JPH04158342A - Hand drift preventing camera - Google Patents

Abstract

PURPOSE:To obtain a correct drift detection signal and prevent a photographing miss due to a hand drift by removing the vibration other than the hand drift of a camera, i.e., the vibration by a mirror, a diaphragm and a shutter in particular. CONSTITUTION:The vibration of a camera due to a hand drift is detected by a sensor 21, the output is sent to an arithmetic circuit 31, the DC component and high-frequency component of the unnecessary component other than the drift signal are removed from the signal component by a HPF and a LPF, then it is amplified to the necessary level by an amplifying circuit 32. One of the elements determining the amplification ratio of the amplifying circuit 32 is a sensor 22, a pressure-sensitive conducting member changing the resistance value with the degree of a shock is used for the sensor 22, and it is arranged at the stopper position of a mirror 3 in a camera main body. A drive control circuit 33 receives the output of the amplifying circuit 32 and performs various conversion and signal processing based on the drift information of a sensor 21, and it sends the signal to drive a correcting system in the drift offset direction, the acceleration control signal of the shutter speed to reduce the effect of the drift, and the warning signal to various portions. A photographing miss is prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an anti-shake camera, more specifically, to an anti-shake camera that effectively removes signals other than camera shake, that is, noise, in a shake signal processing device that detects camera shake. Regarding the camera.

[Prior Art] Conventionally, camera shake is detected by a first detection means such as an acceleration sensor or an angular velocity sensor, and a shake correction mechanism is operated based on this detection signal to reduce the influence of camera shake on the image plane. Cameras with as few numbers as possible are known. In this case, an acceleration sensor, an angular velocity sensor, etc. are used to detect camera shake, but camera shake is a fairly small movement, for example, less than 0.05 [deg] in rotation angle due to shake. Therefore, the first detection means for detecting blur is required to have high detection ability and accuracy.

However, since these shake detection means are built into the camera, they also detect vibrations caused by actuator operation inside the camera and vibrations (shocks) caused by the up and down of the mirror.
It is detected because of its good performance. Therefore, even if there is no actual camera shake, the pre-detection means may mistakenly detect the aforementioned unnecessary vibration (noise) as a camera shake signal.
If the signal from this pre-detection means is used to operate a manual pre-correction mechanism or the like, an erroneous movement deviates from the original purpose will occur. If pre-correction is performed due to this noise, there is a problem in that even if there is no actual camera shake, a photograph may be taken that looks like a pre-shake has occurred.

In order to solve this problem, Japanese Patent Application Laid-Open No. 1-300221 proposes a frequency range of 1 to 12 [Hz], which is generally said to be the frequency of camera shake.
In order to distinguish between this region and mechanical noise that is unnecessary vibration of the camera, that is, a region with a frequency of several tens of Hz or more, a frequency screening circuit is used to identify the frequency of vibration,
If a signal with a frequency other than hand vibration is detected, mechanical noise is electrically removed. in particular,
Changes are being made to the cutoff frequency of the low-pass filter to remove high-frequency components, and the signal amplification factor.

[Problem to be solved by the invention] When considering vibrations other than camera shake, there are shocks caused by the up and down of the mirror during shooting, shocks caused by the movement of the shutter curtain, and actuators that occur when winding the film or extending the lens. For example, vibration caused by There are several possibilities as mentioned above, but in the case of a silver halide camera, the only time the pre-effects actually affect the photograph is during exposure, so it is necessary to deal with vibrations other than camera shake that occur immediately before and during exposure. There is. Among the above-mentioned situations, there are particularly mentioned the times when the mirror is raised and when the front curtain of the shutter is running. These impact the terminal end at high speed (for a short period of time) and with a considerable amount of force, resulting in a strong impact.

However, when attempting to deal with the above-mentioned problem by applying the means disclosed in the above-mentioned conventional example (Japanese Unexamined Patent Publication No. 1-300221), the following problems arise. it is,
In the conventional example, abnormal vibrations are detected based on the frequency of the signal detected from the pre-detection means, so detection is required for at least 1/2 period of the signal. Furthermore, the values of some members and elements must be changed or selected based on this judgment, which inevitably causes a "delay."

As mentioned above, when the mirror is raised or when the front curtain of the shutter is running, the time is very short, so it is difficult to deal with this problem accurately and it is not possible to remove noise sufficiently.

