JP2006121193A - Digital camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital camera for producing image data whereby a user views an imaged image almost in a natural state even when other display apparatus than a projection type display apparatus is in use. <P>SOLUTION: When an operation section 45 sets a field angle for viewing, a focal distance control means changes a focal distance of a photographing lens 31 so that a photographing field angle of the digital camera 1 is equal to the field angle for viewing and changes the focal distance of the photographing lens 31 at object photographing so that the size of an object image displayed on the display apparatus is the same as the size of an actual object. Further, when there exists an image having already been photographed, a control section 24 acting like an image magnification means magnifies or reduces the photographed object image so as to obtain the image with the same photographing angle as the field angle for viewing and magnifies or reduces the photographed object image so that the size of the object image displayed on the display apparatus is equal to the size of the actual object. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a digital camera.

  When viewing an image (subject image) taken with a digital camera, it is common to view the image by printing it on paper. In recent years, however, a large-screen display device or projector such as an LCD or PDP has been used. In many cases, a photographed image is enlarged and displayed on a large screen. This enlarged display method is very useful in that the viewer can easily understand the shape, arrangement, and details of the subject image.

On the other hand, a subject is often displayed on a display device and viewed in a manner that is close to natural. For example, in Patent Document 1, the projector performs zoom control of the projection optical system or moves the apparatus main body so that the actual display size substantially matches the target display size (for example, the actual size or an arbitrary size). The projection distance from the main body to the screen is adjusted. In this configuration, a display image can be obtained in full size without performing troublesome operations such as manual key operation and movement of the apparatus position.
JP 2002-297119 A

  However, the technique disclosed in Patent Document 1 performs zoom control and adjustment of the projection distance on the projector side which is a display device, and the usable display device is limited to the projector (projection type display device). Therefore, in the configuration of Patent Document 1, there is a problem that a captured image cannot be viewed with a natural appearance on other display devices (for example, a wall-mounted LCD or PDP).

  The present invention has been made to solve the above-described problems, and its purpose is to appreciate a captured image with a natural appearance even when a display device other than a projection display device is used. An object of the present invention is to provide a digital camera that generates such image data.

  The digital camera of the present invention is a digital camera that captures a subject image by exposing an image sensor, and includes a photographing lens that forms the subject image on the image sensor, and a focal point that controls the focal length of the photographing lens. A distance control means and an angle-of-view setting means for setting an angle of view for viewing the display device, and the focal length control means is configured so that the shooting angle of view is equal to the angle of view of the viewing lens. It is characterized by changing the focal length.

  According to the above configuration, when the viewing angle is set by the viewing angle setting unit, the focal length control unit changes the focal length of the photographing lens so that the shooting field angle with the digital camera becomes equal to the viewing angle of view. To do. Note that the focal length change at this time may be automatically performed by the focal length control means, or may be performed after a focal length change instruction is manually input, for example.

  Thus, in the digital camera, the subject image is captured at the focal length, and the image data of the captured image is transmitted to a display device (for example, LCD or PDP), and the display device displays the captured image based on the image data. Sometimes, the viewer can view the photographed image at the same angle of view as when photographing. Therefore, when viewing a captured image with a natural appearance, there is no special processing or operation on the display device side, such as zoom control and adjustment of the projection distance, as in the past using a projection display device. It will be over. As a result, according to the above configuration, even when a display device other than the projection type display device is used, the captured image can be viewed with a natural appearance.

  Further, in the digital camera of the present invention, the focal length control means may be configured such that the photographing field angle is equal to the viewing angle based on the length of the imaging region of the image sensor and the viewing angle. The focal length may be calculated and changed to that.

  It is possible to calculate the focal length of the photographic lens so that the photographic angle of view becomes equal to the viewing angle of view from the length of the imaging region of the imaging element (for example, the length in the long side direction) and the viewing angle of view. . Therefore, since the focal length control means calculates the focal length and changes the focal length of the photographing lens, the subject image is photographed at the focal length, and the image data of the photographed image is transmitted to the display device. When the display device displays a photographed image based on the image data, the viewer can surely appreciate the photographed image at the same angle of view as when photographing.

  In addition, the digital camera of the present invention preferably has a configuration further including output means for outputting image data of a subject image taken at a shooting angle of view equal to the viewing angle of view to the display device. According to this configuration, since the image data of the subject image is reliably supplied from the output means to the display device, any display device that performs display based on the digital image data can be used. The viewer can view the photographed image at the same angle of view as when photographing.

  The digital camera of the present invention is a digital camera that captures a subject image by exposing an image sensor, and includes an image scaling unit that enlarges or reduces the captured subject image, and an appreciation image when the display device is viewed. Angle of view setting means, and the image scaling means enlarges or reduces the subject image so that an image having the same shooting angle of view as the viewing angle of view can be obtained.

  According to the above configuration, the image scaling unit enlarges or reduces the captured image (subject image) so that an image having the same shooting field angle as the viewing angle set by the field angle setting unit can be obtained. To do. With this scaling process, an image with the same shooting angle of view as the viewing angle of view can be obtained from an already shot image. Thus, when the image data is transmitted to a display device (for example, LCD or PDP) and the display device displays an image based on the image data, the viewer takes a photographed image with the same viewing angle of view. Can be appreciated. That is, when a captured image is viewed with a natural appearance, there is no need to perform any special processing on the display device side as in the past. Therefore, according to the above configuration, even when a display device other than the projection display device is used, the captured image can be viewed with a natural appearance.

  The digital camera of the present invention stores a photographing lens for forming the subject image on the image sensor and a focal length of the photographing lens when the subject is photographed as a first focal length, and the viewing angle of view. And a focal length storage means for storing the focal length of the photographing lens as the second focal length so as to have the same photographing angle of view as the first focal length and the second focal length. Based on the above, the zoom ratio (enlargement ratio, reduction ratio) of the subject image may be calculated, and the subject image may be enlarged or reduced at the zoom ratio.

  From the first focal length and the second focal length stored in the focal length storage means, it is possible to determine the magnification ratio of the subject image so that the shooting angle of view is the same as the viewing angle of view. Therefore, the image scaling unit calculates the scaling ratio and enlarges or reduces the already captured subject image by the ratio. As a result, the image after the scaling process is equivalent to that taken at the same shooting angle of view as the viewing angle of view. Therefore, when the image data after the scaling process is transmitted to the display device and the display device displays an image based on the image data, the viewer surely views the captured image at the same viewing angle of view as the shooting angle of view. Therefore, the photographed image can be surely viewed with a natural appearance.

  The digital camera of the present invention preferably further includes an output unit that outputs image data of the subject image enlarged or reduced by the image scaling unit to the display device. According to this configuration, since the image data output from the output unit is image data that allows a photographed image to be viewed at the same viewing angle of view as the shooting angle of view, a display device that performs display based on the image data. Even without performing any special image processing (for example, enlargement / reduction processing), the viewer can view the captured image at the same viewing angle as the shooting angle of view on the display device.

  The digital camera of the present invention is a digital camera that captures a subject image by exposing an image sensor, and includes a photographing lens that forms the subject image on the image sensor, and a focal point that controls the focal length of the photographing lens. A distance control unit; and an output unit that outputs image data of the subject image obtained by photographing to a display device. The focal length control unit is configured to output a subject image displayed on the display device based on the image data. The focal length of the photographing lens at the time of photographing the subject is changed so that the size is the same as the actual subject.

  According to the above configuration, the display device displays the subject image based on the image data of the subject image output from the output unit. At this time, the focal length control means changes the focal length of the photographing lens at the time of photographing the subject so that the size of the subject image displayed on the display device becomes the same size as the actual subject. Thus, when the subject is photographed at the changed focal length and the image data after photographing is output from the output means to the display device, the display device does not perform any special processing (for example, enlargement / reduction processing). However, the subject can be displayed in full size. Therefore, even when a display device other than the projection type display device is used, the photographed image can be viewed with a natural appearance.

The digital camera of the present invention further includes an angle-of-view setting means for setting an angle of view for viewing the display device, and the distance from the viewing position of the display device to the display device is D _M. The focal length control means is obtained based on the viewing angle of view, where f _{M is} the focal length of the photographic lens when the display device is in focus at the position, and D is the distance from the camera to the subject. Based on the distance D _M and the focal distance f _M and the distance D obtained when focusing on the subject, the size of the subject image displayed on the display device is the same size as the actual subject. The focal length (f _E ) of a simple photographic lens may be calculated and changed to that.

