JP4061642B2 - Electronic camera - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electronic camera, and more particularly to an electronic camera having both an optical zoom function and an electronic zoom function.
[0002]
[Prior art]
The zoom lens has an advantage that the photographer can freely adjust the angle of view, but generally there is a problem that when zooming to the tele side, the F value increases and the lens becomes dark. For this reason, flash photography is required in dark scenes, etc., but even when using flash photography, if the subject is too far away, sufficient light cannot be obtained, resulting in a dark image. There is.
[0003]
In order to solve such a problem of the zoom lens, a silver salt camera that performs zooming by giving priority to the trimming zoom over the optical zoom in a dark situation where flash photography is necessary has been proposed (for example, Patent Document 1). When the camera is in a dark situation where flash photography is required, the camera zooms the lens to the wide end and photographs the trimming information on the film. Then, by performing trimming based on the trimming information written on the film at the time of printing, the same effect as that obtained by pseudo zoom photography is obtained.
[0004]
[Patent Document 1]
JP2000-310802
[0005]
[Problems to be solved by the invention]
Incidentally, the optical axis of a strobe provided in a camera is generally deviated from the optical axis of the photographing lens, and the amount of strobe light decreases as the distance from the optical axis increases.
[0006]
On the other hand, the conventional camera has a drawback that the strobe light emitted from the strobe cannot be used efficiently because it is trimmed around the optical axis of the photographing lens.
[0007]
The present invention has been made in view of such circumstances, and provides an electronic camera capable of performing zoom photography using a strobe light efficiently.
[0008]
[Means for Solving the Problems]
According to a first aspect of the present invention, in order to achieve the above object, a strobe light emitting unit that emits strobe light toward the subject, and an electronic device that cuts out a part of the image captured by the imaging unit and changes the magnification of the subject. A zoom unit, a zoom operation unit that gives an instruction to change the magnification of the subject, and a control unit that controls the electronic zoom unit based on an instruction from the zoom operation unit, and emits light from the strobe light unit during strobe light emission. There is provided an electronic camera comprising: control means for controlling the electronic zoom means so as to cut out an image around the optical axis of the strobe light.
[0009]
According to the present invention, at the time of strobe light emission, an electronic zoom is performed by cutting out an image around the optical axis of strobe light emitted from the strobe light emission means. Thereby, the strobe light emitted from the strobe light emitting means can be used efficiently, and a bright and good image can be obtained.
[0010]
In order to achieve the above object, the invention according to claim 2 includes an optical zoom unit that is controlled by the control unit and moves a part of the photographing lens to change the magnification of the subject. The control means changes the magnification of the subject with the electronic zoom means and then changes the magnification of the subject with the optical zoom means, and cuts out an image around the optical axis of the strobe light emitted from the strobe light emitting means. The electronic camera according to claim 1, wherein the electronic zoom unit is controlled as described above.
[0011]
According to the present invention, zooming is performed with priority on the electronic zoom when the flash is emitted. At this time, an electronic zoom is performed by cutting out an image around the optical axis of the strobe light emitted from the strobe light emitting means. Further, at the time of optical zoom, the position of the optical axis of the strobe light in the captured image is shifted according to the focal length, so that the center of the cutout range is corrected accordingly. Thereby, the strobe light emitted from the strobe light emitting means can be used efficiently, and a bright and good image can be obtained.
[0012]
According to a third aspect of the present invention, in order to achieve the above object, the control means changes the magnification of the subject with the optical zoom means based on an instruction from the zoom operation means when the strobe is not lighted. 3. The electronic camera according to claim 2, wherein the electronic zoom means cuts out an image around the optical axis of the photographing lens to change the magnification of the subject.
[0013]
According to the present invention, zooming is performed with priority given to the optical zoom when the strobe is not emitting light. Thereby, good image quality with little deterioration can be obtained.
[0014]
According to a fourth aspect of the present invention, in order to achieve the above object, the strobe light emitting means is configured to be able to change the irradiation angle of the strobe light so that the irradiation angle changes according to the magnification change of the subject. The electronic camera according to claim 1, wherein the electronic camera is controlled by the control unit.
[0015]
According to the present invention, the irradiation angle of the strobe light emitting means changes according to the change in magnification of the subject. Thereby, the strobe light can be used more efficiently and a brighter and better image can be obtained.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of an electronic camera according to the present invention will be described with reference to the accompanying drawings.
[0017]
1 and 2 are a front perspective view and a rear perspective view, respectively, showing an embodiment of an electronic camera according to the present invention.
[0018]
As shown in the figure, the camera body 12 of the electronic camera 10 of the present embodiment is formed in a flat rectangular box shape, and a power switch 14, a photographing lens 16, a strobe 18 and a viewfinder window are provided in front of the camera body 12. 20, a strobe light adjustment window 22 and the like are provided. A release button 24 is provided on the upper surface of the camera body 12, and a viewfinder eyepiece 30, a liquid crystal monitor 32, a mode switch 34, a zoom button 36, a macro button 38, a strobe button 40, a MENU / OK on the back surface. A button 42, a BACK button 44, a display button 46, and the like are provided.
[0019]
The power switch 14 provided at the front left corner of the camera body 12 functions as a grip of the camera 10, and an arc-shaped convex portion serving as a finger hook projects from the surface thereof. The power supply of the camera 10 is turned on / off by sliding the power switch 14 along the front of the camera body 12.
[0020]
The photographing lens 16 is constituted by a retractable zoom lens, and is extended from the front of the camera body 12 when the electronic camera 10 is turned on. The electronic camera 10 is retracted in the camera body 12 by turning off the power.
[0021]
The release button 24 provided on the upper surface of the camera body 12 is a two-stroke button composed of so-called “half-press” and “full-press”, and AF (Auto Focus: automatic) Focusing) and AE (Auto Exposure) function, and shooting is performed by “full pressing”.
[0022]
A liquid crystal monitor 32 provided on the back surface of the camera body 12 is used as a monitor for reproducing a photographed image, and is also used as an electronic viewfinder at the time of photographing. The display button 46 functions as an ON / OFF switching button of the electronic viewfinder.
[0023]
The mode switch 34 functions as a switch for switching the mode of the electronic camera 10, and is switched between a “shooting mode” for shooting a still image and a “playback mode” for playing back the shot image according to the set position.
[0024]
The zoom button 36 is configured as a seesaw button that can swing in the vertical direction, and functions as an operation button during zoom operation. That is, when the zoom button 36 is operated upward in the shooting mode, the zoom is operated in the tele direction, and by operating downward, the zoom is operated in the wide direction.
[0025]
The zoom button 36 also functions as a zoom button for a playback image under the playback mode. That is, when the zoom button 36 is operated upward in the playback mode, the playback image is enlarged and displayed, and when operated downward, the playback image is reduced and displayed.
[0026]
The macro button 38 functions as a button for switching ON / OFF of the macro function (close-up function), and the macro function is turned ON or OFF by pressing the macro button 38 in the photographing mode. The macro button 38 functions as a frame return button (a button for instructing to display an image one frame before) under the playback mode.
[0027]
The strobe button 40 functions as a button for switching the strobe mode. By pressing the strobe button 40 under the shooting mode, the strobe mode is set to each mode of strobe emission / emission prohibition. In addition, the strobe button 40 functions as a frame advance button (a button for supporting the display of the image after one frame) under the playback mode.
[0028]
The MENU / OK button 42 functions as a button for instructing display of a menu screen. When the MENU / OK button 42 is pressed, the menu screen is displayed on the liquid crystal monitor 32. The MENU / OK button 42 functions as a button for confirming the item selected from the menu screen and instructing the execution of the operation, and the BACK button 44 cancels the item selected on the menu screen or returns to the previous state. Functions as a button to instruct to return.
[0029]
When this menu screen is displayed, the three buttons, the zoom button 36, the macro button 38, and the flash button 40, function as cross keys, and menu items can be selected using these three buttons. Done.
[0030]
FIG. 3 is a block diagram showing an internal configuration of the electronic camera 10 of the present embodiment.
