Abstract:
An imaging apparatus includes an imaging unit, a record and reproduction unit for recording and reproducing image data on and from a record medium, a display unit, a communication unit arranged to transmit captured image data and reproduced image data to an external device, and a mode switch unit for switching over a plurality of operation modes in accordance with a connection status of the communication unit. The plurality of operation modes includes a first mode in which the communication unit is operated and operations of the imaging unit and the display unit are stopped; a second mode in which the communication unit and the display unit are operated to display an image reproduced from the record medium on the display unit, and an operation of the imaging unit is stopped; and a third mode in which the imaging unit, the display unit, and the communication unit are operated to display an image captured by the imaging unit on the display unit.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to an imaging apparatus, and more specifically to an apparatus capable of switching an operation mode in accordance with a status of connection with a PC (personal computer), a printer, etc.  
         [0003]     2. Related Background Art  
         [0004]     Conventionally, a system for connecting a digital camera with an information processing apparatus such as a personal computer (PC), etc. via a cable, etc., so that the information such as image data, etc. recorded on a recording apparatus in the digital camera or on a record medium attached detachably to the digital camera can be transferred to the PC has been developed and introduced commercially (for example, Japanese Patent Application Laid-Open No. 2003-125271).  
         [0005]     In recent years, a system in which a digital camera can be directly connected to a printer via a cable to attain printing without a PC has become commercially practical. In this case, there are different devices such as a PC and a printer to be connected to a digital camera. If an interface and a protocol which can be commonly used by these different devices in communication with a camera are available, the camera can communicate with these different devices without any problems.  
         [0006]     Lately, a standard called “Pict Bridge” has been proposed as a system for communication between a camera and a printer which are directly connected.  
         [0007]     In the version 1.0 of this standard, a camera is connected to a printer via a general-purpose bus called “USB” (universal serial bus), and the printer functions as a host of the USB. Data exchange is performed using a PTP (picture transfer protocol) as a communication protocol. The protocol is also a general-purpose protocol prescribed by the still imaging device class of the USB as for a data exchange protocol for a PC and a camera.  
         [0008]     Thus, a camera can communicate data through a common protocol independent of the type of communicatee. Using the Pict Bridge, data exchange called “service discovery” is performed in order to recognize whether the communicates is a printer adaptable to the Pict Bridge. Through the data exchange, the printer and the camera recognize each other as to whether or not they are adaptable to the Pict Bridge, and a service is offered by exchanging script data described in a data format predetermined by the Pict Bridge.  
         [0009]     On the other hand, conventionally, when a camera is connected to a PC, the camera has normally been operated by the PC, and there is few opportunity to operate the camera itself. Therefore, except a small number of digital cameras for professional use, a power saving effect has been expected by turning off the operation of the camera and the display device thereof in the PC connection mode when the camera is connected to the PC.  
         [0010]     Digital cameras such as those for professional use can use a relatively large number of resources such as ROM, RAM, etc. in the cameras, and a battery of a large capacity can be used. Therefore, when a PC is connected, no PC connection mode may be required in the operation of a camera. However, with a common compact digital camera, there are restrictions on the resources and power supply, and thus the resources of the ROM and RAM are saved by exclusively controlling the internal status and no power is supplied to an inactive block to save the power when the PC is connected.  
         [0011]     Conventionally, different communication protocols have been used among manufacturers in connection to the printer and a digital camera and a printer therefore cannot be connected unless they are manufactured by the same manufacturer. However, there have been digital cameras operable by connecting them to the printer directly via USB by communicating them with a PC using the USB. In this case, since different protocols are used between the case in which a camera is connected to a PC and the case in which a camera is connected to a printer, it is necessary to implement a plurality of protocols in a camera. As described above, when there are a plurality of communication modes in a digital camera, it is necessary to switch over them.  
         [0012]     In the conventional system, as described above, different communication protocols are used for connection to a PC and a printer, or unique protocol is used for each type of device. Therefore, it has been necessary to switch over a communication mode when a digital camera recognizes the difference in protocol or when a communication mode switch command is received.  
