JPH086087A - Controller for preventing image shake - Google Patents

Abstract

PURPOSE:To prevent a deterioration in an image caused by the fact that the influence of aberration becomes great because a focal distance is made long by providing a control means for making the actuating range of an image shake preventing means small. CONSTITUTION:The control means for making the actuating range of the image shake preventing means for preventing the shake of the image due to movement in an optical path because the focal length is made long is provided to prevent the influence of the aberration on the image from being too great. In other words, a focal length sensor 1 detects the position of the variator lens of a zoom lens 52 or the like. Moreover, maximum shake angle data 2 is stored in a microcomputer 46 as a table corresponding to the focal length. Then, the information of the focal length is fetched in the microcomputer 46 for controlling a variable apex angle to prevent the shake and the maximum shake angle in use of a variable apex angle prism 41 used is regulated from the result of the detection.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an image blur prevention device used in cameras, video cameras, other optical devices and the like.

[0002]

2. Description of the Related Art In the field of camera devices such as video cameras and still cameras, size and weight reductions have been remarkable in recent years.
At the same time, high functionality is being measured. As one of the higher functions, there is a higher magnification of a photographing lens, and a zoom lens having a magnification of 10 times or 12 times has become popular in the field of home cameras.

However, as the focal length on the long focal length side becomes a large value with the increase of the zoom ratio, the influence on the recorded image becomes large, and a moving image such as a video camera does. In the above, the main subject moves unsightly on the screen, and in a still image, a shake image is recorded. Also,
For still images, even if it is possible to avoid the problem to some extent by increasing the shutter speed, in moving image recording, since the recording is primarily on the time axis, the effect of camera shake is It cannot be avoided. Under such circumstances, mainly in the field of video cameras, a shake prevention device that removes the influence of camera shake has been put into practical use.

This shake prevention apparatus includes at least shake detecting means for detecting a shake component and shake correcting means for correcting shake according to the detection result of this detecting means. Among these, as the shake detection means, a so-called electronic detection method for comparing images between two consecutive screens, an angular velocity meter,
There is a method of directly measuring the actual movement of the camera using an angular accelerometer or the like.

Further, as the shake correction means, in addition to a so-called electronic correction method of electronically selecting a range (cutout range) to be actually recorded from the obtained image, an optical axis of the photographing optical axis is used. There is an optical shake correction unit that adjusts the angle of 1 to the direction in which the shake is removed.

Of the optical shake correction means, particularly the method using a variable apex angle prism will be described with reference to FIGS.
Will be described below.

FIG. 19 shows the structure of a variable apex angle prism.
In FIGS. 19A, 19B, and 19C, 21 and 23 are glass plates, and 27 is a bellows portion made of a material such as polyethylene. Inside the glass plate and the bellows, a transparent liquid such as silicon oil is sealed.

In FIG. 19 (B), two glass plates 21 and 2 are used.
3 is a parallel state, and in this case, the incident angle and the outgoing angle of the light beam of the variable apex angle prism are equal. On the other hand, (A),
When there is an angle as shown in FIG.
The rays are bent at an angle as indicated at 26.

Therefore, when the camera is tilted due to camera shake or the like, the spectral line corresponding to the angle is bent,
The blur can be eliminated by controlling the angle of the variable apex angle prism provided in front of the lens.

FIG. 20 shows this state.
Assuming that the variable apex angle prism is in a parallel state in (A) and the optical axis captures the center of the subject, a variable apex angle as shown in FIG. By driving the prism to bend the light beam, the shooting optical axis remains the same, and you can continue to capture the center of the subject.

FIG. 21 is a diagram showing an actual configuration example of a variable vertical angle prism unit including the variable vertical angle prism, an actuator section for driving the variable vertical angle prism, and a vertical angle sensor for detecting an angular state.

Since actual blurring appears in all directions, the front glass surface and the rear glass surface of the variable apex angle prism are configured so as to be rotatable about axes that are offset by 90 degrees. Here, the subscripts a and b indicate the respective components in these two rotation directions, but those having the same number have exactly the same function. Also b
Some of the parts on the side are not shown.

Reference numeral 41 denotes a main body of the variable apex angle prism, which is composed of glass plates 21 and 23, a bellows portion 27 and an internal liquid. The glass plate is integrally attached to the holding frame 28 using an adhesive or the like. The holding frame 28 constitutes a rotary shaft 33 with a fixed component (not shown), and is rotatable around this shaft. The shaft 33a and the shaft 33b are different in 90 ° direction. A coil 35 is integrally provided on the holding frame 28, while a magnet 36,
Yokes 37 and 38 are provided. Therefore, the variable apex angle prism is rotated around the axis 33 by passing a current through the coil. Arm part 3 extending integrally from the holding frame 28
There is a slit 29 at the tip of 0, and a vertical angle sensor is configured between a light emitting element 31 such as an iRED element and the like, which is provided in a fixed portion, and a light receiving element such as a PSD.

FIG. 22 is a block diagram showing the configuration of a vibration-proof lens system in which a shake prevention device equipped with this variable apex angle prism as shake correction means is combined with a lens.

In FIG. 15, 41 is a variable apex angle prism,
Reference numerals 43 and 44 are apex angle sensors, 53 and 54 are detection circuit units for amplifying the outputs of the apex angle sensors, 45 is a microcomputer, and 46 and 47 are blurring detecting means such as angular accelerometers.
Reference numerals 48 and 49 are actuators including the coil 35 to the yoke 38 and the like, and 52 is a lens.

