JP3162140B2 - Tape cassettes, especially magnetic tape cassettes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a housing having a bottom surface and a top surface (4, 5) and a lateral center line (q), a turning element (14), a bottom surface (4) and a top surface (5). The present invention relates to a tape cassette comprising a tape guided in a casing by guide elements (16, 17) each formed by molding, and more particularly to a magnetic tape cassette.

2. Description of the Related Art Three protrusions for receiving a magnetic head are provided in a raised portion of a housing of a compact cassette.
Similarly, guide elements for magnetic tape are provided on the raised portion of the housing, and the quality of recording / reproducing of the cassette is significantly different depending on these guide elements. Conventionally, the lower and upper halves of the housing are formed by using relatively inexpensive plastic, especially under heating, but as a result, the position of the guide element changes, and as a result, the quality of the housing is changed. Gets worse.

[0003]

2. Description of the Related Art Tape guide elements are provided on the right and left sides with respect to a horizontal center line of a top surface of a housing, or a pair of inner guide pins are provided on a bottom portion symmetrically with respect to the horizontal center line. Compact cassettes in which adjacent pairs of outer guide pins are molded on top of each other are known. However, this either results in an asymmetric arrangement of the guide elements or only corrects for symmetry errors of the guide elements near the transverse centerline.

[0004] US Pat. No. 3,661,345 discloses a compact design in which deflecting pins having a slightly conical cross section are engaged together from the bottom and top surfaces and are mounted together, for example in the form of an outer cylinder. It discloses forming a fixed deflecting pin in a cassette. However, this can lead to significant degradation under frictional conditions, and the simultaneous mounting of the conical members can lead to even greater distortions than the existing distortions are corrected for the position of the guide element.

An object of the present invention is to improve a tape cassette from the viewpoint of the accuracy of tape guiding.

[0006]

SUMMARY OF THE INVENTION An object, however, is to provide a housing having a bottom and top surface (4,5) and a lateral centerline (q), a diverting element (14), a bottom surface (4) and a top surface. Guide elements (16, 1) formed by molding on (5), respectively.
7) a tape cassette, in particular a magnetic tape cassette, consisting of a tape guided in the housing by a guide element pair (24, 15 and 15, 16, 16 and 16) with respect to said transverse center line (q). 17) are provided symmetrically and one guiding element (15 and 1) of each pair is provided.
7) on the bottom part (4), the other guiding element (2) of the same pair.
It has been found by the present inventors that this can be achieved by a tape cassette characterized in that 4 and 16) are each molded on the top surface (5).

This makes it possible, for example, to compensate for thermally induced tilting of the guide element and thus to prevent its angular error caused by the cassette.

In yet another embodiment, ie, in a cassette in which the diverting element and the guiding element are symmetrically arranged, a pair of adjacent guiding elements are arranged between each diverting element and the lateral center line. Is preferred.

This results in an evenly compensated tape guiding effect on each side of the cassette on either side of the lateral center line, especially on both sides (after rewinding) as in the case of compact cassettes. It is particularly advantageous in cassettes operated at.

In a preferred embodiment, at least one pair of adjacent guide elements is arranged in the vicinity of the diverting element.

As a result, it is possible to advantageously correct an error in the position of the guide pin in and around the deflecting roller shaft.

Further, at least one pair of adjacent guide elements includes:
It is particularly preferred to have guide elements arranged in close proximity to one another, each having a tape-adhesive surface.

The partial guide element thus arranged is a single guide element which provides an automatic correction if the two partial guide elements are inclined in opposite directions and the tape makes a central contact with both contact surfaces. Has the effect of

Preferably, the longitudinal axes of the pair of adjacent guide elements are substantially parallel to each other. A further characteristic feature of the guiding element according to the invention is that it takes the form of an elongated web or a cylindrical guide pin or a combination of both.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS Illustrative embodiments of the present invention are described below with reference to the accompanying drawings.

