JPH0814901B2 - Accidental erasure prevention detector - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an erroneous erasure prevention detection device for a cassette tape recorder.

2. Description of the Related Art FIG. 2 shows a cassette tape recorder of recent years. Second
As shown in the figure, the set size is determined by the thickness T
Was determined by the cassette tape 1 and the motor 7, the height H was determined by the width of the cassette tape 1, and the width D was determined by the cassette tape 1 and the magnetic head 8. Particularly, for a cassette tape recorder having a general recording function, the erroneous erasure prevention detection piece 3 is configured as shown in FIG. 3, and the width D is the width of the cassette tape 1.
Was determined by the magnetic head 8 and the erroneous erasure detection piece 3.

In FIG. 3, the detection piece 3 is rotatable around a rotation fulcrum 3c provided on the mechanism substrate 2, and the hole detection portion 3a provided at one end thereof is attached to the cassette tape mounting portion of the cassette tape 1 Opposite the erasure prevention detection hole 1a at the rear end of the
A locking portion 3b provided at the other end is urged to rotate by a spring 9 so as to face the recording lever 4.

In the erroneous erasure prevention detection device having such a configuration, the erasure prevention detection hole 1a provided at the rear end of the cassette tape 1 is provided with the prevention piece 1b.
In this case, the detection portion 3a at one end of the detection piece 3 does not come into contact with the prevention piece 1b and the locking portion 3b at the other end is not located within the movement locus of the recording lever 4, and the recording function is exhibited. On the other hand, the detection hole
When the prevention piece 1b is not provided in 1a, the detection portion 3a at one end of the detection piece 3
Enters into the detection hole 1a and the locking portion 3b at the other end is positioned on the movement locus of the recording lever 4 and prohibits the recording lever 4 from being pushed in to prevent the recording function.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, as described above, the size X, which the erroneous erasure prevention detection mechanism is configured to reduce the size of the recording function set, becomes a bottleneck, and it is difficult to reduce the size. It was That is, in the conventional device, since the detection piece 3 is located behind the cassette tape 1 and rotates about the rotation fulcrum 3c in the thickness direction of the set, the detection portion 3a at one end of the detection piece 3 inserts and removes the cassette tape. Due to the nature, it is necessary to form a wedge-shaped portion, which has a drawback that the rearward dimension of the cassette tape 1 becomes large.

Means for Solving the Problems The erroneous erasure prevention detection device of the present invention has a rotation center in the thickness of the cassette tape and in the longitudinal direction behind the cassette tape loaded in the cassette tape mounting portion, One end is arranged so as to face the other end of the detection piece, which is configured so that it can be put in and taken out from the erroneous erasure prevention detection hole of the cassette tape, and it is engaged with the other end of this detection piece and always engages with the other end of the detection piece. One end of the detection piece is provided with a leaf switch for urging the one end to enter the erroneous erasure prevention detection hole and a spring for pressing the cassette tape to the magnetic head side. Is urged in a direction to come out of the erroneous erasure prevention detection hole, and when the cassette tape is loaded, the urging by the spring is released and one end of the detection piece is erroneously erasure prevention detection hole by the urging of the leaf switch. The urging force of the leaf switch is set to be smaller than the urging force of the spring so that the leaf switch is urged in the entering direction.

The present invention has the above-described structure, and the detection piece provided on the rear portion of the cassette tape prevents the detection piece from coming into contact with the mistake deletion prevention hole at the same time when the cassette tape is inserted. The wedge shape is not required and the arrangement space can be minimized. Therefore, the erasure prevention detection piece rotates depending on the presence or absence of the prevention piece in the detection hole.If it is not present, the biasing force of the tape retainer spring is released and the leak switch is turned on to enable recording, and if it is present, The biasing force of the leaf switch causes the detection piece to rotate, turning the leaf switch off and disabling recording.

Embodiment An embodiment of the present invention will be described with reference to FIG. FIG. 1 is a perspective view of an erroneous erasure prevention detection device according to an embodiment of the present invention,
1a is an erroneous erasure prevention detection hole of the cassette tape 1, and 1b is a prevention piece in the hole. Reference numeral 2 denotes a drive mechanism substrate which rotatably holds a rotation fulcrum portion 3c of an erroneous erasure prevention detection piece 3 in a fulcrum receiving portion 2a. Reference numeral 3a denotes a hole detection portion of the erroneous erasure prevention detection piece 3, which rotates depending on the presence or absence of the erroneous erasure prevention hole piece 1a of the cassette tape 1, and 3b engages with the movable piece 5a of the leaf switch 5 in response to the rotation. ON / O for leaf switch 5
It is an engaging portion that performs FF. Reference numeral 4 is a tape pressing spring that presses the cassette tape 1 toward the magnetic head by the cassette tape contact portion 4a. The detection piece 3 is urged in the direction opposite to the arrow direction, and when the cassette tape is mounted, the position becomes the solid line position, and the urging force on the detection piece 3 is released. Further, the biasing force of the leaf switch 5 on the detection piece 3 is set to be smaller than the biasing force of the tape pressing spring 4 on the detection piece 3. Reference numeral 6 is a printed wiring board on which the leaf switch 5, electric parts 7, etc. are mounted.

Next, the operation will be described. If no cassette tape is attached,
Detecting piece 3 by the biasing force of tape retainer spring 4 (two-dot chain line)
Indicates the solid line position, and the leaf switch 5 is turned on to enable recording.

When the cassette tape is mounted, the tape pressing spring 4 is in the position indicated by the solid line, and the biasing force on the detection piece 3 is released. Therefore, if the erroneous erasure prevention piece 1b of the cassette tape 1 is not present, the erroneous erasure prevention hole detection section 3a hits the erroneous erasure prevention piece 1b and becomes the solid line position to turn on the leaf switch 5 to enable the recording, while the erasure prevention When the piece 1b is provided, the erroneous erasure prevention detection piece 3 is rotated in the direction of the arrow by the leaf switch 5 to the position indicated by the chain double-dashed line in the figure, and the leaf switch 5 is
It is turned off and recording is disabled. In this way, the erroneous erasure prevention detection mechanism can be configured only by the space x dimension of the rotation fulcrum portion 3c of the erroneous erasure prevention detection piece 3.

EFFECTS OF THE INVENTION As described above, according to the present invention, there is a detection piece which has a rotation center in the height direction within the thickness behind the cassette tape and one end of which can be inserted into and removed from the erroneous erasure prevention detection hole of the cassette tape. Then, the other end of the detection piece is engaged with a leaf switch for enabling / disabling recording so that one end of the detection piece is always biased to enter the erroneous erasure prevention hole, and a spring for pressing the cassette tape to the magnetic head side. When the cassette tape is not attached, one end of the detection piece is urged in the direction to come out of the erroneous erasure prevention detection hole, and when the cassette tape is attached, the urging force of the spring is released, but the urging force of the leaf switch is the urging force of the spring. Since it is set smaller than the force, the erroneous erasure prevention detection mechanism can be configured only by the space x size of the rotation fulcrum portion of the detection piece, and the effect of reducing the size and thickness of the cassette is great.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of an erroneous erasure prevention detecting device of the present invention, FIG. 2 is a perspective view showing a conventional cassette tape recorder, and FIGS. 3a and 3b are conventional erroneous erasure prevention detecting mechanisms. FIG. 4 is a front view and a cross-sectional view thereof. 1b …… Erroneous erasure prevention piece, 3 …… Erroneous erasure prevention detection piece, 3a ……
Hole detecting part, 3b ... Locking part, 3d ... Engaging part, 4 ... Tape pressing spring, 4b ... Engaging part, 5 ... Leaf switch.

Claims (1)

[Claims] 1. A cassette tape to be loaded in a cassette tape loading portion has a center of rotation in the thickness of the cassette tape and in the longitudinal direction, and one end of the cassette tape can be inserted into and removed from an erroneous erasure prevention detection hole of the cassette tape. The detection piece is arranged so as to face the other end of the detection piece, engages with the other end of the detection piece, and always urges one end of the detection piece to enter the erroneous erasure prevention detection hole. A leaf switch for deciding whether or not recording is possible, and a spring for pressing the cassette tape to the magnetic head side, and one end of the detection piece is urged in a direction out of the erroneous erasure prevention detection hole when the cassette tape is not loaded. When the cassette tape is loaded, the urging force of the spring is released, and the urging force of the leaf switch urges one end of the detection piece in the direction of entering the erroneous erasure prevention detection hole. Pitch of the biasing force is biasing force set erase prevention detection device erroneously, characterized in that is smaller than the spring.