JP4355847B2 - Camera focus information display apparatus and method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an in-focus information display apparatus for a camera and a method thereof, and more particularly to an in-focus information display apparatus for a camera capable of displaying an in-focus direction or an in-focus state and notifying a user when setting manual focus. Regarding the method.
[0002]
[Prior art]
Conventionally, in electronic cameras and video cameras, the user manually focuses on the desired position. Together It is known that the focus position can be moved by turning a manual focus (MF) ring so that the focus position can be adjusted. The user adjusts the focus while confirming the image captured by the image sensor on the monitor of the EVF (Electronic View Finder) or LCD (Liquid Crystal Display), but it is focused by judging how the monitor image is blurred. Even if you try to do this, the focus lens moves in the opposite direction to the in-focus position because it is not known whether the in-focus position is nearer or far away. Z There was a problem with the problem. In addition, with the recent increase in the number of pixels of the image sensor, there is a problem that it is difficult to determine whether or not the movie image is in focus.
[0003]
For this purpose, focus information is detected based on the video signal obtained by imaging the subject, a pattern signal indicating the focus information is generated based on the detected information, and the focus information is determined based on the pattern signal. Japanese Unexamined Patent Publication No. 5-308552 discloses a camera-integrated VTR that displays a pattern to be displayed during manual focus control.
[0004]
Also, the lens focus that can reduce the time that the user spends focusing the focus lens on the subject by displaying the direction in which the focus lens should move using the gradation ratio corresponding to the position of the focus lens Japanese Patent Application Laid-Open No. 6-319073 discloses a status display device and a lens focus adjusting device having the same.
[0005]
[Problems to be solved by the invention]
However, with conventional cameras, the focus lens must be constantly moved (wobbled) in order to adjust the in-focus state, so that the in-focus direction must be known. Had a problem of increasing.
[0006]
Also, since the focus direction is displayed by comparing the data before moving the focus lens with the data after the focus lens is moved, if the output of the focus information detection means changes due to camera shake or subject change, There was a problem of displaying the in-focus direction.
[0007]
The present invention has been made in view of such circumstances, and finely controls the display of focus information that is automatically displayed in the manual focus mode, such as reducing the display of erroneous focus information due to subject changes or camera shake. As a result, it is possible to provide a focusing information display device for a camera and a method thereof in which it is easy to check and adjust the imaging position by manual focus.
[0008]
[Means for Solving the Problems]
To achieve the purpose The focusing information display device according to the first aspect of the present invention In an in-focus information display device for a camera that drives a focus lens based on an operation of a focus operation member, an imaging unit that forms a subject image and outputs an imaging signal, and an imaging signal output by the imaging unit The focus information detecting means for detecting the focus information, the display means for displaying the focus information based on the detection output of the focus information detecting means, the focus operation member is not operated, and the Control means for changing the display of the focus information displayed on the display means when the detection output of the focus information detection means changes when the focus information is displayed on the display means. It is a feature.
[0009]
Also, In-focus information display device according to second aspect of the present invention In an in-focus information display device for a camera that drives a focus lens based on an operation of a focus operation member, an imaging unit that forms a subject image and outputs an imaging signal, and an imaging signal output by the imaging unit The focus information detecting means for detecting the focus information, the display means for displaying the focus information based on the detection output of the focus information detecting means, and the luminance of the subject based on the imaging signal output by the imaging means. When the detection output of the luminance information detection means changes when the focus information is detected when the focus operation member is not operated and the focus information is displayed on the display means, And control means for changing the display of the focusing information displayed on the display means.
[0010]
That is, the present invention does not perform a wobbling operation for knowing the in-focus direction in order to reduce power consumption. The squid, Or, since the operation is limited, when the focus operation member is not operated (that is, when the focus lens is not moved), it is impossible to know the in-focus direction with respect to the latest subject. Therefore, when it is considered that the subject has changed when the focus lens is not moving (that is, when the detection output of the focus information detecting means changes without moving the focus lens ( First aspect ) Or when the detection output of the luminance information detection means changes ( Second aspect )), The display content of the display means is changed so that an incorrect in-focus direction or the like is not displayed. The focusing information display device according to the third aspect of the present invention is: The display of the focusing information displayed on the display means is erased.
[0011]
To achieve the above purpose The focus information display device according to the fourth aspect of the present invention In a focusing information display device for a camera that drives a focus lens based on an operation of a focus operation member, an imaging unit that forms a subject image and outputs an imaging signal, and a position grasp that grasps a lens position of the focus lens Means, focus information detecting means for detecting focus information based on the output imaging signal in association with three or more lens positions detected by the position grasping means, and the focus information detected by the focus information detecting means. Storage means for storing focus information; means for determining a lens position at which the subject image is focused on the imaging means based on the information stored in the storage means; and the obtained lens position and the current lens position of the focus lens; And a display means for displaying the focus information based on the detection output detected by the focus information detection means.
[0012]
According to the present invention, since the in-focus information stored in association with three or more lens positions is used, a more accurate in-focus direction and in-focus state can be detected, and manual confirmation and adjustment of the imaging position is possible. Becomes easy.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a camera focus information display apparatus and method according to the present invention will be described below in detail with reference to the accompanying drawings.
[0014]
FIG. 1 is a front perspective view of an electronic camera according to the present invention.
[0015]
According to the figure, the electronic camera 10 is provided with a variable-magnification lens 12 for picking up a subject image, and a position at which the subject image is formed on an image pickup means which is rotatably provided on the outer periphery of the lens 12 and will be described later. A focus ring 14 (focus operation member) that is manually adjusted by the user and a release button 16 that instructs imaging when the user images the subject are provided.
[0016]
FIG. 2 is a rear perspective view of the electronic camera 10.
[0017]
According to the figure, the electronic camera 10 includes a display means 18 for displaying information about an image to be picked up and an in-focus position of the image, a zoom lever 20 for adjusting the angle of view of the picked up image to TELE / WIDE, AF / An MF selector switch 22 is provided.
