JP3420813B2 - Brake equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake device in a magnetic recording / reproducing device such as a video tape recorder (hereinafter, referred to as a VTR), and more particularly to a fast forward (FF) or rewind (FF) device. The present invention relates to a brake device for applying a main brake to and stopping a supply reel and a take-up reel of a video cassette when stopping (STOP) from the state of (REW) or switching operation modes. 2. Description of the Related Art Conventionally, in a VTR, fast forward (FF)
Alternatively, when stopping (STOP) from the rewind (REW) state, when the stop key is operated, the main brake mechanism operates from the fast forward or rewind state, and the supply side reel and the winding side of the video cassette. The brake is applied to the reel to stop the tape running. In this case, in many cases, after the tape running is stopped, an operation such as recording or reproduction is performed to shift to a mode such as recording or reproduction, and a stop (STO) is performed from a fast forward (FF) or rewind (REW) state.
When P) is instructed (operated), it is necessary to operate the main brake mechanism as soon as possible to stop the tape running. For this reason, the following instantaneous brake mechanism has been adopted. FIG. 11 is a plan view showing a conventional main brake device, and FIG. 12 is a longitudinal sectional view of a worm 16 and a cam gear 17 in FIG. These figures are for a VHS (Vi-deo Home System) type VTR. In FIG. 11, reference numeral 1 denotes a cylinder on which a rotary head is mounted, 2 denotes a supply side reel base, 3 denotes a take-up side reel base, 4 and 5 denote guide rollers for loading, and 6 denotes a tape for running the tape. A capstan 7 is a pinch roller, 8 and 9 are reel driving means for driving the reel bases 2 and 3, 10 is a mode motor for setting various operation modes, and 11 to 15 are torques of the mode motor 10. To the worm 16, and 16 is a claw portion 16a.
The worm 17 has a cam gear 17 for engaging with the worm 16 and setting various operation modes. The cam gear 17 has a cam groove (not shown) for setting various operation modes on its surface. . Except for the claw portion 16a of the worm 16 and a part of the cam gear 17, the worm 16
A sub-plate 18 is provided on the chassis so as to cover the upper surface of the cam gear 17. Reference numeral 20 denotes a slider, one end of which is urged by a spring 19 and the other end of which is connected to a rotary lever 21 at a connecting portion 22. Cam pin 2 engaging with a cam groove (not shown) on the surface of the cam gear 18 through the opening
1a, and a rotation lever 24 having a brake releasing projection 21b at one end thereof is rotatable about a rotation shaft 25, and the brake releasing projection 2 is provided at one end thereof.
1b, and has an engaging pin 24b which engages with a cam groove (not shown) on the surface of the cam gear 18 through an opening formed in the sub-plate 18 on the lower surface. A rotation lever connected to one end of a brake control lever 27, 27 is a brake control lever, 28 is rotatable about a rotation shaft 29, and both ends are respectively provided to the brake control lever 27 and the brake control slider 30. A rotary lever for connecting and transmitting the movement of the brake control lever 27 to the brake control slider 30 is urged leftward by a spring 31 in the drawing, and cam portions 30a and 30b for applying a load to the side wall surface. A brake control slider 32 slidably disposed on a chassis is rotatable about a rotation shaft 33, and the brake control slider 32 is provided at one end. Cam portion 3 of the side wall surfaces of the use slider 30
A supply-side main brake having a cam pin 32a that can be engaged with the brake control slider 0a and a brake portion 32b at the other end. The take-up main brake 36 having a cam pin 34a engageable with the cam portion 30b and a brake portion 34b at the other end is connected between the supply-side main brake 32 and the take-up main brake 34,
These springs apply biasing forces to the main brakes 32 and 34 in directions opposite to each other. 37 is rotatable about a rotation shaft 38, one end is urged clockwise by a spring 39, the other end is provided with a brake portion 37 a, and a tension for applying a back tension to the supply side reel base 2. It is a lever. T is a video tape which can travel on a path from the supply reel 2 to the take-up reel 3 via the rotary cylinder 1, H1 is a full width erasing head, H2 is a voice erasing head, and H3 is a voice control head. In the above configuration, for example, fast forward (F
When the stop key is operated in the state of F) or the rewinding (REW) state (shown), the mode motor 10 rotates, and the claw 16a of the worm 16 is moved in the F2 direction (FIG. 12).
