JPH087592Y2 - Tape cartridge - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a tape cartridge provided with a prism for optical path reversal for optically detecting a tape end.

[Conventional technology]

Conventionally, as shown in FIG. 4, a mode in which a continuous plate 32 is projected from the left and right ends of a transparent window plate 31 provided in an upper case 30, and a prism 33 is integrally molded at these projected ends (Japanese Patent Laid-Open No. 63- 317995
5) and a form in which the prism 33 is molded as an independent component as shown in FIG. 5 and is fixed to the upper case 30 by, for example, welding (reference is unknown).

[Problems to be solved by the device]

In the former case in which the prism 33 and the transparent window plate 31 are integrally molded, the gate position is often set in the vicinity of the center of the transparent window plate 31. Therefore, a short shot is likely to occur at the position where the prism 33 is formed, and there is a disadvantage that bubbles are generated in the meat wall and the optical performance is significantly impaired. Especially,
The transparent window plate 31 and the prism 33 are formed by the two-color molding method on the upper case 30.
In the case of integrally molding with the above, when the prism 33 has a molding defect, not only the transparent window plate 31 but also the upper case 30 must be discarded, and there is a problem in improving productivity.

In the latter case in which the prism 33 is molded as an independent component, it is possible to eliminate the above-mentioned molding defects and waste of productivity such as discarding defective components. However, the prism 33, which is a single component,
Since it is only a few mm in size, it is difficult to handle and
It is necessary to assemble the left and right separately, which inevitably has the disadvantage of increasing the number of assembly steps and the number of parts.

An object of the present invention is to obtain a tape cartridge in which the problem of molding failure and the problem of handling parts during assembly are solved at the same time by integrating the left and right prisms in a form that does not hinder molding.

[Means for solving the problem]

The tape cartridge of the present invention has a pocket 6 for tape loading on the front surface of the main body case 1, and the left and right circumferential walls 6a and 6a of the pocket 6 and the tape running path along the circumferential walls 6a and 6a are left and right. A pair of plastic-molded prisms 12 and 12 are provided, and the left and right prisms 12 and 12 are connected via inner arms 6b of the pocket 6 and connecting arms 15 provided along the inner surface of the upper wall of the upper case 1a. It is a requirement that they are integrally molded.

More specifically, connecting arms 15 that are narrow in the front and rear and are laterally long and horizontally,
A prism block 24 made of plastic, which consists of prisms 12 and 12 integrally formed on the left and right ends of the connecting arm 15, and whose gate position is set near the left and right center of the connecting arm 15, forms the upper wall of the upper case 1a. The prism block 24 is characterized in that the connecting arm 15 is attached to the inner surface of the inner wall 6b of the pocket 6 along the rear side of the case.

[Action]

The left and right prisms 12 and 12 are integrally formed via the connecting arm 15 in order to collect the left and right prisms 12 and 12 as a single component and increase the outer size thereof to facilitate handling. At this time, since the prism block 24 has a gate position set in the vicinity of the center in the left and right of the connecting arm 15, the distance from the gate position to the left and right prisms 12 and 12 can be shortened as much as possible. When the prism block 24 is mounted on the inner surface of the upper wall of the upper case 1a, the connecting arm 15 is attached to the rear side of the inner wall 6b of the pocket 6 as a reference.

[Effect of device]

According to the present invention, since the prism block 24 is formed by integrally molding the prisms 12 and 12 at the left and right ends of the horizontally and horizontally long connecting arm 15 having a small front and rear width,
-Unlike the form in which 12 is separated, it can be handled easily during assembly. Since the gate position is set near the left and right center of the connecting arm 15, the distance from the gate position to each of the left and right prisms 12 and 12 is shortened, and each prism 12 and 12 can be molded with high precision without causing a short shot.
When the prism block 24 is mounted on the inner surface of the upper wall of the upper case 1a, the connecting arm 15 is attached to the rear side of the inner back wall 6b of the pocket 6 so that the right and left prisms are attached.
12 ・ 12 can be accurately positioned and assembled easily.

[First Embodiment] FIGS. 1 to 3 show a first embodiment in which the present invention is applied to a tape cartridge for DAT.

In FIG. 2, the main body case 1 is made of a plastic upper case 1a and a lower case 1b butted and screwed together, and hubs 3 and 3 around which the tape 2 is wound are arranged on the left and right sides inside. These hubs 3 and 3 rotate on the left and right drive shaft insertion holes opened in the bottom wall of the main body case 1, and when loaded on the deck, the drive shafts on the deck side pass through the insertion holes to the respective hubs 3.
Engage with. A tape loading pocket 6 is provided in the front center portion of the main body case 1, and the tape 2 is led out to the front surface of the case through a pair of tape guides 7 provided on the left and right front ends of the pocket 6. It is connected to both hubs 3.3. When loaded on the deck, the tape 2 is pulled out forward through the pocket 6 by the loading pin on the deck side.

The front and lower surfaces of the pocket 6 are open, and the front surface side is opened and closed by the front lid 9 for tape protection and the lower surface side is opened and closed by the slider 10.

A transparent leader tape is connected to the winding start end of each tape 3 around the hubs 3 and 3. This leader tape is fed from the hubs 3 and 3, that is, the tape 2 in use.
In order to detect that the tape has reached the tape end, prisms 12 and 12 are arranged between the left and right peripheral walls 6a and 6a of the pocket 6 and the tape running path along these peripheral walls 6a and 6a.

In FIG. 3, the prisms 12 and 12 guide the horizontal light introducing portion 13 along the inner surface of the upper wall of the upper case 1a and the detection light S guided by the light introducing portion 13 in the reverse direction toward the running path of the tape 2. The trapezoidal prism main body 14 is provided, and the light introducing portion 13 is arranged in a state of traversing above the tape running path.

The left and right prisms 12 and 12 are integrated via a connecting arm 15 to form a prism block 24. As shown in FIG. 1, the connecting arm 15 is provided along the inner wall 6b on the upper case 1a side of the pocket 6 and along the inner surface of the upper wall of the upper case 1a. A short detour wall 16 is projected, and the projecting end of the detour wall 16 is the light introduction part of the prism 12.
Connect to 13. The connecting arm 15 is formed with a notch 18 and a mounting hole 19 for avoiding operational interference with the hub lock member 17. Attach the mounting hole 19 to the pin 20 protruding from the upper case 1a,
By melting and deforming the tip of the pin 20, the connecting arm 15 and the prisms 12 and 12 are integrated with the upper case 1a. The gate position of the prism block 24 is provided near the left and right center of the connecting arm 15.

In the figure, reference numeral 22 is a transparent window plate, 23 is a passage for the detection light S, and 25
Is a light source for emitting detection light, and 26 is an optical sensor for receiving light.

When the left and right prisms 12 and 12 are integrated via the connecting arm 15 as described above, the distance from the gate position to the prisms 12 and 12 can be shortened, and the flow path of the molten plastic can be simplified. Therefore, when the prism block 24 is molded, molding defects such as short shots do not occur at the prism formation position. Since the right and left length of the prism block 24 is as large as around 60 mm, its handling becomes easy.

The left and right peripheral walls 6a of the pocket 6 may be omitted, but in this case, the left and right inner side surfaces of the pocket 6 on the lower case 1b side can be regarded as equivalent members.

[Brief description of drawings]

1 to 3 show a first embodiment of a tape cartridge according to the present invention. FIG. 1 is a bottom view of the inside mainly showing the internal structure of the upper case side, and FIG. 2 is mainly the lower case side. FIG. 3 is a plan view of the inside showing the internal structure of FIG. 3, and FIG. 3 is a sectional view taken along the line AA in FIG. 4 and 5 respectively show a conventional tape cartridge, and FIG. 4 is a schematic bottom view of the upper case, and FIG.
The figure is a perspective view showing a prism mounting structure. 1 ... Main body case, 6 ... Tape loading pocket, 6a ... Left and right peripheral walls, 6b ... Inner back wall, 12 ... Prism, 15 ... Connecting arm.

Claims (1)

[Scope of utility model registration request] 1. A pocket (6) for tape loading is provided on the front surface of a main body case (1) formed by butting and coupling upper and lower cases (1a, 1b), and left and right peripheral walls (6a, 6a) of the pocket (6). And a pair of left and right pairs of plastic molded prisms (12, 12) are provided between the tape running path along these peripheral walls (6a, 6a). , A prism block (24) made of plastic, which is composed of prisms (12, 12) integrally formed on the left and right ends of the connecting arm (15), and the gate position is set near the left and right center of the connecting arm (15). The inner surface of the upper case (1a) has a prism block (2
4) The connecting arm (15) of this is the inner back wall (6) of the pocket (6).
A tape cartridge characterized in that it is attached along the rear side of the case of b).