[0018]
The AF / MF change-over switch 22 adjusts the adjustment mode of the image formation position at which the subject image is formed on the imaging means of the electronic camera 10, or the user himself / herself adjusts the image formation position to a desired image formation position. This switch is set to manual focus mode.
[0019]
The user operates the zoom lever 20 while confirming the through image being photographed displayed on the display means 18, determines the angle of view in the direction of WIDE, TELE, and the like and shoots. The user can switch between the auto focus mode and the manual focus mode by pressing the AF / MF switch 22. When the manual focus mode is set, the user turns the focus ring 14 while focusing on a desired subject while viewing the through image displayed on the display unit 18. In the present invention, in the manual focus mode, the focus information is correctly displayed as shown in FIG. 4 to be described later, so that the user can adjust the focus more accurately and easily.
[0020]
FIG. 3 shows a block diagram of a signal processing system of the electronic camera.
[0021]
According to the figure, the lens 12 of the electronic camera 10 is provided with a variable power lens 24, a focus lens 26, and an aperture 28, and an imaging means 30 constituted by a solid-state imaging device or the like behind the imaging lens 30 and imaging. An image sensor driving circuit 31 that generates a timing pulse for controlling the means 30 is arranged. The image signal output from the image pickup means 30 passes through the image pickup circuit 32 (executes processing such as sample hold and analog gain control), is converted into digital data by the A / D converter 34, and is sent to the bus 36 (data Bus and address bus).
[0022]
The bus 36 includes a memory 38 that is a storage unit capable of storing one or a plurality of focusing information and luminance information, and an AE detection unit 40 (luminance information detection unit) that detects the brightness of the captured image. AF detection means 42 (focus information detection means) that calculates an AF evaluation value that is focus information by detecting a luminance component of the captured image, and a display that displays information regarding the captured image and the focus position of the image The means 18, a recording medium 44 such as an external storage device for recording information such as images, and a control means 46 (CPU) for controlling the entire electronic camera 10 are connected.
[0023]
Further, the electronic camera 10 includes a motor 48 for driving the variable power lens 24 of the lens 12, a zoom driving means 50 for driving the motor 48, and a zoom position detecting means for detecting the variable power position of the variable power lens 24. 52, a motor 54 for driving the focus lens 26, a focus driving means 56 for driving the motor 54, an HP sensor 58 for detecting the focus origin position of the focus lens 26, and an opening degree of the diaphragm 28. A motor 60, a diaphragm control means 62 for driving the motor 60, and an HP sensor 64 for detecting the origin position of the diaphragm 28 are provided.
[0024]
Further, the operation signal of the zoom lever 20 and the operation signal of the AF / MF changeover switch 22 are input to the control means 46 of the electronic camera 10, and these operation states can be recognized. . An operation signal for the focus ring 14 is input to the operating state detection unit 66, and an operation state in which the user manually rotates the focus ring 14 to drive the imaging position (during operation) and the focus ring 14 is rotated. A non-operating state (non-operating state) that is not moved is determined and input to the control means 46. Further, instead of the operating state detecting unit 66 determining the operating state and non-operating state of the focus ring 14, the operating state of the focus ring 14 is input to the control unit 46, and the controlling unit 46 determines whether the operating state of the focus ring 14 is inactive You may make it implement the process which judges an operation state.
[0025]
Further, the control means 46 (including the function of the aperture amount detection means) controls the drive of the zoom lens 24 and the zoom position, the drive control of the focus lens 26 and the focus position (including the function of the position grasping means), Processing such as drive control of the aperture 28 and aperture amount detection is performed.
[0026]
Hereinafter, a method of manually adjusting the imaging position using the electronic camera 10 according to the present invention will be described.
[0027]
When the user presses the AF / MF switch 22, the control means 46 switches the focusing mode of the electronic camera 10 to the manual focus mode. The operating state detection means 66 constantly monitors the operating state of the focus ring 14 to detect whether or not the focus ring 14 is operated, and when it is operated, the rotation direction and rotation of the focus ring 14 are detected. The speed, rotation amount, etc. are detected and the information is output to the control means 46.
[0028]
The control means 46 that has received the operating state of the focus ring 14 outputs a drive signal to the focus drive means 56, moves the focus drive motor 54 (stepping motor or DC motor, etc.), and moves the focus lens 26 at a predetermined speed. Alternatively, the imaging position is adjusted by driving to the position. In the above description, the embodiment has been described in which the operation state detection unit 66 detects the rotation of the focus ring 14 and controls the focus lens 26 based on the detected operation state. However, the present invention is not limited thereto. However, the object of the present invention can be achieved even with a focus lens driving method including a mechanism in which the rotation amount of the focus ring 14 is directly transmitted to the focus lens 26 when the manual focus mode is set.
[0029]
The control means 46 controls the imaging means 30 via the imaging element drive circuit 31, performs A / D conversion on the output from the imaging means 30 and fetches it into the memory 38, or displays a moving image on the display means 18. Do. The AF detection means 42 reads the image data output from the A / D converter 34 and temporarily stored in the memory 38, and extracts the high-frequency component of the luminance of the image divided into one or a plurality of regions. Then, the average of the contrast of each area or a predetermined area is aggregated and output to the control means 46 as an AF evaluation value.
[0030]
The AE detection means 40 reads the image data stored in the memory 38 and extracts the luminance component of the image divided into one or a plurality of areas. Then, the luminance level of the subject is acquired by integrating each region or a predetermined region, and is output to the control means 46 as an AE evaluation value. The control means 46 calculates an exposure force such as an aperture value and a shutter speed necessary for imaging based on the AE evaluation value, and outputs an exposure force setting command to each peripheral device.
[0031]
FIG. 4 shows a display example of the focus display displayed on the display means.
[0032]
According to the figure, the display means 18 has a focus information display 70 for notifying the user of the focus state, a “P” display indicating that the exposure mode of shooting is the program mode, and a shutter at the time of shooting. A speed display “500”, an aperture value display “F2.8”, and the like are displayed.
[0033]
As the focus information display 70, a distance display 72 for notifying the user that the current focus lens 26 is located farther than the subject image, and the current focus lens 26 image position is the subject image. An in-focus display 74 for notifying the user that it is within the range including the depth of field, and a proximity for notifying the user that the current focusing position of the focus lens 26 is closer to the subject image. A display 76 and in-focus position determination impossible displays 78 and 80 for notifying the user that the in-focus position of the subject cannot be calculated correctly due to the influence of the color, brightness, shape, pattern, etc. of the subject are shown.
[0034]
Each of these displays can be displayed superimposed on the captured image by writing the image displayed in FIG. 4 in a memory provided in the display means 18. Further, display superimposition can be realized by providing an OSD (On Screen Display) circuit (not shown) and synthesizing with an analog signal.
[0035]
FIG. 5 shows the relationship between the focus position in a certain subject and the acquired AF evaluation value.
[0036]
In the example shown in the figure, since the AF evaluation value is large in the range where the focus position is “Z”, it can be estimated that the main subject exists in the range “Z”. Assume that the user sets the adjustment mode of the imaging position of the electronic camera 10 to the manual focus mode, and stops the rotation of the focus ring 14 at the focus position “L”. Then, the operating state detecting unit 66 detects the non-operating state of the focus ring 14 and outputs the non-operating information to the control unit 46.
[0037]
At this time, if the control means 46 determines that the AF evaluation value tends to decrease with respect to the focus position within a small range of “ΔL” immediately before stopping at the focus position “L”, the control means 46 matches the image formation position. Since it is determined that the object is located farther than the focal position, a distant display 72 is displayed on the display means 18 to notify the user to that effect. The user can determine the in-focus direction based on the displayed in-focus information and can be used as a reference during imaging.
[0038]
A case where the user rotates the focus ring 14 and stops the focus ring 14 at the focus position “M” will be described. At this time, if the control means 46 determines that the increase rate of the AF evaluation value with respect to the focus position is within the minute range of “ΔM” immediately before stopping at the focus position “M” and is near the peak position, the control means 46 The means 46 determines that the in-focus position is in the vicinity of “M”, displays the in-focus display 74 on the display means 18 and notifies the user to that effect.
[0039]
A case where the user rotates the focus ring 14 and stops the focus ring 14 at the focus position “N”, for example, will be described. At this time, if the control means 46 determines that the AF evaluation value tends to increase with respect to the focus position within a small range of “ΔN” immediately before stopping at the focus position “N”, the control means 46 determines that the imaging position is in focus. Since it is determined that it exists closer to the position, a near display 76 is displayed on the display means 18 to notify the user to that effect. The user can determine the in-focus direction based on the displayed in-focus information and can be used as a reference during imaging.
[0040]
The focus information display 70 once displayed is erased based on a change in AF evaluation value output from the AF detection means 42 or a change in AE evaluation value output from the AE detection means 40. Generally, when the AF evaluation value fluctuates or the AE evaluation value fluctuates, there is a high possibility that the subject has moved relative to the electronic camera 10 and the subject has changed. 70 may be deleted.
[0041]
Further, as described above, instead of erasing the focus information display 70 once displayed based on the fluctuation of the AF evaluation value output by the AF detection means 42 or the fluctuation of the AE evaluation value output by the AE detection means 40, it will be described later. The “wobbling” operation is performed one or more times to acquire in-focus information, the new in-focus direction or in-focus state is displayed, and the in-focus information displayed on the display unit 18 is changed. You may do it.
[0042]
For example, when the focus information display 70 or the like is displayed on the display unit 18 in the manual focus mode, the control unit 46 changes the AF evaluation value output from the AF detection unit 42 or the AE output from the AE detection unit 40. Assume that a change in the evaluation value is detected. The control unit 46 that has detected the variation in the evaluation value instructs the focus driving unit 56 to perform a “wobbling” operation for driving the minute range focus lens 26 one or more times depending on whether or not the “wobbling” operation can be performed. To do. When this “wobbling” operation is performed, the image forming position adjustment mode of the electronic camera 10 is a manual focus mode in which the user directly adjusts the focus position, but in order to notify the user of the in-focus direction. The “wobbling” operation of the focus lens 26 is automatically performed one or more times, and the process of searching for the in-focus direction is performed with reference to the AF evaluation value. In this case, the control unit 46 functions as an imaging position driving unit that automatically drives the imaging position.
[0043]
For example, when the “wobbling” operation is performed at the focus position “L”, the “wobbling” operation is performed within a range of “ΔL”, for example. If the AF evaluation value detected at this time tends to decrease with respect to the focus position, the control means 46 determines that the imaging position exists farther than the in-focus position, and displays the far display 72 on the display means 18. Notify the user to that effect. The user can determine the in-focus direction based on the displayed in-focus information and can be used as a reference during imaging. If the user wants to change the imaging position, the focus ring 14 is rotated as it is to adjust the imaging position to a desired position. The amount of rotation of the focus ring 14 at this time is detected by the operating state detection unit 66, and the control unit 46 controls the focus position of the focus lens 26 based on the detected operation state.
[0044]
Further, when the “wobbling” operation is performed at the focus position “M”, the “wobbling” operation is performed within a range of “ΔM”, for example. If it is determined that the AF evaluation value detected at this time is in the vicinity of the peak position related to the focus position, the control means 46 determines that the in-focus position exists in the vicinity of “M” and displays the in-focus display 74 on the display means 18. And notify the user to that effect.
[0045]
Further, when the “wobbling” operation is performed at the focus position “N”, the “wobbling” operation is performed within a range of “ΔN”, for example. If the AF evaluation value detected at this time has an increasing tendency with respect to the focus position, the control means 46 determines that the in-focus position is closer to the electronic camera 10 and displays the near display 76 on the display means 18. Notify the user to that effect. The user can determine the in-focus direction based on the displayed in-focus information and can be used as a reference during imaging.
[0046]
Note that the “wobbling” operation is performed only once after the operating state detecting means 66 detects the non-operating state of the focus ring 14 in order to reduce power consumption for driving the focus lens 26. Alternatively, it may be performed only once after the control means 46 detects the fluctuation of the evaluation value.
