JP2000114998A - Md/radio combined machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the jump of a digital noise signal from the digital circuit of an MD recording/reproducing part to a radio reception part and to prevent malfunction by turning off the power of a digital circuit having no relation with the scanning in a period when the radio reception part executes scanning. SOLUTION: During scanning, it is checked whether broadcasting can be received or not by a detection signal S19. When broadcasting is received, scanning is stopped by a received frequency at that time. Data showing the received frequency is stored in a micro computer 50 and the broadcasting station at that time is preset in a station selection key in a key 51. The power of an MD recording/reproducing part 20 is turned on. When time passes, the attenuation quantity of an attenuator circuit 43 corresponds to a sound volume which a user designates. Thus, an A/D converter circuit 21 and a D/A converter circuit 38 do not generate digital noise signals by the MD/radio combined machine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an MD radio multifunction peripheral.

[0002]

2. Description of the Related Art MD for recording and playback as audio equipment
There is an MD radio multifunction peripheral in which an MD recording / reproducing device using a (mini disk) and a radio receiver are integrated. According to the MD radio MFP, the broadcast can be recorded on the MD while listening to the broadcast.

[0003]

However, an A / D converter circuit and a D / A converter circuit are provided in the MD recording / reproducing unit of the MD radio multifunction peripheral, and these operate based on a clock. , A digital noise signal is generated in the A / D converter circuit or the D / A converter circuit, and the digital noise signal jumps into the radio receiving unit.

In this case, when the radio receiving unit is for FM broadcasting and is receiving FM broadcasting waves at a sufficiently high level, a digital noise signal that jumps in from an A / D converter circuit or a D / A converter circuit. Is suppressed by the limiter function, so there is not much problem.

[0005] However, if there is a digital noise signal, when scan reception (a function of scanning a broadcast band and receiving a broadcast, stopping scanning and continuing reception at that frequency) is performed, scan reception is performed. Will malfunction. That is, if the scan sensitivity is set high, the scan stops even with a digital noise signal. Conversely, if the scan sensitivity is set low, the scan will not stop at a broadcast station with weak radio waves.

When a digital noise signal is present, the frequency of the digital noise signal is reduced when an auto-preset (a function of registering data of the frequency at the time of receiving a broadcast during scanning in a tuning key) is executed. The data is registered in the tuning key or, on the contrary, the data of the broadcast frequency is not registered.

Further, an area call (a function of registering frequency data and a broadcast station name for each reception area in a tuning key)
, The correct broadcast station name may not be displayed.

The present invention is to solve such a problem.

[0009]

Therefore, according to the present invention, in an MD radio multifunction peripheral in which an MD recording / reproducing unit and a radio receiving unit are integrated, during a period in which the radio receiving unit performs scanning, This is an MD radio multifunction peripheral in which the power of digital circuits not related to the scan is turned off. Therefore, during the scan,
Noise signals do not jump from the digital circuit of the MD recording / reproducing unit to the radio receiving unit.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Portable MD recorders / players and MD players are required to save power. Therefore, in recent years, A / D converter circuits and D / A
Even if the converter circuit is integrated into one IC, A
An IC with a power-down function capable of independently controlling the power of the / D converter circuit and the power of the D / A converter circuit has been developed.

On the other hand, in the state where scan reception or auto preset is being performed, broadcast cannot be listened to.
Broadcasts are not recorded on MD.

The present invention pays attention to these points, and enables the normal operation of scan reception and auto preset.

An embodiment of the present invention will be described below with reference to FIGS. FIG. 2 shows a part of FIG. 1 in a divided manner for the sake of space.

In FIG. 1 and FIG. 2, the MD radio multifunction device includes an FM receiving unit 10, an MD recording / reproducing unit 20,
A microcomputer 50 for system control. The microcomputer 50 is connected to various operation keys 51 as input means and a display element 52 such as an LCD.

When receiving an FM broadcast, the FM receiver 10 receives an FM broadcast wave signal by an antenna 11 and supplies the received signal to a mixer circuit 13 through a high frequency amplifier 12. Further, a local oscillation circuit is formed by the PLL to form a local oscillation signal. The local oscillation signal is supplied to the mixer circuit 13, and the local oscillation frequency is controlled by the microcomputer 50. The frequency of an FM broadcast wave signal of a target frequency is converted to an intermediate frequency signal and extracted.

