JPS6258784A - Shock proof image pickup device - Google Patents

Abstract

PURPOSE:To pickup a picture without any blur even by a beginner by detecting the relative motion of different drive means causing the relative motion between an image pickup means and an object image formed thereupon and applying selectively or synchronizingly the drive means based on a detection output. CONSTITUTION:The output of a photoelectric transducer 2 enters a picture blur detection circuit 8b through a signal processing circuit 8a. The amplitude and direction of a picture blur are detected by taking correlation between pictures at a prescribed time in the circuit 8b and a control signal is given to a driving control circuit 8c. The driving control circuit 8c receives the control signal to drive motors 5a, 5b in a direction cancelling the picture blur. Thus, even when an external disturbance is applied to the outer package member 6 of a camera, the picture blur correction is applied. As a result, since a lens system 1 and the photoelectric transducer 2 are kept opposed to the object, a stable picture without blur is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an imaging device having a vibration isolator section, and although it can also be used for still photography, it particularly relates to an imaging device suitable for movie photography.

<Prior art> Shooting while walking or on a moving vehicle tends to cause the camera to shake, making it difficult to view the shooting screen.Also, shooting in a place with a lot of vibration tends to cause blurring in the image, making it difficult to obtain a useful image. Moreover, these problems become more pronounced as the focal length of the lens system becomes longer.

As a means to prevent such problems due to image blur, it is possible to decenter a part of the lens system by detecting the tilt angle of the entire optical system, that is, the blur of the optical system, or to change the thickness of each lens as described in Japanese Patent Publication No. 59-26930. A method has been proposed in which two optical elements defined by a certain relational expression are provided in the optical path of a photographing lens and the optical elements are shifted to prevent image blur. However, in the former case, the amount of light may fluctuate due to eccentricity, and in the latter case, at least one optical element is placed in front of a normal lens system.
111-111
This has the disadvantage that the entire optical system is heavy and thick because it requires a large diameter lens. In addition, a so-called Dynalens method for preventing image blur has been proposed, which corrects image blur by controlling the apex angle of a liquid prism, but due to its structure, the angle of image blur that can be corrected is small, and it uses a prism. There is a problem in that as the angle increases, chromatic aberration occurs.

In addition, as mentioned above, in contrast to the method of optically preventing image blurring, there is a method that uses a gyro as an imaging device with an anti-vibration device so that the camera is always fixed in the direction of gravity, and a method that uses a motorized camera to which the camera is attached. A method that drives the entire camera, including the photographic lens, according to the acceleration and angular velocity detected by an acceleration sensor on the pan head (“Servo-type camera vibration isolation device” NHK Giken Monthly Report vol. 1.27. Ilk+, 11 P23-2B
(1984)) have been proposed.

This method does not cause variations in the amount of light, does not make the entire optical system heavy and large, and does not cause chromatic aberrations, unlike the above-mentioned method of optically preventing image blur. However, in the camera shown in this proposal, Since not only the photographic lens but also the entire camera housing, including the control device inside the camera, is driven by a motor, the entire imaging device including the image stabilization device is large, so when shooting hand-held like an ENG camera, There were some drawbacks that made it unusable.

The present applicant previously disclosed in Japanese Patent Application No. 60-90116 a photographic lens device having a photographic lens system and a light receiving means for receiving light incident through the photographic lens, which is rotatably supported with respect to a camera housing. The present invention proposes an anti-shake camera that includes a control means for correcting blur by driving the photographing lens device in accordance with the output of a detection means for detecting blur in the lens device.

The proposed anti-shake camera has the following features: 1) There is no need to decenter a part of the lens system or insert a prism, so there is no change in light intensity or deterioration of the optical properties of chromatic aberration, and the correction range can be widened. .

2) Since the objects of drive control are only the lens system and the photoelectric conversion element, the power of the drive system can be small, and as a result, the entire camera can be made smaller and lighter.

3) Since the entire camera has been made smaller, it is now possible to take handheld shots with a long focal length lens, and stable images without blur can be obtained even when taking handheld shots while walking, and can also be used on moving vehicles or in locations with a lot of vibration. You can obtain stable images without blur even when shooting at high speeds. Additionally, even beginners who are unaccustomed to hand-held shooting can take images with almost no blur.

