JP2012085261A - Imaging apparatus, finder, and display method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform display without noise and time lag even in such a dark environment in which a subject is not seen through an OVF.SOLUTION: A contour is detected from each subject in a through image captured with improved sensitivity. On the basis of the detected contour, a contour image is generated and the generated contour image is displayed on a liquid crystal plate 110. In the contour image, the detected contour portion, for example, is composed of a broken line; the other portion being transparent. Thus, a video in the OVF and the contour image displayed on an EVF are superimposed on each other and guided to a finder eyepiece part 38.

Description

  The present invention relates to an imaging apparatus, a finder, and a display method thereof, and more particularly to a technique that uses an optical viewfinder and an electronic viewfinder together.

  There are two types of viewfinders that indicate the shooting range of the camera: an optical viewfinder (hereinafter referred to as OVF) and an electronic viewfinder (hereinafter referred to as EVF). The OVF shows incident subject light to the photographer through an optical system. The EVF converts the incident subject light into an image signal by an image sensor, and then displays an image based on the image signal on a liquid crystal monitor or the like. To show the photographer.

  Japanese Patent Application Laid-Open No. 2004-228561 discloses a technique that enables EVF character information to be clearly seen in a hybrid finder that combines an OVF image and an EVF image with a half mirror and guides the image to an eyepiece.

  Here, the characteristics of both finders will be described. 12A and 12B are diagrams illustrating an example of a finder image. FIG. 12A illustrates an OVF image in a fireworks shooting scene, and FIG. 12B illustrates an EVF image in a similar scene.

  Since the OVF is for visually recognizing the subject light that has passed through the optical system, the video image has no time lag. However, as shown in FIG. 12 (a), in a dark environment such as a shooting scene of fireworks, the OVF image can recognize the fireworks 301 and the lighted windows 303b and 303c, but other subjects. Is unrecognizable because it is dark.

  On the other hand, EVF displays images taken repeatedly at a predetermined cycle in real time. As shown in FIG. 12B, in the EVF video, by increasing the shooting sensitivity, in addition to the fireworks 301 and the lighted windows 303b and 303c, the building 302 and the lighted non-lighted window 303a. You can also project the subject.

Japanese Patent Laid-Open No. 04-30677

  However, since the shooting sensitivity is increased, the image of EVF is greatly influenced by noise. Also, with EVF, shooting of a moving subject is not suitable because of a display time lag. In the example of FIG. 12B, since there is movement in the fireworks, it is difficult to take a picture at the timing when the fireworks are fully opened while viewing the EVF image.

  The present invention has been made in view of such circumstances. Even in a dark environment where an object cannot be seen with an OVF, a display without noise and time lag is performed, so that an appropriate angle of view and an appropriate timing can be obtained. An object of the present invention is to provide an imaging apparatus, a finder, and a display method thereof capable of performing the above-described photographing.

  To achieve the above object, a viewfinder according to the present invention superimposes an optical viewfinder, an electronic viewfinder, a subject image incident on the optical viewfinder, and a display image displayed by the electronic viewfinder. A superimposing unit; an imaging unit that converts a subject image received through an imaging lens into an image signal; a contour extracting unit that extracts a contour of the subject image from the image signal; and a contour based on the extracted contour An outline image generation unit that generates an image, and a display unit that displays the outline image on the electronic viewfinder are provided.

  According to the present invention, an optical system that superimposes a subject image incident on an optical viewfinder and a display image displayed by an electronic viewfinder, and a subject image received through an imaging lens are converted into an image signal. The contour of the subject image is extracted from the signal, the contour image is generated based on the extracted contour, and the contour image is displayed on the electronic viewfinder. Therefore, it is a dark environment where the subject cannot be seen with OVF. However, display without noise and time lag can be performed.

  It is preferable to include a metering unit that measures a subject luminance based on the image signal, and a control unit that causes the contour extracting unit to extract a contour when the measured subject luminance is a predetermined value or less.

  Thus, the contour can be displayed only when the subject brightness is low.

  You may provide the backlight detection means which detects the backlight with respect to a to-be-photographed object based on the said image signal, and the control means which makes the said contour extraction means extract an outline when a backlight is detected.

