JP2669062B2 - Tape loading mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The tape loading mechanism of the present invention will be described according to the following items.

A. Industrial application fields B. Summary of the invention C. Prior art "FIGS. 11 to 13" D. Problems to be solved by the invention E. Means to solve the problems F. Examples [1. Figures to 10] a. Reel base, rotating head drum [FIGS. 1 to 6, 9] b. Tape loading mechanism [FIGS. 1 to 9] b-1. Loading block and folding guide Post b-2. Loading arm, cam gear, limiter spring [Fig. 3, Fig. 5 to Fig. 9] b-3. Slider c. Capstan, etc. [Fig. 1, Fig. 2, Fig. 4, Fig. 5] d. Tape loading operation and tape path [FIGS. 3 to 5] d-1. Operation [FIG. 3] d-2. Positional relationship between the folded guide post and the rotary head drum [FIG. Fig. 5] e. One example of applicable conditions [Fig. 10] G. Effects of the invention (A. Industrial application field) On-loop loading mechanism. More specifically, the present invention relates to a tape loading mechanism of a magnetic recording / reproducing apparatus such as a digital tape recorder in which a wrap angle of a magnetic tape with respect to a head drum is relatively small. A pair of return guide posts that are positioned in the tape pull-out recess and are moved from the state to an opposite position across the head drum to wind a part of the magnetic tape around the head drum; By devising the positional relationship of the post with respect to the head drum, the oblique guide post, which was conventionally provided in the vicinity of the return guide, becomes unnecessary, and the positional flexibility of the return guide post is increased to reduce the size and the size of the device. The cost can be reduced.

(B. Outline of the Invention) The tape loading mechanism of the present invention pulls out a part of the magnetic tape wound around the tape reel in the tape cassette from the tape pull-out surface, and has a predetermined rotation axis in the axial direction of the tape reel. A tape loading mechanism having a pair of return guide posts for winding the head drum at an angle of less than 180 ° on an angled head drum, wherein the tape contact surface of the return guide post starts tape winding on the head drum during tape loading. Positioning the folded guide post so as to be in contact with the reference line including the tangential direction vector at the position and the tape winding end position, thereby forming a tape path without providing an inclined guide post near the folded guide post. , Expanding the degree of freedom in position of the folding back guide post to reduce tape damage Rutotomoni are those which make it possible to reduce the size of the apparatus and simplifying the structure of the tape loading mechanism and cost reduction, and the like.

(C. Prior art) [Figs. 11 to 13] As one of the tape loading methods adopted in video tape recorders or digital audio tape recorders, "M-type loading" suitable for downsizing and mass production of the device A so-called inclined guide post for winding a magnetic tape around a rotating head drum provided at a predetermined angle with respect to a reference surface of a mechanical chassis and running the tape is essential. .

11 to 13 show an example a of such a tape loading mechanism.

Reference numeral b denotes a rotary head drum rotatably supported in a state of being inclined at a predetermined angle with respect to a reference plane π of a mechanical chassis (not shown). The rotary head drum b has a predetermined wrap angle on the outer peripheral surface of its front half. The magnetic tape c is wound around.

d and d 'are tape loading blocks whose movement paths are defined by guide elongated holes e and e' and are moved by means (not shown). The tape loading blocks d and d 'are inclined. Guide posts f, f 'and turn-back guide posts g, g' vertically provided with respect to the mechanical chassis are provided, respectively.
The folding guide posts g and g'include roller members h,
a pair of upper and lower flanges i, i, i ', so as to sandwich h'
i'is provided.

During the tape loading, the tape loading blocks d and d 'are moved from the position indicated by the two-dot chain line in FIG. 11 (hereinafter referred to as "non-loading position") to the position indicated by the solid line in FIG. Position "), whereby the magnetic tape c is pulled out of the tape cassette j by the folded guide posts g and g '. That is, the magnetic tape c ejected from the supply-side reel k has its tape surface parallel to an axis perpendicular to the reference plane π of the mechanical chassis (hereinafter referred to as "reference axis" and represented by "MM"). After being wound around the fixed guide post or ten leg pin in a suitable state, it is wound around the folded guide post g with a predetermined wrap angle, and the upper flange i restricts the movement of the magnetic tape c in the width direction to a predetermined range, and One side edge of the magnetic tape c is brought into contact with the lead l of the rotary head drum b by the guide post f, is twisted along the lead l, and is wound around the rotary head drum b with a predetermined wrap angle.