Problems to be solved〉 However, although the lens system weighs less than the entire camera, it has a considerable moment of inertia.
Even if the amplitude is small, it is difficult for the drive system to follow high-frequency vibration components, which limits the scope of use. vice versa,
There is a similar problem because the operating range of the drive system is structurally limited in response to large-amplitude shakes.

This invention eliminates the drawbacks of the above-mentioned conventional example, and converts the low-frequency, large-amplitude component into the high-frequency, small-amplitude component h<8l-f.
- An object of the present invention is to provide an imaging device having an anti-fraud lottery even if it is stolen or stolen.

One method for achieving the above object is to provide mutually different driving means for causing relative movement between the imaging means and the object image formed thereon, and for causing relative movement between the imaging means and the object image. A motion detecting means for detecting the motion detecting means, and a means for selectively or synchronously driving and controlling the driving means based on the output of the motion detecting means are provided.

<Description of Examples> Examples of the present invention will be described below with reference to the drawings.

Fig. 1 is a block diagram showing a schematic configuration of an embodiment of the present invention, and Fig. 2 is a sectional view showing the configuration. 1
In the figure, 8 b' indicates the direction and amount of movement of the image of the subject 14 on the imaging surface of the photoelectric conversion element 2 (hereinafter, image blur directions, respectively).

The image movement detection circuit 80' is an image movement detection circuit which is an image blur detection means for detecting the amount of image blur (referred to as the amount of image blur).
A control circuit is a means for selecting and controlling the driving means 11-13 by the output of ', 11 is a second driving means that corresponds to high frequency and small amplitude image blurring, and 13 corresponds to low frequency and large amplitude image blurring. A third driving means 12 corresponds to an image blur of an intermediate frequency and amplitude between these two driving means.

A member 15 is fixed to the housing 6 and transmits the driving force of the third driving means 13 to the housing.

FIG. 3 is a perspective view showing one example of the first driving means. 1 is a lens system including a hood, 2 is a photoelectric conversion element such as a solid-state image sensor, and is an imaging means that receives light incident through the lens system 1. 3 is a gimbal structure that is a means for supporting the lens system l and the photoelectric conversion element 2; 31a,
It consists of two shafts 31b and 32a, 32b (not shown) and an annular member 33. One end of the shafts 31a and 31b is fixed to the annular member 33, and the other end is rotatably attached to the upper surface 6a and lower surface 6b of the exterior member 6, which is the camera frame, respectively. Also, the shaft 32a.

32b has one end fixed to the lens barrel of the lens system 1, and the other end rotatably attached to the annular member 33. Therefore, the lens system 1 and the photoelectric conversion element 2 are
It is rotatably supported around the axis and the Z axis. 4a
, 4b are worm gears with shafts 32a and 31, respectively.
The driving force of the motors 5a and 5b is transmitted through the worm wheels 34 and 35 fitted to the worm wheels 34 and 35, and the lens system 1 and the photoelectric conversion element 2 are rotated around the two axes of the gimbal 3.

The motor 5a is fixed to the annular member 33 of the gimbal, and the motor 5b is fixed to the bottom surface 6b of the camera exterior member 6. 7 is a signal transmission member for transmitting the output of the photoelectric conversion element 2 to a circuit board 8 including a signal processing circuit 8a shown in FIG. 2, a one-image pre-detection circuit 8b, and a drive control circuit 8c; This is a coaxial cable for transmitting data to the monitor lO shown in FIG. In FIG. 1, a photographic lens device having a photographic lens system 1 and a photoelectric conversion element 2 is shown as 30.

The operation of the first driving means configured as above will be explained below.

In FIG. 1, the output of the photoelectric conversion element 2 passes through a signal processing circuit 8a and enters an image pre-detection circuit 8b. Here, the magnitude and direction of image blur are detected by correlating images separated by a certain time, and a control signal is provided to the drive control circuit 8C. The drive control circuit 8C receives the control signal and drives the motor 5 (5a, 5b in FIG. 1) in a direction to cancel image blur. Therefore, even if a disturbance is applied to the exterior member 6 of the camera, the correction is performed as described above, and as a result, the lens system l and the photoelectric conversion element 2 are kept facing the subject, resulting in a stable image without blurring. An image is obtained.

Reference numeral 11 in FIG. 2 indicates a second driving means, which is, for example, a method of suspending a relay lens behind the afocal optical system, and the details of the suspension mechanism are as follows.

FIG. 4 is a front view (A) and a side sectional view CB) showing an example of the configuration of the second driving means 11.

