JPH07253605A - Image blurring preventing device for optical device - Google Patents

Abstract

PURPOSE:To provide a new image blurring preventing device capable of preventing the image blurring by the vibration of a subject to be observed, or the vibration of an object itself. CONSTITUTION:As for the image blurring preventing device, the image blurring on an image pickup element 5 is prevented by detecting the movement of a line of sight by an observer 100 by a means for detecting the line of sight (constituted of a light source 104, a lens 106, half mirrors 105 and 105', a lens 107, an image sensor 109 and a line of sight detection circuit 10) installed on an observation optical system for the optical device, by detecting the shake and vibration of the subject to be observed based on the outputted signal so as to calculate the correction driving quantity of an image blurring correcting lens 3 for a master optical system by a vibration correcting means control circuit 11, thereafter, by driving an actuator 3a through an actuator driving circuit 12 so as to move the lens 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image blur preventing device for use with an optical device such as an observing device or a photographing device.

[0002]

2. Description of the Related Art Recently, in image pickup apparatuses such as video cameras and still cameras, image blur prevention technology has been put into practical use for preventing image blur caused by the shake of the apparatus at the time of photographing. Video cameras having functions are also commercially available.

There are several known image blur prevention techniques, and there is a system using an angular acceleration sensor as a detecting means for detecting the blur of the photographing apparatus.

An image blur prevention apparatus of this type fixes an angular accelerometer (for example, a vibration gyro) as a blur detecting means to a photographing device, and detects the shake amount of the entire photographing device from the output of the angular accelerometer. The image blur correction unit is driven based on the detected value.

[0005]

The above-mentioned conventional example using the angular accelerometer as the shake detecting means has the following drawbacks.

Angular accelerometers (vibrating gyros) are expensive.

Since the angular accelerometer is fixed to the image pickup apparatus, it is possible to correct the image shake caused by the shake of the image pickup apparatus, but the image caused by the shake (vibration) of the subject (or the observation target) itself. The shake cannot be corrected.

The object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, to correct the image shake caused by the shake of the observation target or the subject itself, and to prevent the image shake without using a vibrating gyro. It is to provide a device.

[0009]

In order to prevent the image blur caused by the shake of the observation target or the subject itself, a detection means capable of detecting the shake of the observation target or the subject itself is required. In the present invention, the above-mentioned problem is solved by using a line-of-sight change detection unit that can detect a change in the line-of-sight direction of a user of an imaging device or the like as a detection unit that enables this.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

<Embodiment 1> With reference to FIGS. 1 and 2, a video camera equipped with an image stabilizing apparatus according to a first embodiment of the present invention will be described.

In FIG. 1, lenses 1 to 4 of the photographing optical system are shown.
Is a zoom lens consisting of 4 groups of lenses,
Reference numeral 1 is an objective lens, 2 is a variable power lens for changing the focal length, 3 is an image blur correction lens, and 4 is a focus lens for focusing. The image blur correction lens 3 can move in vertical and horizontal directions (directions orthogonal to the paper surface in the drawing) in a plane orthogonal to the optical axis, and is driven by an actuator 3a in the vertical direction and left and right directions (perpendicular to the paper surface). Direction) is driven by an actuator (not shown). An image pickup element (CCD) 5 serves as an image forming surface. The photoelectric conversion signal output from the element 5 is input to the camera signal processing circuit 5a, and the output of the circuit 5a is guided to the recorder 5b or the like. 6 is a half mirror, 7 is a mirror, 8
Is a finder optical system. Finder optical system 8
Is composed of a variable power optical system and a focus optical system, and is configured to interlock with the zooming operation and the focus operation of the photographing optical system.

Light from the subject that has passed through the objective lens 1 and the variable power lens 2 enters the eye 9 of the photographer through the finder optical system 8 and is observed.

The optical elements 104 to 109 and the line-of-sight detection circuit 1
In order to obtain the visual axis (gazing point) by projecting the light flux from the light source to the anterior segment of the eye and utilizing the corneal reflection image based on the reflected light from the cornea and the imaging position of the pupil, It constitutes the line-of-sight detection means of Japanese Patent Application Laid-Open No. 61-172552. The basic principle of the line-of-sight detecting means will be described below with reference to FIG.

