JPH07114053A - Shake-proof camera - Google Patents

Abstract

PURPOSE:To provide the shape-proof camera capable of controlling activation and inactivation of a shake predicting function according to exposure time. CONSTITUTION:This shake-proof camera includes a shake quantity calculating section 13 for calculating the pre-exposure camera-shape quantity of the camera in accordance with shake detecting section 11, a shutter speed determining section 12 for determining at least a shutter speed in accordance with exposure information before exposure, a shutter speed determining section 14 for determining whether the determined shutter speed is faster than the previously determined value or not, a prediction calculating section 15 for predicting the camera- shape quantity during exposure in accordance with the calculated pre-exposure camera-shape quantity at the time the shutter speed is decided to be slower than the prescribed value and a shutter permission deciding section 16 for permitting exposure if the pre-exposure camera-shape quantity at the time the predicted camera-shape quantity or the shutter speed is decided to be faster than the prescribed value is smaller than the predetermined permissible value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-shake camera.

[0002]

2. Description of the Related Art Anti-vibration technology for detecting camera shake and correcting a shake by driving a taking lens by an amount corresponding to the detected shake amount has been well known. However, such an anti-vibration technique has the drawbacks of high cost and a large camera configuration. Therefore, a compact camera or the like uses a simple anti-vibration technique of opening a shutter by detecting a timing with a small blur. For example, Japanese Patent Laid-Open No. 3-218672 discloses a technique of detecting a blur amount, predicting the blur amount during exposure based on the detected value, and permitting exposure if the predicted value is equal to or less than the permissible blur amount. Disclosure. Also, Japanese Patent Application No. 4-01
No. 1225 discloses time series data X (i) of a blur signal,
Using the prediction coefficient A (i),

[0003]

[Equation 1] The technique of performing exposure permission or image stabilization drive based on the predicted blur amount Y is disclosed.

[0004]

However, when the shutter speed is low and the exposure time is long, the blurring amount may change significantly during the exposure. Therefore, the exposure is performed because the current blurring amount is below the permission level. Even if the permission is given, the blurring amount largely changes during exposure, and a satisfactory blurring prevention effect cannot be often obtained. Therefore, at the time of the low speed shutter, it is a very important problem to predict the blurring amount that may occur during exposure based on the current blurring amount.

On the other hand, when the shutter speed is short and the exposure time is short, the blurring amount does not change significantly during the exposure. Therefore, even if the exposure is permitted because the current blurring amount is below the permissible level. A satisfactory anti-shake effect can be obtained.

Therefore, it is meaningless to predict the blurring amount at the time of high-speed shutter, and there is a disadvantage that the shutter time lag becomes longer by the time required for the prediction calculation.

The shake prevention camera of the present invention has been made in view of such a problem, and the purpose thereof is to control the operation and non-operation of the shake prediction function according to the exposure time. To provide an anti-shake camera.

[0008]

To achieve the above object, an anti-shake camera according to the present invention comprises a camera shake amount calculating means for calculating a pre-exposure camera shake amount of a camera based on a camera shake detecting means. Based on the exposure information before exposure, at least the exposure calculation means for determining the shutter speed, the determination means for determining whether the determined shutter speed is higher than a predetermined value, and the shutter speed When it is determined to be slower than a predetermined value, based on the calculated pre-exposure camera shake amount, a camera shake prediction unit that predicts the camera shake amount during exposure, the predicted camera shake amount, or the shutter speed. And an exposure permission unit that permits the exposure when the pre-exposure camera shake amount when it is determined to be faster than a predetermined value is smaller than a predetermined tolerance value.

Further, the anti-shake camera of the present invention, based on the shake detecting means, calculates the pre-exposure camera shake amount of the camera, and the pre-exposure camera shake amount calculated above. A blur prediction unit that predicts the amount of camera shake after a predetermined time from blur detection, an exposure calculation unit that determines at least a shutter speed based on exposure information before exposure, and a blur prediction unit based on the shutter speed. When it is determined that the shake prediction presence / absence determining unit that determines whether or not to operate, and the shake prediction presence / absence determining unit predicts, it is determined whether the predicted camera shake amount of the shake prediction unit is smaller than a predetermined value, When the blur prediction presence / absence determining means determines that no prediction is made, it is determined whether the pre-exposure camera shake amount is smaller than a predetermined value, and exposure is permitted only when it is determined that the pre-exposure camera shake amount is smaller than a predetermined value. Comprising an exposed authorization means for.

