JPH0610495Y2 - Cassette tape player - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] In this invention, a cassette case of magnetic tape is set on a take-up reel stand and a pay-out reel stand, and a constant speed rotation of a capstan causes the inside of the cassette case to be set. The present invention relates to a cassette tape player for playing back recorded information by feeding a magnetic tape at a constant speed.

[Prior Art] In this type of cassette tape player, the magnetic tape sometimes gets wrapped around the capstan during the reproduction of the recorded information on the magnetic tape. When the capstan is rotated for a long time while the magnetic tape is wound, the magnetic tape is tightly entangled around the capstan and the cassette case cannot be removed from the cassette tape player. Further, in this case, if the cassette case is forcibly taken out, the cassette tape player may be destroyed.

Conventionally, in order to solve such a problem, for example, a light transmission type optical sensor is provided in the vicinity of the capstan, a transmission path of the light is formed near the capstan, and the magnetic field around the capstan is wound around. Some tapes detect that the light transmission path is blocked by a tape and notify the user.

[Problems to be Solved by the Invention] In the case of the conventional cassette player described above, the fact that the magnetic tape has been wound around the capstan is merely notified. Therefore, it may take a long time until a measure such as stopping the cassette tape player is taken after notification that the magnetic tape has been wound, and the magnetic tape may be wound tightly.

Further, in the light transmission type optical sensor, the formation position of the transmission path is important, and depending on the variation of the formation position,
The detection timing of the winding of the magnetic tape may be delayed.

This invention solves such a problem, and an object of this invention is to provide the cassette tape player which detects the winding of the magnetic tape around a capstan quickly, and responds automatically optimally.

[Means for Solving the Problem] In the cassette tape player of the present invention, the cassette case of the magnetic tape is set on the take-up reel stand and the pay-out reel stand, and the capstan is rotated at a constant speed so that the cassette case in the cassette case In a cassette tape player that feeds magnetic tape at a constant speed to reproduce recorded information, the rotation speed detection unit that detects the rotation speed of the take-up reel base and the rotation speed detection unit When the speed increase of the take-up reel base is detected, it is determined that the magnetic tape has wrapped around the capstan and an eject signal is output, and an eject signal that causes the cassette case to be ejected based on the eject signal output by the control unit. And a mechanism.

[Operation] The cassette tape player of the present invention detects the rotation speed of the reel base on the winding side during reproduction of the magnetic tape, and reverses the rotation of the reel on the winding side, which should be gradually reduced if normal. When the speed is increased to 1, it is determined that the magnetic tape has wrapped around the capstan, and the cassette case is automatically ejected. This avoids the situation that the cassette case cannot be taken out.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

The present embodiment is a configuration example in which the rotation speed detecting unit 1 and the control unit 2 shown in FIG. 1 are incorporated in a general cassette tape player having an auto-reverse function and an automatic eject function.

Therefore, first, a general cassette tape player, which is the basic configuration of the present embodiment, will be briefly described.

In FIG. 2, a pair of left and right reel stands 4 and 5 are mounted on the base 3 of the cassette tape player, and the reels R1 and R2 of the cassette case C are set on these. In the left and right reel stands 4 and 5, the former is the take-up side and the latter is the take-up side when reproducing the A-side of the magnetic tape T, and the former is the take-up side and the latter is the take-out side when the B-side is reproduced. The base 3 is equipped with two left and right capstans 6 and 7, two left and right pinch rollers 8 and 9, and a magnetic head 10. The left and right capstans 6 and 7 are set with a cassette case C. It is located inside when it is touched (see FIG. 5).

Then, when reproducing the A surface of the magnetic tape T, as shown in FIG. 5, the magnetic head 10 is displaced in the direction of the arrow C ₁ so that the tip of the magnetic head 10 contacts the magnetic tape T in the cassette case C and the right side cap The stun 7 rotates at a constant speed in the direction of arrow A1, and the pinch roller 9 on the right side is displaced in the direction of arrow A2 about the axis O ₁ (see FIG. 6), and the pinch roller 9 is magnetized in the cassette case C. Press the tape T against the capstan 7. As a result, the magnetic tape T is unwound from the reel base 4 side on the left side, is fed at a constant speed in the direction of arrow A3, and is wound on the reel base 5 side on the right side, while the recorded sound on the A side is reproduced.

On the other hand, when reproducing the side B of the magnetic tape T, the magnetic head 10
Is displaced in the direction of arrow C ₁ , its tip comes into contact with the magnetic tape T in the cassette case C, the left capstan 6 rotates at a constant speed in the direction of arrow B 1, and the left pinch roller 8 moves along the axis O. Arrow B centered on ₂ (see FIG. 6)
Displaced in two directions, the pinch roller 8 presses the magnetic tape T against the capstan 6 in the cassette case C. As a result, the magnetic tape T is fed from the reel base 5 side on the right side, is fed at a constant speed in the direction of the arrow B3, and is wound on the reel base 4 side on the left side, while the recorded sound of the B side is reproduced.

