JPH04235419A - Receiver - Google Patents

Abstract

PURPOSE:To offer the receiver which receives the accurate road information, etc., in highways without the need of the operations by a driver on the condition of turning on the power of the receiver. CONSTITUTION:The electric field intensity of received radio wave is detected by a level adjustment circuit 22 and a level selection circuit 23. When the detected electric field intensity is higher than the prescribed level, the reception permission signal is outputted to a supply power control circuit 24. In the supply power control circuit 24, power supply is supplied to a low frequency amplifier circuit 12 and power amplifier circuits 13, 14 in accordance with this reception permission signal. When the detected electric field intensity is lower than the prescribed level, the supply power control circuit 24 controls so that the power not be supplied.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a receiving device that produces no sound outside the reception area of broadcasting station radio waves, and relates to a receiving device suitable for receiving weak broadcasts such as those broadcasting road information on expressways, for example.

0002

2. Description of the Related Art Drivers who drive on general roads or expressways are always aware of the road conditions ahead of them when driving on the road. However, conventionally, such road information has been obtained by receiving common traffic information and guidance broadcast at regular intervals during general radio broadcasts using general radio.

[0003] Alternatively, on expressways and the like, the only way to know the information is to look at the electronic information notice board installed above the road. Alternatively, recently, local radio broadcasting stations using a small amount of electricity using a specific frequency (currently 1620 KHz) have been installed in tunnels, areas where stagnation is expected, or places where accidents occur frequently, and It has become possible to listen to road information specific to these areas and guidance information to prevent accidents only in certain sections.

[0004] In such local broadcasting of road information, etc., as shown in FIG. ) etc., this antenna 101 transmits a weak radio wave to the extent that it does not affect other areas, this is received by the receiving antenna 112 of the car 111 traveling on the road, and the in-vehicle receiver 113 receives the acoustic signal. I was listening to it instead.

[0005] However, the existence of this local information was only displayed on signboards placed on the side of the road or on top of the road. Therefore, in order for the driver to receive this local broadcast, the driver must always pay attention to the road signs. When a road sign is found, the radio receiver for receiving a general radio station is turned on, and the radio reception frequency is retuned to the frequency for receiving this local broadcast.
It was necessary to either receive local broadcasts or to keep the radio switched on and tuned to the local broadcast reception frequency (for example, 1620 KHz).

[0006]

[Problem to be Solved by the Invention] However, in conventional radio receivers that receive radio waves from general broadcasting stations, when the distance from the broadcasting station increases and the electrolytic strength of the received radio waves decreases, the automatic gain in the receiver circuit It is configured to increase reception sensitivity by operating an adjustment (AGC) circuit to adjust the amplification gain of the intermediate frequency.

For this reason, when the receiving sensitivity is increased in this manner, the generation of noise equivalent to detuning noise is unavoidable, making it extremely difficult to hear. If the radio is always turned on and tuned to the receiving frequency of local broadcasting (for example, 1620 KHz), the user will suffer from the above-mentioned out-of-tuning noise. Therefore, for example, when the user is out of the reception area, the volume is turned down, and when the user enters the reception area and the reception is in good condition, the user has to turn the volume up, which is a troublesome operation.

[0008] These power on/off operations, tuning operations, volume adjustment operations, and the like are all troublesome operations during driving. For this reason, urgent local broadcasts are often not received, which is an undesirable situation from the viewpoint of preventing road congestion and accidents. Some also had a muting function added to prevent noise from being output from the speaker. However, it simply does not output the audio signal, and the power consumption remains the same. For this reason, it is good when the power is supplied from a general commercial power source, but when the radio is installed in a car or is battery-powered, it consumes a large amount of power during this silent state. This was a big problem.

[0009]

[Means for Solving the Problems] The present invention has been made for the purpose of solving the above-mentioned problems, and has the following configuration as a means for solving the above-mentioned problems. That is, a receiving means receives broadcasting station radio waves, a frequency converting means converts the radio waves received by the receiving means into an intermediate frequency signal of a specific frequency and amplifies it, and detects the converted frequency by the frequency converting means to convert it into an audible frequency signal. A conversion means for converting into a signal, an amplification means for power amplifying the audio frequency signal converted by the conversion means, an output means for converting the amplified signal of the amplification means into an acoustic signal and outputting it, and conversion by the frequency conversion means. Reception level monitoring means for detecting the electric field strength of the received radio waves by the receiving means based on the signal and monitoring whether the detected electric field strength is at least a predetermined level; and a power-off means for turning off at least the driving power of the amplification means when the amplification means is not detected.

