JPS60113349A - Tape terminal detecting device of tape recorder - Google Patents

Abstract

PURPOSE:To prevent malfunction surely by designing an operating section not to operate unless a reel shaft of tape taking up side stops, and unless the tape is wound to the terminal. CONSTITUTION:Rotation detecting members b1, b2 are provided for each of a pair of reel shafts a1, a2 that become tape taking-up side and tape supply side alternately. Rotation force of each reel shaft a1, a2 are transmitted to these members b1, b2 through friction mechanisms c1, c2 and energizing force of each rotation detecting member b1, b2 is transmitted to a common operating section (d). A detected member locking mechanism (e) of supply side is coupled to the rotation detecting member of tape supply side b2 and coupling between the rotation detecting member of tape supply side b2 is cut off. It is so designed that when energizing force transmitted from the rotation detecting member of tape taking-up side b1 to the operating section is eliminated, the operating section (d) starts operation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a tape end detection device for a tape recorder that operates an actuating section when a reel shaft on the tape winding side stops.

[Technical background of the invention and its problems]

In a so-called reverse tape recorder, a pair of reel shafts are used alternately as the tape winding side and the tape supply side, and playback or recording can be performed when the tape runs in either direction. In order to operate a switching mechanism that switches the running direction of the tape when the tape is wound, or to operate an automatic stop mechanism, it is first necessary to detect that the tape has been wound to the end. One way to do this is to detect the rotation of one reel shaft,
When the reel shaft stops, operating parts such as a switching mechanism and an automatic stop mechanism are operated assuming that the tape has been wound to the end.

However, according to this method, each time the tape running direction is switched, the reel shaft on the rotation detection side becomes the tape winding side or the tape supply side.

If the tape becomes slack while the reel shaft on the rotation detection side is on the tape supply side, or if something occurs that causes the reel shaft on the tape supply side to temporarily stop, There is a drawback that malfunctions occur, such as the actuating section operating even though the tape has not been wound to the end.

Since such a malfunction occurs when the reel shaft on the rotation detection side becomes the tape supply side, it should be possible to always detect the rotation of the reel shaft on the tape winding side. This is because the reel shaft on the tape winding side is driven by the drive source, so it is unlikely that the reel shaft will stop due to tape slack or the like. However, no tape end detection device based on this concept has been successfully put into practical use.

For example, the device described in Japanese Unexamined Patent Publication No. 58-139347 is also considered to be a good example of failure. To give an overview of FIG. A detection cam 22 is provided coaxially with one reel stand 25 side, and this detection cam 22 and a cam 46 on the other reel stand 43 side are connected by a connecting rod 30. . Further, two guide grooves 28 and 29 in the center direction are provided at one end of the detection cam 22, and a locking protrusion 27 is provided between them. A detection pin 63 protruding from the detection arm 62 is inserted into the guide groove 28 or 29, and the detection arm 62 repeats reciprocating motion parallel to the guide groove 28, 29. Therefore, when one reel stand 25 is on the tape winding side, the cam 35 is biased in the rotational direction of this reel stand 25 and presses the detection cam 22 in the same direction, and the detection pin 63 is placed in one of the guide grooves. It reciprocates while sliding in contact with the inner edge of 28. When the other reel stand 43 is on the tape winding side, the cam 46 is urged in the rotational direction of this reel stand 43, presses the detection cam 22 in the same direction via the connecting rod 30, and the detection pin 63 It reciprocates while slidingly contacting the inner edge of the other guide groove 29. When the detection cam 22 is pressed in any direction, the locking protrusion 27 comes to escape from the detection pin 63, but when the tape is wound up to the end, the reel stand 25°43 is Since the detection cam 22 stops and the pressing force against the detection cam 22 disappears, the detection pin 63 comes into contact with the top end of the locking protrusion 27 . As a result, the detection arm 62 rotates about the detection pin 63, actuating the interlocking mechanism 6, and as a result, the switching plate 7 moves to the right or left to switch the running direction of the tape.

However, the device described in the above publication has a serious defect.

For example, suppose that while one reel stand 25 is on the tape winding side, the other reel stand 43 is temporarily stopped due to slack in the tape or some other cause. When such a situation occurs, one cam 35 is urged by the contact resistance with the reel stand 25 and presses the detection cam 22, but the other cam 46 is urged by the contact resistance with the reel stand 43 and presses the detection cam 22. It acts to prohibit the rotation of 22. Then, the contact resistance between the cam 35 and the reel stand 25, and the cam 46
Since the contact resistance between the cam 35 and the reel stand 43 should be of the same magnitude, in the end, one cam 35
The pressing force is offset by the resistance force of the other cam 46, and the detection pin 63 comes into contact with the top end of the locking protrusion 27, resulting in malfunction.

