JP3868264B2 - Distance measuring device with blur detection function - Google Patents

Description

但し、ｎ：シフト量、Ｗ：ウインド内データ数、ｉ：ウインド内データＮｏ．
ｋ：演算エリア先頭センサデータＮｏ．
図１８は、各シフト値毎の相関値を示す相関データグラフである。
【０１５６】
一対のウインド１２０ａ、１２０ｂのデータの一致度が最も高くなるのは、図１８に示すように、ウインド１２０ｂを１センサ分ずつシフトさせて求めたＦ（ｎ）が極小値（Ｆ（ｎ）＝Ｆｍｉｎ）となる場合で、シフト量ｎ＝ｎＦｍｉｎが被写体像の相対的な像ずれ量となる。
【０１５７】
この像ずれ量を、手ブレ判定時には、Ｘ方向の手ブレ量Ｘ（ｎ）として用い、測距時にはＡＦデータとして被写体距離データの算出に用いる。
【０１５８】
以上説明したように、本実施の形態によれば、とりわけ手ブレが気になる撮影シーンにおいて、ホールディングチェックモードを設定すれば、手ブレ時には警告を発し、撮影者に手ブレを認識させるようにしたので、手ブレによる失敗のない写真撮影が可能となる。
【０１５９】
しかも、本実施の形態によれば、ホールディング判定時には、従来の測距用のセンサとして使用されているセンサを手ブレ判定にも有効使用し、像信号を記憶するメモリ領域も測距時とホールディングチェック時とで兼用するようにしているので、コストアップとなることなく、信頼性の高い手ブレ判定を行うことができる。
【０１６０】
【発明の効果】
従って、以上説明したように、本発明によれば、測距センサを利用して手ブレ検出を行う場合に、メモリ容量の増大を招くことなく、従来より高精度かつ簡単な構成で実現し得るブレ検出機能付き測距装置を提供することができる。
【図面の簡単な説明】
【図１】図１の（ａ）は、本発明の実施の形態に係るカメラの外観と、その一部を切り欠いた内部構造を示す斜視図であり、図１の（ｂ）は、本実施の形態に用いられる硬質プリント基板１４と、フレキシブルプリント基板（以下フレキ基板と称する）７との配置関係を示す側面図であり、図１の（ｃ）は、本発明の測距光学系を説明するために示す図である。
【図２】図２の（ａ）は、本発明の実施の形態に係るカメラの電子回路を含む制御系の構成を示すブロック図であり、図２の（ｂ）は、図２の（ａ）のモノリシック加速度計３によって検出可能な方向を説明するための図である。
【図３】図３は、図２の加速度ＩＣ３の製造工程の一例を示す図である。
【図４】図４は、図３の製造工程によって製造される加速度ＩＣ３の各部の構成を示す図である。
【図５】図５の（ａ）は、処理回路２９の構成例を示すブロック図であり、図５の（ｂ）は、処理回路２９からのの出力波形を示す図である。
【図６】図６は、本発明の実施の形態に係るカメラの振動検出の原理について説明するための図である。
【図７】図７の（ａ）、（ｂ）は、本発明の特徴たるＡＦセンサの出力（像信号）と、加速度センサの出力との違いについて説明するために示した図である。
【図８】図８は、本発明の実施の形態に係るカメラのホールディングチェック機能を撮影モードの一つにしておき、ユーザーが必要と判断する場合のみに設定できるようにする場合を示す図である。
【図９】図９は、図８の（ｂ）、（ｃ）の表示セグメント６ｂ、６ｃの配置例を示す図である。
【図１０】図１０は、本発明の第１の実施の形態に係るカメラ１０を背面から見た外観図である。
【図１１】図１１は、本発明の第１の実施の形態に係るカメラ１０を前面から見た外観図である。
【図１２】図１２は、本発明の実施の形態で採用している二つの検出方式によるセンサを搭載したホールディングチェックモード付カメラ内のＣＰＵが、内蔵のプログラムに沿ったシーケンスにより行う表示制御等を説明するために示すフローチャートである。
【図１３】図１３は、図２の（ａ）のファインダ内ＬＣＤ６ａに表示される警告パターンの一例を示す図である。
【図１４】図１４は、図２の（ａ）のファインダ内ＬＣＤ６ａに表示される通常表示パターンの一例を示す図である。
【図１５】図１５は、図２の（ａ）のファインダ内ＬＣＤ６ａに表示される手ブレ警告の表示［パターン１］の例を示す図である。
【図１６】図１６は、本発明の実施の形態においてＡＦセンサ５ｃａ、５ｃｂにより光電変換された像信号が、記憶手段１１０の基準部像信号格納領域１１０ａ、参照部像信号格納領域または最新像信号格納領域１１０ｂにそれぞれ記憶される形態を説明するために示す図である。
【図１７】図１７は、本発明における相関演算のウインドシフト方法を説明するための図である。
【図１８】図１８は、図１７の相関演算のウインドシフト方法における各シフト値毎の相関値を示す相関データグラフである。
【符号の説明】
１４…硬質プリント基板、
７…フレキシブルプリント基板（フレキ基板）、
３…モノリシック加速度計（加速度ＩＣ）、
１０…カメラ、
９…撮影レンズ、
８…ストロボ、
１５…ファインダ対物レンズ、
１…ワンチップマイクロコンピュータ（ＣＰＵ）、
２…インターフェースＩＣ（ＩＦＩＣ）、
４…メモリ（ＥＥＰＲＯＭ）、
１２…コネクタ、
６…表示素子（ＬＣＤ）、
５…オートフォーカス（ＡＦ）用センサ、
１３…通信ラインやスイッチ用パターン、
１１…警告表示部、
１０１…被写体、
１０２…像信号、
５ｄ…受光レンズ、
５ｃ…センサアレイ、
２０…シリコン基板（ＩＣチップ）、
２１…酸化膜、
２２…ポリシリコン層、
２２ｃ…可動電極、
２４、２５…別の電極、
２３ａ、２３ｂ…可動電極２２ｃの腕部、
２９…処理回路、
３２…搬送波発生器（発振回路）、
３１…Ｙ方向加速度センサ、
３４…復調回路、
３６…フィルタ回路、
３７…ＰＷＭ信号発生回路、
５ａ…オートフォーカス（ＡＦ）部、
５ｂ…測光部、
６ａ…ファインダ内ＬＣＤ６ａ、
８ａ…メインコンデンサ、
１１ａ…抵抗１１ａ、
スイッチ…１３ａ、１３ｂ、
１９…シャッタ、
１８…モータ、
１６…回転羽根、
１７…フォトインタラプタ、
６ｂ、６ｃ…表示セグメント、
６１…ファインダ接眼部、
６５…セルフタイマー表示用ＬＥＤ、
１０ａ…バリア。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a distance measuring apparatus with a blur detection function using an AF sensor that detects a vibration state such as a camera shake that occurs during shooting by a camera, and in particular, warns a photographer to prevent camera shake. The present invention relates to a shake detection device that can be effectively used.
[0002]
[Prior art]
In general, when taking a picture with a camera in hand, there may be a so-called camera shake in which the camera shakes during exposure and becomes a failed photograph when the shutter speed is slow.
[0003]
In order to prevent this camera shake, various anti-vibration techniques have been studied.
[0004]
This anti-vibration technique can be divided into two techniques: vibration detection and countermeasures against the detected vibration.
[0005]
Further, the vibration countermeasure technology is further classified into a warning technology for allowing the user to recognize the vibration state, and a technology for preventing image degradation due to camera shake by driving and controlling the photographing lens.
[0006]
Among them, as a warning technique, the present applicant has proposed a camera that is resistant to camera shake by devising display means, for example, in Japanese Patent Application No. 11-201845.
[0007]
Further, an example in which a distance measuring sensor is applied is recently disclosed in Japanese Patent Laid-Open No. 2001-165622, and more anciently, in Japanese Patent Publication No. 62-27686.
[0008]
[Problems to be solved by the invention]
However, among general users, there are people who do not know what camera shake is in the first place and do not recognize the necessity of camera shake prevention and push the release button deeply to take a failed photo.
[0009]
In particular, in order to have you take a picture of yourself while traveling, if you hand over the camera to a person nearby and ask for a release operation, the requested person will be too confused, as shown in FIG. 6 (a). There are many cases in which the picture is ruined because of a large amount of movement.
[0010]
In addition, when camera shake detection is performed using a distance measuring sensor, if a storage means for image signals output from the distance measuring sensor is provided for camera shake detection, a huge storage capacity is required, and a large capacity memory is required. There have been problems such as an increase in cost due to use and a problem in storing data used for other than camera shake detection.
[0011]
[Problems to be solved by the invention]
The present invention has been made in view of the above-described circumstances. When camera shake detection is performed using a distance measuring sensor, the present invention is realized with a higher accuracy and simpler configuration than before without increasing the memory capacity. An object of the present invention is to provide a distance measuring device with a blur detection function.
[0012]
[Means for Solving the Problems]
According to the present invention, in order to solve the above problems,
(1) a pair of light receiving lenses for forming a subject image;
A pair of line sensors that photoelectrically convert a subject image formed by the pair of light-receiving lenses and output as an image signal;
Storage means for storing image signals output from the pair of line sensors,
Output from the pair of line sensors A pair of Based on image signal Perform ranging operation The pair of line sensors Either one of From Every predetermined time Change in output image signal On the basis of Camera shake detection Action In a distance measuring device with a blur detection function capable of performing
The storage area of the storage means is divided into two, and a pair of image signals output from the pair of line sensors are stored in the divided storage area during the distance measuring operation, and the pair of image signals are stored during the camera shake detection operation. An image signal serving as a reference of an image signal output from one of the line sensors and the latest image signal are stored in the storage area divided into two. A distance measuring device with a blur detection function is provided.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0017]
In the present embodiment, a liquid crystal display means for displaying a photographing range (finder field of view) according to a photographing mode provided in a finder of a camera with a change in light transmittance, and as a camera shake determination, in addition to the distance measuring sensor described above, In combination with a monolithic accelerometer, it is equipped with a vibration detection means that detects camera vibration and suggests the occurrence of camera shake. When camera shake occurs, the transmittance of the display area of the liquid crystal display means is patterned. This is a technology that makes it easy for users to recognize the occurrence of camera shake.