In FIG. 2, reference numeral 104 denotes a light source such as a light emitting diode which emits infrared light insensitive to an observer,
It is arranged on the focal plane of the light projecting lens 106.

The infrared light emitted from the light source 104 becomes parallel light by the light projecting lens 106 and is reflected by the half mirror 105 to illuminate the cornea 101 of the eyeball 100. At this time, the corneal reflection image d based on a part of the infrared light reflected on the surface of the cornea 101 is transmitted through the half mirror 105 ′ and the light receiving lens 107.
Then, the cornea reflection image d is re-imaged at the position d ′ on the image sensor 109.

Light fluxes from the ends a and b of the iris 103 are guided onto the image sensor 109 via the half mirror 105 'and the light receiving lens 107, and their positions a'and b'.
The images of the end portions a and b are formed on. When the rotation angle θ of the optical axis a of the eyeball with respect to the optical axis a of the light receiving lens 107 is small and the Z coordinates of the ends a and b of the iris 103 are Za and Zb, the coordinate Zc of the center position c of the iris 103 is Zc≈. It is expressed as (Za + Zb) / 2.

Further, if the Z coordinate of the corneal reflection image generation position d is Zd and the distance between the center of curvature O of the cornea 101 and the center C of the iris 103 is 迣 OC, the rotation angle θ of the optical axis a of the eyeball is 迣 OC. sin θ≈Zc−Zd (1) The relational expression is approximately satisfied. Therefore, the image sensor 109
The rotation angle θ of the eyeball optical axis a can be obtained by detecting the position of each singular point (corneal reflection image d and iris edges a and b) projected above. At this time, the equation (1) can be rewritten as β · OC · sin θ≈ [(Za ′ + Zb ′) / 2] −Zd ′ (2). However, β is the generation position d of the corneal reflection image
And a distance l between the light receiving lens 107 and the distance l ₀ between the light receiving lens 107 and the image sensor 109.

By thus detecting the direction of the line of sight of the observer's eye (gazing point), it is possible to know which position on the finder surface the photographer is observing in, for example, a video camera.

A signal from the image sensor 109 enters the line-of-sight detection circuit 10 to calculate and obtain the line-of-sight direction of the photographer.
Although only the vertical line-of-sight detection means is shown in FIG.
It also has a line-of-sight detection unit (not shown) in the left-right direction (perpendicular to the paper surface).

Reference numeral 11 denotes a shake correction means control circuit, which calculates and determines the amount of displacement of the image shake correction lens 3 and drives an actuator 3a (a horizontal drive actuator is not shown) via an actuator drive circuit 12. , Shifts the image on the image plane vertically and horizontally.

The function of the image blur prevention device will be described below.

Usually, when a photographer looks at an object through a viewfinder and there is a subject (referred to as a main subject) that the photographer wants to photograph, the photographer looks at the main subject. I will chase after. If an image sway (due to the movement of the entire device or the movement of the subject itself) occurs here, the photographer follows the main subject with his / her eyes as described above. If the movement of the photographer's eyes (movement of the line of sight) can be detected, the amount and direction of the currently occurring image blur can be detected. .

In this embodiment, the line-of-sight detection circuit 10 detects the movement of the line-of-sight, and based on the detected value, the shake correction means control circuit 11
By calculating and determining the amount to drive the image blur correction lens 3 and displacing the image blur correction lens 3 via the actuator drive circuit, it is possible to remove the image blur that is currently occurring.

However, it should be noted here that the movement of the gazing point of the photographer does not always correspond to the movement of the image blur. For example, when there are a plurality of subjects (a plurality of persons) in the viewfinder screen, a phenomenon "eyes movement" occurs in each person. Similarly, when a person moves within the viewfinder screen, eye movements occur in the same way, but it is considered that the image blur information included in the movement of the line of sight of the observer is often a relatively high-frequency signal. The detection circuit 10 is provided with a filter means such as a high-pass filter, a limiter for a temporal change of the line-of-sight angle, a comparator, etc.
It is desirable to discriminate between "shaking and vibration of the subject" so as to capture the input signal.

<Other Embodiments> Another example to which the image blur prevention device of the present invention is applied is shown below. In the following example, description of the same components as those described in FIG. 1 will be omitted.

