JPH0815314B2 - Automatic focus adjustment device - Google Patents
Automatic focus adjustment deviceInfo
- Publication number
- JPH0815314B2 JPH0815314B2 JP61113946A JP11394686A JPH0815314B2 JP H0815314 B2 JPH0815314 B2 JP H0815314B2 JP 61113946 A JP61113946 A JP 61113946A JP 11394686 A JP11394686 A JP 11394686A JP H0815314 B2 JPH0815314 B2 JP H0815314B2
- Authority
- JP
- Japan
- Prior art keywords
- signal
- drive coil
- phase
- image pickup
- control signal
- 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 18
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 10
- 229910052742 iron Inorganic materials 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 125000006850 spacer group Chemical group 0.000 description 4
- 230000010355 oscillation Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000003534 oscillatory effect Effects 0.000 description 1
- 230000010363 phase shift Effects 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
- H04N23/95—Computational photography systems, e.g. light-field imaging systems
- H04N23/958—Computational photography systems, e.g. light-field imaging systems for extended depth of field imaging
- H04N23/959—Computational photography systems, e.g. light-field imaging systems for extended depth of field imaging by adjusting depth of field during image capture, e.g. maximising or setting range based on scene characteristics
Landscapes
- Engineering & Computer Science (AREA)
- Computing Systems (AREA)
- Theoretical 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、ビデオカメラの光学系等に利用できる自動
焦点調整装置に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic focus adjustment device that can be used in an optical system of a video camera.
従来の技術 近年、ビデオカメラ等において考案されている自動焦
点調整装置の原理を第３図，第４図に示す。2. Description of the Related Art The principle of an automatic focus adjusting device devised in a video camera or the like in recent years is shown in FIGS.
第３図において、２は振動プリズムであり、圧電素子
３の一端に接着等で取り付けられており、前記圧電素子
３の他端は前記振動プリズム２が撮像素子１の前面に位
置するように固定部に固定されている。この圧電素子３
を発振器４からの電気信号により振動させることによ
り、振動プリズム２は上下方向に振動する。その振動プ
リズム２の前方に固定プリズム５、レンズ系６が配置さ
れている。レンズ系６および固定プリズム５を通過した
光Ｃは振動プリズム２の振動により、集束位置がF1,F2,
F3のように微少量変化し、これに伴って撮像素子１の出
力電圧が変化する。In FIG. 3, reference numeral 2 denotes a vibration prism, which is attached to one end of the piezoelectric element 3 by adhesion or the like, and the other end of the piezoelectric element 3 is fixed so that the vibration prism 2 is located in front of the image pickup element 1. It is fixed to the section. This piezoelectric element 3
The oscillatory prism 2 is vibrated in the vertical direction by vibrating by the electric signal from the oscillator 4. A fixed prism 5 and a lens system 6 are arranged in front of the vibrating prism 2. The light C that has passed through the lens system 6 and the fixed prism 5 is focused at positions F 1 , F 2 ,
The output voltage of the image sensor 1 changes with a slight change such as F 3 .
撮像素子１で得られた出力信号をアンプ８により増幅
し、周波数検出器９により圧電素子３の振動周波数の信
号を検出する。その検出された信号の位相と発振器４の
発振出力との位置を位相比較器10により比較して焦点の
ずれ方向を検出し、撮像素子１の出力電圧がピークにな
るように駆動装置制御器11によりモーター等の駆動装置
12を制御してレンズ系６を構成している少なくとも１枚
のレンズ７を光軸方向に移動させることにより焦点を合
わせる。The output signal obtained by the image pickup device 1 is amplified by the amplifier 8, and the frequency detector 9 detects the signal of the vibration frequency of the piezoelectric device 3. The phase comparator 10 compares the position of the detected signal and the position of the oscillation output of the oscillator 4 to detect the direction of defocus, and the drive device controller 11 so that the output voltage of the image sensor 1 reaches a peak. Drive device such as motor
12 is controlled to move at least one lens 7 constituting the lens system 6 in the optical axis direction to focus.
次に、撮像素子１の出力電圧とモーター等の駆動装置
12の制御法について、第４図により説明する。撮像素子
１の出力電圧13がピークになる点Ｘが最適合焦点位置で
ある。振動プリズム２を振動させて集束位置を微少変化
させるときの発振器４の発振出力の波形を15とし、その
ときの撮像素子１の集力電圧13の波形を14とする。Next, the output voltage of the image sensor 1 and a driving device such as a motor
Twelve control methods will be described with reference to FIG. The point X where the output voltage 13 of the image pickup device 1 peaks is the optimum focus position. The waveform of the oscillation output of the oscillator 4 when the vibrating prism 2 is vibrated to slightly change the focusing position is set to 15, and the waveform of the collecting voltage 13 of the image pickup device 1 at that time is set to 14.
最適位置Ｘよりも左側のＡ点にレンズ系の焦点がある
場合には発振器には発振器４の発振波形15と撮像像１の
出力電圧波形14が同相になる。逆に右側のＢ点に焦点が
あるときは180゜位相がずれて逆相の関係になる。そこ
で位相が同相か逆相かを位相比較器10で検出することに
より焦点のずれ方向を検出することができる。モーター
等の駆動装置12の動作を制御して、レンズ系の最適合焦
位置Ｘに向かうようにレンズ７を移動させる。即ちＡ点
にあるときはロ方向に、Ｂ点にあるときはニ方向に出力
電圧が変化するようにレンズ７を移動させることによ
り、自動的に最適合焦状態に調整することができる。When the focal point of the lens system is at the point A on the left side of the optimum position X, the oscillation waveform 15 of the oscillator 4 and the output voltage waveform 14 of the captured image 1 are in phase with each other in the oscillator. On the contrary, when the focus is on point B on the right side, the phase shifts by 180 ° and the phase is reversed. Therefore, by detecting with the phase comparator 10 whether the phases are in-phase or anti-phase, the direction of defocus can be detected. The operation of the driving device 12 such as a motor is controlled to move the lens 7 toward the optimum focus position X of the lens system. That is, the optimum focus state can be automatically adjusted by moving the lens 7 so that the output voltage changes in the direction B at the point A and in the direction D at the point B.
発明が解決しようとする問題点 ところが、このような従来の方式においては２ケのプ
リズム2,5が必要となり、かつ第５図に示すように、光
学系の光軸（Ｚ軸方向）に対して２個のプリズム2,5の
直角面をx,y両軸に対して直角に取り付けることは困難
である。また最適合焦位置Ｘにレンズ７を移動させるた
めの駆動装置12も必要である。The problem to be solved by the invention is that in such a conventional system, two prisms 2 and 5 are required, and as shown in FIG. 5, with respect to the optical axis (Z-axis direction) of the optical system. It is difficult to attach the right-angled surfaces of the two prisms 2 and 5 at right angles to both the x and y axes. Further, a driving device 12 for moving the lens 7 to the optimum focus position X is also required.
本発明は上記のような従来例の問題点を除去し、組み
立て易く、安定した結像が得られる自動焦点調整装置を
提供することを目的とするものである。SUMMARY OF THE INVENTION It is an object of the present invention to provide an automatic focus adjustment device which eliminates the above-mentioned problems of the conventional example, is easy to assemble, and can obtain stable image formation.
問題点を解決するための手段 上記問題点を解決するために、本発明の自動焦点調整
装置は、レンズ系の光軸方向に沿って移動可能に固定部
に支持された撮像素子ホルダー上に固定され、前記レン
ズ系を通った光像を映像信号に変換する撮像素子と、前
記撮像素子ホルダーに設けられた駆動用コイルと、前記
駆動用コイルへの制御信号の印加に応じて、その駆動用
コイルに前記光軸方向への移動力を発生せしめるよう
に、前記駆動コイルに一定の磁界を印加する永久磁石
と、前記撮像素子を一定周期で光軸方向に微少量振動さ
せるために、発振器から前記駆動用コイルへ予め定めら
れた一定の周波数の第１の制御信号を前記制御信号の一
つとして印加する手段と、前記撮像素子の映像信号出力
より前記の定められた一定の周波数成分を検出する周波
数検出器と、その検出された信号の位相と前記第１の制
御信号との位相を比較し、その両者が同相か逆相かに応
じて前記撮像素子の合焦移動方向を示す信号を作成する
位相比較器と、その出力信号に応じて前記撮像素子をそ
の合焦移動方向に移動せしめれ直流バイアスを第２の制
御信号として前記制御信号の他の一つとして前記第１の
制御信号に重畳して、前記駆動コイルに印加する手段を
備えたものである。Means for Solving the Problems In order to solve the above problems, an automatic focus adjusting device of the present invention is fixed on an image sensor holder supported by a fixed portion so as to be movable along the optical axis direction of a lens system. And an image sensor for converting an optical image passing through the lens system into a video signal, a drive coil provided in the image sensor holder, and a drive coil for applying a control signal to the drive coil. A permanent magnet for applying a constant magnetic field to the drive coil so as to generate a moving force in the optical axis direction in the coil, and an oscillator for vibrating the image sensor in the optical axis direction in a small amount in a constant cycle. Means for applying a first control signal having a predetermined constant frequency to the drive coil as one of the control signals, and detecting the predetermined constant frequency component from the image signal output of the image sensor Do A frequency detector is compared with the phase of the detected signal and the phase of the first control signal, and a signal indicating the focusing movement direction of the image pickup element is created depending on whether the two are in phase or opposite phase. And a phase comparator for moving the image pickup element in the focusing movement direction according to the output signal of the phase comparator, and using the DC bias as the second control signal and the other of the control signals as the first control signal. It is provided with means for superimposing and applying to the drive coil.
作用 本発明は上記した構成の如く、第１の制御信号でフォ
ーカシング状態を検出し、その検出信号を第２の制御信
号として撮像素子を最適合焦点に位置せしめる構成よっ
て、レンズ系のレンズを移動させるための駆動装置を不
要とし、レンズ系の構造が簡単になり、またプリズムを
取り付ける必要もなくなり、装置が簡単になり組立も容
易になる。Action The present invention moves the lens of the lens system by the configuration in which the focusing state is detected by the first control signal and the detection signal is used as the second control signal to position the image sensor at the optimum focus point as in the above-described configuration. No driving device is required, the structure of the lens system is simplified, and it is not necessary to attach a prism, so that the device is simple and the assembly is easy.
実 施 例 以下本発明の一実施例の自動焦点調整装置について第
１図，第２図を用いて説明する。Example An automatic focus adjusting device according to an example of the present invention will be described below with reference to FIGS. 1 and 2.
第１図において、焦束位置微少振動用および焦点調整
用となる撮像素子はレンズ系６の光軸方向に矢印ホ，ヘ
のように微少量振動できるように駆動装置16上に保持さ
れている。また駆動装置16は微少量振動とは独立して、
光軸方向に前記撮像素子１をト及びチの方向に移動させ
て焦点調整することが可能となっている。その他の動作
原理、前記撮像素子１の出力電圧と制御については、前
述と同様なのでここでは省略する。微少振動手段及び駆
動装置16として電磁装置を用いた具体例について第２図
により説明する。撮像素子１は、押えリング17により円
筒状の撮像素子ホルダー18に固定されている。リング状
の振動板19,20の内円部は撮像素子ホルダー18の両端部
にそれぞれ固定リング21,22で固定され、外円部は第１
のスペーサー23、先端がＬ字状に折曲された第１の鉄板
ヨーク24、永久磁石25、先端がＬ字状に折曲された第２
の鉄板ヨーク26、第２のスペーサー27、押えリング28の
順に積層された形でビス29にて振動部ホルダー30に固定
され、レンズ鏡筒31に取り付けられている。駆動用コイ
ル32は、撮像素子ホルダー18の外側に巻き付けられてお
り、第１と第２の鉄板ヨーク24,26と永久磁石25により
形成される磁界ギャップ部に位置されている。駆動コイ
ル32に発振器４より周期的に変化する第１の信号電圧を
加えると、駆動用コイル32に生じる力により振動板19,2
0に支持されている撮像素子ホルダー18が光軸方向に微
少量振動する。この撮像素子ホルダー18の振動により撮
像素子１が光軸方向に矢印ホ，ヘのように微少量振動す
る。In FIG. 1, the image pickup element for slight vibration of the focus position and for focus adjustment is held on the driving device 16 so as to be able to vibrate in a slight amount in the optical axis direction of the lens system 6 as shown by arrows E and F. . In addition, the drive unit 16 is independent of the slight vibration,
It is possible to adjust the focus by moving the image pickup device 1 in the optical axis direction in the directions of T and C. The other operating principles, the output voltage of the image pickup device 1 and the control are the same as those described above, and are omitted here. A specific example in which an electromagnetic device is used as the microvibration means and the driving device 16 will be described with reference to FIG. The image pickup device 1 is fixed to a cylindrical image pickup device holder 18 by a pressing ring 17. The inner circles of the ring-shaped diaphragms 19 and 20 are fixed to the both ends of the image sensor holder 18 by fixing rings 21 and 22, respectively, and the outer circles are the first circle.
Spacer 23, a first iron plate yoke 24 whose tip is bent in an L shape, a permanent magnet 25, and a second whose tip is bent in an L shape
The iron plate yoke 26, the second spacer 27, and the pressing ring 28 are laminated in this order, fixed to the vibrating portion holder 30 with screws 29, and attached to the lens barrel 31. The drive coil 32 is wound around the outside of the image sensor holder 18, and is located in the magnetic field gap formed by the first and second iron plate yokes 24 and 26 and the permanent magnet 25. When a first signal voltage that changes periodically from the oscillator 4 is applied to the drive coil 32, the force generated in the drive coil 32 causes the vibration plates 19 and 2 to move.
The image sensor holder 18 supported by 0 vibrates slightly in the optical axis direction. The vibration of the image sensor holder 18 causes the image sensor 1 to vibrate in the optical axis direction by a small amount as indicated by arrows f and f.
一方、撮像素子１の振動による撮像素子１の出力信号
の位相の変化を従来と同様に位相比較器10で検出し、ピ
ーク値を検出することによって、最適合焦位置になるよ
うに駆動装置制御器11を介して駆動コイル32に直流バイ
アスなる第２の信号電圧を加え、撮像素子１をト及びチ
の方向に移動させる。On the other hand, as in the conventional case, the phase comparator 10 detects the change in the phase of the output signal of the image pickup device 1 due to the vibration of the image pickup device 1, and detects the peak value to control the drive device so that the optimum focus position is reached. A second signal voltage, which is a direct current bias, is applied to the drive coil 32 via the device 11 to move the image pickup device 1 in the directions T and C.
発明の効果 以上のように本発明によれば、撮像素子のレンズ系の
光軸方向振動を集束位置の微少量変化用に使用している
ので、従来のプリズムのような本来のレンズ系以外のも
のが不安となり、バックフォーカス量の小さなレンズ系
でも自動焦点調整が可能となる。EFFECTS OF THE INVENTION As described above, according to the present invention, since the vibration in the optical axis direction of the lens system of the image pickup device is used for changing the focusing position by a small amount, it is possible to use other than the original lens system such as the conventional prism. Things become uneasy, and automatic focus adjustment is possible even with a lens system with a small back focus amount.
さらに撮像素子移動を焦点調整用としても使用するた
め、レンズ系のレンズを移動させるための駆動装置が不
要となりレンズ系の構造が簡単になる組立が容易とな
る。Further, since the movement of the image pickup element is also used for focus adjustment, a drive device for moving the lens of the lens system is not required, and the assembly of the lens system having a simple structure is facilitated.
第１図は本発明の一実施例における自動焦点調整装置の
原理ブロツク図、第２図は同自動焦点調整装置の実施例
の要部を示す断面図、第３図は従来例における自動焦点
調整装置の原理ブロック図、第４図はその制御法を説明
する波形図、第５図は同従来例におけるプリズムの光軸
に対する配置図である。 １……撮像素子、４……発振器、６……レンズ系、16…
…駆動装置、17……押えリング、18……撮像素子、19,2
0……振動板、21,22……固定リング、23……第１のスペ
ーサー、24……第１の鉄板ヨーク、25……永久磁石、26
……第２の鉄板ヨーク、27……第２のスペーサー、28…
…押えリング、29……ビス、30……振動部ホルダー、31
……レンズ鏡筒、32……駆動用コイル。FIG. 1 is a block diagram showing the principle of an automatic focus adjusting device according to an embodiment of the present invention, FIG. 2 is a sectional view showing a main part of an embodiment of the automatic focus adjusting device, and FIG. FIG. 4 is a block diagram showing the principle of the device, FIG. 4 is a waveform diagram for explaining the control method, and FIG. 5 is a layout diagram of the prism in the conventional example with respect to the optical axis. 1 ... Image sensor, 4 ... Oscillator, 6 ... Lens system, 16 ...
