JPS6043562B2 - Cutting recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a signal cutting and recording device for sequentially cutting and recording a high frequency signal such as a video signal on a disc-shaped recording medium as mechanical irregularities.

FIG. 1 shows the structure of a cantilever used in a cutting head mounted on a conventional cutting machine for producing master discs of audio records.

Made of metal with relatively low mass and high rigidity.

The resulting cantilever 1 has a fulcrum portion 3 between it and the fixed main body portion 2, and a cutting needle 4 at the other end. Further, at a portion relatively close to the cutting needle 4, the cantilever 1 is connected to a pair of voice coil structures 6a and 6b by a pair of connecting rods 5a and 5b. The voice coil structures 6a and 6b each have permanent magnets 7a and 7b fixed to the device side in the coaxial direction. When the audio signal to be recorded is applied to the voice coil structures 6a and 6b, the magnetism generated causes the permanent magnet 7 to
a and 7b, and move relative to the fixed permanent magnets 7a and 7b, and the movement is transmitted to the cantilever 1 via the connecting cups 5a and 5b. , and further transmitted to the cutting slope 4. Therefore, the tip 8 of the cutting needle moves on a spherical surface whose center is the fulcrum 3 and whose radius is the distance between the fulcrum 3 and the cutting tip 8 in accordance with the audio signal input to be recorded. With such a conventional signal cutting and recording device as it is, it is difficult to perform high-density recording, such as on a video disk master for recording video signals. That is, currently known T
The video disc called ED system has an outer diameter of 21C77Z.
The signal recorded on the disc with a groove pitch of 3.5 μm is 18
00, rotated by p, m, and reproduced the image and sound of one scene. A lacquer disk is used as the recording medium that is the master of this disk, and its surface has irregularities of several tens of micrometers. When the master is rotated at 1800 p and m, this unevenness generally becomes a surface vibration of the recording medium surface mainly composed of 30H2. In response to this surface vibration, the guntile lever used in the audio cutting machine described above has coils, 6a, 6b, connecting rod 5a,
5b etc. is too large to follow. Therefore, the cutting needle makes a deep cut in the convex portions, and shallow cuts in the concave portions, causing the problem that the groove width is not constant. For this reason, it has been considered to keep the running position of the cutting needle 4 approximately constant with respect to the reference plane and cut the entire surface of the recording medium 8, thereby making the width of the kerf constant. However, this cross-sectional view along the kerf in Figure 2A,
When the cutting needle 4 cuts a substantially convex portion on the surface of the recording medium 8, as shown in FIG. 3A, a cross-sectional view taken in a direction perpendicular to the kerf at the mouth (in the case of FIG. 2A and FIG. 3A), ), when cutting a substantially concave part (Fig. 2 and Fig. 3), chips 9 are generated with a larger cross-sectional area than the openings in Figure 2 and Figure 3. The recesses generate chips 9 with a small cross-sectional area. According to the production method, at all times,
The cross-sectional area of chips changes depending on the surface of the recording medium, and stable cutting cannot be obtained, especially when recording at high speeds such as real-time recording. The holding of the cutting needle 4 easily comes off due to the application of force, and the size of the chips is not uniform, and there are disadvantages in that the cutting needles 4 are tangled with chips, and the chips are interrupted. As a solution to these problems, the above-mentioned video disc called the TED system has a speed of 1800 r'. P. In order to produce a master disc that can be played in 1 minute at m, deceleration recording of 1110 to 1125 is performed.

In other words, in the case of 1115 speed, the number of revolutions when recording the master disc is 12
0r'. P. m. The signal to be recorded is also recorded using a storage device, with the frequency lowered to 1115. Therefore, the time required for recording is multiplied by 15 times, and it takes 15 gin to produce a master disc for one-shot playback. It becomes a vibration, 1800 r. p. m. Compared to the main component of plane vibration of Yanghe rotated by 30Hz! Since the frequency is low, an audio cutting machine with a relatively large inertial mass can be used.

However, a problem arises in that recording cannot be performed in real time.

The present invention provides a means for solving these problems, and embodiments thereof will be described below with reference to the drawings. FIG. 4 is a perspective view of the signal cutting and recording device according to the present invention.

In FIG. 4, an elastic plate 10 serving as a cantilever made of a low-density elastic material such as beryllium, resin containing glass fiber, or carbon fiber is fixed at one end to a fixed part 11, and has a free end 12 made of diamond. It has a cutting needle 13. FIG. 5 is a partially enlarged view of the vicinity of the cutting needle 13 in FIG. 4, showing the state of cutting records. The cutting needle 13 is bonded to one electrode surface 16 of a piezoelectric ceramic 15 that vibrates in a direction T perpendicular to the surface of the recording medium 14 . On the other hand, the other electrode surface Jl7 of the piezoelectric ceramic 15 is bonded to a base portion 18 having a suitably large mass and serving as a fixed end for vibrations generated in the piezoelectric ceramic 15. Furthermore, conductive wires 19 and 20 are taken out from the electrode surfaces 16 and 17 in order to generate vibrations in accordance with the signal to be recorded on the piezoelectric ceramic 15. Conductor 1
The electrical signals supplied from 9 and 20 are converted into mechanical vibrations by the piezoelectric ceramic 15, causing the cutting needle 13 to vibrate in the T direction. The recording medium 14 moves in the direction indicated by R, and the cutting needle 13 forms a groove while drawing a signal pattern 21 on the surface of the recording medium 14. At this time, chips 22 are generated on the front surface of the cutting needle 13. The cutting depth of the cutting needle 13 into the recording medium 14 is determined by the pressing force applied to the free end 12 toward the recording medium 14 by the elasticity of the plate material 10 when the fixed part 11 approaches the recording medium 14 in a direction perpendicular to the surface of the recording medium 14. can be generated and deepened.

The plate material 10 operates as a cantilever beam and has a natural resonance.
If necessary, a viscous material 23 such as rubber may be attached to lower the resonance sharpness. Further, the recording board material 10 is configured to have a stiffness in a direction of movement perpendicular to the surface of the recording medium to be smaller than a stiffness in a direction of movement parallel to the surface of the recording medium.

FIG. 6 is a perspective view when recording on a master disc.

The master disk, that is, the recording medium 14 is rotating in the direction of the arrow R'', and the cutting needle 13 attached to the tip of the plate material 10 is generated on the plate material 10 by bringing the fixed part 11 and the recording medium 14 closer together. It is pressed against the surface of the recording medium 14 with a force corresponding to the bending stress, cutting the surface of the recording medium 14 and generating chips 24. The chips 24 are sucked into the intake pipe 25 together with the surrounding air and collected. Further, a blowing pipe 26 is disposed on the opposite side of the cutting needle 13 from the intake pipe 25, and blows out air to assist the collection of chips 24 into the intake pipe 25. 11 is
Since the recording medium 14 is fed at a constant speed in the direction of the arrow S, a spiral groove 27 is formed on the surface of the recording medium 14. Next, the cutting operation of the present invention will be explained in detail.

FIG. 7 is an enlarged view of the tip of the cutting needle 13 during cutting recording according to the present invention. The cutting needle 13 cuts the recording medium 14 at a rake angle α with respect to a plane perpendicular to the surface thereof.
At this time, due to the cutting resistance R, the cutting needle 13 receives a force (2) that pushes it up in the direction along the rake surface. The value of the cutting resistance R increases as the cutting depth d increases and as the rake angle α decreases. Figure 8 A, C]! Furthermore, the cutting recording device according to the present invention has the recesses 30 and the protrusions 3 of the recording medium 4.
FIG.

In FIG. 8A, the plate 10 generates a smaller bending stress than in the opening of FIG. As a result, a smaller pressing force Wa is applied to the cutting needle 14 at the recesses 30 on the surface of the recording medium than at the projections 31 . That is, the pressing force Wb on the convex portion 31 satisfies Wb>Wa. At this time, if the rake angle α of the cutting needle 13 is αa1 in the concave part 30 and αb in the convex part 31, then the relationship is αb>αa, and from FIG.
Then, Vb>Va, and the pressing force Wa, wl) and the pushing force ■A, Vb are in opposite directions, so the cutting needle 13 is effectively Wa-V in the concave portion 30 and Wb-V in the convex portion 31.
A pressing force b is applied to the recording medium 14. Here Wa-Va
By setting the pressing force, rake angle, and depth of cut so that = Wb - Va, a groove of a constant depth can be cut. In other words, the pressing force of the cantilever changes depending on the unevenness of the surface of the recording medium, and the groove width changes.By using a cantilever cantilever, the rake angle is changed to find a balance point, and the groove width is changed. The principle of the present invention is to form a groove in the same direction.
Figure 9 A, Cl]! FIG. 10A is a sectional view taken along the spiral groove when the cantilever according to the present invention is used to manufacture an actual video disk master, and FIG.

As described above, in the present invention, the cantilever that presses the cutting needle against the recording medium is configured so that a larger pressing force is generated in the convex portions of the recording medium than in the concave portions, and the cutting depth d is deep in the convex portions of the recording medium. Then, as explained in FIG. 7, the force that lifts the cutting needle upward increases, and the increase in the pressing force and the increase in the lifting force cancel each other out, so that a constant pressing force always acts on the cutting needle. Therefore, the recording medium 14 has substantially convex portions (see FIGS. 9A and 10B as well as substantially concave portions).
Chips 24 having approximately the same cross-sectional area are also obtained at the opening in FIG. 9 and the opening in FIG. 10.

