JP2913511B2 - Camera with camera shake prevention function - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera having a camera shake prevention function, and more specifically, to a camera having a shutter time closest to the photographer's intention. The present invention relates to a camera having a camera shake prevention function capable of appropriately and reliably preventing camera shake shooting.

[Conventional technology]

A technique for obtaining a photograph free of a camera shake phenomenon by controlling the exposure start timing (exposure timing) has already been proposed in, for example, JP-A-63-53531.

This technology detects the camera shake speed, finds the peak value of the camera shake from this detection signal, and starts exposure near the time when this peak value occurs, thereby preventing the image shake phenomenon on the film surface. It is assumed that.

On the other hand, an attempt to prevent camera-shake shooting under the condition that the shooting is performed with the shutter time closest to the photographer's intention has already been proposed in, for example, Japanese Patent Application Laid-Open No. 63-53526.

In this technology, a plurality of acceleration sensors are installed in a camera, the amount of camera shake generated at the time of a shutter release is detected using these acceleration sensors, and a photographer's shake is detected based on the detected camera shake amount. The shutter time closest to the intention is set to prevent camera shake shooting during shooting.

That is, first, the four acceleration sensors whose sensitivity axes are directed in the optical axis direction of the photographing lens and in the direction orthogonal thereto are divided into two points separated in the horizontal direction and two points separated in the vertical direction on the camera side. And one for each.

On the other hand, a measurement reference time required to detect the camera shake amount is set immediately before the shutter release, and this measurement reference time is divided into a plurality of detection times in time series by a unit time corresponding to a desired shutter second. , The amount of camera shake occurring within each of the divided detection times is obtained.

Then, a maximum peak value and a minimum peak value in the camera shake amount at each of the obtained detection times are obtained, the difference is calculated, and the image shake speed on the film surface is calculated by using the calculated value. Predict stochastically.

Then, based on the image shake speed, a shutter time which is the closest to the desired shutter time and at which the image shake speed on the film surface is equal to or less than the allowable value is determined by trial and error. That is, shooting is performed at the shutter time obtained finally.

By the way, when trying to obtain a photograph without camera shake, it is desirable to determine the exposure start time at the shutter time so that the peak time of the camera shake amplitude coincides with the center time of the exposure time zone related to the shutter time. Under such a concept, an attempt has already been made to control the exposure start time at the time of shutter release to obtain a photograph without camera shake.

For example, as described above, the technique disclosed in Japanese Patent Application Laid-Open No. 63-53531 utilizes a configuration in which a differentiating circuit or an integrating circuit and a phase shift filter are combined to realize this thinking power. I have.

[Problems to be solved by the invention]

Since the camera shake speed and shutter speed change variously, depending on these values, the
As described in Japanese Patent Application Laid-Open No. 63-53531, an image blur phenomenon occurs even if exposure is started near the point of time when the peak value of camera shake occurs. Therefore, some other effective means must be used in order to reliably prevent camera shake imaging.

On the other hand, as compact cameras with high-power zooms with focal lengths exceeding 100 mm have become widespread recently, it is well anticipated that users unfamiliar with the camera will have more opportunities to take high-power cameras. Due to the fact that the F value of the photographing lens becomes dark, it is expected that camera shake photographing frequently occurs at a shutter time of 1/30 to 1/125 sec.

For this reason, it is particularly desired that a camera shake preventing device having a certainty with respect to the shutter time of 1/30 to 1/125 sec appears.

By the way, the present inventors conducted a mode experiment of camera shake photographing and tried to analyze the mechanism of occurrence thereof, and found that the image shake phenomenon on the film surface was accidental and nonuniform in size. did.

In normal hand-held shooting, on the film surface, an image shake speed that changes with low-frequency vibration of 2 Hz or less and an image shake speed that changes with almost regular but non-constant amplitude of approximately 10 Hz occur. Became clear.

In addition, it was also confirmed that an image blurring rate that causes a hand-shake phenomenon that can be observed on a photograph, which changes due to a vibration of about 10 Hz, caused by shaking of a finger at the time of shutter release.

Therefore, in order to prevent camera shake shooting, a range in which the image shake speed which changes with a vibration of approximately 10 Hz where the amplitude is not constant can be practically tolerated (hereinafter referred to as “camera shake allowable range”).
It is an essential condition to keep it within.

This means that the conventional method of stochastically predicting the image blur phenomenon on the film surface from the camera shake speed immediately before exposure and trying to prevent camera shake photography cannot provide an effective and appropriate camera shake photography prevention means. That means essentially.

Also in this regard, some other effective means must be established in order to reliably prevent camera shake shooting.

Also, as in the device disclosed in Japanese Patent Application Laid-Open No. 63-53531, a configuration in which a differentiating circuit or an integrating circuit and a phase shift filter are combined becomes complicated as a device, and thus such a complicated configuration is required. The use thereof is significantly disadvantageous in terms of cost and space under conditions where more diversified functions are required in a compact camera as in recent cameras.

For this reason, there is a demand for a camera having a camera shake prevention function that is simple in configuration and that can effectively and appropriately prevent camera shake shooting.

The present invention has been made in view of such circumstances,
The objectives are shooting conditions intended by the photographer,
In particular, while respecting the exposure timing and the shutter time as a basis, the exposure timing with a small image shake amount is determined, and if the image shake amount still does not fall within the range of the allowable image shake amount, change the shutter time, An object of the present invention is to provide a camera provided with a camera shake prevention function capable of effectively and appropriately preventing camera shake shooting.

Another object of the present invention is to provide a camera having a camera shake prevention function capable of effectively and appropriately and reliably preventing camera shake shooting while having a simple configuration while respecting the user's intention.

[Means for solving the problem]

In order to achieve the above object, an invention according to claim 1 (hereinafter referred to as a “first invention”) is a film camera based on camera shake speed information obtained from camera shake speed detection means provided in the camera. Image shake speed calculating means for calculating the image shake speed of the surface; detecting a peak value of the image shake speed output when the shutter release button is pressed down to the second stroke by the image shake speed calculating means and a point in time when the peak value occurs Image shake speed peak value detecting means and the image shake speed according to a modeled simple vibration having a frequency of approximately 10 Hz, determining the shutter time by manual input or based on input of photometric information, aperture information, film sensitivity information, etc. A plurality of unit sections are set in advance by chronologically dividing at least a quarter cycle section from the point of occurrence of the peak value to the point of image shake velocity 0 with a predetermined time width, and The exposure time is divided into a plurality of unit sections by dividing the shutter time by the predetermined time width, and the predetermined unit section close to the image shake speed peak value and within the quarter period section is exposed first. A start interval is set, an exposure start signal is output during the exposure start interval, an exposure end signal is output when the shutter time has elapsed since the exposure start signal was output, and an exposure start interval shift signal was received. At this time, the exposure start section is appropriately changed to a direction in which the exposure start section is delayed.
If the predicted image shake amount does not become smaller than the allowable image shake amount even after shifting to a predetermined unit period within the four cycle period, an exposure period determination unit that changes the shutter time to a shorter time, Image shake amount calculating means for calculating a predicted image shake amount of each unit section belonging to a periodic section as a function of the peak value of the image shake speed, and calculating a predicted image shake amount of the entire exposure section; Image blur determining means for outputting the exposure start section shift signal to the exposure section determining means when a predicted image shake amount of the entire exposure section obtained by the amount calculating means is larger than a preset allowable image shake amount. And shutter drive means for receiving the exposure start signal from the exposure section determination means to open a shutter, and receiving the exposure end signal to close the shutter. It is a thing.

The invention according to claim 2 (hereinafter referred to as "second invention") calculates an image shake speed on a film surface based on camera shake speed information obtained from a camera shake speed detecting means provided in the camera. Image shake speed calculating means, and a peak value of the image shake speed output when the shutter release button is depressed to the second stroke by the image shake speed calculating means, and an image shake speed peak value detection for detecting a point in time when the peak value occurs. Means and manual input or based on the input of photometric information, aperture information, film sensitivity information, etc., determine the shutter time, and divide the shutter time by a predetermined time width to calculate the number of exposure sections, approximately 10 Hz The number of quarter-period sections set in advance by dividing the section from the occurrence of the peak value of the image shake velocity of the image shake single oscillation having the frequency to the time of the image shake velocity 0 value by the predetermined time width And said An exposure start section is calculated from the relationship with the number of exposure sections so that the exposure section falls into a region where the image shake speed is low, and an exposure start signal is output in the exposure start section. Exposure end signal is output at the time when the second time has elapsed, and when the shutter time shift signal is received, the exposure time is changed in a direction to shorten the shutter time, and the exposure section determining means for performing each of the processes is provided. Image shake amount calculating means for calculating a predicted image shake amount of each unit section belonging to the four period section as a function of the peak value of the image shake speed, and calculating a predicted image shake amount of the entire exposure section; When the predicted image shake amount of the entire exposure section obtained by the shake amount calculation means is larger than a preset allowable image shake amount, an image shake signal for outputting the shutter time shift signal to the exposure section determination means. And a shutter driving means for receiving the exposure start signal from the exposure section determining means, opening a shutter, and receiving the exposure end signal to close the shutter. It is.