In the figure, 101 is a lens barrel, and 102 is a lens.

103 is a lens frame, and 18aNd is a laminated piezoelectric suspension. Reference numeral 17 is a member having one surface fixed to the piezoelectric element 18 and the other surface having a concave surface and fitting into the lens frame 103 to slidably support the lens frame 103.

Here, when a voltage is applied in a direction to expand the piezoelectric element 18a and compress the piezoelectric element 18b, the lens frame 103 is supported by the left and right support members 17 in FIG. 4(A) and is slid downward. . That is, since the lens 102 is decentered in the direction perpendicular to the optical axis, the image of the subject 14 on the imaging surface of the photoelectric conversion element 2 can be moved downward (in the 12 directions in FIG. 4) due to the prism effect. . Similarly, piezoelectric elements 18c, ! By changing the direction of voltage application using the combination l:18d, it is possible to move the image of the subject 14 in the y direction. That is, piezoelectric elements 18a and 18b, 18c and 1
By changing the direction (polarity) and magnitude of the voltage applied to 8d, it is possible to move the image of the subject 14 within the yz plane by a small amount but at high speed.

As already mentioned, the first driving means 12 is a combination of the motor 5 and the gear 4 shown in FIG. and rotate around the Z axis. Further, as the third driving means 13, for example, a well-known electric pan head can be used, which can rotate the housing 6 around the y-axis around the point O and around the Z-axis around the member 15.

The operation of the imaging apparatus of this embodiment configured as described above will be described below. In FIG. 1, photoelectric conversion element 2
The output passes through the signal processing circuit 8a and enters the image movement detection circuit 8b'. Here, the direction and amount of image blur are detected by, for example, correlating images separated by a certain time, and an image pre-signal So is transmitted to the control circuit 8c'. At this time, the correlation is in the y direction and Z on the imaging surface of the photoelectric conversion element 2.
Since the image pre-signals So are often performed separately in each direction, two types of image pre-signal So can be obtained, one in the y direction and the other in two directions, but for simplicity, only the y direction will be considered below. now,
Image pre-signal S0 as shown in FIG. 5 for time t
(Assuming that (a) in the figure) is obtained, the control circuit 8cj separates the signal So into three parts and passes each of them through a low-pass filter, a band-pass filter, and a bypass filter to generate a new image pre-signal S3 ( Figure (b))
, Sz ((C) in the same figure) and Sl ((d) in the same figure) are generated. Then, the signals 31 to S3 are converted into control signals C1 to C3 corresponding to the first to third drive means 11 to 13, and outputted to each drive means. Each drive means outputs the image pre-signal S according to the control signals C□ to C3.

moves in the direction where becomes zero. That is, in this case, the second drive means 11 drives the fourth drive means 11 so that the image pre-signal S1 becomes zero.
The piezoelectric elements 18c and 18d in the figure are driven, and the third drive means 12 drives the piezoelectric elements 18c and 18d so that the image pre-signal S2 becomes zero.
The motor 5b in the figure is driven, and the third drive means 13 rotates the member 15 so that the image pre-signal S3 becomes zero.

Note that similar all operations are performed in two directions on the imaging surface of the photoelectric conversion element 2.

As described above, the image of the subject 14 is held at a constant position on the imaging surface of the photoelectric conversion element 2, so a stable image without blur can always be obtained.

Note that C4 is a control signal from a controller (not shown), and the control signal C4 can also be used to perform operations such as panning using the third driving means 13 that can cope with low-frequency, large-amplitude image blurring.

FIG. 6 shows another configuration example of the second driving means, in which 20 is a substrate on which the photoelectric conversion element 2 is fixed, 19a
-d is a bimorph type piezoelectric element, 21 is the piezoelectric element 19a
, 19b pair and 19c.

This is a member that connects the pair 19d. 19a.

A pair of piezoelectric elements 19b is adhesively fixed at one end to the substrate 20 and at the other end to the connecting member 21, and 19c.

One end of the pair of piezoelectric elements 19d is adhesively fixed to the connecting member 21, and the other end is adhesively fixed to the casing (not shown) of the imaging device. In the above configuration, by changing the polarity and magnitude of the voltages applied to the piezoelectric elements 19a and 19b and 19c and 19d, the photoelectric conversion element 2 can be displaced in the Z direction and the y direction, respectively. That is, if the position of the subject image 14 is set to the optical axis, the distance between
-B As in the case of Figure 4, the image pre-signal (Sl) can be made zero.

