JP5203657B2 - Camera with enlarged display function - Google Patents

Description

The present invention relates to enlarge function camera having a live view display function, particularly, a so-called live view display function for displaying an image acquired by the image sensor on a display device (through-image display function, also called electronic viewfinder function ) has, focus adjustment of the taking lens by utilizing the image signal in the live view display about the enlargement display function camera as possible.

In a conventional digital camera, an object image is observed using an optical viewfinder. However, recently, there has been proposed a digital camera with a live view display function that eliminates the optical finder or displays an image acquired by the image sensor together with the optical finder with a display device such as a liquid crystal monitor for observing the subject image. It is also commercially available.

For example, in Patent Document 1, in live view display, the movable mirror is retracted from the photographing optical path, the focal plane shutter is fully opened, and the subject image is guided to the image sensor, and the subject image obtained thereby is displayed. A digital single-lens reflex camera that is displayed on a liquid crystal monitor for observation is disclosed. Patent Document 2 discloses a camera having an enlarged live view display function for enlarging and displaying only a part of an image during live view display.
JP 2002-369042 A JP 2002-51239 A

Such an enlarged live view display function is very convenient for confirming a subject image. However, when a part of the live view display image is enlarged, if the enlarged display area is not in focus, that is, the image is greatly out of focus, End up. For this reason, there is a drawback that it is difficult to understand what the target is, which makes it difficult for the photographer to use.

The present invention has been made in view of such circumstances, and an object thereof is to provide a camera with easy to use larger display function.

In order to achieve the above object, a camera with a magnifying function according to a first aspect of the present invention receives a subject luminous flux incident through a photographing lens on an imaging surface and photoelectrically converts the subject image formed on the imaging surface to subject image. Imaging means for outputting data;
Using the subject image data acquired by the imaging means, it is possible to perform full-screen live view display that displays almost the entire area of the shooting screen and enlarged live view display that displays a specific area of the shooting screen in an enlarged manner. Yes, display means for switching the operation member in accordance with the operation of the operation member, contrast information in the latest subject image data output from the imaging means is obtained, and the first focusing permission of the photographing lens is obtained based on the contrast information. Contrast AF means for performing contrast AF control that leads to a second focus allowable range that is narrower than the first focus allowable range, or the contrast AF means. In conjunction with the start of the full-screen live view display, the photographic lens is guided within the first focus tolerance range and In conjunction with the operation member being operated to switch to the enlarged live view display, the photographing lens is guided to the second focus allowable range, and the operation member is operated again during the enlarged live view display. Thus, the contrast AF control is not performed even when the display is switched to the full-screen live view display.

According to the present invention, it is possible to provide an easy-to-use camera with a live view display function with enlarged display function.

Hereinafter, a preferred embodiment using a digital single lens reflex camera to which the present invention is applied will be described with reference to the drawings. FIG. 1 is an external perspective view of a digital single-lens reflex camera according to an embodiment of the present invention as seen from the back.

On the upper surface of the camera body 200, a release button 21, a shooting mode dial 22, an information setting dial 24, a strobe 200, and the like are arranged. The release button 21 has a first release switch that is turned on when the photographer is half-pressed and a second release switch that is turned on when the photographer is fully pressed. When the first release switch (hereinafter referred to as 1R) is turned on, the camera performs photographing preparation operations such as focus detection, focusing of the photographing lens, and photometry of the subject brightness, and the second release switch (hereinafter referred to as 2R). When it is turned on, a photographing operation for capturing image data of a subject image is executed based on the output of the image sensor 221 (see FIG. 2).

The shooting mode dial 22 is an operation member configured to be rotatable, and by matching a picture display or a symbol representing the shooting mode provided on the shooting mode dial 22 with an index, a full auto shooting mode (AUTO), a program Shooting mode (P), aperture priority shooting mode (A), shutter shooting priority mode (S), manual shooting mode (M), portrait shooting mode, landscape shooting mode, macro shooting mode, sports shooting mode, night scene shooting mode, etc. Each shooting mode can be selected.

The information setting dial 24 is an operation member configured to be rotatable, and a desired setting value, mode, or the like can be selected by rotating the information setting dial 24 on an information display screen or the like. The strobe 50 is a pop-up type auxiliary illumination device. By operating an operation button (not shown), the strobe 200 pops up and can irradiate the subject.

On the back of the camera body 200, there are a liquid crystal monitor 26, a continuous / single shooting button 27, an AF lock button 28, an up cross button 30U, a down cross button 30D, a right cross button 30R, and a left cross button 30L (these buttons). The cross buttons 30U, 30D, 30R, and 30L are collectively referred to as cross buttons 30), an OK button 31, a live view display button 33, an enlarge button 34, a menu button 37, and a playback button 38. . The liquid crystal monitor 26 is a display device that performs live view display, reproduces and displays a captured subject image, and displays shooting information and menus. Any liquid crystal display can be used as long as it can perform these displays.

The continuous shooting / single shooting button 27 is a continuous shooting mode in which continuous shooting is performed while the release button 21 is fully pressed, and a single shooting mode in which one frame is shot when the release button 21 is fully pressed. This is an operation member for switching. The AF lock button 28 is an operation member for fixing the focus of the subject. Thus, even if the composition AF is changed after the focusing AF lock button 28 is operated on the subject to be photographed to fix the focus, it is possible to perform photographing that is in focus on the photographing subject.

The cross button 30 is an operation member for instructing the movement of the cursor in the two-dimensional direction of the X direction and the Y direction on the liquid crystal monitor 26. In addition, when the subject image recorded on the recording medium is reproduced and displayed, Also used for image selection instructions. In addition to providing four buttons for up, down, left, and right, it is possible to replace with an operation member that can be operated in two dimensions, such as a switch that can detect the operation direction in two dimensions, such as a touch switch. It is. The OK button 31 is an operation member for confirming various items selected by the cross button 30, the control dial 24, or the like.

The live view display button 33 is an operation button for switching from a display screen for information display or the like to a live view display, or from a live view display to a display screen for information display or the like. The live view display is a mode in which the subject image is displayed on the liquid crystal monitor 26 for observation based on the output of the image sensor 221 for recording the subject image, and the information display is for setting the shooting information of the digital camera. This mode is displayed on the liquid crystal monitor 26. The enlargement button 34 is an operation member for enlarging and displaying a part of the subject image on the liquid crystal monitor 26, and the enlargement position can be changed by operating the cross button 30 described above.

The menu button 37 is an operation member for switching to a menu mode for setting various modes of the digital camera. When the menu mode is selected by operating the menu button 37, a menu screen is displayed on the liquid crystal monitor 26. . The menu screen has a plurality of hierarchical structures. Various items are selected with the cross-shaped button 30, and selection is determined by operating the OK button 31. The playback button 38 is an operation button for instructing the liquid crystal monitor 26 to display a subject image recorded after shooting. The subject image data stored in the later-described SDRAM 267 and recording medium 277 in a compression mode such as JPEG is expanded and displayed.

A recording medium storage lid 40 is attached to the side surface of the camera body 200 so as to be freely opened and closed. When the recording medium storage lid 40 is opened, a loading slot for the recording medium 277 is provided therein, and the recording medium 277 can be detachably loaded into the camera body 200.

Next, the overall configuration of the digital single-lens reflex camera mainly including the electric system will be described with reference to FIG. The digital single-lens reflex camera according to this embodiment includes an interchangeable lens 100 and a camera body 200. In the present embodiment, the interchangeable lens 100 and the camera body 200 are configured separately and are electrically connected by the communication contact 300, but the interchangeable lens 100 and the camera body 200 can also be configured integrally. . The circuit block of the built-in strobe 50 is omitted in FIG.

Inside the interchangeable lens 100, a photographing optical system 101 for focus adjustment and focal length adjustment, and a diaphragm 103 for adjusting the aperture amount are arranged. The photographing optical system 101 is driven by a lens driving mechanism 107, and the diaphragm 103 is connected to be driven by a diaphragm driving mechanism 109. The focal length and focal position of the photographing optical system 101 driven by the lens driving mechanism 107 are detected by the optical system position detection mechanism 105.

