JP3252498B2 - Head cleaner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head cleaner for cleaning seizures and deposits generated on the surface of a magnetic head.

[0002]

2. Description of the Related Art It is important for a magnetic recording and reproducing apparatus to reproduce a signal recorded in a magnetic tape with high reliability.

However, during long running, a part of a magnetic tape component such as a magnetic powder and a binder resin may be detached from the surface of the magnetic tape and adhere to the sliding surface of the magnetic tape of the magnetic head, resulting in a so-called output reduction. In addition, problems such as clogging, dropout, and the like related to electromagnetic conversion characteristics occur.

Conventionally, to solve such technical problems, soft members such as polyester felt, wool felt, non-woven fabric, malt plain (sponge) and deerskin are selected as cleaning members and brought into contact with a magnetic head in an appropriate mode. Japanese Patent Application Laid-Open No. 52-75426 discloses a method which aims to remove the deposits attached to the sliding surface of the magnetic head.
JP-A-56-77921, JP-A-01-1510
12, JP-A-01-290112, JP-A-02-254616, JP-A-03-97111, and JP-A-03-12512. According to these proposals, it is possible to remove the deposits that have adhered to the magnetic head sliding surface with a relatively weak force.

[0005]

However, as will be described later, since the seizure generated when used in a low humidity environment is generated on the sliding surface with a strong bonding force, the seizure cannot be removed. These recommendations limit their scope. The object of the present invention has been made in view of the above-described circumstances, and it is possible to remove not only the adhering substance adhered with a relatively weak force but also the adhering substance firmly bonded to the magnetic head surface, such as a burn-in substance. The purpose is to provide a head cleaner. The burn-in phenomenon described in this specification will be briefly described. Moisture in the atmosphere plays an important role as a lubricating film in the relative movement between the magnetic head rotating at high speed and the magnetic tape. However, in a low-humidity environment with little moisture, the contribution of the moisture in the air to the magnetic tape and the magnetic head running decreases, so the coefficient of friction increases, and the degree of direct contact between the magnetic head and the magnetic tape increases. A substance detached from the magnetic layer serves as a trigger to generate a burned-in substance which cannot be wiped off with a solvent in the sliding portion of the magnetic head.

[0006]

SUMMARY OF THE INVENTION In order to solve the above problems, a head cleaner according to the present invention comprises a roller having a rotating roller.
A first cleaning unit in which a soft member such as a felt, a sponge, and a nonwoven fabric is impregnated with a polymer resin and abrasive particles, and a soft member such as a felt, a sponge, and a nonwoven fabric. 2 is provided on the outer peripheral portion of the rotating roller .

[0007]

According to the head cleaner of the present invention to which such means are applied, when a burn-in product is generated on the sliding surface of the magnetic head, the first cleaning portion containing abrasive particles is brought into contact with the sliding surface of the magnetic head. Thus, burn-in can be removed by the abrasive action of the abrasive particles. In addition, soft particles such as felt, sponge, and non-woven fabric are impregnated with abrasive particles together with the polymer resin, so that the contact with the magnetic head becomes a soft touch and removes seizures without significantly damaging the magnetic head surface. Can be done over a long period.

Further, immediately after the operation of the first cleaning unit, the second cleaning unit can remove wear powder, deposits, and the like remaining on the surface of the magnetic head due to polishing.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing the relationship between the head cleaner of the present invention and the head.

FIG. 2 is an enlarged view of the cleaner cleaning section of FIG. 1 and FIG. 3 is a view of FIG.
FIG. 3 is a cross-sectional view taken along line AA ′ of FIG. 1, showing a first cleaning unit made of a soft member felt containing a polymer resin 3b and abrasive particles 3c, and a second cleaning unit made of a soft member felt containing no abrasive particles. Consisting of (FIG. 1)
In FIG. 3, a first cleaning unit and a second cleaning unit are provided on the same felt sharing the same axis.

1 is a rotary cylinder, 2 is a magnetic head mounted on the cylinder 1, and 3 is a first cleaner.
A cleaning section of a head cleaner comprising a cleaning section and a second cleaning section, 4 is a supporting section for rotatably holding and moving the cleaning section, and 5 is a section for starting and ending the cleaning operation. Sometimes support 4
Indicates the moving direction.

Reference numeral 3a denotes a first cleaning section, which is made of a soft member felt containing a polymer resin 3b and abrasive particles 3c. Reference numeral 3d denotes a second cleaning unit, which is made of a soft felt that does not include the abrasive particles 3c. Reference numeral 3e denotes a rotator arranged to hold and rotate felt used in the first cleaning unit and the second cleaning unit.

