DE1522989A1 - Device for recording records - Google Patents

Description

.j IL

• Expl. J

DECCA Limited, Decca House, 9 Albert Embankment, London S.E, 1

England

Record recording device

The invention relates to the record recording and in particular the part of the record recording where a cutting needle is about to make a groove in an empty record cut from a material that can be cut according to a signal to be recorded. It is known that the treated in this way Plate can be used as a father plate for making lifelike copies of the original plate.

The invention is particularly directed, but not necessarily limited to, apparatus for recording of the incoming signal in fine grooves by cutting needle movements to indicate the variations of the instantaneous Display the amplitude of an input signal. With such Devices usually use a cutting needle, mostly a sapphire needle, which has a flat front cutting surface

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owns, which on its outer edges a few thousandths of a liilliineter is bevelled far. The purpose of these bevels is best explained by looking at how the The cutting needle is viewed in the absence of a signal and a groove is therefore cut, the side flanks of which are considered to be straight can be viewed. In this case, the front surface punctures the panel material, generally nitrocellulose varnish, off, the cutting dust is usually sucked off by a suction line that is attached near the cutting needle

"is, and the rear edge of a bevel that is normally encloses an angle between 30 ° and 60 ° with the groove side, smooths the side surfaces of the cut ** illegs. But even if a cutting needle with bevels is used, the played signal will still be distorted. by the roughness of the side surfaces of the groove, and the invention is concerned with a record recording £ prät, with which a lower roughness of the side walls can be achieved so that the aforementioned kind of distortion is reduced

k can be. It is common practice to heat the cutting needle evenly during cutting in order to achieve a better cutting effect and at the same time to be able to reduce the force to be exerted on the needle tip. This reduction in needle load makes it easier to cut shallow thin grooves. If the temperature remains the same, however, the smoothing effect of the bevels is reduced if the needle tip is displaced and the angle between the inclined surface and the groove wall becomes smaller.

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According to one feature of the invention, a device for recording a record is provided with: a beveled cutting needle, which performs cutting movements with respect to the plate in accordance with the signal to be recorded, a device for heating the cutting needle as well as a device for controlling the Heizuiigseinriclitung according to the amplitude of the to be recorded Signal, causing the panel material to be used by the cutting needle is processed, the more it can be softened, the greater the amplitude of the signal.

It was found that with this type of record cutting occurring distortion is caused by the fact that when cutting the groove with a changing waveform the bevels of the cutting needle during part of the period of the waveform below less than the maximum Angle opposite the sides of the groove. This creates a Compared to before, worsened smoothing effect, and rough spots on the groove walls are not affected by the bevels eliminated. The smoothing effect of the bevels is improved as the temperature of the panel material increases, which is why when the peak amplitude of the signal increases, leading to leads to a reduction in the angle between a bevel and the groove wall, the cutting needle and the plate accordingly heated to improve the smoothing effect of the bevel.

The heating device for the cutting needle can therefore be supplied with a signal whose amplitude is the amplitude of the signal to be recorded, so that the temperature

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and thus that of the plate, the material of which is heated by the cutting needle, according to the amplitude of the record to be recorded Signal varies.

In one embodiment of the invention, a device for supplying a direct current signal for heating is the Cutting needle provided, the magnitude of the signal being a predetermined amount and the heating control so is designed so that the amplitude of the direct current signal is in accordance with the peak amplitude of the signal to be recorded Signal changes. With this arrangement, the specified signal provides the constant heating for the cutting needle, the absence of recording signals is kept at a constant temperature while a changing in accordance with the signal to be recorded Signal can be rectified and superimposed on the specified direct current signal in order to soften the panel material to achieve as modulated for recording Signals is required. In another arrangement for heating the cutting needle, this could be achieved by using a high-frequency signal of a given amplitude are heated, an amplitude modulation of the high-frequency signal corresponding to the strength of the signal to be recorded being carried out could in order to vary the heating of the cutting needle accordingly.

In vinyl record recording, it is common practice to record an audio signal on magnetic tape and the process of record recording control by the signals recorded on the tape

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to let .. Therefore, the facility to control the Form the cutting needle heating so that the recorded on tape Signal is amplified and rectified to generate a current to heat the cutting needle. At a Embodiment is used to heat a piece of resistance wire that is wound around the cutting needle and it directly warmed up. But it is also possible to direct a stream of air to the cutting needle and this in accordance with to heat the amplitude of the heating current.