In the microcomputer 45, the variable apex angle prism is set to the optimum angle state for removing the blur according to the angle state detected by the apex angle sensors 43 and 44 and the detection result of the blur detecting means 46 and 47. In order to control, the electric current which energizes the actuators 48 and 49 is determined.

The main element is made up of two blocks because it is assumed that control in two directions 90 degrees apart is performed independently.

FIG. 23 is a diagram showing a more detailed structure of a conventional variable apex angle prism. In FIG. 23, 21, 2
3 is a glass plate, 22 is a liquid sealed inside, 27 is a bellows portion, and 25 is an optical axis. Further, 59 to 62 are films made up of four donut-shaped parts for forming the bellows portion 27, and 57 is a joint between the films,
Reference numeral 58 represents a connecting portion between the film and the frame. Also, the frame body 55
And the frame core member 56.

Of these, the joint portion 57 between the films is joined by welding. Therefore, it is desirable that the materials of the films 59 to 62 have excellent heat-sealing properties at least on both surface layers, and for example, polyethylene (PE), polypropylene (PP) or the like is generally used.
Further, the frame 55 and the glass plate 21 or 23 are fixed by using an adhesive, but when the frame 58 and the joint portion 58 of the films 59 and 62 forming the bellows are welded like the joint portion 57, , It must be the same material as the surface of the film. However, the above-mentioned materials having excellent heat-sealing properties have drawbacks in that it is difficult to obtain component accuracy as compared with so-called polycarbonate (PC), which is often used around such a lens barrel, and has low rigidity and is easily deformed. have. Therefore, 56 is a frame core material provided to avoid this problem. The frame core material 56 is the frame 5
5 is made of a metal having a higher rigidity and a higher heat deformation temperature than the material of No. 5, or a metal such as aluminum or stainless steel. Based on this frame core material 56, for example, by insert molding, the periphery of the frame core material 56 is formed. The frame 55 is formed. As a result, the flatness of the portion of the frame 55 to which the film is welded, the strength or dimensional accuracy of the body-attached portions of the glass plates 21 and 23, or the dimensional accuracy of the fitting diameter of the glass can be obtained.

The configuration in which the variable apex angle prism is used as the optical shake correction means has been described above.

Next, as another example of the optical shake correcting means, a method of movably disposing a correcting optical system as disclosed in USP 2959088 will be described.

FIG. 24 shows the overall structure.

In FIG. 24, lenses 71 and 72 are correction optical systems with respect to main lenses 82 and 83. The focal lengths of the correction optical system are set as follows. Lens barrel 7
If the focal length of the lens 71 having a negative power fixed to 4 is f ₁ and the focal length of the lens 72 having a positive power supported by the movable support portion 73 is f ₂ , then f ₁ = −f The focal length of each lens is set so as to satisfy the relationship of ₂ .

Further, a lens 72 is supported by a gimbal 5 for supporting biaxial movement.

In order to balance the correction optical system,
A counterweight 80 is provided.

By satisfying such optical conditions, it is possible to realize a shake preventing device including a so-called inertial pendulum type optical shake correcting means.

Next, a description of the biaxial movement of the gimbal 75 will be given with reference to FIG.

The lens 72 is supported by a supporting member 75y having a degree of freedom in the y-axis direction, and the supporting member 75y has a supporting member 75x having a degree of freedom in the x-axis direction perpendicular to the y-axis direction.
And the supporting member 75x is supported by the lens barrel 74.

With such a configuration, a correction optical system having biaxial degrees of freedom can be constructed.

Next, a typical example of a zoom lens when the shake correcting means having the variable apex angle prism described above is combined with a zoom lens will be shown. Here, a so-called inner focus or rear focus zoom lens in which focusing is performed by a lens group behind the variator lens group for zooming will be described.

Although various lens types like this are known, FIG. 26 shows an example in which the rearmost lens group is used for focusing. In the figure, 1
Reference numeral 11 is a fixed front lens group, 112 is a variator lens group, 113 is a fixed lens group, and 114 is a focusing (compensator) lens group. 133 is a guide rod for rotation prevention, 134 is a variator feed rod, 135 is a fixed lens barrel, 136 is an aperture unit (here, inserted at right angles to the paper surface), 137 is a step motor, which is a focus motor, and 138 is A male thread for moving the lens on the output shaft of the step motor is applied.
Reference numeral 139 denotes a female screw portion that meshes with this male screw, and the lens 4
It is integrated with the moving frame 140. Reference numerals 141 and 142 are guide rods for the moving frame of the lens 4, 143 is a rear plate for positioning and pressing the guide rods, and 144 is a relay holder. 145 is a zoom motor, 146 is a reducer unit 147 of the zoom motor, 148 is an interlocking gear, and 148 is a gear fixed to the zoom feed rod 134.

With the above configuration, the step motor 137
When is driven, the focus lens 4 moves in the optical axis direction by screw feeding. When the zoom motor 145 is driven, the gears 147 and 148 are interlocked with each other and the shaft 134 is rotated, so that the variator 2 is moved in the optical axis direction.

FIG. 27 shows the positional relationship between the variator lens and the focusing lens in such a lens according to some distances. Here, as an example,
The in-focus positional relationship for each subject of infinity, 2 m, 1 m, 80 cm, and 0 cm is shown. In the case of inner focus,
As described above, since the positional relationship between the variator and the focus lens varies depending on the subject distance, it is impossible to interlock the lens groups with a simple mechanical structure like the cam ring of the front focus lens.

