JPH0138746Y2 - - Google Patents

Description

[Detailed explanation of the idea]

The present invention relates to a tape end detection device for a recording/reproducing device, and particularly to a device for detecting the tape end of a cassette tape using a light emitting source and a light receiving section facing each other.
Provided is a tape end detection device for a recording/reproducing device configured to effectively reduce the size of a cassette by changing the height positions of a light emitting source and a light receiving portion and arranging them both at positions apart from a cassette mounting portion. The purpose is to The applicant previously developed a tape cassette that is smaller than a standard tape cassette, an adapter used to attach this small tape cassette to a standard type recording/playback device, and a tape cassette that is smaller than a standard tape cassette. We proposed a small, wearable recording and reproducing device. The present invention was developed specifically for the purpose of downsizing this tape cassette. The tape edge detection device of a standard type recording/reproducing device is configured such that the light emitting source and the light receiving section are arranged at the same height, and the optical axis is parallel to the chassis and perpendicular to the width direction of the tape. . Specifically, the light emitting source is provided to protrude into the cassette mounting part, the light receiving part is provided on the side of the cassette mounting part, and the light receiving part is relatively fitted into the cassette in which the light emitting source is mounted. For this reason,
In addition to the tape storage space, the cassette requires additional space for the light emitting source, and with the current structure, it is difficult to make the cassette sufficiently compact. The present invention solves the above-mentioned problems and makes it possible to effectively downsize the tape cassette.One embodiment of the invention will be described below with reference to the drawings. 1 and 2 show the states of a recording and/or reproducing apparatus 1 in a stop mode and a recording/reproducing mode, respectively, to which the tape end detection device according to the present invention is applied. This recording/reproducing apparatus 1 is provided with a guide drum 3, a cassette mounting part 4, a tape end detection means 5, etc., which are the essential parts of the present invention, on a chassis 2, and further includes a tape shown taken out in FIG. 3 on the upper and lower surfaces of the chassis. It has a general configuration including a loading mechanism 6 and the like. A small cassette 10 shown in FIG. 4 is attached to this recording/reproducing apparatus 1. As shown in FIG. This small cassette 10
As shown in the figure, the cassette casing 12 is made up of a cassette casing 12 containing a magnetic tape 11, and a lid 13 which is provided on the front side of the cassette casing 12 so as to be openable and closable and which is normally closed. As shown in FIG. 1, the cassette housing 12 includes a small-diameter supply reel 14 and a take-up reel 15.
are placed side by side. The supply reel 14 is exposed through an opening 16 at the bottom of the cassette housing 12. The outer periphery of this lower flange of the take-up reel 15 is the gear part 1.
7, and a portion of this gear portion 17 is exposed through a side window 18 of the cassette housing 12. This cassette housing 12 is not provided with an opening into which a light source for tape end detection is fitted, and therefore both reels 14,
15 are placed sufficiently close to each other so that the small cassette 1
0 is quite small. The magnetic tape 11 is attached to the guide poles 1 on the left and right ends.
The cassette housing 12 is guided by 9a and 19b.
A tape path 11A is formed along the front surface of the tape.
Furthermore, transparent tape portions (not shown) of a predetermined length are provided at both ends of the magnetic tape 11 to be detected by tape end detection means. Here, the tape loading mechanism 6 of the recording/reproducing apparatus 1 and related mechanisms are explained in FIGS. 5 to 1.
This will be explained with reference to FIG. The tape loading mechanism 6 includes timing gears 20, 2
1 rotates, the timing belt 22,
23 is running, loading poles 24, 25
is configured to move along the guide grooves 26, 27 of the chassis 2 from the position shown in FIG. 1 to the loading completion position shown in FIG. 2, and to load the tape into a predetermined tape path. The timing gears 20 and 21 are overlapped with a main gear 28 in the center, a cam disk 29 at the top, and an angle detection disk 30 at the bottom, so that the main gear 28 corresponds to the chassis 2, and the gears 20 and 21 correspond to the bottom of the chassis 2, respectively. It is rotatably fitted to the shaft 31 in a height relationship that faces the sides and the top. The cam disk 29 and the angle detection disk 30 are connected to the main gear 28 by a pin 32, and the timing gears 20 and 21 are connected to the pin 32 by coil springs 33 and 34. , timing gear 2
0 and 21 are rotated substantially integrally with the main gear 28, and are rotated approximately 360 degrees clockwise during loading and counterclockwise during unloading. The timing belt 22 is connected to the timing gear 20
and guide rollers 35 to 38, with one end directly connected to the loading pole support 39 and the other end connected to the same support 39 via a coil spring 40.
