carrier disc, which also increases the risk of slipping of the information carrier disc on the Conveyor belt reduced during machining: these advantages can be supported by the fact that the individual stock removal tools the majority of cutting tools with different directions of rotation circulate. Through this measure, one of the initiated Cutting forces resulting on the information carrier disc Torque can be minimized, which in turn releases the adhesive engagement minimized between the information carrier disc and the conveyor belt.  

It can further be provided that the diameter of the maximum Orbiting circles is smaller than the diameter of the information carrier disks. This measure leads to that in the maximum orbits Machining currently carried out only ever applies to a sub-area of the Surface of the respective information carrier disc to be machined limited. This can prevent a situation from occurring are, as occurs for example in DE 43 40 595 A1, at which is a single chipping tool on the entire surface of the Information carrier disc attacks and thus a high torque exercises this. In this context, the invention can provide be that the ratio of the diameter of the maximum orbits of the Cutting tools for the diameter of the information carrier discs approx. 0.2 to 0.5, preferably about 0.3 to 0.4. A cheap one Pressing action and a secure grip intervention results according to the invention by such a coordination of the dimensions of the pressure field and the distribution of the stock removal tools over the pressure field in relation to the Diameter of the information carrier disks to be processed, that in each Phase a removal over the respective information carrier disc at least a quarter, preferably at least a third, most preferably at least half of that in the direction of transport considered diameter is covered. So by this vote ensures that the respective information carrier disc always with a sufficient area to ensure a secure hold the pressure field is pressed onto the conveyor belt.

To the adhesive engagement between the moving carrier and the not to interfere with this information carrier disc, can be provided that the pressure field rolling or sliding on the side of the information carrier disks away from the carrier. Here it can be advantageous to design the pressure field such that in Connection to the side of the information carrier remote from the carrier disc creates a frictional force that is essential  is less than the frictional force between the transport carrier and that on the Transport carrier adjacent side of the information carrier discs. On such a difference in amount between the frictional forces on the Both sides of the information carrier discs can be used by suitable Choice of materials in contact with the information carrier disc treading surfaces of the pressure field and transport carrier become. This point will be discussed in more detail later.

Furthermore, or additionally, the pressure field can be rotated from one field Bearing balls or rollers formed, which also leads to a low-friction system between the pressure field and the information carrier leads.

A rotating tool can be used as a stock removal tool with an envelope surface which is essentially orthogonal to the pressing direction of machining elements with machining lying in the envelope surface edges or tips. It can be provided that the chip removal has approximately radially extending cutting edges in the envelope surface. Such a design of the stock removal tool enables the entire surface to be machined during a defined material removal the stock removal process.

The thickness of the removed with the at least one cutting tool Surface layer is the same in the method described above the protrusion of the at least one stock removal tool compared to the Pressure means in the direction of pressure. The thickness of the machined layer To be able to choose freely, it can be provided that the at least one Ab Cutting tool adjustable in the pressing direction in relation to the pressing field is.

This can be achieved by adjusting the chip removal Compared to the pressure field, an adjustment drive is provided, which  on the one hand on the pressure field or on one with it connected part and on the other hand on the chipping tool acts.

In order to be independent of the thickness of the respective information carrier disc constant pressure between the pressure field, Information carrier disc and carrier and thus one consistently safe adhesive intervention between the information carrier disc and To ensure transport carriers, the pressure field can be used with one of its distance from the carrier essentially un dependent biasing force against the transport carrier.

This can be achieved particularly easily by the pretensioning force derived from gravity on the components forming the pressure field is.

Additionally or alternatively, it can be provided that the Transport carrier with one of its distance from the pressure field essentially independent preload against the pressure field is biased. To compensate for differences in thickness successive information carrier disks can also be provided be that the transport carrier is height-adjustable in sections.

Compensating for the different material thickness from on the Transport carriers lying one after the other Information carrier disks has the consequence that of the substrate disks only one surface layer each with a certain, constant permanent layer thickness - namely equal to the excess of the minimum a machining tool over the pressure field - is machined, namely regardless of the thickness of the individual information carrier disc. At thicker information carrier disks give way or give way Transport carrier or the pressure field by a certain distance in vertical direction, whereas with thinner information carriers  the pressure field and the transport carrier due to the Preload move relative to each other, so in both cases the information carrier to be cut comes into contact with both and opens the carrier is pressed. It should be noted that the mutually facing surfaces of the conveyor belt and Pressure field only up to an adjustable minimum distance to each other can move which minimum distance is smaller than the smallest possible Information disc thickness and greater than the maximum overhang of the stock removal tool over the pressure field.

For rear support of the conveyor belt in the area of Pressure field can be provided that the conveyor belt with the side far from the press field glides over a support table which supports the Press the transport carrier against the pressure field. The Sectional height adjustment achieved by the support table at least in the transport direction in a plurality of table segments is divided and that the table segments are essentially independent from each other while overcoming the respective preload in can deviate substantially in the direction orthogonal to the pressure field.

