JPS6139255A - Pinch roller carrier - Google Patents

Abstract

PURPOSE:To attain miniaturization of the titled device and low power consumption by using a laminated type electrostriction ceramic drive element as a drive source of a pinch roller. CONSTITUTION:When a voltage is applied to the laminated type electrostriction ceramic drive element 130 via an electronic circuit 80, the drive element 130 is expanded in the laminated direction, that is, toward arros 1, 2. Then a displacement expanding arm 100 is bent and a pinch roller support plate 35 is rotated around a shaft 40 against the tensile strength of a spring 90. As a result, the press contact between the capstan shaft 20 and the pinch roller 30 is released and the press contact between the magnetic tape 10 and the capstan shaft 20 is released. Further, the distance L of the pinch roller 30 to be detached from the capstan shaft 20 can be 100mum because the thickness of tape is nearly 20mum.

Description

[Detailed description of the invention] Industrial applications The present invention is applicable to video tape recorders (VTRs), etc.

The present invention relates to a pinch roller moving device in a magnetic recording/reproducing device.

2. Description of the Related Art Conventionally, in a VTR or the like, a capstan shaft and a pinch roller are used to drive a magnetic tape, and the magnetic tape is driven by sandwiching the magnetic tape between the two. On the other hand, when winding the magnetic tape around a rotating drum or during recording pause, the magnetic tape is not pressed onto the capstan shaft in order to prevent abrasion or damage to the magnetic surface of the magnetic tape. This structure is shown in Section 7.8.
As shown in the figure, the pinch roller is temporarily moved using a solenoid or the like as a driving source to release the pressure between the capstan shaft and the magnetic tape.

That is, FIG. 7 shows a conventional pinch roller moving device using a solenoid, in which a capstan shaft and a pinch roller sandwich and press a magnetic tape. . FIG. 8 shows a case where the capstan shaft and the pinch roller are released from pressure. As shown in FIG. 7, a pinch roller 30 is rotatably attached to one end of a pinch roller support plate 35 which is rotatably provided around a shaft 40. The pinch roller 30 pinches the magnetic tape 10 and the capstan shaft 20
is crimped to. Further, a link 50 connecting the support plate 35 and the solenoid 70 is attached to the other end of the pinch roller support plate 35 by a shaft 45. Because of this structure, as shown in Figure 8,
When the solenoid 70 is energized and the plunger 71 is pulled, the link 50 is also pulled, and the pinch roller support plate 35 rotates in the 30'' direction about the shaft 40.
is separated from the capstan shaft 20.

That is, the pressure bond between the magnetic tape 10 and the capstan shaft 20 is released, and the driving of the magnetic tape 10 is stopped.

Problems to be Solved by the Invention However, in the conventional structure, (1) the volume occupied by the driving source such as a solenoid is large, which prevents the device from becoming smaller.

(2) Large amount of power is consumed for driving due to poor electrical-mechanical conversion efficiency.

There are problems such as:

Means for Solving the Problems The present invention uses a laminated electrostrictive ceramic element as the drive source of the pinch roller, moves the pinch row 2 by driving the laminated electrostrictive ceramic element, and moves the pinch roller 2 between the magnetic tape and the capstan shaft. This is to release the crimp.

The laminated electrostrictive ceramic element expands in the lamination direction when a voltage is applied. Using this stretching force, the pinch row 2 can be moved away from the capstan. When the voltage is removed, the pinch roller can be restored and pressed against the capstan again.

Embodiment FIGS. 1 and 2 show an embodiment of the present invention, and show a state in which a pinch roller 30 and a capstan shaft 20 are pressed together with a magnetic tape 10 sandwiched between them, and an electrostrictive structure in a laminated structure, respectively. 7 is a diagram showing a state in which the pinch roller 30 and the capstan shaft 20 are released from pressure by driving the ceramic drive element 130. FIG. 5 and 6 are diagrams showing the external appearance and internal structure of the laminated electrostrictive ceramic drive element 130.

In this example, the drive source for rotating the pinch roller support plate 35 around the shaft 40 is a laminated electrostrictive ceramic drive element 130, which is made up of a large number of stacked thin-film electrostrictive ceramics and electrodes, as shown in FIG. 5.6. is adopted. That is, an electrostrictive ceramic drive element 130 is used in which thin film electrostrictive ceramics 131 and electrodes 132 are alternately laminated. This electrostrictive drive element has the following features.

(1) The force generated when a voltage is applied is a force.

(2) High electrical-mechanical conversion efficiency.

(3) Can be driven with a voltage of 50 to 100v.

Next, the structure and operation will be explained with reference to FIGS. 1 and 2. An electronic circuit 80 is connected to the laminated electrostrictive ceramic drive element 130. A stacked electrostrictive ceramic driving element 130 has a fixed plate 110 attached to one end thereof and a displacement magnifying arm 100 attached to the other end thereof.

The displacement magnifying arm 100 has a leaf spring 150 at one end thereof, and the other end of the leaf spring 150 is fixed to the fixing member 120. Further, the other end of the displacement magnifying arm 100 is in contact with a part of the pinch roller support plate 35. Therefore, when a voltage is applied to the laminated electrostrictive ceramic drive element 130 via the electronic circuit 80, the drive element 130 extends in the lamination direction, that is, in the direction of arrow 1.2. Then, the displacement magnifying arm 100 is bent and the pinch roller support plate 35 rotates around the shaft 40 against the tensile force of the spring 90. As a result, the pressure bond between the capstan shaft 20 and the pinch roller 30 is released. In other words, the pressure bond between the magnetic tape 10 and the capstan shaft 20 is released. Note that the distance between the pinch roller 30 and the capstan shaft 20 may be approximately 100 μm since the tape thickness is approximately 20 μm.

Figure 5.6 shows another embodiment of the invention. The difference between FIG. 5.6 and FIG. 1.2 is that the displacement magnifying arm 100 acts on the pinch roller support plate 35. In the case of Fig. 1.2, the point of action is located a predetermined distance closer to the axis 40 of the pinch roller support plate 35 toward the pinch roller 30, whereas in the case of Fig. 5.6, the point of action is It is located a predetermined distance away from the shaft 40 in the direction opposite to the pinch roller 30 direction.

In the case of FIG. 1.2 and FIG. 5.6, it was explained that the amount of displacement of the laminated electrostrictive ceramic drive element 130 is magnified by the displacement magnifying arm 100 and transmitted to the pinch roller support plate 35.
The point at which the displacement magnifying arm 100 acts on the pinch roller support plate 35 is appropriately selected, and the pinch roller 30 relative to the shaft 40 is
The amount of displacement of the laminated electrostrictive ceramic drive element 130 can also be expanded and transmitted to the pinch roller 30 by appropriately selecting the distance between the magnet and the distance to the point of action of the displacement magnifying arm 100.

Effects of the Invention As described above, according to the present invention, since the laminated electrostrictive ceramic drive element is used as the drive source of the pinch roller, the present invention has the following advantages.

(1) Since the laminated electrostrictive ceramic drive element generates a large force, the drive source can be downsized. In other words, the device can be made smaller.

(2) Since the electromechanical conversion efficiency of the laminated electrostrictive ceramic drive element is high, the power consumption of the device can be reduced.

[Brief explanation of drawings]

FIG. 1 is a diagram of the principle structure showing one embodiment of the present invention, FIG. 2 is a diagram of the principle structure in a different state from FIG. 1, and FIG. 3 is an external view of the laminated electrostrictive ceramic drive element of FIG. 1. 4 is a sectional view of FIG. 3, FIGS. 5 and 6 are pinch rollers, 90 is a cross-sectional view of FIG.
130 is a laminated electrostrictive ceramic drive element, 80 is a drive circuit, 100 is a displacement amplification transmission means, and 35 is a support plate.

Claims (3)

[Claims] (1) A capstan shaft and a pinch roller for driving the magnetic tape, a spring that presses the pinch roller onto the capstan shaft, and a laminated electric current that releases the pinch roller from the capstan. It has a strained ceramic drive element and its drive circuit, and the pinch roller is moved by driving the laminated electrostrictive ceramic drive element with the drive circuit, and the pinch roller and the capstan shaft are separated. Pinch roller moving device. (2) Displacement magnification transmission means is provided between the laminated electrostrictive ceramic drive element and the pinch roller to magnify the displacement of the laminated electrostrictive ceramic drive element and transmit it to the pinch roller. Characteristic claim 1
The pinch roller moving device described in . (3) One end of the pinch roller is rotatably supported by one end of a support plate that can move toward and away from the capstan axis, and the support plate is supported by the spring so that the pinch roller is pressed against the capstan shaft. and the laminated electrostrictive ceramic drive element drives the support plate so that the pinch roller moves away from the capstan shaft against the bias of the spring. The pinch roller moving device according to item 1.