In other words, although the device described in the above-mentioned publication aims to prevent malfunctions even if the reel stand on the tape supply side stops for some reason, this purpose has not been achieved.

[Purpose of the invention]

Therefore, an object of the present invention is to prevent malfunctions even if the IJ-rule shaft on the tape supply side stops for some reason.
An object of the present invention is to provide a tape end detection device for a tape recorder.

[Summary of the invention]

The outline of the present invention is schematically shown in FIG. That is, a pair of reel shafts 8 alternately serve as tape winding side and tape supply side.
1. A rotation detecting member bl, b2 is provided for each a2, and each reel shaft 81 . The rotational force of a2 is transmitted via the friction mechanism C7, C2, and the biasing force of each rotation detection member bl, b2 is transmitted to the common actuating part d, and the rotation detection member (for example, bz) on the tape supply side is transmitted. The supply side detection member locking mechanism e is engaged to disconnect the rotation detection member b2 on the tape supply side and the actuation section d, and the rotation detection member b1 on the tape winding side is transmitted to the operation section d. The actuating portion d is configured to operate when the applied force disappears.

Therefore, the operating portion d does not operate unless the reel shaft a1 on the tape winding side stops, that is, unless the tape is wound to the end, and malfunctions can be reliably prevented.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described based on the drawings from FIG. 3 onwards.

FIG. 3 is a schematic plan view of an auto-reverse tape recorder, and Io1 in the figure is the main board. A head mounting plate 102 is mounted on the main board 101 so as to be able to move forward and backward in the vertical direction in the figure, and a magnetic head 10 is mounted on the head mounting plate 102.
3 is installed. Also, there are 1 left and right on the main board XOZ.
A pair of capstan shafts 104, 204 and pinch rollers 105, 205 are provided. Each pinch roller 10
5, 205 is pivotally supported by a pinch arm 106206 rotatably supported on the main board 101.

In the figure, reference numerals 107 and 207 indicate a pair of reel shafts, and reel shaft gears 108 and 208 are provided coaxially with the reel shafts at the base of each reel shaft. In the figures, all gears are simply represented by circles (pitch circles) (this is the same in other figures as well, and the meshing points of the gears are marked with black dots).

Further, 709 in the figure is a motor that rotates the capstan shaft 1o4゜2o4 and the reel shafts 107, 207 in respective predetermined directions, and IIO in the figure holds the head mounting plate I02 in the forward position (operating position). It is a magnetic plunger.

A pinch roller switching plate III is rotatably supported at the front end of the head mounting plate 102 via a pivot shaft 111a, and a cam bin 112 is mounted on the upper surface of the front end of this switching plate lll0.
is installed protrudingly.

Further, a central portion of a bar spring 113 is locked to the pivot shaft 111a. Both ends of the bar spring 113 are connected to switching plates II.
Pinch arms 7 that are locked on the left and right ends of I and on the left and right front ends
06 and 206, respectively.

ZZ4 in the figure is a supply-side detection member locking plate mounted on the main board XOZ so as to be movable back and forth in the left-right direction in the figure. This locking plate 114 has a cam hole ZXS into which the cam pin 11z is inserted.

A long engagement hole s r 6'M is provided in the vertical direction in the figure. The front edge of the cam hole 115 is inclined toward the tip with the front edge pointing toward the center from the left and right, and the tip of the cam hole 115 is
This is a recess 115a into which the cam pin 112 is fitted.

In addition, reference numeral 117 in the figure denotes a switching plate rotatably provided on the right capstan shaft 204 as a fulcrum. is provided protrudingly, and a retaining hole 119 that is long in the radial direction is provided at the tip.

In the figure, 120.220 indicates each reel axis Z 07°207
Each rotating plate 12 is a rotating plate that can freely rotate around the center of the fulcrum.
Gears 12 r and 221 are pivotally supported at 0 and 220,
These gears 121 and 221 are connected to each reel shaft gear 10.
It is meshed with 8,208. Both rotation plates 120,2
20 has protrusions 122 and 222 in some parts, and a tension spring 123 is hung between them so that they are held in place by this spring 123.

In the figure, 124 is a switch that changes the polarity of the magnetic head Iθ3 according to the running direction of the tape.

Reference numeral 125 in the figure is a switching gear, and a locking pin 126 is provided on the upper surface of the gear 125 to be inserted into the locking hole 119, and two symmetrical tooth profiles are cut out to form a rest portion I25a.
, I25b.

A reverse drive gear 127 is coaxially provided below the switching gear I25.

FIG. 4 shows the rotation transmission path from the motor 109 to the left and right capstan shafts 104, 204 and the reel shaft gears 108, 208. This is a supported driven pulley.

In addition, 730 and 230 in the figure indicate each capstan shaft 104.2.
04 is a flywheel having a belt groove on its outer periphery, and 131 is a guide pulley pivotally supported on the X0XT surface of the main board.

A gear 132 is provided on the lower surface of the driven pulley xz9.
are integrally formed. In addition, 133°134.13 in the figure
5 is an integral gear, 136, 137° and 138 are other integral gears, and 139, 140 and 239, 240 are integral gears provided symmetrically. Furthermore, 141°, 142, and 143 in the figure are integral gears.

The motor pulley 128 and the driven booby II 129 rotate in conjunction with each other via the endless belt I44, and the motor pulley 1
2B, the left and right flywheels 130.degree. 230, and the guide pulley 131 rotate in conjunction with each other via a separate endless belt 14.5 to rotate both capstan shafts 704, 204 in opposite directions.

On the other hand, the driven pulley 129 rotates through the gears 132°, 133.
It is transmitted to the right reel shaft gear 208 via 134, 137, 136, 239° 240 and the gear 221. Further, the rotation of the gear 239 is transmitted to the left reel shaft gear 10B via the gears 139, 140 and the gear 121.

Furthermore, the rotation of gears 133 and 134 is caused by gears 135 and 14.
1,143 to the reverse drive gear 121.

Since the left and right reel shafts 707 and 207 have the same configuration, they will be explained together in one drawing (FIG. 5). - Note 1
The numbers in the 00s indicate the IJ'-all 107 side on the left, and the codes in the 200s indicate the reel shaft 207 side on the right.

A shaft Z 47 (247) is erected on the main board IOI via a bush 146 (24G).
(246) is a compression coil spring Z4 with a small elastic modulus.
g (248), a presser plate 149 (249), and a friction material xso (zso) made of felt or the like are fitted in order. Note that there are two suppressing protrusions 151a (252a) lI5Ib on the lower surface of the presser plate 149 (?49).
(251b) is provided protrudingly.

Further, the shaft 747 (247) is equipped with a rapid feed gear xs.
z (zst) is fitted. This rapid feed gear x s z (tst) has a sleeve part z s on the top side.
s (tss), and this sleeve portion 153
(353) is a compression coil spring 154 with a large elastic modulus.
(25G, the reel shaft gear 10B (20B) and a friction material zss (zss) made of felt, etc.
are fitted in sequence. Furthermore, the sleeve portion 153
The reel holder is plate 156 (256) on the outer periphery of (253).
, a cylindrical reel support r 57 (257) is firmly fitted. and reel support 157 (257
) is equipped with an engaging ring 159 (259) that can be raised and lowered freely and has an engaging portion 75B (25B) that engages in the rotational direction with a lever hub (not shown). 1
59 (259) and the reel holder is plate 156 (256)
There is a compression coil spring r t; 0 (2611) between
) is inserted. Note that the engagement ring 159 (25
9) The amount of upward movement is regulated by the reel support l524.

Here, the compression coil spring I48 (248).

Holding plate 14y (249), friction material 150 (250)
and rapid traverse gear r s z C! 52) J This constitutes a reverse friction mechanism l6I (26I), and also includes a compression coil spring xs4 (254), a reel shaft gear 10B (20B), and a friction material 155 (zs
s) and the reel receiver constitute a tape winding friction mechanism 162 (262) by the plate 156 (256).

Rotation detection members 163 and 263 are provided near each reel shaft 107 and 2Q7.

The rotation detecting members 163, 263 are as shown in FIG.
It is rotatably supported on the main board 101 using shafts 164, 264 as fulcrums, and a portion thereof is located on the lower surface side of the presser plates 149, 249. Further, the left rotation detection member I63 is provided with an abutting portion 165 at its tip on the same side as the presser plate 149 when viewed from the shaft 164, and one end of a pressing rod 166 is attached. In addition, the shaft 26 is attached to the right rotation detection member 263.
A guide portion 26 in which a contact portion 265 is provided on the opposite side of the presser plate 249 when viewed from 4, and through which the pressing rod 166 is inserted.
6 is provided. When the holding plates 146, 249 rotate clockwise, the pressing protrusion 151a of the left holding plate 149 presses the left rotation detection member 163 to rotate the detection member 163 to the right. side presser plate 24
The pressing protrusion 251b of No. 9 presses the contact portion 265 of the right rotation detection member 263 to rotate this detection member 263 to the right. Conversely, when the presser plates 149, 249 rotate counterclockwise, the suppressing protrusion 15 of the left presser plate 149
1b to press the left detection member 163 and press this member r63.
is rotated to the right, and the pressing protrusion 251a of the right holding plate 249 presses the contact portion 26 of the right detection member 263.
5 to rotate this member 263 to the right. In other words, when the presser plates 149, 249 rotate in any direction, a pressing force that rotates the rotation detection members 163, 263 to the right is generated. Here, it goes without saying that the rotational force of the presser plates 149, 249 is generated by the rotation of the reel shafts 107, 207.

On the other hand, on the front edge of the supply side detection member locking plate II4,
As shown in FIG. 6, left and right pressing pieces 1671168 and another pressing piece 169 close to the right pressing piece 16B are provided. When the locking plate 114 is moving to the left, the left suppressing piece 16'l prevents the abutment part r65 from moving to the right, and the locking plate 114 moves to the right. In this case, the right pressing piece 168 prohibits the abutting portion 265 from moving to the left.

A rotating pawl 170 as shown in FIGS. 6 and 7 is integrally formed on the lower surface of the switching gear 125. As shown in FIGS. This has a point-symmetrical shape with respect to the rotation axis, and has locking step portions 171a at two symmetrical locations.

17Ib. Further, a rotary cam 172 is integrally formed on the lower surface of the reverse drive gear 127. This has a spiral cam surface on the outer periphery, and a locking stepped portion 173 is formed between the maximum radius portion and the minimum radius portion.

Further, in FIGS. 6 and 7, reference numeral 174 denotes a swing plate made of synthetic resin, which has an opening 175 into which the rotating cam 172 is inserted, and the right side edge of this opening 175 is engaged. A joint part 176 is provided, and a pressing protrusion 177 is provided on the upper surface.
The rotation detection member 263 and the pressing rod 166
is placed to the right of the

Furthermore, two locking levers 178.1'19 are rotatably attached near the switching gear 125. One of the locking levers 178 has a locking claw at its tip engaged with one of the locking steps 171a and 171b on the outer periphery of the rotary claw 170 (FIG. 6 shows one of the locking steps 171a and 171b).
71a), in this report, the body part 125a+125 provided on the switching gear 125
Either one of b is opposed to the gear 142 (
(See Figures 3, 4, and 9).

Further, one of the locking levers 178 is provided with a pressure receiving piece 180 and an engaging protrusion 181, and the pressure receiving piece 180 is positioned in front of the pressing protrusion 777 of the swing plate 174. The other locking lever 179 has one end connected to one locking lever r.
It faces the outer periphery of the rotary claw 170 from the side opposite to 'is, and has an engaging protrusion 182 at the other end. A tension spring 183 is stretched between the locking levers 178, 179, and urges the levers 178, 179 in the direction of contacting the rotary claw 17°. In addition, 184 in FIG. 6 is a manual operation force transmission lever, and this lever 184 has two suppressing pieces 185.1.
116 is provided in a bifurcated shape, and one of the pressing pieces 185 is brought into contact with the engagement protrusion 182 of the locking lever 180 to hold the locking lever 180 at a position spaced apart from the rotary mold 170.

Therefore, the left rotation detection member I63 directly applies a pressing force to the swing plate 174 from the left via the pressing rod 166, and the bent right rotation detection member 263 directly applies a pressing force to the swing plate 174 from the left.

When the reel shafts 107, 207 are rotating, the rotation detection member (I63 or 263) on the tape winding side
A pressing force from the oscillating plate 174 acts on the swing plate 174, pressing the left edge of the opening 175 against the outer periphery of the rotary cam 172. Note that the rotation detection member (I63 or 263) on the tape supply side is prohibited from rotating in the right direction by the supply side detection member locking plate 114.
Or, the rotational force of 207) has no effect on the swing plate 174.

Also, the rotation detection member (I63 or 263) on the tape winding side
), the pressing force on the sliding plate 174 is generated by the transmission force of the reverse instep friction mechanism (I6I or 26I), but the reverse friction mechanism 16
Compression coil spring 148 used in 1.261,
248 have a small elastic modulus, the above-mentioned transmitted force is small, and therefore the pressing force acting on the swing plate 174 is also extremely small.

By the way, when the rocking plate 174 is receiving a pressing force from the left, the outer periphery of the rotating cam 1720)
75, and the swing plate 174 swings left and right accordingly to avoid engagement between the locking step portion 173 and the engaging portion 176. When the rotation stops and the pressing force acting on the rocking plate 174 disappears,
The swing plate 174 is held in a state shifted to the left by the maximum diameter portion of the rotary cam 172.

As a result, as shown in FIG.
3 engages with the engaging portion 176 of the rocking plate 174, and the rotating cam 1
12, the swing plate 174 moves in the direction of arrow A in the figure.
move in the direction. Therefore, the pressing protrusion 177 provided on the swing plate 174 presses the pressure receiving piece 180 of the locking lever 778, causing the locking lever 178 to rotate in the direction of arrow B in the figure. As a result, the locking lever 17B is connected to the locking step (r7xa or locking step l7Ib) of the switching gear 125.
) and release the locking track against the switching gear 125.

On the other hand, as shown in FIG. 9, the switching rotation plate 117
The switching movable piece 187 of the polarity switching switch 124 is formed by two elastic members rsga.

188b, and each time the switching gear 125 makes a half rotation, the switching movable piece 187 is moved by elastic members 188a and r.
88b.

The excessive amount of rotation of the rotation plate 117 is caused by the elastic member (188
a or l88b), and as a result, the restoring force of one of the elastic members (rgsa or xssb) is always applied to the switching gear 125 as a rotational force in the counterclockwise direction in the figure.

Therefore, when the locking lever 178 comes off the locking step (t'ixa or zyZb) of the rotary mold 170 as shown in FIG. It rotates slightly in the direction, meshes with the constantly rotating gear 142, and is driven to rotate.

Then, when the switching gear 125 rotates half a turn, the locking lever 1
7B engages with the locking step (I71a or ryrb) on the opposite side to stop the switching gear 125 again, but during this time, the switching rotation plate 117 is rotated due to the engagement between the engagement pin I26 and the engagement hole 119. It will operate in reverse. In addition, as the switching rotation plate 117 is reversed, at the same time as the switch 124 is switched, the supply side detection member locking plate 114 is moved to the left or right due to the engagement between the engagement hole 116 and the engagement pin 118. move towards

10 and 11 show the relationship between aNR of the supply side detection member locking plate 114 and peripheral mechanisms when the head mounting plate 102 is in the forward position (operating position). In this way, when the head mounting plate 102 is in the forward position, the cam pin 112 of the pinch roller switching plate XXX is moved to the recess 11 at the tip of the cam hole 115 provided in the locking plate 114.
5a.

In FIG. 10, the locking plate 114 is in the left position. At this time, the pressing piece 167 provided on the locking plate 114 presses the protrusion 122 of the left rotating plate 120 to the left, thereby separating the gear 121 from the gear 140. Further, as described above, the pressing piece 167 prevents the left rotation detection member 163 from rotating in the right direction (see FIG. 6), and the left rotation detection member 16
3 and the rocking plate 174 are disconnected. Furthermore, the pinch roller switching plate III is tilted to the left, so that the left pinch roller 105 is located at the left end of the rod spring 113.
is pulled away from the capstan shaft 104, and at the same time the bar spring 1
13, a right pinch roller 205 is pressed against the capstan shaft 204. Therefore, the rotational force of the motor 109 is transmitted to the right reel shaft 207, and the tape is transferred between the right capstan shaft 204 and the pinch roller 207.
5 and travels to the right in the figure, and is wound onto the right reel.

In contrast, in FIG. 11, the locking plate 114 is in the right position. Then, the pressing piece 169 provided on the locking plate 114 presses the protrusion 222 of the right rotation plate 22θ to the right, and the gear 22
1 is spaced apart from the gear 240. Further, as described above, the pressing piece 168 prohibits the rotation of the right rotating unloading member 263 to the right, and the relationship between the right rotation detecting member 263 and the swing plate 1'14 is severed. There is. Further, the pinch roller switching plate 211 tilts to the right, and the right end of the bar spring 113 separates the right pinch roller 2o5 from the capstan shaft 204, and the left end of the spring II3 moves the left pinch roller Iθ5 away from the capstan shaft. 104. Therefore, the rotational force of the motor 109 is transmitted to the left reel shaft rov, and the tape is held between the left capstan shaft 104 and the pinch roller 105, travels to the left in the figure, and is wound on the left reel. It will be taken.

12 to 14 show a mechanism for moving the head mount 102 from the retracted position (stop position) to the forward position (operating position).

A drive gear 189 is located near the gear 13B, and a drive gear 189 is located near the gear 13B.
It is attached to the back side of 01. This gear 189 has a resting part 190 by cutting out a part of the tooth profile, and has a spring receiving protrusion 191 on the top side and a spiral rotating cam 19 on the bottom side.
2 and a stop locking portion 193. Also gear 189
A stopper wall 194 is provided protruding from the peripheral edge of the lower surface.

Further, an operation locking portion 195 is provided protruding from a position near the stop locking portion 193 .

On the other hand, the movable iron core xx of the magnetic plunger 110
oa is always urged in the extension direction by a coil spring ll0b, and when the solenoid is energized by insertion of the cassette, it is drawn into the solenoid.

In addition, 196 in the figure is a locking lever, one end of this lever 196 is a cam retaining part 196a, and the other end is a plunger engaging part 1.
It is 96b. And the plunger retaining part 19
6b is the movable iron core 110a of the magnetic plunger 110
The cam engaging portion 196a engages with the tip of the rotating cam 192.
placed along the bottom surface of the Furthermore, 197 in the figure is a leaf spring (a rod spring is also acceptable), which is the spring receiving protrusion 1.
The free end is brought into pressure contact with 91 to apply rotational force to the drive gear 189 in the counterclockwise direction in the figure.

Further, reference numeral 198 in the figure is a cam lever, which is rotatably supported on the back surface of the main board 10, and has one end attached to the rotating cam 1.
It has a cam follower 198a that comes into sliding contact with the cam surface of 92. A rod spring 199 having a large elastic modulus is attached to this cam lever 198, and the tip of this rod spring 199 is engaged with a part of the head mounting plate 102.

Note that 200 in the figure is a tension spring for returning the head mounting plate IO2 from the operating position to the stop position, and the cam follower 198a is configured to be pressed against the cam surface of the rotary cam 192 by the elasticity of this tension spring 200. ing.

Therefore, when stopped, the locking lever 7 is
The cam engaging portion 196a of 96 engages with the stopping portion 193, and the resting portion 190 is opposed to the gear 13B. Further, the elastic force of the leaf spring 197 acts on the spring receiving protrusion 19T,
A rotational force is applied to the gear 189 in the counterclockwise direction in the figure. And the cam follower 198a is the rotating cam 19
2, and therefore the head mounting plate 10
2 is held in a retracted position (stop position) by a tension spring 200 (see FIG. 3).

When the tape cassette is inserted in this state, the solenoid of the magnetic plunger III becomes energized, the locking lever 196 rotates due to the operation of the movable core 110a, and the cam engaging portion 196a moves from the locking portion 793 when stopped. Then, as shown in FIG. 13, the drive gear 189 is slightly rotated by the leaf spring 197 and meshes with the gear 138.

Therefore, the rotation of the gear 13B, that is, the rotation of the motor 109, is now transmitted to the drive gear 189, and the drive gear 189 rotates approximately one rotation in the counterclockwise direction. During this time,
The cam follower 198 moves to the maximum radius of the rotary cam 192, and the cam lever 1'9B rotates greatly to move the head mounting plate XOZ against the tension spring 2004 to the movable position (FIG. 14). At this time, the cam engaging portion 19
6a engages with the engaging part 1954 during operation and drives the drive gear 189.
However, the rest portion 190 is again opposed to the gear XSS and is kept in pressure contact with the leaf spring 197 or the spring receiving protrusion 191 to apply a counterclockwise rotational force to the driving gear 189.

Also, when stopping, use the magnetic plunger 1.
10 may be stopped. At the same time as the energization is stopped, the movable core IIθa returns to the extension direction, the cam retaining portion 196a of the locking lever 196 is disengaged from the locking portion 195 during operation, and the drive gear 189 is rotated slightly by the leaf spring 197.
The cam follower 198a is located at the minimum radius portion i of the rotating cam 192.
Since the head panel 102 falls upward, the return spring 200
This allows the motor to return to the stopped position.

Incidentally, the rotating plates 120, 220 are rotated in conjunction with the backward movement of the head mounting plate 102, and the left and right gears 121, 2 are rotated.
21 from the gears 140, 240 (not shown)
is provided, and the rotational force transmission path from the motor 109 to both the reel shafts 107, 207 is cut off at the same time as the head mounting plate 102 returns.

The configuration of the above embodiment corresponds to the schematic diagram shown in FIG. 2 as follows.

That is, reel axis 107.20'! and rotation detection members 763 and 263, respectively, are reel axes al and a2 in FIG.
and rotation detection member bl.

Of course, the reverse friction mechanisms 167 and 261 correspond to the friction mechanisms CI and Cjl of the second rgJ, and the supply side detection member locking portion 11 corresponds to b2.
4 corresponds to the supply side detection member locking mechanism e in FIG. Also, the rocking plate I74° switching gear 125. The so-called auto-reverse mechanism includes the +1 perspective drive gear 127, the +L lever 'I78, and the supply side detection member plate 114.
This corresponds to the operating section shown in FIG.

In the above embodiment, the tape running direction can also be manually switched by moving the manual operation force transmission lever 184f shown in FIG. 8 to the left either directly or via some mechanism. That is, when the lever 184 is moved to the left, the left locking lever 129 first comes into contact with the peak of the rotary die 170, and then the pressing piece 186 moves the engagement protrusion 1111 of the locking lever 17B to the left. The locking lever 17B is released from the locking step (777a or 171b) of the rotary claw 170 by pressing the locking lever 17B, and thereafter the above-described operations are performed. The left locking lever 179 prevents the rotary die 172 from rotating more than half a turn even if the manual operating force continues to act for a long time, thereby preventing malfunctions such as continuous switching.

〔Effect of the invention〕

As described above based on the embodiments, according to the tape end detection device of the present invention, even if the reel shaft on the tape supply side stops for some reason, it will continue to operate as long as the reel shaft on the tape winding side does not stop. This does not have any influence on the parts, and it is possible to reliably prevent malfunctions from occurring.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing the prior art, Fig. 2 is a schematic diagram showing the outline of the present invention, Figs. 3 to 14 show an embodiment of the present invention, and Fig. 3 is a tape recorder. FIG. 4 is a plan view showing the rotation transmission path, FIG. 5 is a vertical sectional view of the reel shaft, FIG. 6 is a plan view showing the rotation detection member and its related mechanism, and FIG. 8 is a plan view of the area around the swing plate, and FIG. 9 is a plan view showing the switching gear and its related mechanism. FIGS. 10 and 11 are plan views showing the supply side detection member engagement plate and its related mechanisms, and FIGS. 12 to 14 are plan views showing the mechanism for driving the head mounting plate. 101.207... Reel shaft, 114... Supply side detection member locking plate, 125... Switching gear, 1270.・Reverse drive gear, 767, 261-0. Reverse friction mechanism, 163, 263... Rotation detection member, 174... Rocking plate. Applicant's agent Patent attorney Takehiko Suzue 171?7i'
i's! 'l'j';' (No change in content) Figure 1 Figure 2 Figure 3 Commissioner of the Patent Office Kazuo Wakasugi 1. Display of the case Relationship to the case of Japanese Patent Application No. 58-220289 Patent applicant Tanashin Electric Co., Ltd. 5, spontaneous amendment 6, specification subject to amendment, drawings

Claims (1)

[Claims] In a tape end detection device for a tape recorder that can perform playback or recording when the tape runs in either direction, with a pair of reel shafts alternately used as the tape take-up side and the tape supply side, each A pair of rotation detecting members that are biased in one direction by transmitting the rotational force of the reel shaft via the friction mechanism and transmit the biasing force to a common operating portion, and a pair of rotation detecting members that are engaged with the rotation transmitting member on the tape supply side. A supply-side detection member locking mechanism is provided that disconnects the rotation detection member from the operating section, and when the biasing force transmitted from the rotation detection member on the tape winding side to the operating section disappears, the operating section A tape end detection device for a tape recorder, characterized in that it operates.