JPS5996565A - Forming device of original disc for recording - Google Patents

Abstract

PURPOSE:To suppress sharply stick slip vibration and vibration due to the unbalanced rotation of an original disc or the like by forming a guiding part supporting a vertical load out of a sliding bearing of a feeding board as a sliding surface consisting of resin and forming recessed parts on the sliding surface to supply pressed air into the recessed parts. CONSTITUTION:Two recessed parts 37 are formed on a resin coating layer formed on the lower surface of a sliding block 32. Air feeding holes 38 for discharging gas are formed on the bottoms of the recessed parts 37 respectively and pressed air supplied from a pressed air source 39 such as a compressor is supplied to the recessed parts 37. The connection surface pressure between the surfaces of the resin coating layers 35, 36 on the lower surface of the sliding block and the upper surfaces of the sliding guides 30, 31 can be optionally set up by adjusting the pressure of the pressed air to be supplied to the recessed parts 37. Since a resin material reducing the difference between a statical friction factor and a dynamic friction factor is adopted as the sliding surface and contact force between the contact surfaces is reduced by air pressure, the generation of stick slip is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a disc recording master production apparatus for producing a master disc for producing a video disc or a record disc such as a digital audio disc.

Conventional configuration and its problems An example of a schematic configuration of a conventional disk recording master production device is shown in FIG. Reference numeral 1 denotes a recording master disk made of glass coated with a resist on the surface thereof, and is fixed to a rotating shaft 1III13 that is rotatably supported by a bearing 2, and is rotated by a rotation drive means (not shown) such as a DD motor. can be strengthened. The feed table 4 on which the bearing 2 is mounted is given linear motion by rotation of a feed screw 6 combined with the nut 5 via a naso l-5 fixed to the feed table 4. The feed screw 9 is driven by the drive motor 7 into the reducer 8. It is driven via the shaft coupling 9. Reference numeral 10 denotes a support base that rotatably supports the feed screw. Reference numeral 11 denotes a slide bearing that guides the linear motion of the feed base 4, and a slide bearing used in a tool rest of a machine tool, etc. is used.

Recording of images and audio information on the master disc (hereinafter also referred to as cutting) is performed using a laser beam 12. The laser beam 12 is generated by a laser oscillator 13,
The video and audio signals to be recorded are conveyed to the laser beam by a modulator 14. Reference numeral 16 denotes a mirror fixed to the optical bench 16, which allows the laser beam 12 to enter the master disc perpendicularly. Further, the surface plate 18 on which the above-mentioned device is mounted is supported by an air damper 19, so that vibrations from the floor are not transmitted to the disk master recording device.

With the above configuration, the master disc 1 simultaneously performs linear and rotational movements relative to the fixed laser beam 17, and a signal is cut spirally onto the master disc. Based on the cut master disc, a mold called a stambar is created through processes such as etching and electroforming to mold the final record disc. Therefore, the signal cut by the disc recording master production device will be transferred to the record as is, but the track pitch accuracy of this recorded signal has a significant impact on the quality of the reproduced image and sound. IH. That is, in the disk recording master production apparatus, if the master and the laser beam do not perform a predetermined relative movement, the recorded spiral track will fluctuate and the trunk pitch will fluctuate.

This trunk pitch variation is 1. When recording a record, it makes it difficult for the cattle pickup to drive correctly on the recording track, and in the case of a frame edge, the adjacent recording trunk will over-ramp, Recording and reproducing of the signal itself becomes impossible. Therefore, extremely high precision is required for the linear movement of the mechanical parts of the disk recording master production apparatus, especially the feed base. By the way, in a disc recording master production device for VHD video discs, it is necessary to ensure an accuracy of 1.3571±0.1μ for the adjacent l/rack pitch, and since the master disc's rotational speed is 90 Orpm, the number of Feed rate is 1,215ran/mM
This is an extremely slow speed.

Under such extremely low speeds, and in order to feed a considerably heavy feed table carrying a rotating body extremely smoothly with a feed unevenness of 1.36μ or less than 0.1μ, the above-mentioned conventional disk recording master production method was used. The device has the following problems. One size,
When sliding a heavy object at extremely low speeds, if the slide bearing of the feeder is composed of a plain bearing, stick-slip, which is unstable vibration, will occur, causing uneven feed speed of the feeder and preventing it from reaching the specified track. The problem is that pitch accuracy of 4'1C cannot be maintained. This stick-slip phenomenon is
For example, it is known that by adopting a static pressure gas bearing or a rolling bearing in the slide bearing part, jQIj can be eliminated or reduced to dog IJ. The centrifugal force caused by the unbalanced rotation of the rotating body consisting of the rotation 11+ and rotation 11+ applies a vibrating force to the feed table in synchronization with the rotation of the master, which causes the problem that the feed table vibrates, making it practically unusable. . On the other hand, in the case of a sliding bearing that uses a sliding bearing, the vibration force due to this unbalanced rotation does not cause vibration of the feed table because the vibration energy is absorbed by friction in the sliding part, but as mentioned above There is a problem of slip vibration generation. In any case, with conventionally known bearing types, vibrations caused by stick-slip or rotational unbalance of the master disk can be reduced to zero.
．． It was extremely difficult to suppress the vibration to 11J, which is less than 1μ.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks, and provides a disk recording master production device that achieves high-precision ρ cutting.

Components of the Invention The present invention comprises a rotating shaft having a rotational drive means, a bearing for supporting the rotating shaft, a feed stand on which the bearing is mounted, and a linear drive means for providing linear motion to the feed stand. , consisting of a slide bearing that supports the load of the feed table and guides the linear motion, and means for irradiating the master with a laser beam carrying an information signal to process and record the information signal, A guide part that supports vertical loads is connected to the top surface of the slide guide fixed on the device base;
The lower surface of the slide block is fixed to the feed base, and the lower surface of the slide block is made of resin having one or more four parts on the surface.

The bottom of the recess has an opening 1 for gas
11 pressure gas is introduced into the recess through this opening to reduce the contact pressure between the slide block and the AfJ slide guide, which is caused by sliding friction. In addition to suppressing the occurrence of slip JR motion, it also suppresses the vibrations associated with one unbalanced rotation of the master, increasing the linear motion accuracy of the feed platform to large [1], making it possible to record high-precision information signals. It is something to do.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to Nos. 2 to 6.

FIG. 2 shows the structure of the disk recording raw malt sweat producing apparatus of the present invention as viewed from the feeding direction of the feeding base section. In the figure, reference numeral 21 denotes a rotary table, and 22 denotes a rotary table on which the master is mounted. The rotary table is rotatably driven by a DD motor 23 and fixed to a rotary shaft 26 that is rotatably supported by a hydrostatic gas type bearing 24.

The bearing 24 is fixed to a feed base 26. By the rotation of the feed screw 27, the feed base 26 is
is driven in a straight line. The linear movement of the feed table 26 is guided by a slide guide 3 made of v and i iron fixed to the base 29.
0.31 and a slide bearing constituted by slide blocks 32, 33, and 34 fixed to the feed base 26.

Here 1. The slide blocks 32 and 33 are bearings that support the vertical load of the feed table 26, and the slide blocks 34 and
, which guides the horizontal position of the feed table 26, and is constituted by a static air bearing. A resin coating layer 36.36 made of Teflon is formed on the lower surface of the slide block 32.33 that supports vertical loads, and slides in contact with the upper surface of the slide guide 30.31.

Figure 3 shows the slide guide 3o and slide block 32.
FIG.

FIG. 4 shows the structure of the slide block 32.
The resin coating layer provided on the lower surface (upper side in FIG. 4) of the slide block 32 is provided with two recesses. Air supply holes 38 for gas discharge are provided at the bottoms mi of the recesses 37, and pressurized air supplied from a pressurized air source 39 such as a compressor is supplied to the recesses 37.

The structure of the other slide block 33 is also similar. still,
40 is a pipe that supplies pressurized air to the four parts 37.

” In the structure of the leek, the surfaces of the resin coat layers 35 and 36 on the lower surface of the slide block and the slide guides 30 and 31
The connection surface pressure with the upper surface of the recess 37 can be arbitrarily set by adjusting the pressure of the pressurized air supplied to the recess 37. When the supply pressure of pressurized air is atmospheric pressure (
When pressurized air is supplied (in the case of no pressurized air), the heavy surroundings (several tens to several ohms (7ω) of the feed alloy body are applied to the contact surface between the surface of the resin coat layer and the slide guide, so it is relatively difficult to The resin surface, which has low mechanical strength and low abrasion resistance, may be damaged or suffer significant wear, making it difficult to ensure the reliability of the device.

As the pressure of the pressurized air increases, part of the weight of the feed base is supported by the air pressure in the recess, the contact surface pressure decreases, and eventually the weight of the feed base decreases. The entire structure is supported by air pressure, which means that the contact surface pressure almost reaches zero.

Therefore, the pressure of the supplied air is set so that the contact surface pressure of the resin coat layer is less than 0, and is lower than the contact pressure that is sufficiently reliable in view of the mechanical strength and anti-wear properties of the resin coat layer.

Next, we will explain the principle by which the accuracy of signal recording on the master disc is improved to 11" by using the above configuration.

The vibration behavior of the feed table is basically expressed as a mechanical vibration model shown in FIG. That is, in FIG. 5, the mass M represents the mass of the feed alloy body, the spring is the spring diameter of the feed screw, and mr is the amount of rotational unbalance of the rotating body. The linear motion of the feed carriage corresponds to the movement of the attachment to the spring at a constant speed.

Now, as mentioned above, the factors that affect the accuracy of signal recording on the master disc are: (1) stick-slip of the slide bearing of the feeder; and (2) vibration of the feeder due to unbalanced rotation.

First, regarding the first factor, the lower surface of mass M and the sliding surface S
The main controlling factor is the difference in static friction between the two, and the smaller this difference is, the less stick-slip d: occurs. −
In the configuration of the present invention, a resin material with a small difference between the static friction coefficient and the dynamic friction coefficient is used for the sliding part, and the contact force between the contact surfaces is reduced by air pressure, so stick-slip d does not occur.

Next, regarding the second factor, rotational imbalance 'A' rll
The centrifugal force caused by r is expressed as mrω2sinωt (ω is the rotational angular velocity of the rotating body), and this centrifugal force is considered to be a forced vibration problem in which this centrifugal force is applied to a 1-degree-of-freedom vibrating body made of a mass M and a spring. I can do it.

At this time, the sliding friction between the lower surface of the mass M and the sliding surface S acts as a damper that dampens this vibration, and the larger the frictional force, the more the vibration of the mass M, that is, the feed base, is suppressed. This effect cannot be expected if the slide block is completely levitated by fluid pressure or if the slide bearing is configured with a rolling bearing or the like. In the configuration of the present invention, the resin sliding surface is brought into sliding contact with the upper surface of the slide guide, and the friction damper effect absorbs vibration energy and suppresses vibration.

Now, regarding the above two factors, the contact surface pressure of sliding has contradictory tendencies. In other words, increasing the contact surface pressure improves factor (2), but the problem of factor (2) becomes more likely to occur. Therefore, optimal conditions exist for setting the contact surface pressure. This is the area of the resin sliding surface, the area of the recess provided on the surface of the resin coating layer, or the M shown in Fig. 6.
The mechanical structure factors corresponding to the values of , and , are greatly influenced by the magnitude of rotational unbalance, etc.

In the present invention, the air pressure supplied to the four parts of the resin coat layer allows this contact surface pressure to be adjusted freely and optimally, thereby achieving a significant improvement in signal recording accuracy on the master disc.

FIG. 6 shows the results of measuring the vibration vibration [IJ (aftershock rl)) of the feed table when an excitation force of 3 ogf is applied to the feed table in the disk recording master production apparatus of the above embodiment. The vibration riJ was measured using Michelson interference using a laser. A in the figure is the result in the case of the example of the present invention. At this time, the air pressure supplied to the four parts of the resin coat layer was 36 kg/cd, and the contact pressure of the resin sliding surface was set to about 2 qf/crl. On the other hand, Phantom B in the figure shows a case where hydrostatic air bearings are used both in the vertical and horizontal directions as slide bearings for the feed base. Comparing both A and B, the master rotation speed is 90Or, p,
It can be seen that the vibration mount 11] is suppressed to about one-eighth in m, and it can be seen that the present invention exhibits a remarkable effect in suppressing the vibration caused by the unbalanced rotation of the master. father,
This effect is particularly noticeable when the master rotation speed is low.

However, this measurement was performed without linearly driving the feed table.

Also, regarding stick-slip vibration, its occurrence is as follows.
This was not acceptable at all, and it was possible to obtain extremely high feed accuracy.

In the above embodiment, Teflon was used as the t1 ratio of the resin cord layer, but other resins may be used. Father, regarding the four parts provided in the resin coat layer, 1. Basically, pressurized gas supplied from the outside is stored in the four parts, so that the resin coat layer exists all around the four parts. However, the shape is not limited to the rectangle shown in the embodiment. Also, the number of recesses is one or more.
Two is fine.

Effects of the Invention As described above, the present invention has the guide portion of the slide bearing of the feed base that supports the vertical load made of resin, and a recessed portion provided in the sliding surface, in which pressurized air is introduced. By supplying this material, the contact pressure on the sliding surface is reduced, so it is possible to greatly suppress stick-slip vibrations and vibrations caused by unbalanced rotation of the master, etc., and improve the linear movement flexibility of the feed table. This improves the accuracy of signal recording on the master disc. Also, when using a normal sliding ill+ holder or a rolling 1q11 holder, lubricating oil and grease are used, but when cutting with a laser, the oil mist that evaporates from these lubricating oils prevents normal cutting. Although this is a major problem, the slide + IQI + receiver configuration of the present invention allows operation in a dry state, without the problem of contaminating a clean atmosphere, and without the maintenance tube 33j! It also has the feature of being easy to use.

Furthermore, the mechanical strength of resin sliding surfaces is much lower than that of general mechanical structural materials such as steel, but in the present invention, by significantly reducing the contact surface pressure, its reliability, especially its wear resistance, is improved. also has the effect of soiling the dog [improved by IJ].

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the structure of a tray 1 of a conventional disc recording master production apparatus, FIG. 2 is a cross-sectional view of a feeding mechanism section of a disc recording master production apparatus according to an embodiment of the present invention, and FIG. 3 is a slide bearing section of the same. Figure 4 is a perspective view of the same slide block, Figure 5 is a perspective view of the slide block, Figure 5: Vibration of the feed base! FIG. 6, which is an explanatory diagram of timing, is a graph of the measurement results of the carriage vibration vibration [Feed carriage vibration vibration 11 showing the effect of suppressing IJ] according to the implementation of the present invention. 21... Master disc, 26... Rotating shaft, 26...
...Feeding stand, 27...Put, 28...
Feed screw, 30° 31...Slide guide, 32
．． 33...Slide prick, 35.36.-
...resin coat layer, 37... recess, 38...
・1 part of 1-piece gas discharger. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
figure

Claims (1)

[Claims] It has a rotation drive means and rotatably supports a disc-shaped master disk, a rotation IQl+, a bearing that supports this rotation 11Ql+, a feed stand on which this bearing is mounted, and a feed stand that allows linear motion to be applied to the feed stand. - a slide bearing that supports the cart on the feed platform and guides the curved movement, such as a linear drive means;
Irradiating the master with a laser beam carrying an information signal,
A guide section comprising a means for processing and recording the information signal and supporting the load in the vertical direction of the slide bearing is connected to the top surface of the slide guide fixed to the device base and to the top surface of the slide guide fixed to the feed base. Consists of the bottom surface of the slide block,
The lower surface of the slide block is made of a resin material having one or more four parts on the surface, and the bottom of each of the four parts is provided with an opening for discharging gas. A disc recording master production device configured to introduce into the four parts.