JPH04311808A - Tape cassette - Google Patents

Abstract

PURPOSE:To facilitate the detection of the start end and the end of the tape, to unnecessitate a leader tape or a trailer tape fixing the tape to a winding and a supply reel and to improve the productivity of the tape cassette, in the tape cassette housing the magnetic tape having a light transparency. CONSTITUTION:On the end and the start end of the magnetic tape 10 having a light transparency, a bright part 15 holding the same characteristics as the recording and reproducing part and a dark part 16 having lower mirror face reflectance of light are provided. Also a light emitting element 17 and a light receiving element 18 receiving the reflected light from the tape are provided on a tape conveying course of the magnetic recording and reproducing device. Then when the magnetic tape 10 to decreased at the other side of the reel of the tape cassette, the reflected signals from the bright part 15 and the dark part 16 obtained at the light receiving element 18 change, so the start end and the end of the tape are detected.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape cassette used in a magnetic recording/reproducing device.

0002

[Prior Art] Tape cassettes used in conventional magnetic recording and reproducing devices generally have a structure in which the beginning or end of the magnetic tape is connected to a transparent tape, as shown in Utility Model Application No. 53-51128. It is. FIG. 5 is an explanatory diagram showing the configuration of the starting and ending ends of a magnetic tape in a conventional tape cassette. In the magnetic tape 1, a transparent leader tape 1b and a transparent trailer tape 1c are connected to both ends of a recording/reproducing section 1a having a magnetic layer, respectively. The leader tape 1b is fixed to the take-up reel of the tape cassette, and the trailer tape 1c is a tape fixed to the supply reel.

FIG. 6 is an explanatory diagram showing an example of the travel path of the magnetic tape 1 in which a tape cassette is attached to a magnetic recording/reproducing apparatus. A magnetic tape 1 pulled out from a supply reel 2 of a tape cassette is conveyed through a tape post and a recording head mechanism, and is wound onto a take-up reel 3. Here, a light emitting element 4 and a light receiving element 5 are provided on the tape transport path so as to face each other with the magnetic tape 1 interposed therebetween. Now, the magnetic tape 1 is wound onto the take-up reel 3 in playback mode,
When the magnetic tape 1 on the supply reel 2 runs out, the trailer tape 1c passes between the light emitting element 4 and the light receiving element 5. Further, at the end when the magnetic tape 1 is conveyed from the take-up reel 3 to the supply reel 2 side in the rewind mode, the leader tape 1b passes. Therefore, leader tape 1b, trailer tape 1
The end of the tape was detected based on changes in the transmitted light.

0004

[Problems to be Solved by the Invention] However, as recording and reproducing equipment becomes smaller and thinner, the magnetic layer of magnetic tape becomes shallower and thinner, increasing the recording density, and the base film becomes thinner to lengthen the recording and reproducing time. For these reasons, the magnetic tape itself also allows light to easily pass through it. For this reason, it has become difficult to detect the beginning and end of a magnetic tape by utilizing the difference in light transmittance. In addition, in conventional tape cassettes in which a leader tape 1b and a trailer tape 1c are connected to both ends of a magnetic tape recording/reproducing section 1a, the connection strength is not sufficient, and care must be taken in the tape connection process. There was a problem.

The present invention solves these conventional problems, and provides a tape that enables the detection of the starting and ending ends of a magnetic tape formed from a light-transmissive magnetic layer. An object of the present invention is to provide a tape cassette having a magnetic tape that does not require a leader tape and a trailer tape that are fixed to a take-up reel and a supply reel.

[0006]

[Means for Solving the Problem] The invention according to claim 1 of the present application provides a magnetic tape, a tape supply reel and a tape take-up reel for winding the magnetic tape, and a tape supply reel and a tape take-up reel. In the tape cassette comprising a holding cassette half, the magnetic tape is a light-transparent tape having a magnetic layer formed on one side of a base film and a protective film formed on the other side of the base film. At least one of the magnetic layer or the protective coating in a specific range of both terminals fixed to the tape supply reel and take-up reel of the magnetic tape has a plurality of dark areas with low light reflectance and a bright area sandwiched between the dark areas. It is characterized by having a section.

The invention according to claim 2 of the present application comprises a magnetic tape, a tape supply reel and a tape take-up reel for winding the magnetic tape, and a cassette half that holds the tape supply reel and the tape take-up reel. In the tape cassette, the magnetic tape is a light-transmissive tape in which a magnetic layer is formed on one side of a base film and a protective film is formed on the other side of the base film,
It is characterized in that a plurality of magnetic layers for detecting terminals having magnetic characteristics different from those of the recording/reproducing section are provided on the magnetic layers in a specific range of both terminals fixed to the tape supply reel and take-up reel of the magnetic tape. be.

[0008]

[Operation] According to the invention of claim 1 of the present application having such features, when the tape cassette is mounted on the magnetic reproducing/recording device and the magnetic tape is run, the magnetic tape on the tape take-up reel or the supply reel is small. As a result, the light reflectance of the dark areas at both end portions of the magnetic tape and the area sandwiched between the dark areas changes. Therefore, when the recording and reproducing section finishes running, it is possible to detect the end of the tape when passing through a dark area.

According to the invention of claim 2 of the present application, when a plurality of end detection magnetic layers provided at the beginning or end of a magnetic tape are reproduced by a fixed magnetic head, the reproduction noise changes. Therefore, when the recording and reproducing section finishes running, the end of the tape can be detected by detecting an increase in reproduction noise by passing through the end detection magnetic layer.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a first embodiment of the present invention will be described with reference to the drawings. 1 and 2 are explanatory diagrams showing the structure of a magnetic tape wound around a reel in a tape cassette in one embodiment of the present invention. In FIG. 2, a magnetic tape 10 has a base film 11, a magnetic layer 12 formed on one surface, and a protective coating 13 formed on the other surface. The magnetic layer 12 is thin and has light transparency due to the characteristics of its magnetic material. In addition, both the base film 11 and the protective coating 13 are transparent, and in the tape cassette described later, the magnetic tape 1 is used without using a leader tape or trailer tape.
0 is fixed directly to each reel within the cassette.

In this embodiment, as shown in FIG. 1, a bright portion 15 and a dark portion 16 having different light reflectances are provided at the beginning or end of the magnetic tape 10 fixed to the reel 14, respectively. The dark portion 16 has a constant width in the longitudinal direction of the tape, and is a portion where the surface roughness of the magnetic layer 12 or the protective coating 13 is roughened. The bright area 15 is a part that maintains the same structure as the recording/reproducing part of the magnetic tape 10, and the surface roughness of the protective coating 13 and the magnetic layer 12 in that part is small and smooth. The width and pitch of the bright portion 15 and the dark portion 16 are the same at the beginning and end of the magnetic tape 10, respectively. Further, a light emitting element 17 and a light receiving element 18 are mounted at a position close to the protective coating 13 of the magnetic tape 10 in a part of the tape transport path so that the angle of incidence and angle of reflection relative to the magnetic tape 10 are equal. These elements 17 and 18 constitute a reflective photosensor. The light-receiving element 18 receives the light emitted from the light-emitting element 17 and reflects it on the surface of the magnetic tape 10, and converts it into an electrical signal, and its output is connected to a waveform shaping circuit (not shown). .

FIG. 3 is a plan view and a side view showing the appearance of the tape cassette. In this figure, the tape cassette 20 has an upper half 21a and a lower half 2, as shown in FIG. 3(b).
1b, which holds a supply reel 22 and a take-up reel 23, respectively, and the magnetic tape 10 wound on each reel is externally exposed from the opening 25 of the tape through the fixed posts 24a and 24b in the tape cassette 20. It is designed to guide you. A front lid 26 is provided at the tape opening 25, and when the tape cassette 20 is installed in the main body of the magnetic recording/reproducing apparatus, the front lid is closed so that the magnetic tape 10 can be wound around the head mechanism by an engaging means (not shown). 26 is rotatably attached. Also, a transparent plate 2 is attached to a part of the upper half 21a.
7 is formed so that the remaining amount of the magnetic tape 10 on each reel 22, 23 can be confirmed.

Tape cassette 2 constructed as above
0 is attached to the main body of the magnetic recording/reproducing apparatus, and when the magnetic tape 10 is run to perform a recording or reproducing operation, the supply reel 22
The magnetic tape 10 pulled out from the magnetic tape 10 is wound onto a take-up reel 23 via a head mechanism section. At that time, as shown in FIG.
receives reflected light from the light emitting element 17. That is, the magnetic layer 12 of the signal recording portion of the tape is transparent to light and has a surface roughness close to a mirror surface, so that the light receiving element 18 constantly receives reflected light during recording and reproduction. As the tape on the supply reel 22 approaches the end, the bright area 15 and dark area 16 of the magnetic tape 10 become light emitting elements 17 and light receiving elements 18.
pass in front of. When the light passes through the dark area 16, the amount of light incident on the light receiving element 18 decreases. Therefore, magnetic tape 10
It is detected that the end or start end of the tape has passed, and the operation of the tape conveying means and the rotating head can be stopped. Here, the dark area 16 of the magnetic tape 10 does not mean that another member is newly attached to the surface of the magnetic layer 12 or the protective coating 13. Even if it reaches the head, it will not adversely affect the rotating head. Furthermore, there is no need to fix both ends of the magnetic tape 10 to a supply reel or a take-up reel via a leader tape or trailer tape, resulting in a tape cassette with excellent productivity.

FIG. 4 is a diagram showing the configuration of a magnetic tape terminal according to the second embodiment. In this figure, a plurality of blocks 3 are formed near the start and end of the magnetic tape 10 as magnetic layers for terminal detection having different magnetic properties from the magnetic layer 12 of the recording/reproducing section.
1 will be provided. The magnetic layer 12 of the block 31 is constructed by, for example, changing the thickness of the magnetic material or the particle size of the magnetic powder, and is formed to have a constant width and pitch in the longitudinal direction of the tape. Between these blocks 31, blocks 32 are provided which maintain the characteristics of the normal magnetic layer 12 in the recording/reproducing section of the magnetic tape 10. Next, a fixed magnetic head 33 is provided at a position in contact with the magnetic layer 12 on the tape transport path. The fixed magnetic head 33 is a head that detects changes in magnetic characteristics such as tape hiss noise at the beginning and end of the magnetic tape 10, and is configured to obtain different reproduction outputs from the blocks 31 and 32. When a tape cassette configured as described above is used in a magnetic recording/reproducing device, when the tape on the supply reel 22 or the take-up reel 23 approaches the end, the end of the tape is detected by the change in the playback output obtained from the blocks 31 and 32. can do. In this embodiment as well, the block 31 of the magnetic tape 10 is the magnetic layer 1.
2 and the protective coating 13, the same effects as in the first embodiment described above can be obtained. Note that it is also possible to use an MR element, a Hall element, or the like instead of the fixed magnetic head 33 to detect the passage of the blocks 31 and 32 having different magnetic characteristics.

In the first and second embodiments described above, the bright portion 15, the dark portion 16, and the blocks 31, 32 have the same width in the longitudinal direction at the beginning and end of the magnetic tape 10, and are formed at the same pitch. , by varying these widths,
The starting end and the ending end of the magnetic tape 10 can be detected separately.

[0016]

Effects of the Invention As described above in detail, according to the invention of claim 1 of the present application, a plurality of dark areas with low light reflectance are provided in at least either the magnetic layer or the protective coating of the magnetic tape. Accordingly, the end of a thin magnetic tape can be easily detected using a reflective photosensor formed of a light emitting element and a light receiving element. According to the invention of claim 2 of the present application, a plurality of magnetic layers for detecting terminals having different magnetic properties from those of the recording/reproducing section are provided in specific ranges of both terminals fixed to the tape supply reel and the take-up reel. Even if magnetic tapes with different light transmittances and reflectances are used, the end of the tape can be accurately detected by the reproduction noise of the fixed magnetic detection element in the transport path. Also, claims 1 and 2 of the present application
In the invention, there is no need to fix both ends of the magnetic tape to the supply reel or take-up reel via other tapes such as leader tape or trailer tape, and the productivity of the tape cassette is improved without adversely affecting the rotating head. You can also get the effect of being able to improve.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a magnetic tape end of a tape cassette in a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing the structure of a magnetic tape in the first embodiment of the present invention.

FIG. 3 shows external views of a tape cassette according to the first embodiment of the present invention, in which (a) is a plan view and (b) is a side view.

FIG. 4 is an explanatory diagram showing the configuration of a magnetic tape terminal in a second embodiment of the present invention.

FIG. 5 is an explanatory diagram showing the configuration of a magnetic tape terminal in a conventional tape cassette.

FIG. 6 is a plan view showing a portion of a magnetic tape running path in a conventional tape cassette.

[Explanation of symbols]

10 Magnetic tape 11 Base film 12 Magnetic layer 13 Protective coating 14 Reel 15 Akebe 16 Dark part 17 Light emitting element 18 Photo receiving element 20 Tape cassette 21a Upper half 21b lower half 22 Supply reel 23 Take-up reel 26 Front lid 31, 32 block 33 Fixed magnetic head

Claims (2)

[Claims] 1. A tape cassette comprising a magnetic tape, a tape supply reel and a tape take-up reel for winding the magnetic tape, and a cassette half holding the tape supply reel and tape take-up reel, wherein the magnetic The tape forms a magnetic layer on one side of the base film,
A light-transmissive tape with a protective film formed on the other surface of the base film, the magnetic layer or the magnetic layer in a specific range at both ends fixed to the tape supply reel and take-up reel of the magnetic tape. A tape cassette characterized in that at least one of the protective coatings is provided with a plurality of dark areas with low light reflectance and a bright area sandwiched between the dark areas. 2. A tape cassette comprising a magnetic tape, a tape supply reel and a tape take-up reel for winding the magnetic tape, and a cassette half holding the tape supply reel and tape take-up reel, wherein the magnetic The tape forms a magnetic layer on one side of the base film,
A light-transmissive tape with a protective film formed on the other surface of the base film, the magnetic layer in a specific range of both ends fixed to the tape supply reel and take-up reel of the magnetic tape, A tape cassette characterized in that a plurality of terminal detection magnetic layers having magnetic properties different from those of a recording/reproducing section are provided.