JP5051812B2 - Imaging apparatus, focusing method thereof, and recording medium - Google Patents

Description

  The present invention relates to an improvement of an autofocus system in an image pickup apparatus such as a digital camera, and more particularly to an image pickup apparatus that can contribute to shortening the time required for autofocus, power consumption reduction, and prevention of failed shooting, and a focusing method and recording medium thereof. It is.

In general, an electronic imaging apparatus such as a digital still camera is equipped with an autofocus (AF) system for automatically focusing. As a method of autofocusing, for example, a control method disclosed in Patent Document 1 (Japanese Patent Publication No. 39-5265) is widely used as hill-climbing AF control. In this hill-climbing AF control, an integrated value of a high-frequency component or a luminance difference between adjacent pixels is obtained from a video signal obtained for each field or frame, and this is used as an AF evaluation value indicating the degree of focus. The AF evaluation value increases when the subject is in focus because the edge portion of the subject is clear, and the AF evaluation value decreases when the subject is out of focus. When the AF operation is performed, the AF evaluation values are sequentially acquired while moving the lens, and the lens is stopped with the point where the AF evaluation value is maximized as the focal point.
An apparatus that captures a still image, such as a digital still camera, generally requires strict focusing as compared to an apparatus that captures a moving image such as a video camera. The focusing operation is always repeated in the recording mode.

However, in the macro mode and the telephoto side of the zoom camera, so-called TELE side, the amount of movement of the focus lens in the distance measurement range becomes large. Therefore, if the hill-climbing control AF is performed for each shooting, the operator can perform the shooting start request operation. There is a problem that a time difference, that is, a release time lag, occurs after the image is taken until the actual shooting is performed. Further, since the focus lens is moved by the motor as an AF scan operation for all target areas at every photographing, a large amount of power is consumed, and the life of a battery normally used as a power source is reduced.
In addition, for example, when an object is photographed through a wire mesh, there is a problem that if the AF scan operation is performed on the entire target area, the AF evaluation value reaches a peak on the wire mesh, causing a malfunction that the object to be photographed is blurred. . As a countermeasure against such a problem, for example, Patent Document 2 (Japanese Patent Laid-Open No. Sho 54-113334) and the like propose to limit the range for performing the focus determination.
Patent Document 3 (Japanese Patent Laid-Open No. 2003-230039), Patent Document 4 (Japanese Patent Laid-Open No. 2003-262786), Patent Document 5 (Japanese Patent Laid-Open No. 9-212298), and the like describe an AF scan range, that is, a motor. Is limited to a specific range.

  That is, Patent Document 2 discloses that a focus position detection is performed by selecting a desired distance range from the entire distance range, but only data in a desired range of the scan range by the whole area scan is disclosed. Although it is used and effective in preventing erroneous determination, it does not contribute much to shortening the time required for AF operation and reducing power. Japanese Patent Application Laid-Open No. 2004-228688 discloses that AF scanning is performed with a focus range limited when a release is operated while operating a specific button. The technique disclosed in Patent Document 3 limits the AF scan range to a preset range. Patent Document 4 discloses that an AF scan is performed by dividing an in-focus range and limiting it to one designated in-focus range. The technique disclosed in Patent Document 4 divides a focusing range, performs AF scanning only in one designated focusing range, and performs AF scanning in the other range only when focusing cannot be performed. Patent Document 5 discloses selecting and setting whether or not to divide the movement range of the focus lens into a movable area and a movement prohibited area, and preventing the focus lens from being positioned in the movement prohibited area at the time of division. .

Japanese Examined Patent Publication No. 39-5265 JP 54-113334 A Japanese Patent Laid-Open No. 2003-230039 JP 2003-262786 A JP-A-9-212298

The present invention has been made in view of the above-described circumstances, and achieves speeding up of AF operation and reduction of power consumption in an imaging apparatus, prevents false focusing due to erroneous determination, and improves usability. It is an object of the present invention to provide a focusing method and a recording medium.
The purpose of claim 1 of the present invention, a macro mode for photographing a close range object, Rutotomoni adapted to the characteristics of the shooting mode and the normal mode, when changing the zoom position in the zoom lens, regardless to the zoom position In addition, the release time lag is kept constant , effective AF speed reduction and power consumption reduction are achieved, false focus due to misjudgment is prevented, failed shooting is efficiently prevented, and usability is improved Another object is to provide an imaging device that can perform the above.
An object of claim 2 of the present invention is to provide an image pickup apparatus that can effectively prevent photographing in the false in-focus state.
An object of claim 3 of the present invention is to provide an imaging device that can achieve AF operation speed reduction and power consumption reduction more effectively, prevent false focusing due to erroneous determination, and improve usability. It is to provide.
An object of claim 4 of the present invention is to provide an imaging device that can achieve AF operation speed reduction and power consumption reduction more effectively, prevent false focusing due to erroneous determination, and improve usability. It is to provide.

The object of claim 5 of the present invention is to cope with the switching between the shooting mode between the macro mode for shooting a subject at close range and the normal mode, and to effectively speed up the AF operation and reduce the power consumption. An object of the present invention is to provide an imaging apparatus that can achieve and prevent false focusing due to erroneous determination and improve usability.
The object of claim 6 of the present invention is to cope with the change of the zoom position in the zoom lens, and to effectively achieve the high speed AF operation and reduce the power consumption, and prevent the false focusing due to the erroneous determination. Then, it is providing the imaging device which can improve usability .

An object of the seventh aspect of the present invention is to provide an image pickup apparatus that enables a flexible and effective countermeasure particularly when the in-focus position cannot be detected.
The purpose of the eighth aspect of the present invention, a macro mode for photographing a close range object, Rutotomoni adapted to the characteristics of the shooting mode and the normal mode, when changing the zoom position in the zoom lens, regardless to the zoom position In addition, the release time lag is kept constant , effective AF speed reduction and power consumption reduction are achieved, false focus due to misjudgment is prevented, failed shooting is efficiently prevented, and usability is improved It is another object of the present invention to provide a focusing method for an imaging apparatus that can be used.
The purpose of claim 9 of the present invention, a macro mode for photographing a close range object, Rutotomoni adapted to the characteristics of the shooting mode and the normal mode, when changing the zoom position in the zoom lens, regardless to the zoom position In addition, the release time lag is kept constant , effective AF speed reduction and power consumption reduction are achieved, false focus due to misjudgment is prevented, failed shooting is efficiently prevented, and usability is improved An object of the present invention is to provide a computer-readable recording medium .

In order to achieve the above-described object, an imaging apparatus according to the present invention described in claim 1
In an imaging device having an automatic focusing function,
Imaging means for converting light incident through the taking lens into an electrical signal and acquiring imaging data;
Focus lens position detection means for detecting the current focus lens position;
A focusing range designating unit for designating a narrow range in the vicinity of the current focus lens position detected by the focus lens position detecting unit as a focusing range from the entire focusing range in which the focus lens can be driven;
A focus lens drive range changing unit that changes a drive range of the focus lens in accordance with the focus range specified by the focus range specifying unit;
Display means for displaying the imaging data and displaying a focus range designated by the focus range designation means for all focus ranges that can be driven by the focus lens;
Macro mode switching means for switching between a macro mode for photographing a subject at a close distance and a normal mode for photographing a subject at a normal distance;
Zoom means for changing the focal length of the taking lens;
Zoom magnification changing means for changing the zoom magnification by the zoom means;
Means for changing a focus detection range according to the zoom magnification set by the zoom magnification changing means,
The focus range designation means is set to the macro mode by the macro mode switching means, and after performing the focus operation once, the focus range designation for the next and subsequent times is designated. A narrow area nearby,
The means for changing the focus detection range is such that, when the zoom magnification is changed by the zoom magnification changing means, the driving amount of the focus lens is constant regardless of the changed zoom magnification. It is characterized in that to limit the focus Asehan enclosed as.
An imaging device according to the present invention described in claim 2 is the imaging device according to claim 1,
A previous focus result storage means for storing the previous focus result;
When the focus range is specified by the focus range specification means, if the focus is not obtained from the previous focus result stored in the previous focus result storage means, a warning is displayed. And a warning display means for performing the operation.