9 to form a closed loop along the lower surface side of the chassis 2. Another timing belt 23 includes a timing gear 21 and a guide roller 414.
3, and along the stop pole 44, one end is directly connected to the loading pole support 45, and the other end is connected to the same support 45 via a coil spring 46.
5 to form a closed loop along the upper surface side of the chassis 2. Support stands 39 and 45 are fitted into guide grooves 26 and 27, respectively, so as to be movable along them. A substantially spiral cam groove 47 is formed in the cam disc 29. This rotation of the cam disk 29 causes the audio control head 48 and the pinch roller 4 to
9 is moved in the latter half of the tape loading operation as will be described later. Before loading the tape, as shown in FIG. 1, the head 48 is in a position that is retracted from the guide groove 27 so as not to interfere with the tape loading operation, and the pinch roller 49 is separated from the cassette mounting section. Figure 6A shows the cam disc 29 before loading the tape, and Figure B shows the cam disc 29 after loading the tape.
Shows the rotation status of. FIG. 7 shows a cam diagram of the cam groove 47. As you can see from this, the cam groove 47
The inner circumferential circular portion 47a (I _a ) and the outer circumferential circular portion 47
b (I _b ) and the increasing radius portion 47c (I _c ) that connects the two.
and an increasing radius portion 47d extending from the outer circumferential circular portion.
(I _d ). In particular, as shown in FIGS. 8 and 9, the head 48 is mounted on the tip of a support arm 51 that is pivotally supported on a shaft 50. As shown in FIGS. The auxiliary arm 52 is pivotally supported by a pin 54 on the support arm 51, and has a pin 55 at its tip. The pin 55 fits into the cam groove 47. Further, the pin 56 of the auxiliary arm 52 is fitted into the elongated hole 51a of the support arm 51. A torsion spring 57 is provided between the support arm 51 and the auxiliary arm 52, and the spring 57 biases the auxiliary arm 52 in a counterclockwise direction. Also, the bell crank lever 58 is connected to the pin 6 on the mounting plate 59.
The pin 61 of the lever 58 fits into the cam groove 47. 62 is a roller that prevents the belt 23 from coming off. As shown in FIG. 10, the angle detection board 30 has a reflecting plate 63 attached to its lower surface. Reflector plate 6
3, three light emitting-light receiving elements 64, 6
5 and 66 are fixed on the base. The reflecting plate 63 and the elements 64 to 66 cooperate to detect the rotation angle position of the detection plate 30, that is, the cam plate 29, and the timing gears 20 and 21. The elements 64, 65, and 66 are arranged in a straight line, and when the detection plate 30 rotates, the lower surface thereof is scanned along the tracks T ₁ , T ₂ , and T ₃ respectively, and when it faces the reflection plate 63, it receives light. The element receives the light reflected by the reflecting plate 63 and outputs "1", and when it comes off the reflecting plate 63, the reflected light disappears and the element outputs "0". FIG. 10 shows the relative rotational position of the detection plate 30 with respect to the elements 64 to 66 before loading the tape. In the figure, P ₁ is the unloading end position (position before tape loading), P ₂ is the position just before unloading ends (position after tape loading starts), P ₃ is the tape end detection means operation start position, and P ₄ is the pause mode. Position _P5 is the tape loading complete position. If these positions correspond to the pins fitted into the cam grooves 47 of the cam disk 29, the result will be as shown in FIG. However, position P ₃ is a position related to the pin 55, and P ₄ and P ₅ are positions related to the pin 61. The reflector 63 is located between P2 and P5 except for position _P4 on track _T1 , and at position _P2 and _P5 on track _T2 .
Between P ₃ and _{P 5} , it has a predetermined shape that exists at position P ₅ on track T ₃ and has a cutout 67 . Rotation position of angle detection board 30 and each element 6
The relationship with the outputs of 4, 65, and 66 is as shown in the following table.

[Table] The operation of the recording/reproducing apparatus 1 is controlled by a microcomputer reading the combination of output signals from each of the elements 64 to 66. When the information signal becomes [000], the unloading operation is stopped, and when it becomes [111], the tape loading operation is stopped.
The pause mode is confirmed as [010]. Further, as will be described later, the tape end detection means 5 does not work when the information signal is [000], and when the information signal is [110],
It is controlled to work only at [010] and [111]. Next, the operation of the recording/reproducing apparatus 1 having the above configuration will be explained. The small cassette 10 is inserted into the housing 70, moved down, and mounted on the cassette mounting portion 4 as shown in FIG. The lid 13 is opened by the lid opening mechanism 71 as shown in FIGS. 2 and 4, the supply reel 14 is fitted with the supply reel stand 72, and the gear portion 17 of the take-up reel 15 is connected to the tape winding. It meshes with the small diameter gear 73a of the take gear body 73. Furthermore, loading poles 24, 25, tension pole 7
4 and the capstan 75 relatively enter into the front cutout of the small cassette 10. Next, when a recording or playback operation is performed, the loading motor 76 starts, and the belt 77 and wall 7
8, via the worm gear 79 and the drive gear 80,
The timing gears 20, 21, the cam disk 29, and the angle detection disk 30 rotate clockwise (arrow _A1 direction) together with the main gear 28. Due to the rotation of the timing gears 20 and 21, the timing belts 22 and 23 run in the directions of arrows B and C, and the support stands 39 and 45 move into the guide grooves 26 and 27, respectively.
move along. At this time, poles 24 and 25
locks the magnetic tape 11 and inserts it into the cassette 10.
Bring out more. The support stand 39 moves pushing aside the impedance roller 81, and finally the loading pole 24 is pressed against the stopper 82. The impedance roller 81 and the full-width erasing head 83 are mounted on a rotating support base 85 supported by a pole 84.
Both are positioned by a coil spring 86 and a stopper 87. The support stand 45 moves past the front side of the head 48 which is in the retracted position, and finally the loading pole 25 is pressed and locked to the stopper 88. Also, due to the rotation of the cam disc 29, the loading pole 25 passes in front of the head 48, and then the pin 5
5 is guided by the cam groove 47 and displaced toward the outer circumference of the cam disc 29. As a result, the support arm 51 and the auxiliary arm 52 rotate clockwise all at once, and the head 48 approaches the magnetic tape 11 drawn out of the small cassette 10 and attaches thereto. Finally, as shown in FIG. 2, the auxiliary arm 52 rotates independently of the support arm 51, and the support arm 51
is biased clockwise by the spring force of the torsion spring 57 and presses against the stop pole 44, and the head 48 is positioned. Further, due to the rotation of the cam disk 29, the lever 58 rotates the pin 61 counterclockwise with the pin 61 guided by the cam groove 47, and the pinch roller support arm 92 is rotated counterclockwise about the shaft 93 via the connecting levers 90, 91. The pinch roller 49 rotates clockwise and the capstan 7
Crimp to 5. The pressing force of the pinch roller 49 against the capstan 75 is obtained by the spring force of the coil spring 94 between the levers 90 and 91. Further, due to the rotation of the support arm 51, the L-shaped lever 101 is moved to the shaft 102 via the lever 100.
The string 103 is loosened, and the L-shaped lever 104 is rotated clockwise by the spring 105. The string 103 is guided by guide rollers 106 and is mounted at right angles along the periphery of the device, and is connected to the lever 101 and the L-shaped lever 104.
are connected. As the lever 104 rotates, the tension arm 107 is rotated counterclockwise about the shaft 109 by the spring 108, the tension pole 74 reaches the operating position, and the brake band 110 is tensioned. As a result, the recording/reproducing apparatus 1 enters the state shown in FIG. 2, and the magnetic tape 11 pulled out from the supply reel 14 is attached to the fixed guide pole 111, the tension pole 74, and the full-width erasing head 83, and then the impedance roller Attached to 81. The magnetic tape 11 is further helically attached between poles 24 and 25 to the circumferential surface of a guide drum 3 having a rotating video head. Tape 11 is guide drum 3
A rotating video head records or reproduces video signals while traveling along the vehicle. Tape 11 released from attachment to guide drum 3
is attached to the audio control head 48, guided by the guide pole 112, driven to be pinched by the pinch roller 49 and the capstan 75, enters the cassette 10, and is taken up on the take-up reel 15. Capstan 75 is rotated by capstan motor 113. In addition, as the reel drive motor 120 on the lower side of the cassette mounting section 4 rotates clockwise, the oscillating idler 121 that is in pressure contact with the rotating shaft 120a is rotated clockwise.
moves by rolling on the idler movement assisting plate 122, and comes into pressure contact with the intermediate gear 123 meshing with the large diameter gear 73b of the gear body 73. As a result, the rotation of the motor 120 is controlled by the idler 121 and the intermediate gear 12.
3. It is transmitted to the take-up reel 15 via the gear body 73, which rotates clockwise to wind up the tape. Furthermore, the plunger solenoid 125 is energized and the sliding plate 126 moves to the left. As a result, the brake shoes 127 and 128 are separated from the supply reel stand 72 and the gear body 73, respectively, and the braking is released. When a pause operation is performed in the recording/playback mode, the cam disk 29 rotates somewhat in the direction of arrow _A2 independently of the timing gears 20 and 21, and the pinch roller 49 is rotated as shown by the two-dot chain line in FIG. 2 (FIG. 1). Move away from the capstan 75 and enter pause mode. When a stop operation is performed during the recording/reproduction mode, each mechanism that operated during the tape loading operation operates in the reverse direction in the reverse order to the loading operation, and an unloading operation is performed. Also, in the tape rewind mode, the motor 120
rotates counterclockwise, the oscillating idler 121 comes into contact with the supply reel stand 72, and this rotates in the tape winding direction. Next, the tape end detection means which constitutes the essential part of the present invention will be explained with reference to FIGS. 11, 12 and 13. Reference numeral 130 denotes a light emitting source, which is fixed on the chassis 2, and is located at the same position as the small cassette 10 in the plan view.
It is slightly offset to the front of the cassette 10, and is positioned lower than the small cassette 10 in the elevational view. That is, the light emitting source 13
0 does not protrude into the cassette mounting portion 4, and in this connection, the small cassette 10 does not require any space for receiving the light emitting source 130, and the small cassette 10 is effectively miniaturized. Also, the light source 13
0 is located at a lower height than the small cassette 10, that is, lower than the height at which the lower edge of the tape 11 pulled out from the small cassette 10 crosses, and tape loading and unloading operations are performed without being hindered by the light emitting source 130. . The light emitting source 130 has a Y-shaped main body and emits light diagonally upward to both sides in a plane parallel to the front surface of the small cassette 10. 131 and 132 are optical axes of the emitted light beams. An optical axis 131 intersects the tape drawn out from the small cassette 10 from the supply reel 14 diagonally upward in the width direction, and another optical axis 132 intersects the tape drawn out from the small cassette 10 from the take-up reel 15 and this. Crosses diagonally upward in the tape width direction. 133 is an end sensor, 134 is a start sensor, and they are respectively attached to the support bracket 1 on the chassis 2.
35, 136, small cassette 10
They are arranged diagonally above the left and right sides of (cassette mounting section 4). Each sensor 133, 134 has a cylindrical body 137, 138 that projects forward. The end sensor 133 has a cylindrical body 137 installed in the same direction as the optical axis 131, and the optical axis 1 that has passed through the tape.
31 is received. Start sensor 134
The cylindrical body 138 is attached in the same direction as the optical axis 132, and receives the light along the optical axis 132 that has passed through the tape. Here, each sensor 133, 13
4 is provided at the inner part of the cylinders 137, 138, and since the cylinders 137, 138 face diagonally downward, they are less affected by external light and malfunctions do not occur. In particular, the light emitting source 130 and the start sensor 134 are arranged so that the optical axis 132 is not blocked by the pinch roller 49 not only at the initial stage of tape loading but also during the pause mode.
Furthermore, the optical axes 131 and 132 are formed at positions where they are crossed by the poles 24 and 25 before the tape end detection means 5 starts its operation. Furthermore, the relationship between the position _P3 in FIG. 10 and the tape loading mechanism is such that when the elements 64 to 66 detect position _P3 , the tape loading operation is indicated by the dashed line in FIG. 1 and the solid line in FIG. It is determined that the tape path 11B progresses to the state shown in FIG. Next, the operation of the tape end detection means described above will be explained. Before starting the tape loading operation when only the small cassette 10 shown in FIG. 1 is attached, each sensor 133, 134 is in a state equivalent to detecting the transparent tape portion by receiving light from the light emitting source 130. It is in. However, at this time, the output from the elements 64 to 66 is [000], and each sensor 133, 134
Both are in an inactive state, which is equivalent to detecting the magnetic tape section, and the tape loading operation is started.
As soon as the tape loading operation is started, elements 64-
The output from 66 becomes [100], but in this case as well, each sensor 133, 134 is kept inactive and the tape loading operation continues. Therefore, the disadvantages caused by providing the tape end detection means 5 outside the small cassette 10 do not occur. The tape loading operation is carried out by the loading poles 24, 2.
When the tapes 5 and 5 pass somewhat beyond the optical axes 131 and 132, respectively, and reach the state shown by the dashed line in FIG. 1 and in FIG.
The output from 6 becomes [110], and each sensor 133,
134 becomes operational, and the tape end detection means 5 starts its operation at this point, that is, after the start of the tape loading operation. At this time, if the object to be detected is a magnetic tape section, the tape loading operation continues as is, and the tape is loaded as shown in FIG. Furthermore, if the transparent tape section has been pulled out of the cassette at the above point, one of the sensors 13
3 or 134 receives the light transmitted through the transparent tape portion, and the means 5 detects the end of the tape. When the end of the tape is detected, the tape loading operation is immediately stopped, an unloading operation is performed, and the tape is wound and stored in the small cassette 10 based on instructions programmed in the microcomputer in advance. Therefore, an accident in which the tape loading operation progresses unnecessarily and the joint between the magnetic tape section and the transparent tape section comes into contact with the drum 3 and damages the video head is reliably prevented. Furthermore, after the unloading is completed, the device 1 detects that the sensor that received the light is the end sensor 13.
3, rewinding operation, start sensor 134
When , the fast forward operation is automatically performed for a predetermined period of time. The tape winding state within the small cassette 10 allows the subsequent tape loading operation to be carried out to the end position without stopping midway. When the recording/reproducing operation reaches the end of the tape, the end sensor 133 detects the end of the tape, and the recording/reproducing operation is automatically stopped. Next, another embodiment of the tape end detection device of the present invention will be described with reference to FIGS. 14 to 19. In these embodiments, the light emitting source and the light receiving section are designed to satisfy the conditions that the light emitting source and the light receiving section do not protrude into the cassette loading section, and that each element is located at a position that does not interfere with tape loading and unloading operations. The height position of the light-receiving element is changed and the arrangement is different.
Components corresponding to those shown in the figures, FIG. 13, etc. are given the same reference numerals. 14 and 15 show a second embodiment of the device of the present invention. In this tape end detection device 140, the vertical arrangement of the light emitting source and the sensor is reversed from that in FIG. axis 1
31 and 132 are both directed diagonally downward, and an end sensor 133 and a start sensor 134 are arranged below both sides of the cassette. This tape end detection device 140 operates similarly to the devices described above. FIGS. 16 and 17 show a third embodiment of the device of the present invention. This tape end detection device 141 has a light emitting source 130 located below the small cassette 10A and closer to the front of the cassette 10A, and an end sensor 1
33 and start sensor 134 in the cassette 10A.
The optical axis 131,
132 passes through the cassette 10A, and the cassette 10
Inside A, it crosses the tape diagonally upward in the width direction. The cassette 10A has an optical axis 131 on the outer wall surface,
The part where 132 passes is a transparent part. FIGS. 18 and 19 show a fourth embodiment of the device of the present invention. This tape end detection device 142 is different from the above device 141 in that it includes a light emitting source 130, a sensor 133,
The vertical arrangement is reversed from that of 134, and the light emitting source 130 is arranged on the upper side, and the sensors 133 and 134 are arranged on the lower side. In the cassette 10B, the portions of the outer wall surface through which the optical axes 131 and 132 pass are transparent. The above-mentioned detection devices 141 and 142 are connected to sensors 133 and 13 in order to detect the tape end within the cassette.
4 is constructed to operate immediately upon attachment of the cassette. In addition, the light emitting source 130 and the sensor 133,
134 is not moved in connection with the tape loading operation but is fixedly provided, so the structure is simple. As described above, the tape end detection device of the recording/reproducing apparatus according to the present invention has a light emitting source and a light receiving section that face each other at different height positions, and both of them are located outside the cassette loading section. The light emitting source does not fit into the cassette when the cassette is installed, and the cassette does not have a light emitting source. Since no space is required to receive the source, the cassette can be effectively miniaturized, and since the optical axis is oblique, the light emitting source and light receiving section can be connected so that the optical axis passes between each member. Restrictions on placement are relaxed compared to conventional designs, making it easier to design, and in particular, the light receiving part is installed facing the optical axis direction of the light beam directed from the light emitting source to the light receiving part, and a cylindrical body is provided in the front. Because of this, it has features such as being less susceptible to adverse effects from external light and preventing malfunctions.

[Brief explanation of the drawing]

1 and 2 respectively show the state of a recording and reproducing apparatus to which an embodiment of the tape end detection device of the present invention is applied, before loading the tape, and the state in the recording and reproducing mode after tape loading is completed. 3 is a perspective view showing the tape loading mechanism taken out from FIG. 1, FIG. 4 is a perspective view of a small cassette that can be attached to the recording/reproducing apparatus of FIG. 1 with the lid open, and FIG. 3 is an exploded perspective view showing the structure of the timing gear portion in FIG. 6A is a cam diagram of the cam groove of the cam disk, FIG. 8 is a perspective view of the mechanism related to the cam disk of FIG. 6A, and FIG. 9 is a diagram showing the head support arm and auxiliary arm in FIG. 8. FIG. 10 is an exploded perspective view, FIG. 10 is a plan view of the angle detection board shown in FIG. 5 in a rotational position before loading the tape, and FIG. In the figure, a perspective view showing the tape end detection means taken out, and FIGS. 12 and 13 are plan views at the start of the tape end detection operation showing the positional relationship of the tape end detection means with respect to the small cassette, drum, and loading pole, respectively. and Elevation, Figures 14 and 1
Figure 5, Figure 16 and Figure 17, Figure 18 and Figure 1
FIG. 9 is a plan view and an elevation view, respectively, schematically showing second, third, and fourth embodiments of the tape end detection device according to the present invention. 1...Recording/reproducing device, 3...Guide drum, 4
...cassette mounting section, 5...tape end detection means,
6... Tape loading mechanism, 10, 10A, 10B...
...Small cassette, 11...Magnetic tape, 12...
Cassette housing, 13...lid, 14...supply side reel, 15...take-up side reel, 20, 21...timing gear, 22, 23...timing belt,
24, 25...Loading pole, 26, 27
...Guide groove, 28...Main gear, 29...Cam board, 30...Angle detection board, 47...Cam groove, 4
8...Audio control head, 49...
...Pinch roller, 63...Reflector, 64, 65,
66... Light emitting-light receiving element, 67... Hole, 75
... Capstan, 76 ... Loading motor, 83 ... Full width erase head, 130 ... Light emitting source, 131, 132 ... Optical axis, 133 ... End sensor, 134 ... Start sensor, 135, 1
36... Support bracket, 137, 138... Cylindrical body, 140, 141, 142... Tape end detection device.

Claims (1)

[Scope of claims for utility model registration] (1) Pull out the tape from the cassette to record and/or
Or, in a device that is applied to a playback device and detects the end of a tape using a light emitting source and a light receiving section facing each other, the light emitting source and the light receiving section are set at different heights so that both of them are removed from the cassette loading section. 1. A tape end detection device for a recording/reproducing apparatus, wherein the optical axis of the light beam directed from the light emitting source toward the light receiving section crosses obliquely with respect to the tape and its width direction. (2) The tape end detection according to claim 1 of the utility model registration claim, wherein the light receiving section is installed toward the optical axis direction of the light beam directed from the light emitting source toward the light receiving section, and has a cylindrical body on the front side. Device.