CN1086042C - Magnetic recording/reproducing device - Google Patents
Magnetic recording/reproducing device Download PDFInfo
- Publication number
- CN1086042C CN1086042C CN97114050A CN97114050A CN1086042C CN 1086042 C CN1086042 C CN 1086042C CN 97114050 A CN97114050 A CN 97114050A CN 97114050 A CN97114050 A CN 97114050A CN 1086042 C CN1086042 C CN 1086042C
- Authority
- CN
- China
- Prior art keywords
- tape
- drum
- magnetic drum
- magnetic
- rotary head
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Landscapes
- Recording Or Reproducing By Magnetic Means (AREA)
- Magnetic Record Carriers (AREA)
Abstract
To lower the dynamic friction coefft. with a tape and to improve the tape traveling property by allowing skin layer parts and the exposed part of filling parts to coexist on the outer peripheral surface of a stationary and/or rotary drum for sliding with the magnetic tape. The stationary drum 1 is formed by filling fibrous fillers 6, spherical fillers 7 for imparting a sliding characteristic and electrical conductivity to a polymer compd. and microfillers 8 formed by pulverizing these fillers into this compd. and injection molding such compd. Projecting and recessed parts 3, 4 are formed on the surface of the drum 1 and the surface is covered with the skin layer 9. The layer 9 is filled with the fillers in the smaller amt. and is mostly the polymer compd. When the magnetic tape is slid with such drum 1, the projecting parts 3 are worn by the pressure at the time of sliding and turn to the projecting parts 3' and the fillers 6, 7, 8 are exposed on the drum 1 surface. The dynamic friction coefft. with the tape 2 is, therefore, made small after the wear and the good traveling of the tape is assured. In addition, the electrical conductivity is imparted to the outer peripheral surface of the drum 1.
Description
To as an example the prior art relevant with the present invention be described with the magnetic recording/reproducing device that is used in the video tape recorder (VTR) below.
Recently developed magnetic recording/reproducing device, its purpose specifically will obtain higher recording density, the typical typical example of this magnetic recording/reproducing device is video tape recorder in this way, this video recorder is by using a kind of magnetic recording/playing technology to write and read signal on a tape, this video recorder comprises fixedly magnetic drum of a rotary head drum that magnetic head is housed on it and, and these magnetic drums require can guide a tape exactly so that obtain higher recording density.In this respect, along the sliding of the tape of magnetic recording/playing magnetic drum, promptly the friction factor of this magnetic drum and this tape has considerable influence to the guiding accuracy of tape and to the weight saving of tape conveying mechanism.
As everyone knows, magnetic recording/playback drum module comprises fixedly magnetic drum and one rotary head drum that magnetic head is housed on it and can rotates around a central axis.Fixedly magnetic drum has a guide member that forms so that guide a tape exactly on its outer circumference surface.This tape the outer circumference surface of this rotary head drum and fixedly on the outer circumference surface of magnetic drum along this guide member slip.
On the other hand, the requirement that this magnetic recording/reproducing device must satisfy weight reduction and reduce cost, therefore, important problem is to solve the thickness that the makes product attenuate of trying one's best, and reduces the problem of material cost and manufacturing cost.For this reason, many manufacturings have been worked out, specifically with the fixing method of magnetic drum and rotary head drum of resin material manufacturing.With mainly make above-mentioned magnetic drum before this and compare with aluminum alloy materials, resin material is lighter, and can be easy to form the shape of any requirement by injection molding.Therefore, the application of resin material is effective to the part of making complex configuration with low cost.
The magnetic recording/playing drum module that a kind of VTR is arranged, VTR wants by using described magnetic drum module to come record video signal and video replay tracer signal on a tape.
Claim below by a rotary head drum and one fixedly the assembly that constitutes of magnetic drum be magnetic recording/playback drum module, this assembly is mainly by a rotary head drum, a fixing magnetic drum, a magnetic head, an electric rotating machine, a rotary transformer, a plurality of ball bearing, and a central shaft formation.Magnetic drum is formed by injection molding by resin material this rotary head drum with being somebody's turn to do fixedly, or is this rotary head drum, in some cases, can make by the mode of cut with the metal material resemble the aluminium alloy.Resin material is the compound resin that contains the filling agent with desired characteristic.Rotary head drum and fixedly magnetic drum must resemble injection speed, injection temperature, the strictness of the desired condition of molding that injection pressure and mold temperature are such control down on its shape and size the precision with 1/1000mm form.The fixedly magnetic drum of Xing Chenging like this, rotary head drum and other parts should assemble exactly and form the recording/reproducing drum module.
Fixedly magnetic drum has one for guiding the guide member that a tape forms exactly.That is to say, tape can along this rotary head drum and fixedly the outer circumference surface of magnetic drum slide, and guiding by the latter's guide member.The precision of the outer circumference surface of the fixedly magnetic drum that tape slides thereon is that the precision (roughness) by the inside surface that makes the injection-molded metal die that is used for carrying out magnetic drum is determined basically.Particularly as above-mentioned situation.Fixedly the precision of the shape and size of magnetic drum is about 1/1000mm, and therefore, the precision of the working surface of mould must be that same precision is made mirror polish.