According to a third aspect of the present invention (hereinafter referred to as a “third invention”), the image blur determining means determines the predicted image blur amount of the entire exposure section and the allowable image blur amount stored in the allowable image blur amount storage unit in advance. When the predicted image shake amount is larger than the expected image shake amount, an exposure start prohibition signal is output to the exposure section determination means.

[Action]

The image shake speed calculating means of the camera having the camera shake preventing function configured as described above is configured to calculate the image shake speed based on the camera shake speed information detected by the camera shake speed detecting means provided in the camera. The image shake speed of the film surface is calculated, and the image shake speed peak value detecting means for monitoring the image shake speed detects the peak value of the image shake speed and the point of occurrence of the peak value, and sends this signal to the exposure section determining means. Send out. The exposure section determining means determines the shutter time to be exposed by manual input or based on input of photometric information, aperture information, film sensitivity information, and the like, and determines the image shake speed according to the modeled single vibration having a frequency of approximately 10 Hz. And a plurality of unit sections are set in advance in a time-series manner with a predetermined time width during a 1/4 cycle from the peak value generation time point to the image shake speed 0 point, and the shutter time is set to a predetermined value. Dividing the exposure section into a plurality of unit sections by dividing by the time width,
A predetermined unit section of the cycle section is set as the first exposure start section. Then, the exposure section determining means outputs an exposure start signal to the shutter driving means when the exposure start section arrives after the occurrence of the peak value, opens the shutter, and starts exposure. The exposure start section is set to a unit section at a time point that is not too late from the time point at which the peak value occurs so that the exposure starts as soon as possible after the shutter release operation.

On the other hand, the image blur amount calculating means predicts and calculates the predicted image blur amount of each unit section belonging to at least the quarter period section as a function of the peak value of the image blur speed. Then, of the exposure sections determined as described above, over the entire section from the exposure start section to the exposure end section, the predicted image shake amount is added to calculate the entire predicted image shake amount.

The overall predicted image shake amount is compared with an allowable image shake amount stored in advance by the image shake determination means. If the predicted image shake amount is larger, the exposure start section is appropriately set to the exposure section determination means. If a signal that shifts in the direction of delay is given and the predicted image shake amount is larger even if this exposure start section is delayed by a predetermined number, the shutter speed is shifted in the direction of shortening the shutter time, and conversely, the predicted image shake amount is Is smaller or equal, exposure is performed at the determined shutter time.

The camera having such processing means realizes photographing without camera shake while respecting the intention of the operator of the camera. The above is the operation of the first invention.

The exposure section determining means according to the second and third inventions determines a shutter time to be exposed by manual input or based on input of photometric information, aperture information, film sensitivity information, and the like. Is divided by a predetermined time width to obtain the number of exposure sections, and the number of exposure sections and the time from the occurrence of the image shake velocity peak value of the image shake single vibration having a frequency of approximately 10 Hz to the time of the image shake velocity 0 value 1/4 cycle section divided by the predetermined time width in advance and stored
An exposure start section is calculated from the relationship with the number of cycle sections so that the exposure section falls in a region where the image blurring speed is low. And
The exposure section determination means outputs an exposure start signal to the shutter driving means when the exposure start section arrives after the peak value is generated, opens the shutter, and starts exposure. The exposure start section is set so that the shutter closing time point is a time point at which the image shake speed of the single image shake is zero or a time point in the vicinity thereof in order to reduce the influence of camera shake.

On the other hand, the image blur amount calculating means predicts and calculates the predicted image blur amount of each unit section belonging to at least the quarter period section as a function of the peak value of the image blur speed. Then, of the exposure sections determined as described above, over the entire section from the exposure start section to the exposure end section, the predicted image shake amount is added to calculate the entire predicted image shake amount.

This overall predicted image shake amount is compared with the allowable image shake amount stored in advance by the image shake determination means. If the predicted image shake amount is larger, the shutter time is shortened by the exposure section determination means. Anticipate a signal that will shift in the direction of
Exposure start is prohibited. Conversely, if the predicted image shake amount is smaller or equal, exposure is performed at the determined shutter time.

Cameras having such processing means realize photographing without camera shake.

〔Example〕

First, prior to describing an embodiment of a camera having a camera shake prevention function according to the present invention, its working principle will be described.

The present inventors have conducted intensive studies and experiments on vibration having a frequency of about 10 Hz, which is not constant and has an amplitude related to an image shake speed that causes a camera shake phenomenon. Even in the case where the amplitude is not constant, the time in the 1/4 cycle from the generation of the peak value of the amplitude (speed) related to the vibration to the time of the amplitude 0 is 2
In the case of vibrations as short as 5 ms, if the peak value of the amplitude and its occurrence time can be known, it is confirmed that the transition of the image blur speed in each quarter cycle after the peak value occurrence time can be specifically defined. Obtained.

In this case, each quarter cycle after the occurrence of the peak value of the amplitude related to the vibration of 10 Hz is 25 ms (approximately 1/30 sec of the shutter time).
= 33 ms) is convenient when performing exposure calculations with the Apex system. In addition, in this case, the peak value of the amplitude and the point in time when the peak value occurs can be detected. Since it is technically sufficiently possible to analyze the transition of the image blur speed in each quarter cycle, etc., if these confirmation facts are used, an effective and appropriate camera shake prevention function, especially 1 / It has been concluded that it is extremely advantageous to realize a camera provided with a camera shake prevention function for a shutter time of 30 to 1/125 sec.

Therefore, in the present invention, as shown in FIG. 3, the transition of the above-mentioned image blur velocity, which is the root of the camera shake phenomenon, is first modeled as, for example, a simple vibration (amplitude is indefinite) having a regular frequency of 10 Hz, The transition of the image shake velocity | V _f | according to this modeled simple vibration was regarded as the transition of the predicted image shake velocity on the film surface.

Next, the image shake velocity | V _f that changes with this modeled simple vibration
| From the shutter release operation peak value generating point tp ₁ during the, between 1/2 cycle extending through the point t ₇ of the image blur zero velocity value to the next peak value generating time tp _2, very short predetermined time width Δ
The unit sections a _{1 to} a ₁₂ composed of a plurality of unit small areas are set in time series by dividing by t.

For example, as shown in FIG. 3, 1 m of the occurrence point tp ₁ of the earliest peak value | Vp ₁ | obtained by searching for the image shake velocity | V _f |
After s, the division start time t ₁ is set, and this division start time t ₁
Next peak value from | Vp ₂ | of the time just before the occurrence time tp ₂ t
The interval up to ₁₃ is divided in time series with a predetermined time width Δt = 4 ms, for example, and a total of 12 unit sections a _{1 to} a ₁₂ are set.

In this case, the first six unit sections a _{1 to} a ₆ are formed in the time domain before the time point t _{7 of} the image blur velocity 0 value, and in the time domain after the time point t ₇ of the image blur velocity 0 value. , the late six unit intervals a ₇ ~a ₁₂ is formed.

Then, the image shake speed (the average image shake speed of the unit section) of the twelve unit sections a _{1 to} a ₁₂ or the unit of each unit section obtained by multiplying the image shake speed by a predetermined time width Δt (= 4 ms). The amount of image blur l _{1 to} l ₁₂ is determined by the peak value | Vp _{1 of} image blur speed | V _f |
Is calculated and set predictively as a function value of |

As a specific setting method in this case, first, the first half 6
One of the prediction image blur amount l ₁ to l ₆ unit segment a ₁ ~a ₆ is
As described above, it is predictively obtained as a function value of the peak value | Vp ₁ |, and the result is stored in the memory addresses M _{1 to} M ₆ of the predicted image blur amount storage means. Here, the number of memories in the quarter cycle section or the number of quarter cycle sections is M.

The predicted image shake amount l of the latter six unit sections a _{7 to} a _12
7 For to l ₁₂ is image blur velocity | V _f | because conceivable and that the transition is absolute value almost longitudinal symmetrical with respect to the time t ₇ of the image blur zero velocity value, in particular calculating the value Instead, as shown in Table 1 below, each of the first six predicted image blur amounts l ₁
Ll ₆ as the predicted image blur amount l ₆ ll ₁ rearranged in the reverse order from the time t ₇ of the image blur speed 0 value, and the above-described memory address M ₁
Read from ~M _6, to be stored in the memory address M ₇ ~M _12.

