JPH06208749A - Tape guide mechanism for magnetic recorder/player - Google Patents

Abstract

PURPOSE:To ensure stabilized linear running by arranging guides for forming a running path on the advancing side of tape closely such that the span Li of a tape stretched across the guides is shorter than 0.8 times of the tape width (h). CONSTITUTION:An input side roller guide 7 positioned most closely to a cylinder 5 has an upper flange for regulating the upper end position of a tape and a lower flange for regulating the lower end position of the tape. A tape 1 running while being regulated is subjected to bending force, as shown by an arrow M, between the cylinder 5 and the guide 9. In the tape path, a large number of guides are provided between the lead 5a of the cylinder 5 and the guide 9. Since the tape span Li is set shorter than 0.8 times of the tape width (h) (8mm) between respective guides, tilting deformation of running tape is retarded and the tape can run stably without being deformed significantly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape guide mechanism for guiding and running a magnetic tape in a magnetic recording / reproducing apparatus such as a VTR or a video camera, and particularly to a tape on the cylinder entrance side when a thin tape is used. The present invention relates to a tape guide mechanism that is suitable for preventing a sideways buckling and generating a stable traveling regulation state.

[0002]

2. Description of the Related Art As a tape guide mechanism of a magnetic recording / reproducing apparatus, there is, for example, a mechanism for an 8 mm video camera disclosed in Japanese Patent Laid-Open No. 3-152757. The magnetic recording / reproducing apparatus according to this prior application employs a cylinder / cassette overlap method in which the cylinder is inserted into the opening of the cassette when the loading is completed so that the cylinder is overlapped. An optimally arranged mechanism configuration is disclosed.

In the magnetic recording / reproducing apparatus as well as the above 8 mm video, it is generally necessary to manage the linearity of the video track recorded on the tape to a predetermined value or less in order to ensure compatibility with other devices. Is.

Therefore, the tape is pressed by the flange of the roller guide arranged in the vicinity of the cylinder into the tape running guide groove (hereinafter referred to as the lead) of the cylinder with a predetermined regulation force. The reaction force of the tape pressing regulation force on this lead is
It is received by the flange of the height regulating guide arranged on the tape path on the cassette side of the roller guide. Therefore, the tape is
It runs with the upper end sandwiched by roller guides and the lower end sandwiched by cylinder leads.

[0005]

In the above-mentioned running restriction state, the tape undergoes bending deformation in the width direction. Generally, when bending deformation in the width direction is applied to a member such as a video tape having an extremely small thickness dimension with respect to the width dimension, a bending deformation in the thickness direction occurs due to a difference in bending rigidity. In this state in which the taper deformation in the thickness direction occurs, the tape pressing regulation force on the cylinder lead becomes small, and it becomes difficult to secure a predetermined video track linearity.

In recent years, tapes have tended to be thinned to meet the needs for recording for a long time, and tapes having a thickness of 8 μm or less are being commercialized. This ultra-thin tape has a problem in that it is liable to be tilted and deformed in the thickness direction due to the decrease in rigidity, and the tape guide mechanism of the conventional magnetic recording / reproducing apparatus cannot keep the linearity of the video track below a predetermined value. .

It is an object of the present invention to secure a predetermined track linearity by stably pressing the tape against the cylinder lead even if the tape is an ultra-thin tape in which the tape is likely to fall over.
It is to provide a tape guide mechanism for a magnetic recording / reproducing apparatus.

[0008]

The bending moment load when the tape starts to fall and deform is given by the following equation.

[0009]

[Equation 1]

[0010] However, in the ^{formula, B = EIy = Eht 3/} 12 ......... y -axis of the flexural rigidity E: modulus of longitudinal elasticity, h: Te - flop width, t: te - flop thickness H = C-PIp / a .................. torsional stiffness of the cross section P: axial force (compression +, tensile -), a: cross sectional area ^{C = GIp = Ght 3/3} ......... z -axis of the torsional stiffness G: transverse elasticity Coefficient L: Tapespan.

If this equation is simplified, the following equation is obtained: M∝ht ³ / L.

According to the above equations and equations, it is understood that the amount of tape deformation due to the tape is influenced by the tape thickness t, the longitudinal elastic modulus E and the lateral elastic modulus G of the tape and the like. That is,
Compared to thick tapes, thin tapes with low rigidity tend to fall and deform. Furthermore, the amount of tilt deformation is the tape span L
Be affected by. Therefore, it is understood that the tape span L should be reduced in order to reduce the amount of tilt deformation.

Therefore, in the present invention, attention is paid to the tape span L, and particularly, on the cylinder entrance side where the tape is easily lifted from the cylinder lead due to the scanning force of the rotary head mounted on the cylinder, the tape path from the height regulation guide to the cylinder. The tape span between the cylinder and each guide at L
When the tape width is represented by i and the tape width is represented by h, the above-described object is achieved by the tape path configuration satisfying the relationship of Li ≦ 0.8h.

[0014]

As described above, the tape path structure may be such that the tape span Li between the cylinder and each guide in the tape path from the height regulating guide on the cylinder entrance side to the cylinder lead becomes smaller than the tape width h. For example, by narrowing the tape span, it is possible to make it difficult for the traveling magnetic tape to fall and deform. As a result, even if the magnetic tape is a low-rigidity thin tape, a stable running state without deformation can be ensured, so that the linearity of the video track recorded on the thin tape can be set to a predetermined value or less.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a tape path by a tape guide mechanism of a magnetic recording / reproducing apparatus according to an embodiment of the present invention.
In this example, an 8 mm video using an 8 mm wide tape will be described.

In FIG. 1, reference numeral 5 is a cylinder on which a magnetic head (not shown) is mounted. On the left side (inlet side) of the cylinder 5, 6 is an inlet-side first inclined guide (non-rotating guide) positioned closest to the cylinder, 7 is an inlet-side roller guide (rotating guide), and 8 is an impedance roller guide (rotating guide). Guides), 9 is an entrance side height regulation guide (rotation guide), 10 is an entrance side second inclined guide (non-rotation guide), 1
Reference numeral 1 is an entrance side fixed guide (non-rotating guide), 12 is a tension guide, and this tension guide 12 is placed on a tension arm (not shown) and is used to apply a predetermined tension to the magnetic tape 1. A tension detector of the tension applying means is configured. Further, 3 is a supply reel. On the other hand, on the right side (outlet side) of the cylinder 5, 13
Is an outlet-side first inclined guide (non-rotating guide) closest to the cylinder, 14 is an outlet-side roller guide (rotating guide), 15 is an outlet-side second inclined guide (non-rotating guide), and 16 is an outlet-side fixed guide (non-rotating guide). (Rotation guide), 17 is a capstan, 18 is a pinch roller, 19 is a delivery side height regulation guide (non-rotation guide), and 4 is a take-up reel. In addition, 20 has shown the mechanical chassis.

FIG. 1 shows a state in which the loading operation is completed. That is, when the tape cassette 2 is pushed into the cassette holder (not shown) and the holder is closed by hand, the tape cassette 2 slides from the position shown by the dotted line to the position shown by the solid line. And each guide 6, 7, 1
The magnetic tapes 1 wound around the supply reel 3 and the take-up reel 4 in the tape cassette 2 are pulled out by moving 2, 13, 14, 15, 18, 18 along the loading path indicated by the arrow in the figure. And the cylinder 5 has about 300 °
And the loading operation is completed.

The symbol Li (i = 1, 1) written on the traveling path from the cylinder 5 to the entrance-side height regulation guide 9 in FIG.
2, 3, 4) indicate tape spans. Here, the tape span Li is a tangential distance between the guides adjacent to each other when the tapes are mounted on the respective guides, and L1 is from the tape detaching point of the entrance-side first inclined guide 6 to the cylinder 5. To the tape entrance point, L2 is the distance from the tape exit point of the entrance roller guide 7 to the tape entrance point to the entrance first inclined guide 6, and L3 is the tape exit point of the impedance roller guide 8 to the entrance roller. The distance to the tape incident point on the guide 7, L4 is the entrance side height regulation guide 9
The distance from the tape detachment point to the tape incident point on the impedance roller guide 8 is shown.

Here, the diameter of the cylinder 5 is φ27 mm,
The diameter of the entrance-side first inclined guide 6 is φ2 mm, the diameter of the entrance-side roller guide 7 is φ4 mm, the diameter of the impedance roller guide 8 is φ7 mm, and the diameter of the entrance-side height regulation guide 9 is φ.
4 mm, and the guides are arranged close to each other. Table 1 shows specific numerical values of the tape span in FIG.

[0020]

[Table 1]

In this tape path configuration, when the recording / reproducing switch is pressed, the cylinder 5 and the capstan 17
Is rotated, and the magnetic tape 1 sandwiched between the pinch roller 18 and the capstan 17 travels in the direction of arrow a in FIG. Done.

FIG. 2 is an explanatory view showing the regulation state of the tape in the tape path of FIG. 1, which is shown by developing the portion from the supply reel 3 to the cylinder 5 of FIG. 1 in a straight line. Is.

In FIG. 2, the tape 1 running on the entry side
Is easily levitated from the lead 5a of the cylinder by the scanning force (indicated by F in the figure) of a magnetic head (not shown) mounted on the cylinder 5. Here, the linearity of the recorded video track is ensured. Therefore, the upper end position of the tape is regulated by the upper flange of the inlet side roller guide 7 which is positioned closest to the cylinder, and the lower end position of the tape is regulated by the lower flange of the inlet side height regulation guide 9, whereby the magnetic tape 1 is moved to the cylinder. The lead 5a is pressed and regulated.

By the way, in such a regulated state,
The tape 1 running on the entry side receives a bending deformation force (bending moment) as indicated by an arrow M in FIG. 2 between the cylinder 5 and the entry side height regulation guide 9. However, in this tape path, many guides are provided between the lead 5a of the cylinder and the entrance-side height regulation guide 9, and the tape span Li between the guides is 0.8 times or less of the tape width h (8 mm). As a result, since the tape is prevented from falling and deforming during running, the tape can be stably run without being greatly bent and deformed.

