JPH0516644Y2 - - Google Patents

Description

[Detailed Description of the Invention] The mode switching mechanism in the tape recording/reproducing apparatus of the present invention will be explained according to the following items.

A. Industrial field of application B. Overview of the invention C. Prior art c-1 General background c-2 An example of a mode switching mechanism in a conventional tape recorder [Figures 5 to 7] D. Problems to be solved by the invention [Figures 5 to 7] E Means for solving the problem F Example a Tape cassette [Figure 1] b Tape recorder [Figures 1 to 3] b-1 Outer casing, mechanical chassis, capstan , pinch roller [Figs. 1 to 3] b-2 Mode switching mechanism [Figs. 1 to 4]
] b-2-a Sliding base b-2-b Play lever b-2-c Lock lever b-2-d Reverse side sliding base control means b-2-e Charge spring b-2-f Link c Operation [Figs. 1 to 3] c-1 Formation of forward mode [Fig. 1,
Figure 2] c-2 Formation of reverse mode [Figures 2 and 3] c-3 Formation of stop mode from reverse mode The present invention relates to a mode switching mechanism in a playback device. Specifically, a first operating member to be used in the first mode and a second operating member to be used in the second mode, which are members involved in recording or reproducing on or from a tape, such as a magnetic head or a pinch roller. By moving one of the operating members to an operating position where it performs a predetermined action with respect to the tape, and placing the other operating member at a non-operating position, one of the first and second modes can be selected. This relates to a mode switching mechanism in a tape recorder or the like in which one of the modes is selectively formed, and the positional relationship required between two operating members when a mode is formed is determined between these two modes. By specifying the movement of two movable members that support each operating member separately, this type of mode switching mechanism can be configured with close to the minimum number of members necessary, and the mode switching mechanism can be The present invention aims to provide a mode switching mechanism for a new tape type recording/reproducing apparatus that can reduce the time required for switching to almost zero.

(B. Outline of the invention) The mode switching mechanism in the tape recording and reproducing apparatus of the present invention is a member involved in recording or reproducing on the tape, such as a magnetic head or a pinch roller, which performs the first operation to be used in the first mode. moving either one of the member and the second operating member to be used in the second mode to an operating position where it performs a predetermined action with respect to the tape, and the other member is moved to a non-operating position. In a mode switching mechanism in a tape recording/reproducing device, in which one of two modes, a first mode and a second mode, is selectively formed by positioning the device, the first operating member operates. holding means for holding the second operating member in the non-operating position when the second operating member is moved to the operating position; and charging means for charging the second operating member with a force for moving the second operating member to the operating position; a link means for returning the first operating member to the non-operating position by the movement of the first operating member when the mode is switched; The first operating member is moved to the operating position by the charging means, and the first operating member is returned to the non-operating position by the linking means, thereby minimizing this type of mode switching mechanism. It can be configured with a similar number of members, and the time required for mode switching can be reduced to almost zero.

(C Prior Art) (c-1 General Background) In a tape recording and reproducing device, for example, a tape recorder, recording and/or reading of recorded signals on a tape or reading of recorded signals recorded on a tape is performed. This is done while forming a predetermined track on the tape or by scanning the track by running the tape in a predetermined running direction with a magnetic head in contact with the tape. This is normally carried out by pinching between a rotating capstan and a pinch roller that is pressed against the rotating capstan so as to be able to come into contact with and separate from the capstan.

A tape recorder is usually provided with some kind of mode switching mechanism, and by operating one of a plurality of operating members such as a switch button or lever to create a predetermined mode, the operating member can be switched. A predetermined mode corresponding to
Recording mode, playback mode, tape fast forward mode,
One of various modes such as a tape rewind mode and a stop mode is selectively formed.

By the way, for example, some audio tape recorders (hereinafter referred to as "ATR") have a so-called reverse mode that allows recording and/or playback to be performed both when the tape is running in the forward direction and the reverse direction. Some ATRs are equipped with a play function, and some ATRs with this type of function have recently been equipped with so-called auto-reverse, that is, a state in which the tape end is detected while the tape is running in the forward direction. In some cases, the running direction of the tape is automatically switched to the reverse direction without interrupting the recording or reproducing operation.

