Abstract:
An image sensing apparatus having an image sensing mode for electrically sensing an object and storing an acquired image and a reproduction mode for reproducing and displaying the stored image includes a view angle changing unit for changing an angle of view of an image to be sensed in the image sensing mode and a magnification of an image to be displayed in the reproduction mode, a control unit that, in the reproduction mode, maintains the magnification of the image unchanged from before a start of operation of the view angle changing unit until an extent of operation of the view angle changing unit exceeds a preset first threshold value, and changes the magnification of the image depending on the extent of operation if the preset first threshold value is exceeded, and a display unit that displays a reproduction image at a magnification changed by the control unit.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to an image sensing apparatus for sensing, recording and reproducing still and moving images, and a control method therefor.  
       BACKGROUND OF THE INVENTION  
       [0002]     Conventionally, there is an image sensing apparatus having an image sensing mode and a reproduction mode as operating modes in which a zoom function in the image sensing mode and an enlarged image reproduction/magnification change in the reproduction mode have been assigned to the same control member. Specifically, in the reproduction mode, when a zoom control member is set to a telephoto side, a magnification of a display image is increased, and when the zoom control member is set to a wide-angle side, the magnification of the display image is decreased. In this manner, a user can perform a reproduction image enlargement designation operation with the same sensation as when performing a zoom operation during image sensing, and for this reason amounts to an instinctively easy-to-understand user interface.  
         [0003]     Additionally, a multi-image reproduction function has been proposed that can display a plurality of reduced images on a single display screen and select the image that the user wishes to display in the full screen size when the zoom control member is moved to the wide-angle side (for example, Japanese Patent Application Laid-Open No. 11-308490).  
         [0004]     A speedy response to user operations is required of the zoom operation in the image sensing mode, as is the ability to precisely adjust the position of the zoom and to respond sensitively to user operations. At the same time, however, because the zoom responds with the same speed as the zoom operation in the image sensing mode if the zoom control member is touched inadvertently during image reproduction in the reproduction mode, a display operation that is unsatisfactory to the user is executed. Accordingly, a first drawback of the conventional art arises if the zoom operation in the reproduction mode is performed with the same sensitive response as the zoom operation in the image sensing mode, in that a user interface in the reproduction mode that is satisfactory to the user cannot be provided.  
         [0005]     Moreover, when performing multi-image reproduction in the reproduction mode, processing time increases because a plurality of recorded images are scanned from a storage medium and displayed. Therefore, a second drawback arises if the zoom control member is touched inadvertently, in that the apparatus becomes unable to accept user operations while performing the multi-image reproduction.  
         [0006]     Further, a third drawback arises in that, when a zoom ring is used as the zoom control member, users often mistakenly rotate the zoom ring in the wrong direction, with the result that, if the zoom ring is mistakenly rotated in the wide-angle direction during full screen size image display, or if the zoom ring is mistakenly rotated by a great amount in the wide-angle direction during magnified display, the apparatus shifts to the multi-image reproduction process against the wishes of the user and the user must then wait for the process to be completed.  
       SUMMARY OF THE INVENTION  
       [0007]     The present invention has been made in consideration of the above-described situation, and has as its object to improve the operability of the image sensing apparatus by performing image enlargement and reduction display control according to the operating mode.  
         [0008]     According to the present invention, the foregoing object is attained by providing an image sensing apparatus having an image sensing mode for electrically sensing an object and storing acquired image data on a storage medium and a reproduction mode for reproducing and displaying the stored image, the apparatus comprising: a view angle changing unit for designating an angle of view of an image to be sensed in the image sensing mode and a magnification of an image to be displayed in the reproduction mode; a control unit that, in the reproduction mode, maintains the magnification of the image at a value prior to a start of operation of the view angle changing unit since the start of operation until an extent of operation of the view angle changing unit exceeds a preset first threshold value, and changes the magnification of the image depending on the extent of operation if the first threshold value is exceeded; and a display unit that displays a reproduction image at a magnification changed by the control unit.  
         [0009]     According to the present invention, the foregoing object is also attained by providing a method of controlling an image sensing apparatus having an image sensing mode for electrically sensing an object and storing acquired image data on a storage medium and a reproduction mode for reproducing and displaying the stored image, a view angle changing unit for setting an angle of view of an image to be sensed in the image sensing mode and a magnification of an image to be displayed in the reproduction mode, and a display unit that displays a reproduction image, the control method comprising: determining an operating mode of the image sensing apparatus; detecting an operating state of the view angle changing unit; in the reproduction mode, maintaining a view angle of the image at a value prior to a start of operation of the view angle changing unit since the start of operation until an extent of operation of the view angle changing unit exceeds a preset first threshold value, and changing a magnification of the image depending on the extent of operation when the first threshold value is exceed; and displaying a reproduction image at the display unit at a magnification changed in the controlling.  
         [0010]     Other features and advantages of the present invention will be apparent from the following description when 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  
       [0011]     The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.  
         [0012]      FIG. 1  is a block diagram showing the structure of an image processing apparatus according to a first embodiment of the present invention;  
         [0013]      FIG. 2  is a flow chart showing the overall operation of a zoom process in an image sensing mode according to the first embodiment of the present invention;  
         [0014]      FIG. 3  is a flow chart showing details of a zoom drive determination process according to the first embodiment of the present invention;  
         [0015]      FIGS. 4A and 4B  are flow charts showing the overall operation of an enlarged reproduction process in a reproduction mode according to the first embodiment of the present invention;  
         [0016]      FIG. 5  is a flow chart showing details of an enlarged reproduction determination process according to the first embodiment of the present invention;  
         [0017]      FIG. 6  is a block diagram showing the structure of an image processing apparatus according to a second embodiment of the present invention;  
         [0018]      FIG. 7  is a flow chart showing the overall operation of a zoom process in an image sensing mode according to the second embodiment of the present invention;  
         [0019]      FIG. 8  is a flow chart showing details of a zoom drive determination process according to the second embodiment of the present invention;  
         [0020]      FIGS. 9A and 9B  are flow charts showing the overall operation of an enlarged reproduction process in a reproduction mode according to the second embodiment of the present invention;  
         [0021]      FIG. 10  is a flow chart showing details of an enlarged reproduction determination process according to the second embodiment of the present invention; and  
         [0022]      FIG. 11  is a flow chart showing details of a multi-image reproduction determination process according to the second embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0023]     Preferred embodiments of the present invention are now described in detail in accordance with the accompanying drawings. However, it should be understood that the dimensions, materials, shapes and relative positions of the constituent parts shown in the embodiments should be changed as convenient depending on various conditions and on the structure of the apparatus adapted to the invention, and the invention is not limited to the embodiments described herein.  