[0018]
The monolithic accelerometer is formed on an IC chip, and is a device that detects vibration using a capacitance change generated between a movable pattern and a non-movable pattern. For example, those proposed in Japanese Patent Application Laid-Open No. 8-178854 can be used.
[0019]
As a configuration of this monolithic accelerometer, both patterns described above are formed of a polysilicon member on a silicon substrate, one electrode is movable and responds to acceleration, and the other electrode is stationary with respect to the acceleration. In this state, a pair of capacitors is formed.
[0020]
When acceleration is applied to such a silicon substrate, the capacity of one capacitor increases and the capacity of the other capacitor decreases.
[0021]
A signal processing circuit for converting these differential capacitances into voltage signals is required, and these movable electrodes, capacitors and signal processing circuits are monolithically formed on the same substrate.
[0022]
Japanese Patent Application Laid-Open No. 8-178954 describes an application for operating a safety device such as an automobile braking system or an air bag. By making it monolithic, dimensions, cost, required power, and reliability are described. The point which is excellent in etc. is explained.
[0023]
In the present embodiment, such a monolithic accelerometer element is effectively arranged and controlled, and while maintaining the above characteristics, a camera-specific situation is taken into account, and a highly accurate and effective anti-vibration camera is realized.
[0024]
Note that this portion may be constituted by a shock sensor or the like for detecting an impact or the like instead of the monolithic accelerometer element.
[0025]
1 and 2 are diagrams illustrating a configuration example of a camera according to the present embodiment.
[0026]
FIG. 1A is a perspective view showing the appearance of the camera according to the present embodiment and the internal structure with a part thereof cut away.
[0027]
FIG. 1B is a side view showing a positional relationship between the hard printed board 14 used in the present embodiment and a flexible printed board (hereinafter referred to as a flexible board) 7.
[0028]
(C) of FIG. 1 is a figure shown in order to demonstrate the ranging optical system of this invention.
[0029]
FIG. 2A is a block diagram showing a configuration of a control system including the electronic circuit of the camera according to the present embodiment.
[0030]
FIG. 2B is a diagram for explaining directions that can be detected by the monolithic accelerometer 3 of FIG.
[0031]
As shown in FIG. 1A, on the front surface of the camera 10, a finder objective lens 15 and a light receiving lens of a distance measuring unit for autofocus are arranged in addition to the photographing lens 9 and the strobe 8.
[0032]
An electronic circuit for moving the camera 10 fully automatically is provided inside the camera 10.
[0033]
This electronic circuit also includes the above-described monolithic accelerometer (acceleration IC) 3 mounted on the hard printed circuit board 14, and in order to show the positional relationship, a part of the internal structure is shown in FIG. Notched to show.
[0034]
In addition to the acceleration IC 3, on the rigid printed circuit board 14, a one-chip microcomputer (CPU) 1 for controlling an operation related to photographing of the entire camera and an actuator such as a motor are operated to provide a mechanical system unit. An interface IC (IFIC) 2 to be driven is mounted.
[0035]
Further, in the vicinity of the CPU 1, for example, an EEPROM is provided as a memory 4 for storing adjustment data for component variation in the camera assembly process.
[0036]
FIG. 1B is a diagram showing the relationship between the hard printed circuit board 14 and the flexible circuit board 7 in a state where the main part of the camera 10 of FIG. 1 is removed and viewed from the lateral direction.
[0037]
Since the rigid printed board 14 is not bent along the curved surface inside the camera 10, the flexible board 7 is used, and these two boards are connected by the connector 12.
[0038]
On the flexible substrate 7, as shown in FIG. 1A, a display element (LCD) 6 is mounted, and a communication line with the autofocus (AF) sensor 5 and a switch pattern 13 are formed. ing.
[0039]
The flexible substrate 7 wraps around to the back of the camera 10 and is mounted with a notification element such as a sound emitting element PCV or LED in the warning display unit 11 as shown in FIG. In addition to the transmitted signal, the AF sensor 5 is also provided with a signal.
[0040]
As shown in FIG. 1C, the AF sensor 5 obtains the distance to the subject 101 using the principle of triangulation, and the image signal 102 of the subject 101 is converted into two light receiving lenses 5d and 5d. The subject distance can be detected from the relative position difference X detected by the sensor array 5c.
[0041]
Since the subject generally has a vertical shadow, the two light receiving lenses 5d are arranged in the horizontal direction (X direction) as shown in FIG. 1A, and the sensor array 5c is also divided in the horizontal direction. ing.
[0042]
As a result, an image shift in the X direction that occurs when there is camera shake in the lateral direction can be detected by the AF sensor 5.
[0043]
Accordingly, as shown in FIG. 2B, the acceleration IC 3 is arranged in a direction in which blur in the Y direction is detected rather than in the X direction, and the detection in both the X and Y directions is supplemented by separate sensors. .
[0044]
Here, the acceleration IC3 will be described.
[0045]
FIG. 3 is a diagram illustrating an example of a manufacturing process of the acceleration IC 3.
[0046]
First, as shown in FIGS. 3A and 3B, an oxide film 21 is formed on a silicon substrate (IC chip) 20, and a pattern using a resist mask is formed on the oxide film 21.
[0047]
Next, as shown in FIG. 3C, when the exposed portion is removed by etching and a resist mask is formed, an opening can be formed in an arbitrary portion.
[0048]
Thereafter, a polysilicon layer 22 is deposited as shown in FIG.
[0049]
Thereafter, as shown in FIG. 3E, the oxide film 21 is selectively removed by wet etching, whereby the polysilicon layer 22 is formed on the silicon substrate 20 in a bridge-like structure.
[0050]
The polysilicon layer 22 is made conductive by diffusing impurities such as phosphorus.
[0051]
FIG. 4 is a diagram showing the configuration of each part of the acceleration IC 3 manufactured as described above.
[0052]
First, the movable electrode 22c having support portions at four corners as shown in FIG. 4B is formed on the silicon substrate 20 by the bridge structure as described above.
[0053]
Further, as shown in FIG. 4A, another electrodes 24 and 25 are formed on the silicon substrate 20 and arranged adjacent to the arm portions 23a and 23b of the movable electrode 22c described above. A very small capacitor is formed between the arm 23 a and the electrode 24, and between the arm 23 b and the electrode 25.
[0054]
Furthermore, as shown in FIG. 4C, an IC with a processing circuit capable of detecting acceleration in a predetermined direction is monolithic by using an IC chip in which the movable electrode structure is arranged on the silicon substrate 20. Composed.
[0055]
That is, as shown in FIG. 4C, the processing circuit 29 is formed on the IC chip together with the above-described monolithic movable electrode capacitor.
[0056]
This detects a capacitance component that changes by the movable electrode 22c, and outputs a signal corresponding to the acceleration.
[0057]
Due to the movement of the bridge-shaped movable electrode 22c, one of the capacitances formed in the two electrodes increases and the other decreases, so that the acceleration in the arrow direction shown in FIG. 4B can be detected.
[0058]
Therefore, when this IC chip is mounted on a camera, acceleration in the Y direction can be detected as shown in FIG.
[0059]
FIG. 5A is a block diagram illustrating a configuration example of the processing circuit 29.
[0060]
As described above, capacitance components are formed between the arm portions 23a and 23b and the electrodes 24 and 25 included in the Y-direction acceleration sensor 31 for detecting movement in the Y direction, and the arm portions 23a and 23b These capacities change with movement.
[0061]
This change in capacitance is converted into an electrical signal by the processing circuit 29.
[0062]
The processing circuit 29 includes a carrier wave generator (oscillation circuit) 32 that oscillates a carrier wave having a pulse waveform, and a demodulation circuit 34 that demodulates each oscillation waveform changed by the capacitance change of the Y-direction acceleration sensor 31 by full-wave switching rectification. The filter circuit 36 outputs an acceleration-dependent analog signal, and the PWM signal generation circuit 37 performs analog PWM conversion.
[0063]
FIG. 5B is a diagram showing an output waveform from the processing circuit 29.
[0064]
Thus, the duty ratio of the pulse (the ratio between the half cycle T1 and the full cycle T2 of the output waveform shown in FIG. 5B) changes according to the acceleration.
[0065]
Therefore, the acceleration IC 3 outputs a voltage signal proportional to the acceleration or a pulse width modulation (PWM) signal proportional to the acceleration.
[0066]
The CPU 1 that can handle only digital signals can detect acceleration by demodulating the PWM signal using a built-in counter.
[0067]
For the voltage signal proportional to the acceleration, an adjuster having an A / D converter may be used.
[0068]
If a PWM signal is used, it is not necessary to mount an A / D converter on the CPU 1.
[0069]
FIG. 2A is a block diagram showing a configuration of a control system including an electronic circuit of a camera on which such an acceleration IC 3 is mounted.
[0070]
In this configuration, a CPU 1 that controls the entire camera, an IFIC 2, a monolithic accelerometer (acceleration IC) 3, a memory (EEPROM) 4 that stores adjustment data, an autofocus (AF) unit 5a, and photometry Unit 5b, a liquid crystal display element (LCD) 6 for displaying information related to camera settings and photographing, an in-finder LCD 6a provided in the finder for displaying information relating to photographing, and light emission for emitting auxiliary light and the like A strobe unit 8 including a tube, a main capacitor 8a for charging a light for emitting light from the arc tube, a photographing lens 9 having a zooming function, a warning display unit 11 including an LED, and a warning display unit 11 are connected in series. Resistor 11a, switches 13a and 13b for starting a camera photographing sequence, and photographing lens 9 A motor 18 for driving a shutter 19 and a driving mechanism such as film feeding, a rotating blade 16 that rotates in conjunction with the motor 18, and a hole in the rotating blade 16 that rotates for driving control of the motor 18 are optically detected. And the photo interrupter 17.
[0071]
The motor 18 may switch the driving destination by a switching mechanism when driving each driving mechanism such as the photographing lens 9 and the shutter 19, or each driving mechanism may be provided with another motor.
[0072]
In this configuration, the CPU 1 governs the shooting sequence of the camera according to the operation state of the switches 13a and 13b.
[0073]
That is, in addition to the warning display by the in-finder LCD 6a for camera shake warning according to the output of the monolithic accelerometer 3, the AF unit 5a including the AF distance measuring unit at the time of shooting, and the photometric unit for measuring the luminance of the subject for exposure control 5b is driven, a necessary signal is received, and the motor 18 is controlled via the IFIC 2 described above.
[0074]
At this time, the rotation of the motor 18 is transmitted to the rotary blade 16, and the IFIC 2 shapes the signal output from the photointerrupter 17 according to the position of the presence or absence of the adjustment hole.
[0075]
Then, the CPU 1 monitors the rotation state of the motor 18 based on the output signal from the IFIC 2.
[0076]
Further, auxiliary light is emitted by the flash unit 8 as necessary.
[0077]
FIG. 13 shows an example of a warning pattern displayed on the finder LCD 6a.
[0078]
The in-finder LCD 6a is used for screen display in the panorama mode, blackout display indicating that the shutter has been released, and the like.
[0079]
The patterns A and C shown in FIG. 13 use a light shielding pattern displayed at the time of panoramic shooting setting. First, as shown in screen A, only the upper area is shielded, and then as shown in screen B. In this pattern, only the central area indicating the photographing range at the time of panoramic photographing is shielded, and finally only the lower area of the panoramic light shielding area is shielded as shown in screen C.
[0080]
By repeating this display mode, a user looking through the viewfinder can recognize that camera shake has occurred.
[0081]
Incidentally, the blackout display can be performed by simultaneously shielding the A, B, and C patterns.
[0082]
FIG. 14 shows an example of a normal display pattern displayed on the finder LCD 6a.
[0083]
With such a display, it is possible to express a feeling that the viewfinder screen is shaken. Therefore, when the user resets the camera and no camera shake occurs, the screen shown in FIG. D or the screen E shown in FIG. 14B is returned to, and the subject can be monitored.
[0084]
FIG. 15 shows an example of a camera shake warning display pattern displayed on the LCD 6a.
[0085]
The camera shake warning display pattern shown in FIG. 15 uses a light-shielding portion that is displayed when panoramic shooting is set, similarly to the pattern described in FIG.
[0086]
That is, the camera shake warning display pattern shown in FIG. 15 is a pattern in which the upper and lower light shielding portions are alternately displayed as the screen A and the screen C.
[0087]
The camera shake warning display pattern shown in FIG. 15 is different from the pattern shown in FIG. 13 because the center of the screen is always visible, so that the expression of the subject does not become difficult to see in the panoramic shooting mode.
[0088]
Further, since the blinking is performed as described above at the time of camera shake warning, the user does not misunderstand unlike the normal display in FIGS. 14 (a) and 14 (b).
[0089]
Next, the principle of camera vibration detection with such a configuration will be described with reference to FIG.
[0090]
As shown in FIG. 6 (a), when the user 10 holds the camera with one hand, there is a tendency to slightly vibrate the camera in an oblique direction, as shown in FIG. 6 (b). It can be decomposed into a movement in the direction and the Y direction.
[0091]
In general, a general user is often unconscious about such a micro vibration causing an effect of “blur” at the time of photographing, and the camera 10 detects the micro vibration and performs display as described in FIG. Thus, since the user takes a picture such as putting the left hand 100a on the camera and taking measures such as suppressing vibrations, it is possible to take a picture without failure due to camera shake.
[0092]
However, since it is always annoying when a warning is issued, high-class users who are well aware of the occurrence of camera shake may rather enjoy taking pictures using blur effectively. The function is set to one of the shooting modes, and the device can be set only when the user deems it necessary.
[0093]
That is, as shown in FIG. 8A, the switch 13c and the liquid crystal display unit 6 are provided, and only the functions of the film counter 6a and the like are operated in the normal state. The camera shake mode is set only when the operation is performed as shown in b).
[0094]
When this mode is set, the display segments 6b and 6c are displayed as shown in FIGS. 8B and 8C. When the portion 6b flashes, the user has entered the holding check mode. I understand.
[0095]
As shown in FIG. 8D, since this mode display also serves as a part of the self-timer mode display, there is no burden on the layout in the LCD.
[0096]
In this case, the display segments 6b and 6c are arranged on the substrate 6d as shown in FIG. 9, so that display control can be performed independently.
[0097]
FIG. 10 is an external view of the camera 10 as viewed from the back.
[0098]
If the user holds the camera in this mode and the holding check is unstable, the LCD in the finder blinks as described above, and the finder eyepiece 61 of the camera 10 as shown in FIG. You may make it warn by blinking the warning display part 11 by LED nearby.
[0099]
FIG. 11 is an external view of the camera 10 as viewed from the front.
[0100]
As shown in FIG. 11, the self-timer display LED 65 may be blinked so that the holding of the photographer can be checked when the camera owner asks another person to take a picture.
[0101]
FIGS. 7A and 7B are views for explaining the difference between the output (image signal) of the AF sensor and the output of the acceleration sensor, which is a feature of the present invention.
[0102]
However, in this case, it is assumed that the user has shakes with movements in both the X and Y directions as shown in FIGS. 6A and 6B.
[0103]
As shown in FIG. 7A, at the instant when the camera moves from the stationary state at the image position X1 and time t = t0, the acceleration sensor outputs a signal when the camera starts moving at the timing of t = t1, If the camera moves at a constant speed between the image positions X2 to X6 and the time t = t2 to t = t6, the acceleration sensor does not output a signal because there is no acceleration even though the camera is shaken.
[0104]
Then, when the camera stops again, at the timing of t = t7, an output is generated from the acceleration sensor in a direction that stops the previous constant speed motion, and the camera is stopped after time t = t8. It becomes a state.
[0105]
In order to compensate for this acceleration sensor, the image sensor (AF sensor) of the camera outputs an image signal that continues to change even during constant speed movement. Therefore, if this output is determined, even if the output of the acceleration sensor is 0, the CPU 1 of the camera Can determine that the camera is moving.
[0106]
Further, as shown in FIG. 7B, an output may be generated from the acceleration sensor even if the image signal hardly changes.
[0107]
This is the case where the user is trying to fix and hold the camera while shaking, and unlike FIG. 7A, the change in the image is small. There are many cases where you can take pictures without any problems.
[0108]
In other words, even if a large output is generated from the acceleration sensor, the camera may only move slightly, and even if the acceleration sensor responds only occasionally, the camera position may change greatly.
[0109]
In addition, there are some limitations in blur determination by the AF sensor.
[0110]
For example, in a scene where there is no contrast or a scene where the image is dark and the image is not known, the image sensor (AF sensor) of the camera cannot make a determination because the change in the image is not understood.
[0111]
Also, as in this embodiment, a sensor with only one direction of detection does not understand camera movement or image change in a different direction, and if the camera shakes too much, the AF sensor monitors it. As a result, the image is completely changed and the blur amount cannot be accurately determined.
[0112]
Therefore, it is necessary to devise a method for determining blur by appropriately using sensors based on the two detection methods of the acceleration sensor and the AF sensor.
[0113]
FIG. 12 is a flowchart for explaining display control and the like performed by a CPU in a camera with a holding check mode equipped with a sensor based on these two detection methods in a sequence according to a built-in program.
[0114]
For example, in the camera shown in FIG. 11, when the barrier 10a that protects the front lens is opened, the user first performs framing, has not yet entered the holding operation, and the camera is moved greatly. Judgment by is not valid.
[0115]
Since the AF sensor only monitors a narrow portion in the screen, it cannot be quantitatively evaluated for a large camera movement.
[0116]
Therefore, in step S1, first, the output of the acceleration sensor is determined, and even if there is a shock when the barrier is opened or a shock when the user holds the camera, the display of the holding warning is prohibited for a predetermined time ( Step S2).
[0117]
Thereafter, image detection using the AF sensor is started (step S3).
[0118]
As a result, it is determined whether the image detection is suitable for the holding check. Therefore, in the case of low luminance (step S4) or low contrast (step S5), this is determined and acceleration detection is performed without using the image signal. Is entered into the blur determination flow (step S10).
[0119]
When the acceleration sensor outputs a signal, when no acceleration is detected for a predetermined time (step S11, S12), a warning is issued (step S13).
[0120]
As shown in FIG. 7A, this determines that the camera continues to move at a constant speed and informs the user that camera shake can occur.
[0121]
In this state, there is a possibility that the user intends to take a panning shot. Therefore, for example, the LCD in the finder does not blink (FIG. 13 etc.) and the LED 11 near the finder eyepiece blinks as shown in FIG. The warning may be different from the case where the AF sensor is also used together (step S26).
[0122]
If the image signal has high brightness and high contrast and is suitable for camera shake determination, image detection is repeated at predetermined time intervals (step S22) in steps S20 and S21 (steps S23 and S24).
[0123]
FIG. 16 shows that the image signals photoelectrically converted by the AF sensors 5ca and 5cb in the embodiment of the present invention are the reference part image signal storage area 110a, the reference part image signal storage area (during distance measurement) of the storage means 110, or the latest. It is a figure shown in order to demonstrate the form each memorize | stored in the image signal storage area (at the time of camera shake detection) 110b.
[0124]
In this image detection, as shown in FIG. 16B, one sensor 5ca of the pair of AF sensors 5c, the reference part image signal storage area 110a of the storage means 110, the latest image signal storage area (when camera shake is detected). ) 110b.
[0125]
First, in step S21, the image signal photoelectrically converted by the AF sensor 5ca is stored in the latest image signal storage area 110b of the storage unit 110.
[0126]
Next, in step S24, the image signal previously stored in the latest image signal storage area 110b in step S21 is transferred to the reference image signal storage area 110a, and the image signal photoelectrically converted by the AF sensor 5ca is the latest image. It is stored in the signal storage area 110b.
[0127]
Thereafter, the image signal stored in the latest image signal storage area 110b in the previous step S24 is transferred to the reference image signal storage area 110a, and the image signal photoelectrically converted by the AF sensor 5ca in the current step S24 is the latest image. It is stored in the signal storage area 110b.
[0128]
As described above, in step S24, a correlation calculation described later is performed using the image signal stored in the storage unit 110 to obtain the image shift amount X (n).
[0129]
If the image shift amount X (n) is larger than the predetermined level Xc, the determination is made in step S25, and the process branches to step S26 to give a warning that the holding is insufficient.
[0130]
These warnings allow the user to recognize that he / she is unintentionally shaking his camera and take countermeasures by holding the camera with his hands or placing it on something.
[0131]
If the image shift amount X (n) is larger than Xcc which is larger than Xc in step S25, it is considered that the user has taken a completely different angle or changed the composition. Return (Y of S27).