(c-2 An example of a mode switching mechanism in a conventional tape recorder) [Figures 5 to 7] Figures 5 to 7 show an example a of a mode switching mechanism for performing auto-reverse in a conventional ATR. It is something.

b is a direction slider that is supported by a mechanical chassis (not shown) so as to be able to slide in the left-right direction, and is always biased by a tension spring c to move the slider to the left. Yes, the direction slider b
Two arms d ₁ and d ₂ project from the base, and pressing pins e ₁ and e ₂ are erected from the tips of the arms d ₁ and d ₂ .

f ₁ and f ₂ are flywheels located on the lower side of a mechanical chassis (not shown), and capstans g ₁ and g2 are separately erected from the centers of the flywheels f ₁ and f ₂ , and these flywheels
A part of an endless transmission belt i, which is driven by a motor h, is wound around f ₁ and f ₂ . The transmission belt i is wound so as to rotate the flywheels f ₁ and f ₂ in opposite directions, so that the transmission belt i is wound so as to rotate the flywheels f ₁ and f ₂ in opposite directions. g ₁ is rotated counterclockwise and is located on the left side for reverse
g ₂ is rotated clockwise.

j is a cam gear for moving the direction slider b, which is disposed below the direction slider b so as to be rotatably supported, and a cam k formed on the upper surface of the cam gear is a cam gear for moving the direction slider b. It is located in a substantially rectangular hole b' formed in b. The cam k is formed into a substantially oval shape, and is provided such that a position near one end surface in the longitudinal direction of the oval shape is coaxial with the rotation center of the cam gear j. When forming the forward mode, the cam k is positioned at a position where the other end surface in the longitudinal direction is located to the right of the rotation center of the cam gear j (hereinafter referred to as the "forward mode position"), as shown in FIG. ), and when forming the reverse mode, the orientation is 180° from the direction when the cam k is in the forward position, as shown in Figure 6.
The position in the opposite direction (hereinafter referred to as the "reverse position")
Say. ) and held in this position.

Incidentally, gear teeth are formed on the outer peripheral surface of the cam gear j, and notches l and l' are formed in parts of the outer peripheral surface located on opposite sides of the center of the cam gear j. Therefore, the gear teeth are missing at the notches l and l'.

Further, on the lower surface of the cam gear j, an elongated pressed protrusion m is formed at the center thereof, and protrusions n and n' are formed at positions 180° apart from each other on the outer peripheral edge thereof.

o is a drive gear fixed to the forward capstan _g1 , and the drive gear o is meshed with the cam gear j in a state where the outer circumferential portion of the cam gear j other than the notches l and l' faces the drive gear o. Therefore, when cam gear j is slightly rotated, for example, clockwise from the state shown in FIG. 5, cam gear j and drive gear o will mesh with each other.

P is a stopper whose main part is bent into a dogleg shape, and the bending point of the dogleg is rotatably supported by the mechanical chassis, and the stopper can be rotated counterclockwise in Fig. 7. Power is energized,
A pressed piece q is provided in a protruding manner. One end of the stopper p is attracted to the electromagnetic attraction means r, and the other end surface is positioned on the rotation locus of the protrusions n and n' formed on the lower surface of the cam gear j, and When the suction by r is released, the rotational force causes the rotational force to rotate to the position shown by the two-dot chain line in FIG.

s is a resilient member for applying a rotational force to the cam gear j in the clockwise direction in FIG. 5 (counterclockwise in FIG. 7) when the cam gear j comes to a predetermined position. That is, the rotation angle at which the cam gear j can be rotated by the drive gear o is a rotation angle smaller than 180°, but at the point when the rotation by the drive gear o is completed, that is, when the notch l of the cam gear j is connected to the drive gear o. , l' are opposed to each other, the pressed protrusion m of the cam gear j is applied with a rotational force in the clockwise direction by the resilient member s against the resilient member s. Immediately after the pressed protrusion m comes to such a position with respect to the resilient member s, the engagement between the cam gear j and the driving gear o is released, and the cam gear j returns to that state. After being slightly rotated clockwise by the pressing force of the resilient member s, the protrusion n or n' is rotated against the stopper p.
Its rotation is prevented by contacting the other end surface p'.

Therefore, the cam gear j has its protrusion n or n' in contact with the other end surface p' of the stopper p, and is biased by the rotational force in the clockwise direction by the resilient member s. , will be held in the forward or reverse position.

Further, when the cam gear j is in the forward position or the reverse position, for example, from the state shown in FIG. Since the stopper p is moved to the position shown by the chain line, the other end surface of the stopper p escapes from the rotation locus of the protrusions n and n' to the outside, thereby causing the cam gear j to move as shown in FIG. It will be rotated counterclockwise (clockwise in FIG. 5). As a result, the cam gear j is meshed with the drive gear o, so that the cam gear j is rotated by the drive gear o in the counterclockwise direction in FIG. 7 (clockwise in FIG. 5), and Since the protrusion n presses the pressed piece q of the stopper p and rotates the stopper p in the clockwise direction in FIG. 7, one end of the stopper p is attracted to the electromagnetic means r and the other end surface is again It will be located on the rotation locus of protrusions n and n'. Then, shortly before the cam gear j and the drive gear o disengage, the cam gear j is biased by the rotational force in the clockwise direction by the resilient member s as described above, and then the protrusions n and n' are The drive gear o comes into contact with the other end surface of the stopper p and comes off from the cam gear j, thereby bringing the cam gear j to the reverse position.

However, direction slider b is the fifth
It will be moved from the position shown in the figure (hereinafter this position will be referred to as the "forward position") to the position shown in FIG. 6 (hereinafter this position will be referred to as the "reverse position").