Therefore, if the zoom motor 145 is simply driven under the structure shown in FIG. 26, defocusing will occur.

Since the inner focus lens has the above-described characteristics, the inner focus lens has "excellent close-up shooting ability" as compared with the front lens focus lens.
Despite the advantages such as "the number of lens elements is small", its practical application was delayed.

However, in recent years, a technique for optimally controlling the lens positional relationship as shown in FIG. 27 in accordance with the subject distance is being developed and commercialized.

For example, the same applicant of the present case (proposal N
o. 1,208,037) (Ibid. 1,262,117)
(Id. 1,265,003) presents a method of tracing a trajectory of the positional relationship between both lenses according to such a distance.

In the Japanese Patent Application Laid-Open No. 1-280709 filed by the present applicant, the positional relationship between the variator and the compensator (focus lens) is maintained by the method shown in FIGS.

FIG. 28 shows a block diagram. 111 ~
Reference numeral 114 denotes the same lens group as that shown in FIG. The position of the variator lens group 2 is detected by the zoom encoder 149. Here, as the type of encoder, for example, a brush integrally attached to a variator moving ring is configured to slide on a substrate on which a resistance pattern is printed. It is possible to use a volume encoder. Reference numeral 150 denotes a diaphragm encoder for detecting the diaphragm value, which uses a Hall element output provided in a diaphragm meter, for example. 151 is CC
An image pickup device such as D, 152 is a camera processing circuit, and the Y signal is taken into the AF circuit 153. The AF circuit determines whether it is in-focus or out-of-focus, and when it is out of focus, it is determined whether it is the front focus or the rear focus, and the degree of non-focus. These results are fetched by the CPU 154.

A power-on reset circuit 155 performs various reset operations when the power is turned on. A zoom operation circuit 156 notifies the CPU 154 of the contents when the operator operates the zoom switch 157. 158-1
Reference numeral 60 is a memory portion for the locus data shown in FIG. 19, and includes direction data 158, speed data 159, and boundary data 160.
Consists of 161 is a zoom motor driver, 162 is a step motor driver, and the number of input pulses of the step motor is continuously counted in the CPU and is used as an encoder of the absolute position of the focus lens. In such a configuration, the variator position and the focus lens position are determined by the zoom encoder 149 and the step motor input pulse number, respectively, so that one point on the map shown in FIG. 27 is determined. On the other hand, the map shown in FIG. 27 is divided by the boundary data 160 into tanzaque small areas as shown in FIG. Here, the shaded area is an area where the lens is prohibited. When a point on the map is determined in this way, it is possible to determine the area of the small area to which the point belongs.

For the speed data and direction data, the rotation speed and direction of the step motor obtained from the locus passing through the center of each area are stored in each area.
For example, in the example of FIG. 29, the horizontal axis is divided into 10 zones. Now assuming that the zoom time is 10 seconds,
The passing time of one zone is naturally 1 second. When an enlarged view of the block III in FIG. 29 is shown in FIG. 30, a locus 164 passes through the center of the block, a locus 165 at the lower left, and a 166 at the upper right. Here, the center locus is xmm /
If you move at a speed of sec, you can trace the trajectory with almost no error.

The speed thus obtained is called the area representative speed, and the speed memory stores as many values as the number of small areas according to each area. Also, set this speed to 1
Indicated as 68, the representative speed is finely adjusted to 167 and 169 according to the detection result of the automatic focusing device to set the step motor speed. In the direction data, the rotation direction of the step motor changes depending on the area even in the same tele-to-wide (wide-to-tele) zoom, so this code is stored.

With respect to the area representative speed obtained from the variator and the focus lens position as described above, the step motor speed determined by correcting this speed is further used by the detection result of the automatic focus detection circuit to drive the zoom. By driving the step motor to control the focus lens position, even with the inner focus lens, it is possible to prevent defocusing during zooming.

Here, in addition to the representative speed of 168 in FIG. 30, speeds such as 167 and 169 are stored for each block and one of three speeds is selected according to the detection result of the automatic focus detection device. A method of selecting the speed is also proposed in Japanese Patent Laid-Open No. 2-173605 by the present applicant.

In addition to the method of storing such speeds, some curves such as ∞, 2m, and 1m shown in FIG. 27 are stored as a memory of focus lens positions corresponding to a plurality of variator positions. Incidentally, there is also known a method of internally calculating the positional relationship between the two lens groups to be taken from the data of the upper and lower stored curves when the distance is the middle of the stored curves.

FIG. 31 shows an example of the construction in the case where the shake correcting means using this zoom lens and a variable apex angle prism is connected to the above-mentioned zoom lens.

In FIG. 31, reference numeral 263 is a rotary shaft portion integrally provided with the holding frame 28, and 267 is a rotary shaft opposite to the rotary shaft 263. It is configured by thickly inserting the metal shaft, etc., into the holding frame. 268 is a leaf spring, 269 is a screw for fixing the leaf spring, 266 is a flat glass, and is provided to prevent the photographer or the like from directly touching the variable apex angle prism and damaging it. 265 is an accessory mounting screw, 26
Reference numeral 4 denotes a fixed barrel member including a hole for a rotary bearing of the variable apex angle prism.

The lens barrel part 264 is fastened to the fixed lens barrel 135 of the zoom lens by the screw 270.

Note that, in FIG. 31, for simplicity, components such as a holding frame for rotating the glass on the front side of the variable apex angle prism, an actuator, and a sensor unit for detecting the apex angle are not shown.