Therefore, the present invention was made in view of the above-mentioned problems.
Eliminates vibrations other than camera shake, especially vibrations that occur immediately before and during exposure, such as vibrations caused by mirrors, apertures, shutters, etc. that operate with the release operation, thereby obtaining accurate pre-detection signals and eliminating vibrations caused by camera shake. To provide an anti-shake camera which prevents photographing errors.

[Means and effects for solving the problem] The anti-shake camera of the present invention includes a first detection means for detecting vibration of the camera due to camera shake, and a method for canceling the vibration caused by the camera shake based on the output of the first detection means. and a drive control circuit for moving an optical system within the camera, the second detection means is disposed near the end of operation of the moving member accompanying the release operation, and detects vibrations caused by the moving member; The present invention is characterized by comprising a signal processing circuit that is inserted between the first detection means and the drive control circuit and controls the output of the first detection means in accordance with the output of the second detection means. .

[Example] The present invention will be explained below with reference to illustrated embodiments.

First, prior to a detailed explanation of the present invention, the second and third
The configuration of a camera to which the present invention is applied will be explained with reference to the drawings.

FIG. 2 is a longitudinal cross-sectional view of a camera to which the present invention is applied, and FIG. 3 is a view from the rear of the camera body with the back cover removed. In the figure, reference numeral 1 is a photographic lens, 2 is a finder, 3 is a mirror, 4 is a shutter, 5 is a shutter drive unit consisting of a solenoid for driving the shutter 4, etc., 6 is a film surface, and 7 is a cartridge. 8 is a DX contact, 9 is a sprocket, 10 is a spool, 11 is a shirt button, 12 is a correction optical system, 13 is a drive member such as an ultrasonic motor, and 14 is a drive control circuit. Further, 21a, 21b, 21c, and 21d are first detection means for detecting vibration of the camera due to camera shake, respectively;
21a and 21b, 21c and 21d are the sensitivity axes (X
They are arranged so that the rotation axis (axis rotation, Y axis rotation) are the same, and are used in pairs.

And each of these detection means 21a, 21b.

21c and 21d are collectively referred to as the first detection means 21.

Reference numerals 22 and 23 denote a second detection means, which is disposed near the end of the operation of a moving member such as a mirror, shutter, etc. that accompanies the release operation, and detects vibrations caused by this moving member. When the mirror 3 flips up as shown by the arrow in FIG.
2 and is arranged so that the impact generated at that time is absorbed. Further, the other second detection means 23
is arranged so that when the shutter front curtain of the shutter 4 travels in the direction of the arrow in FIG. 3, it collides with the second detection means 23 and the impact generated at that time is absorbed.

The first detection means 21a, 21b, 21c, and 21d are means for detecting camera shake, and use a known acceleration sensor, angular velocity sensor, or the like. In reality, velocity or displacement information is obtained by integrating the output signals of these sensors once or twice.

Then, by adding the focal length, sensor mounting distance, and sensor sensitivity information to these speed and displacement information, the moving speed and amount of displacement on the image plane due to camera shake are calculated. These principles are explained in detail in Japanese Patent Application No. 1-118395 "Camera Pre-Detection Apparatus" previously filed by the present applicant, so the explanation thereof will be omitted here. The above is an overview of the configuration of the camera to which the present invention is applied. Next, an example will be explained.

FIG. 1 is a block diagram of an anti-shake camera showing a first embodiment of the present invention, and the first detection means 21 is a sensor for detecting vibration of the camera due to camera shake, as described above. The output of the first detection means 21 is sent to an arithmetic circuit 31, which removes unnecessary components other than the pre-signal, such as DC signal components and high frequency components, from the signal components detected by the sensor. As a specific means for this purpose, use of a known bypass filter, low-pass filter, etc. can be considered. The output of this arithmetic circuit 31 is sent to an amplifier circuit 32 and amplified to a required signal level.

The arithmetic circuit 31 and the amplifier circuit 32 constitute a signal processing circuit 30 that controls the output of the first detection means 21 according to the output of the second detection means 22.

Among the elements that determine the amplification degree Av of the amplifier circuit 32, one is the second detection means 22, which uses a pressure-sensitive conductive member whose resistance value changes depending on the degree of pressure (shock) it receives. This second detection means 22 detects when the mirror 3 in the camera body is raised immediately before photographing.
It is located at a position that acts as a stopper.

The output of the amplifier circuit 32 is sent to a drive control circuit 33 that moves the optical system within the camera in a direction that cancels vibrations caused by camera shake. In this drive control circuit 33, the first detection means 21
Based on the pre-information detected by the camera, various conversions and signal processing are performed, and signals are output to each related part.

