JP2003319225A - Digital camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital camera that improves the quality of radio data communication and reduces power consumption. <P>SOLUTION: This digital camera is provided with: an imaging means for preparing image data representing an object; a housing 2 for accommodating the imaging means; an antenna 90 supported by the housing 2 and taking a first posture (Figure 1 (a)) in which its tip is farther from the hosing 2 and a second posture (Figure 1 (b)) in which the tip is closer to the housing 2; a radio communication part for performing radio data communication with another device by using the antenna 90; and a detecting part for detecting the posture of the antenna 90. When the detecting part detects the first posture of the antenna 90, the power supply to the radio communication part is increased, and when the detecting part detects the second posture of the antenna 90, the power supply to the radio communication part is reduced. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital camera.

[0002]

2. Description of the Related Art For example, Bluetooth for realizing wireless data communication between different devices such as a digital camera, a printer, a personal computer and a personal digital assistant.
The following wireless data communication standards are known. Since wireless data communication reduces the time and effort required for cable connection, it is expected to spread further in the future.

In a conventional digital camera that performs wireless data communication with other devices according to such a wireless data communication standard, since the antenna for performing wireless data communication does not protrude from the housing, the distance between the antenna and the human body and the antenna Generally, the distance from the housing is short.

[0004]

When the distance between the antenna and the human body and the distance between the antenna and the housing are short, the directivity of the antenna is deteriorated due to the electromagnetic effect of the human body and the metal housing, which causes wireless data communication. Is known to become unstable.

However, since the conventional digital camera generally has no antenna protruding from the housing, the distance between the antenna and the human body and the distance between the antenna and the housing are short, which makes it difficult to stabilize wireless data communication. If the wireless data communication is not stable, for example, a packet error is likely to occur, the number of packet retransmissions increases, and communication efficiency decreases. In particular, when the housing is made of metal, the electromagnetic effect on the antenna is further increased and the communication becomes more unstable.

In the case of a digital camera, since wireless data communication is generally performed after image data is created, the wireless communication unit provided in the digital camera is always in a communicable state while the image data is created. No need. Therefore, it is required to reduce the power supplied to the wireless communication unit while the wireless data communication is not performed.

The present invention was created in view of the above problems, and an object thereof is to provide a digital camera which improves the quality of wireless data communication and reduces power consumption.

[0008]

According to a first aspect of the present invention, there is provided a digital camera including: an image pickup means for creating image data representing a subject; a housing for accommodating the image pickup means;
An antenna that can take a first attitude in which the tip is far from the housing and a second attitude in which the tip is near the housing, a wireless communication unit that uses the antenna to perform wireless data communication with other devices, and detects the attitude of the antenna And the power supplied to the wireless communication unit when the first attitude of the antenna is detected by the detection unit, and the power supplied to the wireless communication unit when the second attitude of the antenna is detected by the detection unit. And a control unit for reducing the number. According to this digital camera, by placing the antenna in the first posture, the tip of the antenna becomes far from the housing, and the antenna and the housing can be separated from each other. As a result, the distance between the antenna and the human body can be increased, and the influence of the human body and the housing on the wireless data communication can be reduced. Therefore, according to this digital camera, the quality of wireless data communication can be improved. Further, the control unit of this digital camera increases the power supplied to the wireless communication unit when the detection unit detects the first attitude of the antenna. That is, the operation of placing the antenna in the first posture in order to improve the quality of wireless data communication also serves as the operation of increasing the power supplied to the wireless communication unit. Similarly, the operation of placing the antenna in the second posture also serves to reduce the power supplied to the wireless communication unit. Therefore, according to this digital camera, power consumption can be reduced.

According to a second aspect of the present invention, the digital camera further comprises setting means for setting whether or not to reduce the power supplied to the wireless communication section when the second attitude of the antenna is detected by the detection section, and the control is performed. When the second posture of the antenna is detected by the detection unit, the power supplied to the wireless communication unit is not reduced when the setting unit does not reduce the second posture. According to this digital camera, when the power supplied to the wireless communication unit is set not to be reduced when the second attitude of the antenna is detected, for example, the antenna may be set to the second position for some unintended reason during wireless data communication. Even if the posture is reached, wireless data communication can be continued without interruption, and it is possible to avoid the situation of retransmitting from the beginning.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below based on Examples. FIG. 1 is a rear view of a digital still camera 1 which is an embodiment of the present invention. The case 2 of the digital still camera 1 has a metal box shape, and the case 2 accommodates an image pickup means described later. The antenna 90 of this embodiment is rod-shaped as shown in the drawing, and has one end 90.
a is swingably supported by the housing 2 and is in a standing posture (first posture) as shown in FIG. 1A and a folded posture (second posture as shown in FIG. 1B). Posture). When the antenna 90 takes the first posture as shown in FIG. 1A, the tip 90b of the antenna 90 becomes far from the housing 2, and the antenna 90 takes the second posture as shown in FIG. 1B. At this time, the tip 90b of the antenna 90 comes close to the housing 2.

FIG. 2 is a block diagram showing the configuration of the digital still camera 1. As shown in the figure, the camera body includes a control unit 10, an imaging unit 20, a drive unit 30, a processing unit 40,
Wireless communication unit 50, operation unit 60, display unit 70, power supply unit 8
0, the antenna 90, and the detection unit 100 are provided.

The control unit 10 comprises a CPU 11, a ROM 12 and a RAM 13. The CPU 11 controls each unit by executing a computer program stored in the ROM 12, and also a process of transmitting image data via the wireless communication unit 50, a process of controlling the power control circuit 53 of the wireless communication unit 50, an antenna. When the second posture of 90 is detected, a process of setting whether to reduce the power supplied to the wireless communication unit 50 or the like is performed. The ROM 12 is a memory that stores a control program and data for the CPU 11 to execute various controls, a setting program for executing processing for setting whether to reduce power, and the like. Note that the control program uses B in the Bluetooth protocol.
A protocol stack located above the aseband layer is also included. The RAM 13 is a memory for temporarily storing various programs and data. or,
The RAM 13 also stores setting information indicating whether or not the power set on the setting screen 75 (see FIG. 3) is reduced.

The image pickup section 20 is provided with an optical system and an area image sensor 23 (hereinafter, simply referred to as area sensor 23). The optical system includes a zoom lens 21 and an optical diaphragm 2.
2 and an optical low pass filter (LPF), the zoom lens 21 forms a subject image on the light receiving portion of the area sensor 23 at a set magnification, and the optical diaphragm 22 adjusts the amount of light incident on the area sensor 23. To do. Area sensor 2
3 accumulates electric charges obtained by photoelectrically converting light received by each photoelectric conversion element for a certain period of time, and outputs an electric signal according to the amount of received light to the processing unit 40. CC as the area sensor 23
A D-type image sensor may be used, or a MOS-type image sensor may be used.

The drive unit 30 includes a lens drive unit 31, an aperture drive unit 32, and an area sensor drive unit 33, and controls the input / output of the area sensor 23. The lens driving unit 31 drives the zoom lens 21 to realize a zoom function or a focus adjustment function. The diaphragm driving unit 32 drives the optical diaphragm 22 to adjust the amount of light incident on the area sensor 23. The area sensor drive unit 33 is an electronic circuit that generates a drive pulse necessary for driving the area sensor 23 and inputs the drive pulse to the area sensor 23.

The processing section 40 comprises an analog front end section 41, a digital image processing section 45 and a data storage processing section 46. Analog front end (AFE)
The unit 41 includes a correlated double sampling (CDS) circuit 42,
Auto gain control (AGC) circuit 43 and A /
It has a D converter 44. The CDS circuit 42 performs a reduction process of noise included in the analog electric signal. AGC circuit 4
Reference numeral 3 adjusts the level of the analog electric signal by adjusting the gain. The A / D converter 44 quantizes the analog electric signal subjected to each of the above processes into a digital image signal of a predetermined gradation and outputs the image signal. The output image signal is output to the digital image processing unit 45.

The digital image processing unit 45 includes a DSP (Di
digital signal processor), and gamma correction of the image signal output from the AFE unit 41, interpolation of defective pixels by a pixel interpolation method, white balance correction, sharpening of the image signal, correction of the effects of camera shake, compression / expansion processing. Image data is created by performing image processing such as pixel number conversion processing.

Note that the various types of processing performed by the digital image processing section 45 may be replaced with processing by a computer program executed by the control section 10. The function of the “imaging unit” described in the claims corresponds to the function of the imaging unit 20, the driving unit 30, and the processing unit 40 creating image data representing a subject image under the control of the control unit 10.

The data storage processing unit 46 comprises a non-volatile memory. The non-volatile memory is a memory for storing the created image data. As the non-volatile memory, for example, a recording medium such as a flash memory, a magnetic disk, a magneto-optical disk can be used. The nonvolatile memory may be detachably connected to the main body of the digital still camera 1 or may be non-detachably connected.

The wireless communication section 50 is constructed in accordance with the Bluetooth standard, and has a baseband section 51, RF (Ra
A dio specification) unit 52 and a power control circuit 53. The baseband unit 51 is a DSP (Digital Signal Pro).
cessor), microcomputer, system clock, etc., and Bluetooth protocol Baseba
It implements the functions defined in the nd layer, and performs the process of establishing a physical RF link between devices. RF unit 52 is D / A
With a converter, modulator, demodulator, etc., Bluetooth
It implements the functions specified in the RF layer of the protocol,
Performs data modulation / demodulation processing. The power control circuit 53 includes a relay switch and a relay drive circuit that turns on / off the relay switch. The baseband unit 51 and the RF unit 52 excluding the system clock are connected to the power supply unit 80 via a relay switch, while the system clock is connected to the power supply unit 80 not via the relay switch.
This allows the system clock to turn on / off the relay switch.
Power is always supplied regardless of the off state. The control unit 10 can control the relay drive circuit. When the control unit 10 controls the relay drive circuit to turn on the relay switch, the power supplied to the wireless communication unit 50 increases, and conversely when turned off. Electric power is reduced. As a result, the control unit 10 increases and decreases the power supplied to the wireless communication unit 50. When the supplied power is reduced, the wireless communication unit 50 enters a standby mode in which only the system clock is driven, while when the supplied power is increased, the wireless communication unit 50 enters a communication mode in which wireless data communication is possible.

In this embodiment, the power for driving the system clock is supplied to the wireless communication unit 50 even when the power supplied to the wireless communication unit 50 is reduced. When it is reduced, the power to be supplied may be completely cut off.

The operation unit 60 detects a switch operation by the user and outputs a control signal to the control unit 10. Operation unit 60
Is a plurality of setting buttons 71, 72 for setting whether to increase or decrease the power supplied to the wireless communication unit 50 when the power switch for turning the power on and off and the antenna 90 takes the second posture. And 73, an image pickup button for instructing execution of image pickup, a zoom button for setting the magnification of the zoom lens, and the like.

The display section 70 includes an LCD 74, an LCD drive circuit and an encoder. The LCD 74 displays the image data by being controlled by the LCD drive circuit, and also when the antenna 90 takes the second posture, the wireless communication unit 5
A setting screen 75 (see FIG. 3) for the user to set whether to reduce the power supplied to 0 is displayed.

The power supply unit 80 includes a power supply such as a lithium ion battery and supplies power to each unit of the digital still camera 1. The antenna 90 transmits a radio wave corresponding to the carrier wave modulated by the RF unit 52 of the wireless communication unit 50, receives a radio wave transmitted from another device, and outputs the radio wave to the demodulator.

The detecting section 100 is a sensor for detecting the first posture and the second posture of the antenna 90.
0 detects the posture of the antenna 90 at predetermined intervals and outputs a detection signal indicating the detected posture to the control unit 10.

The configuration of the digital still camera 1 has been described above. Next, the setting screen 75 for the user to set whether to reduce the power supplied to the wireless communication unit 50 when the second attitude of the antenna 90 is detected will be described.

FIG. 3 is a diagram showing the setting screen 75. The setting screen 75 is output to the display unit 70 by the CPU 11 executing the setting program. “Not reduced” means that the power supplied to the wireless communication unit 50 is not reduced when the second attitude of the antenna 90 is detected, and “Reduced” is the wireless communication unit when the second attitude of the antenna 90 is detected. Fifty
It means to reduce the power supplied to. Setting button 71
After selecting any one of the buttons 72 and 72, when the setting button 73 is pressed, the setting is performed according to the selection. Here, the setting means that the setting information representing the selected information is stored in a predetermined address of the RAM 13.

The processing when the attitude of the antenna 90 is detected will be described below. FIG. 4 is a flowchart showing the flow of processing when the attitude of the antenna 90 is detected. This processing is started when the detection unit 100 detects the attitude of the antenna 90.

The detecting section 100 detects the attitude of the antenna 90 and outputs a detection signal representing the detected attitude to the control section 10 (S105). When the detection signal is output from the detection unit 100, the control unit 10 determines from the detection signal output from the detection unit 100 whether or not the posture of the antenna 90 has changed from the posture detected at the previous time (S110). When it is determined that the position has changed, it is determined whether the first position has changed to the second position or the second position has changed to the first position (S115). When changing from the second posture to the first posture, the control unit 10 controls the power control circuit 53 to increase the power supplied to the wireless communication unit 50. As a result, the wireless communication unit 50 enters a communication mode in which wireless data communication is possible (S120). After the wireless data communication is enabled, the wireless data communication is performed according to the Bluetooth protocol.

On the other hand, when it is determined in S115 that the first attitude has changed to the second attitude, the controller 10 causes the RAM 13 to operate.
It is determined whether to reduce the power supplied to the wireless communication unit 50 based on the setting information stored in (S125). When it is set to be reduced by the setting information, the control unit 10 determines to reduce the power to be supplied, and controls the power control circuit 53 to reduce the power to be supplied to the wireless communication unit 50. As a result, the wireless communication unit 50 enters a standby mode in which only the system clock is operated (S130). On the other hand, if the setting information indicates that the power to be supplied should not be reduced, the control unit 10 determines in S125 that the power to be supplied should not be reduced, and does not perform the process of reducing the power. As a result, the power supply to the wireless communication unit 50 is continued and the wireless data communication can be continued.

The processing when the attitude of the antenna 90 is detected has been described above. Next, a flow of processing of wireless data communication will be described by taking as an example a case where image data is transmitted to a printer to request printing.

FIG. 5 is a sequence chart showing the flow of wireless data communication processing. The user of the digital still camera 1 moves the digital still camera 1 within a radius of about 10 m of the printer to put the antenna 90 in the first posture. Here, the radius of about 10 m is the maximum communicable distance defined by Bluetooth. (S205).
The detection unit 100 of the digital still camera 1 uses the antenna 9
When the first posture of 0 is detected, the wireless communication unit 50 enters the communication mode, and the wireless connection between the digital still camera 1 and the printer is established according to the Bluetooth protocol (S210). When the wireless connection is established, the user selects image data to be printed by the printer on the display unit 70,
A predetermined operation is performed to instruct the control unit 10 to perform wireless transmission (S215). When the control unit 10 is instructed to be transmitted by the user, the control unit 10 executes the upper layer protocol stack stored in the ROM 12 and instructs the wireless communication unit 50 to transmit the image data (S220). In response to the command, the wireless communication unit 50 wirelessly transmits the designated image data and the print command to the printer (S225). The printer prints the received image data according to the print command (S230). If the power supplied to the wireless communication unit 50 is set to be reduced when the antenna 90 is in the second posture, when the user puts the antenna 90 in the second posture after wireless transmission, the power to the wireless communication unit 50 is reduced. Is reduced (S235).

The flow of wireless data communication processing has been described above. The effects of this embodiment will be described below.
According to the digital still camera 1 of the present embodiment, the tip 9 of the antenna 90 is set by placing the antenna 90 in the first posture.
0b becomes far from the housing 2, and the antenna 90 and the housing 2 can be separated from each other. As a result, the distance between the antenna 90 and the human body can be increased, and the influence of the human body and the housing on the wireless data communication can be reduced. Therefore, according to the digital still camera 1 of the present embodiment, the quality of wireless data communication can be improved. Further, the control unit 10 of the digital still camera 1 of the present embodiment increases the power supplied to the wireless communication unit 50 when the detection unit 100 detects the first attitude of the antenna 90.
That is, the operation of placing the antenna 90 in the first posture in order to reduce the influence of the human body and the casing also serves as the operation of increasing the power supplied to the wireless communication unit 50. Similarly, the operation of placing the antenna 90 in the second posture also serves to reduce the power supplied to the wireless communication unit 50. Therefore, according to the digital still camera 1 of the present embodiment, when the wireless data communication is not performed, the power supplied to the wireless communication unit 50 can be reduced by placing the antenna in the second posture, and the power consumption can be reduced. it can.

Further, according to the digital still camera 1 of the present embodiment, the user of the digital still camera 1 himself determines whether or not to reduce the power supplied to the wireless communication section 50 when the second attitude of the antenna 90 is detected. Can be set. If the power supplied to the wireless communication unit 50 is not reduced when the second posture of the antenna 90 is detected, the antenna 90 is set to the second posture for some unintended reason during the wireless data communication. Even if it happens, wireless data communication can be continued without interruption, and it is possible to avoid the situation of retransmitting from the beginning.

In the present embodiment, the rod-shaped antenna 90 whose one end is swingably supported by the housing 2 has been described as an example, but the antenna may be, for example, a telescopic antenna. The first posture is a pulled-out posture, and the second posture is a stored posture.

In this embodiment, Bluetooth has been described as an example of the wireless data communication standard, but the wireless data communication standard may be another standard. Further, in this embodiment, the power control circuit 53 is provided inside the wireless communication unit 50.
Although a case has been described as an example, a power control circuit may be provided outside the wireless communication unit 50, and the power supplied to the wireless communication unit 50 may be increased or decreased by controlling the power control circuit.

Although the digital still camera 1 has been described as an example in this embodiment, the present invention may be applied to a digital video camera.

[Brief description of drawings]

FIG. 1 is a rear view of a digital camera that is an embodiment of the present invention.

FIG. 2 is a block diagram showing a digital camera which is an embodiment of the present invention.

FIG. 3 is a diagram showing a screen for setting whether to reduce the power supplied to the wireless communication unit of the digital camera according to the embodiment of the present invention.

FIG. 4 is a flowchart showing a flow of processing when the detection unit of the digital camera according to the exemplary embodiment of the present invention detects the attitude of the antenna.

FIG. 5 is a sequence chart showing a flow of processing for wirelessly transmitting image data by the digital camera according to the embodiment of the present invention.

[Explanation of symbols]

1 Digital still camera (digital camera) 2 housing 10 Control unit 20 Imaging unit (imaging means) 30 Drive unit (imaging means) 40 processing unit (imaging means) 50 Wireless communication section 60 Control 70 Display 71, 72, 73 setting buttons 75 Setting screen 80 power supply 90 antenna 100 detector

Claims (2)

[Claims] 1. An image pickup means for creating image data representing a subject, a housing for housing the image pickup means, a first posture supported by the housing and having a distal end far from the housing and a distal end for the housing. An antenna that can take a second posture close to the body, a wireless communication unit that performs wireless data communication with another device using the antenna, a detection unit that detects the posture of the antenna, the first of the antenna A control unit that increases power supplied to the wireless communication unit when the orientation is detected by the detection unit and reduces power supplied to the wireless communication unit when the second orientation of the antenna is detected by the detection unit. A digital camera comprising: 2. The apparatus further comprises setting means for setting whether or not to reduce the power supplied to the wireless communication section when the second attitude of the antenna is detected by the detection section. The digital device according to claim 1, wherein when the second posture is detected by the detection unit, the power supplied to the wireless communication unit is not reduced when the setting unit is set not to reduce the second posture. camera.