Abstract:
The present invention provides a digital camera that has an EVF, an LCD screen, a switching unit, and display-state restoring unit. The switching unit switches display to the EVF or the LCD screen in accordance with an input signal. The display-state restoring unit automatically restores the EVF and the LCD screen to states that they assume before the switching unit switches the display, when a process initiated by the input signal is completed.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
         [0001]    This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2003-188707, filed Jun. 30, 2003, the entire contents of which are incorporated herein by reference.  
         BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates to a digital camera which has a plurality of display screens and which is user-friendly.  
           [0004]    2. Description of the Related Art  
           [0005]    Digital cameras have been developed. They can acquire an optical image of an object, generate an electric video signal representing the optical image acquired, convert the video signal to digital data, and store the digital data in a digital recording medium. Some of the digital cameras have a display screen (liquid crystal panel, hereinafter called “LCD screen”), in addition to the electronic viewfinder (hereinafter referred to as “EVF”). The LCD screen is relatively large. It enables the user to confirm any image just photographed and any image reproduced from digital data stored in the recording medium.  
           [0006]    The user may look at the EVF to adjust the zooming in accordance with what he or she sees in the EVF. The LCD screen is another useful display screen. It can display the images reproduced from the digital data stored in the recording medium, enabling the user to confirm the images he or she has photographed.  
           [0007]    Specific uses of such two display screens are disclosed in, for example, Jap. Pat. Appln. KOKAI Publication 2001-169150. More specifically, the user uses the EVF (i.e., looking-into type display) displays the image being photographed, whereas the LCD screen displays information other than images (e.g., the operating conditions of the camera, the operation menu, and the like). Since the two display screens display different information items, the camera is more user-friendly than otherwise.  
           [0008]    It has not been profoundly studied how to use the EVF and LCD screen on any digital camera hereto developed display. Hitherto, the two display screens display either the same information or different items of information, in accordance with the user&#39;s instructions.  
         BRIEF SUMMARY OF THE INVENTION  
         [0009]    Accordingly, an object of the present invention is to provide a digital camera with a plurality of display screens, in which two display units can be automatically switched when the user changes the operating mode of the camera, to display the most desirable information items, and which is therefore convenient to the user.  
           [0010]    According to an aspect of the invention, there is provided a digital camera having a camera body, first display means with a display area, second display means with a display area larger than the display area of the first display means, and a display-state switching means for switching from the first display means to the second switching means, or vice versa, so that one display means is on and the other display means is off. The digital camera comprises: switching means for forcibly switching display to the first display means or the second display means in accordance with an input signal; and display-state restoring means for automatically restoring the first display means and the second to states that the first display means and the second assume before the switching means switches the display, when a process initiated by the input signal is completed.  
           [0011]    Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.  
       
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING  
       [0012]    The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments of the invention, and together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention.  
         [0013]    [0013]FIG. 1A is a perspective view of a digital camera seen from the front;  
         [0014]    [0014]FIG. 1B is a plan view of the mode dial provided on the digital camera shown in FIG. 1A;  
         [0015]    [0015]FIG. 2 is another plan view of the digital camera seen from the back and somewhat below;  
         [0016]    [0016]FIG. 3 is a block diagram illustrating the optical section and electric section of the digital camera; and  
         [0017]    [0017]FIG. 4 is a diagram representing the operation transition that the digital camera undergoes while being used. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0018]    An embodiment of the invention will be described below, with reference to the accompanying drawings.  
         [0019]    [0019]FIG. 1A is a perspective view of a digital camera according to the invention, as seen from the front. FIG. 2 is another plan view of the digital camera seen from the back and somewhat below.  
         [0020]    As FIG. 1A shows, the digital camera has a shutter button  1001 , a mode dial  1002 , and a power switch  1003 . The camera also has a display unit  1004  called “front LED.” The display unit  1004  characterizes the digital camera.  
         [0021]    The digital camera further has a flash lamp  1005 , a speaker  1006 , a microphone  1007 , a remote-control light-receiving  1008 , a flash-light adjusting sensor  1009 , and a lens  1010 .  
         [0022]    The digital camera has a terminal cover  1012 . The cover  1012  may be opened to expose an external-microphone terminal, a digital-data output terminal, an AV terminal and a DC-input terminal.  
         [0023]    [0023]FIG. 1B illustrates the mode dial  1002 . The mode dial  1002  has icons printed on it. The icons represent various modes in which the camera can operate. Icon A 1  represents the manual-photographing mode (in which the white balance, exposure time, diaphragm opening, shutter speed, and the like can be manually controlled). Icon A 2  represents the moving-picture mode (in which a moving picture can be photographed). Icon A 3  represents the setup mode (in which the basic setups of the camera, e.g., sound, automatic power-off, customizing, language, video-data output, date and system mode). Icon A 4  represents the PC mode (in which video data is input to personal computers). Icon A 5  represents the reproduction mode, and icon A 6  represents the automatic photographing mode. The user may turn the mode dial  1002  to bring one of icons A 1  to A 6  to a specified position, thereby to select the operating mode that the icon represents.  
         [0024]    As FIG. 2 shows, a flash button  1021 , a menu button  1022 , a self-timer &amp; remote-control button  1023 , an erase button  1024 , and a visibility-adjusting dial  1025  are arranged on the back of the camera. An EVF  1026  and a liquid display unit  1027  are provided on the back of the camera, too. The liquid display unit  1027  has a screen larger than that of the EVF  1026 , which is a liquid crystal display, too. The unit  1027  will be called “LCD screen” so that it may be distinguished from the EVF  1026 . A finder LED  1028  is arranged besides the EVF  1026 ; it may emit light to show that the EVF  1026  is on. A shoulder-strap holder  1029  is secured to one side of the camera.  
         [0025]    Moreover, a Tele/Wide button  1031 , an OK button  1033  and selection buttons  1034  are provided on the back of the camera. When operated, the Tele/Wide button  1031  set a degree of zooming. When pushed, each selection button  1034  selects a menu items or an image. A guard cover  1032  is laid on the corner defined by the back and one side of the camera. A battery cover  1035  is provided on the bottom of the camera. A screw hole  1036  is cut in the bottom of the camera, to hold the top of a tripod.  
         [0026]    A display button  1037  is arranged on the back of the camera. When depressed, the display button  1037  switches the display mode of the EVF  1026  and LCD screen  1027 . If pushed rather long, the display button  1037  sets the EVF  1026  and the LCD screen  1027  in sleep mode to save the battery power. The LCD screen  1027  has a size ranging from 1.5 to 2.5 inches, as most display units of this type. By contrast, the EVF  1026  is a small peeping window.  
         [0027]    [0027]FIG. 3 is a block diagram that illustrates the optical section and electric section of the digital camera. As may be understood from FIG. 3, the light from the object passes through a lens  11  and reaches the image-forming surface of an imaging element  12  (e.g., a CCD element), thus forming an image of the object. The imaging element  12  converts the image into an electric signal. The electric signal is supplied to an analog-to-digital (A/D) conversion unit  13 . The unit  13  converts the signal to a digital signal, which is input to a signal-processing unit  14 . The signal-processing unit  14  performs gamma correction, color-signal separation, white-balance control, and the like.  
         [0028]    Unless the shutter is operated in normal photographing conditions, the signal-processing unit  14  outputs video data via a memory controller  15  to an image-display processing unit  61 . The processing unit  61  converts the video data to data that the EVF  624  or LCD screen  622  can display and combines menu items or the like data items, thus generating new video data. This video data is supplied from the image-display processing unit  61  to the LCD driver  621  and/or the EVF driver  623 , both incorporated in a display  62 . Thus, the EVF  624  and/or the LCD screen  622  displays the image being photographed.  
         [0029]    When the shutter is operated, an image compression/expansion unit  16  compresses the video data (in JPEG mode, for example). The video data thus compressed is stored via a recording-medium interface  31  into a recording medium  32  under the control of a CPU (Central Processing Unit)  20 . The recording medium  32  may be one selected from various media. It may be, for example, a semiconductor memory, an optical disk or a magnetic disk.  
         [0030]    The video data may be read from the recording medium  32 . In this case, the image compression/expansion unit  16  expands the video data under the control of the CPU  20 . The video data thus expanded is input to the image-display processing unit  61  via the memory controller  15 . Thus, the EVF  624  or the LCD screen  622  displays the image represented by the video data.  
         [0031]    A work memory  17  is used in the process of editing the video data, forming a thumbnail image or changing the order of images. The work memory  17  can store one frame of video data or frames of video data. The video data stored in the work memory  17  is input, whenever necessary, to the image-display processing unit  61  via the memory controller  15 . Thus, the user can know how the video data is being edited, looking at the image displayed on either the EVF  624  or the LCD screen  622 .  
         [0032]    While the video data is being generated or edited, audio data can be acquired from a microphone  43  via an audio interface  41  under the control of the CPU  20 . The audio data is stored, along with the video data, in the recording medium  32 . The audio data is read from the recording medium  32 , together with the video data. It is then supplied via the audio interface  41  to a speaker  42 . The speaker  42  generates sound from the audio data. According to this invention, the speaker  42  may not generate sound when the user wants to confirm the image only. This is a characterizing feature of the camera according to this invention.  
         [0033]    In preparation for a photographing operation, the CPU  20  makes a control unit  18  perform zooming, automatic iris-adjustment (AE), automatic focusing (AF), flash control and the like in accordance with control signals. The CPU  20  receives operation signals from external devices through an operation unit  21  and a remote-control receipt unit  22 . The CPU  20  is connected to an external connection interface (not shown). Hence, the camera can be connected to external displays such as TVs.  
         [0034]    The CPU  20  can control an operating-mode display called “front LED  51 .” The front LED  51  can emit light in different colors and in various modes to inform the user of the current operating mode of the camera. More precisely, the front LED  51  can emit light in, for example, six colors. It can emit light in each color in, for example, four modes, i.e., slow blinking, rapid blinking, continuous light-emission and intermittent light-emission.  
         [0035]    The user can combine each light-emitting mode with the colors in which the front LED  51  can emit. In other words, the user can customize various mode-color combinations that indicate various modes in which the camera may operate. This customization is another characterizing feature of the camera according to this invention.  
         [0036]    The camera of this invention is particularly characterized in that the first display unit (EVF) and the second display unit (LCD screen) larger than the first display unit are automatically switched, in accordance with the data input to the camera and the current operating mode of the camera. Thus, the two display units can display two information items that are desirable in view of the mode in which the camera is operating.  
         [0037]    The CPU  20  has a customizing unit, an audio-data-processing unit, and a display-switching unit. The customizing unit customizes various mode-color combinations. The audio-data-processing unit processes audio data. The display-switching unit switches the two display units. The CPU further has a means for switching the operating mode of each display unit, and for recovering the state of each display unit to the previous operating mode. The previous operating mode is, for example, the status that is set when the power switch was turned off.  
         [0038]    [0038]FIG. 4 is a diagram representing the operation transition that the digital camera undergoes while being used. FIG. 4 is a flowchart, too, which illustrates how the CPU  20  controls some of the other components of the digital camera. When the power switch is turned on, the LCD screen  622  ( 1027 , in FIG. 2) displays the starting menu. Assume that the power switch is turned on for the first time (S 1 →S 2 ) so that the camera is used for the first time. Then, the EVF  624  (or  1026  in FIG. 2) displays data in the case where icon A 6  (automatic photographing mode), icon A 1  (manual photographing mode), or icon A 2  (moving-picture mode) has been selected, or the LCD screen  622  (or  1027  in FIG. 2) displays data in the case where icon A 5  (reproduction mode) has been selected. The user may depress the display button  1037  to switch the display from the LCD screen  622  to the EVF  624 , or vice versa.  