[0050]

However, when the above-mentioned optical shake correcting means such as a variable apex angle prism or a movable correction optical system is used, the correction angle is particularly large, or In situations such as when the combined focal length of the zoom lenses is large, or when electronic zooming is used to enlarge and record a part of the screen, color shift due to the effect of chromatic aberration that occurs in principle by bending the optical axis may occur. There is a concern that it will stand out.

In the past, this problem was suppressed to a level below the problem level, but in the future, the image quality tends to improve as the number of pixels of the CCD, which is an image sensor, improves. The level of chromatic aberration that has not been a problem in the past when considering the background such as the enlargement function (so-called electronic zoom) tends to be generalized and the fact that cameras with improved image quality such as 3CCD cameras are emerging. However, there is a possibility that it will contribute to the deterioration of image quality in the future.

(Object of the Invention) The first object of the present invention is to control for image blur prevention which can prevent the influence of aberration from becoming large and the image being deteriorated due to the increase of the focal length. It is intended to provide a device.

A second object of the present invention is to prevent image blurring which can prevent the occurrence of aberration and deterioration of the image when the contrast of the object to be imaged is high. It is intended to provide a control device.

A third object of the present invention is to provide a control device for preventing image blur, which can prevent the influence of aberration from becoming conspicuous due to the resolution of the image for which image blur is prevented. It is a thing.

A fourth object of the present invention is to provide a control device for preventing image blur, which can prevent an image from being conspicuously affected by aberrations due to the electrical processing state of the image which has been prevented from image blur. Is to provide.

[0056]

In order to achieve the first object of the present invention, the present invention as set forth in claims 1 to 4 is realized by moving in the optical path according to the increase of the focal length. A control device for preventing image blur is provided with control means for reducing the operating range of the image blur prevention means for preventing image blur, and for preventing the influence of aberration on the image from becoming too large. .

In order to achieve the second object of the present invention, the present invention as claimed in claims 5 to 8 prevents image blur by moving in the optical path according to the contrast of the image to be image blur preventive. And a control unit for changing the operating range of the image blur prevention unit for preventing image blurring by which an image with remarkable aberration is not formed due to the contrast of the image. Is.

In order to achieve the third object of the present invention, the present invention as claimed in claims 9 and 10 prevents image blur by moving in the optical path according to the resolution of the image to be image blur preventive. In order to prevent the image blurring, the control unit for changing the operating range of the image blurring prevention unit is provided, and the control unit for preventing the image blurring can prevent the aberration from becoming conspicuous depending on the image resolution. is there.

In order to achieve the fourth object of the present invention, the present invention as set forth in claims 11 and 12 is achieved by moving in the optical path according to the state of the electrical processing of the image to be image-stabilized. An image blur prevention device that includes a control unit for changing the operating range of the image blur prevention unit for preventing image blur and can prevent the aberration from becoming conspicuous depending on the state of electrical processing of the image. Is a control device for.

[0060]

【Example】

(First Embodiment) FIG. 1 shows a block diagram of a first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a focal length sensor, which is a sensor for detecting the position of the variator lens of the zoom lens. For example, in FIG. 19, the lens 112 is at the variator position, so the position of this lens is detected. There are various possible detection methods. For example, a method of detecting by sliding on a fixed variable resistance pattern that a brush is integrally provided on the lens barrel that fixes this lens, or movement of this lens group is used. There is a method in which a step motor is provided and the position is detected by continuously counting the number of drive pulses input to the step motor from the reference position.

Reference numeral 2 denotes maximum shake angle data, which is stored in a microcomputer as a table corresponding to the focal length.

That is, conventionally, as shown in FIG. 22, no information of the photographing lens is used in the shake preventing device including the variable apex angle prism, but in the first embodiment, the focal length is changed. The above information is taken into a variable apex angle control microcomputer for preventing blurring, and the maximum deflection angle of the variable apex angle prism to be used is regulated based on the detection result.

Even when other optical shake correcting means such as a method of moving the correction optical system using a gimbal is used, the present invention is similarly implemented by restricting the movable range of the movable portion. Is possible.

The chromatic aberration of magnification caused by using the prism will be described with reference to FIG. When white light is incident on a prism having an angle as shown in the figure, the emitted light undergoes an angle shift according to the wavelength. Therefore, if such a prism is arranged in front of the image-forming optical system, the image-forming position changes depending on the wavelength, resulting in a color-blurred image. In particular, color misregistration is likely to be noticeable on black and white edges with high contrast.

Generally, in designing a zoom lens or the like, a design (achromatism) that suppresses the influence of this chromatic aberration is performed, but when a variable apex angle prism is used, the amount of color misregistration also changes depending on the apex angle state. Becomes That is, the color shift due to the variable apex angle prism is 0 in the standard state (the state where the two glasses are parallel), but the amount of color shift increases as the apex angle increases.

FIG. 3 shows the relationship between the focal length and the color shift, and the relationship between the focal length and the optical axis correction angle when the variable apex angle prism is in the maximum use angle state.

The color shift referred to herein means a shift in image forming position between light beams of two wavelengths on the image forming surface.

In the figure, the relationship between the focal length and the color misregistration is written on a log-log graph. It is assumed that the optical axis correction angle is 1 ° at any focal length. If the angle of the variable apex prism is θ, the optical axis correction angle is ε, and the refractive index of the liquid inside the variable apex prism is n, then ε = (n−
1) × θ, which is the same value if a constant maximum apex angle is set regardless of the focal length. On the other hand, the influence of chromatic aberration becomes more noticeable as the focal length becomes longer (the graph of the focal length and the color shift is indicated by a dashed line).