This signal is, for example, a signal for operating the pre-compensation mechanism of the camera (not shown) in the direction of canceling the pre, a control signal for increasing the shutter speed in order to minimize the influence of the pre, and a signal for controlling the pre-compensation mechanism to cancel the pre. Used for warning signals, etc.

The operation of this embodiment configured in this way will be described next. Normally, when trying to take a picture, one holds the camera body, but camera shake may occur at that time. In particular, this effect is considered to be large when the focal length of the lens used is long and when the shutter speed is slow. Therefore, in order to eliminate the influence of this camera shake as much as possible, the above-mentioned processing is performed, and the information on which it is based is transmitted to the first detection means 2.
I got it from 1. When actually taking pictures, the photographer first holds the camera body and uses the viewfinder 2 (second,
(See Figure 3) and press the shirt button 11 to take a picture.

On the camera body side, when the shirt button 11 is pressed,
First, the mirror 3 is raised in the direction of the arrow in Fig. 2 above,
When this operation is completed, the front curtain of the shutter 4 moves in the direction of the arrow in FIG. 2, and the film surface 6 is exposed for the first time. When a predetermined time determined by the shutter speed has elapsed, the rear curtain of the shutter 4 moves in the same direction, and the mirror 3 returns to the predetermined position (FIG. 2), completing the photographing.

By the way, there is no problem if the vibration received by the first detection means 21 is purely camera shake from before to after shooting, but in reality, it occurs when the mirror 3 is raised just before shooting and when the front curtain of the shutter 4 When the operation is stopped during driving, an impact is generated, and this is transmitted to the first detection means 21 in the same way as a normal hand shake, or the first detection means 21
resonates itself. Therefore, in the present invention, a second detection means 22 made of a pressure-sensitive conductive member is arranged as shown in FIG. 2 at the shock absorbing part when the mirror 3 is raised and stopped immediately before photographing.

The pressure (impact)-resistance characteristics of this type of pressure-sensitive conductive member are shown in FIG. 4, and the pressure response characteristics are shown in FIG. 5, respectively. As is clear from these figures, the pressure (shock) F is
When it is not applied to the detection means 22, that is, when the mirror 3 is not raised, the resistance value R is large, and conversely, the pressure F is large.
There is a characteristic that the resistance value R becomes small when the mirror 3 is raised, that is, when the mirror 3 is raised.

The effects of this embodiment configured and operated in this manner will be described in the sixth section.
This will be explained below using figures. FIG. 6 is a circuit diagram of the amplifier circuit 32 and second detection means 22 shown in FIG.
1, a fixed resistor R1°R2, Rs, and a variable resistor R4 are connected as shown in the figure. In the present invention, as described above, camera shake is detected by the first detection means 21 and amplified to a predetermined level, and the variable resistor R4 is the pressure-sensitive conductive member of the second detection means 22. . As shown in FIG. 4 above, the characteristics of this pressure-sensitive conductive member are that its resistance value R is "large" when there is no unnecessary vibration such as pressure (shock) before photographing.
A predetermined amplification degree Av is obtained. However, when photographing, the pressure (impact) caused by the mirror 3 being raised is applied to the second detection means 22.
Therefore, the resistance value R becomes "small" and becomes smaller than the predetermined amplification degree Av.

By the way, since the first detection means 21 that detects camera shake detects the shock generated when the mirror 3 is raised as vibration as well as normal camera shake, it is necessary to eliminate this part as much as possible. Therefore, the amplification degree A
It is desirable that v becomes temporarily low when the mirror 3 is raised. Normally, the mirror 3 of the -eye reflex camera is pulled by a spring and is in a state as shown in FIG. It takes shape.

An impact occurs on this contact portion only when the mirror 3 collides with it, but after that it is considered that a relatively weak constant force is applied.

In FIG. 6, the signal amplification degree Av is R1.

It is determined by R2 and the changed resistance value of the second detection means 22, but since the impact received by the second detection means 22 when the mirror 3 is raised is almost constant, measure this in advance and adjust accordingly. Determine the values of R1°R2. By this, the desired normal signal amplification degree A v 1 is
Also, the amplification degree A when removing unnecessary vibration when the mirror 3 is raised is
V 2 can be determined respectively.

What has been described above is related to the time when the mirror 3 in FIG. , the shutter 4 in FIG. 3 can be considered. Therefore, an example using the second detection means 23 that detects and absorbs the impact when the front curtain of the shutter 4 operates in the direction of the arrow in FIG. 3 will be described below as a modification of the first embodiment. explain. This second detection means 23 is also arranged near the operating range of the front curtain of the shutter 4 in order to function in the same manner as the second detection means 22 described above.