When the surface of the magnetic head burns and the performance related to the electromagnetic conversion characteristics changes, the cleaning operation is performed for a necessary time by detecting these changes.

The construction of the first cleaning unit and the second cleaning unit will be described with reference to FIG. The felt of the soft member is immersed in the mixed liquid 6, that is, the mixed liquid 6 to which a hardener, an antistatic agent, a dispersant, and a lubricant are added as required in addition to the polymer resin, the abrasive particles, and the solvent, for a predetermined time. The diameter of the cylindrical felt is d, and the depth at which the felt is immersed in the mixed liquid 6 is h (of course, h holds the relation of h <d).
Then, the part immersed in the mixed liquid 6 is configured as a first cleaning unit, and the part not immersed is configured as a second cleaning unit.

The depth h is an important variable related to the polishing effect of the first cleaning unit, and also relates to the specification of the VTR to be applied.

The mixed liquid 6 is sufficiently mixed and dispersed by a mixer,
A raw material liquid is prepared so as to have a desired component ratio. As the mixer, a ball mill, a sand mill, a dissolver, an attritor, a high-speed mixer, a kneader, a Henschel mill, a planetarium mixer, or the like may be used.

As the polymer resin, nitrocellulose,
Fibrous resins such as cellulose acetyl butyrate, vinyl chloride vinyl acetate copolymer resin, vinylidene chloride resin, polyurethane resin, polyamide resin, urea resin,
One or a combination of two or more of epoxy resin, polyester resin, fluorine resin, acrylonitrile resin, phenol resin and the like and derivatives of these resins are used in consideration of dispersibility.

Examples of the curing agent include low molecular weight isocyanate, polyamine, polyamide and the like. Organic solvents include methyl ethyl ketone, methyl isobutyl ketone, toluene, cyclohexanone, ethyl acetate, THF, DMF,
Isopropyl alcohol and the like.

As the antistatic agent, carbon black,
There are graphite particles. Higher fatty acids as dispersants,
There are metal salts of higher fatty acids, higher fatty acid amides, higher alcohols, phosphate esters, glycerin, silane coupling agents, titanium coupling agents, and the like, which are added as needed.

As the soft member, sponge, non-woven fabric, deerskin, wool, etc. are desirable other than felt. Moreover, it is desirable that the soft member does not lose its softness even after being impregnated with the polymer resin and abrasive particles in the soft member and undergoing the heat history process. In order to uniformly contact the magnetic head for a long period of time, a cylindrical shape is desirable.

Examples of the felt include polyesters such as polyethylene terephthalate and polyethylene 2, 6-naphthalol, polyolefins such as polyethylene and polypropylene, cellulose acetate, cellulose diacetate, cellulose acetate butyrate, cellulose derivatives of cellulose acetate propylate, and the like. Examples include vinyl resin-based polycarbonates such as vinyl chloride and polyvinylidene chloride, and plastics such as polyimide, polyetherimide, and polyamideimide.

As the non-woven fabric, polyester, nylon,
Crimped nylon, acrylic, vinylon, rayon, cotton and the like can be mentioned.

As the abrasive particles, α-alumina (Al
₂ O ₃ ), titanium oxide (TiO ₂ ), red iron (Fe ₂
O ₃ ), chromium oxide (Cr ₂ O ₃ ), silicon carbide (Si
C), silicon dioxide (SiO ₂ ) or the like is used.

As the lubricant, fatty acids, fatty acid esters,
Perfluorocarboxylic acid, perfluoropolyether and the like can be mentioned.

As a method of forming the cleaning section, there is a method in which the first cleaning section and the second cleaning section are separately formed and then bonded with an adhesive. This method is also a method that is well suited to the present invention. A more detailed example will be described below.

(Embodiment 1) The outer diameter is 10 mm and the inner diameter is 5 m
m, the length of the cylinder is 15 mm, and the felt 3 made of polyester is immersed in a mixed solution 6 in which alumina particles and a urethane resin are dispersed in a solvent, and the alumina particles and the urethane resin are impregnated in the felt. . The mixing ratio of alumina, urethane resin and solvent used at this time was as follows by weight.

Α-alumina: 10 parts Polyurethane: 1 part Solvent: cyclohexane: 30 parts Toluene: 60 parts Methyl ethyl ketone: 90 parts After putting such a mixture 6 into 3 g of a container, As shown in FIG. 4), the felt was immersed in the liquid with the length of the felt parallel to the liquid surface. The first cleaning unit was configured with the depth h at which the felt was immersed in the liquid as a variable. afterwards,
It was left at a temperature of 60 ° C. for 12 hours to accelerate the curing reaction. Then, the magnetic tape was repeatedly run in a magnetic recording / reproducing apparatus in which the felt was attached to the rotating tool 3e described above.