Therefore, according to the present invention, chips with a substantially constant cross-sectional area can be obtained at all times, so the method of joining a cutting needle and piezoelectric ceramic described later is sufficient even for high-speed chips such as real-time recording, and the chips are also Stable cutting records can be made without cutting and without defects such as chips getting entangled with the cutting needle. FIG. 11 is an enlarged view of the vicinity of the actual cutting needle 13.

Cutting needle 13, piezoelectric ceramic 15, base portion 18, and plate material 10
In order to keep the mutual relationship between the cutting needle 13 and the plate material 10 stable and strong, strong adhesion is performed. As the adhesive 32, for example, an epoxy resin mixed with calcium carbonate, glass fiber, carbon fiber, etc. to improve hardness and strength is used.

In addition, in order to improve the ability to follow unevenness on the surface of the recording medium, the amount of adhesive 32 is kept to the minimum necessary, and the conductive wires 19 and 2 are
0 is also coated with adhesive 32 at the same time to provide electrical insulation when the chips are metal, and to mechanically seal the conductors 19 and 20.
It is also used for the purpose of preventing accidents such as breakage. Further, by coating with this adhesive, the resonance peak of the piezoelectric ceramic 15 can be reduced, and a flatter frequency characteristic can be obtained. 1st
2 and 13 respectively show cantilevers (plate materials) 10 in other embodiments of the present invention.
In the figure, a notch 33 is provided in a part of the plate material 10, and the fixing part 11 is
There are stress concentration parts 10a and 10b in the plate material 10 near the
The stress concentration parts 10a and 10b are actively used as fulcrums.

Furthermore, in the case where the plate material 10 is made of a conductive material, the conductive wire 20 on one side in FIG. You can take it out. FIG. 13 shows that the edges of the plate material 10 are bent into a U-shape to improve the torsional rigidity of the plate material 10 itself.
0 and the fixed part 11 are connected by separate elastic bodies 34 and 35. Such a method is used when the material of the plate material 10 is inappropriate as a bending fulcrum material. As described above, in the present invention, a cutting needle is held at the tip of a cantilever made of substantially elastic material, one end of which is supported by a fixed part, and the cutting needle is attached to the recording medium by the unevenness of the surface of the recording medium. The structure is configured so that the pressing force of the cantilever changes, and the elasticity of the cantilever is adjusted so that the change in the lifting force of the cutting needle and the change in the pressing force are offset according to the unevenness. Since a constant pressing force is always applied to the cutting needle regardless of the unevenness, the depth of the cutting groove made by the cutting needle is constant, and therefore, excessive cutting resistance is not applied to the cutting needle at the convex portion of the recording medium. It is also
The cross section of the chips produced by cutting is constant, and the chips do not cut off and become entangled with the cutting needle, allowing high-speed recording.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing a conventional cutting recording device, Figs. 2 and 3 are sectional views showing the cutting state of the same device, Fig. 4 is a perspective view showing an embodiment of the present invention, and Fig. 5 is a side view of the same main part,
FIG. 6 is a perspective view showing the cutting state, FIG. 7 is an enlarged view of the main part in the same cutting state, and FIG. 8 is a schematic diagram showing the operating state of the present invention.
Figures 9 and 10 are enlarged views of the main parts in the same cutting state, 11
The figure is a side view showing the mounting portion of the cutting needle, and FIGS. 12 and 13 are perspective views showing other embodiments of the present invention. 10... Plate material (cantilever), 11...
- Fixed part, 13... Cutting needle, 14... Recording medium, 15... Piezoelectric element.

Claims (1)

[Claims] 1. An electrical signal is applied to the free end of the cantilever, one end of which is supported by a fixed part, and whose stiffness in the direction of movement perpendicular to the surface of the disk-shaped recording medium that is fixedly and rotationally driven is smaller than that in the direction of movement parallel to the surface of the disk-shaped recording medium. A cutting recording device in which a cutting needle is supported via an electro-mechanical transducer that generates mechanical vibration in response to the vibration, and the cutting needle is elastically pressed against the surface of the recording medium. 2. The cantilever is configured such that the pressing force of the cutting needle on the recording medium changes depending on the unevenness of the surface of the disc-shaped recording medium, and the lifting force of the cutting needle and the pressing force are adjusted according to the unevenness. 2. The cutting recording device according to claim 1, wherein the elasticity of the cantilever is determined so that changes in the cantilever cancel each other out.