An imaging device according to a third aspect of the present invention is the imaging device according to the first or second aspect, wherein the focus is changed to change a position of a narrow focus range designated by the focus range designation means. Range position changing means ;
Operating means for operating the imaging device ,
The focus range position changing unit is characterized in that the position of the narrow focus range is changed by an operation of the operation unit .
An imaging apparatus according to a fourth aspect of the present invention is the imaging apparatus according to any one of the first to third aspects, wherein a narrow focus range specified by the focus range specifying means is set. Further, it is characterized by further comprising a focusing range designation canceling means for canceling .

An imaging device according to the present invention described in claim 5 is the imaging device according to any one of claims 1 to 4 ,
The macro mode switching means for switching between a macro mode for photographing a subject at a close distance and a normal mode for photographing a subject at a normal distance;
And a means for automatically canceling the designation of the focus range when the focus range is designated by the focus range designation means when the macro mode switching means is switched. It is characterized by.
An imaging device according to a sixth aspect of the present invention is the imaging device according to any one of the first to fifth aspects,
Zoom means for changing the focal length of the taking lens;
Zoom magnification changing means for changing the zoom magnification by the zoom means;
Means for automatically canceling the designation of the focus range if the focus range is designated by the focus range designation means when the zoom magnification is changed by the zoom magnification change means; Furthermore, it is characterized by providing.

Imaging device according to the present invention described in 請 Motomeko 7 is an imaging apparatus of any one of claims 1 to 6,
As a result of performing the focusing operation in a state where a narrow range is designated by the focusing range designation means, an enlargement for selecting whether to perform re-ranging by enlarging the ranging range when the in-focus point is not found. Re-ranging selection means;
It is set when the in-focus point is not obtained within the narrow range set by the in-focus range specifying means and when the enlarged re-ranging selection is permitted by the enlarged re-ranging selection means. And a means for performing the focusing operation again in a wider range than the focusing range.

In order to achieve the above-described object, the focusing method of the imaging apparatus according to the present invention described in claim 8 provides:
In the focusing method of the imaging device, an imaging step of converting light incident through the imaging lens into an electrical signal and acquiring imaging data;
A focus lens position detection step for detecting the current focus lens position;
A focusing range designating step for designating a narrow range near the current focus lens position detected in the focus lens position detecting step as a focusing range from all focusing ranges in which the focus lens can be driven;
A focus lens drive range changing step for changing the drive range of the focus lens in accordance with the focus range specified by the focus range specifying step;
A display step of displaying the imaging data and displaying the in-focus range specified by the in-focus range specifying step with respect to the entire in-focus range in which the focus lens can be driven;
A macro mode switching step for switching between a macro mode for shooting a subject at a close distance and a normal mode for shooting a subject at a normal distance;
The zoom step of changing a focal length of the photographing lens;
The zoom magnification changing step for changing the zoom magnification by the zoom step;
Changing the range for focus detection according to the zoom magnification set by the zoom magnification changing step,
The focus range designation step is when the macro mode is set by the macro mode switching step, and after performing the focus operation once, the focus range designation for the next and subsequent times is designated. A narrow area nearby,
In the step of changing the focus detection range, when the zoom magnification is changed in the zoom magnification changing step, the driving amount of the focus lens is constant regardless of the changed zoom magnification. It is characterized in that to limit the focus Asehan enclosed as.
In order to achieve the above-described object, a computer-readable recording medium according to the present invention described in claim 9 is provided.
On the computer,
An imaging procedure for converting incident light through an imaging lens into an electrical signal and acquiring imaging data;
A focus lens position detection procedure for detecting the current focus lens position;
A focusing range designation procedure for designating a narrow range in the vicinity of the current focus lens position detected by the focus lens position detection procedure as a focusing range from the entire focusing range in which the focus lens can be driven;
A focus lens driving range changing procedure for changing the driving range of the focus lens in accordance with the focusing range specified by the focusing range specifying procedure;
A display procedure for displaying the imaging data and displaying the in-focus range specified by the in-focus range specifying procedure for all in-focus ranges that can be driven by the focus lens;
A macro mode switching procedure for switching between a macro mode for shooting a subject at a close distance and a normal mode for shooting a subject at a normal distance;
The zoom procedure for changing the focal length of the taking lens;
The zoom magnification changing procedure for changing the zoom magnification according to the zoom procedure,
And a procedure for changing a focus detection range according to the zoom magnification set by the zoom magnification change procedure,
The focus range designation procedure is when the macro mode is set by the macro mode switching procedure, and after performing the focus operation once, the focus range designation for the next and subsequent times is designated. A narrow area nearby,
In the procedure for changing the focus detection range, when the zoom magnification is changed by the zoom magnification changing procedure, the driving amount of the focus lens is constant regardless of the changed zoom magnification. It is characterized in that to limit the focus Asehan enclosed as.

[Action]
That is, an imaging device according to claim 1 of the present invention is
In an imaging device having an automatic focusing function,
Imaging means for converting light incident through the taking lens into an electrical signal and acquiring imaging data;
Focus lens position detection means for detecting the current focus lens position;
A focusing range designating unit for designating a narrow range in the vicinity of the current focus lens position detected by the focus lens position detecting unit as a focusing range from the entire focusing range in which the focus lens can be driven;
A focus lens drive range changing unit that changes a drive range of the focus lens in accordance with the focus range specified by the focus range specifying unit;
Display means for displaying the imaging data and displaying a focus range designated by the focus range designation means for all focus ranges that can be driven by the focus lens;
Macro mode switching means for switching between a macro mode for photographing a subject at a close distance and a normal mode for photographing a subject at a normal distance;
Zoom means for changing the focal length of the taking lens;
Zoom magnification changing means for changing the zoom magnification by the zoom means;
Means for changing a focus detection range according to the zoom magnification set by the zoom magnification changing means,
The focus range designation means is set to the macro mode by the macro mode switching means, and after performing the focus operation once, the focus range designation for the next and subsequent times is designated. A narrow area nearby,
The means for changing the focus detection range is such that, when the zoom magnification is changed by the zoom magnification changing means, the driving amount of the focus lens is constant regardless of the changed zoom magnification. limiting the alloy Asehan enclosed as.
With such a configuration, the macro mode for shooting a subject at close range and the characteristics of the shooting mode for the normal mode are adapted, and when the zoom position of the zoom lens is changed, the release time lag is constant regardless of the zoom position. As a result, it is possible to effectively increase the speed of AF operation and reduce power consumption, prevent false focusing due to erroneous determination, and improve usability. In other words, by specifying the AF scan range, the time required for AF can be shortened, and by narrowing the range in which the focus motor is operated, power consumption can be reduced, and when hill-climbing AF is performed In a subject having a depth such that a plurality of peaks appear, a subject in a desired range can be focused.
In addition, such a configuration can particularly effectively prevent failure shooting. In other words, since the current focus range is displayed, it is possible to reduce the number of failed shooting, and when the range is not limited, it is indicated that the entire region is the focus range. It can also be recognized in advance that the time lag will increase.

An imaging apparatus according to claim 2 of the present invention is the imaging apparatus according to claim 1,
A previous focus result storage means for storing the previous focus result;
When the focus range is specified by the focus range specification means, if the focus is not obtained from the previous focus result stored in the previous focus result storage means, a warning is displayed. And a warning display means for performing.
With such a configuration, it is possible to effectively prevent photographing in the false in-focus state. That is, in the previous AF result, the user recognizes the state by notifying the user that the area is limited in the out-of-focus state, so that the photographing is repeated without being in focus. Can be prevented .