In this case, M ₁ is a first memory address used to predict the image shake amount during exposure (address).

Timing of starting exposure by the shutter, interval n ₁ to start this case exposure is, in the first and second invention, first, 1 ms of n ₁ = 1, i.e. the peak value occurs when tp ₁
Set as the first unit interval a ₁ starting from time t ₁ later.
The time to set to t ₁ is to arrive at a relatively early point in time of the shutter release operation, because a time closest to the intention of the shutter timing of the photographer.

However, this exposure start section is not fixed, and when the exposure is started in the initially set exposure start section n ₁ = 1, the predicted image shake amount l in the entire exposure section is larger than the allowable image shake amount. If it is larger, the exposure start section is shifted in the direction of being sequentially delayed by one section, and the shift operation is repeated until the predicted image shake amount 1 becomes smaller.

However, the results went by shifting the exposure start interval n _1, the exposure start section n ₁ is, when led to the state as shown in the following equation (1), the shift operation is stopped.

n ₁ = M− (ΔM / 2) (1) Here, M is a value obtained by dividing a / 4 cycle section by a predetermined time width Δt (4 ms in this embodiment), and is a / 4 cycle section. Is the number of exposure sections, and ΔM is a value (To / Δt) obtained by dividing the shutter time (To) by the predetermined time width Δt, which means the number of exposure sections, in other words, the shutter time It means the number of memories necessary for estimating the image blur amount at the time (To).

To that so as to terminate the shift operation when that the status of the equation (1), the exposure start interval n _1, is shifted so as to [M- (.DELTA.M / 2)] is greater than the numerical In other words, the exposure section (the number of exposure sections ΔM) is shifted from a region where the image blurring speed | V _f |

According to the principle of the present invention, for example, the shutter time (To) is 16
If it is set to ms (corresponding to 1/60 sec), M is 6, as described above, and Δt is 4 ms, so ΔM = 16 ms / 4 ms = 4 n ₁ = M−ΔM / 2 = 4 In FIG. 3, the first exposure start section n ₁ is a unit section a ₁ , so that the exposure start time is t ₁ , and the total image shake amount l in the exposure sections a _{1 to} a ₄ is Becomes When it is determined that the total predicted image shake amount is larger than the allowable image shake amount, the exposure start section is sequentially shifted. However, n ₁ = 4, that is, the shift is performed in a direction slower than the unit section a _4. However, if the predicted image shake amount l is larger than the allowable image shake amount, the predicted image shake amount l does not decrease even if the above-described exposure start section shift operation is further advanced, so that the limit of the exposure start section n ₁ , that is, determining the timing of starting exposure at the time t _4.

Here, the principle of calculating the predicted image shake amount l will be described.

As described above, each unit section a ₁ of the six quarter period sections
The image blur amount l ₁ to l ₆ for each unit section a ₁ ~a every _six multiplied by a predetermined time width Δt in image blur speed or the image shake speed of ~a _6,
As a function of the peak value | Vp ₁ | of the image shake velocity | V _f |
Calculated by the calculation formula shown in Table 1 below, these values are stored in the memory address M ₁ ~M _6.

Note that the predicted image shake amount l _{7 to} l in the quarter period section after time t _{7 is
12, it} is considered that the transition of the image blur velocity | V _f | becomes almost symmetrical in absolute value with respect to the time point t _{7 at} which the image blur velocity is zero, as described above. The six predicted image shake amounts l _{1 to} l ₆ are read out from the memory addresses M _{1 to} M ₆ and rearranged in the reverse order from t ₇ of the image shake speed 0 value to obtain the predicted image shake amounts l _{6 to} l _1. stored in the memory address M ₇ ~M _12.

The method of calculating the predicted image blur amount will be described using a calculation example of the predicted image blur amount l ₁ of the first unit section a ₁ of the quarter cycle section as a representative example. Becomes (Note that this calculation formula calculates the earliest peak value | Vp ₁
| Vp ₁ | = | Vp | The predicted image shake amount l calculated in this manner differs depending on the set exposure section (exposure area of the shutter time To), and is expressed by the following equation (2) when expressed by a general equation. .

Here, n ₂ is an exposure end section, which is obtained by the following equation (3).

n ₂ = n ₁ + ΔM−1 (3) By the way, as described above, even if the exposure start section n ₁ is shifted to a predetermined unit section, the predicted image shake amount 1 of the entire exposure section is smaller than the allowable image shake amount. If not, set the shutter speed to a high speed side by a predetermined step (in this example, 0.
5), and each time, the predicted image blur amount 1 is compared with the allowable image blur amount. Even if this shift is performed a predetermined number of times (in this case, three times), if the predicted image shake amount 1 does not become smaller than the allowable image shake amount, the shift operation at the time of the shutter second is terminated, and after a predetermined time has elapsed, the image Remeasure the run-out speed | V _f | and perform the same procedure.

By using such an operation principle, the influence of the image blur phenomenon caused by hand-held shooting is reduced as much as possible,
Camera shake shooting can be prevented.

On the other hand, third and fourth exposure start timing of the shutter in the camera having a hand shake picture-taking preventing function according to the present invention, the section n ₁ to start this case exposure, the following (4)
Determined by the formula.

n ₁ = M−ΔM + 1 (4) The basis for determining the exposure start section n ₁ as in the above equation (4) is that if ΔM is smaller than 1/4 period section number M, the image shake velocity value becomes 0. it is for terminating the exposure at the time point t _7, in order to reduce the influence of camera shake.

According to the principle of the present invention, for example, the shutter time (to) is 16
If it is set to ms (corresponding to 1/60 sec), M is 6 as described above, and Δt is Δt = 4 ms, so ΔM = 16 ms / 4 ms = 4 n ₁ = 6−4 + 1 = 3 next, time t ₃ in Figure 3 is the exposure start time tn _1.

The predicted image shake amount 1 at this time is Becomes

On the other hand, if the shutter time To is 24 ms, then n ₁ <1, and if To = 28 ms, n ₁ = 0, so that the exposure start section is uniformly set to n ₁ = 1 and newly set to n ₂ = M− (ΔM−6) +1 (6) to determine the exposure end section n ₂ . This is the number of exposure sections Δ
Since M exceeds the number M of quarter-period sections, to read the predicted image blur amount of the exceeded section from the memory, the address of the image blur amount l ₁ + l ₆ of each unit section of the quarter-period section is used. It is necessary to decide.

That is, the predicted image shake amount 1 when the number of exposure sections ΔM exceeds the number M of quarter cycle sections is obtained by the following equation (7).

To explain this with specific numerical values, shutter time To = 32
In the case of ms, since n ₁ <0, n ₁ = 1 and ΔM =
Since it is 8, n ₂ = 5. Therefore the exposure start section n ₁ is the unit interval a _1, the exposure from the exposure completion interval n ₂ = 5 is carried out toward between times t ₁ ~t _9, the amount of deflection prediction image of unit sections l ₇ = Since l ₆ and l ₈ = l ₅ , from the memory,
l _{1 to} l ₆ and l _{5 to} l ₆ will be read.

That is, the predicted image shake amount l of the entire exposure section in this case
Is 1 = l ₁ + l ₂ + l ₃ + l ₄ + l ₅ + l ₆ + l ₆ + l ₅

By such a procedure, the image blur amount l on the film surface at each shutter time is obtained, and this l value is compared with the permissible image blur amount. Then, the following process (a) or (b) is performed. That is, (a) For example, in a case where the set shutter time T ₀ is 16 ms, the shutter time T ₀ is increased by one stage and T ₀ = 8 ms (1
/ 125 sec), and a new image blur amount l = l ₅ + l ₆ is obtained based on the newly set second, and this image blur amount l
And the allowable image shake amount.

Then, by repeating such a procedure, to determine the T ₁ time the final shutter speed that satisfies the [l value ≦ acceptable image blur amount], to release the shutter when the final seconds.

(B) The comparison result between the l value and the permissible image shake amount is as described above [l
Value> permissible image shake amount], | V _f | is continuously detected, and the start of exposure is prohibited until the next peak value point | tp |

The configuration is as follows.

By using such an operation principle, it is possible to prevent an image blur phenomenon caused by hand-held shooting.

Next, the working principle of a camera having a camera shake prevention function according to the invention related to the first to third inventions will be described with reference to FIG.

In the present invention as well, the transition of the above-mentioned camera shake speed, which is the root of the image shake phenomenon, is first modeled as, for example, a simple vibration having a regular 10 Hz frequency (amplitude is indefinite), and the image shake speed | The transition of V _f | was regarded as the transition of the predicted image blur speed on the film surface.

