JP2002072332A - Focusing information display device and method thereof for camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a focusing information display device and a method thereof for a camera by which an image forming position by manual focusing is easily confirmed and adjusted. SOLUTION: This camera is equipped with an image pickup means 30 forming a subject image and outputting an image pickup signal, an AF detection means 42 detecting focusing information based on the image pickup signal, a display means 18 displaying the detected focusing information, and a control means 46 changing the display of the focusing information when detection output from the detection means 42 is changed in the case the focusing information is displayed in a state where a focusing operation member is not operated. Therefore, the image forming position by manual operation is easily confirmed and adjusted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for displaying focus information of a camera, and more particularly to a camera capable of displaying a focus direction or a focus state when manual focus is set and notifying a user of the focus information. The present invention relates to a focusing information display device and a method thereof.

[0002]

2. Description of the Related Art Conventionally, in an electronic camera or a video camera, a manual focus (MF) ring is turned so that a user can manually focus on a desired position. Some are known to be movable. The user focuses while checking the image obtained by the image sensor with an EVF (electronic viewfinder) or LCD (liquid crystal display) monitor, but focuses by judging the blur of the monitor image with the naked eye. Even if it is attempted to do so, it is not known whether the original in-focus position exists on the near side or the in-focus position exists in the far side. That was 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 a movie image is in focus or not.

For this purpose, focusing information is detected based on a video signal obtained by imaging a subject, a pattern signal indicating the focusing information is generated based on the detected information, and focusing is performed based on the pattern signal. Camera-integrated V that displays a pattern indicating focus information during manual focus control
TR is disclosed in Japanese Patent Application Laid-Open No. 5-308552.

[0004] Further, by displaying the direction in which the focus lens should be moved using a gradation ratio corresponding to the position of the focus lens, the time spent by the user to focus the focus lens on the subject can be reduced. A possible lens focus state display device and a lens focus adjustment device having the same are disclosed in JP-A-6-319073.

[0005]

However, in the conventional camera, it is necessary to always move (wobble) the focus lens in order to adjust the focus state and to know the focus direction. There has been a problem that the power must be kept running and the power consumption increases.

In addition, since the data before moving the focus lens and the data after moving the focus lens are displayed to indicate the focusing direction, when the output of the focusing information detecting means changes due to camera shake or a change in the subject. However, there is a problem that an incorrect focusing direction is displayed.

The present invention has been made in view of such circumstances, and displays focus information automatically displayed in the manual focus mode by reducing display of erroneous focus information due to a change in a subject or camera shake. By performing the fine control, it is possible to provide a camera focusing information display device and a method thereof, in which confirmation and adjustment of an image forming position by manual focus are easy.

[0008]

According to a first aspect of the present invention, there is provided a focus information display device for a camera which drives a focus lens based on an operation of a focus operation member. An imaging unit that forms an image and outputs an imaging signal; a focusing information detection unit that detects focusing information based on the imaging signal output by the imaging unit; and an imaging unit that focuses on the detection output of the focusing information detection unit. Display means for displaying focus information, when the focus operation member is not operated, and when the detection output of the focus information detection means changes when focus information is displayed on the display means,
Control means for changing the display of the focus information displayed on the display means.

According to a second aspect of the present invention, in a focusing information display device for a camera which drives a focus lens based on an operation of a focus operation member, an imaging means for forming an object image and outputting an imaging signal. Focusing information detecting means for detecting focusing information based on an imaging signal output by the imaging means; display means for displaying focusing information based on a detection output of the focusing information detecting means; A brightness information detecting means for detecting brightness information of a subject based on an imaging signal output by the means; and a focus information member when the focus operation member is not operated and focus information is displayed on the display means. Control means for changing the display of the focus information displayed on the display means when the detection output of the luminance information detection means changes.

That is, according to the present invention, in order to reduce the power consumption, the wobbling operation for knowing the focusing direction is not performed, or the wobbling operation is performed in a limited manner. When the focus lens is not moving), it is impossible to know the latest focusing direction for the subject or the like. Therefore, when the focus lens is not moving, it is considered that the subject has changed (that is, when the detection output of the focus information detecting means changes without moving the focus lens (Claim 1), or when the brightness information is changed. When the detection output of the detection means changes (claim 2), the display content of the display means is changed so that an erroneous focusing direction or the like is not displayed. Specifically, the display of the focus information displayed on the display means is deleted as described in claim 3.

[0011] In order to achieve the above object, the present invention provides a fourth aspect.
According to the invention described in (1), in a focus information display device of 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 lens position of the focus lens Position grasping means for grasping, focus information detecting means detecting focus information based on the output image signal in association with three or more lens positions detected by the position grasping means, and focus information detecting means Storage means for storing the focus information detected by the camera, means for obtaining 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 focus lens. And a display means for displaying focus information based on the detection position detected by the focus information detection means.

According to the present invention, since the focus information stored in association with three or more lens positions is used, a more accurate focus direction and focus state can be detected, and the image formation position can be manually determined. Confirmation and adjustment are easy.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a camera focusing information display apparatus and method according to the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a front perspective view of an electronic camera according to the present invention.

