Image capturing apparatus and method for controlling the same

An image capturing apparatus includes an image capturing unit configured to capture an image of a subject to generate image data; a detachable display unit configured to display the image data generated by the image capturing unit; a wireless communication unit configured to connect with a second device including the display unit via wireless communication; a detection unit configured to detect attachment/detachment of the display unit; and a control unit configured to control the wireless communication unit in order that connection to one of the display unit and the second device is given priority depending on the attachment/detachment of the display unit detected by the detection unit.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image capturing apparatus and a method for controlling the image capturing apparatus, and in particular, it relates to a technique suitable for use in controlling an image capturing apparatus, which can be separated into an image capturing unit and a display unit, depending on whether they are connected together.

2. Description of the Related Art

A method for wirelessly transmitting and receiving images taken by a camera or playback images between the camera and a monitor separated therefrom has been proposed in the related art. For example, Japanese Patent Laid-Open No. 2007-336526 discloses a digital camera to which a display unit is detachably attached and which can wirelessly transmit captured-image data to a display unit.

Meanwhile, in recent years, an increasing number of peripheral devices, so-called accessories, of digital cameras are also equipped with wireless capability and are capable of wireless communication with the digital cameras. However, such current circumstances are not taken into consideration in Japanese Patent Laid-Open No. 2007-336526, described above.

In other words, the above disclosure takes no thought of which device is given priority as a device to be connected to the digital camera. This may require much time and effort for the user to select a device for which wireless communication is to be established or may hinder user's intended operation.

SUMMARY OF THE INVENTION

The present invention provides an image capturing apparatus including an image capturing unit configured to capture an image of a subject to generate image data; a detachable display unit configured to display the image data generated by the image capturing unit; a wireless communication unit configured to connect with a second device including the display unit via wireless communication; a detection unit configured to detect attachment/detachment of the display unit; and a control unit configured to control the wireless communication unit in order that connection to one of the display unit and the second device is given priority depending on the attachment/detachment of the display unit detected by the detection unit.

DESCRIPTION OF THE EMBODIMENTS

Embodiments of the present invention will be described in detail hereinbelow with reference to the attached drawings.

FIG. 1is a diagram showing a connecting configuration of an image capturing unit and a display unit separated from each other according to an embodiment of the present invention.

First Embodiment

FIG. 1is a diagram showing a case in which an image capturing unit101equipped with a wireless communication unit and a display unit104are detachably connected via wireless communication to configure a network. The image capturing unit101includes a wireless-communication stating member102and a power switch103. This uses IEEE802.11 ad hoc mode wireless communication, in which either of the units may serve as an access point.

FIG. 2is a diagram showing a network connection with an external device201in a case in which the image capturing unit101equipped with a wireless communication unit and the display unit104are integrated with each other.

FIG. 3is a block diagram showing an example of the hardware configuration of the image capturing unit101.

The image capturing unit101includes a system bus309and the following elements connected to the system bus309.

A CPU301controls the overall image capturing unit101by executing control programs stored in a ROM302.

The ROM302is a non-volatile memory that stores the above-mentioned programs and so on.

A RAM303is a volatile memory for use as a work area when the CPU301executes the control programs. The RAM303is also used as an area for temporarily buffering captured images before they are stored in a storage medium307.

An image generating section304performs image generating processes, such as JPEG coding and MPEG coding, on digital electrical signals that an image capturing section305stores in the RAM303to generate image data. The image generating section304performs image generating processes on images stored in the storage medium307also when editing the images to generate image data.

The image capturing section305includes an optical lens, a CMOS, an AD converter, and so on. The image capturing section305converts light entering through the optical lens to a digital electrical signal and stores it in the RAM303. The mage capturing section305reflects light incident on a finder (not shown) through the optical lens with a mirror and displays the light through a pentaprism. The finder displays image capturing parameters and other information. In this embodiment, the finder also displays information indicating whether the image capturing unit101is connected to the display unit104.

A storage-medium control section306controls the storage medium307, described below.

The storage medium307is a device for storing image data, for example, CompactFlash® and a hard disk.

A communication I/F308is an interface for communicating with an external device, for example, a wireless LAN and Bluetooth®. In this embodiment, a wireless LAN is used by way of example.

An operating section310includes a shutter button, an arrow key, an enter button, a menu button, a power button, and so on. The shutter button takes two states, half press ((SW1) and full press (SW2), depending on the pressing operation. The arrow key is used, for example, for selecting image data. The enter button is used for determining an option item. The user can give an instruction to the image capturing unit101using the operating section310.

A power-supply control section311supplies power to the image capturing unit101and is given information on the remaining buttery level and so on by the CPU301.

A display unit I/F312is an interface for communication when the image capturing unit101is integrated with the display unit104. An example of the display unit I/F312is an electrical connector.

FIG. 4is a block diagram showing an example of the hardware configuration of the display unit104.

The display unit104includes a system bus406and the following elements connected to the system bus406.

A CPU401controls the overall display unit104by executing control programs stored in a ROM402.

The ROM402is a non-volatile memory that stores the above programs.

A RAM403is a volatile memory for use as a work area when the CPU401executes the control programs.

A communication I/F405is an interface for communication with an external device, for example, a wireless LAN and Bluetooth®. In this embodiment, a wireless LAN is used by way of example.

A power-supply control section407supplies power to the display unit104and is given information on the remaining battery levels and so on by the CPU401.

An image capturing unit I/F408is an interface for communication when the display unit104and the image capturing unit101are integrated. An example of the image capturing unit I/F408is an electrical connector.

A display section404displays an image captured by the image capturing section305or an image played back from the storage medium307when connected to the image capturing unit101via the communication I/F405or the image capturing unit I/F408. The display section404also displays a GUI corresponding to an instruction using the operating section310.

Referring now toFIG. 5, a starting operation at power ON, which is a feature of this embodiment, will be described. The flowchart inFIG. 5is started when the power switch103, which is part of the operating section310, is operated at the image capturing unit101, so that power is supplied to the components of the image capturing unit101from the power-supply control section311.

At S502, when the image capturing unit101is supplied with power, the CPU301determines whether the display unit104is connected thereto via the display unit I/F312. As a result of the determination, if the image capturing unit101is not separated from the display unit104but is connected thereto via the display unit I/F312, the process goes to S507to enable a menu to be displayed. If the image capturing unit101is separated from the display unit104, the process goes to S503.

At S503, the CPU301searches for the display unit104using a predetermined wireless parameter via the communication I/F308. The search is performed using a service set identifier (SSID), which is one of predetermined wireless parameters. For ad hoc communication (wireless LAN ad hoc mode communication), a predetermined channel is used to allow an efficient search by searching for the SSID using the specified channel. The SSID is generally included in beacon signals transmitted at regular intervals from a so-called access point. Devices connected to the access point find the SSID by receiving the beacon signals. However, in this embodiment, it is determined in advance that the image capturing unit101and the display unit104are to use a common SSID, so that a search signal is transmitted without passing through the process of narrowing the communication target using beacon signals or the like.

At S504, the CPU301determines whether the display unit104has been found via the communication I/F308. Specifically, when receiving a response to the transmitted search signal from the display unit104, the CPU301determines that the display unit104has been found. If the display unit104has been found, the process goes to S505. If the display unit104has not been found, the process goes to S506.

At S505, the CPU301performs a process for connecting with the display unit104via the communication I/F308using a predetermined wireless parameter. If the connection has been established, the process goes to S507. If the connection has not been established, the process goes to S506.

If the image capturing unit101and the display unit104are separated and are not connected together in a predetermined time, then at S506, the CPU301displays the result on the finder of the image capturing unit101. Examples of the indication include a connection mark and any other indications that user can understand. Thereafter, the process of this flowchart ends.

Since, at S507, the display unit104has been connected, the display section404of the display unit104is enabled to display a menu. Thereafter, the process of the flowchart ends.

The foregoing flowchart is executed in parallel with a process of starting an image capturing mode or a playback mode that is started when power is turned on.

As described above, the start-up operation at power ON is switched depending on whether the image capturing unit101and the display unit104are integrated or separated when the image capturing unit101is supplied with power. This allows the user to operate the image capturing apparatus without consciousness while using the display section404of the display unit104.

Second Embodiment

Referring toFIG. 6, a wireless search and a method for connection according to a second embodiment of the present invention will be described.

The feature described below is to change the operation depending on whether the image capturing unit101and the display unit104are integrated or separated when the wireless-communication stating member102is operated.

The flowchart inFIG. 6is started when the wireless-communication starting member102, which is part of the operating section310, is operated at the image capturing unit101.

First, at S602, the CPU301determines whether the image capturing unit101and the display unit104are connected via the display unit I/F312. As a result of the determination, if the image capturing unit101is not separated from the display unit104but is connected to the display unit104via the display unit I/F312, the process goes to S609. If the image capturing unit101and the display unit104are separated, the process goes to S603.

At S603, since the image capturing unit101and the display unit104are separated, the CPU301determines whether communication between the image capturing unit101and the display unit104has been established via the communication I/F308. If communication has already been established, nothing is done, the process ends. If communication has not been established, the process goes to S604.

At S605, the CPU301determines whether the display unit104has been found via the communication I/F308. As a result, if the display unit104has been found, the process goes to S606. If the display unit104has not been found, the process goes to S607.

At S606, since the display unit104was found at S605, the CPU301connects to the display unit104using a predetermined wireless parameter via the communication I/F308. If the connection has been completed, the process goes to S608. If the connection has not been completed, the process goes to S607.

If the image capturing unit101and the display unit104are separated and are not connected together in a predetermined time, then at S607, the CPU301displays the result on the finder of the image capturing unit101. Examples of the indication include a connection mark and any other indications that user can understand. Thereafter, the process of this flowchart ends.

Since, at S608, the display unit104has been connected, the display section404of the display unit104is enabled to display a menu. Thereafter, the process of the flowchart ends.

On the other hand, at S609, the CPU301determines which of the communication I/F308of the image capturing unit101and the communication I/F405of the display unit104is to be used for communication. For the determination, the CPU301may compare a remaining battery level obtained from the power-supply control section311of the image capturing unit101with a remaining battery level obtained from the power-supply control section407of the display unit104and select one at a higher level. Alternatively, the user may make a selection. A communication I/F to be used is determined in accordance with the above determination, and the process goes to S610.

At S610, a peripheral device is searched for using the communication I/F determined at S609, and the process goes to S611.

At S611, information on the peripheral device (external device201) found at S610is displayed on the display section404of the display unit104. Thereafter, the process of the flowchart ends.

From then on, communication with the external device201is enabled by establishing communication therewith using the screen.

As described above, when the wireless-communication starting member102is operated in a state in which the image capturing unit101is not connected to the display unit104, connection with the display unit104is given priority over peripheral devices. This allows user-intended wireless search and connection, thus enhancing the convenience.

Third Embodiment

Referring toFIGS. 7A and 7B, control at power-off in a state in which the image capturing unit101and the display unit104are separated, according to a third embodiment of the present invention, will be described hereinbelow.

FIG. 7Ais a flowchart showing a shutdown process by turning off the power at the image capturing unit101.

This flowchart is started when an instruction to turn off the power by an operation on the power switch103, which is part of the operating section310, at the image capturing unit101is received.

First, at S702, the CPU301determines whether the image capturing unit101and the display unit104are connected via the display unit I/F312. As a result of the determination, if the image capturing unit101is not separated from the display unit104but is connected to the display unit104via the display unit I/F312, the process goes to S705. If the image capturing unit101and the display unit104are separated, the process goes to S703.

At S703, the CPU301determines whether communication between the image capturing unit101and the display unit104has been established via the communication I/F308. As a result of the determination, if communication between the image capturing unit101and the display unit104via the communication I/F308has not been established, the process goes to S705. If communication between the image capturing unit101and the display unit104via the communication I/F308has been established, the process goes to S704.

At S704, the CPU301sends a shutdown notification to the display unit104via the communication I/F308of the image capturing unit101.

At S705, the CPU301performs a process of shutting down the image capturing unit101to stop power supply to the components of the image capturing unit101.

FIG. 7Bis a flowchart showing a shutdown process at the display unit104, corresponding to the process inFIG. 7A.

This flowchart is started when the CPU401of the display unit104receives an event from the image capturing unit101via the communication I/F405.

First, at S712, the CPU401determines the details of the received event. As a result of the determination, if it is a shutdown notification, the process goes to S714. If it is not a shutdown notification but another process notification, the process goes to S713to perform a process corresponding to the notification.

At S713, the CPU401performs the process corresponding to the received event.

At S714, the CPU401performs an intermittent wireless communication in response to the reception of the shutdown notification from the image capturing unit101. Specifically, the CPU401operates so as to alternately repeat a stand-by mode in which the display unit104can respond to a connection request from the image capturing unit101and a sleep mode in which the display unit104cannot respond to a connection request from the image capturing unit101. This operation is referred to as an intermittent wireless communication operation in a sense that the display unit104intermittently enters a stand-by mode in which the display unit104can respond to a connection request from the image capturing unit101(a radio-signal receivable mode). The period of the stand-by mode and the period of the sleep mode may be set to either predetermined fixed values or any values set by the user. The period during which an intermittent operation is continued may be limited. In other words, if no connection request is issued from the image capturing unit101even after a lapse of a set period of time after receiving a shutdown notification and shifting to the intermittent operation, the intermittent wireless communication operation may be stopped, and the power to the display unit104may be turned off.

In the above operation, when the power to the image capturing unit101is turned off, a shutdown notification is issued from the image capturing unit101to the display unit104, and the display unit104performs the intermittent wireless communication operation. This allows quick connection even after the user turns on the power to the image capturing unit again. This allows the user to connect the image capturing unit101to the display unit104unintentionally, thus enhancing the convenience.

Fourth Embodiment

Referring toFIG. 8, an operation during communication with the external device201according to a fourth embodiment of the present invention will be described.

FIG. 8is a flowchart illustrating an operation when the display unit104is separated from the image capturing unit101during communication with the external device201.

At S801, the CPU301determines whether the image capturing unit101is connected to the display unit104via the display unit I/F312during communication with the external device201. As a result of the determination, if the image capturing unit101and the display unit104are separated, the process goes to S802.

At S802, the CPU301cuts the connection to the external device201and searches for the display unit104.

At S803, the CPU301determines whether connection between the image capturing unit101and the display unit104via the communication I/F308has been completed. As a result of the determination, if the connection has been completed, the process goes to S804. If the connection has not been established, the process goes to S805.

At S804, since the connection between the image capturing unit101and the display unit104has been completed in a state in which they are separated, the display section404of the display unit104is enabled to display a menu. Thereafter, the process of this flowchart ends.

At S805, since the connection between the image capturing unit101and the display unit104has not been completed in a state in which they are separated, the CPU301determines whether a predetermined number of connecting operations have been performed. Specifically, the CPU301determines whether the number of searching operations at step S802after it is determined at S801that the image capturing unit101and the display unit104are separated has reached the predetermined number. If the predetermined number of connecting operations have not been performed, the process returns to S802, and the process from S802to S805is repeated. If the predetermined number of connecting operations have been performed, the CPU301determines that connection to the display unit104is impossible, and the process goes to S806.

At S806, the CPU301displays an indication that the connection has failed on a display device, such as a finder of the image capturing unit101. Not the display device but a light-emitting device, such as an LED, may be used for notifying the user. Thereafter, the process of the flowchart ends.

The foregoing process can minimize, when the display unit104is separated from the image capturing unit101while the image capturing unit101is connected to the external device201, a state in which the user cannot use the display unit104by giving priority to connection to the display unit104. Although not shown in the embodiment, if the image capturing unit101and the external device201are halfway through transfer of data, the above-described operation may be performed after completion of the transfer.

Although the above embodiments show a case in which the display unit104is separated from the image capturing unit101, the present invention can be applied to a case in which the image capturing unit101and an external device including a display unit can be integrated. An example of the external device including a display unit is a smart phone.

The fourth embodiment has been described using an example in which, when the display unit104is separated while the image capturing unit101is communicating with the external device201, the connection with the external device201is automatically terminated. However, there may be a case in which the user gives a higher priority to connection with the external device201. Thus, even if the display unit104is separated while the image capturing unit101is communicating with the external device201, the connection with the external device201may be maintained, and when the user operates the wireless-communication starting member102in this state, the process may go to S802. In other words, the user may be enabled to indicate user's intention to give a higher priority to the display unit104over the external device201using the operation on the wireless-communication starting member102. If the connection cannot be established although the display unit104is searched for using an operation on the wireless-communication starting member102as a trigger, the image capturing unit101may be connected to the external device201again. This further enhances the usability.

While embodiments of the present invention have been described, the present invention is not limited to the embodiments, and various modifications and changes can be made in the scope of the spirit of the invention.

Other Embodiments

The present invention can be implemented by executing the following process. Specifically, software (computer programs) for implementing the functions of the above embodiments is provided to a system or device via a network or various kinds of computer-readable storage media. Then, a computer (or CPU, MPU, etc.) of the system or device reads the programs.

This application claims the benefit of Japanese Patent Application No. 2014-004307, filed Jan. 14, 2014, which is hereby incorporated by reference herein in its entirety.