(See FIG. 12) and abuts against one end of the slider 20 to move the slider 20 in the direction of arrow G (see FIG. 12) against the urging force of the spring 19. As a result, the rotary lever 21 rotates in the direction of arrow E2 (see FIG. 11), the engagement between the projection 21b and the cam pin 24a of the rotary lever 24 is released, and the cam pin 24a of the rotary lever 24 is turned off. By dropping into the notch 21c, the rotation lever 24 rotates in the direction of arrow A1 and the lever 2
7 moves in the direction of arrow B1 and the rotary lever 28 moves in the direction of arrow C1.
And the brake control slider 30 moves in the direction of arrow D1.
Move in the direction. These directions are generated by the urging force of the spring 31 attached to the brake control slider 30 in the direction of arrow D1. When the brake control slider 30 moves in the direction of arrow D1, the supply side main brake 32
Of the brake control slider 30 is disengaged from the cam pin 32a, and at the same time, the cam pin 34a of the take-up main brake 34 and the brake control slider 30 are disengaged.
Is disengaged from the cam portion 30b. Accordingly, the supply side main brake 32 rotates counterclockwise, and the winding side main brake 34 rotates clockwise.
2b and 34b are pressed against the supply-side reel base 2 and the take-up reel base 3, respectively, to apply a brake. By the way, in the above instantaneous braking mechanism,
After the stop key is operated, the claw 16 a of the worm 16 abuts on one end of the lever 20, and the claw 2
When the engagement of the cam pin 24a of the rotary lever 24 with the rotation lever 1b is released and a braking operation is performed, there is a problem that noise is emitted. On the other hand, those without such an instantaneous brake mechanism have a long time until the main brake is applied, and cannot cope with high-speed fast-forward (FF) or rewind (REW). As described above, the conventional instantaneous braking mechanism has a problem that a noise is generated at the same time as the braking operation is performed after the stop operation. In view of the above problems, it is an object of the present invention to provide a brake device which can apply a main brake quickly without using an instantaneous brake mechanism. A brake device according to the present invention includes a motor that rotates in accordance with an operation mode, and a cam gear driven by the motor, wherein one end of a brake control lever is engaged. A first cam portion for controlling ON / OFF of the braking operation and one end of a loading drive lever are engaged to provide a second cam portion for controlling ON / OFF of the loading operation; When a mode is designated, one end of the brake control lever is set to a brake off position in the first cam portion, and one end of the loading drive lever at that time is engaged. The shape of the second cam portion is such that one end of the loading drive lever escapes from the operation mode position before and after the operation mode position, but has a higher load than the other. A cam gear that is shaped to increase, the braking mechanism that operates in conjunction with the brake control lever, before
Cam angle detecting means for detecting the cam angle of the cam gear;
Set the motor to a specific
When controlling to rotate and stop the cam angle, the cam angle detection
After the output means detects the start point of the specific operation mode.
After a predetermined time has elapsed, the motor is stopped, and
Thereafter, one end of the loading drive lever is connected to the second
To return to the maximum load point of the cam section,
Means for performing control to reverse the motor . According to the present invention, a specific operation mode (for example, F
F or REW), a force that mechanically returns to this load point acts even when the load exceeds the maximum load point, and one end of the loading drive lever is always in the state immediately before the brake is turned on. Therefore, the tape can be stably stopped in a short time with the stop operation. Also cam
The cam angle detected by the angle detecting means and the operation mode
Specified by the time control of the motor
When transitioning to the operation mode (for example, FF or REW)
Make sure that one end of the loading drive lever is
It is possible to control so as to reach a major point. An embodiment will be described with reference to the drawings. FIG. 1 is a plan view showing an embodiment of the brake device according to the present invention, and FIG. 2 is a diagram showing a structure on the back side of the cam gear 63 in FIG. These figures show VHS (Vi-deo Hom)
e System) type VTR, the cam pin 65a of the brake control lever 65 is in the fast forward (FF) or rewind (REW) position of the brake control cam groove 64, and the brakes 70, 72 are moved from the reel bases 52, 53. It shows a state in which the video tape T can be fast-forwarded (FF) or rewound (REW) away. In FIG. 1, reference numeral 51 denotes a cylinder on which a rotary head is mounted, 52 denotes a supply-side reel table, 53 denotes a take-up reel table, 54 and 55 denote guide rollers for loading, and 56 denotes a tape for running the tape. Capstan, 5
7 is a pinch roller, 58 and 59 are reel driving means for driving the reel stands 52 and 53, and 60 is a capstan 5
A belt 61 for transmitting the driving force 6 to the reel driving means 58, and a mode motor 61 for setting various operation modes, the amount and direction of rotation of which are controlled by control means (not shown). is there. Reference numeral 61a denotes a worm attached to the rotation shaft of the mode motor 61, and 62 denotes a worm wheel that meshes with the worm 61a. The worm 61a and the worm wheel 62 constitute a worm gear.
It has a transmission function for transmitting to Here, the number of the worm gears is plural (for example, two) so that the force is easily transmitted to the cam gear 63. A cam gear 63 meshes with the worm wheel 62 to set various operation modes. The cam gear 63 has cam grooves for setting various operation modes on the front and rear surfaces. Reference numeral 64 denotes a cam groove for brake control among the cam grooves on the front surface side of the cam gear 63. On the back side of the cam gear 63, a loading control cam groove 81 is formed to engage with a cam pin 82a provided at one end of the loading drive lever 82 as shown in FIG. The loading control cam groove 81 has a substantially spiral shape, and the FF or REW position is stopped in the cam groove 81 near the center of the cam gear (STO).
P) V for setting to be closest to the position
A groove 81a is provided. A cam angle detecting means (not shown) for detecting the position (cam angle) of the cam pin 82a or 65a on the cam groove 81 or 64 is provided on the front surface or the rear surface of the cam gear 63. The loading drive lever 82 is provided on a chassis (located on the lower surface side of the cam gear 63 in FIG. 1) so as to be rotatable about a rotation shaft 83, and the cam pin 82a is provided at one end. The other end is provided with a connecting portion 82b for connecting to the loading control slider 84. The loading control slider 84 is connected to a cassette holder (FIGS. 8 to 1) via a loading drive gear.
0) to the loading position or the unloading position. At the time of front loading, the cam gear 63 rotates in the direction J1 in FIG. The mounted cassette holder (not shown) is inserted inside (however, FIG. 2 shows a state at the time of FF or REW). At the time of unloading, the cam gear 63 rotates in the direction J2 to move in the direction indicated by arrow K2 in FIG. 2 to move a cassette holder (not shown) in the discharging direction. Reference numeral 65 denotes a rotatable shaft about a rotation shaft 66, and has a cam pin 65a at one end for engaging with a brake control cam groove 64 on the surface of the cam gear 63,
A brake control lever having an engagement pin 65b connected to a brake control slider 67 at the other end thereof is urged rightward in the figure by a spring 69, and has cam pins 70a, 72a of the main brakes 70, 72 on the back surface. The cam portions S1 and S2 (see FIGS. 3 (a) and 3 (b)) are formed to engage with the support portion 68 protruding from the chassis. Slider, 67a
Is an elongated hole engaged with and connected to the engagement pin 65b, 67b is a slide elongated hole slidably engaged with the support portion 68, 70 is rotatable around a rotation shaft 71, and one end is provided with the brake control. The cam slider 70 has a cam pin 70a engageable with the cam portion S1 on the rear surface of the slider 67, and has a brake
0b, supply-side main brake 72, rotary shaft 73
A cam pin 7 which is rotatable around a center and is engageable at one end with a cam portion S2 on the back surface of the brake control slider 67.
A take-up main brake 74 having a main portion 2a and a brake portion 72b at the other end is connected between one end of the supply-side main brake 70 and one end of the take-up main brake 72. , 72 that apply biasing forces in opposite directions to each other. Reference numeral 75 designates a rotatable shaft 76, one end of which is urged counterclockwise by a spring 77, and the other end of which is connected to a brake band 78 which slides on the supply reel base 52. The supply side reel base 5 is connected to the tension arm 75c having the
2 and a tension lever for applying a back tension to the video tape T. The state shown is FF
Or, in the REW state, no tape tension is applied. T is a video tape that can run on the path from the supply reel 52 to the take-up reel 53 via the rotary cylinder 51, H1 is a full width erase head, H2 is an audio erase head, and H3 is an audio control head. FIGS. 3A and 3B show FF or REW of FIG.
3 shows the positional relationship between the supply-side main brake 70, the take-up side main brake 72, and the respective reel bases 52, 53 in an enlarged manner. In FIG. 3A, the cam pin 70a of the supply side main brake 70 is engaged with the peak of the cam portion S1 on the back surface of the brake control slider.
The brake section 70b is separated from the supply-side reel base 52. In FIG. 3B, the cam pin 72a of the take-up main brake 72 is engaged with the peak of the cam portion S2 on the back surface of the brake control slider, and the brake portion 72b is separated from the take-up reel base 53. are doing. FIG. 4 shows S from the state of FF or REW in FIG.
FIG. 5 shows the structure on the back side of the cam gear 63 in FIG. 4. FIGS. 6A and 6B are enlarged views showing the positional relationship between the supply-side main brake 70, the take-up-side main brake 72, and the reel bases 52 and 53 in the state of STOP in FIG. is there. For example, when a stop key (not shown) is operated,
When the cam gear 63 is rotated in the J2 direction by the mode motor 61, the cam pin 65a at the tip of the brake control lever 65 moves in the meandering brake control cam groove 64 and is slightly rotated counterclockwise. 65
Similarly, the engagement pin 65b also slightly moves counterclockwise, that is, rightward in the figure, and accordingly, the brake control slider 67 also moves rightward (the biasing direction of the spring 69). At this time, on the rear surface of the cam gear 63, the cam pin 82a of the loading drive lever 82 is rotated by the cam gear 63 in the J2 direction as shown in FIG. And move to the stop position. Even when shifting to this position, since the cam pin 82a is at the same position with respect to the center of the cam gear 63, the loading drive lever 82 is not driven, so that the loading control slider 84 cannot move from the state of FIG. Absent. As described above, the brake control slider 67
Moves rightward (the biasing direction of the spring 69), so that the cam portions S1 and S2 of the slider 67 also move.
As shown in FIG. 6A, the cam pin 70a of the supply-side main brake 70 is
As shown in FIG. 6B, the cam pin 72a of the winding-side main brake 72 also enters the valley (recess) of the cam portion S2 by the urging force of the spring 74, as shown in FIG.
As a result, the brake unit 7 of the supply side main brake 70
0b is pressed against the supply-side reel base 52, and the brake portion 72b of the take-up main brake 72 is
And mechanically apply a brake to each of the reel bases 52 and 53 (hereinafter referred to as brake-on). Next, the above-mentioned FF or REW state and ST
The engagement of the cam pins 65a and 82a with the shapes of the cam grooves 64 and 81 on the front and back surfaces of the cam gear 63 in the OP state will be described in detail with reference to FIG. FIG. 7A shows the state of FF or REW and STO.
FIG. 7B shows the cam shape of the loading control cam groove 81 and the operation of the cam pin 82a in the state P.
Shows the cam shape of the main brake control cam groove 64 and the operation of the cam pin 65a. The cam angles (A), (B) and (C) will be described on the grooves 81 and 64, respectively. Cam angle
The range (indicated by L) from (B) to beyond (C) is VT
R corresponds to a range (FF or REW position) in an electrically FF or REW state. The range indicated by reference symbol M is the range (S) in which the VTR is electrically in the STOP state.
TOP position). The cam angle (A) is a starting angle at which the main brakes 70 and 72 are turned on. The cam angle (B) corresponds to the valley position of the V-shaped groove 81a. Now, fast forward (FF) or rewind (REW)
When the key is operated by operating means (not shown) so as to stop (STOP) from the state of (1), the cam pins 82a, 65
When a moves from the cam angles (B) and (A) in the direction of the stop (STOP) position, the brake is mechanically turned on, and when the cam angle detecting means detects the STOP position M, the VTR is electrically stopped. Become. When a key is operated to perform fast-forward (FF) or rewind (REW) from the stop (STOP) state, the control means of the mode motor 61 determines that the cam pins 82a and 65a have the cam angles (A). To FF or REW
The motor is controlled to move in the direction of the position. In the course of the movement, after a lapse of a predetermined time (for example, 30 msec or more) from the detection of the start point of the FF or REW position L, the motor 6
1 is electrically stopped, and then the cam pin 82a of the loading drive lever is easily returned to the valley (ie, the maximum load point) of the V-shaped groove 81a of the cam groove 81 for a predetermined time (for example, 20 msec). ) Control to reverse the motor 61 is performed. Here, the motor 61 is electrically stopped after a predetermined time (for example, 30 msec or more) has passed since the cam angle detecting means detected the start point of the FF or REW position L because the cam pin 82a Is passed over the cam angles (A) to (B) to cause overrun, so that the cam pin 82a is stopped at a position above the cam inclined surface. And
After that, the motor 61 for a certain time (for example, 20 msec)
The control for inverting the cam is performed in order to provide an opportunity for the cam pin 82a of the loading drive lever to go down the cam inclined surface. Thereby, the cam pin 82a mechanically returns to the valley (ie, the maximum load point) of the V-shaped groove 81a down the cam inclined surface, and is stabilized at the cam angle (B). The time for the overrun and the time for the reversal may be changed depending on the type of the device or due to mechanical variations. Here, in the state where the cam pin 82a is at the cam angle (c), as shown in FIG.
Is due to the pressure of the cassette holder on the reel base,
As shown, a downward force (indicated by arrow F) is acting. Therefore, the cam pin 82a generates a force toward the stable point (B) where the force is released, and this force is generated by the mode motor 61a.
Is a mechanically turning force (ie, a returning force). In addition, since the mode motor 61 is reversed for a certain time at the cam angle (c) as described above, it is possible to reliably return to the stable point (B). Further, since the number of the worm gears (61a, 62) for reducing the rotation of the mode motor 61 is plural (for example, two), the returning force is more easily transmitted, and the mode motor 61 61 turns, cam pin 8
2a can be reliably returned to the stable point (B). As described above, if the cam pin 82a is controlled to always be at the stable point (B) in the FF or REW state, the running of the tape T is stopped from this state (STO).
In order to lead to the P) state, the rotation of the cam gear 63 is always
The brake is turned on only by the transition time from (B) to (A), and the tape T can be stably stopped in a short time. Next, the appearance of a VTR mechanism equipped with the above-described brake device will be described with reference to FIGS. FIG. 8 shows a state before a video cassette is inserted into the cassette holder 90. The cassette holder 90 is connected to a loading drive gear 91,
The loading drive gear 91 meshes with the tooth portion 84a of the loading control slider 84. Sliding grooves 84b and 84c are formed in the loading control slider 84, and the grooves 84b and 84c are slidably engaged with supporting portions 92 and 93 projecting from the side surface of the chassis. The lower portion of the rear end of the loading control slider 84 (the lower portion of the groove 84c) and the loading drive lever 82 shown in FIG. 2 (and FIG. 5) are connected by a connecting portion 82b. FIG. 9 shows the bottom side of FIG. A supply-side main brake 70 and a take-up main brake 72 are attached to the bottom surface. FIG. 10 shows a state where the video cassette 95 is loaded into the VTR mechanism of FIG. At the time of loading, the cassette holder 90
When the video cassette 95 is inserted into the
1 rotates the above-described cam gear 63 to the loading position of the cassette, whereby the loading control slider 84 moves in the direction of arrow K1. As a result, the loading drive gear 91 meshed with the slider 84 moves clockwise. It rotates to move the cassette holder 90 onto the reel table inside the VTR mechanism. Thereafter, the loading of the tape T is performed as shown in FIG. At the time of unloading, after the tape T is unloaded from the state shown in FIG. 10, the mode motor 61 rotates in the reverse direction to rotate the cam gear 63 to the unloading position of the cassette, thereby controlling the loading. As a result, the loading drive gear 91 rotates counterclockwise to move the cassette holder 90 from the reel stand inside the VTR mechanism to the original cassette discharge position, as shown in FIG. The state before the cassette insertion as shown in FIG. In the above embodiment, the case of stopping (STOP) from the fast forward (FF) or rewind (REW) state has been described. However, the present invention is not limited to this, and the operation mode is changed to another mode. In the case of switching, the present invention can also be applied to a case where the main brake is once applied to the supply side reel and the take-up side reel to stop, and then the mode is immediately shifted to another mode. As described above, according to the present invention, since the instantaneous braking mechanism is not used, the number of parts can be reduced and, for example, when the cam pin is in the FF or REW state, the cam pin is always turned on immediately before the brake is turned on. , It is possible to stably stop the tape in a short time with the STOP operation.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an FF in a brake device according to one embodiment of the present invention.
Alternatively, a plan view showing a state of a main brake at the time of REW. FIG. 2 is a diagram showing a structure on a back surface side of the cam gear in FIG. 1; FIG. 3 shows a supply side in a state of FF or REW in FIG. 1,
The figure which expands and shows the positional relationship between each main brake of a winding side, and each reel stand of a supply side and a winding side. FIG. 4 is a plan view showing a state where the state has shifted to STOP from the state of FF or REW in FIG. 1; FIG. 5 is a view showing a structure of a rear surface side of the cam gear in FIG. 4; 6 is an enlarged view showing a positional relationship between supply-side and take-up side main brakes and supply-side and take-up side reel stands in a state of STOP in FIG. 4; FIG. 7 is a diagram showing cam shapes and cam pin operations of a loading control cam groove and a main brake control cam groove in the FF or REW state and the STOP state. FIG. 8 is a VTR on which the brake device according to the present invention is mounted.
FIG. FIG. 9 is a perspective view showing the bottom side of FIG. 8; FIG. 10 is an exemplary perspective view showing a state where a video cassette is inserted into the VTR of FIG. 8; FIG. 11 is a plan view showing a conventional brake device. FIG. 12 is a longitudinal sectional view of a worm and a cam gear in FIG. 11; DESCRIPTION OF SYMBOLS 51 ... Rotating cylinder 52 ... Supply-side reel stand 53 ... Winding-side reel stand 54,55 ... Loading guide roller 56 ... Capstan 57 ... Pinch rollers 58,59 ... Reel driving means 61 ... Mode motor 61a worm 62 worm wheel 63 cam gear 64 brake control cam groove 65 brake control levers 65a, 82a cam pin 67 brake control slider 69 brake control slider biasing spring 70 supply side main brake 70a, 72a: Cam pins 70b, 72b: Brake part 74: Main brake biasing spring 81: Loading control cam groove 81a: V-shaped groove 82: Loading drive lever 84: Loading control slider 90: Cassette holder 92: Video cassette

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G11B 15/18 G11B 15/22 G11B 15/10

Claims (1)

(57) [Claim 1] A motor rotating in accordance with an operation mode, and a cam gear driven by the motor, wherein one end of a brake control lever is engaged to perform a brake operation. A first cam portion for on / off control is engaged with one end of a loading drive lever to turn on / off the loading operation.
A second cam portion for off-control, and when a specific operation mode is designated, one end of the brake control lever is set to a brake off position in the first cam portion; The shape of the second cam portion with which one end of the loading drive lever is engaged,
A cam gear shaped so that one end of the loading drive lever escapes from the operation mode position before and after the operation mode position and has a greater load than the other, and operates in conjunction with the brake control lever. Brake mechanism and cam angle detecting means for detecting a cam angle of the cam gear
To set the motor to a specific operation mode,
When controlling to rotate and stop the cam angle, the cam angle detection
After the output means detects the start point of the specific operation mode.
After a predetermined time has elapsed, the motor is stopped, and
Thereafter, one end of the loading drive lever is connected to the second
To return to the maximum load point of the cam section,
Means for performing control to reverse the motor .