Tape recording and/or reproducing apparatus

Abstract: In apparatus for switching between recording (REC) and playback (PB) modes of a tape recorder (14) having a single input/output jack (15) compatible with two channels to which an output plug (21) for an earphone or headphone (20), or an input plug (19) for a microphone (18) can be connected, when a remote control unit (16) having a remote-­ control switch (27) and connected to an input/output transducer (28) is connected to the jack (15), one channel is used as an input channel for a remote-control signal, and the other channel is used as an input/output channel for an audio signal. The tape recorder (14) may have a control circuit for discriminating between insertion of a 1-­ channel plug and insertion of a 2-channel plug into the jack (15) to control the operation of a switch (23) in the tape recorder (14).

Description: This invention relates to tape recording and/or reproducing apparatus, and in particular to apparatus for switching between operating modes of the tape recording and/or reproducing apparatus. In known compact tape recording and/or reproducing apparatus, hereinafter referred to as tape recorders, (for example, cassette tape recorders and headphone stereo units) and remote-controlled compact tape recorders, an input jack for receiving a microphone plug, an output jack for receiving an earphone plug, and a jack for receiving a remote-control unit may be provided separately; alternatively, a common jack that co-operates with a microphone, an earphone and a remote-control unit may be provided together with an exclusive selection switch that selectively configures the common jack to serve either as a microphone jack, an earphone jack or a remote-control jack. A tape recorder provided with two or three jacks involves inefficient space utilisation and cannot be made sufficiently compact for certain purposes. When a common earphone/microphone unit obtained by integrating an earphone and microphone by using an electromagnetic converting means is used in the tape recorder, a user must substitute an earphone/microphone plug in accordance with the playback (PB) or recording (REC) modes; therefore, the earphone/microphone unit cannot be efficiently utilised. In a tape recorder having a common jack and an exclusive selection switch, the selection switch must be operated manually in accordance with the selected mode, which is cumbersome and inconvenient. In addition, the user may tend to forget to select the appropriate mode with the selection switch. GB-A-2 077 023 discloses a remote control device for a tape recording/reproducing apparatus in which the remote control device is connected to the apparatus via a multi-conductor cable and plug. When the remote control device is not plugged into the apparatus, operation of the apparatus is modified. For example, the apparatus may be locked in the playback mode or a warning light activated when the remote control device is not plugged in. In accordance with the present invention there is provided apparatus for switching between operating modes of a tape recorder, the apparatus comprising: a tape recorder main body; a connector socket formed in the tape recorder main body; a predetermined operation switch arranged in the tape recorder main body; and a control circuit responsive to insertion of a plug into the connector socket to change the operation of the predetermined operation switch; characterised in that: the connector socket comprises a jack which can receive selectively a one-channel plug or a two-channel plug; detecting means are connected to the jack for detecting wether a one-channel plug or a two-channel plug is inserted into the jack; and the control circuit is responsive to the detecting means for enabling the function of the predetermined operation switch when a one-channel plug is inserted and for disabling the function of the predetermined operation switch when a two-channel plug is inserted. In a preferred embodiment of the present invention, to be described in greater detail hereinafter, there is provided apparatus for switching between REC and PB modes of a tape recorder which can be connected to an external earphone or headphone and an external microphone to perform recording and reproduction by using one jack as an input/output jack. In the preferred apparatus, input and output states of a jack are automatically switched or interlocked with a record/playback selection switch when an earphone/microphone plug is connected to the jack. Preferably, a control signal input from a remote-control unit for controlling the operation mode of the tape recorder, the output to an earphone, and the input from a microphone can be transmitted through one jack. A control circuit for determining whether a plug connected to a two-channel jack is of two- or one-channel type is preferably provided, and can inhibit operation mode setting control by an operation switch in the tape recorder main body as well as enabling operation mode setting control by the control signal from the plug when a two-channel plug is connected. The invention will now be described by way of example with reference to the accompanying drawings, throughout which like parts are referred to by like references, and in which: Figure 1 is a circuit diagram showing apparatus for switching between REC and PB modes of a tape recorder; Figure 2 is a diagrammatic view showing a tape recorder system having a remote-control unit according to an embodiment of the present invention; and Figure 3 is a detailed circuit diagram of a circuit in the tape recorder system shown in Figure 2. Referring initially to Figure 1, a tape recorder switching apparatus includes a speaker 