  Thus, the contour can be displayed only when the subject brightness is low.

  The optical viewfinder is a single-lens reflex type finder, and the superimposing means enters the optical viewfinder by placing the electronic viewfinder adjacent to the focusing screen of the optical viewfinder. The captured subject image may be superimposed on the display image displayed by the electronic viewfinder.

  The present invention can be applied to a single-lens reflex type finder, and a display image can be appropriately superimposed by disposing an electronic view finder adjacent to a focusing screen.

  The optical axis of the optical viewfinder is different from the optical axis of the imaging lens, and the contour image generating means matches the contour of the extracted subject image with the subject image incident on the optical viewfinder. The contour image may be generated.

  Thereby, even when there is a parallax in OVF and EVF, an outline can be appropriately displayed.

  The superimposing means transmits the subject image incident on the optical viewfinder and reflects the display image displayed by the electronic viewfinder and the subject image incident on the optical viewfinder and the electronic viewfinder. It is preferable to superimpose the display image displayed by.

  Accordingly, the OVF video and the EVF video can be appropriately superimposed.

  In order to achieve the above object, an image pickup apparatus according to the present invention includes the above-described finder, a release button for a photographer to input a shooting instruction, and an image signal from the imaging unit when the shooting instruction is input by the release button. And a photographing means for obtaining a photographed image based on the image signal and an image recording means for recording the obtained photographed image.

  According to the present invention, even in a dark environment where the subject cannot be seen with OVF, it is possible to shoot at an appropriate angle of view and at an appropriate timing by performing display without noise and time lag.

  In order to achieve the above object, a finder display method according to the present invention includes an optical viewfinder, an electronic viewfinder, a subject image incident on the optical viewfinder, and a display image displayed by the electronic viewfinder. In a finder display method comprising: a superimposing unit that superimposes an image of the subject image; an imaging step of converting a subject image received through an imaging lens into an image signal; and a contour extraction step of extracting the contour of the subject image from the image signal And a contour image generating step for generating a contour image based on the extracted contour, and a display step for displaying the contour image on the electronic viewfinder.

  According to the present invention, even in a dark environment where the subject cannot be seen with OVF, it is possible to perform display without noise and without time lag. In addition, this display enables photographing with an appropriate angle of view and an appropriate timing.

Front perspective view showing the external configuration of a digital single-lens reflex camera Rear perspective view showing external configuration of digital single-lens reflex camera Side cross-sectional view of a digital SLR camera Block diagram showing the electrical configuration of a digital single-lens reflex camera The flowchart which shows the display process of the finder based on 1st Embodiment The figure which shows the outline image produced | generated from the through image Image showing viewfinder eyepiece The flowchart which shows the display process of the finder which concerns on 2nd Embodiment Front perspective view showing external configuration of digital camera Rear perspective view showing external configuration of digital camera Top view of digital camera Figure showing an example of a viewfinder image

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

[First Embodiment]
[Camera configuration]
1 and 2 are a front perspective view and a rear perspective view, respectively, showing the external configuration of the digital single-lens reflex camera 10 according to the present embodiment.

  As shown in the figure, the digital single-lens reflex camera 10 of the present embodiment includes a camera body 12 and a photographic lens 14 that is detachably attached to the camera body 12.

  The photographic lens 14 is attached to the camera body 12 by attaching a lens side mount provided at the base end to a camera side mount provided in front of the camera body 12.

  In addition to this camera side mount, an AF auxiliary light lamp 16, a depth of field confirmation button 18, a sync terminal 20, a grip 22 and the like are provided on the front surface of the camera body 12, and a shutter button 24, A power lever 26, a subcommand dial 28, a top display panel 30, a mode dial 32, an accessory shoe 34, a strobe 36, and the like are provided.

  Further, on the back of the camera body 12, a viewfinder eyepiece 38, a diopter adjustment lever 40, a liquid crystal monitor 42, a slot cover 44, a rear display panel 46, a cross button 48, a menu button 50, a back button 52, and a function button 54. A main command dial 56, a playback button 58 and the like are provided, and a tilt adjustment knob 60 and the like are provided on the right side surface.

