JPH02110845A - Audio signal reproducing device - Google Patents

Abstract

PURPOSE:To prevent a battery from consuming uselessly by constituting the audio signal reproducing device in such a manner that when a power source of a receiver is turned off, the reproducing device becomes effective of its stop mode. CONSTITUTION:When a stop button 32 is pressed under a reproducing mode (and other operation modes), a lock plate is disengaged so that a reproducing button 31 is restored to a stop mode position. Consequently, heads 12L and 12R and a pinch roller 34 are restored to the stop mode position, while a switch 36 is switched off to make the reproducing device 1 effective of the stop mode. By this method, even when it is forgotten to press the stop button of the reproducing device 1 at the time of cutting off the power source of the receiver, the battery 35 of the reproducing device 1 is not uselessly consumed, and the stop operation is not troublesome even when the reproducing device 1 is put in a briefcase or a bag.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an audio signal reproducing device.

[Invention (already required)]

For example, in a headphone-type portable stereo playback device such as the Walkman (registered trademark), when a wireless system is used between the main body of the playback device and the headphones, the main body of the playback device can be remotely controlled from the headphone side. This improves usability.

[Conventional technology] Headphones such as Walkman and cassette players (
Hereinafter, a player (hereinafter simply referred to as a "player") that connects the player and headphones using a wireless method is being considered.

FIG. 4 is a perspective view showing the appearance of an example of the wireless player, in which (1) is the player and (6) is a dedicated receiver for the headbond.

In the player (1), when the left and right channel stereo audio signals R are played back from the tape cassette (not shown), this signal R
are converted into FM signals St, , Ss, and the signals SL, S, l are further transmitted to the receiver (6).

Then, in the receiver, the FM from the player (1)
When the signals SL and SR are received, an audio signal R is demodulated from the signals S and SR, and these signals R and R are sent to the left and right acoustic units (7L) of the headphones (7).
, (7R).

In this case, the receiver (6) may be half the size of a business card or less.

Therefore, when listening to a cassette while commuting, for example, on the train, you can put the player (1) in your purse or bag, put the receiver (6) in your jacket's breast pocket, or use the clip to put it on your collar or necktie. The headphones (7) can be used without the cord getting in the way.

The distance at which the receiver (6) can be used away from the player (1) is 1.5 m, taking into account the Radio Law and the possibility that someone nearby is using a similar wireless player.
It is considered to be a degree.

Literature: JP-A-63-108825, JP-A-62-
The specification and drawings of No. 280489 [Problems to be Solved by the Invention] However, in the wireless player described above, when you stop listening to a cassette, you turn off the power switch of receiver 1 (6) and turn off the player. The player (1) must be placed in stop mode by pressing the stop button (1).

However, the player (1) and headphones (7) are normally used separately (this is why they are wireless), and when the receiver (6) is turned off, Sometimes I forget to put the player (1) inside a puffer fish into stop mode.

Then, the player (1) wastes battery power by continuing to use the playback mode until the tape is played to the end and the auto-shutoff mechanism is activated. Or, if the player (1) is set to auto-repeat mode, it will continue playing until the battery runs out.
It still wastes battery power.

Furthermore, even if you do not forget to set the player (1) to stop mode, you should turn off the power to the receiver (6), and moreover, if you do not forget to put the player (1) in the stop mode.
) is a pain to press the stop button.

This invention attempts to eliminate the above problems.

[Means to solve the problem]

Therefore, in the present invention, when the power of the receiver (6) is turned off, this is detected in the player (1), and the player (1) is placed in the stop mode based on the detection output.

Furthermore, when the receiver (6) is turned off, it is necessary to transmit that information to the player (1), and this is done as follows.

That is, considering the receiver (6) now, it only needs to receive the FM signals SL and S11 of a specific frequency, so its tuner circuit should have either a straight type or a superheterodyne type configuration. be able to. In the case of the superheterodyne system, when the receiver (6) is powered off, the local oscillation circuit stops oscillating, and no local oscillation signal can be obtained.

Therefore, in the present invention, the reception n(6) is of the superheterodyne type, and the leakage of the local oscillation signal that can be heard when the power is turned on is made thick within an allowable range.

Then, the player (
1), and when the local oscillation signal is not detected for a predetermined period, it is determined that the receiver (6) is powered off.