A block diagram including the mirror 3 described above is shown in FIG. 7, and the amplifier circuit 32. The circuit diagrams of the second detection means 22 and 23 are shown in FIG. 8, respectively. In FIG. 7.8, the same components as in FIGS. 1 and 6 are given the same reference numerals and their explanations will be omitted. Further, it goes without saying that the effects obtained by this configuration are similar to those of FIG. 6 above.

Furthermore, although this embodiment is based on the assumption that an impact is detected when the mirror 3 is raised, this embodiment is not limited to this, and the present embodiment is not limited to this. Even in a camera without a mirror 3, the second detection means 2 is located near the operating range of the shutter blade.
By arranging 3, the same effect as described above can be obtained.

FIG. 9 is a block configuration diagram of an anti-shake camera showing a second embodiment of the present invention. When the vibration of a moving member such as a mirror accompanying a release operation is detected by the second detection means, in the first embodiment, the vibration is amplified. Whereas the amplification degree of the circuit 32 was changed, in this second embodiment, the low-pass filter (hereinafter referred to as L) of the arithmetic circuit 31 was changed.

(abbreviated as P, F, )), thereby removing unnecessary high frequency components other than the pre-signal from among the signal components detected by the first detection means 21. There is.

Since there is no difference from the first embodiment except for this point, the same constituent members are denoted by the same reference numerals and the explanation thereof will be omitted, and only the filter portion will be explained below with reference to FIGS. 10 to 12.

Figure 10 is a circuit diagram of the well-known glue P, F.
Operational amplifier A11, fixed resistor R1□, and variable resistor R1
2 and a capacitor C1□ are connected as shown in the figure, and its frequency characteristics are as shown in FIG. Now, if the symbols of resistors, capacitors, etc. also represent their constant values, L, P.

The cutoff frequency f of F. ■ is f, 1-1/2π (R1□+R12) C11...
... is given by (1). Therefore, the movement of the mirror 3 in FIG. 2 is linked to the movement of the sliding piece of the variable resistor R1°. If the resistance value of the variable resistor R12 is made small, and the resistance value of the variable resistor R12 is made large only during exposure when the mirror 3 moves up and collides with the second detection means 22a, P.

The cutoff frequency of F is high during normal times and low during exposure. Therefore, high frequency components such as impact and resonance during exposure when the mirror 3 collides with the second detection means 22a can be removed more efficiently than in normal times when the mirror 3 is not up.

In other words, the cutoff frequency F is changed only when an impact or resonance is occurring, especially when an impact occurs.

If unnecessary vibrations such as resonance are not occurring, the phase shift of the signal can be kept small, and more accurate preliminary information can be obtained.

Next, a means for linking the movement of the mirror 3 to the movement of the sliding piece of the variable resistor R1□ will be explained with reference to FIG.

In FIG. 12, a second detection means 22a having a movable part surrounded by a broken line and a restraining spring 24 biased to push down the second detection means 22a in the figure are shown in FIG. is added. The second detection means 22a is arranged at the same position as the second detection means 22 in FIG. 2, and when the mirror 3 is not raised, the sliding piece of the variable resistor R1□ Since it is in the position shown in FIG. 12, the resistance value of variable resistor R12 is approximately zero.

On the other hand, during exposure when the mirror 3 is up, the second detection means 22a is moved upwardly against the restraining spring 24 in the direction of the arrow in FIG.
The sliding piece No. 2 moves upward in the figure, and its resistance value increases. The reason why the restraining spring 24 is necessary will be explained below.

In Fig. 2.12, during actual exposure, the mirror 3 is fixed in an upright position and is always in contact with the second detection means 22a, but even after unnecessary vibrations such as shock and resonance have subsided, the mirror 3 There may be cases where it does not become 0. Considering such a case, the second detection means 2 in FIG.
A restraining spring 24 is arranged so as to restrain the movable part (broken line part) of 2a, and the above-mentioned problems can be solved. In other words, the mirror 3 is raised for exposure, and the second detection means 2
2a, at that moment the detection means 22g is moved in the direction of the arrow in FIG. 12, and R12 becomes "large".
becomes. After that, because of the restraining spring 24, the second detection means 22a is pushed back and becomes R2-0. This results in
The cutoff frequency f of the low-pass filter can be changed only at the moment when the mirror 3 is raised.

