JPH02210684A - Cooling mechanism in magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To dissolve a high humidity or bedewing state and to reduce power consumption by controlling a discharge mechanism which detects humidity in a device and discharges the air in the inside of the device. CONSTITUTION:An insertion opening 11 to load a cassette 10 on a mechanical part 2 is provided on the front upper part of the device 1, and the opening is closed by a door 8 ordinarily. The door 8 is pushed and opened to the inside by the cassette 10 in inserting the cassette 10, and automatically closed after the insertion of the cassette 10 is completed. Also, an air intake part 9 is provided on the front lower part of the device 1. Furthermore, an air discharge opening 12 is provided on the back plane of the device 1, and the air in the inside of the device 1 is discharged by a cooling fan 7 driven rotatably with a motor 6. The system of a cooling mechanism is provided with plural temperature detectors 13, 14, 17 and humidity detectors 15 and 16, and controls the driving circuit 19 of the motor 6 by fetching the signals of those detectors in a microcomputer 18 and detecting the humidity of the inside of the device 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic recording/reproducing device, and particularly to a cooling mechanism suitable for preventing dew condensation.

[Conventional technology]

The current mainstream of magnetic recording and reproducing devices is the helical scan method, in which a tape is wound around a drum equipped with a rotating helide over a wide angle of 180 degrees or more. Further, a fixed head for recording or reproducing signals on a linear track is also wrapped with tape over a predetermined angle. These drums and fixed heads have a large contact area with the tape, so under high temperature conditions or condensation conditions,
The coefficient of friction with the tape becomes very large, and the tape is likely to be damaged due to an increase in the running load on the tape.

Especially as tapes have become thinner and less rigid in recent years.

This trend is growing.

For this purpose, magnetic recording and reproducing devices are equipped with a mechanism that detects the state of dew condensation or humidity inside the device. When high humidity or dew condensation is detected, the built-in heater is energized or the device is put into a stop mode, thereby reducing the humidity. As this type of device, for example, Japanese Patent Laid-Open No. 49-24407, Japanese Patent Laid-Open No. 49-2831
2, JP-A-49-53008, and the like.

[Problem to be solved by the invention]

Although the above-mentioned conventional technology can eliminate high humidity or dew condensation and prevent damage to the tape, no consideration was given to power consumption. That is, since a dedicated heater is installed to eliminate high temperature or dew condensation, there is a problem in that extra power consumption is required to operate the heater.

SUMMARY OF THE INVENTION An object of the present invention is to provide a cooling mechanism that eliminates the disadvantages of the prior art described above and can eliminate high temperatures or dew condensation while reducing power consumption.

[Means to solve the problem]

Normally, a commercial VTR has a cooling mechanism for discharging the amount of heat generated and trapped inside the device to the outside because the power consumption of circuits, power supplies, motors, etc. is large.

Therefore, the above object is achieved by controlling the operation of the cooling mechanism and utilizing the amount of heat generated inside the device to eliminate the high humidity or dew condensation state.

[Effect]

The humidity inside the device is detected by a detector, and if the humidity is higher than a predetermined value, the operation of the cooling mechanism is stopped. Then, the temperature inside the apparatus increases due to the amount of heat generated from one power supply circuit or the motor within the apparatus, and the relative humidity decreases. Therefore, the coefficient of friction between the tape and the guide member does not become abnormally large.

In addition, the humidity detector detects at an early stage when the humidity inside the device is about to rise, and weakens the operation of the cooling mechanism at a humidity lower than that which would increase the friction coefficient between the tape and the guide member. In other words, reduce the rotation speed of the cooling fan. This reduces the amount of air flowing into the device, and also ensures a certain degree of cooling effect for the heat source within the device.

〔Example〕

An embodiment of the present invention will be described in detail below.

FIG. 2 is a sectional view of the device 1. Mechanical part 2 is inside R1.
9 circuit boards 3 and 4. IT Source 5 Cooling fan 6 Fan 7. A motor 6 for driving a cooling fan is arranged as shown in the figure.

An insertion opening 11 for attaching a cassette 1o to the mechanical section 2 is provided at the upper front of the apparatus 1, and is normally closed by a door 8.