1 incorporated in the tape recorder, a microphone 2 also incorporated therein, and a jack 3 having a ground terminal 8, a fixed terminal 9, and a movable terminal 10. The jack 3 selectively receives an earphone plug connected to an external earphone or headphone, a microphone plug connected to an external microphone, or an earphone/microphone plug connected to a combined earphone/microphone. When a plug is not inserted in the jack 3, the movable terminal 10 is in contact with the fixed terminal 9. When a plug is inserted into the jack 3, the movable terminal 10 is separated from the fixed terminal 9. The tape recorder also includes a playback amplifier 4, a recording amplifier 5, a ground line 6 of the playback amplifier 4, a ground line 7 for the recording amplifier 5, and recording/playback ganged selection switches 11, 12 and 13 which are interlocked with depression of recording and playback buttons REC, PB of the tape recorder. Each of the switches 11, 12 and 13 has a recording contact R, a common contact C, and a playback contact P. The switch 11 is used to connect the playback or recording amplifier 4 or 5 selectively to the movable terminal 10; the switch 12 is used to connect the speaker 1 or the microphone 2 selectively to the fixed terminal 9; and the switch 13 is used to connect the playback or recording amplifier 4 or 5 selectively to the corresponding ground line 6 or 7. Figure 1 shows the tape recorder in the PB mode. An output signal from the playback amplifier 4 is supplied to the speaker 1 through the contacts P and C of the switch 11, the movable and fixed terminals 10 and 9, and the contacts C and P of the switch 12. In the PB mode, when the external earphone plug or the external earphone/microphone plug is inserted into the jack 3, the movable terminal 10 is separated from the fixed terminal 9. In this state, the speaker 1 is disconnected, and at the same time, a playback output signal is sent from the movable terminal 10 to the earphone or the earphone/microphone through the inserted plug. In this case, the ground line 6 is connected to the terminal 8 through the contacts P and C of the switch 13. When a plug is not inserted into the jack 3 and the switches 11, 12 and 13 are switched to the REC side to set the REC mode, a recording signal from the microphone 2 is supplied to the recording amplifier 5 through the contacts R and C of the switch 12, the fixed and movable terminals 9 and 10, and the contacts C and R of the switch 11. In the REC mode, when the external microphone plug or the external earphone/microphone plug is inserted in the jack 3, the movable terminal 10 is separated from the fixed terminal 9, and therefore the microphone 2 is disconnected. An input signal from the external microphone is supplied from the plug to the recording amplifier 5 through the movable terminal 10 and the contacts C and R of the switch 11. In this case, the ground line 7 is connected to the terminal 8 through the contacts R and C of the switch 13. This embodiment exemplifies a tape recorder including the speaker 1 and the microphone 2. The switch 12 is omitted in a tape recorder not including the speaker 1 and the microphone 2. Figure 2 shows another embodiment of the invention. In Figure 2, a tape recorder 14 is controlled by a remote-control unit, and one 2-channel jack 15 is provided in the tape recorder 14. A plug 17 connected to a remote-control unit 16, a plug 19 connected to a microphone 18, a plug 21 connected to an earphone or headphone 20, or an earphone/microphone plug connected to an earphone/microphone (not shown) may be selectively connected to the jack 15. The apparatus can readily determine when the plug 17 of the remote-control unit 16 is connected to the jack 15, since the plug 17 is a 2-channel plug. On the other hand, the plugs 19 and 21 are both 1-channel plugs. REC (record), PB (playback), FF (fast-forward), and REW (rewind) buttons are provided on the tape recorder 14 in addition to the jack 15. A sliding pause switch 23, a built-in microphone 24, and a built-in speaker 25 are also provided in the tape recorder 14. A 1-channel jack 26 is provided on the remote-control unit 16. The plug 19 of the microphone 18 or the plug 21 of the earphone or headphone 20 may be selectively connected to the jack 26. A sliding pause switch 27 and a built-in microphone 28 are also provided on the remote-control unit 16. The operation of the system shown in Figure 2 is as follows. When the plug 19 is inserted into the jack 15 of the tape recorder 14 to set a REC mode, recording can be performed with the microphone 18. When the plug 21 is inserted into the jack 15 to set a PB mode, a reproduced sound can be listened to from the earphone or headphone 20 (these actions in the REC and PB modes being the same as those of the tape recorder shown in Figure 1). When the 2-channel plug 17 is inserted into the jack 15 to connect the remote-control unit 16 to the tape recorder 14, the connection is detected by a control circuit (to be described later). As a result, the function of the pause switch 23 of the tape recorder 14 is disabled. At the same time, the function of the pause switch 27 of the remote-control unit 16 is enabled. In this state, the buttons 22 are selectively used to set a desired mode and the pause switch 27 is slid to the START position. Then, the tape recorder 14 is operated in the set mode. In this case, if the REC mode is set, recording can be performed with the built-in microphone 28. When the PB mode is set, a reproduced sound can be listened to from the speaker 25 of the tape recorder 14. In the REC mode, when the plug 19 is inserted into the jack 26 of the remote-control unit 16, recording can be performed