JPH0461680A - Tape cartridge - Google Patents

Abstract

PURPOSE:To surely execute the detecting operation by installing a prism in the lower case, and aligning correctly the prism to light emitting/light receiving elements on a recorder side. CONSTITUTION:In front of the outer bottom face of the lower case 1b, a positioning reference hole 9 into which a positioning pin of a recorder side is inserted at the time of loading to a recorder is provided, and on the inside surface of the lower case 1b, a tape end detection prism 11 is installed. In the prism 11, the vertical surface of the outer end side of the upper part, the 45 degree inclined surface of the inner end side, the 45 degree inclined surface opposed to a first reflecting surface 13, and the vertical surface of the outer end side are formed on the incident side transmission surface 12, a first reflecting surface 12, a second reflecting surface 14, and the emitting side transmission surface 15, respectively. Accordingly, even if there is a shift in butting of the upper case 1a and the lower case 1b, the prism 1 is always opposed exactly to a light emitting element 20 and a light receiving element 21 of the recorder side, and can receive and send surely light. In such a way, the prism can be aligned correctly to the light emitting and the light receiving elements of the recorder side, and the detect ing operation can be executed surely.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a tape cartridge incorporating a prism used for optically detecting the beginning and end of a magnetic tape.

[Conventional technology]

An example of a tape cartridge incorporating this type of prism is an AT tape cartridge as disclosed in Japanese Patent Application Laid-Open No. 63-317995.

FIG. 4 shows the tape end detection structure of this device, in which the path of light for detecting the tape end emitted from the light emitting element 20 on the recorder side is inside the main case 1 formed by abutting the upper and lower cases 1a and 1b. A prism 31 is installed in the upper case 1a to change the light and send it back to the light receiving element 21 on the recorder side.

[Problem to be solved by the invention]

However, with the aforementioned DAT tape cartridge,
Reference holes for positioning when loading the recorder (in Figure 2,
9) is provided at the rear of the outer bottom surface of the lower case 1b. Therefore, if there is a positional deviation in the butt-matching state of the upper and lower cases 1a and 1b, this will directly lead to a deviation in the positional relationship between the prism 31 on the front side of the upper case and the positioning reference hole 9 on the front side of the lower case. Even when this tape cartridge is loaded into a recorder, the prism 31 does not accurately face the light emitting element 20 and the light receiving element 21 on the recorder side, causing trouble in detecting the end of the tape.

The present invention provides a tape cartridge equipped with a prism for changing the course of light for tape end detection emitted from the recorder side and sending it back to the recorder side, as described above, by devising an arrangement of the prisms. By doing so, it is possible to correctly align the prism with the light emitting/receiving element on the recorder side without being affected by the misalignment of the upper and lower cases, thereby increasing the reliability of the detection operation.

[Means for Solving the Problems] The present invention focuses on the fact that the reference hole 9 for positioning when loading a recorder is provided in the lower case 1b instead of the upper case 1a, and the prism 11 is adjusted accordingly. It is installed in the lower case 1b.

[Operation] In such a case, even if there is a misalignment between the upper and lower cases 1a and 1b, when loaded into the recorder, the prism 11 will not be misaligned with the light-emitting/light-receiving elements 20 and 21 on the recorder side (they cannot be correctly opposed to each other). can.

〔Effect of the invention〕

According to the tape cartridge of the present invention, regardless of the misalignment between the upper case 1a and the lower case 1b, the prism 11 can be accurately aligned between the light emitting/light receiving element 20 and the light receiving element 20 on the recorder side.
21, the light can be introduced into the prism 11 and sent back to the recorder side without loss, and the detection operation can be performed reliably.

〔Example〕

An embodiment of a tape cartridge for DAT according to the present invention will be described with reference to FIGS. 1 to 3.

In FIG. 3, the main body case 1 is formed by abutting upper and lower plastic cases 1a and 1b and integrally connecting them with screws or the like. A hub 4 is rotatably disposed above the left and right drive shaft insertion holes 3 inside the main body case 1, and a magnetic tape 5 is connected to and wound around the hub 4 via a permeable leader tape.

Tape outlet ports 6 are formed on the left and right sides of the front side of the main body case 1, and the magnetic tape 5 is led out from one hub 4 forwardly through the tape outlet port 6 to the front side of the case. It is then wound onto the hub 4 at the rear of this. A front M7 is pivotally attached to the front side of the main body case 1 so as to be openable and closable, and when not in use, the front lid 7 closes the tape outlet 6 and protects the lead-out portion of the magnetic tape 5. There is. A slider 8 for opening and closing the drive shaft insertion hole 3 is attached to the outer bottom surface of the lower case 1b so as to be slidable in the front and rear directions.

In FIG. 2, a positioning reference hole 9 is provided in the front part of the outer bottom surface of the lower case 1b, into which a positioning pin on the recorder side is inserted when the recorder is loaded. On the inner surface of the lower case 1b, prisms 11 for detecting tape ends are installed on the left and right sides of the front.

In FIG. 1, the prism 11 has a perpendicular surface on the outer end side of the upper part formed as the incident side transmission surface 12, and a 45 degree slope on the inner end side as the first reflection surface 13. A 45-degree slope on the inner side facing the second reflective surface 14 and a perpendicular surface on the outer end side are formed as the output side transmission surface 15, respectively, and the lower base end 11a of this is formed on the inner surface of the lower case 1b. They are joined and fixed using sonic welding. This prism 1 can also be molded integrally with the lower case 1b by a two-color injection molding method.

The left and right side walls 16 of the upper case 1a are provided with an inlet hole 17 and an outlet hole 18 for the detection light.
2 and the exit side transmission surface 15, respectively, the introduction hole 17
- 18 is positioned so as to face the light emitting element 20 and light receiving element 21 on the recorder side when this tape cartridge is loaded into the recorder.

Thus, when this tape cartridge is loaded into a recorder, the light emitted from the light emitting element 20 passes through the introduction hole 17 on the tape cartridge side and reaches the incident side transmission surface 1 of the prism 11.
2. This incident light is transmitted to the first reflecting surface 13 and the second reflecting surface 13.
The direction of the light beam can be changed by 90 degrees with the reflective surface 14,
The light beam exits parallel to the incident light beam from the output-side transmission surface 15, passes through the magnetic tape 5, exits from the lead-out hole 18 to the outside of the case, and reaches the light-receiving element 21 on the recorder side. It detects whether it is tape 5 or the leader tape connected to this end.

Even if there is a misalignment between the loaded tape cartridge upper case 1a and lower case 1b, since the prism 11 is installed on the lower case lb side that has the positioning reference hole 9, the tape cartridge The prism 11 on the side always accurately aligns with the light emitting element 20 on the recorder side.
It faces the light-receiving element 21 and reliably receives and transmits light without loss, so that the detection operation is performed reliably.

Further, the light introduction hole 17 is not provided in the upper case 1a due to the restriction of the positional relationship with the magnetic tape 5 and the light emitting element 20 on the recorder side.
It is set along the inner surface of the

However, in such a case, the conventional prism 3 shown in FIG.
If this is bonded and fixed to the inner surface of the upper case 1a using ultrasonic welding or adhesive as in 1, the bonded portion will easily obstruct the incident optical path, and the welding heat will cause the upper case 1
Although deformation and color unevenness occur on the outer surface of the lower case 1b, which impairs the appearance, it is advantageous that such problems do not occur even if the prism 11 is bonded and fixed to the inner surface of the lower case 1b by ultrasonic welding or adhesive. It is.

[Brief explanation of drawings]

1 to 3 show an embodiment of the tape cartridge according to the present invention, FIG. 1 is a longitudinal sectional front view of the main parts, FIG. 2 is an internal plan view of the whole, and FIG. 3 is a diagram of the whole. It is an external perspective view. FIG. 4 is a longitudinal sectional front view of the main parts of a conventional tape cartridge. 1...Body case, 1a...Upper case, 1b...Lower case, 5...Magnetic tape, 9...Reference hole for positioning, 11... Prism, 20... Light emitting element, 21... Light receiving element. Figure 3 Inventor Nobutaka Miyazaki

Claims (1)

[Claims] 1. The main case (1) is formed by abutting an upper case (1a) and a lower case (1b) having a reference hole (9) for positioning the tape cartridge; Inside the recorder side light emitting element (2
0) to change the path of the light for detecting the tape end,
A tape cartridge equipped with a prism (11) for sending light back to a light receiving element (21) on a recorder side, wherein the prism (11) is installed in a lower case (1b).