The lens driving mechanism 107, the aperture driving mechanism 109, and the optical system position detection mechanism 105 are each connected to a lens CPU 111, and the lens CPU 111 is connected to the camera body 200 via a communication contact 300. The lens CPU 111 controls the inside of the interchangeable lens 100. The lens CPU 111 controls the lens driving mechanism 107 to perform focusing and zoom driving, and also controls the aperture driving mechanism 109 to perform aperture value control. In addition, the lens CPU 111 transmits the focal length and focal position information detected by the optical system position detection mechanism 105 to the camera body 200.

In the camera body 200, a position tilted by 45 degrees with respect to the optical axis of the lens (the lowered position, the subject image observation position) in order to reflect the subject image to the observation optical system, and a subject image to be guided to the image sensor 221. A movable mirror 201 that can be rotated between the jumped up position (the raised position and the retracted position) is provided. Above the movable mirror 201, a focusing screen 205 for forming a subject image is disposed, and above this focusing screen 205, a pentaprism 207 for horizontally reversing the subject image is disposed.

An eyepiece lens (not shown) for observing the subject image is arranged on the emission side (right side in FIG. 2) of the pentaprism 207, and the photometric sensor 211 is arranged on the side of the pentaprism 207 so as not to interfere with the observation of the subject image. Has been. The photometric sensor 211 is connected to a photometric processing circuit 241, and the output of the photometric sensor 211 is subjected to processing such as amplification and analog-digital conversion by the photometric processing circuit 241.

Near the center of the movable mirror 201 described above is a half mirror, and on the back surface of the movable mirror 201, a sub mirror 203 for reflecting subject light transmitted through the half mirror portion to the lower part of the camera body 200 is provided. ing. The sub mirror 203 is rotatable with respect to the movable mirror 201. When the movable mirror 201 is flipped up (the position indicated by a broken line in FIG. 2), the sub mirror 203 is rotated to a position that covers the half mirror portion. When in the observation position (lowering position), it is in an open position with respect to the movable mirror 201 as shown.

This movable mirror 201 is driven by a movable mirror drive mechanism 239. A phase difference AF (Auto focus) sensor 243 is disposed below the sub mirror 203, and an output of the phase difference AF sensor 243 is connected to a phase difference AF processing circuit 245. The phase difference AF sensor 243 is a known phase difference that separates the light flux around the photographing optical system 101 into two light fluxes in order to measure the amount of focus shift (defocus amount) of the subject image formed by the photographing optical system 101. It consists of an AF optical system and a pair of sensors. Further, the phase difference AF sensor 243 can detect the focus at each of a plurality of points in the shooting screen.

A focal plane type shutter 213 for controlling the exposure time is disposed behind the movable mirror 201, and this shutter 213 is driven and controlled by a shutter drive mechanism 237. An imaging element 221 is disposed behind the shutter 213 and photoelectrically converts a subject image formed by the photographing optical system 101 into an electrical signal. The imaging element 211 may be a CCD (Charge Coupled Devices) or a CMOS (Complementary).
Needless to say, a two-dimensional image sensor such as Metal Oxide Semiconductor can be used.

The image sensor 221 is connected to the image sensor drive circuit 223, and the image sensor drive circuit 223 reads an image signal from the image sensor 221. The image sensor driving circuit 223 is connected to a preprocessing circuit 225. The preprocessing circuit 225 performs preprocessing for image processing such as pixel thinning processing for live view display and clipping processing for enlarged display. Do.

A dustproof filter 215, a piezoelectric element 216, and an infrared cut filter / low pass filter 217 are disposed between the shutter 213 and the image sensor 221. A piezoelectric element 216 is fixed around the dust filter 215, and this piezoelectric element 216 is vibrated by ultrasonic waves by a dust filter driving circuit 235. The dust attached to the dustproof filter 215 is removed by the vibration wave generated in the piezoelectric element 216.

The infrared cut filter / low pass filter 217 is an optical filter for removing the infrared light component and the high frequency component from the subject light flux. The dust filter 215, the piezoelectric element 216, the infrared cut filter / low pass filter 217, and the image sensor 221 are integrally formed in an airtight manner so that dust and the like do not enter. The integrated image sensor 223 and the like can be moved by the shift mechanism 233 along the X-axis direction and the Y-axis direction on the imaging surface of the image sensor 223, respectively.

The camera shake sensor 227 is a sensor that detects vibration caused by camera shake or the like applied to the camera body 200, and this output is connected to the camera shake correction circuit 229. The camera shake correction circuit 229 generates a camera shake correction signal for removing vibrations such as camera shake, and the output of the camera shake correction circuit 229 is connected to the shift mechanism drive circuit 231. The shift mechanism drive circuit 231 inputs a camera shake correction signal, and drives the shift mechanism 233 based on this signal. By this shift mechanism 233, the image pickup device 221 and the like are moved so as to cancel vibrations such as camera shake applied to the camera body 200, thereby performing vibration isolation.

The pre-processing circuit 225 is an ASIC (Application Specific
Integrated Circuit Application Specific Integrated Circuit) 250 is connected to a data bus 252 in the circuit. The data bus 252 includes a sequence controller (hereinafter referred to as “body CPU”) 251, an image processing circuit 257, a compression / decompression circuit 259, a video signal output circuit 261, an SDRAM control circuit 265, an input / output circuit 271, and a communication circuit 273. A recording medium control circuit 275, a flash memory control circuit 279, and a switch detection circuit 283 are connected.

The body CPU 251 connected to the data bus 252 controls the operation of this digital single lens reflex camera. A contrast AF circuit 253 and an AE circuit 255 are connected in parallel between the preprocessing circuit 225 and the body CPU 251 described above. The contrast AF circuit 253 extracts a high frequency component based on the image signal output from the preprocessing circuit 225, and outputs contrast information based on the high frequency component to the body CPU 251. The AE circuit 255 outputs photometric information corresponding to the subject brightness to the body CPU 251 based on the image signal output from the preprocessing circuit 225.

The image processing circuit 257 connected to the data bus 252 is a variety of images such as digital amplification (digital gain adjustment processing) of digital image data, color correction, gamma (γ) correction, contrast correction, and live view display image generation. Perform processing. The compression / decompression circuit 259 is a circuit for compressing the image data stored in the SDRAM 267 by a compression method such as JPEG or TIFF. Note that image compression is not limited to JPEG or TIFF, and other compression methods can be applied.

The video signal output circuit 261 is connected to the liquid crystal monitor 26 via the liquid crystal monitor drive circuit 263. The video signal output circuit 261 is a circuit for converting the image data stored in the SDRAM 267 and the recording medium 277 into a video signal for display on the liquid crystal monitor 26. As shown in FIG. 1, the liquid crystal monitor 26 is disposed on the back surface of the camera body 200. However, the liquid crystal monitor 26 is not limited to the back surface as long as the photographer can observe the image. .

The SDRAM 267 is connected to the data bus 261 via the SDRAM control circuit 265, and the SDRAM 267 temporarily stores the image data processed by the image processing circuit 257 or the image data compressed by the compression / decompression circuit 259. This is a buffer memory.

The above-described image sensor driving circuit 223, preprocessing circuit 225, camera shake correction circuit 229, shift mechanism driving circuit 231, dustproof filter driving circuit 235, shutter driving mechanism 237, movable mirror driving mechanism 239, photometry processing circuit 241, phase difference AF processing An input / output circuit 271 connected to the circuit 245 controls data input / output with each circuit such as the body CPU 251 via the data bus 252.

The communication circuit 273 connected to the lens CPU 111 via the communication contact 300 is connected to the data bus 252 and exchanges data and communicates control commands with the body CPU 251 and the like. A recording medium control circuit 275 connected to the data bus 252 is connected to the recording medium 277 and controls recording of image data and the like on the recording medium 277 and reading of the image data and the like.

