JP2004191647A - Imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make an optimum movement correcting function selectable according to the use state of a camera by using the features of a movement correcting function by image signal processing and an optical movement correcting function. <P>SOLUTION: A controller 19 detects whether or not a user has selected a movement correcting function by monitoring the state of a camera shake correction switch 6; when the camera shake correction switch 6 is on, a camera shake correcting photography mode is entered and then the controller 19 decides a function of a lens unit 2. When it is decided that the lens unit 2 is not equipped with a movement correcting function, photography is performed in 1st movement correction mode using an image signal processing part 9. When it is decided that the lens unit 2 is equipped with the movement correcting function, on the other hand, photography is performed in 2nd movement correcting mode using a lens driving part 12. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an imaging device in which a lens unit is detachable from an imaging device main body.
[0002]
[Prior art]
In camera shooting, camera shake is one of the causes of an unintended result such as deterioration of image quality. Not only for photographers who are not skilled in camera shooting, but also for those who are not skilled in camera shooting, such as when the hold performance is impaired by reducing the size and weight of the camera, when shooting with a long focus lens, when shooting at long seconds, etc. Shake is a big problem.
[0003]
Therefore, as a mechanism for reducing camera shake during camera shooting, a method based on signal processing for correcting the camera shake by appropriately changing the image reading range and an optical method for correcting the camera shake by moving the optical axis of the imaging optical system. A scheme has been proposed.
[0004]
The method based on image signal processing includes a motion vector detection circuit that compares two temporally consecutive images to detect the motion of the entire image, an imaging unit that can capture an image of a wider area than the screen, and a motion vector detection circuit. The amount of correction is calculated from the output of the circuit, and the image output range of the imaging unit is changed according to the amount of correction to obtain an image in which blur has been corrected. The feature is that since there is no mechanically moving portion, the power consumption can be reduced as compared with the optical system described later. On the other hand, since it is essentially a function of correcting an image shift between frames, it is not suitable for motion correction within one frame as in the case of recording a still image, and further, the image quality is deteriorated even in the case of recording a moving image. There is also a feature.
[0005]
The optical system detects the movement of the lens unit using a gyro and corrects blurring by changing the eccentricity of a specific lens according to the direction and amount of movement, and changes the vertex angle of the variable vertex prism By doing so, the blur is reduced. As a feature, a mechanical driving force by an actuator is required for driving a lens and the like, and power consumption is increased as compared with motion correction by image signal processing. On the other hand, since motion correction can be performed even during exposure of one frame, motion correction can be performed without deteriorating image quality regardless of whether a still image is recorded or a moving image is recorded.
[0006]
[Problems to be solved by the invention]
It is possible to mount a motion correction function by image signal processing on a lens-interchangeable digital camera or video camera using an image sensor such as a CCD. Further, an exchangeable lens unit having an optical motion correction function has been proposed.
[0007]
However, there is no example in which a camera having a motion compensation function based on image signal processing is combined with a lens unit having an optical motion compensation function to effectively utilize both motion compensation functions.
[0008]
The present invention has been made in view of the above points, and utilizes the respective features of a motion compensation function based on image signal processing and an optical motion compensation function, and provides an optimal motion compensation function according to a use state of a camera. The purpose is to be able to select.
[0009]
[Means for Solving the Problems]
An imaging apparatus according to the present invention is an imaging apparatus in which a lens unit is detachably attached to an imaging apparatus main body, wherein the imaging apparatus main body performs an imaging unit for acquiring an image signal and performs motion correction by image signal processing. It is characterized in that it comprises image signal processing means and determination means for determining whether or not the mounted lens unit has an optical motion correction function.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an imaging apparatus such as a digital camera or a video camera of an interchangeable lens type according to the present embodiment. In FIG. 1, reference numeral 1 denotes a camera body, and 2 denotes a lens unit. Reference numeral 3 denotes a mount that mechanically and electrically detachably couples the camera body 1 and the lens unit 2. Reference numeral 4 denotes a lens group that forms an optical system of the lens unit 2, and reference numeral 5 denotes a CCD that captures a subject image formed by the lens group 4. An image signal digitized by AD conversion (not shown) is output from the CCD 5.