The features of the present invention will be described with reference to FIGS.
Details will be described with reference to Table 2 and FIG. FIG. 3 shows FIG.
In the tape path shown in FIG. 3, a tape path diagram in which the arrangement of the guides on the entrance side is partially changed, and FIG. 4 is similar to FIG.
Table 2 shows the guide interval values in the tape paths of FIGS.

The tape path shown in FIGS. 3 and 4 differs from the tape path shown in FIGS. 1 and 2 in that the guide distance K3 between the entrance side roller guide 7 and the entrance side height regulating guide 9 is a tape width of 8 m.
It is set to be wider than m. That is, as is clear from the comparison between Table 1 showing the guide spacing value and Table 2 below, the guide spacing value L3 in Table 1 is 4.5 mm.
And L4 = 6 mm are closer to each other than other guide intervals, but in the case of Table 2, K3 = 13.2 mm
As wide. Therefore, as shown in FIG. 4, the tape 1 is apt to have a falling deformed portion 1 ′ at a portion where the guide interval value K3 = 13.2 mm. The other configurations in FIGS. 3 and 4 are the same as those in FIG. 1, and the same portions are denoted by the same reference numerals and the description thereof will be omitted.

[0027]

[Table 2]

FIG. 5 is a diagram showing the relationship between tape longitudinal rigidity and track bending. This figure shows a tape path in which the tape spans of the guides 7, 8 and 9 shown in FIG.
FIG. 3 is a comparison of track bending ΔTw (track linearity) at the time of running thick and thin tapes having different longitudinal stiffness ELt ³ in two tape paths shown in FIG. 3 and a tape path having a wide tape span. .
In FIG. 5, the characteristic A is the characteristic when the tape span is narrowed as in the tape path of FIG. 1, and the characteristic B is the characteristic of the conventional guide mechanism having a wide tape span like the tape path of FIG. Shows.

As shown by the characteristic B in FIG. 5, in the tape path having a wide tape span, the track linearity value of the thick tape of 11 μm is no problem, but the track linearity of the thin tape of 7 μm is 8 mm. In the characteristic A of the tape path in which the tape spans are close to each other, the tape has a tape thickness of 11 μm or a thick tape of 7 μm. However, the track linearity does not change,
It shows that the tape is less likely to fall sideways and buckle.

Therefore, as shown in FIG. 5, it is effective to dispose the tape spans close to each other to a predetermined distance in order to prevent the tape from deforming.

Although the 8 mm video with a tape width of 8 mm has been described above, the present invention is not limited to the 8 mm video, and other systems such as DA using a 4 mm width tape can be used.
It is also applicable to a VHS type VTR using a T or a 1/2 inch (about 12.7 mm) width tape.

[0032]

As described above, according to the tape guide mechanism of the magnetic recording / reproducing apparatus of the present invention, in the tape path, the guides arranged on the entrance side are arranged in close proximity to each other in a predetermined relationship, and the rigidity is lower than that of the thick one. Even if the thin tape is run, the tape will not fall over sideways and buckle deformation is less likely to occur.
It is possible to provide a highly reliable tape guide mechanism for a magnetic recording / reproducing apparatus, for example, even if a thin tape is run, the linearity of a video track that is equivalent to that when a thick tape is run can be ensured.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a tape path by a tape guide mechanism of a magnetic recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram schematically showing the tape regulation state in FIG. 1 in a developed state.

FIG. 3 is an explanatory diagram showing a tape path obtained by partially changing the tape path of FIG. 1 for comparison with the embodiment of FIG.

FIG. 4 is an explanatory diagram schematically showing the tape regulation state in FIG. 3 in a developed state.

FIG. 5 is an explanatory diagram showing a relational characteristic between longitudinal rigidity of the tape and track bending.

[Explanation of symbols]

 1 Magnetic tape 1'Tape falling deformation part 5 Cylinder 6 Entry side first inclined guide 7 Entry side roller guide 8 Impedance roller guide 9 Entry side height regulation guide 10 Entry side second inclined guide 11 Entry side fixed guide 12 Tension guide Tape span between L1, L2, L3 and L4 guides

Claims (1)

[Claims] 1. A cylinder (5) equipped with a magnetic head and rotating at a high speed, and a magnetic tape (1) pulled out from inside a cassette (2) and wound around the outer periphery of the cylinder (5) at a predetermined angle, and a predetermined tape running path. Group of tape guides (6, 7, 8, 9, 10, 11, 12, 13, 14,
15, 16, 19) in a tape guide mechanism of a magnetic recording / reproducing apparatus, the height having a flange for regulating the running height of the magnetic tape (1) in the tape guide group. The tape span between the guides (6, 7, 8, 9) including the cylinder (5) forming the cylinder entrance side tape path portion from the regulation guide (9) to the cylinder (5) is Li,
A tape guide mechanism for a magnetic recording / reproducing apparatus, which has a tape path configuration that satisfies a relationship of Li ≦ 0.8h when a width dimension of the magnetic tape (1) is represented by h.