From the distance D _M , the distance D, and the focal length f _M , calculating the focal length f _E of the photographing lens so that the size of the subject image displayed on the display device is the same size as the actual subject. Is possible. Therefore, the focal length f _E of the photographic lens can be obtained reliably by using such parameters.

  The digital camera of the present invention is a digital camera that captures a subject image by exposing an image sensor, and includes an image scaling unit that enlarges or reduces the captured subject image, and a display device that displays the image data of the subject image. Output means for outputting, and the image scaling means is photographed so that the size of the subject image displayed on the display device is the same size as the actual subject based on the image data It is characterized by enlarging or reducing the subject image.

  According to the above configuration, the image scaling unit enlarges or reduces the photographed subject image so that the size of the subject image displayed on the display device is the same size as the actual subject. When the display device displays an image based on the image data of the enlarged or reduced image output from the output means, the viewer can view the subject image at the same magnification, and the subject can be viewed with a natural appearance. You can appreciate the images.

  That is, image data that can be displayed at the same magnification is generated on the digital camera side, so that no special processing or operation is required on the display device side. Therefore, any display device that performs display based on digital image data (even a display device other than a projection display device) can appreciate a captured image with a natural appearance. .

The digital camera of the present invention further includes a photographic lens for forming the subject image on the image sensor, and an angle-of-view setting unit for setting an angle of view for viewing the display device. D _{M is} the distance from the viewing position to the display device, f _{M is} the focal length of the photographic lens when the display device is in focus at the viewing position, D is the distance from the camera to the subject, and Assuming that the focal length of the taking lens when focusing is f _D , the image scaling means focuses the subject on the distance D _M and the focal length f _M obtained based on the viewing angle of view. based on the distance D and the focal length f _D obtained when, calculates the magnification ratio such size of the object image displayed on the display device is the same size as the actual object, photographed An object image may be configured to reduce or enlarge the ratio.

From the distance D _M and the focal distance f _M and the distance D and the focal distance f _D , a zoom ratio is calculated so that the size of the subject image displayed on the display device is the same as that of the actual subject. Is possible. Since the image scaling means calculates such a scaling ratio based on the above parameters, the image data of the image that can be displayed at the same magnification on the display device can be reliably generated on the digital camera side, By scaling the original image at that ratio, it is possible to reliably obtain an image that can be displayed at the same magnification.

  In the digital camera of the present invention, the angle-of-view setting unit may be configured such that when the display device is viewed through the camera finder at the viewing position of the display device, the upper and lower ends or the left and right ends of the finder and The configuration may be such that the viewing angle of the camera when the end or the left and right ends coincide with each other is set as the viewing angle of view. By setting the viewing angle as the viewing angle, the viewing angle can be obtained reliably and easily.

  According to the present invention, image data of a shooting angle of view equal to the viewing angle of view or an image that can be displayed at the same magnification is generated on the digital camera side, and display is performed based on the image data of the shot image of the digital camera. When a captured image is viewed with a display device that looks close to nature, there is no need to perform any processing or operation on the display device side. As a result, if the display device performs display based on digital image data, the photographed image can be viewed with a natural appearance even when a display device other than the projection display device is used.

[Embodiment 1]
An embodiment of the present invention will be described below with reference to the drawings.

(1. Appearance structure of digital camera)
FIG. 2 is a perspective view showing an external configuration of the digital camera 1 in the present embodiment, and FIG. 3 is a rear view of the digital camera 1. The digital camera 1 captures a subject image by exposing a CCD 32 (see FIG. 1), which will be described later, and has a camera body 2 having a substantially rectangular parallelepiped shape. The camera body 2 is formed by bonding a front cover 2a and a rear cover 2b. On the front surface of the camera body 2, a photographing lens 3, a flash light emitting unit 4, and a grip / battery cover 5 are provided. Further, an electronic viewfinder window 6, a display unit 7, a mode selection dial 8, a selection button 9, a zoom lever 10, and a plurality of operation keys 11 are provided on the rear surface of the camera body 2. Further, a power switch 12 and a release button 13 are provided on the upper surface of the camera body 2.

  The photographing lens 3 is composed of a zoom lens or the like, and is used to form a subject image on an image sensor (CCD 32) installed behind the lens. The flash light emitting unit 4 emits flash light that illuminates the subject to be photographed. The grip / battery lid 5 is a lid that is held by a user when photographing a subject and is opened and closed when the battery is inserted into and removed from the camera body 2. The grip / battery cover 5 is provided from the front surface to the side surface and the back surface of the camera body 2.

  The electronic viewfinder window 6 is an eyepiece part of an electronic viewfinder (hereinafter abbreviated as EVF). The EVF includes a small display device and a lens inside, and displays an image picked up by an image pickup device (CCD 32), thereby providing a subject image to a user. The display unit 7 displays various information such as the photographed subject image, the setting status of the digital camera 1, operation guidance, and the like. The display unit 7 is composed of, for example, a liquid crystal display device (LCD), and serves as an external finder (monitor) during photographing. It also has a function. In this case, the same captured image is displayed on the electronic viewfinder window 6 and the display unit 7.

  The mode selection dial 8 is adjusted by the user when selecting an operation mode (photographing, reproduction, setup) of the digital camera 1. The selection button 9 is a button for moving the cursor to select a desired item from items displayed on the display unit 7. The zoom lever 10 is a lever for adjusting the position of the zoom lens 31b (see FIG. 1). The operation keys 11 are used for settings related to functions of the digital camera 1 such as switching of items to be displayed on the display unit 7 and selection of displayed items.

  The power switch 12 is a switch for switching on / off the power of the digital camera 1. The release button 13 operates in two stages and is used for an instruction for preparing to shoot an image to be recorded and an instruction to shoot an image to be recorded. The digital camera 1 has functions of automatic focus adjustment (AF) and automatic exposure control (AE), and performs AF and AE in preparation for photographing.

(2. Internal structure of digital camera)
Next, the internal configuration of the digital camera 1 will be described with reference to FIG. FIG. 1 is a block diagram showing a detailed configuration inside the camera body 2 of the digital camera 1. The digital camera 1 includes an imaging unit 21, a drive unit 22, an output unit 23, a control unit 24, and a storage unit 25. Hereinafter, it demonstrates in order.

  The imaging unit 21 includes a photographic lens 31, a CCD 32, a signal processing circuit 33, an A / D conversion unit 34, an image processing circuit 35, and an image memory 36.

  The photographing lens 31 corresponds to the photographing lens 3 of FIG. The photographic lens 31 is composed of a plurality of lenses and a diaphragm, and forms the captured subject image on the CCD 32. The plurality of lenses include a focusing lens 31a and a zoom lens 31b. Moreover, in order to change the amount of incident light, the aperture diameter of the stop can be adjusted.

  The CCD 32 is an image sensor that has a plurality of pixels arranged two-dimensionally and outputs an electrical signal corresponding to the amount of light received through the photographing lens 31 from each pixel. That is, the CCD 32 converts the subject image incident through the photographing lens 31 into R (red), G (green), and B (blue) color component image signals (a signal sequence of pixel signals output from each pixel). Output after photoelectric conversion.

  The signal processing circuit 33 performs correlated double sampling (CDS) and automatic gain control (AGC) processing on the analog signal output from the CCD 32 to reduce noise and adjust the level of all signals.

  The A / D converter 34 converts the analog signal output from the signal processing circuit 33 into a digital signal (for example, 10 bits). The image processing circuit 35 performs processes such as white balance adjustment, γ correction, color correction, and compression based on the digital signal (image data of the captured image) output from the A / D conversion unit 34. The image memory 36 stores the image data processed by the image processing circuit 35.

  The drive unit 22 includes a timing control circuit 37, a focus adjustment control circuit 38, a zoom drive control circuit 39, and a flash control circuit 40.

  The timing control circuit 37 generates various timing pulses for controlling the driving of the CCD 32 and controls the processing in the signal processing circuit 33 and the A / D converter 34 to be synchronized with the imaging operation in the CCD 32. . The focus adjustment control circuit 38 drives and controls the focusing lens 31a of the photographic lens 31 to adjust the focus. The zoom drive control circuit 39 drives and controls the zoom lens 31b of the photographing lens 31 to perform zoom adjustment. The focus adjustment control circuit 38, the zoom drive control circuit 39, and the control unit 24 described later function as a focal length control unit that controls the focal length of the photographing lens 31. The flash control circuit 40 controls light emission of the flash by the flash light emitting unit 4.