[0011]
Reference numeral 6 denotes a camera shake correction switch for instructing the camera body to start an operation of a function for correcting camera shake. The camera shake correction switch 6 is monitored by a controller 19 described later. When the switch is turned on, an optimum camera shake correction function is operated according to the state of the imaging apparatus.
[0012]
First, the motion compensation function provided in the camera body 1 will be described. This is to correct the motion of an image by image signal processing. Reference numeral 9 denotes an image signal processing unit including a first motion detecting unit 7 and a first motion correcting unit 8. The first motion detection unit 7 compares two temporally continuous subject images output from the CCD 5 and detects the direction and amount of motion between images due to camera shake or the like. The first motion corrector 8 changes the reading position of the CCD 5 according to the detection result of the first motion detector 7.
[0013]
Here, the change of the reading position of the CCD 5 will be described. FIG. 2 is a diagram illustrating the relationship between the imaging range of the CCD 5 and the reading range. Reference numeral 51 denotes an imaging range of the CCD 5, which is a range in which a subject image via the lens unit 2 can be converted into an image signal. Reference numeral 52 denotes a reading range of the CCD 5, which is a range in which a subject image signal output to the display unit 15 and the image recording unit 16 of the camera body 1 described later is output. Reference numeral 53 denotes a reading start position of the reading range 52. By changing this position, the reading range 52 can be set to a desired position in the imaging range 51. The read start position 53 is appropriately changed according to an instruction from the first motion correction unit 7, and an image in which the motion of the image due to camera shake or the like has been corrected can be output.
[0014]
In the motion correction using the image signal processing unit 9, there is no mechanically operated element, so that power consumption can be reduced as compared with the optical motion correction described later. However, since motion compensation is performed by detecting the motion of the image between two consecutive frames and changing the readout position of the CCD 5, the motion compensation within one frame cannot be performed. It is not suitable for correction. Further, there is a characteristic that the image quality is inferior to that of optical motion correction even at the time of shooting a moving image.
[0015]
Next, a motion correction function provided in the lens unit 2 will be described. This is to optically correct the movement of the image. Reference numeral 12 denotes a lens driving unit which includes a second motion detecting unit 10 and a second motion correcting unit 11 and drives the eccentric lens 13 via an actuator 14 described later. The second motion detection unit 10 includes an attitude detection device such as a gyro, and detects an optical axis shift of the lens unit 2 caused by camera shake or the like. The second motion corrector 11 calculates a direction and an amount to be corrected for motion correction by optical means described later, according to the output of the second motion detector 10.
[0016]
Reference numeral 13 denotes a lens constituting the lens group 4, which is movably supported in an arbitrary direction within a plane perpendicular to the optical axis and has an optical function of changing the optical axis according to the amount of movement. Lens. Reference numeral 14 denotes an actuator that drives the eccentric lens 13 according to an instruction from the lens driving unit 12. In other words, the motion of the image detected by the second motion detecting unit 10 is finally corrected by the eccentric lens 13, so that the subject image formed on the CCD 5 has been subjected to the motion correction.
[0017]
The motion correction using the lens driving unit 12 consumes more power than the motion correction method based on signal processing because of the mechanical element of driving the lens. However, since the motion correction function always operates during exposure of one frame, not only can motion correction during still image shooting be performed, but also image quality can be improved during moving image shooting.
[0018]
Here, it returns to the description of the operation of the imaging device of the interchangeable lens type. Reference numeral 15 denotes a display unit for displaying an image picked up by the CCD 5, and reference numeral 16 denotes an image recording unit for recording an image picked up by the CCD 5. Reference numeral 17 denotes a power supply unit serving as a power supply for the camera body 1 and the lens unit 2. Reference numeral 18 denotes a recording mode setting switch for the user to set a recording method of the camera to a still image or a moving image.
