JPH0980526A - Photographing device provided with shake correction mechanism and lens device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain excellent image quality by changing and setting the maximum shake correcting time according to a focal distance to be changed and stopping the driving of a shake correction driving part after the lapse of a maximum shake correcting time from the start of a shake correction control action. SOLUTION: By a microcomputer for a shake correction control action 3, the driving of the shake correction driving part is controlled, based on the output of a microcomputer for a body 25 in a body device 2 and the positional information of an optical system from an X encoder 5, a Y encoder 9, a distance encoder 15 and a zoom encoder 22. Then, the maximum shake correcting time is changed and set according to the changing focal distance. Based on it, the driving of the shake correcting driving part is stopped after the lapse of the maximum shake correction time after from the start of the shake correction control action, regardless of the shake correction control signal of a shake correction control part. By changing the maximum shake correcting time according to the focal distance in such a way, the sufficient shake correction control action is performed to obtain the excellent image.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photographing device and a lens device having a shake correction mechanism.

[0002]

2. Description of the Related Art Conventionally, an AF mechanism has been generally used in a photographing apparatus represented by a camera, and it has been proposed to add a shake correction mechanism for correcting camera shake.

This blur correction mechanism is incorporated in a photographing device and detects angular fluctuation of the optical axis due to camera shake or the like, and corrects a photographed image by this, for example, Japanese Patent Laid-Open No. 2-6.
No. 6535 applied to a single-lens optical system, on the other hand, in Japanese Laid-Open Patent Publication No. 2-183217, a photographed image is corrected by moving a part of a photographing optical system of an internal focusing type telephoto lens. Examples are known.

[0004]

However, when the above-mentioned blur correction mechanism is applied to a lens device such as a zoom lens whose focal length of a photographing optical system can be continuously changed, the exposure control time is reduced. If the correction mechanism becomes longer than the maximum blur correction time, which is the maximum time for which the blur correction control can be performed with a predetermined accuracy, it is included in the target movement speed of the blur correction drive unit calculated based on the output of the blur correction detection unit. The amount of film exposure blur caused by the error component is larger than the amount of film exposure blur when the blur correction control is not performed.

Therefore, in such a case, since the shake correction mechanism is controlled so as not to perform the shake correction control (that is, the shake correction control is stopped), when the focal length set by the user of the photographing apparatus is large. However, even though the shake correction mechanism is provided, there is a problem in that the shake correction control cannot be performed, good image quality cannot be obtained, and the reliability of the shake correction mechanism for the user of the photographing apparatus is reduced. there were.

[0006]

In view of the above problems, the present invention changes and sets the maximum blur correction time in accordance with the changing focal length, and based on the newly set maximum blur correction time, Regardless of the shake correction control signal from the shake correction control unit, the drive of the shake correction drive unit is stopped after the maximum shake correction time has elapsed from the start of the shake correction control. In this case, even if the focal length of the photographic optical system changes, sufficient blur correction control is performed to obtain a good image quality.

According to the first aspect of the present invention, the photographing optical system and the blur of the optical axis of the photographing optical system are detected, and a part or the whole of the photographing optical system and the photographing screen are made relative to each other based on the detected blur amount. And a shake correction mechanism for moving the shake correction mechanism, the maximum shake correction time being the maximum time during which the shake correction mechanism can perform shake correction control based on the focal length of the photographing optical system. It is characterized by changing.

According to a second aspect of the present invention, there is provided a body device which is combined with a photographing optical system, a blur of an optical axis of the photographing optical system is detected, and a part or the whole of the photographing optical system is combined based on the detected blur amount. And a blur correction mechanism for relatively moving a photographing screen built in the lens device, wherein the blur correction mechanism is based on a focal length of the photographing optical system,
It is characterized in that the maximum blur correction time, which is the maximum time during which blur correction control can be performed, is changed.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) Hereinafter, the present invention will be described in more detail by way of an embodiment of the present invention with reference to the drawings.

FIG. 1 is a block diagram showing a first embodiment of a camera provided with a shake correction mechanism according to the present invention, and FIG. 3 is a schematic diagram showing the configuration of a camera provided with a shake correction mechanism in this embodiment. is there.

This blur correction mechanism is incorporated in a photographing device (see FIG. 3) composed of a lens device 1 and a body device 2, and as will be described later, a blur amount of an optical axis in a photographing optical system. A part of the photographing optical system is moved based on the detection value of. The lens device 1 includes a shake correction control microcomputer 3, an ultrasonic motor microcomputer 16, and a communication microcomputer 24.
And the like, while the body device 2 is provided with a body microcomputer 25 and the like. In this embodiment, by combining these respective microcomputers,
A control device according to the present invention is configured.