       First Embodiment  
       [0024]      FIG. 1  is a block diagram showing the structure of an image processing apparatus according to a first embodiment of the present invention.  
         [0025]     In  FIG. 1 , reference numeral  100  denotes the image processing apparatus according to the present embodiment. The image processing apparatus  100  may be any of a digital camera, a digital video camera, and a camera-equipped portable terminal (including a cell phone equipped with a camera.) In the present embodiment, the image processing apparatus  100  is assumed to be a digital camera.  
         [0026]     In the image sensing apparatus  100 ,  10  denotes an image sensing lens;  12 , a shutter having a diaphragm function;  14 , an image sensing device which converts an optical image into an electric signal;  16 , an A/D converter which converts an analog signal output from the image sensing device  14  into a digital signal.  
         [0027]     Numeral  18  denotes a timing generator which supplies a clock signal and a control signal respectively to the A/D converter  16  and a D/A converter  26 , under the control of a memory controller  22  and a system controller  50 .  
         [0028]     Numeral  20  denotes an image processor which performs predetermined pixel interpolation processing, color conversion processing and the like on image data from the A/D converter  16  or image data from the memory controller  22 . The image processor  20  performs predetermined calculation processing using the image data outputted from the A/D converter  16 , and the system controller  50  performs through-the-lens (TTL) auto focus (AF) processing, auto exposure (AE) processing, pre-flash (EF) processing with respect to an exposure controller  40  and a distance measurement controller  42 , based on the result of calculations. Further, the image processor  20  performs predetermined calculation using the image data outputted from the A/D converter  16 , and performs TTL auto white balance (AWB) processing, based on the result of calculations.  
         [0029]     The memory controller  22  controls the A/D converter  16 , the timing generator  18 , the image processor  20 , an image display memory  24 , the D/A converter  26 , a memory  30  and a compression/expansion circuit  32 . The image data outputted from the A/D converter  16  is written into the image display memory  24  or the memory  30  via the image processor  20  and the memory controller  22 , or only via the memory controller  22 .  
         [0030]     Numeral  24  denotes the image display memory;  26 , a D/A converter; and  28 , an image display unit comprising an LCD or the like. Image data written into the image display memory  24  is displayed on the image display unit  28  via the D/A converter  26 .  
         [0031]     An electronic finder function is realized by sequentially display obtained images on the image display unit  28 . Further, image display unit  28  arbitrarily turns ON/OFF its display, in accordance with an instruction from the system controller  50 . If the display is turned OFF, the electric consumption of the image processing apparatus  100  can be greatly reduced. The image display unit  28  also displays information on a focus state, a camera shake warning, a flash charge state, the shutter speed, the f number (aperture), and the exposure compensation in accordance with an instruction from the system controller  50 .  
         [0032]     The memory  30 , used for storing obtained still images and moving images, has a sufficient storage capacity for storing a predetermined number of still images and a moving image for a predetermined period. In sequential image sensing to sequentially obtain a plural number of still images or panoramic images sensing, a large amount of image data can be written into the memory  30  at a high speed. Further, the memory  30  may be used as a work area for the system controller  50 .  
         [0033]     The compression/expansion circuit  32  compresses or expands image data by adaptive discrete cosine transformation (ADCT) or the like. The compression/expansion circuit  32  reads image data stored in the memory  30  and performs compression or expansion processing on the read image data, and writes the processed data into the memory  30 .  
         [0034]     The exposure controller  40  controls the shutter  12  having the diaphragm function. The exposure controller  40  interlocked with a flash  48  also has a flash adjusting function. The distance measurement controller  42  controls focusing of the image sensing lens  10 . Numeral  44  denotes a zoom controller which controls zooming of the image sensing lens  10 . Numeral  102  denotes a zoom ring which incorporates an encoder and outputs a pulse signal in response to a rotation of the zoom ring  102 ;  46 , a ring rotation sensor which detects the direction and angle of the rotation of the zoom ring  102  in accordance with the output signal from the encoder of the zoom ring  102 ; and  48 , the flash which has an AF auxiliary light projection function and a flash adjusting function. The system controller  50  controls the exposure controller  40  and the distance measurement controller  42  by the TTL method, in accordance with the result of calculations by the image processor  20  based on the image data from the A/D converter  16 .  
         [0035]     The system controller  50  controls the overall image sensing apparatus  100 . Memory  52  stores the constants, variables, and programs for operation of the system controller  50 .  
         [0036]     Numeral  54  denotes a notification unit which notifies operating statuses, messages and the like to the outside by using characters, images, sound and the like, in correspondence with execution of program by the system controller  50 . The notification unit  54  comprises one or more combinations of display devices including an LCD and an LED for visual notification and sound generating devices for audio notification. Especially, the display device or devices is/are provided in a single or plural visually-recognizable positions around an operation unit  70  of the image processing apparatus  100 . Further, a part of functions of the notification unit  54  is provided within an optical finder  104 .  
