Abstract:
An image capture apparatus has a continuous photographing mode for continuously photographing still images. The image capture apparatus includes an image capture unit, a pseudo shutter curtain generating unit, an image synthesizing unit, and a display unit. The image capture unit generates an image signal of an object. The pseudo shutter curtain generating unit generates a pseudo shutter curtain signal corresponding to a pseudo shutter curtain. The image synthesizing unit synthesizes the image signal generated by the image capture unit and the pseudo shutter curtain signal generated by the pseudo shutter curtain generating unit. The display unit displays the image signal and the pseudo shutter curtain signal. The pseudo shutter curtain generating unit sets the pseudo shutter curtain to be translucent, if the image capture apparatus is in the continuous photographing mode.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to an image capture apparatus such as a digital camera. 
   2. Related Background Art 
   In recent years, the number of digital camera systems have been increasing in which when a photographer depresses a release button for photographing a still image, a pseudo shutter curtain is displayed, and a mechanical shutter sound is output to the photographer as in a silver film camera, so that the photographer can realize the photographing of the still image (see, e.g., Japanese Patent Application Laid-Open No. 2000-184240). 
   Moreover, in recent years, the number of digital camera systems have been increasing which is provided with not only a function of photographing the still image but also varieties of functions such as a continuous photographing function capable of continuously photographing the still image and an auto exposure bracket (AEB) function of automatically deflecting exposure in a “+” or “−” direction to perform the photographing. 
   Furthermore, there are: a system in which a pseudo shutter curtain effect during single photographing is utilized as such during continuous photographing; and a system in which a pseudo shutter curtain is synthesized in only first photographing during the continuous photographing, and the pseudo shutter curtain is not displayed in second and subsequent photographing. 
   As to effects produced by the above-described pseudo shutter curtain, the curtain is very effective because the photographer can recognize the moment at which the still image has been photographed during single photographing. However, when the still image is continuously photographed, the pseudo shutter curtain opens and closes every time the photographing is performed. Therefore, an object displayed in a liquid crystal monitor is obstructed. Moreover, in a case where the photographer chases and photographs a moving object during the continuous photographing, there is a problem that the pseudo shutter curtain hinders the object from being easily recognized. 
   Especially in these years, the continuous photographing has been speeded up, and the number of still images which can be photographed in one second has been increasing. Therefore, when the number of the still images that can be photographed in one second increases, the object displayed in the liquid crystal monitor is covered with the pseudo shutter curtain more. Therefore, in a case where the continuous photographing is performed at a high seed, a time for which an operator cannot recognize the object increases. In consequence, visibility of the object is remarkably impaired in the high-speed continuous still-image photographing. 
   To avoid the above-described disadvantage, there is a system in which the pseudo shutter curtain is displayed in the liquid crystal monitor in the only first photographing during the continuous photographing. In this system, the photographer cannot easily recognize a time when the continuous photographing has been completed, and this might generate a disadvantage that “the last important scene could not be photographed during the continuous photographing”. 
   SUMMARY OF THE INVENTION 
   The present invention is to overcome the above-described drawbacks. 
   Another object of the present invention is to inform a photographer that continuous photographing is being performed, and display an object in a display device as easily viewably as possible. 
   According to an aspect of the present invention, there is provided an image capture apparatus comprising: an image capture unit adapted to generate an image signal of an object; a display unit adapted to display the image signal; a pseudo shutter curtain generation unit adapted to generate a pseudo shutter curtain signal for displaying a pseudo shutter curtain; an image synthesization unit adapted to synthesize the image signal generated by the image capture unit and the pseudo shutter curtain signal generated by the pseudo shutter curtain generation unit; and a control unit adapted to control operations of the image capture unit, the pseudo shutter curtain generation unit, and the image synthesization unit, wherein the control unit controls the operations of the pseudo shutter curtain generation unit and the image synthesization unit in accordance with an image capture state of the image capture unit. 
   Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate an embodiment of the present invention and, together with the description, serve to explain the principles of the present invention. 