(Operation) When the power of the receiver (6) is turned off, the player (1) enters the stop mode.

〔Example〕

FIG. 1 shows an example of a player (1), and FIG. 2 shows an example of a receiver (6).

In the player (1), (1o) is a playback circuit, (11) is a cassette magnetic tape, (20) is a transmission circuit, (31) is a playback button, 35) is a battery for power supply,
(4o) is a superheterodyne tuner circuit;
(53) is a plunger. Further, in the receiver (6), (60) is a superheterodyne tuner circuit, and (81) is a battery for power supply.

When the playback button (31) of the player (1) is pressed, the pressed state is held by a lock plate (not shown). Also, in conjunction with the button (31), the playback head (1
2L) and (12+?) are brought into contact with the tape (11), the pinch roller (34) touches the capstan (3
It is transferred to 3). Furthermore, the power switch (36) is turned on in conjunction with the button (31), and the voltage of the battery (35) is supplied to each part as the operating voltage through the switch (36). Therefore, the player (1) is in playback mode.

Note that when in this playback mode (and other operating modes), if the stop button (32) is pressed, the rerotator plate is disengaged and the playback button (31) returns to the stop mode position, thus the head (12L).

(12R) and the pinch roller (34) return to the stop mode position, the switch (36) is turned off, and the player (1) enters the stop mode.

Then, when the playback mode is entered by pressing the playback button (31), the heads (12L) and (12R) play back the left and right channel stereo audio signals R and R from the tape (11). However, through the playback amplifier (13L) and (13R), the stereo
＼As well as being taken out by Tsudohonjiyaku (14),
F through drive amplifier (21L), (21R)
It is supplied to the M modulation circuits (22!,) and (22R) as their modulation signals.

In this case, the resonant circuits of the FM modulation circuits (22L) and (22R) are composed of a coil, a capacitor, and a variable capacitance diode for FM modulation, and the amplifiers (21L) and (21R) are connected to the variable capacitance diode.
The audio signal R is supplied as a control voltage (modulation signal) to form FM signals SL and SR.

However, in this case, if the carrier frequency of the signals St, S* is f,,L, then this carrier frequency f, is the original transmission frequency (carrier frequency) f,.

It is assumed to be a fraction of f8, for example f i =12,67MH2f -=12.21MHz
It is said that

The FM signals SL, S are then supplied to the mixer circuit (23) for frequency conversion, and are also supplied to the oscillation circuit (23).
The alternating signal S4 is taken out from 4), and this signal S4 is supplied to the mixer circuit (23).

In this case, the resonant circuit of the oscillation circuit (24) is constituted by a highly stable solid-state resonator, such as a lithium tantalate resonator. Further, the signal S4 is, for example, the fifth harmonic generated by the lithium tantalate resonator, and the frequency r4 of the signal S is, for example, f a = 88.67 MHz.

Since such a signal S is supplied to the mixer circuit (23), the mixer circuit (23) outputs the frequencies f,
, fjI is fL-f4-fL=88.67-12.67
=76, OMt(zfR=f4-f, -88,67-12,21=
FM signals SL and SR of 76.46 Mtlz and signal components of unnecessary frequencies are extracted.

Therefore, the output signal of the mixer circuit (23) is supplied to the bandpass filter (25) to adjust the carrier frequency to fL.
, fR's FM signals S, , S, are extracted, and these signals S and SR are sent to the antenna (
27) and is transmitted from the antenna (27).

Moreover, in the receiver (6), the power switch (82)
When turned on, the voltage of the battery (81) is supplied to each part and the receiver (6) enters the reception mode.

Then, the FM signals SL, SR from the player (1) are received by the antenna (61), and the signals SL, S,
These signals are supplied to a mixer circuit (64) through a tuning circuit (62) whose pass band is only SL, S, and l and a high frequency amplifier (63), and a local oscillation circuit (65).
A local oscillation signal S with a frequency fS, for example r 5 =65.76 MHz, is extracted from the signal S.

is supplied to the mixer circuit (64).

In this way, in the mixer circuit (64), the signal 5LSR
is caused by the signal S, at an intermediate frequency f,,f, e.g., r, = f L-f, = 76.0-65.76-
10.2411Mz f ,=f R-f ,=76.46-65.76=
The frequency is converted into intermediate frequency signals SL and SR of 10.7 MHz.