Then, at the time of 1/4 cycle from the peak value generation point (detection time point) tp of the image shake speed | V _f |, that is, 25 ms after the peak value generation point tp, the exposure timing related to all shutter seconds The reference time point to was set, and the exposure timing of the shutter time T was set such that the central time point of the exposure time zone (ms) forming the shutter time T almost coincides with the reference time point to.

In this case, the peak value of this image blurring speed | V _f |
The quarter period after tp corresponds to the decay period of the modeled simple oscillation, and the change of the image shake velocity | V _f |
Since the quarter period before and after the time point of the velocity value 0 can be considered to be almost symmetrical in absolute value, if the image shake velocity | V _f
If the peak value | Vp | of the | is within the permissible image blur speed range, the peak value generation point tp in the rear quarter from the peak value generation point tp in the front quarter period.
Within a time period of 50 ms until the peak value of the 周期 cycle, the predicted image blur speed | V _f | at each time point falls within the allowable image blur range.

Therefore, the exposure time zone for all shutter time T is
If the time is set within ms, it is possible to prevent a harmful camera shake phenomenon on the film surface, and it is possible to effectively, reliably and surely prevent camera shake shooting.

Incidentally, the image blur amount l on the film surface, the detection sampling time of the image blur speed is t (constant), the image shake speed of each sampling | V _f i | if l = Σ | V _f i | are those obtained as the sum during the exposure time × t ... (8), also, image shake speed of above | V _f | for the transition has been defined as the simple harmonic oscillation of 10 Hz, the image Run-out speed ｜ V _f
And the shutter speed T, the image blur amount l is used to calculate the image blur speed | V _f
|

Therefore, the aforementioned image blur allowable range is set to the allowable image blur speed value.
It can be set as Vs.

Further, the allowable image shake velocity value Vs changes depending on the value of the shutter time (T) used (set or determined) at each time. Therefore, for example, the allowable image shake speed value Vs is interlocked with the setting operation of the shutter time. The setting is made for each shutter time scheduled to be used.

On the other hand, in normal hand-held shooting, the shutter time T is T ≧ T.
It is empirically known that camera shake is likely to occur more frequently at 40 ms, so in this case, similar to an ordinary camera, a camera shake warning is notified to the user, or measures such as forcibly prohibiting the shutter release are provided to the user. Take steps to prevent camera shake shooting.

Based on such a premise, the fifth and sixth inventions have established the following working principle.

First, using appropriate means, it is checked whether or not the shutter time To set in the camera is To ≧ 40 ms, and T <
Only in the case of 40 ms, prior to the shutter release, the image shake velocity | V _f | changing in the modeled single vibration is searched to detect its peak value | Vp |.

If the peak value | Vp | and the occurrence time point tp are detected, then the peak value | Vp | is compared with the allowable image shake velocity value Vs- ₀ specific to the set shutter time To. , | Vp | <Vs− ₀ , and if this result is obtained, the shutter is released using the set shutter time To as it is.

The exposure timing at that time is determined such that the exposure start time ts of the shutter time To is equal to the time when a predetermined time determined by the set shutter time has elapsed from the peak value generation time tp. That is, the exposure start time of the set shutter time To
ts is determined so as to be 25- (To / 2) (ms) after the peak value generation time tp.

On the other hand, when the comparison result between the peak value | Vp | of the image shake speed | V _f | and the allowable image shake speed value Vs- ₀ of the set shutter time To becomes | Vp | ≧ Vs- ₀ The user can take three countermeasures.

One such case is that the shutter release is directly featured.

In this case, the peak value | Vp | of the next image shake velocity | V _f |
When is searched again, this peak value | Vp | is again compared with the allowable image shake velocity value Vs- _0, and if there is an opportunity to obtain the result of | Vp | <Vs- ₀ , a predetermined time Thereafter, exposure will be performed as described later.

The second case is to try the shutter release again.

The third case is a countermeasure in a case where the comparison result of | Vp | <Vs− ₀ cannot be obtained after any number of attempts. In this case, the shutter time to be set is changed to a higher shutter time. select the T ₁ is to change it.

That is, if the shutter speed is increased, the allowable image shake speed value Vs- _{1 at} this time becomes larger than the allowable image shake speed value Vs- ₀ at the shutter time To set before, and | Vp | <Vs _{This is because the} probability of obtaining the comparison result of _-1 increases.

When T ≧ 40 ms, the configuration is such that the user is notified of a camera shake warning or the like, as described above.

Hereinafter, the configuration of an embodiment of a camera having a camera shake prevention function according to the present invention will be described with reference to FIGS. 1 to 3.

FIG. 1 is a block diagram showing the overall configuration of an embodiment of a camera having a camera shake prevention function according to the present invention, and FIG. 2 is a layout explanation showing an arrangement of a pair of acceleration sensors in FIG. FIG. 3 is a principle explanatory diagram for explaining the operation principle of the present invention.

In each of the figures, reference numeral 1 denotes a camera body having a camera shake prevention function of the present invention, 2 denotes a photographic lens, 3 denotes a photographic optical axis of the photographic lens 2 in a normal state, and 3 'denotes a maximum angle due to a shutter release operation. The photographing optical axis 4 when tilted by θ is the film surface.

Reference numerals 5 and 6 denote camera shake speed detectors as a pair of camera shake speed detectors disposed at a predetermined distance L on the camera body 1 along the photographing optical axis 3, both of which are, for example, semiconductor accelerations. It comprises sensors 5a, 6a and acceleration integrators 5b, 6b connected to these acceleration sensors 5a, 6a, respectively.

Further, each of the acceleration integrators 5b, 6b is connected in parallel to a general control unit 7, which will be described later, and the corresponding acceleration sensors 5a, 6a
Is converted into _two speed signals (S ₁ ) and (S ₂ ) from the measured acceleration value signal output from the controller and output to the general controller 7.

Each of the acceleration integrators 5b and 6b is configured as a circuit element having a filter function capable of cutting a DC component from the corresponding acceleration sensor 5a or 6a.

The general control unit 7 controls the entire camera system provided with a camera shake prevention function based on the above-described operation principle. As will be described in detail later, an appropriate detection required for the operation and control of each unit is performed. It is composed of a microcomputer having functions, arithmetic functions, comparison functions, judgment functions, storage functions, and the like.

Reference numerals 8 and 9 denote a normally-open first-stage switch and a second-stage switch respectively connected to the input terminal of the general control unit 7, and a first-stage stroke and a second-stage stroke of a shutter release button (not shown). Are configured to be closed respectively.

Reference numeral 10 denotes various exposure information units that output photometric information, aperture information, film sensitivity information, shutter speed information by external operation, and the like (hereinafter, these are collectively referred to as “various exposure information”), and output, for example, photometric information. Metering device, aperture mechanism to output aperture information, DX to output film sensitivity information
Functional members such as a contact point and a shutter speed setting mechanism for outputting shutter speed information are included.

Reference numeral 11 denotes a shutter drive unit that receives an exposure start signal and an exposure end signal from the general control unit 7 and opens and closes the shutter 12.

13 is when a hand shake signal or the like is received from the general control unit 7,
Preliminary notice before shooting operation that there is a possibility of camera shake due to sound or light, notification that the camera is searching for exposure conditions that do not cause camera shake, or that image shooting has caused image blurring etc. This is the alarm unit.

Next, the internal configuration of the integrated control unit 7 will be described more specifically.

Reference numeral 14 denotes an image shake speed calculation unit as image shake speed calculation means, which receives two speed signals S ₁ and S ₂ output from a pair of camera shake speed detectors 5 and 6, and receives an image shake speed on the film surface 4. |
V _f | can be calculated.

That is, the image blurring speed | V _f | is calculated by the following equation.

| V _f | = (f / L) × | S ₁ −S ₂ | (9) where L: arrangement interval of acceleration sensors 5 a and 6 a S ₁ : speed value detected by camera shake speed detector 5 S ₂ : Speed value detected by the camera shake speed detector 6.

The arithmetic expression (9) is derived from a general expression for calculating the amount of image blur on the film surface 4, where t is the focal length of the taking lens 2.

Reference numeral 15 denotes an image shake speed peak value detection unit as image shake speed peak value detection means, which receives the image shake speed signal _Vf and generates a third image shake speed signal.
The peak value | Vp ₁ | and the peak value generation point tp ₁ shown in the figure are detected and output.

Reference numeral 16 denotes an exposure section determining section as exposure section determining means. In the first and second inventions, first, various exposure information sections are provided.
The first shutter time (To) is determined from the shutter speed information generated based on, for example, shutter speed information or photometric information directly set by manual input, aperture information, film sensitivity information, and the like, and , The peak value of the image blur speed detected by the image blur speed peak value detector 15 | Vp
₁ | Immediately after generation time tp ₁ of the unit section a ₁ earliest quarter cycle intervals (this 1ms after the example), to determine the first exposure start section n _1. Then, an exposure start section shift signal S _f , which will be described later,
If but not inputted from the image blur determination unit 19, i.e., when the predicted image shake amount l is less than the amount runout tolerance images, time tn ₁ exposure start section n ₁ was initially determined arrives (in this case, time t ₁ ), An exposure start signal is output to the above-described shutter drive unit 11, and an exposure end signal is output to the shutter drive unit 11 when the shutter time (To) has elapsed.

On the other hand, the exposure section determination unit 16 sequentially shifts the exposure start section n ₁ every time the exposure start section shift signal _Sf is input,
When the state as shown in the above equation (1) is reached, the shift operation of the exposure start section is terminated, the shutter time is shifted to a high speed side by a predetermined number of steps (in this example, 0.5 steps), and the image blur determination unit 19 is shifted. The expected image shake amount l is compared again with the allowable image shake amount, and if the predicted image shake amount l becomes smaller, the exposure start signal is output as described above, but a predetermined number of times (three times in this example) If the predicted shake amount l is larger even after repeating the shift operation, the above processing is performed in response to a new image shake speed | V _f |.

Reference numeral 17 denotes an image shake amount calculation unit as image shake amount calculation means, and as described above, the peak value | Vp | of the image shake speed | V _f | (peak values | Vp ₁ |, | Vp ₂ | and the like are collectively referred to). , The image shake amounts l _{1 to} l ₆ are predicted and calculated by the calculation formula shown in Table 1 as a function of the peak value | Vp |, and the image shake amount l of the entire exposure section in which photographing is performed. Is calculated.

Prediction image blur amount l ₁ to l ₆ for each unit section a ₁ ~a ₆ obtained as described above are stored in the memory address M ₁ ~M ₆ predicted image blur amount storage unit 18. Further, the predicted image blur amount l ₇ to l ₁₂ of each unit section a ₇ ~a ₁₂ is because it is the same value as the prediction image blur amount l ₆ to l _1, stores it in the memory address M ₇ ~M ₁₂ I do.

Further, the image blur amount calculating section 17 receives information on the exposure start section n ₁ and the exposure end section n ₂ from the exposure section determining section 16, and also stores the predicted image previously stored in the predicted image blur amount storage section 18. The corresponding data is read out of the shake amounts l _{1 to} l ₁₂ , the predicted image shake amount l of the entire exposure section is calculated by the above equation (2), and this is sent to the image shake determination unit 19.

The image blur determining unit 19 that has received the predicted image blur amount 1 of the entire exposure section, sets the allowable image blur amount (for example, a value smaller than the minimum confusion circle diameter of 35 μm) stored in the allowable image blur amount storage unit 20 in advance. Is compared with the predicted image shake amount l, and when the predicted image shake amount l is smaller than the allowable image shake amount, the exposure section determining unit 16 performs the exposure under the previously determined exposure condition.
When the predicted image shake amount l is larger, the signal is delayed by, for example, one unit section (4 ms) from the first unit section a ₁ of the initially determined (or set) quarter cycle section.
Th unit interval a ₂ of the to change to a new exposure start section n _1, and is configured to output an exposure start section shift signal S _f in the exposure section determination unit 16.

Next, the second and third inventions will be described mainly on the points different from the first invention.

Reference numeral 16 denotes an exposure section determining section as exposure section determining means. In the third and fourth inventions, first, various exposure information sections are provided.
The shutter time (To) is determined from the shutter speed information directly determined by manual input or the shutter speed information determined based on photometric information, aperture information, film sensitivity information, and the like generated in step 10 and the image is determined. shake detected image shake velocity peak value at a rate peak value detector 15 | Vp ₁ | seconds during exposure until the start time from the occurrence time point tp ₁ of calculating the number of delay intervals. Specifically, the operation of the above equation (4) is executed,
Obtaining a section n ₁ to start the exposure.

Then, when the shift signal Sf or the exposure start inhibiting signal N shutter time will be described later is not inputted, and outputs the exposure start signal When it is the time point where the exposure start interval n ₁ reaches the shutter driving unit 11 described above, At the time when the shutter time (To) set by the various exposure information section 10 or determined by calculation based on the various exposure information generated by the various exposure information section 10 elapses, the exposure end signal is transmitted to the shutter drive section 11. Is configured to be output.

Further, in the image blur amount calculation unit 17, an exposure in some cases the exposure start interval n ₁ and the exposure section determining unit 16 terminates the section n ₂
And read out the corresponding data of the predicted image shake amount l _{1 to} l _{2 in} the quarter period section previously stored in the predicted image shake amount storage unit 18 and read the predicted image shake amount l in the entire exposure section. Is calculated by the above equation (5) or (7), and this is sent to the image blur determination section 19.

The image blur determining unit 19 that has received the predicted image blur amount 1 of the entire exposure section, sets the allowable image blur amount (for example, a value smaller than the minimum confusion circle diameter of 35 μm) stored in the allowable image blur amount storage unit 20 in advance. Is compared with the predicted image shake amount l, and when the predicted image shake amount l is smaller than the allowable image shake amount, the exposure section determining unit 16 performs the exposure under the previously determined exposure condition.
However, if the predicted image shake amount l is larger, the exposure interval determination unit 16 controls the exposure section determination unit 16 to change the shutter time to a shutter speed one step faster than the initially determined (or set) shutter time To. It is configured to output the second shift signal _Sf or the exposure start prohibition signal N.

The operation of the embodiment according to the first and second aspects of the present invention will be described with reference to the flowchart shown in FIG.

First, press the release button for the first stroke
The stage switch 8 is turned on (S1).

If the user has previously set the intended shutter time by an external manual operation, the shutter time value
To is taken into the exposure section determination unit 16 together with other information obtained by the various exposure information units 10, and an aperture value for obtaining an appropriate exposure amount is determined by a predetermined calculation (S2).

Here, when the release button is pressed down to the second stroke and the second-stage switch 9 is turned on, the operation shifts to a camera shake (image shake) prediction operation. At this time, F ← 0 and ΔTv ← 0.5 are set. Here, F and ΔTv define a limit when shifting the shutter speed for an excessively large image shake. In the present invention, F = 3 times every ΔTv = 0.5 steps,
It is set so that the shutter time shift up to 1.5 stops is performed (S4).

The image shake speed calculator 14 sequentially samples the speed signals S ₁ and S ₂ output from the pair of camera shake speed detectors 5 and 6 every predetermined sampling time, and calculates the image shake speed | V _f |
_{V f | = (f / L} ) · | S 1 -S 2 | becomes arithmetic expression determined by (9) (S5).

The image shake velocity peak value detecting unit 15 receiving the image shake velocity | V _f |
The detection operation is continued until the peak value | Vp | of V _f | is detected (S6 branches to NO).

When the peak value | Vp | is detected (S6 branches to YES), the exposure section determination unit 16 sets the initial shutter time value to
Substituting into shutter times T ₁ and Tv (apex values) actually used for exposure (S7), and further calculating the number of exposure sections ΔM by an arithmetic expression of ΔM = shutter time T ₁ / unit time width (Δt). (S8).

On the other hand, the image shake amount calculation unit 17 receives the data of the peak value | Vp | of the image shake speed, and calculates each of the unit sections a ₁ of the quarter period section by the predicted image shake amount calculation formula described in Table 1 above. calculating a prediction image blur amount l ₁ to l ₆ in ~a _6, stores it in a predetermined memory address M ₁ ~M ₆ predicted image blur amount storage unit 18,
Storing with a memory address M ₇ data of the predictive image blur amount l ₆ to l ₁ to ~M ₁₂ As shown in Table 1 (S
9).

Next, the exposure section determination unit 16 determines the first exposure start section n ₁
The the unit sections a _1, an exposure completion interval n _2, (3) determined by substituting the exposure interval number ΔM to formula (S10).

After the exposure area (section) is determined, the image shake amount calculation section 17 obtains the predicted image shake amount 1 during the exposure section by the above equation (2). For example, shutter time To = 16ms
In the case of n ₁ = 1, ΔM = 4 and therefore n ₂ = 4,
The predicted image shake amount 1 at this time is Therefore, the image blur amount calculating unit 17 calculates the image blur amounts l _{1 to} l ₄ of the unit sections a _{1 to} a ₄ previously stored in the memory addresses M _{1 to} M ₄ of the predicted image blur amount storage 18. ₄ is read and the sum is calculated (S11).

