JPS60154350A - Tape loading mechanism - Google Patents

Abstract

PURPOSE:To attain a stable tape running state by moving the first and the second moving bodies, which are placed in a notch of a cassette and are provided with tape guides to such positions that a tape is wound at a prescribed lead angle around a drum at a loading time. CONSTITUTION:A head drum 1 is inclined at an angle equal to a tape winding lead angle LA to a perpendicular on the loading plane of a cassette 90, and a tape 9i is wound spirally around the drum 1 while raising it at the lead angle LA. A moving body 20 provided with tape guides 21-23 and a moving body 30 provided with tape guides 31 and 32 are placed in a notch 91 of the cassette 90, and a loading gear 85 is rotated, and the moving body 20 is moved through a loading ring 4 while being guided by a guide body 5. The moving body 30 is moved such position through the ring 4 and a gear omitted in the figure that the angle of a tape 9b to the drum 1 is widened, and the moving body 30 is arranged in the position where running of the tape 9b is held at the same height of a reel of the cassette 90. Thus, a stable running state is attained with a small-sized mechanism.

Description

[Detailed description of the invention]

The present invention relates to a tape loading mechanism for a VTR. [Prior Art] As one of the tape loading methods, the so-called new U loading method is known, which is devised to reduce the thickness of the loading device (Japanese Patent Application Laid-Open No. 5786161). In recent years, the miniaturization of VTRs has progressed, and a new standard of compact VTRs called 8 mm video has been developed, and if the new U loading method is used for this 8 mm video, it will be advantageous for miniaturization. 1 As shown in Figure 16, this method basically uses a plurality of cylindrical tape guides that pull out the magnetic tape (9) from the tape cassette (1) and wrap it spirally around the head drum (1) while raising it. Tape withdrawal means (8) comprising:
, tape pull-out pin (86) and pinch roller (88)
) to pull out the tape horizontally from the cassette ((a)) and press the tape to the capstan (81). (1); a movable base (87) slidably fitted to the guide; and four tape guides (87) disposed on the movable base. t83>t84) tB4
> and a loading ring (not shown) that is arranged below the inclined guide body to surround the head drum (1) and rotates in a horizontal plane, and the movable platform (87) is driven by the loading ring. be. The two leading tape guides among the four tape guides (83)
is located inside the cassette cutout (91), that is, within the loop of the tape (9n) before being pulled out, as shown by the two-dot chain line in the figure in the unloading state, but the following two (
84) f84) is the preceding two (83+ +83
Since it is located at a distance behind the +, the cassette notch (
91), that is, outside the tape loop. Therefore, the preceding two can be fixedly installed on the moving table, but if the following two are fixedly installed, they cannot enter the deep loop due to the loading method, so immediately after starting loading, It has a stand-up type configuration in which the tape is laid down and then stands up after entering the tape loop. This has the disadvantage that the tape loading mechanism is extremely complicated. Tensile stress acts on the tape while it is running, but it is desirable that this stress be uniform in the width direction of the tape.To do this, each tape must be adjusted so that the following three conditions (stable running conditions) are met. It is necessary to determine the position and posture of the guide. ■ Conditions for no twisting: The tape must not twist between the cassette entrance and exit, each tape guide, and the head drum. ■ Height conditions (see Figure 16.17) The height of the tape center line from the cassette mounting surface is the tape incidence point (9u) on the tape guide (89a) closest to the supply reel (!112), and the winding Tape separation point (9) in the tape guide (89b) closest to the take-up reel (93)
v) is equal to ■ Parallel condition First tape guide (89a) from the cassette entrance/exit
The running direction of the tape toward (89b) is parallel to the cassette mounting surface. However, in the conventional new U loading method, when the diameter of the loading ring is made as small as possible in order to downsize the mechanism, the position and posture of the tape guide is restricted, making it impossible to meet the above stable tape running conditions. For example, there was a problem that twisting occurred between the tape guides. In order to solve the first problem, that is, the tape loading mechanism is complicated, the applicant has proposed a tape loading mechanism with a new structure (Utility Application No. 58-19).