         [0037]     The display contents of the notification unit  54 , displayed on the LCD or the like, include indication of single shot/sequential image sensing, a self timer, a compression rate, the number of recording pixels, the number of recorded images, the number of recordable images, a shutter speed, an f number (aperture), exposure compensation, flash illumination, pink-eye effect mitigation, macro image sensing, a buzzer-set state, a timer battery level, a battery level, an error state, information of plural digit numbers, attached/detached status of recording media  200  and  210 , operation of communication I/F, and date and time.  
         [0038]     Further, the display contents of the notification unit  54 , displayed within the optical finder  104 , include a focus state, a camera shake warning, a flash charge state, the shutter speed, the f number (aperture), and the exposure compensation.  
         [0039]     Numeral  56  denotes an electrically erasable and recordable nonvolatile memory such as an EEPROM.  
         [0040]     Numerals  60 ,  62 ,  64 ,  66 ,  68  and  70  denote operation means for inputting various operation instructions to the system controller  50 , comprising a single or plurality of combinations of switches, dials, touch panels, a device for pointing by line-of-sight detection, a voice recognition device, and the like. The subsystem controller  52  detects the operation content and transmits the content to the system controller  50  by communication.  
         [0041]     Next, the operation means will be described in more detail.  
         [0042]     Numeral  60  denotes a mode dial switch for selecting various function modes such as a power OFF mode, an automatic image sensing mode, an image sensing mode, a panoramic image sensing mode, a reproduction mode, a multi-image reproduction/deletion mode, and a PC connection mode.  
         [0043]     Numeral  62  denotes a shutter switch SW 1  turned ON by half stroke of a shutter button (not shown), to instruct start of the operations of the AF processing, the AE processing, the AWB processing, the EF processing and the like.  
         [0044]     Numeral  64  denotes a shutter switch SW 2  turned ON by full stroke of the shutter button (not shown), to instruct start of a series of operations of exposure processing to write a signal read from the image sensing device  14  into the memory  30 , via the A/D converter  16  and the memory controller  22 , development processing by using calculations by the image processor  20  and the memory controller  22 , and recording processing to read the image data from the memory  30 , compress the image data by the compression/expansion circuit  32 , and write the compressed image data into the recording medium  200  or  210 .  
         [0045]     An enlarged display switch  66  instructs to enlarge a reproduction image by JPEG method and display the enlarged image. When it is operated during a multi-reproduction mode, a selected image is displayed in the full screen size.  
         [0046]     A multi-image reproduction switch  68  instructs to reduce a magnification ration ratio of a reproduction image and display the reduced image. When it is operated during displaying an image in the full screen size, the mode is shifted to the multi-image reproduction mode in which a plurality of thumbnail images are displayed on a single display screen.  
         [0047]     Numeral  70  denotes an operation unit comprising various buttons and touch panels including a menu button, a set button, a macro/non-macro selection button, a multi-image reproduction/repaging button, a quick review on/off button, a flash setting button, a single-shot/sequential/self-timer image sensing selection button, a forward (+) menu item selection button, a backward (−) menu item selection button, a forward (+) reproduction image search button, a backward (−) reproduction image search button, an image sensing quality selection button, an exposure correction button, and a date/time set button.  
         [0048]     Numeral  80  denotes a power controller comprising a battery detection circuit, a DC-DC converter, a switch circuit to select the block to be energized and the like. The power controller  80  detects the attached/detached state of the battery, the battery type and the remaining battery power level, controls the DC-DC converter based on the results of detection and an instruction from the system controller  50 , and supplies a necessary voltage to the respective parts including the recording medium for the necessary period.  
         [0049]     Numerals  82  and  84  denote connectors; and  86 , the power source comprising a primary battery such as an alkaline battery or a lithium battery, a secondary battery such as an NiDd battery, an NiMH battery or an Li battery, an AC adapter, and the like.  
         [0050]     Numerals  90  and  94  denote interfaces for recording media such as a memory card or a hard disk; and  92  and  96 , connectors for connection with the recording media such as a memory card or a hard disk. A recording medium attached/detached state detector  98  detects whether recording medium  200  and/or  210  is attached to the connector  92  and/or connector  96 .  
         [0051]     In the present embodiment, two systems of interfaces and connectors for connection with the recording media are employed. However, the number of systems is not limited, and a single or plurality of systems of interfaces and connectors may be provided. Further, interfaces and connectors pursuant to different standards may be combined.  
         [0052]     As the interfaces and connectors, cards in conformity with Personal Computer Memory Card International Association standards (PCMCIA cards) and cards in conformity with compact flash© (CF) card standards may be used. In a case where cards and connectors in conformity with the PCMCIA standards, CF card standards and the like are used as the interfaces  90  and  94  and the connectors  92  and  96 , image data and management information attached to the image data are transmitted/received with respect to other peripheral devices such as a computer and a printer by connection with various communication cards such as a LAN card, a modem card, a USB card, an IEEE 1394 card, a P1284 card, an SCSI card and a PHS card.  
         [0053]     The optical finder  104  can be used for image sensing without the electronic finder function by the image display unit  28 . In the optical finder  104 , realized are some of the functions of the notification unit  54  including the indication of focus state, the camera shake warning, the flash charge state, the shutter speed, the f number (aperture), the exposure compensation and the like.  
         [0054]     A communication unit  110  has various communication functions for RS232C, USB, IEEE 1394, P1284, SCSI, modem, LAN, and wireless communication. A connector/antenna  112  functions as a connector when the image processing apparatus  100  is connected to another device via the communication unit  110 , and as an antenna for wireless communication.  
         [0055]     The recording media  200  and  210  comprise memory cards, hard disks or the like. The recording media  200  and  210  have recording units  202  and  212  of a semiconductor memory, a magnetic disk or the like, the interfaces  204  and  214  for communication with the image processing apparatus  100 , and the connectors  206  and  216  for connection with the image processing apparatus  100 , respectively.  
         [0056]     Next, a description is given of the operation of the image processing apparatus  100  having the structure described above according to the first embodiment of the present invention, with reference to FIGS.  1  to  5 .  
