JPH0235646A - Tape end detector - Google Patents

Abstract

PURPOSE:To detect the end of a tape without applying large pressure on the tape by holding a control member at a first eccentric position when the rotation of a reel shaft is stopped at the end of the tape, and moving the control member to a tape end detecting position by bringing a projection piece into contact with a second eccentric cam. CONSTITUTION:The device is constituted so that the control member 5 can always advance in one direction by always bringing a contact piece 8 into contact with a second rotating body 4. Simultaneously, it is constituted so that the control member 5 can be moved to the tape end detecting position by bringing the projection piece 6 into contact with the second eccentric cam 3 by holding the control member 5 at the eccentric position of a first eccentric cam 2 when the rotation of the reel shaft is stopped at the end of the tape. Also, the position regulation of the contact piece 8 is performed by providing a stopper 12 at the control member 5, thereby, assembling can be easily performed. In such a way, it is possible to detect the stoppage of a reel board without detecting the tension of the tape at the end of the tape.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a tape end detection device necessary for automatic stopping and automatic reversal of tape recorders and the like.

Conventional technology The generally widely known automatic stop mechanism for tape recorders is one that functions only at the end during recording and playback when trying to make a product with the simplest configuration and the most popular price. , the tape tension detection method as shown in FIG. 6 is the most common.

Briefly explaining this device, a tape 103 held and driven by a capstan 101 and a pinch roller 102 becomes tense when the end of the tape is reached, causing a detection piece 104 to rotate counterclockwise. This operation of the detection piece 104 causes the release lever 105 to rotate clockwise and move to a position where it can be engaged with the pawl 107 of the flywheel 106. fly foil 10
6 continues to rotate counterclockwise, and by moving the locking plate 108 to the left with the claw 107, the playback button 109 is returned to the stopped position.

Problems to be Solved by the Invention However, in the conventional device as described above, since the detection piece is pressed against the tape, longitudinal vibration is applied to the tape, leading to an increase in flutter components and an increase in modulation noise. . In addition, if the driving force of the capstan and pinch roller is low, sling occurs at the end of the tape and the desired operation cannot be obtained, so a large amount of pressure must be applied, making it difficult to reduce the power consumption of the device. .

In order to solve these problems, the present invention is an inexpensive method that detects the stoppage of the reel stand without detecting the tension of the tape at the end of the tape, has a simple configuration, and provides stable operation. The present invention aims to provide a tape end detection device.

Means for Solving the Problems To achieve the above object, the tape end detection device of the present invention includes a first rotating body that is linked to a drive source and has a first eccentric cam and a second eccentric cam; a second rotating body interlocked with a take-up reel shaft for driving a cassette tape; a control member having a protrusion that contacts the first eccentric cam and swinging in response to the cam; The contact piece includes a contact piece provided on the member and biased outward by a spring around its base end, and a stopper provided with a control member for regulating the tip end of the contact piece at a predetermined position. If the control member is always in contact with the second rotating body so as to always face in one direction, when the rotation of one reel stops at the end of the tape, the control member controls the eccentricity of the first eccentric cam. The control member is held in position K so that the protruding piece contacts the second eccentric cam and the control member moves to the tape end detection position.

Further, in the tape end detection device of the present invention, the contact piece is configured as a separate member from the control member, and the shaft provided at the base end of the contact piece is rotatable into two bearing holes provided in the control member. K, at least one of the bearing holes is formed into an elongated hole so that the rotation axis of the contact piece is substantially parallel to the axis of the second rotating body. Features.

Further, the tape end detection device of the present invention is configured such that the review operation member moved by the review operation is brought into contact with the control member via the elastic body, and the projecting piece of the control member is biased into contact with the first eccentric cam. In addition, during a play operation, the elastic body is moved by forward movement of the pinch roller lever, and the control member is configured to be swingable.

Effects The present invention has the following effects due to the above-described configuration.

In the tape end detection device according to the first aspect, since the control member is provided with a stopper to regulate the position of the contact piece, it is possible to perform an extremely easy assembly operation.

