JP3310363B2 - Automatic switching device for antenna mounted on moving object - Google Patents
Automatic switching device for antenna mounted on moving objectInfo
- Publication number
- JP3310363B2 JP3310363B2 JP00209493A JP209493A JP3310363B2 JP 3310363 B2 JP3310363 B2 JP 3310363B2 JP 00209493 A JP00209493 A JP 00209493A JP 209493 A JP209493 A JP 209493A JP 3310363 B2 JP3310363 B2 JP 3310363B2
- Authority
- JP
- Japan
- Prior art keywords
- antenna
- switching
- signal
- switching device
- switching frequency
- Prior art date
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Description
【０００１】[0001]
【産業上の利用分野】本発明は、たとえば車両に搭載さ
れたテレビジョン受像機用の複数の受信アンテナを選択
的に切換使用するアンテナの自動切換装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic antenna switching device for selectively switching a plurality of receiving antennas for a television receiver mounted on a vehicle, for example.
【０００２】[0002]
【従来の技術】車載テレビジョン（ＴＶ）受像装置によ
りＴＶ放送電波を受信し視聴する場合、走行方向の変化
などに伴う電界変動による画面の乱れや同期はずれ等が
生ずるため、従来から、受信アンテナを複数搭載して選
択的に切換え、受信画像の不安定さを改善するようにし
た装置が知られている（たとえば特公昭６２−３２６５
４号公報）2. Description of the Related Art When a TV broadcast wave is received and viewed by an in-vehicle television (TV) image receiving apparatus, screen disturbance and loss of synchronization due to electric field fluctuations due to a change in running direction and the like occur. There is known an apparatus in which a plurality of devices are mounted and selectively switched to improve the instability of a received image (for example, Japanese Patent Publication No. Sho 62-3265).
No. 4)
【０００３】この車載テレビ用アンテナ切換装置は、図
８に示すように、４本の指向性アンテナからの受信信号
をアンテナ切換回路１で選択的に切換えて、チューナシ
ステム２に入力するものである。自動切換にあたって
は、切換えの影響が画面に現われないよう、例えばテレ
ビ映像信号の垂直帰線期間内で、各アンテナレベルのサ
ンプリング，比較，切換えを時分割で行なう。具体的に
は図８に示す如く、サンプル回路３はチューナシステム
２で検波した映像信号から水平同期区間を抜き出して各
アンテナに対応したレベルをサンプリングし、サンプリ
ングしたレベルをホールドする。最大値検出回路４で
は、それら出力のレベル比較を行ない、最大レベルのア
ンテナのものを検出し、比較結果をラッチする。タイミ
ング発生回路５は、水平同期期間はラッチされた最大レ
ベルのアンテナで受信するようにし、垂直帰線期間は４
つのアンテナを順次切換えて各アンテナから受信信号を
取込むように動作する。As shown in FIG. 8, this antenna switching device for a vehicle-mounted television selectively switches received signals from four directional antennas by an antenna switching circuit 1 and inputs the signals to a tuner system 2. . At the time of automatic switching, sampling, comparison, and switching of each antenna level are performed in a time-sharing manner, for example, during a vertical blanking period of a television video signal so that the effect of the switching does not appear on the screen. Specifically, as shown in FIG. 8, the sample circuit 3 extracts a horizontal synchronization section from the video signal detected by the tuner system 2, samples a level corresponding to each antenna, and holds the sampled level. The maximum value detection circuit 4 compares the levels of the outputs, detects the antenna having the maximum level, and latches the comparison result. The timing generation circuit 5 receives the signal through the latched maximum level antenna during the horizontal synchronizing period, and outputs the signal during the vertical blanking period by four.
The operation is such that the two antennas are sequentially switched to take in the received signal from each antenna.
【０００４】すなわちこのような従来装置は、上述のよ
うにテレビ映像信号の垂直帰線期間毎にレベルを比較
し、４本のアンテナのうち最大レベルが得られるアンテ
ナに切換え、そのアンテナ選択状態を次の垂直帰線期間
まで保持するようにして、走行中の複雑な電界変動に対
しても良好に追従でき、自動車の移動に対応して使用す
るアンテナの自動切換えが行なえる。That is, such a conventional apparatus compares the levels for each vertical blanking period of the television image signal as described above, switches to the antenna that can obtain the maximum level among the four antennas, and changes the antenna selection state. By maintaining the voltage until the next vertical flyback period, it is possible to satisfactorily follow a complicated electric field fluctuation during traveling, and to automatically switch the antenna to be used in accordance with the movement of the vehicle.
