JPH03117930A - On-vehicle diversity receiver - Google Patents

Abstract

PURPOSE:To reduce the degradation in sound quality accompanied with antenna switching by not performing the diversity operation in principle at the time of stopping a vehicle when receiver circumstance is less changed. CONSTITUTION:When the vehicle stops, a detection signal (d) of a running mode detector 17 goes to logical '1'. If a signal (e) is logical '1' at this time, a control signal (c) outputted from an AND gate 19 goes to logical '1' to stop the diversity operation. That is, the high sound band of the sound output is cut at each time of diversity operation to suppress the occurrence of noise while the vehice is run; but when the vehicle is stopped, the diversity operation is stopped to eliminate the cause of the occurrence of diversity noise. Therefore, it is unnecessary to cut the high sound band. Thus, the sound quality is improved.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a beam-mounted diversity receiving device.

(Prior Art) Fig. 5 shows an on-vehicle diversity receiving device using a conventional lj on-board television receiver as an example.

In Figure 5, 1 to 4 are placed at the 5 yen position on the vehicle.
5 is an antenna changeover switch that selects and controls the output of one of the plurality of antennas 1 to 4, and 6 receives a desired channel from the output corner of the antenna selected by the antenna changeover switch 5. 7 is a PIF signal processing circuit that amplifies the IF signal from Chicona 6 and detects the image, and 8 is a PIF signal processing circuit 7.
9 is a CR for displaying the three primary color signals.
It is T.

11 is a diversity control circuit that generates and controls (diversity operation) the antenna changeover switch 5. A synchronization separation circuit 10 separates a synchronization signal from the video detection output a and performs diversity control. The signal is supplied to the circuit 11 so that the diversity operation period is performed during the vertical retrace period.

12 is a system control circuit for controlling tuning of the tuner 6;
3 is a key input circuit for issuing commands to the system control circuit 12 by external input.

Further, 14 is an SIF circuit that extracts an audio IF signal of interchirelia frequency from the video detection output a, and 15 is an SIF circuit.
an audio amplifier for amplifying the audio signal from circuit 14;
16 is a speaker for amplifying the output from the audio amplifier 15;

The diversity receiving device performs a diversity operation every vertical retrace period. The diverge buoy control circuit 11 outputs a video detection output a in synchronization with the antenna switching signal.
Ripple hold the DC level of 1. Compare with IF4 Lebel. As a result of the comparison, the antenna that provides the best video detection output a is determined, and an antenna switching signal S for selecting the amplifier A is supplied to the antenna selection switch 5 to complete the diversity operation.

In this way, by comparing the levels of the video detection output a from multiple antennas during each vertical retrace period, the anti-noise signal can always provide the best reception output despite changes in reception conditions as the vehicle travels. By selecting , it is possible to reduce the deterioration of reception quality.

However, in the case of the above configuration, if the antennas are periodically switched for level comparison, there is a problem in that pulse noise is generated in the audio output when the level difference between the inputs of each amplifier is large. Since the noise generated in this J, U, etc. audio output includes a large amount of high frequency range, the above noise can be reduced by cutting the high frequency range of the audio output during the vertical retrace period in which the diversity operation is performed.

However, if the high range of the audio horn is cut, the audio band becomes narrower and the sound quality deteriorates. In particular, when receiving audio multiplex broadcasts, the sound quality deteriorates.

(Problems to be Solved by the Invention) As explained above, conventional in-vehicle diversity receivers cut the high frequency range of the audio output during the vertical retrace period during which diversity operation is performed, resulting in a noticeable deterioration in sound quality. There were drawbacks.

It is an object of the present invention to provide an in-vehicle diversity receiving device that eliminates the above-mentioned problems and alleviates the deterioration in audio quality caused by antenna switching.

[Structure of the Invention] (Means for Solving the Problems) The present invention includes a plurality of antennas, an antenna changeover switch for selectively controlling these antennas, and a channel for receiving signals from the antenna selected by the changeover switch. ”
- an intermediate frequency signal processing circuit that processes the intermediate frequency signal from the tuner; and a diversity system that supplies the antenna switching signal with an antenna switching signal that switches between the plurality of antennas based on the output of the intermediate frequency signal processing circuit. A control circuit generates a control signal for controlling whether or not to stop the diversity operation depending on the running mode, and supplies this control signal to the diverge buoy control circuit and audio circuit to stop the diversity operation while the vehicle is running. At the same time, the system is equipped with a system control circuit that cuts the high-pitched range of the audio output and, when stopped, basically stops the diversity operation and allows the high-pitched range of the audio output to pass through. ing.

(Function) In this invention, while the vehicle is running, the 8δ region of the audio output is cut off every time the diversity operation is performed to suppress the generation of noise, but when the vehicle stops, the diversity operation is stopped and the cause of the diversity noise is Eliminate. Therefore, there is no need to sharpen the treble range. Vehicles frequently stop, and by restoring the sound quality to normal frequency characteristics each time the accelerator stops, the voice quality can be improved. Furthermore, if diversity operation is required even when stopped, diversity can be performed by external operation or the like.

(Example) Hereinafter, the present invention will be explained in detail with reference to illustrated examples.

FIG. 1 is a block diagram showing an embodiment of a vehicle-mounted diversity receiver neck according to the present invention.

In FIG. 1, elements common to those in FIG. 5 are designated by the same reference numerals.

The plurality of antennas 1 to 4 are connected to an antenna switching switch 5. The antenna switching switch 5 selects antennas 1 to 1.
Selectively connect one of the four antennas to the tuner 6. The boolean 6 converts the received signal into an IF multiplied signal, and the PIF signal processing circuit 7 amplifies the IF multiplied signal and performs image detection.