         [0013]     There is also the technology of making the operation of a camera valid under the control of a PC when the camera is connected to the PC, displaying an image, etc. on the display device implemented in the camera, and allowing a user to operate the member of a camera to transfer the image to the PC has already been proposed (for example, Japanese Patent Application Laid-Open No. 2002-133406 (corresponding to the U.S. application Laid-open No. 2002-063781)).  
         [0014]     Thus, the method of merely transferring image data in a camera to a PC which has conventionally been an only external apparatus for storage and browsing the image data has been enhanced to an application of a model of operating a PC and a camera in cooperation.  
         [0015]     However, as described above, in recent years, even if the digital camera is connected to the printer, the standard of data communications using a digital camera connected to an external equipment has been standardized in many cases so that the protocol used when a PC is connected can be used. In this case, a communicatee can be recognized only after the discovery is made for recognition of the communicatee defined with the standardized regulations.  
         [0016]     Although there is little problem if all devices to which a digital camera is connected are standardized by the Pict Bridge, an application having no relation with the Pict Bridge is connected in the current status of connecting to a normal PC. In this case, unlike the conventional cases, there is the problem that a camera cannot find the timing at which it enters a communication mode when it is connected to a PC. Otherwise, it is necessary for a user before connection with an external apparatus to select the setting of a digital camera to decide whether the digital camera is connected to a printer or a PC, and it is therefore necessary to connect the camera to the external device to change the process to be performed.  
         [0017]     Furthermore, although a digital camera is connected to a device such as a PC, etc., there can be a case in which the communication mode of a camera is switched by an application running in the device. In this case, depending on the communication mode switch timing of a camera, it has become necessary for a camera to use a system which can utilize effectively the minimal resources and save electric power.  
         [0018]     Therefore, when a digital camera and an external device are connected to each other for communication, the control in the camera is required in greater detail.  
       SUMMARY OF THE INVENTION  
       [0019]     The present invention aims at solving the above-mentioned problem.  
         [0020]     Another objective of the present invention is to simplify the operation mode switching operation by a user and reduce the power consumption during communications.  
         [0021]     To solve the above-mentioned problems and attain the objectives, according to an aspect of the present invention, an imaging apparatus includes: imaging means; record and reproduction means for recording and reproducing image data captured by the imaging means on and from a record medium; display means; communication means arranged to transmit image data obtained by the imaging means and image data reproduced from the record medium to an external device, the communication means being connectable to the external device through a transmission line; and mode switch means for switching over a plurality of operation modes in accordance with a connection status of the communication means, wherein the plurality of operation modes includes: a first mode in which the communication means is operated and operations of the imaging means and the display means are stopped; a second mode in which the communication means and the display means are operated to display an image of image data reproduced from the record medium on the display means, and an operation of the imaging means is stopped; and a third mode in which the imaging means, the display means, and the communication means are operated to display an image of image data obtained by the imaging means on the display means.  
         [0022]     Other objectives and features of the present invention are clarified by the detailed explanation of the aspect of the invention by referring to the following drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0023]      FIG. 1  is a block diagram of the configuration of the digital camera system according to an embodiment of the present invention;  
         [0024]      FIGS. 2A, 2B ,  2 C and  2 D are explanatory views of the operation status according to an embodiment of the present invention;  
         [0025]      FIG. 3  which is comprised of  FIGS. 3A and 3B  are flowcharts of the operation performed when a USB cable is connected to an external device, and a camera enters an external connection mode;  
         [0026]      FIG. 4  is a flowchart of the process performed when shifting to a default communication mode;  
         [0027]      FIG. 5  is a flowchart of the process performed when shifting to a print mode;  
         [0028]      FIG. 6  is a flowchart of the process performed when shifting to a direct transfer mode;  
         [0029]      FIG. 7  is a flowchart of the process performed when shifting to a remote control mode;  
         [0030]      FIG. 8  is a flowchart of the operation in an external connection mode according to another embodiment of the present invention;  
         [0031]      FIG. 9  shows an example of a menu displayed on a display member in a direct-transfer mode; and  
         [0032]      FIG. 10  shows the state transition of a digital camera according to an embodiment of the present invention.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0033]     The preferred embodiments of the present invention are explained below in detail by referring to the attached drawings.  