Subsequently, the intermediate frequency signal is supplied to an FM demodulation circuit 17 through an intermediate frequency filter 15 and a limiter amplifier 16 to demodulate a stereo composite signal, and this signal is supplied to a stereo demodulation circuit 18 for left and right sides. The audio signals L and R of the channel are demodulated, and these signals L and R are supplied to the IC 41.

The IC 41 has switch circuits 42, 42 for function switching for two channels and attenuator circuits 43, 43 for volume control. The switch circuits 42, 42 and the attenuator circuits 43, 43 The switching and the amount of attenuation are controlled by a control signal S41 from the microcomputer 50.

At the time of receiving the FM broadcast, the switch circuits 42 and 42 are connected in the state shown in the figure, and the audio signals L and R from the stereo demodulation circuit 18 are transmitted through the switch circuits 42 and 42 and the attenuator circuits 43 and 43. The signals L and R taken out from the IC 41
Is supplied to the left and right channel speakers 45, 45 through the amplifiers 44, 44. Therefore, this MD
The radio multifunction peripheral can listen to the FM broadcast.

At this time, the intermediate frequency signal from the amplifier 16 is supplied to the detection circuit 19, and a detection signal S19 indicating the presence or absence of the broadcast is taken out, and the detection signal S19 is supplied to the microcomputer 50.

The recording of the FM broadcast being received is performed in the MD recording / reproducing section 20 as follows. That is,
A microcomputer 55 for managing the operation of the recording / reproducing unit 20 is provided, and the microcomputer 55 controls the recording / reproducing unit 20 according to an instruction from the microcomputer 50.

The audio signals L and R from the demodulation circuit 18 are supplied to the A / D converter circuit 21 through the switch circuits 42 and 42 and A / D converted into digital audio data. ATRAC processing (ATRAC processing)
Is compressed by a registered trademark) to a data amount of about 1/5.

Subsequently, the compressed data is
EF through the memory controller 23 and the memory 24
The signal is supplied to an encoding / decoding circuit 25 for M processing and CIRC processing, and is subjected to encoding processing for error detection and correction, and EFM (8-14 modulation) processing. Then, data from the encoder / decoder circuit 25 is supplied to the recording head 27 through the head driving circuit 26.

The head 27 is arranged so as to face one surface of a recording / reproducing MD (mini-disc) 30, and an optical pickup 31 for recording / reproducing is arranged on the opposite surface of the MD 30. I have. The MD 30 is rotated by a spindle motor 32, and the rotation is controlled by a servo control circuit 33 so that the linear velocity of the disk 30 is constant.

In this way, the audio data from the drive circuit 26 is recorded on the MD 30 by thermomagnetic recording by the light irradiation by the optical pickup 31 and the modulated magnetic field by the magnetic head 27.

At the time of recording, the focus and tracking of the optical pickup 31 are controlled by the servo control circuit 33.
And the head 27 and the optical pickup 31 are moved by the feed motor 34 in the radial direction of the MD 30. The detection output of the optical pickup 31 is supplied to an address decoder 37 through an RF amplifier 36 to extract an absolute address signal recorded in a pre-groove of the MD 30. The absolute address signal is supplied to an encode / decode circuit 24. To be inserted into the audio data and recorded on the MD 30. Further, the output signal of the RF amplifier 36 is supplied to the servo control circuit 33 and used for servo control.

Therefore, the broadcast received by the FM receiver 10 can be recorded on the MD 30 while listening to the speakers 45.

On the other hand, during reproduction of the MD 30, a reproduction signal of the optical pickup 31 is supplied to the RF amplifier 36, and a part of the signal is supplied to the servo control circuit 33 to reproduce a target signal. The signal is supplied from the amplifier 36 to the encode / decode circuit 37. In the encode / decode circuit 25, the reproduced signal is EF
The digital audio data is subjected to M demodulation and error correction, and the original digital audio data is compressed.

Further, the digital audio data is supplied to the encoding / decoding circuit 22 through the memory controller 23 and the memory 24 and is expanded to the original digital audio data. The digital audio data is supplied to the D / A converter 38. The original audio signals L and R are D / A converted. And
These signals L and R are supplied to the speakers 45 and 45 through the switches 42 and 42 and the attenuator circuits 43 and 43 connected in the state opposite to those shown in FIG.

Therefore, the F recorded on the MD 30
You can play back M broadcast and listen to it.

The present invention is further configured as follows. That is, the A / D converter circuit 21 and the D / A converter circuit 38 are
Even if it is C, it is assumed that these power supplies can be controlled on and off independently. And the microcomputer 5
From 0, the control signal PDAD of the operation mode is supplied to the A / D converter circuit 21, and the microcomputer 50 supplies the control signal PDDA of the operation mode to the D / A converter circuit 38. Further, a control signal PCON for turning on / off the power is supplied from the microcomputer 50 to the MD recording / reproducing unit 20.

When performing scan reception, the power supply of the A / D converter circuit 21 and the D / A converter circuit 38 is controlled by the control signals PDAD and PDDA, for example, as shown in FIG.

That is, when receiving the FM broadcast, as shown before time t11 in FIG. 3, PDAD = "L", and the A / D converter circuit 21 is set to the normal mode (power is turned on). At the same time, PDDA = “H” and the D / A converter circuit 38 is in the power down mode (power is off). S41 = “L”
And the attenuator circuits 43 and 43 have an attenuation amount (muting off) corresponding to the volume specified by the user.

However, when scan reception is instructed by the user with the key 51, S41 = "H" at time t11, and the attenuation of the attenuator circuits 43, 43 is maximized (muting is on). Then, at time t12, PDAD = "H", the A / D converter circuit 21 is set to the power down mode, and the local oscillation frequency of the local oscillation circuit 14 is sequentially changed step by step from time t12. And the scan is started.

During the scanning, it is checked whether or not the broadcast has been received by the detection signal S19.
When the broadcast is received, the scanning is stopped at the reception frequency at that time, PDAD = "L", and the A / D converter circuit 21 is set to the normal mode.

Further, at time t14, S41 = "L"
As a result, the attenuator circuits 43 and 43 have an attenuation amount corresponding to the volume specified by the user. Therefore, it becomes possible to listen to the broadcast selected by the scan reception from time t14.

On the other hand, when performing auto preset,
The power of the MD recording / reproducing unit 20 is controlled by the control signal PCON, for example, as shown in FIG.

That is, at the time of general FM reception, as shown before time t21 in FIG. 4, S41 = “L”, and the attenuator circuits 43, 43 are set to the amount of attenuation corresponding to the volume designated by the user. ing. Also, PCON = “H” and the power of the MD recording / reproducing unit 20 is turned on.

However, when an auto preset is instructed by the key 51 from the user, S41 = "H" at time t21, and the attenuation of the attenuator circuits 43, 43 is maximized. Then, at time t22, PCON = "L" and the MD recording / reproducing unit 20 is turned off, and
From this time point t22, the local oscillation frequency of the local oscillation circuit 14 is sequentially changed step by step, and scanning is started.

During the scanning, it is checked whether or not the broadcast has been received by the detection signal S19.
When the broadcast is received, the scan is stopped at the reception frequency at that time, and the data indicating the reception frequency at this time is stored in the microcomputer 50. The broadcast station is preset. Also, PCON = “H” and the power of the MD recording / reproducing unit 20 is turned on.

Further, at time t24, S41 = "L"
As a result, the attenuator circuits 43 and 43 have an attenuation amount corresponding to the volume specified by the user. Therefore, it becomes possible to listen to the broadcast selected by the auto preset from the time point t24, and at this time, the broadcast station of the broadcast is registered in the tuning key.

As described above, according to the above MD radio multifunction peripheral, scan reception and auto preset can be realized.
In the case of scan reception, the period t during which the scan is being performed
The A / D converter circuit 21 and the D / A
Since converter circuit 38 is in the power down mode, A / D converter circuit 21 and D / A converter circuit 38 do not generate digital noise signals. Therefore, the sensitivity of the scan can be increased, and even a broadcast station with a weak radio wave can be received by scan reception.

The D / A converter circuit 38 is provided with a FM
When the broadcast is being received, the power down mode is always set. However, the D / A converter circuit 38 needs to be operated only when the MD 30 is reproduced. In this state, there is no problem even if the D / A converter circuit 38 is set to the power down mode.

Further, since the A / D converter circuit 21 is in the normal mode until time t11 immediately before the start time t12 of the scan reception, when the FM broadcast is recorded on the MD 30 from the state of listening to the FM broadcast, You can immediately enter the recording state.

At time t12 or time t13 when the A / D converter circuit 21 switches to the power down mode or the normal mode, muting is applied by the signal S41. The noise noise generated is the speaker 45,
45 can be suppressed.

