JPS6223361B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a tape recorder that can automatically adjust recording bias current, recording level, recording equalizer, etc. suitable for tape characteristics.
The present invention relates to a control device that prevents the above adjustment from being canceled by mistake.

Each of the above-mentioned adjustments is performed automatically in accordance with the characteristics of the tape by loading the tape into a tape recorder and operating an automatic adjustment switch. is stored until it is removed from the tape recorder. Therefore, the tape-appropriate adjustment state must not be canceled during tape recording, tape playback, or during fast-forward, rewind, and pause states.

Incidentally, this type of tape recorder is provided with a data reset switch for canceling the above-mentioned adjustment, but if the switch is operated by mistake during the above-mentioned operating state, the above-mentioned adjustment state will be canceled, which is an inconvenience. It was hot.

This invention was made in view of the above points,
The object of the present invention is to provide a control device for a tape recorder which prevents various adjustment states from being canceled even if a data reset switch is operated when the tape recorder is at least in a non-stop state.

Next, one embodiment of the present invention will be described with reference to the drawings.

S ₁ is a place switch S ₁₁ that is closed in the recording or playback state, a switch S ₁₂ that is closed in the fast forward state, a switch S ₁₃ that is closed in the rewind state, and a switch S ₁₄ that is closed in the pause state. S ₂ is a data reset switch for canceling the automatically adjusted recording bias current, recording level, recording equalizer, etc., S ₃ is an auto switch for starting the above automatic adjustment, 1 is an operation switch consisting of When the auto switch _S3 is closed, a drive signal is sent to the mechanism 2 to put the tape recorder into the recording state, and a variable bias circuit is also used to set the recording bias current, recording level, and recording equalizer to suit the characteristics of the tape. 3. The automatic adjustment circuit controls the level variable circuit 4 and the equalizer variable circuit 5, and when a high level signal is input to the reset terminal 1a, the above adjustment is canceled.

Q ₁ is a first switching transistor that is turned on when the operating switch S ₁ is closed, Q ₂ is a second transistor that is turned off whenever the transistor Q ₁ is on, and RC is a transistor Q ₁ .
The resistor and capacitor constitute a time constant circuit that turns on transistor _Q2 for a certain period of time when data reset switch _S2 is closed while Q2 is off. Note that _R1 is a discharge resistance.

Next, to explain the operation based on the above circuit, when you operate one of the operation switches _S1 to drive the tape recorder, the base of the transistor _Q1 becomes ground potential due to the closing of the empty switch. , the transistor _Q1 is turned on, so its collector is at a high level. As a result, the base potential of transistor Q ₂ becomes high, so that transistor Q ₂ maintains an off state.

Even if the data reset switch _S2 is closed, the base potential of the transistor _Q2 does not drop, so the transistor _Q2 is not turned on.Therefore, no reset signal is applied to the reset terminal 1a of the automatic adjustment circuit 1, and various The adjustment will never be canceled.

Next, when the operation switch _S1 is not operated, that is, the tape recorder is in the stopped state,
Transistor _Q1 is in the off state. When the data reset switch _S2 is closed, the base current of the transistor _Q2 flows only between the time constant circuit (approximately 10 msec) of the resistor R and the capacitor C, so that the transistor _Q2 is turned on. As a result, a positive pulse signal is applied to the reset terminal 1a of the automatic adjustment circuit 1, so the various adjustment memories of the automatic adjustment circuit 1 are canceled, and the variable circuits 3 to 5 of the recording bias current, recording level, and recording equalizer are It is reset to a predetermined standard value.

As described above, in this invention, even if the data reset switch for canceling the data in the automatic adjustment circuit is operated while the tape recorder is in operation, the data memory is not canceled. Even if the data reset switch is operated by mistake, the adjustment will not be canceled.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of a control circuit for a tape recorder according to the present invention. _S1 ...operation switch, _S2 ...data reset switch, 1...automatic adjustment circuit, _Q1 , _Q2 ...switching transistor.

Claims (1)

[Claims] 1. In a tape recorder equipped with an automatic adjustment circuit that automatically adjusts and stores recording bias current, recording level, recording equalizer, etc., at least one of the operation switches of the tape recorder is closed. a data reset switch for canceling the adjustment; and a control means for detecting that the data reset switch has been operated and resetting the automatic adjustment circuit; A control device for a tape recorder, characterized in that the reset operation of the control means is prohibited by the output of the detection means.