[0047]
Further, when the AF evaluation value is obtained lower than the expected value due to the hand shake of the user, the movement of the subject, etc., many AF evaluation values are obtained by performing the “wobbling” two to three times, etc. Processing that omits the AF evaluation value may be performed, or the best AF evaluation value may be selected. Further, the influence of a low AF evaluation value may be reduced by performing an averaging process. By calculating the AF evaluation value in this way, it is possible to avoid displaying the erroneous focus information display 70 due to camera shake or the like.
[0048]
Further, as shown in FIG. 5, as the depth of field changes depending on the aperture amount of the aperture 28, the control unit 46 may change the range “Z” in which the focus display 74 is performed. This makes it easier to adjust the focus when the stop 28 is stopped.
[0049]
6 and 7 show flowcharts of the camera focus display processing.
[0050]
In the flowchart shown in FIG. 6, when the focus mode of the electronic camera 10 is set to the manual focus mode and the operation state detection unit 66 detects the non-operation state of the focus ring 14, the vertical synchronization signal of the imaging unit 30 is It is shown as a subroutine called every time it is output. When the vertical synchronization signal is output in the state, the processing program of the control means 46 calls step S100 “MF determination start” (hereinafter abbreviated as S100), and the next S102 “ The process proceeds to “brightness detection (AE detection)”.
[0051]
In S102, the control means 46 performs a process of reading the AE evaluation value detected by the AE detection means 40 at the focus position P [n] and temporarily storing it in the storage means such as the memory 38 in association with the focus position P [n]. In the next S104 “Acquire AF evaluation value”, the control means 46 reads the AF evaluation value calculated by the AF detection means 42 at the focus position P [n], and associates it with the focus position P [n]. Processing to temporarily store in the storage means is performed. Then, the process proceeds to the next determination of S106 “Focus moved?”. Note that the evaluation values of the previous time, the previous time, etc. are stored by changing the subscripts such as P [n−1], P [n−2]... This is used when calculating the AF evaluation value peak position).
[0052]
In S <b> 106, it is determined whether or not the operating state is the focus position moving or the non-operating state in which the focus position is not moving. If it is in the operating state, the process branches to S108 “No display?”, And if it is in the inoperative state, the process proceeds to a subroutine of S110 “Subject change determination” described later. When the subject change determination process in S110 ends, the processing program proceeds to S124 “END”, and the MF determination processing routine ends.
[0053]
In S108, it is determined whether or not the focus information display 70 during manual focus is currently displayed on the display means 18. If the focus information display 70 is not displayed, the process proceeds to a subroutine of S112 “Peak detection process” described later. If any of the in-focus information displays 70 has already been displayed, the process proceeds to S114 “Condition a & c1 (Near?)”. In S114, it is determined whether or not the following conditions a and c1 are satisfied.
[0054]
Condition a is shown below. Condition a determines whether or not the focus position (focus position) is closer to the peak position (imaging position) (Near side), and when the following expression 1 or expression 2 is satisfied: “True”. Note that the latest AF evaluation value acquired for each vertical synchronization signal is X [n], and the focus position when the AF evaluation value is acquired is P [n]. The AE evaluation value that is the brightness of the subject at that time is defined as Ev [n].
[0055]
When the following expression 1 is true, the focus lens 26 is driven to the Near side and the AF evaluation value is decreased.
[0056]
[Expression 1]
P [n]> P [n-1]> P [n-2] & X [n] <X [n-1] <X [n-2] Formula 1
The following formula 2 is true when the focus lens 26 is driven to the Far side and the AF evaluation value increases.
[0057]
[Expression 2]
P [n] <P [n-1] <P [n-2] & X [n]> X [n-1]> X [n-2] Formula 2
The condition c1 is shown below. The condition c1 is a condition for determining whether or not the focus information display 70 is displayed when the focus information display 70 is not displayed on the display unit 18, and satisfies the following expressions 3 and 4. "True" in some cases.
[0058]
[Equation 3]
X [n]> MF · LEVEL 1 Equation 3
However, MF · LEVEL 1 is a threshold value for determining the reliability of the AF evaluation value.
[0059]
[Equation 4]
| X [n] -X [n-1] | / X ≧ MF · L · CON1 × | P [n] −P [n−1] |
Where X [n] is the current evaluation value
X [n-1]: Previous evaluation value
X: The larger value of X [n] and X [n-1]
MF / L / CON1 is the threshold
As described above, if the condition a (the focus position is closer to the peak position) and the condition c1 (display the focus information display 70) are satisfied in S108, the process branches to S116 “Near display”. The control means 46 outputs a command for displaying the near display 76 on the display means 18. When the output of the command to be displayed in S116 ends, the processing program proceeds to S124. If the condition a and the condition c1 are not satisfied in S114, the process proceeds to S118 “Condition b & c1 (Far?)”.
[0060]
In S118, it is determined whether or not the following condition b and the condition c1 are satisfied.
[0061]
Condition b is shown below. Condition b determines whether or not the focus position is far from the peak position (Far side), and is “true” when the following Expression 5 or Expression 6 is satisfied.
[0062]
The following formula 5 is true when the focus lens 26 is driven to the Near side and the AF evaluation value increases.
[0063]
[Equation 5]
P [n]> P [n-1]> P [n-2] & X [n]> X [n-1]> X [n-2] Formula 5
When the following expression 6 is true, the focus lens 26 is driven to the Far side, and the AF evaluation value decreases.
[0064]
[Formula 6]
P [n] <P [n-1] <P [n-2] & X [n] <X [n-1] <X [n-2] Equation 6
As described above, when the condition b (the focus position is far from the peak position) and the condition c1 (displays the focusing information display 70) are satisfied in S118, the process branches to S120 “Far display”, and control is performed. The means 46 outputs a command to display the far display 72 on the display means 18. When the output of the command to be displayed in S120 ends, the processing program proceeds to S124. Also, if the condition b and the condition c1 are not satisfied in S118, the processing program goes to S124 without giving a display instruction through S122 “not display”.