with the microphone 18. In the PB mode, when the plug 21 is inserted into the jack 26, a reproduced sound can be listened to from the earphone or headphone 20. In this manner, when the plug 19 or 21 is inserted into the jack 26, the remote-control unit 16 serves as a link connector for the recording or reproduced signal. In this case, the built-in microphone 24 and the speaker 25 are not operated. Figure 3 shows a detailed arrangement of a control circuit 29 for disabling the function of the pause switch 23 upon detection of the insertion of the 2-channel plug 17 into the jack 15. The reference characters in Figure 3 that are also used in Figure 2 denote the same parts in Figure 3 as in Figure 2. In Figure 3, 2-channel terminals R, L and a ground terminal G are arranged in the remote-control unit 16. These terminals can be connected to terminals R, L and G of the plug 17. A STOP contact of the pause switch 27 is connected to the terminal G of the remote-control unit 16 through a resistor R6. The common and START terminals of the pause switch 27 are connected to the terminal R of the remote-control unit 16. Terminals L and G of the jack 26 are respectively connected to the terminals L and G of the remote-control unit 16, as shown in Figure 3. Terminals L and G of the microphone 18 and the earphone or headphone 20 are respectively connected to corresponding terminals L and G of the plugs 19 and 21. In the control circuit 29, terminals L, R, R-1 and G are provided in the jack 15. A voltage V obtained from the terminal R is supplied to one input terminal of each of comparators 30 and 31. A reference voltage V1 obtained by voltage dividing a power source voltage Vcc by a resistor R3 and a set of resistors R4 and R5 is applied to the other input terminal of the comparator 30. A reference voltage V2 obtained by voltage dividing the power source voltage Vcc by the resistor R5 and the set of resistors R3 and R4 is applied to the other input terminal of the comparator 31. When the pause switch 23 is set to the START or STOP (pause) position, a transistor Q3 is switch-controlled to enable or disable a power source for a tape drive motor (not shown). When no plug is inserted into the jack 15, the terminals R and R-1 of the jack 15 are kept in contact with each other. The voltage V is then at ground potential. In this case, outputs from the comparators 30 and 31 are set at a high level. When the pause switch 23 is switched to the START position as shown in Figure 3, the power source voltage Vcc is applied to the base of a transistor Q2 through resistors R7 and R8 to turn on the transistor Q2. The on state of the transistor Q2 enables the transistor Q3, so that the power source voltage is applied to the tape drive motor (not shown). A recording tape starts running, and the tape recorder 14 is operated in whatever mode has been set, by previous selective operation of the buttons 22 (Figure 2). When the pause switch 23 is switched to the STOP position, the power source voltage Vcc is applied to the base of a transistor Q1 through the pause switch 23 and a resistor R10, thereby turning on the transistor Q1. When the transistor Q1 is turned on, the base potential of the transistor Q2 is decreased to turn off the transistor Q2. Therefore, the transistor Q3 is turned off thereby stopping the tape, and the pause state is set. When the 1-channel (monaural) plug 19 or 21 is connected to the jack 15, the terminal R of the jack 15 is grounded by the plug 19 and 21. The circuit state established in this case is therefore the same as in the case in which no plug is inserted into the jack 15. The operation can be controlled with the pause switch 23. In the PB mode, a reproduced signal obtained from a playback amplifier 32 is supplied to the earphone or headphone 20 through a contact PB of a recording/playback switch 34 and the terminals L of the jack 15 and the plug 21. In the REC mode, the recording (input) signal is supplied from the microphone 18 to a recording amplifier 33 through the terminals L of the plug 19 and the jack 15 and a contact REC of the switch 34. When the 2-channel plug 17 of the remote-control unit 16 is inserted into the jack 15, the terminal R-1 is separated from the terminal R of the jack 15. In this case, when the pause switch 27 of the remote-control unit 16 is set at the STOP position, a resistor R6 is connected in parallel with the resistor R2 in the control circuit 29. The voltage V determined by the resistors R1, R2 and R6 is applied to the comparators 30 and 31. The output of the comparator 30 is set at a high level, and the output of the comparator 31 is set at a low level. The signal of low level disables the transistor Q2. The switching off operation of the transistor Q2 in turn disables the transistor Q3, thereby setting the pause state. Then, even if the pause switch 23 of the tape recorder 14 is set in the START position, the state of the apparatus remains unchanged; in other words, the apparatus remains in the pause state. When the pause switch 27 of the remote-control unit 16 is then moved to the START position, the resistor R6 is disconnected, and the voltage V is changed accordingly so that the output of the comparator 30 is set at a low level and the output of the comparator 31 is set at a high level. Therefore, the transistors Q2 and Q3 are sequentially turned on to start tape travel. Even when the pause switch 23 is set at the STOP position in this state, the voltage Vcc drops at the resistor R10 so that the anode voltage of a diode D1 is such as to keep the transistor Q1 in the off state. The transistor Q2 thus remains turned on. As described above, when the plug 17 is inserted into the jack 15 to connect the