Further, also in the case of the auto-preset, since the power of the MD recording / reproducing unit 20 is turned off during the period of the scan from t22 to t23, no noise signal is generated. The scanning sensitivity can be increased, and even a broadcasting station with weak radio waves can be auto-preset. In this case, since the scan is not performed for selecting a broadcast but for auto-preset, there is no problem even if the power of the MD recording / reproducing unit 20 is turned off.

At time t22 or time t23 when the power of the MD recording / reproducing unit 20 is turned off or on, the signal S
Since the muting is applied by 41, it is possible to suppress the noise sound generated by turning on / off the power of the MD recording / reproducing unit 20 from being output from the speakers 45.

Further, the above functions can be easily realized by adding some circuits to the existing MD radio multifunction peripheral and changing only a part of the program executed by the microcomputer 50. it can.

In the above description, by using the power down function of the A / D converter circuit 21 and the D / A converter circuit 38, the influence of the digital noise signal generated from them on the FM receiver 10 is eliminated. However, when a digital noise signal generated in an IC such as a DSP or a driver used in the MD recording / reproducing unit 20 affects the FM receiving unit 10, the functions of those ICs are stopped and the digital The effects of noise signals can also be avoided.

If the power supply and the clock of the functional blocks inside the IC are stopped in accordance with the operation mode of the IC,
It is possible to reduce noise radiation and conductive noise from C itself.

Further, in the above description, the present invention is applied to the MD
This applies to multifunction devices with a recording / reproducing device and an FM receiver, but it is necessary to control the digital power supply and clock for circuits that are easily affected by noise signals from digital systems, such as communication devices. Thus, the influence of noise can be reduced.

[0051]

According to the present invention, the detection sensitivity at the time of scan reception can be increased, and even a broadcasting station with weak radio waves can
It can be received by scan reception. Further, the detection sensitivity at the time of auto-preset can be increased, and the auto-preset can be performed even in a broadcasting station with weak radio waves. Moreover, these functions can be easily realized only by changing a part of hardware and software.

[Brief description of the drawings]

FIG. 1 is a system diagram illustrating one embodiment of the present invention.

FIG. 2 is a system diagram showing one embodiment of a part of the circuit of FIG. 1;

FIG. 3 is a timing chart for explaining the present invention;

FIG. 4 is a timing chart for explaining the present invention.

[Explanation of symbols]

10 = FM receiver, 11 = antenna, 12 = high frequency amplifier, 13 = mixer circuit, 14 = local oscillation circuit, 15 = intermediate frequency filter, 16 = limiter amplifier, 17 = FM demodulation circuit, 18 = stereo demodulation circuit, 19 = Detection circuit, 2
0 = MD recording / playback unit, 21 = A / D converter circuit, 2
2 = encoder / decoder circuit, 23 = memory controller, 24 = memory, 25 = encoder / decoder circuit, 26 = head drive circuit, 27 = print head, 30 =
MD, 31 = optical pickup, 32 = spindle motor, 33 = servo control circuit, 34 = feed motor, 38 =
D / A converter circuit, 41 = IC, 42 = Switch circuit, 43 = Attenuator circuit, 44 = Amplifier, 45 = Speaker, 50 = Microcomputer, 51 = Operation key, 52 = Display element, 55 = Microcomputer

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Claims (4)

[Claims] In an MD radio multifunction peripheral in which an MD recording / reproducing unit and a radio receiving unit are integrated, a power supply of a digital circuit not related to the scanning is turned off while the radio receiving unit is performing a scan. MD radio multifunction printer 2. The MD radio multifunction peripheral according to claim 1, wherein the scan is a scan for scan reception, and the digital circuit includes an A / D converter included in the MD recording / reproducing unit.
An MD radio multifunction peripheral having a D converter circuit and a D / A converter circuit. 3. The MD radio multifunction peripheral according to claim 1, wherein the scan is a scan for an auto preset, the digital circuit is a digital circuit of the MD recording / playback unit, An MD radio multifunction peripheral that stops oscillation of the digital circuit during scanning. 4. The MD radio multifunction peripheral according to claim 1, wherein when the scan is a scan for scan reception, the digital circuit includes an A / D converter circuit and a D / D converter included in the MD recording / reproducing unit. / A converter circuit, wherein when the scan is a scan for an auto-preset, the digital circuit is a digital circuit of the MD recording / playback unit, and during the scan for the auto-preset, the digital MD radio multifunction machine that stops the oscillation of the circuit.