Imaging device according to claim 3 of the present invention, in the imaging apparatus according to claim 1 or claim 2, and focusing range position changing means for changing the position of the narrow focus range specified by said focusing range specifying means ,
Operating means for operating the imaging device ,
The focus range position changing means changes the position of the narrow focus range by operating the operation means .
With such a configuration, it is possible to achieve the AF operation speed reduction and power consumption reduction more effectively, and to prevent false focusing due to erroneous determination, thereby improving usability. In addition, it is possible to easily cope with changes in the position of the subject and changes in shooting conditions.
An imaging apparatus according to a fourth aspect of the present invention is the imaging apparatus according to any one of the first to third aspects, wherein the focus is set to cancel the setting of the narrow focus range specified by the focus range specifying means. A range designation release unit is further provided.
With such a configuration, it is possible to achieve the AF operation speed reduction and power consumption reduction more effectively, and to prevent false focusing due to erroneous determination, thereby improving usability. A case where it is desired to perform AF again on the entire area can be dealt with .

The imaging device according to claim 5 of the present invention is the imaging device according to any one of claims 1 to 4 ,
The macro mode switching means for switching between a macro mode for photographing a subject at a close distance and a normal mode for photographing a subject at a normal distance;
And a means for automatically canceling the designation of the focus range when the focus range is designated by the focus range designation means when the macro mode switching means is switched.
With such a configuration, in particular, it is possible to cope with switching between the shooting mode between the macro mode for shooting a close-up subject and the normal mode, effectively achieving a high speed AF operation and a reduction in power consumption. It is possible to prevent false focusing by determination and improve usability. In other words, when switching the macro mode on / off, not only the shooting range is different, but also the subject is likely to change. Forgetting to cancel the setting can effectively prevent a shooting failure.

An imaging device according to a sixth aspect of the present invention is the imaging device according to any one of the first to fifth aspects,
Zoom means for changing the focal length of the taking lens;
Zoom magnification changing means for changing the zoom magnification by the zoom means;
Means for automatically canceling the designation of the focus range if the focus range is designated by the focus range designation means when the zoom magnification is changed by the zoom magnification change means; Further prepare.
With such a configuration, in particular, it is possible to cope with a change in the zoom position of the zoom lens, effectively achieve a high speed AF operation and reduce power consumption, prevent false focusing due to erroneous determination, and ease of use. Can also improve. That is, in such a case, there is a possibility that the shooting condition of the subject has changed. Therefore, by canceling the limitation of the range, the possibility of shooting failure can be kept low.

An imaging device according to a seventh aspect of the present invention is the imaging device according to any one of the first to sixth aspects,
As a result of performing the focusing operation in a state where a narrow range is designated by the focusing range designation means, an enlargement for selecting whether to perform re-ranging by enlarging the ranging range when the in-focus point is not found. Re-ranging selection means;
It is set when the in-focus point is not obtained within the narrow range set by the in-focus range specifying means and when the enlarged re-ranging selection is permitted by the enlarged re-ranging selection means. And a means for performing the focusing operation again in a range wider than the focusing range.
With such a configuration, it is possible to cope with a flexible and effective particularly when the in-focus position cannot be detected. That is, by performing the AF operation immediately after the recording becomes possible, an effect of reducing the release time lag can be obtained from the first shooting.

An imaging apparatus focusing method according to claim 8 of the present invention is:
An imaging step of converting light incident through the taking lens into an electrical signal and acquiring imaging data;
A focus lens position detection step for detecting the current focus lens position;
A focusing range designating step for designating a narrow range near the current focus lens position detected in the focus lens position detecting step as a focusing range from all focusing ranges in which the focus lens can be driven;
A focus lens drive range changing step for changing the drive range of the focus lens in accordance with the focus range specified by the focus range specifying step;
A display step of displaying the imaging data and displaying the in-focus range specified by the in-focus range specifying step with respect to the entire in-focus range in which the focus lens can be driven;
A macro mode switching step for switching between a macro mode for shooting a subject at a close distance and a normal mode for shooting a subject at a normal distance;
A zoom step for changing a focal length of the taking lens;
The zoom magnification changing step for changing the zoom magnification by the zoom step;
Changing the range for focus detection according to the zoom magnification set by the zoom magnification changing step,
The focus range designation step is when the macro mode is set by the macro mode switching step, and after performing the focus operation once, the focus range designation for the next and subsequent times is designated. A narrow area nearby,
In the step of changing the focus detection range, when the zoom magnification is changed in the zoom magnification changing step, the driving amount of the focus lens is constant regardless of the changed zoom magnification. limiting the alloy Asehan enclosed as.
With such a configuration, the zoom mode is adapted to the characteristics of the macro mode for photographing a close-up subject and the normal mode, and particularly to the zoom position of the zoom lens, when the zoom position is changed. Regardless of the zoom position, the release time lag is kept constant, effectively achieving high-speed AF operation and reducing power consumption in the imaging device, preventing false focusing due to misjudgment, and efficient failure shooting It is possible to improve the usability. Further, in the normal shooting mode, by not specifying the focus range, it becomes possible to easily cope with the change of the subject in the normal shooting mode, and the possibility of shooting failure can be reduced.

A computer-readable recording medium according to claim 9 of the present invention is provided.
On the computer,
An imaging procedure for converting incident light through an imaging lens into an electrical signal and acquiring imaging data;
A focus lens position detection procedure for detecting the current focus lens position;
A focusing range designation procedure for designating a narrow range in the vicinity of the current focus lens position detected by the focus lens position detection procedure as a focusing range from the entire focusing range in which the focus lens can be driven;
A focus lens driving range changing procedure for changing the driving range of the focus lens in accordance with the focusing range specified by the focusing range specifying procedure;
A display procedure for displaying the imaging data and displaying the in-focus range specified by the in-focus range specifying procedure for all in-focus ranges that can be driven by the focus lens;
A macro mode switching procedure for switching between a macro mode for shooting a subject at a close distance and a normal mode for shooting a subject at a normal distance;
The zoom procedure for changing the focal length of the taking lens;
The zoom magnification changing procedure for changing the zoom magnification according to the zoom procedure,
And a procedure for changing a focus detection range according to the zoom magnification set by the zoom magnification change procedure,
The focus range designation procedure is when the macro mode is set by the macro mode switching procedure, and after performing the focus operation once, the focus range designation for the next and subsequent times is designated. A narrow area nearby,
In the procedure for changing the focus detection range, when the zoom magnification is changed by the zoom magnification changing procedure, the driving amount of the focus lens is constant regardless of the changed zoom magnification. limiting the alloy Asehan enclosed as.
With such a configuration, the zoom mode is adapted to the characteristics of the macro mode for photographing a close-up subject and the normal mode, and particularly to the zoom position of the zoom lens, and the zoom position is changed. Regardless of the zoom position, the release time lag is kept constant, effectively achieving high speed AF operation and reducing power consumption in the imaging device, preventing false focusing due to misjudgment, and shooting failed It can effectively prevent and improve usability. Further, in the normal shooting mode, by not specifying the focus range, it becomes possible to easily cope with the change of the subject in the normal shooting mode, and the possibility of shooting failure can be reduced.