The video detection output a is sent to the SIF circuit 1 that constitutes the audio circuit system.
4. Video signal processing circuit configuring the video circuit system 8. The signal is supplied to a synchronization separation circuit 10 and a diversity control circuit 11 which constitute a deflection circuit system.

The output of the video signal processing circuit 8 is supplied to the CRT 9,
The output of the IF circuit 14 is supplied to the speaker 1G via the variable band filter 20 and the audio amplifier 15, and the synchronization signal from the synchronization separation circuit 10 is supplied to the diversity control circuit 11.

Therefore, the system control circuit 12 has the key person horn circuit 1
Tuner 6 is tuned based on external input from 3
A tuning signal f is supplied to the tuner 6, and a control signal (ffiεC) is supplied to the diversity control circuit 11 to determine whether or not to stop the diversity operation. The system control circuit 12 also supplies the control signal C to the variable band filter 20 as a control signal for band variable.

In this way, the diversity control circuit 11 receives the control signal C1
An antenna switching signal S is formed based on the video detection output a and the synchronization signal.

Next, the generation of the control signal C by the system control circuit 12 will be explained in detail with reference to FIG.

In FIG. 2, elements common to those in FIG. 1 are designated by the same reference numerals. The system control circuit 12 supplies the AND circuit 19 with a signal e for determining whether or not to execute the diversity operation based on a command from the key input circuit 13. The running mode detector 17 supplies the AND circuit 19 with a detection signal d indicating whether the vehicle is running or stopped. The output of the AND circuit 19 as a result of this is the control signal "F"iC
The signal is applied to the diversity control circuit 12 as a signal.

Next, the operation of the vehicle-mounted diversity receiver will be explained. The process will be explained with reference to the flowchart shown in FIG.

FIG. 3 shows the control procedure of the system control circuit 12.

First, the signal e is at logic "1" when the vehicle is running. While the vehicle is running, the detection signal d from the running mode detector 17 is at logic "0". Therefore, the output of the AND circuit 19 during running becomes the logic II OII.

When the control signal C is logic 110'', step S1→S2
→The diversity loop of S1 is executed, and the diversity operation is performed every vertical retrace period. In the diversity operation, not only the antennas 1 to 4 are switched, but also the variable band filter 20 is controlled to cut the high frequency range.

When the vehicle stops, the detection number 19 d of the driving mode detector 17 becomes logic "1". At this time, if the signal C is also logic "1", the control signal C output from the AND gate 19 becomes logic "1". At the same time, the variable band filter 20 no longer cuts the range ≧b, and passes the audio signal in the normal band. For the above stop mode, "No" is determined in step 82, and '' is determined in the following step S3.
In other words, in the stop mode,
After the running stop is detected, the diversity operation is stopped in step S4 after a certain period of time has elapsed in step S4.

When the diversity operation stops, when the erotic cars are running, the diversity operation automatically returns to the diversity loop.

When J3 is at step $3 and there is a key input from the key input circuit 13 that says "Perform diversity", the signal C changes to logic "0" and the control signal C from the AND circuit 19
becomes logic II OII. As a result, a diversity loop is entered, the diversity control circuit 11 performs a diversity operation, and the variable band filter 20 cuts the high 8 band to 1. The diversity loop is canceled when the vehicle stops again.

In this way, in this embodiment, the diversity operation is stopped when the 11 cars are stopped and the generation of diversity noise is cut off, so the audio output can be output with the same characteristics as A, and high quality Q, ijl can be output. do. The quality of the voice is more noticeable when the vehicle is stopped than when the vehicle is running, and the diversity control in this embodiment is effective.

As another embodiment, as shown in FIG. 4, the system control circuit 12 includes a signal deterioration detection circuit 18 that determines the quality of the received signal based on the AGC voltage output from the PIF signal processing circuit 17, for example. By connecting, when the vehicle is stopped, the diversity operation may be automatically controlled instead of using the key manually.

[Effects of the Invention] As explained above, according to the present invention, since the Diverge I command is not performed in principle when the vehicle is stopped and there is little change in the reception environment, noise accompanying the diversity operation is not generated. There is an effect.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the Φ-field diversity receiving device according to the present invention, FIG. 2 is a block diagram explaining the embodiment of FIG. 1 in detail, and FIG. FIG. 4 is a block diagram showing another embodiment of the present invention, and FIG. 5 is a block diagram showing a conventional receiving apparatus. 1 to 4... Anno, 5... Ambient switch, 6... Tuner, 7... PIF signal processing circuit, 8
...Video signal processing circuit, 9...CRT, 10...
- Synchronous branch 1 circuit, 11... Diversity control circuit, 12... System control circuit, 13... Key input circuit, 14... SIF circuit, 15... Audio amplifier, 16... Speaker , 17... Running mode detector, 18... Signal deterioration detection circuit, 19... AND circuit, 20... Bandwidth variable filter, C... Control signal.

Claims (1)

[Claims] A plurality of antennas, an antenna changeover switch that selects and controls the plurality of antennas, a tuner that receives a signal from the antenna selected by the changeover switch, and an intermediate frequency signal from the tuner. an intermediate frequency signal processing circuit for processing; a diversity control circuit that supplies an antenna switching signal to the antenna changeover switch for switching the plurality of antennas based on the output of the intermediate frequency signal processing circuit; and a diversity control circuit that performs the diversity operation according to the driving mode. This control signal is supplied to the diversity control circuit and the audio circuit to perform diversity operation and cut the high frequency range of the audio output while driving, and to switch to stop mode. What is claimed is: 1. An in-vehicle diversity receiving device comprising: a system control circuit which, in principle, stops diversity operation and allows a high frequency range of audio output to pass through.