JPS58139373A - Magnetic disc cassette - Google Patents

Abstract

PURPOSE:To attain the recording prevention and index detection, by forming at least a part of a magnetic disc cassette with a transparent body of light, transmitting and interrupting the light, and detecting rays at the side a recording and reproducing device. CONSTITUTION:At least a part of the magnetic disc cassette is formed with the transparent body of light. For example, a transparent part 1a is provided at the upper and lower part of the cassette around a recording prevention detection section to form the recording prevention mode through the presence/absence of the output of photocouplers 10, 11. A sheet 9 is sticked to interrupt the light. A transparent section is provided at the uper and lower part of the cassette at an index hole 8 and the index is detected with the photocouplers 10, 11 with a label 12 to be sticked. In sticking the label and sheet selectively at the transparent part of the cassette, the recording inhibition mode is attained or the index is detected. Thus, complicated openings of the cassette is made unnecessary and the change of the detection means at the device side is made easy.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic disk cassette, and more particularly to a magnetic disk cassette used in a magnetic disk device in which index detection and recording prevention are performed on the recording/reproducing device side.

A conventional magnetic disk cassette of this type is shown in FIG.

In FIG. 1, a magnetic disk cassette indicated by reference numeral 1 has a structure in which upper and lower cassette halves are butted against each other and fixed, and a magnetic disk 2 is housed inside, and is molded from synthetic resin or the like. This magnetic disk cassette 1
A circular center hole 3, which is one size larger than the circular hole 2a of the magnetic disk 2, is formed in the center thereof, and a head window 4 into which the magnetic head is fitted is formed at the front end side in the mounting direction to the apparatus. Further, index windows 5, 5 are formed on the left and right sides of the center hole 3, and a through hole 6 for preventing recording is formed in a part thereof. The reference numeral 8 indicates an index hole, and the reference numeral 7 indicates a liner for protecting the magnetic sheet attached to the inside of the cassette 1.

When a magnetic disk cassette with such a structure is used, a photosensor is provided on the device side, and various types of data can be detected using light beams that pass through the index window 5 and the through hole 6 for preventing recording. is in control.

However, if such a structure is adopted, as is clear from Fig. 1, an extremely large number of openings and through holes are formed, which complicates the structure of the cassette case, and furthermore, the detection location is located near the magnetic disk cassette 1. The disadvantage is that the position of the opening or through hole is determined by the position of the opening or through hole, and the degree of freedom in positioning various sensors provided on the device side is lost.

The present invention has been made in order to eliminate the above-mentioned drawbacks of the conventional magnetic disk cassette, and it simplifies the structure of the magnetic disk cassette by reducing the number of through holes and openings, and also increases the number of detection positions on the device side. It is an object of the present invention to provide a magnetic disk cassette that can be changed immediately in the event that it is necessary to make changes.

In order to achieve the above object, the present invention employs a structure in which at least a portion of the magnetic disk cassette is provided with a material that transmits light.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 2 explains one embodiment of the present invention. In this embodiment, at least a part of the cassette head constituting the magnetic disk cassette 1 is made of a transparent or light-transmissive material. It is said that The portion through which the light passes is, for example, the circumference that passes through the portion corresponding to the recording prevention through hole and the portion where the index hole 8 is present. The light-transmitting portion may be made of a different material, or the same material may be colored except for the light-transmitting portion.

When such a magnetic disk cassette is used, for example, the structure of the recording prevention detection section is shown in FIG. 3.

That is, a light-blocking sheet 9 is attached to the transparent or light-transmitting portion 1a of the magnetic disk cassette 1. When such a sheet 9 is attached, the optical path connecting the light emitting element and the light receiving element 11 provided on the device side is formed by the sheet 9.
As a result, no output is obtained from the light receiving element 11, and this can be used to put the apparatus into a recording prevention mode via a control circuit. In this way, if at least a part of the cassette has a certain area and is made into a part through which light can pass, detection by a detection means using a photosensor or the like can be performed simply by pasting the sheet 9 or the like at a predetermined position on this transparent part. Therefore, the position of the detection side and the mounting of the detection means can be extremely easily adjusted to increase or decrease in the number of detection means, and the degree of freedom in selection is increased.

Of course, not only a part but most or all of the part can be made into a part through which light can pass.

FIG. 4 explains another embodiment of the present invention. In this embodiment, for example, in order to improve index detection accuracy, a slit-shaped part is provided on the light receiving element 11 side of the above-mentioned light transmitting portion 1a. An example in which a label 12 is attached is shown.

In this way, index detection accuracy can be further increased.

Note that it is extremely convenient to attach or remove a label on the cassette side if the position is printed, for example, by surrounding it with a frame, or by printing in advance so that it can be peeled off by rubbing.

The embodiment shown in FIG. 5 exemplifies a case where a reflective photosensor is used as the detection means.

When such a photosensor is used, a label made of a material with excellent reflectance, such as aluminum foil, may be used as the sheet 9 attached to the light-transmitting portion.

As is clear from the above description, according to the present invention, since at least a portion of the magnetic disk cassette is formed of a light-transmitting material, it is not possible to selectively attach a label or the like to this portion. This provides an excellent effect in that it is possible to freely deal with changes or increases or decreases in the detection means on the apparatus side without complicating the cassette side by providing many through holes or openings.

[Brief explanation of drawings]

FIG. 1 is a plan view of a magnetic disk cassette explaining a conventional structure, FIG. 2 is a plan view of a magnetic disk cassette explaining an embodiment of the present invention, and FIGS. 3 to 5 show different usage patterns. It is a partially enlarged cross-sectional view shown. 1...Magnetic disc spacer) la...Light transmitting portion 2...Magnetic disk 3...Center hole 9...Sheet 10...Light emitting element

Claims (1)

[Claims] A magnetic disk cassette characterized in that at least a portion of the magnetic disk cassette is made of a light-transmitting material.