JP2006208783A - Electronic camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic camera having an AF calibration function by which a general user can easily perform focus correction uniquely. <P>SOLUTION: The electronic camera picking up the image of a subject by a semiconductor imaging device has an ordinary photographing mode and a correction amount calculation mode different from the ordinary photographing mode. It has: a subject state discrimination means for discriminating a subject state in the correction amount calculation mode; a correction judging means for judging whether or not the correction is performed, based on a result by the subject state discrimination means; a correction amount calculation means for calculating/setting correction amount for performing the correction, based on a result by the correction judging means; a storage means for storing a result by the correction amount calculation means; and a focusing correction means for performing the focus correction, and has a warning means for giving a warning when judging that the appropriate correction is not performed according to the result by the correction judging means. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electronic camera, and more particularly to an electronic camera having a calibration function that allows a photographer to independently perform focus correction.

  Today's cameras are becoming more automated, and cameras with an auto-focus (AF) function that automatically focuses and an automatic exposure function that provides optimal exposure in various shooting scenes are common. As a result, the photographer is freed from the main and difficult operations of the camera such as focusing and determining exposure, and anyone can easily take high-quality photos.

  Recently, since the AF function has been improved and the evaluation of the photographer's focus level has been improved, the focus accuracy required by the photographer has come to be required.

  Therefore, it is necessary to provide an electronic imaging apparatus that can adjust the in-focus position of the imaging element more accurately and simply.

  In Patent Document 1, a camera having phase difference AF + contrast AF has a test mode different from the shooting mode, and in the test mode, AF data is respectively obtained from an AF sensor module and an image sensor arranged at conjugate positions. The relative deviation data of these AF data is stored, and in the photographing mode, the photographing lens is driven based on the AF relative deviation data.

That is, there is known an electronic camera that measures and records relative difference data of phase difference AF and contrast AF in the test mode and performs AF by adding the relative difference data to the phase difference AF in the normal photographing mode.
JP 2000-292684 A

  However, in the above proposal, it is necessary to prepare an adjustment facility for performing the focus adjustment. In a camera production site or a place where the camera is handled professionally, the equipment for performing the focus adjustment is prepared as such, but it is impossible for a general camera user to provide such equipment.

  Usually, in order to perform focusing adjustment, adjustment is performed using a dedicated chart.

  In general, a black and white stripe pattern is often used as a dedicated adjustment chart for performing AF adjustment. This is because using this chart makes it possible to perform focus adjustment with high accuracy.

  The purpose of the present invention is to make it possible for the user to easily perform AF calibration without the need for dedicated equipment. For this purpose, subject information is taken into account in advance, and only when the subject conditions can guarantee accuracy. Perform calibration.

  This is because the focus detection sensor also has conditions that make it good and bad depending on the brightness, color, pattern, etc. of the subject.

  A camera with an AF calibration function that makes it easy for anyone to adjust the focus by guiding the user to an adjustment state that can be used to adjust the focus with high accuracy. The purpose is to provide.

(Object of invention)
An object of the present invention is to accurately identify a subject and a shooting state, and to enable easy adjustment of focusing accuracy in a proper state by AF calibration of a camera, and provides comfortable operability. An object of the present invention is to provide a camera with an AF calibration function.

  According to a first object of the present invention, there is provided a camera with an AF calibration function capable of accurately identifying a subject state, performing optimum AF calibration control according to the subject state, and providing comfortable shooting operability. It is something to try.

  The second object of the present invention is to provide a camera with an AF calibration function that can accurately identify shooting conditions, perform optimum AF calibration control according to shooting conditions, and provide comfortable shooting operability. It is something to try.

  According to a third object of the present invention, an AF calibration function capable of accurately identifying the distance to the subject, performing optimal AF calibration control in accordance with the subject distance, and providing comfortable shooting operability is provided. Is to provide a camera.

  In the fourth and subsequent embodiments of the present invention, subject contrast, subject color, subject pattern, subject movement, subject distance, and distance to the subject are selected as parameters for subject state discrimination, and the ambient temperature, Select the posture difference and camera shake automatically and accurately, determine whether or not good AF calibration can be performed, and if not, warn or prohibit, and optimal AF calibration according to each state It is an object of the present invention to provide a camera with an AF calibration function that can perform comfortable control and provide comfortable operability.

In order to achieve the first object, the invention according to claim 1 has a correction amount calculation mode different from the normal shooting mode and the normal shooting mode,
In the correction amount calculation mode,
Subject state determination means for determining the subject state;
Correction determination means for determining whether correction can be performed based on the result of the subject state determination means;
Correction amount calculation means for calculating and setting a correction amount for performing correction based on the result of the correction determination means;
Storage means for storing the result of the correction amount calculation means;
Focusing correction means for performing focusing correction,
When it is determined that proper correction cannot be performed based on the result of the correction determination means, a camera with an AF calibration function with a function is provided which has a means for warning and prohibiting operation.

In order to achieve the second object, the invention according to claim 2 has a correction amount calculation mode different from the normal shooting mode and the normal shooting mode,
In the correction amount calculation mode,
Shooting state determining means for determining the shooting state of the camera;
Correction determination means for determining whether correction can be performed based on the result of the photographing state determination means;
Correction amount calculation means for calculating and setting a correction amount for performing correction based on the result of the correction determination means;
Storage means for storing the result of the correction amount calculation means;
Focusing correction means for performing focusing correction,
When it is determined that proper correction cannot be performed based on the result of the correction determination means, a camera with an AF calibration function with a function is provided which has a means for warning and prohibiting operation.

In order to achieve the third object, the invention according to claim 3 has a correction amount calculation mode different from the normal shooting mode and the normal shooting mode,
In the correction amount calculation mode,
Subject distance determining means for determining the distance to the subject;
Correction determination means for determining whether correction can be performed based on the result of the subject distance determination means;
Correction amount calculation means for calculating and setting a correction amount for performing correction based on the result of the correction determination means;
Storage means for storing the result of the correction amount calculation means;
Focusing correction means for performing focusing correction,
When it is determined that proper correction cannot be performed based on the result of the correction determination means, a camera with an AF calibration function with a function is provided which has a means for warning and prohibiting operation.