  The output unit 23 includes a VRAM (Video Random Access Memory) 41, a card I / F 42, and a communication I / F 43.

  The VRAM 41 is a memory that holds an image displayed on the display unit 7. The card I / F 42 is an interface for outputting image data to a memory card 44 that is a removable recording medium. The communication I / F 43 is used to output image data and transmit / receive control signals to / from an external device such as an LCD 51 (see FIG. 7) serving as a display device to be described later, an electrically connected personal computer, printer, and the like. Interface. Although not shown, the output unit 23 also has a VRAM as a memory for holding an image displayed on the EVF.

  The control unit 24 controls the operation of each unit described above and performs various calculations. Control in the control unit 24 is performed based on an operation input in the operation unit 45. In particular, in the present embodiment, the control unit 24 calculates the focal length of the photographic lens 31 so that the later-described viewing angle of view set and input by the operation unit 45 is equal to the shooting angle of view. The operation unit 45 includes the mode selection dial 8, the selection button 9, the zoom lever 10, and the plurality of operation keys 11 described above.

  The storage unit 25 stores the viewing angle of view set and input by the operation unit 45 and stores the focal length of the photographing lens 31 calculated by the control unit 24.

(3. Concept of the invention according to this embodiment)
Next, the concept of the present invention that enables an image captured by the digital camera 1 having the above-described configuration to be viewed on a display device with a natural appearance will be described below.

  FIG. 4 shows a situation where the photographer is photographing a landscape (for example, a mountain) using the digital camera 1. FIG. 5 is an image obtained by the digital camera 1 when the landscape is photographed on the wide angle side, and FIG. 6 is an image obtained by the digital camera 1 when the landscape is photographed on the telephoto side.

  On the other hand, FIG. 7 shows the positional relationship between the LCD 51 and a viewer who views the display image of the wall-mounted LCD 51 (display device) installed in the home. 5 and 6 taken by the digital camera 1 are displayed on the screen 51a (display area) of the LCD 51, and when the viewer views these images, these display images have an angle of view ( Since the shooting angle of view is different, the viewer receives a completely different impression between these displayed images. This means that, depending on the display image, it is difficult to estimate how much the landscape (mountain) was actually seen at the shooting site. In addition, there is no problem in evaluating the artistry of the work based on the display image, but in the case of photographs for academic use or architectural use, it is sometimes necessary to express an actual scale feeling.

  In addition, it is often experienced that the perspective is exaggerated or compressed more than the actual depending on the focal length of the taking lens 31, and when shooting at a wide angle, the person at the edge of the screen may appear fat. Are known. Furthermore, when a large building or vehicle is photographed with a super-wide-angle lens or the like and viewed with a small paper photograph or the like, there are many cases where the user feels a sense of discomfort with the real thing. These occur because the shooting angle of view of the photographic lens 31 at the time of shooting differs from the viewing angle of view at the time of print viewing (the viewing angle of view determined by the print size that can be seen by human eyes).

  The present invention solves such problems, and has the greatest feature that the digital camera 1 generates image data that allows a photographed image to be viewed with a natural appearance. As one of them, in this embodiment, the shooting angle of view of the digital camera 1 during shooting of the subject is set to be equal to the viewing angle of view of the viewer when viewing the display image on the LCD 51. As a result, even when evaluating the design of a passenger car or a railway vehicle or an image of a very large subject such as a building, it is possible to appreciate the image with a natural perspective without exaggerating it. The details will be described below.

FIG. 8 is a plan view schematically showing the positional relationship between the LCD 51 and the viewer in FIG. Here, W _M represents the horizontal length of the screen 51a of the LCD 51, L represents the distance between the screen 51a of the LCD 51 and the viewer, and θ _M represents the image displayed on the screen 51a. Shows an angle of view for viewing (horizontal angle of view in this case). The viewing angle of view refers to an angle at which both ends of the screen 51a are stretched with respect to the viewer.

  On the other hand, FIG. 9 is a plan view schematically showing the positional relationship between the photographing lens 31 and the CCD 32 of the digital camera 1 used when photographing the subject shown in FIG. Here, S is the distance between the principal point H of the photographing lens 31 and the element surface of the CCD 32 in a state where the scenery (mountain) is in focus, and is represented by S = f (1 + β). Note that f indicates the focal length of the photographing lens 31, and S≈f when photographing a distant landscape as shown in FIG. Further, β represents a photographing magnification, and θc represents an angle of view at the time of photographing (photographing angle of view). The field angle of view indicates an angle at which both ends of the element surface of the CCD 32 are stretched with respect to the principal point H. Further, wc indicates the length of the imaging region of the CCD 32 (here, the length in the horizontal direction).

Now, if the focal length of the taking lens 31 so that the viewing angle of view θc and the viewing angle of view θ _M are equal is f _M , if this f _M can be obtained, the focal point of the taking lens 31 is obtained to the obtained f _M. distance change the, by performing photographing by a digital camera 1, it is possible to perform photographing at equal appreciation angle theta _M imaging angle .theta.c. Hereinafter, a procedure for obtaining f _M will be described.

From FIG.
tan (θc / 2) = (wc / 2) / S = wc / 2S
Because
θc / 2 = tan ⁻¹ (wc / 2S)
θc = 2 tan ⁻¹ (wc / 2S) (1)
It becomes.

On the other hand, when the photographing magnification β of the digital camera 1 is set to β _M , β _M = wc / W _M is expressed, and S is expressed as follows.
S = f _M (1 + β _M )
However, in general, W _M >> wc,
S ≒ f _M
It becomes. Therefore, the above equation (1) is
θc≈2 tan ⁻¹ (wc / 2f _M )
You may think.
Therefore, in the case of θc = θ _M,
θ _M ≈ 2 tan ^-1 (wc / 2f _M )
It becomes. Therefore, f _M is expressed as follows.
f _M = wc / 2 tan (θ _M / 2) (2)
That is, if wc and θ _M are known, f _M can be obtained from the above equation (2).

(4. Shooting operation)
Next, an actual photographing operation performed using the digital camera 1 will be described.
First, the viewing angle θ _M is set and input to the digital camera 1. This setting input is performed by operating the operation unit 45 (see FIG. 1) of the digital camera 1 and selecting an item corresponding to the view angle setting. Thus, the operation unit 45 functions as an angle-of-view setting unit that sets the viewing angle θ _M when viewing the display device (LCD 51 in the present embodiment).

  More specifically, FIG. 10 shows a state in which the LCD 51 is viewed through the viewfinder (the electronic viewfinder window 6 or the display unit 7 as an external viewfinder (monitor)) of the digital camera 1 at the viewing position of the LCD 51. . FIG. 11 shows the display screen of the display unit 7 when the upper and lower ends of the finder of the digital camera 1 and the upper and lower ends of the LCD 51 coincide with each other when the LCD 51 is viewed as described above. On this display screen, a focal length display window 60 indicating the focal length of the photographing lens 31 is displayed. In the focal length display window 60, a bar 61 is displayed at a position corresponding to the focal length of the current photographing lens 31.

  Although the aspect ratio of the screen of the display unit 7 is 3: 4, the aspect ratio of the screen 51a of the LCD 51 is 9:16, and the horizontal length of the screen 51a of the LCD 51 is as shown in FIG. Longer than the horizontal length. Therefore, in the present embodiment, as described above, zoom adjustment is performed with the zoom lever 10 so that all the captured images of the digital camera 1 can be confirmed on the LCD 51, and the vertical dimension (upper and lower ends) of the screen 51a is displayed on the display unit 7. To match the vertical dimension (upper and lower ends). Note that if the entire captured image of the digital camera 1 can be displayed on the LCD 51, the horizontal dimension (left and right ends) of the screen 51a may be made to coincide with the horizontal dimension (left and right ends) of the display unit 7. .

Next, in this state, the operation key 11 and the selection button 9 of the digital camera 1 are operated to set and input the viewing angle θ _M. More specifically, when the button corresponding to the menu display (hereinafter referred to as the menu button) is pressed once among the operation keys 11, the contents of the “basic” menu shown in FIG. . When “Application 1” is selected on this display screen, the contents shown in FIG.

