JP2801175B2 - Image blur prevention device for camera - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001] This invention is relates to an image blur prevention equipment that is applied to a camera or the like.

[0002]

2. Description of the Related Art There has been a high demand for improvement of image deterioration due to camera shake in a photographing apparatus, and efforts have been made to eliminate camera shake. For example, a method has been proposed in which a camera shake is detected and an image is shifted by shifting a lens in the liquid to remove the image blur.
No. 60-143330 discloses changing the angle of a mirror,
There has been proposed a method of shifting a photographed image by switching an actually used area among photographing areas of a CD imaging device.

FIG. 4 shows a conventional example of such a photographing apparatus with an image blur prevention device. In FIG. 4, reference numeral 1 denotes an angular acceleration sensor which detects angular acceleration in a rotation direction about an axis orthogonal to the paper surface. Reference numeral 2 denotes an integration circuit which converts the angular acceleration detected by 1 into a speed. 7 is a differentiator, 6 and 8 are subtractors, and 9 is a potentiometer.

The potentiometer 9 is configured to output 0 at the center position and output a voltage in accordance with the position of the lens moving up and down on the plane of the drawing in conjunction with the movement of the lens 13 as a correction optical system. 12 is a spring,
A force is applied to the photographing lens 13 in the direction of the center thereof. When the coil 10 described later is not energized, the lens 13 stops at the center of the substantially movable range where the spring force and its own weight balance. The image can be shifted by shifting the photographing lens 13.

[0005] Reference numeral 10 denotes a coil, and 11 denotes a magnet bonded to a lens. 18 is an analog switch,
The switching is performed by a lens control signal 20 (not shown). When an electric current is applied to the coil 10, the magnet 11 receives a force and resists the force in the center direction by the spring 12, and the lens can be driven in the vertical direction, and the lens 12, the coil 10, the magnet 11, and the magnet 11
, A potentiometer 9 that slides in conjunction with
The differentiator 7 is configured so as to be able to perform feedback control based on the shake speed as a whole, and constitutes a speed input actuator 19.

When a + (plus) voltage is input to the + input terminal of the subtractor 6, the lens moves upward on the paper at a speed corresponding to the voltage, and the-(minus) voltage is reduced. When it is input, it is similarly configured to move downward. Reference numeral 18 denotes an analog switch. Reference numeral 20 denotes a lens position control signal connected to a control CPU of a known camera (not shown). The signal is output at a timing described later.

Next, the operation of such an image blur prevention device will be described.

First, the user holds the camera with his / her hand, points the camera at the first object to be photographed, and presses a shutter release button of the camera (not shown) to turn on the power of each part of the camera, and the lens position control signal from the signal line 20 is The analog switch 18 is connected so that the camera shake angular velocity signal output from the integrator 2 is input to the lens speed control actuator 19, and the image blur prevention is activated. Therefore, in this image blur prevention state, the image can be apparently stopped by driving the lens in accordance with the angular velocity of the camera shake, and the image viewed from the viewfinder appears to be still.

Next, when actually taking a picture, the lens position control signal is set to a low level immediately before the shutter operation starts. Then, the analog switch 18 connects the output of the subtractor 8 and the + input of the subtractor 6. At this time, the polarity of the lens position signal detected by the potentiometer 9 is inverted by the subtractor 8 and connected to the speed input actuator 19, so that feedback control based on the lens position is performed. As a result, the lens is drawn to the point where the lens position signal becomes 0, that is, the center position, and is brought into a stationary state. In other words, the lens position control signal can be said to be a lens centering signal.

When the lens position control signal 20 goes high again, the lens starts to move again to the image blur prevention state, and a known shutter operation is performed, so that photographing can be performed in the image blur prevention state. .

FIG. 5 shows the relationship between the position of the lens 13 and the lens position control signal 20 in the conventional example.

In the above description, the image blur preventing apparatus against the blur in the rotational direction about the axis perpendicular to the plane of the paper has been described. However, the shake in the rotational direction about the axis perpendicular to the optical axis and parallel to the paper is described. Needless to say, an image blur prevention device having a similar configuration is provided for the device.

