JPS6154089A - Tape cassette - Google Patents

Abstract

PURPOSE:To make a tape cassette non-black and prevent erroneous detection at a start and finish of a tape by composing a tape reel with a material to permeate an external light of the waveform of a special scope. CONSTITUTION:A color of a tape cassette main body 1 is made non-black, and when the tape cassette is used outside the room where a direct sunlight falls and inside the room where a light source including the wavelength of a near-infrared ray falls, an external light 11 of the waveform of a 700nm-1,000nm scope, permeates from the upper surface of the non-black tape cassette main body 1. The external light 11 permeates upper flanges 12a and 12b on the tape reels 2a and 2b and reaches lower flanges 13a and 13b and however, since lower flanges 13a and 13b are also transparent, the external light 11 permeates, reaches the lower surface of the tape cassette main body and permeates. Consequently, the external light 11 reflects at the lower flange of the tape reels 2a and 2b and reaches respective light receiving elements 8 and 9 and erroneous detection at the start and finish end of the VTR tape can be prevented, and therefore, the color of the tape cassette main body 1 can be non-black.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a tape cassette suitable for application to recording and reproducing devices such as video tape recorders and various other information processing devices, and particularly to a tape cassette suitable for use in devices that perform optical detection. It concerns tape cassettes.

゛Conventional structure and problems thereof A conventional tape cassette will be explained with reference to FIGS. 2 to 4.

FIG. 2 shows the structure of an 8mm video tape cassette, in which a pair of tape reels (2a) (zb) wound with tape (3) are housed in the tape cassette body (1).

In addition, there is a tape (
3) are provided with two-piece lids (4) and (5) for protecting the parts. Also, on the top of the tape cassette body (1) there is a
! (6) is provided.

Figure 3 shows that the tape cassette is connected to a video tape recorder (
A diagram of the internal structure when installed in a VTR (hereinafter referred to as a VTR),
FIG. 4 is a longitudinal cross-sectional view along the optical path XX' (FIG. 3) with the tape cassette attached to the VTR.

Detection of the beginning and end of the tape (3) will be explained using FIGS. 3 and 4.

A leader tape through which near-infrared rays can easily pass is bonded to the longitudinal end of the tape (3).

When the tape cassette is installed in the VTR, light is emitted from the tape start/end detection light source (7) located on the VTR side in the hole (1a) provided in the center of the tape cassette body (1). The generated near-infrared light (10) passes in this order through the notch (lb) in the position regulating wall of the tape cassette body (1), the tape (3), and the notch (1c) in the side wall on both the winding side and the supply side, and then passes through the VTR. It reaches the winding side light receiving element (8) and the supply side light receiving element (9) provided on the side. On the supply side when the tape cassette is at the starting end (no tape (3) on the take-up tape reel (2a)), the magnetic tape with low light transmittance is located on the tape (3) that is in contact with the light (10). The light (10) is absorbed and does not reach the light receiving element (9) on the supply side, and the leader tape with high light transmittance is placed on the tape (3) in contact with the light (10) on the winding side. 10) is transmitted and reaches the winding side light receiving element (8). Therefore, the VTR detects that the tape cassette is at the beginning of the tape. On the take-up side when the tape cassette is at its end (no tape (3) on the supply tape reel (2b)), the tape (3) is in contact with the light (10).
), the light (10) is absorbed and does not reach the winding-side light receiving element (8), and on the supply side, the leader tape is located at the tape (3) that is in contact with the light (10). Therefore, the light (lO) is transmitted through the supply side light receiving element (8
). Therefore, the VTR detects that the tape cassette is at the end of the tape. When the tape cassette is in a state other than the beginning and end, the light (l) is located on the tape (3) which is in contact with the light (10) on the winding side and the supply side.
O) does not reach the light receiving elements (8) and (9) on the winding side and the supply side, so the VTR does not detect that the tape cassette is at the beginning or end of the tape.

By the way, when the tape cassette is used outdoors where it is exposed to direct sunlight (hereinafter referred to as external light) or indoors where it is exposed to a light source containing near-infrared wavelengths (hereinafter referred to as external light), especially on the winding side as shown in Figure 4. When there is little tape (3) on the tape reel (2a) (but not at the starting end), external light with a wavelength in the range of 70Qnm to 11000n (
11) passes through the window (6) of the tape cassette and the top surface of the tape cassette body (1), enters the tape cassette, passes through the upper flange of the first winding side tape reel (2a), is reflected on the lower flange, and is wound. It reaches the receiving side light receiving element (8). Therefore, even though the tape cassette is not at the beginning of the tape, the VTR erroneously detects that the tape is at the beginning. Further, even when there is not enough tape (3) on the supply tape reel (2b) (however, it is not at the end), the VTR will erroneously detect the tape as described above. Therefore, in order to prevent the above-mentioned erroneous detection of the VTR, the tape cassette body (1) is colored black to absorb external light (11) and reduce the amount of light entering the tape cassette.

For the above reasons, the non-black tape cassette body allows the external light (11) to pass through and reflects it inside the tape cassette.
It cannot be used because it causes false detection of TR.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional problems, and aims to provide a tape cassette that is non-black and does not cause false detection.

Structure of the Invention In order to achieve the above object, the tape cassette of the present invention has the following features:
Inserting the tape reel from above the tape cassette body 7
It is made of a material that transmits external light having a wavelength in the range of 00 nm = 1000 nm.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings (FIG. 1). FIG. 1 is a longitudinal cross-sectional view of a tape cassette according to an embodiment of the present invention taken along an optical path when it is attached to a VTR.

In the figure, the tape reel on the 1st winding side and the supply side (2a
) and (2b) are made of transparent material.

Since the other configurations are the same as those of the conventional example, the explanation will be omitted.

When the color of the tape cassette body (1) is made non-black and the tape cassette is used outdoors where it is exposed to direct sunlight (hereinafter referred to as external light) or indoors where it is exposed to a light source containing near-infrared wavelengths (hereinafter referred to as external light) , 700 nm = 10
External light (11) with a wavelength in the range of 00 nm is transmitted through the top surface of the tape cassette body (1), which is non-black. Then, the external light (11) passes through the upper flanges (12a) (12b) of the tape reels (2a) (2b) and reaches the lower flanges (13a) (13b) L, but the lower flanges (13a) (13b) ) is also transparent so it lets in extraneous light (11)
passes through, reaches the bottom surface of the tape cassette body (1), and passes through. Therefore.

Conventionally, the external light (11) was reflected by the lower flanges and jis of the tape reels (2a) and (2b) and reached each light receiving element (8) and (9), causing the VTR to incorrectly detect the beginning and end of the tape. Since this can be prevented, the color of the tape cassette body (1) can be made non-black.

Effects of the Invention As described above, according to the present invention, a tape reel of 700n
By using a material that transmits external light having a wavelength in the range of m-1000 nm, it is possible to provide a tape cassette whose main body is non-black in color and which does not cause false detection. Therefore, young colors can be produced for each purpose and sorting can be done easily. Furthermore, if the tape cassette body is colored in a non-black color that reflects near-infrared rays, thermal deformation caused by direct sunlight will be reduced.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a tape cassette according to an embodiment of the present invention, Fig. 2 is a plan view of a conventional 8 mm video tape cassette, and Fig. 3 is a view of the tape cassette installed in a VTR. The internal structure diagram, FIG. 4, is a longitudinal sectional view taken along the optical path xx' shown in FIG. (1)... Tape cassette body, (la) = hole -
(lb) (lc)...notch, (2a)...take-up tape reel, (2b)...supply tape reel, (3)...tape, (6)...window, (7)...
Light source for detecting tape start and end ends, (8)... Winding side light receiving element, (9)... Supply side light receiving element, (10)... Light,
(11)... Extraneous light, (12a) (12b)...
Upper flange, (1:1a) (1:lb)...lower flange

Claims (1)

[Claims] 1. A pair of tape reels wound with magnetic tape are housed in a tape cassette body, and a light source for detecting the beginning and end of the tape is inserted into the tape cassette body through a through hole provided in the tape cassette body. In the tape cassette, the light receiving path is formed to guide the detection light of 700 nm to the light receiving element through the magnetic tape stretched between the tape reels. A tape cassette made of a material that transmits external light with a wavelength in the 1000 nm range.