JPS59221857A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To attain stable running by combining properly a drum, conical posts, and parallel rollers to satisfy conditions of height, paralleism, and stress. CONSTITUTION:Heights of the tape center line from a reference face at a tape entrance point 121 to a conical post 12 and in the part from a tape exit point 131 of a conical post 13 to a cassette entrance are equalized. The tape center line in the part from a cassette exit to the tape entrance point 121 and the part from the tape exit point 131 to the tape entrance is made parallel with the reference face. Twisting of the tape between respective guide bodies is prevented. These three conditions are satisfied to run the tape stably in the entrance and the exit of a cassette.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to an oblique scanning type magnetic recording/reproducing device, and in particular, the present invention relates to a diagonal scanning type magnetic recording/reproducing device, and in particular, a magnetic recording/reproducing device that pulls out a tape from a parallel two-axis type cassette and moves it along a path parallel to a reference plane parallel to the cassette. The drum and conical guide (hereinafter referred to as the conical post) are parallel to each other in order to wind the tape in a helical line at a predetermined angle onto a cylindrical tape guide (hereinafter referred to as the drum) with a built-in two-rotation head. The present invention relates to a diagonal scanning magnetic recording/reproducing device that can be appropriately combined with rollers to obtain a compact, low power consumption, and stable tape running system.

(Prior art and its problems) The tape is guided from the cassette in a path parallel to the jintei surface,
When trying to obtain stable running, the drum 1 and the conical bosses 12 and 13 located at the rear of both sides of the drum are installed at an angle with respect to the reference plane as shown in Figure 1.
The tape is wound around the bosses 12 and 13 using a set of parallel rollers 1 perpendicular to a reference plane provided to adjust the angle.
4 and 15 may be combined. In FIG. 1, the tape is represented by a tape center line 16.

This method uses only one set of parallel rollers to pull out the tape from the cassette, and winds the tape around the drum via a conical post placed close to the drum, making the tape running system compact. can do. However, the stable running conditions have not been fully theoretically elucidated, and the only option was to rely on trial εR errors, making it difficult to obtain a stable tape running system.

Next, consider the stable running conditions for the tape in this method.

Parallel rollers 14°15 installed perpendicular to the reference plane
Is it possible to change the traveling direction of the tape running parallel to the reference plane? Since the height from the reference plane and the degree of parallelism to the reference plane cannot be changed, it is possible to stabilize the tape at the entrance and exit of the cassette. In order to run the vehicle, the following three conditions must be satisfied.

(a) Height conditions: 10 tape points 121 and 1 conical post to the inner post 12]: The tape center line reference [height from the top or equal to the tape exit point 131 at 3].

(b) Parallel condition: The tape center line from the cassette exit to the point 121 and from the front point 13 to the cassette center line should be parallel to the reference plane.

When using a conical post, the tape runs in a twisted manner between the drum and the conical post, between the four conical posts and the parallel rollers. Therefore, between the drum and the post, between the post rollers (c, between the tape center line and the longitudinal direction of the tape
□1. and the travel h' ((because the distances are different, the stress distribution in the longitudinal direction of the tape will be different, and it is convenient to avoid causing one-sided elongation of the tape. However, the amount of twist of the tape The stress value is minute and the allowable value is 11'
If it is within 1, there is no problem in running the tape.

The present invention uses the above (a) when using a 9-conical post.

(b) The objective is to obtain a tape running system that satisfies condition 2' and also satisfies condition (C) below.

(c) Stress chromaticity The tape must not twist between each guide. Also.

Even if the tape is twisted, there is no problem in running the tape as long as the stress generated in the tape due to the twisting is within the allowable value.

(Purpose) The present invention provides a stable running condition by appropriately combining a drum, a conical post, and a parallel roller to satisfy the three conditions mentioned above. The purpose is to rationally realize the following.

(Example) A method for deriving a relational expression that satisfies the above-mentioned stable running conditions will be described with reference to FIG.

FIG. 2 shows the state when the drum 11 is installed perpendicularly to the reference plane. In the figure, the X-χ and y-y' axes are a coordinate system having its origin at the center of the drum, and the two axes are perpendicular to the reference plane. "p"p'+ yp 3'p'
are auxiliary coordinates provided at the center of the post 13. The tape center 1G is wound around the drum 11 with a predetermined lead angle! Kera j'1. , is wound around the boss 13 by θ. Incidentally, the lead angle is set in a direction 41 from the center line of the tape to the reference plane and descending. (”+37
Those shown in the form of "+") represent spatial coordinates and indicate the coordinates of the initial point of contact or separation point between the tape center line and the drum 11 and the conical post 13. All angles are expressed in radians.In the figure, the coordinates of (,X+ +Yl +Zi) are.

(X+, Y+ +Zl) = [γOcosβ, γ0s
inβ, γO(2+β) tan S': ]. In reality, the drum 11 is used tilted by α in the / direction. The coordinates at this time are (z,,y,.

z]] 1, this rotates the coordinate axis around y-y' by an angle of α,
, y, , Z+') is reflected in the law.

That is, it can be determined by three-dimensional coordinate transformation.

The coordinates of each point when Drum 1 is tilted at a predetermined angle in a predetermined direction are expressed by subscripts attached to the lowercase letters X:, y, and Z as shown in the quadratic form.

Cx+ +y+ +zl :)-CγoCO5β, γo
sinβ, γo((+β)tarls)(α]Jr(,
7:2-2,) 2 moves - 0 well y1) 2・master δ + 24) z4
== z3+13' tanχ z522. +mu' tanχ tanχ= tanχ' cosξ However, [ ] represents a matrix, and the newly used symbol is the third
Referring to Figure 4, it is as follows.

γ0; Drum guide radius S; Lead angle α; Drum guide inclination angle β; Over-ramp angle β' for wrapping the tape around the drum guide; Precautions when the tape separates from the drum guide The angle between the x- and x' axes in a plane parallel to the plane.

+X:p,,6. yp, o; obtuse: Bost center coordinate δ
; When the tape separates from the drum guide, the inclination angle δ' of the tape with respect to the reference plane; the incident angle ξ of the tape on the conical surface of the conical post; the half-apex angle R of the conical post; l] [l-post] Length of the generatrix at the point of incidence of the second tape χ;
CO3α5inS) Two center coordinates y7 = cos-,'('-',",-two")θ-end-r-η-β'χ'=δ'-θsinξl--'-'-cosδ' 2 (13'= J L2- (γ''C05Z'+γ2)
β,'=γ2(r+η+(+θ+β')) The above are the relational expressions that satisfy conditions (a) and (b) of the above stable running conditions.Therefore, (a) height condition z520( b) The Heisei 11 condition tanχ=-O can be determined.

Next, a method for deriving the relational expression regarding the condition (c), that is, the stress condition, will be explained.

When considering IJL and force conditions, it is necessary to find the coordinate values of the exit point and the incident point at the two ends of the tape, the drum at the bottom end, and the conical post. For the overlap winding example, based on the angle β, find the drum winding curve (spiral line) and the bost winding curve at each of the upper and lower ends of the tape, and find the common tangent to both curves ( (The above coordinate values can be obtained.) When both the curves are derived, the result is as follows.

Drum winding curve (at the exit side bottom (underlined)).

(In the case of the lower end of the tape) Here, φQ is the angle formed with the x-1 axis when the drum is not tilted.

Conical post winding curve (at the exit post (underlined) and at the upper end of the tape) where ψ is the angle formed with the auxiliary coordinate axes rp-, r,'.

Further, t is the half width of the tape.

Next, the concept of common tangents will be explained.

When the parameters of both curves derived above are expressed as φ (ψ is a function of φ, and the relationship is the same as the relationship between β and β'), they are as follows.

Drum spiral line x = f, (φ) y = f2 (φ) ・・・−・−(1) z=f3
(φ) Circle ↑) [Boss winding curve, ”-!7+ (φ) y = , q2(φ) ・・・Middle・・・・・・
(2) z-g3(φ) Furthermore, the equations of tangents at a certain corner φ0 north of each curve are expressed as follows using a real hole K.

ddodφOclφ.

The coordinate values of the above-mentioned departure point and incidence point can be found by finding values for (that match the straight lines expressed by equations (3) and (4)).

φ. It is best to solve the simultaneous equations of equations (3) and (4). The simultaneous equations are as follows.

This simultaneous equation (parameters; φo, J, K) is solved by a computer using the Newton-Rabnon method, and φ0
seek. Once φ0 is determined, the coordinates of the tape entrance and exit points of the drum and conical post can be obtained.

Once the coordinate values are determined, the lengths of the tape running paths at the tape L end, center, and bottom end are determined, and the stress distribution within the tape is calculated by comparing the lengths, and it is confirmed that the stress distribution within the tape is within the allowable value. I can do it.

The above explanation is based on the case where the upper end of the tape is considered at the exit conical post (underlined), the lower end of the tape at the exit post, and the upper end of the tape at the entry conical post (5 sets).
The lower end cases can also be determined using the same method.

In the tape running mechanism, which was created based on the numerical values obtained from Total 9, as I did, the manufacturing of each part was determined. 'i
In order to compensate for slight deviations in the tape running height caused by variations in the height of the tape, a spiral spring is provided at the bottom of each of the conical posts and parallel rollers to push them away. and -1 of the support axis: jYl(to t!l'
By providing the j, the height can be easily adjusted using a screwdriver or the like.

When installing the parallel rollers, fix them to the stand.

This installation is O-7' when loading the stand or tape.
The parallel rollers move together with the English section and pull out the tape from the tape cassette.

Then, the parallel roller that pulled out the tape moves along the loading mark L so that it has a component in the direction of the bisector of the drum winding angle, and after the loading is completed, a part of the loading movable part moves It is configured to come into pressure contact with a stopper installed in the main body of the device.

In this way, the position of the parallel rollers is fixed after loading is completed.

(Effects) In the above explanation, we have focused on examples using a parallel two-axis type cassette, but in other cases, it is necessary to obtain stable running conditions when using that cassette. Bye.

According to the present invention, the traveling mechanism including tape loading can be configured to be small and stable, and power consumption can be reduced by reducing friction.

[Brief explanation of drawings]

Figure 1 is a schematic plan view of the main parts to explain the diagonal scanning magnetic recording/reproducing device, Figure 2 is an explanatory diagram to derive stable tape running conditions, Figure 3 is a developed view of the conical post, and Figure 4. is a perspective view of a conical post. 11 drum, 12.13 conical post, 1
4.15 Parallel rollers, 16 Tape center line. Figure 1 (λ'31 h, s3 and f (χl ・'J'5・75) \ ) ・j/,,XI)

Claims (1)

[Claims] (1) A cylindrical tape guide with a built-in rotary head installed with its center of rotation inclined at a predetermined angle with respect to a reference plane, at a predetermined lead angle of approximately 180 degrees. In order to wind the magnetic tape in a helical line over an angle range of , a pair of conical guides are arranged on both sides of the bisector of the winding angle. , a set of parallel rollers perpendicular to a reference surface are provided on the conical guide body at a predetermined angle 10 for winding the RFIJ recording magnetic tape. The iH magnetic tape center line and the tape winding track of the tape guide pass through a point on the magnetic tape center line 1- corresponding to the center point of the corner, respectively, on the earth flow side and downstream side of the conical guide body. The tape twist caused by using one conical guide while ensuring that the plane is the same as the reference plane and the flat TJ.The upper and lower ends of the tape of the cylindrical tape guide and the conical guide A magnetic recording and reproducing apparatus characterized in that the stress conditions are analyzed by replacing the coordinates of the incident point and the exit point in the tape, and the stress generated in the tape is kept within an allowable value. The magnetic recording and reproducing apparatus described above, characterized in that the conical guide and the parallel roller are provided with means for adjusting the height of the tape from the reference surface. (3) In the magnetic recording and reproducing apparatus according to claim 1, the parallel roller is fixed to a pick-up table, and the pick-up table moves together with the loading movable part during tape loading, and the parallel roller A magnetic recording/reproducing device characterized in that a roller pulls out a tape from a tape storage body. (4) After the parallel roller pulls out the tape from the tape storage body, the drum winding is a component in the direction of the bisector of the corner. 1. A magnetic recording and reproducing apparatus, wherein the rotating movable part moves on a loading trajectory so as to hold the rotating part, and after loading is completed, a part of the rotating movable part comes into pressure contact with a stopper installed in a main body of the apparatus.