         [0034]      FIG. 1  is a block diagram of the configuration of a digital camera system according to an embodiment of the present invention. In the present embodiment, the system can be roughly divided into units, that is, an information input apparatus  100  (hereinafter referred to as a digital camera) such as a digital camera, etc. and an information processing apparatus  101 . The information processing apparatus  101  is normally a PC, which includes an arithmetic processing unit (CPU) not shown, a primary storage apparatus (RAM), a secondary storage apparatus (hard disk), an operation apparatus (keyboard, mouse), a display device (display), etc.  
         [0035]     The digital camera  100  can be configured by an optical unit  105  including a lens, a CCD, a drive circuit, etc., a signal processing apparatus  104  for processing image data, etc., an operation apparatus  103  such as a CPU, a primary storage apparatus  106  such as a DRAM, a secondary storage apparatus  107  such as a built-in flash ROM, an operating member  108 , a displaying device  109  such as an LCD, read-only memory  110  such as ROM, for use in storing a program, a detachable record medium  111  such as a memory card, and a communication control apparatus  102  for managing a connection to the PC  101 . Depending on the type of digital camera, the configuration can be designed to record and reproduce image data on and from only one of the memory card M and the built-in flash ROM  107 .  
         [0036]      FIGS. 2A  to  2 D show examples of the connection status according to an embodiment of the present invention.  
         [0037]      FIGS. 2A, 2B , and  2 C show the operation statuses indicated when the digital camera  100  is connected to the PC  101 . In these examples, each of the components are connected via a cable. Currently, the most common connection means for such a connection is indicated by the USB.  
         [0038]      FIG. 2A  shows an example of a functioning state of what is called a browser software for transferring, displaying, browsing, and storing the information such as image data, recorded in a digital camera on a PC. In this case, the camera is required only to be operated by the PC as a slave to the PC.  
         [0039]      FIG. 2B  shows the functioning status of an application for transferring data in the camera to the PC to display, browse, and store the data in the camera as shown in  FIG. 2A . By the operation of a camera, an image is selected and a transfer thereof is started. In the above-mentioned application, the menu as shown in  FIG. 9  is displayed on the display device on the digital camera side, and by operating the operating member of the digital camera, the operation of an application is controlled. The digital camera itself functions as a remote control device. In this case, the digital camera functions as the central component, and therefore can use a reproduction function and an operation member, etc.  
         [0040]      FIG. 2C  shows an example of controlling a capturing operation by operating a camera from the application of the PC. In this case, a shooting operation is performed with a camera by the operation of the application on the PC or by the operation of the operating member of the camera. The shot image is transferred to the PC and stored, and the photographing parameter of the camera and the zoom by a zoom lens can be controlled. At this time, the digital camera has to be configured such that a shooting function is operable in the communication state.  
         [0041]      FIG. 2D  shows an example of the case in which digital camera and a printer are connected to each other.  
         [0042]     In this case, a user operates the operating member of a camera to specify an image or issue an instruction, and then performs printing. At this time, it is necessary that the digital camera is in the communication status, and the printing function can be used.  
         [0043]     As described above, when an application of operating a digital camera in cooperation with a PC and an external device such as a printer is considered, it is necessary that the digital camera can operate functions necessary for not only a communication control apparatus but also each application.  
         [0044]     Described below in detail is the switch of each communication mode according to the present embodiment.  FIG. 10  shows the state transition in a digital camera according to the first embodiment of the present invention.  
         [0045]     When the camera is powered up from the power-off state by the user operation, the digital camera is activated and enters the reproduction status.  
         [0046]     In this status, when the USB cable is connected to an external device, the camera enters a default communication mode. This mode is the most frequently used PC communication mode in which the data in the camera can be transferred or stored by the operation of the PC.  
         [0047]     However, in this status, the operation on the camera cannot be performed, and the display member such as the LCD also cannot be activated. When a command to transfer to each mode from this status is issued from an external device, the digital camera enters each corresponding mode.  
