Cassette tape recorder with plural tape guide structure

A cassette tape recorder includes a combined head composed of a recording/playback head and an erase head, a first tape guide member positioned adjacent to the combined head and movable therewith for limiting transverse movement of a magnetic tape in a tape cassette while the magnetic tape is running, a second tape guide member positioned in spaced relation to the combined head so as to confront a substantially central portion of the tape cassette for limiting transverse movement of the magnetic tape while it is running, and a third tape guide member positioned in substantially symmetric relation to the first tape guide member with respect to the second tape guide member for limiting transverse movement of the magnetic tape while it is running, the arrangement being that the first, second and third tape guide members jointly guide the magnetic tape when the latter is fed along in recording and playback modes, and the first and third tape guide members jointly guide the magnetic tape when the latter is fed along at a higher speed. In another embodiment, a recording/playback head and an erase head are provided separately from each other, and the first and second tape guide members are positioned respectively adjacent to the recording/playback and erase head. The magnetic tape is guided by the first, second and third tape guide members at all times in various modes.

BACKGROUND OF THE INVENTION 
The present invention relates to a cassette tape recorder, and more 
particularly to a cassette tape recorder which uses a small-sized tape 
cassette known as a "microcassette". 
There are known cassette tape recorders using small-sized tape cassettes 
such as microcassettes. Such cassette tape recorders however are less 
advantageous than those cassette tape recorders employing normal compact 
tape cassettes in that when the magnetic tape runs at a high speed such as 
in a CUE/REV mode, the magnetic tape travels unstably, and cannot be wound 
neatly, with tape edges damaged. Thin magnetic tapes sometimes cannot be 
wound on a takeup reel. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a cassette tape 
recorder which will eliminate the above prior shortcomings, and is capable 
of feeding a magnetic tape stably and winding the same neatly when it is 
fed at high speeds. 
According to the present invention, there is provided a cassette tape 
recorder includes a combined head composed of a recording/playback head 
and an erase head, a first tape guide member positioned adjacent to the 
combined head and movable therewith for limiting transverse movement of a 
magnetic tape in a tape cassette while the magnetic tape is running, a 
second tape guide member positioned in spaced relation to the combined 
head so as to confront a substantially central portion of the tape 
cassette for limiting transverse movement of the magnetic tape while it is 
running, and a third tape guide member positioned in substantially 
symmetric relation to the first tape guide member with respect to the 
second tape guide member for limiting transverse movement of the magnetic 
tape while it is running, the arrangement being that the first, second and 
third tape guide members jointly guide the magnetic tape when the latter 
is fed along in recording and playback modes, and the first and third tape 
guide members jointly guide the magnetic tape when the latter is fed along 
at a higher speed. In another embodiment, a recording/playback head and an 
erase head are provided separately from each other, and the first and 
second tape guide members are positioned respectively adjacent to the 
recording/playback and erase head. The magnetic tape is guided by the 
first, second and third tape guide members at all times in various modes. 
The above and other objects, features and advantages of the present 
invention will become more apparent from the following description when 
taken in conjunction with the accompanying drawings in which preferred 
embodiments of the present invention are shown by way of illustrative 
example.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
As shown in FIGS. 1 and 2, a microcassette 1 has a pair of hubs 2, 2 
rotatably mounted therein and spaced from each other for winding a 
magnetic tape 3 therearound. The magnetic tape 3 as it is reeled off one 
of the hubs 2 is guided by a plurality of guide pins 4 and a guide roller 
5 toward a front face of the microcassette 1, and then wound onto the 
other hub 2. Although not shown, the front face of the microcassette 1 has 
a central head insertion slot, and a pair of laterally symmetrical head 
insertion slots. A pair of pads 6, 6 is disposed in the microcassette 1 in 
confronting relation to the lateral head insertion slots, respectively, 
the pads 6, 6 being resiliently supported on a leaf spring 7. 
When in a PLAY mode as shown in FIG. 1, the magnetic tape 3 is resiliently 
gripped between a capstan roller 8 and a pinch roller 9 in a cassette tape 
recorder, and travels in a desired direction in response to rotation of 
the rollers 8, 9. The cassette tape recorder includes a head base 10 
positioned in face-to-face relation to the front face of the microcassette 
1 and movable a prescribed distance toward and away from the microcassette 
1. The head base 10 has a combined head 12 having a recording/playback 
head and an erase head and a first tape guide plate 11 attached to one 
side thereof, a second tape guide plate 13, and a third tape guide plate 
14. When the microcassette 1 is placed in the cassette tape recorder, the 
first tape guide plate 11 and the combined head 12 are inserted into the 
lefthand lateral head insertion slot as viewed toward the front face of 
the microcassette 1, the second tape guide plate 13 is inserted into the 
central head insertion slot, and the third tape guide plate 14 is inserted 
into the righthand lateral head insertion slot. Therefore, the second tape 
guide plate 13 is positioned substantially in confronting relation to the 
center of the microcassette 1, while the first and third tape guide plates 
11, 14 are located in symmetric positions, respectively, with respect to 
the second tape guide plate 13. In a REC/PLAY mode, the magnetic tape 3 
travels sucessively past the third tape guide plate 14, the second tape 
guide plate 13, the combined head 12, and the first tape guide plate 11. 
As shown in FIGS. 3, 4 and 5, each of the tape guide plates 11, 13, 14 has 
a pair of upper and lower guide projections 15, 15 disposed transversely 
one on each side of the magnetic tape 3 and having rectilinear inner 
surfaces. The upper and lower guide projections 15, 15 jointly define a 
recess 16 therebetween. Thus, each tape guide plate has a channel shape. 
The upper and lower guide projections 15, 15 of the first tape guide plate 
11 are spaced from each other by a distance L1, the upper and lower guide 
projections 15, 15 of the second tape guide plate 13 are spaced from each 
other by a distance L2, and the upper and lower guide projections 15, 15 
of the third tape guide plate 14 are spaced from each other by a distance 
L3. These distances are selected to meet the dimensional relationship: 
L1.ltoreq.L2&lt;L3. 
FIG. 1 shows the position in the PLAY mode in which the head base 10 is 
located closely to the microcassette 1. The combined head 12 enters a 
prescribed distance into the microcassette 1 through the lefthand head 
insertion slot with the magnetic tape 3 being resiliently sandwiched 
between the pad 6 and the combined head 12. The magnetic tape 3 is also 
resiliently gripped between the capstan roller 8 and the pinch roller 9 
while running at a constant speed on rotation of the capstan roller 8 and 
the pinch roller 9. 
In FIGS. 3, 4 and 5, the tape guide plates 11, 13, 14 are in the solid-line 
positions when in the PLAY mode. The tape guide plates 11, 13, 14 are 
pushed into the microcassette 1 with the magnetic tape 3 inserted 
substantially centrally of the guide projections 15 of the first and third 
tape guide plates 11, 14. The magnetic tape 3 is located in confronting 
relation to the distal ends of the guide projections 15 of the second 
guide plate 13. During the PLAY mode, the magnetic tape 3 is guided 
successively by the third tape guide plate 14, the second tape guide plate 
13, and the first tape guide plate 11 in the order named. Therefore, the 
magnetic tape 3 is prevented from moving vertically by the three points, 
that is, the first, second, and third tape guide plates 11, 13, 14. The 
distance L3 between the guide projections 15, 15 of the third tape guide 
plate 14 is slightly larger than the distances L1, L2 between the guide 
projections 15, 15 of the other tape guide plates 11, 13. With such 
dimensions, the magnetic tape 3 as it runs is first roughtly guided 
vertically by the third tape guide plate 14, and then guided vertically by 
the second and first tape guide plates 13, 11 with successively greater 
positional accuracies. This enables the magnetic tape 3 to be positioned 
correctly with respect to the combined head 12 positioned adjacent to the 
first tape guide plate 11. Since the dimension L3 of the third tape guide 
plate 14 is slighly greater than the dimensions L1, L2, the third tape 
guide plate 14 can be attached with less positional accuracy than the 
other tape guide plates 11, 13. 
