JP4072022B2 - camera - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a camera that photographs a subject by obtaining image data by forming an image of the subject on a solid-state imaging device.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, digital cameras and video cameras have been used to monitor and photograph a subject using a primary battery or a secondary battery as a drive source.
[0003]
For example, in a digital camera, a subject is displayed on a liquid crystal screen as a moving image, and the subject is photographed by, for example, firing a strobe while viewing the liquid crystal display screen. Or a series of captured still images are reproduced one after another, and an image to be stored in memory and an image to be erased are selected. The display mode on the liquid crystal screen is generally selected by a mode selection button, and the amount of power consumed varies depending on the selected mode. Therefore, for example, even if the subject is displayed on the LCD screen as a moving image and the battery is depleted while aiming for a shutter chance, the expected number of images cannot be produced, or even if the display by moving image is conservative, the time can be continuously used. Has restrictions, and there is a problem that the battery needs to be replaced or charged each time.
[0004]
Therefore, for example, a second power source that is a solid electrolyte secondary battery that supplies a stable output over a long period of time with a small current, and a first power source such as a lead storage battery or a lithium secondary battery that supports a large current, As the second power source, there is a hybrid power source that can be charged in a short time by heating with a heater (see Patent Document 1).
[0005]
In recent years, fuel cells have attracted attention as clean energy with high energy conversion efficiency and no air pollution. Depending on the application such as for power generation system, cogeneration system, electric vehicle, general household, etc., operating temperature and fuel used Although various types of fuel cells with different types have been developed, polymer electrolyte fuel cells that can obtain much higher energy density than primary and secondary batteries at operating temperatures close to normal temperatures are It is in the limelight as a power source for electronic equipment that can continuously supply power.
[0006]
For example, a fuel cell that uses hydrogen gas as a fuel and uses a fullerene as an electrolyte membrane to eliminate the need for humidification means and water retention means can be used for a long time by arranging it between the wall portions of the housing. There are small and lightweight portable devices (see Patent Document 2).
[0007]
[Patent Document 1]
JP-A-7-73901 (page 2-3, FIG. 1)
[0008]
[Patent Document 2]
JP 2002-134154 A (page 2-4, FIG. 2)
[0009]
[Problems to be solved by the invention]
However, according to the technology disclosed in Patent Document 1, it is possible to avoid supplying electric power from a battery with different outputs to an electric circuit of another system in the device, and both electric circuits being down at the same time. It is impossible to extend the operating time. In addition, the configuration using only the fuel cell disclosed in Patent Document 2 has a problem that the supply voltage decreases when the load fluctuation of the device is large and the load becomes larger than the output density of the fuel cell. .
[0010]
In view of the above circumstances, an object of the present invention is to provide a camera capable of continuous shooting for a long time by switching a plurality of batteries according to load characteristics.
[0011]
[Means for Solving the Problems]
The camera of the present invention that achieves the above object is a camera that images a subject by imaging the subject on a solid-state imaging device to obtain image data.
An image display unit for displaying an image based on the image data;
A display mode selection unit for selecting a mode for displaying an image on the image display unit;
A plurality of batteries and the battery and each have a switching unit for connecting and disconnecting between the output terminal, that to supply power from the output terminal power supply unit having a different power density,
A control unit that controls the disconnection by the switching unit according to the mode selected by the display mode selection unit ,
This camera is a camera that captures and reproduces both moving images and still images, and the plurality of batteries are a fuel cell and a secondary battery,
When the moving image display mode for displaying a moving image is selected by the display mode selection unit, the control unit connects both the fuel cell and the secondary battery and the output terminal, and the display mode selection unit When the still image display mode for displaying a still image is selected, the switching unit is controlled so that the fuel cell and the output terminal are connected .
[0014]
As described above, when the still image display mode is selected and the power consumption is relatively low, power is supplied from the fuel cell having a relatively low output density and a large energy density, the video display mode is selected, and the power consumption is reduced. When the size is large, in addition to the fuel cell, a secondary battery that has a relatively high output density but a relatively low energy density can be used for continuous shooting over a long period of time.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described.
[0016]
FIG. 1 is a schematic block diagram showing an embodiment of a digital camera to which the camera of the present invention is applied.
[0017]
A digital camera 1 shown in FIG. 1 includes a CPU 20 that controls the entire camera, each function unit, a main body 10 that includes a BUS wiring 30 that communicates between each function unit and the CPU 20, and a CPU 20 when set by an operator. Is configured by a setting system 15 such as a mode selection dial 16, a playback button 17 and a shutter 18 that are controlled by each function unit, and a power supply unit 30 that supplies power to the main body 10. The exposure function is omitted.
[0018]
In the main body 10, an imaging lens 11 that forms an image of a subject on a solid-state imaging device (herein, a CCD is used, hereinafter abbreviated as a CCD), and a plurality of photoelectric conversion elements arranged vertically and horizontally constitute each pixel. The CCD 25 that converts the light quantity distribution of the light image of the subject into an electrical signal and accumulates it as an electric charge, the CDSAMP 26 that reads out the electric charge as an RGB signal at the timing set by the timing generator, and suppresses the noise, and the RGB signal A / D converter 27 for converting image data into digital signals to obtain image data, memory (1) 23 for primary storage of image data, and D / A conversion of the image data primarily stored in memory (1) The LCD display unit 29 displays an image of the subject, the signal processing unit 28 performs color conversion processing, γ correction, etc. on the image data, and the signal processing unit 28 A memory (2) 24 for storing the recorded image data, and a recording medium (semiconductor memory) 22 for recording after the image data stored in the memory (2) 24 is read and subjected to JPEG compression processing. .
[0019]
The digital camera 1 also has an output terminal 31, and includes a power supply unit 30 that supplies predetermined power from the output terminal 31 to the main body 10, and the power supply unit 30 includes batteries (A) 32 and 2 made of fuel cells. The battery (B) 33 is a secondary battery, and the battery (A) 32, the battery (B) 33, and the switching unit 35 that disconnects the connection between the output terminal 31. The CPU 20 controls the switching unit 35 according to the mode selected by the mode selection dial 16, disconnects the output terminal 31 from the battery (A) 32 and the battery (B) 33, and outputs the power supply unit 30. A predetermined power is output from the terminal 31.
[0020]
The power supply unit 30 of the present embodiment includes the battery (A) 32 and the battery (B) 33 having different output densities, but the battery is not limited to the two types of the battery (A) 32 and the battery (B) 33. Three or more types may be provided.
[0021]
FIG. 2 is a diagram illustrating an example of connection / disconnection depending on the mode selected by the mode selection dial.
[0022]
As shown in FIG. 2, the battery A is a fuel cell having a small output density and a large energy density, and the battery B has a relatively large output density and the energy density is a fraction of that of the fuel cell. Next battery.
[0023]
When the power of the digital camera 1 is turned off (OFF), the battery (A) is disconnected, the battery (B) is energized, the timer is driven, and the fuel cell is started smoothly. Energize the heater. When the power source of the digital camera 1 is connected (ON), the battery (A) is always energized, and the battery (B) is used to shoot or play back videos with high power consumption. When the display mode is selected, the battery (A) is overloaded to prevent the voltage from being lowered as an energized state. When the battery (A) selects a mode other than the moving image display mode such as still image shooting or playback that can sufficiently consume power, the battery (B) is disconnected.
[0024]
Here, when the battery (A) is disconnected while the battery (A) is energized, the battery (B) can be charged by the battery (A).
[0025]
In this embodiment, the control of the battery by the CPU is divided into a moving image display mode and a still image display mode. However, it is not necessarily limited to this division, and it is further subdivided by an autofocus function or a zoom function. Also good.
[0026]
FIG. 3 is a flowchart illustrating control of the switching unit by the CPU of the digital camera body.
[0027]
As shown in FIG. 3, when a battery is attached to the power supply unit of the digital camera of this embodiment (S-1), the connection between the battery (A) and the output terminal is disconnected, and the battery (B) and the output terminal are disconnected. (S-2). When the power switch of the digital camera is turned on (S-3), the battery (A) and the output terminal are connected, and the connection between the battery (B) and the output terminal is disconnected (S-4). . If it is confirmed that the power switch of the digital camera is not cut off in this state (S-5), it is determined whether the mode selection dial is in the moving image display mode or the still image display mode ( S-6) When the moving image display mode is selected, the battery (A) and the output terminal are connected, and the battery (B) and the output terminal are also connected (S-7). When the still image display mode is selected with the mode selection dial, the battery (A) and the output terminal are connected, and the connection between the battery (B) and the output terminal is disconnected. (S-4). When it is confirmed that the power switch of the digital camera is disconnected (S-5), the battery (A) is connected to the output terminal, and the battery (B) is connected to the output terminal. Shooting is stopped while maintaining the disconnected state (S-8).
[0028]
Here, the power supply unit includes two batteries, that is, a battery A and a battery B having different output densities.
[0029]
Thus, when the image display mode is divided in advance and a display mode with relatively low power consumption is selected, power is supplied from a fuel cell with a relatively small output density but a large energy density, and the power consumption is large. When the display mode is selected, in addition to the fuel cell, a secondary battery having a low energy density but a high output density is configured to be backed up, so that continuous shooting can be performed for a long time. . If the secondary battery is charged with a fuel cell when the power consumption is relatively small, the continuous shooting time can be further increased.
[0030]
Although the present embodiment has been described based on a digital camera, the camera need not be limited to a digital camera, and may be a video camera.
[0031]
【The invention's effect】
As described above, according to the camera of the present invention, a plurality of batteries having different output densities are provided, and the outputs of these batteries are switched according to load characteristics, so that continuous shooting can be performed for a long time. Can do.
[Brief description of the drawings]
FIG. 1 is a schematic block diagram showing an embodiment of a digital camera to which a camera of the present invention is applied.
FIG. 2 is a diagram illustrating an example of connection / disconnection according to a mode selected by a mode selection dial.
FIG. 3 is a flowchart illustrating control of a switching unit by a CPU of a digital camera body.
[Explanation of symbols]
1 Digital Camera 10 Main Body 11 Imaging Lens 15 Setting System 16 Mode Selection Dial 17 Playback Button 18 Shutter 20 CPU
22 Recording media 23 Memory (1)
24 memory (2)
25 CCD
26 CDS AMP
27 A / D Converter 28 Signal Processor 29 LCD Display 30 Output Terminal 31 Battery (A)
32 Battery (B)
35 switching part

Claims (1)

In a camera that images a subject by imaging the subject on a solid-state imaging device to obtain image data,
An image display unit for displaying an image based on the image data;
A display mode selection unit for selecting a mode for displaying an image on the image display unit;
A plurality of batteries and the battery and each have a switching unit for connecting and disconnecting between the output terminal, that to supply power from the output terminal power supply unit having a different power density,
A control unit for controlling the disconnection by the switching unit according to the mode selected by the display mode selection unit ,
This camera is a camera that captures and reproduces both moving images and still images, and the plurality of batteries are a fuel cell and a secondary battery,
When the moving image display mode for displaying a moving image is selected by the display mode selection unit, the control unit connects both the fuel cell and the secondary battery and the output terminal, and the display mode selection unit When the still image display mode for displaying a still image is selected , the camera controls the switching unit so that the fuel cell and the output terminal are connected .

Images