On the other hand, the case of the first embodiment of the present invention is shown in FIGS. FIG. 4A is an example in which the focal length that reaches a predetermined amount of color misregistration is set as a boundary, and the maximum shake angle is set to be small so that the color misregistration becomes a predetermined value on the long focus side.

FIG. 4B shows a case where the set value of the maximum use apex angle is gently changed according to the focal length so that a predetermined color shift occurs at the longest focal length.

It is preferable to reduce the maximum shake angle on the long focal length side in this way for the following reason. That is, according to the study by the inventors, the amount of camera shake that occurs when a stationary subject is photographed in a normal hand-held state is from ± 0.3 ° in optical axis angle to at most 0.5 °. Dominate. On the other hand, when the camera is shaken for panning etc., in order to drive and control the variable apex angle prism without feeling uncomfortable, it is necessary to use much larger than the optical axis correction angle required to eliminate the effect of camera shake on this stationary subject. The impression that the angle of the variable apex prism reaches the end of its use angle range when panning is performed, unless the angle range is provided and a sufficient movable area is secured for panning control Will occur. On the contrary, if the use angle range is set to a large value, low-frequency and large-amplitude vibration may remain during normal image stabilization. This is often due to the characteristics of the shake detection sensor, the characteristics of the filter provided for the output of the shake detection sensor, or the like.

On the other hand, in consideration of actual photography, panning and the like are often used in the wide to middle focal lengths, and at the telephoto end (longest focal length) (of course, depending on the numerical value, for example, 35 mm of a film camera). The situation is equivalent to 400 mm of format) It is rare to use panning a lot.

From the above, generally, if the maximum vertical angle range at the telephoto end is restricted as in the present invention such that the correction is not insufficient (for example, 1 °), the stationary subject is stopped. When shooting, it is possible to fully prevent camera shake, and even if a slight jarring feeling during panning occurs, it can contribute to reducing the residual vibration of the low-frequency large-amplitude screen, thus preventing total camera shake. The performance is more preferable.

When a large angle is required for blur correction in a special case (such as photographing from a car or a ship), it is possible to deal with it by manually setting a shake angle by a photographer in an embodiment described later.

FIG. 5 shows a flowchart for setting the target apex angle value of the microcomputer 45 of the first embodiment.

Start at step 1. In step 2, the focal length information at that time is read from the detection result of the focal length sensor 1. Next, in step 3, the maximum shake angle (vertical angle) data 2 is read from the maximum shake angle value corresponding to the focal length at that time. In step 4, the value θ _M is set. In step 5, the detection result from the shake detection sensor is read as the apex angle θ _P for correcting it. In step 6, both values are compared. As a result, if θ _P is smaller, in step 7, θ _P is set as the target apex angle position θ. If the result of step 6 is that θ _P is larger, then in step 8, θ _M is set as the target apex angle position.

(Second Embodiment) In the first embodiment, the contents of changing the maximum use vertical angle (deflection angle) based on the focal length information have been shown. In the second embodiment of the present invention, not only this maximum usable apex angle, but also a threshold value for the angle used for control, a coefficient between the output of the shake detection means and the apex angle displacement amount, etc. Also provides a higher-performance shake prevention device by changing the setting.

FIG. 6 is a block diagram showing the essential structure of the second embodiment. This configuration is different from the first embodiment in that
Further, it has K and θ _T data 3, which is a coefficient between the maximum shake angle, the output of the matching shake detecting means, and the apex angle displacement amount according to the detection result of the focal length. By making the K value and θ _T variable, it is possible to achieve a blurring prevention device with less discomfort. Note that, in the figure, the description of the same configuration as in FIG. 1 is omitted here.

The K value will be described with reference to FIG. Figure 7
In the figure, the horizontal axis indicates the angle change of the photographing optical axis by driving the variable apex angle prism or the correction optical system (0 °).
Is the standard position). As described above, in the case of photographing a stationary subject in a stationary state, if there is a correction angle range of about ± 1 °, blur correction can be performed. On the other hand, when a large shake angle is detected by the shake detection means due to panning etc., if it is completely corrected, the subject will stop and the picture will be taken even if the camera is shaken at the start of panning. When the panning is stopped, even if the camera is stopped, it will be recorded as if the panning continues.

Therefore, in many cases, with respect to such a large amplitude, the target position in the microcomputer 45 does not follow the detection result of the blur detecting means, but is reset to a smaller target position. ing. There are various methods for this purpose. For example, the detection result of the shake detection means is set to θ _P , the target position is set to θ, the threshold angle is set to θ _T1 , and the coefficient K is set, and then θ _P ≦ θ _{When T1} is θ = θ _P θ _T1 <θ _P <θ _M When θ = θ _T1 + (θ _P − θ _T1 ) × K, the target apex angle (deflection angle) is calculated.
Set (However, when each value is positive).

FIG. 7 shows the relationship between θ and θ _{P in} this case. In the range where the absolute value is larger than the threshold angle θ _T1 , the target apex angle (deflection angle) is set small. FIG. 8 shows a practical set value. A zoom lens having a focal length of f _W to f _T is used for intermediate focal lengths f _M1 and f _M2 .
Consider the three areas III to III (equal division is desirable on a logarithmic graph). When the focal lengths of the respective areas are present, the respective values are set as shown in FIG. As a result, the relationship between θ and θ _P is as shown in FIG. In the figure, the solid line indicates the case of the region I, the broken line indicates the case of the region II, and the alternate long and short dash line indicates the case of the region III.

