JPS6341621Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a reciprocating magnetic recording and reproducing device in which the tape end detection device corresponds to the tape running direction and is always switched to the take-up reel shaft side. Regarding the configuration of the reel shaft.

Generally, the tape end detection device is installed on one reel shaft, and in reciprocating magnetic recording/playback devices, the reel shaft can be either the take-up reel shaft or the supply reel shaft depending on the tape running direction, so it is Accordingly, the tape end detection device is also switched from the take-up reel shaft to the supply reel shaft. In the reciprocating magnetic recording and reproducing device configured in this way,
When the tape end detection device is switched to the supply reel shaft side, when the tape is fast-forwarded and then returned to the playback state, the tape may become slack due to the inertia of the supply reel shaft, which had been driven at high speed. As a result, the supply reel shaft is not rotated until the slack in the tape is eliminated. As a result, the rotation stop of the supply reel shaft is detected by the tape end detection device, and a malfunction occurs in which the tape running direction is reversed.

Therefore, as a method to solve this problem, the present applicant proposed in Utility Application No. 177016/1983 that the tape end detection device is always switched to the rewind reel axis side in connection with the reversal operation of the tape running direction, thereby preventing malfunctions. filed an application to prevent the To simplify this, the first
It is constructed as shown in the figure, and detecting plates 1 and 1', which are rotated in the rotational direction of the reel shaft constituting a conventionally well-known tape end detection device, are connected to the respective reel shafts 2 and 1'.
2', connects them, and connects the reel shaft 2,
2' as shown in the second and third figures, the play gear 3
The reel gear 4 is constantly driven by the clutch lever 5, and the reel spindle 7 is rotatably driven through friction materials 6, 6 such as felt by the upward pressure of the reel gear 4 by the clutch lever 5. It is composed of pressers 8, 9, and 9 that press and hold the mounted detection plate 1 from above and below, and furthermore, the clutch lever 5 is controlled by a switching plate 10 that can be switched between two positions depending on the tape running direction. Therefore, for example, when the switching plate 10 is in the position shown in FIG. 1 and the tape is being wound from one reel shaft 2' to the other reel shaft 2,
The clutch lever 5 of the reel shaft 2 is not actuated by the switching plate 10, but is energized by the spring 11 which energizes the clutch lever 5.
is pressed upward to drive the reel spindle 7, and the detection plate 1 is rotated in the same direction as the rotational direction of the reel spindle 7 by the pressers 8, 9, 9, but the clutch lever of one reel shaft 2' 5′
When the reel gear 4' makes contact with the switching plate 10 and is rotated counterclockwise against the bias of the spring 11', the reel gear 4' is released from pressure and moves downward as shown in FIG. As a result, rotation transmission to the reel spindle 7' is cut off. At this time, the upper presser 8' is moved downward under the force of the coil spring 12', but is stopped by the stepped portion 13' of the reel spindle 7', and the lower pressers 9' and 9' are also moved downwardly by the reel gear 4'. Since the detection plate 1' is lowered at the same time, the pressers 8', 9', 9' have no effect on the detection plate 1', and the detection plate 1' is independent of the rotation of the reel spindle 7'. Next, when the tape running direction is reversed, the switching plate 10 is switched to shut off the clutch mechanism of the reel shaft 2, and the clutch mechanism of the reel shaft 2' is operated, so that the detection plate 1' detects the end of the tape. perform an action. In this way, the tape end detection mechanism is switched to the take-up reel shaft side, and the above-mentioned problem is solved.

However, in such a configuration, a new problem has arisen in that the end of the tape cannot be detected during fast forwarding or rewinding. That is, during fast forwarding or rewinding, both reel shafts 2,
The clutch levers 5, 5' of 2' are operated simultaneously to cut off the play driving force via the friction materials 6, 6', and the idler gear 15 is crimped to the reel shaft 2 or 2' to perform fast forwarding or winding. By being configured to be in the rewind state, both detection plates 1 and 1' are independent of the rotation of the reel shafts 2 and 2', causing a malfunction in which the tape end detection device operates at the same time as the start of fast forwarding or rewinding operations. Was.

Therefore, the present invention was devised in view of this point.
The object of the present invention is to provide a reciprocating magnetic recording and reproducing device which eliminates the above-mentioned drawbacks with a simple configuration.

Examples of the present invention will be described below with reference to FIGS. 4 and 5. Components that are the same as those in FIGS. 1 to 3 are indicated by the same reference numbers, and improvements made by the present invention will be explained. The points improved by this proposal are that the upper presser 8,
A second spring 16, 16' having a weaker force than the first spring 12, 12' which presses down the pressing member 8' is provided between the presser element 8, 8' and the detection plate 1, 1'. Even if the clutch mechanism is interrupted during fast forwarding or rewinding, the detection plates 1, 1' are pressed against the reel spindles 7, 7' by the second springs 16, 16' and are rotated in the same direction as the reel spindles 7, 7'. In order to
Since the tape end detection device is activated only when the reel spindles 7, 7' are locked, the end of the tape can be reliably detected without malfunction even during fast forwarding or rewinding.

During regeneration, the spring 16' acts on the detection plate 1' on the reel shaft where the clutch mechanism is shut off, that is, the supply reel shaft 2', as described above. ' The pressing force with
Since the pressure force is weaker than that of the tape end, the detection plate 1 on the take-up reel shaft side performs the tape end detection function.

As mentioned above, the reciprocating magnetic recording and reproducing device of the present invention uses the first and second springs to press the detection plate of the tape end detection device, so that even if the clutch mechanism is cut off during fast forwarding or rewinding, the end of the tape can be detected. This prevents detection malfunctions and has a great practical effect.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing the main parts of the reciprocating magnetic recording and reproducing device of the present invention, Figs. 2 and 3 are diagrams showing the configuration of a conventional reel shaft, and Figs. 4 and 5 are diagrams showing the structure of the conventional reel shaft. It is a figure showing the composition of a reel shaft. 1, 1'...detection plate, 2, 2'...reel shaft,
4, 4'... Reel gear, 5, 5'... Clutch lever, 7, 7'... Reel spindle, 8,
8'... Upper presser, 9, 9'... Lower presser, 1
2, 12'...first spring, 16,16'...second spring.

Claims (1)

[Scope of utility model registration request] In a reciprocating magnetic recording/playback device in which the tape end detection device is configured to always switch to the take-up reel shaft side in accordance with the tape running direction, the reel gear is constantly driven and the reel gear is crimped by a clutch mechanism. a driven reel spindle;
A detection plate of a tape end detection device rotatably mounted on the reel spindle, an upper presser that presses the detection plate downward under the force of a first spring, and detection in conjunction with the vertical movement of the reel gear. a lower presser that presses the plate from below; a means for restricting downward movement of the upper presser when the clutch mechanism is shut off; and a second presser that presses the detection plate against the reel spindle.
A reciprocating magnetic recording and reproducing device characterized by being constructed with a spring.