[0010] Alternatively, a receiving means for receiving broadcasting station radio waves of a predetermined frequency, a modulating means for modulating the radio waves received by the receiving means into an audio frequency signal, and a sound outputting means for power amplifying the modulated signal by the modulating means. an amplification means for supplying the radio wave to the receiving means; a reception level monitoring means for detecting the electric field strength of the received radio wave at the receiving means and monitoring whether the detected electric field strength is equal to or higher than a predetermined level;
The apparatus further includes a power-off means for turning off at least a driving power source for the amplification means when the reception level monitoring means does not detect the field strength of the received radio waves of a predetermined level or higher.

Alternatively, the apparatus further includes a display means for displaying the status of the apparatus, and the power off means also turns off the power of the display means when the reception level monitoring means does not detect a reception level equal to or higher than a predetermined reception level.

0012

[Function] With the above configuration, it is possible to provide a receiver that suppresses the acoustic output that is difficult to hear in areas other than the receiving area of the broadcasting station, and minimizes the power consumption when there is no acoustic output. Further, troublesome operations for reception can be made unnecessary.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

[0014]

[First Embodiment] FIG. 1 is a block diagram of a radio receiver suitable for receiving expressway information, which is a receiving device according to an embodiment of the present invention, and FIGS. 2 and 3 show the embodiment shown in FIG. 1. FIG. 3 is a detailed circuit diagram of the receiver. In Figures 1 to 3, 1 is a broadcasting station (
2 is a tuning circuit that selects only the radio waves of a specific frequency from among the radio waves of many frequencies received by the antenna 1 and sends them to the frequency converter 3; , 3 is a frequency conversion circuit that converts and outputs the selected frequency from the tuning circuit 2, and a local oscillation circuit 4 that oscillates an intermediate frequency (for example, 455 KHz) that is a frequency signal that is a certain frequency higher than the selected frequency; It is composed of a mixing circuit 5 and the like that mixes the signal from the local oscillation circuit 4 and the signal from the tuning circuit 2.

Reference numeral 6 denotes an intermediate frequency amplification circuit composed of two stages of IF amplifiers (intermediate frequency amplification amplifiers) 7 and 8, and 9 detects an AM-modulated high frequency signal from the intermediate frequency amplification circuit to convert it into an audio frequency signal. 10 is an automatic gain adjustment (AGC) circuit that monitors the output level from the detection circuit 9 and controls the gain of the intermediate frequency amplification circuit so that the detected output is at a constant level; 11 is a signal from the speaker 15; 12 is a low frequency amplification circuit that amplifies the output audio signal; 13 and 14 are amplified by the power of the audio signal amplified by the low frequency amplification circuit 12, and the speaker 1
5 is a power amplification circuit for outputting power, and 15 is a speaker.

Further, 21 is a detection circuit that detects the output of the intermediate frequency amplification circuit, and 22 is a level adjustment that monitors the detection output level from the detection circuit 21 and outputs an output signal when the level exceeds a certain level. This circuit can be adjusted to output at any received field strength level using the included variable resistor. 23 is a level selection circuit having a function of displaying whether or not there is an output from the level adjustment circuit 22 using an indicator light emitting diode; 24 is a level selection circuit 2;
This is a power supply control circuit that controls whether or not to supply power to the low frequency amplifier circuit 12 and power amplifier circuits 13 and 14 according to the output signal of No. 3.

The operation of this embodiment having the above configuration will be explained below. The antenna 1 to the speaker 15 have substantially the same configuration as a general radio receiver, and detailed description thereof will be omitted. In this embodiment, a detection circuit 21 to a power supply control circuit 24 are further added to the radio receiver circuit described above. By providing the above-described circuit configuration unique to this embodiment, the output from the intermediate frequency amplification circuit 6 is input to the detection circuit 21 and converted into a DC voltage level signal proportional to the electric field strength of the received radio wave. The converted signal is then sent to the level adjustment circuit 22. The level adjustment circuit 22 adjusts the variable resistor and sends an output signal to the level selection circuit 23 when the field strength of the received radio wave exceeds an arbitrary adjusted field strength level.

When the level selection circuit 23 receives the output from the level adjustment circuit, it causes the indicator light emitting diode to emit light to display the reception status, and outputs the reception ready status to the power supply control circuit 24. The power supply control circuit 24 supplies power to the low frequency amplification circuit 12 and the power amplification circuits 13 and 14 when there is an output from the level selection circuit 23, and controls so that no power is supplied when there is no output.

For this reason, using the receiver of this embodiment, for example, the receiving frequency may be changed to 1, which is the receiving frequency of expressway information, etc.
By adjusting the frequency to 620 KHz, there is no sound outside the traffic information receiving area on the expressway, preventing the output of harsh noise sounds, and the low frequency amplifier circuit 12 and the power amplifier circuit 13, which consume a large amount of power, 14 can be turned off to reduce unnecessary power consumption.