According to the present invention, the zoom position is adapted to the characteristics of the macro mode and the normal mode for photographing a close-up subject, and particularly to the change of the zoom position in the zoom lens. Regardless of the release time lag, the AF operation speed and power consumption of the imaging device can be increased, false focus caused by misjudgment can be prevented, failed shooting can be efficiently prevented, and usability can be improved. An imaging apparatus that can be improved, a focusing method thereof, and a recording medium can be provided.
That is, according to the imaging apparatus of claim 1 of the present invention, in the imaging apparatus having an automatic focusing function,
In an imaging device having an automatic focusing function,
Imaging means for converting light incident through the taking lens into an electrical signal and acquiring imaging data;
Focus lens position detection means for detecting the current focus lens position;
A focusing range designating unit for designating a narrow range in the vicinity of the current focus lens position detected by the focus lens position detecting unit as a focusing range from the entire focusing range in which the focus lens can be driven;
A focus lens drive range changing unit that changes a drive range of the focus lens in accordance with the focus range specified by the focus range specifying unit;
Display means for displaying the imaging data and displaying a focus range designated by the focus range designation means for all focus ranges that can be driven by the focus lens;
Macro mode switching means for switching between a macro mode for photographing a subject at a close distance and a normal mode for photographing a subject at a normal distance;
Zoom means for changing the focal length of the taking lens;
Zoom magnification changing means for changing the zoom magnification by the zoom means;
Means for changing a focus detection range according to the zoom magnification set by the zoom magnification changing means,
The focus range designation means is set to the macro mode by the macro mode switching means, and after performing the focus operation once, the focus range designation for the next and subsequent times is designated. A narrow area nearby,
The means for changing the focus detection range is such that, when the zoom magnification is changed by the zoom magnification changing means, the driving amount of the focus lens is constant regardless of the changed zoom magnification. by limiting the engagement Asehan circumference as, in particular, a macro mode for photographing a close distance object, the adapt to the characteristics of the shooting mode and the normal mode, in particular, it is adapted to the zoom position in the zoom lens, When changing the zoom position, regardless of the zoom position, the release time lag is kept constant, effectively achieving high-speed AF operation and reducing power consumption, and preventing false focusing caused by misjudgment. In addition, it is possible to effectively prevent unsuccessful shooting and improve usability.

According to the image pickup apparatus of claim 2 of the present invention, in the image pickup apparatus of claim 1, the in-focus range is determined by the previous in-focus result storing means for storing the previous in-focus result and the in-focus range specifying means. When it is set to specify, if the focus is not obtained in the previous focus result stored in the previous focus result storage means, further comprising a warning display means for displaying a warning, In particular, it is possible to effectively prevent photographing in the false in-focus state.
According to the imaging apparatus of claim 3 of the present invention, in the imaging apparatus of claim 1 or 2, the focus range position change for changing the position of the narrow focus range specified by the focus range specifying means. Means and operating means for operating the imaging device ,
The in-focus range position changing unit is configured to change the position of the narrow in-focus range by operating the operation unit , and particularly effectively achieves a high-speed AF operation and a reduction in power consumption. It is possible to prevent false focusing due to erroneous determination and improve usability.

According to an imaging device of a fourth aspect of the present invention, in the imaging device according to any one of the first to third aspects, the setting of the narrow focus range designated by the focus range designation means is canceled. By further providing the focusing range designation canceling means, it is possible to achieve the AF operation speed reduction and the power consumption reduction more effectively, prevent false focusing due to erroneous determination, and improve usability .
According to the imaging device of claim 5 of the present invention, in the imaging device of any one of claims 1 to 4 , a macro mode for photographing a subject at a close distance and a normal mode for photographing a subject at a normal distance. When the focus range is designated by the focus range designation means when the macro mode switching means and the macro mode switching means are switched, the focus range is automatically designated. Is provided with a means for canceling, particularly in response to switching between a macro mode for photographing a subject at a close distance and a photographing mode between a normal mode and effectively speeding up an AF operation and reducing power consumption. Can be achieved, and false focusing due to erroneous determination can be prevented, and usability can be improved.

According to an imaging device of a sixth aspect of the present invention, in the imaging device according to any one of the first to fifth aspects, a zoom means for changing a focal length of the photographing lens, and a zoom magnification by the zoom means. The zoom magnification changing means to be changed, and when the zoom magnification is changed by the zoom magnification changing means, if the focus range is designated by the focus range designation means, the focus range is automatically set. And a means for canceling the designation of the zoom lens, particularly in response to a change in the zoom position of the zoom lens, effectively achieving a high speed AF operation and a reduction in power consumption. It can prevent scorching and improve usability .

According to the imaging device of claim 7 of the present invention, in the imaging device of any one of claims 1 to 6, the focusing operation is performed in a state where a narrow range is specified by the focusing range specifying means. As a result, when the in-focus point cannot be found, the enlarged re-ranging selection unit that selects whether or not to perform re-ranging by enlarging the range, and the narrow range set by the focusing range designation unit In the case where the in-focus point is not obtained, and the enlargement / re-ranging selection unit permits the enlargement / re-distance measurement, the focusing operation is performed again in a range wider than the set focus range. By further including means for carrying out, it is possible to deal with a flexible and effective particularly when the in-focus position cannot be detected.
According to the focusing method of the imaging device of claim 8 of the present invention, the imaging step of converting the light incident through the imaging lens into an electrical signal and acquiring imaging data;
A focus lens position detection step for detecting the current focus lens position;
A focusing range designating step for designating a narrow range near the current focus lens position detected in the focus lens position detecting step as a focusing range from all focusing ranges in which the focus lens can be driven;
A focus lens drive range changing step for changing the drive range of the focus lens in accordance with the focus range designated by the focus range designation step;
A display step of displaying the imaging data and displaying the in-focus range specified by the in-focus range specifying step with respect to the entire in-focus range in which the focus lens can be driven;
A macro mode switching step for switching between a macro mode for shooting a subject at a close distance and a normal mode for shooting a subject at a normal distance;
A zoom step for changing a focal length of the taking lens;
The zoom magnification changing step for changing the zoom magnification by the zoom step;
Changing the range for focus detection according to the zoom magnification set by the zoom magnification changing step,
The focus range designation step is when the macro mode is set by the macro mode switching step, and after performing the focus operation once, the focus range designation for the next and subsequent times is designated. A narrow area nearby,
In the step of changing the focus detection range, when the zoom magnification is changed in the zoom magnification changing step, the driving amount of the focus lens is constant regardless of the changed zoom magnification. by limiting the engagement Asehan circumference as a macro mode for photographing a close distance object, the adapt to the characteristics of the shooting mode and the normal mode, in particular, be adapted to the zoom position in the zoom lens, the zoom meaning When changing the position, regardless of the zoom position, the release time lag is kept constant, effectively achieving an AF operation speed-up and power consumption reduction in the imaging device, effectively preventing failed shooting, In addition, false focusing due to erroneous determination can be prevented, and usability can be improved.

According to the computer-readable recording medium of claim 9 of the present invention,
An imaging procedure for converting incident light through an imaging lens into an electrical signal and acquiring imaging data;
A focus lens position detection procedure for detecting the current focus lens position;
A focusing range designation procedure for designating a narrow range in the vicinity of the current focus lens position detected by the focus lens position detection procedure as a focusing range from the entire focusing range in which the focus lens can be driven;
A focus lens driving range changing procedure for changing the driving range of the focus lens in accordance with the focusing range specified by the focusing range specifying procedure;
A display procedure for displaying the imaging data and displaying the in-focus range specified by the in-focus range specifying procedure for all in-focus ranges that can be driven by the focus lens;
A macro mode switching procedure for switching between a macro mode for shooting a subject at a close distance and a normal mode for shooting a subject at a normal distance;
A zoom procedure for changing the focal length of the taking lens;
The zoom magnification changing procedure for changing the zoom magnification according to the zoom procedure,
And a procedure for changing a focus detection range according to the zoom magnification set by the zoom magnification change procedure,
The focus range designation procedure is when the macro mode is set by the macro mode switching procedure, and after performing the focus operation once, the focus range designation for the next and subsequent times is designated. A narrow area nearby,
In the procedure for changing the focus detection range, when the zoom magnification is changed by the zoom magnification changing procedure, the driving amount of the focus lens is constant regardless of the changed zoom magnification. by limiting the engagement Asehan circumference as, in particular, a macro mode for photographing a close distance object, the adapt to the characteristics of the shooting mode and the normal mode, when changing the zoom position in the zoom lens, the zoom Regardless of the position, the release time lag is kept constant, effectively achieving high-speed AF operation and reducing power consumption in the imaging device, preventing false focusing due to misjudgment, and efficient shooting of failure It can be prevented and the usability can be improved.