FIG. 10 is a flow chart showing the operation of the microcomputer for controlling the drive of the variable apex angle prism with the characteristics shown in FIGS. Start in step 1, and detect the focal length state in step 9. In step 10, thresholds θ _T1, K, and θ _M are determined from the information provided in the microcomputer as shown in FIG. In step 12, a value θ _{P which} is the detection result from the blur detection means and which is the dimension of the vertical angle or the deflection angle is read. In step 13, the absolute value of θ _P and θ _T1
When the absolute value θ _P is small as a result, θ _P is set as the target value θ in step 14. If the absolute value θ _P is larger than θ _T1 , the magnitude comparison with θ _M is further performed in step 15. If the absolute value θ _P is larger than θ _M , a positive / negative judgment is made in Step 16, and if positive, θ _M is set as θ in Step 18,
If negative, step 17 sets −θ _M. If the absolute value θ _P is equal to or less than θ _M in step 15, a positive / negative judgment is made in step 19, and if positive, step 20
If it is negative, the target position is calculated in step 21 according to the above equations.

Although the focal length is divided into three areas in this example, it may be divided into more areas or into two areas. Also,
It is also possible to provide a plurality of threshold angles instead of one and set the K value finely according to each. Further, instead of determining the coefficient or threshold value in the table as in this example, a method of providing an arithmetic expression between the target angle θ and the shake detection angle θ _P and calculating the target apex angle (deflection angle) is also considered. .

Needless to say, the relationship between θ and θ _P is not limited to the linear relationship shown in FIG.

(Third Embodiment) In the first and second embodiments, the maximum apex angle, a threshold value for control, or a coefficient between the output of the shake detecting means and the apex angle displacement amount is set according to the focal length. By making it variable, the amount of color misregistration can be suppressed to a predetermined value or less, and at the same time, the blur prevention performance that is practically desired is achieved.

In the third embodiment of the present invention, not only the focal length information but also the object of which the color shift is noticeable is judged from the value of the focus voltage of the automatic focusing device using the high frequency component of the video signal, and this information is obtained. Based on this information or the above focal length information, the maximum apex angle (deflection angle) as shown in the first and second embodiments, or the threshold value for control and the above-mentioned coefficient setting can be set. It presents what to do.

FIG. 11 is a block diagram showing the arrangement of the main parts of the third embodiment. Note that the description of the same configuration as that of FIG. 1 is omitted here. The information formed on the CCD 151 is processed by the camera processing circuit 152 into a predetermined TV signal, for example, an NTSC signal in Japan. Of these, the Y signal corresponding to the luminance is taken into the AF circuit 153, where the high frequency component of the Y signal is obtained as the focus voltage.
12 (A) to 12 (C) explain this focus voltage.

In FIG. 12A, the black portion 27 on the subject is shown.
There are 2 and other white parts, and the Y signal of the signal acquisition area 271 for automatic focus detection is 2 in FIG.
It looks like 73. 274 in FIG. 12C is a signal obtained by differentiating this signal 273, and the peak height V _{F of} this signal is
Becomes the focus voltage.

In general, it can be said that a black-and-white edge portion has a noticeable color shift, that is, an object having high contrast. Therefore, the microcomputer 45 sets a certain threshold value for the focus voltage, and when the focus voltage exceeds the threshold voltage, it is determined that the subject has a high contrast, and for example, the focal length of the area I in FIG. But III
It is possible to suppress the occurrence of color misregistration by changing the setting to each value of.

FIG. 13 shows an example of this selection table.
The combination of the respective values I to III shown in (3) is selected from both the focal length and the contrast state determined from the focal voltage.

There are various conceivable methods for detecting the contrast in addition to the method using the focus voltage of the automatic focusing device as described above. For example, in general, a bright subject often has a higher contrast than a dark subject. From this point, it is also possible to roughly determine the contrast based on the aperture information.

FIG. 14 is a block diagram showing a configuration for performing this control, and the description of the configuration similar to that of FIG. 1 is omitted here. Then, in this configuration, the detection result of the diaphragm encoder 150 is taken into the microcomputer 45, and the maximum apex angle (deflection angle) is set by this information.

Incidentally, in combination with FIG. 14, it is of course possible to use the focal length information and the focus voltage information as the judgment material. 11 and 14, only the block 1 of the maximum deflection angle data is shown, but the block 3 of the K and θ _T data described in the second embodiment may be added.

(Fourth Embodiment) The present invention controls the optical blur correction means so that the image quality is not deteriorated by the color shift. However, it is determined whether the color shift affects the image quality. It depends on the format of the record. As is well known, as a home video format,
8mm and Hi8, V as its high band version
HS and S-VHS as a high band version thereof are mentioned. The effect of color shift is more difficult to understand in the normal version than in the high band version. From this, in the fourth embodiment, it is proposed to switch between the case where the control is changed as shown in the first to the third embodiments and the case where it is not changed according to the recording format.

FIG. 15 is a block diagram showing the arrangement of the main parts of the fourth embodiment. Note that the description of the same configurations as those in FIGS. 6, 11, and 14 is omitted here. In the configuration of FIG. 15, the recording format is detected at block 276, and this information is sent to the microcomputer 45.

FIG. 16 is a flowchart for determining the target value. Start at step 22. If the recording format is 8 mm or Hi8 in this example in step 23, and if it is 8 mm, the control change as shown in the first to third embodiments is not performed and θ = θ _{P in} step 24. I am trying. In the case of Hi8, for example, the flow chart shown in FIG. 10 is connected.