remote-control unit 16 to the tape recorder 14, the function of the pause switch 23 of the tape recorder 14 is disabled and the function of the pause switch 27 of the remote-control unit 16 is enabled. In the REC mode, under the condition that the remote-control unit 16 is connected to the tape recorder 14, recording can be performed with the built-in microphone 28. A recording (input) signal is supplied to the recording amplifier 33 through the terminals L and L-1 of the jack 26, the terminal L of the plug 17, the terminal L of the jack 15 and the switch 34. When the plug 19 is inserted into the jack 26 to connect the microphone 18 to the tape recorder, the terminal L-1 is separated from the terminal L of the jack 15. In this case, the built-in microphone 28 cannot be used. In the PB mode under the same condition as described above, when the plug 21 is inserted into the jack 26 to connect the earphone or headphone 20 to the tape recorder 14, a reproduced signal from the playback amplifier 32 is supplied to the earphone or headphone 20 through the jack 15, the plug 17 and the jack 26. That is, when the plug 19 or 21 is inserted into the jack 26, the remote-control unit 16 serves as a link connector. Even if the remote-control unit 16 is used as a link connector, remote-control operation of the pause switch 27 can be performed. Therefore, even if the remote-control unit 16 is used together with the external earphone 18 or the external microphone or headphone 20, the user need insert only one plug 17 into the jack 15 of the tape recorder 14. The embodiments described above exemplify monaural recording and playback modes of the tape recorder 14. However, the present invention is also applicable to a stereo tape recorder. In addition, the microphone 18 and the earphone or headphone 20 may be constituted by common electromagnetic means.

Claims: Apparatus for switching between operating modes of a tape recorder, the apparatus comprising: a tape recorder main body (14); a connector socket (15) formed in the tape recorder main body (14); a predetermined operation switch (23) arranged in the tape recorder main body (14); and a control circuit (Q1, Q2, Q3) responsive to insertion of a plug into the connector socket (15) to change the operation of the predetermined operation switch (23); characterised in that: the connector socket comprises a jack (15) which can receive selectively a one-channel plug (19,21) or a two-channel plug (17); detecting means (30, 31) are connected to the jack (15) for detecting whether a one-channel plug or a two-channel plug is inserted into the jack (15); and the control circuit (Q1, Q2, Q3) is responsive to the detecting means (30, 31) for enabling the function of the predetermined operation switch (23) when a one-channel plug is inserted and for disabling the function of the predetermined operation switch (23) when a two-channel plug is inserted. Apparatus according to claim 1, wherein said two-channel plug (17) is connected to a remote-control unit (16), said remote-control unit (16) comprising a remote-control switch (27) for supplying a control signal for performing a remote-control operation of the tape recorder and an input/output unit (26) for input or output of an audio signal. Apparatus according to claim 2, wherein said remote-control switch comprises a pause switch (27) for performing on/off control of at least a pause function of tape travel. Apparatus according to claim 2 or claim 3, comprising means for supplying the control signal to said tape recorder main body (14) through one channel of each of said jack (15) and said two-channel plug (17) and for input/output of the audio signal through the other channel of each of said jack (15) and said plug (17) when said plug (17) is connected to said jack (15). Apparatus according to any one of the preceding claims, comprising a one-channel plug (19, 21) and connected to a signal system means and to said jack (15). Apparatus according to claim 5, wherein said signal system means comprises output signal system means (20). Apparatus according to claim 5 or claim 6, wherein said signal system means comprises input signal system means (18). Apparatus according to any one of the preceding claims, comprising recording amplifier means (5; 33) having an input terminal, playback amplifier means (4; 32) having an output terminal, and switching means (11, 12, 13; 34) for selectively switching said input terminal of said recording amplifier means (5; 33) and said output terminal of said playback amplifier means (4; 32) upon switching between the recording and playback modes. Apparatus according to claim 8, wherein the jack (3) has a ground terminal (8), a fixed terminal (9) and a movable terminal (10), and wherein the switching means (11) selectively connects said input or output terminal to said movable terminal (10) of the jack (3) respectively in the recording or playback modes. Apparatus according to claims 6, 7 and 9, including second switching means (12) for selectively connecting the output terminal of said output signal system means (1) and the input terminal of said input signal system means (2) to said fixed terminal (9) of the jack (3) respectively in the playback and recording modes. Apparatus according to claim 9 or claim 10, including further switching means (13) for selectively switching a ground terminal of said recording amplifier means (5) and a ground terminal of said playback amplifier means (4) upon switching between the recording and playback modes.

Inventors: UENO NORIYUKI C O PATENTS DIVI, UENO, NORIYUKI C/O PATENTS DIVISON
Applicants: SONY CORP, SONY CORPORATION
Application year: 1989
Main classification: G11B15
IPC codes: G11B31, G11B15