In P and F, since the resistance value of the variable resistor R1° is zero during normal times except during exposure,
The cutoff frequency f at this time. 2 becomes f-1/2πR11C11 (2). On the other hand, the mirror 3 is raised and the second detection means 22a
At the time of exposure when the light collides with
l is as shown in equation (1) above. Here, the cutoff frequencies fcl and f. 2, fcl<fc2, and thereby unnecessary high frequency components other than the pre-signal can be removed from the signal components detected by the first detection means 21.

FIG. 13 is a block diagram of an anti-shake camera showing a third embodiment of the present invention. In this third embodiment, the amplification factor of the amplifier circuit 32 is changed when the mirror is raised. function, and the glue inside the arithmetic circuit 31, P,
It also has the function of the second embodiment described above, in which the cutoff frequency of F is changed. Therefore, the same constituent members as in each of the above embodiments are given the same reference numerals and their explanations are omitted, and only the sliding portion of the variable resistor R12 when the mirror 3 flips up will be explained with reference to FIG. 14. By also arranging the second detection means 22 described in the first embodiment above in the part of the second detection means 22a shown in FIG. It becomes possible to change 32 signal amplification degrees Av at the same time.

FIG. 15 is a block diagram of a modification of the third embodiment. According to this modification, an efficient low-pass filter is constructed by taking into account the impact and resonance caused by the operation of the mirror 3 and shutter 4. It becomes possible to change the cutoff frequency f and the amplification degree Av of the signal amplification circuit at the same time.

As detailed above, according to each of the above embodiments, vibrations (shocks) other than the camera's front movement are detected, particularly when the mirror is raised immediately before exposure and during exposure, and when the front curtain of the shutter is running. However, by using an element in the signal processing circuit whose value changes instantaneously according to the degree of shock detection, it is possible to change the cutoff frequency of the filter or change the amplification factor of the signal amplification circuit during signal processing. It becomes possible to remove unnecessary vibrations and obtain accurate pre-detection signals in real time. In this case: (1) It is possible to change the amplification degree in real time and remove abnormal signals.

(2) Accurate control is possible depending on the degree of impact.

(3) Conventionally used rubber by utilizing a pressure-sensitive conductive member as a mirror-up shock absorbing member.

It is possible to replace sponges, etc.

[Effects of the Invention] As described above, according to the present invention, the second detection means detects vibrations of movable members such as mirrors, apertures, shutters, etc. that operate with the release operation, and this output detects the vibrations of the camera due to camera shake. Since the output of the first detection means for detecting the vibration of the first detection means is controlled, unnecessary high frequency components other than the pre-signal can be removed from the signal components detected by the first detection means. A remarkable effect is achieved.

[Brief explanation of the drawing]

FIG. 1 is a block configuration diagram of an anti-shake camera according to a first embodiment of the present invention, FIG. 2 is a vertical sectional view of an anti-shake camera according to the present invention, and FIG. 3 is a camera shown in FIG. 2 above. 4 and 5 are diagrams showing the pressure-resistance characteristics and pressure response characteristics of the pressure-sensitive conductive member, respectively. FIG. 7 is a block diagram of a modified example of the first embodiment, and FIG. 8 is a circuit diagram of the amplifier circuit and second detection means in FIG. 7. 9 is a block configuration diagram of an anti-shake camera showing a second embodiment of the present invention, and FIGS. 10 and 11 are circuit diagrams and frequency characteristics of gates P and F in the arithmetic circuit in FIG. 9 above. Figure 12 shows the connections in the arithmetic circuit in Figure 9 above, P, F.
, and a second detection means, FIG. 13 is a block diagram of an anti-shake camera showing a third embodiment of the present invention, and FIG. FIG. 15 is a block diagram of a modification of the third embodiment. 3・・・・・・・・・・・・Mirror (moving member) 4.
・・・・・・・・・Shutter (〃)21・・・・・・
...First detection means 22, 22a, 23, 23a...Second detection means 30...Signal processing circuit 33...Drive control Circuit No. 40 Pressure F Gloss 0 Yu No. 50 No. 60' No. 120 No. 13

Claims (1)

[Claims] (1) A camera equipped with a first detection means for detecting vibration of the camera due to camera shake, and a drive control circuit that moves an optical system within the camera in a direction to cancel the vibration due to the camera shake based on the output of the first detection means. A second detection means is disposed near the end of the operation of the moving member associated with the release operation and detects vibrations caused by the moving member, and is interposed between the first detection means and the drive control circuit, and An anti-shake camera comprising: a signal processing circuit that controls the output of the first detection means in accordance with the output of the second detection means.