[0020] With the above configuration, power consumption outside the reception area can be kept low, and even in a vehicle-mounted radio receiver, the device can remain powered on. When the car enters the receiving area for traffic information on the expressway and the field strength of the received radio waves increases, the low frequency amplifier circuit 12 and the power amplifier circuits 13 and 14 are automatically turned on, and the received information is transmitted to the speaker 15. It can output more sound. Therefore, the user can receive road information, etc. without having to set the radio in a hurry after seeing a road sign.

[0021] When the car moves out of the traffic information reception area on the expressway, it goes into a standby state again and turns off the low frequency amplification circuit 12 and the power amplification circuits 13 and 14, which consume a large amount of power. Reduce unnecessary power consumption. For example, with the circuit configurations shown in Figures 2 and 3, the current consumption is kept extremely low (2 m
Grade A) Since the sound is output only in the reception area, current consumption increases, and the broadcast radio waves can be received and output from the speaker 15.

[0022] In this way, it is possible to realize a receiver that is always energized and that automatically outputs audio when it enters the reception area of an expressway. As explained above, according to this embodiment, power is always on, and when the user is outside the receiving area of local broadcasts such as expressway traffic information, power is supplied to only the minimum necessary components and consumed. When you enter the local broadcast reception area by minimizing the power, power is automatically supplied to all components and reception begins, and when you leave the reception area, the switch is automatically turned off.
Power consumption can be minimized.

[0023] Therefore, the following effects can be achieved. ■Power consumption of the radio receiver can be kept to a minimum even when the receiver is turned on. ■The driver can always grasp the exact road condition without having to perform troublesome operations such as turning on/off the power switch, tuning, and adjusting the volume.

[0024] Also in this case, no noise is generated outside the reception area.

[0025]

[Second Embodiment] The above description has been made regarding a configuration in which a detection circuit 21 to a power supply control circuit 24 are further added to a general radio receiver for receiving radio broadcasts. however,
In the above configuration, when tuning to a frequency for receiving road information, general radio broadcasting cannot be received at the same time.

[0026] Therefore, a second embodiment of the present invention will be described below, which is configured to be able to receive general radio broadcasts as well as local broadcasts such as road information. The second embodiment is a receiving device that can be introduced or installed even when a car radio or the like is installed in a car, etc. By sharing existing speakers, etc., local broadcasting can be performed with a minimum configuration. It is possible to receive.

FIG. 4 is a block diagram showing the configuration of a second embodiment according to the present invention. In the second embodiment, a radio receiver 40 and a receiving antenna 41 for receiving general medium wave radio broadcasting stations, Road information on expressways or similar local radio broadcasts using minute power at a specific frequency (currently 1620 KHz) in tunnels, areas where stagnation is expected, or places where accidents occur frequently. It is equipped with a radio receiving section 45 and an antenna 46 that are tuned to receive local broadcast stations, and the speaker 42 is configured to be shared.

The radio receiving section 45 of the second embodiment has substantially the same configuration as the receiver of the first embodiment described above. The radio receiving section 45 differs from the first embodiment in that the tuning circuit 2 is set to a specific frequency for receiving local broadcasts (for example, currently 1620 KHz), and it does not include the speaker 15, so it is not equipped with a general radio receiver. It can be used in common with the radio receiver 40, and can be previewed together with broadcasts received from the radio receiver 40.

However, this tuning circuit 2 is also not configured such that the tuning frequency cannot be changed, but is configured so that there is no need to change the tuning, and therefore there is no need to normally operate it. With the above configuration, as shown in FIG. 6, for example, when a moving car or the like enters the local broadcast reception area and the electric field strength reaches a certain level, the low frequency amplification circuit of the radio reception unit 45 automatically , power is supplied to the power amplifier circuit, etc., and local broadcast reception information such as road information is transmitted to the speaker 4.
Output from 2. Therefore, the driver can receive this local broadcast without any operation.

[0030] Also in this case, the radio receiver 40 can operate completely separately from the radio receiving section 45,
For example, desired radio broadcasts can be received. When a local broadcast reception area is reached while a general radio broadcast is being received, the local broadcast, such as road information, is mixed with the general radio broadcast being received and output from the speaker 42. become.

The volume of the radio receiving section 45 can also be adjusted, and in such a case, the output volume of the radio receiving section 45 may be adjusted depending on which one to listen to with priority. As explained above, according to the second embodiment, it is possible to receive local broadcasts as well as general radio broadcasts, and even in such a case, receiving local broadcasts does not require any special operations, so the driver does not need to perform any special operations. It is configured so that it can receive necessary road information and other information without placing a heavy load on the system.