Then, these signals SL and SR are passed through an intermediate frequency filter (71L) composed of, for example, a ceramic filter.
(71R) and filters (71R), (
Signals SL and SR are respectively taken out from the intermediate frequency amplifier (72L) and the intermediate frequency amplifier (72L).
(72R) to the FM demodulation circuit (73L), (7
3R), the audio signal is demodulated, and R is demodulated.
This signal, R is the output amplifier (74L), (74R
) through the headphone (7) unit (7L),
(7R).

Note that at this time, the demodulated output of the demodulating circuit (73R) is A
The voltage is supplied to an FC voltage forming circuit (75) to form an AFC voltage, and this AFC voltage is supplied to a local oscillator circuit (65) to perform AFC.

Therefore, the audio signals R and R reproduced from the tape (11) can be listened to through the wireless headphones (7).

In this case, the resonant circuit of the local oscillator circuit (65) can be composed of a coil, a capacitor, and a variable capacitance diode for AFC, but at this time, by selecting the values of each element, etc. (65) The level of the local oscillator signal S5 leaking to the outside is within a range that does not cause problems, for example, the transmitted signal SL.

It is allowed to grow within similar limits as SR.

And the signal S5 leaking from this receiver (6)
is detected in the player (1). That is, in the player (1), the signal S is transmitted by the antenna (41).
, is received, and this signal S is supplied to the mixer circuit (44) through the tuning circuit (42) and the high frequency amplifier (43), and is also supplied to the mixer circuit (44) from the local oscillation circuit (45) with a local oscillation signal having a frequency of, for example, 76.46 M1lz. A signal is supplied to a mixer circuit (44), and the signal S has an intermediate frequency of, for example, l.
o, 7M) Iz is frequency converted to an intermediate frequency signal S,
This signal S is transmitted through an intermediate frequency filter (46) composed of, for example, a ceramic filter and an intermediate frequency amplifier (
47) to an AM detection circuit (48), where the detected signal S is extracted.

Then, this signal Sll is supplied to a falling trigger type monostable multi-bi break (52) through a time constant circuit (5I), and its output signal S2 is sent to a plunger (
53).

In this case, the time constant circuit (51) outputs the signal S at the "1" level when the signal SB is obtained, and even if the signal S is no longer obtained, the time constant circuit (51) outputs the signal S, -" for several seconds to several minutes. The plunger (53), when driven, releases the lock plate that holds the playback button (31) in the pressed state.

Therefore, while listening to a cassette using the receiver (6), the time point to Figure 3 and as previously shown,
The signal Ss is leaking from the receiver (6), and
This is received by the tuner circuit (40), and as shown in FIG. B, a detected signal S8 is obtained before time L1.

Then, in the state where the signal S8 is obtained, at time 1 in C of the figure. As shown previously, S,=°“1”, and S,
="1", the multivibrator (52) is not triggered and the player (1) continues in the playback mode.

However, if you turn off the power switch (82) of the receiver (6) at any point in time to stop listening to the cassette, the local oscillator circuit (65) will stop from that point t1, so leaks will occur from now on. The signal S, which had been available, is no longer obtained from time t1.

And time point 1. When the signal S, is no longer obtained from SI-“, at time t2 several seconds or minutes later,
becomes 0''.

Then, when Sl becomes "°0", this fall triggers the multi-by-break (52), and as shown in the same figure, the signal S2 which becomes "L" for a predetermined period from time 2 is taken out. This signal S2 is connected to the plunger (5
3). Therefore, since the plunger (53) is driven at time t2, the lock plate is released, the playback button (31) is released, and the player (
1) goes into stop mode. That is, when the power switch (82) of the receiver (6) is turned off, the period (mu,~tz
), the player (1) goes into stop mode.

Thus, according to the present invention, when the power of the receiver (6) is turned off in the wireless headphone type cassette player, this is detected in the player (1) and the player (1) is placed in the stop mode. Even if one forgets to press the stop button of the player (1) when the receiver (6) is turned off, the battery (35) of the player (1) is not wasted.

Also, when the power of the receiver (6) is turned off, the player (
Since player (1) automatically enters stop mode,
Even if you put it in your bag or bag, stopping it will not be a hassle.

