JPH0233302Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tape recorder that can selectively perform a memory autoplay operation and an automatic song selection operation using a simple circuit configuration.

Generally, in memory auto play operation and automatic song selection operation, a fast forward (or rewind) mode is obtained with the playback mode mechanically locked, and when in this fast forward (or rewind) mode, predetermined settings related to tape running are performed. Fast-forward (or rewind) using a memory switch that closes when the counter value is reached and a no-signal detection circuit that detects no-signal areas on the tape.
The mode is canceled and the reproduction mode is obtained from the tape position corresponding to the counter value or from the beginning of the signal area following the no-signal area.

The present invention provides a single plunger, mechanically locks the playback mode, and electrically locks the fast forward (or rewind) mode using the plunger, thereby achieving memory autoplay operation. And automatic music selection operations can be performed easily.

Embodiments of the tape recorder of the present invention shown in the drawings will be described below.

1 is a plunger that electrically locks the fast forward (or rewind) mode when the fast forward (or rewind) mode is obtained with the playback mode mechanically locked; 2 is connected to the drive circuit of the plunger 1; A PNP type switching transistor 3 is a selection switch in which a common terminal A is connected to the base of the switching transistor 2. The selection switch 3 has a memory terminal 8 for obtaining memory operation and an automatic music selection terminal C for obtaining automatic music selection operation.
has. Reference numeral 4 denotes a memory switch which is connected to the memory terminal B of the selection switch 3 and closes when a predetermined counter value related to tape running is reached.For example, in the case of a counter consisting of a number wheel, the number on the number wheel is " 9,9,9” and “0,0,
It is configured to be closed when the number is between 0 and open when the number is other than 0. 5 and 6 are resistors and capacitors that determine the cut-off time of the transistor 2, and 7 is a bias resistor of the transistor 2.
Reference numeral 8 denotes a no-signal detection circuit which is connected to the automatic music selection terminal C of the selection switch 3 and generates a pulse voltage when a no-signal portion on the tape is detected.

The tape recorder of the present invention is constructed as described above, and its operation will be explained below.

When the selection switch 3 is switched to the memory terminal B side, the base current of the switching transistor 2 flows through the resistor 7 as shown in FIG. 2, the transistor 2 becomes conductive, and the plunger 1 becomes operational. Therefore, in this state, the fast forward (or rewind) mode can be locked by the plunger 1, so the tape can be fast forwarded or rewound while the playback mode is obtained. At this time, memory switch 4 is open. As the tape runs, the counter value changes to "9, 9, 9".
and "0, 0, 0", the memory switch 4 is closed, and at this time, as shown in FIG. 3, the base voltage of the switching transistor 2 increases through the resistor 5, and the corresponding Since a reverse bias is applied to the transistor 2, the transistor 2 becomes non-conductive and the plunger 1 becomes inoperable. At the same time, the charge in the capacitor 6 that was charged when the memory switch 4 was opened is discharged via the memory switch 4 and the resistor 5 with a certain time constant.

Therefore, even if the memory switch 4 is closed for a short time, the charge in the capacitor 6 that was charged is discharged while the memory switch 4 is closed. While the capacitor 6 is being charged, a charging current flows as shown in FIG. 4, so that the transistor 2 remains non-conductive. Plunger 1 is therefore inactive for a period of time necessary to release the fast forward (or rewind) mode, thereby obtaining the playback mode from the memory location on the tape. I can do it.

Next, when the selection switch 3 is switched to the automatic music selection terminal C side as shown in FIG.
Since the output of the no-signal detection circuit 8 is at a low level, a base current flows through the selection switch 3 and the resistor 9, causing the switching transistor 2 to conduct and the plunger 1 to be in an operating state.

Therefore, in such a state, the fast forward (or rewind) mode can be locked by the plunger 1, so that the tape can be fast forwarded or rewound while the playback mode is obtained. At this time, the playback head is in contact with the tape, and when the playback head detects a no-signal area on the tape, a positive pulse voltage is generated from the no-signal detection circuit 8, and this pulse causes the switch to be activated. A reverse bias is applied to the base of the switching transistor 2 to make the switching transistor 2 non-conductive and to disable the plunger 1.

The pulse voltage at this time has a time width that renders the plunger 1 inoperative for the time necessary to change the mechanism from the fast forward (or rewind) state to the playback state, resulting in the fast forward (or rewind) mode. is released and enters the playback mode, and it is possible to play back from the beginning of the next signal-bearing section on the tape, that is, to achieve automatic song selection operation.

As described above, the present invention provides a plunger that electrically locks the fast forward (rewind) mode when the play mode is mechanically locked and a fast forward (rewind) mode is obtained, and a drive circuit for the plunger. a memory/automatic music selection selection switch having a common terminal connected to the base of the switching transistor connected to the switching transistor;
a memory switch that is connected to the memory terminal of the selection switch and that closes when a predetermined counter value related to tape running is reached and applies a reverse bias to the switching transistor; and a memory switch that is charged when the memory switch is closed. A capacitor is charged through a discharging resistor and discharged through a discharging resistor when the memory switch is closed; The circuit includes a no-signal detection circuit that applies a bias, and discharges and charges the capacitor in connection with closing and opening of the memory switch during memory autoplay operation, and the charging current causes the switching transistor to become non-conductive. Since it is configured to hold the state, even if the memory switch is closed for a short time, that is, less than the time for the plunger to release the fast forward (or rewind) mode, the capacitor is The transistor remains non-conducting while the charging current flows for charging, making it possible to ensure that the plunger is inactive for the required period of time, which is extremely useful in eliminating malfunctions when switching modes. It is something.

[Brief explanation of the drawing]

FIG. 1 shows a circuit configuration diagram of the tape recorder of the present invention, FIGS. 2 to 4 are explanatory diagrams during memory operation, and FIG. 5 is an explanatory diagram during automatic music selection operation. 1... Plunger, 2... Switching transistor, 3... Selection switch, 4... Memory switch, 8... No signal detection circuit.

Claims (1)

[Scope of utility model registration request] When obtaining fast forward (rewind) mode with the playback mode mechanically locked, the fast forward (rewind)
A plunger that electrically locks the mode, a switching transistor connected to the drive circuit of the plunger, a memory/automatic song selection switch whose common terminal is connected to the base of the switching transistor, and a memory of the selection switch. a memory switch that is connected to the terminal and closes when a predetermined counter value related to tape running and applies a reverse bias to the switching transistor; and a memory switch that is charged through a charging resistor when the memory switch is opened; A capacitor is discharged through a discharge resistor when the memory switch is closed, and a capacitor is connected to the automatic selection terminal of the selection switch and applies a reverse bias to the switching transistor when a no-signal area on the tape is detected. and a signal detection circuit, which discharges and charges the capacitor in connection with closing and opening of the memory switch during memory autoplay operation, and maintains the non-conducting state of the switching transistor by the charging current. A tape recorder characterized in that it is configured as follows.