… Drive device, 17 …… Pressing ring, 18 …… Image sensor, 19,2
0 …… Vibration plate, 21,22 …… Fixing ring, 23 …… First spacer, 24 …… First iron plate yoke, 25 …… Permanent magnet, 26
...... Second iron plate yoke, 27 ...... Second spacer, 28 ...
… Pressing ring, 29 …… Screw, 30 …… Vibration holder, 31
...... Lens barrel, 32 …… Drive coil.
Claims (1)
定部に支持された撮像素子ホルダー上に固定され、前記
レンズ系を通った光像を映像信号に変換する撮像素子
と、前記撮像素子ホルダーに設けられた駆動用コイル
と、前記駆動用コイルへの制御信号の印加に応じて、そ
の駆動用コイルに前記光軸方向への移動力を発生せしめ
るように、前記駆動コイルに一定の磁界を印加する永久
磁石と、前記撮像素子を一定周期で光軸方向に微少量振
動させるために、発振器から前記駆動用コイルへ予め定
められた一定の周波数の第１の制御信号を前記制御信号
の一つとして印加する手段と、前記撮像素子の映像信号
出力より前記の定められた一定の周波数成分を検出する
周波数検出器と、その検出された信号の位相と、前記第
１の制御信号との位相を比較し、その両者が同相か逆相
かに応じて前記撮像素子の合焦移動方向を示す信号を作
成する位相比較器と、その出力信号に応じて前記撮像素
子をその合焦移動方向に移動せしめる直流バイアスを第
２の制御信号として前記制御信号の他の一つとして前記
第１の制御信号に重畳して、前記駆動コイルに印加する
手段とよりなる自動焦点調整装置。1. An image pickup device fixed on an image pickup device holder supported by a fixed portion so as to be movable along the optical axis direction of the lens system, and converting an optical image passing through the lens system into a video signal. A drive coil provided on the image sensor holder, and a constant drive coil so that the drive coil generates a moving force in the optical axis direction in response to the application of a control signal to the drive coil. The permanent magnet for applying the magnetic field and a small amount of vibration of the image sensor in the optical axis direction at a constant period, the first control signal having a predetermined constant frequency from the oscillator to the driving coil is controlled. Means for applying as one of the signals, a frequency detector for detecting the predetermined constant frequency component from the image signal output of the image sensor, the phase of the detected signal, and the first control signal Phase with And a phase comparator that creates a signal indicating the focusing movement direction of the image pickup element depending on whether they are in phase or opposite phase, and moves the image pickup element in the focusing movement direction according to the output signal. An automatic focus adjusting device comprising means for applying a direct current bias as a second control signal to the first control signal as another one of the control signals and applying it to the drive coil.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61113946A JPH0815314B2 (en) | 1986-05-19 | 1986-05-19 | Automatic focus adjustment device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61113946A JPH0815314B2 (en) | 1986-05-19 | 1986-05-19 | Automatic focus adjustment device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62269576A JPS62269576A (en) | 1987-11-24 |
| JPH0815314B2 true JPH0815314B2 (en) | 1996-02-14 |
Family
ID=14625167
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61113946A Expired - Fee Related JPH0815314B2 (en) | 1986-05-19 | 1986-05-19 | Automatic focus adjustment device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0815314B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01269907A (en) * | 1988-04-20 | 1989-10-27 | Sanyo Electric Co Ltd | Video camera |
| CN1862358B (en) | 2005-05-11 | 2012-03-21 | 华移联科（沈阳）技术有限公司 | Automatic focusing device |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5813075A (en) * | 1981-07-16 | 1983-01-25 | Fuji Photo Film Co Ltd | Automatic focus adjuster for video camera |
-
1986
- 1986-05-19 JP JP61113946A patent/JPH0815314B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62269576A (en) | 1987-11-24 |
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