JPH07105087B2 - Dew condensation detector for rotary head type tape recorder - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape drive in the field of rotary head type tape recorders, such as battery-powered type, which have recently been popularized, for example, portable video tape recorders and digital audio tape recorders (DAT). The present invention relates to a dew condensation detecting device provided for protecting a tape at the time of dew condensation of the device.

2. Description of the Related Art Recently, a video tape recorder having a rotary head and a DA
So-called rotary head type tape recorders such as T (Digital Audio Tape Recorder) are widely used. In these devices, a tape is wound around a cylinder, and by rotating the cylinder, a signal recorded on the tape is reproduced through a head attached to the cylinder, and conversely, a signal is recorded on the tape. However, in such a method of winding the tape around the cylinder, dew adheres to the portion of the cylinder or the capstan that is the tape drive device that directly contacts the tape surface, and when the tape is in a so-called dew condensation state, the tape is not transferred to the cylinder or the cap. If it sticks to the stun shaft, etc., the tape may be damaged or the head attached to the cylinder may be damaged. In order to prevent such a situation, the dew condensation detecting device is used to protect the tape and the head as shown in FIG.

The principle will be briefly described below with reference to FIG. When a tape is normally driven by a video tape recorder or a DAT, for example, a rotation command is given to the microcomputer 3 by the switch 2 and the cylinder motor 5 and the capstan motor are further supplied by the microcomputer 3.
6, each motor of the reel drive motor 7 is rotated by the output of the drive command to the motor drive circuit 4 of each motor. At this time, the output of the dew condensation detecting means 1 is L (LOW level) when the dew condensation is not detected, and if the dew condensation state is detected, the microcomputer 3 is set to H (HIGH level).
Gives the output of.

When the microcomputer 3 receives the output of H, it gives a stop command to the motor drive circuit 4 so that the tape does not stick to the cylinder, the capstan, or the like.

At the same time, a display command signal is given to the dew condensation display means 8. Then, LED9 lights up, and the user is informed as a warning that the tape recorder is in the state of dew condensation.

Depending on the device, other than the LED, this warning may be output as a sound, and even if the dew condensation detector detects the dew condensation state, only the warning display or the sound of the warning is generated and each motor remains driven. is there.

Problems to be Solved by the Invention Nowadays, video tape recorders and digital audio tape recorders of a type capable of recording or recording in the field have become widespread, but since those devices use batteries as a power source. A major issue is how to reduce battery consumption and how long recording or recording time can be maintained.

On the other hand, these devices are often used for outdoor recording even in low temperatures such as in winter, and often the tape is immediately reproduced after recording to check the recording result when brought into the room. At this time, dew condensation may occur inside the equipment due to the temperature difference between the outdoors and the room. In such a case, the above-mentioned dew condensation detecting means 1 detects the dew condensation state, stops the motor, and simultaneously operates the heater to early release the dew condensation. However, under such a condition, the device power remains on, so the heater current flows in addition to the internal circuit current of the set, and battery consumption is large in battery-operated tape recorders, etc. The battery life is often exhausted immediately after is released. Therefore, some devices do not have a heater.

However, a device without a heater naturally requires an extended time for releasing the dew condensation state.

The present invention has been made in view of such conventional problems, and an technical object thereof is to quickly release the dew condensation state and simultaneously reduce power consumption.

Means for Solving the Problems The present invention provides a motor drive circuit means for rotating a tape, a dew condensation detecting means for detecting a dew condensation state of a tape traveling mechanism system, and a stop command to the motor drive circuit by the output of the dew condensation detecting means. In a tape recorder having a microcomputer, a dew condensation display unit for displaying a dew condensation state by a detection output of the dew condensation detection unit, and a heater driving device for driving a heater by the dew condensation detection output, the dew condensation detection unit, the microcomputer, a motor A first energizing unit that energizes the drive circuit unit and the signal recording / reproducing circuit unit and stops energization when dew condensation is detected by the dew condensation detecting unit; and the dew condensation detecting unit and dew condensation display driven when dew condensation is detected by the dew condensation detecting unit. Means and second energizing means for energizing the heater driving device. It is characterized in that.

According to the present invention having such a feature, during the normal operation, the motor drive circuit means, the dew condensation detecting means, the microcomputer and the signal recording / reproducing circuit means are energized by the first energizing means, and the dew condensation detecting means causes dew condensation. If is detected, the energization of the first energizing means is stopped, and the second energizing means energizes the dew condensation detecting means, the dew condensation indicating means and the heater driving device so that the dew condensation can be eliminated. When the dew condensation is eliminated, the energization by the second energizing means is also stopped.

Embodiment An embodiment according to the present invention is shown in FIG. 1, and a time chart of its circuit operation is shown in FIG.

The present embodiment will be described below with reference to these figures. Reference numeral 1 is a dew condensation detecting means for detecting a dew condensation state of the device, and is usually provided on a tape driving mechanism in order to prevent the tape from being wound around a cylinder, a capstan or the like. Reference numeral 2 is a command switch to the microcomputer, 3 is a microcomputer for controlling the motor and the first energizing means, 4 is a motor drive circuit, 5 is, for example, a cylinder drive motor, 6 is a capstan drive motor, and 7 is a reel. A motor for driving, 8 is a dew condensation display means for driving the LED 9 for dew condensation display by an output from the dew condensation detection means 1, 10 is an output from the dew condensation detection means 1, for driving a heater to quickly dry the dew condensation state. It is a heater driving device. Further, 11 is a cylinder, 12 is a head attached to the cylinder 11 for taking out a signal from the tape or recording a signal on the tape, and 13 is an input / output circuit means 21 for converting a digital signal from the head 12 into an analog signal.
D / A conversion circuit means for outputting from the above, 14 is the above-mentioned microcomputer 3, motor drive circuit means 4, D / A conversion means, and first energizing means for supplying power to the dew condensation detecting means 1 at the normal time, 15 is a dew condensation display means 8 and a heater driving device
Also, a second energizing means for supplying power to the dew condensation detecting means 1 when the power supply from the first energizing means 14 is stopped after the dew condensation is detected, and 16 is a battery for the power source of the tape recorder. 17, 18 are the first and second energizing means 14, respectively.
It is a backflow prevention diode that blocks the flow of current into each other when power is supplied from 15. 19 is a power switch at the base of the tape recorder, 20 is an A / D for converting an analog signal input by the input / output circuit means 21 into a digital signal and sending it to the head 12 as a recording signal.
Conversion circuit means, 21 is an input / output circuit means, 12, 13, 20, 2
Reference numeral 1 constitutes a signal recording / reproducing circuit means.

Next, the operation of this embodiment will be described with reference to the timing chart of FIG.

When the tape is normally driven, the output of the dew condensation detecting means 1 is L as shown in FIG. Therefore, power is supplied from the first energizing means 14 to the dew condensation detecting means 1, the microcomputer 3, the motor drive circuit means 4, the D / A conversion circuit means 13, the A / D conversion circuit means 20 and the input / output circuit means 21. And
Cylinder motor 5, capstan motor 6, reel motor 7
The tape is driven by, and at the time of reproduction, the reproduction output is taken out by the head 12, passes through the D / A conversion circuit means 13, and is output as an analog signal by the input / output circuit means 21. During recording, the signal input to the input / output circuit means 21 is A / D.
It is recorded on the tape by the head 12 through the conversion circuit means 20.

Now, when the dew condensation detecting means 1 detects the dew condensation state, the output of the dew condensation detecting means 1 becomes H as shown in FIG. 2 (a).
When this is input to the microcomputer 3, a command to stop the motors 5, 6 and 7 is output from the microcomputer 3 to the motor drive circuit means 4, so that FIG.
The output of the motor drive circuit 4 is the dew condensation detecting means 1 as shown in FIG.
The output changes from H to H after τ ₁ hour.
From H to L after tau ₂ hours simultaneously become the output of the motor drive circuit 4 as shown in Figure 2 from the microcomputer 3 out stop command to the first energizing means 14 (c) is the L . Therefore, the power supplied to the dew condensation detection means 1 through the diode 17, the power supply to the microcomputer 3, the power supply to the motor drive circuit means 4, the D / A conversion circuit means 13, the A / D conversion circuit means 20, the input / output. The power supply to the circuit means 21 is stopped. On the other hand, the other output of the dew condensation detecting means 1 gives an operation command to the second energizing means 15 and at the same time gives an operation command to the dew condensation display means 8 and the heater driving device 10 as shown in FIG. ) As shown in the second
The energization output of L changes from H to H, and the LED 9 is turned on by the dew condensation display means 8 described above. At the same time, the heater driving device 10 is energized to raise the temperature by the heater so as to dry the dew condensation state.

Next, as shown in FIG. 2 (a), the output of the dew condensation detection means is H.
After ₁ hour, when the dew condensation state is released by the heater or the like and the output of the dew condensation detecting means 1 becomes L, τ
After ₃ hours, as shown in FIG.
Also stops output. The user knows that dew condensation has been released by turning off the LED 9 for dew condensation display. To turn the tape recorder back on, press the power switch on the tape recorder.
By turning 19 on again, the set becomes active again.

EFFECTS OF THE INVENTION According to the present invention having the above characteristics, the microcomputer device, the motor drive circuit, D
The power to the A / A converter circuit, A / D converter circuit, input / output circuit means, etc. is stopped, and the power consumption of the tape recorder is greatly reduced. It indicates to the user that it is in a dew condensation state. Therefore, it is possible to quickly release the dew condensation state by the heater, and to quickly release the dew condensation state with a small current consumption.

[Brief description of drawings]

FIG. 1 is a block diagram showing a dew condensation detecting device for a rotary head type tape recorder according to an embodiment of the present invention, FIG. 2 is a time chart showing its operation, and FIG. 3 is a block showing an example of a conventional dew condensation detecting device. It is a figure. 1 ... Dew condensation detecting means, 2 ... Switch, 3 ... Microcomputer, 4 ... Motor driving circuit means, 5,6,7 ...
Motor, 8 ... condensation display means, 9 ... LED, 10 ... heater drive device.

Claims (1)

[Claims] 1. A motor driving circuit means for rotating a tape, a dew condensation detecting means for detecting a dew condensation state of a tape running mechanism system, and a microcomputer for giving a stop command to the motor driving circuit means by an output of the dew condensation detecting means. A tape recorder having a dew condensation display unit for displaying a dew condensation state by a detection output of the dew condensation detection unit and a heater driving device for driving a heater by a dew condensation detection output, wherein the dew condensation detection unit, the microcomputer, and a motor drive circuit unit And a first energizing means for energizing the signal recording / reproducing circuit means and stopping energization when the dew condensation is detected by the dew condensation detecting means; A second energizing means for energizing the heater driving device. Dew detection of a rotary head type tape recorder to.