The proximal ends of t and t' are rotatably supported by the mechanical chassis, and the pinch rollers u, u' are rotatably supported at the rotating ends of the base ends, and rotation by tension springs v, v' is supported. This is a pinch roller arm that is provided under power. w,
w' is a limiter arm provided on the pinch roller arms t, t', and the limiter arms w,
The proximal end of w′ is formed in the shape of a torsion coil spring, and the distal end thereof is bent into a _{substantially} dogleg _shape . Press pin e ₁ erected from
e ₂ is being contacted from approximately the front.

The positional relationship between the limiter arms w and w' and the pins e ₁ and e ₂ of the direction slider b is such that when the direction slider b is in the forward position, the right pin e ₁ is connected to the right pinch roller. That is, the limiter arm w provided on the pinch roller arm t supporting the forward pinch roller u is held in a position where the pinch roller u is pressed against the forward capstan _g1 , and the right pin _e2 is placed on the left side. A limiter arm installed on the pinch roller arm t′ that supports the pinch roller U′ for reverse use.
When the pinch roller u′ is held in a position away from the reverse capstan g ₂ and the direction slider b is in the reverse position, the right pin e ₁ moves the limiter arm w to the forward position. The pinch roller u is held in a position separated from the forward capstan g ₁ , and the pin e ₂ on the left side holds the limiter arm w' in a position where the reverse pinch roller u' is pressed against the reverse capstan g ₂ . It's a positional relationship.

x is a tape cassette and y is a magnetic tape.

When the direction slider b is in the forward position, the magnetic tape y is held between the forward capstan _g1 and the pinch roller u, so the magnetic tape y is run in the forward direction, and , when the direction slider b is in the reverse position, the magnetic tape y
There is a reverse capstan G ₂ and a pinch roller
Since the magnetic tape y is sandwiched between the magnetic tapes y and u', the magnetic tape y is run in the reverse direction.

Note that z is a magnetic head for recording and reproducing, and the magnetic head z has two head chips located apart from each other in the same direction as the width direction of the magnetic tape y.
That is, a forward head chip and a reverse head chip are provided, and the circuit is switched so that the forward head chip works in the forward mode and the reverse head chip works in the reverse mode.

(Problems to be solved by the D invention) [Figures 5 to 7] As mentioned above, the conventional mode switching mechanism a moves the direction slider b to either the forward position or the reverse position. By moving the direction slider b, a predetermined tape running mode is established depending on the position. According to such a mode switching mechanism, a large number of members are required to move the direction slider b. This requires an extremely complicated structure, occupies a large space inside the tape recorder, increases cost, and has various problems such as mode switching takes time.

That is, the cam gear j is used as a means for holding and moving the direction slider b in a predetermined position, but in order to operate the cam gear j, other members, namely, A stopper p, a resilient member for applying rotational force to the stopper p, an electromagnetic means r, and a resilient member s for applying rotational force to the cam gear j at a predetermined timing.
Since it requires many control members, its structure is extremely complicated and also requires a considerable amount of space.

Therefore, this mode switching mechanism a causes an increase in the cost of the tape recorder, and also
This is also a factor that hinders miniaturization.

Furthermore, in order to switch the running direction of the magnetic tape y, the cam gear j needs to be rotated 180 degrees, so it takes time to switch the mode. Moreover, since the running of the tape is interrupted while the cam gear j is being rotated by that rotation angle, no recording or playback will take place during the interruption, and therefore no recording will be performed. If this is the case, the content that should be recorded at the above-mentioned time will not be recorded.

(E. Means for Solving the Problems) In order to solve the above-mentioned problems, the mode switching mechanism in the tape recording/reproducing apparatus of the present invention has a first operating member to be used in the forward mode and a reverse mode. a forward side sliding base and a reverse side sliding base each separately supporting a second operating member to be used in the process and moved between a playing position in which the operating member is brought into contact with the tape and a non-playing position in which the operating member is moved away from the tape; a moving base, a moving means for moving the forward side sliding base to a play position in response to a command for recording or reproduction, and a holding means for holding the reverse side sliding base at a non-play position in the forward mode. , a charging means for charging the reverse side sliding base with a moving force to the play position when the forward side sliding base is moved to the play position, and when the forward side running of the tape is stopped; a release means for releasing the hold on the reverse side sliding base by the holding means; and a forward side sliding by the movement when the reverse side sliding base is moved to the play position by the moving force charged to the charging means. A link means for returning the base to the non-playing position is provided.

Therefore, according to the present invention, the movement force of the reverse side sliding base to the play position is charged by the forward side sliding base being moved to the play position, and the holding by the holding means is released. The forward side sliding base is moved from the play position by the movement when the reverse side sliding base is moved to the play position. Since the mode is returned to the non-playing position, the mode can be switched from the forward mode to the reverse mode without using a drive means such as this, and the mode can be switched instantaneously. I can do it.

(F. Embodiment) Details of the mode switching mechanism in the tape recording/reproducing apparatus of the present invention will be described below in accordance with the embodiment shown in the accompanying drawings.

The embodiment shown in the drawings is a method of mode switching in an audio tape recorder that uses an ultra-small tape cassette called a microcassette or the like and is equipped with a forward magnetic head and a reverse magnetic head. This is applied to the mechanism.

(a Tape cassette) [FIG. 1] Before entering into the explanation of the tape recorder, an example of a tape cassette used in the tape recorder will first be explained.

1 is a tape cassette. 2 is a cassette case of the tape cassette 1, and its front side (the downward direction in FIG. 1 is referred to as the front side, and the upward direction is referred to as the rear side; the leftward direction in the figure is referred to as the left side; A relatively shallow recess (not shown) is formed in most of the area except for both left and right ends (the direction to the right is defined as the right side. In the following description, directions will be referred to in this direction). Tape exits are formed at both left and right ends.

3 and 3' are tape guides provided near the tape outlet.

Reference numeral 4 denotes a magnetic tape, and both ends of the magnetic tape 4 are fixed to two tape reels 5 and 5', respectively, and are wound by a predetermined amount. Then, the magnetic tape 4 is pulled out from one tape reel 5, that is, the so-called S reel, is wound around one tape guide 3, and is led out of the cassette case 2 from one tape outlet, and is placed on the front surface of the cassette case 2. After passing through the recess formed in the tape, the tape is introduced into the cassette case 2 from the other tape outlet, and
After being wound around the other tape guide 3', it is passed through a path where it is wound onto the other tape reel 5', that is, a so-called T-reel.

(b Tape recorder) [Figures 1 to 3] 6 is a tape recorder.

(b-1 Outer casing, mechanical chassis, capstan,
Pinch roller) [Figures 1 to 3] 7 is the outer casing 6 of the tape recorder (a part of it is shown cut away in the drawing), and 8 is a mechanical chassis (in the drawing, it is bent upwards). ), and 9 is the front end.

A capstan 10 is positioned such that its upper portion projects upward from the mechanical chassis 8. The capstan 10 is erected from a flywheel (not shown), and is rotated clockwise in a forward mode, that is, a mode in which recording or reproduction is performed on the magnetic tape 4 while the magnetic tape 4 is traveling in the forward direction. In a reverse mode, that is, in a mode in which recording or reproduction is performed on the magnetic tape 4 while the magnetic tape 4 is running in a reverse direction opposite to the forward direction, it is rotated counterclockwise.

The above-mentioned forward direction is the running direction in which the portion of the magnetic tape 4 that is led out of the cassette case 2 runs toward the left when the tape cassette 1 is mounted on the tape recorder 6. say.

Further, when the tape cassette 1 is attached to the tape recorder 6, the capstan 10 is relatively inserted into a hole (not shown) formed approximately at the center in the left-right direction of the front side of the cassette case 2, and thereby As shown in FIG. 1, the magnetic tape 4 is located inside the portion of the magnetic tape 4 that is led out of the cassette case 2.

11 is a pinch roller. The pinch roller 1
1 is rotatably supported by a pinch roller arm (not shown) that is movably supported with respect to the mechanical chassis 8, and when recording or reproducing, the capstan is rotated as shown in FIGS. 2 and 3. 10 to a position where the magnetic tape 4 is sandwiched and crimped (hereinafter referred to as the "crimping position"),
At other times, as shown in FIG. 1, it is held at a position where it does not come into contact with the magnetic tape 4.

(b-2 Mode switching mechanism) [Figures 1 to 4] 12 is a mode switching mechanism.

(b-2-a Sliding base) 13 and 14 are sliding bases, and of these two sliding bases 13 and 14, the one located on the right side is the forward side sliding base, and the one located on the left side 14 is a reverse side sliding base.

The forward side sliding base 13 is formed into a substantially rectangular plate shape that is long in the front-back direction when viewed as a whole, and has two elongated holes that are spaced apart from each other in the front-back direction and extend in the front-back direction. 15,1
5' is formed, and a magnetic head 16 (hereinafter referred to as "first magnetic head") for recording and reproducing used in forward mode is formed at the front end thereof.
is mounted with its head facing toward the rear.

The reverse side sliding base 14 is also formed in the shape of a substantially rectangular plate that is long in the front and back direction when viewed as a whole, and has a corner where its left edge and rear edge intersect with each other at a substantially right angle. Of the two notch edges of the notched portion, the approximately half portion 17 near the left end of the notch edge extending approximately in the left-right direction has an inclination that gradually displaces forward as it goes toward the left end. It is formed on the edge (hereinafter referred to as the "engaging edge"). In addition, the reverse side sliding base 14
are located spaced apart from each other in the front-back direction, and
Two elongated holes 18 and 18' are formed in the front and rear directions, and a magnetic head 19 for recording and reproducing (hereinafter referred to as "second magnetic head") used in reverse mode is provided at the front end of the holes. It is attached with its head surface facing rearward.

The forward side sliding base 13 and the reverse side sliding base 14 are spaced apart from each other in the left-right direction and are positioned parallel to each other and facing each other. The guide pins 20 and 20', 21 and 21' protruding from the mechanical chassis 8 are individually and slidably engaged, so that the mechanical chassis 8 can move freely in the front and back direction within a certain range. is supported by

Note that among the two elongated holes 15, 15' formed in the forward side sliding base 13 and the two elongated holes 18, 18' formed in the reverse side sliding base 14, the ones located on the front side of each other are 15 and 18. , those 15' and 18' located on the rear side of each other are arranged so that the first magnetic head 16 and the second magnetic head 19 are aligned with each other in the left-right direction.
The guide pins 20 and 21, 20' and 21' are also arranged so as to be aligned with each other in the left-right direction.

Further, the lengths of the elongated holes 15, 15' and 18, 18' and the positions of the guide pins 20, 20' and 21, 21' relative to the mechanical chassis 8 are as follows. That is, as shown in FIG.
3, 14 are the long holes 15, 15' and 18, 1
The rear end edge of 8' is the guide pin 20, 20' and 21,
21' (hereinafter referred to as the "non-play position"), the magnetic heads 16 and 19 are in contact with the tape recorder 6.
The tape cassette 1 mounted on the tape cassette case 2 is spaced a predetermined distance from the magnetic tape 4 passing through the front surface of the cassette case 2, and as shown in FIG. 2 or 3, the sliding bases 13 and 14 are Long hole 15,1
The front end edges of 5' and 18, 18' are the guide pins 20,
20' and 21, 21' (hereinafter referred to as
This position is called the "play position." ), the magnetic heads 16 and 19 are brought into contact with the magnetic tape 4.

Reference numerals 22 and 23 indicate engagement recesses formed on two opposing side edges of the two sliding bases 13 and 14;
3 and 14 are formed at portions that substantially face each other when both are in the non-play position.

Incidentally, the head surfaces of the two magnetic heads 16 and 19 are provided with positions shifted from each other in the height direction. That is, the head surface of one magnetic head is located at a height opposite to a portion of the magnetic tape 4 near one end in the width direction, and the head surface of the other magnetic head is located near the other end of the magnetic tape 4 in the width direction. It is located at a height opposite to the part of Therefore, the two magnetic heads 16 and 19 are spaced apart from each other in the width direction of the magnetic tape 4.
Each track will be scanned separately.

(b-2-b play bar) 24 is a play bar.

The play lever 24 is formed into a plate shape bent into a substantially inverted L shape, and has elongated holes 2 extending in the front-rear direction at both front and rear ends of a main piece 24a extending along the front-rear direction.
5, 25' are formed, and the main piece 24a
The locked piece 26 is
protrudes toward the right side, and a push button 27 is attached to its front end. Also. Spring hook pins 28 and 29 protrude from a position slightly to the left of the center portion of the rear piece 24b extending along the left-right direction of the play lever 24, and from a position close to the left end edge, A spring pin 30 is also provided protruding from the tip of the piece 26.

The play lever 24 has long holes 25 and 2.
The guide pins 31 and 31', which are provided upright from the mechanical chassis 8 at the mechanical chassis 8, are individually and slidably engaged with the mechanical chassis 8, so that the guide pins 31 and 31' can move freely in the front and rear directions within a certain range with respect to the mechanical chassis 8. The spring hanging pin 30 and the front end 9 of the mechanical chassis 8 are supported as shown in FIG.
A tension spring 32 is installed between the spring hanging piece 9a formed on the front panel 7a of the outer casing 7, so that a forward moving force is constantly applied to the push button 27. It is provided so as to be slidably positioned in the insertion hole 33.

Note that the play lever 24 has long holes 25, 25'.
The forward movement is prevented by the rear edge coming into contact with the guide pins 31, 31', and
When the push button 27 is in this position (hereinafter referred to as the "non-pushing position"),
is positioned so that most of it protrudes outward from the insertion hole 33 of the front panel 7a, and the rear piece 24
b is adapted to hold the two sliding bases 13 and 14 in the non-playing position by pressing them from the rear side.

(b-2-c Lock lever) 34 is a lock lever for holding the play lever 24 in that position when the play lever 24 is pushed in by a predetermined amount. The lock lever 3
4 is formed into a long plate shape in the front-rear direction, and a claw portion 35 bent toward the left at a substantially right angle is formed at the front end of the claw portion 35. It is formed on a slope 35a that gradually displaces rearward as it goes to the left end.

The rear end of the lock lever 34 is rotatably supported by a pin 36 erected from the mechanical chassis 8, and the other end of a tension spring 37, one end of which is supported by the mechanical chassis 8, is engaged. Therefore, the rotational force in the clockwise direction is applied, and when no pressing force is applied to rotate it in the counterclockwise direction, the side edge of the rotational force hits the stopper 38 provided on the mechanical chassis 8 side. By coming into contact with each other, the tip of the claw portion 35 is held at a position corresponding to the tip of the locked piece 26 of the play lever 24 in the front-rear direction.

Therefore, when the push button 27 is pressed from the state where the play lever 24 is in the non-depressed position, the play lever 24 is moved rearward and the locked piece 26 is locked by the beveled edge 35a of the claw portion 35 of the lock lever 34. Since the lock lever 34 is pressed from the front diagonally to the left, the lock lever 34 is rotated counterclockwise as shown by the two-dot chain line in FIG. Then, the play lever 24 is pushed into a predetermined position, that is, a position where the front edges of the elongated holes 25, 25' are close to the guide pins 31, 31' (hereinafter, this position is referred to as the "pushing position"). When it happens,
The piece 26 to be locked is the claw portion 3 of the lock lever 34.
5, the locking lever 34 is rotated clockwise by the tensile force of the tension spring 37, whereby the claw portion 35 is engaged with the tip of the locked piece 26 from the front side. .

However, the play lever 24 is locked
4, it is held in the pushed-in position.

(b-2-d Reverse side sliding base control means) 39 holds the reverse side sliding base 14 at the non-play position in the forward mode, and the mode is switched from the forward mode to the reverse mode. The control means 39 is a control means for releasing the above-mentioned holding state, and the control means 39 is composed of a rotating lever, an electromagnetic means, and the like.

40 is a rotating lever. The rotating lever 40 is formed into a substantially L shape, and the L-shape is approximately L-shaped.
The bending point of the letter is rotatably supported on the mechanical chassis 8 side, and the rear of one of the two arms 40a and 40b, which extends substantially in the front-rear direction in the state shown in FIG. An engagement pin 41 is erected from the end, and the other arm 4
A piece to be attracted 42 is supported at the left end of 0b so as to be rotatable within a small rotation angle.

The other end of a tension spring 43, which has one end attached to a spring hook 9b formed on the front end 9 of the mechanical chassis 8, is attached to a position near the left end of the other arm 40b of the rotating lever 40. , thereby applying a counterclockwise rotation force to the rotation lever 40.

Reference numeral 44 denotes an electromagnetic means, and when no current is supplied to the electromagnetic means 44, a magnetic attraction force is generated on its rear end surface, and when the current is supplied, the magnetic attraction force is released. It's becoming like that.

The rotary lever 40 is configured such that when the attracted piece 42 is attracted to the electromagnetic means 44,
As shown in FIG. 1, the engagement pin 41 is formed on the engagement edge 17 formed on the reverse side sliding base 14.
When the magnetic force of the electromagnetic means 44 is released from this state, the magnetic force of the electromagnetic means 44 is released. As shown, its engagement pin 4
1 is to the left of the left edge of the reverse side sliding base 14 (hereinafter, this position will be referred to as the "blocking release position")
Say. ).

Thus, the reverse side sliding base 14 is held at the non-play position when the rotary lever 40 is in the blocking position, and is moved to the play position by moving the rotary lever 40 to the blocking release position. Become able to move.

(b-2-e Charge Spring) 45 is a charge spring. The charge spring 45 is formed in the shape of a coil spring, and has a hook portion on one end of the charge spring 45 located on the left side of the two spring hook pins 28 and 29 provided on the rear piece 24b of the play lever 24.
The hook portion on the other end side is hooked to a spring hanging pin 46 that stands up from the rear end of the reverse side sliding base 14.

When the play lever 24 is pushed to the push-in position from the state in which the rotary lever 40 is in the blocking position, that is, the reverse side sliding base 14 is held in the non-play position, the charge spring 45 is extended, thereby increasing the tensile force of the charge spring 45, and this tensile force acts as a force for moving the reverse side sliding base 14 to the play position. That is, in this state, the reverse side sliding base 14 is charged with a force for moving toward the play position. Therefore, when the rotary lever 40 moves from this state to the blocking release position, the reverse side sliding base 14 is moved to the play position.

(b-2-f link) 47 moves the forward side sliding base 13 to the play position by moving the play lever 24 to the push position, and the reverse side sliding base 14 moves to the play position. This is a link for returning the forward side sliding base 13 to the non-playing position by being moved.

The link 47 is formed into a plate shape that is elongated in the left-right direction, and both left and right ends 47a and 47b are formed into a substantially circular shape, and a pin 4 is provided in the substantially central portion thereof.
8 is provided so as to protrude from the link 47 both upward and downward.

The left and right ends 47a and 47b of the link 47 are individually and slidably engaged with the engagement recesses 22 and 23 formed in the two sliding bases 13 and 14, respectively. The lower part of the pin 48 is slidably engaged with a longitudinally elongated hole 49 formed in the mechanical chassis 8, and one end of the upper part of the pin 48 is connected to the rear piece of the play lever 24. The other end of the tension spring 50 is engaged with the provided spring hook pin 29.

Therefore, the link 47 is biased with a rearward moving force by the tension spring 50 at its center, and when the two sliding bases 13 and 14 are both in the non-play position, the link 47 cannot slide. By arranging the engagement recesses 22 and 23 formed in the bases 13 and 14 so that they are aligned laterally with each other, they are arranged to extend substantially in the left-right direction.

(c. Operation) [FIGS. 1 to 3] Therefore, the formation of the forward mode and the formation of the reverse mode by the mode switching mechanism 12 configured as described above is performed as follows.

(c-1. Formation of forward mode) [Fig. 1,
[Fig. 2] The forward mode is normally used when the tape recorder 6
is in the stop mode as shown in FIG. It is formed by

That is, when the push button 27 is pushed in a predetermined amount from the stop mode, the play lever 24 is moved to the push-in position, and the lock lever 34 is moved to the push-in position.
By moving the play lever 24 to the push-in position, the charge spring 45 is extended, and the play lever 24
Since the rear piece 24b escapes rearward, the forward side sliding base 13 is in a state where it can move rearward.

Then, the link 47 is also in a state where it can be moved rearward, but in this state, the reverse side sliding base 14 is prevented from moving rearward, so the left end portion 47a of the link 47 is also prevented from moving rearward. ing. Therefore, the link 47 has its left end 47
a is rotated in the counterclockwise direction by the tensile force of the tension spring 50, with the rotation center being the portion that engages with the engagement recess 23 formed in the reverse side sliding base 14, and the right end portion 47b This pushes the rear end edge of the engagement recess 22 of the forward side sliding base 13 substantially rearward.

As a result, the forward side sliding base 13 is moved to the play position.

In addition, the forward side sliding base 13 is connected to the link 47.
The pin 48 is located in the elongated hole 4 formed in the mechanical chassis 8.
It comes to the play position just a little before it comes into contact with the rear edge of 9. That is, the front end edges of the elongated holes 15, 15' are brought into contact with the guide pins 20, 20', and are prevented from moving rearward therefrom. Therefore, the rotational force generated in the link 47 acts as a pressing force that constantly presses the forward-side sliding base 13 backward, thereby ensuring that the forward-side sliding base 13 is held at the play position. It turns out.

Thus, the first magnetic head 16 comes into contact with the magnetic tape 4.

When the forward-side sliding base 13 is moved to the play position, the magnetic tape 4 is run in the forward direction and wound onto the T-reel 5', and the first magnetic head 16 starts recording. Alternatively, regeneration will take place.

(c-2 Formation of reverse mode) [Figures 2 and 3] When the tape end state is reached from the forward mode, this state is detected by a predetermined detection means, and the A temporary current is supplied to the electromagnetic means 44 .

Then, the attraction of the rotating lever 40 by the electromagnetic means 44 is released, and the rotating lever 40 is moved to the blocking release position by the tensile force of the tension spring 43.

As a result, the reverse side sliding base 14 is moved all at once to the play position by the movement force to the play position that was previously charged by the charge spring 45.

Then, the left end portion 47a of the link 47 is moved rearward, and the pin 48 comes into contact with the front end edge of the long hole 49 formed in the mechanical chassis 8 immediately after the above-mentioned moving force starts. pin 48
is rotated clockwise using the position where it abuts on the elongated hole 49 as a rotation fulcrum.

Therefore, the right end 47b of the link 47 presses the front edge of the engagement recess 22 formed in the forward sliding base 13 substantially forward, so that the forward sliding base 13 is in the non-play position. It will be pushed back to approximately the same position.

Thus, the second magnetic head 19 comes into contact with the magnetic tape 4, and the reverse side sliding base 1
4 is moved to the play position, a predetermined signal is output, so that the magnetic tape 4 is run in the reverse direction and the second magnetic head 19
Recording or playback will be performed by.

(c-3 Formation of stop mode from reverse mode) When the tape end state is reached from reverse mode, or when a command to form stop mode is issued, the lock lever 34 moves as shown in the two-dot chain line in Fig. 1. As a result, the play lever 24 is returned to the non-pushing position, and the reverse side sliding base 14 is returned to the non-playing position, and the rotating lever 40 is moved by a moving member (not shown). and then returned to the blocking position.

This causes the tape recorder 6 to enter the stop mode shown in FIG.

(G. Effect of the invention) As is clear from the above description, the mode switching mechanism in the tape recording and reproducing apparatus of the present invention is a component that is involved in recording or reproducing on a tape, such as a magnetic head or a pinch roller. A first operating member to be used in the word mode, a second operating member to be used in the reverse mode, and a second operating member that is slidably supported on the chassis side and separately supports the two operating members. A forward-side sliding base and a reverse-side sliding base are moved between a play position where they are brought into contact with the tape and a non-play position where they are moved away from the tape, and a forward-side sliding base that is moved by a command to perform recording or playback. a moving means for moving the base to the play position; a holding means for holding the reverse side sliding base in a non-play position in forward mode; a charging means for charging the side sliding base with a force for moving it to the play position; a releasing means for releasing the hold on the reverse side sliding base by the holding means when the forward movement of the tape is stopped; The invention is characterized by comprising a link means that returns the forward side sliding base to the non-playing position by movement when the reverse side sliding base is moved to the playing position by a moving force charged in the means. .

Therefore, according to the present invention, the movement force of the reverse side sliding base to the play position is charged by the forward side sliding base being moved to the play position, and the holding by the holding means is released. The forward side sliding base is moved from the play position by the movement when the reverse side sliding base is moved to the play position. It will be returned to the non-playing position.

Therefore, according to the present invention, the mode can be switched from the forward mode to the reverse mode without using a drive means driven by a drive source such as a motor, and moreover, the mode can be switched from the forward mode to the reverse mode. The means necessary for the switching to take place are as follows:
Since only the holding means for the reverse side sliding base, the releasing means for releasing the holding by the holding means, the charging means, and the linking means are required, the mode switching mechanism can be configured with a number of members close to the minimum necessary. This allows the structure of this type of mode switching mechanism to be extremely simple.

Moreover, according to the present invention, the movement of the forward side sliding base from the play position to the non-play position and the movement of the reverse side sliding base from the non-play position to the play position are performed almost simultaneously. Switching can be done almost instantaneously. Therefore, there is almost no interruption time between the recording or reproducing operation in the forward mode and the recording or reproducing operation in the reverse mode.

In the above-described embodiment, the reverse side sliding base is held in the non-play position, and the electromagnetic means is used as a means for releasing the holding when the mode should be switched.
The holding means and releasing means in the present invention are not limited to such electromagnetic means, but may also utilize, for example, an operating member that detects the tape end or an operating member that is operated when the tape end is detected. good.

In addition, in the above embodiment, the operating member whose use is switched depending on the mode is a magnetic head, but the operating member in the present invention is not limited to the magnetic head, but also includes pinch rollers and other operating members whose use is switched depending on the mode. Therefore, any operating member may be used as long as its use is to be switched.

Further, in the above-mentioned embodiments, the present invention was applied to an audio tape recorder that uses an ultra-small tape cassette called a microcassette, but the present invention is not limited to such an example of application. The present invention can be applied to a mode switching mechanism in a tape recorder or other tape type recording and reproducing apparatus that performs recording and/or reproducing using a normal tape cassette called a so-called compact cassette.

[Brief explanation of the drawing]

Figures 1 to 4 show an example of an implementation in which the mode switching mechanism of the tape recording/reproducing apparatus of the present invention is applied to the mode switching mechanism of an audio tape recorder. FIG. 2 is a plan view showing the tape recorder in the forward mode with a part of the outer casing cut away; FIG. 3 is a plan view showing the tape recorder in the reverse mode with the outer casing cut away. FIG. 4 is a partially exploded perspective view of the mode switching mechanism, and FIGS. 5 to 7 show an example of the mode switching mechanism in a conventional tape recorder. Figure 5 is a plan view in forward mode.
FIG. 6 is a plan view of essential parts in reverse mode, and FIG. 7 is an enlarged bottom view of the cam gear control means. Explanation of symbols, 4... Tape, 6... Tape type recording/reproducing device, 8... Chassis, 12... Mode switching mechanism, 13... Forward side sliding base, 14
...Reverse side sliding base, 16... First operating member, 19... Second operating member, 24... Moving means, 40, 44... Holding means, 44... Release means, 45... Charge Means, 47, 50...Link means.

Claims (1)

[Claims for Utility Model Registration] A first operating member that is used in the forward mode and a second operating member that is used in the reverse mode, which is a member involved in recording or reproducing information on a tape, such as a magnetic head or a pinch roller. a working member that is slidably supported on the chassis side, supports each of the two working members separately, and is moved between a play position in which the working member is in contact with the tape and a non-play position in which it is separated from the tape. A forward side sliding base and a reverse side sliding base, a moving means for moving the forward side sliding base to a play position in response to a command for recording or reproducing, and a moving means for moving the forward side sliding base to a play position in the forward mode. holding means for holding the tape in a non-play position; charging means for charging the reverse side sliding base with a force for moving the tape to the play position when the forward side sliding base is moved to the play position; a release means for releasing the hold on the reverse side sliding base by the holding means when the traveling to the reverse side sliding base is stopped; and when the reverse side sliding base is moved to the play position by the moving force charged to the charging means. 1. A mode switching mechanism in a tape recording/reproducing apparatus, comprising link means for returning the forward side sliding base to a non-playing position by the movement of the forward side sliding base.