         [0048]     For example, when a printer is connected, a command to enter a print mode is received, and the camera enteres the print mode. In this mode, a user can the operating member of the camera to instruct an image to be printed and the start of printing. Therefore, the image data reproduction function for the memory card and the operating member can be available.  
         [0049]     If a connection partner is a PC in the default communication mode and a command to enter a direct transfer mode is received from the PC, the camera enters the direct transfer mode. In this mode, as in the print mode, the user operates the operating member of the camera to select an image to be transferred to the PC, and start a transfer. To attain this, the reproduction function of image data stored in the memory card and an operating member can be available in the camera.  
         [0050]     If a connection partner is a PC in the default communication mode and a command to enter a remote control mode is received from the PC, the camera enters the remote control mode. In this mode, the camera can perform a shooting operation at an instruction from an externally-connected PC. Therefore, the function relating to the shooting operation of the camera becomes valid.  
         [0051]     In each communication mode, when a USB cable is disconnected, control exits the communication mode, and is returned to the normal reproduction mode. In each communication mode, when a power supply button is turned off, control exists the communication mode, and enters the power-off status.  
         [0052]      FIGS. 3A and 3B  show the operation flow of the digital camera when a digital camera is connected to an external device through a USB cable, and the camera enters an external connection mode.  
         [0053]     When an USB connection is established and the external connection mode is entered, control first enters the default communication mode (step S 301 ). In the default communication mode, a command can be received from an external device. Therefore, a command from an external device is awaited.  
         [0054]     When a command is received (step S 302 ), it is checked whether or not the command is a trigger to enter a print mode (step S 303 ).  
         [0055]     If it is a print mode start command, then control enters the print mode (step S 304 ). Then, the next command is awaited in the print mode (step S 312 ). A command to be received is a command executable in the default communication mode and a command executable only in the print mode.  
         [0056]     When a command is received, it is determined whether or not the command is a command to terminate a currently set mode. In this case, it is determined whether or not it is a command to terminate the print mode (step S 313 ). If it is a terminate command, then control enters the default communication mode. If it is not a terminate command, it is determined whether or not it is a command valid in the print mode as described above (step S 314 ).  
         [0057]     When it is a valid command, the command is executed (step S 315 ), control is then returned to step S 312  to await the reception of a command. If the command is not valid, error processing is performed to issue an error notification to an external device which is a communicatee (step S 316 ), and control is then returned to step S 312 .  
         [0058]     When the command received in the default communication mode is a direct transfer mode start command (step S 305 ), control is passed to a direct transfer mode (step S 306 ). Then, the next command is awaited in the direct transfer mode (step S 312 ). An acceptable command at this time is a command executable in the default communication mode, and a command executable only in the direct transfer mode.  
         [0059]     When a command is received, it is determined whether or not the command is a command to terminate a currently set mode. In this case, it is determined whether or not it is a command to terminate the direct transfer mode (step S 313 ). If it is a terminate command, then control enters the default communication mode. If it is not a terminate command, it is determined whether or not it is a command valid in the direct transfer mode (step S 314 ).  
         [0060]     When it is a valid command, the command is executed (step S 315 ), control is then returned to step S 312  to wait the reception of a command. If the command is not valid, error processing is performed to issue an error notification to an external device which is a communicatee (step S 316 ), and control is then returned to step S 312 .  
         [0061]     When the command received in the default communication mode is a remote control mode start command (step S 307 ), control is passed to a remote control mode (step S 308 ). Then, the next command is awaited in the remote control mode (step S 312 ). An acceptable command at this time is a command executable in the default communication mode, and a command executable only in the remote control mode.  
         [0062]     When a command is received, it is determined whether or not the command is a command to terminate a currently set mode. In this case, it is determined whether or not it is a command to terminate the remote control mode (step S 313 ). If it is a terminate command, then control enters the default communication mode. If it is not a terminate command, it is determined, as described above, whether or not it is a command valid in the remote control mode (step S 314 ).  
         [0063]     When it is a valid command, the command is executed (step S 315 ), control is then returned to step S 312  to await the reception of a command. If the command is not valid, error processing is performed to issue an error notification to an external device which is a communicatee (step S 316 ), and control is then returned to step S 312 .  
         [0064]     If the command received in S 302  is not any one of the print mode start command, the direct transfer mode start command, and the remote control mode start command, then it is determined in the default communication mode whether or not it is another valid command (step S 309 ). If it is a valid command, the command is processed (step S 310 ). If it is not a valid command, error processing is performed, and control is then returned to step S 302  (step S 311 ).  
         [0065]     Described below is the process performed to enter each communication mode.  FIG. 4  is a flowchart of the process performed to enter the default communication mode.  
         [0066]     In this mode, data in a camera is managed by the operation from the PC. Therefore, a block relating to a shooting function and a block relating to a reproduction function are not required to be operated in the digital camera.  
         [0067]     Therefore, first, the operations of the signal processing apparatus  104  to be used in a reproduction or shooting operation are stopped (step S 401 ). Then, the operation of the optical unit  105  to be used during the shooting are also stopped (step S 402 ). Finally, the display member  109  such as an LCD for use in image reproduction and menu display is stopped.  
         [0068]      FIG. 5  is a flowchart of the process performed to enter the print mode.  
         [0069]     In this mode, image data is transmitted to a connected printer to perform a printing operation. Therefore, the operations are the same as those in the normal reproduction mode. Since an instruction to select or print an image is issued by the operation of a camera, it is necessary to operate all blocks other than the function blocks relating to the shooting function.  
         [0070]     Therefore, the operation of the signal processing apparatus  104  to be used in a reproduction operation is first started (step S 501 ). Then, the operation of the optical unit  105  to be used in shooting is stopped (step S 502 ). Next, the display member  109  such as an LCD for use in reproducing an image or displaying a menu is activated (step S 503 ). Finally, a process module for printing is activated (step S 504 ).  
         [0071]      FIG. 6  is a flowchart of the process performed when control is passed to the direct transfer mode. In this mode, image data is transmitted to the connected PC to perform display, storage, etc. Therefore, the operations to be performed are similar to those in the normal regeneration mode. Since an instruction to select or transmit an image is issued by the operation of a camera, it is necessary to operate all blocks other than the blocks relating to the shooting function.  
         [0072]     Therefore, the operation of the signal processing apparatus  104  to be used in a reproduction operation is first started (step S 601 ). Then, the operation of the optical unit  105  to be used in shooting is stopped (step S 602 ). Next, the display member  109  such as an LCD for use in reproducing an image or displaying a menu is activated (step S 603 ). Finally, a process module for direct transfer is activated (step S 604 ).  
         [0073]      FIG. 7  is a flowchart of the process performed to enter the remote control mode. In this mode, the shooting function of a camera is controlled by the operation of the PC, and a captured image can be transferred. Therefore, it is necessary to operate the function blocks relating to the shooting function.  
         [0074]     The operation of the signal processing apparatus  104  to be used in a shooting operation is first started (step S 701 ). Then, the operation of the optical unit  105  to be used in shooting is started (step S 702 ). Finally, the display member  109  such as an LCD for use in displaying a captured image or displaying a menu is started.  
         [0075]     Thus, according to the present embodiment, when a connection to an external device is made, the operations of a signal processing apparatus, an optical unit, and a display member are stopped regardless of the types of a connected device or an application, the default mode in which only a communication operation can be performed is entered, and then an operation mode depending on the command received from a connection partner is entered. Therefore, the resources in a camera required to each communication mode can be selectively used, thereby controlling the amount of power consumption with precision.  
         [0076]     Furthermore, each communication mode can be flexibly entered in accordance with the conditions of the application of a connection partner, and a user can omit the trouble of the processes required in switching a mode.  
         [0077]     When each communication mode terminates, control is returned to the default communication mode requiring the lowest power consumption. Therefore, an advantageous system in power consumption can be realized when an image is transferred by the operation from the PC which may be most frequently used in a normal state or a standby state.  
         [0078]     Described below is the second embodiment of the present invention.  
         [0079]     In the second embodiment, the basic configuration, the existing statuses and the like are similar to those according to the first embodiment. However, a transfer system in each communication mode is different. Therefore, the operations in an external connection mode of a digital camera according to the second embodiment are explained by referring to the flowchart shown in  FIG. 8 .  
         [0080]     When a USB connection is established, and the external connection mode is entered, the default communication mode is first entered (step S 801 ). Then, a command from an external device is acceptable and awaited. When a command is received (step S 802 ), it is checked whether or not the received command is a print mode command (step S 803 ).  
         [0081]     If it is a print mode command, then it is determined whether or not the current status is a print mode (step S 804 ). If it is not a print mode, then the print mode is entered (step S 805 ), and the command is executed (step S 814 ). If the print mode has already been entered, then the command is executed as is (step S 814 ). Then, control is passed to step S 802 .  
         [0082]     When the received command is a direct transfer mode command, then it is determined whether or not the current status is a direct transfer mode (step S 807 ). If it is not a direct transfer mode, the direct transfer mode is entered (step S 808 ), and the command is executed (step S 814 ) If the print mode has already been entered, then the command is executed as is (step S 814 ). Then, control is returned to step S 802 .  
         [0083]     If the received command is a remote control mode command, then it is determined whether or not the current status is a remote control mode (step S 810 ). If it is not a remote control mode, the remote control mode is entered (step S 811 ), and the command is executed (step S 814 ). If the remote control mode has already been entered, the command is executed as is (step S 814 ). Then, control is returned to step  802 .  
         [0084]     If the received command is another valid command for the default transfer mode, then the command is executed (step S 814 ). Otherwise, an error notification is issued as error processing to an external device which is a communicates (step S 813 ). Then, control is returned to step S 802 .  
         [0085]     As described above, according to the present invention embodiment, no command is prepared to enter or terminate each communication mode, but when a command valid only in each mode is received, the camera automatically enters the mode. Therefore, the connection partner is free of the consideration of the mode switch when a desired application is to be performed.  
         [0086]     When a user selects an image and transfers it to a PC while reproducing and displaying an image with a camera set in a reproduction mode, the operations of the module relating to the shooting function of the camera are stopped. On the other hand, when the shooting operation of the camera is remotely controlled by the PC, a module necessary for reproduction is stopped, thereby reducing the power consumption.  
         [0087]     It is obvious that the objectives of the present invention can also be attained by providing a storage medium recording a program code of software for realizing the function of the above-mentioned embodiments for a system or an apparatus, and the computer of (or the CPU or the MPU) the system or the apparatus reading and executing the program code stored in the storage medium.  
         [0088]     In this case, the program code read from the storage medium realizes the function of the above-mentioned embodiment, and the program code itself and the storage medium storing the program code configure the present invention.  
         [0089]     A storage medium for providing a program code can be, for example, a flexible disk, a hard disk, an optical disk, a magneto-optical disk, CD-ROM, CD-R, a magnetic tape, a non-volatile memory card, ROM, etc.  
         [0090]     Furthermore, by executing the program code read by the computer, not only the function of the embodiments can be realized, but also all or a part of the actual processes are performed by an OS (basic system or the operating system), etc. operating in the computer at an instruction of the program code, and the function according to the above-mentioned embodiments can be realized by the process.  
         [0091]     Furthermore, after a program code read from the storage medium is written to the memory of the feature expansion unit connected to a feature expansion board inserted into the computer and a feature expansion unit connected to the computer, the CPU, etc. of the feature expansion board and the feature expansion unit can perform all or a part of the actual processed at an instruction of the program code, and the function according to the above-mentioned embodiments can be realized by the process.  
         [0092]     Many different embodiments of the present invention may be constructed without departing from the spirit and scope of the present invention. It should be understood that the present invention is not limited to the specific embodiments described in the specification, except as defined in the appended claims.  
         [0093]     This application claims priority from Japanese Patent Application No. 2004-031112 filed Feb. 6, 2004, which is hereby incorporated by reference herein.