         [0057]      FIG. 2  is a flow chart showing the overall operation of a zoom process according to an image sensing mode of the first embodiment of the present invention.  
         [0058]     In step S 201 , the ring rotation sensor  46  detects a pulse signal output from the encoder of the zoom ring  102 , thus detecting the start of rotation of the zoom ring  102 . When the start of rotation of the zoom ring  102  is detected, in step S 202  it is determined if the direction of rotation of the zoom ring  102  is in the telephoto direction (zoom-in) or in the wide-angle direction (zoom-out). If the direction of rotation of the zoom ring  102  is in the telephoto direction, then processing proceeds to step S 203 , where it is determined whether or not the zoom position is at the extreme telephoto end. If the direction of rotation of the zoom ring  102  is in the wide-angle direction, then processing proceeds to step S 204 , where it is determined whether or not the zoom position is at the extreme wide-angle end.  
         [0059]     If the zoom position is at the telephoto end or the wide-angle end, processing returns to step S 201 . If the zoom position is not at either the telephoto end or the wide-angle end, then processing proceeds to step S 205 , where it is determined whether or not to begin zoom drive.  
         [0060]      FIG. 3  is a flow chart showing details of a zoom drive determination process according to the first embodiment of the present invention, specifically, of the zoom drive determination process performed in step S 205 .  
         [0061]     First, in step S 301 , the zoom drive flag is initialized to OFF. Next, in step S 302 , it is determined whether or not the angle of rotation since the start of rotation of the zoom ring  102  has exceeded a preset reference angle of rotation R 1 , and, if the angle of rotation has exceeded R 1 , in step S 303  the zoom drive flag is turned ON, starting the zoom drive. It should be noted that, in the image sensing mode, it is necessary that the zoom operation responds speedily and sensitively to user operations in order not to miss a shot, and as a result it is preferable to set the reference angle of rotation R 1  at a very small value. If the rotation of the zoom ring  102  is stopped (YES in step S 304 ) before the angle of rotation since the start of rotation of the zoom ring  102  exceeds the reference angle of rotation R 1  (NO in step S 302 ), then the zoom drive flag is left in the state in which it was set in step S 301  (that is, OFF).  
         [0062]     If as a result of the zoom drive determination process in step S 205  described above the drive start conditions are satisfied, that is, if the zoom drive flag is ON (YES in step S 206 ), then in step S 207  the direction of rotation of the zoom ring  102  is determined. If the direction of rotation of the zoom ring  102  is in the telephoto direction, then processing proceeds to step S 208  and the zoom position is moved to the telephoto side. If the direction of rotation of the zoom ring  102  is in the wide-angle direction, then processing proceeds to step S 209  and the zoom position is moved to the wide-angle side. It should be noted that, in steps S 208  and S 209 , the zoom position is moved in response to the rotation operation from the time when the zoom drive flag is turned ON (that is, from the time when the reference angle of rotation R 1  is reached).  
         [0063]     In step S 206 , if the drive start conditions are not satisfied, that is, if the zoom drive flag is OFF, then processing returns to step S 201  without performing zoom drive.  
         [0064]     If during zoom drive a halt in rotation of the zoom ring  102  is detected (YES in step S 210 ), then in step S 212  the zoom drive is stopped. Also, if the zoom position reaches the telephoto end or the wide end (YES in step S 211 ) without a halt in rotation of the zoom ring  102  (NO in step S 210 ), then processing proceeds to step S 212  and zoom drive is stopped.  
         [0065]      FIGS. 4A and 4B  are flow charts showing the overall operation of an enlarged reproduction process in the reproduction mode according to the first embodiment of the present invention.  
         [0066]     First, in step S 401 , it is detected if any of either the enlarged display switch  66 , the multi-image reproduction switch  68  or the zoom ring  102  has been operated. If an operation is detected the process proceeds to step S 402 , where it is determined which operation has been detected. Here, a description is given of the process of switching among image reproduction, enlarged reproduction and multi-image reproduction by the enlarged display switch  66  and multi-image reproduction switch  68 .  
         [0067]     If in step S 402  operation of the enlarged display switch  66  is detected, processing then proceeds to step S 412  where it is determined whether or not the apparatus is in multi-image reproduction. If the apparatus is not in multi-image reproduction but in single-image reproduction, then processing proceeds to step S 413  where it is determined whether or not the magnification of the displayed image is at maximum. If the image displayed is at maximum magnification, then processing returns to step S 401  because further enlarged display is not possible. By contrast, if the image displayed is not at maximum magnification, then the apparatus performs JPEG expansion of the reproduction image in step S 415  and display is enlarged. Additionally, if it is determined in step S 412  that the apparatus is in multi-image reproduction, then of the plurality of images being displayed, an image being selected is displayed at full screen size magnification.  
         [0068]     If in step S 402  operation of the multi-image reproduction switch  68  is detected, processing then proceeds to step S 416  where it is determined whether or not the apparatus is in multi-image reproduction. If the apparatus is in multi-image reproduction, then processing returns to step S 401  without changing the display. By contrast, if the apparatus is not in multi-image reproduction but in single-image reproduction, then processing proceeds to step S 417 , where it is determined if the image being displayed is at full screen size magnification. If the image is displayed in the full screen size, then processing proceeds to step S 419  and the apparatus performs multi-image reproduction. If the image is not displayed at a full screen size magnification, then an enlarged image is displayed, and therefore in step S 418  the enlarged magnification is reduced and a single reduced image is displayed.  
         [0069]     Next, a process of switching between image reproduction and enlarged reproduction using the zoom ring  102  is described.  
         [0070]     If in step S 402  operation of the zoom ring  102  is detected, processing then proceeds to step S 403  where it is determined whether or not the apparatus is in multi-image reproduction. If the apparatus is in multi-image reproduction, then processing returns to step S 401  without changing the display. That is, a change in the display from multi-image reproduction display to single-image display by operation of the zoom ring  102  is not performed.  
