JPH0620265B2 - Automatic focus adjustment device - Google Patents
Automatic focus adjustment deviceInfo
- Publication number
- JPH0620265B2 JPH0620265B2 JP59161877A JP16187784A JPH0620265B2 JP H0620265 B2 JPH0620265 B2 JP H0620265B2 JP 59161877 A JP59161877 A JP 59161877A JP 16187784 A JP16187784 A JP 16187784A JP H0620265 B2 JPH0620265 B2 JP H0620265B2
- Authority
- JP
- Japan
- Prior art keywords
- circuit
- focus
- reference frequency
- lens
- adjustment device
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
- H04N23/60—Control of cameras or camera modules
- H04N23/67—Focus control based on electronic image sensor signals
- H04N23/673—Focus control based on electronic image sensor signals based on contrast or high frequency components of image signals, e.g. hill climbing method
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Automatic Focus Adjustment (AREA)
Description
【発明の詳細な説明】 産業上の利用分野 本発明は、テレビジョンカメラの撮像素子より得た信号
の高周波成分を検出し、その振巾が最大になる様にレン
ズの焦点整合装置を駆動する自動焦点整合装置に関する
ものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects a high frequency component of a signal obtained from an image pickup device of a television camera, and drives a lens focus matching device so as to maximize its amplitude. The present invention relates to an automatic focusing device.
従来例の構成とその問題点 従来技術としては、実公昭４０−２６５６８号のよう
に、撮像素子より得た信号をバンドパスフィルタを通す
ことにより高周波成分を検出し、この検出信号が最大に
なるように、レンズの焦点整合装置を駆動する方式があ
る。しかし、レンズの絞りが開放か、その附近であると
き、被写体までの距離と、レンズの焦点整合装置の位置
とがずれている場合、撮像素子の受光面では像がぼけて
いるので高周波成分はほとんど存在しない。そのため、
自動焦点整合装置は誤動作する。Configuration of Conventional Example and its Problems As a conventional technique, a high frequency component is detected by passing a signal obtained from an image pickup device through a bandpass filter as in Japanese Utility Model Publication No. 40-25668, and the detected signal becomes maximum. As described above, there is a method of driving the focus adjusting device of the lens. However, when the aperture of the lens is open or close to it, and if the distance to the subject and the position of the focus adjustment device of the lens are deviated, the image is blurred on the light receiving surface of the image sensor, so the high frequency component is It hardly exists. for that reason,
The automatic focusing device malfunctions.
その改良として特開昭５８−１８８９６６号公報では、
撮像素子より得た映像信号を帯域の異なる複数個のバン
ドパスフィルタに入力し、前記各バンドパスフィルタの
出力信号を演算処理し、演算処理した出力信号の振巾が
最高になるようにレンズの焦点整合装置を駆動するよう
にしている。すなわち、中心周波数が低いバンドパスフ
ィルタＢＰＦ1,中心周波数の高いＢＰＦ2とすれば、Ｂ
ＰＦ2の出力信号が小さいときＢＰＦ1の出力で自動焦点
の帰還ループを構成し、ＢＰＦ2の出力信号の振巾があ
る値以上になるとその出力で、自動焦点の帰還ループを
構成するようにしている。As an improvement, in JP-A-58-188966,
The video signal obtained from the image pickup device is input to a plurality of band pass filters having different bands, the output signals of the respective band pass filters are arithmetically processed, and the lens of the lens is adjusted so that the amplitude of the arithmetically processed output signal becomes maximum. The focus adjustment device is driven. That is, if the band pass filter BPF 1 having a low center frequency and the BPF 2 having a high center frequency are used, B
When the output signal of PF 2 is small, the output of BPF 1 forms an autofocus feedback loop, and when the amplitude of the output signal of BPF 2 exceeds a certain value, the output of the automatic focus feedback loop is formed. ing.