[0065]
When the peak detection process is completed in the subroutine of S112, the processing program proceeds to the determination of S126 “There is a peak?” And determines whether or not a peak indicating the in-focus position exists in the vicinity of the acquired AF evaluation value. . If a peak exists, the process proceeds to S200 “Aperture value (Av) acquisition”. If no peak exists, the process proceeds to S128 “Condition a & c2 (Near?)”.
[0066]
In S128, it is determined whether or not the condition a and the condition c2 shown below are satisfied.
[0067]
The condition c2 is shown below. Condition c2 is a condition for determining whether or not the subject has changed and the AF evaluation value has changed greatly when the focus position is away from the peak position, and the following Expression 7 and Expression 8 are satisfied. "True" in some cases.
[0068]
[Expression 7]
X [n]> MF · LEVEL2 Equation 7
However, MF · LEVEL2 is a threshold value for judging the reliability of the AF evaluation value.
[0069]
[Equation 8]
| X [n] -X [n-1] | / X ≧ MF · L · CON2 × | P [n] −P [n−1] |
Where X [n] is the current evaluation value
X [n-1]: Previous evaluation value
X: The larger value of X [n] and X [n-1]
MF / L / CON2 is the threshold
As described above, if the condition a (the focus position is closer to the peak position) and the condition c2 (the AF evaluation value has changed greatly) are satisfied in S128, S130 “Far displayed?” Branch to the decision. If the condition a and the condition c2 are not satisfied in S128, the process proceeds to S132 “Condition b & c2 (Far?)”.
[0070]
In S132, it is determined whether or not the condition b and the condition c2 are satisfied. If the condition b (the focus position is far from the peak position) and the condition c2 (AF evaluation value has changed greatly) are satisfied in S132, the process branches to the determination of S134 "Near displayed?" . If the condition b and the condition c2 are not satisfied in S132, the process proceeds to S136 "Do not change display", and the display is left as it is, and the process proceeds to the next S124.
[0071]
In S130, it is determined whether or not the far display 72 is being displayed on the display means 18. If the far display 72 is not being displayed on the display means 18, the process branches to S124 without doing anything. If the far display 72 is being displayed on the display means 18, the process proceeds to S140 "Near display", and the control means 46 outputs a command to display the near display 76 on the display means 18. When the output of the command to be displayed in S140 ends, the processing program proceeds to S124.
[0072]
In S134, it is determined whether or not the near display 76 is being displayed on the display means 18. If the near display 76 is not being displayed on the display means 18, the process branches to S124 without doing anything. Further, if the near display 76 is being displayed on the display means 18, the process proceeds to S138 "Far display", and the control means 46 outputs a command to display the far display 72 on the display means 18. When the output of the command to be displayed in S138 is completed, the processing program proceeds to S124.
[0073]
Next, the processing program shown in FIG. 7 will be described.
[0074]
In S200, the control means 46 acquires the aperture value of the aperture 28 and sets the depth of field of the subject. Then, an N [Av] value indicating the range of the allowable circle of confusion corresponding to this depth of field is calculated, and the process proceeds to the next determination of S202 “| P [n] −Peak | <N [Av] Pulse?”. . In S202, the distance of the focus position calculated based on the permissible circle of confusion (when a stepping motor is used for the motor 54 that drives the focus lens 26, or the movement amount of the focus lens 26 is managed by the number of pulses. The distance information in the permissible circle of confusion is equal to the number of pulses) between N [Av] and the latest focus position P [n] and the focus position “Peak” at which the AF evaluation value peaks. The distance is compared.
[0075]
If the determination in S202 is “false” (when the current focus position is outside the depth of field with respect to the peak position), the processing program proceeds to the determination in S204 “Condition a & c2 (Near?)”. Also, if the determination in S202 is “true” (when the current focus position is within the depth of field with respect to the peak position), the processing program proceeds to the determination in S208 “condition a & c3 (Near?)”. .
[0076]
In S208, it is determined whether or not the condition a and the condition c3 shown below are satisfied.
[0077]
The condition c3 is shown below. Condition c3 is a condition for determining whether or not the subject has changed and the AF evaluation value has changed greatly when the current focus position is in the vicinity of the peak position. When the following expressions 9 and 10 are satisfied To "true".
[0078]
[Equation 9]
X [n]> MF · LEVEL3 Equation 9
However, MF · LEVEL 3 is a threshold value for judging the reliability of the AF evaluation value.
[0079]
[Equation 10]
| X [n] -X [n-1] | / X ≧ MF · L · CON3 × | P [n] −P [n−1] |
However, MF, L, and CON3 are threshold values.
As described above, if the condition a (the focus position is closer to the peak position) and the condition c3 (the AF evaluation value has changed greatly) are satisfied in S208, the process branches to S210 “Near display”. If the condition a and the condition c3 are not satisfied in S208, the process proceeds to S212 “Condition b & c3 (Far?)”.
[0080]
In S212, it is determined whether or not the condition b and the condition c3 are satisfied. If the condition b (the focus position is far from the peak position) and the condition c3 (AF evaluation value has changed greatly) are satisfied in S212, the process branches to S214 "Far display". If the condition b and the condition c3 are not satisfied in S212, the process proceeds to S216 “In-focus display”, and the control unit 46 outputs a command to display the in-focus display 74 on the display unit 18. When the output of the command to be displayed in S216 ends, the processing program proceeds to S124 shown in FIG.
[0081]
In S210, the control means 46 outputs a command to display the near display 76 on the display means 18. When the output of the command to be displayed in S210 is completed, the processing program proceeds to the next S220 “Peak position reset”, and when it is determined that the subject has changed near the peak position, the stored AF evaluation value and A process of resetting the focus peak position is performed, and the process proceeds to S124 shown in FIG.
[0082]
In S214, the control means 46 outputs a command to display the far display 72 on the display means 18. When the output of the command to be displayed in S214 is completed, the processing program proceeds to the next S218 “Peak position reset”, and in response to determining that the subject has changed near the peak position, the stored AF evaluation value and A process of resetting the focus peak position is performed, and the process proceeds to S124 shown in FIG.
[0083]
In S204, it is determined whether or not the condition a and the condition c2 are satisfied. If the condition a (the focus position is closer to the peak position) and the condition c2 (AF evaluation value has changed significantly) are satisfied in S204, the process branches to the determination in S222 “Far Displaying?” . If the condition a and the condition c2 are not satisfied in S204, the process proceeds to S224 “Condition b & c2 (Far?)”.
[0084]
In S224, it is determined whether or not the condition b and the condition c2 are satisfied. If the condition b (the focus position is far from the peak position) and the condition c2 (AF evaluation value has changed greatly) are satisfied in S224, the process branches to S226 “Near Displaying?”. If the condition b and the condition c2 are not satisfied in S224, the state is maintained as it is and the process proceeds to S124.
[0085]
In S222, it is determined whether or not the far display 72 is being displayed on the display means 18. If the far display 72 is not being displayed on the display means 18, the process branches to S234 "Near display" without doing anything. If the far display 72 is being displayed on the display means 18, the process proceeds to S232 "Peak position reset", and the stored AF evaluation value and the focus peak position are received in response to the change of the subject. A reset process is performed, and the process proceeds to S234.
[0086]
In S234, the control means 46 outputs a command to display the near display 76 on the display means 18. When the output of the command to be displayed in S234 ends, the processing program proceeds to S124.
[0087]
In S234, it is determined whether or not the near display 76 is being displayed on the display means 18. If the near display 76 is not being displayed on the display means 18, the process branches to S230 "Far display" without doing anything. If the near display 76 is being displayed on the display means 18, the process proceeds to S232 "Peak position reset", and the stored AF evaluation value and focus peak position are reset in response to the change of the subject. The process proceeds to S230.
[0088]
In S230, the control means 46 outputs a command to display the far display 72 on the display means 18. When the output of the command to be displayed in S230 ends, the processing program proceeds to S124.
[0089]
The focus information display 70 is displayed when the AF evaluation value peak is within the allowable circle of confusion. Since the permissible circle of confusion changes depending on the aperture, the focus position range for focusing display is changed depending on the aperture value.
[0090]
FIG. 8 is a flowchart showing processing of the subject change determination subroutine shown in S110 of FIG.
[0091]
When the processing program reaches S110 shown in FIG. 6, the subroutine of S300 “Subject change determination” shown in FIG. 8 is called, and the process proceeds to the next determination of S302 “condition d”.
[0092]
In the determination in S302, AF evaluation is performed to determine whether or not the subject has changed when the focus mode of the electronic camera 10 is set to the manual focus mode and the operation state detection unit 66 detects the non-operation state of the focus ring 14. This is an example of processing based on the value, and it is assumed that the condition d is “true” when both of the following Expression 11 and Expression 12 are satisfied.
[0093]
Expression 11 shown below is obtained when the maximum value MAX and the minimum value MIN of the AF evaluation values acquired after the operating state detecting unit 66 detects the non-operating state of the focus ring 14 satisfy the following conditions: Judge that the subject may have changed.
[0094]
[Expression 11]
(MAX−MIN) / MAX ≧ MF · CHG Formula 11
However, MF / CHG indicates a threshold value.
The calculation of Expression 12 shown below is performed in order to evaluate the reliability of the detection value when detecting that the subject has changed.
[0095]
[Expression 12]
MAX> MF · CHG · LVL Equation 12
However, MF, CHG, and LVL indicate threshold values.
If the condition d is “false” in S302 described above, the processing program proceeds to the determination in S304 “condition e”.
[0096]
In the determination of S304, whether or not the subject has changed when the focus mode of the electronic camera 10 is set to the manual focus mode and the operating state detecting unit 66 detects the non-operating state of the focus ring 14 is determined by AE evaluation. This is an example of processing based on the value, and the condition e is “true” when the operating state detecting means 66 continues to detect the non-operating state of the focus ring 14 and the following expression 13 is satisfied. It is said that.
[0097]
Since the following equation 13 is a possibility that the subject has changed due to a change in the AE evaluation value acquired after the operating state detecting means 66 detects the non-operating state of the focus ring 14, the focus information display 70 Judging that it is necessary to change.
[0098]
[Formula 13]
| Ev [n] -Ev [n-1] |> MF, EV, DIF
Where Ev [n]: current subject brightness
Ev [n-1]: Brightness of the previous subject
MF / EV / DIF indicates threshold
If the condition e is “true” in the above S304, or if the condition d is “true” in the above S302, the processing program proceeds to S306 “peak position reset / peak value reset” and the subject is detected. In response to the determination of the change, the stored AF evaluation value, AE evaluation value, and focus peak position are reset, and the process proceeds to S308 “display OFF”. In S <b> 308, the control unit 46 outputs a command for deleting the focus information display 70 to the display unit 18. The instruction to delete the focus information display 70 here may be a command to display the focus position determination impossible display 78 shown in FIG. When the display command is output in S308, the processing program proceeds to S310 “END”, and the subject change determination processing routine is terminated. Also, when the condition e is “false” in S304, the processing program proceeds to S310.
[0099]
FIG. 9 is a flowchart showing the subroutine of the “peak detection process” shown in S112 of FIG.
[0100]
When the processing program reaches S112, the subroutine of S400 “Focus Peak Determination” shown in FIG. 9 is called, and the process proceeds to the next determination of S402 “Condition f”.
[0101]
In the determination of S402, 5 obtained immediately before the operating state detecting means 66 detects the non-operating state of the focus ring 14 or after detecting the non-operating state of the focus ring 14 when performing the operation of “wobbling”. It is determined whether or not the type of focus position where the evaluation value exists is near the peak position of the AF evaluation value of the subject.
[0102]
The condition f is assumed to be “true” when the following expression 14 or 15 and expression 16 are satisfied.
[0103]
Expression 14 below shows a state in which the focus lens 26 is continuously moved to the Near side.
[0104]
[Expression 14]
P [n]> P [n-1]> P [n-2]> P [n-3]> P [n-4]
Expression 15 below shows a state in which the focus lens 26 is continuously moved to the Far side.
[0105]
[Expression 15]
P [n] <P [n-1] <P [n-2] <P [n-3] <P [n-4]
When the following Expression 16 is satisfied, it indicates that the AF evaluation value has the shape shown in FIG.
[0106]
FIG. 10 is a diagram showing the AF evaluation values at the respective focus positions measured at five locations by automatic or manual drive of the focus position. In the figure, the embodiment in which five points are measured is described, but the object of the present invention can be achieved even if the focus peak is determined based on the AF evaluation values at three or more focus positions. Is done.
[0107]
[Expression 16]
X [n] <X [n-1] <X [n-2] &
& X [n-2]> X [n-3]> X [n-4] Formula 16
If it is determined in step S402 that the condition f is "true" as a result of the focus determination based on the five consecutive output changes, the processing program stores the peak in S404 "Peak position (Peak) storage". Proceeding to "ON flag", in response to detecting the peak position of the AF evaluation value, the AF evaluation value of the peak position, the AE evaluation value, and the peak position of the focus are stored in the storage means, and the peak present flag is stored. Then, the process proceeds to the next S406 “focus display”, and the control means 46 outputs a command to display the focus display 74 on the display means 18. When the display instruction is output in S406, the processing program proceeds to S408 “END”, and the processing routine for determining the in-focus peak is completed. Also, in the case where the condition f is “false” in S402, the processing program proceeds to S408.
[0108]
Further, the reliability determination shown in the following Expression 17 may be added to the above condition f.
[0109]
When the following Expression 17 is satisfied, it indicates that the reliability of having a peak from the peak shape of the AF evaluation value is high.
[0110]
[Expression 17]
(X [n-2] -X [n]) / X [n-2]>
> MF · LCON2 × | P [n-2] -P [n] |
&
(X [n-2] -X [n-4]) / X [n-2]>
> MF · LCON2 × | P [n−2] −P [n−4] |
However, MF / LCON2 indicates a threshold value.
[0111]
【The invention's effect】
As described above, according to the focus information display device and method of the camera according to the present invention, the subject image is formed in the focus information display device of the camera that drives the focus lens based on the operation of the focus operation member. Imaging means for outputting an imaging signal, focusing information detection means for detecting focusing information based on the imaging signal output by the imaging means, and focusing information based on the detection output of the focusing information detection means Display means for displaying, and when the focus operation member is not operated and the focus information is displayed on the display means, the display means changes the detection output of the focus information detection means. Since the control means for changing the display of the focus information displayed on the screen is provided, it is easy to manually confirm and adjust the imaging position.
[0112]
According to another aspect of the invention, in a focusing information display device for a camera that drives a focus lens based on an operation of a focus operation member, an imaging unit that forms an image of a subject and outputs an imaging signal; Focus information detection means for detecting focus information based on the imaging signal output by the imaging means, display means for displaying focus information based on the detection output of the focus information detection means, and output by the imaging means Brightness information detection means for detecting brightness information of a subject based on the captured image signal, and the brightness information detection when the focus operation member is not operated and the focus information is displayed on the display means. When the detection output of the means changes, the control means for changing the display of the focusing information displayed on the display means is provided, so that it is easy to manually confirm and adjust the imaging position.
[0113]
Further, according to the present invention, in order to reduce the power consumption of the camera, the wobbling operation for knowing the in-focus direction is not performed or is performed in a limited manner. When the focus lens is not moving, it is impossible to know the in-focus direction for the latest subject. Therefore, when the focus lens is not moving and it is considered that the subject has changed, the display content of the display means is changed so that the wrong focus direction is not displayed. This makes it easy to confirm the imaging position.
[0114]
Further, according to another aspect of the invention, since the in-focus information stored in association with three or more lens positions is used, a more accurate in-focus direction and in-focus state can be detected, and manual imaging is performed. The position can be easily confirmed and adjusted.
[Brief description of the drawings]
FIG. 1 is a front perspective view of an electronic camera according to the present invention.
FIG. 2 is a rear perspective view of the electronic camera according to the present invention.
FIG. 3 is a block diagram of a signal processing system of an electronic camera.
FIG. 4 is a diagram showing a display example of a focus display displayed on the display unit of the electronic camera.
FIG. 5 is a diagram illustrating a relationship between a focus position in a certain subject image and an acquired AF evaluation value.
FIG. 6 is a flowchart showing a focusing information display method of the camera.
FIG. 7 is a flowchart showing a focusing information display method of the camera.
FIG. 8 is a flowchart showing processing of a subject change determination subroutine;
FIG. 9 is a flowchart showing processing of a subroutine for focused peak determination processing;
FIG. 10 is a diagram showing each AF evaluation value at each focus position automatically measured five times.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Electronic camera, 12 ... Lens, 14 ... Focus ring, 18 ... Display means, 22 ... AF / MF changeover switch, 26 ... Focus lens, 28 ... Aperture, 30 ... Imaging means, 32 ... Imaging circuit, 34 ... A / D converter 36 ... bus 38 ... memory 40 ... AE detecting means 42 ... AF detecting means 46 ... control means 48 ... motor 50 ... zoom driving means 52 ... zoom position detecting means 54 ... motor, 56 ... Focus drive means, 58 ... HP sensor, 60 ... Motor, 62 ... Aperture control means, 64 ... HP sensor, 66 ... Operating state detection means, 70 ... Focus information display, 72 ... Far display, 74 ... Focus display , 76 ... Near display, 78, 80 ... In-focus position determination impossible display

Claims (10)

In the focus information display device of the camera that drives the focus lens based on the operation of the focus operation member,
Imaging means for forming a subject image and outputting an imaging signal;
Position grasping means for grasping the lens position of the focus lens;
Based on the imaging signal of the imaging means it has outputted at each lens position of three or more detected by said position detection means, and focusing information detection means for detecting focusing information of each lens position,
Storage means for storing the focusing information which the automatic focus detecting means detects,
Based on the focus information corresponding to said stored three or more lenses located in the storage means, to determine the direction in which the focus information is increased or decreased, the lens position where the object image is focused on said image pickup means A lens position calculating means for obtaining focusing information indicating a relationship between the in-focus position and the current focus lens position ;
Display for displaying the focus state on the basis of the focus information corresponding to the determined lens position and the lens position of the current focus lens, the focus information detecting means lens position of the three or more places has been detected and means,
The focus information detecting means detects focus information at each lens position based on a result of detecting the focus information a plurality of times at each of the three or more lens positions, and the imaging signal of the imaging signal by the imaging means is detected. Focus information display of a camera, wherein focus information obtained from an imaging signal blurred by relative movement between the subject and the camera at the time of acquisition is omitted, and focus information at each lens position is detected apparatus. In the focus information display device of the camera that drives the focus lens based on the operation of the focus operation member,
Imaging means for forming a subject image and outputting an imaging signal;
Position grasping means for grasping the lens position of the focus lens;
Focusing information detection means for detecting focusing information at each lens position based on imaging signals output by the imaging means at each of three or more lens positions detected by the position grasping means;
Storage means for storing the focus information detected by the focus information detection means;
Based on focusing information corresponding to the three or more lens positions stored in the storage unit, a direction in which the focusing information increases or decreases is determined, and a lens position at which the subject image is focused on the imaging unit A lens position calculating means for obtaining focusing information indicating a relationship between the in-focus position and the current focus lens position;
Display that displays the in-focus state based on the obtained lens position and the lens position of the current focus lens, and in-focus information corresponding to the three or more lens positions detected by the in-focus information detecting unit Means and
The focus information detection means detects focus information at each lens position based on a result of detecting focus information a plurality of times at each of the three or more lens positions , and obtains the imaging signal by the imaging means. the effect of the imaging signal blurred by the relative movement between at the subject and the camera, averaging the less to focus information display features and to Luke camera to detect the focusing information in each lens position apparatus.   The lens position calculating means determines whether or not there is a peak satisfying a predetermined criterion from the change state of the focusing information at three or more locations stored in the storage means, and only when the peak exists. 3. A focusing information display device for a camera according to claim 1, wherein a lens position for focusing is obtained. The focusing information detection means determines whether the current focus lens position is within an allowable circle of confusion,
The display means displays focus information indicating that the in-focus state is detected when the focus information detection means determines that the lens position of the current focus lens is within an allowable circle of confusion. The in-focus information display device for a camera according to any one of claims 1 to 3. A diaphragm for limiting the amount of light incident on the imaging means;
Detecting means for detecting a diaphragm amount of the diaphragm;
The focus information detecting means determines whether the lens position and the current focus lens is within the permissible circle of confusion on the basis of the current throttle amount detected by said detection means,
When the focus information detecting means determines that the lens position of the current focus lens is within an allowable circle of confusion, the display means displays focus information indicating that the focus is in focus. The focusing information display device for a camera according to any one of claims 1 to 3. In the focus information display method of the camera that drives the focus lens based on the operation of the focus operation member,
An imaging step of forming a subject image by an imaging means and outputting an imaging signal;
Based on the imaging signal of the imaging means it has outputted at each lens position of three or more detected by the position monitor which monitors the lens position of the focus lens, the focusing information detecting means focusing information at each lens position A focus information detection step to detect,
A storage step of storing the focus information detected in the focus information detection step in a storage means;
Based on focusing information corresponding to the three or more lens positions stored in the storage unit, a direction in which the focusing information increases or decreases is determined, and a lens position at which the subject image is focused on the imaging unit A lens position calculating step for obtaining focusing information indicating the relationship between the in-focus position and the current focus lens position ;
A lens position of the determined lens position and the current focus lens, the focus information detecting step display means the focusing state based on the focus information corresponding to said detected three or more lens positions in and a display step of displaying on,
In the focus information detection step, focus information at each lens position is detected based on a result of detecting the focus information a plurality of times at each of the three or more lens positions, and when the imaging signal is acquired, A focusing information display method for a camera, characterized in that focusing information obtained from an imaging signal blurred by relative movement between a subject and the camera is omitted and focusing information at each lens position is detected . In the focus information display method of the camera that drives the focus lens based on the operation of the focus operation member,
An imaging step of forming a subject image by an imaging means and outputting an imaging signal;
Focus information at each lens position is detected by the focus information detection means based on the imaging signals output by the imaging means at each of the three or more lens positions detected by the position grasping means for grasping the lens position of the focus lens. An in-focus information detection step,
A storage step of storing the focus information detected in the focus information detection step in a storage means;
Based on focusing information corresponding to the three or more lens positions stored in the storage unit, a direction in which the focusing information increases or decreases is determined, and a lens position at which the subject image is focused on the imaging unit A lens position calculating step for obtaining focusing information indicating the relationship between the in-focus position and the current focus lens position;
Display means for displaying the in-focus state based on the obtained lens position, the lens position of the current focus lens, and the in-focus information corresponding to the three or more lens positions detected in the in-focus information detecting step. And a display process for displaying on
Wherein in the focus information detecting step, wherein the focus information in each of three or more lens positions based on the plurality of times detected result detected focusing information at each lens position acquired at the subject of the imaging signal the relative influence of imaging signals blur by moving average less to features and to Luke camera focus information display method of detecting the focusing information in each lens position by processing between the camera and.   In the lens position calculating step, it is determined whether or not there is a peak satisfying a predetermined criterion from the change state of the focusing information at three or more locations stored in the storage means, and the alignment is performed only when the peak exists. 8. The focusing information display method for a camera according to claim 6, wherein a lens position to be focused is obtained. Determining whether the lens position of the current focus lens is within a permissible circle of confusion;
Displaying on the display means in-focus information indicating that focusing is performed when it is determined that the lens position of the current focus lens is within an allowable circle of confusion;
The in-focus information display method for a camera according to claim 6, further comprising: Whether the lens position of the current aperture value the current focus lens based on detected by the detecting means for detecting the aperture amount of the diaphragm for limiting the amount of light incident on the imaging unit is within the permissible circle of confusion A process of judging;
When the focus information detection means determines that the current focus lens position is within the allowable circle of confusion, the focus information indicating that the focus is in focus is displayed on the display means;
The in-focus information display method for a camera according to claim 6, further comprising:

Images