  Confirmation of the subject image is performed through the finder eyepiece 38, and the photographer can observe the subject image projected on the focusing screen by looking through the finder eyepiece 38. The shutter button 24 is a two-stage type consisting of full-pressing and half-pressing. When the shutter button 24 is half-pressed, AE and AF operations are performed. In the actual shooting, an image obtained by shooting is recorded on a memory card (240 in FIG. 4). The image recorded on the memory card is reproduced and displayed on the liquid crystal monitor 42 by setting the camera mode to the reproduction mode (in this embodiment, the reproduction button 58 is pressed).

  FIG. 3 is a side sectional view of the digital single-lens reflex camera 10. As shown in the figure, the digital single-lens reflex camera 10 includes a CCD 100, a liquid crystal plate 110, a quick return mirror 120, a focusing screen 122, an eyepiece 126, a pentaprism 124, a field frame 128, and the like.

  A quick return mirror 120 is inclined at 45 ° between the taking lens 14 and the CCD 100. The subject light transmitted through the photographic lens 14 is reflected upward by the quick return mirror 120.

  Above the quick return mirror 120, a focusing screen 122, a liquid crystal plate 110, a field frame 128, and a pentaprism 124 are provided.

  The subject light reflected by the quick return mirror 120 forms a subject image on the mat surface of the focusing screen 122 as a left-right reverse image. The liquid crystal plate 110 is a transmissive display means, and the subject image formed on the mat surface of the focusing screen 122 is transmitted through the liquid crystal plate 110 and is viewed by the field frame 128 through the viewfinder field (viewable field from the viewfinder eyepiece 38). After the range) is regulated, the image is reversed left and right by the pentaprism 124 to be an erect image, and is magnified and observed by the eyepiece 126 from the viewfinder eyepiece 38.

  The quick return mirror 120 is a half mirror and transmits part of the subject light. Part of the subject light transmitted through the quick return mirror 120 is incident on the light receiving surface of the CCD 100.

  The subject image formed on the light receiving surface of the CCD 100 is converted into a signal charge of an amount corresponding to the amount of incident light by each sensor. An image signal is generated from the signal charges read from the CCD 100 by various signal processing circuits.

  The liquid crystal plate 110 can display various images. For example, an image based on the image signal output from the CCD 100 can be displayed. The image displayed on the liquid crystal plate 110 is guided to the viewfinder eyepiece 38 through the pentaprism 124 and the eyepiece 126 together with the subject image formed on the mat surface of the focusing screen 122 so that the photographer can visually recognize the image. Can do.

As described above, the digital single-lens reflex camera 10 includes a single-lens reflex type OVF that guides an image, which is subject light that is incident from the photographing lens 14 and reflected by the quick return mirror 120, to the viewfinder eyepiece 38, and a liquid crystal display. An EVF for guiding the image displayed on the plate 110 to the viewfinder eyepiece 38 is provided. Then, by arranging both on the same optical path, the video is superimposed and guided to the viewfinder eyepiece 38. Therefore, the two viewfinders function as a hybrid viewfinder that allows the photographer to observe the superimposed video.

  Further, the quick return mirror 120 is configured to be able to repel in the direction of the arrow in FIG. The quick return mirror 120 is repelled by the photographer pressing the shutter button 24 and retracted from the photographing optical path. As a result, the subject light incident from the photographing lens 14 is incident on the light receiving surface of the CCD 100 and the actual photographing is performed. The quick return mirror 120 returns to the original position after the photographing is completed.

[Electrical configuration of the camera]
FIG. 4 is a block diagram showing an electrical configuration of the digital single-lens reflex camera 10.

  As shown in the figure, the digital single lens reflex camera 10 includes a liquid crystal monitor 42, a CCD 100, a liquid crystal plate 110, a CPU 210, an operation unit (shutter button, power button, menu button, OK button, cancel button, cross button, playback button, etc. Various operation buttons) 212, ROM 216, EEPROM 218, memory (SDRAM) 220, VRAM 222, timing generator (TG) 226, analog signal processing circuit 228, A / D converter 230, image input controller 232, image signal processing circuit 234, A compression / decompression processing circuit 236, a media controller 238, a memory card 240, a display control circuit 242, and the like are included.

  The CPU 210 functions as a control unit that comprehensively controls the operation of the entire digital single lens reflex camera 10 including the photographing lens 14 attached to the camera body 12, and is based on an input from the operation unit 212 according to a predetermined control program. Control each part of the camera.

  The ROM 216 stores a control program executed by the CPU 210 and various data necessary for the control. The EEPROM 218 stores various setting information related to the operation of the digital single lens reflex camera such as user setting information. .

  The memory (SDRAM) 220 is used as a calculation work area for the CPU 210 and is used as a temporary storage area for image data, and the VRAM 222 is used as a storage area dedicated to display image data.

  The CCD 100 is arranged at the rear stage of the photographing lens 14 and receives subject light transmitted through the photographing lens 14. The CCD 100 includes a light receiving surface on which a large number of light receiving elements are arranged in a matrix. The subject light that has passed through the photographing lens 14 is imaged on the light receiving surface of the CCD 100 and converted into an electrical signal by each light receiving element.

  The CCD 100 outputs charges accumulated in each pixel as a serial image signal line by line in synchronization with a vertical transfer clock and a horizontal transfer clock supplied from a timing generator (TG) 226. The CPU 210 controls the drive of the CCD 100 by controlling the TG 226.

  Note that the charge accumulation time (exposure time) of each pixel is determined by an electronic shutter drive signal given from the TG 226. The CPU 210 instructs the TG 226 about the charge accumulation time.

  The output of the image signal is started when the digital single-lens reflex camera 10 is set to the shooting mode. That is, when the digital single-lens reflex camera 10 is set to the photographing mode, output of an image signal is started in order to display a through image on the liquid crystal monitor 42. The output of the image signal for the through image is temporarily stopped when the instruction for the main photographing is given, and is started again when the main photographing is finished.

  The image signal output from the CCD 100 is an analog signal, and this analog image signal is taken into the analog signal processing circuit 228.

  The analog signal processing circuit 228 includes a correlated double sampling circuit (CDS) and an automatic gain control circuit (AGC). The CDS removes noise contained in the image signal, and the AGC amplifies the noise-removed image signal with a predetermined gain. The analog image signal that has undergone the required signal processing by the analog signal processing circuit 228 is taken into the A / D converter 230.

  The A / D converter 230 converts the captured analog image signal into a digital image signal having a gradation width of a predetermined bit. This image signal is so-called RAW data, and has a gradation value indicating the density of R, G, and B for each pixel.

  The image input controller 232 has a built-in line buffer with a predetermined capacity, and stores the image signal for one frame output from the A / D converter 230. The image signal for one frame accumulated in the image input controller 232 is stored in the memory (SDRAM) 220 via the bus 214.

  In addition to the CPU 210, memory 220, and image input controller 232, the image signal processing circuit 234, compression / expansion processing circuit 236, display control circuit 242, media controller 238, and the like are connected to the bus 214. It is possible to send and receive information to and from each other.

  The image signal for one frame stored in the memory 220 is taken into the image signal processing circuit 234 in dot order (pixel order).

  The image signal processing circuit 234 performs predetermined signal processing on the image signals of R, G, and B colors that are captured in a dot-sequential manner, and generates an image signal (Y / C) composed of a luminance signal Y and color difference signals Cr, Cb. Signal).

  In addition, a contour detection circuit 235 is connected to the image signal processing circuit 234. The contour detection circuit 235 detects the contour of the subject from the image signal stored in the memory 220. Contour detection is performed using a first-order integral Sobel filter, a pre-witt filter, or a second-order integral Laplacian filter. Alternatively, RGB single color outlines may be detected and then combined.

  The compression / decompression processing circuit 236 performs predetermined compression processing on the image data generated by the image signal processing circuit 234 in accordance with a command from the CPU 210 to generate compressed image data. The compressed image data is subjected to a predetermined expansion process to generate uncompressed image data.

  The media controller 238 records image data obtained by shooting on the memory card 240 in accordance with a command from the CPU 210, and reads a recorded image from the memory card 240.

  The display control circuit 242 controls display on the liquid crystal plate 110 and the liquid crystal monitor 42 in accordance with a command from the CPU 210.