FIG. 16 is an example, and the standard (8 mm,
In the case of (VHS), for example, a combination of the values of II shown in FIG. 8 may be fixed and used. Furthermore, the detection result of the recording format can be used in the same row as the focal length, the focal voltage, and the aperture value.

(Fifth Embodiment) In the fifth embodiment, the present invention is applied to a video camera or the like in which the signal processing of the camera is digitized and an electronic enlargement function (so-called electronic zoom function) associated therewith is provided. FIG. 17 and FIG. 1 describing the case
8 shows a fifth embodiment.

In FIG. 17, the parts having the same numbers as those in FIGS. 15 and 28 show the same functions. Reference numeral 278 denotes a digital signal processing circuit of a camera including A / D conversion, which has an AF circuit incorporated therein. 279 is an I for digital effects
At C, enlargement for electronic zoom and other processes for obtaining various effects are performed. Reference numeral 280 denotes a digital effect operation unit operated by a photographer, and 281 denotes D / A conversion.

In this case, in the above embodiment, the information for selecting the maximum apex angle (deflection angle), K, θ _T, etc. is sent from the lens control CPU 154 to the blur prevention microcomputer 45. To be When the photographer operates the zoom external operation key 157, if the operation in the tele direction continues even though it is already at the optical tele end, a command is sent to the digital effect IC to enter the electronic zoom range, The information is also transmitted from the CPU 154 to the microcomputer 45.
The microcomputer 45 sets the maximum apex angle or the values of K and θ _T from these information.

FIGS. 18A and 18B show the setting of the maximum apex angle when the electronic zoom region is continuously provided at the tele end of the optical zoom. In FIG. 4A, the setting of the maximum apex angle is made variable while entering the electronic zoom range, and the influence of color misregistration is set to a predetermined value or less.

FIG. 18B shows that the setting of the maximum apex angle (deflection angle) is gently changed from the optical zoom range to the electronic zoom range.

(Sixth Embodiment) By changing various control values of the image stabilizing apparatus according to various information such as the focal length as described above, the influence of color misregistration is removed and the focal length is adjusted. Although control is possible, in actual shooting, for example, there may be a case where it is desired to prevent camera shake with a large amplitude even if color misregistration occurs to some extent.

For example, shooting from the ship is equivalent to this.

In such a case, it is possible to configure so as to turn off the control change performed in the fifth embodiment by mode switching 277 by the photographer in FIG. is there.

In the present invention, each structure of the claims or the embodiments or a part of the structures may be provided in a separate device.
For example, the shake detection device may be provided in the camera body, the shake correction device may be provided in the lens barrel attached to the camera, and the control device for controlling them may be provided in the intermediate adapter.

In the present invention, the shake preventing means is not limited to the means for directly preventing shake, and it is possible to detect that shake has occurred or may occur.
It is also possible to use a sound or the like to warn the user so that the shake does not occur indirectly.

In the present invention, as the shake detecting means, an angular accelerometer, an accelerometer, an angular velocity meter, a speedometer, an angular displacement meter, a displacement meter,
Further, any method can be used as long as the shake can be detected, such as a method of detecting the shake itself of the image.

In the present invention, as the shake prevention means, a shift optical system for moving an optical member in a plane perpendicular to the optical axis, a light beam changing means such as a variable long-angle prism, or a photographing surface in a plane perpendicular to the optical axis. Any device that can prevent the shake, such as a mover, a shake correction by image processing, etc., may be used.

The present invention is also applied to a case where an image blur preventing means such as a variable apex angle prism is provided in an interchangeable lens which can be attached to both a silver halide camera and a video camera,
When the interchangeable lens is attached to the video camera, the operating range of the image blur prevention unit may be made larger than when attached to the silver halide camera.

That is, since the image plane (CCD) of a video camera is generally smaller than the image plane of a silver halide camera, the area in which aberration must be taken into consideration is naturally small, and the image blur prevention means can be displaced to a greater extent. become. The above example uses this to change the operating range,
If possible, the image blur prevention is performed in a wide range.

In the above embodiment, the microcomputer 45 corresponds to the control means of the present invention.

The above is the correspondence relationship between each configuration of the embodiments and each configuration of the present invention, but the present invention is not limited to the configurations of these embodiments, and the functions or embodiments shown in the claims or the embodiments Any structure may be used as long as the function of the structure can be achieved.

Further, the respective embodiments or their technical elements may be combined as required.

[0115]

According to the control apparatus for preventing image blur of the present invention, the operating range of the image blur prevention means is reduced in accordance with the increase of the focal length, so that the focal length becomes longer. As a result, even if the influence of the aberration becomes large, it becomes possible to prevent the occurrence of the aberration from becoming too large, and it is possible to prevent the deterioration of the image.

Further, according to the control device for preventing image blur of the present invention, since the operation range of the image blur prevention means is changed according to the contrast of the image, the degree of influence of aberration due to the change of contrast. Always changes,
The degree of influence can be kept within the allowable range, and the deterioration of the image can be prevented.

Further, according to the control device for preventing image blur of the present invention, the operating range of the image blur prevention means is changed according to the resolution, so that the influence of the aberration is conspicuous due to the change of the resolution. Even if there is a change, it becomes possible to keep the degree of the effect conspicuous within the allowable range, and prevent deterioration of the image.