Hereinafter, an imaging device according to an embodiment of the present invention will be described in detail with reference to the drawings.
1, 2, 3, and 4 show the configuration of a digital still camera to which an imaging apparatus according to an embodiment of the present invention is applied.
FIG. 1 is a block diagram showing an outline of the entire system configuration of a digital still camera as an imaging system, and FIGS. 2, 3 and 4 schematically show the external configuration of the digital still camera of FIG. They are a top view, a front view, and a rear view, respectively.
A digital camera shown in FIG. 1 includes a photographing lens system 1, a mechanical shutter 2, a CCD (charge coupled device) solid-state imaging device 3, a CDS (correlated double sampling) circuit 4, an AGC (automatic gain control) circuit 5, and an A / D. (Analog-digital) converter 6, timing generator (TG) 7, CCD interface (CCD-I / F) 8, memory controller 9, display output control unit 10, compression processing unit 11, YUV conversion unit 12, resizing processing Unit 13, media interface (media I / F) 14, CPU (central control unit) 15, ROM (read only memory) 16, frame memory (SDRAM) 17, liquid crystal (LCD) display 18, motor driver 19, operation unit 20 The audio output device 21 and the memory card 22 are provided.

The CDS circuit 4, AGC circuit 5, A / D converter 6 and timing generator 7 constitute a front-end (F / E) signal processing unit 31, and a digital signal processing IC (integrated circuit) 32 includes a CCD. An interface 8, a memory controller 9, a display output control unit 10, a compression processing unit 11, a YUV conversion unit 12, a resize processing unit 13, a media interface 14 and a CPU 15 are mounted.
The photographing lens system 1 is an optical system for forming an object optical image on the light receiving surface of the CCD solid-state imaging device 3. The mechanical shutter 2 is inserted on the optical path between the photographic lens system 1 and the CCD solid-state imaging device 3 to open and close the optical path and limit the exposure of the CCD solid-state imaging device 3. The CCD solid-state imaging device 3 converts an optical image incident on the light receiving surface in an exposed state into an electrical signal, temporarily holds it, and transfers and outputs image data.
The CDS circuit 4, the AGC circuit 5, the A / D converter 6, and the timing generator 7 constitute a signal processing unit 31 that processes an output signal from the CCD solid-state imaging device 3 at the front end. The CDS circuit 4 performs correlated double sampling on the output image signal of the CCD solid-state imaging device 3. The AGC circuit 5 adjusts the correlated double sampling output of the CDS circuit 4 to a desired signal level by performing automatic gain control. The A / D converter 6 converts the analog output of the AGC circuit 5 into digital data.

The timing generator 7 includes a VD signal (vertical synchronization drive signal) and an HD signal (horizontal synchronization drive signal) which are synchronization drive signals provided from the CCD interface 8 of a digital signal processing IC (hereinafter referred to as “signal processing IC”) 32. The timing signal is given to the CCD solid-state imaging device 3, the CDS circuit 4, the AGC circuit 5 and the A / D converter 6 in cooperation with the CPU 15, and these are appropriately synchronized.
The signal processing IC 32 stores the digital image data given through the A / D converter 6 of the signal processing unit 31 in the frame memory 17 and performs necessary signal processing such as compression and YUV conversion based on the control of the CPU 15. Storage of the data processed in the signal processing IC 32 in the frame memory 17, display on the LCD display 18 of image data given from the A / D converter 6 or taken out from the frame memory 17, A Memory of digital image data supplied from / D converter 6 or taken out from frame memory 17, YUV conversion and resizing processing, and digital image data taken out from frame memory 17 through media interface 14 Processing such as storage in the card 22 is performed.

  The CCD interface 8 receives digital image data supplied from the A / D converter 6 of the signal processing unit 31 and stores it in the frame memory 17 via the memory controller 9. Under the control of the CPU 15, the memory controller 9 is the original RGB (RAW-RGB) data given through the CCD interface 8, the YUV data YUV converted by the YUV converter 12, the compression processor 11, for example, JPEG (Joint Control is performed for writing to and reading from the frame memory 17 of JPEG data and OSD (on-screen display) image data compressed by the Photographic Experts Group) method. The display output control unit 10 displays the image data read from the frame memory 17 on the LCD display 18 and outputs a TV output for display on an external TV (television) or the like. The compression processing unit 11 compresses image data or the like given from the A / D converter 6 or taken out from the frame memory 17 by a predetermined compression method such as the JPEG method. The YUV converter 12 performs YUV conversion on the image data given from the A / D converter 6 or taken out from the frame memory 17 in accordance with an auto white balance (AWB) control value given from the CPU 15. The resizing processing unit 13 resizes the image data given from the A / D converter 6 or taken out from the frame memory 17. The media interface 14 writes the image data given from the A / D converter 6 or taken out from the frame memory 17 to the memory card 22 under the control of the memory controller 9 and the CPU 15.

That is, the memory controller 9 stores the image data given from the A / D converter 6 in the frame memory 17, takes out the image data from the frame memory 17, and the LCD display 18 through the display output control unit 10. The image data is taken out from the frame memory 17 and compressed by the compression processing unit 11 such as the JPEG method, the YUV conversion by the YUV conversion unit 12, the resizing process by the resize processing unit 13, and the compression and YUV conversion. The data after the resizing process is used for writing to the frame memory 17, and the data is further extracted from the frame memory 17 and used for writing to the memory card 22.
The ROM 16 stores an operation program, data, and the like of the CPU 15, and the CPU 15 executes various processes related to the photographing operation according to the program and data read from the ROM 16. The frame memory 17 is a semiconductor memory such as SDRAM (Synchronous Dynamic Random Access Memory), for example, and stores original RGB data, YUV converted YUV data, JPEG compressed JPEG data, OSD image data, and the like. Store. The LCD display 18 is a display device capable of displaying an image, such as a liquid crystal display device, and is supplied from the A / D converter 6 or taken out from the frame memory 17 and supplied via the display output control unit 10. Is displayed, and further, necessary information is displayed.

  The motor driver 19 drives a lens driving motor (not shown) of the photographing lens system 1 for focusing, zooming, and the like based on the control of the CPU 15 and interlocks with the timing generator 7 for shutter opening / closing operation. Then, a shutter drive motor (not shown) of the mechanical shutter 2 is driven. The operation unit 20 includes a release switch for instructing photographing, a mode switch for switching each mode, and at least a part of operation means such as other switches, keys, levers, and dials. Then, an operation for giving information such as setting instructions and selection instructions to the CPU 15 is performed. The voice output device 21 emits a voice such as an alarm and a voice announcement. The memory card 22 is a small IC memory type recording medium called a small card incorporating a semiconductor non-volatile memory such as a so-called flash memory, and is used as an external recording medium detachable from the digital still camera. For example, it is used by being detachably mounted in a slot provided in a digital still camera. For example, under the control of the CPU 15, the memory card 22 takes out image data compressed by the JPEG method or the like in the frame memory 17 from the frame memory 17 via the memory controller 9 and stores it as a photographing result.

  2 to 4, in the digital still camera, an LCD monitor 18A is disposed on the back surface of the body, and a sub LCD 18B is disposed on the top surface of the body. The LCD monitor 18A and the sub LCD 18B are disposed on the LCD display in FIG. 18 is configured. The LCD monitor 18A mainly displays an image, and the sub LCD 18B mainly displays a film counter, various symbols indicating the date / time and operation state, and the like. A shutter release 201 and a mode dial 202 are disposed on the upper surface of the body. On the back of the body, a wide-angle (WIDE) zoom switch 203, a telephoto (TELE) zoom switch 204, a self-timer / delete switch 205, a menu switch 206, an up / strobe switch 207, a right switch 208, a display switch 209, down A / macro switch 210, a left / image confirmation switch 211, and an OK (OK) switch 212 are provided, and these switches constitute the operation unit 20 in FIG. A power switch 101 is disposed at the lower back of the body, and a memory card / battery cover that covers a memory card 22 such as an SD card and a battery storage unit as a power source is provided on the right side of the body facing the subject. 102 is disposed. On the front surface of the body, a strobe light emitting unit 103, an objective surface of the optical viewfinder 104, a distance measuring unit 105, a remote control (remote control) light receiving unit 106, a lens barrel unit 107 of a photographing lens, and the like are arranged. Further, an eyepiece portion of the optical viewfinder 104, an AF display LED (light emitting diode) 108, and a strobe display LED 109 are disposed on the back side of the body.