When the amplitude of the heating current increases, it does Time constant of the heating of the cutting needle, which eimzwar has small but finite mass, noticeable The cutting needle is therefore not momentarily heated to the desired temperature. It is therefore still according to the invention provided to attach a further playback head to the magnetic tape device, which sends the signal to be recorded at an earlier point in time than it is recorded by the playback head controlling the changes in the movement of the cutting needle. is taken, with the leading playback head sending a signal passes on to the heating device. The physical distance along the Msgnötbandes between the two playback heads en depends on the time congestion that occurs when the cutting needle is heated and the running speed of the tape. In general, the two heads need only be eatferat a few inches apart. With this arrangement It is important that the tape speed is maintained during the passage of the entire tape length on the sink

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remains more or less constant, but with modern tape recording systems with friction belt drive none offers that Trouble.

The invention also provides a method for the record exiauf would take in which a beveled cutting needle is used to cut the grooves in the disc according to a signal to be marked and in which the cutting needle is heated according to the amplitude of the signal to be recorded.

For a device of the type described so far we vein cutting dust from the panel easiest removed by attaching a suction line next to the cutting needle. This suction line can also be used in the invention to quickly cool the cutting needle (by sucking air past it) so that its heat can be quickly dissipated when the strength of the signal to be recorded decreases. However, the invention has another possible improvement which is important in an apparatus of the present type. As mentioned, the material used for the plate is usually a nitrocellulose lacquer or a cellulose acetate, in any case a combustible substance. In a heated cutting needle, therefore, there is the danger that when the needle reaches a high temperature, the cutting dust is ignited in the suction line and gives rise to a dangerous fire, especially in the waste container for cutting dust. In the case of the device specified here, this risk is particularly great because the cutting needle tip can get very hot with signals of large Uaxlmalamplitude.

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A further feature of the invention therefore represents a device which enables a stream of carbon dioxide or another extinguishing gas to flow in the dust line. The carbon dioxide can be fed into the dust extraction line or into a line from a carbon dioxide source, which can have a slight overpressure, causing an air flow on the cutting needle. With such a device, the risk of fire in the dust pipe or at its outlet can be reduced considerably. The control of the carbon dioxide flow in the dust line or in the gas supply line can be carried out by a device which is responsive to the strength of the current supplied to the heating device. In one embodiment of this control, the current fed to the heating device actuates a relay which opens a valve and thereby allows extinguishing gas to flow into the dust line or the gas supply line when the heating current reaches a certain value. Instead or in addition, devices that respond to the heating current level can be provided which control the gas flow in the extinguishing gas line in such a way that ( the amount of extinguishing gas increases with the strength of the heating current be provided that flushes the dust pipe with extinguishing gas when a certain heating current is reached.

The invention is described in detail below and explained with reference to the drawings, which represent the following:

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Fig. 1: a block diagram of a control for a record recording device ;

Figo2: a schematic view of a record recorder s;

3: a simplified perspective view of a Cutting needle;

4A and 1 ig.413: the mode of operation of a cutting needle;

5s a schematic view of a further part a vinyl recorder and

iig.6: a circuit diagram as a modification of the one shown in iig.1 Circuit.

The (ir \ ind lay of the recording of signals on records as 3 prerequisites for the production of cirammophone records are fixed and do not need to be discussed in detail. As is well known, it is common in all modern recording studios for the artist to perform a performance piece Play on magnetic tape or tapes, which are then cut. Then the magnetic tape is played and the recorded signals are used to control the work of a cutting needle which cuts HiI.lon into an acetate disc uses wild r.ur manufacture of molds for the production of a large number] plates üramrnonhünüchal;.. this work inveino is known in oinuVlnon the ^ -rfindung beschäl Untitled !! ioh as oi imagines, with the ^one jodu] it ionontuio in which the signals al ¹ · HiJl (Ji! have been cut into the Jiaclplatte. Figures 1 and ? /: ebon Pin voi cinfacht it S (; h (; ina the Geifiln wiudni «Uj (? wfUircnd do ;; Vort ι ngn the arts stlers on ge v \ 'iclinct en iiicnal-n nind aul the Lja / matband 1o recorded,

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which is led from Holle 12 to Holle 11. These signals are picked up by the playback head 14, which is then moved past by the tape drive 13. The output from playback head 14 is amplified by amplifier 15 and fed to an electromechanical Yandlor, which is indicated schematically by box 16. Output of the waveform of the signals picked up from the tape Io ”. Since the special construction of the cutting head is of no importance for the invention, the mechanical details of the cutting head are not discussed in B ¹ ig.2, however, the main features of a cutting device are shown.