[0013]

[0014]

In the above-mentioned conventional example,
Image blur prevention operation characteristics and release before the release button is pressed
The relationship between the image blur prevention operation characteristics after the release button is pressed
Before the shutter release is performed.
Perform image blur prevention operation appropriate for each subsequent situation
Could not .

The present invention has been made in view of the circumstances described above.
This is the best image for the usage of the camera.
Image stabilization for cameras capable of anti-shake operation
It is intended to provide a stop device .

[0016]

SUMMARY OF THE INVENTION The present invention achieves the above objects.
In order to achieve, according to the operation of the release member of the camera,
From the state in which the image blur prevention means operates with the first operation characteristic,
Operate with a second operation characteristic different from the first operation characteristic.
Image blur prevention device having variable means for changing the state to
Is what you do .

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) FIG. 1 shows a first embodiment of the present invention, and the same members as those in the conventional example are denoted by the same reference numerals.

Reference numerals 21, 22, and 23 denote analog switches, 2
4 and 25 are diodes, 26 is a NOR circuit, 27 and 28
Is a comparator, 29 is an operation AMP, 30, 31, 33,
Reference numerals 34, 35 and 36 denote resistors, and reference numeral 32 denotes an analog switch, which is switched by a drive range setting signal 37 from a control CPU (not shown). In FIG. 1, a block surrounded by a chain line constitutes a correction optical system control unit 38, and the movable range of the correction optical system is automatically selected by the control unit 38.

Next, the operation of the correction optical system control means 38 and other parts will be described.

The resistors 33 and 34 are divided by an output voltage + D by a voltage dividing circuit.
₁ is output, and the resistors 35 and 36 output the output voltage + D
It is configured to output ₂ . And this output +
D ₁ and + D ₂ corresponds to the limit width of the driving ranges of the correction optical system, when the drive range setting signal 37 by the analog switch 32 is at the high level becomes a limiting width drive limiting V ± D _1, at the low level Are configured to have a limited width of ± D ₂ .

The output of the analog switch 32 is inverted by an inverting amplifier composed of resistors 30 and 31 and an operational amplifier 29, becomes -D ₁ (or -D ₂ ), and is input to the + input of the comparator 27. , Comparator 2
8 is inputted as + D ₁ (or + D ₂ ) to the − input. The output of the potentiometer 9, that is, the lens position signal, is input to the minus input of the comparator 27 and the plus input of the comparator 28.

Therefore, if the position of the lens is x, x> D
_{When the} lens is in the range of ₁ (or x> D ₂ ), the output of the comparator 28 is high, and otherwise the output of the comparator 28 is low.

The output of the comparator 27 becomes high at the lens position where x <-D ₁ (or x <-D ₂ ), and outputs low at other positions. NOR circuit 2
6 is connected to comparators 27 and 28, and −D ₁ <x
The output is high only in the range of <D ₁ (or -D ₂ <x <D ₂ ), otherwise it is low.

The analog switches 21, 22, and 23 are turned on when a high signal is input. Accordingly, the relationship of the analog switches with respect to the lens position is as shown in Table 1 below.

[0025]

[Table 1]

The analog switch 21 includes a diode 24
And the lens position x is x <−D ₁ (x <−
In the case of ON in D ₂ ), driving is performed only when the camera shake speed signal output from the integrator 2 is + (that is, when camera shake occurs in the direction of moving the lens in the + direction).

The analog switch 22 includes a diode 25
And is turned on when D ₁ <x (D ₂ <x),
A drive signal is transmitted to the actuator 19 only at a camera shake speed at which the lens is moved in one direction.

The analog switch 23 has a lens connected to -D
_{When 1} <x <D ₁ (−D ₂ <x <D ₂ ), the integrator 2 is connected to the actuator 19 so that the actuator 19 performs an image blur prevention operation.

Therefore, the movable range of the lens 13 (that is, the correction optical system) is substantially limited to ± D ₁ (± D ₂ ), and either the movable range ± D ₁ or ± D ₂ is set to the above range. Is selected by the control means.

FIG. 2 is a diagram showing the operation of the correction optical system controlled by the control means 38.

The operation of the camera according to the present embodiment will be described below with reference to FIGS.

