JPS6350781B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field] The present invention relates to a magnetic recording and reproducing device used in a video tape recorder (hereinafter abbreviated as VTR) and the like. [Prior Art] In recent years, the technology related to magnetic recording and reproducing devices has made remarkable progress, and the development of VTR technology is particularly remarkable. In this situation, the current VTR system is
VHS method, β method, V-2000 method or CVC
Various incompatible systems coexist and are widespread. This has led to inconvenient problems such as confusion on the part of users. Against the background described above, the so-called 8mm VTR is being developed as a next-generation model.
Regarding this, complete standardization has been achieved among manufacturers. The magnetic tape applied to this 8mm VTR is a metal tape or a vapor-deposited tape.
When metal tape is used, if the magnetic tape (hereinafter simply referred to as tape) running system is constructed in the same way as that used in conventional VTRs, the wear of various parts of the tape running system will be significant due to the metal tape. Become. On the other hand, when a vapor-deposited tape with a thin film thickness and relatively low mechanical strength is used, various other problems arise. In other words, if you construct a tape running system in the same way as before, using a fixed post made of stainless steel or a rotating drum made of aluminum, and setting the tape wrapping angle to 210 degrees with respect to the rotating drum with a diameter of φ = 40 mm, the tape will be fixed. Problems such as sticking to the post or the circumferential surface of the rotating drum, or increasing the coefficient of friction between the tape and the fixed post or the circumferential surface of the rotating drum, cause uneven tape running speed, resulting in degraded reproduced images. . Such problems become particularly noticeable when the device is used in a humid atmosphere. This type of problem in a humid atmosphere is also disclosed in Japanese Patent Laid-Open No. 58-98868 as a general problem of VTRs, and a tentative solution is also presented. This is applied to the surface of the tape running member as a higher fatty acid such as stearic acid, as a higher fatty acid salt such as zinc stearate, as a higher fatty acid amide such as stearic acid amide, as a reactive organic amide such as a silane coupling agent, or as a reactive organic titanium salt. For example, a substance such as an organic titanate ester is dissolved in a solvent, and the concentration is 1.
After immersing the above-mentioned member in a treatment liquid adjusted to about % by weight, drying with high-speed hot air forms a thin film layer made of the above-mentioned substance on the surface of the above-mentioned member,
The above member is made to have water repellency. However, the thin film layer produced by the method disclosed above cannot withstand wear caused by running the tape for a long period of time and is therefore impractical. Also, unlike coated tapes, which combine magnetic powder with a binder and release an oil lubricant from the binder, the tape surface is simply coated with an oil lubricant, so this oil lubricant is released as the tape runs. Easy to remove due to wear. As a result, the contact between the tape and the drum or post deteriorates, and the tape and the drum are likely to scratch each other, which has the disadvantage of adversely affecting tape recording or tape running. [Objective] The object of the present invention is that even when using a magnetic tape that is difficult to run, such as a vapor-deposited tape, the coefficient of friction in the tape running system is small, and the tape running speed becomes uneven and the tape runs smoothly. The tape does not stick to the running system components, there is little damage to the tape, and the tape has good running characteristics as mentioned above even in a humid atmosphere. It is an object of the present invention to provide a magnetic recording and reproducing device in which damage to a tape running system can be suppressed even when a magnetic tape that has a large abrasion effect is used. [Summary] In order to achieve the above object, the present invention is characterized by the following configuration. That is, among the members constituting the magnetic tape running system, at least the magnetic tape sliding contact surface of a predetermined member such as an aluminum drum is first coated with a titanium layer on the base material of the predetermined member, and then coated with a titanium layer. It is characterized in that it is formed by stacking a plurality of titanium nitride layers and titanium layers in an alternating relationship. [Embodiment] FIG. 1 is a system diagram showing a tape running system in an embodiment of the present invention. In FIG. 1, tape 10 emerges from supply reel 12 in cassette 11 and takes the following path. Cassette inner post 13 → Cassette inner post 14
→ Tension post 15 → Rotating roller 16 → Inclined post 17 → Rotating roller 18 → Tape leader 19
→ Full width erase head 20 → Tape guide 21 → Drum 22 → Slanted post 23 → Audio erase head 24 → Audio control 25 → Post 26
→ Capstan 27 and pinch roller 28 → Inner cassette post 29 → Inner cassette post 30. The tape 10 passes through the above route and is delivered to the take-up reel 3.
This will lead to 1. Among the members in the tape running system described above, the drum 22 is made of aluminum as a base material, and the outer peripheral surface (tape sliding surface) of the base material is first coated with a titanium (Ti) layer, and then titanium nitride (titanium nitride) is coated on that. It has a thin layer formed by stacking a plurality of TiN (TiN) layers and Ti layers in an alternating relationship. To form these thin layers, it is preferable to apply a method of depositing the above-mentioned substance on the surface of the base material by a physical vapor deposition method (hereinafter abbreviated as PVD method) or a chemical vapor deposition method (hereinafter abbreviated as CVD method). According to experiments conducted by the inventors, it has been confirmed that the TiN thin layer formed by applying the PVD method has a Vickers hardness (HV) of about 2000 or more. Among the PVD methods, ion plating is considered to be the best in terms of film properties and productivity. Also, TiN seems to be the best choice for surface film formation, depending on the strength of the film and the conditions of creation. In the case of the aluminum material used for the drum, if the temperature exceeds 300℃, it will deform due to the thermal deformation property of aluminum.
This is because TiN requires surface treatment at a temperature of approximately 400°C, whereas TiN can be treated at temperatures below 300°C. Figures 2a and 2b are a plan view and a side view of the drum 22. The drum 22 is composed of an upper drum (a rotating drum in this embodiment) 41 and a lower drum 42 (a fixed drum in this embodiment). The upper drum 41 is fixed to a shaft 43 and rotates together with the shaft 43. The upper drum 41 also has a pair of magnetic heads 44,
45 are provided at 180° different positions as shown. Further, a tape guide 46 is provided on the lower drum 42, and a magnetic tape (not shown) runs along this tape guide 46. FIG. 2c is an enlarged view of section F in FIG. 2a. That is, a Ti layer 47a is formed on the surface of the drum 22 by ion plating, and the Ti layer 47a is formed on the surface of the drum 22 by ion plating.
On the layer 47a, a TiN layer 48a, a Ti layer 47b, a TiN layer 48b are also formed by ion plating.
are formed alternately. FIG. 3 is a schematic diagram showing the configuration of an ion plating apparatus for carrying out the above-mentioned ion plating. Reference numeral 51 in the figure is a bell gear, and within this bell gear 51, a sample mount 53 on which a sample 52 is mounted in a skewer shape is rotated in the direction of an arrow 53a in the figure by a rotation mechanism that rotates with power from a motor 54. It revolves in the direction of the middle arrow 53b. Further, a negative voltage is applied to the sample mount 53 by a base voltage power source 55, so that the sample 52 is negatively charged. In the figure, reference numeral 56 denotes an evaporation source containing Ti, and Ti is evaporated by applying a beam from a beam device 57. In addition, the evaporation source 5
An ionization electrode 59 to which a positive voltage is applied by an ionization power source 58 is provided above the ionization electrode 6.
This electrode 59 connects the evaporation source 56 and the ionization electrode 5.
8 becomes a plasma state, and the evaporated Ti is ionized. The ionized Ti is accelerated toward the sample mount 53, collides with the sample 52 with high kinetic energy, and forms a Ti layer. After this, the reaction gas N ₂ is supplied from the gas system 60.
If you supply _N2 gas, it becomes a plasma state,
The sample 5 is accelerated toward the sample mounting table 53.
2, a TiN film is formed. The above ion plating equipment forms Ti layers with various thicknesses on an aluminum drum.
When we investigated the relationship between peeling and formation of the film, we obtained the results shown in the following table.