これにより実公昭４０−２６５６８号公報の場合の欠点
は解消するが、撮像素子から得られる被写体の高周波成
分はレンズの光学特性（レンズ収差等）の影響を受け、
必ずしも各バンドパスフィルタの最大点が目的とする被
写体の焦点位置に一致するとは限らず、誤動作の原因に
なってしまう。今、使用するバンドパスフィルタＢＰＦ
1〜ＢＰＦ3とした場合、その特性は第２図のようになる
が光学特性の影響を考慮した場合、第３図の実線で示す
ようになってしまうために、本来の最大点Ｐ0に対し、
Ｐ1の点もその隣接する部分から見た場合最大点として
感応し誤動作の原因になる。This eliminates the drawbacks of JP-B-40-26568, but the high-frequency component of the subject obtained from the image sensor is affected by the optical characteristics (lens aberration, etc.) of the lens,
The maximum point of each bandpass filter does not always coincide with the focal position of the target subject, which causes malfunction. Bandpass filter BPF used now
When 1 to BPF 3 , the characteristics are as shown in FIG. 2, but when the influence of the optical characteristics is taken into consideration, the characteristics become as shown by the solid line in FIG. 3, so the original maximum point P 0 is set. In contrast,
The point P 1 is also sensitive as the maximum point when viewed from the adjacent portion, which causes a malfunction.
発明の目的 本発明は、このような欠点を除去したもので、本来の最
大点で焦点がとれるようにしたものである。OBJECT OF THE INVENTION The present invention eliminates such drawbacks and makes it possible to focus at the original maximum point.
発明の構成 そのために、本発明ではバンドパスフィルタ出力にもと
づくスピードコントロール信号系と、方向指示系とを別
々とし、一方にＮＡＭ回路（フィルタのピーク検出回
路），他方に加算回路を設けたものである。Therefore, according to the present invention, the speed control signal system based on the output of the bandpass filter and the direction indicating system are separated, and the NAM circuit (filter peak detection circuit) is provided on one side and the addition circuit is provided on the other side. is there.
実施例の説明 以下、第１図の一実施例により説明する。Description of Embodiments An embodiment of FIG. 1 will be described below.
従来例の構成とその問題点 １はレンズ部でそれぞれａ，ｂ，ｃの複数板の単レンズ
で構成され、ａとｂはフォーカス部でモータ５で駆動さ
れる。ｃはマスターレンズ系のフォーカス部で、レンズ
駆動回路７で周期的に駆動される。２は被写体の光学情
報を電気信号に変換する撮像素子または撮像管（以下撮
像管デバイスという），３は撮像デバイス２の出力信号
を増巾する前置増巾回路，４はプロセス回路，６は基準
周波数発生回路，８はモータ駆動回路，９〜１１は第２
図のＢＰＦ1〜ＢＰＦ3のような特性を有するバンドパス
フィルタ，１２〜１４は基準周波数検出回路，１５〜１
７は増巾器，１８は加算回路，１９は同期検波回路，２
０は方向切換回路，２１はＮＡＭ回路，２２はスピード
コントロール回路である。Structure of Conventional Example and Problems Thereof 1 is composed of a single lens of a plurality of plates of a, b, and c in a lens part, and a and b are driven by a motor 5 in a focus part. Reference numeral c is a focus portion of the master lens system, which is periodically driven by the lens drive circuit 7. Reference numeral 2 is an image pickup element or a pickup tube (hereinafter referred to as a pickup tube device) that converts optical information of an object into an electric signal, 3 is a front widening circuit that widens an output signal of the image pickup device 2, 4 is a process circuit, and 6 is a process circuit. Reference frequency generation circuit, 8 is a motor drive circuit, 9 to 11 are second
Bandpass filters having characteristics such as BPF 1 to BPF 3 in the figure, 12 to 14 are reference frequency detection circuits, and 15 to 1
7 is an amplifier, 18 is an adding circuit, 19 is a synchronous detection circuit, 2
Reference numeral 0 is a direction switching circuit, 21 is a NAM circuit, and 22 is a speed control circuit.
この構成で加算回路１８，ＮＡＭ回路２１の代わりに演
算処理回路とすれば特開昭58−188966号公報の内容と同
じである。If an arithmetic processing circuit is used instead of the adder circuit 18 and the NAM circuit 21 in this configuration, it is the same as the contents of JP-A-58-188966.
これに対し、本発明では増巾器１５〜１７の出力を加算
回路１８とＮＡＭ回路２１に加えている。ここで、ＮＡ
Ｍ回路２１は各フィルタのピーク検出を行なうことにな
り、仮に各バンドパスフィルタ９〜１１の出力が第３図
の実線のようであっても、増巾器１５〜１７の出力をＮ
ＡＭ回路２１を通すことにより、第３図に示すＰ1，Ｐ2
のデップによる影響をなくすることができる。すなわ
ち、ＮＡＭ回路２１の出力は第４図に示す破線Ａとな
る。On the other hand, in the present invention, the outputs of the amplifiers 15 to 17 are added to the adder circuit 18 and the NAM circuit 21. Where NA
The M circuit 21 will detect the peaks of the respective filters, and even if the outputs of the bandpass filters 9 to 11 are as shown by the solid lines in FIG.
By passing through the AM circuit 21, P 1 , P 2 shown in FIG.
It is possible to eliminate the influence of the dep. That is, the output of the NAM circuit 21 becomes the broken line A shown in FIG.
そこで、焦点Ｄ0に対し、大きくボケている時より、Ｄ0
に近づくにあたってモータ５の駆動が低速で行なえるよ
うにスピードコントロール回路２２でもって、モータ駆
動回路８を制御すれば、レンズ１のフォーカスはスムー
ズに行なえる。この場合、焦点Ｄ0に対し現在のレンズ
のフォーカス方向は加算回路１８の出力により決められ
る。すなわち、加算回路１８は各フィルタ９〜１１の出
力（増巾器１５〜１７の出力((第４図のＢＰＦ1〜ＢＰ
Ｆ3))を加算することになり、その加算値はＢのように
なる。加算回路１８の出力は同期検波回路１９により同
期検波され、フォーカス方向の切換入力となり、切換回
路２０でもってモータ駆動回路８を制御し、モータ５の
回転方向（レンズ９のフォーカス方向）を決める。Therefore, with respect to the focus D 0 , D 0
When the motor drive circuit 8 is controlled by the speed control circuit 22 so that the motor 5 can be driven at a low speed when approaching, the lens 1 can be smoothly focused. In this case, the current focus direction of the lens with respect to the focus D 0 is determined by the output of the adder circuit 18. That is, the adder circuit 18 outputs the outputs of the filters 9 to 11 (the outputs of the amplifiers 15 to 17 ((BPF 1 to BP of FIG. 4).
F 3 )) will be added, and the added value will be B. The output of the adder circuit 18 is synchronously detected by the synchronous detection circuit 19 to serve as a focus direction switching input, and the switching circuit 20 controls the motor drive circuit 8 to determine the rotation direction of the motor 5 (the focus direction of the lens 9).
発明の効果 以上、実施例により説明したが、本発明によれば加算回
路，ＮＡＭ回路を設け、光学特性の影響を補正するよう
にしているために光学特性の影響を防止でき、より精度
の高い焦点整合が行なえる。Effects of the Invention As described above with reference to the embodiments, according to the present invention, since the addition circuit and the NAM circuit are provided to correct the influence of the optical characteristic, the influence of the optical characteristic can be prevented and the accuracy is higher. Focus can be adjusted.