         [0039]    Assume that the camera has been used several times. In this case, the operating state of the camera changes S 1 →S 2 →S 3  if the user has selected icon A 5  (reproduction mode) by turning the mode dial  1002 , or S 1 →S 2 →S 4  if the user has selected either icon A 1  (manual photographing mode) or icon A 6  (automatic photographing mode) or icon A 2 . In State S 3 , the display is switched to the one that operated in the last reproduction of data. In State S 4 , the display is switched to the one that operated in the last photographing. If the user has selected any mode other than the reproduction mode, manual photographing mode and automatic photographing mode or moving picture mode?, the camera enters State S 5 . Then, the LCD screen  622  (or  1027  in FIG. 2) operates.  
         [0040]    The operating mode of the camera may be changed to, for example, the reproduction mode while the camera remains in State S 5 . If so, the camera enters State S 3 . If the camera is set to the manual or automatic photographing mode or moving picture mode, it enters State S 4 . It is natural that the camera goes from State S 3  to State S 6  (data reproduction), and that it goes from State S 4  to S 7  (photographing).  
         [0041]    The user may operate the menu key while the camera remains in State S 6  (data reproduction). In this case, the camera enters State S 8 , in which the LCD screen  622  (or  1027  in FIG. 2) displays the menu. When the user finishes selecting at least one menu item, the camera resumes State S 6 . Thus, the display is switched to the one that operated in the last reproduction of data. While the camera remains in State S 6 , it may be set to a video-on mode (to supply signals reproduced to an external monitor, e.g., a TV, through a digital-data terminal shown in FIG. 1A). Then, the camera assumes State S 11 , in which both the LCD screen  622  and the EVF  624  (or  1026  in FIG. 2) are turned off. Once the camera has been set to the video-off mode, it enters State S 6 . While the camera remains in State S 6  (or in the reproduction mode), the user may depress the display button  1037  to switch the display from the LCD screen  622  to the EVF  624 , or vice versa, in State S 11 .  
         [0042]    While the camera remains in State S 7  (photographing), the user may depress the menu key. If this is the case, the camera is made to enter State S 12 , in which the LCD screen  622  (or  1027  in FIG. 2) displays the menu. The user can therefore select one menu item or more menu items. When the user finishes selecting menu items, the camera resumes State S 7 . Therefore, the display is switched to the one that operated in the last photographing. While the camera remains in State S 7 , it may be set to a video-on mode (to supply signals reproduced to an external monitor, e.g., a TV, through a digital-data terminal shown in FIG. 1A). If so, the camera assumes State S 13 , in which both the LCD screen  622  and the EVF  624  are turned off. Once the camera has been set to the video-off mode, it enters State S 7 . While the camera remains in State S 7  (photographing), the user may depress the display button  1037  to switch the display from the LCD screen  622  to the EVF  624 , or vice versa, in State S 14 .  
         [0043]    In the present invention, the display is forcibly switched to the LCD screen if the EVF is operating when the user pushes the menu key. Once the user finishes selecting one menu item or more menu items, the display is switched back to the EVF.  
         [0044]    Every time the camera is turned on, the LCD screen is operated to display the setup menu because it can display the menu larger than the EVF does. Every time the camera is turned off, the data showing which display EVF or LCD screen, has been operating, is stored in a memory so that this display may be used when the power switch is turned on next time. Thus, if the camera is turned off in the reproduction mode while the EVF, for example, is displaying data, the LCD screen will start operating when the camera is turned on in starting or initial mode and the display will thereafter switched from the LCD screen to the EVF (State S 3 ). When the camera is connected to an external display such as a TV monitor, both the LCD screen and the EVF are turned off to save power.  
         [0045]    Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.