Further, according to the control apparatus for preventing image blur of the present invention, the operating range of the image blur prevention means is changed according to the electrical processing state of the image. Even if the conspicuous degree of the influence of the aberration changes due to the change of, it becomes possible to always keep the conspicuous degree of the influence within the allowable range, and it is possible to prevent the deterioration of the image.

[Brief description of drawings]

FIG. 1 is a block diagram showing a main configuration of an apparatus according to a first embodiment of the present invention.

FIG. 2 is a diagram for explaining the principle of occurrence of chromatic aberration.

FIG. 3 is a graph showing a relationship between conventional focal length and color shift.

FIG. 4 is a graph showing a relationship between a color shift and a focal length in the device according to the first embodiment of the present invention.

FIG. 5 is a flow chart showing the operation of the device of the first exemplary embodiment of the present invention.

FIG. 6 is a block diagram showing a main configuration of an apparatus according to a second embodiment of the present invention.

FIG. 7 is a graph showing a target apex angle of a conventional blur correction unit.

FIG. 8 is a table showing a setting example of each coefficient in the second embodiment device of the present invention.

FIG. 9 is a graph showing a target apex angle in the device according to the second embodiment of the present invention.

FIG. 10 is a flow chart showing the operation of the device of the second exemplary embodiment of the present invention.

FIG. 11 is a block diagram showing a main configuration of an apparatus according to a third embodiment of the present invention.

FIG. 12 is a schematic explanatory diagram of a focus voltage of the automatic focus adjustment device.

FIG. 13 is a setting combination table of each coefficient according to the third embodiment of this invention.

FIG. 14 is a block diagram showing a main configuration of a modification of the third embodiment of the present invention.

FIG. 15 is a block diagram showing a main configuration of a fourth embodiment of the present invention.

FIG. 16 is a flow chart showing the operation of the apparatus of the fourth exemplary embodiment of the present invention.

FIG. 17 is a block diagram showing a main configuration of fifth and sixth embodiments of the present invention.

FIG. 18 is a graph showing the relationship between color shift and focal length in a fifth example of the present invention.

FIG. 19 is a diagram for explaining the principle of a variable apex angle prism.

FIG. 20 is a diagram for explaining the principle of image blur correction by an image blur correction unit using a variable apex angle prism.

FIG. 21 is a perspective view showing a variable apex angle prism drive unit.

FIG. 22 is a block diagram showing a main configuration of an image blur prevention device using a variable apex angle prism.

FIG. 23 is a cross-sectional view of a variable apex angle prism.

FIG. 24 is a diagram showing a lens having a correction optical system.

FIG. 25 is a diagram showing a gimbal support structure of a correction optical system.

FIG. 26 is a sectional view of a general zoom lens of a video camera.

FIG. 27 is a diagram for explaining a zoom tracking curve.

FIG. 28 is a block diagram showing a main configuration of a zoom lens control system.

FIG. 29 is a diagram illustrating an example of area division for zoom tracking.

FIG. 30 is a diagram illustrating an example of zoom tracking speed setting.

FIG. 31 is a diagram showing a state in which a zoom lens and a variable apex angle prism drive unit are combined.

[Explanation of symbols]

1 Focal length sensor 2 Maximum deflection angle data 3 K, θ _T data 41 Variable apex angle prism 45 Microcomputer 150 Aperture encoder 152 Camera processing circuit 153 AF circuit

Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical display location G02B 7/08 C 7/28 G03B 13/36 17/00 Z H04N 5/225 B 5/232 Z

Claims (12)

[Claims] 1. An image comprising control means for reducing an operation range of an image blur prevention means for preventing image blur by moving in an optical path in response to a longer focal length. Control device to prevent blurring. 2. The image blur prevention means performs an image blur prevention operation by moving in a light path to change a passing light beam, and is arranged in front of an optical axis of an optical means for changing a focal length. The control device for preventing image blur according to claim 1, wherein: 3. The image blur prevention unit performs an image blur prevention operation for preventing image blur detected by an image blur detection unit for detecting image blur within a predetermined range, and the control unit controls the predetermined amount. 2. The control device for preventing image blur according to claim 1, wherein the range is made smaller as the focal length becomes longer. 4. The image blur prevention unit performs an image blur prevention operation within a first predetermined range and performs the image blur prevention operation within a second predetermined range different from the first predetermined range. 2. The control device for image blur prevention according to claim 1, wherein the control means reduces the second predetermined range in accordance with the increase of the focal length. 5. A control means for changing the operation range of the image blur prevention means for preventing image blur by moving in the optical path according to the contrast of the image blur prevention image. Control device for preventing image blurring. 6. The control device for image blur prevention according to claim 5, wherein the control means determines the contrast according to a focus voltage of the automatic focus detection means. 7. The control device for preventing image blur according to claim 5, wherein the control means determines the contrast according to the state of the diaphragm. 8. The control device for preventing image blur according to claim 5, wherein the control means reduces the operating range in response to the increase in the contrast. 9. Depending on the resolution of the image to be prevented from blurring,
A control device for preventing image blur, comprising control means for changing an operation range of the image blur prevention means for preventing image blur by moving in an optical path. 10. The control device for image blur prevention according to claim 9, wherein the control means changes the operation range in response to the increase in the resolution. 11. A control means for changing the operating range of the image blur prevention means for preventing the image blur by moving in the optical path according to the state of electrical processing of the image blur-prevented image. A control device for preventing image blur, which is characterized by: 12. The image blur prevention according to claim 11, wherein the control unit changes the operation range according to an enlargement situation of the image blur prevention image by an electronic enlargement function. Control device.