The biasing force can each be at least one of the spring forces Lift mechanism be derived. A simple design and reliable Function arises, for example, when each table segment at least one, preferably two, force accumulator is or are assigned. This enables the preload force to be set separately for each table segment can be set. As an energy store can be in favor of a simple and cost-effective construction each an elastic rubber body, a Compression spring, or a pneumatic spring element can be used. The Use of a pneumatic spring element offers in particular with regard to its wear properties and service life as well as its linear spring characteristics advantages.  

You get a simple design of the pressure field if that Pressure field on one with a passage for the at least one Ab pressure plate provided with cutting tool with a pressure surface is formed and that also a bearing plate for a Cutting tool associated tool drive spindle and die Tool drive spindle driving tool drive is provided.

With such a design of the pressure field, the above can also be already mentioned adjustment of the stock removal tool compared to the Simply implement the pressure field, for example by the fact that the tool Drive spindle and / or its spindle bearing opposite the bearing plate in Pressing direction is adjustable. A screw drive can be provided for this be, for example, on the one hand on the spindle bearing and on the other attacks the bearing plate. The screw drive can have at least one Have a spindle with a threaded spindle axis parallel to the pressing direction.

When the information carrier disk is removed, there is a strong one Chip formation, the resulting chip depending on material and feed, d. H. Transport speed of the carrier, particulate (dust like) or connected (wool-like) condition. In order for the chips to adhere to the substrate wafers and on the Carrier a pollution of the environment of the removal station and to prevent chips from interfering with their operation, can also be provided that the at least one chipping tool a chip extraction is assigned. It can be provided in detail be that the chip extraction one on the chipping tool Passing suction channel, which if desired between the pressure plate and the bearing plate is included. Furthermore, the Chip extraction one from the respective cutting point to the Have suction channel leading connection channel. It can be provided be that the connection channel through the annular gap between the  Cutting tool and the edge of a receiving tool Breakthrough of the pressure field is formed.

With such a design, the chips are suctioned off Chip suction an air flow is passed through the suction channel, which in the respective communicating with the suction channel Connection channel creates a suction effect, so that at the cutting edges generated chips due to the suction through the gap between the Cutting tool and the edge of those provided in the pressure field Opening can be sucked into the suction channel.

The chip extraction has the further advantage that it is used as a cooling in the Area of material removal affects what the life of the respective cutting tool and on the other hand destruction prevented by thermally sensitive substrate disc material.

The substrate wafers can be made of a plastic, in particular a thermoplastic, such as polycarbonate, exist.

To ensure sufficient adhesion between the information carrier disc and to ensure conveyor belt, the conveyor belt at least from its surface made of a material such as be made of PVC, which in connection with each adjacent surface of the information carrier an adhesive Material pairing results. Has a conveyor belt made of PVC the further advantage that this to a certain extent in the range of Material surveys, such as stacking beads or the like can yield to the information carrier discs and thus a uniform material removal is guaranteed.

In contrast, as already indicated above, it is necessary that between the mutually contacting surfaces of  Information carrier disc and stationary pressure field only slight Frictional forces act. This can be achieved by the fact that Pressure field at least on its surface made of a material such as For example, made of PTFE, which in connection with the each adjacent surface of the information carrier a slippery Material pairing results.

Although it is basically not necessary, the information carrier slices on the transport carrier in predetermined positions, such as for example in depressions to form a positive connection or the like, to bring, should not be excluded that the information carrier slices by stationary or / and attached to the transport carrier Positioning means in transverse to the transport direction and / or along the Transport direction are brought orderly. For example in this context, positioning rails are provided, which the Information carrier discs before they pass through the removal station position relative to the stock removal tools, so that cheap geometrical relationships for the introduction of the cutting forces result.

Knobs or cross ribs on the conveyor belt can also Support positioning effect, for example cross ribs, their Distance in the direction of transport is slightly larger than the largest occurring Information disc diameter.

Good results with regard to the quality of the machining and the Throughput of information carrier disks can then, for example achieve when the carrier carries the information carrier discs with a Speed in the range of 15-25 m / min., Preferably about 20 m / min., Moved.

With regard to the further processing of the machined substrate wafers be provided that the substrate wafers after the removal of a  Shredding station are fed. In this shredding station then, for example, a painting material from the raw material of the substrate wafers manufactured, which are then recycled to produce new products can.

Before recycling the machined substrate wafers, Ge ensuring a high purity of the recovered raw material Substrate disks are provided that the machined substrate disks after passing through the removal station of a quality inspection subject in particular to the quality of the removal and Discarded and insufficient quality substrate wafers if necessary, be subjected to renewed machining. The Quality inspection on an optical observation of remnants of the Surface layer based on quantity and / or distribution. This optical observation can be done with the help of a camera or other optical fluoroscopy performed with the appropriate receiver become. Should occasionally substrate slices in the quality inspection incurred, which are only insufficiently removed from the Surface layer of paint and / or metal have been freed, so can these are either completely discarded or again at the removal station be fed. Furthermore, the quality inspection can also be determined whether the removal station is a sufficiently thick upper ablates surface layer, or whether the stock removal tools possibly against the Pressure field must be adjusted in the direction of pressure. Let also defects in individuals based on the results of the quality inspection Determine stock removal tools.