[0019]
Reference numeral 19 denotes a controller that controls and monitors the operation of each unit of the interchangeable lens camera system. The above-mentioned CCD 5, camera shake correction switch 6, image signal processing unit 9, display unit 15, image recording unit 16, power supply unit 17, recording mode The setting switch 18 and the lens unit 2 are controlled and monitored.
[0020]
The function of the controller 19 will be described in more detail. The controller 19 monitors the power supply voltage of the power supply unit 17, and when the power supply voltage is lower than a predetermined value, performs control to turn off the power supply in order to prevent malfunction of the imaging device. Further, when the power consumption is large, such as when operating the motion compensation function by driving the lens, power management such as comparing the power supply voltage with another predetermined value is performed. In addition, by communicating with the mounted lens unit 2, it has a function of determining the function of the lens unit 2 and accurately grasping the state of the imaging device.
[0021]
Hereinafter, the operation of the imaging apparatus according to the present embodiment for selecting the motion correction function will be described with reference to three operation examples and corresponding flowcharts.
[0022]
FIG. 3 is a flowchart showing a first operation example. In FIG. 3, first, the controller 19 monitors and detects the state of the camera shake correction switch 6 to determine whether or not the camera shake correction function is selected by the user (step S100).
[0023]
When the camera shake correction switch 6 is off, shooting is performed in the normal shooting mode without performing motion correction (steps S101 and S106).
[0024]
If the camera shake correction switch 6 is on, the camera shake correction shooting mode is set, and then the function of the lens unit 2 is determined by the controller 19 (steps S102 and S103). If it is determined that the lens unit 2 does not have a motion correction function, shooting is performed in the first motion correction mode using the image signal processing unit 9 (steps S104 and S106).
[0025]
On the other hand, when it is determined that the lens unit 2 has the motion compensation function, the photographing is performed in the second motion compensation mode using the lens driving unit 12 (steps S105 and S106).
[0026]
According to the first operation example described above, in the camera shake correction photographing mode, if possible, the lens drive method is used to improve the image quality, so that the user can use the camera shake correction switch 6 to perform the camera shake correction function. Just by selecting, the optimal motion compensation function can be used in the camera system.
[0027]
FIG. 4 is a flowchart showing a second operation example. In FIG. 4, first, the controller 19 monitors and detects the state of the camera shake correction switch 6 to determine whether the camera shake correction function is selected by the user (step S200).
[0028]
When the camera shake correction switch 6 is off, shooting is performed in the normal shooting mode without performing motion correction (steps S201 and S207).
[0029]
When the camera shake correction switch 6 is ON, the camera shake correction shooting mode is set, and then the function of the lens unit 2 is determined by the controller 19 (steps S202 and S203). If it is determined that the lens unit 2 does not have a motion correction function, shooting is performed in the first motion correction mode using the image signal processing unit 9 (steps S204 and S207).
[0030]
On the other hand, when it is determined that the lens unit 2 has the motion compensation function, the controller 19 measures the power supply voltage of the power supply unit 17 (step S205). If the power supply voltage is less than the predetermined value, shooting is performed in the first motion compensation mode using the image signal processing unit 9 that consumes less power (steps S204 and S207). If the power supply voltage is equal to or higher than the predetermined level, shooting is performed in the second motion compensation mode using the lens driving unit 12 that consumes much power but improves image quality (steps S206 and S207).
[0031]
According to the second operation example described above, in the camera shake correction photographing mode, an optical motion correction function is provided, and if the power supply voltage is equal to or higher than a predetermined level, the lens driving method can further improve the image quality. Make corrections. On the other hand, even when an optical motion compensation function is provided, when the power supply voltage is lower than a predetermined level, the motion compensation function that consumes less power is automatically selected. By simply selecting, the optimal motion compensation function can be used in the camera system without worrying about power.