【０００５】[0005]
【発明が解決しようとする課題】しかしながら、このよ
うな従来のアンテナ切換装置にあっては、車両の走行状
況にかかわらず１／６０ｓｅｃごとに複数のアンテナの
受信レベルを比較して、そのうちの最大受信レベルのア
ンテナを選択して切換えるようにしており、車速に起因
する画質の乱れを考慮していないので、中，低速走行
時、および停車時に画面に横縞ノイズが入り、音声にス
イッチングノイズが入るという問題があった。すなわ
ち、図７に示すように本発明者による実験結果によれ
ば、１／６０ｓｅｃごとにアンテナ切換を行なって最大
受信感度のアンテナに順次に切換える従来装置では、８
０ｋｍ／ｈ以上の高速走行時は画像の横縞ノイズやスイ
ッチングノイズは発生しないが、４０ｋｍ／ｈ以上で８
０ｋｍ／ｈ未満の中速度域ではそれらのノイズがやや発
生し、４０ｋｍ／ｈ以下の低速走行時はそれらのノイズ
がさらに多くなり、停車時には非常に多くなることが判
明した。However, in such a conventional antenna switching device, the reception levels of a plurality of antennas are compared every 1/60 sec irrespective of the running condition of the vehicle, and the maximum reception level is determined. The reception level antenna is selected and switched, and the image quality disturbance due to the vehicle speed is not taken into consideration. Therefore, when the vehicle is running at middle speed, low speed, and when the vehicle is stopped, horizontal stripe noise appears on the screen and switching noise appears in the sound. There was a problem. That is, as shown in FIG. 7, according to the experimental results of the present inventor, according to the conventional apparatus that switches the antenna every 1/60 sec and sequentially switches to the antenna having the maximum reception sensitivity,
When running at a high speed of 0 km / h or more, no horizontal stripe noise or switching noise occurs in the image.
It was found that these noises were slightly generated in a medium speed range of less than 0 km / h, and that the noises were further increased when the vehicle was traveling at a low speed of 40 km / h or less, and extremely increased when the vehicle was stopped.
【０００６】このようなノイズ問題を解決する従来装置
としては、特公昭６２−３２６５４号公報に開示されて
いるアンテナ自動切換装置が知られている。この装置で
は、今回のアンテナ受信信号の最大受信信号レベルと前
回の最大受信信号レベルとの差が許容範囲内ならばアン
テナ切換を行なわないようにしている。ところが、発明
者らの実験によると、このような従来装置でも中、低速
走行時と停車時には横縞ノイズやスイッチングノイズが
発生することが判明した。As a conventional device for solving such a noise problem, there is known an automatic antenna switching device disclosed in Japanese Patent Publication No. 62-32654. In this device, if the difference between the maximum reception signal level of the current antenna reception signal and the previous maximum reception signal level is within an allowable range, the antenna switching is not performed. However, according to experiments by the inventors, it has been found that even in such a conventional device, horizontal stripe noise and switching noise are generated when the vehicle is running at low speed and when the vehicle is stopped.
【０００７】本発明の目的は、移動体の速度に応じてア
ンテナ切換頻度を制御することにより、移動体の移動状
況にかかわらず高品質の画像が得られるようにしたアン
テナ自動切換装置を提供することにある。[0007] An object of the present invention is to provide an automatic antenna switching device capable of obtaining a high-quality image irrespective of the moving state of a moving object by controlling the frequency of antenna switching according to the speed of the moving object. It is in.
【０００８】[0008]
【課題を解決するための手段】一実施例を示す図１に対
応付けて本発明を説明すると、本発明は、複数本のアン
テナでそれぞれ受信した信号を順次に取込み、それらの
信号の中で感度の良好なアンテナを選択する選択手段１
５，１６と、選択されたアンテナで受信するように受信
アンテナを切り換える切換手段１１とを具備する移動体
に搭載されたアンテナの自動切換装置に適用される。そ
して、上述した目的は、移動体の走行状態に応じてアン
テナ切換頻度を変更する切換頻度変更手段（１２，３
１，３２，３５）を具備し、切換頻度変更手段は移動体
が停止していることを判定する判定手段を有し、移動体
が停止していることが判定された直後に最も受信感度が
良好なアンテナを選択して走行を再開するまでそのアン
テナを保持することにより達成される。請求項２の切換
頻度変更手段は移動体の速度を検出する速度検出手段を
有し、検出された速度が早いほど切換頻度を大きくする
ものである。請求項３の切換頻度変更手段は速度が早い
ほど切換周期を短くするように構成されている。The present invention will be described with reference to FIG. 1 showing an embodiment. The present invention takes in signals received by a plurality of antennas sequentially, and among the signals, Selection means 1 for selecting an antenna with good sensitivity
The present invention is applied to an automatic antenna switching device mounted on a moving body, which includes switching means 11 for switching a receiving antenna so as to receive a signal with a selected antenna. The above-mentioned object is to provide a switching frequency changing means (12, 3) for changing the antenna switching frequency according to the traveling state of the moving body.
1, 32, 35), and the switching frequency changing means has a judging means for judging that the moving object is stopped, and the receiving sensitivity is maximized immediately after it is judged that the moving object is stopped.
Select a good antenna and restart it until you resume driving.
Achieved by holding the tena . The switching frequency changing means of the present invention has speed detecting means for detecting the speed of the moving body, and the switching frequency increases as the detected speed increases. The switching frequency changing means according to claim 3 is configured such that the higher the speed, the shorter the switching cycle.
【０００９】[0009]
【作用】移動体の走行状態に応じてアンテナ切換頻度を
変更する。とくに、移動体の速度を検出し、検出された
速度が早いほど切換頻度を大きくする。移動体が停止し
ていることを判定し、そのとき最も受信感度が良好なア
ンテナに切り換えて固定する。The antenna switching frequency is changed according to the traveling state of the moving body. In particular, the speed of the moving body is detected, and the higher the detected speed, the greater the switching frequency. It is determined that the moving object has stopped, and at that time, the antenna is switched to the antenna having the best reception sensitivity and fixed.
【００１０】なお、本発明の構成を説明する上記課題を
解決するための手段と作用の項では、本発明を分かり易
くするために実施例の図を用いたが、これにより本発明
が実施例に限定されるものではない。[0010] In the means and means for solving the above problems which explain the constitution of the present invention, the drawings of the embodiments are used to make the present invention easy to understand. However, the present invention is not limited to this.
【００１１】[0011]
【実施例】図１〜図７により本発明の一実施例を説明す
る。図１はアンテナ自動切換装置の一実施例を示すもの
で、１１はアンテナ切換回路であり、移動体に装着され
た４本のアンテナＡＴ１〜ＡＴ４で受信したＴＶ放送電
波のそれぞれをタイミング発生回路１２からのタイミン
グ信号に応じてある期間は時分割で取り出し、ある期間
は１本のアンテナの受信信号を取り出して後段の周知の
チューナシステム１３に送出する。チューナシステム３
は、高周波映像信号を検波復調してビデオ信号ＳVideo
を生成し、このビデオ信号は画像表示システム１４に送
られて画像として表示される。一方、ビデオ信号はサン
プル回路１５にも送られる。サンプル回路１５は、レベ
ル検出部と、レベルサンプリング部と、ピークホールド
部とを有し、各アンテナにおける受信信号のピーク値を
最大値検出回路１６に送出する。最大値検出回路１６
は、サンプル回路１５からの４つの信号の最大値を検出
してその信号をラッチし、最大受信信号に対応するアン
テナに切換える信号Ｓ９をタイミング回路１２に送出す
る。タイミング回路１２は、その切換信号Ｓ９と、後述
するアンテナ切換頻度制御手段を構成するフェイズロッ
クドループ回路３１，３２からの制御信号Ｓ５，Ｓ６と
により、車速に応じた周期で４本のアンテナから順次に