The invention further relates to a device for machining a surface layer of a laminate from its substrate layer, in particular for carrying out the method described above, comprising a removal station with at least one driven removal tool, the device further comprising:

• - A transport carrier, which is designed to a plurality successive laminate through the removal station to Machining of the laminate on its side far from the carrier to pass through the removal station during the passage and
• - One that acts on the side of the laminate far from the carrier Pressure field, by means of which the laminate on the Transport carrier during the passage through the removal station at least partially in engagement with the moving carrier are pressed.

This device can be according to the invention by the preceding described device features.

The following are exemplary embodiments of the present invention described with reference to the accompanying figures. They represent:

Figure 1 is an overview of an apparatus for performing the method according to the invention in a side view.

FIG. 2 shows a top view of the device according to FIG. 1;

Fig. 3 is a partial sectional view of a machining station along line III-III of Fig. 4;

Fig. 4 is a partial sectional view of the machining station along line IV-IV of Fig. 3;

Fig. 5 is a view of a tool spindle drive including spindle bearing in cross section;

Fig. 6 is a side view of a Abspanwerkzeugs;

FIG. 7 shows a bottom view of the stock removal tool according to FIG. 6;

Fig. 8 is a schematic side view of a quality testing station, partly in section;

Fig. 9 is a plan view of a pressure plate; and

Fig. 10 is a left side view of the platen of FIG. 9 partially in section.

The schematic side view according to FIG. 1 and the schematic top view according to FIG. 2 show a device according to the invention, which is generally designated 10 . The device comprises a base frame 12 with vertical support legs 14 and a horizontal alignment rail 16 to which the support legs 14 are attached. The support legs 14 on the left in the illustration support an endless conveyor belt 18 which is deflected via deflection rollers 20 , 22 and rotates in the direction of arrow A. The conveyor belt 18 is driven by the motor 24 . In the area of the revolving conveyor belt 18 on the left in FIG. 1, an addition station 26 is arranged above the conveyor belt (only shown schematically), which has a magazine with information carrier disks, in this case CD disks. The addition station 26 successively places a CD 28 on the conveyor belt 18 , as shown schematically in FIG. 1. Between the deflection rollers 20 , 22 there is a removal station 30 above the conveyor belt. This includes a drive motor 32 , the drive belt 34 drives individual spindles 36 rotatably mounted in the machining station 30 via a drive belt. As can be seen in FIG. 2, the drive belt 34 is wound around the tool drive spindles 36 in order to achieve an optimal drive effect.

A rotating chipping tool (not shown in FIGS . 1 and 2) in the form of an end mill is arranged on the tool drive spindles 36 , as will be explained in detail below, in order to remove a surface layer from the CD 28 .

As can also be seen in FIGS. 1 and 2, positioning strips 38 are provided in the area of the conveyor belt in front of the grafting station 30 in a stationary manner relative to the base frame 12 , which conically align the CDs 28 placed on the conveyor belt 18 via the addition station 26 due to their transport direction A. position another tapering arrangement in a central region B of the conveyor belt 18 . This positioning is coordinated with the arrangement of the tool drive spindle 36 and thus with the arrangement of the stock removal tools.

At the right end of the conveyor belt 18 in FIG. 1 there is a quality inspection station 40 which examines the CD substrate disks 28 'machined in the machining station 30 with regard to the quality of the machining carried out. The quality inspection station 40 comprises a stripper plate 42 , which stripes CD substrate disks lying on the conveyor belt 18 in the region of the deflection roller 22 from the conveyor belt 18 . Furthermore, the quality inspection station 40 comprises a guide bar 44 which has an inclined surface inclined to the stripper plate 42 as guide surface 46 . In its actual examination area, the quality inspection station 40 comprises an optical unit 48 and a guide plate 50 which is inclined downwards towards the essentially horizontal conveyor belt 18 and on which the CD substrate disks 28 'lifted from the conveyor belt 18 by the stripper plate 42 slide downward due to their slope downforce . The guide plate 50 is transparent at least in the area below the optical unit 48 . A light source 52 is arranged beneath the guide plate 50 and illuminates the CD substrate disk 28 ′ sliding over it on the guide plate 50 .

At the right end of the device 10 according to the invention in FIG. 1, a switch 54 is provided which, depending on the result recorded in the quality inspection station 40 with regard to the stock removal quality of the CD substrate disks 28 ′ examined in each case, those CD substrate disks 28 ″ which predefined ones Fulfill quality requirements, on a first track 56 and those CD substrate disks 28 '''which do not meet the specified quality requirements, on a second track 58 . The machined CD substrate disks 28 ″ of high quality (high degree of purity) derived from the track 56 can be fed for further processing, whereas the CD substrate disks 28 ″ of low stock quality derived from the second track 58 can be fed to the addition station 26 again or be completely sorted out. In Fig. 1 and 2, 60 can be seen further comprises a control unit via which the apparatus 10 according to the invention is controllable. However, it should be noted that the device according to the invention can also be controllable and monitorable via a computer unit (not shown).