         [0071]     By contrast, if the apparatus is not in multi-image reproduction (that is, the apparatus is in single-image display), the process proceeds to step S 404  and the direction of rotation of the zoom ring  102  is detected. If the direction of rotation of the zoom ring  102  is toward telephoto, then processing proceeds to step S 405  and it is determined whether or not the zoom magnification of the image being displayed is at maximum. If the image displayed is not at maximum magnification, then processing proceeds to step S 407 . If the image displayed is at maximum magnification, then processing returns to step S 401  because further enlarged display is not possible. By contrast, if the direction of rotation of the zoom ring  102  is toward wide-angle, processing then proceeds to step S 406  and it is determined whether or not the zoom magnification is full screen size magnification. If the zoom magnification is not full screen size magnification, then processing proceeds to step S 407 . If the zoom magnification is full screen size magnification, then processing returns to step S 401 . Thus, as the foregoing indicates, a change in the display from single-image display to multi-image reproduction by operation of the zoom ring  102  is not performed.  
         [0072]     In step S 407 , an enlarged reproduction determination process is performed. A description is now given of the enlarged reproduction determination process in the first embodiment of the present invention, with reference to  FIG. 5 .  
         [0073]      FIG. 5  is a flow chart showing details of an enlarged reproduction determination process according to the first embodiment of the present invention.  
         [0074]     First, in step S 501 , the enlarged reproduction flag is initialized to OFF. In step S 502 , a monitor timer that measures a period of time since the start of rotation of the zoom ring  102  starts. Next, in step S 503 , it is determined whether or not the angle of rotation of the zoom ring  102  has exceeded a preset reference angle of rotation R 2 . If the angle of rotation of the zoom ring  102  has exceeded the preset reference angle of rotation R 2  (YES in step S 503 ), then the enlarged reproduction flag is turned ON so as to perform enlarged display (step S 505 ). Processing is ended after the monitor timer is stopped in step S 506 .  
         [0075]     It should be noted that the reference angle of rotation R 2  used in the enlargement determination process in the reproduction mode is set greater than the reference angle of rotation R 1  used in the zoom drive determination process in the image sensing mode. The reason for such a setting arrangement is that, in contrast to the necessity for sensitive reaction to user operation during zoom operation in the image sensing mode, the necessity for sensitive reaction to user operations is less in the reproduction mode than in the image sensing mode because the reproduction mode involves the reproduction of already recorded images. Conversely, if the reproduction mode operated with the same speedy response as the image sensing mode, the user might unintentionally perform an enlargement operation if, for example, the user has inadvertently touched the zoom ring, resulting in an unsatisfactory display operation for the user. Therefore, by setting R 2  at a value greater than R 1 , the extent of driving of the zoom ring  102  until the start of a zoom operation can be made greater in the reproduction mode than in the image sensing mode, so that the possibility of the user performing an unintentional zoom operation if the zoom ring  102  is inadvertently moved can be reduced.  
         [0076]     By contrast, if the angle of rotation of the zoom ring  102  is less than R 2  (NO in step S 503 ), in step S 504  it is determined whether or not the rotation of the zoom ring  102  has stopped. If the rotation has not stopped, then in step S 507  it is determined whether or not the monitor timer has exceeded a preset time-out time T 1 , and, if the preset time-out has not been exceeded, processing returns to step S 503  and the detection of the angle of rotation is repeated. By contrast, if the angle of rotation of the zoom ring  102  has not exceeded the reference angle of rotation R 2  within the time-out time T 1  since the start of rotation of the zoom ring  102  (NO in step S 503 ), and further, if the rotation of the zoom ring  102  has stopped (YES in step S 504 ), then the enlarged reproduction determination process is ended after the monitor timer is stopped in step S 506 . As a result, the enlarged reproduction flag set in step S 501  remains OFF.  
         [0077]     Additionally, even if rotation of the zoom ring  102  continues and the zoom ring  102  angle of rotation has not reached the reference angle of rotation R 2  within the time-out time T 1  since the start of rotation (YES in step S 507 ), if rotation of the zoom ring  102  is continued until the angle of rotation of the zoom ring  102  exceeds a separate reference angle of rotation R 3  (NO in step S 509 , YES in step S 508 ), then the enlarged reproduction flag is set to ON in step S 510  so as to perform enlarged reproduction, and after the monitor timer is stopped in step S 506  the enlarged reproduction determination process is ended.  
         [0078]     It should be noted that the reference angle of rotation R 3  is set greater than the reference angle of rotation R 2 .  
         [0079]     By contrast, if rotation of the zoom ring  102  is stopped (YES in step S 509 ) without the angle of rotation of the zoom ring  102  exceeding the reference angle of rotation R 3  (NO in step S 508 ), processing then proceeds to step S 506  and, after the monitor timer is stopped, the enlarged reproduction determination process is ended. As a result, the enlarged reproduction flag set in step S 501  remains OFF, and enlarged reproduction is not performed.  
         [0080]     If as a result of the enlarged reproduction determination process in step S 407  described above the drive start conditions are not satisfied (NO in step S 408 ), that is, if the enlarged reproduction flag is OFF, processing returns to step S 401  without performing enlarged reproduction.  
         [0081]     On the other hand, if the drive start conditions are satisfied, that is, if the enlarged reproduction flag is ON (YES in step S 408 ), then in step S 409  the direction of rotation of the zoom ring  102  is detected. If the direction of rotation of the zoom ring  102  is toward the telephoto side, then processing proceeds to step S 410 , where the reproduction image is JPEG expanded, enlarged and displayed. If the direction of rotation of the zoom ring  102  is toward the wide-angle side, processing then proceeds to step S 411 , where the magnification is reduced and a single image is displayed. It should be noted that, in steps S 410  and S 411 , the magnification is determined according to the rotation operation from the time the zoom drive flag is turned ON (that is, since reaching reference angle of rotation R 2  or R 3 ).  
         [0082]     After step S 410  or S 411 , processing returns to step S 404  and the process described above is repeated. By so doing, if the enlargement magnification is maximized as a result of moving the zoom ring  102  further in the telephoto direction, if the enlargement magnification becomes full screen size magnification by moving the zoom ring  102  further in the wide-angle direction, or if the rotation of the zoom ring  102  has stopped, the enlarged reproduction process is stopped and processing returns to step S 401 .  
         [0083]     According to the first embodiment described above, by setting the reference angle of rotation R 1  of the zoom ring  102  at a very small value in the image sensing mode, the driving of the zoom can be started promptly in response to the rotation of the zoom ring  102 . At the same time, if in the reproduction mode the angle of rotation is rotated at or above a fixed angular velocity (R 2 /T 1 , R 2 &gt;R 1 ), or if rotated greatly though at a slow angular velocity (angle of rotation&gt;R 3 ), the apparatus determines that enlarged reproduction is to be performed, and as a result the possibility that the user might perform an unintentional zoom operation by inadvertently moving the zoom ring  102  can be reduced.  
         [0084]     Additionally, by configuring the apparatus so that, in the reproduction mode, the shift from multi-image reproduction display to single-image reproduction display and the shift from single-image reproduction display to multi-image reproduction display are accomplished by special switch operations and cannot be accomplished by zoom ring operation, the performance of an unintended multi-image reproduction process by inadvertent operation of the zoom ring can be prevented.  
         [0085]     It should be noted that, although in the first embodiment described above, the image sensing mode determination logic ( FIG. 3 ) and the reproduction mode determination logic ( FIG. 5 ) are described as being separate, alternatively, a single determination logic may be used and different values for each mode may be used for the reference angle of rotation and monitor timer.  
         [0086]     Additionally, although in the first embodiment described above the zoom drive control is provided or not depending on the angle of rotation of the zoom ring even in the image sensing mode, alternatively such operation may not be performed in the image sensing mode.  
       Second Embodiment  
       [0087]     Next, a description is given of a second embodiment of the present invention.  
         [0088]      FIG. 6  is a block diagram showing the structure of an image processing apparatus according to a second embodiment of the present invention. Structures in  FIG. 6  identical to those in  FIG. 1  have identical reference numerals, and a duplicate description thereof is omitted here.  
         [0089]     Reference numeral  105  denotes a zoom lever that can be moved both left and right from a center position and is used for zoom, enlarged reproduction, reduced reproduction, and multi-image reproduction operations. A voltage at the AD converter  106  changes depending on how much the lever is operated, and the changed voltage is reported to the system controller  50 . The zoom lever  105  and the A/D converter  106  are provided instead of the enlarged display switch  66 , the multi-image reproduction switch  67 , the zoom ring  102  and the ring rotation sensor shown in  FIG. 1 . The system controller  50  performs processing control based on the voltage value reported from the A/D converter  106 . It should be noted that a possible range of operation of the zoom lever  105  is a range from −A to +A, with 0 as the center position.  
         [0090]     Next, a description is given of the operation of an image processing apparatus  100 ′ having the structure shown in  FIG. 6  according to the second embodiment of the present invention, with reference to FIGS.  6  to  11 .  
         [0091]      FIG. 7  is a flow chart showing the overall operation of a zoom process in an image sensing mode according to the second embodiment of the present invention.  
         [0092]     In step S 701 , the system controller  50  detects a start of operation of the zoom lever  105  based on the voltage value from the A/D converter  106 . When the start of operation of the zoom lever  105  is detected, in step S 702  the system controller  50  determines if the zoom lever  105  has been operated in the telephoto direction (zoom-in) or in the wide-angle direction (zoom-out). If the zoom lever  105  has been operated in the telephoto direction, then processing proceeds to step S 703  and the system controller  50  determines whether or not the zoom position is at the extreme telephoto end. If the zoom lever  105  has been operated in the wide-angle direction, processing then proceeds to step S 704  and the system controller  50  determines whether or not the zoom position is at the extreme wide-angle end.  
         [0093]     If the zoom position is at either the extreme telephoto end or the extreme wide-angle end, then processing returns to step S 701 . If the zoom position is not at either the telephoto end or the wide-angle end, then processing proceeds to step S 705  and the system controller  50  determines whether or not to start the zoom drive.  
         [0094]      FIG. 8  is a flow chart showing details of a zoom drive determination process according to the second embodiment of the present invention, specifically the zoom drive determination process performed in step S 705 .  
         [0095]     First, in step S 801 , the zoom drive flag is initialized to OFF. Next, in step S 802 , it is determined whether or not an extent of operation since the start of operation of the zoom lever  105  has exceeded a preset reference operation extent V 1 , and, if the extent of operation has exceeded V 1 , in step S 803  the zoom drive flag is turned ON, starting the zoom drive. It should be noted that, in the image sensing mode, it is necessary that the zoom operation respond speedily and sensitively to user operations in order not to miss a shot, and as a result it is preferable to set the reference operation extent V 1  at a very small value. By contrast, if the extent of operation of the zoom lever  105  is stopped (YES in step S 804 ) before the extent of operation since the start of operation of the zoom lever  105  exceeds the reference operation extent V 1  (NO in step S 802 ), then the zoom drive flag is left in the state in which it was set in step S 801  (that is, OFF).  
         [0096]     If as a result of the zoom drive determination process in step S 705  described above the drive start conditions are satisfied, that is, if the zoom drive flag is ON (YES in step S 706 ), then in step S 707  the direction of operation of the zoom lever  105  is determined. If the direction of operation of the zoom lever  105  is in the telephoto direction, then processing proceeds to step S 708  and the zoom position is moved to the telephoto side. If the direction of operation of the zoom lever  105  is in the wide-angle direction, then processing proceeds to step S 709  and the zoom position is moved to the wide-angle side. It should be noted that, in steps S 708  and S 709 , the zoom position is moved in response to the operation from the time when the zoom drive flag is turned ON (that is, from the time when the reference operation extent V 1  is reached).  
         [0097]     If in step S 706  the drive start conditions are not satisfied, that is, if the zoom drive flag is OFF, then processing returns to step S 701  without performing zoom drive.  
         [0098]     If during zoom drive a halt in operation of the zoom lever  105  is detected (YES in step S 710 ), then in step S 712  the zoom drive is stopped. Also, if the zoom position reaches the telephoto end or the wide end (YES in step S 711 ) without a halt in operation of the zoom lever  105  (NO in step S 710 ), the process proceeds to step S 712  and zoom drive is stopped.  
         [0099]      FIGS. 9A and 9B  are flow charts showing the overall operation of an enlarged reproduction process in the reproduction mode according to the second embodiment of the present invention.  
         [0100]     First, in step S 901 , the system controller  50  detects a start of operation of the zoom lever  105  based on the voltage value from the A/D converter  106 . When the start of operation of the zoom lever  105  is detected, in step S 902  the system controller  50  determines if the zoom lever  105  has been operated in the telephoto direction or in the wide-angle direction. If the zoom lever  105  has been operated in the telephoto direction, then processing proceeds to step S 903 . If the zoom lever  105  has been operated in the wide-angle direction, processing then proceeds to step S 904 . In either case, the system controller  50  then determines whether or not the apparatus is in the process of multi-image reproduction.  
         [0101]     First, however, a description is given of the operation performed when the direction of operation is toward the telephoto side.  
         [0102]     If in step S 903  it is determined that the apparatus is not in the process of multi-image reproduction but is instead in the process of single-image display, then processing proceeds to step S 905 , where it is determined whether or not the magnification of the image being displayed is at maximum. If the magnification is at maximum, then processing returns to step S 901  because further enlarged display is not possible. By contrast, if the image displayed is not at maximum magnification, then processing proceeds to step S 908  and where the enlarged reproduction determination process is performed.  
         [0103]     Here, a description is given of the enlarged reproduction determination process of the second embodiment performed in step S 908 , with reference to  FIG. 10 .  
         [0104]      FIG. 10  is a flow chart showing details of an enlarged reproduction determination process according to the second embodiment of the present invention.  
         [0105]     First, in step S 1001 , the enlarged reproduction flag is initialized to OFF. In step S 1002 , a monitor timer that measures a period of time since the start of operation of the zoom lever  1005  is started. Next, in step S 1003 , it is determined whether or not the extent of operation of the zoom lever  105  has exceeded a preset reference operation extent V 2 . If the extent of operation of the zoom lever  105  has exceeded the preset reference operation extent V 2  (YES in step S 1003 ), then the enlarged reproduction flag is set to ON so as to perform enlarged reproduction (step S 1005 ). Processing is ended after the monitor timer is stopped in step S 1006 .  
         [0106]     It should be noted that the reference operation extent V 2  used in the enlargement determination process in the reproduction mode is set greater than the reference operation extent V 1  used in the zoom drive determination process in the image sensing mode. The reason for such a setting arrangement is the same as that for setting the reference angle of rotation R 2  greater than the reference angle of rotation R 1  in the first embodiment described above.  
         [0107]     By contrast, if the extent of operation of the zoom lever  105  is less than V 2  (NO in step S 1003 ), in step S 1004  it is determined whether or not the operation of the zoom lever  105  has stopped. If the operation has not stopped, then in step S 1007  it is determined whether or not the monitor timer has exceeded a preset time-out time T 1 , and, if not, processing returns to step S 1003  and the detection of the extent of operation is repeated. By contrast, if the extent of operation of the zoom lever  105  has not exceeded the reference operation extent V 2  within the time-out time T 1  since the start of operation of the zoom lever  105  (NO in step S 1003 ), and further, if the operation of the zoom lever  105  has stopped (YES in step S 1004 ), then the enlarged reproduction determination process is ended after the monitor timer is stopped in step S 1006 . As a result, the enlarged reproduction flag set in step S 1001  remains OFF.  
         [0108]     Additionally, if the operation of the zoom lever  105  continues (NO in step S 1004 ) and the monitor timer exceeds the time-out time T 1  (YES in step S 1007 ), then in step S 1008  the enlarged reproduction flag is set to ON so as to perform enlarged reproduction. Thereafter, in step S 1006 , processing is ended after the monitor timer is stopped.  
         [0109]     If as a result of the enlarged reproduction determination process in step S 908  described above the drive start conditions are not satisfied (NO in step S 912 ), that is, if the enlarged reproduction flag is OFF, then processing returns to step S 901  without performing enlarged display.  
         [0110]     By contrast, if the drive start conditions are satisfied, that is, if the enlarged reproduction flag is ON (YES in step S 912 ), then in step S 916  the reproduction image is JPEG expanded, enlarged and displayed, and processing returns to step S 901 . It should be noted that, in step S 916 , the enlargement magnification is determined according to the operation of the zoom lever  105  since the zoom drive flag was turned ON (that is, since reaching reference operation extent V 2  or time-out time T 1 ).  
         [0111]     Additionally, if in step S 903  it is determined that the apparatus is in multi-image reproduction, then in step S 907  a multi-image reproduction determination process is performed.  
         [0112]     Here, a description is given of the multi-image reproduction determination process of the second embodiment performed in step S 907 , with reference to  FIG. 11 .  
         [0113]      FIG. 11  is a flow chart showing details of a multi-image reproduction determination process according to the second embodiment of the present invention.  
         [0114]     First, in step S 1101 , the multi-image reproduction flag is initialized to OFF. In step S 1102 , a monitor timer that measures a period of time since the start of operation of the zoom lever  105  is started. Next, in step S 1103 , it is determined whether or not the extent of operation of the zoom lever  105  has exceeded a preset reference operation extent V 3 . If the extent of operation of the zoom lever  105  has exceeded the preset reference operation extent V 3  (YES in step S 1103 ), then the multi-image reproduction flag is set to ON (step S 1105 ) so as to perform enlarged reproduction. In step S 1106 , processing is ended after the monitor timer is stopped.  
         [0115]     By contrast, if the extent of operation of the zoom lever  105  is less than V 3  (NO in step S 1103 ), then in step S 1104  it is determined whether or not the operation of the zoom lever  105  has stopped. If the operation has not stopped, then in step S 1107  it is determined whether or not the monitor timer has exceeded a preset time-out time T 2 , and, if not, processing returns to step S 1103  and the detection of the extent of operation is repeated. By contrast, if the extent of operation of the zoom lever  105  has not exceeded the reference operation extent V 3  within the time-out time T 2  since the start of operation of the zoom lever  105  (NO in step S 1103 ), and further, if the operation of the zoom lever  105  has stopped (YES in step S 1104 ), then the multi-image reproduction determination process is ended after the monitor timer is stopped in step S 1106 . As a result, the multi-image reproduction flag set in step S 1101  remains OFF.  
         [0116]     Additionally, if the operation of the zoom lever  105  continues (NO in step S 1004 ) and the monitor timer exceeds the time-out time T 2  (YES in step S 1107 ), then in step S 1108  the multi-image reproduction flag is set to ON so as to perform enlarged reproduction. Processing is ended after the monitor timer is stopped in step S 1106 .  
         [0117]     If as a result of the multi-image reproduction determination process in step S 907  described above the drive start conditions are not satisfied (NO in step S 911 ), that is, if the multi-image reproduction flag is OFF, then processing returns to step S 901  without performing single-image display.  
         [0118]     By contrast, if the drive start conditions are satisfied, that is, if the multi-image reproduction flag is ON (YES in step S 911 ), then in step S 915 , of the plurality of images being displayed during multi-image reproduction, an image being selected is displayed at full screen size magnification and processing returns to step S 901 .  
         [0119]     Next, a description is given of a case in which the results of the determination made in step S 902  indicate that the direction of operation is in the wide-angle direction.  
         [0120]     If it is determined in step S 904  that the apparatus is in multi-image reproduction, then processing returns to step S 901 . On the other hand, if it is determined that the apparatus is not in multi-image reproduction, in other words, that the apparatus is in single-image display, then processing proceeds to step S 905 , where it is determined if the image being displayed is at full screen size magnification. If the display is not at full screen size magnification, then processing proceeds to step S 909  and the enlarged reproduction determination process described above with reference to  FIG. 10  is performed. If the display is at full screen size magnification, then processing proceeds to step S 910  and the multi-image reproduction determination process described above with reference to  FIG. 11  is performed.  
         [0121]     If as a result of the enlarged reproduction determination process in step S 909  described above the drive start conditions are not satisfied (NO in step S 913 ), that is, if the enlarged reproduction flag is OFF, processing returns to step S 901  without performing reduced display.  
         [0122]     By contrast, if the drive start conditions are satisfied, that is, if the enlarged reproduction flag is ON (YES in step S 913 ), then in step S 917  a reduced display of reproduction images is performed and processing returns to step S 901 . It should be noted that, in step S 917 , the magnification is determined according to the operation since the zoom drive flag is turned ON (that is, since reaching either the reference operation extent V 2  or the time-out time T 1 ).  
         [0123]     If as a result of the multi-image reproduction determination process in step S 910  the drive start conditions are not satisfied (NO in step S 914 ), that is, if the multi-image reproduction flag is OFF, then processing returns to step S 901  without performing multi-image reproduction.  
         [0124]     On the other hand, if the drive start conditions are satisfied, that is, if the multi-image reproduction flag is ON (YES in step S 914 ), then processing proceeds to step S 915 , multi-image reproduction is performed, and processing then returns to step S 901 .  
         [0125]     According to the second embodiment described above, by setting the reference operation extent V 1  of the zoom lever  105  at a very small value in the image sensing mode, the driving of the zoom can be started promptly in response to the operation of the zoom lever  105 . At the same time, by determining that enlarged reproduction is to be performed if in the reproduction mode the extent of operation of the zoom lever  105  has exceeded a set operation extent (V 2 , where V 2 &gt;V 1 ), or if the zoom lever  105 , though minimally operated, is nevertheless continuously operated for a predetermined period of time or more (that is, T 1 ), the possibility that the user might perform an unintentional enlarged display if the zoom lever  105  is inadvertently moved can be reduced.  
         [0126]     Further, by configuring the apparatus so that the apparatus determines that it is permissible to switch between multi-image reproduction display and single-image display if the zoom lever  105  is operated beyond a certain extent (that is, V 3 , where V 3 &gt;V 2 ), or if the zoom lever  105 , though minimally operated, is nevertheless continuously operated for a predetermined period of time or more (that is, T 2 , where T 2 &gt;T 1 ), the possibility that the user might perform an unintentional switching between multi-image reproduction and single-image display can be reduced.  
         [0127]     It should be noted that although in the second embodiment described above the image sensing mode determination logic ( FIG. 7 ), the reproduction mode enlarged reproduction determination logic ( FIG. 10 ) and the multi-image reproduction determination logic ( FIG. 11 ) are separate, alternatively a single determination logic may be used and different values for each mode may be used for the reference operation extent and monitor timer.  
         [0128]     Additionally, although in the second embodiment described above the reproduction mode determination logic ( FIG. 10 ) and the multi-image reproduction determination logic ( FIG. 11 ) are the same, with different values used for the reference operation extent and monitor timer, alternatively, the determination logic may be different.  
         [0129]     Additionally, although in the second embodiment described above the zoom drive is provided or not depending on the extent of operation of the zoom lever even in the image sensing mode, alternatively such operation may not be performed in the image sensing mode.  
         [0130]     As many apparently widely different embodiments of the present invention can be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the appended claims.