[0032]
FIG. 5 is a flowchart showing a third operation example. In FIG. 5, first, the controller 19 monitors and detects the state of the camera shake correction switch 6 to determine whether or not the camera shake correction function is selected by the user (step S300).
[0033]
When the camera shake correction switch 6 is off, shooting is performed in the normal shooting mode without performing motion correction (steps S301 and S307).
[0034]
When the camera shake correction switch 6 is on, the camera shake correction shooting mode is set, and then the recording mode setting switch 18 is detected by the controller 19, and the recording mode is determined (step S303). If the recording mode is not the still image recording mode, the mode automatically switches to the moving image recording mode, and shooting is performed in the first motion compensation mode using the image signal processing unit 9 that consumes less power (steps S304 and S307).
[0035]
On the other hand, when the recording mode is the still image recording mode, the controller 19 determines the function of the lens unit 2 (step S305). If it is determined that the lens unit 2 does not have the motion compensation function, the mode is changed to the normal shooting mode again, and shooting is performed (steps S301 and S307). At this time, it is desirable that the camera system clearly indicates to the user that shooting is performed in the normal shooting mode instead of the camera shake correction mode.
[0036]
On the other hand, if it is determined that the lens unit 2 has the motion compensation function, the image is captured in the second motion compensation mode using the lens driving unit 12 that can improve the image quality in still image capturing. This is performed (steps S306 and S307).
[0037]
According to the third operation example described above, the user only selects the camera shake correction function by using the camera shake correction switch 6, and the power consumption and the image quality can be improved between still image shooting and moving image shooting. In consideration of the condition, the optimal motion compensation function can be used.
[0038]
(Other embodiments)
A software program for realizing the functions of the above-described embodiments is provided to an apparatus connected to the various devices or a computer in the system so that the various devices operate to realize the functions of the above-described embodiments. The present invention also includes a code that is supplied and executed by operating the various devices according to a program stored in a computer (CPU or MPU) of the system or the apparatus.
[0039]
In this case, the software program code itself implements the functions of the above-described embodiment, and the program code itself constitutes the present invention. As a transmission medium for the program code, a communication medium (a wired line or a wireless line such as an optical fiber) in a computer network (LAN, a WAN such as the Internet, a wireless communication network, etc.) system for transmitting and supplying the program information as a carrier wave. Etc.) can be used.
[0040]
Further, a means for supplying the program code to a computer, for example, a recording medium storing the program code constitutes the present invention. As a recording medium for storing such a program code, for example, a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a magnetic tape, a nonvolatile memory card, a ROM, and the like can be used.
[0041]
When the computer executes the supplied program code, not only the functions of the above-described embodiments are realized, but also the OS (operating system) or other application software running on the computer in the program code. Needless to say, the program code is also included in the embodiment of the present invention when the functions of the above-described embodiment are realized in cooperation with the above.
[0042]
Further, after the supplied program code is stored in a memory provided in a function expansion board of a computer or a function expansion unit connected to the computer, a CPU provided in the function expansion board or the function expansion unit based on the instruction of the program code. It is needless to say that the present invention also includes a case where the functions of the above-described embodiments are implemented by performing part or all of the actual processing.
[0043]
It should be noted that the shapes and structures of the respective parts shown in the above-described embodiments are merely examples of the specific embodiments for carrying out the present invention, and the technical scope of the present invention is limited by these. It must not be interpreted. That is, the present invention can be embodied in various forms without departing from the spirit or main features thereof.
[0044]
Hereinafter, examples of embodiments of the present invention will be listed.
(Embodiment 1) An imaging apparatus in which a lens unit is detachable from an imaging apparatus main body,
The imaging device body includes:
Imaging means for acquiring an image signal;
Image signal processing means for performing motion correction by image signal processing;
An imaging device comprising: a determination unit configured to determine whether the mounted lens unit has an optical motion correction function.