When the camera user holds the camera during photographing and presses a shutter release button (not shown), a first switch (not shown) corresponding to a first stroke of the button is turned on, and the power of the camera (not shown) is turned on. State
The drive range setting signal 37 from the controller CPU of the camera (not shown) is in a high state. In this state, the image blur prevention device is activated. The lens driving range is ± D _1, image blur prevention apparatus performs only image stabilization when the movement of the lens is in the range of ± D _1.

Next, when the camera user further depresses the shutter release button, a second switch (not shown) closes,
As a result, the drive range setting signal 37 becomes low, the driving range is a range of ± D ₂ (D _2> D ₁₎ and the opening of the shutter is performed photographed in this state is performed.

That is, in the camera of the present embodiment, it is not necessary to perform a reset operation for adjusting the center of the correction optical system to the center of the photographing optical system immediately before photographing, so that the photographing can be performed quickly. Further, even when the correction optical system has reached the limit of the first movable range as shown in FIG. 2, the correction lens can be driven in all directions at the time of photographing.

(Second Embodiment) FIG. 3 shows a second embodiment of the present invention.
In FIG. 3, the components denoted by the same reference numerals as those in FIG. 1 are the same as the components shown in FIG.

In FIG. 3, analog switches 39 and 40 are connected to a NOT circuit 41 and an OR circuit 42, respectively, and are turned on when a high level is input. 43
And 44, a resistor; and 45, an operational amplifier.

From the above, the operation of the analog switches 39 and 40 with respect to the lens position is as shown in Table 2 below. Note that the lens position is x.

[0038]

[Table 2]

In the embodiment shown in FIG. 3, when the lens position x is within -D ₁ <x <D ₁ , the output of the integrator 2 is connected to the actuator 19 through an analog switch to prevent image blur. Is activated, but the lens ± D ₁ (±
If the value exceeds the range of D ₂ ), the analog switch 39
Is turned off, and the analog switch 40 is turned on.
Then, the lens position signal generated by the potentiometer 9 is inverted by an inverting amplifier including the resistors 44 and 43 and the operational amplifier 46, and is input to the actuator 19. This is a force that pulls back around the lens. As a result, the driving range of the lens is ± D ₁ (or ± D
₂ ) Limited to:

In normal single shot shooting,
The operation of the second embodiment is almost the same as the operation of the first embodiment, and operates at the timing shown in FIG.

The second embodiment differs greatly from the first embodiment in the case where the drive limit of the image blur prevention device is changed from ± D ₂ to ± D ₁ , particularly after the photographing is completed. That, in the first embodiment, when the lens was in out of the driving range of ± D ₁ immediately after switching, when the driving signal of the anti-image blur for camera shake, trying to move the center direction in the lens only to drive the lens, while moving relatively slowly driving range of ± D ₁ while performing anti image blur, the second embodiment switches the driving range of ± D ₂ to ± D _1, quickly in that moving the lens to within ± D ₁ is a first embodiment and said.

(Correspondence between the Invention and the Embodiment) The controller CPU (not shown) that outputs the drive range setting signal 37 in the above embodiment corresponds to the variable means of the present invention.

[0043]

As described above, according to the present invention,
An optimum image blur prevention operation according to the situation can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram of an electric circuit according to a first embodiment of the present invention.

FIG. 2 is an operation explanatory view of the embodiment of FIG. 1;

FIG. 3 is a block diagram of an electric circuit according to a second embodiment of the present invention.

FIG. 4 is a block diagram of an electric circuit showing a schematic configuration of a conventional photographing apparatus.

FIG. 5 is a view for explaining the operation of the conventional example of FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Angular acceleration sensor 2 ... Integration circuit 6 ... Subtractor 7 ... Differentiator 8 ... Subtractor 9 ... Potentiometer 10 ... Coil 11 ... Magnet 12 ... Spring 13 ... Lens (correction optical system) 21-23 ... Analog switch 24 , 25 ... diode 32 ... analog switch 39, 40 ... analog switch 38 ... correction optical system control means

──────────────────────────────────────────────────続 き Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G03B 5/00 G03B 17/00

Claims (1)

(57) [Claims] 1. According to an operation of a release member of a camera,
From the state in which the image blur prevention means operates with the first operation characteristic ,
Operate with a second operation characteristic different from the first operation characteristic.
An image blur prevention device for a camera, comprising a variable means for changing a state of the image to a predetermined state.