A known standard compact cassette K is:
Two hubs 1, rotatably mounted in a common plane,
2 and the tape 3 is wound on them and unraveled from them. This cassette has a bottom part and a top part 4,
5, each of which has a front wall, a back wall and side walls 6, 7
And 8. The housing halves have housing ridges 10a, 10b, respectively, which start at the front wall 6 and extend toward the rear wall to accommodate at least one recording / reproducing magnetic head 11. (Figure 2
reference). The front wall 6 has two openings for accommodating other elements such as an erasing head 12 and a rubber pinch roller 13 for driving a tape by a capstan 19. In order for each of these elements to be able to provide the necessary and precisely defined contact with the magnetic tape 3, the tape 3 is moved from the tape roll of the hub 1 to the hub 2 along the front wall 6.
Deflecting roller 14, guiding element 15,
If the cassette 16 is to be operated in the opposite direction, it is guided in the reverse order as described above. Any deviation of these guide elements from their vertical position by more than 25 μm will result in a decisive azimuthal error, which will have a detrimental effect on the high-frequency audio signal. Make the cassette box a little stronger
To provide longitudinal stability in this area, ribs or webs 25 extend from the side walls, preferably around the deflection roller 14. Due to the thin walled steps 18a, 18b provided in the housing ridges, the housing becomes uneven, but this cannot be corrected by common design means. Bottom part, surface part 4, which covers the tape roll,
5 is generally about 1.8 mm, but the wall thickness of the housing ridges 10a, 10b is at least about 1.0 mm at least in the opening area of the front wall 6 (hereinafter simply referred to as the front opening). Until thin. In the case of injection molding, the above asymmetry causes distortion of the material, which, for example, in the case of exposure to heat, balances with each other due to the bending of the elevations 10a, 10b in the directions A and A '(FIG. 1).

FIG. 2 shows an embodiment of the present invention, wherein the housing K is configured symmetrically with respect to the horizontal center line q.

The tape 3 passes from the hub 1 through guide pins 22, a deflecting roller 14 of a spindle 23, and guide elements 15, 24 formed as flat webs, and then between a pinch roller 13 and a capstan 19, and further. The guide web 16 and the guide pin 17 lead to a transverse centerline q, which in turn runs the guide and deflection elements in the other half of the cassette in reverse order to the hub 2.

For the purposes of the present invention, adjacent tape guide elements are arranged in guide webs 15, 24 which are arranged in very close proximity.
And the guide web 16 and the guide pin 17 which are arranged at a relatively large interval. That is, on each side, there are two pairs of proximity guide elements (15, 24 and 16, 17) between each diverting roller 14 and the lateral centerline q. As will be described later, the number of the element pairs can be increased.

Guide elements 15 and 17 provided on bottom surface 4
Is shown as a plan view, but the guide elements 24, 16 provided on the top surface 5 are shown with diagonal lines to distinguish them.

The guide webs 15, 24 are arranged very close to each other as a trouble-free assembly, their cross section is configured as a somewhat elongated rectangle, and their feed contact surfaces are slightly rounded. . The thickness of the webs 15, 16, 24 is determined by the possible manufacturing and assembly tolerances.

Although the second pair of guide elements 16, 17 are arranged at a slight distance from each other, this mounting manner mounted on the top surface 5 and the bottom surface 4 is similar to the first pair 15, 24. The same correction effect as in the case is shown.

The manner in which the adjacent guide elements are mounted, one on the bottom part and the other on the top part, for example in the direction A of the thermally induced housing ridge 10A and in the direction A 'of the ridge 10B The deflection causes the guide elements to be deflected to the same extent in opposite directions with respect to the tape 3 (provided that the bottom and the top are made of the same material). The deflection in the directions of the arrows A and A 'has the following effects on the running tape.

That is, at the transverse centerline q, the tape 3 is likewise deflected in the direction A at each of the first guide elements 17, which are integrally formed and mounted on the bottom wall 4, more precisely on the ridge 10a. I'm sullen. However, the second guide elements 16, 24 then mounted and mounted on the ridge 10b
, A deflection in the opposite direction (A 'direction) is immediately effected. As a result, the tape 3 is connected to each adjacent guide element pair (1
7, 16) and (15, 24) take an intermediate position,
This intermediate position is maintained by using a plurality of pairs of guide elements arranged symmetrically along the housing front 6.

Of course, the guiding elements 16, 17, 22
Automatically correcting each guide element pair by using the above guide elements such as 15 and 24 by doubling by 16A, 17A and 22A which are formed and mounted on the bottom and top surfaces of the housing respectively. It is also possible to make sure.
This modified embodiment is shown schematically in FIG.