  A focus lens position detecting unit for detecting a current focus lens position; a focusing range specifying unit for specifying a narrow range near the current focus lens position detected by the focus lens position detecting unit as a focusing range; Focus lens drive range changing means for changing the focus lens drive range in accordance with the focus range specified by the focus range specifying means, previous focus result storage means for storing the previous focus result, and the focus A warning display that displays a warning if the focus is not obtained from the previous focusing result stored in the previous focusing result storage unit when the range specifying unit is set to specify the focusing range. Means, focus range display means for displaying the current focus range, focus range position for changing the position of the narrow focus range designated by the focus range designation means Further means, focusing range designation releasing means for canceling the setting of the narrow focusing range specified by the focusing range specifying means, macro mode for shooting a subject at a close distance, and normal mode for shooting a subject at a normal distance Macro mode switching means for switching between, a focus range specifying means for enabling a focus range to be specified only when the macro mode is set, a macro mode for shooting a subject at a close distance, and a subject at a normal distance If the focus range is specified by the focus range specifying means when the macro mode switching means switches between the normal mode and the macro mode switching means, the focus range is automatically specified. Means for canceling the designation, zoom means for changing the focal length of the photographic lens, and means for changing the zoom magnification by the zoom means If the in-focus range is designated by the in-focus range designation means when the zoom magnification is changed by the in-focus magnification change means and the zoom magnification change means, the in-focus range is automatically designated. A zoom means for changing the focal length of the photographing lens, a zoom magnification changing means for changing the zoom magnification by the zoom means, and a focus detection according to the zoom magnification set by the zoom magnification changing means. Whether or not to perform re-ranging when the focusing range is not found as a result of focusing operation with a narrow range specified by means for changing the range or focusing range specifying means, if the focal point is not found When the in-focus point cannot be obtained within the narrow range set by the in-focus re-ranging selection unit and the in-focus range specifying unit, When large re-ranging is permitted, means for performing the focusing operation again in a range wider than the set focusing range is realized by the above-described units being controlled by the CPU 15 or the like. .

First, an outline of the operation of this type of digital still camera will be described.
By operating the mode dial 202 shown in FIG. 2 in the operation unit 20 of FIG. 1 and setting the operation mode to the recording mode, the digital still camera is activated in the recording mode. The mode dial 202 is set by the CPU 15 detecting that the state of the mode switch included in the operation unit 20 of FIG. 1 is in the recording mode and controlling the motor driver 19 to control the photographing lens system of the lens barrel unit 107. 1 is moved to a position where photographing is possible. Further, the power is turned on to start the operation of each unit such as the CCD solid-state imaging device 3, the signal processing unit 31, and the LCD display 18.
When the power of each part is turned on, the operation in the finder mode is started. In this finder mode, the light incident on the CCD solid-state image pickup device 3 through the photographing lens system 1 is converted into an electrical signal. In this case, the CDS circuit 4 and the analog RGB signal including analog R, G, and B signals are used. The signals are sent to the A / D converter 6 via the AGC circuit 5 sequentially. Each signal converted into a digital RGB signal by the A / D converter 6 is converted into a YUV signal by the YUV converter 12 in the digital signal processing IC 32 and written into the frame memory 17 by the memory controller 9. The YUV signal is read by the memory controller 9 and output as a TV output via the display output control unit 10 or sent to the LCD display 18 to be displayed on the LCD monitor 18A. This process is usually performed at 1/30 second intervals and is displayed every 1/30 seconds, so that a finder mode display as a so-called electronic finder is displayed.

Also, an AF evaluation value indicating the degree of focus on the screen, an AE (automatic exposure) evaluation value for detecting subject brightness, and a subject color are obtained from the digital RGB signal captured in the CCD interface 8 of the digital signal processing IC 32. The detected AWB evaluation value is calculated. These data are read as feature data to the CPU 15 and used for each of AE, AF, and AWB processes. The AF evaluation value is created by, for example, an output integrated value of a high frequency component extraction filter or an integrated value of a luminance difference between adjacent pixels. When in the in-focus state, the edge portion of the subject is clear, so the high frequency component is the highest. By utilizing this, at the time of focus detection operation by AF, AF evaluation values at various focus lens positions are acquired, and AF control is executed with the point where the maximum is obtained as the focus position. The AE evaluation value and the AWB evaluation value are created from the integrated values of the R, G, and B signals. For example, the screen is equally divided into 256 areas, and an RGB integrated value, that is, an integrated value is calculated for each. The CPU 15 reads the RGB integrated values, and in AE, calculates the luminance of each area, and determines the control value of AE from the luminance distribution. In AWB, an AWB control value that matches the color of the light source is determined from the RGB distribution.
The AE and AWB processes are continuously performed during the finder mode.

  When the shutter release (button) 201 in FIG. 2 is operated, an AF operation that is a focus position detection and a still image recording process are performed. When the shutter release 201 is pressed, a still image shooting start signal is taken into the CPU 15 from the operation unit 20 of FIG. 1, and the CPU 15 drives the shooting lens system 1 via the motor driver 19 in synchronism with the frame rate to climb the mountain. Execute AF. When the in-focus range is the entire region from infinity to close, the focus lens moves to each focus position from close to infinity, or from infinity to close, and each frame created by the digital signal processing IC 32 The CPU 15 reads the AF evaluation value at (= each focus position). The focus lens is moved to the in-focus position with the point at which the AF evaluation value at each focus position is maximized as the in-focus position. An analog RGB signal taken out from the CCD solid-state imaging device 3 after the AF is completed is converted into a digital RGB signal and stored in the frame memory 17 via the digital signal processing IC 32. The digital RGB signal is read again by the digital signal processing IC 32, converted into YUV data, and written back to the frame memory 17.

  At the time of capturing a still image, YUV converted image data is sent to the compression processing unit 11 including an image compression / decompression circuit in the digital signal processing IC 32. The YUV data sent to the compression processing unit 11 is compressed and written back to the frame memory 17. The compressed data in the frame memory 17 is read out via the digital signal processing IC 32 and stored in a data storage memory such as the memory card 22.

Next, operations that are characteristic of the digital still camera according to this embodiment of the present invention will be described in detail.
First, as a first operation example, a case where the AF scan range is limited only in the macro mode will be described.

Table 1 shows an example of the number of in-focus positions detected with respect to the zoom position when the close range of 1 to 30 cm is set to the macro mode and the range farther than that is set to the normal mode. When the entire area is scanned in the macro range, the number of points ( number of steps) becomes very large. For example, in the case of 120 points, the screen update interval in the finder mode is 1/30 seconds, and scanning is performed by shifting one point for each frame. A four-second AF scan is required. Therefore, the state of the subject to be photographed may change. As a countermeasure for this problem, the focusing time is shortened by limiting the focusing range (scanning area).
When the lower / macro switch 210 in FIG. 4 is pressed in the finder mode state, the macro mode is set. FIG. 5 shows an example of a display screen of the LCD monitor 18A when the macro mode is set. The number of recording pixels is set to 2048 × 1536, for example. The display of the horizontal bar B1 at the bottom of the screen is the current focus position. Immediately after setting the macro, the focus is at 30 cm.

The shutter release 201 shown in FIG. 2 is a two-stage switch. When the shutter release 201 is pressed halfway, a focusing operation is performed. When the shutter release 201 is further pressed, a recording operation is performed. FIG. 6 shows a display screen after photographing at least once or when the shutter release 201 is half-pressed. Since focusing was performed around 10 cm, “◯” indicating the focusing position J1 of the focus lens has moved to around 10 cm.
There are several methods for realizing such current focus lens position detection. For example, when the focus lens is driven by a pulse motor, the reference point is detected as a reset operation when starting the camera. The current position can be detected from the number of moving pulses thereafter. It is also possible to use a resistor plate showing a different resistance value depending on the position of the focus lens, and to detect the position based on the output of the resistor plate.
When the OK switch 212 is pressed in the state of FIG. 6, the vicinity of the current focus position becomes the next AF scan target range. FIG. 7 shows a display after the OK switch 212 is pressed, and the range indicated by the arrow R1 is the next AF scan target range.