7017). [Object of the Invention] The present invention eliminates the need for a stand-up type tape guide by defining the position and orientation of each tape guide that satisfies stable tape running conditions for the tape loading mechanism proposed by the applicant. It is an object of the present invention to provide a tape loading mechanism that has a simple structure and can achieve a stable tape running state without causing uneven stress on the running tape. [Structure of the Invention] In the present invention, the head drum (1) is installed at an angle equal to the winding lead angle LA of the tape with respect to the perpendicular to the cassette mounting surface, and the magnetic tape (90) is inserted from the tape cassette (90). ) in a tape loading mechanism that pulls out a tape and winds it spirally around the head drum while raising it at a lead angle LA, in which a first tape pull-out means and a second tape pull-out means are provided near the head drum (1). However, the first tape pulling means includes a plurality of cylindrical first tape guides (2) provided on the first moving body (20) and the moving body z i -t==
y′1 0″ rise a°°゛゛゛′ one or more cylindrical second tape guides (3) including one tape guide and the second movable body (to) the first movable body (20)
a second driving body for moving the first tape guide (2) in a direction away from the head drum from a movement path of the first tape guide (2);
The tape guides on the second movable body (30) are located in the cassette notches (91) in the unloading state, and the tape guides on the first and second tape guides (2+ +31) are in the loading state. has a central axis in a plane parallel to the surface of the tape that is guided without twisting from the head drum side toward the tape guide, and is located in the first tape guide (3) on the tape transition path. The leading second tape guide (31) close to the tape guide (2) is arranged such that the running direction of the tape (9b) from the guide (31) in a direction away from the head drum (1) is parallel to the cassette mounting surface, and the tape It is characterized in that its surface is inclined so as to be perpendicular to the cassette mounting surface, is at the same height as the supply or take-up reel in the cassette, and is located at a position where this height can be maintained. Effect of the invention] The first tape guide (2) and the tape guide on the second moving body (301) which are present in the cassette cutout (91), that is, within the tape loop, are connected to the first moving body (301) during unloading.
20) and the second moving body (3[1 are driven by the first and second driving bodies to move along a predetermined path,
The tape (9) is pulled out from the cassette (90) to be in a loading state. At this time, the first tape guide (2) is connected to the head drum (1).
On the other hand, the tape is started to be applied in a plane parallel to the cassette mounting surface, and then wound at a predetermined angle (approximately 220 degrees) while being raised along the drum surface. Since the head drum (1) is inclined at the same angle as the predetermined lead angle LA along the surface of the attached tape, the tape is wound at the lead angle LA while being in close contact with the drum surface. Body (30
) upper tape guide pulls out the tape parallel to the cassette mounting surface and in a direction away from the head drum (1), and pulls out the tape parallel to the cassette mounting surface and in a direction away from the head drum (1).
The tape mounted between the head drum (1) is kept out of contact with the head drum (1). In the loading state, the first and second tape guides (
2) (Each of the 31 tape guides has an axial vector inclined in a direction parallel to the surfaces of the tapes upstream and downstream thereof, so that the tape guides from the head drum (1) pass through these tape guides into the cassette ((1)). There is no twist in the tape that returns to the head drum (1) and the second tape from the cassette (98).
The running direction of each tape heading toward the tape guide (3) is parallel to the cassette mounting surface, and the height of the tape is equal to the cassette mounting surface. [Special Effects of the Invention] In the tape loading mechanism according to the present invention, the tape loop is expanded to the outside of the head drum by the second tape guide located in the cassette notch during unloading, so that when loading is completed, Even if the distance between the plurality of first tape guides around which the tape is wound around the head drum is short, stable running conditions for the tape should be satisfied (the attitude of each tape guide can be defined. Therefore, the first tape guide and All the tape guides on the second moving body can be positioned within the cassette notch, and the tape guide is of a rising type (the structure is simple, and uneven stress does not occur on the running tape. Below, An embodiment in which the present invention is applied to an 8mm video will be described with reference to the drawings.The loading mechanism of this embodiment is basically a new U loading mechanism adopted for an 8mm video, and can be roughly divided into tape pull-out pin mechanisms. , is divided into a first tape pulling means and a second tape pulling means. First, the first and second tape pulling means are shown in FIGS.