[Table] As is clear from the above table, when the Ti layer is 1 μm or more, the adhesion between the aluminum material and the Ti layer becomes better. Meanwhile, a 0.5μ TiN layer is directly placed on the aluminum material.
It was confirmed that if aluminum and TiN are formed, cracks may occur in the TiN layer, which may impede tape running, since the coefficients of linear expansion are significantly different between aluminum and TiN. Therefore, as shown in Fig. 4a, the aluminum material 6
Coat a Ti layer 62a of 1 μm on top of 1, and
TiN layer 63a is 0.2 μm, Ti layer 62b is 0.2 μm,
When TiN layers 63b of 0.5 μm thickness were alternately stacked, no cracks occurred. In addition, as shown in FIG. 4b, the Ti layer 62a is 0.2 μm thick, and the TiN layer 63a is 0.2 μm thick.
m, Ti layer 62b 0.2 μm, TiN layer 63b 0.2 μm
No cracks occurred even when laminated to a thickness of . In addition, since the drum is made of aluminum, both die-gusting and forging are considered for manufacturing the drum, but when ion plating TiN,
According to the experiments conducted by the inventors, it was found that a film of better quality could be obtained by forging than by die-casting. Maximum unevenness on the surface of aluminum material is 1.5μm, 1μm
Three types were made, 0.5 μm and 0.5 μm, and the surface was coated with a TiN layer. The 0.5 μm type had the best surface condition, followed by 1 μm and 1.5 μm. In other words, the smaller the maximum surface unevenness, the better the quality of the film obtained. On the other hand, when making a drum using die-casting, it is impossible to eliminate defects. Defects cause cracks and interfere with tape running. Also, if you coat the large mandible with TiN,
The mandible part becomes the vacuole. This vacuole has TiN
A huge crystal is formed and this crystal scratches the tape. The same thing can happen with forged drums, but not as much as with diegasts. Thus, forging should be used as the manufacturing method for aluminum drums when ion plating TiN. FIG. 5 is a system diagram showing a measurement system for measuring the coefficient of friction in the tape running system of this apparatus. In FIG. 5, the magnetic tape 100 is arranged as follows: supply reel 101 → fixed post 102 → guide roller 1
03 → Fixed post 104 → Tension analyzer post 105 → Sample (drum or post) 20
0 → Tension analyzer post 106 → Fixed post 107 → Capstan 108 and pinch roller 109 → Guide roller 110 → Fixed post 1
They are stretched in the order of 11→take-up reel 112. Tension analyzers 121 and 122 each have a tension gauge corresponding to the tension analyzer posts 105 and 106, respectively.
are connected, and these tension analyzers 12
1 and 122 have signal conversion circuits 131 and 1, respectively.
32 are connected. Each signal conversion circuit 131,
The output of 132 is input to an arithmetic circuit 140. The distance between the tension analyzer posts 105 and 106 can be changed to be wider or narrower, so that the angle at which the tape 100 is wrapped around the sample 200 can be changed. To measure the friction coefficient μ of the sample 200 using the measurement system shown in FIG. 5, the capstan 108 is driven to rotate, and the tape 100 sandwiched between the capstan 108 and the pinch roller 109 is run at a predetermined angle.
A tension analyzer 121 detects the tension T1 of the tape on the side facing the sample 200, and a tension analyzer 122 detects the tension T2 of the tape on the side moving away from the sample 200. Then, through the signal conversion circuits 131, 132 and the arithmetic circuit 140, the following calculation is performed: μ=1n(T2/T1)/θ (θ is the tape winding angle) to obtain the value of the friction coefficient μ. Friction coefficient μ under given temperature and humidity conditions
When measuring , the measurement system shown in Fig. 5 is placed in a constant temperature and humidity chamber. FIGS. 6a and 6b and FIGS. 7a and 7b respectively show the results of measuring the friction coefficient μ of the circumferential surface of a drum as a sample using the measuring system shown in FIG. 5 and recording the results on a recorder. In each figure, the horizontal axis is the time axis, and the vertical axis corresponds to the friction coefficient μ.
The measurement conditions and general indication values in each figure are summarized in the table below. However, in each of the above measurements, the thickness of the magnetic tape was approximately 10 μm,
A vapor deposition tape (CoNi vapor deposited on a base) with a width of 8 mm was applied. Note that the portion indicated by A in FIG. 7b occurs when there are minute holes on the surface of the aluminum drum.