With such a configuration of the tape cassette according to the present invention, it is possible to provide the following numerically significant improvements over the conventional compact cassette. Testing of a compact cassette marketed by the applicant company against a compact cassette (CC) according to the invention gave the following results. Both compact cassettes are heat aged (HA) at 85 ° C. for 8 hours,
The azimuth angle of the magnetic head gap of the tape of each cassette was measured before and after that. The values are shown in the table below.

Table CC type HA front azimuth angle (min) HA rear azimuth angle Commercially available CC <3.5 '<5' Invention CC <1.9 '<2.8' One angle is one degree 60 minutes It is 1.

Thus, in the present invention, the improvement in azimuth can be made by a factor of two or less, ie the azimuth error in the cassette can be made at least by a factor of two or less.

Commercially available compact cassettes that have provided such azimuthal improvements and the achievement of tape guidance accuracy at relatively low expense are not known.

For the purposes of the present invention, magnetic tape cassettes are applicable to all audio, video, data and measurement tape cassettes.

[Brief description of the drawings]

FIG. 1 is a sectional view of a conventionally known compact cassette,

FIG. 2 is a schematic plan view of a compact cassette having a tape guide and deflection element according to the present invention;

FIG. 3 is an enlarged partial plan view showing the compact cassette of the present invention having different tape guiding elements.

[Explanation of symbols]

 K: Compact cassette q: Box lateral center line 1 ... Hub 2 ... Hub 3 ... Magnetic tape 4 ... Bottom part, top part 5 ... Bottom part, top part 6 front wall, back wall, side wall 7 front wall, back wall, side wall 8 front wall, back wall, side wall 10a box ridge 10b box Raised portion 11 Magnetic head 12 Erase head 13 Pinch roller 14 Deflection roller 15 Guide element (guide web) 16 Guide element (guide web) 17・ Guide element (guide web) 18a ・ ・ ・ Protrusion step 18b ・ ・ ・ Protrusion step 19 ・ ・ ・ Capstan 22 ・ ・ ・ Guide pin 23 ・ ・ ・ Spindle 24 ・ ・ ・ Guide element (Guide web)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References Japanese Utility Model Sho 55-44453 (JP, U) (58) Fields surveyed (Int. Cl. ⁷ , DB name) G11B 23/087

Claims (7)

(57) [Claims] 1. A housing having a bottom surface and a top surface (4, 5) and a lateral center line (q), and a turning element (1).
4), a bottom portion (4) and top wall (5) in a tape cassette consisting of the guide elements which are respectively塑造molding (16, 17) as a tape that is guided in Napishtim body, upper <br/> Kiyoko direction With respect to the center line (q), the adjacent guide element pair (24,
15 and 15, 16 and 16, 17) are provided in contrast, one guide element (15 and 17) of each pair being on the bottom (4), the other guide element (24 and 16) of the same pair. Are molded on the top surface (5) respectively .
Adjacent guide element pairs (24, 15 and 15, 16 and
16 and 17) are each turning element (14) and the horizontal center line.
(Q) . 2. The tape cassette according to claim 1, wherein at least one pair of adjacent guide elements (15, 24 and 22, 22A ) is arranged in the vicinity of the deflecting element (14). Tape cassette. 3. The tape cassette according to claim 1, wherein the adjacent guide elements (15, 24 and 22, 22) are arranged in parallel.
A tape cassette, characterized in that at least one pair of A ) is arranged close to each other , each having a contact surface for a tape (3). 4. A tape cassette according to any of claims 1 to 3, neighbor guide element (15, 24 and 2
2, 22A) A tape cassette wherein the longitudinal axes of each pair are substantially parallel to each other. 5. A tape cassette according to any one of claims 1 to 4, the guide element (15, 24 and 16
A, 16) wherein the web (A, 16) is formed to form an elongated web in cross section, and the contact surface for the tape (3) is provided on the narrow side of the web. 6. A tape cut set according to any of claims 1 4, the guide element (22, 22A, and 1
7, 17A) is formed as a cylindrical guide pin. 7. A tape cassette according to claim 5 or 6, the guide element is a web (15, 24 and 16
A, 16) and pins (22, 22A and 17, 17A)
Characterized by having both of the above.