This will be explained according to figures (a) and (b). A cassette (with a supply reel (92) and a take-up reel (9)
3) A tape (9) is installed between them, and a notch (91) is formed at the front of the cassette. This cassette (CfJ) can be raised and lowered by a cassette bolter (not shown). The head drum) has a built-in video head (not shown), and the center axis of the drum is at a lead angle LA (4
, 885 degrees) and parallel to the direction of the arrow (9th (See Figure (b)).A circular loading ring (4) is rotatably disposed around the head drum (1), and a gear portion (40) is formed on the outer periphery of the ring. A joint (411) is mounted on the loading ring (4) as shown in FIG. 3, with one end of the joint 411 connected, and is rotatable in the vertical direction and is biased by a coil spring. The other end of the joint A first movable body (201) is coupled to the first movable body, and the first movable body is supported by a guide body (5) provided over about 270° around the outer periphery of the loading ring. As shown in FIG.
) is movably supported by engaging with the upper and outer surfaces of the A cylindrical leading first tape guide (211 (22+ and trailing first tape guide diagram) is installed on the first moving body. As shown in FIG. 4, the leading first tape guide ( 21) A projecting pin +50+ is provided below, and the first
At the loading completion position where the movable body (20) moves forward the most, a fixed block arranged on the side of the head drum (1)
Engages in the recess (11) of the lock (10). As shown in Fig. 2, there is a tape transfer path near the head drum (1) in the loading state.
Attach the wrapping angle defining tape guide (241f2fi) to the position that defines the wrapping angle of the tape (9) to approximately 2200 with respect to 1).
is permanently installed. Further, a full-width erasing head (25) is disposed opposite the tape transition path between the first leading tape guide (21) and the wrapping angle regulating tape guide (24) in the loading state shown in FIG. There is. Near the tape drawer side of the cassette (!J)), place the spindle (!
One end is pivoted to 33), and the leading second tape guide (3
A lever-shaped second moving body (30) is provided. Regarding the lever pull-out mechanism for the second moving body, the sixth
This will be explained according to figures (a) and (b). Second moving body (30)
A first gear (34) is disposed coaxially with the support shaft (33), and this first gear (34) meshes with a fan-shaped gear (6) pivotally supported on the support shaft (60). There is. This fan-shaped gear (6
) is provided with an engagement pin (62), and this engagement pin (62) engages with a cam groove (64) of the second gear (63). The second gear (63) is meshed with the gear portion (40) of the loading ring (4) via a third gear and a fourth gear. Therefore, the second moving body (30) has a loading ring (4
) is pulled out together with the tape (9) from the position al to the position shown in FIG. 6 (b).
On the tape transition path between the tape guide (31) and the supply reel stand (92), a wrap angle defining tape guide (32) is vertically positioned at a position that defines the wrap angle of the tape to a predetermined value with respect to the tape guide. It is fixedly installed. Since various conventionally known mechanisms can be applied to the tape pull-out pin mechanism, a brief explanation of FIGS. 1 and 2 will be given here. The pinch roller (88) for the capstan (81) is connected to the pinch roller lever (70) which is pivotally supported on the support shaft (71).