A second embodiment is shown in FIGS. 3 and 4. In this embodiment, the lens 13 of the third group is a normal variable power lens, and cannot move in the direction orthogonal to the optical axis.

In the first embodiment, the optical means is moved as the shake correction means, but in the video camera of the present embodiment, a partial image signal is selected from the effective screen of the CCD 5 as shown in FIG. Screen cutout circuit 5 for cutting out
c, and is configured to change the cutout screen position for each frame to perform image blur correction, so that a control signal for changing the screen cutout position is added to the screen cutout circuit 5c. Has become.

FIG. 5 shows a third embodiment. The third embodiment shows a case where the image blur prevention device of the present invention is applied to a video camera having an optical viewfinder 8'independent of a photographing optical system.

FIG. 6 shows a fourth embodiment. The fourth embodiment does not require the two image sensors 109 that were required in the visual axis detecting means of the above-described embodiment (the output signal of the CCD 5 is used instead of the image sensor 109.
The configuration is such that imaging and line-of-sight detection are switched for each frame). According to the configuration of the present embodiment, the cost of the image blur prevention device and the cost of the optical device can be reduced and the size can be reduced.

[0031]

As described above, according to each of the image blur prevention devices of Embodiments 1 to 4, the object to be observed which is vibrating violently is observed or photographed as an image which does not rock on the image plane. In addition, it is possible to reliably prevent the image shake due to the shake of the observation target (or the subject) which could not be prevented by the conventionally known image shake preventing apparatus. . Further, since the expensive vibration gyro which is necessary in the conventionally known image blur preventing device is not required, it is possible to realize the image blur preventing device which is less expensive than the conventional image blur preventing device.

In the embodiment of FIG. 3, since there is no mechanically driven correction lens, there is an effect that the optical device can be made smaller than that of the first embodiment.

The embodiment of FIG. 5 shows the case where the image blur prevention device of the present invention is applied to a known video camera.

In the embodiment shown in FIG. 6, the constituent elements of the image pickup system, that is, the photographing optical system and the constituent elements of the visual axis detecting means are combined, so that the visual axis detecting means can be downsized and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a video camera including an image blur prevention device according to a first embodiment of the present invention.

FIG. 2 is a diagram for explaining a function of a line-of-sight detection unit that is a constituent element of the image blur prevention device of the present invention.

FIG. 3 is a schematic configuration diagram of a video camera equipped with an image blur prevention device according to a second embodiment of the present invention.

FIG. 4 is a diagram for explaining the function of the image blur prevention device shown in FIG.

FIG. 5 is a schematic configuration diagram of a video camera having an independent viewfinder optical system including the image blur prevention device according to the first embodiment of the present invention.

FIG. 6 is a schematic configuration diagram of a video camera including an image blur prevention device according to a fourth embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Objective lens 2 ... Variable-magnification lens 3 ... Image blur correction lens 3a ... Actuator 4 ... Focus lens 5 ... Imaging device 5a ... Camera signal processing circuit 5b ... Recorder 5c ... Screen cut-out circuit 6 ... Half mirror 7 ... Mirror 8,8 '... finder optical system 9 ... observer's eye 10 ... line-of-sight detection circuit 11 ... shake correction means control circuit 12 ... actuator drive circuit 13 ... third group lens 100 ... eyeball 101 ... cornea 103 ... iris 104 ... light source 105, 105'
... Half mirror 106 ... Emitting lens 107 ... Receiving lens 109 ... Image sensor

Claims (4)

[Claims] 1. A line-of-sight detecting means for detecting a line-of-sight direction of an optical device user who is observing an object to be observed through an optical system of the optical device, and an image-forming plane of the optical device according to an output of the line-of-sight detecting means An image blur prevention device for an optical device, comprising: 2. An image forming surface of the optical device is composed of an image pickup device, and has screen cutout means for changing a screen cut out from an effective screen of the image pickup device according to an output of the line-of-sight detection means. The image blur prevention device according to claim 1, wherein 3. The image blur prevention device according to claim 1, wherein the optical device has an image pickup element, and the image pickup element also serves as an input means of the line-of-sight detection means. 4. The observation optical system of the optical device is independent of the main optical system, the observation optical system is provided with the line-of-sight detection means, and the image blur correction means is provided in the main optical system. The image blur prevention device according to claim 1, wherein