JPH0588594B2 - - Google Patents
Info
- Publication number
- JPH0588594B2 JPH0588594B2 JP59188360A JP18836084A JPH0588594B2 JP H0588594 B2 JPH0588594 B2 JP H0588594B2 JP 59188360 A JP59188360 A JP 59188360A JP 18836084 A JP18836084 A JP 18836084A JP H0588594 B2 JPH0588594 B2 JP H0588594B2
- Authority
- JP
- Japan
- Prior art keywords
- sample
- signal
- hold
- fluorescent lamp
- optical path
- 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
- 230000003287 optical effect Effects 0.000 claims description 13
- 238000001514 detection method Methods 0.000 description 11
- 238000010586 diagram Methods 0.000 description 3
- 238000003384 imaging method Methods 0.000 description 3
- 238000005070 sampling Methods 0.000 description 2
- 230000001360 synchronised effect Effects 0.000 description 2
- 230000004397 blinking Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000007274 generation of a signal involved in cell-cell signaling Effects 0.000 description 1
- 230000007257 malfunction Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
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
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Focusing (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、カラーカメラ用の自動焦点装置に関
するものである。DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to an autofocus device for a color camera.
従来例の構成とその問題点
従来、映像信号の高周波成分を検出し、被写体
のボケによる信号のレベル差を針知し、フオーカ
ス調整を行なう自動焦点装置では、検出する高周
波成分が映像信号のボケだけでなく、光源の光量
変化に対しても信号レベル差が生じるので、けい
光灯下の撮影では光源フリツカのため誤動作が生
じるという欠点があつた。Conventional configuration and its problems Conventionally, automatic focusing devices detect high frequency components of video signals, detect signal level differences due to blurred objects, and perform focus adjustment. In addition, signal level differences also occur due to changes in the amount of light from the light source, so when photographing under fluorescent lights, there is a drawback that malfunctions occur due to light source flickering.
発明の目的
本発明では、上記欠点を除去するために映像信
号の高周波成分からけい光灯フリツカによる信号
変化をキヤンセルし、精度の高い自動焦点装置を
実現することを目的とする。OBJECTS OF THE INVENTION In order to eliminate the above-mentioned drawbacks, it is an object of the present invention to cancel signal changes due to fluorescent lamp flicker from the high frequency components of a video signal, and to realize a highly accurate autofocus device.
発明の構成
本発明は、上記目的を達成するために、ビデオ
カメラの垂直走査周期とけい光灯の点灯周期があ
る垂直期間で同期することを利用して、映像信号
の高周波成分をピーク・ホールドした信号をサン
プル・ホールドし、上記信号とある垂直期間後の
サンプル・ホールド信号を比較して、けい光灯フ
リツカによる信号レベルの変化を除去し、映像信
号のボケによる信号変化を取り出し、この信号に
より焦点調整するように構成したものである。Structure of the Invention In order to achieve the above object, the present invention peak-holds the high frequency components of a video signal by utilizing the fact that the vertical scanning period of a video camera and the lighting period of a fluorescent lamp are synchronized in a certain vertical period. Sample and hold the signal, compare the above signal with the sample and hold signal after a certain vertical period, remove changes in signal level due to fluorescent lamp flicker, extract signal changes due to blurring of the video signal, and use this signal to It is configured to adjust the focus.
実施例の説明
本発明の一実施例を図面に基づいて説明する。
第１図おいて、１はフオーカス・レンズ、２は光
路変調器、３は撮像デバイス、４はバンドパスフ
イルタ、５は検波回路、６はピーク・ホールド回
路、７，８，９，１０はサンプル・ホールド回
路、１１は差動増幅器、１２は光路変調器２を駆
動する駆動回路、１３は光路変調器２の駆動回路
１２の駆動周期で差動増幅器１１の信号出力を同
期検波し、フオーカス・レンズ１の回転方向とそ
のスピードを検出する回転方向・スピード検出回
路、１４はフオーカス・レンズ１の駆動装置、１
５は同期信号発生回路で、１６は４倍の垂直査周
期（15Hz）の出力端子、１７はリセツトパルス出
力端子１８，１９，２０，２１はサンプル・ホー
ルドパルス出力端子である。２２はけい光灯フリ
ツカ検出装置である。以下実施例の動作につい
て、第１図、第２図により説明する。DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described based on the drawings.
In Figure 1, 1 is a focus lens, 2 is an optical path modulator, 3 is an imaging device, 4 is a bandpass filter, 5 is a detection circuit, 6 is a peak hold circuit, 7, 8, 9, and 10 are samples.・Hold circuit, 11 is a differential amplifier, 12 is a drive circuit that drives the optical path modulator 2, 13 is a drive circuit that synchronizes the signal output of the differential amplifier 11 with the drive cycle of the drive circuit 12 of the optical path modulator 2, and performs focus detection. A rotation direction/speed detection circuit for detecting the rotation direction and speed of the lens 1; 14 is a drive device for the focus lens 1;
5 is a synchronizing signal generation circuit, 16 is an output terminal for four times the vertical scan period (15 Hz), 17 is a reset pulse output terminal, and 18, 19, 20, 21 are sample/hold pulse output terminals. 22 is a fluorescent lamp flicker detection device. The operation of the embodiment will be explained below with reference to FIGS. 1 and 2.
第２図は信号波形を示すものであり、ａは垂直
崇走査周期のパルス（以下Vpと略す）である。
ｂは光路変調器２の変調波であり、光路変調さた
光は撮像デバイス３にて映像信号に変換され、バ
ンドパスフイルタ４で高周波成分が検出される。
検波回路５にて信号を検波し、サンプル・ホール
ド回路６にて、第２図ｄのように変調波ｂに同期
した信号が得られる。ｃはリセツトパルスであ
る。上記信号をサンプル・ホールド回路７にてｅ
のタイミングホールドし、その出力ｇをさらにサ
ンプル・ホールド回路８にてｆのタイミングでホ
ールドし、ｈを得る。けい光灯フリツカ検出装置
２２よりフリツカ情報がない場合、サンプル・ホ
ールド回路９，１０はサンプル状態のままであ
り、ｇとｈの信号が差動増幅器１１に入力され、
差動増幅された信号はフオーカス・レンズ１の回
転方向・スピード検出回路１３に入る。第３図に
回転方向・スピード検出の方法を示す。光路変調
を行なうということは、Focus位置をズラすこと
に相当するため、合焦手前であるイの位置で
Near−Farと振動させた場合、出力信号は増加
する。また、合焦よりも遠い位置ロではNear−
Farの振動で信号レベルは減少する。合焦付近ハ
で振動させた場合、信号レベルの変化は小さくな
る。以上の動作から、光路変調路２の振動と差動
増幅器１１の出力信号の変化方向を比較すれば、
フオーカス・レンズ１の回転方向が判別され、信
号レベルで合焦スピードが決定する。そこで、回
転方向・スペード検出回路１３の情報により、駆
動装置１４によつてフオーカス・レンズ１を駆動
しフオーカスを合わせる。しかし、けい光灯フリ
ツカがある場合、第２図ｄの信号は光路変調だけ
でなく、フリツカ情報も同時に重畳されてしま
う。 FIG. 2 shows a signal waveform, where a is a pulse (hereinafter abbreviated as V p ) of the vertical scanning period.
b is a modulated wave of the optical path modulator 2; the optical path modulated light is converted into a video signal by the imaging device 3, and a high frequency component is detected by the bandpass filter 4.
A detection circuit 5 detects the signal, and a sample/hold circuit 6 obtains a signal synchronized with the modulated wave b as shown in FIG. 2d. c is a reset pulse. The above signal is sent to the sample/hold circuit 7.
The output g is further held at the timing f in the sample/hold circuit 8 to obtain h. When there is no flicker information from the fluorescent lamp flicker detection device 22, the sample and hold circuits 9 and 10 remain in the sampling state, and the g and h signals are input to the differential amplifier 11.
The differentially amplified signal enters the rotation direction/speed detection circuit 13 of the focus lens 1. Figure 3 shows the method of detecting the rotational direction and speed. Performing optical path modulation is equivalent to shifting the focus position, so the
When vibrating near-far, the output signal increases. Also, at a position further away than the focus, Near-
The signal level decreases due to Far vibration. When vibrating near focus, the change in signal level becomes small. From the above operation, if we compare the vibration of the optical path modulation path 2 and the direction of change of the output signal of the differential amplifier 11, we get:
The rotational direction of the focus lens 1 is determined, and the focusing speed is determined based on the signal level. Therefore, the focus lens 1 is driven by the drive device 14 to adjust the focus based on the information from the rotation direction/spade detection circuit 13. However, if there is fluorescent lamp flicker, the signal shown in FIG. 2(d) will contain not only optical path modulation but also flicker information.
第２図のけい光灯点滅周期ｉと垂直周期ｊを比
較すると、６倍の垂直走査期間に１度VP1とVP7
で輝度レベルが同一となる。そこで、けい光灯フ
リツカ検出装置２２よりけい光灯フリツカ情報が
あつた場合、サンプル・ホールド回路７はサンプ
ル・ホールドされた信号ｈをサンプル・ホールド
回路８，９，１０にて、ｆ，ｋ，ｌのタイミング
で順次サンプル・ホールドし、信号ｈを６倍の垂
直走査期間遅延させた信号ｎと比較すれば、フリ
ツカによる影響を除去することができる。 Comparing the fluorescent lamp blinking period i and the vertical period j in Fig. 2, it is found that V P1 and V P7 once every 6 times the vertical scanning period.