受信信号を取込むようにアンテナ切換回路１１を制御す
るとともに、切換信号Ｓ９に応じた最大受信感度を有す
るアンテナに切換え保持するようにアンテナ切換回路１
１を制御する。その詳細は後述する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows an embodiment of an automatic antenna switching device. Reference numeral 11 denotes an antenna switching circuit, which outputs a TV broadcast radio wave received by four antennas AT1 to AT4 mounted on a moving body to a timing generation circuit 12 respectively. In accordance with the timing signal from the antenna, a certain period is extracted in a time-division manner, and during a certain period, a reception signal of one antenna is extracted and sent to a well-known tuner system 13 at a subsequent stage. Tuner system 3
Detects and demodulates a high-frequency video signal to generate a video signal S Video
Which is sent to the image display system 14 and displayed as an image. On the other hand, the video signal is also sent to the sample circuit 15. The sample circuit 15 includes a level detection unit, a level sampling unit, and a peak hold unit, and sends the peak value of the received signal at each antenna to the maximum value detection circuit 16. Maximum value detection circuit 16
Detects the maximum value of the four signals from the sample circuit 15, latches the signals, and sends a signal S9 for switching to the antenna corresponding to the maximum received signal to the timing circuit 12. Based on the switching signal S9 and the control signals S5 and S6 from the phase locked loop circuits 31 and 32 constituting the antenna switching frequency control means described later, the timing circuit 12 sequentially starts from the four antennas at a cycle corresponding to the vehicle speed. The antenna switching circuit 11 controls the antenna switching circuit 11 so as to receive the received signal, and switches and holds the antenna having the maximum receiving sensitivity according to the switching signal S9.
Control 1 The details will be described later.
【００１２】３１は水平同期信号によって作動するフェ
イズロックドループ回路であり、位相比較器３１ａと、
カウンタ３１ｂと、電圧制御発振器（ＶＣＯ）３１ｃと
を有する。図５に示すような波形の水平同期信号とカウ
ンタ３１ｂの出力信号との位相差成分はコンデンサ３１
ｄで積分されて制御電圧として電圧制御発振器３１ｃの
制御電圧端子に入力される。したがって、ＶＣＯ３１ｃ
の発振周波数は水平同期信号ＳHとカウンタ３１ｂの出
力との位相差に応じて調節される。その結果、チューナ
１３から送出される図５に示す乱れた水平同期信号ＳH
を図５に示す安定した水平同期信号ＳH’に変換し、カ
ウンタ３１ｂのＱ0端子から図５に示す６３．５μｓｅ
ｃ周期の信号Ｓ６を得る。この信号Ｓ６はタイミング発
生回路１２に入力される。Reference numeral 31 denotes a phase locked loop circuit operated by a horizontal synchronizing signal, and includes a phase comparator 31a,
It has a counter 31b and a voltage controlled oscillator (VCO) 31c. The phase difference component between the horizontal synchronizing signal having the waveform shown in FIG.
The voltage is integrated by d and input to the control voltage terminal of the voltage controlled oscillator 31c as a control voltage. Therefore, VCO 31c
Oscillation frequency of which is adjusted in accordance with the phase difference between the output of the horizontal synchronizing signal S H and the counter 31b. As a result, the disturbed horizontal synchronizing signal S H shown in FIG.
Into a stable horizontal synchronizing signal S H ′ shown in FIG. 5, and 63.5 μs shown in FIG. 5 from the Q 0 terminal of the counter 31b.
A signal S6 having c periods is obtained. This signal S6 is input to the timing generation circuit 12.
【００１３】３２は垂直同期信号によって作動するフェ
イズロックドループ回路であり、位相比較器３２ａと、
分周器内蔵のカウンタ３２ｂと、電圧制御発振器３２ｃ
とを有する。カウンタ３２ｂはＶＣＯ３２ｃからの発振
パルスをカウントし、そのカウントパルスをＱ0端子に
出力するとともに、カウントしたパルス数を２，４，８
分周してＱ1〜Ｑ3端子にそれぞれ出力する。カウンタ３
２ｂの端子Ｑ0〜Ｑ3のいずれかは後述するアナログスイ
ッチ３５により選択される。図４に示すような波形の垂
直同期信号ＳVとカウンタ３２ｂの出力との位相差成分
はコンデンサ３２ｄで積分されて制御電圧として電圧制
御発振器（ＶＣＯ）３２ｃの制御電圧端子に入力され
る。したがって、ＶＣＯ３２ｃの発振周波数は垂直同期
信号ＳVとカウンタ３２ｂの出力との位相差に応じて調
節される。その結果、チューナ１３から送出される図４
に示す乱れた垂直同期信号ＳVを図４に示す安定した垂
直同期信号ＳV’に変換される。そして、カウンタ３２
ｂのＱ0〜Ｑ3端子のそれぞれから出力される車速に応じ
た周波数、すなわち（１／６０），（１／３０），（１
／１５），（１／７．５）ｓｅｃの信号Ｓ４を得る。こ
の信号Ｓ４のいずれか１つはデジタルスイッチ３５で選
択され、信号Ｓ５としてタイミング発生回路１２に入力
される。図４に示す信号Ｓ５は車速８０ｋｍ／ｈ以上の
ときに出力される１／６０ｓｅｃの信号である。Reference numeral 32 denotes a phase locked loop circuit operated by a vertical synchronization signal, and includes a phase comparator 32a,
A counter 32b with a built-in frequency divider and a voltage-controlled oscillator 32c
And Counter 32b counts the oscillation pulses from VCO32c, and outputs the count pulse to the Q 0 pin, counted the number of pulses 2,4,8
Respectively output to Q 1 to Q 3 terminal by dividing. Counter 3
Either 2b terminals Q 0 to Q 3 of is selected by the analog switch 35 to be described later. Phase difference component between the output of the vertical synchronizing signal S V and the counter 32b of the waveform shown in FIG. 4 is input to the control voltage terminal of the voltage controlled oscillator (VCO) 32c as a control voltage is integrated by the capacitor 32d. Accordingly, the oscillation frequency of VCO32c is adjusted according to the phase difference between the output of the vertical synchronizing signal S V and the counter 32b. As a result, FIG.
A vertical sync signal S V disordered shown is converted into a stable vertical sync signal S V 'shown in FIG. And the counter 32
b corresponding to the vehicle speed output from each of the Q 0 to Q 3 terminals, that is, (1/60), (1/30), (1
/ 15), a signal S4 of (1 / 7.5) sec is obtained. Any one of the signals S4 is selected by the digital switch 35, and is input to the timing generation circuit 12 as the signal S5. The signal S5 shown in FIG. 4 is a 1/60 sec signal output when the vehicle speed is 80 km / h or more.
【００１４】車速センサ３３は図２に示す車速に応じた
アナログ車速信号Ｓ１を出力し、Ａ／Ｄコンバータ３４
はこのアナログ信号を２ビットのデジタル車速信号Ｓ
２，Ｓ３に変換してアナログスイッチ３５に入力する。
このデジタル車速信号Ｓ２，Ｓ３によりアナログスイッ
チ３５の接点が切換えられ、垂直同期信号で作動するフ
ェイズロックドループ回路３２のカウンタ３２ｂの端子
Ｑ0〜Ｑ3から出力される信号Ｓ４のいずれかが位相比較
器３２ａに入力されるとともに、上述したように信号Ｓ
５としてタイミング発生回路１２に供給される。The vehicle speed sensor 33 outputs an analog vehicle speed signal S1 corresponding to the vehicle speed shown in FIG.
Converts this analog signal into a 2-bit digital vehicle speed signal S
2, and converted into S3 and input to the analog switch 35.
Are switched contact of the analog switch 35 by the digital speed signal S2, S3, either the phase comparison signal S4 output from the counter 32b terminal Q 0 to Q 3 in the phase-locked loop circuit 32 which operates a vertical synchronizing signal Input to the detector 32a and the signal S as described above.
5 is supplied to the timing generation circuit 12.
【００１５】タイミング発生回路１２は入力信号Ｓ５と
Ｓ６の論理積信号Ｓ７（図６参照）をアンテナ切換回路
１１に送出するとともに、その論理積信号Ｓ７の立上が
りで立ち下がり、信号Ｓ７の立ち下がりで立上がる信号
Ｓ８（図６参照）を生成してアンテナ切換回路１１に送
出する。信号Ｓ８の立ち上がっている期間、最大値検出
回路１６で検出された最大レベルのアンテナを選択する
信号Ｓ９がアンテナ切換回路１１に入力され、選択され
たアンテナからの受信信号がチューナ１３に送出され
る。The timing generation circuit 12 sends a logical product signal S7 (see FIG. 6) of the input signals S5 and S6 to the antenna switching circuit 11, and falls at the rising of the logical product signal S7 and at the falling of the signal S7. A rising signal S8 (see FIG. 6) is generated and sent to the antenna switching circuit 11. While the signal S8 is rising, a signal S9 for selecting the antenna of the maximum level detected by the maximum value detection circuit 16 is input to the antenna switching circuit 11, and a reception signal from the selected antenna is transmitted to the tuner 13. .
【００１６】図６（ａ）から分かるように、タイミング
発生回路１２は車速センサで検出された車速に応じて次
のタイミングで水平同期信号と同じ周波数の４つのパル
スからなるアンテナ切換信号Ｓ７を出力し、各アンテナ
を切換えて受信信号を順次に取込む。 車速８０ｋｍ／ｈ以上のときは１／６０ｓｅｃの周期 車速４０ｋｍ／ｈ以上で８０ｋｍ／ｈ未満のときは１
／３０ｓｅｃの周期 車速４０ｋｍ／ｈ以下のときは１／１５ｓｅｃの周期 停止時は停止直後に１度だけ切換信号Ｓ７を出力す
る。As can be seen from FIG. 6A, the timing generation circuit 12 outputs an antenna switching signal S7 consisting of four pulses having the same frequency as the horizontal synchronization signal at the next timing according to the vehicle speed detected by the vehicle speed sensor. Then, each antenna is switched to sequentially receive the received signal. 1/60 sec cycle when the vehicle speed is 80 km / h or more 1 when the vehicle speed is 40 km / h or more and less than 80 km / h
/ 30 sec cycle When the vehicle speed is 40 km / h or less, 1/15 sec cycle. When stopped, the switching signal S7 is output only once immediately after the stop.
【００１７】さらに、タイミング発生回路１２は、アン
テナ切換後に最大値検出回路１６から送出されているア
ンテナ選択信号Ｓ９によって受信感度の良好なアンテナ
を選択し、信号Ｓ８がハイレベルの間、すなわち、次の
アンテナ切換期間までそのアンテナからの受信信号をチ
ューナ１３に送る。Further, the timing generation circuit 12 selects an antenna having good reception sensitivity by the antenna selection signal S9 sent from the maximum value detection circuit 16 after the antenna switching, and while the signal S8 is at the high level, that is, the next time. Until the antenna switching period, a signal received from the antenna is sent to the tuner 13.
【００１８】このような構成のアンテナ自動切換装置で
は、図６に示すようにして最大受信感度のアンテナに切
換える頻度を車速に応じて制御する。すなわち、高速走
行時は垂直帰線期間（１／６０ｓｅｃ周期）ごとに最大
受信感度のアンテナを選択して次のアンテナ選択時期ま
でそのアンテナで受信し、中速走行時には１／３０ｓｅ
ｃごとに最大受信感度のアンテナを選択して次のアンテ
ナ選択時期までそのアンテナを保持し、低速走行時は１
／１５ｓｅｃごとに最大受信感度のアンテナを選択して
次のアンテナ選択時期までそのアンテナを保持し、停車
時は停止直後に１度だけ切換信号Ｓ７を出力して最大感
度のアンテナを選択して走行を再開するまでそのアンテ
ナを保持する。In the automatic antenna switching device having such a configuration, the frequency of switching to the antenna having the maximum reception sensitivity is controlled according to the vehicle speed as shown in FIG. That is, when traveling at high speed, the antenna with the highest reception sensitivity is selected every vertical retrace period (1/60 sec cycle) and received by that antenna until the next antenna selection time.
c, the antenna having the highest reception sensitivity is selected, and the antenna is held until the next antenna selection time.
Every 15 seconds, select the antenna with the highest receiving sensitivity and hold it until the next antenna selection time. When stopping, output the switching signal S7 only once immediately after stopping and select the antenna with the highest sensitivity to run Hold that antenna until restarting.
【００１９】このように車速に応じてアンテナ切換頻度
を変更するようにしたので、いずれの場合にも横縞ノイ
ズとスイッチングノイズの発生を抑制でき、良好な画像
や音声が得られる。なお、停車時のアンテナ切換方式と
しては、停車直前のアンテナをそのまま保持する方式
や、１／７．５ｓｅｃ周期で最大受信感度のアンテナを
決定して切換える方式を採用できる。Since the antenna switching frequency is changed in accordance with the vehicle speed in this manner, the occurrence of horizontal stripe noise and switching noise can be suppressed in any case, and good images and sounds can be obtained. As the antenna switching method at the time of stopping, a method of holding the antenna immediately before stopping as it is, or a method of determining and switching the antenna having the maximum reception sensitivity at a period of 1 / 7.5 sec can be adopted.
【００２０】以上では、車両に搭載したアンテナについ
て説明したが、本発明は車両に限らず船舶、航空機など
のあらゆる移動体に対して適用できる。また、テレビ受
信装置について説明したが、ラジオ受信装置、路車間情
報受信装置など無線による通信機器のアンテナ切換装置
として広く適用できる。Although the antenna mounted on the vehicle has been described above, the present invention is not limited to the vehicle but can be applied to any moving object such as a ship or an aircraft. Although the television receiver has been described, the present invention can be widely applied as an antenna switching device of a wireless communication device such as a radio receiver and a road-vehicle information receiver.
【００２１】以上の実施例の構成において、サンプル回
路１５と最大値検出回路１６が選択手段を、アンテナ切
換回路１１が切換手段を、車速センサ３３が速度検出手
段を、フェイズロックドループ回路３１，３２、デジタ
ルスイッチ３５およびタイミング発生回路１２などが切
換頻度変更手段をそれぞれ構成する。In the configuration of the above embodiment, the sampling circuit 15 and the maximum value detecting circuit 16 are the selecting means, the antenna switching circuit 11 is the switching means, the vehicle speed sensor 33 is the speed detecting means, and the phase locked loop circuits 31, 32. , The digital switch 35 and the timing generation circuit 12 constitute a switching frequency changing means.
【００２２】[0022]
【発明の効果】以上詳細に説明したように、本発明によ
れば、移動体の走行状態に応じてアンテナ切換頻度を変
更するようにしたので、ダイバーシティー機能を充分に
発揮したアンテナ自動切換装置が実現でき、横縞ノイズ
やスイッチングノイズが少ない良好な画像や音声が得ら
れる。とくに、移動体速度が速いほど切換頻度を大きく
するとともに停止時にはアンテナ切換を行なわいように
すれば、さらに移動体の走行状態にかかわりなく常に良
好な画像と音声が得られる。As described in detail above, according to the present invention, the antenna switching frequency is changed in accordance with the traveling state of the moving body, so that the automatic antenna switching device which sufficiently exhibits the diversity function is provided. And a good image or sound with little horizontal stripe noise and switching noise can be obtained. In particular, if the switching frequency is increased as the speed of the moving body is increased and the antenna is switched at the time of stopping, good images and sounds can always be obtained irrespective of the running state of the moving body.
【図１】本発明によるアンテナ自動切換装置の一実施例
を示すブロック図FIG. 1 is a block diagram showing an embodiment of an automatic antenna switching device according to the present invention.
【図２】アナログ車速信号とデジタル車速信号を示す波
形図FIG. 2 is a waveform diagram showing an analog vehicle speed signal and a digital vehicle speed signal.
【図３】車速とデジタル車速信号を説明する図FIG. 3 is a diagram illustrating a vehicle speed and a digital vehicle speed signal.
【図４】垂直同期信号で作動するフェイズロックドルー
プ回路の各部の波形とアンテナ切換信号を示す波形図FIG. 4 is a waveform chart showing waveforms of respective parts of a phase locked loop circuit operated by a vertical synchronization signal and an antenna switching signal.
【図５】水平同期信号で作動するフェイズロックドルー
プ回路の各部の波形図FIG. 5 is a waveform diagram of each part of a phase locked loop circuit operated by a horizontal synchronization signal.
【図６】アンテナ切換信号とアンテナ保持信号を示す波
形図FIG. 6 is a waveform diagram showing an antenna switching signal and an antenna holding signal.
【図７】車速とアンテナ切換周期を説明する図FIG. 7 is a diagram illustrating a vehicle speed and an antenna switching cycle.
【図８】従来のアンテナ切換装置の一例を示すブロック
図FIG. 8 is a block diagram showing an example of a conventional antenna switching device.
１１ アンテナ切換回路 １２ タイミング発生回路 １３ テレビチューナ １４ モニタ １５ サンプル回路 １６ 最大値検出回路 ３１ 水平同期信号で作動するフェイズロックドループ
回路 ３２ 垂直同期信号で作動するフェイズロックドループ
回路 ３３ 車速センサ ３５ アナログスイッチReference Signs List 11 antenna switching circuit 12 timing generation circuit 13 television tuner 14 monitor 15 sample circuit 16 maximum value detection circuit 31 phase locked loop circuit operated by horizontal synchronization signal 32 phase locked loop circuit operated by vertical synchronization signal 33 vehicle speed sensor 35 analog switch
Claims (3)
を順次に取込み、それらの信号の中で感度の良好なアン
テナを選択する選択手段と、 選択されたアンテナで受信するように受信アンテナを切
り換える切換手段とを具備するアンテナの自動切換装置
において、 前記移動体の走行状態に応じて前記アンテナ切換頻度を
変更する切換頻度変更手段を具備し、 前記切換頻度変更手段は前記移動体が停止していること
を判定する判定手段を有し、前記移動体が停止している
ことが判定された直後に最も受信感度が良好なアンテナ
を選択して走行を再開するまでそのアンテナを保持する
ことを特徴とする移動体に搭載されたアンテナの自動切
換装置。1. A signal receiving means for sequentially receiving signals respectively received by a plurality of antennas, selecting means for selecting an antenna having good sensitivity among the signals, and switching a receiving antenna so as to receive by the selected antenna. An automatic antenna switching device comprising: a switching unit; and a switching frequency changing unit configured to change the antenna switching frequency according to a traveling state of the moving body, wherein the switching frequency changing unit stops the moving body. a determination means for determining that there, best reception sensitivity is good antenna immediately after the movable body is judged to have stopped
An automatic switching device for an antenna mounted on a moving body, wherein the antenna is held until the vehicle resumes running .
変更手段は前記移動体の速度を検出する速度検出手段を
有し、検出された速度が早いほど前記切換頻度を大きく
することを特徴とする移動体に搭載されたアンテナの自
動切換装置。2. The apparatus according to claim 1, wherein said switching frequency changing means has speed detecting means for detecting a speed of said moving body, and said switching frequency increases as the detected speed increases. Automatic switching device for antennas mounted on moving vehicles.
変更手段は、検出された速度が早いほど切換周期を短く
するように構成されていることを特徴とする移動体に搭
載されたアンテナの自動切換装置。3. The antenna according to claim 2, wherein the switching frequency changing means is configured to shorten the switching period as the detected speed is higher. Automatic switching device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP00209493A JP3310363B2 (en) | 1993-01-08 | 1993-01-08 | Automatic switching device for antenna mounted on moving object |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP00209493A JP3310363B2 (en) | 1993-01-08 | 1993-01-08 | Automatic switching device for antenna mounted on moving object |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06204930A JPH06204930A (en) | 1994-07-22 |
| JP3310363B2 true JP3310363B2 (en) | 2002-08-05 |
Family
ID=11519768
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP00209493A Expired - Fee Related JP3310363B2 (en) | 1993-01-08 | 1993-01-08 | Automatic switching device for antenna mounted on moving object |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3310363B2 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7072628B2 (en) * | 2002-04-05 | 2006-07-04 | Qualcomm, Incorporated | Method and apparatus for determining receive diversity in mobile station |
| JP4592358B2 (en) * | 2004-08-31 | 2010-12-01 | 株式会社エヌ・ティ・ティ・ドコモ | Mobile communication system and mobile communication method |
| JP2007274039A (en) * | 2006-03-30 | 2007-10-18 | Clarion Co Ltd | Diversity device, and on-vehicle equipment |
| JP4992593B2 (en) * | 2007-07-26 | 2012-08-08 | 富士通モバイルコミュニケーションズ株式会社 | Mobile radio terminal device |
-
1993
- 1993-01-08 JP JP00209493A patent/JP3310363B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH06204930A (en) | 1994-07-22 |
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