Furthermore, since the receiver (6) is of a superheterodyne type and leaks its local signal S, the power state of the receiver (6) is transmitted to the player (40). ), check the power status of the player (1
) There is no need to provide a transmitting circuit for transmitting data, resulting in a significant cost reduction.

Further, the tuner circuit (40) uses an IC for FM radio, and its output signal for tuning display can be used as the detection signal S, so the tuner circuit (40) is also low cost. Furthermore, players (such as plungers (53))
The mechanism for setting 1) to the stop mode can also use an auto-shutoff mechanism or a tape transport in a wired remote control mechanism, so it is also low cost.

Also, when using the player (1) and receiver (6), depending on the conditions of use, the tuner circuit (40)
Although it may sometimes become impossible to receive the signal S,
Even in such a case, the time constant circuit (51) maintains S,='1'°, so that the player (1) will not accidentally enter the stop mode.

Furthermore, although the lithium tantalate resonator is somewhat expensive, only one lithium tantalate resonator is required in the oscillation circuit (33) despite transmitting two FM signals SL and St. , resulting in low cost.

In addition, the FM signals SL and SR to be transmitted are transmitted by a modulation circuit (2
2L), FM signals SL, S, from (22R),
The frequency is converted (up-converted) using the alternating signal S4, and the resonance circuits of the modulation circuits (22L) and (22R) are composed of capacitors and coils, so the carriers of the transmitted FM signals SL and SR are frequency f
t.

``The stability of 8 should be an issue.

However, since the alternating signal S4 for frequency conversion is formed by a lithium tantalate resonator, the frequency f4 of the signal S4 is sufficiently stable, and the transmitted FM signal SL,
The fluctuation N (absolute M) of the carrier frequencies fL, fi of S, is the carrier frequency f,, f of the FM signals SL, SR from the modulation circuits (22L), (22R).

is equal to the amount of variation in And the carrier frequency f,
f, is approximately 1/6 of the original carrier frequency fL, f,
Therefore, the amount of variation in carrier frequencies fL, f is also approximately 1/
6, for example, at most ±50kHz,
If this is the amount of frequency fluctuation, this is the receiver (6)
This can be sufficiently covered by the AFC operation of , and there is no problem.

Therefore, the FM signals SL and Si with stable carrier frequencies ft and fg can be formed with an inexpensive configuration.

In the above description, the player (1) is a cassette player, but it may be a CD player, a DAT player, or the like. Further, the antennas (27) and (41) may be of any type as long as they effectively act as antennas, and the antenna (61) can also be used as the cord of the headphones (7). Furthermore, it is also possible to omit the local oscillation circuit (45) and obtain the local oscillation signal from the oscillation circuit (24). Further, an AFC loop can also be provided in the tuner circuit (40).

[Effects of the Invention] According to the present invention, in the wireless handphone 2 cassette player, when the receiver N (6) is turned off, this is detected in the player (1) and the player (1) is placed in the stop mode. Therefore, even if you forget to press the stop button on the player (1) when the receiver (6) is turned off, the battery (35) of the player []) may be wasted. do not have.

Also, when the power of the receiver (6) is turned off, the player (
Since player (1) automatically enters stop mode,
Even if you put it in your bag or bag, you won't have to worry about stopping it.

Furthermore, since the receiver (6) is of a superheterodyne type and leaks its local signal S, the power state of the receiver (6) is transmitted to the player (4o). ), check the power status of the player (1
) There is no need to provide a transmitting circuit for transmitting data, resulting in a significant cost reduction.

Further, the tuner circuit (40) uses an IC for FM radio, and its output signal for tuning display can be used as the detection signal S, so the tuner circuit (40) is also low cost. Furthermore, players (such as plungers (53))
The mechanism for setting 1) to the stop mode can also use an auto-shutoff mechanism or a tape transport in a wired remote control mechanism, so it is also low cost.

Also, when using the player (1) and receiver (6), depending on the conditions of use, the tuner circuit (40)
Although it may sometimes become impossible to receive the signal S,
Even in such a case, the time constant circuit (51) allows S +
= "1", the player (1) will not accidentally go into stop mode.