[0010]

That is, the anti-shake camera of the present invention calculates the pre-exposure camera shake amount of the camera based on the shake detection means, and at least determines the shutter speed based on the pre-exposure exposure information. Then, it is determined whether or not the determined shutter speed is faster than a predetermined value determined in advance, and when it is determined that the shutter speed is slower than a predetermined value, the exposure is performed based on the calculated pre-exposure camera shake amount. Predict the amount of camera shake. Further, if the predicted camera shake amount or the pre-exposure camera shake amount when it is determined that the shutter speed is faster than a predetermined value is smaller than a predetermined allowable value, exposure is permitted.

Further, the anti-shake camera of the present invention calculates the pre-exposure camera shake amount of the camera based on the shake detection means, and based on the calculated pre-exposure camera shake amount,
The amount of camera shake after a predetermined time from the shake detection is predicted by the shake prediction unit. Next, at least the shutter speed is determined based on the exposure information before the exposure, and based on the shutter speed, it is determined whether or not the blur prediction means is operated. Then, when it is determined to predict, it is determined whether or not the predicted camera shake amount of the blur prediction unit is smaller than a predetermined value, and when it is determined not to predict, whether the pre-exposure camera shake amount is smaller than a predetermined value. It is determined whether or not the exposure is permitted only when it is determined that it is smaller than the predetermined value.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1A is a block diagram showing the basic concept of an anti-shake camera according to the present invention.

This anti-shake camera determines a shutter speed (exposure time) from a shake detection unit 1 that detects a shake caused by a photographer's hand shake, a photometry result, a strobe control mode, a photographing mode, and the like. Based on the exposure calculation unit 2 and the shutter speed from the exposure calculation unit 2, the blur prediction necessity determination unit 3 that determines whether or not the calculation of the blur amount during exposure is necessary.
If it is determined that the blurring prediction is necessary, the blurring prediction unit 4 that predicts and calculates the blurring amount that will occur during exposure in the future based on the blurring amount from the blurring detection unit 1; The exposure permitting unit 5 is configured to permit the exposure based on the blur amount from the blur amount detecting unit 1 or the blur predicting unit 4.

That is, in this anti-shake camera, first,
The amount of blurring that is currently occurring in the camera is detected. Further, it is determined whether or not the blur amount prediction calculation is necessary in relation to the exposure time. If it is determined that the blur amount prediction calculation is necessary, the blur amount prediction calculation is performed, and the exposure is permitted based on the prediction calculation result. Decide whether or not. Further, when it is determined that the prediction calculation of the blurring amount is unnecessary, it is determined whether or not the exposure is permitted based on the current blurring amount.

FIG. 1 (b) is a diagram showing a modification of FIG. 1 (a). The anti-shake camera shown in the same figure determines a shutter speed (exposure time) from a shake detection unit 11 that detects a shake caused by a camera shake of a photographer, a photometry result, a strobe control mode, a shooting mode, and the like. A shutter speed determination unit 12,
A shake amount calculation unit 13 that calculates the shake amount of the camera based on the shake signal from the shake detection unit 11 and the shutter speed from the shutter speed determination unit 12, and the shutter speed from the shutter speed determination unit 12 are also included. In addition, based on the shake amount from the shutter speed determination unit 14 that determines whether or not the calculation of the blur amount during exposure is necessary, and the blur amount from the blur amount calculation unit 13, it will occur during exposure in the future. It is composed of a prediction calculation unit 15 that predicts and calculates a blur amount, and a shutter permission determination unit 16 that determines permission to open a shutter based on the blur amount from the blur amount calculation unit 13 or the prediction calculation unit 15.

That is, in this blurring prevention camera, the blurring amount currently occurring in the camera is detected, and when it is determined that the blurring amount predictive calculation is necessary in relation to the exposure time, the blurring amount predictive calculation is performed. The shutter opening is permitted for an allowable range of blurring that does not affect the captured image.

The basic concept described above will be described in more detail below. FIG. 2 is a configuration diagram in which the anti-shake camera according to the present embodiment is realized by using a microcomputer (CPU), and only those related to the present embodiment are shown here.

The CPU 109 executes the sequence control of the entire camera. R1 and R2 are two-stage release switches, R1 is a first release switch, and R2 is a second release switch. Blur sensor unit 101
Outputs a shake displacement according to a request from the CPU 109. For example, Japanese Patent Application No. 4-149673 by the present applicant.
It is possible to use a combination of a light emitting diode and a photo diode disclosed in, a acceleration sensor, a CCD sensor and the like. The photometric unit 102 is a sensor that measures the brightness of the subject.

The zoom position detector 103 detects the focal length f of the zoom, and includes an absolute position encoder and P.
A means for counting pulses such as I and calculating the relative position can be used.

The AF distance measuring section 104 may be a TTL phase difference type CCD sensor for a single-lens reflex camera, and an active AF type infrared projection PSD light receiving type for a lens shutter. The DX reading unit 105 is a DX contact piece in a patrone chamber of a camera body (not shown). PCV
Reference numeral 110 is a ceramic oscillator that generates a warning sound. The motor driver 106 includes an aperture motor Md (111), a lens driving motor Ml (112), and a mirror up motor M.
m (113) is connected. This is for a single-lens reflex camera, and for a lens shutter, Md111, M
m113 can be omitted. The shutter 107, which is controlled by a plunger or a motor, is driven by a shutter drive unit 108.

FIG. 3 is a flow chart showing the operation when this embodiment is applied to a compact camera. In the figure, first, when R2 is turned on, this flow chart starts. Next, the DX, zoom position, and photometric value are read and exposure calculation is performed (steps S1 to S4). Since the shutter speed is calculated by the exposure calculation in step S4, when the shutter speed is slower than the reciprocal 1 / f of the focal length of the zoom, the PCV 110 issues a warning sound to alert the photographer (steps S5 and S6). ). This is to give a warning to the photographer so as not to cause blurring so as to encourage the photographer to take a photograph. Of course, it goes without saying that the LED in the finder may be used instead of the PCV 110.

In AF sequence, AF distance measuring section 104
Further, the distance measurement value is read, and the amount of lens extension is determined by AF calculation (steps S9 and S10). Next, if R2 is on, the shooting sequence starts. If R2 is not turned on, the above cycle is repeated until R1 is turned off (steps S12 and S13).

In the photographing sequence, after the lens is driven (step S11), the blur amount is measured and the shutter permission is determined by the "blur amount evaluation" subroutine (step S17). As will be described in detail later, when the shutter permission is determined to be OK, the subroutine ends here.

After the shutter permission determination is OK, the shutter is driven (step S18). After that, the film is wound to complete the release sequence (step S19).

Next, two types of "blurring amount evaluation" subroutines in step S17 of FIG. 3 will be described. Figure 4
It is a subroutine of "blur amount evaluation 1". First, the shutter speed is read (step S21), and then the blade data is read (step S22). The blade data stores at least the blade data for the shutter speed. For example, if the shutter speed is 1/32, the bleeders up to 1/32 seconds before the present are stored, for example, every 1 ms.

In the next blur amount calculation, the past blur data for the shutter speed is subtracted from the current blur data,
The blur amount currently occurring is calculated by taking an absolute value or the like (step S23). The term "blade data" here corresponds to camera position information and angle information (θ). It goes without saying that the calculation method of the blur amount is different if the blade data corresponds to the speed information and the acceleration information of the camera.

Next, it is judged whether or not the shutter speed already read is faster than a preset predetermined value (step S24). When the shutter speed is faster than a predetermined value, it is determined that the blur prediction calculation is unnecessary, and the blur amount is corrected based on the focal length of the camera (step S26). This is because the longer the focal length, the greater the amount of blur on the film surface affects the blur of the camera.
As a correction method, if the blur amount is simply equivalent to the focal length f ₀ , it may be multiplied by f / f ₀ . Of course, TTL,
When an AF sensor or the like is used as a blur sensor, the blur amount is already included in the focal length information, so zoom value correction is not necessary.

When the shutter speed is slower than a predetermined value, it is judged that the blurring amount predicting calculation is necessary, and the blurring amount predicting calculation is performed next (step S25). For this prediction calculation, for example, the prediction calculation method disclosed in Japanese Patent Application No. 4-11225 may be used.