The structure of the removal station 30 will now be explained in detail with reference to FIGS . 3 and 4. The favor of a simple illustration, only partially indicated in Fig. 3 conveyor belt 18 runs in direction A first Trans port in an inlet region 62 of the Abspanstation 30th In this inlet area 62 , the conveyor belt 18 runs within lateral guides 64 on a table 66 , which supports it from below. At the end of the inlet area 62 , a pressure roller 68 is provided, which is movably guided in the horizontal direction via a suspension 70 . In particular, as shown in Fig. 4, the pressure roller 68 is rotatably mounted on a bearing axis 72 so that it can roll on the belt moving in the transport direction A. The bearing axis 72 is in turn supported on telescopic arms 74 , 76 . These telescopic arms are guided telescopically in the suspension 70, with a stop plate 78 the stroke of the telescopic arms 74, 76 and thus the movement range of the platen roller 68 in the horizontal direction by mutual abutment with corresponding stop surfaces defined within the suspension 70th At the pressure roller 68 in the transport direction A, the cutting area of the removal station 30 follows. In this removal area, the conveyor belt 18 is guided laterally by side guides 79 and on the other hand slides over individual table segments 80 a, 80 b, 80 c, which support the conveyor belt 18 from below. The table segments 80 a, 80 b, 80 c are movably mounted on a housing base plate 82 in the horizontal direction. The guides 79 project beyond the lateral edges of the table segments 80 a, 80 b, 80 c and thus limit a movement of the table segments 80 a, 80 b, 80 c in the horizontal direction upwards.

Locking nuts 84 are screwed onto threaded bolts 86 a, 86 b, 86 c fixed to the table segments 80 a, b, c. Washers 88 are arranged on the threaded bolts 86 a, b, c on the side of the base plate 82 opposite the lock nuts 84 . Between the washers 88 and the side of the table segments 80 a, 80 b, 80 c facing away from the conveyor belt 18 , spring bodies 90 a, 90 b, 90 c are provided, which move the table segments 80 a in the vertical direction downward according to arrow C, Counteract 80 b, 80 c springy. The spring body 90 a, 90 b, 90 c are in the case shown with a through hole for the threaded bolts 86 a, 86 b, 86 c formed substantially spherical rubber body, the spring action of which is due to the rubber elasticity of its base material. However, it is also conceivable to use spiral springs or disc spring blocks or similar resilient arrangements or elements instead of the rubber body by 90 a, 90 b, 90 c.

Above the conveyor belt 18 guided over the table segments 80 a, 80 b, 80 c, a pressure plate 92 is provided which, together with the pressure roller 68, defines a pressure field 93 . The pressure plate 92 is connected through vertical plates 94 (see Fig. 9 and 10) connected to a bearing plate 96. The unit formed from pressure plate 92 , vertical plates 94 and bearing plate 96 is fastened in a housing 98 and is therefore immovable and stationary with respect to the conveyor belt 18 .

Spindle bearings 100 are accommodated in the bearing plate 96 for the tool drive spindles 36 , each of which has already been mentioned above and which can be rotated about the axes of rotation R. The spindle bearings 100 are of circular cylindrical design and have thread-like notches 104 on their cylindrical outer surface. Threads 106 from set screws 108 designed as threaded spindles engage in the thread-like notches 104 . Two setscrews 108 are provided for each spindle bearing 100 . The spindle bearings 100 are guided in the vertical direction via their outer surfaces in a guide bushing 110 inserted into the bearing plate 96 in accordance with arrow E. By uniformly adjusting the two adjusting screws 108 acting on the spindle bearing 100 , the spindle bearing 100 can be adjusted in the vertical direction relative to the bearing plate 96 in accordance with arrow E. By rotating the two adjusting screws 108 engaging on one and the same spindle bearing 100, the respective spindle bearing 100 can then be fixed within the guide bushing 110 by tilting it.

Specifically, the spindle bearing 100 is constructed as shown in FIG. 5. The tool drive spindle 36 comprises at its end which is in engagement with the drive belt 34 a drive roller 112 which engages via a conical through bore 114 with a corresponding conicity 116 at the end of the tool drive spindle 36 and via a tension screw 118 with the tool Drive spindle 36 is clamped. The tool drive spindle 36 is rotatably supported in the spindle bearing 100 , which has a bush-like housing 120 , via roller bearings 122 , 124 , which roller bearings (radial bearings) 122 , 124 are secured in a known bearing arrangement essentially free of play within the bearing bush-like housing 120 . At its end remote from the drive roller, the bearing spindle 36 has a receptacle 126 for a machining tool 128 (indicated only schematically in FIG. 3 by dashed lines).

Corresponding to the arrangement of the spindle bearings 100 within the bearing plate 96 (see FIG. 2), openings 130 are provided in the pressure plate 92 , as shown in FIGS. 9 and 10. The openings 130 are arranged in the pressure plate 92 in detail as follows. Those openings 130 ₁ , 130 ₂ , which are first reached by a CD 28 running through the removal station 30 , lie on a line transverse to the conveying direction A at a distance a, which corresponds to half the diameter of the CD 28 , from the inlet side of the pressure plate 92 removed (see Fig. 9). This ensures that at the beginning of the removal process with the removal tool (not shown) which is passed through the openings 130 ₁ , 130 ₂ , in any case when the CD is positioned on the conveyor belt 18 , half of the surface of the CD 28 to be removed is already covered by the pressure plate 92 is. Starting from the openings 130 ₁ , 130 ₂ close to the inlet side, the openings 130 ₃ and 1304, likewise lying on a line transverse to the conveying direction A, follow in the transport direction A. The openings 130 ₁ and 130 ₂ overlap in the direction transverse to the transport direction A with the openings 130 ₃ and 130 ₄ respectively by the dimension w, so that into the CD 28 through the cutting tools, which through the respective openings 130 ₁ , 130 ₂ , 130 ₃ and 130 _{4 are} passed through, tracks are milled, which overlap each other approximately by the dimension w (minus twice the gap width 2 x). In the same way, the opening 130 _5, which is offset further from the openings 130 ₃ , 130 ₄ in the transport direction A, is arranged. This opening 130 ₅ overlaps with the openings 130 ₃ , 130 ₄ arranged in front of it in each case by the dimension u, so that the webs milled into the CD 28 by the associated machining tools also overlap by a corresponding dimension (u-2x). The opening 130 ₅ is also arranged at a distance a from the outlet side of the pressure plate 92 , in order to obtain a sufficient pressing action when the material is removed using the cutting tool guided through the opening 130 ₅ . The openings 130 ₁ , 130 ₂ are so far offset from the center of the pressure plate 92 that they in any case protrude beyond the edge of a CD 28 positioned on the conveyor belt 18 , so that due to the overlap (u, w) and the Projecting y a material removal over the entire surface of the CD 28 is guaranteed.

In the following, a distinction is no longer made between the openings 130 ₁ , 130 ₂ , 130 ₃ , 130 ₄ and 130 ₅ , and the openings 130 are generally referred to.

The openings 130 are conical and narrow in the direction of the conveyor belt 18 . The smallest diameter e of the openings 130 is dimensioned such that an annular gap with the gap width (see FIG. 6, in the range up to a few mm) between the opening edge and the maximum circumferential circle defines the envelope W (see FIG. 7) of the through the respective opening 130 through cutting tool 128 remains. If, for example, an end mill 132 as shown in FIGS . 6 and 7 is used as a cutting tool 128 , the smallest diameter e of the conical openings 130 should be chosen correspondingly larger for a diameter d of the sheathed jacket W of the end mill 132 , namely e = d + 2x.

Regarding the design of the end mill, it should be noted that it has special cutting edges 134 , which are arranged in adaptation to the direction of rotation F of the end mill 132 on the leading side of the cutting areas of the cutter 132 and are made of a wear-resistant material, such as a sintered material containing diamond dust . The face milling cutter 132 comprises cutting edges 135 on its cutting edges 134 , the envelope surface H of which defines the removed surface of a CD during the removal. For the sake of completeness, it should be noted that the face milling cutters 132 can be clamped into the corresponding receptacles 126 via a centrally arranged clamping bolt 136 .

FIG. 6 also shows that the milling cutter 132 protrudes beyond the lower surface of the pressure plate 92 , indicated by the broken line, by the dimension y. This dimension y corresponds to the thickness of the layer machined with the milling cutter 132 when a CD is being machined. The projection y of the milling cutter 132 can be set by means of the adjusting screws 108 as described above.

Returning to FIG. 3, it should also be noted that the pressure plate 92 is provided on its inlet side with a guide slope 137 and on its side facing the conveyor belt 18 is provided with a coating 138 , which in combination with that in it Contacting surface of the respective CD to be machined results in a sliding material pairing. In particular, considering the sliding properties of the CD coating (lacquers or the like), PTFE is preferred as coating 138 .

When a CD to be cut passes through the removal station 30 , it first runs on the conveyor belt 18 into the entry area 62 . When the pressure roller 68 is reached, it presses the CD onto the conveyor belt 18 , the material pairing of the raw material of the CD lying on the conveyor belt 18 and the surface of the conveyor belt 18 (preferably PVC) resulting in a strong adhesive engagement between the CD and the conveyor belt due to the pressing action. The pressure roller 68 ensures, in particular in the case of non-planar CD disks, that they slide reliably under the pressure plate 92 without being rejected at the guide slope 137 . The CD then runs in the direction of transport A in the area of the guide slope 137 under the pressure plate 92 and is by means of the spring body 94 a, 90 b, 90 c over the table segments 80 a, 80 b, 80 c prestressed in the direction of the pressure plate and over that running conveyor belt 18 pressed against the pressure plate 92 . The CD 28 will - due to promotes sliding material pairing between the CD 28 and Andrückplattenoberfläche and an adhesive favorable material pairing between the CD 28 and conveyor belt surface - in the solid adhesive engagement with the conveyor belt 18 and slides on the surface of the pressure plate 92 along. In the field of pressure plate 92, the chipping of the pressure plate 92 takes place facing surface of lying on the conveyor belt 18 CD. The depth of the removed layer corresponds to the projection y of the removal tools 128 over the underside of the pressure plate 92 , ie over the underside of the coating 138 . As the conveyor belt 18 continues to move, the CD 28 , which is in engagement with it, is guided past the individual chipping tools 128 , which are staggered in the transport direction A as described above, and webs running in the transport direction A are milled into the CD. Due to that of Fig. 2 and 9 apparent staggered arrangement of the milling cutter 128 is ensured, is that the mutually overlapping webs over the entire extent of the CD 28 in the direction transverse to the transport direction A extend so that the entire surface of the abzuspanenden CDs 28 chipped is.

With different material thickness of successive CDs 28 , the pressure roller 68 and the table segments 80 a, 80 b, 80 c dodge in the vertical direction. This ensures that regardless of the material thickness of the CD 28 to be machined in each case, only one surface layer of constant layer thickness, namely corresponding to the projection y of the stock removal tools 128 , is always machined over the underside of the pressure plate 92 .

It should also be added that an air flow can be passed between the pressure plate 92 and the bearing plate 96 , as shown by the dashed arrow LS. In the area of the openings 130 in the pressure plate 92, this air flow creates a suction effect directed away from the conveyor belt 18 , which draws in chips resulting from the cutting edges 134 during the removal through the annular gap x between the removal tool 128 and the boundary surface of the opening 130 . The sucked-in chips are then carried along in the air flow LS, which is generated by fan or suction means, not shown. Furthermore, the air flow LS still has a cooling effect for the machining tools 128 , so that the service life, in particular of the machining edges 134 , can be increased.

After passing through the removal station 30 , the conveyor belt 18 emerges from the removal station 30 through the outlet shaft 140 and takes with it, due to the adhesive engagement between the conveyor belt 18 and the CD, the respectively removed CD substrate disk. The CD substrate disk 28 'is then guided from the conveyor belt in the transport direction A, as can be seen in FIG. 1, to the quality inspection station 40 . After the CD substrate disk 28 ′ has been stripped off by the stripper plate 42 , the CD runs on the guide plate 50 arranged as an inclined plane, due to its slope, driving force below the positioning guide rail 42 , into the quality inspection device 40 .

Details of the quality inspection station 40 are explained below with reference to FIG. 8. Arranged within the optics unit 48 is a camera 142 with a lens 144 , which has a field of view 146 shown in broken lines in FIG. 8. In the area of the field of view, the guide plate 42 is formed by a transparent plate 148 , preferably made of scratch-resistant glass or plastic material. Beneath the transparent plate 148 , a light element 150 is positioned in the light source 52 , which illuminates a stripped CD substrate disk 28 'sliding on the transparent plate 148 . If the CD substrate disk 28 'is completely in the field of view 146 of the camera 142 , this is captured by the camera 142 and a snapshot is taken of the CD substrate disk 28 '. The data of the snapshot captured by the camera 142 are digitized and subjected to a pixel analysis. The pixel analysis shows the quality (quality) of the surface layer to be removed from the CD substrate disk 28 'located in the respective field of view 146 . It can namely be determined on the basis of light received pixel by pixel from the camera 142 whether and in what quantity residues of a reflection metal layer or even a lacquer layer covering this metal layer are still present on the CD substrate disk 28 '. Such insufficiently machined areas contaminate the material of the substrate wafer. If a certain pixel number limit of such areas with residues is exceeded or if a certain detected minimum light intensity (possibly integrated over the entire CD surface) is undershot, a CD substrate disk is classified as poor quality and is sorted out. If, on the other hand, the results of the pixel analysis show that the surface layer has been removed sufficiently well from the CD substrate disk 28 'examined in each case, the CD substrate disk 28 ' is classified as of high quality and, if necessary, is subjected to further processing. This further processing can include, for example, machining and subsequent recycling of the substrate body material. The discarding of low quality CD substrate wafers compared to a derivation of high quality substrate wafers takes place via the switch 54 and the tracks 56 and 58 .