This door 8 opens the cassette 10 when the cassette 10 is inserted.
When the insertion of the cassette] and 0 is completed, it is automatically closed and does not accept the insertion of the primary cassette.6 Also, an air intake port 9 is provided at the lower front of the device It will be done.

Further, an air exhaust port 12 is provided on the back side of the device 1, and the air inside the device 1 is discharged by a cooling fan 7 rotated by a motor 6. A power source 5 located within the device 1
2 circuit boards 3 and 4. Various motors installed in the mechanical section 2 generate a large amount of heat, and overheating is prevented by exhausting air by the cooling fan 7. By discharging this air, surrounding air flows into the device 1 through the gap between the air intake port 9 and the door 8 on the front side of the device 1. This provides a cooling effect within the device 1.

However, conversely, if the surrounding humidity is high, for example, dew condensation will occur on the tape guide surface within the device 1. This is caused not only by the above-described air discharge, but also by air flowing into the interior when the door 8 is opened when the cassette 10 is inserted, causing dew condensation.

FIG. 1 is a diagram showing the system of the cooling mechanism.

A plurality of temperature sensors 13, 14 and 17 and a humidity sensor 1
5 and 16. These signals are sent to the microcontroller 18
The drive circuit 19 of the motor 6 is controlled by detecting the humidity inside the device 1.

Next, FIGS. 3 and 4 show their specific configurations. FIG. 3 shows the case where a temperature sensor is used. Signals from the temperature detectors 13 and 14 are input to the relative humidity detection circuit 2o, and the relative humidity inside the device 1 is detected. For example, the temperature detector 13 measures the temperature around the device 1, and the temperature detector 14 measures the internal temperature. Furthermore, the temperature sensor 14
If you measure the internal temperature near the air intake 9 or the door 8, the temperature in this area is normally the lowest inside the device 1, so you can quickly identify high humidity or dew condensation. can do.

Further, the temperature detectors 13 and 14 may be installed at appropriate locations in the device to detect the humidity inside the device due to the air flowing in. is compared with a predetermined reference value 22. If the relative humidity is lower than the reference value 22, turn on the power to the drive circuit 19.
1) Rotate the fan and perform normal exhaust operation. Furthermore, detection of the relative humidity within the device 1 is continued.

Further, if the detected value by the relative humidity detection circuit 20 is higher than the reference value 23, the drive circuit 19 is powered off, the rotation of the fan is stopped, and the exhaust operation is not performed. Therefore, there is no ambient air flowing into the device 1, and high temperature or dew condensation does not occur. However, if exhaustion by the fan 7 is stopped, the internal temperature and the temperature of the heating element itself will rise due to heat generation from the heating element within the device 1. Therefore, the temperature of the heating element is detected by the temperature detection circuit 23 based on information from the temperature detector 17 attached to the heating element (two power supply circuits, a motor, etc.). This detected value is sent to the comparator 24.
It is compared with a predetermined reference value 25 by . If this detected value is lower than the reference value 25, the fan 7 stops rotating and the relative humidity detection circuit 20 continues detection.

However, if the detected value is higher than the reference value 25, the comparator 26 further compares it with a predetermined reference value 27. This reference value 27 is a value higher than the reference value 25, and is preferably a temperature for ensuring the operational performance or lifespan of the heating element, for example.If the above-mentioned detected value is lower than this reference value 27, The drive circuit 19 is powered on, the fan 7 is rotated, and the exhaust operation is resumed. Then, the inflow of air from the surrounding area will resume, so the detection by the relative humidity detection circuit 20 will continue. On the other hand, if the above-mentioned detected value is higher than the reference value 27, the alarm display circuit 2
8, an alarm is displayed to inform the operator that the temperature of the heating element has become too high, and the drive circuit 19 is turned on. At this time, even if the main body of the device is in the middle of some operation, the operation will not be automatically stopped. For example, in the case of broadcasting, etc., it would be extremely troublesome if the system were to stop automatically, so we will leave the decision-making from this point on to the operator.

As yet another method, the reference value 22 to be compared with the comparator 21
There is a method of giving a predetermined range to the range, and responding differently when there is a detected value within this range.

At this time, the voltage or current level supplied from the drive circuit 19 to the motor 6 is lowered so that the motor 6 rotates at a lower rotation speed than usual. Due to this.

Since the exhaust air from inside the device 1 and the inflow from the surroundings occur gradually, and a slight cooling effect is obtained for the internal heating element, it is possible to reduce the degree of sudden temperature changes inside the device 1. As a result, high humidity or dew condensation inside the device can be smoothly avoided. Note that the reference value described above is further subdivided, and the drive circuit 19 is
It is also possible to more stably prevent high humidity or dew condensation by precisely controlling the amount of water.

FIG. 4 is a block diagram when a humidity detector is used. Components with the same functions as those shown in FIG. 3 are designated by the same numbers. First, humidity is detected by the humidity detection circuit 29 based on a signal from the humidity detector 15. It is preferable that this humidity detector 15 be installed in the same position as the temperature detector 13 described above so that it can touch the air around the device 1 as soon as possible to detect humidity. This humidity detection circuit 29
The detected value is compared with a predetermined reference value 31 by a comparator 30. The calling circuit ahead of this 19. Temperature detection circuit 23.
Comparators 24 and 26. The operation of the alarm display circuit 28 is the same as that described with reference to FIG. 3, so a description thereof will be omitted here.

Next, another embodiment will be explained with reference to FIG.

The value detected by the temperature detection circuit 23 is converted to a reference value 25 by the comparator 24.
If the detected value is lower than that shown in FIG. 3, the humidity detection circuit 29 may continue detecting humidity as shown in FIG. 3, but another method is also possible. As shown in FIG. 4, humidity is detected by a humidity detection circuit 32 based on a signal from a humidity detector 16 different from the humidity detector 15. The magnitude of the detected value of the humidity detector 32 and the detected value of the humidity detector 29 are inputted into a size comparator 30 and compared with the reference value 31.

For example, unlike the humidity detector 15, the humidity detector 16 is installed at the back of the mechanical section 2, that is, near the drum. In this way, even if the detected value from the humidity detection circuit 29 that originally detected the high temperature falls below the reference value 31, the high temperature state due to the humidity flowing into the interior of the device 1 with a delay will be detected. This can be detected by the circuit 32. Thereby, release of the high humidity state can be detected more safely.

〔Effect of the invention〕

According to the present invention, since dew condensation and high temperature conditions can be avoided by using the internal heat generation amount without providing a dedicated heater or the like, it is possible to reduce the power consumption and cost of the device. Furthermore, since local heating is not performed by a heater or the like, deterioration in accuracy due to thermal deformation of mechanical parts can be reduced, and tape running/scanning performance can be maintained with high accuracy.

[Brief explanation of the drawing]

FIG. 1 is a system configuration diagram of an embodiment of the present invention. FIG. 2 is a sectional view of the entire device, and FIGS. 3 and 4 are block diagrams of the cooling mechanism. 1... device. 2...Mechanical part. 6...Motor. 7...Fan. 10...cassette. 13.14,17...Temperature detector. 15.16...Humidity detector. 19... Drive circuit. Representative Patent Attorney Katsuo Ogawa, Mi

Claims (1)

[Scope of Claims] 1. A magnetic head scanning mechanism that sends and receives signals by scanning a magnetic tape with a magnetic head, a tape drive mechanism that runs the magnetic tape in a predetermined direction at a predetermined speed, and a system that includes these mechanisms. A magnetic recording/reproducing device equipped with a circuit that performs control and signal processing, and an exhaust mechanism that exhausts air inside the device, includes a humidity detection device that detects the humidity inside the device, and a signal from the humidity detection device that detects the above. 1. A cooling mechanism in a magnetic recording/reproducing device, characterized by comprising a means for controlling an ejection mechanism. 2. A magnetic head scanning mechanism that sends and receives signals by scanning the magnetic tape with a magnetic head, a tape drive mechanism that runs the magnetic tape in a predetermined direction at a predetermined speed, and a tape drive mechanism that controls these mechanisms and performs signal processing. A magnetic recording/reproducing device is equipped with a circuit for detecting the temperature and a discharge mechanism for discharging air inside the device, and a temperature detection device for detecting the temperature outside or inside the device; 1. A cooling mechanism in a magnetic recording/reproducing device, comprising: a means for controlling. 3. The above-mentioned temperature detection device is configured to include a temperature detection mechanism that detects the temperature of a heating element inside the device. A cooling mechanism in a magnetic recording/reproducing device according to claim 2.