After that, the zoom value correction is similarly performed (step S26). Next, it is judged whether or not the corrected blur amount is equal to or less than a predetermined value (step S27). If it is not less than the predetermined value, the bleeder is measured again and the above steps are repeated.

FIG. 5 shows a subroutine of "blur amount evaluation 2". In the embodiment shown in FIG. 5, unlike FIG. 4, the predicted blur angle θ ₂ is calculated from the current blur angle (θ ₁ ) by the formula for obtaining the blur amount Y shown in Japanese Patent Application No. 4-011225, and further, | Θ ₁ −θ ₂ | is calculated to calculate the predicted blur amount (step S 32).

Further, it is not necessary to limit the shutter speed which does not operate the predictive calculation to the high speed shutter. For example, when the accuracy cannot be ensured because the prediction time becomes long at the low speed shutter, the prediction calculation is not operated not only at the high speed shutter but also at the low speed shutter. FIG. 6 shows such an embodiment, in which two predetermined values (first predetermined value <second predetermined value) are provided,
The prediction calculation is executed only when the shutter speed is between the first predetermined value and the second predetermined value.

[0032]

As described above in detail, according to the present invention,
Since it is possible to control the activation / deactivation of the blur prediction function according to the exposure information, the prediction calculation is not performed when the prediction calculation is not necessary in relation to the exposure information, thereby shortening the shutter time lag. You can

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic concept of an anti-shake camera according to the present invention.

FIG. 2 is a configuration diagram in which the blur prevention camera according to the present embodiment is realized by using a microcomputer.

FIG. 3 is a flowchart showing an operation when the present embodiment is applied to a compact camera.

FIG. 4 is a diagram showing a subroutine of blur amount evaluation 1.

FIG. 5 is a diagram showing a subroutine for blur amount evaluation 2.

FIG. 6 is a diagram showing a modified example of a subroutine of blur amount evaluation 1.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Blur detection part, 2 ... Exposure calculation part, 3 ... Blur prediction necessity determination part, 4 ... Blur prediction part, 5 ... Exposure permission part, 11 ... Blur detection part, 12 ... Shutter speed determination part, 13 ... Blur amount Calculation unit, 14 ... Shutter speed determination unit, 15 ... Prediction calculation unit, 1
6 ... Shutter permission determination unit.

Front page continuation (72) Inventor Toshiyuki Matsumoto 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Co., Ltd. (72) Inventor Yoshinori Matsuzawa 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optics Kogyo Co., Ltd. (72) Inventor Toshiro Kikuchi 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Co., Ltd.

Claims (2)

[Claims] 1. A camera shake amount calculation means for calculating a pre-exposure camera shake amount of a camera based on a camera shake detection means, and an exposure calculation means for determining at least a shutter speed based on exposure information before exposure. A determination unit that determines whether or not the determined shutter speed is faster than a predetermined value, and the calculated pre-exposure camera shake amount when the shutter speed is determined to be slower than the predetermined value. Based on this, the shake prediction means for predicting the amount of camera shake during exposure, the predicted amount of camera shake, or the pre-exposure camera shake amount when it is determined that the shutter speed is faster than a predetermined value is predetermined. An anti-shake camera, comprising: an exposure permission unit that permits exposure when it is smaller than an allowable value. 2. A camera shake amount calculation means for calculating a pre-exposure camera shake amount of a camera based on the camera shake detection means, and a camera after a predetermined time from the camera shake detection based on the calculated camera shake amount before exposure. A blur prediction unit that predicts a blur amount, an exposure calculation unit that determines at least a shutter speed based on exposure information before exposure, and a decision whether to operate the blur prediction unit based on the shutter speed. When the blur prediction presence / absence determining unit and the blur prediction presence / absence determining unit determine to predict, it is determined whether the predicted camera shake amount of the blur prediction unit is smaller than a predetermined value, and the blur prediction presence / absence determining unit makes a prediction. If it is decided not to do so, it is determined whether or not the pre-exposure camera shake amount is smaller than a predetermined value, and an exposure permission unit that permits exposure only when it is determined to be smaller than the predetermined value. An anti-shake camera that has been characterized.