  A general image recording procedure of the digital single-lens reflex camera 10 configured as described above will be described.

  When a shooting instruction is input to the CPU 210 by fully pressing the shutter button 24, the CPU 210 performs necessary shooting control, and the CCD 100 captures an image for one frame.

  R, G, and B image signals for one frame imaged by the CCD 100 are stored in the memory 220 via the analog signal processing circuit 228, the A / D converter 230, and the image input controller 232. Applied to the processing circuit 234. The image signal processing circuit 234 performs necessary signal processing on the input image signal to generate image data composed of luminance data and color difference data.

  The generated image data is temporarily stored in the memory 220, then added to the compression / decompression processing circuit 236, subjected to predetermined compression processing, and then stored again in the memory 220.

  The CPU 210 generates an image file having a predetermined format in which predetermined shooting information is added to the compressed image data stored in the memory 220, and records the image file on the memory card 240 via the media controller 238.

  The image data recorded on the memory card 240 in this way is read from the memory card 240 in response to a reproduction command and reproduced and displayed on the liquid crystal monitor 42. That is, when a playback instruction is input to the CPU 310 by the playback button, the CPU 210 reads the compressed image data of the image file recorded last on the memory card 240 via the media controller 238. The read compressed image data is added to the compression / decompression processing circuit 236, converted into non-compressed image data, and stored in the VRAM 222. The image file stored in the VRAM 222 is added to the display control circuit 242, converted into a monitor display signal format, and output to the liquid crystal monitor 42. As a result, the image recorded on the memory card 240 is reproduced and displayed on the liquid crystal monitor 42.

  When an image frame advance is instructed by a cross button or the like, the next image is read from the memory card 240 and reproduced and displayed on the liquid crystal monitor 42. When a frame return is instructed, the previous image is read from the memory card 240 and reproduced and displayed on the liquid crystal monitor 42.

[Finder display processing]
FIG. 5 is a flowchart showing a finder display process according to the first embodiment.

  First, the subject brightness is calculated (step S1). That is, R, G, and B image signals stored in the memory 220 are captured, the shooting area (one screen) is divided into a plurality of areas, and the integrated value of the image signals for each R, G, and B is divided for each divided area. calculate. The subject luminance is calculated from the calculated integrated value information for each of R, G, and B in each divided region.

  Based on the calculated subject brightness, it is determined whether or not the photographer can recognize the subject from the OVF video (step S2). For example, if the subject brightness calculated in step S1 is greater than a predetermined value, it is determined that the subject can be recognized because the environment is bright. On the contrary, if it does not satisfy the predetermined value, it may be determined that the subject cannot be recognized because of the dark environment.

  If it is determined that the subject can be recognized from the OVF image, the funda display is performed using only the OVF (step S4).

  Conversely, if it is determined that the subject cannot be recognized in the OVF video, the OVF and the EVF are superimposed and displayed (step S5).

  In this case, first, the shooting sensitivity is increased and a through image is shot. The imaging sensitivity may be increased by an AGC amplification factor. For example, in the case of a shooting scene as shown in FIG. 12, a through image as shown in FIG. 12B can be acquired.

  From the acquired through image, the contour detection circuit 235 detects the contour from each subject in the image. As described above, a Sobel filter or the like may be used for contour detection. In the example of the through image shown in FIG. 12B, the outlines of the fireworks 301, the building 302, and the windows 303 are detected.

  A contour image is generated based on the detected contour. FIG. 6 is a diagram showing a contour image generated from the through image shown in FIG. In the contour image, for example, the detected contour portion is a broken line, and the portion other than the contour is transparent. In FIG. 6, the contour portion is represented as a black broken line for convenience, but is actually a white broken line.

  Next, the generated contour image is displayed on the liquid crystal plate 110. As a result, the OVF image shown in FIG. 12A and the contour image displayed on the EVF are superimposed and guided to the viewfinder eyepiece 38.

  FIG. 7 is a diagram showing an image observed from the viewfinder eyepiece 38 at this time. As shown in the figure, the OVF image can be seen as it is in the fireworks 301 that is a bright subject and the windows 303b and 303c that are lit with light. Furthermore, the EV 302 contour image enables the building 302 and the window 303a, which are dark subjects that cannot be visually recognized by the OVF, to be visually recognized by white contour lines.

  Here, a white broken line is used as the contour line so that it can be easily recognized even in a dark OVF image, but the present invention is not limited to this. For example, a red or yellow solid line may be used. In addition, the outline of the subject that cannot be visually recognized by the OVF may be displayed as appropriate, for example, by blinking the outline image.

  The photographer can adjust the angle of view while viewing this superimposed image and perform the actual photographing (step S6). In the actual shooting, an image as shown in FIG. 12B may be shot by increasing the shooting sensitivity, or an image obtained by irradiating a strobe light on a subject that cannot be seen with OVF by causing the flash 36 to emit light. You may shoot.

  In this way, when the subject brightness is dark and the subject cannot be recognized by the OVF, the EVF contour image is superimposed on the OVF image, so that the angle of view can be appropriately adjusted by the finder image without noise. Since there is no time lag, the main shooting can be performed without missing a photo opportunity.

  In this embodiment, the contours of all the subjects detected from the through image are displayed. However, since the EVF display has a time lag, it is not necessary to display the contours of the subject that changes rapidly. For example, in the contour image shown in FIG. 6, since the fireworks 301 change quickly, the contour line may not match the OVF image. Therefore, the contour may be extracted only from a subject that is determined to be slow or unchanged due to the through image.

  Further, it is not necessary to extract the outline of a subject that can be visually recognized with OVF. The brightness may be calculated for each subject, and the contour may be extracted only for the subject that cannot be visually recognized by the OVF. In this way, by extracting only the necessary contour and generating the contour image, the time for the contour image generation processing can be shortened.

  In the present embodiment, the presence / absence of superimposed display is automatically determined by calculating the subject luminance, but the photographer may be configured to be selectable. For example, a photographing mode for performing superimposed display may be provided, and the photographer may actually check the OVF video, and may be set to the superimposed display mode when the subject cannot be confirmed by OVF. Furthermore, the superimposed display may be performed only when the shutter button 24 is half-pressed.

  Further, in this embodiment, the OVF optical system and the EVF optical system are superimposed by disposing the liquid crystal plate 110 at a position adjacent to the single-lens reflex type OVF focusing screen. It is not limited to this. For example, you may superimpose through a half mirror like patent document 1. FIG.

[Second Embodiment]
Next, a second embodiment of the finder according to the present invention will be described. The external configuration, side cross-section, and electrical configuration of the camera according to this embodiment are the same as those of the digital single-lens reflex camera 10 of the first embodiment shown in FIGS.

  FIG. 8 is a flowchart showing a finder display process according to the present embodiment. In addition, the same code | symbol is attached | subjected to the part which is common in the flowchart shown in FIG. 5, and the detailed description is abbreviate | omitted.

  In the present embodiment, backlight detection is performed (step S11), and when the subject video cannot be confirmed by OVF due to backlight, a contour image is superimposed and displayed on OVF and EVF (step S5).

  Backlight refers to a scene with high background brightness (bright) and low main subject brightness (dark). Therefore, the backlight detection can be detected by comparing, for example, the luminance of the main subject and the surrounding luminance.

  When the subject cannot be seen due to backlight in the OVF, the photographer can recognize the position of the subject by superimposing and displaying the contour image in the EVF. Furthermore, by superimposing the OVF, it is possible to eliminate the time lag that occurs in the EVF and to shoot at the photographer's preferred angle of view and timing.

[Third Embodiment]
Although the finder of the first and second embodiments is applied to a single-lens reflex type finder, the applicable finder is not limited to a single-lens reflex type. For example, the present invention can be applied to a camera finder in which the optical axis of OVF and the optical axis of EVF are different. Here, an inverse Galileo type finder will be described as an example.

  9 and 10 are a front perspective view and a rear perspective view, respectively, showing the external configuration of the digital camera 400 according to the present embodiment.

  As shown in the figure, the digital camera 400 of this embodiment includes a camera body 412 and a photographing lens 414 attached to the camera body 412.

  The photographing lens 414 may be configured to be detachable by a lens side mount and a camera side mount.

  An AF auxiliary light lamp 416, a finder switching lever 418, a finder objective 420, a grip 422, and the like are provided on the front of the camera body 412, and a shutter button 424, a power lever 426, an exposure correction dial 430, A shutter speed dial 432, an accessory shoe 434, a strobe 436, and the like are provided.

  On the back of the camera body 412, a viewfinder eyepiece 438, a command lever 440, a liquid crystal monitor 442, a cross button 448, a RAW button 450, a back button 452, an AE selection button 454, an AF selection button 456, a playback button 458, and the like. Is provided.

  Note that description of portions not related to the finder is omitted.

  Confirmation of the subject image is performed through the viewfinder eyepiece 438, and the photographer can observe the subject image by looking into the viewfinder eyepiece 438.

  FIG. 11 is a top sectional view of the digital camera 400. As shown in the figure, the digital camera 400 includes a CCD 500, a liquid crystal plate 510, an EVF lens 512, an objective lens 520, a prism 522, an eyepiece lens 524, and the like.

  The subject light that has passed through the photographing lens 414 enters the light receiving surface of the CCD 500. The CCD 500 that has received the subject light is converted into signal charges of an amount corresponding to the amount of incident light by each sensor, and image signals are generated from the signal charges by various signal processing circuits. An image obtained by inverting the subject image is displayed on the liquid crystal plate 510 based on the image signal.

  On the liquid crystal plate 510, a frame indicating the shooting range is displayed based on the focal length (angle of view) of the shooting lens 414.

  An EVF lens 512 is provided below the liquid crystal plate 510 in the drawing. A prism 522 is disposed between the EVF lens 512 and the eyepiece lens 524.

  The prism 522 includes a first prism 522a and a second prism 522b, and a half mirror surface 522M is formed at a portion where the first prism 522a and the second prism 522b are joined. The half mirror surface 522M is installed with an inclination of 45 ° with respect to the optical axis of the EVF lens 512. The image displayed on the liquid crystal plate 510 is enlarged by the EVF lens 512, and the left and right are reversed by the half mirror surface 522M and reflected to the right in the drawing. The image reflected by the half mirror surface 522M enters the eyepiece lens 524.

  In addition, the subject light incident on the objective lens 520 from a different path from the photographing lens 414 passes through the half mirror surface 522M and enters the eyepiece lens 524. A concave lens is used for the objective lens 520 and a convex lens is used for the eyepiece lens, which constitutes a reverse Galileo type finder.

  As described above, the digital camera 400 includes the OVF that guides the subject light incident from the finder objective 420 to the finder eyepiece 438 and the EVF that guides the image displayed on the liquid crystal plate 510 to the finder eyepiece 438. ing. And both are arrange | positioned on the same optical path by the half mirror surface 522M, The image | video is superimposed and it guides to the finder eyepiece part 438. FIG. That is, the two viewfinders function as a hybrid viewfinder that allows the photographer to observe the superimposed video. Therefore, by displaying the OVF subject video and the EVF contour video in a superimposed manner, the contour display according to the subject brightness and the result of the backlight detection can be performed as in the first and second embodiments.

  The electrical configuration of the digital camera 400 is the same as the block diagram shown in FIG. Thus, the present invention can be applied to a camera of a type in which the optical axis of light incident on the OVF and the optical axis of light incident on the EVF are different.

  In the case of the digital camera 400, an OVF image (a subject image incident from the objective lens 520 and transmitted through the half mirror surface 522M) and an EVF image (an image captured by the CCD 500 are displayed on the liquid crystal plate 510). Since the parallax occurs in the subject image reflected from the half mirror surface 522M, the positions in the respective images are different even for the same subject. Therefore, when superimposing and displaying the OVF image and the contour image by EVF, it is necessary to correct the parallax.

  In order to perform correction, first, it is necessary to measure the distance between the digital camera 400 and each subject. For example, a phase difference AF method may be used for the distance to each subject. In the phase difference AF method, light from a subject is acquired by a pair of distance measuring sensors, and the distance to the subject is calculated by triangulation from the phase difference of the outputs of the distance measuring sensors. Note that the distance to each subject may be measured by a different method.

  Next, based on the distance between the digital camera 400 and each subject calculated as described above, the contour of each subject in the contour image generated in advance matches the position of the same subject in the OVF video. Move.

  The contour image generated in this way is displayed with the contours of the subjects of the OVF video and the contours of the subjects of the contour image output to the EVF being matched.

  Further, when the angle of view between the OVF optical system (objective lens 520) and the EVF optical system (photographing lens 414) is different, the image captured by the CCD 500 is reduced based on the difference in the angle of view and the liquid crystal plate 510 is used. It may be displayed on.

  In the present embodiment, the display image of the liquid crystal plate is reversed left and right by the half mirror surface 522M, but may be configured to be reversed up and down. In this case, the liquid crystal plate may display an image that is inverted upside down.

  The technical scope of the present invention is not limited to the scope described in the above embodiment. The configurations and the like in the respective embodiments can be appropriately combined among the respective embodiments without departing from the spirit of the present invention.

  DESCRIPTION OF SYMBOLS 10 ... Digital SLR camera, 12 ... Camera body, 14, 414 ... Shooting lens, 24 ... Shutter button, 38 ... Viewfinder eyepiece, 42 ... LCD monitor, 100, 500 ... CCD, 110 ... LCD plate, 120 ... Quick Return mirror 122 ... Focusing screen 124 ... Penta prism 126, 524 Eyepiece 128 128 Field frame 235 Contour detection circuit 242 Display control circuit 301 Fireworks 302 Building 303 Window 400 ... Digital camera, 420 ... Object part, 438 ... Ocular part, 510 ... Liquid crystal plate, 512 ... EVF lens, 520 ... Objective lens, 522 ... Prism, 522M ... Half mirror surface, 524 ... Ocular lens

Claims (8)

An optical viewfinder,
An electronic viewfinder,
Superimposing means for superimposing a subject image incident on the optical viewfinder and a display image displayed by the electronic viewfinder;
Imaging means for converting a subject image received through the imaging lens into an image signal;
Contour extracting means for extracting the contour of the subject image from the image signal;
Contour image generation means for generating a contour image based on the extracted contour;
Display means for displaying the contour image on the electronic viewfinder;
A finder characterized by having. Photometric means for measuring subject brightness based on the image signal;
Control means for causing the contour extraction means to extract a contour when the measured subject luminance is not more than a predetermined value;
The finder according to claim 1, further comprising: Backlight detection means for detecting backlight for the subject based on the image signal;
Control means for causing the contour extracting means to extract a contour when a backlight is detected;
The finder according to claim 1 or 2, further comprising: The optical viewfinder is a single-lens reflex type finder,
The superimposing unit disposes the electronic viewfinder adjacent to the focusing screen of the optical viewfinder, thereby obtaining a subject image incident on the optical viewfinder and a display image displayed by the electronic viewfinder. The viewfinder according to any one of claims 1 to 3, wherein the viewfinder is superposed. The optical axis of the optical viewfinder is different from the optical axis of the imaging lens,
4. The contour image generation unit generates the contour image so that the contour of the extracted subject image matches the subject image incident on the optical viewfinder. 5. The finder according to item 1.   The superimposing means transmits the subject image incident on the optical viewfinder and reflects the display image displayed by the electronic viewfinder and the subject image incident on the optical viewfinder and the electronic viewfinder. The viewfinder according to claim 5, wherein the display image displayed by the method is superimposed. The finder according to any one of claims 1 to 6,
A release button for the photographer to input shooting instructions,
When a shooting instruction is input by the release button, an image signal is acquired from the image pickup unit, and a shooting unit that acquires a shot image based on the image signal;
An image pickup apparatus comprising: an image recording unit that records the acquired photographed image. In a finder display method comprising: an optical viewfinder; an electronic viewfinder; and a superimposing unit that superimposes a subject image incident on the optical viewfinder and a display image displayed by the electronic viewfinder.
An imaging process for converting a subject image received through an imaging lens into an image signal;
A contour extracting step of extracting a contour of the subject image from the image signal;
A contour image generating step for generating a contour image based on the extracted contour;
A display step of displaying the contour image on the electronic viewfinder;
A finder display method characterized by comprising:

Images