Then, when the “equal angle of view display mode” is selected on the display screen of “application 1”, four menus of “setting”, “photographing”, “display”, and “cancel” are displayed as shown in FIG. Therefore, “Setting” is selected. In this state, when a key corresponding to an execution button (hereinafter referred to as an execution button) among the operation keys 11 is pressed, the viewing angle when viewing the LCD 51 in the digital camera 1 at this time (relative to the digital camera 1) The angle at which both ends of the screen 51 a of the LCD 51 are stretched) is set as the viewing angle of view θ _M and stored in the storage unit 25.

In addition, since the length wc of the imaging area of the CCD 32 is known in advance for each digital camera 1, the control unit 24 performs the above-described operation based on the viewing angle θ _M and the length wc of the imaging area of the CCD 32. From the equation (2), the focal length f _M of the photographic lens 31 is calculated so that the viewing angle of view θ _M and the photographic angle of view θc are equal, and this focal length f _M is stored in the storage unit 25. a position corresponding to the focal length f _M a lower part of the focal length display window 60 displayed on the display unit 7 to display the index M1 as information of the focal length f _M.

The control unit 24 stores a plurality of focal lengths f _M of the photographing lens 31 corresponding to a plurality of viewing angles of view θ _M in the storage unit 25 and is below the focal length display window 60 of the display unit 7. A plurality of indices (for example, M1, M2, M3,...) As information on each focal length f _M may be displayed at positions corresponding to the plurality of focal lengths f _M (see FIG. 11).

When the viewing angle of view θ _M is set as described above, the photographer may shoot the subject using the digital camera 1 as follows.

First, the photographer displays the menu shown in FIG. 14 on the display unit 7 of the digital camera 1 by operating the operation key 11 and the selection button 9, selects “shoot” from the menu, and presses the execution button. Then, indicators M1, M2,... Corresponding to the preset focal length f _M of the photographing lens 31 are displayed on the right side of “shooting” (not shown). Therefore, the photographer selects an index (for example, M1) that matches the viewing position when viewing the LCD 51, and presses the execute button again.

Then, as shown in FIG. 15, the index M <b> 1 is displayed below the focal length display window 60 of the display unit 7. Accordingly, the photographer holds the digital camera 1 toward the subject and operates the zoom lever 10 (focal length change input means) to adjust the bar 61 to M1, thereby changing the focal length of the taking lens 31 to f _M. be performed for shooting, it is possible to photograph the subject with equal appreciation angle theta _M imaging angle .theta.c.

  If the image data of the photographed image is output to the LCD 51 via the communication I / F 43 (output means), the viewer can perform the process on the LCD 51 with the same angle of view as that at the time of photographing without performing any special processing. The displayed image can be viewed.

  If the focal length display window 60 and a plurality of indices (M1, M2,...) Are displayed on the display unit 7 together with the photographed image, the display image can be viewed at any display device or viewing position at the time of photographing. You can see at a glance whether you can watch at the same angle of view.

As described above, the digital camera 1 of this embodiment, focal length control means (focusing control circuit 38, a zoom drive control circuit 39, the control unit 24), imaging angle θc is equal to the viewing angle theta _M In this way, the focal length of the photographic lens 31 is changed to f _M. As a result, if the photographer shoots with the digital camera 1 at the changed focal length f _M , the subject can be photographed at the photographing field angle θc equal to the viewing angle θ _M.

Then, when image data of an image captured by the digital camera 1 is transmitted to the LCD 51 and the LCD 51 displays a captured image based on the image data, the viewer is equal to the angle of view at the time of shooting (shooting angle of view θc). The photographed image can be viewed at the angle of view (viewing angle of view θ _M ), and the photographed image can be viewed in a way that looks close to nature. Therefore, it is not necessary to perform any special processing or operation on the display device side as in the prior art, and a captured image can be viewed with a natural appearance even in a display device other than the projection type display device. That is, according to the present invention, versatility can be imparted to a display device other than the projection display device.

The focal length control means, based on the length wc Appreciation angle theta _M of the imaging area of the CCD 32, the focal length f of the imaging lens 31, such as shooting angle θc is equal to the viewing angle theta _{M Since M} is calculated, the focal length f _M can be obtained with certainty.

Further, the digital camera 1 has a communication I / F 43 that outputs image data of a subject image taken at a photographing angle of view θc equal to the viewing angle of view θ _M to the LCD 51. The image data is reliably supplied from the communication I / F 43 to the LCD 51, and the viewer can view the captured image at the same angle of view as when the image is taken without performing any special processing or operation on the LCD 51 side. .

Further, in the present embodiment, the focus of the taking lens 31 when the focal length control means (focusing control circuit 38, a zoom drive control circuit 39, the control unit 24), the imaging angle θc is equal to the viewing angle theta _M causes display information of the distance f _M (e.g. M1) to the display unit 7, based on the instruction input by the photographer of the zoom lever 10 (focal length change input means) to change the focal length of the taking lens 31. Thus, if the photographer operates the zoom lever 10 based on the information displayed on the display unit 7 and inputs an instruction to change the focal length of the photographing lens 31 to f _M , the focal length control means captures the image. the focal length of the lens 31 is changed to f _M. Therefore, by performing the photographer captured by the digital camera 1 in this state, it is possible to photograph the subject with equal appreciation angle theta _M imaging angle .theta.c.

By the way, in this embodiment, when the focal length control means changes the focal length of the photographic lens 31, the case where the photographer waits for an instruction by manual operation of the zoom lever 10 is described, but such an instruction is awaited. It is also possible to perform this automatically. That is, the focal length control means, based on the length wc Appreciation angle theta _M of the imaging area of the CCD 32, the focal length f _M of the taking lens 31 as shooting angle θc is equal to the viewing angle theta _M May be calculated and changed to that. In this case, since the photographer's instruction input by the zoom lever 10 for adjusting the focal length of the photographing lens 31 to f _M can be omitted, the convenience of the digital camera 1 can be improved.

Note that the digital camera 1 of the present embodiment has a focus so that the shooting angle of view θc is equal to the viewing angle of view θ _M even when the focal length of the shooting lens 31 is changed automatically or manually. There is no change in the configuration in which the distance control means changes the focal length of the photographic lens 31.

  Note that the present invention can be applied not only to the case where the focal length of the photographic lens 31 is changed using the optical zoom as in the present embodiment, but also to the case where the focal length of the photographic lens 31 is simulated using the electronic zoom.

[Embodiment 2]
The following will describe another embodiment of the present invention with reference to the drawings. For convenience of explanation, the same components as those in the first embodiment are denoted by the same member numbers, and the description thereof is omitted.

In the first embodiment described above, the setting of the viewing angle θ _M is input to the digital camera 1 in advance, and the zoom operation is performed manually or automatically so that an image suitable for the viewing monitor can be taken at the time of shooting. Yes. The image is taken after the focal length of the photographic lens 31 is moved to a desired focal length f _M , and an image with an viewing angle of view θ _M equal to the photographic angle of view θc is displayed on the LCD 51.

On the other hand, in the present embodiment, an image having a shooting angle of view θc equal to the viewing angle of view θ _M is obtained by scaling (enlarging or reducing) an image already shot at various focal lengths of the shooting lens 31. It is generated and displayed on the LCD 51. Hereinafter, first, how to set the enlargement / reduction display magnification will be described.

FIG. 16 is an explanatory diagram schematically showing the positional relationship between the viewer of the LCD 51 and the LCD 51. Here, θ _M is an angle at which the upper and lower ends of the screen 51a of the LCD 51 are stretched with respect to the viewer. In the present embodiment, θ _M is considered as the viewing angle of view. Further, .theta.w shows a photographing field angle of the image captured by the wide-angle side than equal viewing angle theta _M photographing field angle .theta.c, theta _T is telephoto than equal viewing angle theta _M imaging angle .theta.c The shooting angle of view of the image shot on the side is shown. H _M indicates the vertical dimension of the screen 51a of the LCD 51.

On the other hand, FIG. 17 is an explanatory diagram schematically showing the relationship between the photographing field angle θ of the CCD 32 of the digital camera 1 and the focal length f. The focal length of the taking lens 31 when the shooting angle of view is θw is fw, and the focal length of the taking lens 31 when the shooting angle of view is θ _T is f _T. The focal length of the taking lens 31 when the viewing angle of view θ _M is equal to the shooting angle of view θc is f _M.

