JPS6341629Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is a magnetic tape equipped with a positioning function that switches from fast-forwarding or rewinding to playback by detecting a no-signal area between signals recorded on the magnetic tape. Regarding recorders.

Conventionally, in a tape recorder equipped with such a positioning function, the user is informed that the positioning operation is in progress by making a loud sound emitted from the speaker or by causing the pointer of the level meter to wave with a signal. I was trying to make them aware. The former method of emitting sound from a speaker is audible, while the latter method of using a level meter needle not only cannot be displayed because the deflection of the pointer becomes small when the signal level is low, but also It has the disadvantage that the pointer oscillates, causing an unpleasant sensation.

The present invention aims to provide a display circuit that is improved in this respect, and will be described in detail below with reference to the drawings. The illustrated circuit is one embodiment of the display circuit of the present invention. In the figure, 1 is an input terminal to which a reproduction signal or recording signal derived from an amplifier circuit (not shown) is applied; 2 is an amplifier circuit for a peak indicator that amplifies the signal applied to the input terminal 1; Reference numerals 3, 4 and 5 are driving transistors which are turned on in response to the signal level from the peak indicator amplifier circuit 2, and to which light emitting diodes 6, 7 and 8 are connected as collector loads, respectively. Resistors 9, 10, 11, 12, connected to the base circuit of
13 and 14 serve to set the operating points of the drive transistors 3, 4 and 5.
15, the collector of which is the driving transistor 3;
4 and 5, the emitter is grounded, and the base is connected to the power supply via a resistor 16. When the control transistor is inverted to the on state, the driving transistors 3 and 4 are connected to each other. and 5 are enabled for operation. Reference numeral 17 denotes a first switch that is closed in stop, fast forward, and rewind states, and is opened in playback or recording states, and is connected between the base of the control transistor 15 and ground. Reference numeral 18 denotes a second switch that is closed during fast forwarding or rewinding operations.
is applied to the base of the transistors 3 and 4.
and 5 are all connected to turn on.

The present invention is constructed as described above, and its operation will be explained next. First, the operation as a peak indicator will be explained. The reproduction signal or recording signal applied to the input terminal 1 is amplified by the peak indicator amplifier circuit 2 and then applied to the bases of the driving transistors 3, 4 and 5. In the playback or recording state, the first switch 17 is open, so that a bias is applied to the base of the control transistor 15 through the resistor 16. Therefore, the driving transistors 3, 4 and 5 are inverted to the on state according to the level of the signal output from the peak indicator amplifier circuit 2, and the light emitting diodes 6, 7 and 8 are turned on, respectively.
Drive the light on. Therefore, the user can recognize the peak level of the playback signal or recording signal by lighting the light emitting diodes 6, 7, and 8.

The peak indicator operates as described above, but in the stop, fast forward, or rewind state, the first switch 17 is closed and the control transistor 15 is in the off state. 6, 7, and 8 are never driven to light up.

Next, a case in which a positioning operation is performed will be explained. Such a positioning operation is performed by simultaneously pressing the playback button and the fast forward or rewind button, so the first switch 17 is opened and the second switch 17 is opened.
Switch 18 will be closed. As a result, the control transistor 15 is biased through the resistor 16 and the drive transistors 3, 4
and 5 are biased into the on state by a high voltage applied through the second switch 18.
Therefore, in such a positioning operating state, all the light emitting diodes 6, 7 and 8 will light up with a constant brightness, indicating that the tape recorder is in the positioning operating state.

In the present embodiment, a case has been described in which three light emitting diodes are used as indicators, but the number is not limited to this, and display can be performed as long as there is at least one light emitting diode. Further, although a light emitting diode is used as a display element, it is of course possible to use a light emitting element such as a lamp.

As explained above, the present invention is designed to indicate that the tape recorder is in the positioning operation state by lighting up the display element that displays the peak level of the playback signal or recording signal. This has the advantage of not only being able to display images without causing discomfort to the user, but also simplifying the circuit configuration.

[Brief explanation of drawings]

The illustrated circuit is one embodiment of the display circuit of the present invention. Explanation of main figure numbers, 2...Peak indicator amplifier circuit, 3, 4, 5...Drive transistor, 6, 7, 8...Light emitting diode, 15...
Control transistor, 17...first switch,
18...Second switch.

Claims (1)

[Scope of utility model registration request] Equipped with a positioning function that switches from fast-forwarding or rewinding to playback mode by detecting a no-signal area between signals recorded on the magnetic tape, and a display element that lights up to indicate the peak level of the recorded signal. In the tape recorder, a driving transistor that drives the display element, a control transistor connected to control the operation of the driving transistor, and a control transistor that is switched during a playback operation and operates the driving transistor by the control transistor. The switch is composed of a first switch for enabling the display element, and a second switch connected to apply a high voltage to the base of the drive transistor, which is switched during a fast forward or rewind operation, and is connected to apply a high voltage to the base of the drive transistor. A display circuit for a tape recorder, characterized in that the display circuit for a tape recorder displays that the positioning operation is in progress by keeping the light on.