The predicted image shake amount 1 calculated in this manner is compared with the allowable image shake amount read from the allowable image shake amount storage unit 20 by the image shake determination unit 19 (S12).

If the predicted image shake amount l is smaller than or equal to the allowable image shake amount, it is determined that the image shake amount accompanying the camera shake does not pose a problem as a photograph, and information to that effect is sent to the exposure section determination unit 16. Send (S12 branches to YES).

Then, the exposure section determining unit 16 (shutter time, aperture value) initially set exposure condition is opened the shutter 12 and outputs the exposure start signal at time t ₁ to the shutter driving unit 11,
Outputs an exposure completion signal to the shutter driving unit 11 at the time tn ₂ to ending exposure interval n ₂ arrives, thereby closing the shutter 12 (S1
3).

However, when the image shake determination unit 19 determines that the predicted image shake amount 1 is larger than the allowable image shake amount (when S12 branches to NO), the camera shake photographing is performed, and therefore, the exposure start section n ₁
In an appropriate interval, e.g., the exposure start interval shift signal S _f for delaying one section to output to the exposure section determination unit 16, the exposure end section determination unit 16 receiving this, first, the end of exposure interval n ₂
Is set as a unit section one section later (S14).

The image blur amount 1 in the new exposure section shifted in this way is obtained by an arithmetic expression of ₁ = lf−ln ₁ + ln ₂ (S15). Here, l _f is the predicted image blur amount of the previous, ln ₁ is the predicted image blur amount of the previous exposure start section, ln ₂ is predicted image blur amount of this exposure end section.

Then, the image blur determination unit 19 compares the predicted image blur amount 1 of the shifted exposure section an _{1 to} an ₂ with the allowable image blur amount (S16), and when the predicted image blur amount 1 is smaller (S16). S16
In the case of (YES), the exposure operation is executed as described above at the timing of the new exposure section (S13). However, if the predicted image blur amount l is still larger, the following two processes are performed. Is executed.

To (b) the exposure start section n _1, 1/2 (in this example, M = 6) cycle section number M relationship between 1/2 of the exposure interval number .DELTA.M, the above equation (1) In the case of n ₁ ≦ M− (ΔM / 2) shown above, the predicted image shake amount l can still be reduced by delaying the exposure start section n ₁ , so that the exposure start section
the n ₁ to 1 section shift (S18). This exposure start section shift operation is repeatedly performed until the predicted image blur amount 1 becomes smaller than the allowable image blur amount, and is executed until the predicted image blur amount becomes smaller (S16 is branched to YES, and the process proceeds to S13. Transition).

(B) On the other hand, if the relationship of n ₁ > M− (ΔM / 2) is satisfied in the course of the above-described exposure start section shift operation, the exposure section determination section 16 stops the exposure start section shift operation, and The shift to the shutter time shift operation is performed. (S19).

In the case of this example, in this shutter time shift operation, 0.
The image blur determination is performed while shifting to the high-speed side by 5 steps (0.5 Ev). If the predicted image blur amount 1 does not become smaller than the allowable image blur amount even after shifting three times, the shutter time shift operation is stopped. , (S21), wait for a lapse of a short waiting time (10 ms in this example) (S22), and again perform the operation of detecting the peak value | V _f | of the image blurring speed to obtain the predicted image blurring amount l. Is smaller than the allowable image shake amount, an exposure operation is performed (S13).

According to the embodiment described above, firstly, the shutter timing intended by the photographer (user) is preferentially executed, so that there is an advantage that the possibility of missing a shutter chance can be reduced.

Second, at the initially determined shutter timing,
When affected by the image blur, the shutter timing is delayed, that is, the image blur is determined while shifting in a direction slower by a predetermined time width (Δt) based on the peak value of the single image blur, and the allowable image blur amount is determined. Exposure is started at a stage where the predicted image shake amount becomes smaller, so that there is an advantage that a good photograph without image shake problem can be obtained with the shutter timing as close as possible to the photographer's intention. .

If it is determined that camera shake occurs even when the shutter timing (exposure start section) is shifted to a predetermined stage, the shutter time is sequentially shifted to the high-speed side, and the camera shake determination is performed again in the same manner. In addition, there is an advantage that a photograph without camera shake can be reliably obtained without an image shake amount exceeding a minimum circle of confusion.

In this embodiment, the semiconductor acceleration sensors 5a and 5b are used to detect the camera shake speed (acceleration directly). It is possible to

It is possible to provide sensitivity that can respond to vibrations in multiple directions.

Most suitable for detecting various vibrations occurring in irregular directions.

When manufacturing an acceleration sensor, other functional circuits such as an amplifier and a temperature compensator can be simultaneously formed on the same Si chip, so that it is suitable for mounting on a camera that requires small size and light weight.

Because it is made on the Si process, it is cheaper and suitable for mass-produced products such as cameras.

This is because there are various advantages such as:

It should be noted that the present invention is not limited to the embodiment described above and shown in the drawings, and various modifications can be made without departing from the scope of the invention.

For example, although not shown in the flowchart of FIG. 4, when it is determined in steps S12 and S16 that the predicted image shake amount l is larger than the allowable image shake amount, the alarm unit
For 13, giving information such as that the camera shake determination has been made, that the exposure start section shift operation is being performed or the shift operation at the time of the shutter is in progress, or that shutter activation has been blocked due to the risk of camera shake, A display corresponding to the information may be performed by the alarm unit 13 by sound or light.

Further, in the illustrated example, the frequency of the modeled simple vibration is 10 Hz, and the predetermined time width Δt is 4 ms, but this is not strictly defined as 10 Hz and 4 ms, but in relation to the effect brought by the present invention. The permissible range is determined, and it is a matter of course that the permissible range is included in the present invention within the permissible range.

Appropriate means other than those shown in the figures may be used as the means for detecting the peak value of the image blur speed and the point of occurrence thereof, and the means for calculating the predicted image blur speed in the first six unit sections.

Also, the exposure start time for setting the exposure section need not be set to the first unit section as in the embodiment,
In short, it can be changed appropriately as long as it does not depart from the gist of the present invention.

Next, the operation of the second and third embodiments of the present invention will be described with reference to FIG.
This will be described with reference to the flowchart shown in FIG.

First, press the release button for the first stroke
The stage switch 8 is turned on (S1).

If the user has previously set the intended shutter time by an external manual operation, the shutter time value
To is taken into the exposure section determination unit 16 together with other information obtained by the various exposure information units 10, and an aperture value for obtaining an appropriate exposure amount is determined by a predetermined calculation (S2).

Here, when the release button is pressed down to the second stroke and the second-stage switch 9 is turned on, the image shake speed calculating unit 14 sets the pair of camera shake speed detectors 5 and 5 at predetermined sampling times.
Speed signal S ₁ output from 6, S ₂ successively samples the image blur velocity | V _f | a _{| V f | = (f /} L) · | S 1 -S 2 |
(S4).

The image shake velocity peak value detecting unit 15 receiving the image shake velocity | V _f |
The detection operation is continued until the peak value | Vp | of V _f | is detected. When the peak value | Vp | is detected (S5 branches to YES), the data of the peak value | Vp |
16 are input to, wherein, the prediction image blur amount l ₁ to l ₆ for each unit section l ₁ to l ₆ 1/4 cycle section by the prediction image blur value calculation formula described in Table 1, calculated, This is the predicted image blur amount storage
18 stored in a predetermined memory address M ₁ ~M ₆ of (S6).

Then, the exposure period determination section 16, a shutter time value T _1, set the initial shutter speed value the To (S7), the exposure interval number .DELTA.M .DELTA.M = calculation formula To / unit time width becomes the shutter time Then, the number of exposure sections ΔM is substituted into the above equation (4), n ₁ = M−ΔM + 1, to determine an exposure start section n ₁ (S 9).

Then, the exposure start interval n ₁ is greater than zero (n _1>
0) In the case (branch to S10 to NO), the image blur amount calculating unit 17
The predicted image shake amount 1 during the exposure section is obtained by the above equation (5) (for example, when the shutter time To = 16 ms, Δ
M = 4, n ₁ = 3, and the predicted image shake amount 1 at this time is 1 = l ₃ + l ₄ + l ₅ + l ₆ . (S11).

On the other hand, in the exposure section determination unit 16, the exposure start interval n _1, n ₁
If ≦ 0, the exposure start section n ₁ is set as n ₁ = 1, and the exposure end section n ₂ is obtained by the above equation (S12).

Then, in the image shake amount calculation unit 17, based on the n ₁ and n _2, performs arithmetic processing of equation (7) (S13).

The predicted image blur amount 1 thus calculated is compared with the allowable image blur amount read from the allowable image blur amount storage unit 20 by the image blur determination unit 19 (S14).

If the predicted image shake amount 1 is smaller than the allowable image shake amount, it is determined that the image shake amount accompanying the camera shake does not pose a problem as a photograph, and information to that effect is sent to the exposure section determination unit 16 ( S14 branches to NO).

Then, the exposure section determining unit 16 outputs an exposure start signal to the shutter driving unit 11 at time tn ₁ under the initially set exposure conditions (shutter time, aperture value) to open the shutter 12, and causes image blur. outputs an exposure completion signal to the shutter driving unit 11 at the time t ₇ as a zero velocity, thereby closing the shutter 12 (S1
Five).

However, when the image shake determination unit 19 determines that the predicted image shake amount l is larger than the allowable image shake amount (when S14 branches to YES), the camera shake shooting is performed. A shutter time shift signal for shifting by one stage is output to the exposure section determination unit 16, and upon receiving the signal, the exposure time determination unit 16 reduces the shutter time by half (S16).

Then, the flowchart returns to the calculation processing step (S8) of the number of exposure sections ΔM again, and repeats the subsequent steps until the predicted image shake amount 1 becomes smaller than the allowable image shake amount.

When the image shake determining unit 19 determines that the predicted image shake amount l is larger than the allowable image shake amount as in the above-described embodiment, instead of configuring to shift the shutter time, an exposure start prohibition signal is used. May be given to the exposure section determining unit 16 to prohibit exposure (S17). In this case, the flowchart returns to the processing procedure (S4) of the detection operation of the image blur speed | V _f |, and executes the subsequent processing procedures. If the predicted image blur amount 1 becomes smaller than the allowable image blur amount, the exposure operation is performed. Is performed (S15).

As described above, according to the embodiment described with reference to FIG. 5, the shutter time intended by the user, or
Exposure using the shutter time that is the closest to that can be reliably and automatically performed within a time range that falls within the camera shake allowable range, and while respecting the user's intention,
The camera shake phenomenon on the film surface can be effectively and appropriately suppressed.

That is, regarding the exposure timing, the number of exposure sections Δ
When M is smaller than the quarter period section number M, the exposure is performed so that the end time of the exposure becomes the time when the image shake velocity | V _f | = 0 in the modeled simple oscillation. Photographing is performed in a time domain (section) that is as small as possible. Therefore, there is an advantage that the possibility that the image blur amount on the film surface at the time of exposure can be photographed within the range of the allowable image blur amount increases.

If it is determined that camera shake occurs at the initially set (or selected) shutter time, the shutter time is sequentially shifted to the high-speed side, and the camera shake determination is performed again in the same manner. There is an advantage that a photograph without camera shake can be reliably obtained without the amount exceeding the minimum circle of confusion.

Further, according to the modified embodiment, when the predicted image blur amount is larger than the allowable image blur amount, the operation is performed to prohibit the exposure, and the exposure is allowed only when the camera shake is reduced. In this case, no camera shake is caused.

It should be noted that the second and third inventions are not limited to the embodiment described above and shown in the drawings, and various modifications can be made without departing from the scope of the invention.

For example, although not shown in the flowchart of FIG. 5, when it is determined in step S14 that the predicted image shake amount 1 is larger than the allowable image shake amount, the camera shake judgment is made to the alarm unit 13; Alternatively, information such as that the shift operation is being performed at the time of the shutter time, or that the shutter has been activated due to the risk of camera shake is given, and a display corresponding to the information is given by sound or light at the alarm unit 13. You may make it perform.

Further, it is not necessary to set the exposure start time for setting the exposure section to a time other than the illustrated example, and it is not necessary to exactly match the 0 value time point of the image shake speed with the exposure end section.
In short, it can be changed appropriately as long as it does not deviate from the gist of the present invention.

Further, regarding the time width Δt of each unit section a _{1 to} a ₁₂ ,
It is preferable to set the time as short as possible, but the time widths need not necessarily be uniform. For example, with respect to a unit section located near the time point at which the image blurring speed is 0, the time width can be set longer than the time widths of other unit sections.

Next, based on one specific example shown in FIG. 6 to FIG.
Embodiments of a camera having a camera shake prevention function according to the inventions related to the third invention will be described.

The acceleration sensor (camera shake speed detector) used in the present invention is the same as that shown in FIG. 2, and therefore the description of the configuration, operation, and the like is omitted. Further, since the embodiment of the present invention is common to the embodiment shown in FIGS. 1 to 4 in many parts, redundant description will be avoided as much as possible, and different parts will be mainly described. .

In FIG. 6, the description of the reference numerals 1 to 15 is omitted.

An exposure control unit 16a is generated by the various exposure information units 10. The shutter time (T) is determined from shutter speed information directly set by manual input or shutter speed information determined based on photometric information, aperture information, film sensitivity information, and the like, and an image shake speed peak value detection unit. A delay time of (25−T / 2) [ms] is calculated from the generation point (tp) of the peak value | Vp | of the image blur speed detected in 15. And
When the delay time (25−T / 2) [ms] has elapsed, an exposure start signal is output to the above-described shutter drive unit 11 and is set by the various exposure information units 10 or the various exposure information units 10
Is configured to output an exposure end signal to the shutter drive unit 11 when a shutter time (T) determined by calculation based on the various pieces of exposure information generated in step (1) elapses.

Reference numeral 17a denotes an allowable image shake speed storage unit in which the allowable image shake speed Vs determined according to the shutter time is set (stored) in advance as described above.

Reference numeral 18a denotes an image blur determination unit which receives an image blur speed peak value | Vp | and a shutter speed (T) signal from the exposure control unit 16a, and generates an allowable image blur signal Vs corresponding to the shutter time (T). The image blur speed is read from the allowable image blur speed storage unit 17a and compared with the sequentially input image shake speed peak value | Vp | based on the allowable image shake speed | Vs |, and the image blur speed peak value | Vp |
Is larger than the permissible image shake speed Vs, the exposure start permission signal is not sent to the exposure controller 16a.

The operation of the illustrated embodiment configured as described above will be described with reference to the flowchart shown in FIG.

First, press the release button for the first stroke
The step switch 8 is turned on (S10). Assuming that the user has previously set an intended shutter time by an external manual operation, the shutter time value To is set to the exposure control unit 16a.
Then, the exposure value is fetched together with other exposure information obtained by the various exposure information units 10, and the aperture value is determined by a predetermined calculation so that an appropriate exposure amount is obtained (S11).

Next, in the exposure control unit 16a, the set shutter time T
It is determined whether or not o is 40 ms or more, and if it is 40 ms or more, a camera shake warning signal is output (S12).

Upon receiving the camera shake warning signal, the warning unit 13 issues a warning using a light emitting element or a sound emitting element (S13), and performs a camera shake handling process such as disabling the operation of the second-stage switch 9 or locking the release button. (S14).

On the other hand, if the set shutter time To is less than 40 ms,
"To>40ms?" Branches to NO (S12).

Here, when the release button is pressed down to the second stroke and the second-stage switch 9 is turned on, the image shake speed calculation unit 14
At predetermined sampling times (t), the speed signals S ₁ and S ₂ output from the pair of camera shake speed detectors 5 and 6 are sampled sequentially, and the image shake speed | V _f | = (f / L) · The arithmetic processing is performed by the arithmetic expression | S ₁ −S ₂ | (S 16). The image shake speed peak value detection unit 15 receiving the image shake speed | V _f | signal sequentially calculated in this manner is a peak value of the image shake speed | V _f |
The detection operation is continued until | Vp | is detected. Then, when the peak value | Vp | is detected (S17 branches to YES), the image shake determining unit 18a calculates the allowable image shake speed Vs corresponding to the shutter time To from the allowable image shake speed storage unit 17a. Read out, compare the magnitude relationship with the image shake velocity peak value | Vp |, and | Vp |> Vs
If | Vp |> allowable run-out speed Vs? Is branched to YES (S18), and returns to | _Vf | detection again (S16), | Vp | <
If it is Vs, the process branches to NO, and the exposure control unit 16a sets (25−T
o / 2) A delay time (or a standby time) is calculated by an arithmetic expression of [ms], and an exposure start signal is obtained at a time point ts after the delay time elapses from the time point tp when the peak value | Vp | of the image blurring speed is detected. Is output to the shutter drive unit 11. (S20). Then
The shutter drive unit 11 drives the shutter 12 to open, and exposure is started (S21).

Subsequently, the image blur speed | V _f | is detected (S21),
Although illustration is omitted, the image shake amount calculation means calculates the exposure start time.
The image shake velocity | V _f | is sampled at a constant sampling time t from ts to the end of exposure, and the total of the product of the image shake velocity | V _f | The image blur amount 1 is obtained from the sum during the exposure time (T) (S22).

That is, the operation of l = Σ | V _f | × t is executed. When it is confirmed that the exposure is completed (S23), the image shake amount 1 is calculated, and the actually generated image shake amount 1 and the allowable image shake amount lm determined by the shutter time (T) are calculated. If l> lm is compared by a shake amount determining means (not shown), a not-illustrated image is taken to notify that the photographed image that has just been photographed has exceeded an allowable limit. The notification means is driven (S25).

If l <lm, it means that the image blur has not substantially occurred or has stayed within an allowable range.
All shooting operations are completed (S26).

According to the present embodiment configured and operated as described above, the transition of the image shake speed | V _f | caused by the camera shake is defined as a modeled single vibration of approximately 10 Hz, and the shutter time set in the camera is set. If the time T is T <40 ms, the image blur velocity | V _f | changing according to the modeled simple vibration is searched, and its peak value | Vp | and its occurrence time point tp are detected. The value | Vp | is compared with the permissible image shake velocity value Vs specific to the currently set shutter time To, and, on the other hand, the shutter time The image shake speed | V _f | in the exposure time zone by setting the central time point of the exposure time zone
Is controlled to be a small value, thereby automatically setting the image shake speed on the film surface during exposure to within an allowable image shake range. A camera having a camera shake prevention function rich in image quality can be obtained.

In addition, since the warning unit 13 or a camera shake notifying unit (not shown) is provided, the user can be notified that the shutter time T needs to be changed, and the user's intention can be reflected even a little.

The present invention is not limited to the shutter-priority type, but can be naturally applied to an aperture-priority type, a program type, a manual setting type, and the like.

〔The invention's effect〕

As described above in detail, according to the camera having the camera shake preventing function according to the first invention, the exposure start section is set to 1/4
If the predicted image shake amount does not become smaller than the allowable image shake even after shifting to a predetermined unit section in the cycle section, the image shift is shifted in a direction to shorten the shutter time, and the image shake determination is performed to determine the allowable image shake amount. Since the exposure operation is performed under a smaller condition, it is possible to take a photograph as close as possible to the shutter time intended by the photographer as long as the image shake amount does not matter.

According to the second and third aspects of the present invention, the exposure section is adjusted from the beginning to a region having a relatively low image shake speed among simple vibrations having a frequency of about 10 Hz, which is the largest cause of image shake due to camera shake. If the predicted image shake amount is determined to be larger than the allowable image shake amount in the event that the image shake amount is predicted before photographing, the shutter time is shifted to a higher speed side, or the exposure is started. Camera that can be activated in a shorter time while respecting the user's intention, despite a simple configuration, and that can effectively and appropriately prevent camera shake shooting beforehand. Can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the overall configuration of a common embodiment of a camera having a camera shake prevention function according to the first to third inventions, and FIG. 2 is a diagram common to the first to third inventions. In the example,
FIG. 1 is a layout explanatory view showing the layout of a pair of acceleration sensors in FIG. 1, FIG. 3 is a principle explanatory view for explaining the operating principle of the first to third inventions, and FIG. FIG. 5 is a flowchart for explaining an operation order of the camera having the camera shake prevention function; FIG. 5 is a flowchart for explaining an operation order of the camera having the camera shake prevention function according to the second and third inventions; FIG. 6 is a block diagram showing the overall structure of an embodiment of a camera having a camera shake preventing function according to the present invention, and FIG. 7 is a principle explanation for explaining the operation principle of the camera. FIG. 8 is a flowchart for explaining the operation sequence. 1 camera body, 2 photographic lens, 3 photographic optical axis in normal condition, 3 'photographic optical axis in tilt, 4 film surface, 5, 6 pair of camera shake speed detector , 5a, 6a ... acceleration sensor, 5b, 6b ... acceleration integrator, 7 ... general control unit CP
U), S ₁ , S ₂ ... speed signal, 8 ... first-stage switch, 9
... Second stage switch, 10 Various exposure information sections, 11 Shutter drive section, 12 Shutter, 13 Alarm section, 14
Image shake speed calculation unit, 15: Image shake speed peak value detection unit,
16 ... Exposure interval determination unit, 16a ... Exposure control unit, 17 ... Image shake amount calculation unit, 17a ... Allowable image shake speed storage unit, 18 ...
Predicted image shake amount storage unit, 18a: image shake determination unit, 19: image shake determination unit, 20: allowable image shake amount storage unit, | V _f |: image shake speed (predicted image shake speed).

Claims (3)

(57) [Claims] An image shake speed calculating means for calculating an image shake speed on a film surface based on camera shake speed information obtained from a camera shake speed detecting means provided in a camera, and a shutter provided by the image shake speed calculating means. A peak value of the image blur speed output when the release button is pressed down to the second stroke and an image blur speed peak value detecting means for detecting a point of occurrence of the peak value, and manual input or photometric information, aperture information,
The shutter time is determined based on the input of the film sensitivity information and the like, and at least a quarter period section from the time when the image shake velocity peak value related to the modeling simple vibration having a frequency of approximately 10 Hz to the time when the image shake velocity is 0 is obtained Is divided in time series with a predetermined time width, a plurality of unit sections are set in advance, and the exposure time is divided into a plurality of unit sections by dividing the shutter time by the predetermined time width. A predetermined unit section close to the image shake velocity peak value and within the 1/4 cycle section is set as an initial exposure start section, an exposure start signal is output in this exposure start section, and the exposure start signal is output from this exposure start signal output time. At the time when the shutter time has elapsed, an exposure end signal is output. On the other hand, when an exposure start section shift signal is received, the exposure start section is appropriately changed in a direction to be delayed, and an exposure start section shift signal is sent from the image blur determination means. Receiving If the predicted image shake amount does not become smaller than the allowable image shake amount even if the predicted image shake amount is shifted to a predetermined unit period within the 1/4 cycle section, at least an exposure section determination unit that changes the shutter time to a shorter time, 1/4
Image shake amount calculating means for calculating a predicted image shake amount of each unit section belonging to a periodic section as a function of the peak value of the image shake speed, and calculating a predicted image shake amount of the entire exposure section; Image blur determining means for outputting the exposure start section shift signal to the exposure section determining means when a predicted image shake amount of the entire exposure section obtained by the amount calculating means is larger than a preset allowable image shake amount. And a shutter driving means for opening a shutter in response to the exposure start signal from the exposure section determining means and closing the shutter in response to the exposure end signal. With a camera. 2. An image shake speed calculator for calculating an image shake speed on a film surface based on camera shake speed information obtained from a camera shake speed detector provided in the camera, and an image shake speed calculator. Image shake speed peak value output when the shutter release button is depressed to the second stroke and image shake speed peak value detection means for detecting the point of occurrence of the peak value, and manual input or photometric information, aperture information, film sensitivity The shutter time is determined based on input of information and the like, the shutter time is divided by a predetermined time width to calculate the number of exposure sections, and the peak value of the image vibration speed of the image vibration single vibration having a frequency of approximately 10 Hz. The section from the occurrence of the image blur velocity to the point of the image blur velocity 0 value is divided by the predetermined time width to determine the image blur of the exposure section from the relationship between the preset number of quarter period sections and the number of exposure sections. Speed An exposure start section is calculated so as to enter a region having a slower degree, an exposure start signal is output in this exposure start section, and an exposure end signal is output when the shutter time has elapsed from the output of the exposure start signal. On the other hand, when a shutter time shift signal is received, an exposure section determining means for changing the shutter time in the direction of shortening the shutter time and performing each of the processes, and a predicted image shake amount of each unit section belonging to at least the quarter cycle section Is calculated as a function of the peak value of the image blur speed, and the image blur amount calculating means for calculating the predicted image blur amount of the entire exposure section, and the entirety of the exposure section obtained by the image blur amount calculating means. When the predicted image shake amount is larger than a preset allowable image shake amount, an image shake determination unit that outputs the shutter time shift signal to the exposure period determination unit, and the exposure period determination unit Opening the shutter by receiving a start signal, with the shutter driving means for closing said shutter by receiving an exposure end signal, the shaking motion picture-taking preventing function characterized by comprising comprises a city camera. 3. The image blur determining means compares the predicted image blur amount of the entire exposure section with the allowable image blur amount stored in advance in an allowable image blur amount storage unit. 3. The camera with a camera shake prevention function according to claim 2, wherein an exposure start prohibition signal is output to the exposure section determination means when the distance is large.