The motor IB in FIG. 2 with its Abtriobswello 19 drives a turntable 21 via a kinematic chain schematically denoted by 2o, which moves an empty plate " 2 " past the son's needle 17 in the usual way. During recording, the cutting head is continuous and performed by I'lnttenrand from inward, to which the motor 25 drives a lead screw 24 on which the summarily labeled 255 cutting head is mounted ο Part of the cutting head 2! 3 in anchor 2b dor pivoted 1st and since light) ^ jwognngeii. The tendon needle 17 is allowed, and a coil 27 is excited by the output current of the amplifier 15 and generates a flow of force which corresponds to the magnitude of the output current; and düiuimt speaking lateral movements dor tendon dnadol. 17 causes »The ^{apparatus given in L 1} Ig, 2 is for the purpose of simplifying the explanations; strong

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schematisLort has been. It is recalled that even for side step the construction of the cutting head π 2 Jj is very complicated int and that moreover, according to dom iJtande of the Tochnik, variable groove spacing and variable melinite depth possible int. In British patent specification 77o 465 or, Ln of the British Patent 7o8! ο 57 is angeg jbon that the Killenabstan I ¹ the plate exerted on pressure force controlled by varying the rotational speed of the Kyoto rs 2.5 or witches Itttiefe by changing from the Sehneidnadel aui can Verden. For this purpose, the τ) η patent specifications and Ln rest on ILe Standard! iterature on these technical details.

In a simplified perspective view; tends the υ ig, 3 one at. the scarf LpIattenaufnähme in common "sehn" idnadel. The ugle, designated as a whole with 17, has an IladoUialter Jl, ler an elne.a Ank'jr atigtjbr.acht 1: 5t, // elc-her by the, Ylokiunr 2'1 (VLi ·;,?,) Can be distracted . The holder 51 carries a sapphire needle S-. The ι «ade 1. j2 b-isitat a plane tendon?) Idfläciie Jj, otherwise has the needle. iLre i, -i juersehnit t, and di »· tendon iiifi-i'ilie is a tendon of Jia -nierschnittiikruis. The lower part of the tendon Ll surface; 3 is vorjiingt au a rounded Spit /, ο, the front Canton .H the Sfhneidi'iache be referred to as chord Idkanten. Every Kant; · .. · i.-jt bevelled, and one of the iCantonabiichraps is In L · 'ig. j with y> be /, -.i lehnet, The cut-offs v / erde ti generally as illätation facets: i (ii (; hnet, and the back. '/ arrt ige edge (.'JoJ a smooth facet: ette is (was .ungsknnte g'jnannt, behind the Glättungskunte 36 winl the lower rear Ii;! ielah;;! t HNTT by flat '' laugh 37

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limited to the top to the top edges of the facets 35 are enough. There is a heating coil around the tip of the needle 4o looped, the meaning of which is given below.

FIGS. 4A and 4B illustrate, as top view drawings, the cutting process performed by the visual cutting needle. After Figure 4A, no signal is recorded and the cutting needle 32 moves in a seal parallel to lines 18 which indicate the kill to be cut. In this mode of operation, the cutting edges 34 first produce the groove walls, which are then smoothed by the smoothing edges 36; 19 denotes the smoothed walls. Under these circumstances, a smoothing facet 35 assumes an angle between 30 ° and 60 ° with respect to the initially produced Killenwändcm. This angle has a lower limit: if r.xx is small, no effective smoothing occurs and rough spots remain in the killer walls. On the other hand, if the angle ku is large, the beveling becomes more difficult, and rough spots then also remain.

In Fig. 4B the effect of the son's needle on the U is shown in a cutting of a modulated signal. It does not mean that the linear smoothing facet 3! 3 ^{assumes a smaller than the optimal angle compared to the 1ι} ί1 '\ unwall «inon, while the κ actually internal smoothing facet is at a larger than optimal angle. Accordingly, when a moduli egg tone signal is recorded - and this applies to the greater part of the recording time - rough cleats remain in the groove wall if the dio-smoothing acette was at an angle deviating upwards or downwards from the optimal angle. 9 (] 9 ß / 2/0 R ^f 7

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As already mentioned, it is customary to heat the cutting needle to facilitate the cutting process. However is the resistance offered by the plate to the cutting is always the same with constant heating, and those mentioned Difficulties are not eliminated with it.

The invention tries to solve the problem by the fact that the heating of the cutting needle in accordance is varied with the amplitude of the signal to be recorded.

Returning to Fig.1: from the tape 1o are signals before they are picked up by the playback head 14, fed to the playback head 41 and from there via the switch 42, the amplifier 43 and the rectifier 49 to the input of a Adter stage 45. The input variable fed to adder 45 therefore represents an amplified and rectified form of the Signal that controls the movement of the cutting needle 17. This signal or these signals become a direct current signal superimposed, which is fed to a second input of the adder 45 from a direct current source 44. The output size As mentioned earlier, the adder 45 goes into the heating winding 4o. As it is known per se, cutting needles to be provided with heating windings, the special configuration of the heating device 4o need not be discussed, especially since the place of attachment of the heating coil and the lead wires in their installation only have to be chosen so that they do not interfere with the normal operation of the cutting needle. According to the invention, the direct current signal becomes more constant Strength another DC signal superimposed,

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whose amplitude is the maximum amplitude of the signal to be recorded by the cutting needle. If the cutting needle records a modulated signal, the heating coil heats up 4o the cutting needle completely accordingly, whereby the heat of the cutting needle is transferred to the plate and this increasingly softened when the oscillation amplitude of the cutting needle grows.

An important characteristic of this working method should also be mentioned: The cutting needle has a small but finite mass and therefore needs a finite time before it heats up according to the supplied signals. This consideration leads to the phase of the signals in the amplifier 43 is given a lead over the phase of the same signals appearing at the output of the amplifier 15, so that an increase in the maximum amplitude of the recorded signal anticipated by the heating circuit. In the circuit shown in Figol, this phase lead is thereby achieved that a finite distance between the heads 14 and 41 is placed. The distance between them must vary according to the tape speed and the required time delay are chosen so that a necessary change in amplitude of the superimposed direct current a sufficiently long time before the recording of the associated signal by the cutting needle proceeds so that the cutting needle is available for a sufficiently long period of time for the heating process.

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In practice, however, it has been shown that the time constant for heating the cutting needle is so small that it often does not need to be taken into account. It has mostly been found that when cutting long-playing records, a phase difference between the recording and the excitation current signals is not necessary to compensate for the time constants for the heating process, but that compensation is necessary if records are cut at 45 revolutions per limit. In any case, however, it is possible to completely omit the pre-adjusted playback head if, for example, a suitable delay 3 stage is provided at the output of the amplifier 15 instead. If no phase advance is required, the amplifier can be connected directly to the playback head 14 via switch 42.

The working method described is also the same as when working the cutting dust generated by the cutting needle. The dust is usually picked up by one near the cutting needle arranged suction line led away. Such an arrangement is shown schematically in FIG. 5 drawn. The suction line 59 is attached in front of the cutting needle and goes into a pump 5o over, which conveys the dust into an exhaust gas or waste container. Obviously there are many ways in which, according to the Invention, the heating of the cutting needle reached a much greater extent than with the previous type of record recording usual i3t. Therefore, there is a great risk that the cutting dust in the suction line can ignite and cause a dangerous fire, especially with the

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Dust collector. Normally, line 51 a stream of air is passed past the cutting needle; the line 51 receives compressed air from the compressed air source 54 via the Valve 53. The air picks up the dust and is sucked off through line 59. According to the invention, the air flow,. ' exiting line 51, exploited in other ways, because the air flow can bring about constant cooling of the cutting needle. It is thereby achieved that the time constant in cooling the cutting needle becomes very small, so that the cutting needle temperature drops rapidly when the heating current is lowered. The cutting needle can still get extremely hot when the recorded signal has a high amplitude. Another feature of the invention is that valve 48 can be opened around a stream of extinguishing gas (COp) from the container 55 into the Line 51 to enter. The extinguishing gas could in itself constantly flowing, but that would be wasteful, and according to the invention, devices are provided that one Allow the gas stream to flow only when the amplitude of the signal fed to the heating coil exceeds a certain level. For this purpose, an output variable of the rectifier 49 is fed to a Schmitt trigger 46, on which an output variable is only occurs when the amplitude of the rectifier output (49) is above a certain value given by the ignition point of the material used for the plate. The Schmitt trigger 44 actuates a solenoid 47 for a valve 48, which opens the line 51 for a flow of extinguishing gas}

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carbon dioxide can be used as an extinguishing gas. The gas flow is only interrupted when the maximum amplitude of the recorded Signal decreases.

So far, the invention has been described primarily with regard to page writing recordings. In this recording mode, the signals that have just been recorded are recorded in just one plane by moving the cutting needle. However, the invention is also applicable to devices with which stereo signals can be recorded on disks. It is known that with this type of recording the cutting needle must be moved in two mutually perpendicular planes. In general, these planes are both offset by 45 ° with respect to the normal of the recording. In general, the peak amplitude of a signal recorded in one channel is not equal to that of the signal in the other channel. In these circumstances a compromise must be reached. Fig. 6 shows a useful circuit here. The two stereo channels 6o, 61 and 62, 63 are fed to a summing and differential circuit which has two transformers 64 and 65 with primary windings 67 and 68. Each transformer has two secondary windings; of which the first pair (f> 9.7o) is connected in series and the second pair (71.72) in series with one another. ! V / hen mm the stereo channels in 'are hase, on Vei rstärkei 43, the sum of the signals generated in the stereo!' Imnlon.,: * Imi the fjl s m signal c of phase, so the Vei is: j1 Hrlic ' i ilafs]) 1.ij (ι eui '. ^ igna] r, U {', efüh.rl.

Pateii ti »-ι sayings:

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Claims (1)

ι * Claims 1 · Device for recording records, characterized by a beveled cutting needle (32), known per se, which performs cutting movements in relation to the plate (22) in accordance with the signal to be recorded, in conjunction with eLner also known device for heating the cutting needle and a device for controlling the heating device according to the amplitude of the signal to be recorded, whereby the plate material that is processed by the cutting needle, the more can be softened, the greater the amplitude of the signal becomes. 2, device for recording a record according to claim 1, characterized by means for supplying a direct current signal for heating the cutting needle and in that the means for controlling the heating is arranged so that the amplitude of the direct current signal is in accordance with the peak amplitude of the signal to be recorded can be varied. 3. Device for recording a record according to claim 2, characterized characterized in that means (43, 49) are provided for amplifying and rectifying the signal to be recorded and means (45) for combining the rectified signal with a DC signal of constant amplitude and for supplying the combined signal to the heating device (4o). 909842/0657 4. Device for SchalIp Lattenaufnähme according to claim 1, characterized in that a device sum supplying a high frequency signal for heating the cutting needle is provided, and that the device for controlling the heating device, the amplitude of the ilochfrequonasignals according to the peak amplitude to: '*} To modulate the gluing signal vormag. 5. Device for SchalLpLattenaufnähme according to one of claims W or 3, characterized by a device with which the phase of the variations of the equal current signals can be given a lead over the associated variations of the burst amplitude of the signal to be recorded. 6. Device for recording panels according to claim 5 »thereby characterized in that the signal to be recorded is initially on magnetic tape. (Ιο) is recorded and a harvested playhead (14) intended to generate signals for the needle control is as well as a second playhead (40 »which converts these signals "a period of time before signal formation by the first playhead (14) reproduces, the period of time corresponding to the time constant in the process of heating the cutting needle. 7. Device for recording records according to one of the preceding claims, characterized by a device (51 » 53,54) for bypassing a flow of cooling gas on the cutting needle (31). 909842/0657 1522289 8. Device for sound pi attenaufnalime according to one of the claims 1 to 4 with lead to the Y / egf clocks from dust, thereby characterized in that a shut-off device (48) is provided which allows a stream of carbon dioxide or another extinguishing gas to be let into the dust discharge (59). 9. Device for record recording according to claim 5j thereby characterized in that the shut-off device (48) the Lb'schgasstrom then releases when the heating current amplitude exceeds a predetermined value. f 10. Device for Sehall plate mounting according to one of the preceding Claims, characterized in that the heating device Means for the power supply ευ of a wire spool (4o) which surrounds the cutting needle (31). 11. Method of recording records with a beveled Cutting needle that; in a plate grooves in accordance intersects with a signal to be recorded, characterized in that that the cutting needle is heated in accordance with the amplitude of the signal to be recorded. 12. A method for recording a record according to claim 11, el; - Viruses characterized that the cutting needle by a DC signal is heated, the amplitude of which corresponds to the peak amplitude of the one to be recorded. Signal changed will. 12. The method of vau ilehaTlplattonaufnahme according to claim 12, characterized in that the lichnei needle with ο in a con- 90984 7/0657 6AD constant direct current signal is heated, and that this is the one to be recorded Signal corresponding signal is rectified and superimposed on the constant direct current signal. '14. Method for recording records according to one of Claims 12 or 13, characterized in that because of dee finite value of the time constants that occur when the cutting needle is heated to compensate for the variations of the DC signal is an advance in phase with respect to the associated variations in the peak amplitude of the signal to be recorded. 909842/0657 Blank page