       FIG. 1  is a block diagram showing a main part constitution example of a digital camera in an embodiment of the present invention; 
       FIG. 2  is a flowchart showing continuous and single photographing operations of a system controller in the embodiment; 
       FIG. 3  is a flowchart showing an AEB continuous photographing operation; 
       FIG. 4  is a block diagram showing a pseudo shutter curtain generation circuit and a synthesization circuit; and 
       FIG. 5  is a diagram showing a display example of a pseudo shutter curtain in a liquid crystal monitor. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Preferred embodiments of the present invention will be described in detail below with reference to the drawings. 
   First Embodiment 
   An embodiment of the present invention will be described hereinafter with reference to the drawings. 
     FIG. 1  is a block diagram showing a constitution example of a digital camera (image capture apparatus) of the present embodiment. In  FIG. 1 , reference numeral  1  denotes a focus lens for focusing the camera. Light passed through the focus lens  1  is formed into an image on an image capture plane of a CCD  2 , and photoelectrically converted into an electric signal. 
   The signal photoelectrically converted on the image capture plane of the CCD  2  is read in accordance with a reference clock, sampled and held by CDS/AGC  3 , controlled into an optimum gain under control of a system controller  12 , and then converted into a digital signal synchronized with the reference clock by an A/D converter  4 . 
   An image signal P 1  converted into the digital signal by the A/D converter  4  is sent to a camera signal processing circuit  5 . The image signal P 1  sent to the camera signal processing circuit  5  is subjected to various signal processing to generate image data P 2 . 
   The image data P 2  generated by the camera signal processing circuit  5  is temporarily retained in a frame memory  7  by a memory controller  6 . As separately described later, the camera signal processing circuit  5  contains a synthesization circuit  5   a  and a pseudo shutter curtain generation circuit  5   b  (see  FIG. 4 ), and the image data P 2  read from the frame memory  7  and a pseudo shutter curtain signal P 3  generated by the pseudo shutter curtain generation circuit  5   b  are synthesized by the synthesization circuit  5   a.    
   A liquid crystal driver  8  converts photographing image data P 4  output from the camera signal processing circuit  5  into a signal for displaying the data in a liquid crystal panel  9 , and the data is displayed as a captured image in the liquid crystal panel  9 . A compression circuit  10  compresses still or moving image data output from the camera signal processing circuit  5  at a compression ratio indicated by the system controller  12  to produce compressed image data P 5 , and records the data in a memory card  11 . 
   A still image/moving image changeover switch  13  is arranged as means for determining whether to photograph the object as a still image or a moving image. A still image release switch  14  is input means for notifying the system controller  12  of a timing to take in the still image, when the still image is photographed. The system controller  12  is control means for controlling the whole operation of a digital camera. A single/continuous/AEB photographing changeover switch  15  is a switch for switching the photographing of the still image to the single photographing or the continuous photographing, and for deflecting a parameter of brightness from correct exposure to over (+) or under (−) exposure to switch the photographing to an auto exposure bracket (AEB) for continuous photographing. 
   Next, there will be described an operation procedure of the digital camera of the present embodiment with reference to a flowchart of  FIG. 2 . It is to be noted that in the present embodiment, a “continuous photographing mode” is a photographing mode to continuously photograph still images of a plurality of frames while the release switch continues to be depressed. A “single photographing mode” is a photographing mode to photograph the still image of one frame every time the release switch is depressed. An “AEB continuous photographing” is a photographing mode to continuously photograph the still image of a plurality of frames (e.g., still images of three frames) while automatically changing exposure conditions. 
   In the present embodiment, when a power supply is turned on, the system controller  12  starts its operation in step S 201 . In the present embodiment, while power is supplied to the digital camera, processing of steps S 201  to S 218  is repeatedly performed in a certain cycle. 
   When the operation is started in the step S 201 , the processing advances to step S 202  to judge whether or not the camera is on still image processing. As a result of this judgment, when the camera is not on the still image processing, the processing advances to step S 203  to judge whether or not a mode is a still image mode. As a result of the judgment, when the mode is not the still image mode, the processing advances to step S 218 , thereby terminating this processing. 