The image photographed by the photographing field angle .theta.w the wide angle side than equal viewing angle theta _M shooting angle .theta.c, if viewing angle is to be displayed on the LCD 51 so as to be equal to the shooting angle .theta.w, LCD 51 screen 51a As for the vertical dimension, only Hw is originally required. Therefore, if the digital camera 1 side cuts out a portion of the captured image that is an image having a shooting angle of view θc equal to the viewing angle of view θ _M and enlarges the cut image by a ratio K = Hw / H _M , When the image is displayed on the LCD 51 based on the image data of the image, the image can be displayed in a full screen 51a of the LCD 51.

Here, the enlargement ratio K on the digital camera 1 side can be obtained as follows.
If the distance between the viewer and the LCD 51 is L,
tan (θw / 2) = Hw / 2L
tan (θ _M / 2) = H _M / 2L
Therefore,
Hw = 2Ltan (θw / 2)
H _M = 2Ltan (θ _M / 2)
Therefore, the enlargement ratio K is
K = Hw / H _M
= 2L (tan (θw / 2)) / 2L (tan (θ _M / 2))
= (Tan (θw / 2)) / (tan (θ _M / 2)) (3)
It becomes.

The length of the imaging area of the CCD 32 (the length in the vertical direction in this case) as compared with wc, assuming the dimension H _M or shooting subject screen 51a of LCD51 is sufficiently large, on the basis of the following equation The shooting angle of view at the time of shooting can be obtained only by the focal length f at the time of shooting and the length wc of the imaging area of the CCD 32.
tan (θw / 2) = wc / 2fw
tan (θ _M / 2) = wc / 2f _M
If these are substituted into the above equation (3), the enlargement ratio K is expressed as follows.
K = (wc / 2fw) / (wc / 2f _M )
= F _M / fw (4)
That is, the enlargement ratio K can be obtained only from the focal lengths f _M and fw.

On the other hand, in the case where an image shot at a shooting angle of view θ _T on the telephoto side from the shooting angle of view θc equal to the viewing angle of view θ _M is displayed on the LCD 51 so that the viewing angle of view becomes equal to the shooting angle of view θ _T , vertical dimension of the screen 51a of the LCD51 is sufficient in less than H _M dimension H _T. Therefore, if the captured image is reduced by the ratio K = H _T / H _M on the digital camera 1 side, when the image is displayed on the LCD 51 based on the image data of this image, it is equal to the viewing angle θ _M. An image with a shooting angle of view can be displayed on the screen 51 a of the LCD 51. Note that an area corresponding to the difference between the image before reduction (original image) and the image after reduction is blacked out in this embodiment (a pixel area having black image data).

Here, the reduction ratio K on the digital camera 1 side can be obtained as follows.
If the distance between the viewer and the LCD 51 is L,
tan (θ _T / 2) = H _T / 2L
tan (θ _M / 2) = H _M / 2L
Therefore,
H _T = 2Ltan (θ _T / 2)
H _M = 2Ltan (θ _M / 2)
Therefore, the reduction ratio K is
K = H _T / H _M
= 2L (tan (θ _T / 2)) / 2L (tan (θ _M / 2))
= (Tan (θ _T / 2)) / (tan (θ _M / 2)) (5)
It becomes.

The length of the imaging area of the CCD 32 (the length in the vertical direction in this case) as compared with wc, assuming the dimension H _M or shooting subject screen 51a of LCD51 is sufficiently large, on the basis of the following equation The shooting angle of view at the time of shooting can be obtained only by the focal length f at the time of shooting and the length wc of the imaging area of the CCD 32.
tan (θ _T / 2) = wc / 2f _T
tan (θ _M / 2) = wc / 2f _M
If these are substituted into the above equation (5), the reduction ratio K is expressed as follows.
K = (wc / 2f _T ) / (wc / 2f _M )
= F _M / f _T (6)
That is, the reduction ratio K can be obtained only by information on the focal lengths f _M and f _T.

In the present embodiment, the focal length (for example, fw or f _T ) of the photographing lens 31 when the subject is photographed is stored in the storage unit 25 as the first focal length, and the photographing field angle θc that is the same as the viewing angle θ _M. The focal length f _M of the photographic lens 31 is stored in the storage unit 25 as the second focal length. Therefore, in the present embodiment, the storage unit 25 functions as a focal length storage unit that stores the first focal length and the second focal length.

Next, an operation method of the digital camera 1 will be described. In this embodiment, the viewing angle θ _M corresponding to the viewing position of the LCD 51 is already set and input by the field angle setting means (operation unit 45) and stored in the storage unit 25 by the same method as in the first embodiment. It is assumed that

First, the user of the digital camera 1 (which may be different from the photographer) causes the display unit 7 of the digital camera 1 to display the menu shown in FIG. Select "Display" from the menu and press the execution button. Then, indicators M1, M2,... Corresponding to the preset focal length f _M of the photographing lens 31 are displayed on the right side of “display” (not shown). Therefore, the user selects an index (for example, M1) that matches the viewing position when viewing the LCD 51, and presses the execute button again.

Figure 18 is displayed on the display unit 7 the image photographed by the photographing field angle θw of the wide-angle side than equal photographing field angle θc Appreciation angle theta _M. The focal length fw of the photographic lens 31 at this time is indicated by a bar 61. Next, the user operates the zoom lever 10 to move the bar 61 to the position of the index M1. Then, the control unit 24 cuts out a part of the image before zooming shown in FIG. 18 (hereinafter referred to as an image 71). The image 71 at this time is an image in which the shooting angle of view θc is equal to the viewing angle of view θ _M among the shot images. The range of the image 71 can be freely selected by operating the operation unit 45. For example, the range of the image 72 indicated by a broken line can be selected.

Next, based on the first focal length (here, the focal length fw) and the second focal length (focal length f _M ) stored in the storage unit 25, the control unit 24 indicates the above equation (4). The zoom ratio (enlargement ratio K) of the subject image is calculated. Then, the control unit 24 enlarges the cut-out image 71 at the zoom ratio. As a result, the image 71 is enlarged and displayed on the display screen of the display unit 7 as shown in FIG. The image data of the enlarged image 71 is output to the LCD 51 via the communication I / F 43 (output means).

On the other hand, FIG. 20 is displayed on the display unit 7 the image photographed by the photographing field angle theta _T on the telephoto side than the equal viewing angle theta _M imaging angle .theta.c. The focal length f _T of the photographing lens 31 at this time is indicated by a bar 61. The user operates the zoom lever 10 to move the bar 61 to the position of the index M1. Then, the control unit 24 reduces the entire range of the display image shown in FIG. This reduction process is performed by the control unit 24 based on the first focal length (here, the focal length f _T ) and the second focal length (focal length f _M ) stored in the storage unit 25. This is done by calculating the magnification ratio (reduction ratio K) of the subject image shown in FIG.

  By such a reduction process, an image 73 obtained by reducing the original image is displayed on the display screen of the display unit 7 as shown in FIG. Note that portions other than the reduced image are blacked out. The image data of the image displayed on the display unit 7 including the image 73 is output to the LCD 51 via the communication I / F 43 (output means). A hatched area 51b in FIG. 16 indicates the display range of the reduced image 73 shown in FIG.

As described above, in the digital camera 1 of the present embodiment, the control unit 24 as the image scaling unit can obtain an image with the same shooting field angle θc as the viewing angle θ _M set and input by the field angle setting unit. In this way, the captured image (subject image) is enlarged or reduced. By the scaling process in the control unit 24 as described above, an image having the same shooting angle of view θc as the viewing angle of view θ _M can be obtained from an already shot image. As a result, when the image data is transmitted to the LCD 51 and the LCD 51 displays an image based on the image data, the viewer can view the captured image at the viewing angle θ _M equal to the shooting field angle θc. It is possible to view the photographed image with a natural appearance. In other words, even if the image has already been taken at different photographing field angle θc Appreciation angle theta _M, to obtain an image to be equal photographing field angle θc Appreciation angle theta _M from the captured image in the digital camera 1 Can do.

Therefore, in order to obtain an image to be equal photographing field angle θc Appreciation angle theta _M, it is not necessary to perform any special processing or operation on the display device side. As a result, any display device that performs display based on digital image data (any display device other than a projection display device) can view a captured image with a natural appearance. An effect similar to that of the first embodiment can be obtained.