Referring to FIG. 1, an electronic camera 10 has a variable-magnification lens 12 for picking up an image of a subject, and is rotatably provided on the outer periphery of the lens 12. A focus ring 14 (focus operation member) that allows the user to manually adjust the position to be performed, and a release button 16 that instructs imaging when the user captures an image of a subject are provided.

FIG. 2 is a rear perspective view of the electronic camera 10.

As shown in FIG. 1, the electronic camera 10 includes a display means 18 for displaying an image to be captured and information on the focus position of the image, a zoom lever 20 for adjusting the angle of view of the captured image to TELE / WIDE. , An AF / MF switch 22.

The AF / MF switch 22 is used to control an adjustment mode of an image formation position at which a subject image is formed on the image pickup means of the electronic camera 10, an auto focus mode for automatically adjusting the image formation position, or a user's own desired image formation position. This is a switch for setting a manual focus mode for adjusting the focus.

The user operates the zoom lever 20 while confirming the through image being photographed displayed on the display means 18 and determines the angle of view in the direction of WIDE, TELE or the like, and photographs. Also, when the user sets the AF / MF switch 22
By pressing, it is possible to switch between the auto focus mode and the manual focus mode. At the time of setting the manual focus mode, the user turns the focus ring 14 to focus on a desired subject while viewing the through image displayed on the display unit 18. In the present invention, in the manual focus mode, by correctly displaying focus information as shown in FIG. 4 described later, it is possible for the user to adjust the focus more accurately and easily.

FIG. 3 is a block diagram of a signal processing system of the electronic camera.

According to FIG. 1, the lens 1 of the electronic camera 10
2 is provided with a variable power lens 24, a focus lens 26, and an aperture 28, and behind it, an imaging unit 30 composed of a solid-state imaging device and the like, and a timing pulse for controlling the imaging unit 30 are generated. And an image sensor driving circuit 31 to be used. The image signal output from the image pickup means 30 is supplied to an image pickup circuit 32 (sample hold and
A / D converter 34 converts the data into digital data, and the bus 36 (including a data bus and an address bus).
Is output to

The bus 36 has a memory 38 as storage means capable of storing one or a plurality of focus information and luminance information, and an AE detection means 4 for detecting the brightness of a captured image.
0 (luminance information detecting means), an AF detecting means 42 (focusing information detecting means) for calculating an AF evaluation value as focusing information by detecting a luminance component of the captured image, and Display means 1 for displaying information about the focal position
8, a recording medium 44 such as an external storage device for recording information such as images, and control means 4 for controlling the entire electronic camera 10.
6 (CPU).

The electronic camera 10 also includes a motor 48 for driving the variable power lens 24 of the lens 12, zoom driving means 50 for driving the motor 48, and a variable power lens 24.
Zoom position detecting means 52 for detecting the zoom position of the zoom lens, a motor 54 for driving the focus lens 26, and a motor 54
A focus driving means 56 for driving the lens, an HP sensor 58 for detecting a focus origin position of the focus lens 26, a motor 60 for adjusting the opening degree of the diaphragm 28,
An aperture control means 62 for driving the motor 60 and an HP sensor 64 for detecting the origin position of the aperture 28 are provided.

An operation signal of the zoom lever 20 and an operation signal of the AF / MF switch 22 are input to the control means 46 of the electronic camera 10 so that these operation states can be recognized. Has become. The operation signal of the focus ring 14 is input to the operation state detecting means 66, and the user manually rotates the focus ring 14 to drive the image forming position (at the time of operation) and turns the focus ring 14. A non-operating state (non-operating state), which is a state in which it is not moved, is determined and input to the control means 46. Further, the operating state detecting means 66 detects that the focus ring 1
Instead of judging the operation state and the non-operation state of the focus ring 4, the operation state of the focus ring 14 is input to the control means 46, and the control means 46 performs a process of judging the operation state and the non-operation state of the focus ring 14. It may be.

The control means 46 (including the function of the aperture amount detecting means) controls the drive of the variable power lens 24 and the detection of the variable power, the drive control of the focus lens 26 and the detection of the focus position (the function of the position grasping means). ), Drive control of the diaphragm 28, detection of the diaphragm amount, and the like.

Hereinafter, a method for manually adjusting the imaging position using the electronic camera 10 according to the present invention will be described.

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 focusing mode. The operating state detecting means 66 constantly monitors the operating state of the focus ring 14 and detects whether or not the focus ring 14 is operated. The speed, the rotation amount, and the like are detected, and the information is output to the control means 46.

The control means 46 which 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. The imaging position is adjusted by driving to a predetermined speed or position. In the above description, the focus ring 1
4 has been described in the embodiment in which the operation state detecting means 66 detects the rotation of the focus lens 4 and controls the focus lens 26 based on the detected operation state. However, the present invention is not limited to this. The object of the present invention is achieved even by a focus lens driving method including a mechanism in which the amount of rotation of the focus ring 14 is directly transmitted to the focus lens 26 at the time of setting.

The control means 46 controls the image pickup means 30 via the image pickup element drive circuit 31, A / D converts the output from the image pickup means 30 into the memory 38, and displays the moving image on the display means 18. Perform the following processing. 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 contrast of each area or a predetermined area is averaged by performing an averaging process or the like.
Output as F evaluation value.

The AE detecting means 40 reads out 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 brightness level of the subject is obtained by integrating each area or a predetermined area, and the obtained brightness level is output to the control means 46 as an AE evaluation value. The control means 46 calculates an aperture value and an exposure force such as a shutter speed necessary for imaging based on the AE evaluation value,
An exposure power setting command is output to each peripheral device.

FIG. 4 shows a display example of the focus display displayed on the display means.

As shown in the figure, the display means 18 displays a focus information display 70 for notifying the user of the focus state, a "P" display indicating that the exposure mode for shooting is the program mode, A shutter speed display “500”, an aperture value display “F2.8”, and the like are displayed.

As the focus information display 70, a far display 72 for notifying the user that the current image forming position of the focus lens 26 is farther than the subject image, and a current image forming position of the focus lens 26 are displayed. Focus indication 74 for notifying the user that the subject is within the range including the depth of field.
And a near display 76 for notifying the user that the current imaging position of the focus lens 26 is closer to the subject image than the subject image, and the subject image is affected by the color, brightness, shape, pattern, etc. of the subject. The in-focus position determination displays 78 and 80 for notifying the user that the in-focus position cannot be calculated correctly are shown.

Each of these displays can be superimposed on a captured image by writing the image shown in FIG. 4 into a memory provided in the display means 18. OSD (On Screen not shown)
(Display) circuit, and superimposing displays can be realized by synthesizing analog signals.

FIG. 5 shows the relationship between the focus position of a certain subject and the obtained AF evaluation value.

In the example shown in the figure, since the AF evaluation value shows a large value in the range of the focus position "Z", it can be estimated that the main subject exists in the range of "Z". It is assumed 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 operation state detecting means 66 detects the non-operation state of the focus ring 14 and outputs the non-operation information to the control means 46.

At this time, the control means 4 determines that the AF evaluation value has a tendency to decrease with respect to the focus position within a minute range of “ΔL” immediately before stopping at the focus position “L”.
When the control unit 6 determines, the control unit 46 determines that the image forming position is farther than the in-focus position, and displays a far display 72 on the display unit 18 to notify the user of the fact. The user
The focus direction can be determined based on the displayed focus information, and can be used as a reference when imaging.

A case where the user rotates the focus ring 14 and stops the focus ring 14 at, for example, the focus position "M" will be described. At this time, in the minute range of “ΔM” immediately before stopping at the focus position “M”, the rate of increase of the AF evaluation value with respect to the focus position is monitored, and if the control unit 46 determines that the AF evaluation value is near the peak position, The means 46 determines that the in-focus position is near "M", displays the in-focus indication 74 on the display means 18, and notifies the user of this.

A case where the user rotates the focus ring 14 and stops the focus ring 14 at, for example, the focus position "N" will be described. At this time, when the control unit 46 determines that the AF evaluation value has tended to increase with respect to the focus position within the minute range of “ΔN” immediately before stopping at the focus position “N”, the control unit 46 sets the focus position to the in-focus position. It is determined that it is closer to the position than it is, and the near display 76 is displayed on the display means 18 to notify the user of the fact. The user can determine the focusing direction based on the displayed focusing information, and can refer to it when taking an image.

The once displayed focus information display 70 is erased based on a change in the AF evaluation value output from the AF detection means 42 or a change in the AE evaluation value output from the AE detection means 40. In general, when the AF evaluation value fluctuates or the AE evaluation value fluctuates, it is highly likely that the subject has moved relatively to the electronic camera 10 and that the subject has changed. 70 may be deleted.

As described above, instead of erasing the once displayed focus information display 70 based on the change in the AF evaluation value output from the AF detection means 42 or the change in the AE evaluation value output from the AE detection means 40, In addition, the “wobbling” operation described below is performed one or more times to acquire focusing information,
A new focus direction or focus state may be displayed to change the focus information displayed on the display unit 18.

For example, when the focusing information display 70 and the like are displayed on the display means 18 in the manual focus mode, the control means 46 outputs the AF signal output from the AF detection means 42.
Variation of the evaluation value or AE output by the AE detection means 40
It is assumed that a change in the evaluation value is detected. The control means 46 having detected the fluctuation of the evaluation value instructs the focus driving means 56 to perform the “wobbling” operation of driving the minute range focus lens 26 one or more times in accordance with the condition of whether or not the “wobbling” operation can be performed. I do. When performing this “wobbling” operation, the adjustment mode of the imaging position 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 focusing direction. A process of automatically performing the “wobbling” operation of the focus lens 26 one or more times and searching for the focusing direction with reference to the AF evaluation value is performed. In this case, the control unit 46 functions as an image forming position driving unit that automatically drives the image forming position.

For example, when the operation of "wobbling" is performed at the focus position "L", the operation of "wobbling" is performed within a range of, for example, "ΔL". If the detected AF evaluation value has a decreasing tendency with respect to the focus position, the control means 46 determines that the image forming position is farther than the in-focus position, and displays a far display 72 on the display means 18; Notify the user to that effect. The user can determine the focusing direction based on the displayed focusing information, and can refer to it when taking an image. If the user wants to change the imaging position, the user rotates the focus ring 14 to adjust the imaging position to a desired position. At this time, the amount of rotation of the focus ring 14 is detected by the operating state detecting means 66, and based on the detected operating state, the control means 46
To control the focus position.

When the operation of "wobbling" is performed at the focus position "M", the operation of "wobbling" is performed, for example, within the range of "ΔM". If it is determined that the detected AF evaluation value is near the peak position related to the focus position, the control unit 46 determines that the in-focus position is near “M” and displays the display unit 18.
Is displayed, and the user is notified of that.

When the operation of "wobbling" is performed at the focus position "N", the operation of "wobbling" is performed, for example, within the range of "ΔN". If the detected AF evaluation value is increasing with respect to the focus position, the control unit 46 determines that the focus position exists closer to the electronic camera 10 and
Is displayed, and the user is notified of this. The user can determine the focusing direction based on the displayed focusing information, and can refer to it when taking an image.

When the "wobbling" operation is performed, in order to reduce the power consumption for driving the focus lens 26, the operation state detecting means 66 detects the non-operation state of the focus ring 14 after the detection. It may be performed only once, or may be performed only once after the control means 46 detects the fluctuation of the evaluation value.

When the AF evaluation value is lower than the expected value due to camera shake of the user, movement of the subject, or the like,
A process of obtaining a large number of AF evaluation values by omitting the “wobbling” two or three times and omitting a low AF evaluation value may be performed, or a best AF evaluation value may be selected. The influence of a low AF evaluation value may be reduced by performing the averaging process. Thus A
By calculating the F evaluation value, display of an erroneous focus information display 70 due to camera shake or the like is avoided.

Further, as shown in FIG. 5, the control means 46 changes the range "Z" in which the in-focus display 74 is carried out in accordance with the change in the depth of field depending on the aperture amount of the aperture 28. Is also good. This makes it easier to adjust the focus when the aperture 28 is narrowed.

FIGS. 6 and 7 show flowcharts of the in-focus display processing of the camera.

The flowchart shown in FIG. 6 shows the case where the focus mode of the electronic camera 10 is set to the manual focus mode and the operating state detecting means 66 detects the non-operating state of the focus ring 14. It is shown as a subroutine called every time a synchronization signal is output. When the vertical synchronizing signal is output in the above state, the processing program of the control means 46 calls step S100 “MF determination start” (hereinafter abbreviated as S100), and
The process proceeds to the next S102 “brightness detection (AE detection)”.

In S102, the control means 46 controls the AE detected by the AE detection means 40 at the focus position P [n].
A process of reading the evaluation value and temporarily storing it in a storage unit such as the memory 38 in association with the focus position P [n] is performed.
In the next step S104 “Acquire AF evaluation value”, the control unit 46 sets the AF detection unit 4 at the focus position P [n].
2 reads the AF evaluation value calculated, and calculates the focus position P
A process of temporarily storing the data in a storage unit such as the memory 38 in association with [n] is performed. Then, the process proceeds to the next step S106, "Is the focus moved?" The evaluation values of the last time, the last time, and the previous time are stored by changing the suffixes, for example, P [nＰ1], P [n─2]. A
It is used when calculating the F evaluation value peak position).

In S106, it is determined whether or not the focus position is in an operating state in which the focus position is moving, or whether or not the focus position is in a non-operation state in which the focus position is not moving. if,
If it is in the operating state, the process branches to the judgment of S108 "No display?"
Proceed to 110 "Subject Change Determination" subroutine. When the subject change determination processing in S110 ends, the processing program proceeds to S124 “END” and ends the MF determination processing routine.

In S108, it is determined whether or not the focus information display 70 at the time of 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 processing” described later. If any one of the focus information displays 70 has already been displayed, S
Go to the determination of 114 "condition a & c1 (Near?)". In S114, it is determined whether or not the following conditions a and c1 are satisfied.

The condition a is shown below. The condition a determines whether the focus position (focus position) is closer to the near side (near side) than the peak position (imaging position), 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 obtained is P [n]. The AE evaluation value, which is the brightness of the subject at that time, is set to Ev [n].

When the following equation 1 is true, it means that the focus lens 26 is driven to the near side and the AF evaluation value decreases.

[0056]

P [n]> P [n-1]> P [n-2] & X [n] <X [n-1] <X [n-2] Expression 1 The following expression 2 is true. If it becomes, focus lens 2
6 is driven to the Far side and the AF evaluation value increases.

[0057]

P [n] <P [n-1] <P [n-2] & X [n]> X [n-1]> X [n-2] Expression 2 The condition c1 is shown below. The condition c1 is the focus information display 70
Is a condition for judging whether or not to display the focus information display 70 when is not displayed on the display means 18. When the following Expressions 3 and 4 are satisfied, "true" is set.

[0058]

X [n]> MF · LEVEL1 Expression 3 where MF · LEVEL1 is a threshold for determining the reliability of the AF evaluation value

[0059]

| X [n] −X [n−1] | / X ≧≧ MF · L · CON1 × | P [n] −P [n−1] | Equation 4 where X [n]: The current evaluation value X [n-1]: the previous evaluation value X: the larger one of X [n] and X [n-1] MF / L / CON1 is greater than the threshold value. If the condition a (the focus position is closer to the peak position than the peak position) and the condition c1 (display the focusing information display 70) are satisfied in S108, the process proceeds to S116 "N".
The control means 46 outputs a command to display the near display 76 on the display means 18. When the output of the command displayed in S116 ends, the processing program proceeds to S1.
Proceed to 24. If it is determined in step S114 that the conditions a and c1
If the condition b & c1 (F
ar? )].

In S118, it is determined whether or not the following condition b and condition c1 are satisfied.

The condition b is shown below. The condition b determines whether the focus position is located farther (far side) than the peak position, and is set to “true” when the following Expression 5 or Expression 6 is satisfied.

When the following equation (5) becomes true, it means that the focus lens 26 is driven to the near side and the AF evaluation value increases.

[0063]

P [n]> P [n-1]> P [n-2] & X [n]> X [n-1]> X [n-2] Expression 5 Expression 6 shown below is true. If it becomes, focus lens 2
6 is driven to the Far side, and the AF evaluation value decreases.

[0064]

P [n] <P [n-1] <P [n-2] & X [n] <X [n-1] <X [n-2] Expression 6 As described above, in S118, When the condition b (the focus position is located farther than the peak position) and the condition c1 (display the focusing information display 70) are satisfied, the step S120 “Far” is performed.
The control means 46 outputs a command for displaying 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 proceeds to S124 without performing the display instruction through S122 “do not display”.

When the peak detection processing is completed in the subroutine of S112, the processing program proceeds to S126 "Peak present?" To determine whether or not a peak indicating the in-focus position exists near the acquired AF evaluation value. Make a decision. If a peak exists, S200 “Aperture value (A
v) Acquisition ”. If no peak exists, the process proceeds to S128 “condition a & c2 (Near?)”.

In S128, it is determined whether or not the condition a and the following condition c2 are satisfied.

The condition c2 is shown below. Condition c2 is a condition for judging whether or not the subject has changed and the AF evaluation value has changed significantly when the focus position is away from the peak position, and the following Expressions 7 and 8 are satisfied. In this case, "true" is assumed.

[0068]

X [n]> MF · LEVEL2 (7) where MF · LEVEL2 is a threshold for judging the reliability of the AF evaluation value.

[0069]

| X [n] −X [n−1] | / X ≧≧ MF · L · CON2 × | P [n] −P [n−1] | Equation 8 where X [n]: Current evaluation value X [n-1]: Previous evaluation value X: Which takes the larger value of X [n] and X [n-1] If MF / L / CON2 is greater than the threshold, If the condition a (the focus position is on the side closer to the peak position) and the condition c2 (the AF evaluation value has significantly changed) are satisfied in S128, S130 is satisfied.
The process branches to the judgment of “Far being displayed?”. Also, if S1
If the conditions a and c2 are not satisfied at 28, S
The process proceeds to determination of 132 “condition b & c2 (Far?)”.

At S132, it is determined whether or not the condition b and the condition c2 are satisfied. If the condition b (the focus position is located farther than the peak position) and the condition c2 (the AF evaluation value has greatly changed) are satisfied in S132, the process branches to S134 "Near display?" . 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 not changed, and the next S124 is performed.
Proceed to.

At S130, the far display 72 is displayed on the display means 18.
Is being displayed. 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".
The control means 46 displays the near display 7 on the display means 18.
6 is output. When the output of the command displayed in S140 ends, the processing program proceeds to S124.

In S134, the near display 76 is displayed on the display means 18.
Is being displayed. If the near display 76 is not being displayed on the display means 18, the process branches to S124 without doing anything. 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 displays the far display 72 on the display means 18.
The command to display is output. When the output of the command to be displayed in S138 ends, the processing program proceeds to S124.

Next, the processing program shown in FIG. 7 will be described.

In S200, the control means 46 acquires the aperture value of the aperture 28 and sets the depth of field of the subject. N indicating the range of the permissible circle of confusion corresponding to this depth of field
[Av] value is calculated, and the next S202 “| P [n] −P
eak | <N [Av] Pulse? Proceed to the determination of S
In step 202, the distance of the focus position calculated based on the permissible circle of confusion (for example, when a stepping motor is used as the motor 54 for driving the focus lens 26,
When the movement amount of the focus lens 26 is managed by the number of pulses, the distance information in the range of the permissible circle of confusion becomes equal to the number of pulses.) N [Av] and the latest focus position P
[N] and the focus position "P
eak ”is compared with the distance.

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 determines in S204 "condition a & c2 (Near?)" Proceed to. If the determination in S202 is “true” (if the current focus position is within the depth of field with respect to the peak position), the processing program proceeds to S208 “condition a & c3 (Nea
r? )] ”.

In S208, it is determined whether or not the condition a and the following condition c3 are satisfied.

The condition c3 is shown below. Condition c3 is a condition for judging whether or not the subject has changed and the AF evaluation value has changed significantly when the current focus position is near the peak position, and when the following Expressions 9 and 10 are satisfied. To "true".

[0078]

X [n]> MF · LEVEL3 Expression 9 where MF · LEVEL3 is a threshold for determining the reliability of the AF evaluation value.

[0079]

| X [n] −X [n−1] | / X ≧≧ MF · L · CON3 × | P [n] −P [n−1] | Equation 10 where MF · L · CON3 If the condition a (the focus position is closer to the peak position) and the condition c3 (the AF evaluation value has greatly changed) are satisfied in S208 as in the case of the threshold or more, the process proceeds to S210 "Near display". Branch. If it is determined in step S208 that the conditions a and c
If S3 is not satisfied, S212 “conditions b & c3 (F
ar? )] ”.

At S212, it is determined whether or not the condition b and the condition c3 are satisfied. If the condition b (the focus position is located farther than the peak position) and the condition c3 (the AF evaluation value has greatly changed) are satisfied in S212, S214 "Far display"
Branch to Further, if the condition b and the condition c
If 3 is not satisfied, the process proceeds to S216 “focus display”, and the control unit 46 outputs a command to display the focus display 74 on the display unit 18. When the output of the command displayed in S216 is completed, the processing program proceeds to S124 shown in FIG.

In S210, the control means 46 displays the display means 1
8, a command to display the near display 76 is output. When the output of the command to be displayed in S210 ends, the processing program proceeds to the next S220 “Peak position reset”, and in response to determining that the subject has changed near the peak position,
A process of resetting the stored AF evaluation value and the focus peak position is performed, and the process proceeds to S124 shown in FIG.

In S214, the control means 46 displays the display means 1
8 to output a command to display the far display 72. When the output of the command to be displayed in S214 is completed, the processing program proceeds to the next S218 “reset peak position”, and in response to determining that the subject has changed near the peak position,
A process of resetting the stored AF evaluation value and the focus peak position is performed, and the process proceeds to S124 shown in FIG.

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 on the side closer to the peak position) and the condition c2 (the AF evaluation value has greatly changed) are satisfied in S204, the process branches to the determination of S222 "During Far display?" . Also, if the condition a
And if the condition c2 is not satisfied, S224 “condition b
& C2 (Far?) ".

At S224, it is determined whether or not the condition b and the condition c2 are satisfied. If the condition b (the focus position is located farther than the peak position) and the condition c2 (the AF evaluation value has greatly changed) are satisfied in S224, the process branches to S226 “Near display?”. 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.

In S222, the far display 72 is displayed on the display means 18.
Is being displayed. 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 S
232 "Reset peak position", in response to the change of the subject, performs a process of resetting the stored AF evaluation value and the focus peak position, and then proceeds to S234.

In S234, the control means 46 displays the display means 1
8, a command to display the near display 76 is output. When the output of the command to be displayed in S234 ends, the processing program proceeds to S124.

In S234, the near display 76 is displayed on the display means 18.
Is being displayed. 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 goes to S23.
2 The process proceeds to “Peak position reset”. In response to the change of the subject, the stored AF evaluation value and the focus peak position are reset, and the process proceeds to S230.

In S230, the control means 46 sets the display means 1
8 to output a command to display the far display 72. When the output of the command displayed in S230 is completed, the processing program proceeds to S124.

The focus information display 70 is displayed when the peak of the AF evaluation value is within the allowable circle of confusion. Since the permissible circle of confusion changes depending on the aperture, the focus position range for in-focus display is changed according to the aperture value.

FIG. 8 is a flowchart showing the processing of the subroutine for subject change determination shown in S110 of FIG.

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 S302 "condition d" determination.

In the judgment of S302, the focus mode of the electronic camera 10 is set to the manual focus mode, and the operation state detecting means 66 sets the focus ring 1
4 is an embodiment of a process of determining whether or not the subject has changed based on the AF evaluation value when the inoperative state of No. 4 is detected, and the condition d is satisfied when both the following Expressions 11 and 12 are satisfied. Is true.

The following equation (11) represents the operating state detecting means 6.
If the maximum value MAX and the minimum value MIN of the AF evaluation values acquired after the detection of the inactive state of the focus ring 14 satisfy the following conditions, it is determined that the subject may have changed. .

[0094]

(MAX−MIN) / MAX ≧ MF · CHG Expression 11 where MF · CHG indicates a threshold value The calculation of Expression 12 below is based on the reliability of the detection value when detecting that the subject has changed. It is implemented to evaluate the gender.

[0095]

MAX>MF> CHG · LVL Expression 12 where MF · CHG · LVL indicates a threshold. If the condition d is “false” in S302, the processing program proceeds to S304 “condition e”. Proceed to the determination of

In the judgment of S304, the focus mode of the electronic camera 10 is set to the manual focus mode, and the operation state detecting means 66 sets the focus ring 1
4 is an example of a process of determining whether or not the subject has changed based on the AE evaluation value when the non-operation state of the focus ring 1 is detected.
4 has been continuously detected, and the following equation 1
It is assumed that the condition e is “true” when the condition 3 is satisfied.

Expression 13 shown below represents the operating state detecting means 6
It is determined that the focus information display 70 needs to be changed because the subject may have changed due to a change in the AE evaluation value obtained after the focus ring 14 detected the inoperative state of the focus ring 14. I have.

[0098]

| Ev [n] −Ev [n−1] |> MF · EV · DIF where Ev [n]: current subject brightness Ev [n−1]: previous subject brightness MF EV · DIF indicates a threshold value. If condition e is “true” in step S304, or if condition d is “true” in step S302,
The processing program proceeds to S306 “Peak position reset peak value reset”, and upon determining that the subject has changed, performs a process of resetting the stored AF evaluation value, AE evaluation value, and focus peak position, and then performs S308.
The process proceeds to the “display OFF” process. In S308, the control unit 46 outputs a command to delete the focus information display 70 to the display unit 18. Here, the instruction to delete the focus information display 70 is:
It 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 ends the processing routine for subject change determination. Also, the above S30
Also in the case where the condition e is “false” in 4, the processing program proceeds to S310.

FIG. 9 is a flowchart showing the subroutine "peak detection processing" shown in S112 of FIG.

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 S402 “condition f” determination.

In the judgment of S402, the operation state detecting means 6
There are five types of ── evaluation values acquired immediately before detecting the non-operation state of the focus ring 14 or after detecting the non-operation state of the focus ring 14 when performing the operation of “wobbling”. The focus position is
It is determined whether or not it is near the peak position of the AF evaluation value of the subject.

It is assumed that the condition f is "true" when the following expression 14 or 15 and expression 16 are satisfied.

The following equation (14) shows a state where the focus lens 26 is continuously moved to the near side.

[0104]

P [n]> P [n-1]> P [n-2]> P [n-3]> P [n-4] Expression 14 In Expression 15, the focus lens 26 is continuous. Fa
The state moved to the r side is shown.

[0105]

## EQU15 ## P [n] <P [n-1] <P [n-2] <P [n-3] <P [n-4] Expression 15 If the following Expression 16 holds, AF It shows that the evaluation value has the shape shown in FIG.

FIG. 10 is a diagram showing AF evaluation values at each of the five focus positions measured by automatic or manual drive of the focus position. Although FIG. 5 illustrates an example in which five points are measured, the object of the present invention is achieved even if the focus peak is determined based on the AF evaluation values at three or more focus positions. Is done.

[0107]

X [n] <X [n-1] <X [n-2] && X [n-2]> X [n-3]> X [n-4] Expression 16 As a result of focusing determination based on five consecutive output changes, if the condition f is determined to be “true” in S402, the processing program sets S404 “peak position (Peak) storage peak presence flag ON”. Go ahead, A
Upon detecting the peak position of the F evaluation value, the AF evaluation value, the AE evaluation value and the peak position of the focus at the peak position are stored in the storage means, and the peak presence flag is stored. Then, the process proceeds to next S406 “In-focus display”,
The control means 46 outputs a command for displaying the focus indication 74 on the display means 18. When the display command is output in S406, the processing program proceeds to S408 "END", and ends the processing routine of the focus peak determination. In addition, the above S
Even when the condition f is “false” in 402, the processing program proceeds to S408.

In addition, the reliability judgment shown in the following equation 17 may be added to the above condition f.

When the following equation 17 is satisfied, it indicates that the peak of the peak of the AF evaluation value has high reliability.

[0110]

(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] | Equation 17 where MF · LCON2 indicates a threshold value

[0111]

As described above, according to the focus information display apparatus and method for a camera according to the present invention, in a focus information display apparatus for a camera that drives a focus lens based on an operation of a focus operation member, Imaging means for forming a subject image and outputting an imaging signal; focusing information detection means for detecting focusing information based on the imaging signal output by the imaging means; and a detection output of the focusing information detection means. Display means for displaying focus information based on the detection information, and a detection output of the focus information detection means changes when the focus operation member is not operated and focus information is displayed on the display means. Then, since the control means for changing the display of the focus information displayed on the display means is provided, it is easy to manually confirm and adjust the image forming position.

According to another aspect of the present invention, in a focusing information display device of a camera for driving a focus lens based on an operation of a focus operating member, an imaging means for forming an object image and outputting an imaging signal. Focusing information detecting means for detecting focusing information based on an imaging signal output by the imaging means; display means for displaying focusing information based on a detection output of the focusing information detecting means; A brightness information detecting means for detecting brightness information of a subject based on an imaging signal output by the means; and a focus information member when the focus operation member is not operated and focus information is displayed on the display means. A control means for changing the display of the focus information displayed on the display means when the detection output of the luminance information detection means changes, so that it is easy to manually confirm and adjust the image forming position. It made.

Further, according to the present invention, in order to reduce the power consumption of the camera, the wobbling operation for knowing the focusing direction is not performed, or the wobbling operation is performed in a limited manner. (Ie, when the focus lens is not moving), it is not possible to know the latest focusing direction for the subject or the like. Therefore, when the focus lens is not moving, and when it is considered that the subject has changed, the display content of the display means is changed so that an incorrect focusing direction or the like is not displayed. Makes it easy to confirm the image forming position.

Further, according to another aspect of the invention, since the focusing information stored in association with three or more lens positions is used, a more accurate focusing direction and focusing state can be detected. It is easy to confirm and adjust the imaging position.

[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 the electronic camera.

FIG. 4 is a diagram showing a display example of a focus display displayed on a display unit of the electronic camera.

FIG. 5 is a diagram showing a relationship between a focus position in a certain subject image and an acquired AF evaluation value.

FIG. 6 is a flowchart showing a method of displaying focus information of a camera.

FIG. 7 is a flowchart showing a method of displaying focus information of a camera.

FIG. 8 is a flowchart showing processing of a subroutine for subject change determination;

FIG. 9 is a flowchart showing a subroutine of a focus peak determination process;

FIG. 10 is a diagram showing each AF evaluation value at each focus position measured automatically five times.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Electronic camera, 12 ... Lens, 14 ... Focus ring, 18 ... Display means, 22 ... AF / MF switch, 26 ... Focus lens, 28 ... Aperture, 30 ... Image pickup means, 32 ... Image pickup circuit, 34 ... A / D converter, 36 bus, 38 memory, 40 AE detection means, 42 AF detection means, 46 control means, 48 motor, 50 zoom drive means, 52 zoom position detection means, 54 motor
56: Focus driving means, 58: HP sensor, 60:
Motor, 62: aperture control means, 64: HP sensor, 66
.. Operating state detecting means, 70... Focus information display, 72... Far display, 74... Focus display, 76... Near display, 78, 80...

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 5/225 G02B 7/11 D 5/232 G03B 3/00 A F term (Reference) 2H011 AA03 BA31 CA18 DA01 DA05 2H051 AA00 BA47 DA22 FA30 FA68 FA76 FA80 GA09 GA12 GA13 GA14 2H102 AA16 AA34 AA71 CA11 5C022 AA11 AB03 AB21 AB66 AB67 AC01 AC12 AC32 AC34 AC42 AC54 AC56 AC69 AC74

Claims (9)

[Claims] 1. A focusing information display device for a camera that drives a focus lens based on an operation of a focus operating member, wherein: an imaging unit that forms a subject image and outputs an imaging signal; A focus information detecting means for detecting the focus information based on the signal; a display means for displaying the focus information based on a detection output of the focus information detecting means; and And 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 while the focus information is displayed on the display means. A focus information display device for a camera, comprising: 2. A focus information display device for a camera that drives a focus lens based on an operation of a focus operation member, comprising: an imaging unit that forms a subject image and outputs an imaging signal; A focus information detecting means for detecting the focus information based on the signal; a display means for displaying the focus information based on a detection output of the focus information detecting means; and an image signal output by the imaging means. Brightness information detection means for detecting brightness information of a subject; and a detection output of the brightness information detection means changes when the focus operation member is not operated and focus information is displayed on the display means. Then, a control means for changing the display of the focus information displayed on the display means, and a focus information display device for a camera, comprising: 3. The camera according to claim 1, wherein the change of the display of the focus information by the control means is to delete the display of the focus information displayed on the display means. Focus information display device. 4. A focus information display device for a camera that drives a focus lens based on an operation of a focus operation member, wherein: an imaging unit that forms a subject image and outputs an imaging signal; and grasps a lens position of the focus lens. Focusing information detecting means, focusing information detecting means for detecting focusing information based on the output image signal in association with three or more lens positions detected by the positional grasping means, and the focusing information detecting means Storage means for storing the focus information detected by the camera, means for obtaining 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 focus lens. Display means for displaying focus information based on the lens position and focus detection information detected by the focus information detection means. Mera of-focus information display device. 5. The focus information detecting means detects focus information based on a result of the detection at the three or more lens positions a plurality of times. 5. The focus information display device according to claim 4, wherein the focus information is detected by omitting information of the image or reducing an influence of a blurred image by the averaging process. 6. The means for determining the position of the lens to be focused, determines whether or not there is a peak satisfying a predetermined criterion based on a change state of the focus information at three or more positions stored in the storage means. The lens position for focusing is obtained only when the peak exists.
Focusing information display device of camera. 7. The focus information detecting means determines whether or not the current lens position of the focus lens is within an allowable circle of confusion. 7. The focus information display device for a camera according to claim 4, wherein when it is determined that the lens position is within the permissible circle of confusion, focus information indicating that focus is achieved is displayed. 8. An image forming apparatus comprising: a stop for limiting the amount of light incident on the image pickup means; and a detecting means for detecting the stop amount of the stop, wherein the focus information detecting means detects a current focus detected by the detecting means. The display means determines whether or not the current lens position of the focus lens is within the allowable circle of confusion based on the aperture amount. 7. The focus information display device for a camera according to claim 4, wherein when it is determined that the camera is within the range, focus information indicating that focus is achieved is displayed. 9. A focus information display method for a camera that drives a focus lens based on an operation of a focus operation member, the focus information being obtained based on an image signal output by imaging an object image by an imaging unit. The focus information is displayed on the display unit based on the detected focus information, and the focus information is displayed on the display unit when the focus operation member is not operated. And changing the display of the focus information displayed on the display means if the detected focus information or luminance information changes in the case where the focus information is displayed.