JPH06180890A - Dew condensation preventing device for magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To prevent the dew condensation and to prevent a malfunction and the breaking by detecting the change in temperature and humidity by a sensor, unloading a magnetic tape, rotating a head drum at high speed and heating the inside of the drum by a heater. CONSTITUTION:The change in temperature is converted to an electric signal by a temperature senser 1 and a converter circuit 3, and further the change in humidity is converted to the electric signal by a humidity senser 2 and the converter circuit 4 to be inputted to a micro processor 5. In the processor 5, data inputted from the sensors 1, 2 are subjected to arithmetic processing and the changes in temperature and humidity within a fixed time are coded to the data. The data compared with the data for predicting the dew condensation stored in the processor 5 previously, and a control signal is sent to a loading mechanism 8 when a condition where the dew condensation is going to occur occurs to unload the magnetic tape 9. Further, the heater 6 is operated, and the head drum 7 is rotated at high speed while being heated with the head drum 7. Thus, the dew condensation on the drum 7 is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary head type magnetic recording / reproducing apparatus, and more particularly to a magnetic recording / reproducing apparatus having a function of preventing dew condensation.

[0002]

2. Description of the Related Art Regarding the prevention of dew condensation in a conventional rotary head type magnetic recording device, a dew condensation sensor is provided inside a magnetic recording / reproducing device as described in, for example, Japanese Utility Model Publication No. 2-29527, and a head drum is formed by the dew condensation sensor. The dew condensation is detected, the motor is stopped and the head drum is warmed to remove the dew condensation, and all the functions of the magnetic recording / reproducing device are detected for a certain period of time (until the dew condensation disappears).
There were things such as stopping to prevent the tape from being wound up due to dew condensation.

[0003]

All of the conventional methods deal with the occurrence of dew condensation, and the tape and the head drum are in contact with each other during the period from the dew condensation to the dew condensation removing operation. Therefore, it was not perfect in terms of tape protection.

An object of the present invention is to prevent dew condensation inside the magnetic recording / reproducing apparatus (particularly the head drum) in advance, and prevent winding of a tape.

[0005]

In order to achieve the above object, in the present invention, a magnetic recording / reproducing apparatus is provided with a temperature sensor, a humidity sensor and a heater.

[0006]

[Function] As the temperature sensor, a thermistor (electric resistance changes with temperature) is used. As the humidity sensor, a metal oxide humidity sensor for detecting dew condensation (electric resistance changes due to moisture absorption), which is very commonly used in a magnetic recording / reproducing apparatus, is used.

The output of these sensors is converted into an electric signal and then input to a microprocessor, and by comparing the temperature change and humidity change within a certain time by arithmetic processing with the internal data, the magnetic recording / reproducing apparatus is in a condition where dew condensation is likely to occur. In this case, the mechanical operation of the heater and the magnetic recording / reproducing device is controlled.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.

FIG. 1 is a circuit block of a VTR integrated camera as an example.

The case where the temperature and humidity change due to the movement of the photographer during photographing with the VTR integrated camera will be described.

A temperature sensor 1 and a conversion circuit 3 provided in a VTR integrated camera convert a change in temperature into an electric signal and input temperature information to a microprocessor 5. The humidity sensor 2 and the conversion circuit 4 convert the change in humidity into an electric signal and input the humidity information to the microprocessor 5. In the microprocessor 5, the temperature sensor 1
And the data input from the humidity sensor 2 are processed to convert temperature and humidity changes within a fixed time into data, and this data is compared with the data for predicting condensation stored in the microprocessor 5 in advance to generate condensation. When the conditions are likely to occur (for example, when the temperature changes by 15 ° C. or more in the plus direction within 5 minutes at a humidity of 50% or more), a control signal is sent to the loading mechanism 8 to unload the magnetic tape 9. Further, the heater 6 is operated to warm the head drum 7 and rotate the head drum 7 at high speed. By performing the above operation for a certain period of time (for example, 10 minutes), the dew condensation on the head drum 7 can be prevented in advance.

Further, when the VTR integrated camera is in operation, the microprocessor 5 is provided with a backup function to operate the temperature sensor 1, the humidity sensor 2, the conversion circuit 3 and the conversion circuit 4 even when the camera is not in operation. It is possible to prevent dew condensation in the same way as.

[0013]

According to the present invention, dew condensation of the magnetic recording / reproducing apparatus can be prevented in advance, so that malfunction and damage of the magnetic recording / reproducing apparatus and damage of the magnetic tape due to winding of the magnetic tape can be prevented.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Temperature sensor, 2 ... Humidity sensor, 3 ... Conversion circuit, 4 ... Conversion circuit, 5 ... Microprocessor, 6 ... Heater, 7 ... Head drum, 8 ... Loading mechanism, 9 ... Magnetic tape, 10 ... Guide pin.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akihiko Maruyama 292 Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa Stock company Hitachi Image Information Systems (72) Inventor Takashi Sato 292 Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa Hitachi Image Information System (72) Kenji Mizoguchi Inventor Kenji Mizoguchi 292 Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa Stock Information Hitachi Image Information System

Claims (1)

[Claims] 1. A rotary head type magnetic recording / reproducing apparatus is provided with a temperature sensor, a humidity sensor and a heater to detect changes in temperature and humidity, so that the inside of the magnetic recording / reproducing apparatus is subject to dew condensation. Sometimes, the magnetic tape inserted in the magnetic recording / reproducing apparatus is unloaded, and the head drum is rotated at a high speed to heat the inside of the magnetic recording / reproducing apparatus by a heater to prevent dew condensation. Dew condensation prevention device for recording / playback devices.