Further, the cassette case C set on the reel stands 4 and 5 is automatically ejected by an eject mechanism operated by an eject solenoid (not shown) and the drive motor 11.

That is, when in the set position, as shown in FIG. 7, the cassette case C is lowered together with the cassette holder 12 while remaining inside the cassette holder 12, and the reels R1 and R2 in the cassette case C are moved to the reel base 4. , The upper part of 5 is in a fitted state.

In the eject operation, the eject solenoid is first excited to form a power transmission system between the drive motor 11 and the rack drive pinion 13 (see FIG. 6). Then, the drive motor 11 rotates in one direction, the rack driving pinion 13 rotates in the direction of the arrow D1 in FIG. 6, and the rack 14 and the eject lever 15 integrated with the rack 14 move in the rearward direction of the arrow D2. Slide to. As the eject lever 15 slides, the pin 16a (see FIG. 7) of the plate base 16 is displaced upward along the cassette holder vertical movement cam 15a of the eject lever 15, and the plate base 16 is rotated by the rotating shaft portion 16b.
Rotate in the direction of the upper arrow D3 (see FIG. 7). By the upward rotation of the plate base 16, the cassette holder 12 attached to the tip of the plate base 16 ascends horizontally with the cassette case C inside thereof, and the reels R1 and R2 of the cassette case C move from the reel bases 4 and 5. Removed upwards.

In addition, the eject lever 15 slides in the direction of the arrow D2 so that the first eject arm 17 moves to the pin 1
8 as a center in the direction of arrow D4 in FIG. 6, the tension spring 19 is pulled, and the second eject arm 2
0 is urged in the direction of the arrow D4. Then, when the cassette holder 12 is completely raised together with the cassette case C, the second eject arm 20 is rotated in the direction of the arrow D4 by the spring force of the tension spring 19, and the cassette pull-in slider 21 attached to the tip thereof. Slides along the sliding slit 16c of the plate base 16 in the front arrow D5 direction. Then, by sliding the slider 21 for pulling in the cassette, the cassette case C
Is pushed in the direction of arrow D6 in the front, and the ejecting operation ends.

When setting the cassette case C, by inserting the cassette case C into the cassette holder 12, the cassette pull-in slider 21 slides rearward, and the cassette holder 12 descends together with the cassette case C, The reels R1 and R2 in C fit on the upper portions of the reel stands 4 and 5.

In this embodiment, the rotational speed detecting unit 1 and the control unit 2 shown in FIG. 1 are incorporated into the cassette tape player having such a general structure.

The characteristic part will be described below.

The rotation speed detection unit 1 detects the rotation speed of the reel bases 4 and 5 on the winding side, that is, the rotation speed of the right reel base 5 during A-side reproduction and the left reel base 4 during B-side reproduction. In the case of the present embodiment, the rotation speed detection unit 1 is a light reflection type optical sensor 1a.
It is configured using. That is, the reel stand 4, 5
On the lower surface of the light reflection surface 1b and the light absorption surface 1c as shown in FIG.
4 are alternately formed along the circumferential direction, and light reflection type optical sensors 1a, 1a are provided at positions facing the lower surfaces of these reel stands 4, 5. These optical sensors 1
The a and 1a emit light toward the lower surfaces of the opposing reel stands 4 and 5, detect that the light is reflected by the light reflecting surface 1b, and output a pulse signal. Therefore, in these optical sensors 1a, 1a, the opposing reel stands 4, 5 are
Each time it rotates, four pulses are output, and the width of the pulse changes according to the rotation speed of the reel stands 4 and 5. The rotation speed detection unit 1 detects the rotation speed of the reel bases 4 and 5 from the pulse width.

On the other hand, the control unit 2 successively observes the change in the rotation speed of the reel base 4 or 5 on the winding side detected by the rotation speed detection unit 1, and the degree of the change is under a predetermined condition (this condition will be described later). ) Is satisfied, an eject signal is output. Therefore, the control unit 2 temporarily stores the detected speed V1 closest to the present time in the storage unit 2a, and the rotational speed determination unit 2b compares and determines the detected speed V1 and the latest detected speed V0 at the present time. Has become. In the case of the present embodiment, the control unit 2 determines that among the pulses output by the optical sensor 1a,
The pulse width closest to the present time and the latest pulse width at the present time are compared and determined.

The eject signal output from the rotation speed determination unit 2b is
This is a control signal for operating the eject solenoid of the eject mechanism and the drive motor 11 to automatically eject the cassette case C.

Next, the operation will be described.

During the normal reproduction operation of the A side or B side, the rotation speed of the reel base 4 or 5 on the winding side gradually decreases.
This is because the winding diameter of the magnetic tape T on the winding side reel R1 or R2 gradually increases. Therefore, at the initial stage of winding, the width T1 of the output pulse of the optical sensor 1a is small as shown in FIG. 4 (a), and at the latter stage of winding, the optical sensor 1a is shown as shown in FIG. 4 (b). The output pulse width T2 becomes larger. Specifically, when the diameter of the magnetic tape T on the take-up side at the beginning of winding of the magnetic tape T is 21.8 mm and the diameter at the end of winding is 50.4 mm, that reel is 0.7 times / second to 0.303 times / second. The width of the output pulse increases as the output pulse width gradually decreases.

Now, it is assumed that the magnetic tape T is wound around the capstan 6 or 7 for some reason while reproducing the side A or the side B. Then, the magnetic tape T is wound around the capstan 6 or 7, and the magnetic tape T is unreeled from both reels R1 and R2 at the same time. Moreover, the winding diameter of the magnetic tape T with respect to the capstan 6 or 7 is rapidly increased, and the feeding speed of the magnetic tape T from both reels R1 and R2 is rapidly increased. Therefore, the reel stand 4 or 5 on the take-up side is rotated in the reverse direction to feed out the magnetic tape T, and the rotation speed thereof is suddenly increased contrary to the normal reproduction operation. Therefore, the optical sensor 1
width of the output pulse of a is, as shown in FIG. 4 (c), winding suddenly changes from the time t ₀ generated becomes smaller as opposed to during normal playback operation.

The rotation speed determination unit 2b immediately outputs an eject signal and forcibly ejects the cassette case C on the condition that the pulse width has decreased. Therefore, the cassette case C is quickly ejected before the magnetic tape T is tightly wound around the capstans 6 and 7, and the situation in which the cassette case C cannot be taken out can be reliably avoided.

Specifically, when the diameter of the capstans 6 and 7 is 2 mm and the diameter of the through holes for the capstans 6 and 7 in the cassette case C is 4.6 mm, the winding diameter of the magnetic tape T around the capstans 6 and 7 is It is necessary to eject before reaching 4.6 mm. In the calculation, it is necessary to eject within 60 minutes tape within 4.75 seconds, within 90 minutes tape within 7.13 seconds after wrapping, and for 120 minutes tape within 9.5 seconds after wrapping. After all, it is enough to eject within 4 seconds after winding.

In the embodiment described above, the rotation speed detection unit 1 is
Although a reflection type optical sensor is adopted, it is not limited to this and various sensors can be adopted.

[Advantages of the Invention] As described above, the cassette tape player of the present invention detects the rotational speed of the reel stand on the winding side during reproduction of the magnetic tape, and if it is normal, the tape should be gradually decelerated. On the contrary, when the rotation of the reel on the take-up side accelerates,
Since the magnetic tape is determined to be wound around the capstan and the cassette case is automatically ejected, the following effects are obtained.

Whether or not the magnetic tape is wound around the capstan can be indirectly and reliably detected from the change in the rotation speed of the reel base on the winding side.

When detecting the winding of the magnetic tape, the cassette case is automatically ejected.Be sure to take out the cassette case before the strong winding of the magnetic tape and avoid the situation that the cassette case cannot be taken out. You can

[Brief description of drawings]

1 is a block diagram of an essential part, FIG. 2 is a schematic side view of a rotation speed detecting part, and FIG. 3 is a rear view of a reel stand. 4 (a), (b), and (c) are explanatory views of the output pulse of the rotation speed detecting portion, and FIG. 5 is a plan view of the main portion for explaining the relationship between the magnetic tape and the capstan. FIG. 6 is a schematic plan view for explaining the eject mechanism, FIG. 7 is a view on arrow VII of FIG. 6 when the cassette case is set, and FIG. 8 is a view similar to FIG. 7 when the cassette case is ejected. is there. 1 ... Rotation speed detection unit, 2 ... Control unit, 2a ... Memory unit, 2b ... Rotation speed determination unit, 6,7 ... Capstan, 8,9 ... Pinch roller, 10 ... Magnetic head, C: cassette case, T: magnetic tape.

Claims (1)

[Scope of utility model registration request] 1. A cassette case of magnetic tape is set on a take-up reel stand and a feeding reel stand, and the magnetic tape in the cassette case is fed at a constant speed by constant speed rotation of a capstan to reproduce recorded information. In a cassette tape player, when the magnetic tape is being fed at a constant speed, a rotation speed detection unit that detects the rotation speed of the take-up reel stand, and when the rotation speed detection unit detects an increase in speed of the take-up reel stand, It is characterized by comprising a control unit for outputting an eject signal when it is determined that the magnetic tape is wound around the capstan, and an eject mechanism for ejecting the cassette case based on the eject signal output by the control unit. Cassette tape player.