Microcomputer 3 for blur correction control
Is a microcomputer 25 for the body of the body device 2.
Of the X-axis drive motor 7, the X-axis motor driver 8, the Y-axis drive motor 11, and the Y-axis drive motor 11 based on the optical system position information from the X encoder 5, the Y encoder 9, the distance encoder 15, the zoom encoder 22, and the like. The drive of the shake correction drive unit including the shaft motor driver 12 and the like is controlled.

The lens contact 4 is a group of electrical contacts used for exchanging signals between the lens device 1 and the body device 2, and is connected to the communication microcomputer 24. The X encoder 5 is for detecting the amount of movement of the optical system in the X-axis direction, and its output is connected to the X encoder IC 6. The X encoder IC 6 is for converting the amount of movement of the optical system in the X axis direction into an electric signal, and the signal is sent to the shake correction control microcomputer 3. Further, the X-axis drive motor 7 is a drive motor for moving and driving the X-axis image stabilization optical system, and the X-axis motor driver 8 is
This is a circuit for driving the X-axis drive motor 7.

Similarly, the Y encoder 9 is for detecting the amount of movement of the optical system in the Y-axis direction, and its output is connected to the Y encoder IC 10. The Y encoder IC 10 is for converting the amount of movement of the optical system in the Y-axis direction into an electric signal, and the signal is sent to the shake correction control microcomputer 3. Further, the Y-axis drive motor 11 is a drive motor for moving and driving the Y-axis shake correction optical system, and the Y-axis motor driver 12 is a circuit for driving the Y-axis drive motor 11.

The shake correction head amplifier 13 is a circuit for detecting the shake amount, converts the image shake information into an electric signal, and the electric signal is sent to the shake correction control microcomputer 3. As the shake correction head amplifier 13, for example, an angular velocity sensor or the like can be used.

The VR switch 14 is a switch for turning on / off the shake correction drive and switching between the shake correction mode 1 and the shake correction mode 2. Here, for example, the blur correction mode 1 is a mode for performing rough control when correcting the blur of the finder image after the shooting preparation start operation,
The blur correction mode 2 is a mode in which precise control is performed when blur is corrected during actual exposure.

The distance encoder 15 is an encoder for detecting the focus position and converting it into an electric signal, and its output is similarly the blur correction control microcomputer 3, the ultrasonic motor microcomputer 16 and the communication microcomputer. It is connected to the computer 24.

Microcomputer 16 for ultrasonic motor
Is for controlling the ultrasonic motor 19 that drives the focusing optical system drive unit. The USM encoder 17 is
It is an encoder that detects the amount of movement of the ultrasonic motor 19, and its output is connected to the USM encoder IC 18. The USM encoder IC 18 is a circuit that converts the movement amount of the ultrasonic motor 19 into an electric signal, and the signal is
It is sent to the ultrasonic motor microcomputer 16.

The ultrasonic motor 19 is a motor for driving the focusing optical system. The ultrasonic motor drive circuit 20 is a circuit which has a drive frequency specific to the ultrasonic motor 19 and generates two drive signals having a 90 ° phase difference from each other.
The ultrasonic motor IC 21 is a circuit that interfaces between the ultrasonic motor microcomputer 16 and the ultrasonic motor drive circuit 20.

The zoom encoder 22 is an encoder for detecting the focal length position of the lens and converting it into an electric signal, and its output is sent to the blur correction control microcomputer 3, the ultrasonic motor microcomputer 16 and the communication microcomputer 24. Connected.

The DC-DC converter 23 is a circuit that supplies a stable DC voltage against fluctuations in battery voltage.
It is controlled by a signal from the communication microcomputer 24.

The communication microcomputer 24 communicates between the lens apparatus 1 and the body apparatus 2 and transmits a command to the other microcomputer 3 in the lens apparatus 1, the ultrasonic motor microcomputer 16 and the like.

The body microcomputer 25 instructs the blur correction display section 27 to display a warning based on the maximum blur correction time information transmitted from the lens device 1, the exposure setting information, the subject brightness information, and the like.

The release switch 28 is provided in the body device 2. When the user of the photographing apparatus transmits the start of exposure control to the body device and is designated by the blur correction control start switch determination processing, the blur correction control signal is issued. Determine the transmission timing of. Half-press switch SW that starts shooting preparation operation by half-pressing the release button by the user of the imaging device
1 and a full-press switch SW2 for instructing the start of exposure control by full-pressing the release button.

The camera provided with the shake correction mechanism in this embodiment is configured as described above. FIG. 2 is a flowchart illustrating the operation sequence of the image capturing apparatus according to this embodiment.