[0132]
If the image signal is stable, step S25 is branched to N, so that a release operation is possible. Thereafter, the exposure sequence in step S30 and subsequent steps is entered.
[0133]
First, focusing and distance measurement are performed.
[0134]
At this time, the measurement of the image signal for distance measurement is performed using both the sensors 5ca and 5cb of the pair of AF sensors 5c, as shown in FIG.
[0135]
The image signals photoelectrically converted by the AF sensors 5ca and 5cb are stored in the reference part image signal storage area 110a and the reference part image signal storage area 110b of the storage unit 110, respectively.
[0136]
Then, using the image signal stored in the storage unit 110, an image shift amount is obtained by correlation calculation described later, and the image shift amount is converted into data corresponding to the subject distance to perform focusing.
[0137]
Next, the exposure time is determined by the luminance information obtained by the image detection in step S3, and exposure is started.
[0138]
During this time, if the camera shakes, camera shake occurs, so acceleration is detected in step S33, and the acceleration g due to shock or the like when the release button is pressed is obtained.
[0139]
When the acceleration g is large, a camera shake photograph is obtained even if the exposure time is short.
[0140]
Even if the acceleration g is small, if the exposure time is long, a camera shake photograph is obtained in this case as well.
[0141]
In order to determine this, the exposure time is counted in step S34, and when the exposure ends (step S35), the speed is obtained from the obtained acceleration g and exposure time tEND.
[0142]
Since the moving amount can be calculated because the speed has changed by the time t and END, if this exceeds the allowable amount ΔY of the lens, the process branches from step S36 to S37 to issue a warning. .
[0143]
As described above, only the change in speed can be understood only by the acceleration, but in the present embodiment, it is first determined that the output <image signal> of the AF sensor does not change to stop at a predetermined position. Based on this, it is possible to accurately determine how much the camera has moved during the exposure.
[0144]
As described above, according to the present embodiment, since the AF sensor is effectively used, the AF sensor is used not only for distance measurement but also for holding check and stores an image signal. Since the memory area is also used for both distance measurement and holding check, no new sensor or memory is required, so the added value of the camera can be increased without incurring an increase in cost or space. .
[0145]
In addition, it can be used in combination with acceleration sensor signals to detect shaking in the X and Y directions to deal with dark scenes and low contrast scenes, and can also be used as a stationary detection sensor to move the camera from the acceleration sensor output. It is possible to accurately calculate the quantity.
[0146]
Accordingly, it is possible to accurately perform camera shake determination after shooting corresponding to the focal length and aperture of the shooting lens and the shutter speed at the time of shooting.
[0147]
Needless to say, if the position of the photographic lens is corrected based on the calculated amount of movement, it can be applied to a camera with an anti-vibration function.
[0148]
FIG. 17 is a diagram for explaining the window shift method of the correlation calculation described above.
[0149]
That is, as shown in FIGS. 17A and 17B, the AF sensors 5ca and 5cb are composed of a plurality of photoelectric conversion elements.
[0150]
Then, the image signals a1, a2,... AN, b1, b2,... BN output from the AF sensors 5ca and 5cb are stored in the areas 110a and 110b of the storage unit 110. Only a1, a2,... AN acquired with a predetermined time difference are stored.
[0151]
Data of a predetermined range (hereinafter, windows) 120a and 120b is extracted from the image signal.
[0152]
As the extraction method, the simplest method is to fix the window 120a and shift the window 120b by one sensor.
[0153]
This is an example, and the number of window data, the shift amount, the shift method, and the like may be changed during distance measurement and camera shake detection.
[0154]
Correlation amount F (n) is obtained by equation (1) using a pair of extracted window data.
[0155]

However, n: shift amount, W: number of data in window, i: data in window No.
k: Calculation area head sensor data No.
FIG. 18 is a correlation data graph showing a correlation value for each shift value.
[0156]
As shown in FIG. 18, the degree of coincidence between the data of the pair of windows 120a and 120b is the highest when F (n) obtained by shifting the window 120b by one sensor is a minimum value (F (n) = Fmin), the shift amount n = nFmin is the relative image shift amount of the subject image.
[0157]
This image shift amount is used as a camera shake amount X (n) in the X direction at the time of camera shake determination, and is used to calculate subject distance data as AF data at the time of distance measurement.
[0158]
As described above, according to the present embodiment, if a holding check mode is set particularly in a shooting scene in which camera shake is a concern, a warning is issued during camera shake so that the photographer can recognize camera shake. As a result, it is possible to shoot without failure due to camera shake.
[0159]
In addition, according to the present embodiment, at the time of holding determination, a sensor used as a conventional distance measurement sensor is also effectively used for camera shake determination, and a memory area for storing an image signal is also used for distance measurement and holding. Since it is also used for checking, it is possible to perform highly reliable camera shake determination without increasing the cost.
[0160]
【The invention's effect】
Therefore, as described above, according to the present invention, when camera shake detection is performed using a distance measuring sensor, it can be realized with higher accuracy and a simpler configuration than before without increasing the memory capacity. A distance measuring device with a blur detection function can be provided.
[Brief description of the drawings]
FIG. 1 (a) is a perspective view showing an external appearance of a camera according to an embodiment of the present invention and an internal structure in which a part thereof is cut out, and FIG. It is a side view which shows the arrangement | positioning relationship between the hard printed circuit board 14 used for embodiment, and a flexible printed circuit board (henceforth a flexible printed circuit board) 7, (c) of FIG. 1 shows the ranging optical system of this invention. It is a figure shown in order to demonstrate.
2A is a block diagram showing a configuration of a control system including an electronic circuit of a camera according to an embodiment of the present invention, and FIG. 2B is a block diagram of FIG. FIG. 6 is a diagram for explaining directions that can be detected by the monolithic accelerometer 3 of FIG.
FIG. 3 is a diagram illustrating an example of a manufacturing process of the acceleration IC 3 in FIG. 2;
4 is a diagram showing a configuration of each part of the acceleration IC 3 manufactured by the manufacturing process of FIG. 3; FIG.
5A is a block diagram illustrating a configuration example of the processing circuit 29, and FIG. 5B is a diagram illustrating an output waveform from the processing circuit 29. FIG.
FIG. 6 is a diagram for explaining the principle of camera vibration detection according to the embodiment of the present invention;
FIGS. 7A and 7B are diagrams for explaining the difference between the output (image signal) of the AF sensor and the output of the acceleration sensor, which is a feature of the present invention.
FIG. 8 is a diagram illustrating a case where the holding check function of the camera according to the embodiment of the present invention is set to one of the shooting modes and can be set only when the user determines that it is necessary. is there.
FIG. 9 is a diagram illustrating an arrangement example of the display segments 6b and 6c in FIGS. 8B and 8C.
FIG. 10 is an external view of the camera 10 according to the first embodiment of the present invention as viewed from the back side.
FIG. 11 is an external view of the camera 10 according to the first embodiment of the present invention as viewed from the front.
FIG. 12 is a diagram showing display control performed by a CPU in a camera with a holding check mode equipped with a sensor based on two detection methods employed in the embodiment of the present invention in a sequence according to a built-in program; It is a flowchart shown in order to demonstrate.
13 is a diagram showing an example of a warning pattern displayed on the in-finder LCD 6a of FIG. 2 (a). FIG.
FIG. 14 is a diagram showing an example of a normal display pattern displayed on the in-viewfinder LCD 6a of FIG. 2 (a).
15 is a diagram showing an example of a camera shake warning display [Pattern 1] displayed on the in-viewfinder LCD 6a of FIG.
FIG. 16 is a diagram illustrating a case where the image signal photoelectrically converted by the AF sensors 5ca and 5cb in the embodiment of the present invention is a reference part image signal storage area 110a, a reference part image signal storage area, or a latest image of the storage unit 110; It is a figure shown in order to demonstrate the form each memorize | stored in the signal storage area 110b.
FIG. 17 is a diagram for explaining a window shift method of correlation calculation in the present invention.
FIG. 18 is a correlation data graph showing correlation values for each shift value in the window shift method of correlation calculation of FIG. 17;
[Explanation of symbols]
14 ... Rigid printed circuit board,
7 ... Flexible printed circuit board (flexible circuit board),
3. Monolithic accelerometer (acceleration IC),
10 ... Camera,
9 ... Photography lens,
8 ... Strobe,
15 ... Viewfinder objective lens,
1 ... One-chip microcomputer (CPU),
2 ... Interface IC (IFIC),
4 ... Memory (EEPROM),
12 ... Connector,
6 ... Display element (LCD),
5 ... Autofocus (AF) sensor,
13 ... Patterns for communication lines and switches,
11 ... warning display part,
101 ... Subject,
102: Image signal,
5d: a light receiving lens,
5c ... sensor array,
20 ... Silicon substrate (IC chip),
21 ... Oxide film,
22 ... polysilicon layer,
22c ... movable electrode,
24, 25 ... another electrode,
23a, 23b ... arms of the movable electrode 22c,
29 ... Processing circuit,
32 ... Carrier wave generator (oscillation circuit),
31 ... Y direction acceleration sensor,
34. Demodulator circuit,
36: Filter circuit,
37 ... PWM signal generation circuit,
5a: Autofocus (AF) section,
5b: Metering unit,
6a: LCD 6a in the viewfinder,
8a ... main capacitor,
11a: resistor 11a,
Switch ... 13a, 13b,
19 ... Shutter,
18 ... motor,
16 ... rotating blades,
17 ... Photo interrupter,
6b, 6c ... display segment,
61 ... finder eyepiece,
65 ... LED for self-timer display,
10a ... Barrier.

Claims (1)

A pair of light receiving lenses for forming a subject image;
A pair of line sensors that photoelectrically convert a subject image formed by the pair of light-receiving lenses and output as an image signal;
Storage means for storing image signals output from the pair of line sensors,
A distance measurement operation is performed based on a pair of image signals output from the pair of line sensors , and a camera shake detection operation is performed based on a change in the image signal output from one of the pair of line sensors every predetermined time. In a distance measuring device with a blur detection function capable of performing
The storage area of the storage means is divided into two, and a pair of image signals output from the pair of line sensors are stored in the divided storage area during the distance measuring operation, and the pair of image signals are stored during the camera shake detection operation. A distance measuring apparatus with a blur detection function , wherein an image signal serving as a reference of an image signal output from one of the line sensors and a latest image signal are stored in the storage area divided into two .

Images