JPH0397150A - Tape position adjusting mechanism - Google Patents

Abstract

PURPOSE:To comprise a tape feed system without a fear to impair a tape and to realize the long time preservation of a record and large capacitance of a thin tape by inclining two guide posts arranged interposing the tape in parallel as keeping parallel relation between them in the inside of the tape. CONSTITUTION:The mechanism is comprised of a sensor 8 which detects a tape position at an arbitrary point (just before the entry of a rotary drum 4) in a tape 5 feed system, and a post string 9 consisting of the two guide posts 2, 3 inclined based on the output of the sensor 8. And the tilt angles of the two parallel guide posts 2, 3 are varied with a tape position signal detected with the tape position sensor 8, and a tape position error is reduced, and the tape 5 is fed within an allowable position range. Therefore, a feeding path can be formed between the two guide posts 2, 3 inclined in parallel with each other, and the change of a feed direction and the twist of the tape 5 gener ated on the guide post 2(3) on one side can be cancelled to a level without generating a trouble in practical use on the guide post 3(2) on the other side, and only the feed position of the tape 5 is varied by the inclination of the posts 2, 3. Thereby, the tape with thin thickness is used.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a tape running position adjusting device. More specifically, the present invention relates to a device for adjusting the tape running position in the tape width direction in a tape running system of a magnetic recording/reproducing apparatus using magnetic tape.

(Prior Art) In conventional video tape recorders (VTRs) and audio tape recorders (DTAs), tape edges are regulated at the front and rear posts of a rotating drum with reeds so that the head correctly scans the signal track on the tape. A flange is provided to push the tape down and run along the lead on the lower drum. This tape position regulation method does not cause wrinkles or damage the tape edges with current relatively thick and strong tapes, but in the future it may be possible to use thinner tapes to increase storage capacity. If this occurs, it is difficult to run the tape without causing wrinkles or damage to the edges. For this reason,
There is a need for a technology that allows the tape to run in a fixed position without the need for flanges or leads that mechanically restrict the tape edge.

As a tape running position adjusting device that detects the running position of the tape and adjusts the tape position by tilting a post based on the detected value, a device such as that disclosed in Japanese Patent Application Laid-Open No. 70813/1983 is known. As shown in FIG. 9, this tape running position adjusting device has a light source 102 and a photo sensor 103 placed between them, a tape 101, and a post 105 whose inclination changes depending on the output of the photo sensor 103. The inclination of the post 105 is changed by a solenoid 106 so that the tape edge runs at a reference running position, and the tape 101 is slid on the post 105 to adjust the tape position. (Problem to be Solved by the Invention) However, when adjusting the tape position using one inclined post, the deviation in the width direction perpendicular to the tape running direction is automatically corrected, but at the same time the tape is twisted. If you use thin tape, there is a risk that the edges will curl like seaweed. In other words, as shown in FIG. 2(A), the vector along the tape center line is the traveling direction vector t=(t,
,t,,t. >', a vector in the tape plane and perpendicular to the running direction vector t is defined as a tape width direction vector w = (w
,,w,,wt) t (where t on the shoulder means transposition), then t. =(1,0,Q)',w,=(0,0.1
When a tape of ．． t 2 = P + IR 1P It lW2
From =P+ R+ pl t W+ (where P and R are 3×3 matrices), the two-way component of t2 sing1coscyt(1-cos
Since θ1) is not O when ar~0, the tape passing through the post has an inclination, and the height of the tape changes linearly as it leaves the post. The Z direction component of t2 is Sinα
Since tCOSd+=1/2Sin2 a is proportional to r, the tape running position can be changed by α1, but a change in t2 changes the running direction, and a change in W2 causes tape twisting. I end up. The present invention is capable of regulating the tape running position so that the tape runs at the correct position without mechanically regulating the tape edge or applying excessive force to the tape. The purpose of this invention is to provide an adjustment device and enable the use of thin tape. (Means for Solving the Problems) In order to achieve the above object, the present invention includes a sensor that detects the position of the tape in the width direction, and a drive means that moves the tape in the width direction based on the output of the sensor. In the tape position adjustment am, the drive means adjusts the widthwise position of the tape by changing the inclination angle of two parallel guide posts that sandwich the tape.
Further, the tape running position adjustment mechanism of the present invention is constructed by disposing the two parallel guide posts at the inlet or outlet side of the rotating head drum, or both. Further, the two guide posts of the tape running position adjustment 8l according to the present invention are simultaneously tilted by a member driven by one driving means. Further, the guide post of the tape running position adjusting aam of the present invention has an air blowing hole. (Function) Therefore, a running path is created between the two guide posts that are inclined parallel to each other, and changes in the running direction or twisting of the tape that occur at one guide post are at a level that does not pose a practical problem at the other post. , and only the running position of the tape changes depending on the inclination of the post. For example, the two guide posts shown in FIGS. 3(A) and 3(B) have tape wrapped around them alternately at the same angle, so that they are parallel to each other and inclined within the plane of the tape. The running direction vector and axial direction vector of the tape that has passed through the inclined post row made up of these two parallel guide posts are given by the following equations. t3 = Pz lR2 P2 tz = P 2 R2 P 2 ' P + R + P
+ tt lWs = p2R2P2tw. = P 2 anus 2 P 2 ' P + anus, P, 'wt2
Since the guide posts of the book are parallel, P2=PI. Also, P. There is a property that PI' = I[. Furthermore, θ
2=-θ, so IR x = R r −' ):
．． ．． 'C, P2 O2 P- t P+ lR+ P +
' = I [■: Due to the identity matrix, t3 = tl w3 = w, this relationship does not depend on the values of αl and θl. The difference in height of the tape before and after passing through this row of inclined posts is mainly 2
Although h1 is caused by the slope of the tape stretched between the guide posts of the book [Fig. 3 (C) and (D)], there is also a height change h2 in the section where the tape is wrapped around the posts. h + = RSln(? (1-cosθ)h.
= r (θ-sin θ)sina h ” h + + 2 h 2 = (R (1-cos θ) + 2r( θ-si
nθ) l Sina Although R and θ may change with changes in α due to the mechanism that tilts the tilted post row, the effect on h is slight, so h changes approximately in proportion to sinα. (Example) Hereinafter, the configuration of the present invention will be explained in detail based on an example shown in the drawings. FIG. 1 shows a perspective view of an embodiment in which the tape position adjustment mechanism of the present invention is installed near a rotating head drum. This tape position adjustment mechanism includes a sensor 8 that detects the tape position at an arbitrary point in the tape running system (in this embodiment, immediately before the entrance of the rotary drum), and a sensor 8 that is tilted based on the output of the sensor 8.
It is composed of a post row 9 consisting of book guide posts 2.3, and the inclination angle of the two parallel guide posts 2.3 is changed according to the tape position signal detected by the tape position sensor 8 to reduce the tape position error. and tape 5
The system is designed to run within the permissible position range. As the tape position sensor 8, a non-contact type optical sensor such as a combination of a light source 6 and a light amount detector 7 placed opposite to each other with the tape 5 in between is preferable, but there is no particular limitation and it can be operated with small contact pressure. A transformer, capacitive sensor, magnetic sensor, ultrasonic sensor, etc. may also be used. Further, the tape position sensor 8 may be a reflective sensor using a post for pulling out the tape 5 from a cassette (not shown), such as a pack tension post or a loading post. This reflective sensor has a light emitting part and a light receiving element arranged outside the tape 5, emits light towards the post and receives the reflected light, and determines the widthwise position of the tape wound around the post by the amount of reflected light. It is measured by the change in . The inclined post row 9 for changing the tape running position is composed of two mutually parallel guide posts 2 and 3 that change the running position of the tape 5 by changing the inclination angle.
Although the guide posts 2 and 3 are not particularly limited in their cross-sectional shape, they must be posts with at least a curved surface in the area that contacts the tape 5, such as a perfect circular cylinder, a semicircular cylinder, or an elliptical cylinder. etc., and it is preferable to use a perfect cylinder or a semi-cylindrical cylinder. Also, guide post 2
．． 3 are arranged in a staggered manner with respect to the tape running path, and it is necessary that at least no flanges exist within a range where the tape 5 wound around each can cause fluctuation in the width direction. If these guide posts 2.3 are not kept parallel to each other, the tape will be twisted, so the VTR should be set so that they are kept parallel to each other under any conditions.
It is supported by the chassis, etc. For example, it is structurally simple to attach two guide posts 2 and 3 to the same member in parallel and move them together. Of course, it is also possible to synchronize and drive each guide post 2.3 separately. Since the guide posts 2 and 3 do not rotate and the tape slides over them, as the wrapping angle increases, the tape tension increases unnecessarily. In such a case, it is preferable to provide air blow holes (not shown) in the guide posts 2.3 to reduce the friction between the tape 5 and the guide posts 2, 3. ．． In addition, by providing air blowing holes in the guide posts 2 and 3, the friction of the tape 5 in the post axial direction is also reduced, so that the movement of the tape 5 on the guides 2 and 3 caused by the inclination of the guide posts 2.3 is reduced. This also improves the responsiveness of tape position displacement to the inclination of the guide posts 2 and 3.

Note that if the tape running path including the above-mentioned inclined post row 9 and tape position sensor 8 is long, there is a possibility that a considerable portion of the tape position displacement occurring in the inclined post row 9 will be absorbed by the deflection of the tape 5. Therefore, as shown in Fig. 4, the tape running path including the inclined post row 9 should be made as short as possible, and devices that strongly hold the tape, such as guide rollers, reels, and capstans, should be placed near the inclined post row 9. However, it is preferable that the location for regulating the tape position be placed as close to the inclined post row 9 as possible on the opposite side of the inclined post row 9.

That is, when the tape 5 passes through the guide roller (or post) 1 and wraps around the rotating head drum 4, the inclined post row 9
is a guide roller (or post) 1 and a rotating head drum 4
It is preferable that a tape position sensor (light receiving element) 7, which is disposed between the tape 5 and the tape 5 and detects the vertical position of the tape 5, be disposed near the inclined post array 9 at the rear of the inclined post array 9. Figure 5 shows an example of an inclined post row. This inclined post row 9 has two guide posts 2.3 mounted on a support lever 10 so as to be parallel to each other, and a tape position sensor 8.
They are moved together by an actuator, for example, a bimorph piezoelectric element 11, which is driven by the output of , and are tilted while maintaining a parallel relationship with each other. The support lever 1o is activated by the operation of the bimorph type piezoelectric element 11.
Since the entire device swings around the rotating shaft 12, the two guide posts 2 and 3 tilt while maintaining their parallel relationship.
The movement of the bimorph piezoelectric element 11 is transmitted to the support lever 1o via a connecting plate 13 made of a leaf spring. here,
The bimorph type piezoelectric element 11 is made by sandwiching a copper plate and piezoelectric ceramics on both sides, and by connecting one electrode to the double-opened piezoelectric ceramics and the other electrode to the copper plate in the middle, and selectively energizing the piezoelectric ceramics. This is a known actuator that can be deflected by applying displacement to an arbitrary surface.

The actuator is not particularly limited, but it is preferable to use the bimorph piezoelectric element and voice coil motor of this example. Incidentally, the reference numeral 14 is a support stand. FIG. 6 shows another embodiment of the inclined post. In this embodiment, the guide posts 2 and 3 are respectively connected to the pillars 20 of the support base 21.
At the same time, the lower ends of each guide post 2, 3 are connected by a connecting plate 22, and the connecting plate 22 is moved by a bimorph type piezoelectric element 11, so that each guide post 2, 3 can be moved freely. The two guide posts 2 and 3 are tilted while being kept parallel to each other by simultaneously rotating them around rotational axes 27 and 28. The bimorph piezoelectric element 1l and the connecting plate 22 are rotatably connected via links 23, respectively. Although the mechanism is more complicated than that shown in FIG. 5, it is advantageous in terms of responsiveness because the moment of inertia can be reduced. Incidentally, reference numerals 24, 25, and 26 are rotation shafts for rotatably attaching the connecting plate 22 and the sensor 23 to the guide post 2.3 and the mounting plate 29, respectively. FIG. 7 shows an example of a tape running system using the tape running position adjusting device of the present invention for a β-type VTR. This tape running system consists of tape position sensors 8-1, 8-2 placed before and after the drum 30 and fixed head 31, and an array of inclined posts!
．． ．． ! 2, the tape running position is regulated at two locations, and the running position and running attitude of the tape 5 between the two locations are controlled. There is a guide roller 32 in front of the inclined post row 9- placed in front of the drum 30, and the inclined post row 9- placed after the drum 30 and the fixed head 31.
2, there are guide rollers 33 and cab stans 34 for each inclined post row 9-+. This is useful for reliably transmitting the tape position displacement caused by 9-x to tape 5. This traveling system does not require leads or flanges. In addition, code 35
is a supply reel, 36 and 37 are guide posts, 38 is a full-width erasing head, and 39, 40 are sensors 8-. , 8-2 based on the outputs of the inclined post rows 9-, . A control circuit for driving the actuator 9-2, 41 a pinch roller, 42 a guide roller, and 43 a take-up reel.

FIG. 8 shows another example of a tape running system using the tape running position adjusting device of the present invention for a VHS type VTR.
In this tape running system, an inclined post row 9-S is placed immediately after the supply reel 50 to absorb positional fluctuations of the tape 5 coming out from the reel 50.Most of the tape positional fluctuations of the VTR are This is caused by irregular winding of the tape 5 on the reel 50, and if this tape position fluctuation is removed immediately after the reel 50, the downstream tape position can be easily regulated. If the tape 5 is sent out with the tape position fluctuation sufficiently reduced by the inclined post row 9-, there is no fear of damaging the thin tape even if the conventional 7 lunge and lead are used as tape position regulating means on the drum 56. ．． Of course, like the tape running system described above, the inclined post rows 9-. ．． 9-2 may be used to regulate the tape position on the drum.

In addition, the tape position on the cabstan 61 may change during reverse playback, fast forwarding, or rewinding, but in such cases, it is necessary to install the inclined post row 9 between the capstan 61 and the fixed head 59. Good. In addition, numeral 50 is a supply reel, 64 is a control circuit, 8-3 is a tape position sensor, and 5
1 is a post with a lower regulation 7 lunge, 52 is a full width erasing head,
53 is an impedance roller, 54 is a post with an upper regulation flange, 55 is an inclined post, 56 is a cylinder, 57 is an inclined post, 58 is a post with an upper regulation flange, 5 is a fixed head, 60 is a post with a lower regulation flange, 61 is a capstan, 62 is a vinyl roller, and 63 is a take-up reel. Since the tape running position adjusting device of the present invention is configured as described above, the width direction position of the tape 5 is detected by the sensor 8,
Depending on the output, inclined post row 9 or 9-. When a driving voltage is applied to the actuator 9-, for example, the bimorph piezoelectric element 11, the bimorph piezoelectric element 11 is deflected, and in response to this deflection, the two guide posts 2.3 are simultaneously tilted by the same amount while maintaining a parallel state. ．． Due to the inclination of the guide posts 2 and 3, the tape 5 slides on the posts 2 and 3 in relation to the tape tension, changing the tape running position. (Effects of the Invention) As is clear from the above explanation, the tape running position adjusting device of the present invention tilts the two guide posts installed parallel to each other while sandwiching the tape while maintaining a parallel relationship within the tape plane. As a result, changes in the tape running direction and twisting of the tape that occur when passing through the previous guide post are offset by the subsequent guide post, and only the tape running position is changed.

Therefore, even in a tape running system where there are no flanges or leads on the tape guide post or rotating head drum, or even if such leakage control means are provided, the tape can be run at a fixed position. Therefore, a tape running system can be constructed that does not have to worry about damaging the tape, making it possible to record for longer periods of time and increase capacity by using thinner tapes.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of the tape running position adjusting mechanism of the present invention, and FIG. 2 shows the principle of adjusting the tape position in the conventional tape running position adjusting mechanism shown in FIG. A) is an explanatory diagram that defines each vector component for the tape, (B) is a plan view showing the relationship between the inclined post and tape displacement, and (C) is its front view. FIG. 3 shows the principle of adjusting the tape running position in the TEG position adjustment machine of the present invention, in which (A) is a plan view showing the relationship between the tape and the guide post, (B) is a front view thereof, (C) is a plan view explaining the relationship with the distance between guide posts, and (D) is its front view. FIG. 4 is a perspective view showing the arrangement of the tape running position adjustment mechanism of the present invention, FIG. 5 is a perspective view showing an example of the guide post tilting mechanism of the present invention, and FIG. 6 is a perspective view of the guide post tilting mechanism of the present invention. FIG. 7 is a perspective view showing another embodiment of the mechanism; FIG. 7 is a plan view of a tape running system showing an embodiment in which the tape running position adjusting mechanism of the present invention is installed near the rotary head drum of a β-type VTR; FIG. Same <VHS
FIG. 2 is a plan view showing an embodiment in which the present invention is applied to a tape running system of a VTR. FIG. 9 shows the conventional tape running position W. It is a principle diagram showing the adjustment mechanism. 9.9-1.9-2.9-s...
Inclined post row 2.3...Guide post, 5...Tape, 8.8-. ,i. , 8-1...sensor, 6...light source,
7... Light receiving element, 11... Actuator.

Claims (4)

[Claims] (1) In a tape position adjustment mechanism comprising a sensor that detects the position of the tape in the width direction and a drive unit that moves the tape in the width direction based on the output of the sensor, the drive unit includes two parts that sandwich the tape. A tape position adjustment mechanism that adjusts the widthwise position of the tape by changing the inclination angle of guide posts parallel to the book. (2) The tape position adjustment mechanism according to claim 1, wherein the two parallel guide posts are arranged on the inlet side or the outlet side of the rotary head drum, or both. (3) The tape position adjustment mechanism according to claim 1 or 2, wherein the two guide posts are simultaneously tilted by a member driven by one driving means. (4) The tape position adjustment mechanism according to any one of claims 1 to 3, wherein the guide post has an air blowing hole.