The magnetic tape c separated from the rotary head drum b
After being wound around the inclined guide post f ', it is folded back by the folded guide post g', and the upper flange i 'regulates the movement of the magnetic tape c in the width direction.
Stable tape running is ensured, and the tape surface again becomes substantially perpendicular to the reference surface of the mechanical chassis, and then reaches the take-up reel m.

(D. Problems to be Solved by the Invention) In the tape loading mechanism a by the M-type loading method as described above, the tape loading block d moved to the left and right sides of the rotary head drum b during tape loading; Inclined guide posts f and f'are provided on both d '.

The inclined guide posts f and f 'have a function of compensating for the movement of the tape center line which occurs when the magnetic tape c is wound around the inclined rotary head drum b, thereby ensuring stable tape running. However, the presence of the inclined guide posts f and f 'uniquely determines the positions of the folded guide posts g and g', which is a constraint on design. This is a serious problem in a device such as a digital audio tape recorder aiming at cost reduction. Further, increasing the tape damage by providing a fixed guide post such as an inclined guide post is not preferable for speeding up the tape running.

(E. Means for Solving the Problems) In order to solve the above-described problems, the tape loading mechanism of the present invention is configured such that when a tape cassette is mounted on a device, a pair of folded guide posts are relatively taped. The magnetic tape is wound around the head drum by being positioned inside the drawing surface and being moved from the state to the opposite position across the head drum, and the winding angle is relatively small. In a tape loading mechanism of a magnetic recording / reproducing apparatus, which is made at an angle, the tape contact surface of the folding guide post includes a tangential direction vector at a tape winding start position and a tape winding end position on a head drum during tape loading. The folding back guide post is arranged so as to be in contact with the reference line.

Therefore, according to the tape loading mechanism of the present invention, the importance of the inclined guide post in the tape path system is low.
That is, when the wrap angle of the magnetic tape with respect to the inclined guide post is small and the twist of the tape is small,
The tape contact surface of the folded guide post is a line segment connecting the magnetic tape winding start (or end) position on the head drum and the tape winding start (or end) position on the head drum side of the conventional inclined guide post. As long as it is positioned on the extension, the position of the folded guide post with respect to the head drum can be designed to some extent freely, so that the inclined guide post is not required, the device is reduced in size, the cost is reduced, and the tape is reduced. It is possible to reduce damage.

(F. Embodiment) [FIGS. 1 to 10] Hereinafter, details of the tape loading mechanism of the present invention will be described with reference to the illustrated embodiments.

In the illustrated embodiment, the tape loading mechanism of the present invention is applied to the tape loading mechanism 1 in the R-DAT.

(A. Reel base, rotating head drum) [FIGS. 1 to 6
FIG. 9, FIG. 9] 2 is a mechanical chassis, 3 is a front part of the mechanical chassis 2 (a downward direction in FIG. 1 is a front side, and an upward direction is a rear side. The direction toward the left is defined as the left side, and the direction toward the right is defined as the right side.
The sub-chassis is disposed so as to face in parallel from below, and two support shafts 4 and 4 ′ are erected from a position spaced apart in the left-right direction of the sub-chassis 3. The reel bases 5, 5 'are rotatably supported on the reel bases. One of the reel stands 5, 5 'is an S (supply side) reel stand, and the other 5' is a T (winding side) reel stand.

Reference numeral 6 denotes an upper drum rotary type rotary head drum (having a drum diameter of R (m
m). ), A lower drum 6a fixed to the mechanical chassis 2, an upper drum 6b rotatably supported by the lower drum 6a, and an outer peripheral portion of a gap between the lower drum 6a and the upper drum 6b. It is composed of magnetic heads 6c, 6c, etc. which are located at the position and rotate integrally with the upper drum 6b. As shown in FIG. 5, the rotary head drum 6 has an angle at which the rotation axis 6d is with respect to the reference axis MM (hereinafter, this angle is referred to as a "drum inclination angle", and is denoted by a symbol "θ _D ". Is shown). Further, the lower drum 6a is formed with a lead 7 for supporting a lower side edge of the magnetic tape, and the lead 7 has a predetermined angle () with respect to a plane whose normal is the rotation axis 6d of the rotary head drum 6. Hereinafter, this angle is referred to as a “lead angle” and is represented by a symbol “θ _L ”. The angle θ _L is the still angle (the running direction vector of the magnetic tape and the moving direction vector of the magnetic head when the tape is stationary) Angle
Is equivalent to

(B. Tape Loading Mechanism) [FIGS. 1 to 9] Next, a main part of the tape loading mechanism 1 will be described.

(B-1. Loading Block and Folding Guide Post) Reference numerals 8 and 8 ′ are guide elongated holes, which are located on the left and right opposite sides of the rotary head drum 6 and have a substantially inverted V shape when seen in a plan view. Thus, the mechanical chassis 2 is formed.

9 and 9 'are loading blocks which are slidably supported by the guide slots 8 and 8', respectively. That is, one loading block 9 serves as an entrance block for drawing out the magnetic tape 12 on the S reel 11 side of the tape cassette 10 during tape loading, and the other loading block 9 'pulls out the magnetic tape 12 on the T reel 11' side. The block is on the outlet side, and its moving path is defined by the guide elongated holes 8 and 8 ', respectively.

The loading blocks 9, 9 'have folding guide posts 14, 14' supported on their moving bases 13, 13 '. The folding back guide posts 14 and 14 'are shafts.
Upper flange 16, 16 'and lower flange inserted through 15, 15'
The roller members 18, 18 'are sandwiched between the roller members 17, 17', and the lower flanges 17, 17 'are formed with threaded portions 17a, 17'a projecting from the lower surface thereof. Further, the moving bases 13 and 13 'are provided with insertion holes 13a and 13' formed therein.
The lower ends of the cylindrical support members 19, 19 'are press-fitted and fixed to a, whereby the support members 19, 19' are erected vertically on the moving bases 13, 13 '. Then, screw portions 17a and 17'a formed on the lower flanges of the folding back guide posts 14 and 14 'are screwed into screw holes 19a and 19'a formed in the central portions of the support members 19 and 19', respectively. As a result, the folding guide posts 14 and 14 'are attached to the support members 19 and 19. Grooves 19b and 19'b having a smaller diameter than other portions are formed in the portions of the support members 19 and 19 'near the one end on the side of the counter screw holes 19a and 19'a. Is engaged with the guide elongated holes 8 and 8 ', so that the movable bases 13 and 13' are slidably supported along the guide elongated holes 8 and 8 '.

Reference numerals 20, 20 'denote protrusions formed at positions near the rear end of the contact surfaces of the movable bases 13, 13' with the mechanical chassis 2, and
The projections 20, 20 'cause the movable bases 13, 13' to assume a slightly inclined posture toward the front (see FIG. 6), whereby the axes AA,
A'-A '(only the AA axis is shown in the figure) is tilted several degrees with respect to the reference axis MM.

Reference numerals 21 and 21 'denote recesses formed by cutting the rear ends of the movable bases 13 and 13' in a V-shape. When the tape loading is completed, the mechanical chassis 2 is positioned near the rear ends of the guide slots 8, 8 '. The stoppers 22 abut against the cylindrical stoppers 22, 22 ′, respectively, which are erected on the movable bases 13, 13 ′.
Movement of the loading block 9 is restricted.
The 9 'loading completion position is defined.

Reference numerals 23 and 23 'are insertion holes formed at positions near the front ends of the moving bases 13 and 13'.

Reference numerals 24, 24 'denote guided pins, the upper ends 25, 25' of which are smaller in diameter than other portions, and these are guide elongated holes 8,
8'through the insertion holes 23 of the moving bases 13 and 13 ',
23 ', the mounting screws 26, 26' are screwed into screw holes 25a, 25'a formed in the upper ends 25, 25 ', and the upper ends 25, 25' , 13 'support members
Together with 19, 19 ', they are slidably engaged with the guide elongated holes 8, 8'.

(B-2. Loading Arm, Cam Gear, Limiter Spring) [FIGS. 3, 5 to 9] Reference numerals 27 and 27 'denote loading arms, each of which comprises two rotatable arms rotatably connected to each other. Become.

Reference numerals 28 and 28 'denote first rotating arms, each having an elongated plate shape, to which one end is fixed with an upper end of a coupling sleeve 29, 29' having a substantially sleeve-like upper portion having a larger diameter than the lower portion. Small spring contact pins 28a and 28'a project downward from a position near one end of a side edge located in a counterclockwise direction when viewed from above.

Reference numerals 30 and 30 'denote second pivot arms, each having a length substantially equal to that of the first pivot arms 28 and 28', and one end of which is the first pivot arm.
Are rotatably connected to the other ends of the rotating arms 28, 28 'by connecting pins 30a, and the guided pins 24,
24 'is fixed.

Reference numerals 31 and 31 'denote support shafts suspended from the lower surface of the mechanical chassis 2, and these support shafts 31 and 31' are separated from each other on the left and right opposite sides across the front ends of the left guide slots 8 and 8 '. The connecting shafts 29, 29 'fixed to the first rotating arms 28, 28' are rotatably fitted onto the supporting shafts 31, 31 '.

Thus, the loading arms 27, 27 'are rotatably connected to each other by two rotatable arms 28, 28' and 30, 3 '.
When the first rotating arms 28, 28 'are rotated, the loading blocks 9, 9' are guided by the second rotating arms 30, 30 '. It will be moved along the holes 8, 8 '.

Reference numerals 32, 32 denote cam gears, upper portions 33, 33 each having a relatively thin disk shape, and a disk shape having a thickness larger than the thickness of the upper portions 33, 33, and having an outer diameter that is one turn from the upper portions 33, 33. Small bottom 3
4, 34 and two spring contact projections 35a, 35b and 35a, 35b respectively protruding from the upper surfaces of the upper parts 33, 33 are integrally formed of synthetic resin, and two places 36 on the outer peripheral surface of the upper parts 33, 33, 36 and
37, 37 are formed on a flat cam surface positioned so as to form a substantially C shape when viewed from the axial direction, and tooth portions 38, 38 are formed on a part of the outer peripheral surface of the lower portions 34, 34, The teeth 38, 38 are cam surfaces
It is formed in a range substantially corresponding to the portion between the tips 36a, 36a and 37a, 37a in the direction in which the intervals between 36, 36, 37, and 37 become smaller.

Therefore, when the cam gears 32, 32 are viewed from above, the two cam surfaces 36, 36 and 37, 37 are located on both sides of the teeth 38, 38.

Incidentally, one spring abutting protrusion 35a, 35a is arranged in a portion of the outer peripheral portion of the upper portion 33, 33 which is located in an eaves shape with respect to the teeth 38, 38, the other spring abutting protrusion 35b, 35b is an upper portion. It is disposed slightly clockwise from the part opposite to one of the spring contact protrusions 35a, 35a with the center of 33 interposed therebetween.

The cam gears 32, 32 have their central portions inserted into insertion holes 39, 39, which are provided in the axial direction.
The lower portions of the coupling shafts 29 and 29 'fixed to the first and second rotation arms 28 and 28' are coaxially and rotationally inserted into the rotation centers of the first rotation arms 28 and 28 '. Can be freely combined.

With this, the spring contact pins 28a, 28'a of the first rotating arms 28, 28 'and the spring contact protrusions 35a, 35 of the cam gears 32, 32 are formed.
It will be located at the same height as a, 35b, 35b.

Further, the insertion of the coupling shafts 29, 29 'into the insertion holes 39, 39 is carried out by the spring contact pins 28a, 28'a of the first rotating arms 28, 28' to the cams of the spring contact protrusions 35a, 35a on one side. This is performed so as to be in a state between the end face on the surface 36 side and the other spring contact protrusions 35b, 35b.

Numeral 40 denotes a limiter spring having a scissor-shaped spring shape. The coil portions 40a, 40a are externally fitted to the large-diameter portions of the coupling shafts 29, 29 ', and one end of one of the arms 40b, 40b is a cam gear. 3
2 and 32, one of the spring contact projections 35a, 35a is elastically contacted with the end surface on the counterclockwise direction, and the other arm 40c, 40c has the tip end of the first rotation arm 28, 28 '. The end faces 28a and 28'a on the clockwise side are elastically contacted.

Therefore, the cam gears 32, 32 and the first rotating arms 28, 28 '
And the spring contact pins 28a, 28'a and the other spring contact protrusion 35b,
While no pressing force is applied in a direction to separate the spring contact pins 35a from the other 35b, the spring contact pins 28a and 28'a are pressed against the other clockwise end faces of the spring contact projections 35b and 35b, As a result, the first rotating arms 28, 28 'and the cam gears 32, 32 are integrated.

(B-3. Slider) 41 is a slider for rotating the cam gears 32, 32 and moving a pinch roller lever and the like described later.

The slider 41 has a substantially rectangular plate shape that is long in the left-right direction, a rear end surface 42 is formed on a substantially flat surface that extends straight in the left-right direction, and a middle portion of the rear end surface 42 and a lower portion near the left end. A relatively short rack section 4 that extends in the left-right direction from
3, 43 are protruded horizontally, and a notch recess is provided at a position corresponding to each of the rack portions 43, 43 in the upper portion of the rear end surface 42.
44, 44 are formed.

And such a slider 41 has its guided slot 4
The guide pins 46, 46, which are erected from the sub-chassis 3, are slidably engaged with the 5, 45, ..., so that the guide pins 46, 46 are movable in the left-right direction within a certain range. At the same time, it is moved in the left-right direction by a drive mechanism (not shown).

(C. Capstan and others) [Figs. 1, 2 and 4
FIG. 5, FIG. 5] A capstan housing 47 is provided upright on the upper surface of the mechanical chassis 2 at a position slightly obliquely forward of the head drum 6 and a capstan shaft 48 is mounted on the capstan housing 47. It is rotatably supported.

Reference numerals 49 and 50 are fixed guide posts fixed to the upper surface of the mechanical chassis 2, 49 is provided on the inlet side, 50 is provided on the outlet side, and 51, 51,... Are the tape cassettes 10 (see FIG. 1). ) Are cassette positioning pins that are removably mounted.

Reference numeral 52 denotes a pinch roller for moving the magnetic tape 12 at a constant speed in cooperation with the capstan shaft 48, and an end of the pinch roller lever 53 rotatably supported by the mechanical chassis 2 on the side opposite to the center of rotation. It is rotatably supported by a support shaft 53a which is erected from the section.

Reference numeral 54 denotes a ten-legged pin, which is provided at an end portion of the ten-legged arm 55 rotatably supported by the mechanical chassis 2 on the side opposite to the center of rotation. It is adapted to contact the tape 12.

Reference numeral 56 denotes a bending guide, which stands on the pinch roller lever 53 on the right side of the pinch roller 52.

In a state before the tape loading (hereinafter, referred to as an “initial state”), the pinch roller 52, the tension pin 54, and the feed guide 56 are in a non-loading position indicated by a two-dot chain line in FIG. Positioning pins 51, 51, ... Tape cassette mounted on
The tape 10 is held at a position relatively inside the tape pull-out recess 10a, and when tape loading is performed, each is moved to a loading completion position indicated by a solid line in FIG.

(D. Tape Loading Operation and Tape Pass) [FIGS. 3 to 5] Next, the tape loading operation by the tape loading mechanism 1 and the loading blocks 9 and 9 ′ are formed when the tape loading is completed. The tape path will be described.

(D-1. Operation) [FIG. 3] First, in the initial state of the above-described tape loading mechanism 1, as shown in FIG.
The right side of the notch recesses 44, 44 of the rear end surface 42 is in contact with the cam surfaces 36, 36 of the cam gears 32, 32, thereby preventing the rotation of the cam gears 32, 32, Loading block 9, 9'and second pivot arm
With the guided pins 24, 24 'connecting the first and second pivot arms 28, 28' and the second pivot, the first and second pivot arms 28, 28 'are in contact with the front ends of the guide slots 8, 8'. The arms 30 and 30 'are folded so as to form a substantially V shape.

Then, when there is a tape loading command after that,
Slider 41 moves to the right, and the slider
The racks 43 of the 41 move while meshing with the teeth of the cam gears 32, 32, so that the cam gears 32, 32
It is rotated in the counterclockwise direction integrally with 8 ', so that the loading blocks 9, 9'will be guided long holes 8,
8'moved along the recesses 21 of the moving bases 13, 13 ',
21 'contacts the stoppers 22 and 22' and reaches the loading completion position shown in FIG. 3 (B).

(D-2. Positional relationship between folding guide post and rotary head drum) [Figs. 4 and 5] Then, the position between the folding guide posts 14 and 14 'and the rotary head drum 6 in the loading completed state. The relationship is as shown in FIG. In FIG. 5, a reference circle 57 indicated by a broken line on the rotary head drum 6 corresponds to a running reference line 58 of the magnetic tape 12 (see FIG. 5). Further, in the figure, θ _R represents a drum wrap angle of the magnetic tape 12 with respect to the rotary head drum 6, a point P _s is a start point of winding of the magnetic tape 12 on the reference circle 57, and a point P _e is an exit side. The winding end point is shown, and the vectors _s and _e are points P _s and
The tangential direction vector at P _e is shown.

As can be seen, one of the folded guide posts 14
Is positioned so that its tape contact surface 14a is in contact with a reference line 59 that includes the tangential direction vector _s and extends diagonally to the left, and the other folded guide post 14 'has its tape contact surface 14'a in the tangential direction. It is located so as to be in contact with a reference line 60 that includes the vector _e and extends obliquely rearward to the right.
That is, the tape contact surface 14a, 14'a is conventional inclined guide starting with the head drum side tape winding in the post (or end) point and the point P _s, is positioned on the extension of a line connecting each of the P _e And these folded guide posts 14, 14 '
DOO point P _s, distance L _s between P _e, L _e is twisted magnetic tape 12 at the inlet and outlet ports of the rotary head drum 6 is a rapidly changing No such distance.

And, as described above, the folded guide post 14,
14 'is inclined toward the front ends of the guide slots 8 and 8'by the projections 20 and 20' formed on the moving bases 13 and 13 'that support them, whereby the folding back guide posts 14 and 14'. ′ Is erected along the reference axis MM to reduce tape damage due to the torsion of the magnetic tape 12.

Thus, as the tape path, the magnetic tape 12 protruding from the S reel 11 side is fixed guide post 49-ten leg pin 54-
The return guide post 14-the rotary head drum 6-the return guide post 14'-the fixed guide post 50-the capstan shaft 48 and the pinch roller 52-the feed guide 56 are sequentially wound and then formed to reach the T reel 11 '. .

(E. One example of applicable conditions) [FIG. 10] Next, regarding the conditions under which the tape path system by the tape loading mechanism 1 is possible, in the tape path system having the conventional inclined guide posts f and f ′, the inclined guides will be described. Consider the importance of the posts f and f '.
That is, the inclined guide post f of the magnetic tape c, as the wrap angle for f '(which is referred to as phi _R.) Is large, the role of the inclined guide post is important, also, inclination angle of the inclined guide post (i.e. , The angle formed by the central axis of the inclined guide post with respect to the reference axis MM, which is defined as φ _C. ), the greater the twist of the magnetic tape c in the vicinity of the entrance / exit of the rotary head drum b is considered to be. is, inclined guide post f, the importance of f 'is considered to increase (symbol phi _R, phi _C Figure 12 for, 13 see FIG things. Incidentally,
The symbols R, θ _R , θ _{L and the} like in these figures are used in the meanings described above. ).

FIG. 10 shows a conventional tape loading mechanism a
Drum inclination when drum diameter R = 30 (mm), drum wrap angle θ _R = 90 °, lead angle θ _L = 6 ゜ 22 ′, diameter r of inclined guide posts f, f ′ = 2 (mm) Angle θ _D
An inclined guide post f is a graph showing the calculation value the correlation between the wrap angle phi _R and inclination angle phi _C about f '.

As can be seen from the figure, the wrap angle φ _R is the drum inclination angle θ _D
Increase Decrease to go become accompanied to the (graph curve 61 refer.), The other inclination angle phi _C is gradually increased so with the increase of the drum inclination angle theta _D. (See graph curve 62).

Therefore, the applicable condition of the tape loading mechanism 1 in this case is that the drum inclination angle θ _D is in a range of about 7 to 8.5 °.

(G. Effect of the Invention) As is apparent from the above description, the tape loading mechanism of the present invention accommodates the tape reel wound with the magnetic tape and a part of the magnetic tape is the tape pull-out surface of the cassette case. The tape cassette is inserted through the head drum, and the head drum is provided with the rotation axis tilted at a predetermined angle with respect to the axial direction of the tape reel. When the tape cassette is mounted, the pair of return guide posts are relatively positioned inside the tape pull-out surface and are moved from the state to the opposite position across the head drum when the tape cassette is mounted. A tape loading mechanism, wherein the tape contact surface of the folding guide post is the tape on the head drum during tape loading. Characterized in that a folding guide post so as to contact the reference line including the tangential vector at the urging start position and the end tape wrap position.

Therefore, according to the tape loading mechanism of the present invention, the importance of the inclined guide post in the tape path system is low.
That is, when the wrap angle of the magnetic tape with respect to the inclined guide post is small and the twist of the tape is small,
The tape contact surface of the folded guide post is a line segment connecting the magnetic tape winding start (or end) position on the head drum and the tape winding start (or end) position on the head drum side of the conventional inclined guide post. As long as it is positioned on the extension, the position of the folded guide post with respect to the head drum can be designed to some extent freely, so that the inclined guide post is not required, the device is reduced in size, the cost is reduced, and the tape is reduced. It is possible to reduce damage.

In the above-described embodiment, an example in which flange portions are provided above and below the roller member as the structure of the descending guide post to restrict the movement of the magnetic tape in the width direction, the tape loading of the present invention is described. It does not mean that the folding guide according to the mechanism is limited to such a thing, and such movement regulation in the tape width direction may be left to another tape guide. The present invention can be implemented in various modes without departing from the technical scope.

[Brief description of the drawings]

The drawings show an example in which the tape loading mechanism of the present invention is applied to a tape loading mechanism in an R-DAT. FIG. 1 is a plan view of the whole, FIG. 2 is a perspective view of the whole, and FIG. 3 is a tape. It is a figure which shows a loading operation | movement, (A) is a top view of the principal part which shows the state of the loading block in the non-loading position, (B) is the state of the loading block in the loading completion position, and the return guide post and the rotating head drum. FIG. 4 is a plan view of an essential part showing the positional relationship between them, FIG. 4 is a schematic plan view of the essential part,
FIG. 5 is a side view of the main part showing the position of each guide post forming the tape path, FIG. 6 is a side view of the main part seen from an angle different from FIG. 5, and FIG. 7 is a tape loading mechanism. FIG. 8 is an enlarged perspective view showing an essential part of the tape loading mechanism, FIG. 8 is an enlarged perspective view showing a part of the slider and a cam gear separated from each other, FIG. 9 is a plan view showing an essential part of the tape loading mechanism, and FIG. FIG. 11 is a graph showing an example of application conditions of the loading mechanism, and FIGS. 11 to 13 show an example of a conventional tape loading mechanism having an inclined guide post.
FIG. 11 is a schematic plan view, FIG. 12 is a schematic plan view of a main part, and FIG. 13 is a side view of the main part. DESCRIPTION OF SYMBOLS 1 ... Tape loading mechanism, 6 ... Head drum, 6d ... Rotating shaft (of head drum), 10 ... Tape cassette, 11, 11 '... Tape reel, 12 ... Magnetic tape, 14, 14 ': folded guide post, 14a, 14'a: tape contact surface, 59, 60: reference line, θ _R: winding angle (with respect to head drum of magnetic tape), P _s: tape winding Start position, P _e ... tape winding end position, _s , _e ... tangential direction vector

 ────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Masao Oyama 6-735 Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation (56) References 62-180347 (JP, U) Actually opened 63-161442 (JP, U)

Claims (1)

(57) [Claims] A tape cassette in which a tape reel on which a magnetic tape is wound is accommodated, and a part of the magnetic tape is passed through a tape drawing surface of a cassette case; A head drum that is inclined at a predetermined angle with respect to the direction is provided, and the magnetic tape is wrapped around the head drum so that the winding angle is less than 180 ° when the tape cassette is mounted. A tape loading mechanism performed by a pair of return guide posts that are located inside the drawing surface and are moved from the state to an opposite position across the head drum, and a tape contact surface of the return guide post during tape loading. Touches the reference line including the tangential direction vector at the tape winding start position and the tape winding end position on the head drum. Tape loading mechanism characterized by foldback guide posts