The brightness level is the same. Therefore, when fluorescent lamp flicker information is received from the fluorescent lamp flicker detection device 22, the sample-and-hold circuit 7 sends the sample-and-held signal h to the sample-and-hold circuits 8, 9, and 10. The influence of flicker can be removed by sequentially sampling and holding signal h at timing l and comparing signal h with signal n delayed by six times the vertical scanning period.
発明の効果
本発明は、上記のような構成であり、けい光灯
フリツカによる光路変調信号の変化を除去し、精
度の高い自動焦点装置を実現することができる。Effects of the Invention The present invention has the above-described configuration, and can eliminate changes in the optical path modulation signal due to fluorescent lamp flicker, thereby realizing a highly accurate autofocus device.
第１図は本発明の一実施例における自動焦点装
置のブロツク図、第２図は第１図における各部の
信号波形を示す波形図、第３図は本発明の一部で
ある第１図におけるフオーカス・レンズの回転方
向・スピード検出を示す原理図である。
１…フオーカス・レンズ、２…光路変調器、３
…撮像デバイス、６…ピーク・ホールド回路、
７，８，９，１０…サンプル・ホールド回路、１
１…差動増幅器、２２…けい光灯フリツカ検出装
置。
FIG. 1 is a block diagram of an automatic focusing device according to an embodiment of the present invention, FIG. 2 is a waveform diagram showing signal waveforms of each part in FIG. 1, and FIG. FIG. 3 is a principle diagram illustrating rotation direction and speed detection of a focus lens. 1... Focus lens, 2... Optical path modulator, 3
...imaging device, 6...peak hold circuit,
7, 8, 9, 10...sample/hold circuit, 1
1... Differential amplifier, 22... Fluorescent lamp flicker detection device.
Claims (1)
調された光を映像信号に変調する装置と、変換さ
れた映像信号の高周波成分を検出するバンドパス
フイルタと、検出された信号を波波し、ピーク・
ホールドする装置と、ピーク・ホールドされた入
力信号を２倍の垂直走査周期で順次ホールドする
直列に配置された複数のサンプル・ホールド装置
と、第１および最大６倍の垂直走査期間遅延され
る最終のサンプル・ホールド信号を比較する差動
増幅装置と、その差動出力と光路変調信号より＝
フオーカス・レンズの駆動方向及び速度を検出す
る装置と、けい光灯フリツカ情報を検出する装置
およびけい光灯フリツカ情報がない時は、上記サ
ンプル・ホールド装置中、第１と最終のものを除
いてサンプル状態にし、２倍の垂直走査同期の差
を比較するようにし、けい光灯フリツカ情報があ
るときにはすべてサンプル・ホールド状態し、６
倍の垂直走査同期の差を比較するように制御する
装置を設けた自動焦点装置。1 A device that modulates the optical path at a predetermined period, a device that modulates the optical path modulated light into a video signal, a bandpass filter that detects high frequency components of the converted video signal, and a device that converts the detected signal into waves. ,peak·
a plurality of sample and hold devices arranged in series that sequentially hold the peak-held input signal for twice the vertical scan period; A differential amplifier that compares the sample and hold signals of , and its differential output and optical path modulation signal =
A device for detecting the driving direction and speed of the focus lens, a device for detecting fluorescent lamp flicker information, and when there is no fluorescent lamp flicker information, all of the above sample and hold devices except the first and last ones are used. Set it to the sample state, compare the difference in double vertical scanning synchronization, and set it to the sample/hold state when there is fluorescent lamp flicker information.
An autofocus device provided with a control device to compare the difference in vertical scan synchronization times.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59188360A JPS6165671A (en) | 1984-09-07 | 1984-09-07 | Automatic focusing device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59188360A JPS6165671A (en) | 1984-09-07 | 1984-09-07 | Automatic focusing device |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5078175A Division JPH0678207A (en) | 1993-04-05 | 1993-04-05 | Fluorescent lamp flicker detector |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6165671A JPS6165671A (en) | 1986-04-04 |
| JPH0588594B2 true JPH0588594B2 (en) | 1993-12-22 |
Family
ID=16222257
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59188360A Granted JPS6165671A (en) | 1984-09-07 | 1984-09-07 | Automatic focusing device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6165671A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2580576B2 (en) * | 1986-12-03 | 1997-02-12 | キヤノン株式会社 | Focus detection device |
| JPS6411479A (en) * | 1987-07-03 | 1989-01-17 | Tamron Kk | Automatic focal point adjusting device for video camera |
| JP2516486B2 (en) * | 1991-02-28 | 1996-07-24 | 株式会社エルモ社 | Projector |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5772115A (en) * | 1980-10-23 | 1982-05-06 | Canon Inc | Output stablizing circuit for focus detector |
-
1984
- 1984-09-07 JP JP59188360A patent/JPS6165671A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5772115A (en) * | 1980-10-23 | 1982-05-06 | Canon Inc | Output stablizing circuit for focus detector |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6165671A (en) | 1986-04-04 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |