JP2013213954A - Finder device of camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a finder device of a camera that allows a photographer to visually recognize subject images provided by both an optical finder and an electronic view finder without requiring the photographer to change focus of eyes when switching between the optical finder and the electronic view finder is performed, so as to reduce the burden on the photographer's eyes.SOLUTION: A finder device of a camera includes imaging means for photographing a subject image, display devices 124 and 125 that display a picked-up image, and an optical finder including an ocular lens 121 for observing a primary imaging subject image formed into an image by a photographic lens. The display devices are arranged on an optical axis of the ocular lens to constitute an electronic view finder. Ocular lens focus changing means 132 is provided in order to change a focal distance of the ocular lens according to switching between the optical finder and the electronic view finder.

Description

The present invention relates to a camera finder device, and more particularly to a single-lens reflex camera having an optical viewfinder and an electronic viewfinder (EVF).

In recent years, even in a single-lens reflex camera, it is possible to shoot still images by so-called live view display that displays continuous shot images of an image sensor on an external display unit (display), and also to shoot moving images. At that time, the main mirror that guides the subject light to the optical viewfinder of the single-lens reflex camera is retracted out of the shooting optical path, so that the photographer of the camera cannot see the optical viewfinder image, and instead the external viewfinder placed on the back of the camera. Generally, an object scene image is viewed on the display unit. However, it is troublesome for the optical viewfinder and the external display section to change the posture of looking at the camera, and shooting with a single-lens reflex camera while looking at the external display section makes it difficult to fold the arm side and cause camera shake. It tends to be a stable posture. In particular, hand-held telephoto lens photography without using a tripod was impractical.

In order to solve this problem, a camera that can switch between an optical viewfinder and an electronic viewfinder has been proposed. If you can switch between the optical viewfinder and electronic viewfinder, you can shoot through the viewfinder of the camera in live view display shooting and movie shooting using the electronic viewfinder, as opposed to still image shooting using the normal optical viewfinder. The person's posture does not change. Therefore, it is possible to perform shooting while holding the camera in an ideal position.

Regarding the above technology, there are the following proposals. In one proposal, the main mirror is retracted out of the imaging optical path to block the optical viewfinder optical path, and the position of some of the reflecting mirrors of the penta member, which is the optical path converter, is changed. It is inserted from the outside of the penta member. Thus, the optical viewfinder is switched to the electronic view funder (see Patent Document 1). In another proposal, the reflection mirror of the penta member is made semi-transmissive, and the display member is arranged on the optical axis of the finder eyepiece on the back side of the semi-transmissive mirror, so that the optical viewfinder and the electronic viewfinder can be switched. (See Patent Document 2).

JP 05-107595 A JP 2000-292831 A

In general, an eyepiece constituting an optical viewfinder of a camera is such that an eye is focused on a focusing plate that is a primary imaging plane of a photographic subject image formed by a photographic lens (usually 1 m ahead). Designed to see objects). However, many proposals including the proposals of Patent Documents 1 and 2 are arranged such that the display member (display) is arranged not far from the primary image plane but far from the position of the eyepiece. For this reason, when the photographer switches from the state of observing the subject with the optical viewfinder to the electronic viewfinder, the object to be focused on is as follows. In other words, the subject image on the focus plate that is seen at a position equivalent to viewing an object existing 1 m ahead suddenly changes, for example, to a display member existing several tens of mm ahead. This is not only a burden on the photographer's eyes, but many people may not be able to focus on the display member.

Therefore, an object of the present invention is to provide a camera that allows a photographer looking into the viewfinder to easily view the subject image in both types without changing the focus of the eyes when switching the viewfinder method between the optical viewfinder and the electronic viewfinder. It is to provide a finder device. This greatly reduces the burden on the photographer's eyes and allows many people to always see a clear viewfinder subject image.

In order to achieve the above object, a finder device for a camera according to the present invention includes an imaging unit that captures a subject image formed by a photographic lens, a display device that displays a captured image obtained by the imaging unit, and imaging. An optical viewfinder including an eyepiece for observing a primary imaged object image formed by the lens; The display device constitutes an electronic viewfinder by being arranged on the optical axis of an eyepiece constituting the optical viewfinder. Furthermore, eyepiece focus changing means for changing the focal length of the eyepiece according to switching between the optical viewfinder and the electronic viewfinder is provided.

According to the present invention, since the eyepiece focus changing means is provided, the photographer looking into the finder can switch the both finder methods without changing the focus of the eye when switching between the optical viewfinder and the electronic viewfinder of the camera. The subject image can be easily visually recognized. Therefore, the burden on the photographer's eyes can be greatly reduced, and many people can always see a clear finder subject image.

Explanatory drawing of the finder structure of a camera. FIG. The electric block diagram of a camera. The flowchart which shows the outline of the imaging | photography sequence of a camera. Explanatory drawing of the operation member of a camera. Explanatory drawing of the other finder structure of a camera. Explanatory drawing of the other finder structure of a camera. Explanatory drawing of the other finder structure of a camera.

The feature of the present invention is that the focal length of the eyepiece is changed according to switching between the optical viewfinder and the electronic viewfinder so that the eye can be focused on the display device of the electronic viewfinder with the same diopter as the optical viewfinder. An eyepiece focus changing means is provided. Based on this idea, the camera finder device of the present invention has the basic configuration as described in the means for solving the above-mentioned problems.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
Example 1
A first embodiment of the finder apparatus according to the present invention will be described in detail with reference to FIGS. In FIG. 1 to FIG. 5, the same numbers are assigned to the same component parts.

FIG. 2 is a diagram illustrating a schematic configuration of a digital camera to which the finder device of the present embodiment is applied. In the figure, reference numeral 101 denotes a CPU (central processing unit), and the operation of the camera is controlled by the CPU 101. Reference numeral 105 denotes a photographing lens, which forms a picked-up image by imaging a photographing subject light on a CCD 106 that is an image pickup device (image pickup means). The photographing lens 105 shown in the figure is expressed by a single lens 105a for convenience, but actually comprises a plurality of lenses. Reference numeral 128 denotes a focus detection plate (also referred to as a focus plate in this specification) placed on an imaging plane (primary imaging plane) equivalent to the CCD 106 imaging plane of the taking lens 105. The subject image is reflected by the main mirror 126 and is primarily imaged on the focusing plate 128 to form a primary imaged subject image. The viewfinder device has a so-called TTL type optical viewfinder configuration in which a photographer can view the subject image through the pentaprism 127 and the eyepiece 121. On the other hand, the main mirror 126 is a semi-transmissive mirror, and a part of the light beam transmitted through the main mirror 126 is guided to the focus detection unit 119 which is a focus detection means through the sub mirror 122, and the focus of the known phase difference detection method. A detection operation is performed. The focus detection means can detect the focus for a plurality of areas (focus detection areas) on the shooting screen.

A photometric sensor 130 includes a plurality of sensor chips. The photometric lens 129 can divide a subject image formed on the focus plate 128 into a plurality of areas and detect the luminance of each of the plurality of areas. Reference numeral 112 denotes a display prism panel arranged in the vicinity of the focus plate 128, and a reflecting prism is formed at the surface position of the prism panel 112 corresponding to the focus detection area. The light from the LED 123 is projected from the upper opening of the pentaprism 127, and the reflected light of the reflecting prism is guided to the photographer's eyes, so that the focus in which focus detection area in the finder field is in focus. The status of the detection operation is displayed.

Here, when the photographer presses the release SW 114 (see FIG. 3), the main mirror 126 is retracted out of the optical path of the photographing lens 105. On the other hand, the amount of subject light collected by the photographing lens 105 is controlled by the focal plane shutter 133. Then, after being subjected to photoelectric conversion processing as a subject image by a CCD (imaging device) 106, it is recorded on a recording medium as a photographed image, and a photographed image is displayed on a TFT type external display unit 113. This is normal still image shooting, but the camera can also perform live view shooting and movie shooting.

At the time of live view shooting or moving image shooting, the subject image continuously captured by the CCD 106 is arranged on the front surface of the semitransparent reflection surface 127e on one plane of the pentaprism 127 and on the optical axis of an eyepiece 121 described later. Are displayed on the small TFT type internal display unit 124. With the above configuration, the photographer of this camera observes the subject with the optical viewfinder during normal still image shooting. On the other hand, even during live view shooting or moving image shooting, display by the internal display unit 124, that is, observation of a subject using a so-called electronic viewfinder, can be performed while keeping the same posture as looking through the optical viewfinder.

The camera automatically selects whether the images continuously picked up by the CCD 106 are displayed on the internal display unit 124 or the external display unit 113. A sensor (not shown) for detecting whether or not the photographer is looking through the viewfinder of the camera is provided in the vicinity of the eyepiece lens 121. Depending on the output, if the photographer is looking into the camera finder, the photographed image is displayed on the internal display unit 124. If the photographer is not looking into the camera finder, the image is displayed on the external display unit 113. Display is made. Here, the live view shooting means the next shooting. The main mirror 126 is retracted from the photographing optical path, the shutter 133 is opened, and the CCD 106 continuously captures images, for example, at an interval of 30 frames / minute, and the images are displayed on the external display unit 113 on the rear surface of the camera or on the electronic viewfinder. The internal display unit 124 continuously displays images. In this state, still image shooting is performed at an arbitrary timing. Furthermore, it is possible to perform moving image shooting for conversion to a moving image format and recording at an arbitrary timing from the Live View shooting state. Details of these operations will be described later.

Here, with reference to FIG. 1, the finder portion of this embodiment, which is a feature of the present invention, will be described in detail. In FIG. 1, an internal display unit 124 constituting an electronic viewfinder is a front surface of a semi-transmissive reflection surface 127 e of a pentaprism 127 constituting an optical viewfinder, and a vertical plane with respect to the optical axis of an eyepiece 121 that is a part of the optical viewfinder. Is arranged. The transflective surface 127e reflects 80% of the light flux incident on the eyepiece 121 from the focusing screen 128, thereby preventing the brightness of the subject image of the optical viewfinder from being significantly lowered and the internal display unit 124. It has the role of transmitting 20% of the luminous flux from. Here, reference numeral 125 denotes a backlight unit of the internal display unit 124, and the triangular prism 134 is for adjusting the optical path length in the vertical direction with respect to the eyes of the internal display unit 124 (for eliminating the vertical diopter difference). is there.

In general, an eyepiece for a finder of a single-lens reflex camera is such that when a camera photographer looks into the eyepiece, the subject image on the focus plate, which is the primary imaging plane of the photographing lens, can be seen 1 meter ahead. Designed. This is a value of -1 dpt (diopter). However, since the distance range in which a person's eyes are in focus varies from person to person, the eyepiece is configured with a mechanism that can vary the focal length. The eyepiece 121 is actually composed of fixed lenses 121a and 121c and a moving lens 121b, and the combined focal length of the three eyepieces changes as the position of the moving lens 121b changes. The camera photographer looks at the subject image formed on the focus plate when using the optical viewfinder, or the marking line of the photometry range mark (not shown) on the focus plate 128, etc. The moving lens 121b is moved and fixed at the position. This movement is indicated by a displacement amount ± e with respect to the position s of the moving lens 121b in FIG. As an actual adjustment operation, a diopter adjustment motor 132 for displacing the moving lens is driven by a button (not shown) which is an operation member of the camera. Then, the pedestal of the moving lens 121b moves along the screw thread portion provided on the shaft of the diopter adjustment motor 132, so that the moving lens 121b moves and determines its position. The amount of change in the diopter due to the change in the focal length of the eyepiece 121, the so-called diopter adjustment range, is possible with a width of ± 2dpt with -1dpt as the center. This is a so-called diopter adjustment mechanism, and many people do not need to adjust diopter again practically once appropriate adjustment is performed.

In general, Newton's imaging formula holds between the distance from the focal position of the lens to the image. If an object is placed in the direction approaching the lens starting from the focal position of the lens, the light beam will not form a real image, but will become a virtual image. As described above, the viewfinder forms a virtual image 1 meter ahead in this state with a diopter of -1 dpt. Defined. From this, the diopter of the finder is d = −1000 / (f ² / x−f) (1)
It can ask for. x is the distance from the object side focal position of the eyepiece to the object (in this case, the primary image plane of the focusing screen), and f is the focal distance of the eyepiece.

Here, when the (composite) focal length (f) of the eyepiece 121 is 70 mm, the focal point of the eyepiece 121 is located at a position (x) in the photographing lens direction 4.6 mm from the focus surface of the focus plate 128 from the equation (1). It can be seen that a diopter of −1 dpt is obtained if the eyepiece 121 is arranged so that the positions match. On the other hand, if the main mirror 126 is retracted out of the photographing optical path, the optical finder becomes invisible, and the subject image captured by the CCD 106 is displayed on the internal display unit 124 that is a display unit of the electronic viewfinder, the optical view until then. The observation target is moved from the focus plate 128 observed with the viewfinder to the internal display unit 124 arranged near the eyes. In this finder optical system, for example, it is assumed that the internal display unit 124 is disposed at a position 40 mm closer to the eyepiece lens 121 from the focusing surface of the focusing plate 128. Then, the distance x from the object-side focal position of the eyepiece to the object (display surface of the internal display unit 124): 44.6 mm, and the diopter −25 dpt is calculated from the calculation of the above equation (1). This means the same as observing an object (display surface) located only 40 mm from the photographer's eye. Accordingly, since the eye is out of focus for the majority of people, it is difficult to observe the electronic viewfinder display.

Therefore, the eyepiece focus changing means, which is a feature of the present invention, is as follows when the photographer uses the camera in the optical viewfinder state and switches to the electronic viewfinder. The moving lens 121b of the eyepiece 121 is moved from the position s in FIG. 1 to a position t in the eye direction of the photographer by a distance δ, and the combined focal length of the eyepiece 121 is changed. With this function, the photographer can focus on the display surface of the internal display unit 124 of the electronic viewfinder with the same diopter as the optical viewfinder.

According to the above equation (1), when the electronic viewfinder is used, the moving lens 121b is displaced as follows. That is, the combined focal length (f) of the eyepiece lens 121 is 30 mm at a position shifted by about 1 mm from the display surface of the internal display unit 124 in the direction of the photographing lens 105 (position 31 mm ahead of the main point position of the eyepiece lens 121). The focal position is displaced so as to match. Then, a -1 dpt diopter can be realized. The driving of the moving lens 121b is performed by the diopter adjustment motor 132 as described in the diopter adjustment mechanism. When the CPU 101 detects a switching signal from the optical viewfinder to the electronic viewfinder, the position of the moving lens 121b is detected by a position sensor (not shown). Then, the amount of movement of the moving lens 121b and the driving amount (number of pulses) of the diopter adjustment motor 132 necessary for the movement are calculated based on a formula programmed in advance by the CPU 101. The moving lens 121b is moved. In this way, -1 dpt diopter is realized.

Further, the diopter of the eyepiece lens 121 set to, for example, -3 dpt in the optical finder can be maintained at -3 dpt even when the electronic viewfinder is switched. In order to realize an optical finder of −3 dpt, the focal length (f) of the eyepiece lens 121 is 63.8 mm at the position of 10.4 mm closer to the photographing lens from the focusing screen image-formation surface, from the equation (1). What is necessary is just to move the position of the moving lens 121b so that a focus position may correspond. On the other hand, in the case of the electronic viewfinder, the moving lens is arranged so that the focal position where the focal length (f) of the eyepiece lens 121 is 28.6 mm coincides with the position 2.3 mm away from the display surface of the internal display unit 124. A diopter of −3 dpt can be obtained by moving the position 121b. Since the actual moving amount of the moving lens 121b is a design matter with the lens curvature, it is omitted here.

Conversely, when switching from the electronic viewfinder state to the optical viewfinder, the CPU 101 detects the position of the moving lens 121b and calculates the amount of movement each time the finder system is switched, so that the diopter adjustment motor 132 is driven. It has become. That is, even if the camera photographer performs diopter adjustment again at the time of the electronic viewfinder and then switches to the optical viewfinder, the state of the viewfinder diopter is maintained. In this way, the eyepiece focal point changing unit changes the focal length of the eyepiece so as to maintain the diopter before the focal length change according to whether the display device is displayed or not.

FIG. 3 is an electric block diagram showing a schematic configuration of the digital camera according to the present embodiment. In the figure, reference numeral 101 denotes the CPU (central processing unit) described above, and an EEPROM 101a which is a nonvolatile memory is configured therein. The CPU 101 is also supplied with a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, a data storage means 104, an image processing unit 108, a display control unit 111, a release SW 114, and a power source. DC / DC converters 117 are connected to each other, and a CCD control unit 107 and a CCD 106 are connected to the image processing unit 108. The CCD 106 has, for example, about 10 million effective pixels (3888 × 2592 pixels).

The external display unit 113 and the internal display unit 124 provided in the camera exterior back surface and the finder, respectively, are TFT color liquid crystals that can display images obtained by thinning the images captured by the CCD 106 in the vertical and horizontal directions. The display control unit 111 drives display of still images and moving images captured by the CCD 106 on the external display unit 113 and the internal display unit 124. Further, the focus detection state display LED 123 is also controlled. The motor control unit 125 receives instructions from the CPU 101, starts mirror driving, and controls a plurality of motors inside the camera, and the diopter adjustment motor 132 that moves the eyepiece 121b is also controlled here. Further, the DC / DC converter 117 is supplied with power from the battery 116.

The CPU 101 performs various controls based on a control program in the ROM 102. Among these controls, a process for reading a captured image signal output from the image processing unit 108 and transferring it to the RAM 103, a process for transferring data from the RAM 103 to the LCD control unit 111, and a process for transferring image data to JPEG There is a process of compressing and storing the data in the data storage means 104 in a file format. In the case of moving image data, the same processing is performed to compress it into a MOV format file and store it in the data storage means 104. Further, the CPU 101 instructs the CCD 106, the CCD control unit 107, the image processing unit 108, the LCD control unit 111, and the like to change the number of data fetching pixels and digital image processing. Reference numeral 119 denotes a focus detection control unit including a pair of line CCD sensors for focus detection, and A / D-converts the voltage obtained from the line sensor and sends it to the CPU. Further, based on an instruction from the CPU 101, the focus detection control unit 119 also controls the accumulation time of the line sensor and AGC (auto gain control). In addition, a process of outputting a control signal for controlling the supply of power to each element to the DC / DC converter 117 is also performed based on the control of the CPU 101 in accordance with the operation of the release SW 114. Furthermore, various processes such as calculating the amount of movement from the position of the eyepiece 121b, which is the moving lens, are performed under the control of the CPU 101 when switching between the optical viewfinder and the electronic viewfinder.

The RAM 103 includes an image development area 103a, a work area 103b, a VRAM 103c, and a temporary save area 103d. The image development area 103a is a temporary buffer for temporarily storing a captured image (YUV digital signal) sent from the image processing unit 108 or JPEG compressed image data read from the data storage unit 104, or an image. Used as an image-dedicated work area for compression processing and decompression processing. The work area 103b is a work area for various programs. The VRAM 103 c is used as a VRAM that stores display data to be displayed on the display unit 113. The temporary save area 103d is an area for temporarily saving various data.

The data storage unit 104 is a flash memory for storing captured image data or MOV format moving image data compressed by JPEG by the CPU 101 in a file format. The CCD 106 is an image sensor for converting a photographed image projected by the photographing lens 105 into an analog electric signal. The CCD 106 can output thinned pixel data in the horizontal and vertical directions in accordance with a resolution conversion instruction from the CPU 101. The CCD control unit 107 includes a timing generator for supplying a transfer clock signal and a shutter signal to the CCD 106, and a circuit for performing noise removal and gain processing of the CCD output signal. Furthermore, an A / D conversion circuit for converting an analog signal into a 10-bit digital signal, and a circuit for performing pixel thinning processing in accordance with a resolution conversion instruction from the CPU 101 are also included. Further, the image processing unit 108 performs image processing such as gamma conversion, color space conversion, white balance, AE, and flash correction on the 10-bit digital signal output from the CCD control unit 107, and YUV (4: 2: 2). ) Format 8-bit digital signal output. The photographing lens 105, the CCD 106, the CCD control unit 107, and the image processing unit 108 constitute an imaging unit.

The display control unit 111 receives the YUV digital image data transferred from the image processing unit 108 or the YUV digital image data obtained by performing JPEG decompression on the image file in the data storage unit 104, and converts it into an RGB digital signal. , Processing to output to the external display unit 113 or the internal display unit 124 is performed. The release SW 114 is for instructing the start of the photographing operation. The release SW 114 has a two-stage switch position according to the pressing pressure of a release button which is a camera operation member (not shown). When the first position (SW1ON) is detected, camera settings such as white balance and photometry are locked, and when the second position (SW2ON) is detected, the subject image signal is captured.

The photometry control unit 135 controls driving of the photometry sensor 130 in accordance with an instruction from the CPU 101, takes in a subject luminance signal, and sends data to the CPU 101. As a basic photometric operation, the luminance signals generated in the pixels on the light receiving surface of the photometric sensor 130 are each A / D converted by the CPU 101 to become 8-bit digital signals. Fno. Indicating the brightness of the photographing lens. (Effective Fno.) Value correction, sensor output signal variation correction (level / gain adjustment), and photometric correction from the information sent from the lens 105, etc., and finally the field luminance signal A value can be obtained. Based on these pieces of information, an optimal exposure calculation of the camera is performed, and an optimal exposure can be obtained by optimally controlling the shutter speed of the camera and the aperture of the photographing lens. The battery 116 is a rechargeable secondary battery or a dry battery. Further, the DC / DC converter 117 receives a power supply from the battery 116, generates a plurality of power supplies by performing boosting and regulation, and supplies a power supply of a necessary voltage to each element including the CPU 101. The DC / DC converter 117 can control the start and stop of each voltage supply by a control signal from the CPU 101.

Next, the shooting operation of the camera in the live view shooting mode will be described with reference to the flowchart of FIG. 4 and FIG. When the power of the camera is turned on in step S200 in the flowchart of FIG. 4, in step 201, the CPU 101 detects whether the switch operation member of the camera is set to the live view shooting mode. Here, the operation for setting the live view shooting mode and the moving image shooting will be described with reference to FIG. FIG. 5 shows a live view switch 140 and a moving image shooting switch 141 arranged on the exterior of the camera. The live view switch 140 is a rotary switch. When the protrusion of the switch is at the position of the shooting mode icon 142, the normal still image shooting mode is set, and when the protrusion is at the position of the icon 143, the shooting mode of the camera is set to the live view shooting mode. . When the start / stop button 141 is pressed in the live view shooting mode, the moving image shooting / recording is started, and the moving image shooting is stopped when the button is pressed again.

Returning to the flowchart of FIG. 4 again, if the camera is not set to the live view shooting mode in step 201, the operation in the normal still image shooting mode using the optical viewfinder is performed in step S220. This operation starts from turning on the release SW 114 and is a sequence common to a single-lens reflex still camera of still image shooting and recording, and is omitted because it is not directly related to the present invention. On the other hand, when the live view shooting mode is set, the CPU 101 executes a series of mechanical sequences in which the main mirror 126 is retracted out of the shooting lens optical path (mirror up) and the focal plane shutter 133 is kept open. At the same time as step S202, as step S203, the moving lens 121b of the eyepiece is moved by a predetermined amount in order to change the focal length of the eyepiece 121. This is because the diopter of the optical viewfinder and the diopter of the electronic viewfinder in the live view shooting mode are matched as described above. Specifically, the diopter at the time of the optical viewfinder, that is, the current position of the moving lens 121b is detected, and the CPU 101 calculates the diopter from the value. Then, the driving amount of the diopter adjustment motor 132 for moving the moving lens 121b is calculated so that the diopters when using the electronic viewfinder match. In step S204, the diopter adjustment motor 132 moves the moving lens 121b based on the calculated drive amount.

When the movement of the moving lens 121b is completed, the CCD 106 starts a photoelectric conversion process on the subject image formed on the CCD 106 chip by the photographing lens (step S205). Then, the subject image signal subjected to the electrical processing in step S206 is displayed on the internal display unit 124 of the electronic viewfinder. When the second position (SW2 ON) of the release SW 114 is detected in step S207, a normal still image shooting operation is performed in step S208, and the still image shooting is ended in step S209.

On the other hand, if SW2 ON is not detected in step S207, it is detected in step S210 whether the video shooting switch 141 is ON. If it is ON, recording is started in step S211 and in the OFF state. If there is, the process returns to the detection of SW2ON in step S207 again. If it is detected in step S212 that the moving image shooting switch 141 is OFF, moving image shooting is terminated in step S213. If it is not detected that the movie shooting switch 141 is turned off, movie shooting is continued. When shooting of still images and moving images is completed in step S209 and step S213, it is detected in step S214 whether or not the live view shooting mode is set. If it is still in the live view shooting mode, the process returns to step S207 to determine whether SW2ON is detected.

On the other hand, when it is detected that the mode is changed to the still image shooting mode instead of the live view shooting mode, the CPU 101 stops the live view imaging operation of the CCD 106 in step S215. At the same time, the display on the internal display unit 124 of the electronic viewfinder is also stopped in step S216. Subsequently, in step S217, the CPU 101 executes a series of mechanical sequences that return the main mirror 126 to the photographing lens optical path (mirror down) and keep the focal plane shutter 133 in the closed state. At the same time, in step S218, the CPU 101 calculates the diopter by detecting the current position of the moving lens 121b in order to return to the diopter of the optical viewfinder, and the movement of the moving lens 121b to be positioned at the time of the optical viewfinder. Calculate the amount. In step S219, the diopter adjustment motor 132 moves the moving lens 121b based on the calculated amount. That is, the live view shooting mode is completely stopped here, and the process proceeds to the still image shooting mode sequence in step S220.

(Example 2)
Next, Embodiment 2 of the present invention will be described with reference to FIG. In FIG. 6, except for the configuration of the eyepiece lens 121, the elements constituting the finder including the internal display unit 124 are exactly the same as those of the first embodiment shown in FIG. The only different configuration of the eyepiece 121 is composed of fixed lenses 121a and 121c, a moving lens 121b, and a focus correction lens 121d that is inserted into and retracted from the optical axis of the eyepiece. The focus correction lens 121d has positive power, and is inserted into the optical axis of the eyepiece lens 121, so that the combined focal length of the eyepiece lens 121 is shortened and the eye is focused on the internal display unit 124 at the time of the electronic viewfinder. Play a role. In other words, the focus correction lens 121d is inserted into the eyepiece lens 121 optical axis (i position) when switching from the optical viewfinder to the electronic viewfinder, and conversely, when switching from the electronic viewfinder to the optical viewfinder, the light of the eyepiece lens 121 is inserted. It is retracted (h position) from the shaft. As a result, the photographer of the camera can see a focused subject image in both the optical viewfinder and the electronic viewfinder. This insertion / retraction operation is performed instantly with a spring and a plunger (not shown). Of course, this operation may be performed by rotating or sliding using a motor.

Here, if the focus correction lens 121d is simply inserted and retracted, the following occurs. Even if the finder method is switched as in the optical viewfinder or the electronic viewfinder, the diopter can be reduced to −1 dpt in each case by the optimum design of the focus correction lens 121d. However, if the photographer arbitrarily sets the diopter according to his / her own eye, the same diopter may not be accurately maintained when the finder method is changed. Therefore, as in the first embodiment, the CPU 101 reads the position of the moving lens 121b for performing diopter correction, calculates the required drive amount, and drives it so that the diopters in both finder systems are the same. Correction has been made. In the case of the present embodiment, as compared with the case where the focal length change of the eyepiece lens 121 is all performed by the movement of the moving lens 121b as in the first embodiment, the movement amount ± e of the moving lens 121b is small, and the entire eyepiece lens 121 is changed. There is a possibility that it may be smaller than the configuration of the first embodiment.

In the description of the first and second embodiments described above, the arrangement of the internal display unit (display device) 124 is as shown in FIGS. That is, the internal display unit 124 that constitutes the electronic viewfinder is disposed on the front surface of the semi-transmissive reflection surface 127e of the pentaprism 127 that constitutes the optical viewfinder and on the optical axis vertical plane of the eyepiece 121 that is a part of the optical viewfinder. It was. However, the arrangement of the internal display unit 124 is not limited to the above arrangement.

(Example 3)
FIG. 7 shows a viewfinder configuration in which an internal display unit, which is a transparent organic EL 136 composed of a dot matrix panel, is arranged above the focus plate 128. The transparent organic EL 136 of this configuration is transparent when not driven, and when the optical viewfinder is used, it superimposes on the optical subject image and displays the focus detection operation status display as a partial symbol of dots. When the main mirror 126 enters the live view shooting mode or the moving image shooting mode in a state where the main mirror 126 is retracted out of the shooting optical path of the shooting lens 105 and the optical finder optical path is blocked, the following functions. That is, the transparent organic EL 136 functions as an electronic viewfinder that displays a subject moving image as a dot matrix display.

Even in such a finder system, it is impossible to match the visibility of the display portion of the transparent organic EL 136 with respect to the focus plate 128 due to the glass thickness of the base material of the transparent organic EL 136. Further, the display position is actually shifted by 1 mm or more depending on the mechanical holding method. Assuming that the display light emitting surface of the transparent organic EL 136 is 2 mm away from the focusing screen 128 (on the optical path and in the direction of the eyepiece), the diopter is calculated from the formula (1) as follows: With respect to 0.0 dpt, the diopter of the display light emitting surface is −1.5 dpt, and a difference of 0.5 dpt appears. This degree of diopter difference is practical even when the object is viewed simultaneously with the optical subject image, as long as it is a symbol display (photographing mode, ISO display, etc.) of the transparent organic EL 136 that is an auxiliary display at the time of the optical viewfinder. There may be no problem. However, if it is intended to strictly observe the in-focus state of the taking lens 105 as a display of an electronic viewfinder, the moving lens 121b is moved in conjunction with the switching of the viewfinder method, and the diopter of the internal display unit is changed to that of the optical viewfinder. It is desirable to adjust to match the degree.

Example 4
FIG. 8 shows a viewfinder configuration in which a small TFT type internal display unit 124 is arranged on the upper part of the pentaprism 127. In general, the upper part of a pentagonal prism of a single-lens reflex camera is usually a roof surface, and the viewfinder object image reflected by this surface is reversed left and right. The roof surface that reverses right and left is provided on a surface 127e that is a normal reflecting surface. By making the surface 127a a flat surface, the internal display unit 124 can be easily arranged. Reference numeral 137 denotes a triangular prism that corrects the optical path length difference in the vertical direction of the internal display unit. Again, the backlight unit 125 of the internal display unit 124 is provided. The finder configuration having the internal display unit is characterized in that the internal display unit 124 is arranged on the surface 127a of the pentaprism as compared with the case where the internal display unit of the first and second embodiments is disposed in front of the surface 127e of the pentaprism 127. By being arranged, the focus plate 128 becomes closer. For this reason, the diopter change of the eyepiece 121 due to the finder method switching can be reduced. That is, since the movement amount δ of the moving lens 121b of the eyepiece 121 can be small, it contributes to downsizing of the camera.

In the example of the finder configuration described with reference to FIGS. 7 and 8 having the internal display unit arranged differently from the first and second embodiments, the finder method is switched as in the first and second embodiments. In this case, the eyepiece 121 is maintained at the same diopter.

The preferred embodiments of the present invention have been described above, but the present invention is not limited to these examples. For example, in the description of the finder configuration so far, it has a pentaprism made of glass, but naturally it can be applied to the present invention even with a configuration of a pentamirror using a reflection mirror as an optical path changing means. Therefore, various modifications and changes can be made within the scope of the gist. When a pentamirror is used, since the finder optical path in the pentamirror is air, the internal display unit, which is the display device, is arranged in the space of the pentamirror and on the vertical axis of the optical axis of the eyepiece 121. be able to. That is, there is a feature that the degree of freedom of layout of the internal display unit is increased.

105: photographing lens, 106: CCD (imaging means), 121: eyepiece lens (optical viewfinder), 121b: moving lens, 121d: focus correction lens (eyepiece focus changing means), 124: internal display unit (display, display device) ), 125: Backlight (display device), 127: Penta prism (optical viewfinder), 132: Diopter adjustment motor (eyepiece focus changing means)

Claims (6)

Imaging means for imaging a subject image formed by the taking lens;
A display device for displaying a captured image obtained by the imaging means;
An optical viewfinder including an eyepiece for observing a primary imaged object image formed by the taking lens;
A camera finder device comprising:
The display device constitutes an electronic viewfinder by being arranged on the optical axis of an eyepiece constituting the optical viewfinder,
A finder apparatus comprising eyepiece focus changing means for changing a focal length of the eyepiece according to switching between the optical viewfinder and the electronic viewfinder. The eyepiece focus changing means changes the focal length of the eyepiece so as to maintain the diopter before the focal length change according to the display / non-display of the display device. The camera finder device described. The viewfinder device according to claim 1, wherein the eyepiece focus changing unit changes the focal length of the eyepiece by moving at least one lens of an eyepiece composed of a plurality of lenses. The viewfinder device according to claim 1, wherein the eyepiece focus changing unit changes a focal length of the eyepiece by inserting a focus correction lens into an optical path of the optical viewfinder. 5. The display device according to claim 1, wherein the display device is disposed on a front surface of a semi-transmissive reflection surface of a pentaprism constituting the optical finder and a surface perpendicular to an optical axis of the eyepiece lens. The finder device according to claim 1. 5. The display device according to claim 1, wherein the display device is disposed in a plane perpendicular to an optical axis of the eyepiece lens in a space of a pentamirror that constitutes the optical viewfinder. The finder device according to item.

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