The control unit 24 serving as an image scaling unit calculates a magnification ratio of the subject image based on the first focal length and the second focal length stored in the storage unit 25, and the subject image is calculated using the magnification ratio. enlarged or so to reduce the image after scaling processing is equivalent to that taken at the same shooting angle θc appreciation angle theta _M. Accordingly, when the image data after the scaling process is transmitted to the LCD 51 and the LCD 51 displays an image based on the image data, the viewer can surely view the captured image at the same viewing angle θ _M as the shooting angle θc. It is possible to view the captured image with a natural appearance.

In the present embodiment, the image data of the subject image enlarged or reduced by the control unit 24 is output to the display device from the communication I / F 43 serving as the output unit, and thus display is performed based on the image data. Even if the display device does not perform any special image processing (for example, enlargement / reduction processing), the viewer can view the captured image at the same viewing angle of view θ _M as the shooting angle of view θc on the display device.

  In this embodiment, the image scaling unit performs the scaling process after waiting for an instruction by the user's operation of the zoom lever 10, but the scaling process is automatically performed without waiting for such an instruction. May be.

[Embodiment 3]
The following will describe still another embodiment of the present invention with reference to the drawings. For convenience of explanation, the same members as those in the first or second embodiment are denoted by the same member numbers, and the explanation thereof is omitted.

  For example, when a child's face is photographed as a subject, and the image is viewed with a small print, it is common to zoom in relatively large to enlarge the face. However, when the subject image (the child's face) is viewed on the large-screen LCD 51, if the image is displayed as it is, the child's face may become unnaturally large and the viewer may feel uncomfortable. In such a case, if the child's face is displayed on the LCD 51 in actual size, the viewer can appreciate the subject with a natural feeling. Similarly, when the craft and artwork smaller than the monitor size are the subject, if the subject is displayed in actual size, the viewer may feel the real feeling.

  In view of the above points, in the present embodiment, the viewer is photographed by changing the focal length of the photographing lens 31 so that the photographed image can be displayed on the LCD 51 in actual size (same size). Is able to appreciate the captured images with a natural appearance. Hereinafter, the principle for displaying the photographed subject image on the LCD 51 in actual size will be described.

FIG. 22 is an explanatory diagram schematically showing the positional relationship among the LCD 51, the subject, and the digital camera 1. Assume that the digital camera 1 is placed at a position separated from the LCD 51 by a distance D _M from the viewing position. If the vertical dimension of the LCD 51 screen 51a and the H _M, the angle theta _M the upper and lower ends and the digital camera 1 is formed on the screen 51a longitudinal angle when viewing the LCD 51, that is, the viewing angle.

Assume that the subject at a distance D from the digital camera 1 is in focus, and the shooting angle of view of the shooting lens 31 at this time is θ _E. In order to photograph this subject with the digital camera 1 and display the photographed image on the LCD 51 in full size, the vertical dimension of the range shown on the virtual screen set at the distance D is the vertical dimension of the screen 51a of the LCD 51. is that equal to the dimension H _M. This, in other words, the distance photographing field angle theta _M becomes in D _M, moreover, as the distance and the imaging magnification beta _E of the photographing magnification beta _M and the distance D in the D _M is equal, the taking lens 31 That is, it is sufficient to set the focal length. Incidentally, imaging magnification beta _M are those represented by the ratio of the dimension H _M and the length of the imaging area of the CCD 32 (wherein the longitudinal length) wc, photographing magnification beta _E has a vertical dimension of an object This is indicated by a ratio to the length (here, the length in the vertical direction) wc of the imaging region of the CCD 32.

This will be described in more detail with reference to FIG. When the focal length of the photographing lens 31 when the LCD 51 is in focus is f _M and the focal length of the photographing lens 31 at the time of subject photographing is f _E ,
D _M = f _M (1 + 1 / β _M ) (7)
D = F _E (1 + 1 / β _E ) (8)
The relationship holds. Since β _M = β _E now,
f _E = f _M · (D / D _M ) (9)
It becomes. Therefore, if the data of f _M and D _M are known in advance and the distance D is obtained at the time of photographing, the focal length f _E of the photographing lens 31 capable of photographing at the same magnification is obtained by the above equation (9). Can do. That is, if the photographing lens 31 is set to the focal length f _E and photographed, when the photographed image is displayed on the screen 51a of the LCD 51, the viewer can appreciate the full-size (same size) subject image.

Next, a specific photographing method using the digital camera 1 will be described. The length wc of the image capturing region of the longitudinal dimension H _M and CCD32 screen 51a of LCD51 is assumed known in advance.

  First, in the same manner as in the first embodiment, the photographer performs zoom adjustment with the zoom lever 10 so that all the images captured by the digital camera 1 can be confirmed on the LCD 51, and sets the vertical dimension (upper and lower ends) of the screen 51a. It is made to correspond to the vertical dimension (upper and lower ends) of the display part 7 (refer FIG. 10, FIG. 11). Subsequently, the photographer operates the operation key 11 and the selection button 9 of the digital camera 1 to display the menu screen shown in FIG. 24 on the display unit 7, and selects “Application 1” on this display screen. “Equal magnification display mode” shown in FIG. 25 is selected. Then, as shown in FIG. 26, four menus of “SETTING”, “SHOOTING”, “DISPLAY”, and “RELEASE” are displayed on the display unit 7, and “SETTING” is selected.

In this state, the photographer presses the execution button in the operation key 11 to input the viewing angle θ _M at this time, and the focal length f of the photographing lens 31 determined based on the viewing angle θ _{M. M} and the distance D _M between the LCD 51 and the digital camera 1 are set and inputted. Note that a plurality of focal lengths f _M and distances D _M may be set and input in accordance with the viewing position of the LCD 51. The focal length f _M and the distance D _M are stored in the storage unit 25. At this time, the focal length f _M is stored in association with an index (for example, M1, M2, M3...) Corresponding to the viewing position of the LCD 51.

At the time of shooting, the photographer displays the menu screen shown in FIG. 26, selects “shoot” from the menu screen, and presses the execute button. Then, although not shown, since the information (index) of the already set focal lengths of M1 to M3 is displayed on the right side of “shooting” on the display screen of the display unit 7, the photographer can The focal length f _M (for example, index M1) corresponding to the current viewing position of the LCD 51 is selected, and the execution button is pressed again.

After the focal length f _M is set in this way, when the photographer focuses on the subject to be photographed, the distance D between the subject and the digital camera 1 can be known. Thus, the focal length f _E is calculated, and the index M1 is displayed at a position corresponding to the focal length f _E in the focal length display window 60 of the display unit 7 as shown in FIG. The photographer operates the zoom lever 10 (focal length change input means) so that the bar 61 matches the index M1, and changes the focal length of the photographing lens 31 to f _E , and shoots the subject in this state. . The image data of the photographed image is output to the LCD 51 via the communication I / F 43 (output means).

As described above, in the digital camera 1 of the present embodiment, the focal length control means (the focus adjustment control circuit 38, the zoom drive control circuit 39, and the control unit 24) is displayed on the LCD 51 based on the image data of the captured image. In this configuration, the focal length of the photographic lens 31 is changed to f _E so that the size of the subject image is the same as that of the actual subject. As a result, when the photographer shoots with the digital camera 1 at the changed focal length f _E and the LCD 51 displays the photographed image based on the image data at this time, the viewer views the photographed image at the same magnification as the subject. You can watch at. That is, the viewer can view the captured image with a natural appearance without performing any special processing or operation on the display device side.

Further, the focal length control means applies to the LCD 51 based on the distance D _M obtained based on the viewing angle of view θ _M and the focal length f _{M at} that time and the distance D obtained when the subject is focused. since calculates the focal length f _E of the imaging lens 31, such as size of the object image displayed is the same size as the actual object, it is possible to reliably obtain the focal length f _E.

Further, since the digital camera 1 has a communication I / F 43 that outputs image data of a subject image taken at a focal length f _E to the LCD 51, the image data is transmitted via the communication I / F 43. The viewer is surely supplied to the LCD 51, and the viewer can view the subject image at the same magnification without performing any special processing or operation on the LCD 51 side.

Further, in the present embodiment, the focal length control means (the focus adjustment control circuit 38, the zoom drive control circuit 39, and the control unit 24) actually determines the size of the subject image displayed on the LCD 51 based on the image data of the photographed image. Information on the focal length f _E of the photographic lens 31 when it is the same size as the subject is displayed on the display unit 7 and the focal length of the photographic lens 31 based on the input of the focal length change input means (zoom lever 10). Has changed. When the photographer operates the zoom lever 10 based on the information displayed on the display unit 7 and inputs an instruction to change the focal length of the photographic lens 31 to f _E , the focal length control means causes the focal point of the photographic lens 31. Since the distance is changed to f _E , the photographer takes a picture with the digital camera 1 in this state, and when the LCD 51 displays the photographed image based on the image data at this time, the viewer recognizes the photographed image as a subject, etc. You can appreciate at double.

Further, since the information on the focal length f _E is displayed on the display unit 7, the photographer changes the focal length of the photographing lens by the focal length change input unit based on the information displayed on the display unit 7. Instructions can be input easily.

In the above, the case where the focal length of the photographing lens 31 is changed after waiting for an instruction by manual operation of the photographer's zoom lever 10 has been described. However, the focal length control means automatically performs this. Also good. In this case, since the photographer's instruction input by the zoom lever 10 for adjusting the focal length of the photographing lens 31 to f _E can be omitted, the convenience of the digital camera 1 can be improved.

[Embodiment 4]
The following will describe still another embodiment of the present invention with reference to the drawings. For convenience of explanation, the same members as those in the first or second embodiment are denoted by the same member numbers, and the explanation thereof is omitted.

  In the above-described third embodiment, the digital camera 1 is set in the same magnification shooting in advance, and the zoom operation is performed automatically or manually so that an image suitable for the viewing monitor (LCD 51) can be shot during shooting. The lens 31 can be photographed after changing the focal length to a desired focal length. On the other hand, in the present embodiment, an image captured at various magnifications is subjected to scaling processing (enlargement or reduction) so that the subject can be viewed at the same magnification as that at the time of photographing.

First, a method for setting the magnification in the scaling process of this embodiment will be described.
FIG. 28 is an explanatory diagram schematically showing the positional relationship among the LCD 51, the subject, and the digital camera 1. Here, θ _E indicates a shooting angle of view for displaying the subject image shot at the distance D at the same magnification on the screen 51a of the LCD 51. In FIG. 28, the same reference numerals as those in FIG. 22 are the same as those described in the third embodiment unless otherwise specified.

Now, let θ _DW be the angle of view of an image shot at a wide angle side than θ _E , and let H _{DW be the} upper and lower dimensions of the shooting screen on the virtual screen placed at the position of distance D. . When an image shot at the shooting angle of view θ _DW is displayed on the LCD 51, this image is reduced and displayed by the ratio H _M / H _DW . Therefore, in order to display this image at the same magnification, it is only necessary to enlarge the original image by the inverse ratio H _DW / H _M.

On the other hand, the shooting angle of view of the image shot at the telephoto side with respect to θ _E is θ _DT, and the upper and lower end dimensions of the shooting screen on the screen placed at the distance D are H _DT . When an image shot at the shooting angle of view θ _DT is displayed on the LCD 51, this image is enlarged and displayed by the ratio H _M / H _DT . Therefore, in order to display this image at the same magnification, it is only necessary to reduce the original image by the inverse ratio H _DT / H _M.

  Here, the magnification ratio (enlargement ratio or reduction ratio) K of the image can be derived as follows.

When the shooting angle of view at the time of shooting is θ _D and the upper and lower end dimensions of the shooting screen on the virtual screen placed at the shooting distance D are H _D ,
tan (θ _D / 2) = (H _D / 2) / D
tan (θ _E / 2) = (H _M / 2) / D
More, H _D and H _M is expressed as follows.
H _D = 2D tan (θ _D / 2)
H _M = 2Dtan (θ _E / 2)
Therefore, the ratio K is expressed as follows.
K = H _D / H _M
= (Tan (θ _D / 2)) / (tan (θ _E / 2)) (10)

on the other hand,
D · tan (θ _E / 2) = D _M · tan (θ _M / 2)
Than,
tan (θ _E / 2) = (D _M / D) · tan (θ _M / 2)
Therefore, the ratio K in the equation (10) is expressed as follows.
K = (D / D _M ) · (tan (θ _D / 2)) / (tan (θ _M / 2))
(11)

Further, the focal length of the taking lens 31 when taken with the camera can focus on subjects and f _D, the focal length of the taking lens 31 when the focus on LCD51 in viewing position of the LCD51 and f _M,
tan (θ _D / 2) = (wc / 2) / (f _D (1 + β _D ))
tan (θ _M / 2) = (wc / 2) / (f _M (1 + β _M ))
However,
β _D = wc / H _D (12)
β _M = wc / H _M (13)
By substituting these equations into the equation (11), the ratio K is expressed as follows.
K = (D / D _M ) · (f _M (1 + β _M )) / (f _D (1 + β _D ))
(14)
The magnifications β _D and β _M can be expressed as follows.
β _D = f _D / (D−f _D )
β _M = f _M / (D−f _M )

Now, in comparison with the length (effective pixel size) wc of the imaging area of the CCD 32, when the dimension H _M of the screen 51a of the LCD51 is sufficiently large, than the number (12) and the number (13), beta _D = beta Since it can be considered that _M = 0, the expression (14) can be considered to be expressed as follows.
K = (D / D _M ) · (f _M / f _D ) (15)
In this way, it is possible to derive the magnification ratio K of the photographed image that can be displayed on the LCD 51 at the same magnification.

Next, an operation method of the digital camera 1 will be described. In the present embodiment, the viewing angle θ _M corresponding to the viewing position of the LCD 51 is already set and input by the field angle setting means (operation unit 45) by the same method as in the third embodiment, and the viewing angle θ _M Stored in the storage unit 25 are the distance D _M and the focal distance f _M obtained based on the subject, the subject distance (distance D) when the subject is focused and photographed, and the focal distance f _{D at} that time. And

First, the user of the digital camera 1 (which may be different from the photographer) causes the display unit 7 of the digital camera 1 to display the menu shown in FIG. Select "Display" from the menu and press the execution button. Then, indicators M1, M2,... Corresponding to the preset focal length f _M of the photographing lens 31 are displayed on the right side of “display” (not shown). Therefore, the user selects an index (for example, M1) that matches the viewing position when viewing the LCD 51, and presses the execute button again.

Here, FIG. 29 shows a display screen of the display unit 7 that displays an image shot at a shooting angle of view θ _D wider than θ _E (that is, θ _D > θ _E ). Bar is displayed on the focal length display window 60 61 is obtained by reading and displaying the focal length f _D at the time of photographing stored in the image.

  In this state, the user operates the zoom lever 10 to adjust the bar 61 to the position of the index M1. Then, the control unit 24 cuts out a part of the image before zooming shown in FIG. 29 (hereinafter referred to as an image 81). The image 81 at this time corresponds to a portion displayed on the LCD 51 at the same magnification. The range of the image 81 can be freely selected (changed in position) by operating the operation unit 45. Further, portions other than the image 81 are removed.

  Then, the control unit 24 calculates a magnification ratio (here, an enlargement ratio) K based on the above equation (15), and enlarges the image 81 with this ratio K. Then, the image 81 shown in FIG. 29 is enlarged and displayed on the full screen of the display unit 7. The image data of the image after the enlargement process is output to the LCD 51 via the communication I / F 43 (output means).

On the other hand, FIG. 30 shows a display screen of the display unit 7 to imaging angle theta _D views a photographed image on the telephoto side (i.e. θ _D <θ _E) than theta _E. In this captured image, the bar 61 displayed in the focal length display window 60 is initially displayed on the telephoto side with respect to the index M1. When the user operates the zoom lever 10 to adjust the bar 61 to the position of the index M1, the control unit 24 calculates the zoom ratio (here, the reduction ratio) K based on the above equation (15). The image is reduced at this ratio K. An image 82 shows an image reduced in this way. A portion corresponding to the difference between the image before reduction and the image 82 after reduction is blacked out. The image data of the image including the image 82 displayed on the display unit 7 is output to the LCD 51 via the communication I / F 43 (output means).

  As described above, in the digital camera 1 of the present embodiment, the control unit 24 as the image scaling unit has the same size as the actual subject on the subject image displayed on the LCD 51 based on the image data. In this way, the captured subject image is enlarged or reduced. As a result, an image that can be displayed at the same magnification on the LCD 51 can be obtained from the already photographed image. Therefore, when the image data is transmitted to the LCD 51 and the LCD 51 displays an image based on the image data. In addition, the viewer can view the subject image at the same magnification, and can view the subject image in a manner close to nature.

  That is, image data that can be displayed at the same magnification is generated on the digital camera 1 side, so that no special processing or operation is required on the display device side. Therefore, according to the configuration of the present embodiment, any display device (even a display device other than a projection display device) can display a captured image naturally as long as the display device performs display based on digital image data. You can appreciate it in a close view.

The control unit 24 also uses the LCD 51 based on the distance D _M and the focal distance f _M obtained based on the viewing angle θ _M and the distance D and the focal distance f _D obtained when the subject is focused. The magnification ratio expressed by Equation (15) is calculated so that the size of the subject image displayed on the screen is the same as that of the actual subject, and the photographed subject image is enlarged or reduced by that ratio. ing. As a result, image data of an image that can be displayed at the same magnification on the LCD 51 can be reliably generated, and an image that can be displayed at the same magnification can be reliably obtained by scaling the original image at the ratio. Can do.

  In this embodiment, the control unit 24 performs the scaling process after waiting for an instruction by the user's operation of the zoom lever 10, but the scaling process is automatically performed without waiting for such an instruction. Also good.

It is a block diagram which shows the detailed structure inside the digital camera which concerns on one Embodiment of this invention. It is a perspective view which shows the external appearance structure of the said digital camera. It is a rear view of the digital camera. It is explanatory drawing which shows a mode that the photographer image | photographs scenery using the said digital camera. It is explanatory drawing which shows the image obtained with the said digital camera when the said scenery is image | photographed by the wide angle side. It is explanatory drawing which shows the image obtained with the said digital camera when the said scenery is image | photographed on the telephoto side. It is explanatory drawing which shows the positional relationship of the wall-mounted display apparatus installed in the home, and the viewer who appreciates it. It is a top view which shows typically the positional relationship of the said display apparatus and viewer. It is a top view which shows typically the positional relationship of the imaging lens and CCD of the said digital camera used at the time of object imaging | photography. It is explanatory drawing which shows a mode that the photographer is looking at the said display apparatus through the finder of the said digital camera in the appreciation position of the said display apparatus. FIG. 3 is an explanatory diagram showing a display screen of a display unit when the upper and lower ends of the finder of the digital camera 1 coincide with the upper and lower ends of the display device when the display device is viewed with the digital camera. It is explanatory drawing which shows the menu displayed on the display screen of the said display part. It is explanatory drawing which shows the other menu displayed on the display screen of the said display part. It is explanatory drawing which shows the further another menu displayed on the display screen of the said display part. It is explanatory drawing which shows the example of a display of the display screen of the said display part. It is explanatory drawing which shows typically the positional relationship of the viewer of the display apparatus which displays the picked-up image of the digital camera which concerns on other embodiment of this invention, and the display apparatus. It is explanatory drawing which shows typically the relationship between the imaging | photography field angle of CCD of the said digital camera, and a focal distance. It is explanatory drawing which shows the display screen of the display part on which the image image | photographed with the imaging | photography angle of view wider than the imaging | photography angle of view equal to the viewing angle of view was displayed. It is explanatory drawing which shows the display screen of the display part by which the said image was expandedly displayed. It is explanatory drawing which shows the display screen of the display part on which the image image | photographed with the imaging | photography angle of view more telephoto than the imaging | photography angle of view equal to an appreciation angle of view is displayed. It is explanatory drawing which shows the display screen of the display part by which the said image was reduced-displayed. It is explanatory drawing which shows typically the positional relationship of the digital camera which concerns on other embodiment of this invention, a display apparatus, and a to-be-photographed object. It is explanatory drawing which shows typically the positional relationship of CCD and the imaging lens of the said digital camera. It is explanatory drawing which shows the menu displayed on the display screen of the display part of the said digital camera. It is explanatory drawing which shows the other menu displayed on the display screen of the said display part. It is explanatory drawing which shows the further another menu displayed on the display screen of the said display part. It is explanatory drawing which shows the example of a display of the display screen of the said display part. It is explanatory drawing which shows typically the positional relationship of the digital camera which concerns on other embodiment of this invention, a display apparatus, and a to-be-photographed object. It is explanatory drawing which shows the display screen of the display part on which the image image | photographed with the wide angle was displayed. It is explanatory drawing which shows the display screen of the display part on which the image image | photographed with telephoto was displayed.

Explanation of symbols

1 Digital camera 24 Control unit (focal length control means, image scaling means)
25 storage unit (focal length storage means)
31 Shooting lens 32 CCD (Image sensor)
38 Focus adjustment control circuit (focal length control means)
39 Zoom drive control circuit (focal length control means)
43 Communication I / F (output means)
45 Operation section (view angle setting means)

Claims (11)

A digital camera that takes a subject image by exposing an image sensor,
A photographic lens for forming the subject image on the image sensor;
Focal length control means for controlling the focal length of the photographing lens;
An angle of view setting means for setting an angle of view for viewing the display device,
The digital camera according to claim 1, wherein the focal length control means changes a focal length of the photographing lens so that a photographing field angle becomes equal to the viewing angle.   The focal length control means calculates a focal length of the photographing lens such that a photographing field angle becomes equal to the viewing angle based on the length of the imaging region of the image sensor and the viewing angle, and changes the focal length. The digital camera according to claim 1, wherein:   3. The digital camera according to claim 1, further comprising output means for outputting image data of a subject image photographed at a photographing angle of view equal to the viewing angle of view to the display device. A digital camera that takes a subject image by exposing an image sensor,
An image scaling means for enlarging or reducing the photographed subject image;
An angle of view setting means for setting an angle of view for viewing the display device,
The digital camera characterized in that the image scaling means enlarges or reduces the subject image so that an image having the same shooting angle of view as the viewing angle of view can be obtained. A photographic lens for forming the subject image on the image sensor;
The focal length of the photographing lens when the subject is photographed is stored as the first focal length, and the focal length of the photographing lens having the same photographing angle of view as the viewing angle of view is stored as the second focal length. A distance storage means;
The image scaling unit calculates a scaling ratio of the subject image based on the first focal length and the second focal length, and enlarges or reduces the subject image by the scaling ratio. The digital camera according to claim 4.   6. The digital camera according to claim 4, further comprising output means for outputting image data of the subject image enlarged or reduced by the image scaling means to the display device. A digital camera that takes a subject image by exposing an image sensor,
A photographic lens for forming the subject image on the image sensor;
Focal length control means for controlling the focal length of the photographing lens;
Output means for outputting image data of the subject image obtained by photographing to a display device;
The focal length control means is configured to adjust the focal length of the photographing lens during photographing of the subject so that the size of the subject image displayed on the display device based on the image data is the same size as the actual subject. A digital camera characterized by changing. An angle-of-view setting means for setting an angle of view for viewing the display device;
The distance from the viewing position of the display device to the display device is D _M , the focal length of the taking lens when the display device is focused at the viewing position is f _M , and the distance from the camera to the subject is D Then,
The focal length control means is displayed on the display device based on the distance D _M and focal length f _M obtained based on the viewing angle of view and the distance D obtained when the subject is focused. 8. The digital camera according to claim 7, wherein the focal length of the taking lens is calculated so that the size of the subject image is the same as that of the actual subject, and the focal length is changed. A digital camera that takes a subject image by exposing an image sensor,
An image scaling means for enlarging or reducing the photographed subject image;
Output means for outputting image data of the subject image to a display device,
The image scaling means enlarges or reduces the captured subject image so that the size of the subject image displayed on the display device is the same as the actual subject based on the image data. A featured digital camera. A photographic lens for forming the subject image on the image sensor;
An angle-of-view setting means for setting an angle of view for viewing the display device;
The distance from the viewing position of the display device to the display device is D _M , the focal length of the taking lens when the display device is focused at the viewing position is f _M , and the distance from the camera to the subject is D When the focal length of the photographic lens when the subject is in focus is f _D ,
The image scaling means displays the display based on the distance D _M and the focal distance f _M obtained based on the viewing angle of view, and the distance D and the focal distance f _D obtained when the subject is focused. 10. The zoom ratio is calculated such that the size of a subject image displayed on the apparatus is the same as that of an actual subject, and the photographed subject image is enlarged or reduced by that ratio. The digital camera described in 1.   When the display device is viewed through the viewfinder of the camera at the viewing position of the display device, the upper and lower ends or left and right ends of the viewfinder coincide with the upper and lower ends or left and right ends of the display device. 11. The digital camera according to claim 1, wherein a viewing angle of the camera when set is set as the viewing angle of view.

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