As the magnetic tape, a 120-minute long magnetic tape made of a metal magnetic powder type was selected. I chose H.

The test was repeated 100 times while examining the behavior of the reproduction output at a recording wavelength of 0.7 μm. The magnetic head used for the test had a magnetic core made of metal. The rotating roller supporting base 4 supporting the cleaning unit 3 is intermittently energized to a solenoid (not shown in FIG. 1) connected to the rotating roller 4 and provided with a timer (omitted in FIG. 1). It is moved intermittently near the magnetic head. Then, the contact between the cleaning unit 3 and the magnetic head 2 is performed for a certain period of time.
The time mode performed in the first embodiment, that is, the contact time between the cleaning member 3 and the magnetic head 2 in the cylinder, that is, the operation time is taken as a parameter, and the time when the cleaning unit 3 is not in contact with the magnetic head 2, that is, 30 downtime
You are running repeatedly with a selection of minutes. The mode is
It is determined by the concentration of the polymer resin and the abrasive particles in the cleaning section 3 and their materials, the pressing pressure applied to the magnetic head 2 by the cleaning section 3, the temperature, the humidity, and the like.

Table 1 summarizes the results of these repeated running tests.

[0032]

[Table 1]

The comparative example in Table 1 shows a conventional cleaning mechanism. That is, the cleaning operation involves only the wiping operation.

The output in Table 1 is the output after 100 passes of running, with the output at the start of the repetitive running test in a low humidity environment as the reference output. The presence or absence of burn-in is shown as an observation result by an optical microscope after 100 passes. The magnification in observation with the optical microscope was 200 times.

The clogging in Table 1 indicates the total clogging time caused by the total running time of the magnetic tape. The term “dropout” refers to the number of signal drops per minute with a time length of 15 μsec or less and a decrease in output of −16 dB or less.

From the results of (Table 1) in (Example 1), the cleaning section is composed of only the felt impregnated with the alumina particles and the urethane resin, that is, in the case of h> 10, compared with (Comparative Example 1), there is no sticking. In addition to suppressing the occurrence, there are some improvements in clogging and dropout.

When h is changed, that is, when the first cleaning unit and the second cleaning unit are simultaneously arranged on the felt portion, clogging and dropout can be further improved.

[0038]

[0039]

[0040]

[0041]

It should be noted that the first cleaning unit and the second cleaning unit are provided with a mechanism movable in the cylinder axis direction, and the operation is performed using the clean surfaces of these cleaning units that come into contact with the magnetic head. Although not particularly mentioned in the examples, it is obvious that it is necessary to continuously exert the purpose of the present invention.

[0043]

According to the present invention, it is possible to remove the seizure generated on the sliding surface of the magnetic head in a specific environment or to prevent the generation of the seizure beforehand, so that the output is reduced due to the occurrence of the seizure. In addition, occurrence of clogging can be remarkably improved over a long period of running.

[Brief description of the drawings]

FIG. 1 is a perspective view mainly illustrating a cylinder and a cleaning mechanism of a magnetic recording / reproducing apparatus used in an embodiment of the present invention.

FIG. 2 is an enlarged view of a cleaning unit in FIG. 1;

FIG. 3 is a schematic sectional view of a first cleaning unit and a second cleaning unit in (FIG. 2).

FIG. 4 is a diagram showing a configuration method of a first cleaning unit and a second cleaning unit of the present invention.

[Explanation of symbols]

 Reference Signs List 1 rotating cylinder 2 rotating head 3 rotating roller including cleaning unit 3a first cleaning unit 3b polymer resin 3c abrasive particles 3d second cleaning unit 3e rotating tool 3g container 4 rotating roller support unit 5 moving direction at the time of cleaning operation 6 mixed solution

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Masaya Sakaguchi 1006 Kazuma Kadoma, Kadoma City, Osaka Inside Matsushita Electric Industrial Co., Ltd. (56) References JP-A-4-205809 (JP, A) 81867 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B 5/41

Claims (1)

(57) [Claims] A rotary row rotatable about an axis.
A roller head cleaner with La, full E Le <br/> DOO, sponges, and the first cleaning portion to the soft member that is selected from any of the non-woven fabric impregnated with abrasive particles and polymer resin A second cleaning unit composed of only the soft member is provided on an outer peripheral portion of the rotating roller.
A head cleaner characterized by the fact that: