JPH0525044Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a dictator (hereinafter also referred to as a dictator), and particularly to a dictator that can erase the beginning of a tape during high-speed erasing during rewinding.

(Prior Art) A conventional dictator will be described below with reference to FIG. 2 showing its main parts.

As shown in FIG. 2, the conventional dectator has a three-in-one head 3 in which a recording/playback head 1 and a first erasing head 2 are housed in the same shield case, and a predetermined distance from the three-in-one head 3. and a second, spaced apart erase head.

When a recording operation is performed on this dectator,
An AC erase current is supplied to the first erase head 2 from a bias oscillator (not shown). Also, a signal current is supplied to the recording/playback head. Then, the tape 5 stored in the tape cassette runs in the direction of arrow A in the figure, and a signal is recorded on the tape 5. At this time, no erase current is supplied to the second erase head 4.

Then, when a rewinding operation is performed, a DC erase current is supplied to the second erase head 4. The tape 5 is then rewound in the direction of arrow B in the figure, and the recorded contents of the tape 5 are erased at high speed by the second erasing head 4. At this time, no erase current is supplied to the first erase head 2.

(Problems to be Solved by the Invention) In the conventional dictator described above, the starting end a of the tape 5 shown in FIG. 2 travels in the direction of arrow A and passes over the three-in-one head 3 during recording. Therefore, by this three-in-one head 3, the starting end a
The signal is recorded. However, during rewinding, the starting edge a does not pass over the second erasing head 4, so the recorded content of the starting edge a remains unerased, posing a problem in terms of confidentiality.

(Means for Solving the Problems) Therefore, in order to solve the above problems, the present invention provides a first erasing head which is housed in the same shield case as the recording/playback head and is supplied with an alternating current erasing current during recording. A dictation recorder having a head and a second erasing head disposed at a predetermined distance from the first erasing head and to which a DC erasing current is supplied when rewinding the tape. A dictation recording device comprising an erasing current supply means for supplying an erasing current to the first erasing head and the second erasing head, and supplying an alternating current erasing current to the first erasing head during recording. It provides an opportunity for

(Example) The dictator according to the present invention will be explained in detail with reference to FIG. FIG. 1 is a diagram showing a main part of an embodiment of an erase current supply circuit provided in a dectator according to the present invention. Note that the same parts as in the conventional example are denoted by the same reference numerals, and a detailed explanation of the parts will be omitted.

First, the circuit configuration of the erase current supply circuit will be explained. The terminal 6 of the first erase head 2 is grounded to the collector of an NPN transistor _Q1 whose emitter is grounded. A bias voltage is supplied to the base of this transistor Q ₁ via a resistor R ₁ . Terminal 7 of erase head 2 is connected to the coil of bias oscillator 8.
Connected to _L1 . The terminal 9 of the second erasing head 4 is connected via a resistor R ₂ and the terminal 10 directly to the coil L ₁ . Also, terminal 9
is connected to the emitter of NPN transistor _Q2 . A resistor _R3 and a switch _S1 are connected in series between the base and collector of this transistor _Q2 .

Next, the circuit operation will be explained. When recording,
Due to the prescribed recording operation, transistor _Q1 turns on,
And since the bias oscillator 8 is in the ON state,
The first erase head 2 is supplied with an alternating current erase current. Transistor _Q2 is OFF because switch _S1 is opened by a predetermined recording operation. Therefore, no erase current is supplied to the second erase head 4. At this time, signals are recorded on the tape 5 by the three-in-one head 3.

Next, when rewinding, by a predetermined rewinding operation,
Since switch S ₁ is shorted, transistor Q ₂
is turned on, and a DC erase current is supplied to the second erase head 4. Further, due to the predetermined rewinding operation, the bias oscillator 8 is turned off and the transistor _Q1 is turned on, so that a DC erase current is supplied to the first erase head 2 via the second erase head 4.

As a result, when rewinding, the starting end a of the tape 5
The other recorded contents are first erased by the first erase head 2 and then erased by the second erase head 4. Therefore, since the same portion can be erased twice, more complete erasure can be achieved.

Furthermore, the starting end a of the tape 5 shown in FIG.
When rewinding, it does not pass over the second erasing head 4, but
It passes over the first erase head 2. Therefore, the recorded content at the starting end a can be erased by the first erasing head 2.

(Effects of the invention) As described above, the dictator according to the invention can erase the starting end of the tape at high speed during rewinding, and can also erase parts of the tape other than the starting end at double high speed using two erasing heads. Therefore, the effectiveness of confidentiality is improved.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a main part of an embodiment of an erasing current supply circuit provided in a dectator of the present invention, and FIG. 2 is a diagram showing a main part of a conventional dectator. 1... Recording/playback head, 2... First erasing head, 3... Three-in-one head, 4... Second erasing head, 5... Tape, 6, 7, 9, 10...
... terminal, 8 ... bias oscillator, C ₁ , C ₂ ... capacitor, L ₁ ... coil, Q ₁ , Q ₂ ... NPN transistor, R ₁ to R ₃ ... resistance, S ₁ ... switch.

Claims (1)

[Scope of claim for utility model registration] A first head that is housed in the same shield case as the recording/playback head and to which an AC erasing current is supplied during recording.
A dictation recorder comprising an erasing head and a second erasing head disposed at a predetermined distance from the first erasing head and to which a DC erasing current is supplied during tape rewinding, the dictation recorder comprising: supplying a DC erase current to the first erase head and the second erase head;
1. A dictation recorder comprising erasing current supply means for supplying an alternating current erasing current to the first erasing head during recording.