Claims (42)

1. A method for machining a surface layer of an information carrier disc ( 28 ) from its substrate disc, information carrier discs ( 28 ) being successively fed to a machining station ( 30 ) with at least one driven machining tool ( 128 ) and the substrate discs ( 28 ') obtained by machining from the machining station ( 30 ) can be transported further by guiding a plurality of successive information carrier disks ( 28 ) on a transport carrier ( 18 ) through the removal station ( 30 ) and during the passage through the removal station ( 30 ) on their side remote from the transport carrier, characterized in that the information carrier discs (28) are lying out on a moving and back based transport carrier tape (18) through the Abspanstation (30) therethrough, said remote transport carrier tape on the side of the information-carrying disk (28), a stationary Andr ckfeld (93) bears friction, is pressed by means of which the respective information carrier disc (28) into adhesive engagement with the transport carrier tape (18), and that the chipping at the transport carrier tape far side of the information carrier disc (28) by a plurality of milling tools (128) is carried out which rotate about axes of rotation (R) which are essentially orthogonal to the pressure field ( 93 ). 2. The method according to claim 1, characterized in that the machining tools ( 128 ) engage at least partially within the pressure field ( 93 ) on the information carrier disc ( 28 ). 3. The method according to claim 1 or 2, characterized in that the chipping tools ( 128 ) rest against the information carrier disc ( 28 ) within the openings ( 130 ) in the pressure field ( 93 ) surrounding them. 4. The method according to claim 3, characterized in that the openings ( 130 ) are circular and enclose the maximum circulation circuit (W) of the cutting tools ( 132 ) with a narrow annular gap (x). 5. The method according to any one of claims 1 to 4, characterized in that the chipping tools ( 128 ) are arranged in a plurality of lines arranged transversely to the strip running direction (A), the chipping tools ( 128 ) having different lines from one another and being in a gap their maximum orbits (W) overlap in the transverse direction. 6. The method according to any one of claims 1 to 5, characterized in that individual chipping tools ( 128 ) of the plurality of chipping tools rotate with different directions of rotation. 7. The method according to any one of claims 4 to 6, characterized in that the diameter (d) of the maximum circulation circles (W) is smaller than the diameter ( 2 a) of the information carrier disks ( 28 ). 8. The method according to claim 7, characterized in that the ratio of the diameter (d) of the maximum-recirculating circuits (W) of the Abspanwerkzeuge (128, 132) to the diameters (2 a) of the information-carrying disk (28) about 0.2 to 0.5, preferably about 0.3 to 0.4. 9. The method according to any one of claims 1 to 8, characterized by such a coordination of the dimensions of the pressure field ( 93 ) and the distribution of the machining tools ( 128 ) over the pressure field ( 93 ) with respect to the diameter ( 2 a) of the information carrier disc to be processed that in each phase of a chipping the respective information carrier disc (28), (a 2) covers over at least a quarter, preferably at least one-third, most preferably at least half of their viewed in the transport direction (a) the diameter (28). 10. The method according to any one of claims 1 to 9, characterized in that the pressure field ( 93 ) is rolling or sliding on the trans port carrier side of the information carrier discs ( 28 ). 11. The method according to any one of claims 1 to 10, characterized in that the pressure field ( 93 ) in conjunction with the transport carrier remote side of the information carrier disc ( 28 ) results in a frictional force under pressure, which is substantially less than the frictional force between the transport carrier ( 18th ) and the side of the information carrier disks ( 28 ) abutting the transport carrier ( 18 ). 12. The method according to any one of claims 1-11, characterized in that the machining tool ( 128 ) is a rotating tool ( 132 ) with a to the pressing direction (D) substantially orthogonal envelope surface (H) of machining elements ( 134 ) in the Envelope surface (H) lying processing edges ( 135 ) or tips. 13. The method according to claim 12, characterized in that the cutting tool ( 128 ) has approximately radially extending cutting edges ( 135 ) in the envelope surface (H). 14. The method according to any one of claims 1-13, characterized in that the at least one machining tool ( 128 ) is adjustable in the pressing direction (D) relative to the pressing field ( 93 ). 15. The method according to claim 14, characterized in that an adjustment drive ( 104 , 106 ) is provided for adjusting the chipping tool ( 128 ) relative to the pressure field ( 93 ), which is on the one hand on the pressure field ( 93 ) or a part firmly connected to it ( 96 ) supports and on the other hand acts on the stock removal tool ( 128 ). 16. The method according to any one of claims 1-15, characterized in that the Andrückfeld (93) is biased by a body independent of its distance from the transport carrier (18) is substantially biasing force against the transport support (18). 17. The method according to claim 16, characterized in that the biasing force is derived from the force of gravity on the components ( 93 ) forming the pressure field. 18. The method according to any one of claims 1-17, characterized in that the transport carrier ( 18 ) is biased against the pressure field ( 93 ) with a prestressing force which is essentially independent of its distance from the pressure field ( 93 ). 19. The method according to any one of claims 1-18, characterized in that the transport carrier ( 18 ) to adjust to different thicknesses of successive information carrier discs ( 28 ) is adjustable in sections. 20. The method according to any one of claims 1-19, characterized in that the conveyor belt ( 18 ) in the area of the pressing field ( 93 ) with its pressing field-far side slides over a support table ( 80 a, 80 b, 80 c), which the Press the conveyor belt ( 18 ) against the pressure field ( 93 ). 