JPH0371459A - Cassette half detecting switch - Google Patents

Abstract

PURPOSE:To improve accuracy and reliability and to save a space by interposing an elastic member between a movable part and a fixed part and moving only the movable part against the pressing force of the elastic member when a large cassette half is inserted. CONSTITUTION:The switch is the one to detect detecting holes 8a and 9a for erroneous erasure detection and cassette class judgement provided at the cassette halves 8 and 9, and it is formed in two piece constitution of the movable part 15 and the fixed part 17, and the elastic member 16 is interposed between the movable part 15 and the fixed part 17. When the large cassette half 8 is inserted, an apex part 15b is pressed with the cassette half 8, and the movable part 15 is moved downward along the inner peripheral side wall of the fixed part 17 against the pressing force of the spring 16, and the cassette half 8 continues to move to a position where the detecting hole 8a can be detected. Thereby, the accuracy and the reliability can be improved, and also, the space can be saved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a detection switch for detecting a detection hole for preventing accidental erasure or a detection hole for determining the type of cassette provided in a cassette half of, for example, a VTR.

[Conventional technology]

As a cassette half detection switch for detecting a detection hole for preventing accidental erasure or a detection hole for determining the type of cassette provided in a cassette half of a VTR, for example, the configuration shown in FIGS. 3 and 4 is known. .

In the figure, 1 is a detection switch main body.

Reference numeral 7 denotes a substrate on which the detection switch main body 1 is fixed. 8
8a is a detection hole provided in the cassette half 8 for preventing accidental erasure or for determining the type of cassette; 8b normally covers the detection hole, and can be folded to prevent accidental erasure. It is a claw that is constructed so that it can be used.

4a and 4b are leaf switches having spring properties.

2c is a shaft provided on the detection switch main body l; 2 is a rotary knob that rotates around the shaft 2c; 2a is a knob that is inserted into the detection hole; 2b is a rotation of the rotary knob 2. By,
This is a protruding member that presses the leaf switch 4a.

Reference numeral 5 denotes a holding member that fixes the leaf switches 4a, 4b and restricts the curling of the leaf switches 4a, 4b.

Next, the operation of an example of the detection switch having the above configuration will be described.

In FIG. 4, the cassette half 8 moved from the direction of arrow A and inserted into the home position first contacts the knob 2a, and as the cassette half 8 further moves, the rotation knob 2 is rotated about the axis 2C. Rotated counterclockwise. By the rotation of the rotation knob 2, the protruding member 2b presses the leaf switch 4a, so that the leaf switches 4a and 4b come into electrical contact.

Thereafter, the cassette half 8 moves to the normal position, and the detection hole 8a and the knob 2b face each other, but since the claw 8b is not bent, the knob 2b is not inserted into the detection hole 8a. That is, since the rotation knob 2 is held in a state of being rotated counterclockwise, the leaf switch 4a and the leaf switch 4
The electrical contact of b is maintained, and a sensing circuit (not shown) detects the erasure enablement or the type of cassette.

Further, as shown in FIG. 3, when the claw 8b is bent, the cassette half 8 moves to the home position and the detection hole 8a
When the knob 2b faces the leaf switch 4a, the rotation knob 2 is rotated clockwise about the shaft 2c by the spring force of the leaf switch 4a, and the knob 2a is inserted into the detection hole 8a.

That is, since the rotary knob 2 is held in the same state as before the cassette half 8 was inserted, the leaf switch 4a and the leaf switch 4b are disconnected from electrical contact and erased by a detection circuit (not shown). Disabling or detecting the type of cassette.

Incidentally, in recent years, it has become desirable to be able to play back cassette halves of different sizes with a single playback device, for example in a VTR or the like.

Therefore, for example, when playing two types of cassettes, large and small, with one playback device, a detection switch is provided for each of the two types of cassettes to detect the detection hole for preventing accidental erasure or the detection hole for cassette type. There is a need.

In FIGS. 5(a) and (b) and FIG. 6(a) and (b),
An example of a conventional configuration is shown in which two detection switches detect detection holes of two types of cassette halves, large and small.

In these figures, 9 is the cassette half 8 mentioned above.
9a is a detection hole provided in the cassette half 9 for preventing accidental erasure or for determining the type of cassette; 610 has the same configuration as the detection switch main body l; 1 is a detection switch body that is located inside position 1 and detects a detection hole for preventing accidental erasure of the cassette half 9 or for determining the type of cassette; 11 is a base that fixes the detection switch body 10 and is movable; be.

As shown in FIGS. 5(a) and 5(b), when a large cassette half 8 is inserted, it is determined that it is the cassette half 8 by a means not shown, and the base 11 is lowered by a lifting means not shown, so that it can be detected. The switch body 10 is the base 1
1 and move in the direction of arrow B.

On the other hand, as shown in FIGS. 6(a) and 6(b), when a small cassette half 9 is inserted, a means not shown determines that it is a small cassette half 9, and an elevating means not shown moves the base 11 to the raised position. Therefore, the detection switch main body 1.0 does not move.

Therefore, when the cassette half 9 is installed at the predetermined mounting position, the knob 2a of the detection switch main body 10 is inserted into the detection hole 9a, so that the cassette half 9 can be prevented from being erased accidentally or The detection hole 9a of the cassette type is detected.

7 to 9 show another configuration in which the detection switch body 10 is moved to a position where it does not come into contact with the cassette half 8 when the cassette half 8 is inserted.

In the example of FIG. 7, when the large cassette half 8 is inserted, 1. The detection switch body 10 is moved from a position where the detection hole 9a of the cassette half 9 is detected to a position where it does not come into contact with the cassette half 8 in the direction of the arrow C or in the direction indicated by the arrow 2 by means not shown.

In FIG. 8, reference numeral 12 denotes a rotation axis for rotating the detection switch main body 10 within a vertical plane. In the example shown in the figure, when the cassette half 8 is inserted, the detection switch main body 10 is rotated by means not shown in the direction of the arrow E around the rotation shaft 12, and does not come into contact with the cassette half 8. moved to the position.

In FIG. 9, reference numeral 13 indicates a rotation fulcrum for rotating the detection switch body [O] in a horizontal plane. In the example shown in FIG. 9, when the cassette half 8 is inserted, the detection switch
0 is rotated in the direction of arrow F about the rotation fulcrum 13 by means not shown, and moved to a position where it does not come into contact with the cassette half 8.

[Problem to be solved by the invention]

As described above, the conventional detection switch for detecting the detection hole for preventing accidental erasure or the detection hole for determining the type of cassette provided in the cassette half of a VTR etc. If the detection holes are detected by two detection switches each, each time a large cassette half is inserted.

Since the detection switch that detects the detection hole of the small cassette half is moved to a position where it does not come into contact with the large cassette half, it has the disadvantage of requiring a special moving mechanism to move the detection switch. .

Furthermore, since the detection switch itself moves, it has low accuracy and reliability, and has the drawback of requiring space for movement.

The present invention has been made in consideration of one or more points, and includes a detection switch having a two-piece structure of a movable part and a fixed part, and an elastic member interposed between the movable part and the fixed part,
When a large cassette half is inserted, only the movable part of the detection switch is moved against the pressing force of the elastic member, thereby eliminating the need for a special moving mechanism.
The purpose of the present invention is to provide a cassette half detection switch that has high accuracy and reliability, and can save space.

[Means to solve the problem]

The cassette half detection switch of the present invention is a cassette half detection switch for detecting a detection hole provided in the cassette half for preventing accidental erasure or for determining cassette type, and includes a knob inserted into the detection hole and a detection hole for detecting the type of the cassette. A switch that electrically turns on and off according to movement, a fixed part ε that holds the switch and is fixed to the base, a movable part that can slide against the fixed part, and a structure between the fixed part and the movable part. It is characterized by comprising an interposed elastic member.

[Effect]

In the cassette half detection switch configured as described above, an elastic member is interposed between the movable part and the fixed part.

When a large cassette half is inserted, only the movable portion of the cassette half detection switch is moved against the pressing force of the elastic member.

Therefore, a special moving mechanism is not required, and it is possible to realize a cassette half detection switch that is highly accurate and reliable and can save space.

〔Example〕

Hereinafter, one embodiment of the cassette half detection switch of the present invention will be described with reference to FIG. 1 and FIG.

In these figures, the same reference numerals are given to the same requirements as in FIGS. 3 to 9.

1 and 2, reference numeral 6 is a regulating member provided on the detection switch body 1 to regulate the position of the detection switch 1 with respect to the base 7, and 7a is a regulating member that engages with the regulating member 6 to This is a fixing member that fixes 1.

Reference numeral 14 denotes a detection switch body that detects the detection hole 9a provided in the cassette half 9. 17 is.

The fixed part 15, which includes the holding member 5 and is fixed to the substrate 7, is a movable part which includes the rotation knob 2 and the lever 3 and slides along the inner peripheral side wall of the fixed part 17. 16 is a spring that is interposed between the fixed part 17 and the movable part 15 and presses the movable part 15.

17a is a stepped portion provided on the fixed portion F, and 15a is an engaging portion provided on the movable portion 15. Stepped portion 17a and engaging portion 1
5a is configured to engage, the movable part 15 is prevented from being pulled out from the fixed part 17 by the pressing force of the spring. 9b is a claw provided on the cassette half 9 and has a similar configuration to the claw 8b on the cassette half 8, and 15b is the top of the tip of the movable portion 15.

In the above configuration, a case where a cassette half 9 having a smaller shape than the cassette half 8 is inserted will be described with reference to FIG. 1.

When the cassette half 9 is inserted from the direction of arrow A,
When the claw 9b is bent, the knob 2a is inserted into the detection hole 9a.

Therefore, leaf switch 4a and leaf switch 4b are
Since there is no electrical contact, a detection circuit (not shown) detects whether erasing is disabled or the type of cassette.

On the other hand, when the claw 9b is not bent, the knob 2a is pressed by the claw 9b, and the rotating knob 2 rotates counterclockwise about the shaft 2c. As a result, the protruding member 2b presses the lever 3, and the lever 3 rotates clockwise about the shaft 3a. As a result, the lever 3 presses the leaf switch 4a, and the leaf switches 4a and 4b come into contact. In this way, it is detected that the claw 9b is not broken.

Next, a case where a large cassette half 8 is inserted will be described with reference to FIG. 2.

As shown in the figure, when the cassette half 8 is inserted from the direction of the arrow A, the cassette half 8 first
b. As a result, the top portion 15b is pressed by the cassette half 8.

Therefore, the movable part 15 moves downward along the inner peripheral side wall of the fixed part 17 against the pressing force of the 'spring 16. The cassette half 8 continues to move until the detection hole 8a is detected by the detection switch main body (not shown). As a result, the detection switch body 1 can detect the presence or absence of the detection hole 8a.

〔Effect of the invention〕

As detailed above, according to the cassette nozzle detection switch of the present invention, the detection switch has a two-piece structure including a movable part and a fixed part, and an elastic member is interposed between the movable part and the fixed part. When a large cassette half is inserted, only the movable part of the detection switch is moved against the pressing force of the elastic member, so there is no need for a special movement mechanism, and accuracy and reliability are improved. It has advantages such as high cost and space saving.

[Brief explanation of drawings]

Fig. 1 is a side sectional view showing the configuration of an embodiment of the cassette half detection switch of the present invention when a small cassette half is attached, and Fig. 2 is a cassette half of the present invention when a large cassette half is attached. FIG. 3 is a side sectional view showing the operation of an embodiment of the detection switch; FIG. The figure is a side sectional view showing an example of the operation of a conventional cassette half detection switch when a cassette half with an unbroken tab is installed, and FIG. A side view showing the operation of an example of a cassette half detection switch, FIG. 5(b) is a front view of FIG. 5(a), and FIG. 6(a)
6 is a side view showing an example of the operation of a conventional cassette half detection switch when a small cassette half is attached, FIG. 6(b) is a front view of FIG. 6(a), and FIGS. 7 to 9 are , a top view, a side view, and a top view showing an example of the operation of another conventional cassette half detection switch when large and small cassettes are attached. 8.9...Cassette half, 9a, 9b...Detection hole, 2...Rotation knob, 3...Lever, 4a, 4b
... Leaf switch, 5... Holding member, 6... Regulation member, 7... Board, 14... Detection switch body,
]-]...Movable part, 16...Spring, 17...
·Fixed part.

Claims (1)

[Scope of Claims] A cassette half detection switch for detecting a detection hole provided in a cassette half for preventing accidental erasure or for determining cassette type, comprising: a knob inserted into the detection hole; and movement of the knob. a switch that is electrically turned on and off according to the switch; a fixed part that holds the switch and is fixed to a base; a movable part that is slidable with respect to the fixed part; the fixed part and the movable part. and an elastic member interposed between the cassette half detection switch.