Step (hereinafter abbreviated as "S") 2
At 00, the communication microcomputer 24 prepares for communication. At the same time, the shake correction control microcomputer 3 prepares for communication in S201, and the ultrasonic motor microcomputer 16 prepares for communication in S202.

In step S203, the communication microcomputer 24 communicates with the body device 2 via the lens contact 4. In step S204, the focus control instruction received from the body 2 is sent to the ultrasonic motor microcomputer 1
6 is transmitted.

In step S205, the ultrasonic motor microcomputer 16 performs focusing control based on the information of the zoom encoder 22, the distance encoder 15, and the like. In step S206, the blur correction control instruction received from the body device 2 is transmitted to the blur correction control microcomputer 3.

In S207, the shake correction control microcomputer 3 performs a shake correction calculation. In step S208, the blur correction control microcomputer 3 performs blur correction control. FIG. 4 is an explanatory diagram showing a detailed operation sequence of the blur correction calculation routine of S207 in FIG.

In step S401, it is determined whether the shake correction control instruction from the communication microcomputer 24 is a shake correction start command. If it is a shake correction start command, S4
Go to 02. On the other hand, if it is not the shake correction start command, S
Proceed to 404.

In S402, the time when the shake compensation control start instruction is issued from the communication microcomputer 24 is
It is stored as the blur correction start time Ts. In step S403, the shake correction control completion flag is cleared.

In S404, it is determined whether or not the shake correction control completion flag is set. If not set, the process proceeds to S405. If it is set, it returns.

In S405, the zoom encoder 22
From the focal length information read from, the maximum blur correction time corresponding to the focal length is calculated. In S406, S40
The maximum blur correction time calculated in 5 is stored in Tm.

At S407, the current time is read out,
The current time Tp is stored. In S408, S406
Difference T between the maximum blur correction time Tm stored in step S407 and the current time Tp stored in step S407 and the blur correction start time Ts stored in step S402 (Tp-Ts)
e (Tm- (Tp-Ts)) is calculated.

In step S409, it is determined whether the difference Te calculated in step S408 is greater than zero. If it is greater than zero, the process proceeds to S410, and if it is zero or less than zero, the process proceeds to S411.

In S410, the motor drive duty transmitted to the X-axis motor driver 8 and the Y-axis motor driver 12 in FIG. 1 is calculated. In S411, the motor drive duty transmitted to the X-axis motor driver 8 and the Y-axis motor driver 12 is set to zero.

In step S412, the shake correction control completion flag is set. FIG. 5 is a graph showing an example of the difference between the exposure blur amount due to the target speed when the velocity error component is not included and the exposure blur amount due to the target velocity when the velocity error component is included, as a time-image position relationship. is there.

When the angular velocity of the target lens position when the velocity error component is not included is V = f ₁ (t) and the target lens position of the velocity error component is V = K, the target lens position when the velocity error component is included The angular velocity of can be expressed by V = f ₂ (t) = f ₁ (t) + K.

Here, the film exposure blur amount S _{1 in the} case of performing blur correction control from time 0 to time T ₂ is between the curve V = f ₂ (t) and the curve V = f ₁ (t). The area is expressed by the following formula.

[0040]

[Equation 1]

However, the integration range is from time 0 to time T ₂ . On the other hand, the film exposure blur amount S ₂ from time 0 to time T ₂ when the blur correction control is not performed is the area between the curve V = f ₁ (t) and the time axis, and the symbol || The value is represented by the following formula.

[0042]

[Equation 2]

However, the integration range is from time 0 to time T ₂ . As shown in FIG. 5, in the range from time 0 to time T ₂ , the film exposure blur amount S ₁ when the blur correction control is performed is compared with the film exposure blur amount S ₂ when the blur correction is not performed. And get bigger.

On the other hand, between the time 0 and the time T ₁ , the film exposure blur amount S ₁ when the blur correction control is performed and the film exposure blur amount S when the blur correction is not performed
_{When 2} is calculated, the film exposure blur amount S ₁ due to the speed error component becomes smaller than the film exposure blur amount S ₂ when the blur correction control is not performed, and the time 0 to the time T ₁
In the range up to, it is possible to secure a sufficiently large effect by the shake correction control.

That is, according to the present invention, the time T ₁ is calculated as a different value for each focal length, and the maximum blur correction time T _max which is a predetermined time for stopping the blur correction control (the _maximum blur correction control is possible). It is possible to eliminate the increase in the exposure blur amount due to the error component K of the target moving speed of the blur correction optical system calculated by the blur correction control calculation by variably controlling the time.