21. The method according to claim 20, characterized in that the support table is divided into a plurality of table segments ( 80 a, 80 b, 80 c) at least in the transport direction (A) and that the table segments ( 80 a, 80 b, 80 c) can deviate essentially independently of one another by overcoming the respective prestressing force in the direction orthogonal to the pressure field ( 93 ). 22. The method according to any one of claims 18-21, characterized in that the biasing force is derived from the spring force of at least one energy accumulator ( 90 a, 90 b, 90 c). 23. The method according to claim 22, characterized in that each table segment ( 80 a, 80 b, 80 c) is or are assigned at least one, preferably two, energy stores ( 90 a, 90 b, 90 c). 24. The method according to claim 22 or 23, characterized in that the at least one energy store ( 90 a, 90 b, 90 c) is formed by an elastic rubber body, a compression spring, or a pneumatic spring element. 25. The method according to any one of claims 1 to 24, characterized in that the pressing field is formed on a pressing plate ( 92 ) provided with a passage ( 130 ) for the at least one machining tool ( 128 ), and also has a bearing plate. (96) driven for the Abspanwerkzeug (128) associated tool drive spindle (36) and a tool drive spindle (36) tool drive (32) is provided. 26. The method according to claim 25, characterized in that the tool drive spindle ( 36 ) and / or the spindle bearing ( 100 ) relative to the bearing plate ( 96 ) in the pressing direction (D) is adjustable. 27. The method according to claim 26, characterized in that a screw drive ( 104 , 106 ) is provided for adjusting the spindle bearing ( 100 ). 28. The method according to claim 27, characterized in that the screw drive has at least one spindle ( 106 , 108 ) with a spindle axis parallel to the pressing direction (D). 29. The method according to any one of claims 1-28, characterized in that a chip suction is assigned to the at least one chipping tool ( 128 ). 30. The method according to claim 29, characterized in that the chip extraction has a suction channel leading past the at least one machining tool ( 128 ), which, if desired, is enclosed between the pressure plate ( 92 ) and the bearing plate ( 96 ). 31. The method according to claim 30, characterized in that the chip suction has a connection channel (at 130 ) leading from the respective machining point to the suction channel. 32. The method according to claim 31, characterized in that the connection channel (at 130 ) is formed by the annular gap (x) between the chipping tool ( 128 ) and the edge of an opening ( 130 ) accommodating the chipping tool ( 128 ) of the pressure field ( 93 ) is. 33. The method according to any one of claims 1-32, characterized in that it is carried out in the context of a method for recovering the raw material of the substrate wafers ( 28 '). 34. The method according to claim 33, characterized in that the substrate wafers ( 28 ', 28 '') are fed to a comminution station after machining. 35. The method according to claim 33 or 34, characterized in that the machined substrate disks ( 28 ', 28 '', 28 ''') are subjected to a quality inspection (at 40 ) after passing through the machining station ( 30 ), in particular with regard to the quality of the machining and substrate wafers ( 28 ''') of inadequate quality are discarded and, if desired, subjected to renewed removal. 36. The method according to claim 35, characterized, that the quality inspection on an optical observation of Remnants of the surface layer in terms of amount and / or ver division is based. 37. The method according to any one of claims 1 to 36, characterized in that the transport carrier belt ( 18 ) is made at least from its surface of a material, such as PVC, which in connection with the respectively adjacent surface of the information carrier disc ( 28 ) results in an adhesive material pairing. 38. The method according to any one of claims 1-37, characterized in that the pressure field ( 93 ) at least on its surface ( 138 ) is made of a material, such as PTFE, which is in connection with the respective adjacent surface of the information carrier ( 28 ) results in a sliding material pairing. 39. The method according to any one of claims 1-38, characterized in that the information carrier discs ( 28 ) by stationary or / and on the transport carrier ( 18 ) attached positioning means ( 38 ) in the direction transverse to the transport direction (A) and / or along the transport direction (A) orderly location. 40. The method according to any one of claims 1-39, characterized in that the transport carrier ( 18 ) the information carrier disks ( 28 ) at a speed in the range of 15-25 m / min., Preferably of about 20 m / min., In the conveying direction (A) moves. 41. The method according to any one of claims 1-40, characterized in that the substrate disks ( 28 ', 28 '', 28 ''') consist of a plastic, in particular a thermoplastic, such as polycarbonate. 42. Device ( 10 ) for machining a surface layer of a laminated body ( 28 ) from its substrate layer, in particular for carrying out the method according to one of claims 1-41, comprising a removal station ( 30 ) with at least one driven removal tool ( 128 ) wherein the device ( 10 ) further comprises:

• - A transport carrier ( 18 ), which is designed to pass a plurality of successive laminated bodies ( 28 ) through the removal station ( 30 ) to remove the laminated bodies ( 28 ) on their side remote from the transport carrier during the passage through the removal station ( 30 ) to lead

characterized in that the device further comprises:

• - A pressure field ( 93 ) acting on the side of the laminated body ( 28 ) remote from the transport carrier, by means of which the laminated body ( 28 ) on the transport carrier ( 18 ) during the passage through the removal station ( 30 ) at least partially in adhesive engagement with the moving transport carrier ( 18 ) are pressed,

if desired, the device is supplemented by the device features from the method according to one of claims 2-41.