第１図は本発明の一実施例における自動焦点整合装置の
ブロック図、第２図はバンドパスフィルタの特性図、第
３は光学特性を考慮した際のバンドパスフィルタの出力
波形図、第４図は一部の出力波形図である。 １８……加算回路、２１……ＮＡＭ回路。FIG. 1 is a block diagram of an automatic focusing device according to an embodiment of the present invention, FIG. 2 is a characteristic diagram of a bandpass filter, and FIG. 3 is an output waveform diagram of a bandpass filter in consideration of optical characteristics. The figure is a partial output waveform diagram. 18 ... Adder circuit, 21 ... NAM circuit.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 森下 忠之 神奈川県横浜市港北区樽町４丁目17番15号 セントラルエンジニアリング株式会社通 信機事業部内 (56)参考文献 特開 昭58−188966（ＪＰ，Ａ) 実開 昭53−95830（ＪＰ，Ｕ）) ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tadayuki Morishita 4-17-15, Tarumachi, Kohoku-ku, Yokohama-shi, Kanagawa Central Engineering Co., Ltd., Communication Business Division (56) Reference JP-A-58-188966 (JP , A) Actual development Sho 53-95830 (JP, U))
Claims (1)
それぞれ介した映像信号を加算する加算回路と、これら
の映像信号についてＮＡＭ回路によりピーク検出するピ
ーク検出回路と、基準周波数を発生する基準周波数発生
回路とを備え、上記加算回路の出力結果を上記基準周波
数によって同期検波し、フォーカス方向を制御するフォ
ーカスモータの方向指示制御として使用し、上記ピーク
検出回路の出力結果を上記フォーカスモータのスピード
制御に使用し、上記基準周波数をマスターレンズの駆動
として使用することを特徴とする自動焦点調整装置。1. An adder circuit for adding video signals respectively passing through a plurality of band pass filters having different bands, a peak detection circuit for detecting peaks of these video signals by a NAM circuit, and a reference frequency generation for generating a reference frequency. The output result of the adder circuit is synchronously detected by the reference frequency and is used as direction control control of the focus motor for controlling the focus direction, and the output result of the peak detection circuit is used for speed control of the focus motor. An automatic focusing device characterized by using the above-mentioned reference frequency for driving a master lens.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59161877A JPH0620265B2 (en) | 1984-08-01 | 1984-08-01 | Automatic focus adjustment device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59161877A JPH0620265B2 (en) | 1984-08-01 | 1984-08-01 | Automatic focus adjustment device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6141277A JPS6141277A (en) | 1986-02-27 |
| JPH0620265B2 true JPH0620265B2 (en) | 1994-03-16 |
Family
ID=15743675
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59161877A Expired - Fee Related JPH0620265B2 (en) | 1984-08-01 | 1984-08-01 | Automatic focus adjustment device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0620265B2 (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR940011885B1 (en) * | 1987-02-18 | 1994-12-27 | 상요덴기 가부시기가이샤 | Automatic focusing circuit for automatically matching focus in response to video signal |
| US4922346A (en) * | 1987-06-30 | 1990-05-01 | Sanyo Electric Co., Ltd. | Automatic focusing apparatus having a variable focusing speed and particularly suited for use with interlaced scanning |
| CA1313466C (en) * | 1988-05-11 | 1993-02-09 | Kenichi Kikuchi | Image sensing apparatus having automatic focusing function of automatically matching focus in response to video signal |
| JP2832029B2 (en) * | 1989-04-21 | 1998-12-02 | キヤノン株式会社 | Automatic focusing device |
| EP0512430B1 (en) * | 1991-05-02 | 1997-09-03 | Canon Kabushiki Kaisha | Automatic focusing device |
| JPH05292382A (en) * | 1992-04-15 | 1993-11-05 | Sony Corp | Auto-focus device |
| US6621521B1 (en) | 1996-07-26 | 2003-09-16 | Fuji Photo Film Co., Ltd. | Automatic focusing device for film scanner |
| JP3683653B2 (en) * | 1996-08-16 | 2005-08-17 | 富士写真フイルム株式会社 | Automatic focusing device for film scanner |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56132313A (en) * | 1980-03-19 | 1981-10-16 | Fuji Photo Film Co Ltd | Automatic focusing device |
| JPS58188966A (en) * | 1982-04-28 | 1983-11-04 | Matsushita Electric Ind Co Ltd | Automatic focus matching device |
-
1984
- 1984-08-01 JP JP59161877A patent/JPH0620265B2/en not_active Expired - Fee Related
Non-Patent Citations (1)
| Title |
|---|
| 実開昭５３−９５８３０（ＪＰ，Ｕ）） |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6141277A (en) | 1986-02-27 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |