JPS63205838A - Detector for erroneous erasing prevention - Google Patents

Abstract

PURPOSE:To obtain a miniaturized and thinned cassette by constituting the titled detector so that the foremost end part of an erroneous erasing prevention detecting piece can be inserted/pulled out in/from a detection hole and is connected with a leaf switch. CONSTITUTION:A hole detection part 3a of the erroneous erasing prevention detection piece 3 held at a supporting point 3c can be freely inserted into the detection hole 1a of a cassette 1. By loading the cassette, a tape pressing spring 4 is allowed to retreat, and the detection piece 3 is released from the energization. If the erroneous erasing prevention piece 1b is not broken, the detection part 3a is brought into contact with the piece 1b turning on the leaf switch 5, and the equipment enters the sound recording state. If the piece 1a is broken, the piece 3 is inserted into the hole 1a turning off the switch 5, and the sound recording it made unable state. Accordingly, the necessary space is only a space X for the rotation of the detection piece 3, hence the miniaturized and thinned cassette can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an accidental erasure prevention detection device for a cassette tape recorder.

Conventional technology A recent cassette tape recorder is shown in FIG.

As shown in Fig. 2, the set size is determined by the thickness T by the cassette tape 1 and the motor 7, the height H by the width of the cassette tape 1, and the width by the cassette tape 1. 1 and the magnetic head 8. In particular, for cassette tape recorders with a general recording function, an accidental erasure prevention detection piece 3 is constructed as shown in Figure 3, and the width is the same as that of a cassette tape.
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 board 2, and a hole detection part 3a provided at one end of the detection piece 3 is inserted into the cassette tape mounting part. A locking portion 3b provided at the other end, facing the erroneous erasure prevention detection hole 1a at the rear end, is biased by a spring 9 to rotate so as to face the recording lever 4.

In the accidental erasure prevention detection device having such a configuration, a prevention piece 1 is inserted into the accidental erasure prevention detection hole 1a provided at the rear end of the cassette tape 1.
b, the detection part 3a at one end of the detection piece 3 is connected to the prevention piece 1.
b, the locking portion 3b at the other end is not located within the movement locus of the recording lever 4, and performs the recording function. On the other hand, when the detection hole 1a does not have the prevention piece 1b, the detection part 3a at one end of the detection piece 3 enters into the detection hole 1a, and the locking part 3b at the other end is located in the movement locus of the recording lever 4, and the recording lever 4 is moved. The recording function is blocked by prohibiting the lever 4 from being pressed.

Problems to be Solved by the Invention However, as described above, the size X of the accidental erasure prevention detection mechanism becomes a bottleneck in downsizing a set with a recording function, making it difficult to downsize. Ta. That is, in the conventional device, the detection piece 3 is located at the rear of the cassette tape 1 and rotates around the rotation fulcrum 3C in the thickness direction of the set, so the detection part 3a at one end of the detection piece 3 is bent. However, the rear dimension of the cassette tape 1 becomes large.

Means for Solving the Problems The accidental erasure prevention detection device of the present invention has a rotation center in the height direction within the thickness of the cassette tape at the rear of the cassette tape loaded in the cassette tape loading section, and one end is connected to the cassette tape. A detection piece configured to be able to be put in and taken out of the detection hole for preventing accidental erasure, and a detection piece arranged to face the other end of the detection piece, and engaged with the other end of the detection piece to prevent one end of the detection piece from being erased accidentally. It is equipped with a leaf switch that is energized to enter the prevention detection hole to determine whether or not recording is possible, and a spring that presses the cassette tape toward the magnetic head, and one end of the detection piece prevents accidental erasure when the cassette tape is not loaded. It is energized in the direction coming out from the detection hole,
When loading a cassette tape, the biasing force of the leaf switch is changed so that the biasing force of the spring is released and the biasing force of the leaf switch biases one end of the detection piece in the direction of entering the erroneous erasure prevention detection hole. It is characterized by being set smaller than the applied force of the spring.

Function: With the above-described configuration, the present invention can minimize the space required for erroneous erasure prevention detection mechanism provided at the rear of the cassette tape. Accordingly, the accidental erasure prevention detection piece rotates depending on the presence or absence of the prevention piece in the detection hole, and if there is no prevention piece, the biasing force of the tape pressing spring is released and the leak switch is turned on.
If it is present, the detection piece rotates due to the force of the leaf switch and the leaf switch is turned OFF, making it impossible to record.

EXAMPLE An example of the present invention will be explained with reference to FIG. FIG. 1 is a perspective view of an accidental erasure prevention detection device according to an embodiment of the present invention.
a is the detection hole for preventing accidental erasure of the cassette tape 1, and 1b
is the prevention piece inside the hole.

Reference numeral 2 denotes a driving mechanism substrate, which rotatably holds the rotational fulcrum portion 3C of the erroneous erasure prevention detection piece 3 at the fulcrum receiving portion of 2a. Reference numeral 3a designates a hole detecting portion of the detection piece 3 for preventing accidental erasure, which rotates depending on the presence or absence of the hole piece 1a for preventing accidental erasure on the cassette tape 1, and 3b engages with the movable piece 5a of the leaf switch 5 in response to the rotation. This is a retaining part that keeps the leaf switch 5 0N10FF. 4 is a tape pressing spring that presses the cassette tape 1 toward the magnetic head side by means of a cassette tape holding part 4a, and when the cassette tape is not installed, an engaging part of the detection piece 3 is held by a retaining part 4b as shown by the two-dot chain line in the figure. The detection piece 3 urges the detection piece 3d in the opposite direction to the direction of the arrow, and when the cassette tape is loaded, the detection piece 3 reaches the solid line position and the urging force on the detection piece 3 is released. Further, the biasing force of the leaf switch 6 against the detection piece 3 is set smaller than the biasing force of the tape pressing spring 4 against the detection piece 3.

6 is a printed wiring board, and a leaf switch 5 is mounted on this board.
．． Electrical components 7 and the like are mounted.

Next, the operation will be explained. When the power running tape is not attached, the detection piece 3 is moved to the solid line position by the force of the tape presser spring 4 (double-dashed line), and the leaf switch 5 is turned on, making it possible to record.

When the cassette tape is loaded, the tape pressing spring 4 moves to the solid line position and the biasing force against the detection piece 3 is released. If the cassette tape 1 does not have the erasure prevention piece 1b, the accidental erasure prevention hole detection part 3a will hit the accidental erasure prevention piece 1b and will be at the solid line position, turning on the leaf switch 5 and becoming ready for recording. When the piece 1b is down, the accidental erasure prevention detection piece 3 is rotated in the direction of the arrow by the leaf switch 5 to the position indicated by the two-dot chain line in the figure, and the leaf switch 5 is turned OFF, making recording impossible.

In this way, the erroneous erasure prevention detection mechanism can be configured only by the space I dimension of the rotation fulcrum portion 3C of the erroneous erasure prevention detection piece 3.

Effects of the Invention As described above, the present invention has a detection piece located at the rear of the cassette tape, which has a center of rotation in the height direction within the thickness, and whose one end can be inserted into and taken out from the detection hole for preventing accidental erasure of the cassette tape. The other end of this detection piece is engaged with a leaf switch that enables or disables recording, and is energized so that one end of the detection piece always enters the accidental erasure prevention hole, and a spring that presses the cassette tape toward the magnetic head side. When the cassette tape is not installed, one end of the detection piece is biased in the direction of coming out of the accidental erasure prevention detection hole, and when the cassette tape is loaded, the biasing force by the spring is released, but the biasing force of the leaf switch is the same as that of the spring. Since it is set smaller than the auxiliary force, the space X of the rotation fulcrum of the detection piece
A detection mechanism for preventing accidental erasure can be constructed using only the dimensions.
Small cassette.

The effect on thinning is significant.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the accidental erasure prevention detection device of the present invention, FIG. 2 is a perspective view of a conventional cassette tape recorder, and FIGS. 3a and 3b are conventional accidental erasure prevention detection mechanisms. FIG. 2 is a front view and a sectional view thereof. 1b... Erroneous erasure prevention piece, 3... Erroneous erasure prevention detection piece, 3a... Hole detection section, 3b...
...Locking part, 3d...Engagement part, 4...
Tape presser, 4b... Engagement part, 5...
...Leaf switch. Name of agent: Patent attorney Toshio Nakao and 1 other person1-
3J-Engagement part I and others):F7 stopper 4-Tape push-in spring? −
Mainism board #-F1! Cuttable part? . −
Bunbe, receiving threat 4-Engagement part 2III-“holding part 5-leaf switch 3
--Error
5 Mu - [Constant 7γ3 Mu 1 main part 6 - Busonto base 3C - Rotating force, Xun 7... Electrical parts 1st
Figure 2

Claims (1)

[Claims] a detection piece having a rotation center within the thickness and in the height direction behind the cassette tape loaded in the cassette tape loading section, and having one end configured to be inserted into and taken out from an accidental erasure prevention detection hole of the cassette tape; It is arranged to face the other end of the detection piece, and determines whether or not recording is possible by engaging the other end of the detection piece and always energizing one end of the detection piece to enter the detection hole to prevent accidental erasure. and a spring that presses the cassette tape toward the magnetic head. When the cassette tape is not loaded, one end of the detection piece is energized in the direction of exiting from the accidental erasure prevention detection hole, and when the cassette tape is loaded. The biasing force of the leaf switch is greater than the biasing force of the spring so that the biasing force of the leaf switch is released and the biasing force of the leaf switch biases one end of the detection piece in the direction of entering the mistaken erasure prevention detection hole. A detection device for preventing accidental erasure, characterized in that the detection device is also set small.