[0045]
(Embodiment 2) When the determination unit determines that a lens unit having an optical motion correction function is mounted, the imaging device body corrects the motion by the optical motion correction function of the lens unit. The imaging apparatus according to the first embodiment, further comprising control means for performing motion compensation by the image signal processing means in other cases.
[0046]
(Embodiment 3) The imaging device main body is provided with a power supply voltage detecting means for detecting a power supply voltage of the imaging device main body and the lens unit, and a lens unit having an optical motion correcting function by the determining means. Is determined, and when the power supply voltage is determined by the power supply voltage detecting means to be equal to or higher than a predetermined value, motion compensation is performed by an optical motion compensation function of the lens unit; otherwise, the motion compensation is performed. The imaging apparatus according to the first embodiment, further comprising control means for performing motion correction by the image signal processing means.
[0047]
(Embodiment 4) It has a still image recording mode for recording a still image and a moving image recording mode for recording a moving image, and the imaging device main body is provided with a lens unit having an optical motion correction function by the determination means. Control means for performing motion compensation by an optical motion compensation function of the lens unit when it is determined that the lens unit is in the still image recording mode, and otherwise, performing motion compensation by the image signal processing means. The imaging device according to the first embodiment, comprising:
[0048]
(Embodiment 5) The image signal processing means includes: a motion detecting means for detecting a motion of an image from an image signal output by the image capturing means; The imaging apparatus according to any one of the first to fourth embodiments, further comprising a motion correcting unit that corrects the motion.
[0049]
(Embodiment 6) A lens unit can be attached to and detached from an imaging device main body, and the imaging device main body includes imaging means for acquiring an image signal and image signal processing means for performing motion correction by image signal processing. A method for controlling an imaging device, comprising:
A method for controlling an imaging apparatus, comprising: determining whether a mounted lens unit has an optical motion correction function.
[0050]
(Embodiment 7) A lens unit can be attached to and detached from an imaging apparatus main body, and the imaging apparatus main body includes imaging means for acquiring an image signal and image signal processing means for performing motion correction by image signal processing. A program for controlling an imaging device provided with
A program for executing a process of determining whether a mounted lens unit has an optical motion correction function.
[0051]
(Eighth Embodiment) A computer-readable storage medium storing the program according to the seventh embodiment.
[0052]
【The invention's effect】
As described above, according to the present invention, when both the imaging apparatus main body and the lens unit have a correction function for camera shake correction, even if the user does not understand the characteristics of the respective motion correction functions. Since the optimal motion compensation function is selected on the camera system side, the user can use the camera system without feeling troublesome.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a configuration of an imaging device according to an embodiment.
FIG. 2 is a diagram illustrating a change in a reading position of a CCD.
FIG. 3 is a flowchart for explaining a first operation example in the embodiment of the present invention.
FIG. 4 is a flowchart illustrating a second operation example according to the embodiment of the present invention.
FIG. 5 is a flowchart for explaining a third operation example in the embodiment of the present invention.
[Explanation of symbols]
1 Camera body 2 Lens unit 3 Mount 4 Lens group 5 CCD
Reference Signs List 6 Camera shake correction switch 7 First motion detecting unit 8 First motion correcting unit 9 Image signal processing unit 10 Second motion detecting unit 11 Second motion correcting unit 12 Lens driving unit 13 Eccentric lens 14 Actuator 15 Display unit 16 Image recording unit 17 Power supply unit 18 Recording mode setting switch 19 Controller 51 Imaging range 52 Reading range 53 Reading start position

Claims (1)

An imaging device in which a lens unit is detachable from an imaging device body,
The imaging device body includes:
Imaging means for acquiring an image signal;
Image signal processing means for performing motion correction by image signal processing;
An imaging apparatus comprising: a determination unit configured to determine whether the mounted lens unit has an optical motion correction function.

Images