JP2005006135A - Image photographing device and method for saving power of the device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image photographing device capable of suppressing battery consumption by instantly reducing or stopping power feeding when a power supply switch is turned on carelessly without the intention of a photographer. <P>SOLUTION: In this image photographing device provided with an imager 30 for imaging an object, a control means 20 connected electrically to the imager 30 to process a signal from the imager 30, a power supply means 50 for feeding power to the imager 30 and the control means 20, and a power supply switch 60 for applying on/off control to energization from the power supply means 50 to the imager 30 and the control means 20, the control means 20 reduces or stops power feeding from the power supply means 50 when the control means 20 determines that an output signal from the imager 30 is not higher than a prescribed value with the power supply switch 60 turned on. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to power saving of an image photographing apparatus such as a digital camera.
[0002]
[Prior art]
An apparatus having an image photographing function such as a digital camera, a digital video camera, a video camera, and a camera-equipped mobile phone has an image pickup device such as a CCD for photographing a subject and an image display means such as an LCD monitor for viewing the photographed image. Yeah. As the power source of these image capturing apparatuses, a battery, generally a rechargeable secondary battery is used from the viewpoint of outdoor use and portability.
[0003]
In the image capturing apparatus as described above, since the capacity of the battery used is limited due to portability and miniaturization, when the stop of the photographing operation does not continue for a certain time or longer, the image display means or Some have a function of stopping power supply to circuits other than the operation switch detection circuit, that is, a so-called “sleep mode”.
Some mobile phones turn off the backlight of the image display means when no operation is performed for a certain time (see, for example, Patent Document 1).
[0004]
[Patent Document 1]
JP 04-117735 A (full text)
[0005]
[Problems to be solved by the invention]
When the image photographing apparatus is in a bag or pocket, something hits the power switch, and the power switch may be turned on regardless of the intention of the photographer. In this case, even a device having a sleep mode is in a power-on state for a certain period of time and consumes a battery. In many sleep modes, the setting time can be changed according to the photographer's settings. However, in the case of a digital camera, a digital video camera or a video camera, in general, the sleep mode is generally set to about 5 to 10 minutes. . This is because if the setting time is short, the sleep mode is entered before the composition is determined, which makes it inconvenient to shoot.
However, when the power switch is turned on due to an erroneous operation, the image display means remains energized until the set time of the sleep mode elapses. In some cases, the capacity of the battery is insufficient, and photography cannot be performed.
[0006]
SUMMARY OF THE INVENTION An object of the present invention is to provide an image photographing apparatus capable of immediately reducing or stopping the supply of power and suppressing battery consumption when a power switch is turned on carelessly, not by a photographer's intention. That is.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, an image capturing apparatus of the present invention provides:
An image sensor for imaging a subject;
Control means electrically connected to the image sensor and processing signals from the image sensor;
Power supply means for supplying power to the image sensor and the control means;
A power switch for controlling on / off of energization of the imaging device and the control means from the power supply means;
In an image photographing device comprising
When the control means determines that the output signal from the image sensor is not more than a predetermined value with the power switch turned on, the supply of power from the power supply means is reduced or stopped.
[0008]
[Action and effect]
When the control means determines that the output signal from the image sensor is less than or equal to a predetermined value when the power switch is on, the power supply from the power supply means is reduced or stopped, thereby reducing unnecessary battery consumption. Is prevented.
The timing at which the control means determines the output signal from the imaging device is, for example, immediately after the power switch is turned on, a predetermined time after the power switch is turned on, or a predetermined time after the last operation. be able to.
[0009]
According to the image capturing device of the present invention, when the image capturing device is turned on against the photographer's intention, for example, in a bag or pocket, or without removing the lens cover. Since the supply of power can be reduced or stopped without waiting for the elapse of time set in the sleep mode, battery consumption can be extremely reduced.
[0010]
The present invention is advantageous in that it can be executed by directly using functions provided in advance by an image capturing device such as a digital camera, no additional hardware is required, and wasteful power consumption of the power supply means can be suppressed.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a block diagram showing a schematic configuration of an image capturing device (10) of the present invention. Examples of the image capturing device include a digital camera, a digital video camera, a video camera, and a camera-equipped mobile phone.
[0012]
As shown in FIG. 1, the image photographing device (10) is configured around a control means (20), and an image pickup device (30) such as a CCD for photographing a subject is A / D included in the control means (20). The converter (32) and the signal processing circuit (34) are connected. Further, the control means (20) includes an image display means (40) for visually recognizing the photographed image, a power supply means (50) such as a secondary battery, and a power switch (60) operated by a photographer's on / off operation. Are connected, and power is supplied from the power supply means (50) to the control means, the image sensor (30), the image display means (40), and the like by turning on the power switch.
[0013]
The power saving method of the present invention will be described with reference to the flowchart FIG.
When the photographer turns on the power switch (60) or when the power switch (60) is turned on when the photographer does not intend (step 1), power is supplied from the power supply means (50). Then, the image photographing device (10) is activated.
The image pickup device (30) starts photographing when the power of the image photographing device (10) is turned on. The captured image is digitally converted through an A / D converter (32) and sent to a signal processing circuit (34). The control means (20) determines whether the output signal input from the signal processing circuit (34) is equal to or less than a predetermined value. An example of the determination target is the ratio of the number of output pixels (the number of output pixels / the number of effective pixels). In addition, the average value or integrated value of the image output can be used as an output signal for determining brightness and a predetermined value. For example, when a 10-bit output A / D converter is used and the predetermined value is 50 (50/1024), the average value can be determined to be 50 or less, and the integrated value can be determined to be 50 × number of pixels or less.
[0014]
If the output signal input from the signal processing circuit (34) is less than or equal to a predetermined value, it is determined that the image captured by the image sensor (30) is dark or nearly dark (step 2), and the control means (20 ) Determines that the power switch (60) is turned on regardless of the photographer's intention (step 3). In this case, the control means (20) reduces or stops the supply of power from the power supply means (50) (step 4). By reducing or eliminating the power consumption of the power supply means (50), power saving can be achieved and the battery life can be extended.
[0015]
When the output signal is higher than the predetermined value (step 2), it is determined that the power switch (60) is turned on by the photographer's intention (step 5), and normal operations such as photographing are started (step 5). 6).
[0016]
Note that the timing of the determination in step 2 is, for example, immediately after the power switch is turned on and the image sensor starts to start normally, or for a predetermined time (for example, 5 seconds to 10 seconds) after the power switch is turned on. It can be after.
Further, the determination may be performed with only one frame signal, or may be performed with respect to an average or maximum value of signals for a predetermined time (for example, 1 to 5 seconds).
[0017]
Even if the power switch (60) is turned on unintentionally by the photographer, the power supply from the power supply means (50) is reduced or stopped if the surroundings of the image photographing device (10) are dark. Therefore, it is possible to prevent the power supply means (50) from being consumed.
[0018]
When performing special shooting such as astronomical shooting or night shooting, the power switch (60) is forcibly set by the above function even though the power switch (60) is turned on in the dark for the photographer's intention. 60) is turned off, and such special shooting cannot be performed. In such a case, another switch is provided, or the method can be shifted to step 5 without performing the determination in step 2 by a method such as double pressing of the switch and the power switch (60). It is desirable.
[0019]
Also, as shown in the flowchart in FIG. 2, after the user has taken or operated, when the power switch (60) is turned on, the determination in step 1 is performed again, or the taken or operated. Thereafter, if the determination in step 1 is performed at predetermined time intervals, even if the image capturing device (10) is stored in a state where the power switch (60) is forgotten to be turned off, the power supply means (50) Since the supply of electric power can be reduced or stopped, the power supply means (50) can be prevented from being consumed.
[0020]
In the above embodiment, the control means (20) is configured to turn off the power switch (60) based on the determination in step 1. However, only the image display means (40) that consumes a large amount of power is cut off. It may be. Further, in order to notify the photographer that the power supply has been reduced or stopped, when the power supply is reduced or stopped, the LED may blink or a beep sound may be emitted.
[0021]
The above description of the embodiments is for explaining the present invention, and should not be construed as limiting the invention described in the claims or reducing the scope thereof. Moreover, each part structure of this invention is not restricted to the said Example, A various deformation | transformation is possible within the technical scope as described in a claim.
[Brief description of the drawings]
FIG. 1 is a block diagram of a main part of an image photographing apparatus of the present invention.
FIG. 2 is a flowchart showing a control operation of the image photographing apparatus of the present invention.
[Explanation of symbols]
(10) Image photographing device (20) Control means (30) Image sensor (40) Image display means (50) Power supply means (60) Power switch

Claims (7)

An image sensor (30) for imaging a subject;
Control means (20) electrically connected to the image sensor (30) and processing a signal input to the image sensor (30);
Power supply means (50) for supplying power to the image sensor (30) and the control means (20);
A power switch (60) for controlling on / off of energization from the power source means (50) to the image sensor (30) and the control means (20);
In an image photographing device comprising
When the control means (20) determines that the output signal from the image pickup device (30) is equal to or less than a predetermined value with the power switch (60) turned on, the control means (20) and the image pickup from the power supply means (50). An image capturing apparatus, wherein power supply to the element (30) is reduced or stopped. An image sensor (30) for imaging a subject;
Control means (20) electrically connected to the image sensor (30) for processing signals from the image sensor (30);
An image display means (40) for receiving a power supply from the power supply means (50) and displaying a signal input from the image pickup element (30) to the control means (20) as an image is the image pickup element (30), and the control means (20 And power supply means (50) for supplying power to the image display means (40),
A power switch (60) for controlling on / off of energization from the power supply means (50) to the image sensor (30), the control means (20), and the image display means (40);
In an image photographing device comprising
When the control means (20) determines that the output signal from the image sensor (30) is equal to or less than a predetermined value in a state where power is supplied to the image sensor (30), the power display means (50) displays the image display means. (40) An image capturing device characterized in that the supply of power to or is stopped. The image photographing device according to claim 1 or 2, wherein the control means (20) makes a determination when the power switch (60) is turned on and the image pickup device (30) starts to start normally. The image photographing device according to claim 1 or 2, wherein the control means (20) makes the determination after a predetermined time after the power switch (60) is turned on. 5. The image photographing device according to claim 1, wherein the control means (20) performs the determination continuously for a predetermined time. An image sensor (30) that images a subject, a control means (20) that is electrically connected to the image sensor (30) and processes a signal from the image sensor (30), an image sensor (30), and a control means A power supply means (50) for supplying power to (20), and a power switch (60) for controlling on / off of energization from the power supply means (50) to the image sensor (30) and the control means (20). A power saving method for the provided image photographing device,
The control means (20) detects an output signal from the image sensor (30),
Determine whether the detected output signal is below a predetermined value,
A power saving method for an image capturing apparatus that reduces or stops the supply of power from the power supply means (50) if the output signal is equal to or less than a predetermined value. An image pickup device (30) for picking up an image of a subject, a control means (20) electrically connected to the image pickup device (30) and processing a signal from the image pickup device (30), and a power supply means (50) The image display means (40) that receives the supply and displays the signal input from the image sensor (30) to the control means (20) as an image, the image sensor (30), the control means (20), and the image display means (40). ) And a power switch for controlling on / off of energization of the imaging device (30), the control means (20) and the image display means (40) from the power supply means (50). (60), and a power saving method for an image capturing apparatus comprising:
The control means (20) detects an output signal from the image sensor (30),
Determine whether the detected output signal is below a predetermined value,
A power saving method for an image capturing apparatus that controls to reduce or stop the supply of power from the power supply means (50) to the image display means (40) if the output signal is below a predetermined value.

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