FIG. 8 is a screen display of the change result when the setting range is changed. The setting range is changed by the left and right buttons, that is, the left / image confirmation switch 211 and the right switch 208 shown in FIG. When the left and right buttons are pressed while the AF scan range is set as shown in FIG. 7 or FIG. 8, the arrow R1 indicating the AF scan range on the screen moves. This position becomes the scan range at the next AF.
Here, when the photographing operation is executed by pressing the shutter release 201 deeply, the AF operation is executed prior to recording. If the scan range is limited to 15 steps, for example, the screen update is 1/30 second, so the time required for AF can be reduced to 0.5 seconds, and the shutter time lag can be greatly reduced. . In addition, since the time and distance (rotation amount) for operating the focus motor can be reduced, power consumption can be reduced.

When the OK switch 212 is pressed in the state of FIGS. 7 and 8, the AF scan range setting is canceled and the screen returns to the screen of FIG. When the down / macro switch 210 is pressed again in the macro mode, the normal shooting mode as shown in FIG. Even when the scan range is set as shown in FIGS. 7 and 8, the range setting is canceled when the macro mode is turned off. When the OK switch 212 is pressed in the state shown in FIG. 5 which is the initial state set to the macro mode, a warning screen as shown in FIG. 9 is displayed. This is to avoid limiting the scan range without knowing the distance since the focusing operation has never been performed after the macro mode is set.
Next, a case where the AF scan range is limited in the normal shooting mode will be described as a second operation example. As shown in Table 1, when AF scanning is performed on the entire area, the number of steps at the wide-angle end (WIDE end) and the telephoto end (TELE end) of the zoom are greatly different. It will be different. Therefore, when shooting a moving object, it is necessary to take into account that the release time lag changes depending on the zoom position. If the distance is roughly known, the AF time can be shortened by limiting the scan range to a certain range.
For example, if the movement amount of the focus lens is made constant, the release time lag can be made constant regardless of the zoom position.

FIG. 10 shows a display when the power switch 101 is turned on in the recording mode and the finder mode is started. The zoom position at the start is the wide-angle end. The display of the vertical bar B2 on the left is a bar display indicating the zoom position, and it can be seen that the display is activated at the wide-angle end.
When the OK switch 212 is pressed in the screen display state of FIG. 10, the display is switched to that shown in FIG. The display of the horizontal bar B1 at the bottom of the screen is an information display regarding the focus. The “◯” mark indicates the current focus lens position J1, and the arrow R1 indicates the scan range at the next AF.
At the wide-angle end as shown in FIG. 11, since there are only 10 focus detection positions as shown in Table 1, 7 points are set as a detection range. Since 7 points acquire a high-pass filter output of 7 frames, the time required for AF scanning is about 0.25 seconds. FIG. 12 shows the zoom moved to the telephoto end. When the zoom magnification change is set by the zoom switches 203 and 204 in FIG. 2, the CPU 15 drives the motor driver 19 to move the zoom lens. While the zoom switch 203 or 204 is being pressed, the zoom position J2 moves in the requested direction, and the zoom position J2 indicated by “●” moves to the zoom bar B2 as shown in FIG.

Here, in order not to greatly change the AF scan time depending on the zoom position, it is necessary to set the AF scan point to 7 points. However, the entire scan range at the telephoto end is 70 points, which is too narrow. For this reason, 10 points are set here. When the entire area is scanned, the scan time is approximately 2.3 seconds at 70 × 1/30. On the other hand, by limiting to 10 points, it can be shortened to about 0.33 seconds.
By doing so, it is possible to shorten the AF focus detection operation time and realize a system with little difference in time lag depending on the zoom position. In addition, since the operation amount of the mechanism portion can be reduced, reduction of power consumption can be realized. Furthermore, since the focus range is clearly indicated on the screen, it can be easily confirmed whether the range intended by the photographer is the focus target. Since it is known in advance that the image is in focus within the displayed range, there is no need to worry about focusing on the front wire mesh even when shooting through a wire mesh, and it is possible to realize AF with few failures. In addition, when the okay switch 212 is pressed again in the state of FIGS. 11 and 12, the setting of the focus range is canceled and the state returns to the state shown in FIG.

In each of the above-described examples, the number of AF focusing points is determined so that the scanning time is approximately the same. However, there is a method for determining the number of points so that the focusing distance is within a certain range. For example, when the range is specified so as to cover 50% of the entire area, 5 points are in-focus points at the zoom wide-angle end and 35 points at the zoom telephoto end.
In the above description, the method of changing the subject distance range for keeping the time constant by making the moving range of the focus lens the same as the number of in-focus points increases or decreases as the zoom position changes, and the subject The method for changing the moving range of the focus lens while keeping the distance range constant has been described. However, depending on the zoom magnification, the difference in the number of points at the wide-angle end and the telephoto end may be even greater. Therefore, when the zoom magnification is changed in a state where the focus range is specified as shown in FIGS. 11 and 12, the focus in-focus range specification may be automatically canceled.
In addition, as a result of performing AF in a scan range limited to a narrow range, if focus is not obtained, the range is expanded even if time is taken, for example, the entire area is scanned to detect the focus position, It may be possible to set whether to limit only within the set range. If the setting is made to expand the range, the time will be longer, but it is possible to automatically respond to changes in the subject and reduce shooting failures. However, when it is known in advance that the in-focus point is within the set range, the time for scanning with the range expanded is wasted, and extra power is consumed. Furthermore, if the entire area is scanned and focused at a point outside the limited range, the intended shooting will not be performed. Therefore, it is desirable to be able to select whether or not to expand the range when a focal point is not found within the range.

In other words, as a result of performing the focusing operation in a state where a narrow range is designated, a means for selecting whether or not to perform re-ranging by expanding the ranging range when the in-focus point cannot be found is provided and set. If the in-focus point cannot be obtained within the narrow range, and enlarged re-ranging is permitted, the focus operation is performed again in a range wider than the set focus range. To do.
The imaging apparatus of the present invention can be realized by a versatile apparatus using a computer system instead of being configured as a dedicated digital still camera or the like. For example, by installing the program from a recording medium such as a flexible disk or a CD-ROM storing a program for executing the above-described operation in a computer system, an apparatus for executing the above-described processing may be constructed. Good. By installation, the program is stored in a medium such as a hard disk in the computer system, configures the above-described apparatus, and is used for execution. In addition, the program may be registered in an FTP (File Transfer Protocol) server provided on a communication network such as the Internet and distributed to the FTP client via the network. The program may be registered in an electronic bulletin board (BBS: Bulletin Board System) or the like of a communication network, and distributed through the network. Then, by starting this program and executing it under the control of an OS (Operating System), the above-described processing can be achieved. Furthermore, the above-described processing can also be achieved by starting and executing a program while transferring it via a communication network.

1 is a block diagram schematically showing an overall system configuration of a digital still camera according to an embodiment of an imaging apparatus of the present invention. It is a top view which shows typically the external appearance structure of the digital still camera of FIG. It is a front view which shows typically the external appearance structure of the digital still camera of FIG. FIG. 3 is a rear view schematically showing an external configuration of the digital still camera of FIG. 2. It is a figure which shows typically the display screen immediately after the macro setting of the LCD monitor for demonstrating the 1st specific example of operation | movement of the digital still camera of FIG. It is a figure which shows typically the display screen in macro mode after AF execution of the LCD monitor in macro mode for demonstrating the 1st specific example of operation | movement of the digital still camera of FIG. It is a figure which shows typically the display screen after the focus range specification of the LCD monitor in macro mode for demonstrating the 1st specific example of operation | movement of the digital still camera of FIG. It is a figure which shows typically the display screen after the focus range change of the LCD monitor in macro mode for demonstrating the 1st specific example of operation | movement of the digital still camera of FIG. It is a figure which shows typically the warning display screen of the LCD monitor in macro mode for demonstrating the 1st specific example of operation | movement of the digital still camera of FIG. It is a figure which shows typically the display screen of an LCD monitor when the focusing range in the normal mode for demonstrating the 2nd specific example of operation | movement of the digital still camera of FIG. 1 is not designated. It is a figure which shows typically the display screen of a LCD monitor when the focusing range is designated by the wide-angle end side in the normal mode for demonstrating the 2nd specific example of operation | movement of the digital still camera of FIG. It is a figure which shows typically the display screen of a LCD monitor when the focusing range is designated by the telephoto end side in the normal mode for demonstrating the 2nd specific example of operation | movement of the digital still camera of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shooting lens system 2 Mechanical shutter 3 CCD (charge coupled device) solid-state image sensor 4 CDS (correlated double sampling) circuit 5 AGC (automatic gain control) circuit 6 A / D (analog-digital) converter 7 Timing generator ( TG)
8 CCD interface (CCD-I / F)
9 Memory Controller 10 Display Output Control Unit 11 Compression Processing Unit 12 YUV Conversion Unit 13 Resize Processing Unit 14 Media Interface (Media I / F)
15 CPU (Central Control Unit)
16 ROM (Read Only Memory)
17 Frame memory (SDRAM)
18 Liquid crystal (LCD) display 18A Liquid crystal (LCD) monitor 18B Sub liquid crystal (LCD)
DESCRIPTION OF SYMBOLS 19 Motor driver 20 Operation part 21 Audio | voice output apparatus 22 Memory card 31 Front end (F / E) signal processing part 32 Digital signal processing IC (integrated circuit)
201 Shutter release (button)
202 Mode dial 203 Wide-angle (WIDE) zoom switch 204 Telephoto (TELE) zoom switch 205 Self-timer / deletion switch 206 Menu switch 207 Up / Strobe switch 208 Right switch 209 Display switch 210 Down / Macro switch 211 Left / Image confirmation switch 212 OK switch

Claims (9)

In an imaging device having an automatic focusing function,
Imaging means for converting light incident through the taking lens into an electrical signal and acquiring imaging data;
Focus lens position detection means for detecting the current focus lens position;
A focusing range designating unit for designating a narrow range in the vicinity of the current focus lens position detected by the focus lens position detecting unit as a focusing range from the entire focusing range in which the focus lens can be driven;
A focus lens drive range changing unit that changes a drive range of the focus lens in accordance with the focus range specified by the focus range specifying unit;
Display means for displaying the imaging data and displaying a focus range designated by the focus range designation means for all focus ranges that can be driven by the focus lens;
Macro mode switching means for switching between a macro mode for photographing a subject at a close distance and a normal mode for photographing a subject at a normal distance;
Zoom means for changing the focal length of the taking lens;
Zoom magnification changing means for changing the zoom magnification by the zoom means;
Means for changing a focus detection range according to the zoom magnification set by the zoom magnification changing means,
The focus range designation means is set to the macro mode by the macro mode switching means, and after performing the focus operation once, the focus range designation for the next and subsequent times is designated. A narrow area nearby,
The means for changing the focus detection range is such that, when the zoom magnification is changed by the zoom magnification changing means, the driving amount of the focus lens is constant regardless of the changed zoom magnification. imaging apparatus characterized by limiting the alloy Asehan enclosed as. A previous focus result storage means for storing the previous focus result;
When the focus range is specified by the focus range specification means, if the focus is not obtained from the previous focus result stored in the previous focus result storage means, a warning is displayed. The imaging apparatus according to claim 1, further comprising a warning display unit that performs the warning display. Focusing range position changing means for changing the position of the narrow focusing range specified by the focusing range specifying means;
Operating means for operating the imaging device,
The imaging apparatus according to claim 1, wherein the focus range position changing unit changes the position of the narrow focus range by an operation of the operation unit.   The imaging according to any one of claims 1 to 3, further comprising a focusing range designation canceling unit that cancels the setting of a narrow focusing range specified by the focusing range specifying unit. apparatus. The macro mode switching means for switching between a macro mode for photographing a subject at a close distance and a normal mode for photographing a subject at a normal distance;
And a means for automatically canceling the designation of the focus range when the focus range is designated by the focus range designation means when the macro mode switching means is switched. The imaging device according to any one of claims 1 to 4, wherein: Zoom means for changing the focal length of the taking lens;
Zoom magnification changing means for changing the zoom magnification by the zoom means;
Means for automatically canceling the designation of the focus range if the focus range is designated by the focus range designation means when the zoom magnification is changed by the zoom magnification change means; The imaging apparatus according to any one of claims 1 to 5, further comprising: As a result of performing the focusing operation in a state where a narrow range is designated by the focusing range designation means, an enlargement for selecting whether to perform re-ranging by enlarging the ranging range when the in-focus point is not found. Re-ranging selection means;
It is set when the in-focus point is not obtained within the narrow range set by the in-focus range specifying means and when the enlarged re-ranging selection is permitted by the enlarged re-ranging selection means. The imaging apparatus according to claim 1, further comprising: a unit that performs the focusing operation again in a range wider than the focusing range. In the focusing method of the imaging device,
An imaging step of converting light incident through the taking lens into an electrical signal and acquiring imaging data;
A focus lens position detection step for detecting the current focus lens position;
A focusing range designating step for designating a narrow range near the current focus lens position detected in the focus lens position detecting step as a focusing range from all focusing ranges in which the focus lens can be driven;
A focus lens drive range changing step for changing the drive range of the focus lens in accordance with the focus range specified by the focus range specifying step;
A display step of displaying the imaging data and displaying the in-focus range specified by the in-focus range specifying step with respect to the entire in-focus range in which the focus lens can be driven;
A macro mode switching step for switching between a macro mode for shooting a subject at a close distance and a normal mode for shooting a subject at a normal distance;
The zoom step of changing a focal length of the photographing lens;
The zoom magnification changing step for changing the zoom magnification by the zoom step;
Changing the range for focus detection according to the zoom magnification set by the zoom magnification changing step,
The focus range designation step is when the macro mode is set by the macro mode switching step, and after performing the focus operation once, the focus range designation for the next and subsequent times is designated. A narrow area nearby,
In the step of changing the focus detection range, when the zoom magnification is changed in the zoom magnification changing step, the driving amount of the focus lens is constant regardless of the changed zoom magnification. focusing method of imaging apparatus, characterized in that to limit the focus Asehan enclosed as. On the computer,
An imaging procedure for converting incident light through an imaging lens into an electrical signal and acquiring imaging data;
A focus lens position detection procedure for detecting the current focus lens position;
A focusing range designation procedure for designating a narrow range in the vicinity of the current focus lens position detected by the focus lens position detection procedure as a focusing range from the entire focusing range in which the focus lens can be driven;
A focus lens driving range changing procedure for changing the driving range of the focus lens in accordance with the focusing range specified by the focusing range specifying procedure;
A display procedure for displaying the imaging data and displaying the in-focus range specified by the in-focus range specifying procedure for all in-focus ranges that can be driven by the focus lens;
A macro mode switching procedure for switching between a macro mode for shooting a subject at a close distance and a normal mode for shooting a subject at a normal distance;
The zoom procedure for changing the focal length of the taking lens;
The zoom magnification changing procedure for changing the zoom magnification according to the zoom procedure,
And a procedure for changing a focus detection range according to the zoom magnification set by the zoom magnification change procedure,
The focus range designation procedure is when the macro mode is set by the macro mode switching procedure, and after performing the focus operation once, the focus range designation for the next and subsequent times is designated. A narrow area nearby,
In the procedure for changing the focus detection range, when the zoom magnification is changed by the zoom magnification changing procedure, the driving amount of the focus lens is constant regardless of the changed zoom magnification. a computer-readable recording medium characterized by limiting the alloy Asehan enclosed as.

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