The recording medium 277 can be loaded with any rewritable recording medium such as an xD picture card (registered trademark), a compact flash (registered trademark), an SD memory card (registered trademark), or a memory stick (registered trademark). And is detachable from the camera body 200. In addition, the hard disk may be configured to be connectable via a communication contact.

The flash memory control circuit 279 is connected to a flash memory 281, and the flash memory 235 stores a program for controlling the operation of the digital single-lens reflex camera, and the body CPU 251 stores the program in the flash memory 281. The digital single lens reflex camera is controlled according to the stored program. Note that the flash memory 281 is an electrically rewritable nonvolatile memory.

Various switches including a 1R switch for detecting the first stroke (half press) of the shutter release button 21, a 2R switch for detecting the second stroke (full press), and a live view display switch that is turned on by operating the live view display button 33 285 is connected to the data bus 252 via the switch detection circuit 283. The various switches 285 include an enlargement switch linked to the enlargement button 34, a power switch, a menu switch linked to the menu button 37, an AF lock switch linked to the AF lock button 28, and a continuous / single shot button 27. It includes a continuous / single-shot switch and other various switches linked to other operation members.

Next, the operation of the digital camera in one embodiment of the present invention will be described using the flowcharts shown in FIGS. FIG. 3 shows a power-on reset operation by the body CPU 251 on the camera body 200 side. When a battery is loaded in the camera body 200, this flow starts, and it is first determined whether the power switch of the camera body 200 is on (# 1). If the result of the determination is that the power switch is off, it enters a sleep state that is a state of low power consumption (# 3). In this sleep state, interrupt processing is performed only when the power switch is turned on, and processing for turning on the power switch is performed in step # 5 and subsequent steps. Until the power switch is turned on, operations other than power switch interrupt processing are stopped to prevent the power battery from being consumed.

In step # 1, if the power switch is on, or if the sleep state is canceled in step # 3, power supply is started (# 5). Next, a dust removing operation is performed in the dust filter 215 (# 7). In this operation, a driving voltage is applied from the dust filter driving circuit 235 to the piezoelectric element 216 fixed to the dust filter 215, and dust and the like are removed by ultrasonic vibration waves.

Next, if there is information such as the photographing mode set by the photographing mode dial 22 or the like, ISO sensitivity, manually set shutter speed or aperture value, those photographing conditions and lens information are read (# 9). . The lens information is read from the lens CPU 111 through the communication circuit 273 to read lens characteristic information such as the open aperture, focal length information, and lens identification number of the interchangeable lens 100.

Subsequently, photometry / exposure amount calculation is performed (# 11). In this step, the subject brightness is measured by the photometric sensor 211, an exposure amount is calculated, and exposure control values such as a shutter speed and an aperture value are calculated according to the shooting mode and shooting conditions using the exposure amount. Thereafter, the photographing information is displayed on the liquid crystal monitor 26 (# 13). The shooting information includes the shooting mode and shooting conditions read in step # 9, and the shutter speed and aperture value exposure control values calculated in step # 11.

Next, it is determined whether or not the live view display switch is on (# 15). As described above, when the photographer observes the subject image in the live view display, the live view display button 33 is operated. If the result of determination is that the live view display switch is on, a live view display operation subroutine is executed (# 31). This live view display operation will be described later with reference to FIGS.

If the result of determination in step # 15 is that the live view display switch is not on, it is determined whether or not the playback switch is on (# 17). The playback mode is a mode in which the still image data recorded on the recording medium 277 is read and displayed on the liquid crystal monitor 26 when the playback button 38 is operated. If the result of determination is that the regeneration switch is on, regeneration operation is executed (# 33).

If the result of determination in step # 17 is that the playback switch is not on, it is determined whether or not the menu switch is on (# 19). In this step, it is determined whether the menu button 37 is operated and the menu mode is set. If the result of determination is that the menu switch is on, a menu is displayed on the liquid crystal monitor 26 and menu setting operation is performed (# 35). Various setting operations such as AF mode, white balance, ISO sensitivity setting, and drive mode setting can be performed by the menu setting operation.

If the result of determination in step # 19 is that the menu switch is not on, it is determined whether or not the release button 21 has been pressed halfway, that is, whether or not the 1R switch is on (# 21). If the result of determination is that the 1R switch is on, a subroutine for shooting operation A for shooting preparation and shooting is executed (# 37). Details of this subroutine will be described later with reference to FIG.

If the result of determination in step # 21 is that the 1R switch is not on, it is determined whether or not the power switch is on as in step # 1 (# 23). If the result of determination is that the power switch is on, processing returns to step # 9 and the above operation is repeated. On the other hand, if the power switch is not on, the power supply is stopped (# 25), the process returns to step # 3, and the above-described sleep state is entered.

Next, the live view display operation in step # 31 will be described with reference to FIGS. When this subroutine is entered, first, the photographing information display is turned off (# 41). In step # 13, the shooting information is displayed on the liquid crystal monitor 26. In this step, the display of the shooting information is stopped in order to display the live view on the liquid crystal monitor 26. Subsequently, in the same manner as in step # 11, photometry / exposure amount calculation is performed (# 43).

Next, the movable mirror 201 is retracted from the optical axis of the photographing optical system 101 (# 45), and the shutter 213 is opened (# 47). By these operations, a subject image by the photographing optical system 101 is formed on the image sensor 221. Subsequently, live view condition initial setting is performed (# 49). In this step, in order to set the electronic shutter speed and sensitivity conditions for driving the image sensor 221, the brightness (appropriate brightness) for the liquid crystal monitor 26 is obtained using the photometry / exposure amount calculation result obtained in step # 43. Calculation and setting for displaying an image of brightness.

Next, the start of live view display is instructed (# 51). That is, the image sensor 221 and the image processing circuit 257 are instructed to display the image data acquired by the image sensor 221 on the liquid crystal monitor 26 as a moving image. The photographer can determine the shooting composition based on the live view display. Note that the electronic shutter speed, ISO sensitivity, and the like are controlled so that the screen brightness of the liquid crystal monitor 26 is constant during live view display. Subsequently, contrast AF control is executed (# 52). In this subroutine, image data for live view display is used and the focus adjustment operation is controlled based on the contrast information output from the contrast AF circuit 253 so that the photographing optical system 101 is in focus. The details of this contrast AF control will be described later with reference to FIGS.

When live view display is started, it is next determined whether or not the release button 21 has been half-pressed, that is, whether or not the 1R switch is on (# 53). If the result of determination is that the 1R switch has not been turned on, it is determined whether or not the enlargement button 34 has been operated, that is, whether or not the enlargement switch has been turned on (# 55). As a result of the determination, if the enlargement switch is not on, the process jumps to step # 71 (FIG. 5). On the other hand, if the enlargement switch is on, it is determined whether or not enlargement display is being performed ( # 57).

As described above, the enlargement button 34 is an operation button for enlarging and displaying a subject image in the live view display mode. When the enlargement button 34 is operated once, the enlargement display mode is set. The enlarged display mode is canceled. Therefore, in step # 57, it is determined whether to continue or end the enlarged display mode.

If the result of determination in step # 57 is that enlarged display is not in progress, that is, from the full-screen live view display mode (non-enlarged display mode, normal live view display mode) in which live view display is performed for almost the entire area of the shooting screen. In the enlarged display mode, the cutout range is instructed (# 59), and the start of enlarged display is instructed (# 61). The enlarged display is performed by instructing the preprocessing circuit 225 and cutting out image data corresponding to the enlarged range from the image data read from the image sensor 221. Subsequently, contrast AF control is performed using the image data used in the enlarged display in step # 61 (# 62). In this step, contrast AF control is performed so that the subject being magnified is focused. Details will be described later with reference to FIGS. 10 and 11.

If the result of determination in step # 57 is that enlarged display is in progress, the enlarged display mode is terminated and processing for returning to full-screen live view display is performed. That is, a full screen output instruction is given to the preprocessing circuit 225 (# 63), and an enlargement display stop instruction is given to the image processing circuit 257 (# 65). When the processing of step # 62 or # 65 ends, the process proceeds to step # 71, and it is determined whether or not the cross button 30 has been operated.

If the result of determination in step # 71 is that the cross button 30 has been operated, it is next determined whether or not enlarged display is in progress (# 73). As a result of the determination in Step # 71 or Step # 73, if either is N, the process jumps to Step # 77. If the determination in both steps is Y, that is, in enlarged display. If the cross switch is operated, the movement of the enlargement area corresponding to the cross button 30 is instructed (# 75).

As described above, in this embodiment, when the live view display mode is entered, the subject image is displayed on the full screen on the liquid crystal monitor 26 as shown in FIG. 13A (# 51). When the enlarge button 34 is operated in this state (# 55), the subject image is enlarged and displayed as shown in FIG. 13B (# 61). This enlarged display is a part of the full screen display as shown in FIG. Thereafter, when the cross button 30 is operated (# 71), an enlarged display is performed at a position corresponding to the operation of the cross button 30 (# 75). The enlarged display at this time corresponds to a position corresponding to the operation of the cross button 30 in a part of the full screen display as shown in FIG. Note that, when the enlarged display is performed, since the contrast AF control is performed in step # 62, the focused image is obtained.

Next, it is determined whether or not the live view display switch linked to the live view display button 33 is ON (# 77). Once the live view display button 33 is operated, the live view display mode is set. When the live view display button 33 is operated again, the live view display mode is canceled. If the result of determination in step # 77 is on, the live view display mode is terminated in step # 85 and thereafter.

If the result of determination in step # 77 is that the live view display switch is not on, it is determined whether or not the playback switch linked to the playback button 38 is on (# 79). In the reproduction mode, it is necessary to end the live view display mode in order to reproduce and display the image data recorded on the recording medium 277 on the liquid crystal monitor 26. If the result of determination in step # 79 is on, the live view display mode is terminated in step # 85 and thereafter.

If the result of determination in step # 79 is that the playback switch is not on, it is determined whether or not the menu switch linked to the menu button 37 is on (# 81). In the menu setting mode, in order to display the menu on the liquid crystal monitor 26, it is necessary to end the live view display mode. If the result of determination in step # 81 is on, the live view display mode is terminated in step # 85 and thereafter.

If the result of determination in step # 81 is that the menu switch is not on, it is determined whether or not the power switch is on (# 83). If the result of determination is that the power switch is off, in order to perform power off processing, live view display is first terminated in step # 85 and thereafter. If the result of determination in step # 83 is on, processing returns to step # 53 and the above operation is repeated.

When the process proceeds to step # 85 to end the live view display, the focus display is first turned off (# 85). As will be described later, when the subject is in focus, the first in-focus display 311 and the second in-focus display 312 are displayed as shown in FIGS. If so, turn it off. Subsequently, a live view display stop instruction is given to the pre-processing circuit 225, the image processing circuit 257, etc. (# 87). After that, the shutter 213 is instructed to close the shutter (# 89), the movable mirror 201 is returned (moved to the lowered position) (# 91), and the process returns to the original routine.

If the result of determination in step # 53 (FIG. 4) is that the 1R switch is on, AE information is read (# 101, FIG. 6). In step # 43, since the movable mirror 201 was in the lowered position, the photometric sensor 211 was able to perform photometry. However, in this step, the movable mirror 201 is in the retracted position (upward position). Photometry with 211 is not possible. Therefore, AE information is acquired based on the output of the AE circuit 255.

Subsequently, it is determined whether or not the phase difference AF only mode is set (# 103). The AF mode can be selected on the AF mode selection screen (see FIG. 14) in the menu setting operation in step # 35. That is, in this embodiment, the i-AF mode that performs only contrast AF based on the output of the image sensor 221, the PD-AF mode that performs only phase difference AF based on the output of the phase difference AF sensor 243, and the contrast AF and level. Either i-AF + PD-AF mode in which both phase difference AF is performed can be selected.

If the result of determination in step # 103 is phase difference AF only mode, the process jumps to step # 107. On the other hand, if the result of determination in step # 103 is not phase difference AF only mode, contrast AF control is performed (# 105). In this contrast AF control, as described above, based on the contrast information from the contrast AF circuit 253, the photographing optical system 101 is controlled to be in focus. In the enlarged live view display (# 53 → # 55), the contrast AF control is performed using the image data for enlarged display. However, in step # 105, the full screen live view display (non-enlarged live view) is performed. Therefore, contrast AF control is performed using image data for full screen display. The details of this contrast AF control will be described later with reference to FIGS.

Next, it is determined whether the release button 21 is fully pressed, that is, whether the 2R switch is turned on (# 107). If the result of determination is that it is not on, processing returns to step # 53 and the above steps are repeated. On the other hand, if it is on, the photographing operation is executed in step # 109 and thereafter.

When the shooting operation is started, the live view display is first stopped (# 109). Subsequently, the shutter 213 is closed (# 111). During live view display, the shutter 213 is opened and the subject image is displayed on the liquid crystal monitor 26 based on the output of the image sensor 221, but the shutter 213 is temporarily closed in order to start the photographing operation.

Next, it is determined whether or not the second focus display is being performed (# 113). In the contrast AF control subroutine, the first contrast AF control that guides the taking lens into the first focus allowable range and the second focus AF range that is narrower than the first focus allowable range. When the second contrast AF control can be executed and the second contrast AF control is completed, the second focus display is performed (# 277 in FIG. 11 and FIG. 15B). ). In step # 113, it is determined whether or not this highly accurate second in-focus state is reached.

In step # 113, if the second focus display is not being performed, it is determined whether or not the phase difference AF unnecessary condition is satisfied (# 115). The phase difference AF unnecessary conditions are as follows: (1) the focal length of the photographic lens is on the wide angle side from a predetermined value, (2) the aperture value is greater than or equal to a predetermined value (small aperture diameter), and (3) the subject distance is greater than the predetermined distance This is a case where the depth of field is wider than the first focus allowable range due to the reason of being on the far side. That is, when these conditions are satisfied, it is considered that sufficient focusing accuracy can be obtained only by the first contrast AF control, so that it is not necessary to further perform highly accurate phase difference AF.

If the phase difference AF unnecessary condition is not satisfied in step # 115, it is determined whether or not the AF lock switch linked to the AF lock button 28 is on (# 117). If the result of determination is that the AF lock switch is not on, phase difference AF is performed in step # 119 and thereafter. That is, if all of the determination results in steps # 113, # 115, and # 117 pass N, high-precision AF is performed by phase difference AF.

In order to perform phase difference AF, first, the movable mirror 201 is returned and inserted into the optical path of the photographing optical system 101 (# 119). As a result, the subject light flux for phase difference AF is guided to the phase difference AF sensor 243. Subsequently, phase difference AF control is performed (# 121). In this step, the focus shift direction and the focus shift amount of the photographing optical system 101 are detected by a known phase difference AF, and the drive control of the optical system drive mechanism 107 is performed based on the focus shift direction and the focus shift amount. The system 101 is focused. Details will be described later with reference to FIG.

When the phase difference AF control is finished, the movable mirror 201 is moved to the raised position, that is, retracted (# 123). As a result, the subject light flux that has passed through the photographing optical system 101 is again guided to the image sensor 221 and forms an image on the image sensor 221.

If the result of determination in steps # 113 and # 115 described above passes both in Y, it is not necessary to perform high-precision AF by phase difference AF. Also, as a result of determination in step # 117, AF lock When the switch is on, the photographer has already determined the in-focus position, so that the in-focus position is not changed by the phase difference AF. The focus display is turned off (# 127). When step # 123 or step # 127 is completed, a shooting operation B for acquiring and recording image data based on the subject image is performed (# 125). This photographing operation B will be described later with reference to FIG. When the shooting operation B is completed, the process returns to step # 43, the live view display is resumed, and the above-described operation is repeated.

Next, a sub-routine of the photographing operation A in step # 37 will be described using FIG. This photographing operation A is a subroutine executed when the release button 21 is half-pressed in the normal optical viewfinder observation state (that is, non-live view display). When the shooting operation A subroutine is entered, first, shooting information display is turned off (# 131). Subsequently, as in step # 121, a phase difference AF control subroutine is executed (# 133). That is, the focus shift direction and the focus shift amount are obtained based on the output of the phase difference AF sensor 243, and the photographing optical system 101 is focused. Details of this subroutine will be described later with reference to FIG.

When the phase difference AF ends, photometry / exposure amount calculation is performed in the same manner as in step # 11, and exposure control values such as shutter speed and aperture value are obtained (# 135). Subsequently, it is determined whether or not the shutter button 21 has been fully pressed, that is, whether or not the 2R switch is on (# 137). If the result of determination is that the 2R switch is not on, it is determined whether or not the 1R switch is on (# 157). If the result of determination is that the 1R switch is not on, the shooting operation A is terminated and the original routine is returned to. On the other hand, if the result of determination is that the 1R switch is on, the flow returns to step # 137 to enter a standby state for detecting the state of the 1R switch and 2R switch.

If the result of determination in step # 137 is that the 2R switch is on, the routine proceeds to step for shooting. First, the movable mirror 201 is retracted (moved to the raised position) (# 139). As a result, the subject light flux by the photographing optical system 101 is guided onto the image sensor 221 to form an image. Subsequently, the lens CPU 111 is instructed to perform a narrowing operation (# 141), and the amount of narrowing is also instructed (# 143).

Now that the preparation for entering the imaging operation is completed, the exposure operation is started (# 145). In the exposure, the traveling of the front curtain of the shutter 213 is started and the charge accumulation of the image sensor 221 is started. When the time corresponding to the shutter speed obtained in step # 135 or the shutter speed manually set by the photographer has elapsed, the running of the rear curtain of the shutter 213 is started and the charge accumulation of the image sensor 221 is ended.

When the exposure operation ends, an instruction to open the aperture is output to the lens CPU 111 (# 147). Subsequently, the movable mirror 201 is returned to the lowered position (149), and the image signal is read from the image sensor 221 (# 151). Image processing of the read image signal is performed by the image processing circuit 257 or the like (# 153), and the processed image data is recorded on the recording medium 277 (# 155). When the image recording is completed, the original routine is restored.

Next, the subroutine of the photographing operation B in step # 125 (FIG. 6) will be described using FIG. This shooting operation B is a subroutine executed when the release button 21 is fully pressed in the live view display state. When the shooting operation B subroutine is entered, the exposure amount is calculated based on the output of the AE circuit 255 (# 161).

Subsequently, as in steps # 141 and # 143, a narrowing instruction is given and a narrowing amount is designated (# 163, # 165). Then, similarly to step # 145, an exposure operation is performed (# 167), whereby image data of the subject image is acquired based on the output of the image sensor 221. Thereafter, as in steps # 147, # 151, # 153, and # 155, the aperture is instructed to be opened (# 169), the image signal is read (# 171), the image processing is performed (# 173), and the recording medium 277 is recorded. (# 175). When the image recording is completed, the original routine is restored.

Next, the subroutine for phase difference AF control in step # 121 (FIG. 6) and step # 133 (FIG. 7) will be described with reference to FIG. In this phase difference AF control, the focus deviation direction and the amount of focus deviation of the photographing optical system 101 are obtained by a known phase difference method using the two light beams around the photographing optical system 101. It is possible to perform AF with high accuracy similar to high accuracy AF in contrast AF.

When the phase difference AF control subroutine is entered, first, all point focus detection is performed (# 181). That is, the defocus direction and defocus amount are detected for all points detectable by the phase difference AF sensor 243 and the phase difference AF processing circuit 245. Subsequently, the closest point is selected from all the detected points (# 183). In general, since the main subject is most often the closest subject, such a selection is performed.

Next, based on the defocus amount at the selected closest point, it is determined whether or not the lens is within the focusing range (# 185). The criterion for determining whether or not the focus is within the focus range is based on whether or not the focus shift amount (defocus amount) is within a focus determination value based on the allowable circle of confusion. If the result of determination is within the in-focus range, the routine returns to the original routine. The permissible circle of confusion is set according to the imaging resolution of the image sensor 221, in other words, the cell size of the image sensor 221.

On the other hand, if the result of determination is not within the in-focus range, the driving direction for driving the imaging optical system 101 by the optical system driving mechanism 107 based on the focal shift direction and the focal shift amount of the selected focus detection point, and The drive amount is calculated (# 187). Then, the lens CPU 111 is instructed to perform lens drive control of the optical system drive mechanism 107 (# 189), and the lens drive amount and drive direction at that time are instructed (# 191).

When the body CPU 251 outputs a lens drive control instruction to the lens CPU 111, the body CPU 251 waits for a signal indicating completion of lens drive from the lens CPU 111 (# 193). When the lens driving is completed, focus detection is performed for the focus detection point selected in step # 183 (# 195). When focus detection ends, the process returns to step # 185, and the above steps are repeated until the focus range is entered.

Next, the contrast AF control subroutine in step # 52 (FIG. 4), step # 62 (FIG. 4), and step # 105 (FIG. 6) will be described with reference to FIGS. In this contrast AF control, the photographing optical system 101 is driven so that the contrast information in the contrast AF circuit 253 based on the output of the image sensor 221 is maximized. This contrast AF control can be used when the movable mirror 201 is in the retracted position (upward position) and phase difference AF control based on the output of the phase difference AF sensor 243 cannot be performed. In contrast AF control, high-speed contrast AF (first contrast AF) that performs AF control with high speed but low focusing accuracy, and second focusing with low speed but high focusing accuracy. There are two modes of high-precision contrast AF (second contrast AF) for performing AF control with accuracy.

When the subroutine for contrast AF control is entered, first contrast AF is started, and first, 1 is set in the register DC (# 201). This register DC is a register used to determine the driving direction of lens driving. Subsequently, the lens extension direction is set as the lens driving direction (# 203). Then, the first predetermined value is set as the lens driving amount (# 205). The first predetermined value corresponds to the focus lens feed amount LD1 in FIG. 16A, and is an amount related to the defocus amount ΔfLCD corresponding to the allowable circle of confusion diameter φLCD on the liquid crystal monitor surface in FIG. is there.

Next, contrast information is acquired from the contrast AF circuit 253 (# 207). In this case, when performing non-enlarged live view display, contrast information of image data corresponding to the entire shooting screen is acquired. Further, when the 1R switch is turned on during enlarged display, the contrast information acquired here is performed based on image data cut out for enlarged display. The same applies to the contrast information acquired in step # 215, which will be described later. Subsequently, lens drive control is instructed to the lens CPU 111 (# 209), and the lens drive amount and drive direction set in steps # 203 and # 205 are transmitted (# 211). When these signals are transmitted, the lens CPU 111 drives the photographing optical system 101 by the optical system driving mechanism 107. When the drive control based on the set drive direction and drive amount ends, the lens CPU 111 transmits a lens drive completion signal to the body CPU 251.

The body CPU 251 waits for reception of the lens drive completion signal (# 213), and when received, acquires the latest contrast information from the contrast AF circuit 253 (# 215). Subsequently, it is determined whether or not the contrast has improved compared to the previous time (# 217). If the current contrast is improved as a result of the determination, 1 is added to the register DC (# 219), the process returns to step # 209, and the above steps are repeated.

If the result of determination in step # 217 is that the contrast is lower than the previous time, it is determined whether or not the value of the register DC is 1 (# 221). As a result of the determination, if the register DC is 1, the lens drive direction is reversed from the previous time (# 223), the process returns to step # 209, and the above steps are repeated.

That is, in the first lens driving, since the driving direction is unknown, the lens is once driven in the extending direction. As a result of driving, if the contrast is improved, the driving direction is correct (approaching the in-focus position), while if the contrast is decreasing, the driving direction is reverse (away from the in-focus position). It reverses because it is. Therefore, if the register DC is 1, it is determined that the driving is the first time and the process proceeds to step # 223, and the driving direction is reversed. On the other hand, if the register DC is not 1, it is determined that the contrast has exceeded the peak position. Proceed to # 224.

If the result of determination in step # 221 is that the register DC is not 1, then it is determined whether or not enlarged display is in progress (# 224). If the result of determination is that enlarged display is in progress, the process jumps to step # 251 (FIG. 11). This is because it is determined that the contrast information has passed the peak position (# 221 → N), and if it is the enlarged live view display mode at this time (# 224 → Y), it is more than the first contrast AF. This is to immediately shift to the high-accuracy second contrast AF control. If the result of determination in step # 224 is that enlargement display is not in progress, the drive direction is set to the opposite direction to the previous time because the peak position of the contrast information has been exceeded (# 225). Then, a second predetermined value is set as the lens driving amount (# 227).

The second predetermined value as the lens driving amount corresponds to half of the focus lens extension amount LD1 in FIG. Since it exceeds the peak position of the contrast, it is assumed that there is a peak position between the previous time and the current time, and is half of the first predetermined value. Subsequently, the lens CPU 111 is instructed to perform lens drive control (# 229), and the lens drive amount and drive direction set in steps # 225 and # 227 are transmitted (# 231).

When the lens CPU 111 receives a lens drive control instruction or the like, the lens CPU 111 starts drive control for the optical system drive mechanism 107 and transmits a lens drive completion signal to the body CPU 251 when driven by a drive amount based on the second predetermined value. To do. The body CPU 251 waits for reception of the lens drive completion signal (# 233), and when receiving the completion signal, performs a first in-focus display (# 235). This is displayed on the display surface of the liquid crystal monitor 26 as the first in-focus display 311 as shown in FIG.

If the first focus display is not suitable for shooting and the subject image is confirmed on the liquid crystal monitor 26, the full-screen live view display mode (non-enlarged live view display mode, normal In the live view display mode, the in-focus state is inconspicuous, and the permissible focus range is set by the permissible circle of confusion based on the display resolution of the liquid crystal monitor 26, that is, the display dot size of the liquid crystal monitor 26. Is done. Therefore, the focusing accuracy is sufficient for observing the subject image on the liquid crystal monitor 26.

Subsequently, a lens position information request is instructed (# 241). The lens CPU 111 acquires lens position information from the optical system position detection mechanism 105 and transmits it to the body CPU 251. The body CPU 251 acquires the transmitted lens position information (# 243).

In step # 235, when the first in-focus display is made, the in-focus state becomes rough by contrast AF control, and the process returns to the original routine. After returning to the original routine, when the release button 21 is fully pressed and the photographing operation is started (step # 107 in FIG. 6), when a predetermined condition is satisfied, a highly accurate phase difference AF control is performed in step # 121. After performing the focusing control in step # 125, the photographing operation B in step # 125 is performed. The lens position information is acquired in steps # 241 and # 243 in order to determine whether or not the phase difference AF unnecessary condition is satisfied in step # 115.

If enlargement display is being performed in step # 224, contrast information is acquired for the second contrast AF (# 251 in FIG. 11).

Subsequently, the direction opposite to the previous time is set as the driving direction (# 253), and a third predetermined value is set as the driving amount (# 255). Here, the reverse drive direction is set because the contrast is lowered in step # 217, that is, it is determined that the peak position of the contrast information has passed. Because it is in the direction. The third predetermined value corresponds to the focus lens extension amount LD3 in FIG. 16B, and is related to the defocus amount Δfimg corresponding to the allowable circle of confusion diameter φimg on the imaging surface of the imaging element 211 in FIG. Amount.

Subsequently, lens drive control is instructed to the lens CPU 111 (# 257), and the lens drive amount and drive direction set in steps # 253 and # 255 are transmitted (# 259). The lens CPU 111 controls the optical system driving mechanism 107 to control driving of the photographing optical system 101. When the drive control is completed, a lens drive completion signal is transmitted to the body CPU 251. Therefore, the body CPU 251 is in a standby state until receiving this lens drive completion signal (# 261).

When the body CPU 251 receives the lens drive completion signal, it next acquires contrast information (# 263). Then, it is determined whether or not the contrast information has improved from the previous time (# 265). If the contrast is improved as a result of the determination, it is determined whether or not the 1R switch is on (# 285).

If the result of determination in step # 285 is that the 1R switch is off, processing returns to step # 257, and the above steps are repeated as long as the contrast improves. On the other hand, if the 1R switch is on, the process jumps to step # 279, and after performing the processes of steps # 279 and # 281, returns to the original routine. This defines the operation when the 1R switch is turned on when the second contrast AF is performed after the first focus display is performed. If the 1R switch is turned on, the second contrast AF is performed. The contrast AF is interrupted to return to the original routine. That is, when the 1R switch is turned on, the second contrast AF is interrupted in order to shift from step # 53 → Y to the preparation operation for the photographing operation.

If the result of determination in step # 265 is that the contrast has decreased, the driving direction is set opposite to the previous driving direction (# 267), and a fourth predetermined value is set as the driving amount (# 269). The fourth predetermined value as the lens drive amount corresponds to half of the focus lens extension amount LD3 in FIG. Since it exceeds the peak position of the contrast, it is assumed that there is a peak position between the previous time and the current time, and is half of the third predetermined value.

Subsequently, the lens CPU 111 is instructed to perform lens drive control (# 271), and the lens drive amount and drive direction set in steps # 267 and # 269 are transmitted (# 273). When the lens CPU 111 receives a lens drive control instruction or the like, the lens CPU 111 performs drive control by the optical system drive mechanism 107, and transmits a drive completion signal to the body CPU 251 when the drive control is completed. The body CPU 251 waits to receive this lens drive completion signal (# 275), and when receiving the drive completion signal, the body CPU 251 displays the second in-focus display (# 277).

In this display, as shown in FIG. 15B, a first in-focus display 311 and a second in-focus display 312 are displayed on the display surface of the liquid crystal monitor 26. The state in which the second in-focus display 312 is displayed is a highly accurate in-focus state equivalent to the permissible circle of confusion of the pixels of the image sensor 221, and is also in the same degree as the in-focus accuracy in the phase difference AF. is there. Once the second in-focus display 312 is performed, a lens position information request is instructed in the same manner as in step # 241 (# 279), and lens information is acquired in the same manner as in step # 243 (# 281). Return to the routine.

In this embodiment, when the contrast peak position is passed, the drive amount is halved and the drive is performed in the reverse direction (# 225, # 227, # 267, # 269). You may make it move to the peak position of contrast by interpolation calculations, such as a three-point interpolation method.

As described above, in the present embodiment, when the enlarged display is performed in the live view display mode (# 55 → # 75), the focus adjustment operation is performed by contrast AF control (# 62). For this reason, in the enlarged live view display mode, the focus is greatly deviated and the display image does not become a large-blurred situation. It is possible to know what the target is, and to provide a camera with an enlarged display function and a camera control method that are easy for the photographer to use. In the present embodiment, when the live view display mode is entered, contrast AF control is performed (# 52). Therefore, a focused subject image can be observed on the liquid crystal monitor 26 even in live view display, and the enlarged subject image can be quickly focused when shifting to the enlarged live view display mode. it can. Furthermore, in the present embodiment, in the full-screen live view display mode (normal live view display mode), when the photographing optical system 101 is guided within the first focus allowable range and the mode is shifted to the enlarged live view display mode, The second focusing tolerance range is narrower than the first focusing tolerance range. For this reason, the enlarged subject image is focused with high accuracy. Further, in the present embodiment, the focus allowable range in the full-screen live view display mode is the first focus allowable range, and is looser than the second focus allowable range in the enlarged live view display mode. ing. This is because the subject image is out of focus on the liquid crystal monitor 26 in the full-screen live view display mode as compared to the transition to the enlarged live view display mode. For this reason, there is an advantage that the contrast AF can be speeded up. Furthermore, in the present embodiment, the contrast AF control in the enlarged live view display mode generates contrast information using image data cut out for enlarged live view display, so that the accuracy of the display image is improved. The focus adjustment operation can be performed well.

Further, in the present embodiment, after contrast AF is performed in step # 52, step # 62, or step # 105, phase difference AF is performed in step # 121. In contrast AF in step # 52, step # 62, or step # 105, focus adjustment is performed at least at a high speed and with a coarse focusing accuracy, and then a highly accurate phase difference AF is performed in step # 121. Yes. Although the focusing accuracy of the contrast AF is rough (the first focusing accuracy), it is in the in-focus state, so it takes a long time to complete the high-precision focus adjustment from the in-focus state. Therefore, it is possible to adjust the focus with high accuracy with little time lag.

Further, in the enlarged live view display mode in the present embodiment, the second contrast AF mode is entered, and when the second in-focus display is made in the determination of step # 113, that is, in the high precision contrast AF. In the case of focusing, the phase difference AF in step # 121 is omitted. That is, in the present embodiment, the first focus adjustment mode in which focus adjustment is performed by a combination of high-speed contrast AF and phase difference AF, and the second focus adjustment mode in which focus adjustment is performed by high-precision contrast AF after high-speed contrast AF. However, by omitting the phase difference AF, the time lag can be shortened by the time required for the phase difference AF. Further, in the high-precision contrast AF, the focus adjustment can be performed with the same high accuracy as the phase difference AF, and sufficient focusing accuracy can be ensured.

Further, in step # 115 in the present embodiment, an unnecessary condition for phase difference AF is determined, and when this unnecessary condition is met, the phase difference AF in step # 121 is omitted. For this reason, the time lag can be shortened by the time required for the phase difference AF, and high-precision focus adjustment can be performed. In the present embodiment, three conditions are used as unnecessary conditions for phase difference AF. However, the present invention is not limited to this, and other requirements may be added, or any of the requirements may be omitted. Also good. In any case, the phase difference AF can be omitted as long as sufficient focusing accuracy is obtained without performing the phase difference AF with high accuracy.

Further, in step # 117 in this embodiment, it is determined whether or not AF lock is performed. If AF lock is performed, the phase difference AF in step # 121 is omitted. For this reason, the time lag can be shortened by the time required for the phase difference AF. In particular, when the AF lock is performed, the photographer has already determined the in-focus position, and often wants to shoot quickly, and at least the first in-focus display is provided. Temporary focusing accuracy can be ensured. In the present embodiment, the phase difference AF is omitted when the AF lock button 28 is operated. However, not only the AF lock button 28 but also the phase difference AF is operated when another operation member is operated. May be omitted.

Next, the focusing accuracy of contrast AF in the present embodiment will be described with reference to FIGS. As shown in FIG. 17A, the pixels on the imaging surface of the imaging element 221 are 3648 pixels in the horizontal direction and 2738 pixels in the vertical direction. On the other hand, if the liquid crystal monitor surface of the liquid crystal monitor 26 is composed of 640 pixels in the horizontal direction and 320 pixels in the vertical direction as shown in FIG. Is about 1/7, and even if the LPF coefficient is taken into consideration, it is about 1/4, so that the allowable confusion circle diameter φLCD of the liquid crystal monitor 26 is
φLCD = (3648/640) * φimg / α
≒ 4 * φimg
It becomes.

The allowable defocus amount ΔfLCD for the liquid crystal monitor corresponding to the allowable confusion circle diameter φLCD of the liquid crystal monitor 26 is
ΔfLCD = φLCD / F
F: Lens aperture value (FNo.)
F = D / f (D: aperture, f: focal length)

Accordingly, the focusing accuracy in the first focus display (# 235) is such that the driving amount is the first predetermined value, and as this first predetermined value, as shown in FIG. By adopting β * ΔfLCD, it is possible to obtain the focusing accuracy of the permissible circle of confusion diameter φLCD of the liquid crystal monitor 26. Here, β≈5 to 15 (β is an empirical value).

On the other hand, as shown in FIG. 17A, the imaging surface (light receiving surface) of the imaging element 221 is composed of 3648 pixels in the horizontal direction and 2838 pixels in the vertical direction. The allowable confusion circle diameter φimg of the image sensor 221 is
φimg = α * X
Where α: LPF coefficient (= 1.5-2)
X: Cell size. Since the LPF coefficient is a coefficient due to the influence of the infrared cut filter / low-pass filter 217, the allowable confusion circle diameter φimg of the image sensor 221 is obtained by multiplying the pixel size of the image sensor by a coefficient considering the low-pass filter. Is obtained.

Then, the allowable defocus amount Δfimg for imaging corresponding to the allowable confusion circle diameter φimg of the image sensor 221 is
Δfimg = φimg / F
F: Lens aperture value (FNo.)
F = D / f (D: aperture, f: focal length)

Therefore, the focusing accuracy in the second focus display (# 277) is such that the driving amount is the second predetermined value, and γ * Δfimg is adopted as the second predetermined value as shown in FIG. For example, it is possible to obtain a focusing accuracy of about the allowable confusion circle diameter φimg of the image sensor 221. Here, γ≈3 (γ is an empirical value). Note that the number of pixels described individually is an example, and an allowable circle of confusion, a defocus amount, and a drive amount may be determined according to the design value of the photographing apparatus here. Note that the focus allowable range in the phase difference AF is also determined based on Δfimg.

Next, the operation of the interchangeable lens 100 in the lens CPU 111 will be described with reference to FIG. First, it is determined whether or not a lens information request instruction has been issued from the body CPU 251 (# 301). If the request is instructed as a result of the determination, lens information is transmitted (# 311). The lens information here is information unique to the lens such as an open aperture value, a minimum aperture value, lens color balance information, aberration information, information for AF, and the like. This is information stored in a rewritable memory.

If the result of determination in step # 301 is not a lens information request instruction, it is determined whether or not lens position information is requested (# 303). If it is determined that the position information is requested, the lens position information is transmitted to the body CPU 251 (# 313). Since the lens position information is detected by the optical system position detection mechanism 105, this information is transmitted.

If the result of determination in step # 303 is not a position information request instruction, it is determined whether or not it is a narrowing instruction (# 305). If the result of the determination is a narrowing instruction, the narrowing amount transmitted from the body CPU 251 is subsequently received (# 315). When the aperture amount is received, the aperture drive mechanism 109 controls the aperture drive of the aperture 103 (# 317).

If the result of determination in step # 305 is not a narrowing-down instruction, it is determined whether or not it is an opening instruction (# 307). If the result of the determination is an aperture opening instruction, the aperture opening drive control of the aperture 103 performed by the aperture driving mechanism 109 is controlled (# 317).

If the result of determination in step # 307 is that there is no aperture opening instruction, it is determined whether or not it is a lens drive control instruction (# 309). If the result of the determination is a lens drive control instruction, the lens drive amount and drive direction transmitted subsequently are received (# 321). When the lens driving amount and the driving direction are received, the lens CPU 111 controls the optical system driving mechanism 107 to control the photographing optical system 101 (# 323). When a predetermined driving amount is driven, a lens driving completion signal is transmitted to the body CPU 251 (# 325).

In the embodiment of the present invention, an imaging element 221 that receives a subject luminous flux incident through the imaging optical system 101 on an imaging surface, photoelectrically converts the subject image formed on the imaging surface, and outputs subject image data; Using the subject image data acquired by the image sensor 221, a full-screen live view display mode for displaying almost the entire area of the shooting range and an enlarged live view display for displaying a specific area of the shooting range in an enlarged manner can be selected. Contrast information in the latest object image data output from the liquid crystal monitor 26 performing the live view display operation (# 15, # 55) and the image sensor 221 is obtained, and focusing of the photographing lens is permitted based on the contrast information. Contrast AF means (contrast AF circuit 253, optical system drive mechanism 107, etc.) that guides within the range is provided, and a full-screen live view is provided. In conjunction with the switching from the display mode to the enlarged live view display mode, running the focusing operation by the contrast AF means (# 62).

As described above, in this embodiment, when the mode is shifted to the enlarged display mode (# 55), the contrast AF control is performed (# 62). For this reason, in the enlarged live view display mode, the focus is greatly deviated and the display image does not become a large-blurred situation. It is possible to provide a camera with an enlarged display function that is easy to use for a photographer by knowing what is being targeted.

In the present embodiment, it is determined whether the first and second focus indications (# 235, # 277) are made as to whether or not the first and second focus states have been reached. However, even if the in-focus display is not made, it is of course possible to determine whether or not the first and second in-focus states have been reached by a method such as setting a flag and determining this. In the present embodiment, when the live view display mode is entered, the automatic focus adjustment is performed by the contrast AF method (# 52), but here, the automatic focus adjustment is not performed and the enlarged live view display mode is entered. At this time, automatic focus adjustment by the contrast AF method may be performed.

Furthermore, in the present embodiment, the subject luminous flux is switched between the finder optical system and the image pickup device by moving the movable mirror 201 up and down. May be. Further, the focusing accuracy by the phase difference AF is approximately the same as the accuracy at the time of the second focusing display by the high-precision contrast AF. However, the focusing accuracy is not limited to this, and any of the focusing accuracy is higher. Also good. However, the focusing accuracy by the phase difference AF is higher than the system for the first focusing display in the high-speed contrast AF. Furthermore, in the phase difference AF control subroutine, the closest point is selected from among the focus detection points (# 183). However, the present invention is not limited to this, and an intermediate value of a plurality of focus detection results may be selected. In addition, a plurality of focus detection results may be appropriately processed by an evaluation calculation.

In the present embodiment, an example in which a single-lens reflex camera is applied as a digital camera has been described. However, a so-called compact camera may be used as the camera, and a built-in mobile phone, PDA (Personal Digital Assistant), or the like. It may be a type of camera. In any case, the present invention can be applied to any electronic imaging device such as a camera that can perform live view display and adjust the focus by contrast AF control.

It is the external appearance perspective view which looked at the digital single-lens reflex camera in one Embodiment of this invention from the back. 1 is a block diagram illustrating an overall configuration of a digital single-lens reflex camera according to an embodiment to which the present invention is applied. It is a flowchart which shows the operation | movement of the power-on reset in the camera main body side in one Embodiment of this invention. It is a flowchart which shows the operation | movement of the live view display in one Embodiment of this invention. It is a flowchart which shows the operation | movement of the live view display in one Embodiment of this invention. It is a flowchart which shows the operation | movement of the live view display in one Embodiment of this invention. It is a flowchart which shows the operation | movement of the imaging | photography operation | movement A in one Embodiment of this invention. It is a flowchart which shows the operation | movement of the imaging operation B in one Embodiment of this invention. It is a flowchart which shows the operation | movement of phase difference AF control in one Embodiment of this invention. It is a flowchart which shows the operation | movement of contrast AF control in one Embodiment of this invention. It is a flowchart which shows the operation | movement of contrast AF control in one Embodiment of this invention. It is a flowchart which shows the operation | movement of the power-on reset in the interchangeable lens side in one Embodiment of this invention. It is a figure which shows the display state in the liquid crystal monitor in the enlarged display mode in one Embodiment of this invention, (A) shows a full-screen display state, (B) shows an enlarged display state, (C) is an enlarged range. (D) shows the enlarged part in (B), (E) is a figure which shows the enlarged part in (C). It is a figure which shows the menu display screen of AF mode setting in one Embodiment of this invention. It is a figure which shows the focus completion display in one Embodiment of this invention, (A) shows a 1st focus display, (B) is a figure which shows a 2nd focus display. It is a figure which shows the contrast information and drive relationship of a focus lens in one Embodiment of this invention, (A) is a case of high-speed contrast AF, (B) is a figure which shows the case of high-precision contrast AF. It is a figure explaining the permissible circle of confusion of an image sensor and a liquid crystal monitor in one embodiment of the present invention, (A) shows the permissible circle of confusion of an image sensor, and (B) shows the permissible circle of confusion of a liquid crystal monitor. Show. It is a figure which shows the relationship between the allowable confusion circle diameter and defocus amount in one Embodiment of this invention.

Explanation of symbols

21 ... Release button, 22 ... Shooting mode dial, 24 ... Information setting dial, 26 ... LCD monitor, 27 ... Continuous / single-shot button, 28 ... AF lock button, 30 ... Cross button, 30U ... Cross button for up, 30D ... Cross button for down, 30R ... Cross button for right, 30L ... Cross button for left, 31 ... OK button, 33 ..Live view display button 34... Enlarge button 37. Menu button 38. Play button 40. Media loading lid 50. Strobe 100. Interchangeable lens 101 ...... Optical optical system 103 ... Aperture 105 ... Optical system position detection mechanism 107 ... Optical system drive mechanism 109 ... Aperture drive mechanism 111 ... Lens CPU 200 ...・ Camera body, 201 ... movable mirror, 203 ... sub 205, focusing screen, 207 ... pentaprism, 211 ... photometric sensor, 213 ... focal plane shutter, 215 ... dust filter, 216 ... piezoelectric element, 217 ... red Outer cut filter / low-pass filter, 221... Image sensor, 223... Image sensor drive circuit, 225... Pre-processing circuit, 227. Shift mechanism drive circuit, 233 ... Shift mechanism, 235 ... Dust-proof filter drive circuit, 237 ... Movable mirror drive mechanism, 241 ... Photometric processing circuit, 243 ... Phase difference AF sensor, 245 ... Phase difference AF processing circuit, 250... ASIC, 251... Sequence controller (body CPU), 252. Bus, 253 ... Contrast AF circuit, 255 ... AE circuit, 257 ... Image processing circuit, 259 ... Compression / decompression circuit, 261 ... Video signal output circuit, 263 ... Liquid crystal monitor drive circuit 265 ... SDRAM detection circuit, 267 ... SDRAM, 271 ... I / O circuit, 273 ... communication circuit, 275 ... recording medium control circuit, 277 ... recording medium, 279 ... Flash memory control circuit, 281 ... flash memory, 283 ... switch detection circuit, 285 ... various switches, 300 ... communication contact, 311 ... first focus display, 312 ... second Focus display

Claims (1)

Imaging means for receiving a subject luminous flux incident through a photographing lens on an imaging surface, photoelectrically converting a subject image formed on the imaging surface and outputting subject image data;
Using the subject image data acquired by the imaging means, it is possible to perform full-screen live view display that displays almost the entire area of the shooting screen and enlarged live view display that displays a specific area of the shooting screen in an enlarged manner. A display means for switching the operation member according to the operation of the operation member;
Contrast information in the latest subject image data output from the imaging means is obtained, and based on this contrast information, the photographing lens is within the first focus allowable range or narrower than the first focus allowable range. Contrast AF means for executing contrast AF control leading to the second focus tolerance range;
It has
The contrast AF means guides the photographing lens within the first focus allowable range in conjunction with the start of the full-screen live view display, and the operation member is operated during the full-screen live view display to In conjunction with switching to the enlarged live view display, the photographic lens is guided to the second focus allowable range, and the operation member is operated again during the enlarged live view display to display the full screen live view display. A camera with an enlarged display function, wherein the contrast AF control is not performed even when switched to.