JP2005252726A - Broadcasting receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a broadcasting receiver with which a user can easily listen to sound even without correcting sound quality each time a channel is selected by making sound quality of broadcasted radio waves of each broadcasting station uniform in desirable sound quality. <P>SOLUTION: The broadcasting receiver includes: a tuning circuit 1 for tuning in to a broadcasted radio wave; a demodulation circuit 1 for demodulating the broadcasted radio wave tuned in to by the tuning circuit 1 to a sound signal; and an adjusting means 10a for adjusting a frequency characteristic of the sound signal demodulated by the demodulation circuit 1, and outputs sound based on the frequency characteristic adjusted by the adjusting means 10a. A detection circuit 2 for detecting a modulation factor of the broadcasted radio wave and setting means 4 and 10a for setting the frequency characteristic of a sound signal to be demodulated from the broadcasted radio wave in accordance with the modulation factor detected by the detection circuit are provided, and the adjusting means 10a adjusts a frequency characteristic to the frequency characteristic set by the setting means 4 and 10a. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an improvement of a broadcast receiving apparatus such as an AM radio receiver, and more particularly to a broadcast receiving apparatus suitable for application to an in-vehicle radio mounted on a vehicle.

In a conventional AM radio receiver, the reception frequency is set by a user's manual operation or by an “auto preset” function. The “auto-preset” function automatically scans the broadcast radio frequency at the time of setting (preset), stores the frequency of the broadcast radio wave with a field strength greater than a predetermined value in the memory, and assigns a channel selection button to each frequency. . Thereby, the user can select a channel by pressing a channel selection button.
Patent Document 1 discloses a volume adjustment device that automatically corrects a volume difference between channels due to a difference in the degree of modulation of a broadcasting station when a channel is selected.

Patent Document 2 discloses a satellite broadcast receiver that can receive at an appropriate volume when changing channels even in multi-satellite reception. Patent Document 3 discloses a television receiver that can maintain optimum image quality and volume for each broadcast station or video input when switching between broadcast stations or video inputs.
Japanese Patent Laid-Open No. 7-2222078 JP-A-8-79652 JP 9-37174 A

  AM (amplitude modulation) broadcasting is characterized in that the depth (magnitude) of the modulation degree of the transmission radio wave differs from broadcast station to broadcast station, whereby the sound quality of the radio wave received by the AM radio receiver differs from broadcast station to broadcast station. For example, the sound quality of a received radio wave from a broadcast station with a deep (large) modulation degree may be heard with a feeling that the middle and low frequencies are thick and the sound is somewhat muffled. On the other hand, the sound quality of a received radio wave from a broadcast station with a shallow (small) modulation degree may be heard with the mid-low range being thin and the high range being emphasized.

In the conventional AM radio receiver, as described above, the frequency and the channel selection button are associated with each other and stored in the memory and preset, so each broadcast station can be used regardless of whether the modulation level is deep or shallow. The frequency of the broadcast radio wave is stored in the memory and is selected by the channel selection button, and there is a problem in that the sound quality is different for each broadcast station. Therefore, in some cases, every time a channel is selected, there is a problem that the frequency characteristic must be adjusted by a frequency characteristic adjustment knob (bus adjustment knob / treble adjustment knob) or the like.
The present invention has been made in view of the circumstances as described above, and a broadcast receiving device that is easy to listen to without having to perform sound quality correction every time a channel is selected, with the sound quality of broadcast radio waves for each broadcast station being equal to the preferred sound quality. The purpose is to provide.

  A broadcast receiving apparatus according to a first aspect of the present invention includes a tuning circuit that tunes to a broadcast radio wave, a demodulation circuit that demodulates the broadcast radio wave tuned by the tuning circuit into an audio signal, and adjusts frequency characteristics of the audio signal demodulated by the demodulation circuit And a detecting circuit for detecting a modulation degree of the broadcast radio wave, and a demodulated from the broadcast radio wave in a broadcast receiving apparatus for outputting sound based on the frequency characteristic adjusted by the adjusting means. Setting means for setting a frequency characteristic of an audio signal according to a modulation degree detected by the detection circuit, and the adjusting means is adapted to adjust the frequency characteristic set by the setting means. To do.

