JPH0744929A - Magnetic recording / reproducing device - Google Patents

Abstract

PURPOSE:To rapidly release dew condensation without hindering the reduction of the cost, size and weight by putting a rotary drum driving motor into an electrically locked state at the time of the dew condensation and heating the drum with the generated heat. CONSTITUTION:Information on a dew condensation state is transmitted to a system controller 12 when a dew condensation detecting circuit 11 detects the dew condensation state, and the system controller 12 switches over a switch 13 to a (b) side. As a result, a locking circuit 15 of the rotary drum driving motor 4 passes a prescribed current only to U, V of windings 5 of the motor 4 to pass the current to the motor 4 but to electrically lock the motor 4 without rotation, and the winding 5 generates heat. The heat generated by the winding 5 rapidly warms up the rotary drum and heats the stationary drum through bearings, too. The dew condensation state is thus released. The switch 13 is held on an (a) side and the driving circuit 14 of the motor 4 passes the prescribed current to the UVW of the winding 5 to rotate the drum at the time of ordinary tape traveling. As a result, the dew condensation is rapidly released.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing device.

[0002]

2. Description of the Related Art Conventionally, in this type of magnetic recording / reproducing apparatus, as a countermeasure for removing dew condensation that occurs when moving from a low temperature environment to a high temperature environment (for example, moving from outdoors to indoors in winter). As shown in FIG. 6, a heater 16 is provided in the vicinity of the outer circumference of the drum, and at the time of dew condensation, an electric current is passed through the heater to raise the surface temperature of the drum to release the dew condensation.

[0003]

In the above-mentioned conventional example, a heater and a member for mounting the heater must be added, which not only increases the number of parts and the manufacturing cost, but also increases the product cost. It was also an obstacle to miniaturization.

In recent camera integrated VTRs, due to demands for cost reduction, size reduction and weight reduction, the above-mentioned heaters have not been added, and the dew condensation is released by leaving them naturally. It cannot be used until. Therefore, it has a drawback that the product cannot be used for a long time as compared with the method of adding a heater.

[0005]

The present invention has been made in order to solve the above-mentioned problems, and is characterized in that a magnetic tape is wound around a rotary drum having a magnetic head to record and reproduce magnetic signals. In the magnetic recording / reproducing apparatus for performing the above, the rotary drum drive motor is locked to generate heat in its winding, thereby warming the rotary drum, the magnetic head, the fixed drum, the bearing, and the like, and having a mode for releasing dew condensation. And Further, the winding is provided on the rotary drum.

[0006]

【Example】

Example 1 An example of the present invention will be described with reference to the drawings. First, FIG. 1 is a sectional view of a drum showing an embodiment of the present invention. 2 is a block diagram showing an embodiment of the present invention, FIG.
1, 2 and 3, 1 is a magnetic head for recording / reproducing a magnetic signal, 2 is a rotating drum equipped with a magnetic head 1, and FIG. 3 is a magnetic tape, 4 is arranged coaxially with the rotary drum 2 in the vicinity of the rotary drum, and a rotary drum drive motor / stator for driving the rotary drum 5 is provided in the rotary drum drive motor / stator. Winding, 6
Is a rotary drum drive motor / rotor, 7 is a fixed drum, 8
Is a bearing with a shaft for enabling the rotary drum to rotate coaxially with the fixed drum, 9 is a fixed side rotary transformer included in the fixed drum, and 10 is opposed to the fixed side rotary transformer with a slight gap. It is the rotary transformer installed on the rotating side.

Next, FIG. 2 is a block diagram showing an embodiment of the present invention. Here, 11 is a dew condensation detection circuit, 12 is a system controller, 13 is a switch for switching driving / locking of the rotary drum drive motor, and 14 is a rotary drum drive motor drive circuit having a current pattern as shown in FIG. Reference numeral 15 is a rotary drum drive motor lock circuit for generating a current pattern as shown in FIG. FIG. 3 is a flow chart showing an embodiment of the present invention. In the flowchart shown in FIG. 3, when the dew condensation detection circuit 11 detects the dew condensation state in step S1, the information is transmitted to the syscon 12, the switch 13 is switched to the b side in step S2, and the winding 5 of the rotary drum drive motor is turned on. A current as shown in FIG. 5 is applied to each of (U, V, W), and a current flows through the rotary drum drive motor, but the motor does not rotate and becomes electrically locked and the winding 5
Heats up. Due to the heat generated by the winding 5, the rotary drum 2 arranged in the vicinity is quickly warmed and the dew condensation state is released. Further, the fixed drum 7 is also warmed by heat conduction or the like through the shaft bearing 8 to release the dew condensation state. During normal tape running, in accordance with the flowchart shown in FIG. 3, the switch 13 is connected to the side a in step S3, and the winding 5 (U, V, W) of the rotary drum drive motor has a structure shown in FIG.
A current flows as shown in, and the drum rotates. In the embodiment, the winding of the motor is provided on the stator side and the magnet is provided on the rotating drum side, but this may be reversed. In that case, the effect of preventing dew condensation due to heat generation of the winding is great.

[0008]

As described above, the rotary drum drive motor is electrically locked at the time of dew condensation, and the heat is generated to heat the drum, which does not hinder cost reduction, size reduction, and weight reduction. It became possible to quickly release the dew condensation.

[Brief description of drawings]

FIG. 1 is a sectional view of a drum according to an embodiment of the present invention.

FIG. 2 is a block diagram of an embodiment of the present invention.

FIG. 3 is a flowchart of an embodiment of the present invention.

FIG. 4 is a diagram showing a current pattern from a rotary drum drive motor drive circuit according to an embodiment of the present invention.

FIG. 5 is a diagram showing a current pattern from the rotary drum drive motor lock circuit according to the embodiment of the present invention.

FIG. 6 is an external view of a drum in a conventional example.

[Explanation of symbols]

 1 magnetic head 2 rotary drum 3 magnetic tape 4 stator part of rotary drum drive motor 5 winding of rotary drum drive motor 6 rotor part of rotary drum drive motor 7 fixed drum 8 bearing with shaft 9 fixed side rotary transformer 10 rotary side rotary transformer 11 Condensation Detection Circuit 12 Syscon 13 Switch 14 Rotary Drum Drive Motor Drive Circuit 15 Rotary Drum Drive Motor Lock Circuit 16 Heater

Claims (2)

[Claims] 1. A magnetic recording / reproducing apparatus for recording / reproducing a magnetic signal by winding a magnetic tape around a rotating drum equipped with a magnetic head to lock the rotating drum drive motor to heat its windings and release dew condensation. A magnetic recording / reproducing apparatus characterized by having a mode for controlling. 2. The magnetic recording / reproducing apparatus according to claim 1, wherein the winding of the motor is provided on a rotary drum.