[0032]

[Other Embodiments] In the second embodiment described above, an example was explained in which general radio broadcasts and local broadcasts such as road information are mixed and output from the speaker 42. Of course, it is within the scope of the present invention to control the local broadcast reception results to be output only when general broadcasts are not being received, instead of outputting them. In this case, if the radio receiving unit 45 is configured to detect when the radio receiver 40 is powered on (or the radio receiving unit 45 is powered on when the radio receiver 40 is powered off), two broadcast stations can be detected. This prevents the received information from being mixed and output.

Alternatively, as shown in FIG. 5, a switch 50 is provided on the speaker cable from the radio receiver 45 for local broadcast reception to the speaker 42, and when the radio receiver 40 is powered on, the radio receiver The switch 50 may be turned off so that the local broadcast reception result is not sent to the speaker 42 when the speaker 40 is receiving the broadcast. The switch 50 may be switched, for example, by opening the contacts of the switch 50 at the same time as the radio receiver 40 is powered on.

Furthermore, instead of giving priority to general radio broadcasts, it is also possible to give priority to reception of local broadcasts. In this case, a switch 50 having the configuration shown in FIG. You just need to know how to configure it to turn off the switch.

According to the embodiment described above, it is possible to automatically listen to local broadcasts such as road information without any special operation, and it is also possible to listen to only one reception result if necessary. can.

[0036]

As explained above, according to the present invention, when the user is outside the receiving area of the broadcast waves of a broadcasting station, power consumption is minimized by supplying power to only the minimum necessary components. When entering the broadcast reception area, power is automatically supplied to all components and reception begins, and when leaving the reception area, broadcast reception is automatically shut off, minimizing power consumption.

[0037] Therefore, by using the receiver of the present invention to receive broadcasting stations that transmit with weak output, such as road information on expressways, the driver does not have to operate the receiver blinking while the receiver is turned on. Accurate road conditions can be grasped at all times without the need for a vehicle.

[Brief explanation of the drawing]

FIG. 1 is a block configuration diagram of an embodiment according to the present invention;

FIG. 2 is a detailed circuit diagram of the antenna 1 to speaker 15 portion shown in FIG. 1;

[Fig. 3] Detection circuit 21 to power supply control circuit 2 shown in Fig. 1
Detailed circuit diagram of 4 parts,

FIG. 4 is a block diagram showing the configuration of a second embodiment according to the present invention;

FIG. 5 is a block diagram of another embodiment according to the present invention;

[
FIG. 6 is a diagram for explaining a local broadcast reception state in a car on an expressway or the like.

[Explanation of symbols]

1, 41, 46 antenna, 2 tuning circuit, 3 frequency conversion circuit 6 intermediate frequency amplification circuit, 9, 21 detection circuit, 10 automatic gain adjustment (AGC) circuit, 12
low frequency amplification circuit, 13, 14 power amplification circuit, 15, 42 speaker, 22 level adjustment circuit, 23 level selection circuit, 24 power supply control circuit 40 radio receiver 45 radio reception section 50 switch

Claims (3)

[Claims] Claim 1: receiving means for receiving radio waves from a broadcasting station; frequency converting means for converting and amplifying radio waves received by the receiving means into an intermediate frequency signal of a specific frequency; and detecting the converted frequency by the frequency converting means. a converting means for converting the converted audio frequency signal into an audio frequency signal, an amplifying means for power amplifying the converted audio frequency signal by the converting means, an output means for converting the amplified signal of the amplifying means into an acoustic signal and outputting it, and the frequency converter. reception level monitoring means for detecting the electric field strength of the received radio wave by the receiving means based on the converted signal by the means, and monitoring whether the detected electric field strength is at least a predetermined level; A receiving device comprising: power-off means for turning off at least a driving power source for the amplification means when the electric field strength of a received radio wave is not detected. 2. Receiving means for receiving broadcasting station radio waves of a predetermined frequency, modulation means for modulating the radio waves received by the receiving means into an audio frequency signal, and sound output means for power amplifying the modulated signal by the modulation means. an amplification means for supplying the radio wave to the receiving means, and a reception level monitoring means for detecting the electric field strength of the received radio wave at the receiving means and monitoring whether the detected electric field strength is equal to or higher than a predetermined level;
A receiving device characterized in that it comprises power-off means for turning off at least a driving power source for said amplification means when said reception level monitoring means does not detect a field strength of received radio waves of a predetermined level or higher. 3. The receiving device according to claim 1 or 2, further comprising display means for displaying the status of the device, and the power-off means is configured to turn off the power when the reception level monitoring means does not detect a predetermined reception level or higher. A receiving device characterized in that the power of the receiver is also turned off.