Furthermore, although lithium tantalate resonators are somewhat expensive, only one lithium tantalate resonator is required in the oscillation circuit (33) despite transmitting two FM signals SL, , Sm. Therefore, it becomes low cost.

In addition, the FM signals SL and SR to be transmitted are transmitted by a modulation circuit (2
2L), FM signals SL, S, from (22R),
The frequency is converted (up-converted) using the alternating signal S4, and the resonance circuits of the modulation circuits (22L) and (22R) are composed of capacitors and coils, so the carriers of the transmitted FM signals SL and SR are frequency f
[The stability of R should be an issue.

However, since the alternating signal S4 for frequency conversion is formed by a lithium tantalate resonator, the frequency f4 of the signal S4 is sufficiently stable, and the transmitted FM signal SL,
The amount of variation (absolute amount) in the carrier frequencies f, , fR of S, is the carrier frequencies fL, f of the FM signals S,, S, from the modulation circuits (22L) and (22R).

is equal to the amount of variation in And the carrier frequency f,
f, is approximately 1/6 of the original carrier frequency fL, f,
Therefore, the amount of variation in carrier frequencies fi, f, and l is also approximately 1.
/6, for example, at most ±50kl+z, and if the amount of frequency fluctuation is like this, the receiver (
The AFC operation in step 6) can sufficiently cover this and will not cause any problems.

Therefore, the FM signals SL, S with stable carrier frequencies ft, fR can be formed with an inexpensive configuration.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 are system diagrams of an example of the present invention, and FIGS. 3 and 4 are diagrams for explaining the same. (1) is a headphone stereo player, (10) is a playback circuit, (20) is a transmitter circuit, (40) is a tuner circuit, (53) is a plunger, (6) is a receiver, (60) is a tuner circuit, (The force is the headphones.

Claims (1)

[Claims] 1. The player has a player and a receiver, and the player has a reproducing means for reproducing an audio signal from a cassette, a CD, etc., and an FM modulator for converting the reproduced audio signal into an FM signal. the receiver includes a superheterodyne tuner circuit that receives the FM signal and demodulates the audio signal; headphones to which an audio signal is supplied, and a power switch that controls power supply to the tuner circuit, and when the receiver is in operation, a local oscillation signal of a local oscillation circuit in the tuner circuit is transmitted to the power switch. is transmitted from the receiver to the player as a signal indicating that the tuner is on, and in the player, the tuner circuit receives the local oscillation signal transmitted from the receiver, and the output signal of the tuner circuit. is supplied to the control means, and when the tuner circuit cannot receive the local oscillation signal from the receiver, the playback means is set to a stop mode by the control means. . 2. It has a reproduction means for reproducing an audio signal from a cassette, a CD, etc., an FM modulation circuit for converting the reproduced audio signal into an FM signal, a tuner circuit, and a control means for setting the reproduction means to a stop mode. The player includes a superheterodyne tuner circuit that receives the FM signal and demodulates the audio signal, headphones to which the demodulated audio signal is supplied, and a power switch that controls power supply to the tuner circuit. and when a local oscillation signal of a local oscillation circuit in the tuner circuit of the receiver is transmitted as a signal indicating that the power switch is on, The tuner circuit receives the local oscillation signal from the receiver, supplies the output signal of the tuner circuit to the control means, and when the tuner circuit can no longer receive the local oscillation signal from the receiver, A player for an audio signal reproducing device, wherein the reproducing means is set in a stop mode by a control means. 3. It has a reproduction means for reproducing an audio signal from a cassette, a CD, etc., an FM modulation circuit for converting the reproduced audio signal into an FM signal, a tuner circuit, and a control means for setting the reproduction means to a stop mode. A superheterodyne tuner circuit that is used in combination with the player and receives the FM signal and demodulates the audio signal, headphones to which the demodulated audio signal is supplied, and controls power supply to the tuner circuit. and a power switch, when the power switch is on, a local oscillation signal of the local oscillation circuit in the tuner circuit is transmitted to the player as a signal indicating that the power switch is on; When the transmitted local oscillation signal is received by the tuner circuit, and the output signal of the tuner circuit is supplied to the control means so that the local oscillation signal cannot be received by the tuner circuit, the tuner circuit receives the local oscillation signal. A receiver for an audio signal reproducing device, wherein the reproducing means is set to a stop mode by a control means.