JPS6245355Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cassette tape for a magnetic recording/reproducing device.

In general, in a cassette type magnetic recording and reproducing device, as shown in Fig. 1, a light source body 2 is inserted into a cassette case 1, and the light from the light source body 2 that passes through the transparent tape portion at the beginning and end of a tape 3 is detected by a light detector 4, thereby detecting the beginning and end of the tape 3.
The take-up reel is designated by 6. The positions of the light source 2 and the light detector 4 may be reversed.

However, in the conventional cassette tape for magnetic recording/playback devices, as shown in FIG. Although the light A from 2 is blocked by the tape 3, depending on the characteristics of the light source 2 and the photodetector 4 or the tape winding diameter, the reflected light B from the inner surface of the reel flange may be transmitted to the photodetector. 4 was detected, causing a malfunction.

The present invention provides a cassette tape for a magnetic recording/reproducing apparatus which solves the above-mentioned problems, and one embodiment thereof will be described below with reference to the drawings.

In FIG. 3, reference numeral 8 indicates a light source body consisting of a light emitting diode, etc., which is inserted into the inside of the cassette case;
10 is a photodetector consisting of a phototransistor or the like that detects the light from the light source 8, and 10 is a tape. In the figure, the non-transparent part of the tape 10 is located between the light source 8 and the photodetector 9. There is. 11,1
Reference numeral 1 designates reel flanges that sandwich the tape 10, and the inner surface of each reel flange 11 is provided with a surface finish 11a such as a satin finish that diffusely reflects light over the entire surface. Therefore,
The light C irradiated from the light source 8 onto the inner surface of the reel flange 11 is diffusely reflected, and the amount of light incident on the photodetector 9 is extremely small, so that the light D irradiated directly from the light source 8 onto the tape 10 If the photodetector 9 is blocked by the photodetector 9, the photodetector 9 will not operate.

As explained above, according to the cassette tape for a magnetic recording/playback device according to the present invention, the entire inner surface of the reel flange and the entire inner surface of the lower reel flange are given a surface finish that diffusely reflects light. The amount of light reflected from the inner surface that is incident on the photodetector can be significantly reduced, so there is no risk that the magnetic recording/reproducing device will malfunction when detecting the beginning and end of the tape.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of the tape end detection method, Figure 2
The figure is an explanatory diagram of a conventional example, and FIG. 3 is an explanatory diagram of an embodiment of the present invention, showing the main parts of a cassette tape installed in a magnetic recording and reproducing apparatus. 11... Reel flange, 11a... Surface finish that diffusely reflects light.

Claims (1)

[Scope of utility model registration request] Light is irradiated onto the magnetic tape wound on this reel through the space between the upper reel flange and the lower reel flange, and the portion of the transparent tape provided at the beginning and end of the magnetic tape is detected by the transmitted light from the magnetic tape. 1. A cassette tape for a magnetic recording/playback device, characterized in that the entire inner surface of the upper reel flange and the entire inner surface of the lower reel flange are provided with a surface finish that diffusely reflects light.