[0031]
As shown in the figure, an electronic camera 10 includes an image pickup device (CCD) 50, an analog signal processing circuit 52, an A / D converter 54, an image input controller 56, a memory 58, an image signal processing circuit 60, and an electronic zoom. Circuit 62, video encoder 64, AF detection circuit 68, AE / AWB detection circuit 66, compression / decompression processing circuit 70, memory controller 72, recording medium 74, ROM 76, strobe light emission circuit 78, zoom drive device 80, zoom drive circuit 82, An operation switch circuit unit 84, a CPU 88, and the like are provided.
[0032]
Operation information of each operation member such as the power switch 14, the release button 24, the mode switch 34, and the zoom button 36 provided on the camera body 12 is individually detected by the operation switch circuit unit 84 and input to the CPU 88 as an operation signal. The The CPU 88 controls the system based on the operation signal input from the operation switch circuit unit 84. The ROM 76 stores a camera control program executed by the CPU 88 and various setting data necessary for the control.
[0033]
Light emission of the strobe 18 is controlled by a strobe light emission circuit 78 based on a control signal from the CPU 88. The strobe 18 is a zoom strobe and is driven by a zoom driving device 80 to change the irradiation angle. The zoom drive device 80 is controlled to be driven by the CPU 88 via the zoom drive circuit 82, and the CPU 88 changes the irradiation angle of the strobe light in accordance with the change in the imaging field angle (the change in the magnification of the subject).
[0034]
The photographic lens 16 is zoomed by moving the zoom lens group 16A constituting a part thereof along the optical axis by the zoom lens driving device 92. The zoom lens driving device 92 is driven and controlled by the CPU 88 via the zoom lens driving circuit 94, and the CPU 88 controls the zoom lens driving device 92 based on the operation information of the zoom button 36 input from the operation switch circuit unit 84. To drive.
[0035]
The zoom encoder 96 detects the position of the zoom lens group 16 </ b> A, and outputs the detected position information to the CPU 88. The CPU 88 detects the focal length of the photographing lens 16 based on the position information of the zoom lens group 16 </ b> A detected by the zoom encoder 96.
[0036]
Now, under the photographing mode, the image light indicating the subject is imaged on the light receiving surface of the CCD 50 via the photographing lens 16. A large number of photosensors are arranged on the light receiving surface of the CCD 50, and the optical image of the subject formed on the light receiving surface is converted into signal charges of an amount corresponding to the amount of incident light by each photosensor. The signal charges accumulated in the respective photosensors are sequentially read according to the timing pulse given from the timing generator (TG) 90, and are output to the analog signal processing circuit 52 as a voltage signal corresponding to the signal charges.
[0037]
The analog signal processing circuit 52 includes a correlated double sampling processing circuit (CDS) and an amplifier (AMP), and the voltage signal sequentially read from the CCD 50 is sampled and held for each pixel, and amplified. The The analog RGB signal output from the analog signal processing circuit 52 is converted into a digital RGB signal by the A / D converter 54 and then temporarily stored in the memory 58 via the image input controller 56. To the image signal processing circuit 60.
[0038]
The image signal processing circuit 60 performs predetermined signal processing such as offset processing, gain control processing including white balance correction and sensitivity correction, and gamma correction processing on the input image signal, and the processed image data Is output to the memory 58.
[0039]
The image data is added from the image signal processing circuit 60 to the electronic zoom circuit 62 as necessary. The electronic zoom circuit 62 performs image enlargement / reduction processing. That is, a part of the captured image is cut out, and the cutout range is enlarged / reduced to perform image enlargement / reduction processing. Then, the enlarged / reduced image data is output to the memory 58.
[0040]
The image data written in the memory 58 is output to the video encoder 64, converted into a predetermined signal format such as the NTSC system, and then output to the liquid crystal monitor 32. The photographer determines the composition based on the image (through image) displayed on the liquid crystal monitor 32 and confirms the focus state.
[0041]
When the release button 24 is half-pressed in this state, the AE / AF is activated, and the image data output from the A / D converter 54 is transferred to the AE / AWB detection circuit 66 via the image input controller 56. And input to the AF detection circuit 68.
[0042]
The AE / AWB detection circuit 66 integrates RGB image data for each RGB for each divided region obtained by dividing the imaging region into 64 (horizontal 8 and vertical 8), and calculates the integrated data for each RGB for each region. It outputs to CPU88. The CPU 88 calculates the brightness (EV value) of the subject based on the integrated data input from the AE / AWB detection circuit 66, and determines the aperture value and the shutter speed based on the EV value.
[0043]
On the other hand, the AF detection circuit 68 calculates a contrast evaluation value representing the contrast of an image in a specific focus area (for example, the center of the imaging region) set in advance, and outputs the contrast evaluation value to the CPU 88. The CPU 88 performs AF control of the photographing lens 16 based on the contrast information input from the AF detection circuit 68 and focuses on the main subject.
[0044]
When AE / AF is completed and the release button 24 is fully pressed, the CPU 88 controls the aperture of a diaphragm (not shown) so that the determined aperture value is obtained, and charges the CCD 50 so that the determined shutter speed is achieved. Control the accumulation time. Further, strobe light is emitted from the strobe 18 via the strobe light emission circuit 78 as necessary.
[0045]
The image data for one frame imaged in this way is stored in the memory 58 from the image input controller 56 via the analog signal processing circuit 52 and the A / D converter 54. Then, it is read out from the memory 58 to the image signal processing circuit 60, where predetermined signal processing including generation processing (YC processing) of luminance data and color difference data is performed.
[0046]
The image data after the signal processing is temporarily stored in the memory 58 and then output to the compression / decompression processing circuit 70, where predetermined compression processing such as JPEG (Joint Photographic Experts Group) is performed. Thereafter, the compressed image data is temporarily stored in the memory 58 and then recorded on the recording medium 74 attached to the card slot via the memory controller 72.
[0047]
The image data shot and recorded in this manner is read from the recording medium 74 and displayed on the liquid crystal monitor 32 by setting the camera mode to the playback mode. That is, when the mode switch 34 is set to the reproduction mode, the image data recorded on the recording medium 74 is read out to the memory 58 and output from the memory 58 to the compression / decompression processing circuit 70. Then, after decompression processing is performed by the compression / decompression processing circuit 70, it is output to the liquid crystal monitor 32 via the video encoder 64. As a result, the image data recorded on the recording medium 74 is reproduced and displayed on the liquid crystal monitor 32.
[0048]
As described above, the electronic camera 10 according to the present embodiment has a zoom function, and the magnification of the subject is changed by operating the zoom button 36. This zoom includes an optical zoom that changes the magnification of the subject by moving a part of the photographing lens 16, and an electronic zoom that changes the magnification of the subject by cutting out a part of the captured image.
[0049]
The electronic camera 10 according to the present embodiment has both zoom functions, and normal shooting without using the strobe 18 is controlled to give priority to optical zoom, and strobe shooting is controlled to give priority to electronic zoom. At the time of flash photography, the electronic zoom is performed by cutting out an image around the optical axis of the flash light emitted from the flash 18. That is, as shown in FIG. 4A, in general, in the electronic zoom, a part of the captured image is cut out and zoomed around the optical axis of the photographing lens 16 (the center of the imaging area). In the camera 10, when zooming is performed during strobe light emission, an image is cut out and zoomed around the optical axis of the strobe light emitted from the strobe 18 as shown in FIG. This electronic zoom is executed at the wide end of the optical zoom, and when the electronic zoom reaches the tele end, it switches to the optical zoom.
[0050]
Here, as shown in FIG. 5, the optical axis of the strobe light emitted from the strobe 18 moves away from the optical axis of the photographing lens 16 as the optical zoom is zoomed from the wide end toward the tele end.
[0051]
Therefore, after shifting from the electronic zoom to the optical zoom, the cutout range of the electronic zoom is moved following the shift of the optical axis of the strobe light accompanying the change in magnification of the optical zoom. That is, the cutout range is always moved so that the center of the cutout range coincides with the optical axis of the strobe light. The ROM 76 stores data on the movement locus of the optical axis of the strobe light accompanying the change in magnification of the optical zoom.
[0052]
In this way, by performing electronic zoom around the optical axis of the strobe light emitted from the strobe 18, the strobe light can be used efficiently.
[0053]
Further, since the strobe 18 of the electronic camera 10 of the present embodiment is a zoom strobe, the strobe light can be concentrated on the imaging area, and the concentrated light can be used efficiently.
[0054]
FIG. 6 is a flowchart illustrating a processing procedure during a zoom operation. First, it is determined whether or not strobe light is emitted (step S10). That is, the CPU 88 detects the strobe mode based on the operation information of the strobe button 40 input from the operation switch circuit unit 84, and determines whether or not the strobe mode is set to the strobe emission mode.
[0055]
If the flash mode is set to the flash emission mode, the optical zoom is moved to the wide end (step S12). Then, the presence / absence of a zoom operation is monitored (step S14). When the photographer performs a zoom operation, the magnification of the subject is changed within the movable range of the electronic zoom (step S16). At this time, the electronic zoom cuts the captured image around the optical axis of the strobe light emitted from the strobe 18 and changes the magnification of the subject. The CPU 88 monitors whether or not the zoom operation has been performed beyond the movable range of the electronic zoom (step S18). If the angle of view is determined within the movable range of the electronic zoom, the release button 24 is pressed as it is. The photographing / recording process is executed according to the operation (step S20).
[0056]
On the other hand, when the zoom operation is performed in the tele direction beyond the movable range of the electronic zoom, the optical zoom is continuously operated (step S22). Then, the magnification of the subject is changed within the movable range of the optical zoom. At this time, as described above, the cutout range of the electronic zoom is moved by following the shift of the optical axis of the strobe light accompanying the change in the magnification of the optical zoom. When the angle of view is determined within the movable range of the optical zoom, the photographing / recording process is executed as it is according to the pressing operation of the release button 24 (step S20). If the zoom operation is performed in the wide direction beyond the movable range of the optical zoom, the magnification of the subject is changed by switching from the optical zoom to the electronic zoom.
[0057]
As described above, when the flash mode is the flash emission mode, the electronic zoom is prioritized and executed, and the optical zoom is used only when the electronic zoom is operated beyond the movable range of the electronic zoom.
[0058]
On the other hand, when the strobe mode is set to the light emission inhibition mode, the optical zoom is prioritized and operated. That is, the CPU 88 monitors the presence or absence of the zoom operation (step S24), and when the photographer performs the zoom operation, the magnification of the subject is changed within the movable range of the optical zoom (step S26).
[0059]
Then, it is monitored whether or not the zoom operation has been performed beyond the movable range of the optical zoom (step S28). If the angle of view is determined within the movable range of the optical zoom, the release button 24 is pressed as it is. Then, the photographing / recording process is executed (step S20).
[0060]
On the other hand, when the zoom operation is performed in the tele direction beyond the movable range of the optical zoom, the electronic zoom is continuously operated (step S30). Then, the magnification of the subject is changed within the movable range of the electronic zoom. At this time, the electronic zoom cuts out a captured image around the optical axis of the photographing lens 16 and changes the magnification of the subject. If the angle of view is determined within the movable range of the electronic zoom, the photographing / recording process is executed as it is according to the pressing operation of the release button 24 (step S20). Note that when the zoom operation is performed in the wide direction beyond the movable range of the electronic zoom during the electronic zoom, the magnification of the subject is changed by switching from the electronic zoom to the optical zoom.
[0061]
As described above, when the strobe mode is the light emission prohibition mode, the optical zoom is prioritized and executed, and the electronic zoom is used only when operated in the tele direction beyond the movable range of the optical zoom.
[0062]
As described above, in the electronic camera 10 of the present embodiment, when a zoom operation is performed during strobe light emission, the electronic zoom is preferentially operated at the wide end position of the optical zoom. As a result, even with a zoom lens that tends to be dark, zooming can be performed at a relatively bright (small F value) wide end position, and a bright and good image can be obtained.
[0063]
In addition, since the electronic zoom is performed by cutting out the image around the optical axis of the strobe light during electronic zoom, the center of the strobe light and the center of the captured image can be matched, and the strobe light can be used efficiently. . Thereby, a bright and favorable image can be obtained.
[0064]
In particular, since the electronic camera 10 according to the present embodiment uses the strobe 18 as a zoom strobe, the light concentrated in the imaging area can be used without waste, and a brighter and better image can be obtained.
[0065]
In this embodiment, an example in which the present invention is applied to an electronic camera that performs zooming using both optical zoom and electronic zoom has been described. However, the present invention is similarly applied to an electronic camera camera that includes only electronic zoom. can do. In this case as well, during flash emission, an image is cut out around the optical axis of the flash light and electronic zoom is executed. Also in this case, the strobe is preferably a zoom strobe, and the irradiation angle is preferably changed in accordance with the change in magnification of the subject.
[0066]
Further, although the electronic camera 10 of the present embodiment includes an optical viewfinder, it is preferable that the electronic zoom always turns on the display of the liquid crystal monitor 32 to display a through image.
[0067]
Further, a field frame or the like may be provided in the optical viewfinder so that the field frame moves in conjunction with zooming.
[0068]
【The invention's effect】
As described above, according to the present invention, the electronic zoom is performed by cutting out the image around the optical axis of the strobe light emitted from the strobe light emission means when the strobe is emitted, so that the strobe light can be used efficiently. it can. Thereby, a bright and favorable image can be obtained.
[Brief description of the drawings]
FIG. 1 is a front view showing an embodiment of an electronic camera to which the present invention is applied.
FIG. 2 is a rear view showing an embodiment of an electronic camera to which the present invention is applied.
FIG. 3 is a block diagram showing the internal structure of the electronic camera.
FIG. 4 is an explanatory diagram of electronic zoom.
FIG. 5 is an explanatory diagram of electronic zoom.
FIG. 6 is a flowchart illustrating a processing procedure during zoom operation.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Electronic camera, 12 ... Camera body, 14 ... Power switch, 16 ... Shooting lens, 16A ... Zoom lens group, 18 ... Strobe, 20 ... Viewfinder window, 22 ... Strobe light control window, 24 ... Release button, 30 ... Viewfinder Eyepiece, 32 ... Liquid crystal monitor, 34 ... Mode switch, 36 ... Zoom button, 38 ... Macro button, 40 ... Strobe button, 42 ... MENU / OK button, 44 ... BACK button, 46 ... Display button, 50 ... Image sensor (CCD), 52 ... analog signal processing circuit, 54 ... A / D converter, 56 ... image input controller, 58 ... memory, 60 ... image signal processing circuit, 62 ... electronic zoom circuit, 64 ... video encoder, 66 ... AE AWB detection circuit, 68 ... AF detection circuit, 70 ... compression / decompression processing circuit, 72 ... memory controller, 74 ... Media: 76 ... ROM 78: Strobe light emission circuit 80 ... Zoom drive device 82 ... Zoom drive circuit 84 ... Operation switch circuit unit 88 ... CPU 90 ... Timing generator (TG) 92 ... Zoom lens drive device 94 ... Zoom lens drive circuit, 96 ... Zoom encoder

Claims (4)

A strobe light emitting unit that emits strobe light toward the subject, an electronic zoom unit that cuts out part of the image captured by the imaging unit and changes the magnification of the subject,
Zoom operation means for giving an instruction to change the magnification of the subject;
Control means for controlling the electronic zoom means based on an instruction from the zoom operation means, wherein the electronic zoom means is configured to cut out an image around the optical axis of strobe light emitted from the strobe light emission means during strobe light emission. Control means for controlling the zoom means;
An electronic camera characterized by comprising: An optical zoom unit that is controlled by the control unit to change the magnification of the subject by moving a part of the photographic lens, and at the time of flash emission, the control unit changes the magnification of the subject by the electronic zoom unit. 2. The electronic zoom unit is controlled to change the magnification of a subject by the optical zoom unit and to cut out an image around an optical axis of strobe light emitted from the strobe light emitting unit. The electronic camera described. When the strobe is not lighted, the control means changes the magnification of the subject with the optical zoom means based on an instruction from the zoom operation means, and then uses the electronic zoom means to display an image around the optical axis of the photographing lens. The electronic camera according to claim 2, wherein the electronic camera is cut out to change a magnification of the subject. The said strobe light emission means is comprised so that change of the irradiation angle of strobe light is possible, and is controlled by the said control means so that an irradiation angle may change according to the magnification change of a to-be-photographed object, or 1 or 2 characterized by the above-mentioned. 3. The electronic camera according to 3.

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