Have data we can say bright in the magnetic recording/replay device of described routine the relation between dynamic friction coefficient and the tape sliding time.No matter the sliding time of tape how long, this dynamic friction coefficient all is bigger.Bigger dynamic friction not only can apply excessive load on tape is reeled motor, but also can cause tape to slide inadequately or tremble or damage, and thus, the recording playback signal may degenerate, and in the worst case, tape may not slide.
Japanese patent application publication No. 5-342711 discloses a kind of solution to the problems described above, wherein removes the superficial layer of magnetic drum to improve sliding by the mode of cutting and grinding.But this method need be carried out extra machining (for example cutting is ground and polishing) to the magnetic drum by injection-molded formation: because of the deviation of machining and the relation of clamping stress, machining can influence the size and the configuration precision of magnetic drum.Described extra machining process can make the injecting molded resin magnetic drum and lose with respect to the cost advantage of the magnetic drum that is formed from aluminium by machining.
The present invention relates to a kind of magnetic recording/reproducing device, for example a kind of video recorder (below abbreviate VTR as) and digital recording magnetic tape station (below abbreviate DAT as), this device comprises fixedly magnetic drum of a rotary head drum and, more particularly, the present invention relates to a kind of like this magnetic recording/reproducing device, this device is provided with fixedly a magnetic drum and/or a rotary head drum, each magnetic drum all be make by composite resin material and can allow tape slide stably and reposefully thereon.
Be used to form this rotary head drum and/or fixedly the composite resin material of magnetic drum be a kind of high polymeric compound, this compound comprises glass fibre or carbon fiber, beaded glass or carbon pearl, the whisker of phthalandione potassium etc., inorganic filler (for example, talcum, mica, lime carbonate), and organic filler (for example fragrant acid amides) is used to give host material and resembles physical strength, manufacturing accuracy, sliding, electric conductivity, the necessary performance that electromagnetic wave shielding is such.
The surface coverage that is in just by injection-molded state product after being formed by the resin compound material has so-called top layer, and this top layer is the thin layer that one deck only is made of high polymeric compound.In this top layer, because the possibility that the filling agent composition exists is so little, less than the 1/10-1/20 in the interior section of layered product, so the filling agent composition is difficult to come out on the surface of layered product.
That is to say that the filling agent composition that is added in the high polymeric compound material in order to obtain sliding and electric conductivity can not demonstrate its characteristic fully, because the filling agent composition is covered by high polymeric compound under the state behind the firm molding.Particularly, adopt the tape of the coating contain many high polymeric compounds as bonding agent in its magnetosphere, the material of slip can mainly be the high polymer layer of tape and rotary head drum and the fixing high polymer layer of magnetic drum.Therefore, the contact of the high polymeric compound in each layer of tape will increase, thereby increases physics and chemical viscosity between them, cause tape shear stress increase and cause the increase of the friction factor of these magnetic drums.
Therefore, the purpose of this invention is to provide a kind of simple magnetic recording/reproducing device, wherein, by making the sliding that improves tape in the mode of rotary head drum and/or the fixedly lip-deep filling agent exposure of magnetic drum.
Above-mentioned purpose realizes by the invention provides following measures (1) to (7):
(1) a kind of magnetic recording/reproducing device, this device is provided with the rotary head drum and the fixedly magnetic drum that is used to guide the tape slip that are supporting a playback head, wherein, this rotary head drum and should be fixedly in the magnetic drum at least one be to make with the composite resin material that contains filling agent, and form the single solid magnetic drum that a periphery surface place in the tape operation of this magnetic drum has one first top layer part and one second filling agent expose portion.
(2) a kind of as mentioned magnetic recording/reproducing device of top (1) bar, and it is characterized in that: in those magnetic drums any has uneven configuration on its circumferential surface at least, and the depressed part office at the described circumferential surface of this magnetic drum is formed with first, and is formed with second portion in the lug boss office of the described circumferential surface of this magnetic drum.
(1) and (2) bar in mentioned each magnetic recording/reproducing device facing its rotary head drum and fixedly also having a filling agent expose portion on the circumferential surface of the tape of any at least in the magnetic drum, have less dynamic friction coefficient between this magnetic drum and the tape, thereby make this tape to slide more reposefully along this magnetic drum surface.
(3) a kind of magnetic recording/reproducing device, this device is provided with the rotary head drum and the fixedly magnetic drum that is used to guide a tape slip that are supporting a playback head, it is characterized in that: this rotary head drum and should be fixedly in the magnetic drum any is that usefulness contains that the composite resin material of filling agent is made and forms a single solid magnetic drum with inhomogeneous configuration at least, this inhomogeneous configuration is included in the bossing that faces tape on this circumferential surface, by and tape between the top layer of this bossing of friction will be worn.
(4) the mentioned magnetic recording/reproducing device of (3) bar above a kind of, being further characterized in that of this device: this bossing is than its top layer height that contains.
As top (3) and described each magnetic recording/reproducing device of (4) bar tape guidance surface that all can also have filling agent to expose, this surface can obtain by the mode that a tape that slides thereon wears away the top layer of projection from it, and allows this tape to slide more reposefully with less friction force thereon.
(5) as top (2) to the described magnetic recording/reproducing device of (4) bar, its feature also is: this fixedly magnetic drum have uneven surfaces, from this fixedly magnetic drum the center to the distance of the sunk part of this uneven configuration less than from the center of this rotary head drum to the distance of the tape slidingsurface of this rotary head drum.
Structure recited above can make a tape cling to this tightly fixedly on the guide member of magnetic drum, thereby has improved the degree of accuracy of guiding tape thereon.
(6) as top (2) to (4) described magnetic recording/reproducing device, its feature also is: this fixedly magnetic drum have the guide member that this uneven configuration and are used to guide the slip of a tracks, this fixedly the described uneven configuration of magnetic drum be positioned to the glide direction that is parallel to this tape or tilt towards its guide member.
Structure recited above can make the lateral edges of tape can cling to this tightly fixedly on the guide member of magnetic drum when magnetic track slides, thereby has improved the degree of accuracy of guiding this tape.
(7) as top (2) in (4) each described magnetic recording/reproducing device, its feature also is: this rotary head drum has uneven configuration, this configuration with the direction of the direction of rotation of rotary head drum on the helically setting.
Structure recited above can make the lateral edges of tape cling to this tightly fixedly on the guide member of magnetic drum when tape slides, thereby has improved the degree of accuracy of guiding tape.
Fig. 1 is the view that the structure of the magnetic recording/playing drum module of use in video tape recorder is shown.
Fig. 2 illustrates the conventional fixedly magnetic drum or the curve map of dynamic friction coefficient between rotary head drum and the tape and the relation between the tape sliding time.
Fig. 3 is the skeleton view of fixedly magnetic drum that the magnetic recording/reproducing device of the first embodiment of the present invention is shown.
Fig. 4 is the cut-open view of fixedly magnetic drum shown in Figure 3.
Fig. 5 is the cut-open view that the details of fixedly magnetic drum shown in Figure 1 is shown.
Fig. 6 be illustrate tape on fixing magnetic drum, slide after this fixing cut-open view of the details of magnetic drum.
Fig. 7 is the curve map that fixedly magnetic drum shown in Figure 5 and dynamic friction coefficient between the tape and the relation between the tape sliding time are shown.
Fig. 8 illustrates a tape shown in Figure 3, and rotary head drum and one is the view of the relative position of magnetic drum fixedly.
Fig. 9 is a tape shown in Figure 3 after tape slides, and rotary head drum and one is the view of the relative position of magnetic drum fixedly.
Figure 10 is the skeleton view of another example of the fixedly magnetic drum of the first embodiment of the present invention.
Figure 11 is the cut-open view of another example that the fixedly magnetic drum of the first embodiment of the present invention is shown.
Figure 12 is the skeleton view of fixedly magnetic drum that the magnetic recording/reproducing device of the second embodiment of the present invention is shown.
Figure 13 is the cut-open view of fixedly magnetic drum shown in Figure 12.
Figure 14 is the view that the relation between the guide member of bossing and fixedly magnetic drum shown in Figure 12 is shown.
Figure 15 is the curve map that the relation between the sliding time of fixedly magnetic drum shown in Figure 12 and dynamic friction coefficient between the tape and tape is shown.
Figure 16 is the view of another example of the fixedly magnetic drum of the second embodiment of the present invention.
Figure 17 is the skeleton view of structure of rotary head drum that the magnetic recording/reproducing device of the second embodiment of the present invention is shown.
Figure 18 is the cut-open view of rotary head drum shown in Figure 17.
Figure 19 is the curve map that the relation between the sliding time of rotary head drum shown in Figure 17 and dynamic friction coefficient between the tape and tape is shown.
Figure 20 is the skeleton view of another example of the rotary head drum of the third embodiment of the present invention.
Figure 21 is the skeleton view of another example that the rotary head drum of the third embodiment of the present invention is shown.
Before most preferred embodiment of the present invention is described, will be described conduct below to the magnetic recording/reproducing device of prior art to reference of the present invention.
Fig. 1 is the cut-open view that the magnetic recording/playing drum module of VTR is shown, and this VTR prepares to use described drum module recording image signal and playback photologging on tape.
Claim below by a rotary head drum 101 and one fixedly the assembly that constitutes of magnetic drum 102 be magnetic recording/playing drum module 103, this assembly mainly is by a rotary head drum 101, a fixing magnetic drum 102, a magnetic head (not shown), an electric rotating machine (not shown), a rotary transformer (not shown), a plurality of ball bearing (not shown), and central shaft 104 formations.Rotary head drum 101 and fixedly magnetic drum 102 make with resin material by injection-molded, or have only rotary head drum 101 to make with metal material in some cases by machining resemble the aluminium alloy.Resin material is the compound resin that contains the filling agent with desirable characteristic.Rotary head drum 101 and fixedly magnetic drum must on its shape and size, resemble injection speed, injection temperature, the strictness of the desired molding condition that injection pressure and mold temperature are such control is made with the 1/1000mm precision down.The fixedly magnetic drum 102 of Xing Chenging like this, rotary head drum 101 and other part should accurately assemble and form this recording playback drum module 103.
Fixing magnetic drum 102 has the guide member 105 that a tape is accurately guided in a formation.That is to say that tape is along this rotary head drum 101 and be somebody's turn to do the fixedly external peripheral surface slip of magnetic drum 102, and is being guided by the latter's guide member 105.The precision of the external peripheral surface of the fixedly magnetic drum 102 that tape slides thereon roughly is definite by the precision (roughness) of the inside surface of the injection-molded employed metal die of this magnetic drum.Especially as mentioned above such.Fixedly the precision of the shape and size of magnetic drum 102 is about 1/1000mm, and therefore, the precision of the working surface of mould must be with same precision mirror polish in addition.
Fig. 2 is the curve map of the relation between dynamic friction coefficient and the tape sliding time in the magnetic recording/reproducing device of described routine.This dynamic friction coefficient is big and it doesn't matter with the sliding time of tape.This big dynamic friction not only can apply overload on tape is reeled motor, and can cause tape to slide inadequately or shake or damage, thereby makes the recording playback distorted signals, and in the worst case, tape can stop motionless.
Japan publication communique 5-342711 discloses a kind of way that solves above mentioned problem, has wherein removed the top layer of magnetic drum so that improve slidably property by cutting and grinding.But this method requires to carry out to by the extra machining of the magnetic drum of injection molding forming (for example cut, grind and polish): machining may exert an influence because of the deviation of machining and clamping stress size and the configuration precision to magnetic drum.Described extra mechanical processing process can make injection-molded magnetic drum and lose with respect to the cost advantage of the magnetic drum that is formed from aluminium by machining.
Describe below with reference to Fig. 3 to the 11 pair of first embodiment of the present invention:
Shown in this embodiment in, the present invention will be applied to fixedly on the magnetic drum.
Fig. 3 is a fixedly skeleton view of magnetic drum 1, and Fig. 5 is to analyse and observe the synoptic diagram of the fixedly magnetic drum shown in the form.Fixedly magnetic drum 1 is made with resin composite materials by injection-molded.Fixedly magnetic drum 1 is accurately to make with the precision of about 1/1000mm.Particularly, fixedly the circularity of the periphery of the linear degree of the guide member of magnetic drum 1 and this magnetic drum is the important factors of the performance quality of this device of decision.
Be used to make this fixedly the resin composite materials of magnetic drum 1 be high polymeric compound and the potpourri that improves the filling agent composition that resembles sliding, electric conductivity, mouldability and physical strength with excellent mechanical intensity and mouldability.High polymeric compound for example is polyphenylene sulfide (PPS), polycarbonate (PC), polyethersulfone (PES), polyetheretherketone (PEEK), liquid crystal polymer (LCP), the potpourri of inferior acid amides (PEI) of polyethers or described superpolymer (comprising compound).Filler material can be used for and fiber (for example glass fibre, carbon fiber, phthalandione potassium whisker), globule (glass bead, the carbon globule), spherolite, particle, powder or diaphragm (carbon, carbon black, talcum, mica) in more any combination, in them, very little and conductive filler that have very little length breadth ratio and spherical, granular, pulverous and amorphous filling agent are for the dimensional accuracy of improving described magnetic drum and the material that sliding is particular importance.
Make fixedly magnetic drum 1 by the precise injection molding with above-mentioned resin.Like that, fixedly magnetic drum 1 has the circumferential surface that dimpling portion 3 and a nick portion 4 and a guide member 2 are arranged on its xsect shown in Fig. 3 and 4.This dimpling portion 3 be zigzag microspike tooth as shown in Figure 4.This configuration of this magnetic drum is to use inner wall surface thereof to be formed with accurately by sand-blast that the injection molding of small unevenness forms.Say nothing of and also can use other suitable methods.Height difference H between dimpling portion 3 and the nick portion 4 is set at the numerical value greater than thickness that will be by the top layer that forms on the surface that is injection molded in product.And, the upper limit of this difference in height numerical value preferably should be about three times of skin depth, its reason is if difference in height has surpassed three times of skin depth, and the moulding resin magnetic drum is not easy to throw off with molding tool because of the mutual relationship between the external diameter of the mold shrinkage of high performance composite resin material and magnetic drum.If fixedly the surface of magnetic drum is uneven highly above three times of skin depth, then still can obtain the same effect that reduces of the fixing dynamic friction between the magnetic drum and tape.
Fig. 5 is the fixing cross sectional detail of the adjacent part of the outer surface region of magnetic drum 1, this magnetic drum is by using above mentioned metal die to pass through fiber filling agent 6, spherical filling agent 7, the injection-molded formation of the high polymeric compound that the filling agent 8 of granular filling agent (not shown) and its fine gtinding mixes.
As shown in Figure 5, this magnetic drum has the little serrate circumferential surface that has dimpling portion 3 and nick portion 4.This adjacent part on the surface of this magnetic drum is covered by one deck top layer 9, and this top layer is almost to be to be made of the high polymeric compound that has very small amount of filling agent 6,7 and 8.The possibility that has filler material in top layer 9 is less than 1/10 to 1/20 of the filler material in the inside part of fixing magnetic drum.
Fig. 6 is the cross sectional detail of fixedly magnetic drum shown in Figure 3 adjacent part of its surf zone after tape slides thereon.Like that, dimpling portion 3 shown in Figure 5 has worn away (for example the dimpling portion 3 among Fig. 6 ') by the strong pressure that produces at tape when sliding shown in Fig. 3 and 4.Therefore, add in the high polymeric compound material so that provide the filling agent 8 of the fine gtinding of lower rubbing characteristics and electric conductivity, fiber filling agent 6, spherical filling agent 7 and particles filled dose just fixedly come out on the surface of the wearing and tearing of magnetic drum at this, therefore this fixedly magnetic drum can play an important role aspect the sliding of tape improving.Exposing at most in the above mentioned filling agent a kind of is the filling agent 8 of fine gtinding.
Fig. 7 is that tape is along the sliding time of fixedly magnetic drum slip shown in Figure 5 and the curve map of the relation between their dynamic friction coefficients between the two.This curve map shows dynamic friction coefficient and directly sharply reduces (comparing with the situation of routine shown in Figure 2) along with the sliding time of tape.This can be worn by dimpling portion 3 and expose filling agent 6,7 and 8 such facts make an explanation.Like this, dynamic friction coefficient just can reduce significantly because fixedly the surface in contact between magnetic drum and the tape increased and make convex surfaces further wearing and tearing stop.
In the above-described embodiments, should be fixedly magnetic drum be formed with uneven external peripheral surface by composite resin material injection-molded, and should be fixedly the dimpling portion 3 of magnetic drum wear away their tip by the tape of slip thereon and expose the filling agent 8 of the fine gtinding in the dimpling portion of fixing magnetic drum 1, fiber filling agent 6, spherical filling agent 7 and particles filled dose.Therefore, this has fixedly reduced with dynamic friction coefficient of tape on magnetic drum 1 its surface after wearing away dimpling portion tip.That is to say, this fixedly magnetic drum tape can suitably be slided thereon.In addition, fixedly the circumferential surface of magnetic drum 1 can have electric conductivity.
Want the external diameter of the little fixedly magnetic drum that causes to dimpling portion 3 and the variation of circularity can not surpass the dimpling portion surface 3 of wearing and tearing and the difference in height between the nick portion surface 4 in the difference in height between dimpling portion (tip) surface and nick portion (bottom) surface 4 by wearing and tearing.This means that fixedly magnetic drum can keep the necessary accuracy of its configuration and size.
Fig. 8 shows the fixedly magnetic drum 1 among this embodiment of the present invention, rotary head drum 19 and tape.In such cases, fixedly the external diameter of the depressed part 4 of magnetic drum 1 is slightly less than the external diameter of rotary head drum 19.Fixedly the points wear of the dimpling portion 3 of magnetic drum 1 is to height shown in Figure 9, that is, fixedly the external diameter of the tape slipper of magnetic drum 1 becomes littler than the external diameter of rotation magnetic drum 19.Tape 10 can slide on its lateral edges place is pressed over the guide member 2 of fixing magnetic drum securely.Like this, just can improve the precision of guiding tape 10.
Fixedly the lug boss 3 of magnetic drum 1 is preferably formed as cylindrical shape or rhombus, because they have the profile of rectangular section, this profile its surface area when running into wearing and tearing has only very little variation.But the section of lug boss can also be that drum shown in Figure 10 maybe can have trapezoidal (Figure 11), taper shape, the cross section of pyramid or domed profiles.
Because fixedly the lug boss 3 of magnetic drum 1 must be worn in the process of initial sliding thereon satisfactorily at tape, therefore, preferably treat to be no more than 1/2 of total surface in contact zone (wearing and tearing afterwards) that lug boss and tape work mutually by the lug boss (just behind molding) of tape wearing and tearing and the surf zone of contact with tape.
Fixedly the top layer of magnetic drum 1 will be thinned to it can just can be worn away after the slip of tape short time.This can reach by temperature that reduces mould or the content that increases the fine gtinding filler material.
The pulling force of considering tape is different at the fixing on the suction side of magnetic drum 1 with outlet side, therefore, preferably lug boss 3 is set at tape on the suction side place less with the whole surface in contact zone that tape is worked mutually, and bigger at tape outlet side place, so that balance is applied to the pressure on the lug boss of fixing magnetic drum from tape.This can by enlarge lug boss 3 on the tape outlet side the surface or the mode that is increased in the density of the lug boss on the same side realize.Therefore, the lug boss on both sides can apply same pressure by tape, has guaranteed the uniform wearing and tearing of all lug bosses and reduced fixedly that the size of magnetic drum and the precision of configuration change.
Describe below with reference to Figure 12 to the 16 pair of second embodiment of the present invention: fixedly magnetic drum 21 is made with composite resin material by injection-molded.This composite resin material and molding methods are identical with described in first embodiment.As shown in figure 12, fixedly magnetic drum 21 has the part that is formed by dimpling portion 22 and nick portion 23.This dimpling portion 22 is the lug bosses that are provided with along corresponding groove shape nick portion 23 and has as shown in figure 13 sawtooth profile.This can be pre-formed etching line and realize by the mode of grinding on the inwall that is used for fixing the injection-molded metal die of magnetic drum.If any other method can realize identical effect, then also can adopt.The surface in contact zone of the dimpling portion that the initial sliding by tape after molding just wears away makes sufficiently little, make it be equal to or less than the dimpling portion of experience wear and tape cooperating whole surface in contact zone 1/2.
Figure 14 illustrates fixedly the dimpling portion 22 of magnetic drum 1 and the synoptic diagram of the relation between the guide member 24.This dimpling portion 22 can be parallel with guide member 24, but preferably tilt towards guide member 24 on the tape glide direction, as shown in Figure 12.Therefore can produce the power of tape that makes like this, increase the precision that is guided in the tape that slides on the fixing magnetic drum towards guide member 24.
Difference in height between dimpling portion 22 and the nick portion 23 is greater than skin depth.This is because if difference in height less than skin depth, just can not come out after the filling agent of fine gtinding is removed on the top layer.The top layer be the layered product that when resin moulded, forms near superficial layer, this contains very small amount of filling agent near superficial layer, for example the probability of Cun Zaiing is less than the 1/10-1/20 of the probability in any other inside part of this product.
The higher limit of difference in height is about 3 times of skin depth preferably.Under the numerical value that surpasses three times of skin depths, because of the mold shrinkage of high-performance compound resin material and the fixing mutual relationship between the external diameter of magnetic drum, the moulding resin magnetic drum is not easy to throw off with metal die.Even surpassed in described difference in height under three times the situation of skin depth, still can keep reducing the fixedly same effect of the dynamic friction between the magnetic drum and tape.
Powerful depressor effect by the tape that slides thereon makes that fixedly the dimpling portion 22 of magnetic drum 21 is worn.Therefore, identical with first embodiment shown in Figure 6, on the dimpling surface of the fixing experience wear of magnetic drum, expose the filling agent of fine gtinding, fiber filling agent, spherical filling agent and particles filled dose.Like this, fixedly the magnetic drum sliding that can demonstrate its tape is improved.Figure 15 illustrates tape along the fixing sliding time of magnetic drum and the curve map of the relation between the dynamic friction coefficient between the two.This curve map shows dynamic friction coefficient with the sliding time of tape significantly reducing at once (comparing with the situation of routine shown in Figure 2).
Dimpling portion 22 major parts have all worn away, and therefore, fixedly magnetic drum 21 increases and ended the further wearing and tearing on dimpling surface widely with the surface in contact of tape.Want the external diameter of the little fixedly magnetic drum that causes to the dimpling portion 22 that makes by experience wear and the variation of circularity can not surpass the dimpling surperficial 22 of experience wear and the difference in height between the dimpled surface 23 in the difference in height between dimpling portion 22 and the nick portion 23.This means that fixing magnetic drum 21 can keep the necessary accuracy of its configuration and size.
Even protuberance have rectangular profile 22 ' cross section (Figure 16) even or the cross section of domed profiles or rotary head drum be also can obtain identical effect with what composite resin material was made.
As described above like that, in the present embodiment, injection-molded by composite resin material, fixedly magnetic drum 21 is formed with the inhomogeneous periphery surface of groove shape.Fixedly the dimpling portion of magnetic drum is worn away by the tape that slides thereon, so that expose the filling agent composition in the dimpling portion of fixing magnetic drum 21.Therefore, can have the electric conductivity of improvement and good tape sliding at the back fixedly magnetic drum of dimpling portion wearing and tearing.
Referring to Figure 17 to 21, the third embodiment of the present invention that is applied on the rotary head drum is described:
Figure 17 is the skeleton view of rotary head drum of the present invention, and Figure 18 is its cut-open view.Rotary head drum 31 is to form by injection-molded using with the identical composite resin material of the fixedly magnetic drum that is used for first and second embodiment.Rotary head drum 31 has its peripheral surface dimpling portion 32 and nick portion 33 on its xsect.Dimpling portion 32 is the dimpling parts of arranging along corresponding groove shape nick portion 33.These dimpling portions 32 form serrate profile as shown in Figure 18.Those serrate dimplings part is provided with on the clockwise direction when rotary head drum 31 is seen at the top spirally.Therefore, when rotary head drum 31 counterclockwise rotated, tape can be subjected to the effect of downward power, makes that its lateral edges was pressed against on the guide member when it slided on rotary head drum.Therefore, the degree of accuracy of guiding tape can improve.Though illustrated embodiment has been used the rotary head drum of being arranged to rotate in the counterclockwise direction 31, but also can use the rotary head drum that rotates in the clockwise direction, the dimpling part that counter clockwise direction when this magnetic drum has from its top is provided with spirally is so that be applied on the tape that slides thereon in a power on the guide member direction.And, can also be optimized the spiral salient part of rotary head drum angle according to the velocity of rotation of rotary head drum with respect to tape, this optimization will be considered the air layer that produced between the tape of rotary head drum and slip thereon.
1/2 of the whole surface in contact that the surface in contact zone that the initial sliding of passing through tape of the dimpling portion 32 of the rotary head drum 1 that just has been molded as wears away will cooperate with tape than the dimpling portion of experience wear.Difference in height between dimpling portion 32 and the nick portion 33 is greater than skin depth.This is can not come out because if difference in height, is removed the filling agent of back fine gtinding less than skin depth on the top layer.On the contrary, under difference in height surpassed three times situation of skin depth, the precision of rotary head drum 31 can wearing away and reduce with its bossing gradually.Even its surperficial difference in height has surpassed three times of skin depth, still can keep reducing the fixedly same effect of the dynamic friction between the magnetic drum and tape.
Figure 19 is the curve map that the relation between the dynamic friction coefficient that tape causes along the sliding time and the between of rotary head drum is shown.This curve map show beginning-of-tape (BOT) the back of on rotary head drum, sliding just reduce sharp from initial time.This can explain that promptly dimpling portion 32 has been worn and has exposed the filling agent composition on its top surface, as shown in Figure 4 by such fact.
As described above such, in the present embodiment, rotary head drum 31 is formed with uneven periphery surface and the initial sliding by tape by composite resin material injection-molded and the tip of dimpling portion 32 is worn away so that expose the filling agent composition on the top surface of the dimpling portion 32 of rotary head drum 31.Like this, the sliding between rotary head drum 31 and the tape just can improve.
The unevenness of the outside surface of rotary head drum 31 can form rectangular preiection part 32 ' as shown in Figure 20 or a plurality of cylindrical protrusions part 32 " such as shown in figure 21.
Though fixedly magnetic drum and rotary head drum are to use composite resin material to make by injection-molded among the shown embodiment, but the present invention is not limited to top mentioned manufacture method, but the method that can adopt other extrusion molding for example, compression molding, machining is ground etc.Material is not limited to high performance high polymeric compound.It can be for example based on the compound substance of standard plastic.And the present invention can also be applied to rotary head drum simultaneously and fixedly on the magnetic drum.
Much less, except that video tape recorder, the present invention can also be applied on other the magnetic recording (for example digital audio blattnerphone).
Obviously can find out that from the explanation of front magnetic recording/reproducing device of the present invention provides following advantage:
Fixedly magnetic drum and/or rotary head drum its external peripheral surface have the surface part of comprising and The mixing portion of filler expose portion, and therefore can have and tape between reduced Dynamic friction coefficient so that the latter can and smoothly slide along the stable ground of magnetic drum.
Fixedly magnetic drum and/or rotary head drum have little protuberance of forming at its circumferential surface and little Recess, the difference in height between this little protuberance and the little recess be greater than skin depth, and by with magnetic Friction effect between the band little protuberance surface is worn so that expose before add to compound Be used for improving the electric conductivity on magnetic drum work surface and the filler composition of sliding in the resin material. Therefore fixedly magnetic drum and/or rotary head drum can have and tape between littler dynamic friction Coefficient so that the latter can stablize and steadily slide thereon.
Claims (9)
1. magnetic recording/reproducing device, described device is provided with rotary head drum and fixedly magnetic drum that is used to guide the tape slip of a playback head of a supporting, wherein, in described rotary head drum and the described fixedly magnetic drum any one is to make with the composite resin material that contains filling agent at least, and form a solid magnetic drum of single-piece, the solid magnetic drum of described single-piece forms on the peripheral cylindrical surface that its tape slides has the inhomogeneous configuration of the first top layer part and the second filling agent expose portion, the described second filling agent expose portion is the bossing of inhomogeneous configuration, described bossing slides the wearing and tearing of described first top layer on described solid magnetic drum owing to tape and exposes that described filling agent forms, treat the described bossing that worn and torn by tape and the contact portion of tape, after being worn, should be not more than with area of the contact portion of tape described bossing and tape work total contact area 1/2, and the height of described bossing is greater than the thickness of described top layer part.
2. magnetic recording/reproducing device as claimed in claim 1, it is characterized in that: described filling agent can be used for and any fiber as glass fibre, carbon fiber, potassium titanate crystal whisker, globule as glass bead, carbon globule, spherolite, particle, powder or as carbon film plate, carbon black diaphragm talcum diaphragm, mica diaphragm combination.
3. magnetic recording/reproducing device as claimed in claim 1 or 2 is characterized in that: described composite resin material is the potpourri that is selected from polyphenylene sulfide, polycarbonate, polyethersulfone, polyetheretherketone, liquid crystal polymer, the inferior acid amides of polyethers or described superpolymer and compound thereof.
4. magnetic recording/reproducing device as claimed in claim 1 or 2, it is characterized in that: described fixedly magnetic drum has inhomogeneous configuration, is less than from the center of described rotary head drum to the distance of the tape slidingsurface of described rotary head drum from the center of described fixedly magnetic drum to the distance of the depressed part office of described inhomogeneous configuration.
5. magnetic recording/reproducing device as claimed in claim 3, it is characterized in that: described fixedly magnetic drum has inhomogeneous configuration, is less than from the center of described rotary head drum to the distance of the tape slidingsurface of described rotary head drum from the center of described fixedly magnetic drum to the distance of the depressed part office of described inhomogeneous configuration.
6. magnetic recording/reproducing device as claimed in claim 1 or 2, it is characterized in that: described fixedly magnetic drum has described uneven configuration and a guide member that is used to guide tape, and described inhomogeneous configuration is arranged to parallel with the glide direction of tape or downward-sloping towards described guide member.
7. magnetic recording/reproducing device as claimed in claim 3, it is characterized in that: described fixedly magnetic drum has described uneven configuration and a guide member that is used to guide tape, and described inhomogeneous configuration is arranged to parallel with the glide direction of tape or downward-sloping towards described guide member.
8. magnetic recording/reproducing device as claimed in claim 1 or 2 is characterized in that: described rotary head drum has described inhomogeneous configuration, and described inhomogeneous configuration is provided with spirally towards the described direction of executing the direction of rotation of changeing magnetic drum.
9. magnetic recording/reproducing device as claimed in claim 3 is characterized in that: described rotary head drum has described inhomogeneous configuration, and described inhomogeneous configuration is provided with spirally towards the described direction of executing the direction of rotation of changeing magnetic drum.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP162601/96 | 1996-06-24 | ||
| JP8162601A JPH1011849A (en) | 1996-06-24 | 1996-06-24 | Magnetic recording and reproducing device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1173694A CN1173694A (en) | 1998-02-18 |
| CN1086042C true CN1086042C (en) | 2002-06-05 |
Family
ID=15757696
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN97114050A Expired - Fee Related CN1086042C (en) | 1996-06-24 | 1997-06-24 | Magnetic recording/reproducing device |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPH1011849A (en) |
| CN (1) | CN1086042C (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006024155A (en) * | 2004-07-09 | 2006-01-26 | Workbit Corp | Peripheral device |
| JP5000951B2 (en) * | 2006-09-01 | 2012-08-15 | 東北リコー株式会社 | Stencil box for stencil printing machine |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05314599A (en) * | 1992-04-13 | 1993-11-26 | Sony Corp | Magnetic drum and formation thereof |
-
1996
- 1996-06-24 JP JP8162601A patent/JPH1011849A/en active Pending
-
1997
- 1997-06-24 CN CN97114050A patent/CN1086042C/en not_active Expired - Fee Related
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05314599A (en) * | 1992-04-13 | 1993-11-26 | Sony Corp | Magnetic drum and formation thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1173694A (en) | 1998-02-18 |
| JPH1011849A (en) | 1998-01-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1063276C (en) | Optical-information intermediat medium and production method, equipment thereof | |
| CN1619690A (en) | Reel of magnetic tape cartridge | |
| CN1969137A (en) | Fluid bearing device and its manufacturing method | |
| CN87102398A (en) | The holo-fluorine polyester endo-oil that is used for magnetic recording medium | |
| CN1821598A (en) | Fluid dynamic bearing device and motor equipped with the same | |
| CN1129041C (en) | Developing device and magnetic roller for the same | |
| CN1516146A (en) | Optical disk and its producing method | |
| CN1086042C (en) | Magnetic recording/reproducing device | |
| CN1791904A (en) | Process for producing magnetic recording medium and magnetic recording medium | |
| CN1165919C (en) | Magnet powder-resin compound particles, method for producing such compound particles and resin-bonded rare earth magnets formed therefrom | |
| CA2419721C (en) | Method for manufacturing elastic cylindrical body, method for manufacturing elastic roll, elastic cylindrical body and elastic roll | |
| CN101048708A (en) | Conductive roller | |
| CN1301288C (en) | Polyester film, magnetic recording tape and digital recorder for magnetic recording medium | |
| CN1212616C (en) | Turntable device and manufacturing method thereof | |
| CN1152375C (en) | Optical information medium and optical information recording method | |
| CN1739153A (en) | Turn table device manufacturing method and turn table device | |
| JPS5880140A (en) | Manufacture of recording medium | |
| CN1502105A (en) | Tape reel and tape cartridge having the same | |
| JP2005219169A (en) | Grinding wheel and its manufacturing method | |
| CN1241191C (en) | Optic disk mfg. method and device | |
| JPH09111037A (en) | Molding resin material and molding of the resin androtary head drum device produce from the molding resinmaterial | |
| CN217728382U (en) | Polishing jig and 3D polishing equipment | |
| CN1303605C (en) | Magnetic tape cassette | |
| CN1134021A (en) | Tape cartridge | |
| JP2807836B2 (en) | Polishing method for backside of stamper for manufacturing optical disc |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C06 | Publication | ||
| PB01 | Publication | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |