JP2675601B2 - Constant speed cassette loading device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Industrial field of application) The present invention relates to a constant speed cassette loading device provided in a loading mechanism of a video tape recorder (hereinafter referred to as VTR).

(Prior Art) When mounting a cassette on a VTR, insert the cassette horizontally from the cassette insertion opening that opens in a rectangular shape on the front of the VTR, and then push it in to a certain extent, then the cassette is automatically loaded. Rarely, it is transported to a predetermined mounting position inside the device. When the eject operation is performed, the cassette is automatically removed from the predetermined mounting position and is conveyed to the insertion port. Such a mechanism in a VTR is known as a front cassette loading mechanism.

By the way, the front loading mechanism is usually configured so that the loading gear is rotationally driven by receiving power from a dedicated loading motor. The loading gear is for moving the cassette holder movably arranged inside the VTR from the cassette receiving position to a predetermined mounting position or from this mounting position to the cassette receiving position.

(Problems to be Solved by the Invention) According to the conventional cassette loading device described above,
Since the loading mechanism is simply driven by the dedicated loading DC motor, there is a problem that the load is easily affected. If the friction coefficient of the loading mechanism changes when the operating environment changes, or if oil or other substances stick to the friction parts of the loading mechanism due to long-term storage, place the cassette in the specified mounting position. There is a problem that an error occurs in the mounting position even when the paper is conveyed. When an error occurs in the cassette mounting position, when the tape is loaded, the tape is displaced in the width direction with respect to the pull-out pole or the rotary cylinder, and the tape is damaged, or good recording / reproduction is impossible.

Therefore, an object of the present invention is to provide a constant-speed cassette loading device that can always obtain a stable cassette loading operation at a constant speed and can mount the cassette at an accurate position.

[Structure of the Invention] (Means for Solving the Problems) In the present invention, the loading power for loading the cassette is obtained from the capstan motor having a large capacity, and is originally attached to the capstan motor. The configuration is such that the servo mode can be effectively used to switch the servo mode to a loading mode.

(Operation) With the above-mentioned means, since the power of the capstan motor is used, a large amount of power can be obtained. Moreover, since the servo circuit also works for loading, stable and reliable cassette transportation and mounting at a predetermined position are possible. Done.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. Mode controller
Reference numeral 11 is a device for electrically and mechanically switching and controlling the operating state of the VTR, which has a mode gear having a plurality of cam grooves, and the rotational position information of this mode gear (corresponding to the operating mode of the VTR). It has a mode switch for detecting.

In the figure, the transmission path of the electric signal between the blocks is shown by a single line, and the transmission path of the power is shown by a double line.

The mode gear of the mode control device 11 is controlled by a motor 12 for tape loading and mode control (hereinafter referred to as a sub motor) to rotate in the forward or reverse direction. Depending on the rotational angle position of the mode gear, the clutch switching mechanism, the switching lever, the operating lever, etc. are controlled by a plurality of cams provided in this gear, and the operation mode of the VTR is set.

The sub motor 12 is a relatively small motor, and its power is used for the mode control device 11 and the tape loading device 13. The rotational power of the sub motor 12 is used for the operation mode setting mechanism 14. When the power of the sub motor 12 is transmitted to the tape loading device 13 and the operation mode setting mechanism 14, it is transmitted via the mode gear inside the mode control device 11.

In this embodiment, the mode control device 11 can transmit the power of the capstan motor 15 to the cassette loading device 17 by the clutch mechanism. The power transmission path hatched in the figure is the power utilization path of the capstan motor 15. When the power of the capstan motor 15 is used for cassette loading 17, the operation mode of the servo circuit 16 acting on the capstan motor 15 is switched for loading, for example, rotation of the capstan motor 15. A target value is set to keep the speed at 900 rpm. Therefore, when loading the cassette,
A servo mode switching signal is supplied from the mode control device 11 to the servo circuit 16. When the cassette reaches a predetermined mounting position, a detection signal is obtained from the cassette loading device 17 and supplied to the mode control device 11. As a result, the mode control device 11 releases the coupling between the capstan motor 15 and the cassette loading device 17, and switches the servo mode to the normal capstan control mode.

The power transmission path for loading the capstan motor 15 and the power transmission path for the sub motor 12 have been described above.

In the actual operation of the VTR, first, the cassette is slotted in, so that the detection signal is detected by the mode control device 11.
Given to. As a result, the servomotor 12 is controlled to rotate the mode gear and drive the clutch gear.
Then, the power of the capstan motor 15 is transmitted to the cassette loading device 17, and the above operation is obtained. When the cassette loading is completed, the tape loading is now performed so that the tape is pulled out from the cassette and attached around the rotating cylinder. For this tape loading, the sub motor 12 is rotated, the drive lever inside the mode control device 11 is driven, and the rotating force drives the slider that supports the tape pull-out pole. When the tape loading is completed, it enters a standby state, after which a control signal according to an external operation is input to the mode control device 11, and the submotor 12 is controlled to rotate normally or reversely by the logic circuit and its power is set to the operation mode. It is transmitted to the mechanism 14 or the tape loading device 13 (at the time of unloading).

FIG. 2 is an exploded view of the VTR front loading mechanism.

In FIG. 2, reference numerals 200 and 300 denote left and right chassis body plates, which are mounted upright in parallel on a main chassis (not shown). The open ends of the chassis body plates 200 and 300 are connected by the connecting plates 250 and 260, and the front end (the direction of the arrow A1 in the drawing) of the connecting plate 250 is bent vertically downward to form a bent portion 251. ing. The bent portion 251 constitutes a locking member of the opening / closing lid. A cassette holder 100 is arranged between the chassis body plates 200 and 300. The cassette holder 100 is supported by the chassis body plates 200 and 300 and is movable in the front and back directions (directions A1-A2 in the drawing). ， At the rear part, it is possible to descend in the direction of arrow B1, and it is possible to rise in the direction of arrow B2 from the lowered position.

The cassette holder 100 has a rectangular cassette holding portion when viewed from the front, and includes a lower plate 101, an upper plate 102, and left and right plates 103, 1
04. The left and right plates 103 and 104 are the Shoshi body plates 200 and 3
It is almost parallel to 00. Here, the pins P1 and P2 vertically project from the left and right plates 103 and 104, respectively, from the plates. The pins P1 and P2 are located on the same axis. Also, plate 1
A pin P3 is also provided on the outside of 04.

Corresponding to the pin P1 above, the chassis body plate 200,
An L-shaped guide groove 201 having a substantially horizontal portion and an upper and lower portion is formed, and the pin P1 is inserted therein. Meanwhile, pin P2
Corresponding to P3 and P3, L-shaped guide grooves 301 and 302 are formed in the chassis body plate 300, and pins P2 and P3 are inserted therein. Therefore, the cassette holder 100 is supported by the chassis body plates 200 and 300 from the front position,
It can move in the depth direction (direction of arrow A2) and then descend in the direction of arrow B1. The state where the cassette holder 100 is lowered is a state where the cassette is conveyed to a predetermined mounting position, and when the cassette holder 100 is located on the front side, it is a position when the cassette is returned and taken out, or a new cassette is inserted. It is the receiving position.

The drive mechanism of the above cassette holder is configured as follows. A shaft 303 is provided on the chassis body plate 300 toward the outside, and a first loading cam 400 is rotatably attached to the shaft 303. The first loading cam 400 is
The pin P2 is engaged with the hole formed in the arm 401. The gear portion of the first loading cam 400 meshes with the transmission gear 500. The transmission gear 500 can rotate integrally with a shaft 502 whose both ends are supported by the chassis body plates 200 and 300.
The shaft 502 is further connected to the gear 503 outside the chassis body 200. Therefore, the rotation of the first loading gear 400 is transmitted to the gear 500, the shaft 502, and the gear 503. In addition,
A lid drive lever 900 is rotatably attached to the shaft 502, and this is a member for controlling the lid provided in the cassette insertion port.

On the other hand, the chassis body plate 200 is also provided with a shaft 202, and a second loading cam 600 is rotatably attached to the shaft 202, and the gear 503 meshes with the gear portion thereof.
An arm portion 601 is also formed on the second loading cam 600, and a hole portion of this arm portion 601 engages with the pin P1. Therefore, the first and second loading cams 400 and 600 can synchronously drive the cassette holder 100 via the pins P1 and P2. Power for driving is transmitted by driving a third loading cam 700, which is attached to the shaft 303 so as to overlap with the first loading cam 400, by a worm gear 800. The first and third loading cams 400 and 700 are engaged by a spring so as to interlock with each other. The worm gear 800 is unitized and attached to the chassis body plate 300, and receives power from the capstan motor 15 via the clutch mechanism.

The worm gear 800 is rotatably supported by a support mechanism 801 that is fixed to the chassis body plate 300 with screws. A lever 802 for detecting the rotational position information of the loading cam 400 is also attached to the support mechanism 801,
The tip of the lever 802 is driven by a protrusion 402 formed on the loading gear 400. Then, when the lever 802 is rotationally driven, the switch 803 is controlled to be switched. That is, since the movement position of the cassette holder 100 can be detected by the rotation position of the loading gear 400,
If the rotation position of the loading gear 400 is detected by the lever 802 and the switch 803, it corresponds to detecting the loading progress of the cassette.

FIG. 3 shows a clutch mechanism that transmits the rotational power of the capstan motor 15 to the worm gear 800 or disconnects it. The figure is shown from the back side of the chassis (not shown) of the VTR, and the capstan motor 15 is coaxially provided with a gear 15a. The cam gear 11a provided inside the mode control device 11 can drive the clutch lever 11b, and when the end of the clutch lever 11b falls into the recess A1 of the cam gear 11a, the lever 1
The clutch gear 11c pressed by the tip of the 1b is urged by a spring (not shown) to float and can be meshed with the gear 15a of the capstan motor 15. At this time, the rotational power of the gear 11c is transmitted to the pulley of the preceding worm gear 800 via the belt 11d, and the sub motor 12 is stopped. As a result, the capstan motor 15 is used as the power source and the cassette loading is performed.
When the cassette loading is completed, the cassette position is detected by the detection switch.
Is supplied with a detection signal. Then, the mode control device 11
The clutch lever to activate the sub motor 12.
The end of 11b is made to escape from the recess A1 of the cam gear 11a.
As a result, the clutch gear 11c is pushed down against the spring, and the mesh with the gear 15a is released.

When the cassette loading is completed, the tape loading is started.

FIG. 4 shows the main member of the tape loading mechanism taken out and shown from the back side of the VTR chassis.

Inside the mode control device 11, a cam gear 11e that rotates coaxially with the previous cam gear 11a is provided, and this am gear 11e can rotate the tape loading lever 11f. The tooth portion of the rotating end portion of the tape loading lever 11f meshes with a gear 31 rotatably provided on the chassis. The gear 31 meshes with the gear 32. And a link mechanism driven by the gears 31 and 32
The sliders 33 and 34 can drive the sliders 35 and 36, respectively. The sliders 35 and 36 are guide grooves formed from the cassette mounting part of the chassis toward the cylinder periphery.
It is provided slidably along 37 and 38, and has a pole for pulling out the tape on the front side (cassette mounting side) of the chassis, and pulls out the tape by moving in the direction of the arrow in the drawing, Can be attached. When the tape is unloaded, the cam gear 11e is reversed to allow the sliders 35 and 36 to return to their original state (the state shown in the drawing).

As described above, according to this embodiment, at the time of cassette loading, the loading mechanism is driven by the power of the capstan motor 15 with an extra power, and in that case, the operation of the servo circuit of the capstan motor is switched to loading. The servo target value is set. The servo target can be set, for example, by switching the division ratio of the rotation detection pulse of the capstan motor and setting the motor drive voltage to keep 900 rpm, for example, according to the phase difference between the divided output and the reference pulse. Is.

[Effects of the Invention] As described above, according to the present invention, the cassette loading operation is always stable and can be obtained at a constant speed, the cassette can be mounted at an accurate position, and the operational reliability can be improved. .

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is an exploded perspective view showing a cassette loading mechanism, FIG. 3 is a perspective view showing a basic example of a power transmission mechanism for the cassette loading mechanism, and FIG. FIG. 6 is a perspective view showing a basic configuration of a tape loading mechanism. 11 …… Mode control device, 12 …… Sub motor, 13 …… Tape loading device, 14 …… Operation mode setting device, 15…
… Capstan motor, 16 …… Servo circuit, 17 …… Cassette loading device.

Claims (1)

(57) [Claims] 1. A cassette loading gear for driving the cassette holder is rotated by slotting the cassette into a cassette holder at a receiving position to convey the cassette together with the holder to a predetermined mounting position, and eject operation. In response to the above, in a video tape recorder equipped with a loading mechanism for returning the cassette and the cassette holder to the receiving position, the rotation of the capstan motor used for driving the tape is responded to the slot-in and eject operations of the cassette. And a clutch gear mechanism that controls the loading and unloading operations by transmitting the rotation of the capstan motor to the cassette loading gear. Constant speed cassette loading apparatus characterized by comprising a servo means for loading for controlling the rotational speed of said capstan motor so as to maintain the rotational speed constant.