The maximum blur correction time T _max is preferably set to a time during which the exposure blur amount due to the error component K of the target moving speed is within the permissible range of blur correction driving. Table 1 shows an example of the relationship between the focal length and the maximum blur correction time.

[0047]

[Table 1]

In FIG. 6, the position H is the principal plane of the photographing optical system and the position I is the film surface, and the focal length of the photographing optical system (distance between the position H and the position I) and the image blur amount L on the film surface. It is explanatory drawing which shows the relationship of.

As shown in FIG. 6A, the focal length is f ₁
Therefore, when the blur angular velocity is ω (deg / s), the displacement amount of the blur angle θ during the control time t ₁ (s) is represented by the following formula.

[0050]

(Equation 3)

On the other hand, the image blur amount L on the film surface is
It is represented by the following formula.

[0052]

(Equation 4)

If the error component of the target speed is K,
The image blur amount Ld _{1 on the} film surface due to the error component is
It is represented by the following formula.

[0054]

(Equation 5)

Here, the error component K of the target speed is constant, and the focal length of the photographing optical system is f as shown in FIG. 6B).
_When changing from ₁ to f ₂ , the amount of image blur Ld on the film surface
₂ is represented by the following formula.

[0056]

(Equation 6)

In order to make the image blur amounts Ld ₁ and Ld ₂ equal regardless of the change of the focal length, the time t ₂ that satisfies the following equation may be determined as the maximum blur correction time by the equation. .

[0058]

(Equation 7)

In this way, in this embodiment, the maximum blur correction time is changed and set according to the changing focal length, and the blur of the blur correction controller is set based on the newly set maximum blur correction time. Regardless of the correction control signal,
Even if the focal length of the shooting optical system changes, sufficient blur correction control is performed by stopping the drive of the blur correction drive unit after the maximum blur correction time has elapsed from the start of blur correction control It is possible to obtain excellent image quality.

(Modifications) The present invention is not limited to the above-described first embodiment, and various modifications and changes are possible, which are also included in the present invention. For example, although the first embodiment has been described by taking the case where the present invention is applied to the lens device of a single-lens reflex camera in which the lens device and the body device are detachable, it can also be applied to the lens unit of the compact camera.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of a camera including a shake correction mechanism according to the present invention.

FIG. 2 is a flowchart illustrating an operation sequence of the image capturing apparatus according to the first embodiment.

FIG. 3 is a schematic diagram showing a configuration of a camera including the shake correction mechanism of the first embodiment.

FIG. 4 is an explanatory diagram showing a detailed operation sequence of a blur correction calculation routine of S207 in FIG.

FIG. 5 is a graph showing an example of a difference between an exposure blur amount according to a target speed when a speed error component is not included and an exposure blur amount according to a target speed when a speed error component is included, in a time-image position relationship. .

FIG. 6 shows the relationship between the focal length (distance between position H and position I) of the photographing optical system and the image blur amount on the film surface, with position H being the main plane of the photographing optical system and position I being the film surface. FIG.

[Explanation of symbols]

 1 Lens Device 2 Body Device 3 Microcomputer for Blurring Correction Control 4 Lens Contact 5 X Encoder 6 X Encoder IC 7 X Axis Drive Motor 8 X Axis Motor Driver 9 Y Encoder 10 Y Encoder IC 11 Y Axis Drive Motor 12 Y Motor Driver 13 Shake correction head amplifier (angular velocity sensor) 14 VR switch 15 Distance encoder 16 Microcomputer for ultrasonic motor 17 USM encoder 18 USM encoder IC 19 Ultrasonic motor 20 Ultrasonic motor drive circuit 21 Ultrasonic motor IC 22 Zoom encoder 23 DC- DC converter 24 Microcomputer for communication 25 Microcomputer for body 26 Object finder 27 Blurring correction display section 28 Release switch

Claims (2)

[Claims] 1. A blurring system for detecting blurring of a photographing optical system and an optical axis of the photographing optical system and moving a part or all of the photographing optical system and a photographing screen relative to each other based on the detected blurring amount. An image pickup apparatus including a correction mechanism, wherein the shake correction mechanism changes a maximum shake correction time, which is a maximum time during which shake correction control can be performed, based on a focal length of the photographing optical system. An imaging device equipped with a characteristic blur correction mechanism. 2. A photographing optical system and a photographing incorporated in a body device which detects blurring of an optical axis of the photographing optical system and is combined with a part or all of the photographing optical system based on the detected blur amount. A blur correction mechanism for relatively moving a screen, wherein the blur correction mechanism is a maximum time for which blur correction control can be performed based on a focal length of the photographing optical system. A lens device provided with a blur correction mechanism characterized by changing a maximum blur correction time.