) The support shaft (71) is supported on a slide member (7). A tape pull-out pin (86) is also provided on the slide member. A gear portion (72) is formed on one side of the slide member, and this gear portion (72) meshes with a loading gear (85) coupled to a loading motor (not shown). The loading gear (4) also meshes with the gear portion (40) of the loading ring (4) via a small gear, so that the loading ring (4) and the slide member (7) are driven synchronously. Next, the operation of the tape drawing means will be explained. First, as shown in Fig. 1, when the cassette (1) is inserted into the cassette holder (not shown) and lowered to the mounting position, the loading motor (not shown) is energized and the loading gear (85) starts clocking. As a result of this rotation, the loading ring (4) is driven clockwise, and as shown in Fig. 2, the first moving body (20) is driven via the joint (41). Tape guide f21) (22) (23) pulls out the tape (9) and winds it around the head drum (1). At this time, the first movable body (20) is guided along a predetermined path by the guide body (5), and when it reaches near the end, the tip of the protruding pin (50) touches the fixed block as shown in Fig. 5(a). (10)
It abuts on a part of the recess (11). In this state,
Although the protruding pin (50) is not parallel to the side wall of the recess (11), by further driving the loading ring (4), the protruding pin (50) is aligned with the recess (11) as shown in FIG. 5(b).
) It becomes parallel to the side wall and is in a crimped state. In this crimping state, the inclination angle of the first moving body (20) is different from before crimping, but the convex portion (51) of the first moving body (20) before crimping
is engaged with the guide groove (52) of the guide body (5) with a margin, so that the movable body can be displaced within this margin. On the other hand, due to the clockwise rotation of the loading gear (85), the slide member (7) slides toward the upper right in FIG. This slide causes the tape pull-out pin (86) to pull out the tape (9) in the upper right direction as shown in FIG. On the other hand, the second moving body (3o) is pulled out from the state shown in FIG. 1 to the position shown in FIG. 2 by the lever drawing mechanism shown in FIGS. 6(a) and 6(b). When the loading is completed as described above, the tape (9) is wound around the head drum (1) by approximately 220 degrees, and the stop mode is entered. Next, a method for determining the position and orientation of each tape guide that satisfies the stable tape running conditions will be described. It should be noted that positioning of the wrapping angle defining tape guides (26) (32), which are erected perpendicularly to the cassette mounting surface, is easy and will not be described further. In order to express the running state of the tape mathematically, we replace the tape with a one-dimensional video track center line VTC as shown in Figure 8, and create three unit vectors perpendicular to each other on vTC, a tape running direction vector D, and a tape width direction. Consider vector W and tape thickness direction vector 〒. The basic coordinate system (xyz) is set at the VTC separation point So of the tape in the head drum (1) as shown in FIG. 9(a). Nao xy flat i′! 1 is a plane parallel to the cassette mounting surface, and the xyz axes are the tape traveling direction vector Do in So.
, respectively coincide with the thickness direction vector To and the width direction vector WO. Below, the position, tilt angle, and
All tilt directions are xyzl! We will aim at the target. A local coordinate system (xyz) is introduced at the VTC entry and exit points of each tape guide. All Y axes of the local coordinate system are tape thickness direction vectors T at their origin. Regarding the X and Z axes, the y axis may coincide with the tape traveling direction vector D, and the Z axis may coincide with the axial direction vector VA of the guide. The radius of each guide and head drum is represented by R1, the wrapping angle of the tape is represented by ω, the angle at which the axial center forms the two axes of the basic coordinate system is represented by I, and the inclination direction of the axial center is represented by G. However, regarding the tilt direction G, the X-axis direction is taken as 00, and the counterclockwise direction is taken as the positive direction. The above symbols include S for the head drum (1), E for the erase head (25), and E for the tape guide (
24+ i is 6, and hereafter a subscript from 5 to 1 is given for each tape guide lined up along the tape transition path. Further, the distance between the tape separation point and the tape incidence point of the tape mounted between the head drum (1) and the guide (24) and between each guide is represented by L, and the tape transition path among the guides at both ends of the tape is represented by L. The above reference numeral representing the guide farther from the head drum is used as a subscript. Hereinafter, calculations are performed sequentially from the head drum (1) to the tape guide (32). [1] Each coordinate on the head drum The tape is wrapped around the head drum (1) at a lead angle LA, and the head is wound so that the tape traveling direction vector Do is parallel to the cassette mounting surface at the tape separation point SO. The drum (1) is tilted by LA around the y-axis (
(See Figure 9(b)). ■ Head drum tape separation point coordinates S. So is expressed by the following formula in xyz coordinates. 5o-(0,0,0) (1) Next, in FIG. 10, the tape incidence point coordinates Sl. In order to determine the video head rotation center coordinate SC and the X reference point Sx, consider a coordinate system xYZ obtained by rotating the xyz coordinate system LA around the y axis at So. In the XYz coordinate system, two axes 1 are parallel to the center axis of the head drum. ■ Tape incident point coordinates Sl (see Figure 10) Sl =
= (-R85inωo, R3-Rscosω5゜R
5ω5tanLA )o(-LAI y (2) Here, ()o indicates that the coordinate values in parentheses are the values in the XYz coordinate system.Hereafter, xI Yl "I +X2Y2Z2, etc. are the values calculated in each coordinate system. To show that ()1,
Use display method such as ()2. 1:LA], indicates the coordinate transformation matrix, the subscript y
indicates y-axis rotation, and the value in [ ] indicates the rotation angle. Coordinate transformation is used to convert values obtained in the local coordinate system to the xyz basic coordinate system. The coordinate transformation Ml-IJ Socks is expressed as follows. ■ Video head rotation center Sc (see Figure 10) Sc
−(0,Rs,R3ωctanLA)o (LAly
t6) However, ω. is the rotation angle from the tape separation point of the video head to the video track center. ■ X reference point Sx (control head position reference point) Sx'' (R85inωo, R5-R8CQSω0゜R5ω5tanLA).C-LAIy (7) ■ So
X value X at. Xo-2R5ω8/CQSLA-2Rs (ω5-ω0
) CO5LA (8) Here, ω0 represents the tape overlap angle on the head drum exit side. [2] Each vector no-(1, 0, 0) (9) Wo = (0, 0, 1) (10) To-(0, 1', O) [11] [3] Each vector DI −(cosLA, O, −5lnLA) + at the head drum tap incident point S+
M+ (12) W+ −(5lnLA, O, cosL
A)+M+ f13)T1-(0,1,O)+M+
(14) Here Ml-[-ωs)z[-LA]y[
4] The axis vector VAsVAs of the head drum is equal to the two axes of the xyz coordinate system VAs-(0,0,1)o[t,A)y05)