FIG. 2 shows the parts positioned in a CUE/REV mode. In this mode, the 
pinch roller 9 is spaced from the capstan roller 8 and the magnetic tape 3 
is wound at a high speed onto one of the hubs 2 which is driven to rotate. 
At this time, the head base 10 is retracted a prescribed distance with the 
combined head 12 remaining in slight contact with the magnetic tape 3. 
In FIGS. 3, 4 and 5, the tape guide plates 11, 13, 14 are located in the 
dotted-line positions when in the CUR/REV mode. The tape guide plates 11, 
13, 14 are retracted with the head base 10 so that the second tape guide 
plate 13 disengages from the magnetic tape 3 as illustrated in IFGS. 2 and 
4. While the first and third tape guide plates 11, 14 are retracted, the 
guide projections 15 thereof have their distal ends vertically confronting 
the magnetic tape 3. In the CUE/REV mode, therefore, the magnetic tape 3 
is not limited by the second tape guide plate 13, but limited vertically 
by the first and third tape guide plates 11, 14. 
FIGS. 6 through 10 show a cassette tape recorder according to another 
embodiment of the present invention. 
As illustrated in FIGS. 6 and 7, a microcassette 1 has a pair of hubs 2, 2 
rotatably mounted therein and spaced from each other for winding a 
magnetic tape 3 therearound. The magnetic tape 3 as it is reeled off one 
of the hubs 2 is guided by a plurality of guide pins 4 and a guide roller 
5 toward a front face of the microcassette 1, and then wound onto the 
other hub 2. Although not shown, the front face of the microcassette 1 has 
a central erase head insertion slot, and a pair of laterally symmetrical 
recording/playback head insertion slots. A pair of pads 6, 6 is disposed 
in the microcassette 1 in confronting relation to the lateral head 
insertion slots, respectively, the pads 6, 6 being resiliently supported 
on a leaf spring 7. 
When in a PLAY mode as shown in FIG. 6, the magnetic tape 3 is resiliently 
gripped between a capstan roller 8 and a pinch roller 9 in a cassette tape 
recorder, and travels in a desired direction in response to rotation of 
the rollers 8, 9. The cassette tape recorder includes a head base 10 
positioned in face-to-face relation to the front face of the microcassette 
1 and movable a prescribed distance toward and away from the microcassette 
1. 
The head base 10 has an erase head 18 having a second tape guide plate 17 
attached thereto, and a recording/playback head 20 with a first tape guide 
19 attached thereto, and a third tape guide plate 21. The third tape guide 
plate 21 is constituted of a raised end of an attachment plate 22 of the 
erase head 18. This arrangement reduces a number of parts required and the 
cost of manufacture. When the microcassette 1 is placed in the cassette 
tape recorder, the second tape guide plate 17 and the erase head 18 are 
inserted into the erase head insertion slot as viewed toward the front 
face of the microcassette 1, the first tape guide plate 19 and the 
recording/playback head 20 are inserted into the lefthand 
recording/playback head insertion slot, and the third tape guide plate 21 
is inserted into the righthand recording/playback head insertion slot. 
Therefore, the first and third tape guide plates 19, 21 are located in 
symmetric positions, respectively, with respect to the central second tape 
guide plate 17. 
As shown in FIGS. 8, 9 and 10, each of the tape guide plates 19, 17, 21 has 
a pair of upper and lower rectilinear guide projections 23, 23 overlying 
and underlying the magnetic tape 3. The upper and lower guide projections 
23, 23 jointly define a recess 24 therebetween. Thus, each tape guide 
plate has a channel shape. The upper and lower guide projections 23, 23 of 
the first tape guide plate 19 are spaced from each other by a tape guide 
width L1, the upper and lower guide projections 15, 15 of the second tape 
guide plate 17 are spaced from each other by a tape guide width L2, and 
the upper and lower guide projections 15, 15 of the third tape guide plate 
21 are spaced from each other by a tape guide width L3. These tape guide 
widths are selected to meet the dimensional relationship: L1.ltoreq.L2&lt;L3. 
FIG. 6 shows the position in the PLAY mode in which the head base 10 is 
located closely to the microcassette 1. The recording/playback head 12 
enters a prescribed distance into the microcassette 1 through the 
recording/playback head insertion slot with the magnetic tape 3 being 
resiliently sandwiched between the pad 6 and the recording/playback head 
20. The magnetic tape 3 is also resiliently gripped between the capstan 
roller 8 and the pinch roller 9 while running at a constant speed on 
rotation of the capstan roller 8 and the pinch roller 9. 
In FIGS. 8, 9 and 10, the tape guide plates 17, 19, 21 are in the 
solid-line positions when in the PLAY mode. The tape guide plates 17, 19, 
21 are pushed into the microcassette 1 with the magnetic tape 3 inserted 
substantially centrally of the guide projections 23. The magnetic tape 3 
as it is reeled off one of the hubs 2 by the coaction of the capstan 
roller 8 and the pinch roller 9 is guided successively by the third tape 
guide plate 21, the second tape guide plate 17, and the first tape guide 
plate 19 in the order named. Therefore, the magnetic tape 3 is prevented 
from moving vertically by the three points, that is, the first, second, 
and third tape guide plates 19, 17, 21. The tape guide width L3 between 
the guide projections 23, 23 of the third tape guide plate 21 is slightly 
larger than the tape guide widths L1, L2 between the guide projections 23, 
23 of the other tape guide plates 17, 19. With such dimensions, the 
magnetic tape 3 as it runs is first roughtly guided vertically by the 
third tape guide plate 21, and then guided vertically by the second and 
first tape guide plates 17, 19 with successively greater positional 
accuracies. This enables the magnetic tape 3 to be positioned correctly 
with respect to the erase head 18 and the recording/playback head 20. By 
making the dimension L3 of the third tape guide plate 14 slighly greater 
than the tape width, the third tape guide plate 21 can be attached with 
less positional accuracy than the other tape guide plates 17, 19. 
FIG. 7 shows the parts positioned in a CUE/REV mode. In this mode, the 
pinch roller 9 is spaced from the capstan roller 8 and the magnetic tape 3 
is wound at a high speed onto one of the hubs 2 which is driven to rotate. 
Since in the CUE mode the lefthand hub 2 is driven to rotate, the magnetic 
tape 3 is reeled out of the righthand hub 2, moves successively past the 
third tape guide plate 21, the second guide plate 17, and the first tape 
guide plate 19, and then is wound around the lefthand hub 2. In the REV 
mode, the righthand hub 2 is driven to rotate to reel the magnetic tape 8 
off the lefthand hub 2, feed the magnetic tape 3 past the first tape guide 
plate 19, the second tape guide plate 17, and the third tape guide plate 
21, and wind the magnetic tape 3 around the righthand hub 2. 
In FIGS. 8, 9 and 10, the tape guide plates 17, 19, 21 are located in the 
dotted-line positions when in the CUR/REV mode. The tape guide plates 17, 
19, 21 are retracted with the head base 10 so that the distal ends of 
their guide projections 23 limit vertical movement of the magnetic tape 3. 
In the CUE mode, the magnetic tape 3 moves successively past the third 
tape guide plate 21, the second tape guide plate 17, and the first tape 
guide plate 19. As in the PLAY mode, the magnetic tape 3 is first roughly 
guided in its vertical movement by the third tape guide plate 21 having 
the greater tape guide width. Therefore, the magnetic tape 3 can be guided 
smoothly without being subjected to undue stresses. 
In the REV mode, the magnetic tape 3 is reeled off the lefthand hub 2 and 
wound onto the righthand hub 2 at a high speed. Since the magnetic tape 3 
is held in contact with the erase head 18 at this time, the magnetic tape 
3 undergoes an irregular tension. Without the third tape guide plate 21 
downstream of the erase head 18 in the direction of travel of the magnetic 
tape 3, the magnetic tape 3 would be curled or wobble up and down due to 
the tension it suffers from, with the result that the magnetic tape would 
be folded or fail to be wounded neatly due to steps on the coil of the 
wound tape. The tension the magnetic tape 3 undergoes while running would 
cause the tape 3 to be curled in the vicinity of the second tape guide 
plate 17 upstream of the erase head 18, allowing the second tape guide 
plate 17 to damage the magnetic tape 3. 
In the foregoing embodiment, the recording/playback head and the erase head 
are disposed separately from each other. With such a cassette tape 
recorder, the erase head is insertable into a microcassette through a 
central head insertion slot defined in a front face of the microcassette, 
while the recording/playback head is insertable into the microcassette 
through a lefthand head insertion slot as viewed toward the front face of 
the microcassette. Since the recording/playback and erase heads have 
respective tape guide plates, the magnetic tape can more effectively be 
limited in its vertical movement than in cassette tape recorders having a 
combined head composed of a recording/playback head and an erase head with 
a tape guide plate attached. In the latter cassette tape recorder, the 
mere tape guide plate attached to the combined head is insufficient to 
limit the vertical movement of the magnetic tape. Therefore, another tape 
guide plate is necessary to suppress vertical movement of the magnetic 
tape. 
In the PLAY mode, the magnetic tape is required to run while it is held in 
a proper position with respect to the combined head. Therefore, it is 
necessary to provide a tape guide plate in confronting relation to a head 
insertion slot in the center of the front face of a microcassette. Such a 
tape guide plate is relatively close to the combined head for coaction 
with the tape guide plate attached to the combined head in guiding the 
magnetic tape properly with respect to the combined head. 
When the magnetic tape is fed along at a high speed as in the CUE/REV mode, 
the magnetic tape is kept in contact with the combined head and hence 
tends to suffer from irregular tension. This causes the magnetic tape to 
be twisted in the vicinity of the combined head upstream thereof. With the 
tape guide plate positioned in front of the center of the front face of 
the microcassette for guiding the magnetic tape while the latter is 
running at a high speed, the magnetic tape is liable to be curled and 
damaged by such tape guide plate. 
With the first embodiment of the present invention, the magnetic tape is 
guided by the first, second and third tape guide plates spaced 
substantially equal intervals so as to be prevented from being displaced 
vertically. Therefore, the magnetic tape can be maintained in a proper 
position with respect to the combined head in the REC/PLAY mode. When the 
magnetic tape is fed at a high speed as in the CUE/REV mode, the second 
tape guide plate is retracted out of engagement with the magnetic tape and 
does not damage the magnetic tape. Any tendency of the magnetic tape to 
move vertically due to disengagement from the second tape guide plate can 
be prevented by the third tape guide plate. Since the third tape guide 
plate is relatively remote from the combined head, the magnetic tape is 
not twisted in the vicinity of the third tape guide plate and hence is 
protected from being damaged thereby. The magnetic tape while travelling 
at a high speed can therefore be guided effectively and stably without the 
danger of getting damaged, and can neatly be wounded on a takeup hub. 
According to the second embodiment of the invention, the recording/playback 
and erase heads are separately disposed with the first and second tape 
guide plates are attached to the recording/playback and erase heads, 
respectively, and the third tape guide plate is positioned symmetrically 
relatively to the first tape guide plate with the second tape tuide plate 
located therebetween. The magnetic tape is guided by the first, second and 
third tape guide plates at all times in both the REC/PLAY mode and the 
CUE/REV mode. 
Although certain preferred embodiments have been shown and described, it 
should be understood that many changes and modifications may be made 
therein without departing from the scope of the appended claims.