〔Effect of the invention〕

According to the present invention, even when a type of tape that is thin and easily sticks to the tape running system, such as vapor-deposited tape, is applied, sticking does not occur, the coefficient of friction of the tape running system is small, and good running characteristics are ensured. be done. Also, regardless of the type of tape applied,
Since there is little friction in the tape running system, there is little wear on the tape, and there is also very little wear on the tape running system itself. Further, even in a humid atmosphere, the tape does not stick, and the tape running system maintains an ideal state with a small coefficient of friction. Also, by using a forging method to manufacture the drum, a high quality TiN film can be obtained. Furthermore, in the present invention, a Ti layer is coated on the aluminum layer, and a plurality of TiN layers and Ti layers are laminated alternately on top of the Ti layer, so the adhesion strength of the coat layer to the aluminum layer is increased, and the thickness of the coat layer can be reduced. This has the effect that cracks are less likely to occur.

[Brief explanation of the drawing]

Fig. 1 is a system diagram showing a tape running system according to an embodiment of the present invention, Fig. 2 a, b, and c are plan views of a drum;
3 is a schematic diagram showing the configuration of the ion plating device, FIG. 4 a and b are diagrams for explaining the layer structure, and FIG. 5 is a diagram showing the tape running system of this device A system diagram showing a measurement system for measuring the friction coefficient, Fig. 6 a, b, and Fig. 7 a, b are diagrams showing the results of recording the friction coefficient measured by the measurement system of Fig. 5 on a recorder, respectively. be. 10,100...magnetic tape, 13,14,2
9, 30... Post in cassette, 15... Tension post, 17, 23... Inclined post, 22... Drum, 26... Post, 47a, 47b, 62a, 6
2b...Ti layer, 48a, 48b, 63a, 63b
...TiN layer, 105,106...Tension analyzer post, 121,122...Tension analyzer, 131,132...Signal conversion circuit, 140...
Arithmetic circuit, 200...sample.

Claims (1)

[Scope of Claims] 1. In a magnetic recording and reproducing device having a magnetic tape running system extending from a tape supply side to a tape winding side, a predetermined member made of aluminum as a base material among the members constituting the magnetic tape running system. At least the magnetic tape sliding contact surface is a thin layer formed by first coating the base material of the predetermined member with a titanium layer, and then laminating a plurality of titanium nitride layers and titanium layers alternately on top of the titanium layer. A magnetic recording/reproducing device characterized in that it has the following features. 2. The magnetic recording and reproducing apparatus according to claim 1, wherein the predetermined member is an aluminum drum on which the magnetic tape is wound and run over a predetermined winding angle. 3. The magnetic recording/reproducing device according to claim 1, wherein the thin layer is formed by coating the base material using an ion plating method.