In FIG. 7 showing another example of the configuration of the second driving means, reference numeral 22 indicates a circumferential plane of glass plates 28a, 28b.
Elastic bodies 27a and 27b, such as silicone rubber, on the disk which has been rejuvenated are attached to the holding frame 2 of the glass plate 28.
3a, 23a (not shown) and 23b, 23
b' is a shaft 24a, 24 whose one end is fixed to the holding frame 27 and whose other end is rotatably attached to and supported by a lens barrel (not shown);
b connects the driving force of the motors 25a, 25b attached to the lens barrel to the shafts 23a, 23b via ohm wheels 26a, 26b fitted to the shafts 23a, 23b, respectively.
It is a worm gear that transmits the

In the above configuration, by driving the motors 25a and 25b, the glass plate 28a can be rotated around the y-axis and the glass plate 28bIl-z axis, and the optical axis (in the X direction) can be rotated on the end surface of the elastic body 22. ) can have an angle to it. Then, the position of the imaging surface of the photoelectric conversion element 2 of the subject image 14 can be changed due to the prism effect, so the image pre-signal can be made zero as in the case of FIG. 4.

In the embodiments described below, a method of taking a correlation using an image signal as an image pre-detection means was mentioned, but it is also possible to attach an acceleration sensor to the frame of the imaging device and send data to the control circuit 8c' according to its output. The signal output may also be varied.

Next, as a first stage of control, we have described a method in which the image pre-signal is passed through a filter and separated into bands corresponding to each f-drive stage to generate a control signal for each f-drive stage. A similar effect can be obtained by providing different gain-frequency characteristics.

Furthermore, as shown in the embodiment, three driving means are not necessarily required. For example, in the case of hand-held photography such as an ENG camera, the third driving means 13 and the member 15 are moved from the casing 6. It is also possible to display an image preview (or camera shake) warning display in the viewfinder using the control signal C3 to alert the photographer. In addition, it can be used as an imaging device with an image stabilization function even during manual shooting. Conversely, the third driving means can also be used to perform bunning.

Note that the plurality of drive means are not limited to those shown in the above embodiments, and each drive means does not have to be two vehicles (y, z vehicles).

In addition, although FIG. 4 shows the case where the convex lens is moved,
A concave lens may be used instead of a convex lens, and a combination of a plurality of optical elements may be moved.

Explanation of Effect> As explained above, in the present invention, a plurality of driving means are selectively operated depending on the magnitude and frequency of the image pre-signal to control the position of the subject image on the imaging surface of the photoelectric conversion element. As a result, the following effects can be obtained.

■) Compared to correcting image blur using a single driving means,
When suppressed, the size and frequency range of image blur becomes wider.

2) Since the responsibility range of each drive means is shared, the load on each drive means is reduced, design becomes easier, and miniaturization and lower power consumption can be achieved.

3) In the case of a high-frequency, small-amplitude drive means, the amount of correction for image blurring can be small, so it is possible to transform a part of the lens system, which has traditionally been difficult to use due to deterioration of optical residue.
A method can be used in which the apex angle of the prism or the position of the photoelectric variable sensor f is made variable, and rotation is used to suppress image blurring at high frequencies.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a sectional view of the embodiment, Fig. 3 is a perspective view showing a part of the embodiment, and Fig. 4 (A) is a diagram showing another embodiment of the embodiment. 4(B) is a sectional view, FIG. 5 is a waveform diagram of the pre-signal, FIG. 6 is a perspective view showing a modified example of the main part, and FIG. 7 is a separate view of the main part. In a perspective view showing a modified example, 8 b' is an image movement detection circuit, 11 is a second driving means, 12 is a first driving means, and 13 is a third driving means.

Claims (3)

[Claims] (1) Different driving means for causing relative movement between the imaging means and the subject image formed thereon, and motion detection means for detecting the relative movement between the imaging means and the subject image. 2. A vibration-proof imaging device comprising means for selectively or synchronously driving and controlling the driving means based on the output of the motion detecting means, and preventing blurring of an image of the imaging means. (2) The anti-vibration imaging device according to claim 1, wherein the selection means selects the driving means according to the frequency of the relative motion detected by the motion detection means. (3) The anti-vibration imaging device according to claim 1, wherein one of the driving means achieves high-frequency, small-amplitude driving, and another one achieves lower-frequency, large-amplitude driving. .