The axis vector of each guide is a unit vector. The axial vectors of the tape guides (24) (21+ +22+) and the erasing head (25) shall be inclined parallel to the width direction vector of the tape guided from the head drum side to each tape guide or erasing head. 5] Each coordinate on the tape guide (24) (see Figure 11)■ Tape separation point P2 R2= -La X D+ 10S+ (16)■ Guide center point Q6 Qa = R6 The coordinates are defined as the intersection of the guide axis and the plane perpendicular to the guide axis passing through the guide's tape separation point. ■ Tape incidence point P3 P3= (-R6slnω6u6 R6CO3ωa,,
0) 2[LA]yM, + R2f18) [6] Each vector R3-(1, O, O)3M3 (19) W3-(0,0
,1)3M3 120)T3-(0,1,O)3M3
f21) where M3 = [-(d6)Z(LA)yM
. [7] Axis vector VA6vA6 of tape guide (24)
-W1 (22) From the axis vector ■A6, the angle between the tape guide (24) and the two axes ■ and the inclination direction G can be determined by the following formula. (23) [8
]Each coordinate on the erase head (25) (see Figure 11)■
Tape separation point P4 R4= -LE XD3 + Pa f25)■ Erasing head tip R center point QE QE= RE
cosωE, O)4M3+P4(271

[9] Each vector at the tape incidence point P5 of the erase head (25) is -(1, O, O) sMs (28) W5 - (0, 0, 1) sMs (29) Ts = (0, 1
, 0)5M5 (30) where M5-[-ωE]ZM3 [10] Elimination head (25) axis vector vAE, inclination angle IE. Tilt direction GE VAB = VA6f31) IE-I6 (3'2) GE = Ga f331 [11] Each coordinate on the tape guide (21) (see Figure 11) ■ Tape release point P6 R6 = -R5XD5 +Ps (words) ■ Guide center point Q6 Qa = -R5XT5 +P6 f35) ■ Tape incidence point P7 R7 = (, R55lnω5 + -R5+R5COB
ωs, O) aM 5+ P a (36) [12] Each vector D7 at the tape incidence point P7 of the tape guide (21) = (1,0,0)7M7 (37) W? −(0, 0
,1)7M7 f38jT7−=(,o ,1 ,O
)7M7 (39) Here, Ml-[0532M5 [13] Axis vector VA5. of the tape guide (21). Tilt angle T5 + Tilt direction G5 VA5-VA6 (40) I5 = = Ia (41) G5-66 (42) [14] Each coordinate on tape guide (n) (see Figure 11) ■ Tape separation point P8 Ps = -L4
ω4 , O)8M7 +P8 (45) [15] Each vector D9-(1,0,O)9M9 (46)Ze, = (0,0
, 1) 9M9 147) Tg - (0, 1, O) 9 M
9 14B) Here, M9-[043M7 [16] Axis vector VA4 of tape guide (22). Tilt angle I4, tilt direction G4 VA4 = VA6 I49) I4=Ie (50) Ga=Ga (51) The tape running direction is changed by the tape guides (23) and (31). The inclination direction of the tape guide (23) is within the I9 Z9 plane under the condition that the tape does not twist. The inclination angle of the tape guide (23) with respect to the tape guide (22) is Ih. [17] On the tape guide (23) Each coordinate (Fig. 12,
(See Figure 13) ■ Tape separation point Pa Pa = L3
3゜-R2O3tan Ih)a (Ih)y Mg
+Pa (54) [18] Each vector Db at the tape incidence point Pb of the tape guide (23) = (cosIh, O, s Ih)bMb i
55'W4) = (-slnIll, 0, cos
Ih )b Mb i56' iTb = (0, 1, O
)bMb;57'where Mb = Cω33z (I
h)y M9 [19] Axis vector VA3 of tape guide (23), tilt angle I3r tilt direction G3 vf3-(0,0,1)a[:ih)yM9(581
13=cOs' (2 components of VA3) (59) For tape guides (24) to (23), sequentially determine the tape wrapping angle for each guide, tape length between guides, inclination angle, etc. The coordinate values, vectors, etc. related to each guide can be calculated using the calculation formulas shown above. Regarding the tape guide (31), the tape winding angle, inclination angle, and inclination direction are determined based on the data given to each guide and the stable running conditions of the tape (see Fig. 14).
. The tape guide (32) is perpendicular to the cassette mounting surface. The two axes of the coordinate system (XeYe Ze) at the tape separation point Pe of the tape guide (32) are perpendicular to the cassette mounting surface. The two components of the vector determined in this coordinate system are equal to those determined in the xyz coordinate system, which is the basic coordinate system. To set the tape winding angle ω2 and inclination angle I4 of the tape guide (31), the tape separation point P of the tape guide (31) is set.
Each vector at c is expressed in the XeYeZe coordinate system, and the fact that its two components are equal to the Z component of each vector at the tape incidence point Pb of the tape guide (23) is utilized. [:20] Tape kite (31) in the Xe Ye Ze coordinate system, each vector (14th
(See figure) Dce −(cos12.0.5inI2)C[-ω2
1z[:hly (611Wce = (5blI2
+ 0 +CO5I2 )C(-ω212(I2:IY
162'Tce -(0,1,0)c(-ω2J Z
(I 2. IY iG3! [21] Tape guide (3
1) Tape wrapping angle ω2. and inclination angle I2 (see Figures 14 and 15) Db = Dc, Wb = Wc, Tb = Tcxy
The plane and the XeYe plane are parallel. Therefore, Z component of Dce = 2 components of Db Z component of Wee = Z component of Wb - 2 components of Tce = 2 components of Tb. From formulas (61), (62), and (63), (11ω+) sin I 2 cos I 2-(D
b (7) Z component) (U) sin2I2cosω2
+cos2I 2 = (Z component of Wb) 165) s
in I 2 sin ω2-(2 components m of Tb> (66
)Dl), Wb, Tb 17) Each of the two components is +55
) +56) (determined by formula 59. (641+651 (From formula 661, I2 and ω2 can be determined by the following formula. 1 - (2 components of Wb) 1 2 = (Z component of Db) - (2 components of Tb ) (Wb(7) Z component) cosJ2 [22] Tape guide (311O each coordinate ■ Tape separation point PC Pc = -R2Db 10 p1) (69) ■ Guide center point Q2 Q2 = R2Tb + Pa +70) ■ Tape guide ( 31) inclination angle Ii i for (23) = I2
-th (711 pc Pd vector -VPcd VPcd = (R21! stone ω2 + -R2+ R2
(Isω2.-R2O3tanI+)c (Ii)yMb (72
1 ■ Tape incidence point Pd p (1 = VPcd + Pc) [23] Tape length between tape guides (23) (31) R2 Two components of Pd = 0 from the height condition of tape stable running condition (69) +72) From the r/31 formula, [24E T-pffi1' (3□) (DT-1h launch point Pd"'r (7) each, i vector Dd - (CO3I2 z O, 5inIz) d Md
i) Wd=(-廁■2,0.fishI2)dMd (a)
Td-(0, 1, OM-Md quotient where Md=[ω2)z (If ly Mb[25
] Axis vector VAz inclination direction 2 of tape guide (3I) VA2-(0, 0, 1)c (If)y Mb (78
By performing one or more calculations, a tape running system that satisfies stable running conditions can be determined. In the conventional new U loading mechanism, even if you try to define the position and orientation of each tape guide using the calculation method described above, the position of the tape guide is the head. Since the tape was restrained near the drum, it was not possible to satisfy the tape stable running conditions, but this became possible for the first time with the adoption of the tape loading mechanism according to the present invention. The radius R5 of the head drum (1) is 20 mm, and the lead angle L
A is 4.885°, the wrapping angle ωS of the tape on the head drum is 221°, the overlap angle ω0 on the head drum exit side is 5°, and the radius of each tape guide is R6, R5, R4.
, R3, R2, and R1 are 3 mm, 4 mm, and 2 mm, respectively. 3 wn, '2 rrtm, and 2 rrtm, calculations were actually performed using the above method. According to it, for example, the inclination angle of the tape guide (support) ■
4 was approximately 9.1°, the inclination angle of the tape guide (31) was approximately 7.2°, and the wrapping angle ω2 of the tape around the tape guide (31) was approximately 127°. (25) may be provided inside the second tape pull-out means as shown in FIG. The tape guide (31) is tilted and fixed on the adjustment stand (5) whose fixed position is adjustable, making it possible to finely adjust the running state of the tape. In the tape loading mechanism shown in FIG. The method for determining the position and orientation of each tape guide can be determined mathematically using coordinate transformation as described above, so it is omitted here, but according to the calculation results for the same input data as above. , the wrapping angle of the tape with respect to the leading second tape guide (31) is approximately 167°, which is larger than the approximately 127° calculated for the tape loading mechanism shown in FIG. 1. Therefore, the running resistance of the tape is Although the embodiment shown in FIG. 1 is preferable in order to reduce the amount of noise, the embodiment shown in FIG. 7 is advantageous in that it can provide a larger space for arranging the full-width erase head (25).

[Brief explanation of the drawing]

Fig. 1 is a plan view of the tape loading mechanism in the unloading state, Fig. 2 is a plan view of the same in the loading state, Fig. 3 is a perspective view of the tape pull-out means, and Fig. 4 is a sectional view of the guide body. , FIGS. 5(a) and 5(b) are side views of the first moving body before and after crimping, and FIGS. 6(a) and 6(b), respectively.
) are respectively plan views of the lever pull-out mechanism before and after the pull-out mechanism, FIG. 7 is a plan view showing another embodiment, FIG. 8 is an explanatory diagram of vectors representing the tape running state, and FIG. 9 (a+ is ( xyz) An xy plane diagram showing the arrangement of the head drum and each tape guide in the basic coordinate system, Figure 9(b) is a side view of the head drum, and Figure 10 is an xy plane in the (Xyz)o local coordinate system. Figure 11 is an xy plan view in the (xyz)20-cal coordinate system, Figure 12 is an xy plan view in the (XYZ)9 local coordinate system, and Figure 13 is an xy plan view in the (xyz)a local coordinate system. xy plan view, Fig. 14 is an xy plan view in (xyz)e local coordinate system, Fig. 15 is (xy z)
16 is a plan view showing a conventional example, and FIG. 17 is a plan view illustrating tape height conditions. (1)... Head drum (2)... First tape guide (20)... First moving body (21)... Leading first tape guide (22)... Leading first tape guide (23)... Trailing first tape guide (3)... Second tape guide (30)... Second moving body (31)... Leading second tape guide (8)... Tape withdrawal means

Claims (1)

[Claims] ■ The head drum (1) is installed at an angle equal to the winding lead angle LA of the tape with respect to the perpendicular to the cassette mounting surface, and the magnetic tape (9) is pulled out from the tape cassette (go). In the tape loading mechanism, the tape is wound spirally onto the head drum while being raised at a lead angle LA.
A tape pull-out means is provided, and the first tape pull-out means lifts the plurality of cylindrical first tape guides (2) provided on the first moving body (2O1) and the head drum ( 1) The first part that is moved along the outer periphery
a driving body, and the second tape drawing means comprises a second moving body (
one or more cylindrical second tape guides including one tape guide fixed to (30) and the second moving body (30) along the moving path of the first moving body (20) and a second driving body that moves the tape guide (2) and the second moving body (3) in a direction away from the head drum.
0) The upper tape guides are located in the respective cassette notches (91) in the unloading state, and in the loading state, the central axis of each tape guide is located at the head drum. The first tape guide (2), which is in a plane parallel to the surface of the tape to be guided and which is closest to the tape transition path among the second tape guides (3), is not twisted toward the tape guide from the side. The leading second tape guide (31) near the guide (31)
The running direction of the tape (9b) away from the head drum (1) is parallel to the cassette mounting surface, and the tape surface is inclined so as to be perpendicular to the cassette mounting surface. A tape loading mechanism characterized by being located at the same height as a take-up reel and at a position where this height can be maintained. In the loading state, the leading first tape guides excluding the most trailing tape guide (23) among the first tape guides 2) The trailing first tape guide (23) is inclined in the direction of a tape width direction vector that is perpendicular to the tape running direction, and the trailing first tape guide (23) is aligned with the width direction vector of the tape (9d) running between it and the leading first tape guide. A tape loading mechanism according to claim 1, which is parallel or inclined in the direction of a composite vector of said vector and a vector directed along said tape (9d) towards the preceding first tape guide. ■ The first tape guide (2) has three tape guides (2
1) The tape loading mechanism according to claim 1 or 2, which consists of (22+(23)). ■ The leading second tape guide (31) moves parallel to the skein/gutter mounting surface. Claims 1 to 3 are tape guides fixedly installed on the second moving body (30).
The tape loading mechanism according to any of paragraphs. ■ The leading second tape guide (31) is a tape guide provided on the chassis at a predetermined angle of inclination with respect to the skein/gutter mounting surface, and is a tape guide fixed on the second moving body (30). is perpendicular to the cassette mounting surface in the loading state, and defines the wrapping angle of the tape with respect to the leading second tape guide (31).
The tape loading mechanism according to any of paragraphs.