   On the other hand, as a result of the judgment of the step S 203 , when it is judged that the mode is the still image mode, the processing advances to step S 204  to judge whether the camera is in the continuous still-image photographing mode or the single photographing. This judgment is performed based on an input from the single/continuous/AEB photographing changeover switch  15 . 
   When the single photographing mode is judged in the step S 204 , the processing advances to step S 208  to judge whether or not the release switch  14  is depressed. As a result of the judgment of the step S 208 , unless the release switch  14  is depressed, the processing advances to the step S 218 , thereby terminating this processing. 
   On the other hand, as a result of the judgment of the step S 208 , when the release switch  14  is depressed, the processing advances to step S 209  to set color and brightness of the pseudo shutter curtain for the single photographing. Then, the processing advances to step S 210  to start the single still-image photographing. Subsequently, the processing advances to the step S 218 , thereby terminating this processing. 
   On the other hand, as a result of the judgment of the step S 204 , when the continuous still-image photographing mode is judged, the processing advances to step S 205  to judge whether or not the release switch  14  is depressed. As a result of the judgment of the step S 205 , unless the release switch  14  is depressed, the processing advances to the step S 218 , thereby terminating this processing. 
   Moreover, as a result of the judgment of the step S 205 , when the release switch  14  is depressed, the processing advances to step S 206  to set the pseudo shutter curtain for the continuous photographing. Moreover, the processing advances to step S 207  to start the continuous still-image photographing. The processing advances to the step S 218 , thereby terminating this processing. 
   On the other hand, as a result of the judgment of the step S 202 , when it is judged that the camera is on the still-image photographing, the processing advances to step S 211  to judge whether the mode is the continuous still-image photographing or the single photographing. This judgment is performed based on the input from the single/continuous/AEB photographing changeover switch  15 . 
   As a result of the judgment of the step S 211 , when the single photographing mode is judged, the processing advances to step S 215 . After the pseudo shutter curtains gradually cover a screen from screen upper and lower parts thereof to cover the whole screen, a position is calculated to perform reverse processing, and area information is transmitted to the synthesization circuit  5   a  in the camera signal processing circuit  5  described later. Then, the processing advances to step S 216  to perform the single photographing. Thereafter, the processing advances to the step S 218 , thereby terminating this processing. 
   Moreover, as a result of the judgment of the step S 211 , when it is judged that the camera is in the continuous still-image photographing mode, the processing advances to step S 212  to judge whether or not the release switch  14  is depressed. As a result of the judgment, unless the release switch  14  is depressed, the photographer judges that the continuous still-image photographing is completed. The processing advances to step S 217  to perform processing to complete the continuous still-image photographing. Thereafter, the processing advances to the step S 218 , thereby terminating this processing. 
   On the other hand, as a result of the judgment of the step S 212 , when the release switch  14  is depressed, it is judged that the continuous still-image photographing continues. The processing advances to step S 213 . After the pseudo shutter curtains gradually cover the screen from the screen upper and lower parts thereof to cover the whole screen, the position is calculated to perform the reverse processing, and the area information is transmitted to the synthesization circuit  5   a  in the camera signal processing circuit  5  described later. Next, the processing advances to step S 214  to perform the continuous still-image photographing. Thereafter, the processing advances to the step S 218 , thereby terminating this processing. 
   As described above, according to the digital camera of the present embodiment, the pseudo shutter curtain is set to be translucent for the continuous still-image photographing, and visibility of the object during the continuous still-image photographing is remarkably enhanced. A control is executed so that it can be visually recognized, without depending on character display, that the continuous still-image photographing is being performed. 
   Accordingly, the pseudo shutter curtain can be displayed on the displayed image in accordance with a continuous photographing speed, and the visibility of the object during the high-speed continuous still-image photographing can be remarkably enhanced. 
   Moreover, when the pseudo shutter curtain is set to 100% of black during the single photographing, a usual shutter curtain effect can be exerted. When the color or the brightness of the pseudo shutter curtain is varied in accordance with an internal state of the digital camera, that is, a changeover state to the continuous/single photographing in this manner, there can be produced the pseudo shutter curtain effect that the photographer can easily recognize the object. 
   Second Embodiment 
   Next, there will be described processing by a system controller  12  during the AEB continuous photographing with reference to a flowchart showing an AEB continuous photographing operation in  FIG. 3 . 
   When a power supply is turned on, the system controller  12  starts its operation in step S 301 . While power is supplied to a digital camera, processing of steps S 301  to S 318  is repeatedly performed in a certain cycle. 
   When the operation is started in the step S 301 , the processing advances to step S 302  to judge whether or not the camera is on AEB continuous still-image processing. As a result of this judgment, when the camera is not on the AEB continuous still-image processing, the processing advances to step S 303  to judge whether or not a mode is a still-image mode. As a result of the judgment, when the mode is not the still image mode, the processing advances to step S 318 , thereby terminating this processing. 
   Moreover, as a result of the judgment of the step S 303 , when it is judged that the mode is the still image mode, the processing advances to step S 304  to judge whether or not the camera is in the AEB continuous photographing mode, based on an input from a single/continuous/AEB photographing changeover switch  15 . As a result of the judgment of the step S 304 , when the AEB continuous photographing mode is judged, the processing advances to step S 305  to judge whether or not a release switch  14  is depressed. As a result of the judgment of the step S 305 , unless the release switch  14  is depressed, the processing advances to the step S 318 , thereby terminating this processing. 
   Furthermore, when the release switch  14  is depressed in the step S 305 , the processing advances to step S 306  to start the AEB continuous photographing. Thereafter, the processing advances to the step S 318 , thereby terminating this processing. When it is judged in the step S 304  that the mode is not the AEB continuous photographing mode, the processing advances to the step S 318 , thereby terminating this processing. 
   On the other hand, there will be described a case where it is judged that the camera is photographing the still image as a result of the judgment of the step S 302 . As a result of the judgment of the step S 302 , when it is judged that the camera is on the AEB photographing processing, the processing advances to step S 307  to judge whether or not first AEB still-image photographing is performed. As a result of this judgment, when it is judged that the first photographing is performed, the processing advances to step S 308  to set color and brightness of a pseudo shutter curtain for the first AEB photographing. 
   Then, the processing advances to step S 309 . After the pseudo shutter curtains gradually cover a screen from upper and lower parts thereof to cover the whole screen, a position is calculated to perform reverse processing, and area information is transmitted to a synthesization circuit  5   a  in a camera signal processing circuit  5  described later. Next, the processing advances to step S 310  to perform the first photographing of the AEB continuous photographing. Thereafter, the processing advances to the step S 318 , thereby ending this processing. 
   Moreover, as a result of the judgment of step S 307 , when it is judged that the first photographing is not performed, the processing advances to step S 311  to judge whether or not second photographing is performed in the AEB continuous photographing. As a result of the judgment, when it is judged that the second photographing is performed, the processing advances to step S 312  to set the color and brightness of the pseudo shutter curtain for the second AEB photographing. Then, the processing advances to step S 313 . After the pseudo shutter curtains gradually cover the screen from the upper and lower parts thereof to cover the whole screen, the position is calculated to perform reverse processing, and the area information is transmitted to the synthesization circuit  5   a  in the camera signal processing circuit  5  described later. Next, the processing advances to step S 314  to perform the second still-image photographing in the AEB continuous photographing. Thereafter, the processing advances to the step S 318 , thereby terminating this processing. 
   Furthermore, when it is judged in the step S 311  that the second photographing is not performed, the processing advances to step S 315  to set the color and brightness of the pseudo shutter curtain for the third AEB photographing. Next, the processing advances to step S 316 . After the pseudo shutter curtains gradually cover the screen from the upper and lower parts thereof to cover the whole screen, the position is calculated to perform the reverse processing, and the area information is transmitted to the synthesization circuit  5   a  in the camera signal processing circuit  5  described later. Next, the processing advances to step S 317  to perform the third still-image photographing in the AEB continuous photographing. Thereafter, the processing advances to the step S 318 , thereby terminating this processing. 
   It is to be noted that in the present embodiment, there has been described the continuous photographing of three images by over, standard, and under exposures during the AEB continuous photographing. However, correction may be performed finer, and the number of images during the AEB continuous photographing may be three or more. 
   As described above, even during the AEB continuous photographing, the color and brightness of the pseudo shutter curtain are set in accordance with AEB brightness correction in the first, second, and third AEB photographing operations. That is, a black, gray, or white pseudo shutter curtain can be set so that it can be easily visually seen by the photographer. 
   Next, details of the camera signal processing circuit  5  are shown in  FIG. 4 . As shown in  FIG. 4 , in the present embodiment, the camera signal processing circuit  5  contains the pseudo shutter curtain generation circuit  5   b  and the synthesization circuit  5   a . The image data P 2  whose signal has been processed by the camera signal processing circuit  5  is once stored in the frame memory  7 , and returned again to the camera signal processing circuit  5  via the memory controller  6 . 
   The image data P 2 , and the pseudo shutter curtain signal P 3  output from the pseudo shutter curtain generation circuit  5   b  are synthesized in the synthesization circuit  5   a , and output to the liquid crystal driver  8 . In this case, the system controller  12  designates areas to be synthesized, and supplies information of a synthesization ratio to the synthesization circuit  5   a . Moreover, the controller supplies information of the color and brightness to the pseudo shutter curtain generation circuit  5   b , so that the brightness, the color, the synthesization ratio, and the areas to be synthesized can be varied. 
   Accordingly, when the color, brightness, and synthesization ratio of the pseudo shutter curtain are varied in accordance with the internal state of the digital camera, a movement of the object can be visually recognized by the photographer. For example, when the synthesization ratio of the pseudo shutter curtain and the photographed image is set to 50:50 during the continuous photographing, it is possible to solve a problem that the object is not easily recognized during the continuous still-image photographing. Especially the following problem can be solved: in recent years, the continuous photographing has been speeded up; therefore a time for which the object is covered with the pseudo shutter curtain and cannot be recognized increases, when the number of still images that can be photographed in one second increases; and consequently the visibility of the object is remarkably impaired in the high-speed continuous still-image photographing. 
   Moreover, even during the high-speed continuous photographing, the pseudo shutter curtain is generated for each photographing. Therefore, the photographer can easily grasp the time when the continuous photographing is completed, and it is possible to prevent the disadvantage that the last important scene could not photographed in the high-speed continuous still-image photographing. 
   Furthermore, since the color of the pseudo shutter curtain is changed to white, gray, black or the like in accordance with the brightness correction during the AEB continuous photographing, the photographer can visually recognize that the AEB continuous photographing is being performed. 
     FIG. 5  shows one example of display of the pseudo shutter curtain displayed in the liquid crystal panel  9 . 
   In areas A covered with pseudo shutter curtains  51 ,  52  in this screen, an image  53  to be photographed and the pseudo shutter curtains  51 ,  52  are synthesized at the synthesization ratio designated by the system controller  12 , and output. The synthesization is performed to output 100% of the image  53  to be photographed in an area B which is not covered with the pseudo shutter curtains  51 ,  52 . The synthesization circuit  5   a  operates to synthesize the pseudo shutter curtains  51 ,  52  and the image  53  to be photographed at the above-described ratio. 
   In the present embodiment, there have been specifically described the controls of the pseudo shutter curtain in the single photographing and the continuous photographing, and the AEB continuous photographing. During the continuous photographing, in a case where the number of photographed images comes close to the number of images that can be photographed, the control may be executed so that the photographer visually recognizes that the number of remaining images that can be photographed decreases. In the control, the color, brightness, and synthesization ratio of the pseudo shutter curtains  51 ,  52  displayed in the liquid crystal panel  9  are changed, and such changes of the displayed states of the pseudo shutter curtains  51 ,  52  are utilized without using character display. 
   As described above, when the number of the remaining images that can be photographed decreases during the continuous photographing, the color or the brightness of the pseudo shutter curtain is changed to allow the photographer to visually recognize that the continuous photographing comes to an end. 
   As described above, according to the image capture apparatuses of the first and second embodiments, the pseudo shutter curtain is generated every photographing even during the high-speed continuous photographing. Therefore, the photographer can easily grasp the time when the continuous photographing is completed, and it is possible to prevent the disadvantage that the last important scene could not be photographed during the high-speed continuous photographing. 
   Moreover, since the color of the pseudo shutter curtain is changed to white, gray, black or the like in accordance with the brightness correction during the AEB continuous photographing, the photographer can visually recognize that the AEB continuous photographing is being performed. 
   It is to be noted that in the above-described embodiment, the digital camera has been described. However, the image capture apparatus of the present invention is not limited to the digital camera, and includes a digital video camera, a cellular phone provided with a camera, and the like. 
   Another Embodiment of the Present Invention 
   Each means constituting the above-described image capture apparatus of each embodiment of the present invention, and each step of the method of controlling the image capture apparatus can be realized by operating a program stored in a RAM, a ROM or the like of a computer. This program, and a storage medium in which the program is recorded and which is readable by the computer are included in the present invention. 
   Moreover, the present invention may be embodied as, for example, a system, a device, a method, a program, a recording medium or the like. Specifically, the present invention may be applied to a system constituted of a plurality of units or a device constituted of one unit. 
   It is to be noted that the present invention also includes a case where the program of software for realizing the above-described function of each embodiment (programs corresponding to the flowcharts of  FIGS. 2 and 3  in the present embodiment) is supplied to the system or the device directly or via a remote area. In this case, the computer of the system or the device reads and executes a supplied program code. 
   Therefore, to realize functional processing of the present invention in the computer, the program code itself installed in the computer is realized by the present invention. That is, the present invention also includes the computer program itself for realizing the functional processing of the present invention. 
   In this case, a configuration such as a program to be executed by an object code or an interpreter, or script data to be supplied to OS may be used as long as the configuration has a program function. 
   Examples of the recording medium for supplying the program include a Floppy (registered trademark) disk, a hard disk, an optical disk, a magnetic optical disk, an MO, a CD-ROM, a CD-R, a CD-RW, a magnetic tape, a nonvolatile memory card, a ROM, and a DVD (DVD-ROM, DVD-R). 
   As another method of supplying the program, the program may be supplied by accessing an internet homepage by use of a browser of a client computer to download the computer program itself of the present invention or a compressed file including an automatic installing function from the homepage into a recording medium such as the hard disk. 
   Moreover, the supplying method can be realized by dividing the program code constituting the program of the present invention into a plurality of files to download the respective files from different homepages. That is, the present invention includes a WWW server for downloading, to a plurality of users, the program file for realizing the functional processing of the present invention in the present invention. 
   Furthermore, the supplying method can be realized by: encrypting the program of the present invention and storing the program in a storage medium such as the CD-ROM to distribute the program to the user; allowing the user who has cleared predetermined conditions to download key information for decrypting the program from the homepage via the internet; and executing the encrypted program by use of the key information to install the program in the computer. 
   Additionally, the above-described function of the embodiment is realized, when the computer executes the read program. Moreover, the function of the embodiment can be realized, when the OS operating in the computer performs a part or all of actual processing. 
   Furthermore, the function of the embodiment can be realized, when the program read from the recording medium is written in the memory disposed in a function extension board inserted into the computer or a function extension unit connected to the computer, and a CPU or the like disposed in the function extension board or the function extension unit performs a part or all of the actual processing based on an instruction of the program. 
   The above-described embodiments are merely exemplary of the present invention, and are not be construed to limit the scope of the present invention. 
   The scope of the present invention is defined by the scope of the appended claims, and is not limited to only the specific descriptions in this specification. Furthermore, all modifications and changes belonging to equivalents of the claims are considered to fall within the scope of the present invention. 
   This application claims priority from Japanese Patent Application No. 2004-381606 filed on Dec. 28, 2004, which is hereby incorporated by reference herein.