  In this broadcast receiving apparatus, the tuning circuit tunes to the broadcast radio wave, and the demodulation circuit demodulates the broadcast radio wave tuned by the tuning circuit into an audio signal. The adjusting means adjusts the frequency characteristic of the audio signal demodulated by the demodulation circuit, and outputs sound based on the frequency characteristic adjusted by the adjusting means. The detection circuit detects the modulation degree of the broadcast radio wave, and the setting means sets the frequency characteristic of the audio signal demodulated from the broadcast radio wave according to the modulation degree detected by the detection circuit. The adjusting means adjusts to the frequency characteristic set by the setting means.

  A broadcast receiving apparatus according to a second aspect of the invention is a storage means for storing the frequency of a broadcast radio wave to be received, a tuning circuit that is tuned to a broadcast radio wave having a frequency that is stored in the storage means, A broadcast receiving apparatus, comprising: a demodulating circuit that demodulates into an audio signal; and an adjusting unit that adjusts a frequency characteristic of the audio signal demodulated by the demodulating circuit, and that outputs sound based on the frequency characteristic adjusted by the adjusting unit. And a setting circuit that sets a frequency characteristic of an audio signal demodulated from the broadcast radio wave according to the modulation degree detected by the detection circuit, and The means stores the frequency characteristics set by the setting means in correspondence with the frequency of the broadcast radio wave, and when the tuning circuit is tuned to the frequency, the adjusting means corresponds to the frequency. Characterized in that are no in order to adjust the frequency characteristic obtained by.

  In this broadcast receiving apparatus, the storage means stores the frequency of the broadcast radio wave to be received, and the tuning circuit tunes to the broadcast radio wave of the frequency stored in the storage means. The demodulating circuit demodulates the broadcast radio wave tuned by the tuning circuit into an audio signal, the adjusting means adjusts the frequency characteristic of the audio signal demodulated by the demodulating circuit, and outputs the sound based on the frequency characteristic adjusted by the adjusting means. The detection circuit detects the modulation degree of the broadcast radio wave, and the setting means sets the frequency characteristic of the audio signal demodulated from the broadcast radio wave according to the modulation degree detected by the detection circuit. The storage means stores the frequency characteristics set by the setting means in correspondence with the frequency of the broadcast radio wave, and when the tuning circuit tunes to the stored frequency, the adjustment means corresponds to the stored frequency. Adjust to frequency characteristics.

  In the broadcast receiving apparatus according to a third aspect of the invention, the setting means should be adjusted to a frequency characteristic in which the high frequency band (low frequency band) is attenuated according to the shallowness (depth) of the modulation degree. It is characterized by.

  In this broadcast receiving apparatus, the setting means adjusts the frequency characteristic to which the high-frequency part is attenuated according to the shallowness of the modulation degree, and adjusts to the frequency characteristic to which the low-frequency part is attenuated according to the depth of the modulation degree. To do.

  In the broadcast receiving apparatus according to a fourth aspect of the present invention, when the modulation degree is shallower than the first modulation degree, the setting means adjusts the frequency characteristics by attenuating a high frequency part according to the shallowness, and the modulation degree is When deeper than the second modulation degree, which is deeper than the first modulation degree, the low-frequency part is adjusted to a frequency characteristic attenuated according to the depth.

  In this broadcast receiving apparatus, when the modulation degree detected by the detection circuit is shallower than the first modulation degree, the setting means adjusts the frequency characteristics by attenuating the high frequency region according to the shallowness, and the modulation degree is When the depth is deeper than the second modulation depth, which is deeper than the first modulation depth, the frequency characteristics are adjusted to attenuate the low frequency portion according to the depth.

  According to the broadcast receiving apparatus according to the first aspect of the present invention, it is possible to realize a broadcast receiving apparatus in which the sound quality of broadcast radio waves for each broadcast station is matched to a preferable sound quality and is easy to listen without performing sound quality correction each time a channel is selected. Further, in the case of an in-vehicle radio, it is possible to achieve a preferable sound quality even when driving to a remote place and receiving a broadcast wave that is not normally received, and it is possible to make it easy to listen without performing sound quality correction. If it is not an in-vehicle radio, there is a radio receiver that stores a reception frequency list that can be received for each region in the ROM, and sets a reception frequency list for each region, but when such a radio receiver also receives, The sound quality can be improved, and listening can be facilitated without correcting the sound quality.

  According to the broadcast receiving apparatus according to the second aspect of the invention, by presetting the reception frequency, the sound quality of the broadcast radio wave for each broadcast station is matched to a preferable sound quality, and it is easy to listen without performing sound quality correction each time a channel is selected. A device can be realized. In addition, in the case of in-vehicle radios, presetting the reception frequency when driving to a remote location can improve the sound quality even when receiving broadcast waves that are not normally received, and can be listened to without performing sound quality correction. It can be made easier.

  According to the broadcast receiving apparatus according to the third aspect of the present invention, it is possible to realize a broadcast receiving apparatus in which the sound quality of broadcast radio waves for each broadcast station is matched to a preferable sound quality, and it is easy to listen without performing sound quality correction each time a channel is selected. Further, since the high frequency range portion or the low frequency range portion is attenuated according to the modulation degree, the noise can be reduced as compared with the case where the low frequency range portion or the high frequency range portion is amplified and the noise is also amplified. .

  According to the broadcast receiving apparatus of the fourth aspect of the invention, when the modulation degree is shallower than the first modulation degree, the audio signal is adjusted to the frequency characteristic in which the high frequency region is attenuated according to the shallowness, and the modulation degree is When deeper than the second modulation degree, which is deeper than the first modulation degree, the audio signal is adjusted to a frequency characteristic in which the low frequency range is attenuated according to the depth, and the sound quality of the broadcast radio wave is preferable. Since the frequency characteristic is not adjusted at a modulation depth shallower than the modulation degree, the sound quality of the broadcast radio wave for each broadcast station is matched to a preferable sound quality, and a broadcast receiving device that is easy to listen without performing sound quality correction every time a channel is selected is realized. I can do it. Further, since the high frequency range portion or the low frequency range portion is attenuated according to the modulation degree, the noise can be reduced as compared with the case where the low frequency range portion or the high frequency range portion is amplified and the noise is also amplified. . Also, by making the first modulation factor and the second modulation factor variable, the sound quality of the broadcast radio wave can be matched to the user's favorite sound quality.

Hereinafter, the present invention will be described with reference to the drawings illustrating embodiments thereof.
FIG. 1 is a block diagram showing a configuration example of an AM radio receiver which is an embodiment of a broadcast receiving apparatus according to the present invention. This AM radio receiver has, as an operation unit 8, a power button 11, a volume adjustment knob 12, a bus adjustment button 14, a treble adjustment button 15, an auto preset button 16, a bus adjustment mode / treble adjustment mode, etc. Mode selector switch 17 and a channel selection button 18, and the display unit 9 includes a display lamp 20 using an LED element, and a liquid crystal display 19 for displaying a reception frequency and the like. The display unit 9 and each unit to be described later are controlled by the microcomputer 4 in accordance with an operation on the operation unit 8 by the user.
The microcomputer 4 has a built-in memory 7 for storing the frequency of the broadcast radio wave to be received set by the microcomputer 4 during auto-preset by operating the auto-preset button 16.

  The tuner unit 1 ((example) MITSUMI ELECTRIC; FAE376-A01 / E01 / J01) has a frequency stored in the memory 7 according to the operated channel selection button 16 when the channel selection button 16 is operated. And a demodulating circuit for demodulating the tuned broadcast radio wave into an audio signal, and a voltage indicating the electric field strength of the demodulated signal demodulated by the demodulator circuit is output to the S meter. Output as. The S meter output is given to the microcomputer 4, and the microcomputer 4 detects the modulation degree of the broadcast radio wave by the S meter output.

  The preamplifier unit 3 (including an electronic volume, a DSP, an analog IC, etc.) has a volume control unit 10 that adjusts the output level of the audio signal based on the output of the microcomputer 4, and the frequency characteristic of the audio signal demodulated by the tuner unit 1. And a frequency characteristic adjusting unit 10 a that adjusts based on the output of the microcomputer 4. The audio signal adjusted by the preamplifier unit 3 is amplified by the main amplifier unit 5 (amplifier), and the amplified audio signal is converted into audio by the speaker 6 and output.

  The microcomputer 4 detects that the auto-preset button 16 has been operated, causes the tuner unit 1 to automatically scan the frequency of the broadcast radio wave, and stores the frequency of the broadcast radio wave whose electric field strength is greater than a predetermined value in the memory 7. At the time of auto-preset in which the channel selection button 18 is assigned to each frequency, each frequency characteristic corresponding to each detected modulation degree is stored in the memory 7 in association with the frequency of the broadcasting station. The frequency characteristic corresponding to the modulation degree is stored in the memory 7 as a table corresponding to the modulation degree as a setting state of the frequency characteristic adjusting unit 10a.

Hereinafter, an example of the operation at the time of auto-preset of the radio receiver having such a configuration will be described with reference to the flowchart of FIG.
When the auto preset button 16 is operated to enter the auto preset operation, the microcomputer 4 causes the tuner unit 1 to automatically scan for broadcast radio waves and searches for radio waves having a field intensity greater than a predetermined value. When the electric field intensity is tuned to a radio wave larger than a predetermined value, the channel selection button 18 is automatically assigned to the tuned frequency (S2).

On the other hand, the microcomputer 4 detects the modulation degree of the radio wave having the tuned frequency (S4), and determines whether the detected modulation degree is deeper or shallower than the predetermined first and second modulation degrees (S6).
When the detected modulation degree is shallower than the first modulation degree (for example, 60%) (S6), the microcomputer 4 is a frequency characteristic diagram showing the high frequency region of the frequency characteristic of the radio signal of the radio wave in FIG. As indicated by an arrow A, the standard frequency characteristic is attenuated according to the depth of modulation (the more it is shallower, the more it is attenuated) (S10). Next, the frequency characteristic obtained by attenuating the high frequency region is stored and set in the memory 7 in correspondence with the frequency (S2) that is tuned and assigned to the channel selection button 18 (S12). It is determined whether or not automatic scanning has been completed (S14).

  When the detected modulation degree is deeper than the second modulation degree (for example, 80%) deeper than the first modulation degree (S6), the microcomputer 4 determines the low frequency range portion of the frequency characteristic of the audio signal of the radio wave as shown in FIG. As shown by an arrow B in FIG. 4, the standard frequency characteristic is attenuated according to the depth of the modulation degree (the deeper the attenuation, the more the frequency characteristic is attenuated) (S8). Next, the frequency characteristic obtained by attenuating the low frequency region is stored and set in the memory 7 in correspondence with the frequency (S2) that is tuned and assigned to the channel selection button 18 (S12). It is determined whether or not automatic scanning has been completed (S14).

  When the detected modulation degree is deeper than the first modulation degree and shallower than the second modulation degree (S6), the microcomputer 4 does not change the frequency characteristics of the audio signal of the radio wave and does not change the standard frequency. The characteristics are tuned and correspond to the frequency (S2) assigned to the channel selection button 18, stored in the memory 7 and set (S12), and it is determined whether or not the automatic scanning of the AM radio broadcast wave has been completed (S12). S14).

  The microcomputer 4 returns when the automatic scanning of the AM broadcast wave is completed (S14). When the automatic scanning has not been completed, the tuner unit 1 automatically scans the broadcast radio wave, searches for a radio wave whose electric field strength is greater than a predetermined value, and when the electric field strength is tuned to a radio wave greater than the predetermined value, the tuned frequency The channel selection button 18 is automatically assigned to (S2).

In this AM radio receiver, when the user operates any one of the channel selection buttons 18, the microcomputer 4 reads out the frequency and frequency characteristics corresponding to the operated channel selection button 18 from the memory 7, and reads the frequency of the read frequency. The tuning circuit of the tuner unit 1 is tuned to the radio wave. The demodulator circuit of the tuner unit 1 demodulates the tuned radio wave into an audio signal and gives it to the electronic volume 3.
On the other hand, the microcomputer 4 sets the read frequency characteristic in the frequency characteristic adjusting unit 10a.

  The preamplifier unit 3 adjusts the frequency characteristic of the audio signal given from the demodulation circuit by the frequency characteristic adjustment unit 10a, adjusts the volume of the audio signal by the volume adjustment unit 10, and supplies it to the main amplifier unit 5, The unit 5 amplifies the given audio signal and outputs it from the speaker 6 as audio.

In the above-described embodiment, when the modulation degree is shallower than the first modulation degree, the high frequency range portion of the audio signal is attenuated according to the shallowness of the modulation degree, and when the modulation degree is deeper than the second modulation degree, The low frequency range of the signal is attenuated according to the depth of the modulation, but when it is shallower than the first modulation, the high frequency is attenuated uniformly regardless of the depth and is deeper than the second modulation May attenuate the bass region uniformly regardless of the depth.
In the above-described embodiment, the high frequency region (low frequency region) is attenuated according to the shallowness (depth) of the modulation degree, but conversely, the shallowness (depth) of the modulation degree. Accordingly, the low frequency band (high frequency band) can be adjusted to the amplified frequency characteristic.

  In the above-described embodiment, the frequency of the broadcast radio wave and the frequency characteristic of the audio signal corresponding to the detected modulation degree are associated with each other and stored in the memory 7 during auto-preset. Instead, it is possible to detect the modulation degree every time the broadcast radio wave is tuned, and to set the frequency characteristic of the audio signal corresponding to the detected modulation degree in the frequency characteristic adjustment circuit.

  As a result, a radio frequency receiver that does not have an auto-preset function and stores a reception frequency list that can be received for each region in a ROM and sets a reception frequency list for each region can receive received radio waves with a preferable sound quality. It can be made easy to listen without sound quality correction. In addition, even with a radio receiver to which neither the auto-preset function nor the above-described ROM is added, the received radio wave can have a preferable sound quality and can be easily listened to without performing sound quality correction.

  As described above, it is possible to realize a radio that can easily listen to the received radio wave with a preferable sound quality regardless of the reception status at the reception point.

It is a block diagram which shows the structural example of AM radio receiver which is embodiment of the broadcast receiver which concerns on this invention. It is a flowchart which shows the example of operation | movement of AM radio receiver which is embodiment of the broadcast receiver which concerns on this invention. It is a frequency characteristic figure of the audio signal for demonstrating operation | movement of AM radio receiver which is embodiment of the broadcast receiver which concerns on this invention.

Explanation of symbols

1 Tuner part 3 Preamplifier part (electronic volume)
4 Microcomputer 5 Main amplifier (amplifier)
6 Speaker 7 Memory (memory means)
8 Operation part 9 Display part 10 Volume control part 10a Frequency characteristic adjustment part 16 Auto-preset button 18 Channel selection button 21 Antenna

Claims (4)

A tuning circuit that tunes to a broadcast radio wave; a demodulation circuit that demodulates the broadcast radio wave tuned by the tuning circuit into an audio signal; and an adjustment unit that adjusts a frequency characteristic of the audio signal demodulated by the demodulation circuit. In a broadcast receiving apparatus that is designed to output sound based on the frequency characteristics adjusted by
A detection circuit for detecting a modulation degree of the broadcast radio wave, and setting means for setting a frequency characteristic of an audio signal demodulated from the broadcast radio wave according to the modulation degree detected by the detection circuit, The broadcast receiving apparatus is characterized in that the frequency characteristic set by the setting means is adjusted. Storage means for storing the frequency of the broadcast radio wave to be received, a tuning circuit for tuning to the broadcast radio wave of the frequency stored in the storage means, a demodulation circuit for demodulating the broadcast radio wave tuned by the tuning circuit into an audio signal, In the broadcast receiving apparatus, the demodulating circuit includes an adjusting unit that adjusts the frequency characteristic of the demodulated audio signal, and the audio signal is output based on the frequency characteristic adjusted by the adjusting unit.
A detection circuit for detecting a modulation degree of the broadcast radio wave, and setting means for setting a frequency characteristic of an audio signal demodulated from the broadcast radio wave according to the modulation degree detected by the detection circuit, and the storage means The frequency characteristic set by the setting means is stored in correspondence with the frequency of the broadcast radio wave, and when the tuning circuit is tuned to the frequency, the adjusting means adjusts to the frequency characteristic corresponding to the frequency. A broadcast receiver characterized in that it is suitable.   The broadcast receiving apparatus according to claim 1 or 2, wherein the setting means is adapted to adjust the frequency characteristics by attenuating a high frequency part (low frequency part) according to a shallowness (depth) of the modulation degree.   When the modulation degree is shallower than the first modulation degree, the setting means adjusts the frequency characteristics by attenuating the high frequency region according to the shallowness, and the modulation degree is a second deeper than the first modulation degree. 3. The broadcast receiving apparatus according to claim 1, wherein when the depth is greater than the modulation degree, the frequency characteristic is adjusted to a frequency characteristic in which the low frequency band is attenuated according to the depth.

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