  In order to achieve the first object, the inventions according to claims 5 to 9 include subject contrast, subject color, subject pattern, subject movement, and distance to the subject as parameters for subject state discrimination. This is intended to provide a camera with an AF calibration function capable of providing a comfortable operability while performing AF calibration control corresponding to each state.

  In order to achieve the second object, the invention described in claims 10 to 12 selects the outside temperature, posture difference, and camera shake as parameters for determining the shooting state, and automatically determines with high accuracy, An object of the present invention is to provide a camera with an AF calibration function capable of performing AF calibration control in accordance with each state and giving comfortable operability.

  In order to achieve the first to fourth objects, the invention described in claim 13 displays warning display and prohibition display on the external display means.

  In accordance with the fourteenth aspect of the present invention, warning display and prohibition display are displayed on the display means inside the finder.

  According to the fifteenth aspect of the present invention, a warning is given to the warning and prohibition by the voice generation means.

  The invention described in claim 16 is characterized in that warning and prohibition are performed by vibrating the main body or a part thereof by vibrator means.

  The invention described in claim 17 is characterized in that the prohibition means prohibits the operation of AF calibration so that it cannot be performed.

  According to the present invention, the subject state, the photographing state, and the distance to the subject are identified, and the AF calibration function is provided that can perform the optimum AF calibration with high accuracy based on the result and provide comfortable operability. A camera can be provided.

  Hereinafter, the present invention will be described in detail based on illustrated embodiments.

  FIG. 1 is a block diagram showing the main part of a single-lens reflex camera according to the first embodiment of the present invention.

  In FIG. 1, 40 is a main body, 1 is a photographing lens (simply shown by only two lenses), a part 1a of the constituent lenses is a focusing lens for adjusting a focal position, and 1b is for blur correction. It is a shift lens and can be moved in a vertical plane on the drawing, so that a known camera shake correction can be performed by changing the imaging position in the imaging plane of the lens. Yes. Reference numeral 2 denotes a main mirror, which is obliquely set in the photographing optical path or retracted depending on the observation state of the subject image by the finder system and the photographing state of the subject image. Reference numeral 3 denotes a sub-mirror that reflects the light beam that has passed through the main mirror 2 toward a focus detection device 6 described below below the camera body. k is a photographing optical axis.

  Reference numeral 4 denotes a shutter, and reference numeral 5 denotes an image recording member which is a film or a solid-state imaging device located on the focal plane of the photographing lens 1. Reference numeral 6 denotes a focus detection device, which is a field mask 61, a field lens 62, reflection mirrors 63 and 66, a secondary imaging lens 65, an aperture 64, and a known phase difference detection type focus detection device arranged near the imaging surface. It consists of a line sensor 67 and the like. Recently, the focus detection device 6 has been provided with a plurality of focus detection points which are regions for focus detection not only in the center of the screen but also in the periphery thereof. Also in the present embodiment, a focus detection apparatus provided with such a plurality of focus detection points is assumed, but this is a known technique, and detailed description thereof will be omitted.

  Reference numeral 7 denotes a focusing plate disposed on the planned imaging plane of the taking lens 1, 8 denotes a field frame, and 9 denotes a pentaprism. Reference numerals 10 and 11 respectively denote an imaging lens and a photometric sensor for measuring the subject brightness in the viewfinder observation plane, and the photometric sensor 11 is composed of a plurality of photodiodes so that a plurality of areas in the screen can be measured. .

  Reference numeral 12 denotes a semi-transmissive mirror provided in the finder optical path. A part of the finder light is reflected upward in the drawing, and the subject imaged on the focus plate 7 by the imaging lens 13 on the known subject recognition area sensor 14. Reimage the image. On the other hand, the transmitted finder light is guided to the eyepiece lens 15 so that the photographer can enlarge the subject image.

  Reference numeral 16 denotes an in-viewfinder LCD for displaying photographing information outside the viewfinder field. Illumination is performed by the illumination LED 17 (F-LED), and the light transmitted through the LCD 16 is guided into the viewfinder by the triangular prism 18 to be out of the viewfinder field. The photographer can know the photographing information.

  Reference numeral 19 denotes a shake detection sensor which is a mechanical detection means such as a vibration gyro and is arranged so as to detect angular velocities in the pitch direction and the yaw direction with respect to the optical axis in order to detect camera shake of the photographer. In addition, the shake detection sensor 19 may be an acceleration detection sensor that detects acceleration.

  An attitude difference detection sensor 20 using a mercury switch is often used. Reference numeral 21 denotes a temperature / humidity detection sensor. A thermistor is often used as the temperature detection sensor, and a ceramic humidity sensor is often used for humidity detection.

  Reference numeral 22 denotes a diaphragm provided in the photographing lens 1, 23 denotes a diaphragm driving device, 24 denotes a focus lens driving motor, and 25 denotes a focus lens driving device including a driving gear. Reference numeral 26 denotes an encoder composed of a photocoupler and a pulse plate attached to the focus lens driving device 25. The encoder 26 detects the drive amount of the focus lens driving device 25 and transmits it to the lens control circuit 104. The lens control circuit 104 uses this information. Based on the information on the focus lens drive amount from the camera, the lens drive motor 24 is driven by a predetermined amount to move the focus lens 1a to the in-focus position.

  Reference numeral 27 denotes subject distance detection means provided for detecting the absolute position of the photographing lens 1 and obtaining the distance from the camera to the subject. For example, the subject distance detection means includes a code pattern of about 4 bits from the closest position to infinity, and is not shown. The object distance at the in-focus position can be detected using the brush contact. Reference numeral 28 denotes focal length detection means for detecting the focal length of the photographing lens 1, and it is possible to detect focal length information corresponding to a lens to be zoomed using a brush contact (not shown). Reference numeral 29 denotes a shift lens driving device that enables the blur correction lens to move on a vertical plane in the drawing, and drives this to perform blur correction. Reference numeral 30 denotes a shift lens lock / unlock drive means for fixing the shift lens 1b mechanically so as not to shift, or for making a shift within a predetermined range, a so-called free state. A mount contact 31 is an electrical interface between a known camera and lens.

  Reference numeral 32 denotes a rear display monitor for performing external display.

  FIG. 2 is a rear view of the camera body.

  41 is a power switch, 32 is a monitor display section, 42 is a viewfinder eyepiece, 43 is a sub-electronic dial, 44 is an opening / closing knob for opening a CF card slot cover for inserting a recording member such as a CF card, 45 is the above-mentioned A CF card slot cover 46 that is opened and closed by an open / close knob is a battery.

  FIG. 3 is a top view of the camera. 42 is a viewfinder eyepiece, 47 is a shooting mode selection switch, 48 is an AF mode selection switch, 49 is a metering mode selection switch, 50 is a top display panel, 51 is a main electronic dial for switching the shooting mode, shutter speed, exposure value, etc. , 52 are release switches.

  FIG. 4 is a block diagram showing a configuration of an electric circuit built in the single-lens reflex camera having the above configuration, and the same components as those in FIG. 1 are denoted by the same reference numerals.

  A microcomputer central processing unit (hereinafter referred to as a CPU) 101 of a microcomputer incorporated in the camera body includes a subject state identification circuit 101a, a subject state storage unit 101b, a camera photographing state identification circuit 101c, and a photographing unit. A state storage unit 101d, a subject distance identification circuit 101e, a subject distance storage unit f, and an EEPROM (not shown) for storing camera control parameters such as a shake correction parameter at the time of shake correction are provided. The CPU 101 is connected to the following various circuits for controlling various functions of the camera.

  The photometric circuit 102 amplifies the signal from the photometric sensor 11, performs logarithmic compression, A / D conversion, and transmits it to the CPU 101 as luminance information of each sensor corresponding to a plurality of areas in the screen. The focus detection circuit 103 performs AD conversion on the outputs from the plurality of sets of line sensors 67 so that phase difference focus detection can be performed at a plurality of positions in the screen, and transmits the converted signals to the CPU 101. The lens control circuit 104 disposed in the photographing lens 1 controls the focus lens driving device 25, the aperture driving device 23, and the shift lens driving device 28 based on control information from the CPU 101 via the mount contact 31. Control and further control of the shift lens lock / unlock drive means 30 is performed.

  The switch SW-1 is turned on by a first stroke of a release button (not shown) to start photometry, AF (autofocus), and a camera shake correction system. The switch SW-2 is turned on by the second stroke of the release button to start the release operation. Status signals of these switches and various switches (not shown) arranged at various positions of the camera are input to the SW signal input circuit 105 and transmitted to the CPU 101 via the data bus.

  The LCD driving circuit 106 has a known configuration for driving the display in the finder display LCD 17, the rear monitor display unit 32 for external display, and the upper display panel 211, and according to the signal from the CPU 101, the aperture value and shutter speed Display the set shooting mode. The shutter control circuit 107 controls the shutter magnet Mg-1 51 that travels the front curtain and the shutter magnet Mg-2 52 that travels the rear curtain when energized, and exposes the photosensitive member to a predetermined amount of light. The motor control circuit 108 is for controlling a motor M1 53 for winding and rewinding the film and a motor M2 54 for charging the main mirror 2 and the shutter 4. The shutter control circuit 107 and the motor control circuit 108 perform a series of camera release sequences.

  The sound generator 117 informs the photographer that there is an abnormality with a warning sound when warning information is issued.

  A vibrator 118 vibrates the entire body or a part of the body to warn the photographer.

  Here, in order to make the description easy to understand, a description will be given focusing on a circuit connected to a camera identification circuit configured in the CPU 101.

  First, the shake detection sensor 19 outputs vibrations in the pitch direction and yaw direction of the camera, and the shake detection circuit 111 passes this output through a high-pass filter to remove the bias component and the long-cycle drift component and extract the angular velocity due to camera shake. Thereafter, camera shake information is transmitted to the photographing state identification circuit as “Bure” data to the CPU 101.

  Next, the posture difference detection sensor 20 detects the posture state of the camera. In performing this AF calibration, the posture state of the camera body is important, and it is desirable to perform AF calibration at a substantially normal position. The posture difference detection circuit 110 determines the posture position of the camera, and transmits the posture information of the camera to the photographing state identification circuit as “Posture” data to the CPU 101.

  Next, the temperature / humidity detection sensor 21 will be described. The temperature / humidity detection sensor includes a temperature detection unit 21-a and a humidity detection unit 21-b, and measures the temperature / humidity of the outside. As the temperature sensor 21-a used at this time, a temperature detection sensor using a thermistor or a leaf switch for detecting a shape change of a thread-like shape memory alloy is used. The detected temperature data is captured by the temperature / humidity detection circuit 109 and transmitted as “Temp” data to the CPU 101 as external temperature information.

  Even in the humidity, the ambient humidity is detected by the humidity detection sensor 21-b. The humidity sensor 21-a includes a ceramic humidity sensor, a polymer humidity sensor, a thermal humidity sensor, and the like. The detected humidity data is captured by the temperature / humidity detection circuit 109 and is sent to the CPU 101 as “Humidi” data to the shooting state identification circuit. Transmit as external humidity information.

  Then, the photographing state identification circuit identifies the state of the camera by an algorithm described later together with other information. Then, the CPU 101 changes the focus position correction control such as changing the AF calibration correction operation based on the result.

  Next, the subject distance information and the focal length information of the photographing lens are supplied to the subject distance identification circuit 101e in the CPU 101 by the lens position detection circuit 112 from the signals of the subject distance detection means 27 and the focal distance detection means 28 provided in the photographing lens 1. It is designed to be entered.

  The subject recognition area sensor 14 is a color area sensor mainly having a number of pixels (approximately several hundred thousand pixels) necessary for detecting subject information, and includes a known CCD or C-MOS sensor. The circuit 113 is controlled by a known driving method. The subject image output to the sensor control circuit 113 is sent to the image processing circuit 114 for A / D conversion, and the subject state identification circuit 101a in the CPU 101 stores it in the subject state storage unit 101b of the memory unit as necessary. At the same time, image data is supplied to the subject identification circuit 115 according to a predetermined algorithm.

  The image processing circuit 114 outputs image data corresponding to a shooting screen to the subject identification circuit 115 and image data having a predetermined time difference to the subject image motion vector detection circuit 116. Then, for example, if the subject has a face, the subject identification circuit 115 recognizes the subject by portrait photography with a person, and if the entire image is black and white and a stripe pattern, the subject is a black and white chart for AF calibration.

  That is, an area that can be estimated as the main subject area is set in the screen, and is output to the subject state identification circuit 101a as subject identification information. The subject image motion vector detection circuit 116 compares the image data of the current field with the image data of the previous field stored in the subject state storage unit 101b for each of a plurality of areas in order to detect a motion vector in the screen. Then, the direction and amount of movement between fields are obtained. In this method, two-dimensional correlation calculation is performed from image data having a time difference, and a motion vector is detected from a shift amount in pixel units in which the correlation value is maximum. Thereby, motion vectors in a plurality of regions in the screen are obtained and output to the subject state identification circuit a.

  As described above, the temperature / humidity detection circuit 109, the posture difference detection circuit 110, the shake detection circuit 111, the lens position detection circuit 112, the subject recognition circuit 115, and the motion vector detection circuit 116 are connected to the CPU 101, and the respective states in the CPU 101 For the identification circuit, the camera shake information of the photographer, the subject identification information (the motion vector information of the subject image, the subject area information), the temperature / humidity information that is the shooting state (environment) of the camera, the posture difference information, and the focus of the lens Each piece of distance information is input.

  FIG. 5 is a flowchart showing the photographing operation of the camera of the embodiment of claim 1.

  First, in step # 101, when the power switch 41 is set to the ON mode, power is supplied to the camera, and a shooting preparation state is set. In the next step # 102, the mode selection switch 47 selects the normal shooting mode for normal shooting or the correction amount calculation mode for AF calibration. When the normal shooting mode is selected, the process proceeds to # 118, and when the correction amount calculation mode is selected, the process proceeds to # 103. In # 103, it is detected whether or not the switch SW-1 that is turned on by the first stroke of the release button 52 is ON. If it is ON, the process proceeds to step # 104, and if it is OFF, the detection in step # 103 is repeated.

  In step # 104, the output of the focus detection line sensor 67 is fetched, and the defocus amount of the selected focus detection point is calculated. In the subsequent step # 105, the CPU 101 sends a signal to the lens control circuit 104 to drive the focus lens by a predetermined amount according to the defocus amount, thereby adjusting the focus of the lens. Next, proceeding to step # 106, the CPU 101 causes the photometry circuit 102 to perform photometry. The photometric circuit 102 detects the luminance of the entire photometric area and performs a photometric calculation for weighting around the photometric area including the focused focus detection point, and inputs it to the CPU 101.

  In the next step # 107, subject information for identifying the subject state is read.

  Information on the subject is detected by the subject recognition area sensor 14 and the detected information is controlled by the sensor control circuit 113. The subject image output to the sensor control circuit 113 is sent to the image processing circuit 114 for A / D conversion, and the subject state identification circuit in the CPU 101 stores the subject state in the subject state storage unit as necessary, and a predetermined algorithm. Accordingly, the image data is supplied to the subject identification circuit 115.

  In addition, the subject motion vector detection circuit 116 detects the motion vector of the subject image from the subject image of the frame captured at the same time and the subject image of the next frame, and captures the motion vector in the subject state identification circuit.

  Next, in step # 108, the subject identification circuit performs a process for identifying the subject state. The identification parameters include subject contrast, subject color, subject pattern, subject movement, distance to the subject, and the like.

  Next, parameters for subject identification will be described.

  As a method for detecting the contrast of a subject, a block in which pixels accumulated in an imaging region are grouped in units of several pixels is formed, and reading is performed in units of the blocks. Comparing whether the brightness of each block is low brightness, medium brightness, or high brightness with a predetermined threshold, it is identified that the block area where the low brightness and high brightness areas occupy 50% or more of the shooting area. . For example, since the adjustment chart for performing the AF calibration uses black and white stripes, the black and white chart can be identified under the above identification conditions.

  As a subject color detection method, color feature amounts such as brightness, hue, saturation, chromaticity, and color difference are obtained from the R, G, and B values of each pixel of the area sensor 13. The feature amount obtained here is a feature amount in a color space in which a white region and a black region are to be determined. If the read pixel has a predetermined white and black range within a predetermined value or more, the target pixel is identified as a black and white stripe adjustment chart for performing AF calibration including a lot of white and black. Here, when performing color extraction, the photometric sensor 11 detects flicker, and correction is performed by a light source so that proper detection can be performed even if it is determined as a fluorescent lamp. Therefore, the same color extraction can be performed with any light source. It is possible to do.

  As a subject pattern detection method, a subject pattern appears based on the contrast distribution of the output of the area sensor 13.

  This subject pattern has a different distribution depending on the light intensity. Based on this, the distribution state of the adjustment chart used in the AF calibration is recognized in advance, and subject pattern detection is performed based on whether or not it can be recognized as being substantially equivalent to the adjustment chart.

  That is, a black and white stripe adjustment chart results in a striped subject pattern. It is also possible to store several types of chart patterns that are supposed to be used for adjustment and use them as identification criteria.

  As a method for detecting the movement of the subject, the proportion of the subject is not so large in order to check the motion of the subject, but the subject moves considerably. Therefore, here, an area of about 70% of the center in the screen is set as the initial recognition target region. Set parameters to limit. In order to detect motion, the area sensor 13 performs an accumulation operation, and reads the subject image in the region where motion detection is performed. Edge detection processing is performed on the image using only the G component as the luminance signal component from the R, G, and B values of each pixel of the read area sensor 13.

  If this value is larger than a predetermined threshold value, the target pixel is binarized as an edge pixel.

  The detected edge image is stored in a predetermined memory (not shown).

  The next frame image is read out. As described above, the edge detection process is performed on the image using only the G component as the luminance signal component.

The edge image of the previous frame is read from the memory, the correlation with the image of the current frame is calculated, and the motion of the image is detected based on the correlation value.
As a calculation formula, the image fi-1 (x, y) of the previous frame,
If the image fi of the current frame is fi (x, y), the shift amount ξ, η is min ΣΣ [fi−1 (x−ξ, y−η) −fi (fx, y)] 2 (1)
Or min ΣΣ | fi−1 (x−ξ, y−η) −fi (fx, y) |... (1) ′
And this will be sought.

  Specifically, two consecutive frames of images are compared, and this comparison is performed while shifting the reading position of the image data stored in the memory one pixel at a time.

  The sum of the differences between the two pixels is obtained, and the value is stored in a different area every time one pixel is shifted.

  The sum of the differences of each pixel is obtained by performing a bit comparison and counting the number of different bits.

  The same comparison is performed after the next line, and the sum of the differences of each pixel at that time is added to the area where the value of the first line is stored, and this becomes the correlation value.

The point where the correlation value is the smallest is obtained and used as the motion vector (motion amount) from the previous time in that region. That is, the number of pixels shifted in the vertical and horizontal directions when the correlation value is minimized is the amount of motion in the vertical and horizontal directions. Instead of such means, a projection image may be created in the horizontal direction and the vertical direction, and the motion vector may be obtained from the correlation value (movement amount of the center of gravity position).

  It is possible to construct a highly accurate AF calibration setting by selecting one or a plurality of conditions from the subject identification parameters described above.

  Proceeding to the next step # 109, the CPU 101 fetches the result from the subject identification circuit 115 into the identification information processing section (not shown) and performs processing according to the subject identification result.

  In step # 110, it is determined whether or not AF calibration can be corrected based on the subject information result. If correction is possible, the process proceeds to # 111 if the correction cannot be made to # 111.

  In # 111, the correction amount is calculated and set from the subject identification result.

  The correction amount data calculated in # 112 is stored in the correction amount storage circuit of the CPU 101.

  In step # 113, the shift lens is driven in accordance with the previously determined correction amount to focus the subject.

  Next, in step # 114, it is detected whether the switch SW-2 that is turned on by the second stroke of the release button is turned on. If it is turned off, the process returns to step # 106, and the above-described operation is repeated. On the other hand, if it is ON, the process proceeds to step # 115 to execute a camera release sequence.

  Specifically, first, the motor control circuit 108 energizes the motor M2 54 to raise the main mirror 2, and the lens control circuit 104 drives the aperture driving device 23 to narrow down to a predetermined opening. Next, the shutter control circuit 107 causes the shutter to run for a predetermined shutter time, and finishes capturing the image onto the image recording member. Thereafter, the motor M2 54 is energized again to perform mirror down and shutter charging, and also energize the motor M1 53.

  In step # 115, the captured image is confirmed. Check if the subject image in the new in-focus state by AF calibration was actually taken in the desired in-focus state, and if there is no problem, re-adjust by performing AF calibration again to # 116. If it is desired to perform the operation, the process returns to # 106 to repeat the series of operations.

  In step # 116, the confirmed image is stored in the memory. When it is desired to know the AF calibration information, detailed information can be obtained by reading this image.

  If the normal shooting mode is selected in # 102, the output of the focus detection line sensor 67 is fetched in # 118, and the defocus amount of the selected focus detection point is calculated. In the subsequent step # 119, the CPU 101 sends a signal to the lens control circuit 104 to drive the focus lens by a predetermined amount according to the defocus amount, thereby adjusting the focus of the lens. Next, proceeding to step # 120, the CPU 101 causes the photometry circuit 102 to perform photometry. The photometric circuit 102 detects the luminance of the entire photometric area and performs a photometric calculation for weighting around the photometric area including the focused focus detection point, and inputs the result to the CPU 101. Thereafter, the process proceeds to # 114 and the series of operations described above is repeated until # 116.

  If it is determined that the correction range is out of # 110 and the process proceeds to # 117, a warning is given to the photographer.

  Details of the warning means will be described below.

  FIG. 14 is a viewfinder display showing the first warning means.

  8 is a field frame, 321 is a focus detection point display, 322 is an in-focus mark, 323 is an AV display, 324 is a shutter speed display, 325 is the number of shots, and 326 is an AF calibration display indicating an AF calibration mode state. When the AF calibration is normally performed, correction is possible when the “CAL” mark of the AF calibration display 326 is lit, and when it is blinking, correction is not possible outside the correction range.

  In addition to the lighting and blinking, “NG” display is outside the AF calibration correction range, “OK” is within the AF calibration correction range, and “×”, “○” mark, etc. are also problematic. There is no.

  Next, the second warning means will be described.

  FIG. 13 shows in detail the liquid crystal display section of the upper surface display panel 50 on the upper surface of the camera in FIG.

  In FIG. 13, 301 is a standard shooting mode display section, 302 is an aperture value, 303 is a shutter speed, 304 is an AF mode display, 305 is a drive mode display section, 306 is an exposure step scale display, 307 is a battery level display, 308. Is a photometric mode display, and 309 is an AF calibration display.

  In this embodiment, when “CAL” is lit, it indicates that correction is possible, and blinking indicates that correction is impossible outside the correction range.

  As a display method other than lighting and blinking, “NG” display is outside the AF calibration correction range, “OK” is within the AF calibration correction range, and “×”, “○” mark and other display forms have no problem. There is no.

  Next, the third warning means will be described.

  FIG. 12 shows the monitor display unit 32 on the back of the camera body in detail.

  In FIG. 12, 310 is a captured image reproduction display monitor for displaying a captured image, 311 is a photographing shutter speed display, 312 is a photographing aperture display, 313 is an exposure correction amount, 314 is an AF calibration display, and 315 is selected at the time of photographing. 316 is an ISO sensitivity display selected at the time of shooting, 317 is a white balance mode displayed at the time of shooting, 318 is a shooting date and time, 319 is a file number of the shot image, and 320 is a histogram display.

  In this embodiment, when “CAL” is lit, it indicates that correction is possible, and blinking indicates that correction is impossible outside the correction range.

  As a display method other than lighting and blinking, “NG” display is outside the AF calibration correction range, “OK” is within the AF calibration correction range, and “×”, “○” mark and other display forms have no problem. There is no.

  Next, the fourth warning means will be described.

  As the fourth warning means, warning means other than display that is different from visual confirmation is warning means for warning the photographer with a warning sound from the sound generator 117 of FIG.

  When it is determined that the AF calibration cannot be corrected, a warning is issued with a warning sound from the sounding body.

  As the fifth warning means, the main body grip portion is vibrated by a vibrator to give a warning.

  By incorporating one or more of the above warning means, AF calibration correction can be performed smoothly.

  Next, an embodiment of AF calibration by the photographing state identifying means in claim 2 will be described.

  FIG. 6 is a flowchart showing the photographing operation of the AF calibration camera by the photographing state identifying means in claim 2.

  In # 601, it is detected whether or not the switch SW-1 that is turned on by the first stroke of the release button 52 is ON. If it is ON, the process proceeds to step # 602, and if it is OFF, the detection in step # 601 is repeated.

  In step # 602, the output of the focus detection line sensor 67 is taken in, and the defocus amount of the selected focus detection point is calculated. In subsequent step # 603, the CPU 101 sends a signal to the lens control circuit 104 to drive the focus lens by a predetermined amount in accordance with the defocus amount, thereby adjusting the focus of the lens. Next, proceeding to step # 604, the CPU 101 causes the photometry circuit 102 to perform photometry. The photometric circuit 102 detects the luminance of the entire photometric area and performs a photometric calculation for weighting around the photometric area including the focused focus detection point, and inputs it to the CPU 101.

  In the next step # 605, shooting state information to be used for identifying the shooting state is read.

In step # 606, the shooting state is identified from the read information.
The parameters for identifying the shooting state include environmental temperature and humidity at the time of shooting, camera posture difference, camera shake, and the like.

  Next, parameters for identifying the shooting state will be described.

  As a temperature and humidity detection method, temperature data detected by the temperature and humidity detection means described above is taken in by the temperature and humidity detection circuit 109 and transmitted as “Temp” data to the CPU 101 as external temperature information to the imaging state identification circuit 101 c. This is stored in the shooting state storage unit 101d.

  As for humidity, the detected humidity data is taken in by the temperature / humidity detection circuit 109, transmitted as “Humidi” data to the CPU 101 as external humidity information, and stored in the imaging state storage unit 101d.

  The photographing state identification circuit 101c determines whether or not satisfactory AF calibration can be performed based on the temperature and humidity threshold.

  As an attitude difference detection method, an attitude difference detection sensor 20 detects the attitude state of the camera. The attitude difference detection sensor 20 will be described using a well-known sensor using a mercury switch. Detailed illustrations will be omitted. When the camera body 40 is held in the horizontal position, one contact of the mercury switch is turned on to detect that the vertical / horizontal detector is in the horizontal position, and when held in the vertical position, the other contact is turned on to detect the vertical / horizontal detector. Is detected in the vertical position.

  In performing this AF calibration, the posture state of the camera body is important, and it is desirable to perform AF calibration at a substantially normal position. The posture difference detection circuit 110 determines the posture position of the camera, transmits the posture difference information of the camera to the photographing state identification circuit 101c as “Posture” data to the CPU 101, and stores it in the photographing state storage unit 101d.

  As a main body blur detection method, the blur detection sensor 19 outputs vibrations in the pitch direction yaw direction of the camera, and the blur detection circuit 111 passes this output through a high-pass filter to remove bias components and long-cycle drift components. After taking out the angular velocity due to the shake, camera shake information is transmitted to the shooting state identification circuit 101c as “Bure” data to the CPU 101 and stored in the shooting state storage unit 101d.

  From the above-described shooting state identification parameters, it is possible to select one or a plurality of conditions to construct a highly accurate AF calibration setting.

  Proceeding to next step # 607, the CPU 101 performs identification information processing on the result by the internal photographing state identification circuit 101c and performs processing according to the photographing state identification result.

  In step # 608, it is determined whether or not the AF calibration can be corrected based on the information result of the shooting state. If it can be corrected, the process proceeds to # 609. If the correction cannot be performed, the process proceeds to # 615.

  In # 609, the correction amount is calculated and set from the photographing state identification result.

  The correction amount data calculated in # 610 is stored in the photographing state storage unit 101d of the CPU 101.

  In step # 611, the shift lens is driven according to the previously determined correction amount to focus the subject.

  Next, in step # 612, it is detected whether the switch SW-2 that is turned on by the second stroke of the release button is turned on. If it is turned off, the process returns to step # 602 to repeat the above-described operation. On the other hand, if it is ON, the process proceeds to step # 613 to execute a camera release sequence.

  Specifically, first, the motor control circuit 108 energizes the motor M2, raises the main mirror 2, and the lens control circuit 104 drives the aperture driving device 22 to narrow it down to a predetermined opening. Next, the shutter control circuit 107 causes the shutter to run for a predetermined shutter time, and finishes capturing the image onto the image recording member. Thereafter, the motor M2 is energized again to perform mirror down and shutter charging, and also energize the motor M1.

In step # 613, the captured image is confirmed. If there is no problem after confirming that the subject image that has been brought into a new in-focus state by AF calibration was actually taken in the in-focus state desired by the user, if there is no problem, re-adjust by performing AF calibration again to # 614. If it is desired to perform the operation, the process returns to # 602 to repeat a series of operations.
In step # 614, the confirmed image is stored in the memory. When it is desired to know the AF calibration data, detailed information can be obtained by reading this image.

  If it is determined that the correction range is out of # 608 and the process proceeds to # 615, a warning is given to the photographer.

  As warning means, a display unit (see FIG. 14) outside the field of view in the viewfinder described earlier in claim 1, a top display panel display unit (see FIG. 13) at the top of the exterior of the main unit, and a rear surface of the main unit A warning is displayed on the monitor display section (see FIG. 12) in the section. Further, as a warning means other than the display, a means for urging the photographer to warn by sound from a sounding body or vibration by a vibrator is used.

  Next, an embodiment of AF calibration by the photographing state identifying means in claim 3 will be described.

  FIG. 7 is a flowchart showing the shooting operation of the camera for AF calibration by the shooting state identifying means in claim 3.

  In # 401, it is detected whether or not the switch SW-1 that is turned on by the first stroke of the release button 213 is turned on. If it is turned on, the process proceeds to step # 402. If it is turned off, the detection in step # 401 is repeated.

  In step # 402, the output of the focus detection line sensor 67 is fetched, and the defocus amount of the selected focus detection point is calculated. In subsequent step # 403, the CPU 101 sends a signal to the lens control circuit 104 to drive the focus lens by a predetermined amount in accordance with the defocus amount, thereby adjusting the focus of the lens.

In step # 404, the distance to the subject is calculated from the distance measurement result to the subject.
Description of the principle of the subject distance measurement method performed by the distance measuring unit is omitted because it is a known phase difference detection method.

  Next, the process proceeds to step # 405, and it is identified whether the main subject is dynamic or static based on distance measurement data that is considered to be the main subject. It is also identified at the same time whether or not the distance range is within which AF calibration can be performed.

  In step # 406, information processing is performed to determine whether AF calibration can be performed from the subject identification information. For example, if it is dynamic, it is not possible. It is determined whether or not the distance range in which AF calibration can be performed is not possible if the distance is close or telephoto.

  In step # 407, it is determined whether or not AF calibration can be performed from the subject distance information processing result.

  If AF calibration can be performed, the process proceeds to # 408, and if not, the process proceeds to # 415. In step # 408, a correction amount is calculated based on the subject distance information. Then, the correction amount calculated in # 409 is stored in the subject distance storage unit 101f in the CPU.

  In step # 410, the CPU 101 causes the photometry circuit 102 to perform photometry. The photometric circuit 102 detects the luminance of the entire photometric area and performs a photometric calculation for weighting around the photometric area including the focused focus detection point, and inputs it to the CPU 101.

  In the next step # 411, the shift lens is driven according to the previously determined correction amount to focus the subject.

  Next, in step # 412, it is detected whether the switch SW-2 that is turned on by the second stroke of the release button is turned on. If it is turned off, the process returns to step # 402 and the above-described operation is repeated. On the other hand, if it is ON, the process proceeds to step # 413 to execute a camera release sequence.

  Specifically, first, the motor control circuit 108 energizes the motor M2, raises the main mirror 2, and the lens control circuit 104 drives the aperture driving device 22 to narrow it down to a predetermined opening. Next, the shutter control circuit 107 causes the shutter to run for a predetermined shutter time, and finishes capturing the image onto the image recording member. Thereafter, the motor M2 54 is energized again to perform mirror down and shutter charging, and also energize the motor M1 53.

  In step # 413, the captured image is confirmed. Check if the subject image in the new in-focus state by AF calibration was actually taken in the desired in-focus state, and if there is no problem, go to # 414 and perform AF calibration again to readjust. If it is desired to perform the operation, the process returns to # 402 and a series of operations are repeated.

  In step # 414, the confirmed image is stored in the memory. When it is desired to know the AF calibration data, detailed information can be obtained by reading this image.

  If it is determined in # 407 that it is out of the correction range and the process proceeds to # 415, a warning is given to the photographer.

  As warning means, a display unit (see FIG. 14) outside the field of view in the viewfinder described earlier in claim 1, a top display panel display unit (see FIG. 13) at the top of the exterior of the main unit, and a rear surface of the main unit A warning is displayed on the monitor display section (see FIG. 12) in the section. Further, as a warning means other than the display, a means for urging the photographer to warn by sound from a sounding body or vibration by a vibrator is used.

  FIG. 8 is a flowchart showing details of the fourth embodiment.

  The fourth embodiment is a combination of the first, second, and third embodiments described above. First, the subject distance is identified, then the subject state is identified, and finally the shooting state is identified. Since AF calibration can be performed only when all parameters are satisfied, the most reliable adjustment condition can be provided.

  The details are the same as described above, so I will omit them.

  FIG. 9 is a flowchart showing details of the fifth embodiment.

  The fifth embodiment is a combination of the first and second embodiments described above. First, the subject state is identified, and then the shooting state is identified. Since AF calibration can be performed only when the parameters of the subject state and the photographing state are satisfied, it is possible to provide a higher adjustment condition than in the case of a single identification condition.

  The details are the same as described above, so I will omit them.

  FIG. 10 is a flowchart showing details of the sixth embodiment.

  The sixth embodiment is a combination of the first and third embodiments described above. First, the subject distance is identified, and then the subject state is identified. Since AF calibration can be performed only when the subject distance and subject state parameters are satisfied, it is possible to provide a higher adjustment condition than in a single identification condition.

  The details are the same as described above, so I will omit them.

  FIG. 11 is a flowchart showing details of the sixth embodiment.

  The seventh embodiment is a combination of the embodiments of claims 2 and 3 described above. First, the subject distance is identified, and then the shooting state is identified. Since AF calibration can be performed only when the subject distance and shooting state parameters are satisfied, it is possible to provide a higher adjustment condition than in a single identification condition.

  The details are the same as described above, so I will omit them.

  In the above-described embodiment, when the AF calibration cannot be performed, the warning means has issued a warning. However, not the warning but the AF calibration operation is prohibited, the operation prohibition display is performed on each display unit, The same effect can be obtained even by using a prohibiting means that prompts the photographer to readjust under appropriate conditions, such as a prohibition sound or a vibration for notifying operation.

  The present invention is not limited to the configuration of each of the embodiments described above, and any configuration can be used as long as the functions described in the claims or the functions of the embodiments can be achieved. It goes without saying that it is also good.

  Further, although the present invention has been described with reference to an example applied to a single-lens reflex camera, it can also be applied to various types of imaging devices such as a video camera and an electronic still camera.

Configuration diagram of a camera according to an embodiment of the present invention Rear view of the camera of FIG. Top view of the camera of FIG. 1 is a block diagram showing the configuration of the electric circuit of the camera in FIG. The flowchart which shows the 1st Embodiment of this invention The flowchart which shows the 2nd Embodiment of this invention. The flowchart which shows the 3rd Embodiment of this invention. The flowchart which shows the 4th Embodiment of this invention. The flowchart which shows the 5th Embodiment of this invention The flowchart which shows the 6th Embodiment of this invention. The flowchart which shows the 6th Embodiment of this invention. The figure which showed the back monitor display part of the camera of FIG. The figure which showed the upper surface display part of the camera of FIG. The figure which showed the display part in the finder of the camera of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shooting lens 8 Field frame 9 Penta 11 Photometric sensor 13 Subject recognition area sensor 19 Shake detection sensor 20 Attitude difference detection sensor 21 Temperature / humidity detection sensor 40 Camera 67 Focus detection line sensor 41 Main power switch 32 Rear monitor display section 47 Mode selection Switch 50 Upper surface display section 52 Release switches 123, 309, 326 AF calibration display section

Claims (18)

An electronic camera that images a subject using a semiconductor image sensor.
There is a correction amount calculation mode different from the normal shooting mode and the normal shooting mode,
In the correction amount calculation mode,
Subject state identifying means for identifying the subject state;
Correction determination means for determining whether correction can be performed based on the result of the subject state identification means;
Correction amount calculation means for calculating and setting a correction amount for performing correction based on the result of the correction determination means;
Storage means for storing the result of the correction amount calculation means;
Focusing correction means for performing focusing correction,
An electronic camera comprising warning means for giving a warning when it is determined that proper correction cannot be performed based on the result of the correction determination means. An electronic camera that images a subject using a semiconductor image sensor.
There is a correction amount calculation mode different from the normal shooting mode and the normal shooting mode,
In the correction amount calculation mode,
Photographing state identifying means for identifying the photographing state of the camera;
Correction determination means for determining whether correction can be performed based on the result of the photographing state identification means;
Correction amount calculation means for calculating and setting a correction amount for performing correction based on the result of the correction determination means;
Storage means for storing the result of the correction amount calculation means;
Focusing correction means for performing focusing correction,
An electronic camera comprising warning means for giving a warning when it is determined that proper correction cannot be performed based on the result of the correction determination means. An electronic camera that images a subject using a semiconductor image sensor.
There is a correction amount calculation mode different from the normal shooting mode and the normal shooting mode,
In the correction amount calculation mode,
Subject distance identifying means for identifying the distance to the subject;
Correction determination means for determining whether correction can be performed based on the result of the subject distance identification means;
Correction amount calculation means for calculating and setting a correction amount for performing correction based on the result of the correction determination means;
Storage means for storing the result of the correction amount calculation means;
Focusing correction means for performing focusing correction,
An electronic camera comprising warning means for giving a warning when it is determined that proper correction cannot be performed based on the result of the correction determination means. The electronic camera according to claim 1,
An electronic camera comprising prohibiting means for prohibiting a correction amount calculation mode when it is determined that proper correction cannot be performed as a result of the correction determining means.   An electronic camera, wherein the subject identification information of the subject identification means is subject contrast.   2. The electronic camera according to claim 1, wherein the subject identification information of the subject identification means is subject color information.   The electronic camera according to claim 1, wherein the subject identification information of the subject identification means is a subject pattern.   An electronic camera, wherein the subject identification information of the subject identification means is a movement of a subject.   An electronic camera, wherein the subject identification information of the subject identification means is a distance to the subject.   An electronic camera characterized in that the identification information of the photographing state identification means is the temperature and humidity of the outside world.   An electronic camera characterized in that the identification information of the photographing state identification means is a camera attitude difference.   An electronic camera characterized in that the identification information of the photographing state identification means is camera shake information.   The electronic camera characterized in that the warning means displays on an external display means.   An electronic camera according to claim 1, wherein the warning means performs display inside the finder by means of display means in the finder.   An electronic camera characterized in that the warning means issues a warning by voice by means of a dial tone means.   An electronic camera according to claim 1, wherein the warning means issues a warning by vibrating a main body of the camera or a part thereof by a vibrator means.   The electronic camera according to claim 1, wherein the prohibiting unit prohibits an AF calibration operation.   The electronic camera according to claim 1, wherein the prohibiting unit performs prohibition display on a display unit at the same location as the warning unit described above.

Images