In the tape end detection device according to the second aspect, since one of the two bearing holes of the control member is an elongated hole, the rotation axis of the contact piece contacts the axis of the second rotating body substantially parallel to the axis of the second rotating body. and K. Therefore, there will never be unstable point contact,
It has a stable contact surface, reduces wear, and provides stable frictional force.

In the tape end detection device of claim 3, the control member is urged into contact with the first eccentric cam during review, and the control member is similarly brought into contact with the first eccentric cam in the stopped state. Therefore, it is possible to prevent malfunctions during review operations.

EXAMPLE Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1 is a plan view showing the main parts of an embodiment of the tape end detection device of the present invention, FIG. 2 is a top side view thereof, and FIG.
The figure is a bottom side view of the same. Furthermore, FIG. 4 is a plan view showing the playing state, and FIG. 5 is a sectional view showing the configuration of the reel stand. An example of this is a tape end detection device in a microcassette tape recorder. A first rotating body 1 that rotates in conjunction with a drive source such as a motor has a first eccentric cam 2 formed in an endless shape and a second eccentric cam 3 formed partially. . The first rotary body 1 is coaxially supported with a second rotary body 4 which is press-fitted integrally with a take-up reel shaft 22 for driving a cassette tape, and a felt 24 is pressed by a spring 23. It is rotatably attached to enable friction transmission through the . Reference numeral 5 denotes a control member, and a protruding piece 6 provided at one end is arranged at a position where it can come into contact with the first eccentric cam 2. This control member 5 is rotatably fitted into @7.

Further, the other end of the control member 6 is provided with two holes in the vertical direction.
One end of the contact piece 8 is rotatably attached to these two holes. The contact surface 9 near the other end of the contact piece 8 is pressed against the second rotating body 4, and the biasing force is due to the outward force of the contact piece spring 1Q suspended on the control member 5. There is. Furthermore, the tip 11 of the contact piece 8 can be regulated at a predetermined position by a stopper 12 provided on the control member 6. Here, this stopper 12
This is an effective structure for assembling the control member 5, the contact piece 8, and the contact spring 10 in advance, and also has the advantage of being easy to assemble at this location.

Next, to explain the case where the review operation member 13 is moved in the direction of the arrow, the scene lever 14 is interlocked and rotated clockwise, the pinch roller lever 16 is moved to the left, and the pressure spring 16 is held. The pressure contact lever 17 is configured to rotate counterclockwise. One end of the pressure contact spring 16 is provided at the center of the control member 6 and is arranged so as to be able to come into contact with the protrusion 718. Therefore, when the rift 18 is pushed by the pressure contact spring 16, the protruding piece 718 of the control member 6
is moved to the 6' position, and then the review operation member 1 is moved to the 6' position.
3 is pushed in and reaches the specified position, the pressure contact spring 1
e is bent and its biasing force is transmitted to the rib 18, and at the same time the projecting piece 6 is pressed against the first eccentric cam 2.

Next, to explain the actual operation, FIG. 1 shows a state in which the end of the tape is detected in the recording/playback state. In FIG. 1, the first rotating body 1 is rotating coaxially with the take-up reel axis, but it continues to rotate counterclockwise even after the end of the tape is reached, and until then the contact piece 8 and the second The control member 5 is biased clockwise by the frictional force caused by the pressure contact with the rotating body 4, and the projecting piece 6 is always in pressure contact with the first eccentric cam 2. However, when the end of the tape arrived, the second
Since the rotary body 4 stops rotating, the control member 5 is not biased clockwise and the protrusion 6 moves to the eccentric position of the first eccentric cam 2 (
(the position with the largest radius from the center). Next, the second eccentric cam 3 comes into contact with the protruding piece 6, and the entire control member 6 is largely rotated counterclockwise. This action causes the left end 19 of the control member 5 to move the bent portion 21 of the locking member 20 in the direction of the arrow, thereby returning the entire device to its stopped state.

Then, as a review operation, when the review operation member 13 is pushed in the direction of the arrow in the playback state, the pressure contact lever 17 is rotated together with the pinch roller lever 15 via the seesaw lever 14, and the control member 5 is also clockwise rotated via the pressure contact spring 16. direction, and the projecting piece 6 is pressed into contact with the first eccentric cam 2. In the review state, both the first rotating body 1 and the second rotating body 4 have their power source cut off along with the take-up reel shaft, are on the side where the tape is wound, and are rotating clockwise. . Therefore, when the review operation is suddenly finished and the playback is resumed, if there was no biasing force of the pressure contact spring 16, the protruding piece 6 would not be at the 6' position, but the contact piece 8 and the second rotary body 4 would be at the position 6'. In some cases, it may be moved to the position shown in the figure due to the frictional biasing force. At that time, the automatic stop will work against the operator's will. Therefore, the biasing force of the pressure contact spring 16 is set to be large enough to overcome the frictional biasing force between the contact piece 8 and the second rotating body 4 so that there is always no fear of such malfunction.

Effects of the Invention In the present invention, a stopper is provided on the control member to restrict the movement of the tip of the contact piece, so that assembly efficiency is improved and automatic assembly is also possible. In addition, since the contact piece is made as a separate member from the control member and supported in a centered manner in contact with the control member, the contact piece can obtain a stable contact surface with the second rotating body, and the allowable surface condition can be improved. It is possible to create a highly reliable device with a high degree of wear resistance and excellent wear resistance.

Furthermore, in order to prevent malfunctions even during review operations, the control member could be biased in the detection non-operation direction in conjunction with the busy review operation, so the first rotating body and the second rotating body could be placed on the same axis. A very simple configuration with a small number of parts is possible.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the main parts of an embodiment of the tape end detection device of the present invention, FIG. 2 is an upper sectional view of the same, FIG. 3 is a lower sectional view of the same, and FIG. 4 is a playing state. Plan, 6th
The figure is a sectional view showing the structure of a reel stand, and FIG. 6 is a plan view showing a conventional tape end detection device. 1...First rotating body, 2...First eccentric cam, 3...Second eccentric cam, 4...
-Second rotating body, 6...control member, 5a...
・Round hole, 6b...long hole, 6...protrusion,
8... Contact piece, 12... Stopper 1
3... Review operation member, 15... Name of pinch roller lever agent Patent attorney Shigetaka Awano and 1 other person r-
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Detective reka 4 Figure 2 c--Kazuhiro Agency 8-Mikoi Seri 12--Su L7 no 1゛- 1j=--Review clove jγ(Deki 1 15--(-Sotirola b bar 3rd Figure j$4 Figure n

Claims (3)

[Claims] (1) A first rotating body that is interlocked with a drive source and has a first eccentric cam and a second eccentric cam; a second rotating body that is interlocked with a take-up reel shaft for driving a cassette tape; a control member that has a protrusion that contacts the eccentric cam of No. 1 and swings in response to the cam; and a contact piece that has one end attached to the control member and is spring-biased outward about its base end. and a stopper provided on the control member to restrict the tip of the contact piece to a predetermined position, so that the contact piece is always in contact with the second rotating body and the control member is always directed in one direction. In addition, when the rotation of the reel shaft stops at the end of the tape, the control member is held at the first eccentric position, so that the projecting piece contacts the second eccentric cam and the control member A tape end detection device characterized in that it is configured to move to a tape end detection position. (2) In the tape end detection device according to claim 1, the contact piece is made of a separate member from the control member, and the shaft provided at the base end of the contact piece is connected to two bearing holes provided in the control member. The contact piece is movably supported, and at least one of the bearing holes is formed into an elongated hole so that the rotation axis of the contact piece is substantially parallel to the axis of the second rotating body. A tape end detection device characterized by: (3) The review operation member moved by the review operation is brought into contact with the control member via an elastic body, and the projecting piece of the control member is biased into contact with the first eccentric cam, and the play